For the purpose of developing an improved experimental model for studies of foot-and-mouth disease virus (FMDV) infection in cattle, three different experimental systems based on natural or simulated natural virus exposure were compared under standardized experimental conditions. Ante-mortem infection dynamics were characterized in cattle exposed to FMDV through a novel, simulated natural intranasopharyngeal (INP) inoculation system or through standardized and controlled systems of within- or between-species direct contact exposure (cattle-to-cattle or pig-to-cattle). All three systems were efficient in causing synchronous, generalized foot-and-mouth disease in cattle exposed to one of three different strains of FMDV representing serotypes O, A and Asia1. There was more within-group variation in the timing of clinical infection following natural and simulated natural virus exposure systems when compared with the conventionally used system of needle inoculation (intraepithelial lingual inoculation). However, the three optimized exposure systems described herein have the advantage of closely simulating field conditions by utilizing natural routes of primary infection, thereby facilitating engagement of mucosal host defence mechanisms. Overall, it is concluded that INP inoculation and standardized systems of direct contact exposure provide effective alternatives to conventional (needle) inoculation systems for studies in which it is desirable to simulate the natural biology of FMDV infection.
Bibliographical noteFunding Information:
This work was funded in part by CRIS project 1940-32000-057-00D (USDA, Agricultural Research Service), as well as through an interagency agreement with the Science and Technology Directorate of the US Department of Homeland Security under Award Number HSHQDC-11-X-00189. CS was recipient of PIADC Research Participation Program fellowships, administered by the Oak Ridge Institute for Science and Education (ORISE) through an interagency agreement with the US Department of Energy. The sponsors had no involvement in the study design, in the collection, analysis and interpretation of data, in the writing of the manuscript, or in the decision to submit the manuscript for publication. The authors acknowledge and appreciate expert laboratory support provided by G. R. Smoliga, E. J. Hartwig, S. J. Pauszek and E. Bishop. The first two authors contributed equally to this work.
- animal models
- foot-and-mouth disease virus