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Now my mind is wondering if insects could be a source and transmitter of prion diseases. Perhaps the proteins in bugs don’t line up with humans though.

helpfulmandrill 4y ago
Why would this be any more likely than other animals?
- chihuahua 4y ago
  Perhaps because insects are more evolutionally distant from humans, than mammals for example. That doesn't mean that it's true, but this could be why someone migh assume that it's true.
deleted 4y ago
[deleted]
drjasonharrison 4y ago
This might explain how wild deer develop prion diseases. My understanding is that they aren't eating the nervous tissues of other animals but perhaps an insect, parasite, or other lifeform is providing the infection.
- beauzero 4y ago
  Develop...maybe. CWD can stay dormant in soil for a long time (2+ years). https://dwr.virginia.gov/wildlife/diseases/cwd/what-are-prions/ https://dwr.virginia.gov/wildlife/diseases/cwd/what-are-prio...
  - MichaelCollins 4y ago
    Deer getting CWD from the soil wouldn't be unprecedented. Sheep get anthrax that way. Animals that keep their head down eating stuff off the ground are particularly susceptible to soil-borne infections.
- kevin_thibedeau 4y ago
  Deer will eat small animals.
- arkush 4y ago
  Plants can transmit prions. Grass plants bind, retain, uptake and transport infectious prions https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4449294/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4449294/ "Prions bind to plants and bound-PrPSc efficiently sustain prion replication Roots and leaves were washed thoroughly and analyzed for the presence of PrPSc by serial PMCA (Morales et al., 2012). The results show that even highly diluted PrPSc can bind to roots and leaves and sustain PrPC conversion (Fig. 1A). [...] However, both roots and leaves capture PrPSc efficiently, even at very small concentrations, equivalent to those present in biological fluids, such as blood and urine (Chen et al., 2010). Animals can be infected by oral ingestion of prion-contaminated plants After exposure, plants were extensively washed 5 times with water and animals fed with dried material orally. [...] All animals that ingested prion contaminated leaves and roots developed typical prion disease. Although the incubation times were significantly longer in animals ingesting prions attached to leaves and roots as compared with those fed directly with the brain material, the differences were not as high as one could have expected (Fig. 2A)." --- Something developed sporadic prion disease (in humans its called "Sporadic Creutzfeldt-Jakob disease": https://pubmed.ncbi.nlm.nih.gov/29887134/ https://pubmed.ncbi.nlm.nih.gov/29887134/ ), died from it, plants grew on the fertilized land and were eaten by deer, the cycle repeats. CWD-infected deer shred prions in urine, feces, probably saliva too (the aforementioned paper mentions that this is enough for plant-mediated infection), a trait shared with scrapie-infected sheep, hamsters and, i assume, BSE-infected cows. Transmission and Detection of Prions in Feces https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2803675/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2803675/ "Oral exposure to prion-tainted blood, urine, saliva and feces have been suggested as modes of transmission for CWD and scrapie among herbivores susceptible to these diseases. Both CWD and scrapie infection is thought likely to enter the body through gut-associated lymphoid tissues, in Peyer's patches in the alimentary tract. Moreover, the presence of the infectious isoform of the prion protein, designated PrPSc, in Peyer's patches suggests alimentary shedding of CWD and scrapie prions into feces. [...] When noninfected Syrian hamsters were cohabitated with Syrian hamsters orally infected with Sc237 prions, we observed 80–100% infection rates within 14 days after oral challenge." Also, birds can spread prions in their litter: Crows don't digest prions, may transport them to other locations https://www.sciencedaily.com/releases/2012/10/121017181250.htm https://www.sciencedaily.com/releases/2012/10/121017181250.h... "Crows fed on prion-infected brains from mice can transmit these infectious agents in their feces and may play a role in the geographic spread of diseases caused by prions, such as chronic wasting disease or scrapie."
arkush 4y ago
All currently confirmed prion diseases are mammalian: Transmissible spongiform encephalopathy https://en.wikipedia.org/wiki/Transmissible_spongiform_encephalopathy https://en.wikipedia.org/wiki/Transmissible_spongiform_encep... There is possibility that ostriches can have some form spongiform encephalopathy: Spongiform encephalopathy in a red-necked ostrich (Struthio camelus) (1991) https://pubmed.ncbi.nlm.nih.gov/1887441/ https://pubmed.ncbi.nlm.nih.gov/1887441/ Luckily, even most mammalian prions have some troubles jumping between mammal species. For example, sheep scrapie can be transmitted to primates in laboratory, but to date considered non-transmissible to humans in nature (fortunately, as it is insidious and regulations on sheep and goats slaughter are laxer than on bovine): Transmission of scrapie prions to primate after an extended silent incubation period https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4485159/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4485159/ "However, one cynomolgus macaque exhibited obvious neurological signs more than 9 years (110 months) after intracerebral exposure to a high dose of a sheep classical scrapie isolate (25 mg of brain)." BSE prions are much more infectious, not only for humans and ruminants, but for other species too, for example, cats and hamsters. --- Personally, I don't expect fish or insects to be sources of infection, only potential (if relatively unlikely) transmitters. That said, apparently nearly everything can be transmitter for prions: * Fish have prion proteins too (currently, no fish prion diseases are known): Fish models in prion biology: underwater issues https://pubmed.ncbi.nlm.nih.gov/20933080/ https://pubmed.ncbi.nlm.nih.gov/20933080/ "To date, the occurrence of TSEs in lower vertebrates like fish and birds has received only limited attention, despite the fact that these animals possess bona fide PrPs." --- * Birds can transmit prions in their poop, spreading them at great distances (keep it in mind when clearing bird feces): Crows don't digest prions, may transport them to other locations https://www.sciencedaily.com/releases/2012/10/121017181250.htm https://www.sciencedaily.com/releases/2012/10/121017181250.h... "Crows fed on prion-infected brains from mice can transmit these infectious agents in their feces and may play a role in the geographic spread of diseases caused by prions, such as chronic wasting disease or scrapie." --- * Insects and parasites can be prion infection vectors: Could ectoparasites act as vectors for prion diseases? https://pubmed.ncbi.nlm.nih.gov/12786866/ https://pubmed.ncbi.nlm.nih.gov/12786866/ "Fly larvae and mites were exposed to brain-infected material and were readily able to transmit scrapie to hamsters. New lines of evidence have confirmed that adult flies are also able to express prion proteins." --- * Plants are acting as prion vectors: Grass plants bind, retain, uptake and transport infectious prions https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4449294/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4449294/ "Prions bind to plants and bound-PrPSc efficiently sustain prion replication [...] These results indicate that leaves and roots can efficiently bind PrPSc, which remains able to catalyze PrPC to PrPSc conversion, leading to prion replication. [...] After exposure, plants were extensively washed 5 times with water and animals fed with dried material orally. [...] All animals that ingested prion contaminated leaves and roots developed typical prion disease. Although the incubation times were significantly longer in animals ingesting prions attached to leaves and roots as compared with those fed directly with the brain material, the differences were not as high as one could have expected (Fig. 2A)." --- * Excrements can transmit prions, thus coprophagous animals, insects included, can too: Transmission and Detection of Prions in Feces https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2803675/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2803675/ "Oral exposure to prion-tainted blood, urine, saliva and feces have been suggested as modes of transmission for CWD and scrapie among herbivores susceptible to these diseases. Both CWD and scrapie infection is thought likely to enter the body through gut-associated lymphoid tissues, in Peyer's patches in the alimentary tract. Moreover, the presence of the infectious isoform of the prion protein, designated PrPSc, in Peyer's patches suggests alimentary shedding of CWD and scrapie prions into feces. [...] When noninfected Syrian hamsters were cohabitated with Syrian hamsters orally infected with Sc237 prions, we observed 80–100% infection rates within 14 days after oral challenge." --- * Even dust can transmit prions: Circulation of prions within dust on a scrapie affected farm https://pubmed.ncbi.nlm.nih.gov/25889731/ https://pubmed.ncbi.nlm.nih.gov/25889731/ "Using protein misfolding cyclic amplification we demonstrate that scrapie PrP(Sc) can be detected within circulating dusts that are present on a farm that is naturally contaminated with sheep scrapie." --- * Even ashes from not sufficiently hot cremation can transmit prions: Infectivity studies of both ash and air emissions from simulated incineration of scrapie-contaminated tissues https://pubmed.ncbi.nlm.nih.gov/15575075/ https://pubmed.ncbi.nlm.nih.gov/15575075/ "We investigated the effectiveness of 15 min exposures to 600 and 1000 degrees C in continuous flow normal and starved-air incineration-like conditions to inactivate samples [...] yielded a total of two transmissions among 21 inoculated animals from the ash of a single specimen burned in normal air at 600 degrees C." I wonder, how bad is prion contamination of the Ganges river in India?

helpfulmandrill 4y ago

Why would this be any more likely than other animals?

chihuahua 4y ago
Perhaps because insects are more evolutionally distant from humans, than mammals for example. That doesn't mean that it's true, but this could be why someone migh assume that it's true.

deleted 4y ago

[deleted]

drjasonharrison 4y ago

This might explain how wild deer develop prion diseases. My understanding is that they aren't eating the nervous tissues of other animals but perhaps an insect, parasite, or other lifeform is providing the infection.

beauzero 4y ago
Develop...maybe. CWD can stay dormant in soil for a long time (2+ years). https://dwr.virginia.gov/wildlife/diseases/cwd/what-are-prions/ https://dwr.virginia.gov/wildlife/diseases/cwd/what-are-prio...
- MichaelCollins 4y ago
  Deer getting CWD from the soil wouldn't be unprecedented. Sheep get anthrax that way. Animals that keep their head down eating stuff off the ground are particularly susceptible to soil-borne infections.
kevin_thibedeau 4y ago
Deer will eat small animals.
arkush 4y ago
Plants can transmit prions. Grass plants bind, retain, uptake and transport infectious prions https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4449294/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4449294/ "Prions bind to plants and bound-PrPSc efficiently sustain prion replication Roots and leaves were washed thoroughly and analyzed for the presence of PrPSc by serial PMCA (Morales et al., 2012). The results show that even highly diluted PrPSc can bind to roots and leaves and sustain PrPC conversion (Fig. 1A). [...] However, both roots and leaves capture PrPSc efficiently, even at very small concentrations, equivalent to those present in biological fluids, such as blood and urine (Chen et al., 2010). Animals can be infected by oral ingestion of prion-contaminated plants After exposure, plants were extensively washed 5 times with water and animals fed with dried material orally. [...] All animals that ingested prion contaminated leaves and roots developed typical prion disease. Although the incubation times were significantly longer in animals ingesting prions attached to leaves and roots as compared with those fed directly with the brain material, the differences were not as high as one could have expected (Fig. 2A)." --- Something developed sporadic prion disease (in humans its called "Sporadic Creutzfeldt-Jakob disease": https://pubmed.ncbi.nlm.nih.gov/29887134/ https://pubmed.ncbi.nlm.nih.gov/29887134/ ), died from it, plants grew on the fertilized land and were eaten by deer, the cycle repeats. CWD-infected deer shred prions in urine, feces, probably saliva too (the aforementioned paper mentions that this is enough for plant-mediated infection), a trait shared with scrapie-infected sheep, hamsters and, i assume, BSE-infected cows. Transmission and Detection of Prions in Feces https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2803675/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2803675/ "Oral exposure to prion-tainted blood, urine, saliva and feces have been suggested as modes of transmission for CWD and scrapie among herbivores susceptible to these diseases. Both CWD and scrapie infection is thought likely to enter the body through gut-associated lymphoid tissues, in Peyer's patches in the alimentary tract. Moreover, the presence of the infectious isoform of the prion protein, designated PrPSc, in Peyer's patches suggests alimentary shedding of CWD and scrapie prions into feces. [...] When noninfected Syrian hamsters were cohabitated with Syrian hamsters orally infected with Sc237 prions, we observed 80–100% infection rates within 14 days after oral challenge." Also, birds can spread prions in their litter: Crows don't digest prions, may transport them to other locations https://www.sciencedaily.com/releases/2012/10/121017181250.htm https://www.sciencedaily.com/releases/2012/10/121017181250.h... "Crows fed on prion-infected brains from mice can transmit these infectious agents in their feces and may play a role in the geographic spread of diseases caused by prions, such as chronic wasting disease or scrapie."

arkush 4y ago

All currently confirmed prion diseases are mammalian: Transmissible spongiform encephalopathy https://en.wikipedia.org/wiki/Transmissible_spongiform_encephalopathy https://en.wikipedia.org/wiki/Transmissible_spongiform_encep... There is possibility that ostriches can have some form spongiform encephalopathy: Spongiform encephalopathy in a red-necked ostrich (Struthio camelus) (1991) https://pubmed.ncbi.nlm.nih.gov/1887441/ https://pubmed.ncbi.nlm.nih.gov/1887441/ Luckily, even most mammalian prions have some troubles jumping between mammal species. For example, sheep scrapie can be transmitted to primates in laboratory, but to date considered non-transmissible to humans in nature (fortunately, as it is insidious and regulations on sheep and goats slaughter are laxer than on bovine): Transmission of scrapie prions to primate after an extended silent incubation period https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4485159/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4485159/ "However, one cynomolgus macaque exhibited obvious neurological signs more than 9 years (110 months) after intracerebral exposure to a high dose of a sheep classical scrapie isolate (25 mg of brain)." BSE prions are much more infectious, not only for humans and ruminants, but for other species too, for example, cats and hamsters. --- Personally, I don't expect fish or insects to be sources of infection, only potential (if relatively unlikely) transmitters. That said, apparently nearly everything can be transmitter for prions: * Fish have prion proteins too (currently, no fish prion diseases are known): Fish models in prion biology: underwater issues https://pubmed.ncbi.nlm.nih.gov/20933080/ https://pubmed.ncbi.nlm.nih.gov/20933080/ "To date, the occurrence of TSEs in lower vertebrates like fish and birds has received only limited attention, despite the fact that these animals possess bona fide PrPs." --- * Birds can transmit prions in their poop, spreading them at great distances (keep it in mind when clearing bird feces): Crows don't digest prions, may transport them to other locations https://www.sciencedaily.com/releases/2012/10/121017181250.htm https://www.sciencedaily.com/releases/2012/10/121017181250.h... "Crows fed on prion-infected brains from mice can transmit these infectious agents in their feces and may play a role in the geographic spread of diseases caused by prions, such as chronic wasting disease or scrapie." --- * Insects and parasites can be prion infection vectors: Could ectoparasites act as vectors for prion diseases? https://pubmed.ncbi.nlm.nih.gov/12786866/ https://pubmed.ncbi.nlm.nih.gov/12786866/ "Fly larvae and mites were exposed to brain-infected material and were readily able to transmit scrapie to hamsters. New lines of evidence have confirmed that adult flies are also able to express prion proteins." --- * Plants are acting as prion vectors: Grass plants bind, retain, uptake and transport infectious prions https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4449294/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4449294/ "Prions bind to plants and bound-PrPSc efficiently sustain prion replication [...] These results indicate that leaves and roots can efficiently bind PrPSc, which remains able to catalyze PrPC to PrPSc conversion, leading to prion replication. [...] After exposure, plants were extensively washed 5 times with water and animals fed with dried material orally. [...] All animals that ingested prion contaminated leaves and roots developed typical prion disease. Although the incubation times were significantly longer in animals ingesting prions attached to leaves and roots as compared with those fed directly with the brain material, the differences were not as high as one could have expected (Fig. 2A)." --- * Excrements can transmit prions, thus coprophagous animals, insects included, can too: Transmission and Detection of Prions in Feces https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2803675/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2803675/ "Oral exposure to prion-tainted blood, urine, saliva and feces have been suggested as modes of transmission for CWD and scrapie among herbivores susceptible to these diseases. Both CWD and scrapie infection is thought likely to enter the body through gut-associated lymphoid tissues, in Peyer's patches in the alimentary tract. Moreover, the presence of the infectious isoform of the prion protein, designated PrPSc, in Peyer's patches suggests alimentary shedding of CWD and scrapie prions into feces. [...] When noninfected Syrian hamsters were cohabitated with Syrian hamsters orally infected with Sc237 prions, we observed 80–100% infection rates within 14 days after oral challenge." --- * Even dust can transmit prions: Circulation of prions within dust on a scrapie affected farm https://pubmed.ncbi.nlm.nih.gov/25889731/ https://pubmed.ncbi.nlm.nih.gov/25889731/ "Using protein misfolding cyclic amplification we demonstrate that scrapie PrP(Sc) can be detected within circulating dusts that are present on a farm that is naturally contaminated with sheep scrapie." --- * Even ashes from not sufficiently hot cremation can transmit prions: Infectivity studies of both ash and air emissions from simulated incineration of scrapie-contaminated tissues https://pubmed.ncbi.nlm.nih.gov/15575075/ https://pubmed.ncbi.nlm.nih.gov/15575075/ "We investigated the effectiveness of 15 min exposures to 600 and 1000 degrees C in continuous flow normal and starved-air incineration-like conditions to inactivate samples [...] yielded a total of two transmissions among 21 inoculated animals from the ash of a single specimen burned in normal air at 600 degrees C." I wonder, how bad is prion contamination of the Ganges river in India?