Here, we describe the development and evaluation of a novel bioluminescent high-throughput Salmonella reverse mutation assay applicable to the screening of large numbers of small molecules. The bioluminescent Salmonella assay utilizes genetically engineered standard Salmonella tester strains TA98 and TA100 expressing the lux(CDABE) operon from Xenorhabdus luminescence. In principle, the assay employs bioluminescence as a sensor of changes in bacterial metabolism associated with starvation or energy depletion effectively identifying colonies of histidine-independent revertant cells in a high-throughput fashion. The assay provides highly concordant data with the outcome in the standard Salmonella plate incorporation reverse mutation assay. Since the results of the standard Salmonella plate assay are required by various regulatory agencies for approval of new drugs, the bioluminescent Salmonella assay can be effectively used for prioritization of compounds in pharmaceutical drug discovery as well as the evaluation of environmental and industrial chemicals. Because of its high throughput attributes, the assay permits effective, fast and economical screening of a large series of structural analogs enabling the investigation of structure-activity relationships.
