scholarly journals Distribution of novel Og-types in Shiga toxin-producing Escherichia coli isolated from healthy cattle

2020 ◽  
pp. JCM.02624-20
Author(s):  
Nguyen Thi Thu Huong ◽  
Atsushi Iguchi ◽  
Ritsuko Ohata ◽  
Hisahiro Kawai ◽  
Tadasuke Ooka ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Foodborne Pathogen ◽  
Genomic Analysis ◽  
Epidemiological Studies ◽  
Biosynthesis Gene Cluster ◽  
E Coli ◽  
Shigella Boydii ◽  
Healthy Cattle ◽  
Type Strains

Shiga toxin-producing Escherichia coli (STEC) is an important foodborne pathogen. Although most cases of STEC infection in humans are due to O157 and non-O157 serogroups, there are also reports of infection with STEC strains that cannot be serologically classified into any O-serogroup (O-serogroup untypeable, OUT). Recently, it has become clear that even OUT strains can be subclassified based on the diversity of O-antigen biosynthesis gene cluster (O-AGC) sequences. Cattle are thought to be a major reservoir of STEC strains belonging to various serotypes; however, the internal composition of OUT STEC strains in cattle remains unknown. In this study, we screened 366 STEC strains isolated from healthy cattle by using multiplex PCR kits including primers that targeted novel O-AGC types (Og-types) found in OUT E. coli and Shigella strains in previous studies. Interestingly, 94 (25.7%) of these strains could be classified into 13 novel Og-types. Genomic analysis revealed that the results of the in silico serotyping of novel Og-type strains were perfectly consistent with those of the PCR experiment. In addition, it was revealed that a dual Og8+OgSB17-type strain carried two types of O-AGCs from E. coli O8 and Shigella boydii type 17 tandemly inserted at the locus, with both antigens expressed on the cell surface. The results of this comprehensive analysis of cattle-derived STEC strains may help improve our understanding of the strains circulating in the environment. Additionally, the DNA-based serotyping systems used in this study could be used in future epidemiological studies and risk assessments of other STEC strains.

scholarly journals Emergence of a Multidrug-Resistant Shiga Toxin-Producing Enterotoxigenic Escherichia coli Lineage in Diseased Swine in Japan

2016 ◽  
Vol 54 (4) ◽  
pp. 1074-1081 ◽  
Author(s):  
Masahiro Kusumoto ◽  
Yuna Hikoda ◽  
Yuki Fujii ◽  
Misato Murata ◽  
Hirotsugu Miyoshi ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Significant Risk ◽  
Multidrug Resistant ◽  
Limited Range ◽  
Enterotoxigenic Escherichia Coli ◽  
Content Type ◽  
E Coli ◽  
Shigella Boydii ◽  
High Level

EnterotoxigenicEscherichia coli(ETEC) and Shiga toxin-producingE. coli(STEC) are important causes of diarrhea and edema disease in swine. The majority of swine-pathogenicE. colistrains belong to a limited range of O serogroups, including O8, O138, O139, O141, O147, O149, and O157, which are the most frequently reported strains worldwide. However, the circumstances of ETEC and STEC infections in Japan remain unknown; there have been few reports on the prevalence or characterization of swine-pathogenicE. coli. In the present study, we determined the O serogroups of 967E. coliisolates collected between 1991 and 2014 from diseased swine in Japan, and we found that O139, O149, O116, and OSB9 (O serogroup ofShigella boydiitype 9) were the predominant serogroups. We further analyzed these four O serogroups using pulsed-field gel electrophoresis (PFGE), multilocus sequence typing, and virulence factor profiling. Most of the O139 and O149 strains formed serogroup-specific PFGE clusters (clusters I and II, respectively), whereas the O116 and OSB9 strains were grouped together in the same cluster (cluster III). All of the cluster III strains belonged to a single sequence type (ST88) and carried genes encoding both enterotoxin and Shiga toxin. This PFGE cluster III/ST88 lineage exhibited a high level of multidrug resistance (to a median of 10 antimicrobials). Notably, these bacteria were resistant to fluoroquinolones. Thus, this lineage should be considered a significant risk to animal production due to the toxigenicity and antimicrobial resistance of these bacteria.

scholarly journals Improved Genomic Identification, Clustering, and Serotyping of Shiga Toxin-Producing Escherichia coli Using Cluster/Serotype-Specific Gene Markers

2022 ◽  
Vol 11 ◽  
Author(s):  
Xiaomei Zhang ◽  
Michael Payne ◽  
Sandeep Kaur ◽  
Ruiting Lan
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
In Silico ◽  
Genomic Analysis ◽  
Comparative Genomic ◽  
Specific Gene ◽  
Metagenomic Sequencing ◽  
Accurate Identification ◽  
Gene Markers ◽  
E Coli

Shiga toxin-producing Escherichia coli (STEC) have more than 470 serotypes. The well-known STEC O157:H7 serotype is a leading cause of STEC infections in humans. However, the incidence of non-O157:H7 STEC serotypes associated with foodborne outbreaks and human infections has increased in recent years. Current detection and serotyping assays are focusing on O157 and top six (“Big six”) non-O157 STEC serogroups. In this study, we performed phylogenetic analysis of nearly 41,000 publicly available STEC genomes representing 460 different STEC serotypes and identified 19 major and 229 minor STEC clusters. STEC cluster-specific gene markers were then identified through comparative genomic analysis. We further identified serotype-specific gene markers for the top 10 most frequent non-O157:H7 STEC serotypes. The cluster or serotype specific gene markers had 99.54% accuracy and more than 97.25% specificity when tested using 38,534 STEC and 14,216 non-STEC E. coli genomes, respectively. In addition, we developed a freely available in silico serotyping pipeline named STECFinder that combined these robust gene markers with established E. coli serotype specific O and H antigen genes and stx genes for accurate identification, cluster determination and serotyping of STEC. STECFinder can assign 99.85% and 99.83% of 38,534 STEC isolates to STEC clusters using assembled genomes and Illumina reads respectively and can simultaneously predict stx subtypes and STEC serotypes. Using shotgun metagenomic sequencing reads of STEC spiked food samples from a published study, we demonstrated that STECFinder can detect the spiked STEC serotypes, accurately. The cluster/serotype-specific gene markers could also be adapted for culture independent typing, facilitating rapid STEC typing. STECFinder is available as an installable package (https://github.com/LanLab/STECFinder) and will be useful for in silico STEC cluster identification and serotyping using genome data.

scholarly journals Molecular Identification of Virulence Genes of Escherichia coli Isolated from Cow Milk and Its Products in Abuja, Nigeria

2020 ◽  
pp. 11-18
Author(s):  
E. C. Okechukwu ◽  
E. U. Amuta ◽  
G. M. Gberikon ◽  
N. Chima ◽  
B. Yakubu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Virulence Genes ◽  
Foodborne Pathogen ◽  
Cow Milk ◽  
E Coli ◽  
Milk Samples ◽  
The Family ◽  
High Prevalence ◽  
Polymerase Chain

Shiga toxin-producing Escherichia coli have been identified as an emerging foodborne pathogen which portends serious risk to human health. Cow milk and its products are potential sources of shiga toxin-producing Escherichia coli. A relatively small number from the family of shiga toxin-producing Escherichia coli are pathogenic. It becomes necessary that Cow milk and milk products are regularly screened for the presence of virulence genes in microbes. The study aimed to genetically determine the presence of virulence genes that are characteristic of Enterohaemorrhagic E. coli in 600 milk samples. The E. coli isolates were recovered from the milk samples (n=35), biochemically examined and genetically screened for virulence genes by multiplex Polymerase Chain Reaction (PCR). The results of the molecular profiling revealed that (stx2) was detected in 17(60.7%), (hlyA) 11(39.3%) and eae genes 8(28.6%) of the E. coli isolates respectively, while (stx1) was not detected. The results indicated a high prevalence of virulent shiga toxin-producing Escherichia coli in the milk samples. Priority attention should be given to this microbe as it will demand stringent steps in the detection given that they are known to be rigorous in identification.

scholarly journals Prevalence, Virulence Genes and Antimicrobial Profiles of Escherichia Coli O157:H7 Isolated from Healthy Cattle

2021 ◽  
Author(s):  
Ghassan Tayh ◽  
Salma Mariem Boubaker ◽  
Rym Ben Khedher ◽  
Mounir Jbeli ◽  
Faten Ben Chehida ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Latex Agglutination ◽  
Human Consumption ◽  
Toxin Gene ◽  
Fecal Samples ◽  
E Coli ◽  
Food Borne ◽  
Healthy Cattle ◽  
Amoxicillin Clavulanic Acid

Abstract Background: Shiga toxin-producing Escherichia coli (STEC) O157:H7 is associated with intestinal infection in human and considered a main cause of food-borne diseases. It was isolated from animals, human and food. The aim of the study was to assess the incidence of E. coli O157:H7 in fecal samples of healthy cattle collected in slaughterhouses (n=160) and from farms (n=100).Methods: E. coli isolates were detected on MacConkey agar. A total of 236 E. coli isolates were recovered from fecal samples of healthy cattle. We used sorbitol MacConkey to detect non-sorbitol fermenting colonies that were examined for the presence of O157 antigen by latex agglutination, and positive bacteria were screened for the existence of stx1, stx2, eaeA and ehxA by PCR as well as rfbEO157 and fliCH7 genes specific for serotype O157. All isolates were examined for the susceptibility against 21antibiotics discs.Results: Of the 236 E. coli isolates, 4.2% (10/236) were positive for STEC O157:H7. Shiga toxin gene (stx2) was present in 70% of isolates, stx1 and ehxA were confirmed in 60% of the isolates, whereas eae was identified in two isolates. Other virulence factors screened (fimH, sfa/focDE, cdt3, traT, iutA and hly) were present among the 10 isolates. All E. coli O157:H7 isolates were sensitive to amoxicillin/clavulanic acid, cefotaxime, cefepime, aztreonam, colistin and sulfamethoxazole/trimethoprim. All isolates belong to the phylo-group E.Conclusion: This is the first study of the incidence of E. coli O157:H7 in cattle in Tunisia. Our finding proves the existence of STEC O157:H7 in healthy animals producing food for human consumption which could be a source of human contamination.

scholarly journals Escherichia coli Serogroup O107/O117 Lipopolysaccharide Binds and Neutralizes Shiga Toxin 2

2004 ◽  
Vol 186 (16) ◽  
pp. 5506-5512 ◽  
Author(s):  
Shantini D. Gamage ◽  
Colleen M. McGannon ◽  
Alison A. Weiss
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Biochemical Characterization ◽  
Vero Cells ◽  
Systemic Complications ◽  
E Coli ◽  
Major Virulence Factor ◽  
Shiga Toxin 2 ◽  
Type Strains

ABSTRACT The AB5 toxin Shiga toxin 2 (Stx2) has been implicated as a major virulence factor of Escherichia coli O157:H7 and other Shiga toxin-producing E. coli strains in the progression of intestinal disease to more severe systemic complications. Here, we demonstrate that supernatant from a normal E. coli isolate, FI-29, neutralizes the effect of Stx2, but not the related Stx1, on Vero cells. Biochemical characterization of the neutralizing activity identified the lipopolysaccharide (LPS) of FI-29, a serogroup O107/O117 strain, as the toxin-neutralizing component. LPSs from FI-29 as well as from type strains E. coli O107 and E. coli O117 were able bind Stx2 but not Stx1, indicating that the mechanism of toxin neutralization may involve inhibition of the interaction between Stx2 and the Gb3 receptor on Vero cells.

scholarly journals Escherichia coli O-Genotyping PCR: a Comprehensive and Practical Platform for Molecular O Serogrouping

2015 ◽  
Vol 53 (8) ◽  
pp. 2427-2432 ◽  
Author(s):  
Atsushi Iguchi ◽  
Sunao Iyoda ◽  
Kazuko Seto ◽  
Tomoko Morita-Ishihara ◽  
Flemming Scheutz ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Low Cost ◽  
Epidemiological Studies ◽  
Biosynthesis Gene Cluster ◽  
Content Type ◽  
E Coli ◽  
O Antigen ◽  
Promising Tool ◽  
Outbreak Investigations ◽  
Wild Strains

The O serogrouping of pathogenicEscherichia coliis a standard method for subtyping strains for epidemiological studies and enhancing phylogenetic studies. In particular, the identification of strains of the same O serogroup is essential in outbreak investigations and surveillance. In a previous study, we analyzed the O-antigen biosynthesis gene cluster in all knownE. coliO serogroups (A. Iguchi et al., DNA Res, 22:101–107, 2015,http://dx.doi.org/10.1093/dnares/dsu043). Based on those results, we have arranged 162 PCR primer pairs for the identification or classification of O serogroups. Of these, 147 pairs were used to identify 147 individual O serogroups with unique O-antigen biosynthesis genes, and the other 15 pairs were used to identify 15 groups of strains (Gp1 to Gp15). Each of these groups consisted of strains with identical or very similar O-antigen biosynthesis genes, and the groups represented a total of 35 individual O serogroups. We then used the 162 primer pairs to create 20 multiplex PCR sets. Each set contained six to nine primer pairs that amplify products of markedly different sizes. This genetic methodology (E. coliO-genotyping PCR) allowed for comprehensive, rapid, and low-cost typing. Validation of the PCR system using O-serogroup references and wild strains showed that the correct O serogroups were specifically and accurately identified for 100% (182/182) and 90.8% (522/575) of references and wild strains, respectively. The PCR-based system reported here might be a promising tool for the subtyping ofE. colistrains for epidemiological studies as well as for the surveillance of pathogenicE. coliduring outbreaks.

scholarly journals Antimicrobial resistance in Shiga toxin-producing Escherichia coli other than serotype O157 : H7 in England, 2014–2016

2020 ◽  
Vol 69 (3) ◽  
pp. 379-386 ◽  
Author(s):  
Amy Gentle ◽  
Martin R. Day ◽  
Katie L. Hopkins ◽  
Gauri Godbole ◽  
Claire Jenkins
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Resistance Genes ◽  
Shiga Toxin ◽  
Type Species ◽  
Gastrointestinal Disease ◽  
Foodborne Pathogen ◽  
Content Type ◽  
E Coli ◽  
Link Type

Introduction. Despite many ongoing surveillance projects and the recent focus on the veterinary and clinical ‘One Health’ aspects of antimicrobial resistance (AMR), evidence of the extent of any public health risk posed by animal reservoirs with respect to the transmission of resistant strains of Escherichia coli to humans remains varied and contentious. In the UK, the main zoonotic reservoir for the foodborne pathogen Shiga toxin-producing E. coli (STEC) is cattle and sheep. In this study, we adopt an alternative approach to the risk assessment of transmission of AMR E. coli from animals to humans, involving monitoring AMR in isolates of STEC, an established zoonotic, foodborne pathogen, from human cases of gastrointestinal disease. Aim. The aim of this study was to determine the genome-derived AMR profiles for STEC from human cases to assess the risk of transmission of multidrug-resistant STEC from ruminants to humans. Methodology. STEC belonging to 10 different clonal complexes (CCs) (n=457) isolated from human faecal specimens were sequenced and genome-derived AMR profiles were determined. Phenotypic susceptibility testing was undertaken on all isolates (n=100) predicted to be resistant to at least one class of antimicrobial. Results. Of the 457 isolates, 332 (72.7 %) lacked identifiable resistance genes and were predicted to be fully susceptible to 11 classes of antimicrobials; 125/332 (27.3 %) carried 1 or more resistance genes, of which 83/125 (66.4 %) were resistant to 3 or more classes of antibiotic. The percentage of isolates harbouring AMR determinants varied between CCs, from 4% in CC25 to 100% in CC504. Forty-six different AMR genes were detected, which conferred resistance to eight different antibiotic classes. Resistance to ampicillin, streptomycin, tetracyclines and sulphonamides was most commonly detected. Four isolates were identified as extended-spectrum β-lactamase producers. An overall concordance of 97.7 % (n=1075/1100) was demonstrated between the phenotypic and genotypic methods. Conclusion. This analysis provided an indirect assessment of the risk of transmission of AMR gastrointestinal pathogens from animals to humans, and revealed a subset of human isolates of the zoonotic pathogen STEC were resistant to the antimicrobials used in animal husbandry. However, this proportion has not increased over the last three decades, and thismay provide evidence that guidancepromoting responsible practice has been effective.

scholarly journals Prevalence of Shiga toxin-producing and Enteropathogenic Escherichia coli Isolated from Chicken Meat in the west of Iran

2019 ◽  
Author(s):  
omid zarei ◽  
Leili Shokoohizadeh ◽  
Hadi Hossainpour ◽  
Mohammad Yousef Alikhani
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Genetic Relatedness ◽  
Culture Media ◽  
Foodborne Pathogen ◽  
Chicken Meat ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
E Coli ◽  
High Level

Abstract Objective: Shiga toxin-producing Escherichia coli (STEC) is known as a crucial zoonotic foodborne pathogen. Totally, 257 raw chicken meat were collected from markets in Hamadan, west of Iran. The samples were cultured on selective culture media and the virulence genes of E. coli isolates were analyzed by PCR. The antibiotic resistance patterns were determined by the disk diffusion method. The genetic relatedness of the E. coli O157 isolates was analyzed by ERIC-PCR. Results: Totally, 93 (36%; 95% CI 41.9- 30.1%) isolates were identified as E. coli. Based on microbiological tests, 36 (38.7%; 95% CI 48.6-28.8), 7 (7.5%; 95% CI 12.8-2.2%), and 12 (12.9%; 95% CI 19.7- 6.1%) of the E. coli isolates were characterized as STEC, Enteropathogenic E. coli, and attaching and effacing E. coli (AEEC) strains, respectively. A high level of resistance to nalidixic acid (91.4%; 95% CI 97.1- 85.7%), tetracycline (89.8%; 95% CI 96.2-83.5%), ampicillin (82.8%; 95% CI 90.2-75.1%), and sulfametoxazole-trimotoprime (71%; 95% CI 80.2-61.8%) was detected among the E. coli isolates. The analysis of ERIC-PCR results showed five different ERIC types among the E. coli O157 isolates. Based on findings, control and check-up of poultry meats should be considered as a crucial issue for public health.

scholarly journals Prevalence and Characteristics of Shiga Toxin-Producing Escherichia coli from Healthy Cattle in Japan

2001 ◽  
Vol 67 (1) ◽  
pp. 484-489 ◽  
Author(s):  
Hideki Kobayashi ◽  
Jun Shimada ◽  
Muneo Nakazawa ◽  
Tetsuo Morozumi ◽  
Tarja Pohjanvirta ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Virulence Factor ◽  
Shiga Toxin ◽  
Animal Groups ◽  
E Coli ◽  
Healthy Cattle ◽  
Stool Samples ◽  
Enterocyte Effacement ◽  
Virulence Factor Genes

ABSTRACT The prevalence of Shiga toxin-producing Escherichia coli (STEC) in Japan was examined by using stool samples from 87 calves, 88 heifers, and 183 cows on 78 farms. As determined by screening with stx-PCR, the prevalence was 46% in calves, 66% in heifers, and 69% in cows; as determined by nestedstx-PCR, the prevalence was 100% in all animal groups. Of the 962 isolates picked by colony stx hybridization, 92 isolates from 54 farms were characterized to determine their O serogroups, virulence factor genes, and antimicrobial resistance. Of these 92 isolates, 74 (80%) could be classified into O serogroups; 50% of these 74 isolates belonged to O serogroups O8, O26, O84, O113, and O116 and 1 isolate belonged to O serogroup O157. Locus of enterocyte effacement genes were detected in 24% of the isolates, and enterohemorrhagic E. coli (EHEC) hlyA genes were detected in 72% of the isolates. Neither the bundle-forming pilus gene nor the enteropathogenic E. coli adherence factor plasmid was found. STEC strains with characteristics typical of isolates from human EHEC infections, which were regarded as potential EHEC strains, were present on 11.5% of the farms.

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