Figure 1: Thermal testing of a collection of C. difficile indicates temperature-dependent survival trends favoring PCR ribotype 078 strains at subboiling temperatures. Time and temperature of heating treatment of spore suspensions in PBS were significant predictors () for spore survival reduction and switch in survival trends (odds ratio, OR). Comparing 078 with non-078 ribotypes, OR = 1 indicates that both groups would be equally likely to survive; OR > 1.0 indicated ribotype 078 was (2.3–2.8 times) more likely to survive (high heat, 96°C); OR < 1.0 indicated other non-078 PCR ribotypes would be would be (0.2–0.4 times; 1-OR) more likely to survive.