Bonten M J, Bergmans D C, Speijer H, Stobberingh E E
Division of Infectious Diseases, University Hospital Utrecht, The Netherlands.
Am J Respir Crit Care Med. 1999 Oct;160(4):1212-9. doi: 10.1164/ajrccm.160.4.9809031.
We investigated the endemicity of Pseudomonas aeruginosa in intensive care units (ICUs) through analyses of surveillance cultures (from the rectum, stomach, oropharynx, and trachea; n = 1,089), and clinical cultures (n = 2,393) from 297 consecutive patients. Multiple isolates of P. aeruginosa (n = 353) were genotyped. Variables associated with acquisition of respiratory tract colonization (RTC) were tested in a risk factor analysis. The mean daily prevalence of colonization was 34%. On admission, 22 patients had intestinal colonization and 13 had RTC. Twenty patients acquired colonization in the intestinal and 24 in the respiratory tract. Forty-four different genotypes were found; 38 (86%) were isolated from individual patients only. In all, 37 patients had RTC with a total of 38 genotypes: 13 (34%) were colonized on admission, 9 (24%) acquired RTC with a novel genotype during a stay in the ICU, five (13%) acquired colonization from their intestinal tract and three (8%) were colonized via cross-acquisition. In eight patients (21%), no route could be demonstrated for colonization. Antibiotics providing P. aeruginosa with a selective growth advantage were associated with acquired RTC. Endemicity of colonization with P. aeruginosa is characterized by polyclonality, and seems to be maintained by continuous admittance of colonized patients and selection pressure from antibiotics rather than by cross-acquisition.
我们通过对297例连续患者的监测培养物（来自直肠、胃、口咽和气管；n = 1089）和临床培养物（n = 2393）进行分析，研究了重症监护病房（ICU）中铜绿假单胞菌的地方性流行情况。对多个铜绿假单胞菌分离株（n = 353）进行了基因分型。在一项危险因素分析中测试了与呼吸道定植（RTC）获得相关的变量。定植的平均每日患病率为34%。入院时，22例患者有肠道定植，13例有RTC。20例患者在肠道获得定植，24例在呼吸道获得定植。发现了44种不同的基因型；38种（86%）仅从个体患者中分离得到。共有37例患者发生RTC，共有38种基因型：13例（34%）入院时即被定植，9例（24%）在ICU住院期间获得了新基因型的RTC，5例（13%）从肠道获得定植，3例（8%）通过交叉感染被定植。在8例患者（21%）中，无法证明定植途径。给予铜绿假单胞菌选择性生长优势的抗生素与获得性RTC相关。铜绿假单胞菌定植的地方性流行以多克隆性为特征，似乎是通过定植患者的持续入院和抗生素的选择压力而非交叉感染来维持的。
