Brainscape's Knowledge GenomeTM

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


See full index

Pathology Summaries > MICRO: Antimicrobials > Flashcards

MICRO: Antimicrobials Flashcards

1
Q

Name 2 types of bonds in bacterial cell walls which give rigidity and protect from lysis.

A

Glycosidic bonds
Peptide bond

These are formed between NAM and NAG.

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

What are transpeptidases?

A

Penicillin binding proteins = involved in terminal stages of cell wall synthesis

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

What is the MOA of beta lactams?(2)

A

Inhibit transpeptidases
Structural analogues of the enzyme substrate needed

–> bactericidal

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

What is the MOA of glycopeptides?

A

Stop transpeptidase binding so it cannot form peptide bonds
Stop transglycosidase so no glycosidic bonds form

–> slowly bactericidal

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

What is the MOA of aminoglyosides?(2)

A

At 30s to prevent ELONGATION of polypeptide chain

At mRNA to cause MISREADING of codons

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

What is the MOA of tetracyclines?

A

At 30s they reversibly bind and prevent tRNA binding to ACCEPTOR site, inhibiting protein synthesis.

–> bacteriostatic

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

What is the MOA of macrolides?(2)

A

At 50s they bind and stop TRANSLATION

They also stimulate DISSOCIATION of tRNA so inhibit protein synthesis

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

What is the MOA of chloramphenicol?

A

At 50s it binds to peptidyl transferase to inhibit formation of PEPTIDE BONDS during translation

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

What is the MOA of oxazolidinones?

A

At 23s of 50s subunit to prevent formation of 70s INITIATION COMPLEX (required for translation)

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

What is the MOA of quinolones?

A

Act at alpha-subunit of DNA gyrase

–> bactericidal

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

What is the MOA of nitromidazole? (e.g. metronidazole)

A

–>rapidly bactericidal

Produce an active intermediate in anaerobic conditions which causes DNA strand breakage

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

What is the MOA of rifamycins?

A

Bind RNA polymerase which inhibits initiation of protein synthesis

–> bactericidal

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

What is the MOA of daptomycin?

A

Cyclic lipopetide

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

What is the MOA of colistin?

A

Polymyxin that destroys the outer cell membrane of gram -ve organisms

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

What is the MOA of sulfonamides/ diaminopyrimidines?

A

Interfere with folic acid metabolism –> acts on DNA

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

What is the use of tazobactam in tazocin?

A

Prevents BL breakdown of piperacillin

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

Which penicillin combo can be used for E coli?

A

Co-amoxiclav a.k.a. augmentin

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

Which penicillin is stable to BL?

A

Flucloxacillin

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

Which penicillin is used for HAI and pseudomonas?

A

Piperacillin

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

Which penicillins are broken down by BLs?

A

Penicillin, Amoxicillin, Piperacillin

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

Name a first, second, third gen cephalosporin. What is the trend?

A

CePHALexin - 1st
CeFURoxime -2nd
CefoTAXime - 3rd
Increasing activity against gram -ve bacilli

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

Which cephalosporin is assoc with C diff?

A

Ceftriaxone

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

Which cephalosporin is similar to amox but stable against BL?

A

CeFURoxime - but less stable against anaerobes

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

Which cephalosporin is good for pseudomonas?

A

CefTAZidime

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

What are the only beta lactam group stable to ESBLs?

A

Carbapenems

26
Q

What is an advantage of carbapenems?

A

Very broad spectrum

27
Q

What is a disadvantage of carbapenems ?

A

Klebsiella/Acinetobacter resistance

28
Q

Why are beta lactams used in meningitis?

A

Cross BBB when inflammed

29
Q

How are beta lactams excreted?

A

Renally

30
Q

Which organisms are glycopeptides used for?

A

Gram +ve (can’t penetrate wall of gram -ves)

31
Q

Name 2 uses of glycopeptides.

A

MRSA and C diff

32
Q

What is the C in MLSCOAT of antibiotics which inhibit DNA?

A

Chloramphenicol

33
Q

Which group is clindamycin?

A

Lincosamines

34
Q

Which group is gentamicin?

A

Aminoglycoside

35
Q

Which group is erythromycin?

A

Macrolide

36
Q

What are 2 complications of aminoglycosides?

A

Nephrotoxicity and ototoxicity

37
Q

What is a disadvantage of aminoglycosides?

A

Not good for abscesses as they are inactivated at low pH

Gentamicin not active against anaerobes

38
Q

Which MLSCOAT are good for pseudomonas?

A

Gentamicin/tobramycin (aminoglycosides)

39
Q

Which MLSCOAT are good for intracellular pathogens?

A

Tetracyclines (chlamydia, rickettsiae, mycoplasma)

40
Q

Which MLSCOAT is active against MDR?

A

Tigecycline

41
Q

What is a complication of tetracyclines?

A

Deposit in bone and discolour teeth . May also cause light sensitive rash

42
Q

List 2 uses of macrolides.

A

Staph/strep in pen allergic

Atypical pneumonia e.g. legionella, mycoplasma

43
Q

What are macrolides not effective against ?

A

Minimal activity against gram -ve (although newer ones like azithromycin can be used for Salmonella/bronchiectasis in CF)

44
Q

Why are macrolides and penicillins combined e.g. in strep pyogenes?

A

Stationary phase will not be affected by beta lactams alone but macrolides will stop toxin production here

45
Q

What are 2 complications of chloramphenicol?

A

Aplastic anaemia

Grey baby syndrome

46
Q

What is a specific use of chloramphenicol?

A

Pen allergic meningitis or CAP

47
Q

What are 2 infections which can be treated with oxazolidinones?

A

VRE
MRSA
(not gram -ves)

48
Q

What are 2 complications of oxazolidinones?

A

Thrombocytopenia

Optic neuritis

49
Q

What class if ciprofloxacin?

A

Fluoroquinolone

50
Q

Name 3 fluoroquinolones in order of gram +ve –> gram -ve activity.

A

Moxi
Levo
Cipro

-floxacin

51
Q

Which fluoroquinolone can be used for pseudomonas?

A

Ciprofloxacin - fluoroquinolones have broad activity

52
Q

What are 2 complications of fluoroquinolones?

A

Tendonitis

C diff

53
Q

Name a nitromidazole used for UTI.

A

Nitrofurantoin

54
Q

What organisms do nitromidazoles act against?

A

Anaerobic bacteria

Protozoa

55
Q

Which antimicrobials inhibit RNA synthesis?

A

Rifamycins

56
Q

What is a disadvantage of rifamycins?

A

Resistance (altered target single aa) develops quickly so never use alone

57
Q

Apart from TB, what other conditions is rifamycin used to treat?

A

Prosthetic joint
Endocarditis

(disrupts biofilms)

58
Q

Is daptomycin only against gram +ve or -ve?

A

GRAM +VE ONLY e.g. MRSA, VRE

59
Q

Is colistin used against gram +ve or -ve? Name 3 organisms.

A

Gram -ve e.g. pseudomonas, acinetobacter, klebsiella

60
Q

Name 2 inhibitors of folate metabolism.

A

Sulfonamide

Diaminopyrimidines (trimethoprim - but 40% E coli are resistant)

61
Q

Name a combination use of a sulfonamide.

A

Sulphamethoxazole + trimethoprim = CO-TRIMOXAZOLE

62
Q

What is good about sulfonamides?

A

Very broad spectrum

Pathology Summaries (23 decks)

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