Figure 1.

phoR mutant of Mtb H37Rv has the same phenotypes as the phoP mutant. (a) Schematic illustration of the phoR mutant design. DNA sequence (∼50 bp) encompassing His259 codon in the phoR gene was replaced by a DNA fragment containing a hygromycin-resistant gene. (b) Sensitivity of the phoP and phoR mutants to vancomycin. Disk diffusion assays were performed to compare the sensitivities of H37Rv, the phoP mutant (ST100),⁷ the phoR mutant (ST163), and the phoR-complemented strain (ST168) to vancomycin (800 ng/μL). Bars indicate the average zones of inhibition in millimeters from three independent experiments, and error bars indicate standard deviations. (c) Growth of Mtb strains in the mouse lung comparing strains of the wild-type H37Rv (solid line with diamonds), phoP mutant ST100 (solid line with squares), and phoR mutant ST163 (dashed line with triangles). (d) Growth of Mtb strains in the mouse lung comparing strains of the wild-type H37Rv (solid line with diamonds), phoR mutant ST163 (dashed line with triangles), and phoR mutant complemented with phoPR (ST184) (solid line with circles). For panels (c,d), each data point is the average of three experiments, and the error bar is the standard deviation.