Unveiling Antimicrobial Resistance Patterns in Escherichia coli and Staphylococcus spp. Isolates of Livestock and Poultry

AbstractIndia’s livestock sector is a major reservoir for bacterial pathogens and a potential source of antimicrobial resistance. We investigated the prevalence and antimicrobial resistance mechanisms in Staphylococcus spp. and Escherichia coli from livestock and poultry isolates from Sambhal district, Uttar Pradesh. A total of 173 samples (cow and buffalo milk and rectal, goat rectal, and poultry cloacal swabs) were collected and cultured. Staphylococci were isolated from 55 of 65 milk samples (84.6%), including 12 S. aureus (21.8% of Staphylococci). Fifteen of 55 isolates (27.3%) were methicillin-resistant. Penicillin (43.6%) and erythromycin (23.6%) resistance predominated, while all isolates remained linezolid susceptible. E. coli prevalence was 71.1% (123/173). High resistance was observed to ampicillin (59.3%), ceftriaxone (39.0%), and cefotaxime (29.3%). ESBL and AmpC phenotypes were detected in 20 (16.3%) and 11 (8.9%) isolates, respectively; carbapenem resistance was rare and mCIM-negative. Multivariate clustering revealed sample-type and host-associated resistance patterns with considerable overlap between bovine and poultry isolates.