Methods to improve the ELISA test to detect Mycobacterium avium subsp. paratuberculosis have been explored over several years. Previously, selected recombinant proteins of M. avium subspecies paratuberculosis were found to be immunogenic in cattle with Johne's disease. In the present study, antibody responses of infected and healthy sheep were evaluated using 18 purified recombinant proteins in...

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...

Johne's disease (JD) is a chronic enteric disease caused by Mycobacterium avium subsp. paratuberculosis that affects ruminants. Transmission occurs by the fecal-oral route. A commonly used antemortem diagnostic test for the detection of M. avium subsp. paratuberculosis in feces is liquid culture; however, a major constraint is the 2- to 3-month incubation period needed for this method. Rapid me...

OBJECTIVE To estimate seroprevalence of Mycobacterium avium subsp paratuberculosis (MAP) infection among adult dairy cows in Colorado and determine herd-level factors associated with the risk that individual cows would be seropositive. DESIGN Cross-sectional observational study. ANIMALS 10,280 adult (> or = 2 years old) dairy cows in 15 herds in Colorado. PROCEDURE Serum samples were test...

We previously reported that protein antigens of serodiagnostic potential were more abundant in culture filtrates than cellular extracts from liquid cultures of Mycobacterium avium subsp. paratuberculosis (D. Cho and M. T. Collins, Clin. Vaccine Immunol. 13:1155-1161, 2006). Based on this observation, a novel enzyme-linked immunosorbent assay (ELISA) using antigens secreted by young (early- to m...

In cattle, Mycobacterium avium subsp. paratuberculosis infection is primarily mediated through M cells overlying Peyer's patches (PP) in the ileum. The capacity of M. avium subsp. paratuberculosis to invade ileal PP (IPP) versus discrete PP in the jejunum (JPP) and subsequent differences in mucosal immune responses were investigated. Intestinal segments were surgically prepared in both mid-jeju...

Multitarget genotyping of the etiologic agent Mycobacterium avium subsp. paratuberculosis is necessary for epidemiological tracing of paratuberculosis (Johne's disease). The study was undertaken to assess the informative value of different typing techniques and individual genome markers by investigation of M. avium subsp. paratuberculosis transmission between wild-living red deer and farmed cat...

Infections caused by the Mycobacterium avium complex (MAC) are on the rise in both human and veterinary medicine. A means of effectively discriminating among closely related yet pathogenetically diverse members of the MAC would enable better diagnosis and treatment as well as further our understanding of the epidemiology of these pathogens. In this study, a five-target multiplex PCR designed to...

Two antigens ('cattle' type and 'Indian Bison' type) of Mycobacterium avium subspecies paratuberculosis were evaluated for diagnosis of Johne's disease (JD) in a gaushala (cattle herd). Of the 160 cows of Sahiwal and Hariana breeds screened, 81 (50.6%) tested positive in ELISA and 66 (41.8%) in AGPT test. Using the two antigens, 33.5% tested positive in both the tests while 41.1% tested negativ...