TX & Control of Bacterial and Fungal Infections

Question 1

What are antimicrobials?

Answer 1

Substance of natural, semisynthetic or synthetic origin that destroy microbes, prevent multiplication and growth or prevent pathogenic effect

Question 2

Who discovered penicillin?

Answer 2

Alexander Fleming

Question 3

What is an antibiotic?

Answer 3

Produced by microorganism that at low concentration inhibits or kills other microorganisms

Question 4

T/F

All antibiotics are antimicrobials, but not all antimicrobials are antibiotics

Answer 4

True

Question 5

What is the mode of action of antimicrobial agents?

Answer 5

Attack DNA, ribosomes, and cell wall

Question 6

What are broad spectrum antimicrobials?

Answer 6

Active against both Gram + and Gram - organisms

Question 7

Is knowledge of the intrinsic resistance of a pathogen important?

Answer 7

Yes

Question 8

What is a bactericidal drug?

Answer 8

Antimicrobial that kills bacteria

Question 9

What is a bacteriostatic drug?

Answer 9

Antimicrobial that inhibits bacteria

Question 10

What knowledge is needed to use antimicrobial agent?

Answer 10

1. Know the drugs
2. Know the microbiology
3. Know the patient

Question 11

When do you use an antibiotic?

Answer 11

When the patient has a treatable microbial infection

Question 12

What is non-therapeutic use of antibiotics?

Answer 12

1. Growth promotion

2. Prophylactic or Metaphylactic use (prevent infection)

Question 13

What is antimicrobial susceptibility testing (AST)?

Answer 13

Lab test to determine whether bacteria is susceptible to particular antimicrobial agent

Usually performed when selecting an antimicrobial for treatment

Question 14

What two types of AST are there?

Answer 14

1. Disk diffusion test (Kirby Bauer test)

2. Broth/Agar dilution test

Question 15

What is minimum inhibitory concentration (MIC)?

Answer 15

Minimum amount of drug needed to inhibit bacterial growth

Question 16

What is a susceptibility break point?

Answer 16

Drug concentration above which organism is considered resistant

The organism is susceptible to drug at or below this value

Question 17

What are the 3 break point values?

Answer 17

1. Susceptible: Likely successful
2. Intermediate: uncertain
3. Resistant: Likely failure

Question 18

What must be used in a disk diffusion test?

Answer 18

Must use bacterial isolate in pure culture

Use published reference breakpoints

Question 19

What is a broth dilution test?

Answer 19

Add multiple dilutions of antimicrobial agents in wells

Measure MIC

Use published reference breakpoints

Question 20

Why do susceptibility testing?

Answer 20

Help Patients today, tomorrow, and in the next decade

Question 21

What is pharmacokinetics?

Answer 21

Fate of drug in body

Question 22

What is pharmacodynamics?

Answer 22

Effect of drug on the body

Question 23

Why use antimicrobial combinations?

Answer 23

1. Obtain antimicrobial synergism
2. Treat polymicrobial infections
3. Decrease emergence of antimicrobial resistance
4. Reduce drug toxicity

Question 24

What is innate resistance?

Answer 24

Pre-existing genomic property

Question 25

What is acquired resistance?

Answer 25

Acquired by mutation or horizontal gene transfer

Question 26

What are some problematic bacterial organisms?

Answer 26

1. Organisms with innate resistance
2. Vancomycin resistant Enterococcus (VRE)
3. Methicillin resistant Staphylococcus aureus (MRSA)
4. MDR & XDR Mycobacterium tuberculosis

Question 27

What are some strategies to reduce antimicrobial resistance?

Answer 27

Prudent drug use

Pathogen control

Policy