The identification of amino acid motifs responsible for increased virulence and/or transmission of influenza viruses is of enormous importance to predict pathogenicity of upcoming influenza strains. We phenotypically and genotypically compared 2 variants of influenza virus A/PR/8/34 with different passage histories. The analysis revealed differences in virulence due to an altered type I interfe...

background and aims: avian influenza (ai) h9n2 subtype was first reported to infect turkeys in the united states in 1966 and has been panzootic in europe and asia. the impact of avian influenza caused by h9n2 viruses in iran is now significantly more severe than in previous years. methods: sequence analysis and phylogenetic study of the complete coding region polymerase a (pa) gene of h9n2 subt...

BACKGROUND Influenza vaccine composition is reevaluated each year due to the frequency and accumulation of genetic changes that influenza viruses undergo. The beginning of the 2016-2017 influenza surveillance period in Israel has been marked by the dominance of influenza A(H3N2). OBJECTIVES To evaluate the type, subtype, genetic evolution and amino acid substitutions of influenza A(H3N2) viru...

Type B influenza viruses can cause substantial morbidity and mortality in the population, and vaccination remains by far the best means of protection against infections with these viruses. Here, we report the construction of mutant influenza B viruses for potential use as improved live-virus vaccine candidates. Employing reverse genetics, we altered the NS1 gene, which encodes a type I interfer...

Influenza has been recognized as a respiratory disease in swine since its first appearance concurrent with the 1918 „„Spanish flu‟‟ human pandemic. All influenza viruses of significance in swine are type A, subtype H1N1, H1N2, or H3N2 viruses. Swine Influenza is a respiratory disease of pig caused by Type A influenza viruses. Influenza A causes moderate to severe illness and affects all age gro...

A novel ganglioside bearing Neua2-3Gal and Neua2-6Gal structures as distal sequences was designed as a ligand for influenza A viruses. The efficient synthesis of the designed ganglioside was accomplished by employing the cassette coupling approach as a key reaction, which was executed between the non-reducing end of the oligosaccharide and the cyclic glucosylceramide moiety. Examination of its ...

BACKGROUND Wild waterfowl are considered as the natural reservoir for avian influenza (AI) viruses. Bangladesh has been experiencing highly pathogenic avian influenza (HPAI) outbreaks since 2007, mostly in chickens and occasionally in ducks. Ducks play an important role in the persistence and genetic recombination of AI viruses. This paper presents the results of serological and virological mon...

Abstract : Avian influenza virus (AIV) infection is a major cause of influenza mortality in birds and can cause human mortality and morbidity. Although the risk of infection with avian influenza virus (AIV) is generally low for most people, the pathogenic virus can cross the species barrier and acquires the ability to infect and be transmitted among the human population; therefore the ra...

Avian influenza viruses are considered to be key contributors to the emergence of human influenza pandemics. A major determinant of infection is the presence of virus receptors on susceptible cells to which the viral haemagglutinin is able to bind. Avian viruses preferentially bind to sialic acid alpha2,3-galactose (SAalpha2,3-Gal) linked receptors, whereas human strains bind to sialic acid alp...

A new pandemic influenza in the human world may originate from avian reservoirs. Influenza is one of the most widely spread zoonotic infectious diseases. All avian influenza viruses are type A, and they have often caused pandemics throughout human history. The highly pathogenic H5N1 influenza A viruses have now been spreading to many countries in Asia, Europe and Africa. They have infected an i...