MRSA Question!

[futurern123]

I am writing a research paper on MRSA (I'm a nursing student). So far, I have not been able to find an answer to this question: Why do some carriers of S. aureus remain unharmed by the bacterium, and what causes some to become infected? And are people carriers of MRSA or just s. aureus...?

I know it is commonly found in the nose. If a carrier is in the hospital and develops a MRSA wound infection-- how did this happen exactly?

I know this should be easy to understand...but the sources I am using are not very clear. The audience I'm writing for is supposed to be the general popular, people not in the field of nursing, so I really need to put it in layman's terms!

I've been puzzling over how to explain this. I have a cold so I'm a bit out of it--maybe not thinking clearly!

Thanks in advance...