Relationship between Porphyromonas gingivalis, Epstein-Barr virus infection and reactivation in periodontitis.

The aim of this study was to assess the relationship-between Porphyromonas gingivalis, Epstein-Barr virus (EBV) infection and reactivation in periodontitis using real-time PCR. The mean proportion of P. gingivalis cells to total bacterial cells in the saliva from EBV-positive periodontitis patients was significantly higher than that in saliva from EBV-negative patients. An EBV-positive B-cell line was used to determine whether P. gingivalis sonicate induced reactivation of EBV, using real-time PCR to measure the virus genome in the culture medium. A significant increase in EBV numbers was observed after the stimulation with P. gingivalis sonicate. These findings suggest that the interaction between EBV and P. gingivalis is bi-directional, with EBV reactivation suppressing host defenses and permitting overgrowth of P. gingivalis, and P. gingivalis having the potential to induce EBV reactivation.