2,046 research outputs found

    Incidencia de malaria en una región endémica del estado Amazonas, Venezuela

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    This study was carried out to determine the incidence of malaria in an endemic region of Amazonas State, Venezuela. For this, 200 random samples were collected from symptomatic and asymptomatic individuals from San Fernando de Atabapo and Santa Barbara. Epidemiological factors were related to malaria infection, which was diagnosed by microscopy observation and amplification of the 18S rDNA sequence by PCR. Malaria prevalence in these populations was 28.5%, whilst P. vivax and P. falciparum prevalences were 12 and 17%, respectively. No infection by P. malariae was found. A mixed infection was found on an asymptomatic individual. Prevalence patterns differed between age groups depending on the Plasmodium species. We found that 34.8% of the P. vivax and 15.2% of the P. falciparum infections were asymptomatic. The use of nets was helpful to prevent P. vivax infection, but did not protect against P. falciparum infection. The results suggest the presence of more than one mosquito vector in the area, displaying a differential pattern of infection for each Plasmodium species. There appear to be risk factors associated with malaria infections in some individuals. The population based approach and PCR diagnosis improved the accuracy of the statistical analysis in the study.Este estudio fue llevado a cabo para determinar la incidencia de malaria en una región endémica del estado Amazonas, Venezuela. Doscientas muestras tomadas al azar fueron colectadas de individuos sintomáticos y asintomáticos de San Fernando de Atabapo y Santa Bárbara. Factores epidemiológicos fueron relacionados con la infección de malaria, diagnosticada por observación microscópica y por la amplificación por PCR de la secuencia del ADNr 18S. La prevalencia de malaria en estas poblaciones fue 28.5%, en tanto que las prevalencias para P. vivax y P. falciparum fueron 12 y 17%, respectivamente. No se encontró infección por P. malariae. Se encontró una infección mixta en un individuo asintomático. Los patrones de prevalencia difirieron entre los grupos de edades, dependiendo de la especie de Plasmodium. Se encontró una frecuencia de infecciones asintomáticas de 34.8% y 15.2% para P. vivax y P. falciparum, respectivamente. El uso de mosquiteros fue útil para prevenir infecciones por P. vivax, pero no protegió de infecciones por P. falciparum. Los resultados sugieren la presencia de mas de un mosquito vector en el área, mostrando patrones diferenciales de infección para cada especie de Plasmodium. Pareciera existir factores de riesgo asociados con la infección de malaria en algunos individuos. El estudio a nivel poblacional y el diagnóstico por PCR mejoró la exactitud del análisis estadístico en este estudio

    New Perspectives Related to the Bioluminescent System in Dinoflagellates: Pyrocystis lunula, a Case Study

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    Pyrocystis lunula is considered a model organism due to its bioluminescence capacity linked to circadian rhythms. The mechanisms underlying the bioluminescent phenomenon have been well characterized in dinoflagellates; however, there are still some aspects that remain an enigma. Such is the case of the presence and diversity of the luciferin-binding protein (LBP), as well as the synthesis process of luciferin. Here we carry out a review of the literature in relation to the molecular players responsible for bioluminescence in dinoflagellates, with particular interest in P. lunula. We also carried out a phylogenetic analysis of the conservation of protein sequence, structure and evolutionary pattern of these key players. The basic structure of the luciferase (LCF) is quite conserved among the sequences reported to date for dinoflagellate species, but not in the case of the LBP, which has proven to be more variable in terms of sequence and structure. In the case of luciferin, its synthesis has been shown to be complex process with more than one metabolic pathway involved. The glutathione S-transferase (GST) and the P630 or blue compound, seem to be involved in this process. In the same way, various hypotheses regarding the role of bioluminescence in dinoflagellates are exposed

    DETERMINACION DE LAS CARACTERISTICAS BIOMETRICAS PARA LA EVALUACION DE TRES RAZAS DE ARTEMIA EN VENEZUELA

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    Se llevó a cabo un estudio con tres razas de la Artemia de Venezuela: Araya, Coche y Cumaraguas, para determinar sus características biométricas. Los quistes fueron obtenidos del medio con una malla de plancton y almacenados en salmuera. Estos se incubaron en condiciones estándar. A las 48 horas se obtuvieron los nauplios y se determinaron las características biométricas. Los diámetros de los quistes hidratados oscilaron entre 240 -260 um, y el grosor del carian osciló entre 8 . 5 - 1 0.5 um. Los resultados de porcentaje de eclosión oscilaron entre 56.3 - 81.2%, eficiencia de eclosión entre 113'247- 295'110 n/g Q, producción de eclosión entre 271 - 430 mg n/ g Q, la sincronía de eclosión entre 16 - 17 horas, la longitud y el peso de los nauplios entre 470 - 530 um y 2.1-2.4 ug, respectivamente. Mientras los quistes de Coche no mostraron buenos resultados. Los quistes de A raya y Cumaraguas mostraron tener valores dentro del promedio de las razas comerciales en cuanto a porcentaje, eficiencia y producción de eclosión, por lo que éstos últimos podrían utilizarse a nivel comercial en la acuicultura

    AMINOGLYCOSIDE RESISTANCE GENES IN Pseudomonas aeruginosa ISOLATES FROM CUMANA, VENEZUELA

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    The enzymatic modification of aminoglycosides by aminoglycoside-acetyltransferases (AAC), aminoglycoside-adenyltransferases (AAD), and aminoglycoside-phosphotransferases (APH), is the most common resistance mechanism in P. aeruginosa and these enzymes can be coded on mobile genetic elements that contribute to their dispersion. One hundred and thirty seven P. aeruginosa isolates from the University Hospital, Cumana, Venezuela (HUAPA) were evaluated. Antimicrobial susceptibility was determined by the disk diffusion method and theaac, aadB and aph genes were detected by PCR. Most of the P. aeruginosa isolates (33/137) were identified from the Intensive Care Unit (ICU), mainly from discharges (96/137). The frequency of resistant P. aeruginosaisolates was found to be higher for the aminoglycosides tobramycin and amikacin (30.7 and 29.9%, respectively). Phenotype VI, resistant to these antibiotics, was the most frequent (14/49), followed by phenotype I, resistant to all the aminoglycosides tested (12/49). The aac(6´)-Ib,aphA1 and aadB genes were the most frequently detected, and the simultaneous presence of several resistance genes in the same isolate was demonstrated. Aminoglycoside resistance in isolates ofP. aeruginosa at the HUAPA is partly due to the presence of the aac(6´)-Ib, aphA1 andaadB genes, but the high rates of antimicrobial resistance suggest the existence of several mechanisms acting together. This is the first report of aminoglycoside resistance genes in Venezuela and one of the few in Latin America

    Virulence factors and integrons are associated with MDR and XDR phenotypes in nosocomial strains of Pseudomonas aeruginosa in a Venezuelan university hospital

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    Multidrug resistance (MDR), virulence and transferable elements potentiate Pseudomonas aeruginosa’s role as an opportunistic pathogen creating a high risk for public health. In this study, we evaluated the possible association of multidrug resistance, virulence factors and integrons with intrahospital P. aeruginosa strains isolated from patients at Cumana hospital, Venezuela. Relevant clinical-epidemiological data were collected to study 176 strains (2009-2016) isolated from different hospital units. Bacterial resistance was classified as susceptible, low-level resistant (LDR), multidrug resistant (MDR) and extensively drugresistant (XDR). Most strains produced pyoverdine, DNase, gelatinase and hemolysin. Around 73% of the strains showed some type of movement. MDR and XDR strains increased from 2009 (24.2% and 4.8%, respectively) to 2016 (53.1% and 18.8%); while LDR decreased from 64.5% to 6.3%. The exoU and exoS genes were found in a significant number of strains (38.1 and 7.4%, respectively). Class I integrons were detected in 35.8% of the strains and the frequency was associated with resistance (42.9, 22.4, 41.4 and 61.9%, for susceptible, LDR, MDR and XDR, respectively). The MDR/XDR strains were positively associated with hemolysins and exoU, but negatively associated with bacterial twitching. MDR/XDR phenotypes were also associated with the Intensive Care Unit (ICU), septicemia, bronchial infection and diabetic foot ulcers, as well as long hospital stay (≥10 days) and previous antimicrobial treatment. High frequency of MDR/XDR strains and their association with classI integrons and virulence factors can increase the infection potential, as well as morbidity and mortality of patients attending this hospital and could spread infection to the community, creating a health risk for the region

    Primer reporte de cepas de Enterobacter spp productoras de metalobetalactamasas de Venezuela

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    Clinical strains of Enterobacter were isolated from Cumana's Central Hospital in Venezuela, and classified as E. cloacae (21), E. aerogenes (7), E. intermedium (1), E. sakazakii (1) and three unclassified. The strains showed high levels of resistance, especially to SXT (58.1%), CRO (48.8%), CAZ (46.6%), PIP (46.4%), CIP (45.2%) and ATM (43.3%). This is the first report for South America of blaVIM-2 in two E. cloacae and one Enterobacter sp., which also showed multiple mechanisms of resistance. Both E. cloacae showed blaTEM-1, but only one showed blaCTX-M-15 gene, while no blaSHV was detected.Cepas clínicas de Enterobacter fueron aisladas del Hospital central de Cumaná en Venezuela, y se clasificaron como E. cloacae (21), E. aerogenes (7), E. intermedium (1), E. sakazakii (1) y 3 sin clasificar. Las cepas mostraron altos niveles de resistencia, especialmente a SXT (58.1%), CRO (48.8%), CAZ (46.6%), PIP (46.4%), CIP (45.2%) and ATM (43.3%). Este es el primer reporte de América del Sur de blaVIM-2 en dos cepas de E. cloacae y una de Enterobacter sp., las cuales también mostraron múltiples mecanismos de resistencia. Ambas especies de E. cloacae mostraron genes blaTEM-1, pero solo una mostro el gen blaCTX-M-15, mientras que blaSHV no fue detectado

    Micobiota produtora de fitase isolada de solo e serapilheira do Bioma Cerrado

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    The majority of Brazilian arable soils shows P deficiency, due to the fact that most of this element in the soil is unavailable for the plant absorption, for this and other reasons, the ability of filamentous fungi to solubilize P from various sources, insoluble, organic and inorganic, has been considered a desirable feature for several uses. The aim of this study was to characterize the production of phytase mycobiota in soil located in Cerrado in two seasons, under dry and rainy seasons, and also characterize abiotic factors in this biome in order to verify the existence of correlations between the quantitative and qualitative aspects of their mycobiotas in these conditions. The samples were collected from eight forest fragments twice, two soil depths (0-5 and 5-10 cm) and litter layer to quantify mycobiota and the evaluation of phytase production. In the collection carried out in the rainy season, the total number of phytase producing fungi was lower, but the number of Aspergillus section Nigri producers of phytase was greater. In the dry season the number of phytase producing fungi belonging to the genus Penicillium was higher. The year season´s factor alters quantitatively and qualitatively the phytase producer mycobiota. It was concluded that the soils are potentially exploitable in relation to obtaining phosphorus solubilizing fungi, and the dry season is more propitiate to the achievement of these fungi.Grande parte dos solos agricultáveis brasileiros apresenta deficiência de P, em função da maior parte deste elemento estar indisponível para a absorção pelas plantas. Neste contexto, a habilidade dos fungos filamentosos em solubilizar o P de várias fontes, sejam estas, insolúveis, orgânicas e/ou inorgânicas, tem sido considerada uma característica de destacada importância. O objetivo do presente estudo foi caracterizar a micobiota produtora de fitase no Bioma Cerrado, bem como, apresentar uma caracterização dos fatores abióticos do presente bioma e as possíveis correlações com a micobiota encontrada. As amostras foram coletadas de oito fragmentos florestais, em duas épocas, duas profundidades do solo (0-5 e 5-10 cm) e na camada de serapilheira para a quantificação da micobiota e avaliação da produção de fitase. As coletas foram realizadas em duas épocas, sendo uma na época chuvosa e outra na época seca. Na coleta da época chuvosa, o número total de fungos produtores de fitase foi menor, mas o número de Aspergillus seção Nigri produtores de fitase foi maior. Na época seca, o número de fungos produtores de fitase pertencentes ao gênero Penicillium foi maior. O fator época do ano alterou qualitativamente e quantitativamente a micobiota produtora de fitase. Concluiu-se que os solos do Bioma Cerrado são potencialmente exploráveis para a obtenção de fungos solubilizadores de P, sendo a época seca do ano a mais propícia para este fim

    Identificación de Escherichia coli enteropatógena en niños con síndrome diarreico agudo del Estado Sucre, Venezue

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    Introduction: Diarrheagenic Escherichia coli is an important causative agent of acute diarrheic syndrome. Objective: To identify clonal groups of enteropathogenic E. coli (EPEC), in 485 children with acute diarrhea aged 0 to 10 years attending health care centers in Arismendi, Benítez and Sucre municipalities, Sucre state, Venezuela, from March to December, 2011. Materials and methods: After obtaining the informed consent, stool samples were collected. Escherichia coli was identified using standard coproculture methods and serology with polyvalent and monovalent antisera. DNA was isolated, and eae (intimin) and bfpA (bundlin) genes were amplified through two multiplex polymerase chain reactions (PCR). Results: The presence of bacterial infection was determined in 39.6% of coprocultures. The prevalence of E. coli was 54.7%; 82.9% of these isolates were positive by serology for the evaluated serogroups and serotypes, which were mostly identified in children between 0 and 2 years (37.9%); 48.6% of E. coli strains amplified the eae gene; of these, 58.8% were classified as typical EPEC (eae+ y bfp+). EPEC II was the most common serogroup (38.7%), with predominance of typical EPEC (60%). In positive strains for eae gene, the β intimin allele was the most frequently identified (74.5%). Only four strains with O157:H7 serotype were identified, which showed no PCR amplification of the eae and bfpA genes. Conclusion: This study showed the importance of molecular tests to identify diarrheagenic E. coli strains causing clinical conditions of varying severity.Introducción. Escherichia coli es uno de los principales agentes causales del síndrome diarreico agudo.Objetivo. Identificar grupos clonales de E. coli enteropatógena en 485 casos de diarrea aguda en niños entre 0 y 10 años de edad atendidos en centros de salud de los municipios de Arismendi, Benítez y Sucre del estado Sucre, Venezuela, entre marzo y diciembre de 2011.Materiales y métodos. Previo consentimiento informado, se recolectaron muestras fecales y se identificó E. coli mediante coprocultivo estándar y serología con antisueros polivalentes y monovalentes. Se aisló el ADN y se amplificaron los genes eae (intimina) y bfpA (bundlina) mediante dos pruebas de reacción en cadena de la polimerasa (PCR) múltiples.Resultados. En 39,6 % de los coprocultivos se determinó la presencia de infección bacteriana. La prevalencia de E. coli fue de 54,7 %; 82,9 % de estas cepas fue positivo por serología para los serogrupos y el serotipo evaluados, principalmente en niños entre los 0 y los 2 años (37,9 %). El 48,6 % de las cepas de E. coli amplificaron para el gen eae y, de estas, 58,8 % se clasificó como cepas de E. coli enteropatógena típica (eae+ y bfp+). El ECEP II fue el serogrupo más frecuente (38,7 %), con predominio de bacterias E. coli enteropatógenas típicas (60 %). El alelo β de la intimina fue el más identificado (74,5 %) en las cepas positivas para el gen eae. Solo se identificaron cuatro cepas con el serotipo O157:H7 utilizando antisueros, las cuales no amplificaron mediante PCR para los genes eae y bfpA.Conclusiones. Este estudio demostró la importancia de aplicar pruebas moleculares en la identificación de las cepas de E. coli causantes de diarrea de diversa gravedad

    Processo para extração e esterificação catalítica dos ácidos graxos presentes na escuma de esgoto

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    Em 8/05/2015: Anuidade de patente de invenção do 11º ao 15º ano no prazo ordinárioConcedidaA inovação ora proposta descreve um processo de esterificação de ácidos graxos presentes na chamada "escuma de esgoto", ou seja, fase sobrenadante do esgoto rica em matéria graxa, sendo que esses ácidos graxos são extraídos da escuma e esterificados por catálise ácida e reagentes como álcool metílico ou etílico

    Princípios de Construção Enxuta em Empresa de Pequeno Porte em Guarulhos (SP)

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    O objetivo desta pesquisa é verificar de que maneira os princípios da Construção Enxuta estão sendo empregados em empresa de pequeno porte do segmento de Construção Civil. A pesquisa é de natureza qualitativa e exploratória, sendo o estudo de caso realizado em uma construtora de pequeno porte de edifícios verticais com o apoio do Sindicato das Empresas de Compra, Venda, Locação e Administração de Imóveis Residenciais e Comerciais de São Paulo - SECOVI. Observou-se grande interesse na implantação, sendo um ponto negativo a necessidade de mudança de cultura, visto que muitas atividades tidas como ”vícios” devem ser eliminadas, frente a novo conhecimento. Motivada pelos gestores e alta direção, a filosofia será bem vinda, assim como outras ferramentas de Produção Enxuta, tais como o kanban, housekeeping, 5S, Just in Time e melhorias nos canteiros de obra e processos logísticos. Concluiu-se nesta pesquisa que os princípios da Construção Enxuta são pouco conhecidos pelos profissionais, na prática sendo voltados para gestão da qualidade e produtividade. Constatou-se que, ao mencionar os princípios, estes são de pouco conhecimento, e tem-se uma aceitação imediata quando se fala em redução de tempo e aumento da produtividade com eliminação de tarefas consideradas como de não agregação de valor
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