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Oevermann A.,University of Bern | Di Palma S.,Institute of Animal Pathology | Doherr M.G.,University of Bern | Abril C.,Institute of Veterinary Bacteriology | And 2 more authors.
Brain Pathology | Year: 2010

Listeriosis is a serious food-borne disease with increasing frequency in humans and ruminants. Despite the facts that in both hosts, listeriosis can occur as rhombencephalitis and ruminants are a reservoir of Listeria monocytogenes (LM) strains pathogenic for humans, little work has been done on the pathogenesis in ruminants. This study investigates the neuropathogenesis of listeric encephalitis in over 200 natural cases in cattle, sheep and goats by analyzing anatomical distribution, severity, bacterial load and temporal evolution of the lesions. Our results suggest that LM gains access to the brainstem of all three species via axonal migration not only along the trigeminal nerve, but also along other nerves. The ensuing encephalitis does not remain restricted to the brainstem. Rather, LM spreads further from the brainstem into rostral brain regions likely by intracerebral axonal migration. Significant differences in severity of the lesions and bacterial load were found between cattle and small ruminants, which may be caused by species-specific properties of antibacterial immune responses. As histopathological lesions of human rhombencephalitis caused by LM strongly resemble those of ruminants, the disease likely has a similar pathogenesis in both hosts. © 2009 International Society of Neuropathology.

Berset-Istratescu C.M.,Vetsuisse Faculty | Glardon O.J.,Vetsuisse Faculty | Magouras I.,University of Bern | Frey C.F.,Institute of Parasitology | And 2 more authors.
Veterinary Journal | Year: 2014

This study aimed to examine the aetiology of acute diarrhoea and the relapse rate in 100 client-owned dogs presented to a first-opinion clinic. History, physical examination, faecal testing and owner questionnaire data were collected at initial presentation (T0) and at either the time of relapse or at a recheck performed within 3months. All dogs received treatment according to their clinical signs. Of 96 dogs that completed the study, 37 (38.5%) relapsed during the study period, 21 (21.9%) relapsed within 3months, and 16 others (16.6%) at 3months to 1year after initial examination. Dogs that had undergone a change in housing location within 1month prior to presentation and dogs <1year old were significantly more likely to have positive parasitological analyses (P=0.02 and P=0.001, respectively). Pica was a risk factor for relapse (P=0.0002). © 2013 Elsevier Ltd.

Carranza P.,University of Zurich | Grunau A.,University of Zurich | Schneider T.,University of Zurich | Hartmann I.,Institute for Food Safety and Hygiene | And 8 more authors.
Proteomics | Year: 2010

The opportunistic food-borne pathogen Cronobacter sp. causes rare but significant illness in neonates and is capable to grow at a remarkably wide range of temperatures from 5.5 to 47°C. A gel-free quantitative proteomics approach was employed to investigate the molecular basis of the Cronobacter sp. adaptation to heat and cold-stress. To this end the model strain Cronobacter turicensis 3032 was grown at 25, 37, 44, and 47°C, and whole-cell and secreted proteins were iTRAQ-labelled and identified/quantified by 2-D-LC-MALDI-TOF/TOF-MS. While 441C caused only minor changes in C. turicensis growth rate and protein profile, 47°C affected the expression of about 20% of all 891 identified proteins and resulted in a reduced growth rate and rendered the strain non-motile and filamentous. Among the heat-induced proteins were heat shock factors, transcriptional and translational proteins, whereas proteins affecting cellular morphology, proteins involved in motility, central metabolism and energy production were down-regulated. Notably, numerous potential virulence factors were found to be up-regulated at higher temperatures, suggesting an elevated pathogenic potential of Cronobacter sp. under these growth conditions. Significant alterations in the protein expression profile and growth rate of C. turicensis exposed to 25°C indicate that at this temperature the organism is cold-stressed. Up-regulated gene products comprised cold-shock, DNA-binding and ribosomal proteins, factors that support protein folding and proteins opposing cold-induced decrease in membrane fluidity, whereas down-regulated proteins were mainly involved in central metabolism. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA.

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