| Autor: |
Rohaim MA; Department of Virology, Faculty of Veterinary Medicine, Cairo University, Giza 12211, Egypt., Naggar RFE; Department of Virology, Faculty of Veterinary Medicine, University of Sadat City, Sadat 32897, Egypt., AbdelSabour MA; Department of Poultry Viral Vaccines, Veterinary Serum and Vaccine Research Institute (VSVRI), Agriculture Research Centre (ARC), Cairo 11381, Egypt., Ahmed BA; Department of Virology, Faculty of Veterinary Medicine, Cairo University, Giza 12211, Egypt., Hamoud MM; Department of Poultry and Rabbit Diseases, Faculty of Veterinary Medicine, Cairo University, Giza 12211, Egypt., Ahmed KA; Department of Pathology, Faculty of Veterinary Medicine, Cairo University, Giza 12211, Egypt., Zahran OK; Department of Animal Hygiene and Veterinary Management, Faculty of Veterinary Medicine, Cairo University, Giza 12211, Egypt., Munir M; Division of Biomedical and Life Science, Lancaster University, Lancaster LA1 4YG, UK. |
| Abstrakt: |
Duck hepatitis virus (DHV) is one of the commercially important diseases of ducklings worldwide. It is an acute and highly infectious disease of ducklings caused by three different serotypes (1-3) of duck hepatitis A virus (DHAV), and serotype 1 is the most common in poultry. To date, little is known about the prevalence and genetic characterisation of DHAV-1 in Egypt. In the current study, isolation and complete genomic analyses of DHAVs circulating in commercial duck farms in different Egyptian governorates were conducted. A total of eighteen samples were collected from six Egyptian governorates of 3-11 days old ducklings (Pekin and Mullard) with a history of nervous signs and high mortality rates. Five out of eighteen (5/18) samples were screened positive for the DHAV-1 based on the VP1 gene. These samples were individually used for virus isolation in embryonated duck embryos (EDE), followed by complete genome sequencing. Phylogenomic analyses showed that DHAV serotype I; genotype I were diversified into four different groups (1-4). Most of the recent circulating Egyptian DHAV strains are clustered within group 4, while isolates characterised within this study were clustered within group 1. Recombination analyses revealed that the emergence of a new recombinant virus-DHAV-1 strain Egypt-10/2019-through recombination. Likewise, the selective pressure analyses showed the existence, inside or near areas of the viral attachment or related functions, of positive scores highlighting the importance of natural selection and viral evolution mechanism at different protein domains. The findings of this study provide updated information on the epidemiological and genetic features of DHAV-1 strains and underscore the importance of DHAV surveillance as well as re-evaluation for currently used vaccines. |
