title: New aspects in the biology of Photobacterium damselae subsp. piscicida: pili, motility and adherence to solid surfaces.
abstract: We describe for the first time the presence of pilus-like structures on the surface of Photobacterium damselae subsp. piscicida (Phdp). The hint to this discovery was the ability of one strain to hemagglutinate human erythrocytes. Further analysis of several Phdp strains ultrastructure by electron microscopy revealed the presence of long, thin fibers, similar to pili of other Gram-negative bacteria. These appendages were also observed and photographed by scanning, transmission electron microscopy and immunofluorescence. Although this fish pathogen has been described as non-motile, all strains tested exhibit twitching motility, a flagella-independent type IV-dependent form of bacterial translocation over surfaces. As far as we are aware, the movement of Phdp bacteria on semi-solid or solid surfaces has not been described previously. Moreover, we speculate that Phdp twitching motility may be involved in biofilm formation. Microscopic examination of Phdp biofilms by microscopy revealed that Phdp biofilm architecture display extensive cellular chaining and also bacterial mortality during biofilm formation in vitro. Based on our results, standardized analyses of Phdp surface appendages, biofilms, motility and their impact on Phdp survival, ecology and pathobiology are now feasible.
authors.affiliation: Servicio de Microbiología, Hospital Universitario Marqués de Valdecilla, Instituto de Investigación Marqués de Valdecilla IDIVAL, Santander, Cantabria, Spain.
authors.forename: Sara
authors.initials: S
authors.lastname: Remuzgo-Martínez
authors.affiliation: Servicio de Microbiología, Hospital Universitario Marqués de Valdecilla, Instituto de Investigación Marqués de Valdecilla IDIVAL, Santander, Cantabria, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Lázaro-Díez
authors.affiliation: Instituto Universitario de Sanidad Animal, Universidad de Las Palmas de Gran Canaria, Arucas, Spain.
authors.forename: Daniel
authors.initials: D
authors.lastname: Padilla
authors.affiliation: Instituto Universitario de Sanidad Animal, Universidad de Las Palmas de Gran Canaria, Arucas, Spain.
authors.forename: Belinda
authors.initials: B
authors.lastname: Vega
authors.affiliation: Instituto Universitario de Sanidad Animal, Universidad de Las Palmas de Gran Canaria, Arucas, Spain.
authors.forename: Fátima
authors.initials: F
authors.lastname: El Aamri
authors.affiliation: Departamento de Anatomía y Biología Celular, Universidad de Cantabria, Santander, Cantabria, Spain.
authors.forename: José Manuel
authors.initials: JM
authors.lastname: Icardo
authors.affiliation: Instituto Universitario de Sanidad Animal, Universidad de Las Palmas de Gran Canaria, Arucas, Spain.
authors.forename: Félix
authors.initials: F
authors.lastname: Acosta
authors.affiliation: Servicio de Microbiología, Hospital Universitario Marqués de Valdecilla, Instituto de Investigación Marqués de Valdecilla IDIVAL, Santander, Cantabria, Spain. Electronic address: jvivas@idival.org.
authors.forename: José
authors.initials: J
authors.lastname: Ramos-Vivas
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion / Q000502:physiology*; D018441:Biofilms / Q000254:growth & development*; D010861:Fimbriae, Bacterial / Q000502:physiology* / Q000648:ultrastructure; D005399:Fishes / Q000382:microbiology*; D005455:Fluorescent Antibody Technique / Q000662:veterinary; D006386:Hemagglutination Tests / Q000662:veterinary; D006801:Humans; D018613:Microscopy, Confocal / Q000662:veterinary; D008855:Microscopy, Electron, Scanning / Q000662:veterinary; D046529:Microscopy, Electron, Transmission / Q000662:veterinary; D009068:Movement / Q000502:physiology; D010776:Photobacterium / Q000502:physiology*
keywords: Biofilm; Motility; Photobacterium damselae subsp. Piscicida; Pili