Abstract
•150 cloacal swabs were aseptically obtained from chickens on different farms in Taif, Saudi Arabia.•99% of the 180 analysed Escherichia coli isolates were multidrug-resistant.•The most prevalent resistance genes were blaSHV, tet(A/B) and catA1/cmlA (96%, 95% and 72%, respectively).
Poultry is one of the main sources of food in the world. Antimicrobial-resistant Escherichia coli can be transmitted to humans by contact with poultry waste or by contaminated poultry products, contributing to the increasing crisis of antimicrobial resistance. This study aimed to determine the incidence of antimicrobial resistance in E. coli isolated from chickens in Taif province, Saudi Arabia, and to identify the genes responsible for any resistance observed.
A total of 150 cloacal swabs were aseptically obtained from chickens from different farms, from which 180 colonies of E. coli were identified using standard microbiology procedures. Antimicrobial susceptibility testing was performed by the Kirby–Bauer disk diffusion method. The genes blaSHV, aac(3)-IV, tet(A), tet(B), aadA1, catA1, cmlA, ere(A) and sul1 were detected by PCR.
Most of the E. coli isolates showed resistance to oxacillin (99%), lincomycin (98%) and oxytetracycline (97%). The prevalence of resistance to chloramphenicol (73%), ciprofloxacin (59%) and ampicillin (51%) was lower. Genes conferring resistance to β-lactams (blaSHV) and tetracyclines [tet(A) and tet(B)] were observed at prevalences of 96% and 95%, respectively, among the E. coli isolates. Chloramphenicol (catA1 and cmlA) and erythromycin [ere(A)] resistance genes showed prevalences of 72% and 15%, respectively, whereas gentamicin [aac(3)-IV], streptomycin (aadA1) and sulfonamide (sul1) resistance genes were detected in 20%, 20% and 10% of the studied isolates, respectively.
A significant prevalence of antimicrobial resistance genes was observed among E. coli isolates from farm chickens, supporting strict regulatory procedures for the use of antimicrobial agents.