Prevalence, Genetic Structure, and Antifungal Susceptibility of the Cryptococcus neoformans/C. gattii Species Complex Strains Collected from the Arboreal Niche in Poland

Abstract

Fungi belonging to the Cryptococcus neoformans/C. gattii species complex (CNGSC) are etiological agents of serious and not infrequently fatal infections in both humans and animals. Trees are the main ecological niche and source of potential exposition concerning these pathogens. With regard to epidemiology of cryptococcosis, various surveys were performed worldwide, enabling the establishment of a map of distribution and genetic structure of the arboreal population of the CNGSC. However, there are regions, among them Central and Eastern Europe, in which the data are lacking. The present study shows the results of such an environmental study performed in Wrocław, Poland. The CNGSC strains were detected in 2.2% of the tested trees belonging to four genera. The obtained pathogen population consisted exclusively of C. neoformans, represented by both the major molecular type VNI and VNIV. Within the tested group of isolates, resistance to commonly used antimycotics was not found, except for 5-fluorocytosine, in which about 5% of the strains were classified as a non-wild type.

Antifungal Resistance in Cryptococcal Infections

“…In general, environmental isolates are less susceptible to fluconazole among the agents used, in comparison to the clinical isolates (e.g., fluconazole: 0.25–64 mg/L vs. 0.25–8 mg/L); this tendency was particularly observed with VNI strains from the environment. Similar findings have also been reported from Poland, Thailand, India, Cuba, and other areas [ 143 , 144 , 145 , 146 , 147 , 148 , 149 , 150 , 151 , 152 , 153 ]. These data point out the occurrence of primary resistance among environmental isolates of both C. neoformans and C. gattii.…”