Strain typing of Candida alhiranstargeting to repeat sequences in each chromosome

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Candida albicans is the most etiologic yeast species of candidiasis in both healthy and immunocompromized individuals. For surveillance and prevention of candidiasis, it is important to discriminate C. albicans at the strain level. PCRs targenting 25S rDNA and ALT repeat element have evaluated in this study. Furthermore, fragment analysis of microsatellite repeats was adapted to further genotype study of C. albicans at the strain level. One hundred-seventy nine clinical isolates were grouped into genotypes A(92 isolates), B(37 isolates)and C(50 isolates)on the basis of their 25S rDNA, and each was further classified into 5 types(types 3, 4,3/4,2/3/4 and 3/4/5)by PCR amplification targeting ALT repeats. Type 3 C. albicans constituted the majority of isolates in any genotypes(66.3% for genotype A, 78.3% for genotype B and 72.0% for genotype C).The fragment analysis of microsatellites using CDC3, HIS3, CAI and CAIII allowed to discriminate the strains, which showed the same electophoretic patterns in the PCRs using 25SINT, P-II and AS-I. Conversely, the PCRs using 25SINT, P-II and AS-I discriminated the strain that showed identical scores in the fragment analysis. These results indicate that a combination of three different systems is useful for genotyping of C. albicans at the strain level(DP=99.99). Furthermore, the fragment analysis using 117 strains of C. albicans isolated in Brazil, Japan and Thailand suggested the presence of genotypes specific for each country