Presence of IS/1494/06 genotype-related infectious bronchitis virus in breeder and broiler flocks in Turkey

Abstract

In this study, infectious bronchitis (IB)-suspect problems were observed in 2 broiler and 8 breeder chicken flocks vaccinated with H120 strain, and a total of 220 tracheal swabs were taken from 60 broiler chickens of 2 flocks (30 swabs/flock), and 160 breeder chickens of 8 flocks (20 swabs/flock) to detect infectious bronchitis virus (IBV) by a reverse transcriptase polymerase chain reaction (RT-PCR) and to isolate IBV from chickens showing respiratory sings and nephritis lesions. Detection of 8 Turkish IBVs from the tracheal swab samples directly by RT-PCR was confirmed by both IBV isolation from allantoic fluids of embryonated eggs and by the same RT-PCRs from these samples. Basic Local Alignment Search Tool (BLAST) results revealed that all 8 sequences from our Turkish IBV isolates were related to that of EU780077 (IS/1494/06 IBV strain) with a 99% identity. Phylogenetic and alignment analyses of the sequences of two representative isolates as TR_IS1494_06_B12011 from one broiler flock and TR_1494_06_7201 from one breeder flock also confirmed this close relation to IS/1494/06 IBV genotype. As a result, Turkish IBVs have been isolated for the first time from chickens, which were not protected from IB despite IBV H120 strain vaccination, and genotyped as IS/1494/06 in Turkey suggesting the transfer of this IBV from the countries of Middle East.