Once the Salmonella have been taken up by the cell,
they rely on other mechanisms for survival. In the cell,
Salmonella has evolved ways to circumvent targeting by
the phagosome-lysosome fusion pathway. Salmonella
Typhimurium has been shown to require an acidic pH
to induce replication and survival within the cells (Rathman
et al., 1996). It is believed to take up residence in
the membrane-bound vacuole of phagocytic and nonphagocytic
cells (Finlay and Falkow, 1997).