Vibrio cholerae strain BGT49 encodes the Aux 4 T6SS cluster and efficiently eliminates target bacteria in a TpeV- and T6SS-dependent manner. (A) The Aux 4 cluster encodes predicted hcp, vgrG, DUF4123-containing chaperone, effector, immunity, and paar genes. The cluster is found on a predicted mobile genetic element, flanked by integrase and transposase genes. (B) Target V. cholerae BGT49 ΔtpeV ΔtpiV (CC170) was cocultured with either WT, ΔtpeV (CC167), or ΔvasK T6SS− (CC168) BGT49. A one-way analysis of variance (ANOVA) with a post hoc Tukey honestly significant difference (HSD) test was used to determine significance. ****, P < 0.0001.