Polymerase chain reaction-restriction fragment length polymorphism analysis of the SzP gene of Streptococcus zooepidemicus isolated from the respiratory tract of horses.

The research article focused on using a newly developed method, PCR-RFLP, for molecular typing of the bacteria Streptococcus zooepidemicus strains. They used this method to analyze various isolates from the respiratory tract of Thoroughbreds and found it to be effective.

Objective of the Study

• The main purpose of the study was to develop and implement the use of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) for molecular typing of Streptococcus zooepidemicus strains.
• The research also aimed to use this new typing method to analyze a multitude of isolates from Thoroughbred horses’ respiratory tracts.

Research Methodology

• Ten strains of S zooepidemicus, 65 isolates from the respiratory tracts of nine yearlings following long-distance transport, and 89 isolates from 20 pneumonia-afflicted foals’ tracheal aspirates were used in this study.
• The researchers detected differences in the SzP protein using Western immunoblot analysis.
• PCR-RFLP analysis was used to obtain genotypes with primer sets from the SzP gene, followed by restriction endonuclease digestion of the amplicons.

Results of the Study

• Unique genotypic patterns were identified using a primer set designed from both ends of the structural gene and the restriction endonuclease DdeI.
• From the yearlings’ lymphoid tissue within the pharyngeal recess or pharyngeal tonsil, 45 isolates yielded ten SzP genotypes and phenotypes.
• The isolates originating from each yearling’s trachea were of a singular genotype and were also present amongst the isolates from the same horse’s pharyngeal tonsil.
• The isolates collected from the foals’ tracheal aspirates belonged to fourteen different genotypes.

Conclusion

• PCR-RFLP was shown to be effective for molecular typing of S zooepidemicus strains, specifically for studying respiratory tract diseases in horses.
• According to the PCR-RFLP analysis results, a solitary strain of S zooepidemicus had a high migration rate from the horse’s pharyngeal tonsil to the trachea when the horse underwent long-distance transport.