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15 Jan 2021 at 01:31
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Bibliography on: Metagenomics


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RJR: Recommended Bibliography 15 Jan 2021 at 01:31 Created: 


While genomics is the study of DNA extracted from individuals — individual cells, tissues, or organisms — metagenomics is a more recent refinement that analyzes samples of pooled DNA taken from the environment, not from an individual. Like genomics, metagenomic methods have great potential in many areas of biology, but none so much as in providing access to the hitherto invisible world of unculturable microbes, often estimated to comprise 90% or more of bacterial species and, in some ecosystems, the bulk of the biomass. A recent describes how this new science of metagenomics is beginning to reveal the secrets of our microbial world: The opportunity that stands before microbiologists today is akin to a reinvention of the microscope in the expanse of research questions it opens to investigation. Metagenomics provides a new way of examining the microbial world that not only will transform modern microbiology but has the potential to revolutionize understanding of the entire living world. In metagenomics, the power of genomic analysis is applied to entire communities of microbes, bypassing the need to isolate and culture individual bacterial community members.

Created with PubMed® Query: metagenomic OR metagenomics OR metagenome NOT pmcbook NOT ispreviousversion

Citations The Papers (from PubMed®)


RevDate: 2021-01-14

Yang Y, Herbold CW, Jung MY, et al (2020)

Survival strategies of ammonia-oxidizing archaea (AOA) in a full-scale WWTP treating mixed landfill leachate containing copper ions and operating at low-intensity of aeration.

Water research, 191:116798 pii:S0043-1354(20)31331-2 [Epub ahead of print].

Recent studies indicate that ammonia-oxidizing archaea (AOA) may play an important role in nitrogen removal by wastewater treatment plants (WWTPs). However, our knowledge of the mechanisms employed by AOA for growth and survival in full-scale WWTPs is still limited. Here, metagenomic and metatranscriptomic analyses combined with a laboratory cultivation experiment revealed that three active AOAs (WS9, WS192, and WS208) belonging to family Nitrososphaeraceae were active in the deep oxidation ditch (DOD) of a full-scale WWTP treating landfill leachate, which is configured with three continuous aerobic-anoxic (OA) modules with low-intensity aeration (≤ 1.5 mg/L). AOA coexisted with AOB and complete ammonia oxidizers (Comammox), while the ammonia-oxidizing microbial (AOM) community was unexpectedly dominated by the novel AOA strain WS9. The low aeration, long retention time, and relatively high inputs of ammonium and copper might be responsible for the survival of AOA over AOB and Comammox, while the dominance of WS9, specifically may be enhanced by substrate preference and uniquely encoded retention strategies. The urease-negative WS9 is specifically adapted for ammonia acquisition as evidenced by the high expression of an ammonium transporter, whereas two metabolically versatile urease-positive AOA strains (WS192 and WS208) can likely supplement ammonia needs with urea. This study provides important information for the survival and application of the eutrophic Nitrososphaeraceae AOA and advances our understanding of archaea-dominated ammonia oxidation in a full-scale wastewater treatment system.

RevDate: 2021-01-14

Zeng Z, Wang C, Liu C, et al (2021)

Follow-up of a Rickettsia felis encephalitis: Some new insights in clinical and imaging features.

Rickettsia felis infection is a cause of unspecified encephalitis. However, the incidence of it was underestimated due to the intracellular feature of the pathogen and insufficient understanding of its clinical picture. Here we report a case of Rickettsia felis infection in a 26-year-old female who manifested with only certain neurological symptoms. With the lack of specific systemic inflammatory symptoms, the diagnosis was initially misdiagnosed as brain glioma. However, brain tissue biopsy showed prominent peri-vascular inflammatory infiltration which indicated inflammatory diseases. The spinal fluid Metagenomic Next-Generation Sequencing (mNGS) was taken after ruling out other common infectious and autoimmune diseases. The results suggested Rickettsia felis infection which was also supported by Weil Felix reaction in the serum. After the diagnosis was corrected as Rickettsia felis encephalitis, the patient was successfully treated with doxycycline and had a good prognosis in one-year follow up.

RevDate: 2021-01-14

Nicholls SM, Aubrey W, De Grave K, et al (2020)

On the complexity of haplotyping a microbial community.

Bioinformatics (Oxford, England) pii:5988481 [Epub ahead of print].

MOTIVATION: Population-level genetic variation enables competitiveness and niche specialization in microbial communities. Despite the difficulty in culturing many microbes from an environment, we can still study these communities by isolating and sequencing DNA directly from an environment (metagenomics). Recovering the genomic sequences of all isoforms of a given gene across all organisms in a metagenomic sample would aid evolutionary and ecological insights into microbial ecosystems with potential benefits for medicine and biotechnology. A significant obstacle to this goal arises from the lack of a computationally tractable solution that can recover these sequences from sequenced read fragments. This poses a problem analogous to reconstructing the two sequences that make up the genome of a diploid organism (i.e. haplotypes), but for an unknown number of individuals and haplotypes.

RESULTS: The problem of single individual haplotyping (SIH) was first formalised by Lancia et al. in 2001. Now, nearly two decades later, we discuss the complexity of "haplotyping" metagenomic samples, with a new formalisation of Lancia et al's data structure that allows us to effectively extend the single individual haplotype problem to microbial communities. This work describes and formalizes the problem of recovering genes (and other genomic subsequences) from all individuals within a complex community sample, which we term the metagenomic individual haplotyping (MIH) problem. We also provide software implementations for a pairwise single nucleotide variant (SNV) co-occurrence matrix and greedy graph traversal algorithm.

Our reference implementation of the described pairwise SNV matrix (Hansel) and greedy haplotype path traversal algorithm (Gretel) are open source, MIT licensed and freely available online at github.com/samstudio8/hansel and github.com/samstudio8/gretel, respectively.

RevDate: 2021-01-14

Maguire M, Kase JA, Roberson D, et al (2021)

Precision long-read metagenomics sequencing for food safety by detection and assembly of Shiga toxin-producing Escherichia coli in irrigation water.

PloS one, 16(1):e0245172 pii:PONE-D-20-31905.

Shiga toxin-producing Escherichia coli (STEC) contamination of agricultural water might be an important factor to recent foodborne illness and outbreaks involving leafy greens. Closed bacterial genomes from whole genome sequencing play an important role in source tracking. We aimed to determine the limits of detection and classification of STECs by qPCR and nanopore sequencing using 24 hour enriched irrigation water artificially contaminated with E. coli O157:H7 (EDL933). We determined the limit of STEC detection by qPCR to be 30 CFU/reaction, which is equivalent to 105 CFU/ml in the enrichment. By using Oxford Nanopore's EPI2ME WIMP workflow and de novo assembly with Flye followed by taxon classification with a k-mer analysis software (Kraken2), E. coli O157:H7 could be detected at 103 CFU/ml (68 reads) and a complete fragmented E. coli O157:H7 metagenome-assembled genome (MAG) was obtained at 105-108 CFU/ml. Using a custom script to extract the E. coli reads, a completely closed MAG was obtained at 107-108 CFU/ml and a complete, fragmented MAG was obtained at 105-106 CFU/ml. In silico virulence detection for E. coli MAGs for 105-108 CFU/ml showed that the virulotype was indistinguishable from the spiked E. coli O157:H7 strain. We further identified the bacterial species in the un-spiked enrichment, including antimicrobial resistance genes, which could have important implications to food safety. We propose this workflow provides proof of concept for faster detection and complete genomic characterization of STECs from a complex microbial sample compared to current reporting protocols and could be applied to determine the limit of detection and assembly of other foodborne bacterial pathogens.

RevDate: 2021-01-14

Zhuang S, Hong H, Zhang L, et al (2021)

Spoilage-related microbiota in fish and crustaceans during storage: Research progress and future trends.

Comprehensive reviews in food science and food safety, 20(1):252-288.

Fish and crustaceans are highly perishable due to microbial growth and metabolism. Recent studies found that the spoilage process of fish and crustaceans is highly related to their microbiota composition. Microbiota of fish and crustaceans changes dramatically during storage and can be influenced by many factors (e.g., aquaculture environment, handling process, storage temperature, and various quality control techniques). Among them, many quality control techniques have exhibited efficient effects on inhibiting spoilage bacteria, regulating microbiota composition, and retarding quality deterioration. In this article, we elucidate the relationship between microbiota composition and fish/crustacean spoilage, demonstrate influencing factors of fish/crustaceans microbiota, and review various quality control techniques (especially plant-derived preservatives) including their preservative effects on microbiota and quality of fish and crustaceans. Besides, present and future trends of various detective methods used in microbiota analysis are also compared in this review, so as to provide guides for future microbiota studies. To conclude, novel preservation techniques (especially plant-derived preservatives) and hurdle technologies are expected to achieve comprehensive inhibitory effects on spoilage bacteria. Efficient delivery systems are promising in improving the compatibility of plant-derived preservatives with fish/crustaceans and enhancing their preservative effects. Besides, spoilage mechanisms of fishery products that involve complex metabolisms and microbial interactions need to be further elucidated, by using omics technologies like metagenomics, metatranscriptomics, and metabolomics.

RevDate: 2021-01-14

Taketani NF, Taketani RG, Leite SGF, et al (2021)

Application of extracellular polymers on soil communities exposed to oil and nickel contamination.

Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology] [Epub ahead of print].

The petrochemical industry is responsible for many accidental releases of pollutants in soil such as hydrocarbons and toxic metals. This co-contamination is responsible for a delay in the degradation of the organic pollution. Many successful technologies to remove these metals apply extracellular polymeric substances (EPS). In this study, we tested the application of an EPS from a Paenibacillus sp. to aid the bioremediation of soils contaminated with crude oil and nickel. We conducted a microcosm experiment to soils containing combinations of oil, nickel, and EPS. The final concentration of oil was evaluated with an infrared spectrometer. Also, we sequenced the metagenomes of the samples in an ion torrent sequencer. The application of EPS did not aid the removal of hydrocarbons with or without the presence of nickel. However, it led to a smaller decrease in the diversity indexes. EPS decreased the abundance of Actinobacteria and increased that of Proteobacteria. The EPS also decreased the connectivity among Actinobacteria in the network analysis. The results indicated that the addition of EPS had a higher effect on the community structure than nickel. Altogether, our results indicate that this approach did not aid the bioremediation of hydrocarbons likely due to its effect in the community structure that affected hydrocarbonoclastic microorganisms.

RevDate: 2021-01-14

Nkansah-Boadu F, Hatam I, SA Baldwin (2021)

Microbial consortia capable of reducing selenate in the presence of nitrate enriched from coalmining-impacted environments.

Applied microbiology and biotechnology [Epub ahead of print].

Biological treatment to remove dissolved selenium from mine-impacted water is often inhibited by the co-contaminant nitrate. In this work, we enriched microbial consortia capable of removing dissolved selenium in the presence of nitrate from native bacteria at sites influenced by coalmine seepages with elevated concentrations of Se, nitrate, and sulfate. Enrichments were collected from sediments in different vegetated or non-vegetated seepage collection ponds, and all demonstrated the potential for dissolved selenium removal. Nitrate inhibited dissolved selenium removal rates in four of these enrichments. However, microorganisms enriched from a mine seepage influenced natural vegetated marsh removed dissolved Se and nitrate simultaneously. Additionally, enrichments from one seepage collection pond achieved enhanced dissolved selenium removal in the presence of nitrate. Based on functional metagenomics, the dominant species with the metabolic capacity for selenate reduction were classified in Orders Enterobacterales and Clostridiales. Most putative selenate reductases identified as either ygfK, associated with selenoprotein synthesis or production of methylated organoselenium compounds, and narG, nitrate reductases with an affinity also for selenate.Key points• Enriched mine influenced sediment bacteria have the capacity for removal of dissolved Se species.• Consortia from a vegetated natural marsh reduced Se without inhibition from nitrate.• Nitrate stimulated the removal of Se by consortia from a disused tailing pond.

RevDate: 2021-01-14

Díaz-Nieto LM, Gil MF, Lazarte JN, et al (2021)

Culex quinquefasciatus carrying Wolbachia is less susceptible to entomopathogenic bacteria.

Scientific reports, 11(1):1094.

In an attempt to evaluate the susceptibility of the mosquito Culex quinquefasciatus to bacterial agents, a population naturally infected with a Wolbachia pipientis wPipSJ native strain was tested against the action of three bacterial mosquitocides, Bacillus thuringiensis subsp. israelensis, Bacillus wiedmannii biovar thuringiensis and Lysinibacillus sphaericus. Tests were carried out on mosquito larvae with and without Wolbachia (controls). Cx. quinquefasciatus naturally infected with the native wPipSJ strain proved to be more resistant to the pathogenic action of the three mosquitocidal bacterial strains. Additionally, wPipSJ was fully characterised using metagenome-assembled genomics, PCR-RFLP (PCR-Restriction Fragment Length Polymorphism) and MLST (MultiLocus Sequence Typing) analyses. This Wolbachia strain wPipSJ belongs to haplotype I, group wPip-III and supergroup B, clustering with other mosquito wPip strains, such as wPip PEL, wPip JHB, wPip Mol, and wAlbB; showing the southernmost distribution in America. The cytoplasmic incompatibility phenotype of this strain was revealed via crosses between wildtype (Wolbachia+) and antibiotic treated mosquito populations. The results of the tests with the bacterial agents suggest that Cx. quinquefasciatus naturally infected with wPipSJ is less susceptible to the pathogenic action of mosquitocidal bacterial strains when compared with the antibiotic-treated mosquito isoline, and is more susceptible to B. thuringiensis subsp. israelensis than to the other two mosquitocidal agents.

RevDate: 2021-01-14

Fishbein SRS, Hink T, Reske KA, et al (2021)

Randomized Controlled Trial of Oral Vancomycin Treatment in Clostridioides difficile-Colonized Patients.

mSphere, 6(1):.

Clostridioides difficile infection (CDI) is most commonly diagnosed using nucleic acid amplification tests (NAAT); the low positive predictive value of these assays results in patients colonized with C. difficile unnecessarily receiving CDI treatment antibiotics. The risks and benefits of antibiotic treatment in individuals with such cases are unknown. Fecal samples of NAAT-positive, toxin enzyme immunoassay (EIA)-negative patients were collected before, during, and after randomization to vancomycin (n = 8) or placebo (n = 7). C. difficile and antibiotic-resistant organisms (AROs) were selectively cultured from fecal and environmental samples. Shotgun metagenomics and comparative isolate genomics were used to understand the impact of oral vancomycin on the microbiome and environmental contamination. Overall, 80% of placebo patients and 71% of vancomycin patients were colonized with C. difficile posttreatment. One person randomized to placebo subsequently received treatment for CDI. In the vancomycin-treated group, beta-diversity (P = 0.0059) and macrolide-lincosamide-streptogramin (MLS) resistance genes (P = 0.037) increased after treatment; C. difficile and vancomycin-resistant enterococci (VRE) environmental contamination was found in 53% of patients and 26% of patients, respectively. We found that vancomycin alters the gut microbiota, does not permanently clear C. difficile, and is associated with VRE colonization/environmental contamination. (This study has been registered at ClinicalTrials.gov under registration no. NCT03388268.)IMPORTANCE A gold standard diagnostic for Clostridioides difficile infection (CDI) does not exist. An area of controversy is how to manage patients whose stool tests positive by nucleic acid amplification tests but negative by toxin enzyme immunoassay. Existing data suggest most of these patients do not have CDI, but most are treated with oral vancomycin. Potential benefits to treatment include a decreased risk for adverse outcomes if the patient does have CDI and the potential to decrease C. difficile shedding/transmission. However, oral vancomycin perturbs the intestinal microbiota and promotes antibiotic-resistant organism colonization/transmission. We conducted a double-blinded randomized controlled trial to assess the risk-benefit of oral vancomycin treatment in this population. Oral vancomycin did not result in long-term clearance of C. difficile, perturbed the microbiota, and was associated with colonization/shedding of vancomycin-resistant enterococci. This work underscores the need to better understand this population of patients in the context of C. difficile/ARO-related outcomes and transmission.

RevDate: 2021-01-14

Lu C, Zhang Z, Cai Z, et al (2021)

Prokaryotic virus host predictor: a Gaussian model for host prediction of prokaryotic viruses in metagenomics.

BMC biology, 19(1):5.

BACKGROUND: Viruses are ubiquitous biological entities, estimated to be the largest reservoirs of unexplored genetic diversity on Earth. Full functional characterization and annotation of newly discovered viruses requires tools to enable taxonomic assignment, the range of hosts, and biological properties of the virus. Here we focus on prokaryotic viruses, which include phages and archaeal viruses, and for which identifying the viral host is an essential step in characterizing the virus, as the virus relies on the host for survival. Currently, the method for determining the viral host is either to culture the virus, which is low-throughput, time-consuming, and expensive, or to computationally predict the viral hosts, which needs improvements at both accuracy and usability. Here we develop a Gaussian model to predict hosts for prokaryotic viruses with better performances than previous computational methods.

RESULTS: We present here Prokaryotic virus Host Predictor (PHP), a software tool using a Gaussian model, to predict hosts for prokaryotic viruses using the differences of k-mer frequencies between viral and host genomic sequences as features. PHP gave a host prediction accuracy of 34% (genus level) on the VirHostMatcher benchmark dataset and a host prediction accuracy of 35% (genus level) on a new dataset containing 671 viruses and 60,105 prokaryotic genomes. The prediction accuracy exceeded that of two alignment-free methods (VirHostMatcher and WIsH, 28-34%, genus level). PHP also outperformed these two alignment-free methods much (24-38% vs 18-20%, genus level) when predicting hosts for prokaryotic viruses which cannot be predicted by the BLAST-based or the CRISPR-spacer-based methods alone. Requiring a minimal score for making predictions (thresholding) and taking the consensus of the top 30 predictions further improved the host prediction accuracy of PHP.

CONCLUSIONS: The Prokaryotic virus Host Predictor software tool provides an intuitive and user-friendly API for the Gaussian model described herein. This work will facilitate the rapid identification of hosts for newly identified prokaryotic viruses in metagenomic studies.

RevDate: 2021-01-14

Bredon M, Depuydt E, Brisson L, et al (2021)

Effects of Dysbiosis and Dietary Manipulation on the Digestive Microbiota of a Detritivorous Arthropod.

Microorganisms, 9(1): pii:microorganisms9010148.

The crucial role of microbes in the evolution, development, health, and ecological interactions of multicellular organisms is now widely recognized in the holobiont concept. However, the structure and stability of microbiota are highly dependent on abiotic and biotic factors, especially in the gut, which can be colonized by transient bacteria depending on the host's diet. We studied these impacts by manipulating the digestive microbiota of the detritivore Armadillidium vulgare and analyzing the consequences on its structure and function. Hosts were exposed to initial starvation and then were fed diets that varied the different components of lignocellulose. A total of 72 digestive microbiota were analyzed according to the type of the diet (standard or enriched in cellulose, lignin, or hemicellulose) and the period following dysbiosis. The results showed that microbiota from the hepatopancreas were very stable and resilient, while the most diverse and labile over time were found in the hindgut. Dysbiosis and selective diets may have affected the host fitness by altering the structure of the microbiota and its predicted functions. Overall, these modifications can therefore have effects not only on the holobiont, but also on the "eco-holobiont" conceptualization of macroorganisms.

RevDate: 2021-01-13

Kant Bhatia S, Vivek N, Kumar V, et al (2020)

Molecular biology interventions for activity improvement and production of industrial enzymes.

Bioresource technology, 324:124596 pii:S0960-8524(20)31870-8 [Epub ahead of print].

Metagenomics and directed evolution technology have brought a revolution in search of novel enzymes from extreme environment and improvement of existing enzymes and tuning them towards certain desired properties. Using advanced tools of molecular biology i.e. next generation sequencing, site directed mutagenesis, fusion protein, surface display, etc. now researchers can engineer enzymes for improved activity, stability, and substrate specificity to meet the industrial demand. Although many enzymatic processes have been developed up to industrial scale, still there is a need to overcome limitations of maintaining activity during the catalytic process. In this article recent developments in enzymes industrial applications and advancements in metabolic engineering approaches to improve enzymes efficacy and production are reviewed.

RevDate: 2021-01-13

Luan Y, Hu H, Liu C, et al (2021)

A Proof-of-concept study of an automated solution for clinical metagenomic Next-Generation Sequencing.

Journal of applied microbiology [Epub ahead of print].

AIMS: Metagenomic next-generation sequencing (mNGS) has been utilized for diagnosing infectious diseases. It is a culture-free and hypothesis-free nucleic acid test for diagnosing all pathogens with known genomic sequences, including bacteria, fungi, viruses, and parasites. While this technique greatly expands the clinical capacity of pathogen detection, it is a second-line choice due to lengthy procedures and microbial contaminations introduced from wet-lab processes. As a result, we aimed to reduce the hands-on time and exogenous contaminations in mNGS.

METHODS AND RESULTS: We developed a device (NGSmaster) that automates the wet-lab workflow, including nucleic acid extraction, PCR-free library preparation and purification. It shortens the sample-to-results time to 16 and 18.5 hours for DNA and RNA sequencing, respectively. We used it to test cultured bacteria for validation of the workflow and bioinformatic pipeline. We also compared PCR-free with PCR-based library prep and discovered no differences in microbial reads. Moreover, we analyzed results by automation and manual testing and found that automation can significantly reduce microbial contaminations. Finally, we tested artificial and clinical samples and showed mNGS results were concordant with traditional culture.

CONCLUSION: NGSmaster can fulfill the microbiological diagnostic needs in a variety of sample types.

This study opens up an opportunity of performing in-house mNGS to reduce turnaround time and workload, instead of transferring potentially contagious specimen to a third-party laboratory.

RevDate: 2021-01-13

Manandhar I, Alimadadi A, Aryal S, et al (2021)

Gut microbiome-based supervised machine learning for clinical diagnosis of inflammatory bowel diseases.

American journal of physiology. Gastrointestinal and liver physiology [Epub ahead of print].

Despite the availability of various diagnostic tests for inflammatory bowel diseases (IBD), misdiagnosis of IBD occurs frequently, and thus there is a clinical need to further improve the diagnosis of IBD. As gut dysbiosis is reported in IBD patients, we hypothesized that supervised machine learning (ML) could be used to analyze gut microbiome data for predictive diagnostics of IBD. To test our hypothesis, fecal 16S metagenomic data of 729 IBD and 700 non-IBD subjects from the American Gut Project were analyzed using five different ML algorithms. Fifty differential bacterial taxa were identified (LEfSe: LDA > 3) between the IBD and non-IBD groups, and ML classifications trained with these taxonomic features using random forest (RF) achieved a testing AUC of ~0.80. Next, we tested if operational taxonomic units (OTUs), instead of bacterial taxa, could be used as ML features for diagnostic classification of IBD. Top 500 high-variance OTUs were used for ML training and an improved testing AUC of ~0.82 (RF) was achieved. Lastly, we tested if supervised ML could be used for differentiating Crohn's disease (CD) and ulcerative colitis (UC). Using 331 CD and 141 UC samples, 117 differential bacterial taxa (LEfSe: LDA > 3) were identified, and the RF model trained with differential taxonomic features or high-variance OTU features achieved a testing AUC > 0.90. In summary, our study demonstrates the promising potential of artificial intelligence via supervised ML modeling for predictive diagnostics of IBD using gut microbiome data.

RevDate: 2021-01-13

Cuna AC, Morowitz MJ, Ahmed I, et al (2021)

Dynamics of the Preterm Gut Microbiome in Health and Disease.

American journal of physiology. Gastrointestinal and liver physiology [Epub ahead of print].

Advances in metagenomics have allowed a detailed study of the gut microbiome, and its role in human health and disease. Infants born prematurely possess a fragile gut microbial ecosystem that is vulnerable to perturbation. Alterations in the developing gut microbiome in preterm infants are linked to life-threatening diseases such as necrotizing enterocolitis (NEC) and late onset sepsis; and may impact future risk of asthma, atopy, obesity, and psychosocial disease. In this mini review, we summarize recent literature on the origins and patterns of development of the preterm gut microbiome in the perinatal period. The host-microbiome-environmental factors that portend development of dysbiotic intestinal microbial patterns associated with NEC and sepsis are reviewed. Strategies to manipulate the microbiome and mitigate dysbiosis, including the use of probiotics and prebiotics will also be discussed. Finally, we explore the challenges and future directions of gut microbiome research in preterm infants.

RevDate: 2021-01-13

Peters BA, Xue X, Wang Z, et al (2021)

Menopausal status and observed differences in the gut microbiome in women with and without HIV infection.

Menopause (New York, N.Y.), Publish Ahead of Print: pii:00042192-900000000-97021 [Epub ahead of print].

OBJECTIVE: Gut microbiota respond to host physiological phenomena, yet little is known regarding shifts in the gut microbiome due to menopausal hormonal and metabolic changes in women. HIV infection impacts menopause and may also cause gut dysbiosis. We therefore sought to determine the association between menopausal status and gut microbiome composition in women with and without HIV.

METHODS: Gut microbiome composition was assessed in stool from 432 women (99 premenopausal HIV+, 71 premenopausal HIV-, 182 postmenopausal HIV+, 80 postmenopausal HIV-) via 16S rRNA gene sequencing. We examined cross-sectional associations of menopause with gut microbiota overall diversity and composition, and taxon and inferred metagenomic pathway abundance. Models were stratified by HIV serostatus and adjusted for age, HIV-related variables, and other potential confounders.

RESULTS: Menopause, ie post- versus premenopausal status, was associated with overall microbial composition only in women with HIV (permutational MANOVA of Jensen Shannon Divergence: P = 0.01). In women with HIV, menopause was associated with enrichment of gram-negative order Enterobacteriales, depletion of highly abundant taxa within Prevotella copri, and alterations in other low-abundance taxa. Additionally, menopause in women with HIV was associated with enrichment of metagenomic pathways related to Enterobacteriales, including degradation of amino acids and phenolic compounds, biosynthesis of enterobactin, and energy metabolism pathways. Menopause-related differences in some low-abundance taxa were also observed in women without HIV.

CONCLUSIONS: A changing gut microbiome may be an overlooked phenomenon of reproductive aging in women with HIV. Longitudinal assessments across all reproductive stages are necessary to confirm these findings and identify health implications.

RevDate: 2021-01-13

Kautsar SA, van der Hooft JJJ, de Ridder D, et al (2021)

BiG-SLiCE: A highly scalable tool maps the diversity of 1.2 million biosynthetic gene clusters.

GigaScience, 10(1):.

BACKGROUND: Genome mining for biosynthetic gene clusters (BGCs) has become an integral part of natural product discovery. The >200,000 microbial genomes now publicly available hold information on abundant novel chemistry. One way to navigate this vast genomic diversity is through comparative analysis of homologous BGCs, which allows identification of cross-species patterns that can be matched to the presence of metabolites or biological activities. However, current tools are hindered by a bottleneck caused by the expensive network-based approach used to group these BGCs into gene cluster families (GCFs).

RESULTS: Here, we introduce BiG-SLiCE, a tool designed to cluster massive numbers of BGCs. By representing them in Euclidean space, BiG-SLiCE can group BGCs into GCFs in a non-pairwise, near-linear fashion. We used BiG-SLiCE to analyze 1,225,071 BGCs collected from 209,206 publicly available microbial genomes and metagenome-assembled genomes within 10 days on a typical 36-core CPU server. We demonstrate the utility of such analyses by reconstructing a global map of secondary metabolic diversity across taxonomy to identify uncharted biosynthetic potential. BiG-SLiCE also provides a "query mode" that can efficiently place newly sequenced BGCs into previously computed GCFs, plus a powerful output visualization engine that facilitates user-friendly data exploration.

CONCLUSIONS: BiG-SLiCE opens up new possibilities to accelerate natural product discovery and offers a first step towards constructing a global and searchable interconnected network of BGCs. As more genomes are sequenced from understudied taxa, more information can be mined to highlight their potentially novel chemistry. BiG-SLiCE is available via https://github.com/medema-group/bigslice.

RevDate: 2021-01-13

Pabbathi NPP, Velidandi A, Tavarna T, et al (2021)

Role of metagenomics in prospecting novel endoglucanases, accentuating functional metagenomics approach in second-generation biofuel production: a review.

Biomass conversion and biorefinery pii:1186 [Epub ahead of print].

As the fossil fuel reserves are depleting rapidly, there is a need for alternate fuels to meet the day to day mounting energy demands. As fossil fuel started depleting, a quest for alternate forms of fuel was initiated and biofuel is one of its promising outcomes. First-generation biofuels are made from edible sources like vegetable oils, starch, and sugars. Second-generation biofuels (SGB) are derived from lignocellulosic crops and the third-generation involves algae for biofuel production. Technical challenges in the production of SGB are hampering its commercialization. Advanced molecular technologies like metagenomics can help in the discovery of novel lignocellulosic biomass-degrading enzymes for commercialization and industrial production of SGB. This review discusses the metagenomic outcomes to enlighten the importance of unexplored habitats for novel cellulolytic gene mining. It also emphasizes the potential of different metagenomic approaches to explore the uncultivable cellulose-degrading microbiome as well as cellulolytic enzymes associated with them. This review also includes effective pre-treatment technology and consolidated bioprocessing for efficient biofuel production.

RevDate: 2021-01-13

Shukla PK, Meena AS, Dalal K, et al (2021)

Chronic stress and corticosterone exacerbate alcohol-induced tissue injury in the gut-liver-brain axis.

Scientific reports, 11(1):826.

Alcohol use disorders are associated with altered stress responses, but the impact of stress or stress hormones on alcohol-associated tissue injury remain unknown. We evaluated the effects of chronic restraint stress on alcohol-induced gut barrier dysfunction and liver damage in mice. To determine whether corticosterone is the stress hormone associated with the stress-induced effects, we evaluated the effect of chronic corticosterone treatment on alcoholic tissue injury at the Gut-Liver-Brain (GLB) axis. Chronic restraint stress synergized alcohol-induced epithelial tight junction disruption and mucosal barrier dysfunction in the mouse intestine. These effects of stress on the gut were reproduced by corticosterone treatment. Corticosterone synergized alcohol-induced expression of inflammatory cytokines and chemokines in the colonic mucosa, and it potentiated the alcohol-induced endotoxemia and systemic inflammation. Corticosterone also potentiated alcohol-induced liver damage and neuroinflammation. Metagenomic analyses of 16S RNA from fecal samples indicated that corticosterone modulates alcohol-induced changes in the diversity and abundance of gut microbiota. In Caco-2 cell monolayers, corticosterone dose-dependently potentiated ethanol and acetaldehyde-induced tight junction disruption and barrier dysfunction. These data indicate that chronic stress and corticosterone exacerbate alcohol-induced mucosal barrier dysfunction, endotoxemia, and systemic alcohol responses. Corticosterone-mediated promotion of alcohol-induced intestinal epithelial barrier dysfunction and modulation of gut microbiota may play a crucial role in the mechanism of stress-induced promotion of alcohol-associated tissue injury at the GLB axis.

RevDate: 2021-01-13

Tláskal V, Brabcová V, Větrovský T, et al (2021)

Complementary Roles of Wood-Inhabiting Fungi and Bacteria Facilitate Deadwood Decomposition.

mSystems, 6(1):.

Forests accumulate and store large amounts of carbon (C), and a substantial fraction of this stock is contained in deadwood. This transient pool is subject to decomposition by deadwood-associated organisms, and in this process it contributes to CO2 emissions. Although fungi and bacteria are known to colonize deadwood, little is known about the microbial processes that mediate carbon and nitrogen (N) cycling in deadwood. In this study, using a combination of metagenomics, metatranscriptomics, and nutrient flux measurements, we demonstrate that the decomposition of deadwood reflects the complementary roles played by fungi and bacteria. Fungi were found to dominate the decomposition of deadwood and particularly its recalcitrant fractions, while several bacterial taxa participate in N accumulation in deadwood through N fixation, being dependent on fungal activity with respect to deadwood colonization and C supply. Conversely, bacterial N fixation helps to decrease the constraints of deadwood decomposition for fungi. Both the CO2 efflux and N accumulation that are a result of a joint action of deadwood bacteria and fungi may be significant for nutrient cycling at ecosystem levels. Especially in boreal forests with low N stocks, deadwood retention may help to improve the nutritional status and fertility of soils.IMPORTANCE Wood represents a globally important stock of C, and its mineralization importantly contributes to the global C cycle. Microorganisms play a key role in deadwood decomposition, since they possess enzymatic tools for the degradation of recalcitrant plant polymers. The present paradigm is that fungi accomplish degradation while commensalist bacteria exploit the products of fungal extracellular enzymatic cleavage, but this assumption was never backed by the analysis of microbial roles in deadwood. This study clearly identifies the roles of fungi and bacteria in the microbiome and demonstrates the importance of bacteria and their N fixation for the nutrient balance in deadwood as well as fluxes at the ecosystem level. Deadwood decomposition is shown as a process where fungi and bacteria play defined, complementary roles.

RevDate: 2021-01-13

Meier DV, Imminger S, Gillor O, et al (2021)

Distribution of Mixotrophy and Desiccation Survival Mechanisms across Microbial Genomes in an Arid Biological Soil Crust Community.

mSystems, 6(1):.

Desert surface soils devoid of plant cover are populated by a variety of microorganisms, many with yet unresolved physiologies and lifestyles. Nevertheless, a common feature vital for these microorganisms inhabiting arid soils is their ability to survive long drought periods and reactivate rapidly in rare incidents of rain. Chemolithotrophic processes such as oxidation of atmospheric hydrogen and carbon monoxide are suggested to be a widespread energy source to support dormancy and resuscitation in desert soil microorganisms. Here, we assessed the distribution of chemolithotrophic, phototrophic, and desiccation-related metabolic potential among microbial populations in arid biological soil crusts (BSCs) from the Negev Desert, Israel, via population-resolved metagenomic analysis. While the potential to utilize light and atmospheric hydrogen as additional energy sources was widespread, carbon monoxide oxidation was less common than expected. The ability to utilize continuously available energy sources might decrease the dependency of mixotrophic populations on organic storage compounds and carbon provided by the BSC-founding cyanobacteria. Several populations from five different phyla besides the cyanobacteria encoded CO2 fixation potential, indicating further potential independence from photoautotrophs. However, we also found population genomes with a strictly heterotrophic genetic repertoire. The highly abundant Rubrobacteraceae (Actinobacteriota) genomes showed particular specialization for this extreme habitat, different from their closest cultured relatives. Besides the ability to use light and hydrogen as energy sources, they encoded extensive O2 stress protection and unique DNA repair potential. The uncovered differences in metabolic potential between individual, co-occurring microbial populations enable predictions of their ecological niches and generation of hypotheses on the dynamics and interactions among them.IMPORTANCE This study represents a comprehensive community-wide genome-centered metagenome analysis of biological soil crust (BSC) communities in arid environments, providing insights into the distribution of genes encoding different energy generation mechanisms, as well as survival strategies, among populations in an arid soil ecosystem. It reveals the metabolic potential of several uncultured and previously unsequenced microbial genera, families, and orders, as well as differences in the metabolic potential between the most abundant BSC populations and their cultured relatives, highlighting once more the danger of inferring function on the basis of taxonomy. Assigning functional potential to individual populations allows for the generation of hypotheses on trophic interactions and activity patterns in arid soil microbial communities and represents the basis for future resuscitation and activity studies of the system, e.g., involving metatranscriptomics.

RevDate: 2021-01-13

Griesenauer B, González-Beiras C, Fortney KR, et al (2021)

Streptococcus pyogenes Is Associated with Idiopathic Cutaneous Ulcers in Children on a Yaws-Endemic Island.

mBio, 12(1):.

Exudative cutaneous ulcers (CU) in yaws-endemic areas are associated with Treponema pallidum subsp. pertenue (TP) and Haemophilus ducreyi (HD), but one-third of CU cases are idiopathic (IU). Using mass drug administration (MDA) of azithromycin, a yaws eradication campaign on Lihir Island in Papua New Guinea reduced but failed to eradicate yaws; IU rates remained constant throughout the campaign. To identify potential etiologies of IU, we obtained swabs of CU lesions (n = 279) and of the skin of asymptomatic controls (AC; n = 233) from the Lihir Island cohort and characterized their microbiomes using a metagenomics approach. CU bacterial communities were less diverse than those of the AC. Using real-time multiplex PCR with pathogen-specific primers, we separated CU specimens into HD-positive (HD+), TP+, HD+TP+, and IU groups. Each CU subgroup formed a distinct bacterial community, defined by the species detected and/or the relative abundances of species within each group. Streptococcus pyogenes was the most abundant organism in IU (22.65%) and was enriched in IU compared to other ulcer groups. Follow-up samples (n = 31) were obtained from nonhealed ulcers; the average relative abundance of S. pyogenes was 30.11% in not improved ulcers and 0.88% in improved ulcers, suggesting that S. pyogenes in the not improved ulcers may be azithromycin resistant. Catonella morbi was enriched in IU that lacked S. pyogenes As some S. pyogenes and TP strains are macrolide resistant, penicillin may be the drug of choice for CU azithromycin treatment failures. Our study will aid in the design of diagnostic tests and selective therapies for CU.IMPORTANCE Cutaneous ulcers (CU) affect approximately 100,000 children in the tropics each year. While two-thirds of CU are caused by Treponema pallidum subspecies pertenue and Haemophilus ducreyi, the cause(s) of the remaining one-third is unknown. Given the failure of mass drug administration of azithromycin to eradicate CU, the World Health Organization recently proposed an integrated disease management strategy to control CU. Success of this strategy requires determining the unknown cause(s) of CU. By using 16S rRNA gene sequencing of swabs obtained from CU and the skin of asymptomatic children, we identified another possible cause of skin ulcers, Streptococcus pyogenes Although S. pyogenes is known to cause impetigo and cellulitis, this is the first report implicating the organism as a causal agent of CU. Inclusion of S. pyogenes into the integrated disease management plan will improve diagnostic testing and treatment of this painful and debilitating disease of children and strengthen elimination efforts.

RevDate: 2021-01-13

Bellas CM, R Sommaruga (2021)

Polinton-like viruses are abundant in aquatic ecosystems.

Microbiome, 9(1):13.

BACKGROUND: Polintons are large mobile genetic elements found in the genomes of eukaryotic organisms that are considered the ancient ancestors of most eukaryotic dsDNA viruses. Originally considered as transposons, they have been found to encode virus capsid genes, suggesting they may actually be integrated viruses; however, an extracellular form has yet to be detected. Recently, circa 25 Polinton-like viruses have been discovered in environmental metagenomes and algal genomes, which shared distantly related genes to both Polintons and virophages (Lavidaviridae). These entities could be the first members of a major class of ancient eukaryotic viruses; however, owing to the lack of available genomes for analysis, information on their global diversity, evolutionary relationships, eukaryotic hosts, and status as free virus particles is limited.

RESULTS: Here, we analysed the metaviromes of an alpine lake to show that Polinton-like virus genome sequences are abundant in the water column. We identify major capsid protein genes belonging to 82 new Polinton-like viruses and use these to interrogate publicly available metagenomic datasets, identifying 543 genomes and a further 16 integrated into eukaryotic genomes. Using an analysis of shared gene content and major capsid protein phylogeny, we define large groups of Polinton-like viruses and link them to diverse eukaryotic hosts, including a new group of viruses, which possess all the core genes of virophages and infect oomycetes and Chrysophyceae.

CONCLUSIONS: Our study increased the number of known Polinton-like viruses by 25-fold, identifying five major new groups of eukaryotic viruses, which until now have been hidden in metagenomic datasets. The large enrichment (> 100-fold) of Polinton-like virus sequences in the virus-sized fraction of this alpine lake and the fact that their viral major capsid proteins are found in eukaryotic host transcriptomes support the hypothesis that Polintons in unicellular eukaryotes are viruses. In summary, our data reveals a diverse assemblage of globally distributed viruses, associated with a wide range of unicellular eukaryotic hosts. We anticipate that the methods we have developed for Polinton-like virus detection and the database of over 20,000 genes we present will allow for continued discovery and analysis of these new viral groups. Video abstract.

RevDate: 2021-01-13

Liu J, Liu C, J Yue (2021)

Radiotherapy and the gut microbiome: facts and fiction.

Radiation oncology (London, England), 16(1):9.

An ever-growing body of evidence has linked the gut microbiome with both the effectiveness and the toxicity of cancer therapies. Radiotherapy is an effective way to treat tumors, although large variations exist among patients in tumor radio-responsiveness and in the incidence and severity of radiotherapy-induced side effects. Relatively little is known about whether and how the microbiome regulates the response to radiotherapy. Gut microbiota may be an important player in modulating "hot" versus "cold" tumor microenvironment, ultimately affecting treatment efficacy. The interaction of the gut microbiome and radiotherapy is a bidirectional function, in that radiotherapy can disrupt the microbiome and those disruptions can influence the effectiveness of the anticancer treatments. Limited data have shown that interactions between the radiation and the microbiome can have positive effects on oncotherapy. On the other hand, exposure to ionizing radiation leads to changes in the gut microbiome that contribute to radiation enteropathy. The gut microbiome can influence radiation-induced gastrointestinal mucositis through two mechanisms including translocation and dysbiosis. We propose that the gut microbiome can be modified to maximize the response to treatment and minimize adverse effects through the use of personalized probiotics, prebiotics, or fecal microbial transplantation. 16S rRNA sequencing is the most commonly used approach to investigate distribution and diversity of gut microbiome between individuals though it only identifies bacteria level other than strain level. The functional gut microbiome can be studied using methods involving metagenomics, metatranscriptomics, metaproteomics, as well as metabolomics. Multiple '-omic' approaches can be applied simultaneously to the same sample to obtain integrated results. That said, challenges and remaining unknowns in the future that persist at this time include the mechanisms by which the gut microbiome affects radiosensitivity, interactions between the gut microbiome and combination treatments, the role of the gut microbiome with regard to predictive and prognostic biomarkers, the need for multi "-omic" approach for in-depth exploration of functional changes and their effects on host-microbiome interactions, and interactions between gut microbiome, microbial metabolites and immune microenvironment.

RevDate: 2021-01-13

Duan H, Li X, Mei A, et al (2021)

The diagnostic value of metagenomic next⁃generation sequencing in infectious diseases.

BMC infectious diseases, 21(1):62.

BACKGROUND: Although traditional diagnostic techniques of infection are mature and price favorable at present, most of them are time-consuming and with a low positivity. Metagenomic next⁃generation sequencing (mNGS) was studied widely because of identification and typing of all pathogens not rely on culture and retrieving all DNA without bias. Based on this background, we aim to detect the difference between mNGS and traditional culture method, and to explore the relationship between mNGS results and the severity, prognosis of infectious patients.

METHODS: 109 adult patients were enrolled in our study in Shanghai Tenth People's Hospital from October 2018 to December 2019. The diagnostic results, negative predictive values, positive predictive values, false positive rate, false negative rate, pathogen and sample types were analyzed by using both traditional culture and mNGS methods. Then, the samples and clinical information of 93 patients in the infected group (ID) were collected. According to whether mNGS detected pathogens, the patients in ID group were divided into the positive group of 67 cases and the negative group of 26 cases. Peripheral blood leukocytes, C-reactive protein (CRP), procalcitonin (PCT) and neutrophil counts were measured, and the concentrations of IL-2, IL-4, IL-6, TNF-α, IL-17A, IL-10 and INF-γ in the serum were determined by ELISA. The correlation between the positive detection of pathogens by mNGS and the severity of illness, hospitalization days, and mortality were analyzed.

RESULTS: 109 samples were assigned into infected group (ID, 92/109, 84.4%), non-infected group (NID, 16/109, 14.7%), and unknown group (1/109, 0.9%). Blood was the most abundant type of samples with 37 cases, followed by bronchoalveolar lavage fluid in 36 cases, tissue, sputum, pleural effusion, cerebrospinal fluid (CSF), pus, bone marrow and nasal swab. In the ID group, the majority of patients were diagnosed with lower respiratory system infections (73/109, 67%), followed by bloodstream infections, pleural effusion and central nervous system infections. The sensitivity of mNGS was significantly higher than that of culture method (67.4% vs 23.6%; P < 0.001), especially in sample types of bronchoalveolar lavage fluid (P = 0.002), blood (P < 0.001) and sputum (P = 0.037), while the specificity of mNGS was not significantly different from culture method (68.8% vs 81.3%; P = 0.41). The number of hospitals stays and 28-day-motality in the positive mNGS group were significantly higher than those in the negative group, and the difference was statistically significant (P < 0.05). Age was significant in multivariate logistic analyses of positive results of mNGS.

CONCLUSIONS: The study found that mNGS had a higher sensitivity than the traditional method, especially in blood, bronchoalveolar lavage fluid and sputum samples. And positive mNGS group had a higher hospital stay, 28-day-mortality, which means the positive of pathogen nucleic acid sequences detection may be a potential high-risk factor for poor prognosis of adult patients and has significant clinical value. MNGS should be used more in early pathogen diagnosis in the future.

RevDate: 2021-01-12

Pan J, Huo T, Yang H, et al (2021)

Metabolic patterns reveal enhanced anammox activity at low-nitrogen conditions in the integrated I-ABR.

Water environment research : a research publication of the Water Environment Federation [Epub ahead of print].

Substrate concentrations greatly influence bacterial growth and metabolism. However, optimal nitrogen concentrations for anammox bacteria in nitrogen-limited environments remain unclear. Here, we observed enhanced nitrogen metabolism and anabolism of anammox bacteria at low-nitrogen conditions. Efficient nitrogen removal was achieved at ammonium and nitrite influent concentration of 30 mg/L under HRT of 1h, with an average nitrogen removal rate (NRR) of 0.73 kg N/(m3 ·d) in I-ABR composed of four compartments. The highest anammox activity of 6.25 mmol N/ (gVSS·h) was observed in the fourth compartment (C4) with the lowest substrate levels (ammonium and nitrite of 11.6 mg/L and 7 mg/L). This could be resulted from the highest expression level of genes involved in nitrogen metabolism in C4, which was 1.49-1.67 times higher than that in other compartments. Besides, the second compartment (C2) exhibited the most active anabolism at ammonium and nitrite of 17 mg/L and 13 mg/L, respectively, which contributed to the most active amino acid synthesis and thus the highest EPS (1.35 times higher) in C2. This enhanced amino acid auxotrophy between anammox bacteria with heterotrophs, and consequently, heterotrophs thrived and competed for nitrite. These results hint at the potential application of anammox process in micro-polluted water.

RevDate: 2021-01-13
CmpDate: 2021-01-13

Malakar D, Sarathbabu S, Borah P, et al (2021)

Fish gill microbiome from India's largest Brahmaputra River-a trans-border biodiversity hotspot region.

Environmental monitoring and assessment, 193(2):56 pii:10.1007/s10661-021-08847-z.

In this study, we sequenced the V3-V4 region of 16S rRNA gene amplicon using paired-end Illumina HiSeq to study the bacterial community in the gills of fish from the bank of the trans-border river of Brahmaputra, Northeast India. Metagenome data consisted of 278,784 reads, 248-bp length, and 56.48% GC content with 85% sequence having a Phred score Q = 30. Community metagenomics revealed a total of 631 genera belonging to 22 different phyla, dominated by Proteobacteria (118,222 features), Firmicutes (101,043 features), Actinobacteria (34,189 features), Bacteroidetes (17,977 features), and Cyanobacteria (2730 features). The bacterial community identified was composed of both pathogenic zoonotic and non-harmful groups. The pathway or functional analysis of the fish gill microbiome exhibited 21 different pathways which also included the pathogenic-related functions. Our data detected a wide group of bacterial communities that will be useful in further isolating and characterizing the pathogenic bacteria from the fish and also to understand the bacterial association in highly consumed fish.

RevDate: 2021-01-12

Asnicar F, Berry SE, Valdes AM, et al (2021)

Microbiome connections with host metabolism and habitual diet from 1,098 deeply phenotyped individuals.

Nature medicine [Epub ahead of print].

The gut microbiome is shaped by diet and influences host metabolism; however, these links are complex and can be unique to each individual. We performed deep metagenomic sequencing of 1,203 gut microbiomes from 1,098 individuals enrolled in the Personalised Responses to Dietary Composition Trial (PREDICT 1) study, whose detailed long-term diet information, as well as hundreds of fasting and same-meal postprandial cardiometabolic blood marker measurements were available. We found many significant associations between microbes and specific nutrients, foods, food groups and general dietary indices, which were driven especially by the presence and diversity of healthy and plant-based foods. Microbial biomarkers of obesity were reproducible across external publicly available cohorts and in agreement with circulating blood metabolites that are indicators of cardiovascular disease risk. While some microbes, such as Prevotella copri and Blastocystis spp., were indicators of favorable postprandial glucose metabolism, overall microbiome composition was predictive for a large panel of cardiometabolic blood markers including fasting and postprandial glycemic, lipemic and inflammatory indices. The panel of intestinal species associated with healthy dietary habits overlapped with those associated with favorable cardiometabolic and postprandial markers, indicating that our large-scale resource can potentially stratify the gut microbiome into generalizable health levels in individuals without clinically manifest disease.

RevDate: 2021-01-12

Lee SH, Cho SY, Yoon Y, et al (2021)

Bifidobacterium bifidum strains synergize with immune checkpoint inhibitors to reduce tumour burden in mice.

Nature microbiology [Epub ahead of print].

The gut microbiome can influence the development of tumours and the efficacy of cancer therapeutics1-5; however, the multi-omics characteristics of antitumour bacterial strains have not been fully elucidated. In this study, we integrated metagenomics, genomics and transcriptomics of bacteria, and analyses of mouse intestinal transcriptome and serum metabolome data to reveal an additional mechanism by which bacteria determine the efficacy of cancer therapeutics. In gut microbiome analyses of 96 samples from patients with non-small-cell lung cancer, Bifidobacterium bifidum was abundant in patients responsive to therapy. However, when we treated syngeneic mouse tumours with commercial strains of B. bifidum to establish relevance for potential therapeutic uses, only specific B. bifidum strains reduced tumour burden synergistically with PD-1 blockade or oxaliplatin treatment by eliciting an antitumour host immune response. In mice, these strains induced tuning of the immunological background by potentiating the production of interferon-γ, probably through the enhanced biosynthesis of immune-stimulating molecules and metabolites.

RevDate: 2021-01-12

Debesa-Tur G, Pérez-Brocal V, Ruiz-Ruiz S, et al (2021)

Metagenomic analysis of formalin-fixed paraffin-embedded tumor and normal mucosa reveals differences in the microbiome of colorectal cancer patients.

Scientific reports, 11(1):391.

An increased risk of developing colorectal cancer (CRC) and other types of tumor is associated to Lynch syndrome (LS), an inherited condition caused by germline mutations in mismatch repair genes. We selected a cohort of LS patients that had developed CRC and had undergone surgical resection. Formalin-fixed paraffin embedded (FFPE) tissue blocks from matched colorectal and normal mucosa were used for genomic DNA extraction with a commercial kit and sequenced by high-throughput sequencing. A metagenomic approach enabled the taxonomic and functional identification of the microbial community and associated genes detected in the specimens. Slightly lower taxonomic diversity was observed in the tumor compared to the non-tumor tissue. Furthermore, the most remarkable differences between tumors and healthy tissue was the significant increase in the genus Fusobacterium in the former, in particular the species F. nucleatum, as well as Camplylobacter or Bacteroides fragilis, in accordance with previous studies of CRC. However, unlike prior studies, the present work is not based on directed detection by qPCR but instead uses a metagenomic approach to retrieve the whole bacterial community, and addresses the additional difficulty of using long-term stored FFPE samples.

RevDate: 2021-01-12

Ma C, Chen K, Wang Y, et al (2021)

Establishing a novel colorectal cancer predictive model based on unique gut microbial single nucleotide variant markers.

Gut microbes, 13(1):1-6.

Current metagenomic species-based colorectal cancer (CRC) microbial biomarkers may confuse diagnosis because the genetic content of different microbial strains, even those belonging to the same species, may differ from 5% to 30%. Here, a total of 7549 non-redundant single nucleotide variants (SNVs) were annotated in 25 species from 3 CRC cohorts (n = 249). Then, 22 microbial SNV markers that contributed to distinguishing subjects with CRC from healthy subjects were identified by the random forest algorithm to construct a novel CRC predictive model. Excitingly, the predictive model showed high accuracy both in the training (AUC = 75.35%) and validation cohorts (AUC = 73.08%-88.02%). We further explored the specificity of these SNV markers in a broader background by performing a meta-analysis across 4 metabolic disease cohorts. Among these SNV markers, 3 SNVs that were enriched in CRC patients and located in the genomes of Eubacterium rectale and Faecalibacterium prausnitzii were CRC specific (AUC = 72.51%-94.07%).

RevDate: 2021-01-13

Anonymous (2020)

Corrigendum to: Gut metagenomics-derived genes as potential biomarkers of Parkinson's disease.

Brain : a journal of neurology, 143(12):e109.

RevDate: 2021-01-11

Zhao W, Ren Z, Luo Y, et al (2021)

Metagenomics analysis of the gut microbiome in healthy and bacterial pneumonia forest musk deer.

Genes & genomics [Epub ahead of print].

BACKGROUND: The forest musk deer (FMD, Moschus berezovskii) is an threatened species in China. Bacterial pneumonia was found to seriously restrict the development of FMD captive breeding. Historical evidence has demonstrated the relationship between immune system and intestinal Lactobacillus in FMD.

OBJECTIVE: We sought to elucidate the differences in the gut microbiota of healthy and bacterial pneumonia FMD.

METHODS: The bacterial pneumonia FMD was demonstrated by bacterial and pathological diagnosis, and the gut microbiome of healthy and bacterial pneumonia FMD was sequenced and analysed.

RESULTS: There are three pathogens (Pseudomonas aeruginosa, Streptococcus equinus and Trueperella pyogenes) isolated from the bacterial pneumonia FMD individuals. Compared with the healthy group, the abundance of Firmicutes and Proteobacteria in the pneumonia group was changed, and a high level of Proteobacteria was found in the pneumonia group. In addition, a higher abundance of Acinetobacter (p = 0.01) was observed in the population of the pneumonia group compared with the healthy group. Several potentially harmful bacteria and disease-related KEGG subsystems were only found in the gut of the bacterial pneumonia group. Analysis of KEGG revealed that many genes related to type IV secretion system, type IV pilus, lipopolysaccharide export system, HTH-type transcriptional regulator/antitoxin MqsA, and ArsR family transcriptional regulator were significantly enriched in the metagenome of the bacterial pneumonia FMD.

CONCLUSION: Our results demonstrated that the gut microbiome was significantly altered in the bacterial pneumonia group. Overall, our research improves the understanding of the potential role of the gut microbiota in the FMD bacterial pneumonia.

RevDate: 2021-01-11

Demirci H, Kurt-Gur G, E Ordu (2021)

Microbiota profiling and screening of the lipase active halotolerant yeasts of the olive brine.

World journal of microbiology & biotechnology, 37(2):23.

Searching for novel enzymes that could be active in organic solvents has become an area of interest in recent years. Olive brine naturally provides a suitable environment for the survival of halophilic and acidophilic microorganisms and the resulting genome is thought to be a gene source for determining the halophilic and acidophilic proteins that are active in a non-aqueous organic solvent medium, and so it has been used in several biotechnological and industrial applications. In this study, microbial analysis of natural, cracked green olive brine from the southern region of Turkey has been made by next-generation sequencing of the brine metagenome for the first time in the literature. The number of reads assigned to fungal operational taxonomic units was the highest percentage (73.04%) with the dominant representation of Ascomycota phylum (99% of fungi). Bacterial OTU was 3.56% of the reads and Proteobacteria phylum was 65% of the reads. The lipase production capacity of the yeasts that were grown on the media containing elevated concentrations of NaCl (1-3 M) was determined on a Rhodamine B-including medium. Molecular identification of the selected yeasts was performed and 90% of sequenced yeasts had a high level of similarity with Candida diddensiae, whereas 10% showed similarity to Candida boidinii. The hydrolytic lipase activities using olive oil were analyzed and both yeasts showed cell-bound lipase activity at pH 3.0.

RevDate: 2021-01-11

Mulualem DM, Agbavwe C, Ogilvie LA, et al (2021)

Metagenomic identification, purification and characterisation of the Bifidobacterium adolescentis BgaC β-galactosidase.

Applied microbiology and biotechnology [Epub ahead of print].

Members of the human gut microbiota use glycoside hydrolase (GH) enzymes, such as β-galactosidases, to forage on host mucin glycans and dietary fibres. A human faecal metagenomic fosmid library was constructed and functionally screened to identify novel β-galactosidases. Out of the 16,000 clones screened, 30 β-galactosidase-positive clones were identified. The β-galactosidase gene found in the majority of the clones was BAD_1582 from Bifidobacterium adolescentis, subsequently named bgaC. This gene was cloned with a hexahistidine tag, expressed in Escherichia coli and His-tagged-BgaC was purified using Ni2+-NTA affinity chromatography and size filtration. The enzyme had optimal activity at pH 7.0 and 37 °C, with a wide range of pH (4-10) and temperature (0-40 °C) stability. It required a divalent metal ion co-factor; maximum activity was detected with Mg2+, while Cu2+ and Mn2+ were inhibitory. Kinetic parameters were determined using ortho-nitrophenyl-β-D-galactopyranoside (ONPG) and lactose substrates. BgaC had a Vmax of 107 μmol/min/mg and a Km of 2.5 mM for ONPG and a Vmax of 22 μmol/min/mg and a Km of 3.7 mM for lactose. It exhibited low product inhibition by galactose with a Ki of 116 mM and high tolerance for glucose (66% activity retained in presence of 700 mM glucose). In addition, BgaC possessed transglycosylation activity to produce galactooligosaccharides (GOS) from lactose, as determined by TLC and HPLC analysis. The enzymatic characteristics of B. adolescentis BgaC make it an ideal candidate for dairy industry applications and prebiotic manufacture.Key points• Bifidobacterium adolescentis BgaC β-galactosidase was selected from human faecal metagenome.• BgaC possesses sought-after properties for biotechnology, e.g. low product inhibition.• BgaC has transglycosylation activity producing prebiotic oligosaccharides. Graphical Abstract.

RevDate: 2021-01-11

Hoang HT, Le DH, Le TTH, et al (2021)

Metagenomic 16S rDNA amplicon data of microbial diversity of guts in Vietnamese humans with type 2 diabetes and nondiabetic adults.

Data in brief, 34:106690 pii:S2352-3409(20)31569-9.

Type 2 diabetes mellitus (T2DM) is an important public health problem. The knowledge of bacterial communities in the gut of Vietnamese patients with T2DM and non diabetic controls is still insufficient. We report in this article the 16S rDNA amplicon data of the gut microbiomes of Vietnamese patients with T2DM and nondiabetic controls carried out using the Illumina sequencing. This work included 7 patients and 7 controls. A total of 1,627,646 reads were obtained and a total of 13 phyla, 25 classes, 94 genera were revealed. The top three dominant bacterial phyla in all subjects were Firmicutes, Bacteroidetes and Proteobacteria. Significant differences in the relative abundances of the phylum Firmicutes and class Clostridia between patients and controls were observed, suggesting that the reducing of phylum Firmicutes and class Clostridia in the gut may be linked to obesity and T2DM. All sequencing libraries were deposited in the NCBI SRA as BioProject PRJNA668251. The datasets are needed to determine the association between the bacterial composition of the gut and the pathogenesis of T2DM in Vietnamese patients.

RevDate: 2021-01-11

Chen B, Liu S, Feng D, et al (2020)

Vitamin A Deficiency in the Early-Life Periods Alters a Diversity of the Colonic Mucosal Microbiota in Rats.

Frontiers in nutrition, 7:580780.

Vitamin A deficiency (VAD) remains a public health issue worldwide, affecting pregnant women and children. The early-life microbiota is a potentially effective intervention target for modulating immune and metabolic development of the host. This paper investigates the effects of VAD during different life periods on the structure of the colonic mucosa microbiota in adolescent rats. The results showed that the concentrations of serum retinol were > ~1.05 μmol/L in maternal VA normal (VAN)rats and < 0.7 μmol/L in maternal VAD rats, while the serum retinol levels were higher than 0.7 μmol/L in the pups of the VAN group and below 0.5 μmol/L in the pups of the VAD group. Compared to the offspring persistent with VAN from embryonic stage (group A), all the remaining groups exhibited an increased ratio of Firmicutes/Bacteroidetes abundance. A metagenome analysis (LEfSe) and a differentially abundant features approach using Metastats for genus abundances revealed that Diaphorobacter and Psychrobacter were increased in the offspring persistent with VAD from embryonic stage (group B);Bifidobacterium was decreased and Staphylococcus was increased in the offspring with VAD after weaning (group C); Propionibacterium and Enterobacter were increased significantly in the offspring with VAD during gestation(group E); and Ochrobactrum was increased in group B and the offspring with VAD during gestation and lactation(group D). Faecalibacterium abundance was significantly and positively related to serum retinol levels, while that of Staphylococcus was significantly and negatively correlated with serum retinol levels. VAD in different life periods can alter the gut microbiome in rats, but VAD in the early-life periods (especially gestation and/or lactation) leads to a diversity of the colonic mucosal microbiota in adolescent rats as well as an imbalance of the ratio between Firmicutes and Bacteroidetes. The early-life period may become a time window of VA intervention to improve intestinal microbiota caused by VA deficiency, but the specific mechanism requires more in-depth research.

RevDate: 2021-01-11

Komatsu K, Shiba T, Takeuchi Y, et al (2020)

Discriminating Microbial Community Structure Between Peri-Implantitis and Periodontitis With Integrated Metagenomic, Metatranscriptomic, and Network Analysis.

Frontiers in cellular and infection microbiology, 10:596490.

Peri-implantitis and periodontitis are both polymicrobial diseases induced by subgingival plaque accumulation, with some differing clinical features. Studies on the microbial and gene transcription activity of peri-implantitis microbiota are limited. This study aimed to verify the hypothesis that disease-specific microbial and gene transcription activity lead to disease-specific clinical features, using an integrated metagenomic, metatranscriptomic, and network analysis. Metagenomic data in peri-implantitis and periodontitis were obtained from the same 21 subjects and metatranscriptomic data from 12 subjects were obtained from a database. The microbial co-occurrence network based on metagenomic analysis had more diverse species taxa and correlations than the network based on the metatranscriptomic analysis. Solobacterium moorei and Prevotella denticola had high activity and were core species taxa specific to peri-implantitis in the co-occurrence network. Moreover, the activity of plasmin receptor/glyceraldehyde-3-phosphate dehydrogenase genes was higher in peri-implantitis. These activity differences may increase complexity in the peri-implantitis microbiome and distinguish clinical symptoms of the two diseases. These findings should help in exploring a novel biomarker that assist in the diagnosis and preventive treatment design of peri-implantitis.

RevDate: 2021-01-11

El Jaddaoui I, Allali I, Sehli S, et al (2020)

Cancer Omics in Africa: Present and Prospects.

Frontiers in oncology, 10:606428.

During the last century, cancer biology has been arguably one of the most investigated research fields. To gain deeper insight into cancer mechanisms, scientists have been attempting to integrate multi omics data in cancer research. Cancer genomics, transcriptomics, metabolomics, proteomics, and metagenomics are the main multi omics strategies used currently in the diagnosis, prognosis, treatment, and biomarker discovery in cancer. In this review, we describe the use of different multi omics strategies in cancer research in the African continent and discuss the main challenges facing the implementation of these approaches in African countries such as the lack of training programs in bioinformatics in general and omics strategies in particular and suggest paths to address deficiencies. As a way forward, we advocate for the establishment of an "African Cancer Genomics Consortium" to promote intracontinental collaborative projects and enhance engagement in research activities that address indigenous aspects for cancer precision medicine.

RevDate: 2021-01-11

Zhou S, Luo R, Gong G, et al (2020)

Characterization of Metagenome-Assembled Genomes and Carbohydrate-Degrading Genes in the Gut Microbiota of Tibetan Pig.

Frontiers in microbiology, 11:595066.

Tibetan pig is an important domestic mammal, providing products of high nutritional value for millions of people living in the Qinghai-Tibet Plateau. The genomes of mammalian gut microbiota encode a large number of carbohydrate-active enzymes, which are essential for the digestion of complex polysaccharides through fermentation. However, the current understanding of microbial degradation of dietary carbohydrates in the Tibetan pig gut is limited. In this study, we produced approximately 145 gigabases of metagenomic sequence data for the fecal samples from 11 Tibetan pigs. De novo assembly and binning recovered 322 metagenome-assembled genomes taxonomically assigned to 11 bacterial phyla and two archaeal phyla. Of these genomes, 191 represented the uncultivated microbes derived from novel prokaryotic taxa. Twenty-three genomes were identified as metagenomic biomarkers that were significantly abundant in the gut ecosystem of Tibetan pigs compared to the other low-altitude relatives. Further, over 13,000 carbohydrate-degrading genes were identified, and these genes were more abundant in some of the genomes within the five principal phyla: Firmicutes, Bacteroidetes, Spirochaetota, Verrucomicrobiota, and Fibrobacterota. Particularly, three genomes representing the uncultivated Verrucomicrobiota encode the most abundant degradative enzymes in the fecal microbiota of Tibetan pigs. These findings should substantially increase the phylogenetic diversity of specific taxonomic clades in the microbial tree of life and provide an expanded repertoire of biomass-degrading genes for future application to microbial production of industrial enzymes.

RevDate: 2021-01-11

Huyben D, Roehe BK, Bekaert M, et al (2020)

Dietary Lipid:Protein Ratio and n-3 Long-Chain Polyunsaturated Fatty Acids Alters the Gut Microbiome of Atlantic Salmon Under Hypoxic and Normoxic Conditions.

Frontiers in microbiology, 11:589898.

Researchers have adjusted dietary lipid:protein ratios and n-3 long-chain polyunsaturated fatty acids (LC-PUFA) to optimize the growth performance of Atlantic salmon. However, dietary impacts on the gut microbiome are lacking, especially under varying environmental conditions. To examine this response, post-smolt salmon (184 ± 5 g) were fed diets with lipid:protein ratios considered low (180, 570 g/kg) and high (230, 460 g/kg) along with low and high levels of n-3 LC-PUFA (7 or 14 g/kg) while fish were reared under low and high levels of dissolved oxygen (6.7 or 8.0 mg/L). At day 0, 35 and 116, digesta in the distal intestine were collected and analyzed for viable counts and 16S ribosomal RNA (rRNA) genes (V4 region) using Illumina MiSeq. The reduction in oxygen had negligible effects, except on viable plate counts of total bacteria and an initial effect on beta-diversity. In contrast, the high lipid (HL) diets had an increased alpha-diversity (e.g., Shannon and Chao-1) at day 0 and day 35 whereas high n-3 diets suppressed these indices at day 116. Generally, a reduction in alpha-diversity was observed over time and an interaction between lipid:protein ratio x n-3 was found. Between diets, beta-diversity and phyla abundance were similar as both Proteobacteria (44%) and Firmicutes (21%) dominated. However, at the genus level Aliivibrio, Streptococcus, Weissella, and Lactobacillus, were associated with low lipid (LL) diets while the high lipid diets were associated with less abundant bacteria, e.g., Chromohalobacter. At day 116, the relative abundance of the Tenericutes phylum increased 10-fold (36%). Fish fed the high lipid diet with high n-3 had reduced alpha-diversity, lowest abundance of lactic acid bacteria, and highest abundance of Mycoplasma, which may indicate a less healthy gut microbiome. Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) analysis revealed that saturated and unsaturated fatty acid biosynthesis pathways were several folds higher in fish fed the high lipid diet, possibly to compensate for the lack of dietary n-3. In summary, our results show that the viable plate counts, alpha-diversity, beta-diversity, and predictive function of gut bacteria in Atlantic salmon post-smolts are influenced by dietary lipid:protein ratio and n-3 LC-PUFA over several time points with little effect by dissolved oxygen.

RevDate: 2021-01-11

Figueroa-Gonzalez PA, Bornemann TLV, Adam PS, et al (2020)

Saccharibacteria as Organic Carbon Sinks in Hydrocarbon-Fueled Communities.

Frontiers in microbiology, 11:587782.

Organisms of the candidate phylum Saccharibacteria have frequently been detected as active members of hydrocarbon degrading communities, yet their actual role in hydrocarbon degradation remained unclear. Here, we analyzed three enrichment cultures of hydrocarbon-amended groundwater samples using genome-resolved metagenomics to unravel the metabolic potential of indigenous Saccharibacteria. Community profiling based on ribosomal proteins revealed high variation in the enrichment cultures suggesting little reproducibility although identical cultivation conditions were applied. Only 17.5 and 12.5% of the community members were shared between the three enrichment cultures based on ribosomal protein clustering and read mapping of reconstructed genomes, respectively. In one enrichment, two Saccharibacteria strains dominated the community with 16.6% in relative abundance and we were able to recover near-complete genomes for each of them. A detailed analysis of their limited metabolism revealed the capacity for peptide degradation, lactate fermentation from various hexoses, and suggests a scavenging lifestyle with external retrieval of molecular building blocks. In contrast to previous studies suggesting that Saccharibacteria are directly involved in hydrocarbon degradation, our analyses provide evidence that these organisms can be highly abundant scavengers acting rather as organic carbon sinks than hydrocarbon degraders in these communities.

RevDate: 2021-01-11

Song J, Li Q, Everaert N, et al (2020)

Dietary Inulin Supplementation Modulates Short-Chain Fatty Acid Levels and Cecum Microbiota Composition and Function in Chickens Infected With Salmonella.

Frontiers in microbiology, 11:584380.

The current study investigated the effects of inulin on the gut microbiota, microbiome functions, and short-chain fatty acids (SCFAs) levels in specific pathogen-free (SPF) chickens infected with Salmonella enteritidis (SE). SPF Arbor Acres chickens (n = 240, 1-day-old) were divided into four groups: a control group (CON) fed a basal diet without inulin supplementation or SE infection, and three groups fed a basal diet supplemented with inulin 0, 0.5, and 1% (SE, 0.5%InSE, 1%InSE, respectively) up to 28-days-old, followed by SE challenge at 28 days of age. Cecal SCFA contents and microbiome composition and function were analyzed at 1-day post-infection. The results showed that SE infection significantly decreased cecal butyrate concentrations compared with the CON group (p < 0.05), while inulin supplementation reversed these changes compared with the SE group (p < 0.05). Inulin supplementation at 1% significantly increased the abundances of Lactobacillus and Streptococcus, and significantly decreased the abundances of Subdoligranulum and Sellimonas compared with the SE group (p < 0.05). The functional profiles of microbial communities based on metagenomic sequencing analysis showed that SE infection significantly increased the abundances of pathways related to carbohydrate metabolism, amino acid metabolism, energy metabolism, metabolism of cofactors and vitamins, and glycan biosynthesis and metabolism (p < 0.05), and significantly decreased the abundances of pathways related to nucleotide metabolism, translation, and replication and repair compared with the CON group (p < 0.05), and these effects were reversed by inulin supplementation (0.5 and 1%) (p < 0.05). In conclusion, inulin modulated the dysbiosis induced by SE infection via affecting SCFA metabolism and microbial functional profiles.

RevDate: 2021-01-11

Chen M, Liu S, Imam KMSU, et al (2020)

The Effect of Xylooligosaccharide, Xylan, and Whole Wheat Bran on the Human Gut Bacteria.

Frontiers in microbiology, 11:568457.

Wheat bran is a cereal rich in dietary fibers that have high levels of ferulic acid, which has prebiotic effects on the intestinal microbiota and the host. Herein we explored the effect of xylooligosaccharide, xylan, and whole wheat bran on the human gut bacteria and screened for potential ferulic acid esterase genes. Using in vitro fermentation, we analyzed the air pressure, pH-value, and short-chain fatty acid levels. We also performed 16S rRNA gene and metagenomic sequencing. A Venn diagram analysis revealed that 80% of the core operational taxonomic units (OTUs) were shared among the samples, and most of the xylooligosaccharide treatment core OTUs (319/333 OTUs) were shared with the other two treatments' core OTUs. A significant difference analysis revealed that the relative abundance of Dorea, Bilophila, and Sulfurovum in wheat bran treatment was higher than that in xylan and xylooligosaccharide treatments. The clusters of orthologous groups of proteins functional composition of all samples was similar to the microbiota composition of the control. Using metagenomic sequencing, we revealed seven genes containing the conserved residues, Gly-X-Ser-X-Gly, and the catalytic triad, Ser-His-Asp, which are thus potential ferulic acid esterase genes. All the results indicate that xylan and/or xylooligosaccharide, the main dietary fibers in wheat bran, plays a major role in in vitro fermentation by the human gut microbiota.

RevDate: 2021-01-11

Zhao HJ, Luo X, Shi YC, et al (2020)

The Efficacy of Fecal Microbiota Transplantation for Children With Tourette Syndrome: A Preliminary Study.

Frontiers in psychiatry, 11:554441.

Therapies for Tourette syndrome (TS) are insufficient, and novel therapies are needed. Fecal microbiota transplantation (FMT) has been a potential therapy for several neurological diseases. Here, we report a preliminary study to investigate the effects of FMT on patients with TS. Five patients with TS received a single administration of FMT via endoscopy. Tic symptoms were assessed by Yale Global Tic Severity Scale-Total Tic Score (YGTSS-TTS) and adverse effects were recorded at week 8 following FMT. Lipopolysaccharide (LPS) levels and 14 cytokines levels were measured. The microbiota profile in feces were analyzed by shotgun metagenomics. Four patients (4/5) responded positively to FMT (YGTSS-TTS reduction rate >25%) at week 8 with high safety. The levels of LPS and cytokines varied after FMT. FMT shifted the composition of the gut microbiota in patients close to that of the donor and continuously changed the abundance of Bacteroides coprocola, Dialister succinatiphilus and Bacteroides vulgatus. The restoration of B.coprocola was correlated with the improvement in tic symptoms (Spearman R = -0.900, P = 0.037). In conclusion, FMT was indicated a potential effective and safe alternative for patients with TS. However, larger clinical trials are needed to confirm the influence of microbiota in TS. Trial Registration: chictr.org.cn Identifier: ChiCTR-IIR-17011871, URL: http://www.chictr.org.cn/showproj.aspx?proj=19941.

RevDate: 2021-01-11

Ramadurai S, U Balasundaram (2020)

Rhizomicrobiomics of Caesalpinia bonducella, a wonder plant for PCOS treatment.

Physiology and molecular biology of plants : an international journal of functional plant biology, 26(12):2453-2463.

Plant and rhizobacterial interactions contribute partly to a plant's medicinal properties and are well studied through metagenomics. In this study, 16S rDNA, 18S rDNA, and ITS meta-sequencing were performed using the genomic DNA obtained from the rhizosphere of Caesalpinia bonducella-a medicinal shrub widely used to treat polycystic ovary syndrome (PCOS). Of the 665 Operational Taxonomic Units (OTUs) obtained from 16S rDNA sequencing, 23.9% comprised of microbes that increase the therapeutic value of plants (Bacillus, Paenibacillus), 6.4% belonged to stress and drought tolerant microbes (Pseudomonas, Rhizobium, Serratia), 8% belonged to plant-growth promoting rhizobacteria-predominantly Proteobacteria, and Firmicutes and the remaining were the microbes performing various other functions. Alpha diversity indexing by GAIA-metagenomics tool revealed the presence of a highly diverse group of microbes in the rhizosphere of C. bonducella; Chao.1 index (665), Shannon Weiner index (3.53), Simpson index (0.83) and Fisher index (106.13). The highly diverse microbes lingering around the roots of C. bonducella could possibly be due to a strong symbiotic association with the plant; root exudates nourish the microbes and the microbes in turn enrich the medicinal value of the plant.

RevDate: 2021-01-11
CmpDate: 2021-01-11

Forsman ZH, Ritson-Williams R, Tisthammer KH, et al (2020)

Host-symbiont coevolution, cryptic structure, and bleaching susceptibility, in a coral species complex (Scleractinia; Poritidae).

Scientific reports, 10(1):16995.

The 'species' is a key concept for conservation and evolutionary biology, yet the lines between population and species-level variation are often blurred, especially for corals. The 'Porites lobata species complex' consists of branching and mounding corals that form reefs across the Pacific. We used reduced representation meta-genomic sequencing to examine genetic relationships within this species complex and to identify candidate loci associated with colony morphology, cryptic genetic structure, and apparent bleaching susceptibility. We compared existing Porites data with bleached and unbleached colonies of the branching coral P. compressa collected in Kāne'ohe Bay Hawai'i during the 2015 coral bleaching event. Loci that mapped to coral, symbiont, and microbial references revealed genetic structure consistent with recent host-symbiont co-evolution. Cryptic genetic clades were resolved that previous work has associated with distance from shore, but no genetic structure was associated with bleaching. We identified many candidate loci associated with morphospecies, including candidate host and symbiont loci with fixed differences between branching and mounding corals. We also found many loci associated with cryptic genetic structure, yet relatively few loci associated with bleaching. Recent host-symbiont co-evolution and rapid diversification suggests that variation and therefore the capacity of these corals to adapt may be underappreciated.

RevDate: 2021-01-11
CmpDate: 2021-01-11

Soriano-Lerma A, Pérez-Carrasco V, Sánchez-Marañón M, et al (2020)

Influence of 16S rRNA target region on the outcome of microbiome studies in soil and saliva samples.

Scientific reports, 10(1):13637.

Next generation sequencing methods are widely used in evaluating the structure and functioning of microbial communities, especially those centered on 16S rRNA subunit. Since Illumina Miseq, the most used sequencing platform, does not allow the full sequencing of 16S rRNA gene, this study aims to evaluate whether the choice of different target regions might affect the outcome of microbiome studies regarding soil and saliva samples. V1V3, V3V4, V4V5 and V6V8 domains were studied, finding that while some regions showed differences in the detection of certain bacterial taxa and in the calculation of alpha diversity, especially in soil samples, the overall effect did not compromise the differentiation of any sample type in terms of taxonomic analysis at the genus level. 16S rRNA target regions did affect the detection of specific bacteria related to soil quality and development, and microbial genera used as health biomarkers in saliva. V1V3 region showed the closest similarity to internal sequencing control mock community B, suggesting it might be the most preferable choice regarding data reliability.

RevDate: 2021-01-11
CmpDate: 2021-01-11

Duan C, Kuang L, Xiang X, et al (2020)

Activated Drp1-mediated mitochondrial ROS influence the gut microbiome and intestinal barrier after hemorrhagic shock.

Aging, 12(2):1397-1416.

A role of the mitochondrial dynamin-related protein (Drp1) on gut microbiome composition and intestinal barrier function after hemorrhagic shock has not been identified previously and thus addressed in this study. Here, we used a combination of 16S rRNA gene sequencing and mass spectrometry-based metabolomics profiling in WT and Drp1 KO mouse models to examine the functional impact of activated Drp1 on the gut microbiome as well as mitochondrial metabolic regulation after hemorrhagic shock. Our data showed that changes in mitochondrial Drp1 activity participated in the regulation of intestinal barrier function after hemorrhagic shock. Activated Drp1 significantly perturbed gut microbiome composition in the Bacteroidetes phylum. The abundance of short-chain fatty acid (SCFA) producing microbes, such as Bacteroides, Butyricimonas and Odoribacter, was markedly decreased in mice after shock, and was inversely correlated with both the distribution of the tight junction protein ZO1 and intestinal permeability. Together, these data suggest that Drp1 activation perturbs the gut microbiome community and SCFA production in a ROS-specific manner and thereby substantially disturbs tight junctions and intestinal barrier function after hemorrhagic shock. Our findings provide novel insights for targeting Drp1-mediated mitochondrial function as well as the microbiome in the treatment of intestinal barrier dysfunction after shock.

RevDate: 2021-01-11
CmpDate: 2021-01-11

Wang QJ, Shen YE, Wang X, et al (2020)

Concomitant memantine and Lactobacillus plantarum treatment attenuates cognitive impairments in APP/PS1 mice.

Aging, 12(1):628-649.

Trimethylamine-N-oxide (TMAO) is a gut microbial metabolite that promotes Alzheimer's disease (AD) progression. Given that probiotics can alleviate AD symptoms by inhibiting the synthesis of TMAO, here we investigated the correlation between TMAO and cognitive deterioration by measuring TMAO levels in the plasma of choline-treated APP/PS1 mice (an AD mouse model) with and without probiotic treatments. We found that declines in L.plantarum in the gut were associated with cognitive impairment. Moreover, 12-weeks of treatment with memantine plus L. plantarum ameliorated cognitive deterioration, decreased Αβ levels in the hippocampus, and protected neuronal integrity and plasticity. These effects were accompanied by reductions in TMAO synthesis and neuroinflammation. These experiments demonstrate that L. plantarum augments the beneficial therapeutic effects of memantine treatment in APP/PS1 mice by remodeling the intestinal microbiota, inhibiting the synthesis of TMAO, and reducing clusterin levels. Our results thus highlight intestinal microbiota as a potential therapeutic target to decrease the risk of AD.

RevDate: 2021-01-11
CmpDate: 2021-01-11

Diling C, Longkai Q, Yinrui G, et al (2020)

CircNF1-419 improves the gut microbiome structure and function in AD-like mice.

Aging, 12(1):260-287.

Our pre-experiments found that the brain circRNA sequence profiles and gut microbiota in AD-like mice were changed, as circNF1-419 could enhance autophagy to ameliorate senile dementia in AD-like mice, so we conclude that there might some connections between circRNA and gut microbiome. Therefore, we use the over-expressed circNF1-419 adeno-associated virus (AAV) animal system with the aim of identifying possible connections. Our results showed that over-expression of circNF1-419 in brain not only influenced the cholinergic system of brain, but also changed the gut microbiota composition as the Candidatus Arthromitus, Lachnospiraceae FCS020 group, Lachnospiraceae UCG-006, and [Eubacterium] xylanophilum group, and the intestinal homeostasis and physiology, and even the gut microbiota trajectory in new born mice. These findings demonstrate a link between circRNA and gut microbiome, enlarge the 'microbiome- transcriptome' linkage library and provide more information on gut-brain axis.

RevDate: 2021-01-10

Piñol J (2021)

Genotype by Sequencing: an alternative new method to amplicon metabarcoding and shotgun metagenomics for the assessment of eukaryote biodiversity.

The use of high-throughput DNA-sequencing (HTS) has revolutionised the assessment of biodiversity in plant and animal communities. There are two main approaches to estimate the identity and the relative species abundance (RSA) in complex mixtures using HTS: amplicon metabarcoding and shotgun metagenomics. While amplicon metabarcoding targets one or a few genomic regions, shotgun metagenomics randomly explores the genome of the species. In this issue of Molecular Ecology Resources, Wagemaker et al. (2021) present a new method, multi-species Genotyping by Sequencing (msGBS), as an alternative middle ground between metabarcoding and metagenomics. They apply the technique to mixtures of plant roots and report the remarkable capacity of msGBS to estimate the RSA. If validated in other labs and biological communities, msGBS might become a third method to explore the biodiversity of biological communities, especially of plants, where current techniques are struggling to get sufficient taxonomic resolution.

RevDate: 2021-01-10

Pérez-Cataluña A, Cuevas-Ferrando E, Randazzo W, et al (2020)

Bias of library preparation for virome characterization in untreated and treated wastewaters.

The Science of the total environment, 767:144589 pii:S0048-9697(20)38120-1 [Epub ahead of print].

The use of metagenomics for virome characterization and its implementation for wastewater analyses, including wastewater-based epidemiology, has increased in the last years. However, the lack of standardized methods can led to highly different results. The aim of this work was to analyze virome profiles in upstream and downstream wastewater samples collected from four wastewater treatment plants (WWTPs) using two different library preparation kits. Viral particles were enriched from wastewater concentrates using a filtration and nuclease digestion procedure prior to total nucleic acid (NA) extraction. Sequencing was performed using the ScriptSeq v2 RNA-Seq (LS) and the NEBNext Ultra II RNA (NB) library preparation kits. Cleaned reads and contigs were annotated using a curated in-house database composed by reads assigned to viruses at NCBI. Significant differences in viral families and in the ratio of detection were shown between the two library kits used. The use of LS library showed Virgaviridae, Microviridae and Siphoviridae as the most abundant families; while Ackermannviridae and Helleviridae were highly represented within the NB library. Additionally, the two sequencing libraries produced outcomes that differed in the detection of viral indicators. These results highlighted the importance of library selection for studying viruses in untreated and treated wastewater. Our results underline the need for further studies to elucidate the influence of sequencing procedures in virome profiles in wastewater matrices in order to improve the knowledge of the virome in the water environment.

RevDate: 2021-01-10

Tan SM, Ismail MH, B Cao (2021)

Biodiversity of Magnetotactic Bacteria in the tropical marine environment of Singapore revealed by metagenomic analysis.

Environmental research pii:S0013-9351(21)00008-6 [Epub ahead of print].

Most studies on the diversity of magnetotactic bacteria (MTB) have been conducted on samples obtained from the Northern or the Southern hemispheres. The diversity of MTB in tropical Asia near the geo-equator, with a close-to-zero geomagnetic inclination, weak magnetic field and constantly high seawater temperature has never been explored. This study aims to decipher the diversity of MTB in the marine environment of Singapore through shotgun metagenomics. Although MTB has been acknowledged to be ubiquitous in aquatic environments, we did not observe magnetotactic behaviour in the samples. However, we detected the presence and determined the diversity of MTB through bioinformatic analyses. Metagenomic analysis suggested majority of the MTB in the seafloor sediments represents novel MTB taxa that cannot be classified at the species level. The relative abundance of MTB (∼0.2-1.69%) in the samples collected from the marine environment of Singapore was found to be substantially lower than studies for other regions. In contrast to other studies, the genera Magnetovibrio and Desulfamplus, but not Magnetococcus, were the dominant MTB. Additionally, we recovered 3 MTB genomic bins that are unclassified at the species level, with Magnetovibrio blakemorei being the closest-associated genome. All the recovered genomic bins contain homologs of at least 5 of the 7 mam genes but lack homologs for mamI, a membrane protein suggested to take part in the magenetosome invagination. This study fills in the knowledge gap of MTB biodiversity in the tropical marine environment near the geo-equator. Our findings will facilitate future research efforts aiming to unravel the ecological roles of MTB in the tropical marine environments as well as to bioprospecting novel MTB that have been adapted to tropical marine environments for biotechnological applications.

RevDate: 2021-01-10

Gardiner LJ, Haiminen N, Utro F, et al (2021)

Re-purposing software for functional characterization of the microbiome.

Microbiome, 9(1):4.

BACKGROUND: Widespread bioinformatic resource development generates a constantly evolving and abundant landscape of workflows and software. For analysis of the microbiome, workflows typically begin with taxonomic classification of the microorganisms that are present in a given environment. Additional investigation is then required to uncover the functionality of the microbial community, in order to characterize its currently or potentially active biological processes. Such functional analysis of metagenomic data can be computationally demanding for high-throughput sequencing experiments. Instead, we can directly compare sequencing reads to a functionally annotated database. However, since reads frequently match multiple sequences equally well, analyses benefit from a hierarchical annotation tree, e.g. for taxonomic classification where reads are assigned to the lowest taxonomic unit.

RESULTS: To facilitate functional microbiome analysis, we re-purpose well-known taxonomic classification tools to allow us to perform direct functional sequencing read classification with the added benefit of a functional hierarchy. To enable this, we develop and present a tree-shaped functional hierarchy representing the molecular function subset of the Gene Ontology annotation structure. We use this functional hierarchy to replace the standard phylogenetic taxonomy used by the classification tools and assign query sequences accurately to the lowest possible molecular function in the tree. We demonstrate this with simulated and experimental datasets, where we reveal new biological insights.

CONCLUSIONS: We demonstrate that improved functional classification of metagenomic sequencing reads is possible by re-purposing a range of taxonomic classification tools that are already well-established, in conjunction with either protein or nucleotide reference databases. We leverage the advances in speed, accuracy and efficiency that have been made for taxonomic classification and translate these benefits for the rapid functional classification of microbiomes. While we focus on a specific set of commonly used methods, the functional annotation approach has broad applicability across other sequence classification tools. We hope that re-purposing becomes a routine consideration during bioinformatic resource development. Video abstract.

RevDate: 2021-01-10

Tingley JP, Low KE, Xing X, et al (2021)

Combined whole cell wall analysis and streamlined in silico carbohydrate-active enzyme discovery to improve biocatalytic conversion of agricultural crop residues.

Biotechnology for biofuels, 14(1):16.

The production of biofuels as an efficient source of renewable energy has received considerable attention due to increasing energy demands and regulatory incentives to reduce greenhouse gas emissions. Second-generation biofuel feedstocks, including agricultural crop residues generated on-farm during annual harvests, are abundant, inexpensive, and sustainable. Unlike first-generation feedstocks, which are enriched in easily fermentable carbohydrates, crop residue cell walls are highly resistant to saccharification, fermentation, and valorization. Crop residues contain recalcitrant polysaccharides, including cellulose, hemicelluloses, pectins, and lignin and lignin-carbohydrate complexes. In addition, their cell walls can vary in linkage structure and monosaccharide composition between plant sources. Characterization of total cell wall structure, including high-resolution analyses of saccharide composition, linkage, and complex structures using chromatography-based methods, nuclear magnetic resonance, -omics, and antibody glycome profiling, provides critical insight into the fine chemistry of feedstock cell walls. Furthermore, improving both the catalytic potential of microbial communities that populate biodigester reactors and the efficiency of pre-treatments used in bioethanol production may improve bioconversion rates and yields. Toward this end, knowledge and characterization of carbohydrate-active enzymes (CAZymes) involved in dynamic biomass deconstruction is pivotal. Here we overview the use of common "-omics"-based methods for the study of lignocellulose-metabolizing communities and microorganisms, as well as methods for annotation and discovery of CAZymes, and accurate prediction of CAZyme function. Emerging approaches for analysis of large datasets, including metagenome-assembled genomes, are also discussed. Using complementary glycomic and meta-omic methods to characterize agricultural residues and the microbial communities that digest them provides promising streams of research to maximize value and energy extraction from crop waste streams.

RevDate: 2021-01-09

Sun Y, Cao N, Duan C, et al (2020)

Selection of antibiotic resistance genes on biodegradable and non-biodegradable microplastics.

Journal of hazardous materials, 409:124979 pii:S0304-3894(20)32970-8 [Epub ahead of print].

Growing evidence have demonstrated that microplastics in the marine ecosystem can provide novel substrates for biofilm formation, potentially facilitating the spread of antibiotic resistance. However, the occurrence of antibiotic resistance genes (ARGs) in the biofilm on microplastics has not been fully explored. This study used the metagenomic data of biodegradable and non-biodegradable microplastics staged at a coastal lagoon in the northern Gulf of Mexico to profile the ARGs and their bacterial hosts. The abundance and Shannon diversity of ARGs on biodegradable poly hydroxy alkanoate (PHA) and non-biodegradable polyethylene terephthalate (PET) have no significant differences. Nevertheless, the abundance of multidrug resistance genes on PET (3.05 copies per 16S rRNA) was statistically higher than that on PHA (2.05). Beta diversity showed that the overall pattern of resistome on PHA was significantly distinct with that on PET. Procrustes analysis suggested a good-fit correlation between ARG profiles and bacterial community composition. The host-tracking analysis identified that Pseudomonas was always the major host for glycopeptide and multidrug resistance genes in PET and PHA biofilms, whereas the primary host for macrolide-lincosamide-streptogramin (MLS) changed to Desulfovibrio on PET. This study provided the first metagenomic insights into the ARGs and their hosts on biodegradable and non-biodegradable microplastics, suggesting that both two types of plastics harbor ARGs with preferences.

RevDate: 2021-01-09

Chen YH, Xue F, Yu SF, et al (2020)

Gut microbiota dysbiosis in depressed women: The association of symptom severity and microbiota function.

Journal of affective disorders, 282:391-400 pii:S0165-0327(20)33233-X [Epub ahead of print].

BACKGROUND: The association between abnormal gut microbiome composition and depression is well established. However, the composition and functional capacity of the gut microbiota regarding depressed women has been poorly addressed.

METHODS: Stool samples from 62 female patients with major depressive disorder (MDD) and 46 healthy controls (Con) were analyzed by 16S rRNA gene sequencing; Twenty fecal samples from the patient group and 21 fecal samples from the Con group were further analyzed by shotgun metagenomic sequencing. Psychiatric symptoms and psychological, social, and professional functioning was also assessed.

RESULTS: Phylum Bacteroidetes, proteobaeteria, and Fusobacteria were greatly enriched in patients with MDD, while the Firmicutes and Actinobacteria phyla were consistently higher in Con. Notably, 18 microbial markers were identified on a random forest model and achieve an area under the curve of 0.92 between patients with MDD and the Con group. Forty-five species and their associated function were identified with statistically significant differences between patients with MDD and the Con group.

LIMITATIONS: The number of recruited samples, especially samples enrolled for shotgun metagenomic sequencing was relatively small, and the stool samples were collected only at baseline, making it difficult to establish a causal association between changes in gut microbiota compositions and disease remission.

CONCLUSIONS: This study characterizes the gut microbiota and their related function in female MDD. The gut microbiota-based biomarkers may be helpful in diagnosis and the altered gut microbial metabolites may contribute to the pathogenesis of MDD in women, representing potential microbial targets.

RevDate: 2021-01-09

Wang C, Hu R, Strong PJ, et al (2020)

Prevalence of antibiotic resistance genes and bacterial pathogens along the soil-mangrove root continuum.

Journal of hazardous materials, 408:124985 pii:S0304-3894(20)32976-9 [Epub ahead of print].

Plants roots are colonised by soil bacteria that are known to be the reservoir of antibiotic resistance genes (ARGs). ARGs can transfer between these microorganisms and pathogens, but to what extent these ARGs and pathogens disseminate from soil into plant is poorly understood. Here, we examined a high-resolution resistome profile along the soil-root continuum of mangrove saplings using amplicon and metagenomic sequencing. Data revealed that 91.4% of total ARGs were shared across four root-associated compartments (endosphere, episphere, rhizosphere and unplanted soil). Rather than compartment-selective dynamics of microbiota, the resistome was disseminated in a continuous fashion along the soil-root continuum. Such dissemination was independent of underlying root-associated bacterial and fungal microbiota, but might be facilitated by a multiplicity of mobile genetic elements. As the multiple-drug resistant pathogens, Vibrio vulnificus, pathogenic Escherichia coli and Klebsiella pneumoniae consistently predominated across four compartments, indicating the potential dissemination of antibiotic pathogens along the soil-root continuum. Through deciphering the profile and dynamics of the root-associated resistome and pathogens, our study identified the soil-root continuum as an interconnected sink through which certain ARGs and pathogens can flow from soil into the plant.

RevDate: 2021-01-09

Liang C, Wei D, Zhang S, et al (2021)

Removal of antibiotic resistance genes from swine wastewater by membrane filtration treatment.

Ecotoxicology and environmental safety, 210:111885 pii:S0147-6513(20)31721-8 [Epub ahead of print].

Antibiotic resistance genes (ARGs) have attracted extensive attention as an emerging environmental contaminant potentially threatening humans. One of the main emission sources of ARGs is swine wastewater. In this study, integrated membrane filtration including ultrafiltration and two-stage reverse osmosis was conducted for swine wastewater treatment. The abundances of 16 target ARGs, which accounted for 72.64% of the total ARGs in swine wastewater according to metagenomic sequencing, were quantified by quantitative real-time PCR (qPCR) during each stage of the membrane filtration process. The results showed that integrated membrane filtration could reduce more than 99.0% of conventional pollutants and 99.79% of ARGs (from 3.02 × 108 copy numbers/mL to 6.45 × 105 copy numbers/mL). Principal component analysis (PCA) indicated that the removal efficiency of ARGs subtype by membrane filtration did not depend on ARGs type. However, strong correlations were found between ARGs and the wastewater quality indicators TP, SS and EC according to Cooccurrence patterns, indicating that ARG removal was closely associated with insoluble solid particles and soluble ions in swine wastewater. These results showed that membrane filtration could not only remove conventional pollutants such as nitrogen and phosphorus but also reduce the emerging pollutant of ARGs and decrease the risk of ARGs flowing into natural water.

RevDate: 2021-01-09

Verma S, Meghwanshi GK, R Kumar (2021)

Current perspectives for microbial lipases from extremophiles and metagenomics.

Biochimie pii:S0300-9084(21)00002-X [Epub ahead of print].

Microbial lipases are most broadly used biocatalysts for environmental and industrial applications. Lipases catalyze the hydrolysis and synthesis of long acyl chain esters and have a characteristic folding pattern of α/β hydrolase with highly conserved catalytic triad (Serine, Aspartic/Glutamic acid and Histidine). Mesophilic lipases (optimal activity in neutral pH range, mesophilic temperature range, atmospheric pressure, normal salinity, non-radio-resistant, and instability in organic solvents) have been in use for many industrial biotransformation reactions. However, lipases from extremophiles can be used to design biotransformation reactions with higher yields, less byproducts or useful side products and have been predicted to catalyze those reactions also, which otherwise are not possible with the mesophilic lipases. The extremophile lipase perform activity at extremes of temperature, pH, salinity, and pressure which can be screened from metagenome and de novo lipase design using computational approaches. Despite structural similarity, they exhibit great diversity at the sequence level. This diversity is broader when lipases from the bacterial, archaeal, plant, and animal domains/kingdoms are compared. Furthermore, a great diversity of novel lipases exists and can be discovered from the analysis of the dark matter - the unexplored nucleotide/metagenomic databases. This review is an update on extremophilic microbial lipases, their diversity, structure, and classification. An overview on novel lipases which have been detected through analysis of the genomic dark matter (metagenome) has also been presented.

RevDate: 2021-01-09

Koeninger L, Osbelt L, Berscheid A, et al (2021)

Curbing gastrointestinal infections by defensin fragment modifications without harming commensal microbiota.

Communications biology, 4(1):47.

The occurrence and spread of multidrug-resistant pathogens, especially bacteria from the ESKAPE panel, increases the risk to succumb to untreatable infections. We developed a novel antimicrobial peptide, Pam-3, with antibacterial and antibiofilm properties to counter this threat. The peptide is based on an eight-amino acid carboxyl-terminal fragment of human β-defensin 1. Pam-3 exhibited prominent antimicrobial activity against multidrug-resistant ESKAPE pathogens and additionally eradicated already established biofilms in vitro, primarily by disrupting membrane integrity of its target cell. Importantly, prolonged exposure did not result in drug-resistance to Pam-3. In mouse models, Pam-3 selectively reduced acute intestinal Salmonella and established Citrobacter infections, without compromising the core microbiota, hence displaying an added benefit to traditional broad-spectrum antibiotics. In conclusion, our data support the development of defensin-derived antimicrobial agents as a novel approach to fight multidrug-resistant bacteria, where Pam-3 appears as a particularly promising microbiota-preserving candidate.

RevDate: 2021-01-09

Wongsaroj L, Chanabun R, Tunsakul N, et al (2021)

First reported quantitative microbiota in different livestock manures used as organic fertilizers in the Northeast of Thailand.

Scientific reports, 11(1):102.

Northeastern Thailand relies on agriculture as a major economic activity, and has used high levels of agrochemicals due to low facility, and salty sandy soil. To support soil recovery and sustainable agriculture, local farmers have used organic fertilizers from farmed animal feces. However, knowledge about these animal fecal manures remains minimal restricting their optimal use. Specifically, while bacteria are important for soil and plant growth, an abundance and a diversity of bacterial composition in these animal fecal manures have not been reported to allow selection and adjustment for a more effective organic fertilizer. This study thereby utilized metagenomics combined with 16S rRNA gene quantitative PCR (qPCR) and sequencing to analyze quantitative microbiota profiles in association with nutrients (N, P, K), organic matters, and the other physiochemical properties, of the commonly used earthworm manure and other manures from livestock animals (including breed and feeding diet variations) in the region. Unlike the other manures, the earthworm manure demonstrated more favorable nutrient profiles and physiochemical properties for forming fertile soil. Despite low total microbial biomass, the microbiota were enriched with maximal OTUs and Chao richness, and no plant pathogenic bacteria were found based on the VFDB database. The microbial metabolic potentials supported functions to promote crop growth, such as C, N and P cyclings, xenobiotic degradation, and synthesis of bioactive compounds. Pearson's correlation analyses indicated that the quantitative microbiota of the earthworm manure were clustered in the same direction as N, and conductivity, salinity, and water content were essential to control the microbiota of animal manures.

RevDate: 2021-01-09

Behary J, Amorim N, Jiang XT, et al (2021)

Gut microbiota impact on the peripheral immune response in non-alcoholic fatty liver disease related hepatocellular carcinoma.

Nature communications, 12(1):187.

The gut microbiota is reported to modulate the immune response in hepatocellular carcinoma (HCC). Here, we employ metagenomic and metabolomic studies to characterise gut microbiota in patients with non-alcoholic fatty liver disease (NAFLD) related cirrhosis, with or without HCC, and evaluate its effect on the peripheral immune response in an ex vivo model. We find that dysbiosis characterises the microbiota of patients with NAFLD-cirrhosis, with compositional and functional shifts occurring with HCC development. Gene function of the microbiota in NAFLD-HCC supports short chain fatty acid production, and this is confirmed by metabolomic studies. Ex vivo studies show that bacterial extracts from the NAFLD-HCC microbiota, but not from the control groups, elicit a T cell immunosuppressive phenotype, characterised by expansion of regulatory T cells and attenuation of CD8 + T cells. Our study suggest that the gut microbiota in NAFLD-HCC is characterised by a distinctive microbiome/metabolomic profile, and can modulate the peripheral immune response.

RevDate: 2021-01-09

Bellassi P, Rocchetti G, Nocetti M, et al (2021)

A Combined Metabolomic and Metagenomic Approach to Discriminate Raw Milk for the Production of Hard Cheese.

Foods (Basel, Switzerland), 10(1): pii:foods10010109.

The chemical composition of milk can be significantly affected by different factors across the dairy supply chain, including primary production practices. Among the latter, the feeding system could drive the nutritional value and technological properties of milk and dairy products. Therefore, in this work, a combined foodomics approach based on both untargeted metabolomics and metagenomics was used to shed light onto the impact of feeding systems (i.e., hay vs. a mixed ration based on hay and fresh forage) on the chemical profile of raw milk for the production of hard cheese. In particular, ultra-high-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UHPLC-QTOF) was used to investigate the chemical profile of raw milk (n = 46) collected from dairy herds located in the Po River Valley (Italy) and considering different feeding systems. Overall, a total of 3320 molecular features were putatively annotated across samples, corresponding to 734 unique compound structures, with significant differences (p < 0.05) between the two feeding regimens under investigation. Additionally, supervised multivariate statistics following metabolomics-based analysis allowed us to clearly discriminate raw milk samples according to the feeding systems, also extrapolating the most discriminant metabolites. Interestingly, 10 compounds were able to strongly explain the differences as imposed by the addition of forage in the cows' diet, being mainly glycerophospholipids (i.e., lysophosphatidylethanolamines, lysophosphatidylcholines, and phosphatidylcholines), followed by 5-(3',4'-Dihydroxyphenyl)-gamma-valerolactone-4'-O-glucuronide, 5a-androstan-3a,17b-diol disulfuric acid, and N-stearoyl glycine. The markers identified included both feed-derived (such as phenolic metabolites) and animal-derived compounds (such as lipids and derivatives). Finally, although characterized by a lower prediction ability, the metagenomic profile was found to be significantly correlated to some milk metabolites, with Staphylococcaceae, Pseudomonadaceae, and Dermabacteraceae establishing a higher number of significant correlations with the discriminant metabolites. Therefore, taken together, our preliminary results provide a comprehensive foodomic picture of raw milk samples from different feeding regimens, thus supporting further ad hoc studies investigating the metabolomic and metagenomic changes of milk in all processing conditions.

RevDate: 2021-01-09

Govil T, Paste M, Samanta D, et al (2021)

Metagenomics and Culture Dependent Insights into the Distribution of Firmicutes across Two Different Sample Types Located in the Black Hills Region of South Dakota, USA.

Microorganisms, 9(1): pii:microorganisms9010113.

Firmicutes is almost a ubiquitous phylum. Several genera of this group, for instance, Geobacillus, are recognized for decomposing plant organic matter and for producing thermostable ligninolytic enzymes. Amplicon sequencing was used in this study to determine the prevalence and genetic diversity of the Firmicutes in two distinctly related environmental samples-South Dakota Landfill Compost (SDLC, 60 °C), and Sanford Underground Research Facility sediments (SURF, 45 °C). Although distinct microbial community compositions were observed, there was a dominance of Firmicutes in both the SDLC and SURF samples, followed by Proteobacteria. The abundant classes of bacteria in the SDLC site, within the phylum Firmicutes, were Bacilli (83.2%), and Clostridia (2.9%). In comparison, the sample from the SURF mine was dominated by the Clostridia (45.8%) and then Bacilli (20.1%). Within the class Bacilli, the SDLC sample had more diversity (a total of 11 genera with more than 1% operational taxonomic unit, OTU). On the other hand, SURF samples had just three genera, about 1% of the total population: Bacilli, Paenibacillus, and Solibacillus. With specific regard to Geobacillus, it was found to be present at a level of 0.07% and 2.5% in SURF and SDLC, respectively. Subsequently, culture isolations of endospore-forming Firmicutes members from these samples led to the isolation of a total of 117 isolates. According to colony morphologies, and identification based upon 16S rRNA and gyrB gene sequence analysis, we obtained 58 taxonomically distinct strains. Depending on the similarity indexes, a gyrB sequence comparison appeared more useful than 16S rRNA sequence analysis for inferring intra- and some intergeneric relationships between the isolates.

RevDate: 2021-01-09

Zhang Z, Liu D, Wang D, et al (2021)

Library Preparation Based on Transposase Assisted RNA/DNA Hybrid Co-Tagmentation for Next-Generation Sequencing of Human Noroviruses.

Viruses, 13(1): pii:v13010065.

Human noroviruses (HuNoVs) are one of the leading causes of foodborne illnesses globally. The viral genome is the most essential information for viral source tracing and viral transmission pattern monitoring. However, whole genome sequencing of HuNoVs is still challenging due to the sequence heterogeneity among different genotypes and low titer in samples. To address this need, in this study, the Transposase assisted RNA/DNA hybrid Co-tagmentation (TRACE-seq) method was established for next generation sequencing library preparation of HuNoVs. Our data demonstrated that almost the whole HuNoVs genome (>7 kb) could be obtained from all of the 11 clinical samples tested. Twelve genotypes including GI.3, GI.4, GI.5, GI.8, GII.2, GII.3, GII.4, GII.6, GII.12, GII.13, GII.14, and GII.21 were involved. Compared with the traditional method for viral metagenomics library preparation, optimized TRACE-seq greatly reduced the interference from the host's and bacterial RNAs. In addition, viral genome sequences can be assembled by using less raw data with sufficient depth along the whole genome. Therefore, for the high versatility and reliability, this method is promising for whole viral genome attainment. It is particularly applicable for the viruses with a low titer that are mixed with a complicated host background and are unable to be cultured in vitro, like the HuNoVs utilized in this study.

RevDate: 2021-01-09

Tao LY, Gong JS, Su C, et al (2018)

Mining and Expression of a Metagenome-Derived Keratinase Responsible for Biosynthesis of Silver Nanoparticles.

ACS biomaterials science & engineering, 4(4):1307-1315.

A keratinase gene kerBv was mined from soil metagenomes. The open reading frame consisted of 1149 bp and potentially encoded a protein of 382 amino acid residues. It shared the same active site with several reported typical keratinases via analysis of the amino acid sequence. The keratinase was successfully expressed in B. subtilis WB600 with pMA5 expression vector. The maximum activity of 164.8 U/mL in the fermentation supernatant was observed after incubating for 30 h in Terrifc Broth (TB) medium. The keratinase exhibited outstanding resistance to metal ions and was surfactant-stable. Additionally, the enzyme displayed broad substrate specificity especially toward insoluble substrate feather meal because of its disulfide bond-reducing activity. Furthermore, the reducing power of the recombinant keratinase was investigated. It showed that the protein exhibited a relatively high reducing power, which was subsequently used in the biosynthesis of silver nanoparticles (AgNPs). The biosynthesized AgNPs were characterized by ultraviolet-visible (UV-vis) spectroscopy, dynamic light scattering (DLS), transmission electron microscope (TEM), as well as Fourier transform infrared spectroscopy (FTIR) and displayed obvious antibacterial activities toward Escherichia coli.

RevDate: 2021-01-08

Yao G, Zhang W, Yang M, et al (2021)

MicroPhenoDB Associates Metagenomic Data with Pathogenic Microbes, Microbial Core Genes, and Human Disease Phenotypes.

Genomics, proteomics & bioinformatics pii:S1672-0229(20)30169-8 [Epub ahead of print].

Microbes play important roles in human health and disease. The interaction between microbes and hosts is a reciprocal relationship, which remains largely under-explored. Current computational resources lack manually and consistently curated data to connect metagenomic data to pathogenic microbes, microbial core genes, and disease phenotypes. We developed the MicroPhenoDB database by manually curating and consistently integrating microbe-disease association data. MicroPhenoDB provides 5677 non-redundant associations between 1781 microbes and 542 human disease phenotypes across more than 22 human body sites. MicroPhenoDB also provides 696,934 relationships between 27,277 unique clade-specific core genes and 685 microbes. Disease phenotypes are classified and described using the Experimental Factor Ontology (EFO). A refined score model was developed to prioritize the associations based on evidential metrics. The sequence search option in MicroPhenoDB enables rapid identification of existing pathogenic microbes in samples without running the usual metagenomic data processing and assembly. MicroPhenoDB offers data browsing, searching, and visualization through user-friendly web interfaces and web service application programming interfaces. MicroPhenoDB is the first database platform to detail the relationships between pathogenic microbes, core genes, and disease phenotypes. It will accelerate metagenomic data analysis and assist studies in decoding microbes related to human diseases. MicroPhenoDB is available through http://www.liwzlab.cn/microphenodb and http://lilab2.sysu.edu.cn/microphenodb.

RevDate: 2021-01-08

Scharf ME, BF Peterson (2021)

A Century of Synergy in Termite Symbiosis Research: Linking the Past with New Genomic Insights.

Annual review of entomology, 66:23-43.

Termites have long been studied for their symbiotic associations with gut microbes. In the late nineteenth century, this relationship was poorly understood and captured the interest of parasitologists such as Joseph Leidy; this research led to that of twentieth-century biologists and entomologists including Cleveland, Hungate, Trager, and Lüscher. Early insights came via microscopy, organismal, and defaunation studies, which led to descriptions of microbes present, descriptions of the roles of symbionts in lignocellulose digestion, and early insights into energy gas utilization by the host termite. Focus then progressed to culture-dependent microbiology and biochemical studies of host-symbiont complementarity, which revealed specific microhabitat requirements for symbionts and noncellulosic mechanisms of symbiosis (e.g., N2 fixation). Today, knowledge on termite symbiosis has accrued exponentially thanks to omic technologies that reveal symbiont identities, functions, and interdependence, as well as intricacies of host-symbiont complementarity. Moving forward, the merging of classical twentieth-century approaches with evolving omic tools should provide even deeper insights into host-symbiont interplay.

RevDate: 2021-01-08

Busch P, Suleiman M, Schäfers C, et al (2021)

A multi-omic screening approach for the discovery of thermoactive glycoside hydrolases.

Extremophiles : life under extreme conditions [Epub ahead of print].

Next-generation sequencing and computational biology have facilitated the implementation of new combinatorial screening approaches to discover novel enzymes of biotechnological interest. In this study, we describe the successful establishment of a multi-omic approach for the identification of thermostable hydrolase-encoding genes by determination of gene expression levels. We applied this combinatorial approach using an anaerobic enrichment culture from an Azorean hot spring sample grown on green coffee beans as recalcitrant substrate. An in-depth analysis of the microbial community resulted in microorganisms capable of metabolizing the selected substrate, such as the genera Caloramator, Dictyoglomus and Thermoanaerobacter as active and abundant microorganisms. To discover glycoside hydrolases, 90,342 annotated genes were screened for specific reaction types. A total number of 106 genes encoding cellulases (EC, beta-glucosidases (EC and endo-1,4-beta-mannosidases (EC were selected. Mapping of RNA-Seq reads to the related metagenome led to expression levels for each gene. Amongst those, 14 genes, encoding glycoside hydrolases, showed highest expression values, and were used for further cloning. Four proteins were biochemically characterized and were identified as thermoactive glycoside hydrolases with a broad substrate range. This work demonstrated that a combinatory omic approach is a suitable strategy identifying unique thermoactive enzymes from environmental samples.

RevDate: 2021-01-08

Lu Z, Xu Z, Kong L, et al (2020)

Functional Changes of the Community of Microbes With Ni-Dependent Enzyme Genes Accompany Adaptation of the Ruminal Microbiome to Urea-Supplemented Diets.

Frontiers in microbiology, 11:596681.

Urea is an inexpensive non-protein nitrogen source commonly supplemented to the diets of ruminants. It is cleaved to ammonia by bacterial ureases, which require Ni as a catalyst for ureolysis. The key event in the changes of the ruminal microbiome after urea supplementation remains unknown. We have therefore investigated changes in the ruminal microbiome and its community with Ni-dependent enzyme genes following urea supplementation and analyzed the associations of rumen environmental factors, including fermentation variables and Ni concentrations, with the compositional and functional changes of these communities. We found that urea supplementation increased urease activity and the concentrations of ammonia and Ni, and tended to increase concentrations of short chain fatty acids and acetate, whereas it decreased rumen pH and the L-/D-lactate ratio. With standards for genome completeness >60% and strain heterogeneity <10%, 20 bacterial species containing five Ni-dependent enzyme genes were detected in the metagenome sequences. For the five Ni-dependent enzyme genes, urea supplementation increased the relative abundances of genes of urease and acetyl-CoA synthase, whereas it decreased the relative abundances of genes of glyoxalase I, [NiFe]-hydrogenase, and lactate racemase. For the 20 microbes with Ni-dependent enzyme genes, urea supplementation increased the relative abundances of five bacteria exhibiting high capacities for the utilization of hemicellulose and pectin for butyrate and fatty acid biosynthesis. For the ruminal microbiome, urea supplementation increased the metagenomic capacities for hemicellulose and pectin degradation, butyrate generation, fatty acid biosynthesis, and carbon fixation, whereas it decreased the metagenomic capacities for starch degradation, propionate generation, and sulfur and nitrogen metabolism. Constrained correspondence analysis identified rumen ammonia and Ni concentrations as likely driving factors in the reshaping of the ruminal microbiome and, together with pH, of the community of microbes with Ni-dependent enzyme genes. Thus, the functional change of the latter community is probably an important event in the adaptation of the ruminal microbiome to urea-supplemented diets. This result provides a new perspective for the understanding of the effects of urea supplementation on rumen fermentation.

RevDate: 2021-01-08

Amanbayeva M, Anarkulova E, Bogoyavlenskiy A, et al (2021)

Metagenomic Exploration of Atelerix albiventris Gut Microbiome.

Microbiology resource announcements, 10(1):.

Here, we report the metagenomic analysis of the gut of Atelerix albiventris, an animal typically kept as a pet in Kazakhstan. In this case, shotgun metagenomic sequencing of the RNA and DNA viral community was performed.

RevDate: 2021-01-08

Babalola OO, Omotayo OP, NO Igiehon (2021)

Survey of Maize Rhizosphere Microbiome Using Shotgun Metagenomics.

Microbiology resource announcements, 10(1):.

Several processes which occur in the rhizosphere make it a vital region in plant development. However, studies that examine rhizosphere microbiomes and their functional potentials remain scarce. Shotgun metagenomics was employed here to evaluate the functional potentials of the maize rhizosphere microbiome of farms in two South African provinces.

RevDate: 2021-01-08

Ye X, Zhou L, Zhang Y, et al (2021)

Effect of host breeds on gut microbiome and serum metabolome in meat rabbits.

BMC veterinary research, 17(1):24.

BACKGROUND: Gut microbial compositional and functional variation can affect health and production performance of farm animals. Analysing metabolites in biological samples provides information on the basic mechanisms that affect the well-being and production traits in farm animals. However, the extent to which host breeds affect the gut microbiome and serum metabolome in meat rabbits is still unknown. In this study, the differences in phylogenetic composition and functional capacities of gut microbiota in two commercial rabbit breeds Elco and Ira were determined by 16S rRNA gene and metagenomic sequencing. The alternations in serum metabolome in the two rabbit breeds were detected using ultra-performance liquid chromatography system coupled with quadrupole time of flight mass spectrometry (UPLC-QTOFMS).

RESULTS: Sequencing results revealed that there were significant differences in the gut microbiota of the two breeds studied, suggesting that host breeds affect structure and diversity of gut microbiota. Numerous breed-associated microorganisms were identified at different taxonomic levels and most microbial taxa belonged to the families Lachnospiraceae and Ruminococcaceae. In particular, several short-chain fatty acids (SCFAs) producing species including Coprococcus comes, Ruminococcus faecis, Ruminococcus callidus, and Lachnospiraceae bacterium NK4A136 could be considered as biomarkers for improving the health and production performance in meat rabbits. Additionally, gut microbial functional capacities related to bacterial chemotaxis, ABC transporters, and metabolism of different carbohydrates, amino acids, and lipids varied greatly between rabbit breeds. Several fatty acids, amino acids, and organic acids in the serum were identified as breed-associated, where certain metabolites could be regarded as biomarkers correlated with the well-being and production traits of meat rabbits. Correlation analysis between breed-associated microbial species and serum metabolites revealed significant co-variations, indicating the existence of cross-talk among host-gut microbiome-serum metabolome.

CONCLUSIONS: Our study provides insight into how gut microbiome and serum metabolome of meat rabbits are affected by host breeds and uncovers potential biomarkers important for breed improvement of meat rabbits.

RevDate: 2021-01-08

Mustafa GR, Li C, Zhao S, et al (2021)

Metagenomic analysis revealed a wide distribution of antibiotic resistance genes and biosynthesis of antibiotics in the gut of giant pandas.

BMC microbiology, 21(1):15.

BACKGROUND: The gut microbiome is essential for the host's health and serves as an essential reservoir of antibiotic resistance genes (ARGs). We investigated the effects of different factors, including the dietary shifts and age, on the functional characteristics of the giant panda's gut microbiome (GPs) through shotgun metagenome sequencing. We explored the association between gut bacterial genera and ARGs within the gut based on network analysis.

RESULTS: Fecal samples (n=60) from captive juvenile, adult, and geriatric GPs were processed, and variations were identified in the gut microbiome according to different ages, the abundance of novel ARGs and the biosynthesis of antibiotics. Among 667 ARGs identified, nine from the top ten ARGs had a higher abundance in juveniles. For 102 ARGs against bacteria, a co-occurrence pattern revealed a positive association for predominant ARGs with Streptococcus. A comparative KEGG pathways analysis revealed an abundant biosynthesis of antibiotics among three different groups of GPs, where it was more significantly observed in the juvenile group. A co-occurrence pattern further revealed a positive association for the top ten ARGs, biosynthesis of antibiotics, and metabolic pathways.

CONCLUSION: Gut of GPs serve as a reservoir for novel ARGs and biosynthesis of antibiotics. Dietary changes and age may influence the gut microbiome's functional characteristics; however, it needs further studies to ascertain the study outcomes.

RevDate: 2021-01-08
CmpDate: 2021-01-08

Macey MC, Pratscher J, Crombie AT, et al (2020)

Impact of plants on the diversity and activity of methylotrophs in soil.

Microbiome, 8(1):31 pii:10.1186/s40168-020-00801-4.

BACKGROUND: Methanol is the second most abundant volatile organic compound in the atmosphere, with the majority produced as a metabolic by-product during plant growth. There is a large disparity between the estimated amount of methanol produced by plants and the amount which escapes to the atmosphere. This may be due to utilisation of methanol by plant-associated methanol-consuming bacteria (methylotrophs). The use of molecular probes has previously been effective in characterising the diversity of methylotrophs within the environment. Here, we developed and applied molecular probes in combination with stable isotope probing to identify the diversity, abundance and activity of methylotrophs in bulk and in plant-associated soils.

RESULTS: Application of probes for methanol dehydrogenase genes (mxaF, xoxF, mdh2) in bulk and plant-associated soils revealed high levels of diversity of methylotrophic bacteria within the bulk soil, including Hyphomicrobium, Methylobacterium and members of the Comamonadaceae. The community of methylotrophic bacteria captured by this sequencing approach changed following plant growth. This shift in methylotrophic diversity was corroborated by identification of the active methylotrophs present in the soils by DNA stable isotope probing using 13C-labelled methanol. Sequencing of the 16S rRNA genes and construction of metagenomes from the 13C-labelled DNA revealed members of the Methylophilaceae as highly abundant and active in all soils examined. There was greater diversity of active members of the Methylophilaceae and Comamonadaceae and of the genus Methylobacterium in plant-associated soils compared to the bulk soil. Incubating growing pea plants in a 13CO2 atmosphere revealed that several genera of methylotrophs, as well as heterotrophic genera within the Actinomycetales, assimilated plant exudates in the pea rhizosphere.

CONCLUSION: In this study, we show that plant growth has a major impact on both the diversity and the activity of methanol-utilising methylotrophs in the soil environment, and thus, the study contributes significantly to efforts to balance the terrestrial methanol and carbon cycle. Video abstract.

RevDate: 2021-01-07

Elmassry MM, Kim S, B Busby (2021)

Predicting drug-metagenome interactions: Variation in the microbial β-glucuronidase level in the human gut metagenomes.

PloS one, 16(1):e0244876 pii:PONE-D-20-25396.

Characterizing the gut microbiota in terms of their capacity to interfere with drug metabolism is necessary to achieve drug efficacy and safety. Although examples of drug-microbiome interactions are well-documented, little has been reported about a computational pipeline for systematically identifying and characterizing bacterial enzymes that process particular classes of drugs. The goal of our study is to develop a computational approach that compiles drugs whose metabolism may be influenced by a particular class of microbial enzymes and that quantifies the variability in the collective level of those enzymes among individuals. The present paper describes this approach, with microbial β-glucuronidases as an example, which break down drug-glucuronide conjugates and reactivate the drugs or their metabolites. We identified 100 medications that may be metabolized by β-glucuronidases from the gut microbiome. These medications included morphine, estrogen, ibuprofen, midazolam, and their structural analogues. The analysis of metagenomic data available through the Sequence Read Archive (SRA) showed that the level of β-glucuronidase in the gut metagenomes was higher in males than in females, which provides a potential explanation for the sex-based differences in efficacy and toxicity for several drugs, reported in previous studies. Our analysis also showed that infant gut metagenomes at birth and 12 months of age have higher levels of β-glucuronidase than the metagenomes of their mothers and the implication of this observed variability was discussed in the context of breastfeeding as well as infant hyperbilirubinemia. Overall, despite important limitations discussed in this paper, our analysis provided useful insights on the role of the human gut metagenome in the variability in drug response among individuals. Importantly, this approach exploits drug and metagenome data available in public databases as well as open-source cheminformatics and bioinformatics tools to predict drug-metagenome interactions.

RevDate: 2021-01-07

Barzkar N, Sohail M, Tamadoni Jahromi S, et al (2021)

Marine Bacterial Esterases: Emerging Biocatalysts for Industrial Applications.

Applied biochemistry and biotechnology [Epub ahead of print].

The marine ecosystem has been known to be a significant source of novel enzymes. Esterase enzymes (EC represent a diverse group of hydrolases that catalyze the cleavage and formation of ester bonds. Although esterases are widely distributed among marine organisms, only microbial esterases are of paramount industrial importance. This article discusses the importance of marine microbial esterases, their biochemical and kinetic properties, and their stability under extreme conditions. Since culture-dependent techniques provide limited insights into microbial diversity of the marine ecosystem, therefore, genomics and metagenomics approaches have widely been adopted in search of novel esterases. Additionally, the article also explains industrial applications of marine bacterial esterases particularly for the synthesis of optically pure substances, the preparation of enantiomerically pure drugs, the degradation of human-made plastics and organophosphorus compounds, degradation of the lipophilic components of the ink, and production of short-chain flavor esters.

RevDate: 2021-01-07

Chang H, Mishra R, Cen C, et al (2021)

Metagenomic Analyses Expand Bacterial and Functional Profiling Biomarkers for Colorectal Cancer in a Hainan Cohort, China.

Current microbiology [Epub ahead of print].

This study was conducted for the metagenomic analysis of stool samples from CRC affected individuals to identify biomarkers for CRC in Hainan, the only tropical island province of China. The gut microbiota of CRC patients differed significantly from that of healthy and reference database cohorts based on Aitchison distance and Bray-Cutis distance but there was no significant difference in alpha diversity. Furthermore, at the species level, 68 species were significantly altered including 37 CRC-enriched, such as, Fusobacterium nucleatum, Parvimonas micra, Gemella morbillorum, Citrobacter portucalensis, Alloprevotella sp., Shigella sonnei, Coriobacteriaceae bacterium, etc. Sixty-seven different metabolic pathways were acquired, and pathways involved in the synthesis of many amino acids were significantly declined. Besides, 2 identified antibiotic resistance genes performed well (area under the receive-operation curve AUC = 0.833, 95% CI 58.51-100%) compared with virulence factor genes. The results of the present study provide region-specific bacterial and functional biomarkers of gut microbiota for CRC patients in Hainan. Microbiota is considered as a non-invasive biomarker for the detection of CRC. Gut microbiota of different geographic regions should be further studied to expand the understanding of markers, especially for the China cohort due to diverse nationalities and lifestyles.

RevDate: 2021-01-07

St James AR, Lin J, RE Richardson (2021)

Relationship Between Peat Type and Microbial Ecology in Sphagnum-Containing Peatlands of the Adirondack Mountains, NY, USA.

Microbial ecology [Epub ahead of print].

Peatland microbial community composition varies with respect to a range of biological and physicochemical variables. While the extent of peat degradation (humification) has been linked to microbial community composition along vertical stratification gradients within peatland sites, across-site variations have been relatively unexplored. In this study, we compared microbial communities across ten pristine Sphagnum-containing peatlands in the Adirondack Mountains, NY, which represented three different peat types-humic fen peat, humic bog peat, and fibric bog peat. Using 16S amplicon sequencing and network correlation analysis, we demonstrate that microbial community composition is primarily linked to peat type, and that distinct taxa networks distinguish microbial communities in each type. Shotgun metagenomic sequencing of the active water table region (mesotelm) from two Sphagnum-dominated bogs-one with fibric peat and one with humic peat-revealed differences in primary carbon degradation pathways, with the fibric peat being dominated by carbohydrate metabolism and hydrogenotrophic methanogenesis, and the humic peat being dominated by aliphatic carbon metabolism and aceticlastic methanogenesis. Our results suggest that peat humification is a major factor driving microbial community dynamics across peatland ecosystems.

RevDate: 2021-01-07

Li W, KE Nelson (2021)

Microbial Species that Initially Colonize the Human Gut at Birth or in Early Childhood Can Stay in Human Body for Lifetime.

Microbial ecology [Epub ahead of print].

In recent years, many studies have described the composition and function of the human microbiome at different body sites and suggested a role for the microbiome in various diseases and health conditions. Some studies, using longitudinal samples, have also suggested how the microbiome changes over time due to disease, diet, development, travel, and other environmental factors. However, to date, no study has demonstrated whether the microorganisms established at birth or in early childhood, either transmitted from parents or obtained from the environment, can stay in the human body until adult or senior age. To directly answer this question is difficult, because microbiome samples at childhood and at later adulthood for the same individual will need to be compared and the field is not old enough to have allowed for that type of sample collection. Here, using a metagenomic approach, we analyzed 1004 gut microbiome samples from senior adults (65 ± 7.8 years) from the TwinsUK cohort. Our data indicate that many species in the human gut acquired in early childhood can stay for a lifetime until senior ages. We identified the rare genomic variants (single nucleotide variation and indels) for 27 prevalent species with enough sequencing coverage for confident genomic variant identification. We found that for some species, twin pairs, including both monozygotic (MZ) and dizygotic (DZ) twins, share significantly more rare variants than unrelated subject pairs. But no significant difference is found between MZ and DZ twin pairs. These observations strongly suggest that these species acquired in early childhood remained in these persons until senior adulthood.

RevDate: 2021-01-07

Hutchinson MI, Bell TAS, Gallegos-Graves V, et al (2021)

Merging Fungal and Bacterial Community Profiles via an Internal Control.

Microbial ecology [Epub ahead of print].

Integrated measurements of fungi and bacteria are critical to understand how interactions between these taxa drive key processes in ecosystems ranging from soils to animal guts. High-throughput amplicon sequencing is commonly used to census microbiomes, but the genetic markers targeted for fungi and bacteria (typically ribosomal regions) are domain-specific so profiling must be performed separately, obscuring relationships between these groups. To solve this problem, we developed a spike-in method with an internal control (IC) construct containing primer sites commonly used for bacterial and fungal taxonomic profiling. The internal control offers several advantages: estimation of absolute abundances, estimation of fungal to bacterial ratios (F:B), integration of bacterial and fungal profiles for holistic community analysis, and lower costs compared to other quantitation methods. To validate the IC as a scaling method, we compared IC-derived measures of F:B to measures from quantitative PCR (qPCR) using a commercial mock community (the ZymoBiomic Microbial Community DNA Standard II, containing two fungi and eight bacteria) and complex environmental samples. For both the mock community and the environmental samples, the IC produced F:B values that were statistically consistent with qPCR. Merging the environmental fungal and bacterial profiles based on the IC-derived F:B values revealed new relationships among samples in terms of community similarity. This IC method is the first spike-in method to employ a single construct for cross-domain amplicon sequencing, offering more reliable measurements.

RevDate: 2021-01-07

Gomez JA, TP Primm (2021)

A Slimy Business: the Future of Fish Skin Microbiome Studies.

Microbial ecology [Epub ahead of print].

Fish skin contains a mucosal microbiome for the largest and oldest group of vertebrates, a location ideal for microbial community ecology and practical applications in agriculture and veterinary medicine. These selective microbiomes are dominated by Proteobacteria, with compositions different from the surrounding water. Core taxa are a small percentage of those present and are currently functionally uncharacterized. Methods for skin sampling, DNA extraction and amplification, and sequence data processing are highly varied across the field, and reanalysis of recent studies using a consistent pipeline revealed that some conclusions did change in statistical significance. Further, the 16S gene sequencing approaches lack quantitation of microbes and copy number adjustment. Thus, consistency in the field is a serious limitation in comparing across studies. The most significant area for future study, requiring metagenomic and metabolomics data, is the biochemical pathways and functions within the microbiome community, the interactions between members, and the resulting effects on fish host health being linked to specific nutrients and microbial species. Genes linked to skin colonization, such as those for attachment or mucin degradation, need to be uncovered and explored. Skin immunity factors need to be directly linked to microbiome composition and individual taxa. The basic foundation has been laid, and many exciting future discoveries remain.

RevDate: 2021-01-07

To RK, Ramchandar N, Gupta A, et al (2020)

Use of Plasma Metagenomic Next-generation Sequencing for Pathogen Identification in Pediatric Endocarditis.

The Pediatric infectious disease journal, Publish Ahead of Print: pii:00006454-900000000-95922 [Epub ahead of print].

Pediatric infective endocarditis incurs significant morbidity and generally occurs among children with underlying heart disease. Identification of a pathogen is critical in determining appropriate therapy. However, standard diagnostic testing has limited sensitivity. We describe a case series of children with infective endocarditis in whom plasma next-generation sequencing (Karius, Redwood, CA) identified an organism in 8 of 10 cases.

RevDate: 2021-01-07

Xu SF, Tian Q, Tian YL, et al (2021)

Detection of infectious pathogens located in the peripheral lung field by metagenomic next-generation sequencing combined with virtual bronchoscopic navigation.

Chinese medical journal, Publish Ahead of Print: pii:00029330-900000000-98797 [Epub ahead of print].

RevDate: 2021-01-07

Ng E, Tay JRH, Balan P, et al (2021)

Metagenomic sequencing provides new insights into the subgingival bacteriome and aetiopathology of periodontitis.

Journal of periodontal research [Epub ahead of print].

"Open-ended" molecular techniques such as 16S rRNA sequencing have revealed that the oral bacteriome of subgingival plaque is more diverse than originally thought. 16S rRNA analysis has demonstrated that constituents of the overall bacterial community are qualitatively similar in health and disease, differing mainly in their relative proportions with respect to each other. Species in low abundance can also act as critical species, leading to the concept of global community dysbiosis which relates to shifts in community structure, rather than shifts in membership. Correlation analysis suggests that coordinated interactions in the community are essential for incipient dysbiosis and disease pathogenesis. The subgingival bacteriome also provides biomarkers that are useful for disease detection and management. Combined with clinical and biological parameters, these may assist clinicians in developing and implementing effective treatment strategies to restore microbial homeostasis and monitor disease. Identification of higher risk groups or poor responders to treatment using unique subgingival bacteriome signatures may also lead to early intervention.

RevDate: 2021-01-07

Joshi N, Kaushal G, SP Singh (2021)

Biochemical characterization of a novel thermo-halo-tolerant GH5 endoglucanase from a thermal spring metagenome.

Biotechnology and bioengineering [Epub ahead of print].

A novel endoglucanase gene, celM , was cloned from a thermal spring metagenome. The gene was expressed in Escherichia coli, and the protein was extracted and purified. The protein catalysed the hydrolysis of amorphous cellulose in a wide range of temperature, 30°C to 95°C, with optimal activity at 80°C. It was able to tolerate high temperature (80°C) with a half-life of 8 h. Its activity was eminent in a wide pH range of 3.0 to 11.0, with the highest activity at pH 6.0. The enzyme was tested for halostability. Any significant loss was not recorded in the activity of CelM after the exposure to salinity (3M NaCl) for 30 days. Furthermore, CelM displayed substantial resistance towards metal ions, denaturant, reducing agent, organic solvent, and non-ionic surfactants. The amorphous cellulose, treated with CelM , was randomly cleaved, generating cellooligosaccharides of 2 to 5 degree of polymerization. Furthermore, CelM was demonstrated to catalyse the hydrolysis of cellulose fraction in the delignified biomass samples, e.g., sweet sorghum bagasse, rice straw, and corncob, into cello-oligosaccharides. Given that CelM is a thermo-halo-tolerant GH5 endoglucanase, with resistance to detergents and organic solvent, the biocatalyst could be of potential usefulness for a variety of industrial applications. This article is protected by copyright. All rights reserved.

RevDate: 2021-01-07

Lyu Y, Yang T, Liu H, et al (2021)

Enrichment and characterization of an effective hexavalent chromium-reducing microbial community YEM001.

Environmental science and pollution research international [Epub ahead of print].

Chromium (Cr) is one of the most widely used heavy metals in industrial processes, resulting in water and soil pollution that seriously threaten environmental safety. In this paper, we have directionally enriched a Cr(VI)-reducing bacterial community YEM001 from no-Cr(VI) polluted pond sedimental sludge by selectively growing it in Cr(VI)-containing media. This community could effectively reduce Cr(VI) in laboratory rich media containing different concentrations of Cr(VI), such as 61% reduction at 435 mg/L Cr(VI), 85% reduction at 355 mg/L Cr(VI), and complete reduction at 269 mg/L Cr(VI) in 93.5 h. It was also able to completely reduce 100 mg/L and 300 mg/L Cr(VI) in landfill leachate and natural sludge in 48 h, respectively. Optimal pH for Cr(VI) reduction of the YEM001 is between 7 and 8 and the best efficiency for Cr(VI) reduction occurs at 30 °C. Metagenomic data demonstrated that the YEM001 community was composed of multiple bacteria, including well-known Cr(VI)-reducing bacteria and non-Cr(VI)-reducing bacteria. Delftia, Comamonas, Alicycliphilus, Acidovorax, Bacillus, and Clostridioides account for 83% of total community abundance. The stability of the composition of the YEM001 community and its Cr(VI)-reducing activity allows for its application in bioremediation of environmental Cr(VI) pollution.

RevDate: 2021-01-07

Plyusnin I, Kant R, Jääskeläinen AJ, et al (2020)

Novel NGS pipeline for virus discovery from a wide spectrum of hosts and sample types.

Virus evolution, 6(2):veaa091 pii:veaa091.

The study of the microbiome data holds great potential for elucidating the biological and metabolic functioning of living organisms and their role in the environment. Metagenomic analyses have shown that humans, along with for example, domestic animals, wildlife and arthropods, are colonized by an immense community of viruses. The current Coronavirus pandemic (COVID-19) heightens the need to rapidly detect previously unknown viruses in an unbiased way. The increasing availability of metagenomic data in this era of next-generation sequencing (NGS), along with increasingly affordable sequencing technologies, highlight the need for reliable and comprehensive methods to manage such data. In this article, we present a novel bioinformatics pipeline called LAZYPIPE for identifying both previously known and novel viruses in host associated or environmental samples and give examples of virus discovery based on it. LAZYPIPE is a Unix-based pipeline for automated assembling and taxonomic profiling of NGS libraries implemented as a collection of C++, Perl, and R scripts.

RevDate: 2021-01-07

Luo ZH, Li Q, Lai Y, et al (2020)

Diversity and Genomic Characterization of a Novel Parvarchaeota Family in Acid Mine Drainage Sediments.

Frontiers in microbiology, 11:612257.

Recent genome-resolved metagenomic analyses of microbial communities from diverse environments have led to the discovery of many novel lineages that significantly expand the phylogenetic breadth of Archaea. Here, we report the genomic characterization of a new archaeal family based on five metagenome-assembled genomes retrieved from acid mine drainage sediments. Phylogenomic analyses placed these uncultivated archaea at the root of the candidate phylum Parvarchaeota, which expand this lesser-known phylum into two family levels. Genes involved in environmental adaptation and carbohydrate and protein utilization were identified in the ultra-small genomes (estimated size 0.53-0.76 Mb), indicating a survival strategy in this harsh environment (low pH and high heavy metal content). The detection of genes with homology to sulfocyanin suggested a potential involvement in iron cycling. Nevertheless, the absence of the ability to synthesize amino acids and nucleotides implies that these archaea may acquire these biomolecules from the environment or other community members. Applying evolutionary history analysis to Parvarchaeota suggested that members of the two families could broaden their niches by acquiring the potentials of utilizing different substrates. This study expands our knowledge of the diversity, metabolic capacity, and evolutionary history of the Parvarchaeota.

RevDate: 2021-01-07

Perini N, Mercuri F, Orlanducci S, et al (2020)

The Integration of Metagenomics and Chemical Physical Techniques Biodecoded the Buried Traces of the Biodeteriogens of Parchment Purple Spots.

Frontiers in microbiology, 11:598945.

Ancient parchments record an immense part of our cultural heritage, having been used as the main written support material for centuries. Parchment easily undergoes biodeterioration, whose main signs are the so-called purple spots, which often lead to detachment of the superficial written layer. Up to recent years, several studies have been analyzing damaged parchments from different world's archives, trying to trace back the culprit of the purple spots. However, standard cultivation and early molecular techniques have been demonstrated to be unsuccessful, leading the parchment damage issue remaining unsolved for many years. Nowadays, some studies have explored the parchment biodeterioration dynamics by adopting a multidisciplinary approach combining standard microbiological methods with high-throughput molecular, chemical and physical techniques. This approach allowed an unprecedented level of knowledge on the complex dynamics of parchment biodeterioration. This mini review discusses the application of the combination of basic and high-throughput techniques to study historical parchments, highlighting the strengths and weaknesses of this approach. In particular, it focuses on how metagenomics has been paramount for the unequivocal identification of the microbial main actors of parchment biodeterioration and their dynamics, but also on how metagenomics may suffer the distortion inflict by the historical perspective on the analysis of ancient specimens. As a whole, this mini review aims to describe the scenario of information on parchment biodeterioration obtained so far by using the integration of metagenomic with recent chemical (Raman spectroscopy) and physical (Light Transmission Analysis) approaches, which might have key implications in the preservation of many ancient documents.

RevDate: 2021-01-07

Zhang HT, Wang H, Wu HS, et al (2021)

Comparison of viromes in vaginal secretion from pregnant women with and without vaginitis.

Virology journal, 18(1):11.

BACKGROUND: Although some studies have investigated the bacterial community in vaginal tract of pregnant women, there are few reports about the viral community (virome) in this type of microenvironment.

METHODS: To investigate the composition of virome in vaginal secretion samples, 40 vaginal secretion samples from pregnant women with vaginitis and 20 vaginal secretion samples from pregnant women without vaginitis, pooled into 4 and 2 sample pools, respectively, were subjected to viral metagenomic analysis.

RESULTS: Results indicated virus sequences showing similarity to human papillomavirus (HPV), anellovirus, and norovirus were recovered from this cohort of pregnant women. Further analysis indicated that 15 different defined types and one unclassified type of HPV were detected from pregnant women with vaginitis while only 3 defined types of HPV were detected in pregnant women without vaginitis. Five different groups of viruses from the family Anelloviridae were present in pregnant women with but none of them were detected in pregnant women without vaginitis. Norovirus was detected in 3 out of the 4 sample pools from pregnant women with vaginitis but none in the pregnant women without vaginitis. Twelve complete genomes belonging to 10 different types of HPV, and 5 novel anllovirus genomes belonging 2 different genera in Anelloviridae were acquired from these libraries, based on which phylogenetical analysis and pairwise sequence comparison were performed. Phageome in these samples was also briefly characterized and compared between two groups.

CONCLUSION: Our data suggested that virome might play an important role in the progression of vaginitis in pregnant women.

RevDate: 2021-01-07

Chi H, Cao W, Zhang M, et al (2021)

Environmental noise stress disturbs commensal microbiota homeostasis and induces oxi-inflammmation and AD-like neuropathology through epithelial barrier disruption in the EOAD mouse model.

Journal of neuroinflammation, 18(1):9.

BACKGROUND: Both genetic factors and environmental hazards, including environmental noise stress, have been associated with gut microbiome that exacerbates Alzheimer's disease (AD) pathology. However, the role and mechanism of environmental risk factors in early-onset AD (EOAD) pathogenesis remain unclear.

METHODS: The molecular pathways underlying EOAD pathophysiology following environmental noise exposure were evaluated using C57BL/6 wild-type (WT) and APP/PS1 Tg mouse models. The composition differences in intestinal microbiota were analyzed by 16S rRNA sequencing and Tax4Fun to predict the metagenome content from sequencing results. An assessment of the flora dysbiosis-triggered dyshomeostasis of oxi-inflamm-barrier and the effects of the CNS end of the gut-brain axis was conducted to explore the underlying pathological mechanisms.

RESULTS: Both WT and APP/PS1 mice showed a statistically significant relationship between environmental noise and the taxonomic composition of the corresponding gut microbiome. Bacterial-encoded functional categories in noise-exposed WT and APP/PS1 mice included phospholipid and galactose metabolism, oxidative stress, and cell senescence. These alterations corresponded with imbalanced intestinal oxidation and anti-oxidation systems and low-grade systemic inflammation following noise exposure. Mechanistically, axis-series experiments demonstrated that following noise exposure, intestinal and hippocampal tight junction protein levels reduced, whereas serum levels of inflammatory mediator were elevated. Regarding APP/PS1 overexpression, noise-induced abnormalities in the gut-brain axis may contribute to aggravation of neuropathology in the presymptomatic stage of EOAD mice model.

CONCLUSION: Our results demonstrate that noise exposure has deleterious effects on the homeostasis of oxi-inflamm-barrier in the microbiome-gut-brain axis. Therefore, at least in a genetic context, chronic noise may aggravate the progression of EOAD.

RevDate: 2021-01-07

Avedi EK, Adediji AO, Kilalo DC, et al (2021)

Metagenomic analyses and genetic diversity of Tomato leaf curl Arusha virus affecting tomato plants in Kenya.

Virology journal, 18(1):2.

BACKGROUND: Tomato production is threatened worldwide by the occurrence of begomoviruses which are associated with tomato leaf curl diseases. There is little information on the molecular properties of tomato begomoviruses in Kenya, hence we investigated the population and genetic diversity of begomoviruses associated with tomato leaf curl in Kenya.

METHODS: Tomato leaf samples with virus-like symptoms were obtained from farmers' field across the country in 2018 and Illumina sequencing undertaken to determine the genetic diversity of associated begomoviruses. Additionally, the occurrence of selection pressure and recombinant isolates within the population were also evaluated.

RESULTS: Twelve complete begomovirus genomes were obtained from our samples with an average coverage of 99.9%. The sequences showed 95.7-99.7% identity among each other and 95.9-98.9% similarities with a Tomato leaf curl virus Arusha virus (ToLCArV) isolate from Tanzania. Analysis of amino acid sequences showed the highest identities in the regions coding for the coat protein gene (98.5-100%) within the isolates, and 97.1-100% identity with the C4 gene of ToLCArV. Phylogenetic algorithms clustered all Kenyan isolates in the same clades with ToLCArV, thus confirming the isolates to be a variant of the virus. There was no evidence of recombination within our isolates. Estimation of selection pressure within the virus population revealed the occurrence of negative or purifying selection in five out of the six coding regions of the sequences.

CONCLUSIONS: The begomovirus associated with tomato leaf curl diseases of tomato in Kenya is a variant of ToLCArV, possibly originating from Tanzania. There is low genetic diversity within the virus population and this information is useful in the development of appropriate management strategies for the disease in the country.

RevDate: 2021-01-07

Xie Y, Sun J, Wei L, et al (2021)

Altered gut microbiota correlate with different immune responses to HAART in HIV-infected individuals.

BMC microbiology, 21(1):11.

BACKGROUND: Although gut microbiota dysbiosis has been reported in HIV infected individuals recently, the relationship between the gut microbiota and immune activation in patients with different immune responses to highly active antiretroviral therapy (HAART) is still not well understood. Gut microbiota and immune activation were studied in 36 non-HIV-infected subjects (healthy controls) and 58 HIV-infected individuals, including 28 immunological responders (IR) and 30 immunological non-responders (INR) (≥500 and < 200 CD4+ T-cell counts/μl after 2 years of HIV-1 viral suppression respectively) without comorbidities.

RESULTS: Metagenome sequencing revealed that HIV-infected immunological responders and immunological non-responders could not recover completely from the gut microbiota dysbiosis. At a 97% similarity level, the relative abundances of Fusobacterium, Ruminococcus gnavus and Megamonas were greater, whereas Faecalibacterium, Alistipes, Bifidobacterium, Eubacterium rectale and Roseburia were more depleted in the IR and INR groups than those in the healthy controls. Ruminococcaceae and Alistipes were positively correlated with nadir and current CD4+ T-cell counts, but negatively correlated with CD8 + CD57+ T-cell counts. Inflammation markers and translocation biomarkers (LPS) levels were positively correlated with the abundances of genera Ruminococcus and Fusobacterium but were negatively correlated with the genus Faecalibacterium. The relative abundances of Escherichia-Shigella and Blautia were significantly higher in the IR than those in the INR group. Escherichia-Shigella were negatively correlated with the CD4/CD8 ratio but positively correlated with the amount of CD8 + CD57+ T-cells. Roseburia and Blautia were negatively associated with nadir CD4+ T-cell and positively associated with CD8 + CD57+ T-cell counts.

CONCLUSIONS: Gut microbiota dysbiosis may be one of the factors contributing to different immune responses and treatment outcomes to HAART.

RevDate: 2021-01-07

Li J, Si H, Du H, et al (2021)

Comparison of gut microbiota structure and Actinobacteria abundances in healthy young adults and elderly subjects: a pilot study.

BMC microbiology, 21(1):13.

BACKGROUND: The aim was to determine the potential association of the gut microbiota composition, especially the abundance of Actinobacteria, as well as the differentiation of functional and resistance genes with age (young adults vs elderly subjects) in China.

RESULTS: The patterns of relative abundance of all bacteria isolated from fecal samples differed between young adults and elderly subjects, but the alpha diversity (Chao1 P = 0.370, Shannon P = 0.560 and Simpson P = 0.270) and beta diversity (ANOSIM R = 0.031, P = 0.226) were not significantly different. There were 3 Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathways (carbon metabolism, inositol phosphate metabolism, and sesquiterpenoid and triterpenoid biosynthesis) and 7 antibiotic resistant genes (ARGs) (macrolide lincosamide-streptogramin B (MLSB), tetracycline, aminoglycoside, sulfonamide, fosmidomycin, lincomycin, and vancomycin) that showed significant differences between the 2 groups (all P < 0.05). The abundance of Actinomycetes was enriched (about 2.4-fold) in young adults. Bifidobacteria dominated in both young adults and elderly subjects, with overall higher abundances in young adults (P > 0.05). Only the Bifidobacterium_dentium species showed significant differences between the 2 groups (P = 0.013), with a higher abundance in elderly subjects but absent in young adults.

CONCLUSIONS: The present study revealed that there were 3 KEGG metabolic pathways and 7 ARGs as well as enhanced Bifidobacterium_dentium species abundance in elderly compared to young subjects.

RevDate: 2021-01-07

Jing G, Zhang Y, Cui W, et al (2021)

Meta-Apo improves accuracy of 16S-amplicon-based prediction of microbiome function.

BMC genomics, 22(1):9.

BACKGROUND: Due to their much lower costs in experiment and computation than metagenomic whole-genome sequencing (WGS), 16S rRNA gene amplicons have been widely used for predicting the functional profiles of microbiome, via software tools such as PICRUSt 2. However, due to the potential PCR bias and gene profile variation among phylogenetically related genomes, functional profiles predicted from 16S amplicons may deviate from WGS-derived ones, resulting in misleading results.

RESULTS: Here we present Meta-Apo, which greatly reduces or even eliminates such deviation, thus deduces much more consistent diversity patterns between the two approaches. Tests of Meta-Apo on > 5000 16S-rRNA amplicon human microbiome samples from 4 body sites showed the deviation between the two strategies is significantly reduced by using only 15 WGS-amplicon training sample pairs. Moreover, Meta-Apo enables cross-platform functional comparison between WGS and amplicon samples, thus greatly improve 16S-based microbiome diagnosis, e.g. accuracy of gingivitis diagnosis via 16S-derived functional profiles was elevated from 65 to 95% by WGS-based classification. Therefore, with the low cost of 16S-amplicon sequencing, Meta-Apo can produce a reliable, high-resolution view of microbiome function equivalent to that offered by shotgun WGS.

CONCLUSIONS: This suggests that large-scale, function-oriented microbiome sequencing projects can probably benefit from the lower cost of 16S-amplicon strategy, without sacrificing the precision in functional reconstruction that otherwise requires WGS. An optimized C++ implementation of Meta-Apo is available on GitHub (https://github.com/qibebt-bioinfo/meta-apo) under a GNU GPL license. It takes the functional profiles of a few paired WGS:16S-amplicon samples as training, and outputs the calibrated functional profiles for the much larger number of 16S-amplicon samples.

RevDate: 2021-01-07

Noone JC, Helmersen K, Leegaard TM, et al (2021)

Rapid Diagnostics of Orthopaedic-Implant-Associated Infections Using Nanopore Shotgun Metagenomic Sequencing on Tissue Biopsies.

Microorganisms, 9(1): pii:microorganisms9010097.

Conventional culture-based diagnostics of orthopaedic-implant-associated infections (OIAIs) are arduous. Hence, the aim of this study was to evaluate a culture-independent, rapid nanopore-based diagnostic protocol with regard to (a) pathogen identification, (b) time to pathogen identification, and (c) identification of antimicrobial resistance (AMR). This prospective proof-of-concept study included soft tissue biopsies from 32 patients with OIAIs undergoing first revision surgery at Akershus University Hospital, Norway. The biopsies were divided into two segments. Nanopore shotgun metagenomic sequencing and pathogen and antimicrobial resistance gene identification using the EPI2ME analysis platform (Oxford Nanopore Technologies) were performed on one segment. Conventional culture-based diagnostics were performed on the other. Microbial identification matched in 23/32 OIAI patients (72%). Sequencing detected additional microbes in 9/32 patients. Pathogens detected by culturing were identified by sequencing within a median of 1 h of sequencing start [range 1-18 h]. Phenotypic AMR was explained by the detection of resistance genes in 11/23 patients (48%). Diagnostics of OIAIs using shotgun metagenomics sequencing are possible within 24 h from biopsy using nanopore technology. Sequencing outperformed culturing with respect to speed and pathogen detection where pathogens were at sufficient concentration, whereas culture-based methods had an advantage at lower pathogen concentrations. Sequencing-based AMR detection may not yet be a suitable replacement for culture-based antibiotic susceptibility testing.

RevDate: 2021-01-06

Taylor JC, Gao X, Xu J, et al (2021)

A type VII secretion system of Streptococcus gallolyticus subsp. gallolyticus contributes to gut colonization and the development of colon tumors.

PLoS pathogens, 17(1):e1009182 pii:PPATHOGENS-D-20-01855 [Epub ahead of print].

Streptococcus gallolyticus subspecies gallolyticus (Sgg) has a strong clinical association with colorectal cancer (CRC) and actively promotes the development of colon tumors. However, the molecular determinants involved in Sgg pathogenicity in the gut are unknown. Bacterial type VII secretion systems (T7SS) mediate pathogen interactions with their host and are important for virulence in pathogenic mycobacteria and Staphylococcus aureus. Through genome analysis, we identified a locus in Sgg strain TX20005 that encodes a putative type VII secretion system (designated as SggT7SST05). We showed that core genes within the SggT7SST05 locus are expressed in vitro and in the colon of mice. Western blot analysis showed that SggEsxA, a protein predicted to be a T7SS secretion substrate, is detected in the bacterial culture supernatant, indicating that this SggT7SST05 is functional. Deletion of SggT7SST05 (TX20005Δesx) resulted in impaired bacterial adherence to HT29 cells and abolished the ability of Sgg to stimulate HT29 cell proliferation. Analysis of bacterial culture supernatants suggest that SggT7SST05-secreted factors are responsible for the pro-proliferative activity of Sgg, whereas Sgg adherence to host cells requires both SggT7SST05-secreted and bacterial surface-associated factors. In a murine gut colonization model, TX20005Δesx showed significantly reduced colonization compared to the parent strain. Furthermore, in a mouse model of CRC, mice exposed to TX20005 had a significantly higher tumor burden compared to saline-treated mice, whereas those exposed to TX20005Δesx did not. Examination of the Sgg load in the colon in the CRC model suggests that SggT7SST05-mediated activities are directly involved in the promotion of colon tumors. Taken together, these results reveal SggT7SST05 as a previously unrecognized pathogenicity determinant for Sgg colonization of the colon and promotion of colon tumors.


RJR Experience and Expertise


Robbins holds BS, MS, and PhD degrees in the life sciences. He served as a tenured faculty member in the Zoology and Biological Science departments at Michigan State University. He is currently exploring the intersection between genomics, microbial ecology, and biodiversity — an area that promises to transform our understanding of the biosphere.


Robbins has extensive experience in college-level education: At MSU he taught introductory biology, genetics, and population genetics. At JHU, he was an instructor for a special course on biological database design. At FHCRC, he team-taught a graduate-level course on the history of genetics. At Bellevue College he taught medical informatics.


Robbins has been involved in science administration at both the federal and the institutional levels. At NSF he was a program officer for database activities in the life sciences, at DOE he was a program officer for information infrastructure in the human genome project. At the Fred Hutchinson Cancer Research Center, he served as a vice president for fifteen years.


Robbins has been involved with information technology since writing his first Fortran program as a college student. At NSF he was the first program officer for database activities in the life sciences. At JHU he held an appointment in the CS department and served as director of the informatics core for the Genome Data Base. At the FHCRC he was VP for Information Technology.


While still at Michigan State, Robbins started his first publishing venture, founding a small company that addressed the short-run publishing needs of instructors in very large undergraduate classes. For more than 20 years, Robbins has been operating The Electronic Scholarly Publishing Project, a web site dedicated to the digital publishing of critical works in science, especially classical genetics.


Robbins is well-known for his speaking abilities and is often called upon to provide keynote or plenary addresses at international meetings. For example, in July, 2012, he gave a well-received keynote address at the Global Biodiversity Informatics Congress, sponsored by GBIF and held in Copenhagen. The slides from that talk can be seen HERE.


Robbins is a skilled meeting facilitator. He prefers a participatory approach, with part of the meeting involving dynamic breakout groups, created by the participants in real time: (1) individuals propose breakout groups; (2) everyone signs up for one (or more) groups; (3) the groups with the most interested parties then meet, with reports from each group presented and discussed in a subsequent plenary session.


Robbins has been engaged with photography and design since the 1960s, when he worked for a professional photography laboratory. He now prefers digital photography and tools for their precision and reproducibility. He designed his first web site more than 20 years ago and he personally designed and implemented this web site. He engages in graphic design as a hobby.

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E-mail: RJR8222@gmail.com

Collection of publications by R J Robbins

Reprints and preprints of publications, slide presentations, instructional materials, and data compilations written or prepared by Robert Robbins. Most papers deal with computational biology, genome informatics, using information technology to support biomedical research, and related matters.

Research Gate page for R J Robbins

ResearchGate is a social networking site for scientists and researchers to share papers, ask and answer questions, and find collaborators. According to a study by Nature and an article in Times Higher Education , it is the largest academic social network in terms of active users.

Curriculum Vitae for R J Robbins

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Curriculum Vitae for R J Robbins

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RJR Picks from Around the Web (updated 11 MAY 2018 )