Autor/a:
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Ballesté Delpierre, Clara Celia; Fernandez Orth, Dietmar; Ferrer Navarro, Mario; Diaz Peña, Ramón; Odena Caballol, Antonia; Oliveira, Eliandre; Fàbrega, Anna; Vila Estapé, Jordi
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Abstract:
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Salmonella possesses virulence determinants that allow
replication under extreme conditions and invasion of host cells,
causing disease. Here, we examined four putative genes predicted
to encode membrane proteins (ydiY, ybdJ, STM1441 and ynaJ) and a
putative transcriptional factor (yedF). These genes were
identified in a previous study of a S. Typhimurium clinical
isolate and its multidrug-resistant counterpart. For STM1441 and
yedF a reduced ability to interact with HeLa cells was observed
in the knock-out mutants, but an increase in this ability was
absent when these genes were overexpressed, except for yedF
which phenotype was rescued when yedF was restored. In the
absence of yedF, decreased expression was seen for: i)
virulence-related genes involved in motility, chemotaxis,
attachment and survival inside the host cell; ii) global
regulators of the invasion process (hilA, hilC and hilD); and
iii) factors involved in LPS biosynthesis. In contrast, an
increased expression was observed for anaerobic metabolism
genes. We propose yedF is involved in the regulation of
Salmonella pathogenesis and contributes to the activation of the
virulence machinery. Moreover, we propose that, when oxygen is
available, yedF contributes sustained repression of the
anaerobic pathway. Therefore, we recommend this gene be named
vrf, for virulence-related factor. |