Open AccessAn iron‐dependent mutant of Listeria monocytogenes of attenuated virulence
Author(s) -
Rouquette Corinne,
Bolla Jeanmichel,
Berche Patrick
Publication year - 1995
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.1574-6968.1995.tb07864.x
Subject(s) - virulence , listeria monocytogenes , insertional mutagenesis , mutant , biology , transposable element , operon , gene , listeria , microbiology and biotechnology , genetics , bacteria
A bank of Tn 917 ‐insertional mutants from the facultative intracellular pathogen Listeria monocytogenes was screened by an original method based on bacterial growth on synthetic medium under iron‐limiting conditions. One mutant, whose in vitro growth in synthetic medium was specifically dependent upon the availability of iron in its environment, was isolated and characterized. The insertional event occurred in a non‐coding region, upstream of a rrn operon and located within a 1100‐kb Not I fragment of the physical map, where the virulence genes already identified in L. monocytogenes were also present. Protein analysis by SDS‐PAGE revealed a pleiotropic effect of the insertional event on cell‐associated proteins, suggesting a polar effect of the transposon on adjacent unknown gene(s). The virulence in the mouse of this mutant was strongly impaired, although it was capable in vitro of growing intracellularly and of spreading from cell to cell, as shown by the production of lytic plaques on cell culture.