Deletion of the NSm virulence gene of rift valley fever virus inhibits virus replication in and dissemination from the midgut of Aedes aegypti mosquitoes
Autor(es): Kading, Rebekah C.; Crabtree, Mary B.; Bird, Brian H.; Nichol, Stuart T.; Erickson, Bobbie Rae; Horiuchi, Kalanthe; Biggerstaff, Brad J.; Miller, Barry R.
Resumo: Rift Valley fever virus (RVFV) is a mosquito-borne virus endemic to Africa. Outbreaks of RVFV have resulted in devastating morbidity and mortality in livestock and humans. A novel RVFV vaccine strain has been developed in which two virulence genes, NSs and NSm, have been deleted from the RVFV genome. Previously, we demonstrated that deletion of NSm also significantly reduced the ability of Aedes aegypti mosquitoes to transmit RVFV. The objective of this study was to track the spread (dissemination) of wild type RVFV (rRVF-wt) and RVFV lacking the NSm virulence gene (rRVF- Delta NSm) through different tissues in the mosquito body over time by staining lengthwise slices of infected mosquitoes with fluorescent antibody specific to RVFV. We found that midgut infections in mosquitoes exposed to rRVF-wt were extensive, whereas midgut infections in mosquitoes infected with rRVF- Delta NSm were confined to only one or a few small foci. Our data provide supporting evidence that the NSm virulence gene has a functional role in mosquitoes by helping RVFV establish an infection in, and escape from, the midgut.
Palavras-Chave: Virulence; Endemic species; Genes; Replication; Pest control; Rift valleys; Aquatic insects; Mortality causes; Public health; Genomes; Mortality; Data processing; Rift Valley fever; Infection; Morbidity; Livestock; Antibodies; Gene deletion; Midgut; Vaccines
Imprenta: Plos Neglected Tropical Diseases, v. 8, n. 2, 2014.
Descritores: Aedes aegypti - Virus ; Aedes aegypti - Vaccine ; Aedes aegypti - Public health
Data de publicação: 2014
