APAH POLYMORPHISM IN CLINICAL ACTINOBACILLUS-ACTINOMYCETEMCOMITANS ISOLATES

In the present study the apaH polymorphism in clinical A. actinomycete mcomitans isolates were investigated in relation to their serotype and periodontal status of the donor subjects. The material included 122 A . actinomycetemcomitans isolates representing serotypes a-e from 103 p eriodontally healthy and diseased subjects. The apaH polymorphism was investigated by both restriction analysis of the specific PCR amplific ation product and also by sequencing of PCR amplification products fro m selected clinical isolates. An apaH specific PCR amplification produ ct was obtained from all isolates but the restriction patterns of the amplification products varied. Serotype c and genogroup 2 within serot ype e formed genetically distinct groups, whereas isolates of serotype a, b, d and genogroup 1 within serotype e could not be separated from each other based on the apaH restriction analysis. No relation betwee n the restriction pattern of apaH and the periodontal status of the in dividuals was detected. These results indicate that serotype c isolate s form a uniformly distinct group within A. actinomycetemcomitans and that a subpopulation of serotype e isolates clearly diverge from all o ther A. actinomycetemcomitans isolates. (C) 1998 Academic Press.