Comparison of clinical, microbiologic, and clinicopathologic findings in horses positive and negative for Clostridium difficile infection.

This research investigates the differences in clinical, microbiological, and clinicopathological characteristics among horses infected with Clostridium difficile, particularly focusing on those carrying the toxin A, versus horses not infected with this bacterium. It finds horses with toxin A present have more serious symptoms, including a higher mortality rate.

Methodology of the Study

• The study is a cross-sectional analysis conducted on 292 horses and foals that were reported to have diarrhea.
• Fecal samples from these horses were cultured for microbes and tested for the presence of the Clostridium difficile antigen named glutamate dehydrogenase. They were also examined for the presence of toxin A using commercial ELISA (Enzyme-Linked Immunosorbent Assay).

Results and Findings

• The study revealed that horses showing the presence of toxin A in their feces exhibited a higher band neutrophil count, increased rectal temperature, lengthier pre-diarrhea hospitalization period, and total hospitalization duration when compared with horses not infected with C. difficile.
• Out of the horses with toxin A in their feces, 97% had received antimicrobial treatment before the onset of diarrhea.
• The fatality rate was significantly higher in horses testing positive for toxin A versus horses that tested negative.
• The ELISA’s sensitivity and specificity in detecting the C. difficile antigen were high when compared with direct plating microbial culture results (93% and 88% respectively) but performed at a lower level when compared with broth enrichment microbial culture results (66% and 93% respectively).

Conclusion

• The findings of the study suggest that horses testing positive for toxin A have more severe clinical conditions than horses testing negative for toxin A or horses showing diarrhea symptoms but not infected with C. difficile.

Based on these results, it seems that the presence of toxin A in C. difficile infection substantially aggravates the clinical conditions in horses, leading to a higher mortality. The ELISA can be used effectively to detect C. difficile antigens, but its effectiveness may vary depending on the type of microbial culture methods used. This research can assist in better understanding the impact of C. difficile infection and improving the clinical treatment for horses suffering from this bacterial infection.