The Periplasmic Trehalase Affects Type 1 Fimbria Production and Virulence of Extraintestinal Pathogenic Escherichia coli Strain MT78.

Extraintestinal pathogenic (ExPEC) is responsible for various infections outside the gastrointestinal tract in humans and other animals. ExPEC strain MT78 is invasive to various nonphagocytic cells and highly virulent To identify genes required for invasion of nonphagocytic cells by this strain, we applied signature-tagged mutagenesis to generate a library of mutants and tested them for invasion of avian fibroblasts. Mutants showing reduced cellular invasion included those with insertions in the operon, encoding type 1 fimbriae.