FIG. 7.

Influence of AI from strain 13-6 (entA⁺ parent) and AN193 (entA mutant) prepared from bacteria grown in iron-limited, mM9 on the growth of JPN10 in SAPI+serum. mM9 was modified as described in the Materials and Methods to support the growth of strain 13-6 and AN193. Uninoculated mM9 medium was used as a control. Spent culture supernatants from strain 13-6, AN193 and uninoculated mM9 medium were acidified and extracted with ethyl acetate, the solvent was removed, and the residue obtained was redissolved in mM9 medium to the original volume. Bacteria were incubated for 24 h at 37°C in a humid atmosphere containing 5% CO₂, after which each sample was enumerated for viable counts. Each bar represents the mean ± the SD of triplicate samples. LOD, limit of detection.