Figure 1.

E. coli cells are protected against V. cholerae T6SS attacks when co-cultured in the presence of glucose. (a) E. coli MG1655 cells were co-cultured for 3 h with either killer T6SS+ or defective T6SS- V. cholerae C6706* cells on LB or LBG plates. The number of recovered chloramphenicol-resistant E. coli cells was determined by counts of colony forming units (CFUs) after co-culture mixtures were diluted and spread on chloramphenicol plates. A two-way ANOVA with a Bonferroni post hoc test was performed to determine significance. A minimum of 3 independent replicates were analyzed. (b) The same competition assay was performed as described above. However, the number of recovered killer V. cholerae C6706* cells was determined instead. A Welch’s t-test was performed to determine significance. A minimum of 3 independent replicates were analyzed. (c) V. cholerae C6706* cells grown overnight in liquid LB or LBG were co-cultured with E. coli on solid LBG or LB media, respectively, followed by dilution and plating as described in the “Methods” section. ****p < 0.0001, NS not significant.