Penicillin

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Penicillin

• No Longer the Wonder Drug

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What Is Penicillin?

• A class of antibiotics that comes from mold.
• Discovered by accident in 1928 by Alexander
  Fleming, is the first anitbiotic.
• Penicillin antibiotics include ampicillin,
  phenoxymethylpenicillin, amoxicillin, 1st-4th
  generations.
• 50 drugs that are now classified as penicillin.
• Use in WWII and after.

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How Penicillin Works

• Resembles a protein needed for production of cell
  wall.
• Penicillin binds to cell wall of bacteria,
  prevents peptide chains from linking, and lyses
  it.

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Helios.bto.ed.ac.uk/bto/microbes/penicill.htm
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Bacteria

• Can reproduce in 20 minutes.
• Have a single chromosome and plasmids which
  contain spare genes.
• Make copies of plasmids with resistant gene on
  them, passed on to offspring or other bacteria
  through conjugation.

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Resistance

• Bacteria are resistant when they can break down
  the penicillin or disguise themselves.
• Staph breaks penicillin in half with a protein.
• Bacteria produce branched muropeptides, instead
  of single ones.
• Bacteria rebuild PBPs (penicillin binding
  proteins).
• Penicillin resistance started to show in the
  1940s, in 1960 50 of bacteria were resistant.

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www.rockefeller.edu/pubinfo/tomasz042500.nr.htm
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Genes for Resistance

• murM and murN.
• Help in producing branched muropeptides.
• When activated, genes provide penicillin
  resistance.
• When inactivated, bacteria is no longer
  resistant.
• For resistance, bacteria need to have altered
  PBPs and activated murM and murN genes.

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Resistant Bacteria

• S. aureus
• S.pneumoniae
• Bacteria that causes gonorrhea, syphilis, and
  gangrene.
• No strep resistance.

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High Resistance

• Hospitals.
• Small children, especially those in daycare.
• Upper and middle class white families living in
  suburbs.
• Children who had medication in the last 3 months.
• Food eaten from livestock that received
  penicillin.

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http//www.hc-sc.gc.ca/hpb/lcdc/publicat/ccdr/96vo
l22/dr2219ea.html
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How to Prevent Resistance

• Take full course of antibiotics.
• Take medication only for bacterial infections.
• Alternative to penicillin- garlic, sandalwood
  oil.
• Vaccinations.

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www.nfid.org/publications/clinicalupdates/id/pneum
ococcal.html
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Conclusion

• Penicillin resistance is a problem all over the
  world.
• Resulted from unnecessary use of penicillin.
• Many different bacteria are resistant.
• Mostly children in day care and whites living in
  suburbs are at a higher risk of penicillin
  resistance.
• To prevent, people at high risk should be
  vaccinated. Doctors need to prescribe penicillin
  only when necessary.

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