Brainscape's Knowledge GenomeTM

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


See full index

Bacteriology F > Antibiotics > Flashcards

Antibiotics Flashcards

1
Q

The 5 main target sites for antibacterial agents:

A
  • cell wall synthesis
  • cytoplasmic membrane function
  • protein synthesis
  • nucleic acid synthesis
  • metabolic pathway
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Which antibacterial agent has the best selective toxicity?

A

Antibacterial agent targeting cell wall synthesis because human cells do not have cell wall

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

Famileis of drugs that inhibit Send wall synthesis

A
  • Beta lactams including monobactams, carbapenem, penicillin and cephalosporins.
  • Glycopeptides including vancomycin
  • bacitracin
  • subactams
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Antibiotics inhibiting cell wall synthesis are bactericidal or bacteriostatic?

A

Bactericidal

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

What is the target beta lactams?

A

Penicillin binding proteins

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

What is beta-lactamase?

A

An enzyme produced by bacteria that provides multi resistance to beta-lactam antibiotics

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

Bacteria that beta-lactam can’t act on:

A

Bacteria that do not have a cell wall like mycoplasma and intracellular bacteria

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

Inhibitors of beta lactamase:

A

Clavulanic acid and sulbactam

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

Mechanism of action of beta-lactams

A

They will bind to transpeptidase active site of penicillin binding proteins thus inhibiting the formation of cross linking and cell wall synthesis

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

All penicillin antibiotics are sensitive to the acidity of the stomach except those two:

A

Amoxicillin and penicillin V

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

Penicillins that are resistant to beta lactamase:

A

Nafcillin, oxacillin and methicilin

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

Penicillin V:

A

Active against gram-positive bacteria

Sensitive to Beta lactamase

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

Oxacillin methicillin and nafcillin:

A

Less active against gram-positive and inactive against gram negative
Resistant to beta lactamase

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

Ampicillin and piperacillin:

A

Active against gram positive and gram negative bacteria

Sensitive against beta lactamase

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

Amoxicillin

A

Less sensitive to beta lactamase
Taken orally
Better absorbed than ampicillin

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

Penicillin V

A

Acts like penicillin G but taken orally

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

MRSE

A

Methicillin resistant staphylococcus epidermidis

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

MRSA

A

Methicillin resistant staphylococcus aureus

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

How resistance is acquired by staphylococcus bacteria?

A

They have a MECA gene which will Produce new penicillin binding proteins that have a lesser affinity to penicillin and at the same time inactivating normal penicillin binding proteins.

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

ESBL

A

Extended spectrum beta lactamase

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

How beta lactamase inactivate penicillin?

A

By converting the 6-aminopenicilanic acid which is the compound that has the anti-bacterial activity, into 6-aminopenicilloic acid inactive against bacteria but have a property of an hapten

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

Hapten:

A

It is a molecule that has lost its capacity to produce disease but has preserved its antigenicity and can stimulate the immune system causing an allergic reaction

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

manifestations of an allergic reaction due to penicillin;

A

Skin rash and edema

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

Clavulanic acid

A

It’s a suicide inhibitor that has the capacity to inhibit the activity of beta lactamase.
It can’t be administered alone since it has o anti-microbial or antibacterial properties so it should be combined with another antibiotic and the junction with beta lactamase will make this antibiotic more effective.

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

First generation of cephalosporins

A

Activity similar to ampicillin

More active against gram-positive and less against gram-negative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Second generation of cephalosporins

A

Expended activity against Enterobacteriaceae which our gram-negative bacilli except Pseudomonas
Less active against gram-positive cocci
Active against haemophilus and anaerobes and can cross the blood brain barrier

27
Q

Third generation of cephalosporins

A

More expanded activity against Enterobacteriaceae including Pseudomonas
Less active against gram-positive cocci and can cross the blood brain barrier

28
Q

Fourth generation of cephalosporins

A

Active against pseudomonas

Active against streptococcus and methicillin susceptible staphylococcus

29
Q

Superinfection

A

When we give an antibiotic which is more active against gram-negative bacteria for example in an E. coli infection, the normal flora will be imbalanced, this will activate certain bacteria like staphylococcus aureus causing a superinfection. In this case the antibiotic given is only treating the E. coli and complications will appear due to staph infection.

30
Q

Broad-spectrum antibiotic

A

Antibiotic covering many types of bacteria like gram-negative, gram-positive, aerobics, anaerobic…

31
Q

Most broad-spectrum antibiotic:

A

Carbapenems

They are active against gram-negative, gram-positive and anaerobes (Including Pseudomonas)

32
Q

Monobactam

A

Limited to Gram-negative bacteria

Resistant against beta-lactamase

33
Q

Origin of bacitracin

A

Bacteria called Bacillus Subtilis

34
Q

Bacitracin

A

Active against positive bacteria
It is poorly absorbed by the G.I. tract and has many toxic side effects so it is not given systemically it’s only given externally as an ointment against gram-positive bacteria.
It prevents the phosphorylation of phospholipid carriers like Bactoprenol
It prevents regeneration of carriers necessary for synthesis to continue.

35
Q

Vancomycin

A

It’s a glycopeptide that acts only against gram-positive bacteria since it cannot cross the outer membrane of negative bacteria due to its size
It prevents the separation of the fifth amino acid so it acts at the level of the element D Alanine-D-Alanine inhibiting formation of cross linking

36
Q

Resistance to vancomycin

A

Some bacteria have D-alanine-D-lactate where vancomycin can’t act.
Other bacteria like enterococci have a chromosomal mediated resistance to vancomycin

37
Q

Antibiotic Associated Diarrhea

A

When we are taking an antibiotic against a certain type of bacteria other bacteria that are part of our normal flora will increase the number and become pathogenic causing bacteria

38
Q

Antibiotic used to treat antibiotic associated diarrhea

A

Vancomycin and metronidazole

39
Q

Polymyxin B

A

Active only against gram negative bacteria
Binds to lipid A and phospholipids then cause disruption of cytoplasmic membrane causing the destruction of the whole bacteria cell

40
Q

Antibiotics that bind 30 S subunit of ribosomes

A

Aminoglycosides and tetracyclines

41
Q

Antibiotics that bind 50 S subunits of ribosomes

A

Lincosamides
Chloramphenicol
Macrolides
Clindamycin

42
Q

Aminoglycosides

A

Acts on anaerobic Gram negative bacteria

To be effective they should be used in combination with another antibiotic

43
Q

-icin Aminoglycosides:

A

Amikicin
Gentamicin
Netilmicin

44
Q

-ycin Aminoglycosides

A 
Tobramycin 
neomycin 
kanamycin 
streptomycin 
spectinomycin
45
Q

Least toxic aminoglycosides antibiotic:

A

Netilmicin

46
Q

Amikacin:

A

A semi synthetic the riveter of kanamycin
Active against gentamicin resistant gram-negative rods
Used preoperatively and post operatively to suppress microbial flora and avoid infections

47
Q

Gentamicin

A

Broad-spectrum aminoglycoside used against aerobic gram-negative and gram-positive bacteria
Taken parenterally orally or as an ointment for the eye infections

48
Q

Tobramycin

A

Activity similar to gentamicin but slightly better against Pseudomonas aeruginosa
Nowadays Pseudomonas has acquired resistance against tobramycin so it is no longer used to treat it except when it is a non-resistant strain

49
Q

Kanamycin

A

No longer in clinical use

Only used as a prophylaxis to suppress microbial flora and avoid infections

50
Q

Neomycin

A

Topical use when contaminated mucosal surfaces, too toxic to be used to systemically

51
Q

About spectinomycin:

A

Used via a single dose IM injection to treat gonorrhea caused by Beta lactamase producing gonococci.
Alternative drug to penicillin
cause pain at the site of infection nausea and fever.

52
Q

Streptomycin

A

The oldest aminoglycosides
What day is restricted for treatment of tuberculosis.
Has acquired chromosomal mediated resistance and then plasmid mediated resistance
No longer used alone but has to be combined with other drugs

53
Q

Side effects of streptomycin

A

Tinnitus
Vertigo
Ataxia

54
Q

Indications for aminoglycoside therapy

A 
Only used for severe and life-threatening infections:
Gram-negative septicemia
Bacterial endocarditis
Septicemia of unknown etiology
Post surgical abdominal sepsis
Pyelonephritis
Staphylococcus aureus septicemia
55
Q

Antibiotics acting on elongation phase of protein synthesis

A

Tetracyclines clothes on for Nicole chloramphenicol
Lyncosamids
macrolides
fusidic acid

56
Q

Members of tetracycline

A

Chlortetracycline
Deoxycycline
Oxytetracycline
Tetracycline Minocycline

57
Q

Tetracyclines are bacteriostatic or bactericidal

A

Bacteriostatic

58
Q

Tetracycline shouldn’t be prescribed for

A

Pregnant women and children under 6 years old because tetracyclines will deposit on bone and cartilage leading to formation of yellow teeth

59
Q

Chloramphenicol is bacteriostatic or bactericidal

A

Bacteriostatict

60
Q

About chloramphenicol:

A

They bind 50s subunit of ribosome by blocking amino acid attachment
It was previously used in the treatment of salmonella typhi but it had severe toxic side effects so it’s no longer used.

61
Q

How bacteria synthesize its own folic acid?

A

PABA in the presence of dehydropteroate synthase Relate formation of dehydropteroic acid then dehydrofolic acid which in the presence of dehydrofolate synthase will produce tetrahydrofolic acid.

62
Q

Antimetabolites

A

Sulfonamides
Daspone
Trimethoprim

63
Q

Bactrim composition

A

One part of trimethoprim and five parts of sulfonamides

64
Q

About Bactrim

A

It is effective against mini gram-negative and gram-positive bacteria. It can be used for urinary tract infections but can cause an overgrowth of fungi causing genital tract itching for females due to overgrowth of Candida albicans

Bacteriology F (16 decks)

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