Association of the rgpB gingipain genotype to the major fimbriae (fimA) genotype in clinical isolates of the periodontal pathogen Porphyromonas gingivalis

摘要

BackgroundPorphyromonas gingivalis produces outer membrane-attached proteins that include the virulence-associated cysteine proteinases RgpA and RgpB (Arg-gingipains) and Kgp (Lys-gingipain). The gingipains provide P. gingivalis with a general proteolytic tool for degradation of proteinaceous nutrients for growth. They are also essential for the processing and maturation of the major fimbriae (FimA) which are important in facilitating bacterial adhesion to host tissues. FimA has been characterized as an important virulence factor for P. gingivalis, and many studies, both animal experiments and clinical investigations, have characterized fimA genotypes II, Ib, and IV to be associated with disease (periodontitis and cardiovascular disease) while genotypes I, III, and V represent avirulent strains. The relationship between virulence and gene variation of the rgpB gene has not been investigated extensively. However, nucleotide variations of the rgpB gene result in four amino acid substitutions in the catalyti...