Phenotypic analysis of luxS gene deletion mutants and its application in virulence regulation research in group B Streptococcus.
- Author:
Qian OUYANG
1
;
Wen-li MA
;
Cui-hua LIU
;
Rong SHI
;
Wen-ling ZHENG
Author Information
- Publication Type:Journal Article
- MeSH: Bacterial Proteins; genetics; Carbon-Sulfur Lyases; genetics; Gene Deletion; Gene Expression Regulation, Bacterial; Lighting; Phenotype; Streptococcus agalactiae; genetics; pathogenicity; Virulence
- From: Journal of Southern Medical University 2006;26(1):117-121
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVETo explore the mechanism of virulence regulation in group B streptococcus (BGS) by studying LuxS-related AI-2 quorum-sensing pathway in GBS.
METHODSluxS gene deletion mutants of GBS (Delta lusX) were characterized by reverse transcription (RT)-PCR, colony immunoblot analysis, growth curve measurement, and cAMP determination. Functional analysis of luxS in the deletion mutants was conducted by bioluminescence assay.
RESULTSGenetic analysis results showed that the luxS deletion in the mutant 515-Delta lusX caused upregulation of scpB gene expression. Phenotypic analysis revealed that, in comparison with the wild strain, 515-Delta lusX mutant grew slowly in DCM media but quickly in THY media. An approximately two-fold decrement in bioluminescence was detected in the luxS deletion mutants as compared with the wild strain.
CONCLUSIONThis study confirms the importance of LuxS molecule in the AI-2 quorum-sensing pathway in GBS and provides new insights into the virulence regulation mechanism of GBS.
