Project Number: 5410-32000-014-00
Project Type: Appropriated

Start Date: Dec 10, 2004
End Date: Dec 09, 2009

Objective:
The goal of research is to protect U.S. livestock from vector-borne pathogens through knowledge of species vector competence, defining the influence of environmental factors on vector competence and distribution, and understanding insect susceptibility to pathogen infection at cellular and molecular levels. Within this objective, research will: 1) clarify and define the role of insects as vectors and reservoirs of pathogens that adversely affect livestock, humans, and wildlife; 2) determine the effects of environmental factors on transmission of pathogens by biting midges and mosquitoes; and 3) identify and characterize insect genomic and proteomic determinants that affect infection, replication, and transmission of arboviruses of concern to the U.S. livestock industry.

Approach:
Ecological data will be developed for criteria used to incriminate insect species that serve as vectors of obscure or little studied pathogens in nature. Emphasis will be placed on clarifying the role of sand flies, grasshoppers, and Culicoides as vectors and reservoirs of vesicular stomatitis viruses, as well as the role of both blood feeding and non-blood feeding insects in the natural transmission of prions. The role of environmental factors as determinants of insect vector distribution and susceptibility to arboviruses will be developed using geographic information system approaches to estimate vector distribution and pathogen susceptibility, thus enabling prediction of livestock risk for pathogen exposure. The midgut microbial flora of biting midges will be assessed using non-culture based molecular tests, such as T-RFLP, quantitative PCR or macro-arrays, and correlated with insect susceptibility to arbovirus infection. Arbovirus susceptibility and infection pathways in insect vectors will be investigated by identifying salivary gland and midgut proteins that will be analyzed by mass spectromety and compared with available protein databases and compared between blood-fed and non-blood fed individuals. RNA interference (RNAi) will be used to down regulate genes and thus identify the role of gene products in the susceptibility of insects to arbovirus infection. BSL-3; Pending.