Disulfiram inhibits bacterial growth by inducing zinc-dependent reactive oxygen species

With the growing threat posed by emerging drug-resistant bacteria, the discovery of new antibiotics and the exploration of additional antimicrobial mechanisms of medicines currently used in the clinic are urgent. In this study, we found that disulfiram, a drug used for the treatment of alcohol addiction, inhibited the growth of multiple bacteria and quickly inhibited the growth of E. coli. When combined with kanamycin or polymyxins in vitro, disulfiram could augment the bactericidal effect against E. coli or A. baumannii. When combined with colistin in vivo, disulfiram also protected against murine E. coli infection. Disulfiram inhibited the motility of E. coli but did not change its length morphologically. Transcriptomic analysis revealed that disulfiram-treated E. coli presented an oxidative stress pattern and zinc-related transcriptomic changes. Moreover, the bacteriostatic effect of disulfiram on E. coli and S. aureus could be fully prevented by the ROS scavenger NAC. In addition, zinc ions increased ROS levels and further suppressed bacterial growth, whereas zinc chelators suppressed ROS and restored the growth of both E. coli and S. aureus. This study reveals that disulfiram inhibits bacterial growth by inducing zinc-dependent intracellular reactive oxygen species (ROS). This bacteriostatic effect can be reversed by ROS scavengers or zinc chelators, highlighting a previously uncharacterized antimicrobial mechanism for disulfiram. E. coli cultures were grown in LB medium to mid-log phase and then divided into two groups: a treatment group and a control group. For the treatment group, E. coli was incubated with disulfiram at a final concentration of 64 μg/mL for 4 hours at 37°C with shaking. The control group received an equal volume of vehicle (DMSO) without disulfiram under identical conditions. Each condition was performed in three independent biological replicates (n = 3). Following treatment, cells were collected for downstream analysis.