Related Experiment Video
Updated: May 12, 2026
Broth Microdilution In Vitro Screening: An Easy and Fast Method to Detect New Antifungal Compounds
Published on: February 14, 2018
In vitro efficacy of contact lens solutions against various corneal fungal isolates
Antonio Pinna1, Donatella Usai, Stefania Zanetti
1Section of Ophthalmology, Department of Surgical, Microsurgical, and Medical Sciences, University of Sassari, Sassari, Italy. apinna@uniss.it
Purpose:
To investigate the susceptibility of different fungal corneal isolates to commercially available contact lens disinfecting solutions.
Methods:
Thirteen filamentous fungal isolates (9 Aspergillus spp, 3 Fusarium spp, 1 Curvularia sp.) recovered from corneal infections were used. The following solutions were tested: Arion Cronos, Complete Revitalens, Dua Elite, Opti-Free Express, Regard, Oxysept Comfort, and Oxysept Comfort without catalase. Suspensions of the different fungal isolates were made in the solutions (10(6) colony-forming units/mL). After 1 h (Arion Cronos only), 6, 8, and 24 h, aliquots of suspension were removed and seeded on Sabouraud agar plates.
Results:
After a 6-h exposure, only 3% hydrogen peroxide-based Oxysept Comfort without catalase eradicated all the fungi tested. All the other solutions were partly ineffective at killing some of the fungal isolates, even after a 24-h exposure. The worst performance was given by Regard and Dua Elite, which, after a 6-h exposure, showed growth of 12 and 10 of the 13 fungal strains tested, respectively.
Conclusions:
Most contact lens disinfecting solutions may not be sufficiently effective, if contact lens care systems become contaminated with filamentous fungi. In our experiment, only an exposure to 3% hydrogen peroxide without a neutralizer for at least 6 h was always able to kill an inoculum of different fungal strains.
Insights
Most contact lens solutions fail to kill fungi. Only 3% hydrogen peroxide without a neutralizer effectively eradicated all tested fungal isolates after a 6-hour exposure, highlighting potential risks with contaminated contact lens care systems.
Area of Science:
- Ophthalmology
- Mycology
- Microbiology
Background:
- Fungal keratitis is a serious eye infection.
- Contaminated contact lens solutions pose a risk for ocular infections.
- Filamentous fungi are common causes of fungal keratitis.
Purpose of the Study:
- To evaluate the efficacy of various commercial contact lens disinfecting solutions against fungal corneal isolates.
- To determine the susceptibility of Aspergillus, Fusarium, and Curvularia species to common disinfectants.
Main Methods:
- Thirteen fungal isolates from corneal infections were tested.
- Six commercially available contact lens solutions were evaluated.
- Fungal suspensions were exposed to solutions for 1, 6, 8, and 24 hours before plating on agar.
Main Results:
- Only 3% hydrogen peroxide (Oxysept Comfort without catalase) eradicated all fungi within 6 hours.
- Other solutions showed partial ineffectiveness, even after 24 hours.
- Regard and Dua Elite demonstrated the poorest performance, with significant fungal growth after 6 hours.
Conclusions:
- Many common contact lens disinfecting solutions may be insufficient for eliminating filamentous fungi.
- A 6-hour exposure to 3% hydrogen peroxide without a neutralizer is effective against a range of fungal strains.
- Proper disinfection protocols are crucial to prevent fungal contamination in contact lens care.
