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Inducible prophages contribute to Salmonella virulence in mice
Author(s) -
FigueroaBossi Nara,
Bossi Lionello
Publication year - 1999
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1046/j.1365-2958.1999.01461.x
Subject(s) - prophage , virulence , biology , salmonella , microbiology and biotechnology , gene , periplasmic space , genome , pathogenicity island , bacteria , pathogen , genetics , escherichia coli , bacteriophage
We show that Salmonella typhimurium harbours two fully functional prophages, Gifsy ‐1 and Gifsy ‐2, that can be induced by standard treatments or, more effectively, by exposing bacteria to hydrogen peroxide. Curing bacteria for the Gifsy ‐2 prophage significantly reduces Salmonella 's ability to establish a systemic infection in mice. Cured strains recover their virulence properties upon relysogenization. Phage Gifsy ‐2 carries the sodC gene for a periplasmic [Cu,Zn]‐superoxide dismutase previously implicated in the bacterial defences against killing by macrophages. The contribution of the Gifsy ‐1 prophage to virulence — undetectable in the presence of Gifsy ‐2 as prophage — becomes significant in cells that lack Gifsy ‐2 but carry the sodC gene integrated in the chromosome. This confirms the involvement of Gifsy ‐2‐encoded SodC protein in Salmonella pathogenicity and suggests that the Gifsy ‐1 prophage carries one or more additional virulence genes that have a functional equivalent on the Gifsy ‐2 genome.