ABSTRACT
In this study, two isolates of infectious bronchitis virus (IBV) from field outbreaks in 2008 (India/LKW/56/IVRI/08) and 2010 (India/NMK/72/IVRI/10) from broiler chickens in India were isolated and characterized. Reverse transcription polymerase chain reaction-restriction fragment length polymorphism of the entire S1 gene revealed that these isolates belong to two different genotypes, India/LKW/56/IVRI/08 as Mass strain whereas India/NMK/72/IVRI/10 as of different genotype. Nucleotide sequencing analysis showed that India/LKW/56/IVRI/08 shared 99 % homology with THA280252 (Thailand) and India/NMK/72/IVRI/10 shared greater than 99 % homology with 4/91 pathogenic strain (UK), JP/Wakayama/2/2004 (Japan) and TA03 (China), while the two Indian IBV isolates shared 73 % identity between them. Phylogenetic data allowed classification of two Indian isolates, India/LKW/56/IVRI/08 as having unique lineage within Mass genotype and India/NMK/72/IVRI/10 as of 4/91 genotype. Our study confirmed the presence of 4/91 (793/B) IBV nephropathogenic strain for the first time in India by virus isolation and sequencing.
