Detection and genetic characterization of chicken astrovirus and Avian Nephritis virus from hatchery to farm

Abstract

Astroviruses are an emerging hazard in hatchery management, and they are responsible for great economic losses in poultry farms worldwide. Chicken astrovirus (CAstV) and Avian Nephritis virus (ANV) are involved in hatching decrease mainly due to embryo deaths, pale and runted chicks too weak to hatch. Hatchery diseases occur through direct egg infection or through vertical transmission. However, the specific role of astroviruses in these diseases is still largely unknown. To elucidate this question, a high-quality Piedmont hatchery (Italy) was selected based on farm clinical signs and the Astrovirus serological positivity in the breeder farm. The viral dynamics was followed from the hatchery to the farm. The presence of both CAstV and ANV was monitored by evaluating the viral load, in environmental and animal samples. Interestingly, both viruses were detected in chick yolk sacs at 18th day incubation, in the gut contents of 1-day chicks, whereas the hatchery environmental samples, the external eggs’ surfaces and the embryos intestinal contents were negative. The CAstV copy number was higher in animal tissues from hatchery, while a greater ANV load was detected in animal tissue from farm. Moreover, our data suggested a vertical transmission ascribed to both viruses. A frequent co-infection was also observed in samples from both hatchery and farm. Lastly, the first Italian full-length genome and molecular characterization of ANV was obtained.

Keywords:

• Avian Nephritis virus
• Chicken astrovirus
• hatchery
• complete genome
• vertical transmission
• co-infection
• tissue distribution

Disclaimer

As a service to authors and researchers we are providing this version of an accepted manuscript (AM). Copyediting, typesetting, and review of the resulting proofs will be undertaken on this manuscript before final publication of the Version of Record (VoR). During production and pre-press, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal relate to these versions also.