Bactericidal Action of A Quaternary Ammonium Disinfectant, Didecyldimethyl Ammonium Chloride, against Staphylococcus aureus 高橋 中夫 橋田 鉄治 藤原 澄久 加藤 恵一 西原 力 公益社団法人日本薬学会 衛生化学 0013273X 40 4 344 350 1994-08-31 The study was conducted using a quaternary ammonium disinfectant, didecyldimethyl ammonium chloride (DDAC), whose minimum lethal concentration (MLC) against Staphylococcus aureus was 32 μg/ml. No remaining viable cells were detected even after a short 20 s treatment with DDAC at the MLC. Treatment with DDAC caused to form blebs on the cell surface, and K^+, 260 nm absorbing materials and phospholipid leaked out from the cells. The experiment using ^<14>C-labeled DDAC showed that the disinfectant was taken up in a biphasic curve to the cell regardless of the treatment temperature or time. The radioactivity was distributed significantly in the membrane fraction and the cytoplasm fraction. Tetramethyl ammonium chloride showed no biocidal activity and had no effect on the activity or uptake of DDAC. From these results, it was deduced that DDAC, at bactericidal levels, is adsorbed physicochemically, by hydrophobic interaction, onto the cell membrane, where it can react with lipid to cause significant damage to the structure and function of the membrane, leading to death. 1994-08-31 110003642067 AN00021540 3896955 ENG CJPref NDL NII-ELS 3 1 Bactericidal Action of A Quaternary Ammonium Disinfectant, Didecyldimethyl Ammonium Chloride, against Staphylococcus aureus TAKASAKI ATSUO HASHIDA TETSUJI FUJIWARA SUMIHISA KATO KEIICHI NISHIHARA TSUTOMU The Pharmaceutical Society of Japan Japanese Journal of Toxicology and Environmental Health The study was conducted using a quaternary ammonium disinfectant, didecyldimethyl ammonium chloride (DDAC), whose minimum lethal concentration (MLC) against Staphylococcus aureus was 32 μg/ml. No remaining viable cells were detected even after a short 20 s treatment with DDAC at the MLC. Treatment with DDAC caused to form blebs on the cell surface, and K^+, 260 nm absorbing materials and phospholipid leaked out from the cells. The experiment using ^<14>C-labeled DDAC showed that the disinfectant was taken up in a biphasic curve to the cell regardless of the treatment temperature or time. The radioactivity was distributed significantly in the membrane fraction and the cytoplasm fraction. Tetramethyl ammonium chloride showed no biocidal activity and had no effect on the activity or uptake of DDAC. From these results, it was deduced that DDAC, at bactericidal levels, is adsorbed physicochemically, by hydrophobic interaction, onto the cell membrane, where it can react with lipid to cause significant damage to the structure and function of the membrane, leading to death. 高橋 中夫 TAKASAKI ATSUO Faculty of Pharmaceutical Sciences, Osaka University 橋田 鉄治 HASHIDA TETSUJI Faculty of Pharmaceutical Sciences, Osaka University 藤原 澄久 FUJIWARA SUMIHISA Faculty of Pharmaceutical Sciences, Osaka University 加藤 恵一 KATO KEIICHI Faculty of Pharmaceutical Sciences, Osaka University 西原 力 NISHIHARA TSUTOMU Faculty of Pharmaceutical Sciences, Osaka University