Efficacy Of Multipurpose Solutions Research Articles

Biocidal efficacy of multipurpose solutions against Gram‐negative organisms associated with corneal infiltrative events

BackgroundBecause corneal infiltrative events () may result from bacterial components on contact lenses, which can come from contaminated lens cases, we evaluated the biocidal efficacy of five multipurpose solutions against Gram‐negative commonly isolated and ‐associated organisms.MethodsOf the multipurpose solutions tested, one contained polyhexamethylene biguanide (PHMB)/polyquaternium‐1 (PQ‐1; Bausch & Lomb Incorporated: Biotrue), one contained alexidine dihydrochloride (alexidine)/PQ‐1 (AMO: RevitaLens OcuTec) and three contained PQ‐1/myristamidopropyl dimethylamine (MAPD; Alcon: Opti‐Free PureMoist, PQ‐1/‐1; Opti‐Free RepleniSH, PQ‐1/MAPD‐2; Opti‐Free Express, PQ‐1/MAPD‐3). Challenge organisms were CIE‐associated Achromobacter xylosoxidans, Delftia acidovorans and Stenotrophomonas maltophilia at manufacturer‐recommended durations (stand‐alone), in lens cases without lenses (up to seven days) and in lens cases with etafilcon A lenses (up to 30 days).ResultsIn stand‐alone testing against CIE‐associated organisms, PHMB/PQ‐1 and alexidine/PQ‐1 were significantly superior versus MAPD‐based multipurpose solutions against A. xylosoxidans (all p ≤ 0.01), D. acidovorans (all p ≤ 0.001) and S. maltophilia (all p ≤ 0.05). In lens cases, PHMB/PQ‐1 and alexidine/PQ‐1 achieved greater than 3‐log reductions against all challenge organisms at all times evaluated. PQ‐1/MAPD‐1 achieved a greater than 3‐log reduction against D. acidovorans at 24 hours; PQ‐1/MAPD‐1 and PQ‐1/MAPD‐3 achieved greater than 3‐log reductions at seven days against all organisms. In lens cases with lenses, PHMB/‐1 and alexidine/PQ‐1 achieved greater than 3‐log reductions against all organisms at all times. PQ‐1/MAPD‐1 and PQ‐1/MAPD‐3 achieved greater than 3‐log reductions at seven or more days against all organisms. PQ‐1/MAPD‐2 did not achieve a greater than 3‐log reduction at any time; some regrowth was observed.ConclusionsPHMB‐ and alexidine‐based multipurpose solutions demonstrated significantly greater biocidal activity compared with PQ‐1/MAPD‐based agents against Gram‐negative organisms commonly isolated and CIE‐associated pathogens.

Does the presence of QAC genes in staphylococci affect the efficacy of disinfecting solutions used by orthokeratology lens wearers?

Background/aimThere has been increasing evidence of the emergence of antiseptic resistance mediated by quaternary ammonium compound (QAC) resistance genes, which may reduce the efficacy of disinfection. Although the presence of...

Do multipurpose contact lens disinfecting solutions work effectively against non-FDA/ISO recommended strains of bacteria and fungi?

Recent outbreaks of microbial keratitis have increased concerns about the efficacy of multipurpose solutions (MPS) against 'real-world' organisms. This study determined, in accordance with FDA/ISO standard methods, the effects of five MPS against clinical isolates and type strains of bacteria, and isolates of fungi from subjects' ocular structures; and of three MPS against environmental fungal isolates. MPS were challenged with bacteria (type strains (ATCC) and clinical isolates of bacterial pathogens obtained from a district hospital laboratory) and with fungal isolates from both the periocular and conjunctival structures and from environmental air. All MPS demonstrated at least a 3-log reduction of challenged cell viability of all bacterial species tested, with the exception of MPS D against a canine infection Staphylococcus aureus isolate. Whilst all MPS tested were able to effect a 1.0-log reduction of viability of Fusarium solani (ATCC 36031), only two MPS had 90% viability reduction against all fungi of human origin and only one of these against all environmental fungal isolates. Effectiveness of these two solutions against fungal isolates compared to the remaining three MPS was found to be statistically significant (p = 0.003). All MPS demonstrated a 99.9% viability reduction against a wide range of bacteria including major ocular pathogens not currently included in the FDA panel. The inability of three MPS to achieve a 90% reduction against fungal isolates is of concern as there has been a recent upsurge in reports of fungal keratitis. We would recommend extension of the current FDA testing panel for MPS to include more fungal isolates.

Efficacy of multipurpose solutions against Acanthamoeba species

Aim The disinfection efficacy of contact lens multipurpose solutions (MPSs) against Acanthamoeba polyphaga (Ros) and Acanthamoeba castellanii (ATCC30868) cysts and trophozoites was determined by both biocidal and manufacturer-recommended no-rub/rinse regimen testing. Methods A biocidal assay using four MPSs (ReNu ® with MoistureLoc ®, Opti-free Express, Solo-care Plus, and Complete MoisturePlus) was conducted with or without the presence of organic soil. A second test procedure compared the ability of five MPSs (ReNu with MoistureLoc MPS, ReNu MultiPlus, Opti-free Express, Solo-care Aqua, and Complete MoisturePlus) to remove and kill Acanthamoeba species cysts and trophozoites from SofLens 38 and Surevue conventional hydrogel lenses, and Focus Night & Day silicone hydrogel lenses using the manufacturer-recommended regimen. Results In the biocidal assay, only ReNu with MoistureLoc successfully killed both trophozoites and cysts (>3 log) within the manufacturer-recommended soak time. A >3 log decrease in trophozoites, but not cysts, was reported for Opti-free Express; however, Solo-care Plus and Complete MoisturePlus did not reduce the number of cysts or trophozoites by >3 log during the manufacturer-recommended soak time. In the no-rub/rinse regimen tests, only ReNu with MoistureLoc removed an inoculum of 2 × 10 5 trophozoites or cysts from SofLens 38 and Surevue hydrogel lenses, as well as Focus Night & Day silicone hydrogel lenses. Less than 10 viable organisms were recovered from the lenses after the 10 s rinse and 4 h soak. Opti-free Express, Solo-care Aqua, and ReNu MultiPlus were effective at removing trophozoites and cysts from SofLens 38 and Surevue conventional hydrogel lenses, but not from Focus Night & Day silicone hydrogel lenses. In excess of 10 viable organisms were recovered from all lenses after the manufacturer-recommended regimen using Complete MoisturePlus. Conclusions These data suggest that some MPSs, when used as recommended by the manufacturer, are more effective at killing representative strains of Acanthamoeba than others.

A comparison of cyst age and assay method of the efficacy of contact lens disinfectants againstAcanthamoeba

AIMS(i) To determine effect of Acanthamoeba cyst age, method of production, and (ii) to assay technique on the efficacy of multipurpose solutions (MPS) and hydrogen peroxide based contact lens disinfectants....