Aggregatibacter actinomycetemcomitans (Aa) in Dental Plaque of Greek Children. Prevalence, Serotype Distribution and Transmission between Mothers and Children

Background: Aggregatibacter actinomycetemcomitans (Aa), a member of the normal oral flora, is also implicated as a pathogen in periodontitis. Some serotypes and clones are more often detected in aggressive periodontitis forms and early colonization of the mouth by this bacterium is thought to increase the risk for disease development. To examine the extent of Aa transmission from mothers to their children and to study the prevalence of Aa and the distribution of its serotypes in dental plaque from Greek children. Methods and Findings: Samples of supragingival plaque were collected both from 108 children aged 5-12 years and their 83 mothers and cultured on agar media. Isolates of Aa from the cultures were characterized by biochemical and molecular techniques. Aa was found in four mother/child pairs. In three of these pairs, the isolates from the child and the mother exhibited the same genotype. Aa was detected in 12% of children and 23% of mothers. The isolated strains from children belonged to serotypes a (17%), b (50%), and c (33%). In mothers, the serotype distribution was 21% a, 37% b, 32% c, 5% e, and 5% f. None of the Aa isolates belonged to the highly leukotoxic JP2 clone. Conclusion: The prevalence of Aa and its serotype distribution pattern in Greek children are similar with those reported for other Caucasians. Aa occurrence in dental plaque of children and their mothers infrequently coincides. Received: Sep 25, 2015, Accepted: Oct 28, 2015, Published: Nov 07, 2015