Sandra Högler

Novel Avian Bornavirus in a Nonpsittacine Species (Canary; Serinus canaria) with Enteric Ganglioneuritis and Encephalitis

ABSTRACT A canary bird (Serinus canaria) died with nonsuppurative ganglioneuritis of the proventriculus and gizzard and encephalitis, lesions comparable to proventricular dilatation disease (PDD) of psittacine birds. Recently, several genotypes of a novel avian bornavirus have been linked to PDD. In the canary, bornaviral antigen was detected by immunohistochemistry in both neural and extraneural tissues. The widespread viral dissemination was confirmed by reverse transcription-PCR. Sequence analysis revealed a unique genotype of avian bornavirus. This observation suggests that bornaviruses are natural pathogens of several avian species and that the family Bornaviridae comprises more viral genotypes (or viral species) than previously assumed.

Congenital infection with atypical porcine pestivirus (APPV) is associated with disease and viral persistence

In 2013, several Austrian piglet-producing farms recorded outbreaks of action-related repetitive myoclonia in newborn piglets (“shaking piglets”). Malnutrition was seen in numerous piglets as a complication of this tremor syndrome. Overall piglet mortality was increased and the number of weaned piglets per sow decreased by more than 10% due to this outbreak. Histological examination of the CNS of affected piglets revealed moderate hypomyelination of the white substance in cerebellum and spinal cord. We detected a recently discovered pestivirus, termed atypical porcine pestivirus (APPV) in all these cases by RT-PCR. A genomic sequence and seven partial sequences were determined and revealed a 90% identity to the US APPV sequences and 92% identity to German sequences. In confirmation with previous reports, APPV genomes were identified in different body fluids and tissues including the CNS of diseased piglets. APPV could be isolated from a “shaking piglet”, which was incapable of consuming colostrum, and passaged on different porcine cells at very low titers. To assess the antibody response a blocking ELISA was developed targeting NS3. APPV specific antibodies were identified in sows and in PCR positive piglets affected by congenital tremor (CT). APPV genomes were detected continuously in piglets that gradually recovered from CT, while the antibody titers decreased over a 12-week interval, pointing towards maternally transmitted antibodies. High viral loads were detectable by qRT-PCR in saliva and semen of infected young adults indicating a persistent infection.

Distribution of neuropathological lesions in pig brains after different durations of cardiac arrest

AIM OF THE STUDY To evaluate all brain regions reported to be selectively vulnerable to global ischaemia in a pig cardiac arrest model with different durations of no-flow by establishing a semi-quantitative brain histopathologic scoring system and to compare histological damage with neurological deficits. METHODS In a prospective randomised laboratory investigation, 35 female Large White pigs weighing 35-45 kg underwent ventricular fibrillation cardiac arrest for 0, 7, 10 or 13 min. In the brains of all animals that survived until the final endpoint (72 h post-arrest), 22 distinct regions were evaluated on paraffin-embedded sections in terms of type and extent of lesions. The results of the histological examination were compared to the results of a neurological outcome evaluation after 72 h. RESULTS Significant differences were found in all cortex regions, the caudate nucleus and putamen, the hippocampal formation, the cerebellar cortex, and the thalamus between the ischaemic groups (7- and 10-min groups) and the control group (0-min group). No 13-min group animal survived. The main findings were neuronal necrosis and oedema. In animals from the 10-min group, many neurons were reabsorbed in the cerebral cortex, caudate nucleus and cerebellar granule cell layer. There was a highly significant correlation between histological damage and neurological deficits. CONCLUSIONS The pattern of neuronal lesions in this pig model bear good resemblance to the pattern known in humans and other animal models. The amount of histological lesions in selectively vulnerable brain regions correlates to neurological outcome.

Benign intrapericardial lipoma in a dog.

SUMMARY Canine lipomas generally develop in subcutaneous tissue. Intrapericardial lipomas are extremely rare benign tumours and can develop on the pericardial surface of the heart or inside the cardiac chambers. As the thoracic cavity is an unusual site for lipomas in dogs, we describe, clinically and pathologically, a case of intrapericardial lipoma in an 18-months old German Shepherd.

Novel Pestivirus Species in Pigs, Austria, 2015

A novel pestivirus species was discovered in a piglet-producing farm in Austria during virologic examinations of congenital tremor cases. The emergence of this novel pestivirus species, provisionally termed Linda virus, in domestic pigs may have implications for classical swine fever virus surveillance and porcine health management.

Outcome after resuscitation using controlled rapid extracorporeal cooling to a brain temperature of 30 ◦ C, 24 ◦ C and 18 ◦ C during cardiac arrest in pigs ,

AIM OF THE STUDY To identify the optimal level of hypothermia during cardiac arrest, just prior to resuscitation with an extracorporeal cooling system and without fluid overload, for neurological outcome at day 9 in pigs. METHODS In a prospective randomised laboratory investigation, 24 female Large White pigs (31-38 kg) underwent ventricular-fibrillation cardiac arrest for 15 min, followed by 1 min, 3 min or 5 min (n=8 per group) of 4 degrees C cooling with an extracorporeal cooling system via an aortic balloon catheter and resuscitation with cardiopulmonary bypass. Sixty minutes following induction of cardiac arrest, defibrillation attempts were started. Mild hypothermia (34.5 degrees C) and intensive care were continued for 20 h and final outcome was evaluated after 9 days. RESULTS Brain temperature decreased from 38.5 degrees C to 30.4+/-1.6 degrees C within 221+/-81 s in the 1-min group; to 24.2+/-4.6 degrees C within 375+/-127 s in the 3-min group; and to 18.8+/-4.0 degrees C within 450+/-121 s in the 5-min group. Restoration of spontaneous circulation was achieved in seven (1-min group), six (3-min group) and six (5-min group) animals (p=0.78), whereas survival to 9 days was only achieved in six, three and three animals in each group (p=0.22), respectively. CONCLUSIONS An extracorporeal cooling system rapidly induced brain hypothermia following prolonged normovolaemic cardiac arrest in pigs. Difference in outcome was not statistically significant amongst the three groups with various levels of hypothermia (30 degrees C, 24 degrees C and 18 degrees C) during cardiac arrest prior to resuscitation; however, the animals with the least temperature reduction showed a trend to better survival at 9 days. Further studies are necessary to investigate optimised methods for induction, as well as level, of cerebral hypothermia.

Spongy degeneration with cerebellar ataxia in Malinois puppies: a hereditary autosomal recessive disorder?

BACKGROUND There is a high incidence of hereditary degenerative diseases of the central nervous system in purebred dogs. HYPOTHESIS Cerebellar ataxia in Malinois puppies, caused by degenerative changes that predominate in cerebellar nuclei and the granular cell layer, is a hereditary disorder that is distinct from cerebellar cortical abiotrophies. ANIMALS Thirteen Malinois puppies with cerebellar ataxia. METHODS Retrospective study. Records of Malinois puppies with spongy degeneration of the cerebellar nuclei were analyzed including clinical signs, histopathological changes, and pedigree data. RESULTS Signs of cerebellar dysfunction were observed in puppies of both sexes from 5 different litters (1995-2009) of phenotypically normal parents. Clinical signs started before the age of 2 months and resulted in euthanasia of all puppies by the age of 13 weeks. Histopathology disclosed marked bilateral spongy degeneration of the cerebellar nuclei and vacuoles in the granular cell layer and foliate white matter of the cerebellum. In some puppies, discrete vacuoles in gray and white matter were present in other parts of the brain. Furthermore, spheroids and dilated myelin sheaths were observed. Pedigree data and segregation frequency support an autosomal recessive hereditary disorder. CONCLUSIONS AND CLINICAL IMPORTANCE Malinois suffer from a hereditary spongiform degeneration that predominates in the cerebellum and causes an early onset of clinical signs with unfavorable prognosis. Future efforts should increase awareness among veterinarians and breeders and aim to identify underlying metabolic mechanisms and the affected genes.

A Missense Variant in KCNJ10 in Belgian Shepherd Dogs Affected by Spongy Degeneration with Cerebellar Ataxia (SDCA1).

Spongy degeneration with cerebellar ataxia (SDCA) is a severe neurodegenerative disease with monogenic autosomal recessive inheritance in Malinois dogs, one of the four varieties of the Belgian Shepherd breed. We performed a genetic investigation in six families and seven isolated cases of Malinois dogs with signs of cerebellar dysfunction. Linkage analysis revealed an unexpected genetic heterogeneity within the studied cases. The affected dogs from four families and one isolated case shared a ∼1.4 Mb common homozygous haplotype segment on chromosome 38. Whole genome sequence analysis of three affected and 140 control dogs revealed a missense variant in the KCNJ10 gene encoding a potassium channel (c.986T>C; p.Leu329Pro). Pathogenic variants in KCNJ10 were reported previously in humans, mice, and dogs with neurological phenotypes. Therefore, we consider KCNJ10:c.986T>C the most likely candidate causative variant for one subtype of SDCA in Malinois dogs, which we propose to term spongy degeneration with cerebellar ataxia 1 (SDCA1). However, our study also comprised samples from 12 Malinois dogs with cerebellar dysfunction which were not homozygous for this variant, suggesting a different genetic basis in these dogs. A retrospective detailed clinical and histopathological analysis revealed subtle neuropathological differences with respect to SDCA1-affected dogs. Thus, our study highlights the genetic and phenotypic complexity underlying cerebellar dysfunction in Malinois dogs and provides the basis for a genetic test to eradicate one specific neurodegenerative disease from the breeding population. These dogs represent an animal model for the human EAST syndrome.

The Influence of Programmed Cell Death in Myeloid Cells on Host Resilience to Infection with Legionella pneumophila or Streptococcus pyogenes

Pathogen clearance and host resilience/tolerance to infection are both important factors in surviving an infection. Cells of the myeloid lineage play important roles in both of these processes. Neutrophils, monocytes, macrophages, and dendritic cells all have important roles in initiation of the immune response and clearance of bacterial pathogens. If these cells are not properly regulated they can result in excessive inflammation and immunopathology leading to decreased host resilience. Programmed cell death (PCD) is one possible mechanism that myeloid cells may use to prevent excessive inflammation. Myeloid cell subsets play roles in tissue repair, immune response resolution, and maintenance of homeostasis, so excessive PCD may also influence host resilience in this way. In addition, myeloid cell death is one mechanism used to control pathogen replication and dissemination. Many of these functions for PCD have been well defined in vitro, but the role in vivo is less well understood. We created a mouse that constitutively expresses the pro-survival B-cell lymphoma (bcl)-2 protein in myeloid cells (CD68(bcl2tg), thus decreasing PCD specifically in myeloid cells. Using this mouse model we explored the impact that decreased cell death of these cells has on infection with two different bacterial pathogens, Legionella pneumophila and Streptococcus pyogenes. Both of these pathogens target multiple cell death pathways in myeloid cells, and the expression of bcl2 resulted in decreased PCD after infection. We examined both pathogen clearance and host resilience and found that myeloid cell death was crucial for host resilience. Surprisingly, the decreased myeloid PCD had minimal impact on pathogen clearance. These data indicate that the most important role of PCD during infection with these bacteria is to minimize inflammation and increase host resilience, not to aid in the clearance or prevent the spread of the pathogen.

Microdialysis Assessment of Cerebral Perfusion during Cardiac Arrest, Extracorporeal Life Support and Cardiopulmonary Resuscitation in Rats - A Pilot Trial.

Cerebral metabolic alterations during cardiac arrest, cardiopulmonary resuscitation (CPR) and extracorporeal cardiopulmonary life support (ECLS) are poorly explored. Markers are needed for a more personalized resuscitation and post—resuscitation care. Aim of this study was to investigate early metabolic changes in the hippocampal CA1 region during ventricular fibrillation cardiac arrest (VF-CA) and ECLS versus conventional CPR. Male Sprague-Dawley rats (350g) underwent 8min untreated VF-CA followed by ECLS (n = 8; bloodflow 100ml/kg), mechanical CPR (n = 18; 200/min) until return of spontaneous circulation (ROSC). Shams (n = 2) were included. Glucose, glutamate and lactate/pyruvate ratio were compared between treatment groups and animals with and without ROSC. Ten animals (39%) achieved ROSC (ECLS 5/8 vs. CPR 5/18; OR 4,3;CI:0.7–25;p = 0.189). During VF-CA central nervous glucose decreased (0.32±0.1mmol/l to 0.04±0.01mmol/l; p<0.001) and showed a significant rise (0.53±0.1;p<0.001) after resuscitation. Lactate/pyruvate (L/P) ratio showed a 5fold increase (31 to 164; p<0.001; maximum 8min post ROSC). Glutamate showed a 3.5-fold increase to (2.06±1.5 to 7.12±5.1μmol/L; p<0.001) after CA. All parameters normalized after ROSC with no significant differences between ECLS and CPR. Metabolic changes during ischemia and resuscitation can be displayed by cerebral microdialysis in our VF-CA CPR and ECLS rat model. We found similar microdialysate concentrations and patterns of normalization in both resuscitation methods used. Institutional Protocol Number: GZ0064.11/3b/2011