The bacteriological culture of equine uterine contents, in-vitro sensitivity of organisms isolated and interpretation.

This research conducted over four years studied bacterial cultures from equine uterine swabs, investigating prevalence and sensitivity of isolated organisms to antibiotics. Their findings suggest that uterine cytology with Gram staining can provide a rapid preliminary diagnosis and guide appropriate antibiotic selection.

Research Methodology

• The study was conducted over four years, during which uterine swab samples were collected from 1539 mares, with pathogenic bacteria isolated from 498 of these samples.
• Five veterinary clinicians used two different techniques for swab collection.
• The researchers took careful measures to minimize bacterial contamination during swabbing. This included thorough cleaning of the external genitalia and perineal area, along with careful handling of the culture specimen.

Results and Findings

• A total of 19 different pathogenic bacterial species were identified. The most prevalent organisms isolated were beta-haemolytic streptococcus (39% of cases), Escherichia coli (27%), and Klebsiella pneumoniae (7%).
• The researchers found good correlation between their microbiological findings and clinical findings when the number of organisms isolated and endometrial cytology were taken into account. This suggests that the count and type of bacteria present could offer predictive value for disease state and severity.
• Use of a bacterial transport medium in conjunction with advanced culture methods provided a more accurate depiction of the uterine microflora compared to previous techniques.

Antibiotic Sensitivity and Treatment

• The streptococci isolated showed uniform sensitivity to penicillin.
• The E. coli and K. pneumoniae strains showed nearly 100% sensitivity to chloramphenicol, gentamicin, and polymyxin.
• The selection of an appropriate antibacterial agent was shown to depend on sensitivity, pharmacological action, the status of the genital tract, and cost considerations.
• The study concluded that a Gram stain of uterine cytology can be used to quickly diagnose and select an appropriate antibiotic for treatment, prior to culture results, if a sufficient number of organisms are present.