Evaluation of the abilities of three diagnostic tests based on the polymerase chain reaction to detect Mycobacterium paratuberculosis in cattle: application in a control program

Abstract

Three assays for the specific detection of Mycobacterium paratuberculosis by dot spot hybridization of polymerase chain reaction products were applied to fecal samples of dairy cattle. The first two tests used polymerase chain reaction primers and a DNA probe derived from M. paratuberculosis-specific sequences of the 16S rRNA gene and insertion element IS900, respectively. These two tests were carried out on spiked fecal samples to determine the detection limits. The 16S rRNA test was able to detect 107 bacteria per g of feces, and the IS900 test detected 104 to 105 per g of feces. Next, we studied the usefulness of these tests in a control program for paratuberculosis. Therefore, the tests and a third, commercially available, test (IDEXX Corp.) were used twice with an interval of 3 months on fecal samples of 87 cows from two dairy herds with a history of Johne's disease. We compared the results of these tests with those of culturing. This showed that the tests are specific but that the sensitivity ranged from 3 to 23%. Further improvement of the sensitivity is needed before the tests can be used in a control program to eradicate Johne's disease. Mycobactenum paratuberculosis is the etiologic agent of Johne's disease, a chronic inflammatory bowel syndrome in ruminants. The disease has been known for almost 100

Comparison of immunomagnetic bead separation‐polymerase chain reaction and faecal culture for the detection of Mycobacterium avium subsp paratuberculosis in sheep faeces

“…Earlier attempts to detect M a paratuberculosis directly in faecal samples by PCR have had limited success, limited application or were not reproducible. [17][18][19][20] Although most of and decrease milk production. 1 Aborted bovine foetuses show nonspecific lesions and various degrees of autolysis.…”

Detection of Mycobacterium Avium Subsp. Paratuberculosis in Bovine Fecal Samples: Comparison of Three Polymerase Chain Reaction—Based Diagnostic Tests with a Conventional Culture Method

“…13,19,21 More recently, several polymerase chain reaction (PCR) tests to detect MAP DNA have been developed. 1,5,8,23,27,29 The purpose of this study was to compare 3 PCR-based diagnostic kits with a conventional culture method for the detection of MAP in bovine fecal samples.…”

Use of the polymerase chain reaction assay for the detection of Mycobacterium avium subspecies paratuberculosis in blood and liver biopsies from experimentally infected sheep

“…1 Consequently, attempts to improve diagnostic procedures have been focused on the development of PCRbased methods for the detection of the organism in clinical specimens. [2][3][4][5] The detection of M a paratuberculosis DNA by the PCR assay in samples of blood and liver from a significant proportion of sheep with advanced clinical paratuberculosis 6 has raised some hope for the use of such a test for the diagnosis of infection in subclinical cases.…”