Project Number: 1245-32000-096-00
Project Type: Appropriated

Start Date: Nov 10, 2011
End Date: Nov 09, 2016

Objective:
Objective 1: Identify genetic markers associated with parasite phenotypes that are resistant to anthelmintic drugs. Objective 2: Develop state-of-the-art assays to diagnose and quantify GI nematodes in ruminants resulting in better pasture management and reductions in anthelmintic dependency. Sub-Objective 2a: Determine the relative contribution of parasite genera in eggs from cattle harboring mixed nematode infections. Sub-Objective 2b: Develop a simple and rapid test for identifying nematode eggs. Objective 3: Identify parasite products that function as modulators of the host immune response.

Approach:
Objectives will be attained using molecular/genomic, immunological, and epidemiological techniques. The drug resistant phenotype in bovine nematodes results from mutation(s) and/or change(s) in transcriptional patterns in a subset of genes. Transcriptome sequencing will be used to develop markers for the resistance phenotype. State-of-the-art assays are required to diagnose and quantify GI nematodes to help reduce drug use. Two diagnostic tests will be developed: one using size fragment analysis, an offshoot of Sanger Sequencing technology to quantify infection levels of each parasite species, and a second using loop-mediated isothermal amplification (LAMP) technology for rapid testing in veterinary or regional clinical labs. Finally, parasite products that function as modulators of the host immune response will be identified by their ability to stimulate CD4+ T cell responses, and elicit cytokines known to be important in protection. Changes in host regulatory cells (Tregs) induced by the presence of parasites will also be studied to understand how the parasite down regulates or manipulates the host immune response to its benefit.