|1681-1||Identification of paramyxovirus particles in small intestine of thick billed (Oryzoborus angolensis) utilizing transmission electron microscopy techniques.|
|Autores:||Marcia Helena Braga Catroxo Catroxo, M.h.b. (IB - Instituto Biológico) ; Ana Maria Cristina Rebelo Pinto da Fonseca Martins Martins, A.m.c.r.p.f. (IB - Instituto Biológico) ; Liliane Milanelo Milanelo, L. (IB - Instituto Biológico) ; Fabíola de Souza Souza, F. (IB - Instituto Biológico) ; Beatriz Di Boaretto Nastari Nastari, B.d.b. (IB - Instituto Biológico) ; Rodrigo Barbosa de Souza Souza, R.b. (IB - Instituto Biológico) |
Avian paramyxoviruses (APMV) are non segmented single stranded RNA. They belong to the Mononegavirales order, Paramyxoviridae family and Avulovirus genus. This genus includes nine serotypes that have been documented in a variety of wild, domestic and pet birds worldwide. APMV 2 and 3 types occur often among free living, showing variable clinical symptoms and signs. APMV 2 causes a mild upper respiratory tract disease. The illness caused by PMV 3 is characterized by conjunctivitis, yellowish diarrhea, dyspnea, dysphagia, pancreatitis and central nervous system symptoms. Birds of all ages are susceptible but mortality rates are higher in neonates. Small birds are frequently cachectic, suggesting a chronic disease or the inability to eat and drink. The transmission occurs through oral-fecal routs and by aerosols. Oryzoborus angolensis is a bird of the Emberezinae family, found throughout the Brazilian territory, mainly in the littoral. It is one of the singing birds most wanted by illegal trade and is listed as endangered to extinction by the Brazilian Institute of Environment and Renewable Natural Resources (IBAMA). During illegal commercialization of Brazilian birds occurred in 2009, 218 thick billed (Oryzoborus angolensis) were apprehended and being forwarded to the CRAS (Wild Animals Recovery Center), Tietê Ecological Park. 112 birds arrived dead and the rest died during the year. Of these, 35 were sent to the Electron Microscopy Laboratory of the Biological Institute of São Paulo to investigate viral agents. During the necropsy was observed the presence of dilated small intestines with yellow and watery stools. Fragments of small intestines were processed for transmission electron microscopy utilizing negative staining (rapid preparation), resin embedding and immunocytochemistry techniques. Under the transmission electron microscopy paramyxovirus particles, pleomorphic, roughly spherical or filamentous, measuring 100 to 500 nm of diameter, containing an envelope covered by spikes, with characteristic helical herring-bone like nucleocapsid were visualized in the samples of small intestine of all birds. Antigen-antibody reaction was enhanced by the colloidal gold particles. Ultrathin sections of the small intestine revealed the presence of intracytoplasmic inclusions formed by helical nucleocapsids and complete particles measuring 100 to 250 nm. Incomplete particles budding of plasma membrane were also observed.
Palavras-chave: Paramyxovirus, Oryzoborus angolensis, Transmission electron microscopy