Viral Research in Brazilian Owls (Tyto alba and Rhinoptynx clamator) by Transmission Electron Microscopy

Abstract

SUMMARY:The barn-owl (Tyto Alba) and striped-owl (Rhinoptynx clamator) belong respectively to the families Tytonidae and Strigidae. Avian paramyxoviruses have been isolated from a variety of species of wild and domestic birds wordlwide causing diverse clinical symptoms and signs. Paramyxoviruses belong to the family Paramyxoviridae and Avulovirus genus, including nine serotypes (APMV 1 to 9). The lymphoid leukosis is a retrovirus-induced neoplasia. The avian retroviruses belong to the Retroviridae family and to the Alpharetrovirus genus. Coronaviruses can cause respiratory and enteric disease in several species of birds. They belong to the Coronaviridae family and to the groups 3a e 3c. In this study, we describe the presence of viruses in four owls, two barn owls (Tyto alba) and two striped owls (Rhinoptynx clamator), rescued from tree-lined streets of Sao Paulo, Brazil and sent to the Recovery Center of Wild Animals of the Tietê Ecological Park, where the animals died. Fragments of lung, liver and small intestine of these birds were processed for transmission electron microscopy utilizing negative staining (rapid preparation), immunoelectron microscopy and immunocitochemistry 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, an herring-bone helical nucleocapsidlike structure, measuring 15 to 20 nm in diameter, were visualized in the samples of lung, liver and small intestine of all owls. In small intestine samples of the two striped-owl (owls 3 and 4) it was detected pleomorphic coronavirus particles with a diameter of 75-160 nm containing a solar corona-shaped envelope, with projections of approximately 20 nm of diameter. In liver fragments of one striped-owl (owl 4) pleomorphic particles of retrovirus with a diameter of 80-145 nm containing an envelope with short projections and diameter of 9 nm were observed. The presence of aggregates formed by antigen-antibody interaction, characterized the positive result obtained during the immunoelectron microscopy technique for paramyxovirus, retrovirus and coronavirus. In the immunocytochemistry technique, the antigen-antibody interaction was strongly enhanced by the dense colloidal gold particles over these viruses.

Research of Viral Agent in Free-living Pigeon Feces (Columba livia) in the City of São Paulo, SP, Brazil, for Transmission Electron Microscopy

“…These results are in accordance with data in the literature showing particles with similar morphology in pigeons (Gough & Alexander, 1983), owls (Catroxo et al, 2010), ducks (Chang et al, 2001) and Gouldian Finch (Zhang et al, 2006).…”

“…The observation of typical particles of paramyxovirus and coronavirus in 3 (5.2%) out of 57 analyzed samples, corroborates with other authors who have found coronavirus in owls (Catroxo et al, 2010), quail (Circella et al, 2007) and green-cheeked (Gough et al, 2006).…”

Avian Paramyxoviruses: Detection by Transmission Electron Microscopy Techniques

“…Several authors using the same technique, described the presence of particles with morphological characteristics similar in other avian species, as budgerigar (Nerome et al), dove (Alexander et al, 1981;Catroxo et al, 2011), ringedteal (Gough & Alexander), parrot and parakeet (Steffens, 1998, Grund et al), yacinth macaw, rusty collared seedeater, red cowled cardinal, curl crested and peach fronted parakeet (Catroxo et al, 2000), duck (Chang et al, 2001), cockatiel (Clavijo et al), goose (Jinding et al, 2005), gouldian finch (Zhang et al), owl (Catroxo et al, 2010) and penguin (Miller et al; Fornells et al).…”

Simultaneous Infection by Paramyxovirus and Mycoplasma in Red Siskin (Spinus Cucullata), Threatened Species.

“…Pleomorphic rounded or elongated paramyxovirus particles, with a diameter of 100-500 nm, containing a envelope with a single fringe of surface projections approximately 17 nm in lenght, and helical herring-bone-like nucleocapsid, were visualized in the samples of organ fragments and feces of red-siskin (Spinus cucullata). In other avian paramyxovirus research, particles with these basic features were described by the negative staining technique in rusty collared seedeater and red cowled cardinal (Catroxo et al, 2000), Chloebia gouldiae (Zhang et al, 2006), owl (Catroxo et al, 2010), dove (Catroxo et al, 2011), helmeted manakin, common waxbill, double collared seedeater, rufousbellied thrush, great kiskadee, bananaquit, bay-winged cowbird, grey monjita, surucua trogon, green-winged saltator, common canary, wild canary, saffron finch, brazilian tanager, campo troupial, greatbilled, seedfinch, red-crested finch, ultramarine grosbeak, lined seedeater, variable oriole, seven colored tanager, hooded siskin, whitenaped jay, brassy breasted tanager, swallow tanager, buffy-fronted seedeater, gilt-edgerd tanager (Catroxo et al, 2012) and chestnutbellied seed-finch (Catroxo et al, 2022).…”