Effect of chlorhexidine on human oral streptococci.

The article comments on the effect of chlorhexidine on human oral streptococci. In an experiment the authors have observed that bacteria with reduced sensitivity to chlorhexidine gluconate accumulate in saliva after long term use of 2.2 mM chlorhexidinc as a mouthwash. This indicates an effect of chlorhexidine on the cell wall of the control strains, either by releasing cell wall material and/or by causing a leakage of intracellular material. The experiments do not allow a distinction between the two possibilities, but support the indications from the azocarmine B staining experiments that chlorhexidine changes the surface properties of the microorganisms.