Figure 3.
Fitness effects of newly acquired and evolved vanA plasmids in E. faecium 64/3. TC7vanA, TC10vanA and TC12vanA with newly acquired vanA plasmids were competed against the plasmid-free but otherwise isogenic E. faecium 64/3. The evolved TC7vanA EV, TC10vanA EV and TC12vanA EV were competed against the evolved plasmid-free E. faecium 64/3. The initial fitness costs of plasmid carriage were reduced in TC7vanA EV (P ≤ 0.01) and TC12vanA EV (P ≤ 0.04). Bars for TC7vanASS, TC10vanASS and TC12vanASS show the fitness effects of evolved plasmids reintroduced into the ancestral E. faecium 64/3SS. A relative fitness below 1 indicates a fitness burden associated with plasmid carriage. Competitions were performed in triplicate and repeated at least twice.