Medline ® Abstracts for References 83,84
of 'Clostridium difficile infection in adults: Clinical manifestations and diagnosis'
Comparison of the VIDAS Clostridium difficile toxin A immunoassay with C. difficile culture and cytotoxin and latex tests.
Shanholtzer CJ, Willard KE, Holter JJ, Olson MM, Gerding DN, Peterson LR
J Clin Microbiol. 1992;30(7):1837.
The VIDAS Clostridium difficile toxin A immunoassay (CDA) is a new, automated, enzyme-linked fluorescent-antibody assay for detection of C. difficile toxin A antigen in stool specimens. Simultaneous, parallel testing was performed by using the VIDAS CDA, the Culturette brand CDT latex test for C. difficile antigens, and conventional laboratory cell culture tests for C. difficile, cytotoxicity and C. difficile culture. One hundred ninety-four consecutive fresh soft or liquid stool samples submitted for C. difficile testing between July and September 1990 were evaluated. Of the 194 samples tested, 19 (10%) were from 16 patients who met our case definition for C. difficile-associated disease. The in vitro tests were evaluated in relation to two forms of a clinical case definition. In one form, a positive culture for toxin-producing C. difficile or a positive cytotoxin result obtained directly from the stool specimen was required as laboratory evidence of C. difficile. In the other, a positive result of any of the four laboratory tests was accepted for the laboratory portion of the case definition. No significant difference between the sensitivity of the VIDAS CDA and that of the Culturette brand CDT latex test was found (48 to 58% sensitivity for the CDT latex test and 52 to 63% sensitivity for the VIDAS CDA compared with 93 to 100% sensitivity for culture and 70 to 100%sensitivity for cytotoxin testing). The performance of the VIDAS CDA, however, was hampered by a high percentage of tests (19%) which gave an uninterpretable result.
Clinical Microbiology Section, Minneapolis VA Medical Center, Minnesota.
Enzyme immunoassays for detection of Clostridium difficile toxins A and B in fecal specimens.
Laughon BE, Viscidi RP, Gdovin SL, Yolken RH, Bartlett JG
J Infect Dis. 1984;149(5):781.
Enzyme immunoassays for detection of Clostridium difficile toxins A and B were developed with use of a double-sandwich microtiter plate format. Each assay was specific for its respective toxin and was sensitive to 0.1 ng of toxin. Neither assay was reactive with 13 other species of clostridia. One hundred fifty fecal specimens submitted for tissue culture cytotoxicity assay were evaluated by enzyme-linked immunosorbent assay (ELISA). Of the 79 tissue culture-positive specimens, 72 (91%) were positive in the A assay, 63 (80%) were positive in the B assay, and 75 (95%) were positive in either assay. Specimens with tissue culture titers of greater than or equal to 10(3) were uniformly positive in both assays. The specificities of the toxin A and B ELISAs were 98.6% and 100%, respectively. An ELISA for both toxins could serve as a substitute for the tissue culture cytotoxicity assay.