Department of Food Engineering, College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, P. R. China.
Frontiers Science Center for Disease-related Molecular Network, Institutes for Systems Genetics, West China Hospital, Sichuan University, 88 Keyuan South Road, Hi-Tech Zone, Chengdu 610041, P. R. China.
J Agric Food Chem. 2021 Mar 24;69(11):3496-3510. doi: 10.1021/acs.jafc.0c07826. Epub 2021 Mar 16.
is a Gram-positive endospore-forming foodborne pathogen that causes lethal food poisoning and significant economic losses, usually through biofilm- and endospore-induced recurrent cross- and postprocessing contamination. Due to the lack of critical inhibitory targets and control strategies, biofilm contamination is a problem that urgently needs a solution. In this study, the antibacterial and antibiofilm activities of several natural potential bacterial quorum sensing (QS) interferers, a group of spice-originated monoterpenoids, were screened, and terpinen-4-ol effectively inhibited growth and biofilm and spore germination with minimum growth inhibition and 50% biofilm inhibitory concentrations of 8 and 2 μmol/mL, respectively. FESEM/CLSM and phenotypic research illustrated that in addition to a decrease in the number of attached cells, (+)-terpinen-4-ol also obviously reduced extracellular matrix synthesis, especially exopolysaccharides, and inhibited the swarming motility and protease activity of . (+)-Terpinen-4-ol did not exert a significant effect on AI-2 signals in . Accordingly, the -produced interspecies QS signals diffusing signal factors (DSFs, C8-C15) and diketopiperazines (DKPs) were detected and identified here, which suppressed biofilm formation in a concentration-dependent manner. (+)-Terpinen-4-ol significantly increased the levels of specific DSF and DKP signals in and down-regulated the gene expression of some homologues in transcription level. Moreover, both DKPs and DSFs inhibited swarming motility and protease activity in , while just the DSF signals 2-dodecenoic acid and 11-methyl-2-dodecenoic acid inhibited exopolysaccharide synthesis like (+)-terpinen-4-ol. In summary, strains were found to produce nine DSF- and six DKP-type QS signaling molecules, which repressed biofilm formation. (+)-Terpinen-4-ol was confirmed to be a promising antibacterial and antibiofilm agent against upregulating DSFs and DKPs levels, and it could target the critical genes for DSFs turnover.
是一种革兰氏阳性产芽孢的食源性致病菌，可引起致命的食物中毒，并造成重大的经济损失，通常是通过生物膜和芽孢诱导的反复交叉和后处理污染造成的。由于缺乏关键的抑制靶点和控制策略，生物膜污染是一个亟待解决的问题。在这项研究中，筛选了几种天然潜在的细菌群体感应（QS）干扰物（一组源自香料的单萜）的抗菌和抗生物膜活性，萜品-4-醇有效地抑制了生长和生物膜，其最小生长抑制浓度和 50%生物膜抑制浓度分别为 8 和 2 μmol/mL。FESEM/CLSM 和表型研究表明，除了附着细胞数量减少外，（+）-萜品-4-醇还明显减少了细胞外基质的合成，特别是胞外多糖，并抑制了运动和蛋白酶活性。（+）-萜品-4-醇对 中 AI-2 信号没有显著影响。因此，在这里检测并鉴定了产生的种间 QS 信号扩散信号因子（DSFs，C8-C15）和二酮哌嗪（DKPs），它们以浓度依赖的方式抑制生物膜的形成。（+）-萜品-4-醇显著增加了 中特定 DSF 和 DKP 信号的水平，并在转录水平下调了一些 同源物的基因表达。此外，DKPs 和 DSFs 都抑制了 中的泳动运动和蛋白酶活性，而只有 DSF 信号 2-十二烯酸和 11-甲基-2-十二烯酸像（+）-萜品-4-醇一样抑制胞外多糖的合成。总之，发现 株产生九种 DSF 和六种 DKP 型 QS 信号分子，抑制生物膜形成。（+）-萜品-4-醇被证实是一种有前途的抗生物膜剂，可上调 DSFs 和 DKPs 水平，针对关键基因进行 DSFs 循环。
