Raikwar Geetanjali, Mohan Sumedha, Dahiya Praveen
Amity Institute of Biotechnology, Amity University Uttar Pradesh, Sector-125, Noida, Uttar Pradesh, 201313, India.
Braz J Microbiol. 2025 Jun;56(2):1017-1031. doi: 10.1007/s42770-024-01567-9. Epub 2025 Jan 30.
Methicillin-resistant Staphylococcus aureus (MRSA) is one of the leading causes of infection worldwide due to its antimicrobial resistance. Plant-derived essential oils (EOs) have undergone extensive observational and clinical research to explore their antimicrobial properties. The present study aimed to check mec A positive MRSA isolates using sequencing analysis, determination of chemical composition using gas chromatography-mass spectroscopy (GC-MS), antioxidant, and antimicrobial activity of Anethum graveolens and Piper betle EOs against the infectious agent MRSA. The result demonstrates a significant antibacterial activity of both essential oils against MRSA clinical isolates. GC-MS analysis of Piper betle showed (41.06%) 3-Allyl-6-methoxyphenol (Eugenol) as the major compound, whereas Anethum graveolens exhibited o-cymene (14.01%) abundantly. Piper betle essential oil retained appreciable levels of total phenolic (39.5 ± 10.9 mg/g of gallic acid equivalents) and flavonoid content (216 ± 145 mg quercetin equivalent/g), when compared to Anethum graveolens essential oil. A strong correlation was observed between antioxidant activity (DPPH, FRAP, and ABTS), total phenolic, and total flavonoid content in the Piper betle and displayed using principal component analysis (PCA) and a scatter matrix plot. Parallelly, clear morphological bacterial alterations were visualized by scanning electron microscopy after treating it with essential oils. MRSA showed malformed cell surfaces or broken cells with pore formation and septae. These findings imply that both essential oils are potential natural sources of antimicrobials against the MRSA superbug. They can also be used in combination therapies with other plant EOs or with traditional antibiotics to combat the rise of bacteria resistance.
耐甲氧西林金黄色葡萄球菌（MRSA）由于其抗菌耐药性，是全球感染的主要原因之一。植物源精油（EOs）已进行了广泛的观察性和临床研究，以探索其抗菌特性。本研究旨在通过测序分析检测mec A阳性MRSA分离株，使用气相色谱-质谱联用仪（GC-MS）测定化学成分，以及测定莳萝和蒌叶精油对感染因子MRSA的抗氧化和抗菌活性。结果表明，两种精油对MRSA临床分离株均具有显著的抗菌活性。蒌叶的GC-MS分析显示，主要化合物为（41.06%）3-烯丙基-6-甲氧基苯酚（丁香酚），而莳萝中大量存在邻伞花烃（14.01%）。与莳萝精油相比，蒌叶精油保留了相当水平的总酚含量（39.5±10.9毫克/克没食子酸当量）和类黄酮含量（216±145毫克槲皮素当量/克）。在蒌叶中观察到抗氧化活性（DPPH、FRAP和ABTS）、总酚和总黄酮含量之间存在强相关性，并使用主成分分析（PCA）和散点矩阵图进行展示。同时，用精油处理后，通过扫描电子显微镜可以看到明显的细菌形态变化。MRSA显示出细胞表面畸形或细胞破裂，伴有孔隙形成和隔膜。这些发现表明，两种精油都是对抗MRSA超级细菌的潜在天然抗菌来源。它们还可与其他植物精油或传统抗生素联合用于治疗，以对抗细菌耐药性的上升。
