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.     

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.     

Effect of varied soil nitrogen supply on growth and nutrient uptake of young Norway spruce plants grown in a shaded environment

To understand the effect of increased soil N supply on tree growth and nutrient uptake, three-year-old Norway spruce seedlings were grown in pots on low-nutrient mineral forest soil supplemented with N in mineral or organic form. Outdoor shaded growth conditions were used, to test the hypothesis that shaded plants are particularly susceptible to high soil N supply. Plants were harvested eleven months after planting. Shoot growth was not affected by the N supply, but N concentrations in needles and roots were increased in plants supplied with mineral N (150 or 300 mg N [kg soil]^—1). Root growth was drastically reduced and root/shoot ratios were decreased in plants with higher N uptake. A high supply of mineral N to soil also decreased the concentrations of other essential elements (P, K) in the needles and thus had effects on plant growth which may impair the stress resistance of trees. Organic N in the form of keratin (150 mg N [kg soil]^—1) did not influence plant growth significantly. The adverse effects of high mineral N supply were particularly pronounced under shaded conditions in comparison to results from other experiments using higher light intensity and temperature conditions.     

Aluminium and lead tolerance in ectomycorrhizal fungi

Al and Pb tolerance of different ectomycorrhizal fungi was tested in Petri dishes divided into three compartments. One compartment contained nutrient solution supplemented with Al or Pb but without P to avoid precipitation of Al or Pb phosphates. Phosphate was supplied in the agar compartment while a third compartment served as control containing nutrient solution without P. The tested ectomycorrhizal fungal species and isolates varied greatly in their Al and Pb tolerance. A more than 50% growth reduction was observed at 2000 μM Al in Paxillus involutus MAI but already at 200 μM in P. involutus NAU and P. involutus 533. In contrast, growth of Pisolithus tinctorius 956 appeared to be stimulated by Al. Al tolerance therefore decreased in the following order: P. tinctorius 956 > P. involutus MAI > P. involutus NAU, P. involutus 533. To test the effect of agar on Al tolerance, P. involutus MAI was grown with agar in all three compartments. In presence of agar, even 2000 μM Al had no effect on growth. Lead at concentrations of 1 and 10 μM Pb had no significant effect on fungal growth. A more than 50% decrease of mycelial surface area occurred at 500 μM Pb in P. involutus MAI and P. involutus 533 and at 100 μM Pb in P. involutus NAU and P. tinctorius 956. Pb tolerance therefore decreased in the following order: P. involutus MAI, P. involutus 533 > P. involutus NAU, P. tinctorius 956. Divided Petri plates appear to be a valuable tool to test metal tolerance of fungi as complexation of the metals by agar or precipitation with P are avoided. The results indicate that some ectomycorrhizal fungi may be more sensitive to Al and Pb than previously reported.