Genetic characterization of two low pathogenic avian influenza virus H5N1 isolates from Ontario, Canada.

Genomes of two low pathogenic H5N1 avian influenza (LPAI) viruses, A/Turkey/ON/84/1983 and A/Mallard/ON/499/2005 from Ontario, Canada were cloned and genetically characterized. Phylogenetic analysis showed that the Canadian isolates cluster with other North American AIVs and are distinct from the Euro-Asian H5N1 isolates. Individual gene comparisons demonstrated that the Ontario isolates were most similar to the viruses isolated from around the same time period and geographical area. A long deletion of 22 amino acids was identified in the stalk region of NA of A/Turkey/ON/84/1983 isolate, a characteristic mutation related to its adaptation to domestic birds. To our knowledge A/Turkey/ON/84/1983 genomic sequence is the first and only available entire genomic sequence of a H5N1 AIV from domestic birds in Canada and USA.