Implication of quorum sensing in Salmonella enterica serovar typhimurium virulence: the luxS gene is necessary for expression of genes in pathogenicity island 1.
Despite the fact that the regulatory system sensing density of cell population and its signaling molecule have been identified in Salmonella enterica, the biological significance of this phenomenon termed as quorum sensing remains unknown. In this report, we provide evidence that the luxS gene is necessary for Salmonella virulence phenotypes. Transcription assays showed that the cell-density-dependent induction of the invF gene was abolished in a Salmonella strain with the luxS gene deleted. The effect of the luxS deletion was also investigated in other InvF-regulated genes expressed from Salmonella pathogenicity island 1 (SPI-1). The decreased expression of SPI-1 genes in the strain with luxS deleted could be restored by either the addition of a synthetic signal molecule or the introduction of a plasmid copy of the luxS gene. Thus, the reduced expression of invF and its regulated genes in Salmonella cells lacking quorum sensing resulted in the attenuation of virulence phenotypes both in vitro and in vivo.
Choi
Jeongjoon
J
Department of Food and Animal Biotechnology, School of Agricultural Biotechnology, Seoul National University, Seoul 151-921, Republic of Korea.
Shin
Dongwoo
D
Ryu
Sangryeol
S
D000818:Animals; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D013437:Carbon-Sulfur Lyases / Q000235:genetics / Q000502:physiology*; D002460:Cell Line; D015169:Colony Count, Microbial; D004268:DNA-Binding Proteins / Q000096:biosynthesis; D004847:Epithelial Cells / Q000382:microbiology; D005260:Female; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D005816:Genetic Complementation Test; D044404:Genomic Islands; D006801:Humans; D008099:Liver / Q000382:microbiology; D051379:Mice; D008807:Mice, Inbred BALB C; D053038:Quorum Sensing / Q000235:genetics / Q000502:physiology*; D012481:Salmonella Infections, Animal; D012486:Salmonella typhimurium / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology*; D013154:Spleen / Q000382:microbiology; D014157:Transcription Factors / Q000096:biosynthesis; D014774:Virulence / Q000235:genetics / Q000502:physiology
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D014157:Transcription Factors; C090990:invF protein, Salmonella; D013437:Carbon-Sulfur Lyases; C117753:LuxS protein, Bacteria