Autoinducer-2 plays a crucial role in gut colonization and probiotic functionality of Bifidobacterium breve UCC2003.

In the present study we show that luxS of Bifidobacterium breve UCC2003 is involved in the production of the interspecies signaling molecule autoinducer-2 (AI-2), and that this gene is essential for gastrointestinal colonization of a murine host, while it is also involved in providing protection against Salmonella infection in Caenorhabditis elegans. We demonstrate that a B. breve luxS-insertion mutant is significantly more susceptible to iron chelators than the WT strain and that this sensitivity can be partially reverted in the presence of the AI-2 precursor DPD.

Bacteria that inhibit quorum sensing decrease biofilm formation and virulence in Pseudomonas aeruginosa PAO1.

In this study, we investigated the biotherapeutic potential of previously isolated quorum quenching (QQ) bacteria. Some of them produce and secrete small compounds that inhibit quorum sensing (QS), others quench QS by enzymatic degradation of N-acylhomoserine lactones (AHLs). The supernatant of cultures of these isolates was tested for inhibitory properties against P.

Isolation and identification of quorum quenching bacteria from environmental samples.

A large number of Gram-negative pathogens produce N-acylhomoserine lactones (AHLs) as signal molecules for quorum sensing (QS). This cell-cell communication system allows them to coordinate gene expression and regulate virulence. Therefore, strategies to inhibit QS are promising for the control of infectious diseases.