Clostridium difficile associated with acute colitis in mature horses treated with antibiotics.

The research studied the association of a bacterium called Clostridium difficile with acute colitis in mature horses that were treated with antibiotics for non-diarrhea related disorders. The study found that the bacterium was present in 40% of such cases and was especially prevalent in hospitalised horses, suggesting that the bacterium might be the underlying cause of the inflammatory condition.

Study Design and Populations

• The study involved the examination of faecal samples from different sets of horses to understand the presence and correlation of Clostridium difficile in various conditions.
• The first group consisted of 25 mature horses suffering from acute colitis who were primarily treated with antibiotics for disorders other than diarrhoea.
• In contrast, the control groups included 140 horses without any signs of intestinal disorders, 21 non-diarrhoeic horses treated with antibiotics, and 22 horses with colitis that were not treated with antibiotics.

Results and Findings

• 40% of the mature horses treated with antibiotics for non-diarrhea related disorders tested positive for Clostridium difficile or its cytotoxin.
• None of the control groups, i.e., healthy horses, horses treated with antibiotics unrelated to diarrhoea, or colitis-stricken horses not treated with antibiotics, showed the presence of this bacterium.
• Among the 10 horses that tested positive for the bacterium or its cytotoxin, four had both and the rest only had one of the two.

Interpretations and Significance

• This high prevalence of the bacterium in a specific category of horses reinforced previous reports about such an association, strongly suggesting that Clostridium difficile might be the cause of acute colitis in mature horses treated with antibiotics for non-diarrhea related disorders.
• Eight out of the ten horses that tested positive had been, or were currently, hospitalised which implies that the infection could be contracted in hospital settings (nosocomial infection).
• All horses that tested positive for the bacterium were treated with a type of antibiotics known as beta-lactam, further emphasising the potential role antibiotics might play in the occurrence of this bacterium.