RED DE EXCELENCIA PARA LA EXPLOTACION DE BACTERIAS CON FINES TERAPEUTICOS
SAF2014-56716-REDT
•
Nombre agencia financiadora Ministerio de Economía y Competitividad
Acrónimo agencia financiadora MINECO
Programa Programa Estatal de Fomento de la Investigación Científica y Técnica de Excelencia
Subprograma Subprograma Estatal de Generación del Conocimiento
Convocatoria Acciones de dinamización "Redes de Excelencia" (2014)
Año convocatoria 2014
Unidad de gestión Dirección General de Investigación Científica y Técnica
Centro beneficiario AGENCIA ESTATAL CONSEJO SUPERIOR DE INVESTIGACIONES CIENTIFICAS (CSIC)
Centro realización CENTRO NACIONAL DE BIOTECNOLOGÍA (CNB) - DEPARTAMENTO DE BIOLOGÍA MOLECULAR Y CELULAR
Identificador persistente http://dx.doi.org/10.13039/501100003329
Publicaciones
Found(s) 2 result(s)
Found(s) 1 page(s)
Found(s) 1 page(s)
Lack of the PGA exopolysaccharide in Salmonella as an adaptive trait for survival in the host
Academica-e. Repositorio Institucional de la Universidad Pública de Navarra
- Echeverz Sarasúa, Maite
- García Martínez, Begoña
- Sabalza Baztán, Amaia
- Valle Turrillas, Jaione
- Gabaldón Estevan, Juan Antonio
- Solano Goñi, Cristina
- Lasa Uzcudun, Íñigo
Many bacteria build biofilm matrices using a conserved exopolysaccharide named PGA or
PNAG (poly-β-1,6-N-acetyl-D-glucosamine). Interestingly, while E. coli and other members
of the family Enterobacteriaceae encode the pgaABCD operon responsible for PGA synthesis,
Salmonella lacks it. The evolutionary force driving this difference remains to be determined.
Here, we report that Salmonella lost the pgaABCD operon after the divergence
of Salmonella and Citrobacter clades, and previous to the diversification of the currently
sequenced Salmonella strains. Reconstitution of the PGA machinery endows Salmonella
with the capacity to produce PGA in a cyclic dimeric GMP (c-di-GMP) dependent manner.
Outside the host, the PGA polysaccharide does not seem to provide any significant benefit
to Salmonella: resistance against chlorine treatment, ultraviolet light irradiation, heavy metal
stress and phage infection remained the same as in a strain producing cellulose, the main
biofilm exopolysaccharide naturally produced by Salmonella. In contrast, PGA production
proved to be deleterious to Salmonella survival inside the host, since it increased susceptibility
to bile salts and oxidative stress, and hindered the capacity of S. Enteritidis to survive
inside macrophages and to colonize extraintestinal organs, including the gallbladder. Altogether,
our observations indicate that PGA is an antivirulence factor whose loss may have
been a necessary event during Salmonella speciation to permit survival inside the host., This work was supported by the Spanish Ministry of Economy and Competitiveness grants BIO2014-53530-R and SAF2014-56716-REDT. JV was supported by Ramon y Cajal (RYC-2009-03948) contract from the Spanish Ministry of Economy and Competitiveness.
PNAG (poly-β-1,6-N-acetyl-D-glucosamine). Interestingly, while E. coli and other members
of the family Enterobacteriaceae encode the pgaABCD operon responsible for PGA synthesis,
Salmonella lacks it. The evolutionary force driving this difference remains to be determined.
Here, we report that Salmonella lost the pgaABCD operon after the divergence
of Salmonella and Citrobacter clades, and previous to the diversification of the currently
sequenced Salmonella strains. Reconstitution of the PGA machinery endows Salmonella
with the capacity to produce PGA in a cyclic dimeric GMP (c-di-GMP) dependent manner.
Outside the host, the PGA polysaccharide does not seem to provide any significant benefit
to Salmonella: resistance against chlorine treatment, ultraviolet light irradiation, heavy metal
stress and phage infection remained the same as in a strain producing cellulose, the main
biofilm exopolysaccharide naturally produced by Salmonella. In contrast, PGA production
proved to be deleterious to Salmonella survival inside the host, since it increased susceptibility
to bile salts and oxidative stress, and hindered the capacity of S. Enteritidis to survive
inside macrophages and to colonize extraintestinal organs, including the gallbladder. Altogether,
our observations indicate that PGA is an antivirulence factor whose loss may have
been a necessary event during Salmonella speciation to permit survival inside the host., This work was supported by the Spanish Ministry of Economy and Competitiveness grants BIO2014-53530-R and SAF2014-56716-REDT. JV was supported by Ramon y Cajal (RYC-2009-03948) contract from the Spanish Ministry of Economy and Competitiveness.
Sensory deprivation in Staphylococcus aureus
Academica-e. Repositorio Institucional de la Universidad Pública de Navarra
- Villanueva San Martín, Maite
- García Martínez, Begoña
- Valle Turrillas, Jaione
- Rapún Araiz, Beatriz
- Ruiz de los Mozos Aliaga, Igor
- Solano Goñi, Cristina
- Martí, Miguel
- Penadés, José R.
- Toledo Arana, Alejandro
- Lasa Uzcudun, Íñigo
Bacteria use two-component systems (TCSs) to sense and respond to environmental
changes. The core genome of the major human pathogen Staphylococcus aureus encodes 16
TCSs, one of which (WalRK) is essential. Here we show that S. aureus can be deprived of its
complete sensorial TCS network and still survive under growth arrest conditions similarly to
wild-type bacteria. Under replicating conditions, however, the WalRK system is necessary
and sufficient to maintain bacterial growth, indicating that sensing through TCSs is mostly
dispensable for living under constant environmental conditions. Characterization of S. aureus
derivatives containing individual TCSs reveals that each TCS appears to be autonomous and
self-sufficient to sense and respond to specific environmental cues, although some level of
cross-regulation between non-cognate sensor-response regulator pairs occurs in vivo. This
organization, if confirmed in other bacterial species, may provide a general evolutionarily
mechanism for flexible bacterial adaptation to life in new niches., This work was supported by the Spanish Ministry of Economy and Competitiveness grants BIO2011-30503-C02-02, BIO2014-53530-R, SAF2014-56716-REDT, and RTC-2015-3184-1. J.V. was supported by Ramon y Cajal (RYC-2009-03948) contract from the Spanish Ministry of Economy and Competitiveness.
changes. The core genome of the major human pathogen Staphylococcus aureus encodes 16
TCSs, one of which (WalRK) is essential. Here we show that S. aureus can be deprived of its
complete sensorial TCS network and still survive under growth arrest conditions similarly to
wild-type bacteria. Under replicating conditions, however, the WalRK system is necessary
and sufficient to maintain bacterial growth, indicating that sensing through TCSs is mostly
dispensable for living under constant environmental conditions. Characterization of S. aureus
derivatives containing individual TCSs reveals that each TCS appears to be autonomous and
self-sufficient to sense and respond to specific environmental cues, although some level of
cross-regulation between non-cognate sensor-response regulator pairs occurs in vivo. This
organization, if confirmed in other bacterial species, may provide a general evolutionarily
mechanism for flexible bacterial adaptation to life in new niches., This work was supported by the Spanish Ministry of Economy and Competitiveness grants BIO2011-30503-C02-02, BIO2014-53530-R, SAF2014-56716-REDT, and RTC-2015-3184-1. J.V. was supported by Ramon y Cajal (RYC-2009-03948) contract from the Spanish Ministry of Economy and Competitiveness.