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Dart JKG, Papa V, Rama P, Knutsson KA, Ahmad S, Hau S, Sanchez S, Franch A, Birattari F, Leon P, Fasolo A, Mrukwa-Kominek E, Jadczyk-Sorek K, Carley F, Parwez H, Minassian DC. Acanthamoeba keratitis treatment outcomes compared for drug delivery by protocol versus physician's individualised treatment. Ocul Surf 2025:S1542-0124(25)00052-7. [PMID: 40204130 DOI: 10.1016/j.jtos.2025.03.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2024] [Revised: 03/12/2025] [Accepted: 03/31/2025] [Indexed: 04/11/2025]
Abstract
PURPOSE To compare Acanthamoeba keratitis (AK) outcomes for treatment delivered using a detailed protocol versus physician's individualised treatment. METHODS This double cohort study compared the outcomes of these different delivery methods for PHMB 0.02% and diamidine 0.1% dual therapy. The primary outcome was the medical cure rate without surgery within 12 months (MCR_12) and the secondary was visual acuity. Any change of treatment, any surgery, or treatment for >12 months was a failure. Outcomes were both unadjusted and adjusted, using multivariable analysis, for baseline differences affecting outcomes. Patients were from two centres in Milan and London treated at different times; the individualised cohort (1991-2012) and per-protocol cohort (2017-2021). RESULTS The individualised cohort included 96 and the per-protocol 47 patients. Both unadjusted and adjusted results were similar. The unadjusted outcomes for both centres combined showed significantly improved outcomes for per-protocol treatment with a 1.59-fold improvement in MCR_12 (95% CI 1.40 - 1.80, p < 0.001) and a 2.1-fold increase in visual acuity ≥ 20/25 (95% CI 1.34 - 3.29, p < 0.001). Amongst potential confounding factors examined, neither baseline AK disease stage, treatment centre nor the type of diamidine significantly influenced outcomes. CONCLUSIONS This study shows significant advantages for the use of protocol delivered versus individualised treatment for AK. The use of evidence-based treatment delivery protocols, like the one used here for AK, might improve outcomes for all causes of microbial keratitis and could offer practitioners and patients the benefit of having an easy-to-follow drug delivery protocol, with known outcomes.
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Affiliation(s)
- John K G Dart
- Moorfields Eye Hospital NHS Foundation Trust, London, UK; National Institute of Health Research (NIHR) Moorfields Biomedical Research Centre, London, UK.
| | - Vincenzo Papa
- SIFI S.p.A., 36, Via Ercole Patti, 95025 Aci S. Antonio (Catania), Italy
| | - Paolo Rama
- Cornea and Ocular Surface Unit, San Raffaele Scientific Institute, Milan, Italy
| | | | - Saj Ahmad
- Moorfields Eye Hospital NHS Foundation Trust, London, UK; National Institute of Health Research (NIHR) Moorfields Biomedical Research Centre, London, UK
| | - Scott Hau
- Moorfields Eye Hospital NHS Foundation Trust, London, UK; National Institute of Health Research (NIHR) Moorfields Biomedical Research Centre, London, UK
| | - Sara Sanchez
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | | | | | - Pia Leon
- Ophthalmic Unit, Ospedale SS Giovanni e Paolo, Venice, Italy
| | - Adriano Fasolo
- Research Unit, The Veneto Eye Bank Foundation, Venice, Italy
| | - Ewa Mrukwa-Kominek
- Professor K. Gibiński University Clinical Center of Medical University of Silesia in Katowice, Poland; Department of Ophthalmology, Faculty of Medical Sciences in Katowice, Medical University of Silesia in Katowice, Poland
| | - Katarzyna Jadczyk-Sorek
- Professor K. Gibiński University Clinical Center of Medical University of Silesia in Katowice, Poland; Department of Ophthalmology, Faculty of Medical Sciences in Katowice, Medical University of Silesia in Katowice, Poland
| | | | - Hossain Parwez
- Clinical Experimental Sciences, Faculty of Medicine, University of Southampton & University Hospitals Southampton NHS Trust; National Institute of Health Research (NIHR) Southampton Clinical Research Facility
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Marques-Couto P, Monteiro M, Ferreira AM, Pinheiro-Costa J, Vilares-Morgado R. Acanthamoeba Keratitis Management and Prognostic Factors: A Systematic Review. J Clin Med 2025; 14:2528. [PMID: 40217976 PMCID: PMC11989993 DOI: 10.3390/jcm14072528] [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: 03/10/2025] [Revised: 03/24/2025] [Accepted: 03/31/2025] [Indexed: 04/14/2025] Open
Abstract
Background/Objectives: The aim of this study was to review the therapeutic and prognostic factors influencing Acanthamoeba Keratitis (AK) management. Methods: A systematic search was performed across MEDLINE® (via PubMed), Web of Science®, and Scopus®, following the PRISMA 2020 guidelines, and registered in PROSPERO (CRD420251010774). Studies reporting AK treatment regiments and prognostic factors were included. After extracting the data from the included articles, the relevant aspects of the treatment and the prognostic factors were compared and summarized. Results: Sixty-one articles were included: nine were prospective, including 3 randomized controlled trials (RCTs), and fifty-two were retrospective. The findings suggest that therapeutic epithelial debridement (TED), followed by an association with biguanides, diamidines, and an antibacterial agent, is a strong initial treatment option. An adjunctive medical treatment with topical voriconazole 1% or oral miltefosine may also be considered. Surgical approaches were also assessed when the pharmaceutical therapy failed, with Deep Anterior Lamellar Keratoplasty (DALK) playing an important role in the cases without a deep stroma involvement. Early Therapeutic Penetrating Keratoplasty (TPK) should be used as a salvage therapy and Optical Penetrating Keratoplasty (OPK) should be used for rehabilitation purposes. Key prognostic factors include older age, delayed diagnosis, corticosteroid use before prompt diagnosis, poor initial best corrected visual acuity (BCVA), and AK stage at presentation. Conclusions: The initial treatment with TED, biguanides, and diamidines remains the foundation of treatment. Surgical options can be considered in advanced cases. An early diagnosis, age, and initial BCVA are prognosis factors that should be considered. Future research may focus on improvement of protocols and searching for novel agents.
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Affiliation(s)
- Pedro Marques-Couto
- Department of Ophthalmology, Unidade Local de Saúde São João, 4200-319 Porto, Portugal
| | - Mariana Monteiro
- Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal
| | | | - João Pinheiro-Costa
- Department of Ophthalmology, Unidade Local de Saúde São João, 4200-319 Porto, Portugal
- RISE-Health, Surgery and Physiology Department, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal
| | - Rodrigo Vilares-Morgado
- Department of Ophthalmology, Unidade Local de Saúde São João, 4200-319 Porto, Portugal
- RISE-Health, Surgery and Physiology Department, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal
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Zhao N, Liang L, Hao M, Liu D, Fan Z, Wu J, Cheng Y. A case series of overnight orthokeratology-related Acanthamoeba keratitis in Northwest China: Clinical presentation, management, and outcomes. Cont Lens Anterior Eye 2025:102406. [PMID: 40097321 DOI: 10.1016/j.clae.2025.102406] [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: 08/26/2024] [Revised: 02/10/2025] [Accepted: 03/07/2025] [Indexed: 03/19/2025]
Abstract
PURPOSE To report a series of overnight orthokeratology-related Acanthamoeba keratitis (OK-AK) at a teriary transfer care eye hospital in China from January 1, 2021, to February 29, 2024, and to provide a reference for its treatment. METHODS This was a single-center, retrospective case study. Records of patients with a history of OK lens use who were diagnosed with AK were analyzed. Data on clinical presentation, management, and outcomes were analyzed. We also preliminarily investigated behaviors associated with the risk of OK-AK. RESULTS A total of 11 patients were included (8 females, 3 males, 14 eyes). The mean age was 14.7 ± 3.6 years (range: 11-22 years). All patients were using OK for an average of 3.5 ± 2.4 years (range: 1-8 years) before the onset of AK. The median time from onset of symptoms to diagnosis was 5 days (range: 2-150 days). The most frequently presented symptoms were blurred vision (n=11, 100%), redness (n=8, 72.7%), and excruciating eye pain (n=8, 72.7%). Topical anti-amoebic agents (a combination of topical polyhexamethylene biguanide [PHMB], metronidazole, and voriconazole) were used in all infected eyes once the AK diagnosis was made. Systemic metronidazole and/or voriconazole were added in stromal keratitis. Eight eyes (57.1%) were cured by medication. The remaining eyes (6/14, 42.9%) underwent therapeutic keratoplasty surgery because of poor response or rapid progression of the disease. The surgeries included two lamellar keratoplasty (ALK), one deep lamellar keratoplasty (DALK), and three therapeutic penetrating keratoplasty (TPK). Recurrence occurred in two cases (2/6, 33.3%), one after 1 year following DALK and the other 3 months after TPK. All patients had improved visual acuity after treatment. CONCLUSION This findings indicate that OK-AK is a serious problem in Northwest China. AK should be suspected early in patients with OK lens use who present with clinical symptoms such as eye redness and pain. The medication cure rate in OK-AK was 57.1%. The early keratoplasty surgery rate was 42.9%, and the risk of post-operation recurrence should be a concern. Based on the above findings, clinicians need to establish a standardized follow-up system and carry out multi-dimensional user education.
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Affiliation(s)
- Na Zhao
- Department of Pharmacy, First Affiliated Hospital of Northwest University, Xi'an No.1 Hospital, Xi'an 710002 Shaanxi Province, China
| | - Le Liang
- Department of Pharmacy, First Affiliated Hospital of Northwest University, Xi'an No.1 Hospital, Xi'an 710002 Shaanxi Province, China
| | - Mi Hao
- Department of Ophthalmology, First Affiliated Hospital of Northwest University, Xi'an No.1 Hospital, Xi'an 710002 Shaanxi Province, China
| | - Dong Liu
- Department of Ophthalmology, First Affiliated Hospital of Northwest University, Xi'an No.1 Hospital, Xi'an 710002 Shaanxi Province, China
| | - Zhiyu Fan
- Department of Pharmacy, First Affiliated Hospital of Northwest University, Xi'an No.1 Hospital, Xi'an 710002 Shaanxi Province, China
| | - Jie Wu
- Department of Ophthalmology, First Affiliated Hospital of Northwest University, Xi'an No.1 Hospital, Xi'an 710002 Shaanxi Province, China; Shaanxi Institute of Ophthalmology, Xi'an 710002 Shaanxi Province, China; Ophthalmic Disease Clinical Medical Research Center of Shaanxi, Xi'an 710002 Shaanxi Province, China
| | - Yan Cheng
- Department of Ophthalmology, First Affiliated Hospital of Northwest University, Xi'an No.1 Hospital, Xi'an 710002 Shaanxi Province, China; Shaanxi Institute of Ophthalmology, Xi'an 710002 Shaanxi Province, China; Ophthalmic Disease Clinical Medical Research Center of Shaanxi, Xi'an 710002 Shaanxi Province, China.
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Leccisotti A, Fields SV, De Bartolo G, Crudale C, Posarelli M. Optical Coherence Tomography in Infectious Keratitis After Femtosecond Keratorefractive Surgery. J Clin Med 2025; 14:1067. [PMID: 40004598 PMCID: PMC11856634 DOI: 10.3390/jcm14041067] [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: 12/01/2024] [Revised: 01/21/2025] [Accepted: 02/02/2025] [Indexed: 02/27/2025] Open
Abstract
Objectives: Anterior Segment Optical coherence tomography (AS-OCT) can help in the diagnosis and treatment of infectious keratitis, but it has not been studied in cases occurring after corneal refractive surgery procedures such as femtosecond laser in situ keratomileusis (FS-LASIK) and keratorefractive lenticule extraction (KLEx). In these procedures, a surgical interface is created, where infections usually start, thus determining a different AS-OCT pattern compared to non-surgical infections, which begin on the corneal surface. Methods: We retrospectively reviewed 22,756 eyes of 13,564 patients who underwent FS-LASIK and KLEx at our surgical center. Results: Four cases of post-refractive surgery infectious keratitis were included (two after FS-LASIK and two after KLEx), in which the AS-OCT identified an initial infiltrate in the interface, followed by interface inflammation. In one case, after FS-LASIK, interface fluid accumulation occurred. In one case, after KLEx, diffuse interface inflammation led to stromal reabsorption, later compensated by stromal reformation and epithelial hyperplasia, well documented by OCT. Conclusions: AS-OCT represents a useful tool for assessing corneal infections after refractive surgery, guiding the treatment, and evaluating the healing process and residual corneal scarring.
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Affiliation(s)
- Antonio Leccisotti
- Siena Eye Laser, 53036 Poggibonsi, Italy; (S.V.F.); (G.D.B.); (C.C.); (M.P.)
- School of Biomedical Sciences, Ulster University, Coleraine BT52 1SA, UK
- Centre for Research in Refractive Surgery, 53035 Siena, Italy
| | - Stefania V. Fields
- Siena Eye Laser, 53036 Poggibonsi, Italy; (S.V.F.); (G.D.B.); (C.C.); (M.P.)
- Centre for Research in Refractive Surgery, 53035 Siena, Italy
| | - Giuseppe De Bartolo
- Siena Eye Laser, 53036 Poggibonsi, Italy; (S.V.F.); (G.D.B.); (C.C.); (M.P.)
- Centre for Research in Refractive Surgery, 53035 Siena, Italy
| | - Christian Crudale
- Siena Eye Laser, 53036 Poggibonsi, Italy; (S.V.F.); (G.D.B.); (C.C.); (M.P.)
- Centre for Research in Refractive Surgery, 53035 Siena, Italy
| | - Matteo Posarelli
- Siena Eye Laser, 53036 Poggibonsi, Italy; (S.V.F.); (G.D.B.); (C.C.); (M.P.)
- Centre for Research in Refractive Surgery, 53035 Siena, Italy
- Department of Ophthalmology, Liverpool University, Liverpool L3 5TR, UK
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Hafezi F, Messerli J, Torres-Netto EA, Lu NJ, Aydemir ME, Hafezi NL, Hillen M. Same-session dual chromophore riboflavin/UV-A and rose bengal/green light PACK-CXL in Acanthamoeba keratitis: a case report. EYE AND VISION (LONDON, ENGLAND) 2025; 12:2. [PMID: 39748383 PMCID: PMC11697719 DOI: 10.1186/s40662-024-00420-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2024] [Accepted: 11/27/2024] [Indexed: 01/04/2025]
Abstract
BACKGROUND Acanthamoeba keratitis (AK) is the most challenging corneal infection to treat, with conventional therapies often proving ineffective. While photoactivated chromophore for keratitis-corneal cross-linking (PACK-CXL) with riboflavin/UV-A has shown success in treating bacterial and fungal keratitis, and PACK-CXL with rose bengal/green light has demonstrated promise in fungal keratitis, neither approach has been shown to effectively eradicate AK. This case study explores a novel combined same-session treatment approach using both riboflavin/UV-A and rose bengal/green light in a single procedure. CASE PRESENTATION A 44-year-old patient with active AK in the left cornea, unresponsive to 10 months of conventional treatment according to American Academy of Ophthalmology (AAO) guidelines, was treated using same-session sequential PACK-CXL with riboflavin/UV-A (365 nm) irradiation (10 J/cm2) and rose bengal/green light (522 nm) irradiation (5.4 J/cm2) in a single setting. The procedure was repeated twice due to persistent signs of inflammation and infection. After three combined same-session PACK-CXL treatments, the patient's cornea converted to a quiescent scar, and symptoms of ocular pain, photophobia, epiphora, and blepharospasm resolved. Confocal microscopy revealed no detectable Acanthamoeba cysts. The patient currently awaits penetrating keratoplasty. CONCLUSIONS The same-session combination of riboflavin/UV-A and rose bengal/green light PACK-CXL effectively treated a patient with confirmed AK that was resistant to conventional medical therapy, suggesting that using two chromophores in a single procedure may represent a future treatment alternative for AK.
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Affiliation(s)
- Farhad Hafezi
- ELZA Institute AG, Bahnhofstrasse 15, 8001, Zurich, Switzerland.
- Laboratory of Ocular Cell Biology, Center for Applied Biotechnology and Molecular Medicine, University of Zurich, Zurich, Switzerland.
- Faculty of Medicine, University of Geneva, Geneva, Switzerland.
- USC Roski Eye Institute, University of Southern California, Los Angeles, CA, USA.
- Department of Ophthalmology, University of Wenzhou, Wenzhou, China.
- Department of Ophthalmology, NYU Grossman School of Medicine, New York, NY, USA.
| | - Jürg Messerli
- Department of Ophthalmology, University Hospital Basel, Basel, Switzerland
| | - Emilio A Torres-Netto
- ELZA Institute AG, Bahnhofstrasse 15, 8001, Zurich, Switzerland
- Department of Ophthalmology, Paulista School of Medicine, Federal University of Sao Paulo, Sao Paulo, Brazil
| | - Nan-Ji Lu
- ELZA Institute AG, Bahnhofstrasse 15, 8001, Zurich, Switzerland
- School of Medicine and Health Sciences, University of Antwerp, Wilrijk, Belgium
| | - M Enes Aydemir
- ELZA Institute AG, Bahnhofstrasse 15, 8001, Zurich, Switzerland
| | - Nikki L Hafezi
- ELZA Institute AG, Bahnhofstrasse 15, 8001, Zurich, Switzerland
- School of Medicine and Health Sciences, University of Antwerp, Wilrijk, Belgium
| | - Mark Hillen
- ELZA Institute AG, Bahnhofstrasse 15, 8001, Zurich, Switzerland
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Prado-Costa B, Pinto LF, Fonseca MF, de Freitas D, Alvarenga LM. A Synthetic View on Acanthamoeba Keratitis Host Immune Response: Potential Factors Influencing the Development of Chronic Inflammation. Cornea 2025; 44:118-127. [PMID: 39627013 DOI: 10.1097/ico.0000000000003690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2024] [Accepted: 08/05/2024] [Indexed: 02/05/2025]
Abstract
PURPOSE The purpose of this study was to compile the current knowledge concerning Acanthamoeba keratitis (AK) host immune response to better understand the elements involved in the chronification of inflammation and worse disease outcomes. METHODS A scoping review of the literature on AK host immune response was written after a systematic literature search was performed on the PubMed, Latin American Caribbean Health Sciences Literature, Cochrane Library, Embase, Web of Science, and Scientific Electronic Library Online databases. Recovered articles were screened according to inclusion and exclusion criteria, and the selected studies were analyzed to compile the review. RESULTS The search strategy yielded a total of 768 articles from all searched databases. After the exclusion of duplicate records, 412 studies were screened according to inclusion and exclusion criteria. Finally, a total of 95 articles were selected to compile this review, of which 15 were included as additional bibliography. As for study type, 45 were experimental, 19 were observational, 23 were case reports, and 8 were reviews. CONCLUSIONS From the literature, both innate and adaptive immune systems seem to play an important role in AK control and resolution. On the other hand, there is also abundant evidence pointing out that the development of chronic and extracorneal inflammation is immune mediated and is influenced by several factors such as individual patient genetic variability, inadequate treatment, and Acanthamoeba strain pathogenicity.
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Affiliation(s)
- Bianca Prado-Costa
- Laboratório de Imunoquímica, Departamento de Patologia Básica, Universidade Federal do Paraná (UFPR), Curitiba, PR, Brazil ; and
| | - Larissa Fagundes Pinto
- Departamento de Oftalmologia e Ciências Visuais, Escola Paulista de Medicina, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil
| | - Mariana Fernandes Fonseca
- Laboratório de Imunoquímica, Departamento de Patologia Básica, Universidade Federal do Paraná (UFPR), Curitiba, PR, Brazil ; and
| | - Denise de Freitas
- Departamento de Oftalmologia e Ciências Visuais, Escola Paulista de Medicina, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil
| | - Larissa Magalhães Alvarenga
- Laboratório de Imunoquímica, Departamento de Patologia Básica, Universidade Federal do Paraná (UFPR), Curitiba, PR, Brazil ; and
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Linaburg TJ, Hammersmith KM. Contact Lens-Related Corneal Infections. Infect Dis Clin North Am 2024; 38:795-811. [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] [MESH Headings] [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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Loufouma-Mbouaka A, Andor A, Leitsch D, Pérez-Serrano J, Arnér ESJ, Walochnik J, Martín-Pérez T. Evaluating the amoeba thioredoxin reductase selenoprotein as potential drug target for treatment of Acanthamoeba infections. Int J Parasitol Drugs Drug Resist 2024; 26:100564. [PMID: 39326195 PMCID: PMC11459619 DOI: 10.1016/j.ijpddr.2024.100564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2024] [Revised: 09/05/2024] [Accepted: 09/12/2024] [Indexed: 09/28/2024]
Abstract
The genus Acanthamoeba comprises facultative pathogens, causing Acanthamoeba keratitis (AK) and granulomatous amoebic encephalitis (GAE). In both diseases, treatment options are limited, and drug development is challenging. This study aimed to investigate the role of the large thioredoxin reductase selenoprotein of Acanthamoeba (AcTrxR-L) as a potential drug target assessing the effects of the thioredoxin reductase inhibitors auranofin, TRi-1, and TRi-2 on AcTrxR-L activity and on the viability of Acanthamoeba trophozoites. Recombinant expression and purification of AcTrxR-L as a selenoprotein allowed assessments of its enzymatic activity, with reduction of various substrates, including different thioredoxin isoforms. Auranofin demonstrated potent inhibition towards AcTrxR-L, followed by TRi-1, and TRi-2 exhibiting lower effectiveness. The inhibitors showed variable activity against trophozoites in culture, with TRi-1 and TRi-2 resulting in strongly impaired trophozoite viability. Cytotoxicity tests with human corneal epithelial cells revealed lower susceptibility to all compounds compared to Acanthamoeba trophozoites, underscoring their potential as future amoebicidal agents. Altogether, this study highlights the druggability of AcTrxR-L and suggests it to be a promising drug target for the treatment of Acanthamoeba infections. Further research is warranted to elucidate the role of AcTrxR-L in Acanthamoeba pathogenesis and to develop effective therapeutic strategies targeting this redox enzyme.
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Affiliation(s)
- Alvie Loufouma-Mbouaka
- Institute of Specific Prophylaxis and Tropical Medicine, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, 1090, Vienna, Austria
| | - Attila Andor
- Department of Selenoprotein Research and the National Tumor Biology Laboratory, National Institute of Oncology, Budapest, Hungary; Division of Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - David Leitsch
- Institute of Specific Prophylaxis and Tropical Medicine, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, 1090, Vienna, Austria
| | - Jorge Pérez-Serrano
- Department of Biomedicine and Biotechnology, Faculty of Pharmacy, University of Alcalá, 28871, Alcalá de Henares, Spain
| | - Elias S J Arnér
- Department of Selenoprotein Research and the National Tumor Biology Laboratory, National Institute of Oncology, Budapest, Hungary; Division of Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Julia Walochnik
- Institute of Specific Prophylaxis and Tropical Medicine, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, 1090, Vienna, Austria
| | - Tania Martín-Pérez
- Institute of Specific Prophylaxis and Tropical Medicine, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, 1090, Vienna, Austria.
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9
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Seitzman GD, Keenan JD, Lietman TM, Ruder K, Zhong L, Chen C, Liu Y, Yu D, Abraham T, Hinterwirth A, Doan T. Human Conjunctival Transcriptome in Acanthamoeba Keratitis: An Exploratory Study. Cornea 2024; 43:1272-1277. [PMID: 38771726 PMCID: PMC11371541 DOI: 10.1097/ico.0000000000003545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 02/26/2024] [Indexed: 05/23/2024]
Abstract
PURPOSE The purpose of this study was to identify conjunctival transcriptome differences in patients with Acanthamoeba keratitis compared with keratitis with no known associated pathogen. METHODS The host conjunctival transcriptome of 9 patients with Acanthamoeba keratitis (AK) is compared with the host conjunctival transcriptome of 13 patients with pathogen-free keratitis. Culture and/or confocal confirmed Acanthamoeba in 8 of 9 participants with AK who underwent metagenomic RNA sequencing as the likely pathogen. Cultures were negative in all 13 cases where metagenomic RNA sequencing did not identify a pathogen. RESULTS Transcriptome analysis identified 36 genes differently expressed between patients with AK and patients with presumed sterile, or pathogen-free, keratitis. Gene enrichment analysis revealed that some of these genes participate in several biologic pathways important for cellular signaling, ion transport and homeostasis, glucose transport, and mitochondrial metabolism. Notable relatively differentially expressed genes with potential relevance to Acanthamoeba infection included CPS1 , SLC35B4 , STEAP2 , ATP2B2 , NMNAT3 , and AKAP12 . CONCLUSIONS This research suggests that the local transcriptome in Acanthamoeba keratitis may be sufficiently robust to be detected in the conjunctiva and that corneas infected with Acanthamoeba may be distinguished from the inflamed cornea where no pathogen was identified. Given the low sensitivity for corneal cultures, identification of differentially expressed genes may serve as a suggestive transcriptional signature allowing for a complementary diagnostic technique to identify this blinding parasite. Knowledge of differentially expressed genes may also direct investigation of disease pathophysiology and suggest novel pathways for therapeutic targets.
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Affiliation(s)
- Gerami D Seitzman
- Francis I. Proctor Foundation, University of California, San Francisco, California; and
- Department of Ophthalmology, University of California, San Francisco, California
| | - Jeremy D Keenan
- Francis I. Proctor Foundation, University of California, San Francisco, California; and
- Department of Ophthalmology, University of California, San Francisco, California
| | - Thomas M Lietman
- Francis I. Proctor Foundation, University of California, San Francisco, California; and
- Department of Ophthalmology, University of California, San Francisco, California
| | - Kevin Ruder
- Francis I. Proctor Foundation, University of California, San Francisco, California; and
| | - Lina Zhong
- Francis I. Proctor Foundation, University of California, San Francisco, California; and
| | - Cindi Chen
- Francis I. Proctor Foundation, University of California, San Francisco, California; and
| | - YuHeng Liu
- Francis I. Proctor Foundation, University of California, San Francisco, California; and
| | - Danny Yu
- Francis I. Proctor Foundation, University of California, San Francisco, California; and
| | - Thomas Abraham
- Francis I. Proctor Foundation, University of California, San Francisco, California; and
| | - Armin Hinterwirth
- Francis I. Proctor Foundation, University of California, San Francisco, California; and
| | - Thuy Doan
- Francis I. Proctor Foundation, University of California, San Francisco, California; and
- Department of Ophthalmology, University of California, San Francisco, California
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10
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Posarelli M, Passaro ML, Avolio FC, Costagliola C, Semeraro F, Romano V. The incidence of severe complications in acanthamoeba keratitis: Qualitative and quantitative systematic assessment. Surv Ophthalmol 2024; 69:769-778. [PMID: 38885760 DOI: 10.1016/j.survophthal.2024.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 06/04/2024] [Accepted: 06/06/2024] [Indexed: 06/20/2024]
Abstract
Acanthamoeba keratitis (AK) is a rare, sight-threating corneal infection. The disease is challenging to diagnose and treat, and the amoeba can rapidly encyst, persisting in the tissue and causing recurrences. Medical therapy is conventionally considered the first line treatment, but advanced cases could require more invasive treatments like a "chaud" corneal transplant. We review the incidence of severe complications in patients affected by AK. Of 439 reports screened, 158 met our inclusion criteria. Incidence of severe complications was low, with 2.21 % patients developing perforation, 1 % requiring evisceration/enucleation and less than 1 % developing endophthalmitis. Corneal transplantation was required in 16.68 % of the cases. According to our results, and considering the reported incidences of these complications in other infectious keratitis, AK patients have an overall low risk of developing perforation, endophthalmitis, and enucleation/evisceration. Nevertheless, data available in the literature remain poor, and further randomized control trials are needed to confirm our findings.
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Affiliation(s)
- Matteo Posarelli
- St. Paul's Eye Unit, Royal Liverpool University Hospital, Liverpool, UK; Ophthalmology Unit of the Department of Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy
| | - Maria Laura Passaro
- Department of Neurosciences, Reproductive Sciences and Dentistry, University of Naples "Federico II", Naples, Italy; Department of Medicine and Health Sciences "V. Tiberio", University of Molise, Campobasso, Italy
| | - Fabio Claudio Avolio
- Department of Neurosciences, Reproductive Sciences and Dentistry, University of Naples "Federico II", Naples, Italy
| | - Ciro Costagliola
- Department of Neurosciences, Reproductive Sciences and Dentistry, University of Naples "Federico II", Naples, Italy
| | - Francesco Semeraro
- Department of Medical and Surgical Specialties, Radiological Sciences, and Public Health, Ophthalmology Clinic, University of Brescia, Brescia, Italy; Eye Unit, ASST Spedali Civili di Brescia, Piazzale Spedali Civili, 1, 25123 Brescia, Italy
| | - Vito Romano
- Department of Medical and Surgical Specialties, Radiological Sciences, and Public Health, Ophthalmology Clinic, University of Brescia, Brescia, Italy; Eye Unit, ASST Spedali Civili di Brescia, Piazzale Spedali Civili, 1, 25123 Brescia, Italy; Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, UK.
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11
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Abu Dail Y, Flockerzi E, Munteanu C, Szentmáry N, Seitz B, Daas L. Rethinking Keratoplasty for Patients with Acanthamoeba Keratitis: Early "Low Load Keratoplasty" in Contrast to Late Optical and Therapeutic Keratoplasty. Microorganisms 2024; 12:1801. [PMID: 39338475 PMCID: PMC11434615 DOI: 10.3390/microorganisms12091801] [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: 04/07/2024] [Revised: 07/09/2024] [Accepted: 08/27/2024] [Indexed: 09/30/2024] Open
Abstract
BACKGROUND Early therapeutic penetrating keratoplasty (TKP) for Acanthamoeba keratitis (AK) is thought to have a worse visual prognosis than the delayed optical penetrating keratoplasty (OKP) after successful conservative treatment of AK. This has led to a tendency to prolong conservative therapy and delay penetrating keratoplasty in patients with AK. This retrospective series presents the results of patients with AK that underwent early penetrating keratoplasty after reducing the corneal amoeba load through intensive conservative therapy, so-called "low load keratoplasty" (LLKP). PATIENTS AND METHODS The medical records of our department were screened for patients with AK, confirmed by histological examination and/or PCR and/or in vivo confocal microscopy, which underwent ab LLKP and had a follow-up time of at least one year between 2009 and 2023. Demographic data, best corrected visual acuity (BCVA) and intraocular pressure at first and last visit, secondary glaucoma (SG), and recurrence and graft survival rates were assessed. RESULTS 28 eyes of 28 patients were included. The average time from initiation of therapy to penetrating keratoplasty (PKP) was 68 ± 113 days. The mean follow-up time after LLKP was 53 ± 42 months. BCVA (logMAR) improved from 1.9 ± 1 pre-operatively to 0.5 ± 0.6 at last visit (p < 0.001). A total of 14% of patients were under medical therapy for SG at the last visit, and two of them underwent glaucoma surgery. The recurrence rate was 4%. The Kaplan-Meier graft survival rate of the first graft at four years was 70%. The second graft survival rate at four years was 87.5%. CONCLUSION LLKP appears to achieve a good visual prognosis with an earlier visual and psychological habilitation, as well as low recurrence and SG rates. These results should encourage us to reconsider the optimal timing of PKP in therapy-resistant AK.
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Affiliation(s)
- Yaser Abu Dail
- Department of Ophthalmology, Saarland University Medical Center, Kirrberger Straße, Building 22, 66421 Homburg/Saar, Germany
| | - Elias Flockerzi
- Department of Ophthalmology, Saarland University Medical Center, Kirrberger Straße, Building 22, 66421 Homburg/Saar, Germany
| | - Cristian Munteanu
- Department of Ophthalmology, Saarland University Medical Center, Kirrberger Straße, Building 22, 66421 Homburg/Saar, Germany
| | - Nóra Szentmáry
- Dr. Rolf M. Schwiete Center for Limbal Stem Cell and Congenital Aniridia Research, Saarland University, 66421 Homburg/Saar, Germany
| | - Berthold Seitz
- Department of Ophthalmology, Saarland University Medical Center, Kirrberger Straße, Building 22, 66421 Homburg/Saar, Germany
| | - Loay Daas
- Department of Ophthalmology, Saarland University Medical Center, Kirrberger Straße, Building 22, 66421 Homburg/Saar, Germany
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12
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Asfaw T, Metaferia Y, Weldehanna EG, Weldehanna DG. Bacterial pathogens and antimicrobial susceptibility in ocular infections: A study at Boru-Meda General Hospital, Dessie, Ethiopia. BMC Ophthalmol 2024; 24:342. [PMID: 39138386 PMCID: PMC11323621 DOI: 10.1186/s12886-024-03544-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Accepted: 06/25/2024] [Indexed: 08/15/2024] Open
Abstract
INTRODUCTION The eye consists of both internal and external compartments. Several variables, including microbes, dust, and high temperatures can cause eye illnesses that can result in blindness. Bacterial eye infections continue to be a major cause of ocular morbidity and blindness, and their prevalence is periodically rising. The objective of the study was to detect bacterial pathogens and assess their susceptibility profiles to antibiotics in the ophthalmology unit of Boru-meda Hospital in Dessie, Ethiopia. METHODS A hospital-based cross-sectional study was conducted from February 1 to April 30, 2021, among 319 study participants with symptomatic ocular or peri-ocular infections who were enrolled using a consecutive sampling technique. After proper specimen collection, the specimen was immediately inoculated with chocolate, blood, and MacConkey agar. After pure colonies were obtained, they were identified using standard microbiological methods. The Kirby Bauer disk diffusion method was used to test antimicrobial susceptibility patterns, based on the guidelines of the Clinical and Laboratory Standards Institute. RESULTS The majority of participants developed conjunctivitis 126 (39.5%), followed by blepharitis 47 (14.73%), and dacryocystitis 45 (14.1%). Overall, 164 (51.4%) participants were culture positive, six (1.9%) participants had mixed bacterial isolates, giving a total of 170 bacterial isolates with an isolation rate of 53.3%. The predominant species was CoNS 47 (27.6%), followed by S. aureus 38 (22.4%) and Moraxella species 32 (18.8%). The overall Multi-Drug Resistance (MDR) rate was 62.9%, with 33 (44.6%) being gram-negative and 74 (77.1%) being gram-positive isolates. CONCLUSION Conjunctivitis was the dominant clinical case and CoNS, was the predominant isolate. A higher rate of MDR isolates, particularly gram-positive ones, was observed. Efficient peri-ocular or ocular bacterial infection surveillance, including microbiological laboratory data, is necessary for monitoring disease trends.
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Affiliation(s)
| | - Yeshi Metaferia
- Department of Medical Laboratory Science, College of Medicine and Health Sciences, Wollo University, P.O. Box 1145, Dessie, Ethiopia
| | | | - Daniel Gebretsadik Weldehanna
- Department of Medical Laboratory Science, College of Medicine and Health Sciences, Wollo University, P.O. Box 1145, Dessie, Ethiopia.
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13
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Blaser F, Bajka A, Grimm F, Metzler S, Herrmann D, Barthelmes D, Zweifel SA, Said S. Assessing PCR-Positive Acanthamoeba Keratitis-A Retrospective Chart Review. Microorganisms 2024; 12:1214. [PMID: 38930596 PMCID: PMC11205950 DOI: 10.3390/microorganisms12061214] [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: 05/20/2024] [Revised: 06/04/2024] [Accepted: 06/13/2024] [Indexed: 06/28/2024] Open
Abstract
Ophthalmologists' diagnostic and treatment competence in Acanthamoeba keratitis varies widely. This investigator-initiated, retrospective, single-center chart review examined the electronic patient files regarding PCR-positive Acanthamoeba keratitis. We included corneal and contact lens assessments. We further reviewed the patient's medical history, corneal scraping results regarding viral or fungal co-infections, and the duration from symptom onset to final diagnosis. We identified 59 eyes of 52 patients from February 2010 to February 2023, with 31 of 52 (59.6%) being female patients. The median (IQR, range) patient age was 33 (25.3 to 45.5 [13 to 90]) years, and the mean (SD, range) time to diagnosis after symptom onset was 18 (10.5 to 35 [3 to 70]) days. Overall, 7 of 52 (7.7%) patients displayed a bilateral Acanthamoeba infection, and 48 (92.3%) used contact lenses at symptom onset. Regarding other microbiological co-infections, we found virologic PCR testing in 45 of 52 (86.5%) patients, with 3 (6.7%) positive corneal scrapings. Fungal cultures were performed in 49 of 52 (94.2%) patients, with 5 (10.2%) positive corneal scrapings. The medical treatment success rate was 45/46 (97.8%). This study raises awareness of patient education in contact lens handling and screens for further microbial co-infections in suspected Acanthamoeba cases.
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Affiliation(s)
- Frank Blaser
- Department of Ophthalmology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland (S.S.)
| | - Anahita Bajka
- Department of Ophthalmology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland (S.S.)
| | - Felix Grimm
- Institute of Parasitology, University of Zurich, 8057 Zurich, Switzerland
| | - Simone Metzler
- Department of Ophthalmology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland (S.S.)
| | - Didier Herrmann
- Institute of Optometry, University of Applied Science, 4600 Olten, Switzerland
| | - Daniel Barthelmes
- Department of Ophthalmology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland (S.S.)
| | - Sandrine Anne Zweifel
- Department of Ophthalmology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland (S.S.)
| | - Sadiq Said
- Department of Ophthalmology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland (S.S.)
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14
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Yu M, Li W, He X, He G, Yao Y, Wang Y, Shao M, Xiong T, Xu H, Zhao J. Metabarcoding of protozoa and helminth in black-necked cranes: a high prevalence of parasites and free-living amoebae. Parasite 2024; 31:28. [PMID: 38819296 PMCID: PMC11141520 DOI: 10.1051/parasite/2024028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 05/04/2024] [Indexed: 06/01/2024] Open
Abstract
Parasites and free-living amoebae (FLA) are common pathogens that pose threats to wildlife and humans. The black-necked crane (Grus nigricollis) is a near-threatened species and there is a shortage of research on its parasite diversity. Our study aimed to use noninvasive methods to detect intestinal parasites and pathogenic FLA in G. nigricollis using high-throughput sequencing (HTS) based on the 18S rDNA V9 region. A total of 38 fresh fecal samples were collected in Dashanbao, China, during the overwintering period (early-, middle I-, middle II-, and late-winter). Based on the 18S data, eight genera of parasites were identified, including three protozoan parasites: Eimeria sp. (92.1%) was the dominant parasite, followed by Tetratrichomonas sp. (36.8%) and Theileria sp. (2.6%). Five genera of helminths were found: Echinostoma sp. (100%), Posthodiplostomum sp. (50.0%), Euryhelmis sp. (26.3%), Eucoleus sp. (50.0%), and Halomonhystera sp. (2.6%). Additionally, eight genera of FLA were detected, including the known pathogens Acanthamoeba spp. (n = 13) and Allovahlkampfia spp. (n = 3). Specific PCRs were used to further identify the species of some parasites and FLA. Furthermore, the 18S data indicated significant changes in the relative abundance and genus diversity of the protozoan parasites and FLA among the four periods. These results underscore the importance of long-term monitoring of pathogens in black-necked cranes to protect this near-endangered species.
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Affiliation(s)
- Mengshi Yu
- College of Agronomy and Life Sciences, Zhaotong University Zhaotong 657000 PR China
- College of Life Science, Sichuan Agricultural University Ya’an 625014 PR China
| | - Wenhao Li
- College of Agronomy and Life Sciences, Zhaotong University Zhaotong 657000 PR China
- College of Life Science, Sichuan Agricultural University Ya’an 625014 PR China
| | - Xin He
- Sichuan Academy of Grassland Sciences Chengdu 610000 PR China
| | - Guiwen He
- College of Agronomy and Life Sciences, Zhaotong University Zhaotong 657000 PR China
- Yunnan Key Laboratory of Gastrodia and Fungi Symbiotic Biology, Zhaotong University Zhaotong 657000 PR China
| | - Yonfang Yao
- College of Life Science, Sichuan Agricultural University Ya’an 625014 PR China
| | - Yuanjian Wang
- Management Bureau of Dashanbao Black-Necked Crane National Nature Reserve, Yunnan Province Zhaotong 657000 Yunnan PR China
| | - Mingcui Shao
- Management Bureau of Dashanbao Black-Necked Crane National Nature Reserve, Yunnan Province Zhaotong 657000 Yunnan PR China
| | - Tingsong Xiong
- Management Bureau of Dashanbao Black-Necked Crane National Nature Reserve, Yunnan Province Zhaotong 657000 Yunnan PR China
| | - Huailiang Xu
- College of Life Science, Sichuan Agricultural University Ya’an 625014 PR China
| | - Junsong Zhao
- College of Agronomy and Life Sciences, Zhaotong University Zhaotong 657000 PR China
- Yunnan Key Laboratory of Gastrodia and Fungi Symbiotic Biology, Zhaotong University Zhaotong 657000 PR China
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15
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Loufouma-Mbouaka A, Martín-Pérez T, Köhsler M, Danisman Z, Schwarz M, Mazumdar R, Samba-Louaka A, Walochnik J. Characterization of novel extracellular proteases produced by Acanthamoeba castellanii after contact with human corneal epithelial cells and their relevance to pathogenesis. Parasit Vectors 2024; 17:242. [PMID: 38812022 PMCID: PMC11137893 DOI: 10.1186/s13071-024-06304-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Accepted: 04/24/2024] [Indexed: 05/31/2024] Open
Abstract
BACKGROUND Proteases produced by Acanthamoeba spp. play an important role in their virulence and may be the key to understanding Acanthamoeba pathogenesis; thus, increasing attention has been directed towards these proteins. The present study aimed to investigate the lytic factors produced by Acanthamoeba castellanii during the first hours of in vitro co-culture with human corneal epithelial cells (HCECs). METHODS We used one old and one recent Acanthamoeba isolate, both from patients with severe keratitis, and subsets of these strains with enhanced pathogenic potential induced by sequential passaging over HCEC monolayers. The proteolytic profiles of all strains and substrains were examined using 1D in-gel zymography. RESULTS We observed the activity of additional proteases (ranging from 33 to 50 kDa) during the early interaction phase between amoebae and HCECs, which were only expressed for a short time. Based on their susceptibilities to protease inhibitors, these proteases were characterized as serine proteases. Protease activities showed a sharp decline after 4 h of co-incubation. Interestingly, the expression of Acanthamoeba mannose-binding protein did not differ between amoebae in monoculture and those in co-culture. Moreover, we observed the activation of matrix metalloproteinases in HCECs after contact with Acanthamoeba. CONCLUSIONS This study revealed the involvement of two novel serine proteases in Acanthamoeba pathogenesis and suggests a pivotal role of serine proteases during Acanthamoeba-host cell interaction, contributing to cell adhesion and lysis.
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Affiliation(s)
- Alvie Loufouma-Mbouaka
- Center for Pathophysiology, Infectiology and Immunology, Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Tania Martín-Pérez
- Center for Pathophysiology, Infectiology and Immunology, Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Martina Köhsler
- Center for Pathophysiology, Infectiology and Immunology, Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Zeynep Danisman
- Center for Pathophysiology, Infectiology and Immunology, Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Maya Schwarz
- Center for Pathophysiology, Infectiology and Immunology, Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Rounik Mazumdar
- Max Perutz Labs Vienna, Department of Medical Biochemistry, Medical University of Vienna, Vienna, Austria
- GenomeByte Ltd, London, UK
| | - Ascel Samba-Louaka
- Laboratoire Ecologie Et Biologie Des Interactions, Université de Poitiers, UMR CNRS, 7267, Poitiers, France
| | - Julia Walochnik
- Center for Pathophysiology, Infectiology and Immunology, Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria.
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16
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Kong CF, Go C, Goolam S, Yeung S. Diagnostic utility of in vivo confocal microscopy in Acanthamoeba keratitis following corneal crosslinking. BMJ Case Rep 2024; 17:e257279. [PMID: 38772872 DOI: 10.1136/bcr-2023-257279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2024] Open
Abstract
Acanthamoeba keratitis (AK) is a rare but potentially sight-threatening complication of corneal collagen crosslinking (CXL) for keratoconus. In this report, we describe an early adolescent male who underwent routine CXL for progressive keratoconus in his left eye. Preprocedural left visual acuity (VA) was 6/9. At day 5 postprocedure, multifocal corneal infiltrates were identified. Corneal scrape, bandage contact lens cultures and herpetic and Acanthamoeba PCR were negative. In vivo, confocal microscopy (IVCM) identified Acanthamoeba cysts within the corneal stroma. Intensive amoebicidal therapy was initiated, but recovery was complicated by significant inflammation, resulting in widespread aggressive corneal vascularisation necessitating topical steroids and steroid-sparing agents. At 10 months, his left VA was 6/24. This report emphasises the importance of maintaining a high index of suspicion for AK in cases of post-CXL microbial keratitis and highlights the diagnostic value of IVCM, particularly in culture-negative and PCR-negative cases.
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Affiliation(s)
- Cheng Fei Kong
- The University of Sydney Save Sight Institute, Sydney, New South Wales, Australia
- Westmead Hospital, Westmead, New South Wales, Australia
| | - Christopher Go
- The University of Sydney Save Sight Institute, Sydney, New South Wales, Australia
- Westmead Hospital, Westmead, New South Wales, Australia
| | - Saadiah Goolam
- The University of Sydney Save Sight Institute, Sydney, New South Wales, Australia
- Westmead Hospital, Westmead, New South Wales, Australia
| | - Season Yeung
- Westmead Hospital, Westmead, New South Wales, Australia
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17
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Mooney R, Giammarini E, Corbett E, Thomson S, McKinley K, Sinisterra Sebastian P, Rodgers K, O’Donnell J, McGinness C, Roberts CW, Ramaesh K, Henriquez FL. Sodium Metabisulfite Inhibits Acanthamoeba Trophozoite Growth through Thiamine Depletion. Pathogens 2024; 13:431. [PMID: 38921729 PMCID: PMC11206890 DOI: 10.3390/pathogens13060431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 05/13/2024] [Accepted: 05/19/2024] [Indexed: 06/27/2024] Open
Abstract
Acanthamoeba keratitis (AK) is a severe infection of the cornea. Prevention and treatment are difficult due to the inefficacy of currently available compounds. The impact of many commonly used compounds for routine examinations of Acanthamoeba is unexplored but might offer insight useful in combatting AK. In this study, we demonstrate that sodium metabisulfite, a common preservation constituent of eye care solutions, was found to be active against Acanthamoeba trophozoites at concentrations lower than that commonly found in eye drops (IC50 0.03 mg/mL). We demonstrate that sodium metabisulfite depletes thiamine from growth medium and that Acanthamoeba is a thiamine auxotroph, requiring thiamine salvage for growth. The inhibitory effects of sodium metabisulfite can be overcome by thiamine supplementation. These results are consistent with the lack of key enzymes for thiamine biosynthesis in the genome of Acanthamoeba, an area which might prove exploitable using new or existing compounds. Indeed, this study highlights sodium metabisulfite as a useful inhibitor of Acanthamoeba castellanii trophozoites in vitro and that it acts, at least in part, by limiting available thiamine.
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Affiliation(s)
- Ronnie Mooney
- School of Health and Life Sciences, University of the West of Scotland Lanarkshire, Glasgow G72 0LH, UK; (R.M.)
| | - Elisa Giammarini
- School of Health and Life Sciences, University of the West of Scotland Lanarkshire, Glasgow G72 0LH, UK; (R.M.)
| | - Erin Corbett
- School of Health and Life Sciences, University of the West of Scotland Lanarkshire, Glasgow G72 0LH, UK; (R.M.)
| | - Scott Thomson
- School of Health and Life Sciences, University of the West of Scotland Lanarkshire, Glasgow G72 0LH, UK; (R.M.)
| | - Kevin McKinley
- School of Health and Life Sciences, University of the West of Scotland Lanarkshire, Glasgow G72 0LH, UK; (R.M.)
| | - Paula Sinisterra Sebastian
- School of Health and Life Sciences, University of the West of Scotland Lanarkshire, Glasgow G72 0LH, UK; (R.M.)
| | - Kiri Rodgers
- School of Health and Life Sciences, University of the West of Scotland Lanarkshire, Glasgow G72 0LH, UK; (R.M.)
| | - Jana O’Donnell
- School of Health and Life Sciences, University of the West of Scotland Lanarkshire, Glasgow G72 0LH, UK; (R.M.)
| | - Charles McGinness
- School of Computing, Engineering and Physical Sciences, University of the West of Scotland Paisley, Glasgow PA1 2BE, UK
| | - Craig W. Roberts
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow G4 0RE, UK
| | - Kanna Ramaesh
- NHS Greater Glasgow and Clyde, Gartnavel Hospital, Department of Ophthalmology, Glasgow G12 0YN, UK
| | - Fiona L. Henriquez
- School of Health and Life Sciences, University of the West of Scotland Lanarkshire, Glasgow G72 0LH, UK; (R.M.)
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18
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Petrillo F, Tortori A, Vallino V, Galdiero M, Fea AM, De Sanctis U, Reibaldi M. Understanding Acanthamoeba Keratitis: An In-Depth Review of a Sight-Threatening Eye Infection. Microorganisms 2024; 12:758. [PMID: 38674702 PMCID: PMC11052265 DOI: 10.3390/microorganisms12040758] [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: 03/13/2024] [Revised: 04/02/2024] [Accepted: 04/04/2024] [Indexed: 04/28/2024] Open
Abstract
Acanthamoeba keratitis (AK) is a rare but potentially sight-threatening corneal infection caused by the Acanthamoeba parasite. This microorganism is found ubiquitously in the environment, often in freshwater, soil, and other sources of moisture. Despite its low incidence, AK presents significant challenges due to delayed diagnosis and the complex nature of therapeutic management. Early recognition is crucial to prevent severe ocular complications, including corneal ulceration and vision loss. Diagnostic modalities and treatment strategies may vary greatly depending on the clinical manifestation and the available tools. With the growing reported cases of Acanthamoeba keratitis, it is essential for the ophthalmic community to thoroughly understand this condition for its effective management and improved outcomes. This review provides a comprehensive overview of AK, encompassing its epidemiology, risk factors, pathophysiology, clinical manifestations, diagnosis, and treatment.
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Affiliation(s)
- Francesco Petrillo
- Department of Surgical Sciences, University of Turin, 10126 Turin, Italy; (V.V.); (A.M.F.); (U.D.S.); (M.R.)
- Department of Ophthalmology, “City of Health and Science” Hospital, 10126 Turin, Italy
| | - Antonia Tortori
- Ophthalmology Unit, Surgery Department, Piacenza Hospital, 29121 Piacenza, Italy;
| | - Veronica Vallino
- Department of Surgical Sciences, University of Turin, 10126 Turin, Italy; (V.V.); (A.M.F.); (U.D.S.); (M.R.)
- Department of Ophthalmology, “City of Health and Science” Hospital, 10126 Turin, Italy
| | - Marilena Galdiero
- Department of Experimental Medicine, University of Campania “Luigi Vanvitelli”, 81100 Naples, Italy;
| | - Antonio M. Fea
- Department of Surgical Sciences, University of Turin, 10126 Turin, Italy; (V.V.); (A.M.F.); (U.D.S.); (M.R.)
- Department of Ophthalmology, “City of Health and Science” Hospital, 10126 Turin, Italy
| | - Ugo De Sanctis
- Department of Surgical Sciences, University of Turin, 10126 Turin, Italy; (V.V.); (A.M.F.); (U.D.S.); (M.R.)
- Department of Ophthalmology, “City of Health and Science” Hospital, 10126 Turin, Italy
| | - Michele Reibaldi
- Department of Surgical Sciences, University of Turin, 10126 Turin, Italy; (V.V.); (A.M.F.); (U.D.S.); (M.R.)
- Department of Ophthalmology, “City of Health and Science” Hospital, 10126 Turin, Italy
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19
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Jasim H, Grzeda M, Foot B, Tole D, Hoffman JJ. Incidence of Acanthamoeba Keratitis in the United Kingdom in 2015: A Prospective National Survey. Cornea 2024; 43:269-276. [PMID: 38097200 DOI: 10.1097/ico.0000000000003445] [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: 10/11/2022] [Accepted: 11/01/2023] [Indexed: 02/06/2024]
Abstract
PURPOSE The aims of this study were to quantify the incidence of Acanthamoeba keratitis (AK) in the United Kingdom and investigate risk factors and management parameters. METHODS This was a prospective population-based study from January to December 2015 through the British Ophthalmic Surveillance Unit. Data were collected on demographics, clinical features, and management. Incidence rates were calculated from estimates of population and contact lens (CL) user numbers. Statistical analysis compared annualized incidences per million and altered risk ratios for AK with the England and Wales 24 months 1997/1998 to 1998/1999 study. RESULTS The study identified 124 AK cases, an overall incidence of 2.35 per million. CL wearers accounted for 108 of 124 cases (87%), in whom the AK incidence was 26.94 per million. Herpes keratitis was initially misdiagnosed in 25 of 124 cases (20.2%). The highest incidence of AK was among planned replacement soft CL (PRSCL) wearers (50.65 per million), 7-fold greater than for daily disposable CL (DDSCL) users (7.24 per million). There was a significant increase in AK incidence ( P < 0.001) compared with both 1997/1998 [risk ratio 1.92, 95% confidence interval (CI) 1.38-2.66] and 1998/1999 (risk ratio 2.13, 95% CI 1.52-2.98) together with a higher incidence per million CL users of 26.94 versus 21.14 (1997/1998) and 17.53 (1998/1999). CONCLUSIONS This study provides the first published data on the nationwide incidence of AK in the United Kingdom. The findings confirm an increasing incidence of AK, particularly among contact lens wearers since 1997/1998 to 1998/1999. PRSCLs were identified as a significant risk factor compared with DDSCLs. Misdiagnosis and treatment delays remain an ongoing problem for patients with AK.
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Affiliation(s)
- Haneen Jasim
- Corneal and External Eye Service, Bristol Eye Hospital, Bristol, United Kingdom
| | - Mariusz Grzeda
- Corneal and External Eye Service, Bristol Eye Hospital, Bristol, United Kingdom
- School of Biomedical Engineering and Imaging Sciences, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom
| | - Barny Foot
- Royal College of Ophthalmologists, London, United Kingdom
| | - Derek Tole
- Corneal and External Eye Service, Bristol Eye Hospital, Bristol, United Kingdom
| | - Jeremy J Hoffman
- Corneal and External Disease Service, Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom; and
- International Centre for Eye Health, London School of Hygiene and Tropical Medicine, London, United Kingdom
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20
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Dart JKG, Papa V, Rama P, Knutsson KA, Ahmad S, Hau S, Sanchez S, Franch A, Birattari F, Leon P, Fasolo A, Kominek EM, Jadczyk-Sorek K, Carley F, Hossain P, Minassian DC. The Orphan Drug for Acanthamoeba Keratitis (ODAK) Trial: PHMB 0.08% (Polihexanide) and Placebo versus PHMB 0.02% and Propamidine 0.1. Ophthalmology 2024; 131:277-287. [PMID: 37802392 DOI: 10.1016/j.ophtha.2023.09.031] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 09/22/2023] [Accepted: 09/27/2023] [Indexed: 10/10/2023] Open
Abstract
PURPOSE To compare topical PHMB (polihexanide) 0.02% (0.2 mg/ml)+ propamidine 0.1% (1 mg/ml) with PHMB 0.08% (0.8 mg/ml)+ placebo (PHMB 0.08%) for Acanthamoeba keratitis (AK) treatment. DESIGN Prospective, randomized, double-masked, active-controlled, multicenter phase 3 study (ClinicalTrials.gov identifier, NCT03274895). PARTICIPANTS One hundred thirty-five patients treated at 6 European centers. METHODS Principal inclusion criteria were 12 years of age or older and in vivo confocal microscopy with clinical findings consistent with AK. Also included were participants with concurrent bacterial keratitis who were using topical steroids and antiviral and antifungal drugs before randomization. Principal exclusion criteria were concurrent herpes or fungal keratitis and use of antiamebic therapy (AAT). Patients were randomized 1:1 using a computer-generated block size of 4. This was a superiority trial having a predefined noninferiority margin. The sample size of 130 participants gave approximately 80% power to detect 20-percentage point superiority for PHMB 0.08% for the primary outcome of the medical cure rate (MCR; without surgery or change of AAT) within 12 months, cure defined by clinical criteria 90 days after discontinuing anti-inflammatory agents and AAT. A prespecified multivariable analysis adjusted for baseline imbalances in risk factors affecting outcomes. MAIN OUTCOME MEASURES The main outcome measure was MCR within 12 months, with secondary outcomes including best-corrected visual acuity and treatment failure rates. Safety outcomes included adverse event rates. RESULTS One hundred thirty-five participants were randomized, providing 127 in the full-analysis subset (61 receiving PHMB 0.02%+ propamidine and 66 receiving PHMB 0.08%) and 134 in the safety analysis subset. The adjusted MCR within 12 months was 86.6% (unadjusted, 88.5%) for PHMB 0.02%+ propamidine and 86.7% (unadjusted, 84.9%) for PHMB 0.08%; the noninferiority requirement for PHMB 0.08% was met (adjusted difference, 0.1 percentage points; lower one-sided 95% confidence limit, -8.3 percentage points). Secondary outcomes were similar for both treatments and were not analyzed statistically: median best-corrected visual acuity of 20/20 and an overall treatment failure rate of 17 of 127 patients (13.4%), of whom 8 of 127 patients (6.3%) required therapeutic keratoplasty. No serious drug-related adverse events occurred. CONCLUSIONS PHMB 0.08% monotherapy may be as effective (or at worse only 8 percentage points less effective) as dual therapy with PHMB 0.02%+ propamidine (a widely used therapy) with medical cure rates of more than 86%, when used with the trial treatment delivery protocol in populations with AK with similar disease severity. FINANCIAL DISCLOSURE(S) Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
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Affiliation(s)
- John K G Dart
- Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom; National Institute of Health Research, Moorfields Biomedical Research Centre, London, United Kingdom
| | | | - Paolo Rama
- Cornea and Ocular Surface Unit, San Raffaele Scientific Institute, Milan, Italy
| | | | - Saj Ahmad
- Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom; National Institute of Health Research, Moorfields Biomedical Research Centre, London, United Kingdom
| | - Scott Hau
- Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom; National Institute of Health Research, Moorfields Biomedical Research Centre, London, United Kingdom
| | - Sara Sanchez
- Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom
| | | | | | - Pia Leon
- Ophthalmic Unit, Ospedale SS Giovanni e Paolo, Venice, Italy
| | - Adriano Fasolo
- Research Unit, The Veneto Eye Bank Foundation, Venice, Italy
| | - Ewa Mrukwa Kominek
- Professor K. Gibiński University Clinical Center of Medical University of Silesia in Katowice, Katowice, Poland; Department of Ophthalmology, Faculty of Medical Sciences in Katowice, Medical University of Silesia in Katowice, Katowice, Poland
| | - Katarzyna Jadczyk-Sorek
- Professor K. Gibiński University Clinical Center of Medical University of Silesia in Katowice, Katowice, Poland; Department of Ophthalmology, Faculty of Medical Sciences in Katowice, Medical University of Silesia in Katowice, Katowice, Poland
| | - Fiona Carley
- Manchester Royal Eye Hospital, Manchester, United Kingdom
| | - Parwez Hossain
- Clinical Experimental Sciences, Faculty of Medicine, University of Southampton & University Hospitals Southampton NHS Trust, Southampton, United Kingdom; National Institute of Health Research (NIHR), Southampton Clinical Research Facility, Southampton, United Kingdom
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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] [MESH Headings] [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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22
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Pang J, Wei Z, Wang L, Guo X, Chen Q, Wei Y, Peng Y, Zhang Z, Zhang Y, Liu J, Cheng Z, Wang Z, Zhang Y, Chen K, Xu X, Lu X, Liang Q. Acanthamoeba Keratitis in China: Genotypic and Clinical Correlations. Transl Vis Sci Technol 2024; 13:5. [PMID: 38329750 PMCID: PMC10860683 DOI: 10.1167/tvst.13.2.5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 12/31/2023] [Indexed: 02/09/2024] Open
Abstract
Purpose To investigate the relationship between Acanthamoeba genotypes, clinical manifestations, and outcomes in Acanthamoeba keratitis (AK) patients. Methods This retrospective study included 159 culture-confirmed AK patients. Patients' data were collected, including demographics, initial diagnosis, treatments, and clinical features. The genotype of Acanthamoeba was identified through sequencing the Diagnostic Fragment 3 (DF3) region in the small ribosomal subunit RNA genes. The phylogenetic tree was constructed using the ClustalW model and maximum likelihood method. Cases with "poor outcome" were defined based on specific clinical criteria, including corneal perforation, keratoplasty, other eye surgery, duration of anti-amoebic therapy ≥8.0 months, and final visual acuity ≤20/80. "Better outcome" cases were the remainder. The correlation between T4 subtypes, clinical phenotypes, and clinical prognosis were further analyzed. Results In this study, AK was primarily attributed to the T4A genotype, with a positive correlation between geographical and genetic distances. The primary clinical associated with T4 subtypes was deep stromal infiltration. Results was also showed a significant association between T4 subtypes and clinical outcomes (P = 0.021). Further analysis revealed that T4C was closely associated with a better prognosis (P = 0.040) and T4D with worse outcomes (P = 0.013). Conclusions In China, AK was predominantly caused by the T4A subtype. Geographical distance positively correlated with genetic distance. Clinical prognosis varied among different subtypes, notably in T4C and T4D. Translational Relevance This study demonstrated the association between T4 subtypes and clinical phenotypes, as well as the effects of T4 subtypes on clinical prognosis.
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Affiliation(s)
- Jinding Pang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Zhenyu Wei
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Leying Wang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Xiaoyan Guo
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Qiankun Chen
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Yuan Wei
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Yan Peng
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Zijun Zhang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Yuheng Zhang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Jiamin Liu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Zhen Cheng
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Zhiqun Wang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Yang Zhang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Kexin Chen
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Xizhan Xu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Xinxin Lu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Qingfeng Liang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
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23
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Curro-Tafili K, Verbraak FD, de Vries R, van Nispen RMA, Ghyczy EAE. Diagnosing and monitoring the characteristics of Acanthamoeba keratitis using slit scanning and laser scanning in vivo confocal microscopy. Ophthalmic Physiol Opt 2024; 44:131-152. [PMID: 37916883 DOI: 10.1111/opo.13238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 09/09/2023] [Accepted: 09/23/2023] [Indexed: 11/03/2023]
Abstract
INTRODUCTION Acanthamoeba keratitis (AK) is a serious and potentially blinding ocular infection caused by the free-living amoeba, Acanthamoeba. In vivo confocal microscopy (IVCM) is a non-invasive device which has been proven of great use to diagnose Acanthamoeba infections immediately. The aim of this review was to establish different patterns and signs of AK that appear on the IVCM both before and after treatment. METHODS A systematic review of the literature from 1974 until September 2021 was performed using Embase and PubMed, following The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. RESULTS Twenty different signs of AK were observed using IVCM. The included studies used vastly different criteria to diagnose infections, ranging from just 1 to 13 of the signs, demonstrating the current lack of a standardised diagnosis of this infection using the IVCM. The appearance of double wall cysts, trophozoites, signet rings, target signs and clusters were shown to be pathognomonic to AK infections. Bright spots located in the corneal epithelium were demonstrated as non-reliable predictors of AK. The presence of cysts in clusters and single file can predict the need for corneal transplantation. The morphological changes in cysts using the IVCM following treatment were described as breaking down to hollow forms and occasionally surrounded by black cavities. Using this information, a visual guideline for identifying AK signs in diagnosis and follow-up using IVCM was created. CONCLUSION Increased awareness of the different signs and patterns of AK that appear on the IVCM is crucial in order to correctly identify an infection and increase the potential of this device. Our guidelines presented here can be used, but further studies are needed in order to determine the relationship and aetiology of these signs and cellular changes on the IVCM both before and after anti-amoeba treatment.
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Affiliation(s)
- K Curro-Tafili
- Department of Ophthalmology, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
- Amsterdam Public Health Research Institute, Quality of Care, Amsterdam, the Netherlands
| | - F D Verbraak
- Department of Ophthalmology, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - R de Vries
- Medical Library, Vrije Universiteit, Amsterdam, the Netherlands
| | - R M A van Nispen
- Department of Ophthalmology, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
- Amsterdam Public Health Research Institute, Quality of Care, Amsterdam, the Netherlands
| | - E A E Ghyczy
- Department of Ophthalmology, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
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24
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Rayamajhee B, Willcox M, Sharma S, Mooney R, Petsoglou C, Badenoch PR, Sherchan S, Henriquez FL, Carnt N. Zooming in on the intracellular microbiome composition of bacterivorous Acanthamoeba isolates. ISME COMMUNICATIONS 2024; 4:ycae016. [PMID: 38500701 PMCID: PMC10945361 DOI: 10.1093/ismeco/ycae016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 11/29/2023] [Accepted: 01/22/2024] [Indexed: 03/20/2024]
Abstract
Acanthamoeba, a free-living amoeba in water and soil, is an emerging pathogen causing severe eye infection known as Acanthamoeba keratitis. In its natural environment, Acanthamoeba performs a dual function as an environmental heterotrophic predator and host for a range of microorganisms that resist digestion. Our objective was to characterize the intracellular microorganisms of phylogenetically distinct Acanthamoeba spp. isolated in Australia and India through directly sequencing 16S rRNA amplicons from the amoebae. The presence of intracellular bacteria was further confirmed by in situ hybridization and electron microscopy. Among the 51 isolates assessed, 41% harboured intracellular bacteria which were clustered into four major phyla: Pseudomonadota (previously known as Proteobacteria), Bacteroidota (previously known as Bacteroidetes), Actinomycetota (previously known as Actinobacteria), and Bacillota (previously known as Firmicutes). The linear discriminate analysis effect size analysis identified distinct microbial abundance patterns among the sample types; Pseudomonas species was abundant in Australian corneal isolates (P < 0.007), Enterobacteriales showed higher abundance in Indian corneal isolates (P < 0.017), and Bacteroidota was abundant in Australian water isolates (P < 0.019). The bacterial beta diversity of Acanthamoeba isolates from keratitis patients in India and Australia significantly differed (P < 0.05), while alpha diversity did not vary based on the country of origin or source of isolation (P > 0.05). More diverse intracellular bacteria were identified in water isolates as compared with clinical isolates. Confocal and electron microscopy confirmed the bacterial cells undergoing binary fission within the amoebal host, indicating the presence of viable bacteria. This study sheds light on the possibility of a sympatric lifestyle within Acanthamoeba, thereby emphasizing its crucial role as a bunker and carrier of potential human pathogens.
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Affiliation(s)
- Binod Rayamajhee
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, NSW 2052, Australia
| | - Mark Willcox
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, NSW 2052, Australia
| | - Savitri Sharma
- Jhaveri Microbiology Centre, Prof Brien Holden Eye Research Centre, Hyderabad Eye Research Foundation, L. V. Prasad Eye Institute (LVPEI), Hyderabad, 500034, India
| | - Ronnie Mooney
- School of Health and Life Sciences, University of the West of Scotland, Blantyre, PA1 2BE, United Kingdom
| | - Constantinos Petsoglou
- Sydney and Sydney Eye Hospital, South-Eastern Sydney Local Health District, Sydney, NSW 2000, Australia
- Save Sight Institute, University of Sydney, Sydney, NSW 2000, Australia
| | - Paul R Badenoch
- College of Medicine and Public Health, Flinders University, Adelaide, 5042, Australia
| | - Samendra Sherchan
- School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA 70112, United States
| | - Fiona L Henriquez
- School of Health and Life Sciences, University of the West of Scotland, Blantyre, PA1 2BE, United Kingdom
| | - Nicole Carnt
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, NSW 2052, Australia
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25
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Rayamajhee B, Willcox M, Henriquez FL, Vijay AK, Petsoglou C, Shrestha GS, Peguda HK, Carnt N. The role of naturally acquired intracellular Pseudomonas aeruginosa in the development of Acanthamoeba keratitis in an animal model. PLoS Negl Trop Dis 2024; 18:e0011878. [PMID: 38166139 PMCID: PMC10795995 DOI: 10.1371/journal.pntd.0011878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 01/18/2024] [Accepted: 12/21/2023] [Indexed: 01/04/2024] Open
Abstract
BACKGROUND Acanthamoeba is an environmental host for various microorganisms. Acanthamoeba is also becoming an increasingly important pathogen as a cause of keratitis. In Acanthamoeba keratitis (AK), coinfections involving pathogenic bacteria have been reported, potentially attributed to the carriage of microbes by Acanthamoeba. This study assessed the presence of intracellular bacteria in Acanthamoeba species recovered from domestic tap water and corneas of two different AK patients and examined the impact of naturally occurring intracellular bacteria within Acanthamoeba on the severity of corneal infections in rats. METHODOLOGY/PRINCIPAL FINDINGS Household water and corneal swabs were collected from AK patients. Acanthamoeba strains and genotypes were confirmed by sequencing. Acanthamoeba isolates were assessed for the presence of intracellular bacteria using sequencing, fluorescence in situ hybridization (FISH), and electron microscopy. The viability of the bacteria in Acanthamoeba was assessed by labelling with alkyne-functionalized D-alanine (alkDala). Primary human macrophages were used to compare the intracellular survival and replication of the endosymbiotic Pseudomonas aeruginosa and a wild type strain. Eyes of rats were challenged intrastromally with Acanthamoeba containing or devoid of P. aeruginosa and evaluated for the clinical response. Domestic water and corneal swabs were positive for Acanthamoeba. Both strains belonged to genotype T4F. One of the Acanthamoeba isolates harboured P. aeruginosa which was seen throughout the Acanthamoeba's cytoplasm. It was metabolically active and could be seen undergoing binary fission. This motile strain was able to replicate in macrophage to a greater degree than strain PAO1 (p<0.05). Inoculation of Acanthamoeba containing the intracellular P. aeruginosa in rats eyes resulted in a severe keratitis with increased neutrophil response. Acanthamoeba alone induced milder keratitis. CONCLUSIONS/SIGNIFICANCE Our findings indicate the presence of live intracellular bacteria in Acanthamoeba can increase the severity of acute keratitis in vivo. As P. aeruginosa is a common cause of keratitis, this may indicate the potential for these intracellular bacteria in Acanthamoeba to lead to severe polymicrobial keratitis.
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Affiliation(s)
- Binod Rayamajhee
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
| | - Mark Willcox
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
| | - Fiona L. Henriquez
- School of Health and Life Sciences, University of the West of Scotland, Blantyre, Scotland, United Kingdom
| | - Ajay Kumar Vijay
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
| | - Constantinos Petsoglou
- Sydney and Sydney Eye Hospital, Southeastern Sydney Local Health District, Sydney, Australia
- Save Sight Institute, University of Sydney, Sydney, Australia
| | - Gauri Shankar Shrestha
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
| | - Hari Kumar Peguda
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
| | - Nicole Carnt
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
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26
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Shareef O, Shareef S, Saeed HN. New Frontiers in Acanthamoeba Keratitis Diagnosis and Management. BIOLOGY 2023; 12:1489. [PMID: 38132315 PMCID: PMC10740828 DOI: 10.3390/biology12121489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 12/01/2023] [Accepted: 12/01/2023] [Indexed: 12/23/2023]
Abstract
Acanthamoeba Keratitis (AK) is a severe corneal infection caused by the Acanthamoeba species of protozoa, potentially leading to permanent vision loss. AK requires prompt diagnosis and treatment to mitigate vision impairment. Diagnosing AK is challenging due to overlapping symptoms with other corneal infections, and treatment is made complicated by the organism's dual forms and increasing virulence, and delayed diagnosis. In this review, new approaches in AK diagnostics and treatment within the last 5 years are discussed. The English-language literature on PubMed was reviewed using the search terms "Acanthamoeba keratitis" and "diagnosis" or "treatment" and focused on studies published between 2018 and 2023. Two hundred sixty-five publications were initially identified, of which eighty-seven met inclusion and exclusion criteria. This review highlights the findings of these studies. Notably, advances in PCR-based diagnostics may be clinically implemented in the near future, while antibody-based and machine-learning approaches hold promise for the future. Single-drug topical therapy (0.08% PHMB) may improve drug access and efficacy, while oral medication (i.e., miltefosine) may offer a treatment option for patients with recalcitrant disease.
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Affiliation(s)
- Omar Shareef
- School of Engineering and Applied Sciences, Harvard College, Cambridge, MA 02138, USA;
| | - Sana Shareef
- Department of Bioethics, Columbia University, New York, NY 10027, USA
| | - Hajirah N. Saeed
- Department of Ophthalmology, University of Illinois Chicago, Chicago, IL 60607, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA 02115, USA
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27
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Mobeen R, Stapleton F, Chao C, Huynh MC, Phoebe Wong YS, Naduvilath T, Golebiowski B. Epithelial Immune Cell Response to Initial Soft Contact Lens Wear in the Human Corneal and Conjunctival Epithelium. Invest Ophthalmol Vis Sci 2023; 64:18. [PMID: 38099736 PMCID: PMC10729840 DOI: 10.1167/iovs.64.15.18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 11/19/2023] [Indexed: 12/18/2023] Open
Abstract
Purpose The purpose of this study was to assess the immediate ocular immune response to soft contact lens (CL) wear by examining presumed epithelial immune cell (EIC) density and morphology at the central, peripheral, limbal cornea, and conjunctiva. Methods Fifty-four participants naïve to CL wear (mean age = 24.8 ± 9.8 years, 44% female participants), were examined using in vivo confocal microscopy at baseline and after 2 hours of CL wear (1-Day ACUVUE MOIST). Images were captured at the central, temporal far peripheral and limbal cornea, and bulbar conjunctiva. EIC density was counted manually and morphology was graded. Differences in EIC parameters pre- and post-CL wear were examined using a generalized estimating equation model with appropriate post hoc analyses. Results After 2 hours of soft CL wear, there was a significant increase in EIC density in all regions other than the central cornea (all P < 0.001). Cell body size was significantly larger, and a higher proportion of participants exhibited EIC with long dendrites after lens wear at the central and peripheral cornea (both P < 0.001). There was a significant increase in the number of participants displaying EIC with thick dendrites at the peripheral (P = 0.04) and limbal cornea (P < 0.001) after lens wear. Conclusions EICs were primarily recruited to the peripheral regions, whereas the central cornea shows no significant recruitment after short-term CL wear. Both central and peripheral corneas exhibited an enhanced antigen capture capacity, whereas migratory capacity was increased in the peripheral corneal regions suggesting EIC activation following a short period of CL wear.
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Affiliation(s)
- Rabia Mobeen
- School of Optometry and Vision Science, University of New South Wales, New South Wales, Sydney, Australia
| | - Fiona Stapleton
- School of Optometry and Vision Science, University of New South Wales, New South Wales, Sydney, Australia
| | - Cecilia Chao
- School of Optometry and Vision Science, University of New South Wales, New South Wales, Sydney, Australia
| | - Mandy C. Huynh
- School of Optometry and Vision Science, University of New South Wales, New South Wales, Sydney, Australia
| | - Yee S. Phoebe Wong
- School of Optometry and Vision Science, University of New South Wales, New South Wales, Sydney, Australia
| | - Thomas Naduvilath
- School of Optometry and Vision Science, University of New South Wales, New South Wales, Sydney, Australia
- Brien Holden Vision Institute, University of New South Wales, New South Wales, Sydney, Australia
| | - Blanka Golebiowski
- School of Optometry and Vision Science, University of New South Wales, New South Wales, Sydney, Australia
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Rayamajhee B, Williams NLR, Siboni N, Rodgers K, Willcox M, Henriquez FL, Seymour JR, Potts J, Johnson C, Scanes P, Carnt N. Identification and quantification of Acanthamoeba spp. within seawater at four coastal lagoons on the east coast of Australia. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 901:165862. [PMID: 37541500 DOI: 10.1016/j.scitotenv.2023.165862] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 07/08/2023] [Accepted: 07/26/2023] [Indexed: 08/06/2023]
Abstract
Acanthamoeba is an opportunistic free-living heterotrophic protist that is the most predominant amoeba in diverse ecological habitats. Acanthamoeba causes amoebic keratitis (AK), a painful and potentially blinding corneal infection. Major risk factors for AK have been linked to non-optimal contact lens hygiene practices and Acanthamoeba contamination of domestic and recreational water. This study investigated the incidence and seasonal variation of Acanthamoeba spp. within coastal lagoons located on the eastern coast of Australia and then examined the association between Acanthamoeba and water abiotic factors and bacterial species within the water. Water samples were collected from four intermittently closed and open lagoons (ICOLLs) (Wamberal, Terrigal, Avoca and Cockrone) every month between August 2019 to July 2020 except March and April. qPCR was used to target the Acanthamoeba 18S rRNA gene, validated by Sanger sequencing. Water abiotic factors were measured in situ using a multiprobe metre and 16S rRNA sequencing (V3-V4) was performed to characterise bacterial community composition. Network analysis was used to gauge putative associations between Acanthamoeba incidence and bacterial amplicon sequence variants (ASVs). Among 206 water samples analysed, 79 (38.3%) were Acanthamoeba positive and Acanthamoeba level was significantly higher in summer compared with winter, spring, or autumn (p = 0.008). More than 50% (23/45) water samples of Terrigal were positive for Acanthamoeba which is a highly urbanised area with extensive recreational activities while about 32% (16/49) samples were positive from Cockrone that is the least impacted lagoon by urban development. All sequenced strains belonged to the pathogenic genotype T4 clade except two which were of genotype clades T2 and T5. Water turbidity, temperature, intl1 gene concentration, and dissolved O2 were significantly associated with Acanthamoeba incidence (p < 0.05). The ASVs level of cyanobacteria, Pseudomonas spp., Candidatus spp., and marine bacteria of the Actinobacteria phylum and Acanthamoeba 18S rRNA genes were positively correlated (Pearson's r ≥ 0.14). The presence of Acanthamoeba spp. in all lagoons, except Wamberal, was associated with significant differences in the composition of bacterial communities (beta diversity). The results of this study suggest that coastal lagoons, particularly those in urbanised regions with extensive water recreational activities, may pose an elevated risk to human health due to the relatively high incidence of pathogenic Acanthamoeba in the summer. These findings underscore the importance of educating the public about the rare yet devastating impact of AK on vision and quality of life, highlighting the need for collaborative efforts between public health officials and educators to promote awareness and preventive measures, especially focusing lagoons residents and travellers.
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Affiliation(s)
- Binod Rayamajhee
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia.
| | - Nathan L R Williams
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Sydney, Australia
| | - Nachshon Siboni
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Sydney, Australia
| | - Kiri Rodgers
- Institute of Biomedical and Environmental Health Research, School of Health and Life Sciences, University of the West of Scotland, Blantyre, South Lanarkshire, G72 0LH, Scotland, UK
| | - Mark Willcox
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
| | - Fiona L Henriquez
- Institute of Biomedical and Environmental Health Research, School of Health and Life Sciences, University of the West of Scotland, Blantyre, South Lanarkshire, G72 0LH, Scotland, UK
| | - Justin R Seymour
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Sydney, Australia
| | - Jaimie Potts
- Estuaries and Catchments Team, Waters Wetland Coastal Science Branch, NSW Department of Planning, Industry and Environment, Lidcombe, NSW 2141, Australia
| | - Colin Johnson
- Estuaries and Catchments Team, Waters Wetland Coastal Science Branch, NSW Department of Planning, Industry and Environment, Lidcombe, NSW 2141, Australia
| | - Peter Scanes
- Estuaries and Catchments Team, Waters Wetland Coastal Science Branch, NSW Department of Planning, Industry and Environment, Lidcombe, NSW 2141, Australia
| | - Nicole Carnt
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
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Azzopardi M, Chong YJ, Ng B, Recchioni A, Logeswaran A, Ting DSJ. Diagnosis of Acanthamoeba Keratitis: Past, Present and Future. Diagnostics (Basel) 2023; 13:2655. [PMID: 37627913 PMCID: PMC10453105 DOI: 10.3390/diagnostics13162655] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 08/04/2023] [Accepted: 08/09/2023] [Indexed: 08/27/2023] Open
Abstract
Acanthamoeba keratitis (AK) is a painful and sight-threatening parasitic corneal infection. In recent years, the incidence of AK has increased. Timely and accurate diagnosis is crucial during the management of AK, as delayed diagnosis often results in poor clinical outcomes. Currently, AK diagnosis is primarily achieved through a combination of clinical suspicion, microbiological investigations and corneal imaging. Historically, corneal scraping for microbiological culture has been considered to be the gold standard. Despite its technical ease, accessibility and cost-effectiveness, the long diagnostic turnaround time and variably low sensitivity of microbiological culture limit its use as a sole diagnostic test for AK in clinical practice. In this review, we aim to provide a comprehensive overview of the diagnostic modalities that are currently used to diagnose AK, including microscopy with staining, culture, corneal biopsy, in vivo confocal microscopy, polymerase chain reaction and anterior segment optical coherence tomography. We also highlight emerging techniques, such as next-generation sequencing and artificial intelligence-assisted models, which have the potential to transform the diagnostic landscape of AK.
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Affiliation(s)
- Matthew Azzopardi
- Department of Ophthalmology, Royal London Hospital, London E1 1BB, UK;
| | - Yu Jeat Chong
- Birmingham and Midland Eye Centre, Birmingham B18 7QH, UK; (B.N.); (A.R.)
| | - Benjamin Ng
- Birmingham and Midland Eye Centre, Birmingham B18 7QH, UK; (B.N.); (A.R.)
| | - Alberto Recchioni
- Birmingham and Midland Eye Centre, Birmingham B18 7QH, UK; (B.N.); (A.R.)
- Academic Unit of Ophthalmology, Institute of Inflammation and Ageing, University of Birmingham, Birmingham B15 2TT, UK
| | | | - Darren S. J. Ting
- Birmingham and Midland Eye Centre, Birmingham B18 7QH, UK; (B.N.); (A.R.)
- Academic Unit of Ophthalmology, Institute of Inflammation and Ageing, University of Birmingham, Birmingham B15 2TT, UK
- Academic Ophthalmology, School of Medicine, University of Nottingham, Nottingham NG7 2RD, UK
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Ledbetter EC, Capistrano da Silva E, Dong L, McDonough SP. Experimental Induction of Acute Acanthamoeba castellanii Keratitis in Cats. Transl Vis Sci Technol 2023; 12:10. [PMID: 37566398 PMCID: PMC10424800 DOI: 10.1167/tvst.12.8.10] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 07/09/2023] [Indexed: 08/12/2023] Open
Abstract
Purpose To develop a feline model of acute Acanthamoeba keratitis using methods that replicate natural routes of infection transmission. Methods Corneal Acanthamoeba castellanii inoculation was performed by three methods: topical inoculation with Acanthamoeba solution following corneal abrasion, placement of a contaminated contact lens for 7 days, and placement of a contaminated contact lens for 7 days following corneal abrasion. Sham inoculations with parasite-free medium and sterile contact lenses were also performed. Cats were monitored by ocular examination and in vivo corneal confocal microscopy for 21 days post-inoculation. Corneal samples were collected at intervals for microbiologic assessment, histopathology, and immunohistochemistry. Results All cats in the corneal abrasion groups developed clinical keratitis. Clinical ocular disease was inconsistently detected in cats from the contaminated contact lens only group. Initial corneal lesions were characterized by multifocal epithelial leukocyte infiltrates. Ocular lesions progressed to corneal epithelial ulceration and diffuse stromal inflammation. After 14 days, corneal ulcerations resolved, and stromal inflammation consolidated into multifocal subepithelial and stromal infiltrates. Corneal amoebae were detected by culture, in vivo confocal microscopy, histopathology, and immunohistochemistry in cats with keratitis. Neutrophilic and lymphocytic keratoconjunctivitis with lymphoplasmacytic anterior uveitis were identified by histopathology. Coinfection with aerobic bacteria was detected in some, but not all, cats with keratitis. Ocular disease was not detected in the sham inoculation groups. Conclusions Feline Acanthamoeba keratitis is experimentally transmissible by contaminated contact lenses and topical inoculation following corneal epithelial trauma. Translational Relevance Experimentally induced acute Acanthamoeba keratitis in cats is clinically and histopathologically similar to its human counterpart.
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Affiliation(s)
- Eric C. Ledbetter
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | | | - Longying Dong
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Sean P. McDonough
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
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Sarink MJ, Koelewijn R, Stelma F, Kortbeek T, van Lieshout L, Smit PW, Tielens AGM, van Hellemond JJ. An International External Quality Assessment Scheme to Assess the Diagnostic Performance of Polymerase Chain Reaction Detection of Acanthamoeba Keratitis. Cornea 2023; 42:1027-1033. [PMID: 37155347 PMCID: PMC10306335 DOI: 10.1097/ico.0000000000003275] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 02/04/2023] [Accepted: 02/16/2023] [Indexed: 05/10/2023]
Abstract
PURPOSE The purpose of this study was to assess the variation in methods and to determine whether an External Quality Assessment Scheme (EQAS) for polymerase chain reaction (PCR) detection of Acanthamoeba keratitis is valuable for the diagnostic process. METHODS A multicenter EQAS was introduced, covering 16 diagnostic laboratories. Using Acanthamoeba castellanii ATCC strain 30010, 3 sets of samples were prepared, containing different amounts of DNA, cysts, or trophozoites. Samples were masked and sent to the participants with instructions for use and a questionnaire concerning the applied methodologies. Special attention in this questionnaire was given to the used pretreatment methods to assess existing variations in these procedures. RESULTS A large variation in the methodologies and substantial differences in the diagnostic performance were found between participants. In contrast to the DNA samples where all participants had a perfect score, several false negative results were reported for the samples containing cysts or trophozoites. Only 9 participants had an optimal score, whereas one participant reported all samples as negative, one participant reported failures due to inhibition, and the other 5 reported in total 7 false negative results. A clear correlation was noticed between the PCR detection rate and the number of cysts or trophozoites in the sample. CONCLUSIONS The results indicate that a pretreatment procedure can be a risky step in PCR-based detections of Acanthamoeba , but it improves the sensitivity and reliability, especially of samples containing cysts. Therefore, participation in an EQAS is informative for routine diagnostic laboratories and can assist in improving the laboratory procedures used for the diagnosis of Acanthamoeba keratitis.
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Affiliation(s)
- Maarten J. Sarink
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC University Medical Center, Rotterdam, the Netherlands
| | - Rob Koelewijn
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC University Medical Center, Rotterdam, the Netherlands
| | - Foekje Stelma
- Department of Medical Microbiology, Radboudumc Nijmegen, the Netherlands
| | - Titia Kortbeek
- National Institute of Public Health and the Environment, RIVM, Bilthoven, the Netherlands
| | - Lisette van Lieshout
- Department of Parasitology, Leiden University Medical Centre, Leiden, the Netherlands; and
| | - Pieter W. Smit
- Department of Medical Microbiology, Molecular Diagnostics Unit, Maasstad Hospital, Rotterdam, the Netherlands
| | - Aloysius G. M. Tielens
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC University Medical Center, Rotterdam, the Netherlands
| | - Jaap J. van Hellemond
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC University Medical Center, Rotterdam, the Netherlands
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Loufouma Mbouaka A, Lesiak-Markowicz I, Heredero-Bermejo I, Mazumdar R, Walochnik J, Martín-Pérez T. Assessing Acanthamoeba cytotoxicity: comparison of common cell viability assays. Front Microbiol 2023; 14:1175469. [PMID: 37180263 PMCID: PMC10167018 DOI: 10.3389/fmicb.2023.1175469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 04/03/2023] [Indexed: 05/16/2023] Open
Abstract
Background In vitro models for studying interactions between Acanthamoeba and host cells are crucial for understanding the pathomechanism of Acanthamoeba and assessing differences between strains and cell types. The virulence of Acanthamoeba strains is usually assessed and monitored by using cell cytotoxicity assays. The aim of the present study was to evaluate and compare the most widely used cytotoxicity assays for their suitability to assess Acanthamoeba cytopathogenicity. Methods The viability of human corneal epithelial cells (HCECs) after co-culture with Acanthamoeba was evaluated in phase contrast microscopy. Results It was shown that Acanthamoeba is unable to considerably reduce the tetrazolium salt and the NanoLuc® Luciferase prosubstrate to formazan and the luciferase substrate, respectively. This incapacity helped to generate a cell density-dependent signal allowing to accurately quantify Acanthamoeba cytotoxicity. The lactate dehydrogenase (LDH) assay led to an underestimation of the cytotoxic effect of Acanthamoeba on HCECs since their co-incubation negatively affected the lactate dehydrogenase activity. Discussion Our findings demonstrate that cell-based assays using the aqueous soluble tetrazolium-formazan, and the NanoLuc® Luciferase prosubstrate products, in contrast to LDH, are excellent markers to monitor the interaction of Acanthamoeba with human cell lines and to determine and quantify effectively the cytotoxic effect induced by the amoebae. Furthermore, our data indicate that protease activity may have an impact on the outcome and thus the reliability of these tests.
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Affiliation(s)
- Alvie Loufouma Mbouaka
- Center for Pathophysiology, Infectiology and Immunology, Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Iwona Lesiak-Markowicz
- Center for Pathophysiology, Infectiology and Immunology, Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Irene Heredero-Bermejo
- Department of Biomedicine and Biotechnology, Faculty of Pharmacy, University of Alcalá, Madrid, Spain
| | - Rounik Mazumdar
- Max Perutz Labs Vienna, Department of Medical Biochemistry, Medical University of Vienna, Vienna, Austria
| | - Julia Walochnik
- Center for Pathophysiology, Infectiology and Immunology, Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Tania Martín-Pérez
- Center for Pathophysiology, Infectiology and Immunology, Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria
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Siddiqui R, Makhlouf Z, Akbar N, Khamis M, Ibrahim T, Khan AS, Khan NA. Antiamoebic properties of Methyltrioctylammonium chloride based deep eutectic solvents. Cont Lens Anterior Eye 2023; 46:101758. [PMID: 36243521 DOI: 10.1016/j.clae.2022.101758] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Revised: 09/06/2022] [Accepted: 09/09/2022] [Indexed: 11/25/2022]
Abstract
PURPOSE This aim of this study was to assess anti-parasitic properties of deep eutectic solvents against eye pathogen, Acanthamoeba, often associated with the use of contact lens. METHODS Assays were performed to investigate the effects of various Methyltrioctylammonium chloride-based deep eutectic solvents on Acanthamoeba castellanii, comprising amoebicidal assays, encystment assays, excystment assays, cytotoxicity assays by measuring lactate dehydrogenase release from human cells, and cytopathogenicity assays to determine parasite-mediated host cell death. RESULTS In a 2 h incubation period, DES-B, DES-C, DES-D, and DES-E exhibited up to 85 % amoebicidal activity at micromolar doses, which was enhanced further following 24 h incubation. When tested in encystment assays, selected deep eutectic solvents abolished cyst formation and were able to block excystment of A. castellanii. All solvents exhibited minimal human cell cytotoxicity except DES-D. Finally, all tested deep eutectic solvents inhibited amoeba-mediated cytopathogenicity, except DES-B. CONCLUSIONS Deep eutectic solvents show potent antiamoebic effects. These findings are promising and could lead to the development of novel contact lens disinfectants, as well as opening several avenues to explore the molecular mechanisms, various doses and incubation periods, and use of different bases against Acanthamoeba castellanii.
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Affiliation(s)
- Ruqaiyyah Siddiqui
- College of Arts and Sciences, American University of Sharjah, University City, Sharjah 26666, United Arab Emirates; Istinye Faculty of Medicine, Istinye University, Istanbul, Turkey
| | - Zinb Makhlouf
- College of Arts and Sciences, American University of Sharjah, University City, Sharjah 26666, United Arab Emirates
| | - Noor Akbar
- College of Arts and Sciences, American University of Sharjah, University City, Sharjah 26666, United Arab Emirates
| | - Mustafa Khamis
- College of Arts and Sciences, American University of Sharjah, University City, Sharjah 26666, United Arab Emirates
| | - Taleb Ibrahim
- Department of Chemical Engineering, College of Engineering, American University of Sharjah, P.O. Box 26666, Sharjah, United Arab Emirates
| | - Amir Sada Khan
- Department of Chemical Engineering, College of Engineering, American University of Sharjah, P.O. Box 26666, Sharjah, United Arab Emirates; Department of Chemistry, University of Science & Technology, Banuu 28100, Khyber Pakhtunkhwa, C
| | - Naveed Ahmed Khan
- Department of Clinical Sciences, College of Medicine, University of Sharjah, University, City, Sharjah 27272, United Arab Emirates; Istinye Faculty of Medicine, Istinye University, Istanbul, Turkey..
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Abstract
Infectious keratitis is a rare but potentially severe sight-threatening disease, associated with considerable societal burden, cost and morbidity. This review summarises the most recent evidence for the incidence, risk factors and impact of disease, all of which vary widely according to region, access to health care, socioeconomic and environmental factors, predisposing conditions and causative organisms. The frequency and societal impact of infectious keratitis are significantly higher in low-income countries. In non-viral infectious keratitis, bacterial causes predominate in most regions. Fungi, particularly linked with agricultural trauma, are more frequently associated with infectious keratitis in low-income regions, particularly in India and certain African countries. The disease impact is compounded by poverty and limited access to services and treatment. Early diagnosis, access to appropriate treatment, prophylaxis in ocular trauma, availability of eye protection, awareness of risk factors may be associated with reduced disease severity and vision loss. Evidence for the incidence and burden of disease is lacking in certain regions and well-designed epidemiological studies to identify independent risk factors for the disease and those associated with more severe outcomes may better identify causation and guide resource allocation and preventative strategies.
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Affiliation(s)
- Fiona Stapleton
- School of Optometry and Vision Science, UNSW, Level 3, North Wing, RMB, Gate 14, Barker St, Sydney, NSW, 2052, Australia.
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Zhang Y, Xu X, Wei Z, Cao K, Zhang Z, Liang Q. The global epidemiology and clinical diagnosis of Acanthamoeba keratitis. J Infect Public Health 2023; 16:841-852. [PMID: 37030037 DOI: 10.1016/j.jiph.2023.03.020] [Citation(s) in RCA: 50] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 03/05/2023] [Accepted: 03/20/2023] [Indexed: 04/10/2023] Open
Abstract
Acanthamoeba keratitis is a rare parasitic infection of the cornea that can lead to permanent blindness if not diagnosed and treated promptly. We collected data on the incidences of Acanthamoeba keratitis from 20 countries and calculated an annual incidence of 23,561 cases, with the lowest rates in Tunisia and Belgium, and the highest in India. We analyzed 3755 Acanthamoeba sequences from the GenBank database across Asia, Europe, North America, South America, and Oceania and genotyped them into T1, T2, T3, T4, T5, T10, T11, T12, and T15. Many genotypes possess different characteristics, yet T4 is the most prevalent genotype. As efficient treatment against Acanthamoeba remains lacking, prevention from early diagnosis via staining, PCR, or in vivo confocal microscopy (IVCM) becomes significant for the condition's prognosis. IVCM is the most recommended approach for the early detection of Acanthamoeba. If IVCM is unavailable, PCR should be used as an alternative.
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Affiliation(s)
- Yuheng Zhang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing 100005, China
| | - Xizhan Xu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing 100005, China
| | - Zhenyu Wei
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing 100005, China
| | - Kai Cao
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing 100005, China
| | - Zijun Zhang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing 100005, China
| | - Qingfeng Liang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing 100005, China.
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Impact of implementation of polymerase chain reaction on diagnosis, treatment, and clinical course of Acanthamoeba keratitis. Graefes Arch Clin Exp Ophthalmol 2023:10.1007/s00417-023-05993-7. [PMID: 36795161 DOI: 10.1007/s00417-023-05993-7] [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: 06/08/2022] [Revised: 01/24/2023] [Accepted: 01/31/2023] [Indexed: 02/17/2023] Open
Abstract
PURPOSE Acanthamoeba keratitis (AK) is a painful and possibly sight-threatening ocular infection. While the correct diagnosis and specific treatment in the early stages significantly improve the prognosis, the disease is often misdiagnosed and in clinical examination confused with other forms of keratitis. Polymerase chain reaction (PCR) for the detection of AK was first introduced in our institution in December 2013 to improve the timely diagnosis of AK. The aim of this study was to assess the impact of implementation of Acanthamoeba PCR on the diagnosis and treatment of the disease in a German tertiary referral center. PATIENTS AND METHODS Patients treated for Acanthamoeba keratitis between 1st of January 1993 and 31st of December 2021 in the Department of Ophthalmology of the University Hospital Duesseldorf were identified retrospectively via in-house registries. Evaluated parameters include age, sex, initial diagnosis, method of correct diagnosis, duration of symptoms until correct diagnosis, contact lens use, visual acuity, and clinical findings as well as medical and surgical therapy by keratoplasty (pKP). In order to assess the impact of implementation of Acanthamoeba PCR, the cases were divided into two groups (before (pre-PCR group) and after PCR implementation (PCR group). RESULTS Seventy-five patients with Acanthamoeba keratitis were included (69.3% female, median age 37 years). Eighty-four percent (63/75) of all patients were contact lens wearers. Until PCR was available, 58 patients with Acanthamoeba keratitis were diagnosed either clinically (n = 28), by histology (n = 21), culture (n = 6), or confocal microscopy (n = 2) with a median duration until diagnosis of 68 (18; 109) days. After PCR implementation, in 17 patients, the diagnosis was established with PCR in 94% (n = 16) and median duration until diagnosis was significantly shorter with 15 (10; 30.5) days. A longer duration until correct diagnosis correlated with a worse initial visual acuity (p = 0.0019, r = 0.363). The number of pKP performed was significantly lower in the PCR group (5/17; 29.4%) than in the pre-PCR group (35/58; 60.3%) (p = 0.025). CONCLUSIONS The choice of diagnostic method and especially the application of PCR have a significant impact on the time to diagnosis and on the clinical findings at the time of confirmation of diagnosis and the need for penetrating keratoplasty. In contact lens-associated keratitis, the first crucial step is to take AK into consideration and perform a PCR test as timely confirmation of diagnosis of AK is imperative to prevent long-term ocular morbidity.
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Tuft S, Bunce C, De S, Thomas J. Utility of investigation for suspected microbial keratitis: a diagnostic accuracy study. Eye (Lond) 2023; 37:415-420. [PMID: 35102245 PMCID: PMC9905491 DOI: 10.1038/s41433-022-01952-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 01/14/2022] [Accepted: 01/19/2022] [Indexed: 11/09/2022] Open
Abstract
PURPOSE The true disease status of a population with suspected microbial keratitis (MK) cannot be verified. There is not an accurate (gold) reference standard to confirm infection and inter-test comparisons of sensitivity and specificity therefore lead to bias with questionable estimates of test utility. We present an alternative method to report results. METHODS We used a decision to treat as the definition for MK. We retrospectively compared the results of corneal culture and polymerase chain reaction (PCR) as these are objective tests available for the three principal groups of pathogens. We then estimated the potential contribution of positive results, either alone or in combination, to support the working diagnosis. RESULTS We included 2021 (77.4%) eyes with suspected bacterial keratitis, 365 (14.0%) with suspected acanthamoeba keratitis, and 226 (8.6%) with suspected fungal keratitis, all treated between July 2013 and December 2019. In these groups, there were 51.6% positive culture and 6.5% positive PCR results for bacteria, 19.0% and 40.5% for acanthamoeba, and 28.3% and 15.0% for fungi. Between groups the differences in the proportions of positive results from culture and PCR was statistically significant (P < 0.001). The added benefit of PCR to the result of culture in identifying a potential pathogen was 1.4% for bacteria (P = 0.6292), 24.4% for acanthamoeba (P = 0.0001), and 5.8% for fungi (P = 0.3853). CONCLUSIONS For suspected MK a comparison of the test positivity rate is an easily comprehensible outcome measure of test utility.
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Affiliation(s)
- Stephen Tuft
- Moorfields Eye Hospital, 162 City Road, London, EC1V 2PD, UK.
| | - Catey Bunce
- The Royal Marsden Hospital, 203 Fulham Rd, Chelsea, London, SW3 6JJ, UK
| | - Surjo De
- Department of Clinical Microbiology, University College London Hospitals, 235 Euston Rd, London, NW1 2BU, UK
| | - John Thomas
- Micropathology Limited, Venture Centre, Sir William Lyons Road, Coventry, CV4 7EZ, UK
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Randag AC, de Kroon L, Otten H, Arias Claro-Handgraaf C, Schimmer B, Kortbeek T, van Rooij J, Stelma FF. In Vitro Effectiveness of Soft Contact Lens Solutions Available on the Dutch Market against Acanthamoeba Species. Pathogens 2023; 12:pathogens12020214. [PMID: 36839486 PMCID: PMC9959425 DOI: 10.3390/pathogens12020214] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 01/21/2023] [Accepted: 01/25/2023] [Indexed: 01/31/2023] Open
Abstract
Acanthamoeba keratitis is almost universally associated with contact lens (CL) use. Until today, however, CL solution manufacturing protocols lack testing of anti-amoebic activity. This study investigates the effectiveness of CL solutions available on the Dutch market against trophozoites and cysts of Acanthamoeba castellanii and Acanthamoeba polyphaga. Sixteen CL solutions were tested: 13 multiple purpose solutions (MPS), 2 hydrogen peroxidase solutions (HPS) and 1 povidone-iodine-based solution (PIS). The Spearman-Karber (SK) log reduction method and an XTT colorimetric assay were used to evaluate the effectiveness at the manufacturer's minimum recommended disinfection time (MMRDT) and after eight hours. At the MMRDT, one MPS showed an SK mean log reduction (MLR) of >3.0 against A. castellanii trophozoites. Two additional MPS and both HPS reached this threshold after eight hours. The SK MLR values for A. polyphaga trophozoites were between 1 and 3 at all time points. Using the XTT colorimetric assay, only HPS 1 showed >99.9% reduction (equivalent to 3 log reduction) in metabolic activity of A. castellanii trophozoites after eight hours. For A. polyphaga, both HPS and PIS showed a metabolic reduction of >99.9% after eight hours. Cysts were resistant against all solutions. We conclude that following the manufacturer's guidelines, few solutions provide sufficient effectiveness against Acanthamoeba trophozoites and none against cysts. The results underline the importance of adequate hygiene when handling CLs.
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Affiliation(s)
- Anna C. Randag
- Rotterdam Eye Hospital, Schiedamse Vest 180, 3011 BH Rotterdam, The Netherlands
- Rotterdam Ophthalmic Institute, Schiedamse Vest 160, 3011 BH Rotterdam, The Netherlands
- Correspondence:
| | - Lieke de Kroon
- Radboud University Medical Center, Postbus 9101, 6500 HB Nijmegen, The Netherlands
| | - Henny Otten
- Visser Contactlenzen, St. Annastraat 93, 6524 EJ Nijmegen, The Netherlands
| | | | - Barbara Schimmer
- National Institute for Public Health and the Environment (RIVM), Postbus 1, 3720 BA Bilthoven, The Netherlands
| | - Titia Kortbeek
- National Institute for Public Health and the Environment (RIVM), Postbus 1, 3720 BA Bilthoven, The Netherlands
| | - Jeroen van Rooij
- Rotterdam Eye Hospital, Schiedamse Vest 180, 3011 BH Rotterdam, The Netherlands
- Rotterdam Ophthalmic Institute, Schiedamse Vest 160, 3011 BH Rotterdam, The Netherlands
| | - Foekje F. Stelma
- Radboud University Medical Center, Postbus 9101, 6500 HB Nijmegen, The Netherlands
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Carnt N, Minassian DC, Dart JKG. Acanthamoeba Keratitis Risk Factors for Daily Wear Contact Lens Users: A Case-Control Study. Ophthalmology 2023; 130:48-55. [PMID: 35952937 DOI: 10.1016/j.ophtha.2022.08.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 08/02/2022] [Accepted: 08/02/2022] [Indexed: 01/06/2023] Open
Abstract
PURPOSE This study was designed to establish risk factors for the development of Acanthamoeba keratitis (AK) for daily disposable (DD) contact lens (CL) users compared with daily wear (DW) reusable lens users and for risks unique to DD users. This is important because, in many major economies, CL use is the principal cause of microbial keratitis, of which AK accounts for approximately 50% of cases with sight loss. Determining these AK risks informs practitioner advice and consumer behavior. DESIGN Case-control study. PARTICIPANTS Cases and controls were recruited from an Accident and Emergency Department serving South-East England. Cases were new CL users with AK recruited retrospectively from January 2011 to February 2013 and prospectively thereafter until August 2014. Controls were recruited prospectively from February 2014 to June 2015. METHODS Analysis of a self-administered questionnaire. MAIN OUTCOME MEASURES Independent risk factors and population attributable risk percentage (PAR%) for AK. RESULTS A total of 83 AK cases and 122 controls were recruited; DD use was reported by 20 (24%) cases and 66 (54%) controls. In multivariable analyses adjusted for potential confounders, the odds of AK was higher for DW reusable soft lenses (odds ratio [OR], 3.84; 95% confidence interval [CI], 1.75-8.43) and rigid lenses (OR, 4.56; 95% CI, 1.03-20.19) than for DD lenses. Within the DD-using subset, AK was associated with the following modifiable risk factors: less frequent professional follow-up visits (OR, 10.12; 95% CI, 5.01-20.46); showering in lenses (OR, 3.29, 95% CI, 1.17-9.23); lens reuse (OR, 5.41; 95% CI, 1.55-18.89); and overnight wear (OR, 3.93; 95% CI, 1.15-13.46). The PAR% estimated that 30% to 62% of cases could be prevented by switching from reusable soft lens to DD lens use. CONCLUSIONS Acanthamoeba keratitis risks are increased > threefold in DW reusable lens users versus DD lens use. Acanthamoeba keratitis risks for DD lens users can be minimized by adherence to safe use guidelines (no reuse, overnight wear, or contamination by water). Safe CL use can be improved by increasing the prominence of risk avoidance information from manufacturers and regulators. Because AK accounts for half of severe keratitis in CL users, these measures can be expected to have public health benefits.
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Affiliation(s)
- Nicole Carnt
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia; Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom; National Institute of Health Research Moorfields Biomedical Research Centre, London, United Kingdom
| | | | - John K G Dart
- Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom; National Institute of Health Research Moorfields Biomedical Research Centre, London, United Kingdom.
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Campolo A, Pifer R, Walters R, Thomas M, Miller E, Harris V, King J, Rice CA, Shannon P, Patterson B, Crary M. Acanthamoeba spp. aggregate and encyst on contact lens material increasing resistance to disinfection. Front Microbiol 2022; 13:1089092. [PMID: 36601401 PMCID: PMC9806144 DOI: 10.3389/fmicb.2022.1089092] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 11/28/2022] [Indexed: 12/23/2022] Open
Abstract
Introduction Acanthamoeba keratitis is often caused when Acanthamoeba contaminate contact lenses and infect the cornea. Acanthamoeba is pervasive in the environment as a motile, foraging trophozoite or biocide-resistant and persistent cyst. As contact lens contamination is a potential first step in infection, we studied Acanthamoeba's behavior and interactions on different contact lens materials. We hypothesized that contact lenses may induce aggregation, which is a precursor to encystment, and that aggregated encystment would be more difficult to disinfect than motile trophozoites. Methods Six clinically and/or scientifically relevant strains of Acanthamoeba (ATCC 30010, ATCC 30461, ATCC 50370, ATCC 50702, ATCC 50703, and ATCC PRA-115) were investigated on seven different common silicone hydrogel contact lenses, and a no-lens control, for aggregation and encystment for 72 h. Cell count and size were used to determine aggregation, and fluorescent staining was used to understand encystment. RNA seq was performed to describe the genome of Acanthamoeba which was individually motile or aggregated on different lens materials. Disinfection efficacy using three common multi-purpose solutions was calculated to describe the potential disinfection resistance of trophozoites, individual cysts, or spheroids. Results Acanthamoeba trophozoites of all strains examined demonstrated significantly more aggregation on specific contact lens materials than others, or the no-lens control. Fluorescent staining demonstrated encystment in as little as 4 hours on contact lens materials, which is substantially faster than previously reported in natural or laboratory settings. Gene expression profiles corroborated encystment, with significantly differentially expressed pathways involving actin arrangement and membrane complexes. High disinfection resistance of cysts and spheroids with multi-purpose solutions was observed. Discussion Aggregation/encystment is a protective mechanism which may enable Acanthamoeba to be more disinfection resistant than individual trophozoites. This study demonstrates that some contact lens materials promote Acanthamoeba aggregation and encystment, and Acanthamoeba spheroids obstruct multi-purpose solutions from disinfecting Acanthamoeba.
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Affiliation(s)
| | - Reed Pifer
- Alcon Research, LLC, Fort Worth, TX, United States
| | | | - Megan Thomas
- Alcon Research, LLC, Fort Worth, TX, United States
| | - Elise Miller
- Alcon Research, LLC, Fort Worth, TX, United States
| | | | - Jamie King
- Alcon Research, LLC, Fort Worth, TX, United States
| | - Christopher A. Rice
- Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, IN, United States,Purdue Institute for Drug Discovery (PIDD), Purdue University, West Lafayette, IN, United States,Purdue Institute of Inflammation, Immunology and Infectious Disease (PI4D), Purdue University, West Lafayette, IN, United States
| | - Paul Shannon
- Alcon Research, LLC, Fort Worth, TX, United States
| | | | - Monica Crary
- Alcon Research, LLC, Fort Worth, TX, United States,*Correspondence: Monica Crary,
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Chen L, Kuang L, Ross AE, Farhat W, Boychev N, Sharfi S, Kanu LN, Liu L, Kohane DS, Ciolino JB. Topical Sustained Delivery of Miltefosine Via Drug-Eluting Contact Lenses to Treat Acanthamoeba Keratitis. Pharmaceutics 2022; 14:pharmaceutics14122750. [PMID: 36559244 PMCID: PMC9781349 DOI: 10.3390/pharmaceutics14122750] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 11/18/2022] [Accepted: 11/23/2022] [Indexed: 12/13/2022] Open
Abstract
This study aimed to develop a miltefosine-eluting contact lens (MLF-CL) device that would allow sustained and localized miltefosine release for the treatment of Acanthamoeba keratitis. MLF-CLs were produced in three different miltefosine doses by solvent-casting a thin miltefosine-polymer film around the periphery of a methafilcon hydrogel, which was then lathed into a contact lens. During seven days of in vitro testing, all three formulations demonstrated sustained release from the lens at theoretically therapeutic levels. Based on the physicochemical characterization of MLF-CLs, MLF-CL's physical properties are not significantly different from commercial contact lenses in terms of light transmittance, water content and wettability. MLF-CLs possessed a slight reduction in compression modulus that was attributed to the inclusion of polymer-drug films but still remain within the optimal range of soft contact lenses. In cytotoxicity studies, MLF-CL indicated up to 91% viability, which decreased proportionally as miltefosine loading increased. A three-day biocompatibility test on New Zealand White rabbits revealed no impact of MLF-CLs on the corneal tissue. The MLF-CLs provided sustained in vitro release of miltefosine for a week while maintaining comparable physical features to a commercial contact lens. MLF-CL has a promising potential to be used as a successful treatment method for Acanthamoeba keratitis.
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Affiliation(s)
- Lin Chen
- Department of Optometry and Visual Science, West China Hospital, Sichuan University, Chengdu 610041, China
- Department of Ophthalmology, Affiliated Hospital of Zunyi Medical University, Zunyi 563000, China
- Department of Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA
| | - Liangju Kuang
- Department of Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA
- Correspondence: (L.K.); (J.B.C.)
| | - Amy E. Ross
- Department of Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA
| | - Wissam Farhat
- Department of Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA
| | - Nikolay Boychev
- Department of Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA
| | - Sina Sharfi
- Department of Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA
| | - Levi N. Kanu
- Department of Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA
| | - Longqian Liu
- Department of Optometry and Visual Science, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Daniel S. Kohane
- Department of Anesthesia, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Joseph B. Ciolino
- Department of Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA
- Correspondence: (L.K.); (J.B.C.)
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The Activity of Polyhomoarginine against Acanthamoeba castellanii. BIOLOGY 2022; 11:biology11121726. [PMID: 36552236 PMCID: PMC9774714 DOI: 10.3390/biology11121726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Revised: 11/18/2022] [Accepted: 11/24/2022] [Indexed: 11/30/2022]
Abstract
Arginine-rich peptides can have broad-spectrum anti-bacterial and anti-fungal activities. Polyhomoarginine consists of highly cationic residues which can act on the negatively charged microbial cell membranes. Acanthamoeba is a free-living protozoan known to cause a rare corneal infection which is difficult to diagnose and treat. This study evaluated the activity of the polyhomoarginines against Acanthamoeba castellanii. Acanthamoeba amoebicidal, amoebistatic, encystation and excystment assays were performed using protocols described in the literature. The activity of polyhomoarginines (PHAs) of different lengths (10 to 400 residues) was measured against the trophozoites and cysts of Acanthamoeba castellanii ATCC30868 in concentrations ranging from 0.93 μM to 15 μM. Data were represented as mean ± SE and analysed using one-way ANOVA. Overall, PHAs demonstrated good anti-acanthamoeba activity against both trophozoites and cysts. PHA 30 reduced the number of viable trophozoites by 99%, inhibited the formation of cysts by 96% and the emergence of trophozoites from cysts by 67% at 3.75 μM. PHA 10 was similarly active, but at a slightly higher concentration of 15 μM, reducing the numbers of viable trophozoites by 98%, inhibiting cyst formation by 84% and preventing the emergence of trophozoites from cysts by 99%. At their greatest anti-amoeba concentrations, PHA 10 gave only 8% haemolysis at 15 μM while PHA 30 gave <40 % haemolysis at 3.75 μM. Polyhomoarginine 10 showed excellent anti-amoebic activity against both forms of Acanthamoeba castellanii and was non-toxic at its most active concentrations. This implies that polyhomoarginines can be developed into a potential therapeutic agent for Acanthamoeba keratitis. However, there is a need to carry out further pre-clinical and then in vivo experiments in the AK animal model.
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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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Rayamajhee B, Willcox MDP, Henriquez FL, Petsoglou C, Subedi D, Carnt N. Acanthamoeba, an environmental phagocyte enhancing survival and transmission of human pathogens. Trends Parasitol 2022; 38:975-990. [PMID: 36109313 DOI: 10.1016/j.pt.2022.08.007] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 08/10/2022] [Accepted: 08/11/2022] [Indexed: 01/13/2023]
Abstract
The opportunistic protist Acanthamoeba, which interacts with other microbes such as bacteria, fungi, and viruses, shows significant similarity in cellular and functional aspects to human macrophages. Intracellular survival of microbes in this microbivorous amoebal host may be a crucial step for initiation of infection in higher eukaryotic cells. Therefore, Acanthamoeba-microbe adaptations are considered an evolutionary model of macrophage-pathogen interactions. This paper reviews Acanthamoeba as an emerging human pathogen and different ecological interactions between Acanthamoeba and microbes that may serve as environmental training grounds and a genetic melting pot for the evolution, persistence, and transmission of potential human pathogens.
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Affiliation(s)
- Binod Rayamajhee
- School of Optometry and Vision Science, Faculty of Medicine and Health, University of New South Wales (UNSW), Sydney, Australia.
| | - Mark D P Willcox
- School of Optometry and Vision Science, Faculty of Medicine and Health, University of New South Wales (UNSW), Sydney, Australia.
| | - Fiona L Henriquez
- Institute of Biomedical and Environmental Health Research, School of Health and Life Sciences, University of the West of Scotland, Blantyre, South Lanarkshire, G72 0LH, UK
| | - Constantinos Petsoglou
- Sydney and Sydney Eye Hospital, Southeastern Sydney Local Health District, Sydney, Australia; Save Sight Institute, University of Sydney, Sydney, Australia
| | - Dinesh Subedi
- School of Biological Sciences, Monash University, Clayton, Australia
| | - Nicole Carnt
- School of Optometry and Vision Science, Faculty of Medicine and Health, University of New South Wales (UNSW), Sydney, Australia
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Rayamajhee B, Sharma S, Willcox M, Henriquez FL, Rajagopal RN, Shrestha GS, Subedi D, Bagga B, Carnt N. Assessment of genotypes, endosymbionts and clinical characteristics of Acanthamoeba recovered from ocular infection. BMC Infect Dis 2022; 22:757. [PMID: 36175838 PMCID: PMC9520893 DOI: 10.1186/s12879-022-07741-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 09/12/2022] [Indexed: 11/22/2022] Open
Abstract
Introduction Acanthamoeba is an emerging pathogen, infamous for its resilience against antiprotozoal compounds, disinfectants and harsh environments. It is known to cause keratitis, a sight-threatening, painful and difficult to treat corneal infection which is often reported among contact lens wearers and patients with ocular trauma. Acanthamoeba comprises over 24 species and currently 23 genotypes (T1-T23) have been identified. Aims This retrospective study was designed to examine the Acanthamoeba species and genotypes recovered from patients with Acanthamoeba keratitis (AK), determine the presence of endosymbionts in ocular isolates of Acanthamoeba and review the clinical presentations. Methodology Thirteen culture-confirmed AK patients treated in a tertiary eye care facility in Hyderabad, India from February to October 2020 were included in this study. The clinical manifestations, medications and visual outcomes of all patients were obtained from medical records. The Acanthamoeba isolates were identified by sequencing the ribosomal nuclear subunit (rns) gene. Acanthamoeba isolates were assessed for the presence of bacterial or fungal endosymbionts using molecular assays, PCR and fluorescence in situ hybridization (FISH). Results The mean age of the patients was 33 years (SD ± 17.4; 95% CI 22.5 to 43.5 years). Six (46.2%) cases had AK associated risk factors; four patients had ocular trauma and two were contact lens wearers. A. culbertsoni (6/13, 46.2%) was the most common species, followed by A. polyphaga and A. triangularis. Most of the isolates (12/13) belonged to genotype T4 and one was a T12; three sub-clusters T4A, T4B, and T4F were identified within the T4 genotype. There was no significant association between Acanthamoeba types and clinical outcomes. Eight (61.5%) isolates harboured intracellular bacteria and one contained Malassezia restricta. The presence of intracellular microbes was associated with a higher proportion of stromal infiltrates (88.9%, 8/9), epithelial defect (55.6%, 5/9) and hypopyon (55.6%, 5/9) compared to 50% (2/4), 25% (1/4) and 25% (1/4) AK cases without intracellular microbes, respectively. Conclusions Genotype T4 was the predominant isolate in southern India. This is the second report of T12 genotype identified from AK patient in India, which is rarely reported worldwide. The majority of the Acanthamoeba clinical isolates in this study harboured intracellular microbes, which may impact clinical characteristics of AK. Supplementary Information The online version contains supplementary material available at 10.1186/s12879-022-07741-4.
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Affiliation(s)
- Binod Rayamajhee
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia.
| | - Savitri Sharma
- Jhaveri Microbiology Centre, Prof. Brien Holden Eye Research Centre, Hyderabad Eye Research Foundation, L. V. Prasad Eye Institute (LVPEI), Kallam Anji Reddy Campus, Hyderabad, India
| | - Mark Willcox
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
| | - Fiona L Henriquez
- Institute of Biomedical and Environmental Health Research, School of Health and Life Sciences, University of the West of Scotland (UWS), Paisley, PA1 2BE, Scotland, UK
| | | | - Gauri Shankar Shrestha
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
| | - Dinesh Subedi
- School of Biological Sciences, Monash University, Clayton, VIC, 3800, Australia
| | - Bhupesh Bagga
- The Cornea Institute, L V Prasad Eye Institute, Banjara Hills, Hyderabad, India
| | - Nicole Carnt
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
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Fechtali-Moute Z, Loiseau PM, Pomel S. Stimulation of Acanthamoeba castellanii excystment by enzyme treatment and consequences on trophozoite growth. Front Cell Dev Biol 2022; 10:982897. [PMID: 36172275 PMCID: PMC9511172 DOI: 10.3389/fcell.2022.982897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 08/17/2022] [Indexed: 11/13/2022] Open
Abstract
Acanthamoeba castellanii is a widespread Free-Living Amoeba (FLA) that can cause severe ocular or cerebral infections in immunocompetent and immunocompromised patients, respectively, besides its capacity to transport diverse pathogens. During their life cycle, FLA can alternate between a vegetative form, called a trophozoite, and a latent and resistant form, called a cyst. This resistant form is characterized by the presence of a cell wall containing two layers, namely the ectocyst and the endocyst, mainly composed of cellulose and proteins. In the present work, we aimed to stimulate Acanthamoeba castellanii excystment by treating their cysts with a cellulolytic enzyme, i.e., cellulase, or two proteolytic enzymes, i.e., collagenase and pepsin. While 11 days were necessary to obtain total excystment in the control at 27°C, only 48 h were sufficient at the same temperature to obtain 100% trophozoites in the presence of 25 U/mL cellulase, 50 U/mL collagenase or 100 U/mL pepsin. Additionally, more than 96% amoebae have excysted after only 24 h with 7.5 U/mL cellulase at 30°C. Nevertheless, no effect of the three enzymes was observed on the excystment of Balamuthia mandrillaris and Vermamoeba vermiformis. Surprisingly, A. castellanii trophozoites excysted in the presence of cellulase displayed a markedly shorter doubling time at 7 h, in comparison to the control at 23 h. Likewise, trophozoites doubled their population in 9 h when both cellulose and cellulase were added to the medium, indicating that Acanthamoeba cyst wall degradation products promote their trophozoite proliferation. The analysis of cysts in epifluorescent microscopy using FITC-lectins and in electron microscopy revealed a disorganized endocyst and a reduction of the intercystic space area after cellulase treatment, implying that these cellular events are preliminary to trophozoite release during excystment. Further studies would be necessary to determine the signaling pathways involved during this amoebal differentiation process to identify new therapeutic targets for the development of anti-acanthamoebal drugs.
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Ahmed NH, Rathod PG, Satpathy G, Tandon R, Sharma N, Titiyal JS. Acanthamoeba keratitis: Experience from a tertiary eye care center in North India. Trop Parasitol 2022; 12:119-123. [PMID: 36643983 PMCID: PMC9832494 DOI: 10.4103/tp.tp_16_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 05/29/2022] [Accepted: 06/29/2022] [Indexed: 11/25/2022] Open
Abstract
The free-living amebae of genus Acanthamoeba are an important cause of microbial keratitis. The clinical appearance of Acanthamoeba keratitis (AK) usually mimics viral or fungal keratitis. Thus, microbiological workup plays a significant role in the diagnosis and timely treatment of such cases. We report a retrospective case series of seven culture-confirmed AK cases from a tertiary eye care center in North India. Various risk factors and triggers of infection, clinical presentations, microbiological findings, and management of AK are elucidated.
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Affiliation(s)
- Nishat Hussain Ahmed
- Department of Ocular Microbiology, Dr. R. P. Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Prachala G Rathod
- Department of Ocular Microbiology, Dr. R. P. Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Gita Satpathy
- Department of Ocular Microbiology, Dr. R. P. Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Radhika Tandon
- Department of Ophthalmology, Dr. R. P. Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Namrata Sharma
- Department of Ophthalmology, Dr. R. P. Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Jeewan S Titiyal
- Department of Ophthalmology, Dr. R. P. Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
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Eldeek HE, Farrag HMM, Tolba MEM, El-Deek HE, Ali MO, Ibraheim ZZ, Bayoumi SA, Hassanin ESA, Alkhalil SS, Huseein EAEHM. Amoebicidal effect of Allium cepa against Allovahlkampfia spelaea: A keratitis model. Saudi Pharm J 2022; 30:1120-1136. [PMID: 36164578 PMCID: PMC9508644 DOI: 10.1016/j.jsps.2022.06.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 06/10/2022] [Indexed: 11/27/2022] Open
Abstract
Allovahlkampfia spelaea (A. spelaea) is a free-living amoeba, proved to cause Acanthamoeba-like keratitis with quite difficult treatment. This study aimed to evaluate the amoebicidal effect of Allium cepa (A. cepa) on A. spelaea trophozoites and cysts both in vitro and in vivo using Chinchilla rabbits as an experimental model of this type of keratitis. Chemical constituents of the aqueous extract of A. cepa were identified using Liquid Chromatography-mass Spectrometry (LC-MS). In vitro, A. cepa showed a significant inhibitory effect on trophozoites and cysts compared to the reference drug, chlorhexidine (CHX) as well as the non-treated control (P < 0.05) with statistically different effectiveness in terms of treatment durations and concentrations. No cytotoxic effect of A. cepa on corneal cell line was found even at high concentrations (32 mg/ml) using agar diffusion method. The in vivo results confirmed the efficacy of A. cepa where the extract enhanced keratitis healing with complete resolution of corneal ulcers in 80% of the infected animals by day 14 (post infection)pi compared to 70% recovery with CHX after 20 treatment days. The therapeutic effect was also approved at histological, immune-histochemical, and parasitological levels. Our findings support the potential use of A. cepa as an effective agent against A. spelaea keratitis.
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Salehi M, Spotin A, Hajizadeh F, Soleimani F, Shokri A. Molecular characterization of Acanthamoeba spp. from different sources in Gonabad, Razavi Khorasan, Iran. GENE REPORTS 2022. [DOI: 10.1016/j.genrep.2022.101573] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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50
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Acanthamoeba more commonly causes epithelial keratitis than herpes simplex in South-East England contact lens users. Infection 2022; 50:1619-1622. [PMID: 35641777 DOI: 10.1007/s15010-022-01857-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Accepted: 05/12/2022] [Indexed: 11/05/2022]
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