National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou, China.
Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou, P. R. China.
J Appl Microbiol. 2021 Jun;130(6):1893-1901. doi: 10.1111/jam.14885. Epub 2020 Nov 9.
The aim of this study was to determine the effects of unsaturated fatty acids on clinical plasmids.
Two unsaturated fatty acids, linoleic acid (LA) and α-linolenic acid (ALA) at final concentration 0, 0·03, 0·3 and 3 mmol l , respectively, were used to assess the effects on conjugative transfer of a mcr-1-harbouring plasmid pCSZ4 (IncX4) in conjugation experiment. The inhibitory mechanisms were analysed by molecular docking and the gene expression of virB11 was quantitated by qRT-PCR. Target plasmid diversity was carried out by TrwD/VirB11 homology protein sequence prediction analysis. Our results showed that LA and ALA inhibit plasmid pCSZ4 transfer by binding to the amino acid residues (Phe124 and Thr125) of VirB11 with dose-dependent effects. The expression levels of virB11 gene were also significantly inhibited by LA and ALA treatment. Protein homology analysis revealed a wide distribution of TrwD/VirB11-like genes among over 37 classes of plasmids originated from both Gram-negative and Gram-positive bacteria.
This study demonstrates representing a diversity of plasmids that may be potentially inhibited by unsaturated fatty acids.
Our work reported here provides additional support for application of curbing the spread of multiple plasmids by unsaturated fatty acids.
本研究旨在确定不饱和脂肪酸对临床质粒的影响。
分别使用两种不饱和脂肪酸亚油酸（LA）和α-亚麻酸（ALA），终浓度分别为 0、0.03、0.3 和 3mmol/L，评估其对携带 mcr-1 基因的质粒 pCSZ4（IncX4）在接合实验中进行共轭转移的影响。通过分子对接分析抑制机制，并通过 qRT-PCR 定量测定 virB11 的基因表达。通过 TrwD/VirB11 同源蛋白序列预测分析进行靶质粒多样性研究。结果表明，LA 和 ALA 通过与 VirB11 的氨基酸残基（Phe124 和 Thr125）结合，以剂量依赖性方式抑制质粒 pCSZ4 的转移。LA 和 ALA 处理还显著抑制了 virB11 基因的表达水平。蛋白质同源性分析表明，TrwD/VirB11 样基因广泛分布于革兰氏阴性和革兰氏阳性细菌来源的 37 类以上的质粒中。
本研究表明，不饱和脂肪酸可能会抑制多种质粒的传播，这代表了一种多样性。
我们在此报告的工作为应用不饱和脂肪酸抑制多种质粒的传播提供了额外的支持。
