Identification of equine herpesviruses 1 and 4 by polymerase chain reaction.

The research worked on creating specific, fast and sensitive diagnostic tests using polymerase chain reaction (PCR) for diagnosing diseases caused by equine herpesvirus 1 and 4 in horses. These new PCR-based diagnostic tools were able to accurately detect the viruses in samples from horses and aborting fetuses.

Methodology

• PCR tests were developed based on the nucleotide sequences that encode glycoprotein H (gH) of EHV1 and gB of EHV4. These are proteins found in the virus that can distinguish them from other viruses.
• The researchers designed sets of primers, short pieces of RNA or DNA that can specifically bind to these sequences, for each virus.
• The characteristics of the PCR conditions, such as temperature and timing, were defined to ensure accurate and efficient amplification.
• The specificity and sensitivity of the tests were determined, meaning how well the tests could correctly identify the viruses and the minimum amount of virus needed for detection.
• These tests were applied to swabs from horses with acute febrile respiratory disease and tissue samples taken from aborted equine fetuses, conditions commonly associated with these viruses.

Results

• The PCRs were successful in only amplifying the intended virus, demonstrating their specificity.
• These tests were capable of detecting very small amounts of the virus, showing their high sensitivity.
• A second, more refined PCR (seminested) was able to detect even fewer molecules than the first round, thereby increasing the sensitivity of the test.
• There was a strong correlation between the results of the PCRs and conventional virus isolation methods.
• All samples that were positive for the virus based on traditional virus isolation methods were also positive according to the PCR tests.

Conclusion

• The development of the new PCR diagnostics is significant as it allows for the reliable and rapid detection of EHV1 and EHV4.
• This adds an invaluable tool for the veterinary field, allowing for quicker and more accurate diagnosis of diseases caused by these viruses and leading to prompter treatments.
• Additionally, these tools can aid in research studies on these viruses, possibly leading to a better understanding of their biology and the diseases they cause. This could potentially pave the way for the development of preventative measures such as vaccines.