Principal Investigator: Jessica Allegretti, Lynn Bry
Patients with inflammatory bowel disease (IBD) are at greater risk of developing Clostridioides difficile infections, a bacterium that infects the gut, and are more likely to experience severe outcomes from infection than patients without IBD. Validated methods of detecting toxin-producing C. difficile in patients with IBD are lacking, so we developed a screening method using colonoscopy washes from these patients. The washes were used for experimentation as is (unmanipulated) and simultaneously enhanced for C. difficile growth in a nutrient-rich environment for the bacterium. Growth that looked like C. difficile was identified using a laser-based system that analyzes molecules in the bacterium. A gene-amplifying technique was used to determine if identified C. difficile strains contained a gene that would allow production of a harmful toxin. C. difficile was detected in 15% of washes in the nutrient-rich environment compared to 10% of unmanipulated washes. 93.3% of strains identified in the washes in the nutrient-rich environment were toxin-producing compared to 60% in the unmanipulated washes. Enhanced testing methods can better identify the presence of C. difficile in patients. More effective C. difficile identification, particularly toxin-producing C. difficile, can change the course of treatment in IBD patients.
Patients with inflammatory bowel disease (IBD) are at greater risk of developing Clostridioides difficile infections and are more likely to experience severe outcomes from infection than patients without IBD. Validated methods of detecting toxigenic C. difficile carriage in patients with IBD are lacking, so we developed a C. difficile screening method for these patients using 100 colonoscopy washes collected during a colonoscopy. Selective enrichment was evaluated with plating of washes to CHROMID® C. difficile agar. This method evaluated growth in taurocholate and antibiotic-enhanced Brain Heart Infusion (BHI) broth with plating to CHROMID® C. difficile agar. C. difficile was identified by colony morphology and speciated via mass spectrometry or RapID™ ANA. Toxin carriage in C. difficile strains was determined by PCR. Taurocholate and antibiotic-enhanced BHI enrichment showed greatest sensitivity of detection at 15% followed by direct culture of washes at 10%. Toxin carriage was found in 60% of C. difficile strains identified via direct culture and 93.3% of strains identified via enhanced BHI enrichment. Increased qualitative testing can identify the presence of C. difficile in patients that initial processing may miss. More effective C. difficile identification, particularly toxigenic C. difficile, can change the course of treatment in IBD patients.
If the PDF viewer does not load initially, please try refreshing the page.