Figure 1.

The biofilm mass of Acinetobacter baumannii clinical isolates. To measure the relative amount of the biofilm, the crystal violet stained biofilm was solubilized with ethanol for 5 minutes. Solubilized crystal violet was measured at optical density (OD_570nm) using a Victor 3 microplate reader (PerkinElmer). Biofilm-producing isolates were defined as those wells for which the optical density was higher than the average well optical density for A. baumannii ATCC 19606. The average well optical density for the standard strain of A. baumannii ATCC 19606 was 0.513.