Transmissible Viral Proventriculitis Caused by Chicken Proventricular Necrosis Virus Displaying Serological Cross-Reactivity with IBDV

SIMPLE SUMMARY: In our study we were trying to evaluate the etiological agent behind transmissible viral proventriculitis in broiler chickens—the disease that causes severe losses to the poultry industry. The results of our study confirm the hypothesis that the disease is caused by chicken proventricular necrosis virus (CPNV), a member of the Birnaviridae family. Additionally, we have discovered that after CPNV infection, birds produce antibodies that can be detected with the use of a commercial test, which is specific against other, well-characterized Birnaviridae family member. The results of our study shed a new light on the subjects concerning the diagnosis and prevention of transmissible viral porventriculitis in chickens. ABSTRACT: Transmissible viral proventriculitis (TVP) of chickens is manifested in decreased body weight gains, poor feed conversion and weight diversity. Although TVP etiology has not been defined, a Birnaviridae family member, named chicken proventricular necrosis virus (CPNV) is considered as a potential factor of a disease. This study was undertaken in order to reproduce TVP and to evaluate its etiology. Broiler chickens of the TVP-infected group were inoculated with TVP positive proventriculi homogenate on the 24th day of life. Samples were collected, on infection day and 14 days post-infection (dpi). The 14 dpi anatomo- and histopathological evaluation, revealed that we have succeeded to reproduce TVP. TVP-infected birds gained 30.38% less body weight. In the TVP-infected group a seroconversion against picornaviruses, fowl adenoviruses (FAdV) and infectious bursal disease viruses (IBDV) was recorded with an ELISA test. Using RT-PCR and PCR, CPNV was detected in proventriculi and FAdV in spleens and livers of infected birds, 14 dpi. Our study supports that CPNV is involved in the development of TVP. We did not record the presence of IBDV in TVP or control birds, despite our recording of a seroconversion against IBDV in TVP infected birds. CPNV and IBDV belong to the same family, which allows us to assume serological cross-reactivity between them. The role of FAdV needs further evaluation.