Detection and Molecular Characterization of VP1 Gene of Chicken Infectious Anaemia Virus in Suspected Layer Birds

Abstract

Background: Chicken Infectious Anaemia Virus (CIAV) is one of the emerging pathogen of the poultry. The Genus of this virus is Gyrovirus and the family Anelloviridae. Viral DNA contains three open reading frames (ORFs) encoding for three proteins VP1, VP2 and VP3. VP1 protein is major structural protein and is a capsid protein having major role in growth and spread of the virus. Present study was aimed for molecular detection of VP1 gene of the CIA virus in the samples collected from the outbreaks occurred at four different district of Maharashtra. Methods: Total 50 samples comprising of Spleen, bone marrow, thymus and liver, were collected. DNA extracted from those samples was used for PCR amplification targeting, VP1 gene. Selected positive purified PCR products of VP1 were subjected for Nucleotide sequencing and Phylogenetic analysis. Results: Total out of 50 pooled samples, 10 samples were positive for VP1 gene i.e. 20 %. Sequencing of coding region of four CAV positive samples was conducted. Genetic analysis showed three isolates had high similarity with Del-Ros vaccine strainfrom USA ; while one isolate shared close similarity to attenuated cloned isolate 10 of Cux-1 strain. The data also indicated Q139 and Q144 and Q394 amino acids substitutions among the VP1. Phylogenetic analysis of the sequenced viruses based on either the coding nucleotide sequence or VP1 coding sequence, suggested the circulation of III genotypes in Maharashtra.