Microbiology Test 3 CH10

Question 1

Drugs

Answer 1

Chemicals that affect physiology in any manner

Question 2

Chemotherapeutic Agents

Answer 2

Drugs that act against diseases

Question 3

Paul Ehrlich

Answer 3

“Magic Bullet” used trepamine (arsenic)

Question 4

Alexander Flemming

Answer 4

Found penicillin in fungus. First Antibiotic

Question 5

Gerhard Domagk

Answer 5

Sulfa (synthetic penicillin)

Question 6

Cell wall synthesis inhibitors

Answer 6

Penicillin. Interferes with the linking enzymes between NAG and NAM. Cell continues making NAG/NAM but osmotic forces will cause cell to lyse without adhesive enzyme.

Question 7

Inhibition of Cell wall synthesis

Answer 7

Act by preventing cross-linkage of NAM subunits by binding to enzymes. Beta-lactams and beta lactam rings.

Question 8

Semisynthetic beta-lactams

Answer 8

More stable in acidic environments, more readily absorbed, less susceptible to deactivation, more active against more types of bacteria.

Question 9

Vancomycin/cycloserine

Answer 9

Interfere with alanine-alanine bridges that link NAM subunits in many gram-positives.

Question 10

Bacitracin

Answer 10

Blocks secretion of NAM and NAM from cytoplasm

Question 11

Isoniazid/Ethambutol

Answer 11

Disrupt formation of arabinogalactan-mycolic acid (mycobacterium) ex. tuberculosis .

Question 12

Protein Synthesis Inhibitors

Answer 12

Prokaryotic ribosomes are 70S versuses Eukaryotic ribosomes which are 80S which allows selective drugs that target a specific ribosome. May be harmful to humans due to mitochondrial DNA.

Question 13

Disruption of cytoplasmic membranes

Answer 13

Some drugs become incorporated into cytoplasmic membrane and damage integrity.

Question 14

Amphotericin B (Polyene)

Answer 14

Attaches to ergosterol found in fungal membranes.

Question 15

Azoles and Allyamines

Answer 15

Inhibit ergosterol synthesis

Question 16

Polymyxin

Answer 16

Disrupts cytoplasmic membranes of Gram negative, but can be toxic to human kidneys

Question 17

Quinolones

Answer 17

Inhibition of metabolic pathways. Interfere with the metabolism of malaria parasites

Question 18

Heavy Metals

Answer 18

can inactivate enzymes in some of these pathways.

Question 19

Sulfonamide

Answer 19

Inhibition of Metabolic Pathways

Analogs of PABA prevent folic acid production so cell dies.

Question 20

Trimethoprim

Answer 20

Inhibition of metabolic pathways

Specifically binds to enzyme involved in conversion of dihydrofolic acid to THF

Question 21

Amantadine/rimantadine

Answer 21

Neurtralize acidity of phagolysosome and prevent viral uncoating. If virus is unable to uncoat it CANNOT replicate

Question 22

Quinolones/fluoroquinolones

Answer 22

act against prokaryotic DNA gyrase; little effect on eukaryotes or viruses since we dont use gyrase.

Question 23

Rifampin

Answer 23

Bind to and inhibit action of RNA polymerase during transcription

Question 24

Efficacy

Answer 24

Dosages required to be effective routes of administration and overall safety. Ascertained by diffusion susceptibility/ Kirby bauer method; Minimum inhibitory concentration test, Minimum bactericidal concentration test.

Question 25

Diffusion Susceptibility Test/Kirby Bauer

Answer 25

Involves disks of antibiotics placed in medium and incubated. Growth of inhibition is noted after.

Question 26

Minimum Inhibitory Concentration (MIC) Test

Answer 26

An ascending amount of antibiotics is placed into a broth medium, after incubation turbidity is noted, the first tube without turbidity is known as the minimum inhibitory concentration.

Question 27

Etest

Answer 27

Strip of with antibiotics infused in it is placed on an agar medium. The strip released antibiotics into the agar exponentially. Where the microbes begin to not grow is the MIC.

Question 28

Minimum Bactericidal Concentration Test

Answer 28

Broth from the clear (no turbidity) test tubes from the MIC test are cultured in an agar medium. The first or second tube may have some bacterial growth. The first tube to have no bacterial growth shows the bactericidal concentration.

Question 29

Inter oral (IO)

Answer 29

Simplest; lower blood drug concetration; no reliance on health care provider; patients do not always follow prescribing information

Question 30

Intramuscular

Answer 30

Requires needle for administration; concentration never as high as IV

Question 31

Intravenous

Answer 31

Drug concentration eventually diminishes as liver and kidneys remove drug from circulation

Question 32

Toxicity

Answer 32

Exact cause of many adverse reactions poorly understood Drugs may be toxic to kidneys, liver or nerves Consideration when prescribing drugs to pregnant women

Question 33

Allergies

Answer 33

May be life threatening with anaphylactic shock

Question 34

Disruption of normal microbiota

Answer 34

May result in secondary infection | Overgrowth of normal flora (Superinfection)