RESUMO
The first two isolates of H9N2 influenza virus in Israel were collected from turkey and chicken hosts in May 2000. The actual epizootic of the H9N2 virus started in December 2001, after a 1.5-year period of silence, and still continues. A total of more than 500 isolations from turkeys and chickens were registered during the outbreaks. The present study has revealed some genetic peculiarities among the local isolates, namely: all the isolates belong to the same G1-like phylogenetic lineage, within which they form a single group, which, in turn, is divided into three subgroups in the cases of the HA and NP genes, and two subgroups in the case of the NA gene. The results present a basis for suggesting the existence of two parallel evolutionary trends originating from the same local "prototype" isolate.
Assuntos
Glicoproteínas de Hemaglutininação de Vírus da Influenza/classificação , Vírus da Influenza A Subtipo H9N2/genética , Influenza Aviária/epidemiologia , Neuraminidase/classificação , Proteínas de Ligação a RNA/classificação , Proteínas do Core Viral/classificação , Substituição de Aminoácidos/genética , Animais , Galinhas/genética , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Vírus da Influenza A Subtipo H9N2/isolamento & purificação , Influenza Aviária/virologia , Israel/epidemiologia , Neuraminidase/genética , Proteínas do Nucleocapsídeo , Filogenia , Proteínas de Ligação a RNA/genética , Perus/virologia , Proteínas do Core Viral/genéticaRESUMO
The partial nucleotide sequences of the hemagglutinin (HA) genes of 72 H9N2 influenza viruses isolated from chickens and turkeys in Israel during the period 2000-2005 were genetically analyzed. The isolates possessed the three types of amino acid motif -R-S-S-R/G-L-, -R-S-N-R/G-L-, and -R-S-K-R/G-L- at the cleavage site of HA. Phylogenetic analyses showed that all Israeli isolates belonged to the same group which further divided into three closely related sub-groups. The HA genes of these isolates were related to the HA gene of A/chicken/Germany/R45/98 isolated from chicken in Germany in 1998.
