Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
J Glob Antimicrob Resist. 2023 Dec;35:289-296. doi: 10.1016/j.jgar.2023.10.005. Epub 2023 Oct 14.
Antimicrobial resistance and biofilm formation are increasingly significant public health concerns. This study aimed to examine the antibacterial and antibiofilm properties of carbon dots (C-dots) alone and in combination with antibiotics against biofilm-forming isolates of Pseudomonas aeruginosa.
The antibacterial property of C-dots was investigated by broth microdilution method against ATCC PAO1 and P. aeruginosa clinical isolates. The antibacterial effect of the C-dots and ciprofloxacin combination was investigated using the checkerboard method. The antibiofilm effect of the C-dots alone and its combination with ciprofloxacin was evaluated using the microtiter plate method. Subsequently, the toxicity of each agent was tested on L929 fibroblast cells. In the end, the effects of C-dots on the expression levels of pslA, pelA, and ppyR genes were determined using real-time quantitative PCR.
The combination of C-dots and ciprofloxacin exhibited a synergistic effect. Additionally, this compound substantially decreased bacterial growth (P < 0.0001) and inhibited biofilm formation at MIC (96 µg/mL) and sub-MIC (48 µg/mL) concentrations (P < 0.0053, P < 0.01). After being exposed to C-dots at a concentration of 1mg/mL for 24 hours, the survival rate of L929 cells was 87.3%. The expression of genes pslA, pelA, and ppyR, associated with biofilm formation in P. aeruginosa, was significantly reduced upon exposure to C-dots (P < 0.0023).
The findings demonstrate a promising new treatment method for infections. Furthermore, reducing the dosage of antibiotics can lead to an improvement in the toxic effects caused by dose-dependent antibiotics and antimicrobial activity.
抗菌耐药性和生物膜形成是日益严重的公共卫生问题。本研究旨在检测碳点（C-dots）单独及与抗生素联合应用对铜绿假单胞菌生物膜形成分离株的抗菌和抗生物膜特性。
采用肉汤微量稀释法检测 C-dots 对 ATCC PAO1 和铜绿假单胞菌临床分离株的抗菌作用。采用棋盘法检测 C-dots 与环丙沙星联合应用的抗菌作用。采用微量滴定板法评价 C-dots 单独及其与环丙沙星联合应用的抗生物膜作用。随后，在 L929 成纤维细胞上测试每种药物的毒性。最后，采用实时定量 PCR 法测定 C-dots 对 pslA、pelA 和 ppyR 基因表达水平的影响。
C-dots 与环丙沙星联合应用具有协同作用。此外，该化合物在 MIC（96μg/mL）和亚 MIC（48μg/mL）浓度下显著降低了细菌生长（P<0.0001）并抑制了生物膜形成（P<0.0053，P<0.01）。在浓度为 1mg/mL 的 C-dots 孵育 24 小时后，L929 细胞的存活率为 87.3%。C-dots 暴露后，铜绿假单胞菌生物膜形成相关基因 pslA、pelA 和 ppyR 的表达显著降低（P<0.0023）。
研究结果表明，这是一种有前途的新治疗方法，可用于感染治疗。此外，减少抗生素剂量可以改善剂量依赖性抗生素和抗菌活性引起的毒性作用。
