Prevalence, virulence potential, and pulsed-field gel electrophoresis profiling of Shiga toxin-producing Escherichia coli strains from cattle

Abstract

BackgroundAs a primary source of Shiga-toxin-producing Escherichia coli (STEC) infection, cattle are often targeted to develop strategies for reducing STEC contamination. Monitoring the virulence potentials of STEC isolates from cattle is important for tracing contamination sources, managing outbreaks or sporadic cases, and reducing the risks for human infection. This study aimed to investigate the prevalence of STEC in cattle farm samples in South Korea and to assess their virulence potentials.ResultsIn total, 63 STEC were isolated from 496 cattle farm samples, and temperature and rainfall affected STEC prevalence (p < 0.001). The O157 serogroup was most prevalent, followed by O108, O8, O84, O15, and O119. In the stx variant test, high prevalence of stx2a and stx2c (known to be associated with high STEC virulence) were observed, and stx2g, a bovine STEC variant, was detected in STEC O15 and O109. Additionally, stx1c was detected in eae-positive STEC, suggesting genetic dynamics among the virulence genes in the STEC isolates. STEC non-O157 strains were resistant to tetracycline (17.9%), ampicillin (14.3%), and cefotaxime (3.6%), while STEC O157 was susceptible to all tested antimicrobials, except cefotaxime. The antimicrobial resistance genes, bla TEM (17.5%), tetB (6.3%), and tetC (4.8%), were only detected in STEC non-O157, whereas tetE (54.0%) was detected in STEC O157. AmpC was detected in all STEC isolates. Clustering was performed based on the virulence gene profiles, which grouped STEC O84, O108, O111, and O157 together as potentially pathogenic STEC strains. Finally, PFGE suggested the presence of a prototype STEC that continues to evolve by genetic mutation and causes within- and between-farm transmission within the Gyeonggi province.ConclusionsConsiderable numbers of STEC non-O157 were isolated from cattle farms, and the virulence and antimicrobial resistance features were different between the STEC O157 and non-O157 strains. STEC from cattle with virulence or antimicrobial resistance genes might represent a threat to public health and therefore, continual surveillance of both STEC O157 and non-O157 would be beneficial for controlling and preventing STEC-related illness.

Occurrence and characterization of seven major Shiga toxin‐producing Escherichia coli serotypes from healthy cattle on cow–calf operations in South Africa

“…The prevalence of infected cattle per farm ranged from 2.9% to 43.3% consistent with reports from Japan and the United Kingdom which reported similar ranges (Ellis‐Iversen et al, ; Gunn et al, ; Lee, 2017). However, the farms prevalence rates obtained in this study were relatively lower in comparison to studies in Brazil, South Korea and USA cattle farms which reported up to 100% for cattle that tested positive for STEC (Cull et al, ; Dong et al, ; Pereira, Brod, Rodrigues, Carvalhal, & Aleixo, ). We also observed that particular serotypes were confined to specific farms.…”

Antibiotic resistance, virulence factors and genotyping of Uropathogenic Escherichia coli strains

“…Anvarinejad et al reported 9 to 16 DNA bands with molecular size of 2 to 660kbp in molecular typing of E. coli isolates from patients with cyctitis and pyelonephritis [ 57 ]. Dong et al reported 15–20 distinct bands in genotyping of Shiga toxin produced by E. coli isolates [ 41 ]. Ejrnaes et al reported 15–20 bands with 50kbp to 1200kbp molecular sizes by typing UPEC strains [ 8 ].…”

“…The PFGE profiles were compared using In silico stimulation of molecular experiment with a dice similarity coefficient and UPGMA analysis to create the dendrogram. To analyze genetic relatedness, cut off line at 85% was considered [ 38 – 41 ].…”

Characterization of Diarrheagenic Escherichia coli Isolated in Organic Waste Products (Cattle Fecal Matter, Manure and, Slurry) from Cattle’s Markets in Ouagadougou, Burkina Faso

“…The persistence and ability of ETEC to survive in effluents like cattle effluent are mostly unknown. However, ETEC could survive for up to three months in freshwater [ 43 ] and was able to form biofilms in a wet environment [ 44 ].…”