Scientists ID bird flu virus mutations

TOKYO, Nov. 16 (UPI) -- Japanese scientists say they have discovered two mutations in the H5N1 avian influenza virus that enable it to recognize human receptor proteins.

Yoshihiro Kawaoka and colleagues at the University of Tokyo's Institute of Medical Science say the amino acid changes might prove useful molecular markers for assessing the pandemic potential of H5N1 samples.

To replicate efficiently in humans it's thought bird influenza viruses must acquire the ability to recognize human host cell receptors. The Japanese researchers, therefore, looked for mutations in a protein called haemagglutinin that appears on the surface of the H5N1 virus and binds with host receptor proteins.

They found two separate mutations in the haemagglutinin of H5N1 viruses known to recognize avian receptors that enabled these viruses to recognize human receptors.

The research is detailed in the online edition of the journal Nature.