Molecular epidemiology of isolates of the Cryptococcus neoformans species complex from Spain

Abstract

To study genetic diversity of Cryptococcus neoformans species complex in Spain, 97 isolates of the yeast recovered from human, animal and environmental samples have been analysed using three molecular epidemiological techniques. One of these, URA5 gene fragment length polymorphism (RFLP) analysis, has been previously described as a molecular epidemiology tool. Thus, standard profiles and reference strains have been defined for it. In addition, 5S rDNA/IGS RFLP and [GACA] 4 microsatellite PCR fingerprinting were also used. Our results show five of the previously defined URA5 genotypes with a high frequency (33%) of the VNI type, which is in concordance with other studies. The high presence of VNIII pattern (28.9%) among our strains is remarkable and could be a specific feature of the isolates from our country. 5S rDNA/IGS RFLP showed a low intra-species discriminative power. Three different molecular profiles (S1-3), which showed a good correlation with the different species, varieties and genotypes, were obtained. [GACA] 4 microsatellite PCR-fingerprinting analysis showed a high variability of patterns among the studied strains. Molecular profiles represented in a dendrogram clustered strains in four main groups related with the source of the yeast and also in concordance with some of the described genotypes (VNI-IV and VGI).