الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 171 |  |  |
| | | from | 171 | | |
Abstract
Avian influenza virus (AIV) is a highly contagious viral disease of poultry, listed as list A by WHO as a
notifiable viral disease due to its severe outbreaks and high morbidity in the susceptible host that exhausts the
country economy. This study aims to molecular and epidemiological identification of the discovered AIV in both
domestic and wild birds. Also, mapping receptor binding domain (RBD) and major antigenic sites in
hemagglutinin (HA) for both H5 and H9 AIV to determine any mutations occurred. One of study concerns is the
characterization, predicting and visualizing antibody-binding epitopes in a protein sequence or structure of
H5AIV, compared with some vaccinal seeds used in Egyptian field to assess the cross-neutralization capacity
of available vaccines. One hundred and eight domestic flocks of different breeds, ages, and species (112)
chicken, (6) Ducks in the period 2022-2023 were collected from five Egyptian provinces and examined for
detection of AIV subtypes. Five flocks were positive for H5N8 AIV; 3 flocks were mixed infection of H5N1AIV
and NDV, while 30 flocks were positive for H9N2AIV and one infective flock with both H9N2 and H5N1
positive. Likewise, forty flocks of migratory and resident wild bird were given two flocks positive for H9N2
AIV by virus isolation followed by HA and HI test. Moreover, the partial gene sequencing of HA of selected
seven positive samples all aligned with circulating strains and vaccinal seeds which present in Genbank, then
determine if there is a difference among these strains. The predicted linear and discontinuous epitopes of H5
AIV using Ellipro web tool were more like vaccinal seed (A/green-winged teal/Egypt/877/2016 (H5N8). The
study result shows an ineffectiveness indication about some of the commercial poultry H5 and H9 vaccines used
in Egyptian field as the seed viruses in these vaccines are genetically different from the H5N8 and H9N2 viruses
currently circulating in Egypt.