Open AccessPlasmid‐mediated virulence genes in non‐typhoid Salmonella serovars
Author(s) -
Guiney Donald G.,
Fang Ferric C.,
Krause Martin,
Libby Stephen
Publication year - 1994
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1994.tb07253.x
Subject(s) - plasmid , operon , biology , rpos , virulence , locus (genetics) , gene , genetics , microbiology and biotechnology , sigma factor , promoter , gene expression , escherichia coli
Specific non‐typhoid Salmonella serovars carry large virulence plasmids that promote sustained extra‐intestinal infections. These plasmids all share a highly conserved 8‐kb region containing the spv operon, consisting of the regulatory spvR locus and the four structural spvABCD genes. The SpvR protein belongs to the LysR/MetR family of transcriptional activators, and induces spvABCD expression in the stationary phase in response to nutrient limitation. spv expression also depends on the chromosomal stationary phase sigma factor RpoS (KatF), and is markedly induced when salmonellae enter eukaryotic cells. Additional plasmid genes encode complement resistance including the rck locus which is homologous to ail from Yersinia . Rck blocks formation of the complement membrane attack complex on the bacterial surface. Several loci involved in plasmid replication and stable maintenance have also been identified.