What is the shape of coronaviruses nucleocapisid?
And the shape of toroviruses?
Coronavirus = helically coiled Toroviruses = donut shaped - tightly coiled tubular nucleocapsid
Where does the envelope of a coronavirus come from?
Budding from the ER
How does a coronavirus leave the host cell?
Exocytosis
Where does a coronavirus replicate within the cell?
cytoplasm
What coronavirus group is Transmissible gastroenteritis in pigs (TGE) in?
Group 1 A
What are the two forms of TGE?
Which one has a higher mortality?
Epidemic (higher mortality) and Endemic
When do you see the Epidemic form of TGE?
Epidemic: Virus spreads through a herd that has had NO PREVIOUS EXPOSURE
Usually occurs in the winter time
High morbidity and high mortality
When do you see the Endemic form of TGE?
Occurs in herds that have partial protection (from previous exposure)
OR
As a concurrent respiratory coronavirus
T/F: Porcine respiratory coronavirus (PRCV) is a mutation of TGE
TRUE
A deletion mutant of TGE virus
Where is TGE a common problem?
The US
What is the most common MOT for TGE?
Fecal - oral***
**Adults who are subclinical tend to get piglets infected
Direct contact, aerosol, fomites are other modes
Where in the body does TGE replicate and what does it cause?
Replication occurs in the SMALL intestine vili
They get blunted, atrophied, and fuse together –> no absorption
What are clinical signs of TGE? Who is gets infected?
Severe dz in piglets
Profuse DHR/Vomiting
Depression, watery yellow/green DHR
clots of undigested milk in intestines and feces
Intestines accumulate gas due to rotting food
What prevention measures can be performed for TGE?
Vaccinate sows, practice all in - all out methods, keep pigs in groups with the same age groups
T/F: Porcine Epidemic Diarrhea (PED) is a variation of TGE
FALSE!!! - these viruses are not related, but they are clinically indistinguishable
What group of coronaviruses does PED belong to?
Group 1 B
What is the MOT of PED?
Fecal-ORAL
T/F: PED causes diarrhea in primarily piglets
FALSE
PED causes diarrhea in adult pigs and piglets
Morbidity = 100% Mortality = 30-100%
T/F: Porcine Epidemic Diarrhea is not a virus that occurs often in the US
FALSE
What does Porcine hemagglutinating encephalomyelitis virus cause?
Vomiting and wasting disease in pigs
What is the MOI for porcine hemagglutinating encephalomyelitis virus?
Aerosol and contact with nasal secretions
What does porcine hemaglut. encephalomyelitis cause in piglets less than 4 weeks of age? And in piglets less than 2 weeks of age?
Less than 4 weeks = Vomiting and wasting
less than 2 weeks = non-suppurative encephalitis
What is the progression of porcine hemagglutinating encephalomyelitis?
Replication in the nasal mucosa –> Replications in lungs/tonsils/small intestine –> Spreads to CNS and PNS–>Replication in brain stem/cerebrum/cerebellum –>encephalomyelitis OR disruption of gastric emptying –> vomiting and malnutrition
What are clinical signs observed in a piglet with vomiting and wasting dz?
Constant retching vomiting - yellow/green material that is highly odorous, anorexia, dehydration, cyanosis, food will rot in intestines and accumulate gas
Who does bovine corona virus affect?
Calves 1d to 3 months old (mostly between 1-2 weeks of age)
Where in the body does bovine corona virus replicate and what are its implications?
Replication occurs in the small and large intestine:
Atrophy of vili and crypt epithelium damage leads to malabsorption and increased secretory function –> Profuse DHR - sometimes hemorrhagic
Besides DHR, what other clinical signs might you see in a calf infected with bovine corona virus?
Upper respiratory infection - minor effects
T/F: Bovine corona virus is usually a self limiting virus
TRUE
What time of year is it most common to have outbreaks of bovine coronavirus and how is it transmitted?
outbreaks are most common in the winter
fecal oral transmission
Is there a vaccine for bovine coronavirus?
YES
Combo vax with other pathogens - should be admin to pregnant cow - to passively pass immunity to calves
Who does winter dysentery affect?
Adult cattle - specifically cows who have just given birth or are lactating
Explosive outbreaks in winter
Watery - green/black dhr
T/F: winter dysentery is closely related with bovine coronavirus
TRUE
It is believed to be a mutation of the bovine corona virus - similar, but antigenically different
T/F: Winter dysentery also caused perfuse DHR in calves
FALSE
young calves will have mild signs if any
what percentage of cats exposed to feline corona virus will end up contracting FIP?
Only 1-3%
Aggressive mutations of the feline enteric corona virus occur, causing FIP
T/F: Feline enteric corona virus invades macrophages
FALSE
only FIP
Where do feline enteric coronaviruses replicate?
intestine
What percentage of cats are clinically effected when exposed to feline enteric corona virus?
70% will contract the mild form - causing dhr
How does a cat become a persistent carrier of FIP, and what percentage are?
5-10% of cats that recover from the mild enteric form of feline coronavirus will become persistent carriers
What is the MOT for feline corona virus?
FECAL ORAL** most common
inhalation and transplacental possible
What surface proteins does FIP use to enter macrophages?
CD13
Once in macrophages, how does FIP progress throughout the body?
Infected macrophages travel throughout the body and trigger inflammatory cytokines –> They also create granulomas in the endothelium of blood vessels in organs such as; liver, spleen, kidneys
FIPV infected macrophages in LN will release TNF; causing apoptosis of lymphocytes
IL10 will change the cellular response to humoral –> antibodies will attract infected macrophages–> leads to more infected cells/macrophages
T/F: A cat with a weak cellular response, but strong humoral response should be able to fight an FIP infection
FALSE
A STRONG cellular response and WEAK humoral response would be ideal for fighting an FIP infection
What a cat has a ________ cellular response and _____ humoral response, they will contract the _____ form of FIP.
When a cat has a WEAK cellular response and STRONG humoral response, they will contract the WET form of FIP.
Wet- peritonitis, pleuritic, vasculitis, ascites, glomerulonephritis
Intermediate cellular and humoral response will lead to what form of FIP?
Dry form: small ocular lesions, granulomas in LN and Kd, CNS involvement
What diagnostic test is performed to confirm FIP?
Rivalta test (can use sample of effusion)
other tests: IFA, RT-PCR
What diseases does Avian Infections Bronchitis (IB) cause?
Respiratory dz Nephrotopic - renal failure uterotropic - decreased egg production/quality enterotropic proventricular
What protein involved with avian IB is antigenically important, and induces the protective immunity?
S protein
MOT for avian infectious bronchitis?
Inhalation
aerosol
direct contact and fomites
T/F: Avian infectious bronchitis can cause renal failure and gout
TRUE
Who should be vaccinated for infectious bronchitis?
Broilers (usually get live vax)
Breeders and layers (usually get killed vax)
T/F: Chickens that recover from Infectious Bronchitis will become carriers
TRUE
What is unique about the nucleocapside of Toroviruses?
They are shaped like a half donut
What does Bovine Torovirus cause?
aka Breda virus
Causes perfuse diarrhea in calves (up to 4 months of age - 2-5 day old calves most commonly)
What damage does bovine torovirus cause and how is it transmitted?
It replicates in the lower half of the villi and the crypts in the jejunum - ileum, also crypt epithelium of the colon and cecum –> causes villious atrophy, crypt hyperplasia, and fused villi –> malabsorption dhr
Fecal-oral route and nasal
