I think it is because Methacillin..(M in Mrsa) Is in the same drug
class as oxicillin. All of them are synthecic penicillins and because
10 years ago penicillin was used to treat EVERYTHING and abused the
staph evolved therefore creating MRSA so it could survive.

The question I have is what happens if it evolves to where cyldomicin
and Vactomincin and Bactrim no longer work...then what?

Hope that helped.
Manda