铜绿假单胞菌Ⅲ型分泌系统相关毒力基因的临床意义  

Clinical significance of virulence-related genes of type m secretion system of Pseudomonas aeruginosa

作　　者：卓超[1] 王露霞[1] 肖书念[1] 李红玉[1] 邱桂霞[1] 钟南山[1] 

机构地区：[1]广州医学院第一附属医院呼吸疾病国家重点实验室,510230

出　　处：《中华烧伤杂志》2010年第5期354-359,共6页Chinese Journal of Burns

基　　金：国家传染病重大专项（2009ZX10004-109）;广东省科技厅重点攻关项目（2009A030301011）

摘　　要：目的 了解铜绿假单胞菌Ⅲ型分泌系统（TTSS）的毒力基因exo U、exo S的临床意义.方法 来自5家医院临床分离的铜绿假单胞菌189株,采用PCR调查毒力基因exo U、exo S在铜绿假单胞菌中的发生率;微量稀释法测定抗菌药物对细菌的MIC;对携带exo U＋/exo S-型或exo U-/exo S＋型细菌（从痰液分离）的60例阳性患者资料进行回顾性分析,观察患者临床特征和转归情况.对数据进行x2检验. 结果 PCR检测显示,161株携带TTSS,其中120株exo U-/exo S＋,31株exo U＋/exo S-,3株exo U＋/exo S＋,7株exo U-/exo S-;剩余28株为TTSS阴性.痰液标本和血液标本均以exo U-/exo S＋表型最常见,分别占其TTSS阳性菌株的72.0%（72/100）和81.5%（44/54）.药物敏感试验分析,TTSS阴性菌株对头孢哌酮/舒巴坦、头孢他啶、阿米卡星、头孢吡肟的耐药性均高于TTSS阳性菌株（x2值分别为10.1、16.1、9.3、33.8,P值均小于0.01）.exo U＋/exo S-菌株和exo U-/exo S＋菌株的药物敏感试验结果 相似（x2值为0.08～2.04,P值均大于0.05）.回顾性分析表明,exo U＋/exo S-型患者临床特征是多有气管插管史、ICU住院史、抗感染治疗多采用联合用药,以铜绿假单胞菌感染居多;exo U-/exo S＋的临床特征是多存在肺部基础疾病,预后好于前者,以铜绿假单胞菌定植居多. 结论 TTSS存在于大多铜绿假单胞菌临床菌株中,检查痰液标本来源的铜绿假单胞菌exo U或exo S基因,对分析患者临床特征和治疗转归有一定指导意义.Objective To study the clinical significance of virulence genes exo U and exo S of type secretion system （TTSS） of Pseudomonas aeruginosa （PA）. Methods One hundred and eighty-nine clinical isolates of PA were collected from five hospitals. The incidence of virulence genes exo U and exo S in PA were determined with PCR. Minimum inhibitory concentration of anti-bacterial drug for PA was deter mined with microdilution method. The clinical features and outcomes of 60 hospitalized patients colonized or infected with exo U ＋/exo S - postive or exo U -/exo S ＋ postive PA isolated from sputum were analyzed retrospectively. Data were processed with chi-square test. Results Among the 189 PA isolates, 85.2% （161/189） harbored TTSS genes, including exo U -/exo S ＋ type （120 isolates）, exo U ＋/exo S- type （31 isolates）, exo U -/exo S - type （7 isolates）, and exo U ＋/exo S ＋ type （3 isolates）. 72.0% （72/ 100） isolates from sputum and 81.5% （44/54） isolates from blood belonged to exo U -/exo S ＋ genotype. Compared with those of TTSS-negative isolates, the antimicrobial resistance of TTSS-positive isolates to cef operazone/sulbactam, ceftazidime, amikacin, and cefepime were lower （withx2 value respectively 10. 1, 16.1, 9.3, 33.8, P values all below 0.01 ）. The antimicrobial resistance to all examined drug between exo U-/exo S ＋ type and exo U ＋/exo S - type isolates was close （ withx2 values from 0. 08 to 2.04, P values all above 0.05）. Patients detected with exo U ＋/exo S - positive PA isolated from sputum were significantly associated with PA infection, and they usually had history of tracheal intubation, ICU hospitalization, and combined use of drugs for anti-infection treatment. Patients detected with exo U -/exo S ＋ positive PA iso lated from sputum were significantly associated with PA colonization, which had basic lung disease and better outcome than the former infection type. Conclusions The TTSS exists in most clinical isolates of PA. De tection of exo U

关 键 词：铜绿假单胞菌 Ⅲ 型分泌系统 exo U 基因 exo S 基因 临床意义 

分 类 号：R686[医药卫生—骨科学]