Laboratório de Genética de Microrganismos, Departamento de Biologia Molecular, Universidade Federal da Paraíba, 58059-900, João Pessoa, PB, Brazil.
Universidade Federal da Paraíba, Instituto de Pesquisa em Fármacos e Medicamentos, João Pessoa, PB, 58059-900, Brazil.
Microb Pathog. 2020 Apr;141:104034. doi: 10.1016/j.micpath.2020.104034. Epub 2020 Jan 30.
Efflux pumps are integral parts of the bacterial plasma membrane that are responsible for many cases of antibiotic resistance. Modulators of drug resistance are regarded as the most suitable new antibacterial therapies. We evaluated the extracts of Sargassum polyceratium and the isolated compound pheophytin (Sp-1) for antibiotic modifying activity in strains of Staphylococcus aureus with efflux pump. The minimum inhibitory concentrations (MICs) for norfloxacin, tetracycline and erythromycin were determined by the microdilution broth method, in the absence and presence of the extract at a sub-inhibitory concentration (MIC/4). The extracts and isolated compounds showed no significant antimicrobial activity, but they changed the antibiotic activity, decreasing bacterial resistance by 2 to 4x. Using a checkerboard method, it was also possible to observe the synergistic effect (ΣFIC ≤ 0.5) between Sp-1 and the antibiotics erythromycin and norfloxacin. The results indicate that the seaweed Sargassum polyceratium and pheophytin are potential sources of an antibiotic adjuvant that modulates bacterial resistance, acting as a putative efflux pump inhibitor.
外排泵是细菌质膜的组成部分，负责许多抗生素耐药的情况。耐药调节剂被认为是最适合的新型抗菌治疗方法。我们评估了马尾藻和分离化合物叶啉（Sp-1）对具有外排泵的金黄色葡萄球菌菌株的抗生素修饰活性的提取物。通过微量稀释肉汤法，在亚抑菌浓度（MIC/4）下不存在和存在提取物的情况下，确定了诺氟沙星、四环素和红霉素的最小抑菌浓度（MICs）。提取物和分离化合物没有显示出明显的抗菌活性，但它们改变了抗生素的活性，使细菌的耐药性降低了 2 到 4 倍。使用棋盘法，还可以观察到 Sp-1 与抗生素红霉素和诺氟沙星之间的协同作用（ΣFIC ≤ 0.5）。结果表明，海藻马尾藻和叶啉是调节细菌耐药性的抗生素佐剂的潜在来源，它们可能作为外排泵抑制剂发挥作用。
