耐甲氧西林金黄色葡萄球菌的药敏试验及其耐药基因分析

Antimicrobial Susceptibility Testing and Molecular Identification of Drug-resistance Genes for MRSA Isolates

【目的】研究耐甲氧西林金黄色葡萄球菌(MRSA)分离株的抗生素的敏感谱和耐受机制。【方法】用PCR方法对58份被鉴定为MRSA分离株的耐药基因进行分析。【结果】58份MRSA分离株的药敏试验敏感结果为:万古霉素(100%),庆大霉素(86.2%),氯林可霉素(39.7%)和红霉素(12%)。在所有的MR-SA分离株中,组成型MRSA表型和ermA比可诱导型MRSA表型和ermC更普遍,没有检测到ermB或msrA基因的分离株。在4份四环素耐受的MRSA分离株中,3份检测到tet(M)基因阳性,而其余的分离株不能用PCR进行基因分型。【结论】MRSA常对多种抗生素耐受,原因是由于其含有多种耐药基因。

[Objective]To identify the antimicrobial susceptibility testing and resistance mechanisms of MRSA isolates. [Methods]Drug-resistance genes of 58 MRSA-identificated isolates were analysed via PCR. [Results]Fifty eight isolates were identified as MRSA. Antimicrobial susceptibility testing indicated susceptibility rates to： vancomycin （100%）, gentamicin （ 86. 2 %）, clindamycin （39. 7 %） and erythromycin （ 12. 0%）. Among our MRSA isolates, the MLS constitutive phenotype and ermA were more prevalent than the MLS inducible phenotype and ermC. No isolates had ermB or msrA. Out of 4 tetracycline-resistant MRSA isolates, 3 were identified as tet（M） and the other could not be typed. [Conclusion]Our results indicate that MRSA is commonly resistant to multiple antibiotics due to containing multiple drug-resistant genes.