The purpose of this paper is to present and update the longitudinal perspective of the Mycobacterium avium subspecies paratuberculosis dilemma as initially stated in Infectious Diseases Incorporated’s 2012 White Paper. In both wild and domestic herbivores, Mycobacterium avium subspecies paratuberculosis (MAP) produces chronic granulomatous enteritis (Johne’s disease) that, if unchecked, is usua...

The cross-reactivity of mycobacterial antigens in immune-based diagnostic assays has been a major concern and a criticism of the current tests that are used for the detection of paratuberculosis. In the present study, Mycobacterium avium subsp. paratuberculosis recombinant proteins were evaluated for antigenic specificity compared to a whole-cell sonicate preparation (MPS). Measures of cell-med...

The characterization of protective antigens is essential for the development of an effective, subunit-based vaccine against paratuberculosis. Surface-exposed and secreted antigens, present abundantly in mycobacterial culture filtrate (CF), are among the well-known protective antigens of Mycobacterium tuberculosis and Mycobacterium bovis. Culture filtrate, prepared from Mycobacterium avium subsp...

Microarray-based comparisons of three Mycobacterium avium subsp. paratuberculosis isolates, including one sheep strain and two cattle strains, identified three large genomic deletions in the sheep strain, totaling 29,208 bp and involving 24 open reading frames. These deletions may help explain some of the differences in pathogenicity and host specificity observed between the cattle and sheep st...

Mycobacterium avium subsp. paratuberculosis causes Johne's disease, a systemic infection and chronic inflammation of the intestine that affects many species, including primates. Infection is widespread in livestock, and human populations are exposed. Johne's disease is associated with immune dysregulation, with involvement of the enteric nervous system overlapping with features of irritable bow...

The FASTPlaqueTB assay is an established diagnostic aid for the rapid detection of Mycobacterium tuberculosis from human sputum samples. Using the FASTPlaqueTB assay reagents, viable Mycobacterium avium subsp. paratuberculosis cells were detected as phage plaques in just 24 h. The bacteriophage used does not infect M. avium subsp. paratuberculosis alone, so to add specificity to this assay, a P...

By a suppression subtractive hybridization based method, nine novel Mycobacterium avium subsp. paratuberculosis (M. paratuberculosis) fragments of between 318 and 596 bp have been identified and characterized. Database search revealed little or no similarity with other mycobacteria. The uniqueness and diagnostic potential of seven of these fragments in relation to M. paratuberculosis closest re...

Johne's disease, caused by infection with Mycobacterium avium subsp. paratuberculosis, causes significant economic losses to the livestock farming industry. Improved investigative and diagnostic tools-necessary to understand disease processes and to identify subclinical infection-are much sought after. Here, we describe the production of single-chain antibodies with defined specificity for M. a...

OBJECTIVE To evaluate the effect of exposure to environmental mycobacteria on results of 2 commercial ELISAs for paratuberculosis in cattle. DESIGN Experimental trial. ANIMALS 19 weaned crossbred beef calves. PROCEDURES Calves were inoculated SC with 1 of 5 mycobacterial isolates (3 calves/isolate) derived from herds with high proportions of false-positive serologic reactions for paratube...

The in vitro susceptibility of human- and bovine-origin Mycobacterium paratuberculosis to the thioupurine drugs 6-mercaptopurine (6-MP) and azathioprine (AZA) was established using conventional plate counting methods and the MGIT 960 ParaTB culture system. Both 6-MP and AZA had antibacterial activity against M. paratuberculosis; isolates from Crohn's disease patients tended to be more susceptib...