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Reyes-Batlle M, Córdoba-Lanús E, Domínguez-de-Barros A, Sifaoui I, Rodríguez-Expósito RL, Mantesa-Rodríguez S, Piñero JE, Lorenzo-Morales J. Reliable and specific detection of Acanthamoeba spp. in dishcloths using quantitative real-time PCR assay. Food Microbiol 2024; 122:104562. [PMID: 38839225 DOI: 10.1016/j.fm.2024.104562] [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: 03/13/2024] [Revised: 05/08/2024] [Accepted: 05/12/2024] [Indexed: 06/07/2024]
Abstract
Acanthamoeba spp., are ubiquitous protist which belongs to Free-Living Amoeba (FLA) group, is considered as causal agent of side-threatening keratitis or fatal encephalitis among other human infections. Besides, this parasite has been reported as host for other microorganisms important to human health such as Campylobacter spp. or Vibrio spp. among others. This role of Acanthamoeba as pathogen and environmental phagocyte has increased the reports confirming its presence in human related environments, acting as a water quality indicator. Considering the tide relationship between water and kitchen environments, and the high prevalence of Acanthamoeba in water sources, the present study aims to establish a quick and accurate protocol based on DNA extraction and a real time qPCR assay to detect Acanthamoeba spp. in dishcloths. The procedure has been validated by processing 17 used dishcloths. Our findings demonstrated the high sensitivity of the qPCR assay used which was capable of detecting up to one Acanthamoeba from an in vitro contaminated dishcloth. The protocol accurately detected 64.7% of positive samples for Acanthamoeba spp, (in 4 samples DNA concentrations corresponded to 1-102 amoebae). Our findings demonstrate the importance of FLA surveillance by efficient and sensitive methods since one amoeba is capable of colonizing human related food environments such as kitchens sinks and could be a potential source of infection.
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Affiliation(s)
- M Reyes-Batlle
- Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias, Universidad de La Laguna, Avenida Astrofísico Francisco Sánchez S/N, 38206 La Laguna, Tenerife, Islas Canarias, Spain; Consorcio Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, 28006, Madrid, Spain; Departamento de Obstetricia y Ginecología, Pediatría, Medicina Preventiva y Salud Pública, Toxicología, Medicina Legal y Forense y Parasitología, Facultad de Ciencias de la Salud, Universidad de La Laguna, Tenerife, Spain.
| | - E Córdoba-Lanús
- Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias, Universidad de La Laguna, Avenida Astrofísico Francisco Sánchez S/N, 38206 La Laguna, Tenerife, Islas Canarias, Spain; Consorcio Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, 28006, Madrid, Spain
| | - A Domínguez-de-Barros
- Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias, Universidad de La Laguna, Avenida Astrofísico Francisco Sánchez S/N, 38206 La Laguna, Tenerife, Islas Canarias, Spain
| | - I Sifaoui
- Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias, Universidad de La Laguna, Avenida Astrofísico Francisco Sánchez S/N, 38206 La Laguna, Tenerife, Islas Canarias, Spain; Consorcio Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, 28006, Madrid, Spain; Departamento de Obstetricia y Ginecología, Pediatría, Medicina Preventiva y Salud Pública, Toxicología, Medicina Legal y Forense y Parasitología, Facultad de Ciencias de la Salud, Universidad de La Laguna, Tenerife, Spain
| | - R L Rodríguez-Expósito
- Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias, Universidad de La Laguna, Avenida Astrofísico Francisco Sánchez S/N, 38206 La Laguna, Tenerife, Islas Canarias, Spain; Consorcio Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, 28006, Madrid, Spain; Departamento de Obstetricia y Ginecología, Pediatría, Medicina Preventiva y Salud Pública, Toxicología, Medicina Legal y Forense y Parasitología, Facultad de Ciencias de la Salud, Universidad de La Laguna, Tenerife, Spain
| | - S Mantesa-Rodríguez
- Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias, Universidad de La Laguna, Avenida Astrofísico Francisco Sánchez S/N, 38206 La Laguna, Tenerife, Islas Canarias, Spain
| | - J E Piñero
- Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias, Universidad de La Laguna, Avenida Astrofísico Francisco Sánchez S/N, 38206 La Laguna, Tenerife, Islas Canarias, Spain; Consorcio Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, 28006, Madrid, Spain; Departamento de Obstetricia y Ginecología, Pediatría, Medicina Preventiva y Salud Pública, Toxicología, Medicina Legal y Forense y Parasitología, Facultad de Ciencias de la Salud, Universidad de La Laguna, Tenerife, Spain
| | - J Lorenzo-Morales
- Instituto Universitario de Enfermedades Tropicales y Salud Pública de Canarias, Universidad de La Laguna, Avenida Astrofísico Francisco Sánchez S/N, 38206 La Laguna, Tenerife, Islas Canarias, Spain; Consorcio Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, 28006, Madrid, Spain; Departamento de Obstetricia y Ginecología, Pediatría, Medicina Preventiva y Salud Pública, Toxicología, Medicina Legal y Forense y Parasitología, Facultad de Ciencias de la Salud, Universidad de La Laguna, Tenerife, Spain
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Ilyas M, Stapleton F, Willcox MDP, Henriquez F, Peguda HK, Rayamajhee B, Zahid T, Petsoglou C, Carnt NA. Epidemiology of and Genetic Factors Associated with Acanthamoeba Keratitis. Pathogens 2024; 13:142. [PMID: 38392880 PMCID: PMC10892102 DOI: 10.3390/pathogens13020142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 01/14/2024] [Accepted: 01/31/2024] [Indexed: 02/25/2024] Open
Abstract
Acanthamoeba keratitis (AK) is a severe, rare protozoal infection of the cornea. Acanthamoeba can survive in diverse habitats and at extreme temperatures. AK is mostly seen in contact lens wearers whose lenses have become contaminated or who have a history of water exposure, and in those without contact lens wear who have experienced recent eye trauma involving contaminated soil or water. Infection usually results in severe eye pain, photophobia, inflammation, and corneal epithelial defects. The pathophysiology of this infection is multifactorial, including the production of cytotoxic proteases by Acanthamoeba that degrades the corneal epithelial basement membrane and induces the death of ocular surface cells, resulting in degradation of the collagen-rich corneal stroma. AK can be prevented by avoiding risk factors, which includes avoiding water contact, such as swimming or showering in contact lenses, and wearing protective goggles when working on the land. AK is mostly treated with an antimicrobial therapy of biguanides alone or in combination with diaminidines, although the commercial availability of these medicines is variable. Other than anti-amoeba therapies, targeting host immune pathways in Acanthamoeba disease may lead to the development of vaccines or antibody therapeutics which could transform the management of AK.
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Affiliation(s)
- Muhammad Ilyas
- Primary & Secondary Healthcare Department, Punjab 54000, Pakistan; (M.I.)
| | - Fiona Stapleton
- School of Optometry and Vision Science, University of NSW, Sydney, NSW 2052, Australia (H.K.P.)
| | - Mark D. P. Willcox
- School of Optometry and Vision Science, University of NSW, Sydney, NSW 2052, Australia (H.K.P.)
| | - Fiona Henriquez
- School of Health and Life Sciences, The University of the West of Scotland, Glasgow G72 0LH, UK
| | - Hari Kumar Peguda
- School of Optometry and Vision Science, University of NSW, Sydney, NSW 2052, Australia (H.K.P.)
| | - Binod Rayamajhee
- School of Optometry and Vision Science, University of NSW, Sydney, NSW 2052, Australia (H.K.P.)
| | - Tasbiha Zahid
- Primary & Secondary Healthcare Department, Punjab 54000, Pakistan; (M.I.)
| | | | - Nicole A. Carnt
- School of Optometry and Vision Science, University of NSW, Sydney, NSW 2052, Australia (H.K.P.)
- Centre for Vision Research, Westmead Institute for Medical Research, Sydney, NSW 2145, Australia
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Rayamajhee B, Willcox M, Henriquez FL, Vijay AK, Petsoglou C, Shrestha GS, Peguda HK, Carnt N. The role of naturally acquired intracellular Pseudomonas aeruginosa in the development of Acanthamoeba keratitis in an animal model. PLoS Negl Trop Dis 2024; 18:e0011878. [PMID: 38166139 PMCID: PMC10795995 DOI: 10.1371/journal.pntd.0011878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 01/18/2024] [Accepted: 12/21/2023] [Indexed: 01/04/2024] Open
Abstract
BACKGROUND Acanthamoeba is an environmental host for various microorganisms. Acanthamoeba is also becoming an increasingly important pathogen as a cause of keratitis. In Acanthamoeba keratitis (AK), coinfections involving pathogenic bacteria have been reported, potentially attributed to the carriage of microbes by Acanthamoeba. This study assessed the presence of intracellular bacteria in Acanthamoeba species recovered from domestic tap water and corneas of two different AK patients and examined the impact of naturally occurring intracellular bacteria within Acanthamoeba on the severity of corneal infections in rats. METHODOLOGY/PRINCIPAL FINDINGS Household water and corneal swabs were collected from AK patients. Acanthamoeba strains and genotypes were confirmed by sequencing. Acanthamoeba isolates were assessed for the presence of intracellular bacteria using sequencing, fluorescence in situ hybridization (FISH), and electron microscopy. The viability of the bacteria in Acanthamoeba was assessed by labelling with alkyne-functionalized D-alanine (alkDala). Primary human macrophages were used to compare the intracellular survival and replication of the endosymbiotic Pseudomonas aeruginosa and a wild type strain. Eyes of rats were challenged intrastromally with Acanthamoeba containing or devoid of P. aeruginosa and evaluated for the clinical response. Domestic water and corneal swabs were positive for Acanthamoeba. Both strains belonged to genotype T4F. One of the Acanthamoeba isolates harboured P. aeruginosa which was seen throughout the Acanthamoeba's cytoplasm. It was metabolically active and could be seen undergoing binary fission. This motile strain was able to replicate in macrophage to a greater degree than strain PAO1 (p<0.05). Inoculation of Acanthamoeba containing the intracellular P. aeruginosa in rats eyes resulted in a severe keratitis with increased neutrophil response. Acanthamoeba alone induced milder keratitis. CONCLUSIONS/SIGNIFICANCE Our findings indicate the presence of live intracellular bacteria in Acanthamoeba can increase the severity of acute keratitis in vivo. As P. aeruginosa is a common cause of keratitis, this may indicate the potential for these intracellular bacteria in Acanthamoeba to lead to severe polymicrobial keratitis.
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Affiliation(s)
- Binod Rayamajhee
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
| | - Mark Willcox
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
| | - Fiona L. Henriquez
- School of Health and Life Sciences, University of the West of Scotland, Blantyre, Scotland, United Kingdom
| | - Ajay Kumar Vijay
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
| | - Constantinos Petsoglou
- Sydney and Sydney Eye Hospital, Southeastern Sydney Local Health District, Sydney, Australia
- Save Sight Institute, University of Sydney, Sydney, Australia
| | - Gauri Shankar Shrestha
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
| | - Hari Kumar Peguda
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
| | - Nicole Carnt
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW, Sydney, Australia
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Matsuo T, Nose M. A simple method for culturing Acanthamoeba from soft contact lens at a clinical laboratory of a hospital: Case report of Acanthamoeba keratitis. Clin Case Rep 2023; 11:e8248. [PMID: 38028087 PMCID: PMC10661332 DOI: 10.1002/ccr3.8248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 10/24/2023] [Accepted: 10/27/2023] [Indexed: 12/01/2023] Open
Abstract
Key Clinical Message A simple culturing method for Acanthamoeba available at a clinical laboratory is a key for making timely diagnosis and starting treatment with topical 0.02% chlorhexidine gluconate eye drops, together with 0.1% miconazole or fluconazole eye drops. Abstract A 19-year-old woman with pain and injection in the right eye showed spotty corneal infiltration and radiating linear opacity. Suspicious of Acanthamoeba keratitis, corneal scraping, and the soft contact lens were sent to in-house clinical laboratory to culture successfully Acanthamoeba on Sabouraud dextrose agar plate painted with heat-treated dead bacilli.
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Affiliation(s)
- Toshihiko Matsuo
- Graduate School of Interdisciplinary Science and Engineering in Health SystemsOkayama UniversityOkayama CityJapan
- Department of OphthalmologyOkayama University HospitalOkayama CityJapan
| | - Motoko Nose
- Department of Clinical LaboratoryOkayama University HospitalOkayama CityJapan
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Connelly L, Anijeet D, Tole D, Alexander CL. Acanthamoeba keratitis: Molecular typing of Acanthamoeba species directly from ocular tissue. CURRENT RESEARCH IN PARASITOLOGY & VECTOR-BORNE DISEASES 2023; 4:100141. [PMID: 37680763 PMCID: PMC10480524 DOI: 10.1016/j.crpvbd.2023.100141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 08/11/2023] [Accepted: 08/22/2023] [Indexed: 09/09/2023]
Abstract
This report explores the molecular profiling of Acanthamoeba spp. from individuals in the UK suffering from a debilitating, sight-threatening disease of the cornea known as Acanthamoeba keratitis (AK). Seventy ocular samples from individuals undergoing investigations for AK were sent to the Scottish Microbiology Reference Laboratories (SMiRL), Glasgow during 2017-2019, and subjected to DNA extraction followed by in-depth molecular typing using a nested PCR/bi-directional sequencing approach. Of the 70 samples tested, 40 were PCR-positive. Of these, 32 were successfully sequenced and assigned to two of 23 existing genotypes termed T1 to T23. Molecular profiling of the 32 samples highlighted two genotypes, namely T3 (n = 3) and T4 (n = 29). For those 29 samples identified as the T4 genotype, a sub-genotype (T4A-T4H) was recorded: T4A (n = 18); T4B (n = 5); T4C (n = 1); T4E (n = 4); and T4F (n = 1). This study highlights that the T4 genotype and T4A subtype are the predominant molecular variants to cause ocular disease in the UK. Gaining in-depth information on the molecular profiling of Acanthamoeba spp. is essential to increase our understanding of the source(s) of infection, transmission pathways, and potential associations with clinical outcomes for this rare, yet potentially debilitating ocular disease.
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Affiliation(s)
- Lisa Connelly
- Scottish Microbiology Reference Laboratories, Glasgow (SMiRL), Glasgow, UK
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Ledbetter EC, Dong L. Susceptibility of the Intact and Traumatized Feline Cornea to In Vitro Binding and Invasion by Acanthamoeba castellanii. Cornea 2023; 42:624-629. [PMID: 36518074 PMCID: PMC10060048 DOI: 10.1097/ico.0000000000003220] [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: 10/04/2022] [Revised: 11/02/2022] [Accepted: 11/16/2022] [Indexed: 12/23/2022]
Abstract
PURPOSE Acanthamoeba castellanii ( A. castellanii ) displays host specificity at the level of the ocular surface. This study determined the susceptibility of the intact and traumatized feline cornea to A. castellanii binding and invasion relative to other host species with established susceptibility and resistance to Acanthamoeba binding. METHODS Full-thickness buttons of fresh feline, porcine, and canine corneas were prepared. The corneal epithelium was confirmed intact by fluorescein staining or lightly scarified with a 25-G needle to simulate corneal trauma. Acanthamoeba castellanii was axenically cultivated. Corneal buttons were incubated with the parasite suspension or parasite-free medium for 18 hours at 35°C. Corneal buttons were rinsed, fixed, and processed for histopathology and immunohistochemistry using immunoperoxidase and immunofluorescence methods of amoeba detection. RESULTS Numerous amoebae were bound to feline and porcine corneas incubated with parasites. In both intact and traumatized corneas, amoebae were detected at all levels in the corneal epithelium and within the anterior stroma. In traumatized corneal sections, amoebae were frequently present in regions of epithelial damage. Corneal architecture was well-preserved in sections incubated with parasite-free medium; however, epithelial cell sloughing, separation of epithelial layers, and epithelial detachment from the stroma were observed in corneas incubated with amoebae. Intact and traumatized canine corneas were relatively free of adherent amoebae, and corneal architecture was indistinguishable between sections incubated with the parasite suspension and parasite-free medium. CONCLUSIONS The feline cornea is highly susceptible to in vitro binding and invasion by A. castellanii . Acanthamoeba binding to the feline cornea does not require a previous epithelial defect.
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Affiliation(s)
- Eric C. Ledbetter
- Departments of Clinical Sciences; and Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY
| | - Longying Dong
- Departments of Clinical Sciences; and Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY
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Campolo A, Patterson B, Lara E, Shannon P, Crary M. Complete Recovery of Acanthamoeba Motility among Surviving Organisms after Contact Lens Care Disinfection. Microorganisms 2023; 11:microorganisms11020299. [PMID: 36838263 PMCID: PMC9965617 DOI: 10.3390/microorganisms11020299] [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: 12/21/2022] [Revised: 01/05/2023] [Accepted: 01/21/2023] [Indexed: 01/26/2023] Open
Abstract
Acanthamoeba keratitis is a sight-threatening infection of the cornea which is extremely challenging to treat. Understanding this organism's responses during contact lens contact and disinfection could enhance our understanding of how Acanthamoebae colonize contact lens cases, better inform us on contact lens care solution (CLC) efficacy, and help us better understand the efficacy required of CLC products. To explore this gap in knowledge, we used Acanthamoeba ATCC 30461 and ATCC 50370 trophozoites to examine Acanthamoeba behavior during and after CLC disinfection. Amoebae were added to sterile aluminum flow cells and flow cell solutions were changed to Ringer's solution (control), or one of four CLCs based on biocides (PHMB, PAPB/Polyquad, Polyquad/Aldox, or Polyquad/Alexidine) for 6 h. Each flow cell solution was then changed to axenic culture media (AC6) for 12 h to determine the behavior of amoebae following disinfection. Distance, speed, and displacement were calculated for each organism. As compared to the control of one-quarter Ringer's solution, each CLC significantly impacted Acanthamoeba motility in both the CLC and AC6 conditions. However, the amoebae challenged with the PHMB CLC traveled a significantly greater total distance than with the other three CLCs, indicating differences in effectiveness between biocides. Furthermore, amoebae regaining motility post-disinfection by CLCs were observed to travel considerable distances and thus could be considered dangerous to ocular health. We determined that while all CLCs produced a substantial or complete cessation of movement vs. the control condition during disinfection, those which relied on the Polyquad biocides were the most effective, and that any amoebae which survived disinfection were able to recover motility. Future examinations of these findings should include direct correlations between motility and viability, and how infectivity and motility may be related.
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Carnt N, Minassian DC, Dart JKG. Acanthamoeba Keratitis Risk Factors for Daily Wear Contact Lens Users: A Case-Control Study. Ophthalmology 2023; 130:48-55. [PMID: 35952937 DOI: 10.1016/j.ophtha.2022.08.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 08/02/2022] [Accepted: 08/02/2022] [Indexed: 01/06/2023] Open
Abstract
PURPOSE This study was designed to establish risk factors for the development of Acanthamoeba keratitis (AK) for daily disposable (DD) contact lens (CL) users compared with daily wear (DW) reusable lens users and for risks unique to DD users. This is important because, in many major economies, CL use is the principal cause of microbial keratitis, of which AK accounts for approximately 50% of cases with sight loss. Determining these AK risks informs practitioner advice and consumer behavior. DESIGN Case-control study. PARTICIPANTS Cases and controls were recruited from an Accident and Emergency Department serving South-East England. Cases were new CL users with AK recruited retrospectively from January 2011 to February 2013 and prospectively thereafter until August 2014. Controls were recruited prospectively from February 2014 to June 2015. METHODS Analysis of a self-administered questionnaire. MAIN OUTCOME MEASURES Independent risk factors and population attributable risk percentage (PAR%) for AK. RESULTS A total of 83 AK cases and 122 controls were recruited; DD use was reported by 20 (24%) cases and 66 (54%) controls. In multivariable analyses adjusted for potential confounders, the odds of AK was higher for DW reusable soft lenses (odds ratio [OR], 3.84; 95% confidence interval [CI], 1.75-8.43) and rigid lenses (OR, 4.56; 95% CI, 1.03-20.19) than for DD lenses. Within the DD-using subset, AK was associated with the following modifiable risk factors: less frequent professional follow-up visits (OR, 10.12; 95% CI, 5.01-20.46); showering in lenses (OR, 3.29, 95% CI, 1.17-9.23); lens reuse (OR, 5.41; 95% CI, 1.55-18.89); and overnight wear (OR, 3.93; 95% CI, 1.15-13.46). The PAR% estimated that 30% to 62% of cases could be prevented by switching from reusable soft lens to DD lens use. CONCLUSIONS Acanthamoeba keratitis risks are increased > threefold in DW reusable lens users versus DD lens use. Acanthamoeba keratitis risks for DD lens users can be minimized by adherence to safe use guidelines (no reuse, overnight wear, or contamination by water). Safe CL use can be improved by increasing the prominence of risk avoidance information from manufacturers and regulators. Because AK accounts for half of severe keratitis in CL users, these measures can be expected to have public health benefits.
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Affiliation(s)
- Nicole Carnt
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia; Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom; National Institute of Health Research Moorfields Biomedical Research Centre, London, United Kingdom
| | | | - John K G Dart
- Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom; National Institute of Health Research Moorfields Biomedical Research Centre, London, United Kingdom.
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Fakae LB, Harun MS, Ting DSJ, Dua HS, Cave GW, Zhu XQ, Stevenson CW, Elsheikha HM. Camellia sinensis solvent extract, epigallocatechin gallate and caffeine confer trophocidal and cysticidal effects against Acanthamoeba castellanii. Acta Trop 2023; 237:106729. [DOI: 10.1016/j.actatropica.2022.106729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Revised: 10/19/2022] [Accepted: 10/19/2022] [Indexed: 11/19/2022]
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Campolo A, Pifer R, Walters R, Thomas M, Miller E, Harris V, King J, Rice CA, Shannon P, Patterson B, Crary M. Acanthamoeba spp. aggregate and encyst on contact lens material increasing resistance to disinfection. Front Microbiol 2022; 13:1089092. [PMID: 36601401 PMCID: PMC9806144 DOI: 10.3389/fmicb.2022.1089092] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 11/28/2022] [Indexed: 12/23/2022] Open
Abstract
Introduction Acanthamoeba keratitis is often caused when Acanthamoeba contaminate contact lenses and infect the cornea. Acanthamoeba is pervasive in the environment as a motile, foraging trophozoite or biocide-resistant and persistent cyst. As contact lens contamination is a potential first step in infection, we studied Acanthamoeba's behavior and interactions on different contact lens materials. We hypothesized that contact lenses may induce aggregation, which is a precursor to encystment, and that aggregated encystment would be more difficult to disinfect than motile trophozoites. Methods Six clinically and/or scientifically relevant strains of Acanthamoeba (ATCC 30010, ATCC 30461, ATCC 50370, ATCC 50702, ATCC 50703, and ATCC PRA-115) were investigated on seven different common silicone hydrogel contact lenses, and a no-lens control, for aggregation and encystment for 72 h. Cell count and size were used to determine aggregation, and fluorescent staining was used to understand encystment. RNA seq was performed to describe the genome of Acanthamoeba which was individually motile or aggregated on different lens materials. Disinfection efficacy using three common multi-purpose solutions was calculated to describe the potential disinfection resistance of trophozoites, individual cysts, or spheroids. Results Acanthamoeba trophozoites of all strains examined demonstrated significantly more aggregation on specific contact lens materials than others, or the no-lens control. Fluorescent staining demonstrated encystment in as little as 4 hours on contact lens materials, which is substantially faster than previously reported in natural or laboratory settings. Gene expression profiles corroborated encystment, with significantly differentially expressed pathways involving actin arrangement and membrane complexes. High disinfection resistance of cysts and spheroids with multi-purpose solutions was observed. Discussion Aggregation/encystment is a protective mechanism which may enable Acanthamoeba to be more disinfection resistant than individual trophozoites. This study demonstrates that some contact lens materials promote Acanthamoeba aggregation and encystment, and Acanthamoeba spheroids obstruct multi-purpose solutions from disinfecting Acanthamoeba.
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Affiliation(s)
| | - Reed Pifer
- Alcon Research, LLC, Fort Worth, TX, United States
| | | | - Megan Thomas
- Alcon Research, LLC, Fort Worth, TX, United States
| | - Elise Miller
- Alcon Research, LLC, Fort Worth, TX, United States
| | | | - Jamie King
- Alcon Research, LLC, Fort Worth, TX, United States
| | - Christopher A. Rice
- Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, IN, United States,Purdue Institute for Drug Discovery (PIDD), Purdue University, West Lafayette, IN, United States,Purdue Institute of Inflammation, Immunology and Infectious Disease (PI4D), Purdue University, West Lafayette, IN, United States
| | - Paul Shannon
- Alcon Research, LLC, Fort Worth, TX, United States
| | | | - Monica Crary
- Alcon Research, LLC, Fort Worth, TX, United States,*Correspondence: Monica Crary,
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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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12
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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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13
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Cardona G, Alonso S, Yela S. Compliance versus Risk Awareness with Contact Lens Storage Case Hygiene and Replacement. Optom Vis Sci 2022; 99:449-454. [PMID: 35165235 DOI: 10.1097/opx.0000000000001881] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
SIGNIFICANCE Compliance with hygiene and replacement of contact lens (CL) storage cases is key to avoid CL contamination and anterior ocular surface complications. However, compliance levels with these accessories remain low, even in patients with awareness of the risk associated with noncompliance. PURPOSE This study aimed to determine level of compliance with common practices regarding CL storage case hygiene and replacement, type of information provided by practitioners, and risk perception. METHODS An ad hoc self-reported survey was used to collect demographic and CL wear details, compliance with storage case care, type of received information, and risk perception (in a 1-to-5 scale). Inferential statistics explored the relationship of demographic details and type of received information with compliance and risk perception. RESULTS Nondaily disposable wearing participants returned 299 completed surveys, with a median age of 24 years (76.9% females). Monthly replacement silicone hydrogel CLs and multipurpose solutions were predominant. Self-reported compliance with storage case care was poor, with 19.1% of respondents never cleaning their cases, 68.6% exposing them to tap water, and 26.4% failing to replace them within 6 months of acquisition. Two-thirds of respondents received specific information on case maintenance, mainly in oral form. Perceived risk associated with poor-compliance practices was high (median values of 4 and 5), and increased with educational level (P = .02, regarding handwashing; P = .03, regarding case hygiene), with years of CL wear experience (P < .001, regarding handwashing), in those patients provided with specific information on CL case care (P = .01, regarding case replacement). CONCLUSIONS Compliance with CL storage case hygiene and replacement was generally poor, although awareness of risk associated with noncompliance was high and influenced by factors related to demographic details, CL experience, and patient-practitioner communication. Strategies must be explored to increase risk awareness through education because this may lead to better compliance practices.
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Affiliation(s)
| | - Silvia Alonso
- Department of Optics and Optometry, Universitat Politècnica de Catalunya, Terrassa, Spain
| | - Sandra Yela
- Department of Optics and Optometry, Universitat Politècnica de Catalunya, Terrassa, Spain
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14
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Roth M, Herrmann ME, Geerling G, Guthoff R. [Current and future effects of climate change on ophthalmology]. Ophthalmologe 2022; 119:552-560. [PMID: 35294593 DOI: 10.1007/s00347-022-01594-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/02/2022] [Indexed: 11/24/2022]
Abstract
BACKGROUND AND OBJECTIVES Climate change is also an increasingly important issue in the healthcare system. Due to its anatomical and physiological nature, the eye is directly exposed to environmental influences and changes in a special way. METHODS The current literature is used to illustrate the effects of climate-induced changes and the respective influences on the eye. A PubMed search (cut-off date 3 October 2021) using the search terms "climate change" or "planetary health" or "global health" and in each case "ophthalmology" or "eye" or "ocular" was used to determine the development of the number of publications between 2011 and 2021. RESULTS Measurable effects of climate change are already evident in a wide variety of ophthalmological fields. The significance of this topic, for instance, is reflected in a relatively constant increase in the number of publications and an almost tenfold increase in the number of publications per year from 2011 to 2021. CONCLUSION The impact of climate change on eye diseases and on the field of ophthalmology is multifaceted and could be expected to intensify in the coming years. Therefore, the interrelationships need to be further investigated in future studies, preferably on a large scale.
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Affiliation(s)
- M Roth
- Universitätsaugenklinik Düsseldorf, Moorenstr. 5, 40225, Düsseldorf, Deutschland.
| | - M E Herrmann
- Universitätsaugenklinik Düsseldorf, Moorenstr. 5, 40225, Düsseldorf, Deutschland
| | - G Geerling
- Universitätsaugenklinik Düsseldorf, Moorenstr. 5, 40225, Düsseldorf, Deutschland
| | - R Guthoff
- Universitätsaugenklinik Düsseldorf, Moorenstr. 5, 40225, Düsseldorf, Deutschland
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15
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Carnt NA, Man REK, Fenwick EK, Lamoureux EL, Keay LJ. Impact of Acanthamoeba Keratitis on the Vision-Related Quality of Life of Contact Lens Wearers. Cornea 2022; 41:206-210. [PMID: 35037904 DOI: 10.1097/ico.0000000000002901] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 08/29/2021] [Indexed: 11/27/2022]
Abstract
PURPOSE The aim of this study was to determine the impact of Acanthamoeba keratitis (AK) caused by contact lens (CL) use on vision-related quality of life (VRQOL) and the sociodemographic factors and disease outcome associated with VRQOL. METHODS Sixty-one CL-associated AK cases and 59 asymptomatic CL wearers (mean age ±SD 39.4 ± 16.5 vs. 45.5 ± 15.2 yrs, P = 0.04) were recruited from Moorfields Eye Hospital and Institute for Optometry, London. AK cases were surveyed during active disease and were stratified into "poor" and "good" outcomes based on clinical features. VRQOL was measured using Rasch-transformed scores from the Emotional, Mobility, and Reading domains of the 32-item Impact of Visual Impairment questionnaire. AK cases were compared with controls and "poor" outcomes compared with "good" with multivariable linear regression. Multivariable linear regression models were also used to identify the sociodemographic factors and disease outcome associated with VRQOL. RESULTS AK was associated with significant and substantial reductions in all 3 evaluated domains of VRQOL (Reading -59.6%, Mobility -59.8%, and Emotional -66.2%) compared with controls, independent of sociodemographic factors. Patients with AK who experienced poor outcomes, those who were of British White race (compared with all other races) and female, had lower VRQOL scores across all domains. Patients with AK with lower incomes scored worse on Reading and Mobility domains, whereas those with lower education had poorer Emotional scores. CONCLUSIONS AK has a considerable detrimental impact on VRQOL. Clinicians should consider the importance of referring patients with AK for rehabilitative support and counseling as part of active disease management.
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Affiliation(s)
- Nicole A Carnt
- School of Optometry and Vision Science, Kensington UNSW, Sydney, Australia
- Institute of Ophthalmology, University College London, London, United Kingdom
| | - Ryan E K Man
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore ; and
- Duke-NUS Medical School, Singapore
| | - Eva K Fenwick
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore ; and
- Duke-NUS Medical School, Singapore
| | - Ecosse L Lamoureux
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore ; and
- Duke-NUS Medical School, Singapore
| | - Lisa J Keay
- School of Optometry and Vision Science, Kensington UNSW, Sydney, Australia
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16
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Steele KR, Wagner H, Lai N, Zimmerman AB. Gas-Permeable Contact Lenses and Water Exposure: Practices and Perceptions. Optom Vis Sci 2021; 98:258-265. [PMID: 33771955 DOI: 10.1097/opx.0000000000001660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
SIGNIFICANCE This study provides insight into the current recommendations, clinical behaviors, and risk assessments of eye care professionals on the topic of rigid contact lens exposure to tap water. This knowledge may motivate professional organizations to develop initiatives to educate eye care professionals on the dangers of contact lens exposure to water. PURPOSE The purpose of this study was to investigate the practice patterns and risk perceptions of eye care professionals regarding gas-permeable contact lens exposure to tap water. METHODS A branched-logic survey was started by 320 clinicians, vision scientists, and industry personnel and was fully completed by 272 participants. The survey queried participants about their current practices, recommendations, and perceptions of risk regarding exposure of gas-permeable contact lenses to tap water. RESULTS Of those who prescribe gas-permeable contact lenses, 57.4% reported rinsing lenses with tap water, whereas only 32.7% reported engaging in this same behavior in front of patients. Of those who reported never rinsing lenses with tap water, 85.6% indicated that rinsing lenses with water increases infection risk, whereas 52.1% of those who rinse lenses with water reported the same perceived risk (P < .001). Of all participants, 60% indicated that wearing contact lenses while showering increases infection risk, and 50.2% of all participants advised patients to avoid this behavior. CONCLUSIONS A discrepancy exists between perceptions of risk concerning exposure of contact lenses to water and both clinical practices and patient education provided by professionals.
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Affiliation(s)
| | - Heidi Wagner
- The Ohio State University, College of Optometry, Columbus, Ohio
| | - Nicky Lai
- The Ohio State University, College of Optometry, Columbus, Ohio
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17
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Szczotka-Flynn LB, Shovlin JP, Schnider CM, Caffery BE, Alfonso EC, Carnt NA, Chalmers RL, Collier S, Jacobs DS, Joslin CE, Kroken AR, Lakkis C, Pearlman E, Schein OD, Stapleton F, Tu E, Willcox MDP. American Academy of Optometry Microbial Keratitis Think Tank. Optom Vis Sci 2021; 98:182-198. [PMID: 33771951 PMCID: PMC8075116 DOI: 10.1097/opx.0000000000001664] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
SIGNIFICANCE Think Tank 2019 affirmed that the rate of infection associated with contact lenses has not changed in several decades. Also, there is a trend toward more serious infections associated with Acanthamoeba and fungi. The growing use of contact lenses in children demands our attention with surveillance and case-control studies. PURPOSE The American Academy of Optometry (AAO) gathered researchers and key opinion leaders from around the world to discuss contact lens-associated microbial keratitis at the 2019 AAO Annual Meeting. METHODS Experts presented within four sessions. Session 1 covered the epidemiology of microbial keratitis, pathogenesis of Pseudomonas aeruginosa, and the role of lens care systems and storage cases in corneal disease. Session 2 covered nonbacterial forms of keratitis in contact lens wearers. Session 3 covered future needs, challenges, and research questions in relation to microbial keratitis in youth and myopia control, microbiome, antimicrobial surfaces, and genetic susceptibility. Session 4 covered compliance and communication imperatives. RESULTS The absolute rate of microbial keratitis has remained very consistent for three decades despite new technologies, and extended wear significantly increases the risk. Improved oxygen delivery afforded by silicone hydrogel lenses has not impacted the rates, and although the introduction of daily disposable lenses has minimized the risk of severe disease, there is no consistent evidence that they have altered the overall rate of microbial keratitis. Overnight orthokeratology lenses may increase the risk of microbial keratitis, especially secondary to Acanthamoeba, in children. Compliance remains a concern and a significant risk factor for disease. New insights into host microbiome and genetic susceptibility may uncover new theories. More studies such as case-control designs suited for rare diseases and registries are needed. CONCLUSIONS The first annual AAO Think Tank acknowledged that the risk of microbial keratitis has not decreased over decades, despite innovation. Important questions and research directions remain.
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Affiliation(s)
| | | | | | | | - Eduardo C Alfonso
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida
| | - Nicole A Carnt
- School of Optometry and Vision Science, University of New South Wales, Sydney, New South Wales, Australia
| | | | - Sarah Collier
- U.S. Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Deborah S Jacobs
- Massachusetts Eye and Ear, Cornea Service, Harvard Medical School, Boston, Massachusetts
| | - Charlotte E Joslin
- Department of Ophthalmology and Visual Science, College of Medicine, Division of Epidemiology and Biostatistics, School of Public Health, University of Illinois at Chicago, Chicago, Illinois
| | - Abby R Kroken
- School of Optometry, University of California, Berkeley, Berkeley, California
| | | | - Eric Pearlman
- Departments of Ophthalmology, and Physiology and Biophysics, University of California, Irvine, Irvine, California
| | - Oliver D Schein
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Fiona Stapleton
- School of Optometry and Vision Science, University of New South Wales, Sydney, New South Wales, Australia
| | - Elmer Tu
- University of Illinois Eye and Ear Infirmary, Chicago, Illinois
| | - Mark D P Willcox
- School of Optometry and Vision Science, University of New South Wales, Sydney, New South Wales, Australia
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18
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Carnt NA, Subedi D, Lim AW, Lee R, Mistry P, Badenoch PR, Kilvington S, Dutta D. Prevalence and seasonal variation of Acanthamoeba in domestic tap water in greater Sydney, Australia. Clin Exp Optom 2020; 103:782-786. [PMID: 32227362 DOI: 10.1111/cxo.13065] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 11/17/2019] [Accepted: 02/28/2020] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND This study examined the prevalence of free-living Acanthamoeba in domestic tap water in the greater Sydney region, Australia, and determined any seasonal variation in prevalence. METHODS Fifty-four participants were included in this study following approval from an institutional human research ethics committee. Each participant self-collected two samples (one in summer and another in winter) from the surface of the drain of the bathroom sink using an instructional kit. The samples were cultured by inoculating onto a non-nutrient agar plate seeded with Escherichia coli and incubation at 32°C for two weeks. The plates were microscopically examined for the presence of free-living amoeba. DNA was isolated from 20 samples and a polymerase chain reaction (PCR) assay was performed for amplification of the partial sequence of the 18S ribosomal RNA gene. The PCR amplified products were sequenced using Sanger sequencing and genotyping was performed based on the variation in nucleotide sequences. RESULTS A total of 97 samples were collected over the two collection periods, with 28.6 per cent of samples morphologically classified as Acanthamoeba. The summer period yielded 16 of 54 (29.6 per cent) samples classified as Acanthamoeba, while the winter period yielded 12 of 43 (27.9 per cent) samples classified as Acanthamoeba. There was no statistically significant difference (p = 0.85) between the prevalence of free-living Acanthamoeba in summer compared to winter. Phylogenetic analysis showed that 15 of 20 (75 per cent) isolates belonged to genotype T4, the most frequent genotype isolated in Acanthamoeba keratitis. CONCLUSION The prevalence of free-living Acanthamoeba characterised morphologically in domestic tap water of the greater Sydney region was higher than expected, especially considering the low incidence of Acanthamoeba keratitis in Australia. However, this study did not find variation between seasons. As the T4 genotype was most common, Sydney-based practitioners must always consider Acanthamoeba as a possible causative organism in cases of microbial keratitis, regardless of the season.
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Affiliation(s)
- Nicole A Carnt
- School of Optometry and Vision Science, The University of New South Wales, Sydney, Australia.,Centre for Vision Research, Westmead Institute for Medical Research, The University of Sydney, Sydney, Australia.,Institute of Ophthalmology, University College London, London, UK
| | - Dinesh Subedi
- School of Optometry and Vision Science, The University of New South Wales, Sydney, Australia
| | - Ann W Lim
- School of Optometry and Vision Science, The University of New South Wales, Sydney, Australia
| | - Rebecca Lee
- School of Optometry and Vision Science, The University of New South Wales, Sydney, Australia
| | - Priyal Mistry
- School of Optometry and Vision Science, The University of New South Wales, Sydney, Australia
| | - Paul R Badenoch
- Department of Ophthalmology, Flinders Medical Centre, Adelaide, Australia.,College of Medicine and Public Health, Flinders University, Adelaide, Australia
| | - Simon Kilvington
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, UK
| | - Debarun Dutta
- School of Optometry and Vision Science, The University of New South Wales, Sydney, Australia.,Optometry and Vision Science, Life and Health Sciences, Aston University, Birmingham, UK
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