FIG 1.

Selection by inducible effectors. (A) Design of the SIE1 dual effector negative selection cassette. Antibacterial effectors are localized to the periplasm via signal sequences (ss), under the control of independent aTC-inducible promoters. (B) Dual effector selection efficiency across human gut Bacteroides species. Type strains are underlined; strains isolated directly from human donors are indicated by superscript donor numbers. The 16S rRNA-based phylogeny is shown at the bottom. Data represent means and standard deviations from triplicate experiments. theta, thetaiotaomicron; frag, fragilis.