Micro Midterm 2

Front 1

chemotherapeutic agent

Back 1

chemical substance used for treating or preventing disease

Front 2

what are the desired qualities of a chemotherapeutic agent

Back 2

selective toxicity
chemical needs to be able to penetrate cells and tissues of the host
-does not alter host's defense mechanism

Front 3

characteristics of an ideal antibiotic

Back 3

1. able to destroy or inhibit specific pathogenic microorganisms
2. broad spectrum
3. should not cause development of resistant forms
4. should not produce undesirable side effects
5. should be able to be given orally and not inactivated by stomach acids
7. should ahve a high level of solubility in body fluids

Front 4

penicillins

Back 4

-act by inhibiting formation of the bacteria cell wall
-contain a beta lactamase ring
-natural and semisynthetic

Front 5

natural penicillins

Back 5

-gram pos and some gram neg cocci
-penicillin g and v
-inactivated by stomach acids, heat and penicillinase

Front 6

semisynthetic penicillins

Back 6

-core compound is produced by fungi
-methicillin and ampicillin

Front 7

what are some common problems with penicillins

Back 7

-resistance by bacteria that can produce penicillinase
-allergic reactions
-gi distress and diarrhea

Front 8

cephalosporins

Back 8

produced by marine fungus, Cephalosporius acremonium
-resistant to penicillinase
-inhibits the synthesis of bacterial cell wall
-broad spectrum

Front 9

problems with cephalosporins

Back 9

if taken orally, may cause gi upset
-super infections from resistant organisms may occur
-some small allergic reactions

Front 10

streptomycin

Back 10

interferes with protein synthesis
-effective against mycobacterium
-broad spectrium
-toxic with prolonged use

Front 11

3 types of aminoglycosides

Back 11

1. neomycin-poorly absorbed orally
-used in lotions and ointments for skin and eye infections
2. kanamycin-broad spectrum
3. gentamycin-effective against Pseudomonas and may be used to treat other infections

Front 12

tetracyclines

Back 12

produced by streptomyces species
-inhibit protein synthesis
-broad spectrum

Front 13

what are some problems caused by tetracyclines

Back 13

gi problems
allergic reactins
tooth discoloration
blood and kidney problems
normal flora affected

Front 14

erythromycin

Back 14

produced by streptomyces erythreus
-prevents normal protein synthesis
-erffective against most gram pos and some gram neg bacteria

Front 15

chloramphenicol

Back 15

interferes with protein synthesis
-broad spectrum
-not to be used in food animals and only used in humans in life threatening situations

Front 16

problems with chloramphenicol

Back 16

gi irritation
anemia
neurotoxic

Front 17

polymyxin

Back 17

produced by Bacillus polymyxa
-damages cell membranes
-effective against many gram neg
-toxic if given orally

Front 18

problems with polymyxin

Back 18

gi distrss
kideny/nerve toxicity
superinfection with gram pos bacteria

Front 19

resistance to antimicrobics may be:

Back 19

naturally occurring
-change in uptake of cell
-altered structural target for the drug within the cell
-ability of the organism to produce an enzyme

acquired-
-mutation
-transfer of genetic info

may be created
-selection of resistant strains by elimination of the sensitive ones

Front 20

steps to limit the development of resistance

Back 20

1. avoid indiscriminate use
2. avoid use of antimicrobics commonly used for generalized infection
3. use correct dose
4. use combinations that are proven effective
5. use a different antimicrobic when the microbe appears to be developing resistance

Front 21

chemotherapeutic effectiveness

Back 21

antimicrobic susceptibility testing
or
sensitivity testing

Front 22

what are some chemotherapeutic effectiveness test methods

Back 22

1. tube dilution technique
2.agar plate dilutions
3. paper disk plate method

Front 23

describe the tube dilution technique

Back 23

test various dilutions of the antimicrobic with cultures(evidence of turbidity)
*minimum inhibitory concentration(MIC)
*minimum killing concentration

Front 24

minimum inhibitory concentration

Back 24

smallest amount of agent required to inhibit the growth

Front 25

minimum killing concentraion

Back 25

smallest amount of the agent required to kill the bacteria

Front 26

agar plate dilutions

Back 26

similar to tube dilutions
-agar containing a certain dilution of an antimicrobic is allowed to solidify in a plate
-drops of different bacteria are allowed to grow on the plate
-plates are examined for growth/no growth

Front 27

paper disk plate method

Back 27

agar is inoculated by swabbing the surface of the medium with the organism to be tested
-disks containing a certain concentration of the antimicrobic are pressed into agar surface and diffuses into the agar
-kirby bauer method

Front 28

kirby bauer method

Back 28

mueller hinton agar
-antimicrobic disks
-agar has a very low concentration of inhibitors of tetracyclines and sulphonamides
-must be no more than 4 days old

Front 29

what are some other uses for antimicrobics

Back 29

1. growth stimulants
2. selective media
3. culture identification
4. control of some plant disease

Front 30

bacitracin

Back 30

produced by bacillus subtilis
-highly toxic
-inhibits the synthesis of cell wall
-narrow spectrum (gram positive)
-acts against the kidney

Front 31

lincomycin

Back 31

produced by streptomyces lincolnensis
-interferes with protein synthesis
-effective againts gram pos and some gram neg
-causes diarrhea and colitis

Front 32

nystatin

Back 32

antifungal
-acts on cell membrane and impairs its function
-effective against yeasts and other fungi, esp candida
-not effective against bacteria

Front 33

griseofulvin

Back 33

antifungal
-fungistatic
-used to treat superficial fungal infections (ringworm)
-not effective against C. albicans or bacteria

Front 34

amphotericin B

Back 34

antifungal
-impairs functin of cell membrane
-used for systemic fungal infections

Front 35

Synthetic chemotherapeutic agents

Back 35

chemicals synthesized and used for treating certain diseases

Front 36

sulphonamides

Back 36

used to treat staph and strep respiratory infections, UTI;s from gram neg bacteria, wound infections and endocarditis

Front 37

Nitrofurans

Back 37

sulphonamide
-have nitro groups to give it the antimicrobial affect
-broad spectrum, some protozoa and some superficial fungi
-action against cell enzymes and DNA

Front 38

problems with nitrofurans

Back 38

gi upset
hypersensitivity
potential carcinogens?

Front 39

quinolones

Back 39

sulphonamide
-not for growing animals
-work agains DNA formation and bacterial cell membrans
-broad spectrum aerobic

Front 40

isoniazid

Back 40

sulphonamide
-effective against mycobacterium
-blocks most internal cell reacitons
-toxicity is rare