Impact of contact lens group on antifungal efficacy of multipurpose disinfecting contact lens solutions.
ABSTRACT To evaluate and compare the in vitro effectiveness of multipurpose contact lens solutions (MPDS) to inhibit fungal colonization of Food and Drug Administration (FDA) contact lens groups.
Contact lenses from FDA groups I (low water content, nonionic), II (high water content, nonionic), III (low water content, ionic), and IV (high water content, ionic) were placed in sterile contact lens cases with 2 mL of ReNu MultiPlus, ReNu with MoistureLoc, or OPTI-FREE RepleniSH. Each contact lens-multipurpose solution combination was challenged with 0.1 mL of 10(6) colony-forming units/mL of Fusarium oxysporum and incubated at room temperature. Contact lenses and aliquots from phosphate-buffered saline rinse solutions, multipurpose solutions in cases, and lens cases were sampled at 24, 48, and 72 hours, plated on Sabouraud's agar, incubated at room temperature, and observed for growth (i.e., adhesion) for 1 to 7 days.
Used multipurpose contact lens solutions met or exceeded the 1-log reduction requirement of the FDA stand-alone test. Viable fungal colonies were recovered from group II lenses after 24 hours of storage in all three multipurpose solutions. Colonization was also detected with at least one contact lens-multipurpose solution pairing from groups I, III, and IV. Fungi were not recovered from lens-solution combinations after 24 hours or from phosphate-buffered saline solutions or lens cases at any period.
Antifungal activity of contaminated multipurpose solutions may be insufficient to prevent fungal colonization of contact lens materials despite meeting or exceeding the FDA stand-alone test criteria. Colonized lens may increase the risk of fungal keratitis.
[Show abstract] [Hide abstract]
ABSTRACT: Purpose: To investigate the susceptibility of different fungal corneal isolates to commercially available contact lens disinfecting solutions. Methods: Thirteen filamentous fungal isolates (9 Aspergillus spp, 3 Fusarium spp, 1 Curvularia sp.) recovered from corneal infections were used. The following solutions were tested: Arion Cronos, Complete Revitalens, Dua Elite, Opti-Free Express, Regard, Oxysept Comfort, and Oxysept Comfort without catalase. Suspensions of the different fungal isolates were made in the solutions (10(6) colony-forming units/mL). After 1 h (Arion Cronos only), 6, 8, and 24 h, aliquots of suspension were removed and seeded on Sabouraud agar plates. Results: After a 6-h exposure, only 3% hydrogen peroxide-based Oxysept Comfort without catalase eradicated all the fungi tested. All the other solutions were partly ineffective at killing some of the fungal isolates, even after a 24-h exposure. The worst performance was given by Regard and Dua Elite, which, after a 6-h exposure, showed growth of 12 and 10 of the 13 fungal strains tested, respectively. Conclusions: Most contact lens disinfecting solutions may not be sufficiently effective, if contact lens care systems become contaminated with filamentous fungi. In our experiment, only an exposure to 3% hydrogen peroxide without a neutralizer for at least 6 h was always able to kill an inoculum of different fungal strains.Journal of ocular pharmacology and therapeutics: the official journal of the Association for Ocular Pharmacology and Therapeutics 04/2013; DOI:10.1089/jop.2012.0052
[Show abstract] [Hide abstract]
ABSTRACT: PURPOSE: To compare the biocidal efficacy of contact lens care solutions against clinical isolates and the American Type Culture Collection (ATCC) 30631 reference strain of Fusarium species and to determine the ability of the organism to survive and grow in such systems. METHODS: The ISO 14729 reference method to assess biocidal efficacy was applied to the purified conidial form of 10 strains of Fusarium species. Six multipurpose disinfectant solutions (MPDSs), a one-step hydrogen peroxide (Per-1) system, a hydrogen peroxide-sodium chlorite (Per-2) system, and a one-step povidone iodine (PI) system were compared. Challenge organism viability was determined at various intervals, including the manufacturers' recommended disinfection time for the products (4 to 6 hours) and thereafter to 21 days. RESULTS: All MPDSs achieved a 3- to 4-log10 reduction in viability of ATCC 36031 within the recommended disinfection time of 6 hours. For the clinical strains, MPDS-1 (PQ-1 + alexidine) and MPDS-2 (PQ-1 + PHMB) produced 3 to 5 log10 kill after 6 hours. Multipurpose disinfectant solution 3 (PQ-1 + Aldox 0.0006%), MPDS-4 (PQ-1 + Aldox 0.0005% + C-9 ED3A), and MPDS-5 (PQ-1 + Aldox 0.0005%) showed reduced efficacy for the same two strains, with 0.6 to 1.7 log10 kill. Multipurpose disinfectant solution 6 (PHMB) gave 1.6 log10 for one strain and 3 to 4 log10 for the remainder. Growth in all the MPDS was not detected up to 21 days incubation. Per-1 showed less than 1 log10 kill at 6 hours for six of 10 strains, including ATCC 36031, and growth (1.2 to 2.7 log10) occurred with three of 10 strains by 7 days. Per-2 gave less than or equal to 0.5 log10 kill after 6- or 24-hour exposure without growth. The PI system showed 4 to 5 log10 kill for all strains tested by the first time point of 4 hours. However, with the exception of ATCC 36031, growth (1.7 to 4.0 log10) occurred with all strains by 7 days in PI. CONCLUSIONS: All MPDSs were effective against the ATCC 36031 reference strain of Fusarium solani. However, reduced efficacy was found for some MPDSs against the clinical isolates. Unlike MPDSs, peroxide- and povidone iodine-based systems have no continued antimicrobial presence once neutralized, and this can allow growth of surviving Fusarium in the solution. Accordingly, lenses should be subject to fresh disinfection if stored in such solutions for extended periods.Optometry and vision science: official publication of the American Academy of Optometry 04/2013; DOI:10.1097/OPX.0b013e31828f4dfe
[Show abstract] [Hide abstract]
ABSTRACT: To investigate the incidence of fungal contamination of store disinfectant solutions contained in contact lens storage cases belonging to asymptomatic contact lens users. Asymptomatic contact lens users were asked to bring their storage cases, lenses included, without having opened the lid of the cup after placing lenses inside. The following information was recorded: age, sex, type of refractive error, contact lens material, schedule of wear, and brand of disinfectant solution. Included subjects had to comply with lens handling, cleaning, and replacement instructions given by the manufacturer or their attending optometrist. One sample per cup of contact lens case was collected using a sterile syringe. Samples were cultured on proper media for 96 hr at 35°C. Fungi were identified to species level by standard methodology. A total of 216 samples were collected from 117 contact lens storage cases. All participants were using monthly disposable hydrogel lenses on a daily wear basis. Seven fungal species were isolated from 15 specimens (6.9%) collected from 12 storage cases (10.2%). These included one Fusarium solani, four Aspergillus niger, two Aspergillus fumigatus, five Candida parapsilosis, one Candida tropicalis, one Rhodotorula rubra, and one F. solani in combination with Candida guilliermondii. Disinfectant solutions containing hydrogen peroxide were found to be less effective than various alternative solutions in eliminating fungal species. The results of this study show that even when contact lens users report compliance for handling, cleaning, and replacement according to the manufacturer's instructions, the potential risk of contact lens-related fungal keratitis still remains.Eye & Contact Lens Science & Clinical Practice 12/2014; 41(2). DOI:10.1097/ICL.0000000000000069