Download D6 Antibacterials

Aka antibiotics
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https://www.youtube.com/watch?v=2Lr__Mp
VhNA
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Bacteria
◦ tetanus, tuberculosis, cholera, typhoid fever,
syphilis, gonorrhea
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Viruses
◦ Influenza, cold, hepatitis, measles, AIDS
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Fungi
◦ Athlete’s foot, ringworm, fungal meningitis, fungal
pneumonia, oral thrush
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Protists
◦ Malaria, African sleeping sickness, protist giardia,
amoebic dystentery
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1928 Alexander Fleming
◦ Discovered penicillin
◦ 1945 Nobel Prize in Physiology and Medicine
◦ Unable to isolate
compound
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1940- Florey and Chain
◦ Injected mice with deadly bacteria
◦ Some received penicillin and lived!
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1941 given to Albert Alexander
◦ -London policeman with blood poisoning
◦ -5 days penicillin (then ran out
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1941 US = massive development program
1942 = enough for 2 patients
1943 = enough for 10
1944 = 2.3 million doses in time for invasion
of Normandy
Moldy Cantaloupe!
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http://www.cbsnews.com/news/advancedantibiotic-may-fight-resistance-bacteria/
1.
2.
Usually safe except those who are allergic
Antibiotic resistance
-improper use
- overuse
3.
4.
Kill good bacteria
Use of antibiotics in animal feedstock
1.
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Outline what is meant by the term
synergistic effect of ethanol using a suitable
example. (Total 2 marks)
State two differences in structure between
viruses and bacteria.
Viruses do not have:
◦ Cellular structure, cell membrane, nucleus (and
other organelles!), cytoplasm
◦ Viruses are much smaller (submicroscopic) and use
host cells for reproduction of genetic material.
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Bacteriocides
◦ Interfere with formation of cell walls
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It’s all about the side chain!
6-aminopenicillanic acid is not antibacterial
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Penicillin G = not resistant to stomach acid
◦ R = C6H5-CH2◦ Has to be injected
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Penicillin V modified side chain
◦ R = C6H5-CH2- CH2 –
◦ Acid resistant
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Cloxacillin
◦ Side Chain altered so acid resistant and
penicillinase resistant
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Most antibacterials don’t work against
viruses.
◦ Why not?
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Need to prevent transfer/replication of
genetic material
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Block replication-specific enzyme activity
within host cell
Vaccines
◦ Dead or deactivated virus particles
◦ Immune system produces specific antibodies
 Ready for next infection
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Inject their genetic material into a host cell,
but the material is not expressed until a
later date
 Herpes simplex virus, certain types of cancer
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HIV = retrovirus
◦ RNA DNA
◦ DNA becomes a part of host genome
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Attacks immune system by binding to a
receptor glycoprotein (CD4) on T4 immune
cells
◦ T4 cells activate other immune cells
 Difficult to fight because of:
 its ability to mutate (thus rendering a previous treatment
ineffective)
 Its metabolism is similar to human cells
 Incredibly costly treatment