光滑念珠菌MSH2基因突变与氟康唑耐药的研究  

Analysis of relationship between MSH2 gene mutation and fluconazole resistance in Candida glabrata

作　　者：刘赟蕾 宫婷婷[1] 王中新[1] Liu Yunlei;Gong Tingting;Wang Zhongxin(Dept of Clinical Laboratory,The First Affiliated Hospital of Anhui Medical University,Hefei 230022)

机构地区：[1]安徽医科大学第一附属医院检验科,合肥230022

出　　处：《安徽医科大学学报》2019年第4期622-625,共4页Acta Universitatis Medicinalis Anhui

基　　金：安徽省高校省级自然科学研究项目(编号:KJ2015A337)

摘　　要：目的分析临床分离157株光滑念珠菌对5种抗真菌药物的耐药率,探讨临床分离的光滑念珠菌MSH2基因突变与氟康唑耐药的关系。方法①收集自真菌感染患者中分离的光滑念珠菌157株,统计对5种抗真菌药物的耐药情况。②从上述菌株中随机挑取19株氟康唑耐药菌株、15株剂量依赖性敏感(S-DD)菌株以及23株敏感菌株,用微量稀释法对药物敏感性进行验证,对MSH2基因进行Sanger测序检测,并将测序结果与Genbank中已发表的序列进行比对,分析每组MSH2基因突变频率及相关突变位点。结果①157株光滑念珠菌对伊曲康唑耐药率最高,为27.4%,对氟康唑耐药率为22.9%,对伏立康唑、两性霉素B耐药率分别为5.7%、2.5%,所有菌株对5-氟胞嘧啶不耐药。②与敏感组比较,耐药组、S-DD组MSH2基因突变频率显著升高,差异有统计学意义(P<0.016 7)。检测到MSH2基因存在G622A/A2669T、G715T这3个突变位点,对应P208S/N890I、V239L 3个氨基酸置换位点;且P208S/N890I仅出现在耐药菌株中。结论临床分离的光滑念珠菌对唑类耐药率比两性霉素B、5-氟胞嘧啶高;光滑念珠菌MSH2基因突变与氟康唑耐药有一定关系。Objective To analyze the resistance rate of 157 Candida glabrata clinical strainsto five antifungal drugs,and to explore the relationship between MSH2 gene mutation and fluconazole resistance in Candida glabrata clinical strains.Methods①A total of 157 Candida glabrata strains from patients with fungal infections were collected.The resistance to five antifungal drugs was statistically analyzed.②Fluconazole-resistant(n=19),dose-dependent sensitive(S-DD)(n=15)and susceptible isolates(n=23)were randomly collected from the above 157 strains,and verified the drug sensitivity by microdilution method.Using Sanger method sequenced the MSH2 gene,and the sequencing results were compared with the published sequences in Genbank,and analyze of the frequency of mutations and related mutation sites in MSH2 gene.Results①Of the 157 Candida glabrata strains,27.4%,22.9%,5.7%,2.5%were resistance rate to itraconazole,fluconazole,voriconazole and amphotericin B,respectively.All strains were sensitive to 5-fluorocytosine.②Compared with susceptible isolates(n=23),the mutation frequency of MSH2 gene in fluconazole-resistant isolates(n=19)and S-DD isolates(n=15)was significantly increased,and the difference was statistically significant(P<0.016 7).The three mutation sites of G622 A/A2669 T and G715 T were detected in MSH2 gene,corresponding to three amino acid substitution sites of P208 S/N890 I and V239 L;and P208 S/N890 I only appeared in drug-resistant strains.Conclusion 157 Candida glabrata clinical strains have higher resistance to azoles than amphotericin B and 5-fluorocytosine.The mutation of MSH2 gene of Candida glabrata has a certain relationship with fluconazole resistance.

关 键 词：光滑念珠菌 耐药机制 DNA错配修复 氟康唑 

分 类 号：R379.4[医药卫生—病原生物学]