FIGURE 7.

Rev1Δwzm has larger particle size than Rev1, but both perform similarly in the in vitro growth curves and environmental susceptibility. (A) Bacterial growth curves determined by the number of viable cells (CFU/ml; the left axe, large symbols) and medium absorbance (OD₆₀₀; the right axe, small symbols). (B) Particle size values measured by Zetasizer (μm). Percentage of bacterial inhibition by: (C) Desiccation, (D) Detergents (0.1% Triton X-100), (E) Oxidative (H₂O₂), and (F) Acidic pH pressures, as models of stress encountered by Brucella in the natural environment and in the host niche. All results are expressed as the mean ± SD of at least three measures; strains Rev1, 16M, and 16MΔwzm were included as controls in all the experiments; the percentages of surviving bacteria (%) were determined with respect to the initial suspension. Fisher’s LSD test; ^***p ≤ 0.001, ^**p ≤ 0.01 vs. the indicated groups.