Antifungal activity and mechanism of novel peptide antimicrobial peptide (GmAMP) against fluconazole-resistant .

BACKGROUND

There is a pressing need to create innovative alternative treatment approaches considering the overuse of antifungal drugs causes the number of clinically isolated fluconazole-resistant species to increase. antimicrobial peptide (GmAMP) is a novel peptide screened by us using artificial intelligence modeling techniques, and pre-tests showed its strong antimicrobial activity against clinically fluconazole-resistant .

METHODS

The study aimed to comprehensively investigate the antimicrobial activity and mechanisms of GmAMP against fluconazole-resistant . The antifungal activity of GmAMP against fluconazole-resistant was assessed by using broth microdilution method, growth and fungicidal kinetics, hypha transformation, and antibiofilm assay. To further uncover the potential mechanisms of action of GmAMP, we performed scanning electron microscopy, flow cytometry, cell membrane potential probe 3, 3'-Dipropylthiadicarbocyanine Iodide (DiSC(5)), and reactive oxygen species (ROS) probe 2', 7'-Dichlorodihydrofluorescein diacetate (DCFH-DA) detection to assess the cellular morphology and structure, membrane permeability, membrane depolarization, and ROS accumulation, respectively. At the same time, we used cytotoxicity and degree of erythrocyte hemolysis assays to assess GmAMP's toxicity . Cytotoxicity and treatment efficacy were evaluated by utilizing the larvae infection model.

RESULTS

GmAMP exhibited significant antifungal activity against fluconazole-resistant with a minimum inhibitory concentration (MIC) of 25 µM and demonstrated fungicidal effects at 100 µM within 2 h. GmAMP prevented the transition from yeast to hypha morphology, inhibited the biofilm formation rate of 88.32%, and eradicated the mature biofilm rate of 58.28%. Additionally, GmAMP treatment at 100 µM caused cell structure damage in fluconazole-resistant , whereas GmAMP treatment at concentrations ranging from 25 to 100 µM caused membrane permeability, depolarization of cell membrane potential, and intracellular ROS accumulation. Moreover, GmAMP enhanced the survival rate of 75% for with fluconazole-resistant infection as well as reduced fungal burden by approximately 1.0 × 10 colony forming units per larva (CFU per larva).

CONCLUSION

GmAMP can disrupt the cell membrane of fluconazole-resistant and also shows favorable safety and therapeutic efficacy . Accordingly, GmAMP has the potential to be an agent against drug-resistant fungi.