الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Infectious bronchitis is one of the most common pathogens
in the poultry industry worldwide. It adversely affects poultry
producers and their industry. It is considered one of the most
important diseases affecting the respiratory system and some of the
strains have the ability to infect the kidneys in small chickens,
leading to inflammation of the kidney, which can cause a high level
of mortality among the herds of chickens. This disease is
characterized by a lot of varieties in the genetic formation,
especially the protein S1, resulting in the emergence of new strains
of the disease, which leads to the reduction of immunity caused by
vaccination.
In this study, the prevalence of IBV was assessed in
Egyptian poultry farms, where 200 farms from Sharkia Governorate
and 200 farms from other governorates (Fayoum, Ismailia, Beheira
and Dakahlia) were examined over the past three years (2014, 2015,
2016) using real time PCR (rRT-PCR) series that found 113 farms
were positive with percentage 28%, also the results showed that 78
of the 345 vaccinated herds were found positive (23%), while the
non-vaccinated herds (35) of 55 samples showed positive results for
the disease.
The results of isolation of the virus in SPF eggs showed
hemorrhage, dwarfing, and twisting in the embryo injected with the
virus. Five passages were performed in the present study before the
virus isolation attempt was considered negative. In this study,