Exudative glomerulonephritis associated with acute leptospirosis in dogs.

In the past 20 years in Switzerland, dogs with suspect acute leptospirosis frequently showed severe glomerular changes that had not been previously reported. These features were characterized by abundant extravasated erythrocytes and fewer neutrophils accompanied by marked fibrin exudation into the urinary space that was interpreted as an exudative glomerulonephritis (GN). This retrospective study describes this significant glomerular pathological change and investigates the association with leptospirosis.

Reverse Genetic Assessment of the Roles Played by the Spike Protein and ORF3 in Porcine Epidemic Diarrhea Virus Pathogenicity.

Porcine epidemic diarrhea virus is a swine pathogen that has been responsible for significant animal and economic losses worldwide in recent years. In this manuscript, we report the generation of a reverse genetics system C(RGS) for the highly virulent US PEDV strain Minnesota (PEDV-MN; GenBank accession number KF468752), which was based on the assembly and cloning of synthetic DNA, using vaccinia virus as a cloning vector. Viral rescue was only possible following the substitution of 2 nucleotides within the 5'UTR and 2 additional nucleotides within the spike gene, based on the sequence of the cell culture-adapted strains.

Cryo-EM structure of the octameric pore of Clostridium perfringens β-toxin.

Clostridium perfringens is one of the most widely distributed and successful pathogens producing an impressive arsenal of toxins. One of the most potent toxins produced is the C. perfringens β-toxin (CPB).

The baseline immunological and hygienic status of pigs impact disease severity of African swine fever.

African Swine Fever virus (ASFV) is a large double-enveloped DNA virus of the Asfarviridae family that causes a lethal hemorrhagic disease in domestic pigs and wild boars. Since 2007, a highly virulent genotype II strain has emerged and spread in Europe and South-East Asia, where millions of animals succumbed to the disease. Field- and laboratory-attenuated strains of ASFV cause highly variable clinical disease severity and survival, and mechanisms remain unclear.

Establishment of well-differentiated camelid airway cultures to study Middle East respiratory syndrome coronavirus.

In 2012, Middle East respiratory syndrome coronavirus (MERS-CoV) emerged in Saudi Arabia and was mostly associated with severe respiratory illness in humans. Dromedary camels are the zoonotic reservoir for MERS-CoV. To investigate the biology of MERS-CoV in camelids, we developed a well-differentiated airway epithelial cell (AEC) culture model for Llama glama and Camelus bactrianus.

Pathology in Practice.

In collaboration with the American College of Veterinary Pathologists.

Platelet Endothelial Cell Adhesion Molecule 1 (CD31) Is Essential for Beta-Toxin Mediated Cytotoxicity in Human Endothelial and Monocytic Cells.

Beta toxin (CPB) is a small hemolysin beta pore-forming toxin (β-PFT) produced by type C. It plays a central role in the pathogenesis of necro-hemorrhagic enteritis in young animals and humans via targeting intestinal endothelial cells. We recently identified the membrane protein CD31 (PECAM-1) as the receptor for CPB on mouse endothelial cells.

Pulmonary mesenchymal stem cells are engaged in distinct steps of host response to respiratory syncytial virus infection.

Lung-resident (LR) mesenchymal stem and stromal cells (MSCs) are key elements of the alveolar niche and fundamental regulators of homeostasis and regeneration. We interrogated their function during virus-induced lung injury using the highly prevalent respiratory syncytial virus (RSV) which causes severe outcomes in infants. We applied complementary approaches with primary pediatric LR-MSCs and a state-of-the-art model of human RSV infection in lamb.

Susceptibility of Well-Differentiated Airway Epithelial Cell Cultures from Domestic and Wild Animals to Severe Acute Respiratory Syndrome Coronavirus 2.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread globally, and the number of worldwide cases continues to rise. The zoonotic origins of SARS-CoV-2 and its intermediate and potential spillback host reservoirs, besides humans, remain largely unknown. Because of ethical and experimental constraints and more important, to reduce and refine animal experimentation, we used our repository of well-differentiated airway epithelial cell (AEC) cultures from various domesticated and wildlife animal species to assess their susceptibility to SARS-CoV-2.

The specific features of the developing T cell compartment of the neonatal lung are a determinant of respiratory syncytial virus immunopathogenesis.

The human respiratory syncytial virus (RSV) is a major cause of severe lower respiratory tract infections in infants, possibly due to the properties of the immature neonatal pulmonary immune system. Using the newborn lamb, a classical model of human lung development and a translational model of RSV infection, we aimed to explore the role of cell-mediated immunity in RSV disease during early life. Remarkably, in healthy conditions, the developing T cell compartment of the neonatal lung showed major differences to that seen in the mature adult lung.

Pulmonary Artery Aneurysm in a Greater Flamingo (Phoenicopterus roseus) Associated with Aspergillus fumigatus Infection.

We report necropsy findings in a captive 60-year-old female greater flamingo (Phoenicopterus roseus) that died suddenly following rupture of a pulmonary artery aneurysm. Histologically, there was focally extensive, intramural granulomatous inflammation with intralesional fungal hyphae, and adjacent severe mixed-cell inflammation and acute haemorrhage at the rupture site. Aspergillus fumigatus was identified as the aetiological agent following DNA PCR amplification and sequencing from paraffin-embedded pulmonary artery tissue sections.

-Associated Necrotic Enteritis-Like Disease in Coconut Lorikeets ().

Several outbreaks of necrotic enteritis-like disease in lorikeets, from which was consistently isolated, are described. All lorikeets had acute, segmental, or multifocal fibrinonecrotizing inflammatory lesions in the small and/or the large intestine, with intralesional gram-positive rods. The gene encoding alpha toxin was detected by PCR (polymerase chain reaction) on formalin-fixed, paraffin-embedded (FFPE) tissues in 20 out of 24 affected lorikeets (83%), but it was not amplified from samples of any of 10 control lorikeets ( < .

Reproduction of contagious bovine pleuropneumonia via aerosol-based challenge with Mycoplasma mycoides subsp. mycoides.

Contagious bovine pleuropneumonia (CBPP) is a respiratory disease caused by Mycoplasma mycoides subsp. mycoides. Infection occurs via Mycoplasma-containing droplets and therefore requires close contact between animals.

CD31 (PECAM-1) Serves as the Endothelial Cell-Specific Receptor of Clostridium perfringens β-Toxin.

Clostridium perfringens β-toxin (CPB) is a highly active β-pore-forming toxin (β-PFT) and the essential virulence factor for fatal, necro-hemorrhagic enteritis in animals and humans. The molecular mechanisms involved in CPB's action on its target, the endothelium of small intestinal vessels, are poorly understood. Here, we identify platelet endothelial cell adhesion molecule-1 (CD31 or PECAM-1) as the specific membrane receptor for CPB on endothelial cells.

type C necrotic enteritis in pigs: diagnosis, pathogenesis, and prevention.

type C causes severe and lethal necrotic enteritis (NE) in newborn piglets. NE is diagnosed through a combination of pathology and bacteriologic investigations. The hallmark lesion of NE is deep, segmental mucosal necrosis with marked hemorrhage of the small intestine.

Vaccination against type C enteritis in pigs: a field study using an adapted vaccination scheme.

Background: type C induced necrotizing enteritis (NE) causes high mortality in newborn piglets. Immunization programs employing commercially available vaccines are used to prevent disease. Sows are vaccinated during every gestation period and piglets take up antibodies from the colostrum.

ALVEOLAR ECHINOCOCCOSIS IN WESTERN LOWLAND GORILLAS (): ALBENDAZOLE WAS NOT ABLE TO STOP PROGRESSION OF THE DISEASE.

is the etiologic agent of alveolar echinococcosis (AE), a severe and potentially fatal larval cestode infection primarily affecting the liver. AE is known to occur in dead-end intermediate hosts, including humans and nonhuman primates. Between 1999 and 2016, AE was diagnosed in seven western lowland gorillas (), all from a Swiss zoo.

Attenuation of a Pathogenic Strain by Modification of the Gene by Using Synthetic Biology Approaches.

species are responsible for several economically significant livestock diseases for which there is a need for new and improved vaccines. Most of the existing mycoplasma vaccines are attenuated strains that have been empirically obtained by serial passages or by chemical mutagenesis. The recent development of synthetic biology approaches has opened the way for the engineering of live mycoplasma vaccines.

Removal of a Subset of Non-essential Genes Fully Attenuates a Highly Virulent Strain.

Mycoplasmas are the smallest free-living organisms and cause a number of economically important diseases affecting humans, animals, insects, and plants. Here, we demonstrate that highly virulent subspecies () can be fully attenuated targeted deletion of non-essential genes encoding, among others, potential virulence traits. Five genomic regions, representing approximately 10% of the original genome, were successively deleted using as an engineering platform.

Application of an Endothelial Cell Culture Assay for the Detection of Neutralizing Anti-Clostridium Perfringens Beta-Toxin Antibodies in a Porcine Vaccination Trial.

Beta-toxin (CPB) is the major virulence factor of type C, causing hemorrhagic enteritis in newborn pigs but also other animals and humans. Vaccines containing inactivated CPB are known to induce protective antibody titers in sow colostrum and neutralization of the CPB activity is thought to be essential for protective immunity in newborn piglets. However, no method is available to quantify the neutralizing effect of vaccine-induced antibody titers in pigs.

In vivo role of capsular polysaccharide in Mycoplasma mycoides.

Capsular polysaccharides have been confirmed to be an important virulence trait in many gram-positive and gram-negative bacteria. Similarly, they are proposed to be virulence traits in minimal Mycoplasma that cause disease in humans and animals. In the current study, goats were infected with the caprine pathogen Mycoplasma mycoides subsp.

Observational Study Design in Veterinary Pathology, Part 2: Methodology.

Observational studies are a basis for much of our knowledge of veterinary pathology, yet considerations for conducting pathology-based observational studies are not readily available. In part 1 of this series, we offered advice on planning and carrying out an observational study. Part 2 of the series focuses on methodology.

Bacillus anthracis as a cause of bovine abortion - a necropsy case requiring special biosafety measures.

In spring 2017, the first case of bovine anthrax in 20 years in Switzerland occurred in the canton of Jura. Carcasses of anthrax-deceased animals should not be opened due to the formation of highly resistant spores bearing the risk of environmental contamination and aerosolization. Nevertheless, in the course of this local outbreak, one sick cow from the affected farm, whose blood repeatedly tested negative for Bacillus anthracis, was necropsied after euthanasia under special biosafety precautions at the Institute of Animal Pathology, Vetsuisse-Faculty Bern.

Observational Study Design in Veterinary Pathology, Part 1: Study Design.

Observational studies are the basis for much of our knowledge of veterinary pathology and are highly relevant to the daily practice of pathology. However, recommendations for conducting pathology-based observational studies are not readily available. In part 1 of this series, we offer advice on planning and conducting an observational study with examples from the veterinary pathology literature.