The occurrence of Aspergillosis in flock of turkey poults.

Aspergillosis is frequent fungal disease of different avian and mammal species, caused by infection by the fungi of genus Aspergillus. The disease is characterized by inflammatory changes in the respiratory system and sometimes has generalized onset when more organ systems are affected. In this paper, we examined a flock of turkey poults, 21 days old, at one farm in Serbia. Clinical signs of central nervous system in the form of ataxia, torticollis, paresis and paralysis of legs and wings were observed. The mortality rate in the flock was 7,2 %. In ten out of twelve necropsied turkey poults multiple yellowish-white granulomas, one to three millimeters in diameter on lungs were found. In nine out of twelve necropsied turkey poults solitary yellowish-white granuloma, three to five millimeters in diameter on sagital section of the cerebrum or cerebellum were found. Mycological finding revealed fungi Aspergillus fumigatus. For the evaluation of histopathological changes in lung and brain and demonstration of fungal hyphae, three stain methods were used: haematoxylin-eosin (HE), Grocott methenamine silver and periodic acid Schiff (PAS) method. Microscopic examination of lung and brain has revealed the presence of granulomatous foci and caseous necrosis with surrounding region of proliferation including giant cells, macrophages, heterophils and lymphocytes and outer capsule of connective tissue. The fungal hyphae were hardly or not visible in HE stained sections, while septed and arborized hyphae were easily demonstrated by Grocott and PAS stain predominantly in central parts of granuloma. For diagnostic of mycotic infection is necessary to use different histochemical methods for evaluation of histopathological changes and detection of etiological agent, including isolation to obtain etiological diagnosis.