OBJECTIVE The aim of this study was to investigate the association between angiographically verified coronary artery disease (CAD) and salivary levels of four major periodontal pathogens. METHODS The study population (n = 492) was composed of 179 (36.4%) patients with stable CAD, 166 (33.7%) with acute coronary syndrome (ACS), and 119 (24.2%) showing no pathological findings by coronary angio...

The leukotoxin produced by Actinobacillus actinomycetemcomitans has been implicated in the etiology of localized juvenile periodontitis. To initiate a genetic analysis into the role of this protein in disease, we have cloned its gene, lktA. We now present the complete nucleotide sequence of the lktA gene from A. actinomycetemcomitans. When the deduced amino acid sequence of the leukotoxin prote...

Aggregatibacter actinomycetemcomitans is an oral and systemic pathogen associated with aggressive forms of periodontitis and with endocarditis. We recently demonstrated that outer membrane vesicles (OMVs) disseminated by A. actinomycetemcomitans could deliver multiple proteins, including biologically active cytolethal distending toxin (CDT), into the cytosol of HeLa cells and human gingival fib...

BACKGROUND An investigation of the mechanisms underlying the production of inflammatory cytokines through the stimulation of microorganisms on gingival epithelial cells may provide insights into the pathogenesis of the initiation of periodontitis. Lipid rafts, microdomains in the cell membrane, include a large number of receptors, and are centrally involved in signal transduction. We herein exa...

BACKGROUND Evidence to date shows that mast cells play a critical role in immune defenses against infectious agents, but there have been no reports about involvement of these cells in eliminating periodontopathogens. In this study, the phagocytic ability of mast cells against Aggregatibacter actinomycetemcomitans compared with macrophages is evaluated. METHODS In vitro phagocytic assays were ...

98021 Actinobacillus actinomycetemcomitans is a Gram-negative coccobacillus which can cause certain severe extra-oral infections as well as forms of human periodontal disease such as localized juvenile periodontitis. In contrast to many prokaryotic and eukary-otic species which exhibit an intact 23S ribosomal RNA (rRNA) molecule, examination of six A. actinomycetemcomitans strains-including thr...

The JP2 clone of Actinobacillus actinomycetemcomitans is associated with early-onset periodontitis in certain ethnic populations of African origin. Here, we describe and evaluate a set of primers for PCR to assay for the presence of A. actinomycetemcomitans and to discriminate between JP2-like strains and other genotypes in subgingival plaque samples.

The periopathogen Aggregatibacter actinomycetemcomitans is associated with aggressive periodontitis, a severe disease that causes rapid tooth loss among young adolescents. A. actinomycetemcomitans produce and secrete leukotoxin a pore forming protein which causes death of human polymorphonuclear leukocytes (PMNs) such as neutrophils. PMNs are the most abundant leukocyte and have important defen...

BACKGROUND Aggregatibacter actinomycetemcomitans is genetically heterogeneous and comprises distinct clonal lineages that may have different virulence potentials. However, limited information of the strain-to-strain genomic variations is available. METHODOLOGY/PRINCIPAL FINDINGS The genome sequences of 11 A. actinomycetemcomitans strains (serotypes a-f) were generated de novo, annotated and c...

LuxS is responsible for the production of autoinducer 2 (AI-2), which functions in Vibrio harveyi as a quorum-sensing signal that controls the cell density-dependent expression of the lux operon. In nonluminescent organisms, the physiologic role of AI-2 is not clear. We report that inactivation of luxS in Actinobacillus actinomycetemcomitans JP2 results in reduced growth of the mutant, but not ...