Journal: Microbiology Spectrum
Article Title: Selective Pressure by Rifampicin Modulates Mutation Rates and Evolutionary Trajectories of Mycobacterial Genomes
doi: 10.1128/spectrum.01017-23
Figure Lengend Snippet: Mutations in rpoB in the MA lines: identification and effect on antibiotic resistance. (A) Types of RNAP β substitutions generated by rpoB mutations. M. smegmatis RNAP β is represented with amino acid numbering. Gray regions indicate the rifampicin resistance clusters described in E. coli ( , ). Amino acid substitutions generated by rpoB mutations in the MA lines are shown in blue (wild-type lines) and orange (Δ nucS mutant lines). Mutations associated with resistance in M. tuberculosis by the WHO catalogue are marked with asterisks. Below are shown protein alignments of RNAP β of M. smegmatis ( Msm ), M. tuberculosis ( Mtb ), and E. coli , with the amino acid positions where mutations were detected (red). (B) Effect of RNAP β substitutions on rifampicin resistance. Bars show the rifampicin MIC of the MA lines before (light purple) and after (dark purple) the acquisition of each rpoB mutation. When the rpoB mutation was present in more than one line (H442R and G450D), a representative example is shown. *, S438L substitution appeared together with V167M at the same week of the evolution.
Article Snippet: M. smegmatis wild-type strain mc 2 155 (American Type Culture Collection; 700084) and its noncanonical MMR-deficient (Δ nucS mutant) derivative ( ) were grown at 37°C in Middlebrook 7H9 broth or 7H10 agar (Difco) with 0.5% glycerol and Tween 80 (0.05% in 7H10 agar and 0.5% in 7H9 broth).
Techniques: Generated, Mutagenesis