Biological and genetic characterization of a low-pathogenicity avian influenza H6N2 virus originating from a healthy Eurasian coot

Influenza A virus, A/Eurasian coot/Western Australia/2727/79 (H6N2), from an apparently healthy coot was characterized. This virus was able to grow on MDCK cells and produce a cytopathic effect in the absence of exogenous trypsin and was further characterized as a low-pathogenicity avian influenza virus, with an intravenous pathogenicity index of 0.15 and a 321 PQAETRG 328 motif at the cleavage site of the haemagglutinin gene. It infected domestic chickens, resulting in seroconversion and intermittent virus excretion via cloaca and oropharynx under experimental conditions. Phylogenetic analysis showed that the viral genes were closely related to other waterfowl isolates from the same geographic area and time period.