Aerobic uterine isolates and antimicrobial susceptibility in mares with post-partum metritis.

This study investigates the most frequent bacterial species involved in equine post-partum metritis, their susceptibility to various antibiotics, and the prevalence of multidrug resistance. The researchers analyzed the bacterial cultures and antibiotic susceptibility test results from 45 horses and found a high prevalence of mixed infections. They offer suggestions for initial antibiotic treatments based on their findings.

Methodology

• The research is based on a retrospective analysis of uterine bacterial cultures and antimicrobial susceptibility tests (AST) from 45 mares diagnosed with metritis.
• The data collected from these tests were analysed to determine the most common types of bacteria involved in infections, as well as the bacteria’s resistance to different antibiotics.
• The team examined both single and mixed bacterial infections found in the mares.

Results

• The most common bacterial species found in cases of metritis was Escherichia coli (30.7% of cases).
• Mixed infections were more common than single infections, with 62.2% of studied mares exhibiting mixed bacterial growth.
• In mares with mixed growth, the combination of Gram-negative and Gram-positive bacteria was the most prevalent (65.5% cases).
• On the topic of antibiotic use, the study suggested that combing Gentamicin with penicillin was an effective treatment choice for 65.1% of the mares.
• Only 48.8% of mares responded effectively to trimethoprim/sulfonamide.
• The combinations of penicillin with either amikacin or enrofloxacin were found to be the most effective, working in 90.7% and 81.4% of cases respectively.
• Multi-drug resistance (MDR) was more common in the gram-negative bacteria (85.4% cases) than the gram-positive bacteria (23.5% cases).

Conclusions

• The study concluded that mixed infections were common in mares with metritis, often involving Gram-negative and Gram-positive bacteria.
• They noted the prevalence of multi-drug resistance, especially in Gram-negative bacteria.
• Based on their findings, the team concluded that sulfonamides are not an appropriate first choice of treatment for mares with metritis.
• Instead, they recommend the combination of penicillin and gentamicin as a potential initial treatment, while also suggesting amikacin or enrofloxacin as alternatives to gentamicin.