Mechanisms of Microbial Resistance Flashcards Preview

Infectious Disease and Medical Microbiology > Mechanisms of Microbial Resistance > Flashcards

Flashcards in Mechanisms of Microbial Resistance Deck (15)
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0

What are three ways bacteria can acquire genetic material?

-Transformation: Transfer of free DNA of resistant DNA from dead bacteria
-Conjugation: Plasmid transfer from another live bacteria
-Transduction: viral DNA inserted

1

What are the 5 targets of antimicrobial therapy?

-Folate metabolism
-Nucleic acid synthesis
-Protein synthesis
-Cell membrane
-Cell wall synthesis

2

What are the 5 mechanisms of antimicrobial action?

-Inhibit folate metabolism
-Inhibit DNA synthesis
-Inhibit protein synthesis
-Disrupt cell membrane
-Inhibit cell wall formation

3

Which drugs inhibit folate metabolism? (2)

Trimethoprim and sulfonamides
Nitrofurantoin

4

What drugs inhibit DNA synthesis? (2)

Quinolones and metronidazole

5

What drugs inhibit protein synthesis in bacteria? (5)

-Aminoglycosides
-Tetracyclines
-Macrolides (e.g. Erythromycin and Azithromycin)
-Clindamycin
-Linezolid

6

What drugs disrupt the bacterial cell membrane? (3)

-polymixins
-colistin
-daptomycin

7

What drugs inhibit bacterial cell wall synthesis? (4)

-Beta lactams: penicillins, cephalosporins, carbapenems
-Vancomycin

8

What are the 5 mechanisms of microbial resistance?

-Altered target
-Bypass metabolic pathway
-Antibiotic inactivation
-Decreased influx
-Increased efflux

9

What is an example the altered target mechanism of resistance? (5)

-penicillin binding protein enzyme
-ribosome subunit
-DNA gyrase/topoisomerase IV
-Peptidoglycan precursor
-DHPS/DHFR enzyme

10

What is an example of bypassing a metabolic pathway in microbial resistance?

Enterococcus scavenging exogenous folate

11

What is an example of antibiotic inactivation? (2)

-Beta lactamases
-aminoglycoside modifying enzymes

12

What is an example of a mechanism of decreased antibiotic influx?

P. aeruginosa has decreased production of OprD (carbapenem channel)

13

What is an example of increased drug efflux in microbial resistance?

-Multidrug pump: Mex-OPR in P. aeruginosa
-Single drug pumps: tet(tetracyclines), mef(macrolides), NorA(quinolones)

14

What are two situations where antimicrobial resistance can be generated?

-Mutation selects for bacteria that are resistant against the antibiotic
-Genes can be transferred from a resistant bacteria