Adenoviridae Flashcards
Viruses in the Family Adenoviridae are Enveloped or non-enveloped?
Non-enveloped
What type of symmetry do adenoviruses have?
Icosahedral
The capsid shell of adenoviruses has how many hexon subunits and how many trimers?
720 hexon subunits
240 trimers
How many vertex penton capsomers protrude from adenovirus capsids?
12
T/F: Adenovirus genome is segmented, linear double stranded DNA.
False, it is non-segmented
How are the virons of adenoviruses released?
Cell lysis
Histologically, what would you see in relation to adenovirus replication that is often in para-crystalline arrays?
Intranuclear inclusion bodies containing large numbers of virons
What do many adenoviruses cause with the penton fibers located on their capsid?
Hemagglutination
Can adenoviruses be oncogenic?
Yes
T/F: Adenoviruses are stable in the environment.
Yes, but are easily inactivated by disinfectants
How large is the host range of most adenoviruses?
Narrow
What are two common pathogeneses of adenoviruses?
- actue respiratory disease
2. gastroenteric disease
Which parts of the capsid cause inhibition of cellular RNA export to nucleus, inhibition of protein synthesis, cell rounding and tissue damage?
Penton and fiber proteins
What are 4 ways that adenoviruses cause immunosuppresion?
- Inhibition of MHC I antigen transport by E3/19K
- Inhibition of TNF induced apoptosis by E3/14.7K
- Blocking of INF-induced inhibition of viral protein synthesis
- Modulation of antiviral inflammatory response via inhibition of NFkB transcription
T/F adenoviruses can undergo long latency periods.
True, this is especially important in immunocompromised and immunodeficient patients.
Which adenovirus gene products are associated with
oncogenesis?
E1A
E1B
What are the 2 important genera within adenoviridae and what animals do they affect?
- Mastadenovirus- mammals
2. Aviadenovirus- avian
What is different about the penton fiber of aviadenoviruses compared to mastadenovirus penton fibers?
Aviadenovirus penton fibers are bifurcated.
What disease caused by and adenovirus is sometimes referred to as Rubarth’s disease?
Infectious Canine Hepatitis
What disease was Infectious Canine Hepatitis distinguished from in 1947. Ferrets are more susceptible to this disease than ICH.
Canine Distemper
Etiological agent of ICH
Canine adenovirus -1 (CAV-1)
Route of transmission of ICH
Oronasal
Sites of replication for CAV-1
Macrophages Kupffer cells Hepatocytes Vascular endothelium of organs including CNS Parenchymal cells of organs and tissues
How long will CAV-1 be shed in the urine of an infected animal after acute infection?
6-9 months
What 3 organs are usually the first to undergo cellular injury due to the cytotoxic effects of CAV-1?
- Liver
- Kidney
- Eye
T/F An antibody titer greater than 500 is usually sufficient to clear CAV-1 virus from blood and liver.
T
What will happen to an animal infected with CAV-1 with a constantly low antibody titer?
centrilobular to panlobular hepatic necrosis
An animal has an antibody titer of 258 for CAV-1. What is the expected outcome in terms of pathogenesis and immunity.
Partial immunity
Chronic active hepatitis and fibrosis
What is the main consequence for the kidney in an animal infected with CAV-1?
Glomerulonephritis
Concerning the eyes, what do we see in 20% of natural infection cases and 1% after vaccination.
blue eye (Corneal edema)
How many days post infection would we see “blue eye” in an animal infected with CAV-1?
Day 7
Acute clinical signs of ICH
Fever, depression, anorexia, vomiting, abdominal pain, hepatomegaly, hypermia or petechiae in oral mucosa, pale membranes, jaundice, active lymphatics, subq edema, corneal edema
Necropsy signs of ICH
Paint brush hemorrhage on gastric serosa, lymph nodes, thymus, pancreas and subq tissue.
Centrilobular hepatonecrosis
grayish-white foci in the renal cortex in recovered or chronic animals
Liver histopathology of ICH
Liver has neutrophilic and monocytic infiltration
hepatocellular intranuclear inclusions present
Hematological signs of ICH
Leukopenia Increased ALT, AST due to hepatic injury Proteinuria extended prothrombin duration thrombocytopenia
Treatment for ICH
Supportive care, limit secondary infection, fluids, control hemorrhages
Is CAV-1 or CAV-2 the preferred vaccine?
CAV-2, Provides cross-protection against CAV-1 with less incidence of corneal edema associated with CAV-1 vaccine
When should puppies be vaccinated for ICH?
Primary 6-12 weeks
Revac 14-16 weeks
What is the common name for Canine Infectious Tracheobronchitis (ITB)?
Kennel Cough
What is the bacterial agent associated with CAV-2 in animals with Kennel Cough?
Bordetella bronchiseptica
Is ITB very contagious?
Yes, it is aerosolized.
What signs do we tend to see with “uncomplicated” ITB infections?
Coughing-harsh and dry
Rhinitis
serous nasal discharge
occasionally conjunctivitis is seen
Signs of “Complicated” ITB
Severe pneumonia or bronchopneumonia
Diagnostics for ITB
PCR, serology, Virus isolation
Treatment for ITB
Cough suppression, bronchodilation
In equines, what do we typically see with most equine adenovirus infecitions?
Usually asymptomatic, can present as mild upper or lower respiratory disease
What other disease is associated with severe EVA-1 induced respiratory disease in foals?
SCID (Severe Combined Immunodeficiency)
Foals with severe EAV infections associated with SCID die within _______ months of age.
3
Clinical signs of EAV infections in SCID foals
Severe bronhilitis, pneumonia, Respiratory distress
EAV infections can become generalized and infect other organs.
Diseases caused by Avian adenoviruses in chickens
Inclusion body hepatitis
egg drop syndrome
