title: [Diagnosis of Clostridium difficile infections: comparative study of two immuno enzyme assays with confirmation by PCR and culture followed by PCR ribotyping].
abstract: OBJECTIVE
  Comparison of two commercially avail-able tests for the detection of Clostridium difficile Glutamate Dehydrogenase (GDH) and toxins A and B for their sensitivity and specificity.
  
  
  METHODS
  Eighty-six stool samples from patients hospitalised in the Motol University Hospital were analysed. GDH and toxins A and B were assayed in parallel by two tests: C. difficile Quik Chek Complete® (Techlab, USA) and Liaison® C. difficile GDH and Toxins AαB (DiaSorin, USA). From the stool samples, nucleic acids were also isolated using the UltraClean® Fecal DNA kit (MoBio Laboratories, USA). The commercially available C. difficile Elite MGB® kit (Nanogen, Italy) was used for the polymerase chain reaction (PCR). Anaerobic culture on C. difficile selective medium (Oxoid) was performed for all positive samples at least in one test. Pure isolates were characterized by PCR ribotyping.
  
  
  RESULTS
  Thirty-six (42%) samples were GDH negative and toxin A/B negative by both tests. Twenty (23%) samples were GDH positive and toxin A/B positive by both tests. Nine (10%) samples were GDH positive and toxin negative by both tests, but were positive by PCR. Eleven (13%) samples that were GDH positive and toxin negative by both tests remained negative by PCR. Six (7%) samples only were GDH positive and toxin positive by the Liaison® test alone. Four (5%) samples were GDH-positive by theLiaison® test alone. Culture failure was observed in 11 (13%) samples, of which seven were positive by PCR. PCR was inhibited in five (6%) samples. The following toxigenic ribotypes: AI-3, 001, 002, 012,014, 017, 020, 049, 054, 078, 176, 203, and 413 and non-toxigenic ribotypes: AI-34, AI-61, 010, 485, 495, and 596 were identified.
  
  
  CONCLUSIONS
  The Liaison® test had seven percent higher sensitivity for the detection of toxins A/B. The two-step protocol of the tests is also cost-saving. The savings can be used e.g. for incorporating the PCR techniques into the diagnostic algorithm of the laboratory.
authors.forename: M
authors.initials: M
authors.lastname: Krůtová
authors.forename: J
authors.initials: J
authors.lastname: Matějková
authors.forename: M
authors.initials: M
authors.lastname: Zajac
authors.forename: P
authors.initials: P
authors.lastname: Hubáček
authors.forename: O
authors.initials: O
authors.lastname: Nyč
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis; D001427:Bacterial Toxins / Q000032:analysis; D016360:Clostridioides difficile / Q000145:classification; D003015:Clostridium Infections / Q000175:diagnosis*; D004768:Enterotoxins / Q000032:analysis; D005969:Glutamate Dehydrogenase / Q000032:analysis; D006801:Humans; D007124:Immunoenzyme Techniques; D016133:Polymerase Chain Reaction; D021521:Ribotyping
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004768:Enterotoxins; C041348:tcdA protein, Clostridium difficile; C031815:toxB protein, Clostridium difficile; D005969:Glutamate Dehydrogenase