中国兽医杂志2024，Vol.60Issue(5)：78-85,8.DOI:10.20157/j.cnki.zgsyzz.2024.05.010
亚抑菌浓度万古霉素对质粒接合转移的促进作用
Promoting Effect of Sub-inhibitory Concentration of Vancomycin on Plasmid Conjugation Transfer
摘要
Abstract
To analyze the effect of sub-inhibitory concentration of vancomycin on plasmid conjugation transfer,this study established a conjugation transfer model using Escherichia coli(E.coli)J53 as the recipient strain,E.coli DH5α carrying RP4-7 plasmid and clinical strain E.coli LD67-1 carrying mcr-1 positive IncI2 plasmid as donor strains.The influence of sub-inhibitory concentration of vancomycin on conjugation transfer was determined,and the underlying mechanisms were explored through tests of cell membrane permeability,scanning electron microscopy observation,detection of reactive oxygen species(ROS),and real-time quantitative PCR(RT-qPCR).The results showed that compared with the blank control group,sub-inhibitory concentration of vancomycin significantly increased the conjugation transfer frequency of RP4-7 plasmid and mcr-1 positive IncI2 plasmid(P<0.05);N-phenyl-1-naphthylamine(NPN)and propidium iodide(PI)probe tests revealed that sub-inhibitory concentration of vancomycin increased the permeability of both the inner and outer membranes of recipient cells,as well as the outer membrane of donor cells;scanning electron microscopy observation demonstrated membrane damage in conjugative bacterial cells after treatment with 1/4 minimal inhibitory concentration(MIC)of vancomycin;ROS detection results showed that although the expression levels of ROS in recipient bacteria treated with 1/4 MIC of vancomycin were significantly upregulated compared with the blank control group(P<0.05),there were no significant changes in ROS levels in donor and recipient bacteria when treated with 1/8 MIC of vancomycin(P>0.05);RT-qPCR results showed that sub-inhibitory concentration of vancomycin significantly upregulated the mRNA expression levels of pore protein genes ompF and ompC in both donor and recipient bacteria(P<0.05),markedly upregulated the mRNA expression level of trbBp gene(which regulates the formation of"connecting bridge"between bacteria)(P<0.01),and significantly upregulated the mRNA expression levels of bacteria SOS response-related genes recA,recN,ruvA,and lexA(P<0.05).These results suggest that sub-inhibitory concentration of vancomycin may promote the conjugation transfer process of RP4-7 plasmid and mcr-1 positive IncI2 plasmid by increasing bacterial cell membrane permeability,triggering SOS response,and facilitating the formation of conjugative bridge.关键词
亚抑菌浓度/万古霉素/质粒接合转移/mcr-1Key words
sub-inhibitory concentration/vancomycin/plasmid conjugation transfer/mcr-1分类
农业科技引用本文复制引用
游祖姣,曾福鑫,王志强,肖霞..亚抑菌浓度万古霉素对质粒接合转移的促进作用[J].中国兽医杂志,2024,60(5):78-85,8.基金项目
国家自然科学基金项目(32273055) （32273055）
