title: Rapid detection of Clostridium difficile toxins from stool samples using real-time multiplex PCR.
abstract: In this study, a total of 650 stool samples were tested to show that our method is capable of detecting four Clostridium difficile genes; tcdA, tcdB, encoding toxin A (TcdA) and toxin B (TcdB), and the binary toxin C. difficile transferase genes (cdtA and/or cdtB) encoding CDT toxin. Besides detecting the targeted C. difficile genes, our method can be used to detect the presence of any inhibitory components in the PCR. This assay, combined with a selective culture medium, such as the chromID™ C. difficile, can be applied directly for screening C. difficile-associated disease. The PCR-based assay developed here is rapid (4 h per 21 stool samples) and accurate in diagnosing C. difficile infection, 100 % assay sensitivity and negative predictive value (NPV) were obtained. However, the assay specificity of 99.1 % and positive predictive value (PPV) of 94.9 % were slightly lower than the optimal value of 100 %. The assay protocol outlined here can be used as a rapid screening tool to assist infection control units and in managing infected patients by reducing the number of patients requiring isolation and extended hospitalization. Rapid detection can prevent unnecessary antibiotic therapy and potentially reduce the spread of infection by emerging hypervirulent C. difficile strains.
authors.affiliation: Molecular Diagnostic and Microbiology Laboratory, Austin Pathology, Melbourne, VIC 3084, Australia.
authors.forename: Ann
authors.initials: A
authors.lastname: Pallis
authors.affiliation: School of Biomedical Sciences, Charles Sturt University, Boorooma Street, Wagga Wagga, NSW 2678, Australia.
authors.forename: Jalal
authors.initials: J
authors.lastname: Jazayeri
authors.affiliation: Molecular Diagnostic and Microbiology Laboratory, Austin Pathology, Melbourne, VIC 3084, Australia.
authors.forename: Peter
authors.initials: P
authors.lastname: Ward
authors.affiliation: Microbiology Diagnostic Unit, Parkville, VIC 3052, Australia.
authors.forename: Karolina
authors.initials: K
authors.lastname: Dimovski
authors.affiliation: Molecular Diagnostic and Microbiology Laboratory, Austin Pathology, Melbourne, VIC 3084, Australia.
authors.forename: Suzanne
authors.initials: S
authors.lastname: Svobodova
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D001427:Bacterial Toxins / Q000235:genetics; D016360:Clostridioides difficile / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D003015:Clostridium Infections / Q000175:diagnosis; D003470:Culture Media / Q000378:metabolism; D004768:Enterotoxins / Q000235:genetics; D005243:Feces / Q000382:microbiology*; D005798:Genes, Bacterial; D006801:Humans; D060885:Multiplex Polymerase Chain Reaction / Q000379:methods*; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; D003470:Culture Media; D004768:Enterotoxins; C041348:tcdA protein, Clostridium difficile; C031815:toxB protein, Clostridium difficile