INSIBIO 05451
INSTITUTO SUPERIOR DE INVESTIGACIONES BIOLOGICAS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Polyphosphate degradation in stationary phase triggers biofilm formation via LuxS quorum sensing system in Escherichia coli
Autor/es:
GRILLO PUERTAS, MARIANA; SOTO, SARA M; VILLEGAS, JOSEFINA MARÍA; RINTOUL, MARIA REGINA; RAPISARDA, VIVIANA ANDREA
Lugar:
Miami
Reunión:
Conferencia; 6th ASM Conference in Biofilms; 2012
Resumen:
Biofilm
is the prevailing microbial life-style
of
bacteria in most natural environments.
Polyphosphate
(polyP), an ubiquitous linear
polymer
of hundreds of orthophosphate residues,
has
a crucial role in stress responses,
stationary-phase
survival, and it was associated
to
bacterial biofilm formation and production
of
virulence factors. In previous work, we
have
shown that Escherichia coli cells grown
in
media containing a critical phosphate concentration
>37
mM maintained an unusual
high
polyP level in stationary phase. Here, we
studied
how polyP levels in stationary phase
affect
biofilm formation capacity in E. coli
laboratory
strains and urpathogenic isolates. In
laboratory
strains, polymer levels were modulated
by
the media phosphate concentration
or
using mutant strains in polyP metabolism.
Cells
grown in media containing phosphate
concentrations
higher than 35 mM were defective
in
biofilm formation. Besides there was a
disassembly
of 24 h preformed biofilm by the
addition
of high phosphate concentration to the
medium.
These phenotypes were related to the
maintenance
or re-synthesis of polyP in stationary
phase
in static conditions. No biofilm
formation
was observed in both ppk-ppx- and
ppk-ppx-/ppk+
strains, deficient in polyP
synthesis
and hydrolysis, respectively. luxS
and
lsrK mutants, impaired in autoinducer-2
quorum
sensing signal metabolism, were unable
to
form biofilm unless stationary phase MT wild type conditioned media were used.
Taken
together, polyP degradation is required
for
biofilm formation in sufficient phosphate
media,
activating or triggering the production
of
autoinducer-2. Preliminary assays related to
phosphate-dependent
biofilm formation capacity
by
urophatogenic E. coli isolates from prostatitis
showed
different phenotypes in biofilm
formation
in response to phosphate. According
to
our results, phosphate concentration of the
culture
media should be carefully considered
in bacterial adhesion and virulence studies.
