title: Temperate phages promote colicin-dependent fitness of Salmonella enterica serovar Typhimurium.
abstract: Bacteria employ bacteriocins for interference competition in microbial ecosystems. Colicin Ib (ColIb), a pore-forming bacteriocin, confers a significant fitness benefit to Salmonella enterica serovar Typhimurium (S. Tm) in competition against commensal Escherichia coli in the gut. ColIb is released from S. Tm into the environment, where it kills susceptible competitors. However, colicin-specific release proteins, as they are known for other colicins, have not been identified in case of ColIb. Thus, its release mechanism has remained unclear. In the current study, we have established a new link between ColIb release and lysis activity of temperate, lambdoid phages. By the use of phage-cured S. Tm mutant strains, we show that the presence of temperate phages and their lysis genes is necessary and sufficient for release of active ColIb into the culture supernatant. Furthermore, phage-mediated lysis significantly enhanced S. Tm fitness in competition against a ColIb-susceptible competitor. Finally, transduction with the lambdoid phage 933W rescued the defect of E. coli strain MG1655 with respect to ColIb release. In conclusion, ColIb is released from bacteria in the course of phage lysis. Our data reveal a new mechanism for colicin release and point out a novel function of temperate phages in enhancing colicin-dependent bacterial fitness.
authors.affiliation: Max-von-Pettenkofer Institute, LMU Munich, Pettenkoferstr. 9a, 80336, Munich, Germany.
authors.forename: Lubov P
authors.initials: LP
authors.lastname: Nedialkova
authors.affiliation: Max-von-Pettenkofer Institute, LMU Munich, Pettenkoferstr. 9a, 80336, Munich, Germany.
authors.forename: Maja
authors.initials: M
authors.lastname: Sidstedt
authors.affiliation: Max-von-Pettenkofer Institute, LMU Munich, Pettenkoferstr. 9a, 80336, Munich, Germany.|German Center for Infection Research (DZIF), partner site LMU Munich, Munich, Germany.
authors.forename: Martin B
authors.initials: MB
authors.lastname: Koeppel
authors.affiliation: Max-von-Pettenkofer Institute, LMU Munich, Pettenkoferstr. 9a, 80336, Munich, Germany.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Spriewald
authors.affiliation: Max-von-Pettenkofer Institute, LMU Munich, Pettenkoferstr. 9a, 80336, Munich, Germany.|German Center for Infection Research (DZIF), partner site LMU Munich, Munich, Germany.
authors.forename: Diana
authors.initials: D
authors.lastname: Ring
authors.affiliation: Wernigerode Branch, Robert Koch Institute, Project Group 5, Burgstr. 37, 38855, Wernigerode, Germany.
authors.forename: Roman G
authors.initials: RG
authors.lastname: Gerlach
authors.affiliation: CNRS, Centre de Genetique Moleculaire, Gif-sur-Yvette Cedex, 91198, France.
authors.forename: Lionello
authors.initials: L
authors.lastname: Bossi
authors.affiliation: Max-von-Pettenkofer Institute, LMU Munich, Pettenkoferstr. 9a, 80336, Munich, Germany.|German Center for Infection Research (DZIF), partner site LMU Munich, Munich, Germany.
authors.forename: Bärbel
authors.initials: B
authors.lastname: Stecher
mesh_terms: D001435:Bacteriophages / Q000502:physiology*; D003087:Colicins / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000821:virology; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D056084:Genetic Fitness; D012486:Salmonella typhimurium / Q000235:genetics / Q000378:metabolism / Q000821:virology*; D065288:Serogroup
chemical_list: D003087:Colicins