Combined Induction Effects of Quorum Sensing Inhibitors and Quinolones on Escherichia coli RP4 Plasmid Conjugative Transfer
SHEN Hongyan
RAN Zhaodong
YANG Lei
YANG Jingpo
SUN Haoyu
TANG Liang
Abstract：Quorum sensing inhibitors(QSIs),as new-typed antibiotics currently being used in the fields of aquaculture,sewage treatment,and crop disease control,have a wide application prospect.Since they are very likely to coexist with the traditional antibiotics in the environment,it is necessary to explore the joint effects of QSIs and the traditional antibiotics on bacterial resistance.Previous studies often use the unit method to explore the joint resistance effects of mixed antibiotics at a fixed concentration,but the unit method cannot evaluate the joint resistance risk in a wide range of the concentrations.In this study,the conjugative transfer of RP4 plasmid was used to characterize the spread of bacterial drug resistance,and the independent action model(IA)was applied to the discrimination of combined drug resistance,and with quinolones(QNs)as representatives of traditional antibiotics,the effects of QSIs and QNs on the combined effects of conjugative transfer of E.coli RP4 plasmids were investigated.As a result,the findings revealed that all the 15 groups of QSIs-QNs mixtures could induce the conjugative transfer effects of E.coli,and the maximum promoting rate of the mixture was in the range of 23.32％～73.07％;comparing the IA curve with the dose-effect curve of QSIs-QNs mixture of the E.coli conjugative transfer in terms of position-al relationship,it was found that the combined conjugative effects of QSIs-QNs on E.coli presented a concentration-depen-dent feature,i.e.,when the mixture promoted the conjugative transfer frequency of E.coli,the joint action mode would change from synergistic effects to antagonistic effects with a increase of concentration;and through the joint experiment of toxicity to E.coli with QSIs-QNs,it was speculated that the concentration-dependent joint conjugative effects of the tested mixed antibi-otics were closely related to its joint toxicity.Finally,it is expected that the achievements of the study could provide a refer-ence for exploring the environmental risk assessment of combined exposure of QSIs and traditional antibiotics in the future.
Keywords：quorum sensing inhibitorsquinolonebacterial resistanceconjugative transfercombined effects
Publication Date：2023-08-28
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：9( 108-116 )