Ann Clin Microbiol 2025;29(1):1. Performance of C. Diff Quik Chek Complete and RIDASCREEN immunoassays and lack of Ct value concordance between Allplex GI-Bacteria(I) and Xpert Clostridioides difficile assays: a diagnostic accuracy study
| QCC | RIDA | Allplex GI-Bacteria(I) assay (Toxin B) | Xpert C. difficile assay (Toxin B) | No. of specimens | ||
|---|---|---|---|---|---|---|
| GDH | Toxin A/B | GDH | Toxin A/B | |||
| Positive | Negative | Positive | Negative | Positive | Positive | 16 |
| Positive | Positive | Positive | Negative | Positive | Positive | 7 |
| Positive | Negative | Negative | Negative | Positive | Positive | 1 |
| Positive | Positive | Negative | Negative | Positive | Positive | 1 |
| Positive | Negative | Positive | Negative | Positive (Ct 35.5) | Negative (Ct 38.1)a) | 1 |
a)The cutoff Ct value for toxin B in the Xpert C. difficile assay was 38.0. However, the Ct value near the cutoff value of the toxin B gene can be used for further evaluation.
Abbreviations: QCC, C. Diff Quik Chek Complete; RIDA, RIDASCREEN C. difficile assay; GDH, glutamate dehydrogenase; Ct, cycle threshold.