50株耐甲氧西林金黄色葡萄球菌PVL基因检测及同源性分析

Detection of Panton-Valentine Leukocidin Gene and Analysis of Homology in 50 Meticillin-resistant Staphylococcus aureus Isolates

目的调查耐甲氧西林金黄色葡萄球菌(MRSA)的耐药谱及其同源性和杀白细胞素(PVL)携带情况,为临床治疗、选药和流行病学调查提供依据。方法根据CLSI指南中的纸片扩散法做药敏试验,用PCR法检测mecA基因和PVL基因,用重复基因外回文序列-聚合酶链反应(Rep-PCR)进行同源性分析。结果50株MRSA均检测出mecA基因,对苯唑西林和头孢西丁均耐药,对替考拉宁和万古霉素的敏感性为100.0%,对克林霉素、环丙沙星、哌拉西林/舒巴坦、复方新诺明、庆大霉素、头孢唑林、红霉素的敏感率分别为7.5%、1.9%、24.5%、92.5%、20.8%、1.9%、3.8%;22株MSSA对以上抗菌药物的敏感率明显高于MRSA;50株MRSA中20株检测出PVL基因,阳性率为40.0%,部分MRSA菌株有100.0%同源性。结论MRSA对抗菌药物的耐药性明显高于MSSA,尚未发现对万古霉素和替考拉宁的耐药菌株,MRSA携带PVL基因较高,部分MRSA菌株有较高同源性。

OBJECTIVE To investigate the antibiotic resistance pattern of MRSA, homology and carriage of Pantonvalentine leukocidin（PVL） in 50 meticillin-resistant Staphylococcus aureus isolates to guide the clinical treatment. Results of homology provide the proof for molecular epidemiology. METHODS According to CLSI＇s guideline, antimicrobial susceptibility tests were performed with disk diffusion method. PVL gene and mecA gene were detected by PCR. The homology was analyzed by repetitive estra-genic palindromic elements（Rep）-PCR method. RESULTS MecA gene was detected in all 50 MRSA isolates. All isolates MRSA were resistant to oxacillin and cefoxitin. But they were all sensitive to vancomycin and teicoplanin. The rates of sensitivity to clindamycin, ciprofloxacin, piperacillin and sulbactam, SMZ-TMP, gentamicin, cefazolin and erythromycin were 7. 5%, 1.9%, 24.5%, 92.5%, 20.8%, 1.9% and 3.8%, respectively. The resistance rates of MRSA were higher than that of MSSA. Twenty PVL genes were detected from 50 MRSA isolates. CONCLUSIONS The resistance rates of MRSA are higher than MSSA. There is no isolate resistant to vancomycin and teicoplanin. 40. 0 % MRSA carry PVL gene and part isolates have high homology.