Numerous species of mammals are susceptible to
Mycobacterium bovis, the causative agent of bovine tuberculosis (TB). Several wildlife hosts have emerged as reservoirs of
M. bovis infection for ...domestic livestock in different countries. In the present study, blood samples were collected from Eurasian badgers (
n
=
1532), white-tailed deer (
n
=
463), brushtail possums (
n
=
129), and wild boar (
n
=
177) for evaluation of antibody responses to
M. bovis infection by a lateral-flow rapid test (RT) and multiantigen print immunoassay (MAPIA). Magnitude of the antibody responses and antigen recognition patterns varied among the animals as determined by MAPIA; however, MPB83 was the most commonly recognized antigen for each host studied. Other seroreactive antigens included ESAT-6, CFP10, and MPB70. The agreement of the RT with culture results varied from 74% for possums to 81% for badgers to 90% for wild boar to 97% for white-tailed deer. Small numbers of wild boar and deer exposed to
M. avium infection or paratuberculosis, respectively, did not cross-react in the RT, supporting the high specificity of the assay. In deer, whole blood samples reacted similarly to corresponding serum specimens (97% concordance), demonstrating the potential for field application. As previously demonstrated for badgers and deer, antibody responses to
M. bovis infection in wild boar were positively associated with advanced disease. Together, these findings suggest that a rapid TB assay such as the RT may provide a useful screening tool for certain wildlife species that may be implicated in the maintenance and transmission of
M. bovis infection to domestic livestock.
Existing strategies for long-term bovine tuberculosis (bTB) control/eradication campaigns are being reconsidered in many countries because of the development of new testing technologies, increased ...global trade, continued struggle with wildlife reservoirs of bTB, redistribution of international trading partners/agreements, and emerging financial and animal welfare constraints on herd depopulation. Changes under consideration or newly implemented include additional control measures to limit risks with imported animals, enhanced programs to mitigate wildlife reservoir risks, re-evaluation of options to manage bTB-affected herds/regions, modernization of regulatory framework(s) to re-focus control efforts, and consideration of emerging testing technologies (i.e. improved or new tests) for use in bTB control/eradication programs. Traditional slaughter surveillance and test/removal strategies will likely be augmented by incorporation of new technologies and more targeted control efforts. The present review provides an overview of current and emerging bTB testing strategies/tools and a vision for incorporation of emerging technologies into the current control/eradication programs.
Tuberculosis infections caused by
Mycobacterium (
M.)
pinnipedii in a South American sea lion, Bactrian camel, and Malayan tapirs kept in two zoological gardens spanning a time period of 5 years are ...reported. The zoos were linked by the transfer of one tapir. Conventional bacteriological and molecular methods were applied to detect the pathogen. Spoligotyping and MIRU/VNTR-typing performed to assess the genetic similarity revealed identical molecular characteristics of the isolates from all animals involved. Anti-tuberculosis antibodies were detected using ELISA and a recently developed serological rapid test. The study shows that: (i) using molecular methods, the assessment of the genetic relationship of infectious agents helps to confirm the routes of infection, and that (ii) immunological tests may help to detect tuberculosis infections
ante mortem more reliably and early. This would prevent the transfer of tuberculosis by asymptomatic animals.
•We explored several serological rapid immunochromatographic and ELISA tests for detection of antibodies against the Mycobacterium tuberculosis complex in wild boar piglets.•Sensitivity was assessed ...using tuberculosis compatible lesions and Mycobacterium tuberculosis complex culture in naturally infected wild boar piglets.•Rapid animal-side tests can contribute to TB control strategies by enabling the setup of test and cull schemes or improving pre-movement testing.•However, sub-optimal test performance in piglets as compared to that in older wild boar should be taken into account.
Animal tuberculosis (TB) caused by infection with Mycobacterium bovis and closely related members of the M. tuberculosis complex (MTC), is often reported in the Eurasian wild boar (Sus scrofa). Tests detecting antibodies against MTC antigens are valuable tools for TB monitoring and control in suids. However, only limited knowledge exists on serology test performance in 2–6 month-old piglets. In this age-class, recent infections might cause lower antibody levels and lower test sensitivity. We examined 126 wild boar piglets from a TB-endemic site using 6 antibody detection tests in order to assess test performance. Bacterial culture (n=53) yielded a M. bovis infection prevalence of 33.9%, while serum antibody prevalence estimated by different tests ranged from 19% to 38%, reaching sensitivities between 15.4% and 46.2% for plate ELISAs and between 61.5% and 69.2% for rapid immunochromatographic tests based on dual path platform (DPP) technology. The Cohen kappa coefficient of agreement between DPP WTB (Wildlife TB) assay and culture results was moderate (0.45) and all other serological tests used had poor to fair agreements. This survey revealed the ability of several tests for detecting serum antibodies against the MTC antigens in 2–6 month-old naturally infected wild boar piglets. The best performance was demonstrated for DPP tests. The results confirmed our initial hypothesis of a lower sensitivity of serology for detecting M. bovis-infected piglets, as compared to older wild boar. Certain tests, notably the rapid animal-side tests, can contribute to TB control strategies by enabling the setup of test and cull schemes or improving pre-movement testing. However, sub-optimal test performance in piglets as compared to that in older wild boar should be taken into account.
This report describes how Mycobacterium bovis infection was controlled and eventually eradicated in a farmed red deer herd in the north of England, following sustained tuberculin skin testing ...supplemented with serological (antibody) tests over a period of approximately two years. By taking advantage of the anamnestic antibody response produced by the skin test to detect skin test‐negative, antibody‐positive infected individuals, a total of 35 additional animals were identified, including 2 with gross visible lesions typical of bovine tuberculosis (BTB). Without detection and removal, these animals would have posed a continued risk of BTB persistence within the herd and potentially contributed to the spread of infection from deer into wildlife and surrounding cattle farms in an area of low BTB incidence. This case supports the use of ancillary diagnostic serological tests to speed up the resolution of incidents of BTB caused by M bovis in captive deer herds.
Over the past two decades, highly virulent strains of Mycobacterium tuberculosis have emerged and spread rapidly in man, suggesting a selective advantage based on virulence. A similar scenario has ...not been described for Mycobacterium bovis infection in cattle (i.e. bovine tuberculosis). An epidemiological investigation of a recent outbreak of bovine tuberculosis in a USA dairy indicated that the causative strain of M. bovis (strain 10-7428) was particularly virulent, with rapid spread within the herd. In the present study, the virulence of this strain (10-7428) was directly compared in the target host with a well-characterized strain (95-1315) of relevance to the USA bovine tuberculosis eradication programme. Aerosol inoculation of 104 colony forming units of M. bovis 95-1315 (n = 8) or 10-7428 (n = 8) resulted in a similar distribution and severity of gross and microscopical lesions of tuberculosis as well as mycobacterial colonization, primarily affecting the lungs and lung-associated lymph nodes. Specific cell-mediated and antibody responses, including kinetics of the response, as well as antigen recognition profiles, were also comparable between the two treatment groups. Present findings demonstrate that M. bovis strains 95-1315 and 10-7428 have similar virulence when administered to cattle via aerosol inoculation. Other factors such as livestock management practices likely affected the severity of the outbreak in the dairy.
Serological diagnosis of infectious diseases that generate a highly heterogeneous antibody repertoire, such as tuberculosis, requires tests based on cocktails of antigens. We describe a new method ...called multi-antigen print immunoassay (MAPIA) for cocktail-based serological diagnosis. The assay entails the application of antigen to nitrocellulose membranes by micro-aerosolization (printing), followed by antibody detection using standard chromogenic immunodevelopment. Cocktails of protein antigens of
Mycobacterium tuberculosis tested by MAPIA were found to maintain the serological activity of each of their components. In contrast, the same cocktails tested by enzyme-linked immunosorbent assay (ELISA) had a serological activity that was lower than the sum of the activities of their components. Consequently, cocktail-based MAPIA attained the diagnostic sensitivity expected on the basis of single antigen results, while a significant loss of diagnostic sensitivity was observed with cocktail-based ELISA. Thus, the MAPIA format is superior to conventional ELISA for the serological diagnosis of infectious diseases characterized by heterogeneous antibody responses.
A recent outbreak of tuberculosis (TB) in a dromedary racing herd of 58 animals involved 3 infected animals. Disease was confirmed at necropsy by finding gross lesions from which
Mycobacterium bovis ...(antelope type) was isolated. Sera collected from the camels in this herd were used to evaluate two new serological methods, Multiantigen Print Immunoassay (MAPIA) and rapid test (RT) developed using the lateral-flow technology, in comparison with the intradermal tuberculin tests. Antibodies were found in all three infected dromedaries by both RT and MAPIA, but not in the remaining 55 animals in the herd. With the limited number of animals tested in this study, the serological assays showed the potential for convenient, rapid, and accurate diagnosis of TB in live camels.
Antibody responses in New World camelids (NWC) infected with
Mycobacterium microti were studied by two serological methods, multiantigen print immunoassay (MAPIA) and lateral-flow-based rapid test ...(RT). Serum samples were collected during 2004–2006 from 87 animals including 1 alpaca and 7 llamas with confirmed or suspected
M. microti infection, 33 potentially exposed but clinically healthy animals from known infected herds, and 46 control NWC from herds where infection had not been previously diagnosed. The serological assays correctly identified infection status in 97% (MAPIA) or 87% (RT) cases. In three llamas with confirmed
M. microti infection and one llama with gross pathology suggestive of disease, for which multiple serum samples collected over time were available, the antibody-based tests showed positive results 1–2 years prior to the onset of clinical signs or being found dead. In MAPIA, MPB83 protein was identified to be an immunodominant serological target antigen recognized in NWC infected with
M. microti. With the limited number of animals tested in this study, the serological assays demonstrated the potential for convenient, rapid, and accurate diagnosis of
M. microti infection in live llamas and alpacas.
PDF
