Figure 2.

Sample biofilm‐oriented antiseptics test (BOAT). The bottoms of the indicated wells of the microtitre polystyrene assay plate are coated with bacterial biofilm. The dark red colour of the wells means that the bacteria in the biofilm form survived the treatment with the antiseptic within the contact time, whereas the lack of red colour is equivalent to a complete eradication of the bacteria forming biofilm in the well. Line 1 – positive control (biofilm untreated with antiseptic), confirming the ability of the tested strain 2034 to form biofilm at the bottom of the well; line 2 – negative control wells filled with the medium (no biofilm) confirming sterility of the assay performed; line 3: wells A, B, C – strain 2034 treated with octenidine for 1 minute; wells D, E, F – the same strain treated with PVP‐iodine; wells G, H, I – strain treated with ethacridine. Analogically, the biofilm from wells in lanes 4 and 5 was treated with the above‐mentioned antiseptics for 15 and 30 minutes, respectively.