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Molecular mechanisms in the prey exit process of pathogen-predator Bdellovibrio bacteriovorus

English title Molecular mechanisms in the prey exit process of pathogen-predator Bdellovibrio bacteriovorus
Applicant Huwiler Simona
Number 194432
Funding scheme Return CH Postdoc.Mobility
Research institution Institut für Pflanzen- und Mikrobiologie Universität Zürich
Institution of higher education University of Zurich - ZH
Main discipline Molecular Biology
Start/End 01.02.2021 - 31.05.2021
Approved amount 37'700.00
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All Disciplines (4)

Discipline
Molecular Biology
Biochemistry
Genetics
Experimental Microbiology

Keywords (5)

Bdellovibrio bacteriovorus; predatory life cycle; predatory bacterium; lysis; (Para-) Burkholderia

Lay Summary (German)

Lead
Bdellovibrio bacteriovorus ist ein räuberisches Bakterium welches andere Bakterien, wie zum Beispiel pathogene Burkholderien oder nützliche Paraburkholderien, vernichtet. Ein Paraburkholderia Bakterium scheint nicht so sensitiv gegenüber B. bacteriovorus zu sein wie andere Stämme, wobei begonnen wurde nach möglichen Resistenzmechanismen zu suchen. Zudem wurden Mechanismen in der letzten Phase des räuberhaften Lebenszyklus’ untersucht, was im Rahmen des anschliessenden Ambizione-Stipendiums fortgeführt wird.
Lay summary

Das räuberhafte Bakterium Bdellovibrio bacteriovorus tötet andere Gram-negative Beute-Bakterien, vermehrt sich innerhalb der Beute und verlässt am Ende die Beutereste wieder. In dieser Studie wurden mikroskopische Studien zur Untersuchung von Faktoren, die in dieser letzten Lebenszyklus-Phase involviert sind fortgeführt und werden im Anschluss in einem Ambizione weitergeführt.

Zudem werden erste Versuche gemacht um zu untersuchen, ob es pathogene Burkholderia oder Stickstoff-fixierende Paraburkholderia Stämme gibt, die gegen B. bacteriovorus resistent sind. Das Stickstoff-fixierende Pflanzen-symbiontische Bakterium Paraburkholderia phymatum scheint weniger sensitiv gegenüber B. bacteriovorus als andere Stämme. Erste Experimente deuten darauf hin, dass in diesem Prozess keine sekretierten Substanzen von P. phymatum involviert sind.

Für die Nutzung von B. bacteriovorus ist es wichtig, mögliche Schutzmechanismen der Beutebakterien zu erforschen und kennen, sowie detailliertere Einsichten in die molekularen Mechanismen der räuberhaften Bakterien zu gewinnen.

Direct link to Lay Summary Last update: 11.07.2021

Responsible applicant and co-applicants

Employees

Collaboration

Group / person Country
Types of collaboration
Prof. Leo Eberl/Institute of Plant and Microbial Biology, University of Zurich Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Research Infrastructure
Dr. Gabriella Pessi/Institute of Plant and Microbial Biology, University of Zurich, Switzerland Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Research Infrastructure

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
Life Science Switzerland LS2 Annual Meeting 2021 Talk given at a conference Specific lysis of prey peptidoglycan enabling predatory bacterium Bdellovibrio bacteriovorus to exit from its host bacterium 17.02.2021 Online, Switzerland Huwiler Simona;
Life Science Switzerland LS2 Annual Meeting 2021 Poster Specific lysis of prey peptidoglycan enabling predatory bacterium Bdellovibrio bacteriovorus to exit from its host bacterium 17.02.2021 Online, Switzerland Huwiler Simona;


Associated projects

Number Title Start Funding scheme
193401 Learning from predatory bacteria: from ‘omics’ to molecular mechanisms 01.06.2021 Ambizione
183896 Key signals and effects in the prey exit process of predatory bacterium Bdellovibrio bacteriovorus 01.08.2019 Postdoc.Mobility

Abstract

Background:Bdellovibrio bacteriovorus is a Gram-negative predatory bacterium which is a model organism for predatory bacteria that invade and replicate in the periplasm of other Gram-negative prey bacteria. When resources run out, predator progeny cells exit the exhausted prey cell. Such predation occurs naturally in soils and waters and has potential as an antibacterial technology. McNeely et al. (1) reported that many clinical strains of Burkholderia cepacia complex are susceptible to predation by B. bacteriovorus, whereas a small fraction of strains is resistant.Objectives:Up to now, the prey exit process of B. bacteriovorus and its molecular mechanisms that damage the prey cell wall and prey outer membrane are barely understood. This project continues ongoing investigations on these molecular mechanisms started at University of Nottingham (UK). Further, initial experiments in collaboration with Prof. Dr. Leo Eberl and Dr. Gabriella Pessi (University of Zurich) starts to address causes of resistance of different Para-/Burkholderia strains against predation by B. bacteriovorus. Methods:To investigate the molecular mechanism of the exit process four B. bacteriovorus deletion mutant strains, for genes that I found were highly up-regulated in the exit phase, were tested microscopically for exit phenotypes. Different Para-/Burkholderia strains were tested towards susceptibility of predation by B. bacteriovorus.Results and value of the proposed project:Due to the rise of antibiotic-resistant pathogenic bacterial strains the investigation of the natural pathogen-predator B. bacteriovorus is of importance. In these investigations it was found that one Paraburkholderia strain, which is a nitrogen-fixing plant symbiont, is less susceptible towards B. bacteriovorus than other strains. Initial experiments indicate that likely no secreted substances in the supernatant of the attacked Paraburkholderia strain are involved. Further investigations into this could reveal resistance mechanisms that prey bacteria might have towards predatory bacteria. Research on the prey exit mechanisms of B. bacteriovorus will be continued in the subsequent Ambizione fellowship, hoping to reveal potential bacterial envelop targeting/damaging processes. Both aspects will contribute to our general knowledge on predator-prey interactions.Reference: 1. McNeely, D., Chanyi, R. M., Dooley, J. S., Moore, J. E. & Koval, S. F. Can J Microbiol 63, 350-358, 2017.
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