M2-C3-L02 --> Bacterial Structure Ii

Front 1

Cell wall biosynthesis is inhibited by antibiotics:

- which specific rxn is affected?
- which specific antibiotic does this?
- explain why/how this happens

Back 1

The transpeptidation reaction is inhibited

Beta Lactam antibiotic

The Beta Lactam ring resembles the transition state of D-alanyl-D-alanine which occurs during transpeptidation.

Front 2

List the components of LPS. x3

Which ones have negative charge

Back 2

O-specific polysaccharide (neg)

Core polysaccharide (neg)

Lipase A

Front 3

What is useful about the O-specific polysaccharide in LPS?

What happens when it is lost in pathogens?

Back 3

Useful for serotyping b/c it varies among organisms.

Virulence decreases

Front 4

What is the function of the core polysaccharide in LPS?

How do enteric bacteria make this useful?

Back 4

Provides resistance to hydrophobic compounds.

Basis for resistance to bile salts.

Front 5

Lipase A:

- components
- structural function
- why clinically important?

Back 5

Saturated fatty acid

Provides rigidity

Toxic portion of LPS

Front 6

LPS outer membrane:

- significance to antibiotics
- strengthened by?
- weakened by?

Back 6

Excludes large molecules from passing through pores (such as vancomysin)

Divalent Calcium and Magnesium

EDTA

Front 7

What is the outer layer of mycobacteria made of?

what does it mean clinically?

Back 7

The outer layer of mycolic acid (lipid-like and waxy)

provides increased resistance to detergents, antibiotics, and other antibacterial agents.

Front 8

Describe the cell envelope of Mycoplasmas. x4

Back 8

No cell wall

No peptidoglycan

One membrane

Sterols in membrane

Front 9

A lipid-rich cell wall in Mycobacteria results in? x4

Back 9

1. Clumping

2. Acid Fastness

3. Resistance to detergents & PCN

4. SLOW growth

Front 10

Mycobacteria and Mycoplasma:

- type of bacteria
- type of stain

Back 10

related to gram positive

but does NOT stain positive

Front 11

Complement-mediated killing of bacteria is effective (or not effective) against which type of bacteria?

why or why not.

Killing occurs how?

Back 11

Gram NEGATIVE is susceptible

Killed by cell lysis via MAC
(Membrane Attack Complex)

Gram POSITIVE is naturally resistant

due to thick Peptidoglycan

Yet, gram positive is still opsonized by complements.

Front 12

Capsules:

- AKA x2
- Composition (exception?)

Back 12

Glycocalyx
Slime layer

Polysaccharides
(except for B. Anthracis - polypeptides)

Front 13

Which two organisms are susceptible to vaccines using capsular material?

Back 13

H. Influenzae type B

S. Pneumoniae

Front 14

What is the antigen for flagella?

Back 14

H-antigen

Front 15

What powers Flagella?

Back 15

PMF motor

Front 16

List the movements of flagella. x3

Back 16

Peritrichous - "run & tumble"

Polar reversible

Polar unidirectional

Front 17

What allows for bacteria to transfer plasma during conjugation?

Back 17

Sex pili

Front 18

Pili adherence:

- attaches to what?
- strength

Back 18

Mannose or other carbs on cell surface

Adherence increases under greater stress/resistance.
(chinese finger trap)

Front 19

Endospores formed by what type of organism?

Back 19

Some Gram Positive only

Front 20

T/F - Antimicrobial handwashing agents are sporicidal.

Back 20

False - they are not sporicidal

Front 21

What acid is found in all endospores and what is its function?

Back 21

Dipicolinic acid

Protect DNA

Front 22

What are the three stages of Endospore germination?

Back 22

Activation

Germination

Outgrowth

Front 23

What 4 events will cause the endospore germination to be ACTIVATED?

What is required for germination activation? x2

Back 23

Fresh medium
Change in T
Change in Age
Change in pH

Water
Triggering nutrient (e.g. - alanine)

Front 24

During endospore germination, what gets excreted as the cortex swells? x2

Back 24

Calcium

Dipicolinic acid

Front 25

What events occur during endospore germination, outgrowth phase? x4

Back 25

Core enlarges

mRNA synthesis begins

Spore coat ruptures

New PG formed via spore wall expansion

Front 26

What is the composition of biofilm?

Back 26

Polysaccharides

Multiple species of organisms

Front 27

What causes dental caries?

Back 27

Biofilms

Front 28

How does biofilms provide protection. x2

Back 28

Protects bacteria from antibiotics & being washed away

Protects hosts by blocking pathogens

Front 29

What are the similarities between nucleoid and plasmids? x2

Differences? x2

Back 29

Both are genetic elements
Both are circular

Nucleoid attached to inner membrane,
while plasmid do not.

Plasmids contain antibiotic resistance and virulence genes.

Front 30

What are bacterial inclusion bodies?

Back 30

Protein aggregates

(visible via microscopy)

Front 31

Ribosomes:

- composition
- function

Back 31

Proteins + RNA

mRNA translation

Front 32

Clinical significance of bacterial ribosomes.

Back 32

Good target for antibiotics

Front 33

What is the basis of what causes the toxicity in applying antibiotics to bacterial ribosomes?

Back 33

Mitochondria originated from bacteria.

Front 34

Oxidase Test:

- Detects presence of what?
- Differentiates what?

Back 34

Cytochrome C Oxidase

Pseudomonads from Enterobacteriae

Front 35

Which organism is unique because its capsule is made of polyPEPTIDES?

Back 35

B. anthracis

Front 36

List 4 virulence factors associated with capsules

Back 36

1. Anti-phagocytic

2. Poorly Immunogenic

3. Influences Adherence

4. Partial inhibition of MAC formation

Front 37

The bacterial flagellum has a motor consisting of? x2

Back 37

1. Mot complexes (stators)

2. C ring (rotors acting as a switch)

Front 38

Bacteria usually moves towards Chemotaxis with what type of movement?

Back 38

Alternating between "run" and "tumble"

Front 39

List 3 other types of motility systems besides flagellum and pili.

Back 39

1. Ratchet-based
(Flavobacterium)

2. Pilus-retraction
(Pseudomonas Aeruginoa)

3. Gliding motility
(requires contact with surface)

Front 40

What is the name given to the model depicting Bacterial Adherence?

Back 40

"shock absorber" model

Front 41

Endospores are resistant to? x6

Back 41

Antibiotics
Acids
Alcohols

Drying/Heat
Radiation

many chemical disinfectants

Front 42

Endospores are sensitive to? x4

Back 42

1. Glutaraldehyde

2. Steam

3. Peracetic acid

4. Hypochlorite

Front 43

Endospore components. x5

Back 43

Core

Spore wall

Cortex

Spore coat

Exosporum

Front 44

Which endospore layer is thickest?

Back 44

Cortex

Front 45

Describe the Endospore Core

Back 45

Genome

Protein synthesis machinary

Front 46

Describe the Endospore Spore Wall

Back 46

Contains Peptidoglycan

Front 47

Describe the Endospore Cortex

Back 47

Concentric layers
of
spore-specific
PG

Front 48

Describe the Endospore Spore Coat

Back 48

Keratin-like protein coat

Disulfide bonds ample

Front 49

Describe the Endospore Exosporum

Back 49

Remnants of mother cell membranes

Front 50

What is found in all endospores and helps protect DNA

Back 50

Dipicolinic acid

Front 51

Which stage of Endospore germination would you see a loss of temperature resistance?

- Activation
- Germination
- Outgrowth

Back 51

Germination

Front 52

Biofilms form on what 3 likely places?

Back 52

1. Solid substances in contact w/ moisture

2. Soft tissue surfaces in living organisms

3. Devices at liquid-air Interfaces
(catheters & implant devices)

Front 53

List the major Internal structures for bacteria. x5

Back 53

Nucleoid

Ribosomes

Inclusion bodies

Plasmids

Storage granules

Front 54

List 3 types of Storage granules associated with bacteria.

Back 54

1. Carbon storage polymers (PHB)

2. Polyphosphate

3. Suflur granules

Front 55

What bacterial internal structure is composed of aggregated proteins and visible under a microscope?

Back 55

Inclusion bodies

Front 56

What 5 things should clinicians know regarding PLASMIDS?

Back 56

1. Most current antibiotics produced by bacteria/fungi (thus resistant genes already exist)

2. Widespread use increases plasmids containing resistance genes

3. Natural competent bacteria are many

4. Transference of plasmids can occur among bacteria of differing species

5. Virulent only with a virulence plasmid in SOME bacterial species

Front 57

Bacterial ribosomes are responsible for?

Back 57

mRNA translation

Front 58

Large subunit of Bacterial Ribosomes can be treated with?

Back 58

Macrolides
(erythromycin, azithromycin)

Clindamycin

Chloramphenical

Front 59

Small subunit of Bacterial Ribosomes can be treated with?

Back 59

Tetracycline

Streptomycin

Front 60

Large subunit of Bacterial Ribosomes has how many proteins?

Back 60

31 proteins

in 50S

Front 61

Small subunit of Bacterial Ribosomes has how many proteins?

Back 61

21 proteins

in 30S

Front 62

Presence or absence of Cytochrome Oxidase impacts treatment plan how?

Back 62

NO impact on

- Antibiotic choice
- Treatment decisions