金黄色葡萄球菌对万古霉素耐药机制的初步研究

目的了解金黄色葡萄球菌对万古霉素耐药机制。方法按照美国临床实验室标准化委员会(NCCLS)标准,应用琼脂平板稀释法及MRSA特异性基因mecA的扩增鉴定MRSA,诱导产生万古霉素耐药株,然后以超声破碎法提取外膜蛋白(OMP),经聚丙烯酰胺凝胶电泳(SDS-PAGE)分析OMP的成分,分光光度法扫描仪测定相关膜蛋白的相对含量。结果耐万古霉素金葡菌菌株中,分子量为45KD和14KD的膜蛋白的相对含量较金葡菌ATCC25923株和对万古霉素敏感的MRSA少。结论提示45KD和14KD膜蛋白减少或缺失与金葡菌对万古霉素耐药可能有密切关系。

Preliminary study on the mechanism of drug-resistance of Staphylococcus aureus to vancomycin

For the study of the drug resistance of Staphylococcus aureus to vancomycin, the meticillin resistant Staphylococcus aureus (MRSA) was identified with the agar plate dilution test advocated by the American National Clinical Laboratory Standards (NCCLS) Committee and amplification of the MRSA specific mecA gene by PCR, and was induced to produce the vancomycin resistant strain. The outer membrane protein (OMP) was extracted by ultrasonication, and its composition was analyzed by SDS PAGE relative content of OMP was determined by spectrophotometer. Experimental results showed that among the vancomycin resist strains, the relative content of OMP of the membrane protein with molecular weight of 45kDa and 14 kDa was less than those of Staphylococcus aureus ATCC25923 strain or vancomycin sensitive MRSA. It is concluded that the decreased amount or lack of the 45 kDa and 14 kDa membrane proteins may be closely related to the development of drug resistance to vancomycin.