Wang Qi, Pan Lei, Han Ye, Zhou Zhijiang
School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300350, China.
Curr Microbiol. 2022 May 13;79(7):191. doi: 10.1007/s00284-022-02878-6.
Candida albicans is the most common fungal pathogen in hospital-acquired infections, which is extremely harmful to health. The increasing fungal infections is requiring the rapid development of novel antifungal agents. In this study, the antimicrobial activity of CHQS, an enterocin isolated from Enterococcus faecalis TG2 against C. albicans was confirmed by the minimum inhibitory concentration, minimum fungicidal concentration, and time-kill curve. Aniline blue and calcofluor white staining methods showed that CHQS remarkably affected β-1,3-glucan and chitin cell wall components and made cell wall more vulnerable. The C. albicans cell wall rupture and intracellular vacuolation were observed by TEM and SEM. Moreover, CHQS induced the accumulation of intracellular reactive oxygen species and decreased mitochondrial membrane potential. These results suggested that CHQS might have a complex multi-target antimicrobial mechanism against C. albicans. In addition, the use of CHQS combined with amphotericin B showed synergistic antimicrobial effects against C. albicans. In conclusion, enterocin CHQS, a natural product with antimicrobial effect, might has a bright future for the development of new antifungal drugs.
白色念珠菌是医院获得性感染中最常见的真菌病原体，对健康危害极大。日益增加的真菌感染需要新型抗真菌药物的快速发展。在本研究中，通过最低抑菌浓度、最低杀菌浓度和时间-杀菌曲线证实了从粪肠球菌TG2分离出的肠球菌素CHQS对白色念珠菌的抗菌活性。苯胺蓝和荧光增白剂染色方法表明，CHQS显著影响β-1,3-葡聚糖和几丁质细胞壁成分，使细胞壁更易受损。通过透射电子显微镜（TEM）和扫描电子显微镜（SEM）观察到白色念珠菌细胞壁破裂和细胞内空泡化。此外，CHQS诱导细胞内活性氧的积累并降低线粒体膜电位。这些结果表明，CHQS可能对白色念珠菌具有复杂的多靶点抗菌机制。此外，CHQS与两性霉素B联合使用对白色念珠菌显示出协同抗菌作用。总之，具有抗菌作用的天然产物肠球菌素CHQS在新型抗真菌药物开发方面可能具有光明的前景。
