BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: Both molecular assays were easy to use, rapid, sensitive, and specific for the detection of toxigenic CD strains.
BACKGROUND: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. METHODS: 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. RESULTS: 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. CONCLUSIONS: Both molecular assays were easy to use, rapid, sensitive, and specific for the detection of toxigenic CD strains.
Authors: Colleen S Kraft; J Scott Parrott; Nancy E Cornish; Matthew L Rubinstein; Alice S Weissfeld; Peggy McNult; Irving Nachamkin; Romney M Humphries; Thomas J Kirn; Jennifer Dien Bard; Joseph D Lutgring; Jonathan C Gullett; Cassiana E Bittencourt; Susan Benson; April M Bobenchik; Robert L Sautter; Vickie Baselski; Michel C Atlas; Elizabeth M Marlowe; Nancy S Miller; Monika Fischer; Sandra S Richter; Peter Gilligan; James W Snyder Journal: Clin Microbiol Rev Date: 2019-05-29 Impact factor: 26.132
Authors: E Bouza; J M Aguado; L Alcalá; B Almirante; P Alonso-Fernández; M Borges; J Cobo; J Guardiola; J P Horcajada; E Maseda; J Mensa; N Merchante; P Muñoz; J L Pérez Sáenz; M Pujol; E Reigadas; M Salavert; J Barberán Journal: Rev Esp Quimioter Date: 2020-02-20 Impact factor: 1.553