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Loufouma-Mbouaka A, Martín-Pérez T, Köhsler M, Danisman Z, Schwarz M, Mazumdar R, Samba-Louaka A, Walochnik J. Characterization of novel extracellular proteases produced by Acanthamoeba castellanii after contact with human corneal epithelial cells and their relevance to pathogenesis. Parasit Vectors 2024; 17:242. [PMID: 38812022 PMCID: PMC11137893 DOI: 10.1186/s13071-024-06304-7] [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: 02/23/2024] [Accepted: 04/24/2024] [Indexed: 05/31/2024] Open
Abstract
BACKGROUND Proteases produced by Acanthamoeba spp. play an important role in their virulence and may be the key to understanding Acanthamoeba pathogenesis; thus, increasing attention has been directed towards these proteins. The present study aimed to investigate the lytic factors produced by Acanthamoeba castellanii during the first hours of in vitro co-culture with human corneal epithelial cells (HCECs). METHODS We used one old and one recent Acanthamoeba isolate, both from patients with severe keratitis, and subsets of these strains with enhanced pathogenic potential induced by sequential passaging over HCEC monolayers. The proteolytic profiles of all strains and substrains were examined using 1D in-gel zymography. RESULTS We observed the activity of additional proteases (ranging from 33 to 50 kDa) during the early interaction phase between amoebae and HCECs, which were only expressed for a short time. Based on their susceptibilities to protease inhibitors, these proteases were characterized as serine proteases. Protease activities showed a sharp decline after 4 h of co-incubation. Interestingly, the expression of Acanthamoeba mannose-binding protein did not differ between amoebae in monoculture and those in co-culture. Moreover, we observed the activation of matrix metalloproteinases in HCECs after contact with Acanthamoeba. CONCLUSIONS This study revealed the involvement of two novel serine proteases in Acanthamoeba pathogenesis and suggests a pivotal role of serine proteases during Acanthamoeba-host cell interaction, contributing to cell adhesion and lysis.
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Affiliation(s)
- Alvie Loufouma-Mbouaka
- Center for Pathophysiology, Infectiology and Immunology, Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Tania Martín-Pérez
- Center for Pathophysiology, Infectiology and Immunology, Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Martina Köhsler
- Center for Pathophysiology, Infectiology and Immunology, Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Zeynep Danisman
- Center for Pathophysiology, Infectiology and Immunology, Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Maya Schwarz
- Center for Pathophysiology, Infectiology and Immunology, Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Rounik Mazumdar
- Max Perutz Labs Vienna, Department of Medical Biochemistry, Medical University of Vienna, Vienna, Austria
- GenomeByte Ltd, London, UK
| | - Ascel Samba-Louaka
- Laboratoire Ecologie Et Biologie Des Interactions, Université de Poitiers, UMR CNRS, 7267, Poitiers, France
| | - Julia Walochnik
- Center for Pathophysiology, Infectiology and Immunology, Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria.
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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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Alreshidi SO, Vargas JM, Ahmad K, Alothman AY, Albalawi ED, Almulhim A, Alenezi SH, ALBalawi HB, Alali NM, Hashem F, Aljindan M. Differentiation of acanthamoeba keratitis from other non-acanthamoeba keratitis: Risk factors and clinical features. PLoS One 2024; 19:e0299492. [PMID: 38470877 DOI: 10.1371/journal.pone.0299492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 02/11/2024] [Indexed: 03/14/2024] Open
Abstract
INTRODUCTION Infectious Keratitis is one of the most common ocular emergencies seen by ophthalmologists. Our aim is to identify the risk factors and clinical features of Acanthamoeba Keratitis (AK). METHODS This retrospective chart review study was conducted at King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia, and included all the microbial keratitis cases, male and female patients of all ages. The main outcome is the differentiation between various microbial keratitis types. RESULTS We included 134 consecutive eyes of 126 persons. We had 24 cases of acanthamoeba keratitis, 22 bacterial keratitis, 24 fungal keratitis, 32 herpetic keratitis, and 32 bacterial co-infection. Contact lens wear was found in 33 eyes (24.6%). Among acanthamoeba keratitis patients, 73% were ≤ 39 years of age, and 73% were females (P <0.001). Also, in AK cases, epithelial defect was found in all cases (100%), endothelial plaques were found in 18 eyes (69.2%), 12 cases had radial keratoneuritis (46.2%), and ring infiltrate was found in 53.8% of AK cases. CONCLUSIONS We determined the factors that increase the risk of acanthamoeba infection and the clinical characteristics that help distinguish it from other types of microbial keratitis. Our findings suggest that younger females and patients who wear contact lenses are more likely to develop acanthamoeba keratitis. The occurrence of epitheliopathy, ring infiltrate, radial keratoneuritis, and endothelial plaques indicate the possibility of acanthamoeba infection. Promoting education on wearing contact lenses is essential to reduce the risk of acanthamoeba infection, as it is the most significant risk factor for this infection.
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Affiliation(s)
| | - José Manuel Vargas
- Cornea, External Diseases Section, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- Ophthalmology Division, King Abdullah Bin Abdulaziz University Hospital, Riyadh, Saudi Arabia
| | - Khabir Ahmad
- Research Department, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia
| | - Ahmed Yousef Alothman
- Ophthalmology Department, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Eman D Albalawi
- Clinical Sciences Department, College of Medicine, Princess Noura Bint Abdulrahman University, Riyadh, Saudi Arabia
| | - Abdulmohsen Almulhim
- Department of Ophthalmology, College of Medicine, Jouf University, Sakakah, Saudi Arabia
| | - Saad Hamdan Alenezi
- Ophthalmology Department, College of Medicine, Majmaah University, Majmaah, Saudi Arabia
| | - Hani Basher ALBalawi
- Department of Surgery, Division of Ophthalmology, Faculty of Medicine, University of Tabuk, Tabuk, Saudi Arabia
| | - Naif Mamdouh Alali
- Department of Surgery, Division of Ophthalmology, Faculty of Medicine, University of Tabuk, Tabuk, Saudi Arabia
| | - Faris Hashem
- Department of Surgery, Division of Ophthalmology, Faculty of Medicine, University of Tabuk, Tabuk, Saudi Arabia
| | - Mohanna Aljindan
- Ophthalmology Department, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
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Pang J, Wei Z, Wang L, Guo X, Chen Q, Wei Y, Peng Y, Zhang Z, Zhang Y, Liu J, Cheng Z, Wang Z, Zhang Y, Chen K, Xu X, Lu X, Liang Q. Acanthamoeba Keratitis in China: Genotypic and Clinical Correlations. Transl Vis Sci Technol 2024; 13:5. [PMID: 38329750 PMCID: PMC10860683 DOI: 10.1167/tvst.13.2.5] [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: 10/16/2023] [Accepted: 12/31/2023] [Indexed: 02/09/2024] Open
Abstract
Purpose To investigate the relationship between Acanthamoeba genotypes, clinical manifestations, and outcomes in Acanthamoeba keratitis (AK) patients. Methods This retrospective study included 159 culture-confirmed AK patients. Patients' data were collected, including demographics, initial diagnosis, treatments, and clinical features. The genotype of Acanthamoeba was identified through sequencing the Diagnostic Fragment 3 (DF3) region in the small ribosomal subunit RNA genes. The phylogenetic tree was constructed using the ClustalW model and maximum likelihood method. Cases with "poor outcome" were defined based on specific clinical criteria, including corneal perforation, keratoplasty, other eye surgery, duration of anti-amoebic therapy ≥8.0 months, and final visual acuity ≤20/80. "Better outcome" cases were the remainder. The correlation between T4 subtypes, clinical phenotypes, and clinical prognosis were further analyzed. Results In this study, AK was primarily attributed to the T4A genotype, with a positive correlation between geographical and genetic distances. The primary clinical associated with T4 subtypes was deep stromal infiltration. Results was also showed a significant association between T4 subtypes and clinical outcomes (P = 0.021). Further analysis revealed that T4C was closely associated with a better prognosis (P = 0.040) and T4D with worse outcomes (P = 0.013). Conclusions In China, AK was predominantly caused by the T4A subtype. Geographical distance positively correlated with genetic distance. Clinical prognosis varied among different subtypes, notably in T4C and T4D. Translational Relevance This study demonstrated the association between T4 subtypes and clinical phenotypes, as well as the effects of T4 subtypes on clinical prognosis.
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Affiliation(s)
- Jinding Pang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Zhenyu Wei
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Leying Wang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Xiaoyan Guo
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Qiankun Chen
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Yuan Wei
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Yan Peng
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Zijun Zhang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Yuheng Zhang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Jiamin Liu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Zhen Cheng
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Zhiqun Wang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Yang Zhang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Kexin Chen
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Xizhan Xu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Xinxin Lu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Qingfeng Liang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
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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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Przybek-Skrzypecka J, Walkden A, Brahma A, Chidambaram J, Carley FM. Impact of First Healthcare Provider on Acanthamoeba Keratitis Course: How to Overcome Poor Prognosis in Acanthamoeba Keratitis Treatment? A Single Tertiary Center, Observational Study. Clin Ophthalmol 2023; 17:3975-3982. [PMID: 38146454 PMCID: PMC10749575 DOI: 10.2147/opth.s438990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 12/07/2023] [Indexed: 12/27/2023] Open
Abstract
Background To assess the difference in course and final visual outcome of Acanthamoeba keratitis (AK) patients based on the first healthcare provider (HCP) seen. Methods Retrospective observational cohort study of AK patients admitted to the Manchester Royal Eye Hospital between 2003 and 2017. HCPs were grouped (Group 1: Optometrists, Opticians; Group 2: General Practitioners (GPs); Group 3: Ophthalmologists) and the data analyzed on demographics, risk factors, clinical history, clinical features, and Acanthamoeba subspecies. Results Forty-one patients with unilateral culture-proven AK were included. Median time to consultation with first HCP was 7 days (IQR 4-14 days), while mean time to the correct diagnosis of AK was 15 days (IQR 7-29 days). Patients saw an optician, optometrist or ophthalmologists significantly earlier than GPs (median 4 days, vs 15 or 5 days, respectively, p = 0.04). Bacterial keratitis was the most common initial clinical diagnosis (43%). The shortest time to making the AK diagnosis (median 11 days) and the highest rate of initiating AK treatment started at the first visit (38%) were both in the ophthalmologists' group. No significant differences were observed in initial and final visual acuity between HCP groups (p = 0.36). Conclusion AK patients often seek ocular help earlier from optometrists and opticians than medical doctors. Final clinical outcomes did not significantly differ based on the first HCP seen, but ophthalmologists were more likely to make the diagnosis of AK and initiate anti-amoebal therapy faster than other HCPs. Greater education and collaboration between ophthalmologists and other HCPs to increase awareness of AK are needed.
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Affiliation(s)
- Joanna Przybek-Skrzypecka
- Department of Ophthalmology, Medical University of Warsaw, Warsaw, Poland
- SPKSO Ophthalmic University Hospital, Warsaw, Poland
| | - Andrew Walkden
- Cornea Department, Manchester Royal Eye Hospital, Manchester University NHS Foundation, Manchester, UK
- School of Biological Science, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Arun Brahma
- Cornea Department, Manchester Royal Eye Hospital, Manchester University NHS Foundation, Manchester, UK
| | - Jaya Chidambaram
- Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Fiona M Carley
- Cornea Department, Manchester Royal Eye Hospital, Manchester University NHS Foundation, Manchester, UK
- School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
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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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Sarink MJ, Koelewijn R, Stelma F, Kortbeek T, van Lieshout L, Smit PW, Tielens AGM, van Hellemond JJ. An International External Quality Assessment Scheme to Assess the Diagnostic Performance of Polymerase Chain Reaction Detection of Acanthamoeba Keratitis. Cornea 2023; 42:1027-1033. [PMID: 37155347 PMCID: PMC10306335 DOI: 10.1097/ico.0000000000003275] [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: 11/27/2022] [Revised: 02/04/2023] [Accepted: 02/16/2023] [Indexed: 05/10/2023]
Abstract
PURPOSE The purpose of this study was to assess the variation in methods and to determine whether an External Quality Assessment Scheme (EQAS) for polymerase chain reaction (PCR) detection of Acanthamoeba keratitis is valuable for the diagnostic process. METHODS A multicenter EQAS was introduced, covering 16 diagnostic laboratories. Using Acanthamoeba castellanii ATCC strain 30010, 3 sets of samples were prepared, containing different amounts of DNA, cysts, or trophozoites. Samples were masked and sent to the participants with instructions for use and a questionnaire concerning the applied methodologies. Special attention in this questionnaire was given to the used pretreatment methods to assess existing variations in these procedures. RESULTS A large variation in the methodologies and substantial differences in the diagnostic performance were found between participants. In contrast to the DNA samples where all participants had a perfect score, several false negative results were reported for the samples containing cysts or trophozoites. Only 9 participants had an optimal score, whereas one participant reported all samples as negative, one participant reported failures due to inhibition, and the other 5 reported in total 7 false negative results. A clear correlation was noticed between the PCR detection rate and the number of cysts or trophozoites in the sample. CONCLUSIONS The results indicate that a pretreatment procedure can be a risky step in PCR-based detections of Acanthamoeba , but it improves the sensitivity and reliability, especially of samples containing cysts. Therefore, participation in an EQAS is informative for routine diagnostic laboratories and can assist in improving the laboratory procedures used for the diagnosis of Acanthamoeba keratitis.
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Affiliation(s)
- Maarten J. Sarink
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC University Medical Center, Rotterdam, the Netherlands
| | - Rob Koelewijn
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC University Medical Center, Rotterdam, the Netherlands
| | - Foekje Stelma
- Department of Medical Microbiology, Radboudumc Nijmegen, the Netherlands
| | - Titia Kortbeek
- National Institute of Public Health and the Environment, RIVM, Bilthoven, the Netherlands
| | - Lisette van Lieshout
- Department of Parasitology, Leiden University Medical Centre, Leiden, the Netherlands; and
| | - Pieter W. Smit
- Department of Medical Microbiology, Molecular Diagnostics Unit, Maasstad Hospital, Rotterdam, the Netherlands
| | - Aloysius G. M. Tielens
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC University Medical Center, Rotterdam, the Netherlands
| | - Jaap J. van Hellemond
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC University Medical Center, Rotterdam, the Netherlands
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Loufouma Mbouaka A, Lesiak-Markowicz I, Heredero-Bermejo I, Mazumdar R, Walochnik J, Martín-Pérez T. Assessing Acanthamoeba cytotoxicity: comparison of common cell viability assays. Front Microbiol 2023; 14:1175469. [PMID: 37180263 PMCID: PMC10167018 DOI: 10.3389/fmicb.2023.1175469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 04/03/2023] [Indexed: 05/16/2023] Open
Abstract
Background In vitro models for studying interactions between Acanthamoeba and host cells are crucial for understanding the pathomechanism of Acanthamoeba and assessing differences between strains and cell types. The virulence of Acanthamoeba strains is usually assessed and monitored by using cell cytotoxicity assays. The aim of the present study was to evaluate and compare the most widely used cytotoxicity assays for their suitability to assess Acanthamoeba cytopathogenicity. Methods The viability of human corneal epithelial cells (HCECs) after co-culture with Acanthamoeba was evaluated in phase contrast microscopy. Results It was shown that Acanthamoeba is unable to considerably reduce the tetrazolium salt and the NanoLuc® Luciferase prosubstrate to formazan and the luciferase substrate, respectively. This incapacity helped to generate a cell density-dependent signal allowing to accurately quantify Acanthamoeba cytotoxicity. The lactate dehydrogenase (LDH) assay led to an underestimation of the cytotoxic effect of Acanthamoeba on HCECs since their co-incubation negatively affected the lactate dehydrogenase activity. Discussion Our findings demonstrate that cell-based assays using the aqueous soluble tetrazolium-formazan, and the NanoLuc® Luciferase prosubstrate products, in contrast to LDH, are excellent markers to monitor the interaction of Acanthamoeba with human cell lines and to determine and quantify effectively the cytotoxic effect induced by the amoebae. Furthermore, our data indicate that protease activity may have an impact on the outcome and thus the reliability of these tests.
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Affiliation(s)
- Alvie Loufouma Mbouaka
- Center for Pathophysiology, Infectiology and Immunology, Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Iwona Lesiak-Markowicz
- Center for Pathophysiology, Infectiology and Immunology, Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Irene Heredero-Bermejo
- Department of Biomedicine and Biotechnology, Faculty of Pharmacy, University of Alcalá, Madrid, Spain
| | - Rounik Mazumdar
- Max Perutz Labs Vienna, Department of Medical Biochemistry, Medical University of Vienna, Vienna, Austria
| | - Julia Walochnik
- Center for Pathophysiology, Infectiology and Immunology, Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Tania Martín-Pérez
- Center for Pathophysiology, Infectiology and Immunology, Institute of Specific Prophylaxis and Tropical Medicine, Medical University of Vienna, Vienna, Austria
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10
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Impact of implementation of polymerase chain reaction on diagnosis, treatment, and clinical course of Acanthamoeba keratitis. Graefes Arch Clin Exp Ophthalmol 2023:10.1007/s00417-023-05993-7. [PMID: 36795161 DOI: 10.1007/s00417-023-05993-7] [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: 06/08/2022] [Revised: 01/24/2023] [Accepted: 01/31/2023] [Indexed: 02/17/2023] Open
Abstract
PURPOSE Acanthamoeba keratitis (AK) is a painful and possibly sight-threatening ocular infection. While the correct diagnosis and specific treatment in the early stages significantly improve the prognosis, the disease is often misdiagnosed and in clinical examination confused with other forms of keratitis. Polymerase chain reaction (PCR) for the detection of AK was first introduced in our institution in December 2013 to improve the timely diagnosis of AK. The aim of this study was to assess the impact of implementation of Acanthamoeba PCR on the diagnosis and treatment of the disease in a German tertiary referral center. PATIENTS AND METHODS Patients treated for Acanthamoeba keratitis between 1st of January 1993 and 31st of December 2021 in the Department of Ophthalmology of the University Hospital Duesseldorf were identified retrospectively via in-house registries. Evaluated parameters include age, sex, initial diagnosis, method of correct diagnosis, duration of symptoms until correct diagnosis, contact lens use, visual acuity, and clinical findings as well as medical and surgical therapy by keratoplasty (pKP). In order to assess the impact of implementation of Acanthamoeba PCR, the cases were divided into two groups (before (pre-PCR group) and after PCR implementation (PCR group). RESULTS Seventy-five patients with Acanthamoeba keratitis were included (69.3% female, median age 37 years). Eighty-four percent (63/75) of all patients were contact lens wearers. Until PCR was available, 58 patients with Acanthamoeba keratitis were diagnosed either clinically (n = 28), by histology (n = 21), culture (n = 6), or confocal microscopy (n = 2) with a median duration until diagnosis of 68 (18; 109) days. After PCR implementation, in 17 patients, the diagnosis was established with PCR in 94% (n = 16) and median duration until diagnosis was significantly shorter with 15 (10; 30.5) days. A longer duration until correct diagnosis correlated with a worse initial visual acuity (p = 0.0019, r = 0.363). The number of pKP performed was significantly lower in the PCR group (5/17; 29.4%) than in the pre-PCR group (35/58; 60.3%) (p = 0.025). CONCLUSIONS The choice of diagnostic method and especially the application of PCR have a significant impact on the time to diagnosis and on the clinical findings at the time of confirmation of diagnosis and the need for penetrating keratoplasty. In contact lens-associated keratitis, the first crucial step is to take AK into consideration and perform a PCR test as timely confirmation of diagnosis of AK is imperative to prevent long-term ocular morbidity.
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11
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Richardson QR, Prajna L, Elakkiya S, Kamal FS, Talbott M, Prajna NV, Rajaraman R, Cevallos V, Seitzman GD, Lietman TM, Keenan JD. Antiamoebic Susceptibility in Acanthamoeba Keratitis: Comparison of Isolates From South India and Northern California. Cornea 2023; 42:110-112. [PMID: 36036669 PMCID: PMC9722490 DOI: 10.1097/ico.0000000000003060] [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: 01/18/2022] [Accepted: 03/14/2022] [Indexed: 11/26/2022]
Abstract
PURPOSE Outcomes of Acanthamoeba keratitis are often worse in India than in the United States. The goal of this study was to determine whether antiamoebic susceptibility patterns were different when comparing Acanthamoeba isolates from India with those of the United States. METHODS Acanthamoeba isolates were obtained from corneal scrapings of 43 patients with infectious keratitis seen at the Francis I. Proctor Foundation (N = 23) and Aravind Eye Hospital (N = 20) from 2008 through 2012 and plated on growth media. A previously described minimum cysticidal concentration (MCC) assay was performed by a single laboratory technician to assess susceptibility to 5 antiamoebic agents for all isolates. Testing was conducted in triplicate, with the median MCC chosen for analyses. RESULTS The MCC (μg/mL) of polyhexamethylene biguanide was 6.25 [IQR 5.47-12.5] for Aravind isolates and 6.25 [IQR 6.25-9.375] for Proctor isolates ( P = 0.75), corresponding values were 6.25 [IQR 3.125-6.25] and 3.125 [IQR 3.125-9.375] for chlorhexidine ( P = 0.81), 2500 [IQR 2500-5000] and 5000 [IQR 1250-20,000] for voriconazole ( P = 0.25), 15.6 [IQR 15.6-39.0625] and 15.6 [IQR 15.6-31.25] for hexamidine ( P = 0.92), and 15.6 [IQR 7.81-15.6] and 15.6 [IQR 7.81-31.25] for propamidine ( P = 0.42). CONCLUSIONS This study found no statistically significant differences in antiamoebic susceptibility of Indian versus US samples from Acanthamoeba keratitis clinical isolates. These findings suggest that differences in antiamoebic susceptibility are likely not responsible for differential outcomes in Acanthamoeba keratitis between the 2 locations.
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Affiliation(s)
- Quintin R Richardson
- Francis I. Proctor Foundation, University of California, San Francisco, San Francisco, CA
| | | | | | | | - Maya Talbott
- Francis I. Proctor Foundation, University of California, San Francisco, San Francisco, CA
| | | | - Revathi Rajaraman
- Department of Cornea, Aravind Eye Hospital Coimbatore, Madurai, India ; and
| | - Vicky Cevallos
- Francis I. Proctor Foundation, University of California, San Francisco, San Francisco, CA
| | - Gerami D Seitzman
- Francis I. Proctor Foundation, University of California, San Francisco, San Francisco, CA
- Department of Ophthalmology, University of California, San Francisco, San Francisco, CA
| | - Thomas M Lietman
- Francis I. Proctor Foundation, University of California, San Francisco, San Francisco, CA
- Department of Ophthalmology, University of California, San Francisco, San Francisco, CA
| | - Jeremy D Keenan
- Francis I. Proctor Foundation, University of California, San Francisco, San Francisco, CA
- Department of Ophthalmology, University of California, San Francisco, San Francisco, CA
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12
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The Anti-Amoebic Activity of a Peptidomimetic against Acanthamoeba castellanii. Microorganisms 2022; 10:microorganisms10122377. [PMID: 36557630 PMCID: PMC9782699 DOI: 10.3390/microorganisms10122377] [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: 11/11/2022] [Revised: 11/27/2022] [Accepted: 11/29/2022] [Indexed: 12/05/2022] Open
Abstract
Acanthamoeba is a free-living protozoan known to cause keratitis most commonly, especially among contact lens wearers. Treatment of Acanthamoeba keratitis is challenging as Acanthamoeba can encyst from the active form, a trophozoite, into a hibernating cyst that is refractory to antibiotics and difficult to kill; therefore, there is a need for more effective anti-amoebic strategies. In this study, we have evaluated the anti-amoebic activity of the antimicrobial peptide mimic RK-758 against Acanthamoeba castellanii. RK-758 peptidomimetic was subjected to biological assays to investigate its amoebicidal, amoebistatic, anti-encystation, and anti-excystation effects on A. castellanii. The anti-amoebic activity of the peptide mimic RK-758 was compared with chlorhexidine against the Acanthamoeba castellanii ATCC30868 and Acanthamoeba castellanii 044 (a clinical strain) with the concentrations of both ranging from 125 µM down to 7.81 µM. All experiments were performed in duplicate with three independent replicates. The data were represented as mean ± SE and analysed using a two-sample t-test and two-tailed distributions. A p < 0.05 was considered statistically significant. The peptidomimetic RK-758 had anti-Acanthamoeba activity against both trophozoites and cysts in a dose-dependent manner. The RK-758 had amoebicidal and growth inhibitory activities of ≥50% at a concentration between 125 µM and 15.6 µM against the trophozoites of both Acanthamoeba strains. Inhibitory effects on the cyst formation and trophozoite re-emergence from cysts were noted at similar concentrations. Chlorhexidine had 50% activity at 7.81 µM and above against the trophozoites and cysts of both strains. In the haemolysis assay, the RK-758 lysed horse RBCs at concentrations greater than 50 µM whereas lysis occurred at concentrations greater than 125 µM for the chlorhexidine. The peptidomimetic RK-758, therefore, has activity against both the trophozoite and cyst forms of Acanthamoeba and has the potential to be further developed as an anti-microbial agent against Acanthamoeba. RK-758 may also have use as an anti-amoebic disinfectant in contact lens solutions.
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13
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The Activity of Polyhomoarginine against Acanthamoeba castellanii. BIOLOGY 2022; 11:biology11121726. [PMID: 36552236 PMCID: PMC9774714 DOI: 10.3390/biology11121726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Revised: 11/18/2022] [Accepted: 11/24/2022] [Indexed: 11/30/2022]
Abstract
Arginine-rich peptides can have broad-spectrum anti-bacterial and anti-fungal activities. Polyhomoarginine consists of highly cationic residues which can act on the negatively charged microbial cell membranes. Acanthamoeba is a free-living protozoan known to cause a rare corneal infection which is difficult to diagnose and treat. This study evaluated the activity of the polyhomoarginines against Acanthamoeba castellanii. Acanthamoeba amoebicidal, amoebistatic, encystation and excystment assays were performed using protocols described in the literature. The activity of polyhomoarginines (PHAs) of different lengths (10 to 400 residues) was measured against the trophozoites and cysts of Acanthamoeba castellanii ATCC30868 in concentrations ranging from 0.93 μM to 15 μM. Data were represented as mean ± SE and analysed using one-way ANOVA. Overall, PHAs demonstrated good anti-acanthamoeba activity against both trophozoites and cysts. PHA 30 reduced the number of viable trophozoites by 99%, inhibited the formation of cysts by 96% and the emergence of trophozoites from cysts by 67% at 3.75 μM. PHA 10 was similarly active, but at a slightly higher concentration of 15 μM, reducing the numbers of viable trophozoites by 98%, inhibiting cyst formation by 84% and preventing the emergence of trophozoites from cysts by 99%. At their greatest anti-amoeba concentrations, PHA 10 gave only 8% haemolysis at 15 μM while PHA 30 gave <40 % haemolysis at 3.75 μM. Polyhomoarginine 10 showed excellent anti-amoebic activity against both forms of Acanthamoeba castellanii and was non-toxic at its most active concentrations. This implies that polyhomoarginines can be developed into a potential therapeutic agent for Acanthamoeba keratitis. However, there is a need to carry out further pre-clinical and then in vivo experiments in the AK animal model.
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14
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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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15
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Rayamajhee B, Sharma S, Willcox M, Henriquez FL, Rajagopal RN, Shrestha GS, Subedi D, Bagga B, Carnt N. Assessment of genotypes, endosymbionts and clinical characteristics of Acanthamoeba recovered from ocular infection. BMC Infect Dis 2022; 22:757. [PMID: 36175838 PMCID: PMC9520893 DOI: 10.1186/s12879-022-07741-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 09/12/2022] [Indexed: 11/22/2022] Open
Abstract
Introduction Acanthamoeba is an emerging pathogen, infamous for its resilience against antiprotozoal compounds, disinfectants and harsh environments. It is known to cause keratitis, a sight-threatening, painful and difficult to treat corneal infection which is often reported among contact lens wearers and patients with ocular trauma. Acanthamoeba comprises over 24 species and currently 23 genotypes (T1-T23) have been identified. Aims This retrospective study was designed to examine the Acanthamoeba species and genotypes recovered from patients with Acanthamoeba keratitis (AK), determine the presence of endosymbionts in ocular isolates of Acanthamoeba and review the clinical presentations. Methodology Thirteen culture-confirmed AK patients treated in a tertiary eye care facility in Hyderabad, India from February to October 2020 were included in this study. The clinical manifestations, medications and visual outcomes of all patients were obtained from medical records. The Acanthamoeba isolates were identified by sequencing the ribosomal nuclear subunit (rns) gene. Acanthamoeba isolates were assessed for the presence of bacterial or fungal endosymbionts using molecular assays, PCR and fluorescence in situ hybridization (FISH). Results The mean age of the patients was 33 years (SD ± 17.4; 95% CI 22.5 to 43.5 years). Six (46.2%) cases had AK associated risk factors; four patients had ocular trauma and two were contact lens wearers. A. culbertsoni (6/13, 46.2%) was the most common species, followed by A. polyphaga and A. triangularis. Most of the isolates (12/13) belonged to genotype T4 and one was a T12; three sub-clusters T4A, T4B, and T4F were identified within the T4 genotype. There was no significant association between Acanthamoeba types and clinical outcomes. Eight (61.5%) isolates harboured intracellular bacteria and one contained Malassezia restricta. The presence of intracellular microbes was associated with a higher proportion of stromal infiltrates (88.9%, 8/9), epithelial defect (55.6%, 5/9) and hypopyon (55.6%, 5/9) compared to 50% (2/4), 25% (1/4) and 25% (1/4) AK cases without intracellular microbes, respectively. Conclusions Genotype T4 was the predominant isolate in southern India. This is the second report of T12 genotype identified from AK patient in India, which is rarely reported worldwide. The majority of the Acanthamoeba clinical isolates in this study harboured intracellular microbes, which may impact clinical characteristics of AK. Supplementary Information The online version contains supplementary material available at 10.1186/s12879-022-07741-4.
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Affiliation(s)
- Binod Rayamajhee
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia.
| | - Savitri Sharma
- Jhaveri Microbiology Centre, Prof. Brien Holden Eye Research Centre, Hyderabad Eye Research Foundation, L. V. Prasad Eye Institute (LVPEI), Kallam Anji Reddy Campus, Hyderabad, India
| | - Mark Willcox
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
| | - Fiona L Henriquez
- Institute of Biomedical and Environmental Health Research, School of Health and Life Sciences, University of the West of Scotland (UWS), Paisley, PA1 2BE, Scotland, UK
| | | | - Gauri Shankar Shrestha
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
| | - Dinesh Subedi
- School of Biological Sciences, Monash University, Clayton, VIC, 3800, Australia
| | - Bhupesh Bagga
- The Cornea Institute, L V Prasad Eye Institute, Banjara Hills, Hyderabad, India
| | - Nicole Carnt
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
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16
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Ahmed NH, Rathod PG, Satpathy G, Tandon R, Sharma N, Titiyal JS. Acanthamoeba keratitis: Experience from a tertiary eye care center in North India. Trop Parasitol 2022; 12:119-123. [PMID: 36643983 PMCID: PMC9832494 DOI: 10.4103/tp.tp_16_22] [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: 02/28/2022] [Revised: 05/29/2022] [Accepted: 06/29/2022] [Indexed: 11/25/2022] Open
Abstract
The free-living amebae of genus Acanthamoeba are an important cause of microbial keratitis. The clinical appearance of Acanthamoeba keratitis (AK) usually mimics viral or fungal keratitis. Thus, microbiological workup plays a significant role in the diagnosis and timely treatment of such cases. We report a retrospective case series of seven culture-confirmed AK cases from a tertiary eye care center in North India. Various risk factors and triggers of infection, clinical presentations, microbiological findings, and management of AK are elucidated.
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Affiliation(s)
- Nishat Hussain Ahmed
- Department of Ocular Microbiology, Dr. R. P. Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Prachala G Rathod
- Department of Ocular Microbiology, Dr. R. P. Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Gita Satpathy
- Department of Ocular Microbiology, Dr. R. P. Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Radhika Tandon
- Department of Ophthalmology, Dr. R. P. Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Namrata Sharma
- Department of Ophthalmology, Dr. R. P. Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
| | - Jeewan S Titiyal
- Department of Ophthalmology, Dr. R. P. Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India
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Smith C, Ashraf N, Haghnegahdar M, Goins K, Newman JR. Acanthamoeba Keratitis: A Single-Institution Series of Four Cases With Literature Review. Cureus 2022; 14:e21112. [PMID: 35165570 PMCID: PMC8830394 DOI: 10.7759/cureus.21112] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/06/2022] [Indexed: 11/05/2022] Open
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