Abstract
Purpose :
One of the most common fungus that causes infections is Fusarium spp. This fungus is considered an important agent of human keratitis in Mexico. Biofilm formation is one adaptation that allowed fungus pathogenicity. Fungal biofilm is an exopolymeric matrix that protects fungus for environmental conditions. Biofilm requires differential genes and proteins expression involved in its formation compared to agitation growth. Proteins expressed are probably related to virulence factors. In this study we established the Fusarium solani biofilm and analyzed fungus proteomic expression in biofilm condition and agitation growth.
Methods :
Genomic DNA was obtained from a saprobiotic and clinic keratitis isolates. The ITS region and elongation factor α (EFα) were amplified by PCR. The sequences obtained were analyzed by phylogenetic inference. Biofilm formation standardization was carried in 96-well plates at 4, 8, 12, 24 and 48h at concentrations of 1x104, 1x105 and 1x106 conidia/mL at 28°C. Electronic microscopy was made at 48h in a concentration of 1x105 conidia/mL. Proteomic analysis was made on two isolates, grown in agitation and biofilm conditions. This analysis consisted in total proteins extraction, quantitation proteins, isoelectrofocusing and 2D gels. Identification of protein was performed by means of mass spectrometry.
Results :
Isolates were identified as F. solani by phylogenetic inference. The optimum conditions for biofilm formation for both isolate were observed at a concentration of 1x105 conidia/ml, 48h at 28°C. Micrographs were obtained from optical and electronic microscopy. Those showed biofilm formation in both cultures. Proteomic profile was made from the two isolates grown in biofilm condition and in agitation. Analysis showed differences in expression of certain proteins or their isoforms. Identification of 35 proteins was made from biofilm condition from both cultures. We found 13 proteins shared in both isolates, 13 unique proteins for saprobiotic isolate and nine unique proteins for clinical isolate. Proteins were described, most of basal metabolism, transmembrane transporters, transcription factors and two potential virulence factors.
Conclusions :
Proteomic analysis showed significant differences between both isolates and 35 proteins were identified with differential expression. These results suggest that important pathways are differentially regulated depending of origin and type of growth.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.