Figure 1.

Intravaginal bioluminescent Escherichia coli K1 A192PP-lux2 (E. coli K1) can ascend into the pregnant uterine cavity and induce premature delivery (30). (A) Pregnant mice received intravaginal E. coli K1 on embryonic day 16.5, bacteria ascend into the uterine cavity over 24 h. (B) At 18 h after E. coli K1 administration bacteria is seen specifically within the pregnant uterine cavity and is detected in the fetal membranes, the placenta and the amniotic fluid by 18 h. (C) By 24 h, bacteria is detected in the fetus. (D) Immunohistochemical detection of E. coli in the fetus shows E. coli specifically within the lung alveoli and small intestine at 24 h, whilst no E. coli is seen in the uninfected fetus (sections counterstained with haematoxylin), n = 3, Scale bar 40 μm. (E) By Postnatal day 1 (72 h after infection), E. coli is clearly seen in the Gastrointestinal tract.