Microbiology - Chapter 12: Drugs, Microbes, Host – The Elements Of Chemotherapy (Test 4)

Front 1

what are the origins of antibiotics?

Give examples;

Back 1

Antibiotics are common metabolic products of aerobic bacteria and fungi
Bacteria: Streptomyces and Bacillus
Molds: Penicillium and Cephalosporium

Front 2

Drugs should be ______ ______they kill or inhibit microbial cells without damaging host tissues

Back 2

selectively toxic

Front 3

what does the spectrum of an antibiotic mean?

Back 3

Range of different bacteria affected by Ab

Front 4

describe:
broad spectrum
narrow spectrum
limited spectrum

Back 4

BROAD SPECTRUM: kill/inhibit wide range of gram+/-NARROW SPECTRUM: kill/inhibit mainly gram+ or gram-LIMITED SPECTRUM: effective against single species

Front 5

what are the 5 fundamental mechanism of antibiotic action?

Back 5

Inhibition of cell wall synthesis
2: Inhibition of nucleic acid structure and function
3: Inhibition of folic acid synthesis (really this is a type NA inhibition)
4: Inhibition of protein synthesis
5: Interference with cell membrane structure or function

Front 6

What is the anagram for the 5 fundamental mechs of antibiotic actioN?

Back 6

Pro (protein synthesis)
Members (cell membrane)
Follow (folic acid)
New (nucleic acid)
Wallets (cell wall)

Front 7

name two antibiotic classes that react to disrupt cell wall synthesis. How?

Back 7

penicillins and cephalosporins

Block some aspect of peptidoglycan synthesis

Front 8

what is a "r"-lactam?

Back 8

penicillins and cephalosporins - Named for their four membered ring structure

Front 9

"r"-lactams cause _____ _____ ______

Back 9

cell wall destruction

Front 10

what is the spectrum of "r"-lactams?

Back 10

Some: against gram+/-, others: against either/or

Front 11

how does vancomycin work?

Back 11

Natural product. Blocks NAM cross-linking. Effective against Gram +. Made by a class of M.O. know as Actinobacteria (make some of our most useful antibiotics)

Front 12

what drug could you use against TB? Why?

Back 12

Isoniazid
Frontline TB drug. Inhibits mycolic acid production crucial for Mycobacterial sp. cell wall construction

Front 13

Why does Vancomycin primarily target Gram +?

Back 13

because it is such a huge molecule, Gram - outer membrane prohibit it from entering.

Front 14

what does Bacitracin do?

Back 14

Block peptidoglycan synthesis at early stages
blocksrecycling of bactoprenol

Front 15

what are the drugs that target the cell wall?

Back 15

"r"-lactams

bacitracin
isoniazid
vancomycin

Front 16

give an example of a class of drugs that target nucleic acid synthesis. Do they have a broad, narrow, or limited spectrum?

Back 16

fluoroquinolones

Broad

Front 17

how do drugs disrupt nucleic acid synthesis

Back 17

Block synthesis of nucleotides
Inhibit replication
Stop transcription
Inhibit DNA synthesis

Front 18

Give an example of a drug that disrupts nucleic acid synthesis. What would you use it for treating?

Back 18

ciprofloxacin

Penetrates Macrophages (good for intracellular parasites)
Has been used to treat Anthrax

Front 19

what nucleic acid targeting drug would you use to treat anaerobes which are resistant to many Ab's

Back 19

metronidazole - blocks passage of DNA polymerases, must be activated by flavodoxin, which is not found in eukarotic cells, onlin in anaerobes.

Front 20

what are some micro-orgs that you would use metronidazole to treat?

Back 20

helicobacter pylori
trichomatis vaginalis
giardia inestinalis

Front 21

what two classes of drugs target folic acid synthesis?

Back 21

sulfonamides and trimethoprim

Front 22

describe sulfonamides and what they're good for

Back 22

Sulfa drugs
Very first modern antimicrobial drug
Synthetic
Shigellosis, acute urinary tract infections, certain protozoan infections

Front 23

describe trimethoprim and what it's good for

Back 23

Inhibits the enzymatic step immediately following the step inhibited by solfonamides in the synthesis of folic acid
Often given in combination with sulfamethoxazole
One of the primary treatments for Pneumocystis (carinii) jiroveci pneumonia (PCP) in AIDS patients

Front 24

how do drugs that inhibit protein synthesis work?

Back 24

Inhibit translation by reacting with the ribosome-mRNA complex

Front 25

what is a class of drugs that target protein synthesis?

Back 25

Aminoglycoside Drugs (Streptomycin

Front 26

what could you use streptomycin for?

Back 26

Streptomycin: Bubonic plague and tularemia and good antituberculosis agent

Front 27

How does streptomycin work?

Back 27

interferes with protein synthesis

Front 28

how do aminoglycoside drugs work?

Back 28

cause mRNA to misread, protein is incorrect

Front 29

how do tetracycline drugs work?

Back 29

bind to ribosomes and block tRNA and protein synthesis

Front 30

how do chloroamphenical drugs work?

Back 30

Blocks peptide bond formation and protein synthesis

Front 31

how does erythromycin work?

Back 31

Blocks protein synthesis by attaching to the 50s ribosome prevents it from moving down the mRNA

Front 32

Name a protein synthesis blocker that can be given in 1-2 doses.

Back 32

azithromycin (Zithromax)

Front 33

what are the protein synthesis inhibiting drugs?

Back 33

aminoglycosides, tetracycline
chloramphenicol, erythromycin
clindamycin, Azithromycin, and streptogramins

Front 34

what is an example of something that will disrupt the cell membrane function?

Back 34

surfactants such as soap

Front 35

what are some drugs that disrupt cell membrane function?

Back 35

polymyxins
triclosan

Front 36

Describe the 5 steps of traditional antibiotic development

Back 36

Hypersensitive strain of bacterial plated on agar
Spot soil isolate on plate
Allow lawn of bacteria to develop
Identify zone of inhibition of growth
Isolate strain producing Ab, ID Ab structurally

Front 37

**

Back 37

**

Front 38

Describe combinatorial chemistry

Back 38

Start with core structure
Chemically modify core to make derivatives
Test derivatives against known pathogens

Front 39

Describe rational drug design

Back 39

Use known structure of target to design drugs
Apply combinatorial chemistry
Test efficacy of new combinatorial compounds

Front 40

For every Ab introduced, resistance has occurred in ______
The driving force in Ab discovery and development is _________
The 2002 Ab market was estimated at US$________!

Back 40

1-10 yrs
economic
25 billion

Front 41

Microbes become newly resistant to a drug after

Back 41

Spontaneous mutations in critical chromosomal genes
Acquisition of entire new genes or sets of genes via transfer from another species (plasmids called resistance (R) factors)

Front 42

what are some ways microbes can become resistant.

Back 42

drug inactivation-enzyme deactivates the drug
decreased permeability-microbe receptor to the drug is changed
Activation of drug pumps-pumps drug out of cell
Change in drug binding site
Use of alternate metabolic pathway.

Front 43

**

Back 43

**