Centre of Advanced Study in Marine Biology, Annamalai University, Parangipettai, Cuddalore, Tamil Nadu, 608 502, India.
PAR Life Sciences and Research Private Limited, Woraiyur, Trichy, Tamil Nadu, 620003, India.
World J Microbiol Biotechnol. 2022 Jun 27;38(8):146. doi: 10.1007/s11274-022-03335-z.
Quorum sensing (QS) is a potential target for inhibiting bacterial antibiotic resistance and associated pathogenicity. The present study aimed to investigate vaccenic acid anti-QS and antibiofilm potential against Chromobacterium violaceum and methicillin-resistant Staphylococcus aureus (MRSA). In the broth microdilution method, we determined the minimum inhibitory concentration (MIC) of vaccenic acid against C. violaceum and MRSA. Then, we determined the vaccenic acid anti-QS potential against C. violaceum via a violacein inhibition assay. Vaccenic acid at a sub-MIC concentration significantly inhibited violacein pigment production. Vaccenic acid also inhibits C. violaceum and MRSA biofilm formation at sub-MIC concentrations. The effect of vaccenic acid antivirulence potential was evaluated by phenotypic virulence assays. The results showed that vaccenic acid at a sub-MIC concentration significantly inhibited the virulence production of C. violaceum (chitinase and motility) and MRSA (hemolysin and staphyloxanthin production). Quantitative PCR analysis revealed the downregulation of QS associated genes upon vaccenic acid treatment. This resulted in the downregulation of genes involved in QS mechanisms such as cviI, cviR, and SarA and pigment production such as vioB and crtM. The results of the present study suggest that vaccenic acid is a promising agent to combat C. violaceum and MRSA.
群体感应 (QS) 是抑制细菌抗生素耐药性和相关致病性的潜在靶点。本研究旨在研究羊毛脂酸对 Chromobacterium violaceum 和耐甲氧西林金黄色葡萄球菌 (MRSA) 的抗 QS 和抗生物膜潜力。在肉汤微量稀释法中，我们测定了羊毛脂酸对 C. violaceum 和 MRSA 的最小抑菌浓度 (MIC)。然后，我们通过紫色素抑制试验测定了羊毛脂酸对 C. violaceum 的抗 QS 潜力。亚 MIC 浓度的羊毛脂酸显著抑制了紫色素的产生。羊毛脂酸还能抑制 C. violaceum 和 MRSA 在亚 MIC 浓度下的生物膜形成。通过表型毒力试验评估了羊毛脂酸抗病毒潜力的效果。结果表明，亚 MIC 浓度的羊毛脂酸显著抑制了 C. violaceum（几丁质酶和运动性）和 MRSA（溶血素和金黄色素产生）的毒力产生。定量 PCR 分析显示，羊毛脂酸处理后，与 QS 相关的基因下调。这导致与 QS 机制相关的基因（如 cviI、cviR 和 SarA）和色素产生相关的基因（如 vioB 和 crtM）下调。本研究结果表明，羊毛脂酸是一种有前途的对抗 C. violaceum 和 MRSA 的药物。
