The main bacteria were Gram-negetive ones,among which the predominant consisted of pseudomonas aeruginosa,Escherichia coil and Klebsiella pneumoniae.

• 革兰阴性杆菌对三代头孢、亚胺培南、氟喹诺酮类敏感,对一、二代头孢及氨基糖苷类有较高耐药率。