Study of ecological niches from pathogenic yeasts of the species Cryptococcus neoformans and Cryptococcus gattii in Londrina City, PR

Abstract

The pathogenic fungi of the species Cryptococcus neoformans and Cryptococcus gattii could be found in the environment on pigeon guano, soil with pigeon and bird excreta and vegetable material from trees. The aim of this study was analyze the presence of the Cryptococcus pathogenic species on soil with pigeon excreta, soil with vegetable material and decayed wood of trunk hollows of trees from public places in the city of Londrina, PR. Thirty public places were selected from squares, parks and streets in the city centre where samples were collected from: soil with pigeon excreta (n=120), soil with vegetable material (n=120) and decayed wood of trunk hollows of trees (n=120), during June 2009 until March 2010. These collect comprised the seasons: winter, spring and summer, during this period 360 samples were obtained and analyzed in four different times. The species were identified by means of microscopic analysis from culture and their rising on selective medium. A total of five samples were positive to Cryptococcus spp. (1,38%) three were positive to Cryptococcus neoformans (0,84%) in two samples of soil with pigeon excreta, the other one on soil with vegetable material. The samples were originated from a park, a street and a square, placed in the city centre area of Londrina. Cryptococcus gattii was isolated from two samples (0,54%), one in soil with pigeon excreta and another in vegetable material obtained from the soil of two parks that were not protected against sunshine and rain. Cryptococcus spp. was not isolated in none of the 120 swabs samples of decayed wood trunk hollows from the 12 species of trees sampled. The results of the analyses from the environment confirmed the occurrence of the pathogenic species Cryptococcus neoformans e Cryptococcus gattii in places were the human and animal susceptible populations could be exposure to infectious fungi propagators.