Pathogenic strains of Staphylococcus aureus can cause several diseases including septicemia and endocarditis, in spite of being a commensal species of the human microbiota. The current drug resistance of S. aureus raises the need for new antimicrobials, and natural products represent a feasible source for prospection of such compounds, due to features including the diversity of structures and mechanisms of action. Here, we provide evidence of the antimicrobial activity of methanolic of Psidium guajava and Passiflora edulis pulps against planktonic cells and biofilms of clinical isolates of S. aureus. The extracts were effective against the strains in concentrations up to 7.81 and 250 μg/mL for planktonic cells and biofilms, respectively. Antagonistic interactions of the extracts to antimicrobial drugs were observed. The pulps caused no cytotoxic effects on BGM cells. GC-MS analysis found relevant molecules, and UPLC analysis suggested the presence of flavonoids. To the best of our knowledge, this is the first antibiofilm evidence of such extracts. The extracts seem to be safe and effective enough for more studies aiming at exploring isolated antimicrobial molecules using in vivo models for the treatment of staphylococcal diseases.

中文翻译：

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番石榴和西番莲果肉提取物对金黄色葡萄球菌，细胞毒性以及对抗菌药物活性的干扰的潜在生物膜作用

尽管金黄色葡萄球菌是人类微生物群的共生物种，但其致病性菌株仍可引起多种疾病，包括败血病和心内膜炎。当前的金黄色葡萄球菌的耐药性引起了对新抗微生物剂的需求，并且由于包括结构和作用机理的多样性在内的天然产物，天然产物代表了寻找此类化合物的可行来源。在这里，我们提供了番石榴（Psidium guajava）和西番莲（Passiflora edulis）果肉的甲醇对浮游生物细胞和金黄色葡萄球菌临床分离物生物膜的抗菌活性的证据。对于浮游细胞和生物膜，提取物分别对浓度高达7.81和250μg/ mL的菌株有效。观察到提取物与抗菌药物的拮抗作用。牙髓对BGM细胞没有细胞毒性作用。GC-MS分析发现相关分子，UPLC分析表明存在类黄酮。据我们所知，这是此类提取物的第一个抗生物膜证据。这些提取物似乎足够安全有效，可以用于更多的研究，目的是使用体内模型治疗葡萄球菌疾病来探索分离的抗菌分子。