Estimating Diagnostic Test Accuracies for Brachyspira hyodysenteriae Accounting for the Complexities of Population Structure in Food Animals

For swine dysentery, which is caused by Brachyspira hyodysenteriae infection and is an economically important disease in intensive pig production systems worldwide, a perfect or error-free diagnostic test ("gold standard") is not available. In the absence of a gold standard, Bayesian latent class modelling is a well-established methodology for robust diagnostic test evaluation. In contrast to risk factor studies in food animals, where adjustment for within group correlations is both usual and required for good statistical practice, diagnostic test evaluation studies rarely take such clustering aspects into account, which can result in misleading results. The aim of the present study was to estimate test accuracies of a PCR originally designed for use as a confirmatory test, displaying a high diagnostic specificity, and cultural examination for B. hyodysenteriae. This estimation was conducted based on results of 239 samples from 103 herds originating from routine diagnostic sampling. Using Bayesian latent class modelling comprising of a hierarchical beta-binomial approach (which allowed prevalence across individual herds to vary as herd level random effect), robust estimates for the sensitivities of PCR and culture, as well as for the specificity of PCR, were obtained. The estimated diagnostic sensitivity of PCR (95% CI) and culture were 73.2% (62.3; 82.9) and 88.6% (74.9; 99.3), respectively. The estimated specificity of the PCR was 96.2% (90.9; 99.8). For test evaluation studies, a Bayesian latent class approach is well suited for addressing the considerable complexities of population structure in food animals.

Use of antimicrobials in food-producing animals in Switzerland and in the European Union (EU)

The intensive and inappropriate use of antibiotics in both medicine and agriculture has selected for antibiotic resistant bacteria that cause severe problems in antibiotic therapy. In animal husbandry, antibiotics are used for therapeutic and preventive treatments of infectious diseases and as growth promoters. In Europe, many antibiotics used as growth promoters were of the same classes as important antibiotics used in human medicine. The European Union withdrew the authorization for the use of the major antimicrobial growth promoters between 1996 and 1999. In 1999 Switzerland decided to ban the use of all antimicrobials as growthpromoting feed additives. The regulations concerning antibiotic use in animal husbandry and the chronological reasons for the ban of antimicrobial growth promoters are described. This ban led to a decrease of the antibiotic volume deployed in agriculture. This measure helps to reduce the amount of antibiotic resistant bacteria in food-producing animals. However, the use of medicated feed is still a common practice to prevent and to remedy bacterial infections and thus still leads to resistant pathogens. Surveillance programs, single animal treatment, good manufacturing practices and vaccinations are additional measures to be taken to keep the level of resistances in bacteria low.

Third-Generation-Cephalosporin-Resistant Klebsiella pneumoniae Isolates from Humans and Companion Animals in Switzerland: Spread of a DHA-Producing Sequence Type 11 Clone in a Veterinary Setting.

Characterization of third-generation-cephalosporin-resistant Klebsiella pneumoniae isolates originating mainly from one human hospital (n = 22) and one companion animal hospital (n = 25) in Bern (Switzerland) revealed the absence of epidemiological links between human and animal isolates. Human infections were not associated with the spread of any specific clone, while the majority of animal infections were due to K. pneumoniae sequence type 11 isolates producing plasmidic DHA AmpC. This clonal dissemination within the veterinary hospital emphasizes the need for effective infection control practices.

Best practices and innovative capacity development approaches in ARD programmes of ERA-ARD consortium members: Draft compilation of National Contribution

In the framework of the European Research Area for Agricultural Research for Development (ERA-ARD) project, a survey of innovative approaches in capacity development (CD) was undertaken. All Consortium members were asked to describe innovative approaches and best practices of CD mechanisms within their ARD programmes. A tabular overview of all the programmes or mechanisms can be found on page 4. Abstracts of the programmes or mechanisms are compiled in alphabetic order of the consortium members in this document. The intention of this catalogue of mechanisms is to give an overview of different approaches and practices and not to provide a comprehensive mapping of all the ongoing CD activities of the Consortium members. Thus, the programmes described represent only a fraction of all the ongoing CD programmes on the national level.

Schnidejoch (2756 m a.s.l., Western Bernese Alps, Switzerland). Did Holocene glacier advances close the alpine pass for human transhumance?

A series of more than 70 radiocarbon dates confirms that the Schnidejoch pass, linking the Bernese Highlands with the River Rhone valley, was in use at least from 4800–4500 BC on. The pass was of easy access when the glaciers from the nearby Wildhorn mountain range (peak on 3248 a.s.l) were in a retreating phase e.g. as is the situation today. During holocene phases of advancing glaciers the pass was blocked for humans accompanied by herding animals. The presentation reviews the publication of Grosjean et al. (Ice-borne prehistoric finds in the Swiss Alps reflect Holocene glacier fluctuations, JOURNAL OF QUATERNARY SCIENCE, 200, 22.3, 203–207) on a larger basis of radiocarbon dating and discusses the position of the pass within a system of prehistoric settlements, camp sites and passes.

Functional proteomics and biochemistry: working together to unravel mitochondrial phenomena of African trypanosomes

Eukaryotic cells are compartmentalized into membrane-bound organelles in order to provide sheltered reaction rooms for various specific processes. Organelles are not randomly distributed in a cell or operate isolated from each other. At the contrary — some organelles are closely linked and their functions are tightly orchestrated. The most well-known example of two such organelles acting in concert are the ER and the mitochondrion that work together in order to coordinate cellular lipid biosynthesis, maintain Ca2+-homeostasis, regulate mitochondrial division and control mitochondrial/ER shape as well as to synchronize the movement of these organelles within a cell. To study the mitochondrion and its interface to the ER requires a simplified mitochondrial system. African trypanosomes represent such a system. The unicellular parasite that causes devastating diseases in humans and animals has only one large mitochondrion that does not undergo fission/fusion events except for the context of cell division. Moreover, mitochondrial functions and morphology are highly regulated throughout the life cycle of the protozoan. Central to the understanding of how mitochondria control their morphology, communicate with their surroundings and manage exchange of metabolites and transport of biopolymers (proteins, RNAs) is the mitochondrial outer membrane (MOM), as the MOM defines the boundary of the organelle. Recently, we have purified the MOM of T. brucei and characterized its proteome using label-free quantitative mass spectrometry for protein abundance profiling in combination with statistical analysis. Our results show that the trypanosomal MOM proteome consists of 82 proteins, two thirds of which have never been associated with mitochondria before. Among these, we identified novel factors required to regulate mitochondrial morphology and the long-elusive protein import machinery of T. brucei. A comparison with the MOM proteome of yeast defines a set of 17 common proteins that are likely present in the mitochondrial outer membrane of all eukaryotes. One of these is the Miro-GTPase Gem1. In yeast, this Ca2+-EF-Hand containing polypeptide is thought to be involved in a protein complex that physically tethers the mitochondrion to the ER. Interestingly, a putative tethering complex in mammalian cells was linked to the mitochondrial fusion/fission machinery. Thus, the concept of a protein complex-mediated connection seems to be a general and conserved feature. We are currently investigating, if such a protein complex exists in T. brucei and if the trypanosomal Gem1 protein is involved. This ER-subdomain associated with mitochondria has been termed mitochondria-associated ER-membranes or MAM. The MAM has recently been implicated to play a key role in Alzheimer’s disease. It is therefore of broad and general interest to establish other eukaryotic model systems in order to investigate the MAM-MOM connection in more detail.

Defensin Levels in Spider Hemolymph

Spiders, like all arthropods, exclusively rely on an innate immune system localized in the hemocytes to protect against pathogen invasion. In the hemocytes of the wandering spider Cupiennius salei (C. salei), defensin expression was found to be constitutive. Defensins belong to the group of antimicrobial peptides, which appear in most taxonomic groups, and play an essential role in innate immunity. It has further been reported that during the primary immune answer of C. salei, the peptide content of hemocytes changes markedly, which may indicate the release of defensins from the hemocytes. However, no data on the peptide levels in C. salei hemolymph has so far been published. Formerly, the involvement in the primary immune answer was considered the only function of defensins. However, recent findings strongly suggest that the importance of defensins goes far beyond. There is evidence for defensins contributing to the adaptive immune response, to angiogenesis, and furthermore to tissue repair, i.e. to a variety of essential processes in living organisms. To date, only very little is known about the identity of C. salei defensins and their detailed mode of action. The goal of the work presented herein is the identification of hitherto unknown C. salei defensins in hemocytes and the hemolymph. Moreover, the levels of defensin expression under differential conditions are compared by the means of liquid chromatography-tandem mass spectrometry (LC-MS/MS).

Intervertebral Disc Repair using Fleece-Membrane Composite Silk Material and Genipin-enhanced Fibrin Hydrogel

Introduction: Treating low back pain (LBP) has become an increasing challenge, as it is one of the main factors causing pain and is accompanied by high costs for the individual and the society. LBP can be caused by trauma of the intervertebral disc (IVD) or IVD degeneration. In the case of disc herniation the inner gelatinous part of the IVD, called nucleus pulposus, is pressed through the fibrous, annulus fibrosus that forms the outer part of the IVD. Today’s gold standard for treatment is extensive surgery as removal of the IVD and fusion of the vertebrae. In order to find a more gentle way to treat LBP and restore the native IVD we use a novel silk fleece-membrane composite from genetically modified silk worms whose silk contains a growth factor (GDF-6) that is associated with pushing stem cells towards a disc like phenotype (1). By combining it with a genipin-enhanced fibrin hydrogel we tested its suitability in organ culture on prior injured bovine IVD in our custom built two-degree of freedom bioreactor to mimic natural loading conditions. Material & Methods: Bovine IVDs of 12-17 months old animals were isolated by first removing all surrounding tissue followed by cutting out the IVDs as previously described (2). Culturing of discs occurred in high glucose Dulbecco's Modified Eagle Medium (HG-DMEM) supplemented with 5% serum as previously described (2). On the next day injury was induced using a 2mm biopsy punch (Polymed, Switzerland). The formed cavity was filled with (0.4%) genipin-enhanced human based fibrin hydrogel (35-55mg/mL human fibrinogen, Baxter, Austria) and sealed with a silk fleece-membrane composite (Spintec Engineering, Germany). Different culture conditions were applied: free swelling, static diurnal load of 0.2MPa for 8h/d and complex loading at 0.2MPa compression combined with ± 2° torsion at 0.2Hz for 8h/d (2). After 14 days of culture cell activity was determined with resazurin assay. Additionally, glycosaminoglycan (dimethyl-methylene blue), DNA (Hoechst) and collagen content (hydroxy- proline) were determined. Finally, real-time qPCR of major IVD marker and inflammation genes was performed to judge integrity of IVDs. Results: The fibrin hydrogel is able to keep the silk seal in place throughout the 14 days of in organ culture under all conditions. Additionally, cell activity showed optimistic results and we could not confirm negative effects of the repaired discs regarding overexpression of inflammation markers. Conclusions: The genipin-enhanced fibrin hydrogel in combination with the silk fleece- membrane composite seems to be a promising approach for IVD repair. Currently we assess the capability of GDF-6 incorporated in our silk composites on human mesenchymal stem cells and later on in organ culture. References 1. Clarke LE, McConnell JC, Sherratt MJ, Derby B, Richardson SM, Hoyland JA. Growth differentiation factor 6 and transforming growth factor-beta differentially mediate mesenchymal stem cell differentiation, composition and micromechanical properties of nucleus pulposus constructs. Arthritis Res Ther 2014, Mar 12;16(2):R67. 2. Chan SC, Gantenbein-Ritter B. Preparation of intact bovine tail intervertebral discs for organ culture. J Vis Exp 2012, Feb 2;60(60):e3490. Acknowledgements. This work is funded by the Gebert Rüf Foundation, project number GRS-028/13.

High quality draft genomes of the Mycoplasma mycoides subsp. mycoides challenge strains Afadé and B237.

Members of the Mycoplasma mycoides cluster' represent important livestock pathogens worldwide. Mycoplasma mycoides subsp. mycoides is the etiologic agent of contagious bovine pleuropneumonia (CBPP), which is still endemic in many parts of Africa. We report the genome sequences and annotation of two frequently used challenge strains of Mycoplasma mycoides subsp. mycoides, Afadé and B237. The information provided will enable downstream 'omics' applications such as proteomics, transcriptomics and reverse vaccinology approaches. Despite the absence of Mycoplasma pneumoniae like cyto-adhesion encoding genes, the two strains showed the presence of protrusions. This phenotype is likely encoded by another set of genes.

The Face of Power

Objective: In humans and other animals, open, expansive postures (compared to contracted postures) are evolutionary developed expressions of power and have been shown to cause neuroendocrine and behavioral changes (Carney, Cuddy, & Yap, 2010). In the present study we aimed to investigate whether power postures have a bearing on the participant’s facial appearance and whether others are able to distinguish faces after “high power posing” from faces after “low power posing”. Methods: 16 models were photographed 4-5 minutes after having adopted high and low power postures. Two different high power and two different low power postures were held for 2 minutes each. Power-posing sessions were performed on two consecutive days. High and low power photographs of each model were paired and an independent sample of 100 participants were asked to pick the more dominant and the more likeable face of each pair. Results: Photographs that were taken after adopting high power postures were chosen significantly more often as being more dominant looking. There was no preference when asked to choose the more likeable photograph (chance level). A further independent sample rated each photograph for head tilt, making it unlikely that dominance ratings were caused merely by the posture of the head. Consistently, facial width-to-height ratio did not differ between faces after high and low power posing. Conclusions: Postures associated with high power affect facial appearance, leading to a more dominant looking face. This finding may have implications for everyday life, for instance when a dominant appearance is needed.

Cloning Animals by Somatic Cell Nuclear Transfer--Biological Factors

Cloning by nuclear transfer using mammalian somatic cells has enormous potential application. However, somatic cloning has been inefficient in all species in which live clones have been produced. High abortion and fetal mortality rates are commonly observed. These developmental defects have been attributed to incomplete reprogramming of the somatic nuclei by the cloning process. Various strategies have been used to improve the efficiency of nuclear transfer, however, significant breakthroughs are yet to happen. In this review we will discuss studies conducted, in our laboratories and those of others, to gain a better understanding of nuclear reprogramming. Because cattle are a species widely used for nuclear transfer studies, and more laboratories have succeeded in cloning cattle than any other species, this review will be focused on somatic cell cloning of cattle.