Brainscape's Knowledge GenomeTM

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


See full index

Microbiology > Ch. 20 > Flashcards

Ch. 20 Flashcards

1
Q

Selective toxicity

A

Antimicrobial drugs are chemicals that kill microbial cells but not host cells

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

Narrow spectrum

Ex:

A

Treats a smaller range of different microbial types.

Ex.: penicillin G affects gram-positive but very few gram-negative bacteria

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

Broad-spectrum

A

Antibiotics treat a broad range of gram-positive and gram-negative bacteria

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

Bactericidal

A

Kill microbes directly

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

Bacteriostatic

A

Prevent microbes from growing (host uses phagocytosis and anti-bodies to destroy microbe)

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

What is a superinfection?

A

And overgrowth of a pathogen that has developed a resistance to an antibiotic.
An antibiotic resistant strain replaces the original sensitive strain, and the infection continues.

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

What are the five major anabiotic mode of action?

A
  1. Inhibitors of cell wall synthesis
  2. Inhibitors of protein synthesis
  3. Injury to the plasma membrane
  4. Inhibitors of nucleic acid replication and transcription
  5. Inhibition of essential metabolite synthesis.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Chemotherapy

A

The treatment of disease by the use of chemical substances. Paul Ehrlich from Germany coined the term chemotherapy where he was looking for a magic bullet to destroy pathogens without harming their host.
1909

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

How does selective toxicity work?

A

Antimicrobial drugs must often act within the host without damaging the host. Antimicrobial drugs act by killing or by interfering with the growth of microorganisms.

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

What causes a super infection?

A

A broad-spectrum antibiotic that does not destroy certain organisms in the normal microbiota but does destroy their competitors, the survivors may flourish and become opportunistic pathogen’s that sometimes occurs in overgrowth by the east like fungus Candida albicans

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

In order for antibiotics to be effective it must be able to demonstrate?

A

Selective toxicity

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

Antibiotic therapy is a form of?

A

Chemotherapy

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

Where do most antibiotics come from?

A

Bacteria (most from the filamentous soiled bacteria)

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

In Table 20.2, what is the spectrum of activity of antibiotics and other antimicrobial drugs showing?

A

The bacterial (prokaryotes) antibiotics have a broader spectrum then the fungal (eukaryote) ones.

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

Which is better a broader or narrow spectrum anabiotic and why?

A

Narrow because the broad-spectrum wipes out everything including the normal microbiota and contributes to anabiotic resistance.

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

What are some acceptable uses of broad-spectrum antibiotics?

A
  • When there’s question about what the patient may be infected with
  • Prophylaxes for most surgical procedures
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the different groupings of penicillin?

A

Natural

Semisynthetic

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

What does natural penicillin work mainly on?

A
  • Gram-positive bacteria and spirochetes

* Penicillin G & Penicillin V

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

Penicillinase is also known as?

A

B-lactamases

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

What is penicillinase?

A

Enzymes that break down the B-lactam ring

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

In order for antibiotics to be effective it must be able to demonstrate?

A

Selective toxicity

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

Antibiotic therapy is a form of?

A

Chemotherapy

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

In Table 20.2, what is the spectrum of activity of antibiotics and other antimicrobial drugs showing?

A

The bacterial (prokaryotes) antibiotics have a broader spectrum then the fungal (eukaryote) ones.

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

Which is better a broader or narrow spectrum anabiotic and why?

A

Narrow because the broad-spectrum wipes out everything including the normal microbiota and contributes to anabiotic resistance.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are some acceptable uses of broad-spectrum antibiotics?

A
  • When there’s question about what the patient may be infected with
  • Prophylaxes for most surgical procedures (Abdominal or G.I. tract in particular, if there’s any bacteria that leak out of the organ system and into the abdominal cavity, which is a life-threatening infection)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Three groups of beta-lactam antibiotics (Inhibitors of cell wall synthesis). In the order of development:

A

1) Penicillin
2) Cephalosporins
- On the fifth generation
3) Carbapenems

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are the different groupings of penicillin?

A

Natural

Semisynthetic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What does natural penicillin work mainly on?

A
  • Gram-positive bacteria and spirochetes

* Penicillin G (Injection) and Penicillin V (Orally)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Penicillinase is also known as?

A

B-lactamases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What are the advantages of a semisynthetic penicillin?

A
  • Broad-spectrum

* Resistant to penicillinase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What are some examples for semisynthetic?

A
  • Ampicillin
    Is still susceptible to some penicillinase but has ^ the spectrum of activity. Gram-negative.
  • Amoxicillin
  • Oxacillin
    Narrow Spectrum. Doesn’t give an increase spectrum but it’s more resistant to penicillinase and for gram-positive only.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Carbapenems

A
  • Primaxin
  • Doripenem
    Useful against a host of bacterial infections including pseudomonas
33
Q

What’s the most common penicillin that can block B-lactamases?

A

Augmentin (Amoxicillin + Clavulanic Acid)
This blocks B-lactamase non-competitively. It’s a non-competitive inhibitor. It binds to a site other than the active site, but still disabled the enzyme.

34
Q

What do penicillinase/B-lactam love to attack?

A

B-lactam ring

35
Q

What bacteria have become resistant to carbapenem?

A

KPC (Klebsilla Pneumonaie)

36
Q

Why was Cephalosporins developed?

A

Because the bacteria began making penicillinase and became antibiotic resistant to penicillin

37
Q

What antibiotics inhibit protein synthesis?

A

1) Tetracyclines

2) Macrolides

38
Q

Tetracycline

A
  • Trade name is Doxycyline
  • Don’t use if pregnant
  • Used to treat STI’s (particularly chlamydia), a variety of gram positive and gram negative bacteria, respiratory infections, and Rickettsias
39
Q

Macrolides

A
  • Erythromycin
  • Azithromycin
    - Used to treat: Sinus and Ear infection
40
Q

Why do they call them Macrolides?

A

Because of the big complex ring, macrocyclic lactone ring

41
Q

Why do they call these chemical group tetracycline?

A

Because it has four cyclic ring structures

42
Q

What are The different drugs that belong to the antifungal group?

A
  • Polyenes

* Azoles

43
Q

The common standby antifungal drugs belongs to a group called the Polyenes, what’s it called?

A

Amphotericin B

44
Q

Most antifungal’s interfere with the incorporation of ______ into the cell membrane.

A

Ergosterol

45
Q

What type of sterol do mammals like us have in our cell membrane, but you don’t find them in plants?

A

Cholesterol

46
Q

Competitive enzyme inhibition includes what?

A

Sulfonamides

Sulfa Drugs

47
Q

What’s the third and last line of defence and the most potent that inhibit cell wall synthesis of the B-lactam drugs?

A

Carbapenems

48
Q

Are broad-spectrum is resistant to penicillinase?

A

Yes, A noncompetitive inhibitor. It binds to a site other than the active site, but still disabled the invite

49
Q

What group/genus of bacteria often make penicillinase?

A

Staphylococcus (Beginning to get VERSA )

50
Q

How does Amoxicillin and Clavulanic Acid work together?

A
  • Amoxicillin is semi synthetic penicillin

* Clavulanic Acid is the compound that in activates penicillinase.

51
Q

How do natural and semisynthetic penicillin structurally differ and what to do they have in common?

A
  • Common: Nucleus and B-lactam ring

* Differ: R groups (The side group that’s attached to the common nucleus)

52
Q

What does semisynthetic mean?

A

You originally get it from a natural source and then begin tweaking it.

53
Q

Why do the cephalosporins keep growing and generations?

A

Because of resistance

54
Q

What are the antibiotics that don’t require a prescription for?

A
  • Bacitracin
  • Neomycin (Broad-spectrum aminoglycoside)
  • Polymyxin B
    • Topical ointment
55
Q

Why isn’t a prescription needed for those three antibiotics?

A

Because they’re available in small dilute quantities but work just as well

56
Q

Antimycobacterial Antibiotics:

Name antimycobacterial antibiotic:

A

Isoniazid

57
Q

Antimycobacterial antibiotic:
Isoniazid is taken in combination with?
They treat?

A
  • Rifampin
  • Ethampin
  • Used to treat TB
58
Q

What does antimycobacterial antibiotics inhibit?

A
  • Inhibit the synthesis of mycolic acid, which is the waxy stuff, so the cell wall is denied mycolic acid so it falls apart.
  • So they either inhibit the synthesis of mycolic acid or allow it but blocks it’s intersection into the cell wall
59
Q

Antimycobacterial Antibiotic:

Name some facts about Teixobactin?

A
  • Known as the next big break through anabiotic
  • Interfere with cell wall synthesis
  • Been demonstrated in all non-human trials to knock out all gram-positive bacteria including MRSA
  • Disrupts the synthesis of teichoic acid, which is an integral part of the cell wall it will fall apart without these acids
60
Q

Nucleic acid synthesis inhibitors include what?

A

Fluroquinoines

61
Q

Name some of the well known Fluroquinoines and what are they commonly used for:

A
  • Ciprofloxacin
    • Originally for anthrax
  • Levoquin
  • Norfloxacin
  • Use for UTIs and pneumonia
62
Q

Competitive and Enzyme inhibition:

Was probably the most famous sulfonamide drug, what’s the combination of this drug and what’s it used to treat?

A
  • Bacterium
  • Combination: Sulfamethoxazole-Trimethoprim)
  • Treats: MRSA and UTI
63
Q

Azoles

A
  • Ex: Miconazole (Vaginal yeast infection) and Clotrimazole (Athletes foot)
  • Both topical application
64
Q

Name some anti-protozoan drugs:

A
  • Flagyl

* Artemisinin

65
Q

Anti-protozoan drug:

What is Flagyl used to treat?

A

Treats vaginitis caused by Trichomonas vaginitis (Works because it’s a protozoan)

66
Q

Anti-protozoan drug:

Artemisinin

A
  • It’s a plant extract used to prevent and treat malaria
  • Consider the last line of defense against malaria, the last chemotherapeutic agent of defense and treatment.
  • Roughly 3 years ago artemisinin resistant malaria came out
  • They’re trying something called ACT (Artemisinin Combinatorial Therapy) where they’ll combine artemisinin with quinin based drugs in an attempt to prevent it as well as knock it out
67
Q

Name an anthelminthic drug and what’s used to treat?

A
  • Niclosamide

* Treats Tapeworm Infections

68
Q

Why did scientist start getting into the semisynthetic penicillins?

A

Because of the resistance and you can broaden its spectrum

69
Q

What does penicillin do?

A

It blocks the enzyme that assembles the rods of the carbohydrate backbones.

70
Q

What’s inside the common nucleus that’s attacked at penicillinase?

A

B-lactam ring

71
Q

What’s the most commonly prescribed B-lactam antibiotics?

A

Cephalosporins

72
Q

What are some examples of cephalosporins?

A
  • Cephalothin

* Cefixime

73
Q

Why were the carbapenes developed?

A

To increase the spectrum of activity and because of their resistance to penicillinase

74
Q

What group does vancomycin belong to?

A

Polypeptide antibiotic, also inhibits cell wall synthesis but not a B-lactam drug

75
Q

R Factor

A

A plasmid that allows bacteria to become resistant to one or more antibiotics

76
Q

HAART

A
  • Highly active antiretrovirals therapy

* Cocktail therapy for HIV

77
Q

What are some common ways bacteria can defeat antibiotics?

A

1) Block the entry
2) Efflux pumps
3) Inactivates enzymes
4) Alter the target molecule

78
Q

The most famous Fluroquinoines ?

A

Ciprofloxacin

79
Q

Vancomycin treats ?

A

C. difficile and MRSA

Microbiology (19 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions