FIG 6 .

Only YB variants persist in the gastrointestinal (GI) tract of mice. BALB/c mice were infected with ~10⁴ CFU of B. pseudomallei orally: WHT (white circles; 2.2 × 10⁴ CFU), YA (yellow squares; 8.3 × 10³ CFU), and YB (orange triangles; 5.7 × 10³ CFU). Bacterial burdens were determined in mice surviving 66 or 71 days postinfection (WHT, n = 5; YA, n = 3; YB, n = 6). Bacterial burdens in stomach, distal GI tract (small intestine, cecum, and colon), feces, lung, liver, and spleen were determined. Data are graphed as individual values with bars representing the mean log₁₀ CFU/organ titer (feces = log₁₀ CFU/gram). The limit of detection for lung, liver, and spleen was 10 CFU/organ; that for stomach and distal GI tract was 1 CFU/organ; and that for feces was 10 to 20 CFU/g. Data were pooled from two independent experiments. *, YB caused chronic infection relative to the combined WHT and YA morphotypes (P = 0.044).