A study of the chicken astrovirus pathobiology in the emerging white chicks hatchery disease

This thesis aimed to construct a reverse genetics system to introduce the enhanced green fluorescent protein (eGFP) into the CAstV strain, VF11-66, which is associated with white chicks hatchery disease and to utilise the fluorescently tagged CAstV to study the tissue tropism and infection in the adult birds, and identify the route of transmission into the developing egg. However, due to the numerous challenges faced with the cloning of the virus genome and virus rescue, this was not possible.

Instead, the non-recombinant VF11-66 strain was used to infect the adults to study the CAstV infection. From this study, it was identified that CAstV most commonly infected the organs belonging to the enteric system in the adult birds and that the virus was transmitted into the egg via the reproductive organs, in particular the ovules. Furthermore, this study demonstrated the successful reproduction of white chicks hatchery disease in embryos inoculated into the yolk sac with CAstV at a low titre of 1 x 103.5 50% tissue culture infectious dose (TCID50).<br>