Evaluation of five ELISA test kits for the measurement of antibodies against Mycobacterium avium subspecies paratuberculosis in bovine serum.

Five commercially available ELISA tests for the detection of antibodies against Mycobacterium avium subsp. paratuberculosis in bovine serum were evaluated at the individual animal level using sera from 286 paratuberculosis-free and 110 paratuberculosis-infected dairy cattle. Sensitivity (Se) and specificity (Sp) of the tests were estimated after determination of the cut-off dtheta by TG-ROC analysis or using the cut-off values recommended by the manufacturers, respectively.

Ochratoxin A and some of its derivatives modulate radical formation of porcine blood monocytes and granulocytes.

Modulating effects of ochratoxin A (OTA) and some of its derivatives on viability and oxidative burst activity of porcine monocytes and granulocytes have been studied. The formation of free oxygen radicals by monocytes was suppressed by OTA and ochratoxin C (OTC) at concentrations between 10 and 1000 ng/ml. Intracellular radical formation of granulocytes was in part already significantly reduced at 1 ng/ml of these mycotoxins.

Effects of the mycotoxin ochratoxin A and some of its metabolites on the human cell line THP-1.

The immunomodulatory effects of ochratoxin A (OTA) and some of its metabolites on the human monocyte/macrophage line THP-1 are described. Metabolic activity, cell proliferation, cell membrane integrity, cell differentiation, phagocytic behaviour, nitrogen oxide synthesis and cell surface markers were largely suppressed by these mycotoxins at concentrations between 10 and 1000 ng/ml, in individual cases already at 1 ng/ml. After analysis of a crude toxin, a substance designated RE2 could be isolated besides OTA, which was identified as ochratoxin C (OTC).