Test S. aureus Total
MSA 99 (25%) 400
OX-Disk 27 (27%) 99
OX-Broth 23 (23%) 99
Table 3: Results for initial characterization of isolates as S. aureus on MSA and oxacillin-resistance screened by disc diffusion and confirmed by growth in MH supplemented with 4 μg/ml of oxacillin. Percentage positive for MSA was determined as positive out of 400 samples (two sites on 200 students) while percentage positive for resistance was determined by positive out of 99 S. aureus isolates.