Dear Prudence

I think Carl gets right to the heart of the issue both in this online conversation and in his book. "Are we really just getting started thinking about this stuff?" he asks.

In some cases, it seems that regulators are forcing researchers to go to near-impossible lengths to ensure safety despite no conceivable risk. (Hillman's cavity-fighting tooth bug?) In other cases, researchers appear to be rushing ahead with no one stopping them.

Carl highlights what I consider a prime example of the latter issue in "Darwin at the Drugstore" (subsection "Skin of the Frog"). He describes how Michael Zasloff, the researcher who first began developing antimicrobial peptides (AMPs) as a new class of anti-infectives felt sure that bacteria could never develop resistance to them.

It took a clever evolutionary biologist, McGill's Graham Bell, just one summer to prove Zasloff wrong.

But that hasn't stopped other researchers from rushing forward with new AMP "antibiotics," some of which have now entered clinical trials.

Why does that make some, including myself, so nervous?

Antimicrobial peptides are the human immune system's front line of defense. As part of a concerted immune response, they don't prompt the evolution of resistance in bacteria. But when used in isolation (like an antibiotic), we now know they can and do breed resistance.

So are we risking the rise of genes that will make bacteria resistant to the body's own AMPs? We've seen how fast antibiotic-resistance genes proliferated through the bacterial world over the last 60 years. There's no turning back the clock on that one. But this ups the ante!

So back to Carl's wise question: "Are we really just getting started thinking about this stuff?"