Evaluation of Adhesion and Co-culture Efficacy Assays of Antifungals and Chlorhexidine Against Acanthamoeba and Candida Species Associated with Severe Infectious Keratitis.

Severe infectious keratitis is a leading cause of corneal transplants and vision loss, primarily caused by microorganisms such as the protozoan genus Acanthamoeba spp. and the yeast Candida species. Treating these infections poses significant challenges, particularly in cases of polymicrobial keratitis. Both Acanthamoeba spp. and Candida species can adhere to contact lenses and the patient cornea, forming complex polymicrobial biofilms. This is the first study to explore polymicrobial biofilm formation involving Acanthamoeba and Candida. This study to evaluate adhesion and the co-culture between Acanthamoeba spp. and Candida albicans, as well as to analyze the antibiofilm efficacy of natamycin, voriconazole, and chlorhexidine against these microorganisms. Adhesion capacity was assessed using crystal violet dye, while drug susceptibility was evaluated using Trypan Blue dye. The results indicated that the strain A. castellanii and the clinical isolate R40 displayed a high capacity for adhesion. All treatments tested showed promising antibiofilm activity and were effective in eradicating biofilms of C. albicans and Acanthamoeba spp. Therefore, gaining a deeper understanding of the adhesion behavior of Acanthamoeba spp.-both independently and in association with Candida species along with evaluating the antibiofilm efficacy of various treatments, could enhance the management of severe polymicrobial keratitis. This research also contributes to assessing the effectiveness of multipurpose solutions for cleaning and maintaining contact lenses and their cases.