Comparison of five basal compositions of selective chocolate agar media for isolation of Taylorella equigenitalis.

The study is on the evaluation of different agar media compositions for effectively isolating Taylorella equigenitalis, the bacterium responsible for a contagious horse disease called equine metritis. The research suggests that the current media for bacterial culture can perform better with adjustments in the base ingredients and supplements.

Context and Objective

• This research article focuses on improving methods for isolating Taylorella equigenitalis (T. equigenitalis), the microorganism responsible for equine metritis, a debilitating reproductive disease in horses.
• The World Organisation for Animal Health Terrestrial Manual recommends culture method as the most valid method for isolating and identifying this microorganism.
• The existing culture media, since their development in the 1980s, have shown limited performance due to the complex nature of T. equigenitalis and the presence of other bacterial communities within the equine genital tract.

Methods and Materials

• In this research, the growth rates of T. equigenitalis strains were compared with non-T. equigenitalis strains in a selective medium known as Timoney’s medium.
• This medium was formulated with five different basal agars – Columbia, Eugon, Blood, Mueller-Hinton, and Tryptose Blood – provided by different suppliers.
• The researchers also examined the effect of adding glucose and/or a supplement called Vitox to the media.

Findings

• The study has found that the performance of T. equigenitalis selective medium could be improved by replacing the Eugon or Columbia agars with Blood, Mueller-Hinton or Tryptose Blood agars.
• However, the choice of basal agar and its supplier must be validated with several T. equigenitalis strains, as results may vary accordingly.
• Fascinatingly, the study reaffirmed prior knowledge that supplementing selective media is beneficial, particularly with a mix of amino acids, nucleotides, and organic, mineral and vitamin compounds – represented here by Vitox supplementation.

Impact

• This study makes a significant contribution to perfecting the current culture method by suggesting alternatives for the existing medium’s components.
• These variations in the selective medium could assist in more accurate detection and isolation of T.equigenitalis, aiding the broader aspects of treating and controlling equine metritis.