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Evaluation of microbial contamination in multi-dose fluorescein eyedrops in a reference eye center
Camila de Moraes Costa1, Kayo Pinheiro Espósito1, Victor Medeiros Brandão Florêncio1
1Department of Ophthalmology, Fundação Altino Ventura, Recife, PE, Brazil.
Purpose:
To analyze the presence of microorganisms in fluorescein eyedrops used in a reference eye center in Recife-PE.
Methods:
This real-life and masked study evaluated fluorescein eyedrops used at the Altino Ventura Foundation in May 2019. Cultures were performed according to exposure times; I) three eyedrop bottles were analyzed after one day of use, II) three eyedrop bottles after 4 d of use, III) three eyedrop bottles after 8 d of use, and IV) three unopened bottles used as control. Samples were collected from the bottle's tip, instilled drop, and residual fluid. After incubation, all colonies were analyzed and identified through biochemical tests.
Results:
The contamination rate of the fluorescein eyedrop bottles in this study was 55.5% (5/9 vials). There was no contamination in the control group. The highest contamination was seen in one day exposed eyedrops, in 100% of the bottles. The bottle's tip had a higher rate of contamination compared to the drop and residual fluid. Gram-positive bacteria were isolated in 7/27 (25.9%) samples. Growth of fungi or gram-negative bacteria was not observed.
Conclusion:
The identification of gram-positive bacteria predominantly on the tip of the fluorescein eyedrop bottles suggests inadequate handling as the main cause of contamination.
Insights
Fluorescein eyedrop bottles showed a 55.5% contamination rate, primarily with gram-positive bacteria on the bottle tip. Inadequate handling is the likely cause of microbial contamination in these ophthalmic solutions.
Area of Science:
- Ophthalmology
- Microbiology
- Infectious Diseases
Background:
- Ophthalmic solutions, such as fluorescein eyedrops, are crucial for diagnostic procedures in eye care.
- Maintaining the sterility of eyedrop bottles is essential to prevent microbial contamination and subsequent ocular infections.
- Previous studies have indicated potential risks associated with microbial contamination in multi-use ophthalmic preparations.
Purpose of the Study:
- To investigate the prevalence of microbial contamination in fluorescein eyedrops used in a clinical setting.
- To identify the types of microorganisms present in contaminated eyedrop bottles.
- To determine the relationship between the duration of use and the rate of contamination.
Main Methods:
- A real-life, masked study was conducted evaluating fluorescein eyedrops from the Altino Ventura Foundation.
- Cultures were performed on eyedrop bottles after varying periods of use (1, 4, and 8 days) and on unopened control bottles.
- Samples were collected from the bottle tip, instilled drop, and residual fluid, followed by incubation and biochemical identification of colonies.
Main Results:
- A significant contamination rate of 55.5% (5/9 vials) was observed in the used fluorescein eyedrop bottles.
- No contamination was detected in the unopened control bottles.
- The highest contamination rate (100%) occurred in bottles after one day of use, with the bottle tip being the most frequently contaminated site. Gram-positive bacteria were identified in 25.9% of samples; no fungi or gram-negative bacteria were found.
Conclusions:
- The high prevalence of gram-positive bacteria, particularly on the bottle tip, suggests that handling practices are a primary factor in fluorescein eyedrop contamination.
- Adherence to aseptic techniques during the use of eyedrops is critical to minimize the risk of microbial contamination.
- Further research into optimal handling and storage protocols for ophthalmic solutions is warranted to ensure patient safety.
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