Knowledge gaps that hamper prevention and control of Mycobacterium avium subspecies paratuberculosis infection.

In the last decades, many regional and country-wide control programmes for Johne's disease (JD) were developed due to associated economic losses, or because of a possible association with Crohn's disease. These control programmes were often not successful, partly because management protocols were not followed, including the introduction of infected replacement cattle, because tests to identify infected animals were unreliable, and uptake by farmers was not high enough because of a perceived low return on investment. In the absence of a cure or effective commercial vaccines, control of JD is currently primarily based on herd management strategies to avoid infection of cattle and restrict within-farm and farm-to-farm transmission. Although JD control programmes have been implemented in most developed countries, lessons learned from JD prevention and control programmes are underreported. Also, JD control programmes are typically evaluated in a limited number of herds and the duration of the study is less than 5 year, making it difficult to adequately assess the efficacy of control programmes. In this manuscript, we identify the most important gaps in knowledge hampering JD prevention and control programmes, including vaccination and diagnostics. Secondly, we discuss directions that research should take to address those knowledge gaps.

A rapid agglutination assay to detect anti-streptokinase antibodies.

BACKGROUND: Streptokinase resistance may cause suboptimal thrombolytic therapy. AIM: To develop a rapid latex-bead assay to detect streptokinase antibodies. METHODS: Sera were obtained from 16 patients presenting with acute myocardial infarction (MI) before treatment with streptokinase and 1 and 6 months post treatment, and from 100 controls. Sera were assayed for anti-streptokinase antibodies using a functional streptokinase-neutralising assay. RESULTS: Streptokinase-neutralising activity was low in controls (54 +/- 5U/ml) and patients prior to treatment (101 +/- 18), increasing to 2,110 +/- 823 and 1,017 +/- 169 at 1 and 6 months (mean +/- SEM). The latex assay had a sensitivity of 94% and a specificity of 93% for detecting individuals with > 350U/ml of streptokinase resistance, which is sufficient to neutralise the drug clinically. CONCLUSIONS: Estimation of streptokinase resistance using an enzyme immunoassay and a latex bead assay correlated well with serum neutralising activity. This assay can rapidly identify patients who have a high level of streptokinase-neutralising activity.

Bactericidal effect of a whey protein concentrate with anti-Helicobacter pylori activity.

AIMS: To investigate the effect of whey protein concentrate (WPC) enriched in anti-Helicobacter pylori antibodies on growth of the organism in vitro. METHODS AND RESULTS: A WPC rich in H. pylori-specific antibodies was produced by immunizing lactating cows against H. pylori and processing pooled bulk milk samples into whey powder. The antibodies bound several proteins within the bacterial homogenate and were active at pH 5. In a complement-dependent reaction, the immune WPC was highly bactericidal against four H. pylori strains tested in vitro. CONCLUSION: WPC produced with milk from H. pylori-immunized cows contains antibodies that are active at the pH of the stomach, and bactericidal against H. pylori in vitro, via the classical complement pathway. SIGNIFICANCE AND IMPACT OF THE STUDY: This study has demonstrated the potential for use of WPC in the prevention/treatment of H. pylori infections.