Optimising and Evaluating the Characteristics of a Multiple Antigen ELISA for Detection of Mycobacterium bovis Infection in a Badger Vaccine Field Trial

I. Aznar, K. Frankena, S.J. More, C. Whelan, W. Martin, E. Gormley, L.A.L. Corner, D. Murphy, M.C.M. de Jong

Research output: Contribution to journalArticleAcademicpeer-review

5 Citations (Scopus)

Abstract

A long-term research programme has been underway in Ireland to evaluate the usefulness of badger vaccination as part of the national bTB (bovine tuberculosis) control strategy. This culminated in a field trial which commenced in county Kilkenny in 2009 to determine the effects of badger vaccination on Mycobacterium bovis transmission in badgers under field conditions. In the present study, we sought to optimise the characteristics of a multiplex chemiluminescent assay for detection of M. bovis infection in live badgers. Our goal was to maximise specificity, and therefore statistical power, during evaluation of the badger vaccine trial data. In addition, we also aimed to explore the effects of vaccination on test characteristics. For the test optimisation, we ran a stepwise logistic regression with analytical weights on the converted Relative Light Units (RLU) obtained from testing blood samples from 215 badgers captured as part of culling operations by the national Department of Agriculture, Food and the Marine (DAFM). The optimised test was applied to two other datasets obtained from two captive badger studies (Study 1 and Study 2), and the sensitivity and specificity of the test was attained separately for vaccinated and non-vaccinated badgers. During optimisation, test sensitivity was maximised (30.77%), while retaining specificity at 99.99%. When the optimised test was then applied to the captive badger studies data, we observed that test characteristics did not vary greatly between vaccinated and non-vaccinated badgers. However, a different time lag between infection and a positive test result was observed in vaccinated and non-vaccinated badgers. We propose that the optimized multiplex immunoassay be used to analyse the vaccine trial data. In relation to the difference in the time lag observed for vaccinated and non-vaccinated badgers, we also present a strategy to enable the test to be used during trial evaluation.
Original languageEnglish
Article numbere100139
JournalPLoS ONE
Volume9
Issue number7
DOIs
Publication statusPublished - 2014

Fingerprint

Mustelidae
Mycobacterium Infections
badgers
Mycobacterium bovis
field experimentation
Vaccines
Enzyme-Linked Immunosorbent Assay
enzyme-linked immunosorbent assay
vaccines
antigens
Antigens
infection
Agriculture
Logistics
Assays
Blood
testing
Testing
Vaccination
vaccination

Keywords

  • gamma-interferon assay
  • meles-meles
  • endobronchial inoculation
  • experimental tuberculosis
  • protective immunity
  • cattle herds
  • bcg
  • sensitivity
  • challenge
  • pathology

Cite this

@article{3f9261be0e414e9182e26c257a943fcb,
title = "Optimising and Evaluating the Characteristics of a Multiple Antigen ELISA for Detection of Mycobacterium bovis Infection in a Badger Vaccine Field Trial",
abstract = "A long-term research programme has been underway in Ireland to evaluate the usefulness of badger vaccination as part of the national bTB (bovine tuberculosis) control strategy. This culminated in a field trial which commenced in county Kilkenny in 2009 to determine the effects of badger vaccination on Mycobacterium bovis transmission in badgers under field conditions. In the present study, we sought to optimise the characteristics of a multiplex chemiluminescent assay for detection of M. bovis infection in live badgers. Our goal was to maximise specificity, and therefore statistical power, during evaluation of the badger vaccine trial data. In addition, we also aimed to explore the effects of vaccination on test characteristics. For the test optimisation, we ran a stepwise logistic regression with analytical weights on the converted Relative Light Units (RLU) obtained from testing blood samples from 215 badgers captured as part of culling operations by the national Department of Agriculture, Food and the Marine (DAFM). The optimised test was applied to two other datasets obtained from two captive badger studies (Study 1 and Study 2), and the sensitivity and specificity of the test was attained separately for vaccinated and non-vaccinated badgers. During optimisation, test sensitivity was maximised (30.77{\%}), while retaining specificity at 99.99{\%}. When the optimised test was then applied to the captive badger studies data, we observed that test characteristics did not vary greatly between vaccinated and non-vaccinated badgers. However, a different time lag between infection and a positive test result was observed in vaccinated and non-vaccinated badgers. We propose that the optimized multiplex immunoassay be used to analyse the vaccine trial data. In relation to the difference in the time lag observed for vaccinated and non-vaccinated badgers, we also present a strategy to enable the test to be used during trial evaluation.",
keywords = "gamma-interferon assay, meles-meles, endobronchial inoculation, experimental tuberculosis, protective immunity, cattle herds, bcg, sensitivity, challenge, pathology",
author = "I. Aznar and K. Frankena and S.J. More and C. Whelan and W. Martin and E. Gormley and L.A.L. Corner and D. Murphy and {de Jong}, M.C.M.",
year = "2014",
doi = "10.1371/journal.pone.0100139",
language = "English",
volume = "9",
journal = "PLoS ONE",
issn = "1932-6203",
publisher = "Public Library of Science",
number = "7",

}

Optimising and Evaluating the Characteristics of a Multiple Antigen ELISA for Detection of Mycobacterium bovis Infection in a Badger Vaccine Field Trial. / Aznar, I.; Frankena, K.; More, S.J.; Whelan, C.; Martin, W.; Gormley, E.; Corner, L.A.L.; Murphy, D.; de Jong, M.C.M.

In: PLoS ONE, Vol. 9, No. 7, e100139, 2014.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - Optimising and Evaluating the Characteristics of a Multiple Antigen ELISA for Detection of Mycobacterium bovis Infection in a Badger Vaccine Field Trial

AU - Aznar, I.

AU - Frankena, K.

AU - More, S.J.

AU - Whelan, C.

AU - Martin, W.

AU - Gormley, E.

AU - Corner, L.A.L.

AU - Murphy, D.

AU - de Jong, M.C.M.

PY - 2014

Y1 - 2014

N2 - A long-term research programme has been underway in Ireland to evaluate the usefulness of badger vaccination as part of the national bTB (bovine tuberculosis) control strategy. This culminated in a field trial which commenced in county Kilkenny in 2009 to determine the effects of badger vaccination on Mycobacterium bovis transmission in badgers under field conditions. In the present study, we sought to optimise the characteristics of a multiplex chemiluminescent assay for detection of M. bovis infection in live badgers. Our goal was to maximise specificity, and therefore statistical power, during evaluation of the badger vaccine trial data. In addition, we also aimed to explore the effects of vaccination on test characteristics. For the test optimisation, we ran a stepwise logistic regression with analytical weights on the converted Relative Light Units (RLU) obtained from testing blood samples from 215 badgers captured as part of culling operations by the national Department of Agriculture, Food and the Marine (DAFM). The optimised test was applied to two other datasets obtained from two captive badger studies (Study 1 and Study 2), and the sensitivity and specificity of the test was attained separately for vaccinated and non-vaccinated badgers. During optimisation, test sensitivity was maximised (30.77%), while retaining specificity at 99.99%. When the optimised test was then applied to the captive badger studies data, we observed that test characteristics did not vary greatly between vaccinated and non-vaccinated badgers. However, a different time lag between infection and a positive test result was observed in vaccinated and non-vaccinated badgers. We propose that the optimized multiplex immunoassay be used to analyse the vaccine trial data. In relation to the difference in the time lag observed for vaccinated and non-vaccinated badgers, we also present a strategy to enable the test to be used during trial evaluation.

AB - A long-term research programme has been underway in Ireland to evaluate the usefulness of badger vaccination as part of the national bTB (bovine tuberculosis) control strategy. This culminated in a field trial which commenced in county Kilkenny in 2009 to determine the effects of badger vaccination on Mycobacterium bovis transmission in badgers under field conditions. In the present study, we sought to optimise the characteristics of a multiplex chemiluminescent assay for detection of M. bovis infection in live badgers. Our goal was to maximise specificity, and therefore statistical power, during evaluation of the badger vaccine trial data. In addition, we also aimed to explore the effects of vaccination on test characteristics. For the test optimisation, we ran a stepwise logistic regression with analytical weights on the converted Relative Light Units (RLU) obtained from testing blood samples from 215 badgers captured as part of culling operations by the national Department of Agriculture, Food and the Marine (DAFM). The optimised test was applied to two other datasets obtained from two captive badger studies (Study 1 and Study 2), and the sensitivity and specificity of the test was attained separately for vaccinated and non-vaccinated badgers. During optimisation, test sensitivity was maximised (30.77%), while retaining specificity at 99.99%. When the optimised test was then applied to the captive badger studies data, we observed that test characteristics did not vary greatly between vaccinated and non-vaccinated badgers. However, a different time lag between infection and a positive test result was observed in vaccinated and non-vaccinated badgers. We propose that the optimized multiplex immunoassay be used to analyse the vaccine trial data. In relation to the difference in the time lag observed for vaccinated and non-vaccinated badgers, we also present a strategy to enable the test to be used during trial evaluation.

KW - gamma-interferon assay

KW - meles-meles

KW - endobronchial inoculation

KW - experimental tuberculosis

KW - protective immunity

KW - cattle herds

KW - bcg

KW - sensitivity

KW - challenge

KW - pathology

U2 - 10.1371/journal.pone.0100139

DO - 10.1371/journal.pone.0100139

M3 - Article

VL - 9

JO - PLoS ONE

JF - PLoS ONE

SN - 1932-6203

IS - 7

M1 - e100139

ER -