Term
| calicivirus is commonly associated with ente |
|
Definition
|
|
Term
| replication of calicivirus is broadly similar to... |
|
Definition
|
|
Term
|
Definition
|
|
Term
| capsomers of calicivirus = |
|
Definition
90 dimers of a single protien seen on EM
characteristic cup shaped |
|
|
Term
| genetic makeup of calicivirus = |
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
| dual Rs for sialic acid and JAMA (junction associated molecule A - found at cell junctions, holds cell together) |
|
|
Term
|
Definition
| binding with Rs =viruses changes shape and becomes hydrophobic. The bound virus is transported via clathrin coated pits and endocytosed. H+ ions then pumped into endosome to acidify it and then virus releases DNA into cytoplasm. |
|
|
Term
|
Definition
|
|
Term
| instead of cap FCV had... |
|
Definition
| ...VPG (virus protein genome) |
|
|
Term
| 1st step in translation of +ssRNA of FCV = |
|
Definition
| translate ORF 1 only = codes for polyprotein which is cleaved by protease = NSP 1-6 eg helicase, protease, RNA pol |
|
|
Term
|
Definition
| get two strands apart for replication |
|
|
Term
| enzymes from ORF 1 synthesise... |
|
Definition
| ...intermediate full length -stran RNA from which viral genome can be copied |
|
|
Term
|
Definition
|
|
Term
| ORF 3 is translated into... |
|
Definition
| ...VP2 (small protein that aids capsid assembly, but not part of virus particle) |
|
|
Term
| how many times is ORF 2 translated and why? |
|
Definition
| 180 times as 90 dimers of VP1 are needed to make capsid |
|
|
Term
| hy is it good ORF 2 is translated seperately to ORF 1? |
|
Definition
ORF 2 needs to be translated 180 times to make capsid of 90 dimers of VP1, if ORF 1 had to be translated along with this that would make XS proteases that would destroy the cell.
The way FCV doe sit means you get a more persistant infection without detsroying the host cell
Advantage in terms of economy (energy of virus) and persistance of virus |
|
|
Term
| FCV leaves host cell via... |
|
Definition
|
|
Term
|
Definition
|
|
Term
| get systemic effects/sickness behaviour due to ... |
|
Definition
|
|
Term
|
Definition
accounts for 40% of URT infections
v widespread - most kittens become infected early in life (b4 1yr old, thereofre almost all cats >1yr = seropositive) |
|
|
Term
| infection of FCV primarily occurs via... |
|
Definition
| ...aerosol (shed as aerosol in resp secretions from infected cat and then inhaled) |
|
|
Term
clinical dz in
a) adult cats with FCV
b) kittens with FCV |
|
Definition
a) rare, can have prolonged/persisitant infection, possib lasting for life
b) more severe |
|
|
Term
| prolonged/persisitant infection of FCV in adult cats may be possible due to... |
|
Definition
| ...Antigenic drift (Ab binding site changes) |
|
|
Term
| acute infections of FCV = |
|
Definition
1.mainly replicate in URT
2.transient virameia
3. can get joint infection = stiff and sore (reluctant to move)
4. fever, sneezing, coughing, inappentance
5. local inflam - incr secretions and sensitisation of lacal nerves = salivation, lacrimation and sneezing
6. rapid loss of basal epi = ulcers & blisters on tongue
7. pulm oedema with pneumonia in severe cases - fatal in kittens
8. cytokine and IFN release = fever, sickness behaviour, inappentance and depression |
|
|
Term
| majority of successful mutations in FCV are in... |
|
Definition
| ...hypervariable region of capsid genome (ORF 2 and ORF3 - mutation may have no effect or may affect Ab binding) |
|
|
Term
|
Definition
1. virus isolation
2. PCR (but if mutate where PCR binds = false negative :() = <100% releiable
3. serology (proove FCV by inhibiting it with antiserum) |
|
|
Term
|
Definition
| despite variability of FCV there are several monotypic vacc available. They broadly cause cross protective IgG. |
|
|
Term
| live attenuated FCV vacc admin = |
|
Definition
IM
DONT give intranasally, may be pathogenic admin this way! |
|
|
Term
| three types of FCV vacc available = |
|
Definition
1. live attenuated vacc
2. live temp attenuated intranasal vacc
3. inactivated vacc |
|
|
Term
| live attenuated vacc contraindicated in... |
|
Definition
|
|
Term
| how do you make live attenuated vacc for FCV? |
|
Definition
| grow on culture = virus gets efficient at growing on culture and decr ability to grow in vivo/host = attenuated |
|
|
Term
| advantage of live attenuated FCV vacc = |
|
Definition
| deeper cover as infects cells |
|
|
Term
| live temp attenuated intranasal vacc = |
|
Definition
rapidly protective
works by activating IFN = incr antiviral responses and primes innate responses = v quick protection
Also activates Abs : IgG |
|
|
Term
| what vacc is safe for preg cats? |
|
Definition
|
|
Term
| mec of inactivated FCV vacc = |
|
Definition
| no activity but still get Ab response. NO T cell response |
|
|
Term
| imp for vacc of FCV to keep up with... |
|
Definition
| ...viral antigenci drift! |
|
|
Term
|
Definition
| dont stop establishment of asympotmatic carrier cats following superinfection with wild type virus :( |
|
|
Term
| virulent systemic FCV affects adult cats or kittens more severely? |
|
Definition
|
|
Term
| symptoms of virulent systemic FCV = |
|
Definition
1. severe resp symptoms
2. perisitant fever
3. severe systemic inflam response
4. pancreatitis
5. hepatic necrosis
6. multiple organ failure
7. DIC and hameorrhage |
|
|
Term
| mortality of virulent systemic FCV = |
|
Definition
|
|
Term
| spread of virulent systemic FCV = |
|
Definition
limited, doesnt spread v well between cats = outbreaks are usually limited
with isolation and hygeine precautions FCV outbreaks can be controlled |
|
|
Term
| some studies have suggested what diff between normal and virulent systemic FCV? |
|
Definition
| virulent systemic FCV has more heat stable capsids = can infect core (not just URT like normal FCV) |
|
|
Term
|
Definition
| ...resp cells, skin, endothelium, macro and other epithelia cells |
|
|
Term
| what is often associated with FCV? |
|
Definition
| chronic lymphoplasmocytic gingivitis/stomatitis comples (ulcers/lesions with activated lymphocytes = v swollen mouth/gums) |
|
|
Term
| 2 sp effected by calici virus = |
|
Definition
cats (FCV)
rabbits (rabbit haemorrhagic fever virus) |
|
|
Term
| rabbit hameorrhagic fever virus is thought to be a mutation from... |
|
Definition
| ...non-pathogenic european rabbit calici virus |
|
|
Term
| rabbit hameorrhagic fever virus only infects... |
|
Definition
|
|
Term
| rabbit hameorrhagic fever virus 1st recognised in... |
|
Definition
| ...China meat rabbits in 1984, spread rapidly as rabbits had no innate resistance in china. Spread from china to Uk and many other countries |
|
|
Term
| UK rabbits may have some innate resistance to rabbit hameorrhagic fever virus.Why? |
|
Definition
| due to EU non-pathogenic strains of rabbit calici virus |
|
|
Term
| morbidity and mortality of rabbit hameorrhagic fever virus = |
|
Definition
high in rabbits over 2months old :(
doesnt effect neonates |
|
|
Term
| primary target of rabbit hameorrhagic fever virus = |
|
Definition
|
|
Term
| onet of dz of rabbit hameorrhagic fever virus = |
|
Definition
|
|
Term
| clincial signs of rabbit hameorrhagic fever virus |
|
Definition
1. severe lesions in lung(=pulm oedema), spleen, lymphoid tissue (=fever, lethargy, vascular necrosis), kidney and liver (extensive necrosis in liver)within 36hrs of infection
2. haemorrhage & DIC
3. death |
|
|
Term
| rabbit hameorrhagic fever virus spreads via... |
|
Definition
...faeces
resp secretions
passively by insects (felas, blowfly -insect feeds on infected rabbit and then virus in faeces of insect) |
|
|
Term
| has rabbit hameorrhagic fever virus been grown in culture? |
|
Definition
|
|
Term
| subacute cases of rabbit hameorrhagic fever virus = |
|
Definition
-jaundice
-weight loss
-depression
-near 100% mortality
-blood from mouth and nose |
|
|
Term
| what is rabbit hameorrhagic fever virus used for in australia and NZ? |
|
Definition
|
|
Term
| passive protection against rabbit hameorrhagic fever virus is transfered by... |
|
Definition
|
|
Term
|
Definition
1. inactivated virus from rabbit tissue (espec liver) - available in UK
2. recombinant virus based on outer capsid protien Virus Like particles (VLPs)is being developed. |
|
|
Term
| how is the recombinant virus against rabbit hameorrhagic fever virus made? |
|
Definition
| by expressing recombinant capsid protiens in a bacculovirus (an insect vector) safe as got no nucliec acid and therfore cant replicate in host |
|
|
Term
| how is the recombinant vacc safe? |
|
Definition
| safe as got no nucliec acid and therefore cant replicate in host |
|
|
Term
| recombinant virus induces... |
|
Definition
| ...strong neutralising Ab (and some T cell) response |
|
|
