Loss of spore OD<sub>600</sub> of <i>C. difficile</i> isolates during incubation in A) BHIS supplemented with taurocholate and chenodeoxycholate; B) BHIS supplemented with taurocholate; or C) BHIS alone. HeegDaniela A. BurnsDavid T. CartmanStephen P. MintonNigel 2013 <p><i>C. difficile</i> spores were heat treated at 60°C for 25 min and then incubated in BHIS with or without supplement. Germination was expressed as the loss of spore OD<sub>600</sub>. A) Loss of OD<sub>600</sub> of spores of <i>C. difficile</i> isolates incubated in BHIS supplemented with 0.1% (w/v) taurocholate and 2 mM chenodeoxycholate. ▴, DH1834; ▾, 5108111; •, 9001966; ▵, 26131; ○, 7004578; ◊, CD 2315; and ▿, CDC38. The dotted line represents the loss of OD<sub>600</sub> of the positive control strain (05-1223-046) in response to BHIS supplemented with 0.1% (w/v) taurocholate alone. B) Loss of OD<sub>600</sub> of spores of <i>C. difficile</i> isolates incubated with BHIS supplemented with 0.1% (w/v) taurocholate. ▴, DH1834; ▾, 5108111; •, DH1432; ▵ 05-1223-046; □, CD 2315; ▿, CDC 38; and ○, DH1858. The dotted line represents the negative control strain (DH361) during incubation with both 0.1% (w/v) taurocholate and 2 mM chenodeoxycholate (a strain found, in preliminary studies, not to germinate when exposed to chenodeoxycholate). C) Loss of OD<sub>600</sub> of spores of <i>C. difficile</i> isolates incubated with BHIS alone. ▴, DH1834; ▾, 5108111; •, 8085054; ▵, 05-1223-046; ○, 26173; and ▿, CDC38. The dotted line represents the loss of OD<sub>600</sub> of the positive control strain (05-1223-046) in response to BHIS supplemented with 0.1% (w/v) taurocholate alone. All data represent the average of three independent experiments and error bars indicate the standard errors of the means.</p>