Final Exam Micro

Question 1

Archaeal Viruses

Answer 1

two categories:
1. Morphologically and genetically unique to Archaea
2. Clear structural and genetic homologs to both bacteriophage and eukaryotic viruses

Question 2

Techniques in Cultivating
and Identifying Animal
Viruses

Answer 2

Viruses require living cells as their “medium”
* In vivo: laboratory-bred animals and embryonic bird tissues
* In vitro: cell or tissue culture methods

Question 3

Animal Viruses

Answer 3

1. Isolate and identify
2. Prepare viruses for vaccines
3. Do detailed research

Question 4

Using Bird Embryos: in vivo still

Answer 4

1. Intact and self-supporting unit
2. Sterile environment
3. Contain their own nourishment
   Most common: Chicken, duck, and
   turkey eggs

Question 5

Using Cell (Tissue) Culture Techniques: in vitro

Answer 5

Cell culture, or tissue culture:
1. Grown in sterile chambers with special media that contain the correct
nutrients for cells to survive
2. Cells form a monolayer, or single, confluent sheet of cells that supports
viral multiplication
3. Allows for the close inspection of culture for signs of infection

Question 6

Detection of Viral
Growth in Culture

Answer 6

Observation of degeneration and lysis of infected cells
- Plaques: areas where virus-infected
cells have been destroyed show up as
clear, well-defined patches in the cell
sheet (absence of growth) (transparent)

Question 7

Plaques

Answer 7

this same technique is used to detect and count bacteriophages
- when host cell is lysed that is what make the plaque

Question 8

Prions – “proteinaceous infectious particle”

Answer 8

Misfolded proteins → transmit their misfolded shape onto normal variants of the same protein
- no nucleic acid, just protein

Question 9

Prions

Answer 9

Class of infectious diseases called transmissible spongiform encephalopathies (TSEs)

Question 10

Human diseases

Answer 10

• Creutzfeldt-Jakob Disease (CJD)
• Variant Creutzfeldt-Jakob Disease
  (vCJD)
• Gerstmann-Straussler-Scheinker
  Syndrome

Question 11

Animal diseases

Answer 11

• Bovine Spongiform Encephalopathy (BSE)
• Chronic Wasting Disease (CWD)

Question 12

Creutzfeldt-Jakob
Disease (CJD) - Classical

Answer 12

• Neurodegenerative disorder → rapidly progressive → 100% mortality rate
• occurs sporadically
• Inherited forms include: Gerstmann-Straussler- Scheinker syndrome and fatal familial insomnia
• not related to “mad cow”
• long incubation period

Question 13

Creutzfeldt-Jakob
Disease (CJD) - Classical

Answer 13

Kuru - likely related
- papua new guinea
- Result of ritualistic cannibalism
- spread the disease through cannibalism

Question 14

Bovine Spongiform Encephalopathy (BSE)

Answer 14

“mad cow”
- occurred in the 1970s (identified in 1986)
- caused by spontaneously occurring
case of BSE or scrapie-infected sheep products
- grounded up meat and bone from grain might have contained prions from that disease

Question 15

Creutzfeldt-Jakob Disease (vCJD) - Variant

Answer 15

• 1996
• Strong evidence that agent responsible for vCJD in humans is the same agent responsible for BSE in cows
• unique genetic profile of the prion
• genetic profile allows separation from BSE

Question 16

Chronic Wasting Disease (CWD)

Answer 16

Canada, United States, Norway, Finland, Sweden, and South
Korea
- does not appear to naturally infect cattle

Question 17

Subviral particles

Answer 17

smaller than the virus

Question 18

Satellite virus

Answer 18

Encode their own capsid protein

Question 19

Satellite Nucleic Acid

Answer 19

No capsid protein

Question 20

Satellites: Viruses & Nucleic Acids

Answer 20

Dependent on other viruses for replication

Question 21

Hepatitis D:

Answer 21

the worst
- messes up liver
- highest fatality
- satellite virus: requires hepatitis B

Question 22

hepatitis B virus

Answer 22

has a vaccine, D is dependent on B

Question 23

Viroids

Answer 23

Composed of naked strands of RNA, lacking a capsid or any other type of coating
- infect crops
- parasitize plants

Question 24

virus

Answer 24

treatment is difficult
- because they remain infectious for a long period outside of body
- kill virus, kill host cell too

Question 25

Treatment of Animal Viral Infections

Answer 25

antivirals - target one of the steps in the viral life cycle - Easier to develop vaccines to prevent viral diseases

Question 26

Rhinovirus “Of the Nose”: common cold

Answer 26

Most common viral infectious agent in humans - major cause of common cold - Most affected: infants, elderly, immunocompromised - No vaccines

Question 27

Human Papillomavirus - HPV

Answer 27

Commonly infects skin and mucous membranes - warts - Most common sexually transmitted infection in the US - Can also spread from mother to baby (pregnancy)

Question 28

vaccine of HPV

Answer 28

Gardasil-9 (9vHPV HPV16 and HPV18 focus on - cause majority of cervical cancers

Question 29

HPV16

Answer 29

is responsible for almost 90% of HPV-positive oropharyngeal cancers

Question 30

Varicella zoster virus (Chickenpox and Shingles)

Answer 30

highly contagious - latent (permanent) infection in nerve cells - reactivates as shingles - vaccine available (1995)

Question 31

Chickenpox and Shingles causative

Answer 31

Varicella zoster virus

Question 32

Shingles

Answer 32

After a person recovers from chickenpox, the virus stays dormant (inactive) in their body. The virus can reactivate later, causing shingles - painful rash - contagious - 10-18% will experience postherpetic neuralgia

Question 33

Poliomyelitis (Polio)

Answer 33

Caused by poliovirus - not have visible symptoms - Small portion will develop severe symptoms → meningitis and/or paralysis - Paralysis is the most severe symptom → 2-10% will die → virus affects the muscles that help them breathe - Lives in the throat and intestines - no cure

Question 34

Polio vaccine

Answer 34

Inactivated poliovirus vaccine (IPV) given as an injection in the leg or arm (99% effective in children) (USA) Oral poliovirus vaccine (OPV) (drops in mouth) is still used throughout much of the world

Question 35

Variola virus (Smallpox)

Answer 35

- Only in humans - caused by variola virus - very contagious - first sores appeared in mouth and throat - Distinctive fever & progressive skin rash - 30% mortality rate - permanent scars

Question 36

Smallpox

Answer 36

- vaccination success - Last natural outbreak of smallpox in the US occurred in 1949 - World Health Assembly declared smallpox eradicated in 1980 - agent of bioterrorism

Question 37

Rabies (causative)

Answer 37

Rabies lyssavirus

Question 38

Rabies

Answer 38

- Varied incubation period - Direct contact - Hydrophobia: swallowing triggers uncontrollable spasms of the throat muscles when victims try to drink

Question 39

Flu

Answer 39

Influenza

Question 40

flu

Answer 40

- Higher risk: young, elderly, immunocompromised, certain health conditions - Complications: pneumonia, ear infection, sinus infection, worsening of chronic medical conditions (asthma, diabetes, congestive heart failure)

Question 41

help with it

Answer 41

Tamiflu (Oseltamivir) * Neuraminidase inhibitor - Yearly - quadrivalent

Question 42

Ebola Virus Disease

Answer 42

Ebola virus (species Zaire ebolavirus) (most devastating) - Hemorrhagic virus - bats and body fluids