Performance of the TechLab C. DIFF CHEK-60 enzyme immunoassay (EIA) in combination with the C. difficile Tox A/B II EIA kit, the Triage C. difficile panel immunoassay, and a cytotoxin assay for diagnosis of Clostridium difficile-associated diarrhea.
We compared a recently marketed enzyme immunoassay for glutamate dehydrogenase (GDH), TechLab's C. DIFF CHEK-60 (TL-GDH), in combination with the C. difficile Tox A/B II enzyme immunoassay (Tox-A/B) with (i) the Triage C. difficile test, which detects both GDH (TR-GDH) and toxin A (TR-Tox-A); (ii) an in-house cytotoxin assay (C-Tox); and (iii) stool cultures for C. difficile. All C. difficile isolates were tested for the presence of the toxin genes by PCR. If a toxin gene-positive strain of Clostridium difficile was recovered and a toxin was detected by any method, the result was considered to be truly positive. Eighty-seven of 93 and 79 of 93 C. difficile culture-positive samples were also TL-GDH and TR-GDH positive, respectively. No test was able to detect toxin in all samples with true-positive results. Tox-A/B and TR-Tox-A in combination with the GDH detection tests and C-Tox were able to identify 52 and 50 samples with true-positive results. Tox-A/B and TR-Tox-A would have missed 15 and 31% of cases of C. difficile-associated diarrhea, respectively, if used alone.
Department of Clinical Microbiology and Infection Control, London Health Sciences Centre, London, Ontario, Canada.
Heather
H
Snell
Meredith
M
Ramos
Sue
S
Longo
Michael
M
John
Zafar
Z
Hussain
D001426:Bacterial Proteins / Q000032:analysis; D001427:Bacterial Toxins / Q000032:analysis*; D016360:Clostridioides difficile / Q000302:isolation & purification*; D003967:Diarrhea / Q000175:diagnosis* / Q000382:microbiology; D004761:Enterocolitis, Pseudomembranous / Q000175:diagnosis* / Q000382:microbiology; D004768:Enterotoxins / Q000032:analysis; D005243:Feces / Q000382:microbiology; D005969:Glutamate Dehydrogenase / Q000378:metabolism; D006801:Humans; D007124:Immunoenzyme Techniques / Q000379:methods*; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity
D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004768:Enterotoxins; D011933:Reagent Kits, Diagnostic; C041348:tcdA protein, Clostridium difficile; C031815:toxB protein, Clostridium difficile; D005969:Glutamate Dehydrogenase