Single cell analyses reveal distinct adaptation of typhoidal and non-typhoidal Salmonella enterica serovars to intracellular lifestyle

Salmonella enterica is a common foodborne, facultative intracellular enteropathogen. Human-restricted typhoidal S . serovars Typhi (STY) or Paratyphi A (SPA) cause severe typhoid paratyphoid fever, while many serovar Typhimurium (STM) strains have broad host range and in human hosts usually lead to self-limiting gastroenteritis. Due restriction of STY SPA primate hosts, experimental systems for studying the pathogenesis fever are limited. Therefore, STM infection susceptible mice commonly considered as model system these diseases. The type III secretion encoded by pathogenicity island 2 (SPI2-T3SS) key factor survival Inside cells, pathogen resides within -containing vacuole (SCV) induces tubular structures extending from SCV, termed -induced filaments (SIF). This study applies single cell analyses approaches, which flow cytometry harboring dual fluorescent protein reporters, effector translocation, correlative light electron microscopy investigate fate activities SPA. SPI2-T3SS functional translocation proteins, SCV SIF formation. However, only low proportion actively deploying exhibited rapid decline biosynthesis upon induction. role proliferation epithelial cells was observed, but not phagocytic cells. Our results indicate that reduced factors stealth strategy facilitate systemic spread persistence