Erschienen:
American Society for Microbiology, 2003
Erschienen in:Infection and Immunity
Sprache:
Englisch
DOI:
10.1128/iai.71.8.4463-4471.2003
ISSN:
0019-9567;
1098-5522
Entstehung:
Anmerkungen:
Beschreibung:
<jats:title>ABSTRACT</jats:title>
<jats:p>
<jats:italic>Listeria monocytogenes</jats:italic>
is a gram-positive facultative intracellular food-borne pathogen that can cause severe infections in humans and animals. We have recently adapted signature-tagged transposon mutagenesis (STM) to identify genes involved in the virulence of
<jats:italic>L. monocytogenes</jats:italic>
. A new round of STM allowed us to identify a new locus encoding a protein homologous to AgrA, the well-studied response regulator of
<jats:italic>Staphylococcus aureus</jats:italic>
and part of a two-component system involved in bacterial virulence. The production of several secreted proteins was modified in the
<jats:italic>agrA</jats:italic>
mutant of
<jats:italic>L. monocytogenes</jats:italic>
grown in broth, indicating that the
<jats:italic>agr</jats:italic>
locus influenced protein secretion. Inactivation of
<jats:italic>agrA</jats:italic>
did not affect the ability of the pathogen to invade and multiply in cells in vitro. However, the virulence of the
<jats:italic>agrA</jats:italic>
mutant was attenuated in the mouse (a 10-fold increase in the 50% lethal dose by the intravenous route), demonstrating for the first time a role for the
<jats:italic>agr</jats:italic>
locus in the virulence of
<jats:italic>L. monocytogenes</jats:italic>
.
</jats:p>