Abstract
Monitoring of small ruminants for transmissible spongiform encephalopathies (TSEs) has recently become more relevant after two natural scrapie suspected cases of goats were found to be positive for classical BSE (C-BSE). C-BSE probably established itself in this species unrecognized, undermining disease control measures. This opens the possibility that TSEs in goats may remain an animal source for human prion diseases. Currently, there are no data regarding the natural presence of the atypical BSE in caprines. Here we report that C-BSE and L-type atypical BSE (L-BSE) isolates from bovine species are intracerebrally transmissible to goats, with a 100% attack rate and a significantly shorter incubation period and survival time after C-BSE than after L-BSE experimental infection, suggesting a lower species barrier for classical agentin goat. All animals showed nearly the same clinical features of disease characterized by skin lesions, including broken hair and alopecia, and abnormal mental status. Histology and immunohistochemistry showed several differences between C-BSE and L-BSE infection, allowing discrimination between the two different strains. The lymphoreticular involvement we observed in the C-BSE positive goats argues in favour of a peripheral distribution of PrPSc similar to classical scrapie. Western blot and other currently approved screening tests detected both strains in the goats and were able to classify negative control animals. These data demonstrate that active surveillance of small ruminants, as applied to fallen stock and/or healthy slaughter populations in European countries, is able to correctly identify and classify classical and L-BSE and ultimately protect public health.
Highlights
Many mammalian species can be affected by prion diseases or transmissible spongiform encephalopathies (TSEs), fatal neurodegenerative diseases caused by the conformational conversion of the normal, host-encoded cellular prion protein (PrPC) into a pathological
The present study provides the first evidence of successful transmission of L-type atypical bovine spongiform encephalopathy (BSE) (L-BSE) to goats via the intracerebral route, allowing its comparison with classical BSE (C-BSE) infection in goats
The disease phenotypes observed in the C-BSE and L-BSE infected goats showed similar clinical manifestations: early clinical signs were skin lesions mainly on the neck, shoulders, sacral region, hind limbs, and tail, probably resulting from scratching against the walls of the shed or under the trough
Summary
Many mammalian species can be affected by prion diseases or transmissible spongiform encephalopathies (TSEs), fatal neurodegenerative diseases caused by the conformational conversion of the normal, host-encoded cellular prion protein (PrPC) into a pathological. Classical and L-BSE transmits to goats protease-resistant isoform, termed pathological prion protein (PrPSc). TSEs include bovine spongiform encephalopathy (BSE) in cattle, scrapie in sheep and goats, chronic wasting disease (CWD) in cervids, transmissible mink encephalopathy (TME) in mink and Kuru, and Creutzfeldt-Jakob disease (CJD) in humans. Since 2004, two atypical strains of BSEs have been distinguished from the classical type, based on a higher or lower apparent molecular mass profile of the unglycosylated PrPSc band: H-BSE and L-BSE, respectively, or bovine amyloidotic spongiform encephalopathy (BASE) [2,3]. Given the epidemiological characteristics of these forms, it has been speculated that the atypical strains are genetic in origin and/or arise spontaneously
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
