title: Portrait Toxigenic Clostridium difficile assay, an isothermal amplification assay detects toxigenic C. difficile in clinical stool specimens.
abstract: The Portrait Toxigenic Clostridium difficile assay is a rapid, qualitative assay for the detection of the tcdB gene of C. difficile in stool specimens from patients suspected of C. difficile infections, and received 510(k) clearance by the US FDA in March 2012. The Portrait Toxigenic C. difficile assay combines novel blocked-primer-mediated helicase-dependent multiplex amplification (bpHDA) technology and chip-based detection in an automated sample-to-result format. The assay requires minimal sample preparation and results are available within 90 min. In a multicenter evaluation, the Portrait Toxigenic C. difficile assay had a sensitivity of 98.2% and specificity of 92.8% compared with toxigenic culture. A comparative study between the Portrait Toxigenic C. difficile assay and three FDA-cleared molecular assays for the detection of toxigenic C. difficile exhibited a high degree of agreement (93.8-97.5%). The Portrait Toxigenic C. difficile assay provides a simple, cost-effective method with broad applicability to panel-based approaches, potentially simplifying workflow.
authors.affiliation: Department of Pathology and Laboratory Medicine, Division of Clinical Microbiology, Indiana University School of Medicine, 350 West 11th Street, Room 6027B, Indianapolis, IN, USA.
authors.forename: Gerald A
authors.initials: GA
authors.lastname: Denys
mesh_terms: D016360:Clostridioides difficile / Q000235:genetics*; D004269:DNA, Bacterial / Q000235:genetics; D003967:Diarrhea / Q000175:diagnosis* / Q000382:microbiology; D004761:Enterocolitis, Pseudomembranous / Q000175:diagnosis* / Q000382:microbiology; D005243:Feces / Q000382:microbiology*; D006801:Humans; D025202:Molecular Diagnostic Techniques; D021141:Nucleic Acid Amplification Techniques; D012680:Sensitivity and Specificity
chemical_list: D004269:DNA, Bacterial