title: Escherichia coli isolate for studying colonization of the mouse intestine and its application to two-component signaling knockouts.
abstract: The biology of Escherichia coli in its primary niche, the animal intestinal tract, is remarkably unexplored. Studies with the streptomycin-treated mouse model have produced important insights into the metabolic requirements for Escherichia coli to colonize 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, MP1, isolated from a mouse. MP1 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 MP1 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 critical requirement for E. coli colonization of the mouse intestine. We also show that the response regulator OmpR, which had previously been hypothesized to be important for adaptation between in vivo and ex vivo environments, is not required for MP1 colonization due to the presence of a third major porin.
authors.affiliation: Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: Melissa
authors.initials: M
authors.lastname: Lasaro
authors.forename: Zhi
authors.initials: Z
authors.lastname: Liu
authors.forename: Rima
authors.initials: R
authors.lastname: Bishar
authors.forename: Kathryn
authors.initials: K
authors.lastname: Kelly
authors.forename: Sujay
authors.initials: S
authors.lastname: Chattopadhyay
authors.forename: Sandip
authors.initials: S
authors.lastname: Paul
authors.forename: Evgeni
authors.initials: E
authors.lastname: Sokurenko
authors.forename: Jun
authors.initials: J
authors.lastname: Zhu
authors.forename: Mark
authors.initials: M
authors.lastname: Goulian
mesh_terms: D000818:Animals; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics* / Q000254:growth & development* / Q000302:isolation & purification / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D055786:Gene Knockout Techniques; D007413:Intestinal Mucosa / Q000382:microbiology*; D051379:Mice; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; C489568:RcsB protein, E coli; D012097:Repressor Proteins; D014157:Transcription Factors; C041610:arcA protein, E coli; C085504:CpxR protein, Bacteria