posted on 2024-03-06, 20:15authored byYue Wang, Jie Yang, Rong Zhao, Shuai Zhang, Jianhua Guo, Jie Wang
Nonantibiotic
pharmaceuticals are widely used to treat various
human diseases and can also be ubiquitously detected as emerging contaminants
in the environment, thus coexisting with various environmental bacteria.
Previous studies have shown that several nonantibiotic pharmaceuticals
can trigger mutation and promote horizontal transfer of antibiotic
resistance genes between bacteria. However, it is still unclear whether
nonantibiotic pharmaceuticals have an antibiotic-like antimicrobial
activity against environmental bacteria. In this study, we investigated
the antimicrobial effects of four typical nonantibiotic pharmaceuticals
(gemfibrozil, ibuprofen, propranolol, and sertraline) against environmental
bacteria and the evolution of bacterial antibiotic resistance when
challenged with these nonantibiotic pharmaceuticals. Surprisingly,
all four pharmaceuticals exhibit antibacterial activity through a
mechanism similar to that of antibiotics. They can increase reactive
oxygen species production and enhance membrane permeability up to
2.7- and 2.4-fold, respectively. The expressions of sodA, sodB, and recA genes related
to reactive oxygen species detoxification and SOS response were upregulated.
We also found that these pharmaceuticals can upregulate the expression
of the efflux pump gene tolC with 2.5-fold to promote
the evolution of bacterial antibiotic resistance. This study provides
insights into the role of nonantibiotic pharmaceuticals in the emergence
of antibiotic resistance and highlights the negative effects of nonantibiotic
pharmaceuticals on environmental bacteria.