Term
|
Definition
+sense RNA
5'cap,leader squence and poly A tail
Thereofre once released into cytoplasm = ready to be translated |
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Term
|
Definition
+sense RNA
5'cap,leader squence and poly A tail
Thereofre once released into cytoplasm = ready to be translated |
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|
Term
| nucelocapsid of coronavirus = |
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Definition
|
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Term
|
Definition
| yes! lipid ENV, host derived |
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Term
| peplomers of caorona virus = |
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Definition
| large club shaped peplomers (made up of glycoproteins) = spike proteins |
|
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Term
| whats special about corona virus? |
|
Definition
|
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Term
|
Definition
| many ORFs that cant all be translated directly from genome |
|
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Term
| initially what ORFs are translated? |
|
Definition
| the 2 ORFs closest to the leader sequence |
|
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Term
|
Definition
| ...gut cells, monocytes and neutrophils |
|
|
Term
| entry of corona into host cell -= |
|
Definition
attach to cell via aminopeptidase N on host cell mb = endocytosis.
Then fusion of virus with vesicle = release RNA into cytoplasm |
|
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Term
|
Definition
| ...one of two alternative start codons at ORF 1 or ORF 2 |
|
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Term
|
Definition
| ...polyproteins that are cleaved by viral proteolytic enzymes and assembled into large RNA pol complex |
|
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Term
|
Definition
| ...-ive RNA - use this as a template from which to make new + copies of the entire virus genome |
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|
Term
| HOw does the virus translate the rest of the ORFs? |
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Definition
| the viral RNA pol makes a series of nested +ive mRNAs in which the remaining sequences/ORFs are placed next to the leader sequence |
|
|
Term
| how are nested + mRNAs made? |
|
Definition
| by copying -ve RNA template from polyU end then dissociating from it = miss out a section and re-associating to complete transcript = leader seq next to ORF that was originally further down the RNA strand |
|
|
Term
| how many proteins do nested + mRNAs code for? |
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Definition
|
|
Term
| advantages of nested + mRNAs/nested transcripts = |
|
Definition
more economical
(can make more of proteins you want without making more of everything else) |
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|
Term
| nucleoprotein of corona (RNA and capsid synth in... |
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Definition
|
|
Term
| spike proteins and peplomers are synth in... |
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Definition
|
|
Term
| corona virus gets ENV from... |
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Definition
|
|
Term
| corona is packaged in .... |
|
Definition
| ...golgi body and then released by exocytosis |
|
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Term
| advantage of IC budding = |
|
Definition
| dont expose peplomers to hosts immunity as soon/b4 exocytosis = delay immune response (gd way to evade immune resposne a bit longer, doesnt cause host cell death by immune response so can live and replicate in host cell for longer) |
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|
Term
| examples of corna viruses = |
|
Definition
porcine transmissable gastroenteritis (PTGE)
porcine epidemic diarrhoea (PED)
Porine haemagglutinating encephalomyelitis
resp variant of TGE
Bovine coronavirus
canine cornovirus
FCoV & FIP |
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Term
| Porcine transmissable gastroenteritis infection occurs via... |
|
Definition
| ...ingestion (virus is acid labile but protected by milk or food = allows passage through stomach - resistant to proteolytic enzymes) |
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Term
| Porcine transmissable gastroenteritis infects... |
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Definition
| ... intestinal villi in SI (NOT crypts)and macro |
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|
Term
| hours after Porcine transmissable gastroenteritis virus infection... |
|
Definition
| ...the entire SI can be infected!! (rapidly cytotoxic) |
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|
Term
| main result of Porcine transmissable gastroenteritis virus infection = |
|
Definition
|
|
Term
| what happens if neonates get Porcine transmissable gastroenteritis? |
|
Definition
neonates/piglets express lactase, that breaks down milk,on their enterocytes, destroy enterocytes = milk not broken down = lactose goes to colon = XS lactose in colon = nutrient for enterobacteriacaea such as E. coli =incr in e . coli = inflam and lactose fermentation by bacteria incr osmolarity = enhances diarrhoea
Give neonates Abs to stop bacteria fermenting lactose in colon adding to the problem. |
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|
Term
| if got Porcine transmissable gastroenteritis may die of |
|
Definition
|
|
Term
| if got Porcine transmissable gastroenteritis and dont die of dehydration... |
|
Definition
| ...recovery is rapid as crypt cells continue to divide and replaced damaged epi. |
|
|
Term
| coronavirus syndromes recognised in pigs = |
|
Definition
1. TGE
2. porcine epidemic diarrhoea
3. porcine haemagglutinating encephalomyelitis |
|
|
Term
| intro of TGE into a niave herd = |
|
Definition
vom
diarrhoea
fever
throughout herd |
|
|
Term
| morbidity of Porcine transmissable gastroenteritis = |
|
Definition
| 100% (all pigs in niave herd will be infected) |
|
|
Term
| mortality of Porcine transmissable gastroenteritis = |
|
Definition
near 100% :(
neonates are v susceptible |
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|
Term
| adults infected with Porcine transmissable gastroenteritis = |
|
Definition
| may recover but may become persistantly infected = carriers |
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|
Term
| ow long is virus secreted for in carriers of Porcine transmissable gastroenteritis ? |
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Definition
|
|
Term
| most common animals see infected with Porcine transmissable gastroenteritis = |
|
Definition
| weaned piglets (espec if weaned v young) = post weaning diarrhoea as removed maternal IgA from milk |
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|
Term
| how is IGA protective against Porcine transmissable gastroenteritis |
|
Definition
| binds to virus and inactivates virus attachment |
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|
Term
| IgG in Porcine transmissable gastroenteritis = |
|
Definition
| neutralise virus in vitro but NO protection in vivo |
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|
Term
| dx of Porcine transmissable gastroenteritis |
|
Definition
immunofluorescence of intestinal tissue at PM
serology |
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|
Term
| vacc for Porcine transmissable gastroenteritis ? |
|
Definition
no effective vacc :(
nevertheless vacc sow with live attenuated TGE virus to boost maternal immunity |
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Term
| some herds ben able to eradicate Porcine transmissable gastroenteritis by... |
|
Definition
| ...strict hygeine and removal of sero+ adults |
|
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Term
| does Porcine transmissable gastroenteritis virus surive well outside host? |
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Definition
| NO! must be carrier - adult with highest Ig levels = carrier and is culled to try and eliminat virus from herd |
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|
Term
| prevelance of Porcine transmissable gastroenteritis |
|
Definition
|
|
Term
| preventioin by of Porcine transmissable gastroenteritis by... |
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Definition
|
|
Term
| what is very similar to Porcine transmissable gastroenteritis but less severe (lowere mortalitiy rates) |
|
Definition
| porcine epidemic diarrhoea corona virus |
|
|
Term
| if niave herd infected with porcine epidemic diarrhoea (PED) = |
|
Definition
|
|
Term
| whats more common TGE or PED? |
|
Definition
|
|
Term
| infection with PED in sows and weaners = |
|
Definition
| transient vom and diarrhoea |
|
|
Term
| how do you dx between TGE and PED? |
|
Definition
| lab testing - ELISA test on faeces |
|
|
Term
| porcine haemogglutinating encephalitis = |
|
Definition
|
|
Term
| infection of porcine haemagglutinating encephalomyeltitis infects pigs via.... |
|
Definition
...the nasal mucosa and spreads to lungs and SI
Also invades nervous system via vagus and trigeminal nerves |
|
|
Term
| what coronavirus syndrome in pigs DOES NOT cause diarrhoea? |
|
Definition
| porcince haemagglutination encephalomyelitis |
|
|
Term
| porcine haemagglutination encephalomyelitis causes... |
|
Definition
...protaracted vom (lasts a long time)
& subsequential weight loss
this is due to infection of distal ganglion of vagus and the vom centre |
|
|
Term
| neurosymptoms or porcine haemagglutinating encephalomyelitis = |
|
Definition
hyperasethesia
paralysis
mm tremors |
|
|
Term
| porcine haemagglutinating encephalomyelitis is very similar to .... (and how are these two differentiated?) |
|
Definition
... porcine polioencephalomyelitis (caused by enterovirus infection)
differentiate between these two via virus isolation and haemagglutination of porcine haemagglutinating enchephalomyelitis virus |
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|
Term
|
Definition
| serologically the same as TGE but has deletion mutant = lost enterotropism and gained tropism for resp tract |
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Term
|
Definition
| transient cough for 1-2days |
|
|
Term
| resp TGE spreads rapidly through herd via... |
|
Definition
...aerosol (can spread for miles!)
- more rapid than TGE |
|
|
Term
| advantage for pigs becoming infected with resp variant of TGE = |
|
Definition
on recovery seroconvert to TGE = immunity against TGE = by fortunate chance virus has mutated and has self vaccinating :)
because of this TGE has become rare in UK and mainland EU |
|
|
Term
| bovine coronavirus is like... |
|
Definition
|
|
Term
| bovine coronavirus is a major cause of... |
|
Definition
...diarrhoea in calves/yellow scour
(like TGE in piglets) |
|
|
Term
| bovine coronavirus causes what in adult cattles? |
|
Definition
water dysentery/black scours - every cow in herd gets transient diarrhoea for a day or 2
profuse watery dark diarrhoea (may contain blood) |
|
|
Term
| where is bovine corona virus found in the world? |
|
Definition
|
|
Term
| dx of bovine coronavirus = |
|
Definition
ELISA of faeces
immunofluorescenceof SI |
|
|
Term
| host response to spike protien of bovine coronavirus = |
|
Definition
|
|
Term
| bovine corona virus infects... |
|
Definition
...mainly villi = diarrhoea
can infect resp cells and LNs = resp signs |
|
|
Term
| canine coronavirus causes... |
|
Definition
| ...mild enteritis in puppies (espec post weaned pups) |
|
|
Term
| most strains of canine corona virus = |
|
Definition
|
|
Term
| no epidemic of corona virus in dogs, why? |
|
Definition
| probs cus got loadsa low pathogenic strains = act as cover/vacc |
|
|
Term
| 2 distinct forms of canine coronavirus = |
|
Definition
|
|
Term
| outbreak of resp form of canine coronavirus = |
|
Definition
|
|
Term
| what incr risk of infection of canine coronavirus? |
|
Definition
|
|
Term
| enteric canine coronavirus can persist in gut for... |
|
Definition
| ...months with periodic shedding in faeces with no clinical signs! |
|
|
Term
|
Definition
| ubiquitous avirulent virus |
|
|
Term
consequences of FCoV in
a) adult cats
b) kittens |
|
Definition
a) assymptomatic = carrier cats - intermitantly shed virus (can get diarrhoea/be symptomatic)
b) diarrhoea |
|
|
Term
|
Definition
|
|
Term
| risk with perisitant carrier state of FCoV = |
|
Definition
|
|
Term
|
Definition
receptor used by virus = inknown
most prevelant/common
hard to grow in vitro = hard to study |
|
|
Term
|
Definition
v. similar to canine coronavirus, TGE and bovine coronavirus
Receptor = aminopeptidase N
grows well - can grow in vitro
less common |
|
|
Term
| FIP can evolve from persistant infection with which serotype? |
|
Definition
|
|
Term
| evolution of FCoV to FIP = |
|
Definition
| changes in cell tropism - macrophage tropism |
|
|
Term
|
Definition
| ...macro golgo body = not exposed on cell surface = IC budding = delay immune response and host cell death |
|
|
Term
| why doesnt infected macro with FIP apoptose? |
|
Definition
| FIP interferes with normal cell processes and protects macro from ADCC and NK cells |
|
|
Term
| Immunopathology/cyclical pathology of FIP = |
|
Definition
-infection of macro = incr inflam cytokines by macro = incr bv perm = fluid builds up in peritoneum
-immune response = Thelper cells, antiviral cytotoxic Tcells, neutro and perivascular necrosis
-chemotaxis of macro = incr virus infection of macro
-pyogranulomatous foci containing neutro, lympho, macro, depo of IGG-virusC'3 complexes (activated C' punches cellmbs, even endothelial cells = leaky bvs) |
|
|
Term
| Genetic sequencing of FIP and FCoV |
|
Definition
| not found any consistant differences between FIP and FCoV |
|
|
Term
|
Definition
|
|
Term
|
Definition
-vary depending on organs affected
-malaise sickness (due to incr inflam mediators)
-peritonitis, plurisy (inflam of pleura = pain when breathe)
-uvietis (inflam of eye)
-CNS infection and lesions
-vasculitis and oedema |
|
|
Term
| first sign of FIP often = |
|
Definition
|
|
Term
|
Definition
| PM lesions (granulomatous foci=fibrin, leaky bvs, damage coating intestine and peritoneal lesions) |
|
|
Term
| IgGs and Tcells role in FIP = |
|
Definition
| tends to make things worse by enhancing macro infection = accelerated pathogenesis |
|
|
Term
| cytotoxic Tcells role in FIP |
|
Definition
may be imp in controlling initial virus infection by removing infected cell b4 persistant stage (viral peptides may be expressed by MHC in the beginning)
Dont yet know what proteins the cytotoxic Tcell would target |
|
|
Term
|
Definition
|
|
Term
| admin temp attenuated vacc for FCoV = |
|
Definition
intranasal
need to give annual boosters |
|
|
Term
| in FIP is immunity helpful? |
|
Definition
| no ! tends to make things worse! |
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|
