CLONAL DIVERSITY OF ACTINOBACILLUS-ACTINOMYCETEMCOMITANS, PORPHYROMONAS-GINGIVALIS AND PREVOTELLA-INTERMEDIA NIGRESCENS IN 2 FAMILIES

To study intra-individual. and intrafamilial clonal diversity of the p utative periodontopathogens Actinobacillus actinomycetemcomitans, Porp hyromonas gingivalis and Prevotella intermedia/nigrescens group, famil y members of two children harbouring these species were investigated. A. actinomycetemcomitans and P. gingivalis isolates were characterized by sero- and ribotyping, while P. intermedia/nigrescens group isolate s were characterized by ribotyping and certain A. actinomycetemcomitan s isolates also by arbitrarily primed polymerase chain reaction. In bo th families, one or both parents were positive for A. actinomycetemcom itans, P. gingivalis and P. intermedia/nigrescens group, whereas sibli ngs harbored only two of the three organisms. None of the subjects har boured more than one ribotype of P. gingivalis, whereas up to three an d four different intra-individual ribotypes of A. actinomycetemcomitan s and P. intermedia/nigrescens, respectively, could be found. Ribotype s from unrelated subjects were unique, but identical ribotypes of A. a ctinomycetemcomitans, P. gingivalis and P. intermedia/nigrescens were detected in both families indicating possible transmission of these sp ecies. Of the 17 different ribotypes found in the children, three sugg ested maternal transmission, two paternal transmission, one ribotype w as shared with the parents, two ribotypes were shared with the sibling s but not with their parents, and nine ribotypes were unique, suggesti ng sources of colonization outside the family. (C) 1996 Academic Press