An avian influenza virus (AIV), A/turkey/Israel/09 subtype H6N1, was isolated from turkey poults exhibiting typical pathology associated with AIV infection. The virus was characterized by RT-PCR using AIV subtype-specific primers and by the haemagglutination inhibition test using AIV subtype-specific antisera. The virus has an intravenous pathogenicity index of 0 and possessed a nucleotide sequence at the cleavage site of the hemagglutinin gene, PQIETR*GLF, associated with avian influenza viruses of low pathogenicity. Unlike the two previous H6N2 isolates originating from domestic ducks and mallard, the A/turkey/Israel/09 (H6N1) was isolated from turkeys. The gene sequences of the A/turkey/Israel/09 (H6N1) virus show divergence from the former Israeli H6 isolates. 1. Introduction The influenza viruses include three genera, A, B, and C within the family Orthomyxoviridae. Avian influenza viruses (AIVs), all of which are contained in the genus influenza virus A, are an economically important cause of disease in fowl and occasionally affect humans, pigs, and horses [1, 2]. Each genus of the virus is further subdivided into serotypes based on the surface proteins, consisting of 16 different hemagglutinin (H) and 9 neuraminidase (N) subtypes. While only a limited number of H and N subtypes are circulating in humans and other mammalian species, all the H and N subtypes are found in avian species [3, 4]. The genome of influenza A viruses consists of 8 unique segments of single-stranded negative sense RNA. The viral RNA segments encode 10 recognized gene products, PB1, PB2, and PA polymerases, H, NP, N, M1, M2, NS1, and NS2 proteins [5]. The H6 subtype is one of the most commonly recognized subtypes in domestic ducks in southern China [6, 7] and in migratory birds in North America and in Europe [8–10]. H6 viruses have caused several outbreaks in commercial poultry worldwide that resulted in decreased egg production and increased mortality [11–13]. During the Hong Kong H5N1 “bird flu” incident in 1997, an H6N1 avian influenza virus, teal/Hong Kong/W312/97 (W312), was isolated from birds in a live poultry market [14]. Genetic characterization of this virus revealed that except for the H gene, the remaining 7-gene segments were closely related to those of highly pathogenic avian influenza H5N1 viruses (HPAIVs) found in both poultry and humans [14]. The present study reports on the outbreak of avian influenza (AI) caused by an H6N1 subtype of AIV isolated during January 2009 in Kibbutz Gvulot, in the southern part of Israel. The present isolate, A/turkey/Israel/09
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