Actinobacillus actinomycetemcomitans is a member of the family Pasteurellaceae and a major causative agent of periodontitis. While several genera from this family are known to be competent for transformation, A. actinomycetemcomitans has yet to be fully characterized. Here we show that the competence of A. actinomycetemcomitans is remarkably similar to that of Haemophilus influenzae. In additio...

Actinobacillus actinomycetemcomitans has been shown to produce a soluble cytotoxic factor(s) distinct from leukotoxin. We have identified in A. actinomycetemcomitans Y4 a cluster of genes encoding a cytolethal distending toxin (CDT). This new member of the CDT family is similar to the CDT produced by Haemophilus ducreyi. The CDT from A. actinomycetemcomitans was produced in Escherichia coli and...

We previously reported that the serotype b antigen of Actinobacillus actinomycetemcomitans is a constituent of the polysaccharide region of lipopolysaccharide (LPS) and contains significant amount of the neutral sugars rhamnose and fucose (M. Wilson and R. Schifferle, Infect. Immun. 59:1544-1551, 1991). In the present study, we determined the structure of the O antigen of A. actinomycetemcomita...

OBJECTIVE This study characterized Actinobacillus actinomycetemcomitans isolates from young Chinese aggressive periodontitis patients. METHODS Subgingival plaque samples (two/subject) were collected from diseased subjects < 25 years old (n = 9, mean age 21.1 +/- 1.6 years) and age-matched periodontitis-free controls (n = 47, mean age 22.0 +/- 1.1 years). Selective and anaerobic culture were u...

Actinobacillus actinomycetemcomitans is an oral pathogen that causes aggressive periodontitis as well as sometimes life-threatening, extra-oral infections. Iron regulation is thought to be important in the pathogenesis of A. actinomycetemcomitans infections and, consistent with this hypothesis, the fur gene has recently been identified and characterized in A. actinomycetemcomitans. In this stud...

Sera of localized juvenile periodontitis (LJP) patients colonized by Actinobacillus actinomycetemcomitans serotype b often contain markedly elevated levels of immunoglobulin G (IgG) antibodies to serospecific determinants in the O polysaccharide of lipopolysaccharide (LPS), as well as to outer membrane proteins of this species. IgG antibodies in LJP sera are known to opsonize A. actinomycetemco...

A. actinomycetemcomitans, B. forsythus, P. gingivalis, C. rectus, E. corrodens, P. intermedia, F. nucleatum, and T. denticola were identified from subgingival plaque from 50 periodontal patients and 50 healthy subjects. PCR products from each species showed a specific band and could be used to identify periodontal organisms from clinical specimens. Identical negative or positive results between...

OBJECTIVES To test the antimicrobial sensitivity of two periodontal pathogens to a panel of five orally administrable antibiotics in periodontal disease. STUDY DESIGN A total of 69 isolates of Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis were processed using culture and biochemical tests. Selected colonies of A. actinomycetemcomitans and P. gingivalis were used to evalua...

For decades, Aggregatibacter actinomycetemcomitans has been associated with aggressive forms of periodontitis in adolescents. In the middle of the 1990s, a specific JP2 clone of A. actinomycetemcomitans, belonging to the cluster of serotype b strains of A. actinomycetemcomitans and having a number of other characteristics, was found to be strongly associated with aggressive forms of periodontit...

We previously reported that infection with the periodontopathic bacterium Actinobacillus actinomycetemcomitans induced apoptosis in a mouse macrophage cell line J774.1. In the present study, we examined the involvement of cytochrome c and caspases in the induction of apoptosis in A. actinomycetemcomitans-infected J774.1 cells. Following infection, the expression levels of cytochrome c, and clea...