Fig. 1 |. Vancomycin resistance is enhanced by propionate or vitamin B₁₂ supplementation and is predictive of PDIM production in Mtb.

a, TLC lipid analysis of the PDIM reference strain set (see Supplementary Table 1). b, Metabolic pathways of methylmalonyl-CoA production and propionyl-CoA catabolism. c, Vancomycin resistance of the Mtb PDIM reference strain set in 7H9/OADC/glycerol/tyloxapol + PALM (pantothenate, arginine, leucine, and methionine) media, and additionally supplemented with 0.1 mM propionate (‘VAN-P’ MIC), measured after 7 days incubation. d, Correlation between VAN-P MIC₉₀ from the curve fit in (c) (+ 0.1 mM propionate) and PDIM band intensity from (a). The solid line indicates the linear regression best-fit, and the error bands the 95% CI. e, ‘VAN10-P’ assay comparing growth in 10 μg/ml vancomycin with 0.1 mM propionate to drug-free controls (VAN10 OD / VAN0 OD × 100 = VAN10-P growth%). f, Correlation between VAN10-P growth% from (e) and PDIM from (a). The solid line indicates the linear regression best-fit, and the error bands the 95% CI. g, Vancomycin resistance of PDIM(+) and PDIM(-) Mtb H37Rv strains in standard 7H9/OADC/glycerol/tyloxapol media and supplemented with 0.1 mM propionate or 7.4 μM vitamin B₁₂ (10 μg/ml). *P < 0.001 for both wt and comp versus ΔppsD; two-way ANOVA with Tukey’s multiple comparison test. h, VAN10-P assay of H37Rv strains with tyloxapol or Tween 80. ****P < 0.0001; one-way ANOVA with Tukey’s multiple comparison test. MIC data show mean ± SD for n = 4 biological replicates from two independent experiments. VAN10-P data show mean ± SD for n = 3 three independent experiments, each performed in triplicate.