Neuropathological survey of fallen stock: Active surveillance reveals high prevalence of encephalitic listeriosis in small ruminants
ABSTRACT This paper describes the prevalence of brain lesions in the Swiss fallen stock population of small ruminants. 3075 whole brains (75% sheep, 25% goats) were collected as part of a year-long active survey of transmissible spongiform encephalopathies (TSEs) in small ruminants conducted by the Swiss authorities between July 2004 and July 2005. All fallen stock brains were systematically examined by histopathology to obtain reliable data on histologically identifiable brain lesions. Lesions were found in an unexpectedly high number of animals (8.1% of all examined brains). A wide spectrum of diseases was detected showing that this approach provides an excellent opportunity to screen for the prevalence of neurological diseases. Encephalitic listeriosis was by far the most frequent cause of CNS lesions in both species and its prevalence was unexpectedly high when compared to notified confirmed cases. In conclusion, the prevalence of listeriosis as estimated by passive surveillance based on the notification of clinical suspects has been underestimated in the past.
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ABSTRACT: AimsListeriosis is a frequent silage-associated disease in ruminants. The slugs Arion vulgaris are invaders in gardens, vegetable crops and meadows for silage production. Field and laboratory studies were conducted to clarify whether slugs could host Listeria monocytogenes and thereby constitute a threat to animal feed safety.Methods and ResultsSelective culture of L. monocytogenes from 79 pooled slug samples (710 slugs) resulted in 43% positive, 16% with mean L. monocytogenes values of 405 CFU g−1 slug tissues. Of 62 individual slugs cultured, 11% also tested positive from surface/mucus. Multilocus sequence typing analysis of 36 isolates from different slug pools identified 20 sequence types belonging to L. monocytogenes lineages I and II. Slugs fed ≅4·0 × 105 CFUL. monocytogenes, excreted viable L. monocytogenes in faeces for up to 22 days. Excretion of L. monocytogenes decreased with time, although there were indications of a short enrichment period during the first 24 h.Conclusions Arion vulgaris may act as a vector for L. monocytogenes.Significance and Impact of the StudyHighly slug-contaminated grass silage may pose a potential threat to animal feed safety.Journal of Applied Microbiology 01/2015; 118(4). DOI:10.1111/jam.12750 · 2.39 Impact Factor
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ABSTRACT: Primary neoplasms of the central nervous system have been rarely reported in sheep. A three-year-old Rasa Aragonesa ewe was admitted to the small ruminant external consultancy at the Veterinary Faculty of University of Zaragoza, Spain. Clinical, haematological and neurological examinations were performed. Neurological examination showed signs of ataxia, hyperextension of the right front limb and abnormal postural reactions. The animal was unable to stand and walk, even with help. Patellar and flexor reflexes were normal and superficial sensation was present but decreased. Humanitarian sacrifice was carried out one month later. Gross and histopathological findings revealed a choroid plexus papilloma located in the fourth ventricle of the brain. To the authors' knowledge this is the first description of this neoplastic disorder in sheep.Acta Veterinaria Brno 01/2013; 82(1-1):9-11. DOI:10.2754/avb201382010009 · 0.45 Impact Factor
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ABSTRACT: Listeriosis is an emerging zoonotic infection of humans and ruminants worldwide caused by Listeria monocytogenes (LM). In both host species, CNS disease accounts for the high mortality associated with listeriosis and includes rhombencephalitis, whose neuropathology is strikingly similar in humans and ruminants. This review discusses the current knowledge about listeric encephalitis, and involved host and bacterial factors. There is an urgent need to study the molecular mechanisms of neuropathogenesis, which are poorly understood. Such studies will provide a basis for the development of new therapeutic strategies that aim to prevent LM from invading the brain and spread within the CNS.Interdisciplinary Perspectives on Infectious Diseases 02/2010; 2010(1687-708X):632513. DOI:10.1155/2010/632513