RESUMEN
AIM: to investigate the distribution of Aggregatibacter actinomycetemcomitans serotypes and the prevalence of the JP2 clone in subgingival samples of Greek subjects. MATERIALS AND METHODS: two hundred and twenty eight subjects participated in the present study. Each contributed with one pooled subgingival sample from the mesiobuccal surface of the four first molars. Samples were analysed using polymerase chain reaction for five serotypes of A. actinomycetemcomitans and the JP2 clone, using primers and conditions described previously. Subjects were stratified according to periodontal status (untreated periodontitis, non-periodontitis and periodontitis patients receiving supportive treatment). Comparisons between and within groups were performed by applying non-parametric tests (Kruskall-Wallis, Pearson χ(2) , z-test with Bonferroni's corrections and Kramer's V-test) at p=0.05 level. RESULTS: a. actinomycetemcomitans was detected statistically more frequently in untreated patients (27.5%) compared with the other two groups (11.7% for non-periodontitis and 10% for periodontitis patients receiving supportive treatment). No statistical differences were observed concerning the distribution of serotypes among groups (z-test with Bonferroni's corrections p>0.05). Serotype c was more predominant within the periodontally diseased groups (Kramer's V-test p<0.05). The JP2 clone was not detected. CONCLUSIONS: a. actinomycetemcomitans serotype b was not statistically correlated with periodontal disease in the investigated sample and the utility of microbiological testing before antimicrobial administration is emphasized.