Genetic Diversity of Candida spp. Isolates Colonizing Twins and Their Family Members.

A wide range of options for studying Candida species are available through genetic methods. Twins, particularly monozygotic ones and their families may be fitting subjects for studying those microorganisms. The question is: How specific can yeast flora be in an individual? The study aimed to analyze the strain relatedness among commensal yeasts isolated from various parts of the bodies of healthy people and to compare correlations between the genotypes of the isolates. Yeasts were isolated from 63 twins and their family members ( n = 25) from the oral cavity, anus, interdigital space and navel. After species identification, Candida albicans ( n = 139), C. parapsilosis ( n = 39), C. guilliermondii ( n = 25), C. dubliniensis ( n = 11) and C. krusei ( n = 9) isolates were analyzed using the random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) optimization method. The similarities between the strains were calculated based on the Dice (Sab) coefficient and are displayed graphically as dendrograms. Using cluster analysis, the following relatedness was distinguished: 13 genotypes and three unique (Un) patterns among C. albicans ; 10 genotypes and four Un patterns among C. parapsilosis ; three genotypes and one Un pattern among C. guilliermondii and C. dubliniensis ; and three genotypes among C. krusei isolates. The presence of identical, similar or both genotypes among the strains isolated from family members shows the transmission of yeasts between ontocenoses in the same person and between individuals. The similarity between the genotypes of C. albicans , C. guilliermondii , C. dubliniensis and C. krusei was more remarkable than between the genotypes of C. parapsilosis in the strains isolated from ontocenoses of the same individual and their family members. The degrees of genetic similarity between Candida spp. strains isolated from monozygotic twins and those obtained from their relatives did not differ.