Genetic and antimicrobial resistance profiles of non-O157 Shiga toxin-producing Escherichia coli from different sources in Egypt

Abstract Background The Shiga toxin-producingEscherichia coli(STEC) represented a great risk to public health. In this study, 60 STEC strains recovered from broiler and duck fecal samples, cow’s milk, cattle beef, human urine, and ear discharge were screened for 12 virulence genes, phenotypic and genotypic antimicrobial resistance, and multiple-locus variable-number tandem-repeat analysis (MLVA). Results The majority of strains harbored Shiga toxin 1 (stx1) andstx1d,stx2andstx2e, andehxA genes, while a minority harboredstx2csubtype andeaeA. We identified 10stxgene combinations; most of strains 31/60 (51.7%) exhibited four copies ofstxgenes, namely thestx1,stx1d,stx2, andstx2e, and the strains exhibited a high range of multiple antimicrobial resistance indices. The resistance genesblaCTX-M-1 andblaTEM were detected. For the oxytetracycline resistance genes, most of strains containedtetA,tetB,tetE, andtetG while thetetC was present at low frequency. MLVA genotyping resolved 26 unique genotypes; genotype 21 was highly prevalent. The six highly discriminatory loci DI = 0.9138 are suitable for the preliminary genotyping of STEC from animals and humans. Conclusions The STEC isolated from animals are virulent, resistant to antimicrobials, and genetically diverse, thus demands greater attention for the potential risk to human.