IMBIV - CONICET, Córdoba, Argentina.
Departamento de Cs. Farmacéuticas, Fac. de Cs. Químicas, Univ. Nacional de Córdoba, Argentina.
Med Mycol. 2021 Mar 4;59(3):244-252. doi: 10.1093/mmy/myaa046.
As sessile cells of fungal biofilms are at least 500-fold more resistant to antifungal drugs than their planktonic counterparts, there is a requirement for new antifungal agents. Olygostyrylbenzenes (OSBs) are the first generation of poly(phenylene)vinylene dendrimers with a gram-positive antibacterial activity. Thus, this study aimed to investigate the antifungal activity of four OSBs (1, 2, 3, and 4) on planktonic cells and biofilms of Candida tropicalis. The minimum inhibitory concentration (MIC) for the planktonic population and the sessile minimum inhibitory concentrations (SMIC) were determined. Biofilm eradication was studied by crystal violet stain and light microscopy (LM), and confocal laser scanning microscopy (CLSM) was also utilized in conjunction with the image analysis software COMSTAT. Although all the OSBs studied had antifungal activity, the cationic OSBs were more effective than the anionic ones. A significant reduction of biofilms was observed at MIC and supraMIC50 (50 times higher than MIC) for compound 2, and at supraMIC50 with compound 3. Alterations in surface topography and the three-dimensional architecture of the biofilms were evident with LM and CLSM. The LM analysis revealed that the C. tropicalis strain produced a striking biofilm with oval blastospores, pseudohyphae, and true hyphae. CLSM images showed that a decrease occurred in the thickness of the mature biofilms treated with the OSBs at the most effective concentration for each one. The results obtained by microscopy were supported by those of the COMSTAT program. Our results revealed an antibiofilm activity, with compound 2 being a potential candidate for the treatment of C. tropicalis infections.
This study aimed to investigate the antifungal activity of four OSBs (1, 2, 3, and 4) on planktonic cells and biofilms of Candida tropicalis. Our results revealed an antibiofilm activity, with compound 2 being a potential candidate for the treatment of C. tropicalis infections.
由于真菌生物膜中的固着细胞对抗真菌药物的耐药性至少比浮游细胞高 500 倍，因此需要新的抗真菌药物。寡缩苯乙烯基苯（OSB）是第一代具有革兰氏阳性抗菌活性的聚（对苯撑乙烯）树状大分子。因此，本研究旨在研究四种 OSB（1、2、3 和 4）对热带假丝酵母浮游细胞和生物膜的抗真菌活性。测定了浮游细胞的最小抑菌浓度（MIC）和固着最小抑菌浓度（SMIC）。通过结晶紫染色和明场显微镜（LM）研究了生物膜的清除，并且还结合图像分析软件 COMSTAT 利用共聚焦激光扫描显微镜（CLSM）。尽管所有研究的 OSB 都具有抗真菌活性，但阳离子 OSB 比阴离子 OSB 更有效。在化合物 2 的 MIC 和超 MIC50（MIC 的 50 倍）以及化合物 3 的超 MIC50 下，观察到生物膜显著减少。LM 和 CLSM 显示出生物膜的表面形貌和三维结构发生了变化。LM 分析显示，热带假丝酵母菌株产生了一种引人注目的生物膜，其中含有椭圆形芽生孢子、假菌丝和真菌丝。CLSM 图像显示，在用 OSB 处理最有效浓度的情况下，生物膜的成熟度降低。显微镜结果得到了 COMSTAT 程序的支持。我们的结果显示出抗生物膜活性，化合物 2 是治疗热带假丝酵母感染的潜在候选药物。
