Reference Citation Analysis: Find an Article, Find a Category, Find a Journal, Find a Scholar

For: dos Santos DL, Kwitko S, Marinho DR, de Araújo BS, Locatelli CI, Rott MB. Acanthamoeba keratitis in Porto Alegre (southern Brazil): 28 cases and risk factors. Parasitol Res 2018;117:747-50. [DOI: 10.1007/s00436-017-5745-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 12/29/2017] [Indexed: 10/18/2022]

For:	dos Santos DL, Kwitko S, Marinho DR, de Araújo BS, Locatelli CI, Rott MB. Acanthamoeba keratitis in Porto Alegre (southern Brazil): 28 cases and risk factors. Parasitol Res 2018;117:747-50. [DOI: 10.1007/s00436-017-5745-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 12/29/2017] [Indexed: 10/18/2022]

Number

Cited by Other Article(s)

Aiello F, Gallo Afflitto G, Ceccarelli F, Turco MV, Han Y, Amescua G, Dart JK, Nucci C. Perspectives on the Incidence of Acanthamoeba Keratitis: A Systematic Review and Meta-Analysis. Ophthalmology 2025;132:206-218. [PMID: 39127408 DOI: 10.1016/j.ophtha.2024.08.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2024] [Revised: 07/30/2024] [Accepted: 08/02/2024] [Indexed: 08/12/2024] Open

Abstract

TOPIC

To provide an overview on the incidence of Acanthamoeba keratitis (AK).

CLINICAL RELEVANCE

Although being a sight-threatening cause of infectious keratitis, a comprehensive assessment of the incidence of AK is lacking.

METHODS

Incidence of AK was computed as the number of eyes with AK per health care center, per year (annualized center incidence [ACI]). Two meta-analytical ratios also were calculated: (1) the ratio of eyes with AK to the count of eyes with nonviral microbial keratitis (MK) and (2) the ratio of eyes with AK to the overall population (i.e., the total number of people in a nation or region, as indicated by the authors in each study). Center was defined as the health care facility where the study took place. Actual and projected estimates of the number of eyes with AK in years were calculated multiplying the ratio of eyes with AK to the total population and the corresponding population estimates, sourced from the United Nations Population Prospects.

RESULTS

Overall, 105 articles were included, published between 1987 and 2022. The total number of eyes identified was 91 951, with 5660 eyes affected by AK and 86 291 eyes affected by nonviral MK. The median ACI was 1.9 eyes with AK per health care center per year (95% confidence interval [CI], 1.5-2.6 eyes), with no statistically significant differences among continents. The ratio of eyes with AK to the total number of eyes with MK was 1.52% (95% CI, 1.03%-2.22%), whereas the ratio of eyes with AK in relationship to the entire population was estimated at 2.34 eyes per 1 000 000 people (95% CI, 0.98-5.55 per 1 000 000 people). The projected increase in the numbers of eyes with AK indicated an increase of 18.5% (n = 15 355 eyes with AK) in 2053 and 25.5% (n = 16 253 eyes with AK) in 2073, compared with the baseline of 2023 (n = 12 953 eyes with AK).

DISCUSSION

Acanthamoeba keratitis emerged as a relatively low-incident disorder, and no significant differences in terms of its incidence were found among different continents.

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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Akhlaghi E, Shafa S, Akbari Z, Babaei Z, Mohammadi MA, Shamsaddini S, Sharifi A, Harandi MF. Identification and Characterization of Acanthamoeba from Contact Lens Care Solutions and Hospital Environments in the Ophthalmology Wards and Operating Rooms in Southeastern Iran. Acta Parasitol 2025;70:12. [PMID: 39775293 DOI: 10.1007/s11686-024-00948-2] [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: 09/15/2024] [Accepted: 12/16/2024] [Indexed: 01/11/2025]

Abstract

OBJECTIVE

Different Acanthamoeba species are among the most ubiquitous organisms causing serious diseases in humans including central nervous system (CNS) and eye infections. Contact lenses, lens care solutions and the hospital environments particularly the indoor and outdoor environments of ophthalmology wards where people are present with different types of eye diseases, are the potential sources of human infection. The purpose of the present study was the molecular investigation of free-living amoebae in the used contact lenses, lens care solutions and hospital samples from the ophthalmology wards and operating rooms in a referral hospital in southeastern Iran.

METHODS

Samples were collected from the lens care solutions, used contact lenses, and from indoor and outdoor environments of the ophthalmology ward and operating room of a major referral hospital in Kerman, Southeastern Iran. The samples were cultured on non-nutrient agar (NNA) in 28-30oC and microscopically studied. Molecular study including PCR-sequencing and phylogenetic analysis on partial 18 S rDNA were performed on positive culture samples.

RESULT

In total 70 samples were collected from the used contact lenses and lens care solutions, as well as the hospital environment of which 11.4% (8 out of 70) were found positive using NNA culture. Two out of 40 samples (5.0%) from the used contact lenses and the care solutions were found positive for the presence of Acanthamoeba T4 genotype. Acanthamoeba cysts were identified in two out of 22 dust samples (9.1%) collected from the ophthalmology ward and operating rooms. Protacanthamoeba bohemica was found in the soil samples from outdoor environment of the ophthalmology ward.

CONCLUSION

This study identified Acanthamoeba species in contact lenses and in indoor environmental samples from the ophthalmology ward. T4 genotype was found on the contact lenses examined in this study. In the dust sampled from within the ophthalmology ward Acanthamoeba sp. was identified.

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Sundararaj BK, Goyal M, Samuelson J. Identification of new targets for the diagnosis of cysts (four) and trophozoites (one) of the eye pathogen Acanthamoeba. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.10.16.618517. [PMID: 39463995 PMCID: PMC11507896 DOI: 10.1101/2024.10.16.618517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/29/2024]

Abstract

Acanthamoebae , which are free-living amoebae, cause corneal inflammation (keratitis) and blindness, if not diagnosed and effectively treated. While trophozoites adhere to and damage the cornea, Acanthamoeba cysts, the walls of which contain cellulose and have two layers connected by conical ostioles, are the diagnostic form by microscopy of the eye or of corneal scrapings. We recently used structural and experimental methods to characterize cellulose-binding domains of Luke and Leo lectins, which are abundant in the inner layer and ostioles. However, no antibodies have been made to these lectins or to a Jonah lectin and a laccase, which are abundant in the outer layer. Here we used confocal microscopy to show that rabbit antibodies to recombinant Luke, Leo, Jonah, and laccase generally support localizations of GFP-tagged proteins in walls of transfected Acanthamoebae. Rabbit antibodies to all four wall proteins efficiently detected calcofluor white-labeled cysts of 10 of 11 Acanthamoeba isolates obtained from the ATCC, including five T4 genotypes that cause most cases of keratitis. Laccase shed into the medium during encystation was detected by an enzyme-linked immunoassay. We also used structural and experimental methods to characterize the mannose-binding domain of an Acanthamoeba mannose-binding protein and showed that rabbit antibodies to the mannose-binding domain efficiently detected trophozoites of all 11 Acanthamoeba isolates. We conclude that four wall proteins are all excellent targets for diagnosing Acanthamoeba cysts in the eye or corneal scrapings, while the mannose-binding domain is an excellent target for identifying trophozoites in cultures of corneal scrapings.

Importance

Free-living amoeba in the soil or water cause Acanthamoeba keratitis, which is diagnosed by identification of cysts by microscopy of the eye or of corneal scrapings, using calcofluor-white that unfortunately cross-reacts with fungi and plants. Alternatively, Acanthamoeba infections are diagnosed by identification of trophozoites in cultures of scrapings. Here we showed that rabbit antibodies to four abundant cyst wall proteins (Jonah, Luke, Leo, and laccase) each efficiently detect calcofluor-white-labeled cysts of 10 of 11 Acanthamoeba isolates obtained from the ATCC. Further, laccase released into the medium by encysting Acanthamoebae was detected by an enzyme-linked immunoassay. We also showed that rabbit antibodies to the mannose-binding domain of the Acanthamoeba mannose-binding protein, which mediates adherence of trophozoites to keratinocytes, efficiently identifies trophozoites of all 11 ATCC isolates. In summary, four wall proteins and the ManBD appear to be excellent targets for diagnosis of Acanthamoeba cysts and trophozoites, respectively.

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Kanakapura Sundararaj B, Goyal M, Samuelson J. Cellulose binding and the timing of expression influence protein targeting to the double-layered cyst wall of Acanthamoeba. mSphere 2024;9:e0046624. [PMID: 39136454 PMCID: PMC11423589 DOI: 10.1128/msphere.00466-24] [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: 05/29/2024] [Accepted: 07/22/2024] [Indexed: 09/26/2024] Open

Abstract

The cyst wall of the eye pathogen Acanthamoeba castellanii contains cellulose and has ectocyst and endocyst layers connected by conical ostioles. Cyst walls contain families of lectins that localize to the ectocyst layer (Jonah) or the endocyst layer and ostioles (Luke and Leo). How lectins and an abundant laccase bind cellulose and why proteins go to locations in the wall are not known and are the focus of the studies here. Structural predictions identified β-jelly-roll folds (BJRFs) of Luke and sets of four disulfide knots (4DKs) of Leo, each of which contains linear arrays of aromatic amino acids, also present in carbohydrate-binding modules of bacterial and plant endocellulases. Ala mutations showed that these aromatics are necessary for cellulose binding and proper localization of Luke and Leo in the Acanthamoeba cyst wall. BJRFs of Luke, 4DKs of Leo, a single β-helical fold (BHF) of Jonah, and a copper oxidase domain of the laccase each bind to glycopolymers in both layers of deproteinated cyst walls. Promoter swaps showed that ectocyst localization does not just correlate with but is caused by early encystation-specific expression, while localization in the endocyst layer and ostioles is caused by later expression. Evolutionary studies showed distinct modes of assembly of duplicated domains in Luke, Leo, and Jonah lectins and suggested Jonah BHFs originated from bacteria, Luke BJRFs share common ancestry with slime molds, while 4DKs of Leo are unique to Acanthamoeba.IMPORTANCEAcanthamoebae is the only human parasite with cellulose in its cyst wall and conical ostioles that connect its inner and outer layers. Cyst walls are important virulence factors because they make Acanthamoebae resistant to surface disinfectants, hand sanitizers, contact lens sterilizers, and antibiotics applied to the eye. The goal here was to understand better how proteins are targeted to specific locations in the cyst wall. To this end, we identified three new proteins in the outer layer of the cyst wall, which may be targets for diagnostic antibodies in corneal scrapings. We used structural predictions and mutated proteins to show linear arrays of aromatic amino acids of two unrelated wall proteins are necessary for binding cellulose and proper wall localization. We showed early expression during encystation causes proteins to localize to the outer layer, while later expression causes proteins to localize to the inner layer and the ostioles.

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Musa M, Enaholo E, Aluyi-Osa G, Atuanya GN, Spadea L, Salati C, Zeppieri M. Herpes simplex keratitis: A brief clinical overview. World J Virol 2024;13:89934. [PMID: 38616855 PMCID: PMC11008405 DOI: 10.5501/wjv.v13.i1.89934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 12/28/2023] [Accepted: 01/22/2024] [Indexed: 03/11/2024] Open

Abstract

The aim of our minireview is to provide a brief overview of the diagnosis, clinical aspects, treatment options, management, and current literature available regarding herpes simplex keratitis (HSK). This type of corneal viral infection is caused by the herpes simplex virus (HSV), which can affect several tissues, including the cornea. One significant aspect of HSK is its potential to cause recurrent episodes of inflammation and damage to the cornea. After the initial infection, the HSV can establish a latent infection in the trigeminal ganglion, a nerve cluster near the eye. The virus may remain dormant for extended periods. Periodic reactivation of the virus can occur, leading to recurrent episodes of HSK. Factors triggering reactivation include stress, illness, immunosuppression, or trauma. Recurrent episodes can manifest in different clinical patterns, ranging from mild epithelial involvement to more severe stromal or endothelial disease. The severity and frequency of recurrences vary among individuals. Severe cases of HSK, especially those involving the stroma and leading to scarring, can result in vision impairment or even blindness in extreme cases. The cornea's clarity is crucial for good vision, and scarring can compromise this, potentially leading to visual impairment. The management of HSK involves not only treating acute episodes but also implementing long-term strategies to prevent recurrences and attempt repairs of corneal nerve endings via neurotization. Antiviral medications, such as oral Acyclovir or topical Ganciclovir, may be prescribed for prophylaxis. The immune response to the virus can contribute to corneal damage. Inflammation, caused by the body's attempt to control the infection, may inadvertently harm the corneal tissues. Clinicians should be informed about triggers and advised on measures to minimize the risk of reactivation. In summary, the recurrent nature of HSK underscores the importance of both acute and long-term management strategies to preserve corneal health and maintain optimal visual function.

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Dos Santos DL, Chaúque BJM, Matiazo FF, de Miranda Ribeiro L, Rott MB. Agar dehydration: a simple method for long-term storage of Acanthamoeba spp. collection at room temperature. Parasitol Res 2024;123:153. [PMID: 38446221 DOI: 10.1007/s00436-024-08172-7] [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: 01/12/2024] [Accepted: 02/26/2024] [Indexed: 03/07/2024]

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

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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Chaúque BJM, da Silva TCB, Dos Santos DL, Benitez GB, Chaúque LGH, Benetti AD, Zanette RA, Rott MB. Global prevalence of free-living amoebae in solid matrices - A systematic review with meta-analysis. Acta Trop 2023;247:107006. [PMID: 37633571 DOI: 10.1016/j.actatropica.2023.107006] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 08/18/2023] [Accepted: 08/21/2023] [Indexed: 08/28/2023]

Abstract

The ubiquitous free-living amoebae (FLA) are microorganisms of significant medical, sanitary, and ecological importance. However, their characterization within solid matrices such as soil, dust, sediment, mud, sludge, and compost remain to be systematized. In this study, we conducted a systematic review with meta-analysis to explore the global distribution of FLA in solid matrices. From the analysis of 104 out of 4,414 scientific articles retrieved from different databases, it was found that the general global prevalence of FLA in solid matrices was of 55.13% (95% confidence interval (CI) 49.32-60.94). Specifically, FLA prevalence was high in soil (72.40%, 95% CI 69.08-75.73), sediment (57.91%, 95% CI 50.01-65.81), mud (52.90%, 95% CI 24.01-81.78), dust (48.60%, 95% CI 43.00-54.19), and sewage sludge (40.19%, 95% CI 30.68-49.70). In aerosols it was comparatively lower (17.21%, 95% CI 12.76-21.66). Acanthamoeba spp. (52.23%) and Hartmanella/Vermamoeba spp. (36.06%) were found to be more prevalent, whereas Naegleria spp. (34.98%) and Balamuthia spp. (27.32%) were less prevalent. The distribution of the highest global prevalence values for species of Acanthamoeba spp., considering different publication periods of the studies, is as follows: A. hatchetti (51.46%), A. rhysodes (47.49%), A. polyphaga (36.37%), A. culbertsoni (34.31%), A. castellanii (34.21%), and A. lenticulata (32.82%). For other FLA species, the distribution is: Hartmannella/Vermamoeba vermiformis (91.57%), Naegleria fowleri (42.32%), Naegleria gruberi (32.39%), and Balamuthia mandrillaris (25%). The most prevalent Acanthamoeba genotypes were T4 (33.38%) and T3 (23.94%). Overall, the global prevalence of FLA in solid matrices is as high as or greater than that reported in water by previous systematic reviews. Thus, actions aimed at reducing exposure to FLA or exploring their ecological dynamics should consider not only water but also the various solid matrices. The finding outlined here can provide valuable insights for such actions, e.g., informing on the level of exposure to FLA, or on the microbial biodiversity of specific environmental compartments.

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Chaúque BJM, Corção G, Benetti AD, Rott MB. A challenge in washing water with the sun: 24h of SODIS fails to inactivate Acanthamoeba castellanii cysts and internalized Pseudomonas aeruginosa under strong real sun conditions. Photochem Photobiol Sci 2023;22:2179-2188. [PMID: 37296325 DOI: 10.1007/s43630-023-00440-2] [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: 02/04/2023] [Accepted: 05/19/2023] [Indexed: 06/12/2023]

Abstract

Despite access to drinking water being a basic human right, the availability of safe drinking water remains a privilege that many do not have and as a result, many lives are lost each year due to waterborne diseases associated with the consumption of biologically unsafe water. To face this situation, different low-cost household drinking water treatment technologies (HDWT) have been developed, and among them is solar disinfection (SODIS). Despite the effectiveness of SODIS and the epidemiological gains being consistently documented in the literature, there is a lack of evidence of the effectiveness of the batch-SODIS process against protozoan cysts as well as their internalized bacteria under real sun conditions. This work evaluated the effectiveness of the batch-SODIS process on the viability of Acanthamoeba castellanii cysts, and internalized Pseudomonas aeruginosa. Dechlorinated tap water contaminated with 5.6 × 103 cysts/L, contained in PET (polyethylene terephthalate) bottles, was exposed for 8 h a day to strong sunlight (531-1083 W/m2 of maximum insolation) for 3 consecutive days. The maximum water temperature inside the reactors ranged from 37 to 50 °C. Cyst viability was assessed by inducing excystment on non-nutrient agar, or in water with heat-inactivated Escherichia coli. After sun exposure for 0, 8, 16 and 24 h, the cysts remained viable and without any perceptible impairment in their ability to excyst. 3 and 5.5 log CFU/mL of P. aeruginosa were detected in water containing untreated and treated cysts, respectively, after 3 days of incubation at 30 °C. The batch-SODIS process is unable to inactivate A. castellanii cysts as well as its internalized bacteria. Although the use of batch SODIS by communities should continue to be encouraged, SODIS-disinfected water should be consumed within 3 days.

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Wang Y, Jiang L, Zhao Y, Ju X, Wang L, Jin L, Fine RD, Li M. Biological characteristics and pathogenicity of Acanthamoeba. Front Microbiol 2023;14:1147077. [PMID: 37089530 PMCID: PMC10113681 DOI: 10.3389/fmicb.2023.1147077] [Citation(s) in RCA: 42] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 03/21/2023] [Indexed: 04/25/2023] Open

Prevalence of free-living amoebae in swimming pools and recreational waters, a systematic review and meta-analysis. Parasitol Res 2022;121:3033-3050. [PMID: 36040629 PMCID: PMC9424809 DOI: 10.1007/s00436-022-07631-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Accepted: 08/16/2022] [Indexed: 11/06/2022]

Abstract

Free-living amoebae (FLA) are cosmopolitan microorganisms known to be pathogenic to humans who often have a history of contact with contaminated water. Swimming pools and recreational waters are among the environments where the greatest human exposure to FLA occurs. This study aimed to determine the prevalence of FLA in swimming pools and recreational waters, through a systematic review and meta-analysis that included studies published between 1977 and 2022. A total of 106 studies were included and an overall prevalence of FLA in swimming pools and recreational waters of 44.34% (95% CI = 38.57–50.18) was found. Considering the studies published up to 2010 (1977–2010), between 2010 and 2015, and those published after 2010 (> 2010–2022), the prevalence was 53.09% (95% CI = 43.33–62.73) and 37.07% (95% CI = 28.87–45.66) and 45.40% (95% CI = 35.48–55.51), respectively. The highest prevalence was found in the American continent (63.99%), in Mexico (98.35%), and in indoor hot swimming pools (52.27%). The prevalence varied with the variation of FLA detection methods, morphology (57.21%), PCR (25.78%), and simultaneously morphology and PCR (43.16%). The global prevalence by genera was Vahlkampfia spp. (54.20%), Acanthamoeba spp. (33.47%), Naegleria spp. (30.95%), Hartmannella spp./Vermamoeba spp. (20.73%), Stenamoeba spp. (12.05%), and Vannella spp. (10.75%). There is considerable risk of FLA infection in swimming pools and recreational waters. Recreational water safety needs to be routinely monitored and, in case of risk, locations need to be identified with warning signs and users need to be educated. Swimming pools and artificial recreational water should be properly disinfected. Photolysis of NaOCl or NaCl in water by UV-C radiation is a promising alternative to disinfect swimming pools and artificial recreational waters.

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Bellini NK, Thiemann OH, Reyes-Batlle M, Lorenzo-Morales J, Costa AO. A history of over 40 years of potentially pathogenic free-living amoeba studies in Brazil - a systematic review. Mem Inst Oswaldo Cruz 2022;117:e210373. [PMID: 35792751 PMCID: PMC9252135 DOI: 10.1590/0074-02760210373] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 03/28/2022] [Indexed: 12/17/2022] Open

Dos Santos DL, Virginio VG, Berté FK, Lorenzatto KR, Marinho DR, Kwitko S, Locatelli CI, Freitas EC, Rott MB. Clinical and molecular diagnosis of Acanthamoeba keratitis in contact lens wearers in southern Brazil reveals the presence of an endosymbiont. Parasitol Res 2022;121:1447-1454. [PMID: 35194678 DOI: 10.1007/s00436-022-07474-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 02/17/2022] [Indexed: 12/17/2022]

Affiliation(s)

Denise Leal Dos Santos Microbiology, Immunology and Parasitology Department, Basic Health Sciences Institute, Parasitology Sector, Rio Grande Do Sul Federal University, Sarmento Leite Street, N 500, Porto Alegre, Rio Grande Do Sul, 90050-170, Brazil
Veridiana Gomes Virginio Microbiology, Immunology and Parasitology Department, Basic Health Sciences Institute, Parasitology Sector, Rio Grande Do Sul Federal University, Sarmento Leite Street, N 500, Porto Alegre, Rio Grande Do Sul, 90050-170, Brazil
Francisco Kercher Berté Microbiology, Immunology and Parasitology Department, Basic Health Sciences Institute, Parasitology Sector, Rio Grande Do Sul Federal University, Sarmento Leite Street, N 500, Porto Alegre, Rio Grande Do Sul, 90050-170, Brazil
Karina Rodrigues Lorenzatto Microbiology, Immunology and Parasitology Department, Basic Health Sciences Institute, Parasitology Sector, Rio Grande Do Sul Federal University, Sarmento Leite Street, N 500, Porto Alegre, Rio Grande Do Sul, 90050-170, Brazil
Diane Ruschel Marinho Cornea Department, Ophthalmology Service, Hospital de Clínicas de Porto Alegre Rio Grande Do Sul, Ramiro Barcelos Street, N 2350, Porto Alegre, Rio Grande Do Sul, 90035-903, Brazil
Sergio Kwitko Cornea Department, Ophthalmology Service, Hospital de Clínicas de Porto Alegre Rio Grande Do Sul, Ramiro Barcelos Street, N 2350, Porto Alegre, Rio Grande Do Sul, 90035-903, Brazil
Claudete Inês Locatelli Cornea Department, Ophthalmology Service, Hospital de Clínicas de Porto Alegre Rio Grande Do Sul, Ramiro Barcelos Street, N 2350, Porto Alegre, Rio Grande Do Sul, 90035-903, Brazil
Eduarda Correa Freitas Cornea Department, Ophthalmology Service, Hospital de Clínicas de Porto Alegre Rio Grande Do Sul, Ramiro Barcelos Street, N 2350, Porto Alegre, Rio Grande Do Sul, 90035-903, Brazil
Marilise Brittes Rott Microbiology, Immunology and Parasitology Department, Basic Health Sciences Institute, Parasitology Sector, Rio Grande Do Sul Federal University, Sarmento Leite Street, N 500, Porto Alegre, Rio Grande Do Sul, 90050-170, Brazil.

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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: 21] [Impact Index Per Article: 5.3] [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

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: 5.4] [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]

Singh K, Bhattacharyya M, Goel A, Arora R, Gotmare N, Aggarwal H. Orthokeratology in Moderate Myopia: A Study of Predictability and Safety. J Ophthalmic Vis Res 2020;15:210-217. [PMID: 32308956 PMCID: PMC7151515 DOI: 10.18502/jovr.v15i2.6739] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 04/16/2019] [Indexed: 11/29/2022] Open

Hewitt MG, Morrison PWJ, Boostrom HM, Morgan SR, Fallon M, Lewis PN, Whitaker D, Brancale A, Varricchio C, Quantock AJ, Burton MJ, Heard CM. In Vitro Topical Delivery of Chlorhexidine to the Cornea: Enhancement Using Drug-Loaded Contact Lenses and β-Cyclodextrin Complexation, and the Importance of Simulating Tear Irrigation. Mol Pharm 2020;17:1428-1441. [PMID: 32125863 DOI: 10.1021/acs.molpharmaceut.0c00140] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]

Abstract

Microbial keratitis is a severe, sight-threatening condition caused by various pathogens. Eyedrops are the standard delivery modality for treating these disorders; however, blinking reflex, elevated tear production, and nasolacrimal drainage eliminate much of the instilled dose within a few seconds. Therefore, eyedrops must be applied repeatedly for prolonged periods. The present study aimed to probe more effective ocular delivery of chlorhexidine based upon drug-loaded hydrogel contact lenses and β-cyclodextrin (β-CD), while also determining the effect of constant irrigation with simulated tear fluid (STF) in in vitro experiments. Chlorhexidine digluconate (as 0.2 and 2% solutions, β-CD inclusion complexes, and loaded hydrogel contact lenses) were applied to enucleated porcine eyes as single or multiple 10 μL doses, or as drug-loaded contact lenses, with and without β-CD. The corneas were then excised and drug-extracted quantified by high-performance liquid chromatography (HPLC). The effect of constant irrigation by STF was evaluated to test the effect of increased tear production on corneal delivery. Potential antimicrobial activity of the delivered drug was also assessed. Results showed that drug-loaded contact lenses delivered the greatest amount of chlorhexidine into the cornea over a 24 h period, while the eyedrop solution comparator delivered the least. The β-CD significantly enhanced chlorhexidine delivery to the cornea from eyedrop solution, although contact lenses loaded with chlorhexidine-β-CD failed to enhance delivery. β-CD within the hydrogel matrix impeded drug release. Constant irrigation with STF significantly reduced the amount of drug delivered to the cornea in all cases. Chlorhexidine retained antimicrobial activity in all delivery methods. Hydrogel contact lenses loaded with chlorhexidine delivered significantly higher levels to the cornea compared to eyedrops, either multiple hourly doses or a single dose. They also offer reduced application, in particular, to a nonulcerated corneal infection. Finally, the importance of fully accounting for tear production in in vitro ocular delivery experiments was highlighted.

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Affiliation(s)

Melissa G Hewitt School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Wales, Cardiff CF10 3NB, U.K
Peter W J Morrison School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Wales, Cardiff CF10 3NB, U.K.,School of Optometry and Vision Sciences, Cardiff University, Wales, Cardiff CF24 4HQ, U.K
Hannah M Boostrom School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Wales, Cardiff CF10 3NB, U.K
Siân R Morgan School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Wales, Cardiff CF10 3NB, U.K.,School of Optometry and Vision Sciences, Cardiff University, Wales, Cardiff CF24 4HQ, U.K
Melissa Fallon School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Wales, Cardiff CF10 3NB, U.K.,School of Optometry and Vision Sciences, Cardiff University, Wales, Cardiff CF24 4HQ, U.K
Philip N Lewis School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Wales, Cardiff CF10 3NB, U.K.,School of Optometry and Vision Sciences, Cardiff University, Wales, Cardiff CF24 4HQ, U.K
David Whitaker School of Optometry and Vision Sciences, Cardiff University, Wales, Cardiff CF24 4HQ, U.K.,School of Healthcare Sciences, Cardiff University, Wales, Cardiff CF24 4HQ, U.K
Andrea Brancale School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Wales, Cardiff CF10 3NB, U.K
Carmine Varricchio School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Wales, Cardiff CF10 3NB, U.K
Andrew J Quantock School of Optometry and Vision Sciences, Cardiff University, Wales, Cardiff CF24 4HQ, U.K
Matthew J Burton International Centre for Eye Health, Faculty of Infectious & Tropical Diseases, London School of Hygiene and Tropical Medicine, London WC1E 7HT, U.K.,Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, U.K
Charles M Heard School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Wales, Cardiff CF10 3NB, U.K

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Peixoto D, Prestes DP. Parasitic Infections of the Stem Cell Transplant Recipient and the Hematologic Malignancy Patient, Including Toxoplasmosis and Strongyloidiasis. Infect Dis Clin North Am 2019;33:567-591. [PMID: 31005139 DOI: 10.1016/j.idc.2019.02.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]

Li W, Wang Z, Qu J, Zhang Y, Sun X. Acanthamoeba keratitis related to contact lens use in a tertiary hospital in China. BMC Ophthalmol 2019;19:202. [PMID: 31533675 PMCID: PMC6751601 DOI: 10.1186/s12886-019-1210-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Accepted: 08/30/2019] [Indexed: 12/17/2022] Open

Abstract

Background

To report the clinical and microbiological features of Acanthamoeba keratitis (AK) related to contact lens use in a tertiary hospital in China.

Methods

In this retrospective study, the medical results of 61 cases of AK related to contact lens use from January 2000 to December 2017 were reviewed. The data included patients’ demographics, lens type, history, risk factors, disease stages, corneal scraping and culture reports, and treatments. Moreover, genotypic identification of some of the isolates was carried out with a PCR assay and sequence analysis of the 18S ribosomal DNA gene.

Results

There were 64 eyes included in the study. A total of 32.8% of the patients wore soft contact lenses, and 67.2% of patients used overnight orthokeratology. In the cases (20 eyes) in the early stage, 65% (13 eyes) had positive results according to Giemsa-stained smears, and 0.9% sodium chloride (NaCl) wet mounts revealed trophozoites in 7 eyes (35%). Six eyes (30%) were diagnosed by confocal microscopy combined with clinical signs. In the orthokeratology patients, 87.8% (36/41) rinsed their lenses and/or cases with tap water; 55% of soft-lens wearers wore their lenses while showering. The genotype of 9 isolates was determined, and all the strains belonged to genotype T4. In the orthokeratology group, the number of patients who required therapeutic penetrating keratoplasty after 2005 was less than that before 2005 (chi-square test, χ² = 4.209, P = 0.04).

Conclusions

More than two-thirds of the cases were associated with orthokeratology. Examinations with Giemsa-stained smears, 0.9% NaCl wet mounts and confocal microscopy should be performed for patients who are highly suspected of having early-stage AK to help with early diagnosis. In the orthokeratology group, the rate of therapeutic keratoplasty after 2005 was less than that before 2005.

Electronic supplementary material

The online version of this article (10.1186/s12886-019-1210-2) contains supplementary material, which is available to authorized users.

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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: 3.2] [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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Alves DDSMM, Gonçalves GS, Moraes AS, Alves LM, Carmo Neto JRD, Hecht MM, Nitz N, Gurgel-Gonçalves R, Bernardes G, Castro AMD, Chalita MR, Vinaud MC. The first Acanthamoeba keratitis case in the Midwest region of Brazil: diagnosis, genotyping of the parasite and disease outcome. Rev Soc Bras Med Trop 2018;51:716-719. [PMID: 30304286 DOI: 10.1590/0037-8682-0010-2018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 07/05/2018] [Indexed: 11/22/2022] Open

Affiliation(s)

Daniella de Sousa Mendes Moreira Alves Laboratório de Estudos da Relação Parasito-Hospedeiro, Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia, GO, Brasil
Gustavo Souza Gonçalves Departamento de Oftalmologia, Faculdade de Medicina, Universidade de Brasília, Brasília, DF, Brasil
Aline Silva Moraes Laboratório Interdisciplinar de Biociências, Faculdade de Medicina, Universidade de Brasília, Brasília, DF, Brasil
Luciano Moreira Alves Secretaria Estadual de Saúde do Estado de Goiás, Goiânia, GO, Brasil
José Rodrigues do Carmo Neto Laboratório de Estudos da Relação Parasito-Hospedeiro, Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia, GO, Brasil
Mariana Machado Hecht Laboratório Interdisciplinar de Biociências, Faculdade de Medicina, Universidade de Brasília, Brasília, DF, Brasil
Nadjar Nitz Laboratório Interdisciplinar de Biociências, Faculdade de Medicina, Universidade de Brasília, Brasília, DF, Brasil
Rodrigo Gurgel-Gonçalves Laboratório de Parasitologia Médica e Biologia de Vetores, Faculdade de Medicina, Universidade de Brasília, Brasília, DF, Brasil
Geisa Bernardes Laboratório de Estudos da Relação Parasito-Hospedeiro, Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia, GO, Brasil
Ana Maria de Castro Laboratório de Estudos da Relação Parasito-Hospedeiro, Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia, GO, Brasil
Maria Regina Chalita Departamento de Oftalmologia, Faculdade de Medicina, Universidade de Brasília, Brasília, DF, Brasil
Marina Clare Vinaud Laboratório de Estudos da Relação Parasito-Hospedeiro, Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia, GO, Brasil

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Acanthamoeba Keratitis: Are Recent Cases More Severe? Cornea 2018;37:1381-1387. [DOI: 10.1097/ico.0000000000001640] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]