Proteome analysis of biofilm produced by a Fusarium falciforme keratitis infectious agent

• Published in: Microbial pathogenesis Vol. 130; pp. 232 - 241
• Main Authors: Calvillo-Medina, Rosa Paulina, Reyes-Grajeda, Juan Pablo, Barba-Escoto, Luis, Bautista-Hernandez, Luis Antonio, Campos-Guillén, Juan, Jones, George H., Bautista-de Lucio, Victor Manuel
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-05-2019
• Subjects: 2-DE-Gel electrophoresis; Biofilm; Fusarium falciforme; Keratomycosis; Multi-functional proteins; Fusarium falciforme; Biofilm; Keratomycosis; 2-DE-Gel electrophoresis; Multi-functional proteins
• ISSN: 0882-4010; 1096-1208
• DOI: 10.1016/j.micpath.2019.03.001

Biofilms are structures that confer adaptive ability to and facilitate the virulence of fungal pathogens. Certain multi-functional proteins have been shown to be involved in fungal pathogenesis and these proteins may also be implicated in biofilm formation. The aim of this study was to identify a fungal agent isolated from the human cornea, to analyze the ability of this organism to form biofilms in vitro and to investigate protein expression in this condition. The fungus was identified by phylogenetic inference analysis. Biofilm formation and structure were evaluated by colorimetric methods and by optical and electron microscopy. We also resolved proteins obtained from biofilms and planktonic cultures by two-dimensional gel electrophoresis and identified those proteins by mass spectrometry. The fungus was identified as Fusarium falciforme. Colorimetric analysis and microscopy revealed that the highest level of biofilm formation was obtained at a concentration of 1 × 106 conidia/mL with 96 h of incubation at 28 °C. The biofilm architecture consisted of an extracellular matrix that embedded fungal filaments. We found nineteen proteins that were over-expressed in biofilms, as compared with planktonic cultures, and six proteins with unique expression in biofilms. Among the more abundant proteins identified were: transketolase, a putative antigen 1, enolase, phosphoglycerate kinase and ATP-citrate synthase. Some of these proteins are involved in basal metabolism, function as multi-functional proteins or have been described as potential virulence factors. We focused on the expression in biofilm of the enzyme, enolase, which was determined by real-time PCR. Our findings provide a perspective on the proteins associated with the formation of biofilms in vitro by an F. falciforme keratitis isolate.
•This study represents a first approach to identifying OExP and UEP involved in F. falciforme biofilm formation.•It has been described a number of multi-functional proteins in biofilm and suggest a possible role in fungal infection.•Our studies set the stage for determination and for demonstration of these proteins as virulence factors.