exam three (antimicrobial therapy) Flashcards
_____ cause disease
microbes
who found that trypan red kills trypanosomes
paul ehrlich
paul ehrlich also found that arsphenamine treats _____
syphilis
arsphenamine kills the microbe but not the human which gave it what name
“magic bullet”
gerhard domagk found ___ which treats both staph and strep
prontosil
pronotsil works because it is metabolized to sulfanilimide; which provides ____ and kill microbe (sulfa drugs)
protection
alexander fleming came up with
penicillin
mold had taken up residence on a plate and inhibited ____ growth around the mold
staph (colonies would lyse and die around the mold)
mold releases antimicrobial penicillin to compete with bacteria; it is a natural ____
antibiotic
antimicrobial chemotherapy that kills microbes but not you has
selective toxicity
what are the antimicrobial agents
antibiotics
synthetic
antimicrobial chemotherapy can be ____ or ____ spectrum
narrow; broad
antibiotic is _____ produced
naturally
kill microbe but synthetic (modified natural antibiotic)
synthetic antimicrobial agent
broad spectrum has effect on ____ bacteria (ex. all gram + species)
many
narrow spectrum are ____ effective; have to know specific species
less
least amount of antibiotic need to stop microbe (can be cidal or static)
minimum inhibitory concentration
to find min. inhibitory conc. you have tubes with increasing concentration of antibiotic and look for
opaqueness (max. growth) should be seen in 0 antibiotic conc. tube
the least amount of antibiotic that showed no growth is your (just stop growth; not yet looking for killing numbers)
min. inhibitory conc.
want an antibiotic that will kill microbe at least amount this is (cidal)
min. lethal concentration
(add antibiotic disk to plate) zone of clearance shows bacteria that have died and the outer edges of the ring is the min. conc. (qual.)
kirby bauer method
strip inoculated with different conc. of antimicrobial; zone of clearance will give you MIC (min. inhib. conc.) based off where zone of clearance stops
Etest
smaller zone of clearance means ____ antimicrobial; ___ use of MIC needed
less effective; less
the least amount of ____ is better for humans and to prevent resistance
MIC
things that can be manupilated in prokaryotes (antimicrobial therapy)
cell wall, membrane, metabolism, Nuc. acid synth. , protein synthesis
Beta lactam ring (similiar to D-Ala- D-Ala) is required for ____ to work
penicillin
penicillin (cell wall inhibitors) has more effect on gram ___
+
peniciliin binding protein works as a transpeptidase to elongate ____; penicillin blocks this
peptidoglycan
penicillin __ and __ are natural (come from penicillium)
G and V
semi-synthetic penicillin (cell wall inhibitors) have had change to ___ ____ ring
beta lactam
methicillin and oxacillin are resistant to ___ ____ (semisynthetic)
beta lactamase
ampicillin and carbenicillin are __ ___ senstitive (semisynthetic)
beta. lactamase
alot of people can be hypersensitive to the ___
cillin’s
cephalosporins (cell wall inhibitors) are ____ ____ and have Beta-lactam ring
natural antibiotic
glypeptides (cell wall inhibitors) have _____
vancomyocin
vancomyosin works on G _ and binds to d-ala-d-ala
+
vancomyosin attaches to D-Ala and blocks transpeptidase by hiding d-ala from ______ ____ ___
penicillin binding proteins
vancomyosin is a last resort because it has a lot of ____
resistance
protein synthesis inhibitors bind to ____; can be 30s or 50s
ribosome
______- are amino sugars which bind to 30s; bactericidal for G- (protein synthesis inhibitors)
aminoglycosides
waksman screened 10,000 strains looking for _______; first drug for TB
streptomycin
streptomycin can be toxic causes
deafness, kidney damage
_____ bind 30s; broad spectrum (will kill any gram + or -) bacteriostatic (stop growth); (protein synthesis inhibitors)
tetracyclines
tetracycline allows your immune system time to get an immune response by being _____
bacteriostatic
tetracyclines can be toxic causing
kidney and liver damage, yellow teeth
______ (protein synthesis inhibitors) have lactone rings and sugars bind 50s; broad spectrum (mostly natural)
macrolides
synthesis inhibitor that inhibit DNA/RNA polymerase, DNA helicase (prokaryotic unique)
nucleic acid synthesis inhibitors
synthetic, bacteriocidal, broad spectrum (ciproflaxacin); inhibits DNA synthesis in human cell and bacterial cell (nucleic acid synthesis inhibitors)
quinolones; fluoroquinolones
inhibitor which blocks metabolic pathways; using structural analogs; bacteriostatic
antimetabolites
_____ use synthesis of folic acid to kill microbe (humans don’t make it; but consume it; microbes make it) (antimetabolite)
sulfonamides; block production of folic acid
____ combines with sulfa drug and are _____ at blocking two parts of metabolic (folic acid) pathway (antimetabolite)
trimethoprim; synergistic
semisynthetic (cell membrane disruption); kills G +; binds to membrane and forms pores
daptomycin (cyclic lipopeptide)
_____ binds membrane; makes it more permeable; gram - (highly toxic to injest) (cell membrane disruption)
polymyxin B
main microbial clearance mechanism
immune system
when immune system cannot effectively clear microorganism
infection
resistance can be caused by ___ ___; drug can’t get past outer membrane/layer
reduce uptake
microbes can have ___ ___; takes things inside prokaryote that don’t belong and pumps them out (multidrug resistant)
efflux pumps
Beta-lactamase breaks __ ___ __; without the ring the drug cannot block peptidolycan synthesis (Effect on penicillin)
beta lactam ring
microbe can ____ aminoglycosides; aids in resistance
acetylate
enterococcus has changed D-Ala-D-Ala to D-Ala-D-Lac so that ____ cannot attach but works for cell wall
vancomyocin
mutation, horizontal gene transfer, antibiotic resistant plasmids are all ___ ____
acquired resistance
also acquired resistance can be caused by ____ of antimicrobials that selects for resistant strains
overuse
____ use host cell machinery
viruses
HIV: can use reverse trascriptase inhibitors to combat; AZT can be used to target viral ____ _____
DNA polymerases
blocks influenze virus neuraminidase (budding protein) inhibits budding
tamiflu
protease inhibitors can be used for ____ so that virus cannot make new viral strands
HIV
fungal infections are hard to treat because they are ____
eukaryotes
differences in fungi that can be targeted
sterold in membrane; chitin in cell wall; folate synthesis
there can be __ or ____ mycoses depending on whether internal or external infection
superficial or systemic
protozoans are hard to treats because they are _____
eukaryotic
chloroquine is an antiprotozoan used for
malaria
