mod 10 Flashcards
what treatments existed before antibiotics
- cauterization
- amputation
- mercury and arsenic chemicals (toxic) - for syphylis early 1900s
who discovered penicilin
1928 - flemming. accident
purified and produces in 1942
sulfa drugs discovery?
1935
antimicrobial
agent against bacteria/virus parasite etc
more specofoc: antviral, antifungal etc
antibiotic
- natural source (traditionally) that stops growth of microorganism
- today most semi synthetic or synthetic
- antibacterials…
disinfectant
- chemical agent to eliminate microorganism but tol toxic for human use
antimicrobial resistance
resistant organism still living in body after normal dose of antimicrobials
explain antimicrobial therapytriangle
in my notes
antimicrobial resistance invloves what
altered of synthesis of new protien by the microorgansim
changes lower affinity to antimicrobial
bacteria raquire resistance genes via…
- dna transfer
- conjugation (pili)
- transduction (bacteriophage)
- transformation
3 main mechansims of resistance
- altered target site
- altered uptake/increased efflux (decrease amount of drug that reaces cell, less permeable cell wall or pumping out drug)
- drug inactivation
example of drug inactivation
penicilyn Beta lactaameses break down B lacatm ring of penicilin and then it doesnt work
3 ways to classify antibacterial agents
- bacterialcidal vs bacterialstatic
- mechanism of action
2, chemical structure/family
bacteriocidal vs bacteriostatic
cidal- kill
static- stop growth so IS can elimiate
mechanisms of action
- cell wall synthesis
- protien synthesis
- nucleic acid synthesis (DNA, folic acid synthesis inhibition
(targets)
Tetracycline antibiotics
- tetracycline and doxyxyxline
- inhibit protien formation
-bacteriostatic - for chlamidia and mycoplasma
- supress gut flora, photosensitive, teratogenic
- resistance by new bacteria cell wall being able to pump it out
Quinolones
- bacteriacudal
- ofloxacin, ciprofloxin
- inhibit dna gyrase (only bacteria have this, makes dna unreadbale but doenst affect human cells)
- N,V ab pain
- resistance occurs when CW change or target enzymes cahnge
- UTI
- Chlaydia
- Gonnarhea
glycopeptides
- bacteriocydal
- gram pos only, too big for gram neg
- vancomycin
- treat c diff, or people who cant have b lactam
- inhibit additions to cell wall
sulfonamides
- bacterialstatic
- sulfadiazine
- stop FA synthesis
- for gram neg
- avoid in early preg nd late preg bc of FA and affects billirubin
Aminoglycosides
- bacteriocydal
- streptomycin, neomycin, gentamycin- D (bad, only if really needed in pregnancy)
- fucks w 30s subunit, cant read and reproduce mRNA
- intravenous or intramuscular entry
- can cause ear/kidney damage to fetsu
- main resistance comes from enzyme modifying
- aerobic gram neg bacteria
- good for prolonged rupture of memebranes and babies w sepsis
metronidazole
-flagyl
- damage w free radicals
- only for protozoa, anaerobic
macrolides
- bacteriostatic
- rythromycin,azithromycin
- stop release of tRNA,
-high resistance (efflux pump, plasmids, alter binding site) - treat STI when no tetracycline (bc teratogen)
erythromycin
- good for preventing GBS
- good when cant have penicilin
- chlamidia and mycoplasma
azithromycin
- penetrates tissue w slow relese
- shorter and more effective dosage
