I am absolutely blown away by this work out of Peter Dorrestein's lab. This work is some of the most simple and elegant MS work that I have seen in years.
This is what they do, essentially:
1) They grow a lawn of methicillin resistant staph aureus (MRSA)
2) Then they take some bacteria and draw a "t" across the surface of the MRSA culture
3) They look to see if the new bacteria inhibits the MRSA growth in any way.
4) If it does, they ionize the area of the zone of inhibition and analyze the ions by MS/MS.
Of course, its a bit more complicated than than, but this is essentially the plan.
I saw Dr. Dorrestein speak on this subject a while ago, but I've only recently been able to catch up on the literature and their current work, including a compound they've discovered that is significantly more potent than the most powerful antibiotics we currently have in use.
I sincerely suggest that you take a look at some of his papers. I think that you'll be impressed, and perhaps feel a little dumb for not thinking of it yourself....
For more of this lab's great work, click here.