Protease and phospholipase production of Cryptococcus neoformans, C. gattii and C. laurentii isolates

Abstract

Cryptococcosis is an opportunistic systemic mycosis, which may affect humans and
various animal species, especially in cases of immunosuppression. The infection
may be acquired through inhalation and by hematogenous route; the yeast has the
ability to reach and colonize the central nervous system. The aim of this survey was
the isolation of the Cryptococcus neoformans yeast from central nervous system of
dogs in Rio de Janeiro city. Periodic collections were made from brain samples at the
Rabies Diagnosis Laboratory in Instituto Municipal de Medicina Veterinária Jorge
Vaitsman in Mangueira, Rio de Janeiro. The isolation, the identification of this yeast
and the evaluation of protease and phospholipase production were performed at the
Laboratory of Environmental and Pathogenic Yeasts of the Universidade Federal
Rural do Rio de Janeiro. A medium containing bovine serum albumin was used to
evaluate protease production and to evaluate the production of phospholipase. The
medium used consisted of egg yolk and CaCl2. According to the results obtained
of the 166 clinical samples from dogs, we found four positive samples; one of
these was positive for Cryptococcus laurentii, two were positive for Cryptococcus neoformans; and one for Cryptococcus gattii; all of them produced protease and
phospholipase.