The Assessment of the Association Between Herpesviruses and Subgingival Bacterial Plaque by Real-time PCR Analysis

This study used a real-time PCR analysis to determine possible correlations between periodontal presence of human cytomegalovirus, Epstein-Barr virus and various putative parodontopathogenic bacteria. The study included 18 patients (aged 18-38 years) with aggressive periodontitis, 12 patients (ages 37 to 62) with chronic periodontitis and 30 periodontally healthy subjects (aged 21-54 years). Clinical periodontal evaluation included plaque index, gingival index, percentage of bleeding on probing sites, and probing depth. In each patient, a subgingival bacterial plaque sample was obtained from the deepest periodontal pocket. The real-time fluorogenic PCR detection system was used to determine the number of infectious agents. Human cytomegalovirus was detected in 17 sites with periodontal lesions and in two healthy periodontal sites, and the Epstein-Barr virus was detected in 19 sites with periodontal lesions and in 3 normal periodontal sites. Positive correlations were found between human cytomegalovirus and P. gingivalis, T. forsythia and C. rectus. The Epstein-Barr virus positively correlated with P. gingivalis and T. forsythia. Unfavorable changes in environmental exposure or alteration of the immune system genes can periodically suppress the host�s defence against periodontal aggression, which can then result in reactivation of resident herpesviruses and increased pro-inflammatory mediators followed by an increase in pathogenic bacteria.