C. difficile

Enabling 1-step algorithm to detect toxigenic C. difficile reliably

Why choose our test?

The GenomEra® C. difficile Assay Kit offers a rapid and simple high-performance molecular assay for diagnosing a Clostridioides difficile infection from liquid or unformed stool samples in less than one hour.

Toxin producing C. difficile is a gram-positive, anaerobic, spore-forming bacterium. It is the most severe cause of antibiotic-associated diarrhea (AAD) and the most common cause of pseudomembranous colitis.1 Symptoms of C. difficile-associated disease (CDAD) often begin following antibiotic regimens.2

The current gold standard test—cell cytotoxicity assay—is highly sensitive and specific but technically demanding and slow, while rapid immunoassays are quick to perform but have insufficient sensitivity and specificity. Rapid, automated molecular tests are therefore in demand to improve patient outcomes and to prevent bacterial spread.

The GenomEra C. difficile DNA amplification assay allows reliable detection of the tcdB gene, which is considered the major virulence factor of toxigenic C. difficile.3 Toxigenic C. difficile strains lacking the tcdB gene are extremely rare.4

Key facts

  • A rapid molecular test for detecting the toxin B gene (tcdB) of Clostridioides difficile bacteria from stool samples in less than one hour
  • Simple, cost-effective, and reliable test for improved patient outcomes
  • High-performance results with automated result interpretation

Assay principle 

The GenomEra C. difficile Assay Kit is a rapid and easy-to-use automated test based on homogenous polymerase chain reaction (PCR) and used for the qualitative detection of the toxin B gene of C. difficile. The test utilizes end-point PCR to detect the tcdB gene, ensuring comprehensive coverage of the virulent C. difficile strains. The easy-to-use GenomEra CDX System combines the simplicity of rapid testing and the superior sensitivity of PCR methods in one reliable system.

The test is performed directly from liquid or unformed stool specimens, with very short and easy sample preparation and no need for DNA extraction. Molecular detection allows a significantly faster outcome compared to conventional methods, yielding automated test results on the GenomEra® Software in just 50 minutes. Pre-loaded and sealed GenomEra Test Chips ensure effortless sample handling and safe and easy waste disposal.

Clinical performance

The clinical performance of the GenomEra C. difficile Assay Kit was evaluated on 322 unpreserved stool samples (65 fresh, 257 frozen) at three study centers—two in Finland and one in the Netherlands (Table 1). The reference methods used in the evaluation were toxigenic culture and toxin A & B enzyme immunoassay.

Table 1. GenomEra® C. difficile Assay Kit proved highly sensitive and specific in clinical use. PPV, positive predictive value; NPV, negative predictive value.

Sample size Sensitivity (%, n) Specificity (%, n) PPV (%) NPV (%)
n = 322 99.0 (97/98) 99.1 (222/224) 98.0 99.6

Ordering information

To place an order, please contact your local distributor.

Product name Product code
GenomEra C. difficile Assay Kit
20 tests CDX-40-01-20
40 tests CDX-40-01-40
GenomEra CDX System CDX-10-020

The GenomEra C. difficile Assay Kit has received the European CE marking for In Vitro Diagnostic (IVD) medical devices according to the requirements of EU Directive 98/79/EC (IVDD) and is available in European markets. In other markets, please contact your local distributor for availability. The product is manufactured by Uniogen, Finland.


  1. Gerding D.N., Johnson S., Peterson L.R., Mulligan M.E., Silva J. Jr. Clostridium difficile-associated diarrhea and colitis. Infect Control Hosp Epidemiol 1995;16:459–77.
  2. Bartlett J.G. Clinical practice. Antibiotic-associated diarrhea. N Engl J Med 2002;346:334-9.
  3. Lyras D., C’Connor J.R., Howarth P.M., Sambol S.P., Carter G.P., Phumoonna T., Poon R., Adams V., Vedantam G., Johnson S., Gerding D.N., Rood J.I. Toxin B is essential for virulence of Clostridium difficile. Nature 2009;458:1176-9.
  4. Cohen S.H., Tang Y.J., Hansen B., Silva J. Jr. Isolation of a toxin B–deficient mutant strain of Clostridium difficile in a case of recurrent C. difficile–associated diarrhea. Clin Infect Dis 1998 26:410-2.

Additional literature

  1. Hirvonen J.J., Mentula S., Kaukoranta S-S. Evaluation of a new automated homogeneous PCR assay, GenomEra C. difficile, for rapid detection of Toxigenic Clostridium difficile in fecal specimens. J Clin Microbiol 2013; 51:2908-12.
  2. Savolainen R., Koskinen J.M., Mentula S., Koskinen J.O., Kaukoranta S-S. Prospective evaluation of the mariPOC test for detection of Clostridioides difficile glutamate dehydrogenase and toxins A/B. J Clin Microbiol 2020;58:e01872-19.
  3. Azrad M., Tkhawkho L., Hamo Z., Peretz A. The diagnostic performance and accuracy of 3 molecular assays for the detection of Clostridium difficile in stool samples, compared with the Xpert® C. difficile assay. J Microbiol Methods 2020;168:105784.
  4. Paitan Y., Miller-Roll T., Adler A. Comparative performance study of six commercial molecular assays for rapid detection of toxigenic Clostridium difficile. Clin Microbiol Infect 2017;23:567-572.
  5. Hirvonen J.J., Kaukoranta S-S. Comparison of BD Max Cdiff and GenomEra C. difficile molecular assays for detection of toxigenic Clostridium difficile from stools in conventional sample containers and in FecalSwabs. Eur J Clin Microbiol Infect Dis 2015;35:1005-9.
  6. Alcalá L., Reigadas E., Marín M., Fernández-Chico A., Catalán P., Bouza E. Comparison of GenomEra C. difficile and Xpert C. difficile as confirmatory tests in a multistep algorithm for diagnosis of Clostridium difficile infection. J Clin Microbiol 2015;53:332-5.



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