title: Deletion of a prophage-like element causes attenuation of Salmonella enterica serovar Enteritidis and promotes protective immunity.
abstract: Salmonella enterica serovar Enteritidis (S. Enteritidis) is a wide host range serovar belonging to the S. enterica genus. Worldwide, it is one of the most frequent causes of food borne disease. Similar to S. Typhimurium, some virulence genes of S. Enteritidis are located in pathogenicity islands and prophages. In this study we have generated a mutant strain of S. Enteritidis lacking a prophage-like element, denominated varphiSE12. The resulting mutant strain was attenuated and promoted protective immunity in infected mice. Although S. Enteritidis strains lacking the complete prophage varphiSE12 remained capable of surviving inside phagocytic cells, they showed a significantly reduced capacity to colonize internal organs and failed to cause lethal disease in mice. Consistent with these data, infection with S. Enteritidis strains lacking prophage varphiSE12 promoted the production of anti-Salmonella IgG antibodies and led to protection against a challenge with virulent strains of S. Enteritidis. These results suggest that strains lacking this prophage can induce a protective immunity in mice and be considered as potential attenuated vaccines against S. Enteritidis.
authors.affiliation: Millennium Nucleus on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Alameda 340, Santiago 8331010, Chile.
authors.forename: Daniela V
authors.initials: DV
authors.lastname: Araya
authors.forename: Tania S
authors.initials: TS
authors.lastname: Quiroz
authors.forename: Hugo E
authors.initials: HE
authors.lastname: Tobar
authors.forename: Rodrigo J
authors.initials: RJ
authors.lastname: Lizana
authors.forename: Carolina P
authors.initials: CP
authors.lastname: Quezada
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Santiviago
authors.forename: Claudia A
authors.initials: CA
authors.lastname: Riedel
authors.forename: Alexis M
authors.initials: AM
authors.lastname: Kalergis
authors.forename: Susan M
authors.initials: SM
authors.lastname: Bueno
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology; D001483:Base Sequence; D007074:Immunoglobulin G / Q000276:immunology; D051379:Mice; D010586:Phagocytes / Q000276:immunology / Q000382:microbiology; D039002:Prophages / Q000235:genetics / Q000276:immunology*; D012480:Salmonella Infections / Q000235:genetics / Q000276:immunology* / Q000517:prevention & control; D022562:Salmonella Vaccines / Q000235:genetics / Q000276:immunology*; D012477:Salmonella enteritidis / Q000235:genetics / Q000276:immunology* / Q000472:pathogenicity; D017384:Sequence Deletion / Q000235:genetics / Q000276:immunology*; D014613:Vaccines, Attenuated / Q000235:genetics / Q000276:immunology; D037521:Virulence Factors / Q000235:genetics / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D007074:Immunoglobulin G; D022562:Salmonella Vaccines; D014613:Vaccines, Attenuated; D037521:Virulence Factors