Location: Foreign Animal Disease Research
2013 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.
Finalized ongoing experiments with the objective of developing and optimizing novel simulated natural FMDV exposure systems for pigs. Experimental studies evaluating intra-orophasyngeal (IOP) and intra-nasopharyngeal inoculation of swine using FMDV serotype A were performed to extend the data previously generated during similar experimental studies using FMDV serotype O.
The results of these initial experimental studies suggest that the newly developed IOP inoculation system is preferred and advantageous for studies of FMDV pathogenesis in swine.
The potential for pigs to serve as hosts for persistent FMDV infection has been investigated through experimental studies with FMDV serotypes O, A, and Asia-1. Preliminary findings indicate that it is not possible to isolate infectious virus from porcine tissues during the late phase of infection (>28 days post infection). There is, however, a relatively high prevalence of retained FMDV degradation products, consisting of RNA and capsid antigen, in lymph nodes that drain specific lesion sites. The significance of these byproducts is unclear at this time.
Continued investigations of the acute pathogenesis of FMDV in pigs have been performed through time course experiments investigating viral dynamics and tissue distribution of virus in animals that have been euthanized at pre-determined time points from 6 to 72 hours post infection with FMDV serotype O and A. Analysis of samples obtained from performed animal studies is currently ongoing and will continue through November 2013 when this grant will expire. The outcome of this work will guide further efforts within this research objective.
No technologies have been transferred or publications produced during FY 2013.