Lecture 21: TSE Flashcards
T or f: chronic wasting disease is reportable
true
how do you dx chronic wasting disease
postmortem ELISA, IHC of brainstem (obex) and retropharyngeal LN
what would a positive IHC staining for CWD look like
spongiform degeneration in obex (brainstem) with CWD + staining in RLN +/- obex
what is the difference between normal prion and infectious prion
protein misfolding
Normal prion: PrPc
Infectious prion: PrPres
Infectious prions are very resistant to __ and __
disinfection and sterilization
long incubation periods for prion disease but still ultimately___
fatal
t or f: prion diseases have no specific immune response
true
t or f: prion disease is zoonotic
true
what is the cellular prion protein all vertebrates have
PrPc
cellular prion protein is a ___anchored extracellular monomer
membrane anchored
what is cellular prion protein degraded by
ubiquitin-proteasome system
infectious prion protein sequence is identical to cellular protein but differences in __
tertiary structure (beta sheets form)
infectious prion proteins are extremely resistant to __
harsh physical treatments
infectious prion proteins form __ that obstruct __
fibrillar amyloid that obstruct UPS
What diseases in humans are prion diseases similar too
Alzheimer’s and Parkinson’s
how is scrapie and CWD spread
biological fluids, environmental contamination
True or false scrapie and CWD is zoonotic
false
how do cows get BSE
meat and bone meal- consumption of infected tissues
T or f: BSE is zoonotic
true
what Are dead end hosts for BSE
humans and cattle
what pathogenesis for TSE
- Oral exposure
- Centripetal propagation (Periphery to CNS or lymphatics)
- Centrifugal dissemination (muscle, oral and renal tissues, antler, caudal GI tract, nasal epithelium)
what TSE’s travel on PNS to. CNS
CWD, scrapie, BSE, CJD
what TSE’s can travel on lymphatics to CNS
CWD and scrapie
Which TSE’s do centrifugal dissemenation
CWD and scrapie
what is incubation period and susceptibility for prion disease dependent on
agent, host (genotype), route of inoculation, dose
How does the host genotype alter susceptibility to prion disease
subtle alterations in host prion compared to infectious PrP can make it so can’t infect or incubation period much longer
what is the host genotype in sheep for prion disease that is resistant
ARR
in white tailed deer, mule deer, and elk various __affect susceptibility from prion disease, but not are 100% protective
various polymorphisms
what is species barrier and how does that relate to prion disease resistance
Not all species have exact same prion and therefore not able to be infected by all infectious prion diseases
what species are affected by CWD and who is not
cervids, lab animals, not humans
What species is affected by BSE
cattle, several domestic and wild species, as well as humans
what are TSE clinical signs
downer cattle, incoordination, persistent scratching, hypersalivation, PU/PD
What samples do you collect for TSE dx: BSE and CWD
BSE: obex
CWD: RLN and obex
how do you dx TSE and what are you looking for
IHC: gold standard
ELISA
Spongiform degeneration
what is control for scrapie
depopulation
Selective breeding (ARQ/ARR)
what is control of CWD
depopulation
what is control for BSE
MBM (meat, bone meal) bans, depopulation
what is pathogenesis for BSE
PNS—> CNS
how is CWD transmitted
Horizontal (excrete/environment)
how is BSE transmitted
iatrogenic (MBM)
