Molecular detection of avian pathogenic Escherichia coli (APEC) in broiler meat from retail meat shop

Abstract

Avian pathogenic Escherichia coli (APEC) is a major bacterial pathogen responsible for the most widespread form of colibacillosis, resulting in substantial economic losses within the poultry sector and posing a potential public health risk. From July to September 2021, our study investigated the antibiotic resistance pattern of Escherichia coli (E. coli) and the presence of virulence-associated genes (iucD, iutA, iss, and ompT) linked to APEC using 105 broiler meat samples comprising liver, thigh, and breast muscle, in Chitwan, Nepal. E. coli was isolated and identified by culturing samples on MacConkey's agar, Eosin-methylene blue (EMB) agar and performing different biochemical tests. Antibiotic resistance patterns of E. coli were determined by the Kirby-Bauer disc diffusion method. Following the isolation of E. coli, the molecular detection of APEC was performed using conventional polymerase chain reaction (PCR). Out of the 105 samples analyzed, 61 (58.1 %) tested positive for E. coli. In antibiotic susceptibility test (AST), gentamicin and tetracycline exhibited the highest resistance rates, with 90.2 % and 67.2 %, respectively and 29.5 % of the E. coli isolates displayed multidrug-drug resistance. Out of 61 confirmed E. coli isolates, iutA was detected in 47 (77.0 %) samples, iucD in 46 (75.4 %), iss in 53 (86.8 %), and ompT in 39 (63.9 %) samples. This study reports the occurrence of MDR E. coli in meat samples, together with virulence genes associated with APEC which poses a public health threat. Continuous surveillance is vital for monitoring APEC transmission within poultry farms, coupled with efforts to raise awareness of food safety among consumers of broiler meat.