产超广谱β-内酰胺酶菌株所致医院获得性泌尿道感染的调查与危险因素分析

目的了解致医院获得性泌尿道感染（HAUTI）的革兰阴性杆菌的分布特点及产超广谱β-内酰胺酶（ESBLs）菌株的耐药性现状,并对产ESBLs菌株所致HAUTI的危险因素进行分析。方法收集2007年1月至2008年12月发生院内革兰阴性菌HAUTI的住院病例共299例,对所采集的革兰阴性菌株进行鉴定,并用纸片琼脂扩散法检测所有革兰阴性菌株的药物敏感性,采用双纸片协同试验进行ESBLs表型确证。结合患者的临床资料进行多因素Logistic回归分析产ESBLs菌株致HAUTI的危险因素。结果 299株病原菌中大肠埃希菌分离率最高（60.87%）,其次为铜绿假单胞菌（16.39%）、肺炎克雷伯菌（15.72%）,299株革兰阴性菌中共检出产ESBLs菌株144株（48.16%）,全部为大肠埃希菌和肺炎克雷伯菌,大肠埃希菌和肺炎克雷伯菌中产ESBLs检出率分别为63.19%和61.70%。产酶菌株对多种抗菌药物的耐药率明显高于非产酶菌株;入住重症监护病房（ICU）、前期第3代头孢菌素类抗菌药物的使用和留置尿管是独立的院内产ESBLs细菌感染的危险因素[比值比（OR）分别为0.07、0.14、4.87,P〈0.001]。结论致HAUTI革兰阴性菌中产ESBLs菌株占据较高比例,与不产酶菌株相比,其对大多数抗菌药物均呈不同程度耐药。因此严格把握入住ICU、第3代头孢菌素及留置尿管使用指征,对防止产ESBLs菌株所致HAUTI具有突出的临床意义。

The epidemiology of hospital acquired urinary tract infections and risk factors for ESBLs-producing strains infection

Objective To investigate the distribution characteristic of Gram-negative bacilli in hospital acquired urinary tract infection（HAUTI） and the resistance of extended spectrum beta-lactamases（ESBLs）-producing strains,and analyze the risk factors for ESBLs-producing strains infection.Methods 299 patients with HAUTI caused by Gram-negative bacilli from January 2007 to December 2008 in hospital were analyzed.The susceptibilities of the strains to antibacterial agents were tested by the disk agar diffusion method.The ESBLs-producing strains of Gram-negative bacilli were detected for phaenotype by a double disk method.The risk factors for ESBLs-producing bacteria infection were analyzed by multi-factor Logistic regression analysis.Results In 299 clinical isolates,the isolating rate of Escherichia coli was the highest（60.87%）,followed by Pseudomonas aeruginosa（16.39%） and Klebsiella pneumoniae（15.72%）.144 clinical isolates（48.16%） out of 299 were ESBLs-producing strains,all of which were Escherichia coli and Klebsiella pneumoniae.The detection rates of ESBLs in Escherichia coli and Klebsiella pneumoniae were 63.19 % and 61.70%,respectively.ESBLs-producing strains were resistant to multiple antibiotics,and the resistance rate was higher than that of non-producing ESBLs strains.Intensive care unit（ICU） stay,previous use of third generation cephalosporin antibiotics and indwelling catheter were independent risk factors for ESBLs-producing strains infection[odd ratios（OR）=0.07,0.14 and 4.87,P0.001].Conclusions Producing ESBLs strains occupy a high proportion of Gram-negative bacilli that caused HAUTI.Compared with non-producing ESBLs strains,producing ESBLs strains are resistant to the majority of antibiotics.It is important to prevent ESBLs-producing bacteria infection by strict limitation on the indication of ICU stay,the use of third generation cephalosporin antibiotics and indwelling catheter.