PENICILLIN-BINDING PROTEINS IN FUSOBACTERIUM SPECIES

PBPs were identified in four species of Fusobacterium. Each species ha d a distinctive PBP pattern, although some intra-species variation was noted. Most species had five or six PBPs, ranging in molecular weight from similar to 100 kDa to similar to 40 kDa. The two strains of F. n ucleatum tested had characteristic ''wavy'' PBP patterns. F. mortiferu m was distinctive in possessing a very major band or complex at the PB P-2 position, whereas F. varium and F. necrophorum had only minor or a verage bands. The antibiotics tested had varying affinities for the di fferent PBPs and distinctive morphological changes were seen upon expo sure of the organisms to certain beta-lactam agents. Cefotaxime, which caused elongation in strains of two species, had greater affinity for PBPs 1 and 4 than for the other PBPs in those strains. Aztreonam, whi ch caused elongation in F. varium, also had affinity for PBP-4 in that strain. (C) 1996 Academic Press