title: The capacity of Porphyromonas gingivalis to multiply under iron-limiting conditions correlates with its pathogenicity in an animal model.
abstract: Isolates of Porphyromonas gingivalis have various abilities to induce infections in an animal model. The hypothesis of this study was that pathogenic strains of P. gingivalis could multiply under iron-limiting conditions, while non-pathogenic strains could not. Three pathogenic strains (W50, W83, and ATCC 49417) grew to a final optical density (660 nm) > 2 in horse serum, while the growth of the 3 non-pathogenic strains (ATCC 33277, LB13D-2, and HW24D-1) was negligible. When an excess of hemin or ferric chloride was added to the serum, significant growth of the non-pathogenic strains occurred. Under iron-limiting conditions, the pathogenic strains of P. gingivalis had a much lower requirement for human iron-loaded transferrin and hemin than the non-pathogenic strains. Proteolytic degradation of transferrin, which may be associated with the release of iron, was not markedly different for pathogenic and non-pathogenic strains. In addition, no relationship could be established between the level of 55Fe uptake from 55Fe-transferrin and the pathogenicity of strains. Our study provided evidence that the ability of P. gingivalis to multiply in vitro under iron-limiting conditions may be correlated with its ability to induce infections in an animal model. Isolates of P. gingivalis possessing a low requirement for iron are likely to have a higher potential for initiating periodontal infections.
authors.affiliation: Groupe de Recherche en Ecologie Buccale, Faculté de Médecine Dentaire, Université Laval, Québec, Canada. Daniel.Grenier@greb.ulaval.ca
authors.forename: D
authors.initials: D
authors.lastname: Grenier
authors.forename: V
authors.initials: V
authors.lastname: Goulet
authors.forename: D
authors.initials: D
authors.lastname: Mayrand
mesh_terms: D000818:Animals; D002455:Cell Division; D003470:Culture Media; D004195:Disease Models, Animal; D006427:Hemin / Q000378:metabolism; D006736:Horses; D006801:Humans; D007501:Iron / Q000378:metabolism*; D007504:Iron Radioisotopes / Q000378:metabolism; D010518:Periodontitis / Q000382:microbiology; D016966:Porphyromonas gingivalis / Q000378:metabolism* / Q000472:pathogenicity*; D014168:Transferrin / Q000378:metabolism; D014774:Virulence
chemical_list: D003470:Culture Media; D007504:Iron Radioisotopes; D014168:Transferrin; D006427:Hemin; D007501:Iron