Explain why methicillin resistant Staphlococcus aureus (MRSA) is more prevalent now than it was only 30 years ago. See Section 1.7 (Page) . Explain why methicillin resistant Staphlococcus aureus (MRSA) is more prevalent now than it was only 30 years ago. See Section 1.7 (Page) . Methicillin resistance causes an infection to spread more rapidly. Antibiotics cause mutations in Staphlococcus aureus that lead to an increase in the number of methicillin-resistant strains. Frequent and inappropriate use of methicillin-type antibiotics has provided selective pressure that has resulted in an increase in the proportion of methicillin-resistant strains of Staphlococcus aureus. Diseases like AIDS have made people more vulnerable to infections from Staphlococcus aureus.

Frequent and inappropriate use of methicillin-type antibiotics has provided selective pressure that has resulted in an increase in the proportion of methicillin-resistant strains of Staphlococcus aureus.

Explanation: The methicillin resistant Staphlococcus aureus is an example of the Theory of Evolution explained by Darwin. He stated that evolution is brought by 3 principles: Variation - the variety of species allows them to adapt better in the environment; Heridity - when those characterists necessary for survival passes on to the next generation; Natural Selection - the organism which is the most adapted to the environment survives to passes on their characteristics;

In a strain of Staphlococcus aureus, there are strains which are resistant to the antibiotics. The constant use of the medicament, and sometimes, the misuse of it, can select those strains which are resistant. As these characteristics are crucial for their survival, they are passed on to the next generation.

This is why the rate of methicillin-resistant Staphlococcus aureus has increased along the years.

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