多重耐药纹带棒状杆菌的耐药机制研究  

Research on resistance mechanism of the multidrug-resistant Corynebacterium striatum strains

作　　者：李科[1] 张德纯[1] 张名均[1] 杨金梅[1] 杨晓容[1] 刘胜男[1] 

机构地区：[1]重庆医科大学基础医学院病原生物学教研室,分子医学与肿瘤研究中心,重庆400016

出　　处：《中国抗生素杂志》2014年第5期361-364,共4页Chinese Journal of Antibiotics

摘　　要：目的研究多重耐药纹带棒状杆菌(MDR-Cs)的耐药机制。方法用微量肉汤稀释法检测临床分离的48株MDR-Cs的最低抑菌浓度(MIC);聚合酶连反应检测菌株的核糖体甲基化酶基因(ermX)、核糖体保护蛋白基因(tet(W))、DNA螺旋酶A亚单位基因(gyrA)和接合型转座子Tn1545整合酶基因(intTn)、L,D-转肽酶基因(ldt1/2),并测序分析。结果根据2007年CLSI M45文件的标准检测14种抗菌药物的敏感性,所有被测菌株均表现出多重耐药;ermX、tet(W)和intTn基因检出率分别为93.8%、100%和100%;与标准菌株比对,所有菌株的gyrA基因序列均表现为以间隔3个氨基酸的丝氨酸和天冬氨酸分别突变为苯丙氨酸和丙氨酸的双点突变;未检出ldt1/2。结论中国重庆地区的MDR-Cs对青霉素、Ⅲ、Ⅳ代头孢菌素、四环素、喹诺酮类和复方磺胺甲噁唑表现出全耐药,对万古霉素、利奈唑胺表现为全敏感;菌株介导ermX和tet(W)基因分别对红霉素和四环素耐药,介导gyrA基因双位点突变对喹诺酮类高水平耐药,所有菌株均携带转座子Tn1545整合酶intTn基因。Objective To research the resistance mechanism of the multidrug-resistant Corynebacterium striatum strains （MDR-Cs）. Methods By broth micro-dilution method to test the minimum inhibitory concentrations （MIC） of 48 strains of the MDR-Cs isolated from the infectious patients; The methylase gene（ermX）, ribosomal protection protein gene（tet（W））, the DNA helicase A （gyrA）and the integrase of the conjugative transposon Tn1545 （intTn） were detected by polymerase chain reaction（PCR）, the PCR products were sequenced and analysed. Result The antibiotic susceptibility of 14 different antibiotics was tested based on CLSI M45 document 2007. All strains of the Corynebacterium striatum showed multidrug-resistant phenotype; the relevance ratio of ermX, tet（W） and intTn was respectively 93.8%, 100% and 100%. All the strains presented a double mutation with changes from Ser to Phe and from Asp to Ala where three amino acid lie between. Conclusion The phenotype of the MDR-Cs in Chongqing China showed completely resistant to penicillin, third and fourth-generation cephalosporins, tetracyclinem, quinolone and sulfamethoxazole-trimethoprim,while completely susceptible to vancomycin and linezolid; Strains were resistant to erythromycin and tetracycline respectively by ermX and tetW, while were high-level resistant to quinolone by double mutation in gyrA; all strains have in tTn gene which is the integrase of the conjugative transposon Tn1545.

关 键 词：多重耐药 纹带棒状杆菌 耐药机制 

分 类 号：Q939.92[生物学—微生物学]