Deletion of the cheZ gene results in the loss of swimming ability and the decrease of adhesion ability to Caco-2 cells in Escherichia coli Nissle 1917.

The aim of this study was to elucidate the biological functions of the motility regulatory protein CheZ in the probiotic strain Escherichia coli Nissle 1917. A cheZ gene deletion strain Nissle 1917ΔcheZ was constructed using the CRISPR/Cas9 two-plasmid system, and the corresponding complemented strain Nissle 1917ΔcheZ/pBR322-cheZ was established. Combined studies of growth kinetics testing, motility assays, swarming motility assays, and bacterial adherence assays were performed to study the motility regulatory protein CheZ-mediated functions in the prototype Nissle 1917 strain, its isogenic cheZ mutant, and the corresponding complemented strain.