Location: Foreign Arthropod Borne Animal Disease Research
Project Number: 3022-32000-062-013-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 1, 2023
End Date: Aug 31, 2026
Objective:
Vesicular stomatitis (VS) is a viral disease of livestock which causes severe vesicles and ulceration in infected animals. The causative agent, VS virus (VSV) is transmitted by insects and also by direct contact between animals. The disease, in cattle and pigs resembles foot-and-mouth disease, a devastating disease of livestock. Economic losses are due to direct production losses that it causes in infected herds and the implementation of quarantine restrictions that affect animal trade.
Therefore, it is critical to characterize the viral strains causing outbreaks in North America. This research project seeks to generate knowledge on the epidemiological factors associated with VSV emergence and to conduct molecular characterization of the strains causing epidemics to contribute to the vesicular disease surveillance systems in the USA, Canada and Mexico.
Specific objectives include:
1. Establish a research collaboration between the Cooperator and USDA to work together with Mexico’s SENASICA Laboratory in Vesicular Stomatitis Virus (VSV) characterization.
2. Identify VSV lineages circulating in Mexico and USA using genetic sequencing and phylogenetic analysis.
3. Determine the spatial and temporal distribution of VSV outbreaks in Mexico and the USA.
4. Improve diagnostic tests for the detection of VSV RNA and VSV serum antibodies in field samples.
5. Conduct pathogenesis studies using the recombinant VSV generated by ARS.
Approach:
1. Viral strains: Viral strains occurring in Mexico and the USA from 2023 to 2026 from animals naturally infected by VSV will be considered as a part of this research. In Mexico regional veterinarians carry out investigations as a part of the vesicular disease surveillance program and samples are sent to SENASICA-CPA laboratory, where different tests (Antigen ELISA, RT-PCR, viral isolation) will be conducted in order to rule out the presence of foot and mouth disease virus and other vesicular diseases. Viral samples identified as positive for VSV in Mexico are available in the viral repository of SENASICA- CPA, will be used for genomic characterization and comparison with samples obtained in the USA.
2. Viral genetic characterization: Viral genetic sequencing will be carried out using two approaches, partial genomic sequence using P region primers as previously performed at ARS and CFIA. Additional hypervariable regions of previously determined VSV-NJ P sequences from GenBank will be used in the phylogenetic analysis that will be performed by Maximum likelihood optimality criterion. Viral strains of particular interest will have their genome sequenced using next generation sequencing. Sequences will be analyzed utilizing CLC Work Bench (Qiagen Corp) in close collaboration between ARS and Cooperator and Senasica-CPA personnel.
3. Improve diagnostic tests for the detection of VSV and VSV antibodies in field samples: In collaboration with the Canadian Food Inspection Agency (CFIA) National Centre for Foreign Animal Disease (NCFAD) field samples obtained through this study will be tested by existing real-time PCR and ELISA techniques. Sample exchanges authorized by SENASICA, will be done through a Material Transfer Research Agreement between SENASICA, ARS and CFIA.
4. Pathogenesis studies in pigs will be conducted to test virulence of a VS-NJV mutant produced by ARS, PIADC using a VS-NJV infectious clone. Three pathogenesis studies will be performed using pigs to identify the role of different gene mutations on VSV virulence.
