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Lee W, Ha J, Choi J, Jung Y, Kim E, An ES, Kim SH, Shin H, Ryu S, Kim SH, Kim HY. Genetic and virulence characteristics of hybrid Shiga toxin-producing and atypical enteropathogenic Escherichia coli strains isolated in South Korea. Front Microbiol 2024; 15:1398262. [PMID: 38812694 PMCID: PMC11133561 DOI: 10.3389/fmicb.2024.1398262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2024] [Accepted: 04/29/2024] [Indexed: 05/31/2024] Open
Abstract
Introduction The predominant hybrid pathogenic E. coli, enterohemorrhagic E. coli (EHEC), combines characteristics of Shiga toxin-producing E. coli (STEC) and enteropathogenic E. coli (EPEC), contributing to global outbreaks with severe symptoms including fatal consequences. Since EHEC infection was designated as a notifiable disease in 2000 in South Korea, around 2000 cases have been reported, averaging approximately 90 cases annually. Aim In this work, genome-based characteristic analysis and cell-based assay of hybrid STEC/aEPEC strains isolated from livestock feces, animal source foods, and water in South Korea was performed. Methods To identify the virulence and antimicrobial resistance genes, determining the phylogenetic position of hybrid STEC/aEPEC strains isolated in South Korea, a combination of real-time PCR and whole-genome sequencing (WGS) was used. Additionally, to assess the virulence of the hybrid strains and compare them with genomic characterization, we performed a cell cytotoxicity and invasion assays. Results The hybrid STEC/aEPEC strains harbored stx and eae genes, encoding Shiga toxins and E. coli attachment/effacement related protein of STEC and EPEC, respectively. Furthermore, all hybrid strains harbored plasmid-carried enterohemolysin(ehxCABD), a key virulence factor in prevalent pathogenic E. coli infections, such as diarrheal disease and hemolytic-uremic syndrome (HUS). Genome-wide phylogenetic analysis revealed a close association between all hybrid strains and specific EPEC strains, suggesting the potential acquisition of Stx phages during STEC/aEPEC hybrid formation. Some hybrid strains showed cytotoxic activity against HeLa cells and invasive properties against epithelial cells. Notably, all STEC/aEPEC hybrids with sequence type (ST) 1,034 (n = 11) exhibited higher invasiveness than those with E2348/69. This highlights the importance of investigating potential correlations between STs and virulence characteristics of E. coli hybrid strains. Conclusion Through genome-based characterization, we confirmed that the hybrid STEC/aEPEC strains are likely EPEC strains that have acquired STEC virulence genes via phage. Furthermore, our results emphasize the potential increased danger to humans posed by hybrid STEC/aEPEC strains isolated in South Korea, containing both stx and eaeA, compared to STEC or EPEC alone.
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Affiliation(s)
- Woojung Lee
- Division of Food Microbiology, National Institute of Food and Drug Safety Evaluation, Ministry of Food and Drug Safety, Cheongju, Republic of Korea
- Institute of Life Sciences & Resources and Department of Food Science and Biotechnology, Kyung Hee University, Yongin, Republic of Korea
| | - Jina Ha
- Division of Food Microbiology, National Institute of Food and Drug Safety Evaluation, Ministry of Food and Drug Safety, Cheongju, Republic of Korea
| | - Jaehyun Choi
- Division of Food Microbiology, National Institute of Food and Drug Safety Evaluation, Ministry of Food and Drug Safety, Cheongju, Republic of Korea
| | - Yewon Jung
- Department of Food and Animal Biotechnology, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, Republic of Korea
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea
| | - Eiseul Kim
- Institute of Life Sciences & Resources and Department of Food Science and Biotechnology, Kyung Hee University, Yongin, Republic of Korea
| | - Eun Sook An
- Division of Food Microbiology, National Institute of Food and Drug Safety Evaluation, Ministry of Food and Drug Safety, Cheongju, Republic of Korea
| | - Seung Hwan Kim
- Division of Food Microbiology, National Institute of Food and Drug Safety Evaluation, Ministry of Food and Drug Safety, Cheongju, Republic of Korea
| | - Hakdong Shin
- Department of Biotechnology, and Carbohydrate Bioproduct Research Center, Sejong University, Seoul, Republic of Korea
| | - Sangryeol Ryu
- Department of Food and Animal Biotechnology, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, Republic of Korea
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea
- Center for Food and Bioconvergence, Seoul National University, Seoul, Republic of Korea
| | - Soon Han Kim
- Division of Food Microbiology, National Institute of Food and Drug Safety Evaluation, Ministry of Food and Drug Safety, Cheongju, Republic of Korea
| | - Hae-Yeong Kim
- Institute of Life Sciences & Resources and Department of Food Science and Biotechnology, Kyung Hee University, Yongin, Republic of Korea
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Ren K, Duan M, Su T, Ying D, Wu S, Wang Z, Duan N. A colorimetric and SERS dual-mode aptasensor for the detection of Shiga toxin type II based on Mn/Fe-MIL(53)@AuNSs. Talanta 2024; 270:125636. [PMID: 38211356 DOI: 10.1016/j.talanta.2024.125636] [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: 12/05/2023] [Revised: 12/29/2023] [Accepted: 01/04/2024] [Indexed: 01/13/2024]
Abstract
Shiga toxin type II (Stx2), the major virulence component of enterohemorrhagic Escherichia coli, is strongly associated with the life-threatening hemolytic uremic syndrome thus posing a substantial risk to food safety and human health. In this work, a dual-mode aptasensor with colorimetric and surface-enhanced Raman scattering was developed for Stx2 specific detection based on noble metal nanoparticles and Raman reporter loaded metal-organic framework (Mn/Fe-MIL(53)@AuNSs-MBA). The Mn/Fe-MIL(53)@AuNSs could catalyze the H2O2-mediated oxidation of 3,3',5,5'-tetramethylbenzidine (TMB), thereby enabling visual detection. Meanwhile, the SERS signal from MBA can be enhanced by the decorated AuNSs. Under optimal conditions, a linear range of 0.05-500 ng/mL with limit of detection (LOD) of 26 pg/mL was achieved in colorimetric mode and a linear range of 5-1000 ng/mL with LOD of 0.82 ng/mL in SERS mode, in which the dual-mode results complement each other, widening the linear range, increasing the accuracy and reliability of the detection. The method was further applied to the detection of Stx2 in milk with average recovery of 101.1 %, demonstrating its superior potential for bacterial toxin monitoring.
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Affiliation(s)
- Kexin Ren
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
| | - Mengxia Duan
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
| | - Tingting Su
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
| | - Dichen Ying
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
| | - Shijia Wu
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi, 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Zhouping Wang
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi, 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Nuo Duan
- State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi, 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi, 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China.
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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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Harada T, Wakabayashi Y, Seto K, Lee K, Iyoda S, Kawatsu K. Real-time PCR assays to detect 10 Shiga toxin subtype (Stx1a, Stx1c, Stx1d, Stx2a, Stx2b, Stx2c, Stx2d, Stx2e, Stx2f, and Stx2g) genes. Diagn Microbiol Infect Dis 2023; 105:115874. [PMID: 36529020 DOI: 10.1016/j.diagmicrobio.2022.115874] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 11/03/2022] [Accepted: 11/26/2022] [Indexed: 12/03/2022]
Abstract
To develop subtyping methods for Shiga toxin (Stx)1a, Stx1c, Stx1d, Stx2a, Stx2b, Stx2c, Stx2d, Stx2e, Stx2f, and Stx2g genes for epidemiological analyses of Shiga toxin-producing Escherichia coli (STEC), we developed 10 simplex real-time polymerase chain reaction (PCR) assays with reference to 284 valid stx sequences and evaluated their specificity and quantitative accuracy using STEC and non-STEC isolates and recombinant plasmids, respectively. Three stx1 and 5 stx2 subtype genes, except for stx2c and stx2d, were detected with high specificity using STEC isolates. However, some stx2a sequences potentially being close to both Stx2a and Stx2d cluster in neighbor-joining cluster analysis were positive for stx2a and stx2d by real-time PCR. For the stx2c assay, the number of real-time PCR cycles was reduced to avoid unnecessary false-positive results. Based on these considerations, the real-time PCR assays developed here might aid epidemiological investigations of infections or outbreaks caused by STEC harboring any of the stx subtype genes.
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Affiliation(s)
- Tetsuya Harada
- Division of Microbiology, Osaka Institute of Public Health, Osaka, Japan.
| | - Yuki Wakabayashi
- Division of Microbiology, Osaka Institute of Public Health, Osaka, Japan
| | - Kazuko Seto
- Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Kenichi Lee
- Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Sunao Iyoda
- Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Kentaro Kawatsu
- Division of Microbiology, Osaka Institute of Public Health, Osaka, Japan
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Berenger BM, Chui L, Ferrato C, Lloyd T, Li V, Pillai DR. Performance of four commercial real-time PCR assays for the detection of bacterial enteric pathogens in clinical samples. Int J Infect Dis 2021; 114:195-201. [PMID: 34700003 DOI: 10.1016/j.ijid.2021.10.035] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 10/19/2021] [Accepted: 10/20/2021] [Indexed: 10/20/2022] Open
Abstract
OBJECTIVES Many laboratories use culture-independent diagnostic tests for bacterial gastroenteritis (ie. real-time polymerase chain reaction [RT-PCR]) instead of culture because of better sensitivity, automation, and faster turnaround times. To address some gaps in initial evaluations and lack of intraassay comparisons for many commercial RT-PCRs we compared the ability of four commercially available RT-PCR tests (Ridagene, Fast Track Diagnostics, BD Max, and Prodesse Progastro) to detect five major bacterial enteric pathogens: Campylobacter, Salmonella, Shiga-toxin producing E. coli (STEC), Shigella and Yersinia. METHODS Clinical stool specimens and contrived samples comprising commonly circulating species, serotypes, biovars and/or toxin subtypes were used for the comparison. RESULTS Concordance rates for RT-PCR and culture using culture positive and negative clinical stools were greater than 90% for Campylobacter (97.5-100%), Salmonella (97.5-100%), Shigella (100%) and STEC (90-100%). However, the agreement between RT-PCR and culture for Y. enteroccolitica ranged from 70-90%. For the contrived sample set, stx2f was detected by only 1 of 4 assays. Of note, no assay could detect Yersinia non-enterocolitica and C. upsaliensis. CONCLUSIONS Depending on the prevalence of certain stx sub-types, Yersinia and Campylobacter species in a laboratory's jurisdiction, culture methods remain critical for the detection of these pathogens without further improvement in PCR assays.
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Affiliation(s)
- Byron M Berenger
- South Sector Microbiology, Alberta Precision Laboratories, 3535 Research Road, Calgary, AB, Canada T2L 1Y1; Alberta Public Health Laboratory, Alberta Precision Laboratories, 3300 Hospital Drive NW, Calgary, AB, T2N 4W4; Department of Pathology and Laboratory Medicine, University of Calgary, 3535 Research Road, Calgary, AB, Canada T2L 1Y1.
| | - Linda Chui
- Alberta Public Health Laboratory, Alberta Precision Laboratories, 3300 Hospital Drive NW, Calgary, AB, T2N 4W4; Department of Laboratory Medicine and Pathology, University of Alberta, 116 St. and 85 Ave Edmonton, AB, Canada T6G 2R3.
| | - Christina Ferrato
- Alberta Public Health Laboratory, Alberta Precision Laboratories, 3300 Hospital Drive NW, Calgary, AB, T2N 4W4.
| | - Tracie Lloyd
- South Sector Microbiology, Alberta Precision Laboratories, 3535 Research Road, Calgary, AB, Canada T2L 1Y1.
| | - Vincent Li
- Alberta Public Health Laboratory, Alberta Precision Laboratories, 3300 Hospital Drive NW, Calgary, AB, T2N 4W4.
| | - Dylan R Pillai
- South Sector Microbiology, Alberta Precision Laboratories, 3535 Research Road, Calgary, AB, Canada T2L 1Y1; Department of Pathology and Laboratory Medicine, University of Calgary, 3535 Research Road, Calgary, AB, Canada T2L 1Y1; Department of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, AB, Canada T2N 4N1.
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Shan S, Huang Y, Huang Z, Long Z, Liu C, Zhao X, Xing K, Xiao X, Liu J, Huang Y, Lai W, Liu D. Detection of stx1 and stx2 and subtyping of Shiga toxin-producing Escherichia coli using asymmetric PCR combined with lateral flow immunoassay. Food Control 2021. [DOI: 10.1016/j.foodcont.2021.108051] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Abstract
PURPOSE OF REVIEW Several types of Escherichia coli cause acute diarrhea in humans and are responsible for a large burden of disease globally. The purpose of this review is to summarize diarrheagenic Escherichia coli (DEC) pathotype definitions and discuss existing and emerging molecular, genomic, and gut microbiome methods to detect, define, and study DEC pathotypes. RECENT FINDINGS DEC pathotypes are currently diagnosed by molecular detection of unique virulence genes. However, some pathotypes have defied coherent molecular definitions because of imperfect gene targets, and pathotype categories are complicated by hybrid strains and isolation of pathotypes from asymptomatic individuals. Recent progress toward more efficient, sensitive, and multiplex DEC pathotype detection has been made using emerging PCR-based technologies. Genomics and gut microbiome detection methods continue to advance rapidly and are contributing to a better understanding of DEC pathotype diversity and functional potential. SUMMARY DEC pathotype categorizations and detection methods are useful but imperfect. The implementation of molecular and sequence-based methods and well designed epidemiological studies will continue to advance understanding of DEC pathotypes. Additional emphasis is needed on sequencing DEC genomes from regions of the world where they cause the most disease and from the pathotypes that cause the greatest burden of disease globally.
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Lisboa LF, Szelewicki J, Lin A, Latonas S, Li V, Zhi S, Parsons BD, Berenger B, Fathima S, Chui L. Epidemiology of Shiga Toxin-Producing Escherichia coli O157 in the Province of Alberta, Canada, 2009-2016. Toxins (Basel) 2019; 11:toxins11100613. [PMID: 31652648 PMCID: PMC6832344 DOI: 10.3390/toxins11100613] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 10/16/2019] [Accepted: 10/19/2019] [Indexed: 11/19/2022] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) infections are the product of the interaction between bacteria, phages, animals, humans, and the environment. In the late 1980s, Alberta had one of the highest incidences of STEC infections in North America. Herein, we revisit and contextualize the epidemiology of STEC O157 human infections in Alberta for the period 2009–2016. STEC O157 infections were concentrated in large urban centers, but also in rural areas with high cattle density. Hospitalization was often required when the Shiga toxin genotype stx2a stx2c was involved, however, only those aged 60 years or older and infection during spring months (April to June) independently predicted that need. Since the late 1980s, the rate of STEC O157-associated hemolytic uremic syndrome (HUS) in Alberta has remained unchanged at 5.1%, despite a marked drop in the overall incidence of the infection. While Shiga toxin genotypes stx1a stx2c and stx2a stx2c seemed associated with HUS, only those aged under 10 years and infection during spring months were independently predictive of that complication. The complexity of the current epidemiology of STEC O157 in Alberta highlights the need for a One Health approach for further progress to be made in mitigating STEC morbidity.
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Affiliation(s)
- Luiz F Lisboa
- Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2R3, Canada.
| | - Jonas Szelewicki
- Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2R3, Canada.
| | - Alex Lin
- Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2R3, Canada.
| | - Sarah Latonas
- Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2R3, Canada.
| | - Vincent Li
- Provincial Laboratory for Public Health, Alberta Public Laboratories, Edmonton, AB T6G 2B7, Canada.
| | - Shuai Zhi
- Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2R3, Canada.
| | - Brendon D Parsons
- Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2R3, Canada.
| | - Byron Berenger
- Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2R3, Canada.
| | - Sumana Fathima
- The Ministry of Health, Government of Alberta, Edmonton, AB T5J 1S6, Canada.
| | - Linda Chui
- Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2R3, Canada.
- Provincial Laboratory for Public Health, Alberta Public Laboratories, Edmonton, AB T6G 2B7, Canada.
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Tarr GAM, Stokowski T, Shringi S, Tarr PI, Freedman SB, Oltean HN, Rabinowitz PM, Chui L. Contribution and Interaction of Shiga Toxin Genes to Escherichia coli O157:H7 Virulence. Toxins (Basel) 2019; 11:toxins11100607. [PMID: 31635282 PMCID: PMC6832461 DOI: 10.3390/toxins11100607] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 10/14/2019] [Accepted: 10/16/2019] [Indexed: 01/17/2023] Open
Abstract
Escherichia coli O157:H7 is the predominant cause of diarrhea-associated hemolytic uremic syndrome (HUS) worldwide. Its cardinal virulence traits are Shiga toxins, which are encoded by stx genes, the most common of which are stx1a, stx2a, and stx2c. The toxins these genes encode differ in their in vitro and experimental phenotypes, but the human population-level impact of these differences is poorly understood. Using Shiga toxin-encoding bacteriophage insertion typing and real-time polymerase chain reaction, we genotyped isolates from 936 E. coli O157:H7 cases and verified HUS status via chart review. We compared the HUS risk between isolates with stx2a and those with stx2a and another gene and estimated additive interaction of the stx genes. Adjusted for age and symptoms, the HUS incidence of E. coli O157:H7 containing stx2a alone was 4.4% greater (95% confidence interval (CI) −0.3%, 9.1%) than when it occurred with stx1a. When stx1a and stx2a occur together, the risk of HUS was 27.1% lower (95% CI −87.8%, −2.3%) than would be expected if interaction were not present. At the population level, temporal or geographic shifts toward these genotypes should be monitored, and stx genotype may be an important consideration in clinically predicting HUS among E. coli O157:H7 cases.
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Affiliation(s)
- Gillian A M Tarr
- Department of Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, AB T3B 6A8, Canada.
| | - Taryn Stokowski
- Department of Laboratory Medicine and Pathology, University of Alberta and Alberta Public Labs, Edmonton, AB T6G 2J2, Canada.
| | - Smriti Shringi
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA 99163, USA.
| | - Phillip I Tarr
- Division of Gastroenterology, Hepatology, and Nutrition, Washington University School of Medicine, St. Louis, MO 63110, USA.
| | - Stephen B Freedman
- Department of Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, AB T3B 6A8, Canada.
| | - Hanna N Oltean
- Washington State Department of Health, Shoreline, WA 98155, USA.
| | - Peter M Rabinowitz
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA 98195, USA.
| | - Linda Chui
- Department of Laboratory Medicine and Pathology, University of Alberta and Alberta Public Labs, Edmonton, AB T6G 2J2, Canada.
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Rapid culture-based identification of Shiga toxin-producing Escherichia coli and Shigella spp./Enteroinvasive E. coli using the eazyplex® EHEC complete assay. Eur J Clin Microbiol Infect Dis 2019; 39:151-158. [PMID: 31529306 DOI: 10.1007/s10096-019-03704-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 09/04/2019] [Indexed: 12/14/2022]
Abstract
Shiga toxin-producing Escherichia coli (STEC) and Shigella spp./enteroinvasive E. coli (EIEC) are common diarrheagenic bacteria that cause sporadic diseases and outbreaks. Clinical manifestations vary from mild symptoms to severe complications. For microbiological diagnosis, culture confirmation of a positive stool screening PCR test is challenging because of time-consuming methods for isolation of strains, wide variety of STEC pathotypes, and increased emergence of non-classical strains with unusual serotypes. Therefore, molecular assays for the rapid identification of suspect colonies growing on selective media are very useful. In this study, the performance of the newly introduced eazyplex® EHEC assay based on loop-mediated isothermal amplification (LAMP) was evaluated using 18 representative STEC and Shigella strains and 31 isolates or positive-enrichment broths that were collected from clinical stool samples following screening by BD MAX™ EBP PCR. Results were compared to real-time PCR as a reference standard. Overall, sensitivities and specificities of the eazyplex® EHEC were as follows: 94.7% and 100% for Shiga toxin 1 (stx1), 100% and 100% for stx2, 93.3% and 97.1% for intimin (eae), 100% and 100% for enterohemolysin A (ehlyA), and 100% and 100% for invasion-associated plasmid antigen H (ipaH) as Shigella spp./EIEC target, respectively. Sample preparation for LAMP took only some minutes, and the time to result of the assay ranged from 8.5 to 13 min. This study shows that eazyplex® EHEC is a very fast and easy to perform molecular assay that provides reliable results as a culture confirmation assay for the diagnosis of STEC and Shigella spp./EIEC infections.
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