2/28/17 Antibiotic Resistance MULVEY TEST #2

Question 1

What are antibiotics synthesized by?

Answer 1

• Molds

- Bacteria

Question 2

Who discovered penicillin?

Answer 2

-Alexander Flemming

Question 3

How many lives do antibiotics save a year?

Answer 3

200,000 +

Question 4

What are the major antibiotic targets?

Answer 4

• Cell wall
• DNA replication
• RNA synthesis
• Protein synthesis
• Folic acid synthesis

Question 5

How does antibiotic resistance happen?

Answer 5

-The drug resistant forms don’t die from the antibiotics but the others do allowing the drug resistant forms to grow in the new open space.

Question 6

What is bacterial resistance facilitated by?

Answer 6

• Chance
• Horizontal gene transfer
• Strong selective pressures from increased use and misuse of antibiotics

Question 7

There are several antimicrobial resistance mechanisms today, which one is when a drug can’t get in or the drug gets in but gets pumped back out before affecting the target?

Answer 7

-Restrict antibiotic access

Question 8

There are several antimicrobial resistance mechanisms , which one is when the target is altered structurally or the target is over expressed, and needs much more drug?

Answer 8

-Modify antibiotic targets

Question 9

What are the four antimicrobial resistant mechanisms?

Answer 9

• Restrict antibiotic access
• Modify antibiotic target
• Modification of the antibiotic
• Modify expression of bacterial factors needed to active the antibiotic

Question 10

If you have a mutation in 23S rRNA that protects the bacteria against macrolides such as erythromycin what resistant mechanism is that?

Answer 10

-Modify antibiotic target

Question 11

What does vancomycin bind to, to be effective?

Answer 11

-The terminal D-Ala D-Ala on the protein

Question 12

For Vancomycin resistance what happens with the D-Ala D-Ala region?

Answer 12

-The second D-Ala gets changed so that Vancomycin can’t bind there anymore

Question 13

If the transpeptidase is altered so that penicillin can no longer bind to inhibit the transpeptidase, what is the resistant mechanism?

Answer 13

-Modify antibiotic target

Question 14

When you have B-lactamase that destroys the B-lactam ring what resistant mechanism is that?

Answer 14

-Modification of the antibiotic

Question 15

When you have modifications that disrupt the hydrogen-bonding network that is used from the antibiotic that is used to bind the 16S rRNA what is the resistant mechanism?

Answer 15

-Modification of the antibiotic

Question 16

Metronidazole activation is done by what?

Answer 16

-Flavodoxin found in H. pylori and P. gingivalis

Question 17

What are two drugs that bacteria have become resistant to through the mechanism of resistance by modifying expression of bacterial factors needed to activate that antibiotic?

Answer 17

• Metronidazole

- Isoniazid

Question 18

What is Isoniazid activated by?

Answer 18

-Bacterial catalase/peroxodase enzyme KatG in MTb

Question 19

T/F Resistance is acquired by mutation and by Horizontal Gene Transfer

Answer 19

True

Question 20

T/F Overuse of antibiotics, overpopulation, poor hygiene and travel contribute to the selection and spread of multi-drug resistant strains.

Answer 20

True

Question 21

What are four multi drug resistant bacterial pathogens?

Answer 21

-Extended-spectrum B-lactamase producing enterobacteriaceae
=Cabapenem-Resistant Enterobacteriacea
-C. diff
-Super N. gonorrhea

Question 22

What are four reasons that antibiotic tolerance is important?

Answer 22

• Within intracellular niches
• Spores
• Within biofilms
• Persister cell formation

Question 23

T/F Antibiotic tolerance contributes to chronic and recurrent/relapsing infections (recrudescence)

Answer 23

True

Question 24

T/F Bacteria that are normally susceptible to antibiotics may be able to tolerate the drugs under some conditions

Answer 24

True

Question 25

What are dormant bacteria that are insensitive to many stresses and antibiotic treatments called?

Answer 25

-Persister cells