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Published on: June 5, 2012
Pseudomonas aeruginosa growth in Refresh Plus®.
Antonio Pinna1, Donatella Usai, Stefania Zanetti
1Section of Ophthalmology, Department of Surgery, Microsurgery, and Medico-surgical Specialties, University of Sassari, Sassari, Italy. apinna@uniss.it
Summary
Pseudomonas aeruginosa can grow in Refresh Plus, a preservative-free eye drop. Contaminated eye drops, especially if reused, may lead to severe keratitis.
Area of Science:
- Ophthalmology
- Microbiology
- Pharmaceutical Science
Background:
- Dry eye and post-LASIK surgery patients often use preservative-free ophthalmic solutions.
- Unit-dose eye drops are intended for single use to maintain sterility.
Purpose of the Study:
- To evaluate the growth potential of Pseudomonas aeruginosa in Refresh Plus, a unit-dose preservative-free ophthalmic solution.
- To understand the implications of potential contamination in ophthalmic solutions used for dry eye and post-LASIK care.
Main Methods:
- Inoculation of Refresh Plus with three clinical isolates of P. aeruginosa.
- Incubation at 25°C with sampling at 6, 12, and 24 hours.
- Culturing to determine bacterial population (CFU/mL) at each time point.
Main Results:
- P. aeruginosa demonstrated significant growth in Refresh Plus.
- Bacterial counts increased from approximately 100 CFU/mL to over 10^6 CFU/mL within 24 hours.
- All tested isolates showed robust replication in the ophthalmic solution.
Conclusions:
- Refresh Plus supports the growth of P. aeruginosa under experimental conditions.
- Contamination of unit-dose vials, particularly through reuse, poses a risk of bacterial proliferation.
- Potential for severe keratitis exists if contaminated solutions are used, highlighting the importance of proper usage.
