Drug Resistance pt 1

Question 1

What is intrinsic antibiotic resistance?

Answer 1

Microbe that has natural resistance to antibiotic

(lack cell walls, endospores)

Question 2

What is acquired antibiotic resistance?

Answer 2

Microbe gains resistance to antibiotic it was previously susceptible to.

Question 3

What are the types of acquired antibiotic resistance?

Answer 3

1. Spontaneous mutation of chromosome
2. Horizontal gene transfer

Question 4

What are the methods of horizontal gene transfer?

Answer 4

1. Conjugation
2. Transformation
3. Transduction

Question 5

What is conjugation of acquired resistance?

(How does it work)

Answer 5

• Bacteria with resistant plasmid gene
• connects to susceptible bacteria by pilus
• Transfers plasmid

Question 6

Are plasmid genes acquired by conjugation incorporated in chromosome?

Answer 6

NO

But daughter bacteria will have resistant plasmid

Question 7

How does acquired resistance by transformation happen?

Answer 7

• Bacteria with resistant chromosomal gene lyses
• DNA goes into environment
• Another bacteria takes resistance gene and incorporates it

Question 8

How does acquired resistance by transduction happen?

Answer 8

• Bacteriaphage infects resistant bacteria
• Takes resistant gene
• Bacteriaphage infects another bacteria and incorporates gene

Question 9

How does this drug resistance mechanism work:

Enzyme that breakdown antibiotic

Answer 9

Microbe acquires gene that encode enzymes to inactivate drugs

Question 10

What type of mechanism is this:

Beta-lactamase made by bacteria destroy the beta lactam ring of penicillin/cephalosporin.

Answer 10

Enzyme that break down antibiotic

Question 11

How does this drug resistance mechanism work:

Enzyme that alters antibiotic

Answer 11

Secreted enzyme chemically alter antibiotic

Question 12

What mechanism is this:

Chlorampehnicol is inactivated when bacteria add acetyl group to it.

Answer 12

Enzyme that alters bacteria

Question 13

How does this drug resistance mechanism work:

Reduced drug uptake

Answer 13

• Amino acid mutation that changes receptor
• Drugs cannot bind receptor and enter

Question 14

What type of mechanism is this:

Point mutation in outer membrane transport proteins causes bacterial resistance to aminoglycosides.

Answer 14

Reduced drug uptake

Question 15

How does this drug resistance mechanism work:

Drug eliminated

Answer 15

• Bacteria have multidrug resistant pumps in cell membrane
• Active transport antibiotics out

Question 16

How does this drug resistance mechanism work:

Binding site reduced/eliminated

Answer 16

Mutation alters the structure of bacteria that is target of bacteria.

Question 17

What is this mechanism:

S. aureus become resistant to methicillin due to alteration in cell wall.

Answer 17

Binding site reduced/eliminated

Question 18

How does this drug resistance mechanism work:

Metabolic pathway turned off

Answer 18

Bacteria turn off/use alternate pathway for metabolism that antibiotic inhibits.

Question 19

What is this mechanism:

Bacteria use different pathway to produce folic acid when Sulfonamide blocks pathway.

Answer 19

Metabolic pathway turned off

Question 20

How can antibiotics increase natural drug resistance?

Answer 20

• Naturally drug resistant microbes usually found in population.
• Usually in check by non-drug resistant
• When non-drug resistant killed off, can grow unchecked

Question 21

How can antibiotics be harmful to your microbiome?

Answer 21

Kill off “good” bacteria that keep pathogenic bacteria in check

Question 22

What causes viral resistance to occur?

Answer 22

Small genetic changes as virus replicates.

1. Spontaneously
2. During antiviral treatment

Question 23

Why do most fungal drug resistances happen?

Answer 23

Antifungal use:

• Too little of a dose
• Not long enough in duration

Question 24

How can fungi develop resistance?

Answer 24

• Mutates so antifungal does not recognize
• Use alternate metablic pathway drug targets

Question 25

Where can biofilms form?

What makes them so harmful to treatment?

Answer 25

On any natural/implanted device

100x more resistant than unattached microbe