Abstract: The present invention provides methods for identification of antibiotic agents which cause the accumulation of ppGpp in bacterial organisms involving a relA-independent pathway. The methods comprise screening assays in which test compounds are brought into contact with relA.sup.- test cells and observing the effect such compounds have on ppGpp levels in the test cells. The invention also provides genetically manipulated relA.sup.- test cells which contain a reporter gene the expression of which is sensitive to the level of ppGpp. The invention also encompasses agents identified by the screening assays, and uses of these agents in the treatment of infectious diseases.