Low-dose inoculation of Escherichia coli achieves robust vaginal colonization and results in ascending infection accompanied by severe uterine inflammation in mice

• DOI: 10.1371/journal.pone.0219941
• Publication Date: 2019-07-22T17:33:58Z
• Authors: Valerie P. O’Brien; Nicole M. Gilbert; Tania Lebratti; Kavita Agarwal; Lynne Foster; Haina Shin; Amanda L. Lewis
• Keywords: Uterine horns; Escherichia coli infection; Infectious dose

Escherichia coli infection of the female reproductive tract is a significant cause disease in humans and animals, but simple animal models are lacking. Here we report that vaginal inoculation uropathogenic E. strains UTI89 CFT073 non-pregnant, estrogen-treated mice resulted robust colonization vagina uterine horns, whereas titers lab strain MG1655 were significantly lower. Non-estrogenized also became colonized, there was more variation titers. A dose 104 colony-forming units (CFU) sufficient to result all estrogenized mice, observed bacterial transfer between inoculated uninoculated cage mates. led inflammation leukocyte infiltration into horns as evidenced by tissue histology. Flow cytometry experiments revealed neutrophil, monocyte eosinophil populations increased infected horns. This model way study host-pathogen interactions infection. There immediate implications for investigators studying urinary using mouse models, few required achieve colonization, resulting an additional, underappreciated mucosal reservoir.