Micro control in body

Question 2

Importance of normal microflora

Answer 2

they inhibit binding of pathogens, decrease nutrient availability, actively kill pathogens, stimulate our immune system

Question 3

“Magic Bullet”

Answer 3

ideal antibiotic. Paul Ehrlich.

Question 4

Methods of action of antimicrobials

Answer 4

Inhibit cell wall, protein, plasma membrane, metabolic pathways, DNA or RNA, attachment to host

Question 5

Inhibit cell wall synthesis

Answer 5

Penicillin blocks NAG and NAM crosslinking, so cell wall will burst in because they have no wall. Only effective if cell is dividing

Question 6

Inhibit protein synthesis

Answer 6

Block binding of 30S of 50S subunit, stop a.a. coming in, inhibit elongation

Question 7

Disrupt cytoplasmic membrane

Answer 7

For fungi (eukaryotes); attaches to unique sterols in membrane and makes pores

Question 8

Inhibit metabolic pathways

Answer 8

inhibit enzymes; best is noncompetitive

Question 9

Ideal antimicrobial agent

Answer 9

Readily available (easy to make or isolate), Inexpensive, Chemically stable, Easily administered, Nontoxic and nonallergenic, Selectively toxic against wide range of pathogens (and not to humans)

Question 10

Evaluation

Answer 10

Spectrum of action (target), Efficacy, Bioavailability, side effects, selective toxicity

Question 11

Efficacy of antimicrobial

Answer 11

Dosage(s) required, route of administration, overall safety

Question 12

Problem with minimum inhibitory concentration test and solution

Answer 12

Don’t know if it’s bacteriostatic or bactericidal; run a minimum bactericidal concentration test: plate a clear MIC tube to see CFUs

Question 13

Septocemia and solution

Answer 13

Causes huge inflammatory response in the blood. Requires high level of antibiotic immediately

Question 14

Side effects of antibiotics

Answer 14

Toxicity (of it or of metabolites), Allergies, Disruption of normal microbiota

Question 15

Toxicity of antibiotics

Answer 15

Causes not well understood; genetics; some are toxic to nerves, liver, or kidneys; considerations for pregnant women; combination of meds

Question 16

Allergic reactions to antibiotics

Answer 16

Some are not allergic but are produced by something else

Question 17

Disruption of Normal microbiota

Answer 17

Can cause secondary infection; if pathogens overtake normal microbiota can cause superinfections; concern in hospitals

Question 18

Development of Resistant Organisms

Answer 18

Acquired by mutation of their own DNA, plasmids, or horizontal gene transfer (transduction, transformation, conjugation)

Question 19

Mechanisms of resistance to antibiotics

Answer 19

Production of enzymes (inactivate it), Slow or prevent entry of the drug (but DNA leaks from dying cells), Alter the receptor for the drug, Alter metabolic chemistry, Multi-drug efflux pumps

Question 20

Satellite colonies

Answer 20

Colonies that grow near a colony that secretes enzymes against an antibiotic - they are saved

Question 21

What can occur with the constant use of drugs?

Answer 21

it kills all the sensitive cells, but selects for superbugs (mutate frequently/insensitive), cross resistance (horizontal gene transfer)

Question 22

Retarding resistance

Answer 22

High [ ] for a long enough time, new variations of drugs, not too many antimicrobials, combination therapies