title: Characterization of a human-pathogenic Acanthamoeba griffini isolated from a contact lens-wearing keratitis patient in Spain.
abstract: Amoebae were isolated from contact lenses of a symptomatic lens wearer in Spain. Protozoa were characterized by studying their morphology, biology, protease activity and the 18S rRNA gene sequence. Morphology of the organism was observed by light microscopy, scanning electron microscopy and transmission electron microscopy. Its structure corresponded to an amphizoic amoeba. The protozoa grew well at 37 °C and poorly at lower temperatures. In addition, it was capable of lysing mammalian cells in vitro. A major 56 kDa proteolytic enzyme was observed in amoeba crude extracts by gelatin-sodium dodecyl sulphate-polyacrylamide gel electrophoresis. Most proteolytic enzymes in protozoa extracts showed significant activity over a wide range of pH (3-9) and temperature (8-45 °C) values. The assays on inhibition of protease activity indicated strongly that enzymes detected in amoeba extracts corresponded to serine proteases and, to a lesser extent, cysteine proteases. The use of proteinase inhibitors on a tissue culture model proved that the proteinase activity is critical for developing focal lesions in HeLa cell monolayers. Finally, partial sequencing of the 18S ribosomal RNA gene and phylogenetic analyses indicated that the isolate is closely related to Acanthamoeba griffini H37 from the UK (T3 genotype).
authors: Departamento de Biomedicina y Biotecnología, Grupo ECOMYP, Facultad de Farmacia,Universidad de Alcalá,28871 Alcalá de Henares, Madrid,Spain.
authors: I
authors: I
authors: Heredero-Bermejo
authors: Departamento de Biomedicina y Biotecnología, Grupo ECOMYP, Facultad de Farmacia,Universidad de Alcalá,28871 Alcalá de Henares, Madrid,Spain.
authors: A
authors: A
authors: Criado-Fornelio
authors: Servicio de Parasitología,Centro Nacional de Microbiología, Instituto de Ciencias de la Salud Carlos III,Carretera Majadahonda-Pozuelo km 2, 28224 Majadahonda, Madrid,Spain.
authors: I
authors: I
authors: De Fuentes
authors: Departamento de Biomedicina y Biotecnología, Grupo ECOMYP, Facultad de Farmacia,Universidad de Alcalá,28871 Alcalá de Henares, Madrid,Spain.
authors: J
authors: J
authors: Soliveri
authors: Departamento de Biomedicina y Biotecnología, Grupo ECOMYP, Facultad de Farmacia,Universidad de Alcalá,28871 Alcalá de Henares, Madrid,Spain.
authors: J L
authors: JL
authors: Copa-Patiño
authors: Departamento de Biomedicina y Biotecnología, Grupo ECOMYP, Facultad de Farmacia,Universidad de Alcalá,28871 Alcalá de Henares, Madrid,Spain.
authors: J
authors: J
authors: Pérez-Serrano
mesh_terms: D000048:Acanthamoeba / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification* / Q000648:ultrastructure; D015823:Acanthamoeba Keratitis / Q000453:epidemiology / Q000469:parasitology*; D000562:Amebiasis / Q000453:epidemiology / Q000469:parasitology*; D003261:Contact Lenses / Q000009:adverse effects* / Q000469:parasitology*; D016054:DNA, Protozoan / Q000235:genetics; D005260:Female; D006801:Humans; D010447:Peptide Hydrolases / Q000235:genetics / Q000378:metabolism; D058974:Phylogeography; D011480:Protease Inhibitors; D016053:RNA, Protozoan / Q000235:genetics; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D013030:Spain / Q000453:epidemiology
chemical_list: D016054:DNA, Protozoan; D011480:Protease Inhibitors; D016053:RNA, Protozoan; D012337:RNA, Ribosomal, 18S; D010447:Peptide Hydrolases
keywords: keratitis