Time-lapse Movies for Geiser et al 2021, mBio, "Salmonella enterica Serovar Typhimurium Exploits Cycling through Epithelial Cells to Colonize Human and Murine Enteroids"

<div><b>Time-lapse movies for Geiser et al 2021, mBio</b></div><div><br></div><div><div>"<i>Salmonella enterica</i> Serovar Typhimurium Exploits Cycling through Epithelial Cells to Colonize Human and Murine Enteroids"<br></div><div><br></div><div>Abstract:<br></div><div>Enterobacterial pathogens infect the gut by a multistep process, resulting in colonization of both the lumen and the mucosal epithelium. Due to experimental constraints, it remains challenging to address how luminal and epithelium-lodged pathogen populations cross-feed each other in vivo. Enteroids are cultured three-dimensional miniature intestinal organs with a single layer of primary intestinal epithelial cells (IECs) surrounding a central lumen. They offer new opportunities to study enterobacterial infection under near-physiological conditions, at a temporal and spatial resolution not attainable in animal models, but remain poorly explored<br>in this context. We employed microinjection, time-lapse microscopy, bacterial genetics, and barcoded consortium infections to describe the complete infection cycle of<br><i>Salmonella enterica</i> serovar Typhimurium in both human and murine enteroids. Flagellar motility and type III secretion system 1 (TTSS-1) promoted <i>Salmonella</i> Typhimurium targeting of the intraepithelial compartment and breaching of the epithelial barrier. Strikingly, however, TTSS-1 also potently boosted colonization of the enteroid lumen. By<br>tracing the infection over time, we identified a cycle(s) of TTSS-1-driven IEC invasion, intraepithelial replication, and reemergence through infected IEC expulsion as a key<br>mechanism for <i>Salmonella </i>Typhimurium luminal colonization. These findings suggest a positive feed-forward loop, through which IEC invasion by planktonic bacteria fuels further luminal population expansion, thereby ensuring efficient colonization of both the intraepithelial and luminal niches.<br></div><div><br></div></div><div><div>Please see Readme.docx for detailed information about each movie. </div></div>