In vitro efficacy of a buffered chelating solution as an antimicrobial potentiator for antifungal drugs against fungal pathogens obtained from horses with mycotic keratitis.

The researchers in this study found that a specific chelating agent could improve the effectiveness of antifungal drugs against fungi obtained from horses with mycotic keratitis, an inflammatory condition of the eye.

Objective of the Study

The main aim of this research was to determine whether a novel third-generation chelating agent could enhance the in vitro activity of various antifungal medications. This chelating agent is a compound that binds to ions, potentially increasing the effectiveness of the antifungal drugs.

Methodology

• Fungal isolates were collected from horses suffering from mycotic keratitis. These included various types of fungi, such as Aspergillus, Fusarium, Penicillium, Cladosporium, and Curvularia.
• Four antifungal drugs (miconazole, ketoconazole, itraconazole, and natamycin) were tested individually and then in combination with the chelating agent. The aim was to compare the minimum inhibitory concentrations (MICs) – the smallest concentration of a drug that prevents the growth of a specific organism – both with and without the chelating agent.
• The researchers also used a common laboratory method known as the Clinical and Laboratory Standards Institute microdilution assay to assess the antifungal capacities of these drugs against the fungal isolates.

Results

• The results show that the addition of the chelating agent significantly reduced MIC values for the control strains and ophthalmic fungal isolates when paired with the antifungal drugs. This implies that a smaller dose of the drug was needed to prevent the growth of the organism by 50% and 90% when combined with the chelating agent.

Conclusion

• The chelating agent was found to enhance the antifungal efficacy of the drugs in vitro against common fungal pathogens isolated from eyes of horses with mycotic keratitis. This suggests that this agent could be used as a potent antimicrobial potentiator, potentially leading to more effective treatments for mycotic keratitis.