Antiviral Activity of an Indole-Type Compound Derived from Natural Products, Identified by Virtual Screening by Interaction on Dengue Virus NS5 Protein.

Dengue is an acute febrile illness caused by the Dengue virus (DENV), with a high number of cases worldwide. There is no available treatment that directly affects the virus or the viral cycle. The objective of this study was to identify a compound derived from natural products that interacts with the NS5 protein of the dengue virus through virtual screening and evaluate its in vitro antiviral effect on DENV-2. Molecular docking was performed on NS5 using AutoDock Vina software, and compounds with physicochemical and pharmacological properties of interest were selected. The preliminary antiviral effect was evaluated by the expression of the NS1 protein. The effect on viral genome replication and/or translation was determined by NS5 production using DENV-2 Huh-7 replicon through ELISA and viral RNA quantification using RT-qPCR. The in silico strategy proved effective in finding a compound (M78) with an indole-like structure and with an effect on the replication cycle of DENV-2. Treatment at 50 µM reduced the expression of the NS5 protein by 70% and decreased viral RNA by 1.7 times. M78 is involved in the replication and/or translation of the viral genome.

Vigilancia ambiental de la circulación de poliovirus en tres municipios considerados como punto transitorio de migrantes en Colombia 2017-2019 / Environmental surveillance of the circulation of poliovirus in municipalities considered as transitory point of migrants in Colombia 2017-2019

Resumen Objetivo: Determinar la circulación de poliovirus en tres municipios considerados como punto transitorio de migrantes en Colombia. Material y método: Se colectaron muestras de aguas residuales (n=36) de municipios fronterizos, seleccionados por mayor tránsito de migrantes regulares como irregulares, en el periodo comprendido entre el 2017-2019. Las muestras fueron concentradas y cultivadas siguiendo el algoritmo de vigilancia ambiental para la circulación de poliovirus de la Organización Mundial de la Salud (OMS). La identificación molecular se realizo mediante reacción en cadena de la polimerasa empleando cebadores específicos de grupo, de serotipo y de cepa vacunal sabin. Resultados y Discusión: Se detectó la presencia de Enterovirus no polio (EVNP) en las muestras ambientales obtenidas y no se hallo circulación de poliovirus deriva dos de la vacuna ni de poliovirus salvaje en los tres municipos evaluados; sin embargo en dos estudios previos publicados por Gonzalez y col con una metodologia similar en el año 2005 y 2015 evaluando las aguas residuales de la ciudad de Armenia-Quindio; se logró identificar la presencia de virus derivado de vacuna, con resultados negativos para la identificación de poliovirus salvaje. Conclusiones: Los hallazgos indican que el sistema de monitoreo de aguas residuales con el fin de determinar la presencia de virus es una herramienta util para realizar vigilancia ambiental.

Abstract Objective: To determine the circulation of poliovirus in three municipalities considered as transitory points for migrants in Colombia. Material and Method: Wastewater samples (n = 36) were collected from border municipalities, selected for greater transit of regular and irregular migrants, in the period between 2017-2019. The samples were concentrated and cultured following the World Health Organization (WHO) environmental surveillance algorithm for poliovirus circulation. Molecular identification was performed by polymerase chain reaction using group-specific, serotype and sabin vaccine strain primers. Results: The presence of non-polio Enterovirus (NPV) was detected in the environmental samples obtained and no circulation of poliovirus derived from the vaccine or wild poliovirus was found in the three evaluated municipalities; However, in two previous studies published by Gonzales et al with a similar methodology in 2005 and 2015 evaluating the wastewater of the city of Armenia-Quindío; It was possible to identify the presence of virus derived from vaccine, with negative results for the identification of wild poliovirus. Conclusions: The findings indicate that the wastewater monitoring system in order to determine the presence of viruses is a useful tool to carry out environmental surveillance.

Hepatitis E Virus: A review of the current status and perspectives / Virus de la Hepatitis E; revisión del estado actual y perspectivas

Abstract Hepatitis E virus produces approximately 20-million infections per year; symptomatic cases are over 3-million and deaths are approximately 60,000. Generally, it is self-limited; however, it can cause up to 30% mortality in pregnant women and can be chronic in immunosuppressed people. The transmission path of the Hepatitis E virus is principally fecal-oral, especially in developing countries; in industrialized countries, it is transmitted as a zoonosis, through organ transplants or blood transfusions. The vaccine developed is only licensed in China. Currently, no treatment is available for the HEV infection and work is underway in identifying the viral cycle and the immune response. This article sought to offer a review of the theme on the hepatitis E virus, from the last six years, to describe current general aspects of the Hepatitis E virus, genome, ways of transmission and contribute to its visibility for its prevention and control.

Resumen El virus de la hepatitis E produce aproximadamente 20 millones de infecciones por año; los casos sintomáticos superan los 3 millones y las muertes son apro ximadamente 60.000. Generalmente es autolimitada; sin embargo, puede causar hasta un 30% de mortalidad en mujeres embarazadas y puede ser crónica en personas inmunodeprimidas. La vía de transmisión del virus de la hepatitis E, es principalmente fecal-oral; especialmente en los países en desarrollo. En los países industrializados, se transmite como zoonosis, a través de trasplantes de órganos o transfusiones sanguíneas. La vacuna desarrollada solo tiene licencia en China. Actualmente, no hay tratamiento disponible para la infección por HEV y se está trabajando para identificar el ciclo viral y la respuesta inmune. Este artículo buscó ofrecer una revisión del tema sobre el virus de la hepatitis E, de los últimos seis años, para describir aspectos del virus de la Hepatitis E, genoma, vías de transmisión y contribuir a su visibilidad para su prevención y control.

PD1 CD44 antiviral peptide as an inhibitor of the protein-protein interaction in dengue virus invasion.

Dengue virus (DENV) infection is mediated by the interaction between the virus envelope protein and cellular receptors of the host cells. In this study, we designed peptides to inhibit protein-protein interaction between dengue virus and CD44 receptor, which is one of the receptors used by DENV for entry. In silico model complexes were designed between domain III of the viral envelope protein of dengue virus 2 and the domain of human CD44 receptor using ClusPro 2.0, (https://cluspro.bu.edu/login.php), and inhibition peptides were designed with Rosetta Online-Server(http://rosie.rosettacommons.org/peptiderive). We identified one linear antiviral peptide of 18 amino acids derived from the human CD44 receptor, PD1 CD44. It did not show hemolysis or toxicity in HepG2 or BHK cell lines, nor did it stimulate the release of IL-1ß, IL-6, TNF-α, and IFN-γ, below 100 µM. It had an IC50 of 13.8 µM and maximum effective dose of 54.9 µM evaluated in BHK cells. The decrease in plaque-forming units/mL for DENV1, DENV2, DENV3, and DENV4 was 99.60%, 99.40%, 97.80%, and 70.50%, respectively, and similar results were obtained by RT-qPCR. Non-structural protein 1 release was decreased in pre- and co-treatment but not in post-treatment. Competition assays between the DN59 peptide, envelope protein, and the fragment of domain III "MDKLQLKGMSYSMCTGKF" of the viral envelope of DENV2 and PD1 CD44 showed that our peptide lost its antiviral activity. We demonstrated that our peptide decreased endosome formation, and we propose that it binds to the envelope protein of DENV, inhibiting viral invasion/fusion.

In Vitro Inhibition of Replication of Dengue Virus Serotypes 1-4 by siRNAs Bound to Non-Toxic Liposomes.

Dengue virus is a ssRNA+ flavivirus, which produces the dengue disease in humans. Currently, no specific treatment exists. siRNAs regulate gene expression and have been used systematically to silence viral genomes; however, they require controlled release. Liposomes show favorable results encapsulating siRNA for gene silencing. The objective herein was to design and evaluate in vitro siRNAs bound to liposomes that inhibit DENV replication. siRNAs were designed against DENV1-4 from conserved regions using siDirect2.0 and Web-BLOCK-iT™ RNAiDesigner; the initial in vitro evaluation was carried out through transfection into HepG2 cells. siRNA with silencing capacity was encapsulated in liposomes composed of D-Lin-MC3-DMA, DSPC, Chol. Cytotoxicity, hemolysis, pro-inflammatory cytokine release and antiviral activity were evaluated using plaque assay and RT-qPCR. A working concentration of siRNA was established at 40 nM. siRNA1, siRNA2, siRNA3.1, and siRNA4 were encapsulated in liposomes, and their siRNA delivery through liposomes led to a statistically significant decrease in viral titers, yielded no cytotoxicity or hemolysis and did not stimulate release of pro-inflammatory cytokines. Finally, liposomes were designed with siRNA against DENV, which proved to be safe in vitro.

New Insect Host Defense Peptides (HDP) From Dung Beetle (Coleoptera: Scarabaeidae) Transcriptomes.

The Coleoptera Scarabaeidae family is one of the most diverse groups of insects on the planet, which live in complex microbiological environments. Their immune systems have evolved diverse families of Host Defense Peptides (HDP) with strong antimicrobial and immunomodulatory activities. However, there are several peptide sequences that await discovery in this group of organisms. This would pave the way to identify molecules with promising therapeutic potential. This work retrieved two sources of information: 1) De-novo transcriptomic data from two species of neotropical Scarabaeidae (Dichotomius satanas and Ontophagus curvicornis); 2) Sequence data deposited in available databases. A Blast-based search was conducted against the transcriptomes with a subset of sequences representative of the HDP. This work reports 155 novel HDP sequences identified in nine transcriptomes from seven species of Coleoptera: D. satanas (n = 76; 49.03%), O. curvicornis (n = 23; 14.83%), (Trypoxylus dichotomus) (n = 18; 11.61%), (Onthophagus nigriventris) (n = 10; 6.45%), (Heterochelus sp) (n = 6; 3.87%), (Oxysternon conspicillatum) (n = 18; 11.61%), and (Popillia japonica) (n = 4; 2.58%). These sequences were identified based on similarity to known HDP insect families. New members of defensins (n = 58; 37.42%), cecropins (n = 18; 11.61%), attancins (n = 41; 26.45%), and coleoptericins (n = 38; 24.52%) were described based on their physicochemical and structural characteristics, as well as their sequence relationship to other insect HDPs. Therefore, the Scarabaeidae family is a complex and rich group of insects with a great diversity of antimicrobial peptides with potential antimicrobial activity.

Novel antimicrobial cecropins derived from O. curvicornis and D. satanas dung beetles.

Antibiotic resistance is an increasing global problem and therapeutic alternatives to traditional antibiotics are needed. Antimicrobial and host defense peptides represent an attractive source for new therapeutic strategies, given their wide range of activities including antimicrobial, antitumoral and immunomodulatory. Insects produce several families of these peptides, including cecropins. Herein, we characterized the sequence, structure, and biological activity of three cecropins called satanin 1, 2, and curvicin, found in the transcriptome of two dung beetle species Dichotomius satanas and Onthophagus curvicornis. Sequence and circular dichroism analyses show that they have typical features of the cecropin family: short length (38-39 amino acids), positive charge, and amphipathic α-helical structure. They are active mainly against Gram-negative bacteria (3.12-12.5 µg/mL), with low toxicity on eukaryotic cells resulting in high therapeutic indexes (TI > 30). Peptides also showed effects on TNFα production in LPS-stimulated PBMCs. The biological activity of Satanin 1, 2 and Curvicin makes them interesting leads for antimicrobial strategies.

Standardization of a latex agglutination test for coproantigen detection of Fasciola sp. in bovine cattle stool.

Fasciolosis is a zoonotic parasitic disease, which affects humans and animals; diagnosed through noncommercial immunoassay tests that cannot be used on the field. Thereby, establishing the optimal conditions to develop a latex agglutination technique with IgG and IgM antibodies directed against excretion/secretion antigens of Fasciola sp. is a priority. Latex particles were sensitized with IgG and IgM antibodies directed against excretion/secretion antigens of Fasciola sp. The specificity of the antibodies was determined against antigens of different helminths and protozoa; the sensitivity and specificity of the test was evaluated against a previously standardized direct ELISA. The coupling rates of the IgG and IgM antibodies were 85.77 and 100%, respectively. The minimum detectable concentration of Fasciola sp. excretion/secretion antigens, diluted in a phosphate-buffered saline, was 1.589 mg/mL(IgG) and 0.158 mg/mL(IgM) and for the antigens incorporated in the bovine cattle stool it was 3.178 mg/mL(IgG) and 1.589 mg/mL(IgM). The test showed crossed reaction against Giardia sp., and Cryptosporidium sp. antigens. Agreement of the IgG and IgM latex test against the ELISA test was of 78.78 and 96.96%, respectively; the specificity found was of 100% for both tests and sensitivity was 78.79% (IgG) and 96.97% (IgM). This work standardized the latex agglutination technique to detect Fasciola sp. antigens in bovine cattle stool.

K48-linked polyubiquitination of dengue virus NS1 protein inhibits its interaction with the viral partner NS4B.

Dengue virus (DENV) is a member of the Flaviviridae family, which is transmitted to mammalian species through arthropods, and causes dengue fever or severe dengue fever in humans. The DENV genome encodes for multiple nonstructural (NS) proteins including NS1. NS1 plays an essential role in replication by interacting with other viral proteins including NS4B, however how these interactions are regulated during virus infection is not known. By using bioinformatics, mass spectrometry analysis, and co-immunoprecipitation assays, here we show that DENV-NS1 is ubiquitinated on multiples lysine residues during DENV infection, including K189, a lysine residue previously shown to be important for efficient DENV replication. Data from in vitro and cell culture experiments indicate that dengue NS1 undergoes modification with K48-linked polyubiquitin chains, which usually target proteins to the proteasome for degradation. Furthermore, ubiquitinated NS1 was detected in lysates as well as in supernatants of human and mosquito infected cells. Ubiquitin deconjugation of NS1 using the deubiquitinase OTU resulted in increased interaction with the viral protein NS4B suggesting that ubiquitinated NS1 has reduced affinity for NS4B. In support of these data, a K189R mutation on NS1, which abrogates ubiquitination on amino acid residue 189 of NS1, also increased NS1-NS4B interactions. Our work describes a new mechanism of regulation of NS1-NS4B interactions and suggests that ubiquitination of NS1 may affect DENV replication.

Identification and characterization of novel cecropins from the Oxysternon conspicillatum neotropic dung beetle.

Dung beetles are exposed to a complex microbiological ecosystem during their life cycle. Characterization of novel host-defense peptides (HDP) is essential to understanding the host innate immune response in insects. It constitutes a promising alternative to look for new therapeutic agents against pathogenic microbes. We identified four new HDP, Oxysterlins 1, 2, 3, and 4 from the transcriptome of the Oxysternon conspicillatum dung beetle. These HDP display a highly conserved signal peptide and a mature peptide, characterized by an overall positive charge (cationic) (pI: 10.23-11.49), a hydrophobic ratio (ΦH: 35-41), and amphipathicity. Oxysterlins 1, 2, and 3 have a linear α-helix structure, whilst Oxysterlin 4 has a mixture of both α-helix and ß-sheet structures without disulfide bonds through bioinformatics prediction and circular dichroism. Oxysterlins are part of the cecropin family group in an exclusive clade related to beetle cecropins. They have predominant antimicrobial activity against Gram-negative bacteria, including multidrug resistant strains (3.12-50 µg/mL) measured by plate microdilution. Their kinetics, in a time-killing curve showed concentration-dependent bactericidal activity. Furthermore, these HDP have low toxicity against human erythrocytes (62.5-500 µg/mL) and Vero cells (250-500 µg/mL). This article describes new HDP of the cecropin family from the Oxysternon conspicillatum dung beetle, with antimicrobial activity against multidrug resistant bacteria and low toxicity.

Manifestaciones clínicas y hallazgos de laboratorio de una serie de casos febriles agudos con diagnóstico presuntivo de infección por el virus dengue. Quindío (Colombia) / Clinical manifestations and laboratory findings on a case series of acute febrile syndrome with a presumptive diagnosis of dengue virus infection. Quindio, Colombia

Objetivo: Describir las manifestaciones clínicas y hallazgos de laboratorio de una serie de casos febriles agudos con diagnóstico presuntivo de infección por el virus dengue. en Quindío (Colombia). Materiales y métodos: Se realizó un estudio de corte transversal, en pacientes con sospecha clínica de dengue en el periodo comprendido entre enero y agosto de 2013, en algunos centros hospitalarios del departamento del Quindío. Se tomaron muestras de sangre para diagnóstico de dengue, leptospira, malaria, hepatitis B, y rickettsiosis. Como pruebas confirmatorias para dengue se realizó aislamiento viral en células C6/36HT y serotipificación para dengue por RTPCR; pruebas de función hepática, cuadro hemático y niveles de citocinas. Resultados: Se caracterizaron 149 casos, de los cuales el 43% presentaron infección por dengue, 4% leptospira, 6,8% rickettsias, un caso de malaria y uno de hepatitis B. En 5 casos se logró el aislamiento del DENV2 y DENV3. Mediante la RT-PCR, se evidenció cocirculación de serotipos 2, 3, 4. Se encontró que las enzimas AST/ALT, el conteo de plaquetas, la erupción y el dolor abdominal fueron marcadores característicos de la infección por dengue, mientras la ictericia y el dolor lumbar se correlacionaron con la leptospirosis. Los valores de citocinas mostraron que la IL-10, TNF α variaron significativamente en casos con dengue frente a otros diagnósticos, y la IL-17 a presentó diferencias significativas en individuos con dengue grave. Conclusiones: El dengue se confirmó como causa etiológica importante de síndrome febril icterohemorrágico en el departamento del Quindío, pero la leptospirosis y la rickettsiosis tienen también una participación importante. Sin embargo, en el 44% de los casos fueron catalogados como síndrome febril indeterminado.

Objective: To characterise the clinical and laboratory findings on a series of febrile cases with a presumptive diagnosis of dengue virus infection in Quindío, Colombia. Materials and methods: This study was conducted from January to July 2013. Blood samples were obtained from patients suspected of dengue virus infection from Quindío department hospitals. These samples were tested for dengue, leptospira, malaria, hepatitis B and rickettsiosis. To confirm dengue infection, we performed viral isolation in C6/36HT cells and dengue serotyping by RT-PCR; liver function tests, complete blood counts and cytokine levels. Results: Of 149 cases, 43% were infected by dengue, 4% leptospira, 6.8% rickettsia, one case of malaria and one case of hepatitis b. We obtained 5 clinical isolates of DENV2 and DENV3 that evidenced co-circulation of serotypes 2, 3, and 4. We found that AST/ALT levels, platelet count, rash and abdominal pain were good markers of infection by dengue, while jaundice and lumbar pain suggested leptospirosis. Cytokine levels revealed that IL-10, TNF a varied significantly in dengue compared with other diagnostics and that IL-17 α showed significant differences in individuals with severe dengue. Conclusions: Dengue was confirmed as an important aetiology of acute febrile icterohaemorrhagic syndrome in Quindío, but leptospirosis and rickettsia also play an important role. However, 44% of the cases were classified as undetermined febrile syndrome.

Prevalencia de Fasciola hepatica en humanos y bovinos en el departamento del Quindío-Colombia 2012-2013 / Prevalence of Fasciola hepatica in humans and cattle in the departmentof Quindio-Colombia 2012-2013

Introducción: La fasciolosis es una parasitosis causada por Fasciola hepatica (F. hepatica). En el departamento del Quindío se desconoce su prevalencia tanto en humanos como en bovinos. Objetivo: Determinar la prevalencia de F. hepatica en heces de trabajadores del sector ganadero y bovinos en el departamento del Quindío entre los meses de septiembre de 2012 y marzo de 2013. Materiales y métodos: Se realizó un estudio descriptivo de corte transversal, mediante análisis parasitológico en heces de empleados del sector ganadero y en bovinos en los 12 municipios del departamento del Quindío, usando la técnica directa de Lugol, concentración de Kato-Katz y Ritchie; se realizó la determinación de antígenos de F. hepatica en heces mediante la prueba inmunológica Fascidig®. Se realizó una encuesta epidemiológica a los empleados y propietarios, en la que se consignaron la presencia de sintomatología y los factores de riesgo implicados en la adquisición de esta parasitosis. Resultados: La prevalencia de F. hepatica en bovinos fue 3,74%, por microscopia óptica y 3,01% mediante Fascidig®, y 0% en humanos. Los animales recibieron antiparasitarios en los meses previos a la toma de las muestras, sin embargo, se determinó presencia de huevos de Fasciola en las heces de los bovinos. Los municipios donde se encontraron resultados positivos fueron: Salento, Génova, Quimbaya, Montenegro y Circasia. Conclusión: Demostramos la presencia del parásito F. hepatica en los bovinos en pie de 4 municipios del departamento del Quindío. © 2014 ACIN. Publicado por Elsevier España, S.L.U. Todos los derechos reservados.

Introduction: Fascioliasis is a parasitic disease caused by Fasciola hepatica (F. hepatica) . Theprevalence of this infection in the region of Quindío in humans and in cattle is unknown. Objectives: To determine the prevalence of F. hepatica in feces of cattle workers and cattle inthe region of Quindío from September 2012 to March 2013. Materials and methods: A descriptive, cross-sectional study was performed by parasitologicalanalysis of feces of cattle workers and cattle in 12 municipalities of department of Quindíousing the Lugol direct technique, Kato-Katz and Ritchie concentrations. The determination of Fasciola hepatic antigens in feces was performed by the Fascidig® immunological technique.In addition, an epidemiological survey concerning the symptomatology of the disease and therisk factors involved in the acquisition of this parasite was carried out. Results: The F. hepatica prevalence in cattle was 3,74%, by optical microscopy and 3,01% withFascidig® and 0% in humans. The animals received antiparasitics in the months prior to thetaking of samples; however the presence of F. hepatica eggs in cattle feces was determined.The cities where positive results were found include: Salento, Génova, Quimbaya, Montenegroy Circasia. Conclusion: We have demonstrated the presence of the parasite F. hepatica in cattle in 4 citiesin the region of Quindío.

Expression and purification of an active cecropin-like recombinant protein against multidrug resistance Escherichia coli.

Lucilin is a 36 residue cecropin antimicrobial peptide identified as a partial genetic sequence in Lucilia sericata maggots. The antimicrobial spectrum and toxicity profile of Lucilin is unknown. We first report the expression of Lucilin as an active recombinant fusion protein with a cysteine protease domain (CPD) tag. The fusion protein, GWLK-Lucilin-CPD-His8, showed maximum overexpression in Escherichia coli BL21 cells after 12h induction with 0.5mM IPTG (isopropyl beta-d-thiogalactoside) and growth conditions were 37 °C and 150 rpm shaking. The fusion protein was expressed as a soluble form and was purified by Ni-IMAC. The purified protein was active against E. coli ATCC 35218 with a MIC of 0.68 µM, and a clinical isolate of E. coli with extended spectrum beta-lactamase (ESBL) with a MIC of 0.8 µM. The recombinant GWLK-Lucilin-CPD-His8 was not toxic against human erythrocytes or Vero cells with a therapeutic index >63. The results suggest that GWLK-Lucilin-CPD-His8 represents a potential candidate for therapy against multidrug resistant Gram-negative bacteria.

Los cambios histopatológicos del hígado durante dengue severo: [Editorial] / Histopathological changes in the liver during severe dengue: [Editorial]

El dengue es una enfermedad producida por el virus dengue perteneciente a la familia Flaviviridae , género Flavivirus y que es transmitido a los humanos por el vector Aedes , principalmente Aedes aegypti y Aedes albopictus . A la fecha se reconocen cuatro serotipos del virus, aunque recientemente el Doctor Nikos Vasilakis, virólogo de la Universidad de Texas durante la Tercera Conferencia internacional de Dengue y Dengue Hemorrágico, reportó el que podría ser el quinto serotipo (http://www.dengue2013bangkok.com/home/index/en). Esta sería la primera descripción de un nuevo serotipo para este virus en los últimos 50 años, lo que viene a opacar el panorama del desarrollo de una posible vacuna para esta infección, cada vez más prevalente en el mundo, particularmente en las regiones tropicales y subtropicales del planeta.

Dengue is a disease caused by the dengue virus belonging to the Flaviviridae family, genus Flavivirus, which is transmitted to humans by the Aedes vector, mainly Aedes aegypti and Aedes albopictus. To date, four serotypes of the virus are recognised, although recently Dr. Nikos Vasilakis, a virologist at the University of Texas during the Third International Conference on Dengue and Dengue Haemorrhagic Fever, reported what could be the fifth serotype (http://www.dengue2013bangkok.com/home/index/en). This would be the first description of a new serotype for this virus in the last 50 years, which would overshadow the outlook for the development of a possible vaccine for this increasingly prevalent infection worldwide, particularly in tropical and subtropical regions of the world.

Actividad biológica de los aceites esenciales de Acmella ciliata (Kunth) Cass / Biological activity of essential oils from Acmella ciliata (Kunth) Cass

Introducción: Acmella ciliata (Kunth) Cass. es una arvense nativa del norte de Suramérica conocida por su contenido de alcamidas alifáticas, se usa popularmente como anestésico y analgésico contra los dolores de muelas y de garganta. Objetivos: obtener, analizar y evaluar la actividad biológica de los aceites esenciales de las flores y hojas de Acmella ciliata (Kunth) Cass. Métodos: se obtuvieron los aceites esenciales de Acmella ciliata por hidrodestilación e hidrodestilación asistida por microondas, y se analizaron por cromatografía de gases acoplados a un espectrómetro de masas. La actividad biológica de los aceites esenciales se determinó mediante el método modificado de pozos de agar, se evaluaron sus actividades antimicrobianas frente a 5 bacterias y 1 hongo, junto con pruebas de toxicidad en Artemia salina. Resultados: la hidrodestilación asistida por microondas fue la técnica con mejores rendimientos en la extracción de los aceites esenciales de Acmella ciliata. Sus fracciones volátiles contienen una alta proporción de sesquiterpenos como el trans-β-cariofileno, su componente mayoritario. Los aceites esenciales a 2 concentraciones diferentes (25 y 15 mg/mL) presentaron una marcada actividad antimicrobiana frente a las bacterias grampositivas Staphylococcus aureus y Staphylococcus epidermidis; además exhibieron una baja toxicidad contra Artemia salina, con dosificaciones letales medianas de 176,156 ppm y 100,104 ppm para el aceite esencial de las hojas y flores, respectivamente. Conclusiones: los aceites esenciales de Acmella ciliata son productos que presentan un alto contenido de terpenoides, con marcada acción antimicrobiana frente bacterias grampositivas (Staphylococcus aureus y Staphylococcus epidermidis) y baja toxicidad en Artemia salina.

Introduction: Acmella ciliata (Kunth) Cass. is a native weed of northern South America known by its aliphatic alkamide content and used as an anesthetic and analgesic for toothache and sore throat. Objective: to obtain, to analyze and to evaluate the biological activities of essential oils from Acmella ciliata (Kunth) Cass flowers and leaves. Methods: Acmella ciliata essential oils were obtained by hydrodistillation and microwave-assisted hydrodistillation and analyzed by gas chromatography coupled to mass spectrometry. The biological activity of both essential oils was determined by using the modified agar-well diffusion assay, evaluating their activities against five bacteria and one fungus, along with tests of toxicity in Artemia salina (Lethal Dose 50). Results: microwave-assisted hydrodistillation was the technique with the best performances in the extraction of Acmella ciliata. essential oils. Their volatile fractions contain a high proportion of sesquiterpenes such as β-trans-caryophyllene, the major component. Essential oils at two different concentrations (25 mg/mL and 15 mg/mL) showed a strong antimicrobial activity against gram-positive bacteria Staphylococcus aureus and Staphylococcus epidermidis, in addition they exhibited low toxicity against Artemia salina, presenting mean lethal doses of 176, 156 and 100,104 ppm for the essential oils from leaves and flowers, respectively. Conclusions: Acmella ciliata essential oils are products with high content of terpenoids and marked antimicrobial activity against gram-positive bacteria (Staphylococcus aureus and Staphylococcus epidermidis) and low toxicity against Artemia salina.

Efecto antiparasitario de los extractos etanólicos y etéreos de Ficus obtusifolia Kunth ( Moraceae), frente a parásitos de clase nematodos ( Toxocara catis y Toxocara canis) / Antiparasitic effect of ethanolic and ethereal extracts of Ficus obtusifolia Kunth ( Moraceae), against nematode class parasites (Toxocara cati and Toxocara canis)

A los extractos etanólico y etéreo de hojas y frutos de Ficus obtusifolia Kunth (Moraceae), se les evaluó la actividad antiparasitaria contra Toxocara canis y Toxocara catis, y la antimicrobiana, contra Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli y Proteus vulgaris. Asimismo, se les realizó tamización fitoquímica para determinar algunos metabolitos secundarios y se midió su toxicidad con Artemia salina. El extracto etanólico del fruto mostró mayor mortalidad para parásitos adultos in vivo y presentó mayor inhibición embrionaria en huevos de T. canis. Ningún extracto exhibió halo de inhibición en el agar Mueller-Hinton, lo cual indica que no hay actividad antimicrobiana. Se observó mayor toxicidad frente a la A. salina a las 24 horas, para el extracto etanólico de hojas y frutos.

The antiaparatsitic activity of ether and ethanol extract in Ficus obtusifolia Kunth (Moraceae) leaves and fruits was assessed against Toxocara canis and Toxocara catis and the antimicrobial activity against Staphylococcus aureus, Streptococcus pyogenes, E-coli and Proteus vulgaris. Likewise, phytochemical screening was conducted to determine some secondary metabolites, and their toxicity was measured with Arthemia saline. Ethanol fruit extract showed a better mortality rate for adult parasites in vivo and showed higher embryonic inhibition in eggs of T. canis. No extract showed an inhibition halo in the Mueller-Hinton agar, which indicates that there is no antimicrobial activity. Increased toxicity was observed in contact with Arthemia saline at 24 hours for the ethanol extract of leaves and fruit.

Factores de virulencia del patógeno intestinal Entamoeba histolytica / Virulence factors of intestinal pathogen Entamoeba histolytica

Entamoeba histolytica es un protozoo entérico causante de la amebiasis intestinal y extraintestinal. Se calcula que 10% de la población mundial está infectada por el complejo Entamoeba histolytica/Entamoeba dispar. Según la OMS, hay 500 millones de nuevas infecciones por año y, aproximadamente, 70.000 a 100.000 muertes a causas de ellas. Este parásito cumple un proceso de invasión muy elaborado, en el cual se secretan y expresan proteínas que le permiten adherirse al epitelio, degradar la matriz extracelular y producir citólisis de las células epiteliales para penetrar dentro de la mucosa. El entendimiento de estos factores de virulencia ha generado múltiples estudios en diferentes áreas de las ciencias biomédicas, desde métodos diagnósticos cada vez más sensibles y específicos hasta candidatos para vacunas, lo que abre nuevas expectativas terapéuticas a raíz de estos estudios.

The enteric protozoan parasite Entamoeba histolytica is a human pathogen that causes widespread morbidity and mortality. It is estimated that 10% of the world’s population is infected with the complex Entamoeba histolytica/ Entamoeba dispar. According to the WHO there are 500 million new infections per year and it is the cause of approximately 70,000 - 100,000 deaths. This parasite has a very elaborate process of invasion, where there are expressed and secreted proteins that allow the parasite to adhere to the epithelium, to degrade extracellular matrix and to penetrate epithelial cells within the mucosa. Numerous studies have been carried out to understand how virulence factors work in diverse areas of biomedical sciences. The studies have proposed diagnostic tests to increase the sensitivity and specificity and to find vaccine candidates, which are an opening way to new therapeutic expectations.

[Evaluation of the IgG anti-Toxoplasma response and its avidity by western-blot in HIV-patients]. / Evaluación de la respuesta IgG anti-Toxoplasma y su avidez por western-blot en pacientes infectados por VIH.

The IgG anti-Toxoplasma western blot technique was used in 25 HIV-cases and 8 control sera from patients without HIV infection aimed at evaluating the humoral response in these patients. They were divided into 3 groups: 14 HIV positive cases with cerebral toxoplasmosis and IgG anti-Toxoplasma serological titers, 11 HIV positive cases without cerebral toxoplasmosis and with IgG anti-Toxoplasma titers, and 8 HIV negative patients with IgG anti-Toxoplasma titers. It was found that the higher the IgG anti-Toxoplasma serum titers are, the greater the number of bands in the western-blot is. The intensity of the bands measured by densitometry varied significantly for proteins of 66 and 31 kDa. According to the results, these proteins are of interest to evaluate their role in the reactivation of toxoplasmosis in HIV patients.