ALTERED MEMBRANE-PERMEABILITY AS THE BASIS OF BACTERICIDAL ACTION OF METHDILAZINE

The growth inhibition of Escherichia coli and Staphylococcus aureus wa s accompanied by significant release of K+ and UV-absorbing small mole cules upon exposure to methdilazine, an extensively used phenothiazine antihistamine. A severe decrease in [U-C-14]glucose uptake and a rapi d efflux of hexose from sugar-preloaded bacteria were also observed bu t without visible cellular lysis. Considerable damage to membrane perm eability by methdilazine was proposed to explain the rapid loss in cfu /mL of the bacteria.