Fig. 1.

Growth of carbenicillin-adapted E. coli O157:H7 strains to 7 μg/mL (a), 15 μg/mL (b) or 25 μg/mL (c) of carbenicillin by successive passages in TSB supplemented with antibiotic at the specified concentration (n = 4). Bacteria were incubated at 37 °C and 1/100^th dilution was carried out from the culture at OD₆₀₀ ≈ 1 and then sub-cultured for the next passage. 200 μL of each cell culture were used for growth monitoring.