The mixture toxicity of environmental contaminants containing sulfonamides and other antibiotics in Escherichia coli: Differences in both the special target proteins of individual chemicals and their effective combined concentration.
Organisms in the environment are exposed to mixtures of multiple contaminants, leading to serious environmental harm. These mixtures pose an ecological risk and have attracted an increasing amount of attention; however there has been little in-depth research the toxicity of mixtures, such as antibiotics. To determine how different mixtures of antibiotics affect organisms, the individual and mixture toxicity of sulfonamides and several antibiotics were determined using Escherichia coli as a target organism in our study. The results show that additive effects occur between sulfonamides and quinolones or with a portion of β-lactams, synergistic effects appear between sulfonamides and their potentiators or cefotaxime sodium, and antagonistic effects arise between sulfonamides and tetracyclines or penicillin V potassium salt. In addition, the toxicity mechanism of binary mixtures is further discussed and the results reveal that the joint effect differences depend not only the target proteins of individual chemicals but also on their effective combined concentration based on the approach of Quantitative Structure Activity Relationships (QSARs) and molecular docking. This study introduces the concept of the "effective concentration" to provide insight into understanding the mechanism of binary mixtures, which will be beneficial for evaluating the ecological risk of antibiotics.
State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China.
Xi
X
Long
State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China.
Dali
D
Wang
State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China; Shanghai Key Lab of Chemical Assessment and Sustainability, Shanghai, China; Collaborative Innovation Center for Regional Environmental Quality, Beijing, China. Electronic address: lzhifen@tongji.edu.cn.
Zhifen
Z
Lin
State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China.
Mengnan
M
Qin
State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China.
Chunlei
C
Song
Shanghai Key Lab of Chemical Assessment and Sustainability, Shanghai, China.
Ying
Y
Liu
D000900:Anti-Bacterial Agents / Q000737:chemistry*; D004463:Ecology; D004785:Environmental Pollutants / Q000737:chemistry; D004926:Escherichia coli / Q000187:drug effects*; D016014:Linear Models; D015233:Models, Statistical; D062105:Molecular Docking Simulation; D021281:Quantitative Structure-Activity Relationship; D018570:Risk Assessment; D000077145:Sulfanilamide; D013424:Sulfanilamides / Q000737:chemistry; D013449:Sulfonamides / Q000737:chemistry*; D013754:Tetracyclines / Q000737:chemistry
D000900:Anti-Bacterial Agents; D004785:Environmental Pollutants; D013424:Sulfanilamides; D013449:Sulfonamides; D013754:Tetracyclines; D000077145:Sulfanilamide
Antibiotics; Effective concentration; Mixture toxicity; Molecular docking; QSAR