[Virulent properties of Porphyromonas gingivalis clinical strains].

To investigate the virulent properties of P. gingivalis clinical strains.By using mouse abscess model (MAM), six P. gingivalis clinical strains, L2, L3, L4, L5, L11 and L12 were subcutaneously inoculated into the central back of BALB/C mice. The clinical signs of the mice were observed and the virulent properties of the clinical strains were analyzed by comparison with type strains of W83 and ATCC 33277. SPSS11.5 software package was used for statistical analysis.According to the criteria established in previous reports, L3, ATCC33277, and W83 produced a localized abscess at the site of injection and were categorized as noninvasive. L2, L5, L11, and L12-induced lesions spread to distant organs and may produce severe systemic reactions and these strains were classified as invasive.Clinical strains from Chinese patients showed similarities to type strains in MAM. The virulent properties of P. gingivalis clinical strains are quite different from each other.