Kanamycin does not improve P. aeruginosa H1-T6SS mediated bacterial competition.
E. coli cells carrying the pCR2.1 vector were co-incubated with either P. aeruginosa PAK wild type (top row), or PAKΔretS (bottom row). The competition assay was carried out as previously described  on LB plates without antibiotics, or in the presence of kanamycin at a concentration of 50 µg/ml for five hours. Following competition cells were harvested and resuspended in LB broth, and a dilution series ranging from 10° to 10-3 was plated in triplicate onto LB plates, as indicated in the white boxes in each corner. Competition assays performed without kanamycin are shown on the left, while those with kanamycin are on the right. Visualisation of a blue colour gives a qualitative indication of E. coli survival.