香芹酚对耐甲氧西林金黄色葡萄球菌(USA300)抑菌机制的研究

Antibacterial Mechanism of Carvacrol Against MethicillinResistant Staphylococcus aureus(USA300)

【目的】研究香芹酚对耐甲氧西林金黄色葡萄球菌(MRSA)(USA300)的抑菌效果及其作用机制。【方法】测定香芹酚对MRSA标准菌株USA300的抑菌活性,并通过考察其对电导率、DNA外渗量、SDS-PAGE蛋白谱带、乳酸脱氢酶的含量、细菌形态结构以及生物被膜形成能力的影响探究香芹酚的抑菌机制。【结果】香芹酚的MIC为128～256μg/m L,MBC为512μg/mL;与对照组相比,2 MIC香芹酚作用于USA300 1 h后,菌悬液电导率上升5.57%±0.40%、DNA外渗量增加16.27±1.86μg/mL以及乳酸脱氢酶含量增长40.49%±2.77%;作用10 h后,可溶性蛋白质含量增多61.13%±7.63%;512μg/mL的香芹酚可以损伤USA300的细胞壁;亚抑菌浓度下,64μg/mL香芹酚作用于USA300后,形成的生物被膜减少68.86%±0.53%。【结论】香芹酚主要通过损伤USA300的细胞壁、增加细胞膜的通透性来抑制USA300的生长繁殖。

【Objective】The aim of this study was to investigate the antibacterial effect and the mechanism of carvacrol against Methicillin-resistant Staphylococcus aureus (USA300).【Method】The antibacterial activity of carvacrol on the MRSA standard strain USA300 was determined,and the antibacterial mech-anism of carvacrol was determined by exploring the influence of carvacrol on the conductivity,DNA ex-osmosis,SDS-PAGE protein band,LDH content,bacterial morphological structure and biofilm formation ability.【Result】MIC of carvacrol to USA300 was 128~256 μg/mL and MBC of carvacrol to USA300 was 512 μg/mL;Compared with the control group,after treating USA300 with 2 MIC carvacrol for 1 h, bacteria suspension conductivity was increased by 5.57%±0.40%,DNA exosmosis amount improved by 16.27±1.86 μg/mL and LDH content increased by 40.49%±2.77%;After treating for 10 h,soluble pro-tein content was increased by 61.13%±7.63%;2 MIC carvacrol could destroy the cytoderm of bacteria;Compared with the control group,the total amount of biofilm formed was decreased by 68.86%±0.53% after treating USA300 with 64 μg/mL carvacrol at Sub-MIC.【Conclusion】The antibacterial mechanism of carvacrol is mainly by destroying cytoderm and increasing cell membrane permeability of USA300.