Laboratory diagnosis of Clostridium difficile-associated diarrhoea: a plea for culture

J Med Microbiol. 2005 Feb;54(Pt 2):187-191. doi: 10.1099/jmm.0.45844-0.


A routine protocol for diagnosing Clostridium difficile-associated diarrhoea (CDAD) based on both faecal-cytotoxin detection and toxigenic culture was adopted by the microbiology laboratory of the St Luc-UCL University Hospital in Brussels in 1997. A toxigenic culture is a faecal culture followed, in the case of positivity, by a direct immunoassay on colonies to detect toxin A production. The results obtained over the past 7 years in the hospital are reviewed here. A total of 10,552 diarrhoeal stools from 7042 patients were analysed, of which 9494 were negative for all tests. A total of 1058 samples (10 %) from 794 patients were culture-positive, of which 460 (4.4 %) were positive for a faecal cytotoxin. The remaining 598 cultures were tested for toxin A on colonies; 355 of them were positive, which is 3.4 % of the total, and the remaining 243 (2.3 %) were negative. The positivity of the faecal-cytotoxin assay was statistically linked to the number of colonies observed on the culture plate. In conclusion, over a 7 year period, toxigenic culture allowed the diagnosis of 355 cases of CDAD that would have been missed by a protocol using a faecal-cytotoxin assay alone. In terms of both patient care, prevention of environmental contamination and prevention of risk of a hospital outbreak, it is proposed that these results justify the recommendation to perform both faecal-toxin assay and culture in routine medical practice.

Publication types

  • Review

MeSH terms

  • Bacteriological Techniques
  • Clinical Laboratory Techniques
  • Clostridium Infections / diagnosis*
  • Clostridium difficile / isolation & purification*
  • Diarrhea / diagnosis
  • Diarrhea / epidemiology
  • Diarrhea / microbiology*
  • Enterocolitis, Pseudomembranous / diagnosis*
  • Enterocolitis, Pseudomembranous / immunology
  • Enterotoxins / analysis*
  • Enterotoxins / immunology
  • Feces / microbiology*
  • Humans


  • Enterotoxins