Aggregatibacter actinomycetemcomitans colonization and persistence in a primate model

Significance Aggregatibacter actinomycetemcomitans , a microorganism associated with aggressive periodontitis, can result in tooth loss and systemic complications. The hyperleukotoxin-producing A. actinomycetemcomitans strain demonstrates up-regulation of attachment genes, permitting it to attach better than the wild-type strain in competition with commensal bacteria for space on tooth surfaces. Further, the availability of lactate provided by streptococci and other members of the indigenous plaque microbiota consorting with A. actinomycetemcomitans reduces its competition for glucose as a main carbon source and assists already-attached strains in growth and persistence in the developing plaque biofilm. Data derived from in vivo and in vitro studies illustrate functional strategies that allow A. actinomycetemcomitans to colonize and survive in the competitive and stressful environment of the oral cavity.