Detection of Porphyromonas gingivalis and Simplexvirus in saliva and plaque

Chronic inflammatory periodontal diseases are some of the most widespread bacterial diseases affecting mankind and adult periodontitis is the most frequent type. Objectives: the aims at present were to detect P. gingivalis and herpesvirus, especially genus Simplexvirus(HSV), in saliva and subgingival plaque from 76 periodontitis patients (PE group) and 40 healthy gingival individuals (Control group) and to investigate a putative viral-bacterial association. Methods: two ml of saliva were collected from each individual into a container chilled over ice. Sterile paper points were inserted into each pocket or gingival crevice and pooled into a vial containing VMGA-III transport medium. Samples of bacterial plaque were mechanically dispersed, diluted and plated on Brucella agar, supplemented with 5% defibrinated sheep blood, hemin and menadion for P. gingivalis isolation. Representative colonies were presumptively identified by phenotypic properties. For herpesvirus detection, aliquots of saliva and plaque were diluted in PBS, and viral DNA extracted by using Trizol. Herpesvirus was detected by PCR based on the recognition of the polymerase gene sequence. Results: P. gingivalis was found in 15.8% of the patients in PE group and in 5% of the individuals in Control group. In PE group, herpesvirus was detected in plaques (40.8%) and saliva (78.7%). HSV were identified in subgingival plaque and saliva, in 54.8% and 36.7% of the samples, respectively. In Control group, herpesvirus was found in plaque in 67.5% of the individuals and in saliva in 55%. HSV were detected only in saliva (36.7%). Co-infection of P. gingivalis and herpesvirus in subgingival plaque was observed in PE group (9.21%) and in Control group (2.5%). P. gingivalis and HSV were simultaneously detected only in PE group (12.9%). Conclusion: Beside Pg, herpesvirus is possibly an enhancer factor for periodontitis. Further studies are needed to determine the mechanisms by which herpesviruses cooperate in periodontal diseases.