title: Real-time polymerase chain reaction method for detection of toxigenic Clostridium difficile from stools and presumptive identification of NAP1 clone.
abstract: This study describes the development of a cost-effective, multiplex real-time polymerase chain reaction (RTPCR) method for detection of toxigenic Clostridium difficile from stools and presumptive identification of the NAP-1 strain. The diagnostic value of the new method is for the detection of toxigenic C. difficile which has the following performance characteristics: 99.8% specificity, 95.1% sensitivity, 97.5% positive predictive value, and 99.5% negative predictive value. Examination of 24 specimens presumptively identified as NAP1 strain by RTPCR with Pulsed-field gel electrophoresis performed on C. difficile isolated from those specimens showed 100% agreement. This RTPCR showed equivalent test performance characteristics as the 2 commercially available assays which were evaluated. The estimated cost per test is CAD$9.50 and which is significantly less than the commercial assays. The average turnaround time from setup to detection is 3.5 h. The RTPCR method described here is a cost-effective and highly sensitive test which can be implemented in a clinical laboratory to assist clinicians in establishing the diagnosis of C. difficile infection and indirectly determine the presence of the hypervirulent epidemic binary toxin (BI)/NAP 1 strain for prompt infection control interventions.
authors.affiliation: Department of Pathology and Molecular medicine, McMaster University, Hamilton, Ontario, Canada. jayarpad@hhsc.ca
authors.forename: Padman A
authors.initials: PA
authors.lastname: Jayaratne
authors.forename: Lori
authors.initials: L
authors.lastname: Monkman
authors.forename: George
authors.initials: G
authors.lastname: Broukhanski
authors.forename: Dillan R
authors.initials: DR
authors.lastname: Pillai
authors.forename: Christine
authors.initials: C
authors.lastname: Lee
mesh_terms: D036002:ADP Ribose Transferases / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics; D016360:Clostridioides difficile / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D003428:Cross Infection / Q000382:microbiology; D004761:Enterocolitis, Pseudomembranous / Q000382:microbiology; D005243:Feces / Q000382:microbiology*; D005798:Genes, Bacterial; D006801:Humans; D009864:Ontario; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D012097:Repressor Proteins / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D012097:Repressor Proteins; C105615:TcdC protein, Clostridium difficile; D036002:ADP Ribose Transferases; C410164:actin-specific ADP-ribosyltransferase, Clostridium