RESUMO
The detection of avian coronaviruses (AvCoV) in wild birds and the emergence of new AvCoV have increased in the past few years. In the present study, the pathogenicity of three AvCoV isolates was investigated in day-old chicks. One AvCoV isolated from a pigeon, which clustered with the Massachusetts vaccine serotype, and two AvCoV isolated from chickens, which grouped with a Brazilian genotype lineage, were used. Clinical signs, gross lesions, histopathological changes, ciliary activity, viral RNA detection, and serology were evaluated during 42 days post infection. All AvCoV isolates induced clinical signs, gross lesions in the trachea, moderate histopathological changes in the respiratory tract, and mild changes in other tissues. AvCoV isolated from the pigeon sample caused complete tracheal ciliostasis over a longer time span. Specific viral RNA was detected in all tissues, but the highest RNA loads were detected in the digestive tract (cloacal swabs and ileum). The highest antibody levels were also detected in the group infected with an isolate from the pigeon. These results confirm the pathogenicity of Brazilian variants, which can cause disease and induce gross lesions and histopathological changes in chickens. Our results suggest that non-Galliformes birds can also play a role in the ecology of AvCoV.
Assuntos
Anticorpos Antivirais/sangue , Galinhas/virologia , Columbidae/virologia , Infecções por Coronavirus/veterinária , Gammacoronavirus/patogenicidade , Doenças das Aves Domésticas/virologia , Doenças da Traqueia/veterinária , Animais , Infecções por Coronavirus/virologia , Gammacoronavirus/genética , Gammacoronavirus/imunologia , Gammacoronavirus/isolamento & purificação , Genótipo , Vírus da Bronquite Infecciosa/genética , Vírus da Bronquite Infecciosa/imunologia , Vírus da Bronquite Infecciosa/isolamento & purificação , Vírus da Bronquite Infecciosa/patogenicidade , Traqueia/virologia , Doenças da Traqueia/virologiaRESUMO
This study showed that the most of the coronaviruses (CoVs) detected in Brazilian wild birds clustered with the mouse hepatitis virus A59 strain, belonging to the BetaCoV group. Furthermore, CoV detected in two different bird species, Amazona vinacea and Brotogeris tirica, clustered with a CoV isolated from Sparrow (SpaCoV HKU17) belonging to a monophyletic group related with the CoVs isolated from swines (PorCoV HKU15), both belonging to the DeltaCoV genus, previously unreported in South America. Considering the risk of inter-species host switching and further adaptation to new hosts, detection in bird species of CoVs closely related to mammal CoVs should warn for the potential emergence of new threatening viruses.
Assuntos
Evolução Biológica , Doenças das Aves/virologia , Infecções por Coronavirus/veterinária , Coronavirus/genética , Animais , Brasil , Infecções por Coronavirus/virologia , Genoma Viral , Especificidade de Hospedeiro , Mamíferos/virologia , FilogeniaRESUMO
Avian bornavirus (ABV) has been identified as the cause of proventricular dilatation disease in birds, but the virus is also found in healthy birds. Most studies of ABV have focused on captive birds. We investigated 86 free-ranging psittacine birds in Brazil and found evidence for natural, long-term ABV infection.
Assuntos
Doenças das Aves/virologia , Bornaviridae , Infecções por Mononegavirales/veterinária , Animais , Doenças das Aves/epidemiologia , Doenças das Aves/patologia , Aves , Bornaviridae/classificação , Bornaviridae/genética , Brasil/epidemiologia , Genótipo , Vigilância em Saúde Pública , RNA ViralRESUMO
Cytauxzoon spp. DNA was detected for the first time in blood samples from asymptomatic Brazilian wild captive felids. In 2006, 72 EDTA blood samples from seven wild felids species: Puma concolor (puma), Leopardus pardalis (ocelot), Puma yagouaroundi (jaguarundi), Leopardus wiedii (margay), Leopardus tigrinus (little spotted cat), Oncifelis colocolo (pampas cat) and Panthera onca (jaguar) were analyzed using polymerase chain reaction to amplify the 18S rRNA gene segment in order to verify the presence of Cytauxzoon spp. DNA. Nine samples were positive: six ocelots, two pumas, and one jaguar. In Brazil, wild felids may be natural reservoirs for Cytauxzoon spp.