RNA viruses overview Flashcards
RNA strands
All RNA viruses except Reoviridae are ssRNA
- Memory aid:*
- All are ssRNA (like our mRNA), except “_re_peato-virus” (_re_ovirus) is dsRNA
Site of RNA virus replication
All replicate in the cytoplasm (except influenza virus and retroviruses which replication in the nucleus)
Memory aid:
- DNA virus – Dun sa nucleus
- RNA virus – Ruwar ng nucleus
- Sa nucleus RIN – 2 RNA viruses (Retro and Influenza in Nucleus)
Negative-stranded viruses
- Arenaviruses
- Bunyaviruses
- Paramyxoviruses
- Orthomyxoviruses
- Filoviruses
- Rhabdoviruses
Memory aid:
- _A_lways _B_ring _P_olymerase _o_r _F_ail _R_eplication
- BOAR + PF (Para Filo)
Property of negative-stranded viruses
- Virion brings its own RNA-dependent RNA polymerase
- Must transcribe negative strand to positive
- Not readily infectious
SPIN mnemonic
- SPIN Ca-He-Pi
- SS
- Positive strand
- Icosahedral
- Naked
- Calicivirus
- Hepevirus
- Picornavirus
SPIE mnemonic
- SPIE To-Fla-Re
- SS
- Positive
- Icosahedral
- Enveloped
- Togavirus
- Flavivirus
- Retrovirus
SPHeE mnemonic
- SPHeE
- SS
- Positive
- Helical
- Enveloped
- Coronavirus
SNHeE mnemonic
- SNHeE BOAR + PF
- SS
- Negative
- Helical
- Enveloped
- Bunyavirus
- Orthomyxovirus
- Arenavirus
- Rhabdovirus
- Paramyxovirus
- Filovirus
Capsid symmetry of delta virus
Either helical or unknown
All RNA viruses contain single-stranded RNA, except for which family?
Reoviridae
- Remember:*
- All are single-strand RNA except “repeatovirus” [reovirus] is double-stranded RNA
Orthomyxoviruses
- Strand
- Polarity
- Envelope
- Symmetry
- Shape
- Example
- Strand
- SS
- Polarity
- Negative sense
- Envelope
- Yes
- Symmetry
- Helical
- Shape
- Linear
- Example
- Influenza
Memory aid:
-
SNHeE – BOAR + PF
- SS
- Negative
- Helical
-
Enveloped
- Bunyavirus
- Orthomyxovirus
- Arenavirus
- Rhabdovirus
- Paramyxovirus
- Filovirus
Paramyxoviruses
- Strand
- Polarity
- Envelope
- Structure
- Examples and disease caused
- Strand
- SS
- Polarity
- Negative sense
- Envelope
- Yes
- Structure
- Helical
- Examples and disease caused
- Parainfluenza – croup
- RSV – bronchiolitis in babies
- Measles, Mumps
Memory aid:
-
SNHeE – BOAR + PF
- SS
- Negative
- Helical
-
Enveloped
- Bunyavirus
- Orthomyxovirus
- Arenavirus
- Rhabdovirus
- Paramyxovirus
- Filovirus
Paramyxovirus protein component and action
Surface F (fusion) protein, which causes respiratory epithelial cells to fuse and form multinucleated cells
Presence of hemagglutinin, neuraminidase and fusion protein in each species of paramyxovirus
- Parainfluenza
- F + N + H
- RSV
- F only
- Measles
- F + M only
- Mumps
- F + N + H
Togaviruses
- Strand
- Polarity
- Envelope
- Structure
- Shape
- Example (s)
- Strand
- SS
- Polarity
- Positive sense
- Envelope
- Yes
- Structure
- Icosahedral
- Shape
- Liner
- Example (s)
- Rubella virus
- Western and Eastern equine encephalitis virus
- Chikungunya virus
Memory aid:
-
SPIE To-Fla-Re
- SS
- Positive
- Icosahedral
-
Enveloped
- Togavirus
- Flavivirus
- Retrovirus
- Chik Rubi on a Horse has toga!
Rhabdoviruses
- Strand
- Polarity
- Envelope
- Symmetry
- Structure
- Strand
- SS
- Polarity
- Negative sense
- Envelope
- Yes
- Symmetry
- Helical
- Structure
- Bullet-shaped
Memory aid:
-
SNHeE BOAR + PF
- SS
- Negative
- Helical
-
Enveloped
- Bunyavirus
- Orthomyxovirus
- Arenavirus
- Rhabdovirus
- Paramyxovirus
- Filovirus
Human T-lymphotropic virus
- Strand
- Polarity
- Envelope
- Structure
- Shape
- Strand
- SS
- Polarity
- Positive sense
- Envelope
- Yes
- Structure
- Icosahedral
- Shape
- Linear
- Note:*
- It is a retrovirus
- Memory aid:*
-
SPIE To-Fla-Re
- SS
- Positive
- Icosahedral
-
Enveloped
- Togavirus
- Flavivirus
- Retrovirus
Human T-cell Lymphotropic Virus (HTLV) disease caused and histopath finding
- Disease caused
- Adult T-cell leukemia
- Histopath finding
- Malignant T cells with flower-shaped nucleus
HIV
- Strand
- Polarity
- Envelope
- Structure
- Shape
- Strand
- SS – s copies (diploid)
- Polarity
- Positive sense
- Envelope
- Yes
- Structure
- Icosahedral
- Shape
- Linear
- Note:*
- It is a retrovirus
- Memory aid:*
-
SPIE To-Fla-Re
- SS
- Positive
- Icosahedral
-
Enveloped
- Togavirus
- Flavivirus
- Retrovirus
Four retroviruses known to cause human disease
- HTLV I and HTLV II
- Transforming retroviruses
- HIV 1 and HIV 2
- Cytopathic effects
What are the enteroviruses?
- All of the picornaviruses except rhinovirus
- Poliovirus
- Echovirus
- Coxsackievirus
- HAV
Picornaviruses
- Strand
- Sense
- Envelope
- Symmetry
- Shape
- Example (s)
- Strand
- SS
- Sense
- Positive sense
- Envelope
- No
- Symmetry
- Icosahedral
- Shape
- Linear
- Example (s)
- Poliovirus
- Echovirus
- Rhinovirus
- Coxsackievirus
- HAV
Memory aid:
-
SPIN Ca-He-Pi
- SS
- Positive
- Icosahedral
-
Naked
- Calicivirus
- Hepevirus
- Picornavirus
All picornaviruses are enteroviruses except ____ becauses it is ____
- Rhinovirus
- Acid labile – destroyed by stomach acid; therefore, does not infect the GI tract (unlike the other picornaviruses)
HAV
- Otherwise known as
- Most frequently infected population
- Most important test
- Disease caused
- Otherwise known as
- Enterovirus 72
- Most frequently infected population
- Children
- Most important test
- Anti-HAV IgM
- Disease caused
- Hepatitis A
Reovirus
- Strand
- Envelope
- Symmetry
- Shape
- Examples
- Strand
- DS
- Envelope
- No
- Symmetry
- Icosahedral
- Shape
- Linear
- Examples
- Coltivirus
- Rotavirus
Coronavirus
- Strand
- Polarity
- Envelope
- Structure
- Shape
- Strand
- SS
- Polarity
- Positive sense
- Envelope
- Yes
- Structure
- Helical
- Shape
- Linear
Memory aid:
-
Corona SPHeE
- Single strand
- Positive sense
- Helical
- Enveloped
Coronavirus
- Why is it so named?
- Reservoir and intermediate host
- MOT
- Disease (s) caused
- Why is it so named?
- Prominent club-shaped spikes form a “corona”
- Reservoir and intermediate host
- Reservoir: horseshoe bat
- Intermediate host: civet cat
- MOT
- Respiratory droplet transmission
- Disease (s) caused
- Common cold
- SARS
- MERS
Calicivirus
- Strand
- Polarity
- Envelope
- Symmetry
- Shape
- Example
- Strand
- SS
- Polarity
- Positive sense
- Envelope
- No
- Symmetry
- Icosahedral
- Shape
- Linear
- Example
- Norovirus (Norwalk) virus
Norovirus (Norwalk virus)
- Viral family
- Disease (s) caused
- MOT
- Incubation period
- Manifestations
- Viral family
- Calicivirus
- Disease (s) caused
- Viral gastroenteritis
- MOT
- Fecal-oral
- Incubation period
- 24 – 48 hours
- Manifestations
- Sudden onset of vomiting and diarrhea accompanied by fever and abdominal cramping
The structure of the genome of reovirus is unique among RNA viruses in what respect?
The structure of the genome of reovirus is unique among RNA viruses in what respect?
Flaviviruses
- Strand
- Polarity
- Envelope
- Symmetry
- Shape
- Strand
- SS
- Polarity
- Positive sense
- Envelope
- Yes
- Symmetry
- Icosahedral
- Shape
- Linear
Memory aid:
-
SPIE To-Fla-Re
- SS
- Positive
- Icosahedral
-
Enveloped
- Togavirus
- Flavivirus
- Retrovirus
Diseases caused by Flaviviruses
- West Nile virus (meningoencephalitis)
- Japanese encephalitis
- Hepatitis C Virus
- St. Louis encephalitis
- Yellow fever
- Dengue
- Zika virus
- Memory aid:*
- West Nile JC-SYDZ
Filoviruses
- Strand
- Polarity
- Envelope
- Structure
- Shape
- Disease (s) caused
- Strand
- SS
- Polarity
- Negative sense
- Envelope
- Yes
- Structure
- Helical
- Shape
- Linear – thread-like
- Disease (s) caused
- Ebola/Marburg hemorrhagic fever
Memory aid:
-
BOAR + PF SNHeE
- SS
- Negative sense
- Helical
-
Enveloped
- Bunyavirus
- Orthomyxovirus
- Arenavirus
- Rhabdovirus
- Paramyxovirus
- Filovirus
Bunyavirus
- Strand
- Polarity
- Envelope
- Structure
- Shape
- Disease (s) caused
- Strand
- SS
- Polarity
- Negative sense
- Envelope
- Yes
- Structure
- Helical
- Shape
- Linear – thread-like
- Disease (s) caused
- California encephalitis
- Sandfly/Rift Valley fevers
- Crimean-Congo hemorrhagic fever
- Hantavirus – hemorrhagic fever, pneumonia
Memory aid:
-
BOAR + PF SNHeE
- SS
- Negative sense
- Helical
-
Enveloped
- Bunyavirus
- Orthomyxovirus
- Arenavirus
- Rhabdovirus
- Paramyxovirus
- Filovirus
Arenavirus
- Strand
- Polarity
- Envelope
- Structure
- Shape
- Disease (s) caused
- Strand
- SS
- Polarity
- Negative sense
- Envelope
- Yes
- Structure
- Helical
- Shape
- Linear – thread-like
- Disease (s) caused
- LCMV – lymphocytic choriomeningitis virus
- Lassa fever encephalitis – spread by rodents
Memory aid:
-
BOAR + PF SNHeE
- SS
- Negative sense
- Helical
-
Enveloped
- Bunyavirus
- Orthomyxovirus
- Arenavirus
- Rhabdovirus
- Paramyxovirus
- Filovirus
Name six viral families that are single-strand, positive-sense, linear RNA viruses with icosahedral capsids
- Picornavirus
- Hepevirus
- Calicivirus
- Flavivirus
- Togavirus
- Retrovirus
Memory aid:
- SPIN Ca-He-Pi
- SPIE To-Fla-Re
All negative-sense RNA viruses have what type of capsid?
Helical
- Memory aid:*
- BOAR + PF S_NHe_E
Which clinically significant virus has a segmented linear RNA?
Influenza (an orthomyxovirus)
What are the three viral families with circular RNA?
- Bunyaviruses
- Arenaviruses
- Deltavirus
- Memory aid:*
- BAD circle!
What is the only positive-sense RNA virus with a helical capsid?
Coronavirus
- Memory aid:*
- Coronavirus SPHeE
T/F. All helical viruses are enveloped
True
Memory aid:
- SP_HeE_
- SN_HeE_
What surface protein is common to all paramyxoviruses? What is its role?
Surface F (fusion) protein, which causes respiratory epithelial cells to fuse and form multinucleated cells
