Evaluation of Prevalence of the New Candida Species (C. Orthopsilosis and C. Metapsilosis) among C. Parapsilosis Group Isolated from Patients by PCR-RFLP of SADH Gene in Iran

Candida orthopsilosis and C. metapsilosis are recently introduced species that phenotipically indistinguishable from C. parapsilosis. In the present study, we evaluated the incidence and distribution of C. orthopsilosis and C. metapsilosis among 111 C. parapsilosis, isolated from different body locations by molecular methods.

Yeast genomic DNAs were extracted from 935 isolates using Whatman FTA filter matrix technology from fresh cultures. First, ITS region of yeasts, were amplified by ITS1 and ITS4 primers, then Candida parapsilosis group were identified with digestion by MspI. SADH gene was amplified and three species of Candida including C. parapsilosis, C. orthopsilosis and C. metapsilosis were differentiated with digestion by NlaIII enzyme.

Totally 111 isolates were identified as Candida parapsilosis among them, 18 isolates (16.2%) were identified as C. orthopsilosis and 93 isolates (83.7%) as C. parapsilosis. No isolates were identified as C. metapsilosis. The most isolates of C. orthopsilosis, were obtained from nail.

C. ortopsilosis is not a rare species in Iran and it seems that a significant amounts of Candida strains which are considered as C. parapsilosis might be C. ortopsilosis.