呼吸道感染中白假丝酵母菌细胞外水解酶和耐药性对菌株毒力的影响

发布时间：2018-01-07 06:04

本文关键词：呼吸道感染中白假丝酵母菌细胞外水解酶和耐药性对菌株毒力的影响　出处：《福建医科大学》2007年硕士论文　论文类型：学位论文

【摘要】： 目的分析呼吸道白假丝酵母菌细胞外磷脂酶B和分泌型天冬氨酸蛋白酶活力及其基因表达对菌株毒力的影响;分析呼吸道白假丝酵母菌对唑类抗真菌药物的耐药情况与耐药基因的表达关系;分析白假丝酵母菌毒力与耐药性的关系。方法①收集临床呼吸道白假丝酵母菌菌株,通过培养鉴定将菌株分为致病组和非致病组;②采用卵黄培养基法检测菌株细胞外磷脂酶B的活力,用牛血清白蛋白琼脂培养基法检测分泌型天冬氨酸蛋白酶的活力,分析组间差别;③用NCCLS M27-A方案中的微量液基稀释法检测菌株对氟康唑和伊曲康唑的最小抑菌浓度(MIC),比较菌株组间的耐药性差别;④用半定量RT-PCR的方法检测细胞外磷脂酶B和分泌型天冬氨酸蛋白酶相关基因PLB1和SAP2,以及耐药相关基因CDR1和MDR1的mRNA表达,分析菌株的毒力和耐药性与相关基因表达以及耐药性与耐药基因的关系;⑤对CDR1、MDR1、PLB1和SAP2的基因表达进行相关分析。结果共收集了84株呼吸道临床菌株,非致病组有28株,致病组有56株;致病组分泌型天冬氨酸蛋白酶的活力要高于非致病组,细胞外磷脂酶活力未见差别;致病组菌株的PLB1和SAP2的mRNA的量均高于非致病组;二组菌株之间,氟康唑和伊曲康唑的耐药性和耐药相关基因的转录无差别;呼吸道白假丝酵母菌对伊曲康唑的耐药率要高于氟康唑;MDR1与PLB1、MDR1与SAP2、PLB1和SAP2基因在mRNA的水平上有明显的正相关。结论分泌型天冬氨酸蛋白酶活力是呼吸道白假丝酵母菌重要的毒力因子,PLB1和SAP2的mRNA转录水平的上调可能影响菌株的毒力,呼吸道菌株对伊曲康唑的耐药率要高于氟康唑,菌株的毒力与耐药性和耐药相关基因的转录无关;MDR1、PLB1和SAP2基因调控在mRNA的水平可能有相关性。
[Abstract]:Objective to analyze the effects of extracellular phospholipase B and secretory aspartate protease activity and gene expression on virulence of Candida albicans. To analyze the relationship between the resistance of Candida albicans to antifungal agents and the expression of resistance genes. The relationship between virulence and drug resistance of Candida albicans was analyzed. Methods 1 strains of Candida albicans in clinical respiratory tract were collected and identified by culture. The strains were divided into pathogenic group and non-pathogenic group. 2the activity of extracellular phospholipase B was detected by yolk medium method, and the activity of secretory aspartic protease was detected by bovine serum albumin Agar medium. 3 the minimal inhibitory concentration of fluconazole and itraconazole was detected by microdilution method in NCCLS M27-A scheme, and the drug resistance of strains was compared. 4 the extracellular phospholipase B and secretory aspartic protease related gene PLB1 and SAP2 were detected by semi-quantitative RT-PCR. The relationship between virulence and drug resistance and the expression of related genes and the relationship between drug resistance and drug resistance genes were analyzed. 5 correlation analysis of the gene expression of CDR1, MDR1, PLB1 and SAP2. Results A total of 84 clinical strains of respiratory tract were collected. There were 28 strains in non-pathogenic group and 56 strains in pathogenicity group. The activity of secretory aspartate protease in pathogenic group was higher than that in non-pathogenic group, but there was no difference in extracellular phospholipase activity. The amount of mRNA of PLB1 and SAP2 in pathogenic group was higher than that in non-pathogenic group. There was no difference in drug resistance and transcription between fluconazole and itraconazole. The resistance rate of Candida albicans to itraconazole was higher than fluconazole. There was a significant positive correlation between MDR1 and PLB1MDR1 and SAP2PLB1 and SAP2 genes at the mRNA level. Conclusion the activity of secretory aspartate protease is an important virulence factor of Candida albicans. The up-regulation of mRNA transcription level of PLB1 and SAP2 may affect the virulence of the strain. The resistance rate of respiratory tract strains to itraconazole was higher than that of fluconazole, and the virulence of the strains was not related to drug resistance and transcription of drug-resistance related genes. The regulation of MDR1 PLB1 and SAP2 gene may be related to the level of mRNA.
【学位授予单位】：福建医科大学
【学位级别】：硕士
【学位授予年份】：2007
【分类号】：R378

【参考文献】