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Wang L, Bai X, Ylinen E, Zhang J, Saxén H, Matussek A. Genetic Characterization of Intimin Gene ( eae) in Clinical Shiga Toxin-Producing Escherichia coli Strains from Pediatric Patients in Finland. Toxins (Basel) 2023; 15:669. [PMID: 38133173 PMCID: PMC10748226 DOI: 10.3390/toxins15120669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2023] [Revised: 11/18/2023] [Accepted: 11/22/2023] [Indexed: 12/23/2023] Open
Abstract
Shiga toxin (Stx)-producing Escherichia coli (STEC) infections cause outbreaks of severe disease in children ranging from bloody diarrhea to hemolytic uremic syndrome (HUS). The adherent factor intimin, encoded by eae, can facilitate the colonization process of strains and is frequently associated with severe disease. The purpose of this study was to examine and analyze the prevalence and polymorphisms of eae in clinical STEC strains from pediatric patients under 17 years old with and without HUS, and to assess the pathogenic risk of different eae subtypes. We studied 240 STEC strains isolated from pediatric patients in Finland with whole genome sequencing. The gene eae was present in 209 (87.1%) strains, among which 49 (23.4%) were from patients with HUS, and 160 (76.6%) were from patients without HUS. O157:H7 (126, 60.3%) was the most predominant serotype among eae-positive STEC strains. Twenty-three different eae genotypes were identified, which were categorized into five eae subtypes, i.e., γ1, β3, ε1, θ and ζ3. The subtype eae-γ1 was significantly overrepresented in strains from patients aged 5-17 years, while β3 and ε1 were more commonly found in strains from patients under 5 years. All O157:H7 strains carried eae-γ1; among non-O157 strains, strains of each serotype harbored one eae subtype. No association was observed between the presence of eae/its subtypes and HUS. However, the combination of eae-γ1+stx2a was significantly associated with HUS. In conclusion, this study demonstrated a high occurrence and genetic variety of eae in clinical STEC from pediatric patients under 17 years old in Finland, and that eae is not essential for STEC-associated HUS. However, the combination of certain eae subtypes with stx subtypes, i.e., eae-γ1+stx2a, may be used as risk predictors for the development of severe disease in children.
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Affiliation(s)
- Lei Wang
- Department of Microbiology, Division of Laboratory Medicine, Oslo University Hospital and University of Oslo, 0372 Oslo, Norway; (L.W.); (X.B.)
- Jinan Center for Disease Control and Prevention, Jinan 250021, China
| | - Xiangning Bai
- Department of Microbiology, Division of Laboratory Medicine, Oslo University Hospital and University of Oslo, 0372 Oslo, Norway; (L.W.); (X.B.)
- Department of Clinical Microbiology, Division of Laboratory Medicine, Karolinska Institutet, 141 52 Stockholm, Sweden
| | - Elisa Ylinen
- Department of Pediatric Nephrology and Transplantation, New Children’s Hospital, University of Helsinki and Helsinki University Hospital, 00029 Helsinki, Finland; (E.Y.); (H.S.)
| | - Ji Zhang
- Fonterra Research and Development Centre, Dairy Farm Road, Palmerston North 4442, New Zealand;
| | - Harri Saxén
- Department of Pediatric Nephrology and Transplantation, New Children’s Hospital, University of Helsinki and Helsinki University Hospital, 00029 Helsinki, Finland; (E.Y.); (H.S.)
| | - Andreas Matussek
- Department of Microbiology, Division of Laboratory Medicine, Oslo University Hospital and University of Oslo, 0372 Oslo, Norway; (L.W.); (X.B.)
- Department of Clinical Microbiology, Division of Laboratory Medicine, Karolinska Institutet, 141 52 Stockholm, Sweden
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Nouws S, Verhaegen B, Denayer S, Crombé F, Piérard D, Bogaerts B, Vanneste K, Marchal K, Roosens NHC, De Keersmaecker SCJ. Transforming Shiga toxin-producing Escherichia coli surveillance through whole genome sequencing in food safety practices. Front Microbiol 2023; 14:1204630. [PMID: 37520372 PMCID: PMC10381951 DOI: 10.3389/fmicb.2023.1204630] [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: 04/12/2023] [Accepted: 06/22/2023] [Indexed: 08/01/2023] Open
Abstract
Introduction Shiga toxin-producing Escherichia coli (STEC) is a gastrointestinal pathogen causing foodborne outbreaks. Whole Genome Sequencing (WGS) in STEC surveillance holds promise in outbreak prevention and confinement, in broadening STEC epidemiology and in contributing to risk assessment and source attribution. However, despite international recommendations, WGS is often restricted to assist outbreak investigation and is not yet fully implemented in food safety surveillance across all European countries, in contrast to for example in the United States. Methods In this study, WGS was retrospectively applied to isolates collected within the context of Belgian food safety surveillance and combined with data from clinical isolates to evaluate its benefits. A cross-sector WGS-based collection of 754 strains from 1998 to 2020 was analyzed. Results We confirmed that WGS in food safety surveillance allows accurate detection of genomic relationships between human cases and strains isolated from food samples, including those dispersed over time and geographical locations. Identifying these links can reveal new insights into outbreaks and direct epidemiological investigations to facilitate outbreak management. Complete WGS-based isolate characterization enabled expanding epidemiological insights related to circulating serotypes, virulence genes and antimicrobial resistance across different reservoirs. Moreover, associations between virulence genes and severe disease were determined by incorporating human metadata into the data analysis. Gaps in the surveillance system were identified and suggestions for optimization related to sample centralization, harmonizing isolation methods, and expanding sampling strategies were formulated. Discussion This study contributes to developing a representative WGS-based collection of circulating STEC strains and by illustrating its benefits, it aims to incite policymakers to support WGS uptake in food safety surveillance.
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Affiliation(s)
- Stéphanie Nouws
- Transversal Activities in Applied Genomics, Sciensano, Brussels, Belgium
- IDlab, Department of Information Technology, Ghent University—IMEC, Ghent, Belgium
| | - Bavo Verhaegen
- National Reference Laboratory for Shiga Toxin-Producing Escherichia coli (NRL STEC) and for Foodborne Outbreaks (NRL FBO), Foodborne Pathogens, Sciensano, Brussels, Belgium
| | - Sarah Denayer
- National Reference Laboratory for Shiga Toxin-Producing Escherichia coli (NRL STEC) and for Foodborne Outbreaks (NRL FBO), Foodborne Pathogens, Sciensano, Brussels, Belgium
| | - Florence Crombé
- National Reference Centre for Shiga Toxin-Producing Escherichia coli (NRC STEC), Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel, Brussels, Belgium
| | - Denis Piérard
- National Reference Centre for Shiga Toxin-Producing Escherichia coli (NRC STEC), Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel, Brussels, Belgium
| | - Bert Bogaerts
- Transversal Activities in Applied Genomics, Sciensano, Brussels, Belgium
| | - Kevin Vanneste
- Transversal Activities in Applied Genomics, Sciensano, Brussels, Belgium
| | - Kathleen Marchal
- IDlab, Department of Information Technology, Ghent University—IMEC, Ghent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
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Miyata T, Taniguchi I, Nakamura K, Gotoh Y, Yoshimura D, Itoh T, Hirai S, Yokoyama E, Ohnishi M, Iyoda S, Ogura Y, Hayashi T. Alteration of a Shiga toxin-encoding phage associated with a change in toxin production level and disease severity in Escherichia coli. Microb Genom 2023; 9:mgen000935. [PMID: 36821793 PMCID: PMC9997748 DOI: 10.1099/mgen.0.000935] [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: 08/01/2022] [Accepted: 11/21/2022] [Indexed: 02/25/2023] Open
Abstract
Among the nine clades of Shiga toxin (Stx)-producing Escherichia coli O157:H7, clade 8 is thought to be highly pathogenic, as it causes severe disease more often than other clades. Two subclades have been proposed, but there are conflicting reports on intersubclade differences in Stx2 levels, although Stx2 production is a risk factor for severe disease development. The global population structure of clade 8 has also yet to be fully elucidated. Here, we present genome analyses of a global clade 8 strain set (n =510), including 147 Japanese strains sequenced in this study. The complete genome sequences of 18 of the 147 strains were determined to perform detailed clade-wide genome analyses together with 17 publicly available closed genomes. Intraclade variations in Stx2 production level and disease severity were also re-evaluated within the phylogenetic context. Based on phylogenomic analysis, clade 8 was divided into four lineages corresponding to the previously proposed SNP genotypes (SGs): SG8_30, SG8_31A, SG8_31B and SG8_32. SG8_30 and the common ancestor of the other SGs were first separated, with SG8_31A and SG8_31B emerging from the latter and SG8_32 emerging from SG8_31B. Comparison of 35 closed genomes revealed the overall structure of chromosomes and pO157 virulence plasmids and the prophage contents to be well conserved. However, Stx2a phages exhibit notable genomic diversity, even though all are integrated into the argW locus, indicating that subtype changes in Stx2a phage occurred from the γ subtype to its variant (γ_v1) in SG8_31A and from γ to δ in SG8_31B and SG8_32 via replacement of parts or almost entire phage genomes, respectively. We further show that SG8_30 strains (all carrying γ Stx2a phages) produce significantly higher levels of Stx2 and cause severe disease more frequently than SG8_32 strains (all carrying δ Stx2a phages). Clear conclusions on SG8_31A and SG8_31B cannot be made due to the small number of strains available, but as SG8_31A (carrying γ_v1 Stx2a phages) contains strains that produce much more Stx2 than SG8_30 strains, attention should also be paid to this SG.
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Affiliation(s)
- Tatsuya Miyata
- Department of Bacteriology, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
- Department of Pediatrics, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Itsuki Taniguchi
- Department of Bacteriology, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Keiji Nakamura
- Department of Bacteriology, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Yasuhiro Gotoh
- Department of Bacteriology, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
| | - Dai Yoshimura
- School of Life Science and Technology, Tokyo Institute of Technology, Meguro, Tokyo 152-8550, Japan
| | - Takehiko Itoh
- School of Life Science and Technology, Tokyo Institute of Technology, Meguro, Tokyo 152-8550, Japan
| | - Shinichiro Hirai
- Division of Bacteriology, Chiba Prefectural Institute of Public Health, Chiba 260-8715, Japan
- Center for Emergency Preparedness and Response, National Institute of Infectious Diseases, Musashi-Murayama, Tokyo 208-0011, Japan
| | - Eiji Yokoyama
- Division of Bacteriology, Chiba Prefectural Institute of Public Health, Chiba 260-8715, Japan
| | - Makoto Ohnishi
- Department of Bacteriology I, National Institute of Infectious Diseases, Shinjuku, Tokyo 162-8640, Japan
| | - Sunao Iyoda
- Department of Bacteriology I, National Institute of Infectious Diseases, Shinjuku, Tokyo 162-8640, Japan
| | - Yoshitoshi Ogura
- Department of Bacteriology, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
- Division of Microbiology, Department of Infectious Medicine, Kurume University School of Medicine, Kurume, Fukuoka 830-0011, Japan
| | - Tetsuya Hayashi
- Department of Bacteriology, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
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Idland L, Bø-Granquist EG, Aspholm M, Lindbäck T. The Ability of Shiga Toxin-Producing Escherichia coli to Grow in Raw Cow's Milk Stored at Low Temperatures. Foods 2022; 11:3411. [PMID: 36360022 PMCID: PMC9656703 DOI: 10.3390/foods11213411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 10/19/2022] [Accepted: 10/22/2022] [Indexed: 11/16/2022] Open
Abstract
Despite the lack of scientific evidence, some consumers assert that raw milk is a natural food with nutritional and immunological properties superior to pasteurized milk. This has led to the increased popularity of unpasteurized cow milk (UPM) and disregard for the risks of being exposed to zoonotic infections. Dairy cattle are healthy carriers of Shiga toxin (Stx)-producing E. coli (STEC), and contaminated UPM has caused STEC outbreaks worldwide. The association between STEC, carrying the eae (E. coli attachment effacement) gene, and severe diseases is well-established. We have previously isolated four eae positive STEC isolates from two neighboring dairy farms in the Southeast of Norway. A whole genome analysis revealed that isolates from different farms exhibited nearly identical genetic profiles. To explore the risks associated with drinking UPM, we examined the ability of the isolates to produce Stx and their growth in UPM at different temperatures. All the isolates produced Stx and one of the isolates was able to propagate in UPM at 8 °C (p < 0.02). Altogether, these results highlight the risk for STEC infections associated with the consumption of UPM.
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Affiliation(s)
- Lene Idland
- Department of Paraclinical Sciences, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 1432 Ås, Norway
| | - Erik G. Bø-Granquist
- Department of Production Animal Clinical Sciences, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 1432 Ås, Norway
| | - Marina Aspholm
- Department of Paraclinical Sciences, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 1432 Ås, Norway
| | - Toril Lindbäck
- Department of Paraclinical Sciences, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 1432 Ås, Norway
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Ramstad SN, Wasteson Y, Lindstedt BA, Taxt AM, Bjørnholt JV, Brandal LT, Bohlin J. Characterization of Shiga Toxin 2a Encoding Bacteriophages Isolated From High-Virulent O145:H25 Shiga Toxin-Producing Escherichia coli. Front Microbiol 2021; 12:728116. [PMID: 34566932 PMCID: PMC8456039 DOI: 10.3389/fmicb.2021.728116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Accepted: 07/19/2021] [Indexed: 11/20/2022] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) may cause severe disease mainly due to the ability to produce Shiga toxins (Stx) encoded on bacteriophages. In Norway, more than 30% of the reported cases with STEC O145:H25 develop hemolytic uremic syndrome (HUS), and most cases, with known travel history, acquired the infection domestically. To describe phage characteristics associated with high virulence, we extracted the Stx2a phage sequences from eight clinical Norwegian O145:H25 STEC to conduct in-depth molecular characterization using long and short read sequencing. The Stx2a phages were annotated, characterized, and compared with previously published Stx2a phages isolated from STEC of different serotypes. The Norwegian O145:H25 Stx2a phages showed high sequence identity (>99%) with 100% coverage. The Stx2a phages were located at the integration site yciD, were approximately 45 kbp long, and harbored several virulence-associated genes, in addition to stx2a, such as nanS and nleC. We observed high sequence identity (>98%) and coverage (≥94%) between Norwegian O145:H25 Stx2a phages and publicly available Stx2a phages from O145:H25 and O145:H28 STEC, isolated from HUS cases in the USA and a hemorrhagic diarrhea case from Japan, respectively. However, low similarity was seen when comparing the Norwegian O145:H25 Stx2a phage to Stx2a phages from STEC of other serotypes. In all the Norwegian O145:H25 STEC, we identified a second phage or remnants of a phage (a shadow phage, 61 kbp) inserted at the same integration site as the Stx2a phage. The shadow phage shared similarity with the Stx2a phage, but lacked stx2a and harbored effector genes not present in the Stx2a phage. We identified a conserved Stx2a phage among the Norwegian O145:H25 STEC that shared integration site with a shadow phage in all isolates. Both phage and shadow phage harbored several virulence-associated genes that may contribute to the increased pathogenicity of O145:H25 STEC.
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Affiliation(s)
- Silje N Ramstad
- Department of Microbiology, Division of Laboratory Medicine, Oslo University Hospital, Oslo, Norway.,Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Yngvild Wasteson
- Department of Paraclinical Sciences, Norwegian University of Life Sciences, Oslo, Norway
| | - Bjørn-Arne Lindstedt
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Arne M Taxt
- Department of Microbiology, Division of Laboratory Medicine, Oslo University Hospital, Oslo, Norway.,Department of Infectious Diseases and Prevention, Norwegian Institute of Public Health, Oslo, Norway
| | - Jørgen V Bjørnholt
- Department of Microbiology, Division of Laboratory Medicine, Oslo University Hospital, Oslo, Norway.,Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Lin T Brandal
- Division of Infection Control and Environmental Health, Norwegian Institute of Public Health, Oslo, Norway.,ECDC Fellowship Programme, Public Health Microbiology Path (EUPHEM), European Centre for Disease Prevention and Control (ECDC), Solna, Sweden
| | - Jon Bohlin
- Division of Infection Control and Environmental Health, Norwegian Institute of Public Health, Oslo, Norway
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6
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Hua Y, Bai X, Zhang J, Jernberg C, Chromek M, Hansson S, Frykman A, Yang X, Xiong Y, Wan C, Matussek A. Molecular characteristics of eae-positive clinical Shiga toxin-producing Escherichia coli in Sweden. Emerg Microbes Infect 2020; 9:2562-2570. [PMID: 33179570 PMCID: PMC7733975 DOI: 10.1080/22221751.2020.1850182] [Citation(s) in RCA: 13] [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: 08/22/2020] [Accepted: 11/08/2020] [Indexed: 12/19/2022]
Abstract
Shiga toxin (Stx)-producing Escherichia coli (STEC) can cause a wide range of symptoms from asymptomatic carriage, mild diarrhea to bloody diarrhea (BD) and hemolytic uremic syndrome (HUS). Intimin, encoded by the eae gene, also plays a critical role in STEC pathogenesis. Herein, we investigated the prevalence and genetic diversity of eae among clinical STEC isolates from patients with diarrhea, BD, HUS as well as from asymptomatic STEC-positive individuals in Sweden with whole-genome sequencing. We found that 173 out of 239 (72.4%) of clinical STEC strains were eae positive. Six eae subtypes (ϵ1, γ1, β3, θ, ζ and ρ) were identified eae and its subtype γ1 were significantly overrepresented in O157:H7 strains isolated from BD and HUS patients. ϵ1 was associated with O121:H19 and O103:H2 strains, and β3 to O26:H11 strains. The combination of eae subtype γ1 and stx subtype (stx 2 or stx 1+stx 2) is more likely to cause severe disease, suggesting the possibility of using eae genotypes in risk assessment of STEC infection. In summary, this study demonstrated a high prevalence of eae in clinical STEC strains and considerable genetic diversity of eae in STEC strains in Sweden from 1994 through 2018, and revealed association between eae subtypes and disease severity.
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Affiliation(s)
- Ying Hua
- Department of Microbiology, School of Public Health, Southern Medical University, Guangzhou, People’s Republic of China
- Division of Clinical Microbiology, Department of Laboratory Medicine, Karolinska Institutet, Huddinge, Sweden
| | - Xiangning Bai
- Division of Infectious Diseases, Department of Medicine Huddinge, Karolinska Institutet, Huddinge, Sweden
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
| | - Ji Zhang
- mEpiLab, School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | | | - Milan Chromek
- Division of Pediatrics, Department of Clinical Science, Intervention and Technology, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden
| | - Sverker Hansson
- Department of Pediatrics, Queen Silvia Children's Hospital, Sahlgrenska University Hospital, Gothenburg, Sweden
- Department of Pediatrics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Anne Frykman
- Department of Pediatrics, Queen Silvia Children's Hospital, Sahlgrenska University Hospital, Gothenburg, Sweden
- Department of Pediatrics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Xi Yang
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
| | - Yanwen Xiong
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
| | - Chengsong Wan
- Department of Microbiology, School of Public Health, Southern Medical University, Guangzhou, People’s Republic of China
| | - Andreas Matussek
- Division of Clinical Microbiology, Department of Laboratory Medicine, Karolinska Institutet, Huddinge, Sweden
- Laboratory Medicine, Jönköping Region County, Jönköping, Sweden
- Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
- Division of Laboratory Medicine, Oslo University Hospital, Oslo, Norway
- Division of Laboratory Medicine, Institute of Clinical Medicine, University of Oslo, Oslo, Norway
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A Toxic Environment: a Growing Understanding of How Microbial Communities Affect Escherichia coli O157:H7 Shiga Toxin Expression. Appl Environ Microbiol 2020; 86:AEM.00509-20. [PMID: 32358004 DOI: 10.1128/aem.00509-20] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) strains, including E. coli O157:H7, cause severe illness in humans due to the production of Shiga toxin (Stx) and other virulence factors. Because Stx is coregulated with lambdoid prophage induction, its expression is especially susceptible to environmental cues. Infections with Stx-producing E. coli can be difficult to model due to the wide range of disease outcomes: some infections are relatively mild, while others have serious complications. Probiotic organisms, members of the gut microbiome, and organic acids can depress Stx production, in many cases by inhibiting the growth of EHEC strains. On the other hand, the factors currently known to amplify Stx act via their effect on the stx-converting phage. Here, we characterize two interactive mechanisms that increase Stx production by O157:H7 strains: first, direct interactions with phage-susceptible E. coli, and second, indirect amplification by secreted factors. Infection of susceptible strains by the stx-converting phage can expand the Stx-producing population in a human or animal host, and phage infection has been shown to modulate virulence in vitro and in vivo Acellular factors, particularly colicins and microcins, can kill O157:H7 cells but may also trigger Stx expression in the process. Colicins, microcins, and other bacteriocins have diverse cellular targets, and many such molecules remain uncharacterized. The identification of additional Stx-amplifying microbial interactions will improve our understanding of E. coli O157:H7 infections and help elucidate the intricate regulation of pathogenicity in EHEC strains.
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Vitamin K Analogs Influence the Growth and Virulence Potential of Enterohemorrhagic Escherichia coli. Appl Environ Microbiol 2020; 86:AEM.00583-20. [PMID: 32769190 DOI: 10.1128/aem.00583-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 07/19/2020] [Indexed: 02/06/2023] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) causes serious foodborne disease worldwide. It produces the very potent Shiga toxin 2 (Stx2). The Stx2-encoding genes are located on a prophage, and production of the toxin is linked to the synthesis of Stx phages. There is, currently, no good treatment for EHEC infections, as antibiotics may trigger lytic cycle activation of the phages and increased Stx production. This study addresses how four analogs of vitamin K, phylloquinone (K1), menaquinone (K2), menadione (K3), and menadione sodium bisulfite (MSB), influence growth, Stx2-converting phage synthesis, and Stx2 production by the EHEC O157:H7 strain EDL933. Menadione and MSB conferred a concentration-dependent negative effect on bacterial growth, while phylloquinone or menaquinone had little and no effect on bacterial growth, respectively. All four vitamin K analogs affected Stx2 phage production negatively in uninduced cultures and in cultures induced with either hydrogen peroxide (H2O2), ciprofloxacin, or mitomycin C. Menadione and MSB reduced Stx2 production in cultures induced with either H2O2 or ciprofloxacin. MSB also had a negative effect on Stx2 production in two other EHEC isolates tested. Phylloquinone and menaquinone had, on the other hand, variable and concentration-dependent effects on Stx2 production. MSB, which conferred the strongest inhibitory effect on both Stx2 phage and Stx2 production, improved the growth of EHEC in the presence of H2O2 and ciprofloxacin, which could be explained by the reduced uptake of ciprofloxacin into the bacterial cell. Together, the data suggest that vitamin K analogs have a growth- and potential virulence-reducing effect on EHEC, which could be of therapeutic interest.IMPORTANCE Enterohemorrhagic E. coli (EHEC) can cause serious illness and deaths in humans by producing toxins that can severely damage our intestines and kidneys. There is currently no optimal treatment for EHEC infections, as antibiotics can worsen disease development. Consequently, the need for new treatment options is urgent. Environmental factors in our intestines can affect the virulence of EHEC and help our bodies fight EHEC infections. The ruminant intestine, the main reservoir for EHEC, contains high levels of vitamin K, but the levels are variable in humans. This study shows that vitamin K analogs can inhibit the growth of EHEC and/or production of its main virulence factor, the Shiga toxin. They may also inhibit the spreading of the Shiga toxin encoding bacteriophage. Our findings indicate that vitamin K analogs have the potential to suppress the development of serious disease caused by EHEC.
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Buytaers FE, Saltykova A, Denayer S, Verhaegen B, Vanneste K, Roosens NHC, Piérard D, Marchal K, De Keersmaecker SCJ. A Practical Method to Implement Strain-Level Metagenomics-Based Foodborne Outbreak Investigation and Source Tracking in Routine. Microorganisms 2020; 8:E1191. [PMID: 32764329 PMCID: PMC7463776 DOI: 10.3390/microorganisms8081191] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 07/31/2020] [Accepted: 08/01/2020] [Indexed: 12/13/2022] Open
Abstract
The management of a foodborne outbreak depends on the rapid and accurate identification of the responsible food source. Conventional methods based on isolation of the pathogen from the food matrix and target-specific real-time polymerase chain reactions (qPCRs) are used in routine. In recent years, the use of whole genome sequencing (WGS) of bacterial isolates has proven its value to collect relevant information for strain characterization as well as tracing the origin of the contamination by linking the food isolate with the patient's isolate with high resolution. However, the isolation of a bacterial pathogen from food matrices is often time-consuming and not always successful. Therefore, we aimed to improve outbreak investigation by developing a method that can be implemented in reference laboratories to characterize the pathogen in the food vehicle without its prior isolation and link it back to human cases. We tested and validated a shotgun metagenomics approach by spiking food pathogens in specific food matrices using the Shiga toxin-producing Escherichia coli (STEC) as a case study. Different DNA extraction kits and enrichment procedures were investigated to obtain the most practical workflow. We demonstrated the feasibility of shotgun metagenomics to obtain the same information as in ISO/TS 13136:2012 and WGS of the isolate in parallel by inferring the genome of the contaminant and characterizing it in a shorter timeframe. This was achieved in food samples containing different E. coli strains, including a combination of different STEC strains. For the first time, we also managed to link individual strains from a food product to isolates from human cases, demonstrating the power of shotgun metagenomics for rapid outbreak investigation and source tracking.
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Affiliation(s)
- Florence E. Buytaers
- Transversal activities in Applied Genomics, Sciensano, 1050 Brussels, Belgium; (F.E.B.); (A.S.); (K.V.); (N.H.C.R.)
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9000 Ghent, Belgium;
| | - Assia Saltykova
- Transversal activities in Applied Genomics, Sciensano, 1050 Brussels, Belgium; (F.E.B.); (A.S.); (K.V.); (N.H.C.R.)
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9000 Ghent, Belgium;
| | - Sarah Denayer
- National Reference Laboratory for Shiga Toxin-Producing Escherichia coli (NRL STEC), Foodborne Pathogens, Sciensano, 1050 Brussels, Belgium; (S.D.); (B.V.)
| | - Bavo Verhaegen
- National Reference Laboratory for Shiga Toxin-Producing Escherichia coli (NRL STEC), Foodborne Pathogens, Sciensano, 1050 Brussels, Belgium; (S.D.); (B.V.)
| | - Kevin Vanneste
- Transversal activities in Applied Genomics, Sciensano, 1050 Brussels, Belgium; (F.E.B.); (A.S.); (K.V.); (N.H.C.R.)
| | - Nancy H. C. Roosens
- Transversal activities in Applied Genomics, Sciensano, 1050 Brussels, Belgium; (F.E.B.); (A.S.); (K.V.); (N.H.C.R.)
| | - Denis Piérard
- National Reference Center for Shiga Toxin-Producing Escherichia coli (NRC STEC), Department of Microbiology and Infection Control, Universitair Ziekenhuis Brussel (UZ Brussel), Vrije Universiteit Brussel (VUB), 1090 Brussels, Belgium;
| | - Kathleen Marchal
- Department of Plant Biotechnology and Bioinformatics, Ghent University, 9000 Ghent, Belgium;
- Department of Information Technology, IDlab, IMEC, Ghent University, 9000 Ghent, Belgium
- Department of Genetics, University of Pretoria, 0001 Pretoria, South Africa
| | - Sigrid C. J. De Keersmaecker
- Transversal activities in Applied Genomics, Sciensano, 1050 Brussels, Belgium; (F.E.B.); (A.S.); (K.V.); (N.H.C.R.)
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Loconsole D, Giordano M, Centrone F, Accogli M, Casulli D, De Robertis AL, Morea A, Quarto M, Parisi A, Scavia G, Chironna M. Epidemiology of Shiga Toxin-Producing Escherichia coli Infections in Southern Italy after Implementation of Symptom-Based Surveillance of Bloody Diarrhea in the Pediatric Population. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:E5137. [PMID: 32708640 PMCID: PMC7400587 DOI: 10.3390/ijerph17145137] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 07/08/2020] [Accepted: 07/14/2020] [Indexed: 12/30/2022]
Abstract
Shiga toxin-producing Escherichia coli (STEC) infections result in a significant public health impact because of the severity of the disease that, in young children especially, can lead to hemolytic-uremic syndrome (HUS). A rise in the number of HUS cases was observed in the Apulia region of Italy from 2013 to 2017, and so, in 2018, a symptom-based surveillance system for children with bloody diarrhea (BD) was initiated in order to detect and manage STEC infections. The objective of the study was to describe the epidemiology of STEC infections in children from June 2018 to August 2019. Children <15 years old with BD were hospitalized and tested for STEC. Real-time PCR for virulence genes (stx1, stx2, eae) and serogroup identification tests were performed on stool samples/rectal swabs of cases. STEC infection was detected in 87 (10.6%) BD cases. The median age of STEC cases was 2.7 years, and 60 (68.9%) were <4. Of these 87 cases, 12 (13.8%) came from households with diarrhea. The reporting rate was 14.2/100,000, with the highest incidence in cases from the province of Bari (24.2/100,000). Serogroups O26 and O111 were both detected in 22/87 (25.3%) cases. Co-infections occurred in 12.6% of cases (11/87). Twenty-nine STEC were positive for stx1, stx2, and eae. Five cases (5.7%) caused by O26 (n = 2), O111 (n = 2), and O45 (n = 1) developed into HUS. A risk-oriented approach based on the testing of children with BD during the summer may represent a potentially beneficial option to improve the sensitivity of STEC surveillance, not only in Italy but also in the context of Europe as a whole.
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Affiliation(s)
- Daniela Loconsole
- Department of Biomedical Sciences and Human Oncology-Hygiene Section, University of Bari, Piazza G. Cesare 11, 70124 Bari, Italy; (D.L.); (F.C.); (M.A.); (D.C.); (A.L.D.R.); (A.M.); (M.Q.)
| | - Mario Giordano
- Pediatric Nephrology and Dialysis Unit, Pediatric Hospital “Giovanni XXIII”, Via Giovanni Amendola, 207, 70126 Bari, Italy;
| | - Francesca Centrone
- Department of Biomedical Sciences and Human Oncology-Hygiene Section, University of Bari, Piazza G. Cesare 11, 70124 Bari, Italy; (D.L.); (F.C.); (M.A.); (D.C.); (A.L.D.R.); (A.M.); (M.Q.)
| | - Marisa Accogli
- Department of Biomedical Sciences and Human Oncology-Hygiene Section, University of Bari, Piazza G. Cesare 11, 70124 Bari, Italy; (D.L.); (F.C.); (M.A.); (D.C.); (A.L.D.R.); (A.M.); (M.Q.)
| | - Daniele Casulli
- Department of Biomedical Sciences and Human Oncology-Hygiene Section, University of Bari, Piazza G. Cesare 11, 70124 Bari, Italy; (D.L.); (F.C.); (M.A.); (D.C.); (A.L.D.R.); (A.M.); (M.Q.)
| | - Anna Lisa De Robertis
- Department of Biomedical Sciences and Human Oncology-Hygiene Section, University of Bari, Piazza G. Cesare 11, 70124 Bari, Italy; (D.L.); (F.C.); (M.A.); (D.C.); (A.L.D.R.); (A.M.); (M.Q.)
| | - Anna Morea
- Department of Biomedical Sciences and Human Oncology-Hygiene Section, University of Bari, Piazza G. Cesare 11, 70124 Bari, Italy; (D.L.); (F.C.); (M.A.); (D.C.); (A.L.D.R.); (A.M.); (M.Q.)
| | - Michele Quarto
- Department of Biomedical Sciences and Human Oncology-Hygiene Section, University of Bari, Piazza G. Cesare 11, 70124 Bari, Italy; (D.L.); (F.C.); (M.A.); (D.C.); (A.L.D.R.); (A.M.); (M.Q.)
| | - Antonio Parisi
- Istituto Zooprofilattico Sperimentale della Puglia e della Basilicata, Via Manfredonia, 20, 71121 Foggia, Italy;
| | - Gaia Scavia
- Food Safety, Nutrition and Veterinary Public Health Department, Istituto Superiore di Sanità, Viale Regina Elena, 299, 00161 Rome, Italy;
| | - Maria Chironna
- Department of Biomedical Sciences and Human Oncology-Hygiene Section, University of Bari, Piazza G. Cesare 11, 70124 Bari, Italy; (D.L.); (F.C.); (M.A.); (D.C.); (A.L.D.R.); (A.M.); (M.Q.)
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Collis RM, Biggs PJ, Midwinter AC, Browne AS, Wilkinson DA, Irshad H, French NP, Brightwell G, Cookson AL. Genomic epidemiology and carbon metabolism of Escherichia coli serogroup O145 reflect contrasting phylogenies. PLoS One 2020; 15:e0235066. [PMID: 32584859 PMCID: PMC7316241 DOI: 10.1371/journal.pone.0235066] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 06/08/2020] [Indexed: 11/18/2022] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) are a leading cause of foodborne outbreaks of human disease, but they reside harmlessly as an asymptomatic commensal in the ruminant gut. STEC serogroup O145 are difficult to isolate as routine diagnostic methods are unable to distinguish non-O157 serogroups due to their heterogeneous metabolic characteristics, resulting in under-reporting which is likely to conceal their true prevalence. In light of these deficiencies, the purpose of this study was a twofold approach to investigate enhanced STEC O145 diagnostic culture-based methods: firstly, to use a genomic epidemiology approach to understand the genetic diversity and population structure of serogroup O145 at both a local (New Zealand) (n = 47) and global scale (n = 75) and, secondly, to identify metabolic characteristics that will help the development of a differential media for this serogroup. Analysis of a subset of E. coli serogroup O145 strains demonstrated considerable diversity in carbon utilisation, which varied in association with eae subtype and sequence type. Several carbon substrates, such as D-serine and D-malic acid, were utilised by the majority of serogroup O145 strains, which, when coupled with current molecular and culture-based methods, could aid in the identification of presumptive E. coli serogroup O145 isolates. These carbon substrates warrant subsequent testing with additional serogroup O145 strains and non-O145 strains. Serogroup O145 strains displayed extensive genetic heterogeneity that was correlated with sequence type and eae subtype, suggesting these genetic markers are good indicators for distinct E. coli phylogenetic lineages. Pangenome analysis identified a core of 3,036 genes and an open pangenome of >14,000 genes, which is consistent with the identification of distinct phylogenetic lineages. Overall, this study highlighted the phenotypic and genotypic heterogeneity within E. coli serogroup O145, suggesting that the development of a differential media targeting this serogroup will be challenging.
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Affiliation(s)
- Rose M. Collis
- AgResearch Ltd, Hopkirk Research Institute, Massey University, Palmerston North, New Zealand
- Molecular Epidemiology and Veterinary Public Health Laboratory (EpiLab), Infectious Disease Research Centre, School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - Patrick J. Biggs
- Molecular Epidemiology and Veterinary Public Health Laboratory (EpiLab), Infectious Disease Research Centre, School of Veterinary Science, Massey University, Palmerston North, New Zealand
- School of Fundamental Sciences, Massey University, Palmerston North, New Zealand
- New Zealand Food Safety Science and Research Centre, Massey University, Palmerston North, New Zealand
| | - Anne C. Midwinter
- Molecular Epidemiology and Veterinary Public Health Laboratory (EpiLab), Infectious Disease Research Centre, School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - A. Springer Browne
- Molecular Epidemiology and Veterinary Public Health Laboratory (EpiLab), Infectious Disease Research Centre, School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - David A. Wilkinson
- Molecular Epidemiology and Veterinary Public Health Laboratory (EpiLab), Infectious Disease Research Centre, School of Veterinary Science, Massey University, Palmerston North, New Zealand
- New Zealand Food Safety Science and Research Centre, Massey University, Palmerston North, New Zealand
| | - Hamid Irshad
- Animal Health Programme, National Agricultural Research Centre, Islamabad, Pakistan
| | - Nigel P. French
- Molecular Epidemiology and Veterinary Public Health Laboratory (EpiLab), Infectious Disease Research Centre, School of Veterinary Science, Massey University, Palmerston North, New Zealand
- New Zealand Food Safety Science and Research Centre, Massey University, Palmerston North, New Zealand
| | - Gale Brightwell
- AgResearch Ltd, Hopkirk Research Institute, Massey University, Palmerston North, New Zealand
- New Zealand Food Safety Science and Research Centre, Massey University, Palmerston North, New Zealand
| | - Adrian L. Cookson
- AgResearch Ltd, Hopkirk Research Institute, Massey University, Palmerston North, New Zealand
- Molecular Epidemiology and Veterinary Public Health Laboratory (EpiLab), Infectious Disease Research Centre, School of Veterinary Science, Massey University, Palmerston North, New Zealand
- * E-mail:
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12
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Genetic diversity of the intimin gene (eae) in non-O157 Shiga toxin-producing Escherichia coli strains in China. Sci Rep 2020; 10:3275. [PMID: 32094410 PMCID: PMC7040016 DOI: 10.1038/s41598-020-60225-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 02/05/2020] [Indexed: 12/24/2022] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) is an important foodborne pathogen. The increasing incidence of non-O157 STEC has posed a great risk to public health. Besides the Shiga toxin (Stx), the adherence factor, intimin, coded by eae gene plays a critical role in STEC pathogenesis. In this study, we investigated the prevalence and polymorphisms of eae gene in non-O157 STEC strains isolated from different sources in China. Among 735 non-O157 STEC strains, eae was present in 70 (9.5%) strains. Eighteen different eae genotypes were identified in 62 eae-positive STEC strains with the nucleotide identities ranging from 86.01% to 99.97%. Among which, seven genotypes were newly identified in this study. The eighteen eae genotypes can be categorized into five eae subtypes, namely β1, γ1, ε1, ζ3 and θ. Associations between eae subtypes/genotypes and serotypes as well as origins of strains were observed in this study. Strains belonging to serotypes O26:H11, O103:H2, O111:H8 are associated with particular eae subtypes, i.e., β1, ε1, θ, respectively. Most strains from diarrheal patients (7/9, 77.8%) carried eae-β1 subtype, while most isolates from cattle (23/26, 88.5%) carried eae-ζ3 subtype. This study demonstrated a genetic diversity of eae gene in non-O157 STEC strains from different sources in China.
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Koutsoumanis K, Allende A, Alvarez‐Ordóñez A, Bover‐Cid S, Chemaly M, Davies R, De Cesare A, Herman L, Hilbert F, Lindqvist R, Nauta M, Peixe L, Ru G, Simmons M, Skandamis P, Suffredini E, Jenkins C, Monteiro Pires S, Morabito S, Niskanen T, Scheutz F, da Silva Felício MT, Messens W, Bolton D. Pathogenicity assessment of Shiga toxin‐producing Escherichia coli (STEC) and the public health risk posed by contamination of food with STEC. EFSA J 2020. [DOI: 10.2903/j.efsa.2020.5967] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
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Hemolytic uremic syndrome caused by Shiga toxin-producing Escherichia coli in children: incidence, risk factors, and clinical outcome. Pediatr Nephrol 2020; 35:1749-1759. [PMID: 32323005 PMCID: PMC7385025 DOI: 10.1007/s00467-020-04560-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 03/22/2020] [Accepted: 03/30/2020] [Indexed: 12/27/2022]
Abstract
BACKGROUND Hemolytic uremic syndrome (HUS) is a multisystemic disease. In a nationwide study, we characterized the incidence, clinical course, and prognosis of HUS caused by Shiga toxin (Stx)-producing Escherichia coli (STEC) strains with emphasis on risk factors, disease severity, and long-term outcome. METHODS The data on pediatric HUS patients from 2000 to 2016 were collected from the medical records. STEC isolates from fecal cultures of HUS and non-HUS patients were collected from the same time period and characterized by whole genome sequencing analysis. RESULTS Fifty-eight out of 262 culture-positive cases developed verified (n = 58, 22%) STEC-HUS. Another 29 cases had probable STEC-HUS, the annual incidence of STEC-HUS being 0.5 per 100,000 children. Eleven different serogroups were detected, O157 being the most common (n = 37, 66%). Age under 3 years (OR 2.4), stx2 (OR 9.7), and stx2a (OR 16.6) were found to be risk factors for HUS. Fifty-five patients (63%) needed dialysis. Twenty-nine patients (33%) developed major neurological symptoms. Complete renal recovery was observed in 57 patients after a median 4.0 years of follow-up. Age under 3 years, leukocyte count over 20 × 109/L, and need for dialysis were predictive factors for poor renal outcome. CONCLUSIONS Age under 3 years, stx2, and stx2a were risk factors for HUS in STEC-positive children. However, serogroup or stx types did not predict the renal outcome or major CNS symptoms.
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The importance of integrating genetic strain information for managing cases of Shiga toxin-producing E. coli infection. Epidemiol Infect 2019; 147:e264. [PMID: 31496452 PMCID: PMC6805796 DOI: 10.1017/s0950268819001602] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
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Carroll KJ, Harvey-Vince L, Jenkins C, Mohan K, Balasegaram S. The epidemiology of Shiga toxin-producing Escherichia coli infections in the South East of England: November 2013-March 2017 and significance for clinical and public health. J Med Microbiol 2019; 68:930-939. [PMID: 30994441 DOI: 10.1099/jmm.0.000970] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
PURPOSE This study describes the epidemiology of Shiga toxin-producing Escherichia coli (STEC) infections in a population in the South East of England. METHODS From 1 November 2013 to 31 March 2017 participating diagnostic laboratories reported Shiga toxin gene (stx) positive real-time PCR results to local public health teams. Stx positive faecal samples/isolates were referred to the Gastrointestinal Bacteria Reference Unit (GBRU) for confirmation by culture and typing by whole genome sequencing (WGS). Key clinical information was collected by public health teams.Results/Key findings. Altogether, 548 faecal specimens (420 were non-travel associated) were stx positive locally, 535 were submitted to the GBRU. STEC were isolated from 42 %, confirmed by stx PCR in 21 % and 37 % were PCR negative. The most common non-travel associated STEC serogroups were O157, O26, O146 and O91. The annualized incidence of confirmed STEC infections (PCR or culture) was 5.8 per 100 000. The ratio of O157 to non-O157 STEC serogroups was 1:7. The annualized incidence of non-O157 haemolytic uraemic syndrome-associated Escherichia coli (HUSEC) strains was 0.4 per 100 000. Bloody diarrhoea was reported by 58 % of cases infected with E. coli O157, 33 % of cases infected with non-O157 HUSEC strains and 12 % of other lower risk non-O157 strains. Overall, 76 % of non-O157 HUSEC isolates possessed the eae virulence gene. CONCLUSIONS HUSEC including serogroup O157 were uncommon and more likely to cause bloody diarrhoea than other STEC. The routine use of stx PCR testing can influence clinical management. Understanding the local epidemiology facilitates a proportionate public health response to STEC, based on clinical and microbiological characteristics including stx subtype(s).
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Affiliation(s)
- Kevin J Carroll
- 1 PHE South East, Surrey and Sussex HPT, Parkside, Chart Way, Horsham RH12 1XA, UK
| | - Lisa Harvey-Vince
- 1 PHE South East, Surrey and Sussex HPT, Parkside, Chart Way, Horsham RH12 1XA, UK
| | - Claire Jenkins
- 2 Gastrointestinal Bacteria Reference Unit, Public Health England, 61 Colindale Avenue, London NW9 5HT, UK
| | - Keerthi Mohan
- 3 PHE South East, Thames Valley HPT, Chilton, Oxon, OX11 0RQ, UK
| | - Sooria Balasegaram
- 4 Field Services, National Infection Service, Public Health England, London, UK
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