Dual infections of equine herpesvirus 1 and equine arteritis virus in equine respiratory mucosa explants.

The research investigates the impact of dual infections of Equine Herpesvirus 1 (EHV-1) and Equine Arteritis Virus (EAV) in horses, with their results suggesting these infections don’t significantly influence each other and do not infect the same mucosal leukocytes.

Objectives and Methodology

• The researchers embarked on this study to ascertain the effect and behavior of both EHV-1 and EAV – responsible for respiratory issues and abortion in horses – when there is a dual infection in the respiratory mucosa of a horse.
• The investigation included comparing the consequences of dual infections and single infections in RK-13 cells (which are fully susceptible to these viruses) and equine upper respiratory mucosa explants.
• The process of superinfection involved infecting the cells with one virus, waiting 12 hours, and then infecting the same cells with the other virus. In co-infection, both viruses were introduced at the same time.

Findings

• Results showed that when RK-13 cells were initially infected with either EHV-1 or EAV, followed by an infection of the other virus after 12 hours, the subsequent virus infection was suppressed at 24 hours post-infection or 36 hours post-infection respectively.
• In the case of simultaneous infection, there was an increase in the numbers of EAV-infected cells while EHV-1 infected cell numbers remained the same when compared to single virus infections.
• No co-infection of EHV-1 and EAV was observed in any of the RK-13 cells, indicating that both viruses do not infect the same cells.
• In the respiratory mucosa that was exposed to EAV 12 hours prior to EHV-1, EHV-1-induced plaques (damage caused by the virus) were similar in size and number to those found in single virus infections.
• Pre-infections and co-infections of both viruses resulted in a slight reduction in the number of virus-infected leukocytes in the nasal and nasopharyngeal mucosae compared to single infections.

Conclusions

• The study concluded that dual infections of EHV-1 and EAV do not significantly affect each other’s propagation and do not co-infect the same mucosal leukocytes within the horse’s respiratory system.
• This research provides critical insights into the dynamics of these dual infections, which can help develop effective strategies to manage and treat these conditions.