Antibiogram, Phenotypic and Genotypic Detection of Extended-Spectrum β-lactamase Producing and Fluoroquinolone Resistant Escherichia coli Isolated from Pigs

Antimicrobial resistance in food animals is a global issue. Particularly, the dissemination of Extended Spectrum Beta-Lactamase and fluoroquinolone resistant Escherichia coli in food-producing animals posed a public health threat to the efficacy of various antibiotics. Therefore, this study aimed to detect the presence of multidrug-resistant Escherichia coli from fecal samples of pigs in Puducherry. In total, 16 faecal samples from apparently healthy pigs of different age groups were chosen for this study and subjected to detection of ESBL production and FQ resistance. E. coli was isolated from all the faecal samples (100%) and confirmed by biochemical tests and Polymerase Chain Reaction. All the E. coli isolates were found to be positive for ESBL production and fluoroquinolone resistance by phenotypic method. Out of 16 E. coli isolates, 11 (68.75%) isolates were positive for the presence of ESBL-producing genes, in which, 2 harbored bla TEM and 9 harboured bla SHV genes. In total 13/16 (81.2%) E. coli isolates harbored PMQR genes, in which 11 isolates harbored the qnrS gene and 11 isolates harbored the qnrB gene. The results showed that 9 isolates harbored both qnrS and qnrB genes in combination. Antimicrobial susceptibility test showed that the majority of the isolates exhibited a high level of resistance against Amoxycillin/clavulanic acid (100%), Cefpodoxime (100%), Cefotaxime (80%), Aztreonam (70%), Ceftazidime (70%), Enrofloxacin (70%) and Ceftriaxone (40%). The present study showed the presence of ESBL-producing and FQ-resistant E. coli in swine in the Puducherry region and their antibiogram pattern.