Genotyping of isolates of Taylorella equigenitalis from thoroughbred brood mares in Japan.

The research involves genotyping of Taylorella equigenitalis, a bacterium causing contagious equine metritis (a sexually transmitted disease in horses), isolated from thoroughbred brood mares in Japan from 1980-1993. The study suggests that the isolates over this 10 year period have a common genotype, indicating a shared origin.

Background of the Research

• The research focuses on Taylorella equigenitalis, a bacterium responsible for a sexually transmitted disease in horses, known as contagious equine metritis.
• The bacteria were isolated from thoroughbred brood mares in Japan over the breeding seasons from 1980 to 1993, plus five strains that were previously isolated in Japan.

Research Methodology

• The team conducted genotyping of the bacterial DNA. This involves characterising the genetic makeup of the organism, with an aim to identify any specific ‘markers’ or characteristics.
• Strains of T. equigenitalis were subjected to restriction digestion and crossed-field gel electrophoresis.
  In restriction digestion, specific enzymes (in this case, ApaI and NotI) are used to cut DNA into smaller fragments while crossed-field electrophoresis is a technique that helps in visualising the DNA fragments.

Results and Interpretation

• Upon analysis, researchers discovered that the genomic DNA profiles of the different strains were essentially identical; all shared a common genotype, termed ‘genotype J’.
• The similarities in the genetic profiles of these bacteria suggest that they likely originated from a common source over the more than ten-year isolation period in Japan.
• This genotyping process can strengthen measures to control the spread of the disease since it suggests that the pathogen’s spread could be traced back to this common source.