Effective methods for the inactivation of Francisella tularensis
Fig 2
Heat inactivation of F. tularensis SCHU P9.
Bacterial suspensions were prepared with deionized water, CDM, PBS, and undiluted FBS. (A and B) The samples were heated at 94°C for 3 min (A) and 56°C for 30 min (B) and then immediately cooled on ice. The control samples were cooled to 4°C for 3 min (A) and 30 min (B). The black and white bars indicate the CFU numbers of the treated and control samples, respectively. Statistical significance was determined by one-way ANOVA with a post hoc test (*p < 0.05, **p < 0.01 and ***p < 0.001). (C and D) Bacterial suspensions heated at 94°C (C) and 56°C (D) for the indicating times in the figure were immediately cooled on ice. In contrast, the control samples were cooled on ice for identical time periods. The white and black symbols indicate the CFU numbers of the treated and control samples, respectively. In all experiments, the CFU number of four replicates of each bacterial sample was counted. The mean CFU ±SD are shown. Statistical significance was determined by two-way ANOVA with a post hoc test (*p < 0.05, **p < 0.01 and ***p < 0.001).