Fig. 4.

The relative expression levels of individual mRNA encoding strain-specific proteins in H37Rv (white), Beijing (gray) and MDR-Beijing (black) through quantitative RT-PCR. The expression levels were determined following culture for 4 weeks in conditions of multiple stressors, compared to the expression levels in control growth conditions. The data presented are means of expression fold-change normalized by the expression level of 16S rRNA. *: p < 0.05; **: p < 0.01; ***: p < 0.001 (T-test comparing the multiple stresses culture versus the control culture of each strain).