The problem that jumps out at me is the mechanism. Any time you've a monoclonal sort of product that's reproducing as much as these would be when the body's in an infected state, you will have mutants. It's likely that most of those will be benign, but some could be very nasty - maybe it latches on and destroys useful cells like a virus does. Maybe it can do so AND be passable to other humans.

While antibiotics have been misused and they do have downsides, they aren't infinitely reproducing as these are. Given that, I'd have to see some sort of serious evidence that their benign to everything else before wanting to see them out there.

The even bigger problem, at least from what I've heard, is the fact that the antibiotic-resistant bacteria themselves aren't the real source of damage, in the case of staph; rather, it's the digestive chemicals they excrete that kills off the body cells.

What happens when a bacteriophage rewires a cell's chemistry to start churning out more bacteriophages? It starts consuming nutrients to do so. LOTS of nutrients, more than a bacteria that's just reproducing would. This triggers the bacteria nearby to start producing more digestive chemicals, to break down more human flesh into nutrients... and, when the bacteria rupture and die to release more virii, one last burst of enzyme is released as well.

I wouldn't want to be a test subject for the stuff.

I'd have to look into the mechanisms of the particular bacteria prior to judging that, but on the overall, I'd be less worried there. Typically, if they're living with some access to our bloodstream, most of the nutrients should be readily available - or they could be administered via IV.

If I get a chance today, I'll try to look up the mechanism - or have Amber do it, considering she's actually studied parasitology (sp - and I'm too damn lazy to check it), which will give her a leg up on us.