Molecular Identification of Candida Species in Patients with Candidiasis in Birjand, Iran, Using Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) Assay

In recent years, the incidence of opportunistic fungal infections such as candidiasis, especially in immunocompromised patients, has considerably increased. Rapid and accurate identification of candida isolates is necessary for effective antifungal therapy and hospital infections management. In this study, polymerase chain reaction (PCR)-based technique using a one-enzyme restriction fragment length polymorphism (RFLP) was used for discrimination of candida species.

98 yeast strains were obtained from 90 patients with candidiasis during one-year period, from December 2013 to December 2014, in Birjand city, Iran. Clinical samples were cultured on Sabouraud dextrose agar with choramphenicol at 32°C and CHROMagar™ at 35°C for 48 hours to produce species-specific colors. In next stage, identification of Candida species was performed using PCR-RFLP method with the MspI restriction enzyme.

Totally, 98 candida isolates successfully were isolated from different clinical samples and identified via PCR-RFLP method using MspI. The age group of infancy to 10-year-old had the highest prevalence of candidiasis. In clinical samples, most of the Candida isolates were isolated from urine (83.86%). The most commonly identified species were Candida albicans in 41 cases (41.84%), Candida glabrata in 16 case (16.32%), Candida tropicalis in 12 cases (12.24%), Candida krusei in 10 cases (10.2%), Candida parapsilosis in 8 cases (8.08%), Candida Lusitania in 7 cases (7.14%), and Candida kefyr and Candida guilliermondii each one in 2 cases (2.04%).

PCR-RFLP assay with restriction enzyme MspI is an easy, rapid, and reliable method for identification of Candida species.