Virology- overview Flashcards
Morphology of Viruses
Morphology of Viruses
Enveloped vs. naked viruses
- enveloped= lipid layer enclosing nucleocapsid
- naked= just nucleocapsid
Different shapes of viruses
![](https://s3.amazonaws.com/brainscape-prod/system/cm/159/087/189/a_image_thumb.png?1442428266)
Structure of Viruses
Viruses contain nucleic acid genome (DNA or RNA) surrounded by a protein coat (capsid) and, in some cases, other layers of material, such as a lipid envelope (a bubble of fat).
- Capsid- protein shell that encases the nucleic acis/genome
- Nucleocapsid = Capsid + Nucleic acid
- Lipid envelope=outside of nucleocapsid
- Glycoproteins= on surface of envelope
![](https://s3.amazonaws.com/brainscape-prod/system/cm/159/087/190/a_image_thumb.png?1442427563)
Chemical composition of Viruses
Chemical composition of Viruses
![](https://s3.amazonaws.com/brainscape-prod/system/cm/159/087/191/a_image_thumb.png?1442428312)
Replication of Viruses (5)
- ) Attachment
- )Penetration
- )Uncoating- removal of protein coat (release genetic material)
- )Synth of viral nucleic acid (genetic material of virus hijacks synth)
- )Assembly and Maturation-viral particles assembled and released
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Epidemiology of viral infections
(7 modes of transmission)
Transmition
- Direct-Contact Transmission: Direct physical contact with infected/Susceptible Host
- Indirect-Contact Transmission:Contaminated inanimate objects (Fomites)
- Common-Vehicle Transmission: Fecal contamination of Water or Food and Virus contamination of Meat or Meat products
- Airborne Transmission
- Vector (Arthropod)-Borne Transmission
- Zoonotic Transmission
- Vertical Transmission- embryonic
![](https://s3.amazonaws.com/brainscape-prod/system/cm/159/087/193/a_image_thumb.png?1442428964)
Diagnosis of viral infections (7)
Diagnosis of viral infections
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- ) Clinical signs- visible in physical exam ex.bluetongue virus in sheep
- ) Necropsy- post mortem investigation (internal signs)
- ) Histopathology- looking at tissue
- ) isolation and cultivation- cultures
- )Electron Microscopy- can see shape of virus
- ) Serology- detection of viral antigen or host antibody (ELISA)
- )PCR- process that amplifies nucleic material of virus so it is ealily detected/identified
Treatment of viral infections (3)
Treatment of viruses
- Antiviral drugs-Interfere with the ability of a virus to infiltrate a target cell or target different stages of replication/Synthesis of components required for replication of the Virus.
- Immune stimulation-Interferons, class of proteins that has antiviral effects and modulate functions of the immune system.
- Synthesize antibodies/administration of natural antibodies
Prevention of viral infections (4)
Prevention of viral infections
- Vaccination
- Proper Hygiene
- disinfectants
- Eliminating Arthropod Vectors
- using biological or chemical methods
- Quarantine & Culling
- separate/restrict movement of animals
Zoonotic virus
Zoonotic viruses can be transmitted between animals and humans
Virus Facts
Virus facts
“A Virus is a Piece of Bad News Wrapped up in a Protein”
- non-living entities
- no cellular organelles
- cannot make energy for itself
- obligate intracellular parasite (depends on other cells to survive)
- cannot multiply by division (use pieces and parts of host cell)
Effect of viral replication on host cells
Effect of viral replication on host cells
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Cell death
fusion of cells
transformation to malignant cell
none
Types of Vaccines
Types of Vaccines
- Live-Attenuated Virus Vaccines:
- produced from other viruses
- Non-Replicating Virus Vaccines
- made from inactivated virons or viral proteins
- Vaccines Produced by Recombinant DNA and Related Technologies
- made from viral proteins or genetic matrial
in an enveloped virus, the lipid bilayer is kept under the capsid.
(true/false)
false
lipid bilayer outside- helps facilitate entry into new cells
capsid
genetic material inside
Step after uncoating in viral replication…?
synthesis of viral DNA
Viruses can be cultured the same way as bacteria?
(true/false)
False
viruses have to have a living cell to replicate