Transmissible Spongiform Encephalopathies (TSEs) or prion diseases are a fatal group of infectious, inherited and spontaneous neurodegenerative diseases affecting human and animals. They are caused by the conversion of cellular prion protein (PrP^C) into a misfolded pathological isoform (PrP^Sc or prion- proteinaceous infectious particle) that self-propagates by conformational conversion of PrP^C. Yet by an unknown mechanism, PrP^C can fold into different PrP^Sc conformers that may result in different prion strains that display specific disease phenotype (incubation time, clinical signs and lesion profile). Although the pathways for neurodegeneration as well as the involvement of brain inflammation in these diseases are not well understood, the spongiform changes, neuronal loss, gliosis and accumulation of PrP^Sc are the characteristic neuropathological lesions. Scrapie affecting small ruminants was the first identified TSE and has been considered the archetype of prion diseases, though atypical and new animal prion diseases continue to emerge highlighting the importance to investigate the lesion profile in naturally affected animals. In this report, we review the neuropathology and the neuroinflammation of animal prion diseases in natural hosts from scrapie, going through the zoonotic bovine spongiform encephalopathy (BSE), the chronic wasting disease (CWD) to the newly identified camel prion disease (CPD).

A survey to determine the occurrence of Mycobacterium avium subsp. paratuberculosis (MAP) in wild carnivores in Portugal was conducted by testing samples from road-killed animals between 2009 and 2012. Postmortem examinations were performed and tissues were collected from wild carnivores representing four families and six different species, with a total of 74 animals analyzed. Cultures were performed by using Löwenstein-Jensen and Middlebrook 7H11 solid media and acid-fast isolates were identified by polymerase chain reaction (PCR) and mycobactin dependency characteristics. Tissues were also screened for MAP by directly extracting DNA and testing for the MAP-specific sequences. The occurrence of infected animals (an animal had at least one tissue that was positive for culture or direct PCR) was 27.0% (n = 20). MAP was isolated from culture of 25 tissue samples (3.8%) and was detected by direct PCR in 40 (6.0%) samples. Infection was recorded in 5/6 studied species: 7/49 (14.3%) red foxes (Vulpes vulpes), 3/3 (100%) beech martens (Martes foina), 2/4 (50.0%) Eurasian otters (Lutra lutra), 7/15 (46.7%) Egyptian mongooses (Herpestes ichneumon), and 1/1 (100%) European badger (Meles meles). These species represent three different taxonomic families: Canidae (14.3% were positive), Mustelidae (75.0% were positive), and Herpestidae (46.7% were positive). The results of this study confirm the presence of MAP infection in wild carnivores in Portugal.