Virulence variation among isolates of western equine encephalitis virus in an outbred mouse model.

ABSTRACT: Little is known about viral determinants of virulence associated with western equine encephalitis virus (WEEV). Here, we have analysed six North American WEEV isolates in an outbred CD1 mouse model. Full genome sequence analyses showed < or =2.7 % divergence among the six WEEV isolates. However, the percentage mortality and mean time to death (MTD) varied significantly when mice received subcutaneous injections of 10(3) p.f.u. of each virus. Two WEEV strains, McMillan (McM) and Imperial 181 (IMP), were the most divergent of the six in genome sequence; McM caused 100 % mortality by 5 days post-infection, whereas IMP caused no mortality. McM had significantly higher titres in the brain than IMP. Similar differences in virulence were observed when McM and IMP were administered by aerosol, int

SUBMITTER: Logue CH 

PROVIDER: S-EPMC2887574 | biostudies-literature | 2009 Aug

REPOSITORIES: biostudies-literature