Bacteria in the healthy equine vagina during the estrous cycle.

The research article focuses on understanding the normal bacterial inhabitants of the mare’s vagina, and how these might change throughout the estrous cycle, which is crucial to understanding conditions or treatments that could disrupt its normal balance.

Objective of the Study

• The main objective of the research was to gain a comprehensive understanding of the bacterial microbiota in the mare’s vagina and observe any changes throughout the estrous cycle. This is crucial for understanding conditions or treatments that might alter the microbiota balance.

Methodology

• The researchers sampled the cranial portion of the mare’s vagina on day 0 (ovulation), day 3, day 7, and day 14 of the estrous cycle using double-guarded occluded swabs.
• Ovulation was determined via rectal palpation and ultrasonic examination. The day 0 samples were taken within ±24 hours of ovulation.
• The samples were brought to the laboratory in Amies medium within 2-3 hours and were immediately plated out on both selective and non-selective agars.

Results and Findings

• Results were presented in terms of bacterial growth, species and number of isolates. The highest bacterial growth was observed on day 3 and 7, which represents the beginning and middle of diestrus respectively.
• Two dominant bacteria, Escherichia coli and Streptococcus zooepidemicus, were identified. Escherichia coli was particularly dominant in maiden mares, in comparison to mares that had foaled.
• An increase in bacterial diversity was observed throughout the estrous cycle, with the highest diversity observed on day 14.

Conclusion

• The research concluded that there are changes in the variety and density of bacteria in the mare’s vagina throughout the normal estrous cycle, which suggests that actions or conditions influencing vaginal microbiota at different points of the estrous cycle could have different outcomes.