Gamma/delta T-cell lymphoma in a dog

A 15-month-old dachshund was presented for examination because of a cough. Thoracic radiographs revealed the presence of a mass in the upper mediastinum. A diagnosis of γδ T-cell lymphoma was made by biopsy and flow cytometry analysis. The dog was treated with chemotherapy and remains asymptomatic after 24 months.     

The effects of metribuzin on early life stages of common carp (Cyprinus carpio)

Metribuzin belongs to the triazine group of herbicides, which are frequently used in agriculture. The aim of this study was to assess the impact of metribuzin on growth and development of early life stages of fish. Subchronic toxic effects of metribuzin at concentrations of 0.9, 4, 14, and 32 mg/L on embryos and larvae of common carp (Cyprinus carpio) were investigated during a 30 day toxicity test under experimental conditions. Exposure to metribuzin at 32 mg/L was associated with increased mortality. Negative effects on total body length, weight, and inhibition of specific growth rate were induced by all experimental concentrations. Length and weight parameters were the most sensitive. The negative impact of metribuzin was observed in the highest tested concentration beginning on day 6 of exposure. Retardation of early ontogeny was associated with concentrations ?4 mg/L. Histological examination revealed changes in liver and caudal kidney after 30 days exposure to 32 mg/L. Based on growth parameters, development, and histological examination, the Lowest Observed Effect Concentration (LOEC) value was 0.9 mg/L.     

Paratuberculosis in a miniature donkey (Equus asinus f. asinus)

Paratuberculosis is mainly an infectious disease of ruminants with worldwide distribution. Infection occurs in early stages of life. Other animal species beyond ruminants are rarely affected, however, experimental and natural infections are possible. A case of paratuberculosis in a miniature donkey (Equus asinus f. asinus) with typical clinical and pathomorphological changes is reported here. Lesions were mainly observed in the intestine. Causative for the profuse diarrhoea with emaciation was massive diffuse granulomatous enteritis involving large quantities of acid-fast organism mainly in macrophages. Granulomatous inflammation with acid-fast bacilli again in macrophages to a lesser degree could be detected in the liver. Mycobacterium avium subsp. paratuberculosis (MAP) was isolated from intestinal contents after an incubation period of four weeks. MAP-specific DNA (IS900 and f57) was detected by polymerase chain reaction in culture material. Additionally MAP-isolates were characterized by multi-target genotyping (MIRU-VNTR- and MLSSR-typing). Isolates belonged to the Type II group and exhibited a unique genotype different from other MAP strains in Germany. The donkey originated from a donkey breeding farm in France with intensive free ranging cattle in the neighbourhood and could have been infected there. Donkeys should be considered as paratuberculosis-susceptible animals in exceptional cases and as possible reservoirs or disseminators of infection.     

Biochemical markers of morphogenesis in long term horseradish (Armoracia lapathifolia Gilib.) tissue culture

Long term in vitro cultures of plant tissue spontaneously change at morphological, cellular and biochemical level. Horseradish tissues were cultivated in vitro for more than 16 years. Primary crown-gall tumours were induced with Agrobacterium tumefaciens on leaf explants excised from plantlets propagated in vitro. Subcultured on hormone-free MS medium, transformed tissue continued to grow in an unorganized way (TN tumour) or as teratogenous tumour (TM teratoma) forming malformed shoots which never rooted. The aim of this study was to establish the morphological and biochemical status of this long term cultures. The study was performed by verifying biochemical marker of transformation and morphogenesis, which had been investigated when the culture was established (peroxidase, PPX) as well as by introducing new markers which have not been analyzed so far in horseradish tissues (ascorbate peroxidase, APX; phenylalanine-ammonia lyase, PAL; and phenolics content). Morphological changes were observed only in teratoma tissue. Peroxidase activity and isoenzyme pattern indicated stability of horseradish tissue culture. The new biochemical markers were in a complete (PAL) and partial (APX) correlation with the PPX results and are therefore useful addition in biochemical characterisation of these tissues and can also be applied as markers of morphogenesis and tumorization.     

Besteht das Risiko der Verschleppung der Bakteriellen Ringfäule der Kartoffel durch den Krautschläger?

In 2001 and 2002, two field trials were performed by the Plant Protection Service (PPS) of the Landwirtschaftskammer Weser-Ems in Oldenburg and the Institute for Plant Protection of the Bavarian State Research Center for Agriculture (LfL) in Freising respectively to examine the transmission of the bacterial ring rot pathogen of potato (Clavibacter michiganensis ssp. sepedonicus) by haulm cutting. In the experiment conducted by the PPS in Oldenburg a lawn-trimmer was used to simulate haulm cutting, before a bacterial suspension was sprayed on the ends of the cut haulms. Two cultivars (early and late) were tested and also the effect of an additional chemical measure for haulm destruction on the transmission of the pathogen was determined. In the trial performed at the LfL in Freising plots with infected plants for the contamination of the haulm cutter were treated immediately prior to plots with healthy plants. Infections of stems (re-growth) and tubers of the plants were determined by polymerase chain reaction (PCR) and indirect immunofluorescence antibody staining (IFAS). In the trials conducted with the haulm cutter, ring rot could be detected in the re-growth of 60% of the plants derived from healthy tubers 4 weeks after haulm cutting. It was confirmed in a bioassay, that the isolated pathogens were viable and virulent. Although the ring rot pathogen was transmitted to a great extent to the leaf material, no infection of progeny tubers occurred in a total of 450 tested plants. However in general a migration of the transmitted pathogen to the tubers cannot be excluded. Therefore further on it is advisable to clean and disinfect the haulm cutter before each use.     

Untersuchungen zur Übertragung von Clavibacter michiganensis ssp. sepedonicus, dem Erreger der Bakteriellen Ringfäule, in das Kraut von Kartoffelpflanzen

From 1999 to 2001, field trials were carried out to find out weather there is a risk of the causal agent of Bacterial Ring Rot of potato (Clavibacter michiganensis ssp. sepedonicus) to be transmitted to the leaves of healthy potato plants via contaminated machinery and equipment during the vegetation period and if so weather the bacteria are transported into the newly formed tubers. Two methods were chosen. Firstly, a sharp-edged metal bar contaminated with a bacterial suspension was drawn through the leaves of potato plants up to 6 times during the vegetation period. Secondly, a suspension of the pathogen was directly injected into the stems of potato plants. The harvested tubers were tested in all trials, leaves were additionally tested in the trial with the contaminated metal bar. The pathogen was not found in any trial. Therefore the risk for the transmission of the Ringrot agent to the leaves of potato plants with contaminated machinery might be very low.     

Die neue Datenbank ALPS-BBA — der komfortable, schnelle Weg zu Informationen über Alternativen zum chemischen Pflanzenschutz für Erzeuger und Berater

With the database ALPS-BBA (http://ALPS.BBA.de), the Federal Biological Research Centre for Agriculture and Forestry (BBA) contributes to promoting integrated pest management and to the necessary extent of applying plant protection products in crop farms. ALPS-BBA offers a comfortable way to search for combinations of crops and pests, possible specific measures, and for key words. Running free text search is also possible. The free text search, in particular, has a great potential for random queries. Web front end and layout allow intuitive navigation, and one can say that search is barrier-free. The database provides information for users who are able to determine crops and pests. Therefore diagnostic aids are not included. Specialised scientists will permanently improve and update the database.     

Mycobacterium gordonae as potential cause of granulomatous lesions of the toe tips in the South African clawed frog (Xenopus laevis)

During regular health status monitoring of the colony of amphibian, Mycobacterium (M.) gordonae were isolated from granulomatous lesions of the tiptoes from the South African clawed frog (Xenopus laevis) maintained at the Tierforschungszentrum of the University of Ulm. During a period of three years a total of 21 animals of the colony, consisting of 350-400 frogs, showed granuloma of the tip of the toes and a loss of the claws. The general condition and the behavior of the frogs appeared to be unchanged. Using a selective medium one isolate was cultured and identified by sequencing of the 16S rRNA gene. To apply a rapid diagnostic method for detecting mycobacteria, in particular M. gordonae in the health monitoring programme of the Xenopus laevis colony, we established the rpoB gene PCR followed by HaeIII restriction analysis of the PCR product. We identified M. gordonae from granuloma of the tiptoes and from unaltered tissue samples of the lungs and skin by PCR restriction analysis. Since mycobacterial species apparently are widespread in granulomatous lesions of the tiptoes of Xenopus laevis, we hypothesize a pathogenic potential. This view is supported by an increasing number of reports in the literature on infections with nontuberculous, "non-pathogenic" mycobacteria in Xenopus laevis.     

Age-dependent changes of proinflammatory cytokine production by porcine peripheral blood phagocytes

The aim of the present study was to determine postnatal ontogeny of proinflammatory cytokines IL-1beta, IL-8 and TNF-alpha production by in vitro stimulated porcine blood leukocytes. Four age categories of pigs were chosen. Cytokine production was determined using intracellular flow cytometry. It was found that IL-8 and TNF-alpha production by blood monocytes significantly increased during the postnatal period while production of IL-1beta remained unchanged. In blood neutrophils, the IL-8 production increased only during the postnatal period, while the levels of TNF-alpha and IL-1beta were undetectable during the whole postnatal period. Generally, the most intensive changes in cytokine production occurred before weaning. The production of low levels of cytokines by monocytes and neutrophils from young pigs was not caused by a delayed cytokine response because the cytokine production after 8-h stimulation was lower than that after 4-h stimulation in all age categories. The ontogenetical changes showed the same trends when two different stimulators (LPS, heat-inactivated E. coli) were used, suggesting that the ontogenetical changes are not caused by a simple defect in one signalling pathway, but it is probably a more complex process. No differences in cytokine production between the whole blood and the isolated cells supplemented with newborn or adult serum were found. Thus the ability of newborn monocytes and neutrophils to produce proinflammatory cytokines was not decreased due to the influence of composition of the microenvironment, where the cells were present. In conclusion, the ability of porcine blood leukocytes to produce cytokines develops during postnatal life.     

Growth characteristics of porcine chlamydial strains in different cell culture systems and comparison with ovine and avian chlamydial strains

Porcine Chlamydiaceae were cultivated under various culture conditions and we compared their growth characteristics with those of ruminant and avian strains. The combination of centrifugation assisted cell culture infection and cycloheximide treatment of Vero cell coverslip cultures provided the highest inclusion numbers with all chlamydial strains. Interestingly, the use of Iscove's modified Dulbecco's medium instead of Eagle's minimal essential medium significantly increased Chlamydia suis inclusion counts. C. suis and Chlamydophila pecorum inclusion numbers were markedly increased in CaCo cells, compared with Vero cells. This accelerated growth of porcine Chlamydiaceae under certain cultivation conditions may be helpful for the propagation of low chlamydial numbers or for their isolation from field samples. The intracellular distribution of porcine Chlamydiaceae in polarised CaCo cells clearly demonstrated differences between the chlamydial strains: C. pecorum 1710S inclusions were predominantly localised in the apical cytoplasm, C. suis S45 inclusions, however, were mostly situated in lower cytoplasmatic compartments. These findings might reflect biological differences in vivo.