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Fan W, Li P, Wei Q, Liu X, Cai Y, Li B, Lu Y. Metagenomic next-generation sequencing-assisted diagnosis of a rare case of primary cutaneous acanthamoebiasis in an HIV patient: a case report. Front Cell Infect Microbiol 2024; 14:1356095. [PMID: 38863830 PMCID: PMC11165212 DOI: 10.3389/fcimb.2024.1356095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 05/07/2024] [Indexed: 06/13/2024] Open
Abstract
Pathogenic and free-living Acanthamoeba are widely distributed in the environment and have been reported to cause keratitis and universally fatal encephalitis. Primary cutaneous acanthamoebiasis caused by Acanthamoeba is exceedingly rare and presents as isolated necrotic cutaneous lesions without involvement of the cornea or central nervous system. Cutaneous acanthamoebiasis often occurs in immunocompromised patients and is likely overlooked or even misdiagnosed only by cutaneous biopsy tissue histopathological analysis. Here, we report a HIV-infected 63-year-old female with oral leukoplakia for 4 months and scattered large skin ulcers all over the body for 2 months. The cause of the cutaneous lesions was unclear through cutaneous specimens histopathological analysis, and subsequently Acanthamoeba were detected by metagenomic next-generation sequencing (mNGS), which may be the cause of cutaneous lesions. Based on the mNGS results, a pathologist subsequently reviewed the previous pathological slides and found trophozoites of Acanthamoeba so that the cause was identified, and the skin ulcers improved significantly after treatment with multi-drug combination therapy. Acanthamoeba is also a host of pathogenic microorganisms. The presence of endosymbionts enhances the pathogenicity of Acanthamoeba, and no other pathogens were reported in this case. mNGS is helpful for rapidly diagnosing the etiology of rare skin diseases and can indicate the presence or absence of commensal microorganisms.
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Affiliation(s)
- Wei Fan
- Department of Pathology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Pin Li
- Research and Development Department, Sinopharm Medical Laboratory (Wuhan) Co., Ltd., Wuhan, China
| | - Qihao Wei
- Research and Development Department, Sinopharm Genomics Technology Co., Ltd., Wuhan, China
| | - Xinru Liu
- Research and Development Department, Sinopharm Medical Laboratory (Wuhan) Co., Ltd., Wuhan, China
| | - Yuxiang Cai
- Department of Pathology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Bin Li
- Research and Development Department, Sinopharm Genomics Technology Co., Ltd., Wuhan, China
| | - Yaping Lu
- Research and Development Department, Sinopharm Medical Laboratory (Wuhan) Co., Ltd., Wuhan, China
- Research and Development Department, Sinopharm Genomics Technology Co., Ltd., Wuhan, China
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Messina M, Tucci D, Mocini S, Marruso V, Crotti S, Said D, Dua HS, Cagini C. Increasing incidence of contact-lens-related Acanthamoeba keratitis in a tertiary ophthalmology department in an Italian population. Eur J Ophthalmol 2024:11206721241242165. [PMID: 38509758 DOI: 10.1177/11206721241242165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/22/2024]
Abstract
PURPOSE The purpose of this paper is to report the increasing incidence of contact-lens related Acanthamoeba keratitis (AK) in a tertiary ophthalmology department in Umbria, central Italy. METHODS Observational and retrospective case series were carried out. A total of nine eyes with a diagnosis of AK were examined. All patients underwent a full slit lamp examination, in vivo confocal microscopy (IVCM) and corneal scraping. The IVCM was repeated at one and two-week and at one, three and six-month intervals. Samples of domestic tap water were also examined for PCR analysis. Patients were treated with levofloxacin0,5%, Polyhexamethylene biguanide 0.02%, and Propamidine Isetionate0,1%. RESULTS All patients were contact lens wearers. The average patient age was 27.75 (range 18-45), with three men and five women. The main clinical features were ciliary congestion, diffuse epitheliopathy with punctuated keratitis, multiple, small sub-epithelial, greyish, corneal infiltrates with epithelial defect, pseudodendritic corneal lesions, perineural infiltrates, corneal stromal cellularity, and stromal infiltrates. IVCM was indicative of Acanthamoeba in seven out of the nine eyes. All the positive IVCM images were section images showing double walled, bright-spot cysts with a clear chain-like arrangement of five or more cysts identified in three of the patients. PCR analysis of the water was negative in all cases. CONCLUSION Although PCR is the most common method used, the increased incidence of AK could mainly be related to a proper IVCM interpretation. A broad-spectrum antibiotic, such as levofloxacin might play a role in the early treatment of AK reducing the virulence of the amoeba.
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Affiliation(s)
- Marco Messina
- Department of Medicine and Surgery, Section of Ophthalmology, University of Perugia, S. Maria Della Misericordia Hospital, Perugia, Italy
| | - Davide Tucci
- Department of Medicine and Surgery, Section of Ophthalmology, University of Perugia, S. Maria Della Misericordia Hospital, Perugia, Italy
| | - Stefano Mocini
- Department of Medicine and Surgery, Section of Ophthalmology, University of Perugia, S. Maria Della Misericordia Hospital, Perugia, Italy
| | - Virginia Marruso
- Department of Medicine and Surgery, Section of Ophthalmology, University of Perugia, S. Maria Della Misericordia Hospital, Perugia, Italy
| | - Silvia Crotti
- Diagnostic Laboratory, Sperimental Zooprophylactic Institute of Umbria and Marche "Togo Rosati", Perugia, Italy
| | - Dalia Said
- Department of Ophthalmology, Section of Academic Ophthalmology, Division of Clinical Neuroscience, University of Nottingham, Nottingham, UK
| | - Harminder Singh Dua
- Department of Ophthalmology, Section of Academic Ophthalmology, Division of Clinical Neuroscience, University of Nottingham, Nottingham, UK
| | - Carlo Cagini
- Department of Medicine and Surgery, Section of Ophthalmology, University of Perugia, S. Maria Della Misericordia Hospital, Perugia, Italy
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Rayamajhee B, Willcox M, Sharma S, Mooney R, Petsoglou C, Badenoch PR, Sherchan S, Henriquez FL, Carnt N. Zooming in on the intracellular microbiome composition of bacterivorous Acanthamoeba isolates. ISME COMMUNICATIONS 2024; 4:ycae016. [PMID: 38500701 PMCID: PMC10945361 DOI: 10.1093/ismeco/ycae016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 11/29/2023] [Accepted: 01/22/2024] [Indexed: 03/20/2024]
Abstract
Acanthamoeba, a free-living amoeba in water and soil, is an emerging pathogen causing severe eye infection known as Acanthamoeba keratitis. In its natural environment, Acanthamoeba performs a dual function as an environmental heterotrophic predator and host for a range of microorganisms that resist digestion. Our objective was to characterize the intracellular microorganisms of phylogenetically distinct Acanthamoeba spp. isolated in Australia and India through directly sequencing 16S rRNA amplicons from the amoebae. The presence of intracellular bacteria was further confirmed by in situ hybridization and electron microscopy. Among the 51 isolates assessed, 41% harboured intracellular bacteria which were clustered into four major phyla: Pseudomonadota (previously known as Proteobacteria), Bacteroidota (previously known as Bacteroidetes), Actinomycetota (previously known as Actinobacteria), and Bacillota (previously known as Firmicutes). The linear discriminate analysis effect size analysis identified distinct microbial abundance patterns among the sample types; Pseudomonas species was abundant in Australian corneal isolates (P < 0.007), Enterobacteriales showed higher abundance in Indian corneal isolates (P < 0.017), and Bacteroidota was abundant in Australian water isolates (P < 0.019). The bacterial beta diversity of Acanthamoeba isolates from keratitis patients in India and Australia significantly differed (P < 0.05), while alpha diversity did not vary based on the country of origin or source of isolation (P > 0.05). More diverse intracellular bacteria were identified in water isolates as compared with clinical isolates. Confocal and electron microscopy confirmed the bacterial cells undergoing binary fission within the amoebal host, indicating the presence of viable bacteria. This study sheds light on the possibility of a sympatric lifestyle within Acanthamoeba, thereby emphasizing its crucial role as a bunker and carrier of potential human pathogens.
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Affiliation(s)
- Binod Rayamajhee
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, NSW 2052, Australia
| | - Mark Willcox
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, NSW 2052, Australia
| | - Savitri Sharma
- Jhaveri Microbiology Centre, Prof Brien Holden Eye Research Centre, Hyderabad Eye Research Foundation, L. V. Prasad Eye Institute (LVPEI), Hyderabad, 500034, India
| | - Ronnie Mooney
- School of Health and Life Sciences, University of the West of Scotland, Blantyre, PA1 2BE, United Kingdom
| | - Constantinos Petsoglou
- Sydney and Sydney Eye Hospital, South-Eastern Sydney Local Health District, Sydney, NSW 2000, Australia
- Save Sight Institute, University of Sydney, Sydney, NSW 2000, Australia
| | - Paul R Badenoch
- College of Medicine and Public Health, Flinders University, Adelaide, 5042, Australia
| | - Samendra Sherchan
- School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA 70112, United States
| | - Fiona L Henriquez
- School of Health and Life Sciences, University of the West of Scotland, Blantyre, PA1 2BE, United Kingdom
| | - Nicole Carnt
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, NSW 2052, Australia
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Rayamajhee B, Willcox M, Henriquez FL, Vijay AK, Petsoglou C, Shrestha GS, Peguda HK, Carnt N. The role of naturally acquired intracellular Pseudomonas aeruginosa in the development of Acanthamoeba keratitis in an animal model. PLoS Negl Trop Dis 2024; 18:e0011878. [PMID: 38166139 PMCID: PMC10795995 DOI: 10.1371/journal.pntd.0011878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 01/18/2024] [Accepted: 12/21/2023] [Indexed: 01/04/2024] Open
Abstract
BACKGROUND Acanthamoeba is an environmental host for various microorganisms. Acanthamoeba is also becoming an increasingly important pathogen as a cause of keratitis. In Acanthamoeba keratitis (AK), coinfections involving pathogenic bacteria have been reported, potentially attributed to the carriage of microbes by Acanthamoeba. This study assessed the presence of intracellular bacteria in Acanthamoeba species recovered from domestic tap water and corneas of two different AK patients and examined the impact of naturally occurring intracellular bacteria within Acanthamoeba on the severity of corneal infections in rats. METHODOLOGY/PRINCIPAL FINDINGS Household water and corneal swabs were collected from AK patients. Acanthamoeba strains and genotypes were confirmed by sequencing. Acanthamoeba isolates were assessed for the presence of intracellular bacteria using sequencing, fluorescence in situ hybridization (FISH), and electron microscopy. The viability of the bacteria in Acanthamoeba was assessed by labelling with alkyne-functionalized D-alanine (alkDala). Primary human macrophages were used to compare the intracellular survival and replication of the endosymbiotic Pseudomonas aeruginosa and a wild type strain. Eyes of rats were challenged intrastromally with Acanthamoeba containing or devoid of P. aeruginosa and evaluated for the clinical response. Domestic water and corneal swabs were positive for Acanthamoeba. Both strains belonged to genotype T4F. One of the Acanthamoeba isolates harboured P. aeruginosa which was seen throughout the Acanthamoeba's cytoplasm. It was metabolically active and could be seen undergoing binary fission. This motile strain was able to replicate in macrophage to a greater degree than strain PAO1 (p<0.05). Inoculation of Acanthamoeba containing the intracellular P. aeruginosa in rats eyes resulted in a severe keratitis with increased neutrophil response. Acanthamoeba alone induced milder keratitis. CONCLUSIONS/SIGNIFICANCE Our findings indicate the presence of live intracellular bacteria in Acanthamoeba can increase the severity of acute keratitis in vivo. As P. aeruginosa is a common cause of keratitis, this may indicate the potential for these intracellular bacteria in Acanthamoeba to lead to severe polymicrobial keratitis.
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Affiliation(s)
- Binod Rayamajhee
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
| | - Mark Willcox
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
| | - Fiona L. Henriquez
- School of Health and Life Sciences, University of the West of Scotland, Blantyre, Scotland, United Kingdom
| | - Ajay Kumar Vijay
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
| | - Constantinos Petsoglou
- Sydney and Sydney Eye Hospital, Southeastern Sydney Local Health District, Sydney, Australia
- Save Sight Institute, University of Sydney, Sydney, Australia
| | - Gauri Shankar Shrestha
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
| | - Hari Kumar Peguda
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
| | - Nicole Carnt
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
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Ahmed U, Sivasothy Y, Khan KM, Khan NA, Wahab SMA, Awang K, Othman MA, Anwar A. Malabaricones from the fruit of Myristica cinnamomea King as potential agents against Acanthamoeba castellanii. Acta Trop 2023; 248:107033. [PMID: 37783284 DOI: 10.1016/j.actatropica.2023.107033] [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: 07/20/2023] [Revised: 09/13/2023] [Accepted: 09/29/2023] [Indexed: 10/04/2023]
Abstract
Acanthamoeba castellanii is an opportunistic free-living amoeba (FLA) pathogen which can cause fatal central nervous system (CNS) infection, granulomatous amoebic encephalitis (GAE) and potentially blinding ocular infection, Acanthamoeba keratitis (AK). Acanthamoeba species remain a challenging protist to treat due to the unavailability of safe and effective therapeutic drugs and their ability to protect themselves in the cyst stage. Natural products and their secondary metabolites play a pivotal role in drug discovery against various pathogenic microorganisms. In the present study, the ethyl acetate extract of Myristica cinnamomea King fruit was evaluated against A. castellanii (ATCC 50492), showing an IC50 of 45.102 ± 4.62 µg/mL. Previously, the bio-guided fractionation of the extract resulted in the identification of three active compounds, namely Malabaricones (A-C). The isolated and thoroughly characterized acylphenols were evaluated for their anti-amoebic activity against A. castellanii for the first time. Among tested compounds, Malabaricone B (IC50 of 101.31 ± 17.41 µM) and Malabaricone C (IC50 of 49.95 ± 6.33 µM) showed potent anti-amoebic activity against A. castellanii trophozoites and reduced their viability up-to 75 and 80 %, respectively. Moreover, both extract and Malabaricones also significantly (p < 0.05) inhibit the encystation and excystation of A. castellanii, while showed minimal toxicity against human keratinocyte cells (HaCaT cells) at lower tested concentrations. Following that, the explanation of the possible mechanism of action of purified compounds were assessed by detection of the state of chromatin. Hoechst/PI 33342 double staining showed that necrotic cell death occurred in A. castellanii trophozoites after 8 h treatment of Malabaricones (A-C). These findings demonstrate that Malabaricones B and C could serve as promising therapeutic options against A. castellanii infections.
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Affiliation(s)
- Usman Ahmed
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, Subang Jaya, 47500, Selangor, Malaysia
| | - Yasodha Sivasothy
- School of Pharmacy, Monash University Malaysia, Bandar Sunway, 47500, Selangor, Malaysia
| | - Khalid Mohammed Khan
- H. E. J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, 75270, Pakistan
| | - Naveed Ahmed Khan
- Microbiota Research Center, Istinye University, Istanbul, 34010, Turkey
| | - Siti Mariam Abdul Wahab
- Faculty of Pharmacy and Health Sciences, Royal College of Medicine Perak, Universiti Kuala Lumpur, Ipoh, 30450, Malaysia
| | - Khalijah Awang
- Department of Chemistry, Faculty of Science, Universiti Malaya, 50603, Kuala Lumpur, Malaysia; Centre for Natural Products and Drug Discovery (CENAR), Universiti Malaya, 50603, Kuala Lumpur, Malaysia
| | - Muhamad Aqmal Othman
- Department of Chemistry, Faculty of Science, Universiti Malaya, 50603, Kuala Lumpur, Malaysia; Centre for Natural Products and Drug Discovery (CENAR), Universiti Malaya, 50603, Kuala Lumpur, Malaysia.
| | - Ayaz Anwar
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, Subang Jaya, 47500, Selangor, Malaysia.
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Rayamajhee B, Williams NLR, Siboni N, Rodgers K, Willcox M, Henriquez FL, Seymour JR, Potts J, Johnson C, Scanes P, Carnt N. Identification and quantification of Acanthamoeba spp. within seawater at four coastal lagoons on the east coast of Australia. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 901:165862. [PMID: 37541500 DOI: 10.1016/j.scitotenv.2023.165862] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 07/08/2023] [Accepted: 07/26/2023] [Indexed: 08/06/2023]
Abstract
Acanthamoeba is an opportunistic free-living heterotrophic protist that is the most predominant amoeba in diverse ecological habitats. Acanthamoeba causes amoebic keratitis (AK), a painful and potentially blinding corneal infection. Major risk factors for AK have been linked to non-optimal contact lens hygiene practices and Acanthamoeba contamination of domestic and recreational water. This study investigated the incidence and seasonal variation of Acanthamoeba spp. within coastal lagoons located on the eastern coast of Australia and then examined the association between Acanthamoeba and water abiotic factors and bacterial species within the water. Water samples were collected from four intermittently closed and open lagoons (ICOLLs) (Wamberal, Terrigal, Avoca and Cockrone) every month between August 2019 to July 2020 except March and April. qPCR was used to target the Acanthamoeba 18S rRNA gene, validated by Sanger sequencing. Water abiotic factors were measured in situ using a multiprobe metre and 16S rRNA sequencing (V3-V4) was performed to characterise bacterial community composition. Network analysis was used to gauge putative associations between Acanthamoeba incidence and bacterial amplicon sequence variants (ASVs). Among 206 water samples analysed, 79 (38.3%) were Acanthamoeba positive and Acanthamoeba level was significantly higher in summer compared with winter, spring, or autumn (p = 0.008). More than 50% (23/45) water samples of Terrigal were positive for Acanthamoeba which is a highly urbanised area with extensive recreational activities while about 32% (16/49) samples were positive from Cockrone that is the least impacted lagoon by urban development. All sequenced strains belonged to the pathogenic genotype T4 clade except two which were of genotype clades T2 and T5. Water turbidity, temperature, intl1 gene concentration, and dissolved O2 were significantly associated with Acanthamoeba incidence (p < 0.05). The ASVs level of cyanobacteria, Pseudomonas spp., Candidatus spp., and marine bacteria of the Actinobacteria phylum and Acanthamoeba 18S rRNA genes were positively correlated (Pearson's r ≥ 0.14). The presence of Acanthamoeba spp. in all lagoons, except Wamberal, was associated with significant differences in the composition of bacterial communities (beta diversity). The results of this study suggest that coastal lagoons, particularly those in urbanised regions with extensive water recreational activities, may pose an elevated risk to human health due to the relatively high incidence of pathogenic Acanthamoeba in the summer. These findings underscore the importance of educating the public about the rare yet devastating impact of AK on vision and quality of life, highlighting the need for collaborative efforts between public health officials and educators to promote awareness and preventive measures, especially focusing lagoons residents and travellers.
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Affiliation(s)
- Binod Rayamajhee
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia.
| | - Nathan L R Williams
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Sydney, Australia
| | - Nachshon Siboni
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Sydney, Australia
| | - Kiri Rodgers
- Institute of Biomedical and Environmental Health Research, School of Health and Life Sciences, University of the West of Scotland, Blantyre, South Lanarkshire, G72 0LH, Scotland, UK
| | - Mark Willcox
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
| | - Fiona L Henriquez
- Institute of Biomedical and Environmental Health Research, School of Health and Life Sciences, University of the West of Scotland, Blantyre, South Lanarkshire, G72 0LH, Scotland, UK
| | - Justin R Seymour
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Sydney, Australia
| | - Jaimie Potts
- Estuaries and Catchments Team, Waters Wetland Coastal Science Branch, NSW Department of Planning, Industry and Environment, Lidcombe, NSW 2141, Australia
| | - Colin Johnson
- Estuaries and Catchments Team, Waters Wetland Coastal Science Branch, NSW Department of Planning, Industry and Environment, Lidcombe, NSW 2141, Australia
| | - Peter Scanes
- Estuaries and Catchments Team, Waters Wetland Coastal Science Branch, NSW Department of Planning, Industry and Environment, Lidcombe, NSW 2141, Australia
| | - Nicole Carnt
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
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Matsuo T, Nose M. A simple method for culturing Acanthamoeba from soft contact lens at a clinical laboratory of a hospital: Case report of Acanthamoeba keratitis. Clin Case Rep 2023; 11:e8248. [PMID: 38028087 PMCID: PMC10661332 DOI: 10.1002/ccr3.8248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 10/24/2023] [Accepted: 10/27/2023] [Indexed: 12/01/2023] Open
Abstract
Key Clinical Message A simple culturing method for Acanthamoeba available at a clinical laboratory is a key for making timely diagnosis and starting treatment with topical 0.02% chlorhexidine gluconate eye drops, together with 0.1% miconazole or fluconazole eye drops. Abstract A 19-year-old woman with pain and injection in the right eye showed spotty corneal infiltration and radiating linear opacity. Suspicious of Acanthamoeba keratitis, corneal scraping, and the soft contact lens were sent to in-house clinical laboratory to culture successfully Acanthamoeba on Sabouraud dextrose agar plate painted with heat-treated dead bacilli.
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Affiliation(s)
- Toshihiko Matsuo
- Graduate School of Interdisciplinary Science and Engineering in Health SystemsOkayama UniversityOkayama CityJapan
- Department of OphthalmologyOkayama University HospitalOkayama CityJapan
| | - Motoko Nose
- Department of Clinical LaboratoryOkayama University HospitalOkayama CityJapan
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Ledbetter EC, Capistrano da Silva E, Dong L, McDonough SP. Experimental Induction of Acute Acanthamoeba castellanii Keratitis in Cats. Transl Vis Sci Technol 2023; 12:10. [PMID: 37566398 PMCID: PMC10424800 DOI: 10.1167/tvst.12.8.10] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 07/09/2023] [Indexed: 08/12/2023] Open
Abstract
Purpose To develop a feline model of acute Acanthamoeba keratitis using methods that replicate natural routes of infection transmission. Methods Corneal Acanthamoeba castellanii inoculation was performed by three methods: topical inoculation with Acanthamoeba solution following corneal abrasion, placement of a contaminated contact lens for 7 days, and placement of a contaminated contact lens for 7 days following corneal abrasion. Sham inoculations with parasite-free medium and sterile contact lenses were also performed. Cats were monitored by ocular examination and in vivo corneal confocal microscopy for 21 days post-inoculation. Corneal samples were collected at intervals for microbiologic assessment, histopathology, and immunohistochemistry. Results All cats in the corneal abrasion groups developed clinical keratitis. Clinical ocular disease was inconsistently detected in cats from the contaminated contact lens only group. Initial corneal lesions were characterized by multifocal epithelial leukocyte infiltrates. Ocular lesions progressed to corneal epithelial ulceration and diffuse stromal inflammation. After 14 days, corneal ulcerations resolved, and stromal inflammation consolidated into multifocal subepithelial and stromal infiltrates. Corneal amoebae were detected by culture, in vivo confocal microscopy, histopathology, and immunohistochemistry in cats with keratitis. Neutrophilic and lymphocytic keratoconjunctivitis with lymphoplasmacytic anterior uveitis were identified by histopathology. Coinfection with aerobic bacteria was detected in some, but not all, cats with keratitis. Ocular disease was not detected in the sham inoculation groups. Conclusions Feline Acanthamoeba keratitis is experimentally transmissible by contaminated contact lenses and topical inoculation following corneal epithelial trauma. Translational Relevance Experimentally induced acute Acanthamoeba keratitis in cats is clinically and histopathologically similar to its human counterpart.
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Affiliation(s)
- Eric C. Ledbetter
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | | | - Longying Dong
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Sean P. McDonough
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
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Büchele MLC, Nunes BF, Filippin-Monteiro FB, Caumo KS. Diagnosis and treatment of Acanthamoeba Keratitis: A scoping review demonstrating unfavorable outcomes. Cont Lens Anterior Eye 2023; 46:101844. [PMID: 37117130 DOI: 10.1016/j.clae.2023.101844] [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: 12/13/2022] [Revised: 04/09/2023] [Accepted: 04/12/2023] [Indexed: 04/30/2023]
Abstract
Acanthamoeba spp. are pathogens that cause Acanthamoeba keratitis (AK), a serious cornea inflammation that can lead to gradual loss of vision, permanent blindness, and keratoplasty. The efficacy of AK treatment depends on the drug's ability to reach the target tissue by escaping the protective eye barrier. No single drug can eradicate the living forms of the amoeba and be non-toxic to the cornea tissue. The treatment aims to eradicate both forms of protozoan life but is hampered by the resistance of the cysts to the most available drugs, leading to prolonged infection and relapses. Drug therapy is currently performed mainly using diamidines and biguanides, as they are more effective against cysts. However, they are cytotoxic to corneal cells. Drugs are applied topically, and hourly. Over time, the frequency of administration decreases, but the treatment time varies from month to years. This study aims to obtain an up-to-date summary of the literature since 2010, allowing us to identify the trends and gaps and address future research involving new alternatives for treating AK. The results were divided into three phases, pre-treatment, empirical treatment, and the treatment after diagnosis confirmation. The drugs prescribed were stratified into antiamoebic, antibiotic, antifungal, antivirals, and steroids. It was possible to observe the transition in drug prescription during three different stages until the diagnosis was confirmed. There were more indications for antibiotic, antifungal, and antiviral drugs in the early stages of the disease. The antiamoebic drugs were only prescribed after exhausting other treatments. This can be directly involved in developing complications and no responsiveness to medical treatment.
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Affiliation(s)
- Maria Luiza Carneiro Büchele
- Laboratório de Investigação Aplicada a Protozoários de Protozoários Emergentes (LADIPE), Florianópolis, SC 88040-970, Brazil
| | - Bruno Fonseca Nunes
- Department of Clinical Analyses, Centro de Ciências da Saúde, Universidade Federal de Santa Catarina, Florianópolis, SC 88040900, Brazil
| | - Fabíola Branco Filippin-Monteiro
- Department of Clinical Analyses, Centro de Ciências da Saúde, Universidade Federal de Santa Catarina, Florianópolis, SC 88040900, Brazil.
| | - Karin Silva Caumo
- Laboratório de Investigação Aplicada a Protozoários de Protozoários Emergentes (LADIPE), Florianópolis, SC 88040-970, Brazil; Department of Clinical Analyses, Centro de Ciências da Saúde, Universidade Federal de Santa Catarina, Florianópolis, SC 88040900, Brazil.
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Huang JM, Sung KC, Lin WC, Lai HY, Wang YJ. Enhancement of capsular hypermucoviscosity in Klebsiella pneumoniae by Acanthamoeba. PLoS Negl Trop Dis 2023; 17:e0011541. [PMID: 37566587 PMCID: PMC10495012 DOI: 10.1371/journal.pntd.0011541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 09/11/2023] [Accepted: 07/18/2023] [Indexed: 08/13/2023] Open
Abstract
BACKGROUND Acanthamoeba and Klebsiella pneumoniae are both environmental commensals. Recently, clinical harm caused by hypermucoviscous K. pneumoniae has been observed. However, the interaction between these microbes and the origin of hypermucoviscous K. pneumoniae have not been reported. METHODOLOGY/PRINCIPAL FINDINGS Here, we report that the bacterial capsule is enlarged when co-cultured with Acanthamoeba using India ink staining, and this effect depends on the number of parasites present. This interaction results in an enhancement of capsular polysaccharide production in the subsequent generations of K. pneumoniae, even without co-culturing with Acanthamoeba. The hypermucoviscosity of the capsule was examined using the sedimentation assay and string test. We also screened other K. pneumoniae serotypes, including K1, K2, K5, and K20, for interaction with Acanthamoeba using India ink staining, and found the same interaction effect. CONCLUSIONS/SIGNIFICANCE These findings suggest that the interaction between Acanthamoeba and K. pneumoniae could lead to harmful consequences in public health and nosocomial disease control, particularly hypermucoviscous K. pneumoniae infections.
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Affiliation(s)
- Jian-Ming Huang
- School of Medicine, National Tsing Hua University, Hsinchu, Taiwan
- Institute of Molecular and Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan
| | - Ko-Chiang Sung
- Department of Clinical Laboratory, Chest Hospital, Ministry of Health and Welfare, Tainan, Taiwan
| | - Wei-Chen Lin
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Department of Parasitology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Hong-Yue Lai
- Department of Pharmacology, School of Medicine, China Medical University, Taichung, Taiwan
| | - Yu-Jen Wang
- Department of Parasitology, School of Medicine, China Medical University, Taichung, Taiwan
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Novel Anti-Acanthamoebic Activities of Irosustat and STX140 and Their Nanoformulations. Antibiotics (Basel) 2023; 12:antibiotics12030561. [PMID: 36978428 PMCID: PMC10044433 DOI: 10.3390/antibiotics12030561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 03/02/2023] [Accepted: 03/07/2023] [Indexed: 03/14/2023] Open
Abstract
Pathogenic Acanthamoeba produce keratitis and fatal granulomatous amoebic encephalitis. Treatment remains problematic and often ineffective, suggesting the need for the discovery of novel compounds. For the first time, here we evaluated the effects of the anticancer drugs Irosustat and STX140 alone, as well as their nanoformulations, against A. castellanii via amoebicidal, excystment, cytopathogenicity, and cytotoxicity assays. Nanoformulations of the compounds were successfully synthesized with high encapsulation efficiency of 94% and 82% for Irosustat and STX140, respectively. Nanoparticles formed were spherical in shape and had a unimodal narrow particle size distribution, mean of 145 and 244 nm with a polydispersity index of 0.3, and surface charge of −14 and −15 mV, respectively. Irosustat and STX140 exhibited a biphasic release profile with almost 100% drug released after 48 h. Notably, Irosustat significantly inhibited A. castellanii viability and amoebae-mediated cytopathogenicity and inhibited the phenotypic transformation of amoebae cysts into the trophozoite form, however their nanoformulations depicted limited effects against amoebae but exhibited minimal cytotoxicity when tested against human cells using lactate dehydrogenase release assays. Accordingly, both compounds have potential for further studies, with the hope of discovering novel anti-Acanthamoeba compounds, and potentially developing targeted therapy against infections of the central nervous system.
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Antiamoebic Properties of Ceftriaxone and Zinc-Oxide-Cyclodextrin-Conjugated Ceftriaxone. Antibiotics (Basel) 2022; 11:antibiotics11121721. [PMID: 36551378 PMCID: PMC9774710 DOI: 10.3390/antibiotics11121721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 11/20/2022] [Accepted: 11/20/2022] [Indexed: 12/05/2022] Open
Abstract
Acanthamoeba castellanii is a ubiquitous free-living amoeba capable of instigating keratitis and granulomatous amoebic encephalitis in humans. Treatment remains limited and inconsistent. Accordingly, there is a pressing need for novel compounds. Nanotechnology has been gaining attention for enhancing drug delivery and reducing toxicity. Previous work has shown that various antibiotic classes displayed antiamoebic activity. Herein, we employed two antibiotics: ampicillin and ceftriaxone, conjugated with the nanocarrier zinc oxide and β-cyclodextrin, and tested them against A. castellanii via amoebicidal, amoebistatic, encystment, excystment, cytopathogenicity, and cytotoxicity assays at a concentration of 100 μg/mL. Notably, zinc oxide β-cyclodextrin ceftriaxone significantly inhibited A. castellanii growth and cytopathogenicity. Additionally, both zinc oxide β-cyclodextrin ceftriaxone and ceftriaxone markedly inhibited A. castellanii encystment. Furthermore, all the tested compounds displayed negligible cytotoxicity. However, minimal anti-excystment or amoebicidal effects were observed for the compounds. Accordingly, this novel nanoconjugation should be employed in further studies in hope of discovering novel anti-Acanthamoeba compounds.
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