Antibacterial activity of mare uterine fluid.

This research studied the antibacterial properties of uterine fluid in mares. It found that the fluid had increased antibacterial activity during certain stages of the mare’s estrous cycle.

Process of the Research

• The researchers collected uterine flushings from mares at various stages of the estrous cycle, specifically on Day 3 of estrus, Day 8 postovulation and Day 15 postovulation.
• The collected uterine proteins were concentrated and studied for any antibacterial properties and activities against neutrophils, a type of immune cell which responds to infection.
• The researchers also collected and analyzed serum (a component of blood) at the same timepoints, examining it in the same way as the uterine protein.

Results of the Investigation

• The research findings showed that both uterine protein and serum taken on Day 3 of estrus and Day 8 postovulation stimulated increased neutrophil migration, implying a higher immune response and therefore potential antibacterial activity.
• Analysing the antibacterial activity involved measuring the growth of a specific bacteria (S. zooepidemicus) when incubated with either uterine flushing or serum. The result revealed that serum, regardless of the stage of the estrous cycle, did not hinder bacterial growth.
• Interestingly, after a 4-hour incubation, bacterial growth in estrous (Day 3) serum was significantly higher compared to serum taken on both Day 8 and 15 postovulation.
• On the other hand, uterine flushings collected on Day 8 postovulation significantly decreased the ability of bacteria to form colonies, indicating an apparent antibacterial activity.
• In addition, an examination of the effects of heat on the antibacterial activity of the flushings found that heating them at 56 degrees C for 30 minutes did not abolish the antimicrobial activity, but heating at 80 degrees C for 30 minutes removed this activity.
• The final conclusion of this research was that the detected antibacterial activity is not likely caused by agglutinating antibody, a type of antibody that causes microorganisms to clump together hence aiding their elimination by the immune system.