In vitro and in vivo stability of recombinant plasmids in a vaccine strain of Salmonella enterica var. Typhimurium

Abstract

This study examined the ability of different plasmid vectors encoding HC fragment, the non-toxic binding portion of tetanus toxin, to be stably retained by Salmonella enterica var. Typhimurium (Salmonella typhimurium) vaccine strain BRD509 and, upon immunisation, to induce an antibody response against the carried antigen. The HC fragment expression cassette containing the transcription/translation signals, HC fragment open reading frame and the downstream TrpA terminator, was excised from pTETtac4 and incorporated into the plasmids pIC20H, pBR322, pACYC184 and pRSF1010. The resulting constructs were transferred into attenuated S. typhimurium, BRD509, and the level of HC fragment expression w..