FIG 1.

ES401 kills ES114 in a T6SS2-dependent manner on agar surfaces and in high-viscosity liquid medium. CFUs of ES114 (cyan) and wild-type (WT) or vasA_2 mutant (T6SS2 mutant [T6⁻]) ES401 (magenta) were determined in coincubation assays performed on agar surfaces (agar) or in low- (liquid) or high-viscosity (hydrogel) liquid medium (A) or in media with a range of viscosities (B). Dashed lines indicate the average number of CFUs at 0 h. The viscosity of liquid medium without PVP (0%) is based on the viscosity of water. Asterisks indicate that ES401 had statistically significantly higher CFUs than ES114 at 12 h (Student's t test, P < 0.03), and daggers indicate that the CFUs for ES114 statistically significantly decreased from 0 h to 12 h (Student's t test, P < 0.0001). Error bars indicate SEMs. Experiments were performed at least three times, and combined data are shown (n = 12).