Genetically modified tumor-targeted bacteria with reduce virulence

A method of inhibiting growth or reducing volume of a solid tumor cancer, comprising administering an effective amount of a mutant Salmonella sp. to a patient having a solid tumor cancer, wherein said mutant Salmonella sp. comprises a genetically modified msbb gene in a tumor targeting mutant Salmonella which is capable of inhibiting growth of the solid tumor when administered in vivo, and wherein said mutant Salmonella sp. expresses an altered lipid A molecule compared to wild-type Salmonella sp., induces TNFα expression at a level less than that induced by a wild-type Salmonella sp., and is capable of being grown to saturation in LB media at 37° C.