Miniaturized whole-cell bacterial bioreporter assay for identification of quorumsensing interfering compounds

The continuing emergence and spread of antibiotic-resistant bacteria is worrisome and new strategies to curb bacterial infections are being sought. The interference of bacterial quorum sensing (QS) signaling has been suggested as a prospective antivirulence strategy. The AI-2 QS system is present in multiple bacterial species and has been shown to be correlated with pathogenicity. To facilitate the discovery of novel compounds interfering with AI-2 QS, we established a high-throughput setup of whole-cell bioreporter assay, which can be performed in either 96- or 384-well format. Agonistic or antagonistic activities of the test compounds against Escherichia coli LsrB-type AI-2 QS system are monitored by measuring the level of β-galactosidase expression. A control strain expressing β-galactosidase in quorum sensing-independent manner is included into the assay for false-positive detection.