Prevalence and molecular characterization of Multidrug-Resistant ESBL-Producing E. coli in commercial poultry

Abstract

Background: Rural poultry farmers are gradually changing from the backyard poultry production to intensive production, which made poultry more vulnerable to diseases and lead to indiscriminate use of antimicrobials in poultry production. As per OIE, FAO and WHO, multiple spread antimicrobial resistant pathogenic bacteria are a serious global human and animal health problem. Hence the study has been carried out to know the antimicrobial resistance status of poultry in Tirunelveli, Tamil Nadu, India. Methods: The study was aimed to find the occurrence of extended spectrum beta lactamases (ESBLs) producing E. coli from poultry origin. Caecum samples from the broiler (n=180), desi chicken (n=180) and Japanese quail (n=180) were processed for the isolation and phenotypic identification of ESBL E. coli. The isolates were tested for antimicrobial susceptibility test and characterization of ESBL and virulence genes done by PCR. Result: On phenotypic confirmation of ESBL producing E. coli by combined disk diffusion test (CDDT), a total of 9.63% samples were positive for extended spectrum beta lactamase producer (ESBL). Multi drug resistance (MDR) was observed in 38.23% of the broiler isolates, 27.27% and 57.14% in desi chicken and Japanese quail isolates, respectively. All the phenotypically confirmed ESBL producing E. coli isolates (n=52) were positive for uspA gene by PCR confirming the isolates as E. coli. The overall presence of the blaTEM gene was 57.69%, with broiler isolates having the highest prevalence of 67.47%, followed by desi chicken 36.36% and Japanese quail 42.85%. In contrast, the blaSHV gene was found in only 17.64% of the broiler isolates, but none were positive for the blaCTXM and blaOXA-1 gene.