多重及泛耐药铜绿假单胞菌和鲍曼不动杆菌医院感染调查及产碳青霉烯酶表型研究

Investigation of nosocomial infections due to multidrug-resistant,pandrug-resistant Pseudoonas aeruginosa and Acinetobacter baumannii and study on carbapenemases-producing phenotype

目的：了解铜绿假单胞菌和鲍曼不动杆菌院内感染分布、耐药特点以及产碳青霉烯酶表型情况。方法回顾性收集2012年7月到2013年7月该院分离非重复铜绿假单胞菌和鲍曼不动杆菌医院感染菌株及病例。采用纸片扩散法（K-B 法）进行药敏试验，改良 Hodge 试验进行碳青霉烯酶初筛，初筛阳性菌株应用2-巯基丙酸协同法进一步检测金属酶。结果在研究期间，共纳入非重复铜绿假单胞菌250株，鲍曼不动杆菌132株。菌株标本类型以痰液（55．5％）为主，科室分布以重症监护病房（20．9％）为主。药敏试验显示：铜绿假单胞菌对测试药物敏感性较好，均大于70％以上，对 IPM 和 MEM 耐药率较低分别为8．5％、9．5％，然而鲍曼不动杆菌对测试药物耐药率较高达35．2％～77．4％，对 IPM 和 MEM 耐药率分别为35．2％、39．1％。多重耐药及泛耐药鲍曼不动杆菌医院感染发生率要高于铜绿假单胞菌分别为44．7％和24．0％；9．1％和2．8％。40株耐碳青霉烯类铜绿假单胞菌，碳青霉烯酶初筛阳性11株占27．5％，金属酶表型阳性2株占18．2％；49株耐碳青霉烯类鲍曼不动杆菌，碳青霉烯酶初筛阳性37株占75．5％，金属酶表型阳性1株占2．7％。结论该院铜绿假单胞菌和鲍曼不动杆菌对常用抗菌药物呈现不同耐药性，应加强监测。产碳青霉烯酶是鲍曼不动杆菌耐碳青霉烯类药物主要机制之一。产金属酶铜绿假单胞菌和鲍曼不动杆菌检出率较低。

Objective To understand the nosocomial infection distribution,drug resistance characteristics and carbapenemases-producing phenotype of Pseudomonas aeruginosa （PAE）and Acinetobacter baumannii （ABA）.Methods The nosocomial infection strains of non-repeated PAE and ABA isolated in this hospital and the infected cases from July 2012 to July 2013 were retrospec-tively collected.The antimicrobial susceptibility test was conducted by the disk diffusion method（K-B method）.The modified Hodge test was adopted to preliminarily screen carbapenemase and the positive strains of preliminary screening were further detected met-allo-beta-lactamase（MBL）by 2-mercaptopropionic acid synergy test.Results During the study period,250 strains of non-repeated PAE and 132 strains of ABA were included.All of them were primarily isolated from sputum specimens,accounting for 55.5%.The department distribution was dominated by the intensive care units（ICU）,accounting for 20.9%.The antimicrobial susceptibility test showed that the sensitivity of PAE to the testing anti-microbial drugs was more than 70%,its resistance rates to IPM and MEM were 8.5% and 9.5% respectively.However,the resistance rates of ABA to the testing anti-microbial drugs were up to 35.2%-77.4%,its resistance rates to IPM and MEM were 35.2%,39.1% respectively.The occurrence rates of multidrug-resist-ant and pandrug-resistant ABA nosocomial infection was higher than that of PAE,which were 44.7% and 24.0% and 9.1% and 2.8%,respectively.Among 40 strains of carbapenem-resistant PAE,11 strains（27.5%）were positive in the preliminary screening and 2 strains（18.2%）were positive of MBL phenotype.Among 49 strains of carbapeneme-resistant ABA,37 strains（75.5%）were positive in the preliminary screening and only 1 strain（2.7%）was positive of MBL phenotype.Conclusion PAE and ABA in our hospital exhibit different resistance to common antibacterial drugs.The monitoring should be strengthened.The production of car-bapenemsa is one the main mechanisms for PAE resistance to carbapenems.The detection rate of MBL-producing PAE and ABA is lower in our hospital.