Fig. 4

Kinetics of UAMS-1 in the in vitro biofilm formation on stainless steel. Bioluminescent UAMS-1 (Xen40) was inoculated (1 × 10⁶ cfu/ml) in the flow chamber containing TSB + HP and stainless-steel pins, which were harvested at the indicated time (n = 4). A Heat map images of the harvested pins in a microtiter plate during bioluminescent imaging (BLI exposure time 60 s, colour scale 1e5–1e6). B Quantification of the BLI signal (p/s/cm²/sr logarithmic scale) in the 1 cm² ROI is presented as the mean +/− SEM (*p < 0.05). C Representative SEM images of the pin are shown at 80x (left), and the ROIs containing biofilm (red box) are shown in the SEM at 5000x (right). Note that a significant biofilm in the form of a precipitated matrix was formed immediately (0 h), while bacterial adherence to this matrix did not occur until 6 h, and biofilm formation peaked at 9 h