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Sample records for inflamatoria por acanthamoeba

  1. Conjuntivite presumível por Acanthamoeba

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    Ruthes,Ana Cristina de Carvalho; Wahab,Sâmia; Wahab,Najua; Moreira,Hamilton; Moreira,Luciane

    2004-01-01

    OBJETIVO: Abordar quatro casos de conjuntivite presumível por Acanthamoeba, descrevendo o diagnóstico, considerando sinais e sintomas e o tratamento instituído. MÉTODOS: Foram estudados casos de conjuntivite presumível por Acanthamoeba diagnosticados no Hospital de Olhos do Paraná (HOP), no período de setembro/1998 a janeiro/2002. Todos os olhos estudados foram submetidos a um protocolo de investigação que incluía exame oftalmológico completo, microbiologia e cultura de secreções conjuntivais...

  2. Ceratite bilateral por Acanthamoeba: relato de caso Bilateral Acanthamoeba keratitis: case report

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    Wilson Nahmatallah Obeid

    2003-12-01

    Full Text Available A ceratite por Acanthamoeba é uma infecção ocular grave que, apesar dos recentes progressos no diagnóstico e tratamento, ainda provoca prolongada morbidade e perda da acuidade visual. Relatamos um caso de ceratite bilateral por Acanthamoeba em usuário de lentes de contato, que é o primeiro caso descrito na literatura brasileira.Acanthamoeba keratitis is a severe ocular infection which even with recent progress in diagnosis and treatment still causes long morbidity and loss of visual acuity. We describe a case of bilateral Acanthamoeba keratitis in a user of contact lenses, which is the first case discussed in Brazilian literature.

  3. Conjuntivite presumível por Acanthamoeba Conjunctivitis presumably due to Acanthamoeba

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    Ana Cristina de Carvalho Ruthes

    2004-12-01

    Full Text Available OBJETIVO: Abordar quatro casos de conjuntivite presumível por Acanthamoeba, descrevendo o diagnóstico, considerando sinais e sintomas e o tratamento instituído. MÉTODOS: Foram estudados casos de conjuntivite presumível por Acanthamoeba diagnosticados no Hospital de Olhos do Paraná (HOP, no período de setembro/1998 a janeiro/2002. Todos os olhos estudados foram submetidos a um protocolo de investigação que incluía exame oftalmológico completo, microbiologia e cultura de secreções conjuntivais. RESULTADOS: Os exames laboratoriais de microscopia e cultura do material colhido estes pacientes revelaram o diagnóstico de Acanthamoeba. A maioria dos pacientes referia olhos vermelhos e irritação ocular de longa data. Os autores encontraram correlação entre a cultura e o exame direto, em que se evidenciou a presença de cistos e trofozoítas do protozoário. CONCLUSÃO: Este é o primeiro relato de conjuntivite provavelmente por Acanthamoeba de acordo com a literatura revisada. Pacientes selecionados e refratários ao tratamento habitual de infecção ocular externa devem ser considerados para estudo laboratorial adequado à procura etiológica da doença.PURPOSE: To describe four cases of conjunctivitis presumably due to Acanthamoeba considering diagnosis, signs, symptoms and treatment. METHODS: We reviewed the medical records of all patients who presented a clinical diagnosis of Acanthamoeba conjunctivitis between September/1998 to January/2001 at the "Hospital de Olhos do Paraná (HOP". All eyes were submitted to a protocol of investigation that included ophthalmologic examination, microscopic examination and culture exams of conjunctival smears for adequate treatment. RESULTS: The laboratorial results of conjunctival smears revealed contamination with Acanthamoeba by direct examination and thereafter, confirmed by culture. The authors observed cysts and trophozoites of Acanthamoeba. CONCLUSION: This is the first report of

  4. Actividad inflamatoria en múltiples placas ateroscleróticas en pacientes fallecidos por infarto agudo de miocardio

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    Alejandro García Escudero

    2009-01-01

    Full Text Available IntroducciónEstudios clínicos y anatomopatológicos sugieren que los procesos inflamatorios tienen un papel importante en la inestabilidad de la placa aterosclerótica, dado que en pacientes con síndromes coronarios agudos se observan infiltrados inflamatorios difusos en las arterias coronarias.ObjetivosEvaluar y localizar la distribución de placas vulnerables e infiltrados inflamatorios en pacientes fallecidos por infarto agudo de miocardio.Material y métodosMediante microscopia óptica se estudiaron las arterias coronarias de 58 pacientes fallecidos por infarto de miocardio. En las arterias coronarias relacionadas con el infarto y en las no relacionadas se registraron las siguientes variables: presencia de trombo, rotura de placa, hemorragia intraplaca y presencia de infiltrado inflamatorio.ResultadosAl analizar las diferencias existentes entre las arterias responsables del infarto y en las no responsables se encontraron diferencias significativas con respecto a la presencia de trombo (69% versus 38%; p < 0,008 y de hemorragia intraplaca (69% versus 50%; p < 0,03. No se encontró una diferencia significativa entre la arteria responsable y la no responsable al evaluar la presencia de infiltrado inflamatorio en las placas ateroscleróticas (77% versus 71%; p = ns.ConclusiónEn el infarto agudo de miocardio se comprobó la presencia de actividad inflamatoria que afectaba a más de un vaso, con compromiso de otras arterias además de la responsable del infarto. Se detectó también accidente agudo de placa en más de una arteria coronaria.REV ARGENT CARDIOL 2009;77:81-87.

  5. Citologia de impressão no diagnóstico de infecção corneana por Acanthamoeba: relato de caso Diagnosis of Acanthamoeba corneal infection by impression cytology: case report

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    Jeison de Nadai Barros

    2007-03-01

    Full Text Available Relatamos três casos de infecção corneana por Acanthamoeba sp em que foi possível detectar cistos do microorganismo com a técnica de citologia de impressão. Três pacientes encaminhados ao Laboratório de Doenças Externas Oculares em 2004 com alterações superficiais da córnea foram submetidos ao exame de citologia de impressão para investigação da presença de cistos de Acanthamoeba sp. Duas amostras foram obtidas da córnea de cada paciente e coradas com PAS, hematoxilina e Papanicolaou. Investigação microbiológica de rotina e cultura também foram realizadas após raspado da córnea. O cultivo das amostras e a citologia de impressão foram positivas para Acanthamoeba sp em todos os pacientes, ao passo que os raspados corados com Giemsa foram positivos em dois casos. A citologia de impressão revelou cistos de Acanthamoeba sp entre feixe de células epiteliais corneanas e como células isoladas. Foram observados cistos no epitélio de um dos pacientes com a citologia de impressão após três meses de tratamento, enquanto o raspado foi negativo. No exame anatomopatológico observaram-se cistos no epitélio e estroma de uma córnea receptora de um dos pacientes após transplante. Neste estudo, a citologia de impressão detectou com sucesso cistos de Acanthamoeba sp em pacientes com acometimento epitelial. Por tratar-se de método não invasivo, a técnica pode ser usada para facilitar o diagnóstico mais precoce da infecção por Acanthamoeba, sendo útil também no acompanhamento do tratamento da doença.To describe three cases of corneal infection due to Acanthamoeba sp in which was possible to detect Acanthamoeba sp cysts by the corneal impression cytology technique. Three patients referred to the External Eye Disease Laboratory in 2004 with superficial corneal alterations were submitted to corneal specimen collection by impression cytology filter paper to investigate the presence of Acanthamoeba sp cysts. Two impression

  6. Acanthamoeba keratitis.

    OpenAIRE

    Hay, J; Seal, D V; Kirkness, C M

    1993-01-01

    Acanthamoeba keratitis, common in soft lens wearers, is not commonly isolated. The reports of Acanthamoeba keratitis in Indian literature are few. We report here a case of Acanthamoeba Keratitis in a medical student using soft contact lenses, initially diagnosed and treated as a bacterial and later as a viral corneal ulcer, who responded extremely well to medical line of therapy.

  7. Queratitis por Acanthamoeba sp.: primer caso confirmado por aislamiento y tipificación molecular en Bahía Blanca, provincia de Buenos Aires, Argentina Acanthamoeba sp. keratitis: first case confirmed by isolation and molecular typification in Bahía Blanca, Buenos Aires Province, Argentina

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    M. L. Gertiser

    2010-06-01

    Full Text Available Algunas especies del género Acanthamoeba provocan queratitis amebiana (QA, una infección de la córnea muy dolorosa, generalmente unilateral, con compromiso importante de la visión. Se presenta el caso de una mujer de 31 años usuaria de lentes de contacto con hábitos inadecuados de higiene y conservación de las lentes. La paciente consultó por enrojecimiento y dolor intenso en el ojo derecho, de dos meses de evolución. Luego del examen oftalmológico y ante la sospecha de una etiología parasitaria se realizó una biopsia de la zona lesionada, que se destinó al análisis bacteriológico y parasitológico en el laboratorio. También se remitieron los líquidos de lavado y el estuche de las lentes. No se detectó crecimiento bacteriano en las muestras. Los cultivos para la búsqueda de Acanthamoeba resultaron positivos en todos los especímenes analizados. Las amebas aisladas fueron clasificadas morfológica y molecularmente como pertenecientes al género Acanthamoeba. El presente trabajo muestra el primer caso de queratitis por Acanthamoeba de la ciudad de Bahía Blanca identificado por el laboratorio mediante procedimientos de alto valor diagnóstico.Some species of the Acanthamoeba genus cause keratitis, a very painful, most likely unilateral corneal infection , associated with eye and vision impairment. We here present a case of a 31-year-old female patient, a regular user of soft contact lenses without good practices of lens hygiene and handling. The patient attended medical consultation after two months of inflammation and pain in her right eye. After ophthalmological studies, and due to suspicion of a parasitic infection, a biopsy was performed and the sample submitted for bacteriological and parasitological analyses. Moreover, contact lens holders and lens cleaning solutions were studied. The samples yielded negative results for bacterial infection. However, cultivation of all samples showed the presence of amoeboid parasites

  8. Acanthamoeba meningoencephalitis

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    S R Chandra

    2014-01-01

    Full Text Available Report of a case of young immunocompetent male adult with autopsy proven acanthamoeba meningoencephalitis. The patient presented with a protracted febrile illness of 3 months duration with features of meningoencephalitis, this was followed by rapid deterioration while on anti tuberculous therapy and steroids and ended fatally. His magnetic resonance imaging showed features of hemorrhagic meningoencephalitis and magnetic resonance spectroscopy showed choline peak. Autopsy revealed necrotizing meningoencephalitis and intraocular colonization due to acanthamoeba.

  9. Acanthamoeba encephalitis

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    Kaushal V

    2008-01-01

    Full Text Available Central nervous system infection with free-living amoebae is rare. We present a fatal case of Acanthamoeba encephalitis in a 63-year-old female from India where acanthamoebae were demonstrated and cultured from CSF. In spite of treatment with amphotericin B, fluconazole and rifampicin the patient did not survive. Amoebic infection should be suspected in a patient of encephalitis of unexplained aetiology as timely diagnosis can lead to a favourable outcome.

  10. [Acanthamoeba keratitis].

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    Bouheraoua, N; Labbé, A; Chaumeil, C; Liang, Q; Laroche, L; Borderie, V

    2014-10-01

    Early diagnosis and appropriate therapy are key elements for a good prognosis in Acanthamoeba keratitis (AK). AK should be considered in any case of corneal trauma complicated by exposure to soil or contaminated water, and in all contact lens (CL) wearers. A presumptive diagnosis of AK can be made clinically and with in vivo confocal microscopy, although a definitive diagnosis requires identification of Acanthamoeba on direct scraping, histology, or identification of Acanthamoeba DNA by polymerase chain reaction (PCR). We use cysticidal drugs for treating AK because encysted forms are more resistant than trophozoites to treatment. The treatment protocol used a biguanide (PHMB 0.02% or chlorhexidine 0.02%) and a diamidine (propamidine 0.1% or hexamidine 0.1%). New diagnostic modalities and more specific topical anti-amoebic treatments would substantially benefit patients with AK. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  11. Acanthamoeba Keratitis FAQs

    Science.gov (United States)

    ... this? Submit What's this? Submit Button Parasites Home Acanthamoeba Keratitis FAQs Recommend on Facebook Tweet Share Compartir Frequently Asked Questions What is Acanthamoeba keratitis? Acanthamoeba keratitis is a rare but serious ...

  12. Conjunctivitis presumably due to Acanthamoeba

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    Ruthes, Ana Cristina de Carvalho; Wahab, Sâmia; Wahab, Najua; Moreira, Hamilton; Moreira, Luciane

    2004-01-01

    OBJETIVO: Abordar quatro casos de conjuntivite presumível por Acanthamoeba, descrevendo o diagnóstico, considerando sinais e sintomas e o tratamento instituído. MÉTODOS: Foram estudados casos de conjuntivite presumível por Acanthamoeba diagnosticados no Hospital de Olhos do Paraná (HOP), no período de setembro/1998 a janeiro/2002. Todos os olhos estudados foram submetidos a um protocolo de investigação que incluía exame oftalmológico completo, microbiologia e cultura de secreções conjuntivais...

  13. Asociación de las poliaminas con enfermedades inflamatorias intestinales. Influencia sobre el epitelio y la motilidad intestinal.

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    Flórez Escanciano, Blanca Henar

    2014-01-01

    Las poliaminas son unas moléculas catiónicas con múltiples funciones relacionadas con el desarrollo del epitelio intestinal y alteraciones del sistema inmunitario, ambos aspectos se encuentran afectados en los pacientes con enfermedades inflamatorias intestinales. Dichas poliaminas podrían ejercer un papel importante en la fisiología de las enfermedades inflamatorias intestinales y ser útiles como posibles marcados diagnósticos, por lo que determinamos mediante HPLC aminas biógenas de pacient...

  14. Polirradiculopatía inflamatoria crónica sensitiva

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    Paz Zuberbuhler

    2013-06-01

    Full Text Available La polirradiculopatía inflamatoria crónica sensitiva es una entidad definida, frecuentemente subdiagnosticada y potencialmente tratable. Debe ser sospechada en pacientes con ataxia sensitiva, estudios de conducción nerviosa normales y una resonancia magnética que muestre engrosamiento y realce con gadolinio de las raíces lumbosacras. Presentamos el caso de un hombre de 57 años de edad con marcada ataxia sensitiva en pierna izquierda. Al examen físico presentaba fuerza conservada, reflejos osteotendinosos disminuidos, tacto fino y superficial reducidos por debajo de las rodillas; abatiestesia y apalestesia en ambos pies. Los estudios de conducción nerviosa eran normales, los potenciales evocados somatosensitivos tibiales con ausencia de respuesta bilateral. El líquido cefalorraquídeo presentaba hiperproteinorraquia sin células. La resonancia magnética mostró engrosamiento y realce con gadolinio de las raíces lumbosacras. El paciente fue tratado con inmunoglobulina endovenosa (IgEV a 2 g/kg durante 5 días, con buena respuesta. La evolución clínica, la hiperproteinorraquia, el realce de raíces en la resonancia magnética, la buena respuesta a la inmunoterapia y la exclusión de otras causas de ataxia sensitiva fueron compatibles con el diagnóstico de polirradiculopatía inflamatoria crónica sensitiva. Para el diagnóstico de esta enfermedad se requiere la identificación del compromiso aislado de las raíces sensitivas.

  15. Variables psicológicas y calidad de vida en la enfermedad inflamatoria intestinal

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    Iglesias Rey, Marta

    2013-01-01

    Antecedentes: Bajo la denominación de enfermedad inflamatoria intestinal se incluyen un grupo de enfermedades crónicas del tracto gastrointestinal entre las que destacan por su gravedad y prevalencia, la enfermedad de Crohn y la colitis ulcerosa. El curso clínico se caracteriza por la aparición de brotes de reagudización de diversa gravedad y periodos de remisión en los que el paciente se encuentra clínicamente estable. El comienzo en edades tempranas, la cronicidad, necesidad de cirugía y ho...

  16. Experiencia con rituximab en miopatía inflamatoria idiopática refractaria

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    Elmer R. García-Salazar; Felipe Becerra; José Chávez

    2013-01-01

    Se describe las características clínicas y de laboratorio de dos pacientes que recibieron rituximab por miopatía inflamatoria idiopática (MII). Ellas eran refractarias a tratamiento convencional con DARMES, por lo que recibieron rituximab 1 gramo cada 14 días, en dos infusiones en ciclo semestral. En las historias clínicas se obtuvo los datos clínicos de fuerza muscular proximal, lesiones cutáneas patognomónicas, elevación de CPK, TGO, DHL y VSG, resultados de electromiografía, biopsia muscul...

  17. Experiencia con rituximab en miopatía inflamatoria idiopática refractaria

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    García-Salazar, Elmer R.; Becerra, Felipe; Chávez, José

    2014-01-01

    Se describe las características clínicas y de laboratorio de dos pacientes que recibieron rituximab por miopatía inflamatoria idiopática(MII). Ellas eran refractarias a tratamiento convencional con DARMES, por lo que recibieron rituximab 1 gramo cada 14 días, en dosinfusiones en ciclo semestral. En las historias clínicas se obtuvo los datos clínicos de fuerza muscular proximal, lesiones cutáneaspatognomónicas, elevación de CPK, TGO, DHL y VSG, resultados de electromiografía, biopsia muscular ...

  18. Miopatía inflamatoria con compromiso inicial de músculos respiratorios y artritis reumatoidea

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    Martín Hunter; Irene Telias; Victoria Collado; Judith Sarano; Clarisa Álvarez; Juan Pablo Suárez

    2014-01-01

    Las miopatías inflamatorias constituyen un grupo heterogéneo de enfermedades musculares adquiridas de presentación subaguda, crónica y a veces aguda. Las entidades clínicas más frecuentes son la dermatomiositis, la polimiositis, la miositis necrotizante autoinmune y la miositis por cuerpos de inclusión. Suelen presentarse con debilidad muscular con predominio proximal y simétrica, pero rara vez comprometen los músculos respiratorios. Presentamos el caso de una mujer de 39 años con miopatía in...

  19. Stable transfection of Acanthamoeba.

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    Yin, J; Henney, H R

    1997-03-01

    The promoter activity of an Acanthamoeba polyubiquitin gene was analyzed in its homologous system. A modified calcium phosphate transfection method using a neomycin marker vector was developed to achieve highly efficient transfection of the Acanthamoeba polyubiquitin gene into Acanthamoeba cells. In this transfection procedure, the calcium phosphate-DNA complex was formed gradually in the medium during incubation with cells and precipitated on the cells. The crucial factors for obtaining efficient transfection were the pH (6.95) of the transfection buffer used for the calcium phosphate precipitation and the amount (25 micrograms/96-well tissue culture plate) and form (circular) of transfecting DNA. Under these conditions, Acanthamoeba isolate 1B6 was transfected at an efficiency of about 40% with the constructed vector pOPSBU, a pOP13CAT-based polyubiquitin gene incorporated neomycin resistance vector. Acanthamoeba polyphaga was transfected at an efficiency of about 10% with this vector. Transfection of both Acanthamoeba strains appeared to result in low copy plasmid integration (about two copies per cell are suggested). The chloramphenicol acetyltransferase (CAT) assays showed that the promoter of the Acanthamoeba polyubiquitin gene in the constructed vector was especially strong in A. polyphaga, thus the pOPSBU-Acanthamoeba system may be useful for the construction of cDNA expression libraries, as well as for the expression of cloned genes.

  20. Inmunogenicidad de la vacuna frente al virus de la hepatitis B en pacientes con enfermedad inflamatoria intestinal

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    Olsen Rodríguez, Renée

    2017-01-01

    La colitis ulcerosa (CU) y la enfermedad de Crohn (EC) son patologías que se denominan conjuntamente enfermedad inflamatoria intestinal (EII). Su patogenia es poco conocida, pero si se sabe que hay una respuesta inmune frente a estructuras del tubo digestivo. El tratamiento se basa es disminuir esta inmunogenicidad administrando corticoides, inmunosupresores o terapias biológicas. Todas estas circunstancias favorecen las infecciones y reactivaciones por el virus de la hepatitis B (VHB). La pr...

  1. Miopatía inflamatoria con compromiso inicial de músculos respiratorios y artritis reumatoidea

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    Martín Hunter

    2014-10-01

    Full Text Available Las miopatías inflamatorias constituyen un grupo heterogéneo de enfermedades musculares adquiridas de presentación subaguda, crónica y a veces aguda. Las entidades clínicas más frecuentes son la dermatomiositis, la polimiositis, la miositis necrotizante autoinmune y la miositis por cuerpos de inclusión. Suelen presentarse con debilidad muscular con predominio proximal y simétrica, pero rara vez comprometen los músculos respiratorios. Presentamos el caso de una mujer de 39 años con miopatía inflamatoria inespecífica que presentó insuficiencia respiratoria secundaria a hipoventilación alveolar por debilidad muscular y requirió asistencia respiratoria mecánica. Respondió favorablemente y de forma rápida tras el tratamiento instaurado con inmunosupresores (corticoides y metotrexato e inmunoglobulina humana endovenosa. Se utilizó ventilación no invasiva como alternativa a la intubación orotraqueal con adecuada tolerancia.

  2. Amiloidosis secundaria en la enfermedad inflamatoria intestinal Secondary amyloidosis in Chrohn's disease

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    S. Seijo Ríos

    2008-12-01

    Full Text Available La amiloidosis es una entidad clínica que se produce a consecuencia del depósito a nivel extracelular de un material proteico amorfo, causando una desorganización de la arquitectura normal de múltiples órganos y tejidos y, por tanto, una alteración funcional de los mismos. La amiloidosis secundaria es una complicación infrecuente pero muy grave que aparece en el contexto de neoplasias, enfermedades infecciosas e inflamatorias de curso crónico, como es el caso de la enfermedad inflamatoria intestinal, principalmente enfermedad de Crohn, ensombreciendo el pronóstico de estos pacientes. A continuación presentamos dos casos clínicos correspondientes a dos pacientes con enfermedad de Crohn que desarrollaron amiloidosis secundaria.Amyloidosis is a clinical entity that results from the deposition of an extracellular protein material that causes disruption in the normal architecture of multiple organs and tissues, and impairs their function. Secondary amyloidosis is a rare but serious complication that may worsen the prognosis of patients with cancer, infection or chronic inflammatory disease, including inflammatory bowel disease, particularly Crohn's disease. We report two cases of Crohn's disease associated with secondary amyloidosis.

  3. La Peroxidación lipídica en la enfermedad periodontal inflamatoria experimental

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    Bárbara E García Triana

    1998-04-01

    Full Text Available La peroxidación de los lípidos de las membranas de los tejidos periodontales, parece estar implicada en la etiopatogenia de la enfermedad periodontal inflamatoria. En este estudio utilizamos perros Beagles, a los cuales se les provocó la enfermedad, por ligadura de los dientes de una hemiarcada, mientras la hemiarcada opuesta se empleó como control. Al final del experimento, las variables estudiadas (profundidad del surco gingival, altura ósea y niveles de malonil-dialdehído fueron significativamente superiores en la hemiarcada ligada, con respecto a la no ligada. Concluimos que el uso de este modelo es factible en nuestras condiciones. Estos resultados apoyan la teoría de la participación de la peroxidación lipídica en la etiopatogenia de la enfermedad periodontal inflamatoria.The lipid peroxidation of the periodontal membranes seems to be involved in the pathogenesis of the periodontal disease. We used for this study Beagles dogs which were caused such a disease by applying a ligature to a dental hemiarch teeth whereas the opposite hemiarch was used as a control. At the end of the experiment, the studied variables (gingival sulcus depth, bone height and malonyl-dialdehyde levels were significantly higher in the ligated hemiarch. We concluded that the use of this model is feasible in our conditions. These results back up the theory of the role of lipid peroxidation in the pathogenesis of the periodontal diseases.

  4. La reacción inflamatoria en la fisiopatogenia de la obesidad

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    Ma. Victoria Domínguez García

    2012-01-01

    Full Text Available La obesidad se caracteriza por inflamación crónica. Entre los biomarcadores de inflamación encontramos las citocinas producidas por los adipocitos y los macrófagos: TNF - a, IL - 6, leptina, adiponectina y resistina. La relación adipocito-macrófago impacta la respuesta inflamatoria observada en la obesidad, la cual tiene una relación directa con la cantidad de macrófagos acumulados en el tejido adiposo blanco, que contribuye a la producción de mediadores de la inflamación. En este documento se hará una revisión de las principales moléculas involucradas en la generación de inflamación en la obesidad, y la relación entre macrófagos y adipocitos.

  5. Experiencia con rituximab en miopatía inflamatoria idiopática refractaria

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    Elmer R. García-Salazar

    2013-10-01

    Full Text Available Se describe las características clínicas y de laboratorio de dos pacientes que recibieron rituximab por miopatía inflamatoria idiopática (MII. Ellas eran refractarias a tratamiento convencional con DARMES, por lo que recibieron rituximab 1 gramo cada 14 días, en dos infusiones en ciclo semestral. En las historias clínicas se obtuvo los datos clínicos de fuerza muscular proximal, lesiones cutáneas patognomónicas, elevación de CPK, TGO, DHL y VSG, resultados de electromiografía, biopsia muscular y de piel. Ninguno de los dos casos presentó reacción medicamentosa ni infecciones durante y posterior a las infusiones. Rituximab mostró efectividad en la respuesta clínica y enzimática en estas pacientes con dermatomiositis refractarias a corticoides y DARMES tradicionales.

  6. Pleuresia inflamatoria en la infancia: Conducta quirúrgica

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    Arturo L. Delgado Delgado

    2003-04-01

    Full Text Available La neumonía complicada por pleuresía ha sido siempre un proceso que ha afectado la morbilidad y mortalidad en la edad pediátrica y en ocasiones necesita de algún proceder quirúrgico para su solución. La decisión inicial de si realizar solo una punción pleural o agregarle una pleurostomía mínima, puede ser controversial, por lo que se decidió realizar un estudio de todos aquellos niños que fueron ingresados en el Hospital Pediátrico Universitario de San Miguel del Padrón con neumonía complicada por pleuresía inflamatoria (pleuresía durante un proceso inflamatorio pulmonar, a los cuales hubo que realizarles algún proceder quirúrgico para la solución de su derrame, en el período de enero de 2000 a enero de 2001; se estudiaron los expedientes clínicos de 10 pacientes; se les conformaron tablas y figuras. El grupo de edad más afectado fue el de 1 a 5 años con un 40 %. El sexo no tuvo preponderancia y la localización más frecuente del proceso inflamatorio (90 % fueron el pulmón derecho, y entre estas la base derecha con un 40 %. Al 50 % de los pacientes se le realizó solamente una punción pleural y a la otra mitad se le añadió una pleurostomía, y tenía el 30 % en este último grupo más de 150 mL en la punción inicial; a 5 pacientes hubo que realizarles una pleurostomía mínima. Con estos resultados se consideró que en el momento de la punción pleural inicial el hallazgo macroscópico de aspecto fibrino purulento es indicativo de pleurostomía, así como este aspecto en el líquido de una segunda punción de ser necesario ésta y una celularidad mayor de 175 ´ 106, y una glucosa menor de 1 mmol/L en el microscópico del líquido de la primera, si se hace necesario realizar una segunda punción o los mismos resultados del líquido proveniente de esta segunda o cualquier otra punción.Pneumonia complicated due to pleurisy has always been a process affecting morbidity and mortality at the pediatric age and on

  7. Enzimas proteolíticas relacionadas con la enfermedad periodontal inflamatoria

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    Bárbara E. García Triana

    1998-08-01

    Full Text Available La enfermedad periodontal inflamatoria ocasiona la destrucción de los tejidos que protegen y soportan al diente; es por eso de gran importancia el papel que pueden desempeñar las enzimas que sean capaces de degradar la matriz del tejido conectivo, como las enzimas proteolíticas. Existen evidencias de que las metaloproteinasas de la matriz, las proteasas leucocitarias y las bacterianas, pueden participar en la etiopatogenia de esta enfermedad. Su acción es regulada en los tejidos, por la presencia de inhibidores específicos, de manera que un desbalance proteasas-inhibidores a favor de los primeros, conduciría a la destrucción de las proteínas de la matriz del tejido conectivo. A su vez, en la actividad proteolítica influyen diferentes factores, que de manera global, inducen un fenotipo degradativo o formativo, y que por lo tanto, podrían estar involucrados en la etiopatogenia de la enfermedad periodontal inflamatoria.The periodontal disease brings about the destruction of the protective and supporting tissues of the teeth, therefore, the role of enzymes capable of degrading connective tissue matrix is of great importance. There are evidences of the possible involvement of the matrix metalloproteinases, leukocyte proteases and bacterial proteases in the pathogenesis of such disease. Their action is controlled by specific inhibitors in the tissues. This means that any protease-inhibitor imbalance favouring the presence of proteases may lead to the destruction of matrix connective tissue. In turn, proteolytic activity is influenced by different factors that globally induce a degradative or formative phenotype, and thus, may be involved in the pathogenesis of the periodontal disease.

  8. Hipnosis clínica en un caso de enfermedad inflamatoria intestinal

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    J. C. FERNÁNDEZ MÉNDEZ

    2000-01-01

    Full Text Available Un sujeto de veinte años con una enfermedad inflamatoria intestinal fue tratado con hipnosis. Hasta donde sabemos es el primer informe que documenta el empleo de la hipnosis clínica en un paciente con enfermedad de Crohn, para reducir el estrés y afrontar las demandas originadas por la patología digestiva. Además, otro aspecto importante en el presente trabajo, es el registro exhaustivo y consecutivo de la sintomatología gastrointestinal, un punto débil en la gran mayoría de los trabajos precedentes. Al finalizar la intervención psicológica disminuyó notablemente el nivel de intensidad del estrés, el número de deposiciones diarias así como la intensidad del dolor abdominal. Estos resultados se mantuvieron a lo largo del seguimiento.

  9. Manifestaciones reumatológicas de la enfermedad inflamatoria intestinal Rheumatologic manifestations of inflammatory bowel disease

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    Octavio Germán Muñoz Maya

    2006-01-01

    Full Text Available La enfermedad inflamatoria intestinal (EII se caracteriza por la activación inapropiada del sistema inmune de la mucosa intestinal y sus dos formas de presentación son: la colitis ulcerativa y la enfermedad de Crohn. Las manifestaciones extraintestinales se presentan hasta en el 36% de los pacientes y pueden comprometer cualquier órgano o sistema. La disfunción inmune se caracteriza por el desequilibrio entre los mediadores proinflamatorios y los antinflamatorios y se expresa como una enfermedad sistémica. Las manifestaciones reumatológicas asociadas a la EII son de tres tipos: la artritis periférica, la espondiloartropatía y una tercera categoría que incluye lesiones dérmicas, oftálmicas y del metabolismo óseo, entre otras. El manejo de estas manifestaciones se basa en la terapia sistémica para el control de la actividad inflamatoria local utilizando esteroides, derivados de la 5-ASA, inmunomoduladores y, en los últimos años, terapia anti-TNF. The main feature of inflammatory bowel disease (IBD is the continuous activation of the mucosa-associated immune system; the disease has two major forms of presentation: ulcerative colitis and Crohn´s disease. The extraintestinal manifestations are present in 36% of patients, and any organ can be affected. There is an imbalance between proinflammatory and antinflammatory cytokines leading to a systemic disease. The rheumatologic manifestations of the IBD are: Peripheral arthritis, spondyloarthropathy and a third category that includes dermic and ocular lesions as well as metabolic bone disease. Control of the extraintestinal manifestations is based on systemic therapy with steroids, 5-ASA derivatives and biological anti-TNF therapy.

  10. Reabsorción radicular inflamatoria en sujetos con tratamiento ortodóntico. Cartagena (Colombia

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    Farith González Martínez

    2012-01-01

    Full Text Available Objetivo: Determinar la ocurrencia de Reabsorción Radicular Inflamatoria en sujetos sometidos a movimiento dental con cuatro técnicas de ortodoncia. Materiales y métodos: Estudio de cohorte con seguimiento a un año, evaluando la reabsorción radicular inflamatoria con cuatro técnicas de ortodoncia, a partir de la escala de Levander and Malmgren. Las mediciones se realizaron en 176 dientes, usando tres radiografías periapicales por participante cada tres meses. Los datos fueron analizados a través de proporciones de incidencia. El Riesgo Relativo se utilizó para la asociación entre la presencia de reabsorción y la técnica de ortodoncia, con intervalos de confianza del 95 %. Para la significancia estadística se aplicaron los test de Kruskal Wallis, Mc-Nemar y Fischer. Se realizó un análisis multivariable por regresión logística. Resultados: La incidencia de Reabsorción Radicular fue del 68,2 %, presentándose a los nueve y doce meses. Se observaron cambios radiculares con grado 1 en 8,5 % de los dientes y grado 2 con 2,8 %, siendo laterales los de mayor proporción (6,3%. En los dientes sometidos a la técnica de Arco de canto se encontró un riesgo 3,3 veces mayor en comparación con las técnicas pre-ajustadas. Conclusiones: Existe Reabsorción Radicular en los dientes sometidos a movimiento dental durante el tratamiento de ortodoncia, sin embargo, estos cambios se consideran leves y dependen de la biomecánica utilizada en cada técnica.

  11. Impacto de la fatiga en la percepción de salud en la enfermedad inflamatoria intestinal.

    OpenAIRE

    Castillo Cejas, María Dolores

    2011-01-01

    La salud de los pacientes con enfermedad inflamatoria intestinal (EII) está afectada por la fatiga, que condiciona una baja calidad de vida. Este estudio administró cuestionarios de calidad de vida y fatiga a 110 pacientes con EII, cuantificando fatiga y correlacionándola con la actividad, se determinó la afectación de la calidad de vida. Los resultados mostraron relación inversa entre fatiga y actividad de EII, con diferencias estadísticamente significativas según brote o remisión de la enfe...

  12. [Keratitis due to Acanthamoeba].

    Science.gov (United States)

    Pérez-Irezábal, Julio; Martínez, Inés; Isasa, Patricia; Barrón, Jorge

    2006-10-01

    Free-living amebae appertaining to the genus Acanthamoeba, Naegleria and Balamuthia are the most prevalent protozoa found in the environment. These amebae have a cosmopolitan distribution in soil, air and water, providing multiple opportunities for contacts with humans and animals, although they only occasionally cause disease. Acanthamoeba spp. are the causative agent of granulomatous amebic encephalitis, a rare and often fatal disease of the central nervous system, and amebic keratitis, a painful disease of the eyes. Keratitis usually follows a chronic course due to the delay in diagnosis and subsequent treatment. The clear increase in Acanthamoeba keratitis in the last 20 years is related to the use and deficient maintenance of contact lenses, and to swimming while wearing them. The expected incidence is one case per 30,000 contact lens wearers per year, with 88% of cases occurring in persons wearing hydrogel lenses. This review presents information on the morphology, life-cycle and epidemiology of Acanthamoeba, as well as on diagnostic procedures (culture), appropriate antimicrobial therapy, and prevention measures.

  13. Pathogenesis of Acanthamoeba Keratitis

    Science.gov (United States)

    Panjwani, Noorjahan

    2010-01-01

    Acanthamoeba keratitis (AK) is a serious infection of the cornea. At present, diagnosis of the disease is not straightforward and treatment is very demanding. While contact lens wear is the leading risk factor for AK, Acanthamoeba parasites are increasingly recognized as an important cause of keratitis in non-contact lens wearers. The first critical step in the pathogenesis of infection is the adhesion of the microbe to the surface of the host tissues. Acanthamoebae express a major virulence protein, the mannose-binding protein (MBP), which mediates the adhesion of amoebae to the surface of the cornea. The MBP is a transmembrane protein with characteristics of a typical cell surface receptor. Subsequent to the MBP-mediated adhesion to host cells, the amoebae produce a contact-dependent metalloproteinase and several contact-independent serine proteinases. These proteinases work in concert to produce a potent cytopathic effect (CPE) involving killing of the host cells, degradation of epithelial basement membrane and underlying stromal matrix, and penetration into the deeper layers of the cornea. In the hamster animal model, oral immunization with the recombinant MBP protects against AK, and this protection is associated with an increased level of anti-MBP IgA in tears of protected animals. Normal human tear fluid contains IgA antibodies against Acanthamoeba MBP that is likely to provide protection by inhibiting the adhesion of parasites to host cells. Indeed, in in vitro CPE assays, even a low concentration of tears (10 [MU]μL of undiluted tears per milliliter of media) almost completely inhibits Acanthamoeba-induced CPE. In addition to adherence-inhibiting, IgA-mediated protection, human tears also contain IgA-independent factors that provide protection against Acanthamoeba-induced CPE by inhibiting the activity of cytotoxic proteinases. Characterization of the CPE-inhibitory factors of human tears should lead to a better understanding of the mechanism by which the

  14. Tratamiento, mediante bloqueo de moléculas CD20 con Rituximab, en miopatías Inflamatorias Idiopáticas refractarias a tratamiento convencional

    OpenAIRE

    Chinchilla Palomares, Eduardo

    2012-01-01

    Las miopatías inflamatorias idiopáticas (MII) constituyen un grupo heterogéneo de enfermedades adquiridas, de probable mecanismo inflamatorio autoinmune, que se caracterizan por debilidad muscular e infiltrado inflamatorio local o difuso, junto con necrosis de las fibras musculares, en la biopsia muscular. Afectan preferentemente a la musculatura estriada. Dentro de este grupo se incluyen tres variantes principales: la dermatomiositis (DM), la polimiositis (PM) y la miositis con cuerpos de in...

  15. Biology and pathogenesis of Acanthamoeba

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    Siddiqui Ruqaiyyah

    2012-01-01

    Full Text Available Abstract Acanthamoeba is a free-living protist pathogen, capable of causing a blinding keratitis and fatal granulomatous encephalitis. The factors that contribute to Acanthamoeba infections include parasite biology, genetic diversity, environmental spread and host susceptibility, and are highlighted together with potential therapeutic and preventative measures. The use of Acanthamoeba in the study of cellular differentiation mechanisms, motility and phagocytosis, bacterial pathogenesis and evolutionary processes makes it an attractive model organism. There is a significant emphasis on Acanthamoeba as a Trojan horse of other microbes including viral, bacterial, protists and yeast pathogens.

  16. Biology and pathogenesis of Acanthamoeba

    Science.gov (United States)

    2012-01-01

    Acanthamoeba is a free-living protist pathogen, capable of causing a blinding keratitis and fatal granulomatous encephalitis. The factors that contribute to Acanthamoeba infections include parasite biology, genetic diversity, environmental spread and host susceptibility, and are highlighted together with potential therapeutic and preventative measures. The use of Acanthamoeba in the study of cellular differentiation mechanisms, motility and phagocytosis, bacterial pathogenesis and evolutionary processes makes it an attractive model organism. There is a significant emphasis on Acanthamoeba as a Trojan horse of other microbes including viral, bacterial, protists and yeast pathogens. PMID:22229971

  17. Infliximab en pacientes con enfermedad ocular inflamatoria, refractarios a DARMES

    OpenAIRE

    Elmer R. García-Salazar; Henry Terrazas; Javier Gonzales; Miguel Fernández

    2013-01-01

    Se describe la experiencia con infliximab (anticuerpo monoclonal con una potente acción antiinflamatoria) en el tratamiento de enfermedades oculares inflamatorias secundarias a patologías reumáticas y refractarias a drogas antirreumáticas modificadoras de la enfermedad (DARMES). Se evaluó el caso de una paciente de 50 años con artritis reumatoide (AR) de fondo activo y una paciente de 37 años con vasculitis anticuerpos anticitoplasma de neutrófilos especifico para mieloperoxidasa (ANCA MPO) s...

  18. Acanthamoeba infection after radial keratotomy.

    Science.gov (United States)

    Friedman, R F; Wolf, T C; Chodosh, J

    1997-03-01

    To describe a case of Acanthamoeba infection of the cornea after radial and astigmatic keratotomy. A 29-year-old man developed ulcerative keratitis in the right eye 6 weeks after uncomplicated radial and astigmatic keratotomy. Three sets of corneal cultures for bacteria and fungi were negative. Culture on non-nutrient agar grew Acanthamoeba organisms. Clinical improvement occurred after topical antiamebic therapy was instituted. Incisional keratotomy may predispose the cornea to delayed-onset infectious keratitis. Acanthamoeba should be considered as a possible cause of infection and should be cultured for in refractory cases.

  19. Eficacia histopatológica en la fase inflamatoria, proliferativa y osteogénica en la cicatrización alveolar post exodoncia aplicando matico (Piper angustifolium)

    OpenAIRE

    Pérez, Aurelia

    2016-01-01

    El presente estudio tiene como finalidad determinar la eficacia histopatológica en la fase inflamatoria, proliferativa y osteogénica de la cicatrización post exodoncia tratadas con Matico (Piper angustifolium). El estudio fue experimental, tuvo por finalidad saber el nivel de cicatrización histopatológica del Matico (Piper angustifolium) dentro de los alveolos post exodoncia, con un grupo de estudio de 15 conejos machos con un peso de 2.5 Kg, divididos en grupo control y grupo experimental (s...

  20. Confocal microscopy findings of Acanthamoeba keratitis.

    Science.gov (United States)

    Pfister, D R; Cameron, J D; Krachmer, J H; Holland, E J

    1996-02-01

    Tandem scanning confocal microscopy was performed on two patients with Acanthamoeba keratitis to provide images detailing characteristic findings of the disease. Although tandem scanning confocal microscopy of Acanthamoeba has been described in previous reports, Acanthamoeba keratitis has not been fully characterized with this instrument. In vivo confocal micrographs showed the double-walled structure of the Acanthamoeba cyst and associated radial keratoneuritis (perineuritis). We reviewed the records of two patients with a clinical diagnosis of Acanthamoeba keratitis, one with culture-proven Acanthamoeba and the other with a suspected Acanthamoeba infection. Slit-lamp biomicroscopy and in vivo tandem scanning confocal microscopy were performed. The images obtained were compared with images from patients without corneal disease. High-contrast round bodies suggestive of Acanthamoeba cysts, as previously described, and irregular forms suggestive of Acanthamoeba trophozoites were found by tandem scanning confocal microscopy. Additionally, we showed conclusively that under certain circumstances (that is, corneal scarring) tandem scanning confocal microscopy can resolve the double-walled structure of the Acanthamoeba ectocyst surrounding the endocyst. Furthermore, radial keratoneuritis was demonstrated, consisting of an irregularly swollen nerve fiber with probable amoebic infiltration. Confocal microscopy can be a useful, noninvasive imaging technique helpful in the study, diagnosis, and treatment of Acanthamoeba keratitis.

  1. A comparative study of two histological techniques for the identification of cytomegalovirus infection in colorectal biopsies from patients with chronic inflammatory bowel disease Estudio comparativo entre dos técnicas histológicas para el diagnóstico de infección por citomegalovirus en biopsias colorrectales de pacientes con enfermedad inflamatoria intestinal crónica idiopática

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    M. L. de Castro

    2009-10-01

    Full Text Available Background: the role that cytomegalovirus (CMV plays in inflammatory bowel disease (IBD is controversial. The diagnosis of CMV infection in IBD depends on viral identification with hematoxylin-eosin (HE or immunohistochemistry (IHC. Our aim was to compare the sensitivity of HE and IHC for this diagnosis in IBD patients. Patients and methods: a case-control study. Our database was searched for IBD patients with HE- or IHC-based CMV-positivity from 1997 to 2007. Controls were selected among IBD inpatients matched for age and year of diagnosis with CMV. Their clinical characteristics were analyzed. HE and IHC were performed on biopsies from cases and controls at 6 months before and after inclusion in the study. In the statistical analysis, p values below 0.05 were considered significant. Results: ten IBD patients with CMV infection were identified. IBD-CMV patients were more steroid-resistant or steroid-dependent (p = 0.03, and underwent a higher number of colonic biopsies (p = 0.03. From 97 biopsies analyzed, 12 were HE-negative and IHC-positive, and 3 showed reversed results. The sensitivity of HE was 58.6%, 95% CI (38.9-78.3, and that of IHC was 89.7%, 95% CI (76.8-100. We did not find a good level of agreement between both techniques: kappa value 0.55, 95% CI (0.36-0.75. CMV positivity with IHC was associated with the use of more than one immunosuppressant drug, OR 13.5, 95% CI (1.2-152.2. Antiviral treatment was useful for CMV patients with steroid-dependent and steroid-refractory IBD. Conclusions: IHC shows a 30% higher sensitivity than HE for the diagnosis of CMV infection in IBD patients. There is no good level of agreement between both histological techniques.Introducción: el papel que el citomegalovirus (CMV juega en la enfermedad inflamatoria intestinal (EII es controvertido. El diagnóstico de infección por CMV en estos pacientes reside en su identificación en el tejido colónico mediante hematoxilina-eosina (HE o inmunohistoqu

  2. FERTILIDAD Y EMBARAZO EN PACIENTES CON ENFERMEDADES INFLAMATORIAS INTESTINALES

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    ANDRÉS YARUR U., DR.

    2015-09-01

    Full Text Available Las Enfermedades Inflamatorias Intestinales (EII son entidades crónicas del tracto digestivo, que afectan frecuentemente a pacientes en edad reproductiva. Debido a las características de estas enfermedades y su tratamiento, existen múltiples desafíos. En este artículo, revisamos la evidencia más reciente con respecto a fertilidad y embarazo en pacientes con EII. En general, existe evidencia de que pacientes con EII tienen una mayor tasa de complicaciones durante el embarazo con respecto a pacientes sin EII. Sin embargo, esta diferencia está directamente asociada al grado de actividad de la enfermedad. La mayor parte de los fármacos hoy usados en el tratamiento de EII son considerados seguros durante el embarazo y se recomienda continuarlos, sobre todo considerando que el mayor riesgo de complicaciones está asociado a una enfermedad activa. Sin embargo es importante considerar las opciones caso a caso. Las dos grandes excepciones son metotrexato y talidomida que están completamente contraindicadas. La recomendación más importante es educar a toda paciente con EII en edad reproductiva, explicando que el embarazo debe llevarse a cabo cuando la enfermedad esté controlada y que la probabilidad de complicaciones está relacionada con el grado de actividad y severidad de la EII. Los médicos tratantes deben educar a las pacientes, enfatizando el seguimiento de los controles y tratamiento.

  3. Infliximab en pacientes con enfermedad ocular inflamatoria, refractarios a DARMES

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    Elmer R. García-Salazar

    2013-07-01

    Full Text Available Se describe la experiencia con infliximab (anticuerpo monoclonal con una potente acción antiinflamatoria en el tratamiento de enfermedades oculares inflamatorias secundarias a patologías reumáticas y refractarias a drogas antirreumáticas modificadoras de la enfermedad (DARMES. Se evaluó el caso de una paciente de 50 años con artritis reumatoide (AR de fondo activo y una paciente de 37 años con vasculitis anticuerpos anticitoplasma de neutrófilos especifico para mieloperoxidasa (ANCA MPO sin compromiso de órgano noble, ambas con escleritis bilateral y perforación con prolapso de iris del ojo izquierdo. Ellas recibieron infliximab EV en dosis de 3 a 5 mg/kg/dosis, según el esquema, a las 0, 2, 6 y 8 semanas. Infliximab resultó eficaz y seguro para el tratamiento de escleritis asociada a AR y vasculitis ANCA MPO positivo, refractaria a tratamiento con DARMES y corticoides en dosis altas. Los injertos de tejido esclerocorneal evolucionaron favorablemente con infliximab.

  4. Acanthamoeba castellanii STAT protein.

    Science.gov (United States)

    Kicinska, Anna; Leluk, Jacek; Jarmuszkiewicz, Wieslawa

    2014-01-01

    STAT (signal transducers and activators of transcription) proteins are one of the important mediators of phosphotyrosine-regulated signaling in metazoan cells. We described the presence of STAT protein in a unicellular, free-living amoebae with a simple life cycle, Acanthamoeba castellanii. A. castellanii is the only, studied to date, Amoebozoan that does not belong to Mycetozoa but possesses STATs. A sequence of the A. castellanii STAT protein includes domains similar to those of the Dictyostelium STAT proteins: a coiled coil (characteristic for Dictyostelium STAT coiled coil), a STAT DNA-binding domain and a Src-homology domain. The search for protein sequences homologous to A. castellanii STAT revealed 17 additional sequences from lower eukaryotes. Interestingly, all of these sequences come from Amoebozoa organisms that belong to either Mycetozoa (slime molds) or Centramoebida. We showed that there are four separated clades within the slime mold STAT proteins. The A. castellanii STAT protein branches next to a group of STATc proteins from Mycetozoa. We also demonstrate that Amoebozoa form a distinct monophyletic lineage within the STAT protein world that is well separated from the other groups.

  5. Acanthamoeba castellanii STAT protein.

    Directory of Open Access Journals (Sweden)

    Anna Kicinska

    Full Text Available STAT (signal transducers and activators of transcription proteins are one of the important mediators of phosphotyrosine-regulated signaling in metazoan cells. We described the presence of STAT protein in a unicellular, free-living amoebae with a simple life cycle, Acanthamoeba castellanii. A. castellanii is the only, studied to date, Amoebozoan that does not belong to Mycetozoa but possesses STATs. A sequence of the A. castellanii STAT protein includes domains similar to those of the Dictyostelium STAT proteins: a coiled coil (characteristic for Dictyostelium STAT coiled coil, a STAT DNA-binding domain and a Src-homology domain. The search for protein sequences homologous to A. castellanii STAT revealed 17 additional sequences from lower eukaryotes. Interestingly, all of these sequences come from Amoebozoa organisms that belong to either Mycetozoa (slime molds or Centramoebida. We showed that there are four separated clades within the slime mold STAT proteins. The A. castellanii STAT protein branches next to a group of STATc proteins from Mycetozoa. We also demonstrate that Amoebozoa form a distinct monophyletic lineage within the STAT protein world that is well separated from the other groups.

  6. Acanthamoeba castellanii metacaspase and Dictyostelium ...

    Indian Academy of Sciences (India)

    Caspases are cysteine proteases that are important regulators of programmed cell death in animals. Two novel relatives to members of the caspase families metacaspases and paracaspase have been discovered. Metacaspase type-1 was identified in Acanthamoeba castellanii, an opportunistic protozoan parasite that ...

  7. Hiperplasia Fibrosa Inflamatoria: reporte de un caso Inflammatory Fibrous Hyperplasia: case report

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    A Casian Romero

    2011-08-01

    Full Text Available Introducción: La Hiperplasia Fibrosa Inflamatoria es una alteración caracterizada por un agrandamiento del tejido conectivo; se considera una lesión reactiva ya que se presenta como respuesta a una irritante crónico local; es una lesión común en pacientes adolescentes y de edad adulta debido a que su etiología principal se asocia a maloclusión, al uso de aparatología protésica u ortodóntica mal ajustada, así como a la presencia de biofilm. Sin embargo, la población infantil, principalmente en dentición mixta, no está exenta de presentar esta alteración, aunque en menor proporción. Objetivo: Presentar el caso clínico de un paciente en dentición mixta que presenta una Hiperplasia Fibrosa Inflamatoria con el fin de presentar las características clínicas e histopatológicas de la lesión, enfatizando la importancia de un temprano y correcto diagnóstico. Presentación del Caso: Paciente masculino de 8 años de edad que se presenta a la clínica por presentar lesiones cariosas y malposición dental. A la exploración se observa un agrandamiento gingival localizado, en el órgano dentario 41. Se decide tomar una biopsia de la lesión para establecer el diagnóstico. Conclusión: Debido a que existen varias lesiones con características clínicas muy similares a las que presentaba el paciente, es necesario conocer los diagnósticos diferenciales, así como realizar el diagnóstico temprano de la lesión para poder llevar a cabo un tratamiento eficaz y adecuado.Introduction: The Inflammatory Fibrous Hyperplasia (IFH is a disorder consisting in a connective tissue overgrowth; it is considered a reactive lesion because it appears in response to a chronic and local irritant; this is a very common oral lesion in adolescents and adults, its etiology is associated with dental malocclusion, use of over-extended prosthetic and orthodontic appliances, and with the presence of biofilm (plaque. Nevertheless, child population, mainly patients

  8. Acanthamoeba Infection in a Drowning Child.

    Science.gov (United States)

    Gunawan, Prastiya Indra; Idarto, Areta; Saharso, Darto

    2016-05-01

    Acanthamoeba infection is a potential life-threatening complication of drowning. The management of drowning-associated Acanthamoeba infection remains controversial. Survival reports on Acanthamoeba infection have been on case reports only. A 2-year-old, previously healthy Indonesian boy presented with decreased consciousness and inadequate breathing, followingdrowning. The event was unsupervised with unknown estimated time of submersion. Resuscitation was commenced and mechanical ventilated was applied. Sputum specimen revealed alive Acanthamoeba with pseudopods and cysts. Sputum culture resulted in Pseudomonas aeruginosa and cerebrospinal fluid was supportive for Acanthamoeba with 1-3 trophozoites and cyst. Imaging of the head showed cerebral edema and encephalitis. The patient received intravenous ceftazidime, metronidazole, fluconazole and rifampicin. The patient's consciousness was unsatisfactory regained resulting in an altered mental status. No treatment so far has given a succesful outcome for Acanthamoeba. In this case, management with metronidazole, rifampicin and fluconazole showed regain of consciousness resulting in altered mental status.

  9. Acanthamoeba sp.: un caso de queratitis no relacionada con el uso de lentes de contacto Acanthamoeba sp.: a case report in a non-contact lens wearer

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    Claudia Menghi

    2012-12-01

    Full Text Available La queratitis por Acanthamoeba sp. generalmente se relaciona con el uso de lentes de contacto y en menor proporción se vincula con el contacto con agua contaminada. Se caracteriza por una disminución de la capacidad visual y la presencia de un fuerte dolor ocular. al examen clínico, puede confundirse con una infección herpética. Si la infección no es diagnosticada y tratada a tiempo en forma adecuada, puede culminar en la perforación de la córnea y, eventualmente, en la pérdida del ojo. en este trabajo se informa uno de los pocos casos registrados de queratitis por Acanthamoeba sp. no relacionada con el uso de lentes de contacto.Acanthamoeba sp. keratitis is generally related to wearing contact lenses, and, to a lesser extent, to contaminated water. it is characterized by reduced visual capacity and the presence of severe ocular pain. Clinically, it can be mistaken for a herpes infection. if it is not diagnosed, and timely and adequately treated, it can result in corneal perforation and, eventually, in vision loss. One of the few registered cases of Acanthamoeba sp. keratitis not related to the use of contact lenses is herein reported.

  10. Acanthamoeba endophthalmitis in acquired immunodeficiency syndrome.

    Science.gov (United States)

    Heffler, K F; Eckhardt, T J; Reboli, A C; Stieritz, D

    1996-10-01

    To report the findings of Acanthamoeba endophthalmitis in a patient with acquired immunodeficiency syndrome (AIDS). A 35-year-old man with AIDS and Acanthamoeba infection of the skin and lungs was treated for a granulomatous uveitis in the left eye. The left eye developed mutton-fat keratic precipitates, iris granulomas, cataract, hypotony, and choroidal infiltrates. Aqueous and vitreous specimens were positive for Acanthamoeba cysts. Topical and systemic antiamebic medications decreased the inflammation but failed to control the infection. Acanthamoeba infection should be considered in the differential diagnosis of uveitis in patients with AIDS.

  11. Drug-resistant severe Acanthamoeba keratitis caused by rare T5 Acanthamoeba genotype.

    Science.gov (United States)

    Iovieno, Alfonso; Oechsler, Rafael A; Ledee, Dolena R; Miller, Darlene; Alfonso, Eduardo C

    2010-05-01

    To describe a case of severe and drug-resistant Acanthamoeba keratitis in a contact lens wearer caused by atypical T5 Acanthamoeba genotype (Acanthamoeba lenticulata). Report of a case, Acanthamoeba DNA amplification and sequencing. A 61-year-old patient was referred to our clinic with a 2-week history of keratitis. Acanthamoeba keratitis (AK) was diagnosed using confocal microscopy and corneal scraping culture. Using polymerase chain reaction (PCR) and DNA sequencing, the organism was classified as a T5 genotype (A. lenticulata). The keratitis continued to progress despite topical antiamoebic therapy and ultimately led to enucleation of the affected eye. T5 genotype Acanthamoeba can cause severe AK. Atypical Acanthamoeba genotypes could be associated with worse prognosis and resistance to therapy.

  12. Acanthamoeba Migration in an Electric Field

    Science.gov (United States)

    Rudell, Jolene Chang; Gao, Jing; Sun, Yuxin; Sun, Yaohui; Chodosh, James; Schwab, Ivan; Zhao, Min

    2013-01-01

    Purpose. We investigated the in vitro response of Acanthamoeba trophozoites to electric fields (EFs). Methods. Acanthamoeba castellanii were exposed to varying strengths of an EF. During EF exposure, cell migration was monitored using an inverted microscope equipped with a CCD camera and the SimplePCI 5.3 imaging system to capture time-lapse images. The migration of A. castellanii trophozoites was analyzed and quantified with ImageJ software. For analysis of cell migration in a three-dimensional culture system, Acanthamoeba trophozoites were cultured in agar, exposed to an EF, digitally video recorded, and analyzed at various Z focal planes. Results. Acanthamoeba trophozoites move at random in the absence of an EF, but move directionally in response to an EF. Directedness in the absence of an EF is 0.08 ± 0.01, while in 1200 mV/mm EF, directedness is significantly higher at −0.65 ± 0.01 (P Acanthamoeba move directionally in a three-dimensional (3D) agar system as well when exposed to an EF. Conclusions. Acanthamoeba trophozoites move directionally in response to an EF in a two-dimensional and 3D culture system. Acanthamoeba trophozoite migration is also voltage-dependent, with increased directionality with increasing voltage. This may provide new treatment modalities for Acanthamoeba keratitis. PMID:23716626

  13. Acanthamoeba and Dictyostelium Use Different Foraging Strategies.

    Science.gov (United States)

    Kuburich, Nick A; Adhikari, Nirakar; Hadwiger, Jeffrey A

    2016-12-01

    Amoeba often use cell movement as a mechanism to find food, such as bacteria, in their environment. The chemotactic movement of the soil amoeba Dictyostelium to folate or other pterin compounds released by bacteria is a well-documented foraging mechanism. Acanthamoeba can also feed on bacteria but relatively little is known about the mechanism(s) by which this amoeba locates bacteria. Acanthamoeba movement in the presence of folate or bacteria was analyzed in above agar assays and compared to that observed for Dictyostelium. The overall mobility of Acanthamoeba was robust like that of Dictyostelium but Acanthamoeba did not display a chemotactic response to folate. In the presence of bacteria, Acanthamoeba only showed a marginal bias in directed movement whereas Dictyostelium displayed a strong chemotactic response. A comparison of genomes revealed that Acanthamoeba and Dictyostelium share some similarities in G protein signaling components but that specific G proteins used in Dictyostelium chemotactic responses were not present in current Acanthamoeba genome sequence data. The results of this study suggest that Acanthamoeba does not use chemotaxis as the primary mechanism to find bacterial food sources and that the chemotactic responses of Dictyostelium to bacteria may have co-evolved with chemotactic responses that facilitate multicellular development. Copyright © 2016 Elsevier GmbH. All rights reserved.

  14. Principales protagonistas de la respuesta inflamatoria a la infección

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    Juan Carlos Velázquez Acosta

    1998-06-01

    Full Text Available Se hace una revisión de los principales elementos implicados en la respuesta inflamatoria del individuo a la infección, por el beneficio que este conocimiento reporta al mejor manejo terapéutico de los pacientes. Se revisan los principales protagonistas de la inflamación, desde los detonantes como: lipopolisacárido, peptidoglicano, ácidos lipoteicoico y murámico, hasta los principales mediadores implicados. Se discute el proceso de activación de monocitos y células endoteliales y la repercusión de ello, y se hace un análisis dinámico del proceso de activación en función del tiempo trancurrido desde el comienzo de la infección, y sus etapas fisiopatológicas. Se evidencia el papel protagónico que tiene el propio organismo en el daño producido por la respuesta a la infección, además de la importancia del adecuado equilibrio entre proinflamación y contrarregulación para el pronóstico del enfermo, lo que obliga a tenerlo en cuenta a la hora del tratamiento.A review of the main elements involved in the inflamatory response of the individuals to infection is made, taking into account that this knowledge helps to improve the therapeutic management of patients. The main agents of inflammation are reviewed, starting from detonators such as: lipopolysaccharides, petpidoglycans, muramic acid to the principal mediators involved. The activation process of monocytes and endothelial cells is dicussed, as well as its repercussion. A dynamic analysis of the activation process according to the time elapsed since the onset of the infection and of its physiopathological stages is made. It is demonstrated the fundamental role played by the organism in the damage produced by the response to infection, and the importance of an adequate balance between proinflammation and contraregulation for the patient´s prognosis, which makes it necessary at the time of treatment.

  15. Cytopathic effect of Acanthamoeba on human corneal fibroblasts

    Science.gov (United States)

    Takaoka-Sugihara, Noriko; Yokoo, Seiichi; Matsubara, Masao; Yagita, Kenji

    2012-01-01

    Purpose Acanthamoeba keratitis is associated with keratocyte depletion in humans. We investigated how Acanthamoebae isolated from corneas affected by Acanthamoeba keratitis interacted with human corneal stromal cells in vitro. Methods Acanthamoebae were isolated from 6 patients with Acanthamoeba keratitis and genotyping was done. Whether the isolated Acanthamoebae could invade the corneal stroma was assessed with denuded corneal stroma ex vivo. The cytopathic effect of Acanthamoeba on cultured corneal fibroblasts from donor corneas was quantitatively evaluated by the MTT assay after culture under various conditions. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) and Annexin V staining were employed to detect apoptotic cells among the corneal fibroblasts co-cultured with Acanthamoebae. Results All 6 Acanthamoebae isolated from the patients with Acanthamoeba keratitis were shown to have the T4 genotype by 18S rDNA sequence analysis. Acanthamoebae invaded the denuded corneal stroma in the ex vivo experiments and had a cytopathic effect on human corneal fibroblasts after direct adhesion, but not via chemical mediators. A cytopathic effect was detected with all 6 Acanthamoebae and corneal fibroblasts mainly died by apoptosis, as evidenced by Annexin V staining. Conclusions Acanthamoebae isolated from patients with Acanthamoeba keratitis had a cytopathic effect on human corneal fibroblasts, mainly via induction of apoptosis after direct adhesion. Our findings may provide some clues to the pathophysiology of corneal keratocyte depletion in patients with Acanthamoeba keratitis. PMID:22933834

  16. Co-isolation of Vahlkampfia and acanthamoeba in acanthamoeba-like keratitis in a Spanish population.

    Science.gov (United States)

    Arnalich-Montiel, Francisco; Lorenzo-Morales, Jacob; Irigoyen, Cristina; Morcillo-Laiz, Rafael; López-Vélez, Rogelio; Muñoz-Negrete, Francisco; Piñero, Jose E; Valladares, Basilio

    2013-05-01

    To report the co-isolation incidence of Acanthamoeba and Vahlkampfia in amoebic keratitis from a tertiary care institution in Madrid, Spain. In this retrospective case series, 7 eyes of 7 consecutive patients with culture-proven or polymerase chain reaction-positive Acanthamoeba keratitis were seen at a tertiary care institution from January 2010 to April 2011, and their charts were reviewed. Two of 7 patients showed mixed Acanthamoeba and Vahlkampfia keratitis. Good clinical response to the treatment was strongly correlated with early diagnosis, whereas delayed diagnosis resulted in poor response to the treatment in single or mixed infection. Co-isolation of Vahlkampfia and Acanthamoeba in Acanthamoeba-like keratitis has recently been detected in our population. This finding should raise awareness of the existence of other amoeba different from Acanthamoeba causing keratitis. There are not enough cases yet to determine the impact of mixed amoebic keratitis in the prognosis of this disease.

  17. Quantitation by flow microfluorometry of total cellular DNA in Acanthamoeba

    Energy Technology Data Exchange (ETDEWEB)

    Coulson, P.B.; Tyndall, R.

    1978-01-01

    The DNA content of five speciea of Acanthamoeba was determined by flow microfluorometry. Acanthamoeba castellanii (AC-30), acanthamoeba polyphaga (APG and P-23), acanthamoeba rhysodes, acanthamoeba culbertsoni (A-1), and acanthamoeba royreba were grown in a casitone based medium 24 to 48 hr. The trophozoites were harvested, fixed in 70% ethanol (acidified), pretreated with RNase, stained with propidium diiodide, and evaluated for DNA-bound fluorescence. All species tested had DNA values between 2.0 to 5.0 pg/cell. These results placed DNA/cell values of Acanthamoeba slightly lower than DNA/cell values of other eucaryotic cells and much lower than Amoeba proteus values. These results indicate that FMF may be a useful adjunct in distinguishing Acanthamoeba cells from either eucaryotic cells or some other amoeba. However, differences in DNA/cell between species of Acanthamoeba are small and would not be useful in identification of species.

  18. Coexistent Acanthamoeba keratitis and herpetic keratitis.

    Science.gov (United States)

    Mathers, W D; Goldberg, M A; Sutphin, J E; Ditkoff, J W; Folberg, R

    1997-06-01

    To describe a series of patients with proved herpes simplex virus keratitis (herpetic keratitis) who also had documented Acanthamoeba keratitis. Herpetic keratitis was documented with viral cultures, immunologic stains, or histopathologic examination for multinucleated giant cells in the corneal epithelium. Acanthamoeba organisms were identified using confocal microscopy and epithelial biopsy with hematoxylin-eosin staining. Biopsy of the stroma and epithelium was used to identify Acanthamoeba organisms in 1 case. Cultures for herpes simplex virus were positive in 6 of the 9 cases. Immunologic stains were positive in an additional 2 cases, and in 1 case multinucleated giant cells were present in the epithelium consistent with the diagnosis of herpes simplex virus keratitis. Tandem scanning confocal microscopic findings were positive for Acanthamoeba in 8 of the 9 cases, and all of them demonstrated Acanthamoeba organisms in epithelial scrape biopsy specimens. In 1 case, which was not evaluated with confocal microscopy, Acanthamoeba was detected using a stromal and epithelial biopsy. Two of the 9 patients had a history of contact lens use. Acanthamoeba keratitis may be present as a secondary or opportunistic infection in patients with herpetic keratitis.

  19. Successful treatment of Acanthamoeba keratitis by hexamidine.

    Science.gov (United States)

    Brasseur, G; Favennec, L; Perrine, D; Chenu, J P; Brasseur, P

    1994-09-01

    Acanthamoeba keratitis remains very difficult to treat because of the lack of antiamoebic agents completely effective against cysts. Currently, the recommended treatment includes the use of topical neomycin sulfate, various imidazoles, and propamidine isethionate (Brolene) 0.1% eye drops, a compound of the diamidine family. In the present article, we describe the successful management of two patients with an Acanthamoeba keratitis, treated with hexamidine diisethionate (Desomedine) 0.1% eye drops, another diamidine derivative, which was found amoebicidal in vitro on the isolated Acanthamoeba strains. This is to our knowledge the first report on the amoebicidal effectiveness of hexamidine, simultaneously in vitro and in vivo.

  20. Acanthamoeba: ecology, pathogenicity and laboratory detection.

    Science.gov (United States)

    Walker, C W

    1996-06-01

    Acanthamoeba spp. are ubiquitous free-living protozoa found in a wide range of environmental niches. They are resistant to disinfectants, temperature variation and desiccation and are responsible for two recognised diseases in humans, granulomatous amoebic encephalitis and keratitis. Both infections are rare, although the latter is currently receiving more attention following the association between Acanthamoeba and the wearing of contact lenses. Laboratory diagnosis is unusual but not beyond the bounds of most routine clinical microbiology departments. In this review the various aspects surrounding the ecology, pathogenicity and laboratory detection of Acanthamoeba spp. are considered.

  1. Acanthamoeba keratitis with Curvularia co-infection.

    Science.gov (United States)

    Gupta, N; Samantaray, J C; Duggal, S; Srivastava, V; Dhull, C S; Chaudhary, U

    2010-01-01

    We report a case of Acanthamoeba keratitis with Curvularia co-infection. Acanthamoeba and fungal co-infection have been uncommonly reported in literature, worldwide. A classical history with a strong clinical suspicion and experienced laboratory personnel with systematic examination of corneal scrapings for bacterial, viral, parasitic and fungal causes are imperative for accurate diagnosis. Early diagnosis of Acanthamoeba keratitis or fungal infection followed by aggressive and appropriate treatment with effective agents is critical for the retention of good vision. Acanthamoeba keratitis is difficult to diagnose and, despite improvement in treatment options, may culminate in prolonged morbidity and significant loss of visual acuity. This case emphasizes the important role played by clinical microbiologists in making prompt diagnosis which can ultimately reduce visual morbidity.

  2. Acanthamoeba keratitis with Curvularia co-infection

    Directory of Open Access Journals (Sweden)

    Gupta N

    2010-01-01

    Full Text Available We report a case of Acanthamoeba keratitis with Curvularia co-infection. Acanthamoeba and fungal co-infection have been uncommonly reported in literature, worldwide. A classical history with a strong clinical suspicion and experienced laboratory personnel with systematic examination of corneal scrapings for bacterial, viral, parasitic and fungal causes are imperative for accurate diagnosis. Early diagnosis of Acanthamoeba keratitis or fungal infection followed by aggressive and appropriate treatment with effective agents is critical for the retention of good vision. Acanthamoeba keratitis is difficult to diagnose and, despite improvement in treatment options, may culminate in prolonged morbidity and significant loss of visual acuity. This case emphasizes the important role played by clinical microbiologists in making prompt diagnosis which can ultimately reduce visual morbidity.

  3. Caracterización de la respuesta inflamatoria en la neumonía comunitaria grave. Efecto de los corticoides en la contención de dicha respuesta y en el curso evolutivo de la infección

    OpenAIRE

    Fernández Serrano, Silvia

    2012-01-01

    [spa] La neumonía adquirida en la comunidad (NAC) continúa siendo en la actualidad una enfermedad potencialmente grave, que con frecuencia presenta una evolución desfavorable, a pesar del tratamiento antibiótico adecuado. La hipótesis de la tesis plantea que es posible monitorizar la respuesta inflamatoria que tiene lugar durante la NAC y, que dicha respuesta, puede ser influenciada por los antibióticos utilizados en su tratamiento, así como modulada mediante una terapia adyuvante con co...

  4. Isolation and genotyping of Acanthamoeba spp. from Acanthamoeba meningitis/ meningoencephalitis (AME) patients in India.

    Science.gov (United States)

    Behera, Himanshu Sekhar; Satpathy, Gita; Tripathi, Manjari

    2016-08-09

    Acanthamoeba spp. are free-living ubiquitous protozoans capable of causing Acanthamoeba meningitis/meningoencephalitis (AME) of the central nervous system in humans. Acanthamoeba spp. are divided into 20 different genotypes (T1-T20) on the basis of variation in nucleotide sequences of the 18S rRNA gene. The objective of this study was to identify the genotypes of Acanthamoeba spp. in patients of Acanthamoeba meningitis/meningoencephalitis (AME) using 18S rRNA gene-based PCR assay. The present study provides information regarding the involvement of the most prevalent and predominant genotype of Acanthamoeba spp. in Acanthamoeba meningitis/meningoencephalitis infections in India. Cerebrospinal fluid (CSF) was collected from 149 clinically suspected Acanthamoeba meningitis/meningoencephalitis (AME) patients reporting to the outpatient department/causality services of the Neurosciences Centre, AIIMS, New Delhi, India during the past five years. Samples were inoculated onto 2 % non-nutrient agar plates overlaid with E. coli and incubated at 30 °C for 14 days. Among 149 suspected patients, ten were found culture-positive for Acanthamoeba spp. out of which six isolates were established in axenic culture for molecular analysis. DNA was isolated and a PCR assay was performed for amplification of the Diagnostic fragment 3 (DF3) (~280 bp) region of the 18S rRNA gene from axenic culture of six Acanthamoeba spp. isolates. Rns genotyping was performed on the basis of the variation in nucleotide sequences of DF3 region of the 18S rRNA gene. In the phylogenetic analysis, all of the six Acanthamoeba spp. isolates were found to belong to genotype T4. The sequence homology search for these six isolates in the NCBI databank showed homology with the available strains of Acanthamoeba spp. The newly generated sequences are available in the GenBank database under accession numbers KT004416-KT004421. In the present study, genotype T4 was found as the most prevalent and

  5. Unexpected postmortem diagnosis of acanthamoeba meningoencephalitis in an immunocompetent child

    OpenAIRE

    Binesh, Fariba; Karimi, Mehran; Navabii, Hossein

    2011-01-01

    Meningoencephalitis caused by Acanthamoeba spp. is a rare opportunistic infection, difficult to diagnose and treat, which causes death in almost all cases. Here, the authors report a 5-year-old Iranian immunocompetent girl who died of fulminant acanthamoeba meningoencephalitis. To the authors’ knowledge, this is the first case of acanthamoeba meningoencephalitis in Iran.

  6. An improvised medium for axenic cultivation of Acanthamoeba spp.

    OpenAIRE

    Kirti Megha; Amit Gupta; Rakesh Sehgal; Sumeeta Khurana

    2017-01-01

    Acanthamoebae can be easily grown in bacterised cultures, but their growth in axenic media is tedious and many times unsuccessful. We thus experimented with some additives in the conventional axenic medium for growth of various isolates of Acanthamoeba. Addition of Torula yeast RNA was found to significantly enhance the growth of Acanthamoebae in the axenic culture medium.

  7. An improvised medium for axenic cultivation of Acanthamoeba spp.

    Directory of Open Access Journals (Sweden)

    Kirti Megha

    2017-01-01

    Full Text Available Acanthamoebae can be easily grown in bacterised cultures, but their growth in axenic media is tedious and many times unsuccessful. We thus experimented with some additives in the conventional axenic medium for growth of various isolates of Acanthamoeba. Addition of Torula yeast RNA was found to significantly enhance the growth of Acanthamoebae in the axenic culture medium.

  8. FACTOR NUCLEAR kB (NF-kB: SIGNALOSOMA Y SU IMPORTANCIA EN ENFERMEDADES INFLAMATORIAS Y CÁNCER

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    Nancy P. Echeverry R.L

    2008-04-01

    Full Text Available El factor nuclear kB (NF-kB es un dímero constituido por proteínas de la familia Rel. El NF-kB se encuentra en el citoplasma unido a proteínas inhibidoras (IkB. Las IkB son fosforiladas por diferentes cinasas que hacen parte del signalosoma como las cinasas de IKKa e IKKb y el modulador esencial de NF-kB (NEMO, la proteína cinasa activadora de mitosis (MAPK o p38 y la cinasa inductora de NF-kB (NIK. Estas cinasas al ser activadas por señales dependientes de citocinas y luz ultravioleta, fosforilan las IkB provocando su ubiquitinación, su degradación por proteosoma y la subsecuente liberación y translocación al núcleo de NF-kB. Recientemente se le ha dado una gran importancia al NF-kB en la vía de señalización desencadenada por estrés oxidativo, estrés genotóxico y daño en el DNA. A diferencia de la vía denominada clásica, en esta ruta ocurre una SUMOilación de NEMO y translocación al núcleo. En el núcleo NEMO interactúa con la proteína de la ataxia telangiectasia mutada (ATM activada en respuesta a modificaciones en la cromatina y daño en el DNA. El complejo ATM/NEMO es translocado al citoplasma donde la ATM fosforila a las IKK llevando a la ubiquitinación y posterior liberación de NF-kB que es translocado al núcleo. NF-kB desencadena procesos de supervivencia incluyendo el aumento de la transcripción de enzimas antioxidantes como la superóxido dismutasa, catalasa y glutatión. Estas enzimas participan en el control de los niveles de especies reactivas de oxígeno en la célula. La sobreactivación de NF-kB se relaciona con inflamación y cáncer. En la actualidad se desarrolla una búsqueda de fármacos que actúen sobre moléculas del signalosoma de NF-kB, no sólo para el manejo de enfermedades inflamatorias sino también para el uso durante el tratamiento de tumores resistentes a radio y quimioterapia.

  9. Diagnosis of Acanthamoeba keratitis in vivo with confocal microscopy.

    Science.gov (United States)

    Winchester, K; Mathers, W D; Sutphin, J E; Daley, T E

    1995-01-01

    We present eight cases of Acanthamoeba keratitis. In each case; the Acanthamoeba organisms were visualized in the epithelium and anterior stroma using tandem scanning confocal microscopy. The organisms were highly reflective, ovoid, and were 10-25 microns in diameter. The Acanthamoeba organisms in the human corneas were identical in size and shape to Acanthamoeba organisms on an agar plate visualized with the same confocal microscope. Confocal microscopy is a useful method for identifying Acanthamoeba organisms in vivo within the corneal epithelium and anterior stroma.

  10. Tigecycline inhibits proliferation of Acanthamoeba castellanii.

    Science.gov (United States)

    Jha, Bijay Kumar; Seo, Incheol; Kong, Hyun-Hee; Suh, Seong-Il; Suh, Min-Ho; Baek, Won-Ki

    2015-03-01

    Acanthamoeba is an opportunistic protozoan parasite responsible for different diseases in humans, such as granulomatous amoebic encephalitis and amoebic keratitis. Tigecycline, a third-generation tetracycline antibiotic, has potential activity to treat most of the antibiotic resistant bacterial infections. The effects of tigecycline in eukaryotic cells as well as parasites are less well studied. In the present study, we tested the effects of tigecycline on trophozoites of Acanthamoeba castellanii. The inhibitory effect of tigecycline on Acanthamoeba was determined by resazurin reduction and trypan blue exclusion assays. We found that tigecycline significantly inhibited the growth of Acanthamoeba (46.4 % inhibition at the concentration of 100 μM) without affecting cell viability and induction of encystation, whereas other tetracycline groups of antibiotics such as tetracycline and doxycycline showed no inhibitory effects. Furthermore, tigecycline decreased cellular adenosine triphosphate (ATP) level by 26 % than the control and increased mitochondrial mass, suggesting mitochondrial dysfunction in tigecycline-treated cells. These findings suggest that mitochondrial dysfunction with decreased ATP production might play an important mechanism of tigecycline in suppression of Acanthamoeba proliferation.

  11. Laboratory diagnosis of Acanthamoeba keratitis in Hungary.

    Science.gov (United States)

    Orosz, Erika; Farkas, Ágnes; Kucsera, István

    2016-09-01

    Acanthamoeba species are free-living amebae that can be found in almost every range of environments. Within this genus, numerous species are recognized as human pathogens, potentially causing Acanthamoeba keratitis (AK). AK is a corneal disease that is predominantly associated with contact lens use, the epidemiology of which is related to the specific genotype of Acanthamoeba. This study reports seven (7/16; 43.75%) positive cases. Detection of Acanthamoeba in corneal scrapings is based on cultivation and polymerase chain reaction (PCR) combined with the molecular taxonomic identification method. By PCR, seven samples were positive; cultivation was successful for five samples, probably because of the low quantity of samples. Genotype identification was carried out with a real-time fluorescence resonance energy transfer PCR assay based on sequence analysis of the 18S rRNA gene, and sensitivity and specificity were evaluated in comparison with traditional parasitological techniques. All seven detected Acanthamoeba strains belonged to the T4 genotype, the main AK-related genotype worldwide. These results confirmed the importance of a complete diagnostic protocol, including a PCR assay, for the clinical diagnosis of AK from human samples. Genotyping allowed the identification of all isolates in the T4 group, thus demonstrating the prevalence of this genotype in Hungary.

  12. Niveles de biológicos: eficacia e inmunogenicidad del tratamiento para enfermedad inflamatoria intestinal

    OpenAIRE

    Ceballos Santos, Daniel

    2016-01-01

    Programa de doctorado: Avances en Medicina Interna. La fecha de publicación es la fecha de lectura [ES]INTRODUCCIÓN: La monitorización de infliximab (IFX) y adalimumab (ADA) para el control de la actividad de la enfermedad inflamatoria intestinal (EII) y la optimización del tratamiento no está estandarizada, aunque los datos publicados hasta el momento sugieren que tienen una implicación relevante en los resultados de la terapia. Los niveles de biológicos y anticuerpos anti-biológicos pued...

  13. Enfermedades auto inflamatorias (EAI en pediatría

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    Hernández S. Pamela, Dra.

    2012-07-01

    Full Text Available Las enfermedades autoinmunes son un grupo de enfermedades de relativo reciente conocimiento. Muchas de ellas están genéticamente determinadas (excepto el síndrome de PFAPA. Se caracterizan por episodios recurrentes de fiebre asociada a síntomas que generalmente pueden comprometer la piel, sistema músculo esquelético y gastrointestinal. A pesar de su baja prevalencia, el descubrimiento de los genes comprometidos en algunas de ella, ha permitido una mejor comprensión de los mecanismos de la respuesta inmune innata y en especial del rol de los llamados inflamosomas. Estos avances han permitido terapias más específicas, lo que ha llevado a disminuir en forma importante la morbilidad asociada, tanto a corto como a largo plazo. En el área pediátrica, el síndrome de PFAPA debe ser incluido como alternativa en el diagnóstico diferencial.

  14. Genotyping of Acanthamoeba T15: the environmental strain in Turkey.

    Science.gov (United States)

    Evyapan, Gulsah; Koltas, Ismail S; Eroglu, Fadime

    2015-03-01

    Environmental sources are potential sources for the transmission of Acanthamoeba in humans and other mammals. A total of 50 water samples from hot springs and swimming pools, and 50 soil samples were taken from Adana, Afyon, Kutahya, Mersin and Nigde provinces in Turkey. Samples were analysed using 18S rRNA-DNA sequencing. Acanthamoeba griffini (T3), Acanthamoeba castellanii (T4) and Acanthamoeba jacobsi (T15) were found in water samples. Acanthamoeba griffini (T3) and Acanthamoeba castellanii (T4) were detected in soil samples. In Turkey, this was the first time that Acanthamoeba jacobsi (T15) was detected in water samples. © The Author 2014. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  15. CORIOAMNIONITIS HISTOLÓGICA Y MORBIMORTALIDAD NEONATAL: APROXIMACIÓN AL SÍNDROME DE RESPUESTA INFLAMATORIA FETAL

    OpenAIRE

    Rincón Ricote,M. Inmaculada; Magdaleno Dans,Fernando; Sancha Naranjo,Marta; Omeñaca Teres,Félix; González González,Antonio

    2010-01-01

    Antecedentes: El síndrome de respuesta inflamatoria fetal (SRIF) es una entidad relacionada con la presencia de inflamación intrauterina y suele asociarse a infección intraamniótica. Su consecuencia más grave es la lesión cerebral y posterior desarrollo de parálisis cerebral. Objetivo: Evaluar la relación entre el síndrome de respuesta inflamatoria fetal y el desarrollo de complicaciones neonatales. Método: Estudio descriptivo y retrospectivo, realizado en el Hospital Universitario La Paz de ...

  16. Acanthamoeba keratitis challenges a case report.

    Science.gov (United States)

    Cristina, Stan; Cristina, Vlăduţiu; Mihaela, Popovici

    2016-01-01

    Acanthamoeba keratitis is a rare, chronic, mainly contact lens-related infection caused by a free-living amoeba found ubiquitously in water and soil. A case of a 9-year-old child, who presented to our clinic with painful, red left eye, associated with photophobia, and decreased visual acuity, wais reported. The clinical examination revealed a discoid opacity inferiorly bounded by a dense, gray infiltrate. The progressive nature of the corneal infiltrate, the epithelial defect, and the lack of response to treatment was highly suggestive for Acanthamoeba keratitis. The distinctiveness of this case was the presence of Acanthamoeba keratitis in a child without a history of trauma or contact lens usage, the lack of an appropriate diagnosis and management of this vision-threatening infection.

  17. Sepsis por shigella flexneri

    Directory of Open Access Journals (Sweden)

    César Cabrera C

    2005-04-01

    Full Text Available Se presenta un caso raro de sepsis por Shigella flexneri en una paciente de 45 años de edad quien estando hospitalizada para el estudio de un tumor cerebral, requirió el uso de manitol y dosis altas de corticoides; luego de ello presenta deposiciones líquidas con moco y sangre, desarrolla síndrome de respuesta inflamatoria sistémica, luego se aísla Shigella flexneri en el hemocultivo; recibió tratamiento antibiótico con ciprofloxacina. Se describen las características del caso y se comenta de acuerdo con la revisión de literatura.

  18. Genotypic Identification of Acanthamoeba sp. Isolates Associated with an Outbreak of Acanthamoeba keratitis (AK)

    Science.gov (United States)

    Booton, Gregory C.; Joslin, Charlotte E.; Shoff, Megan; Tu, Elmer Y.; Kelly, Daryl J.; Fuerst, Paul A.

    2009-01-01

    Purpose Significant increases in Acanthamoeba keratitis (AK) cases have been observed in the Chicago-Gary-Kenosha area since June, 2003. It was hypothesized that increased rates of AK infections may be due to changes resulting from changes in municipal water treatment, or, alternatively, a more pathogenic strain of Acanthamoeba may be responsible. Methods Previous sequence analysis of the 18S rDNA of Acanthamoeba isolates resulted in the identification of 15 different genotypic classes. These analyses indicate AK cases are predominantly associated (~97%) with a single genotype (designated T4) of Acanthamoeba, and rarely with other genotypes (eg., T3 and T11). In this study we test the hypothesis that a new or more pathogenic genotype of Acanthamoeba is the cause of the recent surge in AK. Results We determined the genotype of 15 Acanthamoeba sp. isolates from AK cases from this outbreak using sequence analysis of a region of the 18S rDNA. Our results indicate that these isolates are predominantly genotype T4 (87%), with the remaining isolates being genotype T3 (13%). Both genotypes have previously been observed in AK cases. Conclusion There is no support for the hypothesis that the current AK outbreak is associated with infection by a new, more pathogenic, Acanthamoeba genotype. In addition, these results offer support for the hypothesis that the increased AK incidence may be due to changes in water treatment protocols leading to increased bacterial colonization of the water supply, and subsequent increases of already present Acanthamoeba sp, ultimately culminating in an increase of AK cases. PMID:19512903

  19. Arcobacter butzleri survives within trophozoite of Acanthamoeba castellanii.

    Science.gov (United States)

    Villanueva, María P; Medina, Gustavo; Fernández, Heriberto

    2016-01-01

    The survival of three Arcobacter butzleri strains inside Acanthamoeba castellanii was assessed using axenic cultures of A. castellanii that were inoculated with the tested strains and incubated at 26°C under aerobic conditions for 240h. The behavior of bacteria in contact with amoebae was monitored using phase contrast microscopy. The bacterial survival rate within amoebae was assessed through counting colony forming units, using the gentamicin protection assay. All A. butzleri strains were able to survive during 240h within the amoebae, thus suggesting that (i) A. butzleri resists the amoebic digestion processes at least for the analyzed time; (ii) that A. castellanii could serve as an environmental reservoir for this bacterium, probably acting as a transmission vehicle for A. butzleri. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  20. Autophagy inhibitors as a potential antiamoebic treatment for Acanthamoeba keratitis.

    Science.gov (United States)

    Moon, Eun-Kyung; Kim, So-Hee; Hong, Yeonchul; Chung, Dong-Il; Goo, Youn-Kyoung; Kong, Hyun-Hee

    2015-07-01

    Acanthamoeba cysts are resistant to extreme physical and chemical conditions. Autophagy is an essential pathway for encystation of Acanthamoeba cells. To evaluate the possibility of an autophagic Acanthamoeba encystation mechanism, we evaluated autophagy inhibitors, such as 3-methyladenine (3MA), LY294002, wortmannin, bafilomycin A, and chloroquine. Among these autophagy inhibitors, the use of 3MA and chloroquine showed a significant reduction in the encystation ratio in Acanthamoeba cells. Wortmannin also inhibited the formation of mature cysts, while LY294002 and bafilomycin A did not affect the encystation of Acanthamoeba cells. Transmission electron microscopy revealed that 3MA and wortmannin inhibited autophagy formation and that chloroquine interfered with the formation of autolysosomes. Inhibition of autophagy or autolysosome formation resulted in a significant block in the encystation in Acanthamoeba cells. Clinical treatment with 0.02% polyhexamethylene biguanide (PHMB) showed high cytopathic effects on Acanthamoeba trophozoites and cysts; however, it also revealed high cytopathic effects on human corneal epithelial cells. In this study, we investigated effects of the combination of a low (0.00125%) concentration of PHMB with each of the autophagy inhibitors 3MA, wortmannin, and chloroquine on Acanthamoeba and human corneal epithelial cells. These new combination treatments showed low cytopathic effects on human corneal cells and high cytopathic effects on Acanthamoeba cells. Taken together, these results provide fundamental information for optimizing the treatment of Acanthamoeba keratitis. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  1. Genotyping of Acanthamoeba isolates and clinical characteristics of patients with Acanthamoeba keratitis in China.

    Science.gov (United States)

    Zhao, Ge; Sun, Shiying; Zhao, Jing; Xie, Lixin

    2010-04-01

    Acanthamoeba keratitis (AK) is a sight-threatening corneal infection, the epidemiology of which is related to the specific genotype of Acanthamoeba. In this study, the genotypes of 14 Acanthamoeba isolates, each from a patient with AK, were identified according to the highly variable DF3 region in the 18S rRNA gene at Shandong Eye Institute, PR China, from 2000 to 2009, and the clinical characteristics of these patients were analysed. All 14 amoebae were genotype T4, representing nine different DF3 sequence types, seven of which were newly identified. Cornea infestation was the main risk factor for these 14 AK patients. Amoebic cysts could be detected in all corneal scrapes. Corneal ulcers were located mainly at the corneal centre, accompanied by eye pain, and some appeared with a Wessely ring. Surgery was carried out on all patients. Acanthamoeba genotypes T4/26 and T4/27 were found to cause a more severe keratitis, whilst the others showed no significant differences in clinical characteristics. In conclusion, the majority of the keratitis-causing Acanthamoeba isolates were genotype T4, with Acanthamoeba genotypes T4/26 and T4/27 from PR China causing a more severe keratitis.

  2. Experimental Acanthamoeba keratitis: II. Immunohistochemical evaluation.

    Science.gov (United States)

    Larkin, D. F.; Easty, D. L.

    1991-01-01

    In a Wistar rat experimental model of Acanthamoeba keratitis immunohistochemical techniques were used to analyse the host cellular response. The inflammatory cell profile was observed to change at intervals. In tissue sections the cellular response consisted of neutrophils on the first day but predominantly macrophages on the following days. Some T lymphocytes but no B lymphocytes were observed. Images PMID:1854696

  3. Acanthamoeba keratitis in Sudan: outcome of ketoconazole ...

    African Journals Online (AJOL)

    In an exploration of the acanthamoebic aetiology of chronic keratitis cases (not responding to antibiotics, antiviral or antifungal therapy), 138 Sudanese patients were seen over a 2-year period at two teaching eye hospitals in Khartoum State. Six (4.3%) of these patients were found to be suffering from Acanthamoeba ...

  4. Twenty Years of Acanthamoeba Diagnostics in Austria

    Science.gov (United States)

    Walochnik, Julia; Scheikl, Ute; Haller-Schober, Eva-Maria

    2015-01-01

    Acanthamoebae are the causative agents of an often seriously progressing keratitis (AK) occurring predominantly in contact lens wearers and can cause several disseminating infections potentially resulting in granulomatous amoebic encephalitis (GAE) in the immunocompromised host. Our institution is the Austrian reference laboratory for Acanthamoeba diagnostics and the aim of this study was to give an overview of proven cases of Acanthamoeba infections in Austria during the past 20 yr. All samples of patients with suspected AK or GAE were screened for Acanthamoeba spp. by culture and/or PCR and the detected amoebae were genotyped. Altogether, 154 cases of AK and three cases of GAE were diagnosed. Age of the AK patients ranged from 8 to 82 yr (mean 37.8) and 58% of the patients were female. Approximately 89% of the AK patients were contact lens wearers, almost all cases were unilateral and 19% of the patients required a keratoplasty. Age of the GAE patients ranged from 2 to 25 yr (mean 14.7), all were HIV-negative, but two were severely immunosuppressed at the time of diagnosis. The predominant genotype in the AK cases was T4, other genotypes found were T3, T5, T6, T10 and T11. The three GAE cases involved genotypes T2, T4 and T5. PMID:25047131

  5. Caspase-like proteins: Acanthamoeba castellanii metacaspase

    Indian Academy of Sciences (India)

    2014-10-20

    Oct 20, 2014 ... will provide insight into their potential for treatment therapies against Acanthamoeba infection and other similar parasitic protozoan. Additionally ..... tem infection that occurs in patients with acquired immune deficiency syndrome and that ..... mold from decaying forest leaves. J. Agric. Res. 50 135–147.

  6. Twenty years of acanthamoeba diagnostics in Austria.

    Science.gov (United States)

    Walochnik, Julia; Scheikl, Ute; Haller-Schober, Eva-Maria

    2015-01-01

    Acanthamoebae are the causative agents of an often seriously progressing keratitis (AK) occurring predominantly in contact lens wearers and can cause several disseminating infections potentially resulting in granulomatous amoebic encephalitis (GAE) in the immunocompromised host. Our institution is the Austrian reference laboratory for Acanthamoeba diagnostics and the aim of this study was to give an overview of proven cases of Acanthamoeba infections in Austria during the past 20 yr. All samples of patients with suspected AK or GAE were screened for Acanthamoeba spp. by culture and/or PCR and the detected amoebae were genotyped. Altogether, 154 cases of AK and three cases of GAE were diagnosed. Age of the AK patients ranged from 8 to 82 yr (mean 37.8) and 58% of the patients were female. Approximately 89% of the AK patients were contact lens wearers, almost all cases were unilateral and 19% of the patients required a keratoplasty. Age of the GAE patients ranged from 2 to 25 yr (mean 14.7), all were HIV-negative, but two were severely immunosuppressed at the time of diagnosis. The predominant genotype in the AK cases was T4, other genotypes found were T3, T5, T6, T10 and T11. The three GAE cases involved genotypes T2, T4 and T5. © 2014 The Authors. The Journal of Eukaryotic Microbiology published by Wiley Periodicals, Inc. on behalf of International Society of Protistologists.

  7. Painless Acanthamoeba Keratitis with Normal Vision.

    Science.gov (United States)

    Kwok, Pui Wai Rachel; Kam, Ka Wai; Jhanji, Vishal; Young, Alvin L

    2017-03-01

    To report an atypical case of contact lens-related Acanthamoeba keratitis. A 15-year-old secondary school female student with a history of soft contact lens wear was referred to our hospital by a private general practitioner for management of right eye redness and discomfort for 2 weeks. Upon examination, the best-corrected visual acuity was 20/20 and 20/16 for her right and left eyes, respectively. There was diffuse radial keratoneuritis noted in the cornea of her right eye without any associated epithelial defect. Corneal scraping was performed to induce epithelial defect over the keratoneuritis area, and it was positive for Acanthamoeba trophozoites. She was treated with amoebicidal therapy consisting of propamidine isethionate 0.1% and polyhexamethylene biguanide 0.02%, for 6 months. The patient did not complain of any ocular pain in the entire course of her disease. She attained a final visual acuity of 20/13 in the affected eye with residual peripheral radial perineuritic scar. Atypical presentation of Acanthamoeba infection is uncommon. This case should arouse the awareness of an indolent presentation of this potentially sight-threatening disease. Clinicians should have a high level of suspicion in contact lens users who present with corneal abnormalities despite an absence of pain. Microbiological work-up and prompt treatment led to a complete resolution of Acanthamoeba infection in our patient.

  8. Acanthamoeba keratitis in South India: a longitudinal analysis of epidemics.

    Science.gov (United States)

    Lalitha, Prajna; Lin, Charles C; Srinivasan, Muthiah; Mascarenhas, Jeena; Prajna, N Venkatesh; Keenan, Jeremy D; McLeod, Stephen D; Acharya, Nisha R; Lietman, Thomas M; Porco, Travis C

    2012-04-01

    In light of the increased incidence of contact lens associated Acanthamoeba keratitis in recent years, this study analyzed longitudinal trends of its incidence among predominantly non-contact lens wearers in a high-volume referral center in South India. A retrospective analysis of microbiology laboratory records at the Aravind Eye Hospital from 1988-2009 was performed. The Maximum Excess Events Test (MEET) was used to identify epidemics of Acanthamoeba keratitis. There were a total of 38,529 unique cases of infectious keratitis evaluated over this time period, of which 372 were culture-positive for Acanthamoeba. Only three cases (0.9%) of Acanthamoeba keratitis occurred among contact lens wearers. MEET identified unique Acanthamoeba keratitis epidemics in 1993 and 2002. Discrete epidemics of Acanthamoeba keratitis occurred among a rural, non-contact lens wearing, population in South India in 1993 and 2002.

  9. The Value of Cytology Smears for Acanthamoeba Keratitis

    Directory of Open Access Journals (Sweden)

    Sangita P. Patel

    2016-01-01

    Full Text Available Purpose. Acanthamoeba keratitis remains a difficult diagnosis despite advances in genetic and imaging technologies. The purpose of this paper is to highlight the utility of cytology smears for diagnosis of Acanthamoeba keratitis. Methods. This is a case study of the diagnostic course for a patient with suspected Acanthamoeba keratitis. Results. A 40-year-old male with poor contact lens hygiene presented with severe left eye pain. Slit lamp examination showed two peripheral ring infiltrates without an epithelial defect. The epithelium over both infiltrates was removed with a Kimura spatula. Half of the sample was smeared on a dry microscope slide and the other half was submitted for Acanthamoeba culture and PCR. Both culture and PCR were negative for Acanthamoeba, but hematoxylin and eosin stain of the smear revealed double-walled cysts. Conclusion. H&E staining of corneal cytology specimens is an efficient and readily available test for diagnosis of Acanthamoeba keratitis.

  10. Medical interventions for acanthamoeba keratitis

    Science.gov (United States)

    Alkharashi, Majed; Lindsley, Kristina; Law, Hua Andrew; Sikder, Shameema

    2016-01-01

    Background Acanthamoeba are microscopic, free-living, single-celled organisms which can infect the eye and lead to Acanthamoeba keratitis (AK). AK can result in loss of vision in the infected eye or loss of eye itself; however, there are no formal guidelines or standards of care for the treatment of AK. Objectives To evaluate the relative effectiveness and safety of medical therapy for the treatment of AK. Search methods We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2015, Issue 1), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to January 2015), EMBASE (January 1980 to January 2015), PubMed (1948 to January 2015), Latin American and Caribbean Health Sciences Literature Database (LILACS) (1982 to January 2015), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic search for trials. We last searched the electronic databases on 9 January 2015. Selection criteria We included randomized controlled trials (RCTs) of medical therapy for AK, regardless of the participants' age, sex, or etiology of disease. We included studies that compared either anti-amoeba therapy (drugs used alone or in combination with other medical therapies) with no anti-amoeba therapy or one anti-amoeba therapy with another anti-amoeba therapy. Data collection and analysis Two authors independently screened search results and full-text reports, assessed risk of bias, and abstracted data. We used standard methodological procedures as set forth by the Cochrane Collaboration. Main results We included one RCT (56 eyes of 55 participants) in this review. The study compared two types of topical biguanides for the treatment of AK

  11. Investigation of the Role of Bacteria in the Development of Acanthamoeba Keratitis.

    Science.gov (United States)

    Nakagawa, Hayate; Hattori, Takaaki; Koike, Naohito; Ehara, Tomoko; Fujita, Koji; Takahashi, Hiroki; Kumakura, Shigeto; Kuroda, Masahiko; Matsumoto, Tetsuya; Goto, Hiroshi

    2015-10-01

    Recently, much interest has been shown in bacteria extracted from Acanthamoeba strains isolated from patients with Acanthamoeba keratitis (AK). We hypothesized that the bacteria in Acanthamoeba strains may be a contributing factor in the development of AK. To prove this hypothesis, we investigated the involvement of bacteria harbored by Acanthamoeba in causing progressive ocular infection in rabbit corneas. One Acanthamoeba strain (T4 genotype) that harbored bacteria was isolated from a patient with AK. The Acanthamoeba strain pretreated or not pretreated with levofloxacin (LVFX) was inoculated into rabbit corneas. We also tested the effect of LVFX eye drops on keratitis induced by the Acanthamoeba strain. The infected rabbit eyes were evaluated for clinical scores, Acanthamoeba 18S rDNA and bacterial 16S rDNA numbers were analyzed by the real-time polymerase chain reaction, and the presence of Acanthamoeba was analyzed by histological examination. Inoculation of nonpretreated Acanthamoeba resulted in severe keratitis. In contrast, inoculation of LVFX-pretreated Acanthamoeba did not induce keratitis (mean clinical score, 17.3 vs. 2.3; P Acanthamoeba followed by topical LVFX therapy developed severe keratitis. In corneas inoculated with nonpretreated Acanthamoeba followed by LVFX therapy, the number of Acanthamoeba 18S rDNA copies was significantly higher than in other groups (P Acanthamoeba cysts were detected by Fungiflora Y staining only in corneas inoculated with nonpretreated Acanthamoeba followed by LVFX therapy. These results suggest that the presence of bacteria in Acanthamoeba may be required for the development of AK.

  12. Anaerobic Metabolism in T4 Acanthamoeba Genotype.

    Science.gov (United States)

    Alves, Daniella de Sousa Mendes Moreira; Alves, Luciano Moreira; da Costa, Tatiane Luiza; de Castro, Ana Maria; Vinaud, Marina Clare

    2017-06-01

    Members of the genus Acanthamoeba are of the most common protozoa that has been isolated from a variety of environment and affect immunocompromised individuals, causing granulomatous amoebic encephalitis and skin lesions. Acanthamoeba, in immunocompetent patients, may cause a keratitis related to corneal microtrauma. These free-living amoebas easily adapt to the host environment and wield metabolic pathways such as the energetic and respiratory ones in order to maintain viability for long periods. The energetic metabolism of cysts and trophozoites remains mostly unknown. There are a few reports on the energetic metabolism of these organisms as they are mitochondriate eukaryotes and some studies under aerobic conditions showing that Acanthamoeba hydrolyzes glucose into pyruvate via glycolysis. The aim of this study was to detect the energetic metabolic pathways with emphasis on anaerobic metabolism in trophozoites of three isolates of Acanthamoeba sp belonging to the T4 genotype. Two samples were collected in the environment and one was a clinical sample. The evaluation of these microorganisms proceeded as follows: rupture of trophozoites (7.5 × 10 3 parasites/ml) and biochemical analysis with high performance liquid chromatography and spectrophotometry. The anaerobic glycolysis was identified through the detection of glucose, pyruvate, and lactate. The protein catabolism was identified through the detection of fumarate, urea, and creatinine. The fatty acid oxidation was identified through the detection of acetate, beta-hydroxybutyrate, and propionate. The detected substances are the result of the consumption of energy reserves such as glycogen and lipids. The anaerobic glycolysis and protein catabolism pathways were observed in all three isolates: one clinical and two environmental. This study represents the first report of energetic pathways used by trophozoites from different isolates of the T4 genotype Acanthamoeba.

  13. Adhesion of Acanthamoeba on Silicone Hydrogel Contact Lenses.

    Science.gov (United States)

    Lee, Ga-Hyun; Lee, Ji-Eun; Park, Mi-Kyung; Yu, Hak-Sun

    2016-05-01

    To evaluate adhesion of Acanthamoeba trophozoites to different silicone hydrogel contact lens (SHCL) generations with and without multipurpose contact lens care solution (MPS) treatment. Acanthamoeba lugdunensis L3a trophozoites were inoculated onto discs trimmed from SHCLs: first generation, Air Optix (Lotrafilcon B) with a plasma surface treatment, second generation, Acuvue Oasys (Senofilcon A), which contains an internal wetting agent (Hydraclear), and third generation, Biofinity (Comfilcon A) with no surface treatment. After 18-hour inoculation, the number of adherent trophozoites on SHCLs was counted as the control under phase contrast microscopy. The effects of the 3 different MPSs, Opti-Free Express, ReNu Fresh, and Biotrue, soaking SHCLs for 6 hours, on Acanthamoeba adhesion were analyzed. Scanning electron microscopic examination was performed for assessment of Acanthamoeba attached on the lens surface. Acanthamoeba trophozoites showed greater adhesion to Air Optix than to Acuvue Oasys and Biofinity (P Acanthamoeba was significantly reduced compared with the control after treatment with Opti-Free Express (P 0.05). Acanthamoeba did not adhere to Biofinity regardless of MPSs treatment. Attachment of the acanthopodia of Acanthamoeba on the curved ridge of the Air Optix lens surface was observed. Acanthamoeba showed greater affinity for the first-generation SHCL and seemed to be more attached on SHCLs with more ridges. MPS with myristamidopropyl dimethylamine reduced the adhesion rate.

  14. Acanthamoeba species in Swimming Pools of Cairo, Egypt.

    Directory of Open Access Journals (Sweden)

    Ahmad Al-Herrawy

    2014-06-01

    Full Text Available The free-living amoebae Acanthamoeba spp. have been recognized as etiologic agents of amoebic encephalitis, keratitis, otitis, lung lesions and other skin infections mainly in immuno-compromised individuals. The purpose of this study is to detect the presence of Acanthamoeba in swimming pools in Egypt using a polymerase chain reaction (PCR method.Water samples were collected from 10 different swimming pools in Cairo, Egypt. Samples were cultured on non-nutrient agar for the detection of Acanthamoeba isolates that were confirmed by PCR amplification using genus specific primers. The molecularly confirmed Acanthamoeba isolates were morphologically identified to the species level.Members of genus Acanthamoeba were detected in 49.2% of the examined swimming-pool water samples. Morphologically, six Acanthamoeba species were isolated from the examined swimming pool water namely A. polyphaga, A.castellanii, A. rhysodes, A. mauritaniensis, A. royreba and A. triangularis. All the identified species of Acanthamoeba were molecularly confirmed to be related to the genus Acanthamoeba.The isolated species of Acanthamoeba could provoke variable degrees of infections to the swimmers. The culture method is cheaper and easier than PCR techniques that are faster for the detection of free-living amoebae.

  15. Construction of EST Database for Comparative Gene Studies of Acanthamoeba

    Science.gov (United States)

    Moon, Eun-Kyung; Kim, Joung-Ok; Xuan, Ying-Hua; Yun, Young-Sun; Kang, Se Won; Lee, Yong Seok; Ahn, Tae-In; Hong, Yeon-Chul; Chung, Dong-Il

    2009-01-01

    The genus Acanthamoeba can cause severe infections such as granulomatous amebic encephalitis and amebic keratitis in humans. However, little genomic information of Acanthamoeba has been reported. Here, we constructed Acanthamoeba expressed sequence tags (EST) database (Acanthamoeba EST DB) derived from our 4 kinds of Acanthamoeba cDNA library. The Acanthamoeba EST DB contains 3,897 EST generated from amebae under various conditions of long term in vitro culture, mouse brain passage, or encystation, and downloaded data of Acanthamoeba from National Center for Biotechnology Information (NCBI) and Taxonomically Broad EST Database (TBestDB). The almost reported cDNA/genomic sequences of Acanthamoeba provide stand alone BLAST system with nucleotide (BLAST NT) and amino acid (BLAST AA) sequence database. In BLAST results, each gene links for the significant information including sequence data, gene orthology annotations, relevant references, and a BlastX result. This is the first attempt for construction of Acanthamoeba database with genes expressed in diverse conditions. These data were integrated into a database (http://www.amoeba.or.kr). PMID:19488415

  16. ERRORES FRECUENTES EN EL DIAGNÓSTICO Y TRATAMIENTO DE LOS PACIENTES CON ENFERMEDAD INFLAMATORIA INTESTINAL

    Directory of Open Access Journals (Sweden)

    JAIME LUBASCHER C., DR.

    2015-09-01

    Full Text Available El creciente aumento de pacientes con enfermedad inflamatoria intestinal (EII, sumado a la multiplicidad de alternativas terapéuticas y a la poca experiencia en general de los médicos para tratar estas patologías, ya que son enfermedades emergentes, ha facilitado que se cometan errores tanto en el diagnóstico como en el tratamiento de las EII. En este artículo, se presentarán los más frecuentes e importantes, según la experiencia del autor, con el objeto de corregir estas conductas y alertar a los equipos médicos sobre éstas. El listado incluye errores cometidos en la historia clínica, laboratorio general, endoscopia y tratamiento.

  17. Bacteriolytic activities of the free-living soil amoebae, Acanthamoeba castellanii, Acanthamoeba polyphaga and Hartmannella vermiformis.

    Science.gov (United States)

    Weekers, P H; Engelberts, A M; Vogels, G D

    1995-10-01

    Bacteriolytic activities of axenically grown free-living soil amoebae Acanthamoeba castellanii, Acanthamoeba polyphaga and Hartmannella vermiformis towards various Gram-positive and Gram-negative bacteria were determined. A spectrophotometric assay revealed that the specific bacteriolytic activities of both Acanthamoeba species were higher as those of the three Hartmannella strains. Bacillus megaterium, Bacillus subtilis, Chromatium vinosum, Micrococcus luteus and Pseudomonas fluorescens were more easily lysed than the other bacteria tested. Agrobacterium tumefaciens, Klebsiella aerogenes and Serratia marcescens were hardly affected at all by the amoebal bacteriolytic activities. Among the Gram-negative bacteria we observed differences in lysis sensitivity while the Gram-positive bacteria tested were sensitive to lysis. Isoelectric focusing (IEF) gel-electrophoresis in the pH range 3-10 was performed to separate the bacteriolytic isoenzymes of amoebae. Bacteriolytic patterns were shown by using an activity assay in which lysis bands were formed in the agar/bacteria gel-overlay. The activity assay revealed remarkable differences in typical banding patterns for bacteriolytic activities among amoebae. Distinct differences between typical pI points of bacteriolytic activities in Acanthamoeba and Hartmannella were shown. Bacteriolytic activities of Hartmannella were more pronounced and observed in the isoelectric points (pI) range of 4.0-9.3 while for Acanthamoeba the range was pI 4.5-8.9.

  18. Estudio Transversal sobre la Relación entre Neuroticismo y Curso Clínico en Pacientes con Enfermedades Inflamatorias Intestinales

    OpenAIRE

    Juan Carlos Fernández Méndez; José Andrés Pérez Vidal; Berta Fernández Méndez

    2010-01-01

    En el presente trabajo se analiza la relación que existe entre neuroticismo y diversas condiciones médicas que hacen referencia al curso clínico de las enfermedades inflamatorias intestinales. Para desarrollar la investigación se tomaron medidas en neuroticismo mediante el Inventario de Personalidad de Eysenck a 106 participantes diagnosticados de colitis ulcerosa y enfermedad de Crohn. Los resultados reflejaron que la muestra global de pacientes con enfermedades inflamatorias intestinales mo...

  19. Acanthamoeba keratitis: improving the Scottish diagnostic service for the rapid molecular detection of Acanthamoeba species.

    Science.gov (United States)

    Alexander, Claire Low; Coyne, Michael; Jones, Brian; Anijeet, Deepa

    2015-07-01

    Acanthamoeba species are responsible for causing the potentially sight-threatening condition, Acanthamoeba keratitis, which is commonly associated with contact lens use. In this report, we highlight the challenges faced using conventional laboratory identification methods to identify this often under-reported pathogen, and discuss the reasons for introducing the first national service in Scotland for the rapid and sensitive molecular identification of Acanthamoeba species. By comparing culture and molecular testing data from a total of 63 patients (n = 80 samples) throughout Scotland presenting with ocular eye disease, we describe the improvement in detection rates where an additional four positive cases were identified using a molecular assay versus culture. The testing of a further ten patients by confocal imaging is also presented. This report emphasizes the importance of continuing to improve clinical laboratory services to ensure a prompt, correct diagnosis and better prognosis, in addition to raising awareness of this potentially debilitating opportunistic pathogen.

  20. Cell surface control of differentiation in Acanthamoeba.

    Science.gov (United States)

    Yang, S; Villemez, C

    1994-12-01

    Acanthamoeba castellanii (Neff) is a free-living soil amoeba with close relatives that are opportunistic pathogens. Trophozoites differentiate into cysts when deprived of nutrients; cysts convert into trophozoites, leaving the wall behind, in the presence of nutrients. The data presented here, which includes immunoaffinity purification of the receptor, indicate that cell surface molecular signals also control Acanthamoeba differentiation in both directions. Monoclonal antibodies that bind specifically to a 40 kD trophozoite protein initiate the encystment of trophozoites. When bound to cysts the same monoclonal antibodies prevent excystment. Washing away the antibody allows both trophozoites and cysts to resume normal activity. One of these monoclonal antibodies inhibits pinocytosis, while another has no effect on pinocytosis.

  1. The Development of Drugs against Acanthamoeba Infections

    Science.gov (United States)

    Siddiqui, Ruqaiyyah; Aqeel, Yousuf

    2016-01-01

    For the past several decades, there has been little improvement in the morbidity and mortality associated with Acanthamoeba keratitis and Acanthamoeba encephalitis, respectively. The discovery of a plethora of antiacanthamoebic compounds has not yielded effective marketed chemotherapeutics. The rate of development of novel antiacanthamoebic chemotherapies of translational value and the lack of interest of the pharmaceutical industry in developing such chemotherapies have been disappointing. On the other hand, the market for contact lenses/contact lens disinfectants is a multi-billion-dollar industry and has been successful and profitable. A better understanding of drugs, their targets, and mechanisms of action will facilitate the development of more-effective chemotherapies. Here, we review the progress toward phenotypic drug discovery, emphasizing the shortcomings of useable therapies. PMID:27600042

  2. The Development of Drugs against Acanthamoeba Infections.

    Science.gov (United States)

    Siddiqui, Ruqaiyyah; Aqeel, Yousuf; Khan, Naveed Ahmed

    2016-11-01

    For the past several decades, there has been little improvement in the morbidity and mortality associated with Acanthamoeba keratitis and Acanthamoeba encephalitis, respectively. The discovery of a plethora of antiacanthamoebic compounds has not yielded effective marketed chemotherapeutics. The rate of development of novel antiacanthamoebic chemotherapies of translational value and the lack of interest of the pharmaceutical industry in developing such chemotherapies have been disappointing. On the other hand, the market for contact lenses/contact lens disinfectants is a multi-billion-dollar industry and has been successful and profitable. A better understanding of drugs, their targets, and mechanisms of action will facilitate the development of more-effective chemotherapies. Here, we review the progress toward phenotypic drug discovery, emphasizing the shortcomings of useable therapies. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  3. Tratamiento cognitivo-conductual protocolizado en grupo de las enfermedades inflamatorias intestinales Protocolized cognitive-behavioural group therapy for inflammatory bowel disease

    Directory of Open Access Journals (Sweden)

    M. A. Díaz Sibaja

    2007-10-01

    Full Text Available Introducción: los pacientes con enfermedades inflamatorias intestinales presentan una mayor tasa de alteraciones psicopatológicas que la población normal, predominantemente ansiedad y depresión. Objetivo: el principal objetivo de este estudio fue diseñar, poner en práctica y validar un programa de tratamiento psicológico protocolizado, basado en el modelo de competencias y con una metodología psicoeducativa, en el que se incluyeron los siguientes módulos de intervención: información de la enfermedad, modelo de afrontamiento, solución de problemas, técnicas de relajación, entrenamiento en habilidades sociales, técnicas de distracción y técnicas de reestructuración cognitiva. Todas estás técnicas fueron adaptadas a la problemática característica de la enfermedad inflamatoria intestinal. Método: la muestra estuvo constituida por 57 pacientes diagnosticados de enfermedad inflamatoria intestinal de la Asociación de Enfermos de Crohn y Colitis Ulcerosa de España. La muestra se distribuyó aleatoriamente en dos grupos experimentales, 33 formaron parte del programa de tratamiento en grupo y 24 fueron asignados al grupo control en lista de espera. Las variables emocionales medidas fueron: ansiedad y depresión. Resultados: los resultados reflejaron una mejoría clínica y estadísticamente significativa en las variables de ansiedad (p Introduction: patients affected by inflammatory bowel disease have a high rate of psychiatric disorders such as depression and anxiety. Objective: the main goal of this study was to design, to put into practice, and to validate a protocolized psychological treatment program based on the coping model, and a psycho-educational methodology in which the following intervention modules were included- illness information, coping model, problem solving techniques, relaxation, social skill training, distraction, and cognitive restructuring techniques. All these techniques were adapted to the characteristic

  4. Acanthamoeba keratitis and contact lens wear.

    Science.gov (United States)

    Lindsay, Richard G; Watters, Grant; Johnson, Richard; Ormonde, Susan E; Snibson, Grant R

    2007-09-01

    Acanthamoeba keratitis is a rare but serious complication of contact lens wear that may cause severe visual loss. The clinical picture is usually characterised by severe pain, sometimes disproportionate to the signs, with an early superficial keratitis that is often misdiagnosed as herpes simplex virus (HSV) keratitis. Advanced stages of the infection are usually characterised by central corneal epithelial loss and marked stromal opacification with subsequent loss of vision. In this paper, six cases of contact lens-related Acanthamoeba keratitis that occurred in Australia and New Zealand over a three-year period are described. Three of the patients were disposable soft lens wearers, two were hybrid lens wearers and one was a rigid gas permeable lens wearer. For all six cases, the risk factors for Acanthamoeba keratitis were contact lens wear with inappropriate or ineffective lens maintenance and exposure of the contact lenses to tap or other sources of water. All six patients responded well to medical therapy that involved topical use of appropriate therapeutic agents, most commonly polyhexamethylene biguanide and propamidine isethionate, although two of the patients also subsequently underwent deep lamellar keratoplasty due to residual corneal surface irregularity and stromal scarring. Despite the significant advances that have been made in the medical therapy of Acanthamoeba keratitis over the past 10 years, prevention remains the best treatment and patients who wear contact lenses must be thoroughly educated about the proper use and care of the lenses. In particular, exposure of the contact lenses to tap water or other sources of water should be avoided.

  5. Influence of Acanthamoeba genotype on clinical course and outcomes for patients with Acanthamoeba keratitis in Spain.

    Science.gov (United States)

    Arnalich-Montiel, Francisco; Lumbreras-Fernández, Blanca; Martín-Navarro, Carmen M; Valladares, Basilio; Lopez-Velez, Rogelio; Morcillo-Laiz, Rafael; Lorenzo-Morales, Jacob

    2014-04-01

    Genotype T4 is by far the most frequent genotype of Acanthamoeba keratitis (AK) and therefore has been considered the most virulent. This study included 14 cases of AK of genotype T4 and three cases of non-T4 genotype. We found that cases of non-T4 genotype had a worse response to medical therapy, greater need for surgical intervention, greater risk of extracorneal involvement, and remarkably poorer final visual outcome than those of T4 genotype, suggesting an association between Acanthamoeba virulence and genotype that requires additional case investigation.

  6. Acanthamoeba Sp. S-11 phagocytotic activity on Mycobacterium ...

    African Journals Online (AJOL)

    Background: Mycobacterium leprae (M. leprae) is a pathogenic bacterium that causes leprosy. The presence of M. leprae in the environment is supported by microorganisms that act as the new host for M. leprae. Acanthamoeba's potential to be a host of M. leprae in the environment. Acanthamoeba sp. is Free Living ...

  7. Current Status of Acanthamoeba in Iran: A Narrative Review Article.

    Directory of Open Access Journals (Sweden)

    Maryam Niyyati

    2015-06-01

    Full Text Available Free-living amoebae belonging to the genus Acanthamoeba have an environmental distribution. Amoebic keratitis due to these protozoan parasites continue to rise in Iran and worldwide. In Iran, there are various researches regarding both morphological and molecular identification of Acanthamoeba spp. in environmental and clinical samples. However, there is no thorough review about Acanthamoeba genotypes and their distribution in environmental sources such as water, dust and biofilm in Iran. Besides, according to increasing cases of Amoebic keratitis in the region awareness regarding the pathogenic potential of these sight-threatening amoebae is of utmost importance.We conducted a thorough review based on the database sources such as MEDLINE, PubMed and Google scholar. No restrictions were placed on study date, study design or language of publication. We searched all valuable and relevant information considering the occurrence of the Acanthamoeba in both environmental and clinical samples.According to our thorough review Acanthamoeba belonging to T4 genotype is the most prevalent type strain in environmental and clinical samples in several regions in Iran and worldwide, however, there are reports regarding Acanthamoeba belonging to other genotypes such as T2, T3, T5, T6 and T11 and the mentioned point could leads us to more researches with the goal of presenting the real genotype dominance of Acanthamoeba and related disease in the country.Overall, the present review will focus on present status of genotypes of Acanthamoeba in Iran during recent years.

  8. Phospholipase Activities in Clinical and Environmental Isolates of Acanthamoeba

    Science.gov (United States)

    Matin, Abdul

    2011-01-01

    The pathogenesis and pathophysiology of Acanthamoeba infections remain incompletely understood. Phos-pholipases are known to cleave phospholipids, suggesting their possible involvement in the host cell plasma membrane disruption leading to host cell penetration and lysis. The aims of the present study were to determine phospholipase activities in Acanthamoeba and to determine their roles in the pathogenesis of Acanthamoeba. Using an encephalitis isolate (T1 genotype), a keratitis isolate (T4 genotype), and an environmental isolate (T7 genotype), we demonstrated that Acanthamoeba exhibited phospholipase A2 (PLA2) and phospholipase D (PLD) activities in a spectrophotometry-based assay. Interestingly, the encephalitis isolates of Acanthamoeba exhibited higher phospholipase activities as compared with the keratitis isolates, but the environmental isolates exhibited the highest phospholipase activities. Moreover, Acanthamoeba isolates exhibited higher PLD activities compared with the PLA2. Acanthamoeba exhibited optimal phospholipase activities at 37℃ and at neutral pH indicating their physiological relevance. The functional role of phospholipases was determined by in vitro assays using human brain microvascular endothelial cells (HBMEC), which constitute the blood-brain barrier. We observed that a PLD-specific inhibitor, i.e., compound 48/80, partially inhibited Acanthamoeba encephalitis isolate cytotoxicity of the host cells, while PLA2-specific inhibitor, i.e., cytidine 5'-diphosphocholine, had no effect on parasite-mediated HBMEC cytotoxicity. Overall, the T7 exhibited higher phospholipase activities as compared to the T4. In contract, the T7 exhibited minimal binding to, or cytotoxicity of, HBMEC. PMID:21461262

  9. Current Status of Acanthamoeba in Iran: A Narrative Review Article

    Science.gov (United States)

    NIYYATI, Maryam; REZAEIAN, Mostafa

    2015-01-01

    Background: Free-living amoebae belonging to the genus Acanthamoeba have an environmental distribution. Amoebic keratitis due to these protozoan parasites continue to rise in Iran and worldwide. In Iran, there are various researches regarding both morphological and molecular identification of Acanthamoeba spp. in environmental and clinical samples. However, there is no thorough review about Acanthamoeba genotypes and their distribution in environmental sources such as water, dust and biofilm in Iran. Besides, according to increasing cases of Amoebic keratitis in the region awareness regarding the pathogenic potential of these sight-threatening amoebae is of utmost importance. Methods: We conducted a thorough review based on the database sources such as MEDLINE, PubMed and Google scholar. No restrictions were placed on study date, study design or language of publication. We searched all valuable and relevant information considering the occurrence of the Acanthamoeba in both environmental and clinical samples. Results: According to our thorough review Acanthamoeba belonging to T4 genotype is the most prevalent type strain in environmental and clinical samples in several regions in Iran and worldwide, however, there are reports regarding Acanthamoeba belonging to other genotypes such as T2, T3, T5, T6 and T11 and the mentioned point could leads us to more researches with the goal of presenting the real genotype dominance of Acanthamoeba and related disease in the country. Conclusion: Overall, the present review will focus on present status of genotypes of Acanthamoeba in Iran during recent years. PMID:26246812

  10. Microbiological cure times in acanthamoeba keratitis.

    Science.gov (United States)

    Oldenburg, C E; Keenan, J D; Cevallos, V; Chan, M F; Acharya, N R; Gaynor, B D; McLeod, S D; Esterberg, E J; Porco, T C; Lietman, T M

    2011-09-01

    The purpose of this study was to estimate the duration of treatment necessary for sequential acanthamoeba laboratory tests from corneal scrapings to become negative, and to assess predictors that affect this duration period. We included all patients with at least one positive acanthamoeba culture or Giemsa stain at the F.I. Proctor Foundation Microbiology Laboratory from 1996 to 2009. A parametric survival analysis was performed among patients with repeat cultures to assess significant predictors for extended clearance time. Simulations were performed to estimate clearance time in the entire patient population, assuming imperfect sensitivity. Thirty-seven patients with laboratory evidence of acanthamoeba had testing at 69 time points. The median clearance time among eyes with repeat cultures was 42.5 days (interquartile range (IQR) 22.0-82.0 days; unadjusted parametric model). Initial visual acuity was the only predictor significantly associated with clearance time in univariate analyses (Pacanthamoeba keratitis undergoing treatment has not been well characterized. In this report we estimate a median clearance time of approximately 6 weeks, with an IQR of 22-82 days.

  11. [Evaluation of effective treatment drugs against Acanthamoeba cyst].

    Science.gov (United States)

    Tahara, K; Asari, S; Shimomura, Y; Endo, T; Yanagihara, T

    1997-10-01

    Cysts of 2 isolates of Acanthamoeba from the cornea of 2 patients with confirmed Acanthamoeba keratitis were tested in vitro for sensitivity to antimycotic agents such as fluconazole, miconazole, amphotericin-B, pimaricin, antiprotozoal agents such as pentamidine isetionate and antiseptics which could be use in the ophthamological region. Pimaricin was the most successful cysticidal agent against the two strains. Sensitivity to pentamidine isetionate showed variation. Fluconazole, miconazole and amphotericin-B were resistant against cysts with concentration of eye drops that have been used in the treatment of Acanthamoeba keratitis. It was supposed that 5% pimaricin eye drops could be use in the treatment of Acanthamoeba keratitis in addition to keratomycosis. Pentamidine isetionate which belong to the diamidine family, is not yet clear as to the side effects to corneal epithelium cell, but we believe that this drug could be expected as a new therapeutic agent for Acanthamoeba keratitis.

  12. Vaccination of patients with inflammatory bowel disease: Practical recommendations Vacunación de pacientes con enfermedad inflamatoria intestinal: Recomendaciones prácticas

    Directory of Open Access Journals (Sweden)

    Magda Campins

    2013-02-01

    Full Text Available Patients with inflammatory bowel disease (IBD have a greater risk of infection associated with the endogenous immunosuppression brought about by their underlying disease as well as the exogenous immunosuppression resulting from their therapies. In the last few years guidelines and consensus papers have been issued on the indication of vaccines for these patients as primary prevention of infection. However, vaccine coverage is low, likely because the risk for infection and both safety and efficacy concerns regarding vaccines are scarcely perceived in such cases. The available scientific evidence shows that immunization is safe for most preparations, and bears no association with an increased risk for disease activity. This paper reviews the available scientific literature, and provides recommendations on the vaccination of adults with IBD.Los pacientes con enfermedad inflamatoria intestinal (EII tienen un mayor riesgo de infecciones, asociado tanto a la inmunosupresión endógena condicionada por su enfermedad de base, como a la exógena generada por los tratamientos que reciben. En los últimos años se han publicado guías y documentos de consenso sobre indicaciones de vacunación en estos pacientes, como medida de prevención primaria de infecciones. Sin embargo, las coberturas vacunales alcanzadas son bajas, probablemente por la falta de percepción del riesgo de infección y las dudas sobre la seguridad y eficacia de las vacunas en estos casos. La evidencia científica disponible muestra que la inmunización es segura para la mayoría de preparados y no se asocia a un incremento del riesgo de actividad de la enfermedad. En este documento se revisa la literatura científica disponible y se presentan unas recomendaciones de vacunación para pacientes adultos con EII.

  13. In vitro comparative assessment of different viability assays in Acanthamoeba castellanii and Acanthamoeba polyphaga trophozoites.

    Science.gov (United States)

    Heredero-Bermejo, I; Copa-Patiño, J L; Soliveri, J; Gómez, R; de la Mata, F J; Pérez-Serrano, J

    2013-12-01

    The species of the genus Acanthamoeba are opportunistic protozoan parasites that cause different diseases in humans, such as amoebic keratitis and granulomatous encephalitis. The rise in the rate of Acanthamoeba keratitis, mainly due to the increase in contact lens wearers, turns the development of viability assays using a multi-well plate reader as a tool for screening new antiamoebic agents in vitro into an important goal. In our study, the viability assays PrestoBlue®, resazurin sodium salt, 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide (MTT) and CellTiter96® were tested for their suitability as time-saving alternatives to the classical manual or direct-counting method, assessing the effect of the antiamoebic agent chlorhexidine digluconate and temperature on Acanthamoeba castellanii (ATCC® 30234™) and Acanthamoeba polyphaga 2961. Although resazurin and MTT have already been previously used in amoeba viability assays to test the activities of antiamoebic agents in vitro, it is the first time that PrestoBlue® and CellTiter96® are used for this purpose. Results indicated that the viability assays were strain-dependent leading in some cases to an overestimation of the real situation of viable cells. This implies that each viability assay ought to be set up for each amoeba strain studied.

  14. Diversity and Seasonal Impact of Acanthamoeba Species in a Subtropical Rivershed

    Science.gov (United States)

    Kao, Po-Min; Chou, Ming-Yuan; Tao, Chi-Wei; Huang, Wen-Chien; Hsu, Bing-Mu; Shen, Shu-Min; Fan, Cheng-Wei; Chiu, Yi-Chou

    2013-01-01

    This study evaluated the presence of Acanthamoeba species in the Puzih River watershed, which features typical subtropical monsoon climate and is located just above the Tropic of Cancer in Taiwan. The relationship between the seasonal and geographical distributions of Acanthamoeba species in this rivershed was also investigated. Acanthamoeba species were detected in water samples using the amoebal enrichment culture method and confirmed by PCR. A total of 136 water samples were included in this study, 16 (11.7%) of which contained Acanthamoeba species. Samples with the highest percentage of Acanthamoeba (32.4%) were obtained during the summer season, mainly from upstream areas. The identified species in the four seasons included Acanthamoeba palestinensis (T2), Acanthamoeba sp. IS2/T4 (T4), Acanthamoeba lenticulata (T5), Acanthamoeba hatchetti (T11), Acanthamoeba healyi (T12), and Acanthamoeba jacobsi (T15). The most frequently identified Acanthamoeba genotype was T4 (68.7%). Acanthamoeba genotype T4 is responsible for Acanthamoeba keratitis and should be considered for associated human health risk potential in the rivershed. PMID:24490160

  15. Successful immunization against Acanthamoeba keratitis in a pig model.

    Science.gov (United States)

    Alizadeh, H; He, Y; McCulley, J P; Ma, D; Stewart, G L; Via, M; Haehling, E; Niederkorn, J Y

    1995-03-01

    The feasibility of inducing protective immunity to Acanthamoeba keratitis was tested in a pig model. Experiments were designed to determine if ocular infection with Acanthamoeba trophozoites would elicit protection against reinfection. Additional experiments examined whether injection of parasite antigens either intramuscularly, subconjunctivally, or by both routes would induce immunity. Therefore, four groups of animals were examined: (a) pigs that had resolved a primary corneal infection with Acanthamoeba; (b) pigs immunized intramuscularly; (c) pigs immunized subconjunctivally; and (d) pigs immunized intramuscularly and subconjunctivally. Animals were subsequently challenged with parasite-laden soft contact lenses and observed clinically for the appearance of Acanthamoeba keratitis. Acanthamoeba-specific serum antibody titers and blastogenic responses of peripheral blood lymphocytes were determined weekly. The results indicated that intramuscular injection of Acanthamoeba antigens failed to protect against ocular infection even though hosts developed high titers of IgG antibodies and displayed lymphocyte blastogenic responses to parasite antigens. Ocular infection alone failed to stimulate immunity in any of the animals. By contrast, 50% of the hosts immunized subconjunctivally were protected against corneal disease, and 100% of the animals immunized by a combination of intramuscular and subconjunctival administration of parasite antigens were completely protected against two separate ocular challenges with infectious parasites. Protection did not correlate with either IgG antibody titers or blastogenic potentials of peripheral blood lymphocytes. Interestingly, ocular infection alone failed to stimulate immunity to subsequent ocular challenge with infectious parasites. Thus, administration of parasite antigen via the subconjunctival route can protect against Acanthamoeba keratitis.

  16. Decreased corneal sensation as an initial feature of Acanthamoeba keratitis.

    Science.gov (United States)

    Perry, H D; Donnenfeld, E D; Foulks, G N; Moadel, K; Kanellopoulos, A J

    1995-10-01

    Herpes simplex keratitis is the most common misdiagnosis in patients with Acanthamoeba keratitis, which is increasing in frequency and is associated with daily wear soft contact lenses. Both entities usually present as unilateral keratitis. The manifestations of superficial Acanthamoeba keratitis (i.e., unilaterality, dendriform appearance, positive response to antivirals, and decreased corneal sensation) increase the opportunity for misdiagnosis as herpes simplex keratitis. The authors have encountered six patients with Acanthamoeba keratitis in whom the correct diagnosis was delayed from 2 weeks to 3 months. All six patients underwent testing with the Cochet-Bonnet esthesiometer and extensive pharmacologic treatment for herpes simplex keratitis. Corneal scrapings were taken between 2 and 6 weeks after the initial examination. In all six patients, corneal sensation was decreased significantly. Drug therapy was ineffective. Cultures were positive for Acanthamoeba. Five of six patients underwent penetrating keratoplasty. Decreased corneal sensation has contributed to the misdiagnosis of Acanthamoeba as herpes simplex keratitis. Misdiagnosis results in delayed treatment and worse outcome. The authors found that significantly decreased corneal sensation is a frequent finding in early Acanthamoeba keratitis. Therefore, physicians should consider Acanthamoeba keratitis as an alternative diagnosis in patients with presumed herpes simplex keratitis with decreased corneal sensation.

  17. An update on Acanthamoeba keratitis: diagnosis, pathogenesis and treatment

    Directory of Open Access Journals (Sweden)

    Lorenzo-Morales Jacob

    2015-01-01

    Full Text Available Free-living amoebae of the genus Acanthamoeba are causal agents of a severe sight-threatening infection of the cornea known as Acanthamoeba keratitis. Moreover, the number of reported cases worldwide is increasing year after year, mostly in contact lens wearers, although cases have also been reported in non-contact lens wearers. Interestingly, Acanthamoeba keratitis has remained significant, despite our advances in antimicrobial chemotherapy and supportive care. In part, this is due to an incomplete understanding of the pathogenesis and pathophysiology of the disease, diagnostic delays and problems associated with chemotherapeutic interventions. In view of the devastating nature of this disease, here we present our current understanding of Acanthamoeba keratitis and molecular mechanisms associated with the disease, as well as virulence traits of Acanthamoeba that may be potential targets for improved diagnosis, therapeutic interventions and/or for the development of preventative measures. Novel molecular approaches such as proteomics, RNAi and a consensus in the diagnostic approaches for a suspected case of Acanthamoeba keratitis are proposed and reviewed based on data which have been compiled after years of working on this amoebic organism using many different techniques and listening to many experts in this field at conferences, workshops and international meetings. Altogether, this review may serve as the milestone for developing an effective solution for the prevention, control and treatment of Acanthamoeba infections.

  18. Occurrence of Acanthamoeba Genotypes in Wastewater Samples in Tehran, Iran

    Directory of Open Access Journals (Sweden)

    Massoud BEHNIA

    2017-12-01

    Full Text Available AbstractBackground: Acanthamoeba spp. is potentially pathogenic free-living amoeba that can exist in various water sources. The presence of this amoeba in water sources could be a health hazard as Acanthamoeba could lead to severe diseases such as Acanthamoeba keratitis and encephalitis. This study aimed to determine the genotypes of isolated Acanthamoeba spp. in raw wastewater samples in Tehran, Iran.Methods: Overall, 90 raw wastewater samples were collected from water treatment facilities in west and south of Tehran, Iran during 2014-2016. Water samples were filtered and cultured on non-nutrient agar (NNA medium enriched with Escherichia coli. Morphological and molecular analyses were done on positive strains. The pathogenic ability of the isolated strains was determined using physical assays.Results: Totally, 6 out of 90 (6.7% samples were positive for Acanthamoeba, according to morphological characteristics of double-walled cysts. Genotyping and sequencing of the positive strains showed Acanthamoeba belonging to T4 (83% and T11 (17% genotypes. In vitro pathogenicity tests were revealed that five isolates were classified as non-pathogenic strains and one strain belonging to T4 genotype was classified as the highly pathogenic amoebae.Conclusion: The current research reflected a low contamination of wastewater sources to Acanthamoeba. More studies regarding the contamination of wastewaters before and after treatment are required in different places of the country.

  19. An update on Acanthamoeba keratitis: diagnosis, pathogenesis and treatment.

    Science.gov (United States)

    Lorenzo-Morales, Jacob; Khan, Naveed A; Walochnik, Julia

    2015-01-01

    Free-living amoebae of the genus Acanthamoeba are causal agents of a severe sight-threatening infection of the cornea known as Acanthamoeba keratitis. Moreover, the number of reported cases worldwide is increasing year after year, mostly in contact lens wearers, although cases have also been reported in non-contact lens wearers. Interestingly, Acanthamoeba keratitis has remained significant, despite our advances in antimicrobial chemotherapy and supportive care. In part, this is due to an incomplete understanding of the pathogenesis and pathophysiology of the disease, diagnostic delays and problems associated with chemotherapeutic interventions. In view of the devastating nature of this disease, here we present our current understanding of Acanthamoeba keratitis and molecular mechanisms associated with the disease, as well as virulence traits of Acanthamoeba that may be potential targets for improved diagnosis, therapeutic interventions and/or for the development of preventative measures. Novel molecular approaches such as proteomics, RNAi and a consensus in the diagnostic approaches for a suspected case of Acanthamoeba keratitis are proposed and reviewed based on data which have been compiled after years of working on this amoebic organism using many different techniques and listening to many experts in this field at conferences, workshops and international meetings. Altogether, this review may serve as the milestone for developing an effective solution for the prevention, control and treatment of Acanthamoeba infections. © J. Lorenzo-Morales et al., published by EDP Sciences, 2015.

  20. Acanthamoeba: epidimiology, pathogenicity and evaluation of effectiveness of recent drugs

    International Nuclear Information System (INIS)

    Issa, R.M.

    2007-01-01

    To study the epidimiology of Acanthamoeba and to evaluate the effectiveness of some recent drugs against parasite. The study was carried out from March to May 2005 at the ophthalmic clinic of King Fahad Hospital, Saudi Arabia. Samples of rinsing solutions and saline of contact lens, tap water, Swimming pool water and Soil from Hufof city Saudi Arabia were tested. Mice were used to infect them via intranasal inoculation from isolated culture strain for confirming pathogenicity. Rokitamycin, polymixin B, suramin and chloropromazin were used to study their effects on Acanthamoeba growth in vitro. Acanthamoeba were detected in 20% of solution of contact lens, 20% of tap water, 50% of swimming pool samples and 40% of soil samples. All animals died or were sacrificed and had Acanthamoeba isolated from their organs. Higher percentage of growth inhibition of Acanthamoeba cultured was shown by chloropromazine and rokitamycin after 21 days (100%), while Polymyin B and Suramin showed 83% and 64% inhibition respectively. Acanthamoeba isolated in significant percent of environmental sources. Pathogenicity of organism was confirmed in mice. Contact lens wearers should be aware of the risks associated with Acanthamoeba. Rokitamycin and chlorpromazine showed good inhibition in vitro. (author)

  1. An update on Acanthamoeba keratitis: diagnosis, pathogenesis and treatment

    Science.gov (United States)

    Lorenzo-Morales, Jacob; Khan, Naveed A.; Walochnik, Julia

    2015-01-01

    Free-living amoebae of the genus Acanthamoeba are causal agents of a severe sight-threatening infection of the cornea known as Acanthamoeba keratitis. Moreover, the number of reported cases worldwide is increasing year after year, mostly in contact lens wearers, although cases have also been reported in non-contact lens wearers. Interestingly, Acanthamoeba keratitis has remained significant, despite our advances in antimicrobial chemotherapy and supportive care. In part, this is due to an incomplete understanding of the pathogenesis and pathophysiology of the disease, diagnostic delays and problems associated with chemotherapeutic interventions. In view of the devastating nature of this disease, here we present our current understanding of Acanthamoeba keratitis and molecular mechanisms associated with the disease, as well as virulence traits of Acanthamoeba that may be potential targets for improved diagnosis, therapeutic interventions and/or for the development of preventative measures. Novel molecular approaches such as proteomics, RNAi and a consensus in the diagnostic approaches for a suspected case of Acanthamoeba keratitis are proposed and reviewed based on data which have been compiled after years of working on this amoebic organism using many different techniques and listening to many experts in this field at conferences, workshops and international meetings. Altogether, this review may serve as the milestone for developing an effective solution for the prevention, control and treatment of Acanthamoeba infections. PMID:25687209

  2. The possibility of congenital infection with Acanthamoeba culbertsoni.

    Science.gov (United States)

    Awadalla, H N; Sadaka, H A

    1996-12-01

    Acanthamoeba culbertsoni is one of the free-living amoebae which are known to be pathogenic to man, causing granulomatous amoebic encephalitis (GAE). In this study, Acanthamoeba culbertsoni was isolated from a water sample of El-Mahmoudia Canal in Alexandria, in July-1993. This was used to infect mice intranasally to study the histopathological picture of the brain and lungs. The neuropathological features consisted of chronic granulomatous encephalitis in which cysts and trophozoites were found. Associated Acanthamoeba pneumonitis with massive consolidation was also observed. Congenital infection of offsprings was reported for the first time in this study.

  3. A clinical Acanthamoeba isolate harboring two distinct bacterial endosymbionts.

    Science.gov (United States)

    Müller, Anneliese; Walochnik, Julia; Wagner, Martin; Schmitz-Esser, Stephan

    2016-10-01

    Acanthamoebae feed on bacteria but are also frequent hosts of bacterial symbionts. Here, we describe the stable co-occurrence of two symbionts, one affiliated to the genus Parachlamydia and the other to the candidate genus Paracaedibacter (Alphaproteobacteria), within a clinical isolate of Acanthamoeba hatchetti genotype T4. We performed fluorescence in situ hybridization (FISH) and transmission electron microscopy (TEM) to describe this symbiosis. Our study adds to other reports of simultaneous co-occurrence of two symbionts within one Acanthamoeba cell. Copyright © 2016 Elsevier GmbH. All rights reserved.

  4. Estudio PET/TC en patología inflamatoria-infecciosa PET/CT in infectious and inflammatory pathology

    Directory of Open Access Journals (Sweden)

    Cecilia Carrera

    2012-06-01

    Full Text Available Objetivo. Demostrar la utilidad del examen PET/TC en patología inflamatoria-infecciosa. Materiales y Métodos. Evaluación retrospectiva (enero de 2009 - mayo de 2011 de los exámenes de tomografía por Emisión de Positrones/ Tomografía Computada (PET/TC, realizados en nuestra institución con un equipo híbrido SIEMENS-BIOGRAPH 16 (Siemens, Erlangen, Alemania. Se seleccionaron 5 pacientes. Resultados. Caso 1: paciente de 68 años de edad con fiebre de 6 meses de duración, fatiga y pérdida de peso. El examen reumatológico demostró disminución en pulsos radiales sin otros síntomas asociados. La paciente fue sometida a biopsia de arteria temporal. Ésta confirmó una arteritis de la arteria temporal y el estudio PET/TC demostró hipermetabolismo en la aorta torácica y ramas principales. Caso 2: paciente de 85 años con fiebre de origen desconocido (FOD y sospecha de osteomielitis de cadera. En contraposición, el PET/TC demostró un foco ávido de celulitis glútea y neumopatía. Caso 3: paciente de 35 años con fiebre vespertina. El PET/TC mostró múltiples adenomegalias ávidas por fluorodexosiglucosa (FDG en mediastino, axilas y retroperitoneo, y compromiso difuso esplénico asociado a calcificaciones. Se confirmó infección por citomegalovirus por inmuno-globulina G y M. Caso 4: paciente de 39 años con infección por HIV que consultó por hipercalcemia. El PET/TC mostró implantes de silicona en glúteos con proceso inflamatorio ávido asociado. Se confirmó por la biopsia de uno de ellos. Caso 5: paciente de 45 años con historia de cáncer de mama en control presentó en los últimos estudios tomográficos aumento del tamaño de los ganglios supraclaviculares y mediastínicos, y compromiso esplénico multifocal difuso. Estos resultaron ávidos en el examen PET/TC. Se confirmó el diagnóstico de sarcoidosis por el estudio anatomopatológico de un ganglio supraclavicular. Conclusiones. El PET/TC es un método no invasivo de

  5. Osmolarity is an independent trigger of Acanthamoeba castellanii differentiation.

    Science.gov (United States)

    Cordingley, J S; Wills, R A; Villemez, C L

    1996-05-01

    Like many yeasts, bacteria, and other sporulating microorganisms, Acanthamoeba castellanii (Neff), a free-living amoeba with pathogenic relatives, differentiates into a dormant form when deprived of nutrients. Acanthamoeba cysts redifferentiate into trophozoites when food is resupplied. We report here that Acanthamoeba encystment is also triggered by elevated osmolarity, and that osmolarity and cell surface receptor binding are synergistic in triggering differentiation. Additions of sodium chloride or glucose to rich growth media were used to produce specific osmolarity increases and similar encystment results were obtained with either additive. Although many organisms, including Acanthamoeba and mammalian cells, have been shown to adapt to hyperosmolar conditions, this is the first demonstration that hyperosmolarity can be a primary differentiation signal.

  6. Survival of Acanthamoeba in contact lens rinse solutions.

    Science.gov (United States)

    Nauheim, R C; Brockman, R J; Stopak, S S; Turgeon, P W; Keleti, G; Roat, M I; Thoft, R A

    1990-10-01

    Acanthamoeba may cause a severe keratitis in contact lens wearers. Since most sterilization techniques require rinsing the lenses prior to insertion, contaminated solutions represent a potential vector for transmission of Acanthamoeba. The ability of rinse solutions to sustain an inoculum of Acanthamoeba polyphaga was investigated. A. polyphaga was exposed to 0.1% benzalkonium chloride, 0.001% thimerosal/0.1% edetate disodium, 0.1% edetate disodium, saline, tap water, and distilled water. The status of the organism was evaluated with direct microscopic counts and cultures to confirm viability. Incubation with 0.1% edetate disodium, saline, tap water, and distilled water resulted in the maintenance of reduced populations of viable organisms for 7 days. Benzalkonium chloride preserved saline and solutions containing thimerosal with edetate rendered the Acanthamoeba nonviable.

  7. Advances in the Diagnosis and Treatment of Acanthamoeba Keratitis

    Directory of Open Access Journals (Sweden)

    Benjamin Clarke

    2012-01-01

    Full Text Available This paper aims to review the recent literature describing Acanthamoeba keratitis and outline current thoughts on pathogenesis, diagnosis, and treatment as well as currently emerging diagnostic and treatment modalities.

  8. Raman microspectroscopy analysis in the treatment of acanthamoeba keratitis.

    Science.gov (United States)

    Rusciano, Giulia; Capriglione, Paola; Pesce, Giuseppe; Del Prete, Salvatore; Cennamo, Gilda; Di Cave, David; Cerulli, Luciano; Sasso, Antonio

    2013-01-01

    Acanthamoeba keratitis is a rare but serious corneal disease, often observed in contact lens wearers. Clinical treatment of infected patients frequently involves the use of polyhexamethylene biguanide (PHMB), a polymer used as a disinfectant and antiseptic, which is toxic also for the epithelial cells of the cornea. Prompt and effective diagnostic tools are hence highly desiderable for both starting early therapy and timely suspension of the treatment. In this work we use Raman microspectroscopy to analyse in vitro a single Acanthamoeba cell in cystic phase. In particular, we investigate the effect of PHMB at the single-cell level, providing useful information on both the underlying biochemical mechanism and the time frame for Acanthamoeba eradication in ocular infections. Furthermore, we demonstrate that Raman spectroscopy, in conjunction with standard multivariate analysis methods, allows discriminating between live and dead Acanthamoebas, which is fundamental to optimizing patients' treatment.

  9. Raman microspectroscopy analysis in the treatment of acanthamoeba keratitis.

    Directory of Open Access Journals (Sweden)

    Giulia Rusciano

    Full Text Available Acanthamoeba keratitis is a rare but serious corneal disease, often observed in contact lens wearers. Clinical treatment of infected patients frequently involves the use of polyhexamethylene biguanide (PHMB, a polymer used as a disinfectant and antiseptic, which is toxic also for the epithelial cells of the cornea. Prompt and effective diagnostic tools are hence highly desiderable for both starting early therapy and timely suspension of the treatment. In this work we use Raman microspectroscopy to analyse in vitro a single Acanthamoeba cell in cystic phase. In particular, we investigate the effect of PHMB at the single-cell level, providing useful information on both the underlying biochemical mechanism and the time frame for Acanthamoeba eradication in ocular infections. Furthermore, we demonstrate that Raman spectroscopy, in conjunction with standard multivariate analysis methods, allows discriminating between live and dead Acanthamoebas, which is fundamental to optimizing patients' treatment.

  10. Pathobiology and Immunobiology of Acanthamoeba Keratitis: Insights from Animal Models


    Science.gov (United States)

    Neelam, Sudha; Niederkorn, Jerry Y.

    2017-01-01

    Acanthamoeba keratitis (AK) is a rare but sight-threatening disease caused by pathogenic species of Acanthamoeba. Despite its ubiquitous nature, the incidence of AK is relatively low compared to other forms of infectious keratitis. Although contact lens wear is a major risk factor, exposure to contaminated water and ocular trauma are also associated with AK. Once a patient develops AK the prognosis is very poor unless an aggressive treatment regimen is initiated early. Some of the intriguing features of AK are the lack of immunological memory, resistance of the dormant cyst form to treatment, differences between the pathogenic strains and soil isolates of Acanthamoeba and the unique role of the innate immune system in controlling this disease. Understanding the series of steps involved in the pathogenesis of the disease and the host immune response against Acanthamoeba antigens is crucial for developing effective therapeutic strategies targeting the disease. PMID:28656012

  11. Acanthamoeba keratitis-A report of two cases

    Directory of Open Access Journals (Sweden)

    Girija T

    1992-01-01

    Full Text Available Two cases of unilateral corneal ulcers caused by Acanthamoeba are reported. Neither of the patients had contact lenses at any time. The diagnosis was confirmed by Giemsa stain and cultures of the corneal scrapings.

  12. Genotyping of Acanthamoeba spp. from water sources from Northwestern Iran.

    Science.gov (United States)

    Haniloo, Ali; Pezeshki, Ali; Mahmmodzadeh, Abbas; Kadkhodamohammadi, Elnaz

    2017-12-20

    Acanthamoeba spp. are free-living amoebae which are ubiquitously distributed worldwide and can be found in the wide range of environments, particularly in various types of water sources, where they able to cause important health problems. In the present study, cultures containing Acanthamoeba from water samples were obtained from our earlier survey. For an analysis of the genetic pattern of Acanthamoeba isolates, DNA sequencing of nuclear small-subunit rRNA gene (18S rRNA or Rns) was applied. A phylogenetic analyses of the isolates displayed that all of them were belonged to the potentially pathogenic T4 genotype. This investigation provides further evidence that the T4 genotype is the most prevalent in water samples and demonstrates that there is a need for taking more consideration to water sources in order to prevent complications associated with pathogenic Acanthamoeba spp.

  13. Pathobiology and Immunobiology of Acanthamoeba Keratitis: Insights from Animal Models
.

    Science.gov (United States)

    Neelam, Sudha; Niederkorn, Jerry Y

    2017-06-01

    Acanthamoeba keratitis (AK) is a rare but sight-threatening disease caused by pathogenic species of Acanthamoeba . Despite its ubiquitous nature, the incidence of AK is relatively low compared to other forms of infectious keratitis. Although contact lens wear is a major risk factor, exposure to contaminated water and ocular trauma are also associated with AK. Once a patient develops AK the prognosis is very poor unless an aggressive treatment regimen is initiated early. Some of the intriguing features of AK are the lack of immunological memory, resistance of the dormant cyst form to treatment, differences between the pathogenic strains and soil isolates of Acanthamoeba and the unique role of the innate immune system in controlling this disease. Understanding the series of steps involved in the pathogenesis of the disease and the host immune response against Acanthamoeba antigens is crucial for developing effective therapeutic strategies targeting the disease.

  14. Phagocytosis occurs in Acanthamoeba castellanii after electroporation.

    Science.gov (United States)

    Dybowska, U; Krawczynska, W; Sobota, A

    1996-09-01

    Acanthamoeba cells treated with an electric discharge were porated and their cytoplasm became accessible to exogenous molecules. Over a broad range of electric field densities low molecular weight markers (trypan blue, ruthenium red), normally unable to penetrate a plasma membrane, gained access to cytoplasm of 80-90% of the cells. Macromolecules (albumin-FITC and IgG-FITC) penetrated into 63-86% of the cells when electroporation was carried out over the range of 1500V/25 microF-400V/250 microF. Pulse labeling with fluorescent markers evidenced that even 3 hrs. after an electric pulse the plasma membrane was still permeable to exogenous fluorescent probes. Following this stage, the pores were gradually closed. The cells electroporated at 400 V/250 microF were able to ingest yeast particles. The uptake of the particles seems to be an active process since it was inhibited by azide and phalloidin. Therefore, the electroporation of Acanthamoeba makes possible the introduction of macromolecules into the cells and subsequent analysis of their effect on active motile processes such as phagocytosis. This should greatly facilitate characterization of the mechanisms by which such processes do occur.

  15. Gene discovery in the Acanthamoeba castellanii genome

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Iain J.; Watkins, Russell F.; Samuelson, John; Spencer,David F.; Majoros, William H.; Gray, Michael W.; Loftus, Brendan J.

    2005-08-01

    Acanthamoeba castellanii is a free-living amoeba found in soil, freshwater, and marine environments and an important predator of bacteria. Acanthamoeba castellanii is also an opportunistic pathogen of clinical interest, responsible for several distinct diseases in humans. In order to provide a genomic platform for the study of this ubiquitous and important protist, we generated a sequence survey of approximately 0.5 x coverage of the genome. The data predict that A. castellanii exhibits a greater biosynthetic capacity than the free-living Dictyostelium discoideum and the parasite Entamoeba histolytica, providing an explanation for the ability of A. castellanii to inhabit adversity of environments. Alginate lyase may provide access to bacteria within biofilms by breaking down the biofilm matrix, and polyhydroxybutyrate depolymerase may facilitate utilization of the bacterial storage compound polyhydroxybutyrate as a food source. Enzymes for the synthesis and breakdown of cellulose were identified, and they likely participate in encystation and excystation as in D. discoideum. Trehalose-6-phosphate synthase is present, suggesting that trehalose plays a role in stress adaptation. Detection and response to a number of stress conditions is likely accomplished with a large set of signal transduction histidine kinases and a set of putative receptorserine/threonine kinases similar to those found in E. histolytica. Serine, cysteine and metalloproteases were identified, some of which are likely involved in pathogenicity.

  16. Trastornos tiroideos e infecciones oportunistas: estudio de dos situaciones complejas en pacientes con miopatía inflamatoria idiopática

    OpenAIRE

    Redondo Benito, Ada

    2016-01-01

    Esta tesis doctoral parte con la intención de analizar dos situaciones complejas en el manejo práctico de los pacientes con miopatía inflamatoria idiopática. En la primera parte, se ha analizado la posible implicación de la disfunción tiroidea en la historia natural de la miopatía inflamatoria. Se estudió pues, la prevalencia de la disfunción tiroidea en nuestra cohorte de pacientes con miopatía inflamatoria y el papel que puede desempeñar dicha disfunción en la exacerbación, así como en la f...

  17. Several staining techniques to enhance the visibility of Acanthamoeba cysts.

    Science.gov (United States)

    El-Sayed, Nagwa Mostafa; Hikal, Wafaa Mohamed

    2015-03-01

    Acanthamoeba is one of the most common free-living amoebae. It is widespread in the environment and can infect humans causing keratitis. Delayed diagnosis or misdiagnosis leads to extensive corneal inflammation and profound visual loss. Therefore, accurate and rapid diagnosis of Acanthamoeba keratitis is essential for successful treatment and good prognosis. This study was designed to use different staining techniques to facilitate the identification of Acanthamoeba cysts. Acanthamoeba cysts were isolated by cultivation of either corneal scraping specimens or tap water samples onto non-nutrient agar plates seeded with Escherichia coli. Subcultures were done from positive cultures until unique cysts were isolated. Acanthamoeba cysts were stained temporarily using iodine, eosin, methylene blue, and calcofluor white (CFW) stains and as permanent slides after processing for mounting using modified trichrome, Gimenez and Giemsa staining. These stains were compared on the basis of staining quality including clarity of morphological details, differentiation between cytoplasm and nuclei, color and contrast, and also other characteristics of the staining techniques, including ease of handling, time taken for the procedure, and cost effectiveness. The cysts of Acanthamoeba were recognized in the form of double-walled cysts: the outer wall (ectocyst) that was being differentiated from the variably stained surrounding background and the inner wall (endocyst) that was sometimes stellated, polygonal, round, or oval and visualized as separate from the spherical, sometimes irregular, outline of the ectocyst. Regarding the temporary stains, it was found that they were efficient for visualizing the morphological details of Acanthamoeba cysts. In CFW staining, Acanthamoeba cysts appeared as bluish-white or turquoise oval halos although the internal detail was not evident. On the other hand, the results of permanent-stained slides showed the most consistent stain for identification of

  18. Acanthamoeba corneal infection in a contact lens wearer.

    Science.gov (United States)

    Logar, J; Kraut, A

    1997-11-01

    Corneal infections cause by micro-organisms are the most serious complications of wearing contact lenses. The paper presents the first case of contact lens-associated keratitis caused by the protozoon Acanthamoeba sp. identified in Slovenia so far. The identification of Acanthamoeba as a cause of keratitis in a soft contact lens wearer alerted us to the fact that this health issue should be given more attention in the future.

  19. Acanthamoeba keratitis: experience in a non-specialist microbiology laboratory.

    Science.gov (United States)

    Anderson, D; Soo, S S; Towler, H

    1991-01-01

    Acanthamoeba keratitis is an unusual complication of wearing soft contact lenses: a case was diagnosed by culturing corneal scrapings. Acanthamoeba are tolerant of variations in osmolarity in the culture media. Page's saline, recommended for culture agar plates, can easily be substituted with salines which are suitable for cell culture media, thereby avoiding the cumbersome manufacture of special saline. Early diagnosis as a result of successful isolation may avoid the need for keratoplasty. PMID:1890209

  20. Effects of Mannose on Pathogenesis of Acanthamoeba castellanii

    OpenAIRE

    Yoo, Kyung-Tae; Jung, Suk-Yul

    2012-01-01

    Acanthamoeba spp. are single-celled protozoan organisms that are widely distributed in the environment. In this study, to understand functional roles of a mannose-binding protein (MBP), Acanthamoeba castellanii was treated with methyl-alpha-D-mannopyranoside (mannose), and adhesion and cytotoxicity of the amoeba were analyzed. In addition, to understand the association of MBP for amoeba phagocytosis, phagocytosis assay was analyzed using non-pathogenic bacterium, Escherichia coli K12. Amoebae...

  1. Ex vivo laser confocal microscopy findings of cultured Acanthamoeba trophozoites

    Directory of Open Access Journals (Sweden)

    Yamazaki N

    2012-08-01

    Full Text Available Natsuko Yamazaki,1 Akira Kobayashi,1 Hideaki Yokogawa,1 Yasuhisa Ishibashi,2 Yosaburo Oikawa,3 Masaharu Tokoro,4 Kazuhisa Sugiyama11Department of Ophthalmology, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan; 2Department of Ophthalmology, East Washinomiya Hospital, Kuki, Japan; 3Department of Medical Zoology, Kanazawa Medical University, Kahoku, Japan; 4Department of Parasitology, Kanazawa University Graduate School of Medical Science, Kanazawa, JapanPurpose: The purpose of the current study was to investigate ex vivo laser confocal microscopic findings of cultured Acanthamoeba trophozoites obtained from Acanthamoeba keratitis patients.Methods: Eight cultured samples of Acanthamoeba trophozoites from eight eyes of seven patients (mean age, 26.9 years; age range, 18–52 years were used. Seven samples were from corneal scrapings of Acanthamoeba keratitis patients and one sample was from the solution in a soft contact lens case. Ex vivo laser confocal microscopy was performed to qualitatively evaluate the shape and degree of light reflection of the living Acanthamoeba trophozoites.Results: Ex vivo laser confocal microscopy demonstrated highly reflective, high-contrast Acanthamoeba trophozoites with no walls (mean size, 25.4 µm; range, 17.1–58.5 µm. The shapes of the trophozoites were highly pleomorphic, and some showed characteristic acanthopodia by laser confocal microscopy.Conclusion: Ex vivo laser confocal microscopy was effective in demonstrating cultured Acanthamoeba trophozoites of various shapes and sizes. The observations of the current study may be helpful when similar structures are identified under in vivo conditions.Keywords: Acanthamoeba, trophozoite, laser confocal microscopy

  2. Desarrollo de un nuevo medicamento con acetato de hidrocortisona para el tratamiento de la enfermedad inflamatoria intestinal (EII)

    OpenAIRE

    Ascaso Anglés, Magda

    2015-01-01

    El objetivo principal de este estudio consiste en la investigación y desarrollo de la formulación de un nuevo medicamento semisólido con acetato de hidrocortisona en forma farmacéutica de enema rectal. Esta formulación pretende cubrir un vacío terapéutico en el tratamiento de la Enfermedad inflamatoria intestinal, en concreto la colitis ulcerosa. Para ello es necesario tener en cuenta las especificaciones indicadas en la modificación de la Ley del Medicamento y posteriores circulares del Mini...

  3. Papel de la osmolaridad en el desarrollo de patología inflamatoria de la superficie ocular

    OpenAIRE

    Salgado Arrabal, Noemí

    2016-01-01

    Revisión sobre el papel que juega la osmolaridad en las patologías inflamatorias de la superficie ocular centrándonos principalmente en el ojo seco. Abarca desde el 1980 hasta la actualidad. Se describen las diferentes capas de la superficie ocular y los componentes de la unidad funcional lagrimal, así como el ojo seco y su clasificación actual. Se centra en los estudios que hay sobre el papel de la osmolaridad en la patología del ojo seco y en llegar a una conclusión sobre si juega un papel ...

  4. Isolation of Acanthamoeba from the rhizosphere of maize and lucerne plants

    Science.gov (United States)

    Orosz, Erika; Farkas, Ágnes; Ködöböcz, László; Becsak, Péter; Danka, József; Kucsera, István; Füleky, György

    2013-04-01

    Acanthamoeba species are free-living amoebae that can be found in almost every range of environments. Within this genus, a number of species are recognized as human pathogens, potentially causing Acanthamoeba keratitis, granulomatous amoebic encephalitis, and chronic granulomatous lesions. Soil and water samples were taken from experimental station at Julianna Major of Plant Protection Institute of Centre for Agricultural Research, Hungarian Academy of Sciences. We detected living Acanthamoeba spp. based on culture- confirmed detection combined with the molecular taxonomic identification method. Living Acanthamoeba spp. were detected in thirteen (65%) samples. The presence of Acanthamoeba spp. in the samples depends significantly on the rhizosphere plants. The most frequently identified living Acanthamoeba genotype was T4 followed by T11, T2/T6 and T17. Genotypes T4 and T11 of Acanthamoeba, are responsible for Acanthamoeba keratitis as well as granulomatous amoebic encephalitis, and should therefore be considered as a potential health risk associated with human activities in the environment.

  5. Outbreak of keratitis presumed to be caused by Acanthamoeba.

    Science.gov (United States)

    Mathers, W D; Sutphin, J E; Folberg, R; Meier, P A; Wenzel, R P; Elgin, R G

    1996-02-01

    A sharp increase of Acanthamoeba keratitis from two cases per year to 30 cases per year at our institution prompted this study to determine whether there was a change in the clinical characteristics, basic epidemiology, and outcome of this disease. We reviewed all cases of Acanthamoeba keratitis diagnosed at the University of Iowa Hospitals and Clinics from mid-1993 through 1994. We screened 217 patients with keratitis by tandem scanning confocal microscopy and suspected Acanthamoeba in 51 patients. Diagnosis was confirmed by cytology in 43 patients (48 eyes). There were no positive cultures. Patients examined within four weeks of onset of symptoms were younger (mean age, 32.6 +/- 15.4 years) and wore contact lenses (11 of 18 patients), and infrequently herpes simplex keratitis (four of 18 patients) was diagnosed. Patients examined after four weeks were older (mean age, 54.0 +/- 19.5 years), infrequently wore contact lenses (six of 25 patients), and often had herpes simplex keratitis (12 of 25 patients). Corneal examination with tandem scanning confocal microscopy was associated with a marked increase in the detection of Acanthamoeba, strongly suggesting that the disease is more prevalent than suspected. Acanthamoeba may account for many cases of clinically presumed herpes simplex keratitis, the leading cause of corneal blindness in the United States. Acanthamoeba should be considered in the differential diagnosis of any unexplained keratitis, even those of short duration.

  6. Statins and voriconazole induce programmed cell death in Acanthamoeba castellanii.

    Science.gov (United States)

    Martín-Navarro, Carmen M; López-Arencibia, Atteneri; Sifaoui, Ines; Reyes-Batlle, María; Valladares, Basilio; Martínez-Carretero, Enrique; Piñero, José E; Maciver, Sutherland K; Lorenzo-Morales, Jacob

    2015-05-01

    Members of the genus Acanthamoeba are facultative pathogens of humans, causing a sight-threatening keratitis and a life-threatening encephalitis. In order to treat those infections properly, it is necessary to target the treatment not only to the trophozoite but also to the cyst. Furthermore, it may be advantageous to avoid parasite killing by necrosis, which may induce local inflammation. We must also avoid toxicity of host tissue. Many drugs which target eukaryotes are known to induce programmed cell death (PCD), but this process is poorly characterized in Acanthamoeba. Here, we study the processes of programmed cell death in Acanthamoeba, induced by several drugs, such as statins and voriconazole. We tested atorvastatin, fluvastatin, simvastatin, and voriconazole at the 50% inhibitory concentrations (IC50s) and IC90s that we have previously established. In order to evaluate this phenomenon, we investigated the DNA fragmentation, one of the main characteristics of PCD, with quantitative and qualitative techniques. Also, the changes related to phosphatidylserine exposure on the external cell membrane and cell permeability were studied. Finally, because caspases are key to PCD pathways, caspase activity was evaluated in Acanthamoeba. All the drugs assayed in this study induced PCD in Acanthamoeba. To the best of our knowledge, this is the first study where PCD induced by drugs is described quantitatively and qualitatively in Acanthamoeba. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  7. Genotyping of clinical isolates of Acanthamoeba genus in Venezuela.

    Science.gov (United States)

    Wagner, Carolina; Reyes-Batlle, María; Ysea, María Alejandra Vethencourt; Pérez, Mónica V Galindo; de Rondón, Carmen Guzmán; Paduani, Anaibeth J Nessi; Pérez, Angelyseb Dorta; López-Arencibia, Atteneri; Sifaoui, Ines; de Galindo, María Virginia Pérez; de Suárez, Eva Pérez; Martínez-Carretero, Enrique; Valladares, Basilio; Piñero, José E; Lorenzo-Morales, Jacob

    2016-12-01

    Free-living amoebae of Acanthamoeba genus are opportunistic pathogens distributed worldwide. Strains included in this genus are causative agents of a fatal encephalitis and a sight-threating keratitis in humans and other animals. In this study, 550 clinical samples which were collected between 1984 and 2014 from different patients with suspected infections due to Acanthamoeba were initially screened for the presence of this amoebic genus at the Laboratorio de Amibiasis-Escuela de Bioanálisis at the Universidad Central de Venezuela. Samples were cultured in 2% Non-Nutrient agar plates seeded with a layer of heat killed Escherichia coli. From the 550 clinical samples included in this study, 18 of them were positive for Acanthamoeba genus after culture identification. Moreover, positive samples were confirmed after amplification of the Diagnostic Fragment 3 (DF3) of the Acanthamoeba18S rDNA genus and sequencing was carried out in order to genotype the isolated strains of Acanthamoeba. Furthermore, the pathogenic potential of the strains was checked by performing thermotolerance and osmotolerance assays. Sequencing of the DF3 region resulted in the identification of genotype T4 in all the isolated strains. Moreover, most isolates were thermotolerant or both thermotolerant and osmotolerant and thus were classified as potentially pathogenic strains. To the best of our knowledge, this is the first report on the molecular characterization at the genotype level of Acanthamoeba strains in Venezuela.

  8. Assessment of real-time polymerase chain reaction detection of Acanthamoeba and prognosis determinants of Acanthamoeba keratitis.

    Science.gov (United States)

    Ikeda, Yoshifumi; Miyazaki, Dai; Yakura, Keiko; Kawaguchi, Asako; Ishikura, Ryoko; Inoue, Yoshitsugu; Mito, Tsuyoshi; Shiraishi, Atsushi; Ohashi, Yuichi; Higaki, Shiro; Itahashi, Motoki; Fukuda, Masahiko; Shimomura, Yoshikazu; Yagita, Kenji

    2012-06-01

    To evaluate the diagnostic value of real-time polymerase chain reaction (PCR) for detecting Acanthamoeba in eyes diagnosed with Acanthamoeba keratitis (AK) by conventional tests. In addition, to determine the preoperative prognosis-determining factors in eyes with AK. Retrospective, cross-sectional study. A total of 104 eyes of 103 patients who were diagnosed with AK or with bacterial or bacteria-associated keratitis (BK) by conventional tests. Twenty-nine eyes with AK and 75 eyes with BK were evaluated for Acanthamoeba and bacterial DNA by real-time PCR. The Acanthamoeba copy numbers, bacterial load, and clinical parameters in the patients with AK were assessed for those significantly associated with poor outcome, that is, final visual acuity of Acanthamoeba DNA copy number, bacterial DNA copy number, and odds ratio (OR) for poor prognosis. The detection of amoebic DNA was 50 times more sensitive by real-time PCR than by conventional cyst counting. The Acanthamoeba copy numbers at the first visit (mean: 4.7×10(5)±3.2×10(5) copies) were significantly correlated with the AK stage, and both were significant risk factors for a poor outcome. The Acanthamoeba DNA copy numbers at the first visit and AK stage had a significantly high risk for poor outcome (OR of Acanthamoeba DNA copy per logarithm of copy numbers: 3.48, 95% confidence interval [CI], 1.04-111.63, PAcanthamoeba copy number and AK stage at the first visit were significantly associated with poor outcome. The author(s) have no proprietary or commercial interest in any materials discussed in this article. Copyright © 2012 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  9. Development of an Immunochromatographic Assay Kit Using Fluorescent Silica Nanoparticles for Rapid Diagnosis of Acanthamoeba Keratitis

    OpenAIRE

    Toriyama, Koji; Suzuki, Takashi; Inoue, Tomoyuki; Eguchi, Hiroshi; Hoshi, Saichi; Inoue, Yoshitsugu; Aizawa, Hideki; Miyoshi, Kazutomi; Ohkubo, Michio; Hiwatashi, Eiji; Tachibana, Hiroshi; Ohashi, Yuichi

    2014-01-01

    We developed an immunochromatographic assay kit that uses fluorescent silica nanoparticles bound to anti-Acanthamoeba antibodies (fluorescent immunochromatographic assay [FICGA]) and evaluated its efficacy for the detection of Acanthamoeba and diagnosis of Acanthamoeba keratitis (AK). The sensitivity of the FICGA kit was evaluated using samples of Acanthamoeba trophozoites and cysts diluted to various concentrations. A conventional immunochromatographic assay kit with latex labels (LICGA) was...

  10. Acanthamoeba sohi, n. sp., a pathogenic Korean isolate YM-4 from a freshwater fish

    Science.gov (United States)

    Im, Kyung-il

    2003-01-01

    A new species of Acanthamoeba was isolated from a freshwater fish in Korea and tentatively named Acanthamoeba sp. YM-4 (Korean isolate YM-4). The trophozoites were 11.0-23.0 µm in length and had hyaline filamentous projections. Cysts were similar to those of A. culbertsoni and A. royreba, which were previously designated as Acanthamoeba group III. Acanthamoeba YM-4 can survive at 40℃, and its generation time was 19.6 hr, which was longer than that of A. culbertsoni. In terms of the in vitro cytotoxicity of lysates, Acanthamoeba YM-4 was weaker than A. culbertsoni, but stronger than A. polyphaga. On the basis of the mortality of experimentally infected mice, Acanthamoeba YM-4 was found to be highly virulent. The isoenzymes profile of Acanthamoeba YM-4 was similar to that of A. royreba. An anti-Acanthamoeba YM-4 monoclonal antibody, McAY7, was found to react only with Acanthamoeba YM-4, and not with A. culbertsoni. Random amplified polymorphic DNA marker analysis and RFLP analysis of mitochondrial DNA and of 18S small subunit ribosomal RNA, placed Acanthamoeba YM-4 in a separate cluster on the basis of phylogenetic distances. Thus the Acanthamoeba Korean isolate YM-4 was identified as a new species, and assigned as Acanthamoeba sohi. PMID:14699258

  11. Acanthamoeba keratitis in the south of Sweden.

    Science.gov (United States)

    Skarin, A; Florén, I; Kiss, K; Miörner, H; Stenevi, U

    1996-12-01

    Eight patients with Acanthamoeba keratitis were diagnosed and treated at our clinic between February 1991 and February 1993. Five of these were contact lens wearers, two had suffered recent corneal trauma and one had recently undergone penetrating keratoplasty. The diagnoses were based on both culture and histological examination of biopsy material in three cases, on culture alone in two cases and on histological examination alone in three cases. In all but one primary treatment was Propamidine isethionate and Neomycin/Polymyxin B topically and Ketoconazole orally. Because of poor healing three patients additionally received Paromomycin and Miconazole or Clotrimazol topically; two of these were further treated with Polyhexamethylene biguanide topically. The interval from initial symptoms to accurate diagnoses varied from one to eleven months. In one patient the eye could not be saved; in the remaining patients visual acuity after healing ranged from hand movements to 1.0.

  12. Encystment in Acanthamoeba castellanii: a review.

    Science.gov (United States)

    Lloyd, David

    2014-11-01

    Differentiation of Acanthamoeba castellanii trophozoites involves massive turnover of cellular components and remodelling of organelle structure and function so as to produce a cryptobiotic cell, resistant to desiccation, heat, freezing, and chemical treatments. This review presents a summary of a decade of research on the most studied aspects of the biochemistry of this process, with emphasis on problems of biocide and drug resistances, putative new targets, molecular and cell biology of the process of encystment, and the characteristics of the encysted state. As well as the intrinsic pathogenicity of the organism towards the cornea, and the ability of related species to invade the human brain, its propensity for harbouring and transmitting pathogenic bacteria and viruses is considerable and leads to increasing concerns. The long-term survival and resistance of cysts to drugs and biocides adds another layer of complexity to the problem of their elimination. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. A case of radial keratoneuritis in non-Acanthamoeba keratitis

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    Mutoh T

    2012-09-01

    Full Text Available Tetsuya Mutoh, Yukihiro Matsumoto, Makoto ChikudaDepartment of Ophthalmology, Dokkyo Medical University Koshigaya Hospital, Saitama, JapanAbstract: A case of non-Acanthamoeba keratitis with radial keratoneuritis, which is thought to be pathognomonic for Acanthamoeba keratitis, is reported. A healthy 32-year-old woman with a history of frequent replacement of her contact lenses due to wear was examined at Dokkyo Medical University Koshigaya Hospital (Saitama, Japan and found to have a slight corneal opacity that was accompanied by radial keratoneuritis. Based on both the patient’s clinical findings and past history, the presence of Acanthamoeba keratitis was highly suspected. However, direct light microscopy of corneal scrapings stained by the Parker ink–potassium hydroxide method only found Acanthamoeba-type material in the specimen collected at her initial visit. In all other specimens collected from the patient, no Acanthamoeba was found either when using the same method or when performing cultures of the surgical debridement of the corneal lesion. In addition, topical antifungal eye drops, systemic antifungal drugs, and surgical debridement were also not effective in this case. Since a precise diagnosis could not be made, the patient was treated with topical 0.1% betamethasone sodium, which ultimately resulted in a dramatic improvement of her corneal inflammation. At 23 days after initiation of topical administration of 0.1% betamethasone sodium, visual acuity was 20/250, with a slight corneal opacity noted at the original site of infection. The outcome of the current case suggests that radial keratoneuritis is not always pathognomonic for Acanthamoeba keratitis.Keywords: radial keratoneuritis, non-Acanthamoeba keratitis, topical corticosteroid

  14. Specificity of in vivo confocal cornea microscopy in Acanthamoeba keratitis.

    Science.gov (United States)

    Füst, Ágnes; Tóth, Jeannette; Simon, Gyula; Imre, László; Nagy, Zoltán Z

    2017-01-19

    To report on the presence of 4 different structures visualized by confocal microscopy in patients whose clinical presentation suggested infection by Acanthamoeba. Data and charts of 28 consecutive patients were analyzed in a retrospective study. Four types of structures were recognized by confocal microscopy performed with HRT II Rostock Cornea Module: trophozoites, double-walled cysts, signet rings, and bright spots. The 28 patients (mean age 30.8 years, range 17-61 years, 10 male, 18 female) were divided into 4 groups according to the diagnosis established later by microscopic examination of smear, culture, response to therapy, and the course of keratitis. The 4 groups were Acanthamoeba keratitis (AK), Acanthamoeba suspect (AK-suspect), bacterial keratitis (BK), and fungal keratitis (FK). The rate of patients in AK, AK-suspect, FK, and BK groups where bright spots were found were 100%, 100%, 40%, and 55%, respectively. The sensitivity of presence of bright spots in the in vivo confocal microscopy in Acanthamoeba keratitis was 100% (95% confidence interval [CI] 73.5% to 100.00%) and specificity was 50% (CI 24.7% to 75.4%). When cases where the only signs of Acanthamoeba were bright spots were excluded, and only those cases were counted where any of cysts, trophozoites, or signet rings were also found, the sensitivity was 67% (95% CI 34. 9% to 90.1%) and the specificity was 94% (95% CI 69.8% to 99.8%). The relatively high rate of bright spots in non-Acanthamoeba keratitis challenges the assumption that bright spots seen by confocal microscopy are a specific indication of Acanthamoeba keratitis.

  15. Utilidad de la determinación sérica de microRNA-21 en la enfermedad inflamatoria del colon

    Directory of Open Access Journals (Sweden)

    P. Menéndez

    2013-04-01

    Conclusiones: Es necesario continuar la búsqueda de cuáles son los microRNA más apropiados para que su determinación en suero conlleve una mayor precisión en el establecimiento del diagnóstico y pronóstico de las enfermedades inflamatorias intestinales.

  16. [Acanthamoeba isolation from contact lens solution of contact lens wearers without keratitis].

    Science.gov (United States)

    Watanabe, R; Ishibashi, Y; Hommura, S; Ishii, K

    1994-05-01

    Acanthamoeba keratitis seems to be associated with wearing contact lenses. As controls, we surveyed contact lens wearers without keratitis. Contact lens solutions of 93 persons were examined in order to identify risk factors for contamination by Acanthamoeba. Therefore, the contact lens disinfection system and storage schedules were studied in each case. Acanthamoeba organisms were isolated from 4 specimens (4.3%). The incidence of Acanthamoeba was higher in specimens of soft contact lens solution than in those of hard contact lens solution, and all the Acanthamoeba positive cases had been using tap water.

  17. Acanthamoeba keratitis: is water exposure a true risk factor?

    Science.gov (United States)

    Chynn, E W; Talamo, J H; Seligman, M S

    1997-01-01

    Water exposure has been commonly cited in the literature as a significant risk factor for the development of Acanthamoeba keratitis. The purpose of this study was to test the hypothesis that the incidence of tap and contaminated water exposure in Acanthamoeba keratitis patients is no higher than in the normal contact lens population. We retrospectively reviewed all patients all patients diagnosed with Acanthamoeba keratitis at Massachusetts Eye & Ear Infirmary from 1990-1994, and compared this group to a control population of healthy contact lens wearers assessed by a self-report questionnaire. A history of water exposure was reported by 64% (seven patients) diagnosed with Acanthamoeba keratitis. In comparison, 100% of the control population of healthy contact lens wearers (100 patients) reported comparable water exposure, and 87% of controls reported multiple sources of water exposure. The finding that the incidence of water exposure is actually lower in patients with Acanthamoeba keratitis than in the general contact lens population suggests that water exposure may be less important, and other factors more important in the development of this disease than previously assumed.

  18. In vitro characterization of Acanthamoeba castellanii cytopathic effect.

    Science.gov (United States)

    Taylor, W M; Pidherney, M S; Alizadeh, H; Niederkorn, J Y

    1995-08-01

    This study examined the mechanism of the cytopathic effect (CPE) of Acanthamoeba castellanii on human target cells. Pathogenic Acanthamoeba trophozoites were incubated with human ocular melanoma (OCM1) cells for 30 min, 1 hr, and 3 hr. The amoebae were treated with a calcium ionophore (A23187), phorbol myristate ester (PMA), calcium channel blocker (Bepridil), cytochalasin D, and L-leucyl-L-leucine methyl ester (leu-leu-OMe). Cytolysis was quantified using a spectrophotometric assay. Cocultures of amoeba and cells were also observed by transmission electron microscopy at 1, 2, and 3 hr. Results show that trophozoites formed pseudopodia that made intimate contact with the target cell membrane. Neither amebostomes nor phagocytosis was seen. The calcium ionophore A23187 increased the cytopathic effect of the trophozoites on the cultured OCM1. In contrast, cytochalasin D, Bepridil, and PMA reduced the cytopathic effect. Leu-leu-OMe did not result in killing of Acanthamoeba trophozoites. The results suggest that the cytopathic effect of Acanthamoeba trophozoites involves calcium channels and cytoskeletal elements. There was no evidence of trogocytosis or phagocytosis as sometimes occurs in cytolysis by other free-living amoeba. Although Acanthamoeba-mediated CPE in some ways resembles CPE produced by cytotoxic lymphocytes, the mechanisms are not identical.

  19. Crosslinking and corneal cryotherapy in acanthamoeba keratitis -- a histological study.

    Science.gov (United States)

    Hager, Tobias; Hasenfus, A; Stachon, T; Seitz, B; Szentmáry, N

    2016-01-01

    Acanthamoeba keratitis is rare, but difficult to treat. Penetrating keratoplasty is performed in therapy-resistant cases. Nevertheless, subsequent recurrences occur in 40 % of the cases. In addition to triple-topical therapy (polyhexamid, propamidinisoethionat, neomycin), treatment alternatives are corneal cryotherapy and/or crosslinking (CXL). The aim of our present histological study was to analyze the persistence of acanthamoebatrophozoites and cysts, the persistence of bacteria, and activation of keratocytes in corneas of acanthamoeba keratitis patients following corneal cryotherapy and/or CXL. We analyzed histologically corneal buttons (from penetrating keratoplasties) of nine patients with acanthamoeba keratitis, following corneal cryotherapy (two patients) or a combination of crosslinking and corneal cryotherapy (seven patients), using haematoxilin–eosin, periodic acid Schiff (PAS), Gram and alpha-smooth muscle actin (alpha-SMA) stainings. Acanthamoeba trophozoites persisted in three corneas after cryotherapy and CXL. Cysts persisted in one of two corneas following corneal cryotherapy and in six of seven corneas after a combination of CXL and cryotherapy. One cornea showed positive Gram staining, but there were no alpha-SMA positive keratocytes in any of the corneas. Crosslinking and corneal cryotherapy have only limited impact on killing of acanthamoeba trophozoites, cysts, or bacteria. Corneal cryotherapy and CXL did not stimulate myofibroblastic transformation of keratocytes.

  20. Practice patterns and opinions in the treatment of acanthamoeba keratitis

    Science.gov (United States)

    Oldenburg, Catherine E.; Acharya, Nisha R.; Tu, Elmer Y.; Zegans, Michael E.; Mannis, Mark J.; Gaynor, Bruce D.; Whitcher, John P.; Lietman, Thomas M.; Keenan, Jeremy D.

    2011-01-01

    Purpose Management of acanthamoeba keratitis remains challenging for ophthalmologists. We conducted a survey of members of the Cornea Society to elicit expert opinions on the diagnosis and treatment of acanthamoeba keratitis. Methods An online survey was sent to all subscribers of the Cornea Society kera-net listserv. Descriptive statistics were performed. Results Eighty-two participants completed the online survey. Of the 82 respondents, 76.8% included the combination of clinical examination and culture in their diagnostic strategy, and 43.9% used confocal microscopy. Most respondents (97.6%) had used combination therapy with multiple agents to treat acanthamoeba keratitis at some point in the past, whereas a smaller proportion (47.6%) had ever used monotherapy. Respondents most commonly chose PHMB as the ideal choice for monotherapy (51.4%), and dual therapy with a biguanide and diamidine as the ideal choice for combination therapy (37.5%). The majority of respondents (62.2%) reported using topical corticosteroids at least some of the time for acanthamoeba keratitis. Keratoplasty was an option considered by most respondents (75.6%), although most (85.5%) would only perform surgery after medical treatment failure. Conclusion There was a wide range of current practice patterns for the diagnosis and treatment of acanthamoeba keratitis. The lack of sufficiently-powered comparative effectiveness studies and clinical trials makes evidenced-based decision making for this disease difficult. PMID:21993459

  1. Protein profiles and immunoreactivities of Acanthamoeba morphological groups and genotypes.

    Science.gov (United States)

    Pumidonming, Wilawan; Koehsler, Martina; Leitsch, David; Walochnik, Julia

    2014-11-01

    Acanthamoeba is a free-living protozoan found in a wide variety of habitats. A classification of Acanthamoeba into currently eighteen genotypes (T1-T18) has been established, however, data on differences between genotypes on the protein level are scarce. The aim of this study was to compare protein and immunoreactivity profiles of Acanthamoeba genotypes. Thirteen strains, both clinical and non-clinical, from genotypes T4, T5, T6, T7, T9, T11 and T12, representing three morphological groups, were investigated for their protein profiles and IgG, IgM and IgA immunoreactivities. It was shown that protein and immunoreactivity profiles of Acanthamoeba genotypes T4, T5, T6, T7, T9, T11 and T12 are clearly distinct from each other, but the banding patterns correlate to the morphological groups. Normal human sera revealed anti-Acanthamoeba antibodies against isolates of all investigated genotypes, interestingly, however only very weak IgM and virtually no IgA immunoreactivity with T7 and T9, both representing morphological group I. The strongest IgG, IgM and IgA immunoreactivities were observed for genotypes T4, T5 and T6. Differences of both, protein and immunological patterns, between cytopathic and non-cytopathic strains, particularly within genotype T4, were not at the level of banding patterns, but rather in expression levels. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Miraflow, Soft Contact Lens Cleaner: Activity Against Acanthamoeba Spp.

    Science.gov (United States)

    Kobayashi, Takeshi; Higuchi-Watanabe, Narumi; Shiraishi, Atsushi; Uno, Toshihiko; Ohashi, Yuichi

    2015-07-01

    Miraflow is a cleaner for soft contact lens which contains 20% isopropyl alcohol. The purpose of this study was to determine the activity against Acanthamoeba trophozoites and cysts for Miraflow. In addition, to determine the activity of combined Miraflow and multipurpose solutions (MPSs) against Acanthamoeba cysts. Two simulated-use studies were conducted. The significance in the log reduction in the number of trophozoites and cysts of A. castellanii strains ATCC 50514 and ATCC 50370 or A. polyphaga ATCC 30461 after exposure to Miraflow alone was determined by the Spearman-Karber method. To examine the activity against Acanthamoeba of combined Miraflow and an MPS, the log reduction in the number of cysts after a 1-min exposure to Miraflow followed by a 4-hr exposure to MPS (ReNu fresh) was also determined. Short-time exposure of 30 sec to Miraflow demonstrated activity against the Acanthamoeba trophozoites. However, a 1-min treatment was only relatively effective (1.1 log reduction) against the cysts of A. castellanii ATCC 50514, but no statistically significant reduction was observed for the cysts of the other 2 strains. The combined use with Miraflow and MPS demonstrated activity against the cysts, and a 3.0, 1.0, or 1.5 log reduction in the numbers was obtained for A. castellanii ATCC 50514, A. castellanii ATCC 50370, and A. polyphaga ATCC 30461, respectively. Exposure to combined Miraflow and MPS resulted in reductions in the number of Acanthamoeba cysts.

  3. [Amoebas of the genus acanthamoeba as an etiological factor of keratitis].

    Science.gov (United States)

    Kosik-Bogacka, Danuta; Czepita, Damian; Łanocha, Natalia

    2010-01-01

    The aim of the paper was to describe the role of amoebas of the genus Acanthamoeba in the pathogenesis of keratitis. A review of literature concerning the role of amoebas of the genus Acanthamoeba in the pathogenesis of keratitis was done. Amoebas of the genus Acanthamoeba can be widely found in soil, air, fresh as well as saline water and as facultative parasites in humans. Amoebas of this genus are responsible for the creation of Acanthamoeba keratitis. In this paper the latest data concerning the epidemiology, diagnostic and treatment of Acanthamoeba keratitis have been cited and disscused. 1. Keratitis induced by amoebas of the genus Acanthamoeba are characterized as acute and difficult to treat. 2. Acanthamoeba keratitis occurs in recent years more often due to the fact that more people wear contact lenses.

  4. Acanthamoeba keratitis: a clinicopathologic case report and review of the literature.

    Science.gov (United States)

    Knickelbein, Jared E; Kovarik, Jessica; Dhaliwal, Deepinder K; Chu, Charleen T

    2013-05-01

    The immune response elicited by corneal Acanthamoeba infection remains incompletely understood. The infected cornea removed from a patient with Acanthamoeba keratitis during therapeutic penetrating keratoplasty was analyzed by immunohistochemistry. Heavy infiltration of neutrophils and, to a lesser extent, macrophages was observed throughout the cornea with both cell types in direct apposition to Acanthamoeba parasites. While T and B cells were identified in the corneal stroma, none were seen in direct proximity to Acanthamoeba parasites. Natural killer (NK) cells were absent from the cornea. These results demonstrate that neutrophils and macrophages of the innate immune system predominate in the host response against Acanthamoeba infection of the human cornea, confirming the relevance of animal models of Acanthamoeba keratitis that recapitulate these findings. Lymphocytes appear to be excluded from regions of the cornea containing Acanthamoeba parasites, despite the presence of a corneal lymphocytic response in this case, suggesting inhibition of lymphocyte chemotaxis toward the parasite. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. Nuevas consideraciones fisiopatológicas sobre el síndrome de respuesta inflamatoria sistémica relacionada con la sepsis

    Directory of Open Access Journals (Sweden)

    Vivian R. Mena Miranda

    1996-04-01

    Full Text Available El shock séptico constituye una de las primeras causas de morbilidad y mortalidad en las unidades de cuidados intensivos y forma parte de los estadios evolutivos la respuesta inflamatoria sistémica (SRIS en relación con la infección, que fueron modificados por Jaffari para su aplicación en la edad pediátrica. Está relacionado con la exposición del organismo a agentes exógenos y/o mediadores endógenos, que producen una inadecuada perfusión hística con alteración en el consumo de oxígeno, en la permeabilidad vascular y la aparición de trastornos hemodinámicos que comprometen la vida del paciente. Se considera que el mediador central en el shock séptico es el factor de necrosis tumoral-a(FNT- a, aunque también responden de forma descontrolada otras citocinas, los polimorfonucleares, el sistema de contacto, el fibrinolítico, el de la coagulación, así como otras sustancias endógenas. El conocimiento de su fisiopatología hace posible el diagnóstico y tratamiento precoz, sobre todo en los grupos de riesgo, y la reducción de la mortalidad en las unidades de terapia intensiva por esta afección.The septic shock is one of the first causes of morbidity and mortality in intensive care units, and the systemic inflammatory response syndrome (SIRS is a part of the evolutive stages related to the infection, that were modified by Jaffari for its application in the pediatric age. Septic shock is related with the organism exposition to exogenous agents, and/or endogenous mediators that produce an inadequate histic perfusion with alteration in oxygen consumption, in vascular permeability, and the presentation of hemodynamic disorders that compromise the patient's life. It is considered that the main mediator in septic shock is the tumoral necrosis factor - (TBF- , although other cytosines also reply in an uncontrolled fashion, the polymorphonuclears, the contact system, the fibrinolytic, the coagulation one, as well as other endogenous

  6. Acanthamoeba keratitis: an emerging disease gathering importance worldwide?

    Science.gov (United States)

    Lorenzo-Morales, Jacob; Martín-Navarro, Carmen María; López-Arencibia, Atteneri; Arnalich-Montiel, Francisco; Piñero, José E; Valladares, Basilio

    2013-04-01

    Acanthamoeba keratitis (AK) is increasingly being recognized as a severe sight-threatening ocular infection worldwide. Although contact lens wear is the leading risk factor for AK, Acanthamoeba parasites are also an important cause of keratitis in non-contact lens wearers. Diagnosis of AK is challenging, and the available treatments are lengthy and not fully effective against all strains. The pathogenesis of Acanthamoeba is still under study, and the identification of the key factors involved in this process should be useful for the development of fully effective therapies. This review focuses on recent developments on AK pathogenesis and diagnosis as well as novel strategies for the evaluation of anti-amoebic agents that could be applied in the near future against these pathogens. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Acanthamoeba T4 genotype associated with keratitis infections in Tunisia.

    Science.gov (United States)

    Dendana, F; Sellami, H; Trabelsi, H; Neji, S; Cheikhrouhou, F; Makni, F; Ayadi, A

    2013-01-01

    Acanthamoeba keratitis (AK) is a sight-threatening infection. We report five cases of AK diagnosed from 2005 to 2009 in the Laboratory of Parasitology-Mycology at Habib Bourguiba Sfax Hospital, Tunisia. All were associated with improper care of contact lenses (rinsing of contact lenses with tap water and inappropriate cleaning) and lens storage. The patients displayed different clinical presentations: corneal inflammation, corneal ulceration, and corneal abscess. The diagnosis was made after direct examination, culture, and polymerase chain reaction amplification with specific primers. The genotype classification was based on the highly variable DF3 region in the 18S rRNA gene. This is the first study characterizing Acanthamoeba genotype in Tunisia and North Africa. All Acanthamoeba isolates were associated to the T4 genotype. Three different DF3 sequence types were related to AK infections T4/10, T4/15, and T4/16.

  8. Enucleation following treatment with intravenous pentamidine for Acanthamoeba sclerokeratitis

    Directory of Open Access Journals (Sweden)

    Rebecca A Kuennen

    2010-09-01

    Full Text Available Rebecca A Kuennen, Reynell Harder Smith, Thomas F Mauger, Elson CraigDepartment of Ophthalmology, The Ohio State University, Columbus, Ohio, USAPurpose: To describe the course and outcome of treatment of advanced Acanthamoeba sclerokeratitis with intravenous pentamidine.Methods: A case of advanced Acanthamoeba sclerokeratitis was resistant to conventional therapy and was treated with intravenous pentamidine. The eye was later removed due to incapacitating pain.Results: The eye showed Acanthamoeba organisms within the cornea and evidence of acute and chronic inflammation throughout the remainder of the eye. The patient has survived without orbital recurrence for 2 years.Conclusions: This case demonstrates late inflammation with active Acanthameoba keratitis following systemic pentamidine therapy.Keywords: keratitis, scleritis

  9. Pathogenic assays of acanthamoeba belonging to the t4 genotype.

    Directory of Open Access Journals (Sweden)

    Hamed Mirjalali

    2013-12-01

    Full Text Available Acanthamoeba genus is introduced as opportunistic and cosmopolitan parasite. Monkey and wistar rat are appropriate models for experimental study on Acanthamoeba infection. In this study Acanthamoeba spp. were isolated from hot spring (HS, windows dust (WD and a corneal sample of keratitis patient (KP and their pathogenicity surveyed by in vitro and in vivo tests.Isolates of Acanthamoeba were cultivated axenically for 12 months in PYG medium. Overall, 30 wistar rats, in 6 equal groups were used for developing experimental Acanthamoeba keratitis (AK and Granulomatous Amoebic Encephalitis (GAE. The Keratitis and Granulomatous Encephalitis experiments were performed by intrastromal and intranasal inoculation of Acanthamoeba cysts, respectively. Pathogenicity of the three isolates was also evaluated by in vitro test using osmotolerance and temperature tolerance assays. Identification of genotypes were performed by PCR technique and sequencing.None of the isolates could perform AK and GAE in wistar rats, although all isolates were described as T4 genotype. Isolates obtained from KP and WD could grow only in 30 °C, but not in 37 °C and 40 °C. On the other hand, HS isolate grew in 30 °C and 37 °C but not in 40 °C. Moreover, all of isolate grew in 0.5 M mannitol but not in 1 M and 1.5 M.T4 isolates with a long-term axenic culture and different factors related to host and parasite may play role in pathogenicity of these free-living amoebae.

  10. IL-17A-mediated protection against Acanthamoeba keratitis.

    Science.gov (United States)

    Suryawanshi, Amol; Cao, Zhiyi; Sampson, James F; Panjwani, Noorjahan

    2015-01-15

    Acanthamoeba keratitis (AK) is a very painful and vision-impairing infection of the cornea that is difficult to treat. Although past studies have indicated a critical role of neutrophils and macrophages in AK, the relative contribution of the proinflammatory cytokine, IL-17A, that is essential for migration, activation, and function of these cells into the cornea is poorly defined. Moreover, the role of the adaptive immune response, particularly the contribution of CD4(+) T cell subsets, Th17 and regulatory T cells , in AK is yet to be understood. In this report, using a mouse corneal intrastromal injection-induced AK model, we show that Acanthamoeba infection induces a strong CD4(+) T effector and regulatory T cell response in the cornea and local draining lymph nodes. We also demonstrate that corneal Acanthamoeba infection induces IL-17A expression and that IL-17A is critical for host protection against severe AK pathology. Accordingly, IL-17A neutralization in Acanthamoeba-infected wild-type mice or Acanthamoeba infection of mice lacking IL-17A resulted in a significantly increased corneal AK pathology, increased migration of inflammatory cells at the site of inflammation, and a significant increase in the effector CD4(+) T cell response in draining lymph nodes. Thus, in sharp contrast with other corneal infections such as herpes and Pseudomonas aeruginosa keratitis where IL-17A exacerbates corneal pathology and inflammation, the findings presented in this article suggest that IL-17A production after Acanthamoeba infection plays an important role in host protection against invading parasites. Copyright © 2015 by The American Association of Immunologists, Inc.

  11. Confocal microscopy as an early relapse marker for acanthamoeba keratitis.

    Science.gov (United States)

    Daas, Loay; Viestenz, Arne; Schnabel, Philipp Albert; Fries, Fabian N; Hager, Tobias; SzentmÁry, Nora; Seitz, Berthold

    2018-01-01

    Acanthameoba keratitis is a serious ophthalmological condition with a potentially vision-threatening prognosis. Early diagnosis and recognition of relapse, and the detection of persistent Acanthamoeba cysts, are essential for informing the prognosis and managing the condition. We suggest the use of in vivo confocal microscopy not only to identify the early signs of relapse after keratoplasty in patients with Acanthamoeba keratitis, but also as an additional follow-up tool after antimicrobial crosslinking. This study shows that in vivo confocal microscopy is, in experienced hands, a quick and reliable diagnostic tool. Clin. Anat. 31:60-63, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  12. DESARROLLO DE UN KIT MOLECULAR PARA LA DETECCION DE GENES DE VIRULENCIA POR PCR MULTIPLE EN BIOPSIAS GASTRICAS DE PACIENTES INFECTADOS CON HELLCOBACTER PYLORL

    OpenAIRE

    GARCIA CANCINO, APOLINARIA

    2008-01-01

    • Origen: La infección por Helicobacter pylori constituye en la actualidad un problema importante en salud pública, por el tipo de patologías que se asocian con este microorganismo, por el costo que le significa al sistema de salud público y privado, especialmente, por el riesgo para el paciente si persiste la infección con cepas de mayor poder patógeno. La infección por H. pylori se asocia con patologías gastroduodenales inflamatorias crónicas, linfoma MALT y cáncer gástrico. El principal...

  13. Infection of Acanthamoeba castellanii by Chlamydia pneumoniae.

    Science.gov (United States)

    Essig, A; Heinemann, M; Simnacher, U; Marre, R

    1997-04-01

    Chlamydia pneumoniae is an intracellular respiratory pathogen, which, similar to Legionella, might have developed mechanisms to escape the intracellular bactericidal activity of both human host cells and amoeba. We therefore investigated the intracellular growth and survival of C. pneumoniae in Acanthamoeba castellanii by using cell culture, immunofluorescence microscopy, and electron microscopy. A castellanii was incubated with purified elementary bodies of C. pneumoniae TW 183 at a concentration of 10(6) inclusion-forming units (IFU)/ml to give a ratio of approximately 1 IFU of C. pneumoniae per amoeba. Quantitative determination of chlamydial growth within A. castellanii revealed viable and infective C. pneumoniae in the range of 10(4) to 10(5) IFU/ml between days 7 and 14 postinfection. Immunofluorescence analysis and transmission electron microscopy with subsequent immunogold staining confirmed evidence of infection of the amoebae by C. Pneumoniae and additionally revealed that C. pneumoniae entered the typical growth cycle. Our results show that amoebae allow the survival of C. pneumoniae, suggesting that amoebae may serve as an additional reservoir for Chlamydia or Chlamydia-related organisms.

  14. Differential localization of Acanthamoeba myosin I isoforms

    Science.gov (United States)

    1992-01-01

    Acanthamoeba myosins IA and IB were localized by immunofluorescence and immunoelectron microscopy in vegetative and phagocytosing cells and the total cell contents of myosins IA, IB, and IC were quantified by immunoprecipitation. The quantitative distributions of the three myosin I isoforms were then calculated from these data and the previously determined localization of myosin IC. Myosin IA occurs almost exclusively in the cytoplasm, where it accounts for approximately 50% of the total myosin I, in the cortex beneath phagocytic cups and in association with small cytoplasmic vesicles. Myosin IB is the predominant isoform associated with the plasma membrane, large vacuole membranes and phagocytic membranes and accounts for almost half of the total myosin I in the cytoplasm. Myosin IC accounts for a significant fraction of the total myosin I associated with the plasma membrane and large vacuole membranes and is the only myosin I isoform associated with the contractile vacuole membrane. These data suggest that myosin IA may function in cytoplasmic vesicle transport and myosin I-mediated cortical contraction, myosin IB in pseudopod extension and phagocytosis, and myosin IC in contractile vacuole function. In addition, endogenous and exogenously added myosins IA and IB appeared to be associated with the cytoplasmic surface of different subpopulations of purified plasma membranes implying that the different myosin I isoforms are targeted to specific membrane domains through a mechanism that involves more than the affinity of the myosins for anionic phospholipids. PMID:1447297

  15. Legionella pneumophila decreases velocity of Acanthamoeba castellanii.

    Science.gov (United States)

    Mengue, Luce; Richard, Freddie-Jeanne; Caubet, Yves; Rolland, Steven; Héchard, Yann; Samba-Louaka, Ascel

    2017-12-01

    Acanthamoeba castellanii is a free-living amoeba commonly found in aquatic environment. It feeds on bacteria even if some bacteria resist amoebal digestion. Thus, A. castellanii is described as a Trojan horse able to harbor pathogenic bacteria. L. pneumophila is one of the amoeba-resisting bacteria able to avoid host degradation by phagocytosis and to multiply inside the amoeba. When infecting its host, L. pneumophila injects hundreds of effectors via a type IV secretion system that change physiology of the amoeba to its profit. In this study, we assess mobility of A. castellanii upon infection with L. pneumophila. Electron-microscopy analysis of amoebae revealed a reduction of acanthopodia on cells infected with L. pneumophila. Analysis of velocity showed that migration of A. castellanii infected with L. pneumophila was significantly impaired compare to uninfected cells. Taken together, infection with L. pneumophila could prevent formation of cytoplasmic extensions such as acanthopodia with consequences on the shape, adherence and mobility of A. castellanii. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Epidemiological typing of Acanthamoeba strains isolated from keratitis cases in Belgium.

    Science.gov (United States)

    De Jonckheere, J F

    2003-01-01

    From the corneas of nine keratitis patients and from their contact lenses, contact lens boxes and saline solutions, 15 strains of Acanthamoeba have been isolated. An Acanthamoeba strain was isolated from the swimming pool where one of the patients swam, while in the tapwater of the houses of three patients investigated, no Acanthamoeba could be detected. All the Acanthamoeba isolates from the cornea belong to genotype T4, but are different subtypes of T4. The Acanthamoeba detected on the contact lenses (and/or associated paraphernalia) of a patient are of the same subtype as that isolated from the cornea. The only Acanthamoeba strain isolated from a contact lens which was not related to an Acanthamoeba keratitis infection proved to be another genotype. A strain of Hartmannella from a cornea and two vahlkampfiids isolated from contact lenses had no connection with keratitis. This study confirms that, as found elsewhere, only Acanthamoeba genotype T4 of the 12 known Acanthamoeba genotypes is responsible for keratitis in Belgium. Most cases of Acanthamoeba keratitis cases are due to poor hygiene in the treatment (cleaning and storage) of contact lenses.

  17. Rapid and sensitive diagnosis of Acanthamoeba keratitis by loop-mediated isothermal amplification.

    Science.gov (United States)

    Ge, Z; Qing, Y; Zicheng, S; Shiying, S

    2013-11-01

    A loop-mediated isothermal amplification (LAMP) assay was developed for the detection of Acanthamoeba. The sensitivity of the LAMP assay was tested using different copies of positive DNA. The specificity of the assay was tested using DNA extracted from Acanthamoeba, Pseudomonas aeruginosa, Candida albicans, herpes simplex virus-1 and human corneal epithelial cells. Its effectiveness was evaluated and compared with culture, corneal smear examination and real-time PCR in corneal samples from mice with Acanthamoeba keratitis. We also tested three corneal samples from patients with suspected Acanthamoeba or fungal infection using LAMP. Loop-mediated isothermal amplification was confirmed to be very sensitive, with the lowest detection limit being ten copies/tube of Acanthamoeba DNA. The LAMP primers only amplified Acanthamoeba DNA. During the development of Acanthamoeba keratitis in mice, almost all of the positive rates of LAMP at each time post-infection were higher than those of culture or corneal smear examination. The total positive rate of LAMP was significantly higher than those of culture and corneal smear examination (p Acanthamoeba keratitis tested positive for Acanthamoeba using LAMP along with culture or corneal smear examination, whereas the other suspected fungal keratitis tested negative. The LAMP assay is a simple, rapid, highly specific and sensitive method for the diagnosis of keratitis caused by Acanthamoeba. © 2013 The Authors Clinical Microbiology and Infection © 2013 European Society of Clinical Microbiology and Infectious Diseases.

  18. In vitro Effect of Monosaccharides on the Virulence of Acanthamoeba Isolated from Patients with Amoebic Keratitis

    Directory of Open Access Journals (Sweden)

    Y. Maroofi

    2007-04-01

    Full Text Available Introduction & Objective: Acanthamoeba is free-living amoeba that is found in soil, water, air as well as in human pharynx. Acanthamoeba is causative agent of granulomatose amoebic encephalitis (GAE in immunosuppressed and AIDS individuals and amoebic keratitis in people who use the lens. Pathogenic species of Acanthamoeba have protein receptors named mannose binding protein (MBP. Acanthamoeba via MBP adhere to the glycoproteins included mannose. Acanthamoeba adhesion to the target cells induces a protease secretion is called mannose inducing protein-133 (MIP-133. Exogense mannose can inhibit the adherence of Acanthamoeba; also, it can increase the cytopathatic effect (CPE through increase the secretion of MIP-133. In the present work, the effect of monosaccharides on the virulance of Acanthamoeba isolated from patient with amoebic keratitis, in HeLa cell culture was investigated.Materials & Methods: The isolates were cultured in HeLa cell culture, then 100, 50, 10, 1 and 0.1 mM of galactose, glucose and mannose were added to plates. Plates were observed with invert microscope in 8, 16, 32, 48, and 72 hours after culture.Results: Data implicated that mannose (100 mM showed the highest effect on increasing cytopathy of Acanthamoeba in HeLa cell culture. Meanwhile, galactose (100 mM increased the virulence of Acanthamoeba in the cell culture after 32 hours.Conclusion: Adding mannose and galactose to HeLa cell culture contain Acanthamoeba can increase the virulence of the parasite significantly.

  19. The role of domestic tap water in Acanthamoeba contamination in contact lens storage cases in Korea

    Science.gov (United States)

    Jeong, Hae Jin

    2005-01-01

    A survey was carried out from August to December 2004 in Pusan, Korea to document the presence of free-living amoeba (FLA), including the genus Acanthamoeba, in both contact lens storage cases and domestic tap water. Acanthamoeba was isolated from 5 (4.2%) in 120 contact lens storage cases. Four house tap water samples from residents, whose contact lens storage cases had been contaminated by Acanthamoeba, were also found to be contaminated with Acanthamoeba. Therefore, the contamination rate of FLA and Acanthamoeba in domestic tap water was investigated in order to examine the role of domestic tap water in Acanthamoeba contamination of contact lens storage cases. FLA and Acanthamoeba were identified in 97 (46.8%) and 16 (7.7%) of the 207 domestic tap water samples, respectively. There were no significant differences between the contamination rates of FLA in tap water according to the filtration plant of origin. No FLA was detected in the tap water directly supplied by the water purification plants. Water storage tanks appear to promote FLA colonization, including Acanthamoeba, in domestic tap water. This increases the risk of Acanthamoeba contamination in contact lens storage cases as well as increasing the risk of Acanthamoeba keratitis. PMID:15951638

  20. Effects of Grazing by the Free-Living Soil Amoebae Acanthamoeba castellanii, Acanthamoeba polyphaga, and Hartmannella vermiformis on Various Bacteria

    Science.gov (United States)

    Weekers, Peter H. H.; Bodelier, Paul L. E.; Wijen, John P. H.; Vogels, Godfried D.

    1993-01-01

    Cultures of 10 different bacteria were used to serve as food sources for axenically grown Acanthamoeba castellanii, Acanthamoeba polyphaga, and Hartmannella vermiformis. The nonpigmented enterobacteriaceae Escherichia coli K-12 and Klebsiella aerogenes appeared to be excellent feed to all three amoebae. Hardly any growth or ammonium production was observed in tests with Chromatium vinosum and Serratia marcescens, which share the presence of pigmented compounds. Distinct differences in net ammonium production were detected and were correlated to the amoebal growth yield. In general, growth of amoebae and ammonium production increased in the order A. polyphaga, A. castellanii, and H. vermiformis. PMID:16349000

  1. Systemic immune response to Acanthamoeba keratitis in the Chinese hamster.

    Science.gov (United States)

    Van Klink, F; Leher, H; Jager, M J; Alizadeh, H; Taylor, W; Niederkorn, J Y

    1997-12-01

    Recrudescence is a common and troubling feature of Acanthamoeba keratitis and suggests that corneal infection with this organism fails to stimulate the systemic immune apparatus. The present study examined the cell-mediated and humoral immune responses to Acanthamoeba keratitis in the Chinese hamster. Corneal infection with A. castellanii failed to induce either delayed-type hypersensitivity (DTH) or serum IgG antibody against parasite antigens. The failure to induce cell-mediated and humoral immunity did not result in anergy or tolerance since subsequent intramuscular (i.m.) immunization with parasite antigens elicited robust DTH and IgG antibody responses. The inability of corneal infections to induce primary cell-mediated immune responses was due to the absence of resident antigen-presenting cells in the central cornea because induction of Langerhans cell (LC) migration into the central cornea prior to infection with Acanthamoeba promoted the development of parasite-specific DTH. Although the presence of resident LC did not promote the development of a primary humoral immune response, subsequent i.m. immunization elicited heightened parasite-specific IgG antibody production which was indicative of an anamnestic response. Collectively, the results indicate that in the absence of resident antigen-presenting cells, corneal infection with Acanthamoeba fails to stimulate primary cell-mediated or humoral immunity. Induction of peripheral LC into the central corneal epithelium promotes the development of parasite-specific DTH, but does not exacerbate corneal disease.

  2. Acanthamoeba keratitis. Contact lens and noncontact lens characteristics.

    Science.gov (United States)

    Chynn, E W; Lopez, M A; Pavan-Langston, D; Talamo, J H

    1995-09-01

    To identify potential differences in time to diagnosis and final visual outcome between contact lens and noncontact lens users with Acanthamoeba keratitis. Prior studies have shown early diagnosis and therapy to be related to outcome but have not analyzed differences among patients with and without contact lenses. A retrospective analysis of 11 consecutive cases (involving 13 eyes) of Acanthamoeba keratitis diagnosed at one institution over a 3-year period. Mean time to diagnosis was significantly longer in noncontact lens users versus those who wore contact lenses (mean, 5.8 versus 3.3 weeks). Fifty percent of patients who did not wear contact lenses had a poor outcome (visual acuity worse than 20/40 or penetrating keratoplasty) versus 14% of patients who wore contact lenses. Diagnoses were made later in patients without contact lenses, and these patients had a worse visual outcome than those with Acanthamoeba keratitis who wore contact lenses. All patients with unresponsive microbial keratitis, even those without contact lens use, should be evaluated for Acanthamoeba.

  3. Diagnosis and successful medical treatment of Acanthamoeba keratitis.

    Science.gov (United States)

    D'Aversa, G; Stern, G A; Driebe, W T

    1995-09-01

    To identify the methods that result in timely diagnosis and effective treatment of Acanthamoeba keratitis. We retrospectively reviewed the medical records of 12 consecutive patients whom we treated for culture-proved Acanthamoeba keratitis in 14 eyes. Contact lenses were worn in 13 of 14 affected eyes and substandard methods were often used to care for them. The diagnosis was established in all patients by laboratory analysis of corneal scrapings; corneal biopsies were not required. Acanthamoeba organisms were identified on smears from 12 of 14 eyes with use of standard, nonfluorescent stains and recovered in culture from all patients by inoculating scrapings on nonnutrient agar overlaid with Escherichia coli. Eleven of 14 eyes were medically cured with a combination of antiamebic drugs, most commonly propamidine isethionate, neomycin sulfate, and clotrimazole. Topical corticosteroids were used in only one patient. Two of the three eyes that required therapeutic keratoplasty were not treated before surgery according to our usual protocol; the third required keratoplasty for treatment of a severe bacterial superinfection. Twelve of 14 eyes recovered 20/50 or better visual acuity. Bacterial superinfections were a serious problem, with a total of six superinfections occurring in three treated eyes. With timely diagnosis and medical treatment with a combination of antiamebic drugs and avoidance of topical corticosteroids, most cases of Acanthamoeba keratitis can be cured, with an excellent prognosis for visual recovery.

  4. Characterization of a plasminogen activator produced by Acanthamoeba castellanii.

    Science.gov (United States)

    Mitra, M M; Alizadeh, H; Gerard, R D; Niederkorn, J Y

    1995-07-01

    Serine proteases play an important role in a diverse array of biological processes, including embryogenesis, metastasis, angiogenesis, thrombolysis and tissue invasion by certain parasites. The latter observation prompted us to explore the possibility that the tissue-invasive ocular parasite Acanthamoeba castellanii elaborates one or more serine proteases. Acanthamoeba sp. are pathogenic free-living amoebae that can produce an invasive, blinding inflammatory disease of the cornea, termed Acanthamoeba keratitis. The present study reports the preliminary purification and characterization of a novel plasminogen activator from an ocular isolate of A. castellanii. The parasite-derived enzyme has a molecular mass of approx. 40 kDa and produces a single band of lysis on fibrinogen-agarose zymographs. Activity of the enzyme is completely inhibited by treatment with diisopropylfluorophosphate, indicating that it is a serine protease. The parasite-derived serine protease is not inhibited by amiloride which is a strong inhibitor of urokinase-type plasminogen activator. Additionally, the enzyme is not inhibited by plasminogen activator inhibitor-1 which is the primary physiological inhibitor of both urokinase and tissue-type plasminogen activator. It does not cross-react with antibodies specific for human urokinase or tissue-type plasminogen activator. The parasite-derived enzyme activates plasminogen from several mammalian species, including human, cow and pig. Thus, it is possible that this parasite-derived serine protease contributes to the pathogenesis of Acanthamoeba keratitis.

  5. Comparison of axenic and monoxenic media for isolation of Acanthamoeba.

    Science.gov (United States)

    Penland, R L; Wilhelmus, K R

    1997-04-01

    Acanthamoeba is a genus of ubiquitous, free-living amebae that can be difficult to isolate by standard microbiologic techniques. We retrospectively reviewed the laboratory records of patients with ocular acanthamoebic infection for the period from January 1973 to June 1996 and found that Acanthamoeba isolates were recovered from 73, 71, and 70% of clinical specimens inoculated onto buffered charcoal-yeast extract agar (BCYE), nonnutrient agar with live or dead Escherichia coli, and tryptic soy agar (TSA) with horse or sheep blood, respectively. We then prospectively compared the recovery of a corneal isolate of Acanthamoeba on commercial media from Remel and BBL (TSA with 5% sheep blood, TSA with 5% horse blood, TSA with 5% rabbit blood, V agar, chocolate agar, BCYE, and selective BCYE with polymyxin B, anisomycin, and vancomycin) and on axenic and monoxenic media prepared with live or dead bacteria (Enterobacter aerogenes, E. coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Serratia marcescens, Staphylococcus aureus, and Stenotrophomonas maltophilia). Good recovery of trophozoites was obtained on BCYE, TSA with rabbit blood, TSA with horse blood, and Remel TSA with sheep blood. BBL TSA with horse blood or rabbit blood provided good recovery of cysts. All species of live or dead bacteria yielded good recovery of trophozoites; however, only nonnutrient agar with live P. aeruginosa, live E. aerogenes, or live S. maltophilia gave good recovery of cysts. TSA with either rabbit blood or horse blood, BCYE, and nonnutrient agar prepared with live P. aeruginosa, E. aerogenes, or S. maltophilia offer optimal recovery of Acanthamoeba.

  6. [Keratitis caused by Acanthamoeba in patients with contact lenses].

    Science.gov (United States)

    de Miguel, I; Ferrando, R; Santan, O E; Martín-Sánchez, A M

    1999-11-01

    Keratitis by Acanthamoeba is a severe infectious complication which may be derived from the use and bad preservation of contact lens. This disease la increasingly more frequent and rapid diagnosis and treatment condition the posterior evolution of the disease. The cases of 2 contact lens waters who developed keratitis by Acanthamoeba are presented. The diagnostic methods and treatment are commented upon. Keratitis by Acanthamoeba was diagnosed in 2 patients following analysis of corneal scrapings and of the saline solution used for lens maintenance. Trophozoites and cystes of this parasite were observed in all the samples processed. The evolution was good in the patient treated at 15 days after initiation of the symptoms. However, the evolution was very bad in the patient who delayed in initiating the amebicide treatment. Penetrating keratoplasty was performed in both patients. Specific treatment with derivates of propamidine implemented early may avoid severe ocular complications. As prophylaxis for contact lens users, it is recommended that the contact lens be maintained clean and correctly care for, and the use of home-made saline solutions which are easily contaminated by Acanthamoeba, should be avoided.

  7. [Morphological characteristics in corneal smear of acanthamoeba keratitis].

    Science.gov (United States)

    Wang, Zhi-qun; Li, Ran; Zhang, Chen; Luo, Shi-yun; Sun, Xu-guang; Jin, Xiu-ying

    2010-05-01

    To study the morphological characteristics in corneal smear of acanthamoeba keratitis. Experimental study. From May 1991 to December 2007, in Department of Microbiology, Beijing Institute of Ophthalmology, Beijing Tongren Hospital, 159 cases with acanthamoeba keratitis were analyzed for the laboratory results and clinical data. Giemsa's stained smear and wet-mount preparation of 159 cases were observed, all the results of cytology be photographed as the records. Among the 159 cases with acanthamoeba keratitis, 131 patients (82.4%) were positive on smear, and 110 cases (69.2%) were positive in culture of amoeba. The detection positive rate of smear was apparently higher than culture. Typical trophozoites, pre-encystment trophozoites, mature cysts and empty cysts could be observed by smear. So it is an important method for the clinical diagnosis. The edema and dissolved corneal epithelial cells, exudate cells, arthrospores or chlamydoconidium of mycelial fungus, vacuoles, lipid droplet and medicine crystallization should be differentiated with the pathogen. The movement of trophozoites could mainly be observed through wet-mount preparation. The detection of typical features of trophozoites, pre-encystment trophozoites, mature cysts and empty cysts by corneal smear is important for the etiological diagnosis of acanthamoeba keratitis.

  8. A retrospective study of nine cases of Acanthamoeba keratitis

    Directory of Open Access Journals (Sweden)

    Tetsuya Mutoh

    2010-10-01

    Full Text Available Tetsuya Mutoh, Isao Ishikawa, Yukihiro Matsumoto, Makoto ChikudaDokkyo Medical University Koshigaya Hospital, Saitama, JapanPurpose: To evaluate the clinical features of Acanthamoeba keratitis in nine patients diagnosed at Dokkyo Medical University Koshigaya Hospital, Saitama, Japan.Methods: In nine eyes of nine patients, Acanthamoeba keratitis was diagnosed by direct light microscopy of corneal scrapings stained by the Parker ink-potassium hydroxide method between September 2006 and September 2009. Their clinical features and course were studied retrospectively. Antifungal eye drops, systemic antifungal therapy, and surgical debridement of the corneal lesions were performed in all patients.Results: At presentation, the clinical stage was initial in six cases, transient in one case, and complete in two cases. The patients were all contact lens wearers who had washed their lens storage cases with tap water. After treatment, final visual acuity was improved in six cases, unchanged in one case, and worse in two cases. The patient with the worst final vision (hand motion had rheumatoid arthritis and was taking oral prednisolone, which led to corneal perforation and prevented adequate debridement from being done.Conclusion: Acanthamoeba keratitis is closely related to wearing contact lenses and washing the lens storage case with tap water. Although final visual acuity improved after treatment in most patients, insufficient surgical debridement resulted in a poor visual prognosis.Keywords: surgical debridement, Acanthamoeba keratitis, contact lens wearers

  9. three cases of acanthamoeba keratitis (Ak in Yazd

    Directory of Open Access Journals (Sweden)

    MR Shoja

    2006-04-01

    Full Text Available Acanthamoeba keratitis is a vision- threatening infection and the most important risk factors are contact lenses Characteristic symptoms include disproportionately severe ocular pain, epithelial ulcer, ring stromal infiltrate and resistance to antimicrobial treatment. The aim is to report the first cases of Acanthamoeba keratitis in Yazd in a retrospective study confirmed on histopathological and confocal microscopy. All of our patients used soft contact lenses and were women. The age range was between 20-29 years. One eye was`misdiagnosed as herpes simplex keratitis and two were misdiagnosed as bacterial keratitis. A delayed visit as well as a late diagnosis led to the advanced stage of eye disease. Improvement in visual acuity following medical therapy was seen in two patients and one patient needed urgent keratoplasty for corneal necrosis A prompt clinical and laboratory diagnosis along with treatment with propamidine- isentionate resulted in significant improvement of eye condition Failure to disinfect contact lenses and introduction of tap water rinsing of storage cases were associated with increased risk of Acanthamoeba infection. Penetrating keratoplasty is an effective treatment for medically unresponsive acanthamoeba keratitis. Confocal microscopy is the most effective and a fast diagnostic tool because it ensures the detection of acanthamebic cysts and trophozoids in corneal stroma .

  10. Caspase-like proteins: Acanthamoeba castellanii metacaspase and ...

    Indian Academy of Sciences (India)

    Caspases are cysteine proteases that are important regulators of programmed cell death in animals. Two novel relatives to members of the caspase families metacaspases and paracaspase have been discovered. Metacaspase type-1 was identified in Acanthamoeba castellanii, an opportunistic protozoan parasite that ...

  11. Mannose Induces the Release of Cytopathic Factors from Acanthamoeba castellanii

    Science.gov (United States)

    Leher, Henry; Silvany, Robert; Alizadeh, Hassan; Huang, Jing; Niederkorn, Jerry Y.

    1998-01-01

    Acanthamoeba keratitis is a chronic inflammatory disease of the cornea which is highly resistant to many antimicrobial agents. The pathogenic mechanisms of this disease are poorly understood. However, it is believed that the initial phases in the pathogenesis of Acanthamoeba keratitis involve parasite binding and lysis of the corneal epithelium. These processes were examined in vitro, using Acanthamoeba castellanii trophozoites. Parasites readily adhered to Chinese hamster corneal epithelial cells in vitro; however, parasite binding was strongly inhibited by mannose but not by lactose. Although mannose prevented trophozoite binding, it did not affect cytolysis of corneal epithelial cells. Moreover, mannose treatment induced trophozoites to release cytolytic factors that lysed corneal epithelial cells in vitro. These factors were uniquely induced by mannose because supernatants collected from either untreated trophozoites or trophozoites treated with other sugars failed to lyse corneal cells. The soluble factors were size fractionated in centrifugal concentrators and found to be ≥100 kDa. Treatment of the supernatants with the serine protease inhibitor phenylmethylsulfonyl fluoride inhibited most, but not all, of the cytopathic activity. These data suggest that the binding of Acanthamoeba to mannosylated proteins on the corneal epithelium may exacerbate the pathogenic cascade by initiating the release of cytolytic factors. PMID:9423832

  12. Riboflavin and ultraviolet A as adjuvant treatment against Acanthamoeba cysts.

    Science.gov (United States)

    Lamy, Ricardo; Chan, Elliot; Good, Samuel D; Cevallos, Vicky; Porco, Travis C; Stewart, Jay M

    2016-04-01

    Experimental studies have shown that the standard dose of riboflavin (R) or R + ultraviolet-A (UVA) as solo treatment are not able to exterminate Acanthamoeba cysts or even trophozoites. The purpose of this study is to determine whether the application of R + UVA can enhance the cysticidal effects of cationic antiseptic agents in vitro. The log of either polyhexamethylene biguanide or chlorhexidine minimal cysticidal concentration in solutions containing riboflavin (concentrations 0.1, 0.05 and 0.025%) plus either Acanthamoeba castellanii cysts or Acanthamoeba polyphaga cysts was determined and compared in groups treated with UVA 30 mW/cm(2) for 30 min and in control groups (with no exposure to UVA). A permutation test was used to determine the P value associated with treatment. Regardless of the riboflavin concentration and UVA treatment condition, no trophozoites were seen in plates where the cysts were previously exposed to cationic antiseptic agent concentrations ≥200 µg/mL for Acanthamoeba castellanii samples and ≥100 µg/mL for A. polyphaga samples. There was no statistical evidence that R + UVA treatment was associated with minimal cysticidal concentration (P = 0.82). R + UVA in doses up to 10 times higher than recommended for corneal crosslinking does not enhance the cysticidal effect of either polyhexamethylene biguanide or chlorhexidine in vitro. © 2015 Royal Australian and New Zealand College of Ophthalmologists.

  13. Acanthamoeba Keratitis at the King Khaled Eye Specialist Hospital

    International Nuclear Information System (INIS)

    Al-Mezaine, H.; Al-Muteb, M.; Al-Motowa, S.; Wagoner, M. D.

    2005-01-01

    To quantify the number of cases and clinical courses of Acanthamoeba keratitis treated at the King Khaled Eye Specialist Hospital (KKESH) between December 1982 and May 2005, and to review their clinical course and response to medical and surgical therapy. Retrospective review of medical records of all patients with Acanthamoeba keratitis diagnosed by the KKESH Microbiology or Pathology or Pathology Laboratory since the opening of the hospital. During a period of over 22 years, only six cases of confirmed. Acanthamoeba keratitis were diagnosedand treated at KKESH. In two cases the diagnosis was made by corneal biopsy, while four cases required examination of a histopathology specimen obtained at the time of therapeutic keratoplasty to establish the diagnosis. One eye was cured by medical therapy, while five eyes required one (4eyes) or two (1 eye) therapeutic penetrating keratoplasty (PKP) to achieve a clinical cure. Three eyes achieved good visual acuity (20/40, 20/50, 20/60), one eye achieved fair visual acuity (20/160), and two eyes suffered profound visual loss (hand motions). The incidence of Acanthamoeba keratitis may be less in Saudi Arabia than reported in Western countries although the clinical is similarly complicated, with most cases requiring therapeutic keratoplasty for definitive education of the organism. (author)

  14. Acanthamoeba keratitis - A six year epidemiological review from a tertiary care eye hospital in South India

    Directory of Open Access Journals (Sweden)

    Manikandan P

    2004-01-01

    Full Text Available PURPOSE: This study analyses the prevalence, demography, predisposing factors and seasonal variation of Acanthamoeba keratitis. METHODS: A retrospective review of all cases presenting with keratitis at the cornea clinic, Aravind Eye Hospital, Coimbatore, from August 1997 to July 2003, was done for screening patients with a provisional diagnosis of Acanthamoeba keratitis. Their records were further analyzed for microbiological details. Cases with culture proven Acanthamoeba keratitis were included for epidemiological analysis. RESULTS: From a total of 4519 patients who attended cornea clinic 32 (33 eyes patients were confirmed to be positive for Acanthamoeba keratitis. Twenty cases (62.5% were males. Majority (18; 54.2% of the Acanthamoeba keratitis eyes reported corneal trauma by solid objects. No peak period was observed in a year, as the number of cases was almost uniform in all months. CONCLUSION: This study indicates the increasing prevalence of Acanthamoeba keratitis among non-contact lens users in this region during the 6-year period.

  15. Estudio Transversal sobre la Relación entre Neuroticismo y Curso Clínico en Pacientes con Enfermedades Inflamatorias Intestinales

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    Juan Carlos Fernández Méndez

    2010-01-01

    Full Text Available En el presente trabajo se analiza la relación que existe entre neuroticismo y diversas condiciones médicas que hacen referencia al curso clínico de las enfermedades inflamatorias intestinales. Para desarrollar la investigación se tomaron medidas en neuroticismo mediante el Inventario de Personalidad de Eysenck a 106 participantes diagnosticados de colitis ulcerosa y enfermedad de Crohn. Los resultados reflejaron que la muestra global de pacientes con enfermedades inflamatorias intestinales mostraba valores en neuroticismo que se hallaban dentro de la normalidad; sin embargo, se pudo verificar que los valores diferían dependiendo del curso clínico de la patología. El estudio sugiere que las variaciones en neuroticismo son considerables cuando se analizan los datos de la muestra general y cuando se tienen en cuenta diversas condiciones del curso clínico.

  16. Non-contact lens related Acanthamoeba keratitis

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    Prashant Garg

    2017-01-01

    Full Text Available The purpose of the study is to describe epidemiology, clinical features, diagnosis, and treatment of Acanthamoeba keratitis (AK with special focus on the disease in nonusers of contact lenses (CLs. This study was a perspective based on authors' experience and review of published literature. AK accounts for 2% of microbiology-proven cases of keratitis. Trauma and exposure to contaminated water are the main predisposing factors for the disease. Association with CLs is seen only in small fraction of cases. Contrary to classical description experience in India suggests that out of proportion pain, ring infiltrate, and radial keratoneuritis are seen in less than a third of cases. Majority of cases present with diffuse infiltrate, mimicking herpes simplex or fungal keratitis. The diagnosis can be confirmed by microscopic examination of corneal scraping material and culture on nonnutrient agar with an overlay of Escherichia coli. Confocal microscopy can help diagnosis in patients with deep infiltrate; however, experience with technique and interpretation of images influences its true value. Primary treatment of the infection is biguanides with or without diamidines. Most patients respond to medical treatment. Corticosteroids play an important role in the management and can be used when indicated after due consideration to established protocols. Surgery is rarely needed in patients where definitive management is initiated within 3 weeks of onset of symptoms. Lamellar keratoplasty has been shown to have good outcome in cases needing surgery. Since the clinical features of AK in nonusers of CL are different, it will be important for ophthalmologists to be aware of the scenario wherein to suspect this infection. Medical treatment is successful if the disease is diagnosed early and management is initiated soon.

  17. Non-contact lens related Acanthamoeba keratitis

    Science.gov (United States)

    Garg, Prashant; Kalra, Paavan; Joseph, Joveeta

    2017-01-01

    The purpose of the study is to describe epidemiology, clinical features, diagnosis, and treatment of Acanthamoeba keratitis (AK) with special focus on the disease in nonusers of contact lenses (CLs). This study was a perspective based on authors’ experience and review of published literature. AK accounts for 2% of microbiology-proven cases of keratitis. Trauma and exposure to contaminated water are the main predisposing factors for the disease. Association with CLs is seen only in small fraction of cases. Contrary to classical description experience in India suggests that out of proportion pain, ring infiltrate, and radial keratoneuritis are seen in less than a third of cases. Majority of cases present with diffuse infiltrate, mimicking herpes simplex or fungal keratitis. The diagnosis can be confirmed by microscopic examination of corneal scraping material and culture on nonnutrient agar with an overlay of Escherichia coli. Confocal microscopy can help diagnosis in patients with deep infiltrate; however, experience with technique and interpretation of images influences its true value. Primary treatment of the infection is biguanides with or without diamidines. Most patients respond to medical treatment. Corticosteroids play an important role in the management and can be used when indicated after due consideration to established protocols. Surgery is rarely needed in patients where definitive management is initiated within 3 weeks of onset of symptoms. Lamellar keratoplasty has been shown to have good outcome in cases needing surgery. Since the clinical features of AK in nonusers of CL are different, it will be important for ophthalmologists to be aware of the scenario wherein to suspect this infection. Medical treatment is successful if the disease is diagnosed early and management is initiated soon. PMID:29133630

  18. Identification of unusual phospholipid fatty acyl compositions of Acanthamoeba castellanii.

    Science.gov (United States)

    Palusinska-Szysz, Marta; Kania, Magdalena; Turska-Szewczuk, Anna; Danikiewicz, Witold; Russa, Ryszard; Fuchs, Beate

    2014-01-01

    Acanthamoeba are opportunistic protozoan pathogens that may lead to sight-threatening keratitis and fatal granulomatous encephalitis. The successful prognosis requires early diagnosis and differentiation of pathogenic Acanthamoeba followed by aggressive treatment regimen. The plasma membrane of Acanthamoeba consists of 25% phospholipids (PL). The presence of C20 and, recently reported, 28- and 30-carbon fatty acyl residues is characteristic of amoeba PL. A detailed knowledge about this unusual PL composition could help to differentiate Acanthamoeba from other parasites, e.g. bacteria and develop more efficient treatment strategies. Therefore, the detailed PL composition of Acanthamoeba castellanii was investigated by 31P nuclear magnetic resonance spectroscopy, thin-layer chromatography, gas chromatography, high performance liquid chromatography and liquid chromatography-mass spectrometry. Normal and reversed phase liquid chromatography coupled with mass spectrometric detection was used for detailed characterization of the fatty acyl composition of each detected PL. The most abundant fatty acyl residues in each PL class were octadecanoyl (18∶0), octadecenoyl (18∶1 Δ9) and hexadecanoyl (16∶0). However, some selected PLs contained also very long fatty acyl chains: the presence of 28- and 30-carbon fatty acyl residues was confirmed in phosphatidylethanolamine (PE), phosphatidylserine, phosphatidic acid and cardiolipin. The majority of these fatty acyl residues were also identified in PE that resulted in the following composition: 28∶1/20∶2, 30∶2/18∶1, 28∶0/20∶2, 30∶2/20∶4 and 30∶3/20∶3. The PL of amoebae are significantly different in comparison to other cells: we describe here for the first time unusual, very long chain fatty acids with Δ5-unsaturation (30∶35,21,24) and 30∶221,24 localized exclusively in specific phospholipid classes of A. castellanii protozoa that could serve as specific biomarkers for the presence of these

  19. Identification of unusual phospholipid fatty acyl compositions of Acanthamoeba castellanii.

    Directory of Open Access Journals (Sweden)

    Marta Palusinska-Szysz

    Full Text Available Acanthamoeba are opportunistic protozoan pathogens that may lead to sight-threatening keratitis and fatal granulomatous encephalitis. The successful prognosis requires early diagnosis and differentiation of pathogenic Acanthamoeba followed by aggressive treatment regimen. The plasma membrane of Acanthamoeba consists of 25% phospholipids (PL. The presence of C20 and, recently reported, 28- and 30-carbon fatty acyl residues is characteristic of amoeba PL. A detailed knowledge about this unusual PL composition could help to differentiate Acanthamoeba from other parasites, e.g. bacteria and develop more efficient treatment strategies. Therefore, the detailed PL composition of Acanthamoeba castellanii was investigated by 31P nuclear magnetic resonance spectroscopy, thin-layer chromatography, gas chromatography, high performance liquid chromatography and liquid chromatography-mass spectrometry. Normal and reversed phase liquid chromatography coupled with mass spectrometric detection was used for detailed characterization of the fatty acyl composition of each detected PL. The most abundant fatty acyl residues in each PL class were octadecanoyl (18∶0, octadecenoyl (18∶1 Δ9 and hexadecanoyl (16∶0. However, some selected PLs contained also very long fatty acyl chains: the presence of 28- and 30-carbon fatty acyl residues was confirmed in phosphatidylethanolamine (PE, phosphatidylserine, phosphatidic acid and cardiolipin. The majority of these fatty acyl residues were also identified in PE that resulted in the following composition: 28∶1/20∶2, 30∶2/18∶1, 28∶0/20∶2, 30∶2/20∶4 and 30∶3/20∶3. The PL of amoebae are significantly different in comparison to other cells: we describe here for the first time unusual, very long chain fatty acids with Δ5-unsaturation (30∶35,21,24 and 30∶221,24 localized exclusively in specific phospholipid classes of A. castellanii protozoa that could serve as specific biomarkers for the presence of

  20. Interaction of Escherichia coli K1 and K5 with Acanthamoeba castellanii Trophozoites and Cysts

    OpenAIRE

    Matin, Abdul; Jung, Suk-Yul

    2011-01-01

    The existence of symbiotic relationships between Acanthamoeba and a variety of bacteria is well-documented. However, the ability of Acanthamoeba interacting with host bacterial pathogens has gained particular attention. Here, to understand the interactions of Escherichia coli K1 and E. coli K5 strains with Acanthamoeba castellanii trophozoites and cysts, association assay, invasion assay, survival assay, and the measurement of bacterial numbers from cysts were performed, and nonpathogenic E. ...

  1. Diversity and Seasonal Impact of Acanthamoeba Species in a Subtropical Rivershed

    OpenAIRE

    Kao, Po-Min; Chou, Ming-Yuan; Tao, Chi-Wei; Huang, Wen-Chien; Hsu, Bing-Mu; Shen, Shu-Min; Fan, Cheng-Wei; Chiu, Yi-Chou

    2013-01-01

    This study evaluated the presence of Acanthamoeba species in the Puzih River watershed, which features typical subtropical monsoon climate and is located just above the Tropic of Cancer in Taiwan. The relationship between the seasonal and geographical distributions of Acanthamoeba species in this rivershed was also investigated. Acanthamoeba species were detected in water samples using the amoebal enrichment culture method and confirmed by PCR. A total of 136 water samples were included in th...

  2. p21-activated kinase has substrate specificity similar to Acanthamoeba myosin I heavy chain kinase and activates Acanthamoeba myosin I.

    Science.gov (United States)

    Brzeska, H; Knaus, U G; Wang, Z Y; Bokoch, G M; Korn, E D

    1997-02-18

    Acanthamoeba class I myosins are unconventional, single-headed myosins that express actin-activated Mg2+-ATPase and in vitro motility activities only when a single serine or threonine in the heavy chain is phosphorylated by myosin I heavy chain kinase (MIHCK). Some other, but not most, class I myosins have the same consensus phosphorylation site sequence, and the two known class VI myosins have a phosphorylatable residue in the homologous position, where most myosins have an aspartate or glutamate residue. Recently, we found that the catalytic domain of Acanthamoeba MIHCK has extensive sequence similarity to the p21-activated kinase (PAK)/STE20 family of kinases from mammals and yeast, which are activated by small GTP-binding proteins. The physiological substrates of the PAK/STE20 kinases are not well characterized. In this paper we show that PAK1 has similar substrate specificity as MIHCK when assayed against synthetic substrates and that PAK1 phosphorylates the heavy chain (1 mol of P(i) per mol) and activates Acanthamoeba myosin I as MIHCK does. These results, together with the known involvement of Acanthamoeba myosin I, yeast myosin I, STE20, PAK, and small GTP-binding proteins in membrane- and cytoskeleton-associated morphogenetic transformations and activities, suggest that myosins may be physiological substrates for the PAK/STE20 family and thus mediators of these events.

  3. Subgenus systematics of Acanthamoeba: four nuclear 18S rDNA sequence types.

    Science.gov (United States)

    Gast, R J; Ledee, D R; Fuerst, P A; Byers, T J

    1996-01-01

    Classification of Acanthamoeba at the subgenus level has been problematic, but increasing reports of Acanthamoeba as an opportunistic human pathogen have generated an interest in finding a more consistent basis for classification. Thus, we are developing a classification scheme based on RNA gene sequences. This first report is based on analysis of complete sequences of nuclear small ribosomal subunit RNA genes (Rns) from 18 strains. Sequence variation was localized in 12 highly variable regions. Four distinct sequence types were identified based on parsimony and distance analyses. Three were obtained from single strains: Type T1 from Acanthamoeba castellanii V006, T2 from Acanthamoeba palestinensis Reich, and T3 from Acanthamoeba griffini S-7. T4, the fourth sequence type, included 15 isolates classified as A. castellanii, Acanthamoeba polyphaga, Acanthamoeba rhysodes or Acanthamoeba sp., and included all 10 Acanthamoeba keratitis isolates. Interstrain sequence differences within T4 were 0%-4.3%, whereas differences among sequence types were 6%-12%. Branching orders obtained by parsimony and distance analyses were inconsistent with the current classification of T4 strains and provided further evidence of a need to reevaluate criteria for classification in this genus. Based on this report and others in preparation, we propose that Rns sequence types provide the consistent quantititive basis for classification that is needed.

  4. Cutaneous Acanthamoeba infection in the acquired immunodeficiency syndrome: response to multidrug therapy.

    Science.gov (United States)

    Hunt, S J; Reed, S L; Mathews, W C; Torian, B

    1995-11-01

    Acanthamoeba, a free-living ameba of soil and water, produces the rare infections of granulomatous amebic encephalitis and amebic keratitis. We report a 38-year-old white man with the acquired immunodeficiency syndrome (AIDS) who experienced Acanthamoeba infection that presented as multiple skin nodules without associated encephalitis. Histologic examination revealed necrotizing granulomatous inflammation with numerous amebic organisms that were cultured and identified as Acanthamoeba group 2, probably Acanthamoeba castellani by monoclonal antibodies. Results of in vitro susceptibility testing demonstrated resistance to all six tested drugs. A partial clinical response, however, was obtained with multidrug therapy.

  5. Non-radioactive DNA probe and polymerase chain reaction procedures for the specific detection of Acanthamoeba.

    Science.gov (United States)

    Lai, S; Asgari, M; Henney, H R

    1994-02-01

    Acanthamoebae are potential pathogens which can cause serious infections of humans. A non-radioactive rDNA probe and polymerase chain reaction (PCR) amplification procedures which are specific, rapid, sensitive and safe for the detection of Acanthamoeba have been developed. A restriction fragment (126 bp; ArDNA-a) from a variable region of the cloned 26S rDNA unit of Acanthamoeba castellanii (from plasmid pAR2) was labelled by biotinylation. Cells and DNAs were incubated with the labelled rDNA probe to define conditions providing the highest hybridization specificity for Acanthamoeba by both colorimetric and chemiluminescent assays. Four recent isolates of Acanthamoeba, Acanthamoeba polyphaga, various bacteria, Herpes simplex virus, other eukaryotic amoebae and human cell lines, were sources of DNA for testing. The rDNA probe was found to be highly specific for Acanthamoeba and is capable of directly detecting about 250 cells without prior DNA purification. PCR primers for this unique ArDNA-a fragment have also been designed. Amplification of the targeted sequence by PCR using those primers yielded a single product which was specifically generated for Acanthamoeba template DNA and not DNA from the other control cells. This PCR procedure provided increased sensitivity with the direct detection of as few as 10 Acanthamoeba cells.

  6. Diagnostic Evaluation of Co-Occurrence of Acanthamoeba and Fungi in Keratitis: A Preliminary Report.

    Science.gov (United States)

    Raghavan, Anita; Baidwal, Shaffie; Vijayaraghavan, Prabhu; Rajeswari, Sakthi; Rajaraman, Revathi; Venkatapathy, Narendran; Menon, Sunitha; Rammohan, Ram

    2018-02-01

    To test the hypothesis that the coexistence of Acanthamoeba with other forms of microbial keratitis, especially fungal keratitis (FK), is more prevalent than suspected. A prospective diagnostic study whereby patients presenting with stromal keratitis were additionally tested for Acanthamoeba, irrespective of the initial diagnosis. In addition to the routine workup with Gram stain, KOH mount, and cultures on blood agar and potato dextrose agar, nonnutrient agar was included. Confocal microscopy was performed where feasible. Samples for polymerase chain reaction studies were also obtained. We present the preliminary report of the first 100 culture-positive cases. The primary outcome measured was the number of coexistent Acanthamoeba and FK. The secondary outcomes were the total number of Acanthamoeba cases detected and the correlation between clinical diagnosis and microbiological observations. Of the first 100 cases, 22 were culture positive for Acanthamoeba, of which 9 were associated with concurrent FK, 5 with bacterial keratitis, and 8 in isolation. However, only 2 cases were diagnosed clinically as Acanthamoeba, whereas 5 were Acanthamoeba suspects. An additional 4 cases of fungal/Acanthamoeba coexistence in keratitis were revealed purely by confocal microscopy. Acanthamoeba can coexist with other forms of microbial keratitis. The frequency of infection coexistent or otherwise is higher than reported, and the possibility of coinfection must be considered especially in unresponsive cases. Including nonnutrient agar and confocal microscopy in all cases of keratitis would perhaps translate into better treatment strategies and outcomes.

  7. Seasonal distribution of potentially pathogenic Acanthamoeba species from drinking water reservoirs in Taiwan.

    Science.gov (United States)

    Kao, Po-Min; Hsu, Bing-Mu; Hsu, Tsui-Kang; Liu, Jorn-Hon; Chang, Hsiang-Yu; Ji, Wen-Tsai; Tzeng, Kai-Jiun; Huang, Shih-Wei; Huang, Yu-Li

    2015-03-01

    In order to detect the presence/absence of Acanthamoeba along with geographical variations, water quality variations and seasonal change of Acanthamoeba in Taiwan was investigated by 18S ribosomal RNA (rRNA) gene TaqMan quantitative real-time PCR. Samples were collected quarterly at 19 drinking water reservoir sites from November 2012 to August 2013. Acanthamoeba was detected in 39.5 % (30/76) of the water sample, and the detection rate was 63.2 % (12/19) from samples collected in autumn. The average concentration of Acanthamoeba was 3.59 × 10(4) copies/L. For geographic distribution, the detection rate for Acanthamoeba at the northern region was higher than the central and southern regions in all seasons. Results of Spearman rank test revealed that heterotrophic plate count (HPC) had a negative correlation (R = -0.502), while dissolved oxygen (DO) had a positive correlation (R = 0.463) in summer. Significant differences were found only between the presence/absence of Acanthamoeba and HPC in summer (Mann-Whitney U test, P Acanthamoeba were identified, and T4 was the most commonly identified Acanthamoeba genotypes. The presence of Acanthamoeba in reservoirs presented a potential public health threat and should be further examined.

  8. Acanthamoeba protease activity promotes allergic airway inflammation via protease-activated receptor 2.

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    Mi Kyung Park

    Full Text Available Acanthamoeba is a free-living amoeba commonly present in the environment and often found in human airway cavities. Acanthamoeba possesses strong proteases that can elicit allergic airway inflammation. To our knowledge, the aeroallergenicity of Acanthamoeba has not been reported. We repeatedly inoculated mice with Acanthamoeba trophozoites or excretory-secretory (ES proteins intra-nasally and evaluated symptoms and airway immune responses. Acanthamoeba trophozoites or ES proteins elicited immune responses in mice that resembled allergic airway inflammation. ES proteins had strong protease activity and activated the expression of several chemokine genes (CCL11, CCL17, CCL22, TSLP, and IL-25 in mouse lung epithelial cells. The serine protease inhibitor phenyl-methane-sulfonyl fluoride (PMSF inhibited ES protein activity. ES proteins also stimulated dendritic cells and enhanced the differentiation of naive T cells into IL-4-secreting T cells. After repeated inoculation of the protease-activated receptor 2 knockout mouse with ES proteins, airway inflammation and Th2 immune responses were markedly reduced, but not to basal levels. Furthermore, asthma patients had higher Acanthamoeba-specific IgE titers than healthy controls and we found Acanthamoeba specific antigen from house dust in typical living room. Our findings suggest that Acanthamoeba elicits allergic airway symptoms in mice via a protease allergen. In addition, it is possible that Acanthamoeba may be one of the triggers human airway allergic disease.

  9. Acanthamoeba Protease Activity Promotes Allergic Airway Inflammation via Protease-Activated Receptor 2

    Science.gov (United States)

    Park, Mi Kyung; Cho, Min Kyoung; Kang, Shin Ae; Park, Hye-Kyung; Kim, Dong-Hee; Yu, Hak Sun

    2014-01-01

    Acanthamoeba is a free-living amoeba commonly present in the environment and often found in human airway cavities. Acanthamoeba possesses strong proteases that can elicit allergic airway inflammation. To our knowledge, the aeroallergenicity of Acanthamoeba has not been reported. We repeatedly inoculated mice with Acanthamoeba trophozoites or excretory-secretory (ES) proteins intra-nasally and evaluated symptoms and airway immune responses. Acanthamoeba trophozoites or ES proteins elicited immune responses in mice that resembled allergic airway inflammation. ES proteins had strong protease activity and activated the expression of several chemokine genes (CCL11, CCL17, CCL22, TSLP, and IL-25) in mouse lung epithelial cells. The serine protease inhibitor phenyl-methane-sulfonyl fluoride (PMSF) inhibited ES protein activity. ES proteins also stimulated dendritic cells and enhanced the differentiation of naive T cells into IL-4-secreting T cells. After repeated inoculation of the protease-activated receptor 2 knockout mouse with ES proteins, airway inflammation and Th2 immune responses were markedly reduced, but not to basal levels. Furthermore, asthma patients had higher Acanthamoeba-specific IgE titers than healthy controls and we found Acanthamoeba specific antigen from house dust in typical living room. Our findings suggest that Acanthamoeba elicits allergic airway symptoms in mice via a protease allergen. In addition, it is possible that Acanthamoeba may be one of the triggers human airway allergic disease. PMID:24658532

  10. Acanthamoeba sohi, n. sp., a pathogenic Korean isolate YM-4 from a freshwater fish

    OpenAIRE

    Im, Kyung-il; Shin, Ho-Joon

    2003-01-01

    A new species of Acanthamoeba was isolated from a freshwater fish in Korea and tentatively named Acanthamoeba sp. YM-4 (Korean isolate YM-4). The trophozoites were 11.0-23.0 µm in length and had hyaline filamentous projections. Cysts were similar to those of A. culbertsoni and A. royreba, which were previously designated as Acanthamoeba group III. Acanthamoeba YM-4 can survive at 40℃, and its generation time was 19.6 hr, which was longer than that of A. culbertsoni. In terms of the in vitro c...

  11. Morpho-Physiological and Biochemical Criteria of Acanthamoeba spp. Isolated from the Egyptian Aquatic Environment

    Science.gov (United States)

    Al-Herrawy, A; Bahgat, M; Mohammed, A; Ashour, A; Hikal, W

    2013-01-01

    Background The free-living amoebae Acanthamoeba spp., have been recognized as etiologic agents of amoebic encephalitis, keratitis, otitis, lung lesions and other skin infections mainly in immuno-compromised individuals. In this study, morpho-physiological and biochemical characterization of Acanthamoeba strains isolated from the Egyptian aquatic environment were surveyed. Methods Some Acanthamoeba species were cultivated on non-nutrient agar. Isolated strains of Acanthamoeba were identification based on the morphology of trophic and cyst forms in addition to temperature and osmo-tolerance assays. Biochemical characterization of the isolated amoeba strains was performed using quantitative assay as well as qualitative determination of proteolytic activity in zymograph analysis. Results Potentially pathogenic Acanthamoeba species were isolated from all of the examined water sources. Colorimetric assays showed protease activity in the heat-tolerant isolates of Acanthamoeba. All pathogenic isolates of Acanthamoeba exhibited higher protease activity than did the non-pathogenic ones. The zymographic protease assays showed various banding patterns for different strains of Acanthamoeba. Conclusion The incidence and prevalence of the pathogenic Acanthamoeba species in the aquatic environment using parasitological and biochemical diagnostic tools will provide baseline data against which the risk factors associated with waterborne transmission can be identified. PMID:23914245

  12. The effect of concurrent Pseudomonas or Xanthomonas exposure on adherence of Acanthamoeba castellanii to soft contact lenses.

    Science.gov (United States)

    Kelly, L D; Xu, L

    1996-05-01

    Approximately 85% of Acanthamoeba-contaminated contact lens systems in asymptomatic patients have concurrent bacterial contamination. Pseudomonas aeruginosa and Xanthomonas maltophilia are common contact lens contaminants; we investigated the effect of coincubation of Acanthamoeba adherence to contact lenses. A. castellanii, 1 x 10(5) organisms/ml, was coincubated with P. aeruginosa or X. maltophilia, 1 x 10(8) CFU/ml in phosphate-buffered saline. Sterile, unworn polymacon, etafilcon A or lidofilcon contact lens were investigated. The experimental groups were: (I) lenses exposed to bacteria for 1 h, then Acanthamoeba for 2 h; (II) lenses exposed concurrently to bacteria and Acanthamoeba for 2 h; (III) Acanthamoeba coincubated with bacteria for 24 h, then lenses exposed for 2 h; (IV) lenses exposed to Acanthamoeba for 2 h (control). For all experimental groups, Acanthamoeba adherence was greater to lidofilcon than to polymacon and etafilcon. For both P. aeruginosa and X. maltophilia, neither group I nor group II displayed greater Acanthamoeba adherence than group IV. Group III exhibited significantly less adherence than group IV for lidofilcon and polymacon. The decrease in group III adherence reflected an overall decrease in Acanthamoeba trophozoite concentration. Short bacteria/Acanthamoeba coincubation times did not result in increased Acanthamoeba adherence. Twenty-four-hour coincubation resulted in decreased adherence for Pseudomonas and unchanged adherence rates for Xanthomonas. This model suggests that Pseudomonas or Xanthomonas co-contamination does not necessarily facilitate quantitative Acanthamoeba contact lens adherence.

  13. In vitro evaluations of topical agents to treat Acanthamoeba keratitis.

    Science.gov (United States)

    Sunada, Atsuko; Kimura, Keigo; Nishi, Isao; Toyokawa, Masahiro; Ueda, Akiko; Sakata, Tomomi; Suzuki, Takashi; Inoue, Yoshitsugu; Ohashi, Yuichi; Asari, Seishi; Iwatani, Yoshinori

    2014-10-01

    To evaluate the effectiveness of topical agents for the treatment of Acanthamoeba keratitis (AK). Laboratory research. Fifty-six Acanthamoeba isolates from 56 patients with clinically proven AK were studied. The effectiveness of 7 agents against Acanthamoeba cysts was determined in vitro. The agents were 1.0% povidone-iodine, 0.05% benzalkonium chloride (BZC), 0.02% chlorhexidine gluconate (CHG), 0.1% propamidine isethionate, 0.02% polyhexamethylene biguanide (PHMB), 5.0% natamycin, and 1.0% voriconazole (VRCZ). These concentrations are those recommended for patients. In addition, 10-fold dilutions of each of the agents were tested. After exposing the cysts to each agent at 35°C for 1 hour or 24 hours, the agents were removed by centrifugal washing. The exposed cysts were observed by optical microscopy for 7 days. In addition, the fine structures of the exposed isolates were examined by transmission electron microscopy (TEM). The genotype of the isolates was determined by 18S rDNA fragment sequencing. The in vitro susceptibility was determined by complete growth inhibition, and the morphologic appearance was determined by TEM. The genotypes of the 56 isolates were determined by 18S rDNA fragment sequencing. The Acanthamoeba cysts were most susceptible to natamycin, followed by povidone-iodine, BZC, PHMB, propamidine, and CHG. None of the strains was susceptible to VRCZ. The susceptibilities to PHMB and CHG may be time dependent and to propamidine may be concentration dependent. Transmission electron microscopy showed changes in the inner structure of the cysts exposed to natamycin and povidone-iodine. The Acanthamoeba genotype was T4 in 52 isolates, and cysts with the same genotype had different agent susceptibilities. Natamycin and povidone-iodine had excellent cysti-static (or cystcidal) effects, and PHMB and propamidine did not. There was no correlation between agent effectiveness and Acanthamoeba genotype. Therefore, susceptibility tests of isolates are needed

  14. Evaluation of allergic sensitivity to Acanthamoeba allergen in patients with chronic cough.

    Science.gov (United States)

    Park, Hye-Kyung; Park, Mi-Kyung; Kim, Ki Uk; Kang, Shin Ae; Park, Sang Kyun; Ahn, Soon Cheol; Kim, Dong-Hee; Yu, Hak Sun

    2016-01-01

    Acanthamoeba and their proteins can elicit severe allergic airway inflammation in experimental mice. Although Acanthamoeba can induce severe allergic airway inflammation in mice, there is no allergenicity data for humans. We performed a skin-prick test on 65 patients with chronic cough by using 54 previously known allergens and Acanthamoeba excretory-secretory proteins and enzyme-linked immunosorbent assay on 34 patients to evaluate Acanthamoeba-specific serum immunoglobulin (Ig) levels. To detect a novel Acanthamoeba allergen, Western blot analysis was performed on serum from patients who reacted positively to Acanthamoeba or some pollen allergens. After skin-prick testing, 29 patients (44.6%) showed positive reactions to one or more common aeroallergens. Acanthamoeba allergenicity was evaluated in 4 of 65 subjects (6.1%). An Acanthamoeba-positive reaction was closely related to several pollen allergens, especially willow tree, poplar, elm, oak, velvet grass, and cockroach. Average levels of Acanthamoeba-specific IgG subtypes in patient serum did not differ compared with healthy subjects; however, Acanthamoeba-specific IgE titers of patients were significantly higher than in healthy subjects. IgE antibodies of patients who tested positive in the skin-prick test reacted strongly to the 15 kDa excretory-secretory protein. Moreover, these antigens also reacted with those who tested positive in the skin-prick test to pollens. Taken together, our results indicated that some patients with allergy showed a positive response to the skin-prick test and that they also have high IgE serum levels. However, further experimental investigation is warranted because our preliminary findings indicated that Acanthamoeba might be a new allergen in humans.

  15. La peroxidación lipídica en la etiopatogenia de la enfermedad periodontal inflamatoria

    Directory of Open Access Journals (Sweden)

    Bárbara E García Triana

    Full Text Available Las especies reactivas del oxígeno están implicadas en la etiopatogenia de la inflamación. Durante la activación de los leucocitos, se liberan grandes cantidades de estas especies, cuya función es la eliminación de los agentes patógenos. Si las defensas antioxidantes de los tejidos no funcionan eficientemente, son inducidas reacciones radicálicas que afectan a las biomoléculas. El ataque a los lípidos de la membrana celular provoca su peroxidación, con la consiguiente formación de nuevas especies radicálicas y metabolitos tóxicos. La presencia de un fuerte infiltrado inflamatorio en los tejidos periodontales, durante la enfermedad periodontal inflamatoria, ha sugerido la posible participación de las especies reactivas del oxígeno en la etiopatogenia de esta enfermedad. Se supone que el ataque de estas sustancias a los tejidos periodontales con deficiente defensa antioxidante, provoca la aparición de la peroxidación lipídica, que puede conducir a la lisis celular y la activación de proteasas.

  16. Osteomielitis esternal y escrofuloderma por vacuna BCG.

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    Ivohne Fernanda Corrales

    2003-06-01

    Full Text Available La vacuna BCG se ha usado en todo el mundo desde principios del siglo XX para la prevención de la tuberculosis. Se describe el caso de una niña de 13 meses de edad, previamente sana, que consultó por una masa esternal. El estudio radiológico mostró erosión perióstica. La lesión fue resecada y en la histopatología se encontró una reacción inflamatoria crónica con granulomas caseificantes con compromiso óseo y cutáneo. Se realizó una amplificación por PCR con iniciadores específicos de Mycobacterium tuberculosis del ADN obtenido a partir del tejido incluido en parafina, cuyo resultado fue negativo. Los antecedentes de vacunación con BCG, la aparición de este tipo de granulomas y la ausencia de ADN de M. tuberculosis en el tejido resecado apoyan el diagnóstico de osteomielitis esternal y escrofuloderma por BCG. La osteomielitis es una complicación infrecuente de la vacunación por BCG, que puede presentarse especialmente en pacientes inmunosuprimidos. La evolución clínica de la paciente no ha demostrado ninguna forma de inmunodeficiencia.

  17. Acanthamoeba pearcei n. sp. (Protozoa: Amoebida) from sewage contaminated sediments.

    Science.gov (United States)

    Nerad, T A; Sawyer, T K; Lewis, E J; McLaughlin, S M

    1995-01-01

    Seabottom sediments from a discontinued Philadelphia-Camden 40-Mile ocean sewage disposal site were cultured for cyst-forming free-living amoebae. Barge delivered wastes were discharged at the site from 1973 until 1980 when the site was closed. One station at the southeast margin of the site was sampled at a depth of approximately 50 m, twice in 1978 and once in 1982, 1983 and 1984. Sediment from the 1978 collection yielded Acanthamoeba polyphaga, Vahlkampfia sp., and an unknown amoeba with stellate endocysts similar to those of A. astronyxis. Trophozoites and cysts of the isolate were typical of those described for the genus Acanthamoeba. Biochemical tests employing enzyme electrophoresis and morphological studies on live and stained specimens showed that the isolate was distinct from other well-described species within the family Acanthamoebidae Sawyer & Griffin, 1975.

  18. Effect of bacteria on survival and growth of Acanthamoeba castellanii.

    Science.gov (United States)

    Wang, X; Ahearn, D G

    1997-04-01

    The growth and survival of Acanthamoeba castellanii in the presence of Gram-negative bacteria such as Pseudomonas aeruginosa, Escherichia coli, Serratia marcescens, and Stenotrophomonas maltophilia varied with the densities and species of bacteria. All species of bacteria suspended in a buffered saline at densities of 10(5) to 10(6)/ml supported the growth and survival of 10(6)/ml trophozoites of Acanthamoeba castellanii in a buffered saline solution. At densities of bacteria to amoebae of 100:1 or greater, growth and survival of A. castellanii were suppressed, particularly by P. aeruginosa. In an enrichment medium, the rapid growth of most co-inoculated bacteria inhibited the growth and survival of the amoeba.

  19. Thermal unfolding of Acanthamoeba myosin II and skeletal muscle myosin.

    Science.gov (United States)

    Zolkiewski, M; Redowicz, M J; Korn, E D; Ginsburg, A

    1996-04-16

    Studies on the thermal unfolding of monomeric Acanthamoeba myosin II and other myosins, in particular skeletal muscle myosin, using differential scanning calorimetry (DSC) are reviewed. The unfolding transitions for intact myosin or its head fragment are irreversible, whereas those of the rod part and its fragments are completely reversible. Acanthamoeba myosin II unfolds with a high degree of cooperativity from ca. 40-45 degrees C at pH 7.5 in 0.6 M KCl, producing a single, sharp endotherm in DSC. In contrast, thermal transitions of rabbit skeletal muscle myosin occur over a broader temperature range (ca. 40-60 degrees C) under the same conditions. The DSC studies on the unfolding of the myosin rod and its fragments allow identification of cooperative domains, each of which unfolds according to a two-state mechanism. Also, DSC data show the effect of the nucleotide-induced conformational changes in the myosin head on the protein stability.

  20. Three-dimensional solution structure of Acanthamoeba profilin-I

    Science.gov (United States)

    1993-01-01

    We have determined a medium resolution three-dimensional solution structure of Acanthamoeba profilin-I by multidimensional nuclear magnetic resonance spectroscopy. This 13-kD actin binding protein consists of a five stranded antiparallel beta sheet flanked by NH2- and COOH-terminal helices on one face and by a third helix and a two stranded beta sheet on the other face. Data from actin-profilin cross- linking experiments and the localization of conserved residues between profilins in different phyla indicate that actin binding occurs on the molecular face occupied by the terminal helices. The other face of the molecule contains the residues that differ between Acanthamoeba profilins-I and II and may be important in determining the difference in polyphosphoinositide binding between these isoforms. This suggests that lipids and actin bind to different faces of the molecule. PMID:8397216

  1. Double-Biguanide Therapy for Resistant Acanthamoeba Keratitis

    Directory of Open Access Journals (Sweden)

    Giulio Ferrari

    2011-11-01

    Full Text Available Aims: To report the clinical and diagnostic findings of a patient with Acanthamoeba keratitis resistant to both polyhexamethylene biguanide (PHMB-hexamidine and chlorhexidine-hexamidine treatment. Methods: Slit-lamp biomicroscopy, corneal cell scraping and histopathology were performed on a 39-year-old woman presenting with corneal ulcer in her left eye. Results: The patient was successfully treated with PHMB-chlorhexidine association therapy. Subsequent perforating keratoplasty remained clear at the last follow-up visit after 7 months and increased visual acuity to 20/20 with correction. Conclusions: This case emphasizes the proteiform aspects of Acanthamoeba drug resistance, and suggests that PHMB-chlorhexidine association might represent an additional option for cases resistant to standard therapy.

  2. Detection of glycoproteins in the Acanthamoeba plasma membrane

    Energy Technology Data Exchange (ETDEWEB)

    Paatero, G.I.L. (Abo Akademi (Finland)); Gahmberg, C.G. (Univ. of Helsinki (Finland))

    1988-11-01

    In the present study the authors have shown that glycoproteins are present in the plasma membrane of Acanthamoeba castellanii by utilizing different radioactive labeling techniques. Plasma membrane proteins in the amoeba were iodinated by {sup 125}I-lactoperoxidase labeling and the solubilized radiolabeled glycoproteins were separated by lectin-Sepharose affinity chromatography followed by polyacrylamide gel electrophoresis. The periodate/NaB{sup 3}H{sub 4} and galactose oxidase/NaB{sup 3}H{sub 4} labeling techniques were used for labeling of surface carbohydrates in the amoeba. Several surface-labeled glycoproteins were observed in addition to a diffusely labeled region with M{sub r} of 55,000-75,000 seen on electrophoresis, which could represent glycolipids. The presence of glycoproteins in the plasma membrane of Acanthamoeba castellanii was confirmed by metabolic labeling with ({sup 35}S)methionine followed by lectin-Sepharose affinity chromatography and polyacrylamide gel electrophoresis.

  3. Detection of glycoproteins in the Acanthamoeba plasma membrane

    International Nuclear Information System (INIS)

    Paatero, G.I.L.; Gahmberg, C.G.

    1988-01-01

    In the present study the authors have shown that glycoproteins are present in the plasma membrane of Acanthamoeba castellanii by utilizing different radioactive labeling techniques. Plasma membrane proteins in the amoeba were iodinated by 125 I-lactoperoxidase labeling and the solubilized radiolabeled glycoproteins were separated by lectin-Sepharose affinity chromatography followed by polyacrylamide gel electrophoresis. The periodate/NaB 3 H 4 and galactose oxidase/NaB 3 H 4 labeling techniques were used for labeling of surface carbohydrates in the amoeba. Several surface-labeled glycoproteins were observed in addition to a diffusely labeled region with M r of 55,000-75,000 seen on electrophoresis, which could represent glycolipids. The presence of glycoproteins in the plasma membrane of Acanthamoeba castellanii was confirmed by metabolic labeling with [ 35 S]methionine followed by lectin-Sepharose affinity chromatography and polyacrylamide gel electrophoresis

  4. Uso del cefadroxilo oral en las neumopatías inflamatorias adquiridas en la comunidad

    Directory of Open Access Journals (Sweden)

    Juan José Pisonero Socías

    1999-12-01

    Full Text Available Se realizó un estudio del uso del cefadroxilo (cefalosporina oral de 1ra. generación en 100 pacientes con diagnóstico de sespsis respiratoria baja extrahospitalaria, donde se utilizó un esquema de dosis de 500 mg de cada 12 horas durante 7 a 10 días. A 60 pacientes se les administró 1 g por 7 días, de los cuales curaron 49 para el 81 %; de los 36 pacientes a los que se les administró 1 g por 10 días curaron 28, lo que representa el 77 % y de los 4 restantes que recibieron una dosis de 2 g por 10 días curaron 2 para el 50 %. Se efectuó además un análisis comparativo de los costos en tratamientos con penicilina cristalina, cefazolina, ceftriaxona y aminoglucósidos en la misma afección y se logró una disminución en el costo hospitalario y el consumo de antibióticosA study on the use of cefadroxil (1st generation oral cephalosporins was conducted among 100 patients with diagnosis of extrahospital lower respiratory sepsis. A dosage schedule of 500 mg every 12 hours during 7 or 10 days was used. 49 (81 % of the 60 patients that were administered 1 g during 7 days healed, whereas 28 (77 % of those who received 1 g for 10 days cured, too. 2(50 % of the other 4 that were given doses of 2 g for 10 days recovered from the disease. A comparative analysis of the costs generated by the use of crystalline penicillin, ceftriaxone, cefazolin and aminoglycosides to treat the same affection was made, and a reduction of hospital cost and antibiotic consumption was attained

  5. Treatment of acanthamoeba keratitis with intravenous pentamidine before therapeutic keratoplasty.

    Science.gov (United States)

    Sacher, Bradley A; Wagoner, Michael D; Goins, Kenneth M; Sutphin, John E; Greiner, Mark A; Kitzmann, Anna S

    2015-01-01

    The aim of this study was to evaluate the outcome of pretreatment of Acanthamoeba keratitis with intravenous pentamidine (IVP) before therapeutic keratoplasty (TKP). A retrospective chart review was performed of the medical records of every patient treated with IVP before TKP for Acanthamoeba keratitis at a single, tertiary care eye center between January 1, 2002, and December 31, 2012. The main outcome measures were microbiological cure, graft survival, and visual outcome. Eight eyes of 7 patients met the inclusion criteria. Preoperatively, all 8 eyes had failed traditional antiamoebic therapy, including 5 eyes with recurrent infections after previous TKP. The patients were treated with IVP (190-400 mg/d) for a median of 14 days (range, 7-26 days). After 8 TKP, a microbiological cure was achieved, and a clear graft was maintained in 5 (62.5%) eyes during a mean follow-up interval of 31.2 months (range, 1.0-95.7 months). Repeat TKP in 3 eyes with recurrent Acanthamoeba keratitis resulted in 2 additional microbiological cures and 1 more clear graft. The final best-corrected visual acuity was ≥20/40 in 5 (62.5%) eyes and worse than 20/200 in 3 eyes. Overall, the final vision was improved in 6 (75.0%) eyes, remained the same in 1 (12.5%) eye, and was worse in 1 (12.5%) eye. The adjunctive use of IVP before TKP may assist with the achievement of microbiological cure, clear graft, and good visual outcome in a majority of eyes with Acanthamoeba keratitis.

  6. Possible environmental sources of Acanthamoeba spp in contact lens wearers.

    OpenAIRE

    Seal, D; Stapleton, F; Dart, J

    1992-01-01

    The water supply and dust samples from the home environment (bathrooms and kitchens) of 50 wearers of contact lenses (CLs) were cultured for the presence of free-living amoebae. CL cases, solutions, and water taps were cultured for bacteria, which amoebae require for growth. Acanthamoeba spp were isolated from water drawn from six bathroom cold water taps (tank supplied), five in the presence of limescale, and from one kitchen cold water tap (mains supplied). There was an association between ...

  7. Development of an immunochromatographic assay kit using fluorescent silica nanoparticles for rapid diagnosis of Acanthamoeba keratitis.

    Science.gov (United States)

    Toriyama, Koji; Suzuki, Takashi; Inoue, Tomoyuki; Eguchi, Hiroshi; Hoshi, Saichi; Inoue, Yoshitsugu; Aizawa, Hideki; Miyoshi, Kazutomi; Ohkubo, Michio; Hiwatashi, Eiji; Tachibana, Hiroshi; Ohashi, Yuichi

    2015-01-01

    We developed an immunochromatographic assay kit that uses fluorescent silica nanoparticles bound to anti-Acanthamoeba antibodies (fluorescent immunochromatographic assay [FICGA]) and evaluated its efficacy for the detection of Acanthamoeba and diagnosis of Acanthamoeba keratitis (AK). The sensitivity of the FICGA kit was evaluated using samples of Acanthamoeba trophozoites and cysts diluted to various concentrations. A conventional immunochromatographic assay kit with latex labels (LICGA) was also evaluated to determine its sensitivity in detecting Acanthamoeba trophozoites. To check for cross-reactivity, the FICGA was performed by using samples of other common causative pathogens of infectious keratitis, such as Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, and Candida albicans. Corneal scrapings from patients with suspected AK were tested with the FICGA kit to detect the presence of Acanthamoeba, and the results were compared with those of real-time PCR. The FICGA kit detected organisms at concentrations as low as 5 trophozoites or 40 cysts per sample. There were no cross-reactivities with other pathogens. The FICGA was approximately 20 times more sensitive than the LICGA for the detection of Acanthamoeba trophozoites. The FICGA kit yielded positive results for all 10 patients, which corresponded well with the real-time PCR results. The FICGA kit demonstrated high sensitivity for the detection of Acanthamoeba and may be useful for the diagnosis of AK. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  8. Restriction endonuclease analysis of mitochondrial DNA of Acanthamoeba sp. YM-4 (Korean isolate).

    Science.gov (United States)

    Shin, H J; Im, K; Jeon, K W

    1997-06-01

    Acanthamoeba sp. YM-4 is similar to A. culbertsoni based upon morphological characteristics of trophozoites and cysts. However, based on other characteristics, pathogenicity to mice, in vitro cytotoxicity and isoenzyme patterns. Acanthamoeba sp. YM-4 was quite different from A. culbertsoni. Restriction fragment length polymorphism (RFLP) analysis of mtDNA is useful in the classification of members belonging to the genus Acanthamoeba. Therefore, in this study, RFLP analysis of Acanthamoeba mtDNAs was accomplished using five restriction enzymes: HaeIII, HindIII, ClaI, PvuII and SalI. Each restriction enzyme produced approximately 3-15 fragments (range: from 0.6 kbp to 34.4 kbp). The mtDNA genome size, calculated by the summation of restriction fragments, averaged 46.4 kbp in Acanthamoeba sp. YM-4, 48.3 kbp in A. culbertsoni and 48.8 kbp in A. polyphaga, respectively. Digested mtDNA fragments of Acanthamoeba sp. YM-4 contained nine and seven same size fragments, respectively, from a total of 67 and 69 fragments observed in A. culbertsoni and A. polyphaga. An estimate of the genetic divergence was 10.1% between Acanthamoeba sp. YM-4 and A. culbertsoni, and 9.9% between Acanthamoeba sp. YM-4 and A. polyphaga.

  9. Effects of temperature, amebic strain, and carbohydrates on Acanthamoeba adherence to corneal epithelium in vitro.

    Science.gov (United States)

    Morton, L D; McLaughlin, G L; Whiteley, H E

    1991-01-01

    An in vitro coincubation assay was used to measure adhesion of radiolabeled Acanthamoeba trophozoites to corneal epithelium. Adhesion of amebae to corneal epithelium was higher at 25 degrees C than at 37 or 4 degrees C, did not consistently correlate with the reported pathogenicity of the strain of Acanthamoeba, and was inhibited by mannose and by methyl-alpha-D-mannopyranoside. PMID:1894379

  10. Cellulose biosynthesis pathway is a potential target in the improved treatment of Acanthamoeba keratitis.

    Science.gov (United States)

    Dudley, Ricky; Alsam, Selwa; Khan, Naveed Ahmed

    2007-05-01

    Acanthamoeba is an opportunistic protozoan pathogen that can cause blinding keratitis as well as fatal granulomatous encephalitis. One of the distressing aspects in combating Acanthamoeba infections is the prolonged and problematic treatment. For example, current treatment against Acanthamoeba keratitis requires early diagnosis followed by hourly topical application of a mixture of drugs that can last up to a year. The aggressive and prolonged management is due to the ability of Acanthamoeba to rapidly adapt to harsh conditions and switch phenotypes into a resistant cyst form. One possibility of improving the treatment of Acanthamoeba infections is to inhibit the ability of these parasites to switch into the cyst form. The cyst wall is partially made of cellulose. Here, we tested whether a cellulose synthesis inhibitor, 2,6-dichlorobenzonitrile (DCB), can enhance the effects of the antiamoebic drug pentamidine isethionate (PMD). Our findings revealed that DCB can block Acanthamoeba encystment and may improve the antiamoebic effects of PMD. Using in vitro assays, the findings revealed that DCB enhanced the inhibitory effects of PMD on Acanthamoeba binding to and cytotoxicity of the host cells, suggesting the cellulose biosynthesis pathway as a novel target for the improved treatment of Acanthamoeba infections.

  11. Utility of real-time polymerase chain reaction in diagnosing and treating acanthamoeba keratitis.

    Science.gov (United States)

    Itahashi, Motoki; Higaki, Shiro; Fukuda, Masahiko; Mishima, Hiroshi; Shimomura, Yoshikazu

    2011-11-01

    Using real-time polymerase chain reaction (PCR), we detected Acanthamoeba and monitored the changes in Acanthamoeba DNA copy number over the treatment course in patients suspected of Acanthamoeba keratitis (AK). Subjects were 6 patients (average age, 26.2 years) suspected of AK at the Kinki University Outpatient Clinic. For detection of Acanthamoeba, patients' corneal scrapings were collected for smear analysis, culture, and real-time PCR. After the diagnosis of AK was confirmed, treatment was initiated based on the quantitative result of the real-time PCR. Both the smear and culture were positive for Acanthamoeba in 4 cases and negative in 2 cases (agreement in 3 cases and disagreement in 2 cases). By real-time PCR, all 6 cases were positive for Acanthamoeba with an average DNA copy number of 4.8 ± 9.1 × 10 copies per sample. We further monitored the variation in the Acanthamoeba DNA copy number over the treatment course and successfully treated all the patients. DNA copy number provided a parallel with other clinical features of AK. Real-time PCR can be a useful method for a rapid and precise diagnosis of AK. Moreover, utility of the Acanthamoeba DNA copy number obtained by real-time PCR can help ophthalmologists in making the best treatment decision.

  12. Trehalose During Two Stress Responsesin Acanthamoeba: DifferentiationBetween Encystation and Pseudocyst Formation

    Czech Academy of Sciences Publication Activity Database

    Bínová, E.; Bína, David; Ashford, D.; Thomas-Oates, J.; Nohýnková, E.

    2017-01-01

    Roč. 168, č. 6 (2017), s. 649-662 ISSN 1434-4610 Institutional support: RVO:60077344 Keywords : Trehalose Acanthamoeba * Acanthamoeba * cyst - pseudocyst Subject RIV: CE - Biochemistry OBOR OECD: Biochemistry and molecular biology Impact factor: 2.794, year: 2016

  13. Development of an Immunochromatographic Assay Kit Using Fluorescent Silica Nanoparticles for Rapid Diagnosis of Acanthamoeba Keratitis

    Science.gov (United States)

    Toriyama, Koji; Inoue, Tomoyuki; Eguchi, Hiroshi; Hoshi, Saichi; Inoue, Yoshitsugu; Aizawa, Hideki; Miyoshi, Kazutomi; Ohkubo, Michio; Hiwatashi, Eiji; Tachibana, Hiroshi; Ohashi, Yuichi

    2014-01-01

    We developed an immunochromatographic assay kit that uses fluorescent silica nanoparticles bound to anti-Acanthamoeba antibodies (fluorescent immunochromatographic assay [FICGA]) and evaluated its efficacy for the detection of Acanthamoeba and diagnosis of Acanthamoeba keratitis (AK). The sensitivity of the FICGA kit was evaluated using samples of Acanthamoeba trophozoites and cysts diluted to various concentrations. A conventional immunochromatographic assay kit with latex labels (LICGA) was also evaluated to determine its sensitivity in detecting Acanthamoeba trophozoites. To check for cross-reactivity, the FICGA was performed by using samples of other common causative pathogens of infectious keratitis, such as Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, and Candida albicans. Corneal scrapings from patients with suspected AK were tested with the FICGA kit to detect the presence of Acanthamoeba, and the results were compared with those of real-time PCR. The FICGA kit detected organisms at concentrations as low as 5 trophozoites or 40 cysts per sample. There were no cross-reactivities with other pathogens. The FICGA was approximately 20 times more sensitive than the LICGA for the detection of Acanthamoeba trophozoites. The FICGA kit yielded positive results for all 10 patients, which corresponded well with the real-time PCR results. The FICGA kit demonstrated high sensitivity for the detection of Acanthamoeba and may be useful for the diagnosis of AK. PMID:25392356

  14. Azithromycin and Doxycycline Attenuation of Acanthamoeba Virulence in a Human Corneal Tissue Model.

    Science.gov (United States)

    Purssell, Andrew; Lau, Rachel; Boggild, Andrea K

    2017-04-15

    Amoebic keratitis is a potentially blinding eye infection caused by ubiquitous, free-living, environmental acanthamoebae, which are known to harbor bacterial endosymbionts. A Chlamydia-like endosymbiont has previously enhanced Acanthamoeba virulence in vitro. We investigated the potential effect of Acanthamoeba-endosymbiont coinfection in a human corneal tissue model representing clinical amoebic keratitis infection. Environmental and corneal Acanthamoeba isolates from the American Type Culture Collection were screened for endosymbionts by amplifying and sequencing bacterial 16S as well as Chlamydiales-specific DNA. Each Acanthamoeba isolate was used to infect EpiCorneal cells, a 3-dimensional human corneal tissue model. EpiCorneal cells were then treated with azithromycin, doxycycline, or control medium to determine whether antibiotics targeting common classes of bacterial endosymbionts attenuated Acanthamoeba virulence, as indicated by decreased observed cytopathic effect and inflammatory biomarker production. A novel endosymbiont closely related to Mycobacterium spp. was identified in Acanthamoeba polyphaga 50495. Infection of EpiCorneal cells with Acanthamoeba castellanii 50493 and A. polyphaga 50372 led to increased production of inflammatory cytokines and cytopathic effects visible under microscopy. These increases were attenuated by azithromycin and doxycycline. Our findings suggest that azithromycin and doxycycline may be effective adjuvants to standard antiacanthamoebal chemotherapy by potentially abrogating virulence-enhancing properties of bacterial endosymbionts. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  15. Isolation of an Acanthamoeba strain with intracellular Burkholderia pickettii infection.

    Science.gov (United States)

    Michel, R; Hauröder, B

    1997-04-01

    Burkholderia pickettii is a facultative pathogen that has been isolated from patient sources and environmental sources including respiratory therapy solutions, deionized water and aqueous disinfectants. The organism has been associated with septicemia and respiratory tract infections. In our investigation, Burkholderia pickettii (biovar 2) was for the first time isolated from Acanthamoeba sp. (group II), a free living amoeba species recovered from the wet area of a physiotherapy unit. Pathogenic strains of acanthamoebae may cause amoebic-encephalitis (AE) and keratitis. Light and electron microscopic examinations showed that in a first step, the bacterial were phagocytized by the amoebae. In contrast to Enterobacter cloacae and Escherichia coli that were used as food organisms and digested within food vacuoles, Burkholderia pickettii caused the amoebae to develop large vacuoles filled with completely intact and motile bacteria. 3-5 days after infection, Pseudomonas pickettii had multiplied within the enlarging parasitophorous vacuoles. Ultrastructural changes in the host cells occurred and the amoebae finally underwent rupture or lysis. In cocultivation assays we could not only reinfect the original host amoeba but Acanthamoeba strains from other habitats could successfully be infected with Burkholderia pickettii as well.

  16. Acanthamoeba griffini. Molecular characterization of a new corneal pathogen.

    Science.gov (United States)

    Ledee, D R; Hay, J; Byers, T J; Seal, D V; Kirkness, C M

    1996-03-01

    Acanthamoeba was isolated from the cornea of a soft contact lens wearer who had keratitis. The protozoan was also isolated from the contact lens storage case and the domestic water supply used to clean the case. Using morphologic features, all three isolates were identified tentatively as A. griffini, a species not previously associated with keratitis. Complete small subunit ribosomal RNA gene (18S rDNA) sequence analysis was used to characterize further the three isolates. 18S rDNA was polymerase chain reaction-amplified from whole cell DNA derived from amoebal lysates. The genes were cloned and sequenced. Complete sequences of approximately 2800 base pairs were obtained from each culture and compared wih those stored in a data base for homologous Acantamoeba sequences. The isolates were unequivocally identified as A. griffini both by comparison of the gene sequence available for the type strain of the species and the presence of a unique group I intron located within the small subunit rDNA. Sequences obtained for the three isolates were identical, indicating that they were the same strain. The first direct connection between human disease and A. griffini is reported from a case of Acanthamoeba keratitis. The type strain of this species was isolated from a marine environment, but the disease-causing strain ws isolated from a domestic water supply. The DNA sequences obtained confirmed unequivocally the epidemiologic association between a keratitis-causing strain of Acanthamoeba, the contact lens storage case, and the domestic water supply.

  17. Isolation of N-acetyl-beta-hexosaminidase from Acanthamoeba castellanii.

    Science.gov (United States)

    Baldwin, K M; Bowers, B

    1995-01-01

    The lysosomal enzyme N-acetyl-beta-hexosaminidase (beta hex) has been purified from Acanthamoeba castellanii growth medium by a three step procedure. The enzyme was precipitated with ammonium sulfate, partially purified on a DE52 column and purified to homogeneity on an affinity column. The purified beta hex appeared to be a monomer with a molecular mass of 58 kDa and a pI of approximately 5.8. The enzyme activity in growth medium at RT was stable for several months. The purified beta hex was enzymatically deglycosylated and injected into two rabbits to make polyclonal antibodies. One antiserum was specific for beta hex, but the other stained many bands on immunoblots of whole cell preparations. Using fluorescently labelled secondary antibodies we have determined that both antisera stain digestive vacuoles in the Acanthamoeba cytoplasm, and do not stain the contractile vacuole. The multi-specific antiserum had high avidity for beta hex, but also stained the carbohydrate portion of other molecules. These other molecules may be lysosomal enzymes as well, since the activity of several other lysosomal enzymes was partially immunoprecipitable with the antiserum. We plan to use these antibodies to study traffic patterns among the variety of vacuolar structures in Acanthamoeba cytoplasm.

  18. Susceptibility of Acanthamoeba to multipurpose lens-cleaning solutions.

    Science.gov (United States)

    de Aguiar, Ana Paula Costa; de Oliveira Silveira, Caroline; Todero Winck, Mari Aline; Rott, Marilise Brittes

    2013-09-01

    The present study investigated the susceptibility of Acanthamoeba spp. trophozoites to two multipurpose systems for cleaning and maintenance of contact lenses. Three strains of trophozoites from the ATCC (A. castellani T4, A. castellani Neff, and A. polyphaga) and two Acanthamoeba isolates obtained from swimming pools (PT5 and PO1) were placed in monoxenic culture. To test their survival in cleaning solutions for contact lenses, the trophozoites were exposed for 4 and 24 h to two multipurpose solutions (A and B), and were then inoculated into a new monoxenic culture. Amoebic growth on the plates was observed after 72 h of incubation. Trophozoites from all three ATCC strains and one isolate from a swimming pool (PO1) grew in all plates after 4 h of exposure to solutions A and B. After 24 h, the ATCC strains and the PO1 isolate showed growth in most of the plates treated. Only the PT5 isolate showed susceptibility to both solutions over the time intervals tested. The two solutions were not completely effective against most strains and isolates over the time intervals tested. These results are important, since species of Acanthamoeba are widely distributed in the environment and are potential agents of eye pathologies.

  19. Genotypic characterization of amoeba isolated from Acanthamoeba keratitis in Poland.

    Science.gov (United States)

    Derda, Monika; Solarczyk, Piotr; Cholewiński, Marcin; Hadaś, Edward

    2015-03-01

    Free-living amoebae belonging to the genus Acanthamoeba are the causative factor of many diseases. Among others, they cause Acanthamoeba keratitis (AK), a condition that usually occurs in contact lens wearers, though it is also observed in non-wearers. The number of diagnosed cases of AK increased more than eightfold during 8 years in the USA, and a proportional increase in frequency also occurred in Poland and Europe. Cases of AK are usually diagnosed late, and their therapy is difficult and rarely successful. AK is an uncommon diagnosis in Poland. The increased number of positive cases observed in our laboratory may reflect the growing at-risk population of contact lens wearers. Acanthamoeba as a genus of facultative human parasites is currently classified into 17 genotypes. Isolates belonging to seven genotypes were found to be associated with AK. One genotype in particular, T4, was found to be overrepresented in human disease. The main finding of our study is that in Poland, AK is almost always associated with the T4 genotype.

  20. Microsporidia and Acanthamoeba: the role of emerging corneal pathogens

    Science.gov (United States)

    Tu, E Y; Joslin, C E

    2012-01-01

    Parasitic organisms are increasingly recognized as human corneal pathogens. A notable increase in both well-defined Acanthamoeba keratitis and a more dramatic increase in reported cases of Microsporidia keratitis have suggested significant outbreaks of parasitic keratitis around the world. Historical and contemporary baselines as well as a familiar associated clinical presentation reinforce the significant outbreak of Acanthamoeba keratitis in the United States. The remarkable rise in cases of Microsporidia keratitis, however, lacks these established baselines and, further, describes a disease that is inconsistent with previous definitions of disease. While a well-defined, abrupt increase strongly suggests temporally related risk factors, most likely environmental, involved in the Acanthamoeba outbreak, the rise in Microsporidia keratitis suggests that increased awareness and improved diagnostic acumen are a significant factor in case ascertainment. Regardless, recent evidence indicates that both parasitic diseases are likely underreported in various forms of infectious keratitis, which may have unrecognized but significant implications in the pathogenesis of both primary protozoal and polymicrobial keratitis. Further understanding of the incidence and interaction of these organisms with current therapeutic regimens and more commonly recognized pathogens should significantly improve diagnosis and alter clinical outcomes. PMID:22173072

  1. Apoptosis of Acanthamoeba castellanii Trophozoites Induced by Oleic Acid.

    Science.gov (United States)

    Wu, Duo; Qiao, Ke; Feng, Meng; Fu, Yongfeng; Cai, Junlong; Deng, Yihong; Tachibana, Hiroshi; Cheng, Xunjia

    2018-03-01

    Acanthamoeba spp. can be parasitic in certain situations and are responsible for serious human infections, including Acanthamoeba keratitis, granulomatous amoebic encephalitis, and cutaneous acanthamoebiasis. We analyzed the fatty acid composition of Acanthamoeba castellanii trophozoites and tested the inhibitory activity of the main fatty acids, oleic acid and arachidonic acid, in vitro. Oleic acid markedly inhibited the growth of A. castellanii, with trophozoite viability of 57.4% at a concentration of 200 μM. Caspase-3 staining and annexin V assays showed that apoptotic death occurred in A. castellanii trophozoites. Quantitative PCR and dot blot analysis showed increased levels of metacaspase and interleukin-1β converting enzyme, which is also an indication of apoptosis. In contrast, arachidonic acid showed negligible inhibition of growth of A. castellanii trophozoites. Stimulated expression of Atg3, Atg8 and LC3A/B genes and monodansylcadaverine labeling suggested that oleic acid induces apoptosis by triggering autophagy of trophozoites. © 2017 The Author(s) Journal of Eukaryotic Microbiology © 2017 International Society of Protistologists.

  2. Partial characterization of Acanthamoeba castellanii (T4 genotype) DNase activity.

    Science.gov (United States)

    Iqbal, Junaid; Panjwani, Shamvil; Siddiqui, Ruqaiyyah; Khan, Naveed Ahmed

    2015-02-01

    The deoxyribonuclease (DNase) activities of Acanthamoeba castellanii belonging to the T4 genotype were investigated. Using zymographic assays, the DNase activities had approximate molecular masses of 25 and 35 kDa. A. castellanii DNases exhibited activity at wide-ranging temperature of up to 60 °C and at pH ranging from 4 to 9. The DNases activities were unaffected by proteinase-K treatment, divalent cations such as Ca(++), Cu(++), Mg(++), and Zn(++), or divalent cation chelating agent ethylenediaminetetraacetic acid (EDTA) or sodium dodecyl sulfate (SDS). The non-reliance on divalent cations and homology data suggests that A. castellanii DNases belong to the class of eukaryotic lysosomal DNase II but exhibit robust properties. The DNases activity in A. castellanii interfered with the genomic DNA extraction. Extraction methods involving EDTA, SDS, and proteinase-K resulted in low yield of genomic DNA. On the other hand, these methods resulted in high yield of genomic DNA from human cells suggesting the robust nature of A. castellanii DNases that are unaffected by reagents normally used in blocking eukaryotic DNases. In contrast, the use of chaotropic agent such as guanidine thiocyanate improved the yield of genomic DNA from A. castellanii cells significantly. Further purification and characterization of Acanthamoeba DNases is needed to study their non-classic distinct properties and to determine their role in the biology, cellular differentiation, cell cycle progression, and arrest of Acanthamoeba.

  3. Use of multiple immunosuppressive agents in recalcitrant ACANTHAMOEBA scleritis.

    Science.gov (United States)

    Igras, Estera; Murphy, Conor

    2015-04-15

    A 48-year-old woman who is a contact lens wearer presented with unilateral ACANTHAMOEBA keratitis, confirmed by PCR, which responded initially to topical polyhexamethylene biguanide (PHMB) and brolene. Three months later, despite continued treatment, she developed diffuse anterior scleritis with severe pain and marked scleral injection but without evidence of recurrence keratitis. Oral non-steroidal anti-inflammatories and oral high-dose corticosteroids were added without success. Subsequent treatment with intravenous methylprednisolone and high-dose cyclosporine led to a temporary improvement. Re-presenting with signs of recurrent scleritis and severe pain, the antitumor necrosis factor monoclonal antibody adalimumab, and later oral cyclophosphamide, were added. This led to complete quiescence of the scleritis. Unfortunately, frequent recurrences of ACANTHAMOEBA keratitis and anterior uveitis occurred on immunosuppression requiring continued treatment with PHMB, brolene and topical corticosteroids. This is the first case of severe refractory ACANTHAMOEBA scleritis requiring the concomitant use of four immunosuppressive agents to achieve continued disease control. The challenges in managing this case are discussed. 2015 BMJ Publishing Group Ltd.

  4. Effects of Lead Phytochemicals of Radix Scutellariae on Acanthamoeba.

    Science.gov (United States)

    Cho, Pauline; Shi, Guangsen; Yap, Maurice; Boost, Maureen V

    2016-12-01

    Acanthamoeba keratitis (AK), which is associated with noncompliant use of contact lenses, remains difficult to treat due to delayed diagnosis and paucity of therapeutic agents. Although improvements in activity against Acanthamoeba infection have been achieved in disinfecting solutions for soft contact lenses, such modifications have not been extended to those for special rigid gas permeable (RGP) contact lenses, which are increasingly used for myopia control in children. Phytochemicals present in herbs used for traditional Chinese medicine may be effective as therapeutic or preventive agents. The purpose of this study was to investigate amoebicidal properties of lead phytochemicals of Radix scutellariae alone and in combination with multipurpose (disinfecting) solutions (MPS) for RGP lenses. Viability of Acanthamoeba castellani and A. polyphaga trophozoites was determined following exposure to four phytochemicals: baicalin, baicalein, wogonoside, and oroxylin A and both alone and in combination with four RGP MPS, using a modified stand-alone technique. As individual agents, wogonoside and oroxylin A showed highest activity against A. castellani and A. polyphaga trophozoites, respectively. For both organisms, the combination of baicalein and oroxylin A was superior. Effectiveness of MPS alone did not exceed 0.27 log reduction, but addition of combined baicalein and oroxylin A resulted in 0.92 and 0.64 log reductions of A. castellani and A. polyphaga, respectively. The combination of baicalein and oroxylin A enhanced the activity of MPS for RGP contact lenses against trophozoites of two pathogens, A. castellani, and A. polyphaga, and offers a potential therapeutic and/or preventative agent for AK.

  5. Intoxicación por administración parenteral de insecticidas organoclorados e hidrocarburos aromáticos

    OpenAIRE

    F.J. Boluda; S. Nogué; J. Martínez Pérez; E. Muñoz

    2003-01-01

    La intoxicación por vía parenteral debida a insecticidas organoclorados e hidrocarburos aromáticos, es muy poco frecuente. La toxicidad comporta efectos locales y sistémicos que pueden llegar a comprometer la vida del paciente. Se presenta el caso clínico de un varón que desarrolló una importante reacción local necrótico-inflamatoria, con leve afectación sistémica hepática y renal, tras administrarse los mencionados productos por vía parenteral en una tentativa de suicidi...

  6. Close relatedness of Acanthamoeba pustulosa with Acanthamoeba palestinensis based on isoenzyme profiles and rDNA PCR-RFLP patterns.

    Science.gov (United States)

    Kim, Y H; Ock, M S; Yun, H C; Hwang, M Y; Yu, H S; Kong, H H; Chung, D I

    1996-12-01

    The taxonomic validity of morphological group III Acanthamoeba spp. is uncertain. In the present study, six type strains of group III Acanthamoeba spp., A. culbertsoni, A. healyi, A. pustulosa, A. palestinensis, A. royreba and A. lenticulata were subjected for the evaluation of their taxonomic validity by comparison of the isoenzyme patterns by isoelectic focusing on polyacrylamide gels, mitochondrial DNA (Mt DNA) restriction fragment length polymorphism (RFLP), and small subunit ribosomal DNA (ssu rDNA) PCR-RFLP patterns. The Mt DNA RFLP patterns were heterogeneous between the species. The type strains of A. palestinensis and A. pustulosa showed almost identical patterns of isoenzymes and rDNA PCR RFLP with an estimated sequence divergence of 2.6%. The other species showed heterogeneous patterns of isoenzymes and rDNA PCR-RFLP. It is likely that A. pustulosa is closely related with A. palestinensis and that the former may be regarded as a junior synonym of the latter.

  7. Voriconazole as a first-line treatment against potentially pathogenic Acanthamoeba strains from Peru.

    Science.gov (United States)

    Cabello-Vílchez, Alfonso Martín; Martín-Navarro, Carmen M; López-Arencibia, Atteneri; Reyes-Batlle, María; Sifaoui, Ines; Valladares, Basilio; Piñero, José E; Lorenzo-Morales, Jacob

    2014-02-01

    Pathogenic strains of Acanthamoeba genus are the causative agents of fatal granulomatous amoebic encephalitis and a serious sight-threatening infection of the eye known as Acanthamoeba keratitis. In a previous study, Acanthamoeba strains were isolated from nasal swabs collected from healthy individuals in Peru. In the present study, the pathogenic potential of the isolated strains was established based on temperature and osmotolerance assays as well as the secretion rate of extracellular proteases. Based on these experiments, four strains that showed the highest pathogenic potential were selected for sensitivity assays against two molecules (voriconazole and chlorhexidine) which are currently used for the treatment of Acanthamoeba infections. After performing sensitivity and activity assays, it was found that both drugs were active against the tested strains. However, voriconazole showed higher activity against the studied strains compared to chlorhexidine. Therefore, voriconazole should be established as a first-line treatment against Acanthamoeba infections at least in the studied region of Peru.

  8. New approach to diagnosis and treatment of Acanthamoeba keratitis--systematic review of literature.

    Science.gov (United States)

    Kokot, Joanna; Dobrowolski, Dariusz; Lyssek-Boroń, Anita; Milka, Michał; Smedowski, Adrian; Wójcik, Łukasz; Wowra, Bogumił; Wyligała, Edward

    2012-01-01

    To present new methods of diagnosis and treatment of Acanthamoeba keratitis. Searching Medline base for articles in English publicated since 2006 till the beginning of 2011, describing the way and results of diagnosis and treatment Acanthamoeba keratitis. Publications include studies, reviews as well as case reports concerning discussed subject. 14 publications were found and used to present miscellaneous methods utilized nowadays to identify the reason of Acanthamoeba keratitis with simultaneous evaluations of its' sensitivity and specificity. The review comprises improvements of laboratory diagnosis as well as corneal imaging systems helpful to diagnose infectious keratitis. 17 publications were quoted to elaborate results of pharmacological protocols as well as surgical procedures of Acanthamoeba keratitis treatment. Outcomes of experimental investigations were also cited. As none of presented methods of diagnosis and treatment of Acanthamoeba keratitis have become a standardized guideline jet, still there is a great need to look for new ones.

  9. Insights from the DNA databases: approaches to the phylogenetic structure of Acanthamoeba.

    Science.gov (United States)

    Fuerst, Paul A

    2014-11-01

    Species of Acanthamoeba have been traditionally described using morphology (primarily cyst structure), or cytology of nuclear division (used by Pussard and Pons, 1977). Twenty-plus putative species were proposed based on such criteria. Morphology, however, is often plastic, dependent upon culture conditions. DNA sequences of the nuclear small subunit (18S) rRNA that can be used for the study of the phylogeny of Acanthamoeba have increased from a single sequence in 1986 to more than 1800 in 2013. Some of the patterns of the sequence data for Acanthamoeba are reviewed, and some of the insights that this data illuminates are illustrated. In particular, the data suggest the existence of 20 or more genotypic types, a number not dissimilar to the number of named species of Acanthamoeba. However, molecular studies make clear that the relationship between phylogenetic relatedness and species names as we know them for Acanthamoeba is tenuous at best. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Characterisation and expression analysis of trophozoite and cyst proteins of Acanthamoeba spp. isolated from Acanthamoeba keratitis (AK) patient.

    Science.gov (United States)

    Behera, Himansu Sekhar; Satpathy, Gita

    2016-01-01

    The study was carried out to characterise and analyze the expression pattern of proteins of infective trophozoite and cyst forms of Acanthamoeba spp. isolated from an amoebic keratitis patient. Protein was isolated from the trophozoites and cysts of Acanthamoeba spp. isolates and subjected to SDS PAGE, 2D PAGE analysis where a large number of protein bands and protein spots were observed. Four prominent protein spots i.e. 2 from trophozoites and 2 from cysts that appeared more intense compared to the corresponding spots in other corresponding gel were excised from the 2D PAGE gels and analysed by MALDI-TOF/TOF MS assay and Mascot search software. Protein spots from trophozoites were identified as "hypothetical protein ACA1" and "eukaryotic porin protein" and those from cysts were identified as "chaperone protein DnaK" and "chaperonin protein" respectively. Proteomic results of 4 proteins were further validated by reverse genomics using quantitative real time PCR assay which showed a 1388 fold and 4.35 fold increase in expression of "hypothetical protein ACA1" gene and "eukaryotic porin protein" gene respectively in trophozoites compared to cysts and a 15 fold and 12.36 fold increase in expression of "chaperone protein DnaK" gene and "chaperonin protein" gene respectively in cysts compared to trophozoites. "Hypothetical protein ACA1" of trophozoites, whose function is unknown might have some important role in the parasite division and pathogenicty of Acanthamoeba spp. which needs further study. As trophozoites are the active and feeding form of Acanthamoeba spp., "eukaryotic porin" proteins may have some important role in efflux of toxic metabolites and exudates from interior of cell to outside along with some role in pathogenicity. Similarly proteins such as "chaperone protein DnaK" and "chaperonin protein" which belongs to group of heat shock proteins may have a role in folding of cyst specific proteins in cyst which needs further study. Copyright © 2016 Elsevier

  11. Number of Bacteria and Time of Coincubation With Bacteria Required for the Development of Acanthamoeba Keratitis.

    Science.gov (United States)

    Nakagawa, Hayate; Hattori, Takaaki; Koike, Naohito; Ehara, Tomoko; Narimatsu, Akitomo; Kumakura, Shigeto; Matsumoto, Tetsuya; Goto, Hiroshi

    2017-03-01

    We hypothesized that bacteria may be a factor contributing to the development of Acanthamoeba keratitis (AK). We investigated interactions between Acanthamoeba and Pseudomonas aeruginosa for the development of keratitis in rabbit corneas. Acanthamoeba castellanii (ATCC50492) and P. aeruginosa (PAO-1) were used. Two densities of P. aeruginosa (high, 1 × 10/mL; low, 3 × 10/mL) and 2 durations of coincubation (long, 6 h; short, 2 h) of Acanthamoeba with 1 × 10/mL of P. aeruginosa were tested. Acanthamoeba alone or Acanthamoeba coincubated with P. aeruginosa was inoculated into rabbit corneas. After inoculation, levofloxacin (LVFX) eye drops were administered. The clinical score of the cornea was evaluated after inoculation. Acanthamoeba alone did not produce keratitis during a 5-day observation period. Rabbit corneas inoculated with Acanthamoeba coincubated with low-density P. aeruginosa followed by topical LVFX were clear with few infiltrates. Corneas inoculated with Acanthamoeba coincubated with high-density P. aeruginosa followed by LVFX treatment developed severe keratitis, and clinical scores were significantly higher compared with high-density P. aeruginosa alone followed by LVFX treatment (scores 7, 9.6, 8.5 vs. 3, 3.5, 3.25 on days 1-3, all P Acanthamoeba with high-density P. aeruginosa resulted in more severe keratitis compared with short (2 h) coincubation (scores, 9.7, 12.7, 12.1, 9.8, 8.7 vs. 7, 9.6, 8.5, 6.9, 5.6 on days 1-5, all P < 0.01). These results suggest that the presence of bacteria is essential and a critical number of bacteria is required for the development of AK. The time of coexistence with bacteria may be an important determinant of the severity of AK.

  12. Identifying differentially expressed genes in trophozoites and cysts of Acanthamoeba T4 genotype: Implications for developing new treatments for Acanthamoeba keratitis.

    Science.gov (United States)

    Abedkhojasteh, Hoda; Niyyati, Maryam; Rezaei, Sasan; Mohebali, Mehdi; Farnia, Shohreh; Kazemi-Rad, Elham; Roozafzoon, Reza; Sianati, Hamed; Rezaeian, Mostafa; Heidari, Mansour

    2015-02-01

    Acanthamoeba T4 genotype is the most prevalent genotype associated with amoebic keratitis. Acanthamoeba keratitis therapy is difficult due to transformation of trophozoite to cyst stage, which hinders the treatment of the disease. Although encystation assists the organism to survive against the chemotherapeutic compounds, the precise mechanism of encystation remains poorly understood. The purpose of this work was to identify differentially expressed genes in Acanthamoeba T4 genotype which might be useful for understanding of the encystment process and may thus help develop more efficient treatment. The mRNA profile of trophozoite and cyst of Acanthamoeba T4 genotype isolated from a soft contact lens wearer were analyzed using a cDNA amplified fragment length polymorphism (cDNA-AFLP) technique. Subsequently, a real time reverse transcriptase-PCR was performed to validate the cDNA-AFLP results. Three genes, heat shock protein70 (hsp70), actin-I and elongation factor-1alpha (EF-1α) were differentially expressed during Acanthamoeba differentiation. An in silico result predicted that transformation of trophozoite to cyst could be mediated through their cooperation with the protein partners interaction. Taken together, our experimental and bioinformatics findings suggested potential functions of hsp70, EF-1α and actin-I in differentiation of Acanthamoeba T4 genotype which may be useful in the design of an efficient therapeutic strategy in AK. Copyright © 2014 Elsevier GmbH. All rights reserved.

  13. Calprotectina fecal como predictor de recidiva en pacientes con Enfermedad Inflamatoria Intestinal en remisión a tratamiento con biológicos

    OpenAIRE

    Ferreiro Iglesias, Rocío

    2017-01-01

    Introducción: Monitorizar pacientes con enfermedad inflamatoria intestinal (EII) con calprotectina fecal (CF) para predecir recidiva puede ser útil en la práctica clínica. El objetivo de este estudio fue evaluar el valor predictivo de un test rápido de CF para predecir recidiva o remisión clínica en pacientes con EII a tratamiento con fármacos anti-factor de necrosis tumoral. Métodos: Se diseñó un estudio de cohortes prospectivo y observacional. Se incluyeron pacientes con EII en remisión cl...

  14. Eficacia del primer tratamiento sistémico con glucocorticoides en la enfermedad inflamatoria intestinal. Revisión sistemática y serie de casos

    OpenAIRE

    López San Román, Antonio

    2009-01-01

    Los glucocorticoides son un fármaco de eficacia alta en pacientes con enfermedad inflamatoria intestinal, consiguiendo inducir respuesta en aproximadamente un 70% de los pacientes, respuesta que perdura a largo plazo en casi la mitad de los casos. La mayor edad al diagnóstico y al inicio del primer tratamiento son los principales factores predoctores de mala respuesta a los glucocorticoides. Una política de inmunosupresión precoz de los pacientes que no se hubieran beneficiado a largo plazo d...

  15. Situaciones especiales en la enfermedad inflamatoria intestinal: primer consenso latinoamericano de la Pan American Crohn's and Colitis Organisation (PANCCO (Segunda parte

    Directory of Open Access Journals (Sweden)

    J.K. Yamamoto-Furusho

    2017-04-01

    Full Text Available Este es el primer Consenso Latinoamericano de la Pan American Crohn's and Colitis Organisation (PANCCO que corresponde a situaciones especiales en pacientes con enfermedad inflamatoria intestinal (EII. El objetivo de este consenso es concientizar a la comunidad médica de todos los países de América Latina acerca del embarazo, la vacunación, las infecciones y las neoplasias, incluyendo el cáncer colorrectal, así como los aspectos pediátricos en pacientes con EII.

  16. Estudio de prevalencia de las manifestaciones cutáneas de la enfermedad inflamatoria intestinal (EII) en el Principado de Asturias

    OpenAIRE

    Hidalgo García, Yolanda

    2016-01-01

    La enfermedad inflamatoria intestinal (EII) es un término general que se aplica a un grupo de enfermedades crónicas de etiología desconocida que afectan al tubo digestivo, evolucionan de modo recurrente, con brotes y remisiones y pueden presentar diversas complicaciones y manifestaciones extradigestivas. La enfermedad de Crohn (EC) y la colitis ulcerosa (CU) son las dos formas principales de EII. Ambas presentan una distinta patogenia, sintomatología, perfil inflamatorio y localización intest...

  17. Papel de la ventilación mecánica durante la circulación extracorporea sobre los mediadores de la respuesta inflamatoria

    OpenAIRE

    López Gomez, Amparo

    2015-01-01

    RESUMEN TESIS: PAPEL DE LA VENTILACIÓN MECÁNICA DURANTE LA CIRCULACIÓN EXTRACORPÓREA SOBRE LOS MEDIADORES DE LA RESPUESTA INFLAMATORIA. La Cardiopatía Isquémica (CI) representa la mayor causa de mortalidad en países desarrollados. En España, supone el mayor número de muertes cardiovasculares, siendo el infarto agudo de miocardio (IMA) la enfermedad isquémica más frecuente. Datos recientes sugieren que se ha producido un aumento de la prevalencia de pacientes con CI . La revasculariza...

  18. Genotypic, physiological, and biochemical characterization of potentially pathogenic Acanthamoeba isolated from the environment in Cairo, Egypt.

    Science.gov (United States)

    Tawfeek, Gihan Mostafa; Bishara, Sawsan Abdel-Hamid; Sarhan, Rania Mohammad; ElShabrawi Taher, Eman; ElSaady Khayyal, Amira

    2016-05-01

    Acanthamoebae are the most common opportunistic amphizoic protozoa that cause life-threatening granulomatous amoebic encephalitis in immunocompromised individuals and sight-threatening amoebic keratitis (AK) in contact lens wearers. The present work aimed to determine the presence of Acanthamoeba isolates in different environmental sources: water, soil, and dust in Cairo, Egypt and to characterize the pathogenic potential of the isolated Acanthamoeba using physiological and biochemical assays as well as determination of the genotypes in an attempt to correlate pathogenicity with certain genotypes. The study included the collection of 22 corneal scrapings from patients complaining of symptoms and signs indicative of acanthamoeba keratitis (AK) and 75 environmental samples followed by cultivation on non-nutrient agar plates preseeded with E. coli. Positive samples for Acanthamoeba were subjected to osmo- and thermo-tolerance assays and zymography analysis. Potentially pathogenic isolates were subjected to PCR amplification using genus-specific primer pair. Isolates were classified at the genotype level based on the sequence analysis of Acanthamoeba 18S rRNA gene (diagnostic fragment 3). The total detection rate for Acanthamoeba in environmental samples was 33.3 %, 31.4 % in water, 40 % in soil, and 20 % in dust samples. Three and two Acanthamoeba isolates from water and soil sources, respectively, had the potential for pathogenicity as they exhibited full range of pathogenic traits. Other 12 isolates were designated as weak potential pathogens. Only ten of the environmental isolates were positive in PCR and were classified by genotype analysis into T4 genotype (70 %), T3 (10 %) and T5 (20 %). Potential pathogens belonged to genotypes T4 (from water) and T5 (from soil) while weak potential pathogens belonged to genotypes T3 (from water) and T4 (from water and soil). Additionally, T7 genotype was isolated from keratitis patients. There is a considerable

  19. A population-based study on the incidence of inflammatory bowel disease in Oviedo (Northern Spain Incidencia de la enfermedad inflamatoria intestinal (EII en población general en el área de Oviedo

    Directory of Open Access Journals (Sweden)

    L. Rodrigo

    2004-05-01

    Full Text Available Objective: to assess the incidence of inflammatory bowel disease in Oviedo (Northern Spain, and to describe the clinical features of new patients. Patients and methods: a prospective population-based study was made at the Health Area IV, Principality of Asturias (Oviedo, 312,324 inhabitants. All new diagnosed patients with inflammatory bowel disease were registered over a 2-year period. Results: a total of 85 patients were included, 47 of these with ulcerative colitis (UC, 37 with Crohn's disease (CD, and 1 with undetermined colitis. The overall adjusted incidence rate of UC and CD per 10(5 inhabitants between 15-64 years was 9.1 (95% CI: 5-13.1 and 7.5 (95% CI: 3.8-11.2, respectively. The global male/female ratio was 0.9, without significant differences between both diseases. CD patients were younger than those with UC (33 ± 15 years vs 45 ± 20 years; p Objetivo: conocer la incidencia de enfermedad inflamatoria intestinal en el área de Oviedo y describir las características clínicas de los nuevos pacientes. Pacientes y métodos: estudio prospectivo poblacional en el Área Sanitaria IV del Principado de Asturias (Oviedo, 312.324 habitantes. Fueron registrados todos los pacientes nuevos diagnosticados de enfermedad inflamatoria intestinal en un periodo de 2 años consecutivos. Resultados: se incluyeron un total de 85 pacientes, 47 con colitis ulcerosa (CU, 37 con enfermedad de Crohn (EC y 1 con colitis indeterminada (CI. La tasa de incidencia ajustada por 10(5 habitantes entre 15 y 64 años, de CU y EC, fue de 9,1 para CU (IC95%: 5-13,1 y 7,5 para la EC (IC95%: 3,8-11,2. La proporción hombre/mujer fue de 0,9, sin diferencias significativas entre ambas enfermedades. Los pacientes con EC eran más jóvenes que los que tenían CU (33 ± 15 años vs 45 ± 20 años; p<0,05. La mayor parte de los pacientes con EC tenían menos de 35 años (65%, mientras que los que presentaban CU fueron diagnosticados entre los 25 y 64 años (81%. La extensi

  20. Inflamación intestinal y dismotilidad en un modelo experimental de enfermedad inflamatoria intestinal en la rata mecanismos de acción implicados en la ciclicidad y cronicidad /

    OpenAIRE

    Porras Pardo, Mònica

    2006-01-01

    Bajo el nombre de Enfermedad Inflamatoria Intestinal (EII) se agrupan dos patologías inflamatorias crónicas y recidivantes de etiología desconocida: la enfermedad de Crohn y la colitis ulcerosa. La relativamente elevada incidencia de estas patologías hace que estudiar su etiopatogenia sea un objetivo importante, ya que actualmente no existe ningún tratamiento curativo y/o que prevenga la recidiva A pesar de que los pacientes afectados de EII presentan síntomas relacionados con alteraciones de...

  1. Interferon beta-1a in chronic inflammatory demyelinating polyneuropathy: case report Interferon beta en polineuropatía crónica inflamatoria desmienlinizante: caso clínico

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    Andrés Maria Villa

    2004-09-01

    Full Text Available Chronic inflammatory demyelinating polyneuropathy (CIDP is an acquired immune-mediated neuropathy. It presents with a course of progression which may be slow and steady or step-wise or relapsing. Sensory ataxic polyneuropathy may be the only clinical manifestation of this disease. Treatment with interferon beta1a (INF beta1a has been tried with different results in patients who were refractory to other, more conventional, immunomodulatory therapies. Here we report on a patient who had a relapsing form of pure sensory ataxic CIDP and who failed to respond to intravenous human immunoglobulin. He was put on INF beta1a for 3 years. During this period he suffered no relapses while his condition stabilized.La polineuropatía crónica inflamatoria desmielinizante (PCID es una neuropatía inmuno-mediada, que presenta un curso clínico primariamente progresivo o en forma de recaídas. Las manifestaciones sensoriales pueden ser su unica forma de expresión clínica. El tratamiento con interferon beta 1a (IFN beta1a ha sido ensayado en varias oportunidades, con diferentes respuestas terapéuticas, en pacientes refractarios a las terapias inmunomoduladoras convencionales. Nosotros comunicamos un paciente con una forma ataxica recurrente de PCID, que no respondió al tratamiento con inmunoglobulina endovenosa. Posteriormente fue tratado con IFN beta 1 a por tres años. Durante el período de seguimiento no mostró nuevas recaídas y su cuadro neurológico se estabilizó.

  2. Isolation and genotyping of Acanthamoeba spp. from recreational soil of parks in Tehran, Iran

    Directory of Open Access Journals (Sweden)

    M Niyyati

    2013-11-01

    Full Text Available Background & aim: Acanthamoeba is a genus of free-living amoebae found in environmental sources. These amphizoic amoebae can lead to severe human disease such as encephalitis and keratitis. Acanthamoeba transmits to humans through contact with soil and dust from scratching the skin. The aim of the present study was to identify the genotypes of Acanthamoeba in parks of the city of Tehran using molecular and morphological - based methods. Methods: In this study, 52 samples of soil were collected from 17 parks in Tehran. Samples were then filtered and cultured on 1.5% non-nutrient agar. DNA extraction and PCR amplification was performed using genus specific primers. Sequencing analysis and BLAST search were done for genotype identification. Results: Out of 52 soil samples, 14 strain (26.9% were positive for Acanthamoeba amoebae by microscopic observation. Out Of 14 positive isolates, 9 (17.3% were positive for Acanthamoeba using genus specific primer pairs. Of 14 strains, 9 were sequenced successfully. Genotype identification was revealed that all strains were belonged to T4 type. T4 genotypes among strains are human pathogens. Conclusions: Identification of pathogenic Acanthamoeba belonging to T4 genotype in recreational parks could be of utmost importance. Results of this study show that soil contamination, particularly in parks where children play and assemble is a sanitary risk for them. Key words: Acanthamoeba, Genotypes, Soil, Park

  3. Efficacy of miltefosine for topical treatment of Acanthamoeba keratitis in Syrian hamsters.

    Science.gov (United States)

    Polat, Zubeyde Akın; Obwaller, Andreas; Vural, Ayse; Walochnik, Julia

    2012-02-01

    Acanthamoeba keratitis is a painful corneal infection and difficult to treat because no sufficiently efficient drug has yet been available. The aim of the study therefore was to assess the therapeutic potential of miltefosine on Acanthamoeba keratitis-infected hamster eyes. The cornea of hamsters were infected with Acanthamoeba hatchetti, a human corneal isolate. On the fifth day, all the cornea were microscopically examined in order to determine the degree of infections (G, from 0 to 3). Four groups were then prepared: miltefosine (160 μM); 0.1% propamidine isetionate plus 0.02% polyhexnide; infected control (0.05% ethanol in PBS) and a non-infected control (0.05% ethanol in PBS) groups. The treatment was continued for 28 days. After the treatment, the cornea were excised and used for Acanthamoeba culture to investigate the presence of Acanthamoeba growth. Miltefosine treatment yielded much higher cure scores than propamidine isetionate plus polyhexanide. On the last day of treatment, 85% of the miltefosine-treated eyes were graded as G0; no changes were observed in the uninfected control group eyes; G3 eyes showed only a partial improvement. Furthermore, no Acanthamoeba cells could be recovered from the miltefosine-treated eye samples. Miltefosine appeared to hold necessary therapeutic properties for the treatment of Acanthamoeba keratitis.

  4. [In vivo confocal microscopy: a new tool for the diagnosis of Acanthamoeba keratitis].

    Science.gov (United States)

    Grise-Dulac, A; Brasnu, E; Goldchmidt, P; Dupas, B; Labbe, A; Borderie, V; Borsali, E; Chaumeil, C; Baudouin, C

    2010-06-01

    To study the usefulness of in vivo confocal microscopy imaging for the diagnosis of Acanthamoeba keratitis. A retrospective review of 50 cases of Acanthamoeba keratitis followed at the Quinze-Vingts National Ophthalmology Hospital from January 2005 to July 2008 was conducted. Gender, age, contact lens wear, best-corrected visual acuity before and after treatment, slit-lamp examination findings, corneal scrapings for biological analysis, and in vivo confocal microscopy images were analyzed. Nearly 82% of the cases of keratitis had a history of contact lens wear. Polymerase chain reaction (PCR) was positive for 40% of the samples. Heidelberg Retinal Tomograph II-Rostock Cornea Module (HRTII-RCM) examination detected images evoking Acanthamoeba cyst-like images in 84% of the cases. When the quality of biological samples was inadequate, the assessment of Acanthamoeba cysts using in vivo confocal microscopy made it possible to orient the diagnosis and to partially explain favorable progression under treatment. This technique showed images suggesting combined Acanthamoeba and fungal keratitis. HRTII-RCM in vivo confocal microscopy is a non invasive and rapid technique that may be helpful for the diagnosis of Acanthamoeba keratitis, especially when laboratory testing is not contributive and when Acanthamoeba keratitis is combined with a fungal infection. Copyright (c) 2010 Elsevier Masson SAS. All rights reserved.

  5. Evaluation of three different methods to establish animal models of Acanthamoeba keratitis.

    Science.gov (United States)

    Ren, Meiyu; Wu, Xinyi

    2010-01-01

    To produce animal models of Acanthamoeba keratitis and to evaluate the advantages and adaptation range of each of the three methods employed. Mice and Wistar rats in three groups of 15 rats and 15 mice each were used to establish the models. Right corneas in group A were scratched and challenged with Acanthamoeba. Those in group B were scratched and covered with contact lenses incubated with Acanthamoeba. Those in group C received an intrastromal injection of Acanthamoeba. Five rats and 5 mice in each group were used for histopathological investigations and the other 10 in each group were used for clinical evaluation. The models were evaluated by slit lamp examination, microscopic examination and culture of corneal scrapings, HE staining of corneal sections, and pathological scoring of the infections. Four rats and 6 mice in group A, 7 rats and 8 mice in group B, and 10 rats and 10 mice in group C developed typical Acanthamoeba keratitis. Corneal scratching alone has the lowest infection rate, while scratching and then covering with contaminated contact lenses has a moderate rate of infection and most closely mimics what happens in most human infections. Intrastromal injection of Acanthamoeba gives a much higher infection rate and more severe Acanthamoeba keratitis.

  6. A Case of Non-Contact Lens related Acanthamoeba keratitis in Malaysia

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    Mohamed Kamel, A. G.

    2005-01-01

    Full Text Available Acanthamoeba is a ubiquitous free-living amoeba and is responsible for an uncommon yet increasingly diagnosed keratitis in humans. Acanthamoeba keratitis is perhaps the most challenging ocular infection to manage successfully and it can result in permanently impaired vision or blindness. Although contact lens use is the principal risk factor, about 10% of cases occur following trauma and exposure to contaminated soil or water. Cases of Acanthamoeba keratitis involving contact lens wearers have previously been reported in Malaysia but this is the first time, a non-contact lens relatedAcanthamoeba keratitis is reported. The case involved a 28 year old Indonesian male construction worker who had a trauma of the right eye. While working his eye was struck by some sand and dust particles and he quickly washed his eye with water from an open tank at the construction site. He then experienced pain, redness, glaring and blurring of vision of the right eye. The diagnosis was missed at the initial presentation but subsequent culture of the corneal scraping demonstrated Acanthamoeba as the aetiological agent. The history, clinical findings, diagnosis and treatment of non-contact lens related Acanthamoeba keratitis are briefly discussed in this communication. We hope to create awareness especially among the medical and paramedical staff about the existence of this infection in the country and fully support the consideration of Acanthamoeba keratitis as part of the differential diagnosis of most cases of presumed microbial keratitis.

  7. Potential Value of Cellulose Synthesis Inhibitors Combined With PHMB in the Treatment of Acanthamoeba Keratitis.

    Science.gov (United States)

    Moon, Eun-Kyung; Hong, Yeonchul; Chung, Dong-Il; Goo, Youn-Kyoung; Kong, Hyun-Hee

    2015-12-01

    The aim of this study was to improve the cytopathic effect (CPE) of antiamebic agents by combining with cellulose synthesis inhibitor as an encystation inhibitor. Cellulose synthesis inhibitors, 2,6-dichlorobenzonitrile (DCB) and isoxaben were used to block encystation of Acanthamoeba during cultivation. Cultured human corneal epithelial (HCE) cells and Acanthamoeba were treated with polyhexamethylene biguanide (PHMB) combined with cellulose synthesis inhibitors to evaluate the CPE as an antiamebic agent. 0.02% PHMB showed a 51.9% CPE on HCE cells within 30 minutes but exhibited significant toxic effects on Acanthamoeba. At a level of 0.00125%, PHMB had no significant CPEs on HCE cells, whereas 100 μM DCB and 10 μM isoxaben significantly inhibited the formation of the inner cyst wall of Acanthamoeba during encystation, and Acanthamoeba trophozoites failed to convert into mature cysts. Although a low concentration (0.00125%) of PHMB was used, the novel combinations with 100 μM DCB or 10 μM isoxaben had 23.4% or 18.7% additional amebicidal effects on Acanthamoeba. However, 100 μM DCB and 10 μM isoxaben had no CPEs on HCE cells. The combination of cellulose synthesis inhibitors with low concentrations of PHMB reduced the CPE on HCE cells and improved the amebicidal effect on Acanthamoeba by inhibition of encystation.

  8. Artemether Exhibits Amoebicidal Activity against Acanthamoeba castellanii through Inhibition of the Serine Biosynthesis Pathway.

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    Deng, Yihong; Ran, Wei; Man, Suqin; Li, Xueping; Gao, Hongjian; Tang, Wei; Tachibana, Hiroshi; Cheng, Xunjia

    2015-08-01

    Acanthamoeba sp. parasites are the causative agents of Acanthamoeba keratitis, fatal granulomatous amoebic encephalitis, and cutaneous infections. However, there are currently no effective drugs for these organisms. Here, we evaluated the activity of the antimalarial agent artemether against Acanthamoeba castellanii trophozoites and identified potential targets of this agent through a proteomic approach. Artemether exhibited in vitro amoebicidal activity in a time- and dose-dependent manner and induced ultrastructural modification and cell apoptosis. The iTRAQ quantitative proteomic analysis identified 707 proteins that were differentially expressed after artemether treatment. We focused on phosphoglycerate dehydrogenase and phosphoserine aminotransferase in the serine biosynthesis pathway because of their importance to the growth and proliferation of protozoan and cancer cells. The expression of these proteins in Acanthamoeba was validated using quantitative real-time PCR and Western blotting after artemether treatment. The changes in the expression levels of phosphoserine aminotransferase were consistent with those of phosphoglycerate dehydrogenase. Therefore, the downregulation of phosphoserine aminotransferase may be due to the downregulation of phosphoglycerate dehydrogenase. Furthermore, exogenous serine might antagonize the activity of artemether against Acanthamoeba trophozoites. These results indicate that the serine biosynthesis pathway is important to amoeba survival and that targeting these enzymes would improve the treatment of Acanthamoeba infections. Artemether may be used as a phosphoglycerate dehydrogenase inhibitor to control or block Acanthamoeba infections. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  9. Abietane diterpenoids from Salvia sclarea transformed roots as growth inhibitors of pathogenic Acanthamoeba spp.

    Science.gov (United States)

    Kuźma, Łukasz; Derda, Monika; Hadaś, Edward; Wysokińska, Halina

    2015-01-01

    Amoebae from the genus Acanthamoeba are known agents leading to various diseases such as granulomatous amoebic encephalitis (GAE), a chronic progressive disease of the central nervous system, amoebic keratitis (AK), chronic eye infection, amoebic pneumitis (AP), chronic lung infection, and skin infections. It is known that various synthetic anti-Acanthamoeba substances are ineffective. Therefore, other substances, e.g., natural plant compounds, are the focus of biological investigations regarding anti-parasite activity. In this work, the ability of four abietane diterpenoids (ferruginol, salvipisone, aethiopinone, and 1-oxo-aethiopinone) to inhibit Acanthamoeba growth is reported. All investigated compounds were active against Acanthamoeba growing in vitro. Among them, ferruginol demonstrated the highest activity against Acanthamoeba. This compound inhibited Acanthamoeba growth by about 72% in a 3-day exposure period (IC50 17.45 μM), while aethiopinone and 1-oxo-aethiopinone demonstrated this activity at the level of 55-56%. Salvipisone reduced the growth of Acanthamoeba in vitro culture by 39%. For this compound, the value of IC50 was 701.94 μM after 72 h of exposure.

  10. The Acanthamoeba spp. in Water Sources from Zanjan Province, Northwest of Iran

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    Ali Haniloo

    2017-06-01

    Full Text Available Background: The genus of Acanthamoeba is an opportunistic protozoan parasite with a worldwide distribution where it is able to cause fatal granulomatous amoebic encephalitis (GAE and amoebic keratitis (AK. This organism inhabits in the wide range of natural and man-made aquatic environments. The present study was carried out to evaluate the presence of Acanthamoeba spp. in the various water resources of Zanjan province, northwest Iran, using both morphological and molecular methods. Methods: The Water samples were randomly collected from 30 water sources in different parts of Zanjan, Iran, between April 2015 and May 2016. Then, the samples were cultured on non-nutrient agar and the Acanthamoeba genus identified by morphological characters. The polymerase chain reaction (PCR was performed using the 18S rRNA gene as a molecular marker. Results: The obtained data showed that, out of the 60 water samples collected, 30 (50% were positive for Acanthamoeba spp. According to morphological and molecular approaches. Conclusion: The present investigation is the first report of the distribution of Acanthamoeba spp. in the various water sources of Zanjan province, gives baseline knowledge regarding water contamination with Acanthamoeba spp. in these areas and emphasizes the necessity of more attention to water sources in order to prevent infections associated with Acanthamoeba spp.

  11. Loop-Mediated Isothermal Amplification Targeting 18S Ribosomal DNA for Rapid Detection of Acanthamoeba

    Science.gov (United States)

    Yang, Hye-Won; Lee, Yu-Ran; Inoue, Noboru; Jha, Bijay Kumar; Danne, Dinzouna-Boutamba Sylvatrie; Kim, Hong-Kyun; Lee, Junhun; Goo, Youn-Kyoung; Kong, Hyun-Hee; Chung, Dong-Il

    2013-01-01

    Amoebic keratitis (AK) caused by Acanthamoeba is one of the most serious corneal infections. AK is frequently misdiagnosed initially as viral, bacterial, or fungal keratitis, thus ensuring treatment delays. Accordingly, the early detection of Acanthamoeba would contribute significantly to disease management and selection of an appropriate anti-amoebic therapy. Recently, the loop-mediated isothermal amplification (LAMP) method has been applied to the clinical diagnosis of a range of infectious diseases. Here, we describe a rapid and efficient LAMP-based method targeting Acanthamoeba 18S rDNA gene for the detection of Acanthamoeba using clinical ocular specimens in the diagnosis of AK. Acanthamoeba LAMP assays detected 11 different strains including all AK-associated species. The copy number detection limit for a positive signal was 10 DNA copies of 18S rDNA per reaction. No cross-reactivity with the DNA of fungi or other protozoa was observed. The sensitivity of LAMP assay was higher than those of Nelson primer PCR and JDP primer PCR. In the present study, LAMP assay based on directly heat-treated samples was found to be as efficient at detecting Acanthamoeba as DNA extracted using a commercial kit, whereas PCR was only effective when commercial kit-extracted DNA was used. This study showed that the devised Acanthamoeba LAMP assay could be used to diagnose AK in a simple, sensitive, and specific manner. PMID:23864737

  12. Acanthamoeba spp. in Contact Lenses from Healthy Individuals from Madrid, Spain.

    Science.gov (United States)

    Gomes, Thiago Dos Santos; Magnet, Angela; Izquierdo, Fernando; Vaccaro, Lucianna; Redondo, Fernando; Bueno, Sara; Sánchez, Maria Luisa; Angulo, Santiago; Fenoy, Soledad; Hurtado, Carolina; Del Aguila, Carmen

    2016-01-01

    Acanthamoeba keratitis (AK) is a painful and potentially blinding corneal infection caused by Acanthamoeba spp. In Madrid, environmental studies have demonstrated a high presence of these free-living amoebae in tap water. Since most of AK cases occur in contact lenses (CL) wearers with inadequate hygiene habits, the presence of Acanthamoeba in discarded CL has been studied and compared with other common etiological agents of keratitis, such as Pseudomonas aeruginosa and Staphylococcus aureus. One hundred and seventy-seven healthy individuals from Madrid contributed their discarded CL and answered a questionnaire on hygiene habits. DNA was extracted from the CL solution and analyzed by real-time PCR for Acanthamoeba, Pseudomonas aeruginosa and Staphylococcus aureus. These CL and their solutions were also cultured on non-nutrient agar to isolate Acanthamoeba. Among the 177 samples, Acanthamoeba DNA was detected in 87 (49.2%), P. aeruginosa DNA in 14 (7.9%) and S. aureus DNA in 19 (10.7%). Cultivable amoebae, however, were observed in only one sample (0.6%). This isolate was genotyped as T4. The habits reported by this CL owner included some recognized risk factors for AK, but in this study only the practice of "not cleaning the CL case" presented some statistical significant association with Acanthamoeba DNA presence. Detection of the investigated bacterial DNA did not demonstrate statistical significant association with the studied practices, but the presence of P. aeruginosa revealed a possible inhibition of Acanthamoeba in these samples. The PCR results suggest a high presence of Acanthamoeba spp. in healthy CL wearers from Madrid, but we can assume that CL solutions are properly disinfecting the CL since only 1.1% of the positive PCR samples correspond to viable amoebae and, after four years, only one participant reported stronger ocular problems. Nevertheless, more studies are necessary to corroborate this hypothesis.

  13. Acanthamoeba spp. in Contact Lenses from Healthy Individuals from Madrid, Spain.

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    Thiago Dos Santos Gomes

    Full Text Available Acanthamoeba keratitis (AK is a painful and potentially blinding corneal infection caused by Acanthamoeba spp. In Madrid, environmental studies have demonstrated a high presence of these free-living amoebae in tap water. Since most of AK cases occur in contact lenses (CL wearers with inadequate hygiene habits, the presence of Acanthamoeba in discarded CL has been studied and compared with other common etiological agents of keratitis, such as Pseudomonas aeruginosa and Staphylococcus aureus.One hundred and seventy-seven healthy individuals from Madrid contributed their discarded CL and answered a questionnaire on hygiene habits. DNA was extracted from the CL solution and analyzed by real-time PCR for Acanthamoeba, Pseudomonas aeruginosa and Staphylococcus aureus. These CL and their solutions were also cultured on non-nutrient agar to isolate Acanthamoeba.Among the 177 samples, Acanthamoeba DNA was detected in 87 (49.2%, P. aeruginosa DNA in 14 (7.9% and S. aureus DNA in 19 (10.7%. Cultivable amoebae, however, were observed in only one sample (0.6%. This isolate was genotyped as T4. The habits reported by this CL owner included some recognized risk factors for AK, but in this study only the practice of "not cleaning the CL case" presented some statistical significant association with Acanthamoeba DNA presence. Detection of the investigated bacterial DNA did not demonstrate statistical significant association with the studied practices, but the presence of P. aeruginosa revealed a possible inhibition of Acanthamoeba in these samples.The PCR results suggest a high presence of Acanthamoeba spp. in healthy CL wearers from Madrid, but we can assume that CL solutions are properly disinfecting the CL since only 1.1% of the positive PCR samples correspond to viable amoebae and, after four years, only one participant reported stronger ocular problems. Nevertheless, more studies are necessary to corroborate this hypothesis.

  14. Acanthamoeba spp. in Contact Lenses from Healthy Individuals from Madrid, Spain

    Science.gov (United States)

    Gomes, Thiago dos Santos; Magnet, Angela; Izquierdo, Fernando; Vaccaro, Lucianna; Redondo, Fernando; Bueno, Sara; Sánchez, Maria Luisa; Angulo, Santiago; Fenoy, Soledad; Hurtado, Carolina; del Aguila, Carmen

    2016-01-01

    Purpose Acanthamoeba keratitis (AK) is a painful and potentially blinding corneal infection caused by Acanthamoeba spp. In Madrid, environmental studies have demonstrated a high presence of these free-living amoebae in tap water. Since most of AK cases occur in contact lenses (CL) wearers with inadequate hygiene habits, the presence of Acanthamoeba in discarded CL has been studied and compared with other common etiological agents of keratitis, such as Pseudomonas aeruginosa and Staphylococcus aureus. Methods One hundred and seventy-seven healthy individuals from Madrid contributed their discarded CL and answered a questionnaire on hygiene habits. DNA was extracted from the CL solution and analyzed by real-time PCR for Acanthamoeba, Pseudomonas aeruginosa and Staphylococcus aureus. These CL and their solutions were also cultured on non-nutrient agar to isolate Acanthamoeba. Results Among the 177 samples, Acanthamoeba DNA was detected in 87 (49.2%), P. aeruginosa DNA in 14 (7.9%) and S. aureus DNA in 19 (10.7%). Cultivable amoebae, however, were observed in only one sample (0.6%). This isolate was genotyped as T4. The habits reported by this CL owner included some recognized risk factors for AK, but in this study only the practice of “not cleaning the CL case” presented some statistical significant association with Acanthamoeba DNA presence. Detection of the investigated bacterial DNA did not demonstrate statistical significant association with the studied practices, but the presence of P. aeruginosa revealed a possible inhibition of Acanthamoeba in these samples. Conclusions The PCR results suggest a high presence of Acanthamoeba spp. in healthy CL wearers from Madrid, but we can assume that CL solutions are properly disinfecting the CL since only 1.1% of the positive PCR samples correspond to viable amoebae and, after four years, only one participant reported stronger ocular problems. Nevertheless, more studies are necessary to corroborate this hypothesis. PMID

  15. Evaluation of immunoperoxidase staining technique in the diagnosis of Acanthamoeba keratitis

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    Sharma Savitri

    2001-01-01

    Full Text Available Purpose: We describe a simple procedure of Immunoperoxidase (IP technique, using indigenously raised antibody, to screen corneal scrapings for Acanthamoeba cysts and trophozoites. This study sought to determine the utility of this test in the diagnosis of Acanthamoeba keratitis. Methods: A high titre polyclonal antibody against a local clinical isolate (axenic of Acanthamoeba species (trophozoite lysate antigen was raised in rabbits and used for standardization of IP technique for corneal scrapings. Twenty two smears of corneal scrapings, collected from patients showing Acanthamoeba cysts in corneal scrapings stained with calcofluorwhite (pool-1 and patients showing no cysts in similar scrapings (pool-2, were coded and stained by IP technique by a masked technician. All 22 patients had also been tested for bacteria, fungus, and Acanthamoeba in their corneal scrapings by smears and cultures. IP stained smears were examined for organisms including cysts and trophozoites of Acanthamoeba and background staining by two observers masked to the results of other smears and cultures. The validity of the IP test in detection of Acanthamoeba cysts and trophozoites was measured by sensitivity, specificity, positive predictive value and negative predictive value in comparison (McNemar test for paired comparison with calcofluor white staining and culture. Results: Based on the readings of observer 1 and compared to calcofluor white staining, the IP test had a sensitivity of 100%, a specificity of 94%, positive predictive value of 80% and negative predictive value of 100%. When compared to culture, the values were 83%, 100%, 100% and 94% respectively. Trophozoites missed in calcofluor white stained smears, were detected in 2 out of 6 cases of culture-positive Acanthamoeba keratitis. The Kappa coefficient of interobserver agreement was determined as fair (30.4%. Conclusion: The immunoperoxidase technique is a simple and useful test in the diagnosis of

  16. Comparison of Validated Polymerase Chain Reaction and Culture Isolation for the Routine Detection of Acanthamoeba From Ocular Samples.

    Science.gov (United States)

    Kowalski, Regis P; Melan, Melissa A; Karenchak, Lisa M; Mammen, Alex

    2015-11-01

    Acanthamoeba keratitis should be definitively diagnosed for appropriate therapy. Our institution has validated polymerase chain reaction (PCR) as a routine diagnostic test to detect Acanthamoeba DNA from ocular samples. We compared PCR with culture isolation for detecting Acanthamoeba from ocular samples. The microbiology records of patients that had specimens submitted (May 2012 to January 2014) for laboratory testing for Acanthamoeba keratitis were reviewed for (1) Acanthamoeba culture isolation, (2) Acanthamoeba DNA detection by PCR, and (3) non-Acanthamoeba culture results. For Acanthamoeba isolation, corneal samples were planted on nonnutrient agar overlaid with Enterobacter aerogenes. Validated PCR (May 2012) for Acanthamoeba DNA was processed at the Division of Molecular Diagnostics, UPMC, Pittsburgh, PA. Additional cultures were obtained for bacteria, fungus, and virus (i.e., herpes simplex virus) using standard techniques. Culture isolation and PCR were processed on 125 patients with a differential diagnosis of Acanthamoeba keratitis. Of these, 104 (83.2%) were culture negative, PCR negative; 14 (11.2%) were culture positive, PCR positive; 4 (3.2%) were culture negative, PCR positive; and, 3 (2.4%) were culture positive, PCR negative. Culture and PCR were statistically equivalent for detecting Acanthamoeba from ocular samples (P=1.0, McNemar's test). Nineteen of the culture-negative, PCR-negative corneal samples (18.3%) were positive for other pathogens such as bacteria, fungus, and virus. There is no clear advantage of PCR over culture isolation for detecting Acanthamoeba in ocular specimens. Other pathogens such as bacteria, fungus, and virus must still be considered in severe persistent keratitis. Polymerase chain reaction seems to be a complementary test for the clinical support of Acanthamoeba keratitis.

  17. Acanthamoeba castellanii interactions with Streptococcus pneumoniae and Streptococcus pyogenes.

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    Siddiqui, Ruqaiyyah; Yee Ong, Timothy Yu; Jung, Suk Yul; Khan, Naveed Ahmed

    2017-12-01

    Among the genus Streptococcus, S. pyogenes and S. pneumoniae are the major causes of pharyngitis, impetigo, pneumonia and meningitis in humans. Streptococcus spp. are facultative anaerobes that are nutritionally fastidious, yet survive in the environment and target the predisposed population. Antibacterial disinfectants have been partially effective only, indicating the need for novel preventative measures and to understand mechanisms of bacterial resistance. Acanthamoeba is a free-living protist that is known to harbour microbial pathogens, provide shelter, and assist in their transmission to susceptible population. The overall aim of this study was to determine whether S. pyogenes and S. pneumoniae can interact with A. castellanii by associating, invading, and surviving inside trophozoites and cysts. It was observed that both S. pyogenes and S. pneumoniae were able to associate as well as invade and/or taken up by the phagocytic A. castellanii trophozoite. Notably, S. pyogenes and S. pneumoniae survived the encystation process, avoided phagocytosis, multiplied, and exhibited higher recovery from the mature cysts, compared with the trophozoite stage (approximately 2 bacteria per amoebae ratio for cyst stage versus 0.02 bacteria per amoeba ration for trophozoite stage). As Acanthamoeba cysts are resilient and can disperse through the air, A. castellanii can act as a vector in providing shelter, facilitating growth and possibly genetic exchanges. In addition, these interactions may contribute to S. pyogenes and S. pneumoniae survival in harsh environments, and transmission to susceptible population and possibly affecting their virulence. Future studies will determine the molecular mechanisms associated with Acanthamoeba interactions with Streptococcus and the evolution of pathogenic bacteria and in turn expedite the discovery of novel therapeutic and/or preventative measures. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Mechanisms associated with phagocytosis of Arcobacter butzleri by Acanthamoeba castellanii.

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    Medina, Gustavo; Flores-Martin, Sandra; Fonseca, Belchiolina; Otth, Carola; Fernandez, Heriberto

    2014-05-01

    Acanthamoeba castellanii is a free-living amoeba widely found in environmental matrices such as soil and water. Arcobacter butzleri is an emerging potential zoonotic pathogen that can be isolated from environmental water sources, where they can establish endosymbiotic relationships with amoebas. The aim of this study was to describe the implication of mannose-binding proteins and membrane-associated receptors of glucose and galactose present in the amoebic membrane, during the attachment of Arcobacter butzleri by blocking with different saccharides. Another objective was to describe the signaling pathways involved in phagocytosis of these bacteria using specific inhibitors and analyze the implication of phagolysosome formation on the survival of Arcobacter butzleri inside the amoeba. We infer that the attachment of Arcobacter butzleri to the amoeba is a process which involves the participation of mannose-binding proteins and membrane-associated receptors of glucose and galactose present in the amoeba. We also demonstrated an active role of protozoan actin polymerization in the phagocytosis of Arcobacter butzleri and a critical involvement of PI3K and RhoA pathways. Further, we demonstrated that the tyrosine kinase-induced actin polymerization signal is essential in Acanthamoeba-mediated bacterial uptake. Through phagolysosomal formation analysis, we conclude that the survival of Arcobacter butzleri inside the amoeba could be related with the ability to remain inside vacuoles not fused with lysosomes, or with the ability to retard the fusion between these structures. All these results help the understanding of the bacterial uptake mechanisms used by Acanthamoeba castellanii and contribute to evidence of the survival mechanisms of Arcobacter butzleri.

  19. Fibrous Catalyst-Enhanced Acanthamoeba Disinfection by Hydrogen Peroxide.

    Science.gov (United States)

    Kilvington, Simon; Winterton, Lynn

    2017-11-01

    Hydrogen peroxide (H2O2) disinfection systems are contact-lens-patient problem solvers. The current one-step, criterion-standard version has been widely used since the mid-1980s, without any significant improvement. This work identifies a potential next-generation, one-step H2O2, not based on the solution formulation but rather on a case-based peroxide catalyst. One-step H2O2 systems are widely used for contact lens disinfection. However, antimicrobial efficacy can be limited because of the rapid neutralization of the peroxide from the catalytic component of the systems. We studied whether the addition of an iron-containing catalyst bound to a nonfunctional propylene:polyacryonitrile fabric matrix could enhance the antimicrobial efficacy of these one-step H2O2 systems. Bausch + Lomb PeroxiClear and AOSept Plus (both based on 3% H2O2 with a platinum-neutralizing disc) were the test systems. These were tested with and without the presence of the catalyst fabric using Acanthamoeba cysts as the challenge organism. After 6 hours' disinfection, the number of viable cysts was determined. In other studies, the experiments were also conducted with biofilm formed by Stenotrophomonas maltophilia and Elizabethkingia meningoseptica bacteria. Both control systems gave approximately 1-log10 kill of Acanthamoeba cysts compared with 3.0-log10 kill in the presence of the catalyst (P Acanthamoeba cysts and bacterial biofilm. Incorporating the catalyst into the design of these one-step H2O2 disinfection systems could improve the antimicrobial efficacy and provide a greater margin of safety for contact lens users.

  20. The role of topical corticosteroids in the management of Acanthamoeba keratitis.

    Science.gov (United States)

    Park, D H; Palay, D A; Daya, S M; Stulting, R D; Krachmer, J H; Holland, E J

    1997-05-01

    To clarify the role of topical corticosteroids in the management of Acanthamoeba keratitis. The records of 38 patients diagnosed with Acanthamoeba keratitis at three institutions were retrospectively reviewed. After medical therapy alone, patients diagnosed within 1 month of symptom onset had an increased likelihood of being cured (p = 0.02) and attaining visual acuity of 20/60 or better (p Acanthamoeba keratitis. Rather, poor outcome was significantly related to diagnostic delays. Therefore prudent use of corticosteroids in selected patients with severe pain not responsive to analgesics or severe corneal or anterior chamber inflammation appears justified.

  1. The lethal effects of biguanides on cysts and trophozoites of Acanthamoeba castellanii.

    Science.gov (United States)

    Khunkitti, W; Lloyd, D; Furr, J R; Russell, A D

    1996-07-01

    The effects of a range of biocides on trophozoite and encysted forms of Acanthamoeba castellanii were investigated. Viable acanthamoebae were enumerated by a plaque assay technique. The cyst form of Acanthamoeba castellanii was more resistant to all biocides tested than the trophozoite form. Of the biocides tested, chlorhexidine diacetate (CHA) and polyhexamethylene biguanide (PHMB) were the most effective. Their lethal effects were time- and concentration-dependent. CHA was very effective when formulated in 0.1% EDTA combined with Tris buffer pH 7.8 whereas PHMB activity was reduced by 0.1% EDTA. Three per cent dimethylsulphoxide (DMSO) enhanced the activity of CHA but not of PHMB.

  2. Pathogenic and nonpathogenic Acanthamoeba spp. in thermally polluted discharges and surface waters

    Energy Technology Data Exchange (ETDEWEB)

    de Jonckheere, J.F.

    1981-02-01

    During spring and autumn, the total number of amoebae and the number of acanthamoeba species able to grow at 37 degrees C were determined in six thermally polluted factory discharges and the surrounding surface waters. The isolated Acanthamoeba strains were studied for growth in axenic medium, cytopathic effect in Vito cell cultures, and virulence in mice. Although more amoebae were isolated in autumn, the number of Acanthamoeba species was lower than in spring, when the percent of pathogenic strains among the isolates was highest. Higher concentrations of amoebae were found in warm discharges, and more virulent strains occurred in thermal discharges than in surface waters.

  3. Pathogenic and nonpathogenic Acanthamoeba spp. in thermally polluted discharges and surface waters

    International Nuclear Information System (INIS)

    de Jonckheere, J.F.

    1981-01-01

    During spring and autumn, the total number of amoebae and the number of acanthamoeba species able to grow at 37 degrees C were determined in six thermally polluted factory discharges and the surrounding surface waters. The isolated Acanthamoeba strains were studied for growth in axenic medium, cytopathic effect in Vito cell cultures, and virulence in mice. Although more amoebae were isolated in autumn, the number of Acanthamoeba species was lower than in spring, when the percent of pathogenic strains among the isolates was highest. Higher concentrations of amoebae were found in warm discharges, and more virulent strains occurred in thermal discharges than in surface waters

  4. Susceptibility of Acanthamoeba castellanii to contact lens disinfecting solutions.

    Science.gov (United States)

    Zanetti, S; Fiori, P L; Pinna, A; Usai, S; Carta, F; Fadda, G

    1995-01-01

    A corneal isolate of Acanthamoeba castellanii was exposed to commercial contact lens disinfecting solutions containing hydrogen peroxide, benzalkonium chloride, polyaminopropyl biguanide, polyquaternium 1, and chlorhexidine-thimerosal. The minimum trophozoite amebicidal concentration and exposure times required to kill trophozoites and cysts were determined. Solutions containing hydrogen peroxide or chlorhexidine-thimerosal were active against both trophozoites and cysts. The benzalkonium chloride-based solution was effective only against trophozoites. Solutions containing polyaminopropyl biguanide or polyquaternium 1 were completely ineffective. The need for adequate exposure times must be stressed. PMID:7492111

  5. Acanthamoeba keratitis and contact lens wear: static or increasing problem?

    Science.gov (United States)

    Foulks, Gary N

    2007-11-01

    The occurrence of Acanthamoeba keratitis is increasing in the United States because of an expanding population at risk of infection and sporadic outbreaks of infection. Such outbreaks are the result of lapses in contact lens wear and care and of alterations in water quality and water treatment procedures. Although improved techniques in diagnosis are available, better identification of infection alone does not explain an increase in the observed occurrence of the disease. Likewise, there does not appear to be an increase in the virulence or infectivity of the amoebae. Strategies for prevention, including patient education, improved decontaminating agents, maintenance of water treatment standards, and possible immunization of subjects at risk, are needed.

  6. Apoptosis in Acanthamoeba castellanii belonging to the T4 genotype.

    Science.gov (United States)

    Baig, Abdul M; Lalani, Salima; Khan, Naveed A

    2017-07-01

    Here we describe features of apoptosis in unicellular Acanthamoeba castellanii belonging to the T4 genotype. When exposed to apoptosis-inducing compounds such as doxorubicin, A. castellanii trophozoites exhibited cell shrinkage and membrane blebbing as observed microscopically, DNA fragmentation using agarose gel electrophoresis, and phosphatidylserine (PS) externalization using annexin V immunostaining. Overall, these findings suggest the existence of apoptosis in A. castellanii possibly mediated by intrinsic apoptotic cascade. Further research in this field could provide avenues to selectively induce apoptosis in A. castellanii by triggering intrinsic apoptotic cascade. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Acanthamoeba culbertsoni and Naegleria fowleri: occurrence of antibodies in man.

    Science.gov (United States)

    Cerva, L

    1989-01-01

    Serum samples of 1,054 inhabitants of Bohemia (Czechoslovakia) were examined by means of indirect haemagglutination test with antigens from Naegleria fowleri and Acanthamoeba culbertsoni. With N. fowleri antigen the frequency of positive reactions did not exceed 3.5 per cent in lowest serum dilutions only. N. fowleri could not be identified as a possible causative agent in any chronic form of disease in man. Significant accumulation of positive findings with A. culbertsoni antigen was observed in hepatitis A patients and convalescents (52 per cent). The potential interpretations of this phenomenon are discussed.

  8. First time identification of Acanthamoeba genotypes in the cornea samples of wild birds; Is Acanthamoeba keratitis making the predatory birds a target?

    Science.gov (United States)

    Karakavuk, Muhammet; Aykur, Mehmet; Şahar, Esra Atalay; Karakuş, Mehmet; Aldemir, Duygu; Döndüren, Ömer; Özdemir, Hüseyin Gökhan; Can, Hüseyin; Gürüz, Adnan Yüksel; Dağcı, Hande; Döşkaya, Mert

    2017-12-01

    Acanthamoeba is a free-living amoeba which can be isolated from environment and among others well known as an opportunist protozoan parasite causing infections in humans and animals. Eyes are extremely important for the wild birds and losing sight ability due to Acanthamoeba can be dangerous. The studies on Acanthamoeba infection in wild birds is very few in world and Turkey therefore we aimed to screen deceased wild birds found in İzmir and Manisa provinces located in western Turkey using PCR and non-nutrition agar (NNA) plate method. Cornea samples were obtained from 18 deceased wild birds. During the external examination, signs of keratitis were observed in two Eurasian sparrowhawks (Accipiter nisus). All of the corneal samples were analyzed by two PCR methods and NNA plate. According to results, the Acanthamoeba positivity in corneal samples was 16.6% and 5.5% by PCR and plate method, respectively. According to sequencing data, two of isolates belonged to genotype T5 and one was genotype T4. In conclusion, Acanthamoeba infection was detected in wild bird cornea samples with/without keratitis for the first time in the world. The result of this study also show that Acanthamoeba can be a cause of keratitis in wild birds of Turkey and thus these predator birds can be a target of other wild animals due to loss of sight ability. In terms of public health, these results show the importance of wild birds as a source of Acanthamoeba infection in nature. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. La peroxidación lipídica en la etiopatogenia de la enfermedad periodontal inflamatoria

    Directory of Open Access Journals (Sweden)

    Bárbara E García Triana

    1998-04-01

    Full Text Available Las especies reactivas del oxígeno están implicadas en la etiopatogenia de la inflamación. Durante la activación de los leucocitos, se liberan grandes cantidades de estas especies, cuya función es la eliminación de los agentes patógenos. Si las defensas antioxidantes de los tejidos no funcionan eficientemente, son inducidas reacciones radicálicas que afectan a las biomoléculas. El ataque a los lípidos de la membrana celular provoca su peroxidación, con la consiguiente formación de nuevas especies radicálicas y metabolitos tóxicos. La presencia de un fuerte infiltrado inflamatorio en los tejidos periodontales, durante la enfermedad periodontal inflamatoria, ha sugerido la posible participación de las especies reactivas del oxígeno en la etiopatogenia de esta enfermedad. Se supone que el ataque de estas sustancias a los tejidos periodontales con deficiente defensa antioxidante, provoca la aparición de la peroxidación lipídica, que puede conducir a la lisis celular y la activación de proteasas.The reative oxygen species are involved in the pathogenesis of inflammation. Leukocyte activation released a great amount of these species the function of which is to eliminate pathogen agents. If antioxidant tissue defenses do not act properly, then radical reactions affecting biomolecules are induced. The attack on cell membrane lipids caused their peroxidation followed by the formation of new radical species and toxic metabolites. The existence of a strong inflammatory infiltrate in periodontal tissues in the course of the periodontal disease suggest the possible involvement of reactive oxygen species in the pathogenesis of this disease. It is supposed that the attack of these substances on the poorly antioxidant defended periodontal tissues makes the lipid peroxidation take place, which may lead to cellular lysis and proteases activation.

  10. Biologic therapies for chronic inflammatory bowel disease Tratamientos biológicos en la enfermedad inflamatoria crónica intestinal

    Directory of Open Access Journals (Sweden)

    M. P. Martínez-Montiel

    2006-04-01

    Full Text Available Crohn's disease (CD and ulcerative colitis (UC make up the so-called chronic inflammatory bowel disease (IBD. Advances in the understanding of IBD pathophysiologic mechanisms in the last few years have allowed the development of novel therapies such as biologic therapies, which at least theoretically represent a more specific management of this disease with fewer side effects. Currently, the only effective and widely accepted biologic therapy for the treatment of intraluminal, fistulizing CD, both for remission induction and maintenance, is infliximab. The role of other monoclonal antibodies such as adalimumab is not clearly established. It could be deemed an alternative for patients with allergic reactions to infliximab, and for those with lost response because of anti-infliximab antibody development. However, relevant issues such as dosage and administration regimen remain to be established. Anti-integrin α4 therapies, despite encouraging results in phase-3 studies, are still unavailable, as their marketing authorization was held back in view of a number of reports regarding progressive multifocal leukoencephalopathy cases. Immunostimulating therapy may be highly relevant in the near future, as it represents a novel strategy against disease with the inclusion of granulocyte-monocyte colony-stimulating factors. Regarding ulcerative colitis, results from the ACT-1 and ACT-2 studies showed that infliximab is also useful for the management of serious UC flare-ups not responding to standard treatment, which will lead to a revision of therapeutic algorithms, where this drug should be given preference before intravenous cyclosporine. In the next few years, the role of anti-CD3 drugs (vilisilizumab, T-cell inhibiting therapies, and epithelial repair and healing stimulating factors will be established.La enfermedad de Crohn (EC y la colitis ulcerosa (CU constituyen la denominada enfermedad inflamatoria crónica intestinal (EII. Los avances producidos

  11. Effect of patient wear and extent of protein deposition on adsorption of Acanthamoeba to five types of hydrogel contact lenses.

    Science.gov (United States)

    Simmons, P A; Tomlinson, A; Connor, R; Hay, J; Seal, D V

    1996-06-01

    Attachment of Acanthamoeba species to hydrogel contact lenses is a possible route of infection in Acanthamoeba keratitis. In this study, Acanthamoeba adsorption was compared with extent of lens deposition in worn lenses of different hydrogel polymers. After wear, lenses (80 lenses of 5 different types) were analyzed for total protein, surface area of deposition, and Acanthamoeba castellani trophozoite and cyst adsorption. Adsorption of Acanthamoeba trophozoites to worn lenses was greater than adsorption to unworn lenses for four of the five lens polymers (p 0.05). Adsorption was affected by both the water content and ionicity of the lens polymer. These results show that adsorption of Acanthamoeba to worn hydrogel contact lenses is greater than or equal to adsorption to unworn lenses.

  12. Surveillance and Molecular Identification of Acanthamoeba and Naegleria Species in Two Swimming Pools in Alexandria University, Egypt

    Science.gov (United States)

    AL-HERRAWY, Ahmad Z.; KHALIL, Mahmoud I.; EL-SHERIF, Soheir S.; OMAR, Fatima A. E.; LOTFY, Wael M.

    2017-01-01

    Background: Swimming in contaminated water was reported to be associated with Acanthamoeba and N. fowleri human infections. The present study was carried out with the aim of isolation and identification of the different species of Acanthamoeba and Naegleria from two swimming pools in Alexandria University. Methods: Samples were collected from the swimming pools of Alexandria University Stadium and Faculty of Agriculture-Alexandria University during the period from May 2012 to April 2013. Results: Free-living amoebae were prevalent in the collected samples. Molecular characterization confirmed the identity of ten Acanthamoeba isolates and seven Naegleria isolates. Acanthamoeba T3, T4, T5, T11 and T15 genotypes were identified. Acanthamoeba T4 was the most prevalent genotype. Conclusion: The relatively high prevalence of Acanthamoeba, especially genotype T4, indicates the presence of a health hazard to swimmers particularly those wearing contact lenses. Naegleria fowleri was not found during the present study. PMID:28761479

  13. Surveillance and Molecular Identification of Acanthamoeba and Naegleria Species in Two Swimming Pools in Alexandria University, Egypt

    Directory of Open Access Journals (Sweden)

    Ahmad Z. AL-HERRAWY

    2017-06-01

    Full Text Available Background: Swimming in contaminated water was reported to be associated with Acanthamoeba and N. fowleri human infections. The present study was carried out with the aim of isolation and identification of the different species of Acanthamoeba and Naegleria from two swimming pools in Alexandria University. Methods: Samples were collected from the swimming pools of Alexandria University Stadium and Faculty of Agriculture-Alexandria University during the period from May 2012 to April 2013.Results: Free-living amoebae were prevalent in the collected samples. Molecular characterization confirmed the identity of ten Acanthamoeba isolates and seven Naegleria isolates. Acanthamoeba T3, T4, T5, T11 and T15 genotypes were identified. Acanthamoeba T4 was the most prevalent genotype.Conclusion: The relatively high prevalence of Acanthamoeba, especially genotype T4, indicates the presence of a health hazard to swimmers particularly those wearing contact lenses. Naegleria fowleri was not found during the present study. 

  14. Methanolic extract of Peganum harmala exhibit potent activity against Acanthamoeba castellanii cysts and its encystment in vitro.

    Science.gov (United States)

    Shohaib, Hafiz Muhammad; Nawaz, Salik; Matin, Abdul

    2016-11-01

    Acanthamoeba castellanii is member of free living amoeba that may cause painful sight-threatening keratitis and life threatening encephalitis which involves central nervous system. Treatments for both infections are problematic because of the amoebic cysts resistance to therapeutic agents. Here we evaluated in vitro strength of methanolic seed extract of Peganum harmala on Acanthamoeba cysts and its encystment mechanism. Our results revealed seed extracts (1 to 30mg/ml) exhibited amoebicidal effects against Acanthamoeba cysts. Furthermore Acanthamoeba encystment was also inhibited in concentration dependent manner with maximum inhibition at 2µg/ml after 48h incubation. In conclusion, we demonstrated for the first time that methanolic extracts exhibit remarkable inhibition of Acanthamoeba cysts and encystment in vitro which could serve a potential new natural agent against Acanthamoeba.

  15. Amoebicidal or amoebostatic influence of disinfectants used in health facilities and laboratories on corneal strains of Acanthamoeba

    Science.gov (United States)

    Baltaza, Wanda; Padzik, Marcin; Szaflik, Jacek P; Dybicz, Monika; Hendiger, Edyta; Chomicz, Lidia

    Different Acanthamoeba species are amphizoic organisms distributed in wide range of habitats in natural and man-made environments; they are also detected on surfaces of equipment and accessories in health facilities. Some strains of the amoebae are causative agents of the vision-threatening human disease Acanthamoeba keratitis, mainly reported in contact lens wearers. An exceptional high resistance of Acanthamoeba trophozoites and particularly cysts to chemicals, disinfectants and drugs is believed as influencing difficulty resulting in unsuccessful therapeutic management. As Acanthamoeba keratitis is the serious medical problem worldwide, different chemicals with possible activity against environmental and clinical Acanthamoeba strains are tested. In our study, selected disinfectants used in health care settings and laboratories were tested and their efficacy against the corneal strains Acanthamoeba castellanii and A. polyphaga , and environmental A. castellanii Neff strain was assessed. Comparative assessment of results of the assays show that, apart from amoebistatic effects, the disinfectants indicated expected cysticidal efficacy.

  16. MODULACION DE LA EXPRESION DE INTERLEUCINA-6 EN RESPUESTA AL MOVIMIENTO DENTARIO INDUCIDO POR EL ARCO .014 DE NiTi EN PACIENTES CON MALOCLUSION

    OpenAIRE

    Leon Romero, Luis Cenen

    2012-01-01

    El apiñamiento dentario es una anomalía dentomaxilar altamente frecuente, asociado con otros signos de maloclusión. El recurso clínico-ortodóntico para corregirlo es el movimiento dentario inducido por fuerzas mecánicas en los tejidos periodontales que bajo la fuerza mantenida, sufren una serie de modificaciones reguladas por procesos histológicos y fisiológicos que pueden dar como respuesta reacciones inflamatorias. La biología del movimiento dentario comprende el estudio de l...

  17. Acanthamoeba keratitis with granulomatous reaction involving the stroma and anterior chamber.

    Science.gov (United States)

    Mietz, H; Font, R L

    1997-02-01

    Most cases of granulomatous reaction to Descemet membrane are caused by disciform herpes simplex and mycotic keratitis. To our knowledge, a clinicopathologic report of Acanthamoeba species infection has not been documented. We used standard histopathologic techniques, including light microscopy with special stains and indirect immunofluorescence. A granulomatous reaction with many multinucleated giant cells, some of which engulfed cysts of Acanthamoeba species, was present in the posterior corneal stroma and anterior chamber along the plane of Descemet membrane. A severe, acute, suppurative inflammatory response and areas of stromal necrosis also were present. The diagnosis of Acanthamoeba castellanii was confirmed by immunofluorescent studies. A granulomatous reaction to Descemet membrane and/or the corneal stroma may represent a specific tissue response to various infectious agents. Keratitis caused by Acanthamoeba species may be added to herpes simplex stromal keratitis and mycotic keratitis as a causative organism capable of producing a granulomatous reaction involving the stroma and anterior chamber.

  18. Acanthamoeba and Stenotrophomonas maltophilia keratitis with fungal keratitis in the contralateral eye

    Directory of Open Access Journals (Sweden)

    Thomas F Mauger

    2010-10-01

    Full Text Available Thomas F Mauger, Rebecca Ann Kuennen, Reynell Harder Smith, William SawyerDepartment of Ophthalmology, The Ohio State University, Columbus, OH, USAPurpose: The purpose of this study is to describe the diagnosis, course, and outcome of a case of Acanthamoeba and Stenotrophomonas keratitis with a fungal keratitis in the contralateral eye.Methods: A case of Acanthamoeba and Stenotrophomonas keratitis was diagnosed with confocal microscopy and cultures with confocal diagnosis of fungal keratitis in the fellow eye.Results: During the initial treatment of the Acanthamoeba and Stenotrophomonas keratitis, the contralateral eye developed a keratitis that demonstrated hyphae in the corneal stroma with confocal microscopy consistent with fungal keratitis.Conclusions: Bilateral chronic keratitis cannot be assumed to be caused by the same organism and independent cultures, and confocal microscopy needs to be performed to direct appropriate therapy.Keywords: Acanthamoeba, Stenotrophomonas, confocal, fungus, keratitis

  19. Acanthamoeba keratitis in a non-contact lens wearer with human immunodeficiency virus

    DEFF Research Database (Denmark)

    Hansen, Birgitte Rønde; Kronborg, Gitte

    2003-01-01

    Acanthamoeba keratitis is potentially blinding and often associated with contact lens wearing. A human immunodeficiency virus (HIV)-positive patient, a non-contact lens wearer, presented with keratitis. She experienced a protracted course of disease, characterized by exacerbations and remissions......, and was treated with various topical antibiotics and steroids. 13 months after symptom onset the eye was removed owing to serious scarring of cornea and unbearable pain. Microbiological and histopathological examination of the cornea showed Acanthamoeba. In non-contact lens wearers suffering from Acanthamoeba...... keratitis the diagnosis is delayed, pathognomonic features are often not seen and visual outcome is usually poor. There is no known relation between HIV infection and Acanthamoeba keratitis....

  20. Azole Antifungal Agents To Treat the Human Pathogens Acanthamoeba castellanii and Acanthamoeba polyphaga through Inhibition of Sterol 14α-Demethylase (CYP51).

    Science.gov (United States)

    Lamb, David C; Warrilow, Andrew G S; Rolley, Nicola J; Parker, Josie E; Nes, W David; Smith, Stephen N; Kelly, Diane E; Kelly, Steven L

    2015-08-01

    In this study, we investigate the amebicidal activities of the pharmaceutical triazole CYP51 inhibitors fluconazole, itraconazole, and voriconazole against Acanthamoeba castellanii and Acanthamoeba polyphaga and assess their potential as therapeutic agents against Acanthamoeba infections in humans. Amebicidal activities of the triazoles were assessed by in vitro minimum inhibition concentration (MIC) determinations using trophozoites of A. castellanii and A. polyphaga. In addition, triazole effectiveness was assessed by ligand binding studies and inhibition of CYP51 activity of purified A. castellanii CYP51 (AcCYP51) that was heterologously expressed in Escherichia coli. Itraconazole and voriconazole bound tightly to AcCYP51 (dissociation constant [Kd] of 10 and 13 nM), whereas fluconazole bound weakly (Kd of 2,137 nM). Both itraconazole and voriconazole were confirmed to be strong inhibitors of AcCYP51 activity (50% inhibitory concentrations [IC50] of 0.23 and 0.39 μM), whereas inhibition by fluconazole was weak (IC50, 30 μM). However, itraconazole was 8- to 16-fold less effective (MIC, 16 mg/liter) at inhibiting A. polyphaga and A. castellanii cell proliferation than voriconazole (MIC, 1 to 2 mg/liter), while fluconazole did not inhibit Acanthamoeba cell division (MIC, >64 mg/liter) in vitro. Voriconazole was an effective inhibitor of trophozoite proliferation for A. castellanii and A. polyphaga; therefore, it should be evaluated in trials versus itraconazole for controlling Acanthamoeba infections. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  1. Possible environmental sources of Acanthamoeba spp in contact lens wearers.

    Science.gov (United States)

    Seal, D; Stapleton, F; Dart, J

    1992-01-01

    The water supply and dust samples from the home environment (bathrooms and kitchens) of 50 wearers of contact lenses (CLs) were cultured for the presence of free-living amoebae. CL cases, solutions, and water taps were cultured for bacteria, which amoebae require for growth. Acanthamoeba spp were isolated from water drawn from six bathroom cold water taps (tank supplied), five in the presence of limescale, and from one kitchen cold water tap (mains supplied). There was an association between the presence of limescale in water and direct culture for free-living amoebae, suggesting that scale provides a favourable microenvironment for amoebae. Acanthamoebae were also found in dust from around one washbasin. Nineteen of 50 CL cases, 12/122 CL care rinsing solutions, and 59/100 cold water taps yielded Gram negative bacteria which could be ingested by amoebae. It is concluded from this study that CLs should not be washed in first-drawn tank-fed cold water, especially if limescale is present, and that soft CLs should be rinsed in manufactured single-use, sterile solutions. Rigid CL and CL cases should only be washed with boiled tap water (preferably hot), or single-use sterile solutions, and stored dry to prevent multiplication of amoebae and Gram negative bacteria. PMID:1627513

  2. Acanthamoeba keratitis in patients wearing scleral contact lenses.

    Science.gov (United States)

    Sticca, Matheus Porto; Carrijo-Carvalho, Linda C; Silva, Isa M B; Vieira, Luiz A; Souza, Luciene B; Junior, Rubens Belfort; Carvalho, Fábio Ramos S; Freitas, Denise

    2017-12-05

    To report a series of cases of Acanthamoeba keratitis (AK) in scleral lens wearers with keratoconus to determine whether this type of contact lens presents a greater risk for development of infection. This study reports three patients who wore scleral contact lenses to correct keratoconus and developed AK. The diagnoses of AK were established based on cultures of the cornea, scleral contact lenses, and contact lens paraphernalia. This study investigated the risk factors for infections. The possible risks for AK in scleral contact lens wearers are hypoxic changes in the corneal epithelium because of the large diameter and minimal tear exchange, use of large amounts of saline solution necessary for scleral lens fitting, storing the scleral lens overnight in saline solution rather than contact lens multipurpose solutions, not rubbing the contact lens during cleaning, and the space between the cornea and the back surface of the scleral lens that might serve as a fluid reservoir and environment for Acanthamoeba multiplication. Two patients responded well to medical treatment of AK; one is still being treated. The recommendations for use and care of scleral contact lenses should be emphasized, especially regarding use of sterile saline (preferably single use), attention to rubbing the lens during cleaning, cleaning of the plunger, and overnight storage in fresh contact lens multipurpose solutions without topping off the lens solution in the case. Copyright © 2017. Published by Elsevier Ltd.

  3. Adhesion forces and mechanics in mannose-mediated acanthamoeba interactions.

    Directory of Open Access Journals (Sweden)

    Steven Huth

    Full Text Available The human pathogenic amoeba Acanthamoeba castellanii (A. castellanii causes severe diseases, including acanthamoeba keratitis and encephalitis. Pathogenicity arises from the killing of target-cells by an extracellular killing mechanism, where the crucial first step is the formation of a close contact between A. castellanii and the target-cell. This process is mediated by the glycocalix of the target-cell and mannose has been identified as key mediator. The aim of the present study was to carry out a detailed biophysical investigation of mannose-mediated adhesion of A. castellanii using force spectroscopy on single trophozoites. In detail, we studied the interaction of a mannose-coated cantilever with an A. castellanii trophozoite, as mannose is the decisive part of the cellular glycocalix in mediating pathogenicity. We observed a clear increase of the force to initiate cantilever detachment from the trophozoite with increasing contact time. This increase is also associated with an increase in the work of detachment. Furthermore, we also analyzed single rupture events during the detachment process and found that single rupture processes are associated with membrane tether formation, suggesting that the cytoskeleton is not involved in mannose binding events during the first few seconds of contact. Our study provides an experimental and conceptual basis for measuring interactions between pathogens and target-cells at different levels of complexity and as a function of interaction time, thus leading to new insights into the biophysical mechanisms of parasite pathogenicity.

  4. Acanthamoeba keratitis: study of the 5-year incidence in Israel.

    Science.gov (United States)

    Graffi, Shmuel; Peretz, Avi; Jabaly, Haneen; Koiefman, Anna; Naftali, Modi

    2013-11-01

    Acanthamoeba keratitis (AK) is not a notifiable disease in Israel, so there are no accurate incidence rates for this condition in Israel. The aim of this study was to estimate the incidence of AK in Israel for the years 2008-2012. We distributed a survey questionnaire to laboratory managers in Israel. The laboratories were affiliated to medical institutes that either provided ophthalmology services or served community ophthalmology clinics. Our questionnaire requested survey respondents to provide information regarding the methods used to diagnose AK, and the number of positive and negative cultures for Acanthamoebae species performed for each of the years from 2008 to 2012. Six laboratories used non-nutrient agar with Escherichia coli as the culture medium, one used calcofluor-white staining with fluorescent microscopy, and two used PCR for diagnosing AK. Twenty-three AK cases were identified, to give an estimated incidence of 1/1 668 552. AK is mostly attributable to the use of contact lenses. As contact lenses are popular in Israel, we expected a higher incidence rate. A lower than expected incidence rate may indicate insufficient awareness of AK in Israel.

  5. Acanthamoeba and Fusarium interactions: A possible problem in keratitis.

    Science.gov (United States)

    Nunes, Thais Esther Teixeira; Brazil, Nathalya Tesch; Fuentefria, Alexandre Meneghello; Rott, Marilise Brittes

    2016-05-01

    The incidence of Acanthamoeba and Fusarium species has increased in contact lens-related infectious keratitis. They share several environments and cases of co-infection have been reported. The interaction between the amoebae and other microorganisms may result in significant changes for both, like increased virulence in mammalian hosts. In this study, we evaluated the interaction of three Acanthamoeba castellanii strains with Fusarium conidia and the possible implications on keratitis. F. conidia were internalized by A. castellanii strains and were able to germinate inside the amoebae. The co-culture with the live amoebae, as well as the amoebal culture supernatant and lysate, increased the fungal growth significantly. Moreover, live F. solani and its culture supernatant enhanced the survival of amoebae, but in a different way in each amoebal strain. The encystment of the A. castellanii strain re-isolated from rat lung was increased by the fungus. These results show that A. castellanii and F. solani interaction may have an important influence on survival of both, and specially indicate a possible effect on virulence characteristics of these microorganisms. These data suggest that the A. castellanii-F. solani interaction may cause severe impacts on keratitis. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Ammoides pusilla (Apiaceae) essential oil: Activity against Acanthamoeba castellanii Neff.

    Science.gov (United States)

    Souhaiel, Najet; Sifaoui, Ines; Ben Hassine, Dorsaf; Bleton, Jean; Bonose, Myriam; Moussa, Fathi; Piñero, José E; Lorenzo-Morales, Jacob; Abderrabba, Manef

    2017-12-01

    Acanthamoeba is a free-living amoeba genus that causes several diseases namely, amoebic keratitis which is a painful sight threatening eyes disease. Its treatment is difficult and the exploration for new drugs is very important. The main objective of the present study was to evaluate the chemical composition of the Essential Oils (EO) obtained from leaves and flowers and aerial parts of Ammoides pusilla by an alternative method "Hydrodistillation''. Identification and quantification were realized by Gas Chromatography-Mass Spectrometry (GC-MS) and Gas Chromatography with Flame Ionization Detection (GC-FID). The main components of leaves and flowers and aerials parts were thymol (39.6% and 33.05%), γ-terpinene (28.97% and 28.19%), p-cymene (13.69% and 15.31%) and thymol methyl ether (7.33% and 8.91%), respectively. The antiparasitic activity of the EO was evaluated against Acanthamoeba castellanii Neff by the Alamar Blue ® assay. Results showed that Ammoides pusilla amoebicidal activity from leaves and flowers essential oil (IC 50  = 65.32 ± 5.43 μg/mL) was more important than those of aerial parts EO (IC 50  = 97.18 ± 1.43 μg/ml). Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Effects of mannose on pathogenesis of Acanthamoeba castellanii.

    Science.gov (United States)

    Yoo, Kyung-Tae; Jung, Suk-Yul

    2012-12-01

    Acanthamoeba spp. are single-celled protozoan organisms that are widely distributed in the environment. In this study, to understand functional roles of a mannose-binding protein (MBP), Acanthamoeba castellanii was treated with methyl-alpha-D-mannopyranoside (mannose), and adhesion and cytotoxicity of the amoeba were analyzed. In addition, to understand the association of MBP for amoeba phagocytosis, phagocytosis assay was analyzed using non-pathogenic bacterium, Escherichia coli K12. Amoebae treated with mannose for 20 cycles exhibited larger vacuoles occupying the most area of the amoebic cytoplasm in comparison with the control group amoebae and glucose-treated amoebae. Mannose-selected amoebae exhibited lower levels of binding to Chinese hamster ovary (CHO) cells. Exogenous mannose inhibited >50% inhibition of amoebae (control group) binding to CHO cells. Moreover, exogenous mannose inhibited amoebae (i.e., man-treated) binding to CHO cells by castellanii trophozoites should be severely damaged and do not well interact with a target cell via a lectin of MBP.

  8. Adhesion forces and mechanics in mannose-mediated acanthamoeba interactions

    Science.gov (United States)

    Leippe, Matthias

    2017-01-01

    The human pathogenic amoeba Acanthamoeba castellanii (A. castellanii) causes severe diseases, including acanthamoeba keratitis and encephalitis. Pathogenicity arises from the killing of target-cells by an extracellular killing mechanism, where the crucial first step is the formation of a close contact between A. castellanii and the target-cell. This process is mediated by the glycocalix of the target-cell and mannose has been identified as key mediator. The aim of the present study was to carry out a detailed biophysical investigation of mannose-mediated adhesion of A. castellanii using force spectroscopy on single trophozoites. In detail, we studied the interaction of a mannose-coated cantilever with an A. castellanii trophozoite, as mannose is the decisive part of the cellular glycocalix in mediating pathogenicity. We observed a clear increase of the force to initiate cantilever detachment from the trophozoite with increasing contact time. This increase is also associated with an increase in the work of detachment. Furthermore, we also analyzed single rupture events during the detachment process and found that single rupture processes are associated with membrane tether formation, suggesting that the cytoskeleton is not involved in mannose binding events during the first few seconds of contact. Our study provides an experimental and conceptual basis for measuring interactions between pathogens and target-cells at different levels of complexity and as a function of interaction time, thus leading to new insights into the biophysical mechanisms of parasite pathogenicity. PMID:28472161

  9. Inhibition of Acanthamoeba species by Pseudomonas aeruginosa: rationale for their selective exclusion in corneal ulcers and contact lens care systems.

    Science.gov (United States)

    Qureshi, M N; Perez, A A; Madayag, R M; Bottone, E J

    1993-01-01

    Cocultivation of Acanthamoeba castellanii and Acanthamoeba polyphaga with live Pseudomonas aeruginosa and with broth filtrates of P. aeruginosa proved equally lethal to the Acanthamoeba spp. The P. aeruginosa-induced amebicidal activity is apparently toxin mediated and has two operative modes: it can function through binding of P. aeruginosa to the ameba membrane and in the presence of one or more P. aeruginosa exoproducts. Images PMID:8349772

  10. Identification of 18S ribosomal DNA genotype of Acanthamoeba from hot spring recreation areas in the central range, Taiwan

    Science.gov (United States)

    Hsu, Bing-Mu; Ma, Po-Hua; Liou, Tai-Sheng; Chen, Jung-Sheng; Shih, Feng-Cheng

    2009-04-01

    SummaryAcanthamoeba is a free-living amoebae ubiquitous to aquatic environments. Within the genus a few species are recognized as opportunistic potential human pathogens, which cause granulomatous amoebic encephalitis (GAE) and keratitis. Infections of keratitis are frequently reported through wearing lens while swimming in the non-disinfected aquatic environment. Contaminations in hot tubs, spas and public baths are also possible. As a result, in this study, we identified Acanthamoeba based on the PCR amplification with a genus-specific primer pair and investigated the distribution of Acanthamoeba at five hot spring recreation areas in central range, Taiwan. We gathered data on factors potentially associated with the pathogen's distribution, including various sampling sites, aquatic environment, physical and microbiological water quality parameters. Spring water was collected from 55 sites and Acanthamoeba was detected in 9 (16.4%). The most frequently detected was Acanthamoeba griffini, followed by Acanthamoeba jacobsi. Legionella were detected in 18 (32.7%) of the sites sampled in this study. The species of Legionella identified included Legionella pneumophila serotype 6, serotype 1, and Legionella erythra. Overall, 9.1% of the samples contained both Acanthamoeba and Legionella. The prevalence of Acanthamoeba was contrary to the levels of microbiological indicators recommended by Taiwan CDC, and no significant differences (Mann-Whitney U test, P Acanthamoeba and water quality parameters. Results of this survey confirm the existence of Acanthamoeba in Taiwan spring recreation areas. Acanthamoeba, the organism responsible for the majority of Acanthamoeba keratitis and can serve as vehicles for facultative pathogens, should be considered a potential threat for health associated with human activities in spring recreation areas of Taiwan.

  11. In the case of transmission of Mycobacterium ulcerans in buruli ulcer disease Acanthamoeba species stand accused.

    Science.gov (United States)

    Wilson, M D; Boakye, D A; Mosi, L; Asiedu, K

    2011-03-01

    Buruli ulcer disease caused by Mycobacterium ulcerans results in extensive destruction of skin and soft tissue and long-term functional disabilities that ultimately require surgery and rehabilitation. The disease is associated with aquatic and swampy environments with the mycobacterium occurring in biofilms, soil, aquatic insects, fish and wildlife however, the mode of transmission to humans remains an enigma. Current transmission ideas including bites from predatory water bugs and mosquitoes, do not explain satisfactorily the spasmodic disease distribution in human populations. Here we argue that Acanthamoeba species are the natural hosts of M. ulcerans and are mainly responsible for disease transmission because; (i) Acanthamoebae are known natural hosts of several microbial pathogens including M. marinum, M. avium and Legionella pneumophila, (ii) culture of slow-to-grow microbial pathogens hosted in nature by Acanthamoeba spp is enhanced when the media is seeded with the protozoa, (iii) acanthamoebae and M. ulcerans share similar bio-ecological and epidemiological settings, (iv) documented evidence that prior growth of L. pneumophila and M. avium in acanthamoebae influences entry mechanisms, intracellular growth and virulence in human monocytes, (v) Acanthamoeba spp also infect humans and cause diseases via routes of openings including broken skin and sites of trauma similar to M. ulcerans and (vi) M. ulcerans is rather a fastidious intracellular organism as recent analysis of the genome indicate. We argue further that temperature plays a significant role in transmission determining the fate of either the intracellular microbe or the host cells. Also, Acanthamoeba-pathogen association has a long evolutionary history because the same set of bacterial genes and gene products e.g. in L. pneumophila are required for survival in both mammalian and protozoan host cells. We suggest that the involvement of Acanthamoeba in the transmission of M. ulcerans to humans better

  12. Acanthamoeba keratitis in a non-contact lens wearer with human immunodeficiency virus

    DEFF Research Database (Denmark)

    Hansen, Birgitte Rønde; Kronborg, Gitte

    2003-01-01

    Acanthamoeba keratitis is potentially blinding and often associated with contact lens wearing. A human immunodeficiency virus (HIV)-positive patient, a non-contact lens wearer, presented with keratitis. She experienced a protracted course of disease, characterized by exacerbations and remissions...... keratitis the diagnosis is delayed, pathognomonic features are often not seen and visual outcome is usually poor. There is no known relation between HIV infection and Acanthamoeba keratitis....

  13. Genetic analyses of Acanthamoeba isolates from contact lens storage cases of students in Seoul, Korea

    OpenAIRE

    Yu, Hak-Sun; Choi, Kyung-Hee; Kim, Hyo-Kyung; Kong, Hyun-Hee; Chung, Dong-Il

    2001-01-01

    We conducted both the small subunit ribosomal DNA (SSU rDNA) polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and mitochondrial (mt) DNA RFLP analyses for a genetic characterization of Acanthamoeba isolates from contact lens storage cases of students in Seoul, Korea. Twenty-three strains of Acanthamoeba from the American Type Culture Collection and twelve clinical isolates from Korean patients were used as reference strains. Thirty-nine isolates from contact lens ...

  14. Evaluation of Anti-amoebic Activity of Peganum harmala Ethanolic Extract on Acanthamoeba In vitro

    Directory of Open Access Journals (Sweden)

    Tooran Nayeri Chegeni

    2018-03-01

    Full Text Available Abstract Background: Acanthamoeba is an opportunistic protozoan pathogen that is known to infect the cornea to produce eye keratitis and the central nervous system to produce lethal granulomatous encephalitis. The overall aim of the present study was to determine the anti-amoebic potential of natural compound Peganum harmala against the trophozoites and cysts of Acanthamoeba in vitro. Materials and Methods: In this experimental study, a clinical isolate of Acanthamoeba was cultured and genotyped. The ethanolic extract of Peganum harmala was prepared. The trophozoites and cysts were collected by washing in page's saline. Various concentrations (1.25, 2.5, 5, and 10 mg/ml of the ethanolic extract and polyhexanide 0.02% drop as positive control were tested at three different times (24, 48 and 72 h on trophozoites and cysts of Acanthamoeba in vitro. The viability of trophozoites or cysts was tested by eozin method, MTT, and flowcytometry analysis. Results: The results revealed that alcoholic extract had remarkable inhibitory effect on the proliferation of Acanthamoeba cysts as compared to non-treated control, and the inhibition was time and dose dependent. In the presence of 10 mg/ml ethanolic extract in medium culture after 72 h, no viable trophozoites were determined and 21.10% cysts of Acanthamoeba were viable. Percentage of trophozoites and cysts viability after adding polyhexanide 0.02% drop in medium culture after 72 hours was 0% and 23.71%, respectively. Conclusion: Ethanolic extracts of Peganum harmala could be considered a new natural compound against the Acanthamoeba trophozoites and cysts. Further works are required to evaluate the exact effect of this extract on Acanthamoeba agents in animal models.

  15. Reevaluation of an Acanthamoeba Molecular Diagnostic Algorithm following an Atypical Case of Amoebic Keratitis.

    Science.gov (United States)

    Lau, Rachel; Cunanan, Marlou; Jackson, Jonathan; Ali, Ibne Karim M; Chong-Kit, Ann; Gasgas, Jason; Tian, Jinfang; Ralevski, Filip; Boggild, Andrea K

    2015-10-01

    Amoebic keratitis (AK) is a potentially blinding infection, the prompt diagnosis of which is essential for limiting ocular morbidity. We undertook a quality improvement initiative with respect to the molecular detection of acanthamoebae in our laboratory because of an unusual case of discordance. Nine ATCC strains of Acanthamoeba and 40 delinked, biobanked, surplus corneal scraping specimens were analyzed for the presence of acanthamoebae with four separate real-time PCR assays. The assay used by the Free-Living and Intestinal Amebas Laboratory of the CDC was considered the reference standard, and the performance characteristics of each individual assay and pairs of assays were calculated. Outcome measures were sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). Of 49 included specimens, 14 (28.6%) were positive by the gold standard assay, and 35 (71.4%) were negative. The sensitivities of the individual assays ranged from 64.3% to 92.9%, compared to the gold standard, while the specificities ranged from 88.6% to 91.4%. The PPVs and NPVs ranged from 69.2% to 78.6% and from 86.1% to 96.9%, respectively. Combinations of assay pairs led to improved performance, with sensitivities ranging from 92.9% to 100% and specificities ranging from 97.1% to 100%. ATCC and clinical strains of Acanthamoeba that failed to be detected by certain individual assays included Acanthamoeba castellanii, Acanthamoeba culbertsoni, and Acanthamoeba lenticulata. For three clinical specimens, false negativity of the gold standard assay could not be excluded. Molecular diagnostic approaches, especially combinations of highly sensitive and specific assays, offer a reasonably performing, operator-independent, rapid strategy for the detection of acanthamoebae in clinical specimens and are likely to be more practical than either culture or direct microscopic detection. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  16. First report of an Acanthamoeba genotype T13 isolate as etiological agent of a keratitis in humans.

    Science.gov (United States)

    Grün, Anna-Lena; Stemplewitz, Birthe; Scheid, Patrick

    2014-06-01

    Several strains of free-living amoebae (FLA) belonging to the genus Acanthamoeba are able to cause a painful sight-threatening disease of the cornea designated as Acanthamoeba keratitis (AK). In this case report, a 22-year-old woman, wearer of soft contact lenses, was treated after the initial examination, and follow-up laboratory results led to the diagnosis of Acanthamoeba keratitis. The patient recovered under the targeted therapy, demonstrating that the acanthamoebae were the etiological agents of the keratitis in this case. The acanthamoebae belonged morphologically to group II. Genotyping of the causative Acanthamoeba strain based on sequences of the PCR amplimer ASA.S1 amplified from 18S ribosomal DNA by using the genus-specific primers JDP1 and JDP2 followed. The phylogenetic comparison of ASA.S1 confirmed that the isolated Acanthamoeba strain is closely related to genotype T13 supported by pairwise sequence identities of 97.1-98.0% and bootstrap support of 980 replicates with reference sequences of genotype T13. These results regarding the Acanthamoeba keratitis-causing isolate KaBo expands the number of known pathogenic genotypes to 12. To our knowledge, this is the first report of a T13 Acanthamoeba genotype being associated with keratitis in humans.

  17. Detection and molecular characterization of Acanthamoeba spp. in stray cats from Madrid, Spain.

    Science.gov (United States)

    Montoya, Ana; Miró, Guadalupe; Saugar, José María; Fernández, Beatriz; Checa, Rocío; Gálvez, Rosa; Bailo, Begoña; Marino, Valentina; Piñero, José E; Lorenzo-Morales, Jacob; Fuentes, Isabel

    2018-03-01

    Acanthamoeba spp. is a widespread protozoan that has been isolated from air, dust, soil, water and biological samples. An opportunistic pathogen of humans and animals, it may cause ocular keratitis, encephalitis, and even multisystem disease. The frequency of Acanthamoeba in animals is unknown. The aim of present study was determine the presence of Acanthamoeba spp. in immunocompromised stray cats - animals possibly more likely to harbour the infection given their immunocompromised status and frequenting of contaminated environments. Of 307 cats examined, 55 were positive for feline immunodeficiency virus and/or feline leukaemia virus and therefore included in the study. Corneal scrapings were obtained to isolate Acanthamoeba spp. by culture and molecular detection by conventional and real time PCR. None of the samples examined directly by molecular methods were positive for Acanthamoeba spp. However, two (3.6%) cases of the cultured samples provided positive results, which were confirmed by subsequent molecular analysis. Sequencing assigned one isolate to genotype T4 and the other to T2. Since Acanthamoeba spp. may also infect animals and humans, the present findings may raise some public health and veterinary concerns. Copyright © 2018. Published by Elsevier Inc.

  18. Acanthamoeba, fungal, and bacterial keratitis: a comparison of risk factors and clinical features

    Science.gov (United States)

    Mascarenhas, Jeena; Lalitha, Prajna; Prajna, N. Venkatesh; Srinivasan, Muthiah; Das, Manoranjan; D’Silva, Sean S.; Oldenburg, Catherine E.; Borkar, Durga S.; Esterberg, Elizabeth J.; Lietman, Thomas M.; Keenan, Jeremy D.

    2013-01-01

    Purpose To determine risk factors and clinical signs that may differentiate between bacterial, fungal, and acanthamoeba keratitis among patients presenting with presumed infectious keratitis. Design Hospital-based cross-sectional study. Methods We examined the medical records of 115 patients with laboratory-proven bacterial keratitis, 115 patients with laboratory-proven fungal keratitis, and 115 patients with laboratory-proven acanthamoeba keratitis seen at Aravind Eye Hospital, Madurai, India, from 2006–2011. Risk factors and clinical features of the three organisms were compared using multinomial logistic regression. Results Of 95 patients with bacterial keratitis, 103 patients with fungal keratitis, and 93 patients with acanthamoeba keratitis who had medical records available for review, 287 (99%) did not wear contact lenses. Differentiating features were more common for acanthamoeba keratitis than for bacterial or fungal keratitis. Compared to patients with bacterial or fungal keratitis, patients with acanthamoeba keratitis were more likely to be younger and to have a longer duration of symptoms, and to have a ring infiltrate or disease confined to the epithelium. Conclusions Risk factors and clinical examination findings can be useful for differentiating acanthamoeba keratitis from bacterial and fungal keratitis. PMID:24200232

  19. Adherence of cysts and trophozoites of Acanthamoeba to unworn rigid gas permeable and soft contact lenses.

    Science.gov (United States)

    Sharma, S; Ramachandran, L; Rao, G N

    1995-10-01

    Contact lens related Acanthamoeba keratitis has been more often associated with the use of soft contact lenses than with the use of rigid gas permeable (RGP) contact lenses. We studied the adherence of Acanthamoeba cysts and trophozoites to unworn RGP (silicone acrylate and fluoropolymer) and low and high water content soft contact lenses marketed in India. A human corneal isolate of Acanthamoeba polyphaga suspended in saline (1 x 10(5) amoebae/mL) was used. Lens segments were exposed to A. polyphaga cysts or trophozoites with or without shaking. After exposure for zero to 7 hours, lenses were either washed or not washed and the adherence was determined using light microscopy and a hemocytometer (per square millimeter of the lens). Both cysts and trophozoites immediately adhered to all four types of lenses. Adhesion increased with an increase in exposure time. The number of adherent cysts and trophozoites was higher (P = 0.043-0.0003) in the unwashed group of lenses at all exposure times for all lenses. Among washed groups, adherence was greatest with RGP silicone acrylate and high water content soft lenses. Trophozoites of Acanthamoeba showed greater adherence to RGP lenses, whereas cysts showed greater adherence to high water content soft lenses. Shaking did not have a significant effect on adherence. Adhesion of Acanthamoeba to contact lenses may play an important role in the pathogenesis of Acanthamoeba keratitis.

  20. Fluorescent labeling of Acanthamoeba assessed in situ from corneal sectioned microscopy.

    Science.gov (United States)

    Marcos, Susana; Requejo-Isidro, Jose; Merayo-Lloves, Jesus; Acuña, A Ulises; Hornillos, Valentin; Carrillo, Eugenia; Pérez-Merino, Pablo; Del Olmo-Aguado, Susana; Del Aguila, Carmen; Amat-Guerri, Francisco; Rivas, Luis

    2012-10-01

    Acanthamoeba keratitis is a serious pathogenic corneal disease, with challenging diagnosis. Standard diagnostic methods include corneal biopsy (involving cell culture) and in vivo reflection corneal microscopy (in which the visualization of the pathogen is challenged by the presence of multiple reflectance corneal structures). We present a new imaging method based on fluorescence sectioned microscopy for visualization of Acanthamoeba. A fluorescent marker (MT-11-BDP), composed by a fluorescent group (BODIPY) inserted in miltefosine (a therapeutic agent against Acanthamoeba), was developed. A custom-developed fluorescent structured illumination sectioned corneal microscope (excitation wavelength: 488 nm; axial/lateral resolution: 2.6 μm/0.4-0.6 μm) was used to image intact enucleated rabbit eyes, injected with a solution of stained Acanthamoeba in the stroma. Fluorescent sectioned microscopic images of intact enucleated rabbit eyes revealed stained Acanthamoeba trophozoites within the stroma, easily identified by the contrasted fluorescent emission, size and shape. Control experiments show that the fluorescent maker is not internalized by corneal cells, making the developed marker specific to the pathogen. Fluorescent sectioned microscopy shows potential for specific diagnosis of Acanthamoeba keratitis. Corneal confocal microscopy, provided with a fluorescent channel, could be largely improved in specificity and sensitivity in combination with specific fluorescent marking.

  1. Pathogenicity of Korean isolates of Acanthamoeba by observing the experimental infection and zymodemes of five isoenzymes

    Science.gov (United States)

    Im, Kyung-Il; Seo, Dong Whan; Jeon, Soung-Hoo; Kim, Tae-Eun

    1999-01-01

    To determine the pathogenicity of Acanthamoeba spp. isolated in Korea and to develop a isoenzymatic maker, the mortality rate of infected mice, in vitro cytotoxicity against target cells and isoenzyme band patterns were observed. Five isolates of Acanthamoeba spp. (YM-2, YM-3, YM-4, YM-5, and YM-7) were used in this study as well as three reference Acanthamoeba spp. (A. culbertsoni, A. hatchetti, and A. royreba). According to the mortality rate of infected mice, Korean isolates could be categorized into three groups: high virulent (YM-4), low virulent (YM-2, YM-5, YM-7) and the nonpathogenic group (YM-3). In addition, the virulence of Acanthamoeba spp. was enhanced by brain passage in mice. In the cytotoxicity assay against chinese hamster ovary cells, especially, the cytotoxicity of brain-passaged amoebae was relatively higher than the long-term cultivated ones. The zymodeme patterns of glucose-6-phosphate dehydrogenase (G6PD), malate dehydrogenase (MDH), hexokinase (HK), glutamate oxaloacetate transaminase (GOT) and malic enzyme (ME) of Acanthamoeba spp. were different among each isolate, and also between long-term cultured amoebae and brain passaged ones. In spites of the polymorphic zymodemes, a slow band of G6PD and HK, and an intermediate band of MDH were only observed in pathogenic Acanthamoeba spp., which should be used as isoenzymatic makers. PMID:10388266

  2. Granulomatous inflammation in acanthamoeba keratitis: An immunohistochemical study of five cases and review of literature

    Directory of Open Access Journals (Sweden)

    Vemuganti G

    2005-01-01

    Full Text Available Purpose: Acanthamoeba keratitis usually presents as a necrotizing stromal inflammation. We report a rare presentation of granulomatous inflammation in Acanthamoeba keratitis Methods: Retrospective clinico-pathologic case series. Results: Five corneal tissues (3 corneal buttons, 2-eviscerated contents from patients suffering from severe Acanthamoeba keratitis not responding to anti-Acanthamoeba treatment, revealed a florid granulomotous inflammation with multinucleated giant cells in the posterior stroma and around Descemet′s membrane. Phagocytosed parasites were noted within the giant cells. Vascularization of the corneal stroma was noted in two cases. Immunophenotyping revealed a predominance of T lymphocytes and macrophages. Clinically, four of five cases had shown features of limbal and scleral involvement. Conclusion: Granulomatous inflammation in the posterior corneal stroma, is not an uncommon finding in Acanthamoeba keratitis and could possibly be immune-mediated, contributing to persistence and progression of disease. Clinical Relevance: Presence of granulomatous inflammation in Acanthamoeba keratitis, in most cases is associated with limbal and scleral involvement and therefore could be considered as one of the poor prognostic markers. Further studies are required to ascertain the specific clinical features and appropriate management strategies in these cases.

  3. Serine-like proteolytic enzymes correlated with differential pathogenicity in patients with acute Acanthamoeba keratitis.

    Science.gov (United States)

    de Souza Carvalho, F R; Carrijo-Carvalho, L C; Chudzinski-Tavassi, A M; Foronda, A S; de Freitas, D

    2011-04-01

    Acute ocular infection due to free-living amoebae of the genus Acanthamoeba is characterized by severe pain, loss of corneal transparency and, eventually, blindness. Proteolytic enzymes secreted by trophozoites of virulent Acanthamoeba strains have an essential role in the mechanisms of pathogenesis, including adhesion, invasion and destruction of the corneal stroma. In this study, we analysed the relationship between the extracellular proteases secreted by clinical isolates of Acanthamoeba and the clinical manifestations and severity of disease that they caused. Clinical isolates were obtained from patients who showed typical symptoms of Acanthamoeba keratitis. Trophozoites were cultivated axenically, and extracellular proteins were collected from cell culture supernatants. Secreted enzymes were partially characterized by gelatin and collagen zymography. Acanthamoeba trophozoites secreted proteases with different molecular masses, proteolysis rates and substrate specificities, mostly serine-like proteases. Different enzymatic patterns of collagenases were observed, varying between single and multiple collagenolytic activities. Low molecular weight serine proteases were secreted by trophozoites associated with worse clinical manifestations. Consequently, proteolytic enzymes of some Acanthamoeba trophozoites could be related to the degree of their virulence and clinical manifestations of disease in the human cornea. © 2010 European Society of Clinical Microbiology and Infectious Diseases. No claim to original US government works.

  4. Acanthamoeba, fungal, and bacterial keratitis: a comparison of risk factors and clinical features.

    Science.gov (United States)

    Mascarenhas, Jeena; Lalitha, Prajna; Prajna, N Venkatesh; Srinivasan, Muthiah; Das, Manoranjan; D'Silva, Sean S; Oldenburg, Catherine E; Borkar, Durga S; Esterberg, Elizabeth J; Lietman, Thomas M; Keenan, Jeremy D

    2014-01-01

    To determine risk factors and clinical signs that may differentiate between bacterial, fungal, and acanthamoeba keratitis among patients presenting with presumed infectious keratitis. Hospital-based cross-sectional study. We examined the medical records of 115 patients with laboratory-proven bacterial keratitis, 115 patients with laboratory-proven fungal keratitis, and 115 patients with laboratory-proven acanthamoeba keratitis seen at Aravind Eye Hospital, Madurai, India, from 2006-2011. Risk factors and clinical features of the 3 organisms were compared using multinomial logistic regression. Of 95 patients with bacterial keratitis, 103 patients with fungal keratitis, and 93 patients with acanthamoeba keratitis who had medical records available for review, 287 (99%) did not wear contact lenses. Differentiating features were more common for acanthamoeba keratitis than for bacterial or fungal keratitis. Compared to patients with bacterial or fungal keratitis, patients with acanthamoeba keratitis were more likely to be younger and to have a longer duration of symptoms, and to have a ring infiltrate or disease confined to the epithelium. Risk factors and clinical examination findings can be useful for differentiating acanthamoeba keratitis from bacterial and fungal keratitis. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Confoscan: an ideal therapeutic aid and screening tool in acanthamoeba keratitis.

    Science.gov (United States)

    Al Kharousi, Nadia; Wali, Upender K

    2012-10-01

    Although present worldwide, Acanthamoeba keratitis (AK) is a rare condition. It is a protozoal infection of the eye that is generally caused by wearing contaminated contact lenses or lens solutions. Confoscan and confocal scanning laser tomography (CSLT) are in vivo noninvasive diagnostic tools which provide high definition images of corneal microstructures. Laser in situ keratomileusis (LASIK) is a very common refractive surgery. We report a case series in which the first patient had contact lens induced Acanthamoeba keratitis with corneal epitheliopathy that was unresponsive to conservative treatment. Epithelial debridement was performed based on confoscan findings which confirmed the presence of Acanthamoeba cysts. Subsequently, the cornea re-epithelialized over two days. Another patient had CSLT prior to the LASIK which showed stromal cyst-like structures suggestive of Acanthamoeba keratitis. Four months after medical therapy, repeat CSLT was negative for Acanthamoeba cysts. Third patient was diagnosed with Acanthamoeba infection after undergoing lamellar keratoplasty. CSLT should be used as a screening procedure prior to any corneal refractive surgery to detect and treat protozoal and other infections preoperatively.

  6. Isolation and molecular characterization of Acanthamoeba from patients with keratitis in Spain.

    Science.gov (United States)

    Martín-Pérez, T; Criado-Fornelio, A; Martínez, J; Blanco, M A; Fuentes, I; Pérez-Serrano, J

    2017-10-01

    In order to improve our knowledge on the epidemiology of amoebic keratitis, as well as the identification of Acanthamoeba isolates, we have isolated Acanthamoeba spp. from five symptomatic patients in Spain in the present study. All isolates were grown in axenic liquid medium, with only one exception. The morphology of these isolates were characterized by optical and scanning electron microscopy. Their structural features corresponded to those of amphizoic amoebae (namely Acanthamoeba spp.). The molecular characterization of the five Acanthamoeba isolates yielded six sequences. Almost complete 18S rRNA gene sequences (>2000bp) were obtained from three isolates and partial sequences (∼1500bp) from the other two. A robust phylogenetic analysis based on the almost complete 18S rRNA sequence showed that four isolates belonged to the T4 genotype and the other one to the T3 genotype. However, all isolates were identified as T4 genotype using the ASA.S1 fragment. As previously suggested by other researchers, only a robust phylogenetic approach may be helpful in identifying Acanthamoeba genotypes. In addition, new data on the phylogenetic relationships among the Acanthamoeba genotypes is provided and discussed. Copyright © 2017 Elsevier GmbH. All rights reserved.

  7. Failure of molecular diagnostics of a keratitis-inducing Acanthamoeba strain.

    Science.gov (United States)

    Scheid, Patrick L; Balczun, Carsten

    2017-12-01

    An otherwise healthy 49-year-old female patient presented at the local hospital with severe keratitis in both inflamed eyes. She was a contact lens wearer and had no history of a corneal trauma. In our laboratory for medical parasitology Acanthamoebae were detected microscopically from the cornea scraping and from the fluid of the contact lens storage case after xenical culture and showed the typical cyst morphology of Acanthamoebae group II. The diagnosis of "Acanthamoeba keratitis" was established and successful therapy was provided. While the morphological microscopic method led to the correct diagnosis in this case, an in-house multiplex qPCR and a commercial qPCR showed false negative results regarding Acanthamoeba sp. The subsequent sequencing revealed the Acanthamoeba genotype T4. In the present case report, the inability to detect Acanthamoebae using qPCR only is presented. Therefore, we recommend the utilization of combined different assays for optimal diagnostic purposes. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Anti-Acanthamoeba activity of Tunisian Thymus capitatus essential oil and organic extracts.

    Science.gov (United States)

    Saoudi, Salma; Sifaoui, Ines; Chammem, Nadia; Reyes-Batlle, María; López-Arencibia, Atteneri; Pacheco-Fernández, Idaira; Pino, Verónica; Hamdi, Moktar; Jiménez, Ignacio A; Bazzocchi, Isabel L; Piñero, José E; Lorenzo-Morales, Jacob

    2017-12-01

    Acanthamoeba species are free-living amoebae widely distributed in the environment and which cause serious human infections. The treatment of Acanthamoeba infections is always very difficult and not constantly effective. More efficient drugs against Acanthamoeba must be developed and medicinal plants can be useful in this case. Our research focused on the examination of the anti-Acanthamoeba activity of the essential oil and the ethanolic-aqueous extract from Thymus capitatus L. The essential oil showed best activity with an IC 50 of 2.73 μg/ml. The conducted Bio-guided fractionation of thyme extract result to the identification of two active compounds against the trophozoite stage of Acanthamoeba: thymol and 2,3-dihydroxy-p-cymene. The results have clearly shown that the investigated products may be successfully used against Acanthamoeba infections. These molecules that are found in plants may be an alternative for the development of new drugs. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Molecular detection and genotyping of Acanthamoeba spp. among stray dogs using conjunctival swab sampling.

    Science.gov (United States)

    Karakuş, Mehmet; Aykur, Mehmet; Özbel, Yusuf; Töz, Seray; Dağcı, Hande

    2016-12-01

    Acanthamoeba is one of the most common free-living amoebas (FLA) that present in environment. In humans, Acanthamoeba can cause an infection of the eye termed Acanthamoeba keratitis, which mostly occurs in contact lens wearers. In the present study, we aimed to screen the presence of Acanthamoeba DNA in stray dogs using previously collected conjunctival swab samples in a hyper-endemic area for canine leishmaniasis. Totally, 184 dogs were included in the study and 27 of them (14.6%) were found positive for Acanthamoeba according to the 18s rRNA gene sequencing. Two different genotypes (T4 and T5) were identified and T5 was firstly reported in Turkey in the present study. Statistical analysis was performed and no correlation was found between Leishmania and Acanthamoeba positivity (PAcanthamoeba among stray dogs. Further studies are necessary to reveal the infection status and genotypes among dogs and its possible correlation with leishmaniasis. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Toll-like receptors in the brain of mice following infection with Acanthamoeba spp.

    Science.gov (United States)

    Wojtkowiak-Giera, Agnieszka; Derda, Monika; Kolasa-Wołosiuk, Agnieszka; Hadaś, Edward; Kosik-Bogacka, Danuta; Solarczyk, Piotr; Jagodziński, Paweł P; Wandurska-Nowak, Elżbieta

    2016-11-01

    The Toll-like receptors (TLRs) of the innate immune system play an important role in the recognition of pathogens such as bacteria, viruses, fungi, and parasites. In this study, we examined the changes in the level of expression of TLR2 and TLR4 mRNA and protein in the brains of mice infected with Acanthamoeba spp. The Acanthamoeba strains were isolated from a patient with Acanthamoeba keratitis (AK) (Ac55) and Malta Lake (Ac43). In the brain isolated from mice at 2 days post-infection (dpi) with Acanthamoeba strains Ac55 and Ac43, mRNAs for TLR2 and TLR4 were significantly more strongly expressed in comparison with the uninfected mice. In Acanthamoeba-infected mice, TLR2 and TLR4 expression was detected in neurons, glial cells, and endothelial cells within the neocortex. These receptors showed more intense expression in ependymocytes of the choroid plexus of infected mice at 2 dpi. Increased levels of TLR2 and TLR4 mRNA expression in infected mice suggest the involvement of these TLRs in the recognition of Acanthamoeba spp. pathogen-associated molecular patterns (PAMPs).

  11. Is safety infliximab during pregnancy in patients with inflammatory bowel disease? ¿El tratamiento con infliximab es seguro durante el embarazo en pacientes con enfermedad inflamatoria intestinal?

    Directory of Open Access Journals (Sweden)

    Federico Argüelles-Arias

    2012-02-01

    foetus. In fact, in our study and in some cases, its withdrawal may lead to a worsening of the disease. However, further control studies are required with larger samples to obtain more representative findings.Introducción: la enfermedad inflamatoria intestinal (EII es un trastorno crónico que debuta en la mayoría de los casos durante la edad reproductiva. Existen pocos datos sobre la seguridad durante el embarazo de los tratamientos disponibles, entre ellos los denominados biológicos, y estos están basados en resultados de casos esporádicos. Objetivos: determinar la seguridad del tratamiento con infliximab (IFX durante el embarazo en mujeres con EII. Un segundo objetivo es observar el efecto que sobre la actividad de la enfermedad tiene el abandono del tratamiento. Material y métodos: se trata de un estudio retrospectivo en el que se incluyeron mujeres con EII embarazadas y que estaban en tratamiento con IFX durante el embarazo. Se incluyeron en el estudio a 5 hospitales de España. La actividad de la enfermedad se midió según el CDAI en la enfermedad de Crohn (EC y la de la colitis ulcerosa (CU según el índice de Truelove-Witts en cada trimestre del embarazo. La edad gestacional, el peso y las enfermedades del feto se determinaron al nacimiento. Resultados: se incluyeron doce mujeres con una edad media de 29 años, 4 diagnosticadas de CU y 8 de EC, con una duración media de la enfermedad de 7 años. Todas salvo una, que se diagnosticó durante el embarazo estaban siendo tratadas con IFX en el momento de la concepción. Seis pacientes recibieron el tratamiento de forma ininterrumpida durante todo el embarazo, 2 suspendieron el tratamiento de forma voluntaria y a tres se les suspendió el tratamiento en el tercer trimestre. Recibieron una dosis media de IFX de 400 mg cada 8 semanas. De las 6 pacientes que recibieron tratamiento continuo, el 50% se mantuvo en remisión. De las pacientes que abandonaron el tratamiento, un 83,3% (todas menos una presentaron un

  12. Pathogenesis of Acanthamoeba keratitis: carbohydrate-mediated host-parasite interactions.

    Science.gov (United States)

    Yang, Z; Cao, Z; Panjwani, N

    1997-02-01

    Acanthamoeba keratitis is a sight-threatening corneal infection. In a recent study, the saccharide mannose has been shown to inhibit the binding of Acanthamoeba organisms to the epithelium of the cornea (L. D. Morton, G. L. McLaughlin, and H. E. Whiteley, Infect. Immun. 59:3819-3822, 1991). In an attempt to determine the molecular mechanism by which acanthamoebae adhere to the surface of the cornea, the present study was designed to determine whether Acanthamoeba castellanii derived from an infected human cornea (i) binds to mannose-containing glycoproteins (mannose-GPs) of corneal epithelium and (ii) expresses one or more mannose-binding proteins. Mannose-GPs of primary cell cultures of rabbit corneal epithelium were isolated by using three different agarose-conjugated, mannose-specific lectins. By electrophoresis blot-overlay assays, 35S-labeled acanthamoebae were shown to bind to mannose-GPs of corneal epithelium and to a neoglycoprotein, mannose-bovine serum albumin (mannose-BSA). 35S-labeled acanthamoebae also bound to microtiter wells coated with mannose-BSA in a concentration-dependent manner. The binding of amoebae to mannose-GPs was blocked by free methyl-alpha-D-mannopyranoside. The parasites did not bind to galactose-BSA or to many other proteins lacking mannose residues. A membrane-associated mannose-binding protein (136 kDa) of A. castellanii was isolated by affinity chromatography of detergent extracts of unlabeled parasites and of cell surface biotin-labeled parasites on a p-aminophenyl alpha-D-mannopyranoside-agarose column. The affinity-purified protein of the amoeba was shown to bind specifically to mannose-BSA. In summary, a mannose-binding protein is present on the surface membranes of Acanthamoeba, and corneal epithelial cells express Acanthamoeba-reactive GPs. One of the mechanisms of Acanthamoeba adhesion to the corneal surface may involve interactions between the mannose-binding protein of Acanthamoeba and mannose-GPs on the surface of

  13. A quantitative method to evaluate neutralizer toxicity against Acanthamoeba castellanii.

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    Buck, S L; Rosenthal, R A

    1996-09-01

    A standard methodology for quantitatively evaluating neutralizer toxicity against Acanthamoeba castellanii does not exist. The objective of this study was to provide a quantitative method for evaluating neutralizer toxicity against A. castellanii. Two methods were evaluated. A quantitative microtiter method for enumerating A. castellanii was evaluated by a 50% lethal dose endpoint method. The microtiter method was compared with the hemacytometer count method. A method for determining the toxicity of neutralizers for antimicrobial agents to A. castellanii was also evaluated. The toxicity to A. castellanii of Dey-Engley neutralizing broth was compared with Page's saline. The microtiter viable cell counts were lower than predicted by the hemacytometer counts. However, the microtiter method gives more reliable counts of viable cells. Dey-Engley neutralizing medium was not toxic to A. castellanii. The method presented gives consistent, reliable results and is simple compared with previous methods.

  14. Genotyping and phylogenetic analysis of Acanthamoeba isolates associated with keratitis.

    Science.gov (United States)

    Risler, Arnaud; Coupat-Goutaland, Bénédicte; Pélandakis, Michel

    2013-11-01

    We examined a partial SSU-rDNA sequence from 20 Acanthamoeba isolates associated with keratitis infections. The phylogenetic tree inferred from this partial sequence allowed to assign isolates to genotypes. Among the 20 isolates examined, 16 were found to be of the T4 genotype, 2 were T3, 1 was a T5, and 1 was a T2, confirming the predominance of T4 in infections. However, the study highlighted other genotypes more rarely associated with infections, particularly the T2 genotype. Our study is the second one to detect that this genotype is associated with keratitis. Additionally, the phylogenetic analyses showed five main emerging clusters, T4/T3/T11, T2/T6, T10/T12/T14, T13/T16, and T7/T8/T9/T17, regularly obtained whichever method was used. A similar branching pattern was found when the full rDNA sequence was investigated.

  15. Survival of pathogenic Mycobacterium abscessus subsp. massiliense in Acanthamoeba castellanii.

    Science.gov (United States)

    da Silva, Joas L; Nguyen, Jan; Fennelly, Kevin P; Zelazny, Adrian M; Olivier, Kenneth N

    2018-01-01

    We used an amoeba model to study the intracellular growth and cytotoxicity of clinical strains of Mycobacterium abscessus subsp. massiliense (Mabsm) isolated from 2 patients (one with cystic fibrosis, the other one with idiopathic bronchiectasis) during the early (smooth colonies) and late stage (rough colonies) of chronic pulmonary infection. Acanthamoeba castellanii were infected with Mabsm (MOI 100) and samples collected every 24 h for 72 h. Results showed Mabsm is able to survive in trophozoites and persist in cysts for at least 7 days. Late Mabsm demonstrated higher cytotoxicity toward A. castellanii when compared to early strains. A. castellanii is a useful in vitro host model to study infection of Mabsm clinical isolates. Published by Elsevier Masson SAS.

  16. Outcome of acanthamoeba keratitis treated with polyhexamethyl biguanide and propamidine.

    Science.gov (United States)

    Duguid, I G; Dart, J K; Morlet, N; Allan, B D; Matheson, M; Ficker, L; Tuft, S

    1997-10-01

    This study investigates the clinical outcome of Acanthamoeba keratitis treated with polyhexamethyl biguanide (PHMB) and propamidine isethionate (Brolene). A retrospective review of all patients treated for Acanthamoeba keratitis between September 1992 and February 1995 was carried out. All patients were treated with PHMB 0.02% and propamidine 0.1% hourly for 3 days, the frequency reduced to four to six times daily according to clinical response. Age, gender, result of laboratory investigation, duration of disease before diagnosis, visual acuity (VA) pretreatment and post-treatment, need for keratoplasty, and presence of adverse reaction were measured. One hundred eleven cases were identified in 105 patients (60 male, 45 female; mean age, 32). Ninety-two percent of infections were in contact lens wearers. The clinical diagnosis was confirmed by corneal culture or histopathology in 64 cases (57.7%). The diagnosis was made "early" (within 28 days) in 65 cases (58.6%). Twenty-one (18.9%) were "intermediate" (28 days-2 months) and 20 (18%) were "late" (> 2 months) diagnoses. Overall post-treatment VA was 6/12 or better in the majority (88/111, 79.3%) of cases, and 18 (16.2%) had VA of 6/36 or worse. The VA of > or = 6/12 was achieved by 90.8% of the early, 71.4% of the intermediate, and 65% of the late groups. Clinical relapses occurred in 19 patients on reducing the therapy. Treatment toxicity was never serious and consisted only of stinging or superficial punctate keratopathy. Keratoplasty was indicated in only ten patients, and disease activity was controlled adequately in all patients before grafting. Combined treatment with PHMB and propamidine is well tolerated, nontoxic, and effective. Typically, visual outcome is favorable and the requirement for keratoplasty reduced markedly.

  17. Acanthamoeba, bacterial, and fungal contamination of contact lens storage cases.

    Science.gov (United States)

    Gray, T B; Cursons, R T; Sherwan, J F; Rose, P R

    1995-01-01

    BACKGROUND--Microbial corneal infection is the most serious complication of contact lens wear. Contact lens cases are a recognised potential source of pathogens associated with corneal ulcers. METHODS--This survey established the incidence of protozoal, bacterial, and fungal contact lens case contamination in 101 asymptomatic daily wear cosmetic contact lens wearers from a domiciliary contact lens practice. RESULTS--Eighty two (81%) contact lens cases were found to be contaminated, with 19 (19%) sterile. Of all contact lens cases, 78 (77%) grew bacteria, 24 (24%) fungi, and 20 (20%) protozoa. Acanthamoeba spp were isolated from eight (8%) contact lens cases. Fifty six (55%) contact lens cases yielded mixed bacterial contamination. This is the first contact lens case survey in which hydrogen peroxide disinfection was the major method of contact lens disinfection (75% of subjects) and no home made saline was used. All the contaminating organisms were shown to possess the enzyme catalase that breaks down hydrogen peroxide to oxygen and water. The polymicrobial nature of the biofilms found in many contact lens cases is illustrated electron micrographically. CONCLUSION--Based on data from this and previous studies, the authors conclude with recommendations for contact lens wearers: (1) regular scrubbing of contact lens case interior to disrupt biofilms; (2) exposure of contact lens case to very hot water (> or = 70 degrees C) will kill Acanthamoeba contaminants; (3) allow contact lens case to air dry between uses; (4) if hydrogen peroxide disinfection is preferred, use a two step system; (5) replace contact lens case regularly. Images PMID:7626578

  18. Acanthamoeba and bacteria produce antimicrobials to target their counterpart

    Science.gov (United States)

    2014-01-01

    Background In the microbial ecosystem, microbes compete for space and nutrients. Consequently, some have developed the ability to kill or inhibit the growth of other competing microbes by producing antimicrobial substances. As the ‘producer’ species are generally immune to these substances, their compounds act on the competing microbial species and give the producer more space and access to nutrients for growth. Many currently used antibiotics were developed by exploiting this potential of certain microbes. Findings Here, the free-living amoeba, Acanthamoeba castellanii, was investigated for its antibacterial activity against representative Gram positive and Gram negative bacteria, while bacterial isolates were tested for their anti-amoebic properties. Conditioned medium from A. castellanii showed remarkable bactericidal properties against methicillin-resistant Staphylococcus aureus (MRSA) exhibiting almost 100% kill rate, but had limited effect against Acinetobacter sp., Pseudomonas aeruginosa and vancomycin-resistant Enterococcus faecalis (VRE). Similarly, the conditioned medium of E. coli K1 and Enterobacter sp., exhibited potent anti-Acanthamoebic effects in a concentration-dependent manner. Conditioned media of Acanthamoeba, E. coli K1 and Enterobacter sp. showed no cytotoxicity in vitro when tested against human brain microvascular endothelial cells. Active molecule/s in aforementioned amoebic and two bacterial conditioned media were 5 – 10 kDa, and castellanii conditioned medium showed potent bactericidal properties against MRSA. The active molecule(s) are heat- and pronase-resistant, and in the 5 to 10 kDa molecular mass range. Contrary to this, E. coli K1 and Enterobacter sp., conditioned medium showed anti-amoebic effects that are <5 kDa in molecular mass, suggestive of active metabolites. PMID:24479709

  19. Bowman’s layer encystment in cases of persistent Acanthamoeba keratitis

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    Yokogawa H

    2012-08-01

    Full Text Available Hideaki Yokogawa,1 Akira Kobayashi,1 Natsuko Yamazaki,1 Yasuhisa Ishibashi,2 Yosaburo Oikawa,3 Masaharu Tokoro,4 Kazuhisa Sugiyama11Department of Ophthalmology, Kanazawa University Graduate School of Medical Science, Kanazawa, 2Department of Ophthalmology, East Washinomiya Hospital, Kuki, 3Department of Medical Zoology, Kanazawa Medical University, Kahoku, 4Department of Parasitology, Kanazawa University Graduate School of Medical Science, Kanazawa, JapanBackground: The purpose of this study was to report Acanthamoeba encystment in Bowman’s layer in Japanese cases of persistent Acanthamoeba keratitis (AK.Methods: Laser confocal microscopic images of the cornea were obtained in vivo from 18 consecutive eyes from 17 confirmed AK patients. Retrospectively, 14 cases treated over 4 months were categorized as a nonpersistent group and three cases that required prolonged therapy for more than 6 months were categorized as a persistent group. Clinical outcomes based on final best-corrected visual acuity were retrospectively analyzed, and selected confocal images were evaluated qualitatively for abnormal findings.Results: The final best-corrected visual acuity was significantly lower (P < 0.01 for patients in the persistent group compared with that in the nonpersistent group. At the initial visit, in vivo confocal microscopy demonstrated Acanthamoeba cysts exclusively in the epithelial layer in both the nonpersistent group (80% and the persistent group (100%. At a subsequent follow-up visit, numerous Acanthamoeba cysts were observed in the epithelial cell layer and in Bowman’s layer in all patients with persistent AK, but Acanthamoeba cysts were undetectable in all cases with nonpersistent AK tested.Conclusion: Invasion of cysts into Bowman’s layer was characteristically observed in patients with persistence of AK. This finding suggests that invasion of Acanthamoeba cysts into Bowman’s layer may be a useful predictor for a persistent clinical

  20. Isolation and identification of Acanthamoeba strains from soil and tap water in Yanji, China.

    Science.gov (United States)

    Xuan, Yinghua; Shen, Yanqin; Ge, Yuxi; Yan, Gen; Zheng, Shanzi

    2017-06-30

    Members of the genus Acanthamoeba are widely distributed throughout the world, and some of them are considered pathogenic, as they are capable of causing corneal and central nervous system diseases. In this study, we isolated Acanthamoeba strains from soil and tap water in Yanji, China. We identified four strains of Acanthamoeba (CJY/S1, CJY/S2, CJY/S3, and CJY/W1) using mitochondrial DNA restriction fragment length polymorphism (mtDNA RFLP) analysis. Nuclear 18S rDNA sequences were used for phylogenetic analysis and species identification. Genotypic characterization of the isolates showed that they belonged to genotypes T4 (CJY/S1 and CJY/S2), T5 (CJY/S3), and T16 (CJY/W1). Sequence differences between CJY/S1 and Acanthamoeba castellanii Neff, CJY/S2 and Acanthamoeba KA/E7, and CJY/S3 and Acanthamoeba lenticulata 68-2 were 0.31, 0.2, and 0.26%, respectively. 18S ribosomal deoxyribonucleic acid (rDNA) of CJY/W1 had 99% sequence identity to that of Acanthamoeba sp. U/H-C1. Strains CJY/S1 and CJY/S2, isolated from soil, had similar mtDNA RFLP patterns, whereas strain CJY/W1, isolated from tap water, displayed a different pattern. To the best of our knowledge, this is the first report on the identification of genotypes T4, T5, and T16 from environmental sources in Yanji, China.

  1. Pathogenic strains of Acanthamoeba are recognized by TLR4 and initiated inflammatory responses in the cornea.

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    Hassan Alizadeh

    Full Text Available Free-living amoebae of the Acanthamoeba species are the causative agent of Acanthamoeba keratitis (AK, a sight-threatening corneal infection that causes severe pain and a characteristic ring-shaped corneal infiltrate. Innate immune responses play an important role in resistance against AK. The aim of this study is to determine if Toll-like receptors (TLRs on corneal epithelial cells are activated by Acanthamoeba, leading to initiation of inflammatory responses in the cornea. Human corneal epithelial (HCE cells constitutively expressed TLR1, TLR2, TLR3, TLR4, and TLR9 mRNA, and A. castellanii upregulated TLR4 transcription. Expression of TLR1, TLR2, TLR3, and TLR9 was unchanged when HCE cells were exposed to A. castellanii. IL-8 mRNA expression was upregulated in HCE cells exposed to A. castellanii. A. castellanii and lipopolysaccharide (LPS induced significant IL-8 production by HCE cells as measured by ELISA. The percentage of total cells positive for TLR4 was higher in A. castellanii stimulated HCE cells compared to unstimulated HCE cells. A. castellanii induced upregulation of IL-8 in TLR4 expressing human embryonic kidney (HEK-293 cells, but not TLR3 expressing HEK-293 cells. TLR4 neutralizing antibody inhibited A. castellanii-induced IL-8 by HCE and HEK-293 cells. Clinical strains but not soil strains of Acanthamoeba activated TLR4 expression in Chinese hamster corneas in vivo and in vitro. Clinical isolates but not soil isolates of Acanthamoeba induced significant (P< 0.05 CXCL2 production in Chinese hamster corneas 3 and 7 days after infection, which coincided with increased inflammatory cells in the corneas. Results suggest that pathogenic species of Acanthamoeba activate TLR4 and induce production of CXCL2 in the Chinese hamster model of AK. TLR4 may be a potential target in the development of novel treatment strategies in Acanthamoeba and other microbial infections that activate TLR4 in corneal cells.

  2. Quick survey for detection, identification and characterization of Acanthamoeba genotypes from some selected soil and water samples in Pakistan

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    Tania Tanveer

    2015-05-01

    Full Text Available Acanthamoeba is an opportunistic protozoan pathogen which is widely distributed in nature and plays a pivotal role in ecosystem. Acanthamoeba species may cause blinding keratitis and fatal granulomatous encephalitis involving central nervous system. In this study, we investigated the presence of Acanthamoeba in soil and water resources of Pakistan. Here, Acanthamoeba were recovered on non-nutrient agar plate lawn with E.coli and identified by morphological characteristics of the cyst. Furthermore PCR was performed with genus-specific primers followed by direct sequencing of the PCR product for molecular identification. Overall our PCR and sequencing results confirmed pathogenic genotypes including T4 and T15 from both soil and water samples. This is our first report of Acanthamoeba isolation from both soil and water resources of Pakistan which may serve as a potential treat to human health across the country.

  3. Quick survey for detection, identification and characterization of Acanthamoeba genotypes from some selected soil and water samples across Pakistan.

    Science.gov (United States)

    Tanveer, Tania; Hameed, Abdul; Gul, Asma; Matin, Abdul

    2015-01-01

    Acanthamoeba is an opportunistic protozoan pathogen which is widely distributed in nature and plays a pivotal role in ecosystem. Acanthamoeba species may cause blinding keratitis and fatal granulomatous encephalitis involving central nervous system. In this study, we investigated the presence of Acanthamoeba in soil and water resources of Pakistan. Here, Acanthamoeba were recovered on non-nutrient agar plate lawn with E. coli and identified by morphological characteristics of the cyst. Furthermore PCR was performed with genus-specific primers followed by direct sequencing of the PCR product for molecular identification. Overall our PCR and sequencing results confirmed pathogenic genotypes including T4 and T15 from both soil and water samples. This is our first report of Acanthamoeba isolation from both soil and water resources of Pakistan which may serve as a potential treat to human health across the country.

  4. Miltefosine and polyhexamethylene biguanide: a new drug combination for the treatment of Acanthamoeba keratitis.

    Science.gov (United States)

    Polat, Zubeyde A; Walochnik, Julia; Obwaller, Andreas; Vural, Ayse; Dursun, Ayhan; Arici, Mustafa K

    2014-03-01

    In this study, a series of compounds - miltefosine, polyhexamethylene biguanide, chlorhexidine and propamidine isethionate - and combinations of the latter three agents with miltefosine were prepared and used in a rat model for the topical treatment of Acanthamoeba keratitis. The corneas of rats were infected with Acanthamoeba hatchetti. On the fifth day, all corneas were microscopically examined in order to determine the grade of infections. Nine groups were then prepared: miltefosine (65.12 μg/mL); chlorhexidine (0.02%); polyhexamethylene biguanide (0.02%), propamidine isethionate (0.1%), miltefosine plus chlorhexidine, miltefosine plus polyhexamethylene biguanide; miltefosine plus propamidine isethionate; infected control; and a non-infected control group. The treatment was continued for 28 days. After the treatment, the corneas were excised and used for Acanthamoeba culture to investigate the presence of Acanthamoeba growth. For the determination of cytotoxicity of the drugs on L929 cells, colorimetric assays were performed. The best treatment results were obtained from the polyhexamethylene biguanide plus miltefosine group; the ratio of fully recovered eyes was 28.4%. It was proven that the miltefosine-polyhexamethylene biguanide combination yielded the highest anti-acanthamoebal activity in that approximately 86% of the eyes were cleared from amoebae. The cytotoxicity values of the miltefosine and the control groups were compared with other groups and found to be statistically different (P Acanthamoeba keratitis. © 2013 Royal Australian and New Zealand College of Ophthalmologists.

  5. Physiological, morphological, and immunochemical parameters used for the characterization of clinical and environmental isolates of Acanthamoeba.

    Science.gov (United States)

    Becker-Finco, A; Costa, A O; Silva, S K; Ramada, J S; Furst, C; Stinghen, A E; De Figueiredo, B C; De Moura, J; Alvarenga, L M

    2013-03-01

    The factors that characterize Acanthamoeba strains as harmless or potentially pathogenic have not been elucidated. Analysing the in vitro and in vivo parameters of Acanthamoeba samples, including heat tolerance at temperatures close to that of the human body, cytopathic effects, and their ability to cause infections in animals, has been proposed to identify their pathogenic potential. Another promising criterion for differentiating strains is the analysis of their biochemical and immunochemical properties. In this study, a comparative evaluation between clinical and environmental Acanthamoeba isolates was performed on the basis of physiological, morphological, and immunochemical criteria. Crude antigens were used to characterize the protein profiles by electrophoresis and immunize mice to produce polyclonal and monoclonal antibodies. The antibodies were characterized using ELISA, Western blotting, and immunofluorescence techniques. The results obtained with polyclonal antibodies suggest the presence of specific proteins for each studied isolate and co-reactive immunochemical profiles among conserved components. Ten monoclonal antibody clones were obtained; mAb3 recognized 3 out of 4 samples studied. The results of this study may help standardize criteria for identifying and characterizing Acanthamoeba strains. Taken together, our results support the view that a set of features may help differentiate Acanthamoeba species and isolates.

  6. Successful medical therapy of Acanthamoeba keratitis with topical chlorhexidine and propamidine.

    Science.gov (United States)

    Seal, D; Hay, J; Kirkness, C; Morrell, A; Booth, A; Tullo, A; Ridgway, A; Armstrong, M

    1996-01-01

    Following laboratory studies on new potential chemotherapy for Acanthamoeba keratitis, when chlorhexidine and propamidine provided an additive in vitro effect, a series of 12 patients with culture-proven Acanthamoeba keratitis from three UK centres was monitored during and after therapy. In all cases the clinical diagnosis was confirmed by amoebal culture. In some instances identification of the protozoa by direct microscopy of corneal tissue was possible. The medication was provided topically in drop form until the keratitis had resolved. In vitro sensitivity to chlorhexidine and propamidine was performed on all isolates and compared with sensitivity to a range of other drugs used for treatment of the infection. In vitro drug testing confirmed that trophozoites and cysts of all 12 Acanthamoeba isolates were fully sensitive to chlorhexidine and propamidine. Therapy was satisfactory for controlling and eradicating the acanthamoebal infection in all patients. Three patients developed discrete stromal infiltration at the site of infection that resolved 1 week after commencing therapy, with or without use of steroids. Two patients developed a late inflammatory effect in the stromal scar at 6 months, which resolved with steroids. No clinical evidence of chlorhexidine toxicity was found in any patients. The combination of topical chlorhexidine and propamidine was very effective for treating Acanthamoeba keratitis provided the drugs were continued for a sufficient period. No drug toxicity or resistance of Acanthamoeba isolates was observed in the 12 treated patients.

  7. The effectiveness of soft contact lens disinfection systems against Acanthamoeba on the lens surface.

    Science.gov (United States)

    Liedel, K K; Begley, C G

    1996-03-01

    This investigation compared the efficacy of three widely used contact lens disinfection systems against an ocular isolate of Acanthamoeba polyphaga. Twenty-seven worn Ciba NewVues lenses were quartered, heat sterilized and inoculated with Acanthamoeba. Lens quarters were then randomly assigned to three experimental groups, with Group A lenses exposed to cleaner and saline rinse only, Group B to disinfection only, and Group C to both cleaner and disinfection. One quarter of each lens served as a control and the other three quarters were experimental. Quantification of viable Acanthamoeba remaining on the lens was performed after each step of the disinfection process. Group A lenses showed no significant difference between the treatments, or the treatments and the control. Group B lenses demonstrated a significant difference (p = 0.0001) between the treatments and the control. In Group C (cleaning and disinfection), the control lens quarters were significantly different (p = 0.037) from the experimental group, but there was no significant difference between the treatments. All three disinfection regimens were very effective in reducing the number of viable Acanthamoeba on the contact lens surface. In the absence of proper cleaning (Group B), AOSept was the most effective of the three. These results also show the importance of thoroughly rubbing the contact lens surface to decrease the number of Acanthamoeba.

  8. Isolation and Genotyping of Acanthamoeba Strains from Environmental Sources in Ahvaz City, Khuzestan Province, Southern Iran

    Science.gov (United States)

    Rahdar, M; Niyyati, M; Salehi, M; Feghhi, M; Makvandi, M; Pourmehdi, M; Farnia, S

    2012-01-01

    Background Acanthamoeba spp. are free-living amoebae commonly found in the environmental sources such as water, soil, and air. This ubiquitous amoeba is the causative agent of amoebic keratitis (AK). The objective of the present study was to investigate the presence of Acanthamoeba spp. in water and soil sources in Ahvaz City, Khuzestan Province, southern Iran. Methods In general, 110 samples of water and soil were taken from different localities of Ahvaz including agricultural canals, rivers, and swimming pools. Filtration and cultivation were carried out on non-nutrient agar medium (NNA). Axenic cultivation was performed for all of positive isolates. PCR analysis was conducted on positive samples. Sequencing was done for 15 PCR products. Genotypes were identified by Blast search and homology analysis. Results Acanthamoeba spp. was found in 43 (71.6%) of samples of water and 13 (26%) soil samples. Genotyping of 15 samples proved that Acanthamoeba belonged to T4 (86.6%), T2 (6.6%), and T5 (6.6%) genotypes. Conclusion TYI-S-33 medium could be better than PYG medium for Acanthamoeba axenic culture. PMID:23323088

  9. Programmed cell death in Acanthamoeba castellanii Neff induced by several molecules present in olive leaf extracts.

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    Ines Sifaoui

    Full Text Available Therapy against Acanthamoeba infections such as Granulomatous Amoebic Encephalitis (GAE and Acanthamoeba Keratitis (AK, remains as an issue to be solved due to the existence of a cyst stage which is highly resistant to most chemical and physical agents. Recently, the activity of Olive Leaf Extracts (OLE was demonstrated against Acanthamoeba species. However, the molecules involved in this activity were not identified and/or evaluated. Therefore, the aim of this study was to evaluate the activity of the main molecules which are present in OLE and secondly to study their mechanism of action in Acanthamoeba. Among the tested molecules, the observed activities ranged from an IC50 of 6.59 in the case of apigenine to an IC50 > 100 μg/ml for other molecules. After that, elucidation of the mechanism of action of these molecules was evaluated by the detection of changes in the phosphatidylserine (PS exposure, the permeability of the plasma membrane, the mitochondrial membrane potential and the ATP levels in the treated cells. Vanillic, syringic and ursolic acids induced the higher permeabilization of the plasma membrane. Nevertheless, the mitochondrial membrane was altered by all tested molecules which were also able to decrease the ATP levels to less than 50% in IC90 treated cells after 24 h. Therefore, all the molecules tested in this study could be considered as a future therapeutic alternative against Acanthamoeba spp. Further studies are needed in order to establish the true potential of these molecules against these emerging opportunistic pathogenic protozoa.

  10. Amoebicidal Activity of Caffeine and Maslinic Acid by the Induction of Programmed Cell Death in Acanthamoeba

    Science.gov (United States)

    Martín-Navarro, Carmen M.; López-Arencibia, Atteneri; Sifaoui, Ines; Reyes-Batlle, María; Fouque, Emilie; Osuna, Antonio; Valladares, Basilio; Piñero, José E.; Héchard, Yann; Maciver, Sutherland K.

    2017-01-01

    ABSTRACT Free-living amoebae of the genus Acanthamoeba are the causal agents of a sight-threatening ulceration of the cornea called Acanthamoeba keratitis, as well as the rare but usually fatal disease granulomatous amoebic encephalitis. Although there are many therapeutic options for the treatment of Acanthamoeba infections, they are generally lengthy and/or have limited efficacy. For the best clinical outcome, treatments should target both the trophozoite and the cyst stages, as cysts are known to confer resistance to treatment. In this study, we document the activities of caffeine and maslinic acid against both the trophozoite and the cyst stages of three clinical strains of Acanthamoeba. These drugs were chosen because they are reported to inhibit glycogen phosphorylase, which is required for encystation. Maslinic acid is also reported to be an inhibitor of extracellular proteases, which may be relevant since the protease activities of Acanthamoeba species are correlated with their pathogenicity. We also provide evidence for the first time that both drugs exert their anti-amoebal effects through programmed cell death. PMID:28320723

  11. Various confocal scan features of cysts and trophozoites in cases with Acanthamoeba keratitis.

    Science.gov (United States)

    Rezaei Kanavi, Mozhgan; Naghshgar, Nima; Javadi, Mohammad Ali; Sadat Hashemi, Marzieh

    2012-01-01

    To describe the various confocal scan features of cysts and trophozoites in patients with Acanthamoeba keratitis and to specify the associated findings. In a retrospective study of cases between June 2005 and June 2010, we reviewed all the recorded confocal scan images of patients given a high index in regards to clinical suspicion of Acanthamoeba keratitis, in order to specify the various morphometric and morphologic features of Acanthamoeba cysts and trophozoites and to characterize the associated findings in such cases. Confocal scan images of 170 eyes from 170 patients were reviewed. Bilayered, target-shaped, coffee-bean and rod-shaped appearances of the cysts were observed in 100%, 82.9%, 36.4%, and 17.5% of cases, respectively. Single file arrangement of the cysts was noticed in 22 cases. The mean size of the cysts was 18.9 µm (range 10-39.6). In all cases, trophozoites were observed as pear-shaped or irregularly wedge-shaped structures, some surrounded by a brilliant halo and some exhibiting fine pseudopodia-like extensions, with mean size of 30.2 µm (range 19.2-55.6). Keratoneuritis and the anterior stromal honeycomb pattern were seen in 28.2% and 5.9% of cases, respectively. To our knowledge, this is the largest case-series study on confocal scan features of Acanthamoeba cysts and trophozoites in cases with clinical diagnosis of Acanthamoeba keratitis specifying the morphologic and morphometric criteria of this infectious organism and the associated findings.

  12. Failure of chemotherapy in the first reported cases of Acanthamoeba keratitis in Pakistan.

    Science.gov (United States)

    Siddiqui, Ruqaiyyah; Chaudhry, Tanveer; Lakhundi, Sahreena; Ahmad, Khabir; Khan, Naveed Ahmed

    2014-01-01

    Acanthamoeba keratitis is a painful and progressive infection of the cornea that can result in loss of vision. Here, for the first time in Pakistan, we report two cases of Acanthamoeba keratitis. The first patient was a 37-year-old female who presented with severe itching, redness, pain, along with loss of vision. The patient was a regular soft contact lens wearer. The second patient was a 25-year-old female who had been using soft contact lenses for the past two years. She presented with a burning sensation and extreme pain, along with loss of vision. Both patients were treated for a possible microbial keratitis with topical moxifloxacin hydrochloride drops, vancomycin drops, propamidine isethionate ointment, amphotericin B drops, and amikacin drops. However, the response was inadequate and both patients were referred for corneal transplant. Acanthamoeba castellanii was isolated by placing contact lenses and contact lens cases on non-nutrient agar plates containing a lawn of non-invasive Escherichia coli K-12 HB101 bacteria. The polymerase chain reaction (PCR) using genus-specific probes confirmed the identity of Acanthamoeba spp., whereas the morphological characteristics of trophozoites and cysts were suggestive of A. castellanii in both cases. With growing use of contact lenses for vision correction/cosmetic use coupled with sub-standard lens care in this region and the possibility of non-contact lens-associated Acanthamoeba keratitis, a need for increased awareness of this sight-threatening infection is discussed further.

  13. Acanthamoeba keratitis: 10-year study at a tertiary eye care center in Hong Kong.

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    Chin, Joyce; Young, Alvin L; Hui, Mamie; Jhanji, Vishal

    2015-04-01

    To review clinical presentation, investigation results and treatment outcomes of patients with Acanthamoeba keratitis (AK) at a tertiary eye care center in Hong Kong. A retrospective case review was performed for cases of Acanthamoeba keratitis diagnosed at the Prince of Wales Hospital, Hong Kong over a 10-year period. Fifteen eyes of 13 patients were treated for AK over the study period. 12 out of 13 patients (92.3%) were contact lens wearers. All patients presented with blurred vision and pain, while 9 patients (69.2%) presented with redness of the affected eye. The most common ocular sign was diffuse corneal haze or ground glass appearance of the cornea (69.2%) followed by anterior chamber inflammation (53.8%), ring infiltrate (38.4%), epithelial defect (38.4%), perineural infiltrates (30.7%) and satellite lesions (15.3%). Acanthamoeba was detected on corneal scrapings in 4 eyes and on confocal microscopy in 4 eyes. The mean duration of treatment was 140 ± 50.8 days. Surgical intervention was required in two cases due to uncontrolled eye infection and progressive corneal thinning. All patients had improvement in visual acuity after treatment. Patients with AK exhibited a wide spectrum of clinical characteristics. Improper care and usage of contact lenses is a major risk factor for Acanthamoeba keratitis. Diagnosis of AK remained a challenge. Timely diagnosis and appropriate treatment with amoebicidal drugs can improve the outcomes of Acanthamoeba keratitis. Copyright © 2014 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  14. Autofluorescence Signatures of Seven Pathogens: Preliminary in Vitro Investigations of a Potential Diagnostic for Acanthamoeba Keratitis.

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    Molyneux, Philippa M; Kilvington, Simon; Wakefield, Matthew J; Prydal, Jeremy I; Bannister, Nigel P

    2015-12-01

    Acanthamoeba keratitis can cause devastating damage to the human cornea and is often difficult to diagnose by routine clinical methods. In this preliminary study, we investigated whether Acanthamoeba may be distinguished from other common corneal pathogens through its autofluorescence response. Although only a small number of pathogens were studied, the identification of a unique Acanthamoeba signature would indicate that autofluorescence spectroscopy as a diagnostic method merits further investigation. Samples of 7 common pathogens (Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Elizabethkingia miricola, Achromobacter ruhlandii, Candida albicans, and Acanthamoeba castellanii) in solution were excited with ultraviolet light at a number of successive, narrow wavebands between 260 and 400 nm, and their fluorescence response recorded. Principal Component Analysis was used to allow better visualization of the differences in response to UV light for different species. Acanthamoeba was found to possess a characteristic autofluorescence response and was easily distinguished from E. coli, S. aureus, P. aeruginosa, E. miricola, A. ruhlandii, and C. albicans over a wide range of excitation wavelengths. We also found a clear discrimination between E. coli, C. albicans, and P. aeruginosa at an excitation wavelength of 274 nm, whereas E. miricola, S. aureus, and A. ruhlandii could be separated using an excitation wavelength of 308 nm. Our results, although preliminary, indicate that autofluorescence spectroscopy shows promise as a diagnostic technique for keratitis. We intend to expand the set of pathogens studied before assessing the feasibility of the technique in vivo by introducing cultures onto pig corneas.

  15. Detection and quantification of human adenovirus genomes in Acanthamoeba isolated from swimming pools

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    RODRIGO STAGGEMEIER

    2016-01-01

    Full Text Available ABSTRACT Acanthamoeba is the most common free-living environmental amoeba, it may serve as an important vehicle for various microorganisms living in the same environment, such as viruses, being pathogenic to humans. This study aimed to detect and quantify human adenoviruses (HAdV in Acanthamoebas isolated from water samples collected from swimming pools in the city of Porto Alegre, Southern Brazil. Free-living amoebae of the genus Acanthamoeba were isolated from water samples, and isolates (n=16 were used to investigate the occurrence of HAdVs. HAdV detection was performed by quantitative real-time polymerase chain reaction (qPCR. HAdVs were detected in 62.5% (10/16 of Acanthamoeba isolates, ranging from 3.24x103 to 5.14x105 DNA copies per milliliter of isolate. HAdV viral loads found in this study are not negligible, especially because HAdV infections are associated with several human diseases, including gastroenteritis, respiratory distress, and ocular diseases. These findings reinforce the concept that Acanthamoeba may act as a reservoir and promote HAdV transmission through water.

  16. Programmed cell death in Acanthamoeba castellanii Neff induced by several molecules present in olive leaf extracts.

    Science.gov (United States)

    Sifaoui, Ines; López-Arencibia, Atteneri; Martín-Navarro, Carmen Mª; Reyes-Batlle, María; Wagner, Carolina; Chiboub, Olfa; Mejri, Mondher; Valladares, Basilio; Abderrabba, Manef; Piñero, José E; Lorenzo-Morales, Jacob

    2017-01-01

    Therapy against Acanthamoeba infections such as Granulomatous Amoebic Encephalitis (GAE) and Acanthamoeba Keratitis (AK), remains as an issue to be solved due to the existence of a cyst stage which is highly resistant to most chemical and physical agents. Recently, the activity of Olive Leaf Extracts (OLE) was demonstrated against Acanthamoeba species. However, the molecules involved in this activity were not identified and/or evaluated. Therefore, the aim of this study was to evaluate the activity of the main molecules which are present in OLE and secondly to study their mechanism of action in Acanthamoeba. Among the tested molecules, the observed activities ranged from an IC50 of 6.59 in the case of apigenine to an IC50 > 100 μg/ml for other molecules. After that, elucidation of the mechanism of action of these molecules was evaluated by the detection of changes in the phosphatidylserine (PS) exposure, the permeability of the plasma membrane, the mitochondrial membrane potential and the ATP levels in the treated cells. Vanillic, syringic and ursolic acids induced the higher permeabilization of the plasma membrane. Nevertheless, the mitochondrial membrane was altered by all tested molecules which were also able to decrease the ATP levels to less than 50% in IC90 treated cells after 24 h. Therefore, all the molecules tested in this study could be considered as a future therapeutic alternative against Acanthamoeba spp. Further studies are needed in order to establish the true potential of these molecules against these emerging opportunistic pathogenic protozoa.

  17. Potentially pathogenic Acanthamoeba genotype T4 isolated from dental units and emergency combination showers.

    Science.gov (United States)

    Castro-Artavia, Esteban; Retana-Moreira, Lissette; Lorenzo-Morales, Jacob; Abrahams-Sandí, Elizabeth

    2017-12-01

    Acanthamoeba is the genus of free-living amoebae that is most frequently isolated in nature. To date, 20 Acanthamoeba genotypes have been described. Genotype T4 is responsible for approximately 90% of encephalitis and keratitis cases. Due to the ubiquitous presence of amoebae, isolation from environmental sources is not uncommon; to determine the clinical importance of an isolation, it is necessary to have evidence of the pathogenic potential of amoebae. The aim of this study was to physiologically characterise 8 Acanthamoeba T4 isolates obtained from dental units and emergency combination showers and to determine their pathogenic potential by employing different laboratory techniques. Eight axenic cultures of Acanthamoeba genotype T4 were used in pathogenic potential assays. Osmotolerance, thermotolerance, determination and characterisation of extracellular proteases and evaluation of cytopathic effects in MDCK cells were performed. All of the isolates were osmotolerant, thermotolerant and had serine proteases from 44-122 kDa. Two isolates had cytopathic effects on the MDCK cell monolayer. The presence of Acanthamoeba T4 with pathogenic potential in areas such as those tested in this study reaffirms the need for adequate cleaning and maintenance protocols to reduce the possibility of infection with free-living amoebae.

  18. Identification and typing of free-living Acanthamoeba spp. by MALDI-TOF MS Biotyper.

    Science.gov (United States)

    Del Chierico, Federica; Di Cave, David; Accardi, Cristel; Santoro, Maristella; Masotti, Andrea; D'Alfonso, Rossella; Berrilli, Federica; Urbani, Andrea; Putignani, Lorenza

    2016-11-01

    Over the years, the potential pathogenicity of Acanthamoeba for humans and animals has gained increasing attention from the scientific community. More than 24 species belong to this genus, however only some of them are causative agents of keratitis and encephalitis in humans. Due to technical difficulties in diagnosis, these infections are likely to be under-detected. The introduction of 18S rDNA amplification for the identification of Acanthamoeba has dramatically enhanced diagnosis performances, but the attestation of genotyping requires supplementary sequencing-based procedures. In this study, 15 Acanthamoeba strains were collected and grown on nutrient agar media. Each strain was genotyped by end-point PCR assay for the amplification of the 18S rDNA gene and the genotype was assigned by sequencing analysis through neighbor joining phylogenetic tree. In order to optimize standardization of the MALDI-TOF MS assay, we established the collection time point at the cystic phase. Two strains of each genotype were randomly chosen to customize the biotyper database. For all strains, 24 spectral measurements were acquired and submitted to identification and cluster analysis of spectra. The obtained results highlighted the correct identification of Acanthamoeba strains and the overlapping of spectra dendrogram clusters to the 18S genotype assignations. In conclusion, the MALDI-TOF MS Biotyper revealed the capability to identify and genotype the Acanthamoeba strains, providing a new frontier in the diagnostic identification of amaebae and in taxonomic and phylogenetic studies. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Isolation and Molecular Characterization of Acanthamoeba Strains from Dental Units in Costa Rica.

    Science.gov (United States)

    Retana-Moreira, Lissette; Abrahams-Sandí, Elizabeth; Castro-Artavia, Esteban; Fernández-Sánchez, Ana; Castro-Castillo, Alfredo; Reyes-Batlle, María; Lorenzo-Morales, Jacob

    2015-01-01

    Free-living amoebae are protozoa widely distributed in nature, which can be found in a variety of environments. Four genera are recognized as causal agents of infections in humans and animals: Acanthamoeba, Naegleria, Balamuthia, and Sappinia. In this study, the presence of Acanthamoeba in dental units was determined and the isolates obtained were molecularly characterized; osmotolerance and thermotolerance assays were also performed to evaluate multiplication under these conditions, frequently associated with pathogenicity. The morphological analysis and partial sequencing of the 18S rDNA gene revealed the presence of Acanthamoeba genotype T4 in 14% of the units sampled. Osmotolerance and thermotolerance tests were positive for more than 80% of the isolates. Up to date, this is the first study that reports the detection, identification, and genotyping of Acanthamoeba isolated from dental units in Costa Rica and even in Latin-America. Further assays to determine the potential pathogenicity of these Acanthamoeba isolates are underway. © 2015 The Author(s) Journal of Eukaryotic Microbiology © 2015 International Society of Protistologists.

  20. Molecular Characterization of Acanthamoeba Isolates from Surface Resting Waters in Northwest Iran

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    Esmaeil FALLAH

    2017-09-01

    Full Text Available Background: Acanthamoeba is an opportunistic amphizoic protozoan found in different fresh water sources. The aim of this study was to identify and characterize Acanthamoeba isolates from surface resting waters, in Northwest Iran.Methods: Samples were collected from twenty-two different areas, between May and Sep 2014. After filtration, samples were cultivated on non-nutrient agar. The extracted DNAs were amplified and sequenced using partial 18S rRNA in order to genotype and phylogenetic analyses.Results: Thirty-four (68% out of 50 collected samples were positive for free-living amoebae based on both culture and morphological characterizations but 28 samples were identified as Acanthamoeba spp. by PCR. Sequentially, one isolate was identified as A. lenticulata, (T5 (AN: KP940443, identity 99.7%-100%, and divergence 0.3% whilst other sequenced isolates identified Acanthamoeba spp. (AN: KP940444-45 as very similar to A. rhysodes and A. royreba with identity 100% and divergence 0%. Conclusion: Surface resting waters in Northwest Iran, were potentially contaminated with pathogenic amphizoic protozoan. Further studies will be required to determine other Acanthamoeba species and genotypes in the region.

  1. Isolation and Genotyping of Acanthamoeba spp. as Neglected Parasites in North of Iran.

    Science.gov (United States)

    Shokri, Azar; Sarvi, Shahabeddin; Daryani, Ahmad; Sharif, Mehdi

    2016-08-01

    Acanthamoeba, a free-living amoeba, is widely distributed in the environment, water sources, soil, dust, and air. It can cause keratitis in contact lens wearers with poor hygiene and also fatal granulomatous amebic encephalitis (GAE) in immunocompromised hosts. The aim of this study was to gain some insights into the distribution and genotypes of the potentially pathogenic species of Acanthamoeba present in water sources in north of Iran. Total 43 Acanthamoeba species were isolated from 77 water samples taken from different water sources within the Mazandaran province in Northern Iran (Sari city and suburbs). Isolates were identified based on cyst and trophozoite morphological characteristics as well genetics. PCR fragments corresponding to the small-subunit 18S rRNA gene were sequenced for 20 of 43 positive isolates. The results revealed that 83.3% of sequenced isolates belonged to the T4 genotype and the rest belonged to the T2 genotype. Our results indicated that Acanthamoeba is widely distributed in Sari city. As the incidence in Iran of amoebic keratitis has increased in recent years, the exact estimation of the prevalence of this amoeba and its predominant genotype may play a crucial role in prevention of the disease. Sari city has several rivers, seashores, and natural recreational amenities, which attract visitors during the year. This is the first report of Acanthamoeba genotypes from water sources in Sari city, Mazandaran province of Iran, and the results suggest that more attention is needed to protect the visiting population and immunocompromised individuals.

  2. Acanthamoeba genotypes T3 and T4 as causative agents of amoebic keratitis in Mexico.

    Science.gov (United States)

    Omaña-Molina, Maritza; Vanzzini-Zago, Virginia; Hernandez-Martinez, Dolores; Gonzalez-Robles, Arturo; Salazar-Villatoro, Lizbeth; Ramirez-Flores, Elizabeth; Oregon-Miranda, Eric; Lorenzo-Morales, Jacob; Martinez-Palomo, Adolfo

    2016-02-01

    Free-living amoebae (FLA) are widely distributed worldwide. Some genera included in this group act as opportunistic pathogens causing fatal encephalitis and Acanthamoeba keratitis (AK), a sight-threatening infection of the cornea associated with the use of soft contact lenses that could even end in blindness if an early diagnosis and treatment are not achieved. Furthermore, the numbers of AK cases keep rising worldwide mainly due to an increase of contact lens wearers and lack of hygiene in the maintenance of lenses and their cases. In Mexico, no cases of AK have been described so far although the isolation of other pathogenic FLA such as Naegleria fowleri and Balamuthia mandrillaris from both clinical and environmental sources has been reported. The present study reports two cases of Acanthamoeba keratitis diagnosed in two patients admitted to the Hospital "Luis Sánchez Bulnes" for Blindness Prevention in Mexico City, Mexico. Corneal scrapes and contact lenses were checked for the presence of Acanthamoeba strains in both patients. Strains were axenized after initial isolation to classify at the genotype level. After sequencing the diagnostic fragment 3 (DF3) region located on the 18S ribosomal DNA (rDNA) gene of Acanthamoeba, genotype T3 and genotype T4 were identified in clinical case 1 and 2, respectively. To our knowledge, these are the first reported cases of AK in Mexico in the literature and the first description of Acanthamoeba genotypes T3 and T4 as causative agents of amoebic infection.

  3. Riboflavin and ultraviolet-A as adjuvant treatment against Acanthamoeba cysts

    Science.gov (United States)

    Lamy, Ricardo; Chan, Elliot; Good, Samuel D; Cevallos, Vicky; Porco, Travis C; Stewart, Jay M

    2015-01-01

    Background Experimental studies have shown that the standard dose of R or R+UVA as solo treatment are not able to exterminate Acanthamoeba cysts or even trophozoites. The purpose of this study is to determine whether the application of R+UVA can enhance the cysticidal effects of cationic antiseptic agents in vitro. Methods The log of either polyhexamethylene biguanide (PHMB) or chlorhexidine minimal cysticidal concentration (MCC) in solutions containing riboflavin (concentrations 0.1 %; 0.05% and 0.025 %) plus either Acanthamoeba castellanii cysts or Acanthamoeba polyphaga cysts was determined and compared in groups treated with UVA 30 mW/cm2 for 30 min and in control groups (with no exposure to UVA). A permutation test was used to determine the P-value associated with treatment. Results Regardless of the riboflavin concentration and UVA treatment condition, no trophozoites were seen in plates where the cysts were previously exposed to cationic antiseptic agents concentrations ≥ 200 µg/mL for Acanthamoeba castellanii samples and ≥ 100 µg/mL for Acanthamoeba polyphaga samples. There was no statistical evidence that R+UVA treatment was associated with MCC (P = 0.82). Conclusion R+UVA in doses up to 10 times higher than recommended for corneal crosslinking does not enhance the cysticidal effect of either polyhexamethylene biguanide or chlorhexidine in vitro. PMID:26355273

  4. Amoebicidal Activity of Caffeine and Maslinic Acid by the Induction of Programmed Cell Death in Acanthamoeba.

    Science.gov (United States)

    Martín-Navarro, Carmen M; López-Arencibia, Atteneri; Sifaoui, Ines; Reyes-Batlle, María; Fouque, Emilie; Osuna, Antonio; Valladares, Basilio; Piñero, José E; Héchard, Yann; Maciver, Sutherland K; Lorenzo-Morales, Jacob

    2017-06-01

    Free-living amoebae of the genus Acanthamoeba are the causal agents of a sight-threatening ulceration of the cornea called Acanthamoeba keratitis, as well as the rare but usually fatal disease granulomatous amoebic encephalitis. Although there are many therapeutic options for the treatment of Acanthamoeba infections, they are generally lengthy and/or have limited efficacy. For the best clinical outcome, treatments should target both the trophozoite and the cyst stages, as cysts are known to confer resistance to treatment. In this study, we document the activities of caffeine and maslinic acid against both the trophozoite and the cyst stages of three clinical strains of Acanthamoeba These drugs were chosen because they are reported to inhibit glycogen phosphorylase, which is required for encystation. Maslinic acid is also reported to be an inhibitor of extracellular proteases, which may be relevant since the protease activities of Acanthamoeba species are correlated with their pathogenicity. We also provide evidence for the first time that both drugs exert their anti-amoebal effects through programmed cell death. Copyright © 2017 American Society for Microbiology.

  5. Effect of microwave treatment to acanthamoeba: a possibility of contact lens storage case sterilization?

    International Nuclear Information System (INIS)

    Hiti, K.; Faschinger, C.; Haller-Schober, E.M.; Walochnik, J.; Aspoeck, H.; Hiti, B.

    2003-01-01

    Microbially contaminated contact lens storage cases are considered to be a predisposing risk factor for Acanthamoeba keratitis. What kind of effect does microwave irradiation have on contact lens cases contaminated with Acanthamoeba cysts and trophozoites? Different types of contact lens cases were contaminated with trophozoites and cysts of three different Acanthamoeba species (A. hatchetti, A. castellanii, A. comandoni) and exposed to microwave irradiation for 3, 5 and 8 minutes respectively. One of the three test series was run with dehydrated cysts. After an irradiation period of 3 minutes under humid conditions cysts and trophozoites of all three strains were completely destroyed. Dehydrated cysts of A. hatchetti and A. castellanii were not killed by irradiation. There were no negative effects of irradiation on the contact lens cases themselves. Acanthamoeba cysts and trophozoites are effectively killed by microwave irradiation on condition that irradiation takes place in humid conditions. This can be easily achieved by filling the contact lens storage cases with tap water. We recommend microwave irradiation as a cheap and save method for the sterilization of contact lens cases in order to avoid a possible Acanthamoeba infection of the eye. (author)

  6. Evaluation of the effectiveness of tea tree oil in treatment of Acanthamoeba infection.

    Science.gov (United States)

    Hadaś, Edward; Derda, Monika; Cholewiński, Marcin

    2017-03-01

    Eye diseases caused by amoebae from the genus Acanthamoeba are usually chronic and severe, and their treatment is prolonged and not very effective. The difficulties associated with therapy have led to attempts at finding alternative treatment methods. Particularly popular is searching for cures among drugs made of plants. However, no substances with total efficacy in treating Acanthamoeba keratitis have been identified.Results of our semi in vivo studies of tea tree oil simulating eyeball infection demonstrated 100% effectiveness in the case of both trophozoites and cysts of amoebae from the genus Acanthamoeba. The action of tea tree oil indicates that this is the first substance with a potential ability to quickly and effectively remove the amoebae from the eye. Tea tree oil has the ability to penetrate tissues, which allows it to destroy amoebae in both the shallow and deep layers of the cornea. The present research into the use of tea tree oil in the therapy of Acanthamoeba infection is the first study of this type in parasitology. It offers tremendous potential for effective treatment of Acanthamoeba keratitis and other diseases caused by these protozoa.

  7. Isolation and genotyping of acanthamoeba strains from soil sources from Jamaica, West Indies.

    Science.gov (United States)

    Todd, Cheridah D; Reyes-Batlle, María; Martín-Navarro, Carmen Ma; Dorta-Gorrín, Alexis; López-Arencibia, Atteneri; Martínez-Carretero, Enrique; Piñero, José E; Valladares, Basilio; Lindo, John F; Lorenzo-Morales, Jacob

    2015-01-01

    Acanthamoeba spp. are opportunistic pathogens that are ubiquitous in nature. Many species of this genus are responsible for a fatal encephalitis and keratitis in humans and other animals. Seventy-two soil samples were collected from the parishes across Jamaica and assessed for the presence of Acanthamoeba spp. Cultivation was carried out on non-nutrient agar plates seeded with heat killed Escherichia coli. PCR and sequencing of the DF3 region were carried out in order to genotype the isolated strains of Acanthamoeba. Thermotolerance and osmotolerance assays were utilized to investigate the pathogenic potential of the Acanthamoeba isolates. Acanthamoeba spp. was isolated from 63.9% of soil samples. Sequencing of the DF3 region of the 18S rDNA resulted in the identification of genotypes T4, T5, and T11. T4 genotype was most frequently isolated. Most isolates were thermotolerant or both thermotolerant and osmotolerant, indicating that they may present the potential to cause disease in humans and other animals. © 2014 The Author(s) Journal of Eukaryotic Microbiology © 2014 International Society of Protistologists.

  8. A multisystemic Acanthamoeba infection in a dog in Tenerife, Canary Islands, Spain.

    Science.gov (United States)

    Valladares, María; Reyes-Batlle, María; Mora-Peces, Inmaculada; Martín-Navarro, Carmen M; López-Arencibia, Atteneri; Dorta-Gorrín, Alexis; Comyn-Afonso, Estefanía; Martínez-Carretero, Enrique; Maciver, Sutherland K; Piñero, José E; Valladares, Basilio; Lorenzo-Morales, Jacob

    2014-10-15

    A 22-month-old male Spanish water dog was hospitalized after its physical examination revealed fever and movement difficulty. After 24h, the dog was found to have a high fever (39.5 °C) and was treated empirically with doxycycline/ciprofloxacin. At 48 h, after submission the fever rose to 41 °C and the animal presented with a stiff neck and dehydration. Peripheral blood and cerebrospinal fluid (CSF) were sampled and trophozoites with an Acanthamoeba-like morphology were observed in the CSF. PCR specific for Acanthamoeba, Naegleria fowleri and Balamuthia mandrillaris were performed and the CSF sample found positive for Acanthamoeba. Lungs, kidney, liver and spleen samples were collected post mortem. All collected organ samples were positive for Acanthamoeba by PCR, thus confirming a multisystemic infection. Water samples taken at a suspected site of infection yielded an almost identical PCR fragment to those of the clinical samples, indicating that this was probably where the infection originated. This is the first report of a fatal case of Acanthamoeba disseminated infection in a dog in Spain. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Potentially pathogenic Acanthamoeba genotype T4 isolated from dental units and emergency combination showers

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    Esteban Castro-Artavia

    Full Text Available BACKGROUND Acanthamoeba is the genus of free-living amoebae that is most frequently isolated in nature. To date, 20 Acanthamoeba genotypes have been described. Genotype T4 is responsible for approximately 90% of encephalitis and keratitis cases. Due to the ubiquitous presence of amoebae, isolation from environmental sources is not uncommon; to determine the clinical importance of an isolation, it is necessary to have evidence of the pathogenic potential of amoebae. OBJECTIVE The aim of this study was to physiologically characterise 8 Acanthamoeba T4 isolates obtained from dental units and emergency combination showers and to determine their pathogenic potential by employing different laboratory techniques. METHODS Eight axenic cultures of Acanthamoeba genotype T4 were used in pathogenic potential assays. Osmotolerance, thermotolerance, determination and characterisation of extracellular proteases and evaluation of cytopathic effects in MDCK cells were performed. FINDINGS All of the isolates were osmotolerant, thermotolerant and had serine proteases from 44-122 kDa. Two isolates had cytopathic effects on the MDCK cell monolayer. MAIN CONCLUSION The presence of Acanthamoeba T4 with pathogenic potential in areas such as those tested in this study reaffirms the need for adequate cleaning and maintenance protocols to reduce the possibility of infection with free-living amoebae.

  10. Pathogenic Acanthamoeba castellanii Secretes the Extracellular Aminopeptidase M20/M25/M40 Family Protein to Target Cells for Phagocytosis by Disruption.

    Science.gov (United States)

    Huang, Jian-Ming; Liao, Chen-Chieh; Kuo, Chung-Ching; Chen, Lih-Ren; Huang, Lynn L H; Shin, Jyh-Wei; Lin, Wei-Chen

    2017-12-18

    Acanthamoeba is free-living protist pathogen capable of causing a blinding keratitis and granulomatous encephalitis. However, the mechanisms of Acanthamoeba pathogenesis are still not clear. Here, our results show that cells co-cultured with pathogenic Acanthamoeba would be spherical and floated, even without contacting the protists. Then, the Acanthamoeba protists would contact and engulf these cells. In order to clarify the contact-independent pathogenesis mechanism in Acanthamoeba , we collected the Acanthamoeba -secreted proteins (Asp) to incubate with cells for identifying the extracellular virulent factors and investigating the cytotoxicity process. The Asps of pathogenic Acanthamoeba express protease activity to reactive Leu amino acid in ECM and induce cell-losing adhesion ability. The M20/M25/M40 superfamily aminopeptidase protein (ACA1_264610), an aminopeptidase be found in Asp, is upregulated after Acanthamoeba and C6 cell co-culturing for 6 h. Pre-treating the Asp with leucine aminopeptidase inhibitor and the specific antibodies of Acanthamoeba M20/M25/M40 superfamily aminopeptidase could reduce the cell damage during Asp and cell co-incubation. These results suggest an important functional role of the Acanthamoeba secreted extracellular aminopeptidases in the Acanthamoeba pathogenesis process. This study provides information regarding clinically pathogenic isolates to target specific molecules and design combined drugs.

  11. Pathogenic Acanthamoeba castellanii Secretes the Extracellular Aminopeptidase M20/M25/M40 Family Protein to Target Cells for Phagocytosis by Disruption

    Directory of Open Access Journals (Sweden)

    Jian-Ming Huang

    2017-12-01

    Full Text Available Acanthamoeba is free-living protist pathogen capable of causing a blinding keratitis and granulomatous encephalitis. However, the mechanisms of Acanthamoeba pathogenesis are still not clear. Here, our results show that cells co-cultured with pathogenic Acanthamoeba would be spherical and floated, even without contacting the protists. Then, the Acanthamoeba protists would contact and engulf these cells. In order to clarify the contact-independent pathogenesis mechanism in Acanthamoeba, we collected the Acanthamoeba-secreted proteins (Asp to incubate with cells for identifying the extracellular virulent factors and investigating the cytotoxicity process. The Asps of pathogenic Acanthamoeba express protease activity to reactive Leu amino acid in ECM and induce cell-losing adhesion ability. The M20/M25/M40 superfamily aminopeptidase protein (ACA1_264610, an aminopeptidase be found in Asp, is upregulated after Acanthamoeba and C6 cell co-culturing for 6 h. Pre-treating the Asp with leucine aminopeptidase inhibitor and the specific antibodies of Acanthamoeba M20/M25/M40 superfamily aminopeptidase could reduce the cell damage during Asp and cell co-incubation. These results suggest an important functional role of the Acanthamoeba secreted extracellular aminopeptidases in the Acanthamoeba pathogenesis process. This study provides information regarding clinically pathogenic isolates to target specific molecules and design combined drugs.

  12. Importancia de algunos medios auxiliares de diagnóstico en la enfermedad inflamatoria pélvica aguda Importance of some diagnostic aids in the acute pelvic inflammatory disease

    Directory of Open Access Journals (Sweden)

    Pastor Villavicencio Crespo

    2008-03-01

    Full Text Available INTRODUCCIÓN. Hoy día la enfermedad inflamatoria pélvica aguda se considera un síndrome clínicamente atribuido al paso ascendente de microorganismos desde la vagina al cérvix, hasta el endometrio y las trompas de Falopio, y que es capaz de diseminarse a las estructuras vecinas. Fueron objetivos de esta publicación conocer el comportamiento de la enfermedad, la eficiencia de algunos medios y procedimientos diagnósticos y el comportamiento de las pruebas hematológicas e identificar los gérmenes más frecuentes para definir la conducta posterior. MÉTODOS. El universo estuvo conformado por 108 mujeres atendidas en el Hospital «Julio Trigo López» a causa de una enfermedad inflamatoria pélvica aguda. Se seleccionó la muestra aleatoriamente y se registraron en una encuesta variables como datos generales y de salud y de la historia ginecoobstétrica. Para el diagnóstico clínico se realizó tacto vaginal, con anestesia o sin ella, punción del saco de Douglas, ultrasonido, laparoscopia, hemograma, leucograma y eritrosedimentación. En todos los casos se utilizó la laparoscopia como prueba comprobatoria. RESULTADOS. La mayoría de las pacientes tenían edades entre los 20 y 25 años. El dolor abdominal (98,1 % y la leucorrea (30,6 % predominaron como sintomatología clínica. Se encontró una alta incidencia de esta enfermedad en mujeres en edad reproductiva, con dos o más embarazos y abortos y el antecedente de dispositivo intrauterino implantado. Además, hubo concordancia diagnóstica entre los resultados aportados por el tacto vaginal y el ultrasonido, al compararlos con la laparoscopia. La prueba menos específica fue el tacto vaginal (20,5 % y los valores predictivos de la prueba positiva más baja también lo aportó el mismo proceder (64,6 %, así como la eritrosedimentación (70 %. Por tanto, después de la laparoscopia, el medio más efectivo fue el ultrasonido (87,5 %. CONCLUSIONES. Se concluyó que la prueba más eficiente

  13. Desarrollo de infección tuberculosa latente y efectos adversos de la isoniazida durante tratamiento con biológico por Enfermedad de Crohn

    Directory of Open Access Journals (Sweden)

    María Alejandra Arriola

    2017-12-01

    Full Text Available Los fármacos anti factor de necrosis tumoral alfa (TNF-a bloquean una de las citoquinas implicadas en la patogénesis de la Enfermedad Inflamatoria intestinal (EII. Su uso se relaciona con aumento de tuberculosis (TB, por lo que el despistaje previo es obligatorio. En la infección tuberculosa latente (ITBL se utiliza isoniazida como quimioprofilaxis, fármaco que no se encuentra libre de reacciones adversas. Se presenta y discute el caso de una paciente con reacción adversa en piel secundaria al uso de isoniazida.

  14. Identification of two genetic markers that distinguish pathogenic and nonpathogenic strains of Acanthamoeba spp.

    Science.gov (United States)

    Howe, D K; Vodkin, M H; Novak, R J; Visvesvara, G; McLaughlin, G L

    1997-01-01

    Species-level identification of Acanthamoeba isolates is difficult and gives little or no indication of the isolate's pathogenicity. We identified two amplification-based genetic markers that were highly correlated with pathogenicity in Acanthamoeba spp. One marker, designed to amplify a 485-bp fragment of the small-subunit ribosomal RNA gene (ssrDNA), was preferentially amplified from the nonpathogenic strains; amplifications from the pathogenic strains yielded anomalous fragments of 650 and 900 bp. A second marker was developed on the basis of the anomalous 650-bp fragment. Primers to this sequence preferentially amplified a noncoding locus (called Ac6) only from the pathogenic strains. These two genetic markers may be useful for identification of pathogenic Acanthamoeba spp. strains.

  15. Effects of magainins on ameba and cyst stages of Acanthamoeba polyphaga.

    Science.gov (United States)

    Schuster, F L; Jacob, L S

    1992-01-01

    Amebic keratitis produced by Acanthamoeba spp. is an increasingly important ocular infection in extended-use contact lens wearers. Problems associated with the infection are compounded by the lack of effective and well-tolerated chemotherapeutic agents. The magainins, a group of naturally occurring and synthetic membrane-active peptide compounds, have been shown to be active in vitro against a clinical isolate of Acanthamoeba polyphaga. Two magainins tested extensively had minimal inhibitory and minimal amebicidal values of 20 and 25 micrograms/ml for magainin MSI-103 and 25 and 40 micrograms/ml for magainin MSI-94, respectively. Both amebastatic and amebicidal activities are enhanced by combining the magainins with silver nitrate (200 micrograms/ml) and/or other marginally effective antimicrobial agents. These combinations have activity against both trophic and cystic stages in the Acanthamoeba life cycle and have promise as antimicrobial agents in the treatment of amebic keratitis. PMID:1416825

  16. Isolation and molecular characterization of Acanthamoeba and Balamuthia mandrillaris from combination shower units in Costa Rica.

    Science.gov (United States)

    Retana-Moreira, Lissette; Abrahams-Sandí, Elizabeth; Cabello-Vílchez, Alfonso Martín; Reyes-Batlle, María; Valladares, Basilio; Martínez-Carretero, Enrique; Piñero, José E; Lorenzo-Morales, Jacob

    2014-11-01

    Free living amoebae (FLA) are ubiquitous protozoa, which may behave as parasites under certain conditions. Four genera are recognized as causal agents of infections in humans and animals: Naegleria, Sappinia, Acanthamoeba and Balamuthia. This work determines the presence of FLA in combination shower units and employs molecular biology for the characterization of isolates. The morphological analysis and partial sequencing of the 18S rDNA gene revealed the presence of Acanthamoeba genotype T4 in 30% of the units sampled. In addition to Acanthamoeba cysts, trophozoites with morphological characteristics similar to Balamuthia were identified. PCR assay using the mitochondrial 16S rRNA gene as a target confirmed the identification of the amoeba as Balamuthia mandrillaris. Up to date, this is the first report of the isolation of B. mandrillaris in Central America and the fifth report worldwide.

  17. Lethal effects of Helianthemum lippii (L.) on Acanthamoeba castellanii cysts in vitro.

    Science.gov (United States)

    Badria, F A; Hetta, M H; Sarhan, Rania M; Ezz El-Din, M H

    2014-06-01

    Acanthamoeba spp. commonly cause Acanthamoeba keratitis which is typically associated with the wear of contact lenses. Therefore, finding an economic, efficient, and safe therapy of natural origin is of outmost importance. This study examined the in vitro lethal potential of ethyl acetate and methanol extracts of Helianthemum lippii (L.) (sun roses) against Acanthamoeba castellanii cysts isolated from patients with amoebic keratitis. Both extracts proved to be potent as regard to their lethal effects on A. castellanii cysts with comparable results to chlorhexidine. The ethyl acetate was more promising with cumulative lethality. It showed a highly significant lethal percentage along the duration of treatment. The analysis of the more potent ethyl acetate extract revealed the presence of 2.96 mg/100 g of total phenolics, 0.289 mg/100 ml of total flavonoids and 37 mg/100 mg of total tannins which highlighted their phytomedicinal role.

  18. Degradation of immunoglobulins, protease inhibitors, and interleukin-1 by a secretory proteinase of Acanthamoeba castellanii

    Science.gov (United States)

    Na, Byoung-Kuk; Cho, Jong-Hwa; Song, Chul-Yong; Kim, Tong-Soo

    2002-01-01

    The effect of a secretory proteinase from the pathogenic amoebae Acanthamoeba castellanii on host's defense-oriented or regulatory proteins such as immunoglobulins, interleukin-1, and protease inhibitors was investigated. The enzyme was found to degrade secretory immunoglobulin A (sIgA), IgG, and IgM. It also degraded interleukin-1α (IL-1α) and IL-1β. Its activity was not inhibited by endogenous protease inhibitors, such as α2-macroglobulin, α1-trypsin inhibitor, and α2-antiplasmin. Furthermore, the enzyme rapidly degraded those endogenous protease inhibitors as well. The degradation of host's defense-oriented or regulatory proteins by the Acanthamoeba proteinase suggested that the enzyme might be an important virulence factor in the pathogenesis of Acanthamoeba infection. PMID:12073735

  19. Isolation and identification of Acanthamoeba species from natural water sources in the northeastern part of Thailand.

    Science.gov (United States)

    Thammaratana, Thani; Laummaunwai, Porntip; Boonmars, Thidarut

    2016-04-01

    Acanthamoeba are found in the environment, particularly in water, all over the world. The genus is currently classified into 20 different genotypes, T1-T20. In this study, 63 natural water samples from 11 provinces in northeast Thailand were collected and cultured on non-nutrient agar plates. Positive samples by culture were subsequently analyzed by molecular methods. The identification of Acanthamoeba was based on morphological features and molecular techniques using PCR and DNA sequencing. The results showed that 10 samples out of 63 were positive (15.9 %). Phylogenetic analysis revealed that seven samples were T4, one sample was similar to T3, and the other two samples were similar to T5. This is the first report demonstrating the contamination of Acanthamoeba species in natural water sources in northeast Thailand.

  20. Occurrence and genetic characterisation of Acanthamoeba spp. from environmental and domestic water sources in Queen Elizabeth Protected Area, Uganda.

    Science.gov (United States)

    Sente, Celsus; Erume, Joseph; Naigaga, Irene; Magambo, Phillip Kimuda; Ochwo, Sylvester; Mulindwa, Julius; Namara, Benigna Gabriella; Kato, Charles Drago; Sebyatika, George; Muwonge, Kevin; Ocaido, Michael

    2016-03-03

    Acanthamoeba is an emerging potentially pathogenic amoeba that has been receiving increasing attention worldwide as a reservoir and potential vector for the transmission of pathogenic bacteria. It is also associated with brain cell damage, keratitis and skin irritation in humans. Its effects are more severe in immunocompromised individuals. This study provides for the first time in Uganda, information on the prevalence and genotypes of Acanthamoeba in environmental and domestic (tap) water. A total of 324 environmental and 84 tap water samples were collected between November 2013 and September 2014. The samples were centrifuged, cultured (Non-Nutrient agar seeded with gram-negative bacteria) and observed under a microscope. After confirmation of Acanthamoeba, genomic DNA was extracted for PCR assays by chemical lysis and purification with phenol/chloroform/isoamyl alcohol. Samples that showed the strongest positive bands (400-600 bp) were subjected to cycle sequencing. Among environmental and tap water samples, 107 (33 %) and 36 (42.9 %) tested positive for Acanthamoeba spp., respectively. Prevalence of Acanthamoeba from specific environmental locations was as follows; Kazinga channel banks (60.7 %), Fish landing sites (50 %), River Kyambura (39.6 %) and Kazinga mid channel (5.3 %). There was a significant difference (p = 0.001) in the prevalence of Acanthamoeba between sampling sites. The mean (Mean ± SE) occurrence of the organism was higher in Kazinga channel banks (3.44 ± 0.49) and Fish landing sites (3.08 ± 0.53). Correlation between in situ parameters and Acanthamoeba was insignificant except for the Dissolved Oxygen (mg/ML) which was negatively correlated (r = -0.231, p = 0.001) to Acanthamoeba. Six distinct partial Acanthamoeba T-genotype groups T1, T2, T4, T5, T6 and T11 were obtained. Ultimately, Acanthamoeba spp., Acanthamoeba hatchetti and Acanthamoeba polyphaga were isolated in the current study. There was a high prevalence of

  1. A one-step multiplex PCR for acanthamoeba keratitis diagnosis and quality samples control.

    Science.gov (United States)

    Maubon, Danièle; Dubosson, Muriel; Chiquet, Christophe; Yera, Hélène; Brenier-Pinchart, Marie-Pierre; Cornet, Muriel; Savy, Olivier; Renard, Elisabeth; Pelloux, Hervé

    2012-05-14

    As the number of cases of Acanthamoeba spp. keratitis (AK) is constantly growing, new diagnostic tools are needed to confirm and guide ophthalmologists in this clinically problematic diagnosis. Molecular diagnosis is particularly well adapted, although only a few real-time PCR techniques have been described recently. The aim of this study was to develop a new PCR technique for the diagnosis of AK by combining the detection of Acanthamoeba DNA with human DNA, thus allowing an accurate interpretation of the PCR result. Different DNA extraction procedures were compared to ensure an optimized amplification of one Acanthamoeba genome. The analytical parameters of this new multiplex Acanthamoeba beta-globin PCR (MAB-PCR) were evaluated. Fourteen eye drops were tested as potential PCR inhibitors. A prospective series of 28 corneal scrapings was subjected to MAB-PCR. The best extraction procedure associated thermal-shock pretreatment followed by a manual extraction procedure. The MAB-PCR parameters displayed excellent specificity and sensitivity, with a detection of 0.02 genome of Acanthamoeba. No eye drops were total PCR inhibitors. Of 28 corneal scrapings, 18 were considered true negatives. Seven could not be interpreted because of insufficient scraping material. Three were considered true positives: every patient progressed favorably on specific and reliable treatment. The MAB-PCR is a new tool to diagnose AK. It allows rapid diagnosis and prompt treatment of this probably underestimated etiology of infectious keratitis. This optimized real-time PCR outperforms the gold standard for Acanthamoeba keratitis diagnosis and it allows a concomitant evaluation of the quality of the corneal scraping, which is necessary for a precise interpretation of the results.

  2. Pathogenic strains of Acanthamoeba are recognized by TLR4 and initiated inflammatory responses in the cornea.

    Science.gov (United States)

    Alizadeh, Hassan; Tripathi, Trivendra; Abdi, Mahshid; Smith, Ashley Dawn

    2014-01-01

    Free-living amoebae of the Acanthamoeba species are the causative agent of Acanthamoeba keratitis (AK), a sight-threatening corneal infection that causes severe pain and a characteristic ring-shaped corneal infiltrate. Innate immune responses play an important role in resistance against AK. The aim of this study is to determine if Toll-like receptors (TLRs) on corneal epithelial cells are activated by Acanthamoeba, leading to initiation of inflammatory responses in the cornea. Human corneal epithelial (HCE) cells constitutively expressed TLR1, TLR2, TLR3, TLR4, and TLR9 mRNA, and A. castellanii upregulated TLR4 transcription. Expression of TLR1, TLR2, TLR3, and TLR9 was unchanged when HCE cells were exposed to A. castellanii. IL-8 mRNA expression was upregulated in HCE cells exposed to A. castellanii. A. castellanii and lipopolysaccharide (LPS) induced significant IL-8 production by HCE cells as measured by ELISA. The percentage of total cells positive for TLR4 was higher in A. castellanii stimulated HCE cells compared to unstimulated HCE cells. A. castellanii induced upregulation of IL-8 in TLR4 expressing human embryonic kidney (HEK)-293 cells, but not TLR3 expressing HEK-293 cells. TLR4 neutralizing antibody inhibited A. castellanii-induced IL-8 by HCE and HEK-293 cells. Clinical strains but not soil strains of Acanthamoeba activated TLR4 expression in Chinese hamster corneas in vivo and in vitro. Clinical isolates but not soil isolates of Acanthamoeba induced significant (PAcanthamoeba activate TLR4 and induce production of CXCL2 in the Chinese hamster model of AK. TLR4 may be a potential target in the development of novel treatment strategies in Acanthamoeba and other microbial infections that activate TLR4 in corneal cells.

  3. Evaluation of the immunodiagnostic potential of a recombinant surface protein domain from Acanthamoeba castellanii.

    Science.gov (United States)

    Sánchez, Alemao G Carpinteyro; Virginio, Veridiana Gomes; Maschio, Vinicius José; Ferreira, Henrique Bunselmeyer; Rott, Marilise Brittes

    2016-10-01

    Acanthamoeba spp. are free-living protists widely distributed in environment, able to cause keratitis, encephalitis and skin lesions in humans and animals. Acanthamoeba spp. exist in two forms: an infective trophozoite and a dormant cyst. Several factors contribute to the pathogenesis of Acanthamoeba spp. The parasite adhesion to the host cell is the primary step for infection and is mediated by a mannose binding-protein, expressed in the surface and considered the main pathogenicity factor in Acanthamoeba spp. So far, there was no evidence of another surface protein of Acanthamoeba spp. relevant for host invasion or infection by these organisms. The aims of this study were to identify and characterize an Acanthamoeba castellanii surface protein and to evaluate its diagnostic potential. In silico predictions of surface proteins allowed to identify the A. castellanii calreticulin as a possible surface antigen. The coding sequence of a predicted extracellular domain of A. castellanii calreticulin was cloned by in vivo homologous recombination and the recombinant polypeptide (AcCRT29-130) was produced. Its immunodiagnostic potential was assessed in a recombinant antigen-based ELISA with sera from experimentally infected rats that developed keratitis and encephalitis, and sera from patients with encephalitis. The AcCRT29-130 was significantly more recognized by sera from encephalitis infected rats in comparison with the non-infected controls. Human sera from encephalitis patients, however presented no significant response. These results showed the AcCRT29-130 potential for A. castellanii infection immunodiagnosis in animals, with further studies being required for assessment of its use for human infections.

  4. Effects of lactoferrin on the viability and the encystment of Acanthamoeba trophozoites.

    Science.gov (United States)

    Tomita, Shinichi; Suzuki, Chie; Wada, Hitomi; Nomachi, Miya; Imayasu, Masaki; Araki-Sasaki, Kaoru

    2017-02-01

    Lactoferrin (LF) is an iron-binding basic glycoprotein that has an antimicrobial effect against certain microbes. The purpose of this study is to evaluate the amoebicidal effect of bovine milk LF (bLF) against Acanthamoeba clinical-isolate trophozoites, which cause severe keratitis. Most of the risk factor for Acanthamoeba keratitis is from wearing soft contact lenses (SCLs). Acanthamoeba trophozoites were incubated in bovine LF (bLF) solution, and the ratios of viability and encystment were determined with microscopic analysis of cyst formation. The amoebicidal effect of bLF was assessed by Trypan blue assay. The ratios of viable cells in the presence of iron-free bLF (apo-bLF), native-bLF, and iron-saturated bLF (Fe-bLF) at the concentration of 10 μmol/L for 60 min were 7.7% ± 4.6%, 80.7% ± 10.1%, and 97.3% ± 1.5%, respectively. Apo-bLF showed potent amoebicidal effect against Acanthamoeba trophozoites, but Fe-bLF did not have this effect. After treating with apo-bLF, most dead cells were nonglobular forms of trophozoites but not cystic forms. Encystment of Acanthamoeba was assessed by the sarkosyl-calcofluor white assay. The encystment ratios treated with 0.5% propylene glycol (positive control) and 10 μmol/L apo-bLF for 24 h were 96.12% ± 10.6% and 0.47% ± 0.5%, respectively. These results suggest that the amoebicidal effect of apo-bLF without encystment might lead to the prevention of contamination of Acanthamoeba in SCL stock cases.

  5. Pathogenic Strains of Acanthamoeba Are Recognized by TLR4 and Initiated Inflammatory Responses in the Cornea

    Science.gov (United States)

    Alizadeh, Hassan; Tripathi, Trivendra; Abdi, Mahshid; Smith, Ashley Dawn

    2014-01-01

    Free-living amoebae of the Acanthamoeba species are the causative agent of Acanthamoeba keratitis (AK), a sight-threatening corneal infection that causes severe pain and a characteristic ring-shaped corneal infiltrate. Innate immune responses play an important role in resistance against AK. The aim of this study is to determine if Toll-like receptors (TLRs) on corneal epithelial cells are activated by Acanthamoeba, leading to initiation of inflammatory responses in the cornea. Human corneal epithelial (HCE) cells constitutively expressed TLR1, TLR2, TLR3, TLR4, and TLR9 mRNA, and A. castellanii upregulated TLR4 transcription. Expression of TLR1, TLR2, TLR3, and TLR9 was unchanged when HCE cells were exposed to A. castellanii. IL-8 mRNA expression was upregulated in HCE cells exposed to A. castellanii. A. castellanii and lipopolysaccharide (LPS) induced significant IL-8 production by HCE cells as measured by ELISA. The percentage of total cells positive for TLR4 was higher in A. castellanii stimulated HCE cells compared to unstimulated HCE cells. A. castellanii induced upregulation of IL-8 in TLR4 expressing human embryonic kidney (HEK)-293 cells, but not TLR3 expressing HEK-293 cells. TLR4 neutralizing antibody inhibited A. castellanii-induced IL-8 by HCE and HEK-293 cells. Clinical strains but not soil strains of Acanthamoeba activated TLR4 expression in Chinese hamster corneas in vivo and in vitro. Clinical isolates but not soil isolates of Acanthamoeba induced significant (PAcanthamoeba activate TLR4 and induce production of CXCL2 in the Chinese hamster model of AK. TLR4 may be a potential target in the development of novel treatment strategies in Acanthamoeba and other microbial infections that activate TLR4 in corneal cells. PMID:24633052

  6. Acanthamoeba containing endosymbiotic chlamydia isolated from hospital environments and its potential role in inflammatory exacerbation.

    Science.gov (United States)

    Fukumoto, Tatsuya; Matsuo, Junji; Okubo, Torahiko; Nakamura, Shinji; Miyamoto, Kentaro; Oka, Kentaro; Takahashi, Motomichi; Akizawa, Kouji; Shibuya, Hitoshi; Shimizu, Chikara; Yamaguchi, Hiroyuki

    2016-12-15

    Environmental chlamydiae belonging to the Parachlamydiaceae are obligate intracellular bacteria that infect Acanthamoeba, a free-living amoeba, and are a risk for hospital-acquired pneumonia. However, whether amoebae harboring environmental chlamydiae actually survive in hospital environments is unknown. We therefore isolated living amoebae with symbiotic chlamydiae from hospital environments. One hundred smear samples were collected from Hokkaido University Hospital, Sapporo, Japan; 50 in winter (February to March, 2012) and 50 in summer (August, 2012), and used for the study. Acanthamoebae were isolated from the smear samples, and endosymbiotic chlamydial traits were assessed by infectivity, cytokine induction, and draft genomic analysis. From these, 23 amoebae were enriched on agar plates spread with heat-killed Escherichia coli. Amoeba prevalence was greater in the summer-collected samples (15/30, 50%) than those of the winter season (8/30, 26.7%), possibly indicating a seasonal variation (p = 0.096). Morphological assessment of cysts revealed 21 amoebae (21/23, 91%) to be Acanthamoeba, and cultures in PYG medium were established for 11 of these amoebae. Three amoebae contained environmental chlamydiae; however, only one amoeba (Acanthamoeba T4) with an environmental chlamydia (Protochlamydia W-9) was shown the infectious ability to Acanthamoeba C3 (reference amoebae). While Protochlamydia W-9 could infect C3 amoeba, it failed to replicate in immortal human epithelial, although exposure of HEp-2 cells to living bacteria induced the proinflammatory cytokine, IL-8. Comparative genome analysis with KEGG revealed similar genomic features compared with other Protochlamydia genomes (UWE25 and R18), except for a lack of genes encoding the type IV secretion system. Interestingly, resistance genes associated with several antibiotics and toxic compounds were identified. These findings are the first demonstration of the distribution in a hospital of a living

  7. Disseminated acanthamoeba infection in patients with AIDS: case reports and review.

    Science.gov (United States)

    Sison, J P; Kemper, C A; Loveless, M; McShane, D; Visvesvara, G S; Deresinski, S C

    1995-05-01

    Acanthamoeba infection has been described as an opportunistic infection in persons with AIDS. We report two cases of patients with AIDS and acanthamoeba infection and review the manifestations of this protozoan infection in patients infected with human immunodeficiency virus. The diagnosis of this infection requires a high index of suspicion because the clinical and histologic manifestations may be confused with those of disseminated fungal or algal disease. Clinicians and laboratory personnel should be aware of this potentially fatal condition so that appropriate diagnostic studies can be performed and treatment can be urgently administered. Early initiation of therapy may alter the clinical outcome of the disease.

  8. Killing of diverse eye pathogens (Acanthamoeba spp., Fusarium solani, and Chlamydia trachomatis with alcohols.

    Directory of Open Access Journals (Sweden)

    Yousuf Aqeel

    2017-02-01

    Full Text Available Blindness is caused by eye pathogens that include a free-living protist (Acanthamoeba castellanii, A. byersi, and/or other Acanthamoeba spp., a fungus (Fusarium solani, and a bacterium (Chlamydia trachomatis. Hand-eye contact is likely a contributor to the spread of these pathogens, and so hand washing with soap and water or alcohol-based hand sanitizers (when water is not available might reduce their transmission. Recently we showed that ethanol and isopropanol in concentrations present in hand sanitizers kill walled cysts of Giardia and Entamoeba, causes of diarrhea and dysentery, respectively. The goal here was to determine whether these alcohols might kill infectious forms of representative eye pathogens (trophozoites and cysts of Acanthamoeba, conidia of F. solani, or elementary bodies of C. trachomatis.We found that treatment with 63% ethanol or 63% isopropanol kills >99% of Acanthamoeba trophozoites after 30 sec exposure, as shown by labeling with propidium iodide (PI and failure to grow in culture. In contrast, Acanthamoeba cysts, which contain cellulose fibers in their wall, are relatively more resistant to these alcohols, particularly isopropanol. Depending upon the strain tested, 80 to 99% of Acanthamoeba cysts were killed by 63% ethanol after 2 min and 95 to 99% were killed by 80% ethanol after 30 sec, as shown by PI labeling and reduced rates of excystation in vitro. Both ethanol and isopropanol (63% for 30 sec kill >99% of F. solani conidia, which have a wall of chitin and glucan fibrils, as demonstrated by PI labeling and colony counts on nutrient agar plates. Both ethanol and isopropanol (63% for 60 sec inactivate 96 to 99% of elementary bodies of C. trachomatis, which have a wall of lipopolysaccharide but lack peptidoglycan, as measured by quantitative cultures to calculate inclusion forming units.In summary, alcohols kill infectious forms of Acanthamoeba, F. solani, and C. trachomatis, although longer times and higher ethanol

  9. Strategies for the prevention of contact lens-related Acanthamoeba keratitis: a review.

    Science.gov (United States)

    Carnt, Nicole; Stapleton, Fiona

    2016-03-01

    Acanthamoeba keratitis is a severe, often sight threatening, corneal infection which in Western countries is predominantly seen in daily wear of contact lenses. This review aims to summarise the pathobiology and epidemiology of contact lens-related Acanthamoeba keratitis, and to present strategies for prevention, particularly with respect to modifiable risk factors in contact lens wear. The virulence of Acanthamoeba and resistance to treatment in keratitis appears to be linked with the production of a low molecular weight protease MIP133 by the organism, in response to binding to corneal epithelial cells through a mannose binding protein, and to the ability of the organism to convert from the trophozoite to the resistant cyst form. Recent epidemiological studies in contact lens relate disease have confirmed the link between solution topping up and Acanthamoeba keratitis and have reinforced the importance of avoidance of tap water, either as part of the care for the contact lens or storage case, handling lenses with wet hands or showering while wearing lenses. In the most recent analysis from the USA, there were no strong effects for solution type, water source or water disinfection process. Wearer age, lens wear time and history to appear to be linked with Acanthamoeba keratitis. Daily disposable contact lens use would be expected to reduce the prevalence of Acanthamoeba disease although this is unproven. While Acanthamoeba keratitis remains challenging to diagnose and manage, strategies to limit the disease severity in contact lens wearers should include attention to recently identified risk factors, particularly those related to water contact. Public health awareness measures, the use of daily disposable contact lenses, a better understanding of the contribution of the host immunity and the development of standardised methods for culture of amoeba and testing of contact lens care systems against Acanthamoeba in the licensing process may be of value. Alternative

  10. Development of a Practical Complete-Kill Assay to Evaluate Anti-Acanthamoeba Drugs

    Science.gov (United States)

    Kowalski, Regis P.; Abdel Aziz, Salwa; Romanowski, Eric G.; Shanks, RobertM. Q.; Nau, Amy C.; Raju, Leela V.

    2015-01-01

    IMPORTANCE Acanthamoeba keratitis is a debilitating eye disease that requires effective topical drugtherapy. Currently, there is no standard in vitro test to evaluate anti-Acanthamoeba drugs. OBJECTIVE To develop a practical in vitro complete-kill assay to assess anti-Acanthamoeba drugs. DESIGN AND SETTING Isolates of Acanthamoeba strains (n = 15) evaluated in a clinical laboratory. An in vitro laboratory assay was created to determine whether polyhexamethylene biguanide, 0.02%, chlorhexidine digluconate, 0.02%, hexamidine diisethioonate, 0.1%, and voriconazole, 1.0%, were effective in completely killing 15 different isolates of Acanthamoeba at time points of 24, 48, and 72 hours in comparison with a saline control. Each 0.5-mL volume of drug was inoculated with 0.1 mL of Acanthamoeba cysts (range, 1–3×106/mL) (determined with a hemacytometer) and allowed to incubate at 30°C. At the time points listed, 0.05 mL from each treatment group was inoculated onto nonnutrient agar overlaid with Enterobacter aerogenes. The plates were microscopically examined for growth 1 and 2 weeks after inoculation. At 2 weeks, all plates were subcultured onto a fresh medium. At another 7 days, the growth in subculture at each time point was graded "1" for growth and "0" for no growth. MAIN OUTCOMES AND MEASURES The cumulative grades of 3 time points (range, 0–3) for each drug and isolate were nonparametrically compared to determine differences in growth between the drugs. The "kill" incidence rates over the 3 time points were also compared. RESULTS In vitro testing determined that antiacanthamoebal efficacy (determined by the median growth grade and the kill incidence rate) was more prominent for hexamidine diisethioonate (median growth grade, 0.0; kill incidence rate, 93% [14 of 15 isolates]) and polyhexamethylene biguanide (median growth grade, 0.0; kill incidence rate, 80% [12 of 15 isolates]) than for chlorhexidine digluconate (median growth grade, 1.0; kill incidence rate, 40

  11. In vitro destruction of nerve cell cultures by Acanthamoeba spp.: a transmission and scanning electron microscopy study.

    Science.gov (United States)

    Pettit, D A; Williamson, J; Cabral, G A; Marciano-Cabral, F

    1996-10-01

    Trophozoites of 4 species of Acanthamoeba were cytopathic for cultured rat B103 neuroblastoma cells. Cytopathogenicity was evaluated by a chromium release assay and by transmission and scanning electron microscopy. Acanthamoeba culbertsoni, Acanthamoeba castellanii, and Acanthamoeba polyphaga destroyed B103 target cells at 37 C as evidenced by the release of radiolabel. Acanthamoeba astronyxis did not produce cytopathology at 37 C but destroyed nerve cells at 25 C. Transmission and scanning electron microscopy of cocultures maintained at different time periods revealed that all species of Acanthamoeba exhibited long cylindrical structures, termed digipodia, which made contact with target cells. Following this effector cell-target cell contact, membrane blebbing on the nerve cells was observed. These events were followed either by lysis of target nerve cells or ingestion of the target cells via food-cups and their subsequent channeling into intracytoplasmic food vacuoles. Use of the TUNEL (TdT-mediated dUTP nick end labeling) technique indicated that approximately 40% of B103 cells incubated with A. culbertsoni, 20% of B103 cells cocultured with A. castellanii or with A. polyphaga, and less than 1% of B103 cells incubated with A. astronyxis at 37 C were apoptotic after 24 hr of coculture. Studies using electron microscopy indicated that Acanthamoeba trophozoites destroyed nerve cells both by cytolysis and by ingestion of whole nerve cells via food-cups.

  12. Discrimination between Clinically Relevant and Nonrelevant Acanthamoeba Strains Isolated from Contact Lens- Wearing Keratitis Patients in Austria

    Science.gov (United States)

    Walochnik, J.; Haller-Schober, E.-M.; Kölli, H.; Picher, O.; Obwaller, A.; Aspöck, H.

    2000-01-01

    Eighteen cases of Acanthamoeba-associated keratitis among contact lens wearers seen at the Department of Ophthalmology, Karl-Franzens-University, Graz, Austria, between 1996 and 1999 are reviewed. The amoebae were proven to be the causative agents in three patients. The aim of our study was to discriminate between clinically relevant and nonrelevant isolates and to assess the relatedness of the isolates to published strains. Altogether, 20 strains of free-living amoebae, including 15 Acanthamoeba strains, 3 Vahlkampfia strains, and 2 Hartmannella strains, were isolated from clinical specimens. The virulent Acanthamoeba strains were identified as A. polyphaga and two strains of A. hatchetti. To our knowledge this is the first determination of keratitis-causing Acanthamoeba strains in Austria. Clinically relevant isolates differed markedly from nonrelevant isolates with respect to their physiological properties. 18S ribosomal DNA sequence types were determined for the three physiologically most-divergent strains including one of the keratitis-causing strains. This highly virulent strain exhibited sequence type T6, a sequence type not previously associated with keratitis. Sequence data indicate that Acanthamoeba strains causing keratitis as well as nonpathogenic strains of Acanthamoeba in Austria are most closely related to published strains from other parts of the world. Moreover, the results of our study support the assumption that pathogenicity in Acanthamoeba is a distinct capability of certain strains and not dependent on appropriate conditions for the establishment of an infection. PMID:11060047

  13. Temperature-induced membrane-lipid adaptation in Acanthamoeba castellanii.

    Science.gov (United States)

    Jones, A L; Hann, A C; Harwood, J L; Lloyd, D

    1993-01-01

    A method has been developed for the separation of the major membrane fractions of Acanthamoeba castellanii after growth at different temperatures. The acyl-lipid compositions of individual membrane fractions, microsomal membranes, plasma membrane and mitochondria were analysed after a shift in culture temperature from 30 degrees C to 15 degrees C. The major change in lipid composition observed was an alteration in the relative proportions of oleate and linoleate. This reciprocal change was seen in all the membrane fractions, but occurred most rapidly in the phosphatidylcholine of the microsomal fraction. Thus, there appears to be a rapid induction of delta 12-desaturase activity in A. castellanii after a downward shift in growth temperature. Changes were also seen in the proportions of the n-6 C20 fatty acids, with a decrease in the proportions of icosadienoate and increases of icosatrienoate and arachidonate. However, unlike the alteration in oleate/linoleate ratios, this change was not seen in all the individual lipids of each membrane fraction. Images Figure 1 PMID:8439295

  14. Characterization of actin filament severing by actophorin from Acanthamoeba castellanii

    Science.gov (United States)

    1991-01-01

    Actophorin is an abundant 15-kD actinbinding protein from Acanthamoeba that is thought to form a nonpolymerizable complex with actin monomers and also to reduce the viscosity of polymerized actin by severing filaments (Cooper et al., 1986. J. Biol. Chem. 261:477-485). Homologous proteins have been identified in sea urchin, chicken, and mammalian tissues. Chemical crosslinking produces a 1:1 covalent complex of actin and actophorin. Actophorin and profilin compete for crosslinking to actin monomers. The influence of actophorin on the steady-state actin polymer concentration gave a Kd of 0.2 microM for the complex of actophorin with actin monomers. Several new lines of evidence, including assays for actin filament ends by elongation rate and depolymerization rate, show that actophorin severs actin filaments both at steady state and during spontaneous polymerization. This is confirmed by direct observation in the light microscope and by showing that the effects of actophorin on the low shear viscosity of polymerized actin cannot be explained by monomer sequestration. The severing activity of actophorin is strongly inhibited by stoichiometric concentrations of phalloidin or millimolar concentrations of inorganic phosphate. PMID:1757465

  15. Growth of Legionella pneumophila in Acanthamoeba castellanii enhances invasion.

    Science.gov (United States)

    Cirillo, J D; Falkow, S; Tompkins, L S

    1994-01-01

    Legionella pneumophila is considered to be a facultative intracellular parasite. Therefore, the ability of these bacteria to enter, i.e., invade, eukaryotic cells is expected to be a key pathogenic determinant. We compared the invasive ability of bacteria grown under standard laboratory conditions with that of bacteria grown in Acanthamoeba castellanii, one of the protozoan species that serves as a natural host for L. pneumophila in the environment. Amoeba-grown L. pneumophila cells were found to be at least 100-fold more invasive for epithelial cells and 10-fold more invasive for macrophages and A. castellanii than were L. pneumophila cells grown on agar. Comparison of agar- and amoeba-grown L. pneumophila cells by light and electron microscopy demonstrated dramatic differences in the morphology and structure of the bacteria. Analyses of protein expression in the two strains of bacteria suggest that these phenotypic differences may be due to the expression of new proteins in amoeba-grown L. pneumophila cells. In addition, the amoeba-grown bacteria were found to enter macrophages via coiling phagocytosis at a higher frequency than agar-grown bacteria did. Replication of L. pneumophila in protozoans present in domestic water supplies may be necessary to produce bacteria that are competent to enter mammalian cells and produce human disease. Images PMID:8039895

  16. Survival of taylorellae in the environmental amoeba Acanthamoeba castellanii.

    Science.gov (United States)

    Allombert, Julie; Vianney, Anne; Laugier, Claire; Petry, Sandrine; Hébert, Laurent

    2014-03-19

    Taylorella equigenitalis is the causative agent of contagious equine metritis, a sexually-transmitted infection of Equidae characterised in infected mares by abundant mucopurulent vaginal discharge and a variable degree of vaginitis, cervicitis or endometritis, usually resulting in temporary infertility. The second species of the Taylorella genus, Taylorella asinigenitalis, is considered non-pathogenic, although mares experimentally infected with this bacterium can develop clinical signs of endometritis. To date, little is understood about the basic molecular virulence and persistence mechanisms employed by the Taylorella species. To clarify these points, we investigated whether the host-pathogen interaction model Acanthamoeba castellanii was a suitable model for studying taylorellae. We herein demonstrate that both species of the Taylorella genus are internalised by a mechanism involving the phagocytic capacity of the amoeba and are able to survive for at least one week inside the amoeba. During this one-week incubation period, taylorellae concentrations remain strikingly constant and no overt toxicity to amoeba cells was observed. This study provides the first evidence of the capacity of taylorellae to survive in a natural environment other than the mammalian genital tract, and shows that the alternative infection model, A. castellanii, constitutes a relevant alternative system to assess host-pathogen interactions of taylorellae. The survival of taylorellae inside the potential environmental reservoir A. castellanii brings new insight, fostering a broader understanding of taylorellae biology and its potential natural ecological niche.

  17. [Characteristic appearance of early-stage Acanthamoeba keratitis].

    Science.gov (United States)

    Sasaki, Miho; Sotozono, Chie; Chihara, Hidemi; Ueta, Mayumi; Inatomi, Tsutomu; Yokoi, Norihiko; Shiota, Tsunezou; Kinoshita, Shigeru

    2010-12-01

    To clarify the characteristic appearances of early-stage Acanthamoeba keratitis (AK) and to investigate the effects of topical steroids on those appearances. This study involved 25 eyes of 24 patients diagnosed as early-stage AK at Kyoto Prefectural University of Medicine between October 2002 and June 2008. All patients were contact lens wearers, and 23 patients (96%) were referred from other hospitals. Clinical findings in the medical records of all patients were analyzed retrospectively. Radial keratoneuritis was observed in 20 of 25 eyes (80%), and pseudodendritic lesions were observed in 15 eyes (60%). Only 1 eye (4%) showed neither of these two findings. Of the 10 eyes treated with topical steroids until the first presentation at our hospital, 6 eyes manifested radial keratoneuritis and/or pseudodendritic lesions after the discontinuation of that treatment. The visual prognosis was good in both groups, with or without topical steroid treatment. We found that radial keratoneuritis and pseudodendritic lesions are characteristic appearances of early-stage AK, and that topical steroid treatment might mask these characteristic findings.

  18. Acanthamoeba polyphaga-enhanced growth of Mycobacterium smegmatis.

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    Otmane Lamrabet

    Full Text Available BACKGROUND: Mycobacterium smegmatis is a rapidly-growing mycobacterium causing rare opportunistic infections in human patients. It is present in soil and water environments where free-living amoeba also reside, but data regarding M. smegmatis-amoeba relationships have been contradictory from mycobacteria destruction to mycobacteria survival. METHODOLOGY/PRINCIPAL FINDINGS: Using optic and electron microscopy and culture-based microbial enumeration we investigated the ability of M. smegmatis mc(2 155, M. smegmatis ATCC 19420(T and M. smegmatis ATCC 27204 organisms to survive into Acanthamoeba polyphaga trophozoites and cysts. We observed that M. smegmatis mycobacteria penetrated and survived in A. polyphaga trophozoites over five-day co-culture resulting in amoeba lysis and the release of viable M. smegmatis mycobacteria without amoebal cyst formation. We further observed that amoeba-co-culture, and lysed amoeba and supernatant and pellet, significantly increased five-day growth of the three tested M. smegmatis strains, including a four-fold increase in intra-amoebal growth. CONCLUSIONS/SIGNIFICANCE: Amoebal co-culture increases the growth of M. smegmatis resulting in amoeba killing by replicating M. smegmatis mycobacteria. This amoeba-M. smegmatis co-culture system illustrates an unusual paradigm in the mycobacteria-amoeba interactions as mycobacteria have been mainly regarded as amoeba-resistant organisms. Using these model organisms, this co-culture system could be used as a simple and rapid model to probe mycobacterial factors implicated in the intracellular growth of mycobacteria.

  19. Legionella pneumophila prevents proliferation of its natural host Acanthamoeba castellanii

    Science.gov (United States)

    Mengue, Luce; Régnacq, Matthieu; Aucher, Willy; Portier, Emilie; Héchard, Yann; Samba-Louaka, Ascel

    2016-01-01

    Legionella pneumophila is a ubiquitous, pathogenic, Gram-negative bacterium responsible for legionellosis. Like many other amoeba-resistant microorganisms, L. pneumophila resists host clearance and multiplies inside the cell. Through its Dot/Icm type IV secretion system, the bacterium injects more than three hundred effectors that modulate host cell physiology in order to promote its own intracellular replication. Here we report that L. pneumophila prevents proliferation of its natural host Acanthamoeba castellanii. Infected amoebae could not undergo DNA replication and no cell division was observed. The Dot/Icm secretion system was necessary for L. pneumophila to prevent the eukaryotic proliferation. The absence of proliferation was associated with altered amoebal morphology and with a decrease of mRNA transcript levels of CDC2b, a putative regulator of the A. castellanii cell cycle. Complementation of CDC28-deficient Saccharomyces cerevisiae by the CDC2b cDNA was sufficient to restore proliferation of CDC28-deficient S. cerevisiae and suggests for the first time that CDC2b from A. castellanii could be functional and a bona fide cyclin-dependent kinase. Hence, our results reveal that L. pneumophila impairs proliferation of A. castellanii and this effect could involve the cell cycle protein CDC2b. PMID:27805070

  20. Acanthamoeba and Dictyostelium as Cellular Models for Legionella Infection

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    A. Leoni Swart

    2018-03-01

    Full Text Available Environmental bacteria of the genus Legionella naturally parasitize free-living amoebae. Upon inhalation of bacteria-laden aerosols, the opportunistic pathogens grow intracellularly in alveolar macrophages and can cause a life-threatening pneumonia termed Legionnaires' disease. Intracellular replication in amoebae and macrophages takes place in a unique membrane-bound compartment, the Legionella-containing vacuole (LCV. LCV formation requires the bacterial Icm/Dot type IV secretion system, which translocates literally hundreds of “effector” proteins into host cells, where they modulate crucial cellular processes for the pathogen's benefit. The mechanism of LCV formation appears to be evolutionarily conserved, and therefore, amoebae are not only ecologically significant niches for Legionella spp., but also useful cellular models for eukaryotic phagocytes. In particular, Acanthamoeba castellanii and Dictyostelium discoideum emerged over the last years as versatile and powerful models. Using genetic, biochemical and cell biological approaches, molecular interactions between amoebae and Legionella pneumophila have recently been investigated in detail with a focus on the role of phosphoinositide lipids, small and large GTPases, autophagy components and the retromer complex, as well as on bacterial effectors targeting these host factors.

  1. External NAD(P)H dehydrogenases in Acanthamoeba castellanii mitochondria.

    Science.gov (United States)

    Antos-Krzeminska, Nina; Jarmuszkiewicz, Wieslawa

    2014-09-01

    The mitochondrial respiratory chain of plants and some fungi contains multiple rotenone-insensitive NAD(P)H dehydrogenases, of which at least two are located on the outer surface of the inner membrane (i.e., external NADH and external NADPH dehydrogenases). Annotated sequences of the putative alternative NAD(P)H dehydrogenases of the protozoan Acanthamoeba castellanii demonstrated similarity to plant and fungal sequences. We also studied activity of these dehydrogenases in isolated A. castellanii mitochondria. External NADPH oxidation was observed for the first time in protist mitochondria. The coupling parameters were similar for external NADH oxidation and external NADPH oxidation, indicating similar efficiencies of ATP synthesis. Both external NADH oxidation and external NADPH oxidation had an optimal pH of 6.8 independent of relevant ubiquinol-oxidizing pathways, the cytochrome pathway or a GMP-stimulated alternative oxidase. The maximal oxidizing activity with external NADH was almost double that with external NADPH. However, a lower Michaelis constant (K(M)) value for external NADPH oxidation was observed compared to that for external NADH oxidation. Stimulation by Ca(2+) was approximately 10 times higher for external NADPH oxidation, while NADH dehydrogenase(s) appeared to be slightly dependent on Ca(2+). Our results indicate that external NAD(P)H dehydrogenases similar to those in plant and fungal mitochondria function in mitochondria of A. castellanii. Copyright © 2014 Elsevier GmbH. All rights reserved.

  2. Paralelismo clínico e imagenológico por resonancia magnética de los procesos inflamatorios de la médula espinal

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    Rómel Sarmiento Ducóngers

    2017-05-01

    Full Text Available Con el objetivo de identificar las características clínicas y por resonancia magnética de las lesiones inflamatorias de la médula espinal, se realizó un estudio observacional descriptivo transversal, de 56 pacientes, atendidos en los hospitales provinciales de Santiago de Cuba “Dr. Juan Bruno Zayas Alfonso” y “Dr. Saturnino Lora”, durante el periodo comprendido entre enero de 2014 hasta junio de 2015. Las características clínicas de las lesiones inflamatorias de la médula espinal fueron la cuarta década de la vida y el sexo masculino (60,7%, con síntomas predominantes como el dolor, la paresia y la parestesia. Existió predominio de las mielitis compresiva e inflamatoria. Al explorar el grado de concordancia entre la clínica y el informe de la resonancia magnética se obtuvo un índice de Kappa de 0,35. El diagnóstico imagenológico más relevante fue la mielitis compresiva en correspondencia con el diagnóstico clínico, no obstante la investigación permitió determinar que la concordancia entre la clínica y el diagnóstico imagenológico por resonancia magnética en los estudios realizados a estos pacientes en el periodo de estudio fue débil.

  3. Valor del estudio celular del esputo en el seguimiento de las enfermedades inflamatorias de la vía aérea

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    Juan Antonio Mazzei

    2012-08-01

    Full Text Available El análisis celular del esputo, espontáneo u obtenido mediante la técnica de esputo inducido, se ha transformado en una herramienta ampliamente difundida para la evaluación y orientación del tratamiento de las enfermedades inflamatorias de la vía aérea, principalmente asma, enfermedad pulmonar obstructiva crónica y bronquitis eosinofílica. Se han aportado evidencias sobre la utilidad de la técnica del esputo inducido, validada y estandarizada, para ser empleada en pacientes con dificultades para expectorar. Numerosas investigaciones dieron cuenta de la efectividad de basar las decisiones terapéuticas en el componente inflamatorio de la vía aérea mediante el recuento de células en el esputo. Varios estudios mostraron que, en pacientes con asma el análisis celular de esputo guía en la determinación de estrategias para disminuir las exacerbaciones y para mejorar la función pulmonar, aun en pacientes con asma grave, para disminuir el remodelamiento; también se ha descrito su utilidad en pacientes con EPOC, para la disminución de las exacerbaciones.

  4. Response of first attack of inflammatory bowel disease requiring hospital admission to steroid therapy Respuesta al tratamiento esteroideo del primer brote de enfermedad inflamatoria intestinal que requiere ingreso hospitalario

    Directory of Open Access Journals (Sweden)

    M. Abu-Suboh Abadía

    2004-08-01

    Full Text Available Introduction: corticoid administration is the usual treatment of Crohn' disease (CD and ulcerative colitis (UC attacks. How-ever, information available on response rates and their predictive factors is scarce. Objective: to establish response to steroidal treatment in an homogeneous group of patients with CD or UC during their first admission to hospital. Methods: restrospective analysis of 86 patients who received systemic steroidal treatment for a severe flare-up during their first hospital admission between 1995 and 2000. Patients were treated per protocol with fluid therapy, absolute diet, IV 6-methyl-prednisolone 1 mg/kg/day, and enoxaparin at prophylactic doses. Clinical response at 30 days was considered good in case of complete remission, and poor in case of partial or absent remission. Univariate and multivariate analyses according to non-parametric statistics were performed for sociodemographic and biologic variables. Results: 45 patients with CD and 41 with UC were included. Good response rates were 64.4% for CD and 60.9% for UC. The univariate analysis showed that patients with good response have shorter evolution times and fewer previous flare-ups (p Introducción: la administración de corticoides constituye el tratamiento habitual de los brotes de enfermedad de Crohn (EC y colitis ulcerosa (CU. Sin embargo, existe poca información sobre las tasas de respuesta y los factores que puedan predecirla. Objetivo: determinar la respuesta al tratamiento esteroideo en un grupo homogéneo de pacientes de EC y CU que ingresan por primera vez en el hospital. Métodos: análisis retrospectivo de 86 pacientes que en su primer ingreso hospitalario recibieron tratamiento esteroideo sistémico por brote grave de EC o CU entre 1995 y 2000. Fueron tratados de forma protocolizada con sueroterapia, dieta absoluta, 6-metil-prednisolona 1 mg/kg/día IV y enoxaparina a dosis profilácticas. Se ha considerado la respuesta clínica a los 30 días como

  5. Chemical composition and anti-Acanthamoeba activity of Melaleuca styphelioides essential oil.

    Science.gov (United States)

    Albouchi, Ferdaous; Sifaoui, Ines; Reyes-Batlle, Maria; López-Arencibia, Atteneri; Piñero, José E; Lorenzo-Morales, Jacob; Abderrabba, Manef

    2017-12-01

    Acanthamoeba infections cause serious humans diseases, such as amoebic keratitis and granulomatous amoebic encephalitis. Melaleuca essential oil has been reported to be effective in treating bacterial and fungal infections. However, the anti-parasitic effects of this essential oil are not well studied. In the present study, we first characterized the composition of the essential oil, extracted from the Tunisian Melaleuca styphelioides leaves, and then tested its effect on the Acanthamoeba castellanii Neff. Gas chromatography-mass spectrometry (GC-MS) analysis revealed that the major common compounds were Caryophyllene oxide (23.42%), Spathulenol (20.5%), Isoaromadendrene epoxide (7.45%), Ledol (5.98%), α-Pinene (3.82%), Isopinocarveol (2.18%). Our data also showed that M. styphelioides essential oil inhibited the growth of Acanthamoeba with an IC 50 value of 69.03 ± 9.17 μg/ml. This work suggests M. styphelioides essential oil as a potential anti amoeba drug. Nevertheless, further studies are still needed to further verify the cytotoxicity of the studied oil on human macrophages and check its applicability to treat Acanthamoeba infections in vivo. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Keratoneuritis is not pathognomonic of Acanthamoeba keratitis: a case report of Pseudomonas keratitis.

    Science.gov (United States)

    Roels, Dimitri; De Craene, Sophie; Kestelyn, Philippe

    2017-02-01

    The presence of keratoneuritis in a radial pattern is considered to be a virtually pathognomonic sign of Acanthamoeba keratitis. We report a case of a massive keratoneuritis as a presenting sign in Pseudomonas keratitis in a contact lens wearer, thereby further challenging this concept.

  7. Differences in isoenzyme patterns of axenically and monoxenically grown Acanthamoeba and Hartmannella.

    Science.gov (United States)

    Weekers, P H; De Jonckheere, J F

    1997-03-01

    Axenically and monoxenically grown Acanthamoeba castellanii, Acanthamoeba polyphaga and different isolates of Hartmannella vermiformis strains were examined by polyacrylamide isoelectric focusing in the pH range 3-10. Isoenzyme patterns of acid phosphatase (AP), propionyl esterase (PE), malate dehydrogenase (MDH), alcohol dehydrogenase (ADH), glucose phosphate isomerase (GPI) and phosphoglucomutase (PGM) were compared. Zymograms were used to reveal differences in typical isoenzyme patterns between axenically and monoxenically grown amoebae and to compare axenically grown A. castellanii, A. polyphaga and H. vermiformis. Comparison of zymograms for AP, PE and MDH between axenically grown Acanthamoeba and Hartmannella strains revealed different isoenzyme patterns. Acanthamoeba showed strong bands for ADH and extremely weak bands for GPI and PGM, while Hartmannella lacked ADH but possessed bands for GPI and PGM. Comparison of zymograms from axenically and monoxenically grown amoebae revealed a lower intensity and even lack of typical isoenzyme bands in lysates from monoxenic cultures. The observed changes in typical isoenzyme patterns induced by the bacterial substrate can influence the correct isoenzymatic typing of different strains in clinical and phylogenetic studies.

  8. Differential adherence of Acanthamoeba to contact lenses: effects of material characteristics.

    Science.gov (United States)

    Seal, D V; Bennett, E S; McFadyen, A K; Todd, E; Tomlinson, A

    1995-01-01

    Acanthamoeba-associated keratitis occurs most often in contact lens wearers. The contact lens material may affect its ability to act as a mechanical vector, permitting transfer of viable amoebae from the storage case to the corneal surface. The purpose of this study was to investigate the effects of ionicity and water content on the comparative quantitative adherence of Acanthamoeba trophozoites and cysts to new, unworn hydrogel contact lenses and rigid gas-permeable contact lens materials. Sixteen quarter segments of each of 8 types of unworn hydrogel lenses representative of FDA groups 1 to 4 were exposed to freshly prepared cultures of either trophozoites or cysts of A. castellanii or A. polyphaga for 1.5 h, and then washed. Three types of rigid lens button were similarly exposed to A. castellanii trophozoites or cysts. Adherent trophozoites and cysts were then enumerated. All hydrogel lenses showed binding of both trophozoites and cysts, with the former predominating in every case. It was primarily the ionic nature of a lens surface and secondly its water content that was associated with increased quantitative adherence of Acanthamoeba. Neither form of the amoebae bound to any of the hard lens buttons. Greater relative potential exists for contamination of ionic and high-water content hydrogels by Acanthamoeba. This combination may influence mechanical transmission of the protozoon to the corneal surface. Adherence to hard lenses (as buttons) did not occur if a postincubation wash step was performed.

  9. In vitro drug susceptibility of Acanthamoeba castellani to chloroquine, ivermectin and fungizon.

    Science.gov (United States)

    Rain, A N; Radzan, T; Sajiri, S; Mak, J W

    1996-06-01

    In vitro sensitivity of Acanthamoeba castellani was tested to three drugs: Chloroquine, ivermectin and fungizone (amphotericin B). Sensitivity was demonstrated to the latter two compounds but not to chloroquine. Thus ivermectin and amphotericin B show promise as therapeutic agents against this parasite.

  10. Corneal virulence, cytopathic effect on human keratocytes and genetic characterization of Acanthamoeba.

    Science.gov (United States)

    Badenoch, P R; Adams, M; Coster, D J

    1995-02-01

    Acanthamoeba keratitis is a sight-threatening complication of corneal trauma or contact lens wear. Although the majority of corneal isolates of Acanthamoeba belong to Group II in the Pussard-Pons classification based on cyst morphology, they have been placed in at least six species and their genetic relatedness is uncertain. The aim of this study was to determine the virulence of, and the relationship among, strains derived from the cornea, the nasal mucosa, and other environmental sources. To assess virulence, 10(4) trophozoites of each strain were incubated with monolayers of human corneal fibroblasts. By day 7, 12 of 29 strains tested had induced significant cytopathic changes. In addition, inocula of 10(4) cysts or trophozoites with 10(6) Corynebacterium xerosis were injected into the corneas of Porton rats; 11 amoebic strains induced infection within 7 days. The correlation between the virulence of trophozoites in vitro and in vivo was 86%. Using allozyme electrophoresis, 23 Acanthamoeba strains clustered into 5 major phylogenic divisions. Three divisions contained one or more strains that were virulent in the rat cornea. Virulent Pussard-Pons Group II strains clustered tightly to a fixed allelic difference of 13.6%. The eight corneal isolates clustered to 33%, dividing into three lineages. Five avirulent nasal isolates were strongly differentiated from other Group II strains. The results were not in accord with species designations based primarily on morphological criteria. These data suggest that particular subsets of Acanthamoeba strains are virulent in the human cornea.

  11. Amebicidal activity of plant extracts from Southeast Asia on Acanthamoeba spp.

    Science.gov (United States)

    Chu, D M; Miles, H; Toney, D; Ngyuen, C; Marciano-Cabral, F

    1998-09-01

    The effect of 100 polar and 100 nonpolar plant extract materials obtained from Southeast Asia were evaluated for amebicidal activity in vitro against three species of Acanthamoeba. A. culbertsoni, A. castellanii, and A. polyphaga, the causative agents of granulomatous amebic encephalitis and amebic keratitis, were studied in vitro to determine whether the plant extracts exhibited amebicidal activity or induced encystment of the amebae. Of the 200 plant extracts tested, extracts obtained from three plants (Ipomoea sp., Kaempferia galanga, and Cananga odorata) were amebicidal for all three species of Acanthamoeba and a fourth extract prepared from Gastrochilus panduratum was lytic for A. polyphaga and growth-inhibitory for A. castellanii and A. culbertsoni. Three plant extracts induced encystment of all three species of Acanthamoeba. Select plant extracts were tested as well for tumoricidal activity against B103 neuroblastoma cells. Some plant extracts that exhibited tumoricidal activity for B103 cells were not amebicidal for Acanthamoeba spp. Additionally, the polar and nonpolar extracts that exhibited amebicidal activity were also tested for activity against primary murine peritoneal macrophage cultures. Plant extracts that demonstrated tumoricidal or amebicidal activity were not lytic for normal macrophage cultures.

  12. Molecular Characterization of Pathogenic Acanthamoeba Isolated from Drinking and Recreational water in East Azerbaijan, Northwest Iran.

    Science.gov (United States)

    Behniafar, Hamed; Niyyati, Maryam; Lasjerdi, Zohreh

    2015-01-01

    Acanthamoeba- related infections, such as amoebic keratitis and granulomatous amoebic encephalitis, can develop in high-risk population through contaminated water sources. Thus, surveying water resources, particularly those available for human use, is of the utmost importance. In the present study, 67 water samples were collected from water resources in East Azerbaijan, a province in northwestern Iran. Samples were cultured on enriched non-nutrient agar plates, and sequencing-based approaches were used for genotyping. The pathogenic potential of the isolates was determined using thermo- and osmo-tolerance tests. Acanthamoeba were detected in 17 (25.4%) of the 67 collected samples. Sequencing analysis revealed that the isolates belonged to the T3 (23.52%), mixed T3/T4 (5.88%), T4 (58.82%), T5 (5.88%), and T13 (5.88%) genotypes. Through thermo- and osmo-tolerance tests, 88.23% of isolates were resistant to 37 °C, 40 °C temperature, and 0.5 M and 1 M osmolarity; thus, these isolates had the potential for pathogenicity. These findings point toa serious public health concern in the studied region. This study is the first to report Acanthamoeba isolated from drinking and recreational water sources in East Azerbaijan and Acanthamoeba T13 isolated from tap water in Iran.

  13. Molecular Identification and Sequencing of Mannose Binding Protein (MBP Gene of Acanthamoeba palestinensis

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    M Rezaeian

    2010-02-01

    Full Text Available "nBackground: Acanthamoeba keratitis develops by pathogenic Acanthamoeba such as A. pal­es­tinen­sis. Indeed this species is one of the known causative agents of amoebic keratitis in Iran. Mannose Binding Protein (MBP is the main pathogenicity factors for developing this sight threatening disease. We aimed to characterize MBP gene in pathogenic Acanthamoeba isolates such as A. palestinensis."nMethods: This experimental research was performed in the School of Public Health, Tehran University of Medical Sciences, Tehran, Iran during 2007-2008.  A. palestinensis was grown on 2% non-nutrient agar overlaid with Escherichia coli. DNA extraction was performed using phenol-chloroform method. PCR reaction and amplification were done using specific primer pairs of MBP. The amplified fragment were purified and sequenced. Finally, the obtained fragment was deposited in the gene data bank."nResults: A 900 bp PCR-product was recovered after PCR reaction. Sequence analysis of the purified PCR product revealed a gene with 943 nucleotides. Homology analysis of the ob­tained sequence showed 81% similarity with the available MBP gene in the gene data bank. The fragment was deposited in the gene data bank under accession number EU678895"nConclusion: MBP is known as the most important factor in Acanthamoeba pathogenesis cas­cade. Therefore, characterization of this gene can aid in developing better therapeutic agents and even immunization of high-risk people.

  14. Effect of combined chlorhexidine gluconate and neosporin on experimental keratitis with two pathogenic strains of Acanthamoeba.

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    Polat, Zubeyde Akin; Vural, Ayse

    2012-05-01

    Acanthamoeba keratitis (AK) is a painful, sight-threatening, and difficult-to-treat corneal infection caused by the ubiquitous free-living amoebae Acanthamoeba species. The aim of the present study was to compare the severity of keratitis, caused by Acanthamoeba hatchetii and Acanthamoeba castellanii infections, and to assess the therapeutic effects of combined chlorhexidine (CHX) and Neosporin® treatment in rats. The rats were first divided into two groups, in which the eyes of the animals were infected with A. hatchetii or A. castellanii trophozoites. On day 5, all corneas were examined in order to determine the degree of infection (grade 0 to 3), and animals were divided into two new groups, treatment and infected control groups. The treatment was continued for 28 days, followed by excision and histological evaluation of the corneas. In conclusion, the clinical picture progressed more rapidly and severely in eyes infected by A. castellanii, while it was non-invasive and slower to progress with A. hatchetii. Moreover, eyes infected by A. hatchetii responded quicker and more positively to therapy, consistent with its clinical course, while a longer recovery was seen with A. castellanii. Histological examinations revealed the presence of A. castellanii and A. hatchetii trophozoites in the stroma of eyes of the treatment and control groups. As a result, our findings suggest that a combination of Neosporin with lower doses of CHX may be beneficial to treat patients with early diagnosis of AK.

  15. Associated factors, diagnosis and management of Acanthamoeba keratitis in a referral Center in Southern China.

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    Zhong, Jing; Li, Xingyi; Deng, Yuqing; Chen, Ling; Zhou, Shiyou; Huang, Weilan; Lin, Shiqi; Yuan, Jin

    2017-10-02

    To analyse the associated factors, diagnosis, clinical manifestations and therapeutic effects of Acanthamoeba keratitis at a tertiary ophthalmic centre in Southern China. A retrospective clinical study was performed in fifteen patients who were admitted to Zhongshan Ophthalmic Centre (ZOC) from January 2004 to December 2014. The patients' pathogenesis-associated factors were analysed, and preoperative diagnoses were determined using corneal scraping cultures and/or confocal microscopy followed. All diagnoses were confirmed by postoperative pathological examinations. At follow-up, best-corrected visual acuity (BCVA), the recurrence rate and graft transparency were evaluated to assess therapeutic effects. The main pathogenic factors observed in the fifteen patients were a history of injury or a foreign body entering the eyes (12 cases). In all, Acanthamoeba keratitis was preoperatively diagnosed in 5 cases using corneal scraping cultures or confocal microscopy. Ocular symptoms included redness, photophobia, tearing, and blurred vision. Penetrating keratoplasty was performed in thirteen patients, and postoperative pathological examinations were performed to confirm these diagnoses. The logarithm of the minimum angle of resolution (logMAR) of visual acuity was significantly improved after keratoplasty (p Acanthamoeba keratitis in southern China. Corneal scraping combined with confocal microscopy was helpful for achieving a correct diagnosis. Early keratoplasty combined with amoebicidal therapy is an effective treatment strategy in Acanthamoeba keratitis.

  16. In vitro effect of Acanthospermum australe (Asteraceae extracts on Acanthamoeba polyphaga trophozoites

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    LC Castro

    2013-01-01

    Full Text Available Acanthamoeba is a free-living protozoan widely distributed in the environment, occurring in vegetative trophozoite and resistance cyst stages during its life cycle. It constitutes an etiological agent of Acanthamoeba keratitis, a disease that may cause severe ocular inflammation and blindness. New drugs can be developed from molecules found in plants and thus help in its difficult treatment. Acanthospermum australe (Asteraceae, a plant used in folk medicine, had its effect tested on Acanthamoeba polyphaga. Aqueous and ethanolic extracts of A. austral were obtained from aerial parts for infusion and static maceration, respectively. Concentrations of 10, 5, 2.5, 1.25 and 0.625 mg/ml of the extract were tested against Acanthamoeba polyphaga trophozoites. The cytotoxic effect of the extracts was tested in mammalian cells using the 3-(4, 5-dimethylthiazol-2-yl-2, 5-diphenyltetrazolium bromide (MTT assay. RESULTS: The 10 mg/ml concentration of ethanolic extract was lethal to 100% of the A. polyphaga trophozoites in 24 h and both extracts presented cytotoxic effect against mammalian cells. These findings suggest that the A. austral ethanolic extract may have compounds with relevance to the development of new amoebicidal drugs.

  17. Genotyping of potentially pathogenic Acanthamoeba strains isolated from nasal swabs of healthy individuals in Peru.

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    Cabello-Vílchez, Alfonso Martín; Martín-Navarro, Carmen María; López-Arencibia, Atteneri; Reyes-Batlle, María; González, Ana C; Guerra, Humberto; Gotuzzo, Eduardo; Valladares, Basilio; Piñero, José E; Lorenzo-Morales, Jacob

    2014-02-01

    Free Living Amoebae (FLA) of Acanthamoeba genus are widely distributed in the environment and can be found in the air, soil and water; and have also been isolated from air-conditioning units. In humans, they are causative agents of a sight-threating infection of the cornea, Acanthamoeba keratitis (AK) and a fatal infection of the central nervous system known as Granulomatous Amoebic Encephalitis (GAE). In this study, a survey was conducted in order to determine the presence and pathogenic potential of free-living amoebae of Acanthamoeba genus in nasal swabs from individuals in two regions of Peru. Identification of isolates was based on cyst morphology and PCR-sequencing of the Diagnostic Fragment 3 to identify strains at the genotype level. The pathogenic potential of the isolates was also assayed using temperature and osmotolerance assays and extracellular proteases zymograms. The obtained results revealed that all isolated strains exhibited pathogenic potential. After sequencing the highly variable DF3 (Diagnostic Fragment 3) region in the 18S rRNA gene as previously described, genotype T4 was found to be the most common one in the samples included in this study but also genotype T15 was identified. To the best of our knowledge, this is the first study on the characterization of Acanthamoeba strains at the genotype level and the first report of genotype T4 and T15 in Peru. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Essential Role for an M17 Leucine Aminopeptidase in Encystation of Acanthamoeba castellanii.

    Science.gov (United States)

    Lee, Yu-Ran; Na, Byoung-Kuk; Moon, Eun-Kyung; Song, Su-Min; Joo, So-Young; Kong, Hyun-Hee; Goo, Youn-Kyoung; Chung, Dong-Il; Hong, Yeonchul

    2015-01-01

    Encystation of Acanthamoeba leads to the formation of resilient cysts from vegetative trophozoites. This process is essential for parasite survival under unfavorable conditions such as starvation, low temperatures, and exposure to biocides. During encystation, a massive turnover of intracellular components occurs, and a large number of organelles and proteins are degraded by proteases. Previous studies with specific protease inhibitors have shown that cysteine and serine proteases are involved in encystation of Acanthamoeba, but little is known about the role of metalloproteases in this process. Here, we have biochemically characterized an M17 leucine aminopeptidase of Acanthamoeba castellanii (AcLAP) and analyzed its functional involvement in encystation of the parasite. Recombinant AcLAP shared biochemical properties such as optimal pH, requirement of divalent metal ions for activity, substrate specificity for Leu, and inhibition profile by aminopeptidase inhibitors and metal chelators with other characterized M17 family LAPs. AcLAP was highly expressed at a late stage of encystation and mainly localized in the cytoplasm of A. castellanii. Knockdown of AcLAP using small interfering RNA induced a decrease of LAP activity during encystation, a reduction of mature cyst formation, and the formation of abnormal cyst walls. In summary, these results indicate that AcLAP is a typical M17 family enzyme that plays an essential role during encystation of Acanthamoeba.

  19. Cytotoxic effect of organic solvents and surfactant agents on Acanthamoeba castellanii cysts.

    Science.gov (United States)

    Ezz Eldin, Hayam Mohamed; Sarhan, Rania Mohamed

    2014-05-01

    Acanthamoeba castellanii is a protozoan parasite that may cause sight-threatening keratitis in some individuals. Its eradication is difficult because the trophozoites encyst making organisms highly resistant to anti-amoebic drugs. To test new anti-Acanthamoeba agents, usually having low water solubility, organic solvents and surfactant agents should be used. Therefore, the lethal effect of different concentrations of the solvents acetone, methanol, ethanol, and DMSO and surfactant agents Tween 20, Tween 80, and Triton X-100 was tested. The minimal inhibitory concentrations (MIC) were determined against Acanthamoeba cysts. Results of the present study showed that the MIC for ethanol, methanol, acetone and DMSO was 25, 12.5, 12.5, and 10%, respectively and for Tween 20, Tween 80, and Triton X-100 was 0.25, 0.06, and 0.03%, respectively. There was no significant inhibitory effect on the multiplication of Acanthamoeba cysts as compared to parasite control when using the concentrations 3.12% for ethanol, 1.6% for methanol and acetone, 1.25% for DMSO, and 0.016% for Tween 20. On the other hand, both Tween 80 and Triton X-100 showed highly significant difference in comparison to parasite control almost among all the range of concentrations used in this study, and both showed lethal effect of 19 and 27.2%, respectively at their least concentration.

  20. Essential Role for an M17 Leucine Aminopeptidase in Encystation of Acanthamoeba castellanii.

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    Yu-Ran Lee

    Full Text Available Encystation of Acanthamoeba leads to the formation of resilient cysts from vegetative trophozoites. This process is essential for parasite survival under unfavorable conditions such as starvation, low temperatures, and exposure to biocides. During encystation, a massive turnover of intracellular components occurs, and a large number of organelles and proteins are degraded by proteases. Previous studies with specific protease inhibitors have shown that cysteine and serine proteases are involved in encystation of Acanthamoeba, but little is known about the role of metalloproteases in this process. Here, we have biochemically characterized an M17 leucine aminopeptidase of Acanthamoeba castellanii (AcLAP and analyzed its functional involvement in encystation of the parasite. Recombinant AcLAP shared biochemical properties such as optimal pH, requirement of divalent metal ions for activity, substrate specificity for Leu, and inhibition profile by aminopeptidase inhibitors and metal chelators with other characterized M17 family LAPs. AcLAP was highly expressed at a late stage of encystation and mainly localized in the cytoplasm of A. castellanii. Knockdown of AcLAP using small interfering RNA induced a decrease of LAP activity during encystation, a reduction of mature cyst formation, and the formation of abnormal cyst walls. In summary, these results indicate that AcLAP is a typical M17 family enzyme that plays an essential role during encystation of Acanthamoeba.

  1. Acanthamoeba castellanii: A new high-throughput method for drug screening in vitro.

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    Ortega-Rivas, Antonio; Padrón, José M; Valladares, Basilio; Elsheikha, Hany M

    2016-12-01

    Despite significant public health impact, there is no specific antiprotozoal therapy for prevention and treatment of Acanthamoeba castellanii infection. There is a need for new and efficient anti-Acanthamoeba drugs that are less toxic and can reduce treatment duration and frequency of administration. In this context a new, rapid and sensitive assay is required for high-throughput activity testing and screening of new therapeutic compounds. A colorimetric assay based on sulforhodamine B (SRB) staining has been developed for anti-Acanthamoeba drug susceptibility testing and adapted to a 96-well microtiter plate format. Under these conditions chlorhexidine was tested to validate the assay using two clinical strains of A. castellanii (Neff strain, T4 genotype [IC 50 4.68±0.6μM] and T3 genotype [IC 50 5.69±0.9μM]). These results were in good agreement with those obtained by the conventional Alamar Blue assay, OCR cytotoxicity assay and manual cell counting method. Our new assay offers an inexpensive and reliable method, which complements current assays by enhancing high-throughput anti-Acanthamoeba drug screening capabilities. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Efficacy of Korean Multipurpose Contact Lens Disinfecting Solutions againstAcanthamoeba castellanii.

    Science.gov (United States)

    Moon, Eun-Kyung; Park, Hye-Ryun; Quan, Fu-Shi; Kong, Hyun-Hee

    2016-12-01

    Acanthamoeba keratitis has been increasing in recent years. Main risk factors are contact lens wear and their cleaning solutions. Most contact lens wearers use multipurpose disinfecting solutions (MPDS) for cleansing and disinfecting microorganisms because of its convenience. We determined amoebicidal effects of MPDS made in Korea and their cytotoxicity on human corneal epithelium cells. Fifteen commercial MPDS (A to O) were tested for their amoebicidal effects on Acanthamoeba castellanii trophozoites and cysts by using a most probable number (MPN) technique. Among them, 7 kinds of MPDS showed little or no amoebicidal effects for 24 hr exposure. Solutions A, B, G, H, L, and O showed positive amoebicidal effects, and solutions M and N killed almost all trophozoites and cysts after 24 hr exposure. However, 50%-N solution showed 56% cytotoxicity on human corneal epithelial cells within 4 hr exposure, and 50%-O solution also showed 62% cytotoxicity on human cells within 4 hr exposure. Solution A did not show any cytotoxicity on human cells. These results revealed that most MPDS made in Korea were ineffective to kill Acanthamoeba . The solutions having amoebicidal activity also showed high levels of cytotoxicity on human corneal epithelial cells. New formulations for improved MPDS that are amoebicidal but safe for host cells are needed to prevent Acanthamoeba keratitis.

  3. Comparison of UVA- and UVA/riboflavin-induced growth inhibition of Acanthamoeba castellanii.

    Science.gov (United States)

    Makdoumi, Karim; Bäckman, Anders; Mortensen, Jes; Magnuson, Anders; Crafoord, Sven

    2013-02-01

    To investigate whether ultraviolet light (UVA) at 365 nm can inhibit/eliminate Acanthamoeba growth and if riboflavin would potentiate such an association. Acanthamoeba castellanii in a fluid medium with a concentration of approximately 1.7 × 10(4) protozoa/ml were prepared with (0.01 %) and without riboflavin. Exposure of UVA (dose 5.475 J/cm(2)) took place twice, with each illumination period followed by culturing of 10 μl in peptone yeast-extract glucose (PYG) medium for 7 days. Every suspension prepared had a non-exposed control solution. Determination of Acanthamoeba was conducted daily, by count in Burker chamber days 4 through 7 after exposure. Statistical analysis was done by repeated-measurement ANOVA and post-hoc analysis for unpaired samples. The exposure of ultraviolet light resulted in an inhibited growth of Acanthamoeba compared to the non-exposed solutions, with a statistically significant reduction over time (p = 0.0003). The addition of riboflavin did not amplify the effect, and there were no tendencies for an interaction effect between UVA and riboflavin. The antiprotozoal effect of the UVA wavelength, utilized in CXL, is solely mediated by ultraviolet light, and riboflavin does not seem to amplify the antimicrobial efficacy.

  4. Isolation and identification of Acanthamoeba spp. from thermal swimming pools and spas in Southern Brazil.

    Science.gov (United States)

    Fabres, Laura Fuhrich; Rosa Dos Santos, Sayonara Peixoto; Benitez, Lisianne Brittes; Rott, Marilise Brittes

    2016-03-01

    Free-living amoebae (FLA) are widely distributed in soil and water. A few number of them are implicated in human disease: Acanthamoeba spp., Naegleria fowleri, Balamuthia mandrillaris and Sappinia diploidea. Species of Acanthamoeba can cause keratitis and brain infections. In this study, 72 water samples were taken from both hot tubs and thermal swimming pools in the city of Porto Alegre, RS, Brazil, to determine the presence of Acanthamoeba in the water as well as perform the phenotypic and genotypic characterization of the isolates. The identification of the isolates was based on the cysts morphology and PCR amplification using genus-specific oligonucleotides. When the isolates were submitted to PCR reaction only 8 were confirmed as belonging to the genus Acanthamoeba. The sequences analysis when compared to the sequences in the GenBank, showed genotype distribution in group T3 (12,5%), T5 (12,5%), T4 (25%) and T15 (50%). The results of this study confirmed the presence of potentially pathogenic isolates of free living amoebae in hot swimming pool and spas which can present risks to human health.

  5. Impression Cytology in Eyes with Clinical and Confocal Scan Features of Acanthamoeba Keratitis

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    Mozhgan Rezaei Kanavi

    2013-01-01

    Full Text Available Purpose: To report impression cytology findings in specimens obtained from eyes with clinical and confocal microscopic features of Acanthamoeba keratitis (AK. Methods: In this interventional case series, impression cytology was obtained from corneas of patients with clinical and confocal microscopic features indicative of AK. Specimens were stained with Periodic acid-Schiff/Papanicolaou (PAS/PAP and examined for the presence of PAS-reactive Acanthamoeba cysts and/or hyperchromatic pear-shaped trophozoites. All specimens were then decolorized and re-stained with calcofluor white (CFW for the presence of chemofluorescent cysts. Results: Fifty-six eyes of 50 patients with mean age of 25.5±9.3 (range, 17 to 78 years were evaluated. Forty-one (82% cases were female and 51 (91.1% eyes had history of contact lens wear. PAS-reactive Acanthamoeba cysts and/or hyperchromatic pear-shaped trophozoites were identified in 53 eyes (94.6%, 2 of which demonstrated only trophozoitelike structures. CFW staining was able to reveal the presence of chemofluorescent cysts in all 51 specimens (91.1% in which cysts had been demonstrated with PAS/PAP staining. Trophozoites were not detected with CFW due to background staining of the cellulose acetate strip used for impression cytology. Conclusion: Corneal impression cytology, stained with PAS/PAP or with CFW, successfully detects Acanthamoeba and can be employed for early noninvasive diagnosis of AK.

  6. Acanthamoeba misidentification and multiple labels: redefining genotypes T16, T19, and T20 and proposal for Acanthamoeba micheli sp. nov. (genotype T19).

    Science.gov (United States)

    Corsaro, Daniele; Walochnik, Julia; Köhsler, Martina; Rott, Marilise B

    2015-07-01

    Acanthamoeba species are ubiquitous amoebae able to cause important infections in humans and other vertebrates. The full/near-full sequences (>2000 bp) of the small subunit ribosomal RNA gene (SSU rDNA or 18S rDNA) are used to cluster Acanthamoeba as genotypes, labeled T1 to T20. Genotype T15 remains an exception, being described only partially on a 1500-bp fragment. Strains are thus usually identified based on their 18S identity matches with reference strains, often using shorter (Acanthamoeba micheli sp. nov., for this strain. Furthermore, partial molecular phylogenies were performed to show that several other misassigned T16 partial sequences belong to a new genotype. This latter includes also misassigned T4 partial sequences, only recently available as full sequences and labeled as T20. We thus reassign these partial sequences to the genotype T20. Longer sequences, ideally at least 90 % of the total gene length, should be obtained from strains to ensure reliable diagnostic and phylogenetic results.

  7. Patient characteristics, diagnosis, and treatment of non-contact lens related Acanthamoeba keratitis.

    Science.gov (United States)

    Sharma, S; Garg, P; Rao, G N

    2000-10-01

    To review the clinical characteristics, diagnosis, and visual outcome in patients with non-contact lens related Acanthamoeba keratitis and compare the findings with reported series of contact lens associated Acanthamoeba keratitis. Medical and microbiology records of 39 consecutive patients with a diagnosis of Acanthamoeba keratitis, at a tertiary eyecare centre in India between January 1996 and June 1998, were analysed retrospectively. A majority of the patients presented with poor visual acuity and large corneal stromal infiltrates (mean size 38.20 (SD 26. 18) mm). A predisposing factor was elicited in 19/39 (48.7%) patients (trauma 15, dirty water splash three, leaf juice one). None of the patients had worn contact lenses. Most patients (26/39 (66. 6%)) came from a low socioeconomic background. Complaint of severe pain was not a significant feature and radial keratoneuritis was seen in 1/39 (2.5%) patients. A ring infiltrate was present in 41.1% of cases. A clinical diagnosis of fungal keratitis was made in 45% of the patients before they were seen by us. However, all patients were diagnosed microbiologically at our institute based on demonstration of Acanthamoeba cysts in corneal scrapings (34/39) and/or culture of Acanthamoeba (34/39). Treatment with biguanides (PHMB, 15/38 (39.4%), PHMB with CHx, 23/38 (60.5%), one patient did not return for treatment) resulted in healing with scar formation in 27 out of 31(87.0%) followed up patients (mean time to healing 106.9 days). Overall visual outcome was poor with no statistical difference between cases diagnosed within 30 days (early) or 30 days after (late) start of symptoms. The visual outcome in cases requiring tissue adhesive (five) and keratoplasty (three) was also poor. This is thought to be the largest series of cases of Acanthamoeba keratitis in non-contact lens wearers. In such cases, the disease is advanced at presentation in most patients, pathognomonic clinical features are often not seen, disease

  8. Acanthamoeba keratitis: synergy between amebic and bacterial cocontaminants in contact lens care systems as a prelude to infection.

    Science.gov (United States)

    Bottone, E J; Madayag, R M; Qureshi, M N

    1992-01-01

    We encountered a patient with Acanthamoeba keratitis whose contact lens care solution contained numerous trophozoites and cysts admixed with Xanthomonas maltophilia organisms, many of which were adherent to the trophozoite surface and internalized within endocytic vacuoles. Because of this finding, we investigated the role of bacterial cocontaminants in contact lens care systems as substrates for the growth of Acanthamoeba spp. Individual cocultivation of Acanthamoeba castellanii and A. polyphaga with X. maltophilia, Flavobacterium breve, and Pseudomonas paucimobilis showed better enhancement (1.5x) of ameba growth after 96 h than that obtained in the presence of Staphylococcus aureus, S. epidermidis, and Escherichia coli, the standard cocultivation species used for isolation of amebae from clinical specimens. Our data suggest that contamination of contact lens care systems with Acanthamoeba spp. and a bacterial species capable of supporting amebic growth may be the first step in the pathogenesis of ameba-induced keratitis by the provision of large inocula of amebae. Images PMID:1401013

  9. Infection in a rat model reactivates attenuated virulence after long-term axenic culture of Acanthamoeba spp

    Directory of Open Access Journals (Sweden)

    Carolina De Marco Verissimo

    2013-11-01

    Full Text Available Prolonged culturing of many microorganisms leads to the loss of virulence and a reduction of their infective capacity. However, little is known about the changes in the pathogenic strains of Acanthamoeba after long culture periods. Our study evaluated the effect of prolonged culturing on the invasiveness of different isolates of Acanthamoeba in an in vivo rat model. ATCC strains of Acanthamoeba, isolates from the environment and clinical cases were evaluated. The in vivo model was effective in establishing the infection and differentiating the pathogenicity of the isolates and re-isolates. The amoebae cultured in the laboratory for long periods were less virulent than those that were recently isolated, confirming the importance of passing Acanthamoeba strains in animal models.

  10. Necrotizing Meningoencephalitis in a Captive Black and White Ruffed Lemur (Varecia variegata variegata) Caused by Acanthamoeba T4 Genotype.

    Science.gov (United States)

    Gaide, N; Pelandakis, M; Robveille, C; Albaric, O; Jouvion, G; Souchon, M; Risler, A; Abadie, J

    2015-11-01

    A mature male, black and white ruffed lemur (Varecia variegata variegata) died in a zoological garden after a 4-day history of lethargy and non-responsive convulsions. Necropsy and histopathological examinations revealed acute necrotizing and haemorrhagic meningoencephalitis with intralesional amoebas confirmed by immunohistochemistry. Acanthamoeba T4 genotype was identified as the causative agent of the brain lesion, based on amplification and sequencing of 18S ribosomal RNA genes. The presence of free-living amoebas in water and mud from the lemur's environment was investigated by morphological and molecular analyses. The two predominant genera, representing 80% of isolated amoebas, were Naegleria spp. and Acanthamoeba spp. All Acanthamoeba isolates belonged to the T4 genotype. To the author's knowledge, this is the first report of a meningoencephalitis due to Acanthamoeba T4 genotype in Lemuridae with concurrent analysis of pathological tissues and environment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Acanthamoeba genotypes T2, T4, and T11 in soil sources from El Hierro island, Canary Islands, Spain.

    Science.gov (United States)

    Reyes-Batlle, María; Zamora-Herrera, Jonadab; Vargas-Mesa, Alejandro; Valerón-Tejera, Marco Antonio; Wagner, Carolina; Martín-Navarro, Carmen Ma; López-Arencibia, Atteneri; Sifaoui, Ines; Martínez-Carretero, Enrique; Valladares, Basilio; Piñero, José E; Lorenzo-Morales, Jacob

    2016-08-01

    The genus Acanthamoeba includes pathogenic strains which are causative agents of keratitis and encephalitis that often may end fatal in humans and other animals. In the present study, forty soil samples were collected in the island of El Hierro, Canary Islands, Spain, and checked for the presence of Acanthamoeba. Samples were cultivated onto 2 % non-nutrient agar plates seeded with a layer of heat killed Escherichia coli. Amplification by PCR and sequencing of the DF3 region of the 18S rDNA of Acanthamoeba was carried out in order to confirm morphological identification of the amoebae. Furthermore, Acanthamoeba spp. was isolated from 47.5 % of soil samples. Moreover, genotypes T2, T4, and T11 were identified in these samples. To the best of our knowledge, this is the first study to establish genotypes T2, T4, and T11 in soil sources from El Hierro island.

  12. Biochemical kinetic characterization of the Acanthamoeba myosin-I ATPase.

    Science.gov (United States)

    Ostap, E M; Pollard, T D

    1996-03-01

    Acanthamoeba myosin-IA and myosin-IB are single-headed molecular motors that may play an important role in membrane-based motility. To better define the types of motility that myosin-IA and myosin IB can support, we determined the rate constants for key steps on the myosin-I ATPase pathway using fluorescence stopped-flow, cold-chase, and rapid-quench techniques. We determined the rate constants for ATP binding, ATP hydrolysis, actomyosin-I dissociation, phosphate release, and ADP release. We also determined equilibrium constants for myosin-I binding to actin filaments, ADP binding to actomyosin-I, and ATP hydrolysis. These rate constants define an ATPase mechanism in which (a) ATP rapidly dissociates actomyosin-I, (b) the predominant steady-state intermediates are in a rapid equilibrium between actin-bound and free states, (c) phosphate release is rate limiting and regulated by heavy-chain phosphorylation, and (d) ADP release is fast. Thus, during steady-state ATP hydrolysis, myosin-I is weakly bound to the actin filament like skeletal muscle myosin-II and unlike the microtubule-based motor kinesin. Therefore, for myosin-I to support processive motility or cortical contraction, multiple myosin-I molecules must be specifically localized to a small region on a membrane or in the actin-rich cell cortex. This conclusion has important implications for the regulation of myosin-I via localization through the unique myosin-I tails. This is the first complete transient kinetic characterization of a member of the myosin superfamily, other than myosin-II, providing the opportunity to obtain insights about the evolution of all myosin isoforms.

  13. Interactions between Human Norovirus Surrogates and Acanthamoeba spp.

    Science.gov (United States)

    Hsueh, Tun-Yun

    2015-01-01

    Human noroviruses (HuNoVs) are the most common cause of food-borne disease outbreaks, as well as virus-related waterborne disease outbreaks in the United States. Here, we hypothesize that common free-living amoebae (FLA)—ubiquitous in the environment, known to interact with pathogens, and frequently isolated from water and fresh produce—could potentially act as reservoirs of HuNoV and facilitate the environmental transmission of HuNoVs. To investigate FLA as reservoirs for HuNoV, the interactions between two Acanthamoeba species, A. castellanii and A. polyphaga, as well as two HuNoV surrogates, murine norovirus type 1 (MNV-1) and feline calicivirus (FCV), were evaluated. The results showed that after 1 h of amoeba-virus incubation at 25°C, 490 and 337 PFU of MNV-1/ml were recovered from A. castellanii and A. polyphaga, respectively, while only few or no FCVs were detected. In addition, prolonged interaction of MNV-1 with amoebae was investigated for a period of 8 days, and MNV-1 was demonstrated to remain stable at around 200 PFU/ml from day 2 to day 8 after virus inoculation in A. castellanii. Moreover, after a complete amoeba life cycle (i.e., encystment and excystment), infectious viruses could still be detected. To determine the location of virus associated with amoebae, immunofluorescence experiments were performed and showed MNV-1 transitioning from the amoeba surface to inside the amoeba over a 24-h period. These results are significant to the understanding of how HuNoVs may interact with other microorganisms in the environment in order to aid in its persistence and survival, as well as potential transmission in water and to vulnerable food products such as fresh produce. PMID:25841006

  14. The effect of Acanthamoeba concentration on adherence to four types of unworn soft contact lenses.

    Science.gov (United States)

    Kelly, L D; Xu, L

    1995-01-01

    Contact lens wear is a predominant risk factor for Acanthamoeba keratitis. The exact nature of the relationship between organism concentration and contact lens adherence is poorly understood. We investigated the effect of Acanthamoeba inoculation concentration on adherence to four categories of contact lenses of varying polymers and water content. Acanthamoeba polyphaga was harvested in log growth phase at 5 days subculture and suspended in PBS at concentrations of 1 x 10(2), 10(3), 10(4), 10(5), and 10(6) organisms/mL (trophozoite:cyst ratio 90:10 +/- 2). Sterile unworn polymacon, etafilcon, lidofilcon, and bufilcon contact lens segments were exposed to Acanthamoeba for 2 hours. Acanthamoeba adherence was quantified using phase contrast microscopy. For all lens types, trophozoite adherence increased as the concentration of inoculum increased, but the relationship was not directly proportional. In all cases the minimal adherence was observed at 10(2). Trophozoite adherence increased disproportionate to cysts for all contact lens types. The greatest adherence was to lidofilcon lenses. At all concentrations adherence was greater to lidofilcon than etafilcon or polymacon, and greater to bufilcon than etafilcon or polymacon at the P < 0.01 level. Adherence was significantly greater to lidofilcon than bufilcon only at 1 x 10(5) and 10(6); P < 0.05 (ANOVA). This study suggests that adherence of A. polyphaga to contact lenses increases with the number of organisms in the inoculum, but the relationship is not directly proportional. The number of adherent organisms varies by contact lens type, with the greatest adherence to lidofilcon and the least to etafilcon lenses.

  15. Coinfection with Acanthamoeba and Pseudomonas in contact lens-associated keratitis.

    Science.gov (United States)

    Sharma, Reetika; Jhanji, Vishal; Satpathy, Gita; Sharma, Namrata; Khokhar, Sudarshan; Agarwal, Tushar

    2013-02-01

    To report coinfection with Acanthamoeba and Pseudomonas aeruginosa in a case with contact lens-associated keratitis. A 20-year-old woman presented to the emergency department of our hospital with a 4-day history of progressively increasing pain, redness, photophobia, mucopurulent discharge, and diminution of vision in her right eye. She was being treated for contact lens-related Pseudomonas keratitis in another hospital before presentation. Gram stain of corneal scrapings revealed gram-negative bacilli. Both Gram stain and 10% KOH wet mount showed the presence of Acanthamoeba cysts. Microbiological cultures obtained from contact lenses and contact lens storage case showed the presence of Pseudomonas aeruginosa and Acanthamoeba. Topical therapy was started in the form of hourly gentamycin 1.3%, cefazolin 5%, chlorhexidine 0.02%, propamidine 0.1%, polymyxin B 30,000 IU eye drops, and neosporin (neomycin, bacitracin, polymyxin) eye ointment four times a day. Symptomatic improvement was observed within 48 hours, along with a decrease in the density of infiltrates and a reduction in the anterior chamber reaction. Repeat corneal scrapings on day 10 showed Acanthamoeba but no bacilli. Progressive resolution of the infiltrate was noted during the next few days. Epithelialization was complete by day 24, following which the amoebicidal therapy was tapered during the next 4 weeks. Complete resolution of keratitis was achieved after 7 weeks of treatment. Both P. aeruginosa and Acanthamoeba are potentially devastating causes of microbial keratitis. Our case highlights the importance of considering the possibility of a concurrent infection in cases with contact lens-related keratitis.

  16. Anti-amoebic properties of a Malaysian marine sponge Aaptos sp. on Acanthamoeba castellanii.

    Science.gov (United States)

    Nakisah, M A; Ida Muryany, M Y; Fatimah, H; Nor Fadilah, R; Zalilawati, M R; Khamsah, S; Habsah, M

    2012-03-01

    Crude methanol extracts of a marine sponge, Aaptos aaptos, collected from three different localities namely Kapas, Perhentian and Redang Islands, Terengganu, Malaysia, were tested in vitro on a pathogenic Acanthamoeba castellanii (IMR isolate) to examine their anti-amoebic potential. The examination of anti-Acanthamoebic activity of the extracts was conducted in 24 well plates for 72 h at 30 °C. All extracts possessed anti-amoebic activity with their IC(50) values ranging from 0.615 to 0.876 mg/mL. The effect of the methanol extracts on the surface morphology of A. castellanii was analysed under scanning electron microscopy. The ability of the extracts to disrupt the amoeba cell membrane was indicated by extensive cell's blebbing, changes in the surface morphology, reduced in cell size and with cystic appearance of extract-treated Acanthamoeba. Number of acanthapodia and food cup was also reduced in this Acanthamoeba. Morphological criteria of apoptosis in Acanthamoeba following treatment with the sponge's extracts was determined by acridine orange-propidium iodide staining and observed by fluorescence microscopy. By this technique, apoptotic and necrotic cells can be visualized and quantified. The genotoxic potential of the methanol extracts was performed by the alkaline comet assay. All methanol extracts used were significantly induced DNA damage compared to untreated Acanthamoeba by having high percentage of scores 1, 2, and 3 of the DNA damage. Results from cytotoxicity and genotoxicity studies carried out in the present study suggest that all methanol extracts of A. aaptos have anti-amoebic properties against A. castellanii.

  17. Evaluation of Ozone Application in Dental Unit Water Lines Con¬taminated with Pathogenic Acanthamoeba

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    Wafaa HIKAL

    2015-10-01

    Full Text Available Background: In this study morphological and molecular characterization of Acan­thamoeba strains, isolated from dental unit waterlines (DUWLs were surveyed and the levels of disinfection achievable in vitro by the application of ozone disinfect­ant to DUWLs were evaluate.Methods: Water samples were collected from air-water syringes, cup fillers and tap water before and at the end of the working day. They were cultured on non-nutrient agar (NNA plates. Species identification was carried out with a PCR assay based on sequence analysis of the 18S rRNA gene. The cellular response to ozone was tested on Acanthamoeba cyst with different doses at different contact time in vitro twice.Results: Prevalence rates for Acanthamoeba contamination were 100, 100 and 72% for air-water syringes, cup fillers and tap water, respectively. The morphological analysis revealed the presence of A. castellanii, A. griffin, A. hatchitti and A. lenticulata. Phylogenetic analysis of the sequences showed the four strains to be closely related to a sequence type (T3, T4, T5 and T11. Acanthamoeba cells were stained with try­pan blue, which revealed killed of Acanthamoeba instantaneously after 10 minutes in ozonized water. There was no growth of Acanthamoeba occurred after ozone treat­ment in water bottles for 5 minutes with a flow rate of 500 mg/hour.Conclusion: Ozone can play an important role in controlling the problem of contami­nation of DUWLs as a potent disinfectant.

  18. Molecular characterization of Acanthamoeba strains isolated from the oral cavity of hemodialysis patients in Iran.

    Science.gov (United States)

    Niyyati, Maryam; Arab-Mazar, Zahra; Lasjerdi, Zohreh; Lorenzo-Morales, Jacob; Espotin, Adel; Yadegarynia, Davood; Gachkar, Latif; Rahmati Roodsari, Sara

    2017-11-01

    Free-living amoebae (FLA) of the genus Acanthamoeba are opportunistic pathogenic agents able to cause life-threatening infections in immunosuppressed patients. Chronic kidney disease impairs adaptive and innate immunity. Thus, patients with chronic kidney disease are prone to opportunistic infections by potentially pathogenic FLA. Therefore, in the present study, the investigation of Acanthamoeba genotypes isolated from the oral cavity of hemodialysis patients of reference hospitals in Iran was aimed, using both morphology and molecular (sequence-based analysis) tools. Furthermore, classification of the strains at the genotype level was performed on the basis of differences in the diagnostic fraction 3 (DF3) region of the 18S rRNA gene. The pathogenic potential of the isolated amoebae was also determined using thermotolerance and osmotolerance assays. Out of the 187 oral cavity samples investigated, nine (4.8%) were positive for FLA. DNA sequencing of the ASA.A1 region of the 18S rRNA gene revealed that the isolated strains belonged to the Acanthamoeba T1 and T4 genotypes. Genotype T1 was isolated for the first time from a patient in Iran. Interestingly, the T1 strain (AN2 strain) exhibits a high pathogenic potential in tolerance assays. The pathogenicity assay revealed that five strains were able to grow at high temperatures (37-40 °C) and high osmolarity (0.5 and 1 M D-mannitol) conditions; thus, they were considered as potentially pathogenic strains. Moreover, two of the patients were positive for Vermamoeba genus. The present study is the first report of genotype T1 isolation in Iran and the first to identify the occurrence of Acanthamoeba and Vermamoeba genera in patients undergoing hemodialysis worldwide. Monitoring hemodialysis and renal failure patients should be a priority for possible control of Acanthamoeba and other FLA-related diseases.

  19. Molecular diagnosis of Acanthamoeba keratitis: evaluation in rat model and application in suspected human cases.

    Science.gov (United States)

    Costa, Adriana Oliveira; Furst, Cinthia; Rocha, Lucas Oliveira; Cirelli, Cecília; Cardoso, Carolina Neris; Neiva, Fagner Salmazo; Possamai, Cynara Oliveira; de Assis Santos, Daniel; Thomaz-Soccol, Vanete

    2017-04-01

    Acanthamoeba keratitis (AK) is a progressive corneal infection that demands rapid and sensitive techniques for diagnosis to avoid risk of visual impairment. We evaluated two DNA extraction techniques and a semi-nested-PCR (snPCR) targeting the 18S rRNA gene to detect Acanthamoeba cysts and trophozoites. The most effective protocol was evaluated in samples of corneal scrapings and biopsies from an AK rat model and applied to diagnosis of human cases of AK. DNA extraction performed with a commercial kit based on DNA binding to magnetic beads was more efficient than a method based on alkaline lysis, allowing the detection of one trophozoite and one cyst of Acanthamoeba in samples prepared from cultures. This technique and sn-PCR were applied in corneal scrapings of rats experimentally infected with Acanthamoeba (n = 6), resulting in 100% of positivity, against 16.7% (n = 6) of positive identification in culture method using non-nutrient agar (NNA) with Escherichia coli. Corneal biopsies from rats were also tested (n = 6) and resulted in positivity in all samples in both molecular and culture methods. Eight out of ten presumptive human cases of Acanthamoeba keratitis were also confirmed by sn-PCR of scrapping samples, while the culture method was positive in only four cases. We discuss that animal model of AK can be an efficient tool to validate diagnostic methods and conclude that DNA extraction with the kit and snPCR protocol described here is an effective alternative for diagnosis of AK.

  20. Hypoxia attenuates inflammatory mediators production induced by Acanthamoeba via Toll-like receptor 4 signaling in human corneal epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Hong [Department of Ophthalmology, Qilu Hospital, Shandong University, 107, Wenhua Xi Road, Jinan 250012 (China); The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Public Health, Qilu Hospital, Shandong University, 107, Wenhua Xi Road, Jinan 250012 (China); Wu, Xinyi, E-mail: xywu8868@163.com [Department of Ophthalmology, Qilu Hospital, Shandong University, 107, Wenhua Xi Road, Jinan 250012 (China)

    2012-04-13

    Highlights: Black-Right-Pointing-Pointer Hypoxia attenuates Acanthamoeba-induced the production of IL-8 and IFN-{beta}. Black-Right-Pointing-Pointer Hypoxia inhibits TLR4 expression in a time-dependent manner in HCECs. Black-Right-Pointing-Pointer Hypoxia inhibits Acanthamoeba-induced the activation of NF-{kappa}B and ERK1/2 in HCECs. Black-Right-Pointing-Pointer Hypoxia decreases Acanthamoeba-induced inflammatory response via TLR4 signaling. Black-Right-Pointing-Pointer LPS-induced the secretion of IL-6 and IL-8 is abated by hypoxia via TLR4 signaling. -- Abstract: Acanthamoeba keratitis (AK) is a vision-threatening corneal infection that is intimately associated with contact lens use which leads to hypoxic conditions on the corneal surface. However, the effect of hypoxia on the Acanthamoeba-induced host inflammatory response of corneal epithelial cells has not been studied. In the present study, we investigated the effect of hypoxia on the Acanthamoeba-induced production of inflammatory mediators interleukin-8 (IL-8) and interferon-{beta} (IFN-{beta}) in human corneal epithelial cells and then evaluated its effects on the Toll-like receptor 4 (TLR4) signaling, including TLR4 and myeloid differentiation primary response gene (88) (MyD88) expression as well as the activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-{kappa}B) and extracellular signal-regulated kinases 1/2 (ERK1/2). We then studied the effect of hypoxia on a TLR4-specific inflammatory response triggered by the TLR4 ligand lipopolysaccharide (LPS). Our data showed that hypoxia significantly decreased the production of IL-8 and IFN-{beta}. Furthermore, hypoxia attenuated Acanthamoeba-triggered TLR4 expression as well as the activation of NF-{kappa}B and ERK1/2, indicating that hypoxia abated Acanthamoeba-induced inflammatory responses by affecting TLR4 signaling. Hypoxia also inhibited LPS-induced IL-6 and IL-8 secretion, myeloid differentiation primary response gene (88

  1. Hypoxia attenuates inflammatory mediators production induced by Acanthamoeba via Toll-like receptor 4 signaling in human corneal epithelial cells

    International Nuclear Information System (INIS)

    Pan, Hong; Wu, Xinyi

    2012-01-01

    Highlights: ► Hypoxia attenuates Acanthamoeba-induced the production of IL-8 and IFN-β. ► Hypoxia inhibits TLR4 expression in a time-dependent manner in HCECs. ► Hypoxia inhibits Acanthamoeba-induced the activation of NF-κB and ERK1/2 in HCECs. ► Hypoxia decreases Acanthamoeba-induced inflammatory response via TLR4 signaling. ► LPS-induced the secretion of IL-6 and IL-8 is abated by hypoxia via TLR4 signaling. -- Abstract: Acanthamoeba keratitis (AK) is a vision-threatening corneal infection that is intimately associated with contact lens use which leads to hypoxic conditions on the corneal surface. However, the effect of hypoxia on the Acanthamoeba-induced host inflammatory response of corneal epithelial cells has not been studied. In the present study, we investigated the effect of hypoxia on the Acanthamoeba-induced production of inflammatory mediators interleukin-8 (IL-8) and interferon-β (IFN-β) in human corneal epithelial cells and then evaluated its effects on the Toll-like receptor 4 (TLR4) signaling, including TLR4 and myeloid differentiation primary response gene (88) (MyD88) expression as well as the activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and extracellular signal-regulated kinases 1/2 (ERK1/2). We then studied the effect of hypoxia on a TLR4-specific inflammatory response triggered by the TLR4 ligand lipopolysaccharide (LPS). Our data showed that hypoxia significantly decreased the production of IL-8 and IFN-β. Furthermore, hypoxia attenuated Acanthamoeba-triggered TLR4 expression as well as the activation of NF-κB and ERK1/2, indicating that hypoxia abated Acanthamoeba-induced inflammatory responses by affecting TLR4 signaling. Hypoxia also inhibited LPS-induced IL-6 and IL-8 secretion, myeloid differentiation primary response gene (88) MyD88 expression and NF-κB activation, confirming that hypoxia suppressed the LPS-induced inflammatory response by affecting TLR4 signaling. In conclusion

  2. Effect of time and washing on the adhesion of Acanthamoeba to extended wear disposable hydrogel contact lenses.

    Science.gov (United States)

    Ramachandran, L; Janakiraman, D; Sharma, S; Rao, G N

    1997-04-01

    This study was undertaken to determine the extent of adhesion of cysts and trophozoites of Acanthamoeba to worn disposable hydrogel lenses and to study the effect of time, lens material, and washing on the adhesion. Etafilcon A (58% water content) and Polymacon (38% water content) lenses worn on a 6 night extended wear basis and collected aseptically in PBS pH 7.2, were used for the study. Unworn lenses of the same materials were used as controls. Segments of lenses were incubated in Acanthamoeba suspension (cysts and trophozoites) and examined at 0, 5, and 24 hours, either washed or unwashed, for adherent Acanthamoeba. The amoebae adherent per square mm surface of the lens were enumerated. Levels of adhesion in various groups were compared using Wilcoxon sign rank test. At 0 hours, unwashed worn Polymacon lenses showed significantly greater adherence than Etafilcon A lenses compared to the controls (P = 0.0469). However, there was no difference at 5 and 24 hours exposure time between the lenses. At 24 hours the adhesion of Acanthamoeba was greater for washed worn lenses of both types compared to washed lenses of controls (P = 0.002, 0.012). Amoebae adhered with equal affinity to both types of lenses but adhered with greater affinity to worn lenses than unworn lenses. Adhesion of Acanthamoeba to worn disposable lenses may be a factor in the pathogenesis of Acanthamoeba keratitis in disposable lens wearers.

  3. Acanthamoeba produces disseminated infection in locusts and traverses the locust blood-brain barrier to invade the central nervous system

    Directory of Open Access Journals (Sweden)

    Kirk Ruth

    2010-07-01

    Full Text Available Abstract Background Many aspects of Acanthamoeba granulomatous encephalitis remain poorly understood, including host susceptibility and chronic colonization which represent important features of the spectrum of host-pathogen interactions. Previous studies have suggested locusts as a tractable model in which to study Acanthamoeba pathogenesis. Here we determined the mode of parasite invasion of the central nervous system (CNS. Results Using Acanthamoeba isolates belonging to the T1 and T4 genotypes, the findings revealed that amoebae induced sickness behaviour in locusts, as evidenced by reduced faecal output and weight loss and, eventually, leading to 100% mortality. Significant degenerative changes of various tissues were observed by histological sectioning. Both isolates produced disseminated infection, with viable amoebae being recovered from various tissues. Histological examination of the CNS showed that Acanthamoeba invaded the locust CNS, and this is associated with disruption of the perineurium cell/glial cell complex, which constitutes the locust blood-brain barrier. Conclusions This is the first study to demonstrate that Acanthamoeba invades locust brain by modulating the integrity of the insect's blood-brain barrier, a finding that is consistent with the human infection. These observations support the idea that locusts provide a tractable model to study Acanthamoeba encephalitis in vivo. In this way the locust model may generate potentially useful leads that can be tested subsequently in mammalian systems, thus replacing the use of vertebrates at an early stage, and reducing the numbers of mammals required overall.

  4. Isolation and genotyping of free-living environmental isolates of Acanthamoeba spp. from bromeliads in Southern Brazil.

    Science.gov (United States)

    Landell, Melissa Fontes; Salton, Juliana; Caumo, Karin; Broetto, Leonardo; Rott, Marilise B

    2013-07-01

    Species of Acanthamoeba are frequently isolated from distinct environmental sources such as water, soil, dust and air. They are responsible to cause infections and disease in humans and animals. In addition, Acanthamoeba sp. are considered an important reservoir of bacteria, virus and fungi, which act as "Trojan horses" to protect these microorganisms of harsh environmental conditions. In this study, nine Acanthamoeba isolates from bromeliads phylloplane were identified based on the morphology of cyst and trophozoite forms. The genotype level was accessed by the sequence analysis of Acanthamoeba small-subunit rRNA gene. Genotypic characterization grouped five isolates in the genotype T2/T6, three in the T4 genotype and one in the genotype T16. The results obtained indicate that the genotype T2/T6 is common on phylloplane. To predict the pathogenic potential of the Acanthamoeba isolates, thermo and osmotolerance assays were employed, although all isolates were capable of surviving at temperatures of 37°C, other tests will be conducted in the future to determine the potential pathogenic of the isolates. Altogether, our results revealed the importance of the presence of Acanthamoeba associated with bromeliads in Rio Grande do Sul, Brazil, and the necessity for further studies to determine the environmental distribution and the role of these species. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. Acanthamoeba infection in lungs of mice expressed by toll-like receptors (TLR2 and TLR4).

    Science.gov (United States)

    Derda, Monika; Wojtkowiak-Giera, Agnieszka; Kolasa-Wołosiuk, Agnieszka; Kosik-Bogacka, Danuta; Hadaś, Edward; Jagodziński, Paweł P; Wandurska-Nowak, Elżbieta

    2016-06-01

    Toll-like receptors (TLRs) play a key role in the innate immune responses to a variety of pathogens including parasites. TLRs are among the most highly conserved in the evolution of the receptor family, localized mainly on cells of the immune system and on other cells such as lung cells. The aim of this study was to determine for the first time the expression of TLR2 and TLR4 in the lung of Acanthamoeba spp. infected mice using quantitative real-time polymerase chain reaction (Q-PCR) and immunohistochemical (IHC) staining. The Acanthamoeba spp. were isolated from a patient with Acanthamoeba keratitis (AK) (strain Ac 55) and from environmental samples of water from Malta Lake (Poznań, Poland - strain Ac 43). We observed a significantly increased level of expression of TLR2 as well as TLR4 mRNA from 2 to 30 days post Acanthamoeba infection (dpi) in the lungs of mice infected with Ac55 (KP120880) and Ac43 (KP120879) strains. According to our observations, increased TLR2 and TLR4 expression in the pneumocytes, interstitial cells and epithelial cells of the bronchial tree may suggest an important role of these receptors in protective immunity against Acanthamoeba infection in the lung. Moreover, increased levels of TLR2 and TLR4 mRNA expression in infected Acanthamoeba mice may suggest the involvement of these TLRs in the recognition of this amoeba pathogen-associated molecular pattern (PAMP). Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Isolation and molecular characterization of Acanthamoeba genotypes in recreational and domestic water sources from Jamaica, West Indies.

    Science.gov (United States)

    Todd, Cheridah D; Reyes-Batlle, María; Piñero, José E; Martínez-Carretero, Enrique; Valladares, Basilio; Streete, Don; Lorenzo-Morales, Jacob; Lindo, John F

    2015-09-01

    Free living amoebae (FLA) are amphizoic protozoa that are ubiquitous in nature. Infection with FLA may result in neurological, ocular and skin infections. Exposure to Acanthamoeba occurs frequently through water contact and knowledge of the presence of the organisms in water sources is important in understanding transmission dynamics. The distribution of Acanthamoeba was studied in recreational and domestic water samples collected from across Jamaica. Morphological assessment and polymerase chain reaction revealed Acanthamoeba spp. isolates in 50.6% (42/83) and 17.3% (14/81) of recreational and domestic water, respectively. Sequencing of the DF3 region of the 18S rDNA resulted in the identification of genotypes T3, T4, T5, T10 and T11 corresponding to Acanthamoeba spp: A. griffini, A. triangularis, A. lenticulata, A. culbertsoni and A. hatchetti. Moreover, T4 was the most frequently isolated genotype in both recreational and domestic water. Thermotolerance and osmotolerance assays indicated that most isolates were potentially pathogenic. This is the first report of T3 and T10 genotypes in the Caribbean and the first report of these Acanthamoeba spp. in Jamaican waters. The study shows that there is potential risk of infection to contact wearers who practise poor lens care. Further, Acanthamoeba should be considered as a cause of neurological infections in Jamaica.

  7. Isolation and molecular characterization of Acanthamoeba genotypes isolated from soil sources of public and recreational areas in Iran.

    Science.gov (United States)

    Karamati, Seyed Ahmad; Niyyati, Maryam; Lorenzo-Morales, Jacob; Lasjerdi, Zohreh

    2016-12-01

    Pathogenic strains of Acanthamoeba are causative agents of a sight threating infection of the cornea known as Acanthamoeba keratitis. AK cases have been reported in Iran recently due to inappropriate usage of contact lens maintenance and most patients report a contact with contaminated sources such as dust, water or soil. Sixty soil samples were collected from public and recreational areas in the province of East Azerbaijan, Iran and checked for the presence of Acanthamoeba spp. Samples were cultured on non-nutrient agar plates seeded with heat killed Escherichia coli. PCR and sequencing of the DF3 region were carried out in order to genotype the isolated strains of Acanthamoeba. Thermotolerance and osmotolerance assays were performed in order to investigate the pathogenic potential of isolated Acanthamoeba strains. Acanthamoeba spp. was isolated from 41.6% of soil samples and genotyping of the strains resulted in the identification of genotypes T3, T4, T5 and T11. Most of the isolates belonging to genotypes T3 and T4 showed high pathogenic potential, indicating that they might present a potential health hazard for humans and other animals in this region. To the best of our knowledge, this is the first report on the identification of genotypes T3 and T11 from soil sources in the country.

  8. Isolation and molecular characterization of Acanthamoeba strains isolated from the oral cavity of immunosuppressed individuals in Tehran, Iran.

    Science.gov (United States)

    Memari, Fatemeh; Niyyati, Maryam; Lorenzo-Morales, Jacob; Jonaydi, Zaynab

    2016-09-01

    Acanthamoeba spp. is an opportunistic protozoan parasite which is the causative agent of granulomatous amoebic encephalitis (GAE) and Acanthamoeba keratitis (AK). GAE usually occurs in immunocompromised patients which in most cases is fatal. The present study was conducted to determine the genotypes of Acanthamoeba isolated from patients with compromised immunological status. For this purpose, 90 samples from the oral cavity of these individuals were collected in different hospitals of Tehran, Iran using sterile cotton swabs. Samples were cultured in 2% Non-Nutrient Agar (NNA) plates in order to check for the presence of amoebae. Identification of isolates was carried out using both morphological and molecular tools. The pathogenic potential of the obtained strains was assessed by performing osmo- and thermotolerance assays as previously described. Genotyping of the isolates was carried out by PCR/sequencing of the DF3 region of the 18S rDNA gene of Acanthamoeba. From the 90 collected samples, 11 (13.4%) were positive for Acanthamoeba genus. Molecular analysis revealed the presence of genotypes T3, T4 and T11, although most of the isolates belonged to genotype T4. Only 3 of the isolates genotyped as T4 were positive for the pathogenic potential assays. To this end if the immunological status is considered as one of the key factors for the development of GAE due to Acanthamoeba in the previous reported cases, individuals suffering from the conditions mentioned in this study should be considered as a high risk group of population in Iran and worldwide.

  9. The Characterization of an Adrenergic Signalling System Involved in the Encystment of the Ocular Pathogen Acanthamoeba spp.

    Science.gov (United States)

    Heaselgrave, Wayne; Kilvington, Simon

    2016-09-01

    The aim of this study was to identify and characterize the receptor system involved in controlling encystment in Acanthamoeba using specific agonists and antagonists and to examine whether endogenous stores of catecholamines are produced by the organism. Acanthamoeba trophozoites suspended in axenic growth medium were exposed to adrenoceptor agonists and antagonists to determine which compounds promoted or prevented encystment. Second, trophozoites were cultured in medium containing a catecholamine synthesis inhibitor to investigate the effect this had on natural encystment. Nonspecific adrenoceptor agonists including epinephrine, isoprotenerol, and the selective β1 adrenoceptor agonist dobutamine were found to cause > 90% encystment of Acanthamoeba trophozoites compared to  55%. Cultures of Acanthamoeba with the catecholamine synthesis inhibitor α-methyl-p-tyrosine significantly reduced the level of amoebic encystment compared to controls. In conclusion, Acanthamoeba appear to contain a functional adrenergic receptor system of unknown structure which is involved in initiating the encystment process that can be activated and blocked by β1 agonists and antagonists respectively. Furthermore, the presence of this receptor system in Acanthamoeba indicates that topical β adrenoceptor blockers may be effective adjunct therapy by reducing the transformation of trophozoites into the highly resistant cyst stage. © 2016 The Author(s) Journal of Eukaryotic Microbiology © 2016 International Society of Protistologists.

  10. Actualización en el tratamiento de la neuropatía óptica inflamatoria desmielinizante Updating on the treatment of the demyelinating inflammatory optical neuropathy

    Directory of Open Access Journals (Sweden)

    Yaimara Hernández Silva

    2011-06-01

    Full Text Available Se realizó una revisión bibliográfica con el objetivo de proporcionar una actualización de las drogas que se emplean para retrasar la aparición de esclerosis múltiple en el manejo de la neuropatía óptica inflamatoria desmielinizante. El artículo presenta el origen y la justificación de la terapia esteroidea en este grupo de enfermedad, así como los mecanismos de acción y beneficios de tratamientos más modernos como los inmunomoduladores e inmunosupresores. El trabajo también introduce muchas de las drogas con efectos neuroprotectores que se encuentran en fases experimentales, cuyo uso prevendría la neurodegeneración que se produce a nivel de las células ganglionares retinianas en esta enfermedad neurológica. Las opciones terapéuticas actuales ofrecen variantes de tratamiento adicionales a pacientes con mayores probabilidades de desarrollo de esclerosis múltiple y retrasan la aparición de un segundo brote, así como las secuelas invalidantes que esta suele originar.A bibliographic review was conducted to provide an updating of drugs used to retard the appearance of multiple sclerosis in the management of the demyelinating inflammatory optical neuropathy. Present paper shows the origin and the justification of the steroid therapy in this disease, as well as the mechanisms of action and benefits of more recent treatments, e.g. the ongoing immunomodulations and immunosuppressive ones and also to introduce many drugs in experimental phase having neuroprotection effects whose use will prevent the neurodegenerative effect produced at level of the retinal ganglion cells in this neurologic disease. The current therapeutical options offer variants of additional treatment to those patients with greater possibilities to development multiple sclerosis and retarding the appearance of a second outbreak, as well as its disabling sequelae.

  11. Validación de la escala de Alvarado y criterios del síndrome de respuesta inflamatoria sistémica para apendicitis aguda complicada, Hospital Vicente Corral Moscoso, Cuenca 2014

    OpenAIRE

    Guachún Guachún, Mayra Alejandra

    2016-01-01

    Objetivo: determinar la validez de la escala de Alvarado y criterios del síndrome de respuesta inflamatoria sistémica para apendicitis aguda complicada en el área de emergencia de cirugía del Hospital Vicente Corral Moscoso. Materiales y Métodos: se realizó un estudio de validación de prueba diagnóstica, la muestra fue de 360 pacientes que acudieron de enero a noviembre del 2014 al área de emergencia y que cumplieron con los criterios de inclusión; se aplicó un cuestionario. Con la base de...

  12. Miopatías inflamatorias idiopáticas : Caracterización clínica, de laboratorio y patológica de una serie de 35 pacientes.

    OpenAIRE

    Sahuquillo Hernández, Patricia

    2012-01-01

    Estudio descriptivo y retrospectivo de una serie de 35 pacientes con miopatía inflamatoria idiopática, que a partir de la recogida de variables clínicas, de laboratorio y patológicas, se propone los siguientes objetivos: caracterizar a este grupo de enfermedades, clasificar a los pacientes en subgrupos en función de criterios histopatológicos y caracterizar los distintos subgrupos analizando qué variables permiten diferenciar mejor cada categoría. Estudi descriptiu y retrospectiu de una se...

  13. Cirugía bariátrica en enfermedad inflamatoria intestinal: presentación de un caso clínico y revisión de la literatura

    OpenAIRE

    Carmen Tenorio Jiménez; Gregorio Manzano García; Inmaculada Prior Sánchez; María Sierra Corpas Jiménez; María José Molina Puerta; Pedro Benito López

    2013-01-01

    La Enfermedad Inflamatoria Intestinal (EII) raramente se asocia a obesidad, ya que la malabsorción es una característica frecuente de este grupo de patologías (1). Sin embargo, algunos pacientes pueden padecer obesidad mórbida asociada a complicaciones y refractaria a tratamiento dietético y beneficiarse de la cirugía bariátrica. Incluso se ha postulado que podría producirse una mejoría de la EII al disminuir los marcadores inflamatorios tras la cirugía (2). No obstante, los pacientes pueden ...

  14. Dano muscular: resposta inflamatória sistêmica após ações excêntricas máximas Daño muscular: respuesta inflamatoria sistémica después de acciones excéntricas máximas Muscle damage: systemic inflammatory response after maximal eccentric actions

    Directory of Open Access Journals (Sweden)

    Ricardo Paes de Barros Berton

    2012-09-01

    Full Text Available O objetivo deste estudo foi analisar a resposta inflamatória induzida por grande número de ações excêntricas (AE máximas realizadas pelos flexores do cotovelo. Participaram do estudo nove homens jovens, que realizaram 35 séries de seis AE nos flexores de cotovelo, com intervalo de um minuto, utilizando um dinamômetro isocinético em uma velocidade de 210º.s-1. As variáveis mensuradas foram: a contração isométrica voluntaria máxima (CIVM, a amplitude de movimento (AM, a dor muscular de inicio tardio (DMIT, a interleucina-6 (IL-6 e o fator de necrose tumoral alfa (TNF-α. Alterações significantes foram observadas para os marcadores indiretos de dano muscular (CIVM, AM e DMIT, entretanto não houve modificações para os marcadores inflamatórios (IL-6 e TNF-α. Em conclusão, os resultados demonstraram que mesmo com alterações nos marcadores indiretos de dano muscular após a realização de um grande número de AE não foram observadas alterações na resposta inflamatória sistêmica.El objetivo del presente estudio fue analizar la magnitud de la respuesta inflamatoria inducida por un gran número de acciones excéntricas (AE de los flexores del codo. Han participado del estudio nueve jóvenes que llevaron a cabo 35 series de seis AE de los flexores del codo, con un intervalo de un minuto, utilizando un dinamómetro isocinético a 210º.s-1. Fueran mensurados la máxima contracción voluntaria isométrica (CIVM, la amplitud de movimiento (AM, el dolor muscular de aparición tardía (DMIT, la interleucina 6 (IL-6 y el factor de necrosis tumoral alfa (TNF-α. Se observaron cambios significativos para los marcadores de daño muscular (CIVM, AM y DMIT, sin embargo, no hubo cambios en los marcadores de inflamación IL-6 y TNF-α. En conclusión, los resultados indican que mismo con un gran número de AE y cambios en los marcadores indirectos de daño muscular, no se observaron cambios en la respuesta inflamatoria sist

  15. Frequency and Genotyping of Acanthamoeba Species in the Swimming Pools and Ponds of Khoramabad, Iran, in 2016

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    M. Faraji

    2017-10-01

    Full Text Available Background and Objective: Acanthamoeba is a free-living and opportunistic amoeba found in the water, soil, and air. This amoeba causes granulomatous amoebic encephalitis in the immunocompromised patients and amoebic keratitis in the people using contact lenses. The genotypes of Acanthamoeba are pathogenic and non-pathogenic. Regarding this, the present study aimed to determine the frequency and genotypes of Acanthamoeba in the water pools and ponds of Khorramabad, Iran, using culture, polymerase chain reaction (PCR, and sequencing methods in 2016. Materials and Methods: This study was conducted on a total of 84 water samples collected from the water pools and ponds of Khorramabad. The samples were filtered using nitrocellulose syringe (0.45 μm; subsequently, they were cultured on 1.5% non-nutrient agar, covered by killed Escherichia coli and incubated at 27ºC. After the extraction of DNA from positive samples, PCR was performed using specific primers to detect and confirm Acanthamoeba. Then, for genotyping, the PCR products of positive samples were sequenced. Results: Out of the 84 water samples, 50 (59.5% cases were positive for amoeba in the culture method. However, the results of the PCR revealed 35 (41.7% positive samples for Acanthamoeba. The sequencing of the PCR products demonstrated that 17 samples were T4 genotype (pathogen, and the rest were other Acanthamoeba genotypes. Conclusion: This study indicated the high prevalence of Acanthamoeba species, especially the pathogenic type, in the water pools of Khoramabad that could be a source of infection risk for humans. Regarding the fact that almost half of the found genotypes were pathogenic (genotype T4 that are the main cause of amoebic keratitis, these water bodies could be a potential risk factor for the public health. Therefore, the health professionals should prevent contamination.

  16. Identification of Acanthamoeba Genotypes in Pools and Stagnant Water in Ponds in Sistan Region in Southeast Iran.

    Science.gov (United States)

    Aghajani, Ali; Dabirzadeh, Mansour; Maroufi, Yahya; Hooshyar, Hossein

    2016-09-01

    Acanthamoeba is one of the most abundant free-living amoebas that is widely distributed in natural and artificial environment resources. Acanthamoeba pathogenic genotypes cause chronic human diseases including amoebic keratitis and granulomatous amoebic encephalitis. The aim of this study was to determine and identify Acanthamoeba genotypes residing in pools and stagnant water in ponds in Sistan region in southeast Iran. This descriptive study was conducted at the Parasitology Laboratory, School of Medicine, Zabol University of Medical Sciences. In this descriptive study, 93 water samples were collected from pools and ponds in Zabol, Zahak, Hirmand, Hamoon, and Nimrooz in Sistan region. Samples after filtering through 0.45-μm nitrocellulose paper filters were cultured in a 1.5% non-nutrient agar medium enriched with heat-killed Escherichia coli. Polymerase chain reaction (PCR) was conducted using specialized primers for detecting the genus Acanthamoeba. The sequencing of positive samples was used for determining Acanthamoeba genotypes. From 82 free-living amoeba positive culture samples, 38 isolates were confirmed to belong to the genus Acanthamoeba by PCR. On sequencing, 34 samples (89.47%) belonged to the T4 genotype, three (7.9%) to the T5 genotype, and one (2.63%) to the T3 genotype. All genotypes found in this study are potentially pathogenic. The T4 genotype is the main genotype of Acanthamoeba responsible for amoebic keratitis. Resource water is a potential risk factor for the distribution of free-living amoeba. Therefore, more attention of health authorities to determine, training and prevention from infection are recommended.

  17. Comparison of Fluorescence Microscopy and Different Growth Media Culture Methods for Acanthamoeba Keratitis Diagnosis.

    Science.gov (United States)

    Peretz, Avi; Geffen, Yuval; Socea, Soergiu D; Pastukh, Nina; Graffi, Shmuel

    2015-08-01

    Acanthamoeba keratitis (AK), a potentially blinding infection of the cornea, is caused by a free-living protozoan. Culture and microscopic examination of corneal scraping tissue material is the conventional method for identifying Acanthamoeba. In this article, we compared several methods for AK diagnosis of 32 patients: microscopic examination using fluorescent dye, specific culture on growth media-non-nutrient agar (NNA), culture on liquid growth media-peptone yeast glucose (PYG), and TYI-S-33. AK was found in 14 patients. Thirteen of the specimens were found AK positive by fluorescence microscopic examination, 11 specimens were found AK positive on PYG growth media, and 9 specimens were found AK positive on TYI-S-33 growth media. Only five specimens were found AK positive on NNA growth media. Therefore, we recommend using fluorescence microscopy technique and culture method, especially PYG liquid media. © The American Society of Tropical Medicine and Hygiene.

  18. Acanthamoeba keratitis associated with contact lenses; report of three cases in Italy.

    Science.gov (United States)

    Mancino, R; Iori, A; Palma, S; Corsi, A; Cancrini, G; Cerulli, L

    1997-03-01

    Three female patients, aged from 17 to 44 years, developed Acanthamoeba keratitis associated with the use of soft contact lenses and cosmetic contact lens. Two of these patients were myopic and wore soft contact lenses for optical purpose, while the third patient used a cosmetic lens. In this paper we describe the related risk factors, the success of cultural procedures and the outcome of medical management. In 2 out of the 3 cases we obtained cultures positive for Acanthamoeba, from the contact lenses and the contact-lens case. The isolated strains belong to the group II according to Pussard and Pons and they were proven pathogen for experimentally infected mice. All infections were treated successfully; however in 2 out of the 3 patients the visual acuity was reduced to the light perception.

  19. Sequence organization of the Acanthamoeba rRNA intergenic spacer: identification of transcriptional enhancers.

    Science.gov (United States)

    Yang, Q; Zwick, M G; Paule, M R

    1994-01-01

    The primary sequence of the entire 2330 bp intergenic spacer of the A.castellanii ribosomal RNA gene was determined. Repeated sequence elements averaging 140 bp were identified and found to bind a protein required for optimum initiation at the core promoter. These repeated elements were shown to stimulate rRNA transcription by RNA polymerase I in vitro. The repeats inhibited transcription when placed in trans, and stimulated transcription when in cis, in either orientation, but only when upstream of the core promoter. Thus, these repeated elements have characteristics similar to polymerase I enhancers found in higher eukaryotes. The number of rRNA repeats in Acanthamoeba cells was determined to be 24 per haploid genome, the lowest number so far identified in any eukaryote. However, because Acanthamoeba is polyploid, each cell contains approximately 600 rRNA genes. Images PMID:7984432

  20. [The German Acanthamoeba keratitis register: Initial results of a multicenter study].

    Science.gov (United States)

    Daas, L; Szentmáry, N; Eppig, T; Langenbucher, A; Hasenfus, A; Roth, M; Saeger, M; Nölle, B; Lippmann, B; Böhringer, D; Reinhard, T; Kelbsch, C; Messmer, E; Pleyer, U; Roters, S; Zhivov, A; Engelmann, K; Schrecker, J; Zumhagen, L; Thieme, H; Darawsha, R; Meyer-Ter-Vehn, T; Dick, B; Görsch, I; Hermel, M; Kohlhaas, M; Seitz, B

    2015-09-01

    In September 2011 the cornea section of the German Ophthalmological Society (DOG) established the first German Acanthamoeba keratitis registry. The data of this multicenter survey are being collected, compiled and evaluated at the Department of Ophthalmology at the Saarland University. The aim of this article is to present an intermediate report. Data from 172 eyes with Acanthamoeba keratitis were collected during the last 10 years. For this interim report we actually evaluated 121 eyes (60.2 % female patients, average age 41.3 years) and collected the following data: date of onset of symptoms, date and method of diagnosis, initial diagnosis, anamnestic data, clinical symptoms and signs at diagnosis and during follow-up, conservative and surgical therapy. Criteria for inclusion in the Acanthamoeba registry was the established diagnosis of an Acanthamoeba keratitis with at least one of the methods described in this article. Acanthamoeba keratitis could be histologically proven in 55.3 % of the cases, via PCR in 25.6 %, with confocal microscopy in 20.4 % and using in vitro cultivation in 15.5 %. Clinical symptoms and signs in Acanthamoeba keratitis were pain in 67.0 %, ring infiltrates in 53.4 %, pseudodendritiform epitheliopathy in 11.7 % and keratoneuritis in 5.8 %. In 47.6 % of the cases the initial diagnosis was herpes simplex virus keratitis followed by bacterial keratitis in 25.2 % and fungal keratitis in 3.9 %. Acanthamoeba keratitis was the correct initial diagnosis in only 23.2 % of cases. The average time period between first symptoms and diagnosis was 2.8 ± 4.0 months (range 0-23 months). A triple therapy with Brolene® Lavasept® and antibiotic eye drops at least 5 ×/day was used in 54.5 % of eyes (n = 66). Penetrating keratoplasty was performed in 40.4 %, in 18 cases in combination with cryotherapy of the cornea. The mean graft diameter was 7.9 ± 1.1 mm (range 3.5-11.0 mm). The final visual acuity (Snellen

  1. Molecular characterization of Acanthamoeba isolated from amebic keratitis related to orthokeratology lens overnight wear

    Science.gov (United States)

    Lee, Sun Joo; Jeong, Hae Jin; Lee, Ji Eun; Lee, Jong Soo; Xuan, Ying Hua; Kong, Hyun-Hee; Chung, Dong-Il; Ock, Mee-Sun

    2006-01-01

    In an effort to characterize, on the molecular scale, the Acanthamoeba initially isolated from the cornea of an amoebic keratitis patient associated with overnight-wear orthokeratology lens in Korea, we conducted mitochondrial DNA restriction fragment length polymorphism, 18S rDNA sequencing, and drug sensitivity analyses on the isolate (KA/PE1). The patient was treated with polyhexamethylene biguanide, chlorhexidine and oral itraconazole, which resulted in resolution of the patient's ocular inflammation. The majority of the molecular characteristics of the KA/PE1 were determined to be identical, or quite similar, to those of A. castellanii Ma strain, which had been isolated also from amoebic keratitis. The risk of Acanthamoeba keratitis as a potential complication of overnight orthokeratology is briefly discussed. PMID:17170573

  2. Acanthamoeba castellanii is not be an adequate model to study human adenovirus interactions with macrophagic cells.

    Science.gov (United States)

    Maisonneuve, Elodie; Cateau, Estelle; Leveque, Nicolas; Kaaki, Sihem; Beby-Defaux, Agnès; Rodier, Marie-Hélène

    2017-01-01

    Free living amoebae (FLA) including Acanthamoeba castellanii, are protozoa that feed on different microorganisms including viruses. These microorganisms show remarkable similarities with macrophages in cellular structures, physiology or ability to phagocyte preys, and some authors have therefore wondered whether Acanthamoeba and macrophages are evolutionary related. It has been considered that this amoeba may be an in vitro model to investigate relationships between pathogens and macrophagic cells. So, we intended in this study to compare the interactions between a human adenovirus strain and A. castellanii or THP-1 macrophagic cells. The results of molecular and microscopy techniques following co-cultures experiments have shown that the presence of the adenovirus decreased the viability of macrophages, while it has no effect on amoebic viability. On another hand, the viral replication occurred only in macrophages. These results showed that this amoebal model is not relevant to explore the relationships between adenoviruses and macrophages in in vitro experiments.

  3. Silencing of xylose isomerase and cellulose synthase by siRNA inhibits encystation in Acanthamoeba castellanii.

    Science.gov (United States)

    Aqeel, Yousuf; Siddiqui, Ruqaiyyah; Khan, Naveed Ahmed

    2013-03-01

    A key challenge in the successful treatment of Acanthamoeba infections is its ability to transform into a dormant cyst form that is resistant to physiological conditions and pharmacological therapies, resulting in recurrent infections. The carbohydrate linkage analysis of cyst walls of Acanthamoeba castellanii showed variously linked sugar residues, including xylofuranose/xylopyranose, glucopyranose, mannopyranose, and galactopyranose. Here, it is shown that exogenous xylose significantly reduced A. castellanii differentiation in encystation assays (P castellanii. Inhibition of both enzymes using siRNA against xylose isomerase and cellulose synthase but not scrambled siRNA attenuated A. castellanii metamorphosis, as demonstrated by the arrest of encystation of A. castellanii. Neither inhibitor nor siRNA probes had any effect on the viability and extracellular proteolytic activities of A. castellanii.

  4. Acanthamoeba castellanii is not be an adequate model to study human adenovirus interactions with macrophagic cells.

    Directory of Open Access Journals (Sweden)

    Elodie Maisonneuve

    Full Text Available Free living amoebae (FLA including Acanthamoeba castellanii, are protozoa that feed on different microorganisms including viruses. These microorganisms show remarkable similarities with macrophages in cellular structures, physiology or ability to phagocyte preys, and some authors have therefore wondered whether Acanthamoeba and macrophages are evolutionary related. It has been considered that this amoeba may be an in vitro model to investigate relationships between pathogens and macrophagic cells. So, we intended in this study to compare the interactions between a human adenovirus strain and A. castellanii or THP-1 macrophagic cells. The results of molecular and microscopy techniques following co-cultures experiments have shown that the presence of the adenovirus decreased the viability of macrophages, while it has no effect on amoebic viability. On another hand, the viral replication occurred only in macrophages. These results showed that this amoebal model is not relevant to explore the relationships between adenoviruses and macrophages in in vitro experiments.

  5. Bringing forward the new generation of alkoxy-thiourea as potential treatment for Acanthamoeba keratitis

    Science.gov (United States)

    Khairul, Wan M.; Goh, Yit-Peng; Daud, Adibah Izzati; Nakisah, M. A.

    2017-02-01

    Alkoxy substituted thiourea derivatives with general formula of A-ArC(O)NHC(S)NHAr-D which A represents the methoxy group and D denotes -OCnH2n+1 have been successfully synthesised and characterized. In turn, all the synthesised molecules were assayed for anti-amoebic activities towards Acanthamoeba sp to examine the cytotoxicity effect at their IC50 and membrane permeability. As predicted, the findings showed that the synthesised molecules owing promising anti-amoebic activity towards Acanthamoeba sp. To support, the Acridine-orange/Propidium iodide (AOPI) staining result under fluorescence microscopy revealed the treated amoeba cells by these alkoxy thiourea derivatives exhibited loss in their membrane permeability.

  6. Superdiffusion dominates intracellular particle motion in the supercrowded cytoplasm of pathogenic Acanthamoeba castellanii

    Science.gov (United States)

    Reverey, Julia F.; Jeon, Jae-Hyung; Bao, Han; Leippe, Matthias; Metzler, Ralf; Selhuber-Unkel, Christine

    2015-06-01

    Acanthamoebae are free-living protists and human pathogens, whose cellular functions and pathogenicity strongly depend on the transport of intracellular vesicles and granules through the cytosol. Using high-speed live cell imaging in combination with single-particle tracking analysis, we show here that the motion of endogenous intracellular particles in the size range from a few hundred nanometers to several micrometers in Acanthamoeba castellanii is strongly superdiffusive and influenced by cell locomotion, cytoskeletal elements, and myosin II. We demonstrate that cell locomotion significantly contributes to intracellular particle motion, but is clearly not the only origin of superdiffusivity. By analyzing the contribution of microtubules, actin, and myosin II motors we show that myosin II is a major driving force of intracellular motion in A. castellanii. The cytoplasm of A. castellanii is supercrowded with intracellular vesicles and granules, such that significant intracellular motion can only be achieved by actively driven motion, while purely thermally driven diffusion is negligible.

  7. Therapeutic agents and biocides for ocular infections by free-living amoebae of Acanthamoeba genus.

    Science.gov (United States)

    Carrijo-Carvalho, Linda Christian; Sant'ana, Viviane Peracini; Foronda, Annette Silva; de Freitas, Denise; de Souza Carvalho, Fabio Ramos

    Acanthamoeba keratitis is a sight-threatening infectious disease. Resistance of the cystic form of the protozoan to biocides and the potential toxicity of chemical compounds to corneal cells are the main concerns related to long-term treatment with the clinically available ophthalmic drugs. Currently, a limited number of recognized antimicrobial agents are available to treat ocular amoebic infections. Topical application of biguanide and diamidine antiseptic solutions is the first-line therapy. We consider the current challenges when treating Acanthamoeba keratitis and review the chemical properties, toxicities, and mechanisms of action of the available biocides. Antimicrobial therapy using anti-inflammatory drugs is controversial, and aspects related to this topic are discussed. Finally, we offer our perspective on potential improvement of the effectiveness and safety of therapeutic profiles, with the focus on the quality of life and the advancement of individualized medicine. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. The opinion of patients with inflammatory bowel disease on healthcare received Opinión de los pacientes con enfermedad inflamatoria intestinal sobre la atención sanitaria recibida

    Directory of Open Access Journals (Sweden)

    F. Casellas

    2004-03-01

    information, care of family members, and healthcare resources accessibility/agility.Fundamento: un elemento a tener en cuenta al analizar un modelo de atención sanitaria dirigido a un grupo de población afecta de una enfermedad crónica es el de los recursos sanitarios necesarios, su utilización y la valoración que tienen los usuarios de ellos. En la enfermedad inflamatoria intestinal (EII los recursos sanitarios utilizados por los enfermos son numerosos y variados, pero no han sido evaluados. Diseño: se ha realizado una encuesta autorrellenable anónima de 24 preguntas básicas a cerca de datos generales de la enfermedad, quién les controla, cómo se programan las visitas, necesidad de atención urgente, cómo creen que se puede mejorar su control, etc. La encuesta se remitió al domicilio de 393 pacientes para su contestación y se les pidió que la devolvieran por correo. Resultados: doscientos treinta y siete pacientes devolvieron la encuesta cumplimentada. La mayoría de los pacientes eran controlados en un hospital, y sólo el 8,8% lo eran por el médico de cabecera o especialista de zona. El 92% de pacientes refieren que las visitas se programan de forma rutinaria, independientemente del estado clínico. El 79,6% de pacientes refiere haber acudido alguna vez a urgencias, siendo el motivo en el 25,2% de las ocasiones no saber qué hacer o no tener otro recurso disponible. Ello explica que el 38% de visitas al servicio de urgencias se podrían haber evitado con un mejor conocimiento de la enfermedad o una consulta telefónica. El 30% de pacientes refiere que la actual atención sanitaria es inadecuada, ya sea por su contenido, la forma o el tiempo de espera. El 97,8% de pacientes cree que la información y conocimiento de la enfermedad ayudarían a su control, de forma que el 69,6% considera que con la información adecuada podrían iniciar el tratamiento ya antes de la visita médica. Otro aspecto poco atendido, y que el 74,6% de pacientes opina que ayudaría al

  9. [Genetic status of Acanthamoeba spp. Korean isolates on the basis of RAPD markers].

    Science.gov (United States)

    Hong, Y P; Oh, S H; La, M S; Im, K

    1995-12-01

    Genetic status of Acanthamoeba spp. were tested on the basis of random amplified polymorphic DNA (RAPD) marker analysis. Four previously established Acanthamoeba species, 4 Korean isolates of Acanthamoeba sp., and one American isolate of Acanthamoeba sp. were analyzed by RAPD-PCR using an arbitrary decamer primers. Amplification products were fractionated by agarose gel electrophoresis and stained by ethidium bromide. Eighteen primers produced DNA amplification profiles revealing clear differences among 4 species. Nine of them also produced DNA amplification profiles which included some isolate-specific amplification products. On the basis of amplified fragments by 18 primers, the pairwise similarity indices between A. culbertsoni and other species (i.e., A. hatchetti, A. triangularis, A. polyphaga) were 0.300, 0.308, and 0.313, respectively. Similarity index between A. hatchetti and A. triangularis was 0.833. The mean similarity index among the 3 Korean isolates (YM-2, -3, -4) was 0.959 and 0.832 among them and 2 other species (A. hatchetti and A. triangularis). The mean similarity index among YM-5 and other Korean isolates (YM-2, -3, -4) was 0.237. However, the similarity index between YM-5 and A. culbertsoni was 0.857, which suggests that YM-5 is genetically more similar to A. culbertsoni than other Korean isolates. Phenogram reconstructed by UPGMA method revealed that there are two groups: one group consists of A. hatchetti, A. triangularis, and 3 Korean isolates (YM-2, -3, -4), and the other group consists of A. culbertsoni, A. polyphaga, HOV, and YM-5.

  10. Amoebicidal efficiencies of various diamidines against two strains of Acanthamoeba polyphaga.

    Science.gov (United States)

    Perrine, D; Chenu, J P; Georges, P; Lancelot, J C; Saturnino, C; Robba, M

    1995-02-01

    The first medical cure of Acanthamoeba keratitis was obtained by use of propamidine isethionate. Since then, it has been the basic drug recommended for use in treatment. Because some Acanthamoeba strains have been reported to be resistant to propamidine and propamidine was found to be only weakly cysticidal, superior homologs such as butamidine, pentamidine, hexamidine, heptamidine, octamidine, and nonamidine were tested for their amoebicidal effects on two Acanthamoeba strains isolated from patients with keratitis. Trophozoicidal and cysticidal efficiencies were found to be increased from propamidine to nonamidine; i.e., when the alkyl chain connecting the two benzene rings in their molecular structures was elongated, in comparison with propamidine, hexamidine and octamidine were the most amoebicidal molecules. As a result of these data, a kinetic study carried out on propamidine, hexamidine, and octamidine demonstrated that the amoebicidal effects resulted from two events: the diffusion of molecules through the plasma membrane or the double wall of trophozoites or cysts, respectively, and the lethal effects of molecules on amoebic protoplasm. The diffusion kinetics were increased when the alkyl chain was elongated, i.e., with an increase in the lipophilic properties of molecules. In contrast, the lethal effect kinetics were found to be unchanged by this elongation, indicating that they originated from the cationic surface-active properties induced by the protonated amidine groups attached to each benzene ring, which themselves remained unchanged from one molecule to the other. These results strongly advocate the immediate replacement of propamidine by hexamidine in the medical treatment of Acanthamoeba keratitis; in France, 0.1% hexamidine eyedrops are available (Desomedine). The results also advocate clinical investigations on the efficiency and toxicity of octamidine, which appears to be the most amoebicidal diamidine in vitro.

  11. Occurrence of bacterial endosymbionts in Acanthamoeba spp. isolated from corneal and environmental specimens and contact lenses.

    Science.gov (United States)

    Fritsche, T R; Gautom, R K; Seyedirashti, S; Bergeron, D L; Lindquist, T D

    1993-01-01

    Free-living and parasitic protozoa are known to harbor a variety of endosymbiotic bacteria, although the roles such endosymbionts play in host survival, infectivity, and invasiveness are unclear. We have identified the presence of intracellular bacteria in 14 of 57 (24%) axenically grown Acanthamoeba isolates examined. These organisms are gram negative and non-acid fast, and they cannot be cultured by routine methodologies, although electron microscopy reveals evidence for multiplication within the amoebic cytoplasm. Examination for Legionella spp. with culture and nucleic acid probes has proven unsuccessful. We conclude that these bacteria are endosymbionts which have an obligate need to multiply within their amoebic hosts. Rod-shaped bacteria were identified in 5 of 23 clinical Acanthamoeba isolates (3 of 19 corneal isolates and 2 of 4 contact lens isolates), 4 of 25 environmental Acanthamoeba isolates, and 2 of 9 American Type Culture Collection Acanthamoeba isolates (ATCC 30868 and ATCC 30871) previously unrecognized as having endosymbionts. Coccus-shaped bacteria were present in one clinical (corneal) isolate and two environmental isolates. There was no statistical difference (P > 0.8) between the numbers of endosymbiont strains originating from clinical (26% positive) and environmental (24% positive) amoebic isolates, suggesting that the presence alone of these bacteria does not enhance amoebic infectivity. Rods and cocci were found in both clinical and environmental isolates from different geographical areas (Seattle, Wash., and Portland, Oreg.), demonstrating their widespread occurrence in nature. Our findings suggest that endosymbiosis occurs commonly among members of the family Acanthamoebidae and that the endosymbionts comprise a diverse taxonomic assemblage. The role such endosymbionts may play in pathogenesis remains unknown, although a variety of exogenous bacteria have been implicated in the development of amoebic keratitis, warranting further

  12. Identification and properties of proteases from an Acanthamoeba isolate capable of producing granulomatous encephalitis

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    Jarroll Edward L

    2006-05-01

    Full Text Available Abstract Background Granulomatous amoebic encephalitis due to Acanthamoeba is often a fatal human disease. However, the pathogenesis and pathophysiology of Acanthamoeba encephalitis remain unclear. In this study, the role of extracellular Acanthamoeba proteases in central nervous system pathogenesis and pathophysiology was examined. Results Using an encephalitis isolate belonging to T1 genotype, we observed two major proteases with approximate molecular weights of 150 KD and 130 KD on SDS-PAGE gels using gelatin as substrate. The 130 KD protease was inhibited with phenylmethylsulfonyl fluoride (PMSF suggesting that it is a serine protease, while the 150 KD protease was inhibited with 1, 10-phenanthroline suggesting that it is a metalloprotease. Both proteases exhibited maximal activity at neutral pH and over a range of temperatures, indicating their physiological relevance. These proteases degrade extracellular matrix (ECM, which provide structural and functional support to the brain tissue, as shown by the degradation of collagen I and III (major components of collagenous ECM, elastin (elastic fibrils of ECM, plasminogen (involved in proteolytic degradation of ECM, as well as casein and haemoglobin. The proteases were purified partially using ion-exchange chromatography and their effects were tested in an in vitro model of the blood-brain barrier using human brain microvascular endothelial cells (HBMEC. Neither the serine nor the metalloprotease exhibited HBMEC cytotoxicity. However, the serine protease exhibited HBMEC monolayer disruptions (trypsin-like suggesting a role in blood-brain barrier perturbations. Conclusion Overall, these data suggest that Acanthamoeba proteases digest ECM, which may play crucial role(s in invasion of the brain tissue by amoebae.

  13. Identification of Atg8 from Acanthamoeba castellanii by genetic complementation in Saccharomyces cerevisiae.

    Science.gov (United States)

    Régnacq, Matthieu; Voisin, Pierre; Héchard, Yann; Bergès, Thierry; Braquart-Varnier, Christine; Samba-Louaka, Ascel

    Autophagy is a eukaryotic process responsible for the degradation of intracellular content such as damaged organelles. Several putative autophagy-related genes have been identified within the annotated genome of the free-living amoeba Acanthamoeba castellanii. However, the involvement of the corresponding proteins in the autophagy pathway had not been formerly established. Here, we report that AcAtg8 cDNA can complement ATG8-deficient Saccharomyces cerevisiae. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Characterizing clinical isolates of Acanthamoeba castellanii with high resistance to polyhexamethylene biguanide in Taiwan.

    Science.gov (United States)

    Huang, Fu-Chin; Shih, Min-Hsiu; Chang, Kai-Fei; Huang, Jian-Ming; Shin, Jyh-Wei; Lin, Wei-Chen

    2017-10-01

    Acanthamoeba keratitis (AK), a painful infectious corneal disease, is caused by the free-living pathogenic species Acanthamoeba. The symptoms include corneal infiltrate, epithelial, and stromal destruction, and loss of vision. Current treatment generally involves an hourly application of polyhexamethylene biguanide (PHMB) over a period of several days; however, even this is not entirely effective against all strains/isolates. The aims of this study were to confirm the existence of pathogenic strains in Taiwan which are highly resistant to drugs and to characterize the behavior of these strains. An in vitro Acanthamoeba species culture platform was established to observe the effectiveness of treatment and chart the morphological changes that occur under the effects of drugs using a light microscope and time-lapse recording. Changes in gene expression were examined using reverse transcription polymerase chain reaction (RT-PCR) and real-time PCR. Over 90% of the standard strain cells (ATCC 30010) were lysed after being treated with PHMB for 1 hour; however, clinical isolates of Acanthamoeba castellanii that differed in their susceptibility to the treatment drug were only partly lysed. Following treatment with PHMB, National Cheng Kung University Hospital isolation B (NCKH_B) transformed into a pseudocyst under the effects of drug stress; however, National Cheng Kung University Hospital isolation D (NCKH_D), an isolate with higher tolerance for PHMB, did not transform. Our results confirm the existence of clinical isolates of A. castellanii with high resistance to PHMB in Taiwan and present the alternative drug tolerance of A. castellanii in addition to the transformation of pseudocyst/cyst. Copyright © 2015. Published by Elsevier B.V.

  15. A novel antiamoebic agent against Acanthamoeba sp. - A causative agent for eye keratitis infection

    Science.gov (United States)

    Kusrini, Eny; Hashim, Fatimah; Azmi, Wan Nor Nadhirah Wan Noor; Amin, Nakisah Mat; Estuningtyas, Ari

    2016-01-01

    The terbium trinitrate.trihydrate.18-crown ether-6, Tb(NO3)3(OH2)3.(18C6) complex has been characterized by elemental analysis, photoluminescence and single X-ray diffraction. The IC50 values were determined based on MTT assay while light and fluorescence microscopy imaging were employed to evaluate the cellular morphological changes. Alkaline comet assay was performed to analyze the DNA damage. The photoluminescence spectrum of the Tb complex excited at 325 nm displayed seven luminescence peaks corresponding to the 5D4 → 7F0, 1, 2, 3, 4, 5, 6 transitions. The cytotoxicity and genotoxicity studies indicated that the Tb(NO3)3(OH2)3.(18C6) complex and its salt form as well as the 18C6 molecule have excellent anti-amoebic activity with very low IC50 values are 7, 2.6 and 1.2 μg/mL, respectively, with significant decrease (p Acanthamoeba viability when the concentration was increased from 0 to 30 μg/mL. The mode of cell death in Acanthamoeba cells following treatment with the Tb complex was apoptosis. This is in contrast to the Tb(NO3)3.6H2O salt- and 18C6 molecule-treated Acanthamoeba, which exhibited necrotic type cells. The percentage of DNA damage following treatment with all the compounds at the IC25 values showed high percentage of type 1 with the % nuclei damage are 14.15 ± 2.4; 46.00 ± 4.2; 36.36 ± 2.4; 45.16 ± 0.6%, respectively for untreated, treated with Tb complex, Tb salt and 18C6 molecule. The work features promising potential of Tb(NO3)3(OH2)3.(18C6) complex as anti-amoebic agent, representing a therapeutic option for Acanthamoeba keratitis infection.

  16. A Rabbit Model of Acanthamoeba Keratitis That Better Reflects the Natural Human Infection.

    Science.gov (United States)

    Feng, Xianmin; Zheng, Wenyu; Wang, Yuehua; Zhao, Donghai; Jiang, Xiaoming; Lv, Shijie

    2015-08-01

    Acanthamoeba species are ubiquitous, free-living protozoa that can invade the cornea and result in Acanthamoeba keratitis (AK), a painful progressive sight-threatening corneal disease. Disease progression in current animal models is too rapid to mimic AK in humans accurately. This study provides a novel method for establishing AK in rabbits and compared it with the conventional method with regard to pathogenesis and immune response in humans. The New Zealand white rabbits were randomly divided into two experimental groups (Groups A and B). Rabbits in the Group A (n = 14) received intrastromal injections of 1 × 10(4) /100 µL Acanthamoeba healyi trophozoites (conventional AK model). The Group B animals (n = 14) received microinjections of 1 × 10(4) /10 µL A. healyi trophozoites between the corneal epithelium and Bowman's layer, anterior to the corneal stroma (novel AK model). In addition, two rabbits were left untreated as normal controls. AK in the treated rabbits was evaluated clinically, histopathologically, and immunologically for 35 days. AK was successfully established in both the conventional and novel model groups. Compared with the Group A, AK in the Group B displayed an efficient immune response with less severe pathology. Moreover, the self-limiting but chronic nature of the infection in the Group B was strikingly similar to that of AK in humans. The novel animal model for AK described here more closely simulates the pathogenesis and immune response of Acanthamoeba corneal infection in humans than the animal models currently in use. © 2015 Wiley Periodicals, Inc.

  17. Experimental infection of T4 Acanthamoeba genotype determines the pathogenic potential.

    Science.gov (United States)

    Alves, Daniella de Sousa Mendes Moreira; Moraes, Aline Silva; Alves, Luciano Moreira; Gurgel-Gonçalves, Rodrigo; Lino Junior, Ruy de Souza; Cuba-Cuba, César Augusto; Vinaud, Marina Clare

    2016-09-01

    T4 is the Acanthamoeba genotype most related to cases of granulomatous amoebic encephalitis (GAE) in immunocompromised patients and of keratitis in contact lens wearers. The determination of the pathogenic potential of Acanthamoeba clinical and environmental isolates using experimental models is extremely important to elucidate the capacity of free-living organisms to establish and cause disease in hosts. The aim of this study was to compare and evaluate the histopathology and culture between two different routes of experimental infection of T4 Acanthamoeba isolated from environmental and clinical source in mice (intracranial and intraperitoneal). Swiss isogenic healthy mice were inoculated with 10(4) trophozoites by intracranial (IC) and intraperitoneal (IP) routes and observed during 21 days. The brains from animals inoculated by the IC route were collected and from the animals of the IP inoculation group, the brains, livers, kidneys, spleens, and lungs were removed. The organs were prepared and appropriately divided to be evaluated with histopathology and culture. There was no significant difference between the inoculation routes in terms of isolates recovery (χ(2) = 0.09; p = 0.76). In the IC group, isolate recovery rate was significantly higher in histopathology than the one achieved by culture (χ(2) = 6.45; p Acanthamoeba in both routes. This work represents the first in vivo pathogenicity assay of primary isolation source in Central region of Brazil showing in vivo pathogenicity and hematogenous spread capacity of these protozoa, improving the knowledge on free-living amoebae isolates.

  18. Acanthamoeba Activates Macrophages Predominantly through Toll-Like Receptor 4- and MyD88-Dependent Mechanisms To Induce Interleukin-12 (IL-12) and IL-6

    Science.gov (United States)

    Cano, Antonella; Mattana, Antonella; Woods, Stuart; Henriquez, Fiona L.; Alexander, James

    2017-01-01

    ABSTRACT Acanthamoeba castellanii is a ubiquitous free-living amoeba with a worldwide distribution that can occasionally infect humans, causing particularly severe infections in immunocompromised individuals. Dissecting the immunology of Acanthamoeba infections has been considered problematic due to the very low incidence of disease, despite the high exposure rates. While macrophages are acknowledged as playing a significant role in Acanthamoeba infections, little is known about how this facultative parasite influences macrophage activity. Therefore, in this study we investigated the effects of Acanthamoeba on the activation of resting macrophages. Consequently, murine bone marrow-derived macrophages were cocultured with trophozoites of either the laboratory Neff strain or a clinical isolate of A. castellanii. In vitro real-time imaging demonstrated that trophozoites of both strains often established evanescent contact with macrophages. Both Acanthamoeba strains induced a proinflammatory macrophage phenotype characterized by the significant production of interleukin-12 (IL-12) and IL-6. However, macrophages cocultured with the clinical isolate of Acanthamoeba produced significantly less IL-12 and IL-6 than the Neff strain. The utilization of macrophages derived from MyD88-, TRIF-, Toll-like receptor 2 (TLR2)-, TLR4-, and TLR2/4-deficient mice indicated that Acanthamoeba-induced proinflammatory cytokine production was through MyD88-dependent, TRIF-independent, TLR4-induced events. This study shows for the first time the involvement of TLRs expressed on macrophages in the recognition of and response to Acanthamoeba trophozoites. PMID:28348053

  19. 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.

    Science.gov (United States)

    Rocha-Cabrera, Pedro; Reyes-Batlle, María; Martín-Navarro, Carmen María; Dorta-Gorrín, Alexis; López-Arencibia, Atteneri; Sifaoui, Ines; Martínez-Carretero, Enrique; Piñero, José E; Martín-Barrera, Fernando; Valladares, Basilio; Lorenzo-Morales, Jacob

    2015-08-01

    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.

  20. Acanthamoeba T4, T5 and T11 isolated from mineral water bottles in southern Brazil.

    Science.gov (United States)

    Maschio, Vinicius José; Chies, Fernanda; Carlesso, Ana Maris; Carvalho, Amanda; Rosa, Sayonara Peixoto; Van Der Sand, Sueli Teresinha; Rott, Marilise Brittes

    2015-01-01

    Acanthamoeba is a protist potential pathogen, capable of causing a blinding keratitis in contact lens wearers and disseminated infection, leading to granulomatous amebic encephalitis in immunocompromised individuals. This amoeba is a ubiquitous organism that has been isolated from various domestic water systems, such as cooling towers and hospital water networks. The objective of this work was to investigate the presence of Acanthamoeba in mineral water bottles marketed in Porto Alegre, southern Brazil. Positive samples were further classified at the genotype level after sequencing the ASA.S1 region of 18S rDNA gene. Six of the eight isolates belonged to T5 genotype, one to T4 genotype, and one was T11. Several genotypes have been reported worldwide as causative of pathologies in humans, including genotypes T4, T5 and T11. Overall, the widespread distribution of potentially pathogenic Acanthamoeba strains in the studied source demands more awareness within the public and health professionals, because this pathogen is emerging as a risk for human health worldwide.

  1. The amino acid sequence of the light chain of Acanthamoeba myosin IC.

    Science.gov (United States)

    Wang, Z Y; Sakai, J; Matsudaira, P T; Baines, I C; Sellers, J R; Hammer, J A; Korn, E D

    1997-06-01

    The amino acid sequence of the light chain of Acanthamoeba myosin IC deduced from the cDNA sequence comprises 149 amino acids with a calculated molecular weight of 16,739. All but the 3 N-terminal residues were also determined by amino acid sequencing of the purified protein, which also showed the N-terminus to be blocked. Phylogenetic analysis shows Acanthamoeba myosin IC light chain to be more similar to the calmodulin subfamily of EF-hand calcium-modulated proteins than to the myosin II essential light chain or regulatory light chain subfamilies. In pairwise comparisons, the myosin IC light chain sequence is most similar to sequences of calmodulins (approximately 50% identical) and a squid calcium-binding protein (approximately 43% identical); the sequence is approximately 37% identical to the calcium-binding essential light chain of Physarum myosin II and approximately 30% identical to the essential light chain of Acanthamoeba myosin II, and the essential light chain and regulatory light chain of Dictyostelium myosin II. The sequence predicts four helix-loop-helix domains with possible calcium-binding sites in domains I and III, suggesting that calcium may affect the activity of this unconventional myosin. This is the first report of the sequence of an unconventional myosin light chain other than calmodulin.

  2. Effect of adhered bacteria on the binding of Acanthamoeba to hydrogel lenses.

    Science.gov (United States)

    Gorlin, A I; Gabriel, M M; Wilson, L A; Ahearn, D G

    1996-05-01

    To determine the effect of Pseudomonas aeruginosa and Staphylococcus epidermidis on the binding of Acanthamoeba species to hydrogel lenses. Cells of amebae and bacteria were incubated with different types of hydrogel lenses. Densities of amebae that were bound to the lenses after rinsing were determined from direct counts with a cell detachment procedure and from scintillation counts of cells, which were radiolabeled with tritiated leucine. With both methods, amebae showed significantly increased binding to hydrogel lenses with attached P aeruginosa. The numbers of amebae that were retained on lenses with attached S epidermidis were not significantly different from those that were retained on lenses without bacteria. The binding of amebae to unworn hydrogel lenses, in contrast to the irreversible adherence of P aeruginosa, was tenuous. The binding of Acanthamoeba species to unworn hydrogel lenses was tenuous and appeared to be related to water content, surface tensions, and ionic charge. The presence of adhered P aeruginosa on the hydrogel lenses facilitated the binding of Acanthamoeba species. The cocontamination of lens systems with bacteria (eg, P aeruginosa) may be a prime factor in the development of amebic keratitis.

  3. Isolation of genomic DNA encoding transcription factor TFIID from Acanthamoeba castellanii: characterization of the promoter.

    Science.gov (United States)

    Wong, J M; Liu, F; Bateman, E

    1992-01-01

    We have isolated a genomic clone encoding Acanthamoeba castellanii TFIID. The clone contains the entire TFIID gene, 300 bp of 5' promoter sequences and several hundred base pairs of 3' non-coding sequence. The coding region is interrupted by two short introns, but is otherwise identical to Acanthamoeba TFIID cDNA. Comparisons between forty four Acanthamoeba intron 5' and 3' boundaries suggest a 5' splice site consensus of GTACG(T/C) and a 3' consensus of CAG. We determined the position of the transcription initiation site used in vivo, and show that the same site is used in vitro by homologous nuclear extracts. Deletion analysis of the promoter region shows that the minimal promoter required for efficient expression in vitro is located between -97 and +4 relative to the transcription start site. Three regions within the promoter are important for transcription in vitro; sequences between -97 and -35, the TATAAA box and the initiation region. The initiation region is dispensable but appears to position the transcription start site relative to the TATAAA box. The TATAAA box is absolutely required for transcription initiation whereas the upstream region stimulates transcription approximately five-fold. Images PMID:1408796

  4. In vitro interactions of Acanthamoeba castellanii Neff and Vibrio harveyi.

    Science.gov (United States)

    Reyes-Batlle, María; Martín-Rodríguez, Alberto J; López-Arencibia, Atteneri; Sifaoui, Ines; Liendo, Aitor Rizo; Bethencourt Estrella, Carlos J; García Méndez, Ana B; Chiboub, Olfa; Hajaji, Soumaya; Valladares, Basilio; Martínez-Carretero, Enrique; Piñero, José E; Lorenzo-Morales, Jacob

    2017-12-01

    Free-living amoebae (FLA) are opportunistic protozoa widely distributed in the environment. They are frequently found in water and soil samples, but they have also been reported to be associated with bacterial human pathogens such as Legionella spp. Campylobacter spp or Vibrio cholerae among others. Including within Vibrio spp. V. harveyi (Johnson and Shunk, 1936) is a bioluminescent marine bacteria which has been found swimming freely in tropical marine waters, being part of the stomach and intestine microflora of marine animals, and as both a primary and opportunistic pathogen of marine animals. Our aim was to study the interactions between Vibrio harveyi and Acanthamoeba castellanii Neff. Firstly, in order to analyze changes in it cultivability, V. harveyi was coincubated with A. castellanii Neff axenic culture and with Acanthamoeba Conditioned Medium (ACM) at different temperatures in aerobic conditions. Interestingly, at 4 °C and 18-20 °C bacteria were still cultivable in marine agar, at 28 °C, in aerobic conditions, but there weren't significant differences comparing with the controls. We also noted an enhanced migration of Acanthamoeba toward V. harveyi on non-nutrient agar plates compared to controls with no bacteria. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. A Multiplex Dot Hybridization Assay For Detection and Differentiation of Acanthamoeba and Herpes Keratitis.

    Science.gov (United States)

    Kuo, Ming-Tse; Fang, Po-Chiung; Yu, Hun-Ju; Chao, Tsae-Ling; Chien, Chun-Chih; Chen, Shun-Hua; Wang, Jen-Ren; Tseng, Shin-Ling; Lai, Yu-Hsuan; Hsiao, Chang-Chun; Chang, Tsung C

    2016-04-01

    We verified a multiplex dot hybridization (MDH) assay for the rapid detection and differentiation of Acanthamoeba keratitis (AK) and herpes simplex keratitis (HSK). Molecular detection of Acanthamoeba and herpes simplex virus in corneal scrapes was performed with the MDH assay and standard diagnostic methods. The experimental group included corneal scrapes (n = 33) from patients with culture- or pathology-confirmed AK (n = 15) and real-time PCR-confirmed HSK (n = 16). The control group included 50 samples from cases of bacterial keratitis (n = 15), fungal keratitis (n = 15), and initially presumed AK (n = 5) or HSK (n = 17) which finally were excluded by culture for Acanthamoeba or by real-time PCR for herpes simplex virus, respectively. Discrepant results between methods were resolved by DNA sequencing of the PCR amplicons. After discrepant analysis, the sensitivity for the diagnosis of AK and HSK was both 93.3% by the MDH assay, while the specificity was 100% for the two types of keratitis. The turnaround time of MDH assay was within a working day using an already prepared array. Two false-negatives (one AK case and one HSK case) were obtained by the MDH assay. The MDH assay could effectively prevent missed or delayed diagnosis of AK and HSK and has a potential to be adopted in routine clinical practice if the test is commercialized.

  6. Concurrent acanthamoeba and Fusarium keratitis with silicone hydrogel contact lens use.

    Science.gov (United States)

    Lee, Barry; Grossniklaus, Hans E; Edelhauser, Henry F

    2010-02-01

    To report a case of simultaneous Acanthamoeba and Fusarium keratitis associated with no-rub multipurpose contact lens solution and silicone hydrogel contact lens use. Observational case report. A 39-year-old woman was referred for worsening of a presumed bacterial corneal ulcer in the setting of silicone hydrogellens wear with occasional overnight wear, no-rub multipurpose contact lens solution use, and combined topical antibiotic/corticosteroid treatment. Initial corneal scrapings and culture confirmed Acanthamoeba and Fusarium solani, corroborated by in vivo confocal microscopy findings, yet despite topical chlorhexidine 0.02%, propamidine 1%,neomycin/polymyxin B ointment, and natamycin 5% along with oral itraconazole, the ulcer worsened. Four days after amoebic and fungal therapy initiation, it was discovered that the pharmacy accidentally dispensed neomycin/polymyxin B/dexamethasone, and despite immediate discontinuation, therapeutic penetrating keratoplasty from corneal melting was ultimately required. Corneal histopathology confirmed the presence of amoebic cysts and fungal elements. Coexisting infection with Acanthamoeba and Fusarium species can occur in contact lens wear. Atypical infection must be considered in patients with corneal ulcers demonstrating poor therapeutic response in the setting of contact lens wear. Corticosteroids should be used with extreme caution in contact lens–related corneal infections, especially when the diagnosis remains unknown because they can lead to acceleration of active infection and keratolysis.

  7. Variation in Campylobacter jejuni culturability in presence of Acanthamoeba castellanii Neff.

    Science.gov (United States)

    Reyes-Batlle, María; Girbau, Cecilia; López-Arencibia, Atteneri; Sifaoui, Ines; Liendo, Aitor Rizo; Bethencourt Estrella, Carlos J; García Méndez, Ana B; Chiboub, Olfa; Hajaji, Soumaya; Fernández-Astorga, Aurora; Valladares, Basilio; Martínez-Carretero, Enrique; Piñero, José E; Lorenzo-Morales, Jacob

    2017-12-01

    Free-living amoebae (FLA) are protozoa that are widely distributed in the environment mainly in water and soil related habitats. These amoebae have also been reported to be associated with some bacterial pathogens for humans such as Campylobacter spp. The species C. jejuni is the causative agent of about 90% of human campylobacteriosis cases worldwide and this disease may even end up in severe autoimmune sequelae as Guillain-Barré syndrome (GBS). In this study, the interactions between the strain Acanthamoeba castellanii Neff and Campylobacter jejuni was investigated. Campylobacter jejuni was coincubated with Acanthamoeba castellanii Neff trophozoites at different temperatures, in order to evaluate the C. jejuni ability to grow in presence A. castellanii culture and Acanthamoeba Conditioned Medium (ACM). C. jejuni was coincubated with A. castellanii axenic culture at different temperatures in aerobic conditions. Our results revealed that bacteria were still cultivable (Blood Agar medium, at 37 °C, in microaerophilic atmosphere) after a 14 days C. jejuni - A. castellanii coculture, comparing with C. jejuni alone, which was only cultivable for 24 h. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Caspase-like proteins: Acanthamoeba castellanii metacaspase and Dictyostelium discoideum paracaspase, what are their functions?

    Science.gov (United States)

    Saheb, Entsar; Trzyna, Wendy; Bush, John

    2014-12-01

    Caspases are cysteine proteases that are important regulators of programmed cell death in animals. Two novel relatives to members of the caspase families metacaspases and paracaspase have been discovered. Metacaspase type-1 was identified in Acanthamoeba castellanii, an opportunistic protozoan parasite that causes severe diseases in humans. Paracaspase was found in the non-pathogenic protozoan Dictyostelium discoideum. Since their discovery in Acanthamoeba and Dictyostelium, metacaspases and paracaspases have remained poorly characterized. At present we do not have sufficient data about the molecular function of these caspase-like proteins or their role, if any, in programmed cell death. How these caspase proteins function at the molecular level is an important area of study that will provide insight into their potential for treatment therapies against Acanthamoeba infection and other similar parasitic protozoan. Additionally, finding the molecular functions of these caspase-like proteins will provide information concerning their role in more complex organisms.The aim of this article was to review recent discoveries about metacaspases and paracaspases as regulators of apoptotic and non-apoptot