Detection of Clostridium difficile Toxins in Stools and Presence of the Bacteria in Tissues in a Pediatric Population
J Guarner, J Bhatnagar, T Jones, E Schemankewitz, SR Zaki. Emory University, Atlanta, GA; Centers for Disease Control and Prevention, Atlanta, GA; Children's Healthcare of Atlanta, Atlanta, GA
Background: Pseudomembranous colitis has been associated with Clostridium difficile overgrowth after use of broad-spectrum antibiotics. Even though C. difficile toxin is frequently found in the stool of children, pseudomembranous colitis is rare, suggesting that bacteria are colonizing the gut without producing pathology. The objective of this study was to correlate the presence of C. difficile toxin in stool and presence of gastrointestinal pathology with detection of C. difficile in pediatric tissue samples.
Design: We performed a retrospective chart review of 12 patients who had intestinal tissue obtained around the time stools were positive for C. difficile toxins using a kit that employs a monoclonal anti-toxin A antibody and a polyclonal anti-toxin B antibody. Paraffin embedded tissues were studied by an immunohistochemical assay (IHC) using a polyclonal anti-C. difficile antibody and by a PCR assay specific for C. difficile toxin B gene.
Results: The median age was 8 years (range 4 weeks to 17 years) and 5 were female. The median amount of time between the positive C. difficile toxin in stool and obtaining the tissue was 3 days (range same day to 8 weeks). The reason antibiotics were prescribed included diarrhea (4 children), fever (3), abdominal pain (2), vomiting (1), cellulitis (1), and sepsis (1). Nine patients underwent endoscopy which showed normal mucosa (2), erythema and friability (2), erosions (2), increased mucous production (1), and pseudomembranes (1). Two children underwent laparotomies for either obstruction or resection of necrotic bowel. One child died and the intestine showed abundant pseudomembranes. Mild inflammation was observed in 7 samples, necrosis in 2, granulomatous inflammation in 1, moderate colitis in 1 and pseudomembranous colitis in 1. IHC demonstrated non-specific staining of bacilli and cocci in the lumen. PCR for the toxin B gene was negative in all cases.
Conclusions: Detection of C. difficile toxin in stool and non-specific staining of bacteria using IHC may relate to the use of polyclonal antibodies. No correlation was observed between immuno assays and PCR in these children. Development of tests that are specific for C. difficile is necessary to understand the pathogenic mechanism of the bacteria and its toxins.
Monday, March 9, 2009 1:00 PM
Poster Session II # 190, Monday Afternoon