Evidence for two serotype G3 subtypes among equine rotaviruses

Area of Science:

• Veterinary Virology
• Molecular Epidemiology
• Immunology

Background:

• Equine rotaviruses are significant pathogens in foals.
• Accurate characterization of rotavirus strains is crucial for understanding disease spread and developing control strategies.
• Limited data exists on the diversity of cultivable equine rotavirus strains in different geographical regions.

Purpose of the Study:

• To characterize ten cultivable equine rotavirus isolates from North America, Britain, and Ireland.
• To determine the serotypes and subgroups of these isolates using various immunological and molecular methods.
• To identify potential subtypes within serotype G3 strains.

Main Methods:

• Cross-neutralization assays with standard rotavirus strains.
• Neutralization assays using a panel of monoclonal antibodies (MAbs).
• Hybridization assays with a simian rotavirus (SA-11) VP7 gene probe.
• Enzyme-linked immunosorbent assays (ELISAs) with rotavirus subgrouping and serotyping MAbs.

Main Results:

• Six isolates were confirmed as serotype G3, one as G5, and three were unrelated to serotypes G1-G10.
• Serotype G3 strains were divisible into two subtypes (G3A and G3B) based on neutralization and MAb reactions.
• Isolates showed varied reactions with subgrouping MAbs, with two not binding either MAb, six binding both, and two binding only subgroup I MAb.

Conclusions:

• The characterization revealed significant diversity among equine rotavirus isolates.
• Subtyping of G3 strains provides finer epidemiological resolution.
• The employed assays are valuable tools for future equine rotavirus investigations and surveillance.