1. Escherichia coli Isolat e for Studying Colonization of the Mouse Intestine and Its Application to Two-Component Signaling Knockouts.
- Author
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Lasaro, Melissa, Zhi Liu, Bishar, Rima, Kelly, Kathryn, Chattopadhyay, Sujay, Paul, Sandip, Sokurenko, Evgeni, Jun Zhu, and Goulian, Mark
- Subjects
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ESCHERICHIA coli , *COLONIZATION (Ecology) , *LABORATORY mice , *CELLULAR signal transduction , *ECOLOGICAL niche , *ANAEROBIOSIS - Abstract
The biology of Escherichia coli in its primary niche, the animal intestinal tract, is remarkably unexplored. Studies with the strep-tomycin-treated mouse model have produced important insights into the metabolic requirements for Escherichia coli to colo-nize mice. However, we still know relatively little about the physiology of this bacterium growing in the complex environment of an intestine that is permissive for the growth of competing flora. We have developed a system for studying colonization using an E. coli strain, MPI, isolated from a mouse. MPI is genetically tractable and does not require continuous antibiotic treatment for stable colonization. As an application of this system, we separately knocked out each two-component system response regulator in MPI and performed competitions against the wild-type strain. We found that only three response regulators, ArcA, CpxR, and RcsB, produce strong colonization defects, suggesting that in addition to anaerobiosis, adaptation to cell envelope stress is a crit-ical requirement for E. coli colonization of the mouse intestine. We also show that the response regulator OmpR, which had pre-viously been hypothesized to be important for adaptation between in vivo and ex vivo environments, is not required for MPI colonization due to the presence of a third major porin. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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