Biofilm-related infections are a matter of concern especially because of the poor susceptibility of microorganisms to conventional antimicrobial agents. Innovative approaches are needed. The antibiofilm activity of extracts of cyanobacteria Arthrospira platensis, rich in free fatty acids, as well as of extract-loaded copper alginate-based nanocarriers, were studied on single- and dual-species biofilms of Candida albicans and Cutibacterium acnes. Their ability to inhibit the biofilm formation and to eradicate 24 h old biofilms was investigated. Concentrations of each species were evaluated using flow cytometry. Extracts prevented the growth of C. acnes single-species biofilms (inhibition > 75% at 0.2 mg/mL) but failed to inhibit preformed biofilms. Nanovectorised extracts reduced the growth of single-species C. albicans biofilms (inhibition > 43% at 0.2 mg/mL) while free extracts were weakly or not active. Nanovectorised extracts also inhibited preformed C. albicans biofilms by 55% to 77%, whereas the corresponding free extracts were not active. In conclusion, even if the studied nanocarrier systems displayed promising activity, especially against C. albicans, their efficacy against dual-species biofilms was limited. This study highlighted that working in such polymicrobial conditions can give a more objective view of the relevance of antibiofilm strategies by taking into account interspecies interactions that can offer additional protection to microbes.

中文翻译：

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纳米矢量化微藻提取物对抗白色念珠菌和痤疮皮肤杆菌生物膜：双物种条件的影响。


生物膜相关感染是一个值得关注的问题，特别是因为微生物对传统抗菌剂的敏感性较差。需要创新的方法。研究了富含游离脂肪酸的蓝藻节旋藻提取物以及负载提取物的海藻酸铜纳米载体的抗菌膜活性，对白色念珠菌和痤疮皮肤杆菌的单种和双种生物膜进行了研究。研究了它们抑制生物膜形成和消除 24 小时生物膜的能力。使用流式细胞术评估每个物种的浓度。提取物可防止痤疮丙酸杆菌单一物种生物膜的生长（0.2 mg/mL 时抑制率 > 75%），但无法抑制预先形成的生物膜。纳米载体化提取物减少了单一物种白色念珠菌生物膜的生长（0.2 mg/mL 时抑制> 43%），而游离提取物活性较弱或无活性。纳米载体化提取物还可以将预先形成的白色念珠菌生物膜抑制 55% 至 77%，而相应的游离提取物则没有活性。总之，即使所研究的纳米载体系统显示出有希望的活性，特别是针对白色念珠菌，它们针对双物种生物膜的功效也是有限的。这项研究强调，在这种多微生物条件下工作可以通过考虑可以为微生物提供额外保护的种间相互作用来更客观地了解抗菌膜策略的相关性。