Scienceline Publications Journal of World's Poultry Research 2322-455X 11 3 2021 September Isolation and Molecular Characterization of Rabbit Haemorrhagic Disease Virus Strains Circulating in Rabbit Population Using Sequencing and Phylogenetic Analysis n Upper Egypt 302 311 https://jwpr.science-line.com/attachments/article/59/JWPR%2011(3)%20302-311,%202021.pdf EN Samah El Sayed Ali Abodalal Newcastle Disease Department, Veterinary Serum and Vaccine Research Institute, Agriculture research center, Abbasia, Cairo, Egypt, P.O.B.131 Mohammed Shaker Abdel Hafez Birds and Rabbits Diseases Department, Faculty of Veterinary Medicine, New Valley University, Egypt Eman Abd El-Munem Shosha Microbiology and Immunology Department, Faculty of Veterinary Medicine, NewValley University, Egypt Fatma Fadal Warda Horse sickness Research Department, Veterinary Serum and Vaccine Research Institute, Agriculture research center, Abbassia, Cairo, Egypt, P.O.B.131 Naglaa Mohammed Hagag National Laboratory for Veterinary Quality Control on poultry production, AHRI, Agriculture Research Center P.O.Box264, Dokki, Giza Rabbit hemorrhagic disease (RHD) is a contagious viral disease that threatens rabbit farms locally and globally. The disease causative agent is the 63-Rabbit_Haemorrhagic_Disease_Virus_Strains_Circulating_in_Rabbit_Population_RHD virus (RHDV) of the family Caliciviridae. The present study aimed to identify and characterize RHDV strains currently circulating in Upper Egypt provinces. A total of 20 suspected RHDV samples were collected from non-vaccinated rabbit flocks from January to December 2019 in Upper Egypt governorates (New Valley and Assuit), Egypt. The RHDV was confirmed through the hemagglutination test (HA) and reverse transcription-polymerase chain reaction (RT-PCR). Further characterization of selected 4 isolates was performed by nucleotide sequencing of a partial VP60 gene. All of 11 RHDV RT-PCR-positive samples were positive for HA activity against human RBCs type "O". Based on the nucleotide sequencing, the selected 4 isolates were clustered as RHDV-1 variant strains (G3-G5). The nucleotide sequence identities of the 4 isolates were 94.2-100 %, compared to available RHDV strains from GenBank. In conclusion, the presence of RHDV-1 variant strains was detected and confirmed that threatens the rabbit’s populations in New Valley and Assuit governorates. Upper Egypt Nucleotide sequencing Rabbit hemorrhagic disease virus Reverse transcription-polymerase chain reaction VP60