TRANSMISSION OF ACTINOBACILLUS-ACTINOMYCETEMCOMITANS IN FAMILIES OF ADULT PERIODONTITIS PATIENTS

At present Actinobacillus actinomycetemcomitans is regarded as an impo rtant microorganism in the etiology of some forms of periodontitis. Th e purpose of the present investigation was to study the number of Rest riction Endonuclease Analysis (REA)-types present in the oral cavity o f A. actinomycetemcomitans positive subjects and to study the possibil ity of transmission of A. actinomycetemcomitans within families of adu lt periodontitis patients. DNA of A. actinomycetemcomitans isolates wa s digested with a combination of the restriction endonucleases PstI an d BamHI, after which the DNA fragments were separated by agarose gelel ectrophoresis. To study the number of REA-types, multiple A. actinomyc etemcomitans isolates obtained from 8 different sites in the oral cavi ty of five subjects were typed. The results showed that in most cases only one REA-type is present. In the 13 families investigated in 4 of the 26 children (15%) and in 1 of the 13 spouses (8%) of the adult per iodontitis patients an indistinguishable REA-type was found within the families. This suggests that also in the case of adult periodontitis transmission of A. actinomycetemcomitans is possible, but does not see m to occur easily.