Identification of mating types of Cryptococcus gattii by multiplex PCR

Abstract:

[Objective] To establish a multiplex PCR assay on the basis of the SXI1α gene located at the mating type α (MATα) locus and SXI2a gene located at the mating type a (MATa) locus for rapid identification of the mating types of Cryptococcus gattii. [Methods] The primers specific for the alleles of SXI1α gene fragment within the MATα locus of Cryptococcus gattii was designed in combination with the primers specific for the alleles of SXI2a gene fragment within the MATa locus for multiplex PCR analysis of mating types of Cryptococcus gattii. The results were compared with those obtained from regular PCR using primers MFα and STE12α specific for the MATα locus, and primers STE20a and STE3a specific for the MATa locus reported previously, as well as mating assays. [Results] The mating types of all strains including four major genotypes, VGI, VGII, VGIII and VGIV, were successfully identified by multiplex PCR analysis based on the SXI1α and SXI2a genes. However, the mating types of a part of strains could not be determined by regular PCR assays with primer STE12α, STE20a or STE3a; the mating types of 66.7% percent of strains involved here could not be determined due to their inability to mate with the tester strains. [Conclusion] The multiplex PCR analysis is superior to regular PCR or mating assay reported previously.