ETIDIOH - NEW

Abstract Clade 2.3.4.4b H5N1 high pathogenicity avian influenza virus (HPAIV) has caused a panzootic affecting all continents except Australia , expanding its host range to several mammalian species . In March 2024, H5N1 HPAIV was first detected in dairy cattle and goats in the United States . Over 891 dairy farms across 16 states have tested positive until 25th December 2024, with zoonotic infections reported among dairy workers . This raises concerns about the virus undergoing evolutionary changes in cattle that could enhance its zoonotic potential . The Influenza glycoprotein haemagglutinin (HA) facilitates entry into host cells through receptor binding and pH-induced fusion with cellular membranes. Adaptive changes in HA modulate virus-host cell interactions. This study compared the HA genes of cattle and goat H5N1 viruses with the dominant avian-origin clade 2.3.4.4b H5N1 in the United Kingdom , focusing on receptor binding, pH fusion, and thermostability. All the tested H5N1 viru...

Abstract A switch from avian-type α-2,3 to human-type α-2,6 receptors is an essential element for the initiation of a pandemic from an avian influenza virus . Some H9N2 viruses exhibit a preference for binding to human-type α-2,6 receptors . This identifies their potential threat to public health . However, our understanding of the molecular basis for the switch of receptor preference is still limited. In this study, we employed the random forest algorithm to identify the potentially key amino acid sites within hemagglutinin (HA), which are associated with the receptor binding ability of H9N2 avian influenza virus (AIV). Subsequently, these sites were further verified by receptor binding assays. A total of 12 substitutions in the HA protein (N158D, N158S, A160N, A160D, A160T, T163I, T163V, V190T, V190A, D193N, D193G, and N231D) were predicted to prefer binding to α-2,6 receptors . Except for the V190T substitution, the other substitutions were demonstrated to display an affinity for pr...