Youssef Hadeer, Azmy Ahmed F, Eid Hussein M, Sayed Ossama M, Eldomany Ehab B, Farghali Ahmed A, Molham Fatma
Biotechnology and Life Sciences Department, Faculty of Postgraduate Studies for Advanced Sciences (PSAS), Beni-Suef University, Beni-Suef, Egypt.
Microbiology and Immunology Department, Faculty of Pharmacy, Beni-Suef University, Beni-Suef, 62514, Egypt.
Int Microbiol. 2025 Feb;28(2):227-239. doi: 10.1007/s10123-024-00534-6. Epub 2024 May 22.
In our study, the secretome of the clinical isolate Enterococcus faecalis HY7 displayed antibacterial activity against the vancomycin-resistant Enterococcus faecalis V853. These bacteriocin-like substances showed thermal stability at a wide range of temperatures up to 121 °C, while proteinase K treatment resulted in a total loss of their activity. PCR-based screening for bacteriocin biosynthetic genes revealed that Enterococcus faecalis HY7 harbored multiple enterocin-producing genes, including ent A, avc A, and as-48. The production kinetics demonstrated the highest levels of bacteriocins production at 16 h, whereas the activity was diminished after 32 h of microbial growth. Notably, the partially purified bacteriocins exhibited anti-proliferative activity on the colon cancer cells, Caco2, with an IC50 value of 172.8 μg/mL. Remarkably, the nanoencapsulation of our bacteriocins in liposome showed a fourfold increase in its anti-vancomycin-resistant Enterococcus activity, which is the first report of liposome encapsulation with anti-vancomycin resistant Enterococcus bacteriocin.
在我们的研究中，临床分离株粪肠球菌HY7的分泌蛋白组对耐万古霉素粪肠球菌V853显示出抗菌活性。这些类细菌素物质在高达121℃的广泛温度范围内表现出热稳定性，而蛋白酶K处理导致其活性完全丧失。基于PCR的细菌素生物合成基因筛选显示，粪肠球菌HY7含有多个产肠球菌素基因，包括ent A、avc A和as-48。生产动力学表明，在16小时时细菌素产量最高，而在微生物生长32小时后活性降低。值得注意的是，部分纯化的细菌素对结肠癌细胞Caco2表现出抗增殖活性，IC50值为172.8μg/mL。值得注意的是，我们的细菌素在脂质体中的纳米包封显示其抗耐万古霉素肠球菌活性增加了四倍，这是脂质体包封抗耐万古霉素肠球菌细菌素的首次报道。
