Multidrug-resistant Escherichia coli in retail chicken meat: A Cross-sectional study from Kerala, India

This study investigated the prevalence, virulence, and antimicrobial resistance (AMR) of Escherichia coli in retail chicken meat samples from six districts in Kerala, India, collected between 2019 and 2023. A cross-sectional analysis of 600 samples revealed a 54.17 % prevalence of E. coli , with 8 % of isolates carrying virulence genes for typical enteropathogenic E. coli (EPEC), indicating significant pathogenic potential. Antibiotic susceptibility testing against nine World Health Organization recommended antimicrobials showed high resistance, notably to nalidixic acid (55.07 %), trimethoprim (46.01 %), and co-trimoxazole (40.58 %). Multidrug resistance was observed in 49.28 % of isolates, with a multiple antibiotic resistance (MAR) index ranging from 0 to 0.89. Genotypic analysis using PCR and Mismatch Amplification Mutation Assay (MAMA-PCR) identified resistance genes such as blaTEM, bla CTXM, bla SHV, tetA, tetB, dfrA1, dfrA2, sul1, sul2, aadA1, aadA2, catA alongside point mutations in gyrA and parC genes conferring quinolone resistance. These findings highlight the public health risks posed by AMR in poultry, emphasizing the need for enhanced surveillance and control strategies to mitigate the spread of resistant pathogens through the food chain. • E. coli was detected in 54.17 % of retail chicken meat; highlighting a major public health concern. • Multiple virulence genes ( eaeA , bfpA , aggR and ipaH ) were detected in the isolates using multiplex PCR. • The isolates showed highest resistance to nalidixic acid (55.07 %),trimethoprim (46.01 %) and co-trimoxazole (40.58 %). Multidrug resistance was detected in 49.28 % isolates. • PCR confirmed resistance genes and point mutations in the QRDR by MAMA PCR, proving molecular resistance. • Improved surveillance, hygiene, judicious use of antibiotics and One Health strategies are needed to curtail the spread of multidrug resistant E.coli via food chain