Cell surface hydrophobicity of dental plaque microorganisms in situ

The cell surface hydrophobicity of bacteria obtained directly from human tooth surfaces was assayed by measuring their adherence to liquid hydrocarbons. Fresh samples of supragingival dental plaque were washed and dispersed in buffer. Adherence of the plaque microorganisms to hexadecane, octane, and xylene was tested turbidimetrically and by direct microscopic observation. The results clearly show that the vast majority of bacteria comprising dental plaque exhibit pronounced cell surface hydrophobicity. These data support the hypothesis that hydrophobic interactions play a major role in mediating bacterial adherence on tooth surfaces.