Pathotyping of Field Identified Newcastle Disease Isolated from Quail in Egypt

Document Type : Original Articles


1 Department of avian and rabbit medicine, faculty of veterinary medicine, Zagazig University, Egypt.

2 Department of Virology, Faculty of Veterinary Medicine , Mansoura University, Mansoura 35516, Egypt

3 Department of Avian and Rabbit Medicine, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Sharkia, 44511, Egypt.

4 Virology department, Faculty of veterinary medicine, Mansoura University, Dakahlia , Egypt

5 Department of Genetics, Faculty of Veterinary Medicine, Mansoura University, 35516 El-Gomhoria Street, Mansoura, Egypt.


The extreme population growth in developing countries, including Egypt, requires increased and alternative sources of animal proteins. Quails are excellent source. Newcastle disease (ND) causes substantial economic losses and represents perpetual threat to poultry species in Egypt and all over the world. limited data indicates the clinico-pathological features of NDV infection in quails as compared to conventional poultry species. To our knowledge, this work is one of the first studies illustrating the isolation and identification of ND from naturally infected quail farms. Isolation of Newcastle disease virus (NDV) was done using SPF-ECEs for three successive passages via allantoic cavity at 10-days old, while molecular identification was done first by real-time PCR to exclude H5 and H9, then conventional PCR targeting NDV was done. Pathogenicity of one selected isolate was done using ICPI and MDT. Two allantoic fluids out of eleven fluids were positive for avian influenza H5 subtype by real-time PCR, while all allantoic fluids were negative for H9 influenza virus.Allantoic fluids examined by conventional PCR showed five positive samples for NDV targeting the F gene. Pathogenicity indices (intracerebral pathogenicity index (ICPI) and mean death time (MDT) were 1.25 and 77, respectively, indicating that the tested isolate is mesogenic in pathogenicity.


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