<i>Citrobacter rodentium</i> possesses a functional type II secretion system necessary for successful host infection.

"raw 16s sequence data from mouse fecal samples have been deposited in the ncbi sra database with the accession number (prjna949387)."

"Disclosure statement No potential conflict of interest was reported by the author(s)."

"Author contributions: Z.K., S.E.W., and B.B.F. conceived the project. Z.K., S.E.W., and B.B.F. wrote the original draft of the manuscript with input and edits from all authors. Z.K. and S.E.W. designed and performed experiments and analyzed data. S.E.W. and A.S.P. performed animal work. S.E.W., A.S.P., and J.P.D. processed samples obtained from in vivo studies. Z.K. constructed the bacterial deletion mutants. A.S.P. constructed the chromosomal complementation strains. Z.K. performed the homology analysis and visualization. K.M.M. assisted with in vitro studies. All authors contributed to a draft of the manuscript. B.B.F. and L.J.F. contributed to supervision and provided funding."