FIG. 3.

Host transmission of C. difficile via supershedding mice and environmental spore contamination. (a) Transmission efficiency, indicating the percentage of naïve mice that acquired C. difficile infection from donor mice. The number of naïve mice housed with no donor was 10, the number of naïve mice housed with carrier mice was 15, and the number of naïve mice housed with supershedding mice was 20. (b) Percentage of naïve mice that acquired C. difficile infection from a spore-contaminated environment. The number of naïve mice housed in a contaminated environment with no sporicide was 15, the number of naïve mice housed in a contaminated environment treated for 1 min with sporicide was 10, the number of naïve mice housed in a contaminated environment treated for 5 min with sporicide was 10, and the number of naïve mice housed in a contaminated environment treated for 20 min with sporicide was 10. Groups of 5 or 10 naïve mice were housed in cages previously contaminated by supershedders. The transmission efficiency was determined as described in Materials and Methods.