Week 13- Antimicrobial drugs

Question 1

Differentiate between an antimicrobial drug/agent and a true “antibiotic”

Answer 1

Drug/agent– will treat an infectious disease

true antibiotic— is produced naturally by an organism

Question 2

Which Genus of bacteria produces many of the antibiotics that humans use?

Answer 2

Streptomyces

Question 3

What are semisynthetic antimicrobial drugs?

Answer 3

Started with an antibiotic , but then you chemically modify the antibiotic in a lab

Question 4

What are synthetic antimicrobial drugs?

Answer 4

completely produced in lab

Question 5

Describe selective toxicity of an antimicrobial agent

Answer 5

selectively will try to target/ kill a microorganism

will also not destroy human cells

Question 6

Briefly DESCRIBE the six main mechanisms of antimicrobial. This is asking –
what are the ways that an antimicrobial drug will try to kill a microorganism?

Answer 6

1-Inhibits formation of cell wall

2-Inhibiting protein synthesis

3-destruction of cell membrane

4-inhibit metabolic pathway

5-inhibit synthesis of dna/rna

6-prevent a mo from attaching/entering cell

Question 7

Why do antibacterial drugs make up the largest number of antimicrobial drugs?

Answer 7

easier to target prokaryotic cells

because they are not like human cells

Question 8

Why are there fewer drugs to treat eukaryotic infections (ie protozoa and fungal)?

Answer 8

are similar to human cells

so can only make some that aren’t toxic to humans

Question 9

Why do antivirals make up the smallest percentage of antimicrobial drugs?

Answer 9

because virus’s enter a blood cell

so you need to target before it enters cells

mainly effective 48 hours before symptoms

Question 10

Define spectrum of action

Answer 10

Number of different pathogens a drug acts against

Question 11

narrow spectrum antimicrobials

Answer 11

Kills fewer types of MO

Question 12

broad-spectrum antimicrobials

Answer 12

Kill more groups/types then narrow

safer option to give because it kills more

Question 13

Explain the difference between a “susceptible” microbe and a resistant microbe to a specific antimicrobial drug

Answer 13

susceptible- it is killed by the drug

resistant-drug does not kill MO

Question 14

Describe the “Antimicrobial Susceptibility
Test.”

Answer 14

Place a disk on the streaked plate

disk will either make a ring or won’t-if it makes a ring, you measure it

the rings will be labeled as susceptible, intermediate, or resistant based on comparison size of zones

Question 15

What is the clinical significance of resistant microorganisms?

Answer 15

If it has a lot of resistance to many drugs, it can cause problems because you will need to keep making more and more drugs until you can eventually kill it

takes a long time

Question 16

Describe the 3 general side effects (safety issues) of antimicrobial agents— include examples

Answer 16

1-allergies-rash or anaphaptic shock

2-disruption of normal flora- gi symptoms, nausea, upset stomach, diarrhea

3-toxicity to organs-liver, brain & kidneys

Question 17

Describe 2 general ways resistance in bacteria is acquired by the microorganism (genetically)

Answer 17

Plasmid- Resistance plasmid- resistant to antimicrobial drug

Chromosomes- mutatuions that will help MOnot be killed by drugs

Question 18

Briefly describe first 5 types of mechanisms microorganisms are able to use to be resistant to antimicrobials (p. 300 text book)—Mechanisms of Resistance
(what are the ways the microorganisms are NOT allowing the drug to work)

Answer 18

1-MO will create an enzyme that can breakdown drug

2-Prevents/slows down entry of drug

3-Alter the target

4-Alter metabolic chemistry

5-Will pump the drug out

Question 19

Describe the ways that resistance to antimicrobial drugs can be prevented?

Answer 19

1-only take a specific drug when it is necessary(have MO in you)

2-Drug needs to be taken for the entire time

3- two antimicrobial drugs at one time

4-modifying or making new drugs

Question 20

What are some common “resistant” microorganisms?

Answer 20

MRSA

VRSA

VRE