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.     

Influence of water potential on nitrification and structure of nitrifying bacterial communities in semiarid soils

The objective of this study was to examine the relationship between soil water potential, nitrifier community structure and nitrification activity in semiarid soils. Soils were collected after a 5-month dry period (end of summer) and subsequently rewetted to specific water potentials and incubated for 7 days prior to analysis of nitrification activity and nitrifier community structure. The approach used in this study targeted a 491bp segment of the amoA gene which encodes the active site of the ammonia monooxygenase enzyme, which is the key enzyme for all aerobic ammonia oxidisers. amoA serves as a useful target for environmental studies since it is both specific and universal for all ammonia oxidisers and reflects the phylogeny of the ammonia oxidisers. Our results suggest that in semiarid soils water potential plays a key role in determining the structure of ammonia oxidising bacteria (AOB), and that additionally AOB community structure is correlated to potential nitrification rate in these soils.     

芳香植物精油对竹子根际微生物种群的影响

竹林生态系统虽然比较稳定,但病原菌也较多,使用生物农药是竹林可持续发展的必然道路。许多芳香植物精油具有优良的抗菌活性,都有作为生物农药的潜力。但是竹林土壤微生物也可能受到精油抑菌性能的影响。本研究选取常见5种芳香植物精油香茅、肉桂、大蒜、生姜和茶树精油,对其化学成分进行鉴定并对毛竹实生盆栽苗的土壤进行处理,测定毛竹根际土壤微生物的细菌丰度和种群多样性。结果表明,5种精油会降低毛竹根际微生物的丰度和多样性,使变形菌门的细菌成为绝对优势菌群。对微生物的影响从大到小依次是香茅、生姜、茶树、肉桂和大蒜精油。     

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.     

Plasma atrial natriuretic peptide concentration in warmblood horses with heart valve regurgitations

ObjectivesThis study measured plasma atrial natriuretic peptide (ANP) concentration in horses with heart valve regurgitations (HVR) with and without atrial and ventricular dilatation.BackgroundIn humans and small animals, plasma ANP concentration is increased in heart disease and correlates with the severity of clinical signs and heart enlargement.Animals, materials and methodsTen healthy horses (control) and 36 horses with HVR were evaluated by auscultation, electrocardiography, echocardiography, and determination of plasma ANP.ResultsControl horses demonstrated mean plasma ANP concentration of 21 ± 5.4 pg/mL. Of the 36 horses with HVR, 17 horses possessed normal echocardiographic heart size (group 1), 10 horses had a left atrial dilatation (group 2) and 9 horses had both left atrial and ventricular dilatation (group 3). Mean plasma ANP concentration of groups 1, 2 and 3 was 20.1 ± 5.6 pg/mL, 22.9 ± 11.0 pg/mL and 27.6 ± 17.4 pg/mL, respectively. The plasma ANP concentrations of HVR and control horses were not significantly different. The highest ANP concentrations were observed in horses with atrial and ventricular dilatation. No correlation between left atrial or ventricular size, weight, or sex and the plasma ANP concentration was found.ConclusionsNo significant differences in plasma ANP concentration was observed between groups. Further study, especially in horses with clinical signs of heart failure is needed.     

Tissue Doppler Imaging and Two-dimensional Speckle Tracking of Left Ventricular Function in Horses Affected with Recurrent Airway Obstruction before and after Clenbuterol Treatment

Cardiac effects of the β₂-adrenergic agent clenbuterol have been the focus of many studies, but effects on myocardial velocities and myocardial deformation parameters have not yet been evaluated in horses affected with recurrent airway obstruction (RAO) using tissue Doppler imaging (TDI) and two-dimensional speckle tracking (2DST). In our study, 7 horses affected by RAO were treated over 14 days with clenbuterol, 0.8 μg/kg every 12 hours. Standard echocardiographic, TDI (pulsed wave and color TDI), and 2DST examinations were performed before and after the treatment period. Myocardial function was recorded in the right parasternal short-axis view. Percent of fractional shortening and two-dimensional echocardiography (2DE) measurements did not show any significant changes after 2 weeks of treatment. Early diastolic velocity, E, increased significantly after clenbuterol in the left ventricular free wall (LVFW; P = .001). The E/late diastolic velocity (A) quotient (P = .003) and the isovolumetric contractility (P = .035) also increased significantly after treatment. Time parameters, particularly the time interval between the Q-wave in the echocardiograph and atrial release, the time of diastole and Tei index (parameter of global ventricular function), decreased significantly after clenbuterol administration in the LVFW (P = .014/P = .028/P = .015, respectively). The 2DE speckle tracking revealed a significant increase of the early diastolic systolic strain rate (P = .01) in the LVFW after therapy. In conclusion, 2 weeks of treatment with clenbuterol at a dosage of 0.8 μg/kg every 12 hours led to improved cardiac function in severely RAO-affected horses. This could be a sign of myocardial restoration (re-remodeling) after therapy.