Brainscape's Knowledge GenomeTM

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


See full index

MICRB 201 > Chapter 12 > Flashcards

Chapter 12 Flashcards

1
Q

What is the goal of antimicrobial chemotherapy?

A

Administer a drug to an infected person that destroys the infective agent without harming the host’s cells

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

What is prophylaxis?

A

Use of a drug to prevent imminent infection of a person at risk

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

What is antimicrobial chemotherapy?

A

The use of drugs to control infection

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

What are antimicrobials?

A

Any antimicrobial drug, regardless of what type of microbe it targets

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

What are antibiotics?

A

Substances produced naturally or synthetically that can inhibit or destroy microbes, namely bacteria

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

What are semisynthetic drugs?

A

Drugs that are chemically modified in the lab after being isolated from natural resources

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

What are synthetic drugs?

A

Drugs produced entirely by chemical reactions in a lab setting

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

What is narrow-spectrum?

A

Antimicrobials effective against a limited array of microbial types

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

What is broad-spectrum?

A

Antimicrobials effective against a wide variety of microbial types

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

How are antibiotics naturally synthesized?

A

As common metabolic products of bacteria and fungi

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

Why do bacteria and fungi produce antibiotics?

A

To reduce competition for nutrients and space

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

What three factors must be known before starting antimicrobial therapy?

A
  1. Microbe identity
  2. Degree of microbe’s susceptibility
  3. Overall medical condition of the patient
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the Kirby-Bauer technique?

A

Technique for testing drug susceptibility that involves plating bacterium on a plate of special medium and placing antibiotic discs onto the plate in order to observe zones of inhibition

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

What is an antibiogram?

A

A profile of antimicrobial sensitivity

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

What is the minimum inhibitory concentration (MIC)?

A

The smallest concentration of drug that visibly inhibits growth

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

What factors can lead to treatment factor?

A
  1. Inability of drug to diffuse into infected body compartment
  2. Resistant microbes in infection that were not in the tested sample
  3. A polymicrobial infection in which some pathogens are resistant to the drug
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the therapeutic index (TI)?

A

Ratio of toxic drug dose to humans to minimum effective dose

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

Which TI values indicate greater potential for toxic drug reactions?

A

Smaller ratios (when the two values are closer together)

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

What preexisting conditions must be considered when prescribing drugs?

A
  1. History of allergy
  2. Underlying liver or kidney disease
  3. Patients that are infants, elderly, or pregnant
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is selective toxicity?

A

Antimicrobial drugs should kill or inhibit microbial cells without damaging host tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Why do penicillins have excellent selective toxicity?

A

They block the synthesis of the cell wall found only in bacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Which drugs are most toxic to human cells?

A

Those that act upon a structure common to both the infective agent and the host cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the metabolic targets of chemotherapeutic agents?

A

Inhibition of cell wall synthesis, inhibition of nucleic acid structure and function, inhibition of protein synthesis, interference with cell membrane structure or function, inhibition of folic acid synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Which antibacterial drugs target the cell wall?

A

Penicillins, cephalosporins, carbapenems, bacitracin, isoniazid, vancomycin

25
Q

What suffix is typical of penicillin drugs?

A

-cillin

26
Q

What prefixes are typical of cephalosporin drugs?

A

cep-, cef-

27
Q

What suffixes are typical of carbapenem drugs?

A

-nem, -nam

28
Q

Which antibacterial drugs target protein synthesis?

A

Aminoglycosides, tetracyclines, glycylcyclines, macrolides, clindamycin, synercid, linezolid

29
Q

Which antibacterial drugs target folic acid synthesis?

A

Sulfanamides

30
Q

Which antibacterial drugs target DNA and/or RNA?

A

Fluoroquinolones

31
Q

What suffix is typical of fluoroquinolone drugs?

A

-acin

32
Q

Which antibacterial drugs target cell membranes?

A

Polymyxins, daptomycin

33
Q

Why are bacteria in biofilms less sensitive to the same antimicrobials that work against them when they are free living?

A

Bacteria in biofilms express different phenotypes than the free-living bacteria

34
Q

Why are anti-fungal drugs more harmful to humans than antibiotics?

A

Fungal and human cells are both eukaryotes and have more similarities

35
Q

What are the four main anti-fungals currently in use?

A

Polyene antibiotics, azoles, echinocandins, allylamines

36
Q

What drugs were/are used to treat malaria?

A

Quinine (previously), chloroquine, primaquine

37
Q

What treatments are available for protozoan infections?

A

Metronidazole, amoebicide

38
Q

What drugs are used to treat helminth infections?

A

Albendazole, pyrantel, praziquantel, invermectin

39
Q

What are the three major modes of action for antiviral agents?

A
  1. Barring penetration of the virus into the host cell
  2. Blocking the replication, transcription, and translation of viral molecules
  3. Preventing maturation of viral particles
40
Q

What is drug resistance?

A

Adaptive response in which microbes begin to tolerate an amount of drug that would ordinarily be inhibitory

41
Q

What caused drug resistance?

A

Genetic versatility and adaptability of microbial populations

42
Q

What is intrinsic drug resistance?

A

Bacteria must be resistant to any antibiotic that they themselves produce

43
Q

What is acquired drug resistance?

A

Bacterial resistance to a drug to which they were previously sensitive

44
Q

Through what methods does drug resistance develop?

A
  1. Spontaneous mutation

2. Horizontal transfer of R factors or transposons

45
Q

What are the mechanisms of drug resistance?

A
  1. New enzymes are synthesized that inactivate drug
  2. Permeability/drug uptake is decreased
  3. Binding sites for drug are decreased/lower affinity
  4. Affected metabolic pathway is shutdown/alternate pathway is used
  5. Drug is immediately eliminated
46
Q

Why does natural selection favor drug resistance?

A

When a drug is introduced to a population, those microbes that are sensitive will die, leaving only the resistant bacteria to repopulate

47
Q

What percent of antibiotic prescriptions are prescribed for non-bacterial infections/ailments?

A

75%

48
Q

What is the “shotgun” approach to antimicrobial therapy?

A

Antibiotics are prescribed first, without determining if the infection is indeed bacteria related

49
Q

What is the hospital factor?

A

Hospital environment continually exposes pathogens to a variety of drugs, causing pathogens to develop resistance more rapidly than in nature

50
Q

What percent of all antibiotics are given to livestock in the U.S.?

A

80%

51
Q

Why is it an issue to give livestock antibiotics?

A

Their enteric bacteria become drug resistant and can spread to humans, causing resistant infections

52
Q

What are probiotics?

A

Preparations of live microorganisms fed to animals and humans to improve intestinal biota

53
Q

What are prebiotics?

A

Nutrients that encourage growth of beneficial microbes in the intestine

54
Q

What is a fecal transplant?

A

Involves transfer of feces, containing beneficial normal biota, from healthy to affected patients via colonoscopy

55
Q

What are the categories of major side effects from drugs?

A
  1. Direct damage to tissues through toxicity
  2. Allergic reactions
  3. Disruption in balance of normal microbiota
56
Q

Which organs are most commonly impacted by drugs?

A

Liver, kidneys, GI tract, cardiovascular system, nervous system, respiratory tract, skin/bones/teeth

57
Q

What is the most common complaint associated with oral antimicrobial therapy?

A

Diarrhea

58
Q

Why do drugs sometimes cause allergy?

A

Drug acts as an antigen that stimulates allergic response

59
Q

What is a superinfection?

A

Infection that occurs when beneficial resident species are destroyed through antibiotic therapy, allowing other microbes to overgrow and cause disease

MICRB 201 (15 decks)

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