The interplay between Salmonella Typhimurium and the intestinal mucosa during oral infection
Intestinal pathogens are an important tool to study the mucosal immune system and to understand how pathogens are differentiated from members of the commensal microbiota. The dynamic interaction between the pathogen Salmonella Typhimurium and its host is discussed in detail in a review in "Microbiology Spectrum" by Annika Hausmann and Wolf-Dietrich Hardt.
The intestine is a particularly interesting site to study host-pathogen interactions, as it is densely colonized by the commensal microbiota, but also an entry site for pathogens. This poses special challenges on the local immune system, which constantly screens the environment to respond to potential pathogens while maintaining homeostasis of the tissue. Physical barriers, chemical defenses and innate immune responses contribute to homeostasis by segregating the microbiota from the sterile lamina propria. The intestinal pathogen Salmonella Typhimurium is a potent tool to probe these barriers and to understand how bacteria can circumvent them. Strikingly, the interaction between bacterial virulence factor expression, phenotypic diversification of the pathogen and the diversity of host responses triggered by these different pathogen phenotypes is a dynamic process, which is tightly regulated throughout the course of infection. Successful infection of the gut tissue thus relies on a delicate balance of responses of the pathogen and its host.
Link to the paper in external page Microbiology Spectrum.