2007 Annual Report
The possibility of mechanical transmission of VSV by C. sonorensis was examined by testing frass from infected insects for virus by immunoblotting, real time PCR and virus isolation. Preliminary results show that VSV antigen can be detected by immunoblotting and VSV mRNA can be detected by rt-PCR. Infectious virus has yet to be isolated.
Transovarial VSV transmission studies have begun using C. sonorensis. Preliminary results suggest that VSV can be vertically transmitted from infected adult females to their progeny. F1 eggs, larvae, and emerged adults have been confirmed as VSV positive by real time PCR, western blotting, and virus isolation.
ABADRL is working with the Wyoming State Game and Fish Department (WYSGFD) and the USDA-ARS virus and prion disease of livestock research unit at Ames, Iowa to study the possible roles of insects in mechanical transmission of Chronic Wasting Disease (CWD). Preliminary research at a WYSGFD outdoor facility identified several arthropod species feeding on CWD infected elk or elk by-products. Over 300 adult insects have been collected, identified, and are stored at -80oC for prion detection. A subset of blood fed stable flies was pulled for blood meal identification.
ABADRL is working with Colorado State University, Department of Microbiology, Immunology and Pathology to study the possible role biting flies play in transmitting CWD. Six cages containing 300-500 female C. sonorensis midges were allowed to feed on blood spiked with CWD positive brain material or unspiked blood. Two cages were frozen at each time point: immediately post feeding, three days post feeding, and seven days post feeding. Prion detection assays are being optimized for testing insects. Mouthparts, midguts and salivary glands will be tested for prion contamination, uptake, and dissemination respectively.
A newly established method of collecting secreted C. sonorensis saliva has been used to obtain quantities of clean saliva for analysis by two-dimensional electrophoresis. Thus far, approximately 20 protein spots have been analyzed by mass spectrophotometry.
Midguts have been dissected from C. sonorensis given water, sugar water, blood, or blue tongue virus spiked blood to look for differences in protein expression in the midgut over time.
Experiments were performed to determine bluetongue virus (BTV) persistence in colonized C. sonorensis. Assays developed can distinguish between competent, virus persistent, and virus RNA free specimens.
Blood meal analyses were performed on field collected mosquitoes in the Powder River Basin, WY and Medicine Lake, MT. Results indicate a wide range of hosts including humans, livestock, and wildlife.
Determinations of the presence of West Nile virus (WNV), BTV, and Q fever in field collected specimens were made and are continuing. WNV and BTV have been confirmed in some insect samples.
Hunt, G.J., Schmidtmann, E.T. 2005. Care, maintenance, and experimental infection of biting midges. The Biology of Disease Vector 2nd Edition.
Langner, K.F.A., K.E. Darpel, E. Denison, B.S. Drolet, W. Leibold, P.S. Mellor, P.P.C. Mertens, M. Nimtz, I. Greiser-Wilke. 2007. Collection and analysis of salivary proteins from the biting midge Culicoides nubeculosus (Diptera: Ceratopogonidae). Journal of Medical Entomology 44(2):238-248.
Schmidtmann, E.T. 2006. Testing the relationship between dissolved salts in aquatic habitats and immature populations of the culicoides variipennis complex (diptera:ceratopogonidae). Environmental Entomology 35(5):1154-1160.
Schmidtmann, E.T., J. Lloyd, R.J. Bobian, R. Kumar, J.W. Waggoner, W.J. Tabachnick,and D. Legg. 2001. Suppression of mosquito (Diptera: Culicidae) and black fly (Diptera: Simuliidae) blood feeding from hereford cattle and ponies treated with permethrin. Journal of Medical Entomology. 38(5):728-734.
Borowicz, V., Alessandro, R.T., Albrecht, U., Mayer, R.T. 2005. Effects of nutrient supply and below-ground herbivory by Diaprepes abbreviatus L. (Coleoptera: Curculionidae) on citrus growth and mineral content. Applied Soil Ecology. 28:113-124.
Williams, Martin R., Juan Garcia, Kristine E. Bennett, Bernarda Molina, Stephen E. Aspen, and Harry M. Savage. 2007. First Records for Culex (Melaniconion) limacifer Komp and Culex (Melaniconion) dunni Dyar from Guatemala. 2007. JAMCA. 23(1):78-79.
O'Toole, D., Perez De Leon, A.A., Hearne, C., Mcholland, L.E., Yun, L., Tabachnick, W. 2003. Papular Dermatitis Induced in Guinea Pig by Biting Midge Culicoides Sonorensis (Diptera: Ceratopogonidaie). Journal of Veterinary Diagnostic Investigation. 15:67-71.
Mullens, B., Gerry, A., Lysyk, T., Schmidtmann, E.T. 2004. Environmental effects on vector competence and virogenesis of bluetongue virus in Culicoides: interpreting laboratory data in a field context. Veterinaria Italiana 40(3):160-166.