Sporulation activity of
strains grown in BHI broth culture. Spore production by strains of C. difficile grown in BHI broth for 24 (A), 48 (B) and 72 hours (C). The total viable count of C. difficile (□) was determined as well as an assessment using alcohol shock (as described in the Materials and Methods) to determine what portion was in the spore form (■). Each bar represents the average of triplicate testing. The 24 hour levels for strain 43255 were tested in triplicate on two separate occasions to verify that spore levels were consistently < 1 Log10.