Gram-negative bacilli were 474 strains(40.8%),the predominant pathogens were Escherichia coli(9.9%),Klebsiella pneumoniae(7.1%),Pseudomonas aeruginosa(5.4%),and Enterobacter cloacae(5.2%).

• G-杆菌以大肠埃希菌(9.；9%25)、肺炎克雷伯菌(7