Antibiotics/Disinfectants Flashcards
MIC
minimum concentration that inhibits growth
process of determining MIC
Examine the next most dilute solution, and then the next, and so on until you find a tube that does not have any bacterial growth.
The concentration of antimicrobial agent in that tube is the MIC, because that is the most dilute concentration that inhibited growth
MLC
lowest concentration of a drug that kills a pathogen – looking at a subculture
it is the solution after the MIC that has NO growth
disk diffusion test
disks with particular drug are placed on a broth
observation of the size of the zones around the growth
Kirby bauer
zone of inhibition, tells you if sensitive or resistant
disinfection
removal of pathogens
sterilization
removal of all cells
disinfectant applied to living tissue
antiseptic
E test
similar to disk diffusion but uses strip > over growth
indicates MIC
strip contains a gradient of antibiotic
B-lactam ring
most crucial feature of penicillins
Antibiotics that inhibit cell wall synthesis
vancomycin
cephalosporin
penicillin
isoniacid
** C-VIP
antibiotics that inhibit translation
streptomycin
erythromycin
tetracycline
chloramphenicol
** ChEST
antibiotics that inhibit metabolism
sulfamethoxazole
trimethoprine
antibiotics that inhibit nucleic acid synthesis
Nalidixic acid
cipro
Mechanisms of drug resistance
- Prevent entrance of drug
- drug efflux
- modification of target enzyme
- cleavage- i.e. B-lactam ring
- use of alternative pathway to increase production of target metabolite
