摘要目的：分析鲍曼不动杆菌耐药情况、分布特征，以及院内、院间主要克隆株的流行情况；探讨外膜蛋白介导对碳青霉烯类耐药的可能机制。方法收集青岛大学附属医院黄岛院区及解放军第四〇一医院2013年7月至2014年7月鲍曼不动杆菌临床分离株145株，采用纸片扩散法对其进行药敏试验；应用肠杆菌科基因间一致重复序列聚合酶链反应（ERIC-PCR）对菌株进行DNA分型及同源性分析，并采用PCR扩增外膜蛋白carO基因。随机抽取碳青霉烯耐药组30株鲍曼不动杆菌和敏感组17株鲍曼不动杆菌，用超声破碎及高速离心法提取外膜蛋白，并用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（SDS-PAGE）分析外膜蛋白的表达情况。结果145株鲍曼不动杆菌对临床常用16种抗菌药物普遍耐药，其中耐碳青霉烯类128株（耐药率88.3%），多重耐药（MDR）137株，泛耐药（XDR）126株；对米诺环素敏感率最高（79.3%），其次是阿米卡星（40.7%）。碳青霉烯耐药组carO基因阳性率达97.7%（125/128），碳青霉烯敏感组carO基因阳性率达17.6%（3/17）。SDS-PAGE显示，碳青霉烯敏感组17株鲍曼不动杆菌约在相对分子质量47000（16株）、37000（13株）和29000（13株）处有相应条带表达；而耐药组30株在这3处分别有20株、25株、23株呈不同程度的缺失或减弱。聚类分析显示，145株鲍曼不动杆菌共分为8个ERIC基因型，其中A型71株和E型37株，为主要流行株。结论两家医院临床分离鲍曼不动杆菌耐药情况严重且存在院内、院间流行。外膜蛋白carO基因在耐碳青霉烯类鲍曼不动杆菌中广泛存在，外膜蛋白表达的缺失或减弱是鲍曼不动杆菌耐碳青霉烯类的重要机制之一。

abstractsObjectiveTo study the characteristics of the distribution and drug resistance ofAcinetobacter baumannii, and the epidemiology of the main strains among wards and hospitals, and to investigate the role of outer membrane protein in producing resistance against carbapenems.Methods 145Acinetobacter baumannii strains were collected from July 2013 to July 2014 from Huangdao Hospital Affiliated to Qingdao University and 401st Army Hospital. Antimicrobial susceptibility test was carried out with K-B disk diffusion method. Enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR) was used for DNA typing and test of homology. The carO gene of outer membrane protein was amplified by PCR, and the outer membrane proteins were extracted by ultrasonication and ultracentrifuge method from 30 randomly selected carbapenem-resistantAcinetobacter baumannii and 17 carbapenem-sensitive strains. Sodium dodecyl sulfate-polyacrylamide gel electropheresis (SDS-PAGE) was used to analyze the expressions of outer membrane proteins.Results 145Acinetobacter baumannii strains were generally resistant to 16 common antimicrobial agents, with the highest susceptibility rate of 79.3% for minocycline, followed by susceptibility rate of 40.7% for amikacin. There were 128 carbapenem-resistant strains (resistance rate of 88.3%), 137 multidrug-resistant strains and 126 extensively drug-resistant strains. The detection rates of carO gene were 97.7%(125/128)and 17.6%(3/17) in carbapenem-resistant and sensitive strains respectively. Around position of relative molecular mass 47 000, 16 of 17 sensitive isolates were expressed this protein, while 20 of 30 resistant ones were detected nothing or fade; 13 of 17 sensitive isolates were expressed around position of relative molecular mass 37 000 and 29 000 while 25 were detected nothing or fade around position of relative molecular mass 37 000 and 23 were detected nothing or fade around position of relative molecular mass 29 000 in 30 resistant ones. 145Acinetobacter baumannii were classified into 8 types based on ERIC-PCR electrophoresis patterns, and the major prevalence types were type A (71 strains) and type E (37 strains).Conclusions Drug resistance of clinically isolatedAcinetobacter baumannii is a serious problem in two hospitals; drug-resistant strains are spread and epidemic among wards and hospitals. The carO gene of outer membrane protein is widespread in carbapenem-resistantAcinetobacter baumannii. The loss or fading of outer membrane protein may play an important role inAcinetobacter baumannii resistance to carbapenems drugs.