Affiliation:
1. Department of Oral Biology, University of Florida, Gainesville, Florida 32610,1 and
2. Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 352942
Abstract
ABSTRACT
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.
Publisher
American Society for Microbiology
Subject
Infectious Diseases,Immunology,Microbiology,Parasitology
Cited by
88 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献