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Licensed Unlicensed Requires Authentication Published by De Gruyter April 13, 2018

Virulent T4 Acanthamoeba causing keratitis in a patient after swimming while wearing contact lenses in Southern Brazil

Laura Fuhrich Fabres, Vinicius José Maschio, Denise Leal dos Santos, Sergio Kwitko, Diane Ruschel Marinho, Bruno Schneider de Araújo, Claudete Inês Locatelli and Marilise Brittes Rott
From the journal Acta Parasitologica


Several strains of free-living amoebae belonging to the genus Acanthamoeba can cause a painful sight-threatening disease of the cornea known as Acanthamoeba keratitis (AK). The numbers of AK cases keep rising worldwide mainly due to an increase in contact lens wearers and lack of hygiene in the maintenance of contact lenses and their cases. We report a case of AK in a healthy young woman admitted to the Hospital de Clinicas in Porto Alegre, southern Brazil. Corneal scrapings were examined for the presence of Acanthamoeba strains. The initial isolate was characterized by morphological and genotypic properties. The isolate belonged to group III according to Pussard and Pons’ cyst morphology. Analysis of its 18S rDNA sequence identified the isolate as genotype T4. The T4 genotype is the most commonly reported among keratitis isolates and the most common in environmental samples.


The authors thank the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) for the financial support, the Fundo de Incentivo à Pesquisa e Eventos (FIPE/HCPA), and the Department of Microbiology, Immunology and Parasitology of the Universidade Federal do Rio Grande do Sul, Brazil.


Arance-Gil A., Gutiérrez-Ortega AR., Villa-Collar C., Nieto-Bona A., Lopes-Ferreira D., Gonzálvez-Méijome J.M. 2014. Corneal cross-linking for Acanthamoeba keratitis in an orthokeratology patient after swimming in contaminated water. Cont Lens Anterior Eye. 37: 224–7. 10.1016/j.clae.2013.11.008Search in Google Scholar

Booton G.C., Rogerson A., Bonilla T.D., Seal D.V., Kelly D.J., Beattie T.K., et al. 2004. Molecular and physiological evaluation of subtropical environmental isolates of Acanthamoeba spp., causal agent of Acanthamoeba keratitis. Journal of Eukaryotic Microbiology, 51, 192–200. 10.1111/j.1550-7408.2004.tb00545.xSearch in Google Scholar

Booton G.C., Visvesvara G.S., Byers T.J., Kelly D.J., Fuerst P.A. 2005. Identification and Distribution of Acanthamoeba Species Genotypes Associated with nonkeratitis Infections. Journal of Clinical Microbiology, 43, 1689–1693. 10.1128/JCM.43.4.1689-1693.2005Search in Google Scholar PubMed

Choo J, Vuu K, Bergenske P, Burnham K, Smythe J, Caroline P. 2005. Bacterial populations on silicone hydrogel and hydrogel contact lenses after swimming in a chlorinated pool. Optometry and Vision Science. 82:134–710.1097/01.OPX.0000153168.54495.DASearch in Google Scholar

Corsaro D, Venditti D. 2010. Phylogenetic evidence for a new genotype of Acanthamoeba (Amoebozoa Acanthamoebida). Parasitology Research, 7, 233–8. 10.1007/s00436-010-1870-6Search in Google Scholar

Corsaro D., Walochnik J., Köhsler M., Rott M.B. 2015. Acanthamoeba misidentification and multiple labels: redefining genotypes T16, T19, and T20 and proposal for Acanthamoeba micheli sp. nov. (genotype T19). Parasitology Research, 114, 2481–2490. 10.1007/s00436-015-4445-8Search in Google Scholar PubMed

De Jonckheere J. 1987. Taxonomy. Amphizoic amoebae. In: Rondanelli EG (ed) Human pathology. Infectious diseases color atlas monographs. Piccin Nuova Libraria, Padua, pp 25–48Search in Google Scholar

Duarte J.L., Furst C., Klisiewicz D.R., Klassen G., Costa A.O. 2013. Morphological, genotypic, and physiological characterization of Acanthamoeba isolates from keratitis patients and the domestic environment in Vitoria, Espírito Santo, Brazil. Experimental Parasitology. 135, 9–14. 10.1016/j.exppara.2013.05.013Search in Google Scholar

Gast R.J. 2001. Development of an Acanthamoeba-specific reverses dot-blot and the discovery of a new ribotype. Journal of Eukaryotic Microbiology, 48, 609–15. 10.1111/j.1550-7408.2001.tb00199.xSearch in Google Scholar

Gupta R., Gorski M., Henderson T., Lazzaro D., Haseeb M.A. 2015. Clinical Course of Unilateral Acanthamoeba Keratitis in a Cosmetic Contact Lens Wearer. Annals of Clinical & Laboratory Science 45, 366–370Search in Google Scholar

Hewett M.K., Robinson B.S., Monis P.T., Saint C.P. 2003. Identification of a new Acanthamoeba 18S rRNA gene sequence type, corresponding to the species Acanthamoeba jacobsi Sawyer. Acta Protozoologica, 42, 325–9Search in Google Scholar

Hirst L.W., Green W.R., Merz W., Kaufmann C., Visvesvara G.S., Jensen A., Howard M. 1984. Management of Acanthamoeba keratitis. A case report and review of the literature. Ophthalmology. 91, 1105–1111. in Google Scholar PubMed

Horn M., Fritsche T.R., Gautom R.K., Schleifer K.H., Wagner M. 1999. Novel bacterial endosymbionts of Acanthamoeba spp. related to the Paramecium caudatum symbiont Caedibacter caryophilus. Environmental Microbiology, 1, 357–67. 10.1046/j.1462-2920.1999.00045.xSearch in Google Scholar PubMed

Hsieh W.C., Dornic D.E. 1989. Acanthamoeba dendriform keratitis. Journal of the American Optometric Association, 60, 32–4Search in Google Scholar PubMed

Khan N.A. 2006. Acanthamoeba: Biology and increasing importance in human health. FEMS Microbiological Reviews, 30, 564–595. 10.1111/j.1574-6976.2006.00023.xSearch in Google Scholar

Kobayashi T., Gibbon L., Mito T., Shiraishi A., Uno T., Ohashi Y. 2011. Efficacy of commercial soft contact lens disinfectant solutions against Acanthamoeba. Japanese Journal of Ophthalmology, 55, 547–57.10.1007/s10384-011-0062-ySearch in Google Scholar PubMed

Lorenzo-Morales J., Martín-Navarro C.M., López-Arencibia A., Arnalich-Montiel F., Piñero J.E., Valladares B. 2013. Acanthamoeba keratitis: an emerging disease gathering importance worldwide? Trends in Parasitology, 29, 181–187. 10.1016/ in Google Scholar PubMed

Lorenzo-Morales J., Khan N.A., Walochnik J. 2015. An update on Acanthamoeba keratitis: diagnosis, pathogenesis and treatment. Parasite, 22, 10. 10.1051/parasite/2015010Search in Google Scholar PubMed

Magnet A, Henriques-Gil N, Galván-Diaz AL, Izquiedo F, Fenoy S, Del Aguila C (2014) Novel Acanthamoeba 18S rRNA gene sequence type from an envirionmental isolate. Parasitology Research, 113, 2845–2850. 10.1007/s00436-014-3945-2Search in Google Scholar

Marciano-Cabral F., Cabral G. 2003. Acanthamoeba spp. as agents of disease in humans. Clinical Microbiology Reviews, 16, 273–307. 10.1128/CMR.16.2.273-307. 2003Search in Google Scholar PubMed

Moore M.B., McCulley J.P., Luckenbach M., Gelender H., Newton C., McDonald MB., Visvesvara G.S. 1985. Acanthamoeba keratitis associated with soft contact lenses. American Journal of Ophthalmology, 100: 396–40310.1016/0002-9394(85)90500-8Search in Google Scholar PubMed

Mutoh T., Ishikawa I., Matsumoto Y., Chikuda M. 2010. A retrospective study of nine cases of Acanthamoeba keratitis. Clinical Ophthalmology, 4, 1189–1192. 10.2147/OPTH.S14202Search in Google Scholar

Naginton J., Watson P.G., Playfair T.J., Mc Gill J., Jones B.R., Steele A.D. 1974. Amoebicinfection of the eye. Lancet, 2:1537–4010.1016/S0140-6736(74)90285-2Search in Google Scholar PubMed

Nuprasert W., Putaporntip C., Pariyakanok L., Jongwutiwes S. 2010. Identification of a novel T17 genotype of Acanthamoeba from environmental isolates and T10 genotype causing keratitis in Thailand. Journal of Clinical Microbiology, 48, 4636–40. 10.1128/JCM.01090-10Search in Google Scholar PubMed PubMed Central

Omaña-Molina M., Vanzzini-Zago V., Hernandez-Martinez D., Gonzales-Robles A., Salazar-Villatoro L., Ramirez-Flores E., et al. 2016. Acanthamoeba genotypes T3 and T4 as causative agents of amoebic keratitis in Mexico. Parasitolology Research,15, 873–8. 10.1007/s00436-015-4821-4Search in Google Scholar PubMed

Page F.C. (Ed.) 1988. A new key to freshwater and soil Gymnamoebae. Freshwater Biological Association, Ambleside, pp 122Search in Google Scholar

Page M.A., Mathers W.D. 2013. Acanthamoeba keratitis: a 12-year experience covering a wide spectrum of presentations, diagnoses, and outcomes. Journal of Ophtalmology, 2013 670242 10.1155/2013/670242Search in Google Scholar PubMed PubMed Central

Pussard M., Pons R. 1977. Morphologie de la paroi kystique et taxonomie du genre Acanthamoeba (Protozoa, Amoebida). Protistologica, 8:57–59 (In Spanish)Search in Google Scholar

Qvarnstrom Y., Nerad T.A., Visvesvara G.S. 2013. Characterization of a new pathogenic Acanthamoeba Species, A. byersi n. sp., isolated from a human with fatal amoebic encephalitis. Journal of Eukaryotic Microbiology, 60, 626–633. 10.1111/jeu.12069Search in Google Scholar PubMed PubMed Central

Radford C.F., Lehmann O.J., Dart J.K. 1998. Acanthamoeba keratitis: multicenter survey in England 1992–6. National Acanthamoeba keratitis study group. British Journal of Ophthalmology, 82, 1387–9210.1136/bjo.82.12.1387Search in Google Scholar PubMed PubMed Central

Radford C.F., Minassian D.C., Dart J.K. 2002. Acanthamoeba keratitis in England and Wales: incidence, outcome, and risk factors. British Journal of Ophthalmology, 86:536–4210.1136/bjo.86.5.536Search in Google Scholar PubMed PubMed Central

Schroeder J.M., Booton G.C., Hay J., Niszl I.A., Seal D.V., Markus M.B., et al. 2001 Use of subgenic 18S ribosomal DNA PCR and sequencing for genus and genotype identification of Acanthamoebae from humans with keratitis and from sewage sludge. Journal of Clinical Microbiology, 39, 1903–1911. 10.1128/JCM.39.5.1903-1911.2001Search in Google Scholar PubMed PubMed Central

Siddiqui R., Chaudhry T., Lakhundi S., Ahmad K., Khan N.A. 2014. Failure of chemotherapy in the first reported cases of Acanthamoeba keratitis in Pakistan. Pathogens and Global Health, 108: 49–52. 10.1179/2047773213Y.0000000124Search in Google Scholar PubMed PubMed Central

Stothard D.R., Schroeder-Diedrich J.M., Awwad M.H., Gast R.J., Ledee D.R., Rodriguez-Zaragoza S. et al. 1998. The evolutionary history of the genus Acanthamoeba and the identification of eight new 18S rRNA gene sequence types. Journal Eukaryotic Microbiology, 45, 45–5410.1111/j.1550-7408.1998.tb05068.xSearch in Google Scholar PubMed PubMed Central

Vaddavalli P.K., Garg P., Sharma S., Rao G.N., Thomas R. 2011. Role of confocal microscopy in the diagnosis of fungal and Acanthamoeba keratitis. Ophthalmology. 118, 29–35. 10.1016/j.ophtha.2010.05.018Search in Google Scholar PubMed

Visvesvara G.S., Moura H., Schuster F.L. 2007. Pathogenic and opportunistic free-living amoebae: Acanthamoeba spp., Balamuthia mandrillaris, Naegleria fowleri, and Sappina diploidea. FEMS Immunology & Medical Microbiology, 50:1–26. 10.1111/j.1574-695X.2007.00232.xSearch in Google Scholar PubMed

Wilhelmus K.R., Jones D.B., Matoba A.Y., Hamill M.B., Pflugfelder S.C., Weikert M.P. 2008. Bilateral Acanthamoeba keratitis. American Journal of Ophthalmology, 145:193–197. 10.1016/j.ajo.2007.09.037Search in Google Scholar PubMed

Received: 2017-8-23
Revised: 2017-12-18
Accepted: 2018-1-9
Published Online: 2018-4-13
Published in Print: 2018-6-26

© 2018 W. Stefański Institute of Parasitology, PAS