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Raghavan A, Rammohan R. Acanthamoeba keratitis - A review. Indian J Ophthalmol 2024; 72:473-482. [PMID: 38454853 PMCID: PMC11149514 DOI: 10.4103/ijo.ijo_2627_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 12/23/2023] [Indexed: 03/09/2024] Open
Abstract
This is a comprehensive review after a thorough literature search in PubMed-indexed journals, incorporating current information on the pathophysiology, clinical features, diagnosis, medical and surgical therapy, as well as outcomes of Acanthamoeba keratitis (AK). AK is a significant cause of ocular morbidity, and early diagnosis with timely institution of appropriate therapy is the key to obtaining good outcomes. The varied presentations result in frequent misdiagnosis, and co-infections can increase the morbidity of the disease. The first line of therapy continues to be biguanides and diamidines, with surgery as a last resort.
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Affiliation(s)
- Anita Raghavan
- Cornea & Refractive Surgery, Department of Microbiology, Aravind Eye Hospital and Post-Graduate Institute of Ophthalmology, Coimbatore, Tamil Nadu, India
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Kennedy SM, Deshpande P, Gallagher AG, Horsburgh MJ, Allison HE, Kaye SB, Wellings DA, Williams RL. Amoebicidal Activity of Poly-Epsilon-Lysine Functionalized Hydrogels. Invest Ophthalmol Vis Sci 2022; 63:11. [PMID: 34994769 PMCID: PMC8742527 DOI: 10.1167/iovs.63.1.11] [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] [Indexed: 11/24/2022] Open
Abstract
Purpose To determine the amoebicidal activity of functionalized poly-epsilon-lysine hydrogels (pɛK+) against Acanthamoeba castellanii. Methods A. castellanii trophozoites and cysts were grown in the presence of pɛK solution (0–2.17 mM), pɛK or pɛK+ hydrogels, or commercial hydrogel contact lens (CL) for 24 hours or 7 days in PBS or Peptone-Yeast-Glucose (PYG) media (nutrient-deplete or nutrient-replete cultures, respectively). Toxicity was determined using propidium iodide and imaged using fluorescence microscopy. Ex vivo porcine corneas were inoculated with A. castellanii trophozoites ± pɛK, pɛK+ hydrogels or commercial hydrogel CL for 7 days. Corneal infection was assessed by periodic acid–Schiff staining and histologic analysis. Regrowth of A. castellanii from hydrogel lenses and corneal discs at 7 days was assessed using microscopy and enumeration. Results The toxicity of pɛK+ hydrogels resulted in the death of 98.52% or 83.31% of the trophozoites at 24 hours or 7 days, respectively. The toxicity of pɛK+ hydrogels resulted in the death of 70.59% or 82.32% of the cysts in PBS at 24 hours or 7 days, respectively. Cysts exposed to pɛK+ hydrogels in PYG medium resulted in 75.37% and 87.14% death at 24 hours and 7 days. Ex vivo corneas infected with trophozoites and incubated with pɛK+ hydrogels showed the absence of A. castellanii in the stroma, with no regrowth from corneas or pɛK+ hydrogel, compared with infected-only corneas and those incubated in presence of commercial hydrogel CL. Conclusions pɛK+ hydrogels demonstrated pronounced amoebicidal and cysticidal activity against A. castellanii. pɛK+ hydrogels have the potential for use as CLs that could minimize the risk of CL-associated Acanthamoeba keratitis.
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Affiliation(s)
- Stephnie M Kennedy
- Department of Eye and Vision Science, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Pallavi Deshpande
- Department of Eye and Vision Science, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Andrew G Gallagher
- SpheriTech Ltd, The Heath Business and Technical Park, Runcorn, Cheshire, United Kingdom
| | - Malcolm J Horsburgh
- Department of Infection Biology and Microbiomes, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Heather E Allison
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Stephen B Kaye
- Department of Eye and Vision Science, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Donald A Wellings
- SpheriTech Ltd, The Heath Business and Technical Park, Runcorn, Cheshire, United Kingdom
| | - Rachel L Williams
- Department of Eye and Vision Science, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom
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Raghavan A, Baidwal S, Venkatapathy N, Rammohan R. The Acanthamoeba-Fungal Keratitis Study. Am J Ophthalmol 2019; 201:31-36. [PMID: 30721687 DOI: 10.1016/j.ajo.2019.01.024] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Revised: 01/22/2019] [Accepted: 01/24/2019] [Indexed: 10/27/2022]
Abstract
PURPOSE To ascertain the incidence of Acanthamoeba keratitis and the coexistence of Acanthamoeba and fungi in microbial keratitis. DESIGN Prospective cross-sectional study. METHODS Patients presenting with stromal keratitis were additionally tested for Acanthamoeba irrespective of the clinical diagnosis. Culture positivity was the gold standard. RESULTS Of the 401 cases included in the study, 40 were positive for Acanthamoeba (10%); of these 40, 16 were positive for both Acanthamoeba and fungi (4.5% of the study group was Acanthamoeba and fungal keratitis positive); 5 were positive for Acanthamoeba and bacteria; and 2 had triple infection with Acanthamoeba, fungi, and bacteria. Ring infiltrates and stromal edema are frequently associated with Acanthamoeba keratitis, as well as in Acanthamoeba coinfections. Ring infiltrates in particular were more frequently seen in the Acanthamoeba and fungal keratitis group (8/16) and they were often yellowish with hyphate edges (vs ring infiltrates only, which are seen in the patients with Acanthamoeba alone). Only 2 patients were contact lens wearers: however, they presented with history of trauma. CONCLUSIONS Acanthamoeba coinfections are much more frequent and are not restricted to contact lens users. Anticipating coinfections is necessary for establishing a diagnosis as well as for appropriate and timely therapeutic interventions.
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Joseph J, Chaurasia S, Sharma S. Case Report: Corneal Coinfection with Fungus and Amoeba: Report of Two Patients and Literature Review. Am J Trop Med Hyg 2018; 99:805-808. [PMID: 30014813 DOI: 10.4269/ajtmh.18-0158] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
We report two cases of corneal coinfection with Acanthamoeba and Fusarium sp. along with the review of published literature. A 35-year-old woman and 65-year-old man presented to the institute with corneal ulcer refractory for treatment with topical antibiotics. Microbiological examination revealed the presence of Acanthamoeba cysts along with septate, hyaline fungal filaments. After emergency therapeutic penetrating keratoplasty (TPK) in both, the corneal tissue was sent for histopathologic examination, which confirmed the presence of Acanthamoeba and fungal coinfection. One patient had a recurrence of fungal infection after TPK. In subjects with a rapid progression of mycotic ulcer, coinfection with other microorganisms including Acanthamoeba should be suspected. The two cases presented here emphasize the importance of microbiology in making prompt diagnosis and appropriate management of these cases at an early stage.
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Affiliation(s)
- Joveeta Joseph
- Jhaveri Microbiology Centre, Brien Holden Eye Research Centre, L. V. Prasad Eye Institute, Hyderabad, India
| | - Sunita Chaurasia
- Tej Kohli Cornea Institute, L. V. Prasad Eye Institute, Hyderabad, India
| | - Savitri Sharma
- Jhaveri Microbiology Centre, Brien Holden Eye Research Centre, L. V. Prasad Eye Institute, Hyderabad, India
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Diagnostic Evaluation of Co-Occurrence of Acanthamoeba and Fungi in Keratitis: A Preliminary Report. Cornea 2018; 37:227-234. [PMID: 29111995 DOI: 10.1097/ico.0000000000001441] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
PURPOSE To test the hypothesis that the coexistence of Acanthamoeba with other forms of microbial keratitis, especially fungal keratitis (FK), is more prevalent than suspected. METHODS A prospective diagnostic study whereby patients presenting with stromal keratitis were additionally tested for Acanthamoeba, irrespective of the initial diagnosis. In addition to the routine workup with Gram stain, KOH mount, and cultures on blood agar and potato dextrose agar, nonnutrient agar was included. Confocal microscopy was performed where feasible. Samples for polymerase chain reaction studies were also obtained. We present the preliminary report of the first 100 culture-positive cases. The primary outcome measured was the number of coexistent Acanthamoeba and FK. The secondary outcomes were the total number of Acanthamoeba cases detected and the correlation between clinical diagnosis and microbiological observations. RESULTS Of the first 100 cases, 22 were culture positive for Acanthamoeba, of which 9 were associated with concurrent FK, 5 with bacterial keratitis, and 8 in isolation. However, only 2 cases were diagnosed clinically as Acanthamoeba, whereas 5 were Acanthamoeba suspects. An additional 4 cases of fungal/Acanthamoeba coexistence in keratitis were revealed purely by confocal microscopy. CONCLUSIONS Acanthamoeba can coexist with other forms of microbial keratitis. The frequency of infection coexistent or otherwise is higher than reported, and the possibility of coinfection must be considered especially in unresponsive cases. Including nonnutrient agar and confocal microscopy in all cases of keratitis would perhaps translate into better treatment strategies and outcomes.
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Mauger TF, Kuennen RA, Smith RH, Sawyer W. Acanthamoeba and Stenotrophomonas maltophilia keratitis with fungal keratitis in the contralateral eye. Clin Ophthalmol 2010; 4:1207-9. [PMID: 21060673 PMCID: PMC2964959 DOI: 10.2147/opth.s14507] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Purpose The purpose of this study is to describe the diagnosis, course, and outcome of a case of Acanthamoeba and Stenotrophomonas keratitis with a fungal keratitis in the contralateral eye. Methods A case of Acanthamoeba and Stenotrophomonas keratitis was diagnosed with confocal microscopy and cultures with confocal diagnosis of fungal keratitis in the fellow eye. Results During the initial treatment of the Acanthamoeba and Stenotrophomonas keratitis, the contralateral eye developed a keratitis that demonstrated hyphae in the corneal stroma with confocal microscopy consistent with fungal keratitis. Conclusions Bilateral chronic keratitis cannot be assumed to be caused by the same organism and independent cultures, and confocal microscopy needs to be performed to direct appropriate therapy.
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Affiliation(s)
- Thomas F Mauger
- Department of Ophthalmology, The Ohio State University, Columbus, OH, USA
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Limaiem R, Mnasri H, El Maazi A, Ammari H, Chaabouni A, Mghaieth F, El Matri L. [Severe infectious keratitis in renal transplant patient: a case report]. Nephrol Ther 2009; 5:299-301. [PMID: 19345628 DOI: 10.1016/j.nephro.2009.01.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2008] [Revised: 01/09/2009] [Accepted: 01/11/2009] [Indexed: 11/16/2022]
Abstract
Keratitis occurring in renal transplant patients are often severe, with difficult management. We describe the case of a renal transplant patient, 44 year-old man, with history of recurrent herpetic keratitis, which developed an impending corneal perforation. Conjunctival smear showed the presence of amoebic cysts. Anti-amoebic treatment was undertaken in addition with oral aciclovir, and a therapeutic penetrating keratoplasty was performed. An ulceration of the graft occurred within five months. Ocular samples showed the presence of Candida albicans. Despite aggressive antifungal therapy, he required a second therapeutic penetrating keratoplasty for graft perforation. One month later, we noted a recurrence of the ulcer with corneal thinning which evolved to perforation.
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Affiliation(s)
- Rim Limaiem
- Service B, institut Hedi Rais d'ophtalmologie de Tunis, 4, impasse Tarek Ibn Zied, Mutuelleville, 1082 Tunis, Tunisie.
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Lin HC, Hsiao CH, Ma DHK, Yeh LK, Tan HY, Lin MY, Huang SCM. Medical treatment for combined Fusarium and Acanthamoeba keratitis. Acta Ophthalmol 2009; 87:199-203. [PMID: 18507727 DOI: 10.1111/j.1755-3768.2008.01192.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE Acanthamoeba and fungal keratitis are rare ocular infections. We report cases of combined Fusarium and Acanthamoeba keratitis and the clinical course of medical treatment. METHODS We reviewed the medical records of patients treated for culture-proven Acanthamoeba keratitis at a referral centre, during 2001-2006. RESULTS Eleven consecutive patients were treated for culture-proven Acanthamoeba keratitis during the 5 years, two of whom had combined fungal infections. A 29-year-old man presented with ground-glass corneal oedema and epitheliopathy caused by contact lens use. The other patient, a 7-year-old girl, had eye trauma that led to a feathery corneal infiltrate. Both cases were treated with topical 0.02% polyhexamethylene biguanide (PHMB), 0.1% propamidine, 1% clotrimazole and 5% natamycin. Therapeutic keratoplasty was not required in either case. CONCLUSIONS Timely identification of the pathogen, with repeated culture and smear if necessary, as well as adequate dosage to prevent recurrence is highly recommended in order to preclude the need for therapeutic penetrating keratoplasty.
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Affiliation(s)
- Hsin-Chiung Lin
- Department of Ophthalmology, Chang Gung Memorial Hospital, Chang Gung University School of Medicine, Taoyuan, Taiwan.
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Abstract
Scedosporium spp. are increasingly recognized as causes of resistant life-threatening infections in immunocompromised patients. Scedosporium spp. also cause a wide spectrum of conditions, including mycetoma, saprobic involvement and colonization of the airways, sinopulmonary infections, extrapulmonary localized infections, and disseminated infections. Invasive scedosporium infections are also associated with central nervous infection following near-drowning accidents. The most common sites of infection are the lungs, sinuses, bones, joints, eyes, and brain. Scedosporium apiospermum and Scedosporium prolificans are the two principal medically important species of this genus. Pseudallescheria boydii, the teleomorph of S. apiospermum, is recognized by the presence of cleistothecia. Recent advances in molecular taxonomy have advanced the understanding of the genus Scedosporium and have demonstrated a wider range of species than heretofore recognized. Studies of the pathogenesis of and immune response to Scedosporium spp. underscore the importance of innate host defenses in protection against these organisms. Microbiological diagnosis of Scedosporium spp. currently depends upon culture and morphological characterization. Molecular tools for clinical microbiological detection of Scedosporium spp. are currently investigational. Infections caused by S. apiospermum and P. boydii in patients and animals may respond to antifungal triazoles. By comparison, infections caused by S. prolificans seldom respond to medical therapy alone. Surgery and reversal of immunosuppression may be the only effective therapeutic options for infections caused by S. prolificans.
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Nulens E, Eggink C, Rijs AJMM, Wesseling P, Verweij PE. Keratitis caused by Scedosporium apiospermum successfully treated with a cornea transplant and voriconazole. J Clin Microbiol 2003; 41:2261-4. [PMID: 12734297 PMCID: PMC154713 DOI: 10.1128/jcm.41.5.2261-2264.2003] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A case of Scedosporium apiospermum keratitis was successfully treated with oral voriconazole and penetrating keratoplasty. Voriconazole levels in the aqueous humor were 53% of the levels in plasma and exceeded the MIC for the isolate by sevenfold.
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Affiliation(s)
- Eric Nulens
- Department of Medical Microbiology, University Medical Center Nijmegen and Nijmegen University Center for Infectious Diseases, The Netherlands.
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Avunduk AM, Beuerman RW, Varnell ED, Kaufman HE. Confocal microscopy of Aspergillus fumigatus keratitis. Br J Ophthalmol 2003; 87:409-10. [PMID: 12642300 PMCID: PMC1771585 DOI: 10.1136/bjo.87.4.409] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AIM To use a confocal microscope to characterise the treated and untreated courses of fungal keratitis. METHODS In the first experiment, Aspergillus fumigatus stromal keratitis was produced in both eyes of seven New Zealand white rabbits. In the second experiment, keratitis was induced in right eyes of 20 rabbits. Group 1 rabbits were treated with topical fluconazole, group 2 rabbits received oral fluconazole, and group 3 rabbits were used as controls. The rabbits were examined with a slit lamp and confocal microscope 2, 6, 10, 14, and 20 days after inoculation. The corneal cultures were taken on days 2, 14, and 20 and biopsies were taken on days 2 and 22. RESULTS On days 14 and 22 confocal microscopy was more sensitive than culture technique in both treated and untreated animals, since not all cases of fungal keratitis can be cultured. CONCLUSION This study indicates that confocal microscopy is a rapid and sensitive diagnostic tool for both the early diagnosis and non-invasive follow up of fungal keratitis
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Affiliation(s)
- A M Avunduk
- Karadeniz Technical University Medical School, Trabzon, Turkey Louisiana State University Eye Center, New Orleans, LA, USA.
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Shah KB, Wu TG, Wilhelmus KR, Jones DB. Activity of voriconazole against corneal isolates of Scedosporium apiospermum. Cornea 2003; 22:33-6. [PMID: 12502945 DOI: 10.1097/00003226-200301000-00008] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To determine the in vitro antifungal activity of voriconazole, a new triazole, compared with other polyene and imidazole antifungal agents against corneal isolates of Scedosporium apiospermum. METHODS Macro-broth dilution susceptibility testing was performed on five isolates of S. apiospermum obtained from patients with keratomycosis to determine the minimal inhibitory concentrations (MICs) for amphotericin B, natamycin, ketoconazole, itraconazole, and voriconazole. The use of oral voriconazole in the management of a patient with posttraumatic S. apiospermum keratitis is described. RESULTS S. apiospermum is generally resistant to commonly used topical ophthalmic antifungal agents. The MIC of voriconazole was 0.5 microg/mL, a concentration lower than that of other imidazoles. CONCLUSION Voriconazole has promising activity against and may prove useful in the management of fungal keratitis.
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Affiliation(s)
- Kekul B Shah
- Sid W. Richardson Ocular Microbiology Laboratory, Cullen Eye Institute, Department of Ophthalmology, Baylor College of Medicine, Houston, Texas, USA
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Wu Z, Ying H, Yiu S, Irvine J, Smith R. Fungal keratitis caused by Scedosporium apiospermum: report of two cases and review of treatment. Cornea 2002; 21:519-23. [PMID: 12072730 DOI: 10.1097/00003226-200207000-00016] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE We report our experience in treating two cases of Scedosporium apiospermum keratitis and provide a review of basic scientific and clinical data regarding the treatment of this visually devastating disease. METHOD We present a case report and literature review. RESULTS A 35-year-old woman and a 73-year-old man both reported pain, redness, and a foreign body sensation in the eye after trauma. They were initially treated with antibacterials. When cultures were positive for S. apiospermum, the first patient was treated with fluconazole and amphotericin with good results. The second was treated with fluconazole and natamycin, but the infection persisted and the eye was eventually enucleated. Review of the literature showed variable responsiveness of S. apiospermum to antifungal treatment. CONCLUSIONS It is difficult to predict how S. apiospermum keratitis will respond to treatment, but miconazole appears to be useful in conjunction with other antifungals. Voriconazole shows promise as an effective alternative.
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Affiliation(s)
- Ziqiang Wu
- Doheny Eye Institute, Keck School of Medicine, University of Southern California, 1450 San Pablo Street, Los Angeles, CA 90033, USA
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