Ch. 19

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Ch. 19 Importance of Bacteria!
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• Used in food yogurt, cheese, sauerkraut
• Decompose dead things
• E-coli in your stomach
• Sewage treatment
• Nitrogen fixation convert nitrogen from air to
  a form that plants can use.

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Bacteria Disease

• Examples of disease caused by bacteria
• Bubonic Plague carried by fleas on rats.
• Ring around the Rosie
• Pocket full of posies
• Ashes, Ashes
• We all fall down

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Escherichia coli (E-coli)

• A whole family of bacteria, not all of which are
  harmful.
• Good - Depend on E. coli in our intestines for
  Vitamin K and B
• Bad - E-coli (0157H7) symptoms Bleeding, loss
  of water, kidney failure

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Some Terms to know

• Pathogens viruses and bacteria that are disease
  producing agents
• Virulence the ability to cause disease

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3 Steps to Disease

• Contamination pathogens are present
• Through air, food or water
• b. Direct contact (touch, body fluids, etc.)
• c. Contact with a carrier of a pathogen (tetanus
  lockjaw comes from bacteria found on soil
  particles)

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Tetanus - medical condition characterized by a
prolonged contraction of skeletal muscle fibers
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3 steps continued

1. Infection pathogens multiply in body
2. Disease disturbance in the healthy body, so it
   can no longer carry out its normal functions.

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Bacteria cause disease in one of these 2 ways

1. Break down cells to use as a food source.
   (Mycobacterium tuberculosis)
2. Release Toxins (E. coli)

M. tuberculosis - destroys lung tissue can enter
blood stream destroy other tissue.
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Coping with Disease

• Immunity resistance to a pathogen that is
  acquired or inherited.
• Antibodies proteins that the body makes to
  destroy pathogens.
• Antibiotics drugs that attack and destroy
  bacteria. (before these, people died of things
  like strep throat!)

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Major Antibiotic

• Penicillin
• Alexander Fleming 1928 discovered by accident in
  lab
• A type of mold
• Different types (amoxicillin, etc. come from
  different forms of the Penicillin fungi mold)

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Controlling Bacteria

• Sterilization heat of chemicals to kill
  bacteria
• Bacteria cannot survive high temperatures for
  very long
• Examples Autoclave at the vet, dentist, doctors
  office, etc.

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• Disinfectants chemical solutions to reduce the
  number of bacteria
• Examples Antiseptics, Antibacterial products
  (soaps, cleansers, kitchen utensils)

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Controlling bacteria continued

• Soap wash bacteria away may be good enough
• Food preservation salt, vinegar, sugar, heat,
  low temperatures (refrigeration doesnt kill
  just slows growth!)