Within-host infection dynamics of a recent field isolate of foot-and-mouth disease virus (FMDV), serotype O, topotype South East Asia, lineage Myamar'98 were evaluated in sheep using four different systems for virus exposure. Two novel, simulated natural, inoculation systems consisting of intra-nasopharyngeal (INP) deposition and aerosol inoculation were evaluated in comparison with two conventional systems: coronary band inoculation and direct contact exposure. All four exposure systems were efficient in generating consistently severe, generalized FMD with synchronous clinical characteristics within exposure groups, indicating that this Myanmar98 strain is highly virulent in sheep. Clinical and virological dynamics were similarly rapid following INP- and coronary band inoculation, with both systems leading to significantly earlier detection of virus shedding when compared to aerosol inoculation and contact exposure. The data presented herein support application of the two optimized simulated natural inoculation systems as valid alternatives to conventionally used exposure systems for studies of FMDV pathogenesis and vaccinology in sheep. Furthermore, the data suggest that targeted exposure of the ovine pharynx is highly efficient for generating consistent FMDV infection, which supports critical involvement of this anatomic region as a site of primary virus replication in sheep.
Bibliographical noteFunding Information:
This study was a collaboration between the CSIRO-Australian Animals Health Laboratory and the Agricultural Research Service, USDA , who co-funded the work under collaborative agreement 58-1940-3-004 . Funding through CSIRO was provided in part by the livestock industries in Australia through the Cattle Council of Australia, Australian Dairy Farmers, Australian Lot Feeders Association, Wool Producers Australia, Sheepmeat Council of Australia, Australian Pork Limited and the Goat Industry Council of Australia through the Meat and Livestock Australia Donor Company matching arrangements with the Australian Government (Project PSH 0652). Animal Health Australia provided the project management service for all relevant industries. Additional funding came from ARS-CRIS Project 1940- 32000-057-00D . CS and HCF are recipients of Plum Island Animal Disease Center 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 . None of the funding sources had influence upon design or performance of experimental study, interpretation of results or writing of the manuscript. The Korean FMDV isolate was provided by Dr. Kwang-Nyeong Lee, Animal and Plant Quarantine Agency, Ministry of Agriculture, Food and Rural Affairs Republic of Korea. The authors thank Elizabeth Bishop, Ethan Hartwig and George Smoliga for processing of samples and Erin Howey for immunomicroscopy support.
Copyright 2015 Elsevier B.V., All rights reserved.
- Foot-and-mouth disease