Phenotypic and Genotypic Characterization of Antimicrobial Resistance in Enterococcus species from Dairy Niches

The study investigated the prevalence of antimicrobial resistance (AMR) in dairy enterococci. 140 enterococci strains were isolated from dairy samples, and 104 isolates were tested for antimicrobial susceptibility. The most prevalent resistance was against cephalosporins, followed by fosfomycin, rifampicin, and erythromycin. The multi-antibiotic resistance index ranged from 0.09-0.36. AMR genes against aminoglycoside, tetracyclines, macrolides, chloramphenicol, and multi-drug transporter genes were detected in many isolates. The study also found a high frequency of mobile genetic elements, virulence traits, and mobile genetic elements in resistant enterococci isolates. Although virulence traits could not be directly correlated with AMR resistance, the study highlights the wide prevalence of AMR in dairy enterococci and its potential contribution to food chain issues.