Antibiotics

Helpfulness: 0
Set Details Share
created 3 years ago by Stephen_Clark
11 views
updated 3 years ago by Stephen_Clark
Subjects:
microbiology
show moreless
Page to share:
Embed this setcancel
COPY
code changes based on your size selection
Size:
X
Show:
1

Antibiotics

  • Product produced by a microorganism or a similar substance produced wholly or partially by chemical synthesis, which in low concentrations, inhibits the growth of other microorganisms
2

Our Natural Defenses can be augmented with externally provided defenses like:

ANTIBIOTICS, DISINFECTANTS AND ANTISEPTICS

3

Paul Ehrlich and Sahachiro Hata

  • Chemicals with selective toxicity
  • ORIGIN: Selective Stains
  • DRUG: Arsphenamine (1910); looking for something to target Treponema pallidum
  • Treatment for Syphilis
4

Gehard Domagk

  • Drugs are changed in the body
  • ORIGIN: Prontosil-->cured a fatal streptococcal infection in mice - did not work in test tube
  • DRUG: Sulfanilamide (1935)
  • prontosil --> sulfanilamide
  • was split by a enzymes in animals blood into the first of the “Sulfa drugs
5

Alexander Fleming

  • Microbes make antibiotics
  • ORIGIN: moldy culture plate
  • DRUG: Penicillin (1928)
  • penicillin developed in US in 1941 - spores from mold on coats of scientists
6

Selman Waksman

  • Soil Streptomyces make antibiotics; comes up with definition of antibiotic
  • ORIGIN: Penicillin development
  • DRUG: Streptomycin (1943)
  • streptomycin - bacteria produced antibiotics too. Many began screening soils looking for antibiotics
7

Ideal Drug Characteristics

  • Selective toxicity
  • Bactericidal vs. bacteriostatic
  • Favorable pharmacokinetics
  • Spectrum of activity
  • Lack of “side effects”
  • Little resistance to development
8

Selective Toxicity

  • against target pathogen but not against host
  • LD50 (high) vs. MIC and/or MBC (low)
9

Bactericidal vs. bacteriostatic

  • Static rely on normal host defenses to kill or eliminate the pathogen after its growth has been inhibited
  • CIDAL given when host defenses cannot be relied on to remove or destroy pathogen
10

Favorable pharmacokinetics

  • reach target site in body with effective concentration
  • drug interxns, how drug is distributed, metabolized and excreted in body (unstable in acid, can it cross the Blood-brain barrier, etc)
11

Spectrum of activity

  • broad vs. narrow
  • broad spectrum - wide
  • Narrow spectrum - narrow range (pathogen must be ID’d)