What is mrsa, why does it pose serious health risks especially for a health care professional, and how is antibiotic resistance an example of evolution?  

MRSA or Methicilin Resistant Staphylococcus Aureus is a stash infection or bacterial infection just to be general. Normally staph infections are pretty easy to treat, and most people are prescribed antibiotics to fight this infection. The issue however with MRSA is that the infection is very resistant to the antibiotics normally used to treat it, making it much, much more difficult to treat. MRSA infections are greatly difficult to treat especially in those with weakened immune systems (which is why hospitals, Rehab, and nursing homes have high amounts of such infections), and can quickly go from a bad skin infection to fullbblow sepsis (blood poisoning) and death.

MRSA is a prime example of evolution at work. When doctors prescribe a medication two types of things can lead to resistance; prescription of unessecary antibiotics, or the patient doesn't follow doctors instructions when taking medications. The premise tends to be the same in either case with a slight variation. As Staph bacteria naturally occurs in the skin, if someone is being treated and doesn't have a staph infection, but is taking antibiotics, the staph bacteria actually can developed a resistant strain so that a break in skin actually leads to a MRSA infection. For those being treated for a nonresistant strain, when they don't follow doctors instructions to complete antibiotics even if they are feeling better, there is a reason why you should. Each copy of bacteria is not exactly the same sometimes developing mutations with some being a bit more difficult to destroy, which is why the full course of antibiotics is needed to destroy them. If it is not completed the bacteria that is left will actually replicate causing a full blown resistant infection.

The main issue with MRSA is that it is a common bacteria that has mutated and groan to be resistant to bacteria. Antibiotics are everywhere in Healthcare settings and many people that aren't compliant with medication regimes end up in the hospital for some of the most minor things. However their hospital visit can leave a massive amount of Staphyloccoaus bacteria after their visit, and can hide anywhere. In a normal human we can easily keep these bugs out, but a break in the skin of people who have decreased immune system efficiency (like many of the people that actually need to be in the hospital) when exposed can contract a dangerous infection. This also is advanced by the fact that we don't wash rooms with a powerhose or take a shower after every patient encounter... What I mean is that Healthcare provisera can have MRSA on their skin, without realizing it and if they are uncareful can pass it to those who are susceptible to it.