ADHERENCE AND HYDROPHOBICITY OF INVASIVE AND NONINVASIVE STRAINS OF PORPHYROMONAS-GINGIVALIS

The adherence of Porphyromonas gingivalis to cell surfaces of periodon tal tissues may play an important role in its pathogenicity. In this s tudy, 12 strains of P. gingivalis, including both invasive and noninva sive strains, were investigated for adherence to gingival ligament com ponents. The test strains of P. gingivalis adhered to collagen, fibron ectin, and laminin to significantly different degrees. An overall posi tive correlation was noted between hydrophobicity and the number of ce lls that attached to collagen coated on hydroxyapatite beads. Invasive strains had low hydrophobicity and bound less to collagen than did no ninvasive strains that possessed strong hydrophobic properties. H-3-fi mbriae extracted from P. gingivalis were found to attach to collagen-c oated hydroxyapatite. The fimbriae extracted from noninvasive strains bound strongly to collagen, whereas invasive strains' fimbriae with lo w hydrophobicity bound weakly to collagen or saliva-coated hydroxyapat ite. These data suggest that 1) fimbriae play an important role in col onization through their hydrophobic activity; 2) fimbriae of noninvasi ve strains are associated with the major adhesin for attachment to gin gival tissue, whereas fimbriae of invasive strains are weakly involved in adherence; and 3) there is no correlation between colonization and the invasiveness of P. gingivalis.