Bacterial Spot Assay
Bacterial cell cultures were diluted to final OD600 =
0.125, the first dilution (10-1), and then 10x serial
dilutions were applied. 5µL of each dilution were spotted on LB agar
plates with or without antibiotics (No AB). The sub-MIC (sub-inhibitory)
concentrations of the antibiotics were as follows: 2.5-4 µg/mL
chloramphenicol; 0.5-1 µg/mL tetracycline; 25-40 µg/mL erythromycin; 50
µg/mL clindamycin; 100 µg/mL fusidic acid; 10 µg/mL mupirocin; 0.5 µg/mL
tobramycin or amikacin; 2.5 µg/mL rifampicin or streptomycin. The plates
were imaged using an Epson Expression 1680-pro scanner. In Fig. 9D, R2A
agar (VWR, #84671.0500) plates were used to test the slow regrowth of
bacterial cells from the MOPS minimal medium. R2A Agar is a low-nutrient
medium, and in combination with a longer incubation time, it stimulates
the growth of stressed bacteria.