金黄色葡萄球菌耐药性(R)质粒的鉴定

金黄色葡萄球菌是重要的化脓菌之一。该菌引起的感染涉及临床许多领域；细菌易形成耐药性是该菌的另一重要特性。从基因水平分析，金黄色葡萄球菌的耐药性可能是由细菌染色体基因决定的，也可能是质粒基因所编码。因此，对耐药性（Ｒ）质粒的检测是研究金葡萄耐药基因的常用方法。但是，由于金葡菌细胞壁厚而坚固，抽提Ｒ质粒通常使用溶葡萄菌素（Ｌｙｓｏｓｔａｐｈｉｎ）。该试剂需进口且昂贵。本文使用一种经过改进的ｋａｄｏ和Ｌｉｕ质粒抽提法对耐药性金葡菌ＳＡ４２９菌株的Ｒ质粒进行鉴定。实验中以溶菌酶和十二烷基磺酸钠（ＳＤＳ）代替溶葡萄球菌素取得较为理想的结果。结果表明，ＳＡ４２９的氨基苄青霉素（ＡＰ）、四环素（ＴＣ）和链霉素（ＳＭ）的耐药性是由该菌所携带的一个４．６×１０３ｂｐ的Ｒ质粒所控制。该实验为快速抽提金葡菌的Ｒ质粒提供了一种可靠而经济的方法。

Characterization of R plasmids of staphylococcus aureus

S taphy.aureus is an important one of pyrulent pathogens.It causes a lot of infections involved in wide clinical fields.Another feature of the staphylococci is easy to develop resistance to many atibiotics.Therefore,determination of R plasmids from the staphylococci is a basic and necessary technique to study their resistance genes.However,it is not easy to extract the plasmids beause the staphylococcus has very strong cell wall.In the paper a R plasmid of Staph.aureus was determined by Kado and Liu modified method.The result suggested that the resistant strain,SA 429 ,carried a R plasmid encoding resistance to AP,TC and SM.In this technique lysostaphin was replaced by lysozyme and SDS.It implied that the method was simplified ,economic and useful for extract and further study staphylococci plasmids,as weel as other plasmids of other gram positive cocci such as pneumococci and streptococci.