In vitro antifungal activity of pelgipeptins against human pathogenic fungi and Candida albicans biofilms

Débora Luíza Albano Fulgêncio; Rosiane Andrade da Costa; Fernanda Guilhelmelli; Calliandra Maria de Souza Silva; Daniel Barros Ortega; Thiago Fellipe de Araujo; Philippe Spezia Silva; Ildinete Silva-Pereira; Patrícia Albuquerque; Cristine Chaves Barreto

doi:10.3934/microbiol.2021003

In vitro antifungal activity of pelgipeptins against human pathogenic fungi and Candida albicans biofilms

AIMS Microbiol. 2021 Jan 19;7(1):28-39. doi: 10.3934/microbiol.2021003. eCollection 2021.

Affiliations

¹ Graduate Program in Genomic Sciences and Biotechnology, Catholic University of Brasília, Brasília, Brazil.
² Laboratory of Molecular Biology, Department of Cellular Biology, Institute of Biological Sciences, University of Brasília, Brasília, Brazil.
³ Faculty of Ceilandia, University of Brasília, Brasília, Brazil.

Abstract

Systemic mycoses have become a major cause of morbidity and mortality, particularly among immunocompromised hosts and long-term hospitalized patients. Conventional antifungal agents are limited because of not only their costs and toxicity but also the rise of resistant strains. Lipopeptides from Paenibacillus species exhibit antimicrobial activity against a wide range of human and plant bacterial pathogens. However, the antifungal potential of these compounds against important human pathogens has not yet been fully evaluated, except for Candida albicans. Paenibacillus elgii produces a family of lipopeptides named pelgipeptins, which are synthesized by a non-ribosomal pathway, such as polymyxin. The present study aimed to evaluate the activity of pelgipeptins produced by P. elgii AC13 against Cryptococcus neoformans, Paracoccidioides brasiliensis, and Candida spp. Pelgipeptins were purified from P. elgii AC13 cultures and characterized by high-performance liquid chromatography (HPLC) and mass spectrometry (MALDI-TOF MS). The in vitro antifugal activity of pelgipeptins was evaluated against C. neoformans H99, P. brasiliensis PB18, C. albicans SC 5314, Candida glabrata ATCC 90030, and C. albicans biofilms. Furthermore, the minimal inhibitory concentration (MIC) was determined according to the CLSI microdilution method. Fluconazole and amphotericin B were also used as a positive control. Pelgipeptins A to D inhibited the formation and development of C. albicans biofilms and presented activity against all tested microorganisms. The minimum inhibitory concentration values ranged from 4 to 64 µg/mL, which are in the same range as fluconazole MICs. These results highlight the potential of pelgipeptins not only as antimicrobials against pathogenic fungi that cause systemic mycoses but also as coating agents to prevent biofilm formation on medical devices.

Keywords: Candida spp; Cryptococcus neoformans; Paenibacillus elgii; Paracoccidioides brasiliensis; lipopeptides; systemic mycosis.