Navarro Miguel Octavio Pérez, Dilarri Guilherme, Simionato Ane Stefano, Grzegorczyk Kathlen, Dealis Mickely Liuti, Cano Barbara Gionco, Barazetti André Riedi, Afonso Leandro, Chryssafidis Andreas Lazaros, Ferreira Henrique, Andrade Galdino
Microbial Ecology Laboratory, Department of Microbiology, Universidade Estadual de Londrina, Londrina, Brazil.
Department of Biochemistry and Microbiology, Institute of Biosciences, Universidade Estadual Paulista, Rio Claro, Brazil.
Front Microbiol. 2020 Jun 4;11:1076. doi: 10.3389/fmicb.2020.01076. eCollection 2020.
The antibiotic activity of metalloantibiotic compounds has been evaluated since the 90s, and many different modes of action were characterized. In the last decade, the effects of secondary metabolites produced by LV strain, including a cupric compound identified as Fluopsin C, were tested against many pathogenic bacteria strains, proving their high antibiotic activity. In the present study, the bactericidal mechanisms of action of Fluopsin C and the semi-purified fraction F4A were elucidated. The results found in electron microscopy [scanning electron microscopy (SEM) and transmission electronic microscopy (TEM)] demonstrated that both Fluopsin C and F4A are affecting the cytoplasmatic membrane of Gram-positive and Gram-negative bacteria. These results were confirmed by fluorescence microscopy, where these bacteria presented permeabilization of their cytoplasmatic membranes after contact with the semi-purified fraction and pure compound. Using electronic and fluorescence microscopy, along with bacterial mutant strains with marked divisional septum, the membrane was defined as the primary target of Fluopsin C in the tested bacteria.
自20世纪90年代以来，人们一直在评估金属抗生素化合物的抗菌活性，并对许多不同的作用模式进行了表征。在过去十年中，对LV菌株产生的次级代谢产物的作用进行了测试，其中包括一种被鉴定为氟视蛋白C的铜化合物，该产物对许多病原菌菌株均有抗菌活性。在本研究中，阐明了氟视蛋白C和半纯化组分F4A的杀菌作用机制。电子显微镜（扫描电子显微镜和透射电子显微镜）观察结果表明，氟视蛋白C和F4A均会影响革兰氏阳性菌和革兰氏阴性菌的细胞质膜。荧光显微镜观察结果证实了这一点，在与半纯化组分和纯化合物接触后，这些细菌的细胞质膜出现了通透性。通过电子显微镜和荧光显微镜，以及带有明显分裂隔膜的细菌突变株，确定膜是氟视蛋白C在受试细菌中的主要作用靶点。
