FIG 1.

Schematic representation of timing of infection and phage dosing in vivo. (A) To determine the impact of the phages on colonization, animals were infected and dosed with a single phage or a combination of phages every 8 h for 36 h. Animals culled at this point showed no symptoms, even though they subsequently showing high levels of bacterial colonization. No toxin was detected in any animal at this time point. (B) To determine the protective efficacy of the phages, animals were infected and treated with the phages as described in the legend to panel A. Treatment was continued until the body temperature of the animal reached 35°C, at which point the animal was culled and the level of colonization of tissue was determined. All animals were made sensitive to C. difficile by oral treatment with clindamycin 5 days prior to challenge with bacterial spores.