Use of a multiplex enzyme-linked immunosorbent assay to detect a subpopulation of Mycobacterium bovis–infected animals deemed negative or inconclusive by the single intradermal comparative tuberculin skin test

Abstract

Abstract. Although the single intradermal comparative tuberculin skin test (SICTT) remains the most effective assay for detecting cattle infected with Mycobacterium bovis, not all infected animals are detected with the SICTT. This has made it difficult to control bovine tuberculosis using a single assay. Use of the gamma interferon assay in conjunction with the SICTT has improved the level of detection but some infected animals still go undetected. This could be in part attributable to both assays being reliant on a cell-mediated immune response. The present study was undertaken to determine if a multiplex assay can improve the level of detection of infected animals when used in combination with the SICTT. The Enferplex TB assay is a multi-antigen ELISA designed for the detection of antibody in animals at different stages of infection and disease. Sixty cattle that were confirmed by histopathology and/or culture to be infected with M. bovis and that were SICTT negative (43.3%) or difficult to evaluate (56.7% inconclusive) were used in the study. Fifty-three (88.3%) of the animals were positive in multiplex ELISA. The results show that the level of detection of M. bovis-infected animals can be improved by the combined use of the SICTT and the multiplex ELISA.

Serological Analysis of Tuberculosis in Goats by Use of the Enferplex Caprine TB Multiplex Test

“…Nevertheless, a large number of studies have documented correlations between antibodies and TB lesions and/or bacterial loads in cattle and other species (13,14,17,28,31,33,34,37,44,45). The Enferplex test has previously been shown to detect infected cattle with lesions that were missed by the SICTT (17). These studies thus present supporting evidence that antibodies generally act as a surrogate marker of infection.…”

“…The test has been used previously to help manage a goat breakdown herd by identifying infected animals that were not detected by the SICTT (22). In cattle, the multiplex has been shown to detect a substantial proportion of animals with lesions that were negative or inconclusive by the SICTT (17). These studies suggest that the multiplex test does indeed identify infected animals missed by skin tests.…”

“…paratuberculosis vaccination. Serological testing has been shown in a few studies to detect infection that CMI tests have missed (2,17,20), though the usefulness of applying such antibody tests in the management of TB infection has not been investigated to any great extent.…”

“…Also, the presence of antibody provides only indirect evidence of TB infection in skin testnegative goats that did not undergo postmortem examination. Nevertheless, a large number of studies have documented correlations between antibodies and TB lesions and/or bacterial loads in cattle and other species (13,14,17,28,31,33,34,37,44,45). The Enferplex test has previously been shown to detect infected cattle with lesions that were missed by the SICTT (17).…”

“…In previous work, we have described the development of multiplex serology tests by using antigen arrays to detect antibodies to specific M. bovis antigens in several species, including cattle, goats, and alpacas (15)(16)(17)(18)(19)(20)(21). The sensitivities and specificities obtained with these serology tests varied with the population under study.…”