Thermic dehorning and ear tagging as atypical portals of entry of Clostridium tetani in ruminants

This paper describes two infections with Clostridium tetani (C. tetani). One outbreak occurred after dehorning of calves, the second infection happened after ear tagging of a goat. In the first case 3 young Holstein Friesian calves showed generalized stiffness, severe lock-jaw and bloat two weeks after dehorning. The thermal dehorning wounds were identified as the infection sites of C. tetani by bacterial culture and PCR. The second case was a three-year old male castrated goat, with generalized stiffness. The animal had been ear tagged one week prior to the onset of the symptoms. C. tetani could be cultured from pus on the ear tag. Treatment was attempted in two calves and the goat. Wounds were debrided and disinfected, penicillin and anti-tetanus serum were administered and polyionic perfusions provided. In addition, the goat was vaccinated against tetanus. The goat and one calf fully recovered after 36 and 8 days respectively. To the authors' knowledge a tetanus outbreak in association with thermal dehorning has not been described previously. Also ear tagging as a possible cause for C. tetani infection has not been described in goats

Draft genome sequences of two commensal <i>Enterococcus cecorum</i> strains isolated from chickens in Belgium

Here, we report the draft genome sequences of two commensal Enterococcus cecorum strains (1710s23 and 1711s24), cultivated from the ceca of healthy laying hens originating from different farms in Belgium

Autonomous Agents Modelling Other Agents: A Comprehensive Survey and Open Problems

Much research in artificial intelligence is concerned with the development of autonomous agents that can interact effectively with other agents. An important aspect of such agents is the ability to reason about the behaviours of other agents, by constructing models which make predictions about various properties of interest (such as actions, goals, beliefs) of the modelled agents. A variety of modelling approaches now exist which vary widely in their methodology and underlying assumptions, catering to the needs of the different sub-communities within which they were developed and reflecting the different practical uses for which they are intended. The purpose of the present article is to provide a comprehensive survey of the salient modelling methods which can be found in the literature. The article concludes with a discussion of open problems which may form the basis for fruitful future research.Comment: Final manuscript (46 pages), published in Artificial Intelligence Journal. The arXiv version also contains a table of contents after the abstract, but is otherwise identical to the AIJ version. Keywords: autonomous agents, multiagent systems, modelling other agents, opponent modellin

Perspectives for improvement of Mycoplasma hyopneumoniae vaccines in pigs.

Mycoplasma hyopneumoniae (M. hyopneumoniae) is one of the primary agents involved in the porcine respiratory disease complex, economically one of the most important diseases in pigs worldwide. The pathogen adheres to the ciliated epithelium of the trachea, bronchi, and bronchioles, causes damage to the mucosal clearance system, modulates the immune system and renders the animal more susceptible to other respiratory infections. The pathogenesis is very complex and not yet fully understood. Cell-mediated and likely also mucosal humoral responses are considered important for protection, although infected animals are not able to rapidly clear the pathogen from the respiratory tract. Vaccination is frequently practiced worldwide to control M. hyopneumoniae infections and the associated performance losses, animal welfare issues, and treatment costs. Commercial vaccines are mostly bacterins that are administered intramuscularly. However, the commercial vaccines provide only partial protection, they do not prevent infection and have a limited effect on transmission. Therefore, there is a need for novel vaccines that confer a better protection. The present paper gives a short overview of the pathogenesis and immune responses following M. hyopneumoniae infection, outlines the major limitations of the commercial vaccines and reviews the different experimental M. hyopneumoniae vaccines that have been developed and tested in mice and pigs. Most experimental subunit, DNA and vector vaccines are based on the P97 adhesin or other factors that are important for pathogen survival and pathogenesis. Other studies focused on bacterins combined with novel adjuvants. Very few efforts have been directed towards the development of attenuated vaccines, although such vaccines may have great potential. As cell-mediated and likely also humoral mucosal responses are important for protection, new vaccines should aim to target these arms of the immune response. The selection of proper antigens, administration route and type of adjuvant and carrier molecule is essential for success. Also practical aspects, such as cost of the vaccine, ease of production, transport and administration, and possible combination with vaccines against other porcine pathogens, are important. Possible avenues for further research to develop better vaccines and to achieve a more sustainable control of M. hyopneumoniae infections are discussed

Associations of barn air quality parameters with ultrasonographic lung lesions, airway inflammation and infection in group-housed calves

Barn climate is believed to play a major role in the bovine respiratory disease complex. However, the exact air quality parameters associated with (sub)clinical pneumonia or airway inflammation in calves are currently unknown. The objective of this cross-sectional study was to assess associations of air quality parameters with clinical signs, lung consolidation, pulmonary inflammation and infection in group-housed calves. In total, 60 beef and dairy farms were visited from January to April 2017 and 428 calves sampled. Measured air quality parameters included continuous 24-h measurements of ammonia concentration, relative humidity and temperature and punctual measurements of air velocity, ammonia, CO2 and bacterial air load. Calf sampling consisted of clinical examination, thoracic ultrasonography and broncho-alveolar lavage sampling for bacteriological and cytological analysis of broncho-alveolar lavage fluid (BALf). Average air temperature was 14.2 degrees C (standard deviation (SD) 4.4, range 5.5-23.9) and relative humidity 68.8 % (SD 8.9, range 52.2-91.6). Average ammonia concentration was 1.7 ppm (SD 0.9, range 0-10.0). Lung consolidations of >= 1 cm, >= 3 cm and >= 6 cm in depth were present in 41.1 % (176/428), 27.1 % (116/428) and 16.1 % (69/428) of the calves, respectively. Average pen temperature was positively associated with consolidations of >= 1 cm (P = 0.005), >= 3 cm (P = 0.002) and >= 6 cm (P 4 ppm, was associated with lung consolidation >= 1 cm (odds ratio (OR) = 1.73; confidence interval (CI) = 1.02-3.07; P = 0.04). Ammonia concentration was positively associated with BALf epithelial cell percentage (P= 0.01). Air velocity> 0.8 m/s was associated with increased odds of lung consolidation of >= 3 cm (OR= 6.8; CI= 1.2-38.5; P= 0.04) and >= 6 cm (OR = 15.9; CI = 1.2-200.0; P = 0.03). The prevalence of lung consolidations >= 1 cm was higher in the draught (81.8 %; P = 0.0092) and warm, dry and ammonia accumulation clusters (54.2 %; P = 0.02) compared to the presumably normal cluster (31.6 %). In addition, in the warm, dry and ammonia cluster the prevalence of lung consolidations >= 3 cm (38.1 %; P = 0.04) and >= 6 cm (31.4 %; P = 0.01) in depth were higher compared to the presumably normal climate cluster (18.2 % and 9.1 %, respectively). Of all frequently measured indoor air quality parameters, only average temperature, ammonia concentration and air velocity were associated with pneumonia and might therefore be preferable for cost-effective evaluation of calf barn climate

In vitro characterization of bovine neutrophil cell death following Escherichia coli phagocytosis

Neutrophils are known to play a key role in the early host defense towards coliform mastitis. The molecular events during phagocytosis-induced cell death (PICD) are rarely described, especially for bovine neutrophils. Therefore, our objective was to elucidate the type of cell death of bovine neutrophils after in vitro phagocytosis of Escherichia coli. Peripheral blood samples were collected from clinically healthy heifers. Neutrophils were isolated by density gradient centrifugation, resuspended in RPMI with 10 % fcs and incubated with E. coli strain P4:O32 (moi 5:1) at 37°C. PS exposure and cell membrane integrity loss was determined flow cytometrically by Annexin-V-FITC/PI. ROS were measured as luminol-amplified chemiluminescence. Equal amounts of total cell lysates were analyzed by western blotting using anti caspase-1 (C-1), cleaved C-3 and C-7 and X-IAP. C-3/-7 activity was determined using the caspase-Glo®assay and bovine IL-1β was quantified with ELISA. The higher rate of PS exposure in activated than in control neutrophils undergoing spontaneous apoptosis, indicates that bovine neutrophil cell death is accelerated following phagocytosis of E. coli, as recently described. In contrast to control cells, PICD occurred with significant ROS production but independent from C-3/-7 activation. The latter finding is in line with a recent report describing caspase-independent cell death of human neutrophils incubated with E. coli, although no ROS production was seen. In both human and mouse neutrophils, NADPH oxidase prevents caspase activation following phagocytosis of S. aureus. Nevertheless, all these data do not corroborate a study with human neutrophils incubated with E. coli where C-3 activation was demonstrated. This discrepancy could be either species and/or micro-organism related. Interestingly, the well-described X-IAP inhibitor for C-3 and C-7, was only present in control samples, suggesting that X-IAP may control C-3/-7 activity in spontaneous bovine neutrophil apoptosis but is superfluous in E. coli PICD in vitro. Life cell imaging using GFP-labeled E. coli and PI staining showed no clear morphological features of either netosis or autophagy, but late PI positivity and membrane blebbing without apoptotic bodies. Complementing these features with C-1 activation and intracellular IL-1β suggests that the PICD in our setup is executed by pyroptosis. Taken together, our in vitro data indicate that bovine neutrophils undergo C-3/-7-assisted spontaneous apoptosis and that E. coli stimulated PICD most likely can be characterized as C-3/-7-independent, but C-1- and ROS-dependent pyroptosis

Cavity ring-down spectroscopy of metallic gold nanoparticles

The optical properties of supported gold nanoparticles with sizes of 1.3 nm, 1.6 nm, 2.5 nm, and 2.9 nm have been studies by using cavity ring-down spectroscopy in the photon energy range between 1.8 eV and 3.0 eV. The obtained results show the possibility to obtain optical information of nanoassembled materials with high sensitivity. The experimental findings are compared to calculations using Mie-Drude theory. Whereas the broadening of the surface plasmon resonance with decreasing size is well described by this model, the observed blue-shift of the surface plasmon resonance contradicts the predictions of the Mie-Drude theory. The latter effect can be explained by the presence of a skin region with decreased polarizability typical for coinage metal particles. Furthermore, it is found that the supported gold nanoparticles are robust under ambient conditions, an important issue when using these materials for optical applications