Killing niche competitors by remote-control bacteriophage induction
Fecha
2009Autor
Versión
Acceso abierto / Sarbide irekia
Tipo
Artículo / Artikulua
Versión
Versión publicada / Argitaratu den bertsioa
Impacto
|
10.1073/pnas.0809600106
Resumen
A surprising example of interspecies competition is the production
by certain bacteria of hydrogen peroxide at concentrations that are
lethal for others. A case in point is the displacement of Staphylococcus
aureus by Streptococcus pneumoniae in the nasopharynx,
which is of considerable clinical significance. How it is accomplished,
however, has been a great mystery, because H2O2 is a very
well k ...
[++]
A surprising example of interspecies competition is the production
by certain bacteria of hydrogen peroxide at concentrations that are
lethal for others. A case in point is the displacement of Staphylococcus
aureus by Streptococcus pneumoniae in the nasopharynx,
which is of considerable clinical significance. How it is accomplished,
however, has been a great mystery, because H2O2 is a very
well known disinfectant whose lethality is largely due to the
production of hyperoxides through the abiological Fenton reaction.
In this report, we have solved the mystery by showing that
H2O2 at the concentrations typically produced by pneumococci kills
lysogenic but not nonlysogenic staphylococci by inducing the SOS
response. The SOS response, a stress response to DNA damage, not
only invokes DNA repair mechanisms but also induces resident
prophages, and the resulting lysis is responsible for H2O2 lethality.
Because the vast majority of S. aureus strains are lysogenic, the
production of H2O2 is a very widely effective antistaphylococcal
strategy. Pneumococci, however, which are also commonly lysogenic
and undergo SOS induction in response to DNA-damaging
agents such as mitomycin C, are not SOS-induced on exposure to
H2O2. This is apparently because they are resistant to the DNAdamaging
effects of the Fenton reaction. The production of an
SOS-inducing signal to activate prophages in neighboring organisms
is thus a rather unique competitive strategy, which we
suggest may be in widespread use for bacterial interference.
However, this strategy has as a by-product the release of active
phage, which can potentially spread mobile genetic elements
carrying virulence genes. [--]
Materias
Hydrogen peroxide,
SOS response,
Staphylococcus aureus,
Streptococcus pneumoniae,
Bacterial interference
Editor
National Academy of Sciences
Publicado en
PNAS, January 27, 2009 106 (4) 1234-1238
Departamento
Universidad Pública de Navarra/Nafarroako Unibertsitate Publikoa. IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua
Versión del editor
Entidades Financiadoras
This work was supported by Comisión Interministerial de
Ciencia y Tecnología Grants BIO2005-08399-C02-02, BIO2008-05284-C02-02,
and BIO2008-00642-E/C; Cardenal Herrera-CEU University Grants PRCEUUCH25/
08 and Copernicus program; and by Conselleria de Agricultura, Pesca
i Alimentació (CAPiA), and from the Generalitat Valenciana (ACOMP07/258)
(J.R.P.). L.S. and D.V. were supported by Cardenal Herrera-CEU University
fellowships.