FIG 2.

Effect of 10 laboratory conditions on colony morphotype switching between nonmucoid and mucoid colonies for 5 paired B. pseudomallei isolates. (A) Colony switching from starting nonmucoid type to mucoid type. (B) Colony switching from starting mucoid type to nonmucoid type. Two hundred microliters of 1 × 10⁸ CFU/ml suspension was inoculated into 2 ml DW or TSB and incubated under one of these following conditions: (i) DW at 37°C for 24 h, (ii) TSB (pH 7.4) at 37°C for 24 h, (iii) TSB (pH 4.0) at 37°C for 24 h, (iv) TSB (pH 8.5) at 37°C for 24 h, (v) TSB (pH 7.4) at 42°C for 24 h, (vi) TSB (pH 7.4) plus 350 mM NaCl at 37°C for 24 h, (vii) TSB (pH 7.4) plus 50 mM NaNO₂ at 37°C for 24 h, (viii) TSB (pH 7.4) plus 2 mM H₂O₂ at 37°C for 24 h, (ix) TSB (pH 7.4) at 37°C for 24 h in an anaerobic jar (Oxoid, United Kingdom), and (x) TSB (pH 7.4) at 37°C for 7 days. Morphotype switching is presented as the proportion (percentage) of the alternate type in relation to the total number of colonies present. Error bars are standard deviations.