目的:分析重症加强治疗病房呼吸机相关性肺炎（VAP）的病原菌分布特点及变迁。方法:对中国医科大学附属第一医院重症加强治疗病房（ICU）2003年1月至2006年12月间VAP病人的痰培养病原菌及药敏结果进行回顾性分析。结果:4年中ICU中VAP发生率为19.1%。铜绿假单胞菌为最常见菌，洋葱伯克霍尔德菌、鲍曼不动杆菌、嗜麦芽窄食单胞菌4年中均排在前6位。金黄色葡萄球菌在2003-2005年间逐年增加，2006年有所下降；脑膜败血黄杆菌在2005、2006年分离率明显下降；近两年肺炎克雷伯杆菌的分离率增加。2004年铜绿假单胞菌对多种抗生素耐药率高（均在75%以上）。4年中对亚胺培南的耐药率均超过40%。鲍曼不动杆菌对亚胺培南和左氧氟沙星耐药率较低，嗜麦芽窄食单胞菌对复方磺胺甲恶唑、环丙沙星和左氧氟沙星耐药率较低。分离出的金黄色葡萄球菌中，耐甲氧西林金黄色葡萄球菌（MRSA）所占比例高。结论:铜绿假单胞菌、洋葱伯克霍尔德菌、鲍曼不动杆菌、嗜麦芽窄食单胞菌等非发酵菌仍为VAP主要致病菌。4年中VAP致病菌的分布特点和耐药性发生了改变。

Objective:To investigate the etiology and antimicrobial resistance of predominant pathogen of ventilatorassociated pneumonia (VAP) isolated from intensive care unit. Methods:The bacteria isolated from sputum specimen and antimicrobial resistance of patients with VAP admitted between January 2003 and December 2006 in the Department of Intensive Care Unit of the First Affiliated Hospital of China Medical University were analyzed retrospectively. Results:During the period, the incidence of VAP in ICU was 191%.Pseudomonas aeruginosa，Burkholderia cepacia,Acinetobacter baumannii and Stenotrophomonas maltophilia were the most frequently isolated bacteria of VAP.Staphylococcus aureus increased steadily from 2003 to 2005 and then decreased in 2006.The total number of isolated Chryseobacterium meningosepticum decreased in 2005-2006.While the number of Klebsiella pneumoniae increased in 2005-2006.The resistance rate of Pseudomonas aeruginosa to antibiotics increased progressively in 2004 (above 75%) and to imipenem exceeded 40% during 4 years.Acinetobacter baumannii was less resistant to imipenem and levofloxacin.The resistance of Stenotrophomonas maltophilia to compound sulfamethoxazole,ciprofloxacin and levofloxacin was the lowest.Methicillinresistant Staphylococcus aureus composed the biggest part of all isolated Staphylococcus aureus. Conclusion:The main pathogens of VAP in ICU are nonfermenting gramnegative bacilli.The predominant pathogens are Pseudomonas aeruginosa,Burkholderia cepacia,Acinetobacter baumannii and Stenotrophomonas maltophilia.The pathogens distribution and infection spectrum have changed during 4 yeas.