1
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Trueba G, Cardenas P, Romo G, Gutierrez B. Reevaluating human-microbiota symbiosis: Strain-level insights and evolutionary perspectives across animal species. Biosystems 2024; 244:105283. [PMID: 39103138 DOI: 10.1016/j.biosystems.2024.105283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2024] [Revised: 08/01/2024] [Accepted: 08/02/2024] [Indexed: 08/07/2024]
Abstract
The prevailing consensus in scientific literature underscores the mutualistic bond between the microbiota and the human host, suggesting a finely tuned coevolutionary partnership that enhances the fitness of both parties. This symbiotic relationship has been extensively studied, with certain bacterial attributes being construed as hallmarks of natural selection favoring the benefit of the human host. Some scholars go as far as equating the intricate interplay between humans and their intestinal microbiota to that of endosymbiotic relationships, even conceptualizing microbiota as an integral human organ. However, amidst the prevailing narrative of bacterial species being categorized as beneficial or detrimental to human health, a critical oversight often emerges - the inherent functional diversity within bacterial strains. Such reductionist perspectives risk oversimplifying the complex dynamics at play within the microbiome. Recent genomic analysis at the strain level is highly limited, which is surprising given that strain information provides critical data about selective pressures in the intestine. These pressures appear to focus more on the well-being of bacteria rather than human health. Connected to this is the extent to which animals depend on metabolic activity from intestinal bacteria, which varies widely across species. While omnivores like humans exhibit lower dependency, certain herbivores rely entirely on bacterial activity and have developed specialized compartments to house these bacteria.
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Affiliation(s)
- Gabriel Trueba
- Instituto de Microbiología, Colegio de Ciencias Biológicas y Ambientales, Universidad San Francisco de Quito, Quito, Ecuador.
| | - Paul Cardenas
- Instituto de Microbiología, Colegio de Ciencias Biológicas y Ambientales, Universidad San Francisco de Quito, Quito, Ecuador
| | - German Romo
- Escuela de Medicina Veterinaria, Universidad San Francisco de Quito, Quito, Ecuador
| | - Bernardo Gutierrez
- Laboratorio de Biotecnología Vegetal, Colegio de Ciencias Biológicas y Ambientales, Universidad San Francisco de Quito, Quito, Ecuador; Department of Biology, University of Oxford, Oxford, OX1 3SZ, UK
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2
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Yi X, Liang JL, Wen P, Jia P, Feng SW, Liu SY, Zhuang YY, Guo YQ, Lu JL, Zhong SJ, Liao B, Wang Z, Shu WS, Li JT. Giant viruses as reservoirs of antibiotic resistance genes. Nat Commun 2024; 15:7536. [PMID: 39214976 PMCID: PMC11364636 DOI: 10.1038/s41467-024-51936-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Accepted: 08/21/2024] [Indexed: 09/04/2024] Open
Abstract
Nucleocytoplasmic large DNA viruses (NCLDVs; also called giant viruses), constituting the phylum Nucleocytoviricota, can infect a wide range of eukaryotes and exchange genetic material with not only their hosts but also prokaryotes and phages. A few NCLDVs were reported to encode genes conferring resistance to beta‑lactam, trimethoprim, or pyrimethamine, suggesting that they are potential vehicles for the transmission of antibiotic resistance genes (ARGs) in the biome. However, the incidence of ARGs across the phylum Nucleocytoviricota, their evolutionary characteristics, their dissemination potential, and their association with virulence factors remain unexplored. Here, we systematically investigated ARGs of 1416 NCLDV genomes including those of almost all currently available cultured isolates and high-quality metagenome-assembled genomes from diverse habitats across the globe. We reveal that 39.5% of them carry ARGs, which is approximately 37 times higher than that for phage genomes. A total of 12 ARG types are encoded by NCLDVs. Phylogenies of the three most abundant NCLDV-encoded ARGs hint that NCLDVs acquire ARGs from not only eukaryotes but also prokaryotes and phages. Two NCLDV-encoded trimethoprim resistance genes are demonstrated to confer trimethoprim resistance in Escherichia coli. The presence of ARGs in NCLDV genomes is significantly correlated with mobile genetic elements and virulence factors.
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Affiliation(s)
- Xinzhu Yi
- Institute of Ecological Science, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, PR China
| | - Jie-Liang Liang
- Institute of Ecological Science, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, PR China
| | - Ping Wen
- Institute of Ecological Science, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, PR China
| | - Pu Jia
- Institute of Ecological Science, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, PR China
| | - Shi-Wei Feng
- Institute of Ecological Science, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, PR China
| | - Shen-Yan Liu
- Institute of Ecological Science, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, PR China
| | - Yuan-Yue Zhuang
- Institute of Ecological Science, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, PR China
| | - Yu-Qian Guo
- Institute of Ecological Science, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, PR China
| | - Jing-Li Lu
- Institute of Ecological Science, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, PR China
| | - Sheng-Ji Zhong
- Institute of Ecological Science, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, PR China
| | - Bin Liao
- School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China
| | - Zhang Wang
- Institute of Ecological Science, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, PR China
| | - Wen-Sheng Shu
- Institute of Ecological Science, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, PR China
| | - Jin-Tian Li
- Institute of Ecological Science, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, PR China.
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3
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Wang S, Jiang Y, Che L, Wang RH, Li SC. Enhancing insights into diseases through horizontal gene transfer event detection from gut microbiome. Nucleic Acids Res 2024; 52:e61. [PMID: 38884260 DOI: 10.1093/nar/gkae515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 04/23/2024] [Accepted: 06/04/2024] [Indexed: 06/18/2024] Open
Abstract
Horizontal gene transfer (HGT) phenomena pervade the gut microbiome and significantly impact human health. Yet, no current method can accurately identify complete HGT events, including the transferred sequence and the associated deletion and insertion breakpoints from shotgun metagenomic data. Here, we develop LocalHGT, which facilitates the reliable and swift detection of complete HGT events from shotgun metagenomic data, delivering an accuracy of 99.4%-verified by Nanopore data-across 200 gut microbiome samples, and achieving an average F1 score of 0.99 on 100 simulated data. LocalHGT enables a systematic characterization of HGT events within the human gut microbiome across 2098 samples, revealing that multiple recipient genome sites can become targets of a transferred sequence, microhomology is enriched in HGT breakpoint junctions (P-value = 3.3e-58), and HGTs can function as host-specific fingerprints indicated by the significantly higher HGT similarity of intra-personal temporal samples than inter-personal samples (P-value = 4.3e-303). Crucially, HGTs showed potential contributions to colorectal cancer (CRC) and acute diarrhoea, as evidenced by the enrichment of the butyrate metabolism pathway (P-value = 3.8e-17) and the shigellosis pathway (P-value = 5.9e-13) in the respective associated HGTs. Furthermore, differential HGTs demonstrated promise as biomarkers for predicting various diseases. Integrating HGTs into a CRC prediction model achieved an AUC of 0.87.
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Affiliation(s)
- Shuai Wang
- City University of Hong Kong Shenzhen Research Institute, Shenzhen, China
- Department of Computer Science, City University of Hong Kong, Kowloon, Hong Kong
| | - Yiqi Jiang
- City University of Hong Kong Shenzhen Research Institute, Shenzhen, China
- Department of Computer Science, City University of Hong Kong, Kowloon, Hong Kong
| | - Lijia Che
- City University of Hong Kong Shenzhen Research Institute, Shenzhen, China
- Department of Computer Science, City University of Hong Kong, Kowloon, Hong Kong
| | - Ruo Han Wang
- City University of Hong Kong Shenzhen Research Institute, Shenzhen, China
- Department of Computer Science, City University of Hong Kong, Kowloon, Hong Kong
| | - Shuai Cheng Li
- City University of Hong Kong Shenzhen Research Institute, Shenzhen, China
- Department of Computer Science, City University of Hong Kong, Kowloon, Hong Kong
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4
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Talbot BM, Clennon JA, Rakotoarison MFN, Rautman L, Durry S, Ragazzo LJ, Wright PC, Gillespie TR, Read TD. Metagenome-wide characterization of shared antimicrobial resistance genes in sympatric people and lemurs in rural Madagascar. PeerJ 2024; 12:e17805. [PMID: 39099658 PMCID: PMC11296303 DOI: 10.7717/peerj.17805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Accepted: 07/03/2024] [Indexed: 08/06/2024] Open
Abstract
Background Tracking the spread of antibiotic resistant bacteria is critical to reduce global morbidity and mortality associated with human and animal infections. There is a need to understand the role that wild animals in maintenance and transfer of antibiotic resistance genes (ARGs). Methods This study used metagenomics to identify and compare the abundance of bacterial species and ARGs detected in the gut microbiomes from sympatric humans and wild mouse lemurs in a forest-dominated, roadless region of Madagascar near Ranomafana National Park. We examined the contribution of human geographic location toward differences in ARG abundance and compared the genomic similarity of ARGs between host source microbiomes. Results Alpha and beta diversity of species and ARGs between host sources were distinct but maintained a similar number of detectable ARG alleles. Humans were differentially more abundant for four distinct tetracycline resistance-associated genes compared to lemurs. There was no significant difference in human ARG diversity from different locations. Human and lemur microbiomes shared 14 distinct ARGs with highly conserved in nucleotide identity. Synteny of ARG-associated assemblies revealed a distinct multidrug-resistant gene cassette carrying dfrA1 and aadA1 present in human and lemur microbiomes without evidence of geographic overlap, suggesting that these resistance genes could be widespread in this ecosystem. Further investigation into intermediary processes that maintain drug-resistant bacteria in wildlife settings is needed.
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Affiliation(s)
- Brooke M. Talbot
- Program in Population Biology, Ecology, and Evolution, Emory University, Atlanta, GA, United States of America
- Division of Infectious Diseases, School of Medicine, Emory University, Atlanta, GA, United States of America
| | - Julie A. Clennon
- Department of Environmental Sciences, Emory University, Atlanta, GA, United States of America
| | | | - Lydia Rautman
- Department of Environmental Sciences, Emory University, Atlanta, GA, United States of America
| | - Sarah Durry
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, United States of America
| | - Leo J. Ragazzo
- Department of Environmental Sciences, Emory University, Atlanta, GA, United States of America
| | - Patricia C. Wright
- Centre ValBio, Ranomafana, Madagascar
- Institute for the Conservation of Tropical Ecosystems, State University of New York at Stony Brook, Stony Brook, NY, United States of America
| | - Thomas R. Gillespie
- Program in Population Biology, Ecology, and Evolution, Emory University, Atlanta, GA, United States of America
- Department of Environmental Sciences, Emory University, Atlanta, GA, United States of America
- Centre ValBio, Ranomafana, Madagascar
- Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, United States of America
| | - Timothy D. Read
- Program in Population Biology, Ecology, and Evolution, Emory University, Atlanta, GA, United States of America
- Division of Infectious Diseases, School of Medicine, Emory University, Atlanta, GA, United States of America
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5
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Kirsch JM, Hryckowian AJ, Duerkop BA. A metagenomics pipeline reveals insertion sequence-driven evolution of the microbiota. Cell Host Microbe 2024; 32:739-754.e4. [PMID: 38565143 PMCID: PMC11081829 DOI: 10.1016/j.chom.2024.03.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 02/06/2024] [Accepted: 03/08/2024] [Indexed: 04/04/2024]
Abstract
Insertion sequence (IS) elements are mobile genetic elements in bacterial genomes that support adaptation. We developed a database of IS elements coupled to a computational pipeline that identifies IS element insertions in the microbiota. We discovered that diverse IS elements insert into the genomes of intestinal bacteria regardless of human host lifestyle. These insertions target bacterial accessory genes that aid in their adaptation to unique environmental conditions. Using IS expansion in Bacteroides, we show that IS activity leads to the insertion of "hot spots" in accessory genes. We show that IS insertions are stable and can be transferred between humans. Extreme environmental perturbations force IS elements to fall out of the microbiota, and many fail to rebound following homeostasis. Our work shows that IS elements drive bacterial genome diversification within the microbiota and establishes a framework for understanding how strain-level variation within the microbiota impacts human health.
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Affiliation(s)
- Joshua M Kirsch
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, School of Medicine, Aurora, CO 80045, USA
| | - Andrew J Hryckowian
- Department of Medicine, Division of Gastroenterology and Hepatology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, USA; Department of Medical Microbiology & Immunology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, USA
| | - Breck A Duerkop
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, School of Medicine, Aurora, CO 80045, USA.
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6
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Guillén-Chable F, Valdez Iuit JO, Avila Castro LA, Rosas C, Merino E, Rodríguez-Escamilla Z, Martínez-Núñez MA. Geographical distribution of mobile genetic elements in microbial communities along the Yucatan coast. PLoS One 2024; 19:e0301642. [PMID: 38683832 PMCID: PMC11057721 DOI: 10.1371/journal.pone.0301642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 03/19/2024] [Indexed: 05/02/2024] Open
Abstract
Horizontal gene transfer (HGT) is a well-documented strategy used by bacteria to enhance their adaptability to challenging environmental conditions. Through HGT, a group of conserved genetic elements known as mobile genetic elements (MGEs) is disseminated within bacterial communities. MGEs offer numerous advantages to the host, increasing its fitness by acquiring new functions that help bacteria contend with adverse conditions, including exposure to heavy metal and antibiotics. This study explores MGEs within microbial communities along the Yucatan coast using a metatranscriptomics approach. Prior to this research, nothing was known about the coastal Yucatan's microbial environmental mobilome and HGT processes between these bacterial communities. This study reveals a positive correlation between MGEs and antibiotic resistance genes (ARGs) along the Yucatan coast, with higher MGEs abundance in more contaminated sites. The Proteobacteria and Firmicutes groups exhibited the highest number of MGEs. It's important to highlight that the most abundant classes of MGEs might not be the ones most strongly linked to ARGs, as observed for the recombination/repair class. This work presents the first geographical distribution of the environmental mobilome in Yucatan Peninsula mangroves.
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Affiliation(s)
- Francisco Guillén-Chable
- UMDI-Sisal, Facultad de Ciencias, Universidad Nacional Autónoma de México, Sisal, Yucatán, México
| | - Johnny Omar Valdez Iuit
- UMDI-Sisal, Facultad de Ciencias, Universidad Nacional Autónoma de México, Sisal, Yucatán, México
| | | | - Carlos Rosas
- UMDI-Sisal, Facultad de Ciencias, Universidad Nacional Autónoma de México, Sisal, Yucatán, México
| | - Enrique Merino
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
| | - Zuemy Rodríguez-Escamilla
- Facultad de Sistemas Biológicos e Innovación Tecnológica, Universidad Autónoma "Benito Juárez" de Oaxaca, Oaxaca de Juárez, Oaxaca, México
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7
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García-Bayona L, Said N, Coyne MJ, Flores K, Elmekki NM, Sheahan ML, Camacho AG, Hutt K, Yildiz FH, Kovács ÁT, Waldor MK, Comstock LE. A pervasive large conjugative plasmid mediates multispecies biofilm formation in the intestinal microbiota increasing resilience to perturbations. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.29.590671. [PMID: 38746121 PMCID: PMC11092513 DOI: 10.1101/2024.04.29.590671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Although horizontal gene transfer is pervasive in the intestinal microbiota, we understand only superficially the roles of most exchanged genes and how the mobile repertoire affects community dynamics. Similarly, little is known about the mechanisms underlying the ability of a community to recover after a perturbation. Here, we identified and functionally characterized a large conjugative plasmid that is one of the most frequently transferred elements among Bacteroidales species and is ubiquitous in diverse human populations. This plasmid encodes both an extracellular polysaccharide and fimbriae, which promote the formation of multispecies biofilms in the mammalian gut. We use a hybridization-based approach to visualize biofilms in clarified whole colon tissue with unprecedented 3D spatial resolution. These biofilms increase bacterial survival to common stressors encountered in the gut, increasing strain resiliency, and providing a rationale for the plasmid's recent spread and high worldwide prevalence.
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8
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Wang RH, Ng YK, Zhang X, Wang J, Li SC. Coding genomes with gapped pattern graph convolutional network. Bioinformatics 2024; 40:btae188. [PMID: 38603603 PMCID: PMC11034989 DOI: 10.1093/bioinformatics/btae188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 03/11/2024] [Accepted: 04/05/2024] [Indexed: 04/13/2024] Open
Abstract
MOTIVATION Genome sequencing technologies reveal a huge amount of genomic sequences. Neural network-based methods can be prime candidates for retrieving insights from these sequences because of their applicability to large and diverse datasets. However, the highly variable lengths of genome sequences severely impair the presentation of sequences as input to the neural network. Genetic variations further complicate tasks that involve sequence comparison or alignment. RESULTS Inspired by the theory and applications of "spaced seeds," we propose a graph representation of genome sequences called "gapped pattern graph." These graphs can be transformed through a Graph Convolutional Network to form lower-dimensional embeddings for downstream tasks. On the basis of the gapped pattern graphs, we implemented a neural network model and demonstrated its performance on diverse tasks involving microbe and mammalian genome data. Our method consistently outperformed all the other state-of-the-art methods across various metrics on all tasks, especially for the sequences with limited homology to the training data. In addition, our model was able to identify distinct gapped pattern signatures from the sequences. AVAILABILITY AND IMPLEMENTATION The framework is available at https://github.com/deepomicslab/GCNFrame.
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Affiliation(s)
- Ruo Han Wang
- Department of Computer Science, City University of Hong Kong Shenzhen Research Institute, Shen Zhen, 518063, China
- Department of Computer Science, City University of Hong Kong, Hong Kong, 999077, China
| | - Yen Kaow Ng
- Department of Computer Science, City University of Hong Kong Shenzhen Research Institute, Shen Zhen, 518063, China
- Department of Computer Science, City University of Hong Kong, Hong Kong, 999077, China
| | - Xianglilan Zhang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
| | - Jianping Wang
- Department of Computer Science, City University of Hong Kong Shenzhen Research Institute, Shen Zhen, 518063, China
- Department of Computer Science, City University of Hong Kong, Hong Kong, 999077, China
| | - Shuai Cheng Li
- Department of Computer Science, City University of Hong Kong Shenzhen Research Institute, Shen Zhen, 518063, China
- Department of Computer Science, City University of Hong Kong, Hong Kong, 999077, China
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9
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Kehlet-Delgado H, Montoya AP, Jensen KT, Wendlandt CE, Dexheimer C, Roberts M, Torres Martínez L, Friesen ML, Griffitts JS, Porter SS. The evolutionary genomics of adaptation to stress in wild rhizobium bacteria. Proc Natl Acad Sci U S A 2024; 121:e2311127121. [PMID: 38507447 PMCID: PMC10990125 DOI: 10.1073/pnas.2311127121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 02/08/2024] [Indexed: 03/22/2024] Open
Abstract
Microbiota comprise the bulk of life's diversity, yet we know little about how populations of microbes accumulate adaptive diversity across natural landscapes. Adaptation to stressful soil conditions in plants provides seminal examples of adaptation in response to natural selection via allelic substitution. For microbes symbiotic with plants however, horizontal gene transfer allows for adaptation via gene gain and loss, which could generate fundamentally different evolutionary dynamics. We use comparative genomics and genetics to elucidate the evolutionary mechanisms of adaptation to physiologically stressful serpentine soils in rhizobial bacteria in western North American grasslands. In vitro experiments demonstrate that the presence of a locus of major effect, the nre operon, is necessary and sufficient to confer adaptation to nickel, a heavy metal enriched to toxic levels in serpentine soil, and a major axis of environmental soil chemistry variation. We find discordance between inferred evolutionary histories of the core genome and nreAXY genes, which often reside in putative genomic islands. This suggests that the evolutionary history of this adaptive variant is marked by frequent losses, and/or gains via horizontal acquisition across divergent rhizobium clades. However, different nre alleles confer distinct levels of nickel resistance, suggesting allelic substitution could also play a role in rhizobium adaptation to serpentine soil. These results illustrate that the interplay between evolution via gene gain and loss and evolution via allelic substitution may underlie adaptation in wild soil microbiota. Both processes are important to consider for understanding adaptive diversity in microbes and improving stress-adapted microbial inocula for human use.
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Affiliation(s)
| | | | - Kyson T. Jensen
- Department of Microbiology and Molecular Biology, Brigham Young University, Provo, UT84602
| | | | | | - Miles Roberts
- School of Biological Sciences, Washington State University, Vancouver, WA98686
| | | | - Maren L. Friesen
- Department of Plant Pathology, Washington State University, Pullman, WA99164
- Department of Crop and Soil Sciences, Washington State University, Pullman, WA99164
| | - Joel S. Griffitts
- Department of Microbiology and Molecular Biology, Brigham Young University, Provo, UT84602
| | - Stephanie S. Porter
- School of Biological Sciences, Washington State University, Vancouver, WA98686
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10
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Kirsch JM, Hryckowian AJ, Duerkop BA. A metagenomics pipeline reveals insertion sequence-driven evolution of the microbiota. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.10.06.561241. [PMID: 37873088 PMCID: PMC10592638 DOI: 10.1101/2023.10.06.561241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Insertion sequence (IS) elements are mobile genetic elements in bacterial genomes that support adaptation. We developed a database of IS elements coupled to a computational pipeline that identifies IS element insertions in the microbiota. We discovered that diverse IS elements insert into the genomes of intestinal bacteria regardless of human host lifestyle. These insertions target bacterial accessory genes that aid in their adaptation to unique environmental conditions. Using IS expansion in Bacteroides, we show that IS activity leads to insertion "hot spots" in accessory genes. We show that IS insertions are stable and can be transferred between humans. Extreme environmental perturbations force IS elements to fall out of the microbiota and many fail to rebound following homeostasis. Our work shows that IS elements drive bacterial genome diversification within the microbiota and establishes a framework for understanding how strain level variation within the microbiota impacts human health.
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Affiliation(s)
- Joshua M. Kirsch
- Department of Immunology and Microbiology, University of Colorado - Anschutz Medical Campus, School of Medicine, Aurora, Colorado, 80045, USA
| | - Andrew J. Hryckowian
- Department of Medicine, Division of Gastroenterology and Hepatology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, 53706, USA
- Department of Medical Microbiology & Immunology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, 53706, USA
| | - Breck A. Duerkop
- Department of Immunology and Microbiology, University of Colorado - Anschutz Medical Campus, School of Medicine, Aurora, Colorado, 80045, USA
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11
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Hou J, Lam KL, Chiu YT, Kwong KY, Lau HL, Marafa LM, Tsui SKW, Mo IWY, Chan PL. Urban green waste bulking agent is the major source of antimicrobial resistance genes persisted in home compost, not animal manure. ENVIRONMENTAL RESEARCH 2024; 242:117713. [PMID: 38000633 DOI: 10.1016/j.envres.2023.117713] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 10/27/2023] [Accepted: 11/15/2023] [Indexed: 11/26/2023]
Abstract
Urban green waste and food waste are often used as bulking agents to prepare home compost in combination with animal manure in urban horticulture and community gardening. Although it is known that antimicrobial resistance genes (ARGs) persist in home compost, their origins have not been determined. In addition, the factors contributing to ARGs persistence remain unclear. In this study, we aim to (i) characterize the changes in the microbiome and antimicrobial resistome during the composting process of home compost using metagenomics shotgun sequencing, (ii) identify the source of the ARGs persisted in home compost using SourceTracker, and (iii) elucidate the collective effect of compost microbiome and environmental factors, including the physicochemical properties and antibiotics concentration of home compost, in contributing to ARG persistence using Procrustes analysis, co-occurrence network analysis, variation partitioning analysis, and structural equation modeling. SourceTracker analysis indicated that urban green waste bulking agent was the major source of the persisting ARGs in home compost instead of animal manure. Procrustes analysis and co-occurrence network analysis revealed a strong association between microbiome and antimicrobial resistome. Variation partitioning analysis and structural equation modeling suggested that physicochemical properties shaped the antimicrobial resistome directly and indirectly by influencing the microbiome. Our results indicated that the persistence of ARGs in home compost might be due to the succession of microbial species from the urban green waste bulking agent, and the physicochemical properties might have defined the compost environment to shape the microbiome in the compost, thus, in turn, the persisting antimicrobial resistome.
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Affiliation(s)
- Jinpao Hou
- School of Biomedical Sciences, the Chinese University of Hong Kong, Shatin, Hong Kong
| | - K L Lam
- Department of Applied Science, School of Science and Technology, Hong Kong Metropolitan University, Ho Man Tin, Hong Kong
| | - Y T Chiu
- Department of Applied Science, School of Science and Technology, Hong Kong Metropolitan University, Ho Man Tin, Hong Kong
| | - K Y Kwong
- Department of Applied Science, School of Science and Technology, Hong Kong Metropolitan University, Ho Man Tin, Hong Kong
| | - H L Lau
- Department of Geography and Resources Management, the Chinese University of Hong Kong, Shatin, Hong Kong
| | - L M Marafa
- Department of Geography and Resources Management, the Chinese University of Hong Kong, Shatin, Hong Kong
| | - S K W Tsui
- School of Biomedical Sciences, the Chinese University of Hong Kong, Shatin, Hong Kong
| | - I W Y Mo
- Department of Applied Science, School of Science and Technology, Hong Kong Metropolitan University, Ho Man Tin, Hong Kong.
| | - P L Chan
- Department of Applied Science, School of Science and Technology, Hong Kong Metropolitan University, Ho Man Tin, Hong Kong; Department of Health Sciences, School of Nursing and Health Studies, Hong Kong Metropolitan University, Ho Man Tin, Hong Kong.
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12
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Tripathi S, Voogdt CGP, Bassler SO, Anderson M, Huang PH, Sakenova N, Capraz T, Jain S, Koumoutsi A, Bravo AM, Trotter V, Zimmerman M, Sonnenburg JL, Buie C, Typas A, Deutschbauer AM, Shiver AL, Huang KC. Randomly barcoded transposon mutant libraries for gut commensals I: Strategies for efficient library construction. Cell Rep 2024; 43:113517. [PMID: 38142397 DOI: 10.1016/j.celrep.2023.113517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 10/22/2023] [Accepted: 11/14/2023] [Indexed: 12/26/2023] Open
Abstract
Randomly barcoded transposon mutant libraries are powerful tools for studying gene function and organization, assessing gene essentiality and pathways, discovering potential therapeutic targets, and understanding the physiology of gut bacteria and their interactions with the host. However, construction of high-quality libraries with uniform representation can be challenging. In this review, we survey various strategies for barcoded library construction, including transposition systems, methods of transposon delivery, optimal library size, and transconjugant selection schemes. We discuss the advantages and limitations of each approach, as well as factors to consider when selecting a strategy. In addition, we highlight experimental and computational advances in arraying condensed libraries from mutant pools. We focus on examples of successful library construction in gut bacteria and their application to gene function studies and drug discovery. Given the need for understanding gene function and organization in gut bacteria, we provide a comprehensive guide for researchers to construct randomly barcoded transposon mutant libraries.
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Affiliation(s)
- Surya Tripathi
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Carlos Geert Pieter Voogdt
- Genome Biology Unit, EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany; Structural and Computational Biology Unit, EMBL Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Stefan Oliver Bassler
- Genome Biology Unit, EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany; Faculty of Biosciences, Heidelberg University, Grabengasse 1, 69117 Heidelberg, Germany
| | - Mary Anderson
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Po-Hsun Huang
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Nazgul Sakenova
- Genome Biology Unit, EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Tümay Capraz
- Genome Biology Unit, EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany; Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Sunit Jain
- Chan Zuckerberg Biohub, San Francisco, CA 94158, USA
| | - Alexandra Koumoutsi
- Genome Biology Unit, EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Afonso Martins Bravo
- Department of Fundamental Microbiology, University of Lausanne, 1015 Lausanne, Switzerland
| | - Valentine Trotter
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Michael Zimmerman
- Structural and Computational Biology Unit, EMBL Meyerhofstraße 1, 69117 Heidelberg, Germany
| | - Justin L Sonnenburg
- Chan Zuckerberg Biohub, San Francisco, CA 94158, USA; Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Cullen Buie
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Athanasios Typas
- Genome Biology Unit, EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany; Structural and Computational Biology Unit, EMBL Meyerhofstraße 1, 69117 Heidelberg, Germany.
| | - Adam M Deutschbauer
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720, USA; Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
| | - Anthony L Shiver
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA.
| | - Kerwyn Casey Huang
- Chan Zuckerberg Biohub, San Francisco, CA 94158, USA; Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Bioengineering, Stanford University, Stanford, CA 94305, USA.
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13
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López-Beltrán A, Botelho J, Iranzo J. Dynamics of CRISPR-mediated virus-host interactions in the human gut microbiome. THE ISME JOURNAL 2024; 18:wrae134. [PMID: 39023219 PMCID: PMC11307328 DOI: 10.1093/ismejo/wrae134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 06/07/2024] [Accepted: 07/17/2024] [Indexed: 07/20/2024]
Abstract
Arms races between mobile genetic elements and prokaryotic hosts are major drivers of ecological and evolutionary change in microbial communities. Prokaryotic defense systems such as CRISPR-Cas have the potential to regulate microbiome composition by modifying the interactions among bacteria, plasmids, and phages. Here, we used longitudinal metagenomic data from 130 healthy and diseased individuals to study how the interplay of genetic parasites and CRISPR-Cas immunity reflects on the dynamics and composition of the human gut microbiome. Based on the coordinated study of 80 000 CRISPR-Cas loci and their targets, we show that CRISPR-Cas immunity effectively modulates bacteriophage abundances in the gut. Acquisition of CRISPR-Cas immunity typically leads to a decrease in the abundance of lytic phages but does not necessarily cause their complete disappearance. Much smaller effects are observed for lysogenic phages and plasmids. Conversely, phage-CRISPR interactions shape bacterial microdiversity by producing weak selective sweeps that benefit immune host lineages. We also show that distal (and chronologically older) regions of CRISPR arrays are enriched in spacers that are potentially functional and target crass-like phages and local prophages. This suggests that exposure to reactivated prophages and other endemic viruses is a major selective pressure in the gut microbiome that drives the maintenance of long-lasting immune memory.
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Affiliation(s)
- Adrián López-Beltrán
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA-CSIC), Parque Científico y Tecnológico UPM, Campus de Montegancedo, 28223, Madrid, Spain
| | - João Botelho
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA-CSIC), Parque Científico y Tecnológico UPM, Campus de Montegancedo, 28223, Madrid, Spain
| | - Jaime Iranzo
- Centro de Astrobiología (CAB), CSIC-INTA, Ctra. de Torrejón a Ajalvir Km 4, 28850, Torrejón de Ardoz, Madrid, Spain
- Institute for Biocomputation and Physics of Complex Systems (BIFI), University of Zaragoza, Campus Río Ebro, 50018, Zaragoza, Spain
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14
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Igo M, Xu L, Krishna A, Stewart S, Xu L, Li Z, Weaver JL, Stone H, Sacks L, Bensman T, Florian J, Rouse R, Han X. A metagenomic analysis for combination therapy of multiple classes of antibiotics on the prevention of the spread of antibiotic-resistant genes. Gut Microbes 2023; 15:2271150. [PMID: 37908118 PMCID: PMC10621307 DOI: 10.1080/19490976.2023.2271150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 10/11/2023] [Indexed: 11/02/2023] Open
Abstract
Antibiotics used systemically to treat infections may have off-target effects on the gut microbiome, potentially resulting in the emergence of drug-resistant bacteria or selection of pathogenic species. These organisms may present a risk to the host and spread to the environment with a risk of transmission in the community. To investigate the risk of emergent antibiotic resistance in the gut microbiome following systemic treatment with antibiotics, this metagenomic analysis project used next-generation sequencing, a custom-built metagenomics pipeline, and differential abundance analysis to study the effect of antibiotics (ampicillin, ciprofloxacin, and fosfomycin) in monotherapy and different combinations at high and low doses, to determine the effect on resistome and taxonomic composition in the gut of Balb/c mice. The results showed that low-dose monotherapy treatments showed little change in microbiome composition but did show an increase in expression of many antibiotic-resistant genes (ARGs) posttreatment. Dual combination treatments allowed the emergence of some conditionally pathogenic bacteria and some increase in the abundance of ARGs despite a general decrease in microbiota diversity. Triple combination treatment was the most successful in inhibiting emergence of relevant opportunistic pathogens and completely suppressed all ARGs after 72 h of treatment. The relative abundances of mobile genetic elements that can enhance transmission of antibiotic resistance either decreased or remained the same for combination therapy while increasing for low-dose monotherapy. Combination therapy prevented the emergence of ARGs and decreased bacterial diversity, while low-dose monotherapy treatment increased ARGs and did not greatly change bacterial diversity.
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Affiliation(s)
- Matthew Igo
- Division of Applied Regulatory Science, Office of Clinical Pharmacology, Office of Translational Sciences, Center for Drug Evaluation and Research, U. S. Food and Drug Administration, Silver Spring, MD, USA
| | - Lei Xu
- Division of Applied Regulatory Science, Office of Clinical Pharmacology, Office of Translational Sciences, Center for Drug Evaluation and Research, U. S. Food and Drug Administration, Silver Spring, MD, USA
| | - Ashok Krishna
- Division of Applied Regulatory Science, Office of Clinical Pharmacology, Office of Translational Sciences, Center for Drug Evaluation and Research, U. S. Food and Drug Administration, Silver Spring, MD, USA
| | - Sharron Stewart
- Division of Applied Regulatory Science, Office of Clinical Pharmacology, Office of Translational Sciences, Center for Drug Evaluation and Research, U. S. Food and Drug Administration, Silver Spring, MD, USA
| | - Lin Xu
- Division of Applied Regulatory Science, Office of Clinical Pharmacology, Office of Translational Sciences, Center for Drug Evaluation and Research, U. S. Food and Drug Administration, Silver Spring, MD, USA
| | - Zhihua Li
- Division of Applied Regulatory Science, Office of Clinical Pharmacology, Office of Translational Sciences, Center for Drug Evaluation and Research, U. S. Food and Drug Administration, Silver Spring, MD, USA
| | - James L. Weaver
- Division of Applied Regulatory Science, Office of Clinical Pharmacology, Office of Translational Sciences, Center for Drug Evaluation and Research, U. S. Food and Drug Administration, Silver Spring, MD, USA
| | - Heather Stone
- Office of Medical Policy, Center for Drug Evaluation and Research, U. S. Food and Drug Administration, Silver Spring, MD, USA
| | - Leonard Sacks
- Office of Medical Policy, Center for Drug Evaluation and Research, U. S. Food and Drug Administration, Silver Spring, MD, USA
| | - Timothy Bensman
- Division of Infectious Disease Pharmacology, Office of Clinical Pharmacology, Office of Translational Sciences, Center for Drug Evaluation and Research, U. S. Food and Drug Administration, Silver Spring, MD, USA
| | - Jeffry Florian
- Division of Applied Regulatory Science, Office of Clinical Pharmacology, Office of Translational Sciences, Center for Drug Evaluation and Research, U. S. Food and Drug Administration, Silver Spring, MD, USA
| | - Rodney Rouse
- Division of Applied Regulatory Science, Office of Clinical Pharmacology, Office of Translational Sciences, Center for Drug Evaluation and Research, U. S. Food and Drug Administration, Silver Spring, MD, USA
| | - Xiaomei Han
- Division of Applied Regulatory Science, Office of Clinical Pharmacology, Office of Translational Sciences, Center for Drug Evaluation and Research, U. S. Food and Drug Administration, Silver Spring, MD, USA
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15
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Kim JJ, Seong HJ, Johnson TA, Cha CJ, Sul WJ, Chae JC. Persistence of antibiotic resistance from animal agricultural effluents to surface water revealed by genome-centric metagenomics. JOURNAL OF HAZARDOUS MATERIALS 2023; 457:131761. [PMID: 37290355 DOI: 10.1016/j.jhazmat.2023.131761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 05/25/2023] [Accepted: 06/01/2023] [Indexed: 06/10/2023]
Abstract
Concerns about antibiotic resistance genes (ARGs) released from wastewaters of livestock or fish farming into the natural environment are increasing, but studies on unculturable bacteria related to the dissemination of antibiotic resistance are limited. Here, we reconstructed 1100 metagenome-assembled genomes (MAGs) to assess the impact of microbial antibiotic resistome and mobilome in wastewaters discharged to Korean rivers. Our results indicate that ARGs harbored in the MAGs were disseminated from wastewater effluents into downstream rivers. Moreover, it was found that ARGs are more commonly co-localized with mobile genetic elements (MGEs) in agricultural wastewater than in river water. Among the effluent-derived phyla, uncultured members of the superphylum Patescibacteria possessed a high number of MGEs, along with co-localized ARGs. Our findings suggest that members of the Patesibacteria are a potential vector for propagating ARGs into the environmental community. Therefore, we propose that the dissemination of ARGs by uncultured bacteria should be further investigated in multiple environments.
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Affiliation(s)
- Jin Ju Kim
- Department of Systems Biotechnology, Chung-Ang University, Anseong 17546, Republic of Korea
| | - Hoon Je Seong
- Department of Systems Biotechnology, Chung-Ang University, Anseong 17546, Republic of Korea; Korean Medicine Data Division, Korea Institute of Oriental Medicine, Daejeon 34054, Republic of Korea
| | - Timothy A Johnson
- Department of Animal Sciences, Purdue University, West Lafayette, IN 47907, United States
| | - Chang-Jun Cha
- Department of Systems Biotechnology, Chung-Ang University, Anseong 17546, Republic of Korea
| | - Woo Jun Sul
- Department of Systems Biotechnology, Chung-Ang University, Anseong 17546, Republic of Korea.
| | - Jong-Chan Chae
- Division of Biotechnology, Jeonbuk National University, Iksan 54596, Republic of Korea.
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16
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Dukes HE, Tinker KA, Ottesen EA. Disentangling hindgut metabolism in the American cockroach through single-cell genomics and metatranscriptomics. Front Microbiol 2023; 14:1156809. [PMID: 37323917 PMCID: PMC10266427 DOI: 10.3389/fmicb.2023.1156809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 05/08/2023] [Indexed: 06/17/2023] Open
Abstract
Omnivorous cockroaches host a complex hindgut microbiota comprised of insect-specific lineages related to those found in mammalian omnivores. Many of these organisms have few cultured representatives, thereby limiting our ability to infer the functional capabilities of these microbes. Here we present a unique reference set of 96 high-quality single cell-amplified genomes (SAGs) from bacterial and archaeal cockroach gut symbionts. We additionally generated cockroach hindgut metagenomic and metatranscriptomic sequence libraries and mapped them to our SAGs. By combining these datasets, we are able to perform an in-depth phylogenetic and functional analysis to evaluate the abundance and activities of the taxa in vivo. Recovered lineages include key genera within Bacteroidota, including polysaccharide-degrading taxa from the genera Bacteroides, Dysgonomonas, and Parabacteroides, as well as a group of unclassified insect-associated Bacteroidales. We also recovered a phylogenetically diverse set of Firmicutes exhibiting a wide range of metabolic capabilities, including-but not limited to-polysaccharide and polypeptide degradation. Other functional groups exhibiting high relative activity in the metatranscriptomic dataset include multiple putative sulfate reducers belonging to families in the Desulfobacterota phylum and two groups of methanogenic archaea. Together, this work provides a valuable reference set with new insights into the functional specializations of insect gut symbionts and frames future studies of cockroach hindgut metabolism.
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Affiliation(s)
- Helen E Dukes
- Department of Microbiology, University of Georgia, Athens, GA, United States
| | - Kara A Tinker
- National Energy Technology Laboratory (NETL), Pittsburgh, PA, United States
| | - Elizabeth A Ottesen
- Department of Microbiology, University of Georgia, Athens, GA, United States
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17
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Zhang L, Guo H, Gu J, Hu T, Wang X, Sun Y, Li H, Sun W, Qian X, Song Z, Xie J, An L. Metagenomic insights into dietary remodeling of gut microbiota and antibiotic resistome in meat rabbits. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 874:162006. [PMID: 36791852 DOI: 10.1016/j.scitotenv.2023.162006] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 01/28/2023] [Accepted: 01/30/2023] [Indexed: 06/18/2023]
Abstract
The gut microbiota is a repository of antibiotic resistance genes (ARGs), which may affect the health of humans and animals. The intestinal flora is affected by many factors but it is unclear how the intestinal microflora and antibiotic resistome in rabbits might change under dietary intervention. Feeding with lettuce led to the amplification and transfer of exogenous ARGs in the intestinal flora, but there were no significant differences when fed lettuces grown with different manure types. For example, the lsaC of lettuce fed with bovine, chicken and pig manure without adding organic fertilizer increased by 0.143, 0.151, 0.179 and 0.169 logs respectively after 4 weeks, and the efrB also increased by 0.074, 0.068, 0.079 and 0.106 logs respectively. Network analysis showed that Clostridium_ sensu_ stricto_ 18 was a potential host of type 6 virulence factor genes (VFGs). Mantel analysis showed that ARGs were directly influenced by mobile genetic elements (MGEs) and VFGs. Thus, feeding rabbits lettuce grown with different manure types contribute to the transmission of ARGs by remodeling the intestinal microenvironment. In addition, diet may affect exogenous ARGs to change the intestinal antibiotic resistome and possibly threaten health.
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Affiliation(s)
- Li Zhang
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Honghong Guo
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China; Shaanxi Key Laboratory of Environmental Engineering, Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Jie Gu
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China; Research Center of Recycle Agricultural Engineering and Technology of Shaanxi Province, Northwest A&F University, Yangling, Shaanxi 712100, China.
| | - Ting Hu
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Xiaojuan Wang
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Yifan Sun
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Huakang Li
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Wei Sun
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Xun Qian
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Zilin Song
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Jun Xie
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Lu An
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China
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18
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Moura de Sousa J, Lourenço M, Gordo I. Horizontal gene transfer among host-associated microbes. Cell Host Microbe 2023; 31:513-527. [PMID: 37054673 DOI: 10.1016/j.chom.2023.03.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/15/2023]
Abstract
Horizontal gene transfer is an important evolutionary force, facilitating bacterial diversity. It is thought to be pervasive in host-associated microbiomes, where bacterial densities are high and mobile elements are frequent. These genetic exchanges are also key for the rapid dissemination of antibiotic resistance. Here, we review recent studies that have greatly extended our knowledge of the mechanisms underlying horizontal gene transfer, the ecological complexities of a network of interactions involving bacteria and their mobile elements, and the effect of host physiology on the rates of genetic exchanges. Furthermore, we discuss other, fundamental challenges in detecting and quantifying genetic exchanges in vivo, and how studies have contributed to start overcoming these challenges. We highlight the importance of integrating novel computational approaches and theoretical models with experimental methods where multiple strains and transfer elements are studied, both in vivo and in controlled conditions that mimic the intricacies of host-associated environments.
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Affiliation(s)
- Jorge Moura de Sousa
- Institut Pasteur, Université Paris Cité, CNRS, UMR3525, Microbial Evolutionary Genomics, Paris, 75015 Paris, France
| | - Marta Lourenço
- Institut Pasteur, Université Paris Cité, Biodiversity and Epidemiology of Bacterial Pathogens, F-75015 Paris, France
| | - Isabel Gordo
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande,6, Oeiras, Portugal.
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19
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Yi X, Wen P, Liang JL, Jia P, Yang TT, Feng SW, Liao B, Shu WS, Li JT. Phytostabilization mitigates antibiotic resistance gene enrichment in a copper mine tailings pond. JOURNAL OF HAZARDOUS MATERIALS 2023; 443:130255. [PMID: 36327844 DOI: 10.1016/j.jhazmat.2022.130255] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 09/06/2022] [Accepted: 10/23/2022] [Indexed: 06/16/2023]
Abstract
Mining-impacted environments are distributed globally and have become increasingly recognized as hotspots of antibiotic resistance genes (ARGs). However, there are currently no reports on treatment technologies to deal with such an important environmental problem. To narrow this knowledge gap, we implemented a phytostabilization project in an acidic copper mine tailings pond and employed metagenomics to explore ARG characteristics in the soil samples. Our results showed that phytostabilization decreased the total ARG abundance in 0-10 cm soil layer by 75 %, which was companied by a significant decrease in ARG mobility, and a significant increase in ARG diversity and microbial diversity. Phytostabilization was also found to drastically alter the ARG host composition and to significantly reduce the total abundance of virulence factor genes of ARG hosts. Soil nutrient status, heavy metal toxicity and SO42- concentration were important physicochemical factors to affect the total ARG abundance, while causal mediation analysis showed that their effects were largely mediated by the changes in ARG mobility and microbial diversity. The increase in ARG diversity associated with phytostabilization was mainly mediated by a small subgroup of ARG hosts, most of which could not be classified at the genus level and deserve further research in the future.
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Affiliation(s)
- Xinzhu Yi
- Institute of Ecological Science, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou 510631, PR China
| | - Ping Wen
- Institute of Ecological Science, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou 510631, PR China
| | - Jie-Liang Liang
- Institute of Ecological Science, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou 510631, PR China
| | - Pu Jia
- Institute of Ecological Science, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou 510631, PR China
| | - Tao-Tao Yang
- School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, PR China
| | - Shi-Wei Feng
- Institute of Ecological Science, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou 510631, PR China
| | - Bin Liao
- School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, PR China
| | - Wen-Sheng Shu
- Institute of Ecological Science, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou 510631, PR China
| | - Jin-Tian Li
- Institute of Ecological Science, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou 510631, PR China.
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20
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Mencía-Ares O, Borowiak M, Argüello H, Cobo-Díaz JF, Malorny B, Álvarez-Ordóñez A, Carvajal A, Deneke C. Genomic Insights into the Mobilome and Resistome of Sentinel Microorganisms Originating from Farms of Two Different Swine Production Systems. Microbiol Spectr 2022; 10:e0289622. [PMID: 36377950 PMCID: PMC9769681 DOI: 10.1128/spectrum.02896-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 11/02/2022] [Indexed: 11/16/2022] Open
Abstract
Antimicrobial resistance (AMR) is a threat to public health due to long-term antimicrobial use (AMU), which promotes the bacterial acquisition of antimicrobial resistance determinants (ARDs). Within food-producing animals, organic and extensive Iberian swine production is based on sustainable and eco-friendly management systems, providing an excellent opportunity to evaluate how sustained differences in AMU impact the development and spread of AMR. Here, through a whole-genome sequencing approach, we provide an in-depth characterization of the resistome and mobilome and their interaction in 466 sentinel bacteria, namely, Escherichia coli, Enterococcus spp., Campylobacter coli, and Staphylococcus spp., recovered from 37 intensive and organic-extensive pig farms. Both ARDs and mobile genetic elements (MGEs) were primarily taxon-associated, with higher similarities among bacteria which were closely phylogenetically related. E. coli exhibited the most diverse resistome and mobilome, with 85.4% mobilizable ARDs, 50.3% of which were plasmid-associated. Staphylococcus spp. exhibited a broad repertoire of ARDs and MGEs, with 52.3% of its resistome being mobilizable. Although Enterococcus spp. carried the highest number of ARDs per isolate and its plasmidome was similar in size to that of E. coli, 43.7% of its resistome was mobilizable. A narrow spectrum of ARDs constituted the C. coli resistome, with point mutations as its main AMR driver. A constrained AMU, as observed in organic-extensive herds, determined a reduction in the quantitative composition of the resistome and the complexity of the resistome-mobilome interaction. These results demonstrate taxon-associated AMR-MGE interactions and evidence that responsible AMU can contribute to reducing AMR pressure in the food chain. IMPORTANCE This study provides the first integral genomic characterization of the resistome and mobilome of sentinel microorganisms for antimicrobial resistance (AMR) surveillance from two different swine production systems. Relevant differences were observed among taxa in the resistomes and mobilomes they harbored, revealing their distinctive risk in AMR dissemination and spread. Thus, Escherichia coli and, to a lesser extent, Staphylococcus spp. constituted the main reservoirs of mobilizable antimicrobial resistance genes, which were predominantly plasmid-associated; in contrast to Campylobacter coli, whose resistome was mainly determined by point mutations. The reduced complexity of mobilome-resistome interaction in Enterococcus spp. suggested its limited role in AMR dissemination from swine farms. The significant differences in antimicrobial use among the studied farms allowed us to assess the suitability of whole-genome sequencing as a rapid and efficient technique for the assessment of mid- to long-term on-farm interventions for the reduction of antimicrobial use and the evaluation of AMR status.
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Affiliation(s)
- Oscar Mencía-Ares
- Department of Animal Health, Veterinary Faculty, Universidad de León, León, Spain
| | - Maria Borowiak
- Department of Biological Safety, German Federal Institute for Risk Assessment, Berlin, Germany
| | - Héctor Argüello
- Department of Animal Health, Veterinary Faculty, Universidad de León, León, Spain
| | - José Francisco Cobo-Díaz
- Department of Food Hygiene and Technology, Veterinary Faculty, Universidad de León, León, Spain
- Institute of Food Science and Technology, Universidad de León, León, Spain
| | - Burkhard Malorny
- Department of Biological Safety, German Federal Institute for Risk Assessment, Berlin, Germany
| | - Avelino Álvarez-Ordóñez
- Department of Food Hygiene and Technology, Veterinary Faculty, Universidad de León, León, Spain
- Institute of Food Science and Technology, Universidad de León, León, Spain
| | - Ana Carvajal
- Department of Animal Health, Veterinary Faculty, Universidad de León, León, Spain
| | - Carlus Deneke
- Department of Biological Safety, German Federal Institute for Risk Assessment, Berlin, Germany
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21
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McLellan LK, Anderson ME, Grossman AD. TnSmu1 is a functional integrative and conjugative element in Streptococcus mutans that when expressed causes growth arrest of host bacteria. Mol Microbiol 2022; 118:652-669. [PMID: 36268794 PMCID: PMC10098952 DOI: 10.1111/mmi.14992] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 10/14/2022] [Accepted: 10/17/2022] [Indexed: 01/18/2023]
Abstract
Integrative and conjugative elements (ICEs) are major drivers of horizontal gene transfer in bacteria. They mediate their own transfer from host cells (donors) to recipients and allow bacteria to acquire new phenotypes, including pathogenic and metabolic capabilities and drug resistances. Streptococcus mutans, a major causative agent of dental caries, contains a putative ICE, TnSmu1, integrated at the 3' end of a leucyl tRNA gene. We found that TnSmu1 is a functional ICE, containing all the genes necessary for ICE function. It excised from the chromosome and excision was stimulated by DNA damage. We identified the DNA junctions generated by excision of TnSmu1, defined the ends of the element, and detected the extrachromosomal circle. We found that TnSmu1 can transfer from S. mutans donors to recipients when co-cultured on solid medium. The presence of TnSmu1 in recipients inhibited successful acquisition of another copy and this inhibition was mediated, at least in part, by the likely transcriptional repressor encoded by the element. Using microscopy to track individual cells, we found that activation of TnSmu1 caused an arrest of cell growth. Our results demonstrate that TnSmu1 is a functional ICE that affects the biology of its host cells.
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Affiliation(s)
- Lisa K McLellan
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Mary E Anderson
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Alan D Grossman
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
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22
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Wang P, Jiang X, Mu K, Jing Y, Yin Z, Cui Y, Li C, Luo X, Chen F, Yu T, Zhu Z, Sun Y, Chen F, Zhou D. DANMEL: A manually curated reference database for analyzing mobile genetic elements associated with bacterial drug resistance. MLIFE 2022; 1:460-464. [PMID: 38818485 PMCID: PMC10989931 DOI: 10.1002/mlf2.12046] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 11/04/2022] [Accepted: 11/07/2022] [Indexed: 06/01/2024]
Abstract
We have developed a manually curated online reference database, DANMEL (http://124.239.252.254/danmel/), that addresses the lack of accurate dissection and annotation of the genetic structures of mobile genetic elements (MGEs) with genes for drug resistance. DANMEL contains accurately annotated and genetically dissected reference MGEs covering 5 categories and 135 subcategories/subfamilies of MGEs. Further, DANMEL provides a detailed guide on how to precisely annotate MGEs. DANMEL also provides SEARCH/BLAST functions to facilitate finding reference MGEs. Overall, DANMEL will aid researchers to conduct in-depth genetic analysis of sequenced bacterial MGEs with drug-resistance genes and further facilitate a better understanding of bacterial MGEs associated with drug resistance at a genomic level.
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Affiliation(s)
- Peng Wang
- State Key Laboratory of Pathogen and BiosecurityBeijing Institute of Microbiology and EpidemiologyBeijingChina
| | - Xiaoyuan Jiang
- State Key Laboratory of Pathogen and BiosecurityBeijing Institute of Microbiology and EpidemiologyBeijingChina
- Beijing Institute of Genomics, Chinese Academy of SciencesChina National Center for BioinformationBeijingChina
| | - Kai Mu
- State Key Laboratory of Pathogen and BiosecurityBeijing Institute of Microbiology and EpidemiologyBeijingChina
| | - Ying Jing
- State Key Laboratory of Pathogen and BiosecurityBeijing Institute of Microbiology and EpidemiologyBeijingChina
| | - Zhe Yin
- State Key Laboratory of Pathogen and BiosecurityBeijing Institute of Microbiology and EpidemiologyBeijingChina
| | - Yujun Cui
- State Key Laboratory of Pathogen and BiosecurityBeijing Institute of Microbiology and EpidemiologyBeijingChina
| | - Cuidan Li
- Beijing Institute of Genomics, Chinese Academy of SciencesChina National Center for BioinformationBeijingChina
| | - Xinhua Luo
- State Key Laboratory of Pathogen and BiosecurityBeijing Institute of Microbiology and EpidemiologyBeijingChina
| | - Fangzhou Chen
- State Key Laboratory of Pathogen and BiosecurityBeijing Institute of Microbiology and EpidemiologyBeijingChina
| | - Ting Yu
- State Key Laboratory of Pathogen and BiosecurityBeijing Institute of Microbiology and EpidemiologyBeijingChina
| | - Zhichen Zhu
- State Key Laboratory of Pathogen and BiosecurityBeijing Institute of Microbiology and EpidemiologyBeijingChina
| | - Yansong Sun
- State Key Laboratory of Pathogen and BiosecurityBeijing Institute of Microbiology and EpidemiologyBeijingChina
| | - Fei Chen
- Beijing Institute of Genomics, Chinese Academy of SciencesChina National Center for BioinformationBeijingChina
- University of Chinese Academy of SciencesBeijingChina
| | - Dongsheng Zhou
- State Key Laboratory of Pathogen and BiosecurityBeijing Institute of Microbiology and EpidemiologyBeijingChina
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23
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Butala M, Dragoš A. Unique relationships between phages and endospore-forming hosts. Trends Microbiol 2022; 31:498-510. [PMID: 36535834 DOI: 10.1016/j.tim.2022.11.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 11/23/2022] [Accepted: 11/23/2022] [Indexed: 12/23/2022]
Abstract
As part of their survival strategy under harsh environmental conditions, endospore-forming bacteria can trigger a sporulation developmental program. Although the regulatory cascades that precisely control the transformation of vegetative bacteria into mother cells and resilient spores have been described in detail, less is known about how bacteriophages that prey on endospore-formers exploit sporulation. Herein, we argue that phages infecting these bacteria have evolved several specific molecular mechanisms, not yet known in other bacteria, that manifest from the phage-driven alliance to negative effects on the host. We anticipate that the relationships between phages and endospore-formers outlined here will inspire studies on phage ecology and evolution, and could facilitate important advances in the development of phage therapies against pathogenic spore-formers.
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Affiliation(s)
- Matej Butala
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Anna Dragoš
- Department of Microbiology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia.
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24
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mobileOG-db: a Manually Curated Database of Protein Families Mediating the Life Cycle of Bacterial Mobile Genetic Elements. Appl Environ Microbiol 2022; 88:e0099122. [PMID: 36036594 PMCID: PMC9499024 DOI: 10.1128/aem.00991-22] [Citation(s) in RCA: 77] [Impact Index Per Article: 38.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacterial mobile genetic elements (MGEs) encode functional modules that perform both core and accessory functions for the element, the latter of which are often only transiently associated with the element. The presence of these accessory genes, which are often close homologs to primarily immobile genes, incur high rates of false positives and, therefore, limits the usability of these databases for MGE annotation. To overcome this limitation, we analyzed 10,776,849 protein sequences derived from eight MGE databases to compile a comprehensive set of 6,140 manually curated protein families that are linked to the “life cycle” (integration/excision, replication/recombination/repair, transfer, stability/transfer/defense, and phage-specific processes) of plasmids, phages, integrative, transposable, and conjugative elements. We overlay experimental information where available to create a tiered annotation scheme of high-quality annotations and annotations inferred exclusively through bioinformatic evidence. We additionally provide an MGE-class label for each entry (e.g., plasmid or integrative element), and assign to each entry a major and minor category. The resulting database, mobileOG-db (for mobile orthologous groups), comprises over 700,000 deduplicated sequences encompassing five major mobileOG categories and more than 50 minor categories, providing a structured language and interpretable basis for an array of MGE-centered analyses. mobileOG-db can be accessed at mobileogdb.flsi.cloud.vt.edu/, where users can select, refine, and analyze custom subsets of the dynamic mobilome. IMPORTANCE The analysis of bacterial mobile genetic elements (MGEs) in genomic data is a critical step toward profiling the root causes of antibiotic resistance, phenotypic or metabolic diversity, and the evolution of bacterial genera. Existing methods for MGE annotation pose high barriers of biological and computational expertise to properly harness. To bridge this gap, we systematically analyzed 10,776,849 proteins derived from eight databases of MGEs to identify 6,140 MGE protein families that can serve as candidate hallmarks, i.e., proteins that can be used as “signatures” of MGEs to aid annotation. The resulting resource, mobileOG-db, provides a multilevel classification scheme that encompasses plasmid, phage, integrative, and transposable element protein families categorized into five major mobileOG categories and more than 50 minor categories. mobileOG-db thus provides a rich resource for simple and intuitive element annotation that can be integrated seamlessly into existing MGE detection pipelines and colocalization analyses.
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25
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Chuprikova L, Mateo-Cáceres V, de Toro M, Redrejo-Rodríguez M. ExplorePipolin: reconstruction and annotation of piPolB-encoding bacterial mobile elements from draft genomes. BIOINFORMATICS ADVANCES 2022; 2:vbac056. [PMID: 36699382 PMCID: PMC9710591 DOI: 10.1093/bioadv/vbac056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 07/18/2022] [Accepted: 08/06/2022] [Indexed: 01/28/2023]
Abstract
Motivation Detailed and accurate analysis of mobile genetic elements (MGEs) in bacteria is essential to deal with the current threat of multiresistant microbes. The overwhelming use of draft, contig-based genomes hinder the delineation of the genetic structure of these plastic and variable genomic stretches, as in the case of pipolins, a superfamily of MGEs that spans diverse integrative and plasmidic elements, characterized by the presence of a primer-independent DNA polymerase. Results ExplorePipolin is a Python-based pipeline that screens for the presence of the element and performs its reconstruction and annotation. The pipeline can be used on virtually any genome from diverse organisms and of diverse quality, obtaining the highest-scored possible structure and reconstructed out of different contigs if necessary. Then, predicted pipolin boundaries and pipolin encoded genes are subsequently annotated using a custom database, returning the standard file formats suitable for comparative genomics of this mobile element. Availability and implementation All code is available and can be accessed here: github.com/pipolinlab/ExplorePipolin. Supplementary information Supplementary data are available at Bioinformatics Advances online.
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Affiliation(s)
| | - V Mateo-Cáceres
- Department of Biochemistry, School of Medicine, Universidad Autónoma de Madrid and Instituto de Investigaciones Biomédicas ‘Alberto Sols’ (UAM-CSIC), Madrid, Spain
| | - M de Toro
- Plataforma de Genómica y Bioinformática, CIBIR (Centro de Investigación Biomédica de La Rioja), Logroño, La Rioja 26006, Spain
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26
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Ott LC, Mellata M. Models for Gut-Mediated Horizontal Gene Transfer by Bacterial Plasmid Conjugation. Front Microbiol 2022; 13:891548. [PMID: 35847067 PMCID: PMC9280185 DOI: 10.3389/fmicb.2022.891548] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 06/07/2022] [Indexed: 11/13/2022] Open
Abstract
The emergence of new antimicrobial resistant and virulent bacterial strains may pose a threat to human and animal health. Bacterial plasmid conjugation is a significant contributor to rapid microbial evolutions that results in the emergence and spread of antimicrobial resistance (AR). The gut of animals is believed to be a potent reservoir for the spread of AR and virulence genes through the horizontal exchange of mobile genetic elements such as plasmids. The study of the plasmid transfer process in the complex gut environment is limited due to the confounding factors that affect colonization, persistence, and plasmid conjugation. Furthermore, study of plasmid transfer in the gut of humans is limited to observational studies, leading to the need to identify alternate models that provide insight into the factors regulating conjugation in the gut. This review discusses key studies on the current models for in silico, in vitro, and in vivo modeling of bacterial conjugation, and their ability to reflect the gut of animals. We particularly emphasize the use of computational and in vitro models that may approximate aspects of the gut, as well as animal models that represent in vivo conditions to a greater extent. Directions on future research studies in the field are provided.
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Affiliation(s)
- Logan C. Ott
- Department of Food Science and Human Nutrition, Iowa State University, Ames, IA, United States
- Interdepartmental Microbiology Graduate Program, Iowa State University, Ames, IA, United States
| | - Melha Mellata
- Department of Food Science and Human Nutrition, Iowa State University, Ames, IA, United States
- Interdepartmental Microbiology Graduate Program, Iowa State University, Ames, IA, United States
- *Correspondence: Melha Mellata,
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27
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Zheng W, Zhao S, Yin Y, Zhang H, Needham DM, Evans ED, Dai CL, Lu PJ, Alm EJ, Weitz DA. High-throughput, single-microbe genomics with strain resolution, applied to a human gut microbiome. Science 2022; 376:eabm1483. [PMID: 35653470 DOI: 10.1126/science.abm1483] [Citation(s) in RCA: 88] [Impact Index Per Article: 44.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Characterizing complex microbial communities with single-cell resolution has been a long-standing goal of microbiology. We present Microbe-seq, a high-throughput method that yields the genomes of individual microbes from complex microbial communities. We encapsulate individual microbes in droplets with microfluidics and liberate their DNA, which we then amplify, tag with droplet-specific barcodes, and sequence. We explore the human gut microbiome, sequencing more than 20,000 microbial single-amplified genomes (SAGs) from a single human donor and coassembling genomes of almost 100 bacterial species, including several with multiple subspecies strains. We use these genomes to probe microbial interactions, reconstructing the horizontal gene transfer (HGT) network and observing HGT between 92 species pairs; we also identify a significant in vivo host-phage association between crAssphage and one strain of Bacteroides vulgatus. Microbe-seq contributes high-throughput culture-free capabilities to investigate genomic blueprints of complex microbial communities with single-microbe resolution.
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Affiliation(s)
- Wenshan Zheng
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA.,Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Shijie Zhao
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.,Center for Microbiome Informatics and Therapeutics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Yehang Yin
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.,College of Computer Science and Technology, Zhejiang University, Hangzhou, Zhejiang, China
| | - Huidan Zhang
- School of Engineering and Applied Sciences (SEAS), Harvard University, Cambridge, MA, USA
| | - David M Needham
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.,Ocean Ecosystems Biology, GEOMAR, Helmholtz Centre for Ocean Research, Kiel, Germany
| | - Ethan D Evans
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.,Center for Microbiome Informatics and Therapeutics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Chengzhen L Dai
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.,Center for Microbiome Informatics and Therapeutics, Massachusetts Institute of Technology, Cambridge, MA, USA.,Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Peter J Lu
- School of Engineering and Applied Sciences (SEAS), Harvard University, Cambridge, MA, USA.,Department of Physics, Harvard University, Cambridge, MA, USA
| | - Eric J Alm
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.,Center for Microbiome Informatics and Therapeutics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - David A Weitz
- School of Engineering and Applied Sciences (SEAS), Harvard University, Cambridge, MA, USA.,Department of Physics, Harvard University, Cambridge, MA, USA.,Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, USA
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28
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Baaziz H, Baker ZR, Franklin HC, Hsu BB. Rehabilitation of a misbehaving microbiome: phages for the remodeling of bacterial composition and function. iScience 2022; 25:104146. [PMID: 35402871 PMCID: PMC8991392 DOI: 10.1016/j.isci.2022.104146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
The human gut microbiota is considered an adjunct metabolic organ owing to its health impact. Recent studies have shown correlations between gut phage composition and host health. Whereas phage therapy has popularized virulent phages as antimicrobials, both virulent and temperate phages have a natural ecological relationship with their cognate bacteria. Characterization of this evolutionary coadaptation has led to other emergent therapeutic phage applications that do not necessarily rely on bacterial eradication or target pathogens. Here, we present an overview of the tripartite relationship between phages, bacteria, and the mammalian host, and highlight applications of the wildtype and genetically engineered phage for gut microbiome remodeling. In light of new and varied strategies, we propose to categorize phage applications aiming to modulate bacterial composition or function as "phage rehabilitation." By delineating phage rehab from phage therapy, we believe it will enable greater nuance and understanding of these new phage-based technologies.
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Affiliation(s)
- Hiba Baaziz
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Zachary Robert Baker
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Hollyn Claire Franklin
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Bryan Boen Hsu
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
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29
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Strain-level characterization of broad host range mobile genetic elements transferring antibiotic resistance from the human microbiome. Nat Commun 2022; 13:1445. [PMID: 35301310 PMCID: PMC8931123 DOI: 10.1038/s41467-022-29096-9] [Citation(s) in RCA: 58] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 02/22/2022] [Indexed: 12/20/2022] Open
Abstract
Mobile genetic elements (MGEs) carrying antibiotic resistance genes (ARGs) disseminate ARGs when they mobilise into new bacterial hosts. The nature of such horizontal gene transfer (HGT) events between human gut commensals and pathogens remain poorly characterised. Here, we compare 1354 cultured commensal strains (540 species) to 45,403 pathogen strains (12 species) and find 64,188 MGE-mediated ARG transfer events between the two groups using established methods. Among the 5931 MGEs, we find 15 broad host range elements predicted to have crossed different bacterial phyla while also occurring in animal and environmental microbiomes. We experimentally demonstrate that predicted broad host range MGEs can mobilise from commensals Dorea longicatena and Hungatella hathewayi to pathogen Klebsiella oxytoca, crossing phyla simultaneously. Our work establishes the MGE-mediated ARG dissemination network between human gut commensals and pathogens and highlights broad host range MGEs as targets for future ARG dissemination management.
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30
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Dufault-Thompson K, Hall B, Jiang X. Taxonomic distribution and evolutionary analysis of the equol biosynthesis gene cluster. BMC Genomics 2022; 23:182. [PMID: 35247986 PMCID: PMC8898433 DOI: 10.1186/s12864-022-08426-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 02/28/2022] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Equol, an isoflavonoid metabolite with possible health benefits in humans, is known to be produced by some human gut bacteria. While the genes encoding the equol production pathway have been characterized in a few bacterial strains, a systematic analysis of the equol production pathway is currently lacking.
Results
This study presents an analysis of the taxonomic distribution and evolutionary history of the gene cluster encoding the equol production pathway. A survey for equol gene clusters within the Genome Taxonomy Database bacterial genomes and human gut metagenomes resulted in the identification of a highly conserved gene cluster found in nine bacterial species from the Eggerthellaceae family. The identified gene clusters from human gut metagenomes revealed potential variations in the equol gene cluster organization and gene content within the equol-producing Eggerthellaceae clades. Subsequent analysis showed that in addition to the four genes directly involved in equol production, multiple other genes were consistently found in the equol gene clusters. These genes were predicted to encode a putative electron transport complex and hydrogenase maturase system, suggesting potential roles for them in the equol production pathway. Analysis of the gene clusters and a phylogenetic reconstruction of a putative NAD kinase gene provided evidence of the recent transfer of the equol gene cluster from a basal Eggerthellaceae species to Slackia_A equolifaciens, Enteroscipio sp000270285, and Lactococcus garvieae 20–92.
Conclusions
This analysis demonstrates that the highly conserved equol gene cluster is taxonomically restricted to the Eggerthellaceae family of bacteria and provides evidence of the role of horizontal gene transfer in the evolutionary history of these genes. These results provide a foundation for future studies of equol production in the human gut and future efforts related to bioengineering and the use of equol-producing bacteria as probiotics.
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31
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Dai D, Brown C, Bürgmann H, Larsson DGJ, Nambi I, Zhang T, Flach CF, Pruden A, Vikesland PJ. Long-read metagenomic sequencing reveals shifts in associations of antibiotic resistance genes with mobile genetic elements from sewage to activated sludge. MICROBIOME 2022; 10:20. [PMID: 35093160 PMCID: PMC8801152 DOI: 10.1186/s40168-021-01216-5] [Citation(s) in RCA: 49] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 12/13/2021] [Indexed: 05/10/2023]
Abstract
BACKGROUND There is concern that the microbially rich activated sludge environment of wastewater treatment plants (WWTPs) may contribute to the dissemination of antibiotic resistance genes (ARGs). We applied long-read (nanopore) sequencing to profile ARGs and their neighboring genes to illuminate their fate in the activated sludge treatment by comparing their abundance, genetic locations, mobility potential, and bacterial hosts within activated sludge relative to those in influent sewage across five WWTPs from three continents. RESULTS The abundances (gene copies per Gb of reads, aka gc/Gb) of all ARGs and those carried by putative pathogens decreased 75-90% from influent sewage (192-605 gc/Gb) to activated sludge (31-62 gc/Gb) at all five WWTPs. Long reads enabled quantification of the percent abundance of ARGs with mobility potential (i.e., located on plasmids or co-located with other mobile genetic elements (MGEs)). The abundance of plasmid-associated ARGs decreased at four of five WWTPs (from 40-73 to 31-68%), and ARGs co-located with transposable, integrative, and conjugative element hallmark genes showed similar trends. Most ARG-associated elements decreased 0.35-13.52% while integrative and transposable elements displayed slight increases at two WWTPs (1.4-2.4%). While resistome and taxonomic compositions both shifted significantly, host phyla for chromosomal ARG classes remained relatively consistent, indicating vertical gene transfer via active biomass growth in activated sludge as the key pathway of chromosomal ARG dissemination. CONCLUSIONS Overall, our results suggest that the activated sludge process acted as a barrier against the proliferation of most ARGs, while those that persisted or increased warrant further attention. Video abstract.
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Affiliation(s)
- Dongjuan Dai
- Department of Civil and Environmental Engineering, Virginia Polytechnic and State University, Blacksburg, VA, USA
| | - Connor Brown
- Department of Genetics, Bioinformatics, and Computational Biology, Virginia Polytechnic and State University, Blacksburg, VA, USA
| | - Helmut Bürgmann
- Eawag: Swiss Federal Institute of Aquatic Science and Technology, Kastanienbaum, Switzerland
| | - D G Joakim Larsson
- Institute of Biomedicine, Department of Infectious Diseases, University of Gothenburg, Gothenburg, Sweden
- Centre for Antibiotic Resistance Research (CARe), University of Gothenburg, Gothenburg, Sweden
| | - Indumathi Nambi
- Department of Civil Engineering, Indian Institute of Technology, Madras, India
| | - Tong Zhang
- Department of Civil Engineering, The University of Hong Kong, Hong Kong SAR, China
| | - Carl-Fredrik Flach
- Institute of Biomedicine, Department of Infectious Diseases, University of Gothenburg, Gothenburg, Sweden
- Centre for Antibiotic Resistance Research (CARe), University of Gothenburg, Gothenburg, Sweden
| | - Amy Pruden
- Department of Civil and Environmental Engineering, Virginia Polytechnic and State University, Blacksburg, VA, USA.
| | - Peter J Vikesland
- Department of Civil and Environmental Engineering, Virginia Polytechnic and State University, Blacksburg, VA, USA.
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32
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Yan W, Hall AB, Jiang X. Bacteroidales species in the human gut are a reservoir of antibiotic resistance genes regulated by invertible promoters. NPJ Biofilms Microbiomes 2022; 8:1. [PMID: 35013297 PMCID: PMC8748976 DOI: 10.1038/s41522-021-00260-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 11/26/2021] [Indexed: 12/21/2022] Open
Abstract
Antibiotic-resistance genes (ARGs) regulated by invertible promoters can mitigate the fitness cost of maintaining ARGs in the absence of antibiotics and could potentially prolong the persistence of ARGs in bacterial populations. However, the origin, prevalence, and distribution of these ARGs regulated by invertible promoters remains poorly understood. Here, we sought to assess the threat posed by ARGs regulated by invertible promoters by systematically searching for ARGs regulated by invertible promoters in the human gut microbiome and examining their origin, prevalence, and distribution. Through metagenomic assembly of 2227 human gut metagenomes and genomic analysis of the Unified Human Gastrointestinal Genome (UHGG) collection, we identified ARGs regulated by invertible promoters and categorized them into three classes based on the invertase-regulating phase variation. In the human gut microbiome, ARGs regulated by invertible promoters are exclusively found in Bacteroidales species. Through genomic analysis, we observed that ARGs regulated by invertible promoters have convergently originated from ARG insertions into glycan-synthesis loci that were regulated by invertible promoters at least three times. Moreover, all three classes of invertible promoters regulating ARGs are located within integrative conjugative elements (ICEs). Therefore, horizontal transfer via ICEs could explain the wide taxonomic distribution of ARGs regulated by invertible promoters. Overall, these findings reveal that glycan-synthesis loci regulated by invertible promoters in Bacteroidales species are an important hotspot for the emergence of clinically-relevant ARGs regulated by invertible promoters.
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Affiliation(s)
- Wei Yan
- National Library of Medicine, National Institutes of Health, Bethesda, Maryland, USA
| | - A Brantley Hall
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland, USA
- Center for Bioinformatics and Computational Biology, University of Maryland, College Park, Maryland, USA
| | - Xiaofang Jiang
- National Library of Medicine, National Institutes of Health, Bethesda, Maryland, USA.
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33
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Cargo Genes of Tn 7-Like Transposons Comprise an Enormous Diversity of Defense Systems, Mobile Genetic Elements, and Antibiotic Resistance Genes. mBio 2021; 12:e0293821. [PMID: 34872347 PMCID: PMC8649781 DOI: 10.1128/mbio.02938-21] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Transposition is a major mechanism of horizontal gene mobility in prokaryotes. However, exploration of the genes mobilized by transposons (cargo) is hampered by the difficulty in delineating integrated transposons from their surrounding genetic context. Here, we present a computational approach that allowed us to identify the boundaries of 6,549 Tn7-like transposons. We found that 96% of these transposons carry at least one cargo gene. Delineation of distinct communities in a gene-sharing network demonstrates how transposons function as a conduit of genes between phylogenetically distant hosts. Comparative analysis of the cargo genes reveals significant enrichment of mobile genetic elements (MGEs) nested within Tn7-like transposons, such as insertion sequences and toxin-antitoxin modules, and of genes involved in recombination, anti-MGE defense, and antibiotic resistance. More unexpectedly, cargo also includes genes encoding central carbon metabolism enzymes. Twenty-two Tn7-like transposons carry both an anti-MGE defense system and antibiotic resistance genes, illustrating how bacteria can overcome these combined pressures upon acquisition of a single transposon. This work substantially expands the distribution of Tn7-like transposons, defines their evolutionary relationships, and provides a large-scale functional classification of prokaryotic genes mobilized by transposition.
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34
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Zhang AN, Gaston JM, Dai CL, Zhao S, Poyet M, Groussin M, Yin X, Li LG, van Loosdrecht MCM, Topp E, Gillings MR, Hanage WP, Tiedje JM, Moniz K, Alm EJ, Zhang T. An omics-based framework for assessing the health risk of antimicrobial resistance genes. Nat Commun 2021; 12:4765. [PMID: 34362925 PMCID: PMC8346589 DOI: 10.1038/s41467-021-25096-3] [Citation(s) in RCA: 256] [Impact Index Per Article: 85.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Accepted: 07/23/2021] [Indexed: 12/24/2022] Open
Abstract
Antibiotic resistance genes (ARGs) are widespread among bacteria. However, not all ARGs pose serious threats to public health, highlighting the importance of identifying those that are high-risk. Here, we developed an ‘omics-based’ framework to evaluate ARG risk considering human-associated-enrichment, gene mobility, and host pathogenicity. Our framework classifies human-associated, mobile ARGs (3.6% of all ARGs) as the highest risk, which we further differentiate as ‘current threats’ (Rank I; 3%) - already present among pathogens - and ‘future threats’ (Rank II; 0.6%) - novel resistance emerging from non-pathogens. Our framework identified 73 ‘current threat’ ARG families. Of these, 35 were among the 37 high-risk ARGs proposed by the World Health Organization and other literature; the remaining 38 were significantly enriched in hospital plasmids. By evaluating all pathogen genomes released since framework construction, we confirmed that ARGs that recently transferred into pathogens were significantly enriched in Rank II (‘future threats’). Lastly, we applied the framework to gut microbiome genomes from fecal microbiota transplantation donors. We found that although ARGs were widespread (73% of genomes), only 8.9% of genomes contained high-risk ARGs. Our framework provides an easy-to-implement approach to identify current and future antimicrobial resistance threats, with potential clinical applications including reducing risk of microbiome-based interventions. Antibiotic resistance genes are common but not all are of high risk to human health. Here, the authors develop an omics-based framework for ranking genes by risk that incorporates level of enrichment in human associated environments, gene mobility, and host pathogenicity.
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Affiliation(s)
- An-Ni Zhang
- Environmental Microbiome Engineering and Biotechnology Laboratory, Department of Civil Engineering, The University of Hong Kong, Hong Kong SAR, China.,Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, USA
| | | | - Chengzhen L Dai
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, USA
| | - Shijie Zhao
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, USA
| | - Mathilde Poyet
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, USA.,Center for Microbiome Informatics and Therapeutics, Massachusetts Institute of Technology, Cambridge, USA.,The Broad Institute of MIT and Harvard, Cambridge, USA
| | - Mathieu Groussin
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, USA.,Center for Microbiome Informatics and Therapeutics, Massachusetts Institute of Technology, Cambridge, USA.,The Broad Institute of MIT and Harvard, Cambridge, USA
| | - Xiaole Yin
- Environmental Microbiome Engineering and Biotechnology Laboratory, Department of Civil Engineering, The University of Hong Kong, Hong Kong SAR, China
| | - Li-Guan Li
- Environmental Microbiome Engineering and Biotechnology Laboratory, Department of Civil Engineering, The University of Hong Kong, Hong Kong SAR, China
| | | | - Edward Topp
- London Research and Development Centre (LRDC), Agriculture and Agri-Food Canada, London, ON, Canada
| | - Michael R Gillings
- Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia
| | - William P Hanage
- Center for Communicable Disease Dynamics, Department of Epidemiology, Harvard TH Chan School of Public Health, Boston, USA
| | - James M Tiedje
- Department of Plant, Soil and Microbial Sciences and of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA
| | - Katya Moniz
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, USA
| | - Eric J Alm
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, USA.,Center for Microbiome Informatics and Therapeutics, Massachusetts Institute of Technology, Cambridge, USA.,The Broad Institute of MIT and Harvard, Cambridge, USA
| | - Tong Zhang
- Environmental Microbiome Engineering and Biotechnology Laboratory, Department of Civil Engineering, The University of Hong Kong, Hong Kong SAR, China. .,School of Public Health, The University of Hong Kong, Hong Kong SAR, China. .,Center for Environmental Engineering Research, The University of Hong Kong, Hong Kong SAR, China.
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Abstract
Bacteria acquire novel DNA through horizontal gene transfer (HGT), a process that enables an organism to rapidly adapt to changing environmental conditions, provides a competitive edge and potentially alters its relationship with its host. Although the HGT process is routinely exploited in laboratories, there is a surprising disconnect between what we know from laboratory experiments and what we know from natural environments, such as the human gut microbiome. Owing to a suite of newly available computational algorithms and experimental approaches, we have a broader understanding of the genes that are being transferred and are starting to understand the ecology of HGT in natural microbial communities. This Review focuses on these new technologies, the questions they can address and their limitations. As these methods are applied more broadly, we are beginning to recognize the full extent of HGT possible within a microbiome and the punctuated dynamics of HGT, specifically in response to external stimuli. Furthermore, we are better characterizing the complex selective pressures on mobile genetic elements and the mechanisms by which they interact with the bacterial host genome.
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Affiliation(s)
- Ilana Lauren Brito
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA.
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36
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N'Guessan A, Brito IL, Serohijos AWR, Shapiro BJ. Mobile Gene Sequence Evolution within Individual Human Gut Microbiomes Is Better Explained by Gene-Specific Than Host-Specific Selective Pressures. Genome Biol Evol 2021; 13:6300526. [PMID: 34132784 PMCID: PMC8358218 DOI: 10.1093/gbe/evab142] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/10/2021] [Indexed: 01/03/2023] Open
Abstract
Pangenomes—the cumulative set of genes encoded by a population or species—arise from the interplay of horizontal gene transfer, drift, and selection. The balance of these forces in shaping pangenomes has been debated, and studies to date focused on ancient evolutionary time scales have suggested that pangenomes generally confer niche adaptation to their bacterial hosts. To shed light on pangenome evolution on shorter evolutionary time scales, we inferred the selective pressures acting on mobile genes within individual human microbiomes from 176 Fiji islanders. We mapped metagenomic sequence reads to a set of known mobile genes to identify single nucleotide variants (SNVs) and calculated population genetic metrics to infer deviations from a neutral evolutionary model. We found that mobile gene sequence evolution varied more by gene family than by human social attributes, such as household or village. Patterns of mobile gene sequence evolution could be qualitatively recapitulated with a simple evolutionary simulation without the need to invoke the adaptive value of mobile genes to either bacterial or human hosts. These results stand in contrast with the apparent adaptive value of pangenomes over longer evolutionary time scales. In general, the most highly mobile genes (i.e., those present in more distinct bacterial host genomes) tend to have higher metagenomic read coverage and an excess of low-frequency SNVs, consistent with their rapid spread across multiple bacterial species in the gut. However, a subset of mobile genes—including those involved in defense mechanisms and secondary metabolism—showed a contrasting signature of intermediate-frequency SNVs, indicating species-specific selective pressures or negative frequency-dependent selection on these genes. Together, our evolutionary models and population genetic data show that gene-specific selective pressures predominate over human or bacterial host-specific pressures during the relatively short time scales of a human lifetime.
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Affiliation(s)
- Arnaud N'Guessan
- Departement de Biochimie, Université de Montréal, Québec, Canada.,Centre Robert-Cedergren en Bio-informatique et Génomique, Université de Montréal, Québec, Canada
| | - Ilana Lauren Brito
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York, USA
| | - Adrian W R Serohijos
- Departement de Biochimie, Université de Montréal, Québec, Canada.,Centre Robert-Cedergren en Bio-informatique et Génomique, Université de Montréal, Québec, Canada
| | - B Jesse Shapiro
- Département de Sciences Biologiques, Complexe des Sciences, Université de Montréal, Québec, Canada.,Department of Microbiology and Immunology, McGill University, Montreal, Québec, Canada.,McGill Genome Centre, Montreal, Québec, Canada
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37
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García-Bayona L, Coyne MJ, Comstock LE. Mobile Type VI secretion system loci of the gut Bacteroidales display extensive intra-ecosystem transfer, multi-species spread and geographical clustering. PLoS Genet 2021; 17:e1009541. [PMID: 33901198 PMCID: PMC8102008 DOI: 10.1371/journal.pgen.1009541] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 05/06/2021] [Accepted: 04/08/2021] [Indexed: 02/07/2023] Open
Abstract
The human gut microbiota is a dense microbial ecosystem with extensive opportunities for bacterial contact-dependent processes such as conjugation and Type VI secretion system (T6SS)-dependent antagonism. In the gut Bacteroidales, two distinct genetic architectures of T6SS loci, GA1 and GA2, are contained on Integrative and Conjugative Elements (ICE). Despite intense interest in the T6SSs of the gut Bacteroidales, there is only a superficial understanding of their evolutionary patterns, and of their dissemination among Bacteroidales species in human gut communities. Here, we combine extensive genomic and metagenomic analyses to better understand their ecological and evolutionary dynamics. We identify new genetic subtypes, document extensive intrapersonal transfer of these ICE to Bacteroidales species within human gut microbiomes, and most importantly, reveal frequent population fixation of these newly armed strains in multiple species within a person. We further show the distribution of each of the distinct T6SSs in human populations and show there is geographical clustering. We reveal that the GA1 T6SS ICE integrates at a minimal recombination site leading to their integration throughout genomes and their frequent interruption of genes, whereas the GA2 T6SS ICE integrate at one of three different tRNA genes. The exclusion of concurrent GA1 and GA2 T6SSs in individual strains is associated with intact T6SS loci and with an ICE-encoded gene. By performing a comprehensive analysis of mobile genetic elements (MGE) in co-resident Bacteroidales species in numerous human gut communities, we identify 74 MGE that transferred to multiple Bacteroidales species within individual gut microbiomes. We further show that only three other MGE demonstrate multi-species spread in human gut microbiomes to the degree demonstrated by the GA1 and GA2 ICE. These data underscore the ubiquity and dissemination of mobile T6SS loci within Bacteroidales communities and across human populations.
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Affiliation(s)
- Leonor García-Bayona
- Division of Infectious Diseases, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Michael J. Coyne
- Division of Infectious Diseases, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Laurie E. Comstock
- Division of Infectious Diseases, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
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38
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Zünd M, Ruscheweyh HJ, Field CM, Meyer N, Cuenca M, Hoces D, Hardt WD, Sunagawa S. High throughput sequencing provides exact genomic locations of inducible prophages and accurate phage-to-host ratios in gut microbial strains. MICROBIOME 2021; 9:77. [PMID: 33781335 PMCID: PMC8008629 DOI: 10.1186/s40168-021-01033-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 02/09/2021] [Indexed: 05/17/2023]
Abstract
BACKGROUND Temperate phages influence the density, diversity and function of bacterial populations. Historically, they have been described as carriers of toxins. More recently, they have also been recognised as direct modulators of the gut microbiome, and indirectly of host health and disease. Despite recent advances in studying prophages using non-targeted sequencing approaches, methodological challenges in identifying inducible prophages in bacterial genomes and quantifying their activity have limited our understanding of prophage-host interactions. RESULTS We present methods for using high-throughput sequencing data to locate inducible prophages, including those previously undiscovered, to quantify prophage activity and to investigate their replication. We first used the well-established Salmonella enterica serovar Typhimurium/p22 system to validate our methods for (i) quantifying phage-to-host ratios and (ii) accurately locating inducible prophages in the reference genome based on phage-to-host ratio differences and read alignment alterations between induced and non-induced prophages. Investigating prophages in bacterial strains from a murine gut model microbiota known as Oligo-MM12 or sDMDMm2, we located five novel inducible prophages in three strains, quantified their activity and showed signatures of lateral transduction potential for two of them. Furthermore, we show that the methods were also applicable to metagenomes of induced faecal samples from Oligo-MM12 mice, including for strains with a relative abundance below 1%, illustrating its potential for the discovery of inducible prophages also in more complex metagenomes. Finally, we show that predictions of prophage locations in reference genomes of the strains we studied were variable and inconsistent for four bioinformatic tools we tested, which highlights the importance of their experimental validation. CONCLUSIONS This study demonstrates that the integration of experimental induction and bioinformatic analysis presented here is a powerful approach to accurately locate inducible prophages using high-throughput sequencing data and to quantify their activity. The ability to generate such quantitative information will be critical in helping us to gain better insights into the factors that determine phage activity and how prophage-bacteria interactions influence our microbiome and impact human health. Video abstract.
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Affiliation(s)
- Mirjam Zünd
- Department of Biology, Institute of Microbiology and Swiss Institute of Bioinformatics, ETH Zürich, Zürich, Switzerland
| | - Hans-Joachim Ruscheweyh
- Department of Biology, Institute of Microbiology and Swiss Institute of Bioinformatics, ETH Zürich, Zürich, Switzerland
| | - Christopher M. Field
- Department of Biology, Institute of Microbiology and Swiss Institute of Bioinformatics, ETH Zürich, Zürich, Switzerland
| | - Natalie Meyer
- Department of Biology, Institute of Microbiology and Swiss Institute of Bioinformatics, ETH Zürich, Zürich, Switzerland
| | - Miguelangel Cuenca
- Department of Biology, Institute of Microbiology and Swiss Institute of Bioinformatics, ETH Zürich, Zürich, Switzerland
| | - Daniel Hoces
- Department of Health Sciences and Technology, Institute of Food, Nutrition and Health, ETH Zürich, Zürich, Switzerland
| | - Wolf-Dietrich Hardt
- Department of Biology, Institute of Microbiology and Swiss Institute of Bioinformatics, ETH Zürich, Zürich, Switzerland
| | - Shinichi Sunagawa
- Department of Biology, Institute of Microbiology and Swiss Institute of Bioinformatics, ETH Zürich, Zürich, Switzerland
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39
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The shared resistome of human and pig microbiota is mobilized by distinct genetic elements. Appl Environ Microbiol 2021; 87:AEM.01910-20. [PMID: 33310720 PMCID: PMC8090867 DOI: 10.1128/aem.01910-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The extensive use of antibiotics in hospitals and in the animal breeding industry has promoted antibiotic resistance in bacteria, which resulted in the emergence of a large number of antibiotic resistance genes in the intestinal tract of human and farmed animals. Genetic exchange of resistance genes between the two ecosystems is now well documented for pathogenic bacteria, but the repertoire of shared resistance genes in the commensal bacterial community and by which genetic modules they are disseminated are still unclear. By analyzing metagenomics data of human and pig intestinal samples both collected in Shenzhen, China, a set of 27 highly prevalent antibiotic resistance genes was found to be shared between human and pig intestinal microbiota. The mobile genetic context for 11 of these core antibiotic resistance genes could be identified by mining their carrying scaffolds constructed from the two datasets, leading to the detection of seven integrative and conjugative/mobilizable elements and two IS-related transposons. The comparison of the relative abundances between these detected mobile genetic elements and their associated antibiotic resistance genes revealed that for many genes, the estimated contribution of the mobile elements to the gene abundance differs strikingly depending on the host. These findings indicate that although some antibiotic resistance genes are ubiquitous across microbiota of human and pig populations, they probably relied on different genetic elements for their dissemination within each population.IMPORTANCE There is growing concern that antibiotic resistance genes could spread from the husbandry environment to human pathogens through dissemination mediated by mobile genetic elements. In this study, we investigated the contribution of mobile genetic elements to the abundance of highly prevalent antibiotic resistance genes found in commensal bacteria of both human and pig intestinal microbiota originating from the same region. Our results reveal that for most of these antibiotic resistance genes, the abundance is not explained by the same mobile genetic element in each host, suggesting that the human and pig microbial communities promoted a different set of mobile genetic carriers for the same antibiotic resistance genes. These results deepen our understanding of the dissemination of antibiotic resistance genes among and between human and pig gut microbiota.
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40
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Camarillo-Guerrero LF, Almeida A, Rangel-Pineros G, Finn RD, Lawley TD. Massive expansion of human gut bacteriophage diversity. Cell 2021; 184:1098-1109.e9. [PMID: 33606979 PMCID: PMC7895897 DOI: 10.1016/j.cell.2021.01.029] [Citation(s) in RCA: 268] [Impact Index Per Article: 89.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 11/02/2020] [Accepted: 01/19/2021] [Indexed: 12/25/2022]
Abstract
Bacteriophages drive evolutionary change in bacterial communities by creating gene flow networks that fuel ecological adaptions. However, the extent of viral diversity and its prevalence in the human gut remains largely unknown. Here, we introduce the Gut Phage Database, a collection of ∼142,000 non-redundant viral genomes (>10 kb) obtained by mining a dataset of 28,060 globally distributed human gut metagenomes and 2,898 reference genomes of cultured gut bacteria. Host assignment revealed that viral diversity is highest in the Firmicutes phyla and that ∼36% of viral clusters (VCs) are not restricted to a single species, creating gene flow networks across phylogenetically distinct bacterial species. Epidemiological analysis uncovered 280 globally distributed VCs found in at least 5 continents and a highly prevalent phage clade with features reminiscent of p-crAssphage. This high-quality, large-scale catalog of phage genomes will improve future virome studies and enable ecological and evolutionary analysis of human gut bacteriophages.
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Affiliation(s)
- Luis F Camarillo-Guerrero
- Host-Microbiota Interactions Laboratory, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton CB10 1SA, UK.
| | - Alexandre Almeida
- European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Hinxton CB10 1SA, UK; Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton CB10 1SA, UK
| | - Guillermo Rangel-Pineros
- European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Hinxton CB10 1SA, UK; Max Planck Tandem Group in Computational Biology, Department of Biological Sciences, Universidad de los Andes, Bogota 111711, Colombia
| | - Robert D Finn
- European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Hinxton CB10 1SA, UK
| | - Trevor D Lawley
- Host-Microbiota Interactions Laboratory, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton CB10 1SA, UK.
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41
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Ruiz-Roldán L, de Toro M, Sáenz Y. Whole Genome Analysis of Environmental Pseudomonas mendocina Strains: Virulence Mechanisms and Phylogeny. Genes (Basel) 2021; 12:115. [PMID: 33477842 PMCID: PMC7832885 DOI: 10.3390/genes12010115] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 01/10/2021] [Accepted: 01/16/2021] [Indexed: 12/15/2022] Open
Abstract
Pseudomonas mendocina is an environmental bacterium, rarely isolated in clinical specimens, although it has been described as producing endocarditis and sepsis. Little is known about its genome. Whole genome sequencing can be used to learn about the phylogeny, evolution, or pathogenicity of these isolates. Thus, the aim of this study was to analyze the resistome, virulome, and phylogenetic relationship of two P. mendocina strains, Ps542 and Ps799, isolated from a healthy Anas platyrhynchos fecal sample and a lettuce, respectively. Among all of the small number of P.mendocina genomes available in the National Center for Biotechnology Information (NCBI) repository, both strains were placed within one of two well-defined phylogenetic clusters. Both P. mendocina strains lacked antimicrobial resistance genes, but the Ps799 genome showed a MOBP3 family relaxase. Nevertheless, this study revealed that P. mendocina possesses an important number of virulence factors, including a leukotoxin, flagella, pili, and the Type 2 and Type 6 Secretion Systems, that could be responsible for their pathogenesis. More phenotypical and in vivo studies are needed to deepen the association with human infections and the potential P. mendocina pathogenicity.
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Affiliation(s)
- Lidia Ruiz-Roldán
- Área de Microbiología Molecular, Centro de Investigación Biomédica de La Rioja (CIBIR), C/Piqueras 98, 26006 Logroño, Spain;
| | - María de Toro
- Plataforma de Genómica y Bioinformática, Centro de Investigación Biomédica de La Rioja (CIBIR), C/Piqueras 98, 26006 Logroño, Spain
| | - Yolanda Sáenz
- Área de Microbiología Molecular, Centro de Investigación Biomédica de La Rioja (CIBIR), C/Piqueras 98, 26006 Logroño, Spain;
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42
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Boopathi S, Liu D, Jia AQ. Molecular trafficking between bacteria determines the shape of gut microbial community. Gut Microbes 2021; 13:1959841. [PMID: 34455923 PMCID: PMC8432619 DOI: 10.1080/19490976.2021.1959841] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Revised: 07/08/2021] [Accepted: 07/14/2021] [Indexed: 02/04/2023] Open
Abstract
Complex inter-bacterial interactions largely influence the structure and function of the gut microbial community. Though several host-associated phenomena have often been shown to be involved in the stability, structure, and function of the gut microbial community, the implication of contact-dependent and contact-independent inter-bacterial interactions has been overlooked. Such interactions are tightly governed at multiple layers through several extracellular organelles, including contact-dependent inhibition (CDI), nanotubes, type VI secretion system (T6SS), and membrane vesicles (MVs). Recent advancements in molecular techniques have revealed that such extracellular organelles function beyond exhibiting competitive behavior and are also involved in manifesting cooperative behaviors. Cooperation between bacteria occurs through the sharing of several beneficial molecules including nucleic acids, proteins, metabolites, and nutrients among the members of the community, while competition occurs by means of multiple toxins. Intrinsic coordination between contact-dependent and contact-independent mechanisms collectively provides a fitness advantage and increased colonization resistance to the gut microbiota, where molecular trafficking plays a key role. This review is intended to provide a comprehensive view of the salient features of the different bacterial interactions and to highlight how microbiota deploy multifaceted organelles, for exerting both cooperative and competitive behaviors. We discuss the current knowledge of bacterial molecular trafficking and its impact on shaping the gut microbial community.
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Affiliation(s)
- Seenivasan Boopathi
- School of Life and Pharmaceutical Sciences, Key Laboratory of Tropical Biological Resources of Ministry Education, State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, China
| | - Danrui Liu
- School of Life and Pharmaceutical Sciences, Key Laboratory of Tropical Biological Resources of Ministry Education, State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, China
| | - Ai-Qun Jia
- School of Life and Pharmaceutical Sciences, Key Laboratory of Tropical Biological Resources of Ministry Education, State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, China
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43
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Glowacki RWP, Martens EC. If you eat it, or secrete it, they will grow: the expanding list of nutrients utilized by human gut bacteria. J Bacteriol 2020; 203:JB.00481-20. [PMID: 33168637 PMCID: PMC8092160 DOI: 10.1128/jb.00481-20] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
In order to persist, successful bacterial inhabitants of the human gut need to adapt to changing nutrient conditions, which are influenced by host diet and a variety of other factors. For members of the Bacteroidetes and several other phyla, this has resulted in diversification of a variety of enzyme-based systems that equip them to sense and utilize carbohydrate-based nutrients from host, diet, and bacterial origin. In this review, we focus first on human gut Bacteroides and describe recent findings regarding polysaccharide utilization loci (PULs) and the mechanisms of the multi-protein systems they encode, including their regulation and the expanding diversity of substrates that they target. Next, we highlight previously understudied substrates such as monosaccharides, nucleosides, and Maillard reaction products that can also affect the gut microbiota by feeding symbionts that possess specific systems for their metabolism. Since some pathogens preferentially utilize these nutrients, they may represent nutrient niches competed for by commensals and pathogens. Finally, we address recent work to describe nutrient acquisition mechanisms in other important gut species such as those belonging to the Gram-positive anaerobic phyla Actinobacteria and Firmicutes, as well as the Proteobacteria Because gut bacteria contribute to many aspects of health and disease, we showcase advances in the field of synthetic biology, which seeks to engineer novel, diet-controlled nutrient utilization pathways within gut symbionts to create rationally designed live therapeutics.
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Affiliation(s)
- Robert W. P. Glowacki
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Eric C. Martens
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
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44
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Saak CC, Dinh CB, Dutton RJ. Experimental approaches to tracking mobile genetic elements in microbial communities. FEMS Microbiol Rev 2020; 44:606-630. [PMID: 32672812 PMCID: PMC7476777 DOI: 10.1093/femsre/fuaa025] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 06/29/2020] [Indexed: 12/19/2022] Open
Abstract
Horizontal gene transfer is an important mechanism of microbial evolution and is often driven by the movement of mobile genetic elements between cells. Due to the fact that microbes live within communities, various mechanisms of horizontal gene transfer and types of mobile elements can co-occur. However, the ways in which horizontal gene transfer impacts and is impacted by communities containing diverse mobile elements has been challenging to address. Thus, the field would benefit from incorporating community-level information and novel approaches alongside existing methods. Emerging technologies for tracking mobile elements and assigning them to host organisms provide promise for understanding the web of potential DNA transfers in diverse microbial communities more comprehensively. Compared to existing experimental approaches, chromosome conformation capture and methylome analyses have the potential to simultaneously study various types of mobile elements and their associated hosts. We also briefly discuss how fermented food microbiomes, given their experimental tractability and moderate species complexity, make ideal models to which to apply the techniques discussed herein and how they can be used to address outstanding questions in the field of horizontal gene transfer in microbial communities.
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Affiliation(s)
- Christina C Saak
- Division of Biological Sciences, Section of Molecular Biology, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Cong B Dinh
- Division of Biological Sciences, Section of Molecular Biology, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Rachel J Dutton
- Division of Biological Sciences, Section of Molecular Biology, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
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45
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Widespread transfer of mobile antibiotic resistance genes within individual gut microbiomes revealed through bacterial Hi-C. Nat Commun 2020; 11:4379. [PMID: 32873785 PMCID: PMC7463002 DOI: 10.1038/s41467-020-18164-7] [Citation(s) in RCA: 94] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 08/06/2020] [Indexed: 01/13/2023] Open
Abstract
The gut microbiome harbors a ‘silent reservoir’ of antibiotic resistance (AR) genes that is thought to contribute to the emergence of multidrug-resistant pathogens through horizontal gene transfer (HGT). To counteract the spread of AR, it is paramount to know which organisms harbor mobile AR genes and which organisms engage in HGT. Despite methods that characterize the overall abundance of AR genes in the gut, technological limitations of short-read sequencing have precluded linking bacterial taxa to specific mobile genetic elements (MGEs) encoding AR genes. Here, we apply Hi-C, a high-throughput, culture-independent method, to surveil the bacterial carriage of MGEs. We compare two healthy individuals with seven neutropenic patients undergoing hematopoietic stem cell transplantation, who receive multiple courses of antibiotics, and are acutely vulnerable to the threat of multidrug-resistant infections. We find distinct networks of HGT across individuals, though AR and mobile genes are associated with more diverse taxa within the neutropenic patients than the healthy subjects. Our data further suggest that HGT occurs frequently over a several-week period in both cohorts. Whereas most efforts to understand the spread of AR genes have focused on pathogenic species, our findings shed light on the role of the human gut microbiome in this process. Linking antibiotic resistance (AR) in the gut microbiome with their bacterial hosts remains challenging. Here, the authors apply bacterial Hi-C to map mobile genetic elements in metagenomes, and illustrate that genes are present in more diverse taxa in neutropenic patients than healthy subjects.
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Slizovskiy IB, Mukherjee K, Dean CJ, Boucher C, Noyes NR. Mobilization of Antibiotic Resistance: Are Current Approaches for Colocalizing Resistomes and Mobilomes Useful? Front Microbiol 2020; 11:1376. [PMID: 32695079 PMCID: PMC7338343 DOI: 10.3389/fmicb.2020.01376] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 05/28/2020] [Indexed: 11/16/2022] Open
Abstract
Antimicrobial resistance (AMR) poses a global human and animal health threat, and predicting AMR persistence and transmission remains an intractable challenge. Shotgun metagenomic sequencing can help overcome this by enabling characterization of AMR genes within all bacterial taxa, most of which are uncultivatable in laboratory settings. Shotgun sequencing, therefore, provides a more comprehensive glance at AMR "potential" within samples, i.e., the "resistome." However, the risk inherent within a given resistome is predicated on the genomic context of various AMR genes, including their presence within mobile genetic elements (MGEs). Therefore, resistome risk stratification can be advanced if AMR profiles are considered in light of the flanking mobilizable genomic milieu (e.g., plasmids, integrative conjugative elements (ICEs), phages, and other MGEs). Because such mediators of horizontal gene transfer (HGT) are involved in uptake by pathogens, investigators are increasingly interested in characterizing that resistome fraction in genomic proximity to HGT mediators, i.e., the "mobilome"; we term this "colocalization." We explored the utility of common colocalization approaches using alignment- and assembly-based techniques, on clinical (human) and agricultural (cattle) fecal metagenomes, obtained from antimicrobial use trials. Ordination revealed that tulathromycin-treated cattle experienced a shift in ICE and plasmid composition versus untreated animals, though the resistome was unaffected during the monitoring period. Contrarily, the human resistome and mobilome composition both shifted shortly after antimicrobial administration, though this rebounded to pre-treatment status. Bayesian networks revealed statistical AMR-MGE co-occurrence in 19 and 2% of edges from the cattle and human networks, respectively, suggesting a putatively greater mobility potential of AMR in cattle feces. Conversely, using Mobility Index (MI) and overlap analysis, abundance of de novo-assembled contigs supporting resistomes flanked by MGE increased shortly post-exposure within human metagenomes, though > 40 days after peak dose such contigs were rare (∼2%). MI was not substantially altered by antimicrobial exposure across all cattle metagenomes, ranging 0.5-4.0%. We highlight that current alignment- and assembly-based methods estimating resistome mobility yield contradictory and incomplete results, likely constrained by approach-specific data inputs, and bioinformatic limitations. We discuss recent laboratory and computational advancements that may enhance resistome risk analysis in clinical, regulatory, and commercial applications.
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Affiliation(s)
- Ilya B Slizovskiy
- Food-Centric Corridor, Infectious Disease Laboratory, Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, St. Paul, MN, United States
| | - Kingshuk Mukherjee
- Department of Computer and Information Science and Engineering, The Herbert Wertheim College of Engineering, University of Florida, Gainesville, FL, United States
| | - Christopher J Dean
- Food-Centric Corridor, Infectious Disease Laboratory, Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, St. Paul, MN, United States
| | - Christina Boucher
- Department of Computer and Information Science and Engineering, The Herbert Wertheim College of Engineering, University of Florida, Gainesville, FL, United States
| | - Noelle R Noyes
- Food-Centric Corridor, Infectious Disease Laboratory, Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, St. Paul, MN, United States
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Botelho J, Schulenburg H. The Role of Integrative and Conjugative Elements in Antibiotic Resistance Evolution. Trends Microbiol 2020; 29:8-18. [PMID: 32536522 DOI: 10.1016/j.tim.2020.05.011] [Citation(s) in RCA: 98] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 05/07/2020] [Accepted: 05/14/2020] [Indexed: 02/07/2023]
Abstract
Mobile genetic elements (MGEs), such as plasmids and integrative and conjugative elements (ICEs), are main drivers for the spread of antibiotic resistance (AR). Coevolution between bacteria and plasmids shapes the transfer and stability of plasmids across bacteria. Although ICEs outnumber conjugative plasmids, the dynamics of ICE-bacterium coevolution, ICE transfer rates, and fitness costs are as yet largely unexplored. Conjugative plasmids and ICEs are both transferred by type IV secretion systems, but ICEs are typically immune to segregational loss, suggesting that the evolution of ICE-bacterium associations varies from that of plasmid-bacterium associations. Considering the high abundance of ICEs among bacteria, ICE-bacterium dynamics represent a promising challenge for future research that will enhance our understanding of AR spread in human pathogens.
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Affiliation(s)
- João Botelho
- Antibiotic Resistance Evolution Group, Max-Planck-Institute for Evolutionary Biology, Plön, Germany; Department of Evolutionary Ecology and Genetics, Zoological Institute, Christian-Albrechts University, Kiel, Germany.
| | - Hinrich Schulenburg
- Antibiotic Resistance Evolution Group, Max-Planck-Institute for Evolutionary Biology, Plön, Germany; Department of Evolutionary Ecology and Genetics, Zoological Institute, Christian-Albrechts University, Kiel, Germany
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Carr VR, Shkoporov A, Hill C, Mullany P, Moyes DL. Probing the Mobilome: Discoveries in the Dynamic Microbiome. Trends Microbiol 2020; 29:158-170. [PMID: 32448763 DOI: 10.1016/j.tim.2020.05.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 04/30/2020] [Accepted: 05/05/2020] [Indexed: 02/06/2023]
Abstract
There has been an explosion of metagenomic data representing human, animal, and environmental microbiomes. This provides an unprecedented opportunity for comparative and longitudinal studies of many functional aspects of the microbiome that go beyond taxonomic classification, such as profiling genetic determinants of antimicrobial resistance, interactions with the host, potentially clinically relevant functions, and the role of mobile genetic elements (MGEs). One of the most important but least studied of these aspects are the MGEs, collectively referred to as the 'mobilome'. Here we elaborate on the benefits and limitations of using different metagenomic protocols, discuss the relative merits of various sequencing technologies, and highlight relevant bioinformatics tools and pipelines to predict the presence of MGEs and their microbial hosts.
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Affiliation(s)
- Victoria R Carr
- Centre for Host-Microbiome Interactions, Faculty of Dentistry, Oral and Craniofacial Sciences, King's College London, London, UK; The Alan Turing Institute, British Library, London, UK.
| | - Andrey Shkoporov
- APC Microbiome Ireland, School of Microbiology, University College Cork, Cork, Ireland
| | - Colin Hill
- APC Microbiome Ireland, School of Microbiology, University College Cork, Cork, Ireland
| | - Peter Mullany
- Eastman Dental Institute, University College London, London, UK
| | - David L Moyes
- Centre for Host-Microbiome Interactions, Faculty of Dentistry, Oral and Craniofacial Sciences, King's College London, London, UK.
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Baumgartner M, Bayer F, Pfrunder-Cardozo KR, Buckling A, Hall AR. Resident microbial communities inhibit growth and antibiotic-resistance evolution of Escherichia coli in human gut microbiome samples. PLoS Biol 2020; 18:e3000465. [PMID: 32310938 PMCID: PMC7192512 DOI: 10.1371/journal.pbio.3000465] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 04/30/2020] [Accepted: 04/02/2020] [Indexed: 01/05/2023] Open
Abstract
Countering the rise of antibiotic-resistant pathogens requires improved understanding of how resistance emerges and spreads in individual species, which are often embedded in complex microbial communities such as the human gut microbiome. Interactions with other microorganisms in such communities might suppress growth and resistance evolution of individual species (e.g., via resource competition) but could also potentially accelerate resistance evolution via horizontal transfer of resistance genes. It remains unclear how these different effects balance out, partly because it is difficult to observe them directly. Here, we used a gut microcosm approach to quantify the effect of three human gut microbiome communities on growth and resistance evolution of a focal strain of Escherichia coli. We found the resident microbial communities not only suppressed growth and colonisation by focal E. coli but also prevented it from evolving antibiotic resistance upon exposure to a beta-lactam antibiotic. With samples from all three human donors, our focal E. coli strain only evolved antibiotic resistance in the absence of the resident microbial community, even though we found resistance genes, including a highly effective resistance plasmid, in resident microbial communities. We identified physical constraints on plasmid transfer that can explain why our focal strain failed to acquire some of these beneficial resistance genes, and we found some chromosomal resistance mutations were only beneficial in the absence of the resident microbiota. This suggests, depending on in situ gene transfer dynamics, interactions with resident microbiota can inhibit antibiotic-resistance evolution of individual species.
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Affiliation(s)
- Michael Baumgartner
- Institute of Integrative Biology, Department of Environmental Systems Science, ETH Zürich, Zürich, Switzerland
| | - Florian Bayer
- Biosciences, University of Exeter, Penryn, Cornwall, United Kingdom
| | - Katia R. Pfrunder-Cardozo
- Institute of Integrative Biology, Department of Environmental Systems Science, ETH Zürich, Zürich, Switzerland
| | - Angus Buckling
- Biosciences, University of Exeter, Penryn, Cornwall, United Kingdom
| | - Alex R. Hall
- Institute of Integrative Biology, Department of Environmental Systems Science, ETH Zürich, Zürich, Switzerland
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50
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Durrant MG, Li MM, Siranosian BA, Montgomery SB, Bhatt AS. A Bioinformatic Analysis of Integrative Mobile Genetic Elements Highlights Their Role in Bacterial Adaptation. Cell Host Microbe 2020; 27:140-153.e9. [PMID: 31862382 PMCID: PMC6952549 DOI: 10.1016/j.chom.2019.10.022] [Citation(s) in RCA: 98] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2019] [Revised: 06/18/2019] [Accepted: 10/29/2019] [Indexed: 11/26/2022]
Abstract
Mobile genetic elements (MGEs) contribute to bacterial adaptation and evolution; however, high-throughput, unbiased MGE detection remains challenging. We describe MGEfinder, a bioinformatic toolbox that identifies integrative MGEs and their insertion sites by using short-read sequencing data. MGEfinder identifies the genomic site of each MGE insertion and infers the identity of the inserted sequence. We apply MGEfinder to 12,374 sequenced isolates of 9 prevalent bacterial pathogens, including Mycobacterium tuberculosis, Staphylococcus aureus, and Escherichia coli, and identify thousands of MGEs, including candidate insertion sequences, conjugative transposons, and prophage elements. The MGE repertoire and insertion rates vary across species, and integration sites often cluster near genes related to antibiotic resistance, virulence, and pathogenicity. MGE insertions likely contribute to antibiotic resistance in laboratory experiments and clinical isolates. Additionally, we identified thousands of mobility genes, a subset of which have unknown function opening avenues for exploration. Future application of MGEfinder to commensal bacteria will further illuminate bacterial adaptation and evolution.
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Affiliation(s)
- Matthew G Durrant
- Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Michelle M Li
- Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | | | - Stephen B Montgomery
- Department of Genetics, Stanford University, Stanford, CA 94305, USA; Department of Pathology, Stanford University, Stanford, CA 94305, USA
| | - Ami S Bhatt
- Department of Genetics, Stanford University, Stanford, CA 94305, USA; Department of Medicine (Hematology, Blood and Marrow Transplantation) Stanford University, Stanford, CA 94305, USA.
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