Bergmans D C, Bonten M J, van Tiel F H, Gaillard C A, van der Geest S, Wilting R M, de Leeuw P W, Stobberingh E E
Department of Internal Medicine, University Hospital Maastricht, The Netherlands.
Thorax. 1998 Dec;53(12):1053-8. doi: 10.1136/thx.53.12.1053.
Ventilator-associated pneumonia (VAP) caused by Pseudomonas aeruginosa is usually preceded by colonisation of the respiratory tract. During outbreaks, colonisation with P aeruginosa is mainly derived from exogenous sources. The relative importance of different pathways of colonisation of P aeruginosa has rarely been determined in non-epidemic settings.
In order to determine the importance of exogenous colonisation, all isolates of P aeruginosa obtained by surveillance and clinical cultures from two identical intensive care units (ICUs) were genotyped with pulsed field gel electrophoresis.
A total of 100 patients were studied, 44 in ICU 1 and 56 in ICU 2. Twenty three patients were colonised with P aeruginosa, seven at the start of the study or on admission and 16 of the remaining 93 patients became colonised during the study. Eight patients developed VAP due to P aeruginosa. The incidence of respiratory tract colonisation and VAP with P aeruginosa in our ICU was similar to that before and after the study period, and therefore represents an endemic situation. Genotyping of 118 isolates yielded 11 strain types: eight in one patient each, two in three patients each, and one type in eight patients. Based on chronological evaluation and genotypical identity of isolates, eight cases of cross-colonisation were identified. Eight (50%) of 16 episodes of acquired colonisation and two (25%) of eight cases of VAP due to P aeruginosa seemed to be the result of cross-colonisation.
Even in non-epidemic settings cross-colonisation seems to play an important part in the epidemiology of colonisation and infection with P aeruginosa.
铜绿假单胞菌引起的呼吸机相关性肺炎（VAP）通常先有呼吸道定植。在暴发期间，铜绿假单胞菌定植主要源于外源性来源。在非流行环境中，很少确定铜绿假单胞菌不同定植途径的相对重要性。
为了确定外源性定植的重要性，对从两个相同的重症监护病房（ICU）通过监测和临床培养获得的所有铜绿假单胞菌分离株进行脉冲场凝胶电泳基因分型。
共研究了100例患者，ICU 1中有44例，ICU 2中有56例。23例患者被铜绿假单胞菌定植，7例在研究开始时或入院时定植，其余93例患者中有16例在研究期间定植。8例患者发生了由铜绿假单胞菌引起的VAP。我们ICU中铜绿假单胞菌呼吸道定植和VAP的发生率与研究期间前后相似，因此代表一种地方病情况。对118株分离株进行基因分型产生了11种菌株类型：8种各有1例患者，2种各有3例患者，1种有8例患者。根据分离株的时间顺序评估和基因分型一致性，确定了8例交叉定植病例。16例获得性定植中有8例（50%）以及8例由铜绿假单胞菌引起的VAP中有2例（25%）似乎是交叉定植的结果。
即使在非流行环境中，交叉定植似乎在铜绿假单胞菌定植和感染的流行病学中起重要作用。
