Free-living protists are ubiquitous in the environment and form a potential reservoir for the persistence of animal and human pathogens. Mycobacterium avium subsp. paratuberculosis is the cause of Johne's disease, a systemic infection accompanied by chronic inflammation of the intestine that affects many animals, including primates. Most humans with Crohn's disease are infected with this chroni...

Mycobacterium avium subsp. paratuberculosis (basonym M. paratuberculosis) is the causative agent of paratuberculosis, a chronic enteritis of ruminants. To control the considerable economic effect that paratuberculosis has on the livestock industry, a vaccine that induces protection with minimal side effects is required. We employed transposon mutagenesis and allelic exchange to develop three po...

Paratuberculosis is endemic in domestic and wild ruminants worldwide. We designed the following study to compare host immune responses and pathologic changes in beef calves and bison calves after challenge with either a cattle or bison (Bison bison) strain of Mycobacterium avium subsp. paratuberculosis. In the first part of the study, six bison and six beef calves were orally inoculated with a ...

OBJECTIVE To evaluate sensitivity and specificity of a new ELISA for antibodies against Mycobacterium avium subsp paratuberculosis. DESIGN Cross-sectional observational survey. SAMPLE POPULATION Serum samples from 590 cattle that were infected with M avium subsp paratuberculosis and 723 cattle that were not infected. PROCEDURE Serum samples were tested by use of an ELISA for antibodies ag...

An assay that is based on the amplification of 16S rRNA sequences and that was initially developed to detect Mycobacterium paratuberculosis in cattle was used to test 20 serotypes of the Mycobacterium avium complex (MAC) and atypical mycobacterial species not belonging to MAC. Only serotypes 1 to 6 and 8 to 11, designated M. avium, were detected by the assay, indicating that it can be used for ...

Mycobacterial isolates were obtained by radiometric culture from 33 different species of captive or free-ranging animals (n = 106) and environmental sources (n = 3) from six geographic zones within the United States. The identities of all 109 isolates were confirmed by using mycobactin J dependence and characterization of five well-defined molecular markers, including two integration loci of IS...

Five diagnostic tests based on enzyme-linked immunosorbent assay (ELISA) technology for bovine paratuberculosis were evaluated by using individual serum or milk samples from 359 dairy cattle in seven paratuberculosis-free herds and 2,094 dairy cattle in seven Mycobacterium paratuberculosis-infected dairy herds. Three independent laboratories using three different culture procedures completed fe...

Detection of Mycobacterium paratuber culosis in feces is complicated by the slowdivision and the lipid composition of the cell wall of the bacterium. In this study, we compared a rapid and sensitive method for direct detection of M. paratuberculosis with anti-paratuberculosis chicken IgY-conjugated magnetic nanoparticles versus commercially available micro-sized paramagnetic beads. Tenfold seri...

Ovine Johne's disease, or paratuberculosis, occurs in many countries. In Australia, surveillance using serology is used as part of a control program, but the testing regime is costly relative to its sensitivity. For this reason, culturing of Mycobacterium avium subsp. paratuberculosis in fecal samples pooled from a number of sheep was evaluated. Initially, the effect of pooling on the sensitivi...

Two monoclonal antibody-mediated immunomagnetic separation PCR kits (AnDiaTec ParaTub-S IMS-PCR-ELISA and ParaTub-SL IMS-real time PCR) were developed and evaluated for the automated high-throughput detection of Mycobacterium avium subsp. paratuberculosis (M. paratuberculosis) in bulk milk of naturally infected dairy herds and made commercially available. M. paratuberculosis are first isolated ...