FIG 2.

Media that limited nutrients or compromised LPS allowed JAV1 and JAV2 to inhibit S. Typhimurium growth in broth, but neither compound permeabilized outer membranes. (A) Growth of S. Typhimurium in different media with JAV1 (left) or JAV2 (right). Absorbance (OD₆₀₀) values were normalized to that of DMSO (100%; black square). MHB (red) or M9 (blue) was supplemented as indicated by the keys with polymyxin B (PMB, 1 μg/mL), polymyxin B nonapeptide (PMBN, 30 μg/mL), or EDTA (400 μM, 117 μg/mL). Means and SEM of three biological replicates performed in technical triplicate are shown. IC₅₀ values are indicated in the key in parentheses. (B to D) Mid-log-phase S. Typhimurium cultures were combined with 100 μM nitrocefin and DMSO (B), PMB (C), or JAV1 (left) or JAV2 (right) (D) in the indicated media and monitored for absorbance (at 486 nm) over 55 min to calculate the slopes (relative fluorescence units [RFU] per minute). Means and SEM of three biological replicates performed in technical triplicate are shown. Data in panelsC and D were normalized to DMSO. For data in panels B to D, * indicates P < 0.05 (determined by ordinary one-way analysis of variance [ANOVA] and Tukey’s multiple-comparison test) and ns indicates nonsignificant. The overall P and F values and total degrees of freedom were as follows: 0.0141, 9.4, and 3 (B); <0.50, 3.79, and 2 (C); 0.2, 1.7, and 2 (D), respectively.