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假丝酵母是临床常见的条件致病菌 ,抗生素的滥用及放化疗和免疫抑制剂广泛使用 ,使得假丝酵母的感染机会增加 ,针对常见的吡咯类抗真菌药的耐药现象逐年增加。其耐药途径较多 ,包括细胞膜对药物的通透性下降 ,药物在细胞内降解 ,甾醇合成路径的改变 ,细胞膜的排出泵作用增强 ,甾醇合成酶的性质变化等。与假丝酵母耐药性相关的细胞色素 P- 45 0羊毛甾醇脱甲基酶的基因存在 4种改变 :(1)点突变 ;(2 )基因过度表达 ;(3)基因扩增 ;(4 )基因转换或有丝分裂重组 ,导致靶酶的生物学特性变化 ,及其与假丝酵母耐药性的相互关系。表明假丝酵母编码靶酶的基因的变化可导致靶酶一级结构改变和空间构象变化 ,影响药物对靶酶的亲和性 ,或导致靶酶量的变化 ,影响药物的作用 ,产生耐药性。
Candida is a common clinical pathogenic bacteria, the abuse of antibiotics and radiotherapy and immunosuppressive agents are widely used, making Candida infection increased opportunities for the common azole antifungal drug resistance increased year by year. There are many ways of drug resistance, including the decrease of cell membrane permeability to drugs, the degradation of drugs in cells, the change of sterol synthesis pathway, the enhancement of membrane pump and the change of the properties of sterol synthase. There are four changes in the gene for cytochrome P-45 0 lanosterol demethylase associated with Candida resistance: (1) point mutation; (2) gene overexpression; (3) gene amplification; (4) ) Gene transfer or mitotic recombination, resulting in changes in the biological characteristics of the target enzyme and its relationship with Candida resistance. The results indicated that the change of the gene encoding Candida albicans could lead to the change of the primary structure and the spatial conformation of the target enzyme, the affinity of the drug to the target enzyme, or the change of the target enzyme amount, the effect of the drug and the drug resistance Sex.