Lecture 5: Antibiotic Resistance + Genetic Transfer Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

how do bacteria become genetically resistant?

A

spread of resistant genes through genetic transfer acts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is competence?

A

free DNA is taken up by the cell from the environment and assimilated into genome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are 2 ways cells can become competent?

A

naturally, and by exposure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is conjugation?

A

transfer of genes from one prokaryotic cell to another through direct contact

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

conjugation is very ___ and __

A

fast and efficient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Lederberg & Tatum discovered ___ in 1946

A

bacteria share DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

how did Lederberg and Tatum show that bacteria share DNA?

A

two separate broths in minimum media would not grow colonies, byt when mixed together, they were able to form colonies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

how was it proved that cells need to touch to share DNA by conjugation?

A

U-tube with filter that wouldnt let bacteria through: no sharing even if DNA could get through

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

genes can be transferred laterally through ___

A

viruses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

how does lateral transfer of DNA work?

A

viruses package DNA from one cell and insert it into another

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

a bacteriophage inserts __ into a bacteria and begins

A

its own phage DNA; replicating itself and using the resources of the bacterial cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

phages will package new phages and sometimes accidentally incorporate ___ into them

A

bacterial DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

an infected bacterial strain can make its own __

A

tryptophan

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is transduction?

A

transfer of DNA by bacteriophage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

mutation in ribosome genes results in ___ not being effective

A

protein synthesis inhibitors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

mutations in DNA gyrase prevents __ from working, meaning ___ will happen slower

A

fluoroquinolones; unwinding and replication of DNA

17
Q

what is MRSA

A

methicilin resistant stapphylococcus aureus

18
Q

MRSA is methicilin resistant because__

A

resistant cassettes in genome caused by competence/conjugation

19
Q

what is combination therapy?

A

treatment with multiple antibiotics to reduce occurrence of near lethal exposure

20
Q

why is combination therapy more likely to work than a single antibiotic?

A

it is less likely to have 2 independent mutations in the same host in a short time. If one mutation happens, the second AB should maintain efficacy

21
Q

before a combination therapy is given, what must happen first?

A

patient lab isolates to test that the combination and sensitivity will work

22
Q

why is vancomycin resistant entercocci so dangerous?

A

just throwing their DNA around, naturally competent with many conjugative plasmids. Hard to clear infection and often results in death

23
Q

what are the dangers of MTB (XDR) in terms of spreading?

A

latent phase = carriers unaware, airborne

24
Q

what new drug was developed by Jansen Pharma?

A

Bedaquiline (TMC 207)

25
Q

what is the mechanism of Bedaquiline?

A

targets ATP synthase in MTB bacteria

26
Q

what are resistance cassettes?

A

packages of genes that cause resistance by competence / conjugation

27
Q

why has the market for drugs shifted more towards lifestyle drugs?

A

because we cant keep up with pathogens, they evolve to the anti-biotic before is can be mass produced. Lifestyle also have return customers