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Qi X, Mao H, Liu J, Dong Y, Du M, Liu T, Zhang T, Lu X, Gao H. Comparison of therapeutic effects between big-bubble deep anterior lamellar keratoplasty and penetrating keratoplasty for medically unresponsive Acanthamoeba keratitis. BMC Infect Dis 2024; 24:276. [PMID: 38438857 PMCID: PMC10910827 DOI: 10.1186/s12879-024-09147-w] [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: 07/31/2023] [Accepted: 02/16/2024] [Indexed: 03/06/2024] Open
Abstract
PURPOSE To compare the outcomes of big-bubble deep anterior lamellar keratoplasty (BB-DALK) and penetrating keratoplasty (PKP) in the management of medically unresponsive Acanthamoeba keratitis (AK). METHODS This retrospective study included 27 eyes of BB-DALK and 24 eyes of PKP from a tertiary ophthalmology care centre. Glucocorticoid eye drops were subsequently added to the treatment plan 2 months postoperatively based on the evaluation using confocal laser scanning microscopy. The clinical presentations, best-corrected visual acuity (BCVA), postoperative refractive outcomes, graft survival, and Acanthamoeba recurrence were analyzed. RESULTS The AK patients included in the study were in stage 2 or stage 3, and the percentage of patients in stage 3 was higher in the PKP group (P = 0.003). Clinical presentations were mainly corneal ulcers and ring infiltrates, and endothelial plaques, hypopyon, uveitis and glaucoma were more common in the PKP group (P = 0.007). The BCVA and the graft survival rate showed no statistically significant differences between the two groups at 1 year after surgery. However, 3 years postoperatively, the BCVA of 0.71 ± 0.64 logMAR, the graft survival rate of 89.5%, and the endothelial cell density of 1899 ± 125 cells per square millimeter in the BB-DALK group were significantly better than those of the PKP group (P = 0.010, 0.046, and 0.032, respectively). 3 eyes (11.1%) in the BB-DALK group and 2 eyes (8.3%) in the PKP group experienced Acanthamoeba recurrence, but the rates showed no statistically significant difference between the two groups (P = 1.000). In the PKP group, immune rejection and elevated intraocular pressure were observed in 5 and 6 eyes, respectively. CONCLUSION Corneal transplantation is recommended for AK patients unresponsive to antiamoebic agents. The visual acuity and graft survival can be maintained after BB-DALK surgery. Acanthamoeba recurrence is not related to the surgical approach performed, whereas complete dissection of the infected corneal stroma and delayed prescribing of glucocorticoid eye drops were important to prevent recurrence.
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Affiliation(s)
- Xiaolin Qi
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, School of Ophthalmology, Eye Institute of Shandong First Medical University, Eye Hospital of Shandong First Medical University (Shandong Eye Hospital), Shandong First Medical University, 372 Jingsi Road, Jinan, 250021, China
| | - Huilin Mao
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, School of Ophthalmology, Eye Institute of Shandong First Medical University, Eye Hospital of Shandong First Medical University (Shandong Eye Hospital), Shandong First Medical University, 372 Jingsi Road, Jinan, 250021, China
| | - Jinhui Liu
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, School of Ophthalmology, Eye Institute of Shandong First Medical University, Eye Hospital of Shandong First Medical University (Shandong Eye Hospital), Shandong First Medical University, 372 Jingsi Road, Jinan, 250021, China
| | - Yanling Dong
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, School of Ophthalmology, Eye Institute of Shandong First Medical University, Qingdao Eye Hospital of Shandong First Medical University, Shandong First Medical University, Jinan, China
| | - Man Du
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, School of Ophthalmology, Eye Institute of Shandong First Medical University, Eye Hospital of Shandong First Medical University (Shandong Eye Hospital), Shandong First Medical University, 372 Jingsi Road, Jinan, 250021, China
| | - Ting Liu
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, School of Ophthalmology, Eye Institute of Shandong First Medical University, Qingdao Eye Hospital of Shandong First Medical University, Shandong First Medical University, Jinan, China
| | - Ting Zhang
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, School of Ophthalmology, Eye Institute of Shandong First Medical University, Qingdao Eye Hospital of Shandong First Medical University, Shandong First Medical University, Jinan, China
| | - Xiuhai Lu
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, School of Ophthalmology, Eye Institute of Shandong First Medical University, Eye Hospital of Shandong First Medical University (Shandong Eye Hospital), Shandong First Medical University, 372 Jingsi Road, Jinan, 250021, China
| | - Hua Gao
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, School of Ophthalmology, Eye Institute of Shandong First Medical University, Eye Hospital of Shandong First Medical University (Shandong Eye Hospital), Shandong First Medical University, 372 Jingsi Road, Jinan, 250021, China.
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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: 9] [Impact Index Per Article: 4.5] [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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Therapeutic Corneal Transplantation in Acanthamoeba Keratitis: Penetrating Versus Lamellar Keratoplasty. Cornea 2021; 41:396-401. [PMID: 34690262 DOI: 10.1097/ico.0000000000002880] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 08/05/2021] [Indexed: 11/26/2022]
Abstract
PURPOSE The purpose of this article was to compare clinical outcomes between therapeutic penetrating keratoplasty (TPK), therapeutic deep anterior lamellar keratoplasty (TDALK), and optical penetrating keratoplasty (OPK) in Acanthamoeba keratitis. METHODS A literature search was conducted in online libraries from 1980 to 2021. The primary end points were best-corrected visual acuity (VA), graft survival, and infection recurrence. In addition, we enrolled 35 consecutive patients with AK from our practice evaluating best-corrected VA and high-order aberrations. RESULTS A total of 359 AK eyes from 33 published studies were retrieved from 175 publications screened. One hundred sixty-five eyes (73%) that underwent TPK and 39 eyes (84%) treated with TDALK had a clear graft at the last follow-up visit. Only the patients treated with OPK had 82 clear grafts (94%) during the follow-up period. Forty-seven (21%) of TPK patients reached VA ≥20/30, compared with 11 (25%) of TDALK patients and 35 (40%) of OPK patients. Acanthamoeba infection recurrence occurred in 38 eyes (16.8%) that underwent TPK, 9 (19%) that underwent TDALK, and 8 (9.5%) that underwent OPK. In our series, best-corrected visual acuity in nonsurgically treated patients was 1 ± 0.50 logMAR compared with 0 logMAR of surgically treated patients. High-order aberrations were significantly lower in surgically treated eyes after AK resolution, particularly in TDALK when compared with TPK patients. Best-corrected visual acuity was better in TDALK patients compared with TPK patients. CONCLUSIONS After AK resolution by 6 to 12 months of medical treatment, OPK seems to be the best surgical choice in patients with AK. If AK could not be eradicated by medical therapy, TDALK may be chosen in the early disease stage and TPK in later stages.
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Peguda HK, Mahbub SB, Sherpa TD, Subedi D, Habibalahi A, Anwer AG, Gu Z, Willcox MDP, Goldys EM, Carnt NA. The Autofluorescence Patterns of Acanthamoeba castellanii, Pseudomonas aeruginosa and Staphylococcus aureus: Effects of Antibiotics and Tetracaine. Pathogens 2021; 10:pathogens10070894. [PMID: 34358044 PMCID: PMC8308758 DOI: 10.3390/pathogens10070894] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 07/10/2021] [Accepted: 07/12/2021] [Indexed: 11/28/2022] Open
Abstract
Acanthamoeba Keratitis (AK) can lead to substantial vision loss and morbidity among contact lens wearers. Misdiagnosis or delayed diagnosis is a major factor contributing to poor outcomes of AK. This study aimed to assess the effect of two antibiotics and one anaesthetic drug used in the diagnosis and nonspecific management of keratitis on the autofluorescence patterns of Acanthamoeba and two common bacteria that may also cause keratitis. Acanthamoeba castellanii ATCC 30868, Pseudomonas aeruginosa ATCC 9027, and Staphylococcus aureus ATCC 6538 were grown then diluted in either PBS (bacteria) or ¼ strength Ringer’s solution (Acanthamoeba) to give final concentrations of 0.1 OD at 660 nm or 104 cells/mL. Cells were then treated with ciprofloxacin, tetracycline, tetracaine, or no treatment (naïve). Excitation–emission matrices (EEMs) were collected for each sample with excitation at 270–500 nm with increments in 5 nm steps and emission at 280–700 nm at 2 nm steps using a Fluoromax-4 spectrometer. The data were analysed using MATLAB software to produce smoothed color-coded images of the samples tested. Acanthamoeba exhibited a distinctive fluorescence pattern compared to bacteria. The addition of antibiotics and anaesthetic had variable effects on autofluorescence. Tetracaine altered the fluorescence of all three microorganisms, whereas tetracycline did not show any effect on the fluorescence. Ciprofloxacin produced changes to the fluorescence pattern for the bacteria, but not Acanthamoeba. Fluorescence spectroscopy was able to differentiate Acanthamoeba from P. aeruginosa and S. aureus in vitro. There is a need for further assessment of the fluorescence pattern for different strains of Acanthamoeba and bacteria. Additionally, analysis of the effects of anti-amoebic drugs on the fluorescence pattern of Acanthamoeba and bacteria would be prudent before in vivo testing of the fluorescence diagnostic approach in the animal models.
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Affiliation(s)
- Hari Kumar Peguda
- School of Optometry and Vision Science, University of New South Wales, Sydney 2052, Australia; (T.D.S.); (D.S.); (M.D.P.W.); (N.A.C.)
- Correspondence:
| | - Saabah B. Mahbub
- ARC Centre of Excellence for Nanoscale Biophotonics, Graduate School of Biomedical Engineering, University of New South Wales, Sydney 2052, Australia; (S.B.M.); (A.H.); (A.G.A.); (E.M.G.)
| | - Tashi Doma Sherpa
- School of Optometry and Vision Science, University of New South Wales, Sydney 2052, Australia; (T.D.S.); (D.S.); (M.D.P.W.); (N.A.C.)
| | - Dinesh Subedi
- School of Optometry and Vision Science, University of New South Wales, Sydney 2052, Australia; (T.D.S.); (D.S.); (M.D.P.W.); (N.A.C.)
- School of Biological Sciences, Monash University, Clayton 3800, Australia
| | - Abbas Habibalahi
- ARC Centre of Excellence for Nanoscale Biophotonics, Graduate School of Biomedical Engineering, University of New South Wales, Sydney 2052, Australia; (S.B.M.); (A.H.); (A.G.A.); (E.M.G.)
| | - Ayad G. Anwer
- ARC Centre of Excellence for Nanoscale Biophotonics, Graduate School of Biomedical Engineering, University of New South Wales, Sydney 2052, Australia; (S.B.M.); (A.H.); (A.G.A.); (E.M.G.)
| | - Zi Gu
- School of Chemical Engineering, University of New South Wales, Sydney 2052, Australia;
| | - Mark D. P. Willcox
- School of Optometry and Vision Science, University of New South Wales, Sydney 2052, Australia; (T.D.S.); (D.S.); (M.D.P.W.); (N.A.C.)
| | - Ewa M. Goldys
- ARC Centre of Excellence for Nanoscale Biophotonics, Graduate School of Biomedical Engineering, University of New South Wales, Sydney 2052, Australia; (S.B.M.); (A.H.); (A.G.A.); (E.M.G.)
| | - Nicole A. Carnt
- School of Optometry and Vision Science, University of New South Wales, Sydney 2052, Australia; (T.D.S.); (D.S.); (M.D.P.W.); (N.A.C.)
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Shi L, Fries FN, Xanthopoulou K, Stachon T, Daas L, Zemova E, Langenbucher A, Seitz B, Szentmáry N. Endothelial Cell Density and Central Corneal Thickness following Penetrating Keratoplasty of Acanthamoeba Keratitis Patients - A Retrospective Cross-Sectional Observational Study. Klin Monbl Augenheilkd 2021; 239:1007-1012. [PMID: 33733447 DOI: 10.1055/a-1353-5171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
PURPOSE To analyze endothelial cell density (ECD) and central corneal thickness (CCT) following penetrating keratoplasty (PKP) in Acanthamoeba keratitis (AK) patients. PATIENTS AND METHODS In this retrospective, clinical, single-center, cross-sectional, observational study, patients were enrolled who underwent PKP at the Department of Ophthalmology of Saarland University Medical Center, Homburg/Saar, Germany between May 2008 and December 2016 with the diagnosis of AK. In all, 33 eyes of 33 patients (14 males, 42%) were enrolled; their mean age at the time of surgery was 39.5 ± 14.3 years. Postoperatively, AK patients received topical polyhexamethylene biguanide, propamidine isethionate, neomycin sulphate/gramicidin/polymixin B sulfate, and prednisolone acetate eye drops (5 ×/day each), and the topical treatment was tapered sequentially with 1 drop every 6 weeks over 6 months. CCT was recorded using Pentacam HR Scheimpflug tomography and ECD with the EM-3000 specular microscope before surgery and 3 and 6 months after surgery as well as after the first and second (complete) suture removal. RESULTS ECD tended to decrease significantly from the time point before surgery (2232 ± 296 cells/mm2) to the time point 3 months after surgery (1914 ± 164 cells/mm2; p = 0.080) and to the time point after the first suture removal (1886 ± 557 cells/mm2; p = 0.066) and decrease significantly to the time point after the second suture removal (1650 ± 446 cells/mm2; p = 0.028). CCT did not change significantly over the analyzed time period (p ≥ 0.475). CONCLUSION In AK, endothelial cell loss does not seem to be accelerated following PKP, despite the postoperative use of diamidine and biguanide. A subsequent prospective comparative study should confirm our retrospective longitudinal analysis.
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Affiliation(s)
- Lei Shi
- Dr Rolf M. Schwiete Center for Limbal Stem Cell and Congenital Aniridia Research, Saarland University, Homburg/Saar, Germany.,Department of Ophthalmology, The First Affiliated Hospital of University of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Fabian Norbert Fries
- Department of Ophthalmology, Saarland University Medical Center, Homburg/Saar, Germany
| | | | - Tanja Stachon
- Dr Rolf M. Schwiete Center for Limbal Stem Cell and Congenital Aniridia Research, Saarland University, Homburg/Saar, Germany
| | - Loay Daas
- Department of Ophthalmology, Saarland University Medical Center, Homburg/Saar, Germany
| | - Elena Zemova
- Department of Ophthalmology, Saarland University Medical Center, Homburg/Saar, Germany
| | - Achim Langenbucher
- Institut für Experimentelle Ophthalmologie, Universität des Saarlandes, Homburg/Saar, Germany
| | - Berthold Seitz
- Department of Ophthalmology, Saarland University Medical Center, Homburg/Saar, Germany
| | - Nóra Szentmáry
- Dr Rolf M. Schwiete Center for Limbal Stem Cell and Congenital Aniridia Research, Saarland University, Homburg/Saar, Germany.,Department of Ophthalmology, Semmelweis University, Budapest, Hungary
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Evaluation of Acanthamoeba keratitis cases in a tertiary medical care centre over 21 years. Sci Rep 2021; 11:1036. [PMID: 33441799 PMCID: PMC7806847 DOI: 10.1038/s41598-020-80222-3] [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: 06/25/2020] [Accepted: 12/17/2020] [Indexed: 01/29/2023] Open
Abstract
To report on Acanthamoeba keratitis cases in a tertiary university eye-hospital in Graz, Austria, over a 21-year period. Retrospective study. Parameters included demographics, diagnostics, clinical courses, medical therapies, surgical interventions, secondary complications, and best spectacle-corrected visual acuity (BSCVA). Patient records for 44 eyes of 42 patients were analysed; 2 bilateral infections. Mean age at presentation was 31 ± 13 (16-65) years; contact lenses were used in 41 of 44 eyes (93.2%). Symptoms at initial presentation were mainly pain (41/43, 95.3%) and photophobia (16/43, 37.2%). Most frequent morphological findings were stromal infiltrates (30/44, 68.2%). Diagnosis was mainly confirmed by smears (40/42, 95.2%) and polymerase chain reaction (8/42, 19%). Antiamoebic treatment comprised biguanides and diamidines. Penetrating keratoplasty was performed in 10/44 (22.7%) eyes. Median time from symptom onset to initial visit was 2 (0-26) weeks; median follow-up was 30 (2-1008) weeks. BSCVA improved in 23/36 (63.9%) eyes, remained unchanged in 6/36 (16.7%) eyes and deteriorated in 7/36 (19.4%) eyes. Acanthamoeba keratitis predominantly occurs in young contact lens wearers. Diagnosis should be considered in patients with pain and stromal infiltrates. In the majority of cases, BSCVA can be improved. Early diagnosis and adequate treatment should be implemented to prevent complications.
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Lacerda AG, Lira M. Acanthamoeba
keratitis: a review of biology, pathophysiology and epidemiology. Ophthalmic Physiol Opt 2020; 41:116-135. [DOI: 10.1111/opo.12752] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 09/07/2020] [Accepted: 09/09/2020] [Indexed: 01/13/2023]
Affiliation(s)
| | - Madalena Lira
- Centre of Physics University of Minho Braga Portugal
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Magistrado-Coxen P, Aqeel Y, Lopez A, Haserick JR, Urbanowicz BR, Costello CE, Samuelson J. The most abundant cyst wall proteins of Acanthamoeba castellanii are lectins that bind cellulose and localize to distinct structures in developing and mature cyst walls. PLoS Negl Trop Dis 2019; 13:e0007352. [PMID: 31095564 PMCID: PMC6541295 DOI: 10.1371/journal.pntd.0007352] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 05/29/2019] [Accepted: 04/01/2019] [Indexed: 12/02/2022] Open
Abstract
Background Acanthamoeba castellanii, which causes keratitis and blindness in under-resourced countries, is an emerging pathogen worldwide, because of its association with contact lens use. The wall makes cysts resistant to sterilizing reagents in lens solutions and to antibiotics applied to the eye. Methodology/Principal findings Transmission electron microscopy and structured illumination microscopy (SIM) showed purified cyst walls of A. castellanii retained an outer ectocyst layer, an inner endocyst layer, and conical ostioles that connect them. Mass spectrometry showed candidate cyst wall proteins were dominated by three families of lectins (named here Jonah, Luke, and Leo), which bound well to cellulose and less well to chitin. An abundant Jonah lectin, which has one choice-of-anchor A (CAA) domain, was made early during encystation and localized to the ectocyst layer of cyst walls. An abundant Luke lectin, which has two carbohydrate-binding modules (CBM49), outlined small, flat ostioles in a single-layered primordial wall and localized to the endocyst layer and ostioles of mature walls. An abundant Leo lectin, which has two unique domains with eight Cys residues each (8-Cys), localized to the endocyst layer and ostioles. The Jonah lectin and glycopolymers, to which it binds, were accessible in the ectocyst layer. In contrast, Luke and Leo lectins and the glycopolymers, to which they bind, were mostly inaccessible in the endocyst layer and ostioles. Conclusions/Significance The most abundant A. castellanii cyst wall proteins are three sets of lectins, which have carbohydrate-binding modules that are conserved (CBM49s of Luke), newly characterized (CAA of Jonah), or unique to Acanthamoebae (8-Cys of Leo). Cyst wall formation is a tightly choreographed event, in which lectins and glycopolymers combine to form a mature wall with a protected endocyst layer. Because of its accessibility in the ectocyst layer, an abundant Jonah lectin is an excellent diagnostic target. A half century ago, investigators identified cellulose in the Acanthamoeba cyst wall, which has two layers and conical ostioles that connect them. Here we showed cyst walls contain three large sets of cellulose-binding lectins, which localize to the ectocyst layer (a Jonah lectin) or to the endocyst layer and ostioles (Luke and Leo lectins). We used the lectins to establish a sequence for cyst wall assembly when trophozoites are starved and encyst. In the first stage, a Jonah lectin and glycopolymers were present in dozens of distinct vesicles. In the second stage, a primordial wall contained small, flat ostioles outlined by a Luke lectin. In the third stage, a Jonah lectin remained in the ectocyst layer, while Luke and Leo lectins moved to the endocyst layer and ostioles. A description of the major events during cyst wall development is a starting point for mechanistic studies of its assembly.
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Affiliation(s)
- Pamela Magistrado-Coxen
- Department of Molecular and Cell Biology, Boston University Goldman School of Dental Medicine, Boston, Massachusetts, United States of America
| | - Yousuf Aqeel
- Department of Molecular and Cell Biology, Boston University Goldman School of Dental Medicine, Boston, Massachusetts, United States of America
| | - Angelo Lopez
- Department of Molecular and Cell Biology, Boston University Goldman School of Dental Medicine, Boston, Massachusetts, United States of America
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - John R. Haserick
- Department of Molecular and Cell Biology, Boston University Goldman School of Dental Medicine, Boston, Massachusetts, United States of America
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Breeanna R. Urbanowicz
- Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia, United States of America
| | - Catherine E. Costello
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - John Samuelson
- Department of Molecular and Cell Biology, Boston University Goldman School of Dental Medicine, Boston, Massachusetts, United States of America
- * E-mail:
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Liu HY, Chu HS, Wang IJ, Chen WL, Hou YC, Hu FR. Clinical features and outcomes of Acanthamoeba keratitis in a tertiary hospital over 20- year period. J Formos Med Assoc 2019; 119:211-217. [PMID: 31076316 DOI: 10.1016/j.jfma.2019.04.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 04/15/2019] [Accepted: 04/18/2019] [Indexed: 11/29/2022] Open
Abstract
PURPOSE To analyze the outcomes of Acanthamoeba keratitis (AK) in terms of different clinical presentations in a tertiary hospital in Taiwan over a 20- year period. METHODS This is a retrospective case series. Patients with AK diagnosed at the National Taiwan University Hospital between January 1996 and December 2015 were identified. A diagnosis of AK was made on the basis of positive Acanthamoeba smear/cultures or pathological identification of Acanthamoeba cysts on keratoplasty specimens. Patient demographics, clinical presentations, treatment courses, and final visual outcomes were collected and analyzed. Visual acuity, postoperative complications and graft survivals were measured as outcomes. RESULTS Of the 62 patients with AK in our study, 64.5% were medically treated while 35.5% underwent surgical treatment. In those with ring infiltrate, 52.4% patients could be successfully treated with medications. In eyes receiving penetrating keratoplasty, postoperative complications were more common in therapeutic penetrating keratoplasty (TPK) than those in optical penetrating keratoplasty (OPK) group (82.4% versus 40%, p = 0.04). The graft size was larger in TPK than that in OPK group (8.56 versus 7.83 mm, p = 0.002). Furthermore, post-operative glaucoma, which was the major complication, was found to be associated with larger graft size (p = 0.02) and dilated pupil/iris atrophy (p = 0.01). CONCLUSION Even in advanced cases with ring infiltrate, eradication of infection with anti-amoebic drugs is possible. In those requiring keratoplasty, the surgical timing should be made meticulously considering graft size and signs of dilated pupil/iris atrophy in terms of post-operative glaucoma.
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Affiliation(s)
- Hsin-Yu Liu
- Department of Ophthalmology, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Hsiao-Sang Chu
- Department of Ophthalmology, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - I-Jong Wang
- Department of Ophthalmology, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Wei-Li Chen
- Department of Ophthalmology, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Yu-Chih Hou
- Department of Ophthalmology, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Fung-Rong Hu
- Department of Ophthalmology, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan.
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Wang M, Sun G, Sun Y, You X, Li X, Cheng Y, Xuan Y. Identification and Genotypic Characterization of Potentially Pathogenic Acanthamoeba Isolated from Tap Water in Wuxi, China. THE KOREAN JOURNAL OF PARASITOLOGY 2019; 56:615-618. [PMID: 30630284 PMCID: PMC6327204 DOI: 10.3347/kjp.2018.56.6.615] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Accepted: 11/05/2018] [Indexed: 11/23/2022]
Abstract
Members of genus Acanthamoeba are widely distributed in the environment. Some are pathogenic and cause keratitis and fatal granulomatous amoebic encephalitis. In this study, we isolated an Acanthamoeba CJW/W1 strain from tap water in Wuxi, Jiangsu Province, China. Its 18S rDNA was sequenced and a phylogenetic tree was constructed. The isolated cysts belonged to morphologic group II. Comparison of 18S rDNA sequences of CJW/W1 strain and other isolates showed high similarity (99.7%) to a clinical isolate Asp, KA/E28. A phylogeny analysis confirmed this isolate belonged to the pathogenic genotype T4, the most common strain associated with Acanthamoeba-related diseases. This is the first report of an Acanthamoeba strain isolated from tap water in Wuxi, China. Acanthamoeba could be a public health threat to the contact lens wearers and, therefore, its prevalence should be monitored.
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Affiliation(s)
- Meixu Wang
- Department of Public Health and Preventive Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu, 214122, P.R. China
| | - Guangxu Sun
- Department of Public Health and Preventive Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu, 214122, P.R. China
| | - Yangkai Sun
- Department of Public Health and Preventive Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu, 214122, P.R. China
| | - Xiaomin You
- Department of Public Health and Preventive Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu, 214122, P.R. China
| | - Xiaoxue Li
- Department of Public Health and Preventive Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu, 214122, P.R. China
| | - Yang Cheng
- Department of Public Health and Preventive Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu, 214122, P.R. China
| | - Yinghua Xuan
- Department of Public Health and Preventive Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu, 214122, P.R. China.,Public Health Research Center, Jiangnan University, Wuxi, Jiangsu, 214122, P.R. China
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