Effect of carolacton on cell morphology and viability. Fluorescent phase-contrast images of planktonically grown cultures (A, B) and biofilm cells of S. mutans (C, D) after LIVE/DEAD staining without (A, C) and in the presence of 5.3 μM carolacton (B, D). Planktonic cultures were grown in THB. Biofilms were grown in THB supplemented with 0.5% sucrose on microtitre plates for 24 h hours. Cultivation was at 37°C under anaerobic conditions (80% N2, 10% H2, 10% CO2). For microscopy, biofilm cells were scraped off from the bottom of the wells using pipette tips. Samples (100 μl) were stained with LIVE/DEAD BacLight bacterial viability staining kit L13152 (Molecular Probes; Eugene, OR, US) as recommended by the manufacturer and analysed using an Olympus BX60 microscope equipped with fluorescence filters U-MWB and U-MNUA2 and the Olympus digital camera Color View II (Olympus Optical Co., Ltd. Germany). Arrows (B, D) indicate bulging cells.
Kunze et al. BMC Microbiology 2010 10:199 doi:10.1186/1471-2180-10-199