[busyant]

I'd rather not mention my recent employer.

But these startups do exist: look up Achaogen (achaogen.com) and Tetraphase (tphase.com).

Cubist Pharmaceuticals was a big antibiotic developer that was recently purchased by Merck. Cubist itself bought another startup called Trius Pharmaceuticals, which had developed a newly marketed antibiotic.

So, there is $$ to be made in antibiotic drug development, but as many people on this thread have pointed out, there is more $$$$ to be made in other therapeutic areas (e.g., oncology).