Card Set Information
Drugs, Microbes, Host- The Elements of Chemotherapy
What is chemotherapy?
Chemotherapy refers to the use of chemical agents (drugs) to treat disease. This may or may not refer specifically to cancer.
What do antibiotics do?
They kill organisms without harming humans.
What was initially used as an antibiotic?
What is antimicrobial therapy?
Antimicrobial therapy refers to the use of chemical agents to treat disease by specifically killing or inhibiting microorganisms that cause the disease without harming the host's cells.
What do chemotherapeutic drugs do?
What is propholaxis?
A measure taken for the prevention of a disease or condition.
How are antimicrobial drugs produced?
Naturally or synthetically.
Antibiotics are made by living organisms and are effective against other living things.
What are semi-synthetic drugs?
They are lab altered natural products.
What are semi-synthetic drugs also called?
They are also called "derivatives" of a particular drug.
How are synthetic drugs made?
They are made by people in a laboratory.
What are things in the
that have been used in the disease treatment process?
Moldy bread and grains; plant extracts; plant minerals (leaves, bark, etc); lichen & fungus; alcoholic fermentation products; animal products (hair, saliva, fat, etc).
What happened in 1910?
The first actual laboratory test of an antimicrobial substance was tested and successful.
What was the first antimicrobial lab test in 1910?
Test of an antimicrobial substance was "Salvarsan" for the treatment of Syphilis (arsenic plus phenol) was successful. Patients were cured of their Syphilis but soon died of heavy metal poisioning.
What happened in the 1930's?
A red dye called protonsil was used against infections caused by gram positive bacteria.
What could be extracted from protonsil (the red dye)?
The active ingredient was found to be "sulfanilamide" and could be extracted from the red dye.
Who discovered a substance produced by Penicillium mold?
What does Penicillin work on?
Gram positive bacteria.
Who received the Nobel Prize in 1945 for discovering penicillin?
Fleming, Florey, and Chain.
What could happen if you burst spores (mold spores) that are growing?
They could become air bourne and contaminate other people.
What are antibiotics?
Antibiotics are common metabolic products of aerobic spore-forming bacteria and fungi.
What are antiobiotics that work against bacteria?
Bacteria in genera Streptomyces and Bacillus.
What are antibiotics that work against molds?
Molds in genera Penicillium and Cephalosporium.
Antimicrobial drugs should be what?
They should be selectively toxic.
What does selectively toxic mean?
The antimicrobial drugs being used should kill or inhibit microbial cells without simultaneously damaging host tissues. (You want to hurt the organism, not the patient).
Interactions between drug and microbe
As the characteristics of the infectious agent become more similar to the vertebrate host, complete selective toxicity becomes more difficult to achieve and more side effects are seen.
How many mechanisms of antimicrobial activity are there?
What are the 5 mechanisms of antimicrobial activity?
1. Inhibition of microbial cell wall synthesis (ex. Penicillin).
2. Disruption of microbial cell membranes (ex. Polymyxin).
3. Inhibition of microbial protein synthesis/interference with bacterial ribosomes (ex. Streptomycin).
4. Inhibition of nucleic acid synthesis (ex. Rifampin).
5. Blocks key metabollic pathways.
What are 8 cell wall inhibitors?
What inhibits the cell membrane?
What are broad spectrum drugs?
Targets a wide variety of organisms such as a component common to most pathogens. Often will disrupt normal bacterial flora of a host.
What are limited spectrum drugs?
Targets a specific cell component that is found in only certain microbes, ex. gram positive organisms.
What do most bacterial cell walls contain?
What blocks synthesis of peptidoglycan, causing the cell wall to lyse?
Penicillins and Cephalosporins.
Antimicrobial drugs kill...
Active young growing cells.
Penicillins are less effective against what kind of organisms?
They are less effective against gram negative organisms.
Broad spectrum Penicillins and Cephalosporins can cross the cell walls of what?
Gram negative bacteria.