戴氏绿僵菌变种拮抗耐甲氧西林金黄色葡萄球菌的作用

Metarhizium Taii Variety Against Methicillin Resistant Staphylococcus Aureus

为明确戴氏绿僵菌变种无性型是否具有拮抗耐甲氧西林金黄色葡萄球菌的作用,对戴氏绿僵菌变种无性型进行发酵培养,采用琼脂扩散法测定其在不同pH值、培养温度条件下的发酵上清拮抗耐甲氧西林金黄色葡萄球菌WHO2的活性。对发酵上清进行高温或蛋白酶K处理,测定其抗菌活性的变化,对发酵上清拮抗临床分离的金黄色葡萄球菌的活性进行测定。研究结果表明:戴氏绿僵菌变种无性型发酵液上清对耐甲氧西林金黄色葡萄球菌WHO2具有明显拮抗作用;pH值为5.6～6.0,温度为30℃是戴氏绿僵菌变种抗菌成分表达的最适条件;该抗菌成分具有耐高温和抗蛋白酶K水解特性;戴氏绿僵菌变种无性型发酵液上清对临床分离的耐甲氧西林金黄色葡萄球菌及普通金黄色葡萄球菌均有拮抗作用。

In this study, we examined whether the Metarhizium taii var has antimicrobial property a- gainst methicillin resistant Staphylococcus aureus. The Metarhizium taii var was cultured in respective pH or temperature conditions. Then fermentation supernatant was extracted to detect the antimicrobial activity against methicillin resistant Staphylococcus aureus WHO2. The antimicrobial activity of the fer- mentation supernatant was analyzed by agarose radial diffusion assay. Fermentation supernatant was treated by high temperature or proteinase K digestion to investigate its stability. Antimicrobial proper- ties of Metarhizium taii var against some strains of SA patient isolates were also investigated. Results ：Here we provide evidence that the fermentation supernatant of Metarhizium taii var possesses antimi- crobial properties against WHO2. The antimicrobial composition expressed in optimal conditions of pH 5.6 - 6.0, temperature 30℃. The antibacterial components were stable against heating or proteinase K digestion. The fermentation supernatant of Metarhizium tail var against all strains of SA patient iso- lates used in our study.