中国兽医杂志2026，Vol.62Issue(8)：58-69,12.DOI:10.20157/j.cnki.zgsyzz.2026.sf.044
亚抑菌浓度下血根碱对IncX3型质粒接合转移的抑制作用及机制研究
Inhibitory Effect and Mechanism of Sanguinarine on the Conjugative Transfer of IncX3 Plasmid at Subinhibitory Concentrations
摘要
Abstract
To identify inhibitors of IncX3 plasmid conjugative transfer and investigate their mechanisms of action,an IncX3 plasmid conjugation model was established using Escherichia coli BW25113-IncX3 as the donor strain and MG1655 as the recipient strain,followed by high-throughput screening.The effects of candidate compounds were evaluated by calculating inhibition folds at sub-inhibitory concentrations,assessing bacterial growth,and validating their applicability in different recipient strain models.Furthermore,the mechanisms underlying the regulation of IncX3 plasmid conjugative transfer were investigated by measuring bacterial respiratory activity,the NAD⁺/NADH ratio,proton motive force,intracellular ATP content,cell membrane permeability,intracellular reactive oxygen species(ROS)levels,and gene expression using real-time fluorescence quantitative polymerase chain reaction(qPCR).The results showed that sanguinarine(SAN)was identified from a library of 1 191 natural compounds.Compared with the Control group,SAN at one-half of the minimum inhibitory concentration(1/2 MIC)had no significant effect on the growth of donor or recipient strains(P>0.05),but significantly inhibited the conjugative transfer efficiency of IncX3 plasmids in different recipient strains(MG1655 and EC600)(P<0.000 1).Mechanistic studies demonstrated that,compared with the Control group,treatment with 1/2 MIC SAN significantly reduced iodonitrotetrazolium chloride(INT)reduction capacity,the NAD ⁺/NADH ratio,transmembrane proton gradient(ΔpH),intracellular ATP content,and ROS levels in both donor and recipient strains(P<0.000 1).In contrast,cell membrane permeability in recipient strains was significantly increased(P<0.000 1).In addition,treatment with 1/2 MIC SAN significantly downregulated the mRNA expression levels of genes associated with the type Ⅳ secretion system and energy metabolism(P<0.01 or P<0.000 1).These results indicate that SAN inhibits the conjugative transfer of IncX3 plasmids at sub-inhibitory concentrations by suppressing electron transport in the bacterial respiratory chain,disrupting the proton motive force,reducing intracellular energy supply,and downregulating the expression of conjugation-related genes.关键词
血根碱(SAN)/IncX3型质粒/接合转移/能量代谢/Ⅳ型分泌系统Key words
sanguinarine(SAN)/IncX3 plasmid/conjugative transfer/energy metabolism/type Ⅳ secretion system分类
农业科技引用本文复制引用
田芸睿,王冬立,汪洋,邹之宇,宋黄威,蒋君瑶,孙达,谢宁,刘德俊,吴聪明,刘俊峰..亚抑菌浓度下血根碱对IncX3型质粒接合转移的抑制作用及机制研究[J].中国兽医杂志,2026,62(8):58-69,12.基金项目
国家自然科学基金青年科学基金项目(C类)(32503108) （C类）
拼多多-中国农业大学研究基金项目(PC2023A01002) （PC2023A01002）
