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Royer G, Clermont O, Marin J, Condamine B, Dion S, Blanquart F, Galardini M, Denamur E. Epistatic interactions between the high pathogenicity island and other iron uptake systems shape Escherichia coli extra-intestinal virulence. Nat Commun 2023; 14:3667. [PMID: 37339949 DOI: 10.1038/s41467-023-39428-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Accepted: 06/13/2023] [Indexed: 06/22/2023] Open
Abstract
The intrinsic virulence of extra-intestinal pathogenic Escherichia coli is associated with numerous chromosomal and/or plasmid-borne genes, encoding diverse functions such as adhesins, toxins, and iron capture systems. However, the respective contribution to virulence of those genes seems to depend on the genetic background and is poorly understood. Here, we analyze genomes of 232 strains of sequence type complex STc58 and show that virulence (quantified in a mouse model of sepsis) emerged in a sub-group of STc58 due to the presence of the siderophore-encoding high-pathogenicity island (HPI). When extending our genome-wide association study to 370 Escherichia strains, we show that full virulence is associated with the presence of the aer or sit operons, in addition to the HPI. The prevalence of these operons, their co-occurrence and their genomic location depend on strain phylogeny. Thus, selection of lineage-dependent specific associations of virulence-associated genes argues for strong epistatic interactions shaping the emergence of virulence in E. coli.
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Affiliation(s)
- Guilhem Royer
- Université Paris Cité, IAME, INSERM, Paris, France
- Département de Prévention, Diagnostic et Traitement des Infections, Hôpital Henri Mondor, Créteil, France
- LABGeM, Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Université Paris-Saclay, Evry, France
- EERA Unit "Ecology and Evolution of Antibiotics Resistance," Institut Pasteur-Assistance Publique/Hôpitaux de Paris-Université Paris-Saclay, Paris, France
- UMR CNRS, 3525, Paris, France
| | | | - Julie Marin
- Université Paris Cité, IAME, INSERM, Paris, France
- Université Sorbonne Paris Nord, IAME, INSERM, Bobigny, France
| | | | - Sara Dion
- Université Paris Cité, IAME, INSERM, Paris, France
| | - François Blanquart
- Center for Interdisciplinary Research in Biology, CNRS, Collège de France, PSL Research University, Paris, France
| | - Marco Galardini
- Institute for Molecular Bacteriology, TWINCORE Centre for Experimental and Clinical Infection Research, a joint venture between the Hannover Medical School (MHH) and the Helmholtz Centre for Infection Research (HZI), Hannover, Germany
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School (MHH), Hannover, Germany
| | - Erick Denamur
- Université Paris Cité, IAME, INSERM, Paris, France.
- AP-HP, Hôpital Bichat, Laboratoire de Génétique Moléculaire, Paris, France.
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2
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Denamur E, Condamine B, Esposito-Farèse M, Royer G, Clermont O, Laouenan C, Lefort A, de Lastours V, Galardini M. Genome wide association study of Escherichia coli bloodstream infection isolates identifies genetic determinants for the portal of entry but not fatal outcome. PLoS Genet 2022; 18:e1010112. [PMID: 35324915 PMCID: PMC8946752 DOI: 10.1371/journal.pgen.1010112] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Accepted: 02/21/2022] [Indexed: 11/19/2022] Open
Abstract
Escherichia coli is an important cause of bloodstream infections (BSI), which is of concern given its high mortality and increasing worldwide prevalence. Finding bacterial genetic variants that might contribute to patient death is of interest to better understand infection progression and implement diagnostic methods that specifically look for those factors. E. coli samples isolated from patients with BSI are an ideal dataset to systematically search for those variants, as long as the influence of host factors such as comorbidities are taken into account. Here we performed a genome-wide association study (GWAS) using data from 912 patients with E. coli BSI from hospitals in Paris, France. We looked for associations between bacterial genetic variants and three patient outcomes (death at 28 days, septic shock and admission to intensive care unit), as well as two portals of entry (urinary and digestive tract), using various clinical variables from each patient to account for host factors. We did not find any association between genetic variants and patient outcomes, potentially confirming the strong influence of host factors in influencing the course of BSI; we however found a strong association between the papGII operon and entrance of E. coli through the urinary tract, which demonstrates the power of bacterial GWAS when applied to actual clinical data. Despite the lack of associations between E. coli genetic variants and patient outcomes, we estimate that increasing the sample size by one order of magnitude could lead to the discovery of some putative causal variants. Given the wide adoption of bacterial genome sequencing of clinical isolates, such sample sizes may be soon available.
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Affiliation(s)
- Erick Denamur
- Université de Paris, IAME, UMR 1137, INSERM, Paris, France
- Laboratoire de Génétique Moléculaire, Hôpital Bichat, AP-HP, Paris, France
| | | | - Marina Esposito-Farèse
- Département d’épidémiologie, biostatistiques et recherche clinique, Hôpital Bichat, AP-HP, Paris, France
| | - Guilhem Royer
- Université de Paris, IAME, UMR 1137, INSERM, Paris, France
- LABGeM, Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Université Paris-Saclay, Evry, France
- Département de Prévention, Diagnostic et Traitement des Infections, Hôpital Henri Mondor, Créteil, France
| | | | - Cédric Laouenan
- Université de Paris, IAME, UMR 1137, INSERM, Paris, France
- Département d’épidémiologie, biostatistiques et recherche clinique, Hôpital Bichat, AP-HP, Paris, France
| | - Agnès Lefort
- Université de Paris, IAME, UMR 1137, INSERM, Paris, France
- Service de Médecine Interne, Hôpital Beaujon, AP-HP, Clichy, France
| | - Victoire de Lastours
- Université de Paris, IAME, UMR 1137, INSERM, Paris, France
- Service de Médecine Interne, Hôpital Beaujon, AP-HP, Clichy, France
| | - Marco Galardini
- Institute for Molecular Bacteriology, TWINCORE Centre for Experimental and Clinical Infection Research, a joint venture between the Hannover Medical School (MHH) and the Helmholtz Centre for Infection Research (HZI), Hannover, Germany
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School (MHH), Hannover, Germany
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3
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Persistence of Antibiotic-Resistant Escherichia coli Strains Belonging to the B2 Phylogroup in Municipal Wastewater under Aerobic Conditions. Antibiotics (Basel) 2022; 11:antibiotics11020202. [PMID: 35203805 PMCID: PMC8868233 DOI: 10.3390/antibiotics11020202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 01/24/2022] [Accepted: 02/02/2022] [Indexed: 02/05/2023] Open
Abstract
Escherichia coli is classified into four major phylogenetic groups (A, B1, B2, and D) that are associated with antibiotic resistance genes. Although antibiotic-resistant E. coli is commonly detected in municipal wastewater, little is known about the relationship between the phylogenetic groups and antibiotic-resistant E. coli in wastewater. In this study, the survival of E. coli in wastewater and the changes to the relationships between each phylogroup and the antibiotic-resistant profiles of E. coli isolates from wastewater were investigated under aerobic conditions for 14 days. The isolates were classified into the phylogroups A, B1, B2, and D or others by multiplex PCR. In addition, the susceptibility of the isolates to 11 antibiotics was assessed with the minimum inhibitory concentration (MIC) assay. While E. coli counts decreased in the wastewater with time under aerobic conditions, the prevalence of phylogroup B2 had increased to 73% on day 14. Furthermore, the MIC assay revealed that the abundance of antibiotic-resistant E. coli also increased on day 14. After batch-mixing the experiments under aerobic conditions, the surviving antibiotic-resistant E. coli included mainly multidrug-resistant and beta-lactamase-producing isolates belonging to phylogroup B2. These results suggest that the phylogroup B2 isolates that have acquired antibiotic resistance had a high survivability in the treated wastewater.
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4
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Clermont O, Condamine B, Dion S, Gordon DM, Denamur E. The E phylogroup of Escherichia coli is highly diverse and mimics the whole E. coli species population structure. Environ Microbiol 2021; 23:7139-7151. [PMID: 34431197 DOI: 10.1111/1462-2920.15742] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 08/16/2021] [Accepted: 08/22/2021] [Indexed: 12/11/2022]
Abstract
To get a global picture of the population structure of the Escherichia coli phylogroup E, encompassing the O157:H7 EHEC lineage, we analysed the whole genome of 144 strains isolated from various continents, hosts and lifestyles and representative of the phylogroup diversity. The strains possess 4331 to 5440 genes with a core genome of 2771 genes and a pangenome of 33 722 genes. The distribution of these genes among the strains shows an asymmetric U-shaped distribution. E phylogenetic strains have the largest genomes of the species, partly explained by the presence of mobile genetic elements. Sixty-eight lineages were delineated, some of them exhibiting extra-intestinal virulence genes and being virulent in the mouse sepsis model. Except for the EHEC lineages and the reference EPEC, EIEC and ETEC strains, very few strains possess intestinal virulence genes. Most of the strains were devoid of acquired resistance genes, but eight strains possessed extended-spectrum beta-lactamase genes. Human strains belong to specific lineages, some of them being virulent and antibiotic-resistant [sequence type complexes (STcs) 350 and 2064]. The E phylogroup mimics all the features of the species as a whole, a phenomenon already observed at the STc level, arguing for a fractal population structure of E. coli.
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Affiliation(s)
- Olivier Clermont
- Université de Paris, IAME, UMR 1137, INSERM, Paris, F-75018, France
| | | | - Sara Dion
- Université de Paris, IAME, UMR 1137, INSERM, Paris, F-75018, France
| | - David M Gordon
- Division of Ecology and Evolution, Research School of Biology, Australian National University, Canberra, ACT, Australia
| | - Erick Denamur
- Université de Paris, IAME, UMR 1137, INSERM, Paris, F-75018, France
- AP-HP, Laboratoire de Génétique Moléculaire, Hôpital Bichat-Claude Bernard, Paris, F-75018, France
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5
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Yu D, Banting G, Neumann NF. A review of the taxonomy, genetics, and biology of the genus Escherichia and the type species Escherichia coli. Can J Microbiol 2021; 67:553-571. [PMID: 33789061 DOI: 10.1139/cjm-2020-0508] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Historically, bacteriologists have relied heavily on biochemical and structural phenotypes for bacterial taxonomic classification. However, advances in comparative genomics have led to greater insights into the remarkable genetic diversity within the microbial world, and even within well-accepted species such as Escherichia coli. The extraordinary genetic diversity in E. coli recapitulates the evolutionary radiation of this species in exploiting a wide range of niches (i.e., ecotypes), including the gastrointestinal system of diverse vertebrate hosts as well as non-host natural environments (soil, natural waters, wastewater), which drives the adaptation, natural selection, and evolution of intragenotypic conspecific specialism as a strategy for survival. Over the last few years, there has been increasing evidence that many E. coli strains are very host (or niche)-specific. While biochemical and phylogenetic evidence support the classification of E. coli as a distinct species, the vast genomic (diverse pan-genome and intragenotypic variability), phenotypic (e.g., metabolic pathways), and ecotypic (host-/niche-specificity) diversity, comparable to the diversity observed in known species complexes, suggest that E. coli is better represented as a complex. Herein we review the taxonomic classification of the genus Escherichia and discuss how phenotype, genotype, and ecotype recapitulate our understanding of the biology of this remarkable bacterium.
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Affiliation(s)
- Daniel Yu
- School of Public Health, University of Alberta, Edmonton, AB T6G IC9, Canada.,School of Public Health, University of Alberta, Edmonton, AB T6G IC9, Canada
| | - Graham Banting
- School of Public Health, University of Alberta, Edmonton, AB T6G IC9, Canada.,School of Public Health, University of Alberta, Edmonton, AB T6G IC9, Canada
| | - Norman F Neumann
- School of Public Health, University of Alberta, Edmonton, AB T6G IC9, Canada.,School of Public Health, University of Alberta, Edmonton, AB T6G IC9, Canada
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6
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Abram K, Udaondo Z, Bleker C, Wanchai V, Wassenaar TM, Robeson MS, Ussery DW. Mash-based analyses of Escherichia coli genomes reveal 14 distinct phylogroups. Commun Biol 2021; 4:117. [PMID: 33500552 PMCID: PMC7838162 DOI: 10.1038/s42003-020-01626-5] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 12/21/2020] [Indexed: 01/30/2023] Open
Abstract
In this study, more than one hundred thousand Escherichia coli and Shigella genomes were examined and classified. This is, to our knowledge, the largest E. coli genome dataset analyzed to date. A Mash-based analysis of a cleaned set of 10,667 E. coli genomes from GenBank revealed 14 distinct phylogroups. A representative genome or medoid identified for each phylogroup was used as a proxy to classify 95,525 unassembled genomes from the Sequence Read Archive (SRA). We find that most of the sequenced E. coli genomes belong to four phylogroups (A, C, B1 and E2(O157)). Authenticity of the 14 phylogroups is supported by several different lines of evidence: phylogroup-specific core genes, a phylogenetic tree constructed with 2613 single copy core genes, and differences in the rates of gene gain/loss/duplication. The methodology used in this work is able to reproduce known phylogroups, as well as to identify previously uncharacterized phylogroups in E. coli species.
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Affiliation(s)
- Kaleb Abram
- Department of Biomedical Informatics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, 72205, USA
| | - Zulema Udaondo
- Department of Biomedical Informatics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, 72205, USA
| | - Carissa Bleker
- The Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee, Knoxville, Tennessee, 37996, USA
- Department of Electrical Engineering and Computer Science, University of Tennessee, Knoxville, Tennessee, 37996, USA
| | - Visanu Wanchai
- Department of Biomedical Informatics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, 72205, USA
| | - Trudy M Wassenaar
- Molecular Microbiology and Genomics Consultants, 55576, Zotzenheim, Germany
| | - Michael S Robeson
- Department of Biomedical Informatics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, 72205, USA
| | - David W Ussery
- Department of Biomedical Informatics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, 72205, USA.
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7
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Abstract
Escherichia coli is a commensal of the vertebrate gut that is increasingly involved in various intestinal and extra-intestinal infections as an opportunistic pathogen. Numerous pathotypes that represent groups of strains with specific pathogenic characteristics have been described based on heterogeneous and complex criteria. The democratization of whole-genome sequencing has led to an accumulation of genomic data that render possible a population phylogenomic approach to the emergence of virulence. Few lineages are responsible for the pathologies compared with the diversity of commensal strains. These lineages emerged multiple times during E. coli evolution, mainly by acquiring virulence genes located on mobile elements, but in a specific chromosomal phylogenetic background. This repeated emergence of stable and cosmopolitan lineages argues for an optimization of strain fitness through epistatic interactions between the virulence determinants and the remaining genome.
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8
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Clermont O, Dixit OVA, Vangchhia B, Condamine B, Dion S, Bridier-Nahmias A, Denamur E, Gordon D. Characterization and rapid identification of phylogroup G in Escherichia coli, a lineage with high virulence and antibiotic resistance potential. Environ Microbiol 2019; 21:3107-3117. [PMID: 31188527 DOI: 10.1111/1462-2920.14713] [Citation(s) in RCA: 132] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 05/31/2019] [Accepted: 06/09/2019] [Indexed: 12/22/2022]
Abstract
The phylogeny of the Escherichia coli species, with the identification of seven phylogroups (A, B1, B2, C, D, E and F), is linked to the lifestyle of the strains. With the accumulation of whole genome sequence data, it became clear that some strains belong to a group intermediate between the F and B2 phylogroups, designated as phylogroup G. Here, we studied the complete sequences of 112 strains representative of the G phylogroup diversity and showed that it is composed of one main sequence type complex (STc)117 and four other STcs (STc657, STc454, STc738 and STc174). STc117, which phylogeny is characterized by very short internal branches, exhibits extensive O diversity, but little H-type and fimH allele diversity, whereas the other STcs are characterized by a main O, H and fimH type. STc117 strains possess many traits associated with extra-intestinal virulence, are virulent in a mouse sepsis model and exhibit multi-drug resistance such as CTX-M production. Epidemiologic data on 4,524 Australian and French strains suggest that STc117 is a poultry-associated lineage that can also establish in humans and cause extra-intestinal diseases. We propose an easy identification method that will help to trace this potentially virulent and resistant phylogroup in epidemiologic studies.
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Affiliation(s)
- Olivier Clermont
- IAME, UMR 1137, INSERM, Université de Paris, Paris, 75018, France
| | - Ojas V A Dixit
- Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Belinda Vangchhia
- Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia.,Department of Veterinary Microbiology, College of Veterinary Sciences & Animal Husbandry, Central Agricultural University, Aizawl, 796014, India
| | | | - Sara Dion
- IAME, UMR 1137, INSERM, Université de Paris, Paris, 75018, France
| | | | - Erick Denamur
- IAME, UMR 1137, INSERM, Université de Paris, Paris, 75018, France.,Laboratoire de Génétique Moléculaire, Hôpital Bichat, Paris, 75018, France
| | - David Gordon
- Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
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Desroches M, Clermont O, Lafeuillade B, Rodriguez C, Darty M, Royer G, Bouvet O, Ounnoughene N, Noizat-Pirenne F, Denamur E, Decousser JW. Genotypic and phenotypic characteristics of Escherichia coli involved in transfusion-transmitted bacterial infections: implications for preventive strategies. Transfusion 2019; 58:1940-1950. [PMID: 30198609 DOI: 10.1111/trf.14812] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 03/05/2018] [Accepted: 04/09/2018] [Indexed: 01/23/2023]
Abstract
BACKGROUND Transfusion-transmitted bacterial infections (TTBIs) are the main residual infectious complications of transfusions. Escherichia coli and platelet (PLT) concentrates may be epidemiologically associated, leading to severe, if not lethal, TTBIs. We investigated the genotypic and phenotypic reasons for this clinically deleterious combination. STUDY DESIGN AND METHODS We investigated a French national E. coli strain collection related to six independent episodes of TTBIs. Their phenotypic characterizations included antibiotic susceptibility testing, growth testing under different culture conditions, serum survival assays, and virulence in a sepsis mouse model. Their genotypic characterizations included polymerase chain reaction phylotyping, whole genome sequencing, and a subsequent in silico analysis. RESULTS We highlighted a selection process of highly extraintestinal virulent strains, mainly belonging to the B2 phylogroup, adapted to the hostile environment (high citrate concentration and a bactericidal serum effect) of apheresis-collected platelet concentrates (PCs). Compared to controls, the E. coli TTBI strains grew faster in the PCs due to a superior ability to capture iron. The in vitro growth performances were highly compatible with blood-derived product real-life conditions, including storage conditions and delays. The consistent serum resistance of TTBI strains promotes their survival in both the donor's and the receiver's blood and in the PCs. CONCLUSION This study pointed out that E. coli strains responsible for TTBI exhibit very specific traits. They belong to the extraintestinal pathogenic phylogroups and have a high intrinsic virulence. They can be resistant to complement, capture iron, and grow in the apheresis-collected PCs. These findings therefore support the reinforcement of the postdonation information.
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Affiliation(s)
- Marine Desroches
- INSERM UMR1137, IAME, Paris Diderot University, Faculty of Medicine Xavier Bichat, Paris, France.,Department of Bacteriology and Infection Control, University Hospital Henri Mondor, Assistance Publique-Hôpitaux de Paris, Créteil, France
| | - Olivier Clermont
- INSERM UMR1137, IAME, Paris Diderot University, Faculty of Medicine Xavier Bichat, Paris, France
| | - Bruno Lafeuillade
- Rhône-Alpes French Blood Establishment-Grenoble Site, La Tronche, France
| | - Christophe Rodriguez
- Next Generation Sequencing Platform, University Hospital Henri Mondor, Créteil, France
| | - Mélanie Darty
- Next Generation Sequencing Platform, University Hospital Henri Mondor, Créteil, France
| | - Guilhem Royer
- INSERM UMR1137, IAME, Paris Diderot University, Faculty of Medicine Xavier Bichat, Paris, France.,Department of Bacteriology and Infection Control, University Hospital Henri Mondor, Assistance Publique-Hôpitaux de Paris, Créteil, France
| | - Odile Bouvet
- INSERM UMR1137, IAME, Paris Diderot University, Faculty of Medicine Xavier Bichat, Paris, France
| | | | | | - Erick Denamur
- INSERM UMR1137, IAME, Paris Diderot University, Faculty of Medicine Xavier Bichat, Paris, France.,Department of Molecular Genetics, University Hospital Bichat, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Jean-Winoc Decousser
- INSERM UMR1137, IAME, Paris Diderot University, Faculty of Medicine Xavier Bichat, Paris, France.,Department of Bacteriology and Infection Control, University Hospital Henri Mondor, Assistance Publique-Hôpitaux de Paris, Créteil, France
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10
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Chen L, Wang L, Yassin AK, Zhang J, Gong J, Qi K, Ganta RR, Zhang Y, Yang Y, Han X, Wang C. Genetic characterization of extraintestinal Escherichia coli isolates from chicken, cow and swine. AMB Express 2018; 8:117. [PMID: 30019301 PMCID: PMC6049849 DOI: 10.1186/s13568-018-0646-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 07/10/2018] [Indexed: 02/07/2023] Open
Abstract
Phenotypic determination of antimicrobial resistance in bacteria is very important for diagnosis and treatment, but sometimes this procedure needs further genetic evaluation. Whole-genome sequencing plays a critical role in deciphering and advancing our understanding of bacterial evolution, transmission, and surveillance of antimicrobial resistance. In this study, whole-genome sequencing was performed on nineteen clinically extraintestinal Escherichia coli isolates from chicken, cows and swine and showing different antimicrobial susceptibility. A total of 44 different genes conferring resistance to 11 classes of antimicrobials were detected in 15 of 19 E. coli isolates (78.9%), and 22 types of plasmids were detected in 15/19 (78.9%) isolates. In addition, whole-genome sequencing of these 19 isolates identified 111 potential virulence factors, and 53 of these VFDB-annotated genes were carried by all these 19 isolates. Twelve different virulence genes were identified while the most frequent ones were gad (glutamate decarboxylase), iss (increased serum survival) and lpfA (long polar fimbriae). All isolates harbored at least one of the virulence genes. The findings from comparative genomic analyses of the 19 diverse E. coli isolates in this study provided insights into molecular basis of the rising multi-drug resistance in E. coli.
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Affiliation(s)
- Li Chen
- grid.268415.cCollege of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu 225009 China
| | - Leyi Wang
- 0000 0004 1936 9991grid.35403.31Department of Veterinary Clinical Medicine and the Veterinary Diagnostic Laboratory, College of Veterinary Medicine, University of Illinois, Urbana, IL 61802 USA
| | - Afrah Kamal Yassin
- grid.268415.cCollege of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu 225009 China
- 0000 0001 0674 6207grid.9763.bDepartment of Food Hygiene and Safety, Faculty of Public and Environmental Health, University of Khartoum, Khartoum, 11115 Sudan
| | - Jilei Zhang
- grid.268415.cCollege of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu 225009 China
| | - Jiansen Gong
- 0000 0001 0526 1937grid.410727.7Poultry Institute, Chinese Academy of Agricultural Sciences, Yangzhou, Jiangsu 225009 China
| | - Kezong Qi
- 0000 0004 1760 4804grid.411389.6Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, Anhui Agricultural University, Hefei, 230036 China
| | - Roman R. Ganta
- 0000 0001 0737 1259grid.36567.31Center of Excellence for Vector-Borne Diseases (CEVBD), Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506 USA
| | - Yuanyuan Zhang
- grid.268415.cCollege of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu 225009 China
| | - Yi Yang
- grid.268415.cCollege of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu 225009 China
| | - Xiangan Han
- 0000 0001 0526 1937grid.410727.7Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Chengming Wang
- 0000 0001 2297 8753grid.252546.2College of Veterinary Medicine, Auburn University, Auburn, AL USA
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11
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Stoppe NDC, Silva JS, Carlos C, Sato MIZ, Saraiva AM, Ottoboni LMM, Torres TT. Worldwide Phylogenetic Group Patterns of Escherichia coli from Commensal Human and Wastewater Treatment Plant Isolates. Front Microbiol 2017; 8:2512. [PMID: 29312213 PMCID: PMC5742620 DOI: 10.3389/fmicb.2017.02512] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2017] [Accepted: 12/04/2017] [Indexed: 01/01/2023] Open
Abstract
Escherichia coli is an important microorganism in the gastrointestinal tract of warm-blooded animals. Commensal populations of E. coli consist of stable genetic isolates, which means that each individual has only one phylogenetic group (phylogroup). We evaluated the frequency of human commensal E. coli phylogroups from 116 people and observed that the majority of isolates belonged to group A. We also evaluated the frequency of phylogroups in wastewater samples and found a strong positive correlation between the phylogroup distribution in wastewater and human hosts. In order to find out if some factors, such as geographical location, and climate could influence the worldwide phylogroup distribution, we performed a meta-analysis of 39 different studies and 24 countries, including different climates, living areas, and feeding habits. Unexpectedly, our results showed no substructuring patterns of phylogroups; indicating there was no correlation between phylogroup distribution and geographic location, climate, living area, feeding habits, or date of collection.
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Affiliation(s)
- Nancy de Castro Stoppe
- Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas, Campinas, Brazil.,Núcleo de Pesquisa em Biodiversidade e Computação (BioComp-USP)-Universidade de São Paulo, São Paulo, Brazil
| | - Juliana S Silva
- Núcleo de Pesquisa em Biodiversidade e Computação (BioComp-USP)-Universidade de São Paulo, São Paulo, Brazil.,Secretaria de Estado de Saúde de Mato Grosso, Cuiabá, Brazil.,Departamento de Genética e Biologia Evolutiva, Universidade de São Paulo, São Paulo, Brazil
| | - Camila Carlos
- Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas, Campinas, Brazil
| | - Maria I Z Sato
- Departamento de Análises Ambientais, Companhia Ambiental do Estado de São Paulo-CETESB, São Paulo, Brazil
| | - Antonio M Saraiva
- Núcleo de Pesquisa em Biodiversidade e Computação (BioComp-USP)-Universidade de São Paulo, São Paulo, Brazil.,Departamento de Engenharia de Computação e Sistemas Digitais, Escola Politécnica da USP, São Paulo, Brazil
| | - Laura M M Ottoboni
- Centro de Biologia Molecular e Engenharia Genética, Universidade Estadual de Campinas, Campinas, Brazil
| | - Tatiana T Torres
- Núcleo de Pesquisa em Biodiversidade e Computação (BioComp-USP)-Universidade de São Paulo, São Paulo, Brazil.,Departamento de Genética e Biologia Evolutiva, Universidade de São Paulo, São Paulo, Brazil
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12
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Bouvet O, Bourdelier E, Glodt J, Clermont O, Denamur E. Diversity of the auxotrophic requirements in natural isolates of Escherichia coli. MICROBIOLOGY-SGM 2017; 163:891-899. [PMID: 28651684 DOI: 10.1099/mic.0.000482] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Isolates of Escherichia coli, except Shigella, are generally prototrophic; they do not require any growth factors to grow in mineral medium. However, a nicotinic acid requirement is common among B2 phylogroup STc95 O18 E. coli clone strains. Nicotinic acid is a precursor of nicotinamide adenine dinucleotide (NAD), an essential molecule that plays central role in cellular metabolism. The defect in NAD synthesis of these strains is due to alterations in de novo biosynthesis pathway nadB gene. Here, by studying growth on minimal medium with glycolytic (glucose) or gluconeogenic (pyruvate or succinate) substrates as the carbon supply in a large panel of E. coli natural isolates representative of the species diversity, we identify an absolute nicotinic acid requirement in non-STc95 strains due in one case to a nadA inactivation. The growth on glucose medium of some extraintestinal pathogenic E. coli strains belonging to various non-O18 B2 phylogroup STc95 clones is restored either by aspartate or nicotinate, demonstrating that the nicotinic acid requirement can also be due to an intracellular aspartate depletion. The auxotrophic requirements depend on the carbon source available in the environment. Moreover, some strains prototrophic in glucose medium become auxotrophic in succinate medium, and conversely, some strainsauxotrophic in glucose medium become prototrophic in succinate medium. Finally, a partial depletion of intracellular aspartate can be observed in some prototrophic strains belonging to various phylogroups. The observed more or less significant depletion according to isolates may be due to differences in tricarboxylic acid cycle enzyme activities. These metabolic defects could be involved in the adaptation of E. coli to its various niches.
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Affiliation(s)
- Odile Bouvet
- IAME, UMR 1137, INSERM, Univ Paris Diderot, Sorbonne Paris Cité, F-75018, Paris, France
| | - Emmanuelle Bourdelier
- IAME, UMR 1137, INSERM, Univ Paris Diderot, Sorbonne Paris Cité, F-75018, Paris, France
| | - Jeremy Glodt
- IAME, UMR 1137, INSERM, Univ Paris Diderot, Sorbonne Paris Cité, F-75018, Paris, France
| | - Olivier Clermont
- IAME, UMR 1137, INSERM, Univ Paris Diderot, Sorbonne Paris Cité, F-75018, Paris, France
| | - Erick Denamur
- AP-HP, Laboratoire de Génétique Moléculaire, Hôpital Bichat, F-75018, Paris, France.,IAME, UMR 1137, INSERM, Univ Paris Diderot, Sorbonne Paris Cité, F-75018, Paris, France
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13
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Abstract
Bacteria respond to cell density by expressing genes whose products are beneficial to the population as a whole. This response is brought about through the release into the medium of signaling molecules of the class N-acyl homoserine lactones, the concentration of which determines the level of gene expression. This form of communication between cells has been termed "quorum sensing," and has been found to operate in the control of many functions in a variety of gram-negative bacteria. As with all signaling between individuals, if fitness costs are associated with the release of and response to the signal, the inclusive fitness of alleles responsible for the phenomenon depends upon genetic relatedness between signaler and responder. The situation is considered in explicit models for bacterial population genetics, in which the critical parameter determining the success of quorum sensing is the mean number of cells founding a population sharing a patch of resource. It is found that extensive polymorphism for the presence or absence of quorum sensing is expected for a wide range of parameter space. If local communities of bacteria contain diverse species, community stability may be the consequence of these interactions rather than polymorphism.
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Affiliation(s)
- J F Y Brookfield
- Department of Genetics, University of Nottingham, Queens Medical Centre, Nottingham, NG7 2UH, United Kingdom
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14
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Abstract
The emergence of genomics over the last 10 years has provided new insights into the evolution and virulence of extraintestinal Escherichia coli. By combining population genetics and phylogenetic approaches to analyze whole-genome sequences, it became possible to link genomic features to specific phenotypes, such as the ability to cause urinary tract infections. An E. coli chromosome can vary extensively in length, ranging from 4.3 to 6.2 Mb, encoding 4,084 to 6,453 proteins. This huge diversity is structured as a set of less than 2,000 genes (core genome) that are conserved between all the strains and a set of variable genes. Based on the core genome, the history of the species can be reliably reconstructed, revealing the recent emergence of phylogenetic groups A and B1 and the more ancient groups B2, F, and D. Urovirulence is most often observed in B2/F/D group strains and is a multigenic process involving numerous combinations of genes and specific alleles with epistatic interactions, all leading down multiple evolutionary paths. The genes involved mainly code for adhesins, toxins, iron capture systems, and protectins, as well as metabolic pathways and mutation-rate-control systems. However, the barrier between commensal and uropathogenic E. coli strains is difficult to draw as the factors that are responsible for virulence have probably also been selected to allow survival of E. coli as a commensal in the intestinal tract. Genomic studies have also demonstrated that infections are not the result of a unique and stable isolate, but rather often involve several isolates with variable levels of diversity that dynamically changes over time.
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15
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Strain-specific impact of the high-pathogenicity island on virulence in extra-intestinal pathogenic Escherichia coli. Int J Med Microbiol 2016; 307:44-56. [PMID: 27923724 DOI: 10.1016/j.ijmm.2016.11.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 11/16/2016] [Accepted: 11/20/2016] [Indexed: 02/04/2023] Open
Abstract
In order to clarify the role of the high-pathogenicity island (HPI) in the experimental virulence of Escherichia coli, we constructed different deletion mutants of the entire HPI and of three individual genes (irp2, fyuA and ybtA), encoding for three main functions within the HPI. Those mutants were constructed for three phylogroup B2 strains (536-STc127, CFT073-STc73, and NU14-STc95), representative of the main B2 subgroups causing extra-intestinal infections. Transcriptional profiles obtained for the selected HPI genes irp2, fyuA and ybtA revealed similar patterns for all strains, both under selective iron-deplete conditions and in intracellular bacterial communities in vitro, with a high expression of irp2. Deletion of irp2 and ybtA abrogated yersiniabactin production, whereas the fyuA knockout was only slightly impaired for siderophore synthesis. The experimental virulence of the strains was then tested in amoeba Dictyostelium discoideum and mouse septicaemia models. No effect of any HPI mutant was observed for the two more virulent strains 536 and CFT073. In contrast, the virulence of the less virulent NU14 strain was dramatically diminished by the complete deletion of the HPI and irp2 gene whereas a lesser reduction in virulence was observed for the fyuA and ybtA deletion mutants. The two experimental virulence models gave similar results. It appears that the role of the HPI in experimental virulence is depending on the genetic background of the strains despite similar inter-strain transcriptional patterns of HPI genes, as well as of the functional class of the studied gene. Altogether, these data indicate that the intrinsic extra-intestinal virulence in the E. coli species is multigenic, with epistatic interactions between the genes.
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16
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Restriction Profiling of 23S Microheterogenic Ribosomal Repeats for Detection and Characterizing of E. coli and Their Clonal, Pathogenic, and Phylogroups. J Pathog 2016; 2015:562136. [PMID: 26885397 PMCID: PMC4738725 DOI: 10.1155/2015/562136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Revised: 10/31/2015] [Accepted: 11/02/2015] [Indexed: 11/17/2022] Open
Abstract
Correlating ribosomal microheterogenicity with unique restriction profiles can prove to be an efficacious and cost-effective approach compared with sequencing for microbial identification. An attempt to peruse restriction profiling of 23S ribosomal assemblage was ventured; digestion patterns with Bfa I discriminated E. coli from its colony morphovars, while Hae III profiles assisted in establishing distinct clonal groups. Among the gene pool of 399 ribosomal sequences extrapolated from 57 E. coli genomes, varying degree of predominance (I > III > IV > II) of Hae III pattern was observed. This was also corroborated in samples collected from clinical, commensal, and environmental origin. K-12 and its descendants showed type I pattern whereas E. coli-B and its descendants exhibited type IV, both of these patterns being exclusively present in E. coli. A near-possible association between phylogroups and Hae III profiles with presumable correlation between the clonal groups and different pathovars was established. The generic nature, conservation, and barcode gap of 23S rRNA gene make it an ideal choice and substitute to 16S rRNA gene, the most preferred region for molecular diagnostics in bacteria.
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17
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Massot M, Daubié AS, Clermont O, Jauréguy F, Couffignal C, Dahbi G, Mora A, Blanco J, Branger C, Mentré F, Eddi A, Picard B, Denamur E. Phylogenetic, virulence and antibiotic resistance characteristics of commensal strain populations of Escherichia coli from community subjects in the Paris area in 2010 and evolution over 30 years. MICROBIOLOGY-SGM 2016; 162:642-650. [PMID: 26822436 DOI: 10.1099/mic.0.000242] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
It is important to study commensal populations of Escherichia coli because they appear to be the reservoir of both extra-intestinal pathogenic E. coli and antibiotic resistant strains of E. coli. We studied 279 dominant faecal strains of E. coli from 243 adults living in the community in the Paris area in 2010. The phylogenetic group and subgroup [sequence type complex (STc)] of the isolates and the presence of 20 virulence genes were determined by PCR assays. The O-types and resistance to 18 antibiotics were assessed phenotypically. The B2 group was the most frequently recovered (34.0 %), followed by the A group (28.7 %), and other groups were more rare. The most prevalent B2 subgroups were II (STc73), IV (STc141), IX (STc95) and I (STc131), with 22.1, 21.1, 16.8 and 13.7 %, respectively, of the B2 group strains. Virulence factors (VFs) were more common in B2 group than other strains. One or more resistances were found in 125 strains (44.8 % of the collection) but only six (2.2 % of the collection) were multiresistant; no extended-spectrum beta-lactamase-producing strain was isolated. The C phylogroup and clonal group A strains were the most resistant. No trade-off between virulence and resistance was evidenced. We compared these strains with collections of strains gathered under the same conditions 30 and 10 years ago. There has been a parallel and linked increase in the frequency of B2 group strains (from 9.4 % in 1980, to 22.7 % in 2000 and 34.0 % in 2010) and of VFs. Antibiotic resistance also increased, from 22.6 % of strains resistant to at least one antibiotic in 1980, to 31.8 % in 2000 and 44.8 % in 2010; resistance to streptomycin, however, remained stable. Commensal human E. coli populations have clearly evolved substantially over time, presumably reflecting changes in human practices, and particularly increasing antibiotic use.
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Affiliation(s)
- Méril Massot
- INSERM, IAME, UMR1137, Paris, France
- Univ Paris Diderot, IAME, UMR1137, Sorbonne Paris Cité, Paris, France
| | - Anne-Sophie Daubié
- Univ Paris Nord, IAME, UMR1137, Sorbonne Paris Cité, Bobigny, France
- APHP, Hôpitaux Universitaires Paris Seine Saint-Denis, Site Avicenne, Bobigny, France
- INSERM, IAME, UMR1137, Paris, France
| | - Olivier Clermont
- INSERM, IAME, UMR1137, Paris, France
- Univ Paris Diderot, IAME, UMR1137, Sorbonne Paris Cité, Paris, France
| | - Françoise Jauréguy
- INSERM, IAME, UMR1137, Paris, France
- APHP, Hôpitaux Universitaires Paris Seine Saint-Denis, Site Avicenne, Bobigny, France
- Univ Paris Nord, IAME, UMR1137, Sorbonne Paris Cité, Bobigny, France
| | - Camille Couffignal
- INSERM, IAME, UMR1137, Paris, France
- Univ Paris Diderot, IAME, UMR1137, Sorbonne Paris Cité, Paris, France
| | - Ghizlane Dahbi
- Laboratorio de Referencia de E. coli (LREC), Departamento de Microbioloxía e Parasitoloxía, Facultade de Veterinaria, Universidade de Santiago de Compostela (USC), Lugo, Spain
| | - Azucena Mora
- Laboratorio de Referencia de E. coli (LREC), Departamento de Microbioloxía e Parasitoloxía, Facultade de Veterinaria, Universidade de Santiago de Compostela (USC), Lugo, Spain
| | - Jorge Blanco
- Laboratorio de Referencia de E. coli (LREC), Departamento de Microbioloxía e Parasitoloxía, Facultade de Veterinaria, Universidade de Santiago de Compostela (USC), Lugo, Spain
| | - Catherine Branger
- INSERM, IAME, UMR1137, Paris, France
- Univ Paris Diderot, IAME, UMR1137, Sorbonne Paris Cité, Paris, France
| | - France Mentré
- INSERM, IAME, UMR1137, Paris, France
- Univ Paris Diderot, IAME, UMR1137, Sorbonne Paris Cité, Paris, France
| | - Alain Eddi
- Département de Médecine Générale, Univ Paris Diderot, Sorbonne Paris Cité, Faculté de Médecine, Paris, France
| | - Bertrand Picard
- INSERM, IAME, UMR1137, Paris, France
- APHP, Hôpitaux Universitaires Paris Seine Saint-Denis, Site Avicenne, Bobigny, France
- Univ Paris Nord, IAME, UMR1137, Sorbonne Paris Cité, Bobigny, France
| | - Erick Denamur
- INSERM, IAME, UMR1137, Paris, France
- Univ Paris Diderot, IAME, UMR1137, Sorbonne Paris Cité, Paris, France
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18
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Skurnik D, Clermont O, Guillard T, Launay A, Danilchanka O, Pons S, Diancourt L, Lebreton F, Kadlec K, Roux D, Jiang D, Dion S, Aschard H, Denamur M, Cywes-Bentley C, Schwarz S, Tenaillon O, Andremont A, Picard B, Mekalanos J, Brisse S, Denamur E. Emergence of Antimicrobial-Resistant Escherichia coli of Animal Origin Spreading in Humans. Mol Biol Evol 2015; 33:898-914. [PMID: 26613786 DOI: 10.1093/molbev/msv280] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
In the context of the great concern about the impact of human activities on the environment, we studied 403 commensal Escherichia coli/Escherichia clade strains isolated from several animal and human populations that have variable contacts to one another. Multilocus sequence typing (MLST) showed a decrease of diversity 1) in strains isolated from animals that had an increasing contact with humans and 2) in all strains that had increased antimicrobial resistance. A specific B1 phylogroup clonal complex (CC87, Institut Pasteur schema nomenclature) of animal origin was identified and characterized as being responsible for the increased antimicrobial resistance prevalence observed in strains from the environments with a high human-mediated antimicrobial pressure. CC87 strains have a high capacity of acquiring and disseminating resistance genes with specific metabolic and genetic determinants as demonstrated by high-throughput sequencing and phenotyping. They are good mouse gut colonizers but are not virulent. Our data confirm the predominant role of human activities in the emergence of antimicrobial resistance in the environmental bacterial strains and unveil a particular E. coli clonal complex of animal origin capable of spreading antimicrobial resistance to other members of microbial communities.
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Affiliation(s)
- David Skurnik
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA INSERM, IAME, UMR 1137, Paris, France Univ Paris Diderot, IAME, Sorbonne Paris Cité, UMR 1137, Faculté De Médecine, Site Xavier Bichat, Paris, France French National Reference Center for Bacterial Resistance in Commensal Flora, Laboratory of Bacteriology, Bichat-Claude Bernard Hospital, Assistance Publique-Hôpitaux De Paris, Paris, France
| | - Olivier Clermont
- INSERM, IAME, UMR 1137, Paris, France Univ Paris Diderot, IAME, Sorbonne Paris Cité, UMR 1137, Faculté De Médecine, Site Xavier Bichat, Paris, France
| | - Thomas Guillard
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Adrien Launay
- INSERM, IAME, UMR 1137, Paris, France Univ Paris Diderot, IAME, Sorbonne Paris Cité, UMR 1137, Faculté De Médecine, Site Xavier Bichat, Paris, France
| | | | - Stéphanie Pons
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Laure Diancourt
- Institut Pasteur, Genotyping of Pathogens and Public Health, Paris, France
| | | | - Kristina Kadlec
- Institute of Farm Animal Genetics, Friedrich-Loeffler-Institut (FLI), Neustadt-Mariensee, Germany
| | - Damien Roux
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA INSERM, IAME, UMR 1137, Paris, France Univ Paris Diderot, IAME, Sorbonne Paris Cité, UMR 1137, Faculté De Médecine, Site Xavier Bichat, Paris, France
| | - Deming Jiang
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Sara Dion
- INSERM, IAME, UMR 1137, Paris, France Univ Paris Diderot, IAME, Sorbonne Paris Cité, UMR 1137, Faculté De Médecine, Site Xavier Bichat, Paris, France
| | | | - Maurice Denamur
- INSERM, IAME, UMR 1137, Paris, France Univ Paris Diderot, IAME, Sorbonne Paris Cité, UMR 1137, Faculté De Médecine, Site Xavier Bichat, Paris, France
| | - Colette Cywes-Bentley
- Division of Infectious Diseases, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Stefan Schwarz
- Institute of Farm Animal Genetics, Friedrich-Loeffler-Institut (FLI), Neustadt-Mariensee, Germany
| | - Olivier Tenaillon
- INSERM, IAME, UMR 1137, Paris, France Univ Paris Diderot, IAME, Sorbonne Paris Cité, UMR 1137, Faculté De Médecine, Site Xavier Bichat, Paris, France
| | - Antoine Andremont
- INSERM, IAME, UMR 1137, Paris, France Univ Paris Diderot, IAME, Sorbonne Paris Cité, UMR 1137, Faculté De Médecine, Site Xavier Bichat, Paris, France French National Reference Center for Bacterial Resistance in Commensal Flora, Laboratory of Bacteriology, Bichat-Claude Bernard Hospital, Assistance Publique-Hôpitaux De Paris, Paris, France
| | - Bertrand Picard
- INSERM, IAME, UMR 1137, Paris, France Univ Paris Nord, Sorbonne Paris Cité, UMR 1137, Faculté De Médecine, Site Xavier Bichat, Paris, France
| | | | - Sylvain Brisse
- Institut Pasteur, Genotyping of Pathogens and Public Health, Paris, France
| | - Erick Denamur
- INSERM, IAME, UMR 1137, Paris, France Univ Paris Diderot, IAME, Sorbonne Paris Cité, UMR 1137, Faculté De Médecine, Site Xavier Bichat, Paris, France
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19
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A peptide identification-free, genome sequence-independent shotgun proteomics workflow for strain-level bacterial differentiation. Sci Rep 2015; 5:14337. [PMID: 26395646 PMCID: PMC4585814 DOI: 10.1038/srep14337] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 08/25/2015] [Indexed: 11/16/2022] Open
Abstract
Shotgun proteomics is an emerging tool for bacterial identification and differentiation. However, the identification of the mass spectra of peptides to genome-derived peptide sequences remains a key issue that limits the use of shotgun proteomics to bacteria with genome sequences available. In this proof-of-concept study, we report a novel bacterial fingerprinting method that enjoys the resolving power and accuracy of mass spectrometry without the burden of peptide identification (i.e. genome sequence-independent). This method uses a similarity-clustering algorithm to search for mass spectra that are derived from the same peptide and merge them into a unique consensus spectrum as the basis to generate proteomic fingerprints of bacterial isolates. In comparison to a traditional peptide identification-based shotgun proteomics workflow and a PCR-based DNA fingerprinting method targeting the repetitive extragenic palindromes elements in bacterial genomes, the novel method generated fingerprints that were richer in information and more discriminative in differentiating E. coli isolates by their animal sources. The novel method is readily deployable to any cultivable bacteria, and may be used for several fields of study such as environmental microbiology, applied microbiology, and clinical microbiology.
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20
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Smati M, Clermont O, Bleibtreu A, Fourreau F, David A, Daubié AS, Hignard C, Loison O, Picard B, Denamur E. Quantitative analysis of commensal Escherichia coli populations reveals host-specific enterotypes at the intra-species level. Microbiologyopen 2015; 4:604-15. [PMID: 26033772 PMCID: PMC4554456 DOI: 10.1002/mbo3.266] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Revised: 04/14/2015] [Accepted: 04/17/2015] [Indexed: 12/26/2022] Open
Abstract
The primary habitat of the Escherichia coli species is the gut of warm-blooded vertebrates. The E. coli species is structured into four main phylogenetic groups A, B1, B2, and D. We estimated the relative proportions of these phylogroups in the feces of 137 wild and domesticated animals with various diets living in the Ile de France (Paris) region by real-time PCR. We distinguished three main clusters characterized by a particular abundance of two or more phylogroups within the E. coli animal commensal populations, which we called “enterocolitypes” by analogy with the enterotypes defined in the human gut microbiota at the genus level. These enterocolitypes were characterized by a dominant (>50%) B2, B1, or A phylogroup and were associated with different host species, diets, and habitats: wild and herbivorous species (wild rabbits and deer), domesticated herbivorous species (domesticated rabbits, horses, sheep, and cows), and omnivorous species (boar, pigs, and chickens), respectively. By analyzing retrospectively the data obtained using the same approach from 98 healthy humans living in Ile de France (Smati et al. 2013, Appl. Environ. Microbiol. 79, 5005–5012), we identified a specific human enterocolitype characterized by the dominant and/or exclusive (>90%) presence of phylogroup B2. We then compared B2 strains isolated from animals and humans, and revealed that human and animal strains differ regarding O-type and B2 subgroup. Moreover, two genes, sfa/foc and clbQ, were associated with the exclusive character of strains, observed only in humans. In conclusion, a complex network of interactions exists at several levels (genus and intra-species) within the intestinal microbiota.
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Affiliation(s)
- Mounira Smati
- INSERM, IAME, UMR 1137, F-75018, Paris, France.,Univ Paris Nord, IAME, UMR 1137, Sorbonne Paris Cité, Paris, France.,APHP, Hôpitaux Universitaires Paris Seine Saint-Denis, Hôpital Avicenne, Service de Bactériologie-Virologie-Hygiène, Bobigny, France
| | - Olivier Clermont
- INSERM, IAME, UMR 1137, F-75018, Paris, France.,Univ Paris Diderot, IAME, UMR 1137, Sorbonne Paris Cité, Paris, France
| | - Alexandre Bleibtreu
- INSERM, IAME, UMR 1137, F-75018, Paris, France.,Univ Paris Diderot, IAME, UMR 1137, Sorbonne Paris Cité, Paris, France
| | - Frédéric Fourreau
- APHP, Hôpitaux Universitaires Paris Seine Saint-Denis, Hôpital Avicenne, Service de Bactériologie-Virologie-Hygiène, Bobigny, France
| | - Anthony David
- INSERM, IAME, UMR 1137, F-75018, Paris, France.,Univ Paris Nord, IAME, UMR 1137, Sorbonne Paris Cité, Paris, France.,Univ Paris Diderot, IAME, UMR 1137, Sorbonne Paris Cité, Paris, France
| | - Anne-Sophie Daubié
- INSERM, IAME, UMR 1137, F-75018, Paris, France.,APHP, Hôpitaux Universitaires Paris Seine Saint-Denis, Hôpital Avicenne, Service de Bactériologie-Virologie-Hygiène, Bobigny, France.,Univ Paris Diderot, IAME, UMR 1137, Sorbonne Paris Cité, Paris, France
| | - Cécile Hignard
- Univ Paris Diderot, Station d'Ecologie Forestière, Sorbonne Paris Cité, Fontainebleau, France
| | - Odile Loison
- Univ Paris Diderot, Station d'Ecologie Forestière, Sorbonne Paris Cité, Fontainebleau, France
| | - Bertrand Picard
- INSERM, IAME, UMR 1137, F-75018, Paris, France.,Univ Paris Nord, IAME, UMR 1137, Sorbonne Paris Cité, Paris, France.,APHP, Hôpitaux Universitaires Paris Seine Saint-Denis, Hôpital Avicenne, Service de Bactériologie-Virologie-Hygiène, Bobigny, France
| | - Erick Denamur
- INSERM, IAME, UMR 1137, F-75018, Paris, France.,Univ Paris Diderot, IAME, UMR 1137, Sorbonne Paris Cité, Paris, France
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21
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Genome based phylogeny and comparative genomic analysis of intra-mammary pathogenic Escherichia coli. PLoS One 2015; 10:e0119799. [PMID: 25807497 PMCID: PMC4373696 DOI: 10.1371/journal.pone.0119799] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Accepted: 01/22/2015] [Indexed: 12/25/2022] Open
Abstract
Escherichia coli is an important cause of bovine mastitis and can cause both severe inflammation with a short-term transient infection, as well as less severe, but more chronic inflammation and infection persistence. E. coli is a highly diverse organism that has been classified into a number of different pathotypes or pathovars, and mammary pathogenic E. coli (MPEC) has been proposed as a new such pathotype. The purpose of this study was to use genome sequence data derived from both transient and persistent MPEC isolates (two isolates of each phenotype) to construct a genome-based phylogeny that places MPEC in its phylogenetic context with other E. coli pathovars. A subsidiary goal was to conduct comparative genomic analyses of these MPEC isolates with other E. coli pathovars to provide a preliminary perspective on loci that might be correlated with the MPEC phenotype. Both concatenated and consensus tree phylogenies did not support MPEC monophyly or the monophyly of either transient or persistent phenotypes. Three of the MPEC isolates (ECA-727, ECC-Z, and ECA-O157) originated from within the predominately commensal clade of E. coli, referred to as phylogroup A. The fourth MPEC isolate, of the persistent phenotype (ECC-1470), was sister group to an isolate of ETEC, falling within the E. coli B1 clade. This suggests that the MPEC phenotype has arisen on numerous independent occasions and that this has often, although not invariably, occurred from commensal ancestry. Examination of the genes present in the MPEC strains relative to the commensal strains identified a consistent presence of the type VI secretion system (T6SS) in the MPEC strains, with only occasional representation in commensal strains, suggesting that T6SS may be associated with MPEC pathogenesis and/or as an inter-bacterial competitive attribute and therefore could represent a useful target to explore for the development of MPEC specific inhibitors.
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22
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Development of an allele-specific PCR for Escherichia coli B2 sub-typing, a rapid and easy to perform substitute of multilocus sequence typing. J Microbiol Methods 2014; 101:24-7. [DOI: 10.1016/j.mimet.2014.03.008] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Revised: 03/19/2014] [Accepted: 03/20/2014] [Indexed: 11/19/2022]
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Evolutionary genomics of Borrelia burgdorferi sensu lato: findings, hypotheses, and the rise of hybrids. INFECTION GENETICS AND EVOLUTION 2014; 27:576-93. [PMID: 24704760 DOI: 10.1016/j.meegid.2014.03.025] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Revised: 03/23/2014] [Accepted: 03/24/2014] [Indexed: 01/14/2023]
Abstract
Borrelia burgdorferi sensu lato (B. burgdorferi s.l.), the group of bacterial species represented by Lyme disease pathogens, has one of the most complex and variable genomic architectures among prokaryotes. Showing frequent recombination within and limited gene flow among geographic populations, the B. burgdorferi s.l. genomes provide an excellent window into the processes of bacterial evolution at both within- and between-population levels. Comparative analyses of B. burgdorferi s.l. genomes revealed a highly dynamic plasmid composition but a conservative gene repertoire. Gene duplication and loss as well as sequence variations at loci encoding surface-localized lipoproteins (e.g., the PF54 genes) are strongly associated with adaptive differences between species. There are a great many conserved intergenic spacer sequences that are candidates for cis-regulatory elements and non-coding RNAs. Recombination among coexisting strains occurs at a rate approximately three times the mutation rate. The coexistence of a large number of genomic groups within local B. burgdorferi s.l. populations may be driven by immune-mediated diversifying selection targeting major antigen loci as well as by adaptation to multiple host species. Questions remain regarding the ecological causes (e.g., climate change, host movements, or new adaptations) of the ongoing range expansion of B. burgdorferi s.l. and on the genomic variations associated with its ecological and clinical variability. Anticipating an explosive growth of the number of B. burgdorferi s.l. genomes sampled from both within and among species, we propose genome-based methods to test adaptive mechanisms and to identify molecular bases of phenotypic variations. Genome sequencing is also necessary for monitoring a likely increase of genetic admixture of previously isolated species and populations in North America and elsewhere.
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Putignani L, Massa O, Alisi A. Engineered Escherichia coli as new source of flavonoids and terpenoids. Food Res Int 2013. [DOI: 10.1016/j.foodres.2013.01.062] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Skippington E, Ragan MA. Phylogeny rather than ecology or lifestyle biases the construction of Escherichia coli-Shigella genetic exchange communities. Open Biol 2013; 2:120112. [PMID: 23091700 PMCID: PMC3472396 DOI: 10.1098/rsob.120112] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Accepted: 08/20/2012] [Indexed: 11/12/2022] Open
Abstract
Genetic material can be transmitted not only vertically from parent to offspring, but also laterally (horizontally) from one bacterial lineage to another. Lateral genetic transfer is non-uniform; biases in its nature or frequency construct communities of genetic exchange. These biases have been proposed to arise from phylogenetic relatedness, shared ecology and/or common lifestyle. Here, we test these hypotheses using a graph-based abstraction of inferred genetic-exchange relationships among 27 Escherichia coli and Shigella genomes. We show that although barriers to inter-phylogenetic group lateral transfer are low, E. coli and Shigella are more likely to have exchanged genetic material with close relatives. We find little evidence of bias arising from shared environment or lifestyle. More than one-third of donor-recipient pairs in our analysis show some level of fragmentary gene transfer. Thus, within the E. coli-Shigella clade, intact genes and gene fragments have been disseminated non-uniformly and at appreciable frequency, constructing communities that transgress environmental and lifestyle boundaries.
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Affiliation(s)
- Elizabeth Skippington
- Institute for Molecular Bioscience and Australian Research Council Centre of Excellence in Bioinformatics, The University of Queensland, Brisbane, Queensland 4072, Australia
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Fitness, stress resistance, and extraintestinal virulence in Escherichia coli. Infect Immun 2013; 81:2733-42. [PMID: 23690401 DOI: 10.1128/iai.01329-12] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The extraintestinal virulence of Escherichia coli is dependent on numerous virulence genes. However, there is growing evidence for a role of the metabolic properties and stress responses of strains in pathogenesis. We assessed the respective roles of these factors in strain virulence by developing phenotypic assays for measuring in vitro individual and competitive fitness and the general stress response, which we applied to 82 commensal and extraintestinal pathogenic E. coli strains previously tested in a mouse model of sepsis. Individual fitness properties, in terms of maximum growth rates in various media (Luria-Bertani broth with and without iron chelator, minimal medium supplemented with gluconate, and human urine) and competitive fitness properties, estimated as the mean relative growth rate per generation in mixed cultures with a reference fluorescent E. coli strain, were highly diverse between strains. The activity of the main general stress response regulator, RpoS, as determined by iodine staining of the colonies, H2O2 resistance, and rpoS sequencing, was also highly variable. No correlation between strain fitness and stress resistance and virulence in the mouse model was found, except that the maximum growth rate in urine was higher for virulent strains. Multivariate analysis showed that the number of virulence factors was the only independent factor explaining the virulence in mice. At the species level, growth capacity and stress resistance are heterogeneous properties that do not contribute significantly to the intrinsic virulence of the strains.
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Lescat M, Clermont O, Woerther PL, Glodt J, Dion S, Skurnik D, Djossou F, Dupont C, Perroz G, Picard B, Catzeflis F, Andremont A, Denamur E. Commensal Escherichia coli strains in Guiana reveal a high genetic diversity with host-dependant population structure. ENVIRONMENTAL MICROBIOLOGY REPORTS 2013; 5:49-57. [PMID: 23757130 DOI: 10.1111/j.1758-2229.2012.00374.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Accepted: 07/21/2012] [Indexed: 05/02/2023]
Abstract
We undertook a large-scale epidemiological survey of commensal Escherichia coli in Trois-Sauts, an isolated village located in the south of French Guiana where human population exchanges are restricted and source of antibiotics controlled. Stools from 162 Wayampi Amerindians and rectal swabs from 33 human associated and 198 wild animals were collected in the close proximity of the village. The prevalence of E. coli was decreasing from humans (100%) to human associated (64%) and wild (45%) animals. A clear genetic structure between these three E. coli populations was observed with human strains belonging very rarely to B2 phylogroup (3.7%), exhibiting few virulence genes and bacteriocins but being antibiotic resistant whereas wild animal strains were characterized by 46.1% of B2 phylogroup belonging, with very unique and infrequent sequence types, numerous extraintestinal genes and bacteriocins but no antibiotic resistance; the human-associated animal strains being intermediate. Furthermore, an unexpected genetic diversity was observed among the strains, as the housekeeping gene nucleotide diversity per site of the Trois-Sauts's strains was higher than the one of reference strains representative of the known species diversity. The existence of such E. coli structured phylogenetic diversity within various hosts of a single localization has never been reported.
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Aubron C, Glodt J, Matar C, Huet O, Borderie D, Dobrindt U, Duranteau J, Denamur E, Conti M, Bouvet O. Variation in endogenous oxidative stress in Escherichia coli natural isolates during growth in urine. BMC Microbiol 2012; 12:120. [PMID: 22727065 PMCID: PMC3479029 DOI: 10.1186/1471-2180-12-120] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Accepted: 06/04/2012] [Indexed: 12/15/2022] Open
Abstract
Background Uropathogenic strains of Escherichia coli cause symptomatic infections whereas asymptomatic bacteriuria (ABU) strains are well adapted for growth in the human urinary tract, where they establish long-term bacteriuria. Human urine is a very complex growth medium that could be perceived by certain bacteria as a stressful environment. To investigate a possible imbalance between endogenous oxidative response and antioxidant mechanisms, lipid oxidative damage estimated as thiobarbituric acid reactive substances (TBARS) content was evaluated in twenty-one E. coli belonging to various pathovars and phylogenetic groups. Antioxidant defense mechanisms were also analysed. Results During exponential growth in urine, TBARS level differs between strains, without correlation with the ability to grow in urine which was similarly limited for commensal, ABU and uropathogenic strains. In addition, no correlation between TBARS level and the phylogroup or pathogenic group is apparent. The growth of ABU strain 83972 was associated with a high level of TBARS and more active antioxidant defenses that reduce the imbalance. Conclusions Our results indicate that growth capacity in urine is not a property of ABU strains. However, E. coli isolates respond very differently to this stressful environment. In strain ABU 83972, on one hand, the increased level of endogenous reactive oxygen species may be responsible for adaptive mutations. On the other hand, a more active antioxidant defense system could increase the capacity to colonize the bladder.
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Affiliation(s)
- Cecile Aubron
- UMR 722 INSERM and Université Paris Diderot, Sorbonne Paris Cité, Site Xavier Bichat, Paris, France
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Chaudhuri RR, Henderson IR. The evolution of the Escherichia coli phylogeny. INFECTION GENETICS AND EVOLUTION 2012; 12:214-26. [DOI: 10.1016/j.meegid.2012.01.005] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Revised: 01/04/2012] [Accepted: 01/05/2012] [Indexed: 10/14/2022]
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Skippington E, Ragan MA. Evolutionary dynamics of small RNAs in 27 Escherichia coli and Shigella genomes. Genome Biol Evol 2012; 4:330-45. [PMID: 22223756 PMCID: PMC3318445 DOI: 10.1093/gbe/evs001] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Small RNAs (sRNAs) are widespread in bacteria and play critical roles in regulating physiological processes. They are best characterized in Escherichia coli K-12 MG1655, where 83 sRNAs constitute nearly 2% of the gene complement. Most sRNAs act by base pairing with a target mRNA, modulating its translation and/or stability; many of these RNAs share only limited complementarity to their mRNA target, and require the chaperone Hfq to facilitate base pairing. Little is known about the evolutionary dynamics of bacterial sRNAs. Here, we apply phylogenetic and network analyses to investigate the evolutionary processes and principles that govern sRNA gene distribution in 27 E. coli and Shigella genomes. We identify core (encoded in all 27 genomes) and variable sRNAs; more than two-thirds of the E. coli K-12 MG1655 sRNAs are core, whereas the others show patterns of presence and absence that are principally due to genetic loss, not duplication or lateral genetic transfer. We present evidence that variable sRNAs are less tightly integrated into cellular genetic regulatory networks than are the core sRNAs, and that Hfq facilitates posttranscriptional cross talk between the E. coli–Shigella core and variable genomes. Finally, we present evidence that more than 80% of genes targeted by Hfq-associated core sRNAs have been transferred within the E. coli–Shigella clade, and that most of these genes have been transferred intact. These results suggest that Hfq and sRNAs help integrate laterally acquired genes into established regulatory networks.
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Levert M, Zamfir O, Clermont O, Bouvet O, Lespinats S, Hipeaux MC, Branger C, Picard B, Saint-Ruf C, Norel F, Balliau T, Zivy M, Le Nagard H, Cruvellier S, Chane-Woon-Ming B, Nilsson S, Gudelj I, Phan K, Ferenci T, Tenaillon O, Denamur E. Molecular and evolutionary bases of within-patient genotypic and phenotypic diversity in Escherichia coli extraintestinal infections. PLoS Pathog 2010; 6:e1001125. [PMID: 20941353 PMCID: PMC2947995 DOI: 10.1371/journal.ppat.1001125] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2010] [Accepted: 08/31/2010] [Indexed: 12/22/2022] Open
Abstract
Although polymicrobial infections, caused by combinations of viruses, bacteria, fungi and parasites, are being recognised with increasing frequency, little is known about the occurrence of within-species diversity in bacterial infections and the molecular and evolutionary bases of this diversity. We used multiple approaches to study the genomic and phenotypic diversity among 226 Escherichia coli isolates from deep and closed visceral infections occurring in 19 patients. We observed genomic variability among isolates from the same site within 11 patients. This diversity was of two types, as patients were infected either by several distinct E. coli clones (4 patients) or by members of a single clone that exhibit micro-heterogeneity (11 patients); both types of diversity were present in 4 patients. A surprisingly wide continuum of antibiotic resistance, outer membrane permeability, growth rate, stress resistance, red dry and rough morphotype characteristics and virulence properties were present within the isolates of single clones in 8 of the 11 patients showing genomic micro-heterogeneity. Many of the observed phenotypic differences within clones affected the trade-off between self-preservation and nutritional competence (SPANC). We showed in 3 patients that this phenotypic variability was associated with distinct levels of RpoS in co-existing isolates. Genome mutational analysis and global proteomic comparisons in isolates from a patient revealed a star-like relationship of changes amongst clonally diverging isolates. A mathematical model demonstrated that multiple genotypes with distinct RpoS levels can co-exist as a result of the SPANC trade-off. In the cases involving infection by a single clone, we present several lines of evidence to suggest diversification during the infectious process rather than an infection by multiple isolates exhibiting a micro-heterogeneity. Our results suggest that bacteria are subject to trade-offs during an infectious process and that the observed diversity resembled results obtained in experimental evolution studies. Whatever the mechanisms leading to diversity, our results have strong medical implications in terms of the need for more extensive isolate testing before deciding on antibiotic therapies. We investigated whether an infection is a site of pathogen within-species diversity. Our results indicate that there is indeed extensive diversity during human extraintestinal infections by Escherichia coli. This diversity was of two types, not mutually exclusive, as we found that patients were infected either by several distinct E. coli clones or by members of a single clone that exhibit micro-heterogeneity. The high degree of phenotypic diversity, including antibiotic resistance, suggests that there is no uniform selection pressure leading to a single fitter clone during an infection. We discuss a possible mechanism and a mathematical model that explains these unexpected results. Our data suggest that the evolution of diversity in the course of an infection and in in vitro experimental evolution in the absence of host immune selective pressure may have many parallels. Whatever the mechanisms leading to diversity, our results have strong medical implications in terms of the need for more extensive isolate testing before deciding on antibiotic therapies.
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Affiliation(s)
- Maxime Levert
- INSERM U722 and Université Paris 7 Denis Diderot, Faculté de Médecine, Site Xavier Bichat, Paris, France
| | - Oana Zamfir
- INSERM U722 and Université Paris 7 Denis Diderot, Faculté de Médecine, Site Xavier Bichat, Paris, France
| | - Olivier Clermont
- INSERM U722 and Université Paris 7 Denis Diderot, Faculté de Médecine, Site Xavier Bichat, Paris, France
| | - Odile Bouvet
- INSERM U722 and Université Paris 7 Denis Diderot, Faculté de Médecine, Site Xavier Bichat, Paris, France
| | - Sylvain Lespinats
- INSERM U722 and Université Paris 7 Denis Diderot, Faculté de Médecine, Site Xavier Bichat, Paris, France
| | - Marie Claire Hipeaux
- Assistance Publique - Hôpitaux de Paris, Hôpital Louis Mourier, Laboratoire de Microbiologie, Colombes, France
| | - Catherine Branger
- INSERM U722 and Université Paris 7 Denis Diderot, Faculté de Médecine, Site Xavier Bichat, Paris, France
- Assistance Publique - Hôpitaux de Paris, Hôpital Louis Mourier, Laboratoire de Microbiologie, Colombes, France
| | - Bertrand Picard
- INSERM U722 and Université Paris 7 Denis Diderot, Faculté de Médecine, Site Xavier Bichat, Paris, France
| | - Claude Saint-Ruf
- INSERM U1001 and Université Paris 5 René Descartes, Faculté de Médecine, Paris, France
| | - Françoise Norel
- Unité de Génétique Moléculaire and CNRS URA2172, Institut Pasteur, Paris, France
| | - Thierry Balliau
- CNRS UMR 0320/UMR8120 Génétique Végétale, Plate-Forme de Protéomique PAPPSO, Gif-sur-Yvette, France
| | - Michel Zivy
- CNRS UMR 0320/UMR8120 Génétique Végétale, Plate-Forme de Protéomique PAPPSO, Gif-sur-Yvette, France
| | - Hervé Le Nagard
- INSERM U738 and Université Paris 7 Denis Diderot, Faculté de Médecine, Site Xavier Bichat, Paris, France
| | - Stéphane Cruvellier
- Laboratoire de Génomique Comparative, CNRS UMR8030, Institut de Génomique, CEA, Genoscope, Evry, France
| | - Béatrice Chane-Woon-Ming
- Laboratoire de Génomique Comparative, CNRS UMR8030, Institut de Génomique, CEA, Genoscope, Evry, France
| | - Susanna Nilsson
- Department of Mathematics, Imperial College, London, United Kingdom
| | - Ivana Gudelj
- Department of Mathematics, Imperial College, London, United Kingdom
| | - Katherine Phan
- School of Molecular Bioscience, University of Sydney, Sydney, New South Wales, Australia
| | - Thomas Ferenci
- School of Molecular Bioscience, University of Sydney, Sydney, New South Wales, Australia
| | - Olivier Tenaillon
- INSERM U722 and Université Paris 7 Denis Diderot, Faculté de Médecine, Site Xavier Bichat, Paris, France
| | - Erick Denamur
- INSERM U722 and Université Paris 7 Denis Diderot, Faculté de Médecine, Site Xavier Bichat, Paris, France
- * E-mail:
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Adiba S, Nizak C, van Baalen M, Denamur E, Depaulis F. From grazing resistance to pathogenesis: the coincidental evolution of virulence factors. PLoS One 2010; 5:e11882. [PMID: 20711443 PMCID: PMC2920306 DOI: 10.1371/journal.pone.0011882] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2010] [Accepted: 07/09/2010] [Indexed: 11/29/2022] Open
Abstract
To many pathogenic bacteria, human hosts are an evolutionary dead end. This begs the question what evolutionary forces have shaped their virulence traits. Why are these bacteria so virulent? The coincidental evolution hypothesis suggests that such virulence factors result from adaptation to other ecological niches. In particular, virulence traits in bacteria might result from selective pressure exerted by protozoan predator. Thus, grazing resistance may be an evolutionarily exaptation for bacterial pathogenicity. This hypothesis was tested by subjecting a well characterized collection of 31 Escherichia coli strains (human commensal or extra-intestinal pathogenic) to grazing by the social haploid amoeba Dictyostelium discoideum. We then assessed how resistance to grazing correlates with some bacterial traits, such as the presence of virulence genes. Whatever the relative population size (bacteria/amoeba) for a non-pathogenic bacteria strain, D. discoideum was able to phagocytise, digest and grow. In contrast, a pathogenic bacterium strain killed D. discoideum above a certain bacteria/amoeba population size. A plating assay was then carried out using the E. coli collection faced to the grazing of D. discoideum. E. coli strains carrying virulence genes such as iroN, irp2, fyuA involved in iron uptake, belonging to the B2 phylogenetic group and being virulent in a mouse model of septicaemia were resistant to the grazing from D. discoideum. Experimental proof of the key role of the irp gene in the grazing resistance was evidenced with a mutant strain lacking this gene. Such determinant of virulence may well be originally selected and (or) further maintained for their role in natural habitat: resistance to digestion by free-living protozoa, rather than for virulence per se.
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Affiliation(s)
- Sandrine Adiba
- Laboratoire d'Ecologie, CNRS UMR7625, Université Pierre et Marie Curie, Paris Universitas, Paris, France.
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Abstract
The primary habitat of Escherichia coli is the vertebrate gut, where it is the predominant aerobic organism, living in symbiosis with its host. Despite the occurrence of recombination events, the population structure is predominantly clonal, allowing the delineation of major phylogenetic groups. The genetic structure of commensal E. coli is shaped by multiple host and environmental factors, and the determinants involved in the virulence of the bacteria may in fact reflect adaptation to commensal habitats. A better characterization of the commensal niche is necessary to understand how a useful commensal can become a harmful pathogen. In this Review we describe the population structure of commensal E. coli, the factors involved in the spread of different strains, how the bacteria can adapt to different niches and how a commensal lifestyle can evolve into a pathogenic one.
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Lescat M, Hoede C, Clermont O, Garry L, Darlu P, Tuffery P, Denamur E, Picard B. aes, the gene encoding the esterase B in Escherichia coli, is a powerful phylogenetic marker of the species. BMC Microbiol 2009; 9:273. [PMID: 20040078 PMCID: PMC2805673 DOI: 10.1186/1471-2180-9-273] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2009] [Accepted: 12/29/2009] [Indexed: 11/30/2022] Open
Abstract
Background Previous studies have established a correlation between electrophoretic polymorphism of esterase B, and virulence and phylogeny of Escherichia coli. Strains belonging to the phylogenetic group B2 are more frequently implicated in extraintestinal infections and include esterase B2 variants, whereas phylogenetic groups A, B1 and D contain less virulent strains and include esterase B1 variants. We investigated esterase B as a marker of phylogeny and/or virulence, in a thorough analysis of the esterase B-encoding gene. Results We identified the gene encoding esterase B as the acetyl-esterase gene (aes) using gene disruption. The analysis of aes nucleotide sequences in a panel of 78 reference strains, including the E. coli reference (ECOR) strains, demonstrated that the gene is under purifying selection. The phylogenetic tree reconstructed from aes sequences showed a strong correlation with the species phylogenetic history, based on multi-locus sequence typing using six housekeeping genes. The unambiguous distinction between variants B1 and B2 by electrophoresis was consistent with Aes amino-acid sequence analysis and protein modelling, which showed that substituted amino acids in the two esterase B variants occurred mostly at different sites on the protein surface. Studies in an experimental mouse model of septicaemia using mutant strains did not reveal a direct link between aes and extraintestinal virulence. Moreover, we did not find any genes in the chromosomal region of aes to be associated with virulence. Conclusion Our findings suggest that aes does not play a direct role in the virulence of E. coli extraintestinal infection. However, this gene acts as a powerful marker of phylogeny, illustrating the extensive divergence of B2 phylogenetic group strains from the rest of the species.
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Skurnik D, Lacheeb S, Bernede C, le Menac'H A, Elbaz S, Mohler J, Denamur E, Andremont A, Ruimy R. Integrons and Antibiotic Resistance in Phylogenetic Group B2Escherichia coli. Microb Drug Resist 2009; 15:173-8. [DOI: 10.1089/mdr.2009.0918] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- David Skurnik
- EA3964, In-vivo Bacterial Resistance, University Paris 7 Denis Diderot and University Hospital Bichat-Claude Bernard, Public Assistance Hospital of Paris (APHP), Paris, France
| | - Sonia Lacheeb
- EA3964, In-vivo Bacterial Resistance, University Paris 7 Denis Diderot and University Hospital Bichat-Claude Bernard, Public Assistance Hospital of Paris (APHP), Paris, France
| | - Claire Bernede
- CeRBEP, Pasteur Institute, National Institute of Health and Medical Research (INSERM) U657, Paris, France
| | | | - Sandrine Elbaz
- EA3964, In-vivo Bacterial Resistance, University Paris 7 Denis Diderot and University Hospital Bichat-Claude Bernard, Public Assistance Hospital of Paris (APHP), Paris, France
| | - Jacqueline Mohler
- EA3964, In-vivo Bacterial Resistance, University Paris 7 Denis Diderot and University Hospital Bichat-Claude Bernard, Public Assistance Hospital of Paris (APHP), Paris, France
| | - Erick Denamur
- INSERM U722 and University Paris 7 Denis Diderot, Paris, France
| | - Antoine Andremont
- EA3964, In-vivo Bacterial Resistance, University Paris 7 Denis Diderot and University Hospital Bichat-Claude Bernard, Public Assistance Hospital of Paris (APHP), Paris, France
| | - Raymond Ruimy
- EA3964, In-vivo Bacterial Resistance, University Paris 7 Denis Diderot and University Hospital Bichat-Claude Bernard, Public Assistance Hospital of Paris (APHP), Paris, France
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Touchon M, Hoede C, Tenaillon O, Barbe V, Baeriswyl S, Bidet P, Bingen E, Bonacorsi S, Bouchier C, Bouvet O, Calteau A, Chiapello H, Clermont O, Cruveiller S, Danchin A, Diard M, Dossat C, Karoui ME, Frapy E, Garry L, Ghigo JM, Gilles AM, Johnson J, Le Bouguénec C, Lescat M, Mangenot S, Martinez-Jéhanne V, Matic I, Nassif X, Oztas S, Petit MA, Pichon C, Rouy Z, Ruf CS, Schneider D, Tourret J, Vacherie B, Vallenet D, Médigue C, Rocha EPC, Denamur E. Organised genome dynamics in the Escherichia coli species results in highly diverse adaptive paths. PLoS Genet 2009; 5:e1000344. [PMID: 19165319 PMCID: PMC2617782 DOI: 10.1371/journal.pgen.1000344] [Citation(s) in RCA: 778] [Impact Index Per Article: 51.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2008] [Accepted: 12/16/2008] [Indexed: 01/01/2023] Open
Abstract
The Escherichia coli species represents one of the best-studied model organisms, but also encompasses a variety of commensal and pathogenic strains that diversify by high rates of genetic change. We uniformly (re-) annotated the genomes of 20 commensal and pathogenic E. coli strains and one strain of E. fergusonii (the closest E. coli related species), including seven that we sequenced to completion. Within the ∼18,000 families of orthologous genes, we found ∼2,000 common to all strains. Although recombination rates are much higher than mutation rates, we show, both theoretically and using phylogenetic inference, that this does not obscure the phylogenetic signal, which places the B2 phylogenetic group and one group D strain at the basal position. Based on this phylogeny, we inferred past evolutionary events of gain and loss of genes, identifying functional classes under opposite selection pressures. We found an important adaptive role for metabolism diversification within group B2 and Shigella strains, but identified few or no extraintestinal virulence-specific genes, which could render difficult the development of a vaccine against extraintestinal infections. Genome flux in E. coli is confined to a small number of conserved positions in the chromosome, which most often are not associated with integrases or tRNA genes. Core genes flanking some of these regions show higher rates of recombination, suggesting that a gene, once acquired by a strain, spreads within the species by homologous recombination at the flanking genes. Finally, the genome's long-scale structure of recombination indicates lower recombination rates, but not higher mutation rates, at the terminus of replication. The ensuing effect of background selection and biased gene conversion may thus explain why this region is A+T-rich and shows high sequence divergence but low sequence polymorphism. Overall, despite a very high gene flow, genes co-exist in an organised genome. Although abundant knowledge has been accumulated regarding the E. coli laboratory strain K-12, little is known about the evolutionary trajectories that have driven the high diversity observed among natural isolates of the species, which encompass both commensal and highly virulent intestinal and extraintestinal pathogenic strains. We have annotated or re-annotated the genomes of 20 commensal and pathogenic E. coli strains and one strain of E. fergusonii (the closest E. coli related species), including seven that we sequenced to completion. Although recombination rates are much higher than mutation rates, we were able to reconstruct a robust phylogeny based on the ∼2,000 genes common to all strains. Based on this phylogeny, we established the evolutionary scenario of gains and losses of thousands of specific genes, identifying functional classes under opposite selection pressures. This genome flux is confined to very few positions in the chromosome, which are the same for every genome. Notably, we identified few or no extraintestinal virulence-specific genes. We also defined a long-scale structure of recombination in the genome with lower recombination rates at the terminus of replication. These findings demonstrate that, despite a very high gene flow, genes can co-exist in an organised genome.
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Affiliation(s)
- Marie Touchon
- Atelier de BioInformatique, Université Pierre et Marie Curie - Paris 6 (UPMC), Paris, France
- Microbial Evolutionary Genomics, Institut Pasteur, CNRS URA2171, Paris, France
| | - Claire Hoede
- Faculté de Médecine, Université Paris 7 Denis Diderot, INSERM U722, Site Xavier Bichat, Paris, France
| | - Olivier Tenaillon
- Faculté de Médecine, Université Paris 7 Denis Diderot, INSERM U722, Site Xavier Bichat, Paris, France
| | | | - Simon Baeriswyl
- Faculté de Médecine, Université Paris 5 René Descartes, INSERM U571, Paris, France
| | - Philippe Bidet
- Université Paris 7 Denis Diderot, Hôpital Robert Debré (APHP), EA 3105, Paris, France
| | - Edouard Bingen
- Université Paris 7 Denis Diderot, Hôpital Robert Debré (APHP), EA 3105, Paris, France
| | - Stéphane Bonacorsi
- Université Paris 7 Denis Diderot, Hôpital Robert Debré (APHP), EA 3105, Paris, France
| | | | - Odile Bouvet
- Faculté de Médecine, Université Paris 7 Denis Diderot, INSERM U722, Site Xavier Bichat, Paris, France
| | - Alexandra Calteau
- Laboratoire de Génomique Comparative, CNRS UMR8030, Institut de Génomique, CEA, Génoscope, Evry, France
| | - Hélène Chiapello
- UR1077 Mathématique, Informatique, et Génome, INRA, Jouy en Josas, France
| | - Olivier Clermont
- Faculté de Médecine, Université Paris 7 Denis Diderot, INSERM U722, Site Xavier Bichat, Paris, France
| | - Stéphane Cruveiller
- Laboratoire de Génomique Comparative, CNRS UMR8030, Institut de Génomique, CEA, Génoscope, Evry, France
| | - Antoine Danchin
- Unité de Génétique des Génomes Bactériens, Institut Pasteur, CNRS URA2171, Paris, France
| | - Médéric Diard
- Faculté de Médecine, Université Paris 5 René Descartes, INSERM U571, Paris, France
| | | | - Meriem El Karoui
- UR888 Unité des Bactéries Lactiques et Pathogènes Opportunistes, INRA, Jouy en Josas, France
| | - Eric Frapy
- Faculté de Médecine, Université Paris 5 René Descartes, INSERM U570, Paris, France
| | - Louis Garry
- Faculté de Médecine, Université Paris 7 Denis Diderot, INSERM U722, Site Xavier Bichat, Paris, France
| | - Jean Marc Ghigo
- Unité de Génétique des Biofilms, Institut Pasteur, CNRS URA2172, Paris, France
| | - Anne Marie Gilles
- Unité de Génétique des Génomes Bactériens, Institut Pasteur, CNRS URA2171, Paris, France
| | - James Johnson
- Veterans Affairs Medical Center, Minneapolis, Minnesota, United States of America
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota, United States of America
| | | | - Mathilde Lescat
- Faculté de Médecine, Université Paris 7 Denis Diderot, INSERM U722, Site Xavier Bichat, Paris, France
| | | | | | - Ivan Matic
- Faculté de Médecine, Université Paris 5 René Descartes, INSERM U571, Paris, France
| | - Xavier Nassif
- Faculté de Médecine, Université Paris 5 René Descartes, INSERM U570, Paris, France
| | - Sophie Oztas
- Génoscope, Institut de Génomique, CEA, Evry, France
| | - Marie Agnès Petit
- UR888 Unité des Bactéries Lactiques et Pathogènes Opportunistes, INRA, Jouy en Josas, France
| | - Christophe Pichon
- Pathogénie Bactérienne des Muqueuses, Institut Pasteur, Paris, France
| | - Zoé Rouy
- Laboratoire de Génomique Comparative, CNRS UMR8030, Institut de Génomique, CEA, Génoscope, Evry, France
| | - Claude Saint Ruf
- Faculté de Médecine, Université Paris 5 René Descartes, INSERM U571, Paris, France
| | | | - Jérôme Tourret
- Faculté de Médecine, Université Paris 7 Denis Diderot, INSERM U722, Site Xavier Bichat, Paris, France
| | | | - David Vallenet
- Laboratoire de Génomique Comparative, CNRS UMR8030, Institut de Génomique, CEA, Génoscope, Evry, France
| | - Claudine Médigue
- Laboratoire de Génomique Comparative, CNRS UMR8030, Institut de Génomique, CEA, Génoscope, Evry, France
- * E-mail: (CM); (EPCR); (ED)
| | - Eduardo P. C. Rocha
- Atelier de BioInformatique, Université Pierre et Marie Curie - Paris 6 (UPMC), Paris, France
- Microbial Evolutionary Genomics, Institut Pasteur, CNRS URA2171, Paris, France
- * E-mail: (CM); (EPCR); (ED)
| | - Erick Denamur
- Faculté de Médecine, Université Paris 7 Denis Diderot, INSERM U722, Site Xavier Bichat, Paris, France
- * E-mail: (CM); (EPCR); (ED)
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Gordon DM, Clermont O, Tolley H, Denamur E. Assigning Escherichia coli strains to phylogenetic groups: multi-locus sequence typing versus the PCR triplex method. Environ Microbiol 2008; 10:2484-96. [PMID: 18518895 DOI: 10.1111/j.1462-2920.2008.01669.x] [Citation(s) in RCA: 219] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
It is well recognized that Escherichia coli consists of a number of distinct phylo-groups and that strains of the different phylo-groups vary in their ecological niches, life-history characteristics and propensity to cause disease. Consequently, much can be learnt by assigning a strain of E. coli to one of the recognized phylo-groups. A triplex PCR-based method that enables strains of E. coli to be assigned to a phylo-group using a dichotomous key approach based on the presence or absence of two genes (chuA and yjaA) and an anonymous DNA fragment (TSPE4.C2) has been developed. However, the accuracy with which this method assigns strains to their correct phylo-group has not been adequately evaluated. Consequently, 662 strains of E. coli were characterized using a multi-locus sequence typing approach. Unsupervised population assignment algorithms were used to assign strains to phylo-groups based on the multi-locus sequence typing data. The analyses revealed that 85-90% of E. coli strains can be assigned to a phylo-group and that 80-85% of the phylo-group memberships assigned using the Clermont method are correct. However, the accuracy with which strains are assigned to the correct phylo-group depends on their Clermont genotype. For example, strains yielding a Clermont genotype consistent with phylo-groups B1 and B2 are assigned correctly 95% of the time. Strains failing to yield any PCR products using the Clermont method are seldom members of phylo-group A and strains with such a genotype should not be assigned to a phylo-group.
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Affiliation(s)
- David M Gordon
- School of Botany and Zoology, Australian National University, Canberra ACT 0200, Australia.
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Homma K, Fukuchi S, Nakamura Y, Gojobori T, Nishikawa K. Gene Cluster Analysis Method Identifies Horizontally Transferred Genes with High Reliability and Indicates that They Provide the Main Mechanism of Operon Gain in 8 Species of γ-Proteobacteria. Mol Biol Evol 2006; 24:805-13. [PMID: 17185745 DOI: 10.1093/molbev/msl206] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The formation mechanism of operons remains unresolved: operons may form by rearrangements within a genome or by acquisition of genes from other species, that is, horizontal gene transfer (HGT). One hindrance to its elucidation is the unavailability of a method to accurately identify HGT, although it is generally considered to occur. It is critically important first to select horizontally transferred (HT) genes reliably and then to determine the extent to which HGT is involved in operon formation. For this purpose, we considered indels in terms of gene clusters instead of individual genes and chose candidates of HT genes in 8 species of Escherichia, Shigella, and Salmonella based on the minimization of indels. To select a benchmark set of positively HT genes against which we can evaluate the candidate set, we devised another procedure using intergenetic alignments. Comparison with the benchmark set demonstrated the absence of a significant number of false positives in the candidate set, showing the high reliability of the method. Analyses of Escherichia coli K-12 operons revealed that although approximately 20 operons were probably gained from the last common ancestor of the 8 gamma-proteobacteria, deletion of intervening genes accounts for the formation of no operons, whereas horizontal transfer expanded 2 operons and introduced 4 entire operons. Based on these observations and reasoning, we suggest that the main mechanism of operon gain is HGT rather than intragenomic rearrangements. We propose that genes with related essential functions tend to reside in conserved operons, whereas genes in nonconserved operons mostly confer slight advantage to the organisms and frequently undergo horizontal transfer and decay. HT genes constitute at least 5.5% of the genes in the 8 species and approximately 45% of which originate from other gamma-proteobacteria. Genes involved in viral functions and mobile and extrachromosomal element functions are HT more often than expected. This finding indicates frequent mediation of HGT by bacteriophages. On the other hand, not only informational genes (those involved in transcription, translation, and related processes) but also operational genes (those involved in housekeeping) are HT less frequently than expected.
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Affiliation(s)
- Keiichi Homma
- Center for Information Biology-DNA Data Bank of Japan, National Institute of Genetics, Research Organization of Information and Systems, Mishima, Shizuoka 411-8540, Japan
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Escobar-Páramo P, Le Menac'h A, Le Gall T, Amorin C, Gouriou S, Picard B, Skurnik D, Denamur E. Identification of forces shaping the commensal Escherichia coli genetic structure by comparing animal and human isolates. Environ Microbiol 2006; 8:1975-84. [PMID: 17014496 DOI: 10.1111/j.1462-2920.2006.01077.x] [Citation(s) in RCA: 165] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To identify forces shaping the Escherichia coli intraspecies ecological structure, we have characterized in terms of phylogenetic group (A, B1, D and B2) belonging, presence/absence of extraintestinal virulence genes (pap, sfa, hly and aer) and intra-host phylotype diversity a collection of 1898 commensal isolates originating from 387 animals (birds and mammals) sampled in the 1980s and the 2000s. These data have been compared with 760 human commensal isolates, sampled from 152 healthy subjects in the 2000s, and analysed with the same approach. The prevalence of the E. coli phylogenetic groups in birds, non-human mammals and humans is clearly different with a predominance of D/B1, A/B1 and A/B2 strains respectively. A major force shaping the ecological structure is the environment with a strong effect of domestication and the year of sampling followed by the climate. Host characteristics, as the diet and body mass, also influence the ecological structure. Human microbiota are characterized by a higher prevalence of virulence genes and a lower intra-host diversity than the non-human mammal ones. This work identifies for the first time a group of strains specific to the animals, the B1 phylogenetic group strains exhibiting the hly gene. In conclusion, a complex network of factors seems to shape the ecological structure of commensal E. coli, with anthropogenic factors playing a major role and perturbing natural niche equilibrium.
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Hommais F, Pereira S, Acquaviva C, Escobar-Páramo P, Denamur E. Single-nucleotide polymorphism phylotyping of Escherichia coli. Appl Environ Microbiol 2005; 71:4784-92. [PMID: 16085876 PMCID: PMC1183324 DOI: 10.1128/aem.71.8.4784-4792.2005] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We describe a rapid and easily automated phylogenetic grouping technique based on analysis of bacterial genome single-nucleotide polymorphisms (SNPs). We selected 13 SNPs derived from a complete sequence analysis of 11 essential genes previously used for multilocus sequence typing (MLST) of 30 Escherichia coli strains representing the genetic diversity of the species. The 13 SNPs were localized in five genes, trpA, trpB, putP, icdA, and polB, and were selected to allow recovery of the main phylogenetic groups (groups A, B1, E, D, and B2) and subgroups of the species. In the first step, we validated the SNP approach in silico by extracting SNP data from the complete sequences of the five genes for a panel of 65 pathogenic strains belonging to different E. coli pathovars, which were previously analyzed by MLST. In the second step, we determined these SNPs by dideoxy single-base extension of unlabeled oligonucleotide primers for a collection of 183 commensal and extraintestinal clinical E. coli isolates and compared the SNP phylotyping method to previous well-established typing methods. This SNP phylotyping method proved to be consistent with the other methods for assigning phylogenetic groups to the different E. coli strains. In contrast to the other typing methods, such as multilocus enzyme electrophoresis, ribotyping, or PCR phylotyping using the presence/absence of three genomic DNA fragments, the SNP typing method described here is derived from a solid phylogenetic analysis, and the results obtained by this method are more meaningful. Our results indicate that similar approaches may be used for a wide variety of bacterial species.
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Affiliation(s)
- Florence Hommais
- UMR 5122, Université Claude Bernard Lyon 1, 10 rue Dubois, 69622 Villeurbanne cedex, France.
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Bonacorsi S, Bingen E. Molecular epidemiology of Escherichia coli causing neonatal meningitis. Int J Med Microbiol 2005; 295:373-81. [PMID: 16238014 DOI: 10.1016/j.ijmm.2005.07.011] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Escherichia coli is the second cause of neonatal meningitis which is a major cause of neonatal mortality and is associated with a high incidence of neurological sequelae. E. coli neonatal meningitis (ECNM) strains, as other extraintestinal pathogenic E. coli, mainly belong to the phylogenetic group B2 and to a lesser extent to group D, but are distributed in fewer clonal groups. One of these, the O18:K1:H7 clone is worldwide distributed meanwhile others such as O83:K1 and O45:K1 are restricted to some countries. Over the past few years, major progress has been made in the understanding of the pathophysiology of E. coli O18:K1:H7 neonatal meningitis. In particular, specific virulence factors have been identified and are known to be carried by ectochromosomal DNA in most cases. Molecular epidemiological studies, including characterization of virulence genotypes and phylogenetic analysis are important to lead to a comprehensive picture of the origins and spread of virulence factors within the population of ECNM strains. To date, all the known genetic determinants obtained in ECNM strains are not sufficient to explain their virulence in their globality and further studies on clonal groups different from the archetypal O18:K1:H7 clone are needed. These studies would serve to find common pathogenic mechanisms among different ECNM clonal groups that may be used as potential target for a worldwide efficacious prevention strategy.
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Affiliation(s)
- Stéphane Bonacorsi
- Laboratoire d'études de génétique bactérienne dans les infections de l'enfant (EA3105), Université Denis Diderot-Paris 7, Service de Microbiologie, Hôpital Robert Debré (AP-HP), Paris, France
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Abstract
When are populations of infectious agents likely to evolve into distinct strains? Are they likely to differ in their virulence? Will genetically distinct strains or clones remain stable long enough to be useful as epidemiological markers? Sexual recombination can break down the genetic associations that define a strain structure, but if sex is rare or inbreeding is common, can strains persist? In this paper Ian Hastings and Bruce Wedgwood-Oppenheim show how some simple population genetic theory may provide a basis for addressing these questions.
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Affiliation(s)
- I M Hastings
- Laboratoire Génétique Moléculaire des Parasites et des Vecteurs, ORSTOM, 911 Av. Agropolis, Montpellier 34032, France.
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Shi B, Xia X. Genetic variation in clones of Pseudomonas pseudoalcaligenes after ten months of selection in different thermal environments in the laboratory. Curr Microbiol 2005; 50:238-45. [PMID: 15886916 DOI: 10.1007/s00284-004-4449-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2004] [Accepted: 11/08/2004] [Indexed: 11/29/2022]
Abstract
The random amplification of polymorphic DNA (RAPD) method was used to examine genetic variation in experimental clones of Pseudomonas pseudoalcaligenes in two experimental groups, as well as their common ancestor. Six clones derived from a single colony of P. pseudoalcaligenes were cultured in two different thermal regimes for 10 months. Three clones in the Control group were cultured at constant temperature of 35 degrees C and another three clones in the High Temperature (HT) group were propagated at incremental temperature ranging from 41 to 47 degrees C for 10 months. A total of 45 RAPD primers generated 146 polymorphic markers. Analysis of molecular variance (AMOVA) revealed mild (11%) but significant (P < 0.001) genetic difference between the Control and the HT clones. Phylogenetic analysis based on pairwise genetic distances showed that the HT clones were more divergent from the ancestor and from each other than the Control clones, implying that the HT clones of P. pseudoalcaligenes may have evolved faster than the Control clones.
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Affiliation(s)
- Bihong Shi
- Department of Ecology & Biodiversity, University of Hong Kong, Hong Kong, China.
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Branger C, Zamfir O, Geoffroy S, Laurans G, Arlet G, Thien HV, Gouriou S, Picard B, Denamur E. Genetic background of Escherichia coli and extended-spectrum beta-lactamase type. Emerg Infect Dis 2005; 11:54-61. [PMID: 15705323 PMCID: PMC3294364 DOI: 10.3201/eid1101.040257] [Citation(s) in RCA: 132] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
ESBL-producing E. coli may arise from interactions between ESBL type, strain genetic background, and selective pressures in various ecologic niches. To assess the implication of the genetic background of Escherichia coli strains in the emergence of extended-spectrum-β-lactamases (ESBL), 55 TEM-, 52 CTX-M-, and 22 SHV-type ESBL-producing clinical isolates involved in various extraintestinal infections or colonization were studied in terms of phylogenetic group, virulence factor (VF) content (pap, sfa/foc, hly, and aer genes), and fluoroquinolone resistance. A factorial analysis of correspondence showed that SHV type, and to a lesser extent TEM type, were preferentially observed in B2 phylogenetic group strains that exhibited numerous VFs but were fluoroquinolone-susceptible, whereas the newly emerged CTX-M type was associated with the D phylogenetic group strains that lacked VF but were fluoroquinolone-resistant. Thus, the emergence of ESBL-producing E. coli seems to be the result of complex interactions between the type of ESBL, genetic background of the strain, and selective pressures in ecologic niches.
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Affiliation(s)
- Catherine Branger
- Laboratoire de Microbiologie, Hôpital Louis Mourier, AP-HP, 178 Rue des Renouillers, 92701 Colombes Cedex, France.
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45
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Gordon DM. The Influence of Ecological Factors on the Distribution and the Genetic Structure of Escherichia coli. EcoSal Plus 2004; 1. [PMID: 26443349 DOI: 10.1128/ecosalplus.6.4.1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2003] [Indexed: 06/05/2023]
Abstract
This review focuses on recent data concerning the ecological factors that determine the distribution of Escherichia coli and the genetic structures of naturally occurring E. coli populations. It summarizes some of the older literature concerning the dynamics of E. coli populations within a host and poses some questions that arise from our more recently acquired understanding of the factors affecting the genetic structures of E. coli populations. Multilocus enzyme electrophoresis (MLEE) studies indicate that E. coli, relative to other members of the family Enterobacteriaceae, exhibits a moderate degree of genetic diversity. The existence of subspecific structure in E. coli has for the most part been determined by largely neutral in its effects on the fitness of a strain. The consequences for E. coli of the transition between its primary and secondary habitats are of considerable practical significance for water quality assessment and disease transmission. E. coli causes a significant fraction of human bacterial disease and is responsible for two main types of disease in humans and domestic animals: diarrheal disease and extraintestinal infections. The observed distribution of strains from the different E. coli genetic groups indicates that they have different life history tactics and ecological niches. A and B1 strains appear to be generalists, as they can be recovered from any vertebrate group. Group B2 and D strains appear to be more specialized, as they are largely restricted to endothermic vertebrates.
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Escobar-Páramo P, Grenet K, Le Menac'h A, Rode L, Salgado E, Amorin C, Gouriou S, Picard B, Rahimy MC, Andremont A, Denamur E, Ruimy R. Large-scale population structure of human commensal Escherichia coli isolates. Appl Environ Microbiol 2004; 70:5698-700. [PMID: 15345464 PMCID: PMC520916 DOI: 10.1128/aem.70.9.5698-5700.2004] [Citation(s) in RCA: 174] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The study of several Escherichia coli intestinal commensal isolates per individual in 265 healthy human subjects belonging to seven populations distributed worldwide showed that the E. coli population is highly structured, with major differences between the tropical and temperate populations.
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Baquero F. From pieces to patterns: evolutionary engineering in bacterial pathogens. Nat Rev Microbiol 2004; 2:510-8. [PMID: 15152207 DOI: 10.1038/nrmicro909] [Citation(s) in RCA: 127] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Fernando Baquero
- Department of Microbiology, University Hospital Ramón y Cajal, IMSALUD 28034, Madrid, Spain.
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49
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Koreen L, Ramaswamy SV, Graviss EA, Naidich S, Musser JM, Kreiswirth BN. spa typing method for discriminating among Staphylococcus aureus isolates: implications for use of a single marker to detect genetic micro- and macrovariation. J Clin Microbiol 2004; 42:792-9. [PMID: 14766855 PMCID: PMC344479 DOI: 10.1128/jcm.42.2.792-799.2004] [Citation(s) in RCA: 359] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Strain typing of microbial pathogens has two major aims: (i). to index genetic microvariation for use in outbreak investigations and (ii). to index genetic macrovariation for use in phylogenetic and population-based analyses. Until now, there has been no clear indication that one genetic marker can efficiently be used for both purposes. Previously, we had shown that DNA sequence analysis of the protein A gene variable repeat region (spa typing) provides a rapid and accurate method to discriminate Staphylococcus aureus outbreak isolates from those deemed epidemiologically unrelated. Here, using the hypothesis that the genetic macrovariation within a low-level recombinogenic species would accurately be characterized by a single-locus marker, we tested whether spa typing could congruently index the extensive genetic variation detected by a whole-genome DNA microarray in a collection of 36 isolates, which was recovered from 10 countries on four continents over a period of four decades, that is representative of the breadth of diversity within S. aureus. Using spa and coa typing, pulsed-field gel electrophoresis (PFGE), and microarray and multilocus enzyme electrophoresis (MLEE) data in molecular epidemiologic and evolutionary analyses, we determined that S. aureus likely has a primarily clonal population structure and that spa typing can singly index genetic variation with 88% direct concordance with the microarray and can correctly assign isolates to phylogenetic lineages. spa typing performed better than MLEE, PFGE, and coa typing in discriminatory power and in the degree of agreement with the microarray at various phylogenetic depths. This study showed that genetic analysis of the repeat region of protein A comprehensively characterizes both micro- and macrovariation in the primarily clonal population structure of S. aureus.
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Affiliation(s)
- Larry Koreen
- Public Health Research Institute, International Center for Public Health, Graduate School of Biomedical Sciences and New Jersey Medical School, University of Medicine and Dentistry of New Jersey, Newark, New Jersey 07103, USA
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Jonas D, Spitzmüller B, Weist K, Rüden H, Daschner FD. Comparison of PCR-based methods for typing Escherichia coli. Clin Microbiol Infect 2003; 9:823-31. [PMID: 14616703 DOI: 10.1046/j.1469-0691.2003.00661.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To establish a library typing system appropriate for studying cross-transmission of Escherichia coli. METHODS Eighteen epidemiologically unrelated isolates were genotyped by means of pulsed-field gel electrophoresis (PFGE), random amplified polymorphic DNA (RAPD), repetitive (rep) PCR, and fluorescent amplified fragment length polymorphism (AFLP). Fingerprints were analyzed either by Pearson correlation or, in the case of AFLP, by Dice coefficients employing the novel 'uncertain band' software tool from GelCompar II. During a nine-month period, 112 isolates taken from 93 patients hospitalized in five intensive care units were analyzed by use of the two most discriminative PCR typing methods. RESULTS Genotyping by RAPD and rep-PCR revealed insufficient discrimination. Among 18 epidemiologically unrelated strains with 17 different PFGE patterns, IS3 rep-PCR and AFLP distinguished 10 and 18 types, respectively. Comparison of the different methods for analysis of AFLP fingerprints showed that the Dice coefficients, which ignore 'uncertain bands', offered the best concordance with visual interpretation. Consecutive isolates originating from the same patient differed in less than three fragments. CONCLUSIONS AFLP analysis showed the highest discriminative capacity for PCR typing of E. coli isolates. Analysis of fingerprints employing the Dice coefficients proved the most efficient method for an automated software-based retrieval of visually indistinguishable genotypes in an AFLP fingerprint database.
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Affiliation(s)
- D Jonas
- Institute of Environmental Medicine and Hospital Epidemiology, Freiburg University Hospital, Freiburg, Germany.
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