3-Antibiotics Flashcards
chemotherapy
treat of dz with use of chemicals to kill/impair growth of microorgs
-antimicrobial or antibacterial
selective toxicity
leveraging biochem diff b/t host and pathogen to kill/inhib without harming host
bacteriotstatic
no overt killing
-therapeutic success dep on host immunity, buy time for host
-non life threatening
bactericidal
overt killing
use when immune sys not counted on to combat pathogen
-immunocomp patients, life threatening dz
broad spectrum
cover large variety of bacteria
-useful for life threatening to cover unknown cause of infection
can disrupt normal microbiota
ampicillin
narrow spectrum
cover only small subset of bacteria
-avoid disrupting normal microbiota
-have to id causative agent to be confident
methicillin
antibiotic synergism
combo two antib with enhanced bactericidal activity when used together
trimethoprim + sulfonamide
antibiotic antagonism
combo of antib that one interferes with activity of other
therapy progression
- empiric- treatment while waiting for lab results
- targeted-
- adjusted
antibiotic naturally occuring?
thru random mutation or acquisition of genetic elements carrying resistnace
antibiotic use
LEADS to resistance not causes
bc enriches spread of bacteria
causes of resistance crisis
- overuse and inapprop prescribing
- extensive use in agriculture
- lack of discovery/development
what can physicians do
- follow protocols
- use diagnostics
- only prescribe when needed
4.
when are antibs necessary
- surgery
- chronic conditions
- organ transplants
- dialysis
- cancer therapy
minimum inhibitory concentration
MIC
to test susceptibilty- lowest antib concentratin that inhibits growth
in broth culture, culture on agar (kirby bauer, E test)
minimum bactericidal concentration
lowest amount that kills 99.9%