#19 bats as a form of Zoonoses Flashcards
what family is Hendra and Nipah virus
Paramyxoviridae
-ssRNA
what is unique about Hendra and Nipah virus?
the genome is very large
much larger than other paramyxoviridae
they have much larger non-coding regions
where did Hendra and Nipah originate?
bats?
how did the first hendra outbreak transmit?
from bats > horse > human
there was no human to human transmission
how did the first outbreak of Nipah occur?
what about the second?
bats > pigs > humans
second outbreak was bat directly to human, then human to human transmission
what is the reservoir of nipah?
bats
what family is SARS?
-coronaviridae
+ssRNA
what is unique about SARS?
it has a large genome -over 30kB
did SARS come back?
yes - in the form of MERS
what family is MERS?
coronaviridae
does SARS need a intermediate host?
yes -
what is SADS
a relative of SARS
hasnt come to humans yet but may
is killing pigs at the moment
what family is the Malaka virus
reovirus
dsRNA
genus orthoreovirus
how is Malaka virus transmitted
- bat to human
then human to human
(dad was infected by bat and then gave to children)
gives severe pneumonia
what is the resevoir of Malaka virus
bats
is Malaka virus fusogenic or non-fusogenic
non-fusogenic
what family is ebolavirus
filoviridae
-ssRNA
can ebola be isolated ?
not yet
there is no vaccine
what is the death rate of ebola?
40%
why is it believed bats are the reservoir for Ebola?
there is a related virus in bats called Mengla virus
can you produce clinical signs from virus infection in bats
it is difficult to show signs of virus in bats however you can isolate virus from them
is there higher viral prevelence in bats?
yes bats can carry more species of virus
is there higher genetic diversity of virus in bats?
yes
what makes bats special?
bats have enhanced DNA damage repair
bats have reduced inflammation
they have elevated innate defence
they have dampened innate responses and increased tolerance of viruses
what is different between bats and humans?
our inflammation response is different
how is inflammation different in humans and bats
human base line level of inflammation is low
bat baseline inflammation is higher
when a virus enters humans will have a high increase of inflammatory molecules. IFNa will not be expressed until danger is sensed
in bats they have a high level of IFNa, when there is a virus they do not need to increase inflammatory molecules
how does a high basal level of HSPs help the bat?
- heat shock proteins are produced when a cell is stressed
- in bats these are on without any stress
- HSPs in bats help protein folding - they cause a hyper-folding environment - allows viruses to tolerate mutations
hence bats can harbour increased diversity of viruses
HSPs help protein folding
what is a hyper-folding environment
caused by high levels of HSPs
when there are HSPs this creates a hyper-folding environment where viruses can tolerate mutations better
what is a hypo-folding environment
less HSPs in cell
when there are less HSPs this creates a hypo-folding environment where viruses cannot tolerate mutations well
how do bats have dampened immune activation?
- they have dampened STING pathway
-STING is not as active in bats as it is in human cells - dampened response to cytosolic dsDNA
bat also dont have 2 sensors AIM2 and IFI16
how do bats dampen inflammation?
they dampen every step of the inflammasome pathway
how do bats tolerate MERS?
- in human cells MERS will stimulate inflammasome activation
in bats there is NO inflammation from MERS hence it can tolerate the virus
what causes efficient DNA repair in bats?
high oxidative stress from flying
do bats have less cancer and live longer?
yes
