A panel of probes detects DNA polymorphisms in human and non-human primate isolates of a periodontal pathogen, Actinobacillus actinomycetemcomitans

A panel of five DNA probes has been developed for use in genetic epidemiologic analysis of Actinobacillus actinomycetemcomitans, a bacterium associated with periodontal disease. Restriction fragment length polymorphism profiles were assessed using random genomic probes as well as probes for genes encoding potential virulence factors. These genotypes were compared with serotype and other phenotypic markers. Genotype was shown to be more stable than the phenotypic markers and should prove useful in epidemiological studies of periodontal disease. In addition, the use of a panel of probes has the advantage of being able to distinguish between the occurrence of a new isolate as opposed to a mutation in a strain already characterized. The panel of probes was tested on 35 isolates from humans, 18 isolates from monkeys, and two isolates from a baboon. The genetic probes revealed significant genetic diversity among the A. actinomycetemcomitans isolates. Importantly, most human isolates from an individual genotyped identically, whereas most isolates cultured from a given monkey were different, suggesting that one should exercise caution in comparison of A. actinomycetemcomitans infections in human and non-human primates.