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TSEs in humans include kuru , fatal familial insomnia , Gerstmann-Straussler-Scheinker disease , and Creutzfeldt-Jakob disease (see [link] ). TSEs in animals include mad cow disease , scrapie (in sheep and goats), and chronic wasting disease (in elk and deer). TSEs can be transmitted between animals and from animals to humans by eating contaminated meat or animal feed. Transmission between humans can occur through heredity (as is often the case with GSS and CJD) or by contact with contaminated tissue, as might occur during a blood transfusion or organ transplant. There is no evidence for transmission via casual contact with an infected person. [link] lists TSEs that affect humans and their modes of transmission.

Transmissible Spongiform Encephalopathies (TSEs) in Humans
Disease Mechanism(s) of Transmission National Institute of Neurological Disorders and Stroke. “Creutzfeldt-Jakob Disease Fact Sheet.” http://www.ninds.nih.gov/disorders/cjd/detail_cjd.htm (accessed December 31, 2015).
Sporadic CJD (sCJD) Not known; possibly by alteration of normal prior protein (PrP) to rogue form due to somatic mutation
Variant CJD (vCJD) Eating contaminated cattle products and by secondary bloodborne transmission
Familial CJD (fCJD) Mutation in germline PrP gene
Iatrogenic CJD (iCJD) Contaminated neurosurgical instruments, corneal graft, gonadotrophic hormone, and, secondarily, by blood transfusion
Kuru Eating infected meat through ritualistic cannibalism
Gerstmann-Straussler-Scheinker disease (GSS) Mutation in germline PrP gene
Fatal familial insomnia (FFI) Mutation in germline PrP gene

Prions are extremely difficult to destroy because they are resistant to heat, chemicals, and radiation. Even standard sterilization procedures do not ensure the destruction of these particles. Currently, there is no treatment or cure for TSE disease, and contaminated meats or infected animals must be handled according to federal guidelines to prevent transmission.

  • Does a prion have a genome?

Resolution

A few days later, David’s doctor receives the results of the immunofluorescence test on his skin sample. The test is negative for rabies antigen. A second viral antigen test on his saliva sample also comes back negative. Despite these results, the doctor decides to continue David’s current course of treatment. Given the positive RT-PCR test, it is best not to rule out a possible rabies infection.

Near the site of the bite, David receives an injection of rabies immunoglobulin, which attaches to and inactivates any rabies virus that may be present in his tissues. Over the next 14 days, he receives a series of four rabies-specific vaccinations in the arm. These vaccines activate David’s immune response and help his body recognize and fight the virus. Thankfully, with treatment, David symptoms improve and he makes a full recovery.

Not all rabies cases have such a fortunate outcome. In fact, rabies is usually fatal once the patient starts to exhibit symptoms, and postbite treatments are mainly palliative (i.e., sedation and pain management).

Go back to the previous Clinical Focus box.

Key concepts and summary

  • Other acellular agents such as viroids , virusoids , and prions also cause diseases. Viroids consist of small, naked ssRNAs that cause diseases in plants. Virusoids are ssRNAs that require other helper viruses to establish an infection. Prions are proteinaceous infectious particles that cause transmissible spongiform encephalopathies .
  • Prions are extremely resistant to chemicals, heat, and radiation.
  • There are no treatments for prion infection.

Fill in the blank

Both viroids and virusoids have a(n) _________ genome, but virusoids require a(n) _________ to reproduce.

RNA, helper virus

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Short answer

Describe the disease symptoms observed in animals infected with prions.

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Questions & Answers

what is the size of virus
Beatrice Reply
What is the difference between TVC and Bioburden test
Mohamed
?
Mohamed
structure of bacteria and 10 types
Jennifer Reply
what is accidental host?
Domingo Reply
what is endomembrane system
Ikpi Reply
what is human anatomy
Ikpi
okay. Go ahead and ask
Blessing Reply
Industrial microbiology mcq
mohamed
Okay. What's your question?
Blessing
life arises from living matter or live organism.
Swami Reply
yes
sildra
I think live matter arises from non living matter
sildra
I dont think so...can u explain with an example
Manya
living maters made by non living matters
sildra
non living matters like stones? rocks?
Manya
eno
sildra
no
sildra
then?
Manya
cells are made by C N O minerals etc
sildra
I mentioned these as non living maters
sildra
that's all
sildra
cells are made up of those things but they originate from living things..
Manya
ok
sildra
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Manya
where are you from
sildra
thanks
sildra
India...u?
Manya
Tamil nadu
sildra
I am from Maharashtra
Manya
what about your studies
sildra
completed bsc.. preparing for msc entrance...wbu?
Manya
same
sildra
are you microbiologist
sildra
yes i am
Manya
good
sildra
what s the scope for micro in ur state?
Manya
did you find your college to higher studies
sildra
have to give an entrance exam for every college here...so lets c
Manya
food industries, medical lab, vaccine industries ,etc
sildra
hoping for pune University...wbu?
Manya
great!
Manya
is that centeral University right
sildra
what is your namr
sildra
hello
Udhaya
Hi
Maruf
Family kindly help me with this question? 1) Shortlist the configurative measurements of the following human anatomical ranges of÷ - Blood ( haemeglobin) in both male and female - Haematocytes in both male and female - Hepatocytes in both male and female - Lymphocyte / T. Lymphocytes in both male
Gifted
My names are Gift Mwale and am a Zambian. Kindly help me with this research which goes like this... 1) Shortlist the configurative measurements of the following human anatomical ranges of ÷ - Blood ( haemeglobin) in both male and female - Hepatocytes in both male and female - Haematocytes in both
Gifted
please what is the full meaning for TCDS
UDEME
from a single cell
Freedom
tcds means transcranial direct current stimulation...in this small electric currents are given to brain( specific parts) to help increase brain performance or to help with depression.. current should be in range 0.5-2.0mA
Manya
what's underlying disease relating unsanitary diet microorganism with the highest rate of epidemology solution and efficacy leading molecules elucidated structural solutions
feven
please can anybody talk about brain tumour and its cure.
BELLO Reply
enlargement of the thyroid gland resulting in over production of hormone.
Kamal Reply
What can u say on Thyroid Cancer?
Abdulkareem
Please, talk about the thyroid cancer.
BELLO
explain the Grave's disease
John Reply
what is cell
Avi Reply
is unit of life
Kamaluddeen
Ok
mohamed
who is an industrial microbiologist
Cynthia Reply
I want to know the biochemical composition of bacteria
Josh Reply
It contains peptidoglcon, DNA nd RNA
Asiya
what are Carrier protein
Ikpi
bacteriophage disadvantage
Momina Reply
disease due to __________ abnormalities are termed primary immunodeficiencies
Tayee Reply
Some primary immunodeficiencies are due to a defect of a single cellular or humoral component of the immune system.
Prince
Examples of primary immunodeficiencies include: chronic granulomatous disease, X-linked agammaglobulinemia, selective IgA deficiency etc
Prince
thank you
Nana
explain microbial mutation
Emerald
what is mutation
Cynthia Reply
alteration in genetic makeup
UDEME

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Source:  OpenStax, Microbiology. OpenStax CNX. Nov 01, 2016 Download for free at http://cnx.org/content/col12087/1.4
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