Revisão sistemática de criptococose em animais domésticos e silvestres, isolamento e caracterização de espécies de Cryptococcus não-neoformans e não-gattii de órgãos de Columba livia

Abstract

Cryptococcus spp. is a basidiomycete, yeast-like and saprobic fungus that causes cryptococcosis in humans and animals. Although the Cryptococcus neoformans and Cryptococcus gattii complexes are the most pathogenic species and are most involved in cryptococcosis, it is noted that there is an increase in the number of infections by other species considered uncommon or rare of Cryptococcus. Pigeons play an important role in the dissemination of C. neoformans through their feces, as well as non-common species of this fungus. In this work, a systematic review was carried out on cryptococcosis in domestic and wild animals, found as manuscript 1. This systematic review found that the largest number of reports of cryptococcosis is in domestic animal species, mainly felines. Among the wild species, ferrets and koalas can be considered important sentinels of the presence of the fungus in the environment. In all species, there is a predominance of pulmonary or neurological involvement and the countries with the highest number of reports are Australia, Brazil, Canada and the United States, with a prevalence of the C. gattii complex VGI and VGII types. Additionally, the present study aimed to report the isolation of non-common species of Cryptococcus from the brain, lung and intestine of Columba livia captured in an urban area of a municipality in southern Brazil, included in the manuscript 2. Columbidaes (n=112) were captured and euthanized. Brain, lung and intestine were analyzed and submitted to mycological culture on niger agar, incubated at 30ºC/10 days. Of these samples, 13 showed growth of colonies compatible with Cryptococcus spp., but without melanin production. Upon direct examination with India ink, rounded to elongated yeasts were observed, with the presence of evident capsules. In the CGB test, the majority (12/13) isolates showed a positive reaction. Molecular characterization was performed by sequencing the ITS1 and ITS2 regions and revealed the identification of non-common species of Cryptococcus, including. Papiliotrema flavescens (n=5), Naganishia diffluens (n=5), Filobasidiella magnum (n=2) and Naganishia randhawai (n=1). Afterwards, brain and lung samples (n=10) were subjected to thermotolerance tests in Sabouraud medium at temperatures -20°C, -5°C, 25°C, 37°C, 42°C and 50°C, where all isolates showed thermotolerance. The present study reports for the first time the isolation of non-common species of Cryptococcus from Columba livia organs, highlighting the importance of pigeons as possible disseminators of occasional or emerging fungal pathogens, since the isolated species express relevant virulence factors.