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.

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 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 Acanthamoeba keratitis related to contact lens in a tertiary hospital in China

2019 ◽  
Author(s):  
Weiwei Li ◽  
Zhiqun Wang ◽  
Jinghao Qu ◽  
Yang Zhang ◽  
Xuguang Sun
Keyword(s):  
Confocal Microscopy ◽  
Contact Lens ◽  
Contact Lenses ◽  
Early Stage ◽  
Tap Water ◽  
Acanthamoeba Keratitis ◽  
Tertiary Hospital ◽  
Chi Square ◽  
Soft Contact Lenses ◽  
Chi Square Test

Abstract Backgroud To report the clinical and microbiological features of Acanthamoeba keratitis (AK) related to contact lens in a tertiary hospital in China. Methods In this retrospective study, medical results of 61 cases of AK related to contact lens were reviewed from January 2000 to December 2017. The data included patients’ demographics, lens type, history, risk factors, the disease stages, reports of corneal scrapings and culture, treatment. Moreover, the genotype identification of part of these isolates was carried out with a PCR assay and sequence analysis of the 18S ribosomal DNA gene. Results There were 64 eyes included in the study. And 32.8% of cases wore soft contact lenses, 67.2% of patients used overnight orthokeratology. In the cases (20eyes) of early stage, 65% (13 eyes) had positive results in Giemsa stained smears, trophozoites were seen in 7 eyes (35%) in 0.9% sodium chloride (NaCl) wet mounts. Six eyes (30%) were diagnosed by confocal microscopy together with clinical sign. In the orthokeratology patients, 87.8% (36/41) of cases rinsed the lenses and/or cases with tap water, while 55% of soft lens wearers wore their lens during showering. The genotype of 9 isolates was determined, all the strains belonged to genotype T4. In the orthokeratology related cases, patients required therapeutic penetrating keratoplasty after 2005 were less than before 2005 (Chi-square test, χ2= 4.209，P = 0.04). Conclusions More than two thirds of cases were associated with orthokeratology. The examinations of Giemsa stained smears, 0.9% NaCl wet mounts and confocal microscopy should be done for the highly suspected cases of early stage to help the early diagnosis. The rate of therapeutic keratoplasty was decrease after 2005 compare with before 2005 in the cases of orthokeratology.

scholarly journals Acanthamoeba keratitis related to contact lens use in a tertiary hospital in China

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Weiwei Li ◽  
Zhiqun Wang ◽  
Jinghao Qu ◽  
Yang Zhang ◽  
Xuguang Sun
Keyword(s):  
Confocal Microscopy ◽  
Contact Lens ◽  
Contact Lenses ◽  
Early Stage ◽  
Tap Water ◽  
Clinical Signs ◽  
Acanthamoeba Keratitis ◽  
Tertiary Hospital ◽  
Soft Contact Lenses ◽  
Number Of Patients

Abstract Background To report the clinical and microbiological features of Acanthamoeba keratitis (AK) related to contact lens use in a tertiary hospital in China. Methods In this retrospective study, the medical results of 61 cases of AK related to contact lens use from January 2000 to December 2017 were reviewed. The data included patients’ demographics, lens type, history, risk factors, disease stages, corneal scraping and culture reports, and treatments. Moreover, genotypic identification of some of the isolates was carried out with a PCR assay and sequence analysis of the 18S ribosomal DNA gene. Results There were 64 eyes included in the study. A total of 32.8% of the patients wore soft contact lenses, and 67.2% of patients used overnight orthokeratology. In the cases (20 eyes) in the early stage, 65% (13 eyes) had positive results according to Giemsa-stained smears, and 0.9% sodium chloride (NaCl) wet mounts revealed trophozoites in 7 eyes (35%). Six eyes (30%) were diagnosed by confocal microscopy combined with clinical signs. In the orthokeratology patients, 87.8% (36/41) rinsed their lenses and/or cases with tap water; 55% of soft-lens wearers wore their lenses while showering. The genotype of 9 isolates was determined, and all the strains belonged to genotype T4. In the orthokeratology group, the number of patients who required therapeutic penetrating keratoplasty after 2005 was less than that before 2005 (chi-square test, χ2 = 4.209, P = 0.04). Conclusions More than two-thirds of the cases were associated with orthokeratology. Examinations with Giemsa-stained smears, 0.9% NaCl wet mounts and confocal microscopy should be performed for patients who are highly suspected of having early-stage AK to help with early diagnosis. In the orthokeratology group, the rate of therapeutic keratoplasty after 2005 was less than that before 2005.

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 Acanthamoeba keratitis related to contact lens use in a tertiary hospital in China

2019 ◽  
Author(s):  
Weiwei Li ◽  
Zhiqun Wang ◽  
Jinghao Qu ◽  
Yang Zhang ◽  
Xuguang Sun
Keyword(s):  
Confocal Microscopy ◽  
Contact Lens ◽  
Contact Lenses ◽  
Early Stage ◽  
Tap Water ◽  
Clinical Signs ◽  
Acanthamoeba Keratitis ◽  
Tertiary Hospital ◽  
Soft Contact Lenses ◽  
Number Of Patients

Abstract Background: To report the clinical and microbiological features of Acanthamoeba keratitis (AK) related to contact lens use in a tertiary hospital in China. Methods: In this retrospective study, the medical results of 61 cases of AK related to contact lens use from January 2000 to December 2017 were reviewed. The data included patients’ demographics, lens type, history, risk factors, disease stages, corneal scraping and culture reports, and treatments. Moreover, genotypic identification of some of the isolates was carried out with a PCR assay and sequence analysis of the 18S ribosomal DNA gene. Results: There were 64 eyes included in the study. A total of 32.8% of the patients wore soft contact lenses, and 67.2% of patients used overnight orthokeratology. In the cases (20 eyes) in the early stage, 65% (13 eyes) had positive results according to Giemsa-stained smears, and 0.9% sodium chloride (NaCl) wet mounts revealed trophozoites in 7 eyes (35%). Six eyes (30%) were diagnosed by confocal microscopy combined with clinical signs. In the orthokeratology patients, 87.8% (36/41) rinsed their lenses and/or cases with tap water; 55% of soft-lens wearers wore their lenses while showering. The genotype of 9 isolates was determined, and all the strains belonged to genotype T4. In the orthokeratology group, the number of patients who required therapeutic penetrating keratoplasty after 2005 was less than that before 2005 (chi-square test, χ 2 = 4.209, P = 0.04). Conclusions: More than two-thirds of the cases were associated with orthokeratology. Examinations with Giemsa-stained smears, 0.9% NaCl wet mounts and confocal microscopy should be performed for patients who are highly suspected of having early-stage AK to help with early diagnosis. In the orthokeratology group, the rate of therapeutic keratoplasty after 2005 was less than that before 2005.

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.

Nanomaterials in the Management of Contact Lens-Associated Ocular Complication

2021 ◽  
pp. 1-5
Keyword(s):  
Optical Properties ◽  
Surface Functionalization ◽  
Contact Lens ◽  
Contact Lenses ◽  
New Technology ◽  
Large Population ◽  
Bacterial Biofilm ◽  
Ocular Infection ◽  
Ocular Complication ◽  
Amoebic Keratitis

Contact lens is the transparent hemisphere-shaped ophthalmic product worn by a large population all across the globe for improving vision. It is applied to the cornea of the eye not only for improving vision but also for the delivery of drugs. The contact lens has many benefits but it also causes several ophthalmic infections which include amoebic keratitis, fungal, bacterial, and viral keratitis. The development of bacterial biofilm in lens cases exacerbates the ocular infection after the application of contact lenses in the cornea. Contact lens often associated with discomfort and dry eye. Coating these contact lens with different nanomaterials and an antimicrobial agent is a very good approach to improve the quality and biological activity of lenses. Surface functionalization is the most commonly adopted, and versatile method to tailor the optical properties. This review highlights the new technology to achieve the sustained release of drugs from contact lens by controlling their chemical, mechanical, and optical properties..

scholarly journals Acanthamoeba keratitis related to contact lens use in a tertiary hospital in China

2019 ◽  
Author(s):  
Weiwei Li ◽  
Zhiqun Wang ◽  
Jinghao Qu ◽  
Yang Zhang ◽  
Xuguang Sun
Keyword(s):  
Confocal Microscopy ◽  
Contact Lens ◽  
Contact Lenses ◽  
Early Stage ◽  
Tap Water ◽  
Clinical Signs ◽  
Acanthamoeba Keratitis ◽  
Tertiary Hospital ◽  
Soft Contact Lenses ◽  
Number Of Patients

Abstract Background: To report the clinical and microbiological features of Acanthamoeba keratitis (AK) related to contact lens use in a tertiary hospital in China. Methods: In this retrospective study, the medical results of 61 cases of AK related to contact lens use from January 2000 to December 2017 were reviewed. The data included patients’ demographics, lens type, history, risk factors, disease stages, corneal scraping and culture reports, and treatments. Moreover, genotypic identification of some of the isolates was carried out with a PCR assay and sequence analysis of the 18S ribosomal DNA gene. Results: There were 64 eyes included in the study. A total of 32.8% of the patients wore soft contact lenses, and 67.2% of patients used overnight orthokeratology. In the cases (20 eyes) in the early stage, 65% (13 eyes) had positive results according to Giemsa-stained smears, and 0.9% sodium chloride (NaCl) wet mounts revealed trophozoites in 7 eyes (35%). Six eyes (30%) were diagnosed by confocal microscopy combined with clinical signs. In the orthokeratology patients, 87.8% (36/41) rinsed their lenses and/or cases with tap water; 55% of soft-lens wearers wore their lenses while showering. The genotype of 9 isolates was determined, and all the strains belonged to genotype T4. In the orthokeratology group, the number of patients who required therapeutic penetrating keratoplasty after 2005 was less than that before 2005 (chi-square test, χ 2 = 4.209, P = 0.04). Conclusions: More than two-thirds of the cases were associated with orthokeratology. Examinations with Giemsa-stained smears, 0.9% NaCl wet mounts and confocal microscopy should be performed for patients who are highly suspected of having early-stage AK to help with early diagnosis. In the orthokeratology group, the rate of therapeutic keratoplasty after 2005 was less than that before 2005.

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