Link to Pubmed [PMID] – 30345327
Bio Protoc 2018 Sep;8(18)
is a Gram-negative bacterium causing a gastro-enteric disease called salmonellosis. During the first phase of infection, uses its flagella to swim near the surface of the epithelial cells and to target specific site of infection. In order to study the selection criteria that determine which host cells are targeted by the pathogen, and to analyze the relation between infecting (, cooperation or competition), we have established a high-throughput microscopic assay of HeLa cells sequentially infected with fluorescent bacteria. Using an automated pipeline of image analysis, we quantitatively characterized a multitude of parameters of infected and non-infected cells. Based on this, we established a predictive model that allowed us to identify those parameters involved in host cell vulnerability towards infection. We revealed that host cell vulnerability has two origins: a pathogen-induced cellular vulnerability emerging from uptake and persisting at later stages of the infection process; and a host cell-inherent vulnerability linked with cell inherent attributes, such as local cell crowding, and cholesterol content. Our method forecasts the probability of infection within monolayers of epithelial cells based on morphological or molecular host cell parameters. Here, we provide a detailed description of the workflow including the computer-based analysis pipeline. Our method has the potential to be applied to study other combinations of host-pathogen interactions.