Flagellar interference with plasmid uptake in biofilms: a joint experimental and modeling study.

Autor:	Røder HL; Department of Food Science, University of Copenhagen, Copenhagen, Denmark.; Department of Biology, University of Copenhagen, Copenhagen, Denmark., Christidi E; School of Biosciences & Institute of Microbiology and Infection & Centre for Computational Biology, University of Birmingham, Edgbaston, Birmingham, United Kingdom., Amador CI; Department of Biology, University of Copenhagen, Copenhagen, Denmark., Music S; Department of Biology, University of Copenhagen, Copenhagen, Denmark., Olesen AK; Department of Biology, University of Copenhagen, Copenhagen, Denmark., Svensson B; Department of Biotechnology and Biomedicine, Technical University of Denmark, Kgs. Lyngby, Denmark., Madsen JS; Department of Biology, University of Copenhagen, Copenhagen, Denmark., Herschend J; Department of Biology, University of Copenhagen, Copenhagen, Denmark., Kreft J-U; School of Biosciences & Institute of Microbiology and Infection & Centre for Computational Biology, University of Birmingham, Edgbaston, Birmingham, United Kingdom., Burmølle M; Department of Biology, University of Copenhagen, Copenhagen, Denmark.
Jazyk:	angličtina
Zdroj:	Applied and environmental microbiology [Appl Environ Microbiol] 2024 Jan 24; Vol. 90 (1), pp. e0151023. Date of Electronic Publication: 2023 Dec 14.
DOI:	10.1128/aem.01510-23
Abstrakt:	Plasmid conjugation is a key facilitator of horizontal gene transfer (HGT), and plasmids encoding antibiotic resistance drive the increasing prevalence of antibiotic resistance. In natural, engineered, and clinical environments, bacteria often grow in protective biofilms. Therefore, a better understanding of plasmid transfer in biofilms is needed. Our aim was to investigate plasmid transfer in a biofilm-adapted wrinkly colony mutant of Xanthomonas retroflexus (XRw) with enhanced matrix production and reduced motility. We found that XRw biofilms had an increased uptake of the broad host-range IncP-1ϵ plasmid pKJK5 compared to the wild type (WT). Proteomics revealed fewer flagellar-associated proteins in XRw, suggesting that flagella were responsible for reducing plasmid uptake. This was confirmed by the higher plasmid uptake of non-flagellated fliM mutants of the X. retroflexus wrinkly mutant as well as the wild type. Moreover, testing several flagellar mutants of Pseudomonas putida suggested that the flagellar effect was more general. We identified seven mechanisms with the potential to explain the flagellar effect and simulated them in an individual-based model. Two mechanisms could thus be eliminated (increased distances between cells and increased lag times due to flagella). Another mechanism identified as viable in the modeling was eliminated by further experiments. The possibility of steric hindrance of pilus movement and binding by flagella, reducing the frequency of contact and thus plasmid uptake, proved viable, and the three other viable mechanisms had a reduced probability of plasmid transfer in common. Our findings highlight the important yet complex effects of flagella during bacterial conjugation in biofilms.IMPORTANCEBiofilms are the dominant form of microbial life and bacteria living in biofilms are markedly different from their planktonic counterparts, yet the impact of the biofilm lifestyle on horizontal gene transfer (HGT) is still poorly understood. Horizontal gene transfer by conjugative plasmids is a major driver in bacterial evolution and adaptation, as exemplified by the troubling spread of antibiotic resistance. To either limit or promote plasmid prevalence and dissemination, we need a better understanding of plasmid transfer between bacterial cells, especially in biofilms. Here, we identified a new factor impacting the transfer of plasmids, flagella, which are required for many types of bacterial motility. We show that their absence or altered activity can lead to enhanced plasmid uptake in two bacterial species, Xanthomonas retroflexus and Pseudomonas putida . Moreover, we demonstrate the utility of mathematical modeling to eliminate hypothetical mechanisms. Competing Interests: The authors declare no conflict of interest.
Databáze:	MEDLINE
Externí odkaz:	Zobrazit plný text záznamu