Prevalence of antimicrobial resistant pathotypes of Escherichia coli in beef cattle and slaughterhouse premise

Abstract

The study was undertaken to assess distribution of antimicrobial resistant and virulent genes in 72 Escherichia coli isolated from beef cattle and slaughter house. All the isolates were subjected for detection of virulent genes viz. stx1 and stx2 of shigatoxic E. coli (STEC), Lth of Enterotoxigenic E. coli (ETEC); antimicrobial resistant genes tetA, tetB, tetC for tetracycline and strA, strB for streptomycin by PCR assay. The Stx1 and Stx2 genes could be detected in 9.72 and 15.28% of the E. coli isolates, respectively. None of the isolates harbored both Stx1 and Stx2 genes in combination. However, 1.38 and 2.77% of the isolates, respectively possessed combinations of Stx1 and Lth and Stx2 and Lth. ETEC was the predominant pathotype isolated (31.94%) as compared to STEC (25%). Isolates exhibited maximum sensitivity to antimicrobials cephotaxim, ciprofloxacin, norfloxacin and cefriaxone, and resistance to gentamicin, cloxacillin and ampicillin. Tetracycline and streptomycin resistant genes were detected in 17 (23.61%) and 19 (26.38%) E. coli isolates, respectively. tetB and strA+strB were predominant genes harbored whereas tetC gene was not detected in any of the isolate. Observations of the present study conclude that E. coli isolates harboring drug resistant genes could be widely distributed in beef cattle and slaughter house environment. It may create a pool of transferable resistance genes for other pathogens in simulated environment. Since slaughtering and meat handling operations at majority of municipal slaughterhouses in India are unhygienic producing very conducive environment for foodborne environmental pathogens, this study suggests the need for effective implementation of good hygienic practices (GHP) in slaughterhouses to reduce the risks of contamination with antimicrobial-resistant bacteria.