1. Mixed head-to-head competitions.
Mixed head-to-head competitions. Strains were mixed in a 1:1 ratio and grown together overnight. Ratios before and after incubation were determined by selective plating. For bar 1, MP100 (E. coli MG1655) competed with MP101 (E. coli MG1655 carrying p _3_OXA-48) demonstrated no initial cost of the native OXA-48 plasmid. For bar 2, competitions of MP100 (E. coli MG1655) with MP103 (MP101 subjected to CAZ-AVI) resulted in a high fitness cost of 18% for the strain subjected to CAZ-AVI. For bars 3 and 4, comparisons of MP101 versus MP107 (E. coli MG1655 transformed with p _3_OXA-48-CAZ) and MP108 (E. coli MG1655 transformed with p _3_OXA-48-CAZ-AVI) demonstrated significant costs of 14% and 3%, respectively. All measurements were done at least in triplicates. Statistically significant results are marked with asterisks. Strain abbreviations are listed in Table 1.
Christopher Fröhlich et al. mSphere 2019; doi: /mSphere