title: Effects of positive results for Mycobacterium avium subsp paratuberculosis as determined by microbial culture of feces or antibody ELISA on results of caudal fold tuberculin test and interferon-gamma assay for tuberculosis in cattle.
abstract: OBJECTIVE
  To determine whether cattle testing positive for Mycobacterium avium subsp paratuberculosis as determined by microbial culture of feces or antibody ELISA were more likely to have false-positive responses on the caudal fold tuberculin (CFT) test or interferon-gamma (IFN-gamma) assay for Mycobacterium bovis than cattle testing negative for M paratuberculosis.
  
  
  METHODS
  1043 cattle from 10 herds in Michigan.
  
  
  METHODS
  Feces and blood samples for plasma were collected from cattle > or =24 months old on the day the CFT test was read. Fecal samples were submitted for microbial culture for M paratuberculosis. Plasma samples were tested for antibody against M paratuberculosis, and IFN-gamma after stimulation with purified protein derivative tuberculin from M bovis or M avium.
  
  
  RESULTS
  Of 1043 cattle, 180 (17.3%) had positive CFT test results (suspects) and 8 (0.8%) had positive IFN-gamma assay results after stimulation with purified protein derivative tuberculin from M bovis. Forty-five (4.3%) and 115 (11.0%) cattle tested positive for M paratuberculosis as determined by microbial culture of feces and antibody ELISA, respectively. Cattle with positive responses for M paratuberculosis appeared to have an increased likelihood of false-positive results on the CFT test, although this association was not significant.
  
  
  CONCLUSIONS
  No significant association was detected among cattle testing positive for M paratuberculosis as determined by microbial culture of feces and antibody ELISA and positive CFT test and IFN-gamma assay results for M bovis.
authors.affiliation: Population Medicine Center, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA.
authors.forename: John R
authors.initials: JR
authors.lastname: Dunn
authors.forename: John B
authors.initials: JB
authors.lastname: Kaneene
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Grooms
authors.forename: Steven R
authors.initials: SR
authors.lastname: Bolin
authors.forename: Carole A
authors.initials: CA
authors.lastname: Bolin
authors.forename: Colleen S
authors.initials: CS
authors.lastname: Bruning-Fann
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood*; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis* / Q000276:immunology; D015169:Colony Count, Microbial / Q000662:veterinary; D003429:Cross Reactions; D003937:Diagnosis, Differential; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000662:veterinary; D005189:False Positive Reactions; D005243:Feces / Q000382:microbiology; D007371:Interferon-gamma / Q000097:blood*; D016927:Mycobacterium avium subsp. paratuberculosis / Q000276:immunology; D009163:Mycobacterium bovis / Q000276:immunology; D010283:Paratuberculosis / Q000175:diagnosis* / Q000276:immunology; D012680:Sensitivity and Specificity; D014374:Tuberculin Test / Q000379:methods / Q000662:veterinary; D014380:Tuberculosis, Bovine / Q000175:diagnosis* / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D007371:Interferon-gamma