FIG 1.

Antimicrobial activity of strain 24613 fonticin particles on a susceptible Pragia fontium strain. (A) Fonticin preparation was 5-fold serially diluted (see labels), and 5 μL of each dilution was spotted on LB top agar with susceptible strain of Pragia fontium 24647. The highest concentration applied (2.5 mg/mL) corresponds to the original fonticin preparation. The lowest concentration (0.8 μg/mL), which produced a visible spot, is shown. More diluted samples did not inhibit bacterial growth (not shown). Representative results from at least five separate spot tests are presented. (B) Killing activity of fonticin particles shown by cell survival assay. Susceptible cells of P. fontium 24647 were 10-fold serially diluted (from OD₄₅₀ of 0.2 to 0.002) and incubated with fonticin particles (24613) with increasing concentrations (0, 1, 3, 10, 30, and 100 μg/mL) and spotted on the LB agar plate directly (3 μL).