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Piper KR, Ikhimiukor OO, Souza SSR, Garcia-Aroca T, Andam CP. Evolutionary dynamics of the accessory genomes of Staphylococcus aureus. mSphere 2024; 9:e0075123. [PMID: 38501935 PMCID: PMC11036810 DOI: 10.1128/msphere.00751-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 02/24/2024] [Indexed: 03/20/2024] Open
Abstract
Staphylococcus aureus is a ubiquitous commensal and opportunistic bacterial pathogen that can cause a wide gamut of infections, which are exacerbated by the presence of multidrug-resistant and methicillin-resistant S. aureus. S. aureus is genetically heterogeneous and consists of numerous distinct lineages. Using 558 complete genomes of S. aureus, we aim to determine how the accessory genome content among phylogenetic lineages of S. aureus is structured and has evolved. Bayesian hierarchical clustering identified 10 sequence clusters, of which seven contained major sequence types (ST 1, 5, 8, 30, 59, 239, and 398). The seven sequence clusters differed in their accessory gene content, including genes associated with antimicrobial resistance and virulence. Focusing on the two largest clusters, BAPS8 and BAPS10, and each consisting mostly of ST5 and ST8, respectively, we found that the structure and connected components in the co-occurrence networks of accessory genomes varied between them. These differences are explained, in part, by the variation in the rates at which the two sequence clusters gained and lost accessory genes, with the highest rate of gene accumulation occurring recently in their evolutionary histories. We also identified a divergent group within BAPS10 that has experienced high gene gain and loss early in its history. Together, our results show highly variable and dynamic accessory genomes in S. aureus that are structured by the history of the specific lineages that carry them.IMPORTANCEStaphylococcus aureus is an opportunistic, multi-host pathogen that can cause a variety of benign and life-threatening infections. Our results revealed considerable differences in the structure and evolution of the accessory genomes of major lineages within S. aureus. Such genomic variation within a species can have important implications on disease epidemiology, pathogenesis of infection, and interactions with the vertebrate host. Our findings provide important insights into the underlying genetic basis for the success of S. aureus as a highly adaptable and resistant pathogen, which will inform current efforts to control and treat staphylococcal diseases.
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Affiliation(s)
- Kathryn R. Piper
- Department of Biological Sciences, University at Albany, State University of New York, Albany, New York, USA
| | - Odion O. Ikhimiukor
- Department of Biological Sciences, University at Albany, State University of New York, Albany, New York, USA
| | - Stephanie S. R. Souza
- Department of Biological Sciences, University at Albany, State University of New York, Albany, New York, USA
| | - Teddy Garcia-Aroca
- Department of Biological Sciences, University at Albany, State University of New York, Albany, New York, USA
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - Cheryl P. Andam
- Department of Biological Sciences, University at Albany, State University of New York, Albany, New York, USA
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Selvaraj Anand S, Wu CT, Bremer J, Bhatti M, Treangen TJ, Kalia A, Shelburne SA, Shropshire WC. Identification of a novel CG307 sub-clade in third-generation-cephalosporin-resistant Klebsiella pneumoniae causing invasive infections in the USA. Microb Genom 2024; 10:001201. [PMID: 38407244 PMCID: PMC10926705 DOI: 10.1099/mgen.0.001201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 01/31/2024] [Indexed: 02/27/2024] Open
Abstract
Despite the notable clinical impact, recent molecular epidemiology regarding third-generation-cephalosporin-resistant (3GC-R) Klebsiella pneumoniae in the USA remains limited. We performed whole-genome sequencing of 3GC-R K. pneumoniae bacteraemia isolates collected from March 2016 to May 2022 at a tertiary care cancer centre in Houston, TX, USA, using Illumina and Oxford Nanopore Technologies platforms. A comprehensive comparative genomic analysis was performed to dissect population structure, transmission dynamics and pan-genomic signatures of our 3GC-R K. pneumoniae population. Of the 178 3GC-R K. pneumoniae bacteraemias that occurred during our study time frame, we were able to analyse 153 (86 %) bacteraemia isolates, 126 initial and 27 recurrent isolates. While isolates belonging to the widely prevalent clonal group (CG) 258 were rarely observed, the predominant CG, 307, accounted for 37 (29 %) index isolates and displayed a significant correlation (Pearson correlation test P value=0.03) with the annual frequency of 3GC-R K. pneumoniae bacteraemia. Interestingly, only 11 % (4/37) of CG307 isolates belonged to the commonly detected 'Texas-specific' clade that has been observed in previous Texas-based K. pneumoniae antimicrobial-resistance surveillance studies. We identified nearly half of our CG307 isolates (n=18) belonged to a novel, monophyletic CG307 sub-clade characterized by the chromosomally encoded bla SHV-205 and unique accessory genome content. This CG307 sub-clade was detected in various regions of the USA, with genome sequences from 24 additional strains becoming recently available in the National Center for Biotechnology Information (NCBI) SRA database. Collectively, this study underscores the emergence and dissemination of a distinct CG307 sub-clade that is a prevalent cause of 3GC-R K. pneumoniae bacteraemia among cancer patients seen in Houston, TX, and has recently been isolated throughout the USA.
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Affiliation(s)
- Selvalakshmi Selvaraj Anand
- Graduate Program in Diagnostic Genetics and Genomics, School of Health Professions, MD Anderson Cancer Center, University of Texas, Houston, TX, USA
| | - Chin-Ting Wu
- Graduate Program in Diagnostic Genetics and Genomics, School of Health Professions, MD Anderson Cancer Center, University of Texas, Houston, TX, USA
| | - Jordan Bremer
- Department of Infectious Diseases, Infection Control, and Employee Health, MD Anderson Cancer Center, University of Texas, Houston, TX, USA
| | - Micah Bhatti
- Department of Laboratory Medicine, MD Anderson Cancer Center, University of Texas, Houston, TX, USA
| | - Todd J. Treangen
- Department of Computer Science, Rice University, Houston, TX, USA
| | - Awdhesh Kalia
- Graduate Program in Diagnostic Genetics and Genomics, School of Health Professions, MD Anderson Cancer Center, University of Texas, Houston, TX, USA
| | - Samuel A. Shelburne
- Department of Infectious Diseases, Infection Control, and Employee Health, MD Anderson Cancer Center, University of Texas, Houston, TX, USA
- Department of Genomic Medicine, MD Anderson Cancer Center, University of Texas, Houston, TX, USA
| | - William C. Shropshire
- Department of Infectious Diseases, Infection Control, and Employee Health, MD Anderson Cancer Center, University of Texas, Houston, TX, USA
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Puente-Sánchez F, Hoetzinger M, Buck M, Bertilsson S. Exploring environmental intra-species diversity through non-redundant pangenome assemblies. Mol Ecol Resour 2023; 23:1724-1736. [PMID: 37382302 DOI: 10.1111/1755-0998.13826] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 05/24/2023] [Accepted: 06/15/2023] [Indexed: 06/30/2023]
Abstract
At the genome level, microorganisms are highly adaptable both in terms of allele and gene composition. Such heritable traits emerge in response to different environmental niches and can have a profound influence on microbial community dynamics. As a consequence, any individual genome or population will contain merely a fraction of the total genetic diversity of any operationally defined "species", whose ecological potential can thus be only fully understood by studying all of their genomes and the genes therein. This concept, known as the pangenome, is valuable for studying microbial ecology and evolution, as it partitions genomes into core (present in all the genomes from a species, and responsible for housekeeping and species-level niche adaptation among others) and accessory regions (present only in some, and responsible for intra-species differentiation). Here we present SuperPang, an algorithm producing pangenome assemblies from a set of input genomes of varying quality, including metagenome-assembled genomes (MAGs). SuperPang runs in linear time and its results are complete, non-redundant, preserve gene ordering and contain both coding and non-coding regions. Our approach provides a modular view of the pangenome, identifying operons and genomic islands, and allowing to track their prevalence in different populations. We illustrate this by analysing intra-species diversity in Polynucleobacter, a bacterial genus ubiquitous in freshwater ecosystems, characterized by their streamlined genomes and their ecological versatility. We show how SuperPang facilitates the simultaneous analysis of allelic and gene content variation under different environmental pressures, allowing us to study the drivers of microbial diversification at unprecedented resolution.
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Affiliation(s)
- Fernando Puente-Sánchez
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Matthias Hoetzinger
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Moritz Buck
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Stefan Bertilsson
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden
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Milner DS, Galindo LJ, Irwin NAT, Richards TA. Transporter Proteins as Ecological Assets and Features of Microbial Eukaryotic Pangenomes. Annu Rev Microbiol 2023; 77:45-66. [PMID: 36944262 DOI: 10.1146/annurev-micro-032421-115538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2023]
Abstract
Here we review two connected themes in evolutionary microbiology: (a) the nature of gene repertoire variation within species groups (pangenomes) and (b) the concept of metabolite transporters as accessory proteins capable of providing niche-defining "bolt-on" phenotypes. We discuss the need for improved sampling and understanding of pangenome variation in eukaryotic microbes. We then review the factors that shape the repertoire of accessory genes within pangenomes. As part of this discussion, we outline how gene duplication is a key factor in both eukaryotic pangenome variation and transporter gene family evolution. We go on to outline how, through functional characterization of transporter-encoding genes, in combination with analyses of how transporter genes are gained and lost from accessory genomes, we can reveal much about the niche range, the ecology, and the evolution of virulence of microbes. We advocate for the coordinated systematic study of eukaryotic pangenomes through genome sequencing and the functional analysis of genes found within the accessory gene repertoire.
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Affiliation(s)
- David S Milner
- Department of Biology, University of Oxford, Oxford, United Kingdom;
| | | | - Nicholas A T Irwin
- Department of Biology, University of Oxford, Oxford, United Kingdom;
- Merton College, University of Oxford, Oxford, United Kingdom
| | - Thomas A Richards
- Department of Biology, University of Oxford, Oxford, United Kingdom;
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Wiehlmann L, Klockgether J, Hammerbacher AS, Salunkhe P, Horatzek S, Munder A, Peilert JF, Gulbins E, Eberl L, Tümmler B. A VirB4 ATPase of the mobile accessory genome orchestrates core genome-encoded features of physiology, metabolism, and virulence of Pseudomonas aeruginosa TBCF10839. Front Cell Infect Microbiol 2023; 13:1234420. [PMID: 37577372 PMCID: PMC10413270 DOI: 10.3389/fcimb.2023.1234420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Accepted: 07/10/2023] [Indexed: 08/15/2023] Open
Abstract
Pseudomonas aeruginosa TBCF10839 is a highly virulent strain that can persist and replicate in human neutrophils. Screening of a signature-tagged mutagenesis (STM) TBCF10839 transposon library in phagocytosis tests identified a mutant that carried the transposon in the VirB4 homolog 5PG21 of an integrative and conjugative element (ICE)-associated type IV secretion system of the pKLC102 subtype. 5P21 TBCF10839 insertion mutants were deficient in metabolic versatility, secretion, quorum sensing, and virulence. The mutants were efficiently killed in phagocytosis tests in vitro and were avirulent in an acute murine airway infection model in vivo. The inactivation of 5PG21 silenced the rhl, las, and pqs operons and the gene expression for the synthesis of hydrogen cyanide, the antimetabolite l-2-amino-4-methoxy-trans-3-butenoic acid, and the H2- and H3-type VI secretion systems and their associated effectors. The mutants were impaired in the utilization of carbon sources and stored compounds that are not funneled into intermediary metabolism. This showcase demonstrates that a single gene of the mobile accessory genome can become an essential element to operate the core genome-encoded features of metabolism and virulence.
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Affiliation(s)
- Lutz Wiehlmann
- Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
- Research Core Unit Genomics, Hannover Medical School, Hannover, Germany
| | - Jens Klockgether
- Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
| | - Anna-Silke Hammerbacher
- Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
| | - Prabhakar Salunkhe
- Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
| | - Sonja Horatzek
- Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
| | - Antje Munder
- Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease, German Center for Lung Research, Hannover, Germany
| | | | - Erich Gulbins
- Department of Surgery, University of Cincinnati College of Medicine, Cincinnati, OH, United States
- Institute of Molecular Biology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Leo Eberl
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Burkhard Tümmler
- Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease, German Center for Lung Research, Hannover, Germany
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Rodrigues C, Lanza VF, Peixe L, Coque TM, Novais Â. Phylogenomics of Globally Spread Clonal Groups 14 and 15 of Klebsiella pneumoniae. Microbiol Spectr 2023; 11:e0339522. [PMID: 37098951 PMCID: PMC10269502 DOI: 10.1128/spectrum.03395-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Accepted: 03/26/2023] [Indexed: 04/27/2023] Open
Abstract
Klebsiella pneumoniae sequence type 14 (ST14) and ST15 caused outbreaks of CTX-M-15 and/or carbapenemase producers worldwide, but their phylogeny and global dynamics remain unclear. We clarified the evolution of K. pneumoniae clonal group 14 (CG14) and CG15 by analyzing the capsular locus (KL), resistome, virulome, and plasmidome of public genomes (n = 481) and de novo sequences (n = 9) representing main sublineages circulating in Portugal. CG14 and CG15 evolved independently within 6 main subclades defined according to the KL and the accessory genome. The CG14 (n = 65) clade was structured in two large monophyletic subclades, CG14-I (KL2, 86%) and CG14-II (KL16, 14%), whose emergences were dated to 1932 and 1911, respectively. Genes encoding extended-spectrum β-lactamase (ESBL), AmpC, and/or carbapenemases were mostly observed in CG14-I (71% versus 22%). CG15 clade (n = 170) was segregated into subclades CG15-IA (KL19/KL106, 9%), CG15-IB (variable KL types, 6%), CG15-IIA (KL24, 43%) and CG15-IIB (KL112, 37%). Most CG15 genomes carried specific GyrA and ParC mutations and emerged from a common ancestor in 1989. CTX-M-15 was especially prevalent in CG15 (68% CG15 versus 38% CG14) and in CG15-IIB (92%). Plasmidome analysis revealed 27 predominant plasmid groups (PG), including particularly pervasive and recombinant F-type (n = 10), Col (n = 10), and new plasmid types. While blaCTX-M-15 was acquired multiple times by a high diversity of F-type mosaic plasmids, other antibiotic resistance genes (ARGs) were dispersed by IncL (blaOXA-48) or IncC (blaCMY/TEM-24) plasmids. We first demonstrate an independent evolutionary trajectory for CG15 and CG14 and how the acquisition of specific KL, quinolone-resistance determining region (QRDR) mutations (CG15), and ARGs in highly recombinant plasmids could have shaped the expansion and diversification of particular subclades (CG14-I and CG15-IIA/IIB). IMPORTANCE Klebsiella pneumoniae represents a major threat in the burden of antibiotic resistance (ABR). Available studies to explain the origin, the diversity, and the evolution of certain ABR K. pneumoniae populations have mainly been focused on a few clonal groups (CGs) using phylogenetic analysis of the core genome, the accessory genome being overlooked. Here, we provide unique insights into the phylogenetic evolution of CG14 and CG15, two poorly characterized CGs which have contributed to the global dissemination of genes responsible for resistance to first-line antibiotics such as β-lactams. Our results point out an independent evolution of these two CGs and highlight the existence of different subclades structured by the capsular type and the accessory genome. Moreover, the contribution of a turbulent flux of plasmids (especially multireplicon F type and Col) and adaptive traits (antibiotic resistance and metal tolerance genes) to the pangenome reflect the exposure and adaptation of K. pneumoniae under different selective pressures.
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Affiliation(s)
- Carla Rodrigues
- UCIBIO, Applied Molecular Biosciences Unit, Department of Biological Sciences, Laboratory of Microbiology, Faculty of Pharmacy, University of Porto, Porto, Portugal
| | - Val F. Lanza
- Unidad de Genómica Traslacional Hospital Universitario Ramón y Cajal (IRYCIS), Madrid, Spain
- CIBER en Enfermedades Infecciosas (CIBERINFEC), Madrid, Spain
| | - Luísa Peixe
- UCIBIO, Applied Molecular Biosciences Unit, Department of Biological Sciences, Laboratory of Microbiology, Faculty of Pharmacy, University of Porto, Porto, Portugal
- Associate Laboratory i4HB—Institute for Health and Bioeconomy, Faculty of Pharmacy, University of Porto, Porto, Portugal
| | - Teresa M. Coque
- CIBER en Enfermedades Infecciosas (CIBERINFEC), Madrid, Spain
- Servicio de Microbiología, Hospital Universitario Ramón y Cajal (IRYCIS), Madrid, Spain
| | - Ângela Novais
- UCIBIO, Applied Molecular Biosciences Unit, Department of Biological Sciences, Laboratory of Microbiology, Faculty of Pharmacy, University of Porto, Porto, Portugal
- Associate Laboratory i4HB—Institute for Health and Bioeconomy, Faculty of Pharmacy, University of Porto, Porto, Portugal
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Svahn AJ, Suster CJE, Chang SL, Rockett RJ, Sim EM, Cliff OM, Wang Q, Arnott A, Ramsperger M, Sorrell TC, Sintchenko V, Prokopenko M. Pangenome Analysis of a Salmonella Enteritidis Population Links a Major Outbreak to a Gifsy-1-Like Prophage Containing Anti-Inflammatory Gene gogB. Microbiol Spectr 2023; 11:e0279122. [PMID: 36916949 PMCID: PMC10100743 DOI: 10.1128/spectrum.02791-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 02/26/2023] [Indexed: 03/15/2023] Open
Abstract
A major outbreak of the globally significant Salmonella Enteritidis foodborne pathogen was identified within a large clinical data set by a program of routine WGS of clinical presentations of salmonellosis in New South Wales, Australia. Pangenome analysis helped to quantify and isolate prophage content within the accessory partition of the pangenome. A prophage similar to Gifsy-1 (henceforth GF-1L) was found to occur in all isolates of the outbreak core SNP cluster, and in three other isolates. Further analysis revealed that the GF-1L prophage carried the gogB virulence factor. These observations suggest that GF-1L may be an important marker of virulence for S. Enteritidis population screening and, that anti-inflammatory, gogB-mediated virulence currently associated with Salmonella Typhimurium may also be displayed by S. Enteritidis. IMPORTANCE We examined 5 years of genomic and epidemiological data for the significant global foodborne pathogen, Salmonella enterica. Although Salmonella enterica subspecies enterica serovar Enteritidis (S. Enteritidis) is the leading cause of salmonellosis in the USA and Europe, prior to 2018 it was not endemic in the southern states of Australia. However, in 2018 a large outbreak led to the endemicity of S. Enteritidis in New South Wales, Australia, and a unique opportunity to study this phenomenon. Using pangenome analysis we uncovered that this clone contained a Gifsy-1-like prophage harboring the known virulence factor gogB. The prophage reported has not previously been described in S. Enteritidis isolates.
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Affiliation(s)
- Adam J. Svahn
- Centre for Complex Systems, Faculty of Engineering, The University of Sydney, Sydney, NSW, Australia
- Sydney Infectious Diseases Institute, The University of Sydney, Westmead, NSW, Australia
| | - Carl J. E. Suster
- Sydney Infectious Diseases Institute, The University of Sydney, Westmead, NSW, Australia
- Centre for Infectious Diseases and Microbiology–Public Health, Westmead Hospital, Westmead, New South Wales, Australia
| | - Sheryl L. Chang
- Centre for Complex Systems, Faculty of Engineering, The University of Sydney, Sydney, NSW, Australia
| | - Rebecca J. Rockett
- Sydney Infectious Diseases Institute, The University of Sydney, Westmead, NSW, Australia
- Centre for Infectious Diseases and Microbiology–Public Health, Westmead Hospital, Westmead, New South Wales, Australia
| | - Eby M. Sim
- Sydney Infectious Diseases Institute, The University of Sydney, Westmead, NSW, Australia
- Centre for Infectious Diseases and Microbiology–Public Health, Westmead Hospital, Westmead, New South Wales, Australia
| | - Oliver M. Cliff
- Centre for Complex Systems, Faculty of Engineering, The University of Sydney, Sydney, NSW, Australia
- School of Physics, Faculty of Science, The University of Sydney, Sydney, NSW, Australia
| | - Qinning Wang
- Centre for Infectious Diseases and Microbiology–Public Health, Westmead Hospital, Westmead, New South Wales, Australia
- Institute of Clinical Pathology and Medical Research, NSW Health Pathology, Westmead, NSW, Australia
| | - Alicia Arnott
- Sydney Infectious Diseases Institute, The University of Sydney, Westmead, NSW, Australia
- Centre for Infectious Diseases and Microbiology–Public Health, Westmead Hospital, Westmead, New South Wales, Australia
- Institute of Clinical Pathology and Medical Research, NSW Health Pathology, Westmead, NSW, Australia
| | - Marc Ramsperger
- Institute of Clinical Pathology and Medical Research, NSW Health Pathology, Westmead, NSW, Australia
| | - Tania C. Sorrell
- Sydney Infectious Diseases Institute, The University of Sydney, Westmead, NSW, Australia
- Centre for Infectious Diseases and Microbiology–Public Health, Westmead Hospital, Westmead, New South Wales, Australia
| | - Vitali Sintchenko
- Sydney Infectious Diseases Institute, The University of Sydney, Westmead, NSW, Australia
- Centre for Infectious Diseases and Microbiology–Public Health, Westmead Hospital, Westmead, New South Wales, Australia
- Institute of Clinical Pathology and Medical Research, NSW Health Pathology, Westmead, NSW, Australia
| | - Mikhail Prokopenko
- Centre for Complex Systems, Faculty of Engineering, The University of Sydney, Sydney, NSW, Australia
- Sydney Infectious Diseases Institute, The University of Sydney, Westmead, NSW, Australia
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Cerbino GN, Traglia GM, Ayala Nuñez T, Parmeciano Di Noto G, Ramírez MS, Centrón D, Iriarte A, Quiroga C. Comparative genome analysis of the genus Shewanella unravels the association of key genetic traits with known and potential pathogenic lineages. Front Microbiol 2023; 14:1124225. [PMID: 36925471 PMCID: PMC10011109 DOI: 10.3389/fmicb.2023.1124225] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 02/06/2023] [Indexed: 03/06/2023] Open
Abstract
Shewanella spp. are Gram-negative rods widely disseminated in aquatic niches that can also be found in human-associated environments. In recent years, reports of infections caused by these bacteria have increased significantly. Mobilome and resistome analysis of a few species showed that they are versatile; however, comprehensive comparative studies in the genus are lacking. Here, we analyzed the genetic traits of 144 genomes from Shewanella spp. isolates focusing on the mobilome, resistome, and virulome to establish their evolutionary relationship and detect unique features based on their genome content and habitat. Shewanella spp. showed a great diversity of mobile genetic elements (MGEs), most of them associated with monophyletic lineages of clinical isolates. Furthermore, 79/144 genomes encoded at least one antimicrobial resistant gene with their highest occurrence in clinical-related lineages. CRISPR-Cas systems, which confer immunity against MGEs, were found in 41 genomes being I-E and I-F the more frequent ones. Virulome analysis showed that all Shewanella spp. encoded different virulence genes (motility, quorum sensing, biofilm, adherence, etc.) that may confer adaptive advantages for survival against hosts. Our data revealed that key accessory genes are frequently found in two major clinical-related groups, which encompass the opportunistic pathogens Shewanella algae and Shewanella xiamenensis together with several other species. This work highlights the evolutionary nature of Shewanella spp. genomes, capable of acquiring different key genetic traits that contribute to their adaptation to different niches and facilitate the emergence of more resistant and virulent isolates that impact directly on human and animal health.
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Affiliation(s)
- Gabriela N Cerbino
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Tecnológicas, Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPAM), Facultad de Medicina, Buenos Aires, Argentina
| | - German M Traglia
- Laboratorio de Biología Computacional, Departamento de Desarrollo Biotecnológico, Instituto de Higiene, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Teolincacihuatl Ayala Nuñez
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Tecnológicas, Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPAM), Facultad de Medicina, Buenos Aires, Argentina
| | - Gisela Parmeciano Di Noto
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Tecnológicas, Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPAM), Facultad de Medicina, Buenos Aires, Argentina
| | - María Soledad Ramírez
- Center for Applied Biotechnology Studies, Department of Biological Science, California State University, Fullerton, Fullerton, CA, United States
| | - Daniela Centrón
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Tecnológicas, Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPAM), Facultad de Medicina, Buenos Aires, Argentina
| | - Andrés Iriarte
- Laboratorio de Biología Computacional, Departamento de Desarrollo Biotecnológico, Instituto de Higiene, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Cecilia Quiroga
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Tecnológicas, Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPAM), Facultad de Medicina, Buenos Aires, Argentina
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Fonseca EL, Morgado SM, Caldart RV, Vicente AC. Global Genomic Epidemiology of Escherichia coli (ExPEC) ST38 Lineage Revealed a Virulome Associated with Human Infections. Microorganisms 2022; 10:microorganisms10122482. [PMID: 36557735 PMCID: PMC9787326 DOI: 10.3390/microorganisms10122482] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 12/05/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Most of the extraintestinal human infections worldwide are caused by specific extraintestinal pathogenic Escherichia coli (ExPEC) lineages, which also present a zoonotic character. One of these lineages belongs to ST38, a high-risk globally disseminated ExPEC. To get insights on the aspects of the global ST38 epidemiology and evolution as a multidrug-resistant and pathogenic lineage concerning the three axes of the One Health concept (humans, animals, and natural environments), this study performed a global phylogenomic analysis on ST38 genomes. METHODS A phylogenetic reconstruction based on 376 ST38 genomes recovered from environments, humans, livestock, and wild and domestic animals in all continents throughout three decades was performed. The global information concerning the ST38 resistome and virulome was also approached by in silico analyses. RESULTS In general, the phylogenomic analyses corroborated the zoonotic character of the ExPEC ST38, since clonal strains were recovered from both animal and human sources distributed worldwide. Moreover, our findings revealed that, independent of host sources and geographic origin, the genomes were distributed in two major clades (Clades 1 and 2). However, the ST38 accessory genome was not strictly associated with clades and sub-clades, as found for the type 2 T3SS ETT2 that was evenly distributed throughout Clades 1 and 2. Of note was the presence of the Yersinia pestis-like high-pathogenicity island (HPI) exclusively in the major Clade 2, in which prevails most of the genomes from human origin recovered worldwide (2000 to 2020). CONCLUSIONS This evidence corroborates the HPI association with successful E. coli ST38 establishment in human infections.
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Affiliation(s)
- Erica L. Fonseca
- Laboratório de Genética Molecular de Microrganismos, Instituto Oswaldo Cruz—FIOCRUZ, Rio de Janeiro 21040-360, RJ, Brazil
- Correspondence: ; Tel.: +55-21-3865-8176
| | - Sergio M. Morgado
- Laboratório de Genética Molecular de Microrganismos, Instituto Oswaldo Cruz—FIOCRUZ, Rio de Janeiro 21040-360, RJ, Brazil
| | - Raquel V. Caldart
- Centro de Ciências da Saúde, Universidade Federal de Roraima, Boa Vista 69300-000, RR, Brazil
| | - Ana Carolina Vicente
- Laboratório de Genética Molecular de Microrganismos, Instituto Oswaldo Cruz—FIOCRUZ, Rio de Janeiro 21040-360, RJ, Brazil
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10
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Worden PJ, Bogema DR, Micallef ML, Go J, Deutscher AT, Labbate M, Green TJ, King WL, Liu M, Seymour JR, Jenkins C. Phylogenomic diversity of Vibrio species and other Gammaproteobacteria isolated from Pacific oysters ( Crassostrea gigas) during a summer mortality outbreak. Microb Genom 2022; 8:mgen000883. [PMID: 36748707 PMCID: PMC9837568 DOI: 10.1099/mgen.0.000883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The Pacific oyster (PO), Crassostrea gigas, is an important commercial marine species but periodically experiences large stock losses due to disease events known as summer mortality. Summer mortality has been linked to environmental perturbations and numerous viral and bacterial agents, indicating this disease is multifactorial in nature. In 2013 and 2014, several summer mortality events occurred within the Port Stephens estuary (NSW, Australia). Extensive culture and molecular-based investigations were undertaken and several potentially pathogenic Vibrio species were identified. To improve species identification and genomically characterise isolates obtained from this outbreak, whole-genome sequencing (WGS) and subsequent genomic analyses were performed on 48 bacterial isolates, as well as a further nine isolates from other summer mortality studies using the same batch of juveniles. Average nucleotide identity (ANI) identified most isolates to the species level and included members of the Photobacterium, Pseudoalteromonas, Shewanella and Vibrio genera, with Vibrio species making up more than two-thirds of all species identified. Construction of a phylogenomic tree, ANI analysis, and pan-genome analysis of the 57 isolates represents the most comprehensive culture-based phylogenomic survey of Vibrios during a PO summer mortality event in Australian waters and revealed large genomic diversity in many of the identified species. Our analysis revealed limited and inconsistent associations between isolate species and their geographical origins, or host health status. Together with ANI and pan-genome results, these inconsistencies suggest that to determine the role that microbes may have in Pacific oyster summer mortality events, isolate identification must be at the taxonomic level of strain. Our WGS data (specifically, the accessory genomes) differentiated bacterial strains, and coupled with associated metadata, highlight the possibility of predicting a strain's environmental niche and level of pathogenicity.
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Affiliation(s)
- Paul J. Worden
- NSW Department of Primary Industries, Elizabeth Macarthur Agricultural Institute, Woodbridge Rd, Menangle, NSW 2568
| | - Daniel R. Bogema
- NSW Department of Primary Industries, Elizabeth Macarthur Agricultural Institute, Woodbridge Rd, Menangle, NSW 2568
| | - Melinda L. Micallef
- NSW Department of Primary Industries, Elizabeth Macarthur Agricultural Institute, Woodbridge Rd, Menangle, NSW 2568
| | - Jeffrey Go
- NSW Department of Primary Industries, Elizabeth Macarthur Agricultural Institute, Woodbridge Rd, Menangle, NSW 2568
| | - Ania T. Deutscher
- NSW Department of Primary Industries, Elizabeth Macarthur Agricultural Institute, Woodbridge Rd, Menangle, NSW 2568
| | - Maurizio Labbate
- School of Life Sciences, Faculty of Science, University of Technology Sydney, Sydney, NSW, Australia
| | - Timothy J. Green
- Centre for Shellfish Research, Vancouver Island University, Nanaimo, British Columbia,, Canada
| | - William L. King
- Department of Plant Pathology and Environmental MIcrobiology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Michael Liu
- iThree Institute, University of Technology Sydney, Building 4, 745 Harris Street, Broadway, Ultimo, NSW, 2007
| | - Justin R. Seymour
- Climate Change Cluster, University of Technology Sydney, Ultimo, NSW, 2007
| | - Cheryl Jenkins
- NSW Department of Primary Industries, Elizabeth Macarthur Agricultural Institute, Woodbridge Rd, Menangle, NSW 2568,*Correspondence: Cheryl Jenkins,
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11
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Achtman M, Zhou Z, Charlesworth J, Baxter L. EnteroBase: hierarchical clustering of 100 000s of bacterial genomes into species/subspecies and populations. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210240. [PMID: 35989609 PMCID: PMC9393565 DOI: 10.1098/rstb.2021.0240] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Accepted: 03/07/2022] [Indexed: 12/14/2022] Open
Abstract
The definition of bacterial species is traditionally a taxonomic issue while bacterial populations are identified by population genetics. These assignments are species specific, and depend on the practitioner. Legacy multilocus sequence typing is commonly used to identify sequence types (STs) and clusters (ST Complexes). However, these approaches are not adequate for the millions of genomic sequences from bacterial pathogens that have been generated since 2012. EnteroBase (http://enterobase.warwick.ac.uk) automatically clusters core genome MLST allelic profiles into hierarchical clusters (HierCC) after assembling annotated draft genomes from short-read sequences. HierCC clusters span core sequence diversity from the species level down to individual transmission chains. Here we evaluate HierCC's ability to correctly assign 100 000s of genomes to the species/subspecies and population levels for Salmonella, Escherichia, Clostridoides, Yersinia, Vibrio and Streptococcus. HierCC assignments were more consistent with maximum-likelihood super-trees of core SNPs or presence/absence of accessory genes than classical taxonomic assignments or 95% ANI. However, neither HierCC nor ANI were uniformly consistent with classical taxonomy of Streptococcus. HierCC was also consistent with legacy eBGs/ST Complexes in Salmonella or Escherichia and with O serogroups in Salmonella. Thus, EnteroBase HierCC supports the automated identification of and assignment to species/subspecies and populations for multiple genera. This article is part of a discussion meeting issue 'Genomic population structures of microbial pathogens'.
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12
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de Korne-Elenbaas J, Bruisten SM, van Dam AP, Maiden MCJ, Harrison OB. The Neisseria gonorrhoeae Accessory Genome and Its Association with the Core Genome and Antimicrobial Resistance. Microbiol Spectr 2022; 10:e0265421. [PMID: 35604129 PMCID: PMC9241924 DOI: 10.1128/spectrum.02654-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 04/14/2022] [Indexed: 01/22/2023] Open
Abstract
The bacterial accessory genome provides the genetic flexibility needed to facilitate environment and host adaptation. In Neisseria gonorrhoeae, known accessory elements include plasmids which can transfer and mediate antimicrobial resistance (AMR); however, chromosomal accessory genes could also play a role in AMR. Here, the gonococcal accessory genome was characterized using gene-by-gene approaches and its association with the core genome and AMR were assessed. The gonococcal accessory gene pool consisted of 247 genes, which were mainly genes located on large mobile genetic elements, phage associated genes, or genes encoding putative secretion systems. Accessory elements showed similar synteny across genomes, indicating either a predisposition for particular genomic locations or ancestral inheritance that are conserved during strain expansion. Significant associations were found between the prevalence of accessory elements and core genome multi-locus sequence types (cgMLST), consistent with a structured gonococcal population despite frequent horizontal gene transfer (HGT). Increased prevalence of putative DNA exchange regulators was significantly associated with AMR, which included a putative secretion system, methyltransferases and a toxin-antitoxin system. Although frequent HGT results in high genetic diversity in the gonococcus, we found that this is mediated by a small gene pool. In fact, a highly organized genome composition was identified with a strong association between the accessory and core genome. Increased prevalence of DNA exchange regulators in antimicrobial resistant isolates suggests that genetic material exchange plays a role in the development or maintenance of AMR. These findings enhance our understanding of gonococcal genome architecture and have important implications for gonococcal population biology. IMPORTANCE The emergence of antimicrobial resistance (AMR) against third generation cephalosporins in Neisseria gonorrhoeae is a major public health concern, as these are antibiotics of last resort for the effective treatment of gonorrhea. Although the resistance mechanisms against this class of antibiotics have not been entirely resolved, resistance against other classes of antibiotics, such as tetracyclines, is known to be mediated through plasmids, which are known gonococcal extra-chromosomal accessory elements. A complete assessment of the chromosomal accessory genome content and its role in AMR has not yet been undertaken. Here, we comprehensively characterize the gonococcal accessory genome to better understand genome architecture as well as the evolution and mechanisms of AMR in this species.
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Affiliation(s)
- Jolinda de Korne-Elenbaas
- Public Health Laboratory, Department of Infectious Diseases, Public Health Service of Amsterdam, Amsterdam, the Netherlands
- Amsterdam UMC, University of Amsterdam, Department of Medical Microbiology, Amsterdam Institute for Infection and Immunity (AI&II), Academic Medical Center, Amsterdam, the Netherlands
| | - Sylvia M. Bruisten
- Public Health Laboratory, Department of Infectious Diseases, Public Health Service of Amsterdam, Amsterdam, the Netherlands
- Amsterdam UMC, University of Amsterdam, Amsterdam Institute for Infection and Immunity (AI&II), Amsterdam, the Netherlands
| | - Alje P. van Dam
- Public Health Laboratory, Department of Infectious Diseases, Public Health Service of Amsterdam, Amsterdam, the Netherlands
- Amsterdam UMC, University of Amsterdam, Department of Medical Microbiology, Amsterdam Institute for Infection and Immunity (AI&II), Academic Medical Center, Amsterdam, the Netherlands
| | - Martin C. J. Maiden
- Department of Zoology, Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Odile B. Harrison
- Department of Zoology, Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
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13
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Picazo DR, Werner A, Dagan T, Kupczok A. Pangenome evolution in environmentally transmitted symbionts of deep-sea mussels is governed by vertical inheritance. Genome Biol Evol 2022; 14:6613374. [PMID: 35731940 PMCID: PMC9260185 DOI: 10.1093/gbe/evac098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/18/2022] [Indexed: 11/13/2022] Open
Abstract
Microbial pangenomes vary across species; their size and structure are determined by genetic diversity within the population and by gene loss and horizontal gene transfer (HGT). Many bacteria are associated with eukaryotic hosts where the host colonization dynamics may impact bacterial genome evolution. Host-associated lifestyle has been recognized as a barrier to HGT in parentally transmitted bacteria. However, pangenome evolution of environmentally acquired symbionts remains understudied, often due to limitations in symbiont cultivation. Using high-resolution metagenomics, here we study pangenome evolution of two co-occurring endosymbionts inhabiting Bathymodiolus brooksi mussels from a single cold seep. The symbionts, sulfur-oxidizing (SOX) and methane-oxidizing (MOX) gamma-proteobacteria, are environmentally acquired at an early developmental stage and individual mussels may harbor multiple strains of each symbiont species. We found differences in the accessory gene content of both symbionts across individual mussels, which are reflected by differences in symbiont strain composition. Compared to core genes, accessory genes are enriched in genome plasticity functions. We found no evidence for recent horizontal gene transfer between both symbionts. A comparison between the symbiont pangenomes revealed that the MOX population is less diverged and contains fewer accessory genes, supporting that the MOX association with B. brooksi is more recent in comparison to that of SOX. Our results show that the pangenomes of both symbionts evolved mainly by vertical inheritance. We conclude that genome evolution of environmentally transmitted symbionts that associate with individual hosts over their lifetime is affected by a narrow symbiosis where the frequency of HGT is constrained..
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Affiliation(s)
- Devani Romero Picazo
- Genomic Microbiology Group, Institute of General Microbiology, Christian-Albrechts University, Kiel, Germany
| | - Almut Werner
- Genomic Microbiology Group, Institute of General Microbiology, Christian-Albrechts University, Kiel, Germany
| | - Tal Dagan
- Genomic Microbiology Group, Institute of General Microbiology, Christian-Albrechts University, Kiel, Germany
| | - Anne Kupczok
- Genomic Microbiology Group, Institute of General Microbiology, Christian-Albrechts University, Kiel, Germany.,Max Planck Institute for Marine Microbiology, Bremen, Germany.,Bioinformatics Group, Wageningen University & Research, Wageningen, The Netherlands
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14
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Mouftah SF, Pascoe B, Calland JK, Mourkas E, Tonkin N, Lefevre C, Deuker D, Smith S, Wickenden H, Hitchings MD, Sheppard SK, Elhadidy M. Local accessory gene sharing among Egyptian Campylobacter potentially promotes the spread of antimicrobial resistance. Microb Genom 2022; 8. [PMID: 35675117 PMCID: PMC9455717 DOI: 10.1099/mgen.0.000834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Campylobacter is the most common cause of bacterial gastroenteritis worldwide, and diarrhoeal disease is a major cause of child morbidity, growth faltering and mortality in low- and middle-income countries. Despite evidence of high incidence and differences in disease epidemiology, there is limited genomic data from studies in developing countries. In this study, we aimed to quantify the extent of gene sharing in local and global populations. We characterized the genetic diversity and accessory-genome content of a collection of Campylobacter isolates from the Cairo metropolitan area, Egypt. In total, 112 Campylobacter isolates were collected from broiler carcasses (n=31), milk and dairy products (n=24), and patients suffering from gastroenteritis (n=57). Among the most common sequence types (STs), we identified the globally disseminated host generalist ST-21 clonal complex (CC21) and the poultry specialists CC206, CC464 and CC48. Notably, CC45 and the cattle-specialist CC42 were under-represented, with a total absence of CC61. Core- and accessory-genome sharing was compared among isolates from Egypt and a comparable collection from the UK (Oxford). Lineage-specific accessory-genome sharing was significantly higher among isolates from the same country, particularly CC21, which demonstrated greater local geographical clustering. In contrast, no geographical clustering was noted in either the core or accessory genome of CC828, suggesting a highly admixed population. A greater proportion of Campylobacter coli isolates were multidrug resistant compared to Campylobacter jejuni. Our results suggest that there is more horizontal transfer of accessory genes between strains in Egypt. This has strong implications for controlling the spread of antimicrobial resistance among this important pathogen.
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Affiliation(s)
- Shaimaa F Mouftah
- Biomedical Sciences Program, University of Science and Technology, Zewail City of Science and Technology, Giza, Egypt
| | - Ben Pascoe
- Milner Centre of Evolution, University of Bath, Claverton Down, Bath, UK.,Chiang Mai University, Chiang Mai, Thailand
| | - Jessica K Calland
- Milner Centre of Evolution, University of Bath, Claverton Down, Bath, UK
| | - Evangelos Mourkas
- Milner Centre of Evolution, University of Bath, Claverton Down, Bath, UK
| | - Naomi Tonkin
- Milner Centre of Evolution, University of Bath, Claverton Down, Bath, UK
| | - Charlotte Lefevre
- Milner Centre of Evolution, University of Bath, Claverton Down, Bath, UK.,Present address: Division of Virology, Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, UK
| | - Danielle Deuker
- Milner Centre of Evolution, University of Bath, Claverton Down, Bath, UK.,Present address: Nuffield Department of Medicine, Jenner Institute, University of Oxford, Oxford, UK
| | - Sunny Smith
- Milner Centre of Evolution, University of Bath, Claverton Down, Bath, UK
| | - Harry Wickenden
- Milner Centre of Evolution, University of Bath, Claverton Down, Bath, UK
| | | | - Samuel K Sheppard
- Milner Centre of Evolution, University of Bath, Claverton Down, Bath, UK.,Department of Zoology, University of Oxford, Oxford, UK
| | - Mohamed Elhadidy
- Biomedical Sciences Program, University of Science and Technology, Zewail City of Science and Technology, Giza, Egypt.,Department of Bacteriology, Mycology and Immunology, Faculty of Veterinary Medicine, Mansoura University, Mansoura, Egypt
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15
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Brockhurst MA, Harrison E. Ecological and evolutionary solutions to the plasmid paradox. Trends Microbiol 2021; 30:534-543. [PMID: 34848115 DOI: 10.1016/j.tim.2021.11.001] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 10/07/2021] [Accepted: 11/03/2021] [Indexed: 12/22/2022]
Abstract
The 'plasmid paradox' arises because, although plasmids are common features of bacterial genomes, theoretically they should not exist: rates of conjugation were believed insufficient to allow plasmids to persist by infectious transmission, whereas the costs of plasmid maintenance meant that plasmids should be purged by negative selection regardless of whether they encoded beneficial accessory traits because these traits should eventually be captured by the chromosome, enabling the loss of the redundant plasmid. In the decade since the plasmid paradox was described, new data and theory show that a range of ecological and evolutionary mechanisms operate in bacterial populations and communities to explain the widespread distribution and stable maintenance of plasmids. We conclude, therefore, that multiple solutions to the plasmid paradox are now well understood. The current challenge for the field, however, is to better understand how these solutions operate in natural bacterial communities to explain and predict the distribution of plasmids and the dynamics of the horizontal gene transfer that they mediate in bacterial (pan)genomes.
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Affiliation(s)
- Michael A Brockhurst
- Division of Evolution and Genomic Sciences, Faculty of Biology, Medicine, and Health, The University of Manchester, Manchester, M13 9PT, UK.
| | - Ellie Harrison
- Department of Animal and Plant Sciences, The University of Sheffield, Sheffield, S10 2TN, UK
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16
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Singh NK, Karisto P, Croll D. Population-level deep sequencing reveals the interplay of clonal and sexual reproduction in the fungal wheat pathogen Zymoseptoria tritici. Microb Genom 2021; 7. [PMID: 34617882 PMCID: PMC8627204 DOI: 10.1099/mgen.0.000678] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Pathogens cause significant challenges to global food security. On annual crops, pathogens must re-infect from environmental sources in every growing season. Fungal pathogens have evolved mixed reproductive strategies to cope with the distinct challenges of colonizing growing plants. However, how pathogen diversity evolves during growing seasons remains largely unknown. Here, we performed a deep hierarchical sampling in a single experimental wheat field infected by the major fungal pathogen Zymoseptoria tritici. We analysed whole genome sequences of 177 isolates collected from 12 distinct cultivars replicated in space at three time points of the growing season to maximize capture of genetic diversity. The field population was highly diverse with 37 SNPs per kilobase, a linkage disequilibrium decay within 200-700 bp and a high effective population size. Using experimental infections, we tested a subset of the collected isolates on the dominant cultivar planted in the field. However, we found no significant difference in virulence of isolates collected from the same cultivar compared to isolates collected on other cultivars. About 20 % of the isolate genotypes were grouped into 15 clonal groups. Pairs of clones were disproportionally found at short distances (<5 m), consistent with experimental estimates for per-generation dispersal distances performed in the same field. This confirms predominant leaf-to-leaf transmission during the growing season. Surprisingly, levels of clonality did not increase over time in the field although reproduction is thought to be exclusively asexual during the growing season. Our study shows that the pathogen establishes vast and stable gene pools in single fields. Monitoring short-term evolutionary changes in crop pathogens will inform more durable strategies to contain diseases.
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Affiliation(s)
- Nikhil Kumar Singh
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, 2000 Neuchâtel, Switzerland
| | - Petteri Karisto
- Plant Health, Natural Resources Institute Finland (Luke), Jokioinen, Finland
| | - Daniel Croll
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, 2000 Neuchâtel, Switzerland
- *Correspondence: Daniel Croll,
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17
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Agarwal G, Gitaitis RD, Dutta B. Pan-Genome of Novel Pantoea stewartii subsp. indologenes Reveals Genes Involved in Onion Pathogenicity and Evidence of Lateral Gene Transfer. Microorganisms 2021; 9:1761. [PMID: 34442840 PMCID: PMC8399035 DOI: 10.3390/microorganisms9081761] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 08/11/2021] [Accepted: 08/12/2021] [Indexed: 11/16/2022] Open
Abstract
Pantoea stewartii subsp. indologenes (Psi) is a causative agent of leafspot on foxtail millet and pearl millet; however, novel strains were recently identified that are pathogenic on onions. Our recent host range evaluation study identified two pathovars; P. stewartii subsp. indologenes pv. cepacicola pv. nov. and P. stewartii subsp. indologenes pv. setariae pv. nov. that are pathogenic on onions and millets or on millets only, respectively. In the current study, we developed a pan-genome using the whole genome sequencing of newly identified/classified Psi strains from both pathovars [pv. cepacicola (n = 4) and pv. setariae (n = 13)]. The full spectrum of the pan-genome contained 7030 genes. Among these, 3546 (present in genomes of all 17 strains) were the core genes that were a subset of 3682 soft-core genes (present in ≥16 strains). The accessory genome included 1308 shell genes and 2040 cloud genes (present in ≤2 strains). The pan-genome showed a clear linear progression with >6000 genes, suggesting that the pan-genome of Psi is open. Comparative phylogenetic analysis showed differences in phylogenetic clustering of Pantoea spp. using PAVs/wgMLST approach in comparison with core genome SNPs-based phylogeny. Further, we conducted a horizontal gene transfer (HGT) study using Psi strains from both pathovars along with strains from other Pantoea species, namely, P. stewartii subsp. stewartii LMG 2715T, P. ananatis LMG 2665T, P. agglomerans LMG L15, and P. allii LMG 24248T. A total of 317 HGT events among four Pantoea species were identified with most gene transfer events occurring between Psi pv. cepacicola and Psi pv. setariae. Pan-GWAS analysis predicted a total of 154 genes, including seven gene-clusters, which were associated with the pathogenicity phenotype (necrosis on seedling) on onions. One of the gene-clusters contained 11 genes with known functions and was found to be chromosomally located.
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Affiliation(s)
- Gaurav Agarwal
- Department of Plant Pathology, Coastal Plain Experiment Station, University of Georgia, Tifton, GA 31793, USA;
| | | | - Bhabesh Dutta
- Department of Plant Pathology, Coastal Plain Experiment Station, University of Georgia, Tifton, GA 31793, USA;
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18
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Mateo-Estrada V, Fernández-Vázquez JL, Moreno-Manjón J, Hernández-González IL, Rodríguez-Noriega E, Morfín-Otero R, Alcántar-Curiel MD, Castillo-Ramírez S. Accessory Genomic Epidemiology of Cocirculating Acinetobacter baumannii Clones. mSystems 2021; 6:e0062621. [PMID: 34282943 DOI: 10.1128/mSystems.00626-21] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Acinetobacter baumannii has become one of the most important multidrug-resistant nosocomial pathogens all over the world. Nonetheless, very little is known about the diversity of A. baumannii lineages coexisting in hospital settings. Here, using whole-genome sequencing, epidemiological data, and antimicrobial susceptibility tests, we uncover the transmission dynamics of extensive and multidrug-resistant A. baumannii in a tertiary hospital over a decade. Our core genome phylogeny of almost 300 genomes suggests that there were several introductions of lineages from international clone 2 into the hospital. The molecular dating analysis shows that these introductions happened in 2006, 2007, and 2013. Furthermore, using the accessory genome, we show that these lineages were extensively disseminated across many wards in the hospital. Our results demonstrate that accessory genome variation can be a very powerful tool for conducting genomic epidemiology. We anticipate future studies employing the accessory genome along with the core genome as a powerful phylogenomic strategy to track bacterial transmissions over very short microevolutionary scales. IMPORTANCE Whole-genome sequencing for epidemiological investigations (genomic epidemiology) has been of paramount importance to understand the transmission dynamics of many bacterial (and nonbacterial) pathogens. Commonly, variation in the core genome, single nucleotide polymorphisms (SNPs), is employed to carry out genomic epidemiology. However, at very short periods of time, the core genome might not have accumulated enough variation (sufficient SNPs) to tell apart isolates. In this scenario, gene content variation in the accessory genome can be an option to conduct genomic epidemiology. Here, we used the accessory genome, as well as the core genome, to uncover the transmission dynamics of extensive and multidrug-resistant A. baumannii in a tertiary hospital for a decade. Our study shows that accessory genome variation can be a very powerful tool for conducting genomic epidemiology.
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Guardiola-Avila I, Sánchez-Busó L, Acedo-Félix E, Gomez-Gil B, Zúñiga-Cabrera M, González-Candelas F, Noriega-Orozco L. Core and Accessory Genome Analysis of Vibrio mimicus. Microorganisms 2021; 9:microorganisms9010191. [PMID: 33477474 PMCID: PMC7831076 DOI: 10.3390/microorganisms9010191] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 12/18/2020] [Accepted: 12/23/2020] [Indexed: 01/21/2023] Open
Abstract
Vibrio mimicus is an emerging pathogen, mainly associated with contaminated seafood consumption. However, little is known about its evolution, biodiversity, and pathogenic potential. This study analyzes the pan-, core, and accessory genomes of nine V. mimicus strains. The core genome yielded 2424 genes in chromosome I (ChI) and 822 genes in chromosome II (ChII), with an accessory genome comprising an average of 10.9% of the whole genome for ChI and 29% for ChII. Core genome phylogenetic trees were obtained, and V. mimicus ATCC-33654 strain was the closest to the outgroup in both chromosomes. Additionally, a phylogenetic study of eight conserved genes (ftsZ, gapA, gyrB, topA, rpoA, recA, mreB, and pyrH), including Vibrio cholerae, Vibrio parilis, Vibrio metoecus, and Vibrio caribbenthicus, clearly showed clade differentiation. The main virulence genes found in ChI corresponded with type I secretion proteins, extracellular components, flagellar proteins, and potential regulators, while, in ChII, the main categories were type-I secretion proteins, chemotaxis proteins, and antibiotic resistance proteins. The accessory genome was characterized by the presence of mobile elements and toxin encoding genes in both chromosomes. Based on the genome atlas, it was possible to characterize differential regions between strains. The pan-genome of V. mimicus encompassed 3539 genes for ChI and 2355 genes for ChII. These results give us an insight into the virulence and gene content of V. mimicus, as well as constitute the first approach to its diversity.
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Affiliation(s)
- Iliana Guardiola-Avila
- Centro de Investigación en Alimentación y Desarrollo, A.C. (CIAD), Hermosillo, Sonora 83304, Mexico; (I.G.-A.); (E.A.-F.)
| | - Leonor Sánchez-Busó
- Genomics and Health Area, Foundation for the Promotion of Health and Biomedical Research in the Valencian Community (FISABIO-Public Health), 46020 Valencia, Spain;
| | - Evelia Acedo-Félix
- Centro de Investigación en Alimentación y Desarrollo, A.C. (CIAD), Hermosillo, Sonora 83304, Mexico; (I.G.-A.); (E.A.-F.)
| | - Bruno Gomez-Gil
- Centro de Investigación en Alimentación y Desarrollo, A.C. (CIAD) Mazatlán, Unit for Aquaculture and Environmental Management, Mazatlan, Sinaloa 82112, Mexico;
| | - Manuel Zúñiga-Cabrera
- Instituto de Agroquímica y Tecnología de Alimentos (IATA-CSSIC), 46980 Paterna, Spain;
| | - Fernando González-Candelas
- Joint Research Unit Infección y Salud Pública, FISABIO-Universitat de Valencia, I2SysBio, CIBERESP, 46980 Valencia, Spain;
| | - Lorena Noriega-Orozco
- Guaymas Unit, Centro de Investigación en Alimentación y Desarrollo (CIAD), Guaymas, Sonora 85480, Mexico
- Correspondence: ; Tel.: +52-662-289-2400
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Costa SS, Guimarães LC, Silva A, Soares SC, Baraúna RA. First Steps in the Analysis of Prokaryotic Pan-Genomes. Bioinform Biol Insights 2020; 14:1177932220938064. [PMID: 32843837 PMCID: PMC7418249 DOI: 10.1177/1177932220938064] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 05/26/2020] [Indexed: 01/14/2023] Open
Abstract
Pan-genome is defined as the set of orthologous and unique genes of a specific group of organisms. The pan-genome is composed by the core genome, accessory genome, and species- or strain-specific genes. The pan-genome is considered open or closed based on the alpha value of the Heap law. In an open pan-genome, the number of gene families will continuously increase with the addition of new genomes to the analysis, while in a closed pan-genome, the number of gene families will not increase considerably. The first step of a pan-genome analysis is the homogenization of genome annotation. The same software should be used to annotate genomes, such as GeneMark or RAST. Subsequently, several software are used to calculate the pan-genome such as BPGA, GET_HOMOLOGUES, PGAP, among others. This review presents all these initial steps for those who want to perform a pan-genome analysis, explaining key concepts of the area. Furthermore, we present the pan-genomic analysis of 9 bacterial species. These are the species with the highest number of genomes deposited in GenBank. We also show the influence of the identity and coverage parameters on the prediction of orthologous and paralogous genes. Finally, we cite the perspectives of several research areas where pan-genome analysis can be used to answer important issues.
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Affiliation(s)
- Sávio Souza Costa
- Centro de Genômica e Biologia de Sistemas, Universidade Federal do Pará, Belém, Brazil
- Laboratório de Engenharia Biológica, Espaço Inovação, Parque de Ciência e Tecnologia Guamá, Belém, Brazil
| | - Luís Carlos Guimarães
- Centro de Genômica e Biologia de Sistemas, Universidade Federal do Pará, Belém, Brazil
| | - Artur Silva
- Centro de Genômica e Biologia de Sistemas, Universidade Federal do Pará, Belém, Brazil
- Laboratório de Engenharia Biológica, Espaço Inovação, Parque de Ciência e Tecnologia Guamá, Belém, Brazil
| | - Siomar Castro Soares
- Instituto de Ciências Biológicas e Naturais, Universidade Federal do Triângulo Mineiro, Uberaba, Brazil
| | - Rafael Azevedo Baraúna
- Centro de Genômica e Biologia de Sistemas, Universidade Federal do Pará, Belém, Brazil
- Laboratório de Engenharia Biológica, Espaço Inovação, Parque de Ciência e Tecnologia Guamá, Belém, Brazil
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21
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Álvarez VE, Quiroga MP, Galán AV, Vilacoba E, Quiroga C, Ramírez MS, Centrón D. Crucial Role of the Accessory Genome in the Evolutionary Trajectory of Acinetobacter baumannii Global Clone 1. Front Microbiol 2020; 11:342. [PMID: 32256462 PMCID: PMC7093585 DOI: 10.3389/fmicb.2020.00342] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 02/17/2020] [Indexed: 01/08/2023] Open
Abstract
Acinetobacter baumannii is one of the most important nosocomial pathogens able to rapidly develop extensive drug resistance. Here, we study the role of accessory genome in the success of the globally disseminated clone 1 (GC1) with functional and genomic approaches. Comparative genomics was performed with available GC1 genomes (n = 106) against other A. baumannii high-risk and sporadic clones. Genetic traits related to accessory genome were found common and conserved along time as two novel regions of genome plasticity, and a CRISPR-Cas system acquired before clonal diversification located at the same loci as “sedentary” modules. Although identified within hotspot for recombination, other block of accessory genome was also “sedentary” in lineage 1 of GC1 with signs of microevolution as the AbaR0-type genomic island (GI) identified in A144 and in A155 strains which were maintained one month in independent experiments without antimicrobial pressure. The prophage YMC/09/02/B1251_ABA_BP was found to be “mobile” since, although it was shared by all GC1 genomes, it showed high intrinsic microevolution as well as mobility to different insertion sites. Interestingly, a wide variety of Insertion Sequences (IS), probably acquired by the flow of plasmids related to Rep_3 superfamily was found. These IS showed dissimilar genomic location amongst GC1 genomes presumably associated with promptly niche adaptation. On the other hand, a type VI secretion system and three efflux pumps were subjected to deep processes of genomic loss in A. baumannii but not in GC1. As a whole, these findings suggest that preservation of some genetic modules of accessory genome harbored by strains from different continents in combination with great plasticity of IS and varied flow of plasmids, may be central features of the genomic structure of GC1. Competition of A144 and A155 versus A118 (ST 404/ND) without antimicrobial pressure suggested a higher ability of GC1 to grow over a clone with sporadic behavior which explains, from an ecological perspective, the global achievement of this successful pandemic clone in the hospital habitat. Together, these data suggest an essential role of still unknown properties of “mobile” and “sedentary” accessory genome that is preserved over time under different antibiotic or stress conditions.
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Affiliation(s)
- Verónica Elizabeth Álvarez
- Laboratorio de Investigaciones en Mecanismos de Resistencia a Antibióticos, Instituto de Investigaciones en Microbiología y Parasitología Médica, Facultad de Medicina, Universidad de Buenos Aires - Consejo Nacional de Investigaciones Científicas y Tecnológicas (IMPaM, UBA-CONICET), Buenos Aires, Argentina
| | - María Paula Quiroga
- Laboratorio de Investigaciones en Mecanismos de Resistencia a Antibióticos, Instituto de Investigaciones en Microbiología y Parasitología Médica, Facultad de Medicina, Universidad de Buenos Aires - Consejo Nacional de Investigaciones Científicas y Tecnológicas (IMPaM, UBA-CONICET), Buenos Aires, Argentina
| | - Angélica Viviana Galán
- Laboratorio de Investigaciones en Mecanismos de Resistencia a Antibióticos, Instituto de Investigaciones en Microbiología y Parasitología Médica, Facultad de Medicina, Universidad de Buenos Aires - Consejo Nacional de Investigaciones Científicas y Tecnológicas (IMPaM, UBA-CONICET), Buenos Aires, Argentina
| | - Elisabet Vilacoba
- Laboratorio de Investigaciones en Mecanismos de Resistencia a Antibióticos, Instituto de Investigaciones en Microbiología y Parasitología Médica, Facultad de Medicina, Universidad de Buenos Aires - Consejo Nacional de Investigaciones Científicas y Tecnológicas (IMPaM, UBA-CONICET), Buenos Aires, Argentina
| | - Cecilia Quiroga
- Instituto de Investigaciones en Microbiología y Parasitología Médica, Facultad de Medicina, Universidad de Buenos Aires - Consejo Nacional de Investigaciones Científicas y Tecnológicas (IMPaM, UBA-CONICET), Buenos Aires, Argentina
| | - María Soledad Ramírez
- Center for Applied Biotechnology Studies, Department of Biological Science, California State University Fullerton, Fullerton, CA, United States
| | - Daniela Centrón
- Laboratorio de Investigaciones en Mecanismos de Resistencia a Antibióticos, Instituto de Investigaciones en Microbiología y Parasitología Médica, Facultad de Medicina, Universidad de Buenos Aires - Consejo Nacional de Investigaciones Científicas y Tecnológicas (IMPaM, UBA-CONICET), Buenos Aires, Argentina
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22
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Freitas AR, Tedim AP, Novais C, Lanza VF, Peixe L. Comparative genomics of global optrA-carrying Enterococcus faecalis uncovers a common chromosomal hotspot for optrA acquisition within a diversity of core and accessory genomes. Microb Genom 2020; 6. [PMID: 32149599 PMCID: PMC7371108 DOI: 10.1099/mgen.0.000350] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Linezolid-resistant Enterococcus faecalis (LREfs) carrying optrA are increasingly reported globally from multiple sources, but we lack a comprehensive analysis of human and animal optrA-LREfs strains. To assess if optrA is dispersed in isolates with varied genetic backgrounds or with common genetic features, we investigated the phylogenetic structure, genetic content [antimicrobial resistance (AMR), virulence, prophages, plasmidome] and optrA-containing platforms of 27 publicly available optrA-positive E. faecalis genomes from different hosts in seven countries. At the genome-level analysis, an in-house database with 64 virulence genes was tested for the first time. Our analysis showed a diversity of clones and adaptive gene sequences related to a wide range of genera from Firmicutes. Phylogenies of core and accessory genomes were not congruent, and at least PAI-associated and prophage genes contribute to such differences. Epidemiologically unrelated clones (ST21, ST476-like and ST489) obtained from human clinical and animal hosts in different continents over eight years (2010–2017) could be phylogenetically related (3–126 SNPs difference). optrA was located on the chromosome within a Tn6674-like element (n=10) or on medium-size plasmids (30–60 kb; n=14) belonging to main plasmid families (RepA_N/Inc18/Rep_3). In most cases, the immediate gene vicinity of optrA was generally identical in chromosomal (Tn6674) or plasmid (impB-fexA-optrA) backbones. Tn6674 was always inserted into the same ∆radC integration site and embedded in a 32 kb chromosomal platform common to strains from different origins (patients, healthy humans, and animals) in Europe, Africa, and Asia during 2012–2017. This platform is conserved among hundreds of E. faecalis genomes and proposed as a chromosomal hotspot for optrA integration. The finding of optrA in strains sharing common adaptive features and genetic backgrounds across different hosts and countries suggests the occurrence of common and independent genetic events occurring in distant regions and might explain the easy de novo generation of optrA-positive strains. It also anticipates a dramatic increase of optrA carriage and spread with a serious impact on the efficacy of linezolid for the treatment of Gram-positive infections.
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Affiliation(s)
- Ana R Freitas
- UCIBIO/REQUIMTE. Departamento de Ciências Biológicas. Laboratório de Microbiologia. Faculdade de Farmácia. Universidade do Porto. Porto, Porto, Portugal
| | - Ana P Tedim
- Grupo de Investigación Biomédica en Sepsis - BioSepsis. Hospital Universitario Río Hortega, Instituto de Investigación Biomédica de Salamanca (IBSAL), Valladollid, Spain
| | - Carla Novais
- UCIBIO/REQUIMTE. Departamento de Ciências Biológicas. Laboratório de Microbiologia. Faculdade de Farmácia. Universidade do Porto. Porto, Porto, Portugal
| | - Val F Lanza
- Departamento de Bioinformática. Hospital Universitario Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
| | - Luísa Peixe
- UCIBIO/REQUIMTE. Departamento de Ciências Biológicas. Laboratório de Microbiologia. Faculdade de Farmácia. Universidade do Porto. Porto, Porto, Portugal
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Barton IS, Platt TG, Rusch DB, Fuqua C. Destabilization of the Tumor-Inducing Plasmid from an Octopine-Type Agrobacterium tumefaciens Lineage Drives a Large Deletion in the Co-resident At Megaplasmid. G3 (Bethesda) 2019; 9:3489-500. [PMID: 31451548 DOI: 10.1534/g3.119.400554] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Bacteria with multi-replicon genome organizations, including members of the family Rhizobiaceae, often carry a variety of niche-associated functions on large plasmids. While evidence exists for cross-replicon interactions and co-evolution between replicons in many of these systems, remarkable strain-to-strain variation is also observed for extrachromosomal elements, suggesting increased genetic plasticity. Here, we show that curing of the tumor-inducing virulence plasmid (pTi) of an octopine-type Agrobacterium tumefaciens lineage leads to a large deletion in the co-resident At megaplasmid (pAt). The deletion event is mediated by a repetitive IS-element, IS66, and results in a variety of environment-dependent fitness consequences, including loss of independent conjugal transfer of the plasmid. Interestingly, a related and otherwise wild-type A. tumefaciens strain is missing exactly the same large pAt segment as the pAt deletion derivatives, suggesting a similar event over its natural history. Overall, the findings presented here uncover a novel genetic interaction between the two large plasmids of A. tumefaciens and provide evidence for cross-replicon integration and co-evolution of these plasmids.
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24
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Ozer EA, Nnah E, Didelot X, Whitaker RJ, Hauser AR. The Population Structure of Pseudomonas aeruginosa Is Characterized by Genetic Isolation of exoU+ and exoS+ Lineages. Genome Biol Evol 2019; 11:1780-1796. [PMID: 31173069 PMCID: PMC6690169 DOI: 10.1093/gbe/evz119] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/05/2019] [Indexed: 02/06/2023] Open
Abstract
The diversification of microbial populations may be driven by many factors including adaptation to distinct ecological niches and barriers to recombination. We examined the population structure of the bacterial pathogen Pseudomonas aeruginosa by analyzing whole-genome sequences of 739 isolates from diverse sources. We confirmed that the population structure of P. aeruginosa consists of two major groups (referred to as Groups A and B) and at least two minor groups (Groups C1 and C2). Evidence for frequent intragroup but limited intergroup recombination in the core genome was observed, consistent with sexual isolation of the groups. Likewise, accessory genome analysis demonstrated more gene flow within Groups A and B than between these groups, and a few accessory genomic elements were nearly specific to one or the other group. In particular, the exoS gene was highly overrepresented in Group A compared with Group B isolates (99.4% vs. 1.1%) and the exoU gene was highly overrepresented in Group B compared with Group A isolates (95.2% vs. 1.8%). The exoS and exoU genes encode effector proteins secreted by the P. aeruginosa type III secretion system. Together these results suggest that the major P. aeruginosa groups defined in part by the exoS and exoU genes are divergent from each other, and that these groups are genetically isolated and may be ecologically distinct. Although both groups were globally distributed and caused human infections, certain groups predominated in some clinical contexts.
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Affiliation(s)
- Egon A Ozer
- Division of Infectious Diseases, Department of Medicine, Northwestern University Feinberg School of Medicine
| | - Ekpeno Nnah
- Lurie Children's Hospital, Chicago, Illinois
| | - Xavier Didelot
- School of Life Sciences and Department of Statistics, University of Warwick, Coventry, United Kingdom
| | - Rachel J Whitaker
- Department of Microbiology and the Carl R. Woese Institute of Genomic Biology, University of Illinois, Urbana-Champaign
| | - Alan R Hauser
- Division of Infectious Diseases, Department of Medicine, Northwestern University Feinberg School of Medicine.,Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine
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Harter E, Lassnig C, Wagner EM, Zaiser A, Wagner M, Rychli K. The Novel Internalins InlP1 and InlP4 and the Internalin-Like Protein InlP3 Enhance the Pathogenicity of Listeria monocytogenes. Front Microbiol 2019; 10:1644. [PMID: 31396177 PMCID: PMC6664051 DOI: 10.3389/fmicb.2019.01644] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 07/03/2019] [Indexed: 01/08/2023] Open
Abstract
The pathogenicity of the human foodborne pathogen Listeria monocytogenes relies on virulence factors such as internalins. In 2009/2010 two L. monocytogenes strains were responsible for a serious listeriosis outbreak in Austria, Germany, and the Czech Republic. One of these clones, QOC1, which caused 14 cases including five fatalities, encodes the novel internalins inlP1, inlPq and inlP4, and the novel internalin-like protein inlP3 in the genomic region of hypervariable genetic hotspot 9 in addition to the standard set of virulence genes. The in silico prevalence study revealed that these genes rarely occur in L. monocytogenes, mainly in minor clonal complexes. To obtain first insights of the role of these genes in the pathogenicity of L. monocytogenes, we studied the gene expression under conditions mimicking the ingestion in the host. Expression of inlP1, inlP3, inlPq and inlP4 was increased under gastric stress and in intracellular bacteria grown in intestinal epithelial cells. Furthermore, colonization of the liver and the spleen was slightly, but significantly reduced 72 h post infection in an oral mouse infection model when inlP1 or inlP4 was deleted. Moreover, the impact of InlP1 and InlP3 in virulence was shown in vitro in human intestinal epithelial cells. In this study we conclusively demonstrate a potential contribution of uncommon novel internalins and an internalin-like protein to the pathogenicity of L. monocytogenes.
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Affiliation(s)
- Eva Harter
- Department for Farm Animals and Public Health in Veterinary Medicine, Institute of Food Safety, Food Technology and Veterinary Public Health, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Caroline Lassnig
- Department of Biomedical Sciences, Institute of Animal Breeding and Genetics and Biomodels Austria, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Eva Maria Wagner
- Department for Farm Animals and Public Health in Veterinary Medicine, Institute of Food Safety, Food Technology and Veterinary Public Health, University of Veterinary Medicine Vienna, Vienna, Austria.,Austrian Competence Centre for Feed and Food Quality, Safety and Innovation - FFoQSI GmbH, Tulln, Austria
| | - Andreas Zaiser
- Department for Farm Animals and Public Health in Veterinary Medicine, Institute of Food Safety, Food Technology and Veterinary Public Health, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Martin Wagner
- Department for Farm Animals and Public Health in Veterinary Medicine, Institute of Food Safety, Food Technology and Veterinary Public Health, University of Veterinary Medicine Vienna, Vienna, Austria.,Austrian Competence Centre for Feed and Food Quality, Safety and Innovation - FFoQSI GmbH, Tulln, Austria
| | - Kathrin Rychli
- Department for Farm Animals and Public Health in Veterinary Medicine, Institute of Food Safety, Food Technology and Veterinary Public Health, University of Veterinary Medicine Vienna, Vienna, Austria
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26
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Bayjanov JR, Baan J, Rogers MRC, Troelstra A, Willems RJL, van Schaik W. Enterococcus faecium genome dynamics during long-term asymptomatic patient gut colonization. Microb Genom 2019; 5:e000277. [PMID: 31166888 PMCID: PMC6700664 DOI: 10.1099/mgen.0.000277] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 05/24/2019] [Indexed: 11/18/2022] Open
Abstract
Enterococcus faecium is a gut commensal of humans and animals. In addition, it has recently emerged as an important nosocomial pathogen through the acquisition of genetic elements that confer resistance to antibiotics and virulence. We performed a whole-genome sequencing-based study on 96 multidrug-resistant E. faecium strains that asymptomatically colonized five patients with the aim of describing the genome dynamics of this species. The patients were hospitalized on multiple occasions and isolates were collected over periods ranging from 15 months to 6.5 years. Ninety-five of the sequenced isolates belonged to E. faecium clade A1, which was previously determined to be responsible for the vast majority of clinical infections. The clade A1 strains clustered into six clonal groups of highly similar isolates, three of which consisted entirely of isolates from a single patient. We also found evidence of concurrent colonization of patients by multiple distinct lineages and transfer of strains between patients during hospitalization. We estimated the evolutionary rate of two clonal groups that each colonized single patients at 12.6 and 25.2 single-nucleotide polymorphisms (SNPs)/genome/year. A detailed analysis of the accessory genome of one of the clonal groups revealed considerable variation due to gene gain and loss events, including the chromosomal acquisition of a 37 kbp prophage and the loss of an element containing carbohydrate metabolism-related genes. We determined the presence and location of 12 different insertion sequence (IS) elements, with ISEfa5 showing a unique pattern of location in 24 of the 25 isolates, suggesting widespread ISEfa5 excision and insertion into the genome during gut colonization. Our findings show that the E. faecium genome is highly dynamic during asymptomatic colonization of the human gut. We observed considerable genomic flexibility due to frequent horizontal gene transfer and recombination, which can contribute to the generation of genetic diversity within the species and, ultimately, can contribute to its success as a nosocomial pathogen.
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Affiliation(s)
- Jumamurat R. Bayjanov
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
| | - Jery Baan
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
| | - Malbert R. C. Rogers
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
| | - Annet Troelstra
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
| | - Rob J. L. Willems
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
| | - Willem van Schaik
- Department of Medical Microbiology, University Medical Center Utrecht, 3584CX Utrecht, The Netherlands
- Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
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27
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Park CJ, Andam CP. Within-Species Genomic Variation and Variable Patterns of Recombination in the Tetracycline Producer Streptomyces rimosus. Front Microbiol 2019; 10:552. [PMID: 30949149 PMCID: PMC6437091 DOI: 10.3389/fmicb.2019.00552] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 03/04/2019] [Indexed: 01/09/2023] Open
Abstract
Streptomyces rimosus is best known as the primary source of the tetracycline class of antibiotics, most notably oxytetracycline, which have been widely used against many gram-positive and gram-negative pathogens and protozoan parasites. However, despite the medical and agricultural importance of S. rimosus, little is known of its evolutionary history and genome dynamics. In this study, we aim to elucidate the pan-genome characteristics and phylogenetic relationships of 32 S. rimosus genomes. The S. rimosus pan-genome contains more than 22,000 orthologous gene clusters, and approximately 8.8% of these genes constitutes the core genome. A large part of the accessory genome is composed of 9,646 strain-specific genes. S. rimosus exhibits an open pan-genome (decay parameter α = 0.83) and high gene diversity between strains (genomic fluidity φ = 0.12). We also observed strain-level variation in the distribution and abundance of biosynthetic gene clusters (BGCs) and that each individual S. rimosus genome has a unique repertoire of BGCs. Lastly, we observed variation in recombination, with some strains donating or receiving DNA more often than others, strains that tend to frequently recombine with specific partners, genes that often experience recombination more than others, and variable sizes of recombined DNA sequences. We conclude that the high levels of inter-strain genomic variation in S. rimosus is partly explained by differences in recombination among strains. These results have important implications on current efforts for natural drug discovery, the ecological role of strain-level variation in microbial populations, and addressing the fundamental question of why microbes have pan-genomes.
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Affiliation(s)
- Cooper J Park
- Department of Molecular, Cellular, and Biomedical Sciences, University of New Hampshire, Durham, NH, United States
| | - Cheryl P Andam
- Department of Molecular, Cellular, and Biomedical Sciences, University of New Hampshire, Durham, NH, United States
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28
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van Tonder AJ, Bray JE, Jolley KA, Jansen van Rensburg M, Quirk SJ, Haraldsson G, Maiden MCJ, Bentley SD, Haraldsson Á, Erlendsdóttir H, Kristinsson KG, Brueggemann AB. Genomic Analyses of >3,100 Nasopharyngeal Pneumococci Revealed Significant Differences Between Pneumococci Recovered in Four Different Geographical Regions. Front Microbiol 2019; 10:317. [PMID: 30858837 PMCID: PMC6398412 DOI: 10.3389/fmicb.2019.00317] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 02/06/2019] [Indexed: 01/11/2023] Open
Abstract
Understanding the structure of a bacterial population is essential in order to understand bacterial evolution. Estimating the core genome (those genes common to all, or nearly all, strains of a species) is a key component of such analyses. The size and composition of the core genome varies by dataset, but we hypothesized that the variation between different collections of the same bacterial species would be minimal. To investigate this, we analyzed the genome sequences of 3,118 pneumococci recovered from healthy individuals in Reykjavik (Iceland), Southampton (United Kingdom), Boston (United States), and Maela (Thailand). The analyses revealed a “supercore” genome (genes shared by all 3,118 pneumococci) of 558 genes, although an additional 354 core genes were shared by pneumococci from Reykjavik, Southampton, and Boston. Overall, the size and composition of the core and pan-genomes among pneumococci recovered in Reykjavik, Southampton, and Boston were similar. Maela pneumococci were distinctly different in that they had a smaller core genome and larger pan-genome. The pan-genome of Maela pneumococci contained several >25 Kb sequence regions (flanked by pneumococcal genes) that were homologous to genomic regions found in other bacterial species. Overall, our work revealed that some subsets of the global pneumococcal population are highly heterogeneous, and our hypothesis was rejected. This is an important finding in terms of understanding genetic variation among pneumococci and is also an essential point of consideration before generalizing the findings from a single dataset to the wider pneumococcal population.
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Affiliation(s)
- Andries J van Tonder
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom.,Parasites and Microbes, Wellcome Sanger Institute, Hinxton, United Kingdom
| | - James E Bray
- Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Keith A Jolley
- Department of Zoology, University of Oxford, Oxford, United Kingdom
| | | | - Sigríður J Quirk
- Clinical Microbiology, University of Iceland and Landspitali University Hospital, Reykjavik, Iceland
| | - Gunnsteinn Haraldsson
- Clinical Microbiology, University of Iceland and Landspitali University Hospital, Reykjavik, Iceland
| | | | - Stephen D Bentley
- Parasites and Microbes, Wellcome Sanger Institute, Hinxton, United Kingdom.,Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom.,Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Ásgeir Haraldsson
- Children's Hospital Iceland, Landspitali University Hospital, Reykjavik, Iceland
| | - Helga Erlendsdóttir
- Clinical Microbiology, University of Iceland and Landspitali University Hospital, Reykjavik, Iceland
| | - Karl G Kristinsson
- Clinical Microbiology, University of Iceland and Landspitali University Hospital, Reykjavik, Iceland
| | - Angela B Brueggemann
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom.,Department of Medicine, Imperial College London, London, United Kingdom
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Davidson RM. A Closer Look at the Genomic Variation of Geographically Diverse Mycobacterium abscessus Clones That Cause Human Infection and Disease. Front Microbiol 2018; 9:2988. [PMID: 30568642 PMCID: PMC6290055 DOI: 10.3389/fmicb.2018.02988] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 11/19/2018] [Indexed: 01/15/2023] Open
Abstract
Mycobacterium abscessus is a multidrug resistant bacterium that causes pulmonary and extrapulmonary disease. The reported prevalence of pulmonary M. abscessus infections appears to be increasing in the United States (US) and around the world. In the last five years, multiple studies have utilized whole genome sequencing to investigate the genetic epidemiology of two clinically relevant subspecies, M. abscessus subsp. abscessus (MAB) and M. abscessus subsp. massiliense (MMAS). Phylogenomic comparisons of clinical isolates revealed that substantial proportions of patients have MAB and MMAS isolates that belong to genetically similar clusters also known as ‘dominant clones’. Unlike the genetic lineages of Mycobacterium tuberculosis that tend to be geographically clustered, the MAB and MMAS clones have been found in clinical populations from the US, Europe, Australia and South America. Moreover, the clones have been associated with worse clinical outcomes and show increased pathogenicity in macrophage and mouse models. While some have suggested that they may have spread locally and then globally through ‘indirect transmission’ within cystic fibrosis (CF) clinics, isolates of these clones have also been associated with sporadic pulmonary infections in non-CF patients and unrelated hospital-acquired soft tissue infections. M. abscessus has long been thought to be acquired from the environment, but the prevalence, exposure risk and environmental reservoirs of the dominant clones are currently not known. This review summarizes the genomic studies of M. abscessus and synthesizes the current knowledge surrounding the geographically diverse dominant clones identified from patient samples. Furthermore, it discusses the limitations of core genome comparisons for studying these genetically similar isolates and explores the breadth of accessory genome variation that has been observed to date. The combination of both core and accessory genome variation among these isolates may be the key to elucidating the origin, spread and evolution of these frequent genotypes.
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Affiliation(s)
- Rebecca M Davidson
- Center for Genes, Environment and Health, National Jewish Health, Denver, CO, United States
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30
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Checcucci A, diCenzo GC, Ghini V, Bazzicalupo M, Becker A, Decorosi F, Döhlemann J, Fagorzi C, Finan TM, Fondi M, Luchinat C, Turano P, Vignolini T, Viti C, Mengoni A. Creation and Characterization of a Genomically Hybrid Strain in the Nitrogen-Fixing Symbiotic Bacterium Sinorhizobium meliloti. ACS Synth Biol 2018; 7:2365-2378. [PMID: 30223644 DOI: 10.1021/acssynbio.8b00158] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Many bacteria, often associated with eukaryotic hosts and of relevance for biotechnological applications, harbor a multipartite genome composed of more than one replicon. Biotechnologically relevant phenotypes are often encoded by genes residing on the secondary replicons. A synthetic biology approach to developing enhanced strains for biotechnological purposes could therefore involve merging pieces or entire replicons from multiple strains into a single genome. Here we report the creation of a genomic hybrid strain in a model multipartite genome species, the plant-symbiotic bacterium Sinorhizobium meliloti. We term this strain as cis-hybrid, since it is produced by genomic material coming from the same species' pangenome. In particular, we moved the secondary replicon pSymA (accounting for nearly 20% of total genome content) from a donor S. meliloti strain to an acceptor strain. The cis-hybrid strain was screened for a panel of complex phenotypes (carbon/nitrogen utilization phenotypes, intra- and extracellular metabolomes, symbiosis, and various microbiological tests). Additionally, metabolic network reconstruction and constraint-based modeling were employed for in silico prediction of metabolic flux reorganization. Phenotypes of the cis-hybrid strain were in good agreement with those of both parental strains. Interestingly, the symbiotic phenotype showed a marked cultivar-specific improvement with the cis-hybrid strains compared to both parental strains. These results provide a proof-of-principle for the feasibility of genome-wide replicon-based remodelling of bacterial strains for improved biotechnological applications in precision agriculture.
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Affiliation(s)
- Alice Checcucci
- Department of Biology, University of Florence, 50019 Sesto Fiorentino, Italy
| | - George C. diCenzo
- Department of Biology, University of Florence, 50019 Sesto Fiorentino, Italy
| | - Veronica Ghini
- CERM & CIRMMP, University of Florence, 50019 Sesto Fiorentino, Italy
| | - Marco Bazzicalupo
- Department of Biology, University of Florence, 50019 Sesto Fiorentino, Italy
| | - Anke Becker
- LOEWE − Center for Synthetic Microbiology, 35043 Marburg, Germany
| | - Francesca Decorosi
- Department of Agri-food Production and Environmental Science, University of Florence, 50019 Florence, Italy
| | | | - Camilla Fagorzi
- Department of Biology, University of Florence, 50019 Sesto Fiorentino, Italy
| | - Turlough M. Finan
- Department of Biology, McMaster University, Hamilton, Ontario L8S 4L8, Canada
| | - Marco Fondi
- Department of Biology, University of Florence, 50019 Sesto Fiorentino, Italy
| | - Claudio Luchinat
- CERM & CIRMMP, University of Florence, 50019 Sesto Fiorentino, Italy
- CERM and Department of Chemistry, University of Florence, 50019 Sesto Fiorentino, Italy
| | - Paola Turano
- CERM & CIRMMP, University of Florence, 50019 Sesto Fiorentino, Italy
- CERM and Department of Chemistry, University of Florence, 50019 Sesto Fiorentino, Italy
| | - Tiziano Vignolini
- European Laboratory for Non-Linear Spectroscopy, LENS, 50019 Sesto Fiorentino, Italy
| | - Carlo Viti
- Department of Agri-food Production and Environmental Science, University of Florence, 50019 Florence, Italy
| | - Alessio Mengoni
- Department of Biology, University of Florence, 50019 Sesto Fiorentino, Italy
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31
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Hall JPJ, Brockhurst MA, Harrison E. Sampling the mobile gene pool: innovation via horizontal gene transfer in bacteria. Philos Trans R Soc Lond B Biol Sci 2018; 372:rstb.2016.0424. [PMID: 29061896 DOI: 10.1098/rstb.2016.0424] [Citation(s) in RCA: 104] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/05/2017] [Indexed: 12/26/2022] Open
Abstract
In biological systems, evolutionary innovations can spread not only from parent to offspring (i.e. vertical transmission), but also 'horizontally' between individuals, who may or may not be related. Nowhere is this more apparent than in bacteria, where novel ecological traits can spread rapidly within and between species through horizontal gene transfer (HGT). This important evolutionary process is predominantly a by-product of the infectious spread of mobile genetic elements (MGEs). We will discuss the ecological conditions that favour the spread of traits by HGT, the evolutionary and social consequences of sharing traits, and how HGT is shaped by inherent conflicts between bacteria and MGEs.This article is part of the themed issue 'Process and pattern in innovations from cells to societies'.
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Affiliation(s)
- James P J Hall
- Department of Animal and Plant Sciences, Alfred Denny Building, University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - Michael A Brockhurst
- Department of Animal and Plant Sciences, Alfred Denny Building, University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - Ellie Harrison
- P3 Institute, Department of Animal and Plant Sciences, Arthur Willis Environment Centre, University of Sheffield, 1 Maxfield Avenue, Sheffield S10 1AE, UK
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32
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Thorpe HA, Bayliss SC, Sheppard SK, Feil EJ. Piggy: a rapid, large-scale pan-genome analysis tool for intergenic regions in bacteria. Gigascience 2018; 7:1-11. [PMID: 29635296 PMCID: PMC5890482 DOI: 10.1093/gigascience/giy015] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Revised: 01/09/2018] [Accepted: 02/16/2018] [Indexed: 12/31/2022] Open
Abstract
Background The concept of the "pan-genome," which refers to the total complement of genes within a given sample or species, is well established in bacterial genomics. Rapid and scalable pipelines are available for managing and interpreting pan-genomes from large batches of annotated assemblies. However, despite overwhelming evidence that variation in intergenic regions in bacteria can directly influence phenotypes, most current approaches for analyzing pan-genomes focus exclusively on protein-coding sequences. Findings To address this we present Piggy, a novel pipeline that emulates Roary except that it is based only on intergenic regions. A key utility provided by Piggy is the detection of highly divergent ("switched") intergenic regions (IGRs) upstream of genes. We demonstrate the use of Piggy on large datasets of clinically important lineages of Staphylococcus aureus and Escherichia coli. Conclusions For S. aureus, we show that highly divergent (switched) IGRs are associated with differences in gene expression and we establish a multilocus reference database of IGR alleles (igMLST; implemented in BIGSdb).
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Affiliation(s)
- Harry A Thorpe
- The Milner Centre for Evolution, Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY
| | - Sion C Bayliss
- The Milner Centre for Evolution, Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY
| | - Samuel K Sheppard
- The Milner Centre for Evolution, Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY
| | - Edward J Feil
- The Milner Centre for Evolution, Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY
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33
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Knetsch CW, Kumar N, Forster SC, Connor TR, Browne HP, Harmanus C, Sanders IM, Harris SR, Turner L, Morris T, Perry M, Miyajima F, Roberts P, Pirmohamed M, Songer JG, Weese JS, Indra A, Corver J, Rupnik M, Wren BW, Riley TV, Kuijper EJ, Lawley TD. Zoonotic Transfer of Clostridium difficile Harboring Antimicrobial Resistance between Farm Animals and Humans. J Clin Microbiol 2018; 56:e01384-17. [PMID: 29237792 PMCID: PMC5824051 DOI: 10.1128/jcm.01384-17] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 12/08/2017] [Indexed: 11/20/2022] Open
Abstract
The emergence of Clostridium difficile as a significant human diarrheal pathogen is associated with the production of highly transmissible spores and the acquisition of antimicrobial resistance genes (ARGs) and virulence factors. Unlike the hospital-associated C. difficile RT027 lineage, the community-associated C. difficile RT078 lineage is isolated from both humans and farm animals; however, the geographical population structure and transmission networks remain unknown. Here, we applied whole-genome phylogenetic analysis of 248 C. difficile RT078 strains from 22 countries. Our results demonstrate limited geographical clustering for C. difficile RT078 and extensive coclustering of human and animal strains, thereby revealing a highly linked intercontinental transmission network between humans and animals. Comparative whole-genome analysis reveals indistinguishable accessory genomes between human and animal strains and a variety of antimicrobial resistance genes in the pangenome of C. difficile RT078. Thus, bidirectional spread of C. difficile RT078 between farm animals and humans may represent an unappreciated route disseminating antimicrobial resistance genes between humans and animals. These results highlight the importance of the "One Health" concept to monitor infectious disease emergence and the dissemination of antimicrobial resistance genes.
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Affiliation(s)
- C W Knetsch
- Section Experimental Bacteriology, Department of Medical Microbiology, Leiden University Medical Center, Leiden, Netherlands
| | - N Kumar
- Host-Microbiota Interactions Laboratory, Wellcome Trust Sanger Institute, Hinxton, United Kingdom
| | - S C Forster
- Host-Microbiota Interactions Laboratory, Wellcome Trust Sanger Institute, Hinxton, United Kingdom
- Centre for Innate Immunity and Infectious Diseases, Hudson Institute of Medical Research, Clayton, Victoria, Australia
- Department of Molecular and Translational Sciences, Monash University, Clayton, Victoria, Australia
| | - T R Connor
- Cardiff School of Biosciences, Sir Martin Evans Building, Cardiff, United Kingdom
| | - H P Browne
- Host-Microbiota Interactions Laboratory, Wellcome Trust Sanger Institute, Hinxton, United Kingdom
| | - C Harmanus
- Section Experimental Bacteriology, Department of Medical Microbiology, Leiden University Medical Center, Leiden, Netherlands
| | - I M Sanders
- Section Experimental Bacteriology, Department of Medical Microbiology, Leiden University Medical Center, Leiden, Netherlands
| | - S R Harris
- Pathogen Genomics, Wellcome Trust Sanger Institute, Hinxton, United Kingdom
| | - L Turner
- Public Health Wales, Microbiology, Wales, United Kingdom
| | - T Morris
- Public Health Wales, Microbiology, Wales, United Kingdom
| | - M Perry
- Public Health Wales, Microbiology, Wales, United Kingdom
| | - F Miyajima
- Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - P Roberts
- Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - M Pirmohamed
- Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - J G Songer
- Department of Veterinary Science and Microbiology, The University of Arizona, Tucson, Arizona, USA
| | - J S Weese
- Department of Pathobiology, Canada Veterinary College, University of Guelph, Guelph, Canada
| | - A Indra
- Institute of Medical Microbiology and Hygiene, Österreichische Agentur für Gesundheit und Ernährungssicherheit (AGES), Vienna, Austria
| | - J Corver
- Section Experimental Bacteriology, Department of Medical Microbiology, Leiden University Medical Center, Leiden, Netherlands
| | - M Rupnik
- Faculty of Medicine, University of Maribor, Maribor, Slovenia
- National Laboratory for Health, Environment and Food, Maribor, Slovenia
| | - B W Wren
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, University of London, London, United Kingdom
| | - T V Riley
- Department of Microbiology, PathWest Laboratory Medicine, Queen Elizabeth II Medical Centre, Western Australia, Australia
- Microbiology & Immunology, School of Pathology & Laboratory Medicine, The University of Western Australia, Western Australia, Australia
| | - E J Kuijper
- Section Experimental Bacteriology, Department of Medical Microbiology, Leiden University Medical Center, Leiden, Netherlands
| | - T D Lawley
- Host-Microbiota Interactions Laboratory, Wellcome Trust Sanger Institute, Hinxton, United Kingdom
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34
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Castillo D, Pérez-Reytor D, Plaza N, Ramírez-Araya S, Blondel CJ, Corsini G, Bastías R, Loyola DE, Jaña V, Pavez L, García K. Exploring the Genomic Traits of Non-toxigenic Vibrio parahaemolyticus Strains Isolated in Southern Chile. Front Microbiol 2018; 9:161. [PMID: 29472910 PMCID: PMC5809470 DOI: 10.3389/fmicb.2018.00161] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 01/24/2018] [Indexed: 01/30/2023] Open
Abstract
Vibrio parahaemolyticus is the leading cause of seafood-borne gastroenteritis worldwide. As reported in other countries, after the rise and fall of the pandemic strain in Chile, other post-pandemic strains have been associated with clinical cases, including strains lacking the major toxins TDH and TRH. Since the presence or absence of tdh and trh genes has been used for diagnostic purposes and as a proxy of the virulence of V. parahaemolyticus isolates, the understanding of virulence in V. parahaemolyticus strains lacking toxins is essential to detect these strains present in water and marine products to avoid possible food-borne infection. In this study, we characterized the genome of four environmental and two clinical non-toxigenic strains (tdh-, trh-, and T3SS2-). Using whole-genome sequencing, phylogenetic, and comparative genome analysis, we identified the core and pan-genome of V. parahaemolyticus of strains of southern Chile. The phylogenetic tree based on the core genome showed low genetic diversity but the analysis of the pan-genome revealed that all strains harbored genomic islands carrying diverse virulence and fitness factors or prophage-like elements that encode toxins like Zot and RTX. Interestingly, the three strains carrying Zot-like toxin have a different sequence, although the alignment showed some conserved areas with the zot sequence found in V. cholerae. In addition, we identified an unexpected diversity in the genetic architecture of the T3SS1 gene cluster and the presence of the T3SS2 gene cluster in a non-pandemic environmental strain. Our study sheds light on the diversity of V. parahaemolyticus strains from the southern Pacific which increases our current knowledge regarding the global diversity of this organism.
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Affiliation(s)
- Daniel Castillo
- Marine Biological Section, University of Copenhagen, Helsingør, Denmark
| | - Diliana Pérez-Reytor
- Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Santiago, Chile
| | - Nicolás Plaza
- Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Santiago, Chile
| | - Sebastián Ramírez-Araya
- Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Santiago, Chile.,Departamento de Ciencias Básicas, Facultad de Ciencias, Universidad Santo Tomás, Santiago, Chile
| | - Carlos J Blondel
- Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Santiago, Chile
| | - Gino Corsini
- Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Santiago, Chile
| | - Roberto Bastías
- Laboratory of Microbiology, Institute of Biology, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile
| | | | - Víctor Jaña
- Facultad de Medicina Veterinaria y Agronomía, Universidad de Las Américas, Santiago, Chile
| | - Leonardo Pavez
- Facultad de Medicina Veterinaria y Agronomía, Universidad de Las Américas, Santiago, Chile.,Departamento de Ciencias Químicas y Biológicas, Universidad Bernardo O'Higgins, Santiago, Chile
| | - Katherine García
- Instituto de Ciencias Biomédicas, Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Santiago, Chile
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35
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Lewis BB, Carter RA, Ling L, Leiner I, Taur Y, Kamboj M, Dubberke ER, Xavier J, Pamer EG. Pathogenicity Locus, Core Genome, and Accessory Gene Contributions to Clostridium difficile Virulence. mBio 2017; 8:e00885-17. [PMID: 28790208 DOI: 10.1128/mBio.00885-17] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Clostridium difficile is a spore-forming anaerobic bacterium that causes colitis in patients with disrupted colonic microbiota. While some individuals are asymptomatic C. difficile carriers, symptomatic disease ranges from mild diarrhea to potentially lethal toxic megacolon. The wide disease spectrum has been attributed to the infected host’s age, underlying diseases, immune status, and microbiome composition. However, strain-specific differences in C. difficile virulence have also been implicated in determining colitis severity. Because patients infected with C. difficile are unique in terms of medical history, microbiome composition, and immune competence, determining the relative contribution of C. difficile virulence to disease severity has been challenging, and conclusions regarding the virulence of specific strains have been inconsistent. To address this, we used a mouse model to test 33 clinical C. difficile strains isolated from patients with disease severities ranging from asymptomatic carriage to severe colitis, and we determined their relative in vivo virulence in genetically identical, antibiotic-pretreated mice. We found that murine infections with C. difficile clade 2 strains (including multilocus sequence type 1/ribotype 027) were associated with higher lethality and that C. difficile strains associated with greater human disease severity caused more severe disease in mice. While toxin production was not strongly correlated with in vivo colonic pathology, the ability of C. difficile strains to grow in the presence of secondary bile acids was associated with greater disease severity. Whole-genome sequencing and identification of core and accessory genes identified a subset of accessory genes that distinguish high-virulence from lower-virulence C. difficile strains. Clostridium difficile is an important cause of hospital-associated intestinal infections, and recent years have seen an increase in the number and severity of cases in the United States. A patient’s antibiotic history, immune status, and medical comorbidities determine, in part, the severity of C. difficile infection. The relative virulence of different clinical C. difficile strains, although postulated to determine disease severity in patients, has been more difficult to consistently associate with mild versus severe colitis. We tested 33 distinct clinical C. difficile isolates for their ability to cause disease in genetically identical mice and found that C. difficile strains belonging to clade 2 were associated with higher mortality. Differences in survival were not attributed to differences in toxin production but likely resulted from the distinct gene content in the various clinical isolates.
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36
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Cornick JE, Kiran AM, Vivancos R, Van Aartsen J, Clarke J, Bevan E, Alsahag M, Alaearts M, Bricio Moreno L, Jenkinson HF, Nobbs AH, Anson J, Kadioglu A, French N, Everett DB. Epidemiological and Molecular Characterization of an Invasive Group A Streptococcus emm32.2 Outbreak. J Clin Microbiol 2017; 55:1837-46. [PMID: 28356413 DOI: 10.1128/JCM.00191-17] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 03/21/2017] [Indexed: 01/11/2023] Open
Abstract
An emm32.2 invasive group A streptococcus (iGAS) outbreak occurred in Liverpool from January 2010 to September 2012. This genotype had not previously been identified in Liverpool, but was responsible for 32% (14/44) of all iGAS cases reported during this time period. We performed a case-case comparison of emm32.2 iGAS cases with non-emm32.2 control iGAS cases identified in the Liverpool population over the same time period to assess patient risk factors for emm32.2 iGAS infection. The emm32.2 iGAS cases were confined to the adult population. We show that homelessness, intravenous drug use, and alcohol abuse predisposed patients to emm32.2 iGAS disease; however, no obvious epidemiological linkage between the patients with emm32.2 iGAS could be identified. Comparative whole-genome sequencing analysis of emm32.2 iGAS and non-emm32.2 control isolates was also performed to identify pathogen factors which might have driven the outbreak. We identified 19 genes, five of which had previously been implicated in virulence, which were present in all of the emm32.2 iGAS isolates but not present in any of the non-emm32.2 control isolates. We report that a novel emm32.2 genotype emerged in Liverpool in 2010 and identified a specific subset of genes, which could have allowed this novel emm32.2 genotype to persist in a disadvantaged population in the region over a 3-year period.
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37
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Contreras-Moreira B, Cantalapiedra CP, García-Pereira MJ, Gordon SP, Vogel JP, Igartua E, Casas AM, Vinuesa P. Analysis of Plant Pan-Genomes and Transcriptomes with GET_HOMOLOGUES-EST, a Clustering Solution for Sequences of the Same Species. Front Plant Sci 2017; 8:184. [PMID: 28261241 PMCID: PMC5306281 DOI: 10.3389/fpls.2017.00184] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 01/30/2017] [Indexed: 05/22/2023]
Abstract
The pan-genome of a species is defined as the union of all the genes and non-coding sequences found in all its individuals. However, constructing a pan-genome for plants with large genomes is daunting both in sequencing cost and the scale of the required computational analysis. A more affordable alternative is to focus on the genic repertoire by using transcriptomic data. Here, the software GET_HOMOLOGUES-EST was benchmarked with genomic and RNA-seq data of 19 Arabidopsis thaliana ecotypes and then applied to the analysis of transcripts from 16 Hordeum vulgare genotypes. The goal was to sample their pan-genomes and classify sequences as core, if detected in all accessions, or accessory, when absent in some of them. The resulting sequence clusters were used to simulate pan-genome growth, and to compile Average Nucleotide Identity matrices that summarize intra-species variation. Although transcripts were found to under-estimate pan-genome size by at least 10%, we concluded that clusters of expressed sequences can recapitulate phylogeny and reproduce two properties observed in A. thaliana gene models: accessory loci show lower expression and higher non-synonymous substitution rates than core genes. Finally, accessory sequences were observed to preferentially encode transposon components in both species, plus disease resistance genes in cultivated barleys, and a variety of protein domains from other families that appear frequently associated with presence/absence variation in the literature. These results demonstrate that pan-genome analyses are useful to explore germplasm diversity.
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Affiliation(s)
- Bruno Contreras-Moreira
- Estación Experimental de Aula Dei - Consejo Superior de Investigaciones CientíficasZaragoza, Spain; Fundación ARAIDZaragoza, Spain
| | - Carlos P Cantalapiedra
- Estación Experimental de Aula Dei - Consejo Superior de Investigaciones Científicas Zaragoza, Spain
| | - María J García-Pereira
- Estación Experimental de Aula Dei - Consejo Superior de Investigaciones Científicas Zaragoza, Spain
| | | | - John P Vogel
- DOE Joint Genome Institute, Walnut Creek CA, USA
| | - Ernesto Igartua
- Estación Experimental de Aula Dei - Consejo Superior de Investigaciones Científicas Zaragoza, Spain
| | - Ana M Casas
- Estación Experimental de Aula Dei - Consejo Superior de Investigaciones Científicas Zaragoza, Spain
| | - Pablo Vinuesa
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México Cuernavaca, Mexico
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38
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Abstract
Shiga toxin-producing Escherichia coli O157:H7 primarily resides in cattle asymptomatically, and can be transmitted to humans through food. A study by Lupolova et al. applied a machine-learning approach to complex pan-genome information and predicted that only a small subset of bovine isolates have the potential to cause diseases in humans.
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Affiliation(s)
- Michelle Qiu Carter
- US Department of Agriculture, Agricultural Research Service, Western Regional Research Center, Produce Safety and Microbiology Research Unit, Albany, CA, USA.
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39
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Vos M, Hesselman MC, Te Beek TA, van Passel MWJ, Eyre-Walker A. Rates of Lateral Gene Transfer in Prokaryotes: High but Why? Trends Microbiol 2016; 23:598-605. [PMID: 26433693 DOI: 10.1016/j.tim.2015.07.006] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Revised: 07/01/2015] [Accepted: 07/20/2015] [Indexed: 12/12/2022]
Abstract
Lateral gene transfer is of fundamental importance to the evolution of prokaryote genomes and has important practical consequences, as evidenced by the rapid dissemination of antibiotic resistance and virulence determinants. Relatively little effort has so far been devoted to explicitly quantifying the rate at which accessory genes are taken up and lost, but it is possible that the combined rate of lateral gene transfer and gene loss is higher than that of point mutation. What evolutionary forces underlie the rate of lateral gene transfer are not well understood. We here use theory developed to explain the evolution of mutation rates to address this question and explore its consequences for the study of prokaryote evolution.
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Affiliation(s)
- Michiel Vos
- European Centre for Environment and Human Health, University of Exeter Medical School, University of Exeter, Penryn, UK.
| | | | - Tim A Te Beek
- Netherlands Bioinformatics Centre, Nijmegen, The Netherlands
| | - Mark W J van Passel
- Laboratory of Microbiology, Wageningen University, Wageningen, The Netherlands; Centre for Zoonoses and Environmental Microbiology, Centre for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
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40
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Michelacci V, Orsini M, Knijn A, Delannoy S, Fach P, Caprioli A, Morabito S. Development of a High Resolution Virulence Allelic Profiling (HReVAP) Approach Based on the Accessory Genome of Escherichia coli to Characterize Shiga-Toxin Producing E. coli (STEC). Front Microbiol 2016; 7:202. [PMID: 26941726 PMCID: PMC4763077 DOI: 10.3389/fmicb.2016.00202] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Accepted: 02/05/2016] [Indexed: 11/13/2022] Open
Abstract
Shiga-toxin producing Escherichia coli (STEC) strains possess a large accessory genome composed of virulence genes existing in multiple allelic variants, which sometimes segregate with specific STEC subpopulations. We analyzed the allelic variability of 91 virulence genes of STEC by Real Time PCR followed by melting curves analysis in 713 E. coli strains including 358 STEC. The 91 genes investigated were located on the locus of enterocyte effacement (LEE), OI-57, and OI-122 pathogenicity islands and displayed a total of 476 alleles in the study population. The combinations of the 91 alleles of each strain were termed allelic signatures and used to perform cluster analyses. We termed such an approach High Resolution Virulence Allelic Profiling (HReVAP) and used it to investigate the phylogeny of STEC of multiple serogroups. The dendrograms obtained identified groups of STEC segregating approximately with the serogroups and allowed the identification of subpopulations within the single groups. The study of the allelic signatures provided further evidence of the coevolution of the LEE and OI-122, reflecting the occurrence of their acquisition through a single event. The HReVAP analysis represents a sensitive tool for studying the evolution of LEE-positive STEC.
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Affiliation(s)
- Valeria Michelacci
- European Reference Laboratory for Escherichia coli, Dipartimento di Sanità Pubblica Veterinaria e Sicurezza Alimentare, Istituto Superiore di Sanità Rome, Italy
| | - Massimiliano Orsini
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise G. Caporale Teramo, Italy
| | - Arnold Knijn
- Servizio Informatico, Documentazione, Biblioteca e Attività Editoriali, Istituto Superiore di Sanità Rome, Italy
| | - Sabine Delannoy
- Platform IdentyPath, Food Safety Laboratory, ANSES, Université Paris-Est Maisons-Alfort, France
| | - Patrick Fach
- Platform IdentyPath, Food Safety Laboratory, ANSES, Université Paris-Est Maisons-Alfort, France
| | - Alfredo Caprioli
- European Reference Laboratory for Escherichia coli, Dipartimento di Sanità Pubblica Veterinaria e Sicurezza Alimentare, Istituto Superiore di Sanità Rome, Italy
| | - Stefano Morabito
- European Reference Laboratory for Escherichia coli, Dipartimento di Sanità Pubblica Veterinaria e Sicurezza Alimentare, Istituto Superiore di Sanità Rome, Italy
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41
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Abstract
Microbial communities can show astonishing ecological and phylogenetic diversity. What is the role of pervasive horizontal gene transfer (HGT) in shaping this diversity in the presence of clonally expanding “killer strains”? Does HGT of antibiotic production and resistance genes erase phylogenetic structure? To answer these questions, we study a spatial eco-evolutionary model of prokaryotes, inspired by recent findings on antagonistic interactions in Vibrionaceae populations. We find toxin genes evolve to be highly mobile, whereas resistance genes minimize mobility. This differential gene mobility is a requirement to maintain a diverse and dynamic ecosystem. The resistance gene repertoire acts as a core genome that corresponds to the phylogeny of cells, whereas toxin genes do not follow this phylogeny and have a patchy distribution. We also show that interstrain HGT makes the emergent phylogenetic structure robust to selective sweeps. Finally, in this evolved ecosystem we observe antagonistic interactions between, rather than within, spatially structure subpopulations, as has been previously observed for prokaryotes in soils and oceans. In contrast to ascribing the diversification and evolution of microbial communities to clonal dynamics, we show that multilevel evolution can elegantly explain the observed phylogenetic structure and ecosystem diversity.
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Affiliation(s)
- Bram van Dijk
- Department of Theoretical Biology and Bioinformatics, Utrecht University, The Netherlands
| | - Paulien Hogeweg
- Department of Theoretical Biology and Bioinformatics, Utrecht University, The Netherlands
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42
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Reuter S, Corander J, de Been M, Harris S, Cheng L, Hall M, Thomson NR, McNally A. Directional gene flow and ecological separation in Yersinia enterocolitica. Microb Genom 2015; 1:e000030. [PMID: 28348815 PMCID: PMC5320568 DOI: 10.1099/mgen.0.000030] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 08/09/2015] [Indexed: 01/07/2023] Open
Abstract
Yersinia enterocolitica is a common cause of food-borne gastroenteritis worldwide. Recent work defining the phylogeny of the genus Yersinia subdivided Y. enterocolitica into six distinct phylogroups. Here, we provide detailed analyses of the evolutionary processes leading to the emergence of these phylogroups. The dominant phylogroups isolated from human infections, PG3–5, show very little diversity at the sequence level, but do present marked patterns of gain and loss of functions, including those involved in pathogenicity and metabolism, including the acquisition of phylogroup-specific O-antigen loci. We tracked gene flow across the species in the core and accessory genome, and show that the non-pathogenic PG1 strains act as a reservoir for diversity, frequently acting as donors in recombination events. Analysis of the core and accessory genome also suggested that the different Y. enterocolitica phylogroups may be ecologically separated, in contrast to the long-held belief of common shared ecological niches across the Y. enterocolitica species.
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Affiliation(s)
- Sandra Reuter
- Pathogen Genomics, Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK.,Pathogen Research Group, Nottingham Trent University, Nottingham NG11 8NS, UK
| | - Jukka Corander
- Department of Mathematics and Statistics, University of Helsinki, Helsinki, Finland
| | - Mark de Been
- Department of Medical Microbiology, University Medical Centre Utrecht, Utrecht, Netherlands
| | - Simon Harris
- Pathogen Genomics, Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK
| | - Lu Cheng
- Department of Mathematics and Statistics, University of Helsinki, Helsinki, Finland
| | - Miquette Hall
- Pathogen Research Group, Nottingham Trent University, Nottingham NG11 8NS, UK
| | - Nicholas R Thomson
- Pathogen Genomics, Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK.,Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK
| | - Alan McNally
- Pathogen Research Group, Nottingham Trent University, Nottingham NG11 8NS, UK
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43
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Kumar N, Lad G, Giuntini E, Kaye ME, Udomwong P, Shamsani NJ, Young JPW, Bailly X. Bacterial genospecies that are not ecologically coherent: population genomics of Rhizobium leguminosarum. Open Biol 2015; 5:140133. [PMID: 25589577 PMCID: PMC4313370 DOI: 10.1098/rsob.140133] [Citation(s) in RCA: 105] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Biological species may remain distinct because of genetic isolation or ecological adaptation, but these two aspects do not always coincide. To establish the nature of the species boundary within a local bacterial population, we characterized a sympatric population of the bacterium Rhizobium leguminosarum by genomic sequencing of 72 isolates. Although all strains have 16S rRNA typical of R. leguminosarum, they fall into five genospecies by the criterion of average nucleotide identity (ANI). Many genes, on plasmids as well as the chromosome, support this division: recombination of core genes has been largely within genospecies. Nevertheless, variation in ecological properties, including symbiotic host range and carbon-source utilization, cuts across these genospecies, so that none of these phenotypes is diagnostic of genospecies. This phenotypic variation is conferred by mobile genes. The genospecies meet the Mayr criteria for biological species in respect of their core genes, but do not correspond to coherent ecological groups, so periodic selection may not be effective in purging variation within them. The population structure is incompatible with traditional ‘polyphasic taxonomy′ that requires bacterial species to have both phylogenetic coherence and distinctive phenotypes. More generally, genomics has revealed that many bacterial species share adaptive modules by horizontal gene transfer, and we envisage a more consistent taxonomic framework that explicitly recognizes this. Significant phenotypes should be recognized as ‘biovars' within species that are defined by core gene phylogeny.
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Affiliation(s)
- Nitin Kumar
- Department of Biology, University of York, York YO10 5DD, UK
| | - Ganesh Lad
- Department of Biology, University of York, York YO10 5DD, UK
| | - Elisa Giuntini
- Department of Biology, University of York, York YO10 5DD, UK
| | - Maria E Kaye
- Department of Biology, University of York, York YO10 5DD, UK
| | | | | | - J Peter W Young
- Department of Biology, University of York, York YO10 5DD, UK
| | - Xavier Bailly
- Department of Biology, University of York, York YO10 5DD, UK
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44
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Koton Y, Gordon M, Chalifa-Caspi V, Bisharat N. Comparative genomic analysis of clinical and environmental Vibrio vulnificus isolates revealed biotype 3 evolutionary relationships. Front Microbiol 2015; 5:803. [PMID: 25642229 PMCID: PMC4295529 DOI: 10.3389/fmicb.2014.00803] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2014] [Accepted: 12/29/2014] [Indexed: 12/19/2022] Open
Abstract
In 1996 a common-source outbreak of severe soft tissue and bloodstream infections erupted among Israeli fish farmers and fish consumers due to changes in fish marketing policies. The causative pathogen was a new strain of Vibrio vulnificus, named biotype 3, which displayed a unique biochemical and genotypic profile. Initial observations suggested that the pathogen erupted as a result of genetic recombination between two distinct populations. We applied a whole genome shotgun sequencing approach using several V. vulnificus strains from Israel in order to study the pan genome of V. vulnificus and determine the phylogenetic relationship of biotype 3 with existing populations. The core genome of V. vulnificus based on 16 draft and complete genomes consisted of 3068 genes, representing between 59 and 78% of the whole genome of 16 strains. The accessory genome varied in size from 781 to 2044 kbp. Phylogenetic analysis based on whole, core, and accessory genomes displayed similar clustering patterns with two main clusters, clinical (C) and environmental (E), all biotype 3 strains formed a distinct group within the E cluster. Annotation of accessory genomic regions found in biotype 3 strains and absent from the core genome yielded 1732 genes, of which the vast majority encoded hypothetical proteins, phage-related proteins, and mobile element proteins. A total of 1916 proteins (including 713 hypothetical proteins) were present in all human pathogenic strains (both biotype 3 and non-biotype 3) and absent from the environmental strains. Clustering analysis of the non-hypothetical proteins revealed 148 protein clusters shared by all human pathogenic strains; these included transcriptional regulators, arylsulfatases, methyl-accepting chemotaxis proteins, acetyltransferases, GGDEF family proteins, transposases, type IV secretory system (T4SS) proteins, and integrases. Our study showed that V. vulnificus biotype 3 evolved from environmental populations and formed a genetically distinct group within the E-cluster. The unique epidemiological circumstances facilitated disease outbreak and brought this genotype to the attention of the scientific community.
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Affiliation(s)
- Yael Koton
- Department of Medicine D, Emek Medical Center Afula, Israel ; Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology Haifa, Israel
| | - Michal Gordon
- Bioinformatics Core Facility, National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev Beer-Sheva, Israel
| | - Vered Chalifa-Caspi
- Bioinformatics Core Facility, National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev Beer-Sheva, Israel
| | - Naiel Bisharat
- Department of Medicine D, Emek Medical Center Afula, Israel ; Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology Haifa, Israel
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45
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Segerman B. The genetic integrity of bacterial species: the core genome and the accessory genome, two different stories. Front Cell Infect Microbiol 2012; 2:116. [PMID: 22973561 PMCID: PMC3434323 DOI: 10.3389/fcimb.2012.00116] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Accepted: 08/20/2012] [Indexed: 11/13/2022] Open
Abstract
Strains within a bacterial species typically have a set of conserved core genes and a variable set of accessory genes. The accessory genes often appear to move laterally between strains, thereby forming new trait combinations. Sometimes, genetic material also moves laterally between species, thereby resulting in diffuse borders between them. The growing number of genome sequences offers new possibilities to study these processes. Ten species for which abundant genomic data exists were here selected for analysis of the species border integrity. The average core genome similarities and relative core genome sizes (RCGSs) were determined for strain pairs within the species and for strain pairs crossing the species border. The variability within the species as well as the border integrity varies for different bacterial species. Some have very distinct borders while others are more or less indefinable. From the growing amount of genomic data, it becomes even clearer that the concept of bacterial species is, in many cases, far from absolute.
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Affiliation(s)
- Bo Segerman
- National Veterinary Institute Uppsala, Sweden.
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46
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Klockgether J, Cramer N, Wiehlmann L, Davenport CF, Tümmler B. Pseudomonas aeruginosa Genomic Structure and Diversity. Front Microbiol 2011; 2:150. [PMID: 21808635 PMCID: PMC3139241 DOI: 10.3389/fmicb.2011.00150] [Citation(s) in RCA: 197] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Accepted: 06/27/2011] [Indexed: 12/23/2022] Open
Abstract
The Pseudomonas aeruginosa genome (G + C content 65–67%, size 5.5–7 Mbp) is made up of a single circular chromosome and a variable number of plasmids. Sequencing of complete genomes or blocks of the accessory genome has revealed that the genome encodes a large repertoire of transporters, transcriptional regulators, and two-component regulatory systems which reflects its metabolic diversity to utilize a broad range of nutrients. The conserved core component of the genome is largely collinear among P. aeruginosa strains and exhibits an interclonal sequence diversity of 0.5–0.7%. Only a few loci of the core genome are subject to diversifying selection. Genome diversity is mainly caused by accessory DNA elements located in 79 regions of genome plasticity that are scattered around the genome and show an anomalous usage of mono- to tetradecanucleotides. Genomic islands of the pKLC102/PAGI-2 family that integrate into tRNALys or tRNAGly genes represent hotspots of inter- and intraclonal genomic diversity. The individual islands differ in their repertoire of metabolic genes that make a large contribution to the pangenome. In order to unravel intraclonal diversity of P. aeruginosa, the genomes of two members of the PA14 clonal complex from diverse habitats and geographic origin were compared. The genome sequences differed by less than 0.01% from each other. One hundred ninety-eight of the 231 single nucleotide substitutions (SNPs) were non-randomly distributed in the genome. Non-synonymous SNPs were mainly found in an integrated Pf1-like phage and in genes involved in transcriptional regulation, membrane and extracellular constituents, transport, and secretion. In summary, P. aeruginosa is endowed with a highly conserved core genome of low sequence diversity and a highly variable accessory genome that communicates with other pseudomonads and genera via horizontal gene transfer.
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Affiliation(s)
- Jens Klockgether
- Klinik für Pädiatrische Pneumologie, Allergologie und Neonatologie, Klinische Forschergruppe Hannover, Germany
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