Are metabolites of Fusarium oxysporum responsible for fungal skin invasion? A morphological and Raman spectroscopy monitoring

Abstract

Fusarium is an emerging pathogen with high levels of morbidity and mortality. A significant tissue response is observed in infected patients, and the condition has been associated with the production of toxic metabolites. The aim of the present study was to identify a major fraction of crude metabolic extract of Fusarium oxysporum and investigate its effects on the skin of healthy rats. Fraction F1 was obtained from the cultivation of F. oxysporum in Czapek–Dox. In the treatment groups, fraction F1 (0.05 mg/ ml) was injected intradermally, while (50 µl) 0.9% of saline solution was injected in the control groups. The animals were killed 3, 6, 12, and 24 h after inoculation. The skin was fixed for inclusion in paraffin to obtain histological sections and stained with hematoxylin and eosin, Sirius red, and terminal deoxynucleotidyl transferase‐mediated dUTP nick‐end labeling. Samples were analyzed using Fourier transform Raman spectroscopy. The tissue reactions were classified and compared over time and by treatment. In the treatment group, inflammatory reaction peaked at 6 h, being classified as moderate, with infiltrate composed mainly of neutrophils. terminal deoxynucleotidyl transferase‐mediated dUTP nick‐end labeling staining was negative. The area occupied by types I and III collagen in the treatment group increased over time. There was a change in the area occupied by amide I and the ratios of the –CH2 and –CH3 molecules. It can be argued that the fraction F1 contains elements that contribute to the invasion of Fusarium in the skin, destructurizing the organization of the extracellular matrix. Copyright © 2014 John Wiley & Sons, Ltd.

Recent advances in linear and non‐linear Raman spectroscopy. Part IX

“…Sibin Melo and co‐workers used morphological and Raman spectroscopy monitoring to address the question of whether metabolites of Fusarium oxysporum are responsible for fungal skin invasion. They found that it can be argued that the major fraction of Fusarium oxysporum contains elements that contribute to the invasion of Fusarium in the skin and destructurizing the organization of the extracellular matrix . Stewart and colleagues used Raman molecular imaging to distinguish between renal oncocytoma and chromophobe renal cell carcinoma.…”

Decellularized Bovine Skeletal Muscle Scaffolds: Structural Characterization and Preliminary Cytocompatibility Evaluation

“…Autologous muscle graft (AMG) is the most recommended and used approach in orthopedics to reestablish muscle integrity [6]. However, AMG is related to several complications, such as the risk of graft failure, prolonged surgical exposure time, development of opportunistic infections, and tissue necrosis [7,8]. The use of allografts or xenografts is even more restricted as the greater risk of rejection and immunosuppressive therapy are related to several complications, such as kidney failure, hypertension, and gastrointestinal and liver problems, among others [9].…”

Exocellular extract of Fusarium oxysporum, fungus free, is able to permeate and act selectively in skin

“…We have studied the effects of Fusarium oxysporum metabolites in the skin to simulate the condition imposed by microorganism naturally (14)(15)(16). We demonstrate that when low molecular weight molecules (including mycotoxins) were removed from a crude extract produced by Fusarium, the remaining extract retained its ability to permeate the skin and cause undesirable toxic effects, such as inflammatory response, apoptosis (14,15), necrosis, and disorganization of the extracellular matrix (16,17) even in the fungal absence. This observation shows that apparently the host inflammatory response is not necessarily directed to the presence of the fungus, but to possible compounds produced by it and released through tissue.…”