Figure 4.

LF and LFpeptides cause ultrastructural damage to Vibrio cholerae non-O1 cells. V. cholerae non-O1 cells (1.0 × 10⁸ cells/ml) were incubated in LB alone (negative control for damage) or with 0.5% SDS (positive control for damage) or with 40 μM of bLF, or 20 μM LFcin 17-30 and LFampin265-284 respectively, or 5 μM LFchimera, for 1.5 h at 37°C. Cells were harvested, resuspended in PBS and fixed with 4% para-formaldehyde plus 0.5% glutaraldehyde. Next, bacterial samples were placed on 200-mesh Formvar-coated copper grids (3%), post-stained with phosphotungstic acid and examined with a JEOL electron microscope JEM1400 at 40 kv.