A protein produced by Salmonella enterica-a leading cause of food-borne diseases, acts unexpectedly to counteract the bacteria's virulence. Protein secretion is crucial for the virulence of many pathogens, including Salmonella. A pathway- ZirTS was identified that consists of a secreted protein (ZirS) and its membrane translocator-ZirT. Inactivating ZirTS resulted in hypervirulent bacteria that could outcompete wild-type Salmonella in co-infection experiments. ZirTS functions as an antivirulence modulator remains to be established.