The Performance of Three Immune Assays to Assess the Serological Status of Cattle Experimentally Exposed to Mycoplasma bovis

Abstract

<i>Mycoplasma bovis</i> is associated with several clinical syndromes of cattle. Currently, limited information is available on the sensitivity (<i>Se</i>) and specificity (<i>Sp</i>) of serological assays used for the detection of <i>M. bovis</i>-specific antibodies. Consequently, it is difficult to critically evaluate the outcomes of studies that use these assays. Therefore, the current study used bovine sera sourced from <i>M. bovis</i> exposure studies from three countries to estimate the <i>Se</i> and <i>Sp</i> of two commercial <i>M. bovis</i> enzyme-linked immunosorbent assays (ELISA), BIO K302 and BIO K260, and Western blotting. Western blotting had the highest <i>Se</i> estimate of 74% (95% confidence interval (CI): 16-98%), compared to the BIO K302: 47% (95% CI: 10-87%) and BIO K260: 28% (95% CI: 1-92%). However, for <i>Sp,</i> the BIO K302: 96% (95% CI: 87-99%) and the BIO K260: 100% (95% CI: 93-100%) out-performed Western blotting: 88% (95% CI: 56-98%). Western blotting was the best assay for detecting seroconversion, correctly identifying 61% (95% CI: 29-86%) of exposed animals compared to 35% for BIO K302 (95% CI: 21-54%) and 8% for BIO K260 (95% CI: 0-87%). While none of the methods assessed had high <i>Se</i> and <i>Sp</i>, the availability of these estimates will aid in the interpretation of studies that use these assays. The results of this study highlight the difficulties encountered when using serology to detect exposure to <i>M. bovis</i> in cattle.