Antibacterial and Antibiofilm Profiles of Thymus vulgaris Essential Oil on Clinically Isolated Porphyromonas Gingivalis and Prevotella intermedia: An In Vitro Study

Abstract

Objective: To investigate the antibacterial and antibiofilm effect of the essential oil extracted from Thymus vulgaris (TV) against clinically isolated Porphyromonas gingivalis (P. gingivalis) and Prevotella intermedia (P. intermedia). 
 Methods: Subgingival plaque samples were collected from periodontitis patients with a probing pocket depth of at least 6mm. Conventional microbiological tests and molecular techniques were used to isolate and confirm P. intermedia. In addition, previously isolated P gingivalis was obtained from the microbiology department of the college of dentistry, Sulaimani University. The hydrodistillation method was used for the extraction of the essential oil. The antibacterial activity of TV against the confirmed clinical strains has been determined by disc diffusion and broth dilution methods to determine the minimum inhibitory (MIC) and bactericidal (MBC) concentrations. In addition, the antibiofilm activity of the essential oils was evaluated by a qualitative tube method. 
 Results: The essential oil extracted from TV revealed comparable antibacterial activity with inhibition zones ranging from 9.55±0.30mm to 15.85±0.30mm for P. gingivalis and 10.55±0.25mm to 16.85±0.40mm for P. intermedia. The MIC of the tested oil were 1.56μL/mL and 0.78μL/mL, while the MBC were 3.125μL/mL and 1.56 μL/mL against P. gingivalis and P. intermedia, respectively. TV essential oil showed moderate and robust antibiofilm activity against P. gingivalis and P. intermedia. 
 Conclusions: TV essential oil showed antibacterial and antibiofilm activity against clinically isolated P. gingivalis and P. intermedia. Further studies should focus on using TV essential oil as an adjunct to periodontal therapy.