title: Early steps in the European eel (Anguilla anguilla)-Vibrio vulnificus interaction in the gills: role of the RtxA13 toxin.
abstract: Vibrio vulnificus is an aquatic gram-negative bacterium that causes a systemic disease in eels called warm-water vibriosis. Natural disease occurs via water born infection; bacteria attach to the gills (the main portal of entry) and spread to the internal organs through the bloodstream, provoking host death by haemorrhagic septicaemia. V. vulnificus produces a toxin called RtxA13 that hypothetically interferes with the eel immune system facilitating bacterial invasion and subsequent death by septic shock. The aim of this work was to study the early steps of warm-water vibriosis by analysing the expression of three marker mRNA transcripts related to pathogen recognition (tlr2 and tlr5) and inflammation (il-8) in the gills of eels infected by immersion with either the pathogen or a mutant deficient in rtxA13. Results indicate a differential response that is linked to the rtx toxin in the expression levels of the three measured mRNA transcripts. The results suggest that eels are able to distinguish innocuous from harmful microorganisms by the local action of their toxins rather than by surface antigens. Finally, the cells that express these transcripts in the gills are migratory cells primarily located in the second lamellae that re-locate during infection suggesting the activation of a specific immune response to pathogen invasion in the gill.
authors.affiliation: ERI BIOTEDCMED, Universitat de Valencia, Spain; Departament de Microbiologia i Ecologia, Universitat de Valencia, Spain; Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Spain.
authors.forename: Agnès
authors.initials: A
authors.lastname: Callol
authors.affiliation: ERI BIOTEDCMED, Universitat de Valencia, Spain; Departament de Microbiologia i Ecologia, Universitat de Valencia, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Pajuelo
authors.affiliation: Department of Biology, University of Bergen, Norway.
authors.forename: Lars
authors.initials: L
authors.lastname: Ebbesson
authors.affiliation: Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Spain; Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, Spain.
authors.forename: Mariana
authors.initials: M
authors.lastname: Teles
authors.affiliation: Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Spain; Institute of Aquaculture, University of Stirling, UK.
authors.forename: Simon
authors.initials: S
authors.lastname: MacKenzie
authors.affiliation: ERI BIOTEDCMED, Universitat de Valencia, Spain; Departament de Microbiologia i Ecologia, Universitat de Valencia, Spain. Electronic address: carmen.amaro@uv.es.
authors.forename: Carmen
authors.initials: C
authors.lastname: Amaro
mesh_terms: D000811:Anguilla; D000818:Animals; D001427:Bacterial Toxins / Q000494:pharmacology*; D018925:Chemokines / Q000235:genetics / Q000378:metabolism; D005393:Fish Diseases / Q000235:genetics / Q000276:immunology* / Q000382:microbiology; D005786:Gene Expression Regulation; D005880:Gills / Q000276:immunology / Q000382:microbiology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014735:Vibrio Infections / Q000235:genetics / Q000276:immunology / Q000382:microbiology / Q000662:veterinary*; D041261:Vibrio vulnificus / Q000502:physiology*
chemical_list: D001427:Bacterial Toxins; D018925:Chemokines; D012333:RNA, Messenger
keywords: European eel; Host-pathogen relationship; Immune response; Vibrio vulnificus; rtxA1(3)