Isolation and genotyping of black-pigmented anaerobes from periodontal sites of HIV-positive and non-infected subjects in Thailand

Background, aims: The aims of this study were to investigate the prevalence of periodontitis, the prevalence of black-pigmented anaerobes and the geno types of Porphyromonas gingivalis and Prevotella intermedia present in HIV- infected and control subjects in a heterosexual Thai population. Method: 50 AIDS patients and 50 control subjects were included in the study . Their periodontal condition was examined by assessment of bleeding on pro bing, attachment loss and probing depth, and presence of erythema around 6 teeth (16, 21, 24, 36, 41, 44). Subgingival plaque was collected from the m esiobuccal sites of these teeth and was cultured anaerobically for black-pi gmented bacteria. Species were characterised using biochemical profiles and total protein profiles. Genotyping of each isolate was performed using PCR techniques. Results: There was little clinical evidence of HIV-associated periodontitis in the HIV-positive subjects and no difference was found in the prevalence or genotype distribution of black-pigmented anaerobes between HIV-infected and control subjects. Conclusions: These data suggest lack of severe periodontal destruction due to HIV-infection in Thailand and that these subjects are not colonised by m ore numerous or characteristic clones of certain putative periodontal patho gens.