[Detection of quorum-sensing pathway and construction of LuxS gene deletion mutants of group B Streptococcus].
OBJECTIVE
To detect the possible presence of AI-2 quorum-sensing pathway and construct group B Streptococcus (GBS) mutants with deletion of LuxS gene related to quorum-sensing pathway.


METHODS
V. harveyi BB170 was employed as the reporter strain to detect AI-2 pathway in GBS, and identification of LuxS homologous gene in GBS type V strain 2603 was performed by software-based analysis. LuxS gene deletion mutant Delta LusX was then constructed in GBS by means of allelic exchange and verified by Southern hybridization analysis.


RESULTS
A component in the secretions of GBS could induce bioluminescence activity in the reporter strain, suggesting the presence of AI-2 quorum-sensing pathway in GBS. luxS homologous gene was detected in GBS and LuxS gene deletion mutants was successfully constructed in GBS Ia 515 and V 2603 strains.


CONCLUSIONS
This study establishes a bacterial model for studying the role of LuxS molecule in AI-2 quorum-sensing pathway in GBS and provides new insights into virulence regulation mechanism of GBS.
Ou
Yang-qian
YQ
Institute of Genetic Engineering, Southern Medical University, Guangzhou 510515, China. oyq@fimmu.com
Ma
Wen-li
WL
Liu
Cui-hua
CH
Shi
Rong
R
Zheng
Wen-ling
WL
D001422:Bacterial Adhesion / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics*; D013437:Carbon-Sulfur Lyases / Q000235:genetics*; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology*; D015398:Signal Transduction / Q000187:drug effects; D013292:Streptococcus agalactiae / Q000235:genetics* / Q000302:isolation & purification
D001426:Bacterial Proteins; D013437:Carbon-Sulfur Lyases; C117753:LuxS protein, Bacteria