Volume 91, Issue 5
  • ISSN: 0002-9637
  • E-ISSN: 1476-1645



St. Louis encephalitis virus (SLEV) has shown greater susceptibility to oral infectivity than West Nile virus (WNV) in mosquitoes. To identify the viral genetic elements that modulate these disparate phenotypes, structural chimeras (WNV–pre-membrane [prM] and envelope [E] proteins [prME]/SLEV.IC (infectious clone) and SLEV-prME/WNV.IC) were constructed in which two of the structural proteins, the prM and E, were interchanged between viruses. Oral dose–response assessment with the chimeric/parental WNV and SLEV was performed to characterize the infection phenotypes in mosquitoes by artificial blood meals. The median infectious dose required to infect 50% of with WNV was indistinguishable from that of the SLEV-prME/WNV.IC chimeric virus. Similarly, SLEV and WNV-prME/SLEV.IC virus exhibited an indistinguishable oral dose–response relationship in . Infection rates for WNV.IC and SLEV-prME/WNV.IC were significantly lower than SLEV.IC and WNV-prME/SLEV.IC infection rates. These results indicated that WNV and SLEV oral infectivities are not mediated by genetic differences within the prM and E proteins.


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  1. Komar N, , 2003. West Nile virus: epidemiology and ecology in North America. Adv Virus Res 61: 185234.[Crossref] [Google Scholar]
  2. Blitvich BJ, , 2008. Transmission dynamics and changing epidemiology of West Nile virus. Anim Health Res Rev 9: 7186.[Crossref] [Google Scholar]
  3. Bernard KA, Maffei JG, Jones SA, Kauffman EB, Ebel GD, Dupuis AP, 2nd Ngo KA, Nicholas DC, Young DM, Shi PY, Kulasekera VL, Eidson M, White DJ, Stone WB, Kramer LD, NY State West Nile Virus Surveillance Team; , 2001. West Nile virus infection in birds and mosquitoes, New York State, 2000. Emerg Infect Dis 7: 679685.[Crossref] [Google Scholar]
  4. Kulasekera V, Kramer LD, Nasci RS, Mostashari F, Cherry B, Trock SC, Glaser C, Miller JR, , 2001. West Nile virus infection in mosquitoes, birds, horses, and humans, Staten Island, New York, 2000. Emerg Infect Dis 7: 722725.[Crossref] [Google Scholar]
  5. Turell MJ, Dohm DJ, Sardelis MR, O'Guinn ML, Andreadis TG, Blow JA, , 2005. An update on the potential of north American mosquitoes (Diptera: Culicidae) to transmit West Nile Virus. J Med Entomol 42: 5762.[Crossref] [Google Scholar]
  6. Goddard LB, Roth AE, Reisen WK, Scott TW, , 2002. Vector competence of California mosquitoes for West Nile virus. Emerg Infect Dis 8: 13851391.[Crossref] [Google Scholar]
  7. Reisen W, , 2003. Epidemiology of St. Louis encephalitis virus. Adv Virus Res 61: 139183.[Crossref] [Google Scholar]
  8. Day JF, , 2001. Predicting St. Louis encephalitis virus epidemics: lessons from recent, and not so recent, outbreaks. Annu Rev Entomol 46: 111138.[Crossref] [Google Scholar]
  9. Reisen WK, Fang Y, Martinez VM, , 2005. Avian host and mosquito (Diptera: Culicidae) vector competence determine the efficiency of West Nile and St. Louis encephalitis virus transmission. J Med Entomol 42: 367375.[Crossref] [Google Scholar]
  10. Meyer RP, Hardy JL, Presser SB, , 1983. Comparative vector competence of Culex tarsalis and Culex quinquefasciatus from the Coachella, Imperial, and San Joaquin Valleys of California for St. Louis Encephalitis Virus. Am J Trop Med Hyg 32: 305311. [Google Scholar]
  11. Pesko K, Mores CN, , 2009. Effect of sequential exposure on infection and dissemination rates for West Nile and St. Louis Encephalitis Viruses in Culex quinquefasciatus . Vector Borne Zoonotic Dis 9: 281286.[Crossref] [Google Scholar]
  12. Lindenbach B, Thiel H, Rice C, , 2007. Flaviviridae: the viruses and their replication. Fields Virology. Philadelphia, PA: Lippincott-Raven Publishers, 11011152. [Google Scholar]
  13. Moudy RM, Payne AF, Dodson BL, Kramer LD, , 2011. Requirement of glycosylation of West Nile Virus envelope protein for infection of, but not spread within, Culex quinquefasciatus mosquito vectors. Am J Trop Med Hyg 85: 374378.[Crossref] [Google Scholar]
  14. Moudy RM, Zhang B, Shi P-Y, Kramer LD, , 2009. West Nile virus envelope protein glycosylation is required for efficient viral transmission by Culex vectors. Virology 387: 222228.[Crossref] [Google Scholar]
  15. Erb SM, Butrapet S, Moss KJ, Luy BE, Childers T, Calvert AE, Silengo SJ, Roehrig JT, Huang CYH, Blair CD, , 2010. Domain-III FG loop of the dengue virus type 2 envelope protein is important for infection of mammalian cells and Aedes aegypti mosquitoes. Virology 406: 328335.[Crossref] [Google Scholar]
  16. McElroy KL, Tsetsarkin KA, Vanlandingham DL, Higgs S, , 2006. Role of the yellow fever virus structural protein genes in viral dissemination from the Aedes aegypti mosquito midgut. J Gen Virol 87: 29933001.[Crossref] [Google Scholar]
  17. Maharaj PD, Anishchenko M, Langevin SA, Fang Y, Reisen WK, Brault AC, , 2012. Structural gene (prME) chimeras of St Louis encephalitis virus and West Nile virus exhibit altered in vitro cytopathic and growth phenotypes. J Gen Virol 93: 3949.[Crossref] [Google Scholar]
  18. Kinney RM, Huang CY, Whiteman MC, Bowen RA, Langevin SA, Miller BR, Brault AC, , 2006. Avian virulence and thermostable replication of the North American strain of West Nile virus. J Gen Virol 87: 36113622.[Crossref] [Google Scholar]
  19. Beasley D, Whiteman M, Zhang S, Huang C, Schneider B, Smith D, Gromowski G, Higgs S, Kinney R, Barrett A, , 2005. Envelope protein glycosylation status influences mouse neuroinvasion phenotype of genetic lineage 1 West Nile virus strains. J Virol 79: 83398347.[Crossref] [Google Scholar]
  20. Vanlandingham DL, Schneider BS, Klingler K, Fair J, Beasley D, Huang J, Hamilton P, Higgs S, , 2004. Real-Time reverse transcriptase–polymerase chain reaction quantification of West Nile virus transmitted by Culex pipiens quinquefasciatus . Am J Trop Med Hyg 71: 120123. [Google Scholar]
  21. Bellamy R, Kardos E, , 1958. A strain of Culex tarsalis Coq. reproducing without blood meals. Mosq News 18: 132135. [Google Scholar]
  22. Miller BR, , 1987. Increased yellow fever virus infection and dissemination rates in Aedes aegypti mosquitoes orally exposed to freshly grown virus. Trans R Soc Trop Med Hyg 81: 10111012.[Crossref] [Google Scholar]
  23. Beaty BJ, Calisher CH, Shope RE, Lennette EH, Lennette DA, Lennette ET, , 1995. Diagnostic procedures for viral, rickettsial, and chlamydial infections. , eds. Arboviruses. Washinton, DC: American Public Health Association, 189212. [Google Scholar]
  24. Reisen WK, Barker CM, Fang Y, Martinez VM, , 2008. Does variation in Culex (Diptera: Culicidae) vector competence enable outbreaks of West Nile Virus in California? J Med Entomol 45: 11261138.[Crossref] [Google Scholar]
  25. Ciota AT, Lovelace AO, Jones SA, Payne A, Kramer LD, , 2007. Adaptation of two flaviviruses results in differences in genetic heterogeneity and virus adaptability. J Gen Virol 88: 23982406.[Crossref] [Google Scholar]
  26. Ciota AT, Jia Y, Payne AF, Jerzak G, Davis LJ, Young DS, Ehrbar D, Kramer LD, , 2009. Experimental passage of St. Louis Encephalitis Virus in vivo in mosquitoes and chickens reveals evolutionarily significant virus characteristics. PLoS ONE 4: e7876.[Crossref] [Google Scholar]
  27. Moudy RM, Meola MA, Morin L-LL, Ebel GD, Kramer LD, , 2007. A newly emergent genotype of West Nile Virus is transmitted earlier and more efficiently by Culex mosquitoes. Am J Trop Med Hyg 77: 365370. [Google Scholar]
  28. Miller BR, , 1987. Increased yellow fever virus infection and dissemination rates in Aedes aegypti mosquitoes orally exposed to freshly grown virus. Trans R Soc Trop Med Hyg 81: 10111012.[Crossref] [Google Scholar]
  29. Reisen WK, Lothrop HD, Wheeler SS, Kennsington M, Gutierrez A, Fang Y, Garcia S, Lothrop B, , 2008. Persistent West Nile virus transmission and the apparent displacement St. Louis Encephalitis Virus in southeastern California, 2003–2006. J Med Entomol 45: 494508.[Crossref] [Google Scholar]
  30. Sardelis MR, Turell MJ, Dohm DJ, O'Guinn ML, , 2001. Vector competence of selected North American Culex and Coquillettidia mosquitoes for West Nile virus. Emerg Infect Dis 7: 10181022.[Crossref] [Google Scholar]
  31. Ebel GD, Rochlin I, Longacker J, Kramer LD, , 2005. Culex restuans (Diptera: Culicidae) relative abundance and vector competence for West Nile Virus. J Med Entomol 42: 838843.[Crossref] [Google Scholar]
  32. Turell MJ, O'Guinn ML, Dohm DJ, Jones JW, , 2001. Vector competence of North American mosquitoes (Diptera: Culicidae) for West Nile virus. J Med Entomol 38: 130134.[Crossref] [Google Scholar]
  33. Ebel G, Carricaburu J, Young D, Bernard K, Kramer L, , 2004. Genetic and phenotypic variation of West Nile virus in New York, 2000–2003. Am J Trop Med Hyg 71: 493500. [Google Scholar]
  34. Brackney DE, Scott JC, Sagawa F, Woodward JE, Miller NA, Schilkey FD, Mudge J, Wilusz J, Olson KE, Blair CD, Ebel GD, , 2010. C6/36 Aedes albopictus cells have a dysfunctional antiviral RNA interference response. PLoS Negl Trop Dis 4: e856.[Crossref] [Google Scholar]
  35. Richards SL, Lord CC, Pesko KN, Tabachnick WJ, , 2010. Environmental and biological factors influencing Culex pipiens quinquefasciatus (Diptera: Culicidae) vector competence for West Nile Virus. Am J Trop Med Hyg 83: 126134.[Crossref] [Google Scholar]
  36. Hanley KA, Manlucu LR, Gilmore LE, Blaney JE, Hanson CT, Murphy BR, Whitehead SS, , 2003. A trade-off in replication in mosquito versus mammalian systems conferred by a point mutation in the NS4B protein of dengue virus type 4. Virology 312: 222232.[Crossref] [Google Scholar]
  37. Hanley KA, Goddard LB, Gilmore LE, Scott TW, Speicher J, Murphy BR, Pletnev AG, , 2005. Infectivity of West Nile/dengue chimeric viruses for West Nile and dengue mosquito vectors. Vector Borne Zoonotic Dis 5: 110.[Crossref] [Google Scholar]
  38. McElroy KL, Tsetsarkin KA, Vanlandingham DL, Higgs S, , 2006. Manipulation of the Yellow fever virus non-structural genes 2A and 4B and the 3′non-coding region to evaluate genetic determinants of viral dissemination from the Aedes aegypti midgut. Am J Trop Med Hyg 75: 11581164. [Google Scholar]
  39. Liu WJ, Wang XJ, Clark DC, Lobigs M, Hall RA, Khromykh AA, , 2006. A single amino acid substitution in the West Nile Virus nonstructural protein NS2A disables its ability to inhibit alpha/beta interferon induction and attenuates virus virulence in mice. J Virol 80: 23962404.[Crossref] [Google Scholar]
  40. Hardy J, Houk E, Kramer L, Reeves W, , 1983. Intrinsic factors affecting vector competence of mosquitoes for arboviruses. Annu Rev Entomol 28: 229.[Crossref] [Google Scholar]
  41. Bennett K, Olson K, Munoz M de L, Fernandez-Salas I, Farfan-Ale J, Higgs S, Black WC, 4th Beaty B, , 2002. Variation in vector competence for dengue 2 virus among 24 collections of Aedes aegypti from Mexico and the United States. Am J Trop Med Hyg 67: 8592. [Google Scholar]
  42. Smartt CT, Erickson JS, , 2008. Bloodmeal-induced differential gene expression in the disease vector Culex nigripalpus (Diptera: Culicidae). J Med Entomol 45: 326330.[Crossref] [Google Scholar]
  43. Sanders HR, Evans AM, Ross LS, Gill SS, , 2003. Blood meal induces global changes in midgut gene expression in the disease vector, Aedes aegypti . Insect Biochem Mol Biol 33: 11051122.[Crossref] [Google Scholar]
  44. Smartt CT, Richards SL, Anderson SL, Erickson JS, , 2009. West Nile Virus Infection Alters Midgut Gene Expression in Culex pipiens quinquefasciatus Say (Diptera: Culicidae). Am J Trop Med Hyg 81: 258263. [Google Scholar]
  45. Xi Z, Ramirez JL, Dimopoulos G, , 2008. The Aedes aegypti toll pathway controls dengue virus infection. PLoS Pathog 4: e1000098.[Crossref] [Google Scholar]
  46. Brackney DE, Beane JE, Ebel GD, , 2009. RNAi targeting of West Nile Virus in mosquito midguts promotes virus diversification. PLoS Pathog 5: e1000502.[Crossref] [Google Scholar]
  47. Blair CD, , 2011. Mosquito RNAi is the major innate immune pathway controlling arbovirus infection and transmission. Future Microbiol 6: 265277.[Crossref] [Google Scholar]
  48. Pusch O, Boden D, Silbermann R, Lee F, Tucker L, Ramratnam B, , 2003. Nucleotide sequence homology requirements of HIV-1-specific short hairpin RNA. Nucleic Acids Res 31: 64446449.[Crossref] [Google Scholar]
  49. Richards SL, Lord CC, Pesko K, Tabachnick WJ, , 2009. Environmental and biological factors influencing Culex pipiens quinquefasciatus Say (Diptera: Culicidae) vector competence for Saint Louis Encephalitis Virus. Am J Trop Med Hyg 81: 264272. [Google Scholar]
  50. Ding S-W, Voinnet O, , 2007. Antiviral immunity directed by small RNAs. Cell 130: 413426.[Crossref] [Google Scholar]
  51. Schnettler E, Sterken MG, Leung JY, Metz SW, Geertsema C, Goldbach RW, Vlak JM, Kohl A, Khromykh AA, Pijlman GP, , 2012. Noncoding flavivirus RNA displays RNA interference suppressor activity in insect and mammalian cells. J Virol 86: 1348613500.[Crossref] [Google Scholar]
  52. Hussain M, Torres S, Schnettler E, Funk A, Grundhoff A, Pijlman GP, Khromykh AA, Asgari S, , 2012. West Nile virus encodes a microRNA-like small RNA in the 3′ untranslated region which up-regulates GATA4 mRNA and facilitates virus replication in mosquito cells. Nucleic Acids Res 40: 22102223.[Crossref] [Google Scholar]

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  • Received : 07 May 2014
  • Accepted : 21 Jul 2014
  • Published online : 05 Nov 2014

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