Deep Metagenomic Sequencing Research Articles

Comparison of metagenomic and targeted methods for sequencing human pathogenic viruses from wastewater.

Most public health initiatives that monitor viruses in wastewater have utilized quantitative polymerase chain reaction (PCR) and whole genome PCR sequencing, mirroring techniques used for viral epidemiology in individuals. These techniques require prior knowledge of the target viral genome and are limited to monitoring individual or small groups of viruses. Metagenomic sequencing may offer an alternative strategy for monitoring a broad spectrum of viruses in wastewater, including novel and emerging pathogens. In this study, while amplicon sequencing gave high viral genome coverage, untargeted shotgun sequencing of total nucleic acid samples was unable to detect human pathogenic viruses with enough sensitivity for use in genomic epidemiology. Enrichment of shotgun libraries for respiratory viruses using hybrid-capture technology provided genotypic information on a range of viruses simultaneously, indicating strong potential for wastewater surveillance. This type of targeted metagenomics could be used for monitoring diverse targets, such as pathogens or antimicrobial resistance genes, in environmental samples.

Metagenome-wide analysis uncovers gut microbial signatures and implicates taxon-specific functions in end-stage renal disease

BackgroundThe gut microbiota plays a crucial role in regulating host metabolism and producing uremic toxins in patients with end-stage renal disease (ESRD). Our objective is to advance toward a holistic understanding of the gut ecosystem and its functional capacity in such patients, which is still lacking.ResultsHerein, we explore the gut microbiome of 378 hemodialytic ESRD patients and 290 healthy volunteers from two independent cohorts via deep metagenomic sequencing and metagenome-assembled-genome-based characterization of their feces. Our findings reveal fundamental alterations in the ESRD microbiome, characterized by a panel of 348 differentially abundant species, including ESRD-elevated representatives of Blautia spp., Dorea spp., and Eggerthellaceae, and ESRD-depleted Prevotella and Roseburia species. Through functional annotation of the ESRD-associated species, we uncover various taxon-specific functions linked to the disease, such as antimicrobial resistance, aromatic compound degradation, and biosynthesis of small bioactive molecules. Additionally, we show that the gut microbial composition can be utilized to predict serum uremic toxin concentrations, and based on this, we identify the key toxin-contributing species. Furthermore, our investigation extended to 47 additional non-dialyzed chronic kidney disease (CKD) patients, revealing a significant correlation between the abundance of ESRD-associated microbial signatures and CKD progression.ConclusionThis study delineates the taxonomic and functional landscapes and biomarkers of the ESRD microbiome. Understanding the role of gut microbiota in ESRD could open new avenues for therapeutic interventions and personalized treatment approaches in patients with this condition.

The intratumor mycobiome promotes lung cancer progression via myeloid-derived suppressor cells

Although polymorphic microbiomes have emerged as hallmarks of cancer, far less is known about the role of the intratumor mycobiome as living microorganisms in cancer progression. Here, using fungi-enriched DNA extraction and deep shotgun metagenomic sequencing, we have identified enriched tumor-resident Aspergillus sydowii in patients with lung adenocarcinoma (LUAD). By three different syngeneic lung cancer mice models, we find that A.sydowii promotes lung tumor progression via IL-1β-mediated expansion and activation of MDSCs, resulting in suppressed activity of cytotoxic T lymphocyte cells and accumulation of PD-1+ CD8+ Tcells. This is mediated by IL-1β secretion via β-glucan/Dectin-1/CARD9 pathway. Analysis of human samples confirms that enriched A.sydowii is associated with immunosuppression and poor patient outcome. Our findings suggest that intratumor mycobiome, albeit at low biomass, promotes lung cancer progression and could be targeted at the strain level to improve patients with LUAD outcome.

Heterogenous pathogen profile associated with acute conjunctivitis in Nepal.

Infectious conjunctivitis is common in Nepal. This prospective study recruited 60 patients with presumed acute infectious conjunctivitis from the B.P. Koirala Lions Center for Ophthalmic Studies in Kathmandu, Nepal. Swabs from the conjunctiva and anterior nares were processed for metagenomic RNA deep sequencing (RNA-seq). Pathogens were identified in 55% of cases. RNA viruses were the most common pathogen class identified. Severe acute respiratory syndrome coronavirus 2 was the most common RNA virus identified. Acute infectious conjunctivitis varies by location. Contrary to expectations, RNA viruses predominated. Repeat surveillance may be useful and RNA-seq allows for detection of the unexpected pathogen including RNA viruses.

A catalog of microbial genes and metagenome-assembled genomes from the quail gut microbiome

The gut microbiome plays an important role in quail feed efficiency, immunity, production, and even behavior. Gut microbial gene catalogs and reference genomes are important for understanding the quail gut microbiome. However, quail gut microbes are lacked sequenced genomes and functional information to date. In this study, we report the first catalog of the microbial genes and metagenome-assembled genomes (MAGs) in fecal and cecum luminal content samples from 3 quail breeds using deep metagenomic sequencing. We identified a total of 2,419,425 nonredundant genes in the quail genome catalog, and a total of 473 MAGs were reconstructed through binning analysis. At 95% average nucleotide identity, the 473 MAGs were clustered into 283 species-level genome bins (SGBs), of which 225 SGBs belonged to species without any available genomes in the current database. Based on the quail gene catalog and MAGs, we identified 142 discriminative bacterial species and 244 discriminative MAGs between Chinese yellow quails and Japanese quails. The discriminative MAGs suggested a strain-level difference in the gut microbial composition. Additionally, a total of 25 Kyoto Encyclopedia of Genes and Genomes functional terms and 88 carbohydrate-active enzymes were distinctly enriched between Chinese yellow quails and Japanese quails. Most of the different species and MAGs were significantly interrelated with the shifts in the functional capacities of the quail gut microbiome. Taken together, we constructed a quail gut microbial gene catalog and enlarged the reference of quail gut microbial genomes. The results of this study provide a powerful and invaluable resource for quail gut microbiome-related research.

MetaTransformer: deep metagenomic sequencing read classification using self-attention models.

Deep learning has emerged as a paradigm that revolutionizes numerous domains of scientific research. Transformers have been utilized in language modeling outperforming previous approaches. Therefore, the utilization of deep learning as a tool for analyzing the genomic sequences is promising, yielding convincing results in fields such as motif identification and variant calling. DeepMicrobes, a machine learning-based classifier, has recently been introduced for taxonomic prediction at species and genus level. However, it relies on complex models based on bidirectional long short-term memory cells resulting in slow runtimes and excessive memory requirements, hampering its effective usability. We present MetaTransformer, a self-attention-based deep learning metagenomic analysis tool. Our transformer-encoder-based models enable efficient parallelization while outperforming DeepMicrobes in terms of species and genus classification abilities. Furthermore, we investigate approaches to reduce memory consumption and boost performance using different embedding schemes. As a result, we are able to achieve 2× to 5× speedup for inference compared to DeepMicrobes while keeping a significantly smaller memory footprint. MetaTransformer can be trained in 9hours for genus and 16hours for species prediction. Our results demonstrate performance improvements due to self-attention models and the impact of embedding schemes in deep learning on metagenomic sequencing data.

Anthropogenic and natural disturbances along a river and its estuary alter the diversity of pathogens and antibiotic resistance mechanisms

Antibiotic resistance (AMR) in pathogens threatens human health worldwide, and antibiotic-resistant bacteria (ARB) are widespread in the environment. In particular, anthropogenically-disturbed rivers became reservoirs of ARBs and hotspots of antibiotic resistance gene (ARG) transmission. However, the diversity and sources of ARB, and the mechanisms of ARG transmission are not fully known. Here, we used deep metagenomic sequencing to study the dynamics of pathogens and their antibiotic resistance mechanisms along the Alexander River (Israel), affected by sewage and animal farm runoffs. Putative pathogens such as Aeromicrobium marinum and Mycobacterium massilipolynesiensis were enriched in western stations, following the inputs of polluted Nablus River. Aeromonas veronii was dominant in eastern stations in Spring. Several AMR mechanisms showed distinct patterns in Summer-Spring (dry season) and Winter (rainy season). We found low abundance beta-lactamases conferring carbapenem resistance: e.g., OXA-912 was linked to A. veronii in Spring; OXA-119 and OXA-205 to Xanthomonadaceae in Winter. We classified 33 % of ARG-containing contigs as putative plasmid sequences, indicating the high potential for resistome transmission. A limited number of ARGs were linked to putative phages. Our results suggest that this model river is a hotspot for AMR activity and transmission, and highlight the merit of deep sequencing for AMR discovery.

Metagenome-Assembled Genomes from Photo-Oxidized and Nonoxidized Oil-Degrading Marine Microcosms.

We performed deep metagenomic sequencing on hydrocarbon-degrading marine microcosms designed to experimentally determine the effect of photo-oxidation on oil biodegradation dynamics. Assembly, binning, and dereplication yielded 73 unique metagenome-assembled genomes (MAGs) from 6 phyla, of which 61 are predicted to be over 90% complete.

Herbivorous Fish Microbiome Adaptations to Sulfated Dietary Polysaccharides.

Marine herbivorous fish that feed primarily on macroalgae, such as those from the genus Kyphosus, are essential for maintaining coral health and abundance on tropical reefs. Here, deep metagenomic sequencing and assembly of gut compartment-specific samples from three sympatric, macroalgivorous Hawaiian kyphosid species have been used to connect host gut microbial taxa with predicted protein functional capacities likely to contribute to efficient macroalgal digestion. Bacterial community compositions, algal dietary sources, and predicted enzyme functionalities were analyzed in parallel for 16 metagenomes spanning the mid- and hindgut digestive regions of wild-caught fishes. Gene colocalization patterns of expanded carbohydrate (CAZy) and sulfatase (SulfAtlas) digestive enzyme families on assembled contigs were used to identify likely polysaccharide utilization locus associations and to visualize potential cooperative networks of extracellularly exported proteins targeting complex sulfated polysaccharides. These insights into the gut microbiota of herbivorous marine fish and their functional capabilities improve our understanding of the enzymes and microorganisms involved in digesting complex macroalgal sulfated polysaccharides. IMPORTANCE This work connects specific uncultured bacterial taxa with distinct polysaccharide digestion capabilities lacking in their marine vertebrate hosts, providing fresh insights into poorly understood processes for deconstructing complex sulfated polysaccharides and potential evolutionary mechanisms for microbial acquisition of expanded macroalgal utilization gene functions. Several thousand new marine-specific candidate enzyme sequences for polysaccharide utilization have been identified. These data provide foundational resources for future investigations into suppression of coral reef macroalgal overgrowth, fish host physiology, the use of macroalgal feedstocks in terrestrial and aquaculture animal feeds, and the bioconversion of macroalgae biomass into value-added commercial fuel and chemical products.

Apollo Rising: Acute Conjunctivitis Outbreak in India, 2022.

To identify pathogens associated with the 2022 conjunctivitis outbreak in Tamil Nadu, India. This prospective study was conducted in November of 2022. Patients with presumed acute infectious conjunctivitis presenting to the Aravind Eye Clinic in Madurai, India were eligible. Anterior nares and conjunctival samples from participants were obtained and processed for metagenomic RNA deep sequencing (RNA-seq). Samples from 29 patients were sequenced. A pathogen was identified in 28/29 (97%) patients. Coxsackievirus A24v, a highly infectious RNA virus, was the predominant pathogen and detected in 23/29 patients. Human adenovirus D (HAdV-D), a DNA virus commonly associated with conjunctivitis outbreaks, was detected in the remaining patients (5/29). Hemorrhagic conjunctiva was documented in both HAdV-D and coxsackievirus A24v affected patients but was not the predominant clinical presentation. Phylogenetic analysis of coxsackievirus A24v revealed a recent divergence from the 2015 outbreak. Coxsackievirus A24v and HAdV-D were co-circulating during the 2022 conjunctivitis outbreak in Tamil Nadu, India. Clinical findings were similar between patients with HAD-V and coxsackievirus A24v associated conjunctivitis. As high-throughput technologies become more readily accessible and cost-effective, unbiased pathogen surveillance may prove useful for outbreak surveillance and control.

Metagenomic Deep Sequencing for Orbital Inflammatory Disease

ABSTRACT Purpose Orbital inflammatory disease (OID) is a heterogeneous group of immunologic disorders whose etiology is often non-specific despite routine investigation. In this proof-of-concept study, metagenomic deep sequencing (MDS) is applied to examine host gene expression in two subtypes of OID. Methods Prospectively collected lacrimal gland tissue from patients with OID was processed for MDS. Differential gene expression analysis was performed to evaluate for host transcriptome signatures. Proof-of-concept comparison was made between histologically confirmed samples of idiopathic dacryoadenitis and IgG4-related disease (IgG4-RD). Results Twelve genes were identified to be differentially expressed between idiopathic dacryoadenitis and IgG4-RD. Differences in innate humoral immunity gene expression were observed. Several additional genes of interests were also found to be upregulated in idiopathic dacryoadenitis. Conclusions A unique transcriptome signature was found when comparing idiopathic dacryoadenitis to IgG4-RD. This suggests that MDS can identify differentially expressed genes in OID. Such insight could potentially provide a better understanding of host gene expression and the inflammatory pathways involved in OID.

An update on immunological and molecular tests and their impact in infectious uveitis.

Early diagnosis of infectious uveitis can lead to prompt initiation of treatment to minimize vision-threatening sequelae. As various infectious etiologies of uveitis share similar clinical features, advancements in polymerase chain reaction (PCR) and metagenomic next-generation sequencing (MDS) have shown significant promise in improving diagnostic capabilities. Various techniques of PCR, including real-time, multiplex, comprehensive, and broad-range, have increased the armamentarium for infectious uveitis diagnosis. Additionally, metagenomic deep sequencing technology has provided a methodology to identify causative pathogens as well as novel etiologies of uveitis. This review discusses the diagnostic tools available for infectious uveitis and highlights the advantages and disadvantages of the techniques.

Abstract 22: The Effects of Randomized Cocoa Extract and Multivitamins on the Gut Microbiome: A Pilot Study in COSMOS

Background: The COcoa Supplement and Multivitamin Outcomes Study (COSMOS) is a recently completed randomized, double-blind, placebo-controlled, 2x2 factorial trial of a multivitamin and cocoa extract supplement (containing 500 mg/d flavanols) in 21,442 older adults. In view of favorable effects of multivitamins on cognition and promising signals for cardiovascular risk reduction with cocoa extract, we conducted a pilot study to explore whether these interventions affected gut microbial composition and function. Methods: We conducted deep shotgun metagenomic sequencing in 30 COSMOS participants using fecal samples collected at baseline and year 2. We performed taxonomic profiling using MetaPhlAn2 and functional profiling using HUMAnN2. After proper quality filtering, we analyzed effects of both interventions on 2-year changes in microbial features, adjusting for age, sex, and body mass index. Results: Cocoa extract supplementation significantly altered the overall gut microbial taxonomic compositions from baseline to year 2, and explained 5.5% of the variance in the 2-year changes in relative abundance of all microbial species ( P =0.008). We further found that randomized cocoa extract supplementation altered the relative abundance of a few microbial species, including those previously linked to anti-inflammatory and cardiometabolic benefits (e.g., Akkermansia muciniphila , nominal P <0.05), and several microbial super pathways (including pyrimidine ribonucleotides de novo biosynthesis, FDR=0.03, and 28 other pathways with nominal P <0.05). Randomized multivitamin use did not significantly affect 2-year changes in alpha or beta diversity, but altered the abundance a few putative bacterial species and functional pathways (nominal P <0.05). Summary: Our pilot study suggests that cocoa extract and multivitamin supplementation in COSMOS may alter the gut microbiome and influence pathways relevant to health, emphasizing the need for larger studies that allow for more detailed investigations.

Targeting the gut-lung axis by synbiotic feeding to infants in a randomized controlled trial

BackgroundFormula-fed infants are at increased risk of infections. Due to the cross-talk between the mucosal systems of the gastrointestinal and respiratory tracts, adding synbiotics (prebiotics and probiotics) to infant formula may prevent infections even at distant sites. Infants that were born full term and weaned from breast milk were randomized to prebiotic formula (fructo- and galactooligosaccharides) or the same prebiotic formula with Lactobacillus paracasei ssp. paracasei F19 (synbiotics) from 1 to 6 months of age. The objective was to examine the synbiotic effects on gut microbiota development.ResultsFecal samples collected at ages 1, 4, 6, and 12 months were analyzed using 16S rRNA gene sequencing and a combination of untargeted gas chromatography-mass spectrometry/liquid chromatography-mass spectrometry. These analyses revealed that the synbiotic group had a lower abundance of Klebsiella, a higher abundance of Bifidobacterium breve compared to the prebiotic group, and increases in the anti-microbial metabolite d-3-phenyllactic acid. We also analyzed the fecal metagenome and antibiotic resistome in the 11 infants that had been diagnosed with lower respiratory tract infection (cases) and 11 matched controls using deep metagenomic sequencing. Cases with lower respiratory tract infection had a higher abundance of Klebsiella species and antimicrobial resistance genes related to Klebsiella pneumoniae, compared to controls. The results obtained using 16S rRNA gene amplicon and metagenomic sequencing were confirmed in silico by successful recovery of the metagenome-assembled genomes of the bacteria of interest.ConclusionsThis study demonstrates the additional benefit of feeding specific synbiotics to formula-fed infants over prebiotics only. Synbiotic feeding led to the underrepresentation of Klebsiella, enrichment of bifidobacteria, and increases in microbial degradation metabolites implicated in immune signaling and in the gut-lung and gut-skin axes. Our findings support future clinical evaluation of synbiotic formula in the prevention of infections and associated antibiotic treatment as a primary outcome when breastfeeding is not feasible.Trial registrationClinicalTrials.gov NCT01625273. Retrospectively registered on 21 June 2012.

Cross-generational bacterial strain transfer to an infant after fecal microbiota transplantation to a pregnant patient: a case report

BackgroundFecal microbiota transplantation (FMT) effectively prevents the recurrence of Clostridioides difficile infection (CDI). Long-term engraftment of donor-specific microbial consortia may occur in the recipient, but potential further transfer to other sites, including the vertical transmission of donor-specific strains to future generations, has not been investigated. Here, we report, for the first time, the cross-generational transmission of specific bacterial strains from an FMT donor to a pregnant patient with CDI and further to her child, born at term, 26 weeks after the FMT treatment.MethodsA pregnant woman (gestation week 12 + 5) with CDI was treated with FMT via colonoscopy. She gave vaginal birth at term to a healthy baby. Fecal samples were collected from the feces donor, the mother (before FMT, and 1, 8, 15, 22, 26, and 50 weeks after FMT), and the infant (meconium at birth and 3 and 6 months after birth). Fecal samples were profiled by deep metagenomic sequencing for strain-level analysis. The microbial transfer was monitored using single nucleotide variants in metagenomes and further compared to a collection of metagenomic samples from 651 healthy infants and 58 healthy adults.ResultsThe single FMT procedure led to an uneventful and sustained clinical resolution in the patient, who experienced no further CDI-related symptoms up to 50 weeks after treatment. The gut microbiota of the patient with CDI differed considerably from the healthy donor and was characterized as low in alpha diversity and enriched for several potential pathogens. The FMT successfully normalized the patient’s gut microbiota, likely by donor microbiota transfer and engraftment. Importantly, our analysis revealed that some specific strains were transferred from the donor to the patient and then further to the infant, thus demonstrating cross-generational microbial transfer.ConclusionsThe evidence for cross-generational strain transfer following FMT provides novel insights into the dynamics and engraftment of bacterial strains from healthy donors. The data suggests FMT treatment of pregnant women as a potential strategy to introduce beneficial strains or even bacterial consortia to infants, i.e., neonatal seeding.-DXaTv5TzCLMh4Fzww-k9DVideo

Metagenomic Features Characterized with Microbial Iron Oxidoreduction and Mineral Interaction in Southwest Indian Ridge.

The Southwest Indian Ridge (SWIR) is one of the typical representatives of deep-sea ultraslow-spreading ridges, and has increasingly become a hot spot of studying subsurface geological activities and deep-sea mining management. However, the understanding of microbial activities is still limited on active hydrothermal vent chimneys in SWIR. In this study, samples from an active black smoker and a diffuse vent located in the Longqi hydrothermal region were collected for deep metagenomic sequencing, which yielded approximately 290 GB clean data and 295 mid-to-high-quality metagenome-assembled genomes (MAGs). Sulfur oxidation conducted by a variety of Gammaproteobacteria, Alphaproteobacteria, and Campylobacterota was presumed to be the major energy source for chemosynthesis in Longqi hydrothermal vents. Diverse iron-related microorganisms were recovered, including iron-oxidizing Zetaproteobacteria, iron-reducing Deferrisoma, and magnetotactic bacterium. Twenty-two bacterial MAGs from 12 uncultured phyla harbored iron oxidase Cyc2 homologs and enzymes for organic carbon degradation, indicated novel chemolithoheterotrophic iron-oxidizing bacteria that affected iron biogeochemistry in hydrothermal vents. Meanwhile, potential interactions between microbial communities and chimney minerals were emphasized as enriched metabolic potential of siderophore transportation, and extracellular electron transfer functioned by multi-heme proteins was discovered. Composition of chimney minerals probably affected microbial iron metabolic potential, as pyrrhotite might provide more available iron for microbial communities. Collectively, this study provides novel insights into microbial activities and potential mineral-microorganism interactions in hydrothermal vents. IMPORTANCE Microbial activities and interactions with minerals and venting fluid in active hydrothermal vents remain unclear in the ultraslow-spreading SWIR (Southwest Indian Ridge). Understanding about how minerals influence microbial metabolism is currently limited given the obstacles in cultivating microorganisms with sulfur or iron oxidoreduction functions. Here, comprehensive descriptions on microbial composition and metabolic profile on 2 hydrothermal vents in SWIR were obtained based on cultivation-free metagenome sequencing. In particular, autotrophic sulfur oxidation supported by minerals was presumed, emphasizing the role of chimney minerals in supporting chemosynthesis. Presence of novel heterotrophic iron-oxidizing bacteria was also indicated, suggesting overlooked biogeochemical pathways directed by microorganisms that connected sulfide mineral dissolution and organic carbon degradation in hydrothermal vents. Our findings offer novel insights into microbial function and biotic interactions on minerals in ultraslow-spreading ridges.

Deep sequencing analysis of clinical samples from patients with acute infectious conjunctivitis during the COVID-19 delta surge in Madurai, India.

BackgroundSeasonal outbreaks of infectious conjunctivitis remain a public health issue. Determination of outbreak etiologies in the context of a worldwide pandemic may provide useful information to guide public health strategies. The aim of this study was to identify pathogens associated with outpatient infectious conjunctivitis during the COVID-19 Delta surge.MethodsThis prospective study was conducted from April 2021 to September 2021. All outpatients presenting to the Aravind Eye Center (Madurai, India) with signs and symptoms consistent with acute infectious conjunctivitis were eligible. Three swabs were obtained from each participant: one from each conjunctiva and one from the anterior nares. Samples were processed for metagenomic RNA deep sequencing (RNA-seq).ResultsSamples from 106 study participants were sequenced. The most common presenting symptoms were tearing (86%) and itching (71%). Preauricular lymphadenopathy was present in 38% of participants. 20% of participants had close contacts with similar symptoms. Systemic symptoms such as coughing, runny nose, vomiting or diarrhea were uncommonly reported. 60% of all participants used some medicated eye drops upon enrollment. 75% of study participants demonstrated infection with human adenovirus D (HAdV-D). 11% of conjunctivitis was associated with SARS-CoV-2. 15% had no definitive pathogen detected. 8% of all participants had codetection of more than one pathogen on RNA-seq.ConclusionsDuring the COVID-19 Delta surge in India, HAdV-D was the most common pathogen associated with infectious conjunctivitis. SARS-CoV-2 was the second most common etiology. Seasonal surveillance may be necessary for the determination of emerging and reemerging pathogens responsible for infectious conjunctivitis.

Outpatient human coronavirus associated conjunctivitis in India.

BackgroundViral conjunctivitis (pink eye) can be highly contagious and is of public health importance. There remains significant debate whether SARS-CoV-2 can present as a primary conjunctivitis. The aim of this study was to identify pathogens associated with outpatient infectious conjunctivitis during the COVID-19 Delta surge.MethodsThis prospective study was conducted in the spring and summer months of 2021. 106 patients with acute conjunctivitis who presented to the Aravind Eye Center in Madurai, India were included. One anterior nasal swab and one conjunctival swab of each eye were obtained for each enrolled patient. Samples were subsequently processed for unbiased metagenomic RNA deep sequencing (RNA-seq). Outcomes included clinical findings and codetection of other pathogens with SARS-COV-2 in patients with conjunctivitis.ResultsAmong the 13 patients identified with human coronavirus RNA fragments in their swabs, 6 patients had SARS-COV-2 infection, 5 patients had coinfections of SARS-CoV-2 and human adenovirus (HAdV), 1 patient had a coinfection with human coronavirus OC43 and HAdV, and 1 patient had a coinfection of Vittaforma corneae and SARS-CoV-2. 30% had bilateral disease and symptoms on presentation. Petechial hemorrhage was noted in 33% of patients with SARS-COV-2 infection. No patients with SARS-CoV-2 or SARS-CoV-2 and HAdV infections had subepithelial infiltrates on presentation. All patients denied systemic symptoms.ConclusionsAmong the patients presented with conjunctivitis associated with human coronavirus infection, over 50% of the patients had co-infections with other circulating pathogens, suggesting the public-health importance of broad pathogen testing and surveillance in the outpatient conjunctivitis population.

Shallow shotgun sequencing of the microbiome recapitulates 16S amplicon results and provides functional insights.

Prevailing 16S rRNA gene-amplicon methods for characterizing the bacterial microbiome of wildlife are economical, but result in coarse taxonomic classifications, are subject to primer and 16S copy number biases, and do not allow for direct estimation of microbiome functional potential. While deep shotgun metagenomic sequencing can overcome many of these limitations, it is prohibitively expensive for large sample sets. Here we evaluated the ability of shallow shotgun metagenomic sequencing to characterize taxonomic and functional patterns in the faecal microbiome of a model population of feral horses (Sable Island, Canada). Since 2007, this unmanaged population has been the subject of an individual-based, long-term ecological study. Using deep shotgun metagenomic sequencing, we determined the sequencing depth required to accurately characterize the horse microbiome. In comparing conventional vs. high-throughput shotgun metagenomic library preparation techniques, we validate the use of more cost-effective laboratory methods. Finally, we characterize similarities between 16S amplicon and shallow shotgun characterization of the microbiome, and demonstrate that the latter recapitulates biological patterns first described in a published amplicon data set. Unlike for amplicon data, we further demonstrate how shallow shotgun metagenomic data provide useful insights regarding microbiome functional potential which support previously hypothesized diet effects in this study system.

An online atlas of human plasma metabolite signatures of gut microbiome composition

Human gut microbiota produce a variety of molecules, some of which enter the bloodstream and impact health. Conversely, dietary or pharmacological compounds may affect the microbiota before entering the circulation. Characterization of these interactions is an important step towards understanding the effects of the gut microbiota on health. In this cross-sectional study, we used deep metagenomic sequencing and ultra-high-performance liquid chromatography linked to mass spectrometry for a detailed characterization of the gut microbiota and plasma metabolome, respectively, of 8583 participants invited at age 50 to 64 from the population-based Swedish CArdioPulmonary bioImage Study. Here, we find that the gut microbiota explain up to 46% of the variance of individual plasma metabolites and we present 997 associations between alpha diversity and plasma metabolites and 546,819 associations between specific gut metagenomic species and plasma metabolites in an online atlas (https://gutsyatlas.serve.scilifelab.se/). We exemplify the potential of this resource by presenting novel associations between dietary factors and oral medication with the gut microbiome, and microbial species strongly associated with the uremic toxin p-cresol sulfate. This resource can be used as the basis for targeted studies of perturbation of specific metabolites and for identification of candidate plasma biomarkers of gut microbiota composition.