Antibiofilm activity of manogepix, ibrexafungerp, amphotericin B, rezafungin, and caspofungin against spp. biofilms of reference and clinical strains.

This study comprehensively assessed the activity of manogepix (MNGX), ibrexafungerp (IBF), amphotericin B (AMB), rezafungin (RZF), and caspofungin (CAS) against planktonic cells and mature biofilms of spp.-reference and clinical strains using the Calgary biofilm device. Mature-phase biofilms of , ), and were exposed to a range of drug concentrations (0.12-128 µg/mL). Minimum Inhibitory Concentration (MIC) values for planktonic cells were ≤2 µg/mL for all strains; however, biofilm-associated MICs, minimum biocidal concentration (MBC), minimum biofilm eradication (MBEC), and minimum biofilm damaging concentration (MBDC) were significantly higher (2-4,119 times). Geometric mean (GM) of MBEC values indicated that MNGX had the highest antifungal activity within species, with a GM-MBEC of 5.9 µg/mL. Despite its overall potency, MNGX was less effective against biofilms from clade IV strains, where IBF showed superior activity. While not the most potent agent overall, AMB induced the smallest fold-change increases (2- to 32-fold) in biofilm-associated states data compared to planktonic MICs. Conversely, CAS exhibited the lowest activity against spp. biofilms. The eradication of and biofilms required substantially higher concentrations than , with some agents, such as RZF and CAS, necessitating up to 42-fold increases in dosage. In conclusion, our model highlights the antibiofilm activity of novel antifungals against major species, revealing significant differences in efficacy among species. MNGX demonstrated the highest activity, underscoring its potential as a promising candidate for the treatment of biofilm-related infections.