26. Antibiotic Resistance Flashcards

1
Q

What are the methods of antibiotic resistance?

A
Inactivation of enzymes
Impair permeability
Drug efflux
Target modification
Metabolic bypass
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2
Q

Name 2 examples of enzyme inactivation

A

B-lactamases
Aminoglycoside-modifying enzymes
Carbapenemase

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3
Q

What organisms produce b-lactamase?

A

Staph
Enterobacterales
EBSL

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4
Q

How can gram negative bacteria have antibiotic resistance by impairing permeability?

A

Change outer membrane porins or cell membrane transport proteins
Makes it more difficult for antibiotics to enter

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5
Q

Give an example of impaired permeability resistance?

A

Gentamicin and pseudomonas

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6
Q

What is drug efflux?

A

Bacteria makes new proteins which pump the drug out of the bacteria so it can’t reach its target

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7
Q

Give an example of drug efflux resistance

A

Tetracycline and quinolone resistance in gram -

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8
Q

What is target modification?

A

Binding site for the antimicrobial is altered

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9
Q

Give 2 examples of target modification

A

MRSA alters PBP2

Change in 30s ribosome prevents streptomycin binding

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10
Q

What is metabolic bypass?

A

Bacteria can activate different metabolic pathways

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11
Q

Give an example of metabolic bypass

A

Sulphonamids and trimethoprime usually inhibit folate synthesis

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12
Q

What are the methods of beta lactam resistance in gram + bacteria?

A

Target modification

Inactivation of enzymes

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13
Q

What are the methods of beta lactam resistance in gram - bacteria?

A

Target modification
Inactivation of enzymes
Permeability changes

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14
Q

What are the methods of resistance to aminoglycosides?

A

Aminoglycoside modifying agents

Methylation of 16s ribsomal RNA

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15
Q

What are the methods of resistance to quinolones?

A

Mutations in DNA gyrase (target modification)

Efflux pumps

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16
Q

What genes are responsible for mutations in DNA gyrase?

A

Qnr

17
Q

What are the methods of resistance in tetracyclines?

A

Drug efflux

Alteration in target site

18
Q

What is a pleiotropic mechanism of resistance?

A

Same mechanism encodes resistance to a number of antibiotic classes