Comparison of antigen and two molecular methods for the detection of Clostridium difficile toxins. (January 2013)

• Record Type: Journal Article
• Authors: Ylisiurua, Pirkko; Koskela, Markku; Vainio, Olli; Tuokko, Hanna
• Is Part Of: Scandinavian journal of infectious diseases. Volume 45:Number 1(2013:Jan.)
• Page Start: 19
• Page End: 25
• Publication Date: 2013-01
• Subjects: Communicable diseases -- Periodicals; Infection -- Periodicals; 616.9
• DOI: 10.3109/00365548.2012.708780
• Languages: English
• ISSNs: 0036-5548

Abstract

<abstract> <title>Abstract</title> <p> <italic>Background:</italic> Clostridium difficile (CD) is considered an important cause of diarrhoea associated with the antimicrobial treatment of infections. The pathogenicity of CD is due to toxins A and B, produced by toxigenic CD strains. <italic>Methods:</italic> We evaluated 3 methods for detecting CD toxins: the RIDASCREEN® enzyme immunoassay (EIA) (R-Biopharm) – one detecting toxins directly in the stool specimens and another detecting toxins from isolated CD strains – and 2 molecular methods, the illumigene™ loop-mediated isothermal amplification (LAMP) assay (Meridian) and RIDA®GENE polymerase chain reaction (PCR) assay (R-Biopharm), as direct identification methods from stool specimens. Toxigenic culture (TC) was used as the reference method. <italic>Results:</italic> Altogether 884 stool samples were analyzed, of which 253 (29%) were positive by TC. Six hundred and seventy-two specimens were tested by RIDASCREEN EIA, 430 were tested with the illumigene LAMP assay, and 212 were tested with the RIDA GENE PCR assay. CD toxin A and B antigen tests by EIA were very insensitive, both directly from stool specimens (2 series; 57–61%) and in isolated CD strains (53%); consequently the negative predictive value remained low (84–93% and 91%, respectively). Specificity, however, was very good at 98–100%. The 2 molecular methods detected CD toxin genes excellently and equally, resulting in sensitivities, specificities, and positive and negative predictive values of 98%, 100%, 100%, and 98%, respectively. <italic>Conclusions:</italic> Both molecular assays were easy to use, rapid, sensitive, and specific for the detection of toxigenic CD strains.</p> </abstract>