biostudies-literatureUnknown107(41)Knodler LAIntramural NIH HHSCanadian Institutes of Health ResearchSalmonella enterica is an intracellular bacterial pathogen that resides and proliferates within a membrane-bound vacuole in epithelial cells of the gut and gallbladder. Although essential to disease, how Salmonella escapes from its intracellular niche and spreads to secondary cells within the same host, or to a new host, is not known. Here, we demonstrate that a subpopulation of Salmonella hyperreplicating in the cytosol of epithelial cells serves as a reservoir for dissemination. These bacteria are transcriptionally distinct from intravacuolar Salmonella. They are induced for the invasion-associated type III secretion system and possess flagella; hence, they are primed for invasion. Epithelial cells laden with these cytosolic bacteria are extruded out of the monolayer, releasing invasion-Proceedings of the National Academy of Sciences of the United States of America17733-8https://www.ebi.ac.uk/biostudies/studies/S-EPMC2955089biostudies-literatureDissemination of invasive Salmonella via bacterial-induced extrusion of mucosal epithelia.PMC2955089Steele-Mortimer OHansen BWinfree SKnodler LAMontero MVallance BACelli JfalseDissemination of invasive Salmonella via bacterial-induced extrusion of mucosal epithelia.Salmonella enterica is an intracellular bacterial pathogen that resides and proliferates within a membrane-bound vacuole in epithelial cells of the gut and gallbladder. Although essential to disease, how Salmonella escapes from its intracellular niche and spreads to secondary cells within the same host, or to a new host, is not known. Here, we demonstrate that a subpopulation of Salmonella hyperreplicating in the cytosol of epithelial cells serves as a reservoir for dissemination. These bacteria are transcriptionally distinct from intravacuolar Salmonella. They are induced for the invasion-associated type III secretion system and possess flagella; hence, they are primed for invasion. Epithelial cells laden with these cytosolic bacteria are extruded out of the monolayer, releasing invasion-2010-01-01T00:00:00Z2010 Oct2025-04-19T04:11:25.224Z2019-03-27T00:34:52ZS-EPMC29550892087611910.1073/pnas.1006098107