热带念珠菌的分布特征及其耐药性与ERG11和UPC2表达的关系

Distribution of Candida tropicalis and its drug resistance correlated to ERG11 and UPC2 expression

目的分析2016年至2018年成都医学院第一附属医院临床分离热带念珠菌的分布特征和耐药性,以及ERG11和UPC2基因表达与唑类药物耐药的关系。方法用沙保罗培养基、科玛嘉念珠菌显色培养基及法国ATB微生物鉴定和药敏分析仪对该院临床分离的热带念珠菌进行培养、鉴定及药敏试验,再提取收集菌株的总RNA,用实时荧光定量聚合酶链反应对热带念珠菌ERG11和UPC2基因mRNA进行相对定量检测。结果2016年至2018年临床分离的念珠菌共2276株,其中热带念珠菌238株,科室主要分布于呼吸内科和重症监护室,样本类型以气道分泌物为主。热带念珠菌对氟康唑、伊曲康唑及伏立康唑的耐药率逐年增加。耐药组的ERG11和UPC2 mRNA相对表达水平分别为1.58±0.90和1.40±0.92,均显著高于敏感组的0.48±0.26和0.45±0.27,差异均有统计学意义(均P<0.001),且耐药组两基因表达呈线性正相关(r=0.571,P<0.05)。结论热带念珠菌ERG11和UPC2基因的过度表达能够增加抗真菌药物的耐药性。针对临床的高危患者,若能够常规检测ERG11和UPC2基因,可及时为临床合理应用抗真菌药物提供理论依据。

Objective To analyze the distribution characteristics and drug resistance of clinical Candida tropicalis and investigate the correlation between the expression levels of ERG11,UPC2 genes and azole resistance in the First Affiliated Hospital of Chengdu Medical College from 2016 to 2018.Methods The Candida tropicalis were cultured and identified by the Sabouraud Agar Medium,CHROM Agar Candida and France bio Merieux ATB tester,the drug sensitive tests of Candida tropicalis were also detected in France bio Merieux ATB tester.Then the total RNA of the collected strains was extracted,the ERG11 and UPC2 mRNA expression levels of Candida tropicalis were quantitatively analyzed by real-time polymerase chain reaction.Results From 2016 to 2018,there were 2276 clinical isolates of Candida,including 238 strains of Candida tropicalis.The departments were mainly distributed in the department of respiratory medicine and intensive care unit,the specimen type was mainly based on airway secretion.The resistance rates of Candida tropicalis to fluconazole,itraconazole and voriconazole increased year by year.The relative expression levels of ERG11 mRNA(1.58±0.90)and UPC2 mRNA(1.40±0.92)in fluconazole resistant group was significantly higher than that in sensitive group[ERG11 mRNA(0.48±0.26),UPC2 mRNA(0.45±0.27);all P<0.001],and there was a significant linear positive correlation between the two genes in fluconazole resistant group(r=0.571,P<0.05).Conclusion Overexpression of ERG11 and UPC2 genes in Candida tropicalis could increase the resistance of antifungal drugs.If the ERG11 and UPC2 genes can be routinely detected among high-risk clinical patients,it will provide a theoretical basis for the rational application of antifungal drugs.