Laboratório de Química Biológica de Microrganismos, Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
Programa de Biologia Celular e Parasitologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
PLoS One. 2023 Feb 3;18(2):e0280964. doi: 10.1371/journal.pone.0280964. eCollection 2023.
Scedosporium and Lomentospora species are opportunistic filamentous fungi that cause localized and disseminated infections in immunocompetent and immunocompromised patients. These species are considered resistant fungi due to their low susceptibility to most current antifungal agents used in healthcare settings. The search for new compounds that could work as promising candidate antifungal drugs is an increasing field of interest. In this context, in the present study we screened the Pandemic Response Box® library (Medicines for Malaria Venture [MMV], Switzerland) to identify compounds with antifungal activity against Scedosporium and Lomentospora species. An initial screening of the drugs from this collection at 5 μM was performed using a clinical Scedosporium aurantiacum isolate according to the EUCAST protocol. Compounds with activity against this fungus were also tested against four other species (S. boydii¸ S. dehoogii, S. apiospermum and L. prolificans) at concentrations ranging from 0.078 to 10 μM. Seven compounds inhibited more than 80% of S. aurantiacum growth, three of them (alexidine, amorolfine and olorofim) were selected due to their differences in mechanism of action, especially when compared to drugs from the azole class. These compounds were more active against biofilm formation than against preformed biofilm in Scedosporium and Lomentospora species, except alexidine, which was able to decrease preformed biofilm about 50%. Analysis of the potential synergism of these compounds with voriconazole and caspofungin was performed by the checkerboard method for S. aurantiacum. The analysis by Bliss methodology revealed synergistic effects among selected drugs with caspofungin. When these drugs were combined with voriconazole, only alexidine and amorolfine showed a synergistic effect, whereas olorofim showed an antagonistic effect. Scanning electron microscopy revealed that alexidine induces morphology alterations in S. aurantiacum biofilm grown on a catheter surface. Reactive oxygen species production, mitochondrial activity and surface components were analyzed by fluorescent probes when S. aurantiacum was treated with selected drugs and revealed that some cell parameters are altered by these compounds. In conclusion, alexidine, amorolfine and olorofim were identified as promising compounds to be studied against scedosporiosis and lomentosporiosis.
枝顶孢属和石座盘属是机会性丝状真菌，可引起免疫功能正常和免疫功能低下患者的局部和播散性感染。由于对大多数当前在医疗保健环境中使用的抗真菌药物的敏感性低，这些物种被认为是具有抗药性的真菌。寻找新的化合物作为有前途的候选抗真菌药物是一个日益受到关注的领域。在这种情况下，在本研究中，我们筛选了大流行性疾病应对盒库®（瑞士医药疟疾 Venture [MMV]），以确定对枝顶孢属和石座盘属具有抗真菌活性的化合物。根据 EUCAST 方案，使用临床分离的枝顶孢属金黄色菌株对该药物库中的药物进行了 5 μM 的初步筛选。对这种真菌具有活性的化合物也在 0.078 至 10 μM 的浓度范围内对其他四种物种（ S. boydii¸ S. dehoogii，S. apiospermum 和 L. prolificans）进行了测试。七种化合物抑制了超过 80％的枝顶孢属金黄色生长，其中三种（阿立西定，阿莫罗芬和奥洛罗非姆）被选中，因为它们的作用机制不同，尤其是与唑类药物相比。这些化合物在枝顶孢属和石座盘属中对生物膜形成的抑制作用大于对已形成生物膜的抑制作用，而阿立西定则能够降低约 50％的已形成生物膜。通过棋盘法分析了这些化合物与伏立康唑和卡泊芬净联合应用的潜在协同作用，以研究枝顶孢属金黄色。通过 Bliss 方法学分析显示，所选药物与卡泊芬净之间存在协同作用。当将这些药物与伏立康唑联合使用时，只有阿立西定和阿莫罗芬显示出协同作用，而奥洛罗非姆显示出拮抗作用。扫描电子显微镜显示，阿立西定可诱导在导管表面生长的枝顶孢属金黄色生物膜的形态改变。当用选定的药物处理枝顶孢属金黄色时，通过荧光探针分析了活性氧物质的产生，线粒体活性和表面成分，结果表明这些化合物改变了某些细胞参数。总之，阿立西定，阿莫罗芬和奥洛罗非姆被确定为有前途的化合物，可用于研究枝孢菌病和石座盘菌病。
