神经外科病房金黄色葡萄球菌的耐药性及MRSA基因多态性研究

Drug resistence and genetic polymorphism of methicillin-resistant Staphylococcus aureus in department of neurosurgery

目的了解某院神经外科病房金黄色葡萄球菌的耐药性及耐甲氧西林金黄色葡萄球菌(MRSA)分子流行病学特点。方法采用纸片扩散法检测2008-2011年从神经外科住院患者分离的金黄色葡萄球菌254株的耐药性,MRSA的鉴定采用头孢西丁纸片扩散法和检测femA、mecA基因的双重PCR方法;采用随机引物多态性技术(RAPD)对分离的32株MRSA做同源性分析。结果神经外科病房MRSA的分离率92.9%,对万古霉素、替考拉宁和利奈唑胺的敏感率为100%,对复方新诺明和克林霉素的敏感率分别为82.3%和74.4%,对左氧氟沙星、环丙沙星、红霉素和青霉素耐药率均大于95%;32株MRSA的RAPD图谱有4种类型(Ⅰ-Ⅳ型),Ⅰ型20株(62.5%),Ⅱ型7株(21.9%),Ⅲ型3株(9.3%),Ⅳ型2株(6.2%)。结论某院神经外科病房存在基因型为Ⅰ型的MRSA菌株的暴发流行。

Objective To investigate the drug resistance of Staphylococcus aureus and genetic polymorphism of methicillin-resistant Staphylococcus aureus（MRSA） in a department of neurosurgery of a hospital.Methods Antibiotic resistance of 254 strains isolated from 2008-2011 in the department of neurosurgery was determined by K-B disk diffusion.MRSA was identified by cefoxitin of disk diffusion and double-PCR of mecA and femA gene.Randomly amplified polymorphic DNA（RAPD） was applied to analyze the homology of MRSA strains.Results The prevalence of MRSA was 92.9%.All isolated strains were susceptible to vancomycin,teicoplanin and linezolid.The susceptibility to trimethoprim/sulfamethoxazole and chloramphenicol was 82.3% and 74.4%,respectively.The resistant rates against levofloxacin,erythromycin,ciprofloxacin and penicillin were higher than 95%,respectively.Four different RAPD patterns were found among 32 strains in the department of neurosurgery,and most of MRSA was type I（62.5%）.Conclusion Type I MRSA outbreak exists in the neurosurgery ward of the hospital.