Molecular analysis and in vitro susceptibility profiling of some clinically important Candida spp. to the common antifungal drugs

Abstract

This study aimed to determine the in vitro susceptibility profiles of a group of Candidaspecies to some of the common antifungal drugs in clinical use. Thirty nine Candidaisolates were collected from the blood of immunocompromised patients with cancer. Isolates were cultivated on CHROMagar, identified using API20C kit and the ID was confirmed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. Candida albicans was found to be the most frequently isolated yeast (46%) in comparison to the other species Candida krusei (28%), Candida tropicalis(13%), Candida glabrata (10.4%) and Candida parapsilosis (2.6%). PCR based analysis of the transposable intron in the 25S rDNA of C. albicans isolates revealed that 72, 17 and 11% of the isolates belonged to genotype A, B and C, respectively. Susceptibility testing of the Candida isolates against five antifungal drugs (amphotericin B, 5-flucytosine, miconazole, itraconazole and fluconazole) was carried out using the broth microdilution method, and The MICs values for all five antifungal drugs was determined. The susceptibility profiles indicated that all isolates were susceptible to amphotericin B; most of the isolates were susceptible to 5-flucytosine and miconazole, while the susceptibility of the Candida isolates towards fluconazole and itraconazole varied depending on the species. Key words: Clinical candidaisis, immunocompromised patients, susceptibility tests, polymerase chain reaction-restriction fragment length polymorphism assay, genotyping.