Prevalence of virulence genes and antibiotic-resistance genes in Escherichia coli isolated from cattle in the Mekong delta

Abstract

This study was conducted to determine the prevalence of virulence genes and antibiotic-resistance genes in 151 Escherichia coli strains isolated from cattle in the Mekong Delta in 2022, by PCR assay. The studied result showed that out of 151 isolated E. coli strains, there were 74 strains (49.01%) harboring from one to four virulence genes investigated. Among them, the rate of strains harboring the stx1 gene was the highest (14.57%), followed by the strains carrying two virulence genes: stx2 + hlyA (11.92%). Testing the antimicrobial susceptibility of the isolated E. coli strains with 13 antibiotics was carried out by Kirby–Bauer method. The tested result showed that the E. coli strains were sensitive with most of the antibiotics, However, there was still a high rate of E. coli strains resistant to ampicillin (47.68%), colistin (46.36%), streptomycin (43.71%), and tetracycline (41.72%). Those E. coli strains could resist from one to twelve antibiotics, and the resistance to 5 antibiotics (18.54%) was the most popular. The result of testing prevalence of five antibiotic-resistance genes (blaampC, blaTEM, blaCTX-M1, strA, and aadA1) showed that the blaampC gene was presented at all 151 E. coli strains (100%), followed by strA gene (45.70%), blaTEM gene (43.05%), and blaCTX-M1 (9.93%). Thirteen antibiotic-resistance patterns of E. coli strains were recognized, and the pattern of blaampC + blaTEM
+ strA was exhibited popularly (13.25%). The prevalence of virulence genes and antibiotic-resistance genes in E. coli isolated from cattle in the Mekong Delta indicate that these factors is a hazard that needs to concern to protect the animal and community health in the Mekong Delta.