Induction of beta-lactamase enzymes: clinical applications for the obstetric-gynecologic patient.

The emergence of bacteria resistant to antibiotics has resulted in intensive research for new and improved beta-lactam antibiotics. Many improvements in antimicrobial agents are based on a knowledge of the mechanism responsible for resistance. This has led to the development of new extended-spectrum antibiotic compounds. However, several features have been noted since the development of extended-spectrum antibiotics, such as the rapid development of bacterial resistance, the induction of beta-lactamase enzyme activity by these stable antibiotics, failure to detect induced enzyme activity and resistance in the laboratory, and beta-lactam antagonism. The resistance of bacteria to antimicrobial agents has obvious impact on the selection of appropriate therapy against infections caused by these pathogens. Gram-negative anaerobic bacteria, such as Bacteroides fragilis and Bacteroides bivius, are organisms frequently recovered from women whose initial therapy for pelvic infection failed. The transfer of antimicrobial resistance in bacteria indicates that these organisms have a system for the spread of such resistance. Therefore determination of antimicrobial susceptibilities and prompt eradication of isolates from infected patients are necessary to delay the emergence of resistant organisms.