RV Epidemiology and epitope characterization of RVA strains

from Canada

Douglas Marthaler, PhDAssistant Professor

University of Minnesota Veterinary Diagnostic Laboratory

Nitipong Homwong, Andres Diaz, Omer Nasser, Stephanie Rossow, and Max Ciarlet

Leman ConferenceSeptember 19th, 2016St. Paul, Minnesota

Rotavirus (RV)

Settembre et. al, 2011

• Family – Reoviridae– dsRNA virus– 11 segments– Eight species (RVA-RVH)

• Transmission– Fecal-oral– Fomites

• Nomenclature- GxP[x]– VP7 (G) = Glycoprotein– VP4 (P) = Protease-sensitive– VP6 (I) = Inner capsid– NSP4 (E) = Enterotoxin

RVHRVGRVFRVERVD

RVCRVBRVA

RVA-RVH

Objective was to investigate associations among age, RV group, and regions within the US

Percentages of RV infections differ by state

Percentages of RV co-infections differ by state

Prevalence over time

Mixed-effects regression models

• RV status was more similar within states than between states or within regions

• RV detection was similar within-regions than between regions• Swine densities • Swine production systems and• Swine management practices (all-in all-out vs. continuous

flow• Weather – wind, humidity, and temperature

RV immunity and epitope characterization

Franco et al. 2006

VP7 (G)VP4 (P)-cleaved into VP8* & VP5*

Porcine RV prevention

• Prevention– Swine rotavirus A vaccine - Prosystem

RCE

– Feedback

– Subunit vaccines

Neutralizing epitopes

P[7] vs OSU & A2

P[13] vs OSU & A2P[13] vs Gottfried

More research is needed

• Sequencing allows us to investigate genetic diversity and predict differences in the neutralizing epitopes.

• Vaccine rates for RVA are unknown.

• We lack immunological assay to understand RV immunity.– Is the traditional G and P cross protective

immunity still accurate?

• What about rotavirus C? – Different pathogen, different neutralizing

epitopes, and could stimulate the immune system differently

Acknowledgements

• It takes a team – Nitipong Homwong– Omer Sheikh– Andres Diaz– Matt Jarvis– Todd Knutson– Max Ciarlet– Stephanie Rossow

• Funding Sources– Ministry of Science and

Technology of the Royal Thai Government

– Higher Education Commission of Pakistan

– Marthaler’s Start up funds

Swine veterinarians for submitting the enteric samples and for requesting the RVA sequencing. THANK YOU!

Meet the research team and learn more about other research projects

Marthalerlab.org