Optimized Surveillance Testing for Toxigenic Clostridioides difficile to Scale Prevention Programs Across Clinical...

Area of Science:

• Clinical Microbiology
• Infectious Diseases
• Healthcare Epidemiology

Background:

• Clostridioides difficile (C. difficile) infections are a leading cause of healthcare-associated infections (HAIs).
• Current surveillance strategies for toxigenic C. difficile are not scalable for clinical microbiology laboratories.
• Effective prevention programs require scalable methods to identify patients colonized with toxigenic C. difficile strains.

Purpose of the Study:

• To develop and validate a scalable surveillance strategy for detecting toxigenic C. difficile colonization.
• To utilize existing rectal swabs collected for vancomycin-resistant Enterococci (VRE) surveillance.
• To enhance C. difficile prevention programs through improved patient identification.

Main Methods:

• Developed a two-step method involving ex vivo amplification in Cdiff Banana Broth (BB) followed by confirmatory testing.
• Optimized confirmatory testing using C. difficile QuickCheck and Cepheid's Xpert C. difficile/Epi assay.
• Evaluated the method's sensitivity, specificity, and performance on VRE surveillance swabs from diverse healthcare settings.

Main Results:

• The BB with confirmation method demonstrated 92% specificity and 100% sensitivity, detecting toxigenic C. difficile at <5 CFU/swab.
• Prospective testing of 797 VRE swabs revealed 11% positivity for toxigenic C. difficile and 4% for non-toxigenic strains.
• The method allowed for C. difficile detection within 24-48 hours and preserved viability for 7 months with glycerol addition.

Conclusions:

• BB with confirmation offers a highly sensitive and scalable approach for detecting toxigenic C. difficile colonization.
• Leveraging VRE surveillance swabs eliminates the need for additional patient samples, simplifying deployment.
• This strategy can be implemented across healthcare settings to support C. difficile infection prevention initiatives.