Characterization of the genetic diversity in superficial and systemic human isolates of Candida parapsilosis by randomly amplified polymorphic DNA (RAPD).

The application of randomly amplified polymorphic DNA (RAPD) technology for strain delineation of medically important yeasts has proved to be a valuable tool in clinico-epidemiological studies of Candida species. Candida parapsilosis, a form species of the fungi imperfecti, is an emerging pathogen gaining recognition as an opportunistic agent, especially in the immunocompromised. Therefore, 15 clinical isolates of C. parapsilosis obtained from oral, cutaneous and systemic Candida infections were typed by RAPD analysis using four different primers. The primers RSD6 and RSD9 elicited 7 genotypes each, whereas primers RSD7 and RSD12 revealed 6 and 10 genotypes, respectively. When the data were correlated, a higher degree of genomic heterogeneity in systemic isolates was noted compared with the oral and cutaneous isolates, which shared somewhat similar RAPD profiles. However, a single oral isolate (P5) and two systemic isolates (P13 and P15) elicited radically divergent profiles, dissimilar to their counterparts. RAPD study of the latter two isolates with three additional primers (RSD8, RSD10 and RSD11) confirmed the observed genomic disparity. These data substantiate the previous observations on the genomic heterogeneity in C. parapsilosis and point to genetic shifts which may be associated with ecodiversity, as well as the possible existence of distinct genetic groups within this form species.