Figure 3

Restoration of the culturability of L. pneumophila Philadelphia cells on supplemented medium (BCYES). (A) Number of culturable cells observed on standard medium (□), total cells (○) and culturable cells observed on the supplemented medium (∆) as a function of HOCl concentration (mM). The results reported are means of three independent experiments. Inset shows a magnification of the region of the plots corresponding to HOCl concentrations lower than 0.1 mM. Stars indicate that the number of culturable cells was significantly lower (p < 0.05) than the total number of cells. (B) Restoration ratio (Number of culturable L. pneumophila cells on supplemented medium divided by that on standard medium) as a function of HOCl concentration. The restoration ratio is given above each bar. (C) Number of culturable cells as assessed on the standard medium (□), total cells (○) and culturable cells as assessed on the supplemented medium (∆) as a function of time (h) for cultures in the liquid standard medium (YEC) at 37°C. The results reported are means of three independent experiments (Errors bars = SD). Stars indicate that the number of culturable cells is significantly lower (p < 0.05) than the total number of cells.