title: Mortality and translocation assay to study the protective capacity of Bifidobacterium lactis INL1 against Salmonella Typhimurium infection in mice.
abstract: The mouse has been largely used for the study of the protective capacity of probiotics against intestinal infections caused by Salmonella. In this work we aimed at comparing the mortality and translocation assay for the study of the protective capacity of the human breast milk-derived strain Bifidobacterium animalis subsp. lactis INL1 on a model of gut infection by Salmonella enterica subsp. enterica serovar Typhimurium. Different doses of S. Typhimurium FUNED and B. animalis subsp. lactis INL 1 were administered to Balb/c mice in a mortality or a translocation assay. The survival of the control group in the mortality assay resulted to be variable along experiments, and then we preferred to use a translocation assay where the preventive administration of 109 cfu of bifidobacteria/mouse for 10 consecutive days significantly reduced the number of infected animals and the levels of translocation to liver and spleen, with enhanced secretory immunoglobulin A and interleukin 10 production in the small and large intestine, respectively. Ten days of B. animalis subsp. lactis strain INL1 administration to mice significantly reduced both the incidence and the severity of Salmonella infection in a mouse model of translocation. This work provided the first evidence that a translocation assay, compared to a mortality assay, could be more useful to study the protective capacity of probiotics against Salmonella infection, as more information can be obtained from mice and less suffering is conferred to animals due to the fact that the mortality assay is shorter than the latter. These facts are in line with the guidelines of animal research recently established by the National Centre for the Replacement, Refinement & Reduction of Animals in Research.
authors.affiliation: Instituto de Lactología Industrial (INLAIN, UNL-CONICET), Facultad de Ingeniería Química, Universidad Nacional del Litoral, Santiago del Estero 2829, Santa Fe (3000), Argentina.
authors.forename: M F
authors.initials: MF
authors.lastname: Zacarías
authors.affiliation: Instituto de Lactología Industrial (INLAIN, UNL-CONICET), Facultad de Ingeniería Química, Universidad Nacional del Litoral, Santiago del Estero 2829, Santa Fe (3000), Argentina.
authors.forename: J
authors.initials: J
authors.lastname: Reinheimer
authors.affiliation: Departamento de Matemática, Facultad de Ingeniería Química, Universidad Nacional del Litoral and Instituto de Matemática Aplicada del Litoral (CONICET-UNL), Santa Fe (3000), Argentina.
authors.forename: L
authors.initials: L
authors.lastname: Forzani
authors.affiliation: Lactic Acid Bacteria and Mucosal Immunity, Center for Infection and Immunity of Lille, Pasteur Institute of Lille, INSERM U1019 - CNRS UMR 8204, Lille, France.
authors.forename: C
authors.initials: C
authors.lastname: Grangette
authors.affiliation: Instituto de Lactología Industrial (INLAIN, UNL-CONICET), Facultad de Ingeniería Química, Universidad Nacional del Litoral, Santiago del Estero 2829, Santa Fe (3000), Argentina.
authors.forename: G
authors.initials: G
authors.lastname: Vinderola
mesh_terms: D000818:Animals; D000898:Antibiosis; D058491:Bacterial Load; D018988:Bacterial Translocation; D001644:Bifidobacterium / Q000254:growth & development* / Q000302:isolation & purification; D004195:Disease Models, Animal; D006801:Humans; D008099:Liver / Q000382:microbiology; D008297:Male; D008807:Mice, Inbred BALB C; D008895:Milk, Human / Q000382:microbiology; D019936:Probiotics / Q000494:pharmacology*; D012481:Salmonella Infections, Animal / Q000382:microbiology / Q000473:pathology* / Q000517:prevention & control*; D012486:Salmonella typhimurium / Q000254:growth & development*; D013154:Spleen / Q000382:microbiology; D016019:Survival Analysis
keywords: Salmonella; bifidobacteria; infection; mouse model; probiotic