title: Comparison of BD Max Cdiff and GenomEra C. difficile molecular assays for detection of toxigenic Clostridium difficile from stools in conventional sample containers and in FecalSwabs.
abstract: In this study, the usability and performance of GenomEra™ C. difficile and BD Max™ Cdiff nucleic acid amplification tests (NAATs) for the detection of toxigenic Clostridium difficile were investigated in comparison with toxigenic culture and C. difficile toxin A- and toxin B-detecting immunochromatographic antigen (IA) test, the Tox A/B QuikChek®. In total, 302 faecal specimens were collected, 113 of which were in parallel to conventional sample containers and FecalSwab liquid-based microbiology (LBM) tubes. Seventy-nine specimens were considered true-positives for toxigenic C. difficile. The sensitivity and specificity were 97.5 % and 99.6 % and 93.7 % and 98.7 % for the GenomEra and BD Max assays respectively. Toxigenic culture and Tox A/B QuikChek had sensitivity and specificity of 91.1 % and 100 % and 34.2 % and 100 % respectively. Hands-on time for analysing 1 to 24 specimens using NAATs was 1 to 15 min. The rate of PCR inhibition was 0 % for both NAATs with faeces in LBM tubes, while with faeces in conventional sample containers the respective inhibition rates were 5.3 % and 4.4 % for the GenomEra and the BD Max assays. The NAATs demonstrated an excellent analytical performance, reducing significantly the overall workload of laboratory personnel compared with culture and IA test.
authors.affiliation: Department of Clinical Microbiology, Vaasa Central Hospital, Hietalahdenkatu 2-4 B2, 65130, Vaasa, Finland, jari.hirvonen@fimlab.fi.
authors.forename: J J
authors.initials: JJ
authors.lastname: Hirvonen
authors.forename: S-S
authors.initials: SS
authors.lastname: Kaukoranta
mesh_terms: D036002:ADP Ribose Transferases / Q000032:analysis* / Q000235:genetics; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001426:Bacterial Proteins / Q000032:analysis* / Q000235:genetics; D001431:Bacteriological Techniques / Q000379:methods*; D002648:Child; D016360:Clostridioides difficile / Q000302:isolation & purification*; D003015:Clostridium Infections / Q000175:diagnosis* / Q000382:microbiology; D003967:Diarrhea / Q000175:diagnosis* / Q000382:microbiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D021141:Nucleic Acid Amplification Techniques / Q000379:methods; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013997:Time Factors; D055815:Young Adult
chemical_list: D001426:Bacterial Proteins; D036002:ADP Ribose Transferases; C410164:actin-specific ADP-ribosyltransferase, Clostridium