title: Evaluation of five enzyme immunoassays compared with the cytotoxicity assay for diagnosis of Clostridium difficile-associated diarrhea in dogs.
abstract: Clostridium difficile-associated-diarrhea (CDAD) is a nosocomial infection in dogs. Diagnosis of this infection is dependent on clinical signs of disease supported by laboratory detection of C. difficile toxins A or B, or both, in fecal specimens via enzyme-linked immunosorbent assay (ELISA). Unfortunately, to the authors' knowledge, commercially available ELISAs have not been validated in dogs to date. We evaluated 5 ELISAs done on 143 canine fecal specimens (100 diarrheic and 43 nondiarrheic dogs) and on 29 C. difficile isolates. The results of each ELISA were compared with the cytotoxin B tissue culture assay (CTA). Clostridium difficile was isolated from 23% of the fecal specimens. Eighteen of the 143 fecal specimens were toxin positive (15 diarrheic and 3 nondiarrheic dogs). On the basis of multiplex polymerase chain reaction (PCR) analysis for toxin-A and -B genes, 72% of the isolates were toxigenic. The carriage rate of toxigenic isolates in diarrheic dogs was higher than that in the nondiarrheic dogs; however, these differences were not statistically significant. A good correlation was found between CTA, PCR, and culture results. The ELISAs done on fecal specimens collected from diarrheic dogs had low sensitivity (7-33%). In contrast, ELISA for toxin A or B, or both, performed on toxigenic isolates had high sensitivity (93%). These results suggest that commercially available human ELISAs are inadequate for the diagnosis of canine C. difficile-associated diarrhea when tested on fecal specimens. In contrast, the Premier ToxinA/B and Techlab ToxinA/B ELISAs may be useful for the diagnosis of canine CDAD when used on toxigenic isolates.
authors.affiliation: University of California, Davis, School of Veterinary Medicine, Department of Medicine and Epidemiology, CA 95616, USA.
authors.forename: Nadira
authors.initials: N
authors.lastname: Chouicha
authors.forename: Stanley L
authors.initials: SL
authors.lastname: Marks
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000032:analysis; D001427:Bacterial Toxins / Q000032:analysis; D016360:Clostridioides difficile / Q000235:genetics / Q000302:isolation & purification*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D003967:Diarrhea / Q000175:diagnosis / Q000382:microbiology / Q000662:veterinary*; D004283:Dog Diseases / Q000175:diagnosis / Q000382:microbiology*; D004285:Dogs; D004761:Enterocolitis, Pseudomembranous / Q000175:diagnosis / Q000382:microbiology / Q000662:veterinary*; D004768:Enterotoxins / Q000032:analysis; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000662:veterinary*; D005243:Feces / Q000737:chemistry / Q000382:microbiology; D016133:Polymerase Chain Reaction / Q000662:veterinary; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004269:DNA, Bacterial; D004768:Enterotoxins; D011933:Reagent Kits, Diagnostic; C041348:tcdA protein, Clostridium difficile; C031815:toxB protein, Clostridium difficile