Fluorescence Microscopy. V. cholerae strains V52/pBSW208lacP::GFP and V52ΔvasK/pBSW208lacP::GFP were grown overnight on LB agar containing 100 μg·mL−1 ampicillin and 1.2 mM isopropyl-β-D-1-thio-galactopyranoside (IPTG). MG1655/pTV-mCherry was grown overnight on LB agar containing 100 μg·mL−1 ampicillin. Predator and prey were mixed as described in the killing assay at an MOI of 0.1. Twenty-five microliters of the bacterial mixture was spotted onto prewarmed LB agar containing 100 μg·mL−1 ampicillin and 1.2mMIPTG and incubated at 37 °C for 4 h. Bacterial spots were washed in 1× PBS once and fixed in 4% paraformaldehyde for 1 h at room temperature. For
microscopic examination, 1.5 μL of liquid culture was spotted onto a glass slide. Samples were examined using a Zeiss Axioskop2 plus fluorescent microscope and imaged with an AxioCam MRc camera, using Zeiss AxioVision software (AxioVs40 V 4.6.1.0).