Low-dose inoculation of Escherichia coli achieves robust vaginal colonization and results in ascending infection accompanied by severe uterine inflammation in mice
Fig 2
After exogenous estrogen treatment, some C57BL/6J mice stay in the estrus phase for several weeks.
C57BL/6 mice from Jackson or Envigo were given two doses of β-estradiol 17-valerate 72 hours apart and followed for one month. (A) Vaginal (PBS) washes were collected at the indicated 15 time points over 31 days and the stage of the estrous cycle was determined by wet mount microscopy according to the criteria in [27]. Data are from one experiment with n = 5 mice per group. (B) Shown are wet mount images at 20x magnification, taken at the indicated days post-estrogenization, from one representative Jackson mouse that did not come out of estrus during the experiment (top row) and one representative Envigo mouse that came out of estrus on day 13 (bottom row). Estrus is defined as an abundance of cornified epithelial cells in washes (examples marked with * in the first column); as mice leave estrus these are replaced by more rounded epithelial cells (examples marked with # in the third column) and leukocytes (examples marked with arrows in the third column). These experiments were conducted with static (non-ventilated) micro-isolator cages.