Detection of the highly leucotoxic JP2 clone of Aggregatibacter actinomycetemcomitans in members of a Caucasian family living in Sweden

P>Background Carriers of the JP2 clone of Aggregatibacter actinomycetemcomitans exhibit an enhanced risk for developing aggressive periodontitis compared with individuals carrying non-JP2 clones. While the JP2 clone is almost exclusively detected among adolescents of African descent, reports on Caucasians colonized with the JP2 clone are remarkably few. Objective The aim of this paper is to report on the history of periodontal disease and microbiological findings in a Caucasian family. Material and Methods A. actinomycetemcomitans and other periodontitis-associated bacterial species in subgingival plaque samples were quantified by conventional culture technique. Leucotoxin promoter typing, serotyping and further characterizations of A. actinomycetemcomitans isolates were performed by PCR. DNA sequencing of the pseudogene, hbpA was performed to determine the origin of the detected JP2 clones. Further, genetically ancestry testing of family members was carried out. Results The JP2 clone was detected in samples from two of the family members, a 33-year-old daughter and her 62-year-old mother. Relationship of their JP2 clones with JP2 clone strains from the Mediterranean area of Africa was indicated. Genotyping confirmed the Caucasian origin of all family members. Conclusions Caucasian JP2 carriers exist and older subjects can carry the JP2 clone of A. actinomycetemcomitans.