Salmonella, a member of enteric bacilli, is one of the most severe etiological agents of food-borne diseases. It is widely accepted that recombinant live vaccines using attenuated Salmonella as a vector to deliver passenger antigen induce immune responses not only against salmonella infection, but also against passenger pathogenic infection [8] . Live-attenuated Salmonella has been shown to deliver DNA vaccines [9, 35, 41, 47] . Early in the 1970s, Fang et al. screened out an attenuated Salmonella choleraesuis C500, which was a licensed live vaccine against swine paratyphoid [13] . Liu et al. proved that the attenuated S. choleraesuis C500 carrying an oral DNA vaccine induced an immune response against FMDV [29] .