Identification of Oral Sites that Harbor Actinobacillus actinomycetemcomitans in Children

Objective: Actinobacillus actinomycetemcomitans (Aa) has been implicated as the cause of Localized Aggressive Periodontitis (LAP). 850 periodontally healthy children ages 11-16 from Newark, NJ were followed every 6-months to determine the relationship of Aa to the onset of LAP. At the initial screening visit we collected buccal epithelial cells (BECs), tongue scrapings and pocket bacteria for detection of Aa and report on results from the screening visit. One aim of the study was to determine the oral colonization sites for Aa found in children susceptible to LAP. Methods: BECs were collected by gently scraping the cheek mucosa with a wooden tongue depressor. Children with pockets >4mm were sampled for Aa with absorbent paperpoints and 425 children had their tongues sampled for Aa. All samples were suspended in buffered saline, and plated on agar selective for Aa. Bacteria recovered from agar were subjected to biochemical and PCR testing for Aa confirmation and specification of Aa serotypes. Results: 116 children harbored Aa (13.6 %). 58 of these were Hispanic. 41% were African American. 88 children (76%) had Aa recovered from BECs. 67 had Aa isolated from pockets and 5 of 425 had Aa on their tongue cells (1.2%). 38% had Aa recovered from BECs only; while 22% had Aa from pocket sites exclusively. Aa was recovered from >98% of subjects if both BECs and pockets were sampled. There was a significant number of Hispanic children who showed the Aa “c” serotype (p >0.01). African American children showed a random distribution of Aa serotypes. Conclusions: Sampling of BECs appears to provide a quick and efficient method for identification of young children who harbor Aa. Sampling of BECs and pockets, when present, permits almost complete recovery of Aa from these children.