INVESTIGADORES
ESPARIZ Martin
artículos
Título:
Downregulation of RpoN-controlled genes protects Salmonella cells from killing by the cationic antimicrobial peptide polymyxin B
Autor/es:
JULIETA BARCHIESI; MARTÍN ESPARIZ; SUSANA K. CHECA; FERNANDO C. SONCINI
Revista:
FEMS MICROBIOLOGY LETTERS
Editorial:
John Wiley & Sons, Inc
Referencias:
Año: 2009 vol. 291 p. 73 - 79
ISSN:
0378-1097
Resumen:
Salmonella enterica polymyxin B (PM) resistance is modulated mainly by
substitutions of the acyl chains and the phosphate groups on the lipid A moiety
of lipopolysaccharide. These modifications are mediated by genes under the
control of the PmrA/PmrB and PhoP/PhoQ two-component regulatory systems.
In this study, a deletion in the gene encoding the alternative s54 factor, rpoN, was
shown to increase PM resistance without affecting protamine sensitivity. The
results presented here showed that the increased polymyxin resistance observed in
the rpoN mutant occurs through a PmrA/PhoP-independent pathway. Downregulation
of one or more genes belonging to the RpoN regulon may provide an
additional mechanism of defence against membrane-permeabilizing antimicrobial
peptides that helps the pathogen to survive in different environments.polymyxin B (PM) resistance is modulated mainly by
substitutions of the acyl chains and the phosphate groups on the lipid A moiety
of lipopolysaccharide. These modifications are mediated by genes under the
control of the PmrA/PmrB and PhoP/PhoQ two-component regulatory systems.
In this study, a deletion in the gene encoding the alternative s54 factor, rpoN, was
shown to increase PM resistance without affecting protamine sensitivity. The
results presented here showed that the increased polymyxin resistance observed in
the rpoN mutant occurs through a PmrA/PhoP-independent pathway. Downregulation
of one or more genes belonging to the RpoN regulon may provide an
additional mechanism of defence against membrane-permeabilizing antimicrobial
peptides that helps the pathogen to survive in different environments.s54 factor, rpoN, was
shown to increase PM resistance without affecting protamine sensitivity. The
results presented here showed that the increased polymyxin resistance observed in
the rpoN mutant occurs through a PmrA/PhoP-independent pathway. Downregulation
of one or more genes belonging to the RpoN regulon may provide an
additional mechanism of defence against membrane-permeabilizing antimicrobial
peptides that helps the pathogen to survive in different environments.rpoN mutant occurs through a PmrA/PhoP-independent pathway. Downregulation
of one or more genes belonging to the RpoN regulon may provide an
additional mechanism of defence against membrane-permeabilizing antimicrobial
peptides that helps the pathogen to survive in different environments.