Pathologic and immunohistochemical findings in an outbreak of systemic toxoplasmosis in a mob of red kangaroos

Toxoplasma gondii is a zoonotic protozoan pathogen that infects many endothermic vertebrates, including humans; the domestic cat and other felids serve as the definitive host. Macropodids are considered highly susceptible to toxoplasmosis. Here, we describe the clinical, pathologic, and immunohistochemical findings of an outbreak of systemic toxoplasmosis in a mob of 11 red kangaroos (Macropus rufus), with high morbidity (73%) and mortality (100%) rates. Affected animals had either severe and rapidly deteriorating clinical conditions or sudden death, which was correlated with widespread necrotizing lesions in multiple organs and intralesional T. gondii organisms identified via MIC3-specific immunohistochemistry and confirmed by REP529-specific rtPCR. Quantification of parasites demonstrated the highest parasite density in pulmonary parenchyma compared with other tissues. Our study highlights the continued importance of this severe condition in Australian marsupials.     

Describing Human–Wildlife Interaction from a European Perspective

European researchers from both the natural and social sciences show growing interest in studying interactions between society and wildlife. A wealth of theoretical frameworks, concepts, and methods are used, but an integration of perspectives is lacking. This research note summarizes results from two workshops that included 63 delegates from 25 European countries, as well as a follow-up survey of 41 respondents. Two main theoretical approaches to the study of human–wildlife interactions were identified. One approach focuses on the collective societal level relying on theories of governance, social representation, deliberative procedures, and commons theory. The other approach targets individuals or groups, and is based on theories such as the cognitive hierarchy, theory of reasoned action, and theory of planned behavior. Interdisciplinary collaboration is needed to identify the best options for wildlife conservation and management in a more politically integrated Europe.     

Frequency of superantigen-producing Staphylococcus intermedius isolates from canine pyoderma and proliferation-inducing potential of superantigens in dogs

This preliminary study investigated the potential role of staphylococcal superantigens in the pathogenesis of canine pyoderma. The staphylococcal enterotoxins A (SEA), SEB, SEC and SED, and the toxic shock syndrome toxin-1 (TSST-1) were assayed in isolates from skins of dogs with pyoderma. Culture supernatants from 25 of 96 isolates were positive for multiple superantigens, with SEA and SEC being the most frequently detected. In in vitro stimulation of canine peripheral blood mononuclear cells and quantitative flow cytometry revealed that low concentrations of SEA and SEB were potent stimulators of blastogenesis of T cells.     

Different reactions of central and marginal provenances of Fagus sylvatica to experimental drought

Climate extremes are expected to increase in frequency and magnitude as a consequence of global warming, threatening the functioning, services and goods of forest ecosystems. Across Europe, the ecologically and economically important tree species Fagus sylvatica is expected to suffer particularly under such conditions. The regional introduction of provenances from drier and warmer climates is one option to adapt beech forest ecosystems to these adverse effects of climate change. Marginal populations from the drought-prone southern and north-eastern edges of the species’ distribution come into focus in search of suitable candidates for Central European deciduous forests. Here, we test three marginal provenances (Spain, Bulgaria and Poland) and three provenances from the centre of the distribution range (Germany) for their response to drought in two different soil types (sand, loam) in a full factorial common garden experiment in Landau, Germany. Drought impacted all growth parameters negatively (leaf damage +22 % (percentage points), height ?40 % and diameter increment ?41 %), and the sandy substrate exacerbated this effect. However, provenances differed in their response to drought and soil type. Evidence for a local adaptation to summer drought was detected, especially in terms of mortality rates. The Bulgarian and Spanish provenance showed a stable performance under drought conditions (BG ?27 % in diameter increment; ES ?32 %), compared to the Polish (?48 %) or the most sensitive German provenances (?57 %), yet for Bulgaria on a low level of total increment. This may indicate a trade-off between drought tolerance and growth. Therefore, a sole focus on drought-resistant marginal provenances seems to not be conducive, as they might be less adapted to other climatic factors, e.g. frost, as well. However, intermixed with local Central European provenances, these may act as functional insurance in future drought-prone forest stands.     

Influence of a probiotic Enterococcus faecium strain on selected bacterial groups in the small intestine of growing turkey poults.

A feeding trial was carried out with turkey poults, which were fed a diet containing 10(10) viable probiotic E. faecium NCIB 10415 cells/kg feed. Samples of the intestinal tract were analyzed for lactate, colony forming units of total anaerobic bacteria, lactic acid bacteria, enterobacteria and enterococci. Furthermore, metabolic activity of total eubacterial, lactobacilli and enterococci was recorded in selected RNA-extracts with specific ribosomal RNA oligonucleotide probes. Animals fed the probiotic diet showed continously increasing lactate concentrations throughout the sampling period up to day 42 of life. No correlation was found for colony forming units (cfu) of lactic acid bacteria, but metabolic activity of lactobacilli showed very close relation to continously increasing lactate concentrations. Throughout the feeding trial, enterococci in the control group continously increased to a maximum of 10(4) cfu/g wet weight, but 10-fold higher enterococci cfu were generally found in the treated group. However, rRNA content as measure for metabolic activity showed a drastic decline in both groups after high metabolic activities on day 7. This study shows that E. faecium NCIB 10415 (E. faecium SF68) stimulates other lactic acid bacteria in the small intestine, especially lactobacilli.     

Aluminium precipitates from groundwater of an aquifer affected by acid atmospheric deposition in the Senne,Northern Germany

White precipitates collected from stream bottoms and well tubes in the Senne area consist of amorphous aluminium hydroxide, coprecipitated with minor amounts of sulfate, phosphate and silica. The precipitates have presumably formed by the interaction of slightly alkaline water from calcareous subsoil sediments, with acidic water draining off sandy soils affected by high inputs of acidic atmospheric deposition. From many hydrochemical studies, precipitation of aqueous aluminium is known to occur in subsurface horizons of acid soils affected by acid rain. On the basis of presumed equilibrium with soil solutions, jurbanite, AlOHSO₄ · 5H₂O, is often assumed to be the secondary mineral involved. However, direct evidence for jurbanite from solid phase analysis is lacking. This first analysis of such a secondary phase does not support the jurbanite hypothesis, and shows that amorphous Al hydroxide can be formed instead.     

A method to assess whether ‘preferential use’ occurs after N ammonium addition; implication for the N isotope dilution technique

The robustness of the assumption of equilibrium between native and added N during ¹⁵N isotope dilution has recently been questioned by Watson et al. (Soil Biol Biochem 32 (2000) 2019-2030). We re-analyzed their raw data using equations that consider the added and native NH₄⁺ and NO₃⁻ pools as separate state variables. Gross mineralization rates and first-order rate constants for NH₄⁺ and NO₃⁻ consumption were obtained by combining analytical integration of the differential equations with a non-linear fitting procedure. The first-order rate constants for NH₄⁺ consumption and NO₃⁻ immobilization for the added NH₄⁺ and NO₃⁻ pool were used to estimate gross mineralization rates and first-order rate constants for nitrification of native NH₄⁺. The latter were 2-4 times lower than the first-order rate constants derived from the added N pool. This discrepancy between first-order rate constants for nitrification implies that one or more process rates estimated for the added N pools cannot be applied to the native N pools. Preferential use of the added N resulted in an overestimation of the gross mineralization by 1.5-2.5-fold, emphasizing the need for critical evaluation of the assumption of equilibrium before gross mineralization rates are calculated.