As a model bacterial pathogen, Salmonella can gain access into non-phagocytic cells where it proliferates in a unique membrane-bounded compartment.It has long been thought that various nutritional and environmental differences within host cells will force bacterial pathogens to resculpt their proteome.Unfortunately, direct measurements of the in vivo bacterial proteome during infection has been technically challenging, though proteomic analyses of in vitro grown bacteria have been practiced for decades.