Isolation and Characterization of Shiga Toxin–Producing Escherichia coli from Retail Beef Samples from Eight Provinces in China

Abstract

While Shiga toxin-producing Escherichia coli (STEC) is a major foodborne pathogen worldwide, data on the molecular and phylogenetic properties of STEC isolates from retail beef samples in China remain scant. Fresh retail beef samples (n = 1062) were collected from eight provinces, and STEC isolates were recovered and characterized. PCR data showed that more than 50% of the samples were stx positive, and 82 STEC isolates were recovered from 14.8% (79/535) stx-positive enriched broths. In contrast, all ciprofloxacin resistant isolates (n = 19) and 13 cefotaxime (CTX) resistant isolates were eae positive and belonged to three serotypes: O111:H8, O26:H11, or O157:H7. Point mutations in quinolone resistance-determining regions and plasmid-mediated quinolone resistance determinants were identified in 16 and 20 isolates, respectively. Bla CTX-M and a point mutation (C-42T) in ampC promoter were detected in 15 and 8 of the CTX resistant isolates, respectively. In addition, macrolide resistance gene mphA was identified in eight azithromycin resistant O111:H8 isolates and one O26:H11 isolate. Single nucleotide polymorphism analysis demonstrated that the O26 and O157 isolates had multiple origins, but the O111 isolates were closely related. Taken together, our data demonstrated that several sequence types associated with hemolytic uremic syndrome from the retail beef samples in China had developed into dangerous multidrug resistant pathogens. The resistant phenotype can facilitate their transmission among the farm animals and human beings when there is an antimicrobial selective pressure.

Domestic cats are potential reservoirs of multidrug-resistant human enteropathogenic E. coli strains in Bangladesh

“…Strains of E. coli that produce STEC are the reason for an array of infections in people and animals, encompassing gastrointestinal and extra-intestinal difficulties like urinary tract infections. ( Bentancor et al, 2007 , Hu et al, 2021 , Pan et al, 2021 ). Extra-intestinal pathogenic E. coli ’s (ExPEC) involvement in causing severe infections has recently attracted attention regarding its zoonosis from a veterinary clinical standpoint ( Bélanger et al, 2011 , Pitout, 2012 , Najafi et al, 2019 ).…”

High prevalence and pathogenic potential of Shiga toxin-producing Escherichia coli strains in raw mutton and beef in Shandong, China

“…In China, various studies have shown STEC contaminations in raw meats ( Bai et al, 2015 ; Chao et al, 2007 ; Dong et al, 2020 ; Li et al, 2011 ; Zhou et al, 2002 ). Of note, a recent study reported multidrug resistant STEC strains with high pathogenic potential from retail beef in China ( Hu et al, 2021 ), this knowledge is limited for mutton-derived strains. The objective of this study was to depict the prevalence, genomic and antimicrobial characteristics of STEC strains in retail raw meats with a particular interest on mutton in Jinan, Shandong, China, and to assess their pathogenic potential.…”