Fig. 4: Bubble plot showing the number of genotypic resistances (in red) and compensatory mutations (in blue) as a function of strain’s years of isolation of all W148 strains (n = 720).

Bubble sizes are proportionate to the number of strains. Regression analyses (least square approximation) were significant (P < 2.2 × 10−16) and regression curves are shown on the plot.