Antimicrobial Compounds

Question 1

What is the beta-lactam ring?

Answer 1

Central component of all betalactam antibiotics
This includes penicillin, amoxicillin, etc
They inhibit cell wall synthesis

Question 2

Narrow vs Broad

Answer 2

Carbapenems are broad, most activity, don’t like using them though because they are a last line drug
Narrow is good-only targets specific bacteria and does not kill off all normal flora(Ampicillin)

Question 3

What are glycopeptides?

Answer 3

Non-Beta-Lactam cell wall active agents
act on gram positive organisms
Stop the extension of the peptidoglycan unit of the bacterial cell wall
Vancomycin

Question 4

What are protein synthesis inhibitors?

Answer 4

They stop protein synthesis in bacteria (the protein is very important for the bacteria to work)

Question 5

What are some protein synthesis inhibitors?

Answer 5

Tetracyclines
Macrolides
Chloramphenicol

Question 6

What are nucleic acid inhibitors

Answer 6

Fluoroquinolones-prevents DNA gyrase or DNA topoisomerase
So then bacteria can’t synthesize proteins

Question 7

What is a metabolic inhibitor?

Answer 7

A metabolic inhibitor stops the bacteria from gaining access to specific things it needs, this inhibits protein synthesis for them to survive

Question 8

What are the 2 types of resistance?

Answer 8

Intrinsic resistance-you don’t have to do anything for this, it is a natural phenomenon associated with the bacteria (genes that are in the chromosomes of this bacteria)
Inducible/acquired resistance-you can carry it and give it to people, but you have to get it-not in genes

Question 9

How do we test for resistance?

Answer 9

Done in vitro (glass), we translate this to see if it will be effective in patients.

Question 10

R vs S vs I

Answer 10

R is resitant-organism grows with antibiotic
S is sensitive-organism does not grow

Question 11

What is the zone of inhibition

Answer 11

Measured in mm
Shows the bacteria’s susceptibility with antibiotics

Question 12

What is MIC

Answer 12

minimum inhibitory concentration
meaning it is the lowest concentration of antibiotics that there is a lack of growth of bacteria

Question 13

How is bacterial resistance a thing?

Answer 13

It is inherited or aquired
Efflux pumps
Reduced permeability
Enzymatic inactivation
Altered binding site

Question 14

Efflex pump?

Answer 14

How bacteria develops resistance to antibiotics
the bacteria makes thousands of pumps that just pump the antibiotic back out (can’t be shared)

Question 15

Reduced permeability

Answer 15

Changes the cell wall’s thickness or the size of pores (antibiotic can’t get in now) can’t be shared

Question 16

Enzymatic inactivation?

Answer 16

bacteria makes an enzyme that breaks down antibiotics (this one can be shared among other bacteria) (worrisome)

Question 17

Altered binding site

Answer 17

The antibiotic typically has a specfic binding site, that changes on the bacteria so now it can’t bind

Question 18

How do bacteria share their resistance mechanisms?

Answer 18

Conjugation-build a bridge and share genetic info
Transduction-virus carries resistance gene and infects bacteria
Transformation-A bacteria grows and produces a toxin to kill antibiotics (basically get’s this DNA from environment and makes it their own)

Question 19

How does bacteria maintain resistance?

Answer 19

They have a metabolic cost=energy use

Question 20

What is antibiotic selective pressure?

Answer 20

overuse of antibiotics are a major reason
Not completing a prescription=bacteria becomes resistant
Animal feeds use antibiotics
Using someone else’s prescription

Question 21

What are Antibiotics target sites?

Answer 21

Inhibition of cell wall synthesis
Inhibition of protein synthesis
Inhibition of essential metabolites
Injury to plasma membrane

Question 22

What is the most resistant organism?

Answer 22

MRSA is on top
Vancomycin enterococcus is high up on the list