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Lupolova N, Chalka A, Gally DL. Predicting Host Association for Shiga Toxin-Producing E. coli Serogroups by Machine Learning. Methods Mol Biol 2021; 2291:99-117. [PMID: 33704750 DOI: 10.1007/978-1-0716-1339-9_4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Escherichia coli is a species of bacteria that can be present in a wide variety of mammalian hosts and potentially soil environments. E. coli has an open genome and can show considerable diversity in gene content between isolates. It is a reasonable assumption that gene content reflects evolution of strains in particular host environments and therefore can be used to predict the host most likely to be the source of an isolate. An extrapolation of this argument is that strains may also have gene content that favors success in multiple hosts and so the possibility of successful transmission from one host to another, for example, from cattle to human, can also be predicted based on gene content. In this methods chapter, we consider the issue of Shiga toxin (Stx)-producing E. coli (STEC) strains that are present in ruminants as the main host reservoir and for which we know that a subset causes life-threatening infections in humans. We show how the genome sequences of E. coli isolated from both cattle and humans can be used to build a classifier to predict human and cattle host association and how this can be applied to score key STEC serotypes known to be associated with human infection. With the example dataset used, serogroups O157, O26, and O111 show the highest, and O103 and O145 the lowest, predictions for human association. The long-term ambition is to combine such machine learning predictions with phylogeny to predict the zoonotic threat of an isolate based on its whole genome sequence (WGS).
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Affiliation(s)
- Nadejda Lupolova
- Division of Infection and Immunity, The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, UK
| | - Antonia Chalka
- Division of Infection and Immunity, The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, UK
| | - David L Gally
- Division of Infection and Immunity, The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, UK.
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Ludwig JB, Shi X, Shridhar PB, Roberts EL, DebRoy C, Phebus RK, Bai J, Nagaraja TG. Multiplex PCR Assays for the Detection of One Hundred and Thirty Seven Serogroups of Shiga Toxin-Producing Escherichia coli Associated With Cattle. Front Cell Infect Microbiol 2020; 10:378. [PMID: 32850480 PMCID: PMC7403468 DOI: 10.3389/fcimb.2020.00378] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 06/18/2020] [Indexed: 12/16/2022] Open
Abstract
Escherichia coli carrying prophage with genes that encode for Shiga toxins are categorized as Shiga toxin-producing E. coli (STEC) pathotype. Illnesses caused by STEC in humans, which are often foodborne, range from mild to bloody diarrhea with life-threatening complications of renal failure and hemolytic uremic syndrome and even death, particularly in children. As many as 158 of the total 187 serogroups of E. coli are known to carry Shiga toxin genes, which makes STEC a major pathotype of E. coli. Seven STEC serogroups, called top-7, which include O26, O45, O103, O111, O121, O145, and O157, are responsible for the majority of the STEC-associated human illnesses. The STEC serogroups, other than the top-7, called “non-top-7” have also been associated with human illnesses, more often as sporadic infections. Ruminants, particularly cattle, are principal reservoirs of STEC and harbor the organisms in the hindgut and shed in the feces, which serves as a major source of food and water contaminations. A number of studies have reported on the fecal prevalence of top-7 STEC in cattle feces. However, there is paucity of data on the prevalence of non-top-7 STEC serogroups in cattle feces, generally because of lack of validated detection methods. The objective of our study was to develop and validate 14 sets of multiplex PCR (mPCR) assays targeting serogroup-specific genes to detect 137 non-top-7 STEC serogroups previously reported to be present in cattle feces. Each assay included 7–12 serogroups and primers were designed to amplify the target genes with distinct amplicon sizes for each serogroup that can be readily identified within each assay. The assays were validated with 460 strains of known serogroups. The multiplex PCR assays designed in our study can be readily adapted by most laboratories for rapid identification of strains belonging to the non-top-7 STEC serogroups associated with cattle.
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Affiliation(s)
- Justin B Ludwig
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, United States
| | - Xiaorong Shi
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, United States
| | - Pragathi B Shridhar
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, United States
| | - Elisabeth L Roberts
- E. coli Reference Center, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, PA, United States
| | - Chitrita DebRoy
- E. coli Reference Center, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, PA, United States
| | - Randy K Phebus
- Department of Animal Sciences and Industry/Food Science Institute, Kansas State University, Manhattan, KS, United States
| | - Jianfa Bai
- Veterinary Diagnostic Laboratory, Industry/Food Science Institute, Kansas State University, Manhattan, KS, United States
| | - T G Nagaraja
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, KS, United States
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Response to Questions Posed by the Food and Drug Administration Regarding Virulence Factors and Attributes that Define Foodborne Shiga Toxin-Producing Escherichia coli (STEC) as Severe Human Pathogens †. J Food Prot 2019; 82:724-767. [PMID: 30969806 DOI: 10.4315/0362-028x.jfp-18-479] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
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- NACMCF Executive Secretariat, * U.S. Department of Agriculture, Food Safety and Inspection Service, Office of Public Health Science, PP3, 9-178, 1400 Independence Avenue S.W., Washington, D.C. 20250-3700, USA
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Ross CM, Rapp D, Cave VM, Brightwell G. Prevalence of Shiga toxin-producing Escherichia coli in pasture-based dairy herds. Lett Appl Microbiol 2018; 68:112-119. [PMID: 30411807 DOI: 10.1111/lam.13096] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 10/01/2018] [Accepted: 10/31/2018] [Indexed: 12/01/2022]
Abstract
Shiga toxin-producing Escherichia coli strains (STEC) are food-borne pathogens. While E. coli O157:H7 is commonly associated with cattle, less is known about the prevalence of non-O157 STEC serogroups in bovines. This study evaluated the prevalence and virulence status of O157:H7 and six E. coli O-serogroups (O26, O103, O45, O145, O121, O111) in New Zealand dairy farms using molecular as well as culture-based methods. Fresh farm dairy effluent (FDE) (n = 36) and composite calf faeces (n = 12) were collected over three samplings from 12 dairy farms. All seven target serogroups were detected through molecular techniques. Of the 202 isolates which were serologically confirmed following traditional culturing and immunomagnetic separation (IMS), O103, O26, O45 and O121 were the most common serogroups, being found in 81, 47, 42 and 32% of the FDE and in 17, 33, 25 and 9% of the calf faeces respectively. The majority (157/202) of the isolates were negative for stx and eae virulence genes. The prevalence of the seven target STEC was low, and only nine O26 isolates (4%) were recovered from four of the farms. The study has highlighted the need for improving the isolation of Top 7 STEC from the stx-negative populations present in fresh dairy effluent and calf faeces. SIGNIFICANCE AND IMPACT OF THE STUDY: Shiga toxin-producing Escherichia coli (STEC) are important food-borne pathogens that can cause severe illness in humans. Cattle are asymptomatic reservoirs for STEC, and transmission to humans can be by consumption of food products or water contaminated with cattle faeces. Our study investigated the prevalence of O157:H7 and six E. coli serogroups of STEC (O26, O103, O45, O145, O121, O111) over time in the dairy reservoir and increases the knowledge and understanding of these pathogens on pasture-based farms. Such information is required to develop risk-assessment models aiming at limiting transmission of these STEC to human.
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Affiliation(s)
- C M Ross
- Food & Bio-based Products, AgResearch Ltd, Hopkirk Research Institute, Palmerston North, New Zealand
| | - D Rapp
- Food & Bio-based Products, AgResearch Ltd, Hopkirk Research Institute, Palmerston North, New Zealand
| | - V M Cave
- Bioinformatics & Statistics, AgResearch Ltd, Hamilton, New Zealand
| | - G Brightwell
- Food & Bio-based Products, AgResearch Ltd, Hopkirk Research Institute, Palmerston North, New Zealand
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Abstract
AbstractO-antigens present on the surface ofEscherichia coliprovide antigenic specificity for the strain and are the main components for O-serogroup designation. Serotyping using O-group-specific antisera for the identification ofE. coliO-serogroups has been traditionally the gold-standard for distinguishingE. colistrains. Knowledge of the O-group is important for determining pathogenic lineage, classifyingE. colifor epidemiological studies, for determining virulence, and for tracing outbreaks of diseases and sources of infection. However, serotyping has limitations, as the antisera generated against each specific O-group may cross-react, many strains are non-typeable, and others can autoagglutinate or be rough (lacking an O-antigen). Currently, the nucleotide sequences are available for most of the 187 designatedE. coliO-groups. Public health and other laboratories are considering whole genome sequencing to develop genotypic methods to determine O-groups. These procedures require instrumentation and analysis that may not be accessible and may be cost-prohibitive at this time. In this review, we have identified unique gene sequences within the O-antigen gene clusters and have targeted these genes for identification of O-groups using the polymerase chain reaction. This information can be used to distinguish O-groups by developing other platforms forE. colidiagnostics in the future.
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Noll LW, Worley JN, Yang X, Shridhar PB, Ludwig JB, Shi X, Bai J, Caragea D, Meng J, Nagaraja TG. Comparative genomics reveals differences in mobile virulence genes of Escherichia coli O103 pathotypes of bovine fecal origin. PLoS One 2018; 13:e0191362. [PMID: 29389941 PMCID: PMC5794082 DOI: 10.1371/journal.pone.0191362] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 01/03/2018] [Indexed: 01/09/2023] Open
Abstract
Escherichia coli O103, harbored in the hindgut and shed in the feces of cattle, can be enterohemorrhagic (EHEC), enteropathogenic (EPEC), or putative non-pathotype. The genetic diversity particularly that of virulence gene profiles within O103 serogroup is likely to be broad, considering the wide range in severity of illness. However, virulence descriptions of the E. coli O103 strains isolated from cattle feces have been primarily limited to major genes, such as Shiga toxin and intimin genes. Less is known about the frequency at which other virulence genes exist or about genes associated with the mobile genetic elements of E. coli O103 pathotypes. Our objective was to utilize whole genome sequencing (WGS) to identify and compare major and putative virulence genes of EHEC O103 (positive for Shiga toxin gene, stx1, and intimin gene, eae; n = 43), EPEC O103 (negative for stx1 and positive for eae; n = 13) and putative non-pathotype O103 strains (negative for stx and eae; n = 13) isolated from cattle feces. Six strains of EHEC O103 from human clinical cases were also included. All bovine EHEC strains (43/43) and a majority of EPEC (12/13) and putative non-pathotype strains (12/13) were O103:H2 serotype. Both bovine and human EHEC strains had significantly larger average genome sizes (P < 0.0001) and were positive for a higher number of adherence and toxin-based virulence genes and genes on mobile elements (prophages, transposable elements, and plasmids) than EPEC or putative non-pathotype strains. The genome size of the three pathotypes positively correlated (R2 = 0.7) with the number of genes carried on mobile genetic elements. Bovine strains clustered phylogenetically by pathotypes, which differed in several key virulence genes. The diversity of E. coli O103 pathotypes shed in cattle feces is likely reflective of the acquisition or loss of virulence genes carried on mobile genetic elements.
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Affiliation(s)
- Lance W. Noll
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, Kansas, United States of America
| | - Jay N. Worley
- Joint Institute for Food Safety and Applied Nutrition and Department of Nutrition and Food Science, University of Maryland, College Park, Maryland, United States of America
| | - Xun Yang
- Joint Institute for Food Safety and Applied Nutrition and Department of Nutrition and Food Science, University of Maryland, College Park, Maryland, United States of America
| | - Pragathi B. Shridhar
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, Kansas, United States of America
| | - Justin B. Ludwig
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, Kansas, United States of America
| | - Xiaorong Shi
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, Kansas, United States of America
| | - Jianfa Bai
- Veterinary Diagnostic Laboratory, Kansas State University, Manhattan, Kansas, United States of America
| | - Doina Caragea
- Department of Computing and Information Sciences, Kansas State University, Manhattan, Kansas, United States of America
| | - Jianghong Meng
- Joint Institute for Food Safety and Applied Nutrition and Department of Nutrition and Food Science, University of Maryland, College Park, Maryland, United States of America
| | - T. G. Nagaraja
- Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, Kansas, United States of America
- * E-mail:
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Ogura Y, Gotoh Y, Itoh T, Sato MP, Seto K, Yoshino S, Isobe J, Etoh Y, Kurogi M, Kimata K, Maeda E, Piérard D, Kusumoto M, Akiba M, Tominaga K, Kirino Y, Kato Y, Shirahige K, Ooka T, Ishijima N, Lee KI, Iyoda S, Mainil JG, Hayashi T. Population structure of Escherichia coli O26 : H11 with recent and repeated stx2 acquisition in multiple lineages. Microb Genom 2017; 3:e000141. [PMID: 29208163 PMCID: PMC5729918 DOI: 10.1099/mgen.0.000141] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 11/06/2017] [Indexed: 12/21/2022] Open
Abstract
A key virulence factor of enterohaemorrhagic Escherichia coli (EHEC) is the bacteriophage-encoded Shiga toxin (Stx). Stxs are classified into two types, Stx1 and Stx2, and Stx2-producing strains are thought to cause more severe infections than strains producing only Stx1. Although O26 : H11 is the second most prevalent EHEC following O157 : H7, the majority of O26 : H11 strains produce Stx1 alone. However, Stx2-producing O26 strains have increasingly been detected worldwide. Through a large-scale genome analysis, we present a global phylogenetic overview and evolutionary timescale for E. coli O26 : H11. The origin of O26 has been estimated to be 415 years ago. Sequence type 21C1 (ST21C1), one of the two sublineages of ST21, the most predominant O26 : H11 lineage worldwide, emerged 213 years ago from one of the three ST29 sublineages (ST29C2). The other ST21 lineage (ST21C2) emerged 95 years ago from ST21C1. Increases in population size occurred in the late 20th century for all of the O26 lineages, but most remarkably for ST21C2. Analysis of the distribution of stx2-positive strains revealed the recent and repeated acquisition of the stx2 gene in multiple lineages of O26, both in ST21 and ST29. Other major EHEC virulence genes, such as type III secretion system effector genes and plasmid-encoded virulence genes, were well conserved in ST21 compared to ST29. In addition, more antimicrobial-resistance genes have accumulated in the ST21C1 lineage. Although current attention is focused on several highly virulent ST29 clones that have acquired the stx2 gene, there is also a considerable risk that the ST21 lineage could yield highly virulent clones.
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Affiliation(s)
| | | | | | | | - Kazuko Seto
- Osaka Prefectural Institute of Public Health, Osaka, Japan
| | - Shyuji Yoshino
- Miyazaki Prefectural Institute for Public Health and Environment, Miyazaki, Japan
| | | | - Yoshiki Etoh
- Fukuoka Institute of Health and Environmental Sciences, Fukuoka, Japan
| | - Mariko Kurogi
- Miyazaki Prefectural Institute for Public Health and Environment, Miyazaki, Japan
| | | | - Eriko Maeda
- Fukuoka Institute of Health and Environmental Sciences, Fukuoka, Japan
| | | | - Masahiro Kusumoto
- National Institute of Animal Health, National Agriculture and Food Research Organization, Ibaraki, Japan
| | - Masato Akiba
- National Institute of Animal Health, Ibaraki, Japan
| | - Kiyoshi Tominaga
- Yamaguchi Prefectural Institute of Public Health and Environment, Yamaguchi, Japan
| | | | | | | | | | | | - Ken-ichi Lee
- National Institute of Animal Health, National Agriculture and Food Research Organization, Ibaraki, Japan
| | - Sunao Iyoda
- National Institute of Animal Health, National Agriculture and Food Research Organization, Ibaraki, Japan
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Real-time genomic investigation underlying the public health response to a Shiga toxin-producing Escherichia coli O26:H11 outbreak in a nursery. Epidemiol Infect 2017; 145:2998-3006. [PMID: 28925349 DOI: 10.1017/s0950268817001923] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) is a significant cause of gastrointestinal infection and the haemolytic-uremic syndrome (HUS). STEC outbreaks are commonly associated with food but animal contact is increasingly being implicated in its transmission. We report an outbreak of STEC affecting young infants at a nursery in a rural community (three HUS cases, one definite case, one probable case, three possible cases and five carriers, based on the combination of clinical, epidemiological and laboratory data) identified using culture-based and molecular techniques. The investigation identified repeated animal contact (animal farming and petting) as a likely source of STEC introduction followed by horizontal transmission. Whole genome sequencing (WGS) was used for real-time investigation of the incident and revealed a unique strain of STEC O26:H11 carrying stx2a and intimin. Following a public health intervention, no additional cases have occurred. This is the first STEC outbreak reported from Israel. WGS proved as a useful tool for rapid laboratory characterization and typing of the outbreak strain and informed the public health response at an early stage of this unusual outbreak.
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Delannoy S, Mariani-Kurkdjian P, Webb HE, Bonacorsi S, Fach P. The Mobilome; A Major Contributor to Escherichia coli stx2-Positive O26:H11 Strains Intra-Serotype Diversity. Front Microbiol 2017; 8:1625. [PMID: 28932209 PMCID: PMC5592225 DOI: 10.3389/fmicb.2017.01625] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 08/10/2017] [Indexed: 12/12/2022] Open
Abstract
Shiga toxin-producing Escherichia coli of serotype O26:H11/H- constitute a diverse group of strains and several clones with distinct genetic characteristics have been identified and characterized. Whole genome sequencing was performed using Illumina and PacBio technologies on eight stx2-positive O26:H11 strains circulating in France. Comparative analyses of the whole genome of the stx2-positive O26:H11 strains indicate that several clones of EHEC O26:H11 are co-circulating in France. Phylogenetic analysis of the French strains together with stx2-positive and stx-negative E. coli O26:H11 genomes obtained from Genbank indicates the existence of four clonal complexes (SNP-CCs) separated in two distinct lineages, one of which comprises the "new French clone" (SNP-CC1) that appears genetically closely related to stx-negative attaching and effacing E. coli (AEEC) strains. Interestingly, the whole genome SNP (wgSNP) phylogeny is summarized in the cas gene phylogeny, and a simple qPCR assay targeting the CRISPR array specific to SNP-CC1 (SP_O26-E) can distinguish between the two main lineages. The PacBio sequencing allowed a detailed analysis of the mobile genetic elements (MGEs) of the strains. Numerous MGEs were identified in each strain, including a large number of prophages and up to four large plasmids, representing overall 8.7-19.8% of the total genome size. Analysis of the prophage pool of the strains shows a considerable diversity with a complex history of recombination. Each clonal complex (SNP-CC) is characterized by a unique set of plasmids and phages, including stx-prophages, suggesting evolution through separate acquisition events. Overall, the MGEs appear to play a major role in O26:H11 intra-serotype clonal diversification.
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Affiliation(s)
- Sabine Delannoy
- Université Paris-Est, ANSES, Food Safety Laboratory, Platform IdentyPathMaisons-Alfort, France
| | - Patricia Mariani-Kurkdjian
- Assistance Publique Hopitaux de Paris, Hôpital Robert-Debré, Service de Microbiologie, CNR Associé Escherichia coliParis, France
- Infection, Antimicrobials, Modelling, Evolution, UMR 1137, Institut National de la Santé et de la Recherche MédicaleParis, France
- Infection, Antimicrobials, Modelling, Evolution, UMR 1137, Univ Paris Diderot, Sorbonne Paris CitéParis, France
| | - Hattie E. Webb
- Department of Animal and Food Sciences, Texas Tech UniversityLubbock, TX, United States
| | - Stephane Bonacorsi
- Assistance Publique Hopitaux de Paris, Hôpital Robert-Debré, Service de Microbiologie, CNR Associé Escherichia coliParis, France
- Infection, Antimicrobials, Modelling, Evolution, UMR 1137, Institut National de la Santé et de la Recherche MédicaleParis, France
- Infection, Antimicrobials, Modelling, Evolution, UMR 1137, Univ Paris Diderot, Sorbonne Paris CitéParis, France
| | - Patrick Fach
- Université Paris-Est, ANSES, Food Safety Laboratory, Platform IdentyPathMaisons-Alfort, France
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Fratamico PM, DebRoy C, Liu Y, Needleman DS, Baranzoni GM, Feng P. Advances in Molecular Serotyping and Subtyping of Escherichia coli. Front Microbiol 2016; 7:644. [PMID: 27199968 PMCID: PMC4853403 DOI: 10.3389/fmicb.2016.00644] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 04/18/2016] [Indexed: 01/25/2023] Open
Abstract
Escherichia coli plays an important role as a member of the gut microbiota; however, pathogenic strains also exist, including various diarrheagenic E. coli pathotypes and extraintestinal pathogenic E. coli that cause illness outside of the GI-tract. E. coli have traditionally been serotyped using antisera against the ca. 186 O-antigens and 53 H-flagellar antigens. Phenotypic methods, including bacteriophage typing and O- and H- serotyping for differentiating and characterizing E. coli have been used for many years; however, these methods are generally time consuming and not always accurate. Advances in next generation sequencing technologies have made it possible to develop genetic-based subtyping and molecular serotyping methods for E. coli, which are more discriminatory compared to phenotypic typing methods. Furthermore, whole genome sequencing (WGS) of E. coli is replacing established subtyping methods such as pulsed-field gel electrophoresis, providing a major advancement in the ability to investigate food-borne disease outbreaks and for trace-back to sources. A variety of sequence analysis tools and bioinformatic pipelines are being developed to analyze the vast amount of data generated by WGS and to obtain specific information such as O- and H-group determination and the presence of virulence genes and other genetic markers.
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Affiliation(s)
- Pina M. Fratamico
- Eastern Regional Research Center, Agricultural Research Service, United States Department of Agriculture, WyndmoorPA, USA
| | - Chitrita DebRoy
- Department of Veterinary and Biomedical Sciences, Pennsylvania State University, University ParkPA, USA
| | - Yanhong Liu
- Eastern Regional Research Center, Agricultural Research Service, United States Department of Agriculture, WyndmoorPA, USA
| | - David S. Needleman
- Eastern Regional Research Center, Agricultural Research Service, United States Department of Agriculture, WyndmoorPA, USA
| | - Gian Marco Baranzoni
- Eastern Regional Research Center, Agricultural Research Service, United States Department of Agriculture, WyndmoorPA, USA
| | - Peter Feng
- Division of Microbiology, U.S. Food and Drug Administration, College ParkMD, USA
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11
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Ison SA, Delannoy S, Bugarel M, Nagaraja TG, Renter DG, den Bakker HC, Nightingale KK, Fach P, Loneragan GH. Targeted Amplicon Sequencing for Single-Nucleotide-Polymorphism Genotyping of Attaching and Effacing Escherichia coli O26:H11 Cattle Strains via a High-Throughput Library Preparation Technique. Appl Environ Microbiol 2016; 82:640-9. [PMID: 26567298 PMCID: PMC4711113 DOI: 10.1128/aem.03182-15] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2015] [Accepted: 11/04/2015] [Indexed: 12/31/2022] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) O26:H11, a serotype within Shiga toxin-producing E. coli (STEC) that causes severe human disease, has been considered to have evolved from attaching and effacing E. coli (AEEC) O26:H11 through the acquisition of a Shiga toxin-encoding gene. Targeted amplicon sequencing using next-generation sequencing technology of 48 phylogenetically informative single-nucleotide polymorphisms (SNPs) and three SNPs differentiating Shiga toxin-positive (stx-positive) strains from Shiga toxin-negative (stx-negative) strains were used to infer the phylogenetic relationships of 178 E. coli O26:H11 strains (6 stx-positive strains and 172 stx-negative AEEC strains) from cattle feces to 7 publically available genomes of human clinical strains. The AEEC cattle strains displayed synonymous SNP genotypes with stx2-positive sequence type 29 (ST29) human O26:H11 strains, while stx1 ST21 human and cattle strains clustered separately, demonstrating the close phylogenetic relatedness of these Shiga toxin-negative AEEC cattle strains and human clinical strains. With the exception of seven stx-negative strains, five of which contained espK, three stx-related SNPs differentiated the STEC strains from non-STEC strains, supporting the hypothesis that these AEEC cattle strains could serve as a potential reservoir for new or existing pathogenic human strains. Our results support the idea that targeted amplicon sequencing for SNP genotyping expedites strain identification and genetic characterization of E. coli O26:H11, which is important for food safety and public health.
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Affiliation(s)
- Sarah A Ison
- Department of Animal and Food Sciences, Texas Tech University, Lubbock, Texas, USA
| | - Sabine Delannoy
- ANSES Food Safety Laboratory, Platform IdentyPath, Université Paris-Est, Maisons-Alfort, France
| | - Marie Bugarel
- Department of Animal and Food Sciences, Texas Tech University, Lubbock, Texas, USA
| | - Tiruvoor G Nagaraja
- Department of Diagnostic Medicine Pathobiology, Kansas State University, Manhattan, Kansas, USA
| | - David G Renter
- Department of Diagnostic Medicine Pathobiology, Kansas State University, Manhattan, Kansas, USA
| | - Henk C den Bakker
- Department of Animal and Food Sciences, Texas Tech University, Lubbock, Texas, USA
| | - Kendra K Nightingale
- Department of Animal and Food Sciences, Texas Tech University, Lubbock, Texas, USA
| | - Patrick Fach
- ANSES Food Safety Laboratory, Platform IdentyPath, Université Paris-Est, Maisons-Alfort, France
| | - Guy H Loneragan
- Department of Animal and Food Sciences, Texas Tech University, Lubbock, Texas, USA
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