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Bajka A, Said S, Quiblier C, Schulthess B, Reinhold I, Barthelmes D, Zweifel SA, Blaser F. Long-Term Prevalence of Fungal Keratitis at a Swiss Tertiary Eye Clinic. Microorganisms 2024; 12:1637. [PMID: 39203477 PMCID: PMC11356936 DOI: 10.3390/microorganisms12081637] [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: 07/22/2024] [Revised: 08/06/2024] [Accepted: 08/08/2024] [Indexed: 09/03/2024] Open
Abstract
Fungal keratitis is a rare yet severe infection of the cornea. Fungal species distribution depends on the climate and socioeconomic status and can show regional variation. This retrospective single-center study was conducted at a tertiary eye care center and the collaborating Institute of Medical Microbiology in Switzerland. On investigating all fungal-positive corneal scrapings and contact lens assessments of patients with keratitis from January 2012 to December 2023, 206 patients were identified, of which 113 (54.9%) were female. The median age was 38 (IQR 29.8, [18-93]), and 154 (74.8%) applied contact lenses. The most commonly found pathogen was Candida spp., followed by Fusarium spp. Molds were 1.8 times more common than yeasts. Linear regression showed no significant increase or decrease in the infection rate over time (p = 0.5). In addition, 10 patients (4.9%) were found to have coinfections with Acanthamoeba, 11 (5.3%) with HSV-1, none with HSV-2, and 4 (1.9%) with VZV. This study provides a long-term overview of fungal-positive corneal scrapings and contact lens specimens of patients with fungal keratitis. Based on our results, coinfections with Acanthamoeba, HSV, and VZV are frequent, especially in patients wearing contact lenses. Thus, wearing contact lenses may facilitate coinfection in fungal keratitis.
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Affiliation(s)
- Anahita Bajka
- Department of Ophthalmology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland; (A.B.)
| | - Sadiq Said
- Department of Ophthalmology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland; (A.B.)
| | - Chantal Quiblier
- Institute of Medical Microbiology, University of Zurich, 8006 Zurich, Switzerland
| | - Bettina Schulthess
- Institute of Medical Microbiology, University of Zurich, 8006 Zurich, Switzerland
| | - Ilana Reinhold
- Department of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, 8091 Zurich, Switzerland
| | - Daniel Barthelmes
- Department of Ophthalmology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland; (A.B.)
| | - Sandrine Anne Zweifel
- Department of Ophthalmology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland; (A.B.)
| | - Frank Blaser
- Department of Ophthalmology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland; (A.B.)
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Blaser F, Bajka A, Grimm F, Metzler S, Herrmann D, Barthelmes D, Zweifel SA, Said S. Assessing PCR-Positive Acanthamoeba Keratitis-A Retrospective Chart Review. Microorganisms 2024; 12:1214. [PMID: 38930596 PMCID: PMC11205950 DOI: 10.3390/microorganisms12061214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2024] [Revised: 06/04/2024] [Accepted: 06/13/2024] [Indexed: 06/28/2024] Open
Abstract
Ophthalmologists' diagnostic and treatment competence in Acanthamoeba keratitis varies widely. This investigator-initiated, retrospective, single-center chart review examined the electronic patient files regarding PCR-positive Acanthamoeba keratitis. We included corneal and contact lens assessments. We further reviewed the patient's medical history, corneal scraping results regarding viral or fungal co-infections, and the duration from symptom onset to final diagnosis. We identified 59 eyes of 52 patients from February 2010 to February 2023, with 31 of 52 (59.6%) being female patients. The median (IQR, range) patient age was 33 (25.3 to 45.5 [13 to 90]) years, and the mean (SD, range) time to diagnosis after symptom onset was 18 (10.5 to 35 [3 to 70]) days. Overall, 7 of 52 (7.7%) patients displayed a bilateral Acanthamoeba infection, and 48 (92.3%) used contact lenses at symptom onset. Regarding other microbiological co-infections, we found virologic PCR testing in 45 of 52 (86.5%) patients, with 3 (6.7%) positive corneal scrapings. Fungal cultures were performed in 49 of 52 (94.2%) patients, with 5 (10.2%) positive corneal scrapings. The medical treatment success rate was 45/46 (97.8%). This study raises awareness of patient education in contact lens handling and screens for further microbial co-infections in suspected Acanthamoeba cases.
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Affiliation(s)
- Frank Blaser
- Department of Ophthalmology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland (S.S.)
| | - Anahita Bajka
- Department of Ophthalmology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland (S.S.)
| | - Felix Grimm
- Institute of Parasitology, University of Zurich, 8057 Zurich, Switzerland
| | - Simone Metzler
- Department of Ophthalmology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland (S.S.)
| | - Didier Herrmann
- Institute of Optometry, University of Applied Science, 4600 Olten, Switzerland
| | - Daniel Barthelmes
- Department of Ophthalmology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland (S.S.)
| | - Sandrine Anne Zweifel
- Department of Ophthalmology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland (S.S.)
| | - Sadiq Said
- Department of Ophthalmology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland (S.S.)
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Raghavan A, Rammohan R. Acanthamoeba keratitis - A review. Indian J Ophthalmol 2024; 72:473-482. [PMID: 38454853 PMCID: PMC11149514 DOI: 10.4103/ijo.ijo_2627_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 12/23/2023] [Indexed: 03/09/2024] Open
Abstract
This is a comprehensive review after a thorough literature search in PubMed-indexed journals, incorporating current information on the pathophysiology, clinical features, diagnosis, medical and surgical therapy, as well as outcomes of Acanthamoeba keratitis (AK). AK is a significant cause of ocular morbidity, and early diagnosis with timely institution of appropriate therapy is the key to obtaining good outcomes. The varied presentations result in frequent misdiagnosis, and co-infections can increase the morbidity of the disease. The first line of therapy continues to be biguanides and diamidines, with surgery as a last resort.
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Affiliation(s)
- Anita Raghavan
- Cornea & Refractive Surgery, Department of Microbiology, Aravind Eye Hospital and Post-Graduate Institute of Ophthalmology, Coimbatore, Tamil Nadu, India
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Rammohan R, Baidwal S, Venkatapathy N, Lorenzo-Morales J, Raghavan A. A 5-Year Review of Coinfections in Acanthamoeba keratitis From South India. Eye Contact Lens 2023; 49:334-338. [PMID: 37232397 DOI: 10.1097/icl.0000000000001005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/24/2023] [Indexed: 05/27/2023]
Abstract
PURPOSE To ascertain the frequency of coinfections in Acanthamoeba keratitis, the nature of copathogens involved, and to analyze the implications in the context of current research on amoebic interactions. METHODS A retrospective case review from a Tertiary Care Eye Hospital in South India. Smear and culture data for coinfections in Acanthamoeba corneal ulcers were collected from records over a 5-year period. The significance and relevance of our findings in the light of current research on Acanthamoeba interactions were analyzed. RESULTS Eighty-five cases of culture-positive Acanthamoeba keratitis were identified over a 5-year period (43 of them being coinfections). Fusarium was most commonly identified species, followed by Aspergillus and the dematiaceous fungi. Pseudomonas spp was the commonest bacterial isolate. CONCLUSION Coinfections with Acanthamoeba are common at our centre, and account for 50% of Acanthamoeba keratitis. The diverse nature of the organisms involved in coinfections suggest that such amoebic interactions with other organisms are probably more widespread than recognized. To the best of our knowledge, this is the first documentation from a long-term study of pathogen diversity in Acanthamoeba coinfections. It is possible that Acanthamoeba itself may be virulence enhanced and secondary to the co-organism, breaching the ocular surface defenses in an already compromised cornea. However, observations from the existing literature on Acanthamoeba interactions with bacteria and certain fungi are based mainly on nonocular or nonclinical isolates. It would be illuminating if such studies are performed on Acanthamoeba and coinfectors from corneal ulcers-to ascertain whether interactions are endosymbiotic or virulence enhanced through amoebic passage.
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Affiliation(s)
- Ram Rammohan
- Aravind Eye Hospital and Post-Graduate Institute of Ophthalmology (R.R., N.V., A.R.), Coimbatore; Fortis Hospital (S.B.), Chandigarh Road, Ludhiana, India; Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias (IUETSPC) (J.L.-M.), Universidad de La Laguna (ULL), La Laguna, Tenerife, Spain; Departamento de Obstetricia y Ginecología, Pediatría, Medicina Preventiva y Salud Pública, Toxicología, Medicina Legal y Forense y Parasitología (J.L.-M.), Universidad de La Laguna, Tenerife, Spain; and Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC) (J.L.-M.), Instituto de Salud Carlos III, Madrid, Spain
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Rayamajhee B, Willcox MDP, Henriquez FL, Petsoglou C, Subedi D, Carnt N. Acanthamoeba, an environmental phagocyte enhancing survival and transmission of human pathogens. Trends Parasitol 2022; 38:975-990. [PMID: 36109313 DOI: 10.1016/j.pt.2022.08.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 08/10/2022] [Accepted: 08/11/2022] [Indexed: 01/13/2023]
Abstract
The opportunistic protist Acanthamoeba, which interacts with other microbes such as bacteria, fungi, and viruses, shows significant similarity in cellular and functional aspects to human macrophages. Intracellular survival of microbes in this microbivorous amoebal host may be a crucial step for initiation of infection in higher eukaryotic cells. Therefore, Acanthamoeba-microbe adaptations are considered an evolutionary model of macrophage-pathogen interactions. This paper reviews Acanthamoeba as an emerging human pathogen and different ecological interactions between Acanthamoeba and microbes that may serve as environmental training grounds and a genetic melting pot for the evolution, persistence, and transmission of potential human pathogens.
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Affiliation(s)
- Binod Rayamajhee
- School of Optometry and Vision Science, Faculty of Medicine and Health, University of New South Wales (UNSW), Sydney, Australia.
| | - Mark D P Willcox
- School of Optometry and Vision Science, Faculty of Medicine and Health, University of New South Wales (UNSW), Sydney, Australia.
| | - Fiona L Henriquez
- Institute of Biomedical and Environmental Health Research, School of Health and Life Sciences, University of the West of Scotland, Blantyre, South Lanarkshire, G72 0LH, UK
| | - Constantinos Petsoglou
- Sydney and Sydney Eye Hospital, Southeastern Sydney Local Health District, Sydney, Australia; Save Sight Institute, University of Sydney, Sydney, Australia
| | - Dinesh Subedi
- School of Biological Sciences, Monash University, Clayton, Australia
| | - Nicole Carnt
- School of Optometry and Vision Science, Faculty of Medicine and Health, University of New South Wales (UNSW), Sydney, Australia
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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: 3.5] [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
Abstract
Free-living amoeba (FLA) group includes the potentially pathogenic genera Acanthamoeba, Naegleria, Balamuthia, Sappinia, and Vermamoeba, causative agents of human infections (encephalitis, keratitis, and disseminated diseases). In Brazil, the first report on pathogenic FLA was published in the 70s and showed meningoencephalitis caused by Naegleria spp. FLA studies are emerging, but no literature review is available to investigate this trend in Brazil critically. Thus, the present work aims to integrate and discuss these data. Scopus, PubMed, and Web of Science were searched, retrieving studies from 1974 to 2020. The screening process resulted in 178 papers, which were clustered into core and auxiliary classes and sorted into five categories: wet-bench studies, dry-bench studies, clinical reports, environmental identifications, and literature reviews. The papers dating from the last ten years account for 75% (134/178) of the total publications, indicating the FLA topic has gained Brazilian interest. Moreover, 81% (144/178) address Acanthamoeba-related matter, revealing this genus as the most prevalent in all categories. Brazil’s Southeast, South, and Midwest geographic regions accounted for 96% (171/178) of the publications studied in the present work. To the best of our knowledge, this review is the pioneer in summarising the FLA research history in Brazil.
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Affiliation(s)
- Natália Karla Bellini
- Universidade Federal de Minas Gerais, Faculdade de Farmácia, Departamento de Análises Clínicas e Toxicológicas, Belo Horizonte, MG, Brasil
| | - Otavio Henrique Thiemann
- Universidade de São Paulo, Instituto de Física de São Carlos, São Carlos, SP, Brasil.,Universidade Federal de São Carlos, Departamento de Genética e Evolução, São Carlos, SP, Brasil
| | - María Reyes-Batlle
- Universidad de La Laguna, Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias, Departamento de Obstetricia, Ginecología, Pediatría, Medicina Preventiva y Salud Pública, Toxicología, Medicina Legal y Forense y Parasitología, Red de Investigación Cooperativa en Enfermedades Tropicales, Tenerife, Islas Canarias, Spain
| | - Jacob Lorenzo-Morales
- Universidad de La Laguna, Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias, Departamento de Obstetricia, Ginecología, Pediatría, Medicina Preventiva y Salud Pública, Toxicología, Medicina Legal y Forense y Parasitología, Red de Investigación Cooperativa en Enfermedades Tropicales, Tenerife, Islas Canarias, Spain.,Instituto de Salud Carlos III, Consorcio Centro de Investigación Biomédica en Red MP de Enfermedades Infecciosas, Madrid, Spain
| | - Adriana Oliveira Costa
- Universidade Federal de Minas Gerais, Faculdade de Farmácia, Departamento de Análises Clínicas e Toxicológicas, Belo Horizonte, MG, Brasil
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Scruggs BA, Quist TS, Zimmerman MB, Salinas JL, Greiner MA. Risk factors, management, and outcomes of Acanthamoeba keratitis: A retrospective analysis of 110 cases. Am J Ophthalmol Case Rep 2022; 25:101372. [PMID: 35198803 PMCID: PMC8842025 DOI: 10.1016/j.ajoc.2022.101372] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Revised: 01/25/2022] [Accepted: 01/25/2022] [Indexed: 11/27/2022] Open
Abstract
Purpose To evaluate the risk factors, medical and surgical management, and visual outcomes of patients affected by Acanthamoeba keratitis (AK) over a 16-year period. Observations Records were reviewed retrospectively for all AK patients treated at University of Iowa between 2002 and 2017. Main outcomes measured were risk factors, time to diagnosis, coinfection types, initial and final visual acuities, and treatment outcomes, with failure of medical therapy defined as need for therapeutic keratoplasty (TK). Effects of steroid use on these outcomes were determined. Among all AK cases occurring during the study period (N = 110), the median age of the AK cohort was 31 years (range 8–80 years), and 49.1% were men. Contact lens wear was the primary risk factor for AK (95/100, 86.4%), and the median time to diagnosis was 0.70 (0.23–1.23) months. Forty-four AK patients (40%) failed medical therapy. Vision outcomes were better for AK patients with successful medical therapy compared to those requiring TK (LogMAR 0.00 v. 0.30; p < 0.0001). Corticosteroid use was associated with increased time to diagnosis (1.00 v. 0.50 months; p = 0.002), decreased final vision (LogMAR 0.10 v. 0.00; p < 0.05) and increased need for TK (40/77 v. 4/33; p < 0.001). Conclusions and importance Acanthamoeba keratitis cases have increased over the past two decades at our institution. In this large retrospective study, AK was commonly misdiagnosed with delayed diagnosis and high rates of failed medical therapy. Corticosteroid use before AK diagnosis led to poorer outcomes. Our findings underscore the need for ophthalmologists to suspect Acanthamoeba in the setting of contact lens-associated keratitis before topical steroids are initiated.
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Diehl MLN, Paes J, Rott MB. Genotype distribution of Acanthamoeba in keratitis: a systematic review. Parasitol Res 2021; 120:3051-3063. [PMID: 34351492 PMCID: PMC8339388 DOI: 10.1007/s00436-021-07261-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 07/20/2021] [Indexed: 12/16/2022]
Abstract
Acanthamoeba spp. are among the most worldwide prevalent protozoa. It is the causative agent of a disease known as Acanthamoeba keratitis, a painful and severe sight-threatening corneal infection that can lead to blindness. In recent years, the prevalence of Acanthamoeba keratitis has rapidly increased, growing its importance to human health. This systematic review aims to assess the distribution of Acanthamoeba sp. genotypes causing keratitis around the world, considering the sample collected type and the used identification method. Most of the cases were found in Asia and Europe. Not surprisingly, the T4 genotype was the most prevalent worldwide, followed by T3, T15, T11, and T5. Furthermore, the T4 genotype contains a higher number of species. Given the differences in pathology, susceptibility to treatment, and clinical outcome between distinct genotypes, it is essential to genotype isolates from Acanthamoeba keratitis cases to help to establish a better correlation between in vitro and in vivo activities, resulting in better drug therapies and successful treatment in cases of this important ocular infection.
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Affiliation(s)
- Maria Luisa Nunes Diehl
- Departamento de Microbiologia, Imunologia E Parasitologia, Instituto de Ciências, Básicas da Saúde, Universidade Federal Do Rio Grande Do Sul (UFRGS), Rua Sarmento Leite, 500, Porto Alegre, RS, 90050-170, Brazil
| | - Júlia Paes
- Departamento de Microbiologia, Imunologia E Parasitologia, Instituto de Ciências, Básicas da Saúde, Universidade Federal Do Rio Grande Do Sul (UFRGS), Rua Sarmento Leite, 500, Porto Alegre, RS, 90050-170, Brazil
| | - Marilise Brittes Rott
- Departamento de Microbiologia, Imunologia E Parasitologia, Instituto de Ciências, Básicas da Saúde, Universidade Federal Do Rio Grande Do Sul (UFRGS), Rua Sarmento Leite, 500, Porto Alegre, RS, 90050-170, Brazil.
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Acanthamoeba Keratitis Versus Mixed Acanthamoeba and Bacterial Keratitis: Comparison of Clinical and Microbiological Profiles. Cornea 2021; 39:1112-1116. [PMID: 32452992 DOI: 10.1097/ico.0000000000002337] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To compare the clinical profiles and outcomes of patients with Acanthamoeba keratitis with or without mixed bacterial infection. METHODS A retrospective analysis of microbiologically confirmed AK cases presenting to a tertiary care center over a 9-year period was conducted. Fourteen eyes in the coinfected group (group 1) and 24 eyes in the AK group (group 2) were analyzed to study the differences in these 2 groups of patients. The cases were diagnosed using a conventional microscopic analysis with staining techniques confirmed by cultural methods and were treated, which tailored to the microbiology report. RESULTS There was no difference in the demographic profile and presenting features in the 2 groups. Duration of symptoms and history of ocular trauma, contact lens wear, and previous steroid usage were also similar for both the groups. Dense central corneal infiltrate was the common presentation for both groups (7/14 vs. 16/24 in group 1 vs. group 2). Epithelial defect without dense stromal infiltrate was significantly more common in group 1 (42.9% vs. 4.2%, P = 0.003) as a presenting clinical feature. Hypopyon was present in 8/14 of group 1 versus 9/24 of group 2 eyes (P = 0.25). No significant difference was found in the final visual acuity in pure and mixed AK cases, and the need for surgical intervention was comparable. The most common bacterial pathogen isolated in the mixed group was the Staphylococcus species. CONCLUSIONS Bacterial coinfection is common in patients with Acanthamoeba keratitis. Coinfection did not point toward a worse clinical disease at presentation or outcome.
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Rayamajhee B, Subedi D, Peguda HK, Willcox MD, Henriquez FL, Carnt N. A Systematic Review of Intracellular Microorganisms within Acanthamoeba to Understand Potential Impact for Infection. Pathogens 2021; 10:pathogens10020225. [PMID: 33670718 PMCID: PMC7922382 DOI: 10.3390/pathogens10020225] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 02/13/2021] [Accepted: 02/15/2021] [Indexed: 12/20/2022] Open
Abstract
Acanthamoeba, an opportunistic pathogen is known to cause an infection of the cornea, central nervous system, and skin. Acanthamoeba feeds different microorganisms, including potentially pathogenic prokaryotes; some of microbes have developed ways of surviving intracellularly and this may mean that Acanthamoeba acts as incubator of important pathogens. A systematic review of the literature was performed in order to capture a comprehensive picture of the variety of microbial species identified within Acanthamoeba following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Forty-three studies met the inclusion criteria, 26 studies (60.5%) examined environmental samples, eight (18.6%) studies examined clinical specimens, and another nine (20.9%) studies analysed both types of samples. Polymerase chain reaction (PCR) followed by gene sequencing was the most common technique used to identify the intracellular microorganisms. Important pathogenic bacteria, such as E. coli, Mycobacterium spp. and P. aeruginosa, were observed in clinical isolates of Acanthamoeba, whereas Legionella, adenovirus, mimivirus, and unidentified bacteria (Candidatus) were often identified in environmental Acanthamoeba. Increasing resistance of Acanthamoeba associated intracellular pathogens to antimicrobials is an increased risk to public health. Molecular-based future studies are needed in order to assess the microbiome residing in Acanthamoeba, as a research on the hypotheses that intracellular microbes can affect the pathogenicity of Acanthamoeba infections.
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Affiliation(s)
- Binod Rayamajhee
- School of Optometry and Vision Science, University of New South Wales (UNSW), Sydney, NSW 2052, Australia; (H.K.P.); (M.D.W.); (N.C.)
- Department of Infection and Immunology, Kathmandu Research Institute for Biological Sciences (KRIBS), Lalitpur 44700, Nepal
- Correspondence: or
| | - Dinesh Subedi
- School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia;
| | - Hari Kumar Peguda
- School of Optometry and Vision Science, University of New South Wales (UNSW), Sydney, NSW 2052, Australia; (H.K.P.); (M.D.W.); (N.C.)
| | - Mark Duncan Willcox
- School of Optometry and Vision Science, University of New South Wales (UNSW), Sydney, NSW 2052, Australia; (H.K.P.); (M.D.W.); (N.C.)
| | - 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, UK;
| | - Nicole Carnt
- School of Optometry and Vision Science, University of New South Wales (UNSW), Sydney, NSW 2052, Australia; (H.K.P.); (M.D.W.); (N.C.)
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“Feast-Fit-Fist-Feat”: Overview of Free-living Amoeba Interactions with Fungi and Virulence as a Foundation for Success in Battle. CURRENT TROPICAL MEDICINE REPORTS 2021. [DOI: 10.1007/s40475-020-00220-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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de Faria LV, do Carmo PHF, da Costa MC, Peres NTA, Rodrigues Chagas IA, Furst C, Ferreira GF, Costa AO, Santos DA. Acanthamoeba castellanii as an alternative interaction model for the dermatophyte Trichophyton rubrum. Mycoses 2020; 63:1331-1340. [PMID: 32869415 DOI: 10.1111/myc.13173] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 08/13/2020] [Accepted: 08/19/2020] [Indexed: 12/13/2022]
Abstract
BACKGROUND Trichophyton rubrum (Tr) is the main aetiological agent of human dermatophytosis, being isolated from the environment and keratinised tissues. In the environment, Tr can interact with other organisms, such as free-living amoebas (FLA), which can act as an alternative host system to study the interaction between microbes and phagocytic cells. OBJECTIVES To characterise the Acanthamoeba castellanii (ALX)-Tr interaction. METHODS Interaction was characterised in three conditions: trophozoites (PYG), late (PYG/NES) and early (NES) encystation stimulus, evaluating encystation kinetics, phagocytosis, exocytosis and fungicidal activity dynamics. RESULTS Tr was able to induce ALX encystation and be internalised by ALX. The number of internalised conidia was high at 1 hour, and ALX presented fungicidal activity with increased intracellular ROS production and exocytosis. In PYG/NES, phagocytosis and ROS production were reduced, with decreased ALX's fungicidal activity. However, in NES there was an increased fungal engulfment, and a reduced ROS production and higher fungal burden. Furthermore, exogenous mannose decreased phagocytosis of Tr conidia, and divalent cations induced ROS production and increased ALX's fungicidal activity. Interestingly, phagocytosis was reduced in the presence of cytoskeleton inhibitor, but exocytosis was increased, suggesting that Tr conidia may have alternative pathways to escape ALX's cells. CONCLUSION A castellanii is a proper model for studying Tr-FLA interaction, since ALX can engulf, produce ROS and kill Tr, and all these parameters are influenced by an encystation stimulus and divalent cations. Moreover, this interaction is likely to occur in the environment implicating in the adaptation to environmental stressful conditions in both organisms.
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Affiliation(s)
- Lucas V de Faria
- Laboratório de Micologia, Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Paulo H F do Carmo
- Laboratório de Micologia, Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Marliete C da Costa
- Laboratório de Micologia, Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Nalu T A Peres
- Laboratório de Micologia, Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Isabela A Rodrigues Chagas
- Departamento de Análises Clínicas e Toxicológicas, Faculdade de Farmácia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Cinthia Furst
- Departamento de Patologia, Centro Ciências da Saúde, Universidade Federal do Espírito Santo, Vitoria, Brazil
| | - Gabriella F Ferreira
- Programa Multicêntrico de Pós Graduação em Bioquímica e Biologia Molecular, Universidade Federal de Juiz de Fora, Governador Valadares, Brazil
| | - Adriana O Costa
- Departamento de Análises Clínicas e Toxicológicas, Faculdade de Farmácia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Daniel A Santos
- Laboratório de Micologia, Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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Lemos Tavares P, Carvalho Ribeiro A, Kercher Berte F, da Silva Hellwig AH, Machado Pagani D, Tavares de Souza CC, Brittes Rott M, Scroferneker ML. The interaction between Sporothrix schenckii sensu stricto and Sporothrix brasiliensis with Acanthamoeba castellanii. Mycoses 2019; 63:302-307. [PMID: 31820499 DOI: 10.1111/myc.13043] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 12/04/2019] [Accepted: 12/05/2019] [Indexed: 12/01/2022]
Abstract
BACKGROUND Sporotrichosis is a group of zoonotic subcutaneous mycoses, found worldwide and caused by fungi belonging to the genus Sporothrix. Protozoans of the genus Acanthamoeba are widely distributed, and some species may be pathogenic and/or opportunistic. These organisms coexist in the same environment and may interact. OBJECTIVES This study determined the profile of interactions of S schenckii sensu stricto and S brasiliensis with A castellanii, using an in vitro co-culture model to evaluate the intrinsic characteristics of the two Sporothrix species and A castellanii. METHODS We compared the rate of phagocytosis of S schenckii sensu stricto and S brasiliensis by A castellanii; the viability of S schenckii sensu stricto and S brasiliensis after contact with A castellanii; the viability of the amoeba after contact with a fungal species; and the influence of S schenckii sensu stricto and S brasiliensis on the encystment process of A castellanii. RESULTS The analyses indicated that A castellanii phagocytised both S schenckii and S brasiliensis, with significantly more S schenckii than S brasiliensis in the first two hours of contact. Our results showed a significant increase in conidia and hyphae count after 72 hours of co-culture of A castellanii with S brasiliensis, and the amoebae lysed after they ingested the fungi, indicating that the fungi probably used the amoebae as a source of nutrition. CONCLUSIONS Our results were obtained in vitro and these organisms may not behave similarly in vivo; in vivo studies of co-infections are necessary in order to gain a thorough understanding of this relationship.
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Affiliation(s)
- Priscila Lemos Tavares
- Postgraduate Program in Medicine, Medical Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brasil
| | - Amanda Carvalho Ribeiro
- Department of Microbiology, Immunology and Parasitology, ICBS, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brasil
| | - Francisco Kercher Berte
- Department of Microbiology, Immunology and Parasitology, ICBS, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brasil
| | | | - Danielle Machado Pagani
- Postgraduate Program in Agricultural and Environmental Microbiology, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brasil
| | - Carine Cristina Tavares de Souza
- Postgraduate Program in Agricultural and Environmental Microbiology, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brasil
| | - Marilise Brittes Rott
- Department of Microbiology, Immunology and Parasitology, ICBS, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brasil.,Postgraduate Program in Agricultural and Environmental Microbiology, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brasil
| | - Maria Lúcia Scroferneker
- Postgraduate Program in Medicine, Medical Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brasil.,Department of Microbiology, Immunology and Parasitology, ICBS, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brasil
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Raghavan A, Baidwal S, Venkatapathy N, Rammohan R. The Acanthamoeba-Fungal Keratitis Study. Am J Ophthalmol 2019; 201:31-36. [PMID: 30721687 DOI: 10.1016/j.ajo.2019.01.024] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Revised: 01/22/2019] [Accepted: 01/24/2019] [Indexed: 10/27/2022]
Abstract
PURPOSE To ascertain the incidence of Acanthamoeba keratitis and the coexistence of Acanthamoeba and fungi in microbial keratitis. DESIGN Prospective cross-sectional study. METHODS Patients presenting with stromal keratitis were additionally tested for Acanthamoeba irrespective of the clinical diagnosis. Culture positivity was the gold standard. RESULTS Of the 401 cases included in the study, 40 were positive for Acanthamoeba (10%); of these 40, 16 were positive for both Acanthamoeba and fungi (4.5% of the study group was Acanthamoeba and fungal keratitis positive); 5 were positive for Acanthamoeba and bacteria; and 2 had triple infection with Acanthamoeba, fungi, and bacteria. Ring infiltrates and stromal edema are frequently associated with Acanthamoeba keratitis, as well as in Acanthamoeba coinfections. Ring infiltrates in particular were more frequently seen in the Acanthamoeba and fungal keratitis group (8/16) and they were often yellowish with hyphate edges (vs ring infiltrates only, which are seen in the patients with Acanthamoeba alone). Only 2 patients were contact lens wearers: however, they presented with history of trauma. CONCLUSIONS Acanthamoeba coinfections are much more frequent and are not restricted to contact lens users. Anticipating coinfections is necessary for establishing a diagnosis as well as for appropriate and timely therapeutic interventions.
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The 'Amoeboid Predator-Fungal Animal Virulence' Hypothesis. J Fungi (Basel) 2019; 5:jof5010010. [PMID: 30669554 PMCID: PMC6463022 DOI: 10.3390/jof5010010] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Revised: 01/15/2019] [Accepted: 01/19/2019] [Indexed: 01/22/2023] Open
Abstract
The observation that some aspects of amoeba-fungal interactions resemble animal phagocytic cell-fungal interactions, together with the finding that amoeba passage can enhance the virulence of some pathogenic fungi, has stimulated interest in the amoeba as a model system for the study of fungal virulence. Amoeba provide a relatively easy and cheap model system where multiple variables can be controlled for the study of fungi-protozoal (amoeba) interactions. Consequently, there have been significant efforts to study fungal⁻amoeba interactions in the laboratory, which have already provided new insights into the origin of fungal virulence as well as suggested new avenues for experimentation. In this essay we review the available literature, which highlights the varied nature of amoeba-fungal interactions and suggests some unsolved questions that are potential areas for future investigation. Overall, results from multiple independent groups support the 'amoeboid predator⁻fungal animal virulence hypothesis', which posits that fungal cell predation by amoeba can select for traits that also function during animal infection to promote their survival and thus contribute to virulence.
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Adán C, Magnet A, Fenoy S, Pablos C, Del Águila C, Marugán J. Concomitant inactivation of Acanthamoeba spp. and Escherichia coli using suspended and immobilized TiO 2. WATER RESEARCH 2018; 144:512-521. [PMID: 30081334 DOI: 10.1016/j.watres.2018.07.060] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 07/18/2018] [Accepted: 07/25/2018] [Indexed: 06/08/2023]
Abstract
This work reports the application of photocatalytic disinfection to the inactivation of Acanthamoeba trophozoites, a free-living pathogenic amoeba. Two types of photocatalytic reactors configurations have been used: i) a slurry reactor using suspended titanium dioxide (TiO2); and, ii) a fixed-bed reactor using immobilized TiO2 onto glass Raschig rings. The effect of the chemical composition of water has been analysed, comparing the efficiency of the process in deionized water (DW) and synthetic wastewater treatment plant effluent (SWTPE). The inactivation of Acanthamoeba spp. has been compared to that of Escherichia coli bacteria, being also analysed the concomitant inactivation of both microorganisms. Our results show that 99% of inactivation of E. coli and Acanthamoeba spp. can be achieved using photocatalysis in both reactor configurations, but interestingly, the kinetics of inactivation of both microorganisms together differs from that found with them separately. Particularly, E. coli seems to be more resistant to the inactivation in the presence of Acanthamoeba spp. which has been justified by the screen effect caused by the bigger size of Acanthamoeba spp. This observation is more pronounced in DW as the composition of the SWTPE prevent the microorganisms from suffering osmotic and/or mechanical stress and protect cellular structures to the attack of reactive oxygen species (ROS). On the other hand, the difference between the inactivation rate of E. coli and Acanthamoeba, points out the importance of the different inactivation mechanisms, suggesting that the entry of small TiO2 particles into the cytoplasm of the Acanthamoeba cells provokes the attack of inner structures and as a consequence a faster inactivation. This mechanism is not possible when the catalyst is immobilized leading to a higher cell resistance to inactivation and consequently lower efficiency of the disinfection process.
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Affiliation(s)
- Cristina Adán
- Department of Chemical and Environmental Technology (ESCET), University Rey Juan Carlos, C/Tulipán s/n, 28933 Móstoles, Madrid, Spain
| | - Angela Magnet
- Laboratorio de Parasitología, Universidad San Pablo-CEU, CEU Universities, Boadilla del Monte (Montepríncipe), Ctra Boadilla del Monte Km. 5.3, 28668 Madrid, Spain
| | - Soledad Fenoy
- Laboratorio de Parasitología, Universidad San Pablo-CEU, CEU Universities, Boadilla del Monte (Montepríncipe), Ctra Boadilla del Monte Km. 5.3, 28668 Madrid, Spain
| | - Cristina Pablos
- Department of Chemical and Environmental Technology (ESCET), University Rey Juan Carlos, C/Tulipán s/n, 28933 Móstoles, Madrid, Spain
| | - Carmen Del Águila
- Laboratorio de Parasitología, Universidad San Pablo-CEU, CEU Universities, Boadilla del Monte (Montepríncipe), Ctra Boadilla del Monte Km. 5.3, 28668 Madrid, Spain
| | - Javier Marugán
- Department of Chemical and Environmental Technology (ESCET), University Rey Juan Carlos, C/Tulipán s/n, 28933 Móstoles, Madrid, Spain.
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Contact lens-related polymicrobial keratitis: Acanthamoeba spp. genotype T4 and Candida albicans. Parasitol Res 2018; 117:3431-3436. [PMID: 30094541 DOI: 10.1007/s00436-018-6037-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 07/30/2018] [Indexed: 10/28/2022]
Abstract
A 31-year-old female daily user of contact lenses sought medical attention, reporting blurred vision and irritation of the left eye. Slit-lamp examination revealed hyperemia and an irregular corneal epithelium surface, and empirical treatment was started. A corneal scrape was obtained and examined for the presence of fungi, bacteria, and Acanthamoeba spp. The results of the microbial culture revealed growth of Acanthamoeba spp. and Candida albicans. The Acanthamoeba isolate was characterized by cyst morphology as belonging to group II according to Pussard and Pons. Sequencing of the diagnostic fragment 3 (DF3) region located on the 18S ribosomal DNA identified the isolate as genotype T4. The patient was treated with chlorhexidine 0.02% and polyhexamethylene biguanide (PHMB) 0.02% drops for 5 months until the infection resolved. Lately, rare cases of polymicrobial keratitis associated with Acanthamoeba and Candida albicans have been reported. Cases of co-infection are more difficult to treat, since the specific treatment depends on precise identification of the agents involved.
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Joseph J, Chaurasia S, Sharma S. Case Report: Corneal Coinfection with Fungus and Amoeba: Report of Two Patients and Literature Review. Am J Trop Med Hyg 2018; 99:805-808. [PMID: 30014813 DOI: 10.4269/ajtmh.18-0158] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
We report two cases of corneal coinfection with Acanthamoeba and Fusarium sp. along with the review of published literature. A 35-year-old woman and 65-year-old man presented to the institute with corneal ulcer refractory for treatment with topical antibiotics. Microbiological examination revealed the presence of Acanthamoeba cysts along with septate, hyaline fungal filaments. After emergency therapeutic penetrating keratoplasty (TPK) in both, the corneal tissue was sent for histopathologic examination, which confirmed the presence of Acanthamoeba and fungal coinfection. One patient had a recurrence of fungal infection after TPK. In subjects with a rapid progression of mycotic ulcer, coinfection with other microorganisms including Acanthamoeba should be suspected. The two cases presented here emphasize the importance of microbiology in making prompt diagnosis and appropriate management of these cases at an early stage.
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Affiliation(s)
- Joveeta Joseph
- Jhaveri Microbiology Centre, Brien Holden Eye Research Centre, L. V. Prasad Eye Institute, Hyderabad, India
| | - Sunita Chaurasia
- Tej Kohli Cornea Institute, L. V. Prasad Eye Institute, Hyderabad, India
| | - Savitri Sharma
- Jhaveri Microbiology Centre, Brien Holden Eye Research Centre, L. V. Prasad Eye Institute, Hyderabad, India
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Diagnostic Evaluation of Co-Occurrence of Acanthamoeba and Fungi in Keratitis: A Preliminary Report. Cornea 2018; 37:227-234. [PMID: 29111995 DOI: 10.1097/ico.0000000000001441] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
PURPOSE To test the hypothesis that the coexistence of Acanthamoeba with other forms of microbial keratitis, especially fungal keratitis (FK), is more prevalent than suspected. METHODS A prospective diagnostic study whereby patients presenting with stromal keratitis were additionally tested for Acanthamoeba, irrespective of the initial diagnosis. In addition to the routine workup with Gram stain, KOH mount, and cultures on blood agar and potato dextrose agar, nonnutrient agar was included. Confocal microscopy was performed where feasible. Samples for polymerase chain reaction studies were also obtained. We present the preliminary report of the first 100 culture-positive cases. The primary outcome measured was the number of coexistent Acanthamoeba and FK. The secondary outcomes were the total number of Acanthamoeba cases detected and the correlation between clinical diagnosis and microbiological observations. RESULTS Of the first 100 cases, 22 were culture positive for Acanthamoeba, of which 9 were associated with concurrent FK, 5 with bacterial keratitis, and 8 in isolation. However, only 2 cases were diagnosed clinically as Acanthamoeba, whereas 5 were Acanthamoeba suspects. An additional 4 cases of fungal/Acanthamoeba coexistence in keratitis were revealed purely by confocal microscopy. CONCLUSIONS Acanthamoeba can coexist with other forms of microbial keratitis. The frequency of infection coexistent or otherwise is higher than reported, and the possibility of coinfection must be considered especially in unresponsive cases. Including nonnutrient agar and confocal microscopy in all cases of keratitis would perhaps translate into better treatment strategies and outcomes.
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