[Investigation of the presence of Cryptococcus spp. in eucalyptus trees by using sedimentation and swabbing methods]

Yeasts of the genus Cryptococcus are life-threatening microorganisms that cause cryptococcosis in both immunocompromised and immunocompetent humans and animals worldwide. In the nature, Cryptococcus species exist in eucalyptus trees and other species of trees as well as in the soil contaminated with pigeon droppings. The aim of this study was to investigate the presence of Cryptococcus spp. in the samples collected from eucalyptus trees by classic sedimentation and swabbing methods. Regarding these microorganisms, stem hollows, blossom and leaf samples from 61 trees (more than 95% were Eucalyptus camaldulensis) found in and around Adana province (located at Mediterranean region of Turkey) have been examined in June 2006 and June 2007 periods. The samples were then evaluated in terms of the growth of mucoid, dampish and brownish colonies after inoculation onto three media (Guizotia abyssinica birdseed agar with 0.1%, 0.01% and without diphenyl) and incubation in aerobic conditions at 28 degrees C for three weeks. However, no Cryptococcus spp. has been isolated from any of the samples. It was suggested that other species of trees and environmental samples should be examined for the existence of yeast fungi, so that more extensive epidemiological data could be obtained.