铜绿假单胞菌临床菌株TTSS表达水平及相关因素分析  

Differential Expression Analyses of Type Ⅲ Secretion System and Related Factors in Clinical Strains of Pseudomonas aeruginosa

作　　者：吴国营[1] 杨洪江[1] 巴兆粉[1] 李群 吴海鹏 林书祥[2] 王维[2] 

机构地区：[1]工业发酵微生物教育部重点实验室,天津科技大学生物工程学院,天津300457 [2]天津市儿童医院,天津300074

出　　处：《中国生物化学与分子生物学报》2012年第2期158-163,共6页Chinese Journal of Biochemistry and Molecular Biology

基　　金：国家自然科学基金项目(No.30970114)~~

摘　　要：Ⅲ型分泌系统(typeⅢsecretion system,TTSS)是铜绿假单胞菌的重要致病因子.分析临床菌株中TTSS的表达水平,对于研究铜绿假单胞菌的致病机制具有重要意义.本研究通过测定融合报告基因exsA-lacZ和exoT-lacZ编码的β-半乳糖苷酶活力,分析了150株铜绿假单胞菌临床菌株exsA和exoT基因的表达水平,发现71株(47.33%)细菌exsA基因的表达为阳性6,5株(43.33%)细菌exoT基因的表达为阳性,基因exsA与exoT表达水平存在正相关(P<0.001),且不同菌株间两者表达水平差异较大.采用统计学方法对实验结果进一步分析发现,TTSS表达与呼吸道感染等临床症状相关(P<0.05);与标本的分离时间相关(P=0.029);与菌株亚胺青霉烯耐药性存在负相关(P<0.05).本研究结果显示,铜绿假单胞菌临床菌株TTSS表达水平差异较大,与多种因素存在相关性.Type Ⅲ secretion system（TTSS） is a virulence factor of Pseudomonas aeruginosa,and is important for the pathogenesis of clinical isolated strains.In this report,transcription fusion reporter exsA-lacZ and exoT-lacZ were used to analyze the TTSS expression using the β-galactosidase assay for 150 clinical strains.The result showed that 71（47.33%） and 65（43.33%） were for exsA and exoT expression,respectively.Statistical analysis revealed that the expression of both genes were correlated（P0.001）,yet the levels were highly diversified among the tested strains.Further analysis showed that the TTSS expression was correlated with the infection of respiratory tract（P 0.05）.Besides,the sampling time（P=0.029） and the imipenem resistance of the clinical isolates（P 0.05） were also influential factors.Our study demonstrated that the diverse TTSS expression in clinical isolated sample were related to multiple factors.

关 键 词：铜绿假单胞菌 Ⅲ型分泌系统(TTSS) Β-半乳糖苷酶 相关性 耐药性 

分 类 号：R378.991[医药卫生—病原生物学]