Fig. 4 |. Propionate and vitamin B₁₂ supplementation prevent PDIM loss in Mtb.

a, VAN10-P and TLC lipid analysis of PDIM levels in Mtb H37Rv-B following serial passage in 7H9/OADC/glycerol/tyloxapol media ± 0.1 or 1.0 mM propionate. ****P < 0.0001; one-way ANOVA with Tukey’s multiple comparison test. A representative result is shown for one of two biological replicates analysed by TLC (see also Extended Data Fig. 8b). b, VAN10-P assays of H37Rv-A passaged in ± 0.1 mM propionate. Significant differences between successive timepoints for each condition are indicated (**P < 0.01, ****P < 0.0001); two-way ANOVA with Tukey’s multiple comparison test. c, VAN10-P screening of single colonies of H37Rv-A before (n = 38; same data as Fig. 2d) and after propionate passage in (b) (n = 30). Each colony was assayed in triplicate and data points represent mean VAN10-P growth%. Lines indicate the median. P = 0.0047; unpaired two-tailed Mann-Whitney test. d, VAN10-P assays of H37Rv-A passaged in media supplemented with ± 0.1 mM propionate and 7.4 μM vitamin B₁₂ (10 μg/ml) alone and in combination. Significant differences compared to + 0.1 mM propionate are indicated (*P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001); two-way ANOVA with Tukey’s multiple comparison test. P > 0.05 for vitamin B₁₂ versus vitamin B₁₂ + propionate and P < 0.0001 for standard media versus each supplemented condition at all timepoints. VAN10-P data in (a,b,d) show mean ± SD for n = 3 biological replicates, each assayed in triplicate. For some data points the SD is smaller than the data symbols.