FIG 5.

Delivery of CAI-1 into OMVs depends on growth conditions. (A) The NL20 reporter strain, which responds only to CAI-1, was incubated with OMVs harvested from V. harveyi MR17 (0.45-μm filtrate). OMVs were harvested after 6, 24, and 48 h of growth in LM or AB medium. QS activation in the reporter strain NL20 was monitored by measuring luminescence. Error bars represent the standard deviations of data from three different experiments. RLU, relative light units, expressed in counts per second per milliliter per OD₆₀₀ unit. (B) Images of fluorescently labeled OMVs of MR17 cells harvested after 6, 24, and 48 h of growth in LM or AB medium. Isolated OMVs were stained with the green fluorescent MitoTracker FM dye, which stains lipids, and imaged using a green fluorescent channel. Each white arrow indicates a single fluorescent OMV, and each black arrow shows its respective position in the phase-contrast image. PH, phase-contrast images. Bar, 5 μm.