Mechanisms other than penicillin-binding protein-2 alterations may contribute to moderate penicillin resistance in Neisseria meningitidis

Penicillin resistance in Neisseria spp is thought to be generated by the in terspecies transfer of genetic material from naturally penicillin-resistant , commensal species. We examined a series of successive transformants with increasing levels of penicillin resistance, obtained by co-cultivation of N eisseria meningitidis derivatives with Neisseria polysaccharea. Our results suggest that, in addition to the well-known decrease in penicillin affinit y of penicillin-binding protein-2 (PBP-2), decreased expression of the clas s 3 porin as well as decreased affinity of PBP-1 may contribute to higher l evel resistance of N. meningitidis to penicillin G and other beta -lactam c ompounds. (C) 2001 Elsevier Science BN. and International Society of Chemot herapy. All rights reserved.