Abstract
We evaluated a multiplex real-time polymerase chain reaction (PCR) system of the Xpert C. difficile PCR assay (Xpert CD, Beckman Coulter) that detects tcdB of Clostridioides difficile directly from the stool. Loose stool specimens (n = 250) were analyzed by toxigenic culture (TC), Xpert CD, and C. DIFF QUIK CHEK COMPLETE (COMPLETE, Abbott). Given that the results of TC are correct, the sensitivities for toxin were 100% and 17.6% for Xpert CD and COMPLETE, respectively. Seven of the 250 samples showed discordant results among the three methods. The reasons considered were as follows: the levels of toxin were below the detection limit of COMPLETE for two cases, false negative in the TC for four cases, and one CDI case detected only by Xpert CD probably because it is not affected by the viability of the bacterium. These results suggest that Xpert CD is superior to TC. However, considering that false positive/negative results can be obtained in any of these methods, it is important that the diagnosis of CDI requires the evaluation of both clinical symptoms and test results. Replacing TC with Xpert CD may reduce unnecessary infection control owing to its short turnaround time. In conclusion, Xpert CD can be a choice for the accurate and rapid diagnosis of CDI.
