Postoperative Clostridium difficile infection with PCR ribotype 078 strain identified at necropsy in five Thoroughbred racehorses.
Authors: Niwa H, Kato H, Hobo S, Kinoshita Y, Ueno T, Katayama Y, Hariu K, Oku K, Senoh M, Kuroda T, Nakai K
Journal: The Veterinary record
Summary
# Editorial Summary Between 2008 and 2012, five Thoroughbred racehorses presented with acute, severe post-operative enterocolitis caused by *Clostridium difficile* PCR ribotype 078, a strain producing both major toxins (A and B) and the binary toxin CDT. Clinical signs emerged within two to four days of surgery and included diarrhoea or colic accompanied by haemoconcentration (packed cell volume ≥60%) and striking leucopenia (≤4000 cells/µl)—haematological parameters that distinguish *C. difficile* disease from other post-operative colic causes. Four horses died or required euthanasia following necrotising entero-typhlocolitis; one additional horse was euthanased after developing a lung abscess, suggesting systemic spread from the primary intestinal infection. The identical molecular profiles across all isolates (pulsed-field gel electrophoresis, PCR ribotyping, and *slpA* sequencing) indicate a probable nosocomial outbreak, though the four-month intervals between cases complicate epidemiological confirmation. For equine practitioners, this case series underscores that PCR 078 represents a virulent healthcare-associated pathogen in the post-operative setting, warranting careful antimicrobial stewardship, faecal diagnostics for horses with post-surgical colic, and consideration of environmental contamination control during in-patient recovery periods.
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Practical Takeaways
- •Monitor postoperative horses closely for diarrhoea and colic within the first week after surgery, particularly noting elevated packed cell volume and low white blood cell count as indicators of severe C. difficile infection
- •PCR ribotype 078 C. difficile can cause life-threatening postoperative enterocolitis in Thoroughbreds; consider early diagnostic testing and aggressive treatment when these clinical signs appear
- •Healthcare-associated transmission of C. difficile between horses is possible even with extended intervals between cases; implement enhanced biosecurity and infection control measures in surgical facilities
Key Findings
- •Five Thoroughbred racehorses developed C. difficile infection within 2-4 days after surgery, with four dying or euthanased due to severe colitis or diarrhoea
- •All cases presented with diarrhoea or colic accompanied by packed cell volume ≥60% and leucopenia ≤4000 cells/μl
- •All C. difficile isolates were toxin-A-positive, toxin-B-positive, and CDT-positive, identified as PCR ribotype 078
- •Postmortem examination revealed necrotising entero-typhlo-colitis in four horses with C. difficile recovered from intestinal contents; one horse had a lung abscess from which C. difficile was isolated