Molecular detection of Viral diarrhea in Rabbits

Keywords Enteric diseases represent a major problem in rabbit production. These causes high losses as result of mortalities and decreased conversion indexes. This study focused on viral agents (e.g., Astrovirus, Coronavirus (CoV), Rotavirus (RV) and Rabbit Hemorrhagic Disease Virus (RHDV)) as one of the causes of diarrhea in rabbits. 140 samples were collected from commercial farms located at Menofia and Qalyubia governorates, Egypt, during the period from October 2020 to May 2021. Our study focused on live and dead rabbits who showed diarrhea at the age of 7 days and up to 150 days of age. The most apparent symptoms were diarrhea, and the postmortem examination showed the presence of localized area of necrosis in different organs and splenomegaly. All samples in the current research came up negative for Astrovirus, Corona virus and Rota virus using Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) and though some samples were positive for RHDV in the liver and intestinal samples of dead rabbits with enterocolitis. Sequencing and phylogenetic analysis of the VP60 gene of the RHDV strain showed that it is related to RHDV2. Genetic analysis of our strain (RHV-Egypt-BenhaF954-2022) was clustered with G1.2/RHDV2/b strains with homology 97.1%. Homology with Egyptian classical strains were 96.6% with G1.1C/RHDV and 87.6% with G1.1a/RHDVa. The genetic diversity between the study obtained strain and other reference RHDV strain is indicative to probability of antigenic diversity.