Journal of Biotechnology & Biomaterials
Open Access

Abstract

In India, outbreak of H5N1 HPAI virus in poultry was confirmed in Maharashtra on 18th February 2006. The virus was characterized as genetic clade 2.2 of H5N1 viruses, since then outbreaks have been reported in poultry almost every year till 2010. Recently, a new clade 2.3.2.1 of H5N1 virus has been isolated from chickens and ducks from Tripura in 2011. Antigenic analysis revealed significant antigenic differences between the two viral clades hence the present study was taken up with a goal to mimic the in vivo immune selection process of clade 2.3.2.1 virus in the presence of clade 2.2 viral antibodies. The H5N1 virus isolate A/chicken/India/03Cl488/2011 (clade 2.3.2.1) was given serial passages (50 passages) in embryonated SPF chicken eggs in the presence of chicken anti-serum against a clade 2.2 virus (A/chicken/West Bengal/239020/2008). Antigenic and Genetic analysis was carried out and different variants were generated, as expected, nucleotide substitutions were observed in the highly variable HA gene of the H5N1 virus.The mutations in the nucleotide sequence led to amino acid substitutions. For example, there were three amino acid substitutions in the antigenically significant HA1 (P74T, R189G and T315I).Analysis of HA amino acids sequence with NetNGlyc 1.0 server revealed of one additional glycosylation site at position 72 due to amino acid alterations P74T. In addition avian-receptor specificity (α2,3-linkage sialic acids) polybasic amino acid motif in the HA cleavage region, and susceptible to anti-influenza drugs were analysed. The present study highlights the importance to understand the antigenic drift that could evolve in case of vaccination, response that aim at maintaining a high level of avian emergency preparedness and capacity to rapidily repond to disease outbreaks.

Biography

M. Qureshi has completed masters in Veterinary Virology from Indian Veterinary Research Institute. She carried out her research in HSADL, Bhopal (O.I.E reference laboratory), presently doing PHD in All India Institute of Medical Sciences, New Delhi.