Prevalence of Porphyromonas gingivalis and Bacteroides forsythus in chronic Periodontitis by Multiplex PCR

Periodontitis is a common inflammatory and infectious disease which destroys the supporting structure of the teeth. Recent studies show that periodontal infection significantly increases the risk of some systemic diseases. It is generally accepted that bacterial species notably Porphyromonas gingivalis and Bacteroides forsythus are highly associated with periodontium. Molecular methods such as Multiplex PCR seem to be more sensitive and faster. Multiplex PCR alone can lower the limit of bacterial detection. Several pathogens can be detected simultaneously by this method. The Subgingival plaque samples from 61 patients including 34 women and 27 men in the age range of 24-69 years and an average age of 43 suffering from chronic periodontitis with probing depth of PD6, and from 40 periodontally healthy controls including 22 women and 18 men in the age range of 21-69 years and an average age of 41.35 were collected by sterile curette. In this study, two species-specific forward primers were used in combination with a single reverse primer. The sample's DNA was extracted and Multiplex PCR was administered. Porphyromonas gingivalis was detected in 51 samples (83.61%) and 16 samples (40%) of the chronic periodontitis patients and the healthy subjects respectively. Moreover, Bacteroides forsythus was detected in 32 samples (52.50%) of the chronic periodontitis patients but it was not detected in any of the samples from the healthy group. P. gingivalis and B. forsythus can be simultaneously detected using Multiplex PCR. The present data suggest that P. gingivalis is a more important factor in the etiology of chronic periodontitis. Further studies are needed to determine the spectrum of pathogenicity of the disease and effective management of diagnosis and treatment in order to decrease the risk of periodontal complications such as systemic infections.