Fig. 1. Schematic depicting experimental design and conjugation results of ARGs induced by OTC and heavy metals.

a Schematic experimental design of the conjugation. b Fold change of conjugation frequency of RP4 plasmid in E. coli K12 under OTC and heavy metal. c Fold change of transconjugant number under antibiotic and heavy metal. Significant differences between individual exposure groups and the control were tested with the independent-sample t test: *(p < 0.05).