[35 leptospira isolated from the vitreous body of 32 horses with recurrent uveitis (ERU)].

This research article focuses on the isolation of leptospires, a type of bacteria, from the vitreous body of 32 horses exhibiting signs of equine recurrent uveitis (ERU) as well as detection of leptospiral antibodies. The findings suggest that leptospires play a significant role in the cause of ERU in horses.

Overview of the Study

• The study systematically collected 130 vitreous samples from 117 horses undergoing vitrectomy, a surgical procedure performed to remove the vitreous humor (the clear, gel-like substance in the eye) in 1998.
• All horses included in the study were observed to have equine recurrent uveitis (ERU), also known as periodic ophthalmia or moon blindness, a painful, chronic condition of the eye that often leads to blindness in horses. These horses were undergoing surgical treatment to manage painful outbreaks of the disease and to preserve vision.

Key Findings

• Leptospires were successfully isolated from 35 out of 130 vitreous samples, giving a prevalence rate of 26.9%.
• The isolated leptospires belonged majorly to the grippotyphosa serogroup (in 31 samples) and to the australis serogroup (in 4 samples). This fact marked the first instance of the isolation of leptospires from the eyes of a large number of horses affected by ERU.

Antibody Testing and Results

• In addition to the cultured vitreous samples, a serum sample from each horse was also tested for leptospiral antibodies using a technique known as the microscopic agglutination test (MAT).
• Leptospiral antibodies were detected in 70.7% of vitreous samples (92 out of 130) and in 82% of serum samples (96 out of 117) at a dilution greater than 1:100. The presence of leptospiral antibodies was found to be a strong indication of the body’s immune response to the leptospiral infection.

Conclusion

• The presence of both live leptospires and specific antibodies in the eyes of horses with ERU strongly indicates a local immune response against the leptospiral antigen.
• The researchers conclude that these results suggest a crucial role for leptospires in the pathogenesis of ERU in horses. The evidence presents valuable insights for the possible prevention and treatment of this recurrent, debilitating and often blinding eye condition in horses.