Reovirdae Birnaviridae Pibicornavirdae Flashcards by Christine Parascandola

Reo: “Respiratory Enteric orphan
* “orphan virus“ viruses have been _______, but are __ associated with any known disease.

observed, not

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Classification of the family Reoviridae
_____ dependent RNA polymerase
The family Reoviridae is made up of Two subfamilies:
1. ?
2. ?

RNA, Sedoreoviriae, Spinareovirnae

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General Properties of Reoviruses
* _________ –shaped medium 80 nm diameter
**** Non-_________ has ___, and ____ capsid layers (____ and ____ core)
* Each of the two capsids has ______
symmetry
**** Outer capsid (VP__, VP___)
* **Inner core: VP__
* Outer core: VP__
** Transcription complex: (VP__, __, and __)
** _____ segmented _____-stranded RNA
** Genome: have between __ and ___ segments
** Genome size varies from ___ to __ kbs
** Replication - Full ______ replication

Spherical, enveloped, outer, inner, inner, outer, icosahedral, 2, 5, 3, 7, 1, 4, 6, Linear, double, 10, 12, 15, 27, cytoplasmic

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What virus is pictured below?

Reoviruses

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What virus can be seen below?

Reovirus

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Reovirus genome structure

***___-___ segments __RNA
Non-enveloped-RNA viruses
possessing a double shelled capsid
Packaged 1 copy per particle
Transcripts represent genome-length
mRNAs
Genome segments can reassort
between related strains
** _______, ds-RNA - 10 (___) /11 (_____)
segments in
three distinct size classes:
**L - encodes proteins designated __
**M - encodes proteins designated __
***S - encodes proteins designated __

10, 12, ds, Segmented, Reo’s, Rota’s, (lambda) λ, μ, σ (sigma)

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What virus is pictured below?

Reovirus

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Comparison of two distinct core particle morphologies (spiked and unspiked) present
amongst genera within the subfamilies of the Spinareovirinae and Sedoreovirinae

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Each of the viruses are all apart of the ________ family, but they all look different.

Reovirus

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In the Reovirus replication cycle, the virus enters the host cell via ____________.

Endocytosis

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Describe the reovirus replication cycle
Virus attach to receptors, endocytosis virus in the endosome and the
copying the viral genome and viral protein, assemble together and release via
leading to the
release into the cytoplasm and start
method mediated by
There are viral inclusion bodies in the
Back

pH decreases, acidification, budding, NS3, cytoplasm

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1- African Horse Sickness Virus (AHSV)
* African horse sickness is a serious, often fatal disease of ?
** Serotype ___ is widespread in endemic regions, while serotypes __ to __ are
found only in limited geographic areas.
** Spread by infected _____ (______ _______) in the genus _______ and is not contagious by casual contact
* The disease primarily occurs in Africa, but outbreaks have been reported in Egypt, parts of the Middle East, Spain, Portugal, Morocco, Pakistan and India.
** Virus is inactivated by
– _______ (temps greater than _____)
– pH less than __, or ___ or ____
– _____ disinfectants
** Rapidly destroyed in carcasses that have undergone?
* AHSV: infects horses, donkeys, mule, zebra

horses, mules, and donkeys

9, 1, 8, insects, biting midges, Culicoides, Heat, 140oF, 6, 12, greater, Acidic, rigor mortis

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AHSV-OIE Disease Distribution Map
* Endemic in ?
* Outbreaks
– Southern and northern Africa
– Near and Middle East
– Spain and Portugal

sub-Saharan Africa

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AHSV-Succeptability /IP/Morbidity/Mortality
* Varies with species, previous immunity, form of disease
* Mortality based on _______
– Horse particularly susceptible
– Mortality of infected animals
* Horses: ____%
* Donkeys: ___%
* Mule; ___%
-Dogs may seroconvert through arthropod bites
Forms of the disease and associated mortality rates

species, 95, 50, 10

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The per acute form of African Horse Sickness virus is the?
The subacute form of African Horse Sickness virus is the?

pulmonary form, edematous/cardiac

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***I- AHSV-Peracute - Pulmonary Form
* Acute _________
* Sudden, severe ________ distress
* Dyspnea, tachypnea, Profuse sweating, spasmodic coughing
** _____ ___________ nasal exudate
* Rapid death (few hours)

fever, respiratory, Frothy, serofibrinous

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***II-AHSV-Subacute Edematous - _____ Form
** Edema of ________ fossae, eyelids
* Cheeks, lips, tongue, intermandibular space
* Neck, thorax, chestNot in lower legs
* If animal recovers, swellings subside over 3-8 days

Cardiac, supraorbital

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***III- AHSV-Subacute - ____ Form
* Cardiac signs usually subclinical Followed by severe respiratory distress
* Mild respiratory signs
* Followed by edema and death
** Mortality __-__%

Cardiac, 70-80

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IV-AHSV-Acute - ___ Form
* Pulmonary and cardiac forms
* Cardiac signs usually subclinical followed by severe respiratory distress
* Mild respiratory signs followed by edema and death

Mixed

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What virus can be seen below?

AHSV

Top two rows = AHSV -I
Bottom row = AHSV -II

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AHSV-Diagnosis
* Clinical signs
– **__________ swelling is characteristic
* Clinical signs
– Supraorbital swelling suggestive for AHSV
* Laboratory diagnosis
– Virus isolation & identification
– Serology
– Antigen detections (ELISA, IF)
– ***-__________ __________ inclusion bodies

Supraorbital, Granular intracytoplasmic

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What virus is this horse suffering from? What can be seen in the histological image above?

AHSV - Severe edema of the eyelid Granular intracytoplasmic inclusion bodies

AHSV- control measures ** ________control  Spraying all Equidae with insect _____ Insecticides  Vaccination of susceptible animals (preferably with the monovalent vaccine for the outbreak serotype)

Vector, repellants

3- Bluetongue Virus (BTV) causes what diseases?

* Sore Muzzle, Pseudo Foot-and-Mouth Disease, Muzzle Disease

Blue tongue virus was First described in

South Africa

Blue tongue virus has a ______________ distribution

worldwide

BlueTongue Virus: a ____-_________, ______-borne, viral disease of _________. It primarily affects _____ and _____ _______, with asymptomatic infections occurring in ?

non-contagious, insect, ruminants, sheep, wild, ruminants, cattle, goats, deer

Bluetongue virus has how many serotypes worldwide? Morbidity can be as high as _____% Mortality is usually __-___%

24 serotypes identified worldwide, 100, 0-30

BTV : transmitted by _______ ______ in the genus ________ Principal vector (U.S.) * C. variipennis var. sonorensis In utero, Mechanical, Venereal?

biting midges, Culicoide

BTV: is not a _________ disease; the virus can be transmitted to the ______ in utero or spread ___________ on surgical equipment and needles

contagious, fetus, mechanically

Although BTV can be found in ______, venereal spread does not appear to be a major route of infection

semen

BTV has been isolated from all countries except _________

Antarctica

BTV

Sheep: Severity of disease varies based on?

* Breed * Strain of virus * Environmental stress

BTV - USA Only one monovalent live vaccine against serotype-___

Principal vectors of BTV in US - ?

C. sonorensis and C. insignis

BTV clinical signs

Clinical signs - reflect the damage that this virus causes to vascular endothelium and the resultant changes to capillary permeability and subsequent intravascular coagulation. Fever, edema of lips, nose, face, submandibular area, eyelids, and sometimes ears; congestion of mouth, nose, nasal cavities, conjunctiva, and coronary bands; and lameness and depression

In North America, ______ ______ ______ (Odocoileus virginianus), ________ _______ (Antilocapra americana), and desert bighorn sheep (Ovis canadensis) are also susceptible to _____ infection

white-tailed deer, pronghorn antelope, BTV

White-tailed deer and pronghorn antelope infected by BTV develop ?

severe hemorrhagic disease leading to sudden death

These ruminants are suffering from what viral infection? Describe the clinical signs seen.

In sheep, the clinical signs may include fever, excessive salivation, depression, dyspnea, and panting. The muzzle, lips, and ears are hyperemic, and the lips and tongue may be very swollen. The tongue is occasionally cyanotic (“Blue tongue”) swollen, and protrudes from the mouth.

In cases of BlueTongue Virus, The coronary bands on the hooves are often _______ and inflamed, and the hooves are painful; lameness is common.

hyperemic

BTV incubation period is ?

5-10 days

What condition did this animal suffer from?

Bluetongue virus

In the case of blue tongue virus, during post mortem examination you can see?

Tongue – Swollen, protruding – Cyanotic = “blue-tongue”

In the case of blue tongue virus, during post mortem examination you can see?

Face and ears edematous * Dry, crusty exudate on nostrils

In the case of blue tongue virus, during post mortem examination you can see?

Coronary bands hyperemic This is shared with foot and mouth disease

In the case of blue tongue virus, during post mortem examination you can see?

Hydranencephaly

Pregnant ewes infected during the first trimester may - abortion -give birth to “dummy” lambs (dull, unresponsive) Erosions, crusts around nose and teats

How do you diagnose BTV?

* History * Clinical signs – Insect activity – Wasting or foot rot * Laboratory – Virus isolation – ELISA, IFA, VN – PCR – Serology, complement fixation – Examination of proteins

How do you control BTV?

* Control of vectors by insecticide * Quarantine and movement controls – Prevent spread of virus * Vaccines are available, but are specific for each serotype

What are the differential diagnoses for BTV?

Epizootic Hemorrhagic Disease (EHD) Belongs to ________ and has __ distinct serotypes (only two of these (?) occur in the USA)

Orbivirus, 8, New Jersey and Alberta

EHD is an _____, ___________, often _____ viral disease of some ?

acute, infectious, fatal, wild ruminants

Both BTV and EHD are antigenically ________

distinct

EHD The mode of transmission of EHD in nature is via a ________, _______ fly or ______

Culicoides, biting, midge

What is the disease is the animal suffering from in the picture below?

Endothelial cells that line the blood vessels are damaged, resulting in blood leaking through the walls, resulting in hemorrhages. No organs appear to be exempt from hemorrhage

EHD - Virus isolation (cell culture, Intravenous injection in embryonated chicken eggs/ECE, inoculation of susceptible sheep or deer, serological monitoring

_______________ ___-______ is used for the discrimination between EHDV and BTV.

Multiplex real-time RT-PCRs

Palyam Virus is a species of _______ infecting ?

ORBIVIRUS, cattle and sheep.

Palyam virus is transmitted by _______ mosquitoes and _____ (CULICOIDES) that results in _________ and _____ diseases, as well as? No ________.

culicine, gnats, Reproductive, CNS, abortion, congenital abnormalities, hydraencephalopathy., vaccine

What virus is pictured here?

Rotaviruses

Rota means ______ shape, worldwide distribution

wheels

Rotavirus infects ________ _______ cells at the ____ of the intestinal _____ with resulting malabsorption, maldigestion, and diarrhea

mature adsorptive, tips, villi

Rotaviruses are divided in different serogroups (or species) based on: _____

VP6

Rotavirus serotypes within serogroup-A are recognized by: _____

VP7

In the case of NEONATAL Rotavirus infection, ______ immunity is more important than circulating ______.

Local, antibody (IgA = more superior in protection than IgG because it is circulating in blood/serum while A is in mucosal membranes in nasal, GI tract).

Rotavirus can be _______ and rapidly detected in _____ by the ELISA

sensitively, stools

The severity of rotavirus infection is determined by: -The _______ of the infecting viral strain -The _______ of virus ingested -The level of _______-derived immunity - ____ of the animal at the time of exposure and _________ factors

virulence, amount, maternally, Age, management

Describe the mechanism of Rotavirus

* Damage of the villi: shortened and covered with immature, less differentiated epithelia that migrate from the crypts * NSP4: viral _________ & rotavirus stimulates ________: both activates _______ pathways: - Increase ____cellular ___ concentration - __________ secretion from the crypts - _____________ diarrhea - _______ loss of ______ and _________

enterotoxin, neurotransmitters, secretory, intra, Ca, Chloride, Secretory, Rapid, water, electrolytes

What can be seen here?

Retrovirus attaching to a lymphocyte

Replication of Rotaviruses

When animal has diarrhea and loss of fluids, there is reduced ?

Rotaviruses are difficult to isolate in tissue culture from clinical samples. Addition of low concentrations of _______ to growth medium facilitates viral ______ and improves viral _______.

trypsin, uncoating, replication

Diagnosis of Rotaviruses

* Proper sampling * Detection of virus particles : EM * Detection of virus Ag: IFT * Detection of viral RNA: RT-PCR

Rotavirus

Animal rotaviruses can, in rare cases can be ________.

zoonotic

Rotavirus vaccines * A live, oral, __________, human-bovine ________ vaccine * Administered at 2, 4, and 6 months of age * RotaTeqTM * RotarixTm

pentavalent, reassortant

Avian Reovirus (ARV)-syndromes causes ?

Viral arthritis/tenosynovitis Fibrinous tenosynovitis Stunting syndrome in broilers (outside of Reovirus, other bacteria contributing here). Helicopter disease

* Viral arthritis/tenosynovitis * lameness and swellings affecting primarily tarsometatarsal joints and the feet * Many infected birds are in good general condition, but some are lethargic and exhausted

Fibrinous tenosynovitis inflammation of the tendon progresses to a chronic type lesion characterized by tissue fibrosis in the affected area

* Helicopter disease * The growing primary wing feathers, abnormally big for chickens with retarded growth, protrude at various angles.

What condition is this animal suffering from? Causative agent?

Helicopter disease Avian reovirus

Avian Reovirus-syndromes-Diagnosis * History, clinical signs, PM lesions * Laboratory diagnosis * Sampling (select the affected tissues ) * Isolation of the viruses by cell culture and ECE * Detection of the virus by EM * Detection of the virus nucleic acid by PCR * Detection of the viral antigens and antibodies by ELISA, NT etc

Arthritis lesion: pitting of the articular _______ over the distal _______ condoyle in the broilers. What virus causes this pathology?

cartilage, tibiotarsal, Avian reovirus

Equine Encephalosis (EE) is an ___________-borne ______ , ______-contagious disease of _______.

arthropod, febrile, non, equines

Name the serotypes of EE?

Has several serotypes (EEV1-EEV7)

_______ and ______ can act as maintenance host of EE virus, making the elimination of the virus difficult.

Zebra, elephants

EE virus A novel real time Polymerase Chain Reaction (PCR) assay has also been developed for the detection of EEV by targeting the gene ?

Viral Protein (VP)-7

Members of the genus Coltivirus?

Colorado Tick fever virus Tick fever/Saddle-back fever

Colorado tick fever virus is a ______ disease that occurs in ____-altitude ____ habitats * [1000 – 3000 metres] – in the ____ Mountain region of USA

zoonotic, high, forest, Rocky

Colorado tick fever virus is Transmitted by?

wood tick – Dermacentor andersoni

Colorado tick fever virus ________ ticks transmit the virus mainly to _____ mammals such as?

Nymphal, small, squirrels, rats, and other rodents

This animal is suffering from what virus? What genus does this virus belong to? What species are typically affected? Results in?

Grass Crap Reovirus (GCRV) Genus: AQUAREOVIRUS Affects Fish and shellfish results in : Focal hepatic necrosis, hemorrhagic lesions in many tissues

Members of the family Birnaviridae Genome: ____ _____-stranded RNA segments (2.9 to 3.6 kbp) with the RNA-dependent RNa polymeraase covalently linked to the __'-end of the genomic positive-strand.

Two, double, 4

What virion is pictured below?

Family: Birnaviridae

What virion is pictured below?

Family: birnaviridae

2 DS RNA

Name the three genuses that fall under the family Birnaviridae

Name the viral species that fall under Aquabirnavirus

Infectious pancreatic necrosis virus (IPNV)

Name the viral species that fall under Avibirnavirus

Infectious bursal disease virus (IBDV)

Name the viral species that fall under Entomobirnavirus

Drosophila X Virus (DXV)

The family Birnaviridae genome is ?

dsRNA

Name the hosts that carry the viruses under the family Birnaviridae

Vertebrates, invertebrates

Under the genus Birnaviridae, the genus Blosnavirus has one virus named?

Blotched snakehead virus

What Virus family possesses this genome? Segment A possesses? Segment B possesses?

Birnaviridae Segment B: ORF3 includes Viral protein 1. Segment A: ORF1 includes VP5, ORF2 includes VP2,3,4 (ORF2 is important for vaccine development?)

_______ circularize segment A and B by binding their ends.

VPg

What virus has this genome? What is the family this virus falls under?

Infectious bursal disease virus Birnaviridae

What virus has this genome? What is the family this virus falls under?

Infectious pancreatic necrosis virus Birnaviridae

Birnaviridae

IBDV Replication strategy

Avibirnavirus -Infectious Bursal Disease virus (IBDV) (_________ disease) * An acute, ______ __________ disease of chickens: significant economic losses. Additionally, this disease results in: 1. Mortality 2. Reduced performance and 3. _______________: increased susceptibility to other diseases 4. Tropism: the ______ of ______, an important organ in the young chickens developing immune system * The second most important poultry disease after Newcastle disease * Transmission: infected chickens shed the virus in their feces *** Other chickens in the house become infected by ingesting the virus from contaminated feed, water and poultry house (oral rout) ***** Mechanical transmission among the farms by people, equipment and vehicles * Occurrence: worldwide

Gumboro, highly contagious, Immunosuppression, bursa, Fabricius

IBDV-Resistance to physical and chemical agents **** Extremely ______ virus * Tolerate a wide pH range (***pH (extremely acidic ___-__ extremely _______) * Heat stable (still viable after 30 minutes at 60°C) * High level of resistance to most commonly used disinfectants * Survives in the poultry house environment for extended periods of time

stable, 2-12, alkaline

IBDV-Pathogenesis * Initial replication occurs in the intestinal tract within hours of ingestion of the virus. * The virus then disseminates to numerous lymphoid tissues including the bursa of Fabricius, thymus, spleen and tonsils. * Gross lesions include dehydration, hemorrhage in the pectoral and leg muscles, enlargement of BF with edema and hyperemia.

IBDV pathogenesis pathway

Classification of IBDV strains - Serotype 1

**Classification of IBDV Strains - Serotype 2

Benign serotype

IBDV Classical or standard strain: 10-50% mortality Variant virus: no mortality Very virulent virus: 50-100% mortality

What viral disease is this animal suffering from?

IBDV

IBDV Clinical signs * The most susceptible chickens are of age 3 – 6 weeks. * Soiled vent feathers * ** _________ * ** __________ *** _________ feathers * Anorexia * Trembling * Sever weakness * Dehydration and eventually death

Diarrhea, Depression, Ruffled

IBDV Kidney embedded in the vertebral column of birds but in this scenario it is very chord like

IBDV Various stages of hemorrhagic and severe hemorrhagic IBDV infection in bursa

IBDV Areas of necrosis on right. Bursa --> hemorrhage

Diagnosis of IBDV * Clinical sings & PM lesions are highly suggestive * Laboratory diagnosis 1.Proper sampling 2.Virus isolation -ECE inoculation -Tissue culture 3.Detection of viral Ag &Ab -ELISA -FAT 4.Detection of viral RNA -RT-PCR * Differential diagnosis

IBDV-Control * Control may be facilitated by proper sanitation practices * Vaccination programs are widely used to control IBVD ****** Both _________ and ______ vaccines are available ***** Broilers: in ___ vaccine at __ days of incubation: live attenuated virus: produce an _______ immune response earlier in chicken life **** VP2 recombinant vaccine: produce a __________ immune response * The complexity of poultry raising programs: no single vaccination program for all the production systems and types of chickens

attenuated, killed, ovo, 18, active, protective

Virulence based classification of IBDV strains

Infectious Pancreatic Necrosis Virus of Fish (IPNV) * _____ contagious and lethal of ______ & _______ and young Atlantic _____ fish * Visceral organs (heart, liver, kidney, and spleen) ____ * ________ in intestine and ceca * Small to large foci of necrosis of ____ cells of pancreas

Highly, salmonid, rainbow, salmon, pale, Hemorrhage, acinar

IPNV

What viral disease is this animal suffering from? What are the clinical signs?

IPNV A- Abdominal distention pale gills of trout B- Hemorrhage in the intestine C- Normal pancreases D- Necrosis of pancreas E- Gradient purified virus -Pale enlarged liver and spleen **- Frantic corkscrew swimming followed by periods of rest

How do you diagnose IPNV? Diagnosis Signs, PM, Pathology **Virus ________ on standard fish cell lines *** ______is the best organ of choice for virus isolation *Detection of viral Ag: IFA, SNT, ELISA *Detection of viral RNA: RT-PCR

Diagnosis *Signs, PM, Pathology ***Virus isolation on standard fish cell lines ***Kidney is the best organ of choice for virus isolation *Detection of viral Ag: IFA, SNT, ELISA *Detection of viral RNA: RT-PCR

* ‘Picobirnavirus’ derives from the prefix ‘pico’ (latin for ‘_____’): small virion size * Prefix ‘bi’ (latin for ‘____’) * ‘RNA’ to indicate the nature of the viral genome

small, two

The genome of the family Picobirnaviridae?

What viral family is pictured below?

Picobirnaviridae

PBV detection in the environmental and food samples Importance of environmental samples for early monitoring of viral diseases

PBV detection in various hosts and environment samples

15,20,25,25,35

Reovirdae Birnaviridae Pibicornavirdae Flashcards

(146 cards)