MRSA. Resistance = the ability to survive exposure to a dose of a chemical poison that is usually lethal. MRSA stands for methycillin-resistant Staphylococcus aureus, which is a common skin bacterium that is resistant to a range of antibiotics.
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Resistance = the ability to survive exposure to a dose of a chemical poison that is usually lethal
MRSA stands for methycillin-resistant Staphylococcus aureus, which is a common skin bacterium that is resistant to a range of antibiotics.
'Methycillin-resistant' means the bacteria are unaffected by methycillin, a type of antibiotic that used to be able to kill them.
They make make an enzyme to break down the antibiotic
An MRSA infection means the bacteria have got into the body through a break in the skin (see below) and multiplied, causing symptoms.
The symptoms of MRSA infection vary depending on which part of the body is infected, but there is often redness and swelling at the site of infection.
Sequence: - species during conjugation - plasmids passed into bacteria that have not themselves encountered the antibiotic.
random mutations occur - made more likely by the rapid rate of reproduction (about once every 20 mins)
a beneficial dominant allele would confer a selective advantage
selection pressure - those without the advantageous form of allele will die when the antibiotic is administered
the resistant form rapidly multiply and over successive generations will become more numerous (the “norm”) - natural selection