甲氧西林耐药的金黄色葡萄球菌耐药性及分子流行病学调查

目的了解甲氧西林耐药的金黄色葡萄球菌(MRSA)的耐药性及分子流行病学特点。方法采用纸片扩散法及琼脂稀释法检测2002年从北京协和医院住院患者分离的165株MRSA的耐药性；采用脉冲场凝胶电泳(PFGE)技术对其中重症监护病房(ICU)和呼吸重症监护病房(RCU)分离的65株MRSA作同源性分析。结果165株MRSA对万古霉素和替考拉宁的敏感率为100％，对庆大霉素的耐药率为100％；对左氧氟沙星、四环素、红霉素耐药率分别为98．2％、96．3％、93．9％。对甲氧苄啶，磺胺甲噁唑和氯霉素敏感率分别为95．8％及98．8％；ICU和RCU病房分离MRSA的PFGE图谱有5种类型(A—E型)，以A型为主(56株)，A型又包括A1亚型(55株)和A2亚型(1株)。结论医院获得性MRSA是多重耐药菌，在ICU和RCU病房发生了基因型为A1亚型的MRSA菌株暴发流行。

Antibiotic resistance and molecular epidemiology profile of methicillin-resistant Staphylococcus aureus

Objective To investigate antibiotic resistance and molecular epidemiology profile of methicillin-resistant Staphylococcus aureus (MRSA) at Peking Union Medical College Hospital in Beijing. Methods Antibiotic resistance of 165 MRSA strains isolated from clinical specimen recovered in 2002 was determined by agar dilution and agar diffusion. Pulsed-field gel electrophoresis (PFGE) was used to type the chromosome DNA of MRSA isolates at intensive care unit (ICU) and respiratory care unit (RCU) wards. Results All of MRSA isolates were susceptible to vancomycin and teicoplanin. The resistance to levofloxacin, tetracycline and erythromycin among 165 strains of MRSA was 98.2%, 96.3% and 93.9%, respectively. The sensitivity to trimethoprim/sulfamethoxazole and chloramphenicol were 95.8% and 98.8%, respectively. Five different PFGE patterns (A-E) were found among 65 MRSA strains at ICU and RCU wards. Most of MRSA in two wards were A pulsotype (56 strains). A pulsotype included A1 subtype (55 strains) and A2 subtype (1 strain). Conclusion Hospital acquired MRSA is multi-resistant to antibiotics. A1 subtype MRSA outbreak occured at ICU and RCU wards in 2002.