title: Detection of Acanthamoeba on the ocular surface in a Spanish population using the Schirmer strip test: pathogenic potential, molecular classification and evaluation of the sensitivity to chlorhexidine and voriconazole of the isolated Acanthamoeba strains.
abstract: Pathogenic strains of Acanthamoeba are causative agents of a sight-threatening infection of the cornea known as Acanthamoeba keratitis, which is often associated with the misuse of contact lenses. However, there is still a question remaining to be answered, which is whether these micro-organisms are present on the ocular surface of healthy individuals. Therefore, the aim of this study was to determine the presence of Acanthamoeba on the ocular surface in healthy patients and also in those with other ocular surface infections. Sterile Schirmer test strips were used to collect samples from a group of patients who attended an ophthalmology consultation at the Hospital del Norte, Icod de los Vinos, Tenerife, Canary Islands. Most of the patients (46 individuals, 79.31  %) presented ocular surface pathologies such as blepharitis or conjunctivitis; the rest did not present any pathology. None of the patients included in the study wore contact lenses. The collected samples were cultured in 2  % non-nutrient agar plates and positive plates were then cultured in axenic conditions for further analyses. Molecular analysis classified all isolated strains as belonging to Acanthamoeba genotype tbl4, and osmotolerance and thermotolerance assays revealed that all strains were potentially pathogenic. Furthermore, all strains were assayed for sensitivity against voriconazole and chlorhexidine. Assays showed that both drugs were active against the tested strains. In conclusion, the Schirmer strip test is proposed as an effective tool for the detection of Acanthamoeba on the ocular surface.
authors: University Institute of Tropical Diseases and Public Health of the Canary Islands, University of La Laguna, Avda Astrofísico Fco. Sánchez, S/N, 38203 La Laguna, Tenerife, Canary Islands, Spain.|Department of Ophthalmology, Hospital Universitario de Canarias, Tenerife, Canary Islands, Spain.
authors: Pedro
authors: P
authors: Rocha-Cabrera
authors: University Institute of Tropical Diseases and Public Health of the Canary Islands, University of La Laguna, Avda Astrofísico Fco. Sánchez, S/N, 38203 La Laguna, Tenerife, Canary Islands, Spain.
authors: María
authors: M
authors: Reyes-Batlle
authors: University Institute of Tropical Diseases and Public Health of the Canary Islands, University of La Laguna, Avda Astrofísico Fco. Sánchez, S/N, 38203 La Laguna, Tenerife, Canary Islands, Spain.
authors: Carmen María
authors: CM
authors: Martín-Navarro
authors: University Institute of Tropical Diseases and Public Health of the Canary Islands, University of La Laguna, Avda Astrofísico Fco. Sánchez, S/N, 38203 La Laguna, Tenerife, Canary Islands, Spain.
authors: Alexis
authors: A
authors: Dorta-Gorrín
authors: University Institute of Tropical Diseases and Public Health of the Canary Islands, University of La Laguna, Avda Astrofísico Fco. Sánchez, S/N, 38203 La Laguna, Tenerife, Canary Islands, Spain.
authors: Atteneri
authors: A
authors: López-Arencibia
authors: University Institute of Tropical Diseases and Public Health of the Canary Islands, University of La Laguna, Avda Astrofísico Fco. Sánchez, S/N, 38203 La Laguna, Tenerife, Canary Islands, Spain.|Laboratoire Matériaux-Molécules et Applications, IPEST, B.P. 51 2070 La Marsa, University of Carthage, Tunisia.
authors: Ines
authors: I
authors: Sifaoui
authors: University Institute of Tropical Diseases and Public Health of the Canary Islands, University of La Laguna, Avda Astrofísico Fco. Sánchez, S/N, 38203 La Laguna, Tenerife, Canary Islands, Spain.
authors: Enrique
authors: E
authors: Martínez-Carretero
authors: University Institute of Tropical Diseases and Public Health of the Canary Islands, University of La Laguna, Avda Astrofísico Fco. Sánchez, S/N, 38203 La Laguna, Tenerife, Canary Islands, Spain.
authors: José E
authors: JE
authors: Piñero
authors: Department of Ophthalmology, Hospital Universitario de Canarias, Tenerife, Canary Islands, Spain.
authors: Fernando
authors: F
authors: Martín-Barrera
authors: University Institute of Tropical Diseases and Public Health of the Canary Islands, University of La Laguna, Avda Astrofísico Fco. Sánchez, S/N, 38203 La Laguna, Tenerife, Canary Islands, Spain.
authors: Basilio
authors: B
authors: Valladares
authors: University Institute of Tropical Diseases and Public Health of the Canary Islands, University of La Laguna, Avda Astrofísico Fco. Sánchez, S/N, 38203 La Laguna, Tenerife, Canary Islands, Spain.
authors: Jacob
authors: J
authors: Lorenzo-Morales
mesh_terms: D000048:Acanthamoeba / Q000145:classification* / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*; D000981:Antiprotozoal Agents / Q000494:pharmacology*; D002470:Cell Survival; D002710:Chlorhexidine / Q000494:pharmacology*; D016000:Cluster Analysis; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D005123:Eye / Q000382:microbiology*; D005260:Female; D005838:Genotype; D064368:Healthy Volunteers; D006358:Hot Temperature; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009997:Osmotic Pressure; D021261:Parasitic Sensitivity Tests; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D013030:Spain; D014774:Virulence; D065819:Voriconazole / Q000494:pharmacology*
chemical_list: D000981:Antiprotozoal Agents; D016054:DNA, Protozoan; D065819:Voriconazole; D002710:Chlorhexidine