Ex vivo bioluminescence imaging of late gestation ewes following intrauterine inoculation with lux-modified Escherichia coli.

Abstract Our objectives were to develop an ovine model for Escherichia coli -induced preterm delivery, and monitor E. coli (lux modified for photonic detection) invasion of the fetal environment—ewes (124 ± 18 d of gestation) received intrauterine inoculations using E. coli -lux as follows: control ( n  = 5), 1.2 × 10 6  CFU/ml ( n  = 5), 5.6 × 10 6  CFU/ml ( n  = 5) E. coli -lux. Preterm delivery occurred between 48 and 120 h post-inoculation in 60%, 60% of ewes infected with 1.2, and 5.6 × 10 6  CFU/ml E. coli -lux, respectively, with presence of emitting bacteria confirmed by real-time imaging of lamb tissues. In summary, preterm delivery and/or fetal distress were observed in a majority of inoculated ewes. Finally, the use of photonic bacteria with imaging was a feasible means to monitor bacterial presence ex vivo .