title: Mechanisms of Bacterial (Serratia marcescens) Attachment to, Migration along, and Killing of Fungal Hyphae.
abstract: We have found a remarkable capacity for the ubiquitous Gram-negative rod bacterium Serratia marcescens to migrate along and kill the mycelia of zygomycete molds. This migration was restricted to zygomycete molds and several basidiomycete species. No migration was seen on any molds of the phylum Ascomycota. S. marcescens migration did not require fungal viability or surrounding growth medium, as bacteria migrated along aerial hyphae as well.S. marcescens did not exhibit growth tropism toward zygomycete mycelium. Bacterial migration along hyphae proceeded only when the hyphae grew into the bacterial colony. S. marcescens cells initially migrated along the hyphae, forming attached microcolonies that grew and coalesced to generate a biofilm that covered and killed the mycelium. Flagellum-defective strains of S. marcescens were able to migrate along zygomycete hyphae, although they were significantly slower than the wild-type strain and were delayed in fungal killing. Bacterial attachment to the mycelium does not necessitate type 1 fimbrial adhesion, since mutants defective in this adhesin migrated equally well as or faster than the wild-type strain. Killing does not depend on the secretion of S. marcescens chitinases, as mutants in which all three chitinase genes were deleted retained wild-type killing abilities. A better understanding of the mechanisms by which S. marcescens binds to, spreads on, and kills fungal hyphae might serve as an excellent model system for such interactions in general; fungal killing could be employed in agricultural fungal biocontrol.
authors.affiliation: Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel.
authors.forename: Tal
authors.initials: T
authors.lastname: Hover
authors.affiliation: Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel.
authors.forename: Tal
authors.initials: T
authors.lastname: Maya
authors.affiliation: Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel.
authors.forename: Sapir
authors.initials: S
authors.lastname: Ron
authors.affiliation: Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel.
authors.forename: Hani
authors.initials: H
authors.lastname: Sandovsky
authors.affiliation: Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel.
authors.forename: Yana
authors.initials: Y
authors.lastname: Shadkchan
authors.affiliation: Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel.
authors.forename: Nitzan
authors.initials: N
authors.lastname: Kijner
authors.affiliation: Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel.
authors.forename: Yulia
authors.initials: Y
authors.lastname: Mitiagin
authors.affiliation: Faculty of Medicine in the Galilee, Bar-Ilan University, Safed, Israel.
authors.forename: Boris
authors.initials: B
authors.lastname: Fichtman
authors.affiliation: Faculty of Medicine in the Galilee, Bar-Ilan University, Safed, Israel.
authors.forename: Amnon
authors.initials: A
authors.lastname: Harel
authors.affiliation: Charles T. Campbell Microbiology Laboratory, Department of Ophthalmology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA.
authors.forename: Robert M Q
authors.initials: RM
authors.lastname: Shanks
authors.affiliation: Instituto de Biología Molecular y Celular de Rosario (IBR), Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de Rosario, Rosario, Argentina.
authors.forename: Roberto E
authors.initials: RE
authors.lastname: Bruna
authors.affiliation: Instituto de Biología Molecular y Celular de Rosario (IBR), Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de Rosario, Rosario, Argentina.
authors.forename: Eleonora
authors.initials: E
authors.lastname: García-Véscovi
authors.affiliation: Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel nosherov@post.tau.ac.il.
authors.forename: Nir
authors.initials: N
authors.lastname: Osherov
mesh_terms: D000898:Antibiosis / Q000502:physiology; D001422:Bacterial Adhesion / Q000502:physiology; D018441:Biofilms / Q000254:growth & development*; D002688:Chitinases / Q000235:genetics / Q000378:metabolism; D010861:Fimbriae, Bacterial; D005407:Flagella / Q000235:genetics / Q000502:physiology; D005658:Fungi / Q000166:cytology / Q000502:physiology*; D054884:Host-Pathogen Interactions; D025301:Hyphae / Q000166:cytology / Q000502:physiology; D050296:Microbial Viability; D009154:Mutation; D025282:Mycelium / Q000166:cytology / Q000502:physiology; D010572:Pest Control, Biological; D012233:Rhizopus / Q000166:cytology / Q000502:physiology; D012706:Serratia marcescens / Q000166:cytology / Q000502:physiology*
chemical_list: D002688:Chitinases