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Linaburg TJ, Hammersmith KM. Contact Lens-related Corneal Infections. Infect Dis Clin North Am 2024:S0891-5520(24)00061-8. [PMID: 39271302 DOI: 10.1016/j.idc.2024.07.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/15/2024]
Abstract
Our review provides an update on the current landscape of contact lens-associated microbial keratitis (MK). We discuss the prevalence and risk factors associated with MK, emphasizing the role of overnight wear, poor hygiene, and contact lens type. CL-related MK is commonly caused by bacteria, though can also be caused by fungi or protozoa. Clinical presentation involves ocular pain, redness, and vision loss, with more specific presenting symptoms based on the culprit organism. Treatment strategies encompass prevention through proper hygiene and broad-spectrum antibiotic, antifungal, or antiprotozoal therapy, with surgical management reserved for severe recalcitrant cases.
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Affiliation(s)
- Taylor J Linaburg
- Department of Ophthalmology, University of Pennsylvania, Scheie Eye Institute, 51 North 39th Street, Philadelphia, PA 19104, USA.
| | - Kristin M Hammersmith
- Department of Ophthalmology, University of Pennsylvania, Scheie Eye Institute, 51 North 39th Street, Philadelphia, PA 19104, USA
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Raghavan A, Rammohan R. Acanthamoeba keratitis - A review. Indian J Ophthalmol 2024; 72:473-482. [PMID: 38454853 PMCID: PMC11149514 DOI: 10.4103/ijo.ijo_2627_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 12/23/2023] [Indexed: 03/09/2024] Open
Abstract
This is a comprehensive review after a thorough literature search in PubMed-indexed journals, incorporating current information on the pathophysiology, clinical features, diagnosis, medical and surgical therapy, as well as outcomes of Acanthamoeba keratitis (AK). AK is a significant cause of ocular morbidity, and early diagnosis with timely institution of appropriate therapy is the key to obtaining good outcomes. The varied presentations result in frequent misdiagnosis, and co-infections can increase the morbidity of the disease. The first line of therapy continues to be biguanides and diamidines, with surgery as a last resort.
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Affiliation(s)
- Anita Raghavan
- Cornea & Refractive Surgery, Department of Microbiology, Aravind Eye Hospital and Post-Graduate Institute of Ophthalmology, Coimbatore, Tamil Nadu, India
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Ilyas M, Stapleton F, Willcox MDP, Henriquez F, Peguda HK, Rayamajhee B, Zahid T, Petsoglou C, Carnt NA. Epidemiology of and Genetic Factors Associated with Acanthamoeba Keratitis. Pathogens 2024; 13:142. [PMID: 38392880 PMCID: PMC10892102 DOI: 10.3390/pathogens13020142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 01/14/2024] [Accepted: 01/31/2024] [Indexed: 02/25/2024] Open
Abstract
Acanthamoeba keratitis (AK) is a severe, rare protozoal infection of the cornea. Acanthamoeba can survive in diverse habitats and at extreme temperatures. AK is mostly seen in contact lens wearers whose lenses have become contaminated or who have a history of water exposure, and in those without contact lens wear who have experienced recent eye trauma involving contaminated soil or water. Infection usually results in severe eye pain, photophobia, inflammation, and corneal epithelial defects. The pathophysiology of this infection is multifactorial, including the production of cytotoxic proteases by Acanthamoeba that degrades the corneal epithelial basement membrane and induces the death of ocular surface cells, resulting in degradation of the collagen-rich corneal stroma. AK can be prevented by avoiding risk factors, which includes avoiding water contact, such as swimming or showering in contact lenses, and wearing protective goggles when working on the land. AK is mostly treated with an antimicrobial therapy of biguanides alone or in combination with diaminidines, although the commercial availability of these medicines is variable. Other than anti-amoeba therapies, targeting host immune pathways in Acanthamoeba disease may lead to the development of vaccines or antibody therapeutics which could transform the management of AK.
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Affiliation(s)
- Muhammad Ilyas
- Primary & Secondary Healthcare Department, Punjab 54000, Pakistan; (M.I.)
| | - Fiona Stapleton
- School of Optometry and Vision Science, University of NSW, Sydney, NSW 2052, Australia (H.K.P.)
| | - Mark D. P. Willcox
- School of Optometry and Vision Science, University of NSW, Sydney, NSW 2052, Australia (H.K.P.)
| | - Fiona Henriquez
- School of Health and Life Sciences, The University of the West of Scotland, Glasgow G72 0LH, UK
| | - Hari Kumar Peguda
- School of Optometry and Vision Science, University of NSW, Sydney, NSW 2052, Australia (H.K.P.)
| | - Binod Rayamajhee
- School of Optometry and Vision Science, University of NSW, Sydney, NSW 2052, Australia (H.K.P.)
| | - Tasbiha Zahid
- Primary & Secondary Healthcare Department, Punjab 54000, Pakistan; (M.I.)
| | | | - Nicole A. Carnt
- School of Optometry and Vision Science, University of NSW, Sydney, NSW 2052, Australia (H.K.P.)
- Centre for Vision Research, Westmead Institute for Medical Research, Sydney, NSW 2145, Australia
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McCoy C, Patel S, Thulasi P. Update on the Management of Acanthamoeba Keratitis. CURRENT OPHTHALMOLOGY REPORTS 2022. [DOI: 10.1007/s40135-022-00296-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Kaufman AR, Tu EY. Advances in the management of Acanthamoeba keratitis: A review of the literature and synthesized algorithmic approach. Ocul Surf 2022; 25:26-36. [DOI: 10.1016/j.jtos.2022.04.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 04/10/2022] [Accepted: 04/12/2022] [Indexed: 01/01/2023]
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Nadia BA, Anis M, Ali SM, Ahmed M, Sana R, Mohamed G, Hechemi M, Leila K, Fethi K. Acanthamoeba keratitis in contact lens wearers in a tertiary center of Tunisia, North Africa. Ann Med Surg (Lond) 2021; 70:102834. [PMID: 34567549 PMCID: PMC8449026 DOI: 10.1016/j.amsu.2021.102834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 09/06/2021] [Accepted: 09/06/2021] [Indexed: 11/25/2022] Open
Abstract
PURPOSE To analyze the epidemiological and clinical features of Acanathamoeba keratitis AK and to assess the risk factors of this corneal infection in contact lens CL wearers in a tertiary center of Tunisia, North Africa. METHODS We carried out a retrospective study between January 2008 and December 2019 in the ophthtalmology department of a referral center, Sousse, Tunisia. A review of the chart of 248 patients using CL and diagnosed with presumed infectious keratitis was done.Socio demographic, risk behaviors and microbiological findings in case of AK were analyzed. The mean follow-up was 18 months (1 month-4 years). RESULTS AK was diagnosed in 29 cases (11.7% of contact lens wearers with infectious keratitis). These 29 cases were analyzed. The mean age at the time of diagnosis was 33, 44 ± 26, 9 years. Almost of the patients (13; 44.82%) used soft monthly disposable contact lenses. Some risk behaviors related to contact lens wearing were found in our study like not washing and drying hands before CL wear, sleeping in CL, topping off, not respecting the adequate replacement frequency and showering or swimming in CL.After treatment, visual acuity improved only in 10 cases (34.48%), remained the same in 11 cases (37.93%) and worsened in 8 cases (27.58%). CONCLUSION Clinicians must suspect AK in each CL wearer with suggestive clinical signs to allow earlier treatment and better prognosis. Public prevention messages that encourage CL wearers to respect the hygiene rules should be broadly applicable to each person using any type of CL, to minimize the risk of AK.
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Affiliation(s)
- Ben Abdesslem Nadia
- Department of Ophthalmology, Farhat Hached Hospital, Faculty of Medicine of Sousse, Sousse, 4000, Tunisia
| | - Mahjoub Anis
- Department of Ophthalmology, Farhat Hached Hospital, Faculty of Medicine of Sousse, Sousse, 4000, Tunisia
| | - Seghaier Mohamed Ali
- Department of Ophthalmology, Farhat Hached Hospital, Faculty of Medicine of Sousse, Sousse, 4000, Tunisia
| | - Mahjoub Ahmed
- Department of Ophthalmology, Farhat Hached Hospital, Faculty of Medicine of Sousse, Sousse, 4000, Tunisia
| | - Romdhani Sana
- Department of Ophthalmology, Farhat Hached Hospital, Faculty of Medicine of Sousse, Sousse, 4000, Tunisia
| | - Ghorbel Mohamed
- Department of Ophthalmology, Farhat Hached Hospital, Faculty of Medicine of Sousse, Sousse, 4000, Tunisia
| | - Mahjoub Hechemi
- Department of Ophthalmology, Farhat Hached Hospital, Faculty of Medicine of Sousse, Sousse, 4000, Tunisia
| | - Knani Leila
- Department of Ophthalmology, Farhat Hached Hospital, Faculty of Medicine of Sousse, Sousse, 4000, Tunisia
| | - Krifa Fethi
- Department of Ophthalmology, Farhat Hached Hospital, Faculty of Medicine of Sousse, Sousse, 4000, Tunisia
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Lacerda AG, Lira M. Acanthamoeba
keratitis: a review of biology, pathophysiology and epidemiology. Ophthalmic Physiol Opt 2020; 41:116-135. [DOI: 10.1111/opo.12752] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 09/07/2020] [Accepted: 09/09/2020] [Indexed: 01/13/2023]
Affiliation(s)
| | - Madalena Lira
- Centre of Physics University of Minho Braga Portugal
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Avdagic E, Chew HF, Veldman P, Tu EY, Jafri M, Doshi R, Boggild AK, Reidy JJ, Farooq AV. Resolution of Acanthamoeba Keratitis with Adjunctive Use of Oral Miltefosine. Ocul Immunol Inflamm 2019; 29:278-281. [PMID: 31829774 DOI: 10.1080/09273948.2019.1695853] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Purpose: To report a series of cases demonstrating the resolution of Acanthamoeba keratitis (AK) with adjunctive use of oral miltefosine.Methods: Retrospective case series.Results: The first case was a 27-year-old female who presented with severe pain and photophobia. The diagnosis of AK was made with confocal microscopy, which revealed a significant burden of stromal cysts. After approximately 2 weeks of adjunctive oral miltefosine therapy, there was a severe inflammatory response within the cornea followed by quick resolution of the AK. The second case was a 31-year-old male in whom the diagnosis of AK was confirmed by culture and polymerase chain reaction. Adjunctive oral miltefosine was started 3 months after presentation, leading to a quick resolution.Conclusions: Oral miltefosine may have cysticidal properties and should be considered as adjunctive therapy for the treatment of AK, particularly in cases with a significant burden of cysts or in cases recalcitrant to other treatments.
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Affiliation(s)
- Ema Avdagic
- Department of Ophthalmology and Visual Science, University of Chicago, Chicago, Illinois, USA
| | - Hall F Chew
- Department of Ophthalmology and Vision Science, University of Toronto, Toronto, Canada
| | - Peter Veldman
- Department of Ophthalmology and Visual Science, University of Chicago, Chicago, Illinois, USA
| | - Elmer Y Tu
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Mansab Jafri
- Kansas City University of Medicine and Biosciences, Kansas City, Missouri, USA
| | - Rutvi Doshi
- Department of Ophthalmology and Visual Science, University of Chicago, Chicago, Illinois, USA
| | - Andrea K Boggild
- Division of Infectious Diseases, Department of Medicine, University of Toronto, Toronto, Canada.,Tropical Disease Unit, Toronto General Hospital, Toronto, Canada.,Public Health Ontario Laboratory, Public Health Ontario, Toronto, Canada
| | - James J Reidy
- Department of Ophthalmology and Visual Science, University of Chicago, Chicago, Illinois, USA
| | - Asim V Farooq
- Department of Ophthalmology and Visual Science, University of Chicago, Chicago, Illinois, USA
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Li W, Wang Z, Qu J, Zhang Y, Sun X. Acanthamoeba keratitis related to contact lens use in a tertiary hospital in China. BMC Ophthalmol 2019; 19:202. [PMID: 31533675 PMCID: PMC6751601 DOI: 10.1186/s12886-019-1210-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Accepted: 08/30/2019] [Indexed: 12/17/2022] Open
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. Electronic supplementary material The online version of this article (10.1186/s12886-019-1210-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Weiwei Li
- Tianjin Eye Hospital, Tianjin Ophthalmology and Visual Development Key Laboratory, Clinical College of Ophthalmology, Tianjin Medical University, Address: 4, Gansu Road, Heping District, Tianjin, 300020, China
| | - Zhiqun Wang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Beijing Ophthalmology & Visual Sciences Key Laboratory, Capital Medical University, Address: 17 Hou Gou Lane, Chong Nei Street, Beijing, 100005, China
| | - Jinghao Qu
- Tianjin Eye Hospital, Tianjin Ophthalmology and Visual Development Key Laboratory, Clinical College of Ophthalmology, Tianjin Medical University, Address: 4, Gansu Road, Heping District, Tianjin, 300020, China
| | - Yang Zhang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Beijing Ophthalmology & Visual Sciences Key Laboratory, Capital Medical University, Address: 17 Hou Gou Lane, Chong Nei Street, Beijing, 100005, China
| | - Xuguang Sun
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Beijing Ophthalmology & Visual Sciences Key Laboratory, Capital Medical University, Address: 17 Hou Gou Lane, Chong Nei Street, Beijing, 100005, China.
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Optimized Protocol for Testing Multipurpose Contact Lens Solution Efficacy Against Acanthamoeba. Eye Contact Lens 2018; 44:367-371. [PMID: 29373390 DOI: 10.1097/icl.0000000000000477] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To evaluate the interlaboratory and intralaboratory reproducibility of a proposed protocol for multipurpose contact lens solution (MPS) disinfection efficacy against Acanthamoeba. METHODS Acanthamoeba castellanii and Acanthamoeba polyphaga and four MPS with different biocidal agents were used to evaluate the protocol in two different laboratories. In addition to the negative control, a positive control and neutralization control were used. One experiment was performed in triplicate, and all other experiments were performed in duplicate in each laboratory. Acanthamoeba trophozoites were grown axenically, and cysts were generated using the starvation method. Trophozoites and cysts at a concentration of 2.0 × 10 to 2.0 × 10 organisms per milliliter were exposed to the test MPS for 0, 4 or 6 (manufacturer's recommended soak time [MRST]), 8, and 24 hr. Survivors were determined by a limiting dilution method that used a most probable number evaluation. RESULTS The positive and negative controls displayed consistent results and trends both within each laboratory and between each laboratory for trophozoites and cysts of both A. castellanii and A. polyphaga. The neutralization control consistently demonstrated the ability of the neutralizing agents to neutralize the MPS and the positive control and demonstrated no inhibition of Acanthamoeba by the negative control. Testing in triplicate and duplicate demonstrated the reproducibility of the protocol both within each laboratory and between the laboratories. Our results demonstrated that the MPS at the MRST and at 8 hr (likely overnight soak time) are generally more effective against trophozoites than they are against cysts. Only the MPS with hydrogen peroxide as the biocidal agent was able to provide a greater than three-log kill of cysts at the MRST and longer. Among the MPS we tested, trophozoites of A. castellanii and A. polyphaga showed similar responses. Some variability was observed when testing cysts of both species. In both laboratories, one nonhydrogen peroxide containing MPS had some effect (>1 log kill) on A. polyphaga cysts. This solution had no effect (<1 log kill) on A. castellanii cysts, A. castellanii trophozoites, and A. polyphaga trophozoites. CONCLUSIONS The protocol that we have revised and evaluated is a well-controlled and reproducible procedure that can effectively evaluate the efficacy of MPS against Acanthamoeba trophozoites. Some variability was observed when testing the cyst stage.
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Contact Lenses and Infectious Keratitis. CURRENT OPHTHALMOLOGY REPORTS 2018. [DOI: 10.1007/s40135-018-0172-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Sant'Ana VP, Foronda AS, de Freitas D, Carrijo-Carvalho LC, de Souza Carvalho FR. Sensitivity of Enzymatic Toxins from Corneal Isolate of Acanthamoeba Protozoan to Physicochemical Parameters. Curr Microbiol 2017; 74:1316-1323. [PMID: 28755026 DOI: 10.1007/s00284-017-1319-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Accepted: 07/25/2017] [Indexed: 11/30/2022]
Abstract
Acanthamoeba is a free-living amoeba that causes severe corneal infection (Acanthamoeba keratitis) and produces a variety of extracellular enzymes, called exoproteome. Since physicochemical characters are suggested being associated with therapeutic profile and clinical severity of the infection, we investigated the physicochemical properties of proteolysis mediated by amoebic exoproteome. Corneal scraping was collected from a patient who showed typical symptoms of acute Acanthamoeba keratitis. Axenic amoeba was phylogenetically identified by 18S rDNA sequencing analysis. Effects of pH, temperature and diamidines on proteolysis mediated by exoproteome were assessed using zymography assays. Proteolytic enzymes were most active at pH 7.0 and 37 °C. Calcium ions decreased enzymatic activity. The main components of amoebic exoproteome were characterized as serine proteases. We demonstrated for the first time that commercial antimicrobial diamidines used for Acanthamoeba keratitis therapy inhibit enzymatic activity of amoebic exoproteome. Results showed the thermostability of Acanthamoeba proteases, which suggest a long-term effect of these virulence factors at the central and peripheral cornea with possible role in degradation of extracellular matrix components. Our findings open new perspectives about the complementary and unreported properties of antimicrobial compounds of the diamidine class on the inhibition of enzymatic activity and presumptive control of amoebic infection in the cornea.
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Affiliation(s)
- Viviane P Sant'Ana
- Department of Ophthalmology and Visual Sciences, Paulista School of Medicine, Federal University of Sao Paulo, Botucatu Street, 821, Vila Clementino, Sao Paulo, SP, 04023-062, Brazil
| | - Annette S Foronda
- Department of Ophthalmology and Visual Sciences, Paulista School of Medicine, Federal University of Sao Paulo, Botucatu Street, 821, Vila Clementino, Sao Paulo, SP, 04023-062, Brazil
| | - Denise de Freitas
- Department of Ophthalmology and Visual Sciences, Paulista School of Medicine, Federal University of Sao Paulo, Botucatu Street, 821, Vila Clementino, Sao Paulo, SP, 04023-062, Brazil
| | - Linda C Carrijo-Carvalho
- Department of Ophthalmology and Visual Sciences, Paulista School of Medicine, Federal University of Sao Paulo, Botucatu Street, 821, Vila Clementino, Sao Paulo, SP, 04023-062, Brazil.,Centro Universitário do Espírito Santo (UNESC), Colatina, Espirito Santo, Brazil
| | - Fábio Ramos de Souza Carvalho
- Department of Ophthalmology and Visual Sciences, Paulista School of Medicine, Federal University of Sao Paulo, Botucatu Street, 821, Vila Clementino, Sao Paulo, SP, 04023-062, Brazil. .,Centro Universitário do Espírito Santo (UNESC), Colatina, Espirito Santo, Brazil.
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Abstract
PURPOSE OF REVIEW This article reviews the literature on past and recent trends in contact lens-related microbial keratitis from bacterial, fungal, and Acanthamoeba infections. RECENT FINDINGS Contact lens wear is the most important risk factor for microbial keratitis. Despite increased use of daily disposable contact lens wear, the incidence of bacterial ulcers related to contact lens wear remains high. Overnight contact lens wear is the leading risk factor in contact lens-related bacterial infections. There may be a trend towards increasing antibiotic resistance of Gram-positive bacteria to fourth-generation fluoroquinolones. The incidence of Acanthamoeba and fungal infections, despite resolution of two outbreaks involving multipurpose solutions, are also on the rise. SUMMARY Contact lens-related microbial keratitis is rising and may be associated with more severe, vision threatening, infections.
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Inactivation of Acanthamoeba spp. and Other Ocular Pathogens by Application of Cold Atmospheric Gas Plasma. Appl Environ Microbiol 2016; 82:3143-3148. [PMID: 26994079 DOI: 10.1128/aem.03863-15] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 03/14/2016] [Indexed: 01/01/2023] Open
Abstract
Currently there are estimated to be approximately 3.7 million contact lens wearers in the United Kingdom and 39.2 million in North America. Contact lens wear is a major risk factor for developing an infection of the cornea known as keratitis due to poor lens hygiene practices. While there is an international standard for testing disinfection methods against bacteria and fungi (ISO 14729), no such guidelines exist for the protozoan Acanthamoeba, which causes a potentially blinding keratitis most commonly seen in contact lens wearers, and as a result, many commercially available disinfecting solutions show incomplete disinfection after 6 and 24 h of exposure. Challenge test assays based on international standard ISO 14729 were used to determine the antimicrobial activity of cold atmospheric gas plasma (CAP) against Pseudomonas aeruginosa, Candida albicans, and trophozoites and cysts of Acanthamoeba polyphaga and Acanthamoeba castellanii P. aeruginosa and C. albicans were completely inactivated in 0.5 min and 2 min, respectively, and trophozoites of A. polyphaga and A. castellanii were completely inactivated in 1 min and 2 min, respectively. Furthermore, for the highly resistant cyst stage of both species, complete inactivation was achieved after 4 min of exposure to CAP. This study demonstrates that the CAP technology is highly effective against bacterial, fungal, and protozoan pathogens. The further development of this technology has enormous potential, as this approach is able to deliver the complete inactivation of ocular pathogens in minutes, in contrast to commercial multipurpose disinfecting solutions that require a minimum of 6 h.
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Heaselgrave W, Kilvington S. The Characterization of an Adrenergic Signalling System Involved in the Encystment of the Ocular Pathogen Acanthamoeba spp. J Eukaryot Microbiol 2016; 63:629-34. [PMID: 26941040 DOI: 10.1111/jeu.12312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 02/24/2016] [Accepted: 02/24/2016] [Indexed: 11/29/2022]
Abstract
The aim of this study was to identify and characterize the receptor system involved in controlling encystment in Acanthamoeba using specific agonists and antagonists and to examine whether endogenous stores of catecholamines are produced by the organism. Acanthamoeba trophozoites suspended in axenic growth medium were exposed to adrenoceptor agonists and antagonists to determine which compounds promoted or prevented encystment. Second, trophozoites were cultured in medium containing a catecholamine synthesis inhibitor to investigate the effect this had on natural encystment. Nonspecific adrenoceptor agonists including epinephrine, isoprotenerol, and the selective β1 adrenoceptor agonist dobutamine were found to cause > 90% encystment of Acanthamoeba trophozoites compared to < 30% with the controls. The selective β1 antagonist metoprolol was able to inhibit epinephrine mediated encystment by > 55%. Cultures of Acanthamoeba with the catecholamine synthesis inhibitor α-methyl-p-tyrosine significantly reduced the level of amoebic encystment compared to controls. In conclusion, Acanthamoeba appear to contain a functional adrenergic receptor system of unknown structure which is involved in initiating the encystment process that can be activated and blocked by β1 agonists and antagonists respectively. Furthermore, the presence of this receptor system in Acanthamoeba indicates that topical β adrenoceptor blockers may be effective adjunct therapy by reducing the transformation of trophozoites into the highly resistant cyst stage.
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Affiliation(s)
- Wayne Heaselgrave
- School of Biomedical Science, University of Wolverhampton, MA Building, Wulfruna Street, Wolverhampton, WV1 1LY, United Kingdom
| | - Simon Kilvington
- Department of Infection Immunity and Inflammation, University of Leicester, Medical Sciences Building, University Road, Leicester, LE1 9HN, United Kingdom
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Sarnicola E, Sarnicola C, Sabatino F, Tosi GM, Perri P, Sarnicola V. Early Deep Anterior Lamellar Keratoplasty (DALK) for Acanthamoeba Keratitis Poorly Responsive to Medical Treatment. Cornea 2016; 35:1-5. [DOI: 10.1097/ico.0000000000000681] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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