Developing New Antibiotics: Thinking Outside The Bacteria-Filled Box

Bacteria may be having a renaissance. Back in the days of the discovery of penicillin, doctors gleefully handed out antibiotics like they were candy and patients were more than happy to munch them down. They were quite effective too, but bacteria rapidly became resistant. Doctors and scientists worry that we are approaching a time where if we don’t come up with novel antibiotic mechanisms, we will face an epidemic of untreatable bacterial infections. MRSA, methicillin-resistant staphylcoccal auerus, is probably one of the biggest fears.
John Rennie wrote about this issue in the PLoS blog The Gleaming Retort. He describes two strategies scientists are using to try to come up with new weapons in the great antibacterial war. So, naturally one of the first things they turned to was cockroach brains. A group from the University of Nottingham reported a 90% MRSA kill rate utilizing compounds extracted from cockroach and locust brains that were not harmful to human cells. The logic behind their research is that insects have no adaptive immune system (antibodies, lymphocytes etc…), but they are able to survive extremely harsh, contaminated and frankly disgusting environments. Researchers theorize they must rely on extremely potent anti-microbial compounds in order to survive. It is unclear though why these compounds would only be in the nervous system, and the study has not yet been subject to peer-review.
The other strategy is to study a cannibalistic species of bacteria, Bacillus subtilis. Under harsh conditions, the bacteria releases a compound called SDP that causes neighboring bacteria to commit suicide and release precious nutrients. Researchers at UCSD were able to use this compound to neutralize MRSA at a concentration similar to the popular antibiotic Vancomycin.
John Rennie, however, had some reservations, which he sums up very nicely below:

Also, although the idea of novel antibiotics derived from insects that live in germ-ridden circumstances sounds appealingly sensible, I can’t help but be reminded of this story from a couple of weeks ago about novel antibiotic compounds found in frog skin. Which also makes perfect sense, doesn’t it, because frogs, too, need special resources to help them survive in filthy, microbe-rich water.
Unfortunately, that story also reminded me about this story from 2008 about antibiotics from frog skin. Or this one from 1999. Or the stories I wrote about Michael Zasloff and Magainin Pharmaceuticals, which was trying to develop novel antibiotics from frog skin more than 20 years ago.
The stories behind certain drug candidate molecules are so fun and compelling and sensible that you can’t help but think they will work out. And sometimes they do. But more often, they don’t, no matter how great the stories are.

In three paragraphs he summarizes a major problem facing medical technology and public perception nowadays. There is so much to be excited about and to spend money on, but it is very difficult and rare for exciting medical technology to make it to market and become useful to people. We’ll take the glass is half full approach though… half full of delicious life-saving cockroach brains.
The Gleaming Retort: Filthy Places for Antibiotics
Image credit: Matt Reinbold
(hat tip: SCOPE Blog)