Elucidating Transmission Patterns of Endemic subsp. Using Molecular Epidemiology.

Mycobacterial diseases are persistent and characterized by lengthy latent periods. Thus, epidemiological models require careful delineation of transmission routes. Understanding transmission routes will improve the quality and success of control programs.

Dysbiosis of the Fecal Microbiota in Cattle Infected with Mycobacterium avium subsp. paratuberculosis.

Johne's disease (JD) is a chronic, intestinal infection of cattle, caused by Mycobacterium avium subsp. paratuberculosis (MAP). It results in granulomatous inflammation of the intestinal lining, leading to malabsorption, diarrhea, and weight loss.

Impact of the shedding level on transmission of persistent infections in Mycobacterium avium subspecies paratuberculosis (MAP).

Super-shedders are infectious individuals that contribute a disproportionate amount of infectious pathogen load to the environment. A super-shedder host may produce up to 10,000 times more pathogens than other infectious hosts. Super-shedders have been reported for multiple human and animal diseases.

Cost-effectiveness of diagnostic strategies to identify Mycobacterium avium subspecies paratuberculosis super-shedder cows in a large dairy herd using antibody enzyme-linked immunosorbent assays, quantitative real-time polymerase chain reaction, and bacterial culture.

Diagnostic strategies to detect Mycobacterium avium subsp. paratuberculosis (MAP) super-shedder cows in dairy herds have been minimally studied. The objective of the current study was to compare the cost-effectiveness of strategies for identification of MAP super-shedders on a California dairy herd of 3,577 cows housed in free-stall pens.

Evaluation of the in vitro activity of gallium nitrate against Mycobacterium avium subsp paratuberculosis.

Objective: To evaluate the in vitro susceptibility of various field isolates of Mycobacterium avium subsp paratuberculosis (MAP) to gallium nitrate.

Sample: 10 isolates of MAP, including 4 isolated from cattle, 2 isolated from bison, 1 isolated from an alpaca, and 3 isolated from humans.

Procedures: The in vitro susceptibility to gallium nitrate was tested by use of broth culture with detection of MAP growth by means of a nonradiometric automated detection method.

Molecular epidemiology of Mycobacterium avium subsp. paratuberculosis in a longitudinal study of three dairy herds.

The objective of this study was to evaluate whether cows that were low shedders of Mycobacterium avium subsp. paratuberculosis were passively shedding or truly infected with M. avium subsp.

Longitudinal study of ELISA seroreactivity to Mycobacterium avium subsp. paratuberculosis in infected cattle and culture-negative herd mates.

Two thousand nine hundred fifty-two serum samples, collected once or twice annually from 545 cows of known fecal culture status were tested for antibodies to Mycobacterium avium subsp. paratuberculosis using a commercially available enzyme-linked immunosorbent assay (ELISA) test. Overall, 13.

Fecal shedding of Mycobacterium avium subsp. paratuberculosis by dairy cows.

Between 1982 and 2000, fecal samples were obtained from 786 cows that were shedding Mycobacterium avium subsp. paratuberculosis (Map). These cows were resident on 93 Pennsylvania dairies (mean herd size, 64 milk cows) that had no or minimal previous testing for Map.

Evaluation of microbial culture of pooled fecal samples for detection of Mycobacterium avium subsp paratuberculosis in large dairy herds.

Objective: To evaluate sensitivity of microbial culture of pooled fecal samples for detection of Mycobacterium avium subsp paratuberculosis (MAP) in large dairy herds and assess the use of the method for estimation of MAP prevalence.

Animals: 1,740 lactating cows from 29 dairy herds in California.

Procedure: Serum from each cow was tested by use of a commercial ELISA kit.

Evaluation of bacteriologic culture of pooled fecal samples for detection of Mycobacterium paratuberculosis.

Objectives: To compare sensitivity of several methods of bacteriologic culture of pooled bovine fecal samples for detection of Mycobacterium paratuberculosis and evaluate homogeneity in number of M paratuberculosis in pooled fecal samples.

Sample Population: Feces from 10 dairy cows that shed M paratuberculosis at various concentrations and 1 dairy cow known to be free of infection with M paratuberculosis.

Procedure: 5 fecal pooling methods, 2 culture methods, and 2 pool sizes were evaluated.