Archival PCR-based diagnosis of Clostridium difficile in piglets

Clostridium difficile is a Gram-positive, spore-forming, anaerobic bacterium, and is commensal in the alimentary tract of animals. It is an important cause of antibiotic-associated diarrhoea and pseudomembranous colitis in human beings (Riley and others 1994), enterocolitis in foals (Jones 1989), nosocomial diarrhoea and typhlocolitis in adult horses (Madwell and others 1995), and typhlitis and colitis in adult hamsters (Chang and Rohwer 1991). Moreover, C difficile has been reported to be an aetiological agent of neonatal swine enteritis in the USA (Waters and others 1998, Songer and others 2000). The organism produces at least two toxins: toxin A and toxin B (Lyerly and others 1988, Giannasca and others 1999). Toxin A is both a cytotoxin and an enterotoxin capable of inducing fluid accumulation in ligated intestinal loops, while toxin B is a more potent cytotoxin (Giannasca and others 1999). These toxins are thought to play a major role in the diarrhoea and colitis caused by C difficile because passively administered anti-toxin antibodies against toxin A and toxin B protected animals from C difficile infection (Giannasca and others 1999). This short communication describes the archival-based diagnosis of C difficile associated with an outbreak of diarrhoea in Korean piglets. Archived, formalin-fixed, paraffin wax-embedded tissues from eight piglets from different herds were selected on the basis of the animals' clinical signs and histopathology. Pathogenic Escherichia coli, porcine epidemic diarrhoea virus, transmissible gastroenteritis virus and rotavirus were not detected in any of the cases. For each pig, a 10 pm wide section of large intestine was prepared from tissue blocks, and