The lethal action of 2-phenoxyethanol and its analogues upon Escherichia coli NCTC 5933

Bactericidal activity has been assessed for a number of glycolmonophenyl ethers towards Escherichia coli NCTC 5933, and the action of one analogue, 2-phenoxyethanol, has been studied in greater detail. For this compound the onset of bactericidal activity towards Escherichia coli occurred at concentrations which also induced considerable increases in drug uptake, marked leakage of cytoplasmic constituents, the cellular penetration of N-tolyl-alpha-napthylamine-8-sulphonic acid, and morphological changes consistent with gross membrane damage. However, temperature coefficients of rates of cellular leakage of low molecular weight cytoplasmic constituents, and rates of kill, were markedly different and suggested that the two phenomena were not integrally related, but that each was a consequence of some other action of the drug. Drug levels considerably below those possessing lethal activity, however, promoted the ready efflux of potassium ions from cells and caused disorganisation of the outer lipopolysaccharide-rich regions of the cell envelope.