Detection, antibiogram and molecular characterization of MRSA and MSSA isolated from swine

Abstract

The emergence of bacteria with antimicrobial resistance traits such as methicillin-resistant Staphylococcus aureus (MRSA) in food-producing animals is a significant public health concern. The aim of this study is to determine the prevalence rate, antibiotic susceptibility and the molecular characteristics of Staphylococcus aureus (S. aureus) in swine from selected swine farms in Peninsular Malaysia. The oral and nasal swabs of 200 live swine were collected. Screening and isolation of S. aureus isolates were carried out using phenotypic identification techniques. The identity of the bacteria isolates was confirmed by detection of nuc gene (S. aureus) and mecA gene (MRSA). Antibiogram of S. aureus against 19 antibiotics was developed using Kirby-Bauer test. Molecular detections of antimicrobial resistance and virulence genes as well spa typing of S. aureus was carried out. 25% of swine were carrying S. aureus with 9% being MRSA carriers. S. aureus and MRSA have shown high resistance against clindamycin, tetracycline, chloramphenicol, oxacillin, penicillin, erythromycin, cefoxitin and amoxicillin/clavulanate. Antimicrobial resistance and virulence genes, including tetK, tetL, tetM, ermA, ermB, ermC, msrA and scn genes were detected. 93% of S. aureus were multiple-drug resistant (MDR), suggesting the emergence of MDR S. aureus in swine in Malaysia.