Laboratory of Aquabiotics/Nanoscience, Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli, Tamil Nadu, 620024, India.
Central University of Tamil Nadu, Thiruvarur, Tamil Nadu, 610 005, India.
Arch Microbiol. 2024 Jun 26;206(7):326. doi: 10.1007/s00203-024-04034-z.
Aeromonas hydrophila poses significant health and economic challenges in aquaculture owing to its pathogenicity and prevalence. Overuse of antibiotics has led to multidrug resistance and environmental pollution, necessitating alternative strategies. This study investigated the antibacterial and antibiofilm potentials of quercetin against A. hydrophila. Efficacy was assessed using various assays, including antibacterial activity, biofilm inhibition, specific growth time, hemolysis inhibition, autoaggregation, and microscopic evaluation. Additionally, docking analysis was performed to explore potential interactions between quercetin and virulence proteins of A. hydrophila, including proaerolysin, chaperone needle-subunit complex of the type III secretion system, and alpha-pore forming toxin (PDB ID: 1PRE, 2Q1K, 6GRK). Quercetin exhibited potent antibacterial activity with 21.1 ± 1.1 mm zone of inhibition at 1.5 mg mL. It also demonstrated significant antibiofilm activity, reducing biofilm formation by 46.3 ± 1.3% at the MIC and attenuating autoaggregation by 55.9 ± 1.5%. Hemolysis was inhibited by 41 ± 1.8%. Microscopic analysis revealed the disintegration of the A. hydrophila biofilm matrix. Docking studies indicated active hydrogen bond interactions between quercetin and the targeted virulence proteins with the binding energy -3.2, -5.6, and -5.1 kcal mol⁻1, respectively. These results suggest that quercetin is an excellent alternative to antibiotics for combating A. hydrophila infection in aquaculture. The multifaceted efficacy of quercetin in inhibiting bacterial growth, biofilm formation, virulence factors, and autoaggregation highlights the potential for aquaculture health and sustainability. Future research should delve into the precise mechanisms of action and explore synergistic combinations with other compounds for enhanced efficacy and targeted interventions.
嗜水气单胞菌因其致病性和普遍性，给水产养殖带来了重大的健康和经济挑战。抗生素的过度使用导致了多药耐药性和环境污染，因此需要替代策略。本研究调查了槲皮素对嗜水气单胞菌的抗菌和抗生物膜潜力。使用各种测定法评估了功效，包括抗菌活性、生物膜抑制、特定生长时间、溶血抑制、自动聚集和显微镜评估。此外，还进行了对接分析，以探索槲皮素与嗜水气单胞菌毒力蛋白（PDB ID：1PRE、2Q1K、6GRK）之间的潜在相互作用，包括aerolysin、III 型分泌系统伴侣针状亚基复合物和 alpha-孔形成毒素。槲皮素在 1.5 mg mL 时表现出强烈的抗菌活性，抑菌圈为 21.1 ± 1.1 mm。它还表现出显著的抗生物膜活性，在 MIC 下将生物膜形成减少 46.3 ± 1.3%，并将自动聚集减少 55.9 ± 1.5%。溶血抑制率为 41 ± 1.8%。显微镜分析显示嗜水气单胞菌生物膜基质的崩解。对接研究表明，槲皮素与靶标毒力蛋白之间存在活跃的氢键相互作用，结合能分别为-3.2、-5.6 和-5.1 kcal mol⁻1。这些结果表明，槲皮素是水产养殖中对抗嗜水气单胞菌感染的抗生素的绝佳替代品。槲皮素在抑制细菌生长、生物膜形成、毒力因子和自动聚集方面的多方面功效突出了水产养殖健康和可持续性的潜力。未来的研究应深入探讨其确切的作用机制，并探索与其他化合物的协同组合，以提高功效和进行靶向干预。
