Occurrence of Arcellidae (Amorphea, Arcellinida) in a coastal stream in the State of Rio de Janeiro

The aim of this study was to elaborate a taxonomic survey on the testate amoebae of the Family Arcellidaein coastal streams in the State of Rio de Janeiro. Six samplingswere conducted in Ubatiba coastal stream (Maricá, RJ). In total, 130 liters water were filtered through a conical net of 60-μm mesh and preserved in 4% formalin. Organisms were identified with the aid of an inverted trinocular microscope. The morphological characteristics (lobose testate amoebae with shell composed of granular chitinoid elements) of each species were recorded. The species were described and illustrated. For the verification of new taxa records of Arcellidae in Rio de Janeiro and their distribution in Brazil, a search based on indexarticles by Scopus, Web of Science and Google Scholar using the keywords "tecamebas", "testate amoebae", "Arcella", "Arcellidae", "Brazil" and "Rio de Janeiro", was performed. Eight Arcellidaespecies were recorded. Some ecological and taxonomic information was provided. Due to the small amount of information on testate amoebae, this study is important because it reduces the knowledge gap regarding this community in the State of Rio de Janeiro. Furthermore, we suggest new studies on species identification to be conducted to expand regional knowledge about these organisms.

Infecciones por amebas de vida libre. Comentarios históricos, taxonomía y nomenclatura, protozoología y cuadros anátomo-clínicos / Infections caused by free-living amebas: historical commentaries, taxonomy and nomenclature, protozoology and clinicopathologic features

Infections caused by free-living amebae constitute one of emergent opportunistic infections with greatest medical interest. Although infrequently, they have been described in almost all world, its diagnosis depends on a high index of suspicion, especially in morpho-pathologic and laboratory studies. Exciting historical features of infections due to free-living amebae, its taxonomy and the present nomenclature are briefly reviewed. An analysis of the protozoology of the most frequent agents is done and, based on the author's own experience and the published one, already established anatomo-clinical entities are described: the primary amebic meningoencephalitis, granulomatous amebic encephalitis, Acanthamoeba keratitis, cutaneous acanthamoebiasis, disseminated infection and other rare isolated locations.

Encefalitis amebiana granulomatosa por Balamuthia mandrillaris. Primer caso diagnosticado en Chile / Granulomatous amebic encephalitis caused by Balamuthia mandrillaris: first case diagnosed in Chile

Se presenta el caso de un lactante de sexo masculino de 7 meses de vida con una historia de varias semanas de evolución caracterizada por convulsiones, fiebre y cambios conductuales. Hospitalizado, la tomografía axial computada de cerebro mostró lesiones multifocales de algunos mm a 4 cm de diámetro, sin efecto de masa, y una biopsia de las mismas reveló una encefalitis necrotizante con arteritis necrótica fibrinoide. A pesar del tratamiento, las lesiones progresaron y el niño falleció. La necropsia demostró una extensa encefalitis necrotizante, multifocal, con arteritis necrótica fibrinoide, algunos signos de organización, y la presencia de elementos parasitarios con caracteres de trofozoitos y quistes de amebas de vida libre del género Acanthamoeba o Balamuthia. Además, se constató una hipoplasia- displasia del timo y signos de schok. Los elementos encontrados corresponden al cuadro descrito como encefalitis amebiana granulomatosa y el agente encontrado fue tipificado, (Centers for Disease Control and Prevention, Atlanta, USA) correspondiendo a la especie Balamuthia mandrillaris.

Meningoencefalitis granulomatosa por Balamuthia mandrillaris: Reporte de un caso y revisión de la literatura / Granulomatous amoebic meningoencephalitis by Balamuthia mandrillaris: case report and literature review

Durante los últimos años, otra ameba de vida libre, Balamuthia mandrillaris, ha sido identificada como agente etiológico de meningoencefalitis granulomatosa amebiana (MGA) en humanos. Presentamos el caso de una escolar de sexo femenino, inmunocompetente en quien se realizó el diagnóstico post mortem de MGA por este agente. Consultó por aparición de lesiones eritematosas e induradas que comprometían la zona centro-facial. En biopsia cutánea se evidenció una lesión granulomatosa con RPC positiva para secuencias génicas de Mycobacterium atípico, por lo que se inició tratamiento para micobacteriosis atípica extrapulmonar. Evolucionó con compromiso neurológico progresivo, falleciendo aproximadamente un año después de iniciar los síntomas. La necropsia reveló una MGA, cuyo estudio posterior demostró la presencia de B. mandrillaris. La infección por B. mandrillaris debe ser considerada en el diagnóstico diferencial de una enfermedad granulomatosa crónica que evoluciona con compromiso neurológico.

A brief survey of free-living amebae in Thailand and Hamamatsu District, Japan.

The aim of this study was to determine the presence of free-living amebae in aquatic habitats of human environments in Thailand and Hamamatsu district, Japan. Genus identification was based on the morphology of cyst and trophozoite forms and a flagellation test for genus Naegleria. The pathogenic potential was tested in mice by nasal instillation for genus Naegleria and Acanthameba. In 14 provinces of Thailand, amebae were isolated in 43 from 95 water samples and 67 from 120 soil swabs. Amebae of 49 isolates from waters were identified as Acanthameba (36.7%), Naegleria (28.6%), Hartmannella (20.4%), Vahlkampfia (12.2%) and Vannella (2%). Soil samples have significantly higher levels of Acanthameba and Hartmannella (p<0.05) but lower for Naegleria (p<0.05) and 7 unidentified amebae were found. In Hamamatsu district, Japan, 62 amebae of the same genera were isolated from 47 of 95 water samples. There were significantly higher levels of Acanthameba (22.6%) (p<0.05) but lower for Naegleria (4.8%) (p<0.05) than those of Thailand which each of them caused death in mice. Three unidentified amebae were isolated. This finding serves as additional evidence for the presence of free-living amebae under natural and the difference in distribution between tropic and subtropic areas.