title: Characterization of a small plaque variant of West Nile virus isolated in New York in 2000.
abstract: A small-plaque variant (SP) of West Nile virus (WNV) was isolated in Vero cell culture from kidney tissue of an American crow collected in New York in 2000. The in vitro growth of the SP and parental (WT) strains was characterized in mammalian (Vero), avian (DF-1 and PDE), and mosquito (C6/36) cells. The SP variant replicated less efficiently than did the WT in Vero cells. In avian cells, SP growth was severely restricted at high temperatures, suggesting that the variant is temperature sensitive. In mosquito cells, growth of SP and WT was similar, but in vivo in Culex pipiens (L.) there were substantial differences. Relative to WT, SP exhibited reduced replication following intrathoracic inoculation and lower infection, dissemination, and transmission rates following oral infection. Analysis of the full length sequence of the SP variant identified sequence differences which led to only two amino acid substitutions relative to WT, prM P54S and NS2A V61A.
authors.affiliation: The Arbovirus Laboratories, Wadsworth Center, New York State Department of Health, Slingerlands, NY 12159, USA.
authors.forename: Yongqing
authors.initials: Y
authors.lastname: Jia
authors.forename: Robin M
authors.initials: RM
authors.lastname: Moudy
authors.forename: Alan P
authors.initials: AP
authors.lastname: Dupuis
authors.forename: Kiet A
authors.initials: KA
authors.lastname: Ngo
authors.forename: Joseph G
authors.initials: JG
authors.lastname: Maffei
authors.forename: Greta V S
authors.initials: GV
authors.lastname: Jerzak
authors.forename: Mary A
authors.initials: MA
authors.lastname: Franke
authors.forename: Elizabeth B
authors.initials: EB
authors.lastname: Kauffman
authors.forename: Laura D
authors.initials: LD
authors.lastname: Kramer
mesh_terms: D000330:Aedes / Q000821:virology; D000818:Animals; D001715:Bird Diseases / Q000821:virology; D002522:Chlorocebus aethiops; D046368:Crows / Q000821:virology; D014644:Genetic Variation; D007303:Insect Vectors / Q000502:physiology / Q000821:virology; D009518:New York / Q000453:epidemiology; D013696:Temperature; D014709:Vero Cells; D014779:Virus Replication / Q000502:physiology*; D014901:West Nile Fever / Q000453:epidemiology / Q000821:virology*; D014902:West Nile virus / Q000145:classification / Q000235:genetics* / Q000502:physiology