I've cultured staph off and on (it seems to be my only bug that disappears and then reappears, though I'm pretty sure it's always in there) for as long as I can remember. They treated it with Bactrim as a young child, and I had an allergic reaction to the drug, so then I believe I treated it with ceclor, as needed. I was also on Biaxin and Augmentin a lot as a child, but I think by then I was already culturing PA so it could have been for either.
I'm pretty certain they never treated the staph just for the sake of eliminating it - unless I had an active infection they left it alone. As an adult my staph has never to my knowledge caused any real problems. Every time I get an exacerbation it seems to be identified as PA and/or achromobacter. So while my staph might get treated incidentally b/c the antibiotics hit it along with the other bacteria, I don't think it is ever treated specifically.