[Drug resistance of Staphylococcus aureus in the field of obstetrics and gynecology].

Clinical isolates of bacteria from Department of Obstetrics and Gynecology were collected and their microbiological properties were investigated. The isolation frequencies of bacteria from this Department were almost similar to those from other hospitals, indicating the high isolation frequencies of gram-positive cocci. The drug resistance to various chemotherapeutic agents of Staphylococcus aureus including beta-lactam antibiotics was studied. It should be noted that the bacteria resistant to beta-lactam antibiotics were most often isolated and the resistance was due to the production of penicillinase. Methicillin-resistant strains of S. aureus were isolated from this Department at a high frequency. It was found that these strains are also resistant to many penicillins and cephems including methicillin. Methicillin resistance of these strains was found to be not due to the production of penicillinase. Examination of the penicillin-binding proteins (PBPs) revealed that a new PBP-2' was produced in a large amount, suggesting that the mechanism of methicillin-resistance was due to the production of the new PBP-2' as reported previously, not to the production of beta-lactamase. The increased isolation of methicillin-resistant strains may be due to the introduction and the overuse of beta-lactamase resistant antibiotics.