Virulence of a spaP Mutant of Streptococcus mutans in a Gnotobiotic Rat Model
| Autor: | Arnold S. Bleiweis, L. Jeannine Brady, Suzanne M. Michalek, Paula J. Crowley |
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| Rok vydání: | 1999 |
| Předmět: |
Immunology
Mutant Virulence Mutagenesis (molecular biology technique) Biology Microbiology Virulence factor Streptococcus mutans Bacterial Proteins Antigen Animals Germ-Free Life Membrane Glycoproteins Tooth surface Bacterial Infections biology.organism_classification Streptococcaceae Rats Inbred F344 Rats stomatognathic diseases Infectious Diseases Mutation Parasitology |
| Zdroj: | Infection and Immunity. 67:1201-1206 |
| ISSN: | 1098-5522 0019-9567 |
| DOI: | 10.1128/iai.67.3.1201-1206.1999 |
| Popis: | Streptococcus mutans , the principal etiologic agent of dental caries in humans, possesses a variety of virulence traits that enable it to establish itself in the oral cavity and initiate disease. A 185-kDa cell surface-localized protein known variously as antigen I/II, antigen B, PAc, and P1 has been postulated to be a virulence factor in S. mutans . We showed previously that P1 expression is necessary for in vitro adherence of S. mutans to salivary agglutinin-coated hydroxyapatite as well as for fluid-phase aggregation. Since adherence of the organism is a necessary first step toward colonization of the tooth surface, we sought to determine what effect deletion of the gene for P1, spaP , has on the colonization and subsequent cariogenicity of this organism in vivo. Germ-free Fischer rats fed a diet containing 5% sucrose were infected with either S. mutans NG8 or an NG8-derived spaP mutant strain, PC3370, which had been constructed by allelic exchange mutagenesis. At 1-week intervals for 6 weeks after infection, total organisms recovered from mandibles were enumerated. At week 6, caries lesions also were scored. A significantly lower number of enamel and dentinal carious lesions was observed for the mutant-infected rats, although there was no difference between parent and mutant in the number of organisms recovered from teeth through 6 weeks postinfection. Coinfection of animals with both parent and mutant strains resulted in an increasing predominance of the mutant strain being recovered over time, suggesting that P1 is not a necessary prerequisite for colonization. These data do, however, suggest a role for P1 in the virulence of S. mutans , as reflected by a decrease in the cariogenicity of bacteria lacking this surface protein. |
| Databáze: | OpenAIRE |
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