Inducible and constitutive synthesis of penicillinase by staphylococcus aureus

Abstract

When tested quantitatively for the production of penicillinase, eighteen of one hundred and twenty-two naturally occurring penicillin-resistant staphylococci were classified as constitutive or microconstitutive. Fourteen of the constitutive strains were not typable, the other four were lysed by group III phage. The inducible and constitutive strains of Staphylococcus aureus were resistant to concentrations of mercuric chloride that inhibited strains sensitive to penicillin. Transfer of the penicillinase determinant by transduction from a microconstitutive strain to a sensitive strain resulted in recombinants that produced inducible penicillinase.