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Updated: May 8, 2026
Quantification of Acanthamoeba spp. Motility
Published on: September 20, 2024
Susceptibility of Acanthamoeba to multipurpose lens-cleaning solutions
Ana Paula Costa de Aguiar1, Caroline de Oliveira Silveira, Mari Aline Todero Winck
1Departamento de Microbiologia, Imunologia e Parasitologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil. annacaguiar@gmail.com
Abstract:
The present study investigated the susceptibility of Acanthamoeba spp. trophozoites to two multipurpose systems for cleaning and maintenance of contact lenses. Three strains of trophozoites from the ATCC (A. castellani T4, A. castellani Neff, and A. polyphaga) and two Acanthamoeba isolates obtained from swimming pools (PT5 and PO1) were placed in monoxenic culture. To test their survival in cleaning solutions for contact lenses, the trophozoites were exposed for 4 and 24 h to two multipurpose solutions (A and B), and were then inoculated into a new monoxenic culture. Amoebic growth on the plates was observed after 72 h of incubation. Trophozoites from all three ATCC strains and one isolate from a swimming pool (PO1) grew in all plates after 4 h of exposure to solutions A and B. After 24 h, the ATCC strains and the PO1 isolate showed growth in most of the plates treated. Only the PT5 isolate showed susceptibility to both solutions over the time intervals tested. The two solutions were not completely effective against most strains and isolates over the time intervals tested. These results are important, since species of Acanthamoeba are widely distributed in the environment and are potential agents of eye pathologies.
Insights
Contact lens solutions showed limited effectiveness against Acanthamoeba trophozoites. Most Acanthamoeba strains survived exposure, highlighting a potential risk for eye infections from contaminated lenses.
Area of Science:
- Microbiology
- Ophthalmology
- Parasitology
Background:
- Acanthamoeba species are ubiquitous environmental protozoa.
- These amoebae are known causative agents of serious eye infections, such as Acanthamoeba keratitis.
- Contact lens wearers are particularly at risk.
Purpose of the Study:
- To evaluate the efficacy of two multipurpose contact lens solutions against Acanthamoeba trophozoites.
- To determine the susceptibility of different Acanthamoeba strains and isolates to these solutions.
Main Methods:
- Three American Type Culture Collection (ATCC) strains and two environmental isolates of Acanthamoeba were used.
- Trophozoites were exposed to two multipurpose solutions (A and B) for 4 and 24 hours.
- Post-exposure, trophozoites were cultured to assess viability and growth.
Main Results:
- Most Acanthamoeba strains, including ATCC strains and one swimming pool isolate (PO1), survived exposure to both solutions for 4 and 24 hours.
- Only one isolate (PT5) demonstrated susceptibility to both solutions across the tested time intervals.
- The tested multipurpose solutions were not fully effective against the majority of Acanthamoeba strains and isolates.
Conclusions:
- Standard multipurpose contact lens solutions may not be sufficient to eliminate Acanthamoeba contamination.
- This finding underscores the potential risk of Acanthamoeba keratitis associated with contact lens hygiene.
- Further research into more effective disinfection methods for contact lenses is warranted.
