Download Controlling Disease

Controlling Disease
We are an attractive dish for microbes!
Louis Pasteur
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People thought that food went off because it
was in contact with air. They thought:
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Air + food
microorganisms grow
Pasteur said that microbes come from
microbes
He did som experiments to prove this -
Louis Pasteur
Pasteur’s Experiment
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He poured some grape
juice in 2 flasks
He then produced a
‘swan neck’ in the glass
He heated the flasks to
boiling
One flask was left
The other had its neck
broken off
Which went off? Why?
Pathogens
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1.
2.
= microorganisms which cause disease
Drugs are used to help people with
diseases
Painkillers – relieve the symptoms without
curing the disease
Antibiotics – chemicals which kill bacteria,
but not viruses. Viruses develop in cells and
are hard to kill
Bacteria Drug Resistance
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Bacteria in nature are
varied. A few have the
resistance to antibiotic
When the antibiotic is used
there is a natural selection
for the bacteria with the
most drug resistance.
These survive and breed
and become more common
Testing for Antibiotic Resistance in
Bacteria
Clear of
bacteria
Discs of different
antibiotics
Bacteria colonies
growing near disc of
antibiotic
Antibiotic Resistance in Bacteria
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Many strains of bacteria have resistance to
antibiotic due to natural selection
So we need a range of antibiotics to fight
disease with the best one for the job
To slow down more antibiotic resistance
developing in pathogenic bacteria we need to
avoid over using antibiotics
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