Molecular determinants of virulence of West Nile virus in North America.

摘要: West Nile virus (WNV) is a mosquito-borne flavivirus that until very recently had not been found in the Americas. In 1999, there was an outbreak of encephalitis New York and surrounding areas, involving 62 human cases, including 7 fatalities. The has subsequently become established United States America (U.S.) with 4156 284 deaths, 2002. WNV strains U.S. are members “lineage I”, genetic grouping includes viruses from Europe, Asia Africa. Molecular epidemiologic studies indicate two variants emerged major variant most parts U.S., while minor identified only on southeast coast Texas. Investigation mouse hamster models demonstrated highly neurovirulent neuroinvasive these laboratory rodents. Other strains, such as Ethiopia 76a lineage I, represent important which can be used to elucidate molecular basis virulence attenuation WNY. To identify putative determinants attenuation, we have undertaken comparative nucleotide sequencing results show differ by 5 amino acids envelope (E) protein, loss glycosylation site . Comparison our panel 27 suggests E protein determinant phenotype.