Week 10 - Nidovirales Coronaviridae Arterivirdae Ronivirdae Flashcards
Nido means?
Nest
Name the viruses that belong to the order Nidovirales.
1- Coronaviridae
2- Arterivirdae
3. Roniviridae
- Name the families that fall under the Order Nidovirales.
- What viruses are within the genus Okavirus?
Mentioned families
Okavirus –> GAV, YHV (prawns, shrimp)
Arterivirus
Coronavirus ; now 4 groups of coronaviruses
Different virus families.
Know each of these pictures.
Just shows diversity and complexity of coronaviruses
Coronaviridae – General Properties
1. Corona: from Latin corona, “_______”; refers to the characteristic appearance of surface __________ that create an image reminiscent of the ______ corona.
2. Enveloped or non-enveloped?, ____-_____ nm
3. **__________-strand RNA (27-32 kb),
- ____________ replication
- __________ into ER and Golgi
- Notoriously difficult to propagate in ________
- High frequency of ___________**
Coronaviridae – General Properties
Corona: from Latin corona, “halo”; refers to the
characteristic appearance of surface projections that
create an image reminiscent of the solar corona.
Enveloped, 120-160 nm
Positive-strand RNA (27-32 kb), Cytoplasmic replication
Budding into ER and Golgi
Notoriously difficult to propagate in culture
High frequency of recombination
What virus family is pictured below?
Coronaviridae
Important
Label accordingly
Label accordingly
Causes of variations among CoVs/emergence of new viruses/strains of viruses
* ______ and _____ are major reservoirs for CoVs
Some coronaviruses have ability to
-Change tissue _____
-Pass species ____
-adapt to new ecological _____
Causes of CoV variations
- Accumulation of _____ mutations
- Poor proofreading capability of ______ gene (virus in replication cycle makes errors, which convey into mutations –> development of ____ strains).
- Possibility of ________*
Bats, birds, tropism, barriers, niches, point, RdRP, new, recombination
Most-up-to-date classification of Coronaviridae
* ICTV: coronavirus group meeting Oct 2020
* Coronaviridae: 2 subfamilies, 5 genera, 26 subgenera and 46 species
Within the family Coronviridaue, name the Subfamily, Genus, and the Subgenus
Letovirinae, alphaletovirus, milecovirus
- How many groups of Coronaviruses are there?
- Name the viruses belonging to each group.
- What do the letters on the side mean?
- Gamma corona virus is specifically for which species?
- 4
- P = pigs, F = feline, C = canine, etc.
- Birds
Just FYI
6/7 human coronaviruses, some of which have zoonotic potential
VERY IMPORTANT
1.What is the length of the coronavirus genome?
2.2/3 of genome is made up of?
3.S =? HE = ?
4.Subgenomic mRNA for S, E, HE; These subgenomes make the nest.
- What is the length of the coronavirus genome? 27-31 kb, from 5’ to 3’
- unstructeed protein aka gene 1. Divided into two parts: 1a and 1b. There is overlapping between 1a and b called ribosomal frame shifting. Overlpaping frame synthesizes proteins, frame shifts back and moves into another frame in order to synthesis.
- S = ?, HE = aquired to come from influenza virus type B; Virus with HE gene is bigger than virus without it.
Gamma is shortest one: 27.6
Beta is biggest one: 31.3 kb
HE gene is 3-4 kb
Do not memorize this
Describe the pathogenesis of Coronaviruses.
Outside the host = inactive
Activated inside the host by host cell proteases (furin)
Respiraotry tract has proteases that cleave spike gkycoprotein, activating the virus.
Drugs that inhibit furin prevent infection from occurring.
What is the receptor for SARs-COV?
What is the receptor for MERs-COV?
ACE2
DPP4
Virus by negative pressure –> injected through hole into host cell.
Coronavirus life cycle
MERS-CoV life cycle
Human coronaviruses
* First described in the 1960s from the nasal cavities of patients common cold named
human coronavirus 229E and human coronavirus OC43.
* Currently ___ Human coronaviruses are currently known
1- HCoV-229E
2- HCoV-OC43
3- SARS-CoV
4- HCoV-NL-63
5-HCoV-HKU1
**6- MERS-CoV
7-HCoV-44 (enteric)
**8- SARS-CoV-2
8
Evolution of Human Coronaviruses in context of One Health
concept
SARS coronavirus- SARS-CoV
* Year _______: Previously unknown coronavirus was isolated from patients
* 8,098 SARS cases worldwide during the 2003 outbreak, resulting in 774
deaths
* April 2003, following the outbreak of SARS in Asia & secondary
* cases elsewhere in the world
* Complete genome sequence April, 2003, : MSFC, UBC, Canada
**Intermediate host? ** ______ Delicacy; Minimize human exposure.
2002, Mongoose
What is pictured below? How does this relate to coronaviruses?
SARS-CoV-Intermediate Host-Civet Cat
Nocturnal animal related to Mongoose Delicacy
Middle East Respiratory Syndrome Coronavirus (MERS-CoV)
-A novel _________ (nCoV) first reported on 24
September 2012
-Belongs to the genus Betacoronavirus, as does SARS-CoV
- Symptoms of MERS
- Severe _______ _________ illness with symptoms of
-Fever, cough, and shortness of breath
**-About half of them died
**-Some people were reported as having a mild respiratory
illness
-MERS-CoV spread from person to person
coronavirus, acute respiratory
Middle East Respiratory Syndrome Coronavirus (MERS-CoV)
Global distribution of MERS-CoV cases
Classification of MERS-CoV
Renamed novel to proper name
BatMERS-CoV Evolution Theories????
Bat on palm tree –> defecate –> fruit contamined –> human consumption
Camels (1 and 2 hump) are reservoirs.
MERS-CoV-like virus is widely distributed.
What does this mean?
Can camel viruses infect humans?
Camels in parts of Africa and middle east were studied
MERS-CoV-Transmission- updated Hypothesis
?
Roles of Camels in the transmission of MERS-CoV
* _______ Camels are the only species of animals seroconvert to MERS-CoV
* Camels under one year old have ____
seroprevalence (72%)
* Older camels have ____ seroprevalence (95%)
* Some camels have high titre to MERS-CoV in absence of any BCoV reactivity
* Animals could be infected with different to BCoV and my be identical to MERSCoV
Dromedary, lower, high
SARS-CoV-2 replication cycle
Closely similar to Sars COV-1
Pathophysiology of SARS-CoV-2
Hiding in different organs; urogenital tract, vessels, etc.
SARS-CoV-2 variants
WHO- SARS-CoV-2 variants labelling and classification
SARS-CoV-2 and DIVA concept
Differentiate infected and vaccinated animals = DIVA
DIVA does not distinguish between natural infection or vaccination
Strategies for
treatment of
Coronaviruses
Vaccines target weak points of virus.
Therapeutic trails for SARS-CoV-2
Different approaches to stop replication cycle of virus to control infection.
Using polymerase inibitor
Bovine Coronavirus (BCoV) –> effects ________ species
Well known in ____ and ____ production
Tropism: Epithelial cells of ___ and _______ tract
Persistent infections
Increased shedding in ____ and at ______
BCoV clinical syndromes (3)
?
bovine, milk, meat, gut, respiratory, winter, calving
- Calf diarrhea (CD)
-Winter dysentery (WD)
-Bovine respiratory diseases complex (BRDC)
Dehydration (rehydrate animal)
Diarrhea
Vomiting
Four Clinical Syndromes associated with BCoV Infections
- Enteric infections
- Water dysentery
- Respiratory infections
- Bovine respiratory disease
(1) **Enteric Infections **
Calf _______ (CD), dehydration
Intestinal ____ atrophy
- Effects calfs age ranging from ____ to __ wks of age
diarrhea, villous, Birth, 4
(2) Winter dysentery (WD) ________ diarrhea + upper ___ months to ____, _________ infection
Intestinal ______ atrophy
Bloody, 6, adult, respiratory, villous
(3) Respiratory Infections (BRDC)
Calf respiratory disease __ wks to ___ months
2, 6
(4) Bovine respiratory disease __-__-month-old, complex (shipping fever feedlot cattle
Cough, nasolacrimal discharge, pneumonia
6-9
All BCoV isolates belong to 1 serotype (2 subtypes) and are pneumo/enteric –> _____________
pneumoenteritis
Only point mutations occur in the ___ gene of BCoV-___ vs BCoV-__ strains
Variation in strains based on ___ nucleotide in full length genome, changing ________, _________ of virus, etc.
S, E , R, one, tropism, behavior
What is this an image of?
Yellow Diarrhea
Characteristic for bovine coronavirus
Virus irritating mucous membrane –> destroys villi, shortens them, decreases surface area –> diarrhea (shooting out)
What is this an image of?
Winter dysentery
Sudden onset of diarrhea
with fresh blood in adults
Bovine coronavirus kinetics
Incubation period: time from infection until onset of clinical signs
Virus peaks after several days, then drops –> animal should recover, unless immunocompromised/coinfection with other pathogen.
Infectious bronchitis virus (IBV)
* _____ known coronavirus
* Discovered in 1930 in USA
* Primary site of infection upper respiratory tract/ reproductive
tract of _______ –> ______ and ______
–>** Virus detection**
1. Viremia
2. Nasal secretions
3. Feces and Urine
Disease is most severe in _____ _____
–> Other organs infected (sites of IBV persistence with periodic nasal shedding)
1. ______ (Nephropathogenic strains)
2. Tissue _____ of one IBV strain altered from respiratory to kidney tissues by serial passage in the cloaca
3. Oviducts (_____?)
4. ________
First, chicken, Trachea, Bronchi, baby, chicks, Kidneys, tropism, eggs, Intestine
Infectious bronchitis Virus (IBV)
Sensitivity: 56°C 15 min at room temperature 2-3 days
__________ detergents destroy
Pathology:
-Acute catarrhal tracheitis, - _______
-Sinusitis, air sacculitis - Local ________
Nephritis, -_______ = inflammation of oviduct (____ can not pass through –> issue in ___ production !)
**Stones in the ______ (_____) and _____ = another sign of IBV.
** Economic impacts of IBV infection in chicken:
- Poor _____ performance and ______ due to reparatory infection
- Losses in the ___ production and low ______ ____ production
- Loss associated with _____ damage in broilers and breeder chickens
common, Bronchitis, pneumonia, Salpingitis, eggs, egg, kidney, ureates, ureter, growth, mortality, egg, quality, egg, renal
Celiac acid? Newcastle?
IBV-induced clinical
syndromes in chickens
skipped
Macroscopic lesions
Respiratory tract
Mucus and redness (no hemorrhage) in trachea, froth in air
sacs in older chickens.
In young chicks a yellow cheesy plug at the tracheal
bifurcation is indicative of IB infection.
Reproductive tract
Fluid yolk material may be found in the abdominal
Abnormal ovary having the misshapen follicles
Egg- Outer surface - Ridges or concretions
Watery albumin
Nephrotic form
Swollen, pale kidneys, with tubules and ureters distended
with urates
In layers, urolithiasis is associated with certain
dietary factors