Fig. 1

Intracellular survival of Burkholderia strains in mouse macrophages. J774A.1 mouse macrophages were exposed to B. thailandensis strain E555 at an MOI of 10 for 2 h. Following removal of the extracellular bacteria, infected macrophage cells were incubated with kanamycin (1 mg/ml in the first 2 h and 0.25 mg/ml afterwards) for 1, 2, 4 and 6 h and the mean numbers (with standard errors of the mean) of intracellular bacteria were determined. B. thailandensis strain E264 and B. pseudomallei strain K96243 values were adapted from Wand et al. [39]. There was no statistically significant difference between the growth rate of B. thailandensis strain E555 and B. thailandensis strain E264, or between the growth rate of B. thailandensis strain E555 and B. pseudomallei strain K96243 at any time point (p > 0.05). In contrast, the difference between the growth rate of B. pseudomallei strain K96243 and B. thailandensis strain E264 was significant: p < 0.001 at 4 h, 6 h and 8 h post-infection, (indicated by ***)