scholarly journals Evaluating Alternate Methods of Determining the Antimicrobial Efficacy of Contact Lens Care Products against Acanthamoeba Trophozoites

Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 126 ◽  
Author(s):  
Allison Campolo ◽  
Paul Shannon ◽  
Monica Crary
Keyword(s):  
Propidium Iodide ◽  
Contact Lens ◽  
Acanthamoeba Keratitis ◽  
Antimicrobial Efficacy ◽  
Ocular Infection ◽  
Outer Membranes ◽  
Log Reduction ◽  
Free Living Amoeba ◽  
Corneal Damage ◽  
Rapid Tool

Acanthamoeba keratitis (AK) is a serious ocular infection caused by a ubiquitous free-living amoeba, Acanthamoeba. This infection often results in extensive corneal damage and blindness, and is notoriously difficult to cure. While Acanthamoeba is an abundant organism, AK is most associated with contact lens hygiene noncompliance and inadequate contact lens care (CLC) disinfection regimens. Thus, accurate and timely antimicrobial efficacy testing of CLC solutions is paramount. Published methods for antimicrobial efficacy testing of Acanthamoeba trophozoites requires 14 days for results. Presently, alternate and/or rapid methods for evaluating CLC products rarely demonstrate equivalent results compared to commonly-reported methods. Propidium iodide is a cellular stain that can only bind to cells with damaged outer membranes. We evaluated propidium iodide staining as an alternative method for determining the relative antimicrobial efficacy of 11 different CLC products against Acanthamoeba trophozoites. Following exposure to a CLC product, the fluorescence intensity of propidium iodide in an Acanthamoeba population demonstrated a strong correlation to the log reduction determined by established, growth-based Acanthamoeba testing used to evaluate the antimicrobial efficacy of CLC products. Thus, propidium iodide was found to be an effective rapid tool for determining cell death in Acanthamoeba trophozoites following exposure to CLC solutions.

scholarly journals Comparison of Hydrogen Peroxide Contact Lens Disinfection Systems and Solutions against Acanthamoeba polyphaga

2001 ◽  
Vol 45 (7) ◽  
pp. 2038-2043 ◽  
Author(s):  
Reanne Hughes ◽  
Simon Kilvington
Keyword(s):  
Hydrogen Peroxide ◽  
Contact Lens ◽  
Lens Protein ◽  
Sodium Perborate ◽  
Acanthamoeba Polyphaga ◽  
Log Reduction ◽  
Disinfection Process ◽  
Free Living Amoeba ◽  
One Step ◽  
Corneal Damage

ABSTRACT Acanthamoeba is a free-living amoeba causing a potentially blinding infection of the cornea. Contact lens wearers are most at risk and account for some 95% of cases. Hydrogen peroxide is used for contact lens disinfection due to its broad antimicrobial activity. Lenses must be neutralized before use to avoid pronounced stinging and possible corneal damage. Neutralization is achieved by adding a catalyst during the disinfection process (one-step) or afterwards (two-step). Here, the activities of commercial peroxide systems and individual solutions against trophozoites and cysts ofAcanthamoeba polyphaga were compared. All disinfection systems were active against trophozoites, giving a ≥3-log (99.9%) kill within 1 h. Of the four one-step systems, only one showed some cysticidal activity, giving a 1.28 ± 0.41-log reduction. Both two-step systems were cysticidal, giving a ≥3-log kill at 4 h. All system peroxide solutions were cysticidal, giving a ≥3-log kill by 4 to 6 h. Variation in the cysticidal rate was observed with two solutions that gave a 1.8- to 2.1-log kill at 4 h compared with 3.0 to 4.0 for the rest (P < 0.05). No cysticidal activity was found with the peroxigen sodium perborate or the contact lens protein remover subtilisin A. Two-step systems are cysticidal providing contact times of at least 4 h are employed. Variation in cyst killing occurs between peroxide solutions, possibly due to formulation differences. One-step systems are less effective againstAcanthamoeba cysts due to rapid peroxide neutralization. The cysticidal activity of one-step systems could be improved if neutralization rates were retarded.

scholarly journals Continuous Real-Time Motility Analysis of Acanthamoeba Reveals Sustained Movement in Absence of Nutrients

Pathogens ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 995
Author(s):  
Allison Campolo ◽  
Valerie Harris ◽  
Rhonda Walters ◽  
Elise Miller ◽  
Brian Patterson ◽  
...  
Keyword(s):  
Contact Lens ◽  
Contact Lenses ◽  
Axenic Culture ◽  
Acanthamoeba Keratitis ◽  
Ocular Infection ◽  
Glass Coverslip ◽  
E Coli ◽  
Total Distance ◽  
Care Systems ◽  
Different Strains

Acanthamoeba keratitis is a serious ocular infection which is challenging to treat and can lead to blindness. While this pathogen is ubiquitous and can contaminate contact lenses after contact with water, its habits remain elusive. Understanding this organism’s natural behavior will better inform us on how Acanthamoeba colonize contact lens care systems. Acanthamoeba trophozoites were allowed to adhere to either a glass coverslip or non-nutrient agar (NNA) within a flow cell with nutrients (Escherichia coli or an axenic culture medium (AC6)) or without nutrients (Ringer’s solution). Images were taken once every 24 s over 12 h and compiled, and videos were analyzed using ImageJ Trackmate software. Acanthamoeba maintained continuous movement for the entire 12 h period. ATCC 50370 had limited differences between conditions and surfaces throughout the experiment. Nutrient differences had a noticeable impact for ATCC 30461, where E. coli resulted in the highest total distance and speed during the early periods of the experiment but had the lowest total distance and speed by 12 h. The Ringer’s and AC6 conditions were the most similar between strains, while Acanthamoeba in the E. coli and NNA conditions demonstrated significant differences between strains (p < 0.05). These results indicate that quantifiable visual tracking of Acanthamoeba may be a novel and robust method for identifying the movement of Acanthamoeba in relation to contact lens care products. The present study indicates that Acanthamoeba can undertake sustained movement for at least 12 h with and without nutrients, on both rough and smooth surfaces, and that different strains have divergent behavior.

scholarly journals Enhanced Killing of Acanthamoeba Cysts with a Plant Peroxidase-Hydrogen Peroxide-Halide Antimicrobial System

2003 ◽  
Vol 69 (5) ◽  
pp. 2563-2567 ◽  
Author(s):  
Reanne Hughes ◽  
Peter W. Andrew ◽  
Simon Kilvington
Keyword(s):  
Hydrogen Peroxide ◽  
Horseradish Peroxidase ◽  
Contact Lens ◽  
Acanthamoeba Keratitis ◽  
Free Living ◽  
Soybean Peroxidase ◽  
Plant Peroxidase ◽  
Time Points ◽  
Free Living Amoeba ◽  
Care Systems

ABSTRACT The activity of H2O2 against the resistant cyst stage of the pathogenic free-living amoeba Acanthamoeba was enhanced by the addition of KI and either horseradish peroxidase or soybean peroxidase or, to a lesser degree, lactoperoxidase. This resulted in an increase in the cysticidal activity of 3% (wt/vol) H2O2, and there was >3-log killing in 2 h, compared with the 6 h required for comparable results with the peroxide solution alone (P < 0.05). With 2% H2O2, enhancement was observed at all time points (P < 0.05), and total killing of the cyst inoculum occurred at 4 h, compared with 6 h for the peroxide alone. The activity of sublethal 1% H2O2 was enhanced to give 3-log killing after 8 h of exposure (P < 0.05). No enhancement was obtained when KCl or catalase was used as a substitute in the reaction mixtures. The H2O2 was not neutralized in the enhanced system during the experiments. However, in the presence of a platinum disk used to neutralize H2O2 in contact lens care systems, the enhanced 2% H2O2 system gave 2.8-log killing after 6 h or total cyst killing by 8 h, and total neutralization of the H2O2 occurred by 4 h. In contrast, 2% H2O2 alone resulted in <0.8-log killing of cysts in the presence of the platinum disk due to rapid (<1 h) neutralization of the peroxide. Our observations could result in significant improvement in the efficacy of H2O2 contact lens disinfection systems against Acanthamoeba cysts and prevention of acanthamoeba keratitis.

scholarly journals Orthokeratology lens-related Acanthamoeba keratitis: case report and analytical review

2021 ◽  
Vol 49 (3) ◽  
pp. 030006052110009
Author(s):  
Jinfang Wu ◽  
Huatao Xie
Keyword(s):  
Contact Lens ◽  
Vision Loss ◽  
Tap Water ◽  
Significant Risk ◽  
Acanthamoeba Keratitis ◽  
Ocular Infection ◽  
Increased Risk ◽  
Analytical Review ◽  
Relative Rarity ◽  
Common Risk Factors

Acanthamoeba keratitis (AK) is a rare but severe ocular infection with a significant risk of vision loss. Contact lens use is the main risk factor for AK. The orthokeratology (OK) lens, a specially designed contact lens, has been used worldwide as an effective method of myopia control. However, the OK lens is associated with an increased risk of Acanthamoeba infection. Many primary practitioners are concerned about this infection because of its relative rarity, the lack of promising therapeutic medications, and the need for referral. We herein report two cases of AK associated with OK lenses, present a systematic review of such cases, and discuss the possible reasons for the higher incidence rate of this infection in patients who wear OK lenses. We combined the clinical knowledge and skills of corneal specialists and lens experts with the sole objective of addressing these OK lens-related AK cases. We found that the most common risk factors were rinsing the lenses or lens cases with tap water. Prompt and accurate diagnosis along with adequate amoebicidal treatment are essential to ensure desirable outcomes for OK lens wearers who develop AK. Appropriate OK lens parameters and regular checkups are also important.

scholarly journals Results of case-control studies support the association between contact lens use and Acanthamoeba keratitis

2013 ◽  
pp. 991 ◽  
Author(s):  
Elena Pacella ◽  
La Torre ◽  
De Giusti ◽  
Brillante ◽  
Lombardi ◽  
...  
Keyword(s):  
Contact Lens ◽  
Acanthamoeba Keratitis ◽  
Case Control ◽  
Case Control Studies

A chlorhexidine contact lens disinfection tablet: design criteria and antimicrobial efficacy in potable tap water

1991 ◽  
Vol 14 (3) ◽  
pp. 99-108 ◽  
Author(s):  
Yolande Anthony ◽  
David J.G. Davies ◽  
Brian J. Meakin ◽  
Janet Halliday ◽  
Ravinder Kumar ◽  
...  
Keyword(s):  
Contact Lens ◽  
Tap Water ◽  
Antimicrobial Efficacy ◽  
Design Criteria

scholarly journals First Report of a Case of Ocular Infection Caused by Purpureocillium lilacinum in Poland

Pathogens ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1046
Author(s):  
Robert Kuthan ◽  
Anna K. Kurowska ◽  
Justyna Izdebska ◽  
Jacek P. Szaflik ◽  
Anna Lutyńska ◽  
...  
Keyword(s):  
Contact Lens ◽  
Pars Plana Vitrectomy ◽  
Penetrating Keratoplasty ◽  
Visual Outcome ◽  
Ocular Infection ◽  
Corneal Perforation ◽  
Purpureocillium Lilacinum ◽  
First Case ◽  
Pars Plana ◽  
Tof Ms

This report describes the first case of an ocular infection induced by Purpureocillium lilacinum in Poland. The patient was a 51-year-old immunocompetent contact lens user who suffered from subacute keratitis and progressive granulomatous uveitis. He underwent penetrating keratoplasty for corneal perforation, followed by cataract surgery due to rapid uveitic cataract. A few weeks later, intraocular lens removal and pars plana vitrectomy were necessary due to endophthalmitis. The patient was treated with topical, systemic, and intravitreal voriconazole with improvement; however, the visual outcome was poor. The pathogen was identified by MALDI-TOF MS.

Awareness of Contact Lens Related Ocular Complications among Opticians of Lahore

2021 ◽  
Vol 37 (4) ◽  
Author(s):  
Ahmed Sohail ◽  
Zain Ul Abideen ◽  
Fatima Zahid ◽  
Wahid Bakhsh
Keyword(s):  
Contact Lens ◽  
Contact Lenses ◽  
Corneal Opacity ◽  
Acanthamoeba Keratitis ◽  
Bacterial Keratitis ◽  
Age Group ◽  
Cross Sectional Survey ◽  
Ocular Complications ◽  
Cross Sectional ◽  
One Year

Purpose:  To determine the awareness regarding contact lens related ocular complications among opticians of Lahore and to find out the relationship between the awareness and their educational qualification. Study Design:  Cross sectional survey. Place and duration of Study: University of Lahore from April 2020- December 2020. Methods:  This survey included opticians of different areas of Lahore, Pakistan. Two hundred and eleven opticians responded to a pre-tested, structured close ended questionnaire. Data comprised of demographics and contact lens selling experience. Information regarding awareness about contact lens related complications was also sought. The data were analyzed using SPSS 25.0. Results:  A total of 211 opticians participated in the survey. All subjects were males. Fifty four (25.6%) subjects were from the age group of 15 to 30 years, 122 (57.8%) were from the age group of 31 to 45 and 35 (16.6%) were from the age group of 46 to 60 years. Only 4.7% had contact lens dispensing diploma. Thirty seven percent patients had contact lens selling experience of 2 to 10 years. Similar percentage had more than 10 years of experience. Ten percent had less than one year of experience. Only 54 participants out of 211 had knowledge about dry eye, 9 knew about Acanthamoeba keratitis and Bacterial keratitis and only 2 were aware of corneal opacity. Conclusion:  Majority of the opticians of Lahore are unaware of the contact lenses related complications. Sale of cosmetic lenses for fashion purpose should be discouraged and banned if not prescribed by optometrist/ ophthalmologist. Key Words:  Opticians, Contact lenses, Bacterial Keratitis.

scholarly journals Draft Genome Sequences of Eight Pseudomonas aeruginosa Corneal Infection Isolates

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Vishnu Raghuram ◽  
Joanna B. Goldberg
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Contact Lens ◽  
Draft Genome ◽  
Ocular Infection ◽  
Bacterial Keratitis ◽  
Genome Sequences ◽  
Content Type ◽  
Corneal Infection

Pseudomonas aeruginosa is the major cause of bacterial keratitis, a sight-threatening ocular infection that can occur in contact lens wearers, as well as in others. Here, we report the draft genomes of 8 different P. aeruginosa corneal isolates, adding to the list of publicly available corneal infection-associated P. aeruginosa genomes.

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