FlhF(T368A) modulates motility in the bacteriophage carrier state of Campylobacter jejuni

Liang, Lu; Connerton, Ian F.

Abstract

© 2018 The Authors. Molecular Microbiology Published by John Wiley & Sons Ltd. The carrier state is an alternative bacteriophage life cycle by which virulent bacteriophage can persist in association with host bacteria. Campylobacter jejuni carrier state strains exhibit growth phase dependent motility due to a truncated flagella phenotype. Genome sequencing identified a T368A substitution in the G3 domain of the SRP-like GTPase FlhF from C. jejuni PT14CP30A carrier state strains, which we hypothesized to be the cause of the complex motility phenotype. We have analyzed the role of this mutation in C. jejuni PT14 and demonstrated that flhF(T368A) leads to a large proportion of cells unable to synthesize flagella, while the remaining cells form a single flagellum at one pole leading to significantly reduced motility. The flhF(T368A) mutation causes a reduction in the phage adsorption constant, which leads to a decrease in infection efficiency. Down-regulation of σ28 and σ54 dependent flagellar genes were observed as responses to the flhF(T368A) mutation. FlhF(T368A) protein is impaired in GTPase activity and exhibits reduced stability. C. jejuni carrying flhF(T368A) are less sensitive to bacteriophage infection and formation of the carrier state. The acquisition of flhF(T368A) in carrier state strains acts to prevent super-infection and maintain association with the bacteriophage that provoked the interaction.

Citation

Liang, L., & Connerton, I. F. (2018). FlhF(T368A) modulates motility in the bacteriophage carrier state of Campylobacter jejuni. Molecular Microbiology, 110(4), 616-633. https://doi.org/10.1111/mmi.14120

• Journal Article Type: Article
• Acceptance Date: Sep 5, 2018
• Online Publication Date: Oct 23, 2018
• Publication Date: 2018-11
• Deposit Date: Sep 12, 2018
• Publicly Available Date: Feb 14, 2019
• Journal: Molecular Microbiology
• Print ISSN: 0950-382X
• Electronic ISSN: 1365-2958
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 110
• Issue: 4
• Pages: 616-633
• DOI: https://doi.org/10.1111/mmi.14120
• Keywords: Campylobacter, bacteriophage, carrier state life cycle, FlhF, motility
• Public URL: https://nottingham-repository.worktribe.com/output/1070776
• Publisher URL: https://onlinelibrary.wiley.com/doi/abs/10.1111/mmi.14120
• Contract Date: Feb 14, 2019