MIKROBIYOLOJI BULTENI, vol.45, no.4, pp.723-728, 2011 (SCI-Expanded)
Candida parapsilosis, which has recently gained increasing importance, is the second most common fungal pathogen isolated from clinical specimens. C.parapsilosis strains exhibiting genetic heterogeneity were previously considered as a complex of three genetically different groups (group I, II, III). However, they have recently been reclassified as new species and named as C.parapsilosis sensu stricto (Grup I), C.orthopsilosis (Grup II) and C.metapsilosis (Grup III). In the present study we aimed to identify C.parapsilosis complex species by PCR-RFLP (Polymerase chain reaction-Restriction fragment lenght polymorphism) method and to determine the distribution of new species isolated from clinical specimens. A total of 68 samples (44 blood, 10 urine, 5 wound, 2 paracentesis fluids, 2 tympanocentesis samples and one of each cerebrospinal fluid, peritoneal fluid, surgical material, oral lesion and nail sample) in which C.parapsilosis had been isolated and identified with API 20C AUX (bioMerieux, France) between October 2005 - July 2009 in the Microbiology Laboratory of Karadeniz Technical University Hospital, in Trabzon, Turkey, were included in the study. Yeast genomic DNA was extracted using the "High Pure PCR Template Preparation Kit" (Roche Diagnostic, USA) and amplification of SADH gene was performed by using specific primers (S1-F sense; 5'-GTTGATGCTGTTGGATTGT-3' ye S1-R antisense; 5'-CAATGCCAAATCTCCCAA-3') with PCR. RFLP method was then applied by digesting PCR product (716 bp) with Banl enzyme (Fermentas, USA). In our study 98.5% (67/68) of the isolates were identified as C.parapsilosis sensu stricto, and 1.5% (1/68) was identifed as C.orthopsilosis, whereas no C.metapsilosis strains were detected. The strain identified as C.orthopsilosis was from a urine specimen and all the blood culture isolates were C.parapsilosis sensu stricto. In conclusion, the inability to differentiate C.parapsilosis complex species by phenotypical and routine tests leads to lack of knowledge in the clinical importance, isolation rates and geographical distribution of these species. Thus, genotypical identification of C.parapsilosis complex species will be the initial step for the arrangement of further studies in that area.