Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Exam 2 MIM Microbiology > Antimicrobial Therapy > Flashcards

Antimicrobial Therapy Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

What are the four categories of antimicrobials?

A

1) antibacterials
2) antivirals
3) antifungals
4) antiparasitics

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

What are the three main methods of non-selective killing of microbes?

A

1) sterilization
2) disinfection
3) antisepsis

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

What is sterilization?

A

The complete destruction of all microbes and spores

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

What is disinfection?

A

The destruction of most all microbes

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

What is antisepsis?

A

The use of disinfectants on the skin

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

What are some methods for sterilization?

A

1) autoclave
2) ethylene oxide gas
3) pressured steam

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

What are some disinfectant agents?

A

1) phenolics

2) iodophors

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

What is the central tenet to the clinical application of antimicrobials?

A

selective toxicity

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

What were some of the first antibacterials?

A

1) sulphonamide
2) pencillin
3) streptomycin

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

What is an “antibiotic”?

A

A secretion from a microbe that kills another bacteria

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

What is MIC? MBC?

A

MIC - minimum inhibitory concentration. the minimum concentration of drug needed to prevent growth
MBC - minimum bactericidal concentration. the minimum concentration of drug that kills 99.9% of the microbial population

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

What is the name of an antimicrobial which leads to the “stationary growth” of a bacterial population?

A

bacteriostatic

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

What is one way in which to get an MIC?

A
  • serial dilutions

- E-test for abx sensitivity

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

What is the difference between MIC/MBC and resistance/sensitivity?

A

MIC and MBC are quantitative values. Resistance and sensitivity are clinical values.

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

What is the Kirby-Bauer method?

A

Disk diffusion assay in petri dish/agar culture. Disks impregnated with abx are then placed with the microbial culture

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

What is the difference between narrow and broad spectrum antibiotics?

A

Narrow-spectrum antibiotics usually only work against Gram-positive bacteria, while broad-spectrum antibiotics will work against both Gram-positive and Gram-negative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are three contributing factors to antibiotic susceptibility?

A

1) targeting the access of the abx to the bacterium
2) targeting the affinity of the abx to whatever its target is
3) susceptibility to its own inactivation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the five major mechanistic classes of antibiotics?

A

1) cell wall biosynthesis inhibitors
2) protein biosynthesis inhibitors
3) nucleid acid biosynthesis inhibitors
4) metabolic inhibitors
5) membrane disrupting agents

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How do abx target cell wall biosynthesis?

A

The synthesis of the peptidoglycan layer has several steps that occur throughout the cell and different abx can inhibit the different steps of this process

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the peptidoglycan layer also called?

A

murein layer

21
Q

What are examples of some abx which affect cell wall biosynthesis?

A

1) penicillin
2) vancomycin
3) bacitracin
4) carbapenems

22
Q

What is a beta-lactam abx?

A

Beta-lactam antibiotics are abx that have a cyclic amide group. This mimics a peptide bond.

23
Q

How are cell wall synthesis inhibitors selective?

A

There are no cell walls in mammals and thus they cannot be targeted

24
Q

What are some side chain modifications of penicillin and what do they do?

A

Penicillin G is the original penicillin, but could not be given orally. Pencillin V can be taken orally. Ampicillin and piperacillin are more effective against Gram negatives

25
Q

What do the different generations in cephalosporins indicate generally?

A

side chain modifications

26
Q

What do all beta-lactams have in common in their mechanism of action?

A

They all prevent the final cross-linkage in the cell wall

27
Q

What do bacteria use to overcome beta-lactam abx?

A

beta-lactamase inactivates these abx

28
Q

What do we use to overcome beta-lactamase?

A

Beta-lactamase inhibitors

29
Q

What are some beta-lactamase inhibitors?

A

Clavulanic acid and sulbactam

30
Q

What is Augmentin?

A

Augmentin is amoxicillin with a beta-lactamase inhibitor, clavulanic acid.

31
Q

What do beta-lactams do in addition to inhibiting penicillin-binding protein?

A

activate cell wall degradation enzymes

32
Q

How does the bacterium die when it is treated with penicillin?

A

bacteria will expand, as cell wall is weakened, it will balloon out in response to osmotic forces and then rupture.

33
Q

Isoniazid and ethambutol are cell wall inhibitors of which bacteria?

A

Mycobacteria, because they have different cell wall structures

34
Q

What are some protein biosynthesis inhibitors?

A

aminoglycosides, tetracyclines, macrolides

35
Q

How are protein biosynthesis inhibitors selective?

A

Bacterial ribosomes are different in composition than mammalian ribosomes

36
Q

What are some side effects of protein biosynthesis inhibitors?

A

They may inhibit mitochondrial ribosomes due to their similarity to prokaryotic ribosomes

37
Q

What are some nucleic acid biosynthesis inhibitors?

A

rifamycins, quinolones, and metronidazole

38
Q

How do rifamycins work?

A

inhibition of RNA synthesis

39
Q

How do quinolones work?

A

inhibition of topoisomerases which supercoil DNA

40
Q

How does metronidazole work?

A

clipping DNA in anaerobic bacteria

41
Q

What are some metabolic inhibitors?

A

sulfonamides and trimethoprim

42
Q

How do sulfonamides work?

A

Sulfonamide is an analog of PABA, a precursor of folic acid

43
Q

How is inhibiting the production of folic acid selective?

A

Folic acid enzymes are unique to microbes. Structural differences in enzymes between species.

44
Q

How do membrane disrupting agents work?

A

They bind membrane and create pores which lead to bacterial rupture

45
Q

What are some examples of membrane disrupting agents?

A

colistin and daptomycin

46
Q

What is an example of host-drug interactions governing abx use?

A

Furantoin is excreted quickly and through the urinary system which makes it great for UTIs

47
Q

How does antimicrobial resistance work?

A

natural selection leads to preferential selection of genes that would resist antibiotics

48
Q

What is the resistome?

A

The catalog of abx resistance genes in the microbial environment

49
Q

What are three biochemical mechanisms of abx resistance?

A

1) altered permeability of abx in bacteria
2) modified targets
3) drug modification

Exam 2 MIM Microbiology (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions