Zoonotic tuberculosis. A comprehensive ONE HEALTH approach.

The objective of this report is to provide information on Mycobacterium tuberculosis complex infections in animals and in humans. Included is information on the susceptibility of different species as well as information on etiology, epidemiology, pathogenesis, diagnosis, prevention and control of this disease. The term One Health has been adopted to describe the unified human medical and veterinary interdisciplinary/multidisciplinary collaborative approach to zoonoses and will be critical for future endeavors in the control of the global TB epidemic. This unified paradigm is ideally suited for control of bovine TB and many other international public health and clinical health issues. Sharing resources and increasing interaction between public health and veterinary medical scientists can raise awareness of 'shared risk' of bovine TB between humans and animals and, in resource-limited situations, can maximize use of existing infrastructure and reduce unnecessary duplication of effort in disease control programs.

Short communication: Survival of Mycobacterium avium ssp. paratuberculosis in tissues of cows following low-dose exposure to electron beam irradiation.

This investigation was designed to determine the effects of low-dose electron beam irradiation on the survival of Mycobacterium avium ssp. paratuberculosis in tissue samples collected at necropsy from clinically affected cows. Mycobacterium avium ssp. paratuberculosis was isolated from the ileum and ileocecal valve of one cow and from the ileum of another cow irradiated at 4.0 kGy, but was not isolated from the ileum, ileocecal valve, or mesenteric lymph node of 11 other cows irradiated at 4 kGy.

Zoonotic tuberculosis: A comprehensive one health approach

The objective of this report is to provide information on Mycobacterium tuberculosis complex infections in animals and in humans. Included is information on the susceptibility of different species as well as information on etiology, epidemiology, pathogenesis, diagnosis, prevention and control of this disease. The term One Health has been adopted to describe the unified human medical and veterinary interdisciplinary/multidisciplinary collaborative approach to zoonoses and will be critical for future endeavors in the control of the global TB epidemic. This unified paradigm is ideally suited for control of bovine TB and many other international public health and clinical health issues. Sharing resources and increasing interaction between public health and veterinary medical scientists can raise awareness of ‘shared risk' of bovine TB between humans and animals and, in resource-limited situations, can maximize use of existing infrastructure and reduce unnecessary duplication of effort in disease control programs.

El objetivo de este artículo es proporcionar información sobre las infecciones por el Complejo Mycobacterium tuberculosis en animales y en humanos. Se incluye información sobre la susceptibilidad de diferentes especies, así como sobre la etiología, epidemiología, patogenia, diagnóstico, prevención y control de esta enfermedad. La expresión UNA SALUD ha sido adoptada para describir el enfoque unificado de la medicina humana y la veterinaria, de colaboración interdisciplinaria/multidisciplinaria en las zoonosis, que puede resultar fundamental para el control de la endemia mundial de tuberculosis. Este paradigma unificado es especialmente relevante para el control de la tuberculosis bovina. Compartir recursos y lograr una mayor interacción entre la investigación en salud pública y en medicina veterinaria puede elevar la conciencia de “riesgo compartido” de la tuberculosis bovina en humanos y animales y, en situaciones de recursos limitados, puede maximizar el uso de la infraestructura existente y reducir la duplicación innecesaria de esfuerzos en los programas de control de la infección y enfermedad.

Composition and Potency Characterization of Mycobacterium avium subsp. paratuberculosis Purified Protein Derivatives.

Mycobacterium avium subsp. paratuberculosis (MAP) purified protein derivatives (PPDs) are immunologic reagents prepared from cultured filtrates of the type strain. Traditional production consists of floating culture incubation at 37°C, organism inactivation by autoclaving, coarse filtration, and protein precipitation. Three traditional production PPDs were used in this study including lot 9801, which served as a reference and has been used in the field for decades. Alternative production PPDs (0902A and 0902B), in which the autoclaving step was removed, were also analyzed in this study. SDS-PAGE analysis revealed protein smearing in traditional PPDs, but distinct bands were observed in the alternative PPD preparations. Antibody bound distinct protein bands in the alternative PPDs by immunoblot analysis, whereas an immunoreactive smear was observed with the traditional PPDs. Mass spectrometry identified 194 proteins among three PPD lots representing the two different production methods, ten of which were present in all PPDs examined. Selected proteins identified by mass spectrometry were recombinantly expressed and purified from E. coli and evaluated by the guinea pig potency test. Seven recombinant proteins showed greater erythema as compared to the reference PPD lot 9801 in paired guinea pigs and were able to stimulate interferon-gamma production in blood from Johne's positive animals. These results suggest that autoclaving culture suspensions is not a necessary step in PPD production and specific proteins could supplant the PPD antigen for intradermal skin testing procedures and for use as in-vitro assay reagents.

Preventing and controlling zoonotic tuberculosis: a One Health approach.

The expression One Health refers to the unified human and veterinary approach to zoonoses, an approach that used to be identified with Medicine throughout the 20th Century. Zoonotic tuberculosis (TB), a disease due to bacteria of the Mycobacterium tuberculosis complex, is a recognized global public veterinary health problem. The significance of the health and economic threats posed by zoonotic TB has been recognized by several global health agencies, which have called for control and eradication programs for zoonotic TB. The interplay between humans, livestock, wildlife, and ecology in the epidemiology of zoonotic TB make arduous the control of the disease, as such zoonotic TB is the ideal target for the application of the One Health approach. This article argues that a successful One Health response to TB will consider the effects of disease on socio-economic well-being, and allow for addressing the social, cultural and economic conditions that facilitate spread and maintenance of this disease. The One Health approach will also enable the development of disease control programs involving both animal and human populations, fostering the participation of various stakeholders. One Health approach will also allow for expanding scientific knowledge, improve medical education and clinical care, and develop effective disease control programs for both human and animal populations.

Evaluation of the cell-mediated immune response to reduced doses of Mycobacterium avium ssp. paratuberculosis vaccine in cattle.

Vaccination against Johne's disease with an inactivated, oil-adjuvanted Mycobacterium avium ssp. paratuberculosis (MAP) bacterin can reduce clinical signs in infected herds; however, the development of indurated swelling at the injection site limits vaccine acceptability to producers. This study determined whether a reduced dose of vaccine antigen, with a full dose of adjuvant, would produce comparable T cell-mediated immune responses with smaller lesions. T cell responses induced by in vitro stimulation with MAP antigen from calves vaccinated with full, half, and quarter doses of antigen were evaluated 2, 4, and 9 months after vaccination by multi-parameter flow cytometry (FCM) and the whole blood interferon-gamma (WB IFN-gamma) assay. The WB IFN-gamma responses were significantly elevated in vaccinated animals, but did not differ significantly between doses. FCM demonstrated antigen-specific responses for both IFN-gamma and IL-4 in the CD4 T cell population from vaccinated animals, while CD8 T cells and gammadelta T cells mainly responded with increased IFN-gamma. Dose may have affected some T cell subset parameters at some time points, but intradermal skin test responses, WB IFN-gamma production, IFN-gamma responses by T cell subsets in FCM were not significantly different between full, half, or quarter doses of antigen. Injection site lesions were smaller in animals vaccinated with a lower dose of antigen, but reached statistical significance (P<0.05) in the half dose group only.

Tuberculosis: a re-emerging disease in animals and humans.

Tuberculosis continues to be an important disease both in humans and animals. It causes morbidity, mortality and economic loss worldwide. The occurrence of Mycobacterium bovis disease in humans, domesticated and wild animals confirms the relevance of this zoonosis. M. bovis in humans continues to be reported in industrialised countries and in immigrants from regions of the world where tuberculosis in cattle is endemic. The real incidence of M. bovis in humans in developing countries continues to be roughly under-estimated due to the scarcity of appropriate laboratory facilities to isolate and to differentiate M. bovis strains. In Latin America, less than 1% of tuberculosis cases are reported as being due to M. bovis. However, the economic relevance that meat and dairy industries play in these countries stimulates the promotion of bovine tuberculosis eradication programmes. Human-to-human airborne transmission of M. bovis does occur and it may be important where human immunodeficiency virus (HIV) infection in humans is prevalent, M. bovis infection in cattle is enzootic and pasteurisation of dairy products is not routinely practised. Eradication of M. bovis in cattle and pasteurisation of dairy products are the cornerstones of prevention of human disease. Measures should be developed to identify and control M. bovis infection in wild animals as these may be important reservoirs of infection for domesticated food-producing animals. There is a need for medical and veterinary professionals to cooperate on disease outbreaks. The information presented herein strongly supports the 'One World/One Health/One Medicine' concept.

Monitoring responses by use of five-color flow cytometry in subsets of peripheral T cells obtained from cattle inoculated with a killed Mycobacterium avium subsp paratuberculosis vaccine.

OBJECTIVE: To monitor by use of 5-color flow cytometry the antigen-specific responses of subsets of peripheral T cells in cattle inoculated with a killed Mycobacterium avium subsp paratuberculosis (MAP) vaccine and to compare results with those for 2 established cell-mediated immunity assays. ANIMALS: 45 female Holstein cattle with negative results for MAP in skin tests conducted at time of inoculation with MAP. PROCEDURES: Cattle were allocated to 4 groups. Cattle of group 1 (n = 12) were 0 to 3 months old and inoculated with a killed MAP vaccine. The 10 cattle of group 2 were the same age as those in group 1 but were not inoculated with MAP vaccine. The 11 cattle of group 3 were 9 to 12 months old and inoculated with killed MAP vaccine. The 12 cattle of group 4 were the same age as those in group 3 but were not inoculated with MAP vaccine. RESULTS: Flow cytometry identified T-cell subsets that responded specifically to the recall antigen. Results of assays for CD25 expression and wholeblood interferon-gamma had the strongest correlation with results for skin tests as well as results with each other. Intracellular expression of interferon-gamma was not correlated as well with results for the other tests. CONCLUSIONS AND CLINICAL RELEVANCE: Flow cytometry can be useful for characterizing the immune response after administration of MAP vaccine and should be evaluated with regard to its sensitivity and specificity when used in detecting cattle naturally infected with MAP.

Sensitivity and specificity of the agar-gel-immunodiffusion test, ELISA and the skin test for detection of paratuberculosis in United States Midwest sheep populations.

Our objective was to estimate the sensitivity and specificity of the agar-gel-immunodiffusion test (AGID), the ELISA, and the skin test for the detection of Mycobacterium avium subspecies paratuberculosis (MAP) in sheep using Bayesian methods without a gold standard. Fourteen flocks (2 465 sheep) were used. Five flocks (450 sheep) were considered MAP non-infected and 9 flocks (2 015 sheep) had sheep infected with MAP. Sheep were skin tested and blood was collected for AGID and ELISA testing. Results were analyzed using a Bayesian 3-test in 1-population model fitted in WinBUGS. The model allowed for dependence (correlation) between the two serologic tests, but these two tests were assumed to be conditionally independent of the skin test. The estimated specificity was 99.5% (95% PI of 98.9-99.9%) for the AGID; 99.3% (98.4-99.8%) for the ELISA using an optical density measured cutoff of 0.20; 99.2% (98.1-99.8%) using a cutoff of 0.15; 97.5% (95.8-98.7%) using a cutoff of 0.10; and 98.7% (97.3-99.5%) for the skin test. The estimated sensitivities were 8.3% (6.2-10.7%) for the AGID; 8.0% (6.0-10.4%), 10.6% (8.3-13.1%), and 16.3% (13.5-19.4%) for the ELISA using the cutoffs 0.20, 0.15, and 0.10 respectively; and 73.3% (62.3-85.8%) for the skin test. The skin test was specific in non-infected populations and sensitive in infected populations, although in some cases a positive skin test might represent MAP exposure rather than infection. The AGID and ELISA were specific but lacked sensitivity. The AGID and ELISA consistently identified two different populations of infected sheep with only moderate overlap between positive test results.

Epidemiologic investigation of Mycobacterium bovis in a population of cats.

OBJECTIVE: To determine whether cats exposed at a residence were infected with Mycobacterium bovis, whether the tuberculin skin test can identify cats infected with M bovis, and whether an ELISA could identify tuberculosis-infected cats. ANIMALS: 20 domestic cats exposed to a cat with laboratory-confirmed disseminated M bovis infection. PROCEDURE: Cats were administered a tuberculin skin test and monitored for 72 hours. Blood and fecal samples were collected. Cats were then euthanatized, and postmortem examinations were performed. Tissues were examined grossly and histologically for signs of mycobacteriosis. Pooled tissue samples and fecal samples were submitted for mycobacterial culture. Blood samples were examined for evidence of tuberculosis by use of a comparative ELISA. RESULTS: 4 cats had positive responses for the ELISA, and 2 cats had suspicious responses. All tuberculin skin tests yielded negative results. No gross or histologic lesions of tuberculosis were detected in any tissues, and mycobacteria were not isolated from tissues or feces obtained from the 20 cats. CONCLUSIONS AND CLINICAL RELEVANCE: All cats that had positive or suspicious responses for the ELISA were offspring of the cat with tuberculosis. Evidence of tuberculosis was not seen in other cats at the residence, the owner, or the attending veterinarian. The most likely source of tuberculosis for the infected cat was through the consumption of M bovis-infected wildlife carcasses or offal. Because M bovis is endemic in wildlife in northeastern Michigan, there is a risk of exposure to tuberculosis in companion animals, their owners, and attending veterinarians.

Identification of Mycobacterium paratuberculosis gene expression signals.

Mycobacterium paratuberculosis promoter-containing clones were isolated from a genomic DNA library constructed in the transcriptional-translational fusion vector pYUB76. The promoter-containing DNA fragments were identified in the surrogate host Mycobacterium smegmatis by expression of the promoterless lacZ reporter gene of pYUB76. The expression signals exhibited a wide range of strengths, as indicated by their corresponding beta-galactosidase activities. Eight clones were sequenced and characterized further. Predicted open reading frames and codon usage were identified by computer analysis. Database searching for related sequences using the BLAST method revealed no homologies. Transcriptional activity was measured by slot-blot hybridization with steady-state RNA isolated from lacZ+ M. smegmatis clones. Primer extension analysis identified the transcription start sites within the cloned fragments. The promoter regions characterized in this study were used to establish a consensus promoter sequence for M. paratuberculosis. M. paratuberculosis consensus hexanucleotide sequences of TGMCGT and CGGCCS centred approximately 35 and 10 bp upstream from the transcription startpoints do not correspond to the consensus hexanucleotides of Escherichia coli promoters.

Chemical Destruction of Mycobacterium bovis in Milk.

The tuberculocidal activity of phenol and 1-Stroke Environ was tested using five Mycobacterium bovis strains added separately to five samples of untreated cows milk. The tuberculocidal activity of each disinfectant was significantly improved (P = .005) by increasing exposure temperature from 4 to 23 C or by increasing exposure time from 1 to 6 h or by increasing disinfectant concentrations two-fold. Environ diluted 1:8 or phenol diluted 1:32 killed each of the five strains of M. bovis suspended in untreated milk (6 mg/ml) during a 6-h exposure at 23 C. Either disinfectant could be used to destroy M. bovis in unsalable milk from tuberculous cows scheduled for slaughter.