Session A27: Evolutionary and Ecological Systems
8:00 AM–11:00 AM, Monday, March 15, 2010
Room: D137
Sponsoring Unit:
DBP
Chair: Jeff Gore, Massachusetts Institute of Technology
Abstract ID: BAPS.2010.MAR.A27.6
Abstract: A27.00006 : Growth mediated feedback and the abrupt onset of antibiotic resistance
9:00 AM–9:12 AM
Preview Abstract
MathJax On | Off 
Abstract 
Author:
J. Barrett Deris
(Center for Theoretical Biological Physics, UCSD)
Recent results in our lab indicate that global gene expression will change in a growth-dependent manner for bacteria in sublethal antibiotic levels. We analyzed a system containing a constitutively expressed drug resistance gene and found that growth-mediated feedback provided a mechanism for bistable growth rates. That is, two identical cell-lines in the same antibiotic-infused media may respond with distinct growth rates. Our experimental work with cells carrying this resistance gene has shown that a rapid drop in growth occurs over a relatively small range of antibiotic. This result is consistent with a growth plateau arising in our analysis of the feedback mechanism. Furthermore, experiments have shown that a culture's degree of drug resistance depends on the initial growth conditions prior to exposure to high levels of antibiotics. This result is consistent with the predicted existence of a hysteretic regime near the growth plateau. The work reveals concrete mechanisms by which bacteria cope with high levels of antibiotics and illustrates the importance of considering growth-mediated feedback on gene circuits.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2010.MAR.A27.6