Penicillinase of Staphylococci isolated from milk and dairy products

: Examinations were performed in 173 strains of Staphylococcus aureus isolated from milk and dairy products. Of this number, 143 strains were resistant and 30 sensitive to penicillin. All the resistant strains produced penicillinase. Penicillinase production was demonstrated also in vivo by a test on white mice.