In vitro susceptibility and multilocus sequence typing of Fusarium isolates causing keratitis

Area of Science:

• Ophthalmology
• Mycology
• Molecular Biology

Background:

• Fungal keratitis is a major cause of vision loss, particularly in developing nations.
• Accurate identification of fungal pathogens is crucial for effective treatment of fungal eye infections.

Purpose of the Study:

• To perform molecular identification of Fusarium species responsible for fungal keratitis.
• To determine the antifungal susceptibility profiles of these Fusarium isolates.

Main Methods:

• Molecular identification using RNA polymerase gene (RPB2) and translation elongation factor 1-alpha (TEF1).
• Antifungal susceptibility testing via broth microdilution according to Clinical and Laboratory Standards Institute (CLSI) guidelines.

Main Results:

• Fusarium solani species complex (including F. solani, F. keratoplasticum, F. falciforme) and Fusarium oxysporum species complex were the predominant isolates.
• Amphotericin B and natamycin demonstrated the highest efficacy against all tested Fusarium isolates.
• Voriconazole showed significant antifungal activity, though less potent than amphotericin B and natamycin.

Conclusions:

• Molecular identification is vital for understanding Fusarium epidemiology in fungal keratitis.
• Distinct antifungal susceptibility patterns were observed among different Fusarium complexes.
• Effective treatment of fungal keratitis requires targeted antifungal selection based on species identification and susceptibility testing.