Gene polymorphism and drug sensitivity of Candida glabrata associated with vulvovaginal candidiasis in women of childbearing age / 中华检验医学杂志

ABSTRACT

Objective@#To investigate genotypes and drug susceptibility of the 100 strains of Candida glabrata isolated from 100 women (including 50 pregnant women) in order to study the drug-resistance and gene polymorphism, and to investigate the correlation of drug-resistance, gestation and gene polymorphism.@*Methods@#Multilocus sequence typing (MLST) technique was introduced to identify sequences of 6 housekeeping genes from 100 isolates of Candida glabrata. The results were compared with sequence information in MLST databases by Clustalx software to determine a strain allelic profile and sequence type (ST). Drawing the phylogenetic tree by weighted paired group average method and the minimal spanning tree method of MEGA6.0 software, the microevolution and relationship between different strains were analyzed. ATB FUNGUS semi-automatic system was used to test the drug susceptibility. Fisher analysis method was used to analyze the correlation between the genotypes and pregnancy.Ridit analysis method was used to analyze the correlation between the genotypes and drug susceptibility.@*Results@#The 100 isolates belonged to 34 clone sequences. There were 53 isolates belonged to ST-7 ( 26 isolates of pregnancy), 7 isolates belonged to ST-3 (3 isolates of pregnancy), 6 isolates belonged to ST-19 (5 isolates of pregnancy ), 3 isolates belonged to ST-15 (1 isolate of pregnancy), 2 isolates belonged to ST-10 (2 isolates of pregnancy), 1 isolate belonged to the other types of ST. Total of 100 isolates of Candida glabrata were 100% sensitive to fluorocytosine and amphotericin. The effect of itraconazole was poor with the sensitive rate of 20%. The resistance rates of fluconazole and voriconazole were 4% and 1% respectively. All genotypes were sensitive to voriconazole except ST-X1. In the correlation between genotype and itraconazole resistance, ST-7 as the standard group, the Ridit values in the group of ST-15, ST-19 and other types of ST were not included the mean Ridit value of the standard group in itraconazole (0.5). The system evolution tree was built using the neighbor-joining method (NJ) . All genotypes could be divided into 3 groups, as Ⅰ, Ⅱ, Ⅲ. Group Ⅰ had 44 cases, group Ⅱ had 53 cases , group Ⅲ had 3 cases . All the collected clinical strains had small genetic distances during molecular evolution.@*Conclusions@#ST-7 was the dominant genotype in Guiyang. No correlation between different STs and patients′ pregnancy was found. The different drug susceptibility in itraconazole between ST-7, ST-15, ST-19 and other STs were found. The Candida glabrata associated with VVC showed highly discrimative diversity. However, the phylogenic analysis exhibited genetic similarity among the strains studied.(Chin J Lab Med, 2018, 41 596-600)