[Acanthamoeba spp. as opportunistic pathogens parasites]. / Acanthamoeba spp. como parásitos patógenos y oportunistas.

Among free-living amoeba in nature, species of the genus Acanthamoeba have been associated with human disease. These amoeba are among the most abundant protozoa in nature due to its cosmopolitan distribution and are able to survive in a wide variety of habitats because its low demand for food and in harsh environments by forming structures known as cysts. However, ecological changes and incursion of its different habitats have made this organism can invade a host and live as parasites within him. That's why this type of protozoa are known as amphizoic organism, because human can be constituted as its host, causing infections in the central nervous system, disseminated infections in skin and lungs, and keratitis. Thus, since an increase in the number of cases of Acanthamoeba infections has occurred worldwide, these protozoa have become increasingly important as agents of human disease. This review summarizes what is known of this kind of free-living amoeba, focusing on the biology, ecology, pathogenesis, diagnosis, treatment and human defense mechanism against infection by the amoeba.

Natural Products with Inhibitory Activity against Human Immunodeficiency Virus Type 1.

Infections caused by human immunodeficiency virus (HIV) are considered one of the main public health problems worldwide. Antiretroviral therapy (ART) is the current modality of treatment for HIV-1 infection. It comprises the combined use of several drugs and can decrease the viral load and increase the CD4+ T cell count in patients with HIV-1 infection, thereby proving to be an effective modality. This therapy significantly decreases the rate of morbidity and mortality owing to acquired immunodeficiency syndrome (AIDS) and prolongs and improves the quality of life of infected patients. However, nonadherence to ART may increase viral resistance to antiretroviral drugs and transmission of drug-resistant strains of HIV. Therefore, it is necessary to continue research for compounds with anti-HIV-1 activity, exhibiting a potential for the development of an alternative or complementary therapy to ART with low cost and fewer side effects. Natural products and their derivatives represent an excellent option owing to their therapeutic potential against HIV. Currently, the derivatives of natural products available as anti-HIV-1 agents include zidovudine, an arabinonucleoside derivative of the Caribbean marine sponge (Tectitethya crypta), which inhibits the reverse transcriptase of the virus. This was the first antiviral agent approved for treatment of HIV infection. Additionally, bevirimat (isolated from Syzygium claviflorum) and calanolide A (isolated from Calophyllum sp.) are inhibitors of viral maturation and reverse transcription process, respectively. In the present review, we aimed to describe the wide repertoire of natural compounds exhibiting anti-HIV-1 activity that can be considered for designing new therapeutic strategies to curb the HIV pandemic.

In vitro anti-HIV-1 activity of the enzymatic extract enriched with laccase produced by the fungi Ganoderma sp. and Lentinus sp / Actividad anti-VIH-1 in vitro del extracto enzimático enriquecido con lacasa producido por los hongos Ganoderma sp. y Lentinus sp

Background: Natural compounds are a good source for the development of antiretroviral drugs with low cytotoxicity. The laccase enzyme, produced by fungi of the genera Ganoderma sp. and Lentinus sp., inhibits the reverse transcriptase (RT) of the human immunodeficiency virus 1 (HIV-1), in cell-free models in vitro. Objetives: In this study we evaluated the anti-HIV-1 activity of the enzymatic extracts (EE) enriched with laccase, produced by two native species of fungi of the same genera in an in vitro cell culture model. Methods: The inhibition of viral replication was performed using the U373-MAGI cell line infected with recombinant viruses in the presence/absence of the EE and 48 hpi, the percentage of infected cells was evaluated by flow cytometry for green fluorescent protein ­GFP­ and ELISA for p24. The inhibition of the RT was determined by quantification of early and late products of reverse transcription using quantitative PCR. Results: The EEs from Ganoderma sp. and Lentinus sp. inhibited the replication of HIV-1 between 80 and 90% and decreased the production of early and late transcripts between 55,5%-91,3% and 82,1%-93,6% respectively. The EE from Lentinus sp. had the best selectivity index (SI: 8.3). Conclusions: These results suggest the potential anti-HIV-1 activity of the EE for the exploration of an alternative therapy against HIV-1 infection.

Antecedentes: Los compuestos naturales son una buena fuente para el desarrollo de fármacos antirretrovirales con baja citotoxicidad. La enzima lacasa, producida por hongos del género Ganoderma sp. y Lentinus sp., inhibe la transcriptasa reversa (TR) del virus de la inmunodeficiencia humana tipo 1 (VIH-1), en modelos in vitro, libres de células. Objetivos: En este estudio se evaluó la actividad anti-VIH-1 del extracto enzimático (EE) enriquecido con lacasa, producida por dos especies nativas de hongos de los mismos géneros en un modelo in vitro de cultivo celular. Métodos: La inhibición de la replicación viral se realizó usando la línea celular U373-MAGI infectada con virus recombinantes en la presencia/ ausencia del EE y 48 hpi, el porcentaje de células infectadas se evaluó mediante citometría de flujo para GFP y ELISA para p24. La inhibición de la TR se determinó mediante la cuantificación de los productos tempranos y tardíos de la transcripción reversa utilizando una PCR cuantitativa. Resultados: El EE de Ganoderma sp. y Lentinus sp. inhibió la replicación del VIH-1 entre el 80 y 90% y disminuyó la producción de transcriptos tempranos y tardíos entre el 55,5% -91,3% y 82,1% -93,6%, respectivamente. El EE de Lentinus sp. mostró el mejor índice de selectividad (IS: 8.3). Conclusiones: Estos resultados sugieren el potencial anti-VIH-1 del EE para la exploración de una terapia alternativa contra la infección por el VIH-1.

Acanthamoeba spp. como parásitos patógenos y oportunistas / Acanthamoeba spp. as opportunistic pathogens parasites

Among free-living amoeba in nature, species of the genus Acanthamoeba have been associated with human disease. These amoeba are among the most abundant protozoa in nature due to its cosmopolitan distribution and are able to survive in a wide variety of habitats because its low demand for food and in harsh environments by forming structures known as cysts. However, ecological changes and incursion of its different habitats have made this organism can invade a host and live as parasites within him. That's why this type of protozoa are known as amphizoic organism, because human can be constituted as its host, causing infections in the central nervous system, disseminated infections in skin and lungs, and keratitis. Thus, since an increase in the number of cases of Acanthamoeba infections has occurred worldwide, these protozoa have become increasingly important as agents of human disease. This review summarizes what is known of this kind of free-living amoeba, focusing on the biology, ecology, pathogenesis, diagnosis, treatment and human defense mechanism against infection by the amoeba.

Entre las amebas de vida libre (AVL) que existen en la naturaleza, las especies pertenecientes al género Acantha-moeba han sido asociadas a enfermedades en humanos. Las AVL están entre los protozoos más abundantes en la naturaleza debido a su distribución cosmopolita y a que pueden sobrevivir en una amplia variedad de hábitats, incluyendo ambientes inhóspitos, gracias a su poca demanda de alimento y a que puede formar estructuras conocidas como quistes que las hacen resistentes. Los cambios ecológicos y la incursión de sus diferentes hábitats, han hecho que puedan invadir un hospedero y vivir como parásitos dentro de él. Por esto, este protozoo se conoce como un microorganismo anfizoico, ya que el hombre puede llegar a constituirse como su hospedero, causando infecciones en el sistema nervioso central, infecciones diseminadas en piel y pulmones, y queratitis. Es así como desde el incremento en el número de infecciones reportadas en el mundo por Acanthamoeba, estos protozoos se han convertido en importantes agentes de enfermedades en el hombre. En esta revisión se resume lo que se conoce de este género de AVL, enfocándose en su biología, patogénesis y los mecanismos de defensa humano frente a la infección por Acanthamoeba.