Inhibition of Porphyromonas gingivalis biofilm by oxantel

Abstract

Porphyromonas gingivalis is a major pathogen of chronic periodontitis and exists in a biofilm on the surface of the tooth root. Oxantel, a cholinergic anthelmintic and fumarate reductase inhibitor, significantly inhibited biofilm formation by P. gingivalis and disrupted established biofilms at concentrations below its MIC against planktonic cells. Oxantel was more effective against P. gingivalis in biofilm than metronidazole, a commonly used antibiotic for periodontitis.

FIG. 1.

Effects of oxantel on P. gingivalis ATCC 33277 biofilm formation and growth in a 96-well microtiter static assay. The biofilms were quantified at 24 h, and the results represent the means of 12 replicates. *, significantly different (P < 0.001) from controls (0 and 0 + dimethyl sulfoxide [DMSO]), evaluated using a one-way classification analysis of variance with a Scheffe multiple comparison.

FIG. 2.

CLSM images of a representative section of a P. gingivalis ATCC 33277 18-h biofilm grown in a flow cell and stained with BacLight. Horizontal (x-y) optodigital sections, each 2 μm thick over the entire thickness of the biofilm (z), were imaged using a 63× objective at 512 by 512 pixels (0.28 μm per pixel), with each frame at 143.86 μm (x) by 143.86 μm (y).

FIG. 3.

CLSM images of a representative section of a P. gingivalis ATCC 33277 18-h biofilm grown in a flow cell, treated with 125 μM oxantel, and then stained with BacLight. Horizontal (x-y) optodigital sections, each 2 μm thick over the entire thickness of the biofilm (z), were imaged using a 63× objective at 512 by 512 pixels (0.28 μm per pixel), with each frame at 143.86 μm (x) by 143.86 μm (y).