Virulence attenuation in Salmonella enterica rcsC mutants with constitutive activation of the Rcs system.
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.
García-Calderón
Clara B
CB
Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Apartado 1095, 41080 Sevilla, Spain.
García-Quintanilla
Meritxell
M
Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Apartado 1095, 41080 Sevilla, Spain.
Casadesús
Josep
J
Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Apartado 1095, 41080 Sevilla, Spain.
Ramos-Morales
Francisco
F
Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Apartado 1095, 41080 Sevilla, Spain.
D000818:Animals; D016667:Bacterial Capsules / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D005260:Female; D015964:Gene Expression Regulation, Bacterial; D051379:Mice; D008807:Mice, Inbred BALB C; D009097:Multienzyme Complexes / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D010749:Phosphoprotein Phosphatases / Q000235:genetics* / Q000378:metabolism; D011134:Polysaccharides / Q000378:metabolism; D011494:Protein Kinases / Q000235:genetics* / Q000378:metabolism; D012480:Salmonella Infections / Q000382:microbiology; D012486:Salmonella typhimurium / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity*; D014157:Transcription Factors / Q000235:genetics; D014774:Virulence
D001426:Bacterial Proteins; D009097:Multienzyme Complexes; D011134:Polysaccharides; D014157:Transcription Factors; C074889:RcsB protein, Bacteria; C004275:colanic acid; D011494:Protein Kinases; D010749:Phosphoprotein Phosphatases