Occurrence, diversity and molecular pathogenicity of avian coronavirus in quail

Abstract

Diseases caused by Avian Coronavirus are of high importance to poultry industry in terms of economic losses and the possibility of transmission between species of birds. Among the known coronaviruses in poultry production, infectious bronchitis virus (IBV) and turkey coronavirus (TCoV) are the most important. While the first presents in different serotypes and pathotypes, causing diseases of the respiratory, reproductive, enteric, renal tracts, the second is more frequently associated with enteritis. In quail, which constitute an emerging area of the Brazilian poultry industry, there are few reports of coronavirus occurrence, demonstrating the lack of knowledge about this virus in this species. Therefore, this project aims to study the occurrence, the molecular diversity and pathogenicity of coronaviruses in quails. For this, organs of quail and laying hens kept in the same farms and quail isolated from other creation will be sample in a total of 10 farms. These organs are going to be submitted to a nested RT-PCR targeted to the 3'UTR of the avian coronavirus, and positive samples of quail are going to be subjected to isolation attempts in SPF eggs. Next, the isolates are going to held to a nested RT-PCR leading to partial amplification of the S protein coding region of the avian coronavirus and partial amplification of the region encoding the N protein of IBV, the amplicons obtained are going to be subject to DNA sequencing and phylogeny analysis to determine the avian coronavirus genotypes. Other two RT-PCR are going to used to detect Avian metapneumovirus (AMPV) and Newcastle disease virus (NDV). Finally quail isolates obtained in the experiment samples and other strains previously isolated from chickens, are going to be inoculated into SPF chickens or quail to evaluate virus transmission between species and the role of quail as a reservoir of infectious bronchitis virus of chickens. It is expected to contribute to understanding the epidemiology of avian coronaviroses and their importance in quails, for the generation of bases to the design of prophylactic measures and to further clarify the evolution of the genus Coronavirus.