Journal of Pure and Applied MicrobiologyVol. 9 No. 3

Membrane and Envelope Gene Sequence Analysis and Characterization of an Indian Avian Infectious Bronchitis Virus Vaccine Strain

Kamble Nitin Machindra, S. Aravind, Sanjeev Kumar Shukla, Khulape Sagar Ashok, Sohini Dey and C. Madhan Mohan*

R-DNA Laboratory, Division of Veterinary Biotechnology, IVRI, Izatnagar, Bareilly - 243122, India.

Received on 11 April 2015 and accepted on 15 June 2015

 

ABSTRACT

Indian avian infectious bronchitis virus (IBV) vaccine strains isolated from live attenuated commercial IBV vaccine was characterised based on M and E gene sequence. RNA was extracted and RT-PCR technique was performed to amplify the M and E gene sequence encoding membrane and envelope protein of IBV. Recombinant plasmid named pTZ57R/T-M and pTZ57R/T-E was constructed via inserting the M and E gene into the TA cloning vector, pTZ57R/T respectively. The sequenced M and E gene and its deduced amino acid sequences were compared with the published sequences of reference strains. The M and E gene is of 678 bp and 330 bp in length encoding 225 amino acids and 109 amino acids with a predicted molecular weight of 25.5 kDa and 12.46 kDa respectively. The sequences of the M and E gene share 96.8-99.7% and 82.1-100% homologous identities at nucleotide level with published reference vaccine strain and field isolate strains from different regions and countries respectively. E gene showed significant variation in sequence identities. Phylogenetic tree based on these M and E sequences was generated, and the tree topology suggests that Indian IBV vaccine strain share common ancestor with routinely used reference vaccine strain sequences.

Keywords : Infectious bronchitis virus (IBV), M gene, E gene, Phylogeny, Vaccine.