Presence of Aggregatibacter actinomycetemcomitans in Young Children

Objectives: This study determined the prevalence of oral Aggregetibacter actinomycetemcomitans (Aa) in children with a primary dentition from a Newark, NJ population. Secondarily, colonization site and Aa serotype distribution was examined. Methods: 98 children with primary dentition (median age 39 ± 17 months ) were sampled from the dorsum of tongue, buccal epithelium and supragingival plaque from the most distal tooth in each quadrant via toothpick and swabs. Samples were grown on Aa selective agar. Aa colonies recovered from samples were analyzed by PCR for serotype (a-f) and leukotoxin promoter type (JP2 or 652 type) and agarose gel electrophoresis. Results: 15 of 98 children were Aa positive (15.3)%. 18 % of African-American children and 14 % of Hispanic children were found with Aa. The primary site of colonization was the buccal mucosa (n = 13), followed by plaque (n=11) and tongue (n=8). No subject was found to harbor Aa on the tongue alone. The most commonly found serotypes were c (n=6), followed by b (n=5) and a (n=4). No statistically significant difference in the distribution of serotype with respect to gender, age or race was found by Chi-square analysis, although a younger subgroup (< 36 months) had a prevalence of colonization of 10% versus 19% for an older (>36 month) subgroup. These prevalences were comparable to those reported for Newark 11-17 year olds (Fine, 2007). All Aa strains found were of the 652 leukotoxin promoter type. Conclusions: The prevalence of Aa in this young population was comparable to that in 11-17 year olds from the Newark public school system, which suggests Aa colonization is stable between early childhood and adolescence. Sampling the buccal epithelium and supragingival plaque alone is sufficient to provide a useful test for Aa carriage in young children.