抗生素和纳米银对大肠杆菌耐药性的联合效应

以大肠杆菌（E.coli）为模式生物，研究了磺胺类抗生素（SAs）和纳米银（AgNPs）在单一或联合作用下对RP4质粒接合转移效应及E.coli突变效应的影响，并对联合作用方式进行了判别，基于分子对接技术和线性回归分析，探讨了两种效应的机制及其与毒性效应的关系.结果表明，在较低浓度范围内，所测12种SAs以及AgNPs在单一或联合暴露下对接合转移和突变均有促进作用，12组SAs-AgNPs混合物对接合转移频率促进率峰值的最大值和最小值分别为105.32%和46.96%，对突变体促进率峰值的最大值和最小值分别为1410.25%和238.38%.此外，SAs和AgNPs联合暴露对RP4质粒接合转移效应主要表现为协同作用，对E.coli突变效应主要表现为拮抗作用，且接合转移效应、突变效应与毒性效应之间具有良好的相关性.

Joint effects of antibiotics and silver nanoparticles on resistance of Escherichia coli

The effects of sulfonamides (SAs) and silver nanoparticles (AgNPs) on plasmid RP4 conjugative transfer and mutation were investigated using Escherichia coli (E. coli) as model organism. And the combined action modes of the two antibacterial agents were judged. Based on molecular docking and linear regression, the mechanism of the two effects and their relationship with toxicity were discussed. The results showed that the tested 12 SAs and AgNPs could promote conjugative transfer and mutation in the low concentration range whether under single or combined exposure to E. coli. Among the 12 groups of SAs-AgNPs mixtures, the maximum and minimum peak values of conjugative transfer frequency promotion rate were 105.32% and 46.96%, respectively, and the maximum and minimum peak values of mutant promotion rate were 1410.25% and 238.38%, respectively. The joint effects of SAs and AgNPs to plasmid RP4 conjugative transfer and mutation effect were mainly synergistic and antagonistic, respectively. Furthermore, there was a good correlation among conjugative transfer effect, mutation effect and toxicity effect. This paper provides a reference for the study of the emergence and dissemination of bacterial resistance.