Brazilian Team's Synthetic Peptide FK18 Kills Candida tropicalis Within Four Hours and Works Synergistically With Fluconazole in the Lab
Researchers at the Federal University of Mato Grosso do Sul in Brazil reported in Probiotics and Antimicrobial Proteins on October 24, 2026 that FK18, a rationally designed cationic peptide, inhibited Candida and Cryptococcus species at 5 to more than 40 µM, and at 10 µM eliminated Candida tropicalis cells within four hours. It rapidly permeabilized fungal membranes, its activity fell four-fold when extra ergosterol was added, and checkerboard tests showed strong synergy with the antifungal fluconazole. NMR showed FK18 forms a stable amphipathic helix in membrane-like environments; all results are from lab tests and simulations.