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Wang X, Yu D, Chui L, Zhou T, Feng Y, Cao Y, Zhi S. A Comprehensive Review on Shiga Toxin Subtypes and Their Niche-Related Distribution Characteristics in Shiga-Toxin-Producing E. coli and Other Bacterial Hosts. Microorganisms 2024; 12:687. [PMID: 38674631 PMCID: PMC11052178 DOI: 10.3390/microorganisms12040687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Revised: 03/25/2024] [Accepted: 03/27/2024] [Indexed: 04/28/2024] Open
Abstract
Shiga toxin (Stx), the main virulence factor of Shiga-toxin-producing E. coli (STEC), was first discovered in Shigella dysenteriae strains. While several other bacterial species have since been reported to produce Stx, STEC poses the most significant risk to human health due to its widespread prevalence across various animal hosts that have close contact with human populations. Based on its biochemical and molecular characteristics, Shiga toxin can be grouped into two types, Stx1 and Stx2, among which a variety of variants and subtypes have been identified in various bacteria and host species. Interestingly, the different Stx subtypes appear to vary in their host distribution characteristics and in the severity of diseases that they are associated with. As such, this review provides a comprehensive overview on the bacterial species that have been recorded to possess stx genes to date, with a specific focus on the various Stx subtype variants discovered in STEC, their prevalence in certain host species, and their disease-related characteristics. This review provides a better understanding of the Stx subtypes and highlights the need for rapid and accurate approaches to toxin subtyping for the proper evaluation of the health risks associated with Shiga-toxin-related bacterial food contamination and human infections.
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Affiliation(s)
- Xuan Wang
- School of Public Health, Ningbo University, Ningbo 315000, China; (X.W.); (T.Z.); (Y.F.)
| | - Daniel Yu
- School of Public Health, Univeristy of Alberta, Edmonton, AB T6G 2R3, Canada;
| | - Linda Chui
- Alberta Precision Laboratories-ProvLab, Edmonton, AB T6G 2J2, Canada;
- Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, AB T6G 2B7, Canada
| | - Tiantian Zhou
- School of Public Health, Ningbo University, Ningbo 315000, China; (X.W.); (T.Z.); (Y.F.)
| | - Yu Feng
- School of Public Health, Ningbo University, Ningbo 315000, China; (X.W.); (T.Z.); (Y.F.)
| | - Yuhao Cao
- School of Basic Medical Sciences, Ningbo University, Ningbo 315000, China;
| | - Shuai Zhi
- School of Public Health, Ningbo University, Ningbo 315000, China; (X.W.); (T.Z.); (Y.F.)
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Fang Y, Tran F, Stanford K, Yang X. Stress Resistance and Virulence Gene Profiles Associated with Phylogeny and Phenotypes of Escherichia coli from Cattle. J Food Prot 2023; 86:100122. [PMID: 37355007 DOI: 10.1016/j.jfp.2023.100122] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 06/15/2023] [Accepted: 06/19/2023] [Indexed: 06/26/2023]
Abstract
Seven serogroups of E. coli (Top seven E. coli) are frequently implicated in foodborne outbreaks in North America, largely due to their carriage of Shiga toxin genes (stx). This study aimed to profile resistance genes and virulence factors (VF), and their potential association with phylogeny and phenotypes of Top seven E. coli originating from cattle in Canada. 155 Top seven E. coli isolates previously characterized for heat and acid resistance and biofilm-forming ability were whole-genome sequenced and analyzed for phylogeny, VF, and stress resistance genes. The 155 E. coli strains belonged to six phylogroups: A (n = 32), B1 (n = 93), C (n = 3), D (n = 11), E (n = 15), and G (n = 1). Different phylogroups were clearly separated on the core genome tree, with strains of the same serotype closely clustered. The carriage of stx and the transmissible locus of stress tolerance (tLST), the extreme heat resistance marker, was mutually exclusive, in 33 and 15 genomes, respectively. A novel O84:H2 strain carrying stx1a was also identified. In total, 70, 41, and 32 VF, stress resistance genes and antibiotic resistance genes were identified. The stress resistance genes included those for metal (n = 29), biocides/acid (n = 4), and heat (n = 8) resistance. All heat resistance genes and most metal-resistance genes that were differentially distributed among the phylogroups were exclusively in phylogroup A. VF were least and most present in phylogroups A and D, respectively. No specific genes associated with acid resistance or biofilm formation phenotypes were identified. VF were more abundant (P < 0.05) in the non-biofilm-forming population and acid-resistant population.
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Affiliation(s)
- Yuan Fang
- Agriculture and Agri-Food Canada Lacombe Research and Development Centre, 6000 C & E Trail, Lacombe, AB T4L 1W1, Canada
| | - Frances Tran
- Agriculture and Agri-Food Canada Lacombe Research and Development Centre, 6000 C & E Trail, Lacombe, AB T4L 1W1, Canada
| | - Kim Stanford
- University of Lethbridge, Lethbridge, AB T1K 3M4, Canada
| | - Xianqin Yang
- Agriculture and Agri-Food Canada Lacombe Research and Development Centre, 6000 C & E Trail, Lacombe, AB T4L 1W1, Canada.
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3
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Salaheen S, Kim SW, Springer HR, Hovingh EP, Van Kessel JAS, Haley BJ. Genomic diversity of antimicrobial-resistant and Shiga toxin gene-harboring non-O157 Escherichia coli from dairy calves. J Glob Antimicrob Resist 2023; 33:164-170. [PMID: 36898633 DOI: 10.1016/j.jgar.2023.02.022] [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: 09/29/2022] [Revised: 11/22/2022] [Accepted: 02/24/2023] [Indexed: 03/11/2023] Open
Abstract
OBJECTIVES Shiga toxin-producing Escherichia coli (STEC) are globally significant foodborne pathogens. Dairy calves are a known reservoir of both O157 and non-O157 STEC. The objective of this study was to comprehensively evaluate the genomic attributes, diversity, virulence factors, and antimicrobial resistance gene (ARG) profiles of the STEC from preweaned and postweaned dairy calves in commercial dairy herds. METHODS In total, 31 non-O157 STEC were identified as part of a larger study focused on the pangenome of >1000 E. coli isolates from the faeces of preweaned and postweaned dairy calves on commercial dairy farms. These 31 genomes were sequenced on an Illumina NextSeq500 platform. RESULTS Based on the phylogenetic analyses, the STEC isolates were determined to be polyphyletic, with at least three phylogroups: A (32%), B1 (58%), and G (3%). These phylogroups represented at least 16 sequence types and 11 serogroups, including two of the 'big six' serogroups, O103 and O111. Several Shiga toxin gene subtypes were identified in the genomes, including stx1a, stx2a, stx2c, stx2d, and stx2g. Using the ResFinder database, the majority of the isolates (>50%) were determined to be multidrug-resistant strains because they harboured genes conferring resistance to three or more classes of antimicrobials, including some of human health significance (e.g., β-lactams, macrolides, and fosfomycin). Additionally, non-O157 STEC strain persistence and transmission within a farm was observed. CONCLUSION Dairy calves are a reservoir of phylogenomically diverse multidrug-resistant non-O157 STEC. Information from this study may inform assessments of public health risk and guide preharvest prevention strategies focusing on STEC reservoirs.
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Affiliation(s)
- Serajus Salaheen
- Environmental Microbial and Food Safety Laboratory, Beltsville Agricultural Research Center, Agricultural Research Service, United States Department of Agriculture, Beltsville, Maryland
| | - Seon Woo Kim
- Environmental Microbial and Food Safety Laboratory, Beltsville Agricultural Research Center, Agricultural Research Service, United States Department of Agriculture, Beltsville, Maryland
| | - Hayley R Springer
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania
| | - Ernest P Hovingh
- Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, Pennsylvania
| | - Jo Ann S Van Kessel
- Environmental Microbial and Food Safety Laboratory, Beltsville Agricultural Research Center, Agricultural Research Service, United States Department of Agriculture, Beltsville, Maryland
| | - Bradd J Haley
- Environmental Microbial and Food Safety Laboratory, Beltsville Agricultural Research Center, Agricultural Research Service, United States Department of Agriculture, Beltsville, Maryland.
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4
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Escherichia coli virulence genes and clonality in strains from diarrhoea in goat kids. Small Rumin Res 2023. [DOI: 10.1016/j.smallrumres.2023.106906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Ray R, Singh P. Prevalence and Implications of Shiga Toxin-Producing E. coli in Farm and Wild Ruminants. Pathogens 2022; 11:1332. [PMID: 36422584 PMCID: PMC9694250 DOI: 10.3390/pathogens11111332] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Revised: 11/04/2022] [Accepted: 11/08/2022] [Indexed: 08/27/2023] Open
Abstract
Shiga-toxin-producing Escherichia coli (STEC) is a food-borne pathogen that causes human gastrointestinal infections across the globe, leading to kidney failure or even death in severe cases. E. coli are commensal members of humans and animals' (cattle, bison, and pigs) guts, however, may acquire Shiga-toxin-encoded phages. This acquisition or colonization by STEC may lead to dysbiosis in the intestinal microbial community of the host. Wildlife and livestock animals can be asymptomatically colonized by STEC, leading to pathogen shedding and transmission. Furthermore, there has been a steady uptick in new STEC variants representing various serotypes. These, along with hybrids of other pathogenic E. coli (UPEC and ExPEC), are of serious concern, especially when they possess enhanced antimicrobial resistance, biofilm formation, etc. Recent studies have reported these in the livestock and food industry with minimal focus on wildlife. Disturbed natural habitats and changing climates are increasingly creating wildlife reservoirs of these pathogens, leading to a rise in zoonotic infections. Therefore, this review comprehensively surveyed studies on STEC prevalence in livestock and wildlife hosts. We further present important microbial and environmental factors contributing to STEC spread as well as infections. Finally, we delve into potential strategies for limiting STEC shedding and transmission.
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Affiliation(s)
| | - Pallavi Singh
- Department of Biological Sciences, Northern Illinois University, Dekalb, IL 60115, USA
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Development and validation of high-resolution melting assays for the detection of potentially virulent strains of Escherichia coli O103 and O121. Food Control 2022. [DOI: 10.1016/j.foodcont.2022.109095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Onyeka LO, Adesiyun AA, Keddy KH, Hassim A, Smith AM, Thompson PN. CHARACTERIZATION AND EPIDEMIOLOGICAL SUBTYPING OF SHIGA TOXIN-PRODUCING ESCHERICHIA COLI ISOLATED FROM THE BEEF PRODUCTION CHAIN IN GAUTENG, SOUTH AFRICA. Prev Vet Med 2022; 205:105681. [DOI: 10.1016/j.prevetmed.2022.105681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 02/16/2022] [Accepted: 05/23/2022] [Indexed: 11/26/2022]
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Withenshaw SM, Smith RP, Davies R, Smith AEO, Gray E, Rodgers J. A systematized review and qualitative synthesis of potential risk factors associated with the occurrence of non‐O157 Shiga toxin‐producing
Escherichia coli
(STEC) in the primary production of cattle. Compr Rev Food Sci Food Saf 2022; 21:2363-2390. [DOI: 10.1111/1541-4337.12929] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 01/19/2022] [Accepted: 01/24/2022] [Indexed: 12/22/2022]
Affiliation(s)
- Susan M. Withenshaw
- Department of Epidemiological Sciences Animal and Plant Health Agency – Weybridge New Haw UK
| | - Richard P. Smith
- Department of Epidemiological Sciences Animal and Plant Health Agency – Weybridge New Haw UK
| | - Rob Davies
- Department of Bacteriology Animal and Plant Health Agency – Weybridge New Haw UK
| | - Alice E. O. Smith
- Department of Epidemiological Sciences Animal and Plant Health Agency – Weybridge New Haw UK
| | - Elizabeth Gray
- Department of Epidemiological Sciences Animal and Plant Health Agency – Weybridge New Haw UK
| | - John Rodgers
- Department of Bacteriology Animal and Plant Health Agency – Weybridge New Haw UK
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Tong P, Zhang L, Xie J, Zhang M, Tang X, Liu Y, Xia L, Su Z. Molecular Characteristics and Virulence Gene Analysis of Non-O157 Shiga Toxin-Producing Escherichia coli from Cattle in Xinjiang. Foodborne Pathog Dis 2021; 18:867-872. [PMID: 34415781 DOI: 10.1089/fpd.2021.0020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Non-O157 Shiga toxin (stx)-producing Escherichia coli (STEC) is recognized as an important human diarrheal pathogen. Cattle are the principal reservoirs of STEC, although other animals can be carriers. Humans are mainly infected by consuming contaminated drinking water or food. This study aimed to evaluate the virulence potential of isolated bovine non-O157 STEC to humans in Xinjiang. During 2015-2017, 978 rectal swab samples collected from cattle of 5 farms were screened for the presence of Shiga toxin-encoding genes by polymerase chain reaction. Strains identified as STEC were isolated from rectal swab samples, and were characterized for stx subtype, virulence genes, O serogroup, phylogenetic group, and hemolytic phenotype. Among 125 non-O157 STEC isolates, the prevalence percentages of stx1 and stx2 were 22 and 21, respectively, and 57% of the isolates carried both Shiga toxins. The stx subtypes were mainly found in the combination of stx1a/stx2a (57%), stx2a (20%), stx1a (22%), stx1a/stx2a/stx2c (1%), and stx2a/stx2c (1%). The enterohemolysin (ehxA) gene was found in 94% of the isolates. No intimin (eae) was detected. Hemolysis was observed in 33% of the isolates. Two STEC serogroups O145 (17%) and O113 (2%) were found, which were reported to be associated with outbreaks of human disease. Phylotyping assays showed that most strains largely belong to groups A (91%) and B1 (7%). The results of this study can help improve our understanding of the epidemiological aspects of bovine STEC and devise strategies for protection against it.
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Affiliation(s)
- Panpan Tong
- College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, China
| | - Ling Zhang
- College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, China
| | - Jinxin Xie
- College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, China
| | - Mengmeng Zhang
- College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, China
| | - Xuelin Tang
- College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, China
| | - Yingyu Liu
- College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, China
| | - Lining Xia
- College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, China
| | - Zhanqiang Su
- College of Veterinary Medicine, Xinjiang Agricultural University, Urumqi, China
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10
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Hu Y, Bai L, Zhao L, Wu L, Lv H, Li Q, Li X, Xie Q, Wang L, Liu C, Liu N, Cui S. Standardized Shiga-Toxin Encoding Genes Real-Time PCR Screening Methods Comparison and Development of an Internally Controlled Assay for Pan-stx2 Detection. J AOAC Int 2021; 104:1065-1071. [PMID: 33724375 DOI: 10.1093/jaoacint/qsab030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 02/26/2021] [Accepted: 02/27/2021] [Indexed: 11/13/2022]
Abstract
BACKGROUND Various primer and probe sets have been developed and standardized, but certain sets may have low efficiency or miss some stx-subtypes. OBJECTIVE To compare the efficiency of the recommended stx screening primers and probe sets in four standardized methods and develop a new primers and probe system with an internal amplification control (IAC) for all known stx2 subtypes. METHOD The inclusivity and specificity of recommended screening primers and probe sets in four standardized methods were compared. A new pan-stx2 primer and probe set was adapted from the International Organization for Standardization (ISO) method for all known stx2 subtypes. The robustness of the new method was assessed in seven laboratories and also assessed in ground beef and bean sprout samples. RESULTS None of the recommended screening primers and probe sets in the four standardized methods could efficiently amplify all the stx2 subtypes because of various mismatches in the primers or the probe sequences. A new primers and probe system adapted from the ISO method, through introducing degenerate bases in primers and probe sequences with an IAC, showed high amplification efficiency and specificity for all known stx2 subtypes in ground beef and bean sprouts samples. The specificity of the new method was assessed in seven laboratories and showed robust and consistent results. CONCLUSIONS This study provided evidence for Shiga-toxin producing Escherichia coli (STEC) screening method development, and the newly developed primers and probes system should be considered in the revision of the standardized methods. HIGHLIGHTS None of the recommended screening primer and probe set in the four official methods could efficiently amplify all the stx2 subtypes. A new developed primer and probe set showed high amplification efficiency and specificity for all known stx2 subtypes in fresh ground beef and bean sprouts samples. The newly developed stx2 screening system showed robustness and consistency during interlaboratory study.
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Affiliation(s)
- Ying Hu
- College of Food Science, Southwest University, No.2 Tiansheng Road, Beibei District, Chongqing, 400715, PR, China.,Department of Food Science, The National Institutes for Food and Drug Control, No.2 Tiantan Xili, Dongcheng District, Beijing 100050 , PR, China
| | - Li Bai
- Key Laboratory of Food Safety Risk Assessment, National Health Commission of the People's Republic of China, China National Center for Food Safety Risk Assessment, Yard No.37, Guangqu Road, Chaoyang District, Beijing 100022, PR, China
| | - Linna Zhao
- Department of Food Science, The National Institutes for Food and Drug Control, No.2 Tiantan Xili, Dongcheng District, Beijing 100050 , PR, China
| | - Lingling Wu
- Center for Disease Control and Prevention of Henan Province, No.105 Nongye South Road, Zhengdong New District, Zhengzhou, 450016, PR, China
| | - Hong Lv
- Center for Disease Control and Prevention of Sichuan Province, No.6 Middle School Road, Chengdu, 610041, PR, China
| | - Qiongqiong Li
- Shanghai Institute of Food and Drug Control, No.1500 Zhangheng Road, Pudong New Area, Shanghai, 201203, PR, China
| | - Xinpeng Li
- Center for Disease Prevent and Control of Shandong Province, No. 16992 Jingshi Road, Jinan, 250014, PR, China
| | - Qingchao Xie
- Shanghai Ocean University, College of Food Science and Technology, No.999 Hucheng Ring Road, Pudong New Area, 201306, Shanghai, PR, China
| | - Lili Wang
- Beijing Centers for Disease Prevention and Control, Beijing Centers for Disease Preventive Medical Research, Beijing Key Laboratory of Diagnostic and Traceability Technologies for Food Poisoning, No.16 Heping Li Zhong Jie, Dongcheng District, Beijing, 100013, PR, China
| | - Chengwei Liu
- Center for Disease Prevent and Control of Jiangxi Province, No.555 Beijing Dong Lu, Nanchang, 330029, PR, China
| | - Na Liu
- Department of Food Science, The National Institutes for Food and Drug Control, No.2 Tiantan Xili, Dongcheng District, Beijing 100050 , PR, China
| | - Shenghui Cui
- Department of Food Science, The National Institutes for Food and Drug Control, No.2 Tiantan Xili, Dongcheng District, Beijing 100050 , PR, China
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Angappan M, Ghatak S, Milton AAP, Verma AK, Inbaraj S, Chaudhuri P, Agarwal RK, Thomas P. Detection of novel sequence types and zoonotic transmission potentiality among strains of Shiga toxigenic Escherichia coli (STEC) from dairy calves, animal handlers and associated environments. Braz J Microbiol 2021; 52:2541-2546. [PMID: 34241826 DOI: 10.1007/s42770-021-00561-9] [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: 11/09/2020] [Accepted: 06/27/2021] [Indexed: 11/26/2022] Open
Abstract
Shiga toxigenic Escherichia coli (STEC) is one of the most important food-borne zoonotic bacterial pathogens responsible for causing gastrointestinal infections, haemorrhagic colitis and haemolytic uremic syndrome. The present study was aimed to isolate and characterize STEC from neonatal dairy calves, animal handlers and their surrounding environment and to establish the genetic relationship among isolates by multilocus sequence typing (MLST). A total number of 115 samples were collected and processed for the isolation of E. coli. The occurrence rate of E. coli was 92.2% (106/115), of which, 18 were typed as STEC. Antibacterial susceptibility analysis revealed 11 (61.1%) strains as multiple drug-resistant (MDR). MLST analysis has delineated 16 sequence types (STs) including nine novel STs. Among STs, ST58 dominated with three strains and was recovered from the environment and neonatal calves. Strains from neonatal calves and humans showed genetic relatedness with significant bootstrap support values indicative of zoonotic transmission potentiality. Analysis of 211 global isolates belonging to 61 STs indicated predominant STs (ST 21, ST 33 and ST 3416) that can be either host-specific (ST 33 and ST 3416) or can be shared among human and bovine hosts (ST 21). The MLST analysis indicates genetic relatedness among isolates and the results predispose inter-host transmission and zoonotic spread.
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Affiliation(s)
- Madesh Angappan
- Division of Veterinary Public Health, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, 243122, India
- Division of Animal Health, ICAR Research Complex for NEH Region, Umiam, Meghalaya, 793103, India
| | - Sandeep Ghatak
- Division of Animal Health, ICAR Research Complex for NEH Region, Umiam, Meghalaya, 793103, India
| | | | - Asha Kumari Verma
- Division of Veterinary Public Health, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, 243122, India
| | - Sophia Inbaraj
- Division of Bacteriology and Mycology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, 243122, India
| | - Pallab Chaudhuri
- Division of Bacteriology and Mycology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, 243122, India
| | - Rajesh Kumar Agarwal
- Division of Bacteriology and Mycology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, 243122, India.
| | - Prasad Thomas
- Division of Bacteriology and Mycology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, 243122, India.
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12
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Identification, Shiga toxin subtypes and prevalence of minor serogroups of Shiga toxin-producing Escherichia coli in feedlot cattle feces. Sci Rep 2021; 11:8601. [PMID: 33883564 PMCID: PMC8060326 DOI: 10.1038/s41598-021-87544-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 03/23/2021] [Indexed: 01/12/2023] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) are foodborne pathogens that cause illnesses in humans ranging from mild to hemorrhagic enteritis with complications of hemolytic uremic syndrome and even death. Cattle are a major reservoir of STEC, which reside in the hindgut and are shed in the feces, a major source of food and water contaminations. Seven serogroups, O26, O45, O103, O111, O121, O145 and O157, called ‘top-7’, are responsible for the majority of human STEC infections in North America. Additionally, 151 serogroups of E. coli are known to carry Shiga toxin genes (stx). Not much is known about fecal shedding and prevalence and virulence potential of STEC other than the top-7. Our primary objectives were to identify serogroups of STEC strains, other than the top-7, isolated from cattle feces and subtype stx genes to assess their virulence potential. Additional objective was to develop and validate a novel multiplex PCR assay to detect and determine prevalence of six serogroups, O2, O74, O109, O131, O168, and O171, in cattle feces. A total of 351 strains, positive for stx gene and negative for the top-7 serogroups, isolated from feedlot cattle feces were used in the study. Of the 351 strains, 291 belonged to 16 serogroups and 60 could not be serogrouped. Among the 351 strains, 63 (17.9%) carried stx1 gene and 300 (82.1%) carried stx2, including 12 strains positive for both. The majority of the stx1 and stx2 were of stx1a (47/63; 74.6%) and stx2a subtypes (234/300; 78%), respectively, which are often associated with human infections. A novel multiplex PCR assay developed and validated to detect six serogroups, O2, O74, O109, O131, O168, and O171, which accounted for 86.9% of the STEC strains identified, was utilized to determine their prevalence in fecal samples (n = 576) collected from a commercial feedlot. Four serogroups, O2, O109, O168, and O171 were identified as the dominant serogroups prevalent in cattle feces. In conclusion, cattle shed in the feces a number of STEC serogroups, other than the top-7, and the majority of the strains isolated possessed stx2, particularly of the subtype 2a, suggesting their potential risk to cause human infections.
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Okuno K, Awasthi SP, Kopprio GA, Iguchi A, Hatanaka N, Hinenoya A, Lara RJ, Yamasaki S. Prevalence, O-genotype and Shiga toxin (Stx) 2 subtype of Stx-producing Escherichia coli strains isolated from Argentinean beef cattle. J Vet Med Sci 2021; 83:630-636. [PMID: 33612661 PMCID: PMC8111337 DOI: 10.1292/jvms.21-0002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The aims of this study were to investigate prevalence, O-genotype, and virulence gene profile including Shiga toxin (Stx) 2 gene-subtype of Stx-producing Escherichia coli (STEC) in beef cattle from the Bahía Blanca in Argentina. Rectal swabs were collected from 283 beef cattle in 2012. stx genes were detected in 90 (32%) out of the 283 rectal swabs by stx gene-specific PCR assay. The positive cases were 13 with stx1, 58 with stx2, and 19 with both stx1 and stx2. Among 90 stx gene-positive samples, 45 STEC strains were isolated, which included 3 stx1, 34 stx2, and eight stx1 and stx2 genes positive isolates. O-genotyping grouped 45 STEC strains into 19 different O-genotypes such as Og8, Og145, Og171, Og185 (4 from each), Og22, Og153, Og157 (3 from each) and others. Various stx2 gene-subtypes were identified in 42 STEC strains: 13 positive cases for stx2a, 11 for stx2c, 3 for stx2g, 10 for stx2a and stx2d, 4 for stx2a and stx2c, and 1 for stx2b, stx2c and stx2g. efaI gene, generally prevalent in clinical strains, was detected in relatively high in the STEC strains. These data suggest that stx2a and stx2c were distributed not only in O145 and O157 but also in minor O-genotypes of STEC in Argentina.
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Affiliation(s)
- Kentaro Okuno
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58, Rinkuourai-kita, Izumisano, Osaka 598-8531, Japan
| | - Sharda Prasad Awasthi
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58, Rinkuourai-kita, Izumisano, Osaka 598-8531, Japan.,Asian Health Science Research Institute, Osaka Prefecture University, 1-58, Rinkuourai-kita, Izumisano, Osaka 598-8531, Japan
| | - Germán A Kopprio
- Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Müggelseedamm 301, 12587, Berlin, Germany
| | - Atsushi Iguchi
- Department of Animal and Grassland Sciences, Faculty of Agriculture, University of Miyazaki, 1-1, Gakuen Kibanadai-nishi, Miyazaki 889-2192, Japan
| | - Noritoshi Hatanaka
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58, Rinkuourai-kita, Izumisano, Osaka 598-8531, Japan.,Asian Health Science Research Institute, Osaka Prefecture University, 1-58, Rinkuourai-kita, Izumisano, Osaka 598-8531, Japan
| | - Atsushi Hinenoya
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58, Rinkuourai-kita, Izumisano, Osaka 598-8531, Japan.,Asian Health Science Research Institute, Osaka Prefecture University, 1-58, Rinkuourai-kita, Izumisano, Osaka 598-8531, Japan
| | - Rubén José Lara
- National Council for Scientific and Technical Research, The Argentine Institute of Oceanography, Florida 4750, Complejo CONICET-Bahia Blanca Edificio E1, B8000FWB, Bahia Blanca, Argentina
| | - Shinji Yamasaki
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58, Rinkuourai-kita, Izumisano, Osaka 598-8531, Japan.,Asian Health Science Research Institute, Osaka Prefecture University, 1-58, Rinkuourai-kita, Izumisano, Osaka 598-8531, Japan
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14
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Distribution of Novel Og Types in Shiga Toxin-Producing Escherichia coli Isolated from Healthy Cattle. J Clin Microbiol 2021; 59:JCM.02624-20. [PMID: 33328174 DOI: 10.1128/jcm.02624-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 12/08/2020] [Indexed: 12/15/2022] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) is an important foodborne pathogen. Although most cases of STEC infection in humans are due to O157 and non-O157 serogroups, there are also reports of infection with STEC strains that cannot be serologically classified into any O serogroup (O-serogroup untypeable [OUT]). Recently, it has become clear that even OUT strains can be subclassified based on the diversity of O-antigen biosynthesis gene cluster (O-AGC) sequences. Cattle are thought to be a major reservoir of STEC strains belonging to various serotypes; however, the internal composition of OUT STEC strains in cattle remains unknown. In this study, we screened 366 STEC strains isolated from healthy cattle by using multiplex PCR kits including primers that targeted novel O-AGC types (Og types) found in OUT E. coli and Shigella strains in previous studies. Interestingly, 94 (25.7%) of these strains could be classified into 13 novel Og types. Genomic analysis revealed that the results of the in silico serotyping of novel Og-type strains were perfectly consistent with those of the PCR experiment. In addition, it was revealed that a dual Og8+OgSB17-type strain carried two types of O-AGCs from E. coli O8 and Shigella boydii type 17 tandemly inserted at the locus, with both antigens expressed on the cell surface. The results of this comprehensive analysis of cattle-derived STEC strains may help improve our understanding of the strains circulating in the environment. Additionally, the DNA-based serotyping systems used in this study could be used in future epidemiological studies and risk assessments of other STEC strains.
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15
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McCarthy SC, Burgess CM, Fanning S, Duffy G. An Overview of Shiga-Toxin Producing Escherichia coli Carriage and Prevalence in the Ovine Meat Production Chain. Foodborne Pathog Dis 2021; 18:147-168. [PMID: 33395551 DOI: 10.1089/fpd.2020.2861] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Shiga-toxin producing Escherichia coli (STEC) are zoonotic foodborne pathogens that are capable of causing serious human illness. Ovine ruminants are recognized as an important source of STEC and a notable contributor to contamination within the food industry. This review examined the prevalence of STEC in the ovine food production chain from farm-to-fork, reporting carriage in sheep herds, during abattoir processing, and in raw and ready-to-eat meats and meat products. Factors affecting the prevalence of STEC, including seasonality and animal age, were also examined. A relative prevalence can be obtained by calculating the mean prevalence observed over multiple surveys, weighted by sample number. A relative mean prevalence was obtained for STEC O157 and all STEC serogroups at multiple points along the ovine production chain by using suitable published surveys. A relative mean prevalence (and range) for STEC O157 was calculated: for feces 4.4% (0.2-28.1%), fleece 7.6% (0.8-12.8%), carcass 2.1% (0.2-9.8%), and raw ovine meat 1.9% (0.2-6.3%). For all STEC independent of serotype, a relative mean prevalence was calculated: for feces 33.3% (0.9-90.0%), carcass 58.7% (2.0-81.6%), and raw ovine meat 15.4% (2.7-35.5%). The prevalence of STEC in ovine fleece was reported in only one earlier survey, which recorded a prevalence of 86.2%. Animal age was reported to affect shedding in many surveys, with younger animals typically reported as having a higher prevalence of the pathogen. The prevalence of STEC decreases significantly along the ovine production chain after the application of postharvest interventions. Ovine products pose a small risk of potential STEC contamination to the food supply chain.
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Affiliation(s)
- Siobhán C McCarthy
- Food Safety Department, Teagasc Food Research Centre, Ashtown, Dublin, Ireland.,UCD-Centre for Food Safety, School of Public Health, Physiotherapy and Sports Science, University College Dublin, Dublin, Ireland
| | - Catherine M Burgess
- Food Safety Department, Teagasc Food Research Centre, Ashtown, Dublin, Ireland
| | - Séamus Fanning
- UCD-Centre for Food Safety, School of Public Health, Physiotherapy and Sports Science, University College Dublin, Dublin, Ireland
| | - Geraldine Duffy
- Food Safety Department, Teagasc Food Research Centre, Ashtown, Dublin, Ireland
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16
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Remfry SE, Amachawadi RG, Shi X, Bai J, Tokach MD, Dritz SS, Goodband RD, Derouchey JM, Woodworth JC, Nagaraja TG. Shiga Toxin-Producing Escherichia coli in Feces of Finisher Pigs: Isolation, Identification, and Public Health Implications of Major and Minor Serogroups†. J Food Prot 2021; 84:169-180. [PMID: 33411931 DOI: 10.4315/jfp-20-329] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 09/19/2020] [Indexed: 02/06/2023]
Abstract
ABSTRACT Shiga toxin-producing Escherichia coli (STEC) are major foodborne human pathogens that cause mild to hemorrhagic colitis, which could lead to complications of hemolytic uremic syndrome. Seven serogroups, O26, O45, O103, O111, O121, O145, and O157, account for the majority of the STEC illnesses in the United States. Shiga toxins 1 and 2, encoded by stx1 and stx2, respectively, and intimin, encoded by eae gene, are major virulence factors. Cattle are a major reservoir of STEC, but swine also harbor them in the hindgut and shed STEC in the feces. Our objectives were to use a culture method to isolate and identify major and minor serogroups of STEC in finisher pig feces. Shiga toxin genes were subtyped to assess public health implications of STEC. Fecal samples (n = 598) from finisher pigs, collected from 10 pig flows, were enriched in E. coli broth and tested for stx1, stx2, and eae by a multiplex PCR (mPCR) assay. Samples positive for stx1 or stx2 gene were subjected to culture methods, with or without immunomagnetic separation and plating on selective or nonselective media, for isolation and identification of stx-positive isolates. The culture method yielded a total of 178 isolates belonging to 23 serogroups. The three predominant serogroups were O8, O86, and O121. The 178 STEC strains included 26 strains with stx1a and 152 strains with stx2e subtypes. Strains with stx1a, particularly in association with eae (O26 and O103), have the potential to cause severe human infections. All stx2-positive isolates carried the subtype stx2e, a subtype that causes edema disease in swine, but is rarely involved in human infections. Several strains were also positive for genes that encode for enterotoxins, which are involved in neonatal and postweaning diarrhea in swine. In conclusion, our study showed that healthy finisher pigs harbored and shed several serogroups of E. coli carrying virulence genes involved in neonatal diarrhea, postweaning diarrhea, and edema disease, but prevalence of STEC of public health importance was low. HIGHLIGHTS
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Affiliation(s)
- S E Remfry
- Department of Clinical Sciences, Kansas State University, Manhattan, Kansas 66502, USA
| | - R G Amachawadi
- Department of Clinical Sciences, Kansas State University, Manhattan, Kansas 66502, USA.,Center for Outcomes Research and Epidemiology, Kansas State University, Manhattan, Kansas 66502, USA.,(ORCID: https://orcid.org/0000-0001-9689-1124 [R.G.A.])
| | - X Shi
- Department of Diagnostic Medicine and Pathobiology, Kansas State University, Manhattan, Kansas 66502, USA
| | - J Bai
- Veterinary Diagnostic Laboratory, Kansas State University, Manhattan, Kansas 66502, USA
| | - M D Tokach
- Department of Animal Sciences and Industry, Kansas State University, Manhattan, Kansas 66502, USA
| | - S S Dritz
- Department of Diagnostic Medicine and Pathobiology, Kansas State University, Manhattan, Kansas 66502, USA
| | - R D Goodband
- Department of Animal Sciences and Industry, Kansas State University, Manhattan, Kansas 66502, USA
| | - J M Derouchey
- Department of Animal Sciences and Industry, Kansas State University, Manhattan, Kansas 66502, USA
| | - J C Woodworth
- Department of Animal Sciences and Industry, Kansas State University, Manhattan, Kansas 66502, USA
| | - T G Nagaraja
- Department of Diagnostic Medicine and Pathobiology, Kansas State University, Manhattan, Kansas 66502, USA
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17
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Ballem A, Gonçalves S, Garcia-Meniño I, Flament-Simon SC, Blanco JE, Fernandes C, Saavedra MJ, Pinto C, Oliveira H, Blanco J, Almeida G, Almeida C. Prevalence and serotypes of Shiga toxin-producing Escherichia coli (STEC) in dairy cattle from Northern Portugal. PLoS One 2020; 15:e0244713. [PMID: 33382795 PMCID: PMC7774927 DOI: 10.1371/journal.pone.0244713] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 12/16/2020] [Indexed: 12/15/2022] Open
Abstract
The prevalence of Shiga toxin (Stx)-producing Escherichia coli (STEC) was determined by evaluating its presence in faecal samples from 155 heifers, and 254 dairy cows in 21 farms at North of Portugal sampled between December 2017 and June 2019. The prevalence of STEC in heifers (45%) was significantly higher than in lactating cows (16%) (p<0.05, Fisher exact test statistic value is <0.00001). A total of 133 STEC were isolated, 24 (13.8%) carried Shiga-toxin 1 (stx1) genes, 69 (39.7%) carried Shiga-toxin 2 (stx2) genes, and 40 (23%) carried both stx1 and stx2. Intimin (eae) virulence gene was detected in 29 (21.8%) of the isolates. STEC isolates belonged to 72 different O:H serotypes, comprising 40 O serogroups and 23 H types. The most frequent serotypes were O29:H12 (15%) and O113:H21 (5.2%), found in a large number of farms. Two isolates belonged to the highly virulent serotypes associated with human disease O157:H7 and O26:H11. Many other bovine STEC serotypes founded in this work belonged to serotypes previously described as pathogenic to humans. Thus, this study highlights the need for control strategies that can reduce STEC prevalence at the farm level and, thus, prevent food and environmental contamination.
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Affiliation(s)
- Andressa Ballem
- National Institute for Agrarian and Veterinary Research, Vairão, Vila do Conde, Portugal
- Veterinary Science Department, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal
- Farroupilha Federal Institute, Campus of São Vicente do Sul, Rio Grande do Sul, São Vicente do Sul, Brazil
- Centre for the Research and Technology of Agro-Environmental and Biological Science, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal
- Centro de Investigação de Montanha, School of Agriculture, Polytechnic Institute of Bragança, Bragança, Portugal
| | - Soraia Gonçalves
- National Institute for Agrarian and Veterinary Research, Vairão, Vila do Conde, Portugal
| | - Isidro Garcia-Meniño
- Laboratorio de Referencia de E. coli, Department of Microbiology and Parasitology, Veterinary Faculty, University of Santiago de Compostela, Lugo, Spain
- Instituto de Investigación Sanitaria de Santiago de Compostela, Santiago de Compostela, Spain
| | - Saskia C. Flament-Simon
- Laboratorio de Referencia de E. coli, Department of Microbiology and Parasitology, Veterinary Faculty, University of Santiago de Compostela, Lugo, Spain
- Instituto de Investigación Sanitaria de Santiago de Compostela, Santiago de Compostela, Spain
| | - Jesús E. Blanco
- Laboratorio de Referencia de E. coli, Department of Microbiology and Parasitology, Veterinary Faculty, University of Santiago de Compostela, Lugo, Spain
- Instituto de Investigación Sanitaria de Santiago de Compostela, Santiago de Compostela, Spain
| | - Conceição Fernandes
- Centro de Investigação de Montanha, School of Agriculture, Polytechnic Institute of Bragança, Bragança, Portugal
| | - Maria José Saavedra
- Veterinary Science Department, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal
- Centre for the Research and Technology of Agro-Environmental and Biological Science, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal
| | - Carlos Pinto
- National Institute for Agrarian and Veterinary Research, Vairão, Vila do Conde, Portugal
| | - Hugo Oliveira
- Centre of Biological Engineering, University of Minho, Campus of Gualtar, Braga, Portugal
- * E-mail: (CA); (HO)
| | - Jorge Blanco
- Laboratorio de Referencia de E. coli, Department of Microbiology and Parasitology, Veterinary Faculty, University of Santiago de Compostela, Lugo, Spain
- Instituto de Investigación Sanitaria de Santiago de Compostela, Santiago de Compostela, Spain
| | - Gonçalo Almeida
- National Institute for Agrarian and Veterinary Research, Vairão, Vila do Conde, Portugal
| | - Carina Almeida
- National Institute for Agrarian and Veterinary Research, Vairão, Vila do Conde, Portugal
- * E-mail: (CA); (HO)
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18
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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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19
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Molecular detection of Shiga toxin-producing and antibiotic-resistant Escherichia coli isolates from buffaloes in southwest of Iran. Trop Anim Health Prod 2019; 51:1725-1736. [PMID: 30915604 DOI: 10.1007/s11250-019-01869-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2018] [Accepted: 03/15/2019] [Indexed: 12/18/2022]
Abstract
Three hundred fifteen bacteriological samples were obtained from feces and both external and visceral cavity surfaces of carcasses of 105 healthy buffalo slaughtered in southwest of Iran. Confirmed Escherichia coli isolates were examined for antimicrobial resistance phenotypically and were screened for stx1, stx2, and eae genes and their subtypes and assessment of antimicrobial resistance genes by regular PCR and RFLP techniques. One hundred forty-five E. coli were isolated from feces (96 isolates) and external (37) and internal (12) surfaces of carcasses. Results showed that the prevalence of STEC, EPEC, and EHEC pathotypes was 2.8%, 0.7%, and 0.7% respectively. Among 6 (4.13%) positive isolates for examined genes, 4 (2.8%) isolates were positive for stx1, 3 (2.1%) for stx2, and 2 (1.4%) for eae gene. The detected genes were classified into stx1a (4 isolates), stx2a, stx2b, stx2c, eae-β, and unknown subtypes. The most prevalent antibiotic resistance gene was sulII (11.03%). The tetB, qnrB, floR, blaTEM, blaSHV, and aadA genes were found to a lesser extent, and all isolates were negative for blaCTX-15, blaOXA, aac(3)-I, tetA, cat1, qnrA, sulI, dhfrI, and dhfrV genes. Twelve combination patterns of antibiotic-resistant genes were observed. Maximum phenotypically resistance rate was against doxycycline (91.83%), and the minimum was against ceftazidime and florfenicol (2.75%). E. coli isolates from feces and carcasses of slaughtered buffalo can be considered a mild reservoir for stx and eae genes. However, healthy buffaloes could be considered a potential reservoir of multiple antibiotic resistance genes in E. coli isolates.
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20
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Wang LYR, Jokinen CC, Laing CR, Johnson RP, Ziebell K, Gannon VPJ. Multi-Year Persistence of Verotoxigenic Escherichia coli (VTEC) in a Closed Canadian Beef Herd: A Cohort Study. Front Microbiol 2018; 9:2040. [PMID: 30233526 PMCID: PMC6127291 DOI: 10.3389/fmicb.2018.02040] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 08/13/2018] [Indexed: 01/12/2023] Open
Abstract
In this study, fecal samples were collected from a closed beef herd in Alberta, Canada from 2012 to 2015. To limit serotype bias, which was observed in enrichment broth cultures, Verotoxigenic Escherichia coli (VTEC) were isolated directly from samples using a hydrophobic grid-membrane filter verotoxin immunoblot assay. Overall VTEC isolation rates were similar for three different cohorts of yearling heifers on both an annual (68.5 to 71.8%) and seasonal basis (67.3 to 76.0%). Across all three cohorts, O139:H19 (37.1% of VTEC-positive samples), O22:H8 (15.8%) and O?(O108):H8 (15.4%) were among the most prevalent serotypes. However, isolation rates for serotypes O139:H19, O130:H38, O6:H34, O91:H21, and O113:H21 differed significantly between cohort-years, as did isolation rates for some serotypes within a single heifer cohort. There was a high level of VTEC serotype diversity with an average of 4.3 serotypes isolated per heifer and 65.8% of the heifers classified as "persistent shedders" of VTEC based on the criteria of >50% of samples positive and ≥4 consecutive samples positive. Only 26.8% (90/336) of the VTEC isolates from yearling heifers belonged to the human disease-associated seropathotypes A (O157:H7), B (O26:H11, O111:NM), and C (O22:H8, O91:H21, O113:H21, O137:H41, O2:H6). Conversely, seropathotypes B (O26:NM, O111:NM) and C (O91:H21, O2:H29) strains were dominant (76.0%, 19/25) among VTEC isolates from month-old calves from this herd. Among VTEC from heifers, carriage rates of vt1, vt2, vt1+vt2, eae, and hlyA were 10.7, 20.8, 68.5, 3.9, and 88.7%, respectively. The adhesin gene saa was present in 82.7% of heifer strains but absent from all of 13 eae+ve strains (from serotypes/intimin types O157:H7/γ1, O26:H11/β1, O111:NM/θ, O84:H2/ζ, and O182:H25/ζ). Phylogenetic relationships inferred from wgMLST and pan genome-derived core SNP analysis showed that strains clustered by phylotype and serotype. Further, VTEC strains of the same serotype usually shared the same suite of antibiotic resistance and virulence genes, suggesting the circulation of dominant clones within this distinct herd. This study provides insight into the diverse and dynamic nature of VTEC populations within groups of cattle and points to a broad spectrum of human health risks associated with these E. coli strains.
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Affiliation(s)
- Lu Ya Ruth Wang
- National Microbiology Laboratory, Public Health Agency of Canada, Lethbridge, AB, Canada
| | | | - Chad R Laing
- National Microbiology Laboratory, Public Health Agency of Canada, Lethbridge, AB, Canada
| | - Roger P Johnson
- National Microbiology Laboratory, Public Health Agency of Canada, Guelph, ON, Canada
| | - Kim Ziebell
- National Microbiology Laboratory, Public Health Agency of Canada, Guelph, ON, Canada
| | - Victor P J Gannon
- National Microbiology Laboratory, Public Health Agency of Canada, Lethbridge, AB, Canada
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21
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Stromberg ZR, Lewis GL, Schneider LG, Erickson GE, Patel IR, Smith DR, Moxley RA. Culture-Based Quantification with Molecular Characterization of Non-O157 and O157 Enterohemorrhagic Escherichia coli Isolates from Rectoanal Mucosal Swabs of Feedlot Cattle. Foodborne Pathog Dis 2017; 15:26-32. [PMID: 29022742 DOI: 10.1089/fpd.2017.2326] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) strains are foodborne pathogens carried in the intestinal tracts of ruminants and shed in the feces. High concentrations (≥104 colony-forming units [CFU]/g) of EHEC in cattle feces are associated with contamination of hides, and subsequently, carcasses and beef. Several studies using agar media have quantified O157 but few have quantified non-O157 EHEC in samples from cattle. Thus, the objective of this study was to determine the concentration of O157 and non-O157 EHEC in cattle, and to characterize the associated EHEC isolates for their virulence potential. Two hundred feedlot steers were sampled by rectoanal mucosal swab (RAMS) every 35 days over four sampling periods, and a spiral plating method using modified Possé differential agar was used to quantify EHEC organisms in these samples. Bacterial colonies from agar plates were tested by multiplex PCR for Shiga toxin and intimin genes (stx and eae, respectively), and confirmed EHEC isolates (i.e., positive for both stx and eae) were serotyped and characterized for virulence genes using a microarray. Organisms detected in this study included O26, O101, O103, O109, O121, O145, O157, and O177 EHEC, with all except O121 quantifiable and measuring within a range from 9.0 × 102 to 3.0 × 105 CFU/g of RAMS sample. Organisms of the same EHEC serogroup were not detected in quantifiable concentrations from a single animal more than once. EHEC organisms most commonly detected at quantifiable levels were O26, O157, and O177. Interestingly, O26 EHEC isolates tested negative for stx1 but positive for stx2a. High concentrations of EHEC were detected in 11 (5.5%) of the steers at least once over the sampling period. These results indicate that in addition to O157, non-O157 EHEC are transiently present in high concentrations in the rectoanal mucosal region of cattle.
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Affiliation(s)
- Zachary R Stromberg
- 1 School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln , Lincoln, Nebraska
| | - Gentry L Lewis
- 1 School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln , Lincoln, Nebraska
| | - Liesel G Schneider
- 2 College of Veterinary Medicine, Mississippi State University , Mississippi State, Mississippi
| | - Galen E Erickson
- 3 Department of Animal Science, University of Nebraska-Lincoln , Lincoln, Nebraska
| | - Isha R Patel
- 4 Division of Molecular Biology, Office of Applied Research and Safety Assessment, Center for Food Safety and Applied Nutrition , United States Food and Drug Administration, Laurel, Maryland
| | - David R Smith
- 2 College of Veterinary Medicine, Mississippi State University , Mississippi State, Mississippi
| | - Rodney A Moxley
- 1 School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln , Lincoln, Nebraska
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