Abstract
BackgroundShiga toxin-producing Escherichia coli (STEC) is a leading cause of worldwide food-borne and waterborne infections. Despite an increase in the number of STEC outbreaks, there is a lack of data on prevalence of STEC at the farm level, distribution of serogroups, and virulence factors.ResultsIn the present study, a total of 91 (6.16%) STEC strains were isolated from 1477 samples including pig intestines, pig feces, cattle feces, milk, and water from dairy farms. The isolation rates of STEC strains from pig intestines, pig feces, and cattle feces were 7.41% (32/432), 4.38% (21/480), and 9.57% (38/397), respectively. No STEC was isolated from the fresh milk and water samples. By O-serotyping methods, a total of 30 types of O-antigens were determined, and the main types were O100, O97, O91, O149, O26, O92, O102, O157, and O34. Detection of selected virulence genes (stx1, stx2, eae, ehxA, saa) revealed that over 94.51% (86/91) of the isolates carried more than two types of virulence associated genes, and approximately 71.43% (65/91) of the isolates carried both stx1 and stx2, simultaneously. Antimicrobial susceptibility tests showed that most of the STEC isolates were susceptible to ofloxacin and norfloxacin, but showed resistance to tetracycline, kanamycin, trimethoprim-sulfamethoxazole, streptomycin, amoxicillin, and ampicillin. MLST determined 13 categories of sequence types (STs), and ST297 (31.87%; 29/91) was the most dominant clone. This clone displayed a close relationship to virulent strains STEC ST678 (O104: H4). The prevalence of ST297 clones should receive more attentions.ConclusionsOur preliminary data revealed that a heterogeneous group of STEC is present, but the non-O157 serogroups and some ST clones such as ST297 should receive more attentions.
Highlights
Shiga toxin-producing Escherichia coli (STEC) is a leading cause of worldwide food-borne and waterborne infections
There are currently more than 100 types of O antigens having been determined from STEC isolates, and several serogroups such as O157, O26, O104, O45, O103, O111, O121, and O145 are commonly associated with severe illness in humans worldwide [2, 4, 6,7,8,9]
Of the 1477 samples detected, 119 (8.06%) samples were positive for stx1 and/or stx2
Summary
Shiga toxin-producing Escherichia coli (STEC) is a leading cause of worldwide food-borne and waterborne infections. A recent study has revealed that the overall prevalence of STEC O157:H7 was 41.3% along the production and supply chain of pork around Hubei Province in Central China, and the prevalence found in slaughter houses, wet- and supermarkets were 86.25% (69/80), 53.3% (32/60), and 28.3% (17/60), respectively [13]. These data suggest a big threat to the food safety and even human health in this region
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
