Fig. 5. No evidence for cost of plasmid carriage for transconjugants.

A, B We measured plasmid cost for ten strain-plasmid combinations, with three independently isolated transconjugants each (n = 4; beams are mean values ± SEM). Transconjugants and their plasmid free complements grew in independent cultures and we calculated the relative growth by dividing the transconjugant growth rates (h⁻¹) by the mean growth-rate of plasmid-free strains. C We performed the competition experiment by colonising the mice with a 1:1 mix of a non-conjugative transconjugant (oriT-knockout) and recipient RE3 (n = 6; 3 independent transconjugants, n = 2 for each). C Kruskal–Wallis test p > 0.05 (ns), p < 0.01 (**).