Invasion of A549 epithelial cells by B. pseudomallei. A549 cells were infected with an overnight cultures of B. pseudomallei K96243 grown in in NaCl-free LB broth (open bar), LB broth with 170 mM NaCl (solid bar), or LB broth with 320 mM (striped bar). Intracellular bacteria were counted after lysing infected cells at 4 hrs-post-infections. Asterisks indicate significant differences (P value < 0.05, t-test) between groups. Error bars represent standard errors of the means for experiments performed in triplicate.