Comparison of cluster analysis of Porphyromonas gingivalis by arbitrarily primed-polymerase chain reaction between healthy and chronic periodontitis subjects

Introduction: Periodontitis is a chronic destructive inflammatory disease of the oral cavity. The main causative agent is presence of biofilm formed due to different micro-organisms. Among different micro- organisms “red complex” bacteria is known to be the main causative agent in progression of periodontitis. Porphyromonas gingivalis out of the red the complex organism plays a major role in progression of periodontitis. P. gingivalisis present in both in healthy and diseased individuals. The difference in the strains will determine the virulence factor of the organism and also progression of disease. Only few studies have been done showing variation in strains present between healthy and diseased. Aims: To check the difference in heterogeneity of P. gingivalis in chronic periodontitis and healthy individuals through Arbitrarily Primed-PCR (AP-PCR). Materials and Methods: A total of 400 subjects (200 each of chronic periodontitisandhealthy individuals) were included. Sub-gingival plaque was collected in the Reduced transport fluid (RTF) medium and processed at the institutional central research laboratory. Presence of P. gingivalis was, confirmed by culture andphenotypical analysis. Further confirmed cases were processed for PCR after DNA extraction using 16S rRNA. Positive cases of P. gingivalis were subjected for AP-PCR for clonal analysis using the specific 272 primer. Results: In 152(76%) and 98(49%) were confirmed for P. gingivalis in chronic periodontitis and healthy individual respectively by PCR. AP-PCR analysis showed 6 clusters with similarity index in CP and 3 clusters with similarity index in Healthy individuals. Conclusion: The present study showed difference in clusters between chronic periodontitis and healthy individual'sthussuggestive variantin genetic heterogeneity of P. gingivalis strain between healthy and chronic periodontitis. AP- PCR appears to be a promising tool for clonal analysis of P. gingivalis .