Transmission of Norwegian reindeer CWD to sheep by intracerebral inoculation results in an unusual phenotype and prion distribution.

Chronic wasting disease (CWD), a prion disease affecting cervids, has been known in North America (NA) since the 1960s and emerged in Norway in 2016. Surveillance and studies have revealed that there are different forms of CWD in Fennoscandia: contagious CWD in Norwegian reindeer and sporadic CWD in moose and red deer. Experimental studies have demonstrated that NA CWD prions can infect various species, but thus far, there have been no reports of natural transmission to non-cervid species. In vitro and laboratory animal studies of the Norwegian CWD strains suggest that these strains are different from the NA strains. In this work, we describe the intracerebral transmission of reindeer CWD to six scrapie-susceptible sheep. Detection methods included immunohistochemistry (IHC), western blot (WB), enzyme-linked immunosorbent assay (ELISA), real-time quaking-induced conversion (RT-QuIC) and protein misfolding cyclic amplification (PMCA). In the brain, grey matter vacuolation was limited, while all sheep exhibited vacuolation of the white matter. IHC and WB conventional detection techniques failed to detect prions; however, positive seeding activity with the RT-QuIC and PMCA amplification techniques was observed in the central nervous system of all but one sheep. Prions were robustly amplified in the lymph nodes of all animals, mainly by RT-QuIC. Additionally, two lymph nodes were positive by WB, and one was positive by ELISA. These findings suggest that sheep can propagate reindeer CWD prions after intracerebral inoculation, resulting in an unusual disease phenotype and prion distribution with a low amount of detectable prions.

Lethal Gram-negative sepsis in healthy pigs during anaesthesia with contaminated propofol.

Two healthy Landrace pigs anaesthetized with propofol suffered rapid onset of fatal sepsis. Clinical signs included severe arterial hypotension, loss of peripheral oxygenation, low end-tidal CO2, clinical onset of pulmonary oedema and cardiac dysfunction. Gross and histopathological examination revealed loss of vascular integrity with severe lung oedema and congestion, haemorrhages in several organs and fluid leakage into body cavities. Large numbers of Gram-negative bacteria, primarily Klebsiella sp., were present in the anaesthetic infusion containing propofol and were also cultured from internal organs of both pigs. The propofol was likely contaminated by bacteria after inappropriate handling and storage in the operating room. This report illustrates the potential for severe nosocomial infection when applying propofol in animals and humans and may serve as a reminder of the importance of strict aseptic practice in general, and specifically in the handling of this anaesthetic agent.