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Microbiology (Reading, England) Jun 2024Metagenome community analyses, driven by the continued development in sequencing technology, is rapidly providing insights in many aspects of microbiology and becoming a...
Metagenome community analyses, driven by the continued development in sequencing technology, is rapidly providing insights in many aspects of microbiology and becoming a cornerstone tool. Illumina, Oxford Nanopore Technologies (ONT) and Pacific Biosciences (PacBio) are the leading technologies, each with their own advantages and drawbacks. Illumina provides accurate reads at a low cost, but their length is too short to close bacterial genomes. Long reads overcome this limitation, but these technologies produce reads with lower accuracy (ONT) or with lower throughput (PacBio high-fidelity reads). In a critical first analysis step, reads are assembled to reconstruct genomes or individual genes within the community. However, to date, the performance of existing assemblers has never been challenged with a complex mock metagenome. Here, we evaluate the performance of current assemblers that use short, long or both read types on a complex mock metagenome consisting of 227 bacterial strains with varying degrees of relatedness. We show that many of the current assemblers are not suited to handle such a complex metagenome. In addition, hybrid assemblies do not fulfil their potential. We conclude that ONT reads assembled with CANU and Illumina reads assembled with SPAdes offer the best value for reconstructing genomes and individual genes of complex metagenomes, respectively.
Topics: Metagenome; Benchmarking; High-Throughput Nucleotide Sequencing; Metagenomics; Bacteria; Sequence Analysis, DNA; Genome, Bacterial; Microbiota
PubMed: 38916949
DOI: 10.1099/mic.0.001469 -
Microbiology Spectrum Jun 2024Metagenomic next-generation sequencing (mNGS) is an unbiased and rapid method for detecting pathogens. This study enrolled 145 suspected severe pneumonia patients who...
Metagenomic next-generation sequencing (mNGS) is an unbiased and rapid method for detecting pathogens. This study enrolled 145 suspected severe pneumonia patients who were admitted to the Affiliated Hospital of Jining Medical University. This study primarily aimed to determine the diagnostic performance of mNGS and conventional microbiological tests (CMTs) using bronchoalveolar lavage fluid samples for detecting pathogens. Our findings indicated that mNGS performed significantly higher sensitivity (97.54% vs 28.68%, < 0.001), coincidence (90.34% vs 35.17%, < 0.001), and negative predictive value (80.00% vs 13.21%, < 0.001) but performed lower specificity than CMTs (52.17% vs 87.5%, < 0.001). as the most common bacterial pathogen had the largest proportion (22.90%, 30/131) in this study. In addition to bacteria, fungi, and virus, mNGS can detect a variety of atypical pathogens such as and . Mixed infections were common in patients with severe pneumonia, and bacterial-fungal-viral-atypical pathogens were the most complicated infection. After adjustments of antibiotics based on mNGS and CMTs, the clinical manifestation improved in 139 (95.86%, 139/145) patients. Our data demonstrated that mNGS had significant advantage in diagnosing respiratory tract infections, especially atypical pathogens and fungal infections. Pathogens were detected timely and comprehensively, contributing to the adjustments of antibiotic treatments timely and accurately, improving patient prognosis and decreasing mortality potentially.IMPORTANCEMetagenomic next-generation sequencing using bronchoalveolar lavage fluid can provide more comprehensive and accurate pathogens for respiratory tract infections, especially when considering the previous usage of empirical antibiotics before admission or complicated clinical presentation. This technology is expected to play an important role in the precise application of antimicrobial drugs in the future.
PubMed: 38916357
DOI: 10.1128/spectrum.00458-24 -
Microbiology Spectrum Jun 2024From May to July of 2023, one pig farm in Heyuan city, Guangdong Province of China, suffered severe piglet death and sow reproductive disorders. The common pig viruses...
From May to July of 2023, one pig farm in Heyuan city, Guangdong Province of China, suffered severe piglet death and sow reproductive disorders. The common pig viruses and bacteria tested negative. To uncover the possible cause of the disease, a metagenomic analysis was performed in the pooled small intestine samples from three 8-day-old diseased piglets. The results showed that Getah virus (GETV), an RNA virus, might be the potential pathogen that affects pig health. Subsequently, GETV nucleotide was detected in all of the 15 samples collected from three diseased piglets using quantitative reverse transcription PCR, suggesting GETV as the main pathogen of the disease. A GETV strain, designated as GDHYLC23, was successfully isolated using the swine testicle cell line. Sequence analysis showed that the epidemic strain had a unique 32-nucleotide repeat insertion in the 3' noncoding region. Phylogenetic analysis showed that GDHYLC23 belonged to the pandemic group III. The identification of GETV with new variations implies the continuous evolution of the virus, which poses potential threats to the swine industry.IMPORTANCEPig farms are faced with emerging and re-emerging viruses that may cause substantial economic loss. The identification of potentially pathogenic viruses helps to prevent and control the spread of diseases. In this study, by using metagenomic analysis, we found that a neglected virus, GETV with a unique insertion in the genome, was the main pathogen in one pig farm that suffered severe piglet death and sow reproductive disorders. Although the potential impact of such an insertion on viral pathogenicity is unknown, the surveillance of the continuing evolution of GETV in pig farms cannot be ignored.
PubMed: 38916356
DOI: 10.1128/spectrum.00483-24 -
Microbiology Spectrum Jun 2024This study aimed to investigate the presence of antimicrobial resistance determinants (ARDs) in the Neanderthal microbiome through meticulous analysis of metagenomic...
UNLABELLED
This study aimed to investigate the presence of antimicrobial resistance determinants (ARDs) in the Neanderthal microbiome through meticulous analysis of metagenomic data derived directly from dental calculus and fecal sediments across diverse Neanderthal sites in Europe. Employing a targeted locus mapping approach followed by a consensus strategy instead of an assembly-first approach, we aimed to identify and characterize ARDs within these ancient microbial communities. A comprehensive and redundant ARD database was constructed by amalgamating data from various antibiotic resistance gene repositories. Our results highlighted the efficacy of the KMA tool in providing a robust alignment of ancient metagenomic reads to the antibiotic resistance gene database. Notably, the KMA tool identified a limited number of ARDs, with only the 23S ribosomal gene from the dental calculus sample of Neanderthal remains at Goyet Troisieme Caverne exhibiting ancient DNA (aDNA) characteristics. Despite not identifying ARDs with typical ancient DNA damage patterns or negative distance proportions, our findings suggest a nuanced identification of putative antimicrobial resistance determinants in the Neanderthal microbiome's genetic repertoire based on the taxonomy-habitat correlation. Nevertheless, our findings are limited by factors such as environmental DNA contamination, DNA fragmentation, and cytosine deamination of aDNA. The study underscores the necessity for refined methodologies to unlock the genomic assets of prehistoric populations, fostering a comprehensive understanding of the intricate dynamics shaping the microbial landscape across history.
IMPORTANCE
The results of our analysis demonstrate the challenges in identifying determinants of antibiotic resistance within the endogenous microbiome of Neanderthals. Despite the comprehensive investigation of multiple studies and the utilization of advanced analytical techniques, the detection of antibiotic resistance determinants in the ancient microbial communities proved to be particularly difficult. However, our analysis did reveal the presence of some authentic ancient conservative genes, indicating the preservation of certain genetic elements over time. These findings raise intriguing questions about the factors influencing the presence or absence of antibiotic resistance in ancient microbial communities. It could be speculated that the spread of current antibiotic resistance, which has reached alarming levels in modern times, is primarily driven by anthropogenic factors such as the widespread use and misuse of antibiotics in medical and agricultural practices.
PubMed: 38916350
DOI: 10.1128/spectrum.02662-23 -
Microbiology Spectrum Jun 2024In recent years, most studies on the gut microbiome have primarily focused on feces samples, leaving the microbial communities in the intestinal mucosa relatively...
UNLABELLED
In recent years, most studies on the gut microbiome have primarily focused on feces samples, leaving the microbial communities in the intestinal mucosa relatively unexplored. To address this gap, our study employed shotgun metagenomics to analyze the microbial compositions in normal rectal mucosa and matched feces from 20 patients with colonic polyps. Our findings revealed a pronounced distinction of the microbial communities between these two sample sets. Compared with feces, the mucosal microbiome contains fewer genera, with Burkholderia being the most discriminating genus between feces and mucosa, highlighting its significant influence on the mucosa. Furthermore, based on the microbial classification and KEGG Orthology (KO) annotation results, we explored the association between rectal mucosal microbiota and factors such as age, gender, BMI, and polyp risk level. Notably, we identified novel biomarkers for these phenotypes, such as and in age. The mucosal microbiota showed an enrichment of KO pathways related to sugar transport and short chain fatty acid metabolism. Our comprehensive approach not only bridges the knowledge gap regarding the microbial community in the rectal mucosa but also underscores the complexity and specificity of microbial interactions within the human gut, particularly in the Chinese population.
IMPORTANCE
This study presents a system-level map of the differences between feces and rectal mucosal microbial communities in samples with colorectal cancer risk. It reveals the unique microecological characteristics of rectal mucosa and its potential influence on health. Additionally, it provides novel insights into the role of the gut microbiome in the pathogenesis of colorectal cancer and paves the way for the development of new prevention and treatment strategies.
PubMed: 38916335
DOI: 10.1128/spectrum.03549-23 -
Microbiology Spectrum Jun 2024Gut bacteria belonging to the family play a pivotal role in regulating host energy balance and metabolic homeostasis. As a commensal bacterium, has been implicated in...
UNLABELLED
Gut bacteria belonging to the family play a pivotal role in regulating host energy balance and metabolic homeostasis. As a commensal bacterium, has been implicated in modulating host energy homeostasis, albeit the underlying mechanism remains elusive. Therefore, this study aimed to investigate the impact of supplementation on various physiological parameters, intestinal morphology, particularly adipose tissue accumulation, and glucolipid metabolism in mice. The findings reveal that mice supplemented with for 6 weeks exhibited a notable increase in body weight, fat mass, adipocyte size, and serum triglyceride (TG) levels. Notably, the increased fat accumulation is observed despite consistent feed intake in treated mice. Mechanistically, supplementation significantly improved the structure integrity of intestinal villi and enhanced energy absorption efficiency while reducing excretion of carbohydrates and fatty acids in feces. This was accompanied by upregulation of glucose and fatty acid transporter expression. Furthermore, supplementation with promoted adipogenesis in both liver and adipose tissues, as evidenced by increased levels of hepatic pyruvate, acetyl-CoA, and TG, along with elevated expression levels of genes associated with lipid synthesis. Regarding the microbiological aspect, supplementation correlated with an increased abundance of genus bacteria and enhanced carbohydrate enzyme activity. In summary, supplementation significantly promotes fat accumulation in mice by augmenting energy absorption and adipogenesis, possibly mediated by the expansion of bacteria population with robust glycolipid metabolic ability.
IMPORTANCE
The clusters have been implicated in energy metabolism, the specific species and underlying mechanisms remain unclear. This present study is the first to report is able to affect fat accumulation and glycolipid metabolism. We indicated that gavage of promoted the adipogenesis and fat accumulation in mice by not only increasing the abundance of bacteria but by also enhancing the metabolic absorption of carbohydrates and fatty acids significantly. Obviously, changes of gut microbiota caused by the , especially the significant increase of bacteria, contributed to the fat accumulation of mice. In addition, the enhancement of genus bacteria remarkably improved the synthesis of hepatic pyruvate, acetyl-CoA, and triglyceride levels, as well as reduced the excretion of fecal carbohydrates, short-chain fatty acids, and free fatty acids remarkably. These findings will help us to understand the relationship of specific bacteria and host energy homeostasis.
PubMed: 38916334
DOI: 10.1128/spectrum.04116-23 -
Microbiology Spectrum Jun 2024Little is known about the urinary virome and how it interacts with the host, particularly in renal transplant diseases. Using metagenomic sequencing, we characterized...
UNLABELLED
Little is known about the urinary virome and how it interacts with the host, particularly in renal transplant diseases. Using metagenomic sequencing, we characterized the urinary virome of 23 kidney transplant recipients longitudinally (11 BKV+ patients and 12 BKV- patients). We applied linear mixed effects models, PERMANOVA, k-means clustering, and MaAsLin2 algorithms to determine virome signatures associated with post-transplant time, BK viremia status, and patient sex. We found that the richness and alpha diversity of urinary virome were significantly different in renal transplant recipients with BKV+ over time in comparison to BKV- (richness = 0.012, alpha < 0.0001). Female BKV- patients had significantly higher virome richness than males ( = 0.0063). Virome beta diversity was significantly different between patients by BKV status ( < 0.001). Additionally, we identified underlying interactions between patient sex and BKV status, in terms of virome beta diversity ( = 0.008). BK polyomavirus infections were primarily of subtypes IA, IB1, and IB2. The non-BK dominant samples clustered into six urinary virome community states. BKV- samples had more anelloviruses than BKV+ samples though this difference was not statistically significant. Lastly, we identified specific viruses, associated with BKV+ and time in our samples. Our results indicate that dynamic alterations in the urinary virome over the post-transplant period in kidney transplant recipients can be shaped by BK viremia and patient sex. These findings advance our fundamental understanding of the urinary virome and support a new line of investigation in renal disease and transplantation.
IMPORTANCE
The urinary microbiome is increasingly implicated in renal health and disease. While most research focuses on bacteria communities of the microbiome, factors that influence the urinary virome are not understood. Here, we investigated the urinary virome of 23 adult kidney transplant recipients longitudinally over 14 weeks post-transplant. We show that alterations in the urinary virome are associated with kidney transplant recipients with BK polyomavirus viremia that can lead to BK nephropathy and allograft rejection. By modeling the temporal dynamics post-transplant, we delineated specific profiles of the urinary virome associated with patient sex and urinary community states. These findings reveal fundamental aspects of the urinary virome that can be leveraged to better manage kidney diseases.
PubMed: 38916313
DOI: 10.1128/spectrum.04055-23 -
Microbiology Resource Announcements Jun 2024This study reports a circular metagenome-assembled genome (cMAG) of Cloacimonadota recovered from a mesophilic full-scale food waste treatment plant. The cMAG spans...
This study reports a circular metagenome-assembled genome (cMAG) of Cloacimonadota recovered from a mesophilic full-scale food waste treatment plant. The cMAG spans 2,298,113 bp, with 980× coverage and 1 contig.
PubMed: 38916296
DOI: 10.1128/mra.00403-24 -
The ISME Journal Jun 2024Diazotrophic microorganisms regulate marine productivity by alleviating nitrogen limitation. So far chemolithoautotrophic bacteria are widely recognized as the principal...
Diazotrophic microorganisms regulate marine productivity by alleviating nitrogen limitation. So far chemolithoautotrophic bacteria are widely recognized as the principal diazotrophs in oligotrophic marine and terrestrial ecosystems. However, the contribution of chemolithoautotrophs to nitrogen fixation in organic-rich habitats remains unclear. Here, we utilized metagenomic and metatranscriptomic approaches integrated with cultivation assays to investigate the diversity, distribution, and activity of diazotrophs residing in Zhangzhou mangrove sediments. Physicochemical assays show that the studied mangrove sediments are typical carbon-rich, sulfur-rich, nitrogen-limited, and low-redox marine ecosystems. These sediments host a wide phylogenetic variety of nitrogenase genes, including groups I-III and VII-VIII. Unexpectedly diverse chemolithoautotrophic taxa including Campylobacteria, Gammaproteobacteria, Zetaproteobacteria, and Thermodesulfovibrionia are the predominant and active nitrogen fixers in the 0-18 cm sediment layer. In contrast, the 18-20 cm layer is dominated by active diazotrophs from the chemolithoautotrophic taxa Desulfobacterota and Halobacteriota. Further analysis of MAGs show that the main chemolithoautotrophs can fix nitrogen by coupling the oxidation of hydrogen, reduced sulfur, and iron, with the reduction of oxygen, nitrate, and sulfur. Culture experiments further demonstrate that members of chemolithoautotrophic Campylobacteria have the nitrogen-fixing capacity driven by hydrogen and sulfur oxidation. Activity measurements confirm that the diazotrophs inhabiting mangrove sediments preferentially drain energy from diverse reduced inorganic compounds other than from organics. Overall, our results suggest that chemolithoautotrophs rather than heterotrophs are dominant nitrogen fixers in mangrove sediments. This study underscores the significance of chemolithoautotrophs in carbon-dominant ecosystems.
PubMed: 38916247
DOI: 10.1093/ismejo/wrae119 -
Frontiers in Cellular and Infection... 2024Mucormycosis is an uncommon invasive fungal infection that has a high mortality rate in patients with severe underlying diseases, which leads to immunosuppression. Due...
BACKGROUND
Mucormycosis is an uncommon invasive fungal infection that has a high mortality rate in patients with severe underlying diseases, which leads to immunosuppression. Due to its rarity, determining the incidence and optimal treatment methods for mucormycosis in children is challenging. Metagenomic next-generation sequencing (mNGS) is a rapid, precise and sensitive method for pathogen detection, which helps in the early diagnosis and intervention of mucormycosis in children. In order to increase pediatricians' understanding of this disease, we conducted a study on the clinical features of mucormycosis in children and assessed the role of mNGS in its diagnosis.
METHODS
We retrospectively summarized the clinical data of 14 children with mucormycosis treated at the First Affiliated Hospital of Zhengzhou University from January 2020 to September 2023.
RESULTS
Of the 14 cases, 11 case of mucormycosis were classified as probable, and 3 cases were proven as mucormycosis. Most children (85.71%) had high-risk factors for mucormycosis. All 14 children had lung involvement, with 5 cases of extrapulmonary dissemination. Among the 14 cases, 4 cases underwent histopathological examination of mediastinum, lung tissue or kidney tissue, in which fungal pathogens were identified in 3 patients. Fungal hyphae was identified in 3 cases of mucormycosis, but only 1 case yielded a positive culture result. All patients underwent mNGS testing with samples from blood (8/14), bronchoalveolar lavage fluid (6/14), and tissue (1/14). mNGS detected fungi in all cases: 7 cases had , 4 cases had , 3 cases had , 1 case had , and 1 case had . Coinfections were found with in 3 cases, bacteria in 3 cases, and viruses in 5 cases.
CONCLUSION
Children with mucormycosis commonly exhibit non-specific symptoms like fever and cough during the initial stages. Early diagnosis based on clinical symptoms and imaging is crucial in children suspected of having mucormycosis. mNGS, as a supplementary diagnostic method, offers greater sensitivity and shorter detection time compared to traditional mucormycosis culture or histopathological testing. Additionally, mNGS enables simultaneous detection of bacteria and viruses, facilitating timely and appropriate administration of antibiotics and thereby enhancing patient outcomes.
Topics: Humans; Mucormycosis; High-Throughput Nucleotide Sequencing; Male; Female; Child; Child, Preschool; Metagenomics; Retrospective Studies; Infant; Adolescent; Invasive Fungal Infections; China
PubMed: 38915923
DOI: 10.3389/fcimb.2024.1368165