PENICILLIN RESISTANCE DEVELOPMENT IN PEPTOSTREPTOCOCCI

Recent isolates of P. anaerobius, P. magnus and P. prevotii exhibiting different levels of resistance to penicillin were selected. PBP profi les, penicillin affinity and cefoxitin and imipenem competition studie s were performed to identify target PBPs. The PBP profiles of the pept ostreptococci were species specific. PBPs 1 and 2 of 3 PBPs demonstrat ed in P. anaerobius and PBPs 1 and 2 of 4 major PBP groups of P. magnu s were identified as target PBPs for penicillin activity. Imipenem was found to be more effective than penicillin or cefoxitin against the p eptostreptococci studied. Monitoring of peptostreptococcal PBP alterat ions should be continued as exposure especially to the newer beta-lact am antibiotics increases.