Bovine tuberculosis (BTB) is a significant and intractable disease of cattle caused by Mycobacterium bovis. In the UK, despite an aggressive eradication programme, the prevalence of BTB is increasing with an unexplained, exponential rise in cases year on year. Here we show in a study involving 3026 dairy herds in England and Wales that there is a significant negative association between exposure to the common, ubiquitous helminth parasite, Fasciola hepatica and diagnosis of BTB. The magnitude of the single intradermal comparative cervical tuberculin test used to diagnose BTB is reduced in cattle experimentally co-infected with M. bovis and F. hepatica. We estimate an under-ascertainment rate of about one-third (95% Confidence Intervals 27-38%) among our study farms, in the hypothetical situation of no exposure to F. hepatica. This finding may in part explain the continuing spread of BTB and the failure of the current eradication programme in the UK.

An international committee of Johne's disease (JD) researchers was convened to develop guidelines for JD challenge studies in multiple animal species. The intent was to develop and propose international standard guidelines for models based on animal species that would gain acceptance worldwide. Parameters essential for the development of long-term and short-term infection models were outlined and harmonized to provide a ''best fit'' JD challenge model for cattle, goats, sheep, cervids, and mice. These models will be useful to study host-pathogen interactions, host immunity at the local and systemic level, and for evaluating vaccine candidates and therapeutics. The consensus guidelines herein list by animal species strains of Mycobacterium avium subsp. paratuberculosis used, challenge dose, dose frequency, age of challenge, route of challenge, preparation of inoculum, experimental animal selection, quality control, minimal experimental endpoints and other parameters. #

Therefore, the development and maintenance of a Th1 IFN-c response is associated with a greater control of M. bovis infection. Animals progressing from a Th1-biased to a Th0-biased immune response developed more extensive pathology and performed less well in CMI-based diagnostic tests but developed strong IgG1 humoral responses.

Bovine tuberculosis persists as a costly zoonotic disease in numerous countries despite extensive eradication and control efforts. Sequential serum samples obtained from Mycobacterium bovis-infected cattle were evaluated for seroreactivity to mycobacterial antigens. Animals received M. bovis by aerosol, intratonsil, intranasal, or intratracheal inoculation. Assays included the multiantigen print immunoassay for determination of antigen recognition patterns, immunoblot analysis for sensitive kinetic studies, and the VetTB STAT-PAK test, a novel, rapid test based on lateral-flow technology. Responses to MPB83 were detected for all M. bovis-infected animals regardless of the route or strain of M. bovis used for inoculation. Other less commonly recognized antigens included ESAT-6, CFP-10, and MPB70. Responses to MPB83 were detectable as early as 4 weeks after inoculation, were boosted upon injection of purified protein derivatives for skin testing, and persisted throughout the course of each of the four challenge studies. MPB83-specific immunoglobulin M (IgM) was detected prior to MPB83-specific IgG detection; however, early IgM responses rapidly waned, suggesting a benefit of tests that detect both IgM-and IgG-specific antibodies. The VetTB STAT-PAK test detected responses in sera from 60% (15/25) of the animals by 7 weeks after challenge and detected responses in 96% (24/25) of the animals by 18 weeks. These findings demonstrate the potential for new-generation antibody-based tests for the early detection of M. bovis infection in cattle.Tuberculosis (TB) in humans may result from exposure to any one of the tubercle bacilli included within the Mycobacterium tuberculosis complex (i.e., M. tuberculosis, M. bovis, M. africanum, M. pinnipedii, and M. microti). Mycobacterium bovis, unlike M. tuberculosis, has a wide host range, is the species most often isolated from tuberculous cattle, and has several wildlife maintenance hosts, including the Eurasian badger (Meles meles), brush-tailed possum (Trichosurus vulpecula), and white-tailed deer (Odocoileus virginianus). Wildlife reservoirs have made M. bovis eradication from national herds in several developed countries, including the United Kingdom, New Zealand, and the United States, particularly difficult (3, 4, 16). Eradication campaigns in these countries have generally relied on test and removal, slaughterhouse surveillance, movement restriction, and/or wildlife reservoir control strategies. The tests most widely used for the detection of TB in humans and cattle include the measurement of delayed-type hypersensitivity (i.e., skin testing) to purified protein derivatives (PPDs) and/or in vitro assays for gamma interferon produced in response to mycobacterial antigen stimulation (i.e., Bovigam [Prionics AG, Schlieren, Switzerland] and Quantiferon Gold [Cellestis Inc., Carnegie, Victoria, Australia]). These tests rely on early cell-mediated responses, a hallmark of TB immunopathogenesis. In contrast, the poor sensitivity of antibodybased tests has prevented the widespre...