The study was carried out to determine the prevalence and antibiotics resistance of S. aureus in raw milk samples obtained from dairy farms in Penang, Malaysia. A total of 60 samples were examined and all the samples examined were positive for S. aureus with counts ranging from 2.88 to 3.41 log cfu/mL. Milk samples obtained from different farms had similar S. aureus counts (P>0.05). All the isolates examined were susceptible to gentamycin, kanamycin, chloramphenicol and ciprofloxacin. S. aureus isolates were resistant to penicillin (23.3), ampicillin (23.3%), trimethoprim (18.3%), cefoxitin (15.0%), linezolid (11.7%), clindamycin (10.0%), erythromycin (8.3%) and tetracycline (5.0%). 28.3% of the isolates were resistant to at least one antibiotic with MAR index ranging from 0.08 to 0.67. The following genes, blaZ, ermA and tetK were detected in 9, 5 and 1 isolate/s of S. aureus respectively. Presence of high S. aureus counts and antibiotic resistant strains of S. aureus might pose a health hazard if milk is not pasteurized adequately and prolonged storage of milk after milking at ambient temperature might further aggravate the problem.

Key words: Antibiotics susceptibility, Raw milk, Resistance gene, S. aureus