Streptococcus equi subspecies equi from strangles suspected equines: molecular detection, antibiogram profiles and risk factors.

This research focuses on strangles, an infectious disease in horses caused by a bacterium, Streptococcus equi subspecies equi. The study investigates the genetic factors linked to the spread of the disease, antibiotic resistance profiles, and risk factors for infection in areas of central Gondar, Ethiopia.

Research Approach and Methodology

• The research was conducted as a cross-sectional study, a type of observational study that analyzes data from a population at a specific point in time. Data collection took place from July to December 2022.
• It was carried out in five districts located in the central Gondar zone of Ethiopia.
• The researchers sampled 160 equines suspected of suffering from strangles. From these, they isolated Streptococcus equi and detected the presence of the SeM gene – a gene associated with the disease.
• Detection of the SeM gene involved the use of polymerase chain reaction (PCR), a technique used in molecular biology to amplify a single or few copies of a piece of DNA across several orders of magnitude.
• They also carried out an antimicrobial susceptibility test using the Kirby-Bauer disc diffusion method, to study the resistance of the bacteria to various antibiotics. This method involves placing antibiotic-infused discs on a plate where bacteria are growing and seeing if the bacteria can grow around the discs.
• Lastly, they used a binary logistic regression model to test the statistical significance of the data. This model is used when the dependent variable is a binary variable, i.e., it can take only two possible outcomes – presence or absence of the disease in this case.

Key Findings

• Out of the 160 samples, S. equi was found in 51 (31.87%), and the SeM gene was detected in 16 of these 51 samples (31.37%).
• The antimicrobial susceptibility test revealed high resistance to antibiotics such as tetracycline, erythromycin, and vancomycin among the 16 isolates.
• The study also identified various risk factors associated with the spread of strangles. Factors such as sharing feed containers, drinking from the same water troughs, and sharing overnight spaces were found to contribute significantly to the likelihood of acquiring the disease.

Implications and Conclusion

• The study concludes that the regions involved in the study attributed to the spread of strangles, likely due to poor sanitary management of the equines, such as sharing feed containers and water troughs.
• This signifies a need for regular cleaning of these containers to prevent contamination and the spread of the disease.
• The high rates of antibiotic resistance imply the requirement for stricter antibiotic use guidelines and exploration of alternative treatments.
• Overall, the findings of this study may be used to develop effective control measures and improve overall equine health.