Transcriptional modifications enhance the persistence of resistant plasmids in the presence of tetracycline in an environmentally relevant concentration.

Antibiotic resistance genes (ARGs) have captured immense attention due to their widespread existence and remarkable ability to spread across species boundaries. Plasmid carriage promotes the persistence and spread of ARGs in the environment. To investigate the prevalence of plasmids, we conducted serial passage experiments on Pseudomonas putida KT2442 with multidrug-resistant plasmid RP4::gfp in the presence of tetracycline (TC) in an environmentally relevant concentration. The results showed that TC in environmental concentration compensated the fitness cost brought by the plasmid, prolonged the persistence time of the plasmid-bearing strain, and induced the reoccurrence of plasmids after the window time of plasmid loss. Transcriptome sequencing showed that plasmid recovery was compensated by the up-regulation of glyoxylic acid shunt and the down-regulation of ribosome biosynthesis. It is therefore hypothesized that transcriptional modifications may enhance the persistence of resistant plasmids within the population in the presence of TC in an environmentally relevant concentration. This work opens up an avenue for developing a technology based on the window time of plasmid loss to prevent the spread of ARGs.