Chapter 9 Questions Flashcards
who is usually credited with the discovery of penicillin
fleming
whose discovery of streptomycin stimulated an intense search for other antibiotics
waksman
the use of arsenic compound salvarsan as a treatment for syphilis is credited to
Ehrlich
chemotherapeutic agents that are natural products of microorgranisms are most specifically referred to as
antibiotics
who is generally credited with the discovery of sulfamilamide as a chemotherapeutic agent?
Gerhard Domagk
___ ___ are activities of chemotherapeutic agent that damage the host either by inhibiting the same process in the host as in the target cell or by damaging other processes
side effects
T/F: the minimum lethal concentration (MLC) is the lowest concentration of drug from which organisms fail to recover when removed from the drug
true
T/F: agents that are static and therefore do not killing infecting microorganisms are not useful as chemotherapeutic agents
false
a drug that disrupts a microbial function not found in animal cells usually has a higher therapeutic index
true
inhibits protein synthesis
erythromycin
likely to have the most toxic side effects to humans
disrupters of cell membrane structure
isomiazid is a narrow-spectrum antibiotic that
is one of the few drugs effective against Myobacterium tuberculosis
chemotherapeutic agents that are chemically modified natural products of microorganisms are most specifically referred as
semi synthetic drugs
chemotherapeutic agents that are artificially produced are most specifically referred to a
synthetic drugs
the ratio of toxic dose to therapeutic dose is called
therapeutic index
the minimal lethal concentration (MLC) is the __ concentration of a drug that __ particular pathogen
lowest, kills
the lowest concentration of antibiotic that prevents growth is the
minimal inhibitory concentration (MIC)
list the desirable general characteristics of antimicorbial drugs
selective toxicity, broad-spectrum of activity, bacterial rather than bacteriostatic
when a chemotherapeutic agent is effective against many different pathogens it is said to be what kind of antibiotic?
broad-spectrum
T/F: in a disk diffusion assay for drug susceptibility, a drug producing a larger clear zone is always more effective than a drug than to one producing a smaller clear zone
false
list the things that affects the size of the clear zone in a disk diffusion test of antimicrobial susceptibility:
the initial concentration of the drug, the solubility of the drug, the diffusion rate of the drug
a quantitative antibiotic sensitivity test that utilize plastic strips impregnated with an antibiotic of interest
E Test
T/F: when it comes to Kirby- Bauer disk diffusion test, bacteria used to swab the plate should be at least a week old
false
T/F: penicillin does not inhibit protein synthesis
true
the most selective antibacterial agents are those that interferes with bacterial cell wall synthesis. this is because:
bacterial cell walls hae a unique structure not found in eukaryotic host cells
in addition to inhibiting the transpeptidation in cell wall synthesis, penicillins may have also destroy bacteria by
stimulating proteins to form holes in the plasma membrane
