Contact lenses, solutions susceptible to contamination with fungal biofilms, study finds

In an in vitro model, clinical isolates of Fusarium and Candida albicans fungi formed biofilm structures associated with Fusarium keratitis on six brands of soft contact lenses, as well as in two brands of contact lens care solutions, researchers in Ohio reported.

"We also found that two recently isolated keratitis-associated fusaria formed robust biofilms, while the reference ATCC 36031 strain (recommended by the International Organization for Standardization guidelines for testing of disinfectants) failed to form biofilm," the authors said.

Mahmoud A. Ghannoum, PhD, and colleagues at University Hospitals Case Medical Center in Cleveland used three species of Fusarium and Candida albicans to develop and categorize biofilm formation associated with fungal keratitis.

"Our results showed that clinical isolates of Fusarium and C. albicans formed biofilms on all types of lenses tested and that the biofilm architecture varied with the lens type," the authors reported.

Additionally, the researchers found differences in hyphal content and structure among the biofilms formed by these fungi.

Phylogenetically diverse planktonic fusaria and Candida were susceptible to ReNu MoistureLoc (Bausch & Lomb) and MultiPlus (Bausch & Lomb) contact lens care solutions in the in vitro biofilm model. However, "Fusarium biofilms exhibited reduced susceptibility against these solutions in a species- and time-dependent manner," the authors noted.

Only the ReNu MoistureLoc and MultiPlus lens solutions were evaluated in the study, which is published in the January edition of Antimicrobial Agents and Chemotherapy.