Kan Kültürlerinden İzole Edilen Candida parapsilosis Kompleks Türlerinin Eşey Tipi (MTL) Genotiplerinin Belirlenmesi

Abstract

Objective: Candida parapsilosis is one of the most common species after Candida albicans among the causative factors of systemic candidosis. In Candida species, determination of the cell identity and the sexual reproduction process take place under the control of the mating type (MTLα) locus. This region has completely different sequences in two different mating types (a and α) and is called an idiomorph. While the MTLa idiomorph encodes the transcription factors a1 and a2, MTLα encodes α1 and α2 proteins. Apart from these genes, both idiomorphs have a or α versions of PAB, OBP, and PIK genes, whose functions in sexual reproduction are unknown. On the other hand, up to now neither Candida parapsilosis nor the closely related species Candida orthopsilosis or Candida metapsilosis has been reported to have sexual cycles. While C. orthopsilosis was found to have a mixed population structure harboring MTLa and MTLα homozygous and MTLa/MTLα heterozygous genotypes in realized studies, the majority of C. metapsilosis isolates were MTLa/MTLα heterozygotes. Nevertheless, all C. parapsilosis isolates analyzed were found to be of a single mating type (MTLa). Method: This study was aimed to determine the MTL genotypes of C. parapsilosis isolates of Turkey origin, and 167 blood isolates were used for this purpose. The isolates identified as C. parapsilosis by PCR-amplifying and sequencing the ITS region were screened for MTLa1, MTLa2, MTLα1 and MTLα2 genes. Results: Only MTLa1 and MTLa2 genes were detected in PCR; therefore, all isolates were determined to have the MTLa genotype. Conclusion: When the results are assessed with previous findings, it could be inferred that the MTLα mating type of C. parapsilosis has been lost or extremely rare in yet unanalyzed geographical regions.