Location: Foreign Animal Disease Research
2012 Annual Report
Specific objectives include: (1) Determine optimal route of direct inoculation of donor pigs for contact experiments through the comparison of inoculation routes. (2) Characterize FMDV acute pathogenesis parameters of infection in contact transmission studies using FMDV serotype O. (3) Characterize FMDV post-acute pathogenesis parameters of infection in contact transmission studies using FMDV, serotype O. (4) Characterize FMDV chronic pathogenesis parameters of infection in contact transmission studies using FMDV serotypes A and Asia 1.
During FY 2012 we conducted initial experimental studies including optimization of novel systems for intra-oral (IO) and intra-nasal (IN) inoculation of swine with FMDV serotype O. Results indicate that the IO system produces reproducible and highly synchronized clinical infection, with a high degree of similarity between individual animals. This IO inoculation system utilizes a more natural route of virus exposure in comparison to the commonly used techniques of inoculation through direct injection of virus into the heel bulb of the animals. This optimized system is therefore valuable for studies investigating the pathogenesis of acute and post-acute FMDV infection in pigs.
Tissue samples obtained from necropsies of pigs during acute (24-48 hours post infection), as well as late (35 days post infection) phases of infection have been analyzed for the presence of FMDV using a trimodal FMDV detection strategy of virus isolation, RT-PCR, immunomicroscopy. Preliminary findings from these initial investigations have indicated that some swine tissues contain FMDV RNA up to 35 days post inoculation (dpi), but no infectious FMDV has been recovered.
No technologies were transferred or publications have been prepared in FY 2012.