Extracellular Proteases from Keratitis Causing Fusarium,Aspergillus and Dematiaceous Species

Volume 2 - Issue 2

Swati N Madhu¹, Anuradha K Pal² and Devarshi U Gajjar¹*

Received: January 30, 2019;   Published: February 08, 2019

DOI: 10.32474/TOOAJ.2018.02.000132

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Abstract

Purpose

Various types of hydrolytic enzymes, like proteases, lipases and phospholipases are important virulence factors produced by pathogenic fungi. In the present study quantification and characterization of proteases produced by different pathogenic Aspergillus, Fusarium and Dematiaceous Species isolated from corneal ulcers was done.

Method

Seven Aspergillus species, twelve Fusarium species and five Dematiaceous Species previously isolated from corneal ulcers were used in the present study. All isolates were grown in Sabarouds Dextrose Broth (SDB) and culture filtrate was obtained after 10 days of growth. Acetone precipitated culture filtrate was used as the source of protease. Characterization of proteases was done by assaying the activity at different pH (6-12), with inhibitors (PMSF, Pepstatin and EDTA) and gelatin zymography.

Result

In Aspergillus spp, maximum specific activity of protease was found in Aspergillus flavus and minimum specific activity was found in Aspergillus niger and Aspergillus tubingensis. In Fusarium spp., proteases from Fusarium solani Species complex (FSSC) showed more activity compared to F. delphinoides. Proteases from Aspergillus spp. and FSSC showed inhibition in presence of PMSF, while EDTA inhibited the proteases from F. delphinoides. In Dematiaceous group, Curvularia spp showed highest activity and were inhibited by PMSF.

Conclusion

It was concluded that fungi causing keratitis produce varying amounts and types of proteases. The difference in the specific activity of extracellular proteases among the isolates could indicate the differences in their pathogenic potential.

Keywords:Mycotic keratitis; Aspergillus spp; Fusarium spp; Proteases; Virulence factors

Abstract| Introduction| Material and Methods| Results| Discussion| Conclusion| References|