Lecture 45 - ALT Virology 1 Flashcards
What 4 barriers must viruses overcome in the host
- anatomical/physical barriers
- intrinsic host defenses
- innate immune system
- adaptive immune system
what are the 4 genera of coronaviridae
- alpha
- beta
- delta
- gamma
how are new viruses generated from polymerase jumps
genomic RNA strands are next to eachother
polymerase begins on one strand, dissociates and reassociates at defined sit on second strand
Describe the pathogenesis of transmissible gastroenteritis virus (TGEV)
fecal-oral transmission
shed for 10 weeks
replicates in absorptive epithelial cells of small intestine
T/F: adult swine are able to repopulate their epithelial cells from the crypt
TRUE
what are the two possible outcomes of young pigs with TGEV
- Epidemic (fatal) - virus enters nonimmune herd, dependent on milk diet but reduced latase and poor cell repopulation
- Endemic (low mortality) - persistence of virus in herd due to continuous introduction of susceptible pigs, maternal antibody protects
how can TGEV be controlled
- VAX (MLV, Oral, natural)
- prevent introduction to herd
T/F: injectable vaccine > oral > natural for TGEV
FALSE
natural > oral > injectable
T/F: PEDV causes acute D+ in pigs of all ages
TRUE
T/F: clinical signs of Porcine Delta Coronairus and TGEV are indistinguishable
TRUE
what are the clinical signs of PDCoV and what animals can be infected
acute watery D+, V+, dehydration and mortality in chickens, turkeys, cattle, swine, and humans
What are the 3 distinct clinical syndromes of bovine coronavirus
- calf D+
- winter dysentry w/ hemorrhagic D+ in adults
- respiratory infection in all ages
how should bovine coronavirus be controlled
MLV before calving
bovine coronavirus is shed in ____ and ____
feces; nasal secretions
Describe turkey coronavirus
- affects turkeys of all ages
- high morbidity
- recovered turkeys are immune for life
- no treatment available - must depop and decontaminate
Describe canine coronavirus
- dogs of all breeds/ages
- high frequency seropositive
- colostrum protection
- causes V+, D+, dehydration
T/F: canine coronavirus can infect cats
TRUE
Describe Feline Coronavirus
- high frequnecy seropositive but rarely disease
- eventually develop FIP
- recovered cats are not immune
- 2 types = feline enteric coronavirus and feline infectious peritonitis virus
how does FIPV evolve from FECV
by mutation in infected cat, but does not spread
T/F: PCR can distinguish FECV and FIPV antibodies
FALSE
what serotype of FCoVs is recombinant
type 2 - has canine coronavirus sequences
what are the 3 forms of FIP
- effusive (wet)
2 non effusive (dry) - combo
summarize FIPV pathogenesis
- aeroso/oral FECV infects macrophages and mutates to FIPV
- form immune complexes on blood vessel
- effects depend on cell-mediated immunity
what is the result of no cell-mediated immunity in FECV exposure
intense inflammation (vessel wall damage, serum component leaks, pleuritis)
T/F: wet FIPV is from no cell mediated immunity
TRUE
what is the result of partial CMI in FECV exposure
weak monocyte and T cell response causes granulomas (dry form)
what is the result of effective CMI in FECV exposure
strong monocyte and T cell response causes no disease
what is FIPV treatment
palliative care
what are the 5 genera of reoviridae
- reovirus
- rotavirus
- orbivirus
- coltivirus (humans only)
- aquareovirus
T/F: reoviridae cause more enteric disease than respiratory disease
FALSE - more respiratory disease
what determines reovirus tropism
virus structure (pH stability, proteolytic activation)
describe the pathogenesis of porcine and bovine rotaviruses
- enters orally and passes into the intestine
- infects epithelial cells of the absorptive portion of villus (D+)
- epithelial cells from crypt repopulate villi
- Vaccinate
