Abstract
Mutations in rcsC that result in constitutive colanic acid capsule synthesis were obtained in Salmonella enterica serovar Typhimurium. Most rcsC alleles were dominant; however, recessive rcsC alleles were also found, in agreement with the postulated double role (positive and negative) of RcsC on the activation of the RcsB/C phosphorelay system. Salmonella rcsC mutants with constitutive activation of the Rcs system are severely attenuated for virulence in BALB/c mice and their degree of attenuation correlates with the level of Rcs activation. Partial relief of attenuation by a gmm mutation indicates that capsule overproduction is one of the factors leading to avirulence in constitutively activated rcsC mutants.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Bacterial Capsules / metabolism
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Bacterial Proteins / genetics*
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Bacterial Proteins / metabolism
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Female
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Gene Expression Regulation, Bacterial*
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Mice
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Mice, Inbred BALB C
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Multienzyme Complexes / genetics*
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Multienzyme Complexes / metabolism
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Mutation*
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Phosphoprotein Phosphatases / genetics*
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Phosphoprotein Phosphatases / metabolism
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Polysaccharides / metabolism
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Protein Kinases / genetics*
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Protein Kinases / metabolism
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Salmonella Infections / microbiology
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Salmonella typhimurium / genetics
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Salmonella typhimurium / metabolism
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Salmonella typhimurium / pathogenicity*
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Transcription Factors / genetics
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Virulence
Substances
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Bacterial Proteins
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Multienzyme Complexes
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Polysaccharides
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Transcription Factors
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RcsB protein, Bacteria
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colanic acid
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Protein Kinases
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Phosphoprotein Phosphatases