Recovery of environmental Cryptococcus neoformans and Cryptococcus gattii in Cucuta and association with clinical isolates

Objective. Isolate, identify and molecularly characterize pathogenic Cryptococcus isolates for humans from environmental and clinical samples from the city of Cucuta. Materials and methods. A total of 1300 samples were collected from 446 trees of 10 different species in 10 public areas of Cucuta. Concomitantly, clinical isolates of Cryptococcus neoformans were obtained (June 2016-June 2017). The samples were cultivated in Guizottia abysinica seed medium and were then biochemically identified and characterized by PCR fingerpinting and RFLP of the URA5 gene. Results. C. neoformans displayed an environmental prevalence of 4.3% (19 positive individuals), and that of C. gattii was 0.2% (1 positive individual); this yielded a total of 20 Cryptococcus-positive trees and 21 isolates (two from the same individual). Santander Park registered 47.6% of the global prevalence (10/21 isolates), followed by La Victoria Park with 23.8% (5/21 isolates), corresponding to C. neoformans. One C. gattii isolate was collected from a Ficus benjamina tree located in Mercedes Abrego Park. Genotypic analysis revealed the presence of C. neoformans var. grubii VNI in 85.7% of environmental isolates as well as 100% of clinical isolates. VNII and VGII molecular types represented 9.5% and 4.8% of the environmental isolates, respectively. Conclusions. The longitudinal sampling of previously reported environmental niches of the fungus reveals its presence and suggests that permanent monitoring is required both in the environment and in patients, especially in endemic areas of the city.