A ggregatibacter actinomycetemcomitans serotypes, the JP 2 clone and cytolethal distending toxin genes in a T hai population

• Published in: Journal of clinical periodontology Vol. 39; no. 6; pp. 519 - 525
• Main Authors: Bandhaya, Panwadee, Saraithong, Prakaimuk, Likittanasombat, Khanchit, Hengprasith, Bunlue, Torrungruang, Kitti
• Format: Journal Article
• Language: English
• Published: 01.06.2012
• ISSN: 0303-6979; 1600-051X
• DOI: 10.1111/j.1600-051X.2012.01871.x

Abstract Aim To examine the genetic diversity of A ggregatibacter actinomycetemcomitans in T hai adults. Materials and Methods Subgingival plaque samples from 453 subjects were analysed for A . actinomycetemcomitans serotypes, the presence of the high leukotoxin‐producing JP 2 clone and cytolethal distending toxin genes ( cdt ABC ) using the polymerase chain reaction technique. In subjects who were positive for cdt ABC , restriction fragment length polymorphism analysis was used to identify a single nucleotide polymorphism ( SNP ) in the cdt B gene at amino acid position 281. The extent and severity of periodontal disease were compared between subjects harbouring different A . actinomycetemcomitans genotypes. Results Eighty six subjects (19%) were positive for A . actinomycetemcomitans . The JP 2 clone was not detected. Serotype c was the most prevalent (57%), followed by serotypes a (33%) and b (7%). Among A . actinomycetemcomitans ‐positive subjects, 27% were positive for cdt ABC . All cdt ABC ‐positive subjects possessed the SNP in the cdt B , which is involved with increased toxin activity. The presence of A . actinomycetemcomitans , but not a specific genotype, was significantly related to increased probing depth and periodontal attachment loss. Conclusions Our results confirm the previous findings that genotype distribution of A . actinomycetemcomitans varies between ethnic groups. However, no clear relationship between a specific genotype and periodontal conditions was observed.