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The complete 2,343,479-bp genome sequence of the gram-negative, pathogenic oral bacterium Porphyromonas gingivalis strain W83, a major contributor to periodontal disease, was determined. Whole-genome comparative analysis with other available complete genome sequences confirms the close relationship between the Cytophaga-Flavobacteria-Bacteroides (CFB)(More)
Gingival epithelial cells are the primary barrier to infection by periodontal pathogens. The production of chemotactic cytokines, including interleukin-8 (IL-8), is one mechanism the host uses in response to infection. In this study it was found that both gingival and oral epithelial cells produced IL-8, but after infection with the periodontal pathogen(More)
Porphyromonas gingivalis is one of the principal organisms associated with adult periodontitis. Bacterial surface proteins such as fimbriae and gingipain hemagglutinin domains have been implicated as adhesins that actuate colonization of epithelium lining the gingival sulcus. We investigated the genetics of P. gingivalis adhesion to monolayers of epithelial(More)
Little is known about how Porphyromonas gingivalis, a Gram-negative oral anaerobe, senses environmental changes, and how such information is transmitted to the cell. The production of P. gingivalis surface fimbriae is regulated by FimS-FimR, a two component signal transduction system. Expression of fimA, encoding the fimbrilin protein subunit of fimbriae,(More)
The virulence of the dental caries pathogen Streptococcus mutans relies in part on the sucrose-dependent synthesis of and interaction with glucan, a major component of the extracellular matrix of tooth biofilms. However, the mechanisms by which secreted and/or cell-associated glucan-binding proteins (Gbps) produced by S. mutans participate in biofilm growth(More)
Streptococcus mutans is the main pathogenic agent of dental caries. Glucosyltransferases (Gtfs) produced by these bacteria are important virulence factors because they catalyze the extracellular synthesis of glucans that are necessary for bacterial accumulation in the dental biofilm. The diversity of GtfB and GtfC isozymes was analyzed in 44 genotypes of S.(More)
A mutant of Rhizobium meliloti selected as unable to grow on L-arabinose also failed to grow on acetate or pyruvate. It grew, but slower than the parental strain, on many other carbon sources. Assay showed it to lack alpha-ketoglutarate dehydrogenase (kgd) activity, and revertants of normal growth phenotype contained the activity again. Other enzymes of the(More)
Streptococcus mutans strains were isolated from cohorts of Brazilian nursery school children and genotyped by arbitrarily primed PCR and restriction fragment length polymorphism analysis. Of 24 children with two to five S. mutans isolates, 29% carried two or more genotypes. The presence of matching genotypes of S. mutans among children attending one nursery(More)
Porphyromonas gingivalis is a Gram-negative, black pigmented oral anaerobe associated with adult periodontitis. The adherence of the bacterium to junctional epithelial cells is the first step in infection and colonization. The molecular mechanisms and genetics of colonization are, as yet, not well understood, although it has been demonstrated that P.(More)
Periodontitis is a biofilm-mediated disease. Porphyromonas gingivalis is an obligate anaerobe consistently associated with severe manifestations of this disease. As an opportunistic pathogen, the ability to proliferate within and disseminate from subgingival biofilm (plaque) is central to its virulence. Here, we report the isolation of a P. gingivalis(More)