Simultaneous genotyping of all hemagglutinin and neuraminidase subtypes of avian influenza viruses using padlock probes

Joint Research and Development Division, Department of Virology, The National Veterinary Institute and the Swedish University of Agricultural Sciences. Ulls väg 2B, SE-751 89 Uppsala, Sweden; Department of Genetics and Pathology, Rudbeck Laboratory, Uppsala University, SE-751 85 Uppsala, Sweden; Stanford Genome Technology Center, Stanford University, CA 94304, USA

^* To whom correspondence should be addressed. Email: peter.gyarmati{at}sva.se.

	Abstract

A subtyping assay for both the hemagglutinin (HA) and neuraminidase (NA) surface antigens of the Avian Influenza virus (AIV) has been developed. The method uses padlock probe chemistry combined with a microarray output for the detection. The outstanding feature of this assay is its capability to designate both the HA and NA of an AIV sample from a single reaction. A panel of 77 influenza strains was tested representing the entire assortment of the two antigens. 100% (77/77) of the samples tested were identified as AIV and 97% (75/77) were subtyped correctly in accordance with previous examinations performed by classical diagnostic methods. Testing of heterologous pathogens verified the specificity of the assay. This assay is a convenient and practical tool for the study of AIVs, providing important HA and NA data more rapidly than conventional methods.