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Background Environmental sampling based on boot swabs and/or liquid manure samples is an upcoming strategy for the identification of paratuberculosis (paraTB) positive herds, but only limited data are available regarding the diagnostic performance of molecular detection methods (qPCR) versus faecal culture (FC) for this purpose. In the present study, the test characteristics of two different qPCR protocols (A and B) and a standardized FC protocol, for the detection of Mycobacterium avium subsp. paratuberculosis in boot swabs and liquid manure samples were evaluated. Results In 19 paraTB unsuspicious and 58 paraTB positive herds boot swabs and liquid manure were sampled simultaneously and analyzed in three different diagnostic laboratories. Using boot swabs and liquid manure, a substantial to excellent accordance was found between both qPCRs, for boot swabs also with culture, while for liquid manure the detection rate of culture was decreased after prolonged storage at −20 °C. The quantitative results of both qPCR methods correlated well for the same sample and also for boot swabs and liquid manure from the same herd. When cut-off threshold cycle (CT-)-values were applied as recommended by the manufacturers, herd level specificity (Sp) of qPCR B was below 100% for boot swabs and for both qPCRs for liquid manure. A decreased herd level sensitivity was encountered after adjustment of Sp to 100% and re-calculation of the cut-off CT-values. Conclusions qPCR is equally suitable as bacterial culture for the detection of Mycobacterium avium subsp. paratuberculosis in boot swabs and liquid manure samples. Both matrices represent easily accessible composite environmental samples which can be tested with reliable results. The data encourage qPCR testing of composite environmental samples for paraTB herd diagnosis.

Background Paratuberculosis caused by Mycobacterium avium subsp. paratuberculosis (MAP) is difficult to control due to a long phase of clinically non-apparent (latent) infection for which sensitive diagnostics are lacking. A defined animal model for this phase of the infection can help to investigate host-MAP interactions in apparently healthy animals and identify surrogate markers for disease progress and might also serve as challenge model for vaccines. To establish such a model in goats, different age at inoculation and doses of oral inoculum of MAP were compared. Clinical signs, faecal shedding as well as MAP-specific antibody, IFN-γ and IL-10 responses were used for in vivo monitoring. At necropsy, about one year after inoculation (pi), pathomorphological findings and bacterial organ burden (BOB) were scored. Results MAP infection manifested in 26/27 inoculated animals irrespective of age at inoculation and dose. Clinical signs developed in three goats. Faecal shedding, IFN-γ and antibody responses emerged 6, 10–14 and 14 wpi, respectively, and continued with large inter-individual variation. One year pi, lesions were detected in 26 and MAP was cultured from tissues of 23 goats. Positive animals subdivided in those with high and low overall BOB. Intestinal findings resembled paucibacillary lesions in 23 and multibacillary in 4 goats. Caseous and calcified granulomas predominated in intestinal LNN. BOB and lesion score corresponded well in intestinal mucosa and oGALT but not in intestinal LNN. Conclusions A defined experimental infection model for the clinically non-apparent phase of paratuberculosis was established in goats as suitable basis for future studies.

Acute respiratory distress syndrome (ARDS) in young infants is linked with a pulmonary inflammatory response part of which are increased interleukin-8 (IL-8) levels and migration of polymorphonuclear leukocytes (PMNL) into lung tissue. A topical application of an antibody against IL-8 might therefore decrease PMNL migration and improve lung function. Randomized, controlled, prospective animal study. Research laboratory of a university children’s hospital. Anesthetized, mechanically ventilated newborn piglets (n=22) underwent repeated airway lavage to remove surfactant and to induce lung inflammation. Piglets then received either surfactant alone (S, n=8), or a topical antibody against IL-8 admixed to surfactant (S+IL-8, n=8), or an air bolus injection (control, n=6). After 6 h of mechanical ventilation following intervention, oxygenation [S 169±51 (SD) vs S+IL-8 139±61 mmHg] and lung function (compliance: S 1.3±0.4 vs S+IL-8 0.9±0.4 ml/cmH2O/kg; extra-vascular lung-water: S 27±9 vs S+IL-8 52±28 ml/kg) were worse in the S+IL-8 group because reactive IL-8 production [S 810 (median, range 447–2323] vs S+IL-8 3485 (628–16180) pg/ml; P

An in-vitro model was developed to study the effects of a long-term exposure with a low concentration of ochratoxin A (OTA) or ochratoxin C (OTC) on a human monocytic cell line (THP-1).Cells were propagated in 24-well cell culture plates for 15 days. OTA and OTC preparations, respectively, at a concentration of 1 ng/ml were included in the cell culture medium during the whole cultivation period. At the end of the exposure time, parameters of cell viability and cell function were examined.After 15 days of exposure to ochratoxins, viability and function of the THP-1 cell line were modulated. Mitochondrial activity and the production of IL-6 were increased by all mycotoxin preparations. Cell membrane integrity was disturbed, proliferation and the production of TNF-α and IL-8 were inhibited. These parameters were most severely affected by mycotoxin preparations containing OTC.Our results show that long term exposure to OTA and especially OTC in low concentrations can cause subtle alterations of cell viability and function which may have remarkable consequences for human and animal health. In this context it seems to be necessary to study the contamination of food and feed stuffs with OTC more intensively.

The effect of ochratoxin A (OTA) and C (OTC) on the cytolytic activity of natural killer cells (NK cells) was studied using a fluorescence based bioassay with the cell line NK-92 as effector cell line and K-562 as target cell line. Different OTA and OTC preparations were included in the study. After exposure to very low toxin concentrations (1–10 ng/ml) a slight stimulation of NK cell activity was noted, whereas after addition of higher toxin concentrations (100–1000 ng/ml) NK cell function was suppressed. Preparations containing OTC showed a stronger effect than those containing OTA.

The effect of practically relevant mycotoxin concentrations on functions of immune cells was studied in in vitro experiments. Porcine mononuclear cells were exposed to a crudeAspergillus-ochraceus toxin containing OTA, a HPLC fraction identical with OTC derived from the crude toxin (RE2), as well as pure OTA and OTC in a concentration range from 0.46 to 3000 ng/ml. The influence of mycotoxin exposure on metabolic activity, mitogen induced proliferation, expression of the activation marker CD25 and the cell cycle of lymphocytes and on the formation of free oxygen radicals as well as the production of the cytokines IL-6 and TNF-α by monocytes was determined. Exposure to high concentrations of all mycotoxin preparations lead to non-specific suppression of the immune cell functions, which was related to cytotoxic effects. Low concentrations caused ambivalent reactions, especially on monocyte function. In general, the HPLC fraction RE2 had an up to 100-fold stronger effect than pure OTA. Ochratoxin-induced suppression of lymphocyte proliferation was not abrogated by phenylalanine or aspartame. The results indicate that immunomodulation can be caused by very low mycotoxin concentrations which are not related to clinical symptoms or loss of performance.

Die Maus-Thymoma-Zellinie EL-4 diente alsin-vitro-T-Zell-Modell fur Untersuchungen immunmodulatorischer Effekte von reinem Ochratoxin A (OTA) sowie von einerAspergillus-ochraceaus-Rohtoxinpraparation. Die Zytokinproduktion (IL-2, IL-4, IL-5, IL-6) und die Vitalitat PMA-stimulierter EL-4-Zellen wurde unter OTA-Einwirkung untersucht. Rohtoxin wirkte im Vergleich zum reinen OTA bereits bei niedrigeren OTA-Konzentrationen zytotoxisch (IC50-Werte 3 bzw. 11 µg/ml). Steigende Konzentrationen von beiden OTA-Praparationen fuhrten zur Hemmung der Zytokin-Ausschuttung, wobei Rohtoxin wiederum starker wirkte. Dies deutet auf den Einflus weiterer noch nicht naher charakterisierter Bestandteile des Rohtoxins hin. Die unterschiedlichen Hemmkonzentrationen von OTA gegenuber den einzelnen Zytokinen machen deutlich, das auch eine unterschiedliche Empfindlichkeit der betreffenden Regulations-Mechanismen vorliegen konnte. Bei bestimmten Konzentrationen waren bei IL-2 und IL-6 auch stimulierende Effekte beider Toxin-Praparationenen nachweisbar, wogegen diese Konzentrationen bei IL-4 und IL-5 bereits hemmten.

Die Uberwachung und Bekampfung vom Tier auf den Menschen ubertragbarer Krankheiten (Zoonosen) wurde in der Europaischen Union durch das In-Kraft-Treten einer neuen Zoonosenrichtlinie kurzlich auf eine neue Grundlage gestellt. Eine Uberwachungspflicht fur Brucellose, Campylobacteriose, Echinokokkose, Listeriose, Salmonellose, Trichinellose und die jeweiligen Erreger, Tuberkulose (soweit sie durch Mycobacterium bovis verursacht ist) sowie Verotoxin bildende Escherichia coli wird festgelegt. Fur weitere Zoonosen und Zoonosenerreger gilt die Uberwachungspflicht je nach der epidemiologischen Situation. Auf diesem Hintergrund werden der aktuelle Kenntnisstand und die epidemiologische Situation wichtiger von Nutz- und einigen Wildtieren auf den Menschen ubertragbarer Infektionskrankheiten in Deutschland dargestellt.