# 5641
Proving you should never judge a study by it’s title, today we’ve an absolutely intriguing article that appears in today’s early edition of PNAS (Proceedings of the National Academy of Sciences) called:
The evolution of drug resistance and the curious orthodoxy of aggressive chemotherapy
Andrew F. Reada, Troy Dayc, and Silvie Huijbena
The authors – using malarial resistance as an example – suggest that some of the tactics used today to try to conserve the effectiveness of our drug arsenal may actually be driving the evolution of resistant pathogens.
In this article they question several conventional treatment wisdoms including:
- whether the standard advice - that patients must `finish a drug course even after they feel better’ – is always the best strategy to prevent the creation of resistant organisms.
- whether it is always necessary (or even desirable) to hit an infection hard and fast with mono or combo therapy in order to effect a cure.
Heresy?
Perhaps.
But these authors are not advocating that we suddenly abandon our current antibiotic and drug strategies, only that we need to examine them closely to see if, and when, they really make sense.
And they suggest that what is appropriate for one type of pathogen, or in one part of the world at a given point in time, may not be the best course for another.
While they present a lot of detail (you are going to want to read the entire 7-page article), the basic premise is pretty simple.
Resistant organisms are generally believed to be less biologically fit than their wild type ancestors, which is why we aren’t (yet, anyway) hip deep in resistant organisms.
As long as they share a host with a more `fit’ and competitive strain, they are rarely able to establish a toehold and proliferate.
But when you start applying heavy drug therapy, killing off only the drug sensitive strains, that small population of resistant pathogens can suddenly swell.
It’s almost a Nietzschian concept, really.
Whatever doesn’t completely kill off a pathogen, makes the resistant strains stronger.
Of course, the issues are a great deal more complicated than I’ve outlined here. Rather than go in greater detail, I’ll simply suggest you read the article in its entirety.
The authors suggest that these concepts could apply across a wide range of resistance issues; everything from bacteria, parasites, and viruses to insecticide and cancer chemotherapy resistance.
This article is one of many printed this week that results from:
. . . the Arthur M. Sackler Colloquium of the National Academy of Sciences, “In the Light of Evolution V: Cooperation and Conflict,” which was held January 7–8, 2011, at the Arnold and Mabel Beckman Center of the National Academies of Sciences and Engineering in Irvine, CA.
The complete program and audio files of most presentations are available on the NAS Web site at www.nasonline.org/SACKLER_cooperation.
