Isolation and Molecular Characterization of Infectious Bronchitis Virus from Broiler Chickens, Egypt during 2014 -2016

Abstract

In this study, surveillance on infectious bronchitis virus strains in 75 Egyptian broiler chicken flocks was performed using real-time RT-PCR at eight Governorates during 2014-2016. The birds in the selected flocks were suffering from respiratory and renal manifestations. The results of the present study showed that 31 (41%) samples were positive for IBV. All isolates were classified as variants using sequencing analysis of the obtained data and can be divided into 2 groups. Group I (variant) Egyptian IBV included isolates, EG-F728-1-2015-SP1, EG-F728-7- 2015-SP1, EG-F862-3-2015-SP1, EG-F862-4-2015-SP1, EG-F888-2015-SP1, EG-F777-2015- SP1 and EG-F183-1-2016-SP1 which were very close to IBV-IS-1494-06 and had amino acid sequence identities between 87.5% to 96.2%. Group II (variant) Egyptian IBV included isolates, EG-F183-2-2016-SP1 and EG-F183-3-2016-SP1. These two IBV isolates were very close to IBV-IS/885 (variant 2) and they shared amino acid sequence identities from 92.3% to 97.1% with each other. In conclusion, different variants of IBV are present in broiler farms in high prevalence rate even in vaccinated flocks.