CXCL2 and endometritis: Our finding that MG1655 titers in the FRT were statistically significantly lower than titers of the uropathogenic strains UTI89 and CFT073 echoes findings in pregnant mice that a pathogenic E. coli strain caused more robust ascending uterine infection than the lab strain MG1655 and caused significantly greater upregulation of the neutrophil chemoattractants Cxcl1 and Cxcl2 in uterine tissue, although in that study titers were not determined [17].