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Naidoo N, Zishiri OT. Comparative genomics analysis and characterization of Shiga toxin-producing Escherichia coli O157:H7 strains reveal virulence genes, resistance genes, prophages and plasmids. BMC Genomics 2023; 24:791. [PMID: 38124028 PMCID: PMC10731853 DOI: 10.1186/s12864-023-09902-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 12/13/2023] [Indexed: 12/23/2023] Open
Abstract
Escherichia coli O157:H7 is a foodborne pathogen that has been linked to global disease outbreaks. These diseases include hemorrhagic colitis and hemolytic uremic syndrome. It is vital to know the features that make this strain pathogenic to understand the development of disease outbreaks. In the current study, a comparative genomic analysis was carried out to determine the presence of structural and functional features of O157:H7 strains obtained from 115 National Center for Biotechnology Information database. These strains of interest were analysed in the following programs: BLAST Ring Image Generator, PlasmidFinder, ResFinder, VirulenceFinder, IslandViewer 4 and PHASTER. Five strains (ECP19-198, ECP19-798, F7508, F8952, H2495) demonstrated a great homology with Sakai because of a few regions missing. Five resistant genes were identified, however, Macrolide-associated resistance gene mdf(A) was commonly found in all genomes. Majority of the strains (97%) were positive for 15 of the virulent genes (espA, espB, espF, espJ, gad, chuA, eae, iss, nleA, nleB, nleC, ompT, tccP, terC and tir). The plasmid analysis demonstrated that the IncF group was the most prevalent in the strains analysed. The prophage and genomic island analysis showed a distribution of bacteriophages and genomic islands respectively. The results indicated that structural and functional features of the many O157:H7 strains differ and may be a result of obtaining mobile genetic elements via horizontal gene transfer. Understanding the evolution of O157:H7 strains pathogenicity in terms of their structural and functional features will enable the development of detection and control of transmission strategies.
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Affiliation(s)
- Natalie Naidoo
- School of Life Sciences, College of Agriculture, Engineering and Sciences, University of KwaZulu-Natal, Private Bag X54001, Durban, 4000, South Africa.
| | - Oliver T Zishiri
- School of Life Sciences, College of Agriculture, Engineering and Sciences, University of KwaZulu-Natal, Private Bag X54001, Durban, 4000, South Africa
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2
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Hoyle DV, Wee BA, Macleod K, Chase-Topping ME, Bease AG, Tongue SC, Gally DL, Delannoy S, Fach P, Pearce MC, Gunn GJ, Holmes A, Allison L. Phylogenetic relationship and virulence composition of Escherichia coli O26:H11 cattle and human strain collections in Scotland; 2002-2020. Front Microbiol 2023; 14:1260422. [PMID: 38029122 PMCID: PMC10657854 DOI: 10.3389/fmicb.2023.1260422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 10/05/2023] [Indexed: 12/01/2023] Open
Abstract
O26 is the commonest non-O157 Shiga toxin (stx)-producing Escherichia coli serogroup reported in human infections worldwide. Ruminants, particularly cattle, are the primary reservoir source for human infection. In this study, we compared the whole genomes and virulence profiles of O26:H11 strains (n = 99) isolated from Scottish cattle with strains from human infections (n = 96) held by the Scottish Escherichia coli O157/STEC Reference Laboratory, isolated between 2002 and 2020. Bovine strains were from two national cross-sectional cattle surveys conducted between 2002-2004 and 2014-2015. A maximum likelihood phylogeny was constructed from a core-genome alignment with the O26:H11 strain 11368 reference genome. Genomes were screened against a panel of 2,710 virulence genes using the Virulence Finder Database. All stx-positive bovine O26:H11 strains belonged to the ST21 lineage and were grouped into three main clades. Bovine and human source strains were interspersed, and the stx subtype was relatively clade-specific. Highly pathogenic stx2a-only ST21 strains were identified in two herds sampled in the second cattle survey and in human clinical infections from 2010 onwards. The closest pairwise distance was 9 single-nucleotide polymorphisms (SNPs) between Scottish bovine and human strains and 69 SNPs between the two cattle surveys. Bovine O26:H11 was compared to public EnteroBase ST29 complex genomes and found to have the greatest commonality with O26:H11 strains from the rest of the UK, followed by France, Italy, and Belgium. Virulence profiles of stx-positive bovine and human strains were similar but more conserved for the stx2a subtype. O26:H11 stx-negative ST29 (n = 17) and ST396 strains (n = 5) were isolated from 19 cattle herds; all were eae-positive, and 10 of these herds yielded strains positive for ehxA, espK, and Z2098, gene markers suggestive of enterohaemorrhagic potential. There was a significant association (p < 0.001) between nucleotide sequence percent identity and stx status for the bacteriophage insertion site genes yecE for stx2 and yehV for stx1. Acquired antimicrobial resistance genes were identified in silico in 12.1% of bovine and 17.7% of human O26:H11 strains, with sul2, tet, aph(3″), and aph(6″) being most common. This study describes the diversity among Scottish bovine O26:H11 strains and investigates their relationship to human STEC infections.
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Affiliation(s)
- Deborah V. Hoyle
- Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Edinburgh, United Kingdom
| | - Bryan A. Wee
- Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Edinburgh, United Kingdom
| | - Kareen Macleod
- Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Edinburgh, United Kingdom
| | - Margo E. Chase-Topping
- Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Edinburgh, United Kingdom
| | - Andrew G. Bease
- Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Edinburgh, United Kingdom
| | - Sue C. Tongue
- Centre for Epidemiology and Planetary Health, Department of Veterinary and Animal Science, North Faculty, Scotland’s Rural College (SRUC), Inverness, United Kingdom
| | - David L. Gally
- Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Edinburgh, United Kingdom
| | - Sabine Delannoy
- Unité ColiPath – Plateforme IdentyPath, Laboratoire de Sécurité des Aliments, Agence Nationale De Sécurité Sanitaire de l’alimentation, de l’environnement et du travail (ANSES), Maisons-Alfort, France
| | - Patrick Fach
- Unité ColiPath – Plateforme IdentyPath, Laboratoire de Sécurité des Aliments, Agence Nationale De Sécurité Sanitaire de l’alimentation, de l’environnement et du travail (ANSES), Maisons-Alfort, France
| | - Michael C. Pearce
- Centre for Epidemiology and Planetary Health, Department of Veterinary and Animal Science, North Faculty, Scotland’s Rural College (SRUC), Inverness, United Kingdom
| | - George J. Gunn
- Centre for Epidemiology and Planetary Health, Department of Veterinary and Animal Science, North Faculty, Scotland’s Rural College (SRUC), Inverness, United Kingdom
| | - Anne Holmes
- Scottish E. coli O157/STEC Reference Laboratory (SERL), Royal Infirmary of Edinburgh, Edinburgh, United Kingdom
| | - Lesley Allison
- Scottish E. coli O157/STEC Reference Laboratory (SERL), Royal Infirmary of Edinburgh, Edinburgh, United Kingdom
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3
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Alotaibi K, Khan AA. Prevalence and Molecular Characterization of Shiga Toxin-Producing Escherichia coli from Food and Clinical Samples. Pathogens 2023; 12:1302. [PMID: 38003767 PMCID: PMC10675443 DOI: 10.3390/pathogens12111302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 10/18/2023] [Accepted: 10/25/2023] [Indexed: 11/26/2023] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) is one of the most prominent food-borne pathogens in humans. The current study aims to detect and to analyze the virulence factors, antibiotic resistance, and plasmid profiles for forty-six STEC strains, isolated from clinical and food strains. Pulsed-field gel electrophoresis (PFGE) was used to determine the genetic relatedness between different serotypes and sources of samples. The clinical samples were found to be resistant to Nb (100%), Tet (100%), Amp (20%), SXT (15%), and Kan (15%) antibiotics. In contrast, the food strains were found to be resistant to Nb (100%), Tet (33%), Amp (16.6%), and SXT (16.6%) antibiotics. The PFGE typing of the forty-six isolates was grouped into more than ten clusters, each with a similarity between 30% and 70%. Most of the isolates were found positive for more than five virulence genes (eae, hlyA, stx1, stx2, stx2f, stx2c, stx2e, stx2, nelB, pagC, sen, toxB, irp, efa, and efa1). All the isolates carried different sizes of the plasmids. The isolates were analyzed for plasmid replicon type by PCR, and 72.5% of the clinical isolates were found to contain X replicon-type plasmid, 50% of the clinical isolates contained FIB replicon-type plasmid, and 17.5% of the clinical isolates contained Y replicon-type plasmid. Three clinical isolates contained both I1 and Hi1 replicon-type plasmid. Only two food isolates contained B/O and W replicon-type plasmid. These results indicate that STEC strains have diverse clonal populations among food and clinical strains that are resistant to several antimicrobials. In conclusion, our findings indicate that food isolates of STEC strains harbor virulence, antimicrobial resistance, plasmid replicon typing determinants like those of other STEC strains from clinical strains. These results suggest that these strains are unique and may contribute to the virulence of the isolates. Therefore, surveillance and characterization of STEC strains can provide useful information about the prevalence of STEC in food and clinical sources. Furthermore, it will help to identify STEC serotypes that are highly pathogenic to humans and may emerge as a threat to public health.
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Affiliation(s)
- Khulud Alotaibi
- Division of Microbiology, National Center for Toxicological Research, United States Food and Drug Administration, Jefferson, AR 72079, USA;
- Department of Biology, University of Arkansas at Little Rock, Little Rock, AR 72205, USA
| | - Ashraf A. Khan
- Division of Microbiology, National Center for Toxicological Research, United States Food and Drug Administration, Jefferson, AR 72079, USA;
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4
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Michelacci V, Montalbano Di Filippo M, Gigliucci F, Arancia S, Chiani P, Minelli F, Roosens NHC, De Keersmaecker SCJ, Bogaerts B, Vanneste K, Morabito S. Population Analysis of O26 Shiga Toxin-Producing Escherichia coli Causing Hemolytic Uremic Syndrome in Italy, 1989–2020, Through Whole Genome Sequencing. Front Cell Infect Microbiol 2022; 12:842508. [PMID: 35223557 PMCID: PMC8864317 DOI: 10.3389/fcimb.2022.842508] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 01/19/2022] [Indexed: 11/13/2022] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) belonging to the O26 serogroup represent an important cause of Hemolitic Uremic Syndrome (HUS) in children worldwide. The localization of STEC virulence genes on mobile genetic elements allowed the emergence of clones showing different assets of this accessory genomic fraction. A novel O26 STEC clone belonging to Sequence Type (ST) 29 and harboring stx2a, ehxA and etpD plasmid-borne genes has emerged and spread in Europe since the mid-1990s, while another ST29 clone positive for stx2d and lacking plasmid-borne virulence genes was recently described as emerging in France. In Italy, O26 has been the most frequently detected STEC serogroup from HUS cases since the late 1990s. In this study we describe the genomic characterization and population structure of 144 O26 STEC strains isolated from human sources in Italy in the period 1989-2020. A total of 89 strains belonged to ST21, 52 to ST29, two to ST396 and one to ST4944. ST29 strains started to be isolated from 1999. 24 strains were shown to harbour stx1a, alone (n=20) or in combination with stx2a (n=4). The majority of the strains (n=118) harbored stx2a genes only and the two ST396 strains harbored stx2d. A Hierarchical Clustering on Principal Components (HCPC) analysis, based on the detection of accessory virulence genes, antimicrobial resistance (AMR) genes and plasmid replicons, classified the strains in seven clusters identified with numbers from 1 to 7, containing two, 13, 39, 63, 16, 10 and one strain, respectively. The majority of the genetic features defining the clusters corresponded to plasmid-borne virulence genes, AMR genes and plasmid replicons, highlighting specific assets of plasmid-borne features associated with different clusters. Core genome Multi Locus Sequence Typing grouped ST21 and ST29 strains in three clades each, with each ST29 clade exactly corresponding to one HCPC cluster. Our results showed high conservation of either the core or the accessory genomic fraction in populations of ST29 O26 STEC, differently from what observed in ST21 strains, suggesting that a different selective pressure could drive the evolution of different populations of these pathogens possibly involving different ecological niches.
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Affiliation(s)
- Valeria Michelacci
- Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore di Sanità, Rome, Italy
- *Correspondence: Valeria Michelacci,
| | | | - Federica Gigliucci
- Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore di Sanità, Rome, Italy
| | - Silvia Arancia
- Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore di Sanità, Rome, Italy
| | - Paola Chiani
- Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore di Sanità, Rome, Italy
| | - Fabio Minelli
- Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore di Sanità, Rome, Italy
| | - Nancy H. C. Roosens
- Sciensano, Biological Health Risks, Transversal Activities in Applied Genomics, Brussels, Belgium
| | | | - Bert Bogaerts
- Sciensano, Biological Health Risks, Transversal Activities in Applied Genomics, Brussels, Belgium
| | - Kevin Vanneste
- Sciensano, Biological Health Risks, Transversal Activities in Applied Genomics, Brussels, Belgium
| | - Stefano Morabito
- Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore di Sanità, Rome, Italy
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5
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Large-Scale Phylogenetic Analysis Reveals a New Genetic Clade among Escherichia coli O26 Strains. Microbiol Spectr 2022; 10:e0252521. [PMID: 35107330 PMCID: PMC8809355 DOI: 10.1128/spectrum.02525-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) O26 is the predominant non-O157 serogroup causing hemolytic uremic syndrome worldwide. Moreover, the serogroup is highly dynamic and harbors several pathogenic clones. Here, we investigated the phylogenetic relationship of STEC O26 at a global level based on 1,367 strains from 20 countries deposited in NCBI and Enterobase databases. The whole-genome-based analysis identified a new genetic clade, called ST29C4. The new clade was unique in terms of multilocus sequence type (ST29), CRISPR (group Ia), and dominant plasmid gene profile (ehxA+/katP-/espP-/etpD-). Moreover, the combination of multiple typing methods (core genome single nucleotide polymorphism [SNP] typing, CRISPR typing, and virulence genes analysis) demonstrated that this new lineage ST29C4 was in the intermediate phylogenetic position between ST29C3 and other non-ST29C3 strains. Besides, we observed that ST29C4 harbored extraintestinal pathogenic E. coli (ExPEC)-related virulence gene (VG), tsh, and STEC-associated VG, stx2a, suggesting the emergence of a hybrid pathogen. The ST29C4 strains also exhibited high similarity in stx2a-prophage and integrase with the O104:H4 strain, further demonstrating its potential risk to human health. Collectively, the large-scale phylogenetic analysis extends the understanding of the clonal structure of O26 strains and provides new insights for O26 strain microevolution. IMPORTANCE Shiga toxin-producing Escherichia coli (STEC) O26 is the second prevalent STEC serogroup only to O157, which can cause a series of diseases ranging from mild diarrhea to life-threatening hemolytic uremic syndrome (HUS). The serogroup is highly diverse and multiple clones are characterized, including ST29C1-C3 and ST21C1-C2. However, the phylogenetic relationship of these clones remains fully unclear. In this study, we revealed a new genetic clade among O26 strains, ST29C4, which was unique in terms of CRISPR, multilocus sequence type (MLST), and plasmid gene profile (PGP). Moreover, the combination of multiple typing methods demonstrated that this new clone was located in the intermediate phylogenetic position between ST29C3 and other non-ST29C3 strains (i.e., ST29C1-C2 and ST21C1-C2). Overall, the large-scale phylogenetic analysis extends our current understanding of O26 microevolution.
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6
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Nakamura K, Murase K, Sato MP, Toyoda A, Itoh T, Mainil JG, Piérard D, Yoshino S, Kimata K, Isobe J, Seto K, Etoh Y, Narimatsu H, Saito S, Yatsuyanagi J, Lee K, Iyoda S, Ohnishi M, Ooka T, Gotoh Y, Ogura Y, Hayashi T. Differential dynamics and impacts of prophages and plasmids on the pangenome and virulence factor repertoires of Shiga toxin-producing Escherichia coli O145:H28. Microb Genom 2020; 6:e000323. [PMID: 31935184 PMCID: PMC7067040 DOI: 10.1099/mgen.0.000323] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Accepted: 12/09/2019] [Indexed: 12/20/2022] Open
Abstract
Phages and plasmids play important roles in bacterial evolution and diversification. Although many draft genomes have been generated, phage and plasmid genomes are usually fragmented, limiting our understanding of their dynamics. Here, we performed a systematic analysis of 239 draft genomes and 7 complete genomes of Shiga toxin (Stx)-producing Escherichia coli O145:H28, the major virulence factors of which are encoded by prophages (PPs) or plasmids. The results indicated that PPs are more stably maintained than plasmids. A set of ancestrally acquired PPs was well conserved, while various PPs, including Stx phages, were acquired by multiple sublineages. In contrast, gains and losses of a wide range of plasmids have frequently occurred across the O145:H28 lineage, and only the virulence plasmid was well conserved. The different dynamics of PPs and plasmids have differentially impacted the pangenome of O145:H28, with high proportions of PP- and plasmid-associated genes in the variably present and rare gene fractions, respectively. The dynamics of PPs and plasmids have also strongly impacted virulence gene repertoires, such as the highly variable distribution of stx genes and the high conservation of a set of type III secretion effectors, which probably represents the core effectors of O145:H28 and the genes on the virulence plasmid in the entire O145:H28 population. These results provide detailed insights into the dynamics of PPs and plasmids, and show the application of genomic analyses using a large set of draft genomes and appropriately selected complete genomes.
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Affiliation(s)
- Keiji Nakamura
- Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Kazunori Murase
- Faculty of Medicine, University of Miyazaki, Miyazaki, Japan
| | - Mitsuhiko P. Sato
- Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Atsushi Toyoda
- Center for Information Biology, National Institute of Genetics, Tokyo, Japan
| | - Takehiko Itoh
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Tokyo, Japan
| | | | | | - Shuji Yoshino
- Miyazaki Prefectural Institute for Public Health and Environment, Miyazaki, Japan
| | | | | | - Kazuko Seto
- Osaka Institute of Public Health, Osaka, Japan
| | - Yoshiki Etoh
- Fukuoka Institute of Health and Environmental Sciences, Fukuoka, Japan
| | | | - Shioko Saito
- Akita Research Center for Public Health and Environment, Akita, Japan
| | - Jun Yatsuyanagi
- Akita Research Center for Public Health and Environment, Akita, Japan
| | - Kenichi Lee
- National Institute of Infectious Diseases, Tokyo, Japan
| | - Sunao Iyoda
- National Institute of Infectious Diseases, Tokyo, Japan
| | | | - Tadasuke Ooka
- Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Yasuhiro Gotoh
- Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Yoshitoshi Ogura
- Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Tetsuya Hayashi
- Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
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Garcillán-Barcia MP, Cuartas-Lanza R, Cuevas A, de la Cruz F. Cis-Acting Relaxases Guarantee Independent Mobilization of MOB Q 4 Plasmids. Front Microbiol 2019; 10:2557. [PMID: 31781067 PMCID: PMC6856555 DOI: 10.3389/fmicb.2019.02557] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Accepted: 10/23/2019] [Indexed: 12/16/2022] Open
Abstract
Plasmids are key vehicles of horizontal gene transfer and contribute greatly to bacterial genome plasticity. In this work, we studied a group of plasmids from enterobacteria that encode phylogenetically related mobilization functions that populate the previously non-described MOBQ4 relaxase family. These plasmids encode two transfer genes: mobA coding for the MOBQ4 relaxase; and mobC, which is non-essential but enhances the plasmid mobilization frequency. The origin of transfer is located between these two divergently transcribed mob genes. We found that MPFI conjugative plasmids were the most efficient helpers for MOBQ4 conjugative dissemination among clinically relevant enterobacteria. While highly similar in their mobilization module, two sub-groups with unrelated replicons (Rep_3 and ColE2) can be distinguished in this plasmid family. These subgroups can stably coexist (are compatible) and transfer independently, despite origin-of-transfer cross-recognition by their relaxases. Specific discrimination among their highly similar oriT sequences is guaranteed by the preferential cis activity of the MOBQ4 relaxases. Such a strategy would be biologically relevant in a scenario of co-residence of non-divergent elements to favor self-dissemination.
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Affiliation(s)
- M Pilar Garcillán-Barcia
- Instituto de Biomedicina y Biotecnología de Cantabria (Universidad de Cantabria - Consejo Superior de Investigaciones Científicas), Santander, Spain
| | - Raquel Cuartas-Lanza
- Instituto de Biomedicina y Biotecnología de Cantabria (Universidad de Cantabria - Consejo Superior de Investigaciones Científicas), Santander, Spain
| | - Ana Cuevas
- Instituto de Biomedicina y Biotecnología de Cantabria (Universidad de Cantabria - Consejo Superior de Investigaciones Científicas), Santander, Spain
| | - Fernando de la Cruz
- Instituto de Biomedicina y Biotecnología de Cantabria (Universidad de Cantabria - Consejo Superior de Investigaciones Científicas), Santander, Spain
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8
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González-Escalona N, Allard MA, Brown EW, Sharma S, Hoffmann M. Nanopore sequencing for fast determination of plasmids, phages, virulence markers, and antimicrobial resistance genes in Shiga toxin-producing Escherichia coli. PLoS One 2019; 14:e0220494. [PMID: 31361781 PMCID: PMC6667211 DOI: 10.1371/journal.pone.0220494] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 07/17/2019] [Indexed: 02/02/2023] Open
Abstract
Whole genome sequencing can provide essential public health information. However, it is now known that widely used short-read methods have the potential to miss some randomly-distributed segments of genomes. This can prevent phages, plasmids, and virulence factors from being detected or properly identified. Here, we compared assemblies of three complete Shiga toxin-producing Escherichia coli (STEC) O26:H11/H- genomes from two different sequence types (ST21 and 29), each acquired using the Nextera XT MiSeq, MinION nanopore-based sequencing, and Pacific Biosciences (PacBio) sequencing. Each closed genome consisted of a single chromosome, approximately 5.7 Mb for CFSAN027343, 5.6 Mb for CFSAN027346, and 5.4 MB for CFSAN027350. However, short-read whole genome sequencing (WGS) using Nextera XT MiSeq failed to identify some virulence genes in plasmids and on the chromosome, both of which were detected using the long-read platforms. Results from long-read MinION and PacBio allowed us to identify differences in plasmid content: a single 88 kb plasmid in CFSAN027343; a 157kb plasmid in CFSAN027350; and two plasmids in CFSAN027346 (one 95 Kb, one 72 Kb). These data enabled rapid characterization of the virulome, detection of antimicrobial genes, and composition/location of Stx phages. Taken together, positive correlations between the two long-read methods for determining plasmids, virulome, antimicrobial resistance genes, and phage composition support MinION sequencing as one accurate and economical option for closing STEC genomes and identifying specific virulence markers.
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Affiliation(s)
- Narjol González-Escalona
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD, United States of America
- * E-mail:
| | - Marc A. Allard
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD, United States of America
| | - Eric W. Brown
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD, United States of America
| | - Shashi Sharma
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD, United States of America
| | - Maria Hoffmann
- Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD, United States of America
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9
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Roy Chowdhury P, McKinnon J, Liu M, Djordjevic SP. Multidrug Resistant Uropathogenic Escherichia coli ST405 With a Novel, Composite IS 26 Transposon in a Unique Chromosomal Location. Front Microbiol 2019; 9:3212. [PMID: 30671039 PMCID: PMC6331395 DOI: 10.3389/fmicb.2018.03212] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 12/11/2018] [Indexed: 11/13/2022] Open
Abstract
Escherichia coli ST405 is an emerging urosepsis pathogen, noted for carriage of blaCTX-M, blaNDM, and a repertoire of virulence genes comparable with O25b:H4-ST131. Extraintestinal and multidrug resistant E. coli ST405 are poorly studied in Australia. Here we determined the genome sequence of a uropathogenic, multiple drug resistant E. coli ST405 (strain 2009-27) from the mid-stream urine of a hospital patient in Sydney, Australia, using a combination of Illumina and SMRT sequencing. The genome of strain 2009-27 assembled into two unitigs; a chromosome comprising 5,287,472 bp and an IncB/O plasmid, pSDJ2009-27, of 89,176 bp. In silico and phenotypic analyses showed that strain 2009-27 is a serotype O102:H6, phylogroup D ST405 resistant to ampicillin, azithromycin, kanamycin, streptomycin, trimethoprim, and sulphafurazole. The genes encoding resistance to these antibiotics reside within a novel, mobile IS26-flanked transposon, identified here as Tn6242, in the chromosomal gene yjdA. Tn6242 comprises four modules that each carries resistance genes flanked by IS26, including a class 1 integron with dfrA17 and aadA5 gene cassettes, a variant of Tn6029, and mphA. We exploited unique genetic signatures located within Tn6242 to identify strains of ST405 from Danish patients that also carry the transposon in the same chromosomal location. The acquisition of Tn6242 into yjdA in ST405 is significant because it (i) is vertically inheritable; (ii) represents a reservoir of resistance genes that can transpose onto resident/circulating plasmids; and (iii) is a site for the capture of further IS26-associated resistance gene cargo.
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Affiliation(s)
- Piklu Roy Chowdhury
- The ithree Institute, University of Technology Sydney, Ultimo, NSW, Australia.,NSW Department of Primary Industries, Elizabeth Macarthur Agricultural Institute, Macarthur, NSW, Australia
| | - Jessica McKinnon
- The ithree Institute, University of Technology Sydney, Ultimo, NSW, Australia
| | - Michael Liu
- The ithree Institute, University of Technology Sydney, Ultimo, NSW, Australia
| | - Steven P Djordjevic
- The ithree Institute, University of Technology Sydney, Ultimo, NSW, Australia
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10
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Usein CR, Ciontea AS, Militaru CM, Condei M, Dinu S, Oprea M, Cristea D, Michelacci V, Scavia G, Zota LC, Zaharia A, Morabito S. Molecular characterisation of human Shiga toxin-producing Escherichia coli O26 strains: results of an outbreak investigation, Romania, February to August 2016. ACTA ACUST UNITED AC 2018; 22. [PMID: 29183554 PMCID: PMC5710660 DOI: 10.2807/1560-7917.es.2017.22.47.17-00148] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
At the beginning of 2016, an increase in paediatric haemolytic uremic syndrome (HUS) cases was observed in Romania. The microbiological investigations allowed isolation of Shiga toxin-producing Escherichia coli (STEC) O26 as the causative agent from most cases. Methods: An enhanced national surveillance of HUS and severe diarrhoea was established across the country following the identification of the first cases and was carried out until August 2016. A total of 15 strains were isolated from 10 HUS and five diarrhoea cases. Strains were characterised by virulence markers (i.e. stx type/subtype, eae, ehxA genes), phylogroup, genetic relatedness and clonality using PCR-based assays, PFGE and multilocus sequence typing (MLST). The first six strains were further characterised by whole genome sequencing (WGS). Results: Five PCR-defined genotypes were distinguished. All strains from HUS cases harboured stx2a and eae, with or without stx1a, while strains from diarrhoea cases carried exclusively stx1a and eae genes. PFGE resolved strains into multiple pulsotypes, compatible with a certain geographic segregation of the cases, and strains were assigned to phylogroup B1 and sequence type (ST) 21. WGS confirmed the results of conventional molecular methods, brought evidence of O26:H11 serotype, and complemented the virulence profiles. Discussion/conclusion: This first description of STEC O26 strains from cases in Romania showed that the isolates belonged to a diverse population. The virulence content of most strains highlighted a high risk for severe outcome in infected patients. Improving the national surveillance strategy for STEC infections in Romania needs to be further considered.
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Affiliation(s)
- Codruţa-Romaniţa Usein
- Carol Davila University of Medicine and Pharmacy, Bucharest, Romania.,Cantacuzino National Institute of Research, Bucharest, Romania
| | | | | | - Maria Condei
- Cantacuzino National Institute of Research, Bucharest, Romania
| | - Sorin Dinu
- Cantacuzino National Institute of Research, Bucharest, Romania
| | - Mihaela Oprea
- Cantacuzino National Institute of Research, Bucharest, Romania
| | - Daniela Cristea
- Cantacuzino National Institute of Research, Bucharest, Romania
| | - Valeria Michelacci
- Food Safety, Nutrition and Veterinary Public Health Department, Istituto Superiore di Sanità, Rome, Italy
| | - Gaia Scavia
- Food Safety, Nutrition and Veterinary Public Health Department, Istituto Superiore di Sanità, Rome, Italy
| | - Lavinia Cipriana Zota
- National Center for Surveillance and Control of Communicable Diseases, National Institute of Public Health, Bucharest, Romania
| | - Alina Zaharia
- National Center for Surveillance and Control of Communicable Diseases, National Institute of Public Health, Bucharest, Romania
| | - Stefano Morabito
- Food Safety, Nutrition and Veterinary Public Health Department, Istituto Superiore di Sanità, Rome, Italy
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11
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Hernandez-Flores JL, Pérez JC, Gutiérrez CS, Hernández AC, Alonso GS, Hernández SP, Gómez SR, Fernández F, Loske AM, Guillén JC. pMEX01, a 70kb plasmid isolated from Escherichia coli that confers resistance to multiple β-lactam antibiotics. Braz J Microbiol 2018; 49:569-574. [PMID: 29449172 PMCID: PMC6066732 DOI: 10.1016/j.bjm.2017.11.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 07/27/2017] [Accepted: 11/07/2017] [Indexed: 11/25/2022] Open
Abstract
Multidrug-resistant microorganisms are of great concern to public health. Genetic mobile elements, such as plasmids, are among the most relevant mechanisms by which bacteria achieve this resistance. We obtained an Escherichia coli strain CM6, isolated from cattle presenting severe diarrheic symptoms in the State of Querétaro, Mexico. It was found to contain a 70 kb plasmid (pMEX01) with a high similarity to the pHK01-like plasmids that were previously identified and described in Hong Kong. Analysis of the pMEX01 sequence revealed the presence of a blaCTX-M-14 gene, which is responsible for conferring resistance to multiple β-lactam antibiotics. Several genes putatively involved in the conjugative transfer were also identified on the plasmid. The strain CM6 is of high epidemiological concern because it not only displays resistance to multiple β-lactam antibiotics but also to other kinds of antibiotics.
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Affiliation(s)
- Jose Luis Hernandez-Flores
- Unidad Irapuato, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Departamento de Ingeniería Genética, Irapuato, Guanajuato, Mexico
| | | | | | | | - Gerardo Soto Alonso
- Universidad Autónoma de Querétaro, Facultad de Ciencias Naturales, Querétaro, Mexico
| | | | | | - Francisco Fernández
- Universidad Nacional Autónoma de México, Centro de Física Aplicada y Tecnología Avanzada, Querétaro, Mexico
| | - Achim M Loske
- Universidad Nacional Autónoma de México, Centro de Física Aplicada y Tecnología Avanzada, Querétaro, Mexico.
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12
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Flórez AB, Vázquez L, Mayo B. A Functional Metagenomic Analysis of Tetracycline Resistance in Cheese Bacteria. Front Microbiol 2017; 8:907. [PMID: 28596758 PMCID: PMC5442184 DOI: 10.3389/fmicb.2017.00907] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 05/04/2017] [Indexed: 11/13/2022] Open
Abstract
Metagenomic techniques have been successfully used to monitor antibiotic resistance genes in environmental, animal and human ecosystems. However, despite the claim that the food chain plays a key role in the spread of antibiotic resistance, metagenomic analysis has scarcely been used to investigate food systems. The present work reports a functional metagenomic analysis of the prevalence and evolution of tetracycline resistance determinants in a raw-milk, blue-veined cheese during manufacturing and ripening. For this, the same cheese batch was sampled and analyzed on days 3 and 60 of manufacture. Samples were diluted and grown in the presence of tetracycline on plate count milk agar (PCMA) (non-selective) and de Man Rogosa and Sharpe (MRS) agar (selective for lactic acid bacteria, LAB). DNA from the cultured bacteria was then isolated and used to construct four fosmid libraries, named after the medium and sampling time: PCMA-3D, PCMA-60D, MRS-3D, and MRS-60D. Clones in the libraries were subjected to restriction enzyme analysis, PCR amplification, and sequencing. Among the 300 fosmid clones analyzed, 268 different EcoRI restriction profiles were encountered. Sequence homology of their extremes clustered the clones into 47 groups. Representative clones of all groups were then screened for the presence of tetracycline resistance genes by PCR, targeting well-recognized genes coding for ribosomal protection proteins and efflux pumps. A single tetracycline resistance gene was detected in each of the clones, with four such resistance genes identified in total: tet(A), tet(L), tet(M), and tet(S). tet(A) was the only gene identified in the PCMA-3D library, and tet(L) the only one identified in the PCMA-60D and MRS-60D libraries. tet(M) and tet(S) were both detected in the MRS-3D library and in similar numbers. Six representative clones of the libraries were sequenced and analyzed. Long segments of all clones but one showed extensive homology to plasmids from Gram-positive and Gram-negative bacteria. tet(A) was found within a sequence showing strong similarity to plasmids pMAK2 and pO26-Vir from Salmonella enterica and Escherichia coli, respectively. All other genes were embedded in, or near to, sequences homologous to those of LAB species. These findings strongly suggest an evolution of tetracycline resistance gene types during cheese ripening, which might reflect the succession of the microbial populations. The location of the tetracycline resistance genes in plasmids, surrounded or directly flanked by open reading frames encoding transposases, invertases or mobilization proteins, suggests they might have a strong capacity for transference. Raw-milk cheeses should therefore be considered reservoirs of tetracycline resistance genes that might be horizontally transferred.
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Affiliation(s)
- Ana B Flórez
- Departamento de Microbiología y Bioquímica, Instituto de Productos Lácteos de Asturias - Consejo Superior de Investigaciones Científicas, IPLA - CSICAsturias, Spain
| | - Lucía Vázquez
- Departamento de Microbiología y Bioquímica, Instituto de Productos Lácteos de Asturias - Consejo Superior de Investigaciones Científicas, IPLA - CSICAsturias, Spain
| | - Baltasar Mayo
- Departamento de Microbiología y Bioquímica, Instituto de Productos Lácteos de Asturias - Consejo Superior de Investigaciones Científicas, IPLA - CSICAsturias, Spain
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13
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Monteiro R, Ageorges V, Rojas-Lopez M, Schmidt H, Weiss A, Bertin Y, Forano E, Jubelin G, Henderson IR, Livrelli V, Gobert AP, Rosini R, Soriani M, Desvaux M. A secretome view of colonisation factors in Shiga toxin-encodingEscherichia coli(STEC): from enterohaemorrhagicE. coli(EHEC) to related enteropathotypes. FEMS Microbiol Lett 2016; 363:fnw179. [DOI: 10.1093/femsle/fnw179] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/18/2016] [Indexed: 12/25/2022] Open
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14
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Vieira MA, Dos Santos LF, Dias RCB, Camargo CH, Pinheiro SRS, Gomes TAT, Hernandes RT. Atypical enteropathogenic Escherichia coli as aetiologic agents of sporadic and outbreak-associated diarrhoea in Brazil. J Med Microbiol 2016; 65:998-1006. [PMID: 27412254 DOI: 10.1099/jmm.0.000313] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Enteropathogenic Escherichia coli (EPEC) are important agents of diarrhoea in industrialized as well as developing countries, such as Brazil. The hallmark of EPEC pathogenesis is the establishment of attaching and effacing lesions in enterocytes, in which pedestal-like structures are formed underneath adherent bacteria. EPEC are divided into two subgroups, typical (tEPEC) and atypical (aEPEC), based on the presence of the EPEC adherence factor plasmid in tEPEC and its absence in aEPEC. This study was designed to characterize 82 aEPEC isolates obtained from stool samples of diarrhoeic patients during 2012 and 2013 in Brazil. The majority of the aEPEC were assigned to the phylo-group B1 (48.8 %), and intimin subtypes θ (20.7 %), β1 (9.7 %) and λ (9.7 %) were the most prevalent among the isolates. The nleB and nleE genes were concomitantly detected in 32.9 % of the isolates, demonstrating the occurrence of the pathogenicity island O122 among them. The O157-plasmid genes (ehxA and/or espP) were detected in 7.3 % of the isolates, suggesting that some aEPEC could be derived from Shiga-toxin-producing E. coli that lost the stx genes while trafficking in the host. PFGE of 14 aEPEC of serotypes O2 : H16, O33 : H34, O39 : H9, O108 : H- and ONT : H19 isolated from five distinct outbreaks showed serotype-specific PFGE clusters, indicating a high degree of similarity among the isolates from the same event, thus highlighting these serotypes as potential aetiologic agents of diarrhoeal outbreaks in Brazil.
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Affiliation(s)
- Melissa A Vieira
- Departamento de Microbiologia e Imunologia, Instituto de Biociências, Universidade Estadual Paulista 'Júlio de Mesquita Filho' (UNESP), Botucatu, SP, Brazil
| | - Luís F Dos Santos
- Centro de Bacteriologia, Instituto Adolfo Lutz (IAL), São Paulo, SP, Brazil
| | - Regiane C B Dias
- Departamento de Microbiologia e Imunologia, Instituto de Biociências, Universidade Estadual Paulista 'Júlio de Mesquita Filho' (UNESP), Botucatu, SP, Brazil
| | - Carlos H Camargo
- Centro de Bacteriologia, Instituto Adolfo Lutz (IAL), São Paulo, SP, Brazil
| | | | - Tânia A T Gomes
- Departamento de Microbiologia, Imunologia e Parasitologia da Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil
| | - Rodrigo T Hernandes
- Departamento de Microbiologia e Imunologia, Instituto de Biociências, Universidade Estadual Paulista 'Júlio de Mesquita Filho' (UNESP), Botucatu, SP, Brazil
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15
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Rusconi B, Sanjar F, Koenig SSK, Mammel MK, Tarr PI, Eppinger M. Whole Genome Sequencing for Genomics-Guided Investigations of Escherichia coli O157:H7 Outbreaks. Front Microbiol 2016; 7:985. [PMID: 27446025 PMCID: PMC4928038 DOI: 10.3389/fmicb.2016.00985] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Accepted: 06/08/2016] [Indexed: 01/29/2023] Open
Abstract
Multi isolate whole genome sequencing (WGS) and typing for outbreak investigations has become a reality in the post-genomics era. We applied this technology to strains from Escherichia coli O157:H7 outbreaks. These include isolates from seven North America outbreaks, as well as multiple isolates from the same patient and from different infected individuals in the same household. Customized high-resolution bioinformatics sequence typing strategies were developed to assess the core genome and mobilome plasticity. Sequence typing was performed using an in-house single nucleotide polymorphism (SNP) discovery and validation pipeline. Discriminatory power becomes of particular importance for the investigation of isolates from outbreaks in which macrogenomic techniques such as pulse-field gel electrophoresis or multiple locus variable number tandem repeat analysis do not differentiate closely related organisms. We also characterized differences in the phage inventory, allowing us to identify plasticity among outbreak strains that is not detectable at the core genome level. Our comprehensive analysis of the mobilome identified multiple plasmids that have not previously been associated with this lineage. Applied phylogenomics approaches provide strong molecular evidence for exceptionally little heterogeneity of strains within outbreaks and demonstrate the value of intra-cluster comparisons, rather than basing the analysis on archetypal reference strains. Next generation sequencing and whole genome typing strategies provide the technological foundation for genomic epidemiology outbreak investigation utilizing its significantly higher sample throughput, cost efficiency, and phylogenetic relatedness accuracy. These phylogenomics approaches have major public health relevance in translating information from the sequence-based survey to support timely and informed countermeasures. Polymorphisms identified in this work offer robust phylogenetic signals that index both short- and long-term evolution and can complement currently employed typing schemes for outbreak ex- and inclusion, diagnostics, surveillance, and forensic studies.
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Affiliation(s)
- Brigida Rusconi
- South Texas Center for Emerging Infectious Diseases, University of Texas at San AntonioSan Antonio, TX, USA; Department of Biology, University of Texas at San AntonioSan Antonio, TX, USA
| | - Fatemeh Sanjar
- South Texas Center for Emerging Infectious Diseases, University of Texas at San AntonioSan Antonio, TX, USA; Department of Biology, University of Texas at San AntonioSan Antonio, TX, USA
| | - Sara S K Koenig
- South Texas Center for Emerging Infectious Diseases, University of Texas at San AntonioSan Antonio, TX, USA; Department of Biology, University of Texas at San AntonioSan Antonio, TX, USA
| | - Mark K Mammel
- Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration Laurel, MD, USA
| | - Phillip I Tarr
- Department of Pediatrics, Washington University School of Medicine St. Louis, MO, USA
| | - Mark Eppinger
- South Texas Center for Emerging Infectious Diseases, University of Texas at San AntonioSan Antonio, TX, USA; Department of Biology, University of Texas at San AntonioSan Antonio, TX, USA
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16
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Virulence Gene Profiles and Clonal Relationships of Escherichia coli O26:H11 Isolates from Feedlot Cattle as Determined by Whole-Genome Sequencing. Appl Environ Microbiol 2016; 82:3900-3912. [PMID: 27107118 DOI: 10.1128/aem.00498-16] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 04/15/2016] [Indexed: 12/18/2022] Open
Abstract
UNLABELLED Escherichia coli O26 is the second most important enterohemorrhagic E. coli (EHEC) serogroup worldwide. Serogroup O26 strains are categorized mainly into two groups: enteropathogenic (EPEC) O26, carrying a locus of enterocyte effacement (LEE) and mostly causing mild diarrhea, and Shiga-toxigenic (STEC) O26, which carries the Shiga toxin (STX) gene (stx), responsible for more severe outcomes. stx-negative O26 strains can be further split into two groups. One O26 group differs significantly from O26 EHEC, while the other O26 EHEC-like group shows all the characteristics of EHEC O26 except production of STX. In order to determine the different populations of O26 E. coli present in U.S. cattle, we sequenced 42 O26:H11 strains isolated from feedlot cattle and compared them to 37 O26:H11 genomes available in GenBank. Phylogenetic analysis by whole-genome multilocus sequence typing (wgMLST) showed that O26:H11/H(-) strains in U.S. cattle were highly diverse. Most strains were sequence type 29 (ST29). By wgMLST, two clear lineages could be distinguished among cattle strains. Lineage 1 consisted of O26:H11 EHEC-like strains (ST29) (4 strains) and O26:H11 EHEC strains (ST21) (2 strains), and lineage 2 (36 strains) consisted of O26:H11 EPEC strains (ST29). Overall, our analysis showed U.S. cattle carried pathogenic (ST21; stx1 (+) ehxA(+) toxB(+)) and also potentially pathogenic (ST29; ehxA(+) toxB(+)) O26:H11 E. coli strains. Furthermore, in silico analysis showed that 70% of the cattle strains carried at least one antimicrobial resistance gene. Our results showed that whole-genome sequence analysis is a robust and valid approach to identify and genetically characterize E. coli O26:H11, which is of importance for food safety and public health. IMPORTANCE Escherichia coli O26 is the second most important type of enterohemorrhagic E. coli (EHEC) worldwide. Serogroup O26 strains are categorized into two groups: enteropathogenic (EPEC) carrying LEE, causing mild diarrhea, and Shiga toxigenic (STEC) carrying the stx gene, responsible for more severe outcomes. However, there are currently problems in distinguishing one group from the other. Furthermore, several O26 stx-negative strains are consistently misidentified as either EHEC-like or EPEC. The use of whole-genome sequence (WGS) analysis of O26 strains from cattle in the United States (i) allowed identification of O26 strains present in U.S. cattle, (ii) determined O26 strain diversity, (iii) solved the misidentification problem, and (iv) screened for the presence of antimicrobial resistance and virulence genes in the strains. This study provided a framework showing how to easily and rapidly use WGS information to identify and genetically characterize E. coli O26:H11, which is important for food safety and public health.
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17
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Losada L, DebRoy C, Radune D, Kim M, Sanka R, Brinkac L, Kariyawasam S, Shelton D, Fratamico PM, Kapur V, Feng PCH. Whole genome sequencing of diverse Shiga toxin-producing and non-producing Escherichia coli strains reveals a variety of virulence and novel antibiotic resistance plasmids. Plasmid 2015; 83:8-11. [PMID: 26746359 DOI: 10.1016/j.plasmid.2015.12.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 12/21/2015] [Accepted: 12/29/2015] [Indexed: 01/20/2023]
Abstract
The genomes of a diverse set of Escherichia coli, including many Shiga toxin-producing strains of various serotypes were determined. A total of 39 plasmids were identified among these strains, and many carried virulence or putative virulence genes of Shiga toxin-producing E. coli strains, virulence genes for other pathogenic E. coli groups, and some had combinations of these genes. Among the novel plasmids identified were eight that carried resistance genes to aminoglycosides, carbapenems, penicillins, cephalosporins, chloramphenicol, dihydrofolate reductase inhibitors, sulfonamides, tetracyclines and resistance to heavy metals. Two of the plasmids carried six of these resistance genes and two novel IncHI2 plasmids were also identified. The results of this study showed that plasmids carrying diverse resistance and virulence genes of various pathogenic E. coli groups can be found in E. coli strains and serotypes regardless of the isolate's source and therefore, is consistent with the premise that these mobile elements carrying these traits may be broadly disseminated among E. coli.
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Affiliation(s)
| | - Chitrita DebRoy
- Department of Veterinary and Biomedical Sciences, Pennsylvania State University, University Park, PA, USA
| | | | - Maria Kim
- J. Craig Venter Institute, Rockville, MD, USA
| | - Ravi Sanka
- J. Craig Venter Institute, Rockville, MD, USA
| | | | - Subhashinie Kariyawasam
- Department of Veterinary and Biomedical Sciences, Pennsylvania State University, University Park, PA, USA
| | - Daniel Shelton
- Environmental Microbial and Food Safety Laboratory, Agricultural Research Service, USDA, Beltsville, MD, USA
| | - Pina M Fratamico
- Eastern Regional Research Center, Agricultural Research Service, USDA, Wyndmoor, PA, USA
| | - Vivek Kapur
- Department of Veterinary and Biomedical Sciences, Pennsylvania State University, University Park, PA, USA
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18
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Yan X, Fratamico PM, Bono JL, Baranzoni GM, Chen CY. Genome sequencing and comparative genomics provides insights on the evolutionary dynamics and pathogenic potential of different H-serotypes of Shiga toxin-producing Escherichia coli O104. BMC Microbiol 2015; 15:83. [PMID: 25887577 PMCID: PMC4393859 DOI: 10.1186/s12866-015-0413-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 03/12/2015] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Various H-serotypes of the Shiga toxin-producing Escherichia coli (STEC) O104, including H4, H7, H21, and H¯, have been associated with sporadic cases of illness and have caused food-borne outbreaks globally. In the U.S., STEC O104:H21 caused an outbreak associated with milk in 1994. However, there is little known on the evolutionary origins of STEC O104 strains, and how genotypic diversity contributes to pathogenic potential of various O104 H-antigen serotypes isolated from different ecological niches and/or geographical regions. RESULTS Two STEC O104:H21 (milk outbreak strain) and O104:H7 (cattle isolate) strains were shot-gun sequenced, and the genomes were closed. The intimin (eae) gene, involved in the attaching-effacing phenotype of diarrheagenic E. coli, was not found in either strain. Examining various O104 genome sequences, we found that two "complete" left and right end portions of the locus of enterocyte effacement (LEE) pathogenicity island were present in 13 O104 strains; however, the central portion of LEE was missing, where the eae gene is located. In O104:H4 strains, the missing central portion of the LEE locus was replaced by a pathogenicity island carrying the aidA (adhesin involved in diffuse adherence) gene and antibiotic resistance genes commonly carried on plasmids. Enteroaggregative E. coli-specific virulence genes and European outbreak O104:H4-specific stx2-encoding Escherichia P13374 or Escherichia TL-2011c bacteriophages were missing in some of the O104:H4 genome sequences available from public databases. Most of the genomic variations in the strains examined were due to the presence of different mobile genetic elements, including prophages and genomic island regions. The presence of plasmids carrying virulence-associated genes may play a role in the pathogenic potential of O104 strains. CONCLUSIONS The two strains sequenced in this study (O104:H21 and O104:H7) are genetically more similar to each other than to the O104:H4 strains that caused an outbreak in Germany in 2011 and strains found in Central Africa. A hypothesis on strain evolution and pathogenic potential of various H-serotypes of E. coli O104 strains is proposed.
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Affiliation(s)
- Xianghe Yan
- USDA, Agricultural Research Service, Eastern Regional Research Center, 600 E. Mermaid Lane, 19038, Wyndmoor, PA, USA.
- U.S. Department of Agriculture, Eastern Regional Research Center, Agricultural Research Service, 600 East Mermaid Lane, 19038, Wyndmoor, PA, USA.
| | - Pina M Fratamico
- USDA, Agricultural Research Service, Eastern Regional Research Center, 600 E. Mermaid Lane, 19038, Wyndmoor, PA, USA.
| | - James L Bono
- USDA, Agricultural Research Service, Meat Animal Research Center, Clay Center, NE, 68933, USA.
| | - Gian Marco Baranzoni
- USDA, Agricultural Research Service, Eastern Regional Research Center, 600 E. Mermaid Lane, 19038, Wyndmoor, PA, USA.
| | - Chin-Yi Chen
- USDA, Agricultural Research Service, Eastern Regional Research Center, 600 E. Mermaid Lane, 19038, Wyndmoor, PA, USA.
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Hemolysin of enterohemorrhagic Escherichia coli: Structure, transport, biological activity and putative role in virulence. Int J Med Microbiol 2014; 304:521-9. [DOI: 10.1016/j.ijmm.2014.05.005] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Revised: 05/09/2014] [Accepted: 05/11/2014] [Indexed: 11/19/2022] Open
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20
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Identification of two allelic variants of toxB gene and investigation of their distribution among Verocytotoxin-producing Escherichia coli. Int J Med Microbiol 2014; 304:730-4. [DOI: 10.1016/j.ijmm.2014.05.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Revised: 05/12/2014] [Accepted: 05/21/2014] [Indexed: 11/19/2022] Open
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21
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Croxen MA, Law RJ, Scholz R, Keeney KM, Wlodarska M, Finlay BB. Recent advances in understanding enteric pathogenic Escherichia coli. Clin Microbiol Rev 2013; 26:822-80. [PMID: 24092857 PMCID: PMC3811233 DOI: 10.1128/cmr.00022-13] [Citation(s) in RCA: 817] [Impact Index Per Article: 74.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Although Escherichia coli can be an innocuous resident of the gastrointestinal tract, it also has the pathogenic capacity to cause significant diarrheal and extraintestinal diseases. Pathogenic variants of E. coli (pathovars or pathotypes) cause much morbidity and mortality worldwide. Consequently, pathogenic E. coli is widely studied in humans, animals, food, and the environment. While there are many common features that these pathotypes employ to colonize the intestinal mucosa and cause disease, the course, onset, and complications vary significantly. Outbreaks are common in developed and developing countries, and they sometimes have fatal consequences. Many of these pathotypes are a major public health concern as they have low infectious doses and are transmitted through ubiquitous mediums, including food and water. The seriousness of pathogenic E. coli is exemplified by dedicated national and international surveillance programs that monitor and track outbreaks; unfortunately, this surveillance is often lacking in developing countries. While not all pathotypes carry the same public health profile, they all carry an enormous potential to cause disease and continue to present challenges to human health. This comprehensive review highlights recent advances in our understanding of the intestinal pathotypes of E. coli.
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22
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Weiss A, Brockmeyer J. Prevalence, biogenesis, and functionality of the serine protease autotransporter EspP. Toxins (Basel) 2012; 5:25-48. [PMID: 23274272 PMCID: PMC3564066 DOI: 10.3390/toxins5010025] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Revised: 12/18/2012] [Accepted: 12/21/2012] [Indexed: 11/24/2022] Open
Abstract
Enterohemorrhagic E. coli (EHEC) causes severe diseases in humans worldwide. One of its virulence factors is EspP, which belongs to the serine protease autotransporters of Enterobacteriaceae (SPATE) family. In this review we recapitulate the current data on prevalence, biogenesis, structural properties and functionality. EspP has been used to investigate mechanistic details of autotransport, and recent studies indicate that this transport mechanism is not autonomous but rather dependent on additional factors. Currently, five subtypes have been identified (EspPα-EspPε), with EspPα being associated with highly virulent EHEC serotypes and isolates from patients with severe disease. EspPα has been shown to degrade major proteins of the complement cascade, namely C3 and C5 and probably interferes with hemostasis by cleavage of coagulation factor V. Furthermore, EspPα is believed to contribute to biofilm formation perhaps by polymerization to rope-like structures. Together with the proteolytic activity, EspPα might ameliorate host colonization and interfere with host response.
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Affiliation(s)
- André Weiss
- Institute of Food Chemistry, Corrensstraße 45, Münster 48149, Germany.
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Ennis C, McDowell D, Bolton DJ. The prevalence, distribution and characterization of Shiga toxin-producing Escherichia coli (STEC) serotypes and virulotypes from a cluster of bovine farms. J Appl Microbiol 2012; 113:1238-48. [PMID: 22862826 DOI: 10.1111/j.1365-2672.2012.05421.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Revised: 07/23/2012] [Accepted: 07/31/2012] [Indexed: 12/23/2022]
Abstract
AIMS To assess the prevalence of Shiga toxin-producing Escherichia coli (STEC) on a cluster of twelve beef farms in the north-east of Ireland. METHODS AND RESULTS Samples were screened for stx1 and stx2 using PCR. Positive samples were enriched in mTSB and STEC O157 isolated using immunomagnetic separation. Enrichment cultures were plated onto TBX agar to isolate non-O157 STEC. All isolates were serotyped and examined for a range of virulence genes and their antibiotic resistance phenotype determined. Eighty-four isolates of 33 different serotypes were cultured from the 13·7% of samples that were stx positive. The most prevalent serotype was O157:H7, the most common Shiga toxin was stx(2) , and a variety of virulence factor combinations was observed. O-:H-, O26:H11, O76:H34, O157:H7, O157:H16 and OX18:H+ also carried eaeA and hlyA genes. Twenty-nine per cent of strains were resistant to at least one antibiotic, 48% of which had multiple drug resistance (MDR) with O2:H32 displaying resistance to five antibiotics. CONCLUSIONS The ubiquitous nature of STEC on beef farms, the detection of stx(+) eaeA(+) hlyA(+) in the serotypes O-:H-, O157:H16 and OX18:H+ in addition to O157:H7 and O26:H11 and the widespread distribution of antibiotic resistance are of public health concern as new virulent STEC strains are emerging. SIGNIFICANCE AND IMPACT OF THE STUDY This study found no relationship between serotype and antibiotic resistance, therefore negating efforts to isolate serotypes using specific antibiotic supplemented media. The data presented provide further evidence of the emergence of new STEC virulotypes of potential public health significance.
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Affiliation(s)
- C Ennis
- Department of Food Safety, Teagasc Food Research Centre, Ashtown, Dublin, Ireland
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Yan X, Fratamico PM, Needleman DS, Bayles DO. DNA sequence and analysis of a 90.1-kb plasmid in Shiga toxin-producing Escherichia coli (STEC) O145:NM 83-75. Plasmid 2012; 68:25-32. [DOI: 10.1016/j.plasmid.2012.02.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Revised: 02/09/2012] [Accepted: 02/12/2012] [Indexed: 10/28/2022]
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Serotypes and virulence profiles of non-O157 Shiga toxin-producing Escherichia coli isolates from bovine farms. Appl Environ Microbiol 2011; 77:8662-8. [PMID: 22003024 DOI: 10.1128/aem.06190-11] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Non-O157 Shiga toxin-producing Escherichia coli (STEC) strains are clinically significant food-borne pathogens. However, there is a dearth of information on serotype prevalence and virulence gene distribution, data essential for the development of public health protection monitoring and control activities for the meat and dairy industries. Thus, the objective of this study was to examine the prevalence of non-O157 STEC on beef and dairy farms and to characterize the isolates in terms of serotype and virulence markers. Bovine fecal samples (n = 1,200) and farm soil samples (n = 600) were collected from 20 farms throughout Ireland over a 12-month period. Shiga toxin-positive samples were cultured and colonies examined for the presence of stx₁ and/or stx₂ genes by PCR. Positive isolates were serotyped and examined for a range of virulence factors, including eaeA, hlyA, tir, espA, espB, katP, espP, etpD, saa, sab, toxB, iha, lpfA(O157/OI-141), lpfA(O113), and lpfA(O157/OI-154). Shiga toxin and intimin genes were further examined for known variants. Significant numbers of fecal (40%) and soil (27%) samples were stx positive, with a surge observed in late summer-early autumn. One hundred seven STEC isolates were recovered, representing 17 serotypes. O26:H11 and O145:H28 were the most clinically significant, with O113:H4 being the most frequently isolated. However, O2:H27, O13/O15:H2, and ONT:H27 also carried stx₁ and/or stx₂ and eaeA and may be emerging pathogens.
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Melton-Celsa A, Mohawk K, Teel L, O’Brien A. Pathogenesis of Shiga-Toxin Producing Escherichia coli. Curr Top Microbiol Immunol 2011; 357:67-103. [DOI: 10.1007/82_2011_176] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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