Treatment, Prevention, Control of Viral Diseases Flashcards Preview

RUSVM Virology > Treatment, Prevention, Control of Viral Diseases > Flashcards

Flashcards in Treatment, Prevention, Control of Viral Diseases Deck (54)
1

How do Neuraminidase inhibitors prevent the release of virus?

Prevent release of virus and spread of virus because hemagglutinin of virus is still bound/attached to the sialic acid containing receptors on surface of infected cell.

2

Dry heat sterilization method

Hot air oven, at least two hours at 160c

3

Antimicrobial Chemotherapy

Treatment of infectious diseases by drugs (chemical compounds) that are inhibitory or lethal to the pathogenic microbe

4

Resistance to Amantadine occurs by

Changes in amino acids that line the M2 channel, changes prevent the drug from plugging the channel

5

Differentiating Infected from Vaccinated Animal -DIVA 

Vaccination with only live attenuated vaccines leads to a population of an antibody response that does not differ from the antibody response developed after natural infection.

 

Use of DIVA marker vaccines have a portion of the pathogen - less antigens than natrual strains

6

Antiviral Drugs

Class of medication used specifically for treating vial infections

7

Examples of Nucleoside Analog Reverse Transcriptase Inhibitors (NRTI's)

Zidovudine (ZDV) /  Azidothymidine (AZT)

Didanosine (ddI)

 

8

Targets for anti-retroviral therapy

Reverse transcriptase

Protease

Integrase

Fusion

9

Ways that live-attenuated virus vaccines are produced

Produced from naturally occuring attenuated viruses

Produced by attenuation of viruses by serial passage in cultured cells

Produced by attenuation of viruses by serial passage in heterologous host

Produced by attenuation of viruses by selection of cold-adapted mutants and reassortments

10

Types of non-replicating virus vaccines

Vaccines produced from inactivated whole virions

Vaccines produced from purifed native viral proteins

11

Internal Farm Biosecurity

Measures taken to combat spread of an infectious disease within the farm

12

Synthetic tricyclic amine of the adamantane family

Acts as both antiviral and anti-parkinson drug

 

Amantadine

13

Moist Heat Sterilization Method

Use of steam

Autoclave heated to 121c for at least 15 min at 15psi

14

T/F - Acyclovir is nontoxic to uninfected host cells

True

_________________________________________

Herpesvirus thymindine kinase and herpes virus DNA polymerase are not found in uninfected cells

15

Mechanism of ZDV / AZT

Resembles thymine deoxyribonucleotide triphosphate, reverse transcriptase cleaves two phosphates and inserts AZT monophosphate inot the cDNA that is being synthesized from viral RNA

16

Antisepsis

Application of a liquid antimicrobial chemical to skin or living tissue to inhibit or destroy microorganisms

17

Major membrane glycoproteins found on the surface of influenza virus

Neuraminidase (NA)

Hemagglutinin (HA)

18

Sterilization

Process that destroys or eliminates may or all pathogenic microorganisms, except bacterial spores on inanimate objects

19

Compared to antibiotics there are (more/less) antivirals available

Less

20

Mechanism of action of Amantadine

  1. Compound clog M2 channel and prevent it from pumping protons into the virion
  2. Viral RNAs remain bound to M1 and cannot enter nucleus

21

Non-Replicating Virus Vaccines

Vaccines produced from inactivated whole virions

22

Amantadine inhibits the replication of most strains of what virus

Influenza A viruses

23

Farm Biosecurity

Comprises all measures taken to minimize the risk of the introduction and spread of infectious agents

24

General farm biosecurity measures

Housing and management

All in All out housing system

Vermin and bird control

Purchasing policy

Visitor policy

25

Mechanism of Action of Acyclovir

  1. Acyclovir molecules → Acyclovir monophosphate by thymidine kinase enzyme
  2. Host cell adds two phosphates to acyclovir triphosphate.  Transported to the nucleus
  3. Two phosphates are cleaved by virus to form acyclovir monophosphate
  4. Acyclovir monophosphate incorporated into  growing DNA strand in place of a G base by Herpes Simplex DNA polymerase enzyme
  5. DNA stops growing - lacks attachment point necessary for insertion of additional nucleotides

26

Applies to animals/ persons who are known to be ill with contagious disease

Isolation

27

Major toxicities of AZT/ZDV

Anemia

Granulocytopenia

28

Applies to those who have been exposed to contagious disease

Quarantine

29

Antiviral Drugs

Drugs that 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

30

Live- Attenuated Virus Vaccine

Vaccines produced from naturally occurring attenuated viruses

31

Examples of Neuraminidase inhibitors

Oseltamivir (Tamiflu)

Laninamivir

Zanamivir

Peramivir

32

Acyclovir

Antiviral activity primarily restricted to herpesvirus

Administration as a prodrug, inactive form

Requires virus enzymes in infected host cell to convert itself into active form, which then interferes with virus replication

33

Mechanism for Resistance of Acyclovir

Absent production of viral thymidine kinase due to mutation in virus genome

Partial decrease in the production of viral thymidine kinase

Altered viral thymidine kinase substrate specificity that results in phosphorylation of thymidine 

Mutations in viral DNA polymerase that causes decreased binding of acyclovir-triphosphate to viral DNA polymerase

34

4 "w" of Immunization

Where

When

Who

Why

35

Features of a good vaccine

Safe to use

Effective against diverse strains of same pathogen

Few side effects

Give long lasting, appropriate protectio

Easy to administer

Inexpensive

Benefits outweigh the risk

36

Neuraminidase Inhibitors

Inhibit neuraminidase (NA) enzyme

_________________________

Synthesized by Influenza A and B viruses

37

Antivirals can act on what processes of viral replication

Receptor binding

Uncoating

Nucleic acid and protein synthesis

Assembly

Release

Modulate immune system

38

Family of nucleoside ananlog reverse transcriptase inhibititors (NRTIs)

Resembles thymine deoxyribonucelotide - triphosphate

ADV / AZT

39

Antiviral chemotherapeutic agents are not common in veterinary practice because

High cost of development

Restriction to a single virus and specific animal species

Difficulty in development of broadspectrum with low cytotoxicity

Absence of rapid diagnostic techniques

40

Amantadine inhibits the replication of influenza A viruses by what mechanism?

Blocking uncoating of the virus

41

Antibiotics

Types of medications that destroy or slow down the growth of the bacteria

42

External Farm Biosecurity

Measures taken to prevent an infectious disease from entering or leaving the farm

43

Disinfection

Process that eliminates many or all pathogenic microorganisms, except bacterial spores on inanimate objects

44

Viral infection stimulates what part of the immune system

Interferon

45

Antimycotics

Medications used to treat fungal diseases

46

Many agents that interfere virus replication are toxic to the cell because

Viruses are intimately dependent  on the metabolic pathways of their host cell for their replication

47

Oseltamivir - Tamiflu

Prodrug that after its metabolism in the liver, releases an active metabolite that inhibits neuraminidase

48

Sterilization Methods

Moist Heat

Dry Heat

Chemical methods

Radiation

Sterile Filtration

49

Decontamination

Process or treatment that renders a medical device, instrument or environemental surface safe to handle

50

Seconary mechanism of Amantadine to stop viral replication

pH change that result from M2 inhibition alter the conformation of hemagglutinin during its intracellular transport later in replication 

51

Interferons

Class of proteins that has antiviral effects and modulate functions of the immune system

52

Antiparasitics

Class of medications which are indicated for the treatment of parasitic diseases

53

Mechanism of Uncoating of Influenza virus A

  1. Endosomal vesicle containing virus particle move toward cell nucleus causing pH to drop
  2. Viral HA protein undergoes conformational rearrangement
  3. Viral RNAs released into cytoplasm and transported to nucleus
  4. Viral RNAs bound to M1 protein
  5. M1 forms a shell that underlies the lipid membrane
  6. Viral M2 protein form channel to pump protons from endosme into interior virion
  7. Protons lower pH releasing viral RNA from M1 protein

54

Acyclovir can be used in the treatment of

Herpesvirus infections

Feline Herpesvirus 1

Equine Herpesvirus 1