April 07, 2015
Can antibiotics “evolve” effectiveness against antibiotic-resistant bacteria? No—at least not yet. But that doesn’t mean smarter antibiotics aren’t a possibility.
If bacteria can evolve the genetic means to resist antibiotics, why can’t antibiotics combat that resistance with evolved effectiveness? One might counter that antibiotics are not living organisms, and thus clearly can’t evolve biologically. That’s true, and I’m not suggesting that living antibiotics are next (bacteriophages are a subject for another time), but even inanimate objects can be designed in adaptive ways.
One hundred years ago, who would have predicted glass that darkens in the sunlight and is clear in the dark? Now you can get sunglasses with photochromic lenses in any drug store. What about “mood rings” that turn red when you’re angry, or heat-absorbing, colorimetric egg timers? Or holograms that present different pictures when viewed at different angles?
In the realm of healthcare is a self-adapting wound dressing that senses the state of the wound (in this case, how wet or dry it is) and provides the appropriate amount of absorption throughout the entire wound healing process.
Harvard’s Wyss Institute for Biologically Inspired Engineering uses “nature’s design principles” to envision and create “self-organizing and self-regulating” products, including health products—like their “lung-on-a-chip” drug screening platform. Perhaps their Programmable Nanomaterials platform will take on the development of evolving antibiotics.
The simplest hypothetical example of an evolving antibiotic might be one that starts as the first-line treatment choice—the least advanced antibiotic that would treat a sensitive strain of a given bacterium—and can sense immediately if the pathogens are resistant. If they are resistant, the second-line choice is activated. No need for resistance testing and if the first-line choice works, no need to add to the pressure nudging the pathogen to develop resistance to the second-line choice.
Even better would be an antibiotic that doesn’t deploy at all unless a bacterial pathogen is causing the infection being treated. Even in the context of blue-sky thinking about evolving antibiotics, however, it is hard to imagine an antibiotic that evolves this way, because the human body is full of all kinds of bacteria. No harm in stating the challenge, though. We’ve been amazed before and I expect we will time and again.
The final challenge of any novel treatment or invention, though, is distribution. If this discovery took place in the public sector so that the evolving products would be immediately affordable and globally available (especially in low-income countries, where most of the deaths from infectious diseases occur)—that’s real blue-sky thinking.
Hellen Gelband is the Associate Director of the Center for Disease Dynamics, Economics & Policy.
Image by Damien Hirst, retrieved via Flickr and used with Creative Commons license.
