Molecular detection of Sarcocystis neurona in cerebrospinal fluid from 210 horses with suspected neurologic disease.

This research focuses on applying real-time PCR (rtPCR), a molecular detection technique, to diagnose equine protozoal myeloencephalitis (EPM) in horses. It analyzes cerebrospinal fluid (CSF) from 210 horses showing signs of this neurological disease and compares the results to immune response-based diagnostics. The study suggests that rtPCR can complement traditional EPM testing, particularly in horses that have not had previous anti-protozoal treatment.

Understanding EPM, PCR and Immunodiagnostics

• Equine protozoal myeloencephalitis (EPM) is a common neurological disease that affects horses. Symptoms are variable and can mimic many other diseases. The disease is caused by a protozoan parasite Sarcocystis neurona.
• Real-Time Polymerase Chain Reaction (rtPCR) is a laboratory technique used for detecting specific DNA sequences of microorganisms, including viruses, fungi, and parasites. It can precisely identify the presence of even a tiny amount of specific DNA in a sample, in this case the DNA of S. neurona in horse cerebrospinal fluid.
• Immunodiagnostics is a type of testing that looks for an immune response to a specific pathogen. In this research, it entails analyzing samples for antibodies against S. neurona.

Research Process and Findings

• The study analyzed 210 CSF samples of horses showing signs of neurological disease.
• They used both rtPCR and immunodiagnostics techniques for detection of S. neurona to compare their effectiveness.
• Of the tested samples, 25 horses were found to be rtPCR-positive. That is, S. neurona DNA was detected in their CSF. Another 30 samples demonstrated the presence of antibodies against S. neurona, indicating an immune response to S. neurona. Additionally, 13 horses tested positive using both methods.
• The researchers also documented factors like origin of the horse, time of the year, clinical signs, and history of treatment.

Key Takeaways

• One key finding was that horses previously treated for EPM were more likely to test positive only using immunodiagnostics, while horses without treatment were more likely to test positive through rtPCR.
• This significant outcome supports the complementary role of rtPCR in the diagnosis of EPM. Notably, rtPCR was more effective in cases where there was no history of anti-protozoal treatment.
• As such, incorporating rtPCR as diagnostic tool not only enhances the precision of diagnosis, but also extends the scope of diagnostic processes, especially for horses that have not received any prior treatment for EPM.