铜绿假单胞菌Ⅲ型分泌系统分泌蛋白ExoU与耐药性的关系研究  

Investigation of the relationship between secretry protein ExoU of Pseudomonas aeruginosa type 3 secretion system and drug resistance

作　　者：杨晓庆[1] 孙平[1] 薛寒[2] 徐子辉 YANG Xiao-qing;SUN Ping;XUE Han;XU Zi-hui(Department of Laboratory Medicine,Huazhong Agricultural University Hospital,Wuhan 430070,Hubei Province,China;Department of Laboratory Medicine,Zhongnan Hospital,Wuhan University,Wuhan 430071,Hubei Province,China;Department of Endocrinology,People’s Hospital of Wuhan University,Wuhan 430060,Hubei Province,China)

机构地区：[1]华中农业大学医院检验科,湖北武汉430070 [2]武汉大学中南医院检验科,湖北武汉430071 [3]武汉大学人民医院内分泌科,湖北武汉430060

出　　处：《中国临床药理学杂志》2022年第19期2324-2328,共5页The Chinese Journal of Clinical Pharmacology

基　　金：湖北省自然科学基金资助项目(2014CFB219)。

摘　　要：目的 分析铜绿假单胞菌Ⅲ型分泌系统分泌蛋白ExoU与耐药性的关系。方法 收集21株铜绿假单胞菌,用聚合酶链反应(polymerase chain reaction, PCR)检测菌株exoU以及exoS基因携带情况,用琼脂稀释法测定头孢他啶、头孢吡肟、氨曲南、亚胺培南、左氧氟沙星和环丙沙星对21株铜绿假单胞菌的最低抑菌浓度(minimal inhibitory concentration, MIC),通过序列比对分析耐药基因突变情况,用实时荧光定量PCR(real-time quantitative PCR,RT-PCR)检测铜绿假单胞菌中耐药相关基因(mexR,ampC和ampR)的表达量。结果 在21株铜绿假单胞菌中,有8株携带了exoU基因,13株携带了exoS基因,未发现同时携带exoU和exoS的菌株。药敏试验结果显示:所有携带exoU的菌株均对至少3种β内酰胺类药物具有耐药性。突变分析显示:在8株携带exoU的铜绿假单胞菌中,有6株存在T83I突变,其中5株存在gyrA(T83I)和parC(S87L)组合突变,并同时具有mexR,ampC和ampR基因突变。RT-PCR结果显示:携带exoU的菌株ampC与ampR基因的相对表达量较标准菌株PAO1明显增高,而携带exoS的菌株中其表达明显降低。mexR基因的相对表达量与二者相反。结论 携带exoU的铜绿假单胞菌具有更多与耐药基因相关的突变,进而导致其对氟喹诺酮类药物以及β内酰胺酶类药物耐药。Objective To investigate the relationship between secretryprotein ExoU ofPseudomonas aeruginosatype Ⅲ secretion system anddrug resistance.Methods Totally, 21Pseudomonas aeruginosastrainswere collected, andexoUandexoSgene carrying status of strains weretested by polymerase chain reaction( PCR). Minimal inhibitoryconcentrations(MICs) of ceftazidime, cefepime, aztreonam, imipenem,levofloxacin and ciprofloxacin were tested by agar dilution method. Themutations of drug resistance genes were analyzed by sequence alignment.Real-time quantitative PCR(RT-PCR) was conducted to detect theexpression of drug resistance-related genes(mexR, ampC andampR)inPseudomonas aeruginosa.Results Among the 21Pseudomonas aeruginosastrains, 8 strains carried theexoUgene, 13 strains carried theexoSgene, and no strains were found to carry bothexoUandexoS simultaneously. The results of antimicrobial susceptibility test showed thatall strains carryingexoUwere resistant to at least three β lactam drugs.M u tat ion analysis demonstrated that 6 strains hadT83Imutation, 5 strains hadgyrA( T83I) andparC( S87L)combination mutations, and also hadmex R,amp Candamp Rgenes mutations among 8 carryingexoU Pseudomonas aeruginosastrains. The results of RT-PCR showed that the expression levels o famp Candamp Rincreased significantlyin Pseudomonas aeruginosastrains carryingexoU, while the expression of the strain carryingexoS decreased significantly. The relative expression of the mexRgene is opposite to that of amp Candamp R.Conclusion There aremore drug resistance genes related mutations in Pseudomonas aeruginosacarrying exoU, which leads to its resistance to fluoroquinolones and β-lactamases.

关 键 词：铜绿假单胞菌 ExoU 耐药性 

分 类 号：R978.1[医药卫生—药品]