Penicillin-binding proteins in Fusobacterium species

PBPs were identified in four species of Fusobacterium. Each species had 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. nucleatum tested had characteristic ''wavy'' PBP patterns. F. mortiferum was distinctive in possessing a very major band or complex at the PBP-2 position, whereas F. varium and F. necrophorum had only minor or average bands. The antibiotics tested had varying affinities for the different PBPs and distinctive morphological changes were seen upon exposure 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, which caused elongation in F. varium, also had affinity for PBP-4 in that strain. (C) 1996 Academic Press