Acetaminophen promotes horizontal transfer of plasmid-borne multiple antibiotic resistance genes

Abstract

The emergence and increasing prevalence of antibiotic resistance pose a global public risk for human health, among which plasmid-mediated horizontal gene transfer (HGT) play an important role in this process. However, the relationship between non-antibiotic drugs and dissemination of antibiotic resistance genes (ARGs) in the environment is still poorly understood. Herein, we aimed to investigate the roles of acetaminophen, one of the most common antipyretic analgesics worldwide, in the conjugative transfer of plasmid-borne ARGs. Using the engineering bacteria Escherichia coli DH5α carrying the RP4-7 plasmid as donor bacteria and E. coli EC600 as recipient bacteria, we found that acetaminophen at low concentrations including environmentally relevant concentrations significantly promoted the plasmid-mediated conjugative transfer. Similar promotion effects were also observed in various clinical plasmids that carrying mcr-1 or tet(X4), two critical resistance determinants that confer bacterial resistance to colistin and tigecycline, respectively. Further mechanistic experiments suggested that acetaminophen supplementation increased cell membrane permeability, stimulated ROS production, induced SOS response and strengthened conjugation bridge, thereby collectively contributing to the enhanced conjugative transfer. Thereafter, validated by RT-PCR, the expression levels of genes related to these manners above were conspicuously upregulated after exposure to acetaminophen. Taken together, our study demonstrated that acetaminophen could drastically accelerate the conjugative transfer in bacteria. These findings provide new insights into the spread of ARGs and imply a potential risk elicited by the use of acetaminophen in the clinical setting.