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Updated: Feb 14, 2026

Culturing and Maintaining Clostridium difficile in an Anaerobic Environment
Published on: September 14, 2013
Evaluation of 4 molecular assays as part of a 2-step algorithm for the detection of Clostridium difficile in stool
Adam J Caulfield1, Catherine M Bolster LaSalle2, Yu-Hui H Chang3
1Spectrum Health Regional Laboratory, Grand Rapids, Michigan.
Abstract:
Detection of Clostridium difficile infection is important for clinical laboratories, owing to debilitating disease, severe outcomes, patient awareness, and public reporting of hospital data. This study evaluated the performance of 4 nucleic acid amplification test (NAAT) assays as part of a 2-step algorithm that involves reflexive NAAT following enzyme immunoassay (EIA) testing that is indeterminate for glutamate dehydrogenase (GDH) antigen and toxin A/B (GDH+/toxin- or GDH-/toxin+). A total of 500 stool specimens from consecutive patients were tested by each of the 5 methods and also evaluated as part of a 2-step algorithm. A specimen was considered positive for presence of C. difficile if it tested positive by 3 of 4 molecular methods or toxigenic culture. The sensitivity and specificity of the GDH-EIA method were each 93%. The toxin EIA had only 48% sensitivity, but it had 99% specificity. Sensitivity and specificity of 2-step algorithmic testing ranged from 88% to 93% and 99% to 100%, respectively, offering similar performance to stand-alone NAAT testing.
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