title: Investigation of the cause of geographic disparities in IDEXX ELISA sensitivity in serum samples from Mycobacterium bovis-infected cattle.
abstract: Accurately identifying Mycobacterium bovis-infected cattle is critical for bovine tuberculosis prevention and control. One method for identifying infected cattle is an ELISA developed by IDEXX laboratories, which detects antibodies to two M. bovis proteins, MPB70 and MPB83. The assay's sensitivity varies by geographic region, with sensitivities of 77%, 45%, and 9% in bovine serum samples from the United Kingdom (n = 126), the United States (n = 146), and Mexico (n = 128), respectively. We hypothesized that geographically-biased sequence variation in mpb70 and mpb83, or in the genes that regulate their expression (sigK and rskA), may explain these differing sensitivities. This hypothesis was tested by comparing the sequences of these four genes in 455 M. bovis strains isolated from cattle in the aforementioned countries. For each gene, a single, common sequence was identified in most genomes of the M. bovis strains collected in all three countries. Twelve of the 455 strains were isolated from infected cattle for which the IDEXX ELISA was also performed. Five of the seven ELISA-positive genomes and three of the five ELISA-negative genomes contained the most common sequence of all four genes. Thus, sequence variation in mpb70, mpb83, sigK, and rskA does not explain the geographic disparities in IDEXX ELISA sensitivity.
authors.affiliation: Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E3, Canada.|Department of Computer Science, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
authors.forename: Brett
authors.initials: B
authors.lastname: Trost
authors.affiliation: National Veterinary Services Laboratories, Animal and Plant Health Inspection Service, United States Department of Agriculture, Ames, Iowa 50010, USA.
authors.forename: Tod
authors.initials: T
authors.lastname: Stuber
authors.affiliation: Canadian Food Inspection Agency, Ottawa, Ontario K2H 8P9, Canada.
authors.forename: Om
authors.initials: O
authors.lastname: Surujballi
authors.affiliation: National Veterinary Services Laboratories, Animal and Plant Health Inspection Service, United States Department of Agriculture, Ames, Iowa 50010, USA.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Nelson
authors.affiliation: National Veterinary Services Laboratories, Animal and Plant Health Inspection Service, United States Department of Agriculture, Ames, Iowa 50010, USA.
authors.forename: Suelee
authors.initials: S
authors.lastname: Robbe-Austerman
authors.affiliation: Animal and Plant Health Agency, New Haw, Surrey KT15 3NB, United Kingdom.
authors.forename: Noel H
authors.initials: NH
authors.lastname: Smith
authors.affiliation: Canadian Cattlemen's Association, Calgary, Alberta T2E 7H7, Canada.
authors.forename: Louis
authors.initials: L
authors.lastname: Desautels
authors.affiliation: Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E3, Canada.|Vaccinology &Immunotherapeutics Program, School of Public Health, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E3, Canada.
authors.forename: Suresh K
authors.initials: SK
authors.lastname: Tikoo
authors.affiliation: Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E3, Canada.|Vaccinology &Immunotherapeutics Program, School of Public Health, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E3, Canada.
authors.forename: Philip
authors.initials: P
authors.lastname: Griebel
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000378:metabolism; D000942:Antigens, Bacterial / Q000235:genetics / Q000276:immunology; D001426:Bacterial Proteins / Q000235:genetics* / Q000276:immunology; D002417:Cattle; D004797:Enzyme-Linked Immunosorbent Assay; D014644:Genetic Variation; D008565:Membrane Proteins / Q000235:genetics / Q000276:immunology; D008800:Mexico; D009163:Mycobacterium bovis / Q000145:classification* / Q000235:genetics* / Q000276:immunology; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA / Q000379:methods*; D014380:Tuberculosis, Bovine / Q000175:diagnosis* / Q000276:immunology; D006113:United Kingdom; D014481:United States
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C094904:MPB83 protein, Mycobacterium; D008565:Membrane Proteins; C060216:MPB70 protein, Mycobacterium bovis