Comparison of a dot immunobinding assay, latex agglutination, and cytotoxin assay for laboratory diagnosis of Clostridium difficile-associated diarrhea.
C. diff-CUBE, a dot immunobinding assay (DIA) (Difco Laboratories, Ann Arbor, Mich.) for detection of Clostridium difficile toxin A in stool specimens, was compared with latex agglutination (LA) (Marion Laboratories, Kansas City, Mo.) and cytotoxin assay (CTA) for the laboratory diagnosis of C. difficile-associated diarrhea. A total of 200 stool specimens collected from 169 patients with suspected C. difficile diarrhea were tested. Of the 198 specimens evaluated by all three methods, 36 (18%) from 36 patients were positive by one or more of the tests. Twenty-five, 26, and 23 specimens were positive by CTA, DIA, and LA, respectively; 14 were positive by all three methods. Eight specimens yielded nonspecific LA test results; all eight were negative by CTA, and one was positive by DIA. DIA results agreed with CTA results in 183 (92%) cases and with LA results in 175 (88%) cases. CTA and LA results agreed in 179 (90%) cases. Freezing of the specimen did not appear to adversely affect either the DIA or LA test. These preliminary results suggest that C. diff-CUBE may be useful as a rapid screen for the diagnosis of C. difficile-associated diarrhea. However, for optimum laboratory diagnosis, further testing of all stools that are negative by DIA is warranted.
Woods
G L
GL
Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha 68105.
Iwen
P C
PC
D001427:Bacterial Toxins / Q000032:analysis; D001681:Biological Assay; D003015:Clostridium Infections / Q000175:diagnosis*; D003951:Diagnostic Errors; D003967:Diarrhea / Q000209:etiology*; D004768:Enterotoxins; D005069:Evaluation Studies as Topic; D005243:Feces / Q000032:analysis / Q000382:microbiology; D006801:Humans; D015151:Immunoblotting; D007841:Latex Fixation Tests
D001427:Bacterial Toxins; D004768:Enterotoxins; C041348:tcdA protein, Clostridium difficile