仅黏菌素敏感的多重耐药铜绿假单胞菌分子流行病学研究

Molecular Epidemiological Study of Colistin-Only-Sensitive Strains in Multi-Drug Resistant Pseudomonas aeruginosa

目的 从基因水平了解多重耐药铜绿假单胞菌中仅黏菌素敏感铜绿假单胞菌（COS-PA）的流行情况。方法 ①收集本院灼伤科2001年3月至2003年12月临床分离的铜绿假单胞菌52株，其中COS-PA32株。②收集外科重症监护病房（SICU）2003年1月至2003年12月临床分离的铜绿假单胞菌57株，其中COS．PA22株；收集SICU水池下水口非仅黏菌素敏感铜绿假单胞菌（non-COS-PA）1株。③采用多种引物随机扩增DNA多态性（RAPD）技术和统计学方法分析其流行情况。结景①灼伤科2001～2003这3年的COS-PA，经RAPD（引物ERIC2、325、272）分型均为同一型别（Burn-A型）。②SICU2003年收集的COS-PA，经RAPD（引物325）分型为同一型别（SICU-A型）；在SICU收集的non-COS-PA也多数呈同一型别（SICU—B型），自SICU水池下水口收集到的1株non-COS-PA也属于此型。③灼伤科及SICU经RAPD（引物325）联合分析证实，两个科室的COS-PA为不同型别，无同源性。结论 灼伤科和SICU都存在科室内COS-PA流行，SICU还存在non-COS-PA流行。应严格消毒隔离措施，加强对铜绿假单胞菌在潮湿环境及患者中流行情况的严密监测。多种引物RAPD分析是判断铜绿假单胞菌流行情况的有利工具。

Objective To genetically analyze the epidemiology of colistin-only-sensitive Pseudomonas aeruginosa （COS-PA） in burn ward and SICU of Ruijin Hospital. Methods Fifty-two Pseudomonas aeruginosa isolates from burn ward from March 2001 to December 2003 were collected, in which 32 strains were COS-PA. Fifty-seven Pseudomonas aeruginosa isolates from SICU from January 2003 to December 2003 were collected, in which 22 strains were COS-PA. The rest were non-COS-PA, including one strain found in the bottom of the washstand. Multi-primer random amplified polymorphic DNA（RAPD） analysis was applied to analyze the strains. Results RAPD analysis （primer ERIC2, 325 and 272） showed all COS-PA from burn ward in the three years were identical（ Burn-A type）. Primer 325 RAPD showed all COS-PA from SICU in 2003 were identical（SICU-A type）, but the Burn-A type and SICU-A type were distinctly different. Most of the non-COS-PA from SICU also showed the trend of prevalence, which was defined as SICU-B type in RAPD typing, including the strain found in the bottom of the washstand. Conclusion The COS-PA of different RAPD types were prevalent both in burn ward and SICU. The cross-infection was severe and strict methods of disinfection and sterilization should be implemented. Meanwhile the epide-miology of Pseudomonas aeruginosa in moist environment and patients should be closely monitored. The multi-primer RAPD analysis is an excellent method in typing Pseudomonas aeruginosa.