Características histomorfológicas e histoquímicas determinantes no diagnóstico da criptococose em animais de companhia

Abstract

Pesq. Vet. Bras. 34(3):261-269, março 2014 261 RESUMO.-Sete casos de criptococose (seis gatos e um cão) foram estudados para estabelecer as características histomorfológicas e histoquímicas determinantes no diagnóstico histopatológico dessa condição. Os dados complementares relacionados à epidemiologia, aos aspectos clínicos, à localização das lesões e às alterações macroscópicas foram obtidos dos protocolos de necropsias e biópsias. Na histologia, as leveduras foram observadas no interior de macrófagos ou livres no parênquima, associadas à reação inflamatória linfo-histioplasmocítica que variou de escassa a acentuada. Pela técnica de hematoxilina-eosina (HE) as leveduras eram arredondadas, com célula central contendo um núcleo, circundada por um halo claro (cápsula geralmente não corada). As técnicas histoquímicas do ácido periódico de Schiff (PAS), Grocott e Fontana-Masson (FM) foram utilizadas e evidenciaram a parede das células das leveduras. Pelo FM observou-se a melanina presente nessas células. As téc- Seven cases of cryptococosis (six cats and one dog) were studied to establish the determining histomorphological and histochemical characteristics in the histopathological diagnosis of this condition. Additional data related to the epidemiology, clinical aspects, sites of the lesions, and gross findings were obtained from the necropsy and biopsy protocols. Histologically, yeasts were observed inside macrophages or free in the parenchyma, associated with scarse to severe lymphohistioplasmacytic inflammatory reaction. In the hematoxylin-eosin (HE) sections, the yeasts were round, with a central cell containing a nucleus, surrounded by a clear halo (usually non-stained capsule). The techniques of periodic Schiff acid (PAS), Groccot (GMS), and Fontana-Masson (FM) were utilized and demonstrated the wall of the yeast cells. The FM stain showed the melanin present in these cells. The Alcian blue and Mayer's mucicarmin stains showed mainly the yeast polysaccharide capsule. The diameter of the cells ranged from 1.67 to 10.00µm and the full diameter of the encapsulated yeasts varied between 4.17 e 34.16µm. Yeast buddings were better observed through the PAS stain and were narrow based, simple or multiple, mainly in the opposite poles of the cells or forming chains. The definitive diagnosis of cryptococosis was established through the histopathological exam, based on the specific morphology of the agent (encapsulated yeast) and on histochemical proprieties, mostly in the cases without fungal culture.

Pneumonia by Cryptococcus neoformans in a goat in the Southern region of Brazil

“…The clinical signs presented by the goat, as well as the gross and histological findings observed in the lungs, are similar to those described by other authors in domestic animals (GUTIÉRREZ & MARÍN, 1999;KOMMERS et al, 2005;LEMOS et al, 2007;LUVIZOTTO et al, 2009;GALIZA et al, 2014). In goats, the lungs appeared to be the major organs affected by cryptococcosis (BARÓ et al, 1998), and the lesions observed in this goat explain the dyspnea, cough and nasal discharge.…”

Fungal pneumonia in dogs and cats with pulmonary clinical signs in southern Brazil

“…Among the fungi that can cause pneumonia, cryptococcosis has the largest number of cases reported in Brazil; however, case reports describe patients mainly with neurological signs (Marcasso et al 2005, Martins et al 2008, Campos et al 2009, Galiza et al 2014, Headley et al 2016, one dog with cutaneous infestation (Martins et al 2014) and another with nasal infection (Pereira et al 2013). Dog A in this study, besides cough with no response to antibiotic treatment, had other clinical signs compatible with a mycotic disease, including fever, lymphadenopathy, and hyphema (Ferreira et al 2007, Greene & Bromel 2012, Hawkins 2014.…”

Características clínico-epidemiológicas, histomorfológicas e histoquímicas da esporotricose felina

“…Esta técnica já tinha sido utilizada na detecção da cápsula de polissacarídeos e da parede celular de Cryptococcus spp. em outro estudo (Galiza et al 2014).…”

“…se mostram fortemente positivos nesta coloração (Kwon-Chung et al 1981, Galiza et al 2014. As diferenças marcantes entre Sporothrix spp.…”

“…e Cryptococcus spp. estão no tamanho das leveduras (maiores), na presença da cápsula polissacarídica e de melanina na parede fúngica deste outro fungo (Kwon-Chung et al 1981, Galiza et al 2014. Outros diagnósticos diferenciais incluem candidíase, histoplasmose, leishmaniose, síndrome leproide felina e o carcinoma de células escamosas (em gatos despigmentados) (Larsson et al 1989, Antunes et al 2009, Gross et al 2009, Guarner & Brandt, 2011.…”