Analysis of Neuraminidase Inhibitors Resistance to H5N1 & H1N1 of Influenza Virus A from 2005-2007, 2010 & 2013

Abstract

There are three types of influenza viruses which are A, B and C. Among these three viruses only influenza A virus can infect wide variety of animals like horse, pigs, birds etc. even human. There are different subtypes of Influenza A virus which are HA (Hemagglutinin) and NA (Neuraminidase). Hemagglutinin and Neuraminidase are proteins which are located on the surface of the virus. 18 different HA subtypes (H1 to H18) and 11 different NA subtypes (N1 to N11) are found. In most of the cases infected birds exhibits no symptoms. These infected birds may act as silent reservoir of the virus which may affect the other birds by transmitting the virus. Low pathogenic viruses can be mutated to Highly Pathogenic Avian Influenza (HPAI) strains during replication. Variants from unique HPAI viruses could cause infection and has the ability to replicate in humans. Phylogenetic analysis helps to find out the evolution of influenza viruses. Phylogenetic tree helps to find out the diverse strains from a couple of strains. Phylogenetic tree shows the evolutionary interrelations of a group of organisms derived from a common ancestral form. It is also used to conceptualize, visualize, and analyze the relationships among biological lineages. In most of the cases phylogenetic analysis is carried out with protein sequence because proteins are the fundamental building blocks of life. While DNA sequences consist of only four bases A, G, C, and T, the functional properties of proteins are determined by a sequence of 20 possible amino acids, which leads to a much higher resolution at large evolutionary distances. This study brings the analysis of phylogenetic tree and amino acid sequences of Neuraminidase (NA) from the influenza A virus that can infect a wide variety of birds and mammals. We have analyzed strains of three different years (2005, 2006, 2007, 2010 & 2013) of H5N1 & H1N1 from different country to see the drugs resistance pattern with respect to reported mutant position of amino acid. We did not find the exact location where reported mutations are occurred. But we found similar amino acid near the reported mutated position. We have analyzed around (before and after the mutation point) twenty positions with respect to the reported mutation point. We found same mutations around the mutated position that may cause drugs resistance.