Evaluation of two enzyme immunoassays for detection of Clostridium difficile toxins A and B in swine.
Diagnosis of Clostridium difficile-associated disease (CDAD) in neonatal pigs is accomplished, in part, by detection of toxins A (TcdA) and B (TcdB) in feces or colonic contents. Samples (n=115) were tested simultaneously with two toxin assays (Clostridium difficile Tox A/B II, TechLab, Blacksburg, VA; Gastro-tect Clostridium difficile Toxin A+B, Medical Chemical Corporation). Previous comparison of the Tox A/B II assay to the reference method (toxicity in CHO cell monolayers) revealed an overall correlation of 88%, with 91% sensitivity and 86% specificity, a positive predictive value of 86 and a negative predictive value of 84. In comparing the two EIAs, a group of nine samples were positive in both assays and a group of 92 were negative in both. However, 14 samples positive in the Tox A/B II were negative in the Gastro-tect assay. Thus, in comparison to the Tox A/B II assay, the Gastro-tect assay was 100% specific but only 39% sensitive. Its negative predictive value was 87, but its positive predictive value was 100. Thus, the Tox A/B II kit is apparently superior to the Gastro-tect Toxin A+B test for diagnosis of CDAD in neonatal pigs.
Anderson
Michael A
MA
Department of Veterinary Science and Microbiology, The University of Arizona, Tucson, AZ 85721, USA.
Songer
J Glenn
JG
D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis / Q000378:metabolism; D001426:Bacterial Proteins / Q000032:analysis*; D001427:Bacterial Toxins / Q000032:analysis*; D016360:Clostridioides difficile / Q000276:immunology / Q000302:isolation & purification*; D003106:Colon / Q000737:chemistry; D004761:Enterocolitis, Pseudomembranous / Q000175:diagnosis / Q000276:immunology / Q000662:veterinary*; D004768:Enterotoxins / Q000032:analysis*; D005243:Feces / Q000737:chemistry; D005766:Gastrointestinal Contents / Q000737:chemistry; D007124:Immunoenzyme Techniques / Q000379:methods / Q000592:standards / Q000662:veterinary*; D011237:Predictive Value of Tests; D013552:Swine; D013553:Swine Diseases / Q000175:diagnosis* / Q000276:immunology
D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004768:Enterotoxins; C041348:tcdA protein, Clostridium difficile; C031815:toxB protein, Clostridium difficile