Detection of galangin-induced cytoplasmic membrane damage in Staphylococcus aureus by measuring potassium loss
Detection of galangin-induced cytoplasmic membrane damage in Staphylococcus aureus by measuring potassium loss
复制标题
DOI：
10.1016/j.jep.2005.04.014
复制
发表时间：
2005-10-03
影响因子：
5.4
通讯作者：
Lamb, AJ
中科院分区：
文献类型：
--
作者：
Cushnie, TPT;Lamb, AJ
高良姜是蜂胶或“蜂胶”和蜡菊（一种南非土著人用来治疗感染的多年生草本植物）中有效的抗菌成分之一。通过比较细菌细胞悬浮液的钾损失谱，研究了该化合物和已知作用机制的抗菌剂对金黄色葡萄球菌细胞质膜完整性的影响。琼脂稀释法测定黄酮醇高良姜素、抑菌抗生素新生物素和杀菌抗生素青霉素G对金黄色葡萄球菌NCTC 6571的最低抑制浓度（mic）分别为50 μ G /mL、62.5 ng/mL和31.3 ng/mL。将5 × 10(7) cfu/mL的金黄色葡萄球菌悬浮在含有50 μ g/mL高良姜素的“无钾”培养基中，12 μ g/mL后，其活力下降了60倍。1 × 109 cfu/mL金黄色葡萄球菌在50 μ g/mL高良姜素中培养12 h后，比未处理的对照群体多损失21%的钾。新生物素对钾流失没有影响，但在31.3 ng/mL青霉素G中培养的种群钾流失增加了6%。这些数据清楚地表明，高良姜会导致金黄色葡萄球菌细胞钾流失显著增加，这可能是由于对细胞质膜的直接损伤或通过细胞壁的自溶/削弱和随后的渗透溶解造成的间接损伤。2005爱思唯尔爱尔兰有限公司版权所有。
Galangin is one of the active antimicrobial principles of propolis or 'bee glue' and Helichrysum aureonitens, a perennial herb used by South African indigenes to treat infection. The effect of this compound and antibacterial agents with known mechanisms of action upon the cytoplasmic membrane integrity of Staphylococcus aureus was investigated by comparing potassium loss profiles from bacterial cell suspensions. Using an agar dilution assay, the minimum inhibitory concentrations (MICs) of the flavonol galangin, the bacteriostatic antibiotic novobiocin and the bactericidal antibiotic penicillin G against Staphylococcus aureus NCTC 6571 were determined as being 50 mu g/mL, 62.5 ng/mL and 31.3 ng/mL, respectively. When 5 x 10(7) cfu/mL Staphylococcus aureus were suspended in 'potassium-free' media containing 50 mu g/mL galangin, a 60-fold decrease in viability was observed after 12 It. Populations of I x 109 cfu/mL Staphylococcus aureus incubated for 12 h in 50 mu g/mL galangin lost 21% more potassium than untreated control populations. Novobiocin had no effect on potassium loss, but populations incubated in 31.3 ng/mL penicillin G exhibited a 6% increase in potassium loss. This data clearly demonstrates that galangin causes a significant increase in potassium loss from Staphylococcus aureus cells, which may be attributed to either direct damage to the cytoplasmic membrane or indirect damage effected through autolysis/weakening of the cell wall and consequent osmotic lysis. (C) 2005 Elsevier Ireland Ltd. All rights reserved.