Colonization and persistence of rough and smooth colony variants of Actinobacillus actinomycetemcomitans in the mouths of rats

Fine, Daniel H.; Goncharoff, Paul; Schreiner, Helen; Chang, Kai Ming; Furgang, David; Figurski, David H.

doi:10.1016/s0003-9969(01)00067-x

Cited by 47 publications

(55 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…To test the hypothesis that genes from the tad locus are required for the virulence of A. actinomycetemcomitans, we have developed an animal model for colonization and disease. These results support and extend our previous findings that show a wild-type clinical isolate is able to colonize and persist in the oral cavity of rats (2). In addition, this study showed that colonized rats developed antibody against the pathogen and exhibited maxillary bone loss as seen in humans diagnosed with LAP.…”

Section: Discussionsupporting

confidence: 91%

“…We found previously that the wild-type adherent clinical isolate CU1000N Rif was able to colonize the oral cavities of rats (2). Bacteria could be recovered up to 7 months after the feeding with inoculated food.…”

Section: Resultsmentioning

confidence: 88%

“…To confirm that the inoculated food was eaten, the mixture was placed on specially designed feeder trays that fit over the bedding in the cages. We modified the trays used in our previous study (2) so that they were partially disposable. Trays were made from 21.5-cm ϫ 43-cm ϫ 0.6-cm sheets of poly(vinyl chloride) foam plastic with corners rounded so that they would fit inside of the cage and rest on the bedding.…”

Section: Methodsmentioning

confidence: 99%

“…Ideally this is accomplished by comparing disease provoked by a wild-type isolate to that of an isolate lacking or harboring a mutation in a putative virulence factor. This study utilizes a rat model that our group has developed for colonization and persistence of the human pathogen Actinobacillus actinomycetemcomitans (2). In the current study we compare wild-type and isogenic mutant strains of A. actinomycetemcomitans and the relationship of these strains to bone loss and periodontal disease.…”

mentioning

confidence: 99%

“…Clinical isolates also autoaggregate and produce bundled pili that mediate nonspecific adherence (16)(17)(18)(19). The tight-adherence phenotype is thought to be important for colonization of host surfaces, and recently we reported that an adherent clinical isolate was able to colonize, survive, and persist in the oral cavity of rats (2). Using random transposon mutagenesis, we recently identified a tightadherence (tad) locus that contains 14 genes ( flp-1-flp-2-tadVrcpCAB-tadZABCDEFG), of which at least 12 are essential for tight nonspecific adherence, autoaggregation, and pili formation (16,20).…”

mentioning

confidence: 99%

See 4 more Smart Citations

Tight-adherence genes of Actinobacillus actinomycetemcomitans are required for virulence in a rat model

Schreiner

Sinatra

Kaplan

et al. 2003

Proc. Natl. Acad. Sci. U.S.A.

151

165

View full text Add to dashboard Cite

Actinobacillus actinomycetemcomitans is a Gram-negative coccobacillus that has been associated with localized aggressive periodontitis and infections of the heart, brain, and urinary tract. Wild-type clinical isolates have the remarkable ability to adhere tenaciously and nonspecifically to solid surfaces such as glass, plastic, and hydroxyapatite. Adherence by A. actinomycetemcomitans is mediated by the tight-adherence (tad) gene locus, which consists of 14 genes (flp-1-flp-2-tadV-rcpCAB-tadZABCDEFG). All but 2 of the genes have been shown to be required for the secretion and assembly of long, bundled Flp1 fibrils. To test whether the tad locus is required for colonization and disease, we developed a rat model for periodontal disease. To mimic the natural route of infection, Sprague-Dawley rats were inoculated orally by adding bacteria directly to their food for 8 days. After inoculation with wild-type or mutant strains defective in adherence (flp-1 and tadA), the rats were assessed for colonization of the oral cavity and pathogenesis. Wild-type A. actinomycetemcomitans was able to colonize and persist for at least 12 weeks in the oral cavity, elicit a humoral immune response, and cause significant bone loss in rats. In contrast, rats fed flp-1 or tadA mutant strains showed no bone loss and their immune responses were indistinguishable from those of the uninoculated controls. These results demonstrate the critical importance of the tad locus in the colonization and pathogenesis of A. actinomycetemcomitans. nonspecific adherence ͉ tad genes ͉ pathogenesis ͉ localized juvenile periodontitis

show abstract

Section: Discussionsupporting

confidence: 91%

Section: Resultsmentioning

confidence: 88%

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%