Antibiotic Resistance

Front 1

Resistance

Back 1

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Front 2

Where can resistant genes occur in bacteria (2)?

Back 2

1. chromosome
2. Plasmid (circular DNA separate from chromosome)

Front 3

How can resistance occur? (4)

Back 3

1. mutation
2. transposon -- insertion elements that hop on/off chromosome
3. Transformation -- DNA takes up from environment
4. Transduction -- phage virus cause lysis of bacteria → virus picks up virus → deposits new DNA to next bacteria

Front 4

What are the general resistance mechanisms against drugs that bacteria can develop (5)?

Back 4

1. ↓ Permeability → prevent drug from reaching site
2. ↓ import or ↑ export → prevent drug from reaching site
3. Target is altered (i.e: methylation)→ prevent binding of drug
4. Destroy or inactivate antibiotic
5. Alternative metabolic pathway (i.e: Bacteria ↑ PABA to compete against sulfonamide, which is a PABA antimetabolite)

Front 5

How does resistance develop against each drug? General resistance mechanism?

Back 5

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Front 6

B-lactam (4 - ex)

Back 6

1. B-Lactamases-- destroy antibiotic -- S. Aureus
2. Mt in Porins -- ↓ permeability -- Pseudomonas Aeruginosa
3. ↑ Efflux pumps --export -- Pseudomonas Aeruginosa
4. Altered penicillin binding proteins -- target altered -- Streptococcus Pneumonia

Front 7

Vancomycin (1- ex)

Back 7

D-ala-D-ala → D-ala- D-lac -- Target altered -- enterococci (VRE) & S. aureus (VRSA)

Front 8

Macrolide (4- ex’s)

Back 8

1. Methylated ribosome -- Target altered -- Streptococcus & Staphylococcus
2. ↑ efflux pumps -- export -- Streptococcus pneumonia
3. rRNA pt mt -- Target altered
4. Ribosomal protein modification -- Target altered -- Streptococcus Pneumoniae

Front 9

Aminoglycoside

Back 9

transferase enzyme inactivates drug by acetylation, phosphorylation, adenylation -- inactivated antibiotic

Front 10

Phenicol

Back 10

acetyl-transferase enzyme inactivates drug -- inactivated antibiotic

Front 11

Tetracycline

Back 11

↑ efflux pumps -- export

Front 12

Quinolones (2 - ex)

Back 12

1. Mt in topoisomerase -- altered target -- Pseudomonas Aeruginosa
2. ↑ efflux -- export -- S. Aureus & S. Pneumoniae

Front 13

Rifamycin

Back 13

mt in RNAp -- Target altered

Front 14

Possible Drug resistance in each of bacteria

Back 14

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Front 15

Staphylococcus (4)

Back 15

B- lactam -- B-lactamase
2. Vancomycin -- D-ala-D-lac mt
3. Macrolide -- methylated ribosome
4. Quinolone -- ↑ efflux

Front 16

Streptococcus (3)

Back 16

1. B-lactam -- altered pbp
2. Macrolide -- methylated ribosome, ↑ efflux pumps, & Ribosomal protein modification
3. Quinolones -- ↑ efflux

Front 17

Enterococcus (1)

Back 17

Vancomycin -- D-ala-D-ala → D-ala-D-lac

Front 18

Pseudomonas Aeruginosa (2)

Back 18

1. B-lactam -- Mt in porins & ↑ efflux pumps
2. Quinolones -- mt in topoisomerase