2008 Annual Report 1a.Objectives (from AD-416) Study the development of immunity to Leptospira borgpetersenii serovar hardjo in cattle, comparing vaccinated and naive animals. This research specifically supports research in milestone Objective 3 for year 2, contributing to the characterization of immune responses to spirochetal proteins and leading to testing of Leptospira vaccine candidates. 1b.Approach (from AD-416) ARS will provide media and conduct PCR and fluorescent antibody assays of clinical samples to help RTI interpret the infection data for their study being done on contract, and costs for these studies will be reimbursed by RTI. RTI will supply additional blood and tissue samples to ARS that will enable ARS to study specific aspects of the cattle immune response to infection. RTI needed additional bacteriological media, the most expensive portion of the reagent costs and a time critical element of the study. The additional funds requested are needed only to cover the costs of reagents allowing completion of the planned study. 3.Progress Report This project was initiated in FY2007 and involved evaluation of clinical samples generated during experimental infection of cattle. Methods for polymerase chain reaction (PCR) detection of Leptospira borgpetersenii serovar Hardjo were refined during this study and the progression of urinary shedding of bacteria was examined using PCR and fluorescent antibody analysis. During FY2008, data from previous research was evaluated and plans for a new study developed. Activities of the project covered under this trust are monitored by periodic e-mail and phone conversations between ARS and Rural Technologies, Inc., and an on-site visit by the ARS investigator at the company facility. This project addresses NP 103, component 3, problem statement 3B.