Klaus Nielsen

Summary

Affiliation: Canadian Food Inspection Agency
Country: Canada

Publications

  1. ncbi Validation of the fluorescence polarization assay and comparison to other serological assays for the detection of serum antibodies to Brucella abortus in bison
    D Gall
    Canadian Food Inspection Agency, Animal Diseases Research Institute, Nepean, Ontario, Canada
    J Wildl Dis 36:469-76. 2000
  2. ncbi Field trial of the brucellosis fluorescence polarization assay
    K Nielsen
    Animal Diseases Research Institute, Nepean, Ontario, Canada
    J Immunoassay Immunochem 23:307-16. 2002
  3. ncbi Failure to demonstrate involvement of antibodies to Acinetobacter calcoaceticus in transmissible spongiform encephalopathies of animals
    K Nielsen
    Animal Diseases Research Institute, Canadian Food Inspection Agency, 3851 Fallowfield Road, Nepean, Ont, Canada K2H 8P9
    Vet Immunol Immunopathol 89:197-205. 2002
  4. ncbi Diagnosis of brucellosis by serology
    Klaus Nielsen
    Animal Diseases Research Institute, 3851 Fallowfield Road, Nepean, Ont, Canada K2H 8P9
    Vet Microbiol 90:447-59. 2002
  5. ncbi Prion protein in sheep urine
    Olga Andrievskaia
    Canadian Food Inspection Agency, Ottawa Laboratory Fallowfield, 3851 Fallowfield Road, Ottawa, Ontario K2H 8P9, Canada
    J Vet Diagn Invest 20:141-6. 2008
  6. doi Validation and field assessment of a rapid lateral flow assay for detection of bovine antibody to Anaplasma marginale
    K Nielsen
    Canadian Food Inspection Agency, Ottawa Laboratory Fallowfield, Ottawa, Ontario, Canada
    J Immunoassay Immunochem 30:313-21. 2009
  7. ncbi Serological relationship between cattle exposed to Brucella abortus, Yersinia enterocolitica O:9 and Escherichia coli O157:H7
    K Nielsen
    Animal Diseases Research Institute, Canadian Food Inspection Agency, P O Box 11300, 3851 Fallowfield Road, Nepean, Ontario, Canada K2H 8P9
    Vet Microbiol 100:25-30. 2004
  8. ncbi Rough lipopolysaccharide of Brucella abortus RB51 as a common antigen for serological detection of B. ovis, B. canis, and B. abortus RB51 exposure using indirect enzyme immunoassay and fluorescence polarization assay
    K Nielsen
    Canadian Food Inspection Agency, Animal Diseases Research Institute, Ottawa, Ontario, Canada
    J Immunoassay Immunochem 25:171-82. 2004
  9. ncbi Enzyme immunoassay for the diagnosis of brucellosis: chimeric Protein A-Protein G as a common enzyme labeled detection reagent for sera for different animal species
    K Nielsen
    Animal Diseases Research Institute, Canadian Food Inspection Agency, 3851 Fallowfield Road, Nepean, Ont, Canada K2H 8P9
    Vet Microbiol 101:123-9. 2004
  10. ncbi Serological discrimination by indirect enzyme immunoassay between the antibody response to Brucella sp. and Yersinia enterocolitica O:9 in cattle and pigs
    K Nielsen
    Animal Diseases Research Institute, 3851 Fallowfield Road, Ottawa, Ont, Canada
    Vet Immunol Immunopathol 109:69-78. 2006

Detail Information

Publications42

  1. ncbi Validation of the fluorescence polarization assay and comparison to other serological assays for the detection of serum antibodies to Brucella abortus in bison
    D Gall
    Canadian Food Inspection Agency, Animal Diseases Research Institute, Nepean, Ontario, Canada
    J Wildl Dis 36:469-76. 2000
    ..These attributes, together, with its excellent sensitivity and specificity make the FPA an attractive test for the detection of serum antibodies to Brucella abortus in bison...
  2. ncbi Field trial of the brucellosis fluorescence polarization assay
    K Nielsen
    Animal Diseases Research Institute, Nepean, Ontario, Canada
    J Immunoassay Immunochem 23:307-16. 2002
    ..1% and the relative specificity of the FPA(bld) was 99.6%. These results compared favourably with those obtained using the other serological tests...
  3. ncbi Failure to demonstrate involvement of antibodies to Acinetobacter calcoaceticus in transmissible spongiform encephalopathies of animals
    K Nielsen
    Animal Diseases Research Institute, Canadian Food Inspection Agency, 3851 Fallowfield Road, Nepean, Ont, Canada K2H 8P9
    Vet Immunol Immunopathol 89:197-205. 2002
    ..calcoaceticus being a cause of TSEs...
  4. ncbi Diagnosis of brucellosis by serology
    Klaus Nielsen
    Animal Diseases Research Institute, 3851 Fallowfield Road, Nepean, Ont, Canada K2H 8P9
    Vet Microbiol 90:447-59. 2002
    ....
  5. ncbi Prion protein in sheep urine
    Olga Andrievskaia
    Canadian Food Inspection Agency, Ottawa Laboratory Fallowfield, 3851 Fallowfield Road, Ottawa, Ontario K2H 8P9, Canada
    J Vet Diagn Invest 20:141-6. 2008
    ..3-4.7 ng/ml) of PrP(C) in urine. The origin of PrP(C) in urine and the reason for the increased level of PrP(C) in scrapie-infected sheep urine has yet to be explored...
  6. doi Validation and field assessment of a rapid lateral flow assay for detection of bovine antibody to Anaplasma marginale
    K Nielsen
    Canadian Food Inspection Agency, Ottawa Laboratory Fallowfield, Ottawa, Ontario, Canada
    J Immunoassay Immunochem 30:313-21. 2009
    ..5% for the CELISA and 98.0% for the LFA. It is envisaged that the validated LFA will be a useful tool for screening cattle moving from an area with infection to a disease-free area...
  7. ncbi Serological relationship between cattle exposed to Brucella abortus, Yersinia enterocolitica O:9 and Escherichia coli O157:H7
    K Nielsen
    Animal Diseases Research Institute, Canadian Food Inspection Agency, P O Box 11300, 3851 Fallowfield Road, Nepean, Ontario, Canada K2H 8P9
    Vet Microbiol 100:25-30. 2004
    ..coli O157:H7, Y. enterocilitica O:9 and B. abortus is dependent on the test used. Thus, extensive cross reaction was observed with the IELISA with much less reactivity in the FPA and the CELISA...
  8. ncbi Rough lipopolysaccharide of Brucella abortus RB51 as a common antigen for serological detection of B. ovis, B. canis, and B. abortus RB51 exposure using indirect enzyme immunoassay and fluorescence polarization assay
    K Nielsen
    Canadian Food Inspection Agency, Animal Diseases Research Institute, Ottawa, Ontario, Canada
    J Immunoassay Immunochem 25:171-82. 2004
    ..B. abortus RB51 core labeled with fluorescein resulted in sensitivity and specificity values of 93.5% and 99.8%, respectively, with bovine sera and 78.1% and 99.0% with sheep sera. It was not possible to test the dog sera in the FPA...
  9. ncbi Enzyme immunoassay for the diagnosis of brucellosis: chimeric Protein A-Protein G as a common enzyme labeled detection reagent for sera for different animal species
    K Nielsen
    Animal Diseases Research Institute, Canadian Food Inspection Agency, 3851 Fallowfield Road, Nepean, Ont, Canada K2H 8P9
    Vet Microbiol 101:123-9. 2004
    ..An added advantage was that a universal cut-off for all tests using the proteins A and G detection reagent could be established, simplifying diagnostic interpretation of the data...
  10. ncbi Serological discrimination by indirect enzyme immunoassay between the antibody response to Brucella sp. and Yersinia enterocolitica O:9 in cattle and pigs
    K Nielsen
    Animal Diseases Research Institute, 3851 Fallowfield Road, Ottawa, Ont, Canada
    Vet Immunol Immunopathol 109:69-78. 2006
    ..enterocolitica O:9 were negative while only 20 sera from 121 'false positive' reactors of unspecified origin gave low level positive reactions, eliminating 84% of the false positive reactions...
  11. ncbi Detection of anti-Brucella antibodies in llama (Llama glama)
    K Nielsen
    Canadian Food Inspection Agency, Ottawa Laboratories Fallowfield, Ontario, Canada
    J Immunoassay Immunochem 28:61-6. 2007
    ..8% to 100% specific although some sera gave an 'agglutination like' reaction after about 10 minutes of incubation. The complement fixation test could not be used, as 31% of the sera were anticomplementary and 4% were false positive...
  12. ncbi Second generation competitive enzyme immunoassay for detection of bovine antibody to Brucella abortus
    K Nielsen
    Canadian Food Inspection Agency, Ottawa Laboratory Fallowfield, 3851 Fallowfield Road, Ottawa, Ontario, Canada K2H 8P9
    Vet Microbiol 124:173-7. 2007
    ..The performance characteristics, sensitivity, specificity and exclusion of B. abortus S19 vaccinated animals, of the assay were very similar to those of the classical CELISA...
  13. ncbi Detection of ovine antibody to Brucella ovis by indirect enzyme immunoassay
    K Nielsen
    Ottawa Laboratories Fallowfield, Canadian Food Inspection Agency, Ottawa, Ontario, Canada
    J Immunoassay Immunochem 28:243-50. 2007
    ..Because of the batch uniformity of the B. abortus RB51 RLPS and the versatility of the protein A/G-enzyme conjugate, the latter version appears to be the most useful for diagnostic serology...
  14. ncbi Detection of Eschericia coli O157:H7 by fluorescence polarization assay and polymerase chain reaction
    K Nielsen
    Ontario Laboratories Fallowfield, Canadian Food Inspection Agency, Ottawa, Ontario, Canada
    J Immunoassay Immunochem 28:251-65. 2007
    ..5x10(3) CFU per reaction depending on the commercial kits used. The combination of the serological screening FPA and hot-start nested PCR confirmatory assays provided rapid identification of the pathogen...
  15. ncbi Salmonella enterica Serotype Urbana Interference with Brucellosis Serology
    K Nielsen
    Ottawa Laboratories Fallowfield, Canadian Food Inspection Agency, Ottawa, Ontario, Canada
    J Immunoassay Immunochem 28:289-96. 2007
    ..enterocolitica O:9 but all were strongly positive in the FPA using OPS from E. coli O:157 while seven sheep had titers to S. enterica serotype Urbana. The impact on diagnostic serology for brucellosis is discussed...
  16. ncbi Prototype single step lateral flow technology for detection of avian influenza virus and chicken antibody to avian influenza virus
    K Nielsen
    Canadian Food Inspection Agency, Ottawa Laboratories Fallowfield, 3851 Fallowfield Road, Ottawa, Ontario, Canada
    J Immunoassay Immunochem 28:307-18. 2007
    ..Latex beads or colloidal gold particles to which monoclonal anti-chicken antibody was attached, were used as the indicator system...
  17. doi Validation of a second generation competitive enzyme immunoassay (CELISA) for the diagnosis of brucellosis in various species of domestic animals
    K Nielsen
    Canadian Food Inspection Agency, Ontario Laboratories Fallowfield, Ottawa, Ontario, Canada
    Vet Immunol Immunopathol 125:246-50. 2008
    ..Sufficient samples from cattle, swine, sheep and goats to validate the test were included based on OIE guidelines suggesting inclusion of a minimum of 300 positive and 1000 negative samples...
  18. ncbi Development of a lateral flow assay for rapid detection of bovine antibody to Anaplasma marginale
    K Nielsen
    Canadian Food Inspection Agency, Ottawa Laboratory Fallowfield, Ottawa, Ontario, Canada
    J Immunoassay Immunochem 29:10-8. 2008
    ..All samples tested were PCR negative. Of 113 samples from herds with anaplasmosis, 53 were positive in the CELISA and 50 were LFA positive...
  19. ncbi Validation of the fluorescence polarization assay as a serological test for the presumptive diagnosis of porcine brucellosis
    K Nielsen
    Animal Diseases Research Institute, Canadian Food Inspection Agency, Nepean, Ont
    Vet Microbiol 68:245-53. 1999
    ..5 and 97.2%; respectively. It was concluded that the fluorescence polarization assay was a valuable asset to the diagnosis of porcine brucellosis because of its accuracy, ease of performance and relative cost...
  20. pmc Enzyme immunoassays for serological diagnosis of bovine brucellosis: A trial in Latin America
    D Gall
    Canadian Food Inspection Agency, Animal Diseases Research Institute, Nepean, Ontario, Canada K2H 8P9
    Clin Diagn Lab Immunol 5:654-61. 1998
    ....
  21. ncbi Binding of bovine prion protein to heparin: a fluorescence polarization study
    Olga Andrievskaia
    Canadian Food Inspection Agency, OLF Animal Diseases Research Institute, 3851 Fallowfield Road, Ottawa, Canada ON K2H 8P9
    Arch Biochem Biophys 460:10-6. 2007
    ..The dissociation constant of the heparin-brecPrP complex was 73.4+/-3.7 nM. Circular dichroism (CD) experiments indicated that the structure of brecPrP was less helical in the presence of heparin...
  22. ncbi Comparison of serological tests for the detection of ovine and caprine antibody to Brucella melitensis
    K Nielsen
    Canadian Food Inspection Agency, Animal Diseases Research Institute, Ottawa, K2H 8P9 Ontario, Canada
    Rev Sci Tech 23:979-87. 2004
    ..The sensitivity and specificity of the assays relative to the BPAT and CFT positive sera were: IELISA: 99.4% and 98.0%, CELISA: 95.4% and 97.1% and FPA: 92.7% and 99.8%...
  23. ncbi Validation of the fluorescence polarization assay for detection of milk antibody to Brucella abortus
    K Nielsen
    Animal Diseases Research Institute, Canadian Food Inspection Agency, Nepean, Ontario
    J Immunoassay Immunochem 22:203-11. 2001
    ..abortus Sl19 is excluded by the FPA and CELISA but not by the MRT and the IELISA), present in some of the milk samples. The FPA is a homogeneous assay which, unlike the MRT and the IELISA, may be used for testing in the field...
  24. ncbi Use of dried smooth lipopolysaccharide antigen coated polystyrene plates for diagnosis of bovine brucellosis by enzyme immunoassay
    K Nielsen
    Canadian Food Inspection Agency, Animal Diseases Research Institute, Ontario, Canada
    J Immunoassay 19:39-48. 1998
    ..Testing revealed that consistent results were obtained over the test period suggesting that air drying may be a suitable alterative for storage of plates sensitized with some antigens, in particular, smooth lipopolysaccharide...
  25. ncbi A proficiency testing method for detecting antibodies against Brucella abortus in quantitative and qualitative serological tests
    D Gall
    Canadian Food Inspection Agency, Ottawa Fallowfield Laboratory, Brucellosis Centre of Expertise, OIE Reference Laboratory for the Americas, ISO 17025 Accredited, 3851 Fallowfield Road, Ottawa, Ontario K2H 8P9, Canada
    Rev Sci Tech 27:819-28. 2008
    ..The conventional serological tests all passed the panel. Comparing data from both the quantitative and qualitative tests demonstrated that this proficiency testing scheme was fit for the purpose for which it was designed...
  26. ncbi Towards single screening tests for brucellosis
    K Nielsen
    Animal Diseases Research Institute, Canadian Food Inspection Agency, 3851 Fallowfield Rd, Nepean, Ontario, K2H 8P9, Canada
    Rev Sci Tech 24:1027-37. 2005
    ..2%) than from only the OPS, and considerably higher (12.6%) than the CORE. Overall, both the I-ELISA and the FPA with combined antigens were suitable as screening tests for all species of Brucella in the animal species tested...
  27. ncbi Fluorescence polarization immunoassay: detection of antibody to Brucella abortus
    K Nielsen
    Canadian Food Inspection Agency, Animal Diseases Research Institute, 3851 Fallowfield Road, Nepean, Ontario, K2H 8P9, Canada
    Methods 22:71-6. 2000
    ..This technology was applied to the detection of antibody to Brucella abortus in serum and milk, providing for the first time a rapid primary binding assay that is cost effective for use in the field...
  28. ncbi Serological diagnosis of bovine brucellosis: a review of test performance and cost comparison
    D Gall
    Canadian Food Inspection Agency, Animal Diseases Research Institute, Brucellosis Centre of Expertise, Ottawa, Ontario, K2H 8P9, Canada
    Rev Sci Tech 23:989-1002. 2004
    ..In addition, a fee comparison suggested that the primary binding tests were price competitive with conventional tests for the diagnosis of brucellosis and, therefore, had a better combined cost/efficiency rating...
  29. ncbi Fluorescence polarization assay for the diagnosis of brucellosis: a review
    K Nielsen
    Animal Diseases Research Institute, Canadian Food Inspection Agency, Nepean, Ontario
    J Immunoassay Immunochem 22:183-201. 2001
    ....
  30. ncbi Evaluation of the fluorescence polarization assay and comparison to other serological assays for detection of brucellosis in cervids
    D Gall
    Canadian Food Inspection Agency, Animal Diseases Research Institute, Nepean, Ontario
    J Wildl Dis 37:110-8. 2001
    ..in most cases; it is technically simple to do; it is adaptable to field use and it is relatively inexpensive...
  31. ncbi Development of an indirect enzyme-linked immunosorbent assay for detecting equine serum antibodies to the lipopolysaccharide of Salmonella abortusequi
    D Gall
    Canadian Food Inspection Agency, Ottawa Laboratory Fallowfield, Animal Diseases Research Institute, ADRI, Brucella Centre of Expertise, 3851 Fallowfield Road, Ottawa, Ont, Canada K2H 8P9
    Res Vet Sci 81:215-7. 2006
    ..abortusequi LPS as consistently as the IELISA. The data suggests that the IELISA may be a more suitable test for the detection of serum antibodies to S. abortusequi than the TAT...
  32. ncbi Standardization of smooth lipopolysaccharide preparations for use in diagnostic serological tests for bovine antibody Brucella abortus
    K Nielsen
    Canadian Food Inspection Agency, Animal Diseases Research Institute, Nepean, Ontario, Canada
    J Immunoassay 19:239-50. 1998
    ..If data obtained with an antigen preparation, using the same serum dilutions, falls within the range established using two standard deviations, the antigen would be considered acceptable for diagnostic use...
  33. pmc Rapid, field-adapted indirect enzyme-linked immunosorbent assay for detection of antibodies in bovine whole blood and serum to Brucella abortus
    D Gall
    Canadian Food Inspection Agency, Ottawa Laboratory Fallowfield, 3851 Fallowfield Rd, Ottawa, Ontario, Canada K2H 8P9
    Clin Vaccine Immunol 13:501-6. 2006
    ..As a model, this test can be readily extended to other disease applications that use lipopolysaccharide or other stable antigens for the detection of antibodies, such as those to Salmonella spp., Escherichia coli, or Yersinia spp...
  34. pmc Fluorescence polarization assay for detection of Brucella abortus antibodies in bulk tank bovine milk samples
    D Gall
    Canadian Food Inspection Agency, Animal Diseases Research Institute, Ottawa, Ontario K2H 8P9, Canada
    Clin Diagn Lab Immunol 9:1356-60. 2002
    ..Use of this test would make programs for surveillance of dairy animals and eradication of B. abortus more cost-effective...
  35. pmc Review of detection of Brucella spp. by polymerase chain reaction
    Wei Ling Yu
    Ottawa Laboratories Fallowfield, Canadian Food Inspection Agency, 3851 Fallowfield Road, Nepean, Ontario, K2H 8P9, Canada
    Croat Med J 51:306-13. 2010
    ..However, the sensitivity, specificity, and issues of quality control and quality assurance using these methods must be fully validated on clinical samples before PCR can be used in routine laboratory testing for brucellosis...
  36. pmc Identification of a 35-kilodalton serovar-cross-reactive flagellar protein, FlaB, from Leptospira interrogans by N-terminal sequencing, gene cloning, and sequence analysis
    M Lin
    Animal Diseases Research Institute, Nepean, Ontario, Canada
    Infect Immun 65:4355-9. 1997
    ....
  37. ncbi Diagnosis of bovine brucellosis using a homogeneous fluorescence polarization assay
    K Nielsen
    Canadian Food Inspection Agency, Animal Diseases Research Institute, Nepean, Ont, Canada
    Vet Immunol Immunopathol 66:321-9. 1998
    ..In contrast, previous Canadian studies, sensitivity values were 99.0% and 100% and the specificity in both cases was 100%. This discrepancy was probably due to the use of less well characterized sera in the current study...
  38. ncbi Fluorescence polarization assay for the diagnosis of bovine brucellosis: adaptation to field use
    K Nielsen
    Canadian Food Inspection Agency, Animal Diseases Research Institute, 3851 Fallowfield Rd, Nepean, Ontario, Canada K2H 8P9
    Vet Microbiol 80:163-70. 2001
    ..The relative sensitivity and specificity values of the FPA when testing stored whole blood samples were 100% each using a 95mP cut-off.The usefulness of the FPA for testing whole blood samples in the field was demonstrated...
  39. pmc Generation of antibodies against bovine recombinant prion protein in various strains of mice
    Olga Andrievskaia
    Canadian Food Inspection Agency, OLF, 3851 Fallowfield Rd, Ottawa ON K2H 8P9, Canada
    Clin Vaccine Immunol 13:98-105. 2006
    ..This is the first report of the development of anti-PrP MAbs by use of autoimmune NZB/NZW F(1) mice as an alternative approach for the generation of PrP-specific MAbs...
  40. ncbi Comparison of some methods for determing cutoff values for serological assays: a retrospective study using the fluorescence polarization assay
    D Gall
    Canadian Food Inspection Agency, Animal Diseases Research Institute, Ontario
    J Immunoassay Immunochem 22:85-98. 2001
    ..21% to 99.58%). However, the Receiver Operating Characteristic analysis was considered more suitable, due to the ease of data manipulation and computer analysis, providing flexibility for different field applications...
  41. ncbi Evaluation of culture enrichment procedures for use with Salmonella detection immunoassay
    H Huang
    Animal Diseases Research Institute, Canadian Food Inspection Agency, Nepean, Ontario
    Int J Food Microbiol 51:85-94. 1999
    ....
  42. ncbi Fluorescence polarization assay for diagnosis of human brucellosis
    Nidia E Lucero
    Brucellosis Laboratory, Administracion Nacional de Laboratorios e Institutos de Salud Dr C G Malbran, Avda Velez Sarsfield 563, 1281 Buenos Aires, Argentina
    J Med Microbiol 52:883-7. 2003
    ..abortus, B. melitensis and B. suis and for identifying patients suffering relapses. Because of the ease of the procedure, it could be readily adopted for use in clinical laboratories and blood banks...