Starving bacteria fight antibiotics harder?

_{Denyse O'Leary

November 18, 2011

Cell biology, News}

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It sounds counterintuitive, but see:

Science 18 November 2011, Vol. 334 no. 6058 pp. 982-986

ABSTRACT: Bacteria become highly tolerant to antibiotics when nutrients are limited. The inactivity of antibiotic targets caused by starvation-induced growth arrest is thought to be a key mechanism producing tolerance. Here we show that the antibiotic tolerance of nutrient-limited and biofilm Pseudomonas aeruginosa is mediated by active responses to starvation, rather than by the passive effects of growth arrest. The protective mechanism is controlled by the starvation-signaling stringent response (SR), and our experiments link SR-mediated tolerance to reduced levels of oxidant stress in bacterial cells. Furthermore, inactivating this protective mechanism sensitized biofilms by several orders of magnitude to four different classes of antibiotics and markedly enhanced the efficacy of antibiotic treatment in experimental infections.

See also: Antibiotic resistance is ancient.

Comments

More fitting song;
Chris Tomlin - The Way I Was Made http://www.youtube.com/watch?v=VF5SZWox_JE
bornagain77_{November 18, 2011
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Reminds me of this study that demonstrated that bacteria which gained antibiotic resistance by mutation are less fit than wild type bacteria::
Testing the Biological Fitness of Antibiotic Resistant Bacteria - 2008 Excerpt: Therefore, in order to simulate competition in the wild, bacteria must be grown on minimal media. Minimal media mimics better what bacteria experience in a natural environment over a period of time. This is the place where fitness can be accurately assessed. Given a rich media, they grow about the same. http://www.answersingenesis.org/articles/aid/v2/n1/darwin-at-drugstore
Notes:
Is Antibiotic Resistance evidence for evolution? - 'The Fitness Test' - video http://www.metacafe.com/watch/3995248 List Of Degraded Molecular Abilities Of Antibiotic Resistant Bacteria: http://www.trueorigin.org/bacteria01.asp “The First Rule of Adaptive Evolution”: Break or blunt any functional coded element whose loss would yield a net fitness gain - Michael Behe - December 2010 Excerpt: In its most recent issue The Quarterly Review of Biology has published a review by myself of laboratory evolution experiments of microbes going back four decades.,,, The gist of the paper is that so far the overwhelming number of adaptive (that is, helpful) mutations seen in laboratory evolution experiments are either loss or modification of function. Of course we had already known that the great majority of mutations that have a visible effect on an organism are deleterious. Now, surprisingly, it seems that even the great majority of helpful mutations degrade the genome to a greater or lesser extent.,,, I dub it “The First Rule of Adaptive Evolution”: Break or blunt any functional coded element whose loss would yield a net fitness gain.(that is a net 'fitness gain' within a 'stressed' environment i.e. remove the stress from the environment and the parent strain is always more 'fit') http://behe.uncommondescent.com/2010/12/the-first-rule-of-adaptive-evolution/
verse and music:
Matthew 5:48, “be you perfect as also your heavenly Father is perfect.” i.e. He does not lack any perfection and thus creates perfectly. i.e. any 'natural' change from his initial creative act, from a Theistic point of view, will necessitate a move from that initial perfect creative act of His. High School Musical 2 - You are the music in me http://www.youtube.com/watch?v=IAXaQrh7m1o
bornagain77_{November 18, 2011
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