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Gong L, Tang N, Chen D, Sun K, Lan R, Zhang W, Zhou H, Yuan M, Chen X, Zhao X, Che J, Bai X, Zhang Y, Xu H, Walsh TR, Lu J, Xu J, Li J, Feng J. A Nosocomial Respiratory Infection Outbreak of Carbapenem-Resistant Escherichia coli ST131 With Multiple Transmissible bla KPC-2 Carrying Plasmids. Front Microbiol 2020; 11:2068. [PMID: 33042037 PMCID: PMC7516988 DOI: 10.3389/fmicb.2020.02068] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 08/06/2020] [Indexed: 11/13/2022] Open
Abstract
Escherichia coli sequence type 131 (ST131) is well known for its multidrug resistance profile. Carbapenems have been considered the treatment of choice for E. coli ST131 infections, and resistance to carbapenems is emerging due to the acquisition of carbapenemase-encoding genes. In this study, 45 carbapenem-resistant E. coli strains were collected in a hospital. The resistance mechanisms, plasmid profiles, and genetic relatedness of these strains were determined. Phylogenetic relationships between these strains were assessed by molecular profiling and aligned with patient clinical details. The genetic context of bla KPC-2 was analyzed to trace the potential dissemination of bla KPC-2. The 45 carbapenem-resistant E. coli ST131 strains were closely related. Initially prevalent only in a single ward, ST131 subsequently spread to other ward, resulting in a respiratory infection outbreak of carbapenem-resistant E. coli ST131. Eight of the 30 patients died within 28 days of the first isolation of E. coli ST131. The bla KPC-2-positive plasmid profiles suggest that the carbapenem resistance was due to the acquisition by E. coli ST131 of transmissible plasmids pE0272_KPC and pE0171_KPC carrying bla KPC-2. Additionally, diverse multidrug resistance elements were transferred and rearranged between these plasmids mediated by IS26. Our research indicates that clinical attention should be paid to the importance of E. coli ST131 in respiratory infections and the spread of bla KPC -carrying E. coli ST131.
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Affiliation(s)
- Lin Gong
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, China CDC, Beijing, China
- Wuhan Centers for Disease Prevention and Control, Wuhan, China
| | - Na Tang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- College of Life Science, University of Chinese Academy of Sciences, Beijing, China
| | - Dongke Chen
- Department of Laboratory Medicine, Beijing Hospital, National Center of Gerontology, Beijing, China
| | - Kaiwen Sun
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Ruiting Lan
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Wen Zhang
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, China CDC, Beijing, China
| | - Haijian Zhou
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, China CDC, Beijing, China
| | - Min Yuan
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, China CDC, Beijing, China
| | - Xia Chen
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, China CDC, Beijing, China
| | - Xiaofei Zhao
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, China CDC, Beijing, China
| | - Jie Che
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, China CDC, Beijing, China
| | - Xuemei Bai
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, China CDC, Beijing, China
| | - Yunfei Zhang
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, China CDC, Beijing, China
| | - Hongtao Xu
- Department of Laboratory Medicine, Beijing Hospital, National Center of Gerontology, Beijing, China
| | - Timothy R. Walsh
- Department of Medical, Microbiology, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Jinxing Lu
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, China CDC, Beijing, China
| | - Jianguo Xu
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, China CDC, Beijing, China
| | - Juan Li
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, China CDC, Beijing, China
| | - Jie Feng
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
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Variability in Characterizing Escherichia coli from Cattle Feces: A Cautionary Tale. Microorganisms 2018; 6:microorganisms6030074. [PMID: 30037096 PMCID: PMC6165469 DOI: 10.3390/microorganisms6030074] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 07/17/2018] [Accepted: 07/20/2018] [Indexed: 11/17/2022] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) are diverse bacteria, with seven serogroups (O26, O45, O103, O111, O121, O145, O157; "Top 7") of interest due to their predominance in human disease. Confirmation of STEC relies on a combination of culturing, immunological and molecular assays, but no single gold standard for identification exists. In this study, we compared analysis of STEC between three independent laboratories (LAB) using different methodologies. In LAB A, colonies of Top 7 were picked after serogroup-specific immunomagnetic separation of feces from western-Canadian slaughter cattle. A fraction of each colony was tested by PCR (stx1, stx2, eae, O group), and Top 7 isolates were saved as glycerol stocks (n = 689). In LAB B, a subsample of isolates (n = 171) were evaluated for stx1 and stx2 using different primer sets. For this, approximately half of the PCR were performed using original DNA template provided by LAB A and half using DNA extracted from sub-cultured isolates. All Top 7 isolates were sub-cultured by LAB A and shipped to LAB C for traditional serotyping (TS) to determine O and H groups, with PCR-confirmation of virulence genes using a third set of primers. By TS, 76% of O groups (525/689) matched PCR-determined O groups. Lowest proportions (p < 0.05) of O group matches between PCR and TS (62.6% and 69.8%) occurred for O26 and O45 serogroups, respectively. PCR-detection of stx differed most between LAB A and LAB C. Excluding isolates where O groups by PCR and TS did not match, detection of stx1 was most consistent (p < 0.01) for O111 and O157:H7/NM. In contrast, for O45 and O103, stx1 was detected in >65% of isolates by LAB A and <5% by LAB C. Stx2 was only detected by LAB C in isolates of serogroups O121, O145, and O157:H7/NM. LAB B also detected stx2 in O26 and O157:H12/H29, while LAB A detected stx2 in all serogroups. Excluding O111 and O157:H7/NM, marked changes in stx detection were observed between initial isolation and sub-cultures of the same isolate. While multiple explanations exist for discordant O-typing between PCR and TS and for differences in stx detection across labs, these data suggest that assays for STEC classification may require re-evaluation and/or standardization.
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Hallewell J, Alexander T, Reuter T, Stanford K. Limitations of Immunomagnetic Separation for Detection of the Top Seven Serogroups of Shiga Toxin-Producing Escherichia coli. J Food Prot 2017; 80:598-603. [PMID: 28334549 DOI: 10.4315/0362-028x.jfp-16-427] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Shiga toxin-producing Escherichia coli (STEC) strains are foodborne pathogens that negatively impact human health and compromise food safety. Serogroup O157 is the most frequently isolated and studied STEC serogroup, but six others (O26, O45, O103, O111, O121, and O145) have also been identified as significant sources of human disease and collectively have been referred to as the "top six" pathogenic serogroups. Because detection methods for non-O157 serogroups are not yet refined, the objective of this study was to compare the effectiveness of immunomagnetic separation (IMS) for recovery of serogroup O157 isolates with that for each of the top six E. coli serogroups in pure and mixed cultures of STEC at 103 to 107 CFU/mL. After serogroup-specific IMS, DNA was extracted from cultured isolates to analyze the specificity of each IMS assay using conventional and quantitative PCR. In pure cultures, DNA copy number obtained after IMS was lower for O111 and O157 (P < 0.01) than for other serogroups. Based on quantitative PCR (qPCR) analyses, specificity was reduced for all IMS assays when STEC isolates were mixed at 7 log CFU/mL, although the O157 IMS assays recovered only O157 over a wider range of concentrations than did assays for non-O157 serogroups. At the lowest dilution tested, conventional PCR was specific for all serogroups except O121 and O145. For these two serogroups, no dilution tested recovered only O121 or O145 when evaluated with conventional PCR. Refinements to IMS assays, development of selective media, and determination of optimal enrichment times to reduce background microflora or competition among serogroups would be especially beneficial for recovery of O111, O121, and O145 serogroups to improve STEC detection and isolation.
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Affiliation(s)
- J Hallewell
- Agriculture and Agri-food Canada, Lethbridge Research Center, Lethbridge, Alberta, Canada T1J 4P4
| | - T Alexander
- Agriculture and Agri-food Canada, Lethbridge Research Center, Lethbridge, Alberta, Canada T1J 4P4
| | - T Reuter
- Alberta Agriculture and Forestry, Agriculture Centre, Lethbridge, Alberta, Canada T1J 4V6 (ORCID: http://orcid.org/0000-0001-8784-0042 [K.S.])
| | - K Stanford
- Alberta Agriculture and Forestry, Agriculture Centre, Lethbridge, Alberta, Canada T1J 4V6 (ORCID: http://orcid.org/0000-0001-8784-0042 [K.S.])
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Hallewell J, Reuter T, Stanford K, Topp E, Alexander TW. Monitoring Seven Potentially Pathogenic Escherichia coli Serogroups in a Closed Herd of Beef Cattle from Weaning to Finishing Phases. Foodborne Pathog Dis 2016; 13:661-667. [PMID: 27779903 DOI: 10.1089/fpd.2016.2164] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The goal of this study was to monitor Shiga toxin-producing Escherichia coli (STEC) serogroups and virulence genes in cattle (n = 30) originating from a closed herd. Fecal samples were collected (1) at weaning, (2) upon arrival to a feedlot, (3) after 30 days on feed (DOF), and (4) after 135 DOF. DNA was extracted from feces for detection of virulence and serogroup genes by polymerase chain reaction (PCR) and immunomagnetic separation and pulsed-field gel electrophoresis (PFGE) were performed to collect and subtype STEC isolates. The prevalence of each serogroup measured by PCR from weaning to 135 DOF was 23.3-80.0% for O26, 33.3-46.7% for O45, 70.0-73.3% for O103, 36.7-86.7% for O111, 56.7-6.7% for O121, 26.7-66.7% for O145, and 66.7-90.0% for O157. Total fecal samples positive for virulence genes were 87.5% for ehxA, 85.8% for stx1, 60.0% for stx2, 52.5% for eae, and 44.2% for the autoagglutinating adhesion gene, saa. The prevalence of each serogroup and virulence gene tended to increase by 135 DOF, with the exception of O121, stx2, and saa. The frequency of detection of some virulence genes was largely affected over time, most notably with saa and stx2 decreasing, and eae increasing when cattle were transitioned to concentrate-based diets. PFGE analysis of O157 and O103 fecal isolates revealed dominant pulsotypes, but the presence of identical O103 isolates, which differed in virulence profiles. Overall, this study showed that fecal shedding of E. coli serogroups and virulence-associated genes are highly variable over time as cattle move from ranch to feedlot. To mitigate STEC, it is important to understand the factors affecting both prevalence of individual serogroups and the presence of virulence factors.
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Affiliation(s)
- Jennyka Hallewell
- 1 Agriculture and Agri-Food Canada, Lethbridge Research Centre , Lethbridge, Canada
| | - Tim Reuter
- 2 Alberta Agriculture and Forestry, Agriculture Centre , Lethbridge, Canada
| | - Kim Stanford
- 2 Alberta Agriculture and Forestry, Agriculture Centre , Lethbridge, Canada
| | - Ed Topp
- 3 Agriculture and Agri-Food Canada, Southern Crop Protection and Food Research Centre , London, Canada
| | - Trevor W Alexander
- 1 Agriculture and Agri-Food Canada, Lethbridge Research Centre , Lethbridge, Canada
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Vázquez-Marrufo G, Rosales-Castillo JA, Robinson-Fuentes VA, Tafolla-Muñoz I, Carreras-Villaseñor N, Vázquez-Garcidueñas MS. Multi-Typing of Enterobacteria Harboring LT and ST Enterotoxin Genes Isolated from Mexican Children. Jpn J Infect Dis 2016; 70:50-60. [PMID: 27169941 DOI: 10.7883/yoken.jjid.2015.454] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Enterotoxigenic Escherichia coli is the most common cause of diarrhea in children younger than 5 years in the developing world. We used 16S rRNA gene sequencing, the Biolog® system, and an Amplified Ribosomal DNA Restriction Analysis (ARDRA) to identify 69 enterobacteria isolated from the feces of healthy children up to 12 years old and 54 enterobacteria isolated from stool samples obtained from children up to 5 years old with diarrhea from Morelia, Michoacán, Mexico. In the diarrheic group, 18 isolates belonged to the enterotoxigenic pathotype, 1 isolate had both LT (heat labile toxin) gene and ST (heat stable toxin) gene, and 17 had the ST gene. The identity of most of the strains harboring the ST gene was E. coli, and 3 of the strains were identified as Morganella morganii. The ST toxin gene of one of the strains identified as M. morganii showed 100% identity with an ST toxin gene of E. coli. The ARDRA was a very useful tool to differentiate between E. coli and M. morganii. The phenotypic and genetic analyses of the isolates using the Biolog® system and Random Amplified Polymorphic DNA, respectively, showed physiological variation among the studied strains and genetic differences between subgroups.
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Affiliation(s)
- Gerardo Vázquez-Marrufo
- Multidisciplinary Center for Studies in Biotechnology, Faculty of Veterinary Medicine, Michoacán University of San Nicolás of Hidalgo
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Peresi JTM, Almeida IAZCD, Vaz TMI, Hernandes RT, Teixeira ISDC, Silva SIDLE, Graciano RAS, Pinheiro SR, dos Santos LF. Search for diarrheagenic Escherichia coli in raw kibbe samples reveals the presence of Shiga toxin-producing strains. Food Control 2016. [DOI: 10.1016/j.foodcont.2015.11.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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7
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Genotype Cluster Analysis in Pathogenic Escherichia coli Isolates Producing Different CDT Types. J Pathog 2016; 2016:9237127. [PMID: 27042356 PMCID: PMC4794564 DOI: 10.1155/2016/9237127] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 01/31/2016] [Accepted: 02/04/2016] [Indexed: 01/19/2023] Open
Abstract
Diarrheagenic and uropathogenic E. coli types are mainly characterized by the expression of distinctive bacterial virulent factors. stx1, stx2 (Shiga toxins), and cdt (cytolethal distending toxin) genes have been acquired by horizontal gene transfer. Some virulent genes such as espP (serine protease), etpD (part of secretion pathway), and katP (catalase-peroxidase), or sfpA gene (Sfp fimbriae), are on plasmids and the others like fliC (flagellin) and the fimH gene (fimbriae type-I) are located on chromosome. Genomic pathogenicity islands (PAIs) carry some virulent genes such as hly gene. To determine the existence of virulence genes in cdt clinical isolates, genes including stx1, stx2, cdt, hly, espP, katP, sfpA, etpD, fliC, and fimH were assessed by Polymerase Chain Reaction (PCR). The most prevalent isolates for etpD and katP genes were 85.7% in cdtII. katP gene was also observed 83.3% in cdtI. However, in 42.85% of cdtIII isolates, espP gene was the most detected. Moreover, hly gene was also the most prominent gene in cdtIII (71.42%). sfpA gene was observed in 66.6% of cdtV. stx1 gene was detected in 100% of cdtII, cdtIV, and cdtV types. Presence and pattern of virulence genes were considered among cdt positive isotypes and used for their clustering and profiling.
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Söderlund R, Hurel J, Jinnerot T, Sekse C, Aspán A, Eriksson E, Bongcam-Rudloff E. Genomic comparison of Escherichia coli serotype O103:H2 isolates with and without verotoxin genes: implications for risk assessment of strains commonly found in ruminant reservoirs. Infect Ecol Epidemiol 2016; 6:30246. [PMID: 26895282 PMCID: PMC4759829 DOI: 10.3402/iee.v6.30246] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Revised: 01/18/2016] [Accepted: 01/19/2016] [Indexed: 12/03/2022] Open
Abstract
Introduction Escherichia coli O103:H2 occurs as verotoxigenic E. coli (VTEC) carrying only vtx1 or vtx2 or both variants, but also as vtx-negative atypical enteropathogenic E. coli (aEPEC). The majority of E. coli O103:H2 identified from cases of human disease are caused by the VTEC form. If aEPEC strains frequently acquire verotoxin genes and become VTEC, they must be considered a significant public health concern. In this study, we have characterized and compared aEPEC and VTEC isolates of E. coli O103:H2 from Swedish cattle. Methods Fourteen isolates of E. coli O103:H2 with and without verotoxin genes were collected from samples of cattle feces taken during a nationwide cattle prevalence study 2011–2012. Isolates were sequenced with a 2×100 bp setup on a HiSeq2500 instrument producing >100× coverage per isolate. Single-nucleotide polymorphism (SNP) typing was performed using the genome analysis tool kit (GATK). Virulence genes and other regions of interest were detected. Susceptibility to transduction by two verotoxin-encoding phages was investigated for one representative aEPEC O103:H2 isolate. Results and Discussion This study shows that aEPEC O103:H2 is more commonly found (64%) than VTEC O103:H2 (36%) in the Swedish cattle reservoir. The only verotoxin gene variant identified was vtx1a. Phylogenetic comparison by SNP analysis indicates that while certain subgroups of aEPEC and VTEC are closely related and have otherwise near identical virulence gene repertoires, they belong to separate lineages. This indicates that the uptake or loss of verotoxin genes is a rare event in the natural cattle environment of these bacteria. However, a representative of a VTEC-like aEPEC O103:H2 subgroup could be stably lysogenized by a vtx-encoding phage in vitro.
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Affiliation(s)
- Robert Söderlund
- SLU Global Bioinformatics Centre, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden.,Department of Microbiology, National Veterinary Institute (SVA), Uppsala, Sweden;
| | - Julie Hurel
- SLU Global Bioinformatics Centre, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden
| | - Tomas Jinnerot
- Department of Microbiology, National Veterinary Institute (SVA), Uppsala, Sweden
| | - Camilla Sekse
- Department of Laboratory Services, Norwegian Veterinary Institute (NVI), Oslo, Norway
| | - Anna Aspán
- Department of Microbiology, National Veterinary Institute (SVA), Uppsala, Sweden
| | - Erik Eriksson
- Department of Microbiology, National Veterinary Institute (SVA), Uppsala, Sweden
| | - Erik Bongcam-Rudloff
- SLU Global Bioinformatics Centre, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden
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Abstract
Shiga toxin-producing Escherichia coli (STEC) strains are commonly found in the intestine of ruminant species of wild and domestic animals. Excretion of STEC with animal feces results in a broad contamination of food and the environment. Humans get infected with STEC through ingestion of contaminated food, by contact with the environment, and from STEC-excreting animals and humans. STEC strains can behave as human pathogens, and some of them, called enterohemorrhagic E. coli (EHEC), may cause hemorrhagic colitis (HC) and hemolytic-uremic syndrome (HUS). Because of the diversity of STEC types, detection strategies for STEC and EHEC are based on the identification of Shiga toxins or the underlying genes. Cultural enrichment of STEC from test samples is needed for identification, and different protocols were developed for this purpose. Multiplex real-time PCR protocols (ISO/CEN TS13136 and USDA/FSIS MLG5B.01) have been developed to specifically identify EHEC by targeting the LEE (locus of enterocyte effacement)-encoded eae gene and genes for EHEC-associated O groups. The employment of more genetic markers (nle and CRISPR) is a future challenge for better identification of EHEC from any kinds of samples. The isolation of STEC or EHEC from a sample is required for confirmation, and different cultivation protocols and media for this purpose have been developed. Most STEC strains present in food, animals, and the environment are eae negative, but some of these strains can cause HC and HUS in humans as well. Phenotypic assays and molecular tools for typing EHEC and STEC strains are used to detect and characterize human pathogenic strains among members of the STEC group.
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Desin TS, Townsend HG, Potter AA. Antibodies Directed against Shiga-Toxin Producing Escherichia coli Serotype O103 Type III Secreted Proteins Block Adherence of Heterologous STEC Serotypes to HEp-2 Cells. PLoS One 2015; 10:e0139803. [PMID: 26451946 PMCID: PMC4599963 DOI: 10.1371/journal.pone.0139803] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 09/17/2015] [Indexed: 11/25/2022] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) serotype O103 is a zoonotic pathogen that is capable of causing hemorrhagic colitis and hemolytic uremic syndrome (HUS) in humans. The main animal reservoir for STEC is ruminants and hence reducing the levels of this pathogen in cattle could ultimately lower the risk of STEC infection in humans. During the process of infection, STECO103 uses a Type III Secretion System (T3SS) to secrete effector proteins (T3SPs) that result in the formation of attaching and effacing (A/E) lesions. Vaccination of cattle with STEC serotype O157 T3SPs has previously been shown to be effective in reducing shedding of STECO157 in a serotype-specific manner. In this study, we tested the ability of rabbit polyclonal sera against individual STECO103 T3SPs to block adherence of the organism to HEp-2 cells. Our results demonstrate that pooled sera against EspA, EspB, EspF, NleA and Tir significantly lowered the adherence of STECO103 relative to pre-immune sera. Likewise, pooled anti-STECO103 sera were also able to block adherence by STECO157. Vaccination of mice with STECO103 recombinant proteins induced strong IgG antibody responses against EspA, EspB, NleA and Tir but not against EspF. However, the vaccine did not affect fecal shedding of STECO103 compared to the PBS vaccinated group over the duration of the experiment. Cross reactivity studies using sera against STECO103 recombinant proteins revealed a high degree of cross reactivity with STECO26 and STECO111 proteins implying that sera against STECO103 proteins could potentially provide neutralization of attachment to epithelial cells by heterologous STEC serotypes.
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Affiliation(s)
- Taseen S. Desin
- Vaccine & Infectious Disease Organization–International Vaccine Center, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
- * E-mail:
| | - Hugh G. Townsend
- Vaccine & Infectious Disease Organization–International Vaccine Center, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Andrew A. Potter
- Vaccine & Infectious Disease Organization–International Vaccine Center, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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11
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Cergole-Novella MC, Pignatari ACC, Guth BEC. Adhesion, biofilm and genotypic characteristics of antimicrobial resistant Escherichia coli isolates. Braz J Microbiol 2015. [PMID: 26221104 PMCID: PMC4512061 DOI: 10.1590/s1517-838246120140077] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Aggregative adherence to human epithelial cells, most to renal proximal tubular (HK-2) cells, and biofilm formation was identified among antimicrobial resistant Escherichia coli strains mainly isolated from bacteremia. The importance of these virulence properties contributing to host colonization and infection associated with multiresistant E. coli should not be neglected.
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Affiliation(s)
- Maria C Cergole-Novella
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Antonio C C Pignatari
- Divisão de Doenças Infecciosas, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Beatriz E C Guth
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil
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Li J, Lan R, Xiong Y, Ye C, Yuan M, Liu X, Chen X, Yu D, Liu B, Lin W, Bai X, Wang Y, Sun Q, Wang Y, Zhao H, Meng Q, Chen Q, Zhao A, Xu J. Sequential isolation in a patient of Raoultella planticola and Escherichia coli bearing a novel ISCR1 element carrying blaNDM-1. PLoS One 2014; 9:e89893. [PMID: 24594606 PMCID: PMC3940617 DOI: 10.1371/journal.pone.0089893] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Accepted: 01/23/2014] [Indexed: 11/30/2022] Open
Abstract
Background The gene for New Delhi metallo-β-lactamase 1 (NDM-1) has been reported to be transmitted via plasmids which are easily transferable and capable of wide distribution. We report the isolation of two NDM-1 producing strains and possible in vivo transfer of blaNDM-1 in a patient. Methods Clinical samples were collected for bacterial culture and antibiotic susceptibility testing from a patient during a 34-day hospitalization. The presence of blaNDM-1 was detected by PCR and sequencing. Plasmids of interest were sequenced. Medical records were reviewed for evidence of association between the administration of antibiotics and the acquisition of the NDM-1 resistance. Results A NDM-1 positive Raoultella planticola was isolated from blood on the ninth day of hospitalization without administration of any carbapenem antibiotics and a NDM-1 positive Escherichia coli was isolated from feces on the 29th day of hospitalization and eight days after imipenem administration. The blaNDM-1 was carried by a 280 kb plasmid pRpNDM1-1 in R. planticola and a 58 kb plasmid pEcNDM1-4 in E. coli. The two plasmids shared a 4812 bp NDM-1-ISCR1 element which was found to be excisable from the plasmid as a free form and transferrable in vitro to a NDM-1 negative plasmid from E. coli. Conclusion blaNDM-1 was embedded in an ISCR1 complex class 1 integron as a novel 4812 bp NDM-1-ISCR1 element. The element was found to be able to self excise to become a free form, which may provide a new vehicle for NDM-1 dissemination. This mechanism could greatly accelerate the spread of NDM-1 mediated broad spectrum β-lactam resistance.
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Affiliation(s)
- Juan Li
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, China CDC, Changping, Beijing, China
| | - Ruiting Lan
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia
| | - Yanwen Xiong
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, China CDC, Changping, Beijing, China
| | - Changyun Ye
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, China CDC, Changping, Beijing, China
| | - Min Yuan
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, China CDC, Changping, Beijing, China
| | - Xinfeng Liu
- Gansu Provincial Center for Disease Control and Prevention, Lanzhou, Gansu Province, China
| | - Xia Chen
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, China CDC, Changping, Beijing, China
| | - Deshan Yu
- Gansu Provincial Center for Disease Control and Prevention, Lanzhou, Gansu Province, China
| | - Bin Liu
- College of Life Sciences, Nankai University, Tianjin, China
| | - Wenchao Lin
- College of Life Sciences, Nankai University, Tianjin, China
| | - Xuemei Bai
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, China CDC, Changping, Beijing, China
| | - Yan Wang
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, China CDC, Changping, Beijing, China
| | - Qiangzheng Sun
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, China CDC, Changping, Beijing, China
| | - Yiting Wang
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, China CDC, Changping, Beijing, China
| | - Hongqing Zhao
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, China CDC, Changping, Beijing, China
| | - Qiong Meng
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, China CDC, Changping, Beijing, China
| | - Qiang Chen
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, China CDC, Changping, Beijing, China
| | - Ailan Zhao
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, China CDC, Changping, Beijing, China
| | - Jianguo Xu
- State Key Laboratory for Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, National Institute for Communicable Disease Control and Prevention, China CDC, Changping, Beijing, China
- * E-mail:
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13
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Comparison of net growth of Shiga toxin-producing Escherichia coli strains of serogroups O26, O103, and O157 in ground meat at different temperatures. Eur Food Res Technol 2013. [DOI: 10.1007/s00217-013-2104-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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14
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Occurrence of potentially human-pathogenic Escherichia coli O103 in Norwegian sheep. Appl Environ Microbiol 2013; 79:7502-9. [PMID: 24077709 DOI: 10.1128/aem.01825-13] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The investigation of an outbreak of hemorrhagic-uremic syndrome in Norway in 2006 indicated that the outbreak strain Escherichia coli O103:H25 could originate from sheep. A national survey of the Norwegian sheep population was performed, with the aim of identifying and describing a possible reservoir of potentially human-pathogenic E. coli O103, in particular of the H types 2 and 25. The investigation of fecal samples from 585 sheep flocks resulted in 1,222 E. coli O103 isolates that were analyzed for the presence of eae and stx genes, while a subset of 369 isolates was further examined for flagellar antigens (H typing), stx subtypes, bfpA, astA, and molecular typing by pulsed-field gel electrophoresis (PFGE). The total ovine E. coli O103 serogroup was genetically diverse by numbers of H types, virulotypes, and PFGE banding patterns identified, although a tendency of clustering toward serotypes was seen. The flocks positive for potentially human-pathogenic E. coli O103 were geographically widely distributed, and no association could be found with county or geographical region. The survey showed that eae-negative, stx-negative E. coli O103, probably nonpathogenic to humans, is very common in sheep, with 27.5% of flocks positive. Moreover, the study documented a low prevalence (0.7%) of potentially human-pathogenic Shiga toxin-producing E. coli O103:H2, while STEC O103:H25 was not detected. However, 3.1% and 5.8% of the flocks were positive for enteropathogenic E. coli O103 belonging to H types 2 and 25, respectively. These isolates are of concern as potential human pathogens by themselves but more importantly as possible precursors for human-pathogenic STEC.
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15
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Cordeiro F, da Silva RIK, Vargas-Stampe TLZ, Cerqueira AMF, Andrade JRC. Cell invasion and survival of Shiga toxin-producing Escherichia coli within cultured human intestinal epithelial cells. MICROBIOLOGY-SGM 2013; 159:1683-1694. [PMID: 23704791 DOI: 10.1099/mic.0.064204-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Shiga toxin-producing Escherichia coli (STEC) cause severe human infections and their virulence abilities are not fully understood. Cattle are a key reservoir, and the terminal rectum is the principal site of bacterial carriage. Most STEC possess a pathogenicity island termed the locus of enterocyte effacement (LEE). Nonetheless, LEE-negative STEC have been associated with disease. We found that invasion of LEE-positive and LEE-negative strains was higher for human enterocytic cell lines and for undifferentiated Caco-2 cells. Intracellular bacteria could be detected as early as 5 min after infection and transmission electron microscopy showed bacteria within membrane-bound vacuoles. STEC invasion depended on actin microfilaments and protein kinases. Scanning electron microscopy revealed that bacterial entry was not associated with membrane ruffling. Absence of macropinocytosis or actin rearrangement at the entry points suggests a zipper-like entry mechanism. Disruption of the tight junction by EGTA enhanced invasion of Caco-2 monolayers, and bacterial invasion mostly proceeded through the basolateral pole of enterocytes. STEC persisted within Caco-2 cells for up to 96 h without cell death and bacterial viability increased after 48 h, suggesting intracellular multiplication. The relatively harmless intracellular localization of STEC can be an efficient strategy to prevent its elimination from the bovine intestinal tract.
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Affiliation(s)
- Fabiana Cordeiro
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade do Estado do Rio de Janeiro, Rio de Janeiro 20551-030, Brazil
| | - Rita Ifuoe K da Silva
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade do Estado do Rio de Janeiro, Rio de Janeiro 20551-030, Brazil
| | - Thaís L Z Vargas-Stampe
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade do Estado do Rio de Janeiro, Rio de Janeiro 20551-030, Brazil
| | - Aloysio M F Cerqueira
- Departamento de Microbiologia e Parasitologia, Universidade Federal Fluminense, Niterói 24210-130, Brazil
| | - João R C Andrade
- Departamento de Microbiologia, Imunologia e Parasitologia, Universidade do Estado do Rio de Janeiro, Rio de Janeiro 20551-030, Brazil
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16
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Horcajo P, Domínguez-Bernal G, Carrión J, De La Fuente R, Ruiz-Santa-Quiteria JA, Orden JA. Differences in virulence gene expression between atypical enteropathogenic Escherichia coli strains isolated from diarrheic and healthy ruminants. CANADIAN JOURNAL OF VETERINARY RESEARCH = REVUE CANADIENNE DE RECHERCHE VETERINAIRE 2013; 77:158-160. [PMID: 24082409 PMCID: PMC3605933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Accepted: 06/07/2012] [Indexed: 06/02/2023]
Abstract
Differences in the pathogenicity of atypical enteropathogenic Escherichia coli (EPEC) strains may be due, at least partially, to different expression patterns of some virulence genes. To investigate this hypothesis, the virulence gene expression patterns of 6 atypical EPEC strains isolated from healthy and diarrheic ruminants were compared using quantitative real-time reverse transcription polymerase chain reaction after growing the bacteria in culture medium alone or after binding it to HeLa epithelial cells. Some virulence genes in strains from diarrheic animals were upregulated relative to their expression in strains from healthy animals. When bacteria were cultured in the presence of HeLa cells, the ehxA and efa1/lifA genes, previously associated with the production of diarrhea, were expressed at higher levels in strains from diarrheic animals than in strains from healthy animals. Thus, the expression levels of some virulence genes may help determine which atypical EPEC strains cause diarrhea in ruminants.
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Affiliation(s)
| | | | | | | | | | - José A. Orden
- Address all correspondence to Dr. José A. Orden; telephone: + 34 91 394 3704; fax: + 34 91 394 3795; e-mail:
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17
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Nakhjavani FA, Emaneini M, Hosseini H, Iman-Eini H, Aligholi M, Jabalameli F, Haghi-Ashtiani MT, Taherikalani M, Mirsalehian A. Molecular analysis of typical and atypical enteropathogenic Escherichia coli (EPEC) isolated from children with diarrhoea. J Med Microbiol 2012; 62:191-195. [PMID: 23065543 DOI: 10.1099/jmm.0.046516-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Diarrhoea continues to be one of the most common causes of morbidity and mortality among infants and children in developing countries. To investigate the incidence, antimicrobial resistance and genetic relationships of enteropathogenic Escherichia coli (EPEC) in children with diarrhoea, a total of 612 stool specimens were collected in Tehran, Iran, and cultured to isolate strains of EPEC. The disc diffusion method was used to determine the susceptibility of the isolates according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. The presence of eae, stx and bfp-A genes was determined by PCR. The genetic relationships between EPEC isolates were determined by pulsed-field gel electrophoresis (PFGE). Out of the 412 strains of E. coli obtained from 612 diarrhoeal stool specimens, 23 (5.6 %) were identified as EPEC, of which seven (30.4 %) were classified as typical strains of EPEC and 16 (69.6 %) were classified as atypical. Out of the 23 EPEC isolates, 69.5 % were resistant to ampicillin, 39.1 % were resistant to tetracycline and cotrimoxazole, 30.4 % were resistant to cefpodoxime, ceftazidime, ceftriaxone and aztreonam, and 26.1 % were resistant to imipenem. The isolates were classified into 21 pulsotypes by PFGE profiles. The present study shows that typical and atypical EPEC isolates displayed considerable heterogeneity in PFGE profiles and EPEC infections were only sporadic in Tehran. Overall 69 % of isolates were resistant to at least one of the antibiotics tested.
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Affiliation(s)
- Farrokh Akbari Nakhjavani
- Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, PO Box 14155-6447, Tehran 14174, Iran
| | - Mohammad Emaneini
- Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, PO Box 14155-6447, Tehran 14174, Iran
| | - Hossein Hosseini
- Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, PO Box 14155-6447, Tehran 14174, Iran
| | - Hossein Iman-Eini
- School of ECE, College of Engineering, University of Tehran, PO Box 11365-4563, Tehran 14174, Iran
| | - Marzieh Aligholi
- Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, PO Box 14155-6447, Tehran 14174, Iran
| | - Fereshteh Jabalameli
- Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, PO Box 14155-6447, Tehran 14174, Iran
| | - Mohammad Taghi Haghi-Ashtiani
- Department of Pathology, Children's Medical Center, School of Medicine, Tehran University of Medical Sciences, PO Box 14155-6447, Tehran 14174, Iran
| | - Morovat Taherikalani
- Department of Microbiology, School of Medicine, Ilam University of Medical Sciences, Ilam 69315, Iran
| | - Akbar Mirsalehian
- Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, PO Box 14155-6447, Tehran 14174, Iran
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18
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Molecular characterization reveals three distinct clonal groups among clinical shiga toxin-producing Escherichia coli strains of serogroup O103. J Clin Microbiol 2012; 50:2894-900. [PMID: 22718945 DOI: 10.1128/jcm.00789-12] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) is one of the most important groups of food-borne pathogens, and STEC strains belonging to the serotype O103:H2 can cause diarrhea, hemorrhagic colitis, and hemolytic-uremic syndrome in humans. STEC O103:non-H2 strains are also sometimes isolated from human patients, but their genetic characteristics and role in significant human enteric disease are not yet understood. Here, we investigated 17 STEC O103:non-H2 strains, including O103:H11, O103:H25, O103:HUT (UT [untypeable]), and O103:H- (nonmotile) isolated in Japan, and their characteristics were compared to those of STEC O103:H2 and other serotype STEC strains. Sequence analyses of fliC and eae genes revealed that strains possessed any of the following combinations: fliC-H2/eae-epsilon, fliC-H11/eae-beta1, and fliC-H25/eae-theta, where fliC-H2, -H11, and -H25 indicate fliC genes encoding H2, H11, and H25 flagella antigens, respectively, and eae-epsilon, -beta1, and -theta indicate eae genes encoding epsilon, beta1, and theta subclass intimins, respectively. Phylogenetic analysis based on the sequences of seven housekeeping genes demonstrated that the O103:H11/[fliC-H11] and O103:H25/[fliC-H25] strains formed two distinct groups, different from that of the O103:H2/[fliC-H2] strains. Interestingly, a group consisting of O103:H11 strains was closely related to STEC O26:H11, which is recognized as a most important non-O157 serotype, suggesting that the STEC O103:H11 and STEC O26:H11 clones evolved from a common ancestor. The multiplex PCR system for the rapid typing of STEC O103 strains described in the present study may aid clinical and epidemiological studies of the STEC O103:H2, O103:H11, and O103:H25 groups. In addition, our data provide further insights into the high variability of STEC stains with emerging new serotypes.
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19
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Horcajo P, Domínguez-Bernal G, de la Fuente R, Ruiz-Santa-Quiteria JA, Blanco JE, Blanco M, Mora A, Dahbi G, López C, Puentes B, Alonso MP, Blanco J, Orden JA. Comparison of ruminant and human attaching and effacing Escherichia coli (AEEC) strains. Vet Microbiol 2012; 155:341-8. [DOI: 10.1016/j.vetmic.2011.08.034] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2011] [Revised: 08/25/2011] [Accepted: 08/31/2011] [Indexed: 11/25/2022]
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20
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Rodas C, Klena JD, Nicklasson M, Iniguez V, Sjöling Å. Clonal relatedness of enterotoxigenic Escherichia coli (ETEC) strains expressing LT and CS17 isolated from children with diarrhoea in La Paz, Bolivia. PLoS One 2011; 6:e18313. [PMID: 22140423 PMCID: PMC3226562 DOI: 10.1371/journal.pone.0018313] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2010] [Accepted: 03/03/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Enterotoxigenic Escherichia coli (ETEC) is a major cause of traveller's and infantile diarrhoea in the developing world. ETEC produces two toxins, a heat-stable toxin (known as ST) and a heat-labile toxin (LT) and colonization factors that help the bacteria to attach to epithelial cells. METHODOLOGY/PRINCIPAL FINDINGS In this study, we characterized a subset of ETEC clinical isolates recovered from Bolivian children under 5 years of age using a combination of multilocus sequence typing (MLST) analysis, virulence typing, serotyping and antimicrobial resistance test patterns in order to determine the genetic background of ETEC strains circulating in Bolivia. We found that strains expressing the heat-labile (LT) enterotoxin and colonization factor CS17 were common and belonged to several MLST sequence types but mainly to sequence type-423 and sequence type-443 (Achtman scheme). To further study the LT/CS17 strains we analysed the nucleotide sequence of the CS17 operon and compared the structure to LT/CS17 ETEC isolates from Bangladesh. Sequence analysis confirmed that all sequence type-423 strains from Bolivia had a single nucleotide polymorphism; SNP(bol) in the CS17 operon that was also found in some other MLST sequence types from Bolivia but not in strains recovered from Bangladeshi children. The dominant ETEC clone in Bolivia (sequence type-423/SNP(bol)) was found to persist over multiple years and was associated with severe diarrhoea but these strains were variable with respect to antimicrobial resistance patterns. CONCLUSION/SIGNIFICANCE The results showed that although the LT/CS17 phenotype is common among ETEC strains in Bolivia, multiple clones, as determined by unique MLST sequence types, populate this phenotype. Our data also appear to suggest that acquisition and loss of antimicrobial resistance in LT-expressing CS17 ETEC clones is more dynamic than acquisition or loss of virulence factors.
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Affiliation(s)
- Claudia Rodas
- WHO Collaborating Centre for Research on Enterotoxigenic Escherichia coli (ETEC) and Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
- Instituto de Biología Molecular y Biotecnología, Universidad Mayor de San Andrés, Facultad de Ciencias Puras y Naturales, La Paz, Bolivia
| | - John D. Klena
- U.S. Naval Medical Research Unit-3, Clinical Trials and Military Studies Program, Cairo, Egypt
| | - Matilda Nicklasson
- WHO Collaborating Centre for Research on Enterotoxigenic Escherichia coli (ETEC) and Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Volga Iniguez
- Instituto de Biología Molecular y Biotecnología, Universidad Mayor de San Andrés, Facultad de Ciencias Puras y Naturales, La Paz, Bolivia
| | - Åsa Sjöling
- WHO Collaborating Centre for Research on Enterotoxigenic Escherichia coli (ETEC) and Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
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21
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Tzschoppe M, Martin A, Beutin L. A rapid procedure for the detection and isolation of enterohaemorrhagic Escherichia coli (EHEC) serogroup O26, O103, O111, O118, O121, O145 and O157 strains and the aggregative EHEC O104:H4 strain from ready-to-eat vegetables. Int J Food Microbiol 2011; 152:19-30. [PMID: 22071287 DOI: 10.1016/j.ijfoodmicro.2011.10.009] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Revised: 09/16/2011] [Accepted: 10/11/2011] [Indexed: 11/28/2022]
Abstract
Human infections with Enterohaemorrhagic Escherichia coli strains (EHEC) as agents of Haemorrhagic Colitis (HC) and Haemolytic Uraemic Syndrome (HUS) are frequently associated with the consumption of EHEC contaminated foodstuffs of different origins. EHEC O26, O103, O111, O118, O121, O145 and O157 strains are responsible for the majority of HC and HUS cases worldwide. In May 2011, the emerging aggregative EHEC O104:H4 strain caused a large outbreak with high HUS incidence in northern Germany. Contaminated sprouted seeds were suspected to be the vehicles of transmission. The examination of vegetables retailed for raw consumption revealed low numbers of E. coli (<100 cfu/g) together with high titres of Enterobacteriaceae and Pseudomonas (approx. 5.6 × 10⁷ cfu/g). Specific methods of EHEC detection adapted to vegetables are not yet published. Therefore, we have developed a rapid and sensitive method for detecting low EHEC contamination in vegetables (1-10 cfu/25 g) with artificially EHEC contaminated ready-to-eat salads. A 6-hour enrichment period in BRILA-broth was sufficient to detect 1-10 EHEC from spiked samples after plating 0.1 ml portions of enrichment culture on selective TBX-agar and CHROMagar STEC plates that were incubated at 44 °C overnight. Unlike EHEC strains, the growth of bacteria of the plant flora was substantially inhibited at 44 °C. DNA for real-time PCR detection of EHEC characteristic genes (stx(1), stx(2), eae, ehxA, and O-antigen associated) was prepared with bacteria grown on TBX-agar plates. The storage of EHEC inoculated salad samples for 72 h at 6 °C resulted in a significant reduction (mean value 14.6%) of detectable EHEC, suggesting interference of EHEC with the resident plant microflora. CHROMagar STEC was evaluated as a selective medium for the detection of EHEC strains. Growth on CHROMagar STEC was closely associated with EHEC O26:[H11], O111:[H8], O118:H16, O121:[H19], O145:[H28], O157:[H7] and aggregative EHEC O104:H4 strains and with the presence of the terB gene (tellurite resistance). TerB sequences were found in 87.2% of 235 EHEC but only in only 12.5% of 567 non-EHEC strains. EHEC strains which did not grow on CHROMagar STEC were negative for terB as frequently observed with EHEC O103:H2 (52.9%) and sorbitol-fermenting O157:NM strains (100%). The enrichment and detection method was applied in the examination of sprouted seeds incriminated as vehicles in the EHEC O104:H4 outbreak in Germany. Aggregative EHEC O104:H4 could be detected and isolated from a sample of sprouted seeds which was suspected as vector of transmission of EHEC O104 to humans.
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Affiliation(s)
- Markus Tzschoppe
- National Reference Laboratory for Escherichia coli, Unit 41: Microbial Toxins, Germany
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22
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Kerro Dego O, Oliver SP, Almeida RA. Host-pathogen gene expression profiles during infection of primary bovine mammary epithelial cells with Escherichia coli strains associated with acute or persistent bovine mastitis. Vet Microbiol 2011; 155:291-7. [PMID: 21917386 DOI: 10.1016/j.vetmic.2011.08.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Revised: 08/11/2011] [Accepted: 08/16/2011] [Indexed: 01/06/2023]
Abstract
Escherichia coli intramammary infection (IMI) is often acute with local and systemic clinical manifestations that clear within 7 days. However, if not diagnosed early and treated, E. coli IMI could result in generalized systemic reaction and death. Persistent E. coli IMI is characterized by mild clinical manifestations followed by acute episodes of clinical mastitis during lactation. Factors responsible for pathogenesis of E. coli IMI and variation in clinical manifestations are not known. There are studies indicating that the outcome of E. coli IMI is mainly determined by cow factors. However, recent research demonstrated that virulence attributes of E. coli strains have significant impact on the outcome of E. coli IMI. The aims of this study were; (a) to compare gene expression profiles of PBMEC cocultured with strains of E. coli associated with acute or persistent IMI and; (b) to identify genes of E. coli induced during bacterial interaction with PBMEC. Utilizing cDNA we analyzed gene expression patterns of PBMEC cocultured with strains of E. coli using non-treated PBMEC as negative control. We evaluated also expression patterns of virulence associated genes of E. coli after co-culture with PBMEC using qRT-PCR. Our results showed that infection by both strains induced increased expression of pro-inflammatory cytokines, chemokines and innate immune response and apoptosis related genes. Our qRT-PCR results showed significant up-regulation of ler, eae, flic and iutA genes mainly in the strains of E. coli associated with persistent IMI. The pathogenesis and clinical severity of E. coli IMI may be determined by combined effects of host-pathogen factors.
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Affiliation(s)
- O Kerro Dego
- Department of Animal Science, The University of Tennessee, Knoxville, TN 37996, USA
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Abstract
Verotoxin-producing Escherichia coli (VTEC) is annually incriminated in more than 100,000 cases of enteric foodborne human disease and in losses amounting to $US 2.5 billion every year. A number of genotyping methods have been developed to track VTEC infections and determine diversity and evolutionary relationships among these microorganisms. These methods have facilitated monitoring and surveillance of foodborne VTEC outbreaks and early identification of outbreaks or clusters of outbreaks. Pulsed-field gel electrophoresis (PFGE) has been used extensively to track and differentiate VTEC because of its high discriminatory power, reproducibility and ease of standardization. Multiple-locus variable-number tandem-repeats analysis (MLVA) and microarrays are the latest genotyping methods that have been applied to discriminate VTEC. MLVA, a simpler and less expensive method, is proving to have a discriminatory power comparable to that of PFGE. Microarrays are successfully being applied to differentiate VTEC and make inferences on genome diversification. Novel methods that are being evaluated for subtyping VTEC include the detection of single nucleotide polymorphisms and optical mapping. This review discusses the principles, applications, advantages and disadvantages of genotyping methods that have been used to differentiate VTEC strains. These methods have been mainly used to differentiate strains of O157:H7 VTEC and to a lesser extent non-O157 VTEC.
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Affiliation(s)
- M Karama
- Department of Pathobiology, University of Guelph, Guelph, ON, Canada
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Inhibition of the adhesion to catheters of uropathogenic Escherichia coli by sub-inhibitory concentrations of cefotaxime. Eur J Obstet Gynecol Reprod Biol 2011; 155:150-6. [DOI: 10.1016/j.ejogrb.2010.12.034] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2010] [Revised: 12/08/2010] [Accepted: 12/28/2010] [Indexed: 11/24/2022]
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25
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Molecular risk assessment and epidemiological typing of Shiga toxin-producing Escherichia coli by using a novel PCR binary typing system. Appl Environ Microbiol 2011; 77:2458-70. [PMID: 21296939 DOI: 10.1128/aem.02322-10] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) is a zoonotic pathogen that causes diarrheal disease in humans and is of public health concern because of its ability to cause outbreaks and severe disease such as hemorrhagic colitis or hemolytic-uremic syndrome. More than 400 serotypes of STEC have been implicated in outbreaks and sporadic human disease. The aim of this study was to develop a PCR binary typing (P-BIT) system that could be used to aid in risk assessment and epidemiological studies of STEC by using gene targets that would represent a broad range of STEC virulence genes. We investigated the distribution of 41 gene targets in 75 O157 and non-O157 STEC isolates and found that P-BIT provided 100% typeability for isolates, gave a diversity index of 97.33% (compared with 99.28% for XbaI pulsed-field gel electrophoresis [PFGE] typing), and produced 100% discrimination for non-O157 STEC isolates. We identified 24 gene targets that conferred the same level of discrimination and produced the same cluster dendrogram as the 41 gene targets initially examined. P-BIT clustering identified O157 from non-O157 isolates and identified seropathotypes associated with outbreaks and severe disease. Numerical analysis of the P-BIT data identified several genes associated with human or nonhuman sources as well as high-risk seropathotypes. We conclude that P-BIT is a useful approach for subtyping, offering the advantage of speed, low cost, and potential for strain risk assessment that can be used in tandem with current molecular typing schema for STEC.
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26
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Contreras CA, Ochoa TJ, Ruiz J, Lacher DW, Rivera FP, Saenz Y, Chea-Woo E, Zavaleta N, Gil AI, Lanata CF, Huicho L, Maves RC, Torres C, DebRoy C, Cleary TG. Phylogenetic relationships of Shiga toxin-producing Escherichia coli isolated from Peruvian children. J Med Microbiol 2011; 60:639-646. [PMID: 21292859 DOI: 10.1099/jmm.0.026666-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The aim of this study was to determine the prevalence, virulence factors (stx, eae, ehxA and astA) and phylogenetic relationships [PFGE and multilocus sequence typing (MLST)] of Shiga toxin-producing Escherichia coli (STEC) strains isolated from four previous cohort studies in 2212 Peruvian children aged <36 months. STEC prevalence was 0.4 % (14/3219) in diarrhoeal and 0.6 % (15/2695) in control samples. None of the infected children developed haemolytic uraemic syndrome (HUS) or other complications of STEC. stx1 was present in 83 % of strains, stx2 in 17 %, eae in 72 %, ehxA in 59 % and astA in 14 %. The most common serotype was O26 : H11 (14 %) and the most common seropathotype was B (45 %). The strains belonged mainly to phylogenetic group B1 (52 %). The distinct combinations of alleles across the seven MLST loci were used to define 13 sequence types among 19 STEC strains. PFGE typing of 20 STEC strains resulted in 19 pulsed-field patterns. Comparison of the patterns revealed 11 clusters (I-XI), each usually including strains belonging to different serotypes; one exception was cluster VI, which gathered exclusively seven strains of seropathotype B, clonal group enterohaemorrhagic E. coli (EHEC) 2 and phylogenetic group B1. In summary, STEC prevalence was low in Peruvian children with diarrhoea in the community setting. The strains were phylogenetically diverse and associated with mild infections. However, additional studies are needed in children with bloody diarrhoea and HUS.
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Affiliation(s)
- C A Contreras
- Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - T J Ochoa
- University of Texas School of Public Health, Houston, USA.,Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - J Ruiz
- CIBERESP, Barcelona, Spain.,Centre de Recerca en Salut Internacional de Barcelona, Hospital Clinic/Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain
| | - D W Lacher
- US Food and Drug Administration, Laurel, Maryland, USA
| | - F P Rivera
- Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Y Saenz
- Área de Microbiología Molecular, Centro de Investigación Biomédica La Rioja, Logroño, Spain
| | - E Chea-Woo
- Universidad Peruana Cayetano Heredia, Lima, Peru
| | - N Zavaleta
- Instituto de Investigación Nutricional, Lima, Peru
| | - A I Gil
- Instituto de Investigación Nutricional, Lima, Peru
| | - C F Lanata
- Escuela de Medicina, Universidad Peruana de Ciencias Aplicadas, Lima, Peru.,Instituto de Investigación Nutricional, Lima, Peru
| | - L Huicho
- Instituto Nacional de Salud del Niño, Lima, Peru.,Universidad Nacional Mayor de San Marcos, Lima, Peru.,Universidad Peruana Cayetano Heredia, Lima, Peru
| | - R C Maves
- US Naval Medical Research Center Detachment, Department of Bacteriology, Lima, Peru
| | - C Torres
- Área de Microbiología Molecular, Centro de Investigación Biomédica La Rioja, Logroño, Spain
| | - C DebRoy
- E. coli Reference Center, Department of Veterinary and Biomedical Sciences, Pennsylvania State University, Pennsylvania, USA
| | - T G Cleary
- University of Texas School of Public Health, Houston, USA
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Olvera A, Pina S, Macedo N, Oliveira S, Aragon V, Bensaid A. Identification of potentially virulent strains of Haemophilus parasuis using a multiplex PCR for virulence-associated autotransporters (vtaA). Vet J 2011; 191:213-8. [PMID: 21247786 DOI: 10.1016/j.tvjl.2010.12.014] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2010] [Revised: 11/19/2010] [Accepted: 12/11/2010] [Indexed: 10/18/2022]
Abstract
Haemophilus parasuis is the aetiological agent of Glässer's disease and is also a commensal of the upper respiratory tract of pigs. Trimeric autotransporter (vtaA) genes have been identified in H. parasuis and divided into three groups on the basis of the translocator domain sequence. In this study, group 3 vtaA genes were demonstrated by PCR in all 157 H. parasuis isolates tested. Group 1 vtaA genes were associated with virulent strains; 52/54 (96%) group 1 vtaA negative field isolates were isolated from the nasal passages of healthy animals, whereas no group 1 vtaA negative field isolates were isolated from cases of Glässer's disease. There was an association between absence of group 1 vtaA, sensitivity to phagocytosis and serum and classification of isolates into nasal cluster C by multilocus sequence typing. A multiplex PCR was developed for diagnosis of H. parasuis at the species level (group 3 vtaA positive) and to differentiate putative non-virulent strains (group 1 vtaA negative). When applied to field samples, the PCR confirmed a high prevalence of H. parasuis in conventionally farmed pigs and demonstrated that almost half of the animals carried potentially virulent strains.
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Affiliation(s)
- Alex Olvera
- Centre de Recerca en Sanitat Animal (CReSA), UAB-IRTA, Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
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Vinogradov E, Maclean LL, Perry MB. Structural determination of the O-antigenic polysaccharide of enteropathogenic Escherichia coli O103:H2. Can J Microbiol 2010; 56:366-72. [PMID: 20555398 DOI: 10.1139/w10-015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The structure of the antigenic O-polysaccharide isolated from the lipopolysaccharide produced by enterohemorrhagic Escherichia coli O103:H2 was determined and shown to be composed of d-glucose (1 part), 2-acetamido-2-deoxy-d-glucose (2 parts), 2-acetamido-2-deoxy-d-galactose (1 part), and 3-deoxy-3-(R)-3-hydroxybutyramido-d-fucose (1 part). From the results of methylation analysis, Smith-type periodate oxidation degradation studies, and the use of one- and two-dimensional (1)H and (13)C NMR spectroscopy, the O-polysaccharide antigen was found to be an unbranched polymer of a repeating pentasaccharide unit having the following structure: -->2)-Beta-d-Glcp-(1-->2)-Beta-d-Fucp3NBu-(1-->6)-alpha-d-GlcpNAc-(1-->4)-alpha-d-GalpNAc-(1-->3)-Beta-d-GlcpNAc-(1-->,where Bu is (R)-3-hydroxybutyramido.
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Affiliation(s)
- Evgeny Vinogradov
- Institute for Biological Sciences, National Research Council, 100 Sussex Drive, Ottawa, ON K1A 0R6, Canada
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29
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Creuzburg K, Middendorf B, Mellmann A, Martaler T, Holz C, Fruth A, Karch H, Schmidt H. Evolutionary analysis and distribution of type III effector genes in pathogenic Escherichia coli from human, animal and food sources. Environ Microbiol 2010; 13:439-52. [PMID: 20880329 DOI: 10.1111/j.1462-2920.2010.02349.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Molecular analysis of Shiga toxin-producing Escherichia coli (STEC) from different sources is considered as a major approach to assess their risk potential. However, only limited data are available about the correlation of evolutionary relationship, the presence of major virulence factor genes and the putative risk of an STEC strain for human infection. In this study, we analysed the evolutionary relationship of 136 pathogenic E. coli strains from human, animal and food sources by multi-locus sequence typing (MLST) and molecular subtyping of their Shiga toxin (stx) and intimin (eae) genes. Moreover, the distribution of three type III effector genes, encoded within the locus of enterocyte effacement (LEE), and 16 effector genes, which are encoded outside the LEE, was analysed. One hundred and five strains from different sources harboured 5-15 of the analysed non-LEE-encoded effector genes. In 101 of these strains, the LEE genes eae, map, espF and espG were present simultaneously. Thirty-one isolates deriving mainly from food and patients suffering from haemolytic uraemic syndrome (HUS) were eae-negative and did not carry any of the analysed effector genes. By combination of MLST and virulence gene data, we defined five genetic clusters. Within these clusters a clear-cut affiliation of particular sequence types and the occurrence of certain effector genes was observed. However, in contrast to other studies, a significant correlation between the amount and type of effector genes and the risk to cause HUS could not be demonstrated.
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Affiliation(s)
- Kristina Creuzburg
- Department of Food Microbiology, Institute of Food Science and Biotechnology, Garbenstraße 28, University of Hohenheim, 70599 Stuttgart, Germany
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30
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dos Santos LF, Irino K, Vaz TMI, Guth BEC. Set of virulence genes and genetic relatedness of O113 : H21 Escherichia coli strains isolated from the animal reservoir and human infections in Brazil. J Med Microbiol 2010; 59:634-640. [DOI: 10.1099/jmm.0.015263-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Escherichia coli strains of serotype O113 : H21 are commonly described as belonging to a Shiga toxin (Stx)-producing E. coli (STEC) pathotype worldwide. Albeit this STEC serotype is frequently identified among cattle and other domestic animals, to the best of our knowledge no human infections associated with STEC O113 : H21 have been registered in Brazil to date. Here, we report the virulence profile and genetic relatedness of a collection of O113 : H21 E. coli strains mainly isolated from the animal reservoir aimed at determining their potential as human pathogens. The strains from the animal reservoir (n=34) were all classified as STEC, whereas the few isolates recovered so far from human diarrhoea (n=3) lacked stx genes. Among the STEC, the stx
2d-activatable gene was identified in 85 % of the strains that also carried lpfA
O113, iha, saa, ehxA, subAB, astA, cdt-V, espP, espI and epeA; the human strains harboured only lpfA
O113, iha and astA. All the strains except one, isolated from cattle, were genetically classified as phylogenetic group B1. High mass plasmids were observed in 25 isolates, but only in the STEC group were these plasmids confirmed as the STEC O113 megaplasmid (pO113). Many closely related subgroups (more than 80 % similarity) were identified by PFGE, with human isolates clustering in a subgroup separate from most of the animal isolates. In conclusion, potentially pathogenic O113 : H21 STEC isolates carrying virulence markers in common with O113 : H21 clones associated with haemolytic uraemic syndrome cases in other regions were demonstrated to occur in the natural reservoir in our settings, and therefore the risk represented by them to public health should be carefully monitored.
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Affiliation(s)
- Luis Fernando dos Santos
- Departament of Microbiology, Immunology and Parasitology, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Kinue Irino
- Section of Bacteriology, Adolfo Lutz Institute, São Paulo, Brazil
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31
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Döpfer D, Sekse C, Beutin L, Solheim H, van der Wal F, de Boer A, Slettemeås J, Wasteson Y, Urdahl A. Pathogenic potential and horizontal gene transfer in ovine gastrointestinalEscherichia coli. J Appl Microbiol 2010; 108:1552-62. [DOI: 10.1111/j.1365-2672.2009.04575.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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32
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Mordhorst IL, Claus H, Ewers C, Lappann M, Schoen C, Elias J, Batzilla J, Dobrindt U, Wieler LH, Bergfeld AK, Mühlenhoff M, Vogel U. O-acetyltransferase geneneuOis segregated according to phylogenetic background and contributes to environmental desiccation resistance inEscherichia coliK1. Environ Microbiol 2009; 11:3154-65. [DOI: 10.1111/j.1462-2920.2009.02019.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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33
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Moura RA, Sircili MP, Leomil L, Matté MH, Trabulsi LR, Elias WP, Irino K, Pestana de Castro AF. Clonal relationship among atypical enteropathogenic Escherichia coli strains isolated from different animal species and humans. Appl Environ Microbiol 2009; 75:7399-408. [PMID: 19801470 PMCID: PMC2786407 DOI: 10.1128/aem.00636-09] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Forty-nine typical and atypical enteropathogenic Escherichia coli (EPEC) strains belonging to different serotypes and isolated from humans, pets (cats and dogs), farm animals (bovines, sheep, and rabbits), and wild animals (monkeys) were investigated for virulence markers and clonal similarity by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). The virulence markers analyzed revealed that atypical EPEC strains isolated from animals have the potential to cause diarrhea in humans. A close clonal relationship between human and animal isolates was found by MLST and PFGE. These results indicate that these animals act as atypical EPEC reservoirs and may represent sources of infection for humans. Since humans also act as a reservoir of atypical EPEC strains, the cycle of mutual infection of atypical EPEC between animals and humans, mainly pets and their owners, cannot be ruled out since the transmission dynamics between the reservoirs are not yet clearly understood.
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Affiliation(s)
- Rodrigo A. Moura
- Laboratory of Human and Veterinary Bacteriology, Biomedical Sciences Institute, University of São Paulo, São Paulo, SP, Brazil, Laboratory of Bacteriology, Butantan Institute, São Paulo, SP, Brazil, Laboratory of Public Health, Public Health School, University of São Paulo, São Paulo, SP, Brazil, Adolfo Lutz Institute, São Paulo, SP, Brazil
| | - Marcelo P. Sircili
- Laboratory of Human and Veterinary Bacteriology, Biomedical Sciences Institute, University of São Paulo, São Paulo, SP, Brazil, Laboratory of Bacteriology, Butantan Institute, São Paulo, SP, Brazil, Laboratory of Public Health, Public Health School, University of São Paulo, São Paulo, SP, Brazil, Adolfo Lutz Institute, São Paulo, SP, Brazil
| | - Luciana Leomil
- Laboratory of Human and Veterinary Bacteriology, Biomedical Sciences Institute, University of São Paulo, São Paulo, SP, Brazil, Laboratory of Bacteriology, Butantan Institute, São Paulo, SP, Brazil, Laboratory of Public Health, Public Health School, University of São Paulo, São Paulo, SP, Brazil, Adolfo Lutz Institute, São Paulo, SP, Brazil
| | - Maria Helena Matté
- Laboratory of Human and Veterinary Bacteriology, Biomedical Sciences Institute, University of São Paulo, São Paulo, SP, Brazil, Laboratory of Bacteriology, Butantan Institute, São Paulo, SP, Brazil, Laboratory of Public Health, Public Health School, University of São Paulo, São Paulo, SP, Brazil, Adolfo Lutz Institute, São Paulo, SP, Brazil
| | - Luiz R. Trabulsi
- Laboratory of Human and Veterinary Bacteriology, Biomedical Sciences Institute, University of São Paulo, São Paulo, SP, Brazil, Laboratory of Bacteriology, Butantan Institute, São Paulo, SP, Brazil, Laboratory of Public Health, Public Health School, University of São Paulo, São Paulo, SP, Brazil, Adolfo Lutz Institute, São Paulo, SP, Brazil
| | - Waldir P. Elias
- Laboratory of Human and Veterinary Bacteriology, Biomedical Sciences Institute, University of São Paulo, São Paulo, SP, Brazil, Laboratory of Bacteriology, Butantan Institute, São Paulo, SP, Brazil, Laboratory of Public Health, Public Health School, University of São Paulo, São Paulo, SP, Brazil, Adolfo Lutz Institute, São Paulo, SP, Brazil
| | - Kinue Irino
- Laboratory of Human and Veterinary Bacteriology, Biomedical Sciences Institute, University of São Paulo, São Paulo, SP, Brazil, Laboratory of Bacteriology, Butantan Institute, São Paulo, SP, Brazil, Laboratory of Public Health, Public Health School, University of São Paulo, São Paulo, SP, Brazil, Adolfo Lutz Institute, São Paulo, SP, Brazil
| | - Antonio F. Pestana de Castro
- Laboratory of Human and Veterinary Bacteriology, Biomedical Sciences Institute, University of São Paulo, São Paulo, SP, Brazil, Laboratory of Bacteriology, Butantan Institute, São Paulo, SP, Brazil, Laboratory of Public Health, Public Health School, University of São Paulo, São Paulo, SP, Brazil, Adolfo Lutz Institute, São Paulo, SP, Brazil
- Corresponding author. Mailing address: Departamento de Microbiologia, Instituto de Ciências Biomédicas, Avenida Prof. Lineu Prestes 1374, 05508-900 São Paulo, SP, Brazil. Phone: 5511 3091-7298. Fax: 5511 3091-7354. E-mail:
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Morato EP, Leomil L, Beutin L, Krause G, Moura RA, Pestana de Castro AF. Domestic cats constitute a natural reservoir of human enteropathogenic Escherichia coli types. Zoonoses Public Health 2009; 56:229-37. [PMID: 19068073 DOI: 10.1111/j.1863-2378.2008.01190.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Feces of 70 diarrhoeic and 230 non-diarrhoeic domestic cats from Sao Paulo, Brazil were investigated for enteropathogenic (EPEC), enterohaemorrhagic (EHEC) and enterotoxigenic (ETEC) Escherichia coli types. While ETEC and EHEC strains were not found, 15 EPEC strains were isolated from 14 cats, of which 13 were non-diarrhoeic, and one diarrhoeic. None of 15 EPEC strains carried the bfpA gene or the EPEC adherence factor plasmid, indicating atypical EPEC types. The EPEC strains were heterogeneous with regard to intimin types, such as eae-theta (three strains), eae-kappa (n = 3), eae-alpha1 (n = 2), eae-iota (n = 2), one eae-alpha2, eae-beta1 and eae-eta each, and two were not typeable. The majority of the EPEC isolates adhered to HEp-2 cells in a localized adherence-like pattern and were positive for fluorescence actin staining. The EPEC strains belonged to 12 different serotypes, including O111:H25 and O125:H6, which are known to be pathogens in humans. Multi locus sequence typing revealed a close genetic similarity between the O111:H25 and O125:H6 strains from cats, dogs and humans. Our results show that domestic cats are colonized by EPEC, including serotypes previously described as human pathogens. As these EPEC strains are also isolated from humans, a cycle of mutual infection by EPEC between cats and its households cannot be ruled out, though the transmission dynamics among the reservoirs are not yet understood clearly.
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Affiliation(s)
- E P Morato
- Departamento de Microbiologia, Universidade de São Paulo, SP, Brazil
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35
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Bruant G, Zhang Y, Garneau P, Wong J, Laing C, Fairbrother JM, Gannon VPJ, Harel J. Two distinct groups of porcine enteropathogenic Escherichia coli strains of serogroup O45 are revealed by comparative genomic hybridization and virulence gene microarray. BMC Genomics 2009; 10:402. [PMID: 19709428 PMCID: PMC2749873 DOI: 10.1186/1471-2164-10-402] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2009] [Accepted: 08/26/2009] [Indexed: 11/14/2022] Open
Abstract
Background Porcine enteropathogenic Escherichia coli (PEPEC) strains of serogroup O45 cause post-weaning diarrhea and produce characteristic attaching and effacing (A/E) lesions. Most O45 PEPEC strains possess the locus of enterocyte effacement (LEE), encoding the virulence factors required for production of A/E lesions, and often possess the paa gene, which is thought to contribute to the early stages of PEPEC pathogenicity. In this study, nine O45 PEPEC strains and a rabbit enteropathogenic (REPEC) strain, known to produce A/E lesions in vivo, were characterized using an E. coli O157-E. coli K12 whole genome microarray and a virulence gene-specific microarray, and by PCR experiments. Results Based on their virulence gene profiles, the 10 strains were considered to be atypical EPEC. The differences in their genomes pointed to the identification of two distinct evolutionary groups of O45 PEPEC, Groups I and II, and provided evidence for a contribution of these genetic differences to their virulence in pigs. Group I included the REPEC strain and four O45 PEPEC strains known to induce severe A/E lesions in challenged pigs whereas Group II was composed of the five other O45 PEPEC strains, which induced less severe or no A/E lesions in challenged pigs. Significant differences between Groups I and II were found with respect to the presence or absence of 50 O-Islands (OIs) or S-loops and 13 K-islands (KIs) or K-loops, including the virulence-associated islands OI#1 (S-loop#1), OI#47 (S-loop#71), OI#57 (S-loop#85), OI#71 (S-loop#108), OI#115, OI#122, and OI#154 (S-loop#253). Conclusion We have genetically characterized a collection of O45 PEPEC strains and classified them into two distinct groups. The differences in their virulence gene and genomic island content may influence the pathogenicity of O45 PEPEC strains, and explain why Group I O45 PEPEC strains induced more severe A/E lesions in explants and challenged pigs than Group II strains.
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Affiliation(s)
- Guillaume Bruant
- Groupe de Recherche sur les Maladies Infectieuses du Porc, Faculté de médecine vétérinaire, Université de Montréal, 3200 rue Sicotte, Saint-Hyacinthe, Québec J2S 7C6, Canada.
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Assessment of Shiga toxin-producing Escherichia coli isolates from wildlife meat as potential pathogens for humans. Appl Environ Microbiol 2009; 75:6462-70. [PMID: 19700552 DOI: 10.1128/aem.00904-09] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
A total of 140 Shiga toxin-producing Escherichia coli (STEC) strains from wildlife meat (deer, wild boar, and hare) isolated in Germany between 1998 and 2006 were characterized with respect to their serotypes and virulence markers associated with human pathogenicity. The strains grouped into 38 serotypes, but eight O groups (21, 146, 128, 113, 22, 88, 6, and 91) and four H types (21, 28, 2, and 8) accounted for 71.4% and 75.7% of all STEC strains from game, respectively. Eighteen of the serotypes, including enterohemorrhagic E. coli (EHEC) O26:[H11] and O103:H2, were previously found to be associated with human illness. Genes linked to high-level virulence for humans (stx(2), stx(2d), and eae) were present in 46 (32.8%) STEC strains from game. Fifty-four STEC isolates from game belonged to serotypes which are frequently found in human patients (O103:H2, O26:H11, O113:H21, O91:H21, O128:H2, O146:H21, and O146:H28). These 54 STEC isolates were compared with 101 STEC isolates belonging to the same serotypes isolated from farm animals, from their food products, and from human patients. Within a given serotype, most STEC strains were similar with respect to their stx genotypes and other virulence attributes, regardless of origin. The 155 STEC strains were analyzed for genetic similarity by XbaI pulsed-field gel electrophoresis. O103:H2, O26:H11, O113:H21, O128:H2, and O146:H28 STEC isolates from game were 85 to 100% similar to STEC isolates of the same strains from human patients. By multilocus sequence typing, game EHEC O103:H2 strains were attributed to a clonal lineage associated with hemorrhagic diseases in humans. The results from our study indicate that game animals represent a reservoir for and a potential source of human pathogenic STEC and EHEC strains.
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Molecular analysis of virulence profiles and Shiga toxin genes in food-borne Shiga toxin-producing Escherichia coli. Appl Environ Microbiol 2009; 75:6187-97. [PMID: 19684176 DOI: 10.1128/aem.00874-09] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
In this study, 75 Shiga toxin (Stx)-producing Escherichia coli (STEC) strains originating from foods (n = 73) and drinking water (n = 2) were analyzed for their stx genotype, as well as for further chromosome-, phage-, and plasmid-encoded virulence factors. A broad spectrum of stx genes was detected. Fifty-three strains (70.7%) contained stx(2) or stx(2) variants, including stx(2d), mucus-activatable stx(2d), stx(2e), and stx(2g). Seven strains (9.3%) harbored stx(1) or stx(1c), and 15 strains (20.0%) carried both stx(2) and/or stx(2) variants and stx(1) or stx(1c). Beside stx, the most abundant accessory virulence markers in STEC food isolates were iha (57.3%), ehxA (40.0%), espP (28.0%), and subAB (25.3%). Only four strains were eae positive; three of these belonged to the serogroups O26, O103, and O157 and contained a typical enterohemorrhagic E. coli virulence spectrum. The results of this study show that a number of STEC strains that occur in foods appear to be pathogenic for humans, based on their virulence profiles. Analysis of stx subtypes and detection of additional virulence factors in eae-negative strains may help to better assess the risk of such strains for causing human infection.
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Virulence genes and molecular typing of different groups of Escherichia coli O157 strains in cattle. Appl Environ Microbiol 2009; 75:6282-91. [PMID: 19684174 DOI: 10.1128/aem.00873-09] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Characterization of an Escherichia coli O157 strain collection (n = 42) derived from healthy Hungarian cattle revealed the existence of diverse pathotypes. Enteropathogenic E. coli (EPEC; eae positive) appeared to be the most frequent pathotype (n = 22 strains), 11 O157 strains were typical enterohemorrhagic E. coli (EHEC; stx and eae positive), and 9 O157 strains were atypical, with none of the key stx and eae virulence genes detected. EHEC and EPEC O157 strains all carried eae-gamma, tir-gamma, tccP, and paa. Other virulence genes located on the pO157 virulence plasmid and different O islands (O island 43 [OI-43] and OI-122), as well as espJ and espM, also characterized the EPEC and EHEC O157 strains with similar frequencies. However, none of these virulence genes were detected by PCR in atypical O157 strains. Interestingly, five of nine atypical O157 strains produced cytolethal distending toxin V (CDT-V) and carried genes encoding long polar fimbriae. Macro-restriction fragment enzyme analysis (pulsed-field gel electrophoresis) revealed that these E. coli O157 strains belong to four main clusters. Multilocus sequence typing analysis revealed that five housekeeping genes were identical in EHEC and EPEC O157 strains but were different in the atypical O157 strains. These results suggest that the Hungarian bovine E. coli O157 strains represent at least two main clones: EHEC/EPEC O157:H7/NM (nonmotile) and atypical CDT-V-producing O157 strains with H antigens different from H7. The CDT-V-producing O157 strains represent a novel genogroup. The pathogenic potential of these strains remains to be elucidated.
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Production of verotoxin and distribution of O islands 122 and 43/48 among verotoxin-producing Escherichia coli O103:H2 isolates from cattle and humans. Appl Environ Microbiol 2008; 75:268-70. [PMID: 18997029 DOI: 10.1128/aem.01445-08] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
This study investigated variations in the occurrence of markers of O islands 122 and 43/48 and in verotoxin 1 production in 91 verotoxin-producing Escherichia coli (VTEC) O103:H2 strains of bovine and human origins. None of the genes that were investigated appear to be virulence indicators for human O103:H2 VTEC.
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Rapid determination of Escherichia coli O157:H7 lineage types and molecular subtypes by using comparative genomic fingerprinting. Appl Environ Microbiol 2008; 74:6606-15. [PMID: 18791027 DOI: 10.1128/aem.00985-08] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In this study, variably absent or present (VAP) regions discovered through comparative genomics experiments were targeted for the development of a rapid, PCR-based method to subtype and fingerprint Escherichia coli O157:H7. Forty-four VAP loci were analyzed for discriminatory power among 79 E. coli O157:H7 strains of 13 phage types (PT). Twenty-three loci were found to maximize resolution among strains, generating 54 separate fingerprints, each of which contained strains of unique PT. Strains from the three previously identified major E. coli O157:H7 lineages, LSPA6-LI, LSPA6-LI/II, and LSPA6-LII, formed distinct branches on a dendrogram obtained by hierarchical clustering of comparative genomic fingerprinting (CGF) data. By contrast, pulsed-field gel electrophoresis (PFGE) typing generated 52 XbaI digestion profiles that were not unique to PT and did not cluster according to O157:H7 lineage. Our analysis identified a subpopulation comprised of 25 strains from a closed herd of cattle, all of which were of PT87 and formed a cluster distinct from all other E. coli O157:H7 strains examined. CGF found five related but unique fingerprints among the highly clonal herd strains, with two dominant subtypes characterized by a shift from the presence of locus fprn33 to its absence. CGF had equal resolution to PFGE typing but with greater specificity, generating fingerprints that were unique among phenotypically related E. coli O157:H7 lineages and PT. As a comparative genomics typing method that is amenable for use in high-throughput platforms, CGF may be a valuable tool in outbreak investigations and strain characterization.
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Phenotypic and genotypic characterization of verotoxin-producing Escherichia coli O103:H2 isolates from cattle and humans. J Clin Microbiol 2008; 46:3569-75. [PMID: 18768648 DOI: 10.1128/jcm.01095-08] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Characterization of important non-O157 verotoxin-producing Escherichia coli (VTEC) has lagged considerably behind that of O157:H7 strains. This study characterized 91 VTEC O103:H2 strains from bovine and human sources and of North American and European origins by virulence or putative virulence genes, pulsed-field gel electrophoresis (PFGE) patterns, plasmid profiles, antimicrobial resistance, and colicin production. All strains were positive for vt1 and eae-epsilon; 97% were positive for ehxA; and all were negative for hlyA. Two strains carried vt2. There were 66 PFGE patterns grouped in six clusters, and there were 25 different plasmid profiles. Plasmid-encoded katP and etp genes were significantly more frequent in European than in North American human strains. The distribution of selected phenotypes was as follows: enterohemorrhagic E. coli (EHEC) hemolysin, 95%; colicin production, 38%; antimicrobial resistance, 58%. All the strains were negative for the alpha-hemolytic phenotype. In conclusion, the VTEC O103:H2 strains were diverse, as shown by PFGE, plasmid profiles, virulence markers, and antimicrobial resistance patterns, and all strains showed an EHEC hemolytic phenotype instead of the alpha-hemolytic phenotype that has been shown previously.
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Evaluation of major types of Shiga toxin 2E-producing Escherichia coli bacteria present in food, pigs, and the environment as potential pathogens for humans. Appl Environ Microbiol 2008; 74:4806-16. [PMID: 18515483 DOI: 10.1128/aem.00623-08] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Shiga toxin 2e (Stx2e)-producing strains from food (n = 36), slaughtered pigs (n = 25), the environment (n = 21), diseased pigs (n = 19), and humans (n = 9) were investigated for production of Stx2e by enzyme-linked immunosorbent assay, for virulence markers by PCR, and for their serotypes to evaluate their role as potential human pathogens. Stx2e production was low in 64% of all 110 strains. Stx2e production was inducible by mitomycin C but differed considerably between strains. Analysis by nucleotide sequencing and transcription of stx(2e) genes in high- and low-Stx2e-producing strains showed that toxin production correlated with transcription rates of stx(2e) genes. DNA sequences specific for the int, Q, dam, and S genes of the stx(2e) bacteriophage P27 were found in 109 strains, indicating cryptic P27-like prophages, although 102 of these were not complete for all genes tested. Genes encoding intimin (eae), enterohemorrhagic Escherichia coli hemolysin (ehx), or other stx(1) or stx(2) variants were not found, whereas genes for heat-stable enterotoxins STI, STII, or EAST1 were present in 54.5% of the strains. Seven major serotypes that were associated with diseased pigs (O138:H14, O139:H1, and O141:H4) or with slaughter pigs, food, and the environment (O8:H4, O8:H9, O100:H30, and O101:H9) accounted for 60% of all Stx2e strains. The human Stx2e isolates did not belong to these major serotypes of Stx2e strains, and high production of Stx2e in human strains was not related to diarrheal disease. The results from this study and other studies do not point to Stx2e as a pathogenicity factor for diarrhea and hemolytic uremic syndrome in humans.
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Phylogenetic backgrounds and virulence profiles of atypical enteropathogenic Escherichia coli strains from a case-control study using multilocus sequence typing and DNA microarray analysis. J Clin Microbiol 2008; 46:2280-90. [PMID: 18463209 DOI: 10.1128/jcm.01752-07] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Atypical enteropathogenetic Escherichia coli (EPEC) strains are frequently detected in children with diarrhea but are also a common finding in healthy children. The aim of this study was to compare the phylogenetic ancestry and virulence characteristics of atypical (eae positive, stx and bfpA negative) EPEC strains from Norwegian children with (n = 37) or without (n = 19) diarrhea and to search for an association between phylogenetic ancestry and diarrhea. The strains were classified in phylogenetic groups by phylogenetic marker genes and in sequence types (STs) by multilocus sequence typing. Phylogenetic ancestry was compared to virulence characteristics based on DNA microarray analysis. Serotyping and pulsed-field gel electrophoresis (PFGE) were also performed. All four phylogenetic groups, 26 different STs, and 20 different clonal groups were represented among the 56 atypical EPEC strains. The strains were separated into three clusters by overall virulence gene profile; one large cluster with A, B1, and D strains and two clusters with group B2 strains. There was considerable heterogeneity in the PFGE profiles and serotypes, and almost half of the strains were O nontypeable. The efa1/lifA gene, previously shown to be statistically linked with diarrhea in this strain collection (J. E. Afset et al., J. Clin. Microbiol. 44:3703-3711, 2006), was present in 8 of 26 STs. The two phylogenetic groups B1 and D were weakly associated with diarrhea (P = 0.06 and P = 0.09, respectively). In contrast, group B2 was isolated most frequently from healthy controls (P = 0.05). In conclusion, the atypical EPEC strains were heterogeneous both phylogenetically and by virulence profile. Phylogenetic ancestry was less useful as a predictor of diarrhea than were specific virulence genes.
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Schimmer B, Nygard K, Eriksen HM, Lassen J, Lindstedt BA, Brandal LT, Kapperud G, Aavitsland P. Outbreak of haemolytic uraemic syndrome in Norway caused by stx2-positive Escherichia coli O103:H25 traced to cured mutton sausages. BMC Infect Dis 2008; 8:41. [PMID: 18387178 PMCID: PMC2335110 DOI: 10.1186/1471-2334-8-41] [Citation(s) in RCA: 123] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2007] [Accepted: 04/03/2008] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND On 20-21 February 2006, six cases of diarrhoea-associated haemolytic uraemic syndrome (HUS) were reported by paediatricians to the Norwegian Institute of Public Health. We initiated an investigation to identify the etiologic agent and determine the source of the outbreak in order to implement control measures. METHODS A case was defined as a child with diarrhoea-associated HUS or any person with an infection with the outbreak strain of E. coli O103 (defined by the multi-locus variable number tandem repeats analysis (MLVA) profile) both with illness onset after January 1st 2006 in Norway. After initial hypotheses-generating interviews, we performed a case-control study with the first fifteen cases and three controls for each case matched by age, sex and municipality. Suspected food items were sampled, and any E. coli O103 strains were typed by MLVA. RESULTS Between 20 February and 6 April 2006, 17 cases were identified, of which 10 children developed HUS, including one fatal case. After pilot interviews, a matched case-control study was performed indicating an association between a traditional cured sausage (odds ratio 19.4 (95% CI: 2.4-156)) and STEC infection. E. coli O103:H25 identical to the outbreak strain defined by MLVA profile was found in the product and traced back to contaminated mutton. CONCLUSION We report an outbreak caused by a rare STEC variant (O103:H25, stx2-positive). More than half of the diagnosed patients developed HUS, indicating that the causative organism is particularly virulent. Small ruminants continue to be important reservoirs for human-pathogen STEC. Improved slaughtering hygiene and good manufacturing practices for cured sausage products are needed to minimise the possibility of STEC surviving through the entire sausage production process.
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Affiliation(s)
- Barbara Schimmer
- Department of Infectious Disease Epidemiology, Norwegian Institute of Public Health, Oslo, Norway.
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Wani SA, Hussain I, Nabi A, Fayaz I, Nishikawa Y. Variants of eae and stx genes of atypical enteropathogenic Escherichia coli and non-O157 Shiga toxin-producing Escherichia coli from calves. Lett Appl Microbiol 2007; 45:610-5. [PMID: 17916128 DOI: 10.1111/j.1472-765x.2007.02235.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIMS To determine the subtypes of stx and eae genes of Shiga toxin-producing Escherichia coli (STEC) and enteropathogenic Escherichia coli (EPEC) from calves and to ascertain the typical and atypical nature of EPEC. METHODS AND RESULTS One hundred and eighty-seven faecal samples from 134 diarrhoeic and 53 healthy calves were investigated for the presence of stx, eae and ehxA virulence genes by polymerase chain reaction and enzyme-linked immunosorbent assay. Subtype analysis of stx(1) exhibited stx(1c) in 13 (31.70%) isolates, while that of stx(2) revealed stx(2c) in eight (24.24%) and stx(2d) in two (6.06%) isolates. Subtyping of eae gene showed the presence of eae-beta, eae-eta and eae-zeta in two, three and four isolates respectively. None of the E. coli isolates possessed stx(2e), stx(2f), eae-alpha, eae-delta, eae-epsilon and eae-xi. All EPEC isolates were atypical. CONCLUSIONS stx(1), stx(1c), stx(2), stx(2c), stx(2d), eae-beta, eae-eta and eae-zeta subtypes are prevalent in STEC and EPEC isolates in India. SIGNIFICANCE AND IMPACT OF THE STUDY This is the first subtype analysis of stx(2) and eae genes of animal E. coli isolates in India and emphasizes the need to investigate their transmission to humans.
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Affiliation(s)
- S A Wani
- Bacteriology Laboratory, Division of Veterinary Microbiology and Immunology, SK University of Agricultural Sciences and Technology of Kashmir, Shuhama (Alusteng), Srinagar, India.
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Kijima-Tanaka M, Kawanishi M, Fukuda Y, Suzuki S, Yagyu K. Molecular diversity of Photobacterium damselae ssp. piscicida from cultured amberjacks (Seriola spp.) in Japan by pulsed-field gel electrophoresis and plasmid profiles. J Appl Microbiol 2007; 103:381-9. [PMID: 17650198 DOI: 10.1111/j.1365-2672.2006.03257.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
AIMS This study deals with a pulsed-field gel electrophoresis (PFGE) for discriminating between the genetic variants of Photobacterium damselae ssp. piscicida, and characterizing of Japanese field isolates by PFGE together with plasmid profiles and antimicrobial resistances. METHODS AND RESULTS A total of 74 field isolates from cultured Japanese amberjacks were used for PFGE. SmaI and NotI enabled to clearly differentiate strains and we obtained 24 of combined PFGE profiles which were distinct from those of classical Japanese and USA reference strains, and classified them into three groups (Ia-Ic). By plasmid size, we could classify these field isolates into three plasmid types, pA-pC. The predominant PFGE-type Ia was closely associated with plasmid-type pA, and Ib showed a moderate association with pB. Ic was closely associated with pC, and multiresistant isolates were not observed in this type. Whole-genomic variations were also observed between isolates having identical detection areas, fish species and detection-date by PFGE. CONCLUSION Molecular diversity of P. damselae ssp. piscicida could be detected by PFGE, and some relations among the PFGE-type, plasmid-type and antimicrobial resistances were observed in Japanese field isolates. SIGNIFICANCE AND IMPACT OF THE STUDY This study indicated that some genetic transition might have occurred in P. damselae ssp. piscicida around the Japanese seas, and PFGE can be a valuable tool for the epidemiological study of this highly homogeneous subspecies.
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Affiliation(s)
- M Kijima-Tanaka
- National Veterinary Assay Laboratory, Ministry of Agriculture, Forestry and Fisheries, Tokyo, Japan.
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Bettelheim KA. The non-O157 shiga-toxigenic (verocytotoxigenic) Escherichia coli; under-rated pathogens. Crit Rev Microbiol 2007; 33:67-87. [PMID: 17453930 DOI: 10.1080/10408410601172172] [Citation(s) in RCA: 197] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Following a brief review of the ecology of Escherichia coli in general, the role of Shiga-Toxigenic (Verocytotoxigenic) E. coli (STEC) as pathogens is addressed. While STEC belonging to the serogroup O157 have been extensively studied and shown to be involved in many cases and outbreaks of human disease, the importance of STEC belonging to other serogroups has not been recognized as much. This review addresses the problems associated with these pathogens, demonstrating that increasing the awareness of them is a major part of the problem. This review then demonstrates how widespread isolations especially from food animals and human disease have been, discussing in particular STEC belonging to serogroups O8, O26, O103, O111, O113 and O128. The animal host-specificity of these STEC is also reviewed. In conclusion some methods of improving isolation of these pathogens is addressed.
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Gilmour MW, Olson AB, Andrysiak AK, Ng LK, Chui L. Sequence-based typing of genetic targets encoded outside of the O-antigen gene cluster is indicative of Shiga toxin-producing Escherichia coli serogroup lineages. J Med Microbiol 2007; 56:620-628. [PMID: 17446284 PMCID: PMC2884935 DOI: 10.1099/jmm.0.47053-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Serogroup classifications based upon the O-somatic antigen of Shiga toxin-producing Escherichia coli (STEC) provide significant epidemiological information on clinical isolates. Each O-antigen determinant is encoded by a unique cluster of genes present between the gnd and galF chromosomal genes. Alternatively, serogroup-specific polymorphisms might be encoded in loci that are encoded outside of the O-antigen gene cluster. Segments of the core bacterial loci mdh, gnd, gcl, ppk, metA, ftsZ, relA and metG for 30 O26 STEC strains have previously been sequenced, and comparative analyses to O157 distinguished these two serogroups. To screen these loci for serogroup-specific traits within a broader range of clinically significant serogroups, DNA sequences were obtained for 19 strains of 10 additional STEC serogroups. Unique alleles were observed at the gnd locus for each examined STEC serogroup, and this correlation persisted when comparative analyses were extended to 144 gnd sequences from 26 O-serogroups (comprising 42 O : H-serotypes). These included O157, O121, O103, O26, O5 : non-motile (NM), O145 : NM, O113 : H21, O111 : NM and O117 : H7 STEC; and furthermore, non-toxin encoding O157, O26, O55, O6 and O117 strains encoded distinct gnd alleles compared to STEC strains of the same serogroup. DNA sequencing of a 643 bp region of gnd was, therefore, sufficient to minimally determine the O-antigen of STEC through molecular means, and the location of gnd next to the O-antigen gene cluster offered additional support for the co-inheritance of these determinants. The gnd DNA sequence-based serogrouping method could improve the typing capabilities for STEC in clinical laboratories, and was used successfully to characterize O121 : H19, O26 : H11 and O177 : NM clinical isolates prior to serological confirmation during outbreak investigations.
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Affiliation(s)
- Matthew W. Gilmour
- National Microbiology Laboratory, Public Health Agency of Canada, 1015 Arlington Street, Winnipeg, Manitoba R3E 3R2, Canada
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Adam B. Olson
- National Microbiology Laboratory, Public Health Agency of Canada, 1015 Arlington Street, Winnipeg, Manitoba R3E 3R2, Canada
| | - Ashleigh K. Andrysiak
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Lai-King Ng
- National Microbiology Laboratory, Public Health Agency of Canada, 1015 Arlington Street, Winnipeg, Manitoba R3E 3R2, Canada
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Linda Chui
- Alberta Provincial Laboratory for Public Health, Edmonton, Alberta, Canada
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Creuzburg K, Schmidt H. Molecular characterization and distribution of genes encoding members of the type III effector nleA family among pathogenic Escherichia coli strains. J Clin Microbiol 2007; 45:2498-507. [PMID: 17553972 PMCID: PMC1951211 DOI: 10.1128/jcm.00038-07] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In this study, we investigated the occurrence of the previously described gene nleA(4795) and variants of nleA, putatively encoding non-locus-of-enterocyte-effacement-encoded type III effector proteins with functions that are unknown. nleA variants were detected in 150 out of 170 enteropathogenic Escherichia coli strains and enterohemorrhagic E. coli strains, two of them being eae negative. Besides the known variants nleA(4795), Z6024, and the espI-like gene, 11 novel nleA variants with different lengths and sequence identities at the deduced amino acid level (between 71% and 96%) have been identified. Whereas most of the serogroups associated with more severe disease were quite homogenous with respect to the presence of a particular nleA variant, other serogroups were not. Moreover, Southern blot hybridization revealed that certain strains carry two copies of nleA in their chromosome, frequently encoding different variants. In most cases, the open reading frame of one of the copies was disrupted, usually by an insertion element. Furthermore, transmission of the type III effector-encoding gene could be shown by transduction of nleA-carrying bacteriophages to a laboratory E. coli strain.
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Affiliation(s)
- Kristina Creuzburg
- Institute of Food Science and Biotechnology, Department of Food Microbiology, University of Hohenheim, 70599 Stuttgart, Germany
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Jandu N, Shen S, Wickham ME, Prajapati R, Finlay BB, Karmali MA, Sherman PM. Multiple seropathotypes of verotoxin-producing Escherichia coli (VTEC) disrupt interferon-γ-induced tyrosine phosphorylation of signal transducer and activator of transcription (Stat)-1. Microb Pathog 2007; 42:62-71. [PMID: 17174521 DOI: 10.1016/j.micpath.2006.10.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2006] [Revised: 10/30/2006] [Accepted: 10/30/2006] [Indexed: 12/22/2022]
Abstract
Verotoxin-producing Escherichia coli (VTEC) O157:H7 inhibits interferon-gamma-stimulated tyrosine phosphorylation of signal transducer and activator of transcription (Stat)-1 in epithelial cells, independent of Verotoxins and the locus of enterocyte effacement pathogenicity island. Although E. coli O157:H7 is the major cause of disease in humans, non-O157:H7 VTEC also cause human disease. However, the virulence properties of non-O157:H7 VTEC are less well characterized. The aims of this study were to define the ability of VTEC strains of differing seropathotypes (classified as A-E) to inhibit interferon-gamma stimulated Stat1-phosphorylation and to further characterize the bacterial-derived inhibitory factor. Confluent T84 and HEp-2 cells were infected with VTEC strains (MOI 100:1, 6h, 37 degrees C), and then stimulated with interferon-gamma (50 ng/mL) for 0.5h at 37 degrees C. Whole-cell protein extracts of infected cells were collected and prepared for immunoblotting to detect tyrosine phosphorylation of Stat1. The effects of E. coli O55 strains, the evolutionary precursors of VTEC, on Stat1-tyrosine phosphorylation were also determined. The effects of isogenic mutants of O-islands 47 and 122 were tested to determine the role of genes encoded on these putative pathogenicity islands in mediating VTEC inhibition of the interferon-gamma-Stat1 signaling cascade. To evaluate potential mechanism(s) of inhibition, VTEC O157:H7-infected cells were treated with pharmacological inhibitors, including, wortmannin and LY294002. Relative to uninfected cells, Stat1-tyrosine phosphorylation was significantly reduced after 6h infection of both T84 and HEp-2 cells by VTEC strains of all five seropathotypes. E. coli O55 strains, but not enteropathogenic E. coli (EPEC), also caused inhibition of Stat1-tyrosine phosphorylation, suggesting that this effect was acquired early in the evolution of VTEC. Stat1-activation did not recover in epithelial cells infected with isogenic mutants of O-islands 47 and 122, indicating that the inhibitory factor was not contained in these genomic regions. Stat1-phosphorylation remained intact when VTEC-infected cells were treated with wortmannin (0-100 nM), but not by treatment with the more specific PI3-kinase inhibitor, LY294002. Inhibition of interferon-gamma stimulated Stat1-tyrosine phosphorylation by VTEC of multiple seropathotypes indicates the presence of a common inhibitory factor that is independent of bacterial virulence in humans. The results of treatment with wortmannin suggest that the bacterial-derived inhibitory factor employs host cell signal transduction to mediate inhibition of Stat1-activation.
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Affiliation(s)
- Narveen Jandu
- Research Institute, Hospital for Sick Children, Ont., Canada
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