Effect of chlorhexidine and phenoxyethanol on cell surface hydrophobicity of Gram-positive and Gram-negative bacteria

Abstract

The surfaces of mutants of Escherichia coli and Pseudomonas aeruginosa were markedly more hydrophobic than the corresponding wild types, as were the latter when the organisms were pre-treated with chlorhexidine diacetate (CHA) or phenoxyethanol (POE). A combination of CHA and POE demonstrated that only at higher concentrations was there a marked effect on hydrophobicity compared with that of either drug used alone. The three methods used to determine hydrophobicity correlated well as long as constant conditions were employed.