Typing of Candida albicans isolates by sequence analysis of the cytochrome b gene and differentiation from Candida stellatoidea

Including type strains, mitochondrial cytochrome b genes of 32 strains of Candida albicans and 6 strains of Candida stellatoidea, presently treated as a synonym for C. albicans, were partially sequenced. Analysis of 396-bp nucleotide sequences of the strains under investigation divided C. albicans isolates into three types: type I, type II, and type III; however, strains of C. stellatoidea represented distinct type IV isolates. Deduced amino acid sequences of type I, type II, and type III were identical and differed from that of type IV by one amino acid. Genotypes (rDNA type) of the test strains were also checked. Cytochrome b typing did not correlate with genotyping, and different genotypes occurred for one cytochrome b type. This study shows that cytochrome b gene sequences are useful for analyzing the genetic relatedness of C. albicans isolates and effective for differentiating C. stellatoidea from C. albicans.