Fig. 5.

Susceptible cells increase in aspect ratio before outcompeting resistant cells in carbenicillin-treated colonies. Yellow susceptible and red resistant cells were competed on either 12 μg/ml carbenicillin (red) or no antibiotic (black). The edge of these colonies was then imaged during growth to measure cell length and relative cell numbers (a, b). The bottom images are micrographs of the colony edge under the different conditions showing the shifts in aspect ratio in susceptible cells, in the presence of resistant cells, during carbenicillin treatment (c). The mean and standard error of two experiments, each with n = 3, are shown. (Colour figure online)