Fig. 2.

The growth status of different strains on the TSA medium with Cr(VI) and/or ampicillin added. The control means no Cr(VI) or ampicillin was added. ATCC stands for strain S. aureus ATCC25923, LZ-01 stands for strain S. aureus LZ-01, CA and CB are complemented strains for deletion mutant strain ΔemrA and ΔemrB. Cultures of different strains were diluted to tenfold gradients. 3 µl of each gradient culture was inoculated on to plate in a line, and different strains were inoculated in a column. All the plates were incubated in 37 °C for 12–18 h