ANTIBIOTIC RESISTANCE OF PATHOGENIC STAPHYLOCOCCI

Abstract

SOON AFTER interest in Fleming's penicillin was reawakened through the work of Chain and Florey¹and their associates, there appeared evidence of the occurrence of penicillin-resistant strains of pathogenic staphylococci after exposure to penicillin both in vitro and in vivo.²In 1945, North and Christie³obtained 128 strains of staphylococci (88 coagulase producers and 40 not coagulase producers) from one hospital where penicillin had not been used and compared them with 31 coagulase-positive strains isolated from patients in another hospital where penicillin was being used extensively. The coagulase-positive strains from the former hospital were all inhibited by 1/8 unit or less, while the coagulase-negative ones were all completely inhibited by 1/2 unit or less. By contrast, only 13 of the strains from the hospital where penicillin was widely used were inhibited by less than 1 unit, and 17 required 2 to 80 units. Since that time many