Molecular diagnosis of avian viruses in grassland passerines and captive yellow cardinals Gubernatrix cristata in Brazil

Abstract

ABSTRACT: Avian influenza viruses (AIVs), Newcastle disease virus (NDV), West Nile virus (WNV), adenovirus (AV) and herpesvirus (HV) play an important role in the health of human and animal populations. However, knowledge of the prevalence of these viruses in wild birds is restricted to some groups (e.g. shorebirds) or regions worldwide. Information on grassland birds of South America, which is essential for their conservation, is scarce. The objectives of the present study were to evaluate occurrences of AIV, NDV, WNV, AV and HV for the first time in a bird community of a unique protected area in southern Brazil, which is home for the critically endangered yellow cardinal (Gubernatrix cristata), and captive yellow cardinals from fauna maintainers of the Brazilian Captive Program of the Yellow Cardinal. Passerine species of wild life were caught, identified and samples (swabs) were collected from the oropharynx and cloaca of 64 passerines of 26 species (including 3 yellow cardinals) and 30 yellow cardinals of captive, for molecular diagnosis. The samples were subjected to RNA and DNA extraction and the real-time polymerase chain reaction (RT-PCR) for AIV, NDV and WNV and nested PCR for AV and HV. One yellow cardinal of captive presented a positive result for AV, this result is important for planning, managing natural attributes and making decisions in relation to integrated conservation of threatened species. This is the first report of AV in yellow cardinal and epidemiological investigation of viruses in wild passerines of the Pampa biome, in Rio Grande do Sul, Brazil.