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目的研究临床分离的耐甲氧西林金黄色葡萄球菌(MRSA)耐药性,检测MRSA葡萄球菌染色体mec盒(SCCmec)基因型,并进行杀白细胞素(PVL)毒力基因检测。方法采用标准平皿两倍稀释法测定250株MRSA对多种抗菌药物最低抑菌浓度(MIC),采用多重PCR方法对MRSA进行SCCmec基因分型,单一PCR方法对MRSA菌株进行PVL毒力基因检测。结果 250株MRSA经多重PCR方法检测SCCmec基因型,SCCmecⅡ-dcs型菌株30株,占12.0%,Ⅱ型的亚型1株,占0.4%,Ⅲ型62株,占24.8%,含有342 bp(dcs)额外扩增条带的Ⅲ型菌株141株,占56.4%,Ⅳ型7株,占2.8%,Ⅳa型1株,占0.4%,Ⅴ型1株,占0.4%,7株细菌未能分型,占2.8%,未发现Ⅰ型;单一PCR方法获得PVL呈阳性的菌株共2株,占临床分离MRSA的0.8%;各基因型对多种抗菌药物呈现不同程度的耐药。结论临床分离的MRSA以SCCmecⅢ型为主;其次为SCCmecⅡ型;有少量SCCmecⅣ型,少数菌PVL毒力基因阳性。
Objective To investigate the drug resistance of methicillin-resistant Staphylococcus aureus (MRSA) in clinical isolates and to detect the genotypes of mec boxes (SCCmec) of staphylococcus aureus in MRSA and to detect the cytotoxicity of leucocytic cytochrome (PVL). Methods The minimum inhibitory concentration (MIC) of 250 strains of MRSA against multiple antibiotics was determined by standard plate double dilution method. SCCmec was genotyped by multiplex PCR and PVL virulence genes were detected by single PCR. Results The genotypes of SCCmec were detected by multiplex PCR in 250 MRSA strains. There were 30 SCCmecⅡ-dcs strains (12.0%), 1 (Ⅱ) type 1, accounting for 0.4%, type Ⅲ 62 (24.8%) and containing 342 bp There were 141 type III strains (56.4%) with additional amplification bands, accounting for 2.8% of type Ⅳ strains, 1 strain of type Ⅳa (0.4%), 1 strain of type Ⅴ (0.4%), 7 strains of bacteria failed The genotypes accounted for 2.8%. No genotype Ⅰ was found. Two strains with positive PVL were obtained by single PCR method, accounting for 0.8% of MRSA isolates. The genotypes showed different degrees of resistance to various antimicrobial agents. Conclusion The clinical isolates of MRSA mainly SCCmec Ⅲ type, followed by SCCmec Ⅱ type; a small amount of SCCmec Ⅳ type, a few bacteria PVL virulence gene positive.