Activity of MSI-78, h-Lf1-11 and cecropin B antimicrobial peptides alone and in combination with voriconazole and amphotericin B against clinical isolates of Fusarium solani

Laura Bedin Denardi, Carla Weiblen, Lara Baccarin Ianiski, Paula Cristina Stibbe, Janio Morais Santurio

Department of Microbiology and Parasitology, Federal University of Santa Maria (UFSM), Avenida Roraima, no 1000, Prédio 20, sala 4139, CEP 97105-900, Santa Maria, RS, Brazil.

Abstract

Fusarium infections have been associated with high mortality rates due to the lack of definition of an ideal treatment strategy. Antimicrobial peptides (AMPs) have potential antifungal activity. Therefore, investigating the in vitro activity of these molecules alone and in association with conventional antifungals against clinical isolates of Fusarium was the aim of this study. Fusarium solani (n = 10) strains were tested against the AMPs, MSI-78, h-Lf1-11 and cecropin B in accordance with CLSI protocol. Further, a checkerboard assay for its combination with amphotericin B or voriconazole, was carried out. MSI-78, h-Lf1-11 and cecropin B exhibited antifungal activity against F. solani strains tested with MICs ranging from 20 to 320 mg/L. Satisfactory percentage of synergism was demonstrated for all evaluated combinations, ranging from 70 to 100%. The use of AMPs combined with amphotericin B and voriconazole antifungals has great synergistic potential and deserve to be evaluated in murine models of fusariosis.

Keywords: Fusarium solani, Antimicrobial peptides, MSI-78, h-Lf1-11, Cecropin B.