Identification of mixed equine rhinitis B virus infections leading to further insight on the relationship between genotype, serotype and acid stability phenotype.

The research article discusses the identification of mixed infections of equine rhinitis B virus (ERBV) in horses, providing further insights into the relation between virus genotype, serotype and acid stability phenotype.

About Equine Rhinitis B Virus (ERBV)

• The ERBV is the only species in the genus Erbovirus, which falls under the family of Picornaviridae.
• This virus exists in three different serotypes and is associated with respiratory diseases in horses.
• The members of this species demonstrate varying stability at acid pH levels.

Objective of the Research

• The researchers aimed to find a correlation between the ERBV’s genotype, serotype, and acid-stability phenotype.
• The research was also intended to identify capsid regions associated with acid stability.

Research Methodology

• The researchers treated two types of viruses at pH 3.3 in a serial manner to isolate acid-stable mutants.
• They then identified an acid-stable mutant of the prototype acid-labile serotype 1 virus, which showed a single amino acid change in the VP1’s C-terminus.

Findings of the Research

• The researchers discovered multiple ERBV serotype infection, including acid-labile serotype 1 and acid-stable serotype 3. Dual infections were identified in original samples from the infected horse.
• They also examined a collection of isolates, which represented a range of genotypes, acid-stability phenotypes, and serotypes, using serotype-specific rat antisera.
• The research contradicts previous reports suggesting that viruses earlier classified as acid-stable serotype 1 are actually serotype 3.
• The findings also demonstrate a clear correlation between the serotype, genotype, and acid-stability phenotype of ERBVs.
• Moreover, the study shows that ERBV capsids, similar to closely related viruses, dissociate into pentamers under acidic conditions falling below their stability threshold.