tailieunhanh - Báo cáo khoa học: "Diversification of West Nile virus in a subtropical region"

Diversification of West Nile virus in a subtropical region | Virology Journal BioMed Central Open Access Diversification of West Nile virus in a subtropical region Daniel M Chisenhall and Christopher N Mores Address Louisiana State University School of Veterinary Medicine Department of Pathobiological Sciences Skip Bertman Dr. Baton Rouge LA 70803 USA Email Daniel M Chisenhall - dchisenh@ Christopher N Mores - cmores@ Corresponding author Published 16 July 2009 Received 28 February 2009 Virology Journal 2009 6 106 doi 1743-422X-6-106 Accepted 16 July 2009 This article is available from http content 6 1 106 2009 Chisenhall and Mores licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License http licenses by which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. Abstract__ Background West Nile virus WNV has spread across North Central and South America since its introduction in 1999. At the start of this spread Florida was considered a potentially important area with regards to transmission due to its geographic climatological and demographic conditions. Curiously the anticipated high levels of transmission or disease outbreaks have not been observed. As other studies have predicted that the lack of intense WNV transmission is not due to vector incompetence we sought to evaluate the role of viral strain diversity in WNV transmission in Florida. Therefore a phylogentic analysis was carried out on several isolates collected from three distinct locations in Florida. Results Contrasting with a positive control collected in Indian River County Florida during 2003 that contains the original NY99 genotype with valanine at amino acid 159 of the envelope region all of the isolates collected in 2005 contain the WN02 genotype composed of a substation with