Genotype analysis of Candida albicans isolates obtained from different body locations of patients with superficial candidiasis using PCRs targeting 25S rDNA and ALT repeat sequences of the RPS

Abstract

Several molecular biology-based genotyping techniques have been adapted for studying the molecular characteristics of Candida albicans strains, which constitute the majority of the etiologic agents in candidiasis. Recently, we reported a PCR system targeting 25S rDNA and ALT repeat sequences in the repetitive sequence (RPS) for genotyping of C. albicans. To assess the potential of 25S rDNA and RPS-based genotyping for studying the molecular epidemiology of C. albicans, and define the genotypic relationship of C. albicans between invasive and non-invasive lesions in the same individual. C. albicans strains were isolated from infected lesions and commensal sites, such as oral mucosa and/or feces, of patients with superficial candidiasis. The genomic DNAs were amplified by PCRs using P-I and P-II to determine the 25S rDNA- and RPS-based genotypes of the isolates. Genotype A:3 C. albicans constituted the majority of the isolates, followed by A:3/4 and B:3 C. albicans. There was usually one genotype of C. albicans per person. The genotypes of infected lesion isolates and non-infected oral mucosa and/or feces isolates were identical in the same individual, even in serially isolated C. albicans. The results indicate that our combined PCR technique using P-I and P-II is a potential tool for molecular typing of C. albicans, and reveal that the genotypes of isolates are identical in the same individual, independent of the infective and non-infective phases or the body location.