近年来,院内感染已逐渐为临床医生所重视,而革兰阴性菌是院内感染的主要致病菌,其中包括大肠杆菌、假单胞菌、克雷白杆菌、不动杆菌、嗜麦芽窄食单胞菌、变形杆菌等［１］。随着抗生素的广泛应用,细菌耐药率也逐渐上升,成为细菌感染性疾病治疗的一大难题。为了解院内感染菌群分 In recent years, nosocomial infections have been gradually valued by clinicians, and Gram-negative bacteria are the main pathogens of nosocomial infections, including Escherichia coli, Pseudomonas, Klebsiella, Acinetobacter, Stenotrophomonas Aeromonas, Proteus and other [1]. With the wide application of antibiotics, bacterial resistance rate also gradually increased, becoming a major problem for the treatment of bacterial infectious diseases. In order to understand the nosocomial bacterial flora