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When and where? Pathogenic Escherichia coli differentially sense host D-serine using a universal transporter system to monitor their environment

Lookup NU author(s): Dr James ConnollyORCiD



This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).


© 2016 Connolly and Roe. Sensing environmental stimuli is critically important for bacteria when faced with the multitude of adversities presented within the host. Responding appropriately to these signals and in turn integrating these responses into the regulatory network of the cell allows bacteria to control precisely when and where they should establish colonization. D-serine is an abundant metabolite of the human urinary tract but is a toxic metabolite for Escherichia coli that lack a D-serine tolerance locus. Enterohaemorrhagic E. coli (EHEC) cannot catabolize D-serine for this reason and colonize the large intestine specifically, an environment low in D-serine. EHEC can however use D-serine sensing to repress colonization thus signaling the presence of an unfavorable environment. In our recent work (Connol-ly, et al. PLoS Pathogens (2016) 12(1): e1005359), we describe the discovery of a functional and previously uncharacterized D-serine uptake system in E. coli. The genes identified are highly conserved in all E. coli lineages but are regulated differentially in unique pathogenic backgrounds. The study identified that EHEC, counter-intuitively, increase D-serine uptake in its presence but that this is a tolerated process and is used to increase the transcriptional response to this signal. It was also found that the system has been integrated into the transcriptional network of EHEC-specific virulence genes, demonstrating an important pathotype-specific adaptation of core genome components.

Publication metadata

Author(s): Connolly JPR, Roe AJ

Publication type: Review

Publication status: Published

Journal: Microbial Cell

Year: 2016

Volume: 3

Issue: 4

Pages: 181-184

Print publication date: 01/04/2016

Online publication date: 31/03/2016

Acceptance date: 22/02/2016

ISSN (electronic): 2311-2638

Publisher: Shared Science Publishers OG


DOI: 10.15698/mic2016.04.494