Abstract

Gali Abaka Umaru*, Junaidu Kabir, Veronica J. Umoh , Mohammed Bello, and Jacob K. P. Kwaga

A study was conducted to determine the occurrence of vancomycin resistant S. aureus (VRSA) in milk in Nigeria. Fourty seven S. aureus were isolated from the 372 milk samples examined, out of which 20 (5.4%) were vancomycin-resistant. Fifteen (4%) of the VRSA were isolated from raw milk, 4 (1.1%) from bulk milk and 1 (0.3%) from pasteurized milk. No significant difference (P > 0.05) between the occurrence among the study variables was observed, . No VRSA occurred in the yogurt and ‘kindirmo’ samples examined. The decrease in the occurrence of the pathogen from raw milk to pasteurized milk and its absence in yogurt and ‘kidirmo’ suggest that pasteurization and fermentation may have eliminated most of the organisms. The resistance profiles of the VRSA isolates to other antibiotics showed high resistance to penicillin (100%), tetracycline (85%), amoxicillin (65%), methicillin (40%) and oxacillin (40%), but low to amikacin (5%) and sulphamethoxazole/trimethoprim (10%). None of the isolates were resistant to chloramphenicol and ciprofloxacin. The multiple antibiotic resistance index result revealed that 80% of the VRSA were resistant to 3 or more antibiotics. The presence of VRSA coupled with the multple resistance patterns of these isolates are of great concern and also of public health significance. Therefore more studies on the epidemiology of this pathogen in foods are required.