BIOL 3200 Lecture Notes - Atypical Pneumonia, Aminoglycoside, Erythromycin
Document Summary
Discovered penicillin while working with staphylococcus, identified mold as penicillin: chain and florey purified active penicillin, selman waksman isolated streptomycin from soil bacterium. Streptomyces griseous: features of antimicrobial drugs, antimicrobial action. Drugs may kill or inhibit bacteria growth. Bacteriostatic drugs rely on host immunity to eliminate pathogen. Bacteriocidal drugs are useful in situations when host defenses cannot be relied upon to control pathogen: most modern antibiotics come from organisms living in the soil. Isolates from bacterial species streptomyces and bacillus as well as fungi penicillium and cephalosporium. Many and good, but of course man-made derivatives have been added to the repertoire: selective toxicity. Antibiotics cause greater harm to microorganisms that to human host: generally by interfering with biological structures of biochemical processes common to bacteria but not humans, spectrum of activity, antimicrobials vary with respect to range of organisms controlled. Narrow spectrum: g + or g- only. Disadvantage of broad spectrum is disruption of normal flora: antimicrobial resistance.
