Metabolite changes in equine amniotic fluid associated with experimentally induced ascending placentitis
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Published on: August 2, 2017
Sophia P Marchio1, Hossam El-Sheikh Ali2, Cory Klemashevich3
1College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA.
Background:
Equine ascending placentitis is a major cause of late-term pregnancy loss and stillbirth. However, early diagnosis remains limited, and its effect on amniotic fluid metabolite composition is poorly understood.
Aims/Objectives:
Characterize alterations in the amniotic fluid metabolome of mares with experimentally induced ascending placentitis.
Methods:
This was a controlled experimental study. At 280 days of gestation, six pony mares received an intracervical inoculation of Streptococcus equi subspecies zooepidemicus (placentitis group), and five mares were left untreated (control group). Placentitis mares developed signs of placental inflammation and were euthanized 8 days post-inoculation. Control mares were euthanized at corresponding gestational ages. Amniotic fluid was collected immediately after euthanasia and analyzed by untargeted liquid chromatography-mass spectrometry. Metabolites were annotated against a spectral library, with a match score above 60% considered a confident identification.
Results:
Eighteen metabolites differed between groups (P ≤ 0.05). Two were confidently identified. L-threonine was lower in placentitis mares than in control mares. L-isoleucine was higher in placentitis mares than in control mares.
Conclusion:
In mares with ascending placentitis induced at 280 days of gestation, the amniotic fluid metabolome was altered, including decreased L-threonine and increased L-isoleucine.
