呼吸道感染中白假丝酵母菌的致病性与细胞外水解酶关系

将84株呼吸道分离的白假丝酵母菌分为致病组和非致病组,采用卵黄培养基法检测细胞外磷脂酶的活力,用牛血清白蛋白琼脂培养基法检法分泌型天冬氨酸蛋白酶的活力,并用RT-PCR的方法检测这2种酶相关基因PLB1和SAP2的表达情况,分析其组间差别,结果表明致病组菌株的分泌型天冬氨酸蛋白酶的活力要高于非致病组(P=0.034<0.05),细胞外磷脂酶活力二组未见差别,致病组的PLB1和SAP2基因的表达均高于非致病组(P<0.05),PLB1和SAP2的表达存在着明显的正相关(r=0.776,P<0.01),提示分泌型天冬氨酸蛋白酶是呼吸道白假丝酵母菌重要的毒力因子,PLB1和SAP2的表达上调可能影响菌株的毒力,这2个基因的表达量有正相关的关系。

Relationship between Pathogenicity and Extracellular Hydrolytic Enzymes by Candida albicans in Infected Respiratory Tract

Eighty four Candida aibicans strains isolated from respiratory tract were divided into pathogenic and non- pathogenic groups and detected with yolk medium for their extracellular phospholipase activity and with bovine serum albumin for their excretive aspartate proteases activity,and detected the expression situation of their pertinent genes PLB1 and SAP2 with RT-PCR to analyse the differences between the two groups.The results showed that proteinase activity of pathogenic group was higher than that of non-pathogenic group(P=0.034<0.05),and there was no difference in phospholipase activity between the two groups.And PLB1 and SAP2 expression in pathogenic group were both higher than those of non-pathogenic group(P<0.05).Furthermore,the expression of PLB1 and SAP2 existed positive correlation,indicating that excretive aspartate protease was the putative virulent factor of C.albicans in respir- atory tract.And the over-expression of PLB1 and SAP2 may have affected the virulence of the strains,and there may be a positive pertinent relation in expression volume of the two genes.