FIG. 4.

Results of antibacterial activity assays. (A to C) Antibacterial liquid broth coincubation assay. E. coli (A), S. aureus (B), and P. aeruginosa (C) were added (10³ to 10⁴ CFU) to 50 μl of lysates from cells transfected with a vector containing the full-length cDNA of mBD-1 (empty circles) or with the vector alone (filled circles) and analyzed for microbial killing. Each circle represents results from an individual transfection experiment. (D) Salt sensitivity of the antimicrobial activity of mBD-1. Extracts from mBD-1-transfected cells were incubated with 5 × 10⁴ CFU of E. coli D31 in 10 mM phosphate buffer (pH 7.4) and the indicated concentrations of NaCl. After incubation at 37°C for 1 h, serial dilutions were plated and colonies were counted the following day.