Diagnostic algorithm using a sensitive broth culture method for detection of Clostridium difficile toxin from stool...

Area of Science:

• Clinical Microbiology
• Infectious Diseases
• Diagnostic Assays

Background:

• Toxigenic Clostridium difficile diagnosis relies on a two-step algorithm.
• Direct cytotoxin neutralization assay (DCNA) has limited sensitivity, impacting diagnostic accuracy.
• An alternative indirect cytotoxin neutralization assay (ICNA) was investigated.

Purpose of the Study:

• To compare the diagnostic performance of ICNA versus DCNA for toxigenic C. difficile.
• To evaluate the sensitivity enhancement offered by ICNA.

Main Methods:

• ICNA involved neutralizing Clostridium difficile cytotoxin B from stool broth cultures.
• MRC-5 fibroblast cells were used in the standard cytotoxin assay.
• 923 adult stool specimens were analyzed over three months.

Main Results:

• The prevalence of toxigenic C. difficile was 13.5%.
• The overall two-step algorithm sensitivity was 88%.
• ICNA identified an additional 12% of toxigenic C. difficile cases missed by DCNA.

Conclusions:

• ICNA, utilizing broth cultures, offers increased sensitivity for detecting toxigenic C. difficile.
• The ICNA method is convenient and suitable for routine diagnostic implementation.
• Enhanced detection of toxigenic C. difficile improves diagnostic reliability.