Detection of Pathogenic Leptospira DNA in Cervicovaginal Mucus of Mares With Reproductive Disorders in a Brazilian Herd.

Overview

• This study investigated the presence of pathogenic Leptospira bacteria DNA in the cervicovaginal mucus of mares experiencing reproductive problems in a Brazilian herd, identifying a potential link between equine genital leptospirosis (EGL) and reproductive disorders.

Background

• Leptospirosis is a zoonotic disease caused by bacteria of the genus Leptospira, affecting both animals and humans.
• Equine genital leptospirosis (EGL) is a less studied form of this disease, characterized by chronic and often silent infection localized in the genital tract of mares.
• Though EGL may influence reproductive health, it is underdiagnosed and not well understood, especially regarding its impact on reproductive efficiency.

Objectives of the Study

• To detect the presence of pathogenic Leptospira DNA in the genital tract of mares with reproductive issues using molecular diagnostic methods.
• To explore the possible association between detection of Leptospira and reproductive disorders such as abortion, stillbirth, placental alterations, and subfertility in mares.

Methodology

• Sample Collection: Cervicovaginal mucus samples were collected from 120 adult mares with recent reproductive disturbances.
• Diagnostic Technique: The study employed lipL32-PCR, a polymerase chain reaction method targeting the lipL32 gene, which is specific to pathogenic Leptospira species, to detect bacterial DNA in the samples.

Key Findings

• Leptospira DNA was detected in 30 out of 120 mares, representing 25% of the tested animals.
• Among the positive cases:
  • 23.3% had experienced abortions.
  • 3.3% had stillbirths.
  • 53.3% showed placental alterations.
  • 36.6% were subfertile (reduced fertility).
• These data indicate a high prevalence of Leptospira DNA in the genital tract of mares with reproductive problems.

Implications

• The presence of pathogenic Leptospira DNA suggests a possible contribution of EGL to reproductive inefficiency in mares.
• High detection rates highlight the importance of considering EGL in differential diagnoses for reproductive disorders in equine veterinary practice.
• Encourages the development and implementation of improved diagnostic protocols and awareness campaigns targeting equine leptospirosis.

Conclusions

• Equine genital leptospirosis may be an under-recognized cause of reproductive failure in mares.
• Targeted molecular testing such as lipL32-PCR can be a valuable tool in identifying EGL infections in mares with reproductive disturbances.
• Further studies are warranted to better understand the pathogenesis, epidemiology, and control measures for EGL to improve mare reproductive health and herd productivity.