Download Microbiology - Timber Ridge Elementary

The study of Microorganisms
Gail Wagley (Rose’s mom)
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Most are microscopic (can’t be seen without a
microscope)
Include:
◦ Viruses (eg. “cold viruses”, the flu,
stomach viruses, and food-borne
Norovirus, Hepatitis)
◦ Bacteria (Salmonella, E. coli,
Staphylococcus (staph), Listeria)
◦ Parasites
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Bacteria can multiply from 1 to 100,000,000
cells overnight!!!
One cell can grow overnight on an agar plate
to become a pin-point sized “colony” of a
million cells that you can see
Beneficial (decomposers, digestive bacteria,
penicillin producers)
Harmful (pathogens: cause human or animal
illness)
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Testing Food and Make-up for pathogens
(disease-causing bacteria)
Common Pathogens we recover:
◦ Salmonella (fruits, vegetables, flour, eggs (only one
type), raw or undercooked fish, raw or undercooked
chicken) commonly carried by birds and reptiles
◦ E. coli (fruits, vegetables, cheese, raw or
undercooked meat) carried by mammals (deer, pigs,
cows, humans)
◦ Listeria (vegetables, fruits, milk, cheese, other
processed foods) common in soil
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Wash fruits and vegetables (dirt and animal
contamination)
Completely cook meat
Wash hands and utensils after handling raw
meat
Refrigerate Foods!
Don’t leave cooked food out too long
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Add food to liquid that contains all the things
bacteria love (let it grow!!)
Add that to another media (agar, liquid) that
contains something other bacteria don’t like
or can’t “eat”
Add that to another media that changes color
with the bacteria you are looking for so you
can “recognize” it
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Some E. coli can make you very sick
Some E. coli is beneficial
Any E. coli in food is a sign of poor hygiene
of food-handlers or improper cooking of raw
meat
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Can cause sickness in humans (especially old
and pregnant people)
If found in food, can be a sign of “dirty”
environment and poor food preparation
practices