title: Inhibition of fish pathogens by the microbiota from rainbow trout (Oncorhynchus mykiss, Walbaum) and rearing environment.
abstract: This work reports the isolation and taxonomic identification of the cultivable total microbiota (TM) and Lactic Acid Bacteria (LAB) from rainbow trout (Oncorhynchus mykiss, Walbaum) and rearing environment from selected stages of the life-cycle, and the evaluation of the LAB antimicrobial activity against the main fish pathogens. TM and LAB isolates were randomly selected and identified by 16S rRNA and/or superoxide dismutase gene sequencing. Although a great diversity in the TM was observed, Enterobacteriaceae and Aeromonadaceae were clearly prevalent, while the genus Lactococcus was the predominant LAB. From a total of 1620 randomly selected LAB, 1159 isolates (71.5%) showed antimicrobial activity. From these, 248 isolates (21.4%) selected for their activity against, at least, four fish pathogens, were taxonomically identified, being Lactococcus lactis the most common species (164 isolates, 66.1%). Interestingly, 88 isolates (35.5%), including 55 L. lactis isolates, exerted activity against four strains of the rainbow trout pathogen Lactococcus garvieae. Our results demonstrate that rainbow trout and rearing environment are potential sources for the isolation of LAB, mainly lactococci, active against L. garvieae and other fish pathogens. Moreover, this is the first study describing the cultivable TM and LAB from rainbow trout intestine and rearing environment along the fish life-cycle. The host-derived LAB active against fish pathogens comprise potential candidates as probiotics in rainbow trout farming as an alternative or complementary strategy to antibiotics and vaccines for disease prevention.
authors.affiliation: Grupo de Seguridad y Calidad de los Alimentos por Bacterias Lácticas, Bacteriocinas y Probióticos (Grupo SEGABALBP), Departamento de Nutrición, Bromatología y Tecnología de los Alimentos, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040-Madrid, Spain; Centre of Studies of Animal and Veterinary Sciences, University of Trás-os-Montes and Alto Douro, 5001-801-Vila Real, Portugal; Veterinary Science Department, University of Trás-os-Montes and Alto Douro, 5001-801-Vila Real, Portugal; Institute for Biotechnology and Bioengineering, Centre of Genomics and Biotechnology, University of Trás-os-Montes and Alto Douro, 5001-801-Vila Real, Portugal; Department of Genetics and Biotechnology, University of Trás-os-Montes and Alto Douro, 5001-801-Vila Real, Portugal.
authors.forename: Carlos
authors.initials: C
authors.lastname: Araújo
authors.affiliation: Grupo de Seguridad y Calidad de los Alimentos por Bacterias Lácticas, Bacteriocinas y Probióticos (Grupo SEGABALBP), Departamento de Nutrición, Bromatología y Tecnología de los Alimentos, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040-Madrid, Spain.
authors.forename: Estefanía
authors.initials: E
authors.lastname: Muñoz-Atienza
authors.affiliation: Grupo de Seguridad y Calidad de los Alimentos por Bacterias Lácticas, Bacteriocinas y Probióticos (Grupo SEGABALBP), Departamento de Nutrición, Bromatología y Tecnología de los Alimentos, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040-Madrid, Spain.
authors.forename: Yanina
authors.initials: Y
authors.lastname: Nahuelquín
authors.affiliation: Centre of Studies of Animal and Veterinary Sciences, University of Trás-os-Montes and Alto Douro, 5001-801-Vila Real, Portugal; Veterinary Science Department, University of Trás-os-Montes and Alto Douro, 5001-801-Vila Real, Portugal.
authors.forename: Patrícia
authors.initials: P
authors.lastname: Poeta
authors.affiliation: Institute for Biotechnology and Bioengineering, Centre of Genomics and Biotechnology, University of Trás-os-Montes and Alto Douro, 5001-801-Vila Real, Portugal; Department of Genetics and Biotechnology, University of Trás-os-Montes and Alto Douro, 5001-801-Vila Real, Portugal.
authors.forename: Gilberto
authors.initials: G
authors.lastname: Igrejas
authors.affiliation: Grupo de Seguridad y Calidad de los Alimentos por Bacterias Lácticas, Bacteriocinas y Probióticos (Grupo SEGABALBP), Departamento de Nutrición, Bromatología y Tecnología de los Alimentos, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040-Madrid, Spain.
authors.forename: Pablo E
authors.initials: PE
authors.lastname: Hernández
authors.affiliation: Grupo de Seguridad y Calidad de los Alimentos por Bacterias Lácticas, Bacteriocinas y Probióticos (Grupo SEGABALBP), Departamento de Nutrición, Bromatología y Tecnología de los Alimentos, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040-Madrid, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Herranz
authors.affiliation: Grupo de Seguridad y Calidad de los Alimentos por Bacterias Lácticas, Bacteriocinas y Probióticos (Grupo SEGABALBP), Departamento de Nutrición, Bromatología y Tecnología de los Alimentos, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040-Madrid, Spain. Electronic address: lcintas@vet.ucm.es.
authors.forename: Luis M
authors.initials: LM
authors.lastname: Cintas
mesh_terms: D000818:Animals; D000898:Antibiosis; D058893:DNA Barcoding, Taxonomic; D005399:Fishes / Q000382:microbiology*; D054884:Host-Pathogen Interactions; D056546:Lactobacillales / Q000145:classification / Q000235:genetics / Q000378:metabolism; D054892:Metagenome; D064307:Microbiota
keywords: Anti-fish pathogen activity; Aquaculture; Fish and aquatic microbiota; Fish probiotics; Lactic Acid Bacteria; Rainbow trout (Oncorhynchus mykiss, Walbaum)