A-D (A, B, D) Viability counts of V. parahaemolyticus RIMD 2210633 ∆hcp1 (A), V. alginolyticus 12G01 ∆hcp1/∆hcp2 (B), and V. natriegens (D) prey bacteria before (0 h) and after (4 h) co-incubation with VnatReg attackers harboring the indicated plasmids, on media containing 3% NaCl and 0.1% arabinose at 28 °C. Data are shown as the mean ± SD, n = 3 technical replicates. Statistical significance between samples at the 4 h timepoint by an unpaired, two-tailed Student's t-test is denoted above. A significant difference was considered as P < 0.05. ( C) Illustration summarizing the competitions shown in (A, B). Effector and immunity modules expressed by VnatReg carrying pT6SSEffectorless (yellow) are colored to match the bacterium from which they were derived. 