Infectious Endometritis in Mares: Microbiological Findings in Field Samples.

This research investigates the cause of endometritis, an inflammation of the inner lining of the uterus, in mares, focusing on the bacteria involved. It emphasizes the use of uterine lavage and bacteriological procedures in diagnosing and identifying the specific microorganisms contributing to this condition.

Introduction and Aims

• The study addresses Endometritis in mares, a leading cause of infertility and lesser fertility. It’s perceived that early detection of the responsible pathogens is essential to start timely and correct treatments, thereby increasing fertility chance and minimizing bacterial resistance.
• The retrospective study spanned from 2014 – 2018, with 394 collected samples (uterine swabs and lavages) from mares, whether they have a clinical history of endometritis or not.

Methods and Findings

• A bacteriological procedure was engaged that involved subculturing samples from an enrichment in Brain Heart Infusion Broth, which were initially negative after direct smearing.
• The examination resulted in a total of 386 microorganisms extracted from 230 positive samples. This represents a 58% positivity rate.
• 33% of the total samples showed at least one microorganism after direct smearing, while an additional 25% showed one post-enrichment.
• The analysis of the direct smearing and enrichment results reveals a significant difference in the frequency of positive uterine lavages (80%) compared to swabs (53%).

Microbial Presence

• The most commonly occurring bacteria in the samples were α-haemolytic Streptococcus and Escherichia coli (each with 27%), β-haemolytic Streptococcus (26.1%), and Staphylococcus spp. (19.1%).
• In monoculture situations, the often-seen microorganisms consisted of α-haemolytic Streptococcus (13%), Staphylococcus spp. (12.2%), β-haemolytic Streptococcus (11.4%), and Escherichia coli (9.8%).
• Regarding samples with a pure bacterial presence, Gram-negative bacteria grew preferentially right after direct smearing, while Gram-positive bacteria thrived after enrichment.

Conclusion

• The findings from this research demonstrate that using a high volume of fluid for uterine lavage significantly enhances the sensitivity of the bacteriological examination.
• The study also emphasizes the importance of the enrichment phase in routine bacteriological laboratory procedures since it increases the isolation rate.