PENICILLIN-RESISTANT STAPHYLOCOCCI: MECHANISMS INVOLVED IN THE DEVELOPMENT OF RESISTANCE

Abstract

Two types of resistance to penicillin have been descr. for staphylococci. The first is an adaptation in vitro; resistance is temporary and not associated with the production of penicillinase. The 2d type is associated with naturally penicillin-resistant strains or with strains which hate become resistant in patients after treatment with penicillin. This resistance is permanent, and the strains produce penicillinase. The mechanism whereby temporary resistance takes place is not clearly understood. The permanent type involves the presence of resistant cells in a penicillin-sensitive strain, which, when permitted to multiply rapidly, establish a uniformly resistant strain. The magnitude of the resistance manifested by the permanent type is quantitatively related to the potency of penicillinase produced by the strains. Establishment of resistant strains of staphylococcus in the human body can be prevented by the prompt use of adequate quantities of penicillin.