Java project on periodontal diseases: serotype distribution of Aggregatibacter actinomycetemcomitans and serotype dynamics over an 8-year period

Objective: To investigate the serotype distribution and stability of Aggregatibacter actinomycetemcomitans over an 8-year period in untreated Indonesian subjects. Material and Methods: Clinical periodontal status and the presence of A. actinomycetemcomitans were established in 1994 and 2002 in 107 subjects from an Indonesian tea estate deprived from dental care. On an average, 3.6 isolates per patient were subcultured and serotyped using specific PCR reactions. Results: In 1994, the predominant serotype was b (53.7%), whereas a and c occurred in 17.1% and 14.6% of the subjects, respectively. In 2002, a reduction in serotypes a (7.5%) and b (30.2%) occurred. Serotypes c and e increased in prevalence from 14.6% to 35.8% and 2.4% to 9.4%, respectively. Multiple serotypes were found in 12.2% in 1994 and 17% in 2002. From 24 subjects who were positive at both time points, 14 (58.3%) had the same serotype, whereas in 10 subjects (41.7%), a different serotype was found. Mean clinical attachment loss had increased from 0.74mm in 1994 to 1.96mm in 2002 but could not be related to subgingival presence of A. actinomycetemcomitans. Conclusions: A. actinomycetemcomitans serotypes distribution in Indonesian young adults shifts from predominantly serotype b to a more equal prevalence of serotypes b and c. This shift suggests an opportunistic character of A. actinomycetemcomitans