Lecture 15

Question 1

What differentiates the 4 classes of bacteria?

Answer 1

cell envelope

Question 2

What is the main function of the cell wall?

Answer 2

define shape

Question 3

What is unique about Mycoplasmas that sets them apart from the other types of bacteria? What does this uniqueness mean?

Answer 3

no peptidoglycan cell wall = less defined shape/morphology

Question 4

What are characteristics of mycoplasmas?

Answer 4

super small, no peptidoglycan cell wall, has cytoplasm and cytoplasmic membrane, can grow on lab media (no need tissue culture)

Question 5

What are mycoplasmas also called?

Answer 5

Ureaplasma

Question 6

What compensates the integrity of the plasmic membrane due to no cell wall? How do mycoplasmas obtain stability?

Answer 6

use sterols (uptake from host cells) to make membrane more stable and less fluid

Question 7

What is the morphology of mycoplasmas?

Answer 7

no morphology because of undefined shape

Question 8

What type of appearance do mycoplasma colonies have?

Answer 8

“fried egg” type of look

Question 9

What is the rate of mycoplasma growth?

Answer 9

slow: 2-4 weeks

Question 10

What tracts/parts of the body do mycoplasmas usually infect?

Answer 10

respiratory and genitourinary

Question 11

Which Mycoplasma species is most/best studied?

Answer 11

Mycoplasma pneumoniae

Question 12

What diseases does Mycoplasma pneumoniae cause?

Answer 12

tracheobronchitis, encephalitis, pneumonia (TEP)

Question 13

What are some characteristics of Mycoplasma pneumoniae?

Answer 13

respiratory mucosal surface bacterial pathogen ; could invade

Question 14

What is the reservoir of Mycoplasma pneumoniae?

Answer 14

only humans

Question 15

What are the virulence factors of Mycoplasma pneumoniae?

Answer 15

community-acquired respiratory distress syndrome (CARDS) toxin

Question 16

What toxin does the CARDS toxin resemble as/closely related to?

Answer 16

pertussis toxin

Question 17

What are methods to diagnose for Mycoplasma pneumoniae? (2)

Answer 17

PCR, antibody assays, chest x-rays

Question 18

What are treatments against Mycoplasma pneumoniae?

Answer 18

erythromycin, tetracyclin, other antibiotics not targeting peptidoglycan

Question 19

What are the antibiotics that target peptidoglycan cell wall?

Answer 19

vancomycin, bacitracin, cephalosporins, penicillin

Question 20

Define viruses.

Answer 20

obligate intracellular parasites – use host cell machinery to replicate

Question 21

What are viruses made up of?

Answer 21

nucelic acid core, protein capsid (nucleocapsid), (optional: envelope)

Question 22

What is the delivery system of the virus?

Answer 22

what the virus needs to interact with host cell to enter it

Question 23

What is the extracellular state and complete form of the virus?

Answer 23

virion

Question 24

What are capsomers?

Answer 24

subunits of protein to form capsid

Question 25

What shape can the viral genome be?

Answer 25

linear or circular

Question 26

What are the 2 morphological shapes can the virus take the form of? (the 2 common ones)

Answer 26

icosahedral and helical

Question 27

What kind of molecules do viruses synthesize in the host cell? (2 things)

Answer 27

proteins and nucleic acids — does not synthesize membrane

Question 28

Why would viruses need to use a membrane envelope? (2 reasons)

Answer 28

used to enter cells and hide from the immune system

Question 29

Why would an envelope virus not be able to infect a plant cell or a gram+ bacteria?

Answer 29

due to the plant cell wall

Question 30

What organisms can enveloped viruses infect?

Answer 30

gram– or mycoplasma bacteria and mammalian cells

Question 31

What criteria are used to classify viruses?

Answer 31

genomic makeup, morphological characteristics

Question 32

What are the 3 stages of viral replication?

Answer 32

extracellular (attachment/entry), intracellular (synthesis of macromolecules needed for assembly), assembly and exit

Question 33

How can we quantify the number of viral copies present in a cell or animal?

Answer 33

use viral titer to measure amount of virions

Question 34

In the viral titer, which stage yields the highest titer?

Answer 34

release step

Question 35

What are the 3 types of genes do viruses encode for?

Answer 35

early (immediate early), nucleic acid replication (early), late genes

Question 36

What are the 3 types of infection?

Answer 36

acute, chronic, latent

Question 37

What is the characteristic of an acute infection?

Answer 37

short period of time, short life cycle

Question 38

What is the characteristic of a chronic infection?

Answer 38

goes for a long period of time, starts as acute, long lifecycle

Question 39

What are the most common routes that viruses enter hosts?

Answer 39

respiratory, GI, transcutaneous, sexual

Question 40

What is an exogenous virus?

Answer 40

comes from environment

Question 41

What is an endogenous virus?

Answer 41

stays within the host for a long time, can get passed down, relates to latent infections

Question 42

What is transcutaneous?

Answer 42

bite from animal

Question 43

What are the common methods of spread and replication with viruses?

Answer 43

neurological system, bloodstream system, multiple pathways

Question 44

What are the diagnostic tests used to detect viruses with viral disease?

Answer 44

PCR, ELISA, antigen assays, tissue culture

Question 45

What are the 4 emerging viruses?

Answer 45

HIV, SARS, West Nile, Ebola

Question 46

What is latent infection?

Answer 46

lysogenic viruses stay dormant within host cells, causing diseases every so often, not all the time