目的探索留置导尿患者医院感染铜绿假单胞菌（Ｐａ）的感染途径和传播机制。方法从患者小便、脓液、痰液和患者相关环境公用拖帕和洗涤池中共分离出Ｐａ５１株，应用血清学、细菌素、质粒图谱、质粒限制性内切酶图谱、外膜蛋白图谱等方法进行了研究。结果５１株Ｐａ的血清学分型率为８０．４％，细菌素分型率为７７．１％，质粒携带率为６８．６％，呈４种流行模式；来源不同的Ａ、Ｂ、Ｃ三型质粒代表株经用ＥｃｏＲⅠ和ＨｉｎｄⅢ酶切，呈现相同限制性内切酶图谱。９株不同质粒图谱模式菌株，得到两种不同类型外膜蛋白图谱。结论患者与患者之间通过床头柜、床单、导尿管等为媒介，相互交叉感染是导致Ｐａ医院感染的重要因素；一种血清型的细菌可能被分成几种菌素型，同种菌素型也不一定对应于一种血清型；同种血清型的菌株可用质粒图谱分成几种亚型；Ｐａ的外膜蛋白图谱呈高度相似性，图谱模式同血清型无明显联系 Objective To explore the infection pathway and transmission mechanism of nosocomial infection with Pseudomonas aeruginosa (Pa) in patients with indwelling catheters. Methods Pa51 strains were isolated from urinary, pus, sputum and sputum of common patients and common pool of patient-related environment. Serological, bacteriocin, plasmid map, restriction endonuclease map and outer membrane protein map Were studied. Results The serotyping rates of 51 Pa were 80.4%, the bacteriocin typing rate was 77.1%, and the plasmid carrying rate was 68.6%, which showed four epidemic patterns. A, B and C The plasmid-expressing strain was digested with EcoR I and Hind III and showed the same restriction enzyme map. Nine strains of different plasmid map patterns, obtained two different types of outer membrane protein profiles. Conclusion Patients and patients through the bedside tables, bed sheets, urinary catheter as the medium, cross-infection is an important factor leading to Pa hospital infection; a serotype of bacteria may be divided into several types of antibiotics, Nor does it necessarily correspond to a serotype; isolates of the same serotype can be divided into several subtypes using plasmid maps; the profile of the outer membrane of Pa is highly similar and the pattern of the map is not significantly related to the serotype