Another important question regarding T6SS-mediated bacterial virulence is whether V52 is capable of distinguishing self from nonself. The killing assay was performed using rifampicin-resistant isolates of selected V. cholerae serogroups as prey and measuring survival following exposure to a rifampicin-sensitive predator V52 and V52ΔvasK. As prey, V52 and V52ΔvasK were unaffected by wild-type V52 exposure, whereas E. coli suffered a reduction of >1,000-fold (Fig. 7). Survival of O1 serogroup representatives, including the seventh pandemic El Tor strains N16961 and C6706, and the classical O395 strain was not significantly affected by exposure to wild-type V52 (Fig. 7).