title: Reduced avian virulence and viremia of West Nile virus isolates from Mexico and Texas.
abstract: A West Nile virus (WNV) isolate from Mexico (TM171-03) and BIRD1153, a unique genotype from Texas, have exhibited reduced murine neuroinvasive phenotypes. To determine if murine neuroinvasive capacity equates to avian virulence potential, American crow (Corvus brachyrhynchos) and house sparrows (Passer domesticus) were experimentally inoculated with representative murine neuroinvasive/non-neuroinvasive strains. In both avian species, a plaque variant from Mexico that was E-glycosylation competent produced higher viremias than an E-glycosylation-incompetent variant, indicating the potential importance of E-glycosylation for avian replication. The murine non-neuroinvasive BIRD1153 strain was significantly attenuated in American crows but not house sparrows when compared with the murine neuroinvasive Texas strain. Despite the loss of murine neuroinvasive properties of nonglycosylated variants from Mexico, our data indicate avian replication potential of these strains and that unique WNV virulence characteristics exist between murine and avian models. The implications of reduced avian replication of variants from Mexico for restricted WNV transmission in Latin America is discussed.
authors: Division of Vector-borne Diseases, Centers for Disease Control and Prevention, Fort Collins, Colorado 80521, USA. abrault@cdc.gov
authors: Aaron C
authors: AC
authors: Brault
authors: Stanley A
authors: SA
authors: Langevin
authors: Wanichaya N
authors: WN
authors: Ramey
authors: Ying
authors: Y
authors: Fang
authors: David W C
authors: DW
authors: Beasley
authors: Christopher M
authors: CM
authors: Barker
authors: Todd A
authors: TA
authors: Sanders
authors: William K
authors: WK
authors: Reisen
authors: Alan D T
authors: AD
authors: Barrett
authors: Richard A
authors: RA
authors: Bowen
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D001483:Base Sequence; D001717:Birds / Q000821:virology*; D017931:DNA Primers; D006031:Glycosylation; D008800:Mexico; D013781:Texas; D014774:Virulence; D014902:West Nile virus / Q000276:immunology / Q000302:isolation & purification / Q000472:pathogenicity*
chemical_list: D000914:Antibodies, Viral; D017931:DNA Primers