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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2005-5-23
pubmed:abstractText
Several of the most virulent Salmonella enterica strains possess two genes encoding periplasmic Cu,Zn superoxide dismutase, sodC1 and sodC2, located on a lambdoid prophage and on the chromosome, respectively. These genes contribute to Salmonella virulence by protecting bacteria from superoxide generated by the host's phagocytes. To investigate the respective contributions of sodC1 and sodC2 to the virulence of a clinical isolate of Salmonella enterica serovar Choleraesuis (S. choleraesuis), we have analyzed both the intracellular survival of wild type and sodC mutant strains within J774 macrophages and Caco-2 cells, and their ability to proliferate in intraperitoneally-infected mice in competition assays. In agreement with previous studies, mutant strains lacking one or both sodC genes were equally impaired in their ability to survive within activated macrophages. However, when macrophage killing experiments were carried out with non-opsonized bacteria, sodC2 contributed to intracellular survival more than sodC1, indicating that changes in the pathways of bacterial uptake can modify the relative role of the two sodC genes. More unexpectedly, we have found that the ability of S. choleraesuis to survive within Caco-2 cells was severely affected by inactivation of sodC genes, sodC2 being more important than sodC1. As Caco-2 cells actively produce superoxide, this suggests that oxygen radical production by colonic cells has a role in controlling proliferation of facultative intracellular bacteria. Mouse infection studies confirmed that, in the S. choleraesuis strain under investigation, both sodC genes are required to confer full virulence, sodC2 contributing slightly more than sodC1 to Salmonella pathogenesis. Our findings contrast with the results of other studies carried out in S. enterica serovar Typhimurium and suggest that the relative contributions of sodC1 and sodC2 to host-pathogen interactive biology may vary depending on the Salmonella serovar or strain.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
1286-4579
pubmed:author
pubmed:issnType
Print
pubmed:volume
7
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
698-707
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Differential contribution of sodC1 and sodC2 to intracellular survival and pathogenicity of Salmonella enterica serovar Choleraesuis.
pubmed:affiliation
Dipartimento di Biologia, Università di Roma Tor Vergata, Via della Ricerca Scientifica, 00133 Rome, Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't