Article info.

ABSTRACT

Received 26 Aug 2016
Revised 18 Nov 2016

Accepted 29 Jul 2017

Infectious bronchitis virus (IBV) primarily causes highly infectious bronchitis (IB) in commercial chickens. Virus isolation and identification are necessary for diagnosis of the disease. In this study, a total of 5 IBV isolates from commercial poultry farms were isolated by inoculation in 9 day-old embryonated specific pathogenic fee (SPF) eggs. After few passages, the embryos showed typical lesions of IB like stunted and curled cross with feather dystrophy. Then, the 5 IBV isolates were characterized by reverse transcription-polymerase chain reaction (RT-PCR) followed by DNA sequencing of partial S1 gene. The phylogenetic analysis showed that the 5 IBV isolates distinctly clustered into 3 groups. Group 1 consisting of IBV1/15, IBV2/15 and IBV3/15 shared more than 99% similarity with IBV genotype 793/B. Group 2 consisting of isolate IBV4/15 was closely related to genotype QX-like with the similarity of 98%. Interestingly, group 3 consisting of IBV5/15 had genetic distance ranged from 8% to 10% with other reported IBV genotypes such as 793/B, Massachusetts-type, Taiwan-type and QX-like viruses whilst IBV5/15 shared about 99% similarities with a nephropathogenic Malaysian IBV isolate.

Keywords

Commercial chicken, coronavirus, infectious bronchitis virus (IBV), RT-PCR

Cited as: Bich, T.N., Khanh, N.P., Dung, P.H., Loan, N.T.C., 2017. Molecular characterization of infectious bronchitis virus (IBV) isolated from commercial chicken farms. Can Tho University Journal of Science. Vol 6: 56-62.