ORIGINAL RESEARCH article
Front. Microbiol.
Sec. Phage Biology
Volume 16 - 2025 | doi: 10.3389/fmicb.2025.1588121
Escherichia coli Group 2 capsules and their interplay with bacteriophages
Provisionally accepted
- Trinity College Dublin, Dublin, Ireland
Select one of your emails
You have multiple emails registered with Frontiers:
Notify me on publication
Please enter your email address:
If you already have an account, please login
You don't have a Frontiers account ? You can register here
Extracellular polysaccharide capsules of Gram-negative bacteria such as Escherichia coli (E. coli) modulate the interactions of bacterial cells with a myriad of threats, including the complement system and bacteriophage (phage). Some phage need to target other surface factors in order to overcome the K capsule barrier. Alternatively, capsules may be required for phage infection. In those instances, interaction of phage receptor binding proteins coupled with enzymatic degradation or modification of the K capsule by capsule depolymerases is followed by phage infection. This study has found that the Group 2, K2 capsule of an extra-intestinal pathogenic E. coli (ExPEC) prototype can serve as both a barrier in preventing phage infection, as well as act as a receptor. Additionally, in the ExPEC prototype CFT073, a novel synergy between capsule expression and a type IV toxin-antitoxin system was observed. The co-location of these systems was shown to be present in over 500 other E. coli genomes, indicating a conserved relationship between capsules and the TA system. It was then shown that these genes are co-acquired horizontally on a pathogenicity island common to ExPEC and may have played a key role in the evolution of these pathogens.
Keywords: Escherichia coli, ExPEC, Bacteriophage, Capsule, lipopolysaccharide, LPS, Polysaccharides, Phage
Received: 05 Mar 2025; Accepted: 29 Aug 2025.
Copyright: © 2025 McGarry, Toner-Bartelds and Smith. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Naoise McGarry, Trinity College Dublin, Dublin, Ireland
Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.