Adenovirdae and Prions Flashcards
- Family Adenoviridae
Adenoviridae DNA viruses were first recovered from human _____ (____) tissue in 1953
Circo = _____ confirmaton
cyclo small known
both comprised of animal viruses
see first slide
adenoid, lump, circular
General Properties of Adenoviruses
- **_____ genera: Mastadenovirus, Aviadenovrus,
Atadenovirus, Ichtadenoviru, and Siadenovirus -
Virions are non-_____, _____ in outline, ______ symmetry. ___-___ nm in diameter
**One Fiber gene: _______
**Two fiber genes: ______
** Genome: _____, _____ molecule ___DNA and is ___-__ kb in size. The genome has _____ terminal repeats.
**Replication occurs in the _____ and forms _______ inclusion bodies.
Adenovirus _______ some types of RBCs
Some adenoviruses are _______ in laboratory animals but not in their _____ hosts
Five, enveloped, hexagonal, icosahedral, 70-90 , Mastadenovirus, Aviadenovirus, Single, linear, ds, 26-48, inverted, nucleus, intranuclear, agglutinates, oncogenic, natural
Mastadenovirus
Aviadenovirus
EM of?
Structure of Adenovirus-Virion Polypeptides
Capsid have ___ polypeptides
- Hexon protein
- Penton base
- Link adjacent facets
Bridge between hexons and VII
- Fiber
- Stabilize hexon
capsomere lattice
Core have ___ polypeptides
V Bridge between penton and core
VII Major core protein
TP Attach the viral genome to
nuclear matrix
Circularization of viral DNA
Primer for DNA replication
Mu Unknown function
7, 4
`
Old classification
chicken, goose, duck, turkey, pigeon
Relisten
New Classification
New classification from serology
Sequencing –> identify and cluster viruses together
Now based on new variants
Adenovirus Genome Structure and Organization
* __ origins of replication - ___
* Transcription Units
* __ “early” (E1A, E1B, E2, E3, E4)
* __ “delayed early” (IVa2 and IX)
* ___ major late -> (L1-L5
2 , ITR, 5, 2, 1
Adenovirus- replication cycle
- ____ and ___ phases of replication
- ____-prone process
-Inclusion bodies in ____
- ____ ____ determines target cell specificity & attachment
-Releases the viral capsid in the _____ then transferred into the ____
Viral DNA enters host cell ____
Early, late, Error, nucleus, Fiber protein, cytosol, nucleus, nucleus
CAR = ?
Coxsackieviruses/adenovirus receptors
Replication of Adenoviruses
** Fiber + CAR (coxsackieviruses/adenovirus) receptors
**Virus attaches to host receptors though the _____ _______ and is endocytosed into vesicles in the host
cell
* Disruption of the ______ releases the viral capsid in
the cytosol. released into the nucleus
* Transcription of early genes (__ genes), replication of the
DNA genome in the ____
* Transcription of late genes (___ genes), mostly encoding
for ______ ____
* Assembly of new virions in the _____
* Virions are released by ____ of the cell
fiber glycoproteins, endosome, E, nucleus, L, structural proteins, nucleus, lysis
CAR: Coxsackieviruses/adenovirus receptors
Types of Adenovirus infection
**I- Lytic: Results in cell ____; seen in ________ cells
**II-Latent/occult: Virus _____ in host cell; seen in _____ tissue, Groups ___ and __
**III- Oncogenic Transformation _______ cell growth and replication occur; Group ___ viruses in _____.
death, mucoepithelical, remains, lymphoid, B, C, Uncontrolled, A, hamsters
Name the types of Adenoviruses identified in dogs.
- Infectious canine hepatitis (canine adenovirus 1)
- Infectious canine tracheobronchitis (canine adenovirus 2).
Name the types of Adenoviruses identified in chickens.
- 12 serotypes of aviadenovirus: fowl adenovirus 1-11, 8a and 8b
- 1 serotype of atadenovirus: egg drop syndrome
- 1 serotype of siadenovirus: adenovirus-associated splenomegaly
Canine
Infectious Canine Hepatitis-(ICH) is a ______ contagious viral disease affecting the ____ and other _____. It is caused by _______, an _____ distinct virus. Dr. ______ distinguished it from CDV by inoculation into a ____ (resistant to ICH but not to CDV).
Spread only among domestic and wild dogs such as wolves, coyotes, and foxes and is not related to human hepatitis
Signs: range from mild to severe, and include pyrexia, nausea, vomiting, loss
of appetite, jaundice, light-coloured stool, and stomach enlargement
PM: vascular endothelial damage leads to petechial hemorrhage on mucous
membranes and sometimes skin
Swollen, mottled liver with rounded lobular edges and gall bladder edema
are characteristic features of ICH in dogs
Intranuclear inclusion bodies in hepatocytes
Highly, liver, organs, Canine Adenovirus type 1 (CAV-1), antigenically, Rubarth, ferret
Infectious Canine Hepatitis-(ICH)
Rubarth’s diseses
Clotting time based on liver function; hepatitis –> reflected on clotting time
Blue eye
Explained uveitis
***Pathogenesis of Canine adenovirus-1
* ___-___ infection followed by replication in ____ and ____ ____, other lymphatic tissues and viremia
* Virus then replicates in _____ cells in many organs, and in hepatocytes, endothelial cells of ____ glomeruli and
the ____ and _____
* As well as acute disease, persistent infection of the kidneys and immune complex formation can lead to ______
** Immune complexes also may cause ____ and ____ inflammation (____ eye)
* Persistently infected dogs may shed virus in their ____ for up to __ months
Oro-nasal, tonsils, Peyer’s patches, vascular, renal, cornea, uvea, glomerulonephritis, corneal, uveal, blue, urine, 6
What can be seen here?
immune complexes
Mechanism of Infectious Canine Hepatitis (ICH) induced blue eye in dogs
** Blue eye, if seen, occurs __-__ weeks after acute signs have ______ due to
immunologic damage of the _____ epithelium
** A: CAV-1 enter the eye via ____ tract then localized in _____ endothelial cells
causing ____.
*** B: CAV-1 specific _____ response increase in the ____ and reach to the eyes via _____ ____.
** C: CAV-1 free in the ____ and _____ cells and forming viral-antibody ____ complex
* D: Complement fixation on virus immune complex free and endothelial cells and viral
antibody complex formation and intranuclear inclusion body formation
* E: Close up showing of the endothelium and aqueous pump leading to influx of aqueous
to the cornea
* F: Corneal endothelial cell loss allows aqueous to enter the cornea causing corneal
oedema (Blue eye)
* G: Uveal inflammation may lead to blockage of the filtration angel and subsequent
glaucoma
1-3, disappeared, corneal, uveal, vascular, uveitis, antibody, blood, uveal, duct, aqueous, endothelial, immune
Blue eye in dogs
Diagnosis and control of ICH
** _______ Ab (Abs ≥ __:___) response after __ days post-infection may be sufficient to clear the virus from ____ and resist the extent of ____ damage.
** Abs ≤ __:___ leads to ________ hepatic ___.
** Partial immunity ≥ __:___ and ≤ __:____ may develop _____ hepatitis in dogs
* The homologous vaccine is stronger than the _____ vaccine
* Treatment with _____ and ____
Neutralizing, 1: 500, 7, blood, hepatic, 1:4, widespread, necrosis, 1;16, 1: 500, chronic, heterologous, atropine, corticosteroids
Egg drop syndrome (EDS)
* Infectious disease of ____ hens: ____ shelled and shell- _____ eggs
* The natural hosts : ____ and ____, but may cause problems in _____ of all ages
* EDS: more severe in ______ breeders and ____ egg layer strains, less so in white egg breeds
* EDS : first introduced into chickens through _____ vaccine
* Transmission by
-Any of the _____ methods of disease spread
- Infected birds excrete the virus in the ___
- _____ transmission is considered the primary mode of
spread.
laying, thin, less, ducks, geese, chickens, broiler, brown, contaminated, conventional, feces, Vertical
EDS belongs to adenovirus
eggLoss of pigmentation
Shelless or deformed eggs
Egg drop syndrome
Clinical signs : -Loss of _____ in pigmented eggs
-Thin shelled or shell less eggs
-***Egg production drops by ___ %
* Virus isolation: duck or goose embryos or cell cultures of duck or goose origin harvested allantoic fluid or cell culture
checked for HA activity chicken RBC
* HI or neutralization assays are specific for this virus and do not cross-react with antibodies from aviadenovirus infections
* Control:
-Avoid contact of diseased with other birds, especially waterfowl
-Disinfecting all equipment regularly
-Inactivated vaccines before they begin laying eggs
colour, 40
EDS
Fowl Adenoviruses-Inclusion Body Hepatitis (IBH)
Incidence: _____
** Hosts: ______ avian species of __ ages, ____-type chickens
*** Transmission: ____ -> Stress, sex hormones
* SPF eggs ??
* Lateral Highest titer in feces
* Birds can be infected with one serotype
* Some Cross protection between serotypes 3&4/2&11
* Multiple serotypes involved (2, 8, 9 and 11)
** Clinical signs: Low _____
* Sudden onset of mortality peaking after 3-4 d usually stopping on day 5
*** Pathology:
* - _____ or _____ hemorrhages in ___ and ____ muscles
Worldwide, Domestic, all, meat, Vertical, morbidity, Petechial, ecchymotic, liver, skeletal
Fowl Adenoviruses-Inclusion Body Hepatitis (IBH)
Intranuclear inclusion bodies
Intranuclear inclusion bodies in hepatocytes
-Large eosinophilic, rounded with a clear halo
-Occasionally basophilic
Right: nucleus at the right contains many virions and extremely
condensed chromatin
Basophilic intranuclear (IN) inclusions
***
Hydropericardium-Hepatitis Syndrome also known as ____ Disease in ___ chicken
* First identified in broilers in Pakistan in 1987
* 3-5 weeks old broiler chicken high morbidity and mortality (20-80%)
Characterized by lethargy, ____ feather, _____ ____ dropping
** Caused mainly by _____ ______ serotype __ and __
** Causes: ______ in birds
* Excessive fluids in the _____ sac (straw colored, jelly like fluid up to 20 ml)
* Enlarged ____ liver and pale kidney with generalized congestion
* Intranuclear inclusion bodies
Angara, broiler, ruffled, yellow mucoid, fowl adenoviruses, 4, 8, immunosuppression, Pericardial, friable
Hydropericardium-Hepatitis Syndrome, Angara Disease in broiler chicken
Diarrhea in top right
Cervine Adenovirus (Odocoileus Adenovirus-1
Epizootic severe diseases in black tailed deer
A: Severe pulmonary edema in experimentally infected
black-tailed deer
B-Intra-nuclear inclusion bodies in the lining of an
affected arterioles
Turkey Adenovirus-3
* Hemorrhagic Enteritis of Turkeys
* Marble Spleen Disease of Pheasants,
* Avian Adenovirus Splenomegaly Viruses
- Hemorrhagic enteritis -Turkey siadenovirus A - acute infection of turkeys > 4
weeks age - Characterized by splenomegaly and intestinal hemorrhage
- Signs: depression, bloody droppings, death, usual mortality 1-3%
- Serologically indistinguishable viruses cause marble spleen disease of
pheasants and avian adenovirus splenomegaly in broiler chickens - Pathognomonic lesions: prominent macrophage-phagocytic cell hyperplasia
and intranuclear inclusion bodies in the spleen, distended bloody intestines,
and pseudomembranous (fibrinonecrotic) inflammation in the duodenum - Vaccine - live-attenuated virus produced either in turkey spleen cells or in
turkey B lymphoblastoid cells - administered via drinking water - Optimal vaccination age – 4-5 weeks – as maternal antibody interferes
Turkey Adenovirus-3
Quail Bronchitis Virus – Fowl Adenovirus A
* Worldwide
* Young ones more susceptible – mortality 100% in young quails
* Mortality 25% in 4 weeks or older
* Signs: respiratory distress, open-mouth breathing, nasal
discharge, coughing, sneezing, rales, lacrimation, and
conjunctivitis
* Characterized by: necrotic or hemorrhagic tracheitis, with
distinct large basophilic intranuclear inclusions, air sacculitis,
multifocal hepatic necrosis, and gaseous, mucoid enteritis
* No long-term shedding and immunity is long-lasting
Quail Bronchitis Virus – Fowl Adenovirus A
FAdV-laboratory diagnosis
* Isolation and identification of adenovirus
-Specimens collected from feces, pharynx, affected organs
-Isolation in CEL or CK cells
-Identification by neutralization test
* Serology
The main problem is interpretation of the results
Abs are common in healthy and diseased birds
Birds are frequently affected by a number of serotypes
Humoral Abs give no indication of local immunity at mucosal surface
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Diagnosis of Adenoviruses
* Proper sampling
* History, clinical picture, PM
* Laboratory diagnosis
-Isolation of virus from nasal secretions, blood, urine, or affected tissues
-Microscopic examination of the liver reveals a characteristic pattern of
tissue damage and intranuclear inclusion bodies in infected hepatocytes
* Immunofluorescence staining
* Control: largely based on vaccination and has been very successful
Porcine Adenovirus (PAdV)
** Porcine adenovirus (PAdV) is a non-_______ DNA virus in the genus ______, family _____.
**** currently ___ porcine species and ____ serotypes recognized: ?
**PAdV generally causes _____ infections and is commonly isolated from the _______ tract of typical swine.
** PAdV can induce ____ and has been isolated in association with ?
PAdV can be detected in fecal and intestinal cultures using negatively stained transmission electron microscopy (TEM).
Immunofluorescence antibody (IFA) assays, complement fixation, direct fluorescence antibody (FA), and gel diffusion
precipitation tests are all capable of detecting PAdV antigen and can be useful in confirming infection.
* A rise in anti-PAdV antibodies in the presence of clinical disease is suggestive of clinical disease. Serological methods
include virus neutralization or indirect fluorescent antibody testing
** There is ___ ______ for PAdV infection
enveloped, Mastadenovirus, Adenoviridae, 3, five, PAdV-A (serotypes 1-3); PAdV-B (serotype 4); and PAdV-C
(serotype 5), subclinical, gastrointestinal, enteritis, encephalitis, nephritis, respiratory disease, and
reproductive disorders, no treatment
Cervine Adenovirus (Odocoileus Adenovirus-1
Epizootic severe diseases in black tailed deer
Cervine Adenovirus (Odocoileus Adenovirus-1
Epizootic severe diseases in black tailed deer
A: Severe pulmonary edema in experimentally infected
black-tailed deer
B-Intra-nuclear inclusion bodies in the lining of an
affected arterioles
Adenoviral conjunctivitis
Early conjunctivitis (left) and Bilateral conjunctivitis (right)
Adenovirus for Gene Therapy
- ________ deficient
- ___ kb foreign DNA
-High ____ production
-Infect a ____ of tissues
-High expression in ___-____ tissues
replication, 8, titer, variety, non-replicating
Prion: Pretentious infectious particles
The Protein-Only Hypothesis
-Proposed by _______ ______
-Received ___ Nobel Prize in Physiology or Medicine for his work wanted to purify the mysterious “virus” causing ____ in 1982: named the agent a PRION
-*** Prions contain ____ ____ amino acids twisted into _____ telephone chord-like coils known as _____, with tail of more aa
- Prion is ____ times ___ in size than any known virus
- The great debate: How can a protein devoid of nucleic acid
replicate and cause disease???
Stanley Pruisner, 1997, scrapie, 200-250, three, helices, 100, less
What caused the first case of BSE?
* There are three possibilities:
* BSE is a ____ form of sheep ____
* BSE arose from a ____ ____ in a single cattle
* A single ‘___’ misfolding of PrP to PrPSc caused the
disease - ‘spontaneous’ prion diseases have occurred in humans and this seems the most likely candidate
bovine, Scrapie, genetic mutation, spontaneous
Prions associated with disease (encephalopathy) are modified form of
-Host-encoded glycoprotein – ____ to ____ which is the “infectious” form
The mutated and infectious form is built from the same aa but have different ____
PrPC, PrPSc, shapes
No antibiotics can cure disease caused by prions
They are not typical of a prokaryotic organism or a eukaryotic
organism
All that is present in this pathogen is the protein PrPSc, the
mutation of PrPC
PrPSc is resistant to any form of digestion
Prions are non immunogens and do not induce an immune
response
Prions are not easy to decompose biologically
They are resistant to high temperatures & disinfectants
Infectious (?)/ Catalytic protein
-Resistant to DNAse and RNAse
-Resistant to Proteinases
high meat diet for pregnant animals –> Ca and P?
Prions are ?
-Transmissible
-Filterable
-Resistant to heat, UV and ionizing
radiation
-Protein, no nucleic acid
“Prion” agent cause TSE
(Transmissible Spongiform Encephalopathies)
Agent is resistant to:
* Heat - boiling and cooking under pressure
* Steam under pressure – rendering process
* Radiation – irradiation with UV and X-rays
* Disinfectants
* Proteases
* DNAse and RNAse
* Burn meat to ash and agent will survive
Conversion of PRPC into PRPSCC
What is the function of PrPC?
**_____ in size, _____ protein associated with ___ cell membranes - NO _____ ____.
* Encoded by host genes - normal cellular product
* **Human and bovine prion proteins differ at ____ ____ ___ residues
* Sheep and bovine prions differ at only 7 A.A. residues
What is the function of PrPC?
* PrPC may play an important role in _____ of neurons from ____ stress.
*PrPC 0/0 knockout (null) mice and cattle are resistant to prion infections
* PrPC null mice are more susceptible to acute seizures
Small, glycosylated, brain, NUCLEIC ACID, 30 A.A. , protection, oxidative
Could display clinical signs after a few years or later on
do not memorize
How does it spread from animal to animal?
* Feeding cattle animal bi-products such as meat-and-bone meals that has an infected prion
causes the infection in the cattle
* **The prions are concentrated in the ____, and ____ ___ of these animals
** No evidence that it is concentrated in the ____ mass of cattle, and they are considered
safe as long as they are not in contact with the ___ and ____ ____ during the ____
process
brain, spinal cord, muscle, brain, spinal cord, slaughter
Sources of the BSE
Sheep with Scrapie used in Meat and Bone Meal (MBM)
known as “Offal”
MBM fed to cattle
Infected Beef eaten by humans
Not affected by cooking
Sources of the BSE
After these infected sheep having died , their brains and other
sheep byproducts infected with scrapie is used to feed cattle
with the meat and bone mill (MBM)
Describe BSE infection cycle
called scrabies in sheep
Sources of BSE
***Sheep with ____ used in ___ and ____ Meal (MBM) known as “____”
_____ fed to cattle
Infected Beef eaten by ___
Not affected by ___
Scrapie, Meat, Bone, Offal, MBM, humans, cooking
After these infected sheep having died , their brains and other
sheep byproducts infected with scrapie is used to feed cattle
with the meat and bone mill (MBM)
Phases of BSE infection in cattle
The first phase:
Low infectivity rate, and the cow does not pose a
large threat to humans at this level
The second phase:
Symptoms are not evident, but the infectivity level
is very high
The prion agent is abundant in both the spinal
chord and the brain – the cow is a risk to public
health
The third phase:
Clinical symptoms, & then death follows shortly
Mad Cow Disease (MCD)
**Scientific Name: ?
**It is found on ?
***Sheep: ?
**There is a human form called ?
Mad cow disease was first identified in Britian in 1985
The outbreak infected more than 100,000 cows across Europe in the mid-1990s
The recent resurgence of the disease comes despite widespread beef import restrictions and other measures
intended to protect the food supply
Bovine Spongiform Encepalopathy, any type of cloven hoofed animals such as: pigs, sheep, and cattle, Scrapie Spongiform Encepalopathy., Creutzfeldt-Jakobs Disease
Mad Cow Disease (MCD)Clinical Signs
Cattle affected by BSE experience _____
degeneration of the _____ system
Affected animals may display changes in _____, such as nervousness or aggression,
abnormal ____, ____ and difficulty in
rising, decreased ___ production, or loss of body ___ despite ____ appetite
The clinical signs are?
progressive, nervous temperament, posture, incoordination, milk, weight, continued, Apprehension
Hyperaesthesia
Frequent licking with progressive paresis, & ataxia
No blindness or circling is seen
At the London Zoo it was first noticed by the public
when a Puma became ataxic.
Mad Cow Disease (MCD)Clinical Signs
Mad cow disease
Scrapie in sheep
* Scrapie: _____ sensation in the animals
* Common clinical signs in sheep
-Excessive ___ smacking
-Altered ___
- ______ collapse
Itching, lip, gaits, Convulsive
Scrapie in sheep
Some histological findings on post mortem - scrapie
Histological findings include
** _______ of the neurons and neuronal _____ substance in cerebella/cortex
**Perivascular fibrils of ____ in which ____ can be demonstrated by immunostaining
and congo red bifringence
_______ infiltration
Vacuolation, ground, amyloid, PrPsc, Astrocyte
Detection of BSE in the infected brain tissues
-Spongiform changes in the grey matter
-Detection of abnormal protein
-IHC: gold standard technique in the detection of BSE antibodies in tissues
important!!!!!
-Spongiform changes in the grey matter
-Detection of abnormal protein
-IHC: gold standard technique in the detection of BSE
antibodies in tissues
BSE- brain damage- Pathology
A: Typical spongiform change in neurons (H&E)
B: Spongiform change and astrocytic hypertrophy and hyperplasi
Prevention and control of BSE
Don’t feed cattle animal bi-products
Watch to make sure you are feeding your animals safe feeds
Always vaccinate cattle properly
* At Present, there is no Cure for
* -the Mad Cow Disease (Bovine Spongiform Encephalitis)
* -and for the Creutzfeldt-Jakob Disease
* Immediate notification of authorities
-Federal (Area in charge (ACIC)
-State (State veterinarian
* Implement quarantine measures
- Bovine herpesvirus-2 causes:
A. Lumpy skin disease
B. Pseudo-lumpy skin disease
C. Severe ulcerations on cow teats
D. B and C
D. B and C
- Which of the following viruses is implicated in neoplastic transformation of cells?
A. Porcine herpesvirus 1 (Aujeszky’s disease virus)
B. Ovine herpesvirus 2 (OHV-2)
C. Gallid herpesvirus 2 (Marek’s disease virus)
D. Bovine herpesvirus 2 (BHV-2)
C. Gallid herpesvirus 2 (Marek’s disease virus)
