Genetic similarity of subgingival yeasts in marginal periodontitis

Yeasts in periodontal pockets have been reported at a frequency of 15-21%. However, the genetic relatedness of oral yeasts in patients with marginal periodontitis (MP) is not clear. Objective: Assess genetic similarity of yeasts from periodontal pockets of patients with MP and from gingival crevices in individuals with oral health (OH). Materials and methods: Microbiological samples were collected from 70 MP patients and 45 OH subjects. Random Amplification of Polymorphic DNA (RAPD) and the Dendron computer-assisted program were applied for estimation of genetic similarity of yeasts. Results: Yeasts were detected from subgingival areas in 20.0% of MP patients and from gingival crevices in 28.9% of OH subjects. Totally, 33 strains were found in periodontal pockets with 29 strains distributing in 11 genetic clusters at SAB of 79%. 22 strains were found in healthy gingival crevices with 18 strains distributing in 11 genetic clusters at SAB of 79%. In the pooled dendrogram, yeasts from subgingival areas of the two groups only shared one common cluster. Conclusions: Subgingival yeasts were rather commonly detected in both MP patients and OH subjects. The yeasts found were genetically heterogeneous in both groups. Subgingival yeasts of MP and OH groups shared a low genetic similarity.