The genealogy of recombinant strains generated and explored in this study. The figure shows the parental strains used to generate recombinant strains. In each case, the parents in a cross are connected by a horizontal line, and the progeny are at the end of the arrow. In some cases, the progeny of one cross was used as a parent in a subsequent cross. Primary parental strain names includes drug resistance, and all recombinant strains (indicated by prefix RC- ) are both rifampicin and ofloxacin resistant. The colors used indicate the OmpA phenotype of each strain, as determined by fluorescence microscopy and genome sequence analysis. Strains containing the plasmid are shown in bold face and underlined. Crosses involving three parents are not shown because no triply drug resistant strains could be recovered.