Sensibilidad antimicrobiana de la microbiota ambiental de las unidades de cuidados intensivos de un hospital peruano

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José Díaz-Tello

Full Text Available Con el objetivo de detectar y determinar la sensibilidad antimicrobiana de bacilos Gram negativos y cocos Gram positivos aislados de la microbiota ambiental de los servicios de la Unidad de Cuidados Intensivos (UCI de Neonatología, de Pediatría y de la Unidad de trasplantes (renal, hepático y general en un hospital de Lima; se tomaron 80 muestras de superficies inanimadas usando hisopado húmedo. Se identificaron 61 cepas bacterianas que correspondieron a Staphylococcus epidermidis (46,0%, Alcaligenes sp. (21,3%, Pseudomonas aeruginosa (16,4%, Acinetobacter sp. (13,1% Staphylococcus aureus (1,6% y Staphylococcus haemolyticcus (1,6%. Acinetobacter y Pseudomonas aeruginosa mostraron una elevada sensibilidad a los antibióticos evaluados, en contraste Alcaligenes sp. y Staphylococcus epidermidis presentaron la mayor resistencia antimicrobiana. Staphylococcus epidermidis y Alcaligenes sp. fueron las bacterias que presentaron mayor resistencia a los antibióticos y las que mayormente se aislaron. Se recomienda recurrir a métodos de asepsia y monitoreo sostenidos en las UCI.

Incremento de los urocultivos positivos en un hospital de cuarto nivel de atención Increment in positive urine cultures in a fourth level attention hospital

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JAIME ALBERTO LÓPEZ

2006-03-01

Full Text Available Objetivo. Determinar si la implementación de intervenciones educativas y administrativas con respecto al empleo de pruebas de tamizaje incrementa la proporción de urocultivos positivos, en comparación con no emplear dichas intervenciones. Diseño. Este es un estudio prospectivo, analítico. Lugar.Hospital Pablo Tobón Uribe, Medellín, Colombia. Población. Se realizaron 25.766 urocultivos entre 1998 y 2005. Métodos. Algunas acciones educativas y administrativas se realizaron para incrementar la positividad de los urocultivos solicitados. Se registraron las coloraciones de Gram ordenadas para las muestras de los pacientes hospitalizados y atendidos en urgencias que fueron hospitalizados, los urocultivos positivos de los recomendados, los solicitados directamente por el médico tratante y por el servicio solicitante. Resultados. El porcentaje de coloraciones de Gram de orina sin centrifugar realizadas por urocultivo, en los pacientes hospitalizados, se incrementó de 0,7% en 1998 a 32,1% en 2005 ( p = 0,000. Los urocultivos fueron positivos en el 79,4% de los casos cuando se realizaron por recomendación del laboratorio, mientras que la positividad de los solicitados directamente fue del 27,9% ( p = 0,000. El porcentaje total de urocultivos positivos en 1998 en los pacientes que fueron hospitalizados, fue de 29,7%, mientras que de 1999 a 2005 fue del 40,3%, años en los cuales el laboratorio de microbiología intervino activamente ( c² = 74,95; p = 0,000. Los urocultivos positivos solicitados desde urgencias de adultos y pediatría aumentaron de 34% y 15% en 1998, a 66% y 30% en el 2005, respectivamente; mientras que en otros servicios de hospitalización el porcentaje pasó de 26% a 40%. Conclusiones. El porcentaje de los urocultivos positivos se puede incrementar si el conocimiento derivado del estudio de las pruebas de tamizaje es aplicado a la práctica clínica.Goal: To determine if the implementation of educative and administrative

Microbiological contamination of a hemodialysis center water distribution system Contaminação microbiológica no sistema de distribuição de água de um centro de hemodiálise

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Lilian Bueno Montanari

2009-02-01

-se a técnica da membrana filtrante com poros de 0,22 µm para bactérias e de 0,45 µm para micobactérias. A identificação foi realizada através de métodos microbiológicos convencionais e de biologia molecular. Isolados bacterianos foram obtidos de sistema de distribuição (128, águas das máquinas (43 e sistema de reuso (3. Entre os isolados 32 foram de bacilos Gram-positivos, 120 bacilos Gram-negativos, 20 Cocos Gram-positivos e 11 micobactérias. Neste estudo, sugerimos que suprimentos de água para o Centro de Hemodiálise devam ser monitorados, adotando-se medidas profiláticas eficazes que minimizem a exposição destes pacientes imunodeficientes a fontes aquáticas ambientais contaminadas.

Actividad “in vitro” de 10 antimicrobianos frente a bacterias anaerobias: Estudio multicéntrico, 1999-2002 “In vitro” activity of ten antimicrobial agents against anaerobic bacteria. A collaborative study, 1999-2002

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M. Litterio

2004-09-01

Full Text Available Se evaluó la actividad de ampicilina, ampicilina-sulbactama, cefoxitina, ceftriaxona, imipenem, piperacilina, piperacilina-tazobactama, clindamicina, metronidazol y azitromicina frente a 166 cepas de bacterias anaerobias aisladas en 8 hospitales de Buenos Aires. Se estudiaron: Bacteroides grupo fragilis (65, Fusobacterium spp. (26, Prevotella spp. (21, Porphyromonas spp. (10, Clostridium difficile (10, otros clostridios (12 y cocos gram-positivos (22. Las CIMs se determinaron usando el método patrón de dilución en agar recomendado por el NCCLS, documento M11-A5. Los antibióticos más activos fueron metronidazol y piperacilina-tazobactama que exhibieron valores de CIM90£ 2 µg/ml y £ 4 µg/ml frente a los microorganismos gram-negativos y £ 2 µg/ml y £ 8 µg/ml frente a los microorganismos gram-positivos, respectivamente. Entre los b-lactámicos el orden de actividad frente a bacilos gram-negativos fue: imipenem > piperacilina > cefoxitina > ceftriaxona > ampicilina. En gram-positivos la actividad decreciente fue: piperacilina> imipenem > cefoxitina > ceftriaxona > ampicilina. La mayoría de las especies estudiadas mostraron distintos niveles de resistencia con clindamicina y azitromicina. Sin embargo, el 90% de las cepas de Fusobacterium nucleatum y Por-phyromonas spp. fue inhibido por una concentración de 0,125 µg/ml de clindamicina y azitromicina, respectivamente.The antimicrobial activity of ampicillin, ampicillin-sulbactam, cefoxitin, ceftriaxone, imipenem, piperacillin, piperacillin-tazobactam, clindamycin, metronidazole, and azitromycin was assesed against 166 strains of anaerobic bacteria recovered from eight hospitals in Buenos Aires. The strains studied were Bacteroidesfragilis group (65, Fusobacterium spp. (26, Prevotella spp. (21, Porphyromonas spp. (10, Clostridium difficile (10, other clostridia (12, and gram-positive cocci (22. The MICs were determined by the agar dilution method according to NCCLS document M11-A5

Usefulness of urinal urinalysis and urine gram stain in the diagnosis of rinary tract infection in hospitalized patients Utilidad del citoquímico y la coloración de Gram en muestras de orina en el diagnóstico de las infecciones del tracto urinario en pacientes hospitalizados.

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Sergio Jaramillo Velásquez

2005-04-01

Gram de orina sin centrifugar, y en 8.008 orinas se hizo la coloración de Gram del sedimento urinario. En comparación con el urocultivo, el citoquímico de orina presentó sensibilidad del 99%, especificidad del 51%, valor predictivo positivo del 60%, y valor predictivo negativo del 98%. La coloración de Gram de la orina sin centrifugar tuvo sensibilidad, especificidad y valores predictivos positivo y negativo de 98%, 73%, 82% y 97%, respectivamente. Para la coloración de Gram del sedimento urinario los valores correspondientes a la sensibilidad, especificidad y valores predictivos positivo y negativo fueron 95%, 78%, 67%, y 97%. Conclusiones: el citoquímico de orina, bajo los criterios propuestos, y la coloración de Gram tienen un alto valor predictivo negativo, que permitiría utilizarlos como pruebas de tamización para determinar la necesidad de solicitar el urocultivo.

Granulomas do pênis: uma complicação rara da terapia intravesical com Bacilo Calmette-Guérin Granulomas of the penis: a rare complication of intravesical therapy with Bacillus Calmette-Guerin

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Sara Isabel Alcântara Lestre

2011-08-01

Full Text Available A imunoterapia com o Bacilo Calmette-Guérin é amplamente usada no tratamento e profilaxia da neoplasia urotelial superficial. As complicações associadas ao tratamento são comuns. Os autores relatam um caso de inflamação granulomatosa do pênis, associada à terapia intravesical com Bacilo Calmette-Guérin, com múltiplos nódulos eritematosos indolores localizados na glande. É também efetuada uma revisão da literatura. A balanopostite granulomatosa é uma complicação rara associada à imunoterapia com Bacilo Calmette-Guérin, com uma apresentação clinicamente heterogênea que pode dificultar o diagnóstico. O seu reconhecimento clínico é essencial para o início precoce de tuberculostáticos e interrupção de Bacilo Calmette-GuérinImmunotherapy with Bacillus Calmette-Guérin is widely used for treatment and prophylaxis of superficial urothelial cancer. Complications associated with Bacillus Calmette-Guérin treatment are common. The authors describe a case of granulomatous inflammation of the penis associated with intravesical Bacillus Calmette-Guérin therapy, presenting with multiple erythematous and painless nodules located on the glans. A review of the literature is also performed. Granulomatous balanoposthitis is a rare complication of Bacillus Calmette-Guérin immunotherapy, with heterogeneous clinical presentation, which can make the diagnosis difficult. Its clinical recognition is essential for early start of therapy with antitubercular agents and interruption of Bacillus Calmette-Guérin

Características clínicas y microbiológicas de los pacientes neutropénicos febriles con neoplasias hematológicas

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Fabián Alberto Jaimes Barragán

2008-02-01

Full Text Available Se estudiaron en forma retrospectiva 441 historias clínicas en el período comprendido entre enero de 2003 y diciembre de 2005. De éstas, se identificaron las características de 117 episodios de neutropenia febril en 96 pacientes. La mediana de edad fue 34 años y el 56,4% de los episodios ocurrieron en hombres. Las más frecuentes neoplasias hematológicas relacionadas con neutropenia febril fueron leucemia linfoide aguda (LLA y leucemia mieloide aguda (LMA con 45 episodios de cada una, que corresponden al 76,9%. La mediana de duración de la neutropenia fue 8 días y el 60,7% de los casos entraron en la categoría de neutropenia grave. La mortalidad global fue del 32% y el 81,5% de estas muertes estuvieron asociadas directamente con la infección. Se obtuvo aislamiento microbiológico en el 51% de los eventos. Los bacilos gram negativos (BGN constituyeron el 59% de los aislamientos microbiológicos y los cocos gram positivos el 32%. El 14,3% de los BGN aislados fueron positivos para beta lactamasas de espectro extendido (BLEE y la resistencia global a ciprofloxacina alcanzó el 31,4%. El esquema antimicrobiano empírico más frecuentemente utilizado fue ciprofloxacina más ceftriaxona; la respuesta terapéutica fue desfavorable en 65% de los casos. En el Hospital San Vicente de Paúl de Medellín siguen primando los gérmenes gram negativos y son altas las tasas de resistencia a los antibióticos utilizados tradicionalmente como de primera línea, lo que sugiere la necesidad de reevaluar la pertinencia de estos esquemas.

Endocarditis fatal con localización mitral producida por Erysipelothrix rhusiopathiae Fatal mitral valve endocarditis by Erysipelothrix rhusiopathiae

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G.V. Vallespi

2005-06-01

Full Text Available Se describe un caso fatal de endocarditis en válvula mitral por Erysipelothrix rhusiopathiae, en un paciente varón de 45 años con antecedentes de etilismo crónico y sin contacto previo con animales. Presentaba un síndrome febril prolongado con poliartralgias, pérdida de peso y dolor en región lumbar y miembros inferiores. Los hemocultivos (2/2 fueron positivos a las 48 hs. de incubación y en el examen directo se observaron bacilos gram-positivos pleomórficos. En el subcultivo en agar sangre ovina al 5% desarrollaron colonias puntiformes con alfa hemólisis, catalasa y oxidasa negativas, PYR y LAP positivas y con producción de H2S en medio TSI. La cepa aislada fue identificada como E. rhusiopathiae de acuerdo a la metodología convencional y confirmada con API Coryne. El cuadro se asumió como una probable endocarditis demostrada mediante un ecocardiograma transtorácico. Se comenzó el tratamiento endovenoso con ampicilina y gentamicina. El paciente evolucionó favorablemente y se tornó afebril, sin embargo falleció a los 19 días de internación por edema agudo de pulmón. La prueba de sensibilidad por E-test demostró resistencia a vancomicina y gentamicina y sensibilidad a penicilina y cefotaxima. Es importante valorar los aislamientos de bacilos gram-positivos pleomórficos, catalasa y oxidasa negativos y realizar la prueba de producción de SH2 en el medio TSI. La resistencia a vancomicina ayuda a la identificación y permite establecer una correcta terapia antimicrobiana. Si bien se considera que las infecciones por E. rhusiopathiae son de carácter ocupacional, el contacto con cerdos u otros animales puede no ser evidente.A fatal case of Erysipelothrix rhusiopathiae mitral valve endocarditis is described in a 45 years old male, with a history of chronic alcohol abuse and without animals contact. He presented intermittent fever, polyarthralgia, weight loss, and low back pain. In blood cultures (2 bottles, gram

Reflexiones sobre el apoyo conductual positivo

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Sebastià FORTEZA BAUZÁ

2015-12-01

Full Text Available El Apoyo Conductual Positivo (ACP representa un movimiento científico que une dos líneas de trabajo, una bajo el Análisis Conductual Aplicado y otra de carácter teórico que recoge valores y conceptos descritos y desarrollados en el campo de las discapacidades intelectuales. En sus inicios fue una intervención ante las conductas problemáticas con procedimientos positivos en contraposición al abuso de prácticas negativas (aversivas. Paso a paso, se comprobó que las técnicas positivas necesitaban ser aplicadas de forma preventiva y proactiva para educar y reforzar habilidades cuya equivalencia funcional fuera la misma que motivaba las conductas problemáticas. Por último, se introdujeron claves de la línea teórica y del contexto, como calidad, normalización, valores, etcétera. Hoy el ACP ha trascendido su primer cometido y es una forma de trabajar en cualquier servicio independientemente de que haya o no conductas problemáticas, más aún, está siendo aplicado en contextos escolares,judiciales y de tercera edad. Ahora bien, el ACP tiene bastantes desafíos, entre otros la definición operativa de los conceptos que caen bajo la vertiente teórica y su desarrollo discriminativo. Por otra parte, para algunos, el abuso del discurso en relación con la falta de concreción operativa y el uso de conceptos indiscutibles (que nadie pondría en duda, como el de positivo representa un peligro a la credibilidad científica del ACP.

Perfil de susceptibilidade a antimicrobianos em amostras de cocos Gram-positivos, catalase negativos, isoladas de mastite subclínica bubalina Profile of antimicrobial susceptibility in strains of Gram positive cocos, negative catalase, isolated from buffalo subclinical mastitis

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Maria C.E. Vianni

2003-06-01

Full Text Available Estudou-se o perfil de susceptibilidade a antimicrobianos em cocos Gram-positivos catalase negativos (21 amostras de Lactococcus garvieae e 6 de Enterococcus gallinarum, isoladas do leite de fêmeas com mastite subclínica e pertencentes a uma população composta por seis rebanhos bubalinos localizados no Estado do Rio de Janeiro. O teste utilizado foi o da difusão de discos em agar Müller Hinton, segundo recomendações do National Committee for Clinical Laboratory Standards - NCCLS, tendo sido testados discos com ampicilina (10mg, cefalotina (30mg, cefotaxima (30mg, cefoxitina (30mg, cloranfenicol (30mg, eritromicina (15mg, gentamicina (10mg, nitrofurantoína (300mg, norfloxacina (10mg, penicilina (10 UI, tetraciclina (30mg e vancomicina (30mg. Os resultados evidenciaram que em se tratando de Lactococcus garvieae, o antimicrobiano mais eficiente foi o nitrofurantoína com 85,71% de sensibilidade, seguido da cefotaxima (61,90%, vancomicina (52,38%, norfloxacina (47,62% e cefalotina (47,62%. A maior resistência foi desenvolvida frente a penicilina e ampicilina, com 95,24% de resistênciapara os dois antimicrobianos testados. O perfil de susceptibilidade desenvolvido pelas amostras de Enterococcus gallinarum, mostrou baixa sensibilidade frente aos antimicrobianos testados, onde os maiores índices foram observados frente eritromicina e gentamicina, com 33,34% de sensibilidade para ambos; quanto à resistência desenvolvida, foi possível observar 100% de resistência com relação a vancomicina e tetraciclina, seguindo-se cloranfenicol, penicilina, ampicilina, cefoxitina, cefalotina, cefotaxima, norfloxacina e nitrofurantoína, todas evidenciando uma resistência de 83,33% das amostras testadas.The susceptibility of antimicrobials was studied in Gram positive and catalase negative cocci (21 samples of Lactococcus garvieae and 6 Enterococcus gallinarum, isolated from the milk of cows with subclinical mastitis, belonging to six buffalo herds in

Los sistemas positivos en la Ingeniería Positive systems in Engineering

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Andrés Quintero Zea

2010-01-01

Full Text Available Los sistemas positivos son sistemas en los que las variables de estado sólo toman valores positivos o no negativos. En este artículo de revisión se describe este tipo de sistemas por medio del establecimiento de sus principales propiedades estructurales y la exposición de algunas de sus aplicaciones.Positive systems are systems in which the state variables are always positive or non negative in value. In this review paper, we describe such systems through the establishment of its main structural properties and the exposure of some of its applications.

Gram staining.

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Coico, Richard

2005-10-01

Named after Hans Christian Gram who developed the method in 1884, the Gram stain allows one to distinguish between Gram-positive and Gram-negative bacteria on the basis of differential staining with a crystal violet-iodine complex and a safranin counterstain. The cell walls of Gram-positive organisms retain this complex after treatment with alcohol and appear purple, whereas gram-negative organisms decolorize following such treatment and appear pink. The method described here is useful for assessing bacterial contamination of tissue culture samples or for examining the Gram stain status and morphological features of bacteria isolated from mixed or isolated bacterial cultures.

Comportamiento organizacional positivo: las implicaciones del engagement en el entorno laboral

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Mercedes Almeida Quezada

2015-12-01

Full Text Available El presente estudio aborda el concepto de Comportamiento Organizacional Positivo como herramienta para potencializar las habilidades de los colaboradores dentro de una organización. Desde una perspectiva teórica, tiene como Objetivo analizar el constructo del engagement como elemento generador de compromiso y buen ambiente laboral. Profundizando en el documento, se describen las aristas que, llevadas a la práctica, permitirán una correcta ejecución de este modelo, repercutiendo de esta forma en resultados anuales positivos y en el aumento de la productividad. Colaboradores engaged son sinónimos de un buen provenir empresarial; el éxito radicará en los índices de motivación de cada uno de los miembros que componen la organización.

In vitro antimicrobial efficiency of a mouthwash containing triclosan/gantrez and sodium bicarbonate Eficiência antimicrobiana in vitro de um enxaguatório bucal contendo triclosan/gantrez e bicarbonato de sódio

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Juliana Rico Pires

2007-12-01

Full Text Available Several antiseptic substances have been used as adjuncts to routine mechanical procedures of oral hygiene, based on their antimicrobial effects. The objective of this study was to assess in vitro the antimicrobial efficiency of a mouthwash containing Triclosan/Gantrez and sodium bicarbonate in comparison to both positive and negative controls. Standard strain samples of Escherichia coli, Pseudomonas aeruginosa, Actinomyces viscosus and Bacillus subtilis were used. Samples of Streptococcus mutans and Gram-negative bacilli were collected from 20 volunteers (10 with a clinically healthy periodontium and 10 presenting biofilm-associated gingivitis. Evaluation of the antimicrobial activity was performed by determining the minimal inhibitory concentration (MIC. The results indicated that the test solution inhibited the growth of both Gram-negative and Gram-positive microorganisms from the volunteers’ saliva as well as that of the standard strains at the MIC dilution of 1:20, whereas the MIC dilution of 0.12% chlorhexidine against the same bacteria was 1:80. Thus, even though the tested mouthrinse solution presented an in-vitro antimicrobial activity superior to that of a placebo, it was inferior to that of chlorhexidine.Diversas substâncias antisépticas têm sido utilizadas como adjuntos aos procedimentos mecânicos rotineiros de higiene oral, com base em seus efeitos antimicrobianos. O objetivo deste estudo foi avaliar, in vitro, a eficiência antimicrobiana de um enxaguatório bucal contendo Triclosan/Gantrez e bicarbonato de sódio, em comparação a controles positivos e negativos. Linhagens padrão de Escherichia coli, Pseudomonas aeruginosa, Actinomyces viscosus e Bacillus subtilis foram utilizadas. Amostras de Streptococcus mutans e Bacilos Gram-negativos foram coletadas de 20 voluntários (10 com um periodonto clinicamente saudável e 10 com gengivite associada à presença de biofilme. A avaliação da atividade antimicrobiana foi

Bacterial, fungal and yeast contamination in six brands of irreversible hydrocolloid impression materials Contaminação por bactérias, fungos e leveduras em seis marcas comerciais de materiais de moldagem à base de hidrocolóide irreversível

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Luciana Assirati Casemiro

2007-06-01

Chromatic - 135 UFC/g; Hydrogum - 1.455 UFC/g; Kromopan - 840 UFC/g; e Greengel - 59 UFC/g. A coloração de Gram revelou a presença de bacilos Gram-positivos e cocos Gram-positivos. As bactérias Staphylococcus epidermidis, Bacillus subtilis, Bacillus sp., Bacillus coagulans, Bacillus licheniformis, Bacillus cereus, Micrococcus luteus e Nocardia sp.; os fungos filamentosos Aspergillus niger, Aspergillus flavus, Rhizopus sp., Neurospora sp.; e a levedura Candida sp. foram isolados. A contaminação detectada nos materiais aponta a necessidade de adoção de medidas para melhorar seu controle de qualidade microbiológica. O uso de materiais contaminados na boca contradiz os princípios básicos de controle de infecção-cruzada e pode representar um risco para pacientes debilitados ou imunocomprometidos.

Desarrollo y evaluación de una prueba de reacción en cadena de la polimerasa (PCR, utilizando la secuencia del gen hilA para diagnóstico de fiebre entérica por Salmonella spp.

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Miryan Margot Sánchez

2004-06-01

Full Text Available El diagnóstico de fiebre entérica por Salmonella spp. se basa en el aislamiento de la bacteria en hemocultivos el cual consume tiempo, no siempre está disponible y tiene poca utilidad en pacientes con tratamiento antibiótico previo. Por consiguiente, se hace necesario el desarrollo de una prueba rápida, sensible y específica para el diagnóstico de fiebre entérica. Salmonella spp. utiliza el gen hilA (componente de la isla de patogenicidad I para invadir células epiteliales y producir infección. Al usar la secuencia de este gen se diseñó una prueba de PCR para detectar la bacteria en sangre y se evaluó su sensibilidad, especificidad, valor predictivo positivo y valor predictivo negativo, utilizando la metodología prueba de una prueba. La prueba de oro fue el hemocultivo. Se estudiaron 34 individuos con sintomatología de fiebre entérica con aislamiento de Salmonella serotipo Typhi en hemocultivos; 35 individuos con sepsis por otros bacilos Gram negativos aislados de hemocultivo (Klebsiella pneumoniae, 9; Serratia marcescens, 5; Escherichia coli, 4; Pseudomonas aeruginosa, 9; Providencia alcalifaciens, 4, y Enterobacter cloacae, 4 y 150 muestras de sangre de voluntarios asintomáticos. La sensibilidad, especificidad, valor pronóstico positivo y valor pronóstico negativo de la PCR fue del 100%. El número mínimo de UFC/ml que la PCR detecta en sangre es de 10.

Educação linguística: análise do ensino de gramática em apostila de ensino

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Mata, Waldnylson Martiniano da

2010-01-01

Este trabalho foca a análise do aspecto gramatical de ensino na apostila de ensino do Sistema Positivo de Ensino do 7º ano (antiga 6ª série), sob a perspectiva da Educação Linguística. A pesquisa tem como objetivo responder duas questões: 1. A apostila de ensino desenvolve o ensino da gramática dentro da abordagem dos gêneros textuais, levando em consideração situações de uso? 2. De que modo o professor reflexivo pode fazer uso desse material: ele é apenas um instrutor que segue as...

Microbiota periodontal y microorganismos aislados de válvulas cardiacas en pacientes sometidos a cirugía de reemplazo de válvulas en una clínica de Cali, Colombia

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Sandra Moreno

2017-12-01

Conclusiones. La microbiota periodontal de pacientes sometidos a cirugía de reemplazo valvular estaba conformada por especies Gram negativas que han sido relacionadas con infecciones en tejidos extraorales; sin embargo, no se encontraron agentes patógenos periodontales en los tejidos de las válvulas. Aunque hubo muestras de estos tejidos y subgingivales, positivas para bacilos entéricos Gram negativos, no es posible asegurar que tuvieran el mismo origen filogenético.

Relações entre afetos positivos e negativos e os cinco fatores de personalidade

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Ana Paula Porto Noronha

2015-06-01

Full Text Available ResumoA presente pesquisa tem como objetivo verificar a existência de associações entre afetos positivos e negativos e os fatores de personalidade, sob a perspectiva do modelo dos Cinco Grandes Fatores. Colaboraram para o desenvolvimento do estudo 529 estudantes do Ensino Médio de escolas públicas e particulares com idades entre 14 a 27 anos (M = 16,0; DP = 1,48. No que se refere ao sexo 223 (42,2% eram homens e 306 (57,8%, mulheres. Foram aplicadas a Escala de Afetos Zanon (EAZ e a Bateria Fatorial de Personalidade (BFP. Dentre os resultados, a relação entre o fator neuroticismo e os afetos negativos gerou o coeficiente mais forte (r = 0,62. Em relação aos afetos positivos, a maior correlação se deu com o fator extroversão (r = 0,42. Verificou-se que neuroticismo é o melhor preditor dos afetos negativos, enquanto que extroversão dos afetos positivos. Os achados são discutidos à luz da literatura.

Comportamiento de bacilos gram negativos hospitalarios frente a germicidas iodóforos

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Penacca, Alejandra C.; Magariños, María del Carmen; Guillén, María G.

1999-01-01

Las infecciones hospitalarias han adquirido una relevante importancia debido a la aparición de microorganismos resistentes a numerosos agentes biocidas. La flora residente hospitalaria se encuentra frecuentemente en ropas, alimentos, equipos biomédicos e incluso soluciones de desinfectantes, en un ambiente relativamente pequeño donde conviven los pacientes que en la mayoría de los casos tienen disminuidos sus mecanismos naturales de defensa, quedando fácilmente expuestos a las distintas y num...

Procalcitonin levels in gram-positive, gram-negative, and fungal bloodstream infections.

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Leli, Christian; Ferranti, Marta; Moretti, Amedeo; Al Dhahab, Zainab Salim; Cenci, Elio; Mencacci, Antonella

2015-01-01

Procalcitonin (PCT) can discriminate bacterial from viral systemic infections and true bacteremia from contaminated blood cultures. The aim of this study was to evaluate PCT diagnostic accuracy in discriminating Gram-positive, Gram-negative, and fungal bloodstream infections. A total of 1,949 samples from patients with suspected bloodstream infections were included in the study. Median PCT value in Gram-negative (13.8 ng/mL, interquartile range (IQR) 3.4-44.1) bacteremias was significantly higher than in Gram-positive (2.1 ng/mL, IQR 0.6-7.6) or fungal (0.5 ng/mL, IQR 0.4-1) infections (P Gram-negatives from Gram-positives at the best cut-off value of 10.8 ng/mL and an AUC of 0.944 (95% CI 0.919-0.969, P Gram-negatives from fungi at the best cut-off of 1.6 ng/mL. Additional results showed a significant difference in median PCT values between Enterobacteriaceae and nonfermentative Gram-negative bacteria (17.1 ng/mL, IQR 5.9-48.5 versus 3.5 ng/mL, IQR 0.8-21.5; P Gram-negative from Gram-positive and fungal bloodstream infections. Nevertheless, its utility to predict different microorganisms needs to be assessed in further studies.

Los refuerzos positivos en el aula de infantil

OpenAIRE

Martínez Álvarez, Elena

2013-01-01

Este estudio ha sido realizado con el fin de analizar si el refuerzo positivo es un medio adecuado, o no para producir un mejor ambiente de trabajo en el aula de infantil, y si puede producir mejores resultados académicos, es decir, si puede mejorar el proceso de enseñanza – aprendizaje. Para poder contestar a esta cuestión vamos a analizar determinadas teorías e hipótesis relacionadas con este tema. Además vamos a poner en práctica una serie de actividades prácticas relacionadas con este ...

El diagnóstico positivo de autismo infantil

OpenAIRE

Velázquez Argota, Juana; Lozano Pérez, Teresa

1996-01-01

Se revisan los límites del síndrome autístico y la evolución del concepto de autismo infantil desde Kanner hasta las clasificaciones psiquiátricas más recientes. Se informan los resultados de nuestras investigaciones en el diagnóstico positivo del autismo infantil. La anamnesis remota es de poco valor, más relevantes para el diagnóstico constituyen el examen del paciente en el presente y las escalas de cuantificación del autismo (las cuales son de utilidad en el diagnóstico diferencial entre ...

Valores positivos e desenvolvimento do adolescente: perfil de jovens paulistanos Valores positivos y el desarrollo del adolescente: perfil de jóvenes paulistanos Positive values and adolescent development: a profile in São Paulo city

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Rosa M. S. de Macedo

2009-12-01

Full Text Available A presente pesquisa é parte do projeto "Os valores positivos e o desenvolvimento do adolescente", que se iniciou com a adaptação cultural do questionário Search Institute Profiles of Student Life. Seu objetivo foi mapear valores positivos presentes em adolescentes paulistanos, visando gerar informações que permitam planejar ações de promoção de saúde para jovens, suas famílias e comunidades. O instrumento adaptado foi aplicado em 2725 jovens paulistanos, de 11 a 19 anos, de ambos os sexos, provenientes de todas as regiões da cidade de São Paulo, categorizados de acordo com o Índice Paulista de Vulnerabilidade Social. Os resultados indicaram a presença um número baixo de valores, diferenças associadas mais à idade e ao sexo do que ao IPVS e, principalmente, a necessidade de revisão de nossas estratégias de promoção de saúde, que poderiam basear-se no desenvolvimento de valores positivos.La presente pesquisa es parte de lo proyeto "Los valores positivos y el desarrollo del adolescente" , que se ha iniciado com la adaptación cultural de lo instrumento Search Institute Profiles of Student Life. Lo objetivo fue mapear valores positivos presentes en jóvenes de la ciudad de São Paulo, para el desarrollo de acciones promotoras de salud para los jóvenes, sus famílias y comunidad. Lo instrumento adaptado fue aplicado a 2725 adolescentes, de 11 a 19 años, de ambos los sexos y en tres niveles de vulnerabilidad social: baja, mediana y alta. Los resultados han indicado la presencia de bajo número de valores positivos, diferencias más associadas a la edad y sexo y menos a la vulnerabilidad social y, especialmente, la necesidad de uma revisión de nuestras estratégias para la promoción de la salud, que podrían estar basadas en el desarrollo de valores positivos.This research is part of the project "The positive values and the adolescent development: from vulnerability to responsibility" that begun with the cultural adaptation

Procalcitonin Levels in Gram-Positive, Gram-Negative, and Fungal Bloodstream Infections

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Christian Leli

2015-01-01

Full Text Available Procalcitonin (PCT can discriminate bacterial from viral systemic infections and true bacteremia from contaminated blood cultures. The aim of this study was to evaluate PCT diagnostic accuracy in discriminating Gram-positive, Gram-negative, and fungal bloodstream infections. A total of 1,949 samples from patients with suspected bloodstream infections were included in the study. Median PCT value in Gram-negative (13.8 ng/mL, interquartile range (IQR 3.4–44.1 bacteremias was significantly higher than in Gram-positive (2.1 ng/mL, IQR 0.6–7.6 or fungal (0.5 ng/mL, IQR 0.4–1 infections (P<0.0001. Receiver operating characteristic analysis showed an area under the curve (AUC for PCT of 0.765 (95% CI 0.725–0.805, P<0.0001 in discriminating Gram-negatives from Gram-positives at the best cut-off value of 10.8 ng/mL and an AUC of 0.944 (95% CI 0.919–0.969, P<0.0001 in discriminating Gram-negatives from fungi at the best cut-off of 1.6 ng/mL. Additional results showed a significant difference in median PCT values between Enterobacteriaceae and nonfermentative Gram-negative bacteria (17.1 ng/mL, IQR 5.9–48.5 versus 3.5 ng/mL, IQR 0.8–21.5; P<0.0001. This study suggests that PCT may be of value to distinguish Gram-negative from Gram-positive and fungal bloodstream infections. Nevertheless, its utility to predict different microorganisms needs to be assessed in further studies.

Flora microbiana en elaborados de aceitunas verdes en la región de Murcia. Evolución cualitativa durante la fermentación.

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Guzmán Giménez, Ginés; Guevara, L. A.; Laencina Sánchez, José

1983-01-01

A lo largo del proceso normal de fermentación en salmuera se estudia en la región de Murcia la flora microbiana de cinco tipos de aceitunas (subvariedades Manzanilla Fina y Carrasqueña, Verdial, Hojiblanca y las variedades Cacereña) sometidas al tratamiento previo de «cocido». La flora heterogénea —que incluye bacterias Gram-negativas, bacterias lácticas y levaduras— con predominio de las poblaciones de bacilos Gram-negativos en los primeros días del proceso fermentati...

Caracterización de microorganismos involucrados en la descomposición de material vegetal consumido por Oso Andino Tremarctos ornatus (Ursidae

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Yusleni Fierro Toscano

2005-07-01

menores a seis meses. Cocobacilos Gram (+ solo aparecieron en hojas entre uno y tres meses y los bacilos Gram (+ exclusivamente en hojas de menos de un mes. Cocos y diplococos se presentaron únicamente en la muestra de hoja de cinco y seis meses en descomposición. Se encontraron cuatro morfotipos de hongos, de los cuales se identificaron Mucor spp. y Thricoderma spp. Los otros dos morfotipos no fueron identificados. Thricoderma spp. se encuentra asociado a por lo menos un hongo más.

Gram-negative, but not Gram-positive, bacteria elicit strong PGE2 production in human monocytes.

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Hessle, Christina C; Andersson, Bengt; Wold, Agnes E

2003-12-01

Gram-positive and Gram-negative bacteria induce different cytokine patterns in human mononuclear cells. We have seen that Gram-positives preferentially induce IL-12 and TNF-alpha, whereas Gram-negatives induce more IL-10, IL-6, and IL-8. In this study, we compared the capacity of these two groups of bacteria to induce PGE2. Monocytes stimulated with Gram-negative bacterial species induced much more PGE2 than did Gram-positive bacteria (5600 +/- 330 vs. 1700 +/- 670 pg/mL, p Gram-positive and Gram-negative bacteria. We suggest that Gram-positive and Gram-negative bacteria may stimulate different innate effector functions; Gram-positive bacteria promoting cell-mediated effector functions whereas Gram-negative bacteria inducing mediators inhibiting the same.

Prevalencia de microsporidios intestinales y otros enteroparásitos en pacientes con VIH positivo de Maracaibo, Venezuela

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Zulbey Rivero-Rodríguez

2013-12-01

Full Text Available Introducción. Desde 1985, los microsporidios se consideran parásitos causantes de infecciones emergentes y oportunistas en individuos inmunocomprometidos en todo el mundo. Objetivo. Detectar la presencia de microsporidios y otros enteroparásitos en pacientes con VIH/sida del Servicio Autónomo Hospital Universitario de Maracaibo (SAHUM, donde no existían estudios previos en este campo. Materiales y métodos. Las muestras fecales se analizaron mediante examen directo, método de concentración con formol-éter, coloración de Kinyoun y coloración Gram-cromotropo rápida. Se realizaron PCR separadas para diferenciar Entamoeba histolytica o Entamoeba dispar, cuando se observó el complejo E. histolytica/dispar al microscopio. Mediante historia clínica se obtuvo información del paciente. Resultados. De los 56 individuos participantes, 38 (67,86 % presentaron alguna especie parasitaria comensal o patógena en su muestra fecal. Predominaron los individuos portadores de especies parásitas patógenas (26/38. Fueron diagnosticados protozoos como Isospora belli (17,65 %, Blastocystis spp. (17,65 %, Cryptosporidium spp. (7,84 %, complejo Entamoeba histolytica/dispar (5,88 %, Entamoeba coli (3,92 %, Giardia lamblia (3,92 %, Endolimax nana (3,92 %, Cyclospora cayetanensis (3,92 % y Chilomastix mesnili (1,96 %. Entre los helmintos, Ascaris lumbricoides, Trichuris trichiura y Strongyloides stercoralis, presentaron un porcentaje de 27,27 % cada uno, e Hymenolepis nana, de 18,18 %. Solo se detectó E. histolytica en uno de los tres casos que presentaron el complejo al examen microscópico. Mediante Gram-cromotropo, 17 muestras evidenciaron esporas del filo Microsporidia, lo que equivale a un 33,33 % de prevalencia. Conclusión. Los microsporidios pueden ocupar el primer lugar de prevalencia en pacientes con VIH positivo, cuando se utilizan técnicas diagnósticas específicas.   doi: http://dx.doi.org/10.7705/biomedica.v33i4.1468

MODELOS DE LIDERAZGO POSITIVO: MARCO TEÓRICO Y LÍNEAS DE INVESTIGACIÓN

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Javier Blanch, Francisco Gil

2016-09-01

Full Text Available El objetivo de este artículo es doble, en primer lugar, se define el marco teórico del liderazgo positivo así como las razones de su aparición. Este surge vinculado al paradigma de la psicología organizacional positiva, en cuyo ámbito, se han desarrollado las diferentes formas de liderazgo que lo integran (i.e. transformacional, de servicio, espiritual, auténtico y positivo. Aunque el constructo no parece unívocamente delimitado, los diferentes tipos que se incluyen bajo esta denominaciónpresentan una gran afinidad y elementos comunes. En segundo lugar, se revisan aspectos prácticos vinculados a la investigación empírica que constatan el impacto de este tipo de liderazgo en las organizaciones y se subraya la relación entre estas formas de liderazgo y variables organizacionales positivas. Finalmente, se analizan futuras líneas de investigación para el desarrollo de este marco conceptual.

Methods for Confirming the Gram Reaction of Gram-variable Bacillus Species Isolated from Tobacco

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Morin A

2014-12-01

Full Text Available Bacillus is a predominant genus of bacteria isolated from tobacco. The Gram stain is the most commonly used and most important of all diagnostic staining techniques in microbiology. In order to help confirm the Gram positivity of Bacillus isolates from tobacco, three methods using the chemical differences of the cell wall and membrane of Gram-positive and Gram-negative bacteria were investigated: the KOH (potassium hydroxide, the LANA (L-alanine-4-nitroanilide, and the vancomycin susceptibility tests. When colonies of Gram-negative bacteria are treated with 3% KOH solution, a slimy suspension is produced, probably due to destruction of the cell wall and liberation of deoxyribonucleic acid (DNA. Gram-positive cell walls resist KOH treatment. The LANA test reveals the presence of a cell wall aminopeptidase that hydrolyzes the L-alanine-4-nitroanilide in Gram-negative bacteria. This enzyme is absent in Gram-positive bacteria. Vancomycin is a glycopeptide antibiotic inhibiting the cell wall peptido-glycan synthesis of Gram-positive microorganisms. Absence of lysis with KOH, absence of hydrolysis of LANA, and susceptibility to vancomycin were used with the Gram reaction to confirm the Gram positivity of various Bacillus species isolated from tobacco. B. laevolacticus excepted, all Bacillus species tested showed negative reactions to KOH and LANA tests, and all species were susceptible to vancomycin (5 and 30 µg.

The Causes of Post-Operative Meningitis: The Comparison Of Gram-Negative and Gram-Positive Pathogens.

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Kurtaran, Behice; Kuscu, Ferit; Ulu, Aslihan; Inal, Ayse Seza; Komur, Suheyla; Kibar, Filiz; Cetinalp, Nuri Eralp; Ozsoy, Kerem Mazhar; Arslan, Yusuf Kemal; Aksu, Hasan Salih; Tasova, Yesim

2017-06-20

In this study, we aim to determine the microbiological etiology in critically ill neurosurgical patients with nosocomial meningitis (NM) and show the impact of Gram-negative rods and differences of patient's characteristics, clinical and prognostic measures between Gram-negative and Gram-positive meningitis. In this prospective, one center study we reviewed all adult patients hospitalized during a 12-year period and identified pathogens isolated from post-neurosurgical cases of NM. Demographic, clinical, and treatment characteristics were noted from the medical records. Of the 134 bacterial NM patients, 78 were male and 56 were female, with a mean age of 46±15.9 and median age of 50 (18-80) years. 141 strains isolated; 82 (58.2%) were Gram negative, 59 (41.8%) were Gram positive. Most common isolated microorganism was Acinetobacter baumannii (%34.8). In comparison of mortality data shows that the patients who have meningitis with Gram-negative pathogens have higher mortality than with Gram positives (p=0.034). The duration between surgery and meningitis was shorter in Gram negative meningitis cases compared to others (p=0.045) but the duration between the diagnosis and death was shorter in Gram-positive meningitis cases compared to Gram negatives (p= 0.017). CSF protein and lactate level were higher and glucose level was lower in cases of NM with Gram negatives (p value were respectively, 0.022, 0.039 and 0.049). As conclusions; in NM, Gram-negative pathogens were seen more frequently; A.baumanni was the predominant pathogen; and NM caused by Gram negatives had worse clinical and laboratory characteristic and prognostic outcome than Gram positives.

Comportamiento organizacional positivo: las implicaciones del engagement en el entorno laboral

OpenAIRE

Mercedes Almeida Quezada; Isidro Fierro Ulloa

2015-01-01

El presente estudio aborda el concepto de Comportamiento Organizacional Positivo como herramienta para potencializar las habilidades de los colaboradores dentro de una organización. Desde una perspectiva teórica, tiene como Objetivo analizar el constructo del engagement como elemento generador de compromiso y buen ambiente laboral. Profundizando en el documento, se describen las aristas que, llevadas a la práctica, permitirán una correcta ejecución de este modelo, repercutiendo de esta forma ...

An optimized staining technique for the detection of Gram positive and Gram negative bacteria within tissue.

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Becerra, Sandra C; Roy, Daniel C; Sanchez, Carlos J; Christy, Robert J; Burmeister, David M

2016-04-12

Bacterial infections are a common clinical problem in both acute and chronic wounds. With growing concerns over antibiotic resistance, treatment of bacterial infections should only occur after positive diagnosis. Currently, diagnosis is delayed due to lengthy culturing methods which may also fail to identify the presence of bacteria. While newer costly bacterial identification methods are being explored, a simple and inexpensive diagnostic tool would aid in immediate and accurate treatments for bacterial infections. Histologically, hematoxylin and eosin (H&E) and Gram stains have been employed, but are far from optimal when analyzing tissue samples due to non-specific staining. The goal of the current study was to develop a modification of the Gram stain that enhances the contrast between bacteria and host tissue. A modified Gram stain was developed and tested as an alternative to Gram stain that improves the contrast between Gram positive bacteria, Gram negative bacteria and host tissue. Initially, clinically relevant strains of Pseudomonas aeruginosa and Staphylococcus aureus were visualized in vitro and in biopsies of infected, porcine burns using routine Gram stain, and immunohistochemistry techniques involving bacterial strain-specific fluorescent antibodies as validation tools. H&E and Gram stain of serial biopsy sections were then compared to a modification of the Gram stain incorporating a counterstain that highlights collagen found in tissue. The modified Gram stain clearly identified both Gram positive and Gram negative bacteria, and when compared to H&E or Gram stain alone provided excellent contrast between bacteria and non-viable burn eschar. Moreover, when applied to surgical biopsies from patients that underwent burn debridement this technique was able to clearly detect bacterial morphology within host tissue. We describe a modification of the Gram stain that provides improved contrast of Gram positive and Gram negative microorganisms within host

n-Gram-Based Text Compression

Science.gov (United States)

Duong, Hieu N.; Snasel, Vaclav

2016-01-01

We propose an efficient method for compressing Vietnamese text using n-gram dictionaries. It has a significant compression ratio in comparison with those of state-of-the-art methods on the same dataset. Given a text, first, the proposed method splits it into n-grams and then encodes them based on n-gram dictionaries. In the encoding phase, we use a sliding window with a size that ranges from bigram to five grams to obtain the best encoding stream. Each n-gram is encoded by two to four bytes accordingly based on its corresponding n-gram dictionary. We collected 2.5 GB text corpus from some Vietnamese news agencies to build n-gram dictionaries from unigram to five grams and achieve dictionaries with a size of 12 GB in total. In order to evaluate our method, we collected a testing set of 10 different text files with different sizes. The experimental results indicate that our method achieves compression ratio around 90% and outperforms state-of-the-art methods. PMID:27965708

n-Gram-Based Text Compression

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Vu H. Nguyen

2016-01-01

Full Text Available We propose an efficient method for compressing Vietnamese text using n-gram dictionaries. It has a significant compression ratio in comparison with those of state-of-the-art methods on the same dataset. Given a text, first, the proposed method splits it into n-grams and then encodes them based on n-gram dictionaries. In the encoding phase, we use a sliding window with a size that ranges from bigram to five grams to obtain the best encoding stream. Each n-gram is encoded by two to four bytes accordingly based on its corresponding n-gram dictionary. We collected 2.5 GB text corpus from some Vietnamese news agencies to build n-gram dictionaries from unigram to five grams and achieve dictionaries with a size of 12 GB in total. In order to evaluate our method, we collected a testing set of 10 different text files with different sizes. The experimental results indicate that our method achieves compression ratio around 90% and outperforms state-of-the-art methods.

Differential staining of bacteria: gram stain.

Science.gov (United States)

Moyes, Rita B; Reynolds, Jackie; Breakwell, Donald P

2009-11-01

In 1884, Hans Christian Gram, a Danish doctor, developed a differential staining technique that is still the cornerstone of bacterial identification and taxonomic division. This multistep, sequential staining protocol separates bacteria into four groups based on cell morphology and cell wall structure: Gram-positive cocci, Gram-negative cocci, Gram-positive rods, and Gram-negative rods. The Gram stain is useful for assessing bacterial contamination of tissue culture samples or for examining the Gram stain status and morphological features of bacteria isolated from mixed or isolated bacterial cultures. (c) 2009 by John Wiley & Sons, Inc.

Escala de afeto positivo e negativo para crianças: estudos de construção e validação

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Claudia Hofheinz Giacomoni

Full Text Available O objetivo deste estudo foi desenvolver uma Escala de Afeto Positivo e Negativo para Crianças. São apresentados dois estudos: de construção da escala, bem como de validação concorrente. Além disso, procurou-se avaliar o nível de afeto positivo e negativo das crianças dessa amostra, assim como, verificar possíveis diferenças entre sexos, faixa etária e tipo de escola. Participaram do estudo de construção da escala 661 crianças (52,2% meninos entre sete e 12 anos (m = 10,6 anos; d.p. = 1,7 anos de escolas públicas estaduais (54% e privadas (46% de Porto Alegre. A versão final da Escala de Afeto Positivo e Negativo é composta por 34 itens, 17 itens em cada subescala. Os coeficientes Alpha obtidos para as subescalas de Afeto Positivo (0,88 e de Afeto Negativo (0,84 apontam evidências de confiabilidade. Análises Fatoriais confirmaram a estrutura da escala através da solução de dois fatores em ambos estudos. A Escala também apresentou boas evidências de validação concorrente. Através de correlações coerentes com as apontadas pela literatura, os resultados indicam que a Escala de Afeto Negativo pode ser utilizada como instrumento de avaliação de desajustamento emocional. O desenvolvimento da Escala de Afeto Positivo e Negativo para Crianças incrementa o processo de elaboração de instrumentos para avaliarmos o bemestar subjetivo infantil.

EL LADO POSITIVO DEL PRESENTISMO

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Lynn Fendler

2009-01-01

Full Text Available El presentismo es visto generalmente como un mal necesario en historiografía. Este artículo explora lo positivo de esta inevitabilidad. Aplicando un enfoque filosófico al análisis discursivo en la tradición de la nueva historia cultural, se distingue -de una parte- entre un uso estratégico del presentismo, y -de otra- un enfoque racionalista en historia. El artículo concluye considerando algunas implicaciones políticas en historiografía de las explicaciones racionalistas y de las explicaciones estratégicamente presentistas. Los modos de comprensión racionalistas inscriben las expectativas del pasado en las visiones del futuro; asignando al historiador el papel de profeta; y perpetuando nociones de agentes ahistóricos. En contraste, las historias estratégicamente presentistas incorporan una orientación que deliberadamente emplea las lentes y perspectivas del presente en orden a tener en cuenta supuestos y perspectivas actuales. Cuando las asunciones son examinadas en relación a las perspectivas presentistas, dichos presupuestos sueltan su rienda en el pensamiento. Dado que el presentismo es inevitable, no debe ser desestimado por completo, sino que debe ser una cuestión sondeada y examinada críticamente. Con dicho foco, el presentismo estratégico en la historiografía debe posibilitar una reflexión sobre los límites de lo que es posible pensar.

Mid-infrared spectroscopic assessment of nanotoxicity in gram-negative vs. gram-positive bacteria.

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Heys, Kelly A; Riding, Matthew J; Strong, Rebecca J; Shore, Richard F; Pereira, M Glória; Jones, Kevin C; Semple, Kirk T; Martin, Francis L

2014-03-07

Nanoparticles appear to induce toxic effects through a variety of mechanisms including generation of reactive oxygen species (ROS), physical contact with the cell membrane and indirect catalysis due to remnants from manufacture. The development and subsequent increasing usage of nanomaterials has highlighted a growing need to characterize and assess the toxicity of nanoparticles, particularly those that may have detrimental health effects such as carbon-based nanomaterials (CBNs). Due to interactions of nanoparticles with some reagents, many traditional toxicity tests are unsuitable for use with CBNs. Infrared (IR) spectroscopy is a non-destructive, high throughput technique, which is unhindered by such problems. We explored the application of IR spectroscopy to investigate the effects of CBNs on Gram-negative (Pseudomonas fluorescens) and Gram-positive (Mycobacterium vanbaalenii PYR-1) bacteria. Two types of IR spectroscopy were compared: attenuated total reflection Fourier-transform infrared (ATR-FTIR) and synchrotron radiation-based FTIR (SR-FTIR) spectroscopy. This showed that Gram-positive and Gram-negative bacteria exhibit differing alterations when exposed to CBNs. Gram-positive bacteria appear more resistant to these agents and this may be due to the protection afforded by their more sturdy cell wall. Markers of exposure also vary according to Gram status; Amide II was consistently altered in Gram-negative bacteria and carbohydrate altered in Gram-positive bacteria. ATR-FTIR and SR-FTIR spectroscopy could both be applied to extract biochemical alterations induced by each CBN that were consistent across the two bacterial species; these may represent potential biomarkers of nanoparticle-induced alterations. Vibrational spectroscopy approaches may provide a novel means of fingerprinting the effects of CBNs in target cells.

Distribution of multi-resistant Gram-negative versus Gram-positive bacteria in the hospital inanimate environment.

Science.gov (United States)

Lemmen, S W; Häfner, H; Zolldann, D; Stanzel, S; Lütticken, R

2004-03-01

We prospectively studied the difference in detection rates of multi-resistant Gram-positive and multi-resistant Gram-negative bacteria in the inanimate environment of patients harbouring these organisms. Up to 20 different locations around 190 patients were surveyed. Fifty-four patients were infected or colonized with methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant enterococci (VRE) and 136 with multi-resistant Gram-negative bacteria. The environmental detection rate for MRSA or VRE was 24.7% (174/705 samples) compared with 4.9% (89/1827 samples) for multi-resistant Gram-negative bacteria (PGram-positive bacteria were isolated more frequently than Gram-negatives from the hands of patients (PGram-positive and Gram-negative isolates. Our results suggest that the inanimate environment serves as a secondary source for MRSA and VRE, but less so for Gram-negative bacteria. Thus, strict contact isolation in a single room with complete barrier precautions is recommended for MRSA or VRE; however, for multi-resistant Gram-negative bacteria, contact isolation with barrier precautions for close contact but without a single room seems sufficient. This benefits not only the patients, but also the hospital by removing some of the strain placed on already over-stretched resources.

Bacilos gram negativos, contaminantes más prevalentes en lentes de contacto blandos usados

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Castiblanco, Diana; Rodríguez, Martha Fabiola; Mayorga C., Myriam Teresa

2007-01-01

Las bacterias son los contaminantes más frecuentes de los lentes de contacto. Objetivo: identificar el tipo de depósitos microbiológicos en lentes de contacto blando (LCB) usados. Materiales y Métodos: 100 lentes de contacto blandos de usuarios o de prueba  de las ópticas, recolectándose 25 lentes para cada grupo de la FDA (Grupo1, 2, 3 y 4, según el contenido de agua e ionicidad del polímero). Los lentes se almacenaron por 20 días en sus estuches individuales hasta su estudio. A cada lente, ...

Gram positive and Gram negative bacteria differ in their sensitivity to cold plasma

Science.gov (United States)

Mai-Prochnow, Anne; Clauson, Maryse; Hong, Jungmi; Murphy, Anthony B.

2016-12-01

Cold atmospheric-pressure plasma (CAP) is a relatively new method being investigated for antimicrobial activity. However, the exact mode of action is still being explored. Here we report that CAP efficacy is directly correlated to bacterial cell wall thickness in several species. Biofilms of Gram positive Bacillus subtilis, possessing a 55.4 nm cell wall, showed the highest resistance to CAP, with less than one log10 reduction after 10 min treatment. In contrast, biofilms of Gram negative Pseudomonas aeruginosa, possessing only a 2.4 nm cell wall, were almost completely eradicated using the same treatment conditions. Planktonic cultures of Gram negative Pseudomonas libanensis also had a higher log10 reduction than Gram positive Staphylococcus epidermidis. Mixed species biofilms of P. aeruginosa and S. epidermidis showed a similar trend of Gram positive bacteria being more resistant to CAP treatment. However, when grown in co-culture, Gram negative P. aeruginosa was more resistant to CAP overall than as a mono-species biofilm. Emission spectra indicated OH and O, capable of structural cell wall bond breakage, were present in the plasma. This study indicates that cell wall thickness correlates with CAP inactivation times of bacteria, but cell membranes and biofilm matrix are also likely to play a role.

Estigma e discriminação: experiências de mulheres HIV positivo nos bairros populares de Maputo, Moçambique

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Andrade, Rosário Gregório; Iriart, Jorge Alberto Bernstein

2015-01-01

A epidemia de HIV/AIDS é um sério problema de saúde pública em Moçambique, que convive com altas taxas de prevalência do HIV. O impacto da epidemia é agravado pelo forte estigma que atinge as pessoas soropositivas. O objetivo deste estudo foi investigar, com base em uma perspectiva socioantropológica, a experiência de mulheres HIV positivo nos bairros populares de Maputo e como lidam com o estigma e a discriminação. Foram realizadas entrevistas semiestruturadas com dez mulheres HIV positivo, ...

Interesses profissionais e afetos positivos e negativos: estudo exploratório com estudantes de ensino médio Intereses profesionales y afectos positivos y negativos: estudio exploratorio con estudiantes de Enseñanza Secundaria Professional interests and affects positive and negative: exploratory study with youngers from high school

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Ana Paula Porto Noronha

2012-08-01

Full Text Available A Orientação Profissional enquanto área de intervenção e pesquisa tem buscado a compreensão de variáveis que interferem na tomada de decisão e no desenvolvimento de carreira. Trata-se de um estudo exploratório entre interesses profissionais e afetos positivos e negativos. Participaram 529 estudantes do ensino médio de escolas públicas e particulares com idades entre 14 a 27 anos (M=16; DP=1,48. No que se refere ao sexo, 223 (42,2% eram homens e 306 (57,8%, mulheres. Os instrumentos aplicados foram a EAZ - Escala de Afetos de Zanon e a EAP - Escala de Aconselhamento Profissional. Os participantes apresentaram maiores médias para afetos positivos, o que indica julgamento mais positivo da vida, de modo geral. A comparação entre os instrumentos revelou alguns coeficientes positivos e significativos, mas de baixa magnitude. Sugere-se que novos estudos sejam realizados com os construtos da Psicologia Positiva na orientação profissional e desenvolvimento de carreira.La Orientación Profesional como área de intervención e investigación ha buscado entender la comprensión de variables que interfieren en las decisiones y en el desarrollo de carrera. Se trata de un estudio exploratorio entre intereses profesionales y afectos positivos y negativos. Participaron 529 estudiantes de la Enseñanza Secundaria de escuelas públicas y privadas con edades entre14 a 27 años (M=16; DP= 1,48. En lo referente al sexo, 223 (42,2% eran hombres y 306 (57,8% mujeres. Los instrumentos aplicados fueron la Escala de Afetos de Zanon - EAZ y la Escala de Aconselhamento Profissional - EAP. Los participantes presentaron promedios mayores para los afectos positivos, lo que indica juicio más positivo de la vida, en general. La comparación entre los instrumentos mostró algunos coeficientes positivos y significativos, pero de magnitud baja. Se sugiere que nuevos estudios sean realizados con los constructos de la Psicología Positiva en la orientaci

The comparison of pyrosequencing molecular Gram stain, culture, and conventional Gram stain for diagnosing orthopaedic infections.

Science.gov (United States)

Kobayashi, Naomi; Bauer, Thomas W; Tuohy, Marion J; Lieberman, Isador H; Krebs, Viktor; Togawa, Daisuke; Fujishiro, Takaaki; Procop, Gary W

2006-08-01

We have developed a combined real-time PCR and pyrosequencing assay that successfully differentiated the vast majority of gram-positive and gram-negative bacteria when bacterial isolates were tested. The purpose of this study was to evaluate this assay on clinical specimens obtained from orthopedic surgeries, and to prospectively compare the results of "molecular Gram stain" with culture and conventional direct Gram stain. Forty-five surgical specimens were obtained from patients who underwent orthopedic surgery procedures. The DNA was extracted and a set of broad-range PCR primers that targeted a part of the 16S rDNA gene was used for pan-bacterial PCR. The amplicons were submitted for pyrosequencing and the resulting molecular Gram stain characteristics were recorded. Culture and direct Gram staining were performed using standard methods for all cases. Surgical specimens were reviewed histologically for all cases that had a discrepancy between culture and molecular results. There was an 86.7% (39/45) agreement between the traditional and molecular methods. In 12/14 (85.7%) culture-proven cases of bacterial infection, molecular Gram stain characteristics were in agreement with the culture results, while the conventional Gram stain result was in agreement only for five cases (35.7%). In the 31 culture negative cases, 27 cases were also PCR negative, whereas 4 were PCR positive. Three of these were characterized as gram negative and one as gram positive by this molecular method. Molecular determination of the Gram stain characteristics of bacteria that cause orthopedic infections may be achieved, in most instances, by this method. Further studies are necessary to understand the clinical importance of PCR-positive/culture-negative results.

Criterios de ensayo, interpretación e informe de las pruebas de sensibilidad a los antibióticos en los bacilos gram negativos no fermentadores de importancia clínica: recomendaciones de la Subcomisión de Antimicrobianos de la Sociedad Argentina de Bacteriología, Micología y Parasitología Clínicas, Asociación Argentina de Microbiología Antimicrobial susceptibility testing in clinically relevant non-fermenting gram-negative bacilli: recommendations from the Antimicrobial Agents Subcommittee of the Sociedad Argentina de Bacteriología, Micología y Parasitología Clínicas, Asociación Argentina de Microbiología

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Marcela Radice

2011-06-01

Full Text Available En este documento se dan a conocer una serie de recomendaciones para el ensayo, la lectura, la interpretación y el informe de las pruebas de sensibilidad a los antimicrobianos para los bacilos gram negativos no fermentadores (BGNNF que se aíslan en humanos. Se adoptaron como base las recomendaciones internacionales, las de la Subcomisión de Antimicrobianos de la Sociedad Argentina de Bacteriología, Micología y Parasitología Clínicas y las de un grupo de expertos invitados. Se incluye, además, la nomenclatura actualizada de los BGNNF y la descripción de algunas de sus características individuales, de sus resistencias naturales o habituales a los antimicrobianos de uso clínico y de los mecanismos responsables de tales resistencias. También se indican los agentes antimicrobianos que se deberían ensayar frente a las distintas especies, con la especificación de cuáles deberían ser informados, y su ubicación estratégica en las placas de cultivo para poder detectar los mecanismos de resistencia más frecuentes y relevantes. Por último, se detallan los métodos de detección y de confirmación fenotípica de la presencia de b-lactamasas emergentes en Argentina, como las carbapenemasas clases A y B.This document contains the recommendations for antimicrobial susceptibility testing of the clinically relevant non-fermenting gram-negative bacilli (NFGNB, adopted after conforming those from international committees to the experience of the Antimicrobial Agents Subcommittee members and invited experts. This document includes an update on NFGNB classification and description, as well as some specific descriptions regarding natural or frequent antimicrobial resistance and a brief account of associated resistance mechanisms. These recommendations not only suggest the antimicrobial drugs to be evaluated in each case, but also provide an optimization of the disk diffusion layout and a selection of results to be reported. Finally, this document

Fibrosis pulmonar asociada a vasculitis con anticuerpos anticitoplasmáticos positivos

OpenAIRE

Marcelo Fernández Casares; Alejandra González; Flavia Caputo; Yanina Bottinelli; Patricia Nastavi; Marcelo Zamboni

2012-01-01

Las complicaciones pulmonares más conocidas de las vasculitis con anticuerpos anticitoplasmáticos de los neutrófilos (ANCA) positivos (VAA), son la hemorragia alveolar, los granulomas y la estenosis de la vía aérea. En los últimos años han aparecido algunos informes aislados que muestran la asociación con fibrosis pulmonar (FP), sugiriendo que ésta sería otra complicación de las VAA. En este trabajo informamos dos casos con dicha asociación describiendo sus características clínicas, tomográfi...

Prognostic factors and monomicrobial necrotizing fasciitis: gram-positive versus gram-negative pathogens

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Hsu Wei-Hsiu

2011-01-01

Full Text Available Abstract Background Monomicrobial necrotizing fasciitis is rapidly progressive and life-threatening. This study was undertaken to ascertain whether the clinical presentation and outcome for patients with this disease differ for those infected with a gram-positive as compared to gram-negative pathogen. Methods Forty-six patients with monomicrobial necrotizing fasciitis were examined retrospectively from November 2002 to January 2008. All patients received adequate broad-spectrum antibiotic therapy, aggressive resuscitation, prompt radical debridement and adjuvant hyperbaric oxygen therapy. Eleven patients were infected with a gram-positive pathogen (Group 1 and 35 patients with a gram-negative pathogen (Group 2. Results Group 2 was characterized by a higher incidence of hemorrhagic bullae and septic shock, higher APACHE II scores at 24 h post-admission, a higher rate of thrombocytopenia, and a higher prevalence of chronic liver dysfunction. Gouty arthritis was more prevalent in Group 1. For non-survivors, the incidences of chronic liver dysfunction, chronic renal failure and thrombocytopenia were higher in comparison with those for survivors. Lower level of serum albumin was also demonstrated in the non-survivors as compared to those in survivors. Conclusions Pre-existing chronic liver dysfunction, chronic renal failure, thrombocytopenia and hypoalbuminemia, and post-operative dependence on mechanical ventilation represent poor prognostic factors in monomicrobial necrotizing fasciitis. Patients with gram-negative monobacterial necrotizing fasciitis present with more fulminant sepsis.

Gram staining for the treatment of peritonsillar abscess.

Science.gov (United States)

Takenaka, Yukinori; Takeda, Kazuya; Yoshii, Tadashi; Hashimoto, Michiko; Inohara, Hidenori

2012-01-01

Objective. To examine whether Gram staining can influence the choice of antibiotic for the treatment of peritonsillar abscess. Methods. Between 2005 and 2009, a total of 57 cases of peritonsillar abscess were analyzed with regard to cultured bacteria and Gram staining. Results. Only aerobes were cultured in 16% of cases, and only anaerobes were cultured in 51% of cases. Mixed growth of aerobes and anaerobes was observed in 21% of cases. The cultured bacteria were mainly aerobic Streptococcus, anaerobic Gram-positive cocci, and anaerobic Gram-negative rods. Phagocytosis of bacteria on Gram staining was observed in 9 cases. The bacteria cultured from these cases were aerobic Streptococcus, anaerobic Gram-positive cocci, and anaerobic Gram-negative rods. The sensitivity of Gram staining for the Gram-positive cocci and Gram-negative rods was 90% and 64%, respectively. The specificity of Gram staining for the Gram-positive cocci and Gram-negative rods was 62% and 76%, respectively. Most of the Gram-positive cocci were sensitive to penicillin, but some of anaerobic Gram-negative rods were resistant to penicillin. Conclusion. When Gram staining shows only Gram-positive cocci, penicillin is the treatment of choice. In other cases, antibiotics effective for the penicillin-resistant organisms should be used.

Evaluación citológica y microbiológica de lavados uterinos en bovinos con problemas reproductivos (estudio preliminar

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Milena Sánchez L.

2011-12-01

Full Text Available Objetivo. Determinar las características citológicas y microbiológicas de lavados uterinos de bajo volúmen en hembras con problemas reproductivos en dos hatos del Altiplano Cundiboyacense. Materiales y métodos. Se evaluaron 21 muestras de lavados uterinosde vacas con historia de problemas reproductivos procedentes de dos hatos lecheros, en el primer hato ubicado en Sibaté (Cundinamarca se muestrearon 10 animales y en el segundo ubicado en Ventaquemada (Boyacá se obtuvieron las 11 muestras restantes. Se realizó evaluación macroscópica y microscópica de cada uno de los lavados uterinos; para la evaluación citológica se utilizaron las tinciones de Gram y Wright. La determinación de la flora bacteriana se realizó mediante técnicas estándar en microbiología para la identificaciónde bacterias no exigentes, adicionalmente se realizaron pruebas de sensibilidad por la técnica de difusión de Kirby-bauer. Resultados. En la citología se observaron bacilos y cocos gram positivos, células epiteliales de descamación uterina (CEDU y respuesta inflamatoria (RI mediada por polimorfonucleares (PMN. Los aislamientos bacterianos correspondieron a Lactobacillus sp como flora bacteriana normal del tracto genital (16.66% y Klebsiella sp como flora acompañante (16.66%; adicionalmente se aislaron bacterias patógenas causantes de problemas reproductivos como Streptococcus sp. β hemolítico (33.33%, Streptococcus sp α hemolítico (50% y Streptococcus sp. γ hemolítico (50% y Arcanobacterium pyogenes (Corynebacterium-Actinomyces pyogenes (16.66%; en un 9.52% de las muestras se observaron espiroquetas. Conclusiones. Se observó una relación directa entre el aspecto macroscópico de los lavados uterinos, la respuesta citológica y el aislamiento de bacterias.

Actinomicosis: presentación de un caso y revisión del tema con énfasis en los aspectos orales Actinomycosis in children with emphasis on oral aspects

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Luis Fernando Gómez Jiménez

1997-04-01

Full Text Available En el presente artículo se actualizan los conocimientos sobre actinomicosis y se presenta el caso de un niño con la forma torácica de dicha entidad. La actinomicosis es una infección infrecuente que puede afectar cualquier parte del cuerpo; los Actinomyces son bacilos o filamentos gram positivos que forman parte de la flora endógena de las mucosas en especial las de las cavidades oral e intestinal. Su comportamiento es insidioso pero en oportunidades tiene expresión aguda, fistulización a piel y cicatrización con fibrosis. Los llamados gránulos de azufre son una característica macroscópica del exudado que contribuye al diagnóstico de laboratorio. La infección inicial para la forma cervicofacial suele provenir de la cavidad oral y extenderse a la vecindad o ser aspirada a los pulmones. El tratamiento de elección es la penicilina, inicialmente endovenosa y seguidamente oral por un lapso no menor de 6 meses. Algunas formas requieren manejo quirúrgico. We report the case of a child with thoracic actinomycosis and review this disease. Actinomycosis is a rare infection that can affect any part of the body; Actinomyces are gram positive bacilli or filaments belonging to the endogenous flora of the mUCOUS membranes, specially that of the oral cavity and the intestinal tract. Actinomycosis usually behaves as an insidioUS disease but may ocassionally have acute expressions with fistulization to the skin and fibroUS healing during resolution. The So called sulfur granules are an important macroscopic detail that helps establish the diagnosis. Actinomyces infections usually start in the oral cavity for the cervicofacial form and then spread to contiguous tissues or to the lungs via aspiration. Penicillin is the drug of choice and surgical drainage may become necessary.

Comparative activity of ceftobiprole against Gram-positive and Gram-negative isolates from Europe and the Middle East: the CLASS study.

Science.gov (United States)

Rossolini, Gian M; Dryden, Matthew S; Kozlov, Roman S; Quintana, Alvaro; Flamm, Robert K; Läuffer, Jörg M; Lee, Emma; Morrissey, Ian; CLASS Study Group

2011-01-01

to assess the in vitro activity of ceftobiprole and comparators against a recent collection of Gram-positive and Gram-negative pathogens, in order to detect potential changes in susceptibility patterns, and to evaluate the Etest assay for ceftobiprole susceptibility testing. contemporary Gram-positive and Gram-negative isolates (excluding extended-spectrum β-lactamase-producing isolates) from across Europe and the Middle East were collected, and their susceptibility to ceftobiprole, vancomycin, teicoplanin, linezolid, ceftazidime and cefepime was assessed using the Etest method. Quality testing [using Etest and broth microdilution (BMD)] was conducted at a central reference laboratory. some 5041 Gram-positive and 4026 Gram-negative isolates were included. Against Gram-positive isolates overall, ceftobiprole had the lowest MIC50 (0.5 mg/L), compared with 1 mg/L for its comparators (vancomycin, teicoplanin and linezolid). Against methicillin-resistant Staphylococcus aureus, all four agents had a similar MIC90 (2 mg/L), but ceftobiprole had a 4-fold better MIC90 (0.5 mg/L) against methicillin-susceptible strains. Only 38 Gram-positive isolates were confirmed as ceftobiprole resistant. Among Gram-negative strains, 86.9%, 91.7% and 95.2% were susceptible to ceftobiprole, ceftazidime and cefepime, respectively. Pseudomonas aeruginosa was less susceptible to all three antimicrobials than any other Gram-negative pathogen. There was generally good agreement between local Etest results and those obtained at the reference laboratory (for ceftobiprole: 86.8% with Gram-negatives; and 94.7% with Gram-positives), as well as between results obtained by BMD and Etest methods (for ceftobiprole: 98.2% with Gram-negatives; and 98.4% with Gram-positives). ceftobiprole exhibits in vitro activity against a wide range of Gram-positive and Gram-negative pathogens, including multidrug-resistant strains. No changes in its known susceptibility profile were identified.

Protamine-induced permeabilization of cell envelopes of gram-positive and gram-negative bacteria

DEFF Research Database (Denmark)

Johansen, Charlotte; Verheul, A.; Gram, Lone

1997-01-01

carboxyfluorescein and ATP after 2 to 5 min. Maximum antibacterial activity was reached at alkaline pH and in the absence of divalent cations. The efficient permeabilization of cell envelopes of both gram-positive and gram-negative bacteria suggests that protamine causes a general disruption of the cell envelope...

Numerical Gram-Schmidt orthonormalization

International Nuclear Information System (INIS)

Werneth, Charles M; Dhar, Mallika; Maung, Khin Maung; Sirola, Christopher; Norbury, John W

2010-01-01

A numerical Gram-Schmidt orthonormalization procedure is presented for constructing an orthonormal basis function set from a non-orthonormal set, when the number of basis functions is large. This method will provide a pedagogical illustration of the Gram-Schmidt procedure and can be presented in classes on numerical methods or computational physics.

Probing interaction of Gram-positive and Gram-negative bacterial cells with ZnO nanorods

Energy Technology Data Exchange (ETDEWEB)

Jain, Aanchal; Bhargava, Richa; Poddar, Pankaj, E-mail: p.poddar@ncl.res.in

2013-04-01

In the present work, the physiological effects of the ZnO nanorods on the Gram positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Escherichia coli and Aerobacter aerogenes) bacterial cells have been studied. The analysis of bacterial growth curves for various concentrations of ZnO nanorods indicates that Gram positive and Gram negative bacterial cells show inhibition at concentrations of ∼ 64 and ∼ 256 μg/mL respectively. The marked difference in susceptibility towards nanorods was also validated by spread plate and disk diffusion methods. In addition, the scanning electron micrographs show a clear damage to the cells via changed morphology of the cells from rod to coccoid etc. The confocal optical microscopy images of these cells also demonstrate the reduction in live cell count in the presence of ZnO nanorods. These, results clearly indicate that the antibacterial activity of ZnO nanorods is higher towards Gram positive bacterium than Gram negative bacterium which indicates that the structure of the cell wall might play a major role in the interaction with nanostructured materials and shows high sensitivity to the particle concentration. Highlights: ► Effect of ZnO nanorods on the growth cycles of four bacterial strains. ► A relation has been established between growth rate of bacteria and concentration. ► Serious damage in the morphology of bacterial cells in the presence of ZnO nanorods. ► Microscopic studies to see the time dependent effect on bacterial cells.

Relacionamentos de Marketing em Empresas Varejistas: Aspectos Positivos e Negativos

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Cléria Donizete da Silva Lourenço

2013-09-01

Full Text Available O objetivo deste trabalho é compreender as relações de trocas comerciais sob a ótica dos clientes, funcionários e proprietários de empresas varejistas. A pesquisa, de natureza qualitativa, foi feita utilizando-se como método a etnografia. Os dados foram coletados em cinco empresas varejistas de um município de pequeno porte no Sul de Minas Gerais – um supermercado, uma farmácia, uma panificadora, um posto de combustíveis e uma loja de hortifrutigranjeiros – durante o período de um ano (dez/2008 a dez/2009. A observação participante e a entrevista em profundidade foram utilizadas como técnicas de coleta de dados. Para tratamento dos mesmos, utilizou-se a análise de conteúdo. Por meio da análise empreendida, identificou-se que os relacionamentos de marketing são compostos tanto por aspectos positivos quanto negativos. Contudo, os aspectos positivos são predominantes, especialmente pelo fato de que o cultivo de relacionamentos nas empresas varejistas analisadas é uma ocorrência natural, podendo, portanto, ser caracterizado como “genuíno”. Em termos teóricos, uma das principais descobertas feitas nesta pesquisa é que o relacionamento de marketing pode trazer também implicações negativas para as empresas confirmando as descobertas de Grayson and Ambler (1999 quando eles afirmam que o marketing de relacionamento pode trazer benefícios, mas também desvantagens inerentes. Em termos gerenciais, há que se ressaltar o papel fundamental que os funcionários exercem na construção de relacionamentos duradouros. Sendo assim, maior atenção deveria ser dispensada ao desenvolvimento de habilidades de relacionamentos daqueles que estão face a face com o cliente. DOI: 10.5585/remark.v12i3.2513

Gram staining apparatus for space station applications

Science.gov (United States)

Molina, T. C.; Brown, H. D.; Irbe, R. M.; Pierson, D. L.

1990-01-01

A self-contained, portable Gram staining apparatus (GSA) has been developed for use in the microgravity environment on board the Space Station Freedom. Accuracy and reproducibility of this apparatus compared with the conventional Gram staining method were evaluated by using gram-negative and gram-positive controls and different species of bacteria grown in pure cultures. A subsequent study was designed to assess the performance of the GSA with actual specimens. A set of 60 human and environmental specimens was evaluated with the GSA and the conventional Gram staining procedure. Data obtained from these studies indicated that the GSA will provide the Gram staining capability needed for the microgravity environment of space.

Antimicrobial Activity of Carbon Nanoparticles Isolated from Natural Sources against Pathogenic Gram-Negative and Gram-Positive Bacteria

International Nuclear Information System (INIS)

Varghese, S.; Jose, S.; Varghese, S.; Kuriakose, S.; Jose, S.

2013-01-01

This paper describes the isolation of carbon nanoparticles (CNPs) from kitchen soot, characterization of the CNPs by UV/visible spectroscopy, SEM and XRD, and their antimicrobial action. The antibacterial activity of the isolated carbon nanoparticles was tested against various pathogenic bacterial strains such as Gram-negative Proteus refrigere and Pseudomonas aeruginosa and Gram-positive Staphylococcus aureus and Streptococcus haemolyticus. The inhibition zones were measured, and it was found that the carbon nanoparticles isolated from natural sources are active against these Gram-negative and Gram-positive bacterial strains

Discursos sobre la responsabilidad sexual en hombres VIH-positivos que tienen sexo con hombres

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Percy Fernández-Dávila

2013-01-01

Full Text Available Fundamentos: Entre los hombres VIH-positivos que tienen sexo con hombres (HSH VIH-positivos se vienen reportando elevadas tasas de prácticas sexuales de riesgo, lo que lleva a preguntarnos sobre las ideas del cuidado sexual que existen en este colectivo para evitar la transmisión y/o reinfección del VIH y otras ITS. Este estudio buscó comprender los discursos que sobre la responsabilidad sexual tienen es- tos hombres. Método: Se realizó un estudio cualitativo. Participaron 78 hombres (27-65 años, 35 en entrevistas individuales y 43 en cinco grupos de discusión, en las ciudades de Barcelona, Madrid y Palma de Mallorca, entre 2007 y 2008. Se estableció como criterio de selección que hubieran transcurrido 18 meses desde el diagnóstico del VIH. El enfoque utilizado para analizar los datos fue la Teoría Fundamentada. Resultados: Entre los participantes se diferenciaron tres tipos de discurso respecto a la responsabilidad sexual: (1 Responsabilidad única: el sujeto seropositivo es el que debe cuidarse para cuidar a otros. Se fundamenta en un posicionamiento ético (altruista en el que el deber y la obligación por proteger a los otros está por encima de todo. (2 Responsabilidad compartida: ambas partes deciden y/o consienten tener una relación sexual de riesgo aunque los que esgrimen este discurso en la práctica terminen asumiendo toda la carga de la responsabilidad. Y (3 Responsabilidad individual: cada uno vela por el cuidado de sí mismo, aunque el tipo de vínculo emocional con otras personas podría afectar la decisión de cuidarse o no (existe algún tipo de compromiso de proteger a alguien cuando se siente algo por esa persona. Conclusiones: La conducta de cuidado sexual de los HSH VIH-positivos estuvo orientaba en base a los tres discursos sobre la responsabilidad. Estos discursos estuvieron influenciados por diversos factores: conciencia moral, el contexto sexual, el tipo de pareja sexual y el revelamiento del seroestatus.

Veillonella, Firmicutes: Microbes disguised as Gram negatives

DEFF Research Database (Denmark)

Vesth, Tammi Camilla; Ozen, Asli; Andersen, Sandra Christine

2013-01-01

Negativicutes, including the genus Veillonella, stain Gram negative. Veillonella are among the most abundant organisms of the oral and intestinal microflora of animals and humans, in spite of being strict anaerobes. In this work, the genomes of 24 Negativicutes, including eight Veillonella spp., are compared......, with the exception of a shared LPS biosynthesis pathway. The clade within the class Negativicutes to which the genus Veillonella belongs exhibits unique properties, most of which are in common with Gram-positives and some with Gram negatives. They are only distantly related to Clostridia, but are even less closely...... related to Gram-negative species. Though the Negativicutes stain Gram-negative and possess two membranes, the genome and proteome analysis presented here confirm their place within the (mainly) Gram positive phylum of the Firmicutes. Further studies are required to unveil the evolutionary history...

Evaluación neurológica y neurosicológica de niños VIH positivos y VIH negativos, en Medellín, Colombia, 2007

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Gabriel Jaime Vélez Rengifo

2008-11-01

Full Text Available INTRODUCCIÓN: este estudio describe algunas características cognitivas y físicas de un grupo de 23 niños infectados con el VIH y uno de 25 niños no infectados con dicho virus, pareados por edad y sexo, en Medellín, Colombia. Se hicieron examen neurológico y pruebas neurosicológicas como WISC III, McCarthy, Wisconsin, Stroop, TMT y curva de memoria visual. OBJETIVO: describir las características neurológicas y neurosicológicas de un grupo de niños con VIH y compararlas con las de un grupo de niños VIH negativos. MÉTODO: se realizo un estudio descriptivo de corte tranversal. RESULTADOS: el desempeño cognitivo de los niños mayores de 6 años y VIH positivos tuvo una media de 88,58 y el del grupo VIH negativo de 88,36 (p = 0,973. Once de 17 pacientes (67,4% mayores de 6 años VIH positivos tuvieron desempeño cognitivo promedio (90-109. La media del perímetro cefálico del grupo de niños VIH positivos fue 51 cm y la de los niños VIH negativos, 51,12 cm (p = 0,878; no se encontró microcefalia en los niños VIH positivos. Las demás pruebas tampoco mostraron diferencias significativas entre ambos grupos. CONCLUSIONES: en comparación con los niños VIH negativos, los VIH positivos estudiados no presentan microcefalia, disminución del desempeño cognitivo ni otras alteraciones neurosicológicas, lo que puede explicarse por un tratamiento farmacológico adecuado y continuo, pero es ideal hacerles seguimiento para conocer mejor el impacto de la enfermedad.

Dustborne and airborne gram-positive and gram-negative bacteria in high versus low ERMI homes

Science.gov (United States)

The study aimed at investigating Gram-positive and Gram-negative bacteria in moldy and non-moldy homes, as defined by the home's Environmental Relative Moldiness Index (ERMI) value. The ERMI values were determined from floor dust samples in 2010 and 2011 and homes were classified...

Diagnosing periprosthetic infection: false-positive intraoperative Gram stains.

Science.gov (United States)

Oethinger, Margret; Warner, Debra K; Schindler, Susan A; Kobayashi, Hideo; Bauer, Thomas W

2011-04-01

Intraoperative Gram stains have a reported low sensitivity but high specificity when used to help diagnose periprosthetic infections. In early 2008, we recognized an unexpectedly high frequency of apparent false-positive Gram stains from revision arthroplasties. The purpose of this report is to describe the cause of these false-positive test results. We calculated the sensitivity and specificity of all intraoperative Gram stains submitted from revision arthroplasty cases during a 3-month interval using microbiologic cultures of the same samples as the gold standard. Methods of specimen harvesting, handling, transport, distribution, specimen processing including tissue grinding/macerating, Gram staining, and interpretation were studied. After a test modification, results of specimens were prospectively collected for a second 3-month interval, and the sensitivity and specificity of intraoperative Gram stains were calculated. The retrospective review of 269 Gram stains submitted from revision arthroplasties indicated historic sensitivity and specificity values of 23% and 92%, respectively. Systematic analysis of all steps of the procedure identified Gram-stained but nonviable bacteria in commercial broth reagents used as diluents for maceration of periprosthetic membranes before Gram staining and culture. Polymerase chain reaction and sequencing showed mixed bacterial DNA. Evaluation of 390 specimens after initiating standardized Millipore filtering of diluent fluid revealed a reduced number of positive Gram stains, yielding 9% sensitivity and 99% specificity. Clusters of false-positive Gram stains have been reported in other clinical conditions. They are apparently rare related to diagnosing periprosthetic infections but have severe consequences if used to guide treatment. Even occasional false-positive Gram stains should prompt review of laboratory methods. Our observations implicate dead bacteria in microbiologic reagents as potential sources of false-positive Gram

A distinção entre o sentido negativo e positivo da liberdade na Fundamentação da Metafísica dos Costumes

OpenAIRE

Hipolito, Marco André de Freitas

2011-01-01

O presente trabalho pretende analisar a distinção entre o conceito de liberdade em sentido negativo e o de liberdade em sentido positivo, enfatizando, também, os conceitos que Kant utiliza para fundamentar a moral sob a idéia da liberdade em sentido positivo. No primeiro capítulo analisamos a tese kantiana de que somente mediante uma boa vontade haveria a possibilidade de agir moralmente. A boa vontade é tida por Kant como um princípio do querer, que deve ser determinado por si...

Identificação e genotipagem de Mycobacterium bovis em bovinos positivos no teste intradérmico para tuberculose em Mato Grosso do Sul

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Daniela de O. Cazola

2015-02-01

Full Text Available Neste estudo, realizou-se genotipagem de isolados de Mycobacterium bovis, provenientes de amostras de tecidos de bovinos positivos no teste cervical comparativo (TCC para tuberculose em Mato Grosso do Sul, por meio da técnica de spoligotyping. Tecidos de 13 bovinos positivos, oriundos de diferentes municípios do estado, foram cultivados em meio de Stonebrink. As colônias resultantes foram submetidas à coloração de Ziehl-Neelsen e todos os isolados apresentaram características tintoriais de BAAR. Os 13 isolados de BAAR foram identificados por PCR multiplex (mPCR. O gene hsp65 foi alvo para identificação de Mycobacterium spp, a sequência de inserção IS6110 foi alvo para identificação de complexo Mycobacterium tuberculosis (CMT e a região rvd1rv2031c foi explorada para detecção de M. bovis. Os isolados micobacterianos foram genotipados pela técnica de spoligotyping. Dos 13 bovinos, sete tinham pelo menos uma lesão sugestiva de tuberculose em linfonodos retrofaríngeos, parotídeos e pulmonares ou no pulmão, e em seis não foram encontradas lesões visíveis sugestivas da doença. Na mPCR, 11/13 (84,6% isolados foram positivos para Mycobacterium spp; 8/13 (61,5% positivos para CMT e 7/13 (53,8% positivos para M. bovis. Com base no spoligotyping, oito isolados de BAAR foram agrupados dentro de três diferentes agrupamentos de genótipos e uma amostra remanescente apresentou perfil único, sendo quatro isolados com padrão de espoligotipo SB0121, dois SB1145, dois SB0881 e um SB0140. A técnica de spoligotyping demonstrou que há diversidade genética entre os espoligotipos presentes no estado de Mato Grosso do Sul, embora predomine o perfil SB0121

Multicenter Assessment of Gram Stain Error Rates.

Science.gov (United States)

Samuel, Linoj P; Balada-Llasat, Joan-Miquel; Harrington, Amanda; Cavagnolo, Robert

2016-06-01

Gram stains remain the cornerstone of diagnostic testing in the microbiology laboratory for the guidance of empirical treatment prior to availability of culture results. Incorrectly interpreted Gram stains may adversely impact patient care, and yet there are no comprehensive studies that have evaluated the reliability of the technique and there are no established standards for performance. In this study, clinical microbiology laboratories at four major tertiary medical care centers evaluated Gram stain error rates across all nonblood specimen types by using standardized criteria. The study focused on several factors that primarily contribute to errors in the process, including poor specimen quality, smear preparation, and interpretation of the smears. The number of specimens during the evaluation period ranged from 976 to 1,864 specimens per site, and there were a total of 6,115 specimens. Gram stain results were discrepant from culture for 5% of all specimens. Fifty-eight percent of discrepant results were specimens with no organisms reported on Gram stain but significant growth on culture, while 42% of discrepant results had reported organisms on Gram stain that were not recovered in culture. Upon review of available slides, 24% (63/263) of discrepant results were due to reader error, which varied significantly based on site (9% to 45%). The Gram stain error rate also varied between sites, ranging from 0.4% to 2.7%. The data demonstrate a significant variability between laboratories in Gram stain performance and affirm the need for ongoing quality assessment by laboratories. Standardized monitoring of Gram stains is an essential quality control tool for laboratories and is necessary for the establishment of a quality benchmark across laboratories. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

How bacterial cell division might cheat turgor pressure - a unified mechanism of septal division in Gram-positive and Gram-negative bacteria.

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Erickson, Harold P

2017-08-01

An important question for bacterial cell division is how the invaginating septum can overcome the turgor force generated by the high osmolarity of the cytoplasm. I suggest that it may not need to. Several studies in Gram-negative bacteria have shown that the periplasm is isoosmolar with the cytoplasm. Indirect evidence suggests that this is also true for Gram-positive bacteria. In this case the invagination of the septum takes place within the uniformly high osmotic pressure environment, and does not have to fight turgor pressure. A related question is how the V-shaped constriction of Gram-negative bacteria relates to the plate-like septum of Gram-positive bacteria. I collected evidence that Gram-negative bacteria have a latent capability of forming plate-like septa, and present a model in which septal division is the basic mechanism in both Gram-positive and Gram-negative bacteria. © 2017 WILEY Periodicals, Inc.

Antibacterial Activity of Silver-Graphene Quantum Dots Nanocomposites Against Gram-Positive and Gram-Negative Bacteria

Science.gov (United States)

Habiba, Khaled (Inventor); Makarov, Vladimir (Inventor); Weiner, Brad R (Inventor); Morell, Gerardo (Inventor)

2018-01-01

The invention provides a composite of silver nanoparticles decorated with graphene quantum dots (Ag-GQDs) using pulsed laser synthesis. The nanocomposites were functionalized with polyethylene glycol (PEG). A concentration of 150 .mu.g/mL of Ag-GQDs, a non-toxic level for human cells, exhibits strong antibacterial activity against both Gram-Positive and Gram-Negative Bacteria.

Comparing Medline citations using modified N-grams

Science.gov (United States)

Nawab, Rao Muhammad Adeel; Stevenson, Mark; Clough, Paul

2014-01-01

Objective We aim to identify duplicate pairs of Medline citations, particularly when the documents are not identical but contain similar information. Materials and methods Duplicate pairs of citations are identified by comparing word n-grams in pairs of documents. N-grams are modified using two approaches which take account of the fact that the document may have been altered. These are: (1) deletion, an item in the n-gram is removed; and (2) substitution, an item in the n-gram is substituted with a similar term obtained from the Unified Medical Language System  Metathesaurus. N-grams are also weighted using a score derived from a language model. Evaluation is carried out using a set of 520 Medline citation pairs, including a set of 260 manually verified duplicate pairs obtained from the Deja Vu database. Results The approach accurately detects duplicate Medline document pairs with an F1 measure score of 0.99. Allowing for word deletions and substitution improves performance. The best results are obtained by combining scores for n-grams of length 1–5 words. Discussion Results show that the detection of duplicate Medline citations can be improved by modifying n-grams and that high performance can also be obtained using only unigrams (F1=0.959), particularly when allowing for substitutions of alternative phrases. PMID:23715801

Gram-positive and gram-negative bacteria induce different patterns of cytokine production in human mononuclear cells irrespective of taxonomic relatedness.

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Skovbjerg, Susann; Martner, Anna; Hynsjö, Lars; Hessle, Christina; Olsen, Ingar; Dewhirst, Floyd E; Tham, Wilhelm; Wold, Agnes E

2010-01-01

Upon bacterial stimulation, tissue macrophages produce a variety of cytokines that orchestrate the immune response that clears the infection. We have shown that Gram-positives induce higher levels of interleukin-12 (IL-12), interferon-gamma (IFN-gamma), and tumor necrosis factor (TNF) from human peripheral blood mononuclear cells (PBMCs) than do Gram-negatives, which instead induce more of IL-6, IL-8, and IL-10. Here, we study whether these patterns follows or crosses taxonomic borders. PBMCs from blood donors were incubated with UV-inactivated bacteria representing 37 species from five phyla. IL-12, TNF, IL-1beta, IL-6, IL-8, and IL-10 were measured in the supernatants after 24 h and IFN-gamma after 5 days. Irrespective of phylogenetic position, Gram-positive bacteria induced much more IL-12 (nine times more on average) and IFN-gamma (seven times), more TNF (three times), and slightly more IL-1beta (1.5 times) than did Gram-negatives, which instead induced more IL-6 (1.5 times), IL-8 (1.9 times), and IL-10 (3.3 times) than did Gram-positives. A notable exception was the Gram-positive Listeria monocytogenes, which induced very little IL-12, IFN-gamma, and TNF. The results confirm the fundamental difference in innate immune responses to Gram-positive and Gram-negative bacteria, which crosses taxonomic borders and probably reflects differences in cell wall structure.

Transformation of gram positive bacteria by sonoporation

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Yang, Yunfeng; Li, Yongchao

2014-03-11

The present invention provides a sonoporation-based method that can be universally applied for delivery of compounds into Gram positive bacteria. Gram positive bacteria which can be transformed by sonoporation include, for example, Bacillus, Streptococcus, Acetobacterium, and Clostridium. Compounds which can be delivered into Gram positive bacteria via sonoporation include nucleic acids (DNA or RNA), proteins, lipids, carbohydrates, viruses, small organic and inorganic molecules, and nano-particles.

Bioengineered nisin A derivatives with enhanced activity against both Gram positive and Gram negative pathogens.

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Des Field

Full Text Available Nisin is a bacteriocin widely utilized in more than 50 countries as a safe and natural antibacterial food preservative. It is the most extensively studied bacteriocin, having undergone decades of bioengineering with a view to improving function and physicochemical properties. The discovery of novel nisin variants with enhanced activity against clinical and foodborne pathogens has recently been described. We screened a randomized bank of nisin A producers and identified a variant with a serine to glycine change at position 29 (S29G, with enhanced efficacy against S. aureus SA113. Using a site-saturation mutagenesis approach we generated three more derivatives (S29A, S29D and S29E with enhanced activity against a range of Gram positive drug resistant clinical, veterinary and food pathogens. In addition, a number of the nisin S29 derivatives displayed superior antimicrobial activity to nisin A when assessed against a range of Gram negative food-associated pathogens, including E. coli, Salmonella enterica serovar Typhimurium and Cronobacter sakazakii. This is the first report of derivatives of nisin, or indeed any lantibiotic, with enhanced antimicrobial activity against both Gram positive and Gram negative bacteria.

Bioengineered Nisin A Derivatives with Enhanced Activity against Both Gram Positive and Gram Negative Pathogens

Science.gov (United States)

Field, Des; Begley, Maire; O’Connor, Paula M.; Daly, Karen M.; Hugenholtz, Floor; Cotter, Paul D.; Hill, Colin; Ross, R. Paul

2012-01-01

Nisin is a bacteriocin widely utilized in more than 50 countries as a safe and natural antibacterial food preservative. It is the most extensively studied bacteriocin, having undergone decades of bioengineering with a view to improving function and physicochemical properties. The discovery of novel nisin variants with enhanced activity against clinical and foodborne pathogens has recently been described. We screened a randomized bank of nisin A producers and identified a variant with a serine to glycine change at position 29 (S29G), with enhanced efficacy against S. aureus SA113. Using a site-saturation mutagenesis approach we generated three more derivatives (S29A, S29D and S29E) with enhanced activity against a range of Gram positive drug resistant clinical, veterinary and food pathogens. In addition, a number of the nisin S29 derivatives displayed superior antimicrobial activity to nisin A when assessed against a range of Gram negative food-associated pathogens, including E. coli, Salmonella enterica serovar Typhimurium and Cronobacter sakazakii. This is the first report of derivatives of nisin, or indeed any lantibiotic, with enhanced antimicrobial activity against both Gram positive and Gram negative bacteria. PMID:23056510

PREVALENCIA DE BACTERIAS ASOCIADAS A LA INFERTILIDAD INFECCIOSA EN BOVINOS DE MONTERÍA, COLOMBIA

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Marco González T

2007-12-01

Full Text Available Objetivo. Establecer la prevalencia de algunos gérmenes asociados con infertilidad infecciosa de bovinos del municipio de Montería. Materiales y métodos. Se recolectaron 384 muestras sanguíneas e igual número de hisopados cervicales de hembras que cumplieron con alguno de los siguientes criterios de inclusión: más de tres servicios sin concepción, vaginitis, cervicitis, metritis, endometritis, útero con contenido, momificación fetal, natimortos, reabsorciones embrionarias, antecedentes de abortos y/o hembras positivas a brucelosis. Las muestras cervicales se sembraron en agar Mc conkey, agar sangre, agar brucella y agar campylobacter. A las colonias sospechosas se le realizaron pruebas bioquímicas y la confirmación se llevó a cabo con pruebas serológicas. Para el serodiagnóstico de Brucella, los sueros fueron analizados por Rosa de Bengala y los positivos fueron confirmados con ELISA indirecta. Resultados. De las 384 muestras procesadas, hubo crecimiento en 281 (73,2%, las bacterias prevalentes fueron Escherichia coli, Bacilos Gram Negativos Oxidantes, Klepsiella spp y Pseudomonas spp, que correspondieron a 194 (69.1% aislamientos y cinco muestras equivalentes al 1.8% resultaron positivas para Campylobacter spp. Las pruebas serológicas para Brucella arrojaron como resultado 22 muestras positivas por ELISA (6.3%. Conclusiones. Los resultados de este trabajo describen de forma preliminar la posible asociación bacteriana en la infertilidad infecciosa en hembras vacunas, demostrando la presencia de una gran variedad de microorganismos.

Low-fat papadams from black gram-tapioca blends.

Science.gov (United States)

Annapure, U S; Michael, M; Singhal, R S; Kulkarni, P R

1997-07-01

Papadams, made from black gram (Phaseolus mungo) and largely manufactured on cottage scale are popular in the Indian dietary. Escalating prices of black gram coupled with abundant availability of tapioca flour at almost 1/8th the price of black gram prompted the study of papadam characteristics using blends of black gram and tapioca flour. Tapioca flour up to 25% substitution did not alter the sensory attributes. However, the expansibility of the product decreased on addition of tapioca flour; a fact which could be overcome by using carboxymethyl cellulose (CMC) at 3% level of black gram flour. This decreased the oil content to 19.7% and also increased the expansibility to 5.539%.

Impacto de las redes sociales e internet en la adolescencia: aspectos positivos y negativos

OpenAIRE

L. Elías Arab, Dr.; G. Alejandra Díaz, Ps.

2015-01-01

Este artículo presenta una revisión teórica del impacto, tanto positivo como negativo, de las redes sociales en los adoles- centes y de la relación directa entre esto y el uso o abuso de las nuevas tecnologías. A su vez, se establece el vínculo entre las formas de utilizarlas y las características psicológi- cas individuales, los desarrollos previos de personalidad y el control parental. Se toma como punto de partida el desa- rrollo adolescente asociado a la construcción de la identidad juven...

Type I and Type II mechanisms of antimicrobial photodynamic therapy: an in vitro study on gram-negative and gram-positive bacteria.

Science.gov (United States)

Huang, Liyi; Xuan, Yi; Koide, Yuichiro; Zhiyentayev, Timur; Tanaka, Masamitsu; Hamblin, Michael R

2012-08-01

Antimicrobial photodynamic therapy (APDT) employs a non-toxic photosensitizer (PS) and visible light, which in the presence of oxygen produce reactive oxygen species (ROS), such as singlet oxygen ((1) O(2), produced via Type II mechanism) and hydroxyl radical (HO(.), produced via Type I mechanism). This study examined the relative contributions of (1) O(2) and HO(.) to APDT killing of Gram-positive and Gram-negative bacteria. Fluorescence probes, 3'-(p-hydroxyphenyl)-fluorescein (HPF) and singlet oxygen sensor green reagent (SOSG) were used to determine HO(.) and (1) O(2) produced by illumination of two PS: tris-cationic-buckminsterfullerene (BB6) and a conjugate between polyethylenimine and chlorin(e6) (PEI-ce6). Dimethylthiourea is a HO(.) scavenger, while sodium azide (NaN(3)) is a quencher of (1) O(2). Both APDT and killing by Fenton reaction (chemical generation of HO(.)) were carried out on Gram-positive bacteria (Staphylococcus aureus and Enterococcus faecalis) and Gram-negative bacteria (Escherichia coli, Proteus mirabilis, and Pseudomonas aeruginosa). Conjugate PEI-ce6 mainly produced (1) O(2) (quenched by NaN(3)), while BB6 produced HO(.) in addition to (1) O(2) when NaN(3) potentiated probe activation. NaN(3) also potentiated HPF activation by Fenton reagent. All bacteria were killed by Fenton reagent but Gram-positive bacteria needed a higher concentration than Gram-negatives. NaN(3) potentiated Fenton-mediated killing of all bacteria. The ratio of APDT killing between Gram-positive and Gram-negative bacteria was 2 or 4:1 for BB6 and 25:1 for conjugate PEI-ce6. There was a NaN(3) dose-dependent inhibition of APDT killing using both PEI-ce6 and BB6 against Gram-negative bacteria while NaN(3) almost failed to inhibit killing of Gram-positive bacteria. Azidyl radicals may be formed from NaN(3) and HO(.). It may be that Gram-negative bacteria are more susceptible to HO(.) while Gram-positive bacteria are more susceptible to (1) O(2). The differences in Na

Identificação de bactérias não fermentadoras isoladas de pacientes com fibrose cística e em hemoculturas de pacientes internados no HC da Unicamp

OpenAIRE

Élio Barreto de Carvalho Filho

2015-01-01

Resumo: Introdução: Bacilos gram-negativos não fermentadores (BGN-NFs) são microrganismos que se caracterizam pela incapacidade de utilizar a glicose como fonte de energia pela fermentação, degradando-a pela via oxidativa. A identificação dos BGN-NFs continua sendo um desafio para os laboratórios de rotina em microbiologia pela dificuldade de identificação, em virtude, da baixa ocorrência em amostras ambulatoriais, assim como, pela falta de recursos rápidos, eficientes e pela complexidade e ...

Gram-negative diabetic foot osteomyelitis: risk factors and clinical presentation.

Science.gov (United States)

Aragón-Sánchez, Javier; Lipsky, Benjamin A; Lázaro-Martínez, Jose L

2013-03-01

Osteomyelitis frequently complicates infections in the feet of patients with diabetes. Gram-positive cocci, especially Staphylococcus aureus, are the most commonly isolated pathogens, but gram-negative bacteria also cause some cases of diabetic foot osteomyelitis (DFO). These gram-negatives require different antibiotic regimens than those commonly directed at gram-positives. There are, however, few data on factors related to their presence and how they influence the clinical picture. We conducted a retrospective study to determine the variables associated with the isolation of gram-negative bacteria from bone samples in cases of DFO and the clinical presentation of these infections. Among 341 cases of DFO, 150 had a gram-negative isolate (alone or combined with a gram-positive isolate) comprising 44.0% of all patients and 50.8% of those with a positive bone culture. Compared with gram-positive infections, wounds with gram-negative organisms more often had a fetid odor, necrotic tissue, signs of soft tissue infection accompanying osteomyelitis, and clinically severe infection. By multivariate analysis, the predictive variables related to an increased likelihood of isolating gram-negatives from bone samples were glycated hemoglobin gram-negatives had a statistically significantly higher prevalence of leukocytosis and higher white blood cell counts than those without gram-negatives. In conclusion, gram-negative organisms were isolated in nearly half of our cases of DFO and were associated with more severe infections, higher white blood cell counts, lower glycated hemoglobin levels, and wounds of traumatic etiology.

Glycosaminoglycans are involved in pathogen adherence to corneal epithelial cells differently for Gram-positive and Gram-negative bacteria

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Beatriz García

2016-11-01

Full Text Available The epithelium of the cornea is continuously exposed to pathogens, and adhesion to epithelial cells is regarded as an essential first step in bacterial pathogenesis. In this article, the involvement of glycosaminoglycans in the adhesion of various pathogenic bacteria to corneal epithelial cells is analyzed. All microorganisms use glycosaminoglycans as receptors, but arranged in different patterns depending on the Gram-type of the bacterium. The heparan sulfate chains of syndecans are the main receptors, though other molecular species also seem to be involved, particularly in Gram-negative bacteria. Adherence is inhibited differentially by peptides, including heparin binding sequences, indicating the participation of various groups of Gram-positive and -negative adhesins. The length of the saccharides produces a major effect, and low molecular weight chains inhibit the binding of Gram-negative microorganisms but increase the adherence of Gram-positives. Pathogen adhesion appears to occur preferentially through sulfated domains, and is very dependent on N- and 6-O-sulfation of the glucosamine residue and, to a lesser extent, 2-O sulfation of uronic acid. These data show the differential use of corneal receptors, which could facilitate the development of new anti-infective strategies.

A new technique for Gram staining paraffin-embedded tissue.

Science.gov (United States)

Engbaek, K; Johansen, K S; Jensen, M E

1979-01-01

Five techniques for Gram staining bacteria in paraffin sections were compared on serial sections of pulmonary tissues from eight bacteriological necropsies. Brown and Hopp's method was the most satisfactory for distinguishing Gram-positive and Gram-negative bacteria. However, this method cannot be recommended as the preparations were frequently overstained, and the Gram-negative bacteria were stained indistinctly. A modification of Brown and Hopps' method was developed which stains larger numbers of Gram-negative bacteria and differentiates well between different cell types and connective tissue, and there is no risk of overstaining. PMID:86548

Alternate gram staining technique using a fluorescent lectin.

Science.gov (United States)

Sizemore, R K; Caldwell, J J; Kendrick, A S

1990-01-01

Fluorescence-labeled wheat germ agglutinin binds specifically to N-acetylglucosamine in the outer peptidoglycan layer of gram-positive bacteria. The peptidoglycan layer of gram-negative bacteria is covered by a membrane and is not labeled by the lectin. By exploiting this phenomenon, an alternative Gram staining technique has been developed. Images PMID:1697149

Microbiota bacteriana da conjuntiva de doadores de córnea Bacterial microbiota of the conjunctiva of donor corneas

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Maria Emília Xavier dos Santos Araújo

2004-12-01

Full Text Available OBJETIVOS: Quantificar e qualificar a microbiota aeróbia da conjuntiva de doadores de córnea segundo a interferência do intervalo de tempo entre o óbito e a colheita do espécime conjuntival, a causa do óbito e a idade do doador e avaliar a atividade biocida de determinados antibióticos aos microrganismos isolados. MÉTODOS: Entre janeiro e março de 1994 foram colhidos espécimes da conjuntiva de 242 olhos de doadores de córnea. O material transportado em meio de Stuart foi semeado em ágares sangue, chocolate, sangue azida, MacConkey e caldo tioglicolato. Foi registrada a idade do doador, hora e causa do óbito. A atividade biocida dos antibióticos foi avaliada pela metodologia de Kirby e Bauer. A análise estatística utilizou os testes do qui-quadrado, exato de Fisher e Mann-Whitney. RESULTADOS: A freqüência de cultura positiva da conjuntiva de doadores de córnea foi de 91,7%. A mediana da idade dos doadores foi de 62 anos e do intervalo de tempo entre o óbito e a colheita do espécime foi de 4,2 horas. A causa mais freqüente de óbito foi doença cardiovascular (26,4%. Não houve diferença significante entre a cultura positiva e as variáveis estudadas. A vancomicina inibiu 100% das cepas de bactérias Gram-positivas e a sensibilidade dos bacilos Gram-negativos à gentamicina variou de 36,7% a 92,3%. CONCLUSÕES: O estudo revelou freqüência elevada de cultura positiva da conjuntiva de doadores de córneas. Staphylococcus coagulase negativo foi a espécie com maior número de isolamentos positivos. Não foi encontrada associação entre os fatores de risco avaliados e cultura positiva. Os antibióticos tiveram atividade biocida variável sobre os Gram-negativos e 100% dos Gram-positivos foram sensíveis à vancomicina.PURPOSE: To identify and qualify bacterial organisms in conjunctival tissue of donor corneas. To correlate the frequency of positive cultures with donor age, cause of death, and time from death to collection of

Veillonella, Firmicutes: Microbes disguised as Gram negatives.

Science.gov (United States)

Vesth, Tammi; Ozen, Aslı; Andersen, Sandra C; Kaas, Rolf Sommer; Lukjancenko, Oksana; Bohlin, Jon; Nookaew, Intawat; Wassenaar, Trudy M; Ussery, David W

2013-12-20

The Firmicutes represent a major component of the intestinal microflora. The intestinal Firmicutes are a large, diverse group of organisms, many of which are poorly characterized due to their anaerobic growth requirements. Although most Firmicutes are Gram positive, members of the class Negativicutes, including the genus Veillonella, stain Gram negative. Veillonella are among the most abundant organisms of the oral and intestinal microflora of animals and humans, in spite of being strict anaerobes. In this work, the genomes of 24 Negativicutes, including eight Veillonella spp., are compared to 20 other Firmicutes genomes; a further 101 prokaryotic genomes were included, covering 26 phyla. Thus a total of 145 prokaryotic genomes were analyzed by various methods to investigate the apparent conflict of the Veillonella Gram stain and their taxonomic position within the Firmicutes. Comparison of the genome sequences confirms that the Negativicutes are distantly related to Clostridium spp., based on 16S rRNA, complete genomic DNA sequences, and a consensus tree based on conserved proteins. The genus Veillonella is relatively homogeneous: inter-genus pair-wise comparison identifies at least 1,350 shared proteins, although less than half of these are found in any given Clostridium genome. Only 27 proteins are found conserved in all analyzed prokaryote genomes. Veillonella has distinct metabolic properties, and significant similarities to genomes of Proteobacteria are not detected, with the exception of a shared LPS biosynthesis pathway. The clade within the class Negativicutes to which the genus Veillonella belongs exhibits unique properties, most of which are in common with Gram-positives and some with Gram negatives. They are only distantly related to Clostridia, but are even less closely related to Gram-negative species. Though the Negativicutes stain Gram-negative and possess two membranes, the genome and proteome analysis presented here confirm their place within the

Gram staining with an automatic machine.

Science.gov (United States)

Felek, S; Arslan, A

1999-01-01

This study was undertaken to develop a new Gram-staining machine controlled by a micro-controller and to investigate the quality of slides that were stained in the machine. The machine was designed and produced by the authors. It uses standard 220 V AC. Staining, washing, and drying periods are controlled by a timer built in the micro-controller. A software was made that contains a certain algorithm and time intervals for the staining mode. One-hundred and forty smears were prepared from Escherichia coli, Staphylococcus aureus, Neisseria sp., blood culture, trypticase soy broth, direct pus and sputum smears for comparison studies. Half of the slides in each group were stained with the machine, the other half by hand and then examined by four different microbiologists. Machine-stained slides had a higher clarity and less debris than the hand-stained slides (p stained slides, some Gram-positive organisms showed poor Gram-positive staining features (p Gram staining with the automatic machine increases the staining quality and helps to decrease the work load in a busy diagnostic laboratory.

Antimicrobial activity of metal oxide nanoparticles against Gram-positive and Gram-negative bacteria: a comparative study

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Azam A

2012-12-01

Full Text Available Ameer Azam,1,2 Arham S Ahmed,2 Mohammad Oves,3 Mohammad S Khan,3 Sami S Habib,1 Adnan Memic11Centre of Nanotechnology, King Abdulaziz University, Jeddah, Saudi Arabia; 2Centre of Excellence in Materials Science (Nanomaterials, 3Department of Agricultural Microbiology, Aligarh Muslim University, Aligarh, IndiaBackground: Nanomaterials have unique properties compared to their bulk counterparts. For this reason, nanotechnology has attracted a great deal of attention from the scientific community. Metal oxide nanomaterials like ZnO and CuO have been used industrially for several purposes, including cosmetics, paints, plastics, and textiles. A common feature that these nanoparticles exhibit is their antimicrobial behavior against pathogenic bacteria. In this report, we demonstrate the antimicrobial activity of ZnO, CuO, and Fe2O3 nanoparticles against Gram-positive and Gram-negative bacteria.Methods and results: Nanosized particles of three metal oxides (ZnO, CuO, and Fe2O3 were synthesized by a sol–gel combustion route and characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, and transmission electron microscopy techniques. X-ray diffraction results confirmed the single-phase formation of all three nanomaterials. The particle sizes were observed to be 18, 22, and 28 nm for ZnO, CuO, and Fe2O3, respectively. We used these nanomaterials to evaluate their antibacterial activity against both Gram-negative (Escherichia coli and Pseudomonas aeruginosa and Gram-positive (Staphylococcus aureus and Bacillus subtilis bacteria.Conclusion: Among the three metal oxide nanomaterials, ZnO showed greatest antimicrobial activity against both Gram-positive and Gram-negative bacteria used in this study. It was observed that ZnO nanoparticles have excellent bactericidal potential, while Fe2O3 nanoparticles exhibited the least bactericidal activity. The order of antibacterial activity was demonstrated to be the following: ZnO > CuO > Fe2O3

Fibrosis pulmonar asociada a vasculitis con anticuerpos anticitoplasmáticos positivos

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Marcelo Fernández Casares

2012-08-01

Full Text Available Las complicaciones pulmonares más conocidas de las vasculitis con anticuerpos anticitoplasmáticos de los neutrófilos (ANCA positivos (VAA, son la hemorragia alveolar, los granulomas y la estenosis de la vía aérea. En los últimos años han aparecido algunos informes aislados que muestran la asociación con fibrosis pulmonar (FP, sugiriendo que ésta sería otra complicación de las VAA. En este trabajo informamos dos casos con dicha asociación describiendo sus características clínicas, tomográficas e inmunológicas. Dado que en la asociación de FP y VAA notificada en los últimos años, la FP puede ser su primera manifestación, podría ser necesaria la búsqueda de ANCA en pacientes con FP, como causa de la misma y por el posible desarrollo posterior de vasculitis.

Mechanistic antimicrobial approach of extracellularly synthesized silver nanoparticles against gram positive and gram negative bacteria

Energy Technology Data Exchange (ETDEWEB)

Tamboli, Dhawal P.; Lee, Dae Sung, E-mail: daesung@knu.ac.kr

2013-09-15

Highlights: • Bacterial extracelluar enzymes stabilized the silver nanoparticles (AgNPs). • AgNPs formation was characterized by analytical techniques such as UV–vis, TEM, and FTIR. • AgNPs showed obvious antimicrobial activity against both gram positive and gram negative microorganisms. • A mechanism of AgNPs’ antimicrobial activity was proposed. -- Abstract: The development of eco-friendly and reliable processes for the synthesis of nanoparticles has attracted considerable interest in nanotechnology. In this study, an extracellular enzyme system of a newly isolated microorganism, Exiguobacterium sp. KNU1, was used for the reduction of AgNO{sub 3} solutions to silver nanoparticles (AgNPs). The extracellularly biosynthesized AgNPs were characterized by UV–vis spectroscopy, Fourier transform infra-red spectroscopy and transmission electron microscopy. The AgNPs were approximately 30 nm (range 5–50 nm) in size, well-dispersed and spherical. The AgNPs were evaluated for their antimicrobial effects on different gram negative and gram positive bacteria using the minimum inhibitory concentration method. Reasonable antimicrobial activity against Salmonella typhimurium, Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus was observed. The morphological changes occurred in all the microorganisms tested. In particular, E. coli exhibited DNA fragmentation after being treated with the AgNPs. Finally, the mechanism for their bactericidal activity was proposed according to the results of scanning electron microscopy and single cell gel electrophoresis.

Mechanistic antimicrobial approach of extracellularly synthesized silver nanoparticles against gram positive and gram negative bacteria

International Nuclear Information System (INIS)

Tamboli, Dhawal P.; Lee, Dae Sung

2013-01-01

Highlights: • Bacterial extracelluar enzymes stabilized the silver nanoparticles (AgNPs). • AgNPs formation was characterized by analytical techniques such as UV–vis, TEM, and FTIR. • AgNPs showed obvious antimicrobial activity against both gram positive and gram negative microorganisms. • A mechanism of AgNPs’ antimicrobial activity was proposed. -- Abstract: The development of eco-friendly and reliable processes for the synthesis of nanoparticles has attracted considerable interest in nanotechnology. In this study, an extracellular enzyme system of a newly isolated microorganism, Exiguobacterium sp. KNU1, was used for the reduction of AgNO 3 solutions to silver nanoparticles (AgNPs). The extracellularly biosynthesized AgNPs were characterized by UV–vis spectroscopy, Fourier transform infra-red spectroscopy and transmission electron microscopy. The AgNPs were approximately 30 nm (range 5–50 nm) in size, well-dispersed and spherical. The AgNPs were evaluated for their antimicrobial effects on different gram negative and gram positive bacteria using the minimum inhibitory concentration method. Reasonable antimicrobial activity against Salmonella typhimurium, Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus was observed. The morphological changes occurred in all the microorganisms tested. In particular, E. coli exhibited DNA fragmentation after being treated with the AgNPs. Finally, the mechanism for their bactericidal activity was proposed according to the results of scanning electron microscopy and single cell gel electrophoresis

Techniques for controlling variability in gram staining of obligate anaerobes.

Science.gov (United States)

Johnson, M J; Thatcher, E; Cox, M E

1995-01-01

Identification of anaerobes recovered from clinical samples is complicated by the fact that certain gram-positive anaerobes routinely stain gram negative; Peptostreptococcus asaccharolyticus, Eubacterium plautii, Clostridium ramosum, Clostridium symbiosum, and Clostridium clostridiiforme are among the nonconformists with regard to conventional Gram-staining procedures. Accurate Gram staining of American Type Culture Collection strains of these anaerobic bacteria is possible by implementing fixing and staining techniques within a gloveless anaerobic chamber. Under anaerobic conditions, gram-positive staining occurred in all test organisms with "quick" fixing techniques with both absolute methanol and formalin. The results support the hypothesis that, when anaerobic bacteria are exposed to oxygen, a breakdown of the physical integrity of the cell wall occurs, introducing Gram stain variability in gram-positive anaerobes. PMID:7538512

Suetônio, dos gramáticos

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Marcos Martinho

2014-12-01

Full Text Available O Dos gramáticos de Suetônio divide-se em duas partes: na primeira, o autor narra a introdução, desenvolvimento, florescimento e declínio da gramática em Roma (1-4; na segunda, expõe a biografia de vinte professores de gramática, que ensinaram na Cidade entre o início do séc.  I a.C. e meados do século seguinte (5-24. Quanto à primeira parte, procuro mostrar que Suetônio adota conceitos fisicistas ou naturalistas para narrar a história da gramática em Roma, de modo que aquela se possa comparar à vida de um ser vivo. Assim, a exposição de Suetônio revela-se, na verdade, antes biográfica que historicista. Quanto à segunda parte, procuro mostrar que o Biógrafo se interessa por gramáticos que não só escreveram sobre sua arte no ócio, mas a ensinaram por ofício, isto é, por professores de gramática. Daí, seleciono e comento os elementos narrativos relacionados à docência, a saber: os métodos de ensino, o lugar de ensino, o número e qualidade dos alunos, os preços e honorários dos professores. Por fim, apresento tradução anotada do texto de Suetônio.

Enfoques positivos y normativos en las políticas de ciencia y tecnología

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Morera Cuesta, Rafael

2009-08-01

Full Text Available The aim of this paper is to show how normative approaches to scientific research and technological development (R&D policies have shaped positive analysis. It presents a general overview of those contributions from decision makers and researchers to the early debates that founded social studies of research and development in mid 40s. Moreover, this article uses the distinction between positive and normative approaches to hold that international organizations, especially OECD, held the leadership in the normative construction of R&D discourses, and that subsequent positive analyses have been conducted in academia following normative guidelines. This applies for both national and international academic circles.Este artículo presenta una visión general de la evolución de los trabajos que estudian las políticas públicas de investigación científica y desarrollo tecnológico (I+D, desde la apertura de este campo a la acción del gobierno en la década de 1940 hasta la actualidad. Tras hacer un repaso descriptivo de cuáles fueron las primeras aportaciones de los decisores públicos y de los académicos a este campo de conocimiento durante su proceso de creación, este trabajo utiliza la distinción entre enfoques positivos y normativos y defiende que el liderazgo normativo ha correspondido a los organismos internacionales, especialmente a la OCDE, y que los enfoques positivos en la literatura académica internacional y en la nacional han evolucionado siguiendo las pautas marcadas por esta institución.

Gramática Hipertextual

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Francilaine Munhoz Moraes

2011-07-01

Full Text Available No meio digital, a construção da notícia se dá pelo hipertexto. Uma linguagem própria ao suporte consolida-se nas duas últimas décadas. Este artigo se dedica a discutir regularidades linguísticas do discurso jornalístico na web. Se há uma linguagem peculiar ao meio, existe também uma gramática correspondente: a gramática hipertextual. Nesse viés, levantamos traços linguísticos da estrutura sintático-semântica, com base na organização da informação em páginas noticiosas eletrônicas. 

Protein classification using modified n-grams and skip-grams.

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Islam, S M Ashiqul; Heil, Benjamin J; Kearney, Christopher Michel; Baker, Erich J

2018-05-01

Classification by supervised machine learning greatly facilitates the annotation of protein characteristics from their primary sequence. However, the feature generation step in this process requires detailed knowledge of attributes used to classify the proteins. Lack of this knowledge risks the selection of irrelevant features, resulting in a faulty model. In this study, we introduce a supervised protein classification method with a novel means of automating the work-intensive feature generation step via a Natural Language Processing (NLP)-dependent model, using a modified combination of n-grams and skip-grams (m-NGSG). A meta-comparison of cross-validation accuracy with twelve training datasets from nine different published studies demonstrates a consistent increase in accuracy of m-NGSG when compared to contemporary classification and feature generation models. We expect this model to accelerate the classification of proteins from primary sequence data and increase the accessibility of protein characteristic prediction to a broader range of scientists. m-NGSG is freely available at Bitbucket: https://bitbucket.org/sm_islam/mngsg/src. A web server is available at watson.ecs.baylor.edu/ngsg. erich_baker@baylor.edu. Supplementary data are available at Bioinformatics online.

Simultaneous fluorescent gram staining and activity assessment of activated sludge bacteria.

Science.gov (United States)

Forster, Scott; Snape, Jason R; Lappin-Scott, Hilary M; Porter, Jonathan

2002-10-01

Wastewater treatment is one of the most important commercial biotechnological processes, and yet the component bacterial populations and their associated metabolic activities are poorly understood. The novel fluorescent dye hexidium iodide allows assessment of Gram status by differential absorption through bacterial cell walls. Differentiation between gram-positive and gram-negative wastewater bacteria was achieved after flow cytometric analysis. This study shows that the relative proportions of gram-positive and gram-negative bacterial cells identified by traditional microscopy and hexidium iodide staining were not significantly different. Dual staining of cells for Gram status and activity proved effective in analyzing mixtures of cultured bacteria and wastewater populations. Levels of highly active organisms at two wastewater treatment plants, both gram positive and gram negative, ranged from 1.5% in activated sludge flocs to 16% in the activated sludge fluid. Gram-positive organisms comprised Gram status and activity within activated sludge samples over a 4-day period showed significant differences over time. This method provides a rapid, quantitative measure of Gram status linked with in situ activity within wastewater systems.

Different Use of Cell Surface Glycosaminoglycans As Adherence Receptors to Corneal Cells by Gram Positive and Gram Negative Pathogens

Science.gov (United States)

García, Beatriz; Merayo-Lloves, Jesús; Rodríguez, David; Alcalde, Ignacio; García-Suárez, Olivia; Alfonso, José F.; Baamonde, Begoña; Fernández-Vega, Andrés; Vazquez, Fernando; Quirós, Luis M.

2016-01-01

The epithelium of the cornea is continuously exposed to pathogens, and adhesion to epithelial cells is regarded as an essential first step in bacterial pathogenesis. In this article, the involvement of glycosaminoglycans in the adhesion of various pathogenic bacteria to corneal epithelial cells is analyzed. All microorganisms use glycosaminoglycans as receptors, but arranged in different patterns depending on the Gram-type of the bacterium. The heparan sulfate chains of syndecans are the main receptors, though other molecular species also seem to be involved, particularly in Gram-negative bacteria. Adherence is inhibited differentially by peptides, including heparin binding sequences, indicating the participation of various groups of Gram-positive, and -negative adhesins. The length of the saccharides produces a major effect, and low molecular weight chains inhibit the binding of Gram-negative microorganisms but increase the adherence of Gram-positives. Pathogen adhesion appears to occur preferentially through sulfated domains, and is very dependent on N- and 6-O-sulfation of the glucosamine residue and, to a lesser extent, 2-O sulfation of uronic acid. These data show the differential use of corneal receptors, which could facilitate the development of new anti-infective strategies. PMID:27965938

Consorcios microbianos con actividad ácido-láctica promisoria aislados desde inoculantes bacterianos nativos para ensilajes

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Byron Leoncio Díaz-Monroy

2015-04-01

Full Text Available El objetivo de este trabajo fue aislar y caracterizar cepas de bacterias ácido lácticas (BAL a partir de preparados microbianos (PM nativos elaborados a base de residuos agroindustriales, como suero de leche, estiércol bovino y contenido ruminal, y diseñados como inoculantes biológicos para procesos de ensilaje de residuales orgánicos poscosecha. Se evaluaron 5 tratamientos (preparados microbianos, PM + 33% de residuo inoculante, con 3 réplicas: 1 Tratamiento control sin inoculante (PMSI, 2 Suero de leche (PMSL, 3 Estiércol bovino (PMEB, 4 Combinación de suero+estiércol (PMM y 5 Contenido ruminal (PMCR; además, en todos se adicionó: melaza (20%, urea (1%, sal mineral (1% y agua (45%. En recipientes plásticos se fermentaron tapados durante 96 horas, a 14 °C; de allí se obtuvieron 3 muestras de 500 mL de cada PM, se sembraron en agar MRS (Man, Rogosa y Sharpe y se incubaron a 37 ºC durante 72 h bajo condiciones anaerobias (AnaeroGen, Oxoid. Las cepas de BAL son catalasa y oxidasa negativas, cocos, coco-bacilos y bacilos Gram positivos no esporulados. La identificación bioquímica se realizó con el sistema API-50CHL (BioMérieux, France y la base de datos APILAB Plus versión 3.3.3. Se aislaron 39 cepas de BAL, 4 del PMSI (2 Lactobacillus plantarum, 1 L. brevis y 1 Lactococcus lactis, 12 del PMSL (3 Lactobacillus rhamnosus, 3 L. casei, 2 L. acidophilus, 2 L. paracasei y 2 L. fermentum, 7 del PMEB (3 Streptococcus bovis, 2 Lactobacillus plantarum y 2 Leuconostoc mesenteroides, 10 del PMM (3 Lactobacillus casei, 2 L. plantarum, 2 L. acidophilus, 1 L. fermentum, 1 L. rhamnosus y 1 L. paracasei y 6 del PMCR (2 Lactobacillus vitulinus, 2 L. ruminus, 1 L. reuteri y 1 Pediococcus damnosus. En conclusión, la mejor fuente de cepas de BAL fue PMSL, que le otorga ventajas como posible inoculante bacteriano para ensilajes. En todos los PM se identificaron cepas homofermentativas y heterofermentativas, asociadas en consorcios

Pleural effusion adenosine deaminase: a candidate biomarker to discriminate between Gram-negative and Gram-positive bacterial infections of the pleural space

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Ruolin Li

2016-05-01

Full Text Available OBJECTIVES: Delay in the treatment of pleural infection may contribute to its high mortality. In this retrospective study, we aimed to evaluate the diagnostic accuracy of pleural adenosine deaminase in discrimination between Gram-negative and Gram-positive bacterial infections of the pleural space prior to selecting antibiotics. METHODS: A total of 76 patients were enrolled and grouped into subgroups according to Gram staining: 1 patients with Gram-negative bacterial infections, aged 53.2±18.6 years old, of whom 44.7% had empyemas and 2 patients with Gram-positive bacterial infections, aged 53.5±21.5 years old, of whom 63.1% had empyemas. The pleural effusion was sampled by thoracocentesis and then sent for adenosine deaminase testing, biochemical testing and microbiological culture. The Mann-Whitney U test was used to examine the differences in adenosine deaminase levels between the groups. Correlations between adenosine deaminase and specified variables were also quantified using Spearman’s correlation coefficient. Moreover, receiver operator characteristic analysis was performed to evaluate the diagnostic accuracy of pleural effusion adenosine deaminase. RESULTS: Mean pleural adenosine deaminase levels differed significantly between Gram-negative and Gram-positive bacterial infections of the pleural space (191.8±32.1 U/L vs 81.0±16.9 U/L, p<0.01. The area under the receiver operator characteristic curve was 0.689 (95% confidence interval: 0.570, 0.792, p<0.01 at the cutoff value of 86 U/L. Additionally, pleural adenosine deaminase had a sensitivity of 63.2% (46.0-78.2%; a specificity of 73.7% (56.9-86.6%; positive and negative likelihood ratios of 2.18 and 0.50, respectively; and positive and negative predictive values of 70.6% and 66.7%, respectively. CONCLUSIONS: Pleural effusion adenosine deaminase is a helpful alternative biomarker for early and quick discrimination of Gram-negative from Gram-positive bacterial infections of the

Orbit Classification of Qutrit via the Gram Matrix

International Nuclear Information System (INIS)

Tay, B. A.; Zainuddin, Hishamuddin

2008-01-01

We classify the orbits generated by unitary transformation on the density matrices of the three-state quantum systems (qutrits) via the Gram matrix. The Gram matrix is a real symmetric matrix formed from the Hilbert–Schmidt scalar products of the vectors lying in the tangent space to the orbits. The rank of the Gram matrix determines the dimensions of the orbits, which fall into three classes for qutrits. (general)

[Usefulness of sputum Gram staining in community-acquired pneumonia].

Science.gov (United States)

Sato, Tadashi; Aoshima, Masahiro; Ohmagari, Norio; Tada, Hiroshi; Chohnabayashi, Naohiko

2002-07-01

To evaluate the usefulness of sputum gram staining in community-acquired pneumonia (CAP), we reviewed 144 cases requiring hospitalization in the last 4 years. The sensitivity was 75.5%, specificity 68.2%, positive predictive value 74.1%, negative predictive value 69.8%, positive likelihood ratio 2.37, negative likelihood ratio 0.36 and accuracy 72.2% in 97 cases. Both sputum gram staining and culture were performed. Concerning bacterial pneumonia (65 cases), we compared the Gram staining group (n = 33), which received initial antibiotic treatment, based on sputum gram staining with the Empiric group (n = 32) that received antibiotics empirically. The success rates of the initial antibiotic treatment were 87.9% vs. 78.1% (P = 0.473); mean hospitalization periods were 9.67 vs. 11.75 days (P = 0.053); and periods of intravenous therapy were 6.73 vs. 7.91 days (P = 0.044), respectively. As for initial treatment, penicillins were used in the Gram staining group more frequently (P gram staining is useful for the shortening of the treatment period and the appropriate selection of initial antibiotics in bacterial pneumonia. We believe, therefore, that sputum gram staining is indispensable as a diagnostic tool CAP.

Neither Single nor a Combination of Routine Laboratory Parameters can Discriminate between Gram-positive and Gram-negative Bacteremia

Science.gov (United States)

Ratzinger, Franz; Dedeyan, Michel; Rammerstorfer, Matthias; Perkmann, Thomas; Burgmann, Heinz; Makristathis, Athanasios; Dorffner, Georg; Loetsch, Felix; Blacky, Alexander; Ramharter, Michael

2015-01-01

Adequate early empiric antibiotic therapy is pivotal for the outcome of patients with bloodstream infections. In clinical practice the use of surrogate laboratory parameters is frequently proposed to predict underlying bacterial pathogens; however there is no clear evidence for this assumption. In this study, we investigated the discriminatory capacity of predictive models consisting of routinely available laboratory parameters to predict the presence of Gram-positive or Gram-negative bacteremia. Major machine learning algorithms were screened for their capacity to maximize the area under the receiver operating characteristic curve (ROC-AUC) for discriminating between Gram-positive and Gram-negative cases. Data from 23,765 patients with clinically suspected bacteremia were screened and 1,180 bacteremic patients were included in the study. A relative predominance of Gram-negative bacteremia (54.0%), which was more pronounced in females (59.1%), was observed. The final model achieved 0.675 ROC-AUC resulting in 44.57% sensitivity and 79.75% specificity. Various parameters presented a significant difference between both genders. In gender-specific models, the discriminatory potency was slightly improved. The results of this study do not support the use of surrogate laboratory parameters for predicting classes of causative pathogens. In this patient cohort, gender-specific differences in various laboratory parameters were observed, indicating differences in the host response between genders. PMID:26522966

Impacto de las redes sociales e internet en la adolescencia: aspectos positivos y negativos

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L. Elías Arab, Dr.

2015-01-01

Full Text Available Este artículo presenta una revisión teórica del impacto, tanto positivo como negativo, de las redes sociales en los adoles- centes y de la relación directa entre esto y el uso o abuso de las nuevas tecnologías. A su vez, se establece el vínculo entre las formas de utilizarlas y las características psicológi- cas individuales, los desarrollos previos de personalidad y el control parental. Se toma como punto de partida el desa- rrollo adolescente asociado a la construcción de la identidad juvenil en el contexto de un nuevo paradigma comunica- cional (cibercomunicación, donde el límite entre lo públi- co y lo privado se torna cada vez más difuso. Se expone la terminología propia de las redes sociales y se pone énfasis en las estrategias de supervisión y control adulto. Se deta- llan los aspectos positivos que las nuevas tecnologías ofre- cen (diversas oportunidades de aprendizaje, entretención, socialización, desarrollo de habilidades, creatividad y me- jora de la motivación al aprendizaje especialmente en ado- lescentes, entre otros y los aspectos negativos asociados (distanciamiento afectivo, pérdida de límites en la comuni- cación y pérdida de la capacidad de escucha, entre otros. Este artículo destaca la necesidad de entregar y estimular modelos de comunicación social reales y una educación en el uso de las nuevas tecnologías. El objetivo es actualizar y orientar a profesionales de la salud sobre los aspectos posi- tivos y/o negativos de las redes sociales en los adolescentes.

Drug-resistant gram-negative uropathogens: A review.

Science.gov (United States)

Khoshnood, Saeed; Heidary, Mohsen; Mirnejad, Reza; Bahramian, Aghil; Sedighi, Mansour; Mirzaei, Habibollah

2017-10-01

Urinary tract infection(UTI) caused by Gram-negative bacteria is the second most common infectious presentation in community medical practice. Approximately 150 million people are diagnosed with UTI each year worldwide. Drug resistance in Gram-negative uropathogens is a major global concern which can lead to poor clinical outcomes including treatment failure, development of bacteremia, requirement for intravenous therapy, hospitalization, and extended length of hospital stay. The mechanisms of drug resistance in these bacteria are important due to they are often not identified by routine susceptibility tests and have an exceptional potential for outbreaks. Treatment of UTIs depends on the access to effective drugs, which is now threatened by antibiotic resistant Gram-negative uropathogens. Although several effective antibiotics with activity against highly resistant Gram-negatives are available, there is not a unique antibiotic with activity against the high variety of resistance. Therefore, antimicrobial susceptibility tests, correlation between clinicians and laboratories, development of more rapid diagnostic methods, and continuous monitoring of drug resistance are urgent priorities. In this review, we will discuss about the current global status of drug-resistant Gram-negative uropathogens and their mechanisms of drug resistance to provide new insights into their treatment options. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Gram staining in the diagnosis of acute septic arthritis.

Science.gov (United States)

Faraj, A A; Omonbude, O D; Godwin, P

2002-10-01

This study aimed at determining the sensitivity and specificity of Gram staining of synovial fluid as a diagnostic tool in acute septic arthritis. A retrospective study was made of 22 patients who had arthroscopic lavage following a provisional diagnosis of acute septic arthritis of the knee joint. Gram stains and cultures of the knee aspirates were compared with the clinical and laboratory parameters, to evaluate their usefulness in diagnosing acute arthritis. All patients who had septic arthritis had pain, swelling and limitation of movement. CRP was elevated in 90% of patients. The incidence of elevated white blood cell count was higher in the group of patients with a positive Gram stain study (60%) as compared to patients with a negative Gram stain study (33%). Gram staining sensitivity was 45%. Its specificity was however 100%. Gram staining is an unreliable tool in early decision making in patients requiring urgent surgical drainage and washout.

Raman Spectroscopy of Xylitol Uptake and Metabolism in Gram-Positive and Gram-Negative Bacteria▿

Science.gov (United States)

Palchaudhuri, Sunil; Rehse, Steven J.; Hamasha, Khozima; Syed, Talha; Kurtovic, Eldar; Kurtovic, Emir; Stenger, James

2011-01-01

Visible-wavelength Raman spectroscopy was used to investigate the uptake and metabolism of the five-carbon sugar alcohol xylitol by Gram-positive viridans group streptococcus and the two extensively used strains of Gram-negative Escherichia coli, E. coli C and E. coli K-12. E. coli C, but not E. coli K-12, contains a complete xylitol operon, and the viridans group streptococcus contains an incomplete xylitol operon used to metabolize the xylitol. Raman spectra from xylitol-exposed viridans group streptococcus exhibited significant changes that persisted even in progeny grown from the xylitol-exposed mother cells in a xylitol-free medium for 24 h. This behavior was not observed in the E. coli K-12. In both viridans group streptococcus and the E. coli C derivative HF4714, the metabolic intermediates are stably formed to create an anomaly in bacterial normal survival. The uptake of xylitol by Gram-positive and Gram-negative pathogens occurs even in the presence of other high-calorie sugars, and its stable integration within the bacterial cell wall may discontinue bacterial multiplication. This could be a contributing factor for the known efficacy of xylitol when taken as a prophylactic measure to prevent or reduce occurrences of persistent infection. Specifically, these bacteria are causative agents for several important diseases of children such as pneumonia, otitis media, meningitis, and dental caries. If properly explored, such an inexpensive and harmless sugar-alcohol, alone or used in conjunction with fluoride, would pave the way to an alternative preventive therapy for these childhood diseases when the causative pathogens have become resistant to modern medicines such as antibiotics and vaccine immunotherapy. PMID:21037297

Stool Gram stain

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... stool sample. The Gram stain method is sometimes used to quickly diagnose bacterial infections. How the Test is Performed You will need to collect a stool sample. There are many ways to collect the sample. You can catch the stool on plastic wrap that is loosely placed over the toilet bowl ...

Prediction of lipoprotein signal peptides in Gram-negative bacteria.

Science.gov (United States)

Juncker, Agnieszka S; Willenbrock, Hanni; Von Heijne, Gunnar; Brunak, Søren; Nielsen, Henrik; Krogh, Anders

2003-08-01

A method to predict lipoprotein signal peptides in Gram-negative Eubacteria, LipoP, has been developed. The hidden Markov model (HMM) was able to distinguish between lipoproteins (SPaseII-cleaved proteins), SPaseI-cleaved proteins, cytoplasmic proteins, and transmembrane proteins. This predictor was able to predict 96.8% of the lipoproteins correctly with only 0.3% false positives in a set of SPaseI-cleaved, cytoplasmic, and transmembrane proteins. The results obtained were significantly better than those of previously developed methods. Even though Gram-positive lipoprotein signal peptides differ from Gram-negatives, the HMM was able to identify 92.9% of the lipoproteins included in a Gram-positive test set. A genome search was carried out for 12 Gram-negative genomes and one Gram-positive genome. The results for Escherichia coli K12 were compared with new experimental data, and the predictions by the HMM agree well with the experimentally verified lipoproteins. A neural network-based predictor was developed for comparison, and it gave very similar results. LipoP is available as a Web server at www.cbs.dtu.dk/services/LipoP/.

Selective bowel decontamination results in gram-positive translocation.

Science.gov (United States)

Jackson, R J; Smith, S D; Rowe, M I

1990-05-01

Colonization by enteric gram-negative bacteria with subsequent translocation is believed to be a major mechanism for infection in the critically ill patient. Selective bowel decontamination (SBD) has been used to control gram-negative infections by eliminating these potentially pathogenic bacteria while preserving anaerobic and other less pathogenic organisms. Infection with gram-positive organisms and anaerobes in two multivisceral transplant patients during SBD led us to investigate the effect of SBD on gut colonization and translocation. Twenty-four rats received enteral polymixin E, tobramycin, amphotericin B, and parenteral cefotaxime for 7 days (PTA + CEF); 23 received parenteral cefotaxime alone (CEF), 19 received the enteral antibiotics alone (PTA), 21 controls received no antibiotics. Cecal homogenates, mesenteric lymph node (MLN), liver, and spleen were cultured. Only 8% of the PTA + CEF group had gram-negative bacteria in cecal culture vs 52% CEF, 84% PTA, and 100% in controls. Log Enterococcal colony counts were higher in the PTA + CEF group (8.0 + 0.9) vs controls (5.4 + 0.4) P less than 0.01. Translocation of Enterococcus to the MLN was significantly increased in the PTA + CEF group (67%) vs controls (0%) P less than 0.01. SBD effectively eliminates gram-negative organisms from the gut in the rat model. Overgrowth and translocation of Enterococcus suggests that infection with gram-positive organisms may be a limitation of SBD.

Bacilos Gram negativos entéricos y no fermentadores de la glucosa en pacientes con enfermedad periimplante

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Jessika Consuegra

2011-04-01

Conclusiones. Un tercio de los implantes estudiados presentaron organismos sobreinfecciosos. Los implantes con lesiones periimplante presentan una mayor frecuencia de bacterias sobreinfecciosas. K. pneumoniae es la especie sobreinfecciosa más frecuente en los implantes estudiados. Se presentó infección múltiple con dichas bacterias en los implantes afectados. Estos microorganismos pueden afectar la estabilidad de los implantes.

Derecho positivo y derecho natural: una reflexión desde el iusnaturalismo sobre la necesidad y naturaleza de la determinación

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Sebastián Contreras

2013-06-01

Full Text Available El presente trabajo intenta analizar la naturaleza de la derivatio per modum determinationis. La filosofía escolástica enseña que la determinatio es uno de los modos de derivarse la ley humana desde la ley natural, particularmente el modo en que se deriva el derecho positivo o civil. En este trabajo el autor se detiene a revisar su modalidad, así como algunos criterios para reconocer las determinaciones o normas positivas.O presente trabalho procura analisar a natureza da derivatio per modum determinationis. A filosofia escolástica ensina que a determinatio é um dos modos por meio dos quais se deriva a lei humana a partir da lei natural, particularmente o modo no qual se deriva o direito positivo ou civil. Neste trabalho o autor se detém a revisar sua modalidade, bem como alguns critérios para reconhecer as determinações ou normas positivas.

Organo-Selenium Coatings Inhibit Gram-Negative and Gram-Positive Bacterial Attachment to Ophthalmic Scleral Buckle Material.

Science.gov (United States)

Tran, Phat; Arnett, Avery; Jarvis, Courtney; Mosley, Thomas; Tran, Khien; Hanes, Rob; Webster, Dan; Mitchell, Kelly; Dominguez, Leo; Hamood, Abdul; Reid, Ted W

2017-09-01

Biofilm formation is a problem for solid and sponge-type scleral buckles. This can lead to complications that require removal of the buckle, and result in vision loss due to related ocular morbidity, primarily infection, or recurrent retinal detachment. We investigate the ability of a covalent organo-selenium coating to inhibit biofilm formation on a scleral buckle. Sponge and solid Labtican brand scleral buckles were coated with organo-selenium coupled to a silyation reagent. Staphylococcus aureus biofilm formation was monitored by a standard colony-forming unit assay and the confocal laser scanning microscopy, while Pseudomonas aeruginosa biofilm formation was examined by scanning electron microscopy. Stability studies were done, by soaking in phosphate buffer saline (PBS) at room temperature for 2 months. Toxicity against human corneal epithelial cell was examined by growing the cells in the presence of organo-selenium-coated scleral buckles. The organo-selenium coating inhibited biofilm formation by gram-negative and gram-positive bacteria. The buckle coatings also were shown to be fully active after soaking in PBS for 2 months. The organo-selenium coatings had no effect on the viability of human corneal epithelial cells. Organo-selenium can be used to covalently coat a scleral buckle, which is stable and inhibits biofilm formation for gram-negative and gram-positive bacteria. The organo-selenium buckle coating was stable and nontoxic to cell culture. This technology provides a means to inhibit bacterial attachment to devices attached to the eye, without damage to ocular cells.

Silver enhances antibiotic activity against gram-negative bacteria.

Science.gov (United States)

Morones-Ramirez, J Ruben; Winkler, Jonathan A; Spina, Catherine S; Collins, James J

2013-06-19

A declining pipeline of clinically useful antibiotics has made it imperative to develop more effective antimicrobial therapies, particularly against difficult-to-treat Gram-negative pathogens. Silver has been used as an antimicrobial since antiquity, yet its mechanism of action remains unclear. We show that silver disrupts multiple bacterial cellular processes, including disulfide bond formation, metabolism, and iron homeostasis. These changes lead to increased production of reactive oxygen species and increased membrane permeability of Gram-negative bacteria that can potentiate the activity of a broad range of antibiotics against Gram-negative bacteria in different metabolic states, as well as restore antibiotic susceptibility to a resistant bacterial strain. We show both in vitro and in a mouse model of urinary tract infection that the ability of silver to induce oxidative stress can be harnessed to potentiate antibiotic activity. Additionally, we demonstrate in vitro and in two different mouse models of peritonitis that silver sensitizes Gram-negative bacteria to the Gram-positive-specific antibiotic vancomycin, thereby expanding the antibacterial spectrum of this drug. Finally, we used silver and antibiotic combinations in vitro to eradicate bacterial persister cells, and show both in vitro and in a mouse biofilm infection model that silver can enhance antibacterial action against bacteria that produce biofilms. This work shows that silver can be used to enhance the action of existing antibiotics against Gram-negative bacteria, thus strengthening the antibiotic arsenal for fighting bacterial infections.

Physico-Chemical-Managed Killing of Penicillin-Resistant Static and Growing Gram-Positive and Gram-Negative Vegetative Bacteria

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Richmond, Robert Chaffee (Inventor); Schramm, Jr., Harry F. (Inventor); Defalco, Francis G. (Inventor); Farris, III, Alex F. (Inventor)

2012-01-01

Systems and methods for the use of compounds from the Hofmeister series coupled with specific pH and temperature to provide rapid physico-chemical-managed killing of penicillin-resistant static and growing Gram-positive and Gram-negative vegetative bacteria. The systems and methods represent the more general physico-chemical enhancement of susceptibility for a wide range of pathological macromolecular targets to clinical management by establishing the reactivity of those targets to topically applied drugs or anti-toxins.

Utility of Gram staining for diagnosis of Malassezia folliculitis.

Science.gov (United States)

Tu, Wei-Ting; Chin, Szu-Ying; Chou, Chia-Lun; Hsu, Che-Yuan; Chen, Yu-Tsung; Liu, Donald; Lee, Woan-Ruoh; Shih, Yi-Hsien

2018-02-01

Malassezia folliculitis (MalF) mimics acne vulgaris and bacterial folliculitis in clinical presentations. The role of Gram staining in rapid diagnosis of MalF has not been well studied. In our study, 32 patients were included to investigate the utility of Gram staining for MalF diagnosis. The final diagnoses of MalF were determined according to clinical presentation, pathological result and treatment response to antifungal agents. Our results show that the sensitivity and specificity of Gram staining are 84.6% and 100%, respectively. In conclusion, Gram staining is a rapid, non-invasive, sensitive and specific method for MalF diagnosis. © 2017 Japanese Dermatological Association.

Defining a role for Hfq in Gram-positive bacteria

DEFF Research Database (Denmark)

Nielsen, Jesper Sejrup; Lei, Lisbeth Kristensen; Ebersbach, Tine

2010-01-01

Small trans-encoded RNAs (sRNAs) modulate the translation and decay of mRNAs in bacteria. In Gram-negative species, antisense regulation by trans-encoded sRNAs relies on the Sm-like protein Hfq. In contrast to this, Hfq is dispensable for sRNA-mediated riboregulation in the Gram-positive species......-dependent and -independent mechanisms, thus adding another layer of complexity to sRNA-mediated riboregulation in Gram-positive species....

In vitro activity of XF-73, a novel antibacterial agent, against antibiotic-sensitive and -resistant Gram-positive and Gram-negative bacterial species.

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Farrell, David J; Robbins, Marion; Rhys-Williams, William; Love, William G

2010-06-01

The antibacterial activity of XF-73, a dicationic porphyrin drug, was investigated against a range of Gram-positive and Gram-negative bacteria with known antibiotic resistance profiles, including resistance to cell wall synthesis, protein synthesis, and DNA and RNA synthesis inhibitors as well as cell membrane-active antibiotics. Antibiotic-sensitive strains for each of the bacterial species tested were also included for comparison purposes. XF-73 was active [minimum inhibitory concentration (MIC) 0.25-4 mg/L] against all of the Gram-positive bacteria tested, irrespective of the antibiotic resistance profile of the isolates, suggesting that the mechanism of action of XF-73 is unique compared with the major antibiotic classes. Gram-negative activity was lower (MIC 1 mg/L to > 64 mg/L). Minimum bactericidal concentration data confirmed that the activity of XF-73 was bactericidal. Time-kill kinetics against healthcare-associated and community-associated meticillin-resistant Staphylococcus aureus isolates demonstrated that XF-73 was rapidly bactericidal, with > 5 log(10) kill obtained after 15 min at 2 x MIC, the earliest time point sampled. The post-antibiotic effect (PAE) for XF-73 under conditions where the PAE for vancomycin was 5.4 h. XF-73 represents a novel broad-spectrum Gram-positive antibacterial drug with potentially beneficial characteristics for the treatment and prevention of Gram-positive bacterial infections. 2010. Published by Elsevier B.V.

A Synthetic Dual Drug Sideromycin Induces Gram-Negative Bacteria To Commit Suicide with a Gram-Positive Antibiotic.

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Liu, Rui; Miller, Patricia A; Vakulenko, Sergei B; Stewart, Nichole K; Boggess, William C; Miller, Marvin J

2018-05-10

Many antibiotics lack activity against Gram-negative bacteria because they cannot permeate the outer membrane or suffer from efflux and, in the case of β-lactams, are degraded by β-lactamases. Herein, we describe the synthesis and studies of a dual drug conjugate (1) of a siderophore linked to a cephalosporin with an attached oxazolidinone. The cephalosporin component of 1 is rapidly hydrolyzed by purified ADC-1 β-lactamase to release the oxazolidinone. Conjugate 1 is active against clinical isolates of Acinetobacter baumannii as well as strains producing large amounts of ADC-1 β-lactamase. Overall, the results are consistent with siderophore-mediated active uptake, inherent activity of the delivered dual drug, and in the presence of β-lactamases, intracellular release of the oxazolidinone upon cleavage of the cephalosporin to allow the freed oxazolidinone to inactivate its target. The ultimate result demonstrates that Gram-positive oxazolidinone antibiotics can be made to be effective against Gram-negative bacteria by β-lactamase triggered release.

Antimicrobial Activities of Leaf Extracts of Guava (Psidium guajava L.) on Two Gram-Negative and Gram-Positive Bacteria

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Biswas, Bipul; Rogers, Kimberly; McLaughlin, Fredrick; Yadav, Anand

2013-01-01

Aim. To determine the antimicrobial potential of guava (Psidium guajava) leaf extracts against two gram-negative bacteria (Escherichia coli and Salmonella enteritidis) and two gram-positive bacteria (Staphylococcus aureus and Bacillus cereus) which are some of foodborne and spoilage bacteria. The guava leaves were extracted in four different solvents of increasing polarities (hexane, methanol, ethanol, and water). The efficacy of these extracts was tested against those bacteria through a well-diffusion method employing 50 μL leaf-extract solution per well. According to the findings of the antibacterial assay, the methanol and ethanol extracts of the guava leaves showed inhibitory activity against gram-positive bacteria, whereas the gram-negative bacteria were resistant to all the solvent extracts. The methanol extract had an antibacterial activity with mean zones of inhibition of 8.27 and 12.3 mm, and the ethanol extract had a mean zone of inhibition of 6.11 and 11.0 mm against B. cereus and S. aureus, respectively. On the basis of the present finding, guava leaf-extract might be a good candidate in the search for a natural antimicrobial agent. This study provides scientific understanding to further determine the antimicrobial values and investigate other pharmacological properties. PMID:24223039

Antimicrobial Activities of Leaf Extracts of Guava (Psidium guajava L. on Two Gram-Negative and Gram-Positive Bacteria

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Bipul Biswas

2013-01-01

Full Text Available Aim. To determine the antimicrobial potential of guava (Psidium guajava leaf extracts against two gram-negative bacteria (Escherichia coli and Salmonella enteritidis and two gram-positive bacteria (Staphylococcus aureus and Bacillus cereus which are some of foodborne and spoilage bacteria. The guava leaves were extracted in four different solvents of increasing polarities (hexane, methanol, ethanol, and water. The efficacy of these extracts was tested against those bacteria through a well-diffusion method employing 50 μL leaf-extract solution per well. According to the findings of the antibacterial assay, the methanol and ethanol extracts of the guava leaves showed inhibitory activity against gram-positive bacteria, whereas the gram-negative bacteria were resistant to all the solvent extracts. The methanol extract had an antibacterial activity with mean zones of inhibition of 8.27 and 12.3 mm, and the ethanol extract had a mean zone of inhibition of 6.11 and 11.0 mm against B. cereus and S. aureus, respectively. On the basis of the present finding, guava leaf-extract might be a good candidate in the search for a natural antimicrobial agent. This study provides scientific understanding to further determine the antimicrobial values and investigate other pharmacological properties.

Capital psicológico positivo: validación del cuestionario PCQ en España

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Garazi Azanza

2014-01-01

Full Text Available En este estudio se describe el constructo de capital psicológico positivo (Luthans y Youssef, 2004 y la validación en España de un instrumento para medirlo: el PCQ (Psychological Capital Questionnaire. Este cuestionario mide cuatro aspectos diferentes, aunque relacionados entre sí, del concepto más amplio de capital psicológico. Estos aspectos son la autoeficacia, la esperanza, el optimismo y la resiliencia. Los resultados obtenidos (N = 372 a través del modelado de ecuaciones estructurales confirmaron que la versión española del cuestionario presenta una alta fiabilidad, así como validez convergente y discriminante. Se discuten los resultados, aportaciones y limitaciones del presente estudio.

Resistencia a los antibacterianos en América Latina: consecuencias para la infectología Antibacterial drug resistance in Latin America: consequences for infectious disease control

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José María Casellas

2011-12-01

antibióticos, existen varias opciones para tratar infecciones por bacterias grampositivas. La situación terapéutica no es igual para las infecciones por enterobacterias y por bacilos gram­negativos no fermentadores, donde las opciones resultan aún insuficientes para el tratamiento adecuado de los pacientes.Antibacterial drug resistance is a particularly significant issue in Latin America. This article explores antimicrobial resistance in three classes of clinically important bacteria: gram-positive bacteria, enterobacteria, and nonfermenting gram-negative bacilli. The gram-positive bacteria frequently responsible for infections in humans are for the most part cocci: staphylococci, streptococci (including pneumococci, and enterococci, in both community and hospital settings. This situation is no different in the Region of the Americas. Among the gram-positive bacteria, the causative agents of bacteremia are most commonly strains of coagulase-negative Staphylococcus, followed by enterococci. This report explores the resistance of these species to different antimicrobial drugs, resistance mechanisms in community and hospital strains, and new drugs for treating infections caused by these bacteria. In Latin America, antimicrobial resistance in Enterococcus strains is still a minor problem compared to the situation in the United States. The strains of the genus Streptococcus isolated from respiratory infections are still sensitive to penicillin. Furthermore, the resistance of enterobacteria is extremely important in the Region, particularly because of the broad dissemination of CTX-M extended-spectrum beta-lactamases (ESBL, some of which originated in Latin America. This article analyzes the resistance of Streptococcus pneumoniae, beta­hemolytic streptococci, and viridans group streptococci. Among the nonfermenting gram-negative bacilli, while Pseudomonas aeruginosa strains remain the leading cause of bacteremia, infections caused by strains of Acinetobacter spp. have

A flow-cytometric gram-staining technique for milk-associated bacteria.

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Holm, Claus; Jespersen, Lene

2003-05-01

A Gram-staining technique combining staining with two fluorescent stains, Oregon Green-conjugated wheat germ agglutinin (WGA) and hexidium iodide (HI) followed by flow-cytometric detection is described. WGA stains gram-positive bacteria while HI binds to the DNA of all bacteria after permeabilization by EDTA and incubation at 50 degrees C for 15 min. For WGA to bind to gram-positive bacteria, a 3 M potassium chloride solution was found to give the highest fluorescence intensity. A total of 12 strains representing some of the predominant bacterial species in bulk tank milk and mixtures of these were stained and analyzed by flow cytometry. Overall, the staining method showed a clear differentiation between gram-positive and gram-negative bacterial populations. For stationary-stage cultures of seven gram-positive bacteria and five gram-negative bacteria, an average of 99% of the cells were correctly interpreted. The method was only slightly influenced by the growth phase of the bacteria or conditions such as freezing at -18 degrees C for 24 h. For any of these conditions, an average of at least 95% of the cells were correctly interpreted. When stationary-stage cultures were stored at 5 degrees C for 14 days, an average of 86% of the cells were correctly interpreted. The Gram-staining technique was applied to the flow cytometry analysis of bulk tank milk inoculated with Staphylococcus aureus and Escherichia coli. These results demonstrate that the technique is suitable for analyzing milk samples without precultivation.

Methods for targetted mutagenesis in gram-positive bacteria

Science.gov (United States)

Yang, Yunfeng

2014-05-27

The present invention provides a method of targeted mutagenesis in Gram-positive bacteria. In particular, the present invention provides a method that effectively integrates a suicide integrative vector into a target gene in the chromosome of a Gram-positive bacterium, resulting in inactivation of the target gene.

Revisiting the Gram-negative lipoprotein paradigm.

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LoVullo, Eric D; Wright, Lori F; Isabella, Vincent; Huntley, Jason F; Pavelka, Martin S

2015-05-01

The processing of lipoproteins (Lpps) in Gram-negative bacteria is generally considered an essential pathway. Mature lipoproteins in these bacteria are triacylated, with the final fatty acid addition performed by Lnt, an apolipoprotein N-acyltransferase. The mature lipoproteins are then sorted by the Lol system, with most Lpps inserted into the outer membrane (OM). We demonstrate here that the lnt gene is not essential to the Gram-negative pathogen Francisella tularensis subsp. tularensis strain Schu or to the live vaccine strain LVS. An LVS Δlnt mutant has a small-colony phenotype on sucrose medium and increased susceptibility to globomycin and rifampin. We provide data indicating that the OM lipoprotein Tul4A (LpnA) is diacylated but that it, and its paralog Tul4B (LpnB), still sort to the OM in the Δlnt mutant. We present a model in which the Lol sorting pathway of Francisella has a modified ABC transporter system that is capable of recognizing and sorting both triacylated and diacylated lipoproteins, and we show that this modified system is present in many other Gram-negative bacteria. We examined this model using Neisseria gonorrhoeae, which has the same Lol architecture as that of Francisella, and found that the lnt gene is not essential in this organism. This work suggests that Gram-negative bacteria fall into two groups, one in which full lipoprotein processing is essential and one in which the final acylation step is not essential, potentially due to the ability of the Lol sorting pathway in these bacteria to sort immature apolipoproteins to the OM. This paper describes the novel finding that the final stage in lipoprotein processing (normally considered an essential process) is not required by Francisella tularensis or Neisseria gonorrhoeae. The paper provides a potential reason for this and shows that it may be widespread in other Gram-negative bacteria. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Multi-location gram-positive and gram-negative bacterial protein subcellular localization using gene ontology and multi-label classifier ensemble.

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Wang, Xiao; Zhang, Jun; Li, Guo-Zheng

2015-01-01

It has become a very important and full of challenge task to predict bacterial protein subcellular locations using computational methods. Although there exist a lot of prediction methods for bacterial proteins, the majority of these methods can only deal with single-location proteins. But unfortunately many multi-location proteins are located in the bacterial cells. Moreover, multi-location proteins have special biological functions capable of helping the development of new drugs. So it is necessary to develop new computational methods for accurately predicting subcellular locations of multi-location bacterial proteins. In this article, two efficient multi-label predictors, Gpos-ECC-mPLoc and Gneg-ECC-mPLoc, are developed to predict the subcellular locations of multi-label gram-positive and gram-negative bacterial proteins respectively. The two multi-label predictors construct the GO vectors by using the GO terms of homologous proteins of query proteins and then adopt a powerful multi-label ensemble classifier to make the final multi-label prediction. The two multi-label predictors have the following advantages: (1) they improve the prediction performance of multi-label proteins by taking the correlations among different labels into account; (2) they ensemble multiple CC classifiers and further generate better prediction results by ensemble learning; and (3) they construct the GO vectors by using the frequency of occurrences of GO terms in the typical homologous set instead of using 0/1 values. Experimental results show that Gpos-ECC-mPLoc and Gneg-ECC-mPLoc can efficiently predict the subcellular locations of multi-label gram-positive and gram-negative bacterial proteins respectively. Gpos-ECC-mPLoc and Gneg-ECC-mPLoc can efficiently improve prediction accuracy of subcellular localization of multi-location gram-positive and gram-negative bacterial proteins respectively. The online web servers for Gpos-ECC-mPLoc and Gneg-ECC-mPLoc predictors are freely accessible

Detection and Antibiotic Susceptibility Pattern of Biofilm Producing Gram Positive and Gram Negative Bacteria Isolated From a Tertiary Care Hospital of Pakistan

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Iqbal, M.

2011-01-01

Full Text Available Microorganisms adhere to non-living material or living tissue, and form biofilms made up of extracellular polymers/slime. Biofilm-associated microorganisms behave differently from free-floating bacteria with respect to growth rates and ability to resist antimicrobial treatments and therefore pose a public health problem. The objective of this study is to detect the prevalence of biofilm producers among Gram positive and Gram negative bacteria isolated from clinical specimens, and to study their antimicrobial susceptibility pattern. The study was carried out from October 2009 to March 2010, at the Department of Microbiology, Army Medical College/ National University of Sciences and Technology (NUST, Rawalpindi, Pakistan. Clinical specimens were received from various wards of a tertiary care hospital. These were dealt by standard microbiological procedures. Gram positive and Gram negative bacteria isolated were subjected to biofilm detection by congo red agar method (CRA. Antimicrobial susceptibility testing of those isolates, which showed positive results (slime production, was done according to the Kirby-Bauer disc diffusion technique. A total of 150 isolates were tested for the production of biofilm/slime. Among them, 81 isolates showed positive results. From these 81, 51 were Gram positive and 30 were Gram negative. All the 81(54% slime producers showed reduced susceptibility to majority of antibiotics. Bacterial biofilms are an important virulence factor associated with chronic nosocomial infection. Detection of biofilm forming organisms can help in appropriate antibiotic choice.

Chemical composition and antimicrobial activity of essential oils of Ocimum canum Sims. and Ocimum selloi Benth.

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Jeferson C. Nascimento

2011-09-01

linalol foram identificadas como os seus principais componentes. Todos os óleos extraídos das partes aéreas apresentaram atividade biológica contra cocos gram-positivo - Staphylococcus aureus ATCC 25923 - mas apenas aquele de O. canum apresentou atividade contra bacilo gram-negativo - Escherichia coli ATCC 25922.

Should gram stains have a role in diagnosing hip arthroplasty infections?

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Johnson, Aaron J; Zywiel, Michael G; Stroh, D Alex; Marker, David R; Mont, Michael A

2010-09-01

The utility of Gram stains in diagnosing periprosthetic infections following total hip arthroplasty has recently been questioned. Several studies report low sensitivity of the test, and its poor ability to either confirm or rule out infection in patients undergoing revision total hip arthroplasty. Despite this, many institutions including that of the senior author continue to perform Gram stains during revision total hip arthroplasty. We assessed the sensitivity, specificity, accuracy, and positive and negative predictive values of Gram stains from surgical-site samplings taken from procedures on patients with both infected and aseptic revision total hip arthroplasties. A review was performed on patients who underwent revision total hip arthroplasty between 2000 and 2007. Eighty-two Gram stains were performed on patients who had infected total hip arthroplasties and underwent revision procedures. Additionally, of the 410 revision total hip arthroplasties performed on patients who were confirmed infection-free, 120 Gram stains were performed. Patients were diagnosed as infected using multiple criteria at the time of surgery. Sensitivity, specificity, positive and negative predictive values, and accuracy were calculated from these Gram stain results. The Gram stain demonstrated a sensitivity and specificity of 9.8% and 100%, respectively. In this series, the Gram stain had a negative predictive value of 62%, a positive predictive value of 100%, and an accuracy of 63%. Gram stains obtained from surgical-site samples had poor sensitivity and poor negative predictive value. Based on these findings, as well as those of other authors, we believe that Gram stains should no longer be considered for diagnosing infections in revision total hip arthroplasty. Level III, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.

Glass bead transformation method for gram-positive bacteria

OpenAIRE

Rattanachaikunsopon, Pongsak; Phumkhachorn, Parichat

2009-01-01

A simple, inexpensive and reproducible transformation method was developed for Gram-positive bacteria. It was based on agitation of bacterial protoplasts with glass beads in the presence of DNA and polyethylene glycol. By using this method, introduction of pGK12 into protoplasts of several strains of Gram-positive bacteria was achieved.

A pathway closely related to the (D)-tagatose pathway of gram-negative enterobacteria identified in the gram-positive bacterium Bacillus licheniformis.

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Van der Heiden, Edwige; Delmarcelle, Michaël; Lebrun, Sarah; Freichels, Régine; Brans, Alain; Vastenavond, Christian M; Galleni, Moreno; Joris, Bernard

2013-06-01

We report the first identification of a gene cluster involved in d-tagatose catabolism in Bacillus licheniformis. The pathway is closely related to the d-tagatose pathway of the Gram-negative bacterium Klebsiella oxytoca, in contrast to the d-tagatose 6-phosphate pathway described in the Gram-positive bacterium Staphylococcus aureus.

A Pathway Closely Related to the d-Tagatose Pathway of Gram-Negative Enterobacteria Identified in the Gram-Positive Bacterium Bacillus licheniformis

OpenAIRE

Van der Heiden, Edwige; Delmarcelle, Michaël; Lebrun, Sarah; Freichels, Régine; Brans, Alain; Vastenavond, Christian M.; Galleni, Moreno; Joris, Bernard

2013-01-01

We report the first identification of a gene cluster involved in d-tagatose catabolism in Bacillus licheniformis. The pathway is closely related to the d-tagatose pathway of the Gram-negative bacterium Klebsiella oxytoca, in contrast to the d-tagatose 6-phosphate pathway described in the Gram-positive bacterium Staphylococcus aureus.

A Pathway Closely Related to the d-Tagatose Pathway of Gram-Negative Enterobacteria Identified in the Gram-Positive Bacterium Bacillus licheniformis

Science.gov (United States)

Van der Heiden, Edwige; Lebrun, Sarah; Freichels, Régine; Brans, Alain; Vastenavond, Christian M.; Galleni, Moreno; Joris, Bernard

2013-01-01

We report the first identification of a gene cluster involved in d-tagatose catabolism in Bacillus licheniformis. The pathway is closely related to the d-tagatose pathway of the Gram-negative bacterium Klebsiella oxytoca, in contrast to the d-tagatose 6-phosphate pathway described in the Gram-positive bacterium Staphylococcus aureus. PMID:23524682

Decreased mortality associated with prompt Gram staining of blood cultures.

Science.gov (United States)

Barenfanger, Joan; Graham, Donald R; Kolluri, Lavanya; Sangwan, Gaurav; Lawhorn, Jerry; Drake, Cheryl A; Verhulst, Steven J; Peterson, Ryan; Moja, Lauren B; Ertmoed, Matthew M; Moja, Ashley B; Shevlin, Douglas W; Vautrain, Robert; Callahan, Charles D

2008-12-01

Gram stains of positive blood cultures are the most important factor influencing appropriate therapy. The sooner appropriate therapy is initiated, the better. Therefore, it is reasonable to expect that the sooner Gram stains are performed, the better. To determine the value of timely Gram stains and whether improvement in Gram stain turnaround time (TAT) is feasible, we compared data for matched pairs of patients with cultures processed promptly ( or =1 hour TAT) and then monitored TAT by control charting.In 99 matched pairs, average difference in time to detection of positive blood cultures within a pair of patients was less than 0.1 hour. For the less than 1 hour TAT group, the average TAT and crude mortality were 0.1 hour and 10.1%, respectively; for the 1 hour or longer TAT group, they were 3.3 hours and 19.2%, respectively (P Gram stains.

Direito a moradia e inclusão social: aspectos positivos e negativos do "programa minha casa minha vida"

OpenAIRE

Desordi, Jordana Laís; Strücker, Bianca

2016-01-01

O presente artigo pretende analisar aspectos conceituais e doutrinários referentes ao direito à moradia e à inclusão social, fazendo referência aos aspectos positivos e negativos do programa habitacional brasileiro “Minha Casa Minha Vida” (PMCMV). A pesquisa dá ênfase ao PMCMV, momento em que é analisada a legislação que cria e institui o Programa em suas duas versões existentes até este momento. Destaca-se, ainda, os reflexos que o programa causou ao proporcionar o acesso do indivíduo a sua ...

Apoio comportamental positivo: estratégias educacionais aplicadas a comportamentos-problema de alunos

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Karyne de Souza Augusto Rios

Full Text Available Baseado no modelo de Apoio Comportamental Positivo o estudo objetivou identificar como 40 diretores de escolas de educação infantil descreviam o processo de elaboração, aplicação e avaliação de estratégias educativas para comportamentos-problema de alunos. Resultados do questionário apontaram que 77,5% dos diretores indicaram comportamentos-problema em seus alunos. As estratégias educativas mais utilizadas foram conversar com a criança (13,3% e conversar com pais (13,3%. A ação mais utilizada para a avaliação foi a observação da criança (27,6%. De forma geral, verificou-se que as estratégias utilizadas foram realizadas informal e assistematicamente. Aponta-se a necessidade de pesquisas sobre a inclusão de crianças com comportamentos-problema e o desafio de repensar a formação dos educadores.

Embedded Lattice and Properties of Gram Matrix

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Futa Yuichi

2017-03-01

Full Text Available In this article, we formalize in Mizar [14] the definition of embedding of lattice and its properties. We formally define an inner product on an embedded module. We also formalize properties of Gram matrix. We formally prove that an inverse of Gram matrix for a rational lattice exists. Lattice of Z-module is necessary for lattice problems, LLL (Lenstra, Lenstra and Lov´asz base reduction algorithm [16] and cryptographic systems with lattice [17].

Superficial corneal foreign body: laboratory and epidemiologic aspects Corpo estranho corneal superficial: aspectos laboratoriais e epidemiológicos

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Ednajar Tavares Macedo Filho

2005-12-01

�TODOS: Foi realizado estudo prospectivo em 101 pacientes que procuraram o Pronto-Socorro de Oftalmologia do Hospital São Paulo-UNIFESP/EPM, com diagnóstico de corpo estranho corneal. Previamente a qualquer tratamento o corpo estranho e amostra do fundo de saco conjuntival ipsilateral foram coletados em tubos separados com tioglicolato. Realizou-se semeadura em meios sólidos de ágar sangue, chocolate, Sabouraud e exame bacterioscópico com as colorações de Gram e Giemsa e antibiograma. Culturas positivas para o corpo estranho foram comparadas com as de fundo de saco conjuntival para excluir contaminação com flora normal. RESULTADOS: Cerca de 92% dos pacientes foram do sexo masculino, com idade média de 35 anos. O olho direito foi acometido em 62,4% (intervalo de confiança 95%: 52,2 - 71,8% da amostra e 32,7% (intervalo de confiança 95%: 23,7 - 42,7% apresentou crescimento bacteriano positivo em cultura. Os microrganismos encontrados nas culturas dos corpos estranhos foram: Streptococcus, alpha-hemolytic (n=4, Staphylococcus aureus (n=4, Staphylococcus, coagulase-negative (n=4, Corynebacterium xerosis (n=3, bacilo gram-positivo não identificado (n=2, Moraxella sp (n=1, Serratia sp (n=1, Acynetobacter sp (n=1. O antibiograma revelou que 95% dos casos foram sensíveis ao cloranfenicol e 90% a ciprofloxacina, antibióticos usados na rotina de nosso serviço. CONCLUSÃO: O corpo estranho corneal foi importante vetor de contaminação, porém a grande maioria dos microrganismos isolados foi sensível a antibioticoprofilaxia empregada no tratamento.

Actividad antibacteriana y caracterización química de extractos de plantas medicinales tradicionales del Ecuador

OpenAIRE

Chávez Carvajal, Patricia Alexandra

2014-01-01

Ambrosia arborescens Mill, Chuquiraga jussieui J.F. Gmel, Myrcianthes hallii (Berg) McVaugh, Solanum americanum mill y tropoeolum tuberosum Ruiz & Pav, plantas que crecen en Ecuador, son utilizadas en la medicina tradicional por sus propiedades antisépticas, cicatrizantes, astringentes, balsámicas, diuréticas, antidiarreicas, entre otras. Los extractos hidro-metanólicos acidificados de dichas plantas fueron probados contra diferentes especies de microorganismos Gram positivos y Gram negativos...

Gram-positive bacteria persisting in the food production environment

DEFF Research Database (Denmark)

Knøchel, Susanne; Harmsen, Morten; Knudsen, Bettina

2008-01-01

Many gram-positive bacteria are able to form aggregates or biofilms and resist external stress factors and some gram-positive pathogenic bacteria such as Listeria monocytogenes and Bacillus cereus may persist in the food production environment for extended periods. Most research has focussed...

Pulmonary infiltrates during community acquired Gram-negative bacteremia

DEFF Research Database (Denmark)

Fjeldsøe-Nielsen, Hans; Gjeraa, Kirsten; Berthelsen, Birgitte G

2013-01-01

The primary aim of this study was to describe the frequency of pulmonary infiltrates on chest X-ray (CXR) during community acquired Gram-negative bacteremia at a single centre in Denmark.......The primary aim of this study was to describe the frequency of pulmonary infiltrates on chest X-ray (CXR) during community acquired Gram-negative bacteremia at a single centre in Denmark....

Gram-positive rods prevailing in teeth with apical periodontitis undergoing root canal treatment.

Science.gov (United States)

Chávez de Paz, L E; Molander, A; Dahlén, G

2004-09-01

To identify Gram-positive rods from root canals of teeth with apical periodontitis and to examine their associations with other species. Consecutive root canal samples (RCSs) from 139 teeth undergoing root canal treatment were analyzed prospectively for cultivable microbes. Gram-positive rods in the first RCS submitted after chemo-mechanical preparation were categorised to genus level by selective media and gas-liquid chromatography (GLC), and identified to species level by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Associations between organisms were measured by odds ratios (OR). In the first samples submitted a total of 158 Gram-positive rods, 115 Gram-positive cocci, 26 Gram-negative rods and 9 Gram-negative cocci, were identified. At genus levels Gram-positive rods were classified into: Lactobacillus spp. (38%), Olsenella spp. (18%), Propionibacterium spp. (13%), Actinomyces spp. (12%), Bifidobacterium spp. (13%) and Eubacterium spp. (6%). The most frequent species were Olsenella uli, Lactobacillus paracasei and Propionibacterium propionicum. In subsequent samples taken during treatment, Gram-positive rods were also identified, although the number of strains was considerably reduced. Positive associations were observed between members of the genus lactobacilli and Gram-positive cocci (OR>2). Olsenella uli and Lactobacillus spp. predominated over other Gram-positive rods. A possible association exists between Lactobacillus spp. and Gram-positive cocci in root canals of teeth with apical periodontitis receiving treatment.

Is the gram stain useful in the microbiologic diagnosis of VAP? A meta-analysis.

Science.gov (United States)

O'Horo, John C; Thompson, Deb; Safdar, Nasia

2012-08-01

In a meta-analysis examining respiratory specimen Gram stain for diagnosis of ventilator-associated pneumonia, absence of bacteria on Gram stain had a high negative predictive value, but a positive Gram stain correlated poorly with organisms recovered in culture. Rapid and accurate diagnosis of ventilator-associated pneumonia (VAP) is a major challenge and no generally accepted gold standard exists for VAP diagnosis. We conducted a meta-analysis to examine the role of respiratory specimen Gram stain to diagnose VAP, and the correlation with final culture results. In 21 studies, pooled sensitivity of Gram stain for VAP was 0.79 (95% confidence interval [CI], .77-0.81; P Gram stain for a VAP prevalence of 20%-30% was 91%, suggesting that VAP is unlikely with a negative Gram stain but the positive predictive value of Gram stain was only 40%. Pooled kappa was 0.42 for gram-positive organisms and 0.34 for gram-negative organisms, suggesting fair concordance between organisms on Gram stain and recovery by culture. Therefore, a positive Gram stain should not be used to narrow anti-infective therapy until culture results become available.

Clasificación clínica y comportamiento de las poblaciones linfocitarias en VIH positivos

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R. H. Corral

1994-09-01

Full Text Available Con el fin de determinar el comportamiento de las diferente poblaciones linfocitarias, a través de los diferentes estadios clínicos de la infección por e lvirus de inmunodeficiencia humana (VIH establecidos por el CDC, se realizaron tipificaciones de linfocitos T, B, T CD4 y T CD8 en 155 individuos VIH positivos del ISS en Cali, utilizando la técnica de inmunocitoquimica de los complejos fosfatasa alcalina-antifosfatasa alcalina (APAAP en extendidos de sangre periférica. En los pacientes del estadio II, los linfocitos T, B y CD4 se encontraron dentro de los valores normales para la población general, mientras que los CD8 estaban aumentados. En el estadio III, el comportamiento de las poblaciones de linfocitos fue similar salvo un ligero aumento de los linfocitos B. Estos estadios sólo se diferenciaron clínicamente por la presencia de adenopatias. En el estadio IV se observó una marcada depleción detodas las poblaciones linfocitarias estudiadas. En virtud al aumento temprano de CD8 en los estadios II y III, la relación CD41CD8 presenta alteraciones y es menor de 1 ,O aunque el recuento de CD4 en estos estadios sea normal. Sin embargo, cuando ocurre la depleción general en el estadio IV, su utilidad es limitada y el recuento absoluto de CD4 es el indicador más útil en la progresión de la enfermedad. En virtud a que el recuento de linfocitos CD4 y CD8 constituye un pilar y en él se orientan la mayoría de las conductas profilácticas y de tratamiento que se adoptan en los VIH positivos, se hace necesario conducir los esfuerzos para hacer más asequible esta metodología a los pacientes, así como plantear la implementación de otras pruebas evaluadoras de la inmunidad, útiles como indicadores de la progresión de la enfermedad.

Amplifiable DNA from Gram-negative and Gram-positive bacteria by a low strength pulsed electric field method

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Vitzthum, Frank; Geiger, Georg; Bisswanger, Hans; Elkine, Bentsian; Brunner, Herwig; Bernhagen, Jürgen

2000-01-01

An efficient electric field-based procedure for cell disruption and DNA isolation is described. Isoosmotic suspensions of Gram-negative and Gram-positive bacteria were treated with pulsed electric fields of Pulses had an exponential decay waveform with a time constant of 3.4 µs. DNA yield was linearly dependent on time or pulse number, with several thousand pulses needed. Electrochemical side-effects and electrophoresis were minimal. The lysates contained non-fragmented DNA which was readily amplifiable by PCR. As the method was not limited to samples of high specific resistance, it should be applicable to physiological fluids and be useful for genomic and DNA diagnostic applications. PMID:10734214

Potential strategies for the eradication of multidrug-resistant Gram-negative bacterial infections.

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Huwaitat, Rawan; McCloskey, Alice P; Gilmore, Brendan F; Laverty, Garry

2016-07-01

Antimicrobial resistance is one of the leading threats to society. The increasing burden of multidrug-resistant Gram-negative infection is particularly concerning as such bacteria are demonstrating resistance to nearly all currently licensed therapies. Various strategies have been hypothesized to treat multidrug-resistant Gram-negative infections including: targeting the Gram-negative outer membrane; neutralization of lipopolysaccharide; inhibition of bacterial efflux pumps and prevention of protein folding. Silver and silver nanoparticles, fusogenic liposomes and nanotubes are potential strategies for extending the activity of licensed, Gram-positive selective, antibiotics to Gram-negatives. This may serve as a strategy to fill the current void in pharmaceutical development in the short term. This review outlines the most promising strategies that could be implemented to solve the threat of multidrug-resistant Gram-negative infections.

Comparative activity of tigecycline and tetracycline on Gram-negative and Gram-positive bacteria revealed by a multicentre study in four North European countries

DEFF Research Database (Denmark)

Nilsson, Lennart E; Frimodt-Møller, Niels; Vaara, Martti

2011-01-01

This study involves a multicentre surveillance of tigecycline and tetracycline activity against Gram-negative and Gram-positive bacteria from primary care centres (PCCs), general hospital wards (GHWs) and intensive care units (ICUs) in Denmark (n = 9), Finland (n = 10), Norway (n = 7) and Sweden (n...

Clonación de secuencias de alfavirus y flavivirus para su uso como controles positivos en el diagnóstico molecular

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Daría Camacho

Full Text Available El objetivo de la investigación fue obtener controles positivos para la validación de técnicas moleculares (RT-PCR utilizadas en diagnóstico e investigación de infecciones virales. A partir de cepas de CHIKV, Zika, DENV-1, DENV-2, DENV-3 y DENV-4, se extrajeron ARN virales para obtener por RT-PCR los ADN complementarios (ADNc de las secuencias nsP4 (CHIKV, NS5 (virus Zika, C/prM-M y 5´UTR-C (DENV-1, DENV-2, DENV-3, DENV-4 que fueron clonados en pGEM®-T Easy. La clonación se confirmó mediante PCR de colonias, de las cuales se extrajo el ADN plasmídico para la verificación de la clonación de los fragmentos. Se logró la clonación de ADNc correspondientes a nsP4, NS5, C/prM-M y 5´UTR-C de los distintos agentes virales. En conclusión se obtuvieron los plásmidos recombinantes con cada una de las secuencias especificadas para su posterior valoración como controles positivos en técnicas moleculares, evitando el uso de cultivos celulares que pueden resultar costosos, laboriosos y potencialmente peligrosos.

Sistema de tareas para la enseñanza combinada de la gramática comunicativa y la gramática tradicional de lengua inglesa

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Nancy del Carmen Jiménez Figueredo

2015-03-01

Full Text Available Se realizó el diseño de un sistema de tareas para la enseñanza combinada de la gramática comunicativa y la gramática tradicional de lengua inglesa, con metodología cuali-cuantitativa, en la Facultad de Ciencias Médicas “Zoilo Marinello Vidaurreta” de la Universidad de Ciencias Médicas de Las Tunas, durante el período comprendido entre septiembre de 2011 y julio de 2014. El objetivo estuvo direccionado a perfeccionar la corrección lingüística en el proceso de enseñanza-aprendizaje del idioma Inglés. La realización del diseño contó con: una revisión bibliográfica de los principales enfoques utilizados en la enseñanza-aprendizaje del Inglés; la revisión documental, que permitió determinar las insuficiencias lingüísticas y la necesidad de combinar la gramática comunicativa con la gramática tradicional, en los estudiantes del cuarto año de la carrera de Estomatología; el intercambio con profesionales con más de quince años de experiencia, para obtener información acerca del proceso de enseñanza-aprendizaje de la gramática; y la aplicación de una valoración equivalente al juicio de expertos, método de agregados individuales, para valorar la propuesta. Los principales resultados fueron: la caracterización de las insuficiencias provocadas por la absolutización del enfoque comunicativo en la enseñanza de la gramática de la lengua inglesa y el diseño de un sistema de tareas para el proceso de enseñanza-aprendizaje de la gramática inglesa en estos estudiantes

Antiadhesion agents against Gram-positive pathogens.

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Cascioferro, Stella; Cusimano, Maria Grazia; Schillaci, Domenico

2014-01-01

A fundamental step of Gram-positive pathogenesis is the bacterial adhesion to the host tissue involving interaction between bacterial surface molecules and host ligands. This review is focused on antivirulence compounds that target Gram-positive adhesins and on their potential development as therapeutic agents alternative or complementary to conventional antibiotics in the contrast of pathogens. In particular, compounds that target the sortase A, wall theicoic acid inhibitors, carbohydrates able to bind bacterial proteins and proteins capable of influencing the bacterial adhesion, were described. We further discuss the advantages and disadvantages of this strategy in the development of novel antimicrobials and the future perspective of this research field still at its first steps.

Cytokine profile in severe gram-positive and gram-negative abdominal sepsis

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Surbatovic, Maja; Popovic, Nada; Vojvodic, Danilo; Milosevic, Ivan; Acimovic, Gordana; Stojicic, Milan; Veljovic, Milic; Jevdjic, Jasna; Djordjevic, Dragan; Radakovic, Sonja

2015-01-01

Sepsis is a principal cause of death in critical care units worldwide and consumes considerable healthcare resources. The aim of our study was to determine whether the early cytokine profile can discriminate between Gram-positive and Gram-negative bacteraemia (GPB and GNB, respectively) and to assess the prognostic value regarding outcome in critically ill patients with severe abdominal sepsis. The outcome measure was hospital mortality. Blood samples were obtained from 165 adult patients with confirmed severe abdominal sepsis. Levels of the proinflammatory mediators TNF-α, IL-8, IL-12 and IFN-γ and the anti-inflammatory mediators IL-1ra, IL-4, IL-10 and TGF-β1 were determined and correlated with the nature of the bacteria isolated from the blood culture and outcome. The cytokine profile in our study indicated that the TNF-α levels were 2-fold, IL-8 were 3.3-fold, IFN-γ were 13-fold, IL-1ra were 1.05-fold, IL-4 were 1.4-fold and IL-10 were 1.83-fold higher in the GNB group compared with the GPB group. The TNF-α levels were 4.7-fold, IL-8 were 4.6-fold, IL-1ra were 1.5-fold and IL-10 were 3.3-fold higher in the non-survivors compared with the survivors. PMID:26079127

Concordância dos resultados do sistema BD Phoenix com provas bioquímicas manuais na identificação de Enterobactérias em amostras clínicas

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Natacha Allgayer

2015-02-01

Full Text Available Enterobactérias pertencem a um grupo grande e heterogêneo de bacilos Gram-negativos cujo habitat natural é o cólon de humanos e animais, sendo microrganismos amplamente distribuídos na natureza. Devido a essas características são frequentemente responsáveis por infecções hospitalares. O principal objetivo desse estudo foi estabelecer uma concordância entre as provas bioquímicas manuais e a automação BD Phoenix 100 na identificação de enterobactérias, a partir de uma análise de registros de pacientes hospitalizados. No período de Agosto de 2011 a Abril de 2012, foram realizados 303 exames no Laboratório Exame de Análises Clinicas pelo método manual e pela automação. Do total, 27,7% foram positivos para enterobactérias. Os microrganismos mais frequentes isolados, foram a Klebsiella pneumoniae 36,9%, seguido pela Escherichia coli 29,8%. O estudo apresentou uma alta concordância entre os métodos, principalmente na identificação dos gêneros. Na identificação das espécies, as bactérias dos gêneros Klebsiella spp. e Serratia spp. não tiveram suas espécies identificadas pelo método manual em sete dos registros observados, sendo identificadas somente pela automação. Assim como a Escherichia coli que não foi identificada pelo método manual, vista como indeterminada em quatro dos registros analisados. Portanto, verificou-se uma boa concordância entre os métodos na identificação das principais enterobactérias isoladas de amostras clínicas.

Caracterización molecular y resistencia antimicrobiana de aislamientos de Clostridium perfringens de diferentes orígenes en Costa Rica

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María del Mar Gamboa-Coronado

2011-12-01

Full Text Available Clostridium perfringens es un bacilo Gram positivo, esporulado, anaerobio, ampliamente distribuido en la naturaleza, que produce cuatro toxinas principales α, β, ε y ι, las cuales permiten su clasificación en cinco toxinotipos (A-E. Algunas cepas producen una enterotoxina (CPE, codificada por el gen cpe, que causa diarrea en seres humanos y en algunos animales. La presencia de los genes de estas toxinas y la sensibilidad a los antibióticos se determinó en 81 cepas de C. perfringens previamente aisladas y que habían sido mantenidas a -80°C; 20 de suelos, 20 de origen animal, 20 de origen humano y 21 de alimentos cocidos no relacionados con brotes alimentarios. De acuerdo con los resultados de PCR, todas las cepas fueron clasificadas como C. perfringens tipo A, debido a que solo se les detectó el gen de la toxina α, mientras que el gen de la enterotoxina (cpe se detectó en dos cepas (2.5% aisladas de alimentos, tal como ha sido descrito en otras regiones del mundo. El 44% de las cepas fue resistente a algún antibiótico; clindamicina (41%, cloranfenicol (25%, penicilina (22% y metronidazol (20%. En general, las cepas provenientes de suelos presentaron los mayores porcentajes de resistencia a casi todos los antibióticos. El 40% de las cepas de suelo presentó multiresistencia (a tres o más grupos de antibióticos, el 30% de las de origen humano, el 14% de las de alimentos y el 5% de las de origen animal. Las altas tasas de resistencia encontradas podrían deberse al amplio uso de antibióticos como promotores de crecimiento de plantas y animales y esas cepas resistentes podrían actuar como reservorio de genes de resistencia que pueden transferirse entre bacterias de diversos ambientes.

Neutropenia febril en el trópico: una descripción de los hallazgos clínicos y microbiológicos y el impacto de la terapia inapropiada que utilizan en un centro de referencia oncológica en Colombia

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Jorge A. Cortés

2013-03-01

Full Text Available Introducción. La neutropenia febril es una complicación frecuente de la quimioterapia para las neoplasias hematológicas. Se dispone de escasa información de sus complicaciones infecciosas en nuestro medio. Objetivo. Evaluar las características clínicas y microbiológicas de pacientes con neutropenia febril, así como su resultado clínico en una institución de referencia oncológica en Colombia. Materiales y métodos. Se conformó prospectivamente una serie de casos con pacientes con enfermedad oncológica confirmada, que consultaron o presentaron neutropenia febril durante la hospitalización. Se excluyeron aquellos con enfermedad hematológica benigna. Se recolectaron datos sobre variables demográficas, microbiológicas, clínicas, de tratamiento y de resultado de los pacientes. Se llevaron a cabo un análisis univariado y uno multivariado, con la mortalidad como resultado. Resultados. Se identificaron 130 episodios de neutropenia febril en 104 pacientes, con una edad media de 19 años y 53 % masculinos. El 86 % de los episodios ocurrieron en pacientes con alteraciones hematológicas. Se demostró infección en 65 % de los casos: 41 % con un foco infeccioso localizado y 27,7 % con bacteriemia. Los principales focos infecciosos se localizaron en el torrente sanguíneo, el aparato urinario, el sistema gastrointestinal, la piel y los tejidos blandos. De los aislamientos microbiológicos, 46,4 % fueron bacilos Gram negativos, 38,4 %, cocos Gram positivos, 9 %, hongos y, 7,1%, parásitos. La mortalidad global fue de 7,7 %. En el análisis multivariado la utilización de un tratamiento empírico apropiado se correlacionó con una menor mortalidad, de forma independiente (OR=0,17; IC95% 0,034-0,9; p=0,037. Conclusiones. La tasa de mortalidad fue relativamente baja y fue comparable con lo reportado en países desarrollados. El tratamiento antimicrobiano inapropiado fue el principal factor asociado con mortalidad.   doi: http://dx.doi.org/10

Will new antimicrobials overcome resistance among Gram-negatives?

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Bassetti, Matteo; Ginocchio, Francesca; Mikulska, Małgorzata; Taramasso, Lucia; Giacobbe, Daniele Roberto

2011-10-01

The spread of resistance among Gram-positive and Gram-negative bacteria represents a growing challenge for the development of new antimicrobials. The pace of antibiotic drug development has slowed during the last decade and, especially for Gram-negatives, clinicians are facing a dramatic shortage in the availability of therapeutic options to face the emergency of the resistance problem throughout the world. In this alarming scenario, although there is a shortage of compounds reaching the market in the near future, antibiotic discovery remains one of the keys to successfully stem and maybe overcome the tide of resistance. Analogs of already known compounds and new agents belonging to completely new classes of antimicrobials are in early stages of development. Novel and promising anti-Gram-negative antimicrobials belong both to old (cephalosporins, carbapenems, β-lactamase inhibitors, monobactams, aminoglycosides, polymyxin analogues and tetracycline) and completely new antibacterial classes (boron-containing antibacterial protein synthesis inhibitors, bis-indoles, outer membrane synthesis inhibitors, antibiotics targeting novel sites of the 50S ribosomal subunit and antimicrobial peptides). However, all of these compounds are still far from being introduced into clinical practice. Therefore, infection control policies and optimization in the use of already existing molecules are still the most effective approaches to reduce the spread of resistance and preserve the activity of antimicrobials.

Outcomes of single organism peritonitis in peritoneal dialysis: gram negatives versus gram positives in the Network 9 Peritonitis Study.

Science.gov (United States)

Bunke, C M; Brier, M E; Golper, T A

1997-08-01

The use of the "peritonitis rate" in the management of patients undergoing peritoneal dialysis is assuming importance in comparing the prowess of facilities, care givers and new innovations. For this to be a meaningful outcome measure, the type of infection (causative pathogen) must have less clinical significance than the number of infections during a time interval. The natural history of Staphylococcus aureus, pseudomonas, and fungal peritonitis would not support that the outcome of an episode of peritonitis is independent of the causative pathogen. Could this concern be extended to other more frequently occurring pathogens? To address this, the Network 9 Peritonitis Study identified 530 episodes of single organism peritonitis caused by a gram positive organism and 136 episodes caused by a single non-pseudomonal gram negative (NPGN) pathogen. Coincidental soft tissue infections (exit site or tunnel) occurred equally in both groups. Outcomes of peritonitis were analyzed by organism classification and by presence or absence of a soft tissue infection. NPGN peritonitis was associated with significantly more frequent catheter loss, hospitalization, and technique failure and was less likely to resolve regardless of the presence or absence of a soft tissue infection. Hospitalization and death tended to occur more frequently with enterococcal peritonitis than with other gram positive peritonitis. The outcomes in the NPGN peritonitis group were significantly worse (resolution, catheter loss, hospitalization, technique failure) compared to coagulase negative staphylococcal or S. aureus peritonitis, regardless of the presence or absence of a coincidental soft tissue infection. Furthermore, for the first time, the poor outcomes of gram negative peritonitis are shown to be independent of pseudomonas or polymicrobial involvement or soft tissue infections. The gram negative organism appears to be the important factor. In addition, the outcome of peritonitis caused by S. aureus

Antimicrobial Photodynamic Therapy to Kill Gram-negative Bacteria

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Sperandio, Felipe F; Huang, Ying-Ying; Hamblin, Michael R

2013-01-01

Antimicrobial photodynamic therapy (PDT) or photodynamic inactivation (PDI) is a new promising strategy to eradicate pathogenic microorganisms such as Gram-positive and Gram-negative bacteria, yeasts and fungi. The search for new approaches that can kill bacteria but do not induce the appearance of undesired drug-resistant strains suggests that PDT may have advantages over traditional antibiotic therapy. PDT is a non-thermal photochemical reaction that involves the simultaneous presence of visible light, oxygen and a dye or photosensitizer (PS). Several PS have been studied for their ability to bind to bacteria and efficiently generate reactive oxygen species (ROS) upon photostimulation. ROS are formed through type I or II mechanisms and may inactivate several classes of microbial cells including Gram-negative bacteria such as Pseudomonas aeruginosa, which are typically characterized by an impermeable outer cell membrane that contains endotoxins and blocks antibiotics, dyes, and detergents, protecting the sensitive inner membrane and cell wall. This review covers significant peer-reviewed articles together with US and World patents that were filed within the past few years and that relate to the eradication of Gram-negative bacteria via PDI or PDT. It is organized mainly according to the nature of the PS involved and includes natural or synthetic food dyes; cationic dyes such as methylene blue and toluidine blue; tetrapyrrole derivatives such as phthalocyanines, chlorins, porphyrins, chlorophyll and bacteriochlorophyll derivatives; functionalized fullerenes; nanoparticles combined with different PS; other formulations designed to target PS to bacteria; photoactive materials and surfaces; conjugates between PS and polycationic polymers or antibodies; and permeabilizing agents such as EDTA, PMNP and CaCl2. The present review also covers the different laboratory animal models normally used to treat Gram-negative bacterial infections with antimicrobial PDT. PMID

Subcellular localization for Gram positive and Gram negative bacterial proteins using linear interpolation smoothing model.

Science.gov (United States)

Saini, Harsh; Raicar, Gaurav; Dehzangi, Abdollah; Lal, Sunil; Sharma, Alok

2015-12-07

Protein subcellular localization is an important topic in proteomics since it is related to a protein׳s overall function, helps in the understanding of metabolic pathways, and in drug design and discovery. In this paper, a basic approximation technique from natural language processing called the linear interpolation smoothing model is applied for predicting protein subcellular localizations. The proposed approach extracts features from syntactical information in protein sequences to build probabilistic profiles using dependency models, which are used in linear interpolation to determine how likely is a sequence to belong to a particular subcellular location. This technique builds a statistical model based on maximum likelihood. It is able to deal effectively with high dimensionality that hinders other traditional classifiers such as Support Vector Machines or k-Nearest Neighbours without sacrificing performance. This approach has been evaluated by predicting subcellular localizations of Gram positive and Gram negative bacterial proteins. Copyright © 2015 Elsevier Ltd. All rights reserved.

Relación entre el virus humano herpes 8 y el sarcoma de Kaposi en pacientes positivos y negativos para el VIH Relationship between human herpes virus 8 and Kaposi sarcomain HIV positive and negative patients

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BEATRIZ OROZCO

2007-09-01

Full Text Available Introducción. Parece existir una relación de causalidad entre la infección por el virus humano herpes 8 ( human Herpesvirus 8, HHV-8 y el desarrollo de sarcoma de Kaposi, especialmente en la población positiva para virus de inmunodeficiencia humana (VIH. Objetivo. Fue determinar la relación entre los resultados serológicos positivos para HHV-8 y el sarcoma de Kaposi en pacientes positivos y negativos para VIH de Medellín, buscando la relación con distintas variables. Materiales y métodos. Es un estudio descriptivo, de cohorte, prospectivo, del suero de 98 pacientes de diferentes instituciones de salud de Medellín, los cuales se dividieron en cuatro grupos para determinar por inmunofluorescencia su seropositividad frente a HHV-8 y poder asociar en forma univariada y bivariada con diferentes variables. Resultados. Se estudiaron 98 sueros. En el grupo de pacientes con sarcoma de Kaposi y VIH, 83,3% fueron positivos para HHV- 8, en el grupo sin sarcoma de Kaposi pero con sífilis, 20,8% fueron positivos para HHV-8, en el grupo sin sarcoma de Kaposi pero VIH positivos, 8% fueron positivos para HHV-8 y en el grupo de sueros de banco de sangre, 4% fueron positivos para HHV-8. La presencia de sarcoma de Kaposi no tuvo relación con la evolución de la enfermedad por VIH ni con el recuento de CD4/ml. Conclusiones. El HHV-8 circula en nuestro medio y existe una relación entre la infección por este virus y el desarrollo de sarcoma de Kaposi, especialmente en pacientes con enfermedades de transmisión sexual y VIH positivos.Background: Apparently, there is a relationship between human Herpesvirus 8 (HHV-8 infection and Kaposi´ sarcoma, especially in HIV-positive population. Objectives: To define the relationship between seropositivity against HHV- 8 and Kaposi´ sarcoma in an HIV positive and negative population from Medellín, looking for its relationship with different variables. Methods: It is a descriptive, cohort, prospective study which

Bafômetro positivo: correlatos do comportamento de beber e dirigir na cidade de Belo Horizonte, Minas Gerais, Brasil Alcoholímetro positivo: interrelación entre la conducta de beber y conducir en la ciudad de Belo Horizonte, Minas Gerais, Brasil Positive breathalyzer test: factors associated with drinking and driving in the city of Belo Horizonte, Minas Gerais State, Brazil

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Valdir Ribeiro Campos

2013-01-01

Full Text Available As características dos condutores que adotam o comportamento do beber e dirigir ainda não foram bem estudadas no país. O presente estudo apresenta dados da prevalência e características dos motoristas sob a influência de álcool nas nove regionais da cidade de Belo Horizonte, Minas Gerais, Brasil. Foram entrevistados 1.656 condutores. Desses, 1.254 (76% aceitaram responder a um questionário estruturado e fazer o teste do bafômetro. O teste do bafômetro foi positivo para 15% dos condutores. O modelo de regressão logística prediz bafômetro positivo com chance 1,5 vez maior para os condutores com idade acima de 31 anos e 4,5 vezes maior para quem tem frequência de consumo de álcool pelo menos semanal. Além disso, condutores da regional Barreiro tem 2 vezes mais chances de apresentarem bafômetro positivo. Estudos localizados com metodologia dos postos de checagem da sobriedade podem monitorar o comportamento e características dos condutores, riscos no trânsito e direcionar políticas públicas para o beber e dirigir.Las características de los conductores que adoptan la conducta de beber y conducir todavía no han sido bien estudiadas en el país. El presente estudio muestra datos de la prevalencia y características de los conductores bajo la influencia de alcohol en las nueve carreteras regionales de la ciudad de Belo Horizonte, Minas Gerais, Brasil. Se entrevistaron a 1.656 conductores. De ellos, 1.254 (76% aceptaron responder a un cuestionario estructurado y hacer el test del alcoholímetro. El test del alcoholímetro fue positivo para un 15% de los conductores. El modelo de regresión logística predice un alcoholímetro positivo con una probabilidad 1,5 vez mayor para los conductores de edad por encima de los 31 años y 4,5 veces mayor para quien tiene una frecuencia de consumo de alcohol por lo menos semanal. Asimismo, conductores de la regional Barreiro tienen 2 veces más probabilidad de presentar positivo en el alcohol

Histiocytic necrotizing lymphadenitis (Kikuchi lymphadenitis in an HIV-positive patient Linfadenite necrosante histiocítica (linfadenite de Kikuchi em um paciente HIV-positivo

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José VASSALLO

2002-10-01

Full Text Available Histiocytic necrotizing lymphadenitis, or Kikuchi's lymphadenitis (KL, is an unusual form of lymphadenitis, generally with self-limited clinical course. KL has been reported in rare patients infected with the human immunodeficiency virus (HIV. Pathogenesis of the lesion is probably related to an impaired immune function. The purpose of the present article is to report on one case in which KL was diagnosed in an HIV-infected patient. Histomorphology and immunophenotype were similar to previous reports, but a focus of activated CD30+ macrophages was seen, what might be due to the immunological status of the patient. EBV was not detected on the sections using the in situ hybridization technique. Although rare, the occurrence of KL in HIV-infected subjects must be emphasized, because of the potential misdiagnosis of malignancy, especially in the presence of CD30+ cells.A linfadenite necrosante histiocítica, ou linfadenite de Kikuchi (LK, é uma forma rara de linfadenite, geralmente de curso clínico auto-limitado. Raros casos de LK associados à infecção pelo vírus da imunodeficiência humana (HIV foram relatados, sendo sua patogênese atribuída à disfunção imunológica destes pacientes. O objetivo do presente artigo é relatar um caso de associação de LK em um paciente HIV-positivo. A histomorfologia e a imunofenotipagem foram semelhantes aos casos anteriormente descritos na literatura, mas focos de macrófagos ativados positivos para o CD30 foram vistos, o que pode ser devido ao estado imune do paciente. A pesquisa de EBV por hibridização in situ foi negativa no tecido. Embora rara, a ocorrência de LK em pacientes HIV-positivos deve ser lembrada, por causa do potencial erro diagnóstico com linfoma maligno, especialmente na presença de células CD30+.

RNases and Helicases in Gram-Positive Bacteria.

Science.gov (United States)

Durand, Sylvain; Condon, Ciaran

2018-04-01

RNases are key enzymes involved in RNA maturation and degradation. Although they play a crucial role in all domains of life, bacteria, archaea, and eukaryotes have evolved with their own sets of RNases and proteins modulating their activities. In bacteria, these enzymes allow modulation of gene expression to adapt to rapidly changing environments. Today, >20 RNases have been identified in both Escherichia coli and Bacillus subtilis , the paradigms of the Gram-negative and Gram-positive bacteria, respectively. However, only a handful of these enzymes are common to these two organisms and some of them are essential to only one. Moreover, although sets of RNases can be very similar in closely related bacteria such as the Firmicutes Staphylococcus aureus and B. subtilis , the relative importance of individual enzymes in posttranscriptional regulation in these organisms varies. In this review, we detail the role of the main RNases involved in RNA maturation and degradation in Gram-positive bacteria, with an emphasis on the roles of RNase J1, RNase III, and RNase Y. We also discuss how other proteins such as helicases can modulate the RNA-degradation activities of these enzymes.

Selenoproteins in Archaea and Gram-positive bacteria.

Science.gov (United States)

Stock, Tilmann; Rother, Michael

2009-11-01

Selenium is an essential trace element for many organisms by serving important catalytic roles in the form of the 21st co-translationally inserted amino acid selenocysteine. It is mostly found in redox-active proteins in members of all three domains of life and analysis of the ever-increasing number of genome sequences has facilitated identification of the encoded selenoproteins. Available data from biochemical, sequence, and structure analyses indicate that Gram-positive bacteria synthesize and incorporate selenocysteine via the same pathway as enterobacteria. However, recent in vivo studies indicate that selenocysteine-decoding is much less stringent in Gram-positive bacteria than in Escherichia coli. For years, knowledge about the pathway of selenocysteine synthesis in Archaea and Eukarya was only fragmentary, but genetic and biochemical studies guided by analysis of genome sequences of Sec-encoding archaea has not only led to the characterization of the pathways but has also shown that they are principally identical. This review summarizes current knowledge about the metabolic pathways of Archaea and Gram-positive bacteria where selenium is involved, about the known selenoproteins, and about the respective pathways employed in selenoprotein synthesis.

EFFECT OF SILICATE ON GRAM STAINING AND VIABILITY OF PNEUMOCOCCI AND OTHER BACTERIA

Science.gov (United States)

MacLeod, Colin M.; Roe, Amy S.

1956-01-01

Application of silicate solutions to living or heat-killed pneumococci and to certain "viridans" streptococci causes their conversion from a Gram-positive to a Gram-negative state. The original staining properties can be restored by suspending the silicate-treated bacteria in alkaline solutions of various salts but not by simple washing in water. Living pneumococci and the strains of streptococci whose staining properties are similarly affected are killed when suspended in silicate solutions. In other Gram-positive species silicate causes conversion to Gram negativity but restoration to positivity occurs upon washing in water. In a third group of Gram-positive organisms silicate has no effect on the Gram reaction. The viability of organisms in these two groups is unaffected by silicate under the conditions employed. No effect on staining or viability of Gram-negative bacteria has been observed. The effects of silicate on staining and viability are inhibited by nutrient broth or whole serum but not by purified serum albumin. Lecithin, choline, and other substituted ammonium compounds also inhibit the effects of silicate on pneumococci. PMID:13306854

Use of magnetic beads for Gram staining of bacteria in aqueous suspension.

Science.gov (United States)

Yazdankhah, S P; Sørum, H; Larsen, H J; Gogstad, G

2001-12-01

A Gram staining technique was developed using monodisperse magnetic beads in concentrating bacteria in suspension for downstream application. The technique does not require heat fixation of organisms, electrical power, or a microscope. Gram-negative and Gram-positive bacteria were identified macroscopically based on the colour of the suspension. The bacteria concentrated on magnetic beads may also be identified microscopically.

Space Efficient Data Structures for N-gram Retrieval

Directory of Open Access Journals (Sweden)

Fotios Kounelis

2017-10-01

Full Text Available A significant problem in computer science is the management of large data strings and a great number of works dealing with the specific problem has been published in the scientific literature. In this article, we use a technique to store efficiently biological sequences, making use of data structures like suffix trees and inverted files and also employing techniques like n-grams, in order to improve previous constructions. In our attempt, we drastically reduce the space needed to store the inverted indexes, by representing the substrings that appear more frequently in a more compact inverted index. Our technique is based on n-gram indexing, providing us the extra advantage of indexing sequences that cannot be separated in words. Moreover, our technique combines classical one level with two-level n-gram inverted file indexing. Our results suggest that the new proposed algorithm can compress the data more efficiently than previous attempts.

Horse gram- an underutilized nutraceutical pulse crop: a review.

Science.gov (United States)

Prasad, Saroj Kumar; Singh, Manoj Kumar

2015-05-01

Horse gram is an underutilized pulse crop grown in wide range of adverse climatic conditions. It occupies an important place in human nutrition and has rich source of protein, minerals, and vitamins. Besides nutritional importance, it has been linked to reduced risk of various diseases due to presence of non-nutritive bioactive substances. These bioactive substances such as phytic acid, phenolic acid, fiber, enzymatic/proteinase inhibitors have significant metabolic and/or physiological effects. The importance of horse gram was well recognized by the folk/alternative/traditional medicine as a potential therapeutic agent to treat kidney stones, urinary diseases, piles, common cold, throat infection, fever etc. The inception of nutraceutical concept and increasing health consciousness the demand of nutraceutical and functional food is increased. In recent years, isolation and utilization of potential antioxidants from legumes including horse gram are increased as it decreases the risk of intestinal diseases, diabetes, coronary heart disease, prevention of dental caries etc. Keeping in view the increasing demand of food having nutraceutical values, the present review ascribed with recent scientific knowledge towards the possibilities of exploring the horse gram, as a source of food and nutraceuticals compounds.

Genetic diversity in green gram accessions as revealed by STMS ...

African Journals Online (AJOL)

Molecular characterization of green gram (Vigna radiata (L.) Wilczek) germplasm is essential for scientific assessment of variability and diversity for its better utilization in breeding programs. In this study, 120 accessions of green gram were analysed for 27 Sequence Tagged Microsatellites (STMS) loci. For data analysis ...

Gram-typing of mastitis bacteria in milk samples using flow cytometry

DEFF Research Database (Denmark)

Langerhuus, Sine Nygaard; Ingvartsen, Klaus Lønne; Bennedsgaard, Torben Werner

2013-01-01

Fast identification of pathogenic bacteria in milk samples from cows with clinical mastitis is central to proper treatment. In Denmark, time to bacterial diagnosis is typically 24 to 48 h when using traditional culturing methods. The PCR technique provides a faster and highly sensitive identifica......Fast identification of pathogenic bacteria in milk samples from cows with clinical mastitis is central to proper treatment. In Denmark, time to bacterial diagnosis is typically 24 to 48 h when using traditional culturing methods. The PCR technique provides a faster and highly sensitive...... cytometry-based method, which can detect and distinguish gram-negative and gram-positive bacteria in mastitis milk samples. The differentiation was based on bacterial fluorescence intensities upon labeling with biotin-conjugated wheat germ agglutinin and acridine orange. Initially 19 in-house bacterial...... characteristic curves for the 19 bacterial cultures. The method was then tested on 53 selected mastitis cases obtained from the department biobank (milk samples from 6 gram-negative and 47 gram-positive mastitis cases). Gram-negative bacteria in milk samples were detected with a sensitivity of 1...

Rapid and reliable identification of Gram-negative bacteria and Gram-positive cocci by deposition of bacteria harvested from blood cultures onto the MALDI-TOF plate.

Science.gov (United States)

Barnini, Simona; Ghelardi, Emilia; Brucculeri, Veronica; Morici, Paola; Lupetti, Antonella

2015-06-18

Rapid identification of the causative agent(s) of bloodstream infections using the matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) methodology can lead to increased empirical antimicrobial therapy appropriateness. Herein, we aimed at establishing an easier and simpler method, further referred to as the direct method, using bacteria harvested by serum separator tubes from positive blood cultures and placed onto the polished steel target plate for rapid identification by MALDI-TOF. The results by the direct method were compared with those obtained by MALDI-TOF on bacteria isolated on solid media. Identification of Gram-negative bacilli was 100 % concordant using the direct method or MALDI-TOF on isolated bacteria (96 % with score > 2.0). These two methods were 90 % concordant on Gram-positive cocci (32 % with score > 2.0). Identification by the SepsiTyper method of Gram-positive cocci gave concordant results with MALDI-TOF on isolated bacteria in 87 % of cases (37 % with score > 2.0). The direct method herein developed allows rapid identification (within 30 min) of Gram-negative bacteria and Gram-positive cocci from positive blood cultures and can be used to rapidly report reliable and accurate results, without requiring skilled personnel or the use of expensive kits.

A prospective study of the diagnostic utility of sputum Gram stain in pneumonia.

Science.gov (United States)

Anevlavis, Stavros; Petroglou, Niki; Tzavaras, Athanasios; Maltezos, Efstratios; Pneumatikos, Ioannis; Froudarakis, Marios; Anevlavis, Eleftherios; Bouros, Demosthenes

2009-08-01

Sputum Gram stain and culture have been said to be unreliable indicators of the microbiological diagnosis of bacterial pneumonia. The etiological diagnosis of pneumonia is surrounded by great degree of uncertainty. This uncertainty should be and can be calculated and incorporated in the diagnosis and treatment. To determine the diagnostic accuracy and diagnostic value of sputum Gram stain in etiological diagnosis and initial selection of antimicrobial therapy of bacterial community acquired pneumonia (CAP). DESIGN-METHOD: Prospective study of 1390 patients with CAP admitted January 2002-June 2008, to our institutions. Of the 1390 patients, 178 (12.8%) fulfilled the criteria for inclusion into this study (good-quality sputa and presence of the same microorganism in blood and sputum cultures which was used as gold standard for assessing the diagnostic accuracy and diagnostic value of sputum Gram stain). The sensitivity of sputum Gram stain was 0.82 for Pneumococcal pneumonia, 0.76 for Staphylococcal pneumonia, 0.79 for Haemophilus influenzae pneumonia and 0.78 for Gram-negative bacilli pneumonia. The specificity of sputum Gram stain was 0.93 for Pneumococcal pneumonia, 0.96 for Staphylococcal pneumonia, 0.96 for H. influenzae pneumonia and 0.95 for Gram-negative bacilli pneumonia. The positive likelihood ratio (LR+) was 11.58 for Pneumococcal pneumonia, 19.38 for Staphylococcal pneumonia, 16.84 for H. influenzae pneumonia, 14.26 for Gram-negative bacilli pneumonia. The negative likelihood ratio (LR-) was 0.20 for Pneumococcal pneumonia, 0.25 for Staphylococcal pneumonia, 0.22 for H. influenzae pneumonia, and 0.23 for Gram-negative bacilli pneumonia. Sputum Gram stain is a dependable diagnostic test for the early etiological diagnosis of bacterial CAP that helps in choosing orthological and appropriate initial antimicrobial therapy.

Bacteriemia por Campylobacter fetus aislado mediante métodos convencionales de una paciente inmunocomprometida Bacteremia due to Campylobacter fetus isolated by conventional methods from an immunocompromised patient

Directory of Open Access Journals (Sweden)

G. Epifane

2007-03-01

Full Text Available Las bacterias del género Campylobacter son bacilos gram-negativos móviles, helicoidales, que presentan morfologías características. Estos microorganismos requieren una baja tensión de oxígeno y un nivel aumentado de CO2 para su desarrollo. Se presenta un caso de bacteriemia por Campylobacter fetus en una paciente con diagnóstico previo de cáncer de mama, metástasis en columna dorso-lumbar y leucemia promielocítica aguda M3 variante de la clasificación FAB. La paciente ingresó al Hospital Italiano de Córdoba por pérdida de conocimiento y proctorragia de 48 h de evolución. Debido a su pancitopenia severa se le realizaron sucesivas transfusiones de sangre. A los 13 días de internación presentó fiebre permanente. Se tomaron muestras para hemocultivo y urocultivo y se comenzó el tratamiento antibiótico con clindamicina y ciprofloxacina. Los hemocultivos se subcultivaron a las 48 h en agar chocolate. A las 24 h de incubación a 35 °C en atmósfera con 5% de CO2 desarrollaron colonias diminutas. La coloración de Gram reveló en ambas muestras bacilos gram-negativos espirilados, posteriormente identificados como Campylobacter fetus por medio de pruebas bioquímicas convencionales. El esquema antibiótico fue rotado a gentamicina más clindamicina. La paciente evolucionó favorablemente y los hemocultivos resultaron negativos luego de 5 días de tratamiento.The genus Campylobacter includes gram-negative, motile, curved rods that can evidence characteristic morphologies. These microorganisms require low oxygen tension and an increased level of CO2 for growing. A case of bacteremia due to Campylobacter fetus in a patient with a previous diagnosis of breast cancer with metastases in dorso-lumbar column and acute promyelocytic leukemia (FAB-M3 variant is presented. The patient was admitted to our institution due to loss of consciousness and a 2 day - history of bloody diarrhea. She received successive blood transfusions on account of

Higher order structure in the 3'-minor domain of small subunit ribosomal RNAs from a gram negative bacterium, a gram positive bacterium and a eukaryote

DEFF Research Database (Denmark)

Douthwaite, S; Christensen, A; Garrett, R A

1983-01-01

of additional higher order structure in the renatured free RNA. It can be concluded that a high level of conservation of higher order structure has occurred during the evolution of the gram negative and gram positive eubacteria and the eukaryote in both the double helical regions and the "unstructured" regions...

Bio sorption of some Rare Earth Elements and Yttrium by Gram Positive and Gram Negative Bacteria

International Nuclear Information System (INIS)

Ibrahim, H.A.

2012-01-01

The separate bio sorption of the REEs La, Sm, Eu and Dy together with yttrium upon the Gram positive bacteria Bacillus subtilis (B.subtilis) and Bacillus Licheniformis (B. Licheniformis),the Gram negative bacterium Escherichia coli (E. coli ) and Saccharomyces cervisiae (Yeast) was studied. The revelant factors of ph 1-6, contact time (30-180 min), the initial rare earth concentration (50-200 mg/l) have been studied. The amount of the accumulated element was strongly affected by its concentration.In addition, bio sorptive fractionation of Y and the studied REEs from a solution containing a mixture of these elements was also studied. From the obtained data, it was found that Langmuir isotherm model for both B.licheniformis and E.coli gives a best fit for the studied elements over the working range of concentration (50-200 mg/I). Transmission electron microscopy exhibited accumulation throughout the bacterial cell with some granular deposits in both the cell periphery and cytoplasm

Clinical utility of an automated instrument for gram staining single slides.

Science.gov (United States)

Baron, Ellen Jo; Mix, Samantha; Moradi, Wais

2010-06-01

Gram stains of 87 different clinical samples were prepared by the laboratory's conventional methods (automated or manual) and by a new single-slide-type automated staining instrument, GG&B AGS-1000. Gram stains from either heat- or methanol-fixed slides stained with the new instrument were easy to interpret, and results were essentially the same as those from the methanol-fixed slides prepared as a part of the routine workflow. This instrument is well suited to a rapid-response laboratory where Gram stain requests are commonly received on a stat basis.

Mining for constructions in texts using N-gram and network analysis

DEFF Research Database (Denmark)

Shibuya, Yoshikata; Jensen, Kim Ebensgaard

2015-01-01

N-gram analysis to Lewis Carroll's novel Alice's Adventures in Wonderland and Mark Twain's novelThe Adventures of Huckleberry Finn and extrapolate a number of likely constructional phenomena from recurring N-gram patterns in the two texts. In addition to simple N-gram analysis, the following....... The main premise is that, if constructions are functional units, then configurations of words that tend to recur together in discourse are likely to have some sort of function that speakers utilize in discourse. Writers of fiction, for instance, may use constructions in characterizations, mind-styles, text...

Efficient n-gram, Skipgram and Flexgram Modelling with Colibri Core

Directory of Open Access Journals (Sweden)

Maarten van Gompel

2016-08-01

Full Text Available Counting n-grams lies at the core of any frequentist corpus analysis and is often considered a trivial matter. Going beyond consecutive n-grams to patterns such as skipgrams and flexgrams increases the demand for efficient solutions. The need to operate on big corpus data does so even more. Lossless compression and non-trivial algorithms are needed to lower the memory demands, yet retain good speed. Colibri Core is software for the efficient computation and querying of n-grams, skipgrams and flexgrams from corpus data. The resulting pattern models can be analysed and compared in various ways. The software offers a programming library for C++ and Python, as well as command-line tools.

Revisiting the gram-negative lipoprotein paradigm

Science.gov (United States)

The processing of lipoproteins (lpps) in Gram-negative bacteria is generally considered to be an essential pathway. Mature lipoproteins in these bacteria are triacylated, with the final fatty acid addition performed by Lnt, an apolipoprotein n-acyltransferase. The mature lipoproteins are then sorted...

The Toll pathway underlies host sexual dimorphism in resistance to both Gram-negative and Gram-positive bacteria in mated Drosophila.

Science.gov (United States)

Duneau, David F; Kondolf, Hannah C; Im, Joo Hyun; Ortiz, Gerardo A; Chow, Christopher; Fox, Michael A; Eugénio, Ana T; Revah, J; Buchon, Nicolas; Lazzaro, Brian P

2017-12-21

Host sexual dimorphism is being increasingly recognized to generate strong differences in the outcome of infectious disease, but the mechanisms underlying immunological differences between males and females remain poorly characterized. Here, we used Drosophila melanogaster to assess and dissect sexual dimorphism in the innate response to systemic bacterial infection. We demonstrated sexual dimorphism in susceptibility to infection by a broad spectrum of Gram-positive and Gram-negative bacteria. We found that both virgin and mated females are more susceptible than mated males to most, but not all, infections. We investigated in more detail the lower resistance of females to infection with Providencia rettgeri, a Gram-negative bacterium that naturally infects D. melanogaster. We found that females have a higher number of phagocytes than males and that ablation of hemocytes does not eliminate the dimorphism in resistance to P. rettgeri, so the observed dimorphism does not stem from differences in the cellular response. The Imd pathway is critical for the production of antimicrobial peptides in response to Gram-negative bacteria, but mutants for Imd signaling continued to exhibit dimorphism even though both sexes showed strongly reduced resistance. Instead, we found that the Toll pathway is responsible for the dimorphism in resistance. The Toll pathway is dimorphic in genome-wide constitutive gene expression and in induced response to infection. Toll signaling is dimorphic in both constitutive signaling and in induced activation in response to P. rettgeri infection. The dimorphism in pathway activation can be specifically attributed to Persephone-mediated immune stimulation, by which the Toll pathway is triggered in response to pathogen-derived virulence factors. We additionally found that, in absence of Toll signaling, males become more susceptible than females to the Gram-positive Enterococcus faecalis. This reversal in susceptibility between male and female Toll

Incidence of carbapenem-resistant gram negatives in Italian transplant recipients: a nationwide surveillance study.

Science.gov (United States)

Lanini, Simone; Costa, Alessandro Nanni; Puro, Vincenzo; Procaccio, Francesco; Grossi, Paolo Antonio; Vespasiano, Francesca; Ricci, Andrea; Vesconi, Sergio; Ison, Michael G; Carmeli, Yehuda; Ippolito, Giuseppe

2015-01-01

Bacterial infections remain a challenge to solid organ transplantation. Due to the alarming spread of carbapenem-resistant gram negative bacteria, these organisms have been frequently recognized as cause of severe infections in solid organ transplant recipients. Between 15 May and 30 September 2012 we enrolled 887 solid organ transplant recipients in Italy with the aim to describe the epidemiology of gram negative bacteria spreading, to explore potential risk factors and to assess the effect of early isolation of gram negative bacteria on recipients' mortality during the first 90 days after transplantation. During the study period 185 clinical isolates of gram negative bacteria were reported, for an incidence of 2.39 per 1000 recipient-days. Positive cultures for gram negative bacteria occurred early after transplantation (median time 26 days; incidence rate 4.33, 1.67 and 1.14 per 1,000 recipient-days in the first, second and third month after SOT, respectively). Forty-nine of these clinical isolates were due to carbapenem-resistant gram negative bacteria (26.5%; incidence 0.63 per 1000 recipient-days). Carbapenems resistance was particularly frequent among Klebsiella spp. isolates (49.1%). Recipients with longer hospital stay and those who received either heart or lung graft were at the highest risk of testing positive for any gram negative bacteria. Moreover recipients with longer hospital stay, lung recipients and those admitted to hospital for more than 48h before transplantation had the highest probability to have culture(s) positive for carbapenem-resistant gram negative bacteria. Forty-four organ recipients died (0.57 per 1000 recipient-days) during the study period. Recipients with at least one positive culture for carbapenem-resistant gram negative bacteria had a 10.23-fold higher mortality rate than those who did not. The isolation of gram-negative bacteria is most frequent among recipient with hospital stays >48 hours prior to transplant and in those

Incidence of carbapenem-resistant gram negatives in Italian transplant recipients: a nationwide surveillance study.

Directory of Open Access Journals (Sweden)

Simone Lanini

Full Text Available Bacterial infections remain a challenge to solid organ transplantation. Due to the alarming spread of carbapenem-resistant gram negative bacteria, these organisms have been frequently recognized as cause of severe infections in solid organ transplant recipients.Between 15 May and 30 September 2012 we enrolled 887 solid organ transplant recipients in Italy with the aim to describe the epidemiology of gram negative bacteria spreading, to explore potential risk factors and to assess the effect of early isolation of gram negative bacteria on recipients' mortality during the first 90 days after transplantation. During the study period 185 clinical isolates of gram negative bacteria were reported, for an incidence of 2.39 per 1000 recipient-days. Positive cultures for gram negative bacteria occurred early after transplantation (median time 26 days; incidence rate 4.33, 1.67 and 1.14 per 1,000 recipient-days in the first, second and third month after SOT, respectively. Forty-nine of these clinical isolates were due to carbapenem-resistant gram negative bacteria (26.5%; incidence 0.63 per 1000 recipient-days. Carbapenems resistance was particularly frequent among Klebsiella spp. isolates (49.1%. Recipients with longer hospital stay and those who received either heart or lung graft were at the highest risk of testing positive for any gram negative bacteria. Moreover recipients with longer hospital stay, lung recipients and those admitted to hospital for more than 48h before transplantation had the highest probability to have culture(s positive for carbapenem-resistant gram negative bacteria. Forty-four organ recipients died (0.57 per 1000 recipient-days during the study period. Recipients with at least one positive culture for carbapenem-resistant gram negative bacteria had a 10.23-fold higher mortality rate than those who did not.The isolation of gram-negative bacteria is most frequent among recipient with hospital stays >48 hours prior to transplant

Gram negative wound infection in hospitalised adult burn patients--systematic review and metanalysis-.

Science.gov (United States)

Azzopardi, Ernest A; Azzopardi, Elayne; Camilleri, Liberato; Villapalos, Jorge; Boyce, Dean E; Dziewulski, Peter; Dickson, William A; Whitaker, Iain S

2014-01-01

Gram negative infection is a major determinant of morbidity and survival. Traditional teaching suggests that burn wound infections in different centres are caused by differing sets of causative organisms. This study established whether Gram-negative burn wound isolates associated to clinical wound infection differ between burn centres. Studies investigating adult hospitalised patients (2000-2010) were critically appraised and qualified to a levels of evidence hierarchy. The contribution of bacterial pathogen type, and burn centre to the variance in standardised incidence of Gram-negative burn wound infection was analysed using two-way analysis of variance. Pseudomonas aeruginosa, Klebsiella pneumoniae, Acinetobacter baumanni, Enterobacter spp., Proteus spp. and Escherichia coli emerged as the commonest Gram-negative burn wound pathogens. Individual pathogens' incidence did not differ significantly between burn centres (F (4, 20) = 1.1, p = 0.3797; r2 = 9.84). Gram-negative infections predominate in burn surgery. This study is the first to establish that burn wound infections do not differ significantly between burn centres. It is the first study to report the pathogens responsible for the majority of Gram-negative infections in these patients. Whilst burn wound infection is not exclusive to these bacteria, it is hoped that reporting the presence of this group of common Gram-negative "target organisms" facilitate clinical practice and target research towards a defined clinical demand.

Utility of gram staining for evaluation of the quality of cystic fibrosis sputum samples.

Science.gov (United States)

Nair, Bindu; Stapp, Jenny; Stapp, Lynn; Bugni, Linda; Van Dalfsen, Jill; Burns, Jane L

2002-08-01

The microscopic examination of Gram-stained sputum specimens is very helpful in the evaluation of patients with community-acquired pneumonia and has also been recommended for use in cystic fibrosis (CF) patients. This study was undertaken to evaluate that recommendation. One hundred one sputum samples from CF patients were cultured for gram-negative bacilli and examined by Gram staining for both sputum adequacy (using the quality [Q] score) and bacterial morphology. Subjective evaluation of adequacy was also performed and categorized. Based on Q score evaluation, 41% of the samples would have been rejected despite a subjective appearance of purulence. Only three of these rejected samples were culture negative for gram-negative CF pathogens. Correlation between culture results and quantitative Gram stain examination was also poor. These data suggest that subjective evaluation combined with comprehensive bacteriology is superior to Gram staining in identifying pathogens in CF sputum.

Improving Gram stain proficiency in hospital and satellite laboratories that do not have microbiology.

Science.gov (United States)

Guarner, Jeannette; Street, Cassandra; Matlock, Margaret; Cole, Lisa; Brierre, Francoise

2017-03-01

Consolidation of laboratories has left many hospitals and satellite laboratories with minimal microbiologic testing. In many hospitals and satellite laboratories, Gram stains on primary specimens are still performed despite difficultly in maintaining proficiency. To maintain Gram stain proficiency at a community 450-bed hospital with an active emergency room we designed bimonthly challenges that require reporting Gram staining and morphology of different organisms. The challenges consist of five specimens prepared by the reference microbiology laboratory from cultures and primary specimens. Twenty to 23 medical laboratory scientists participate reading the challenges. Results from the challenges are discussed with each medical laboratory scientists. In addition, printed images from the challenges are presented at huddle to add microbiology knowledge. On the first three challenges, Gram staining was read correctly in 71%-77% of the time while morphology 53%-66%. In the last six challenges correct answers for Gram stain were 77%-99% while morphology 73%-96%. We observed statistically significant improvement when reading Gram stains by providing frequent challenges to medical laboratory scientists. The clinical importance of Gram stain results is emphasized during huddle presentations increasing knowledge and motivation to perform the test for patients.

A Comparison of Heat versus Methanol Fixation for Gram Staining Bacteria

Science.gov (United States)

Minnerath, Jeanne M.; Roland, Jenna M.; Rossi, Lucas C.; Weishalla, Steven R.; Wolf, Melissa M.

2009-01-01

Gram staining bacteria is a fundamental technique introduced in general biology and microbiology laboratory courses. Two common problems students encounter when Gram staining bacteria are (1) having a difficult time locating bacterial cells on the microscope slide and (2) over-decolorizing bacterial cells during the staining procedure such that…

Keywords in Context (Using n-grams with Python

Directory of Open Access Journals (Sweden)

William J. Turkel

2012-07-01

Full Text Available Like in Output Data as HTML File, this lesson takes the frequency pairs collected in Counting Frequencies and outputs them in HTML. This time the focus is on keywords in context (KWIC which creates n-grams from the original document content – in this case a trial transcript from the Old Bailey Online. You can use your program to select a keyword and the computer will output all instances of that keyword, along with the words to the left and right of it, making it easy to see at a glance how the keyword is used. Once the KWICs have been created, they are then wrapped in HTML and sent to the browser where they can be viewed. This reinforces what was learned in Output Data as HTML File, opting for a slightly different output. At the end of this lesson, you will be able to extract all possible n-grams from the text. In the next lesson, you will be learn how to output all of the n-grams of a given keyword in a document downloaded from the Internet, and display them clearly in your browser window.

Risk factors for multidrug-resistant Gram-negative infection in burn patients.

Science.gov (United States)

Vickers, Mark L; Dulhunty, Joel M; Ballard, Emma; Chapman, Paul; Muller, Michael; Roberts, Jason A; Cotta, Menino O

2018-05-01

Infection with multidrug-resistant (MDR) Gram-negative organisms leads to poorer outcomes in the critically ill burn patient. The aim of this study was to identify the risk factors for MDR Gram-negative pathogen infection in critically ill burn patients admitted to a major tertiary referral intensive care unit (ICU) in Australia. A retrospective case-control study of all adult burn patients admitted over a 7-year period was conducted. Twenty-one cases that cultured an MDR Gram-negative organism were matched with 21 controls of similar age, gender, burn size and ICU stay. Multivariable conditional logistic regression was used to individually assess risk factors after adjusting for Acute Burn Severity Index. Adjusted odds ratios (ORs) were reported. P-values negative infection included superficial partial thickness burn size (OR: 1.08; 95% confidence interval (CI): 1.01-1.16; P-value: 0.034), prior meropenem exposure (OR: 10.39; 95% CI: 0.96-112.00; P-value: 0.054), Gram-negative colonization on admission (OR: 9.23; 95% CI: 0.65-130.15; P-value: 0.10) and escharotomy (OR: 2.66; 95% CI: 0.52-13.65; P-value: 0.24). For cases, mean age was 41 (SD: 13) years, mean total body surface area burned was 47% (SD: 18) and mean days in ICU until MDR specimen collection was 17 (SD: 10) days. Prior meropenem exposure, Gram-negative colonization on admission, escharotomy and superficial partial thickness burn size may be potentially important factors for increasing the risk of MDR Gram-negative infection in the critically ill burn patient. © 2017 Royal Australasian College of Surgeons.

Silver-doped manganese dioxide and trioxide nanoparticles inhibit both gram positive and gram negative pathogenic bacteria.

Science.gov (United States)

Kunkalekar, R K; Prabhu, M S; Naik, M M; Salker, A V

2014-01-01

Palladium, ruthenium and silver-doped MnO2 and silver doped Mn2O3 nanoparticles were synthesized by simple co-precipitation technique. SEM-TEM analysis revealed the nano-size of these synthesized samples. XPS data illustrates that Mn is present in 4+ and 3+ oxidation states in MnO2 and Mn2O3 respectively. Thermal analysis gave significant evidence for the phase changes with increasing temperature. Antibacterial activity of these synthesized nanoparticles on three Gram positive bacterial cultures (Staphylococcus aureus ATCC 6538, Streptococcus epidermis ATCC 12228, Bacillus subtilis ATCC 6633) and three Gram negative cultures (Escherichia coli ATCC 8739, Salmonella abony NCTC 6017 and Klebsiella pneumoniae ATCC 1003) was investigated using a disc diffusion method and live/dead assay. Only Ag-doped MnO2 and Ag-doped Mn2O3 nanoparticles showed antibacterial property against all six-test bacteria but Ag-doped MnO2 was found to be more effective than Ag-doped Mn2O3. Copyright © 2013 Elsevier B.V. All rights reserved.

Nanoparticle targeting of Gram-positive and Gram-negative bacteria for magnetic-based separations of bacterial pathogens

Science.gov (United States)

Lu, Hoang D.; Yang, Shirley S.; Wilson, Brian K.; McManus, Simon A.; Chen, Christopher V. H.-H.; Prud'homme, Robert K.

2017-04-01

Antimicrobial resistance is a healthcare problem of increasing significance, and there is increasing interest in developing new tools to address bacterial infections. Bacteria-targeting nanoparticles hold promise to improve drug efficacy, compliance, and safety. In addition, nanoparticles can also be used for novel applications, such as bacterial imaging or bioseperations. We here present the use of a scalable block-copolymer-directed self-assembly process, Flash NanoPrecipitation, to form zinc(II)-bis(dipicolylamine) modified nanoparticles that bind to both Gram-positive and Gram-negative bacteria with specificity. Particles have tunable surface ligand densities that change particle avidity and binding efficacy. A variety of materials can be encapsulated into the core of the particles, such as optical dyes or iron oxide colloids, to produce imageable and magnetically active bacterial targeting constructs. As a proof-of-concept, these particles are used to bind and separate bacteria from solution in a magnetic column. Magnetic manipulation and separation would translate to a platform for pathogen identification or removal. These magnetic and targeted nanoparticles enable new methods to address bacterial infections.

Cystic neutrophilic granulomatous mastitis: an underappreciated pattern strongly associated with gram-positive bacilli.

Science.gov (United States)

Renshaw, Andrew A; Derhagopian, Robert P; Gould, Edwin W

2011-09-01

Although granulomatous lobular mastitis is associated with gram-positive bacilli such as Corynebacterium, this association is not well known. We report 3 cases of mastitis caused by gram-positive bacilli. All 3 abscesses were suppurative with distinct enlarged cystic spaces in which rare gram-positive bacilli were identified. Two cases were also granulomatous. Cultures in all 3 cases were negative. All 3 patients recovered after biopsy and tetracycline-based therapy. Infection in the breast by gram-positive bacilli is associated with a distinct histologic pattern, including cystic spaces in the setting of neutrophilic/granulomatous inflammation that can be recognized and should prompt careful search for the organism within enlarged vacuoles.

Nucleotide sequence alignment of hdcA from Gram-positive bacteria.

Science.gov (United States)

Diaz, Maria; Ladero, Victor; Redruello, Begoña; Sanchez-Llana, Esther; Del Rio, Beatriz; Fernandez, Maria; Martin, Maria Cruz; Alvarez, Miguel A

2016-03-01

The decarboxylation of histidine -carried out mainly by some gram-positive bacteria- yields the toxic dietary biogenic amine histamine (Ladero et al. 2010 〈10.2174/157340110791233256〉 [1], Linares et al. 2016 〈http://dx.doi.org/10.1016/j.foodchem.2015.11.013〉〉 [2]). The reaction is catalyzed by a pyruvoyl-dependent histidine decarboxylase (Linares et al. 2011 〈10.1080/10408398.2011.582813〉 [3]), which is encoded by the gene hdcA. In order to locate conserved regions in the hdcA gene of Gram-positive bacteria, this article provides a nucleotide sequence alignment of all the hdcA sequences from Gram-positive bacteria present in databases. For further utility and discussion, see 〈http://dx.doi.org/ 10.1016/j.foodcont.2015.11.035〉〉 [4].

Extruded black gram flour: Partial substitute for improving quality characteristics of Indian traditional snack

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Laxmi Ananthanarayan

2018-03-01

Full Text Available Background: During extrusion of black gram flour, formation of amylose-lipid complexes lowers down the gelatinization enthalpy of extrudates, and the partially gelatinized black gram starch leads to lowering down the water-holding capacity and alters functional properties resulting in changing quality attributes of the end product on frying/microwaving/roasting. Methods: Attempts have been made to improve the quality of an Indian traditional snack (e.g., papad by incorporating extruded black gram flour as partial substitute for raw (unextruded black gram flour. In present work, overall quality improvement was achieved by analyzing prefrying and postfrying characteristics (diameter, moisture content, expansion ratio, oil uptake, texture, and color of papad and physical properties (color and viscosity of fried oil. Results: Four different papad samples were prepared (control papads without addition of papadkhar, papads with use of 3% papadkhar, papads with incorporation of extruded black gram flour at 25% concentration, papads with incorporation of extruded black gram flour at 50% concentration along with 1% papadkhar and analyzed along standard market sample. Incorporation of extruded black gram flour in papad resulted in greater expansion with less oil uptake in fried papad. Further addition of extruded black gram flour permitted the use of lower concentration of papadkhar. After frying, the quality of oil was characterized after numerous frying cycles. Conclusion: Oil used for frying of papads containing highest concentration of papadkhar was effective only up to two frying cycles, after which color and viscosity increased significantly, adversely affecting the quality of fried oil. Keywords: Black gram flour, Extrusion, Prefrying and postfrying characteristics of papad, Quality of fried oil

Gram stains: a resource for retrospective analysis of bacterial pathogens in clinical studies.

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Srinivasan, Usha; Ponnaluri, Sreelatha; Villareal, Lisa; Gillespie, Brenda; Wen, Ai; Miles, Arianna; Bucholz, Brigette; Marrs, Carl F; Iyer, Ram K; Misra, Dawn; Foxman, Betsy

2012-01-01

We demonstrate the feasibility of using qPCR on DNA extracted from vaginal Gram stain slides to estimate the presence and relative abundance of specific bacterial pathogens. We first tested Gram stained slides spiked with a mix of 10(8) cfu/ml of Escherichia coli and 10(5) cfu/ml of Lactobacillus acidophilus. Primers were designed for amplification of total and species-specific bacterial DNA based on 16S ribosomal gene regions. Sample DNA was pre-amplified with nearly full length 16S rDNA ribosomal gene fragment, followed by quantitative PCR with genera and species-specific 16S rDNA primers. Pre-amplification PCR increased the bacterial amounts; relative proportions of Escherichia coli and Lactobacillus recovered from spiked slides remained unchanged. We applied this method to forty two archived Gram stained slides available from a clinical trial of cerclage in pregnant women at high risk of preterm birth. We found a high correlation between Nugent scores based on bacterial morphology of Lactobacillus, Gardenerella and Mobiluncus and amounts of quantitative PCR estimated genus specific DNA (rrn copies) from Gram stained slides. Testing of a convenience sample of eight paired vaginal swabs and Gram stains freshly collected from healthy women found similar qPCR generated estimates of Lactobacillus proportions from Gram stained slides and vaginal swabs. Archived Gram stained slides collected from large scale epidemiologic and clinical studies represent a valuable, untapped resource for research on the composition of bacterial communities that colonize human mucosal surfaces.

Gram negative wound infection in hospitalised adult burn patients--systematic review and metanalysis-.

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Ernest A Azzopardi

Full Text Available BACKGROUND: Gram negative infection is a major determinant of morbidity and survival. Traditional teaching suggests that burn wound infections in different centres are caused by differing sets of causative organisms. This study established whether Gram-negative burn wound isolates associated to clinical wound infection differ between burn centres. METHODS: Studies investigating adult hospitalised patients (2000-2010 were critically appraised and qualified to a levels of evidence hierarchy. The contribution of bacterial pathogen type, and burn centre to the variance in standardised incidence of Gram-negative burn wound infection was analysed using two-way analysis of variance. PRIMARY FINDINGS: Pseudomonas aeruginosa, Klebsiella pneumoniae, Acinetobacter baumanni, Enterobacter spp., Proteus spp. and Escherichia coli emerged as the commonest Gram-negative burn wound pathogens. Individual pathogens' incidence did not differ significantly between burn centres (F (4, 20 = 1.1, p = 0.3797; r2 = 9.84. INTERPRETATION: Gram-negative infections predominate in burn surgery. This study is the first to establish that burn wound infections do not differ significantly between burn centres. It is the first study to report the pathogens responsible for the majority of Gram-negative infections in these patients. Whilst burn wound infection is not exclusive to these bacteria, it is hoped that reporting the presence of this group of common Gram-negative "target organisms" facilitate clinical practice and target research towards a defined clinical demand.

Bacterias celulolíticas aisladas del intestino de termitas (Nasutitermes nigriceps con características probióticas y potencial en la degradación del pasto

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Cecilia Lara Mantilla

2013-06-01

Full Text Available Título corto: Bacterias celulolíticas aisladas del intestino de termitas (Nasutitermes nigriceps  Título en ingles:  Cellulolytic bacteria isolated from  termites’ gut (Nasutitermes nigriceps with probiotic characteristics and potential pasture degradationResumen: El objetivo de la presente investigación fue aislar bacterias celulolíticas del intestino de termitas (Nasutitermes nigriceps para determinar sus propiedades probióticas in vitro y su potencial en la degradación de pasto. Las termitas fueron tratadas con detergente antibacterial, separando y macerando luego, el intestino de las mismas en agua peptonada estéril. Diluciones de esta mezcla fueron inoculadas en cajas Petri con medio Luria Bertani (LB y Carboximetilcelulosa (CMC al 2%, incubando a 37º C por 24 horas, para luego revelar con Rojo Congo al 1%. Las bacterias que presentaron mayores halos de degradación fueron sometidas a tinción de Gram y a pruebas probióticas de temperatura, pH, salinidad y presencia de sales biliares, así como también a pruebas de antagonismo y degradación de pasto. Los resultados revelaron la presencia de 9 bacilos celulolíticos Gram (- de los cuales, los bacilos BTN7 y BTN8, presentaron los mejores halos de degradación, 12 y 14 mm de diámetro respectivamente, creciendo adecuadamente en las diferentes pruebas probióticas con densidades entre 106 y 108 UFC/ml; el porcentaje de degradación de materia seca fue de 39.73% y 36.10% en 48 y 72 horas respectivamente.  Las pruebas bioquímicas API E (bioMérieux SA revelaron que los bacilos BTN7 y BTN8 pertenecen al género Enterobacter sp. Los anteriores resultados abren la posibilidad de emplear, estos microorganismos como aditivos en la alimentación de rumiantes, a fin de contribuir con un mayor aprovechamiento de pastos, y otros sustratos vegetales lignocelulósicos.Palabras claves: Probióticos, Maralfalfa (Pennisetum sp., microorganismos ruminales, lignocelulosa, Enterobacter

El diagnóstico positivo de autismo infantil

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Juana Velázquez Argota

1996-08-01

Full Text Available Se revisan los límites del síndrome autístico y la evolución del concepto de autismo infantil desde Kanner hasta las clasificaciones psiquiátricas más recientes. Se informan los resultados de nuestras investigaciones en el diagnóstico positivo del autismo infantil. La anamnesis remota es de poco valor, más relevantes para el diagnóstico constituyen el examen del paciente en el presente y las escalas de cuantificación del autismo (las cuales son de utilidad en el diagnóstico diferencial entre el trastorno autístico tipo Kanner y los trastornos autísticos atípicos. Las pruebas de inteligencia standard se deben aplicar según el nivel de funcionamiento del paciente y si no clasificara es más bien por el bajo cociente de inteligencia que por su comportamiento autístico. El clínico debería tener presente la posibilidad del diagnóstico de autismo cuando examina niños pequeños con problemas de desarrollo y utilizar escalas de síntomas autísticos adecuados a los primeros años de vida. Se recomienda el uso de la prueba de Bo Olsson en el diagnóstico diferencial de autismo de Kanner, síndrome de Rett y daño cerebral temprano en la etapa preescolar.The limits of the austistic syndrome as well as the evolution of the infantile autism concept since Kanner to the latest psychiatric classifications are reviewed. The results of our research on the positive diagnosis of infantile autism are reported. The patient's medical examination and the autism quantification scales (useful for the diferential diagnosis between the Kanner type autistic disorder and the atypical autistic disorders are more important for the diagnosis than the remote anamnesis, which is of little value. The standard intelligence test should be applied according to the patients functioning level and if he would not classify it would be because of his low intelligence quotient and not because of his autistic behaviour. The clinician should take into account the

La tuberculosis pulmonar (II)

OpenAIRE

Suñé Ysamat, Bertila

1982-01-01

Los bacilos tuberculosos pueden encontrarse en cantidades importantes en el interior de los macrófagos, o bien en el exterior. El tratamiento médico de la tuberculosis debe conseguir la destrucción de los bacilos intra y extracelulares.

Conjuntivite por Achromobacter xylosoxidans: relato de caso Conjunctivitis due to Achromobacter xylosoxidans: case report

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Juliana Faggion Lucatelli

2009-04-01

Full Text Available Relatamos um caso de conjuntivite ocasionada por Achromobacter xylosoxidans em paciente imunocompetente usuária de lentes de contato rígidas. A bactéria foi isolada da solução utilizada para a desinfecção das lentes bem como do raspado conjuntival. A. xylosoxidans tem sido descrita em infecções oportunistas em pacientes imunodeprimidos, contudo pode ser confundida com outros bacilos gram-negativos, principalmente Pseudomonas aeruginosa, isoladas de infecções oculares em pacientes imunocompetentes. Devido ao reduzido perfil de sensibilidade aos antimicrobianos demonstrado pelo A. xylosoxidans, torna-se importante a identificação deste agente etiológico em quadros de conjuntivite.We report here a case of conjunctivitis in an immunocompetent patient due to Achromobacter xylosoxidans, which was associated with the use of rigid contact lenses. The bacteria were isolated from the scraped conjunctival swab as well as from the lens cleaning fluid. A. xylosoxidans is an opportunistic pathogen, especially in immunocompromised patients; however, in isolates of ocular infections, from immunocompetent patients, it may be confused with other gram-negative organisms, particularly Pseudomonas aeruginosa. Due to an increased resistance against different antimicrobial agents, A. xylosoxidans must be fully identified and differentiated from other gram-negative isolates from ocular infections.

Microbiology of liver abscesses and the predictive value of abscess gram stain and associated blood cultures.

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Chemaly, Roy F; Hall, Gerri S; Keys, Thomas F; Procop, Gary W

2003-08-01

Although rare, pyogenic liver abscesses are potentially fatal. We evaluated the predictive value of Gram stain of liver abscess aspirates and temporally associated blood cultures. Gram stains detected bacteria in 79% of the liver abscesses tested. The sensitivity and specificity of Gram stain of the liver abscesses were 90% and 100% for Gram-positive cocci (GPC) and 52% and 94% for Gram-negative bacilli (GNB). The sensitivities of the blood cultures for any GPC and GNB present in the liver abscess were 30% and 39%, respectively. Although, Gram stains and blood cultures offer incomplete detection of the microbial contents of pyogenic liver abscesses, both tests should always accompany liver abscess cultures.

Clinical Utility of an Automated Instrument for Gram Staining Single Slides ▿

Science.gov (United States)

Baron, Ellen Jo; Mix, Samantha; Moradi, Wais

2010-01-01

Gram stains of 87 different clinical samples were prepared by the laboratory's conventional methods (automated or manual) and by a new single-slide-type automated staining instrument, GG&B AGS-1000. Gram stains from either heat- or methanol-fixed slides stained with the new instrument were easy to interpret, and results were essentially the same as those from the methanol-fixed slides prepared as a part of the routine workflow. This instrument is well suited to a rapid-response laboratory where Gram stain requests are commonly received on a stat basis. PMID:20410348

One Small Step for the Gram Stain, One Giant Leap for Clinical Microbiology.

Science.gov (United States)

Thomson, Richard B

2016-06-01

The Gram stain is one of the most commonly performed tests in the clinical microbiology laboratory, yet it is poorly controlled and lacks standardization. It was once the best rapid test in microbiology, but it is no longer trusted by many clinicians. The publication by Samuel et al. (J. Clin. Microbiol. 54:1442-1447, 2016, http://dx.doi.org/10.1128/JCM.03066-15) is a start for those who want to evaluate and improve Gram stain performance. In an age of emerging rapid molecular results, is the Gram stain still relevant? How should clinical microbiologists respond to the call to reduce Gram stain error rates? Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Combating multidrug-resistant Gram-negative bacterial infections.

Science.gov (United States)

Xu, Ze-Qi; Flavin, Michael T; Flavin, John

2014-02-01

Multidrug-resistant (MDR) bacterial infections, especially those caused by Gram-negative pathogens, have emerged as one of the world's greatest health threats. The development of novel antibiotics to treat MDR Gram-negative bacteria has, however, stagnated over the last half century. This review provides an overview of recent R&D activities in the search for novel antibiotics against MDR Gram-negatives. It provides emphasis in three key areas. First, the article looks at new analogs of existing antibiotic molecules such as β-lactams, tetracyclines, and aminoglycoside as well as agents against novel bacterial targets such as aminoacyl-tRNA synthetase and peptide deformylase. Second, it also examines alternative strategies to conventional approaches including cationic antimicrobial peptides, siderophores, efflux pump inhibitors, therapeutic antibodies, and renewed interest in abandoned treatments or those with limited indications. Third, the authors aim to provide an update on the current clinical development status for each drug candidate. The traditional analog approach is insufficient to meet the formidable challenge brought forth by MDR superbugs. With the disappointing results of the genomics approach for delivering novel targets and drug candidates, alternative strategies to permeate the bacterial cell membrane, enhance influx, disrupt efflux, and target specific pathogens via therapeutic antibodies are attractive and promising. Coupled with incentivized business models, governmental policies, and a clarified regulatory pathway, it is hoped that the antibiotic pipeline will be filled with an effective armamentarium to safeguard global health.

LexGram - a practical categorial grammar formalism -

OpenAIRE

Koenig, Esther

1995-01-01

We present the LexGram system, an amalgam of (Lambek) categorial grammar and Head Driven Phrase Structure Grammar (HPSG), and show that the grammar formalism it implements is a well-structured and useful tool for actual grammar development.

Volatile metabolites from some gram-negative bacteria

DEFF Research Database (Denmark)

Schöller, Charlotte; Molin, Søren; Wilkins, Ken

1997-01-01

A survey of volatile organic compounds (VOCs) excreted from various Gram-negative bacteria (Pseudomonas spp., Serratia spp. and Enterobacter spp.) was carried out. Compounds were identified by gas chromatography-mass spectrometry. VOCs identified included dimethyl disulphide, dimethyl trisulphide...

Multiplex identification of sepsis-causing Gram-negative pathogens from the plasma of infected blood.

Science.gov (United States)

Chung, Boram; Park, Chulmin; Cho, Sung-Yeon; Shin, Juyoun; Shin, Sun; Yim, Seon-Hee; Lee, Dong-Gun; Chung, Yeun-Jung

2018-02-01

Early and accurate detection of bacterial pathogens in the blood is the most crucial step for sepsis management. Gram-negative bacteria are the most common organisms causing severe sepsis and responsible for high morbidity and mortality. We aimed to develop a method for rapid multiplex identification of clinically important Gram-negative pathogens and also validated whether our system can identify Gram-negative pathogens with the cell-free plasm DNA from infected blood. We designed five MLPA probe sets targeting the genes specific to major Gram-negative pathogens (uidA and lacY for E. coli, ompA for A. baumannii, phoE for K. pneumoniae, and ecfX for P. aeruginosa) and one set targeting the CTX-M group 1 to identify the ESBL producing Gram-negative pathogens. All six target-specific peaks were clearly separated without any non-specific peaks in a multiplex reaction condition. The minimum detection limit was 100 fg of pathogen DNA. When we tested 28 Gram-negative clinical isolates, all of them were successfully identified without any non-specific peaks. To evaluate the clinical applicability, we tested seven blood samples from febrile patients. Three blood culture positive cases showed E. coli specific peaks, while no peak was detected in the other four culture negative samples. This technology can be useful for detection of major sepsis-causing, drug-resistant Gram-negative pathogens and also the major ESBL producing Gram-negatives from the blood of sepsis patients in a clinical setting. This system can help early initiation of effective antimicrobial treatment against Gram-negative pathogens for sepsis patients, which is very crucial for better treatment outcomes. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

[Antimicrobial therapy in severe infections with multidrug-resistant Gram-negative bacterias].

Science.gov (United States)

Duszyńska, Wiesława

2010-01-01

Multidrug-resistant Gram-negative bacteria pose a serious and rapidly emerging threat to patients in healthcare settings, and are especially prevalent and problematic in intensive therapy units. Recently, the emergence of pandrug-resistance in Gram-negative bacteria poses additional concerns. This review examines the clinical impact and epidemiology of multidrug-resistant Gram-negative bacteria as a cause of increased morbidity and mortality among ITU patients. Beta-lactamases, cephalosporinases and carbapenemases play the most important role in resistance to antibiotics. Despite the tendency to increased resistance, carbapenems administered by continuous infusion remain the most effective drugs in severe sepsis. Drug concentration monitoring, albeit rarely used in practice, is necessary to ensure an effective therapeutic effect.

Lack of clinical utility of urine gram stain for suspected urinary tract infection in pediatric patients.

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Cantey, Joseph B; Gaviria-Agudelo, Claudia; McElvania TeKippe, Erin; Doern, Christopher D

2015-04-01

Urinary tract infection (UTI) is one of the most common infections in children. Urine culture remains the gold standard for diagnosis, but the utility of urine Gram stain relative to urinalysis (UA) is unclear. We reviewed 312 pediatric patients with suspected UTI who had urine culture, UA, and urine Gram stain performed from a single urine specimen. UA was considered positive if ≥10 leukocytes per oil immersion field were seen or if either nitrates or leukocyte esterase testing was positive. Urine Gram stain was considered positive if any organisms were seen. Sensitivity, specificity, and positive and negative predictive values were calculated using urine culture as the gold standard. Thirty-seven (12%) patients had a culture-proven UTI. Compared to urine Gram stain, UA had equal sensitivity (97.3% versus 97.5%) and higher specificity (85% versus 74%). Empirical therapy was prescribed before the Gram stain result was known in 40 (49%) patients and after in 42 (51%) patients. The antibiotics chosen did not differ between the two groups (P=0.81), nor did they differ for patients with Gram-negative rods on urine Gram stain compared to those with Gram-positive cocci (P=0.67). From these data, we conclude that UA has excellent negative predictive value that is not enhanced by urine Gram stain and that antibiotic selection did not vary based on the urine Gram stain result. In conclusion, the clinical utility of urine Gram stain does not warrant the time or cost it requires. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

DMPD: Cellular reprogramming by gram-positive bacterial components: a review. [Dynamic Macrophage Pathway CSML Database

Lifescience Database Archive (English)

Full Text Available 16885502 Cellular reprogramming by gram-positive bacterial components: a review. Bu...(.csml) Show Cellular reprogramming by gram-positive bacterial components: a review. PubmedID 16885502 Title... Cellular reprogramming by gram-positive bacterial components: a review. Authors

Las normas de aplicación inmediata en la doctrina y en el derecho positivo

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Ruben B. Santos Belandro

2015-10-01

Full Text Available  Al modelo de Estado del siglo XVIII que asumía como únicas funciones la de juez para la solución de los litigios entre los particulares y de gendarme con el objetivo de preservar lapaz pública, le sucedió en los primeros 50 años de nuestro siglo la concepción de un Estado intervencionista -denominado también welfare state o Estado Bienestar- en el que se le otorgó una mayor atención al bienestar de sus habitantes mediante una gestión directa de numerosos sectores de la economía, al privilegio en el desarrollo de aquellas áreas más deprimidas, a la distribución intencional de los recursos sociales en favor de los desprotegidos económicamente, etc (...Contenido: La doctrina.  El derecho positivo. La doctrina uruguaya. 1985-1995. La posición de Uruguay respecto de la liberalización del comercio internacional. La Ronda Uruguay del GATT y la Organización Mundial del Comercio. Conclusiones

In vitro activity of tigecycline and comparator agents against a global collection of Gram-negative and Gram-positive organisms: tigecycline Evaluation and Surveillance Trial 2004 to 2007.

Science.gov (United States)

Garrison, Mark W; Mutters, Reinier; Dowzicky, Michael J

2009-11-01

The Tigecycline Evaluation and Surveillance Trial began in 2004 to monitor the in vitro activity of tigecycline and comparator agents against a global collection of Gram-negative and Gram-positive pathogens. Against Gram negatives (n = 63 699), tigecycline MIC(90)'s ranged from 0.25 to 2 mg/L for Escherichia coli, Haemophilus influenzae, Acinetobacter baumannii, Klebsiella oxytoca, Enterobacter cloacae, Klebsiella pneumoniae, and Serratia marcescens (but was > or =32 for Pseudomonas aeruginosa). Against Gram-positive organisms (n = 32 218), tigecycline MIC(90)'s were between 0.06 and 0.25 mg/L for Streptococcus pneumoniae, Enterococcus faecium, Streptococcus agalactiae, Staphylococcus aureus, and Enterococcus faecalis. The in vitro activity of tigecycline was maintained against resistant phenotypes, including multidrug-resistant A. baumannii (9.2% of isolates), extended-spectrum beta-lactamase-producing E. coli (7.0%) and K. pneumoniae (14.0%), beta-lactamase-producing H. influenzae (22.2%), methicillin-resistant S. aureus (44.5%), vancomycin-resistant E. faecium (45.9%) and E. faecalis (2.8%), and penicillin-resistant S. pneumoniae (13.8%). Tigecycline represents a welcome addition to the armamentarium against difficult to treat organisms.

Textualidad y gramática argumentativa

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RAÚL FIRACATIVE-RUIZ

2014-01-01

Full Text Available La argumentación es un modo de organizar el discurso, cuya orientación se da para lograr el convencimiento del otro. El presente artículo acoge este precepto para abordar la propuesta argumentativa del autor italiano Vincenzo Lo Cascio desde la noción de textualidad . Gramática argumentativa es el nombre dado a esta apuesta teórica y surge de las ideas de la Nueva Retórica de Perelman. Lo Cascio propone la existencia de categorías sintácticas finitas, denominadas reglas categoriales e indicadores de fuerza , las cuales permiten orientar la información de los enunciados y analizar multiplicidad de discursos; por ello, es una teoría que sigue la línea de la sintaxis generativa de Noam Chomsky. El artículo plantea la necesidad de reconocer, desde la Gramática argumentativa, el potencial enunciativo de la palabra en situaciones comunicativas cotidianas, donde es preciso que los enunciadores sean conscientes del uso que hacen de la palabra.

Effect of silver/copper and copper oxide nanoparticle powder on growth of Gram-negative and Gram-positive bacteria and their toxicity against the normal human dermal fibroblasts

International Nuclear Information System (INIS)

Peszke, Jerzy; Nowak, Anna; Szade, Jacek; Szurko, Agnieszka; Zygadło, Dorota; Michałowska, Marlena; Krzyściak, Paweł; Zygoń, Patrycja; Ratuszna, Alicja; Ostafin, Marek M.

2016-01-01

Engineered nanomaterials, especially metallic nanoparticles, are the most popular system applied in daily life products. The study of their biological and toxicity properties seems to be indispensable. In this paper, we present results of biological activity of Ag/Cu nanoparticles. These nanoparticles show more promising killing/inhibiting properties on Gram-negative bacteria than for Gram-positive ones. The Gram-negative bacteria show strong effect already at the concentration of 1 ppm after 15 min of incubation. Moreover, in vitro tests of toxicity made on normal human dermal fibroblast cultures showed that after 72 h of incubation with Ag/Cu nanoparticles, they are less toxic then Cu 2 O/CuO nanoparticles.

Effect of silver/copper and copper oxide nanoparticle powder on growth of Gram-negative and Gram-positive bacteria and their toxicity against the normal human dermal fibroblasts

Energy Technology Data Exchange (ETDEWEB)

Peszke, Jerzy; Nowak, Anna, E-mail: ana.maria.nowak@gmail.com; Szade, Jacek; Szurko, Agnieszka; Zygadło, Dorota; Michałowska, Marlena [University of Silesia, A. Chelkowski Institute of Physics (Poland); Krzyściak, Paweł [Jagiellonian University Medical College, Department of Mycology Chair of Microbiology (Poland); Zygoń, Patrycja [Czestochowa University of Technology, Institute of Materials Engineering (Poland); Ratuszna, Alicja [University of Silesia, A. Chelkowski Institute of Physics (Poland); Ostafin, Marek M. [Department of Microbiology University of Agriculture (Poland)

2016-12-15

Engineered nanomaterials, especially metallic nanoparticles, are the most popular system applied in daily life products. The study of their biological and toxicity properties seems to be indispensable. In this paper, we present results of biological activity of Ag/Cu nanoparticles. These nanoparticles show more promising killing/inhibiting properties on Gram-negative bacteria than for Gram-positive ones. The Gram-negative bacteria show strong effect already at the concentration of 1 ppm after 15 min of incubation. Moreover, in vitro tests of toxicity made on normal human dermal fibroblast cultures showed that after 72 h of incubation with Ag/Cu nanoparticles, they are less toxic then Cu{sub 2}O/CuO nanoparticles.

Comparison of Gram and Kopeloff stains in the diagnosis of bacterial vaginosis in pregnancy.

Science.gov (United States)

Libman, Michael D; Kramer, Michael; Platt, Robert

2006-03-01

Bacterial vaginosis (BV) is commonly diagnosed by using the Nugent score, a semiquantitative scoring system to evaluate bacterial morphotypes on Gram stain of vaginal secretions. Some authors have suggested using the Kopeloff modification of the Gram stain. Asymptomatic BV in pregnancy has been associated with adverse outcomes. We performed both stains on simultaneously collected vaginal smears from 2652 women at 24-26 weeks of gestation. Gram staining gave significantly higher (more abnormal) Nugent scores than Kopeloff staining. Compared to the Kopeloff stain, the number of specimens graded as indeterminate or consistent with BV by Gram stain increased by 29% (469 versus 364, Pstaining was significantly better than Gram staining (agreement=74% versus 63%, intraclass correlation coefficient=0.87 versus 0.79, P<.05, 95% confidence intervals 0.85-0.89 and 0.75-0.82, respectively).

Automated Interpretation of Blood Culture Gram Stains by Use of a Deep Convolutional Neural Network.

Science.gov (United States)

Smith, Kenneth P; Kang, Anthony D; Kirby, James E

2018-03-01

Microscopic interpretation of stained smears is one of the most operator-dependent and time-intensive activities in the clinical microbiology laboratory. Here, we investigated application of an automated image acquisition and convolutional neural network (CNN)-based approach for automated Gram stain classification. Using an automated microscopy platform, uncoverslipped slides were scanned with a 40× dry objective, generating images of sufficient resolution for interpretation. We collected 25,488 images from positive blood culture Gram stains prepared during routine clinical workup. These images were used to generate 100,213 crops containing Gram-positive cocci in clusters, Gram-positive cocci in chains/pairs, Gram-negative rods, or background (no cells). These categories were targeted for proof-of-concept development as they are associated with the majority of bloodstream infections. Our CNN model achieved a classification accuracy of 94.9% on a test set of image crops. Receiver operating characteristic (ROC) curve analysis indicated a robust ability to differentiate between categories with an area under the curve of >0.98 for each. After training and validation, we applied the classification algorithm to new images collected from 189 whole slides without human intervention. Sensitivity and specificity were 98.4% and 75.0% for Gram-positive cocci in chains and pairs, 93.2% and 97.2% for Gram-positive cocci in clusters, and 96.3% and 98.1% for Gram-negative rods. Taken together, our data support a proof of concept for a fully automated classification methodology for blood-culture Gram stains. Importantly, the algorithm was highly adept at identifying image crops with organisms and could be used to present prescreened, classified crops to technologists to accelerate smear review. This concept could potentially be extended to all Gram stain interpretive activities in the clinical laboratory. Copyright © 2018 American Society for Microbiology.

Rationalizing the permeation of polar antibiotics into Gram-negative bacteria

International Nuclear Information System (INIS)

Scorciapino, Mariano Andrea; Acosta-Gutierrez, Silvia; Benkerrou, Dehbia; D’Agostino, Tommaso; Malloci, Giuliano; Samanta, Susruta; Bodrenko, Igor; Ceccarelli, Matteo

2017-01-01

The increasing level of antibiotic resistance in Gram-negative bacteria, together with the lack of new potential drug scaffolds in the pipeline, make the problem of infectious diseases a global challenge for modern medicine. The main reason that Gram-negative bacteria are particularly challenging is the presence of an outer cell-protecting membrane, which is not present in Gram-positive species. Such an asymmetric bilayer is a highly effective barrier for polar molecules. Several protein systems are expressed in the outer membrane to control the internal concentration of both nutrients and noxious species, in particular: (i) water-filled channels that modulate the permeation of polar molecules and ions according to concentration gradients, and (ii) efflux pumps to actively expel toxic compounds. Thus, besides expressing specific enzymes for drugs degradation, Gram-negative bacteria can also resist by modulating the influx and efflux of antibiotics, keeping the internal concentration low. However, there are no direct and robust experimental methods capable of measuring the permeability of small molecules, thus severely limiting our knowledge of the molecular mechanisms that ultimately control the permeation of antibiotics through the outer membrane. This is the innovation gap to be filled for Gram-negative bacteria. This review is focused on the permeation of small molecules through porins, considered the main path for the entry of polar antibiotics into Gram-negative bacteria. A fundamental understanding of how these proteins are able to filter small molecules is a prerequisite to design/optimize antibacterials with improved permeation. The level of sophistication of modern molecular modeling algorithms and the advances in new computer hardware has made the simulation of such complex processes possible at the molecular level. In this work we aim to share our experience and perspectives in the context of a multidisciplinary extended collaboration within the IMI

Rationalizing the permeation of polar antibiotics into Gram-negative bacteria

Science.gov (United States)

Scorciapino, Mariano Andrea; Acosta-Gutierrez, Silvia; Benkerrou, Dehbia; D'Agostino, Tommaso; Malloci, Giuliano; Samanta, Susruta; Bodrenko, Igor; Ceccarelli, Matteo

2017-03-01

The increasing level of antibiotic resistance in Gram-negative bacteria, together with the lack of new potential drug scaffolds in the pipeline, make the problem of infectious diseases a global challenge for modern medicine. The main reason that Gram-negative bacteria are particularly challenging is the presence of an outer cell-protecting membrane, which is not present in Gram-positive species. Such an asymmetric bilayer is a highly effective barrier for polar molecules. Several protein systems are expressed in the outer membrane to control the internal concentration of both nutrients and noxious species, in particular: (i) water-filled channels that modulate the permeation of polar molecules and ions according to concentration gradients, and (ii) efflux pumps to actively expel toxic compounds. Thus, besides expressing specific enzymes for drugs degradation, Gram-negative bacteria can also resist by modulating the influx and efflux of antibiotics, keeping the internal concentration low. However, there are no direct and robust experimental methods capable of measuring the permeability of small molecules, thus severely limiting our knowledge of the molecular mechanisms that ultimately control the permeation of antibiotics through the outer membrane. This is the innovation gap to be filled for Gram-negative bacteria. This review is focused on the permeation of small molecules through porins, considered the main path for the entry of polar antibiotics into Gram-negative bacteria. A fundamental understanding of how these proteins are able to filter small molecules is a prerequisite to design/optimize antibacterials with improved permeation. The level of sophistication of modern molecular modeling algorithms and the advances in new computer hardware has made the simulation of such complex processes possible at the molecular level. In this work we aim to share our experience and perspectives in the context of a multidisciplinary extended collaboration within the IMI

Clinical update on linezolid in the treatment of Gram-positive bacterial infections

Science.gov (United States)

Ager, Sally; Gould, Kate

2012-01-01

Gram-positive pathogens are a significant cause of morbidity and mortality in both community and health care settings. Glycopeptides have traditionally been the antibiotics of choice for multiresistant Gram-positive pathogens but there are problems with their use, including the emergence of glycopeptide-resistant strains, tissue penetration, and achieving and monitoring adequate serum levels. Newer antibiotics such as linezolid, a synthetic oxazolidinone, are available for the treatment of resistant Gram-positive bacteria. Linezolid is active against a wide range of Gram-positive bacteria and has been generally available for the treatment of Gram-positive infections since 2000. There are potential problems with linezolid use, including its bacteriostatic action and the relatively high incidence of reported adverse effects, particularly with long-term use. Long-term use may also be complicated by the development of resistance. However, linezolid has been shown to be clinically useful in the treatment of several serious infections where traditionally bacteriocidal agents have been required and many of its adverse effects are reversible on cessation. It has also been shown to be a cost-effective treatment option in several studies, with its high oral bioavailability allowing an early change from intravenous to oral formulations with consequent earlier patient discharge and lower inpatient costs. PMID:22787406

Inhibition of various gram-positive and gram-negative bacteria growth on selenium nanoparticle coated paper towels.

Science.gov (United States)

Wang, Qi; Larese-Casanova, Philip; Webster, Thomas J

2015-01-01

There are wide spread bacterial contamination issues on various paper products, such as paper towels hanging in sink splash zones or those used to clean surfaces, filter papers used in water and air purifying systems, and wrappings used in the food industry; such contamination may lead to the potential spread of bacteria and consequent severe health concerns. In this study, selenium nanoparticles were coated on normal paper towel surfaces through a quick precipitation method, introducing antibacterial properties to the paper towels in a healthy way. Their effectiveness at preventing biofilm formation was tested in bacterial assays involving Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus epidermidis. The results showed significant and continuous bacteria inhibition with about a 90% reduction from 24 to 72 hours for gram-positive bacteria including S. aureus and S. epidermidis. The selenium coated paper towels also showed significant inhibition of gram-negative bacteria like P. aeruginosa and E. coli growth at about 57% and 84%, respectively, after 72 hours of treatment. Therefore, this study established a promising selenium-based antibacterial strategy to prevent bacterial growth on paper products, which may lead to the avoidance of bacteria spreading and consequent severe health concerns.

NEUROPATÍA PERIFÉRICA POR PORFIRIA EN PACIENTE MASCULINO VIH POSITIVO

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Ariana Baptista Da Cunha

2013-07-01

Full Text Available La Porfiria Intermitente Aguda es una enfermedad metabólica rara ocasionada por una mutación genética que produciendo defectos enzimáticos en la formación del grupo Hemo. Entre todos los tipos de porfiria, es la de mayor incidencia, con una prevalencia global de 5/100.000 habitantes con cúmulos de casos en zonas como Escandinavia, Gran Bretaña, Murcia (España caracterizada por clínica neurológica, gastrointestinal y psiquiátrica. Afecta principalmente a mujeres en edad reproductiva. Se describe el caso de un paciente masculino de 38 años con inicio de clínica 14 meses antes dolor abdominal, deposiciones abundantes y asociado cuadriparesia con un mes de evolución. Reporte de serología VIH positivo y valoración neurológica considera diagnóstico de neuropatía periférica asociada a VIH. Por antecedente familiar de porfiria se estudia caso en el Instituto Venezolano de Investigaciones Científicas y se obtiene diagnóstico definitivo de Porfiria Intermitente Aguda en crisis, tratado con Hermaginato con mejoría significativa de la clínica a los siete días sin signos de crisis porfírica. Por ser de baja incidencia, esta patología no destaca entre los principales diagnósticos diferenciales en casos de disminución de la fuerza muscular y difiere en el abordaje específico. Si no es detectada a tiempo la debilidad muscular progresa a parálisis bulbar y muerte. Palabras Clave: Porfiria Intermitente Aguda; Cuadriparesia; VIH

NEUROPATÍA PERIFÉRICA POR PORFIRIA EN PACIENTE MASCULINO VIH POSITIVO

Directory of Open Access Journals (Sweden)

Ariana Baptista Da Cunha

2013-01-01

Full Text Available La Porfiria Intermitente Aguda es una enfermedad metabólica rara ocasionada por una mutación genética que produciendo defectos enzimáticos en la for- mación del grupo Hemo. Entre todos los tipos de porfiria, es la de mayor incidencia, con una prevalencia global de 5/100.000 habitantes con cúmulos de ca- sos en zonas como Escandinavia, Gran Bretaña, Murcia (España caracterizada por clínica neurológica, gastrointestinal y psiquiátrica. Afecta principalmente a mujeres en edad reproductiva. Se describe el caso de un paciente masculino de 38 años con inicio de clínica 14 meses antes dolor abdominal, deposiciones abundantes y asociado cuadriparesia con un mes de evolución. Reporte de serología VIH positivo y valoración neurológica considera diagnóstico de neu- ropatía periférica asociada a VIH. Por antecedente familiar de porfiria se estudia caso en el Instituto Venezolano de Investigaciones Científicas y se obtiene diagnóstico definitivo de Porfiria Intermitente Aguda en crisis, tratado con Hermaginato con mejoría significativa de la clínica a los siete días sin signos de crisis porfírica. Por ser de baja incidencia, esta patología no destaca entre los principales diagnósticos diferenciales en casos de disminución de la fuerza mus- cular y difiere en el abordaje específico. Si no es detectada a tiempo la debilidad muscular progresa a parálisis bulbar y muerte. Palabras Clave: Porfiria Intermitente Aguda; Cuadriparesia; VIH.

Cellular reprogramming by gram-positive bacterial components: a review.

LENUS (Irish Health Repository)

Buckley, Julliette M

2012-02-03

LPS tolerance has been the focus of extensive scientific and clinical research over the last several decades in an attempt to elucidate the sequence of changes that occur at a molecular level in tolerized cells. Tolerance to components of gram-positive bacterial cell walls such as bacterial lipoprotein and lipoteichoic acid is a much lesser studied, although equally important, phenomenon. This review will focus on cellular reprogramming by gram-positive bacterial components and examines the alterations in cell surface receptor expression, changes in intracellular signaling, gene expression and cytokine production, and the phenomenon of cross-tolerance.

Estudo comparativo entre métodos de coloração para a pesquisa do bacilo álcool-ácido resistente em secreções pulmonares A comparative study between two staining methods employed in the search of alcohol acid resistant bacilli in pulmonary secretions

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Clara Pechmann Mendonça

1975-03-01

Full Text Available Apresentação do resultado comparativo entre dois métodos de coloração Osol e Ziehl-Neelsen para a pesquisa do bacilo álcool-ácido resistente, em 337 amostras secreção pulmonar. Foi realizada uma avaliação cultural de 287 amostras, mostrando que o método de Osol apresenta-se melhor nas baciloscopias discordantes e que há tendência em apresentar maior riqueza de germe.The comparative results obtained with the study of two staining methods, the Ziehl-Neelsen and the Osol ones, are presented. The study was performed with the alcohol acid resistant bacilli of 337 pulmonary secretion specimens. Evaluation cultures of 287 of these specimens were made. The Osol method proved to be better than the Ziehl-Neelsen one when dealing with discordant baciloscopic evidence. There tended to be a larger ammount of bacilli, too, when the former was used.

[Comparison of the quick Gram stain method to the B&M modified and favor methods].

Science.gov (United States)

Osawa, Kayo; Kataoka, Nobumasa; Maruo, Toshio

2011-01-01

The Gram stain is an established method for bacterial identification, but the time needed to carry out this stain is 2-3 min. We attempted to shorten this time and stained a total of 70 clinical specimens isolated from using the Bartholomew & Mittwer (B&M) modified or Favor methods with a 3 s duration for washing and staining steps. Results were plotted and analyzed using a Hue Saturation Intensity (HSI) model. The range based on a plot of the two methods with the HSI model was presented as a reference interval. Our results indicated that 100% (35/35) of strains were Gram positive and 97.1% (34/35) were Gram negative for the quick B&M modified method. In the quick Favor method, 80.0% (28/35) were Gram positive and 68.6% (24/35) of strains were Gram negative. We propose that the quick B&M modified method is equivalent to the standard Gram staining method and is superior to the quick Favor method.

Breaking barriers: expansion of the use of endolysins as novel antibacterials against Gram-negative bacteria.

Science.gov (United States)

Briers, Yves; Lavigne, Rob

2015-01-01

The emergence and spread of antibiotic-resistant bacteria drives the search for novel classes of antibiotics to replenish our armamentarium against bacterial infections. This is particularly critical for Gram-negative pathogens, which are intrinsically resistant to many existing classes of antibiotics due to the presence of a protective outer membrane. In addition, the antibiotics development pipeline is mainly oriented to Gram-positive pathogens such as methicillin-resistant Staphylococcus aureus. A promising novel class of antibacterials is endolysins. These enzymes encoded by bacterial viruses hydrolyze the peptidoglycan layer with high efficiency, resulting in abrupt osmotic lysis and cell death. Their potential as novel antibacterials to treat Gram-positive bacteria has been extensively demonstrated; however, the Gram-negative outer membrane has presented a formidable barrier for the use of endolysins against Gram-negatives until recently. This review reports on the most recent advances in the development of endolysins to kill Gram-negative species with a special focus on endolysin-engineered Artilysins(®).

The accuracy of Gram stain of respiratory specimens in excluding Staphylococcus aureus in ventilator-associated pneumonia.

Science.gov (United States)

Gottesman, Tamar; Yossepowitch, Orit; Lerner, Evgenia; Schwartz-Harari, Orna; Soroksky, Arie; Yekutieli, Daniel; Dan, Michael

2014-10-01

To evaluate the Gram stain of deep tracheal aspirate as a tool to direct empiric antibiotic therapy, and more specifically as a tool to exclude the need for empiric antibiotic coverage against Staphylococcus aureus in ventilator-associated pneumonia (VAP). A prospective, single-center, observational, cohort study. All wards at a community hospital. Adult patients requiring mechanical ventilation, identified as having VAP in a 54-month prospective surveillance database. Sampling of lower airway secretions by deep endotracheal aspiration was taken from each patient who developed VAP. Samples were sent immediately for Gram stain and qualitative bacterial cultures. Demographic and relevant clinical data were collected; Gram stain, culture, and antibiotic susceptibility results were documented; and outcome was followed prospectively. The analysis included 114 consecutive patients with 115 episodes of VAP from June 2007 to January 2012. Sensitivity of Gram stain compared with culture was 90.47% for gram-positive cocci, 69.6% for gram-negative rods, and 50% for sterile cultures. Specificity was 82.5%, 77.8%, and 79%, respectively. Negative predictive value was high for gram-positive cocci (97%) and sterile cultures (96%) but low for gram-negative rods (20%). Acinetobacter baumanii (45%) and Pseudomonas aeruginosa (38 %) were the prevailing isolates. S aureus was found in 18.3% of the patients. Most isolates were multiresistant. Absence of gram-positive bacteria on Gram stain had a high negative predictive value. These data can be used to narrow the initial empiric antibiotic regimen and to avoid unnecessary exposure of patients to vancomycin and other antistaphyloccocal agents. Copyright © 2014 Elsevier Inc. All rights reserved.

Antimicrobial-resistant Gram-negative bacteria in febrile neutropenic patients with cancer: current epidemiology and clinical impact.

Science.gov (United States)

Trecarichi, Enrico M; Tumbarello, Mario

2014-04-01

In the recent years, several studies involving cancer patients have demonstrated a clear trend in the epidemiology of bacterial infections showing a shift in the prevalence from Gram-positive to Gram-negative bacteria and the extensive emergence of antimicrobial-resistant strains among Gram-negatives isolated from the blood. The aim of this systematic review was to examine the recent trends in epidemiology and antimicrobial resistance in Gram-negatives recovered from neutropenic cancer patients, with particular emphasis on the impact of antimicrobial resistance on the clinical outcome of severe infections caused by such microorganisms. Overall, from 2007 to date, the rate of Gram-negative bacteria recovery ranged from 24.7 to 75.8% (mean 51.3%) in cancer patient cohorts. Escherichia coli represented the most common species (mean frequency of isolation 32.1%) among the Gram-negatives, followed by Pseudomonas aeruginosa (mean frequency of isolation 20.1%). An increasing frequency of Acinetobacter spp. and Stenotrophomonas maltophilia was also reported. Increased rates of multidrug-resistant Gram-negative strains have been highlighted among Enterobacteriaceae and nonfermenting Gram-negative rods, despite discontinuation of fluoroquinolone-based antibacterial prophylaxis for neutropenic patients. In addition, antimicrobial resistance and/or the inadequacy of empirical antibiotic treatment have been frequently linked to a worse outcome in cancer patients with bloodstream infections caused by Gram-negative isolates. Sound knowledge of the local distribution of pathogens and their susceptibility patterns and prompt initiation of effective antimicrobial treatment for severe infections caused by Gram-negative bacteria are essential in cancer patients.

Changing epidemiology of central venous catheter-related bloodstream infections: increasing prevalence of Gram-negative pathogens.

Science.gov (United States)

Marcos, Miguel; Soriano, Alex; Iñurrieta, Amaia; Martínez, José A; Romero, Alberto; Cobos, Nazaret; Hernández, Cristina; Almela, Manel; Marco, Francesc; Mensa, Josep

2011-09-01

Gram-positive microorganisms have been the predominant pathogens in central venous catheter-related bloodstream infections (CRBSIs). Recent guidelines recommend empirical therapy according to this and restrict coverage for Gram-negatives to specific circumstances. This study aimed to analyse the epidemiological changes in CRBSIs over the 1991-2008 period and to analyse predictors of Gram-negative CRBSIs. A prospectively collected cohort of patients with confirmed CRBSIs was analysed. Strains isolated and antimicrobial susceptibility, as well as clinical and demographic variables were recorded. Differences observed during the study period were analysed by means of a χ² trend test and factors associated with Gram-negative CRBSIs by means of multivariable analysis. Between 1991 and 2008, 1129 episodes of monomicrobial CRBSIs were recorded. There was an increase in the incidence of CRBSIs, from 0.10 (1991-92) to 0.31 (2007-08) episodes/1000 patient-days. A significant increase in the number of Gram-negative strains among the total isolates was also found, from 3 (4.7%) in 1991-92 to 70 (40.23%) in 2007-08, with a parallel decrease in the percentage of Gram-positives. Solid organ transplantation, prior use of penicillins and hospital stay longer than 11 days were independently associated with a significantly higher risk of Gram-negative CRBSIs, while cirrhosis, diabetes and use of quinolones were associated with a higher risk of Gram-positives. Gram-negative strains are an increasing cause of CRBSIs, reaching a prevalence of 40% in the 2007-08 period in our hospital. If this trend is confirmed in other centres, a broad-spectrum empirical therapy should be considered in managing these infections.

Gram staining of protected pulmonary specimens in the early diagnosis of ventilator-associated pneumonia.

Science.gov (United States)

Mimoz, O; Karim, A; Mazoit, J X; Edouard, A; Leprince, S; Nordmann, P

2000-11-01

We evaluated prospectively the use of Gram staining of protected pulmonary specimens to allow the early diagnosis of ventilator-associated pneumonia (VAP), compared with the use of 60 bronchoscopic protected specimen brushes (PSB) and 126 blinded plugged telescopic catheters (PTC) obtained from 134 patients. Gram stains were from Cytospin slides; they were studied for the presence of microorganisms in 10 and 50 fields by two independent observers and classified according to their Gram stain morphology. Quantitative cultures were performed after serial dilution and plating on appropriate culture medium. A final diagnosis of VAP, based on a culture of > or = 10(3) c.f.u. ml-1, was established after 81 (44%) samplings. When 10 fields were analysed, a strong relationship was found between the presence of bacteria on Gram staining and the final diagnosis of VAP (for PSB and PTC respectively: sensitivity 74 and 81%, specificity 94 and 100%, positive predictive value 91 and 100%, negative predictive value 82 and 88%). The correlation was less when we compared the morphology of microorganisms observed on Gram staining with those of bacteria obtained from quantitative cultures (for PSB and PTC respectively: sensitivity 54 and 69%, specificity 86 and 89%, positive predictive value 72 and 78%, negative predictive value 74 and 84%). Increasing the number of fields read to 50 was associated with a slight decrease in specificity and positive predictive value of Gram staining, but with a small increase in its sensitivity and negative predictive value. The results obtained by the two observers were similar to each other for both numbers of fields analysed. Gram staining of protected pulmonary specimens performed on 10 fields predicted the presence of VAP and partially identified (using Gram stain morphology) the microorganisms growing at significant concentrations, and could help in the early choice of the treatment of VAP. Increasing the number of fields read or having the Gram

The structures of lipopolysaccharides from plant-associated gram-negative bacteria

DEFF Research Database (Denmark)

Molinaro, Antonio; Newman, Mari-Anne; Lanzetta, Rosa

2009-01-01

Gram-negative bacterial lipopolysaccharides (LPSs) have multiple roles in plant-microbe interactions. LPSs contribute to the low permeabilities of bacterial outer membranes, which act as barriers to protect bacteria from plant-derived antimicrobial substances. Conversely, perception of LPSs...... is an important prerequisite for any further understanding of the biological processes in plant-microbe interactions. Moreover, the LPSs from Gram-negative bacteria - especially those originating from plant-associated bacteria - are a great source of novel monosaccharides with unusual and occasionally astounding...

Gram and acridine orange staining for diagnosis of septic arthritis in different patient populations.

Science.gov (United States)

Cunningham, Gregory; Seghrouchni, Khalid; Ruffieux, Etienne; Vaudaux, Pierre; Gayet-Ageron, Angèle; Cherkaoui, Abdessalam; Godinho, Eduardo; Lew, Daniel; Hoffmeyer, Pierre; Uçkay, Ilker

2014-06-01

The sensitivity of Gram staining is known to be suboptimal for the diagnosis of native joint septic arthritis. We lack information about the accuracy of Gram compared to other microscopic staining techniques for predicting infection in different patient populations. This was a cohort study with cost evaluations at the Orthopaedic Service of Geneva University Hospitals (January 1996-October 2012). Among 500 episodes of arthritis (196 with immunosuppression, 227 with underlying arthroplasties and 69 with gout or other crystals in synovial fluid), Gram staining revealed pathogens in 146 episodes (146/500, 29 %) or in 146 of the 400 culture-positive episodes (37 %). Correlation between the Gram and acridine staining of the same sample was good (Spearman 0.85). Overall, the sensitivity, specificity, positive predictive value and negative predictive value of Gram stain for rapid diagnosis of septic arthritis was 0.37, 0.99, 0.99 and 0.28, respectively, compared to microbiological cultures. Quite similar values were recorded across the different patient subpopulations, in particular for sensitivity values that were 0.33 for patients with prosthetic joint infections, 0.40 for immunosuppressed patients, 0.36 for patients under antibiotic administration and 0.52 for patients with concomitant crystalline disease. The sensitivity of Gram or acridine orange staining for a rapid diagnosis of episodes of septic arthritis is suboptimal compared to microbiological culture, regardless of underlying conditions, immunosuppression or antibiotic therapy. The sensitivity in the presence of synovial fluid crystals is moderate. Acridine orange and Gram stains are equivalent.

Fast Structural Alignment of Biomolecules Using a Hash Table, N-Grams and String Descriptors

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Robert Preissner

2009-04-01

Full Text Available This work presents a generalized approach for the fast structural alignment of thousands of macromolecular structures. The method uses string representations of a macromolecular structure and a hash table that stores n-grams of a certain size for searching. To this end, macromolecular structure-to-string translators were implemented for protein and RNA structures. A query against the index is performed in two hierarchical steps to unite speed and precision. In the first step the query structure is translated into n-grams, and all target structures containing these n-grams are retrieved from the hash table. In the second step all corresponding n-grams of the query and each target structure are subsequently aligned, and after each alignment a score is calculated based on the matching n-grams of query and target. The extendable framework enables the user to query and structurally align thousands of protein and RNA structures on a commodity machine and is available as open source from http://lajolla.sf.net.

Tundmatud kohad ja asjade loomus / Katrine Gram Sloth, Johna Hansen ; intervjueerinud Laura Põld

Index Scriptorium Estoniae

Gram Sloth, Katrine, 1983-

2016-01-01

Taani kunstnik Katrine Gram Sloth ja Rootsi arhitekt Johna Hansen räägivad oma lapsepõlvest, kunstnikuteest, loomingust. Johna Hanseni jaapanipärasest einelaua installatsioonist "Laud" (2015-2016), Katrine Gram Slothi Islandil loodud teosest "Vista Revisited" (2015)

Green Gram Rotation Effects on Maize Growth Parameters and Soil Quality in Myanmar

Directory of Open Access Journals (Sweden)

Myo Kywe

2008-10-01

Full Text Available At present maize–green gram crop rotations are not widely practiced among farmers in Myanmar. However, this cropping system might become more popular in the future given raising prices for green gram and maize grain and scarcity of mineral nitrogen (N fertilizers in this Asian country. The results of a cropping systems experiment with continuous maize versus a green gram-maize rotation, manure application (0 and 2 t ha−1 and phosphorus (P fertilization (0 and 15 kg P ha−1 in each of five consecutive seasons revealed a strong decline in total dry matter and grains yields for both crops irrespective of the treatment. Treatment effects on yield components, nutrient concentrations, mycorrhizal infection and nematode infestation were small or negligible. The data show that in addition to manure used at 2 t ha−1, application of mineral N fertilizers is essential to maintain particularly maize yields. A comparison of different green gram cultivars did not indicate genotype specific effects on maize growth. The incorporation of legume residues, unless they are used as animal feed, is recommended to increase the recycling of N and to balance N fluxes when green gram is cultivated for seed.

Bacteremias in liver transplant recipients: shift toward gram-negative bacteria as predominant pathogens.

Science.gov (United States)

Singh, Nina; Wagener, Marilyn M; Obman, Asia; Cacciarelli, Thomas V; de Vera, Michael E; Gayowski, Timothy

2004-07-01

During the 1990s, gram-positive bacteria emerged as major pathogens after liver transplantation. We sought to determine whether the pathogens associated with bacteremias in liver transplant recipients have changed. Patients included 233 liver transplant recipients transplanted between 1989 and 2003. The proportion of all infections due to bacteremias increased significantly over time (P gram-negatives increased from 25% in the period of 1989-1993 to 51.8% in 1998-03, that of gram-positive bacteria decreased from 75% in the period of 1989-93 to 48.2% in the period of 1998-2003. Methicillin-resistant Staphylococcus aureus (MRSA), Klebsiella pneumoniae, and Pseudomonas aeruginosa were the most frequent pathogens in bacteremic patients. The incidence of bacteremias due to MRSA and Pseudomonas aeruginosa has remained unchanged (P gram-negative bacteria, particularly Klebsiella pneumoniae has increased (P =.02). Klebsiella pneumoniae isolates in the current quartile were not clonally related. In conclusion, bacteremias as a proportion of all infections in liver transplant recipients have increased significantly over time, due in part to a decline in infections due to other major pathogens, e.g., fungi, primarily Candida species, and CMV. Gram-negative bacteria have emerged as predominant pathogens in bacteremic liver transplant recipients.

Daptomycin treatment in Gram-positive vascular graft infections

Directory of Open Access Journals (Sweden)

Francisco Arnaiz de las Revillas

2018-03-01

Full Text Available Background: Daptomycin is a bactericidal antibiotic approved for the treatment of skin and soft tissue infections and right-side endocarditis. However, there is a lack of published data outlining its usefulness in vascular graft infections (VGI. The aim of this study was to describe the clinical experience of daptomycin use in the treatment of VGI caused by Gram-positive bacteria. Methods: This was a retrospective cohort study of patients diagnosed with VGI receiving daptomycin at a tertiary care hospital during the period January 2010 to December 2012. Results: Of a total 1066 consecutive patients who had undergone vascular grafts (VG, 25 were diagnosed with VGI. Fifteen of these patients (11 prosthetic VG, three autologous VG, one both types received daptomycin (median dose 6.7 mg/kg/day, range 4.1–7.1 mg/kg/day; median age 69 years, range 45–83 years; 80% male. The infected bypass was removed in 13 cases. The most common reason for selecting daptomycin was kidney failure (53%. The Gram-positive organisms isolated were coagulase-negative Staphylococcus (n = 10, Staphylococcus aureus (n = 3 (two methicillin-resistant S. aureus, Enterococcus faecium (n = 2, and Enterococcus faecalis (n = 1. The mean follow-up was 69 months (interquartile range 48–72 months. Ten patients (66.7% achieved complete healing of the VGI. A recurrence of the infection was observed in 100% of patients in whom the bypass was not removed. Among patients who did not achieve complete healing, one needed a supracondylar amputation and one died as a consequence of infection. Five patients received treatment with rifampicin in addition to daptomycin and they were all cured. Conclusions: The use of daptomycin and surgery for Gram-positive VGI was effective and well tolerated, and this may be a good alternative for the treatment of VGI in patients with peripheral arterial disease in whom renal insufficiency is common. Keywords: Daptomycin, Gram-positive, Vascular

Gramáticas de grafos y su aplicación en inferencia gramatical

OpenAIRE

Jeltsch F., Eric

1997-01-01

En este trabajo se presentan las gramáticas de grafos en particular un tipo de gramáticas de grafo las cuales tienen un contexto libre en el mecanismo de derivación al igual que las gramáticas de Chomsky proporcionando de esta manera un simple mecanismo para generar lenguajes de grafos. Para hacer transparente el proceso de generación de grafos se introducen los grafos decorados que son grafos equipados con una información adicional llamada hiperlíneal las cuales al ser reemplazadas en forma ...

Measuring the Level of Agreement Between Cloacal Gram's Stains and Bacterial Cultures in Hispaniolan Amazon Parrots ( Amazona ventralis ).

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Evans, Erika E; Mitchell, Mark A; Whittington, Julia K; Roy, Alma; Tully, Thomas N

2014-12-01

Cloacal or fecal Gram's stains and bacterial cultures are routinely performed during avian physical examinations to assess the microbial flora of the gastrointestinal tract. Although cloacal or fecal Gram's stains and bacterial cultures are considered routine diagnostic procedures, the level of agreement between the individual tests has not been determined. To investigate the level of agreement between results from Gram's stain and bacterial culture when used to assess cloacal or fecal samples from psittacine birds, samples were taken from 21 clinically healthy Hispaniolan Amazon parrots ( Amazona ventralis ) and tested by Gram's stain cytology and bacterial culture. Most bacteria (97.2%) identified by Gram's stain were gram positive. However, gram-negative organisms were identified in 7 of 21 (33.3%; 95% confidence interval: 13.3%-53.3%) birds. Escherichia coli was the only gram-negative organism identified on culture. Agreement between results of Gram's stain and culture was fair (weighted κ = 0.27). The results of this study suggest that Gram's stains and bacterial culture may need to be performed with a parallel testing strategy to limit the likelihood of misclassifying the microbial flora of psittacine patients.

Antibacterial activity of sphingoid bases and fatty acids against Gram-positive and Gram-negative bacteria.

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Fischer, Carol L; Drake, David R; Dawson, Deborah V; Blanchette, Derek R; Brogden, Kim A; Wertz, Philip W

2012-03-01

There is growing evidence that the role of lipids in innate immunity is more important than previously realized. How lipids interact with bacteria to achieve a level of protection, however, is still poorly understood. To begin to address the mechanisms of antibacterial activity, we determined MICs and minimum bactericidal concentrations (MBCs) of lipids common to the skin and oral cavity--the sphingoid bases D-sphingosine, phytosphingosine, and dihydrosphingosine and the fatty acids sapienic acid and lauric acid--against four Gram-negative bacteria and seven Gram-positive bacteria. Exact Kruskal-Wallis tests of these values showed differences among lipid treatments (P 500 μg/ml). Sapienic acid (MBC range, 31.3 to 375.0 μg/ml) was active against Streptococcus sanguinis, Streptococcus mitis, and Fusobacterium nucleatum but not active against Escherichia coli, Staphylococcus aureus, S. marcescens, P. aeruginosa, Corynebacterium bovis, Corynebacterium striatum, and Corynebacterium jeikeium (MBC > 500 μg/ml). Lauric acid (MBC range, 6.8 to 375.0 μg/ml) was active against all bacteria except E. coli, S. marcescens, and P. aeruginosa (MBC > 500 μg/ml). Complete killing was achieved as early as 0.5 h for some lipids but took as long as 24 h for others. Hence, sphingoid bases and fatty acids have different antibacterial activities and may have potential for prophylactic or therapeutic intervention in infection.

The usefulness of changing focus during examination using Gram staining as initial diagnostic clue for infective tuberculosis.

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Atsukawa, Yoshiko; Kawakami, Sayoko; Asahara, Miwa; Ishigaki, Shinobu; Tanaka, Takashi; Ono, Yasuo; Nishiya, Hajime; Fujisaki, Ryuichi; Koga, Ichiro; Ota, Yasuo; Miyazawa, Yukihisa

2011-08-01

Gram staining is a useful technique for detecting bacteria but is highly questionable in detecting Mycobacterium tuberculosis. Its detection generally requires special staining, such as Ziehl-Neelsen staining. We experienced three cases in which tuberculosis was first suggested by Gram staining of sputum or pus, confirmed by Ziehl-Neelsen staining, and diagnosed by polymerase chain reaction or culture. To find colorless tubercle bacilli in clinical samples with various organisms, varying the focus to slightly longer and shorter during study of the slides is indispensable. We present criteria for detecting infective pulmonary tuberculosis in Gram staining. First, in the ordinary focus, weakly stained, thin, gram-positive bacilli are found; second, with a slightly longer focus distance, the thin, cord-like, conspicuous gram-positive bacilli can be observed; and third, with a shorter focus distance, the gram-positive bacilli have changed into the brightened, colorless, or ghost ones. Four laboratory technologists each evaluated 20 Gram-stained samples after being lectured on the criteria, with no prior information about the sample. They accurately evaluated the presence of the bacilli in Gram-stained preparations in more than 90% of samples containing 3+ bacilli on Ziehl-Neelsen staining. Gram staining is available as an easy and rapid initial clue to recognize highly infective tuberculosis.

A Trojan-Horse Strategy Including a Bacterial Suicide Action for the Efficient Use of a Specific Gram-Positive Antibiotic on Gram-Negative Bacteria.

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Schalk, Isabelle J

2018-05-10

In the alarming context of rising bacterial antibiotic resistance, there is an urgent need to discover new antibiotics or increase and/or enlarge the activity of those currently in use. The need for new antibiotics is even more urgent in the case of Gram-negative bacteria, such as Acinetobacter, Pseudomonas, and Enterobacteria, which have become resistant to many antibiotics and have an outer membrane with very low permeability to drugs. Vectorization of antibiotics using siderophores may be a solution to bypass such a bacterial wall: the drugs use the iron transporters of the outer membrane as gates to enter bacteria in a Trojan-horse strategy. Designing siderophore-antibiotics that can cross outer membranes has become almost routine, but their transport across the inner membrane is still a limiting step, as well as a strategy that allows dissociation of the antibiotic from the siderophore once inside the bacteria. Liu et al. ( J. Med. Chem. 2018 , DOI: 10.1021/acs.jmedchem.8b00218 ) report the synthesis of a siderophore-cephalosporin compound and demonstrate that β-lactams, such as cephalosporins, can serve as β-lactamase-triggered releasable linkers to allow intracellular delivery of Gram-positive antibiotics to Gram-negative bacteria.

The target of daptomycin is absent from Escherichia coli and other gram-negative pathogens.

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Randall, Christopher P; Mariner, Katherine R; Chopra, Ian; O'Neill, Alex J

2013-01-01

Antistaphylococcal agents commonly lack activity against Gram-negative bacteria like Escherichia coli owing to the permeability barrier presented by the outer membrane and/or the action of efflux transporters. When these intrinsic resistance mechanisms are artificially compromised, such agents almost invariably demonstrate antibacterial activity against Gram negatives. Here we show that this is not the case for the antibiotic daptomycin, whose target appears to be absent from E. coli and other Gram-negative pathogens.

La Gramática Discursivo-Funcional

NARCIS (Netherlands)

Hengeveld, K.; Mackenzie, J.L.

2011-01-01

La Gramática Discursivo-Funcional (GDF) es una teoría funcional del lenguaje de inspiración tipológica que presenta una organización descendente (top-down) con el objeto de alcanzar la adecuación psicológica y que toma el Acto Discursivo como unidad básica de análisis para lograr la adecuación

Combinatorial events of insertion sequences and ICE in Gram-negative bacteria.

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Toleman, Mark A; Walsh, Timothy R

2011-09-01

The emergence of antibiotic and antimicrobial resistance in Gram-negative bacteria is incremental and linked to genetic elements that function in a so-called 'one-ended transposition' manner, including ISEcp1, ISCR elements and Tn3-like transposons. The power of these elements lies in their inability to consistently recognize one of their own terminal sequences, while recognizing more genetically distant surrogate sequences. This has the effect of mobilizing the DNA sequence found adjacent to their initial location. In general, resistance in Gram-negatives is closely linked to a few one-off events. These include the capture of the class 1 integron by a Tn5090-like transposon; the formation of the 3' conserved segment (3'-CS); and the fusion of the ISCR1 element to the 3'-CS. The structures formed by these rare events have been massively amplified and disseminated in Gram-negative bacteria, but hitherto, are rarely found in Gram-positives. Such events dominate current resistance gene acquisition and are instrumental in the construction of large resistance gene islands on chromosomes and plasmids. Similar combinatorial events appear to have occurred between conjugative plasmids and phages constructing hybrid elements called integrative and conjugative elements or conjugative transposons. These elements are beginning to be closely linked to some of the more powerful resistance mechanisms such as the extended spectrum β-lactamases, metallo- and AmpC type β-lactamases. Antibiotic resistance in Gram-negative bacteria is dominated by unusual combinatorial mistakes of Insertion sequences and gene fusions which have been selected and amplified by antibiotic pressure enabling the formation of extended resistance islands. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

In vitro susceptibility of gram-negative bacterial isolates to chlorhexidine gluconate.

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Mengistu, Y; Erge, W; Bellete, B

1999-05-01

To investigate the susceptibility of clinical isolates of gram-negative bacteria to chlorhexidine gluconate. Prospective laboratory study. Tikur Anbessa Hospital, Addis Ababa, Ethiopia. Clinical specimens from 443 hospital patients. Significant number of gram negative bacteria were not inhibited by chlorhexidine gluconate (0.02-0.05%) used for antisepsis. Four hundred and forty three strains of gram-negative bacteria were isolated from Tikur Anbessa Hospital patients. Escherichia coli (31.6%) and Klebsiella pneumoniae (23%) were the most frequently isolated bacteria followed by Proteus species (13.3%), Pseudomonas species (9.2%), and Citrobacter species (6.1%). Each organism was tested to chlorhexidine gluconate (CHG), minimum inhibitory concentration (MIC) ranging from 0.0001% to 1%w/v. All Salmonella species and E. coli were inhibited by CHG, MIC or = 0.1%). Our results showed that a significant number of the gram-negative bacterial isolates were not inhibited by CHG at the concentration used for disinfection of wounds or instruments (MIC 0.02-0.05% w/v). It is therefore important to select appropriate concentration of this disinfectant and rationally use it for disinfection and hospital hygiene. Continuing follow up and surveillance is also needed to detect resistant bacteria to chlorhexidine or other disinfectants in time.

Gram-negative folliculitis. A rare problem or is it underdiagnosed? Case report and literature review

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Sierra-Téllez Daniela, Ponce-Olivera Rosa María, Tirado-Sánchez Andrés

2011-07-01

Full Text Available AbstractGram-negative folliculitis may be the result of prolonged antibacterial treatments in patients with acne and rosacea. It is caused by alteration of facial skin flora and the nasal mucous, a decrease of Gram-positive bacteria and a proliferation of Gram-negative bacteria (for example Escherichia coli, Pseudomonas aeruginosa, Serratia marcescens, Klebsiella sp. and Proteus mirabilis. It should be considered in patients with acne who have not had a clinical improvement after 3-6 months of treatment with tetracyclines. The disease is underestimated, probably because bacteriological studies are rarely requested and the increased use of oral isotretinoin for acne management. One of the most effective treatments for Gram-negative folliculitis is oral isotretinoin (0.5-1 mg / kg / day for 4-5 months. We report the case of Gram negative folliculitis successfully treated with oral isotretinoin.

Rapid, highly sensitive detection of Gram-negative bacteria with lipopolysaccharide based disposable aptasensor.

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Zhang, Jian; Oueslati, Rania; Cheng, Cheng; Zhao, Ling; Chen, Jiangang; Almeida, Raul; Wu, Jayne

2018-07-30

Gram-negative bacteria are one of the most common microorganisms in the environment. Their differential detection and recognition from Gram-positive bacteria has been attracting much attention over the years. Using Escherichia coli (E. coli) as a model, we demonstrated on-site detection of Gram-negative bacteria by an AC electrokinetics-based capacitive sensing method using commercial microelectrodes functionalized with an aptamer specific to lipopolysaccharides. Dielectrophoresis effect was utilized to enrich viable bacteria to the microelectrodes rapidly, achieving a detection limit of 10 2 cells/mL within a 30 s' response time. The sensor showed a negligible response to Staphylococcus aureus (S. aureus), a Gram-positive species. The developed sensor showed significant advantages in sensitivity, selectivity, cost, operation simplicity, and response time. Therefore, this sensing method has shown great application potential for environmental monitoring, food safety, and real-time diagnosis. Copyright © 2018 Elsevier B.V. All rights reserved.

AVALIAÇÃO DA FLORA MICROBIANA E DE DEGERMAÇÃO EXPERIMENTAL EM EQUIPE DE ENFERMAGEM, AMBIENTE E MATERIAL SANITÁRIO, EM ENFERMARIA DE ORTOPEDIA E TRAUMATOLOGIA

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Celina de Arruda Camargo

1972-09-01

Full Text Available RESUMO Estudou-se a ecologia dos microrganismos aeróbios patogênicos em duas Enfermarias de Ortopedia e Traumatologia, observando-se predomínio de bactérias Gram negativas. A etiologia das infecções, adquiridas ou não no hospital, dos doentes internados, mostrou também predomínio acentuado de bactérias Gram negativas. As mãos e narinas de funcionários em contato direto com os doentes, mostraram presença de flora bacteriana aeróbia mista constituída de Gram positivos (patogênico e não patogênicos e Gram negativos. Os resultados obtidos com a antissepsia de utensílios sanitários com solução contendo composto quaternário de amônio, metanol e etanol foram excelentes.

Extended spectrum beta-lactamases in urinary gram-negative bacilli and their susceptibility pattern

International Nuclear Information System (INIS)

Mumtaz, S.

2008-01-01

Beta-lactamases of gram-negative bacteria are the most important mechanism of resistance against beta lactams. Two types of beta-lactamases can confer resistance against third generation cephalosporins inducible Chromosomal beta -lactamases and extended-spectrum beta-lactamases. The extended-spectrum beta lactamases producing Strains of Enterobacteriaceae have emerged as a major problem in hospitalized as well as community based infections resulting in range of infections from uncomplicated urinary tract infection to life threatening sepsis. The study was conducted at the Microbiology Department of Fauji Foundation Hospital, Rawalpindi over a period of two years (April 2004-March 2006). Multidrug resistance and extended spectrum beta-lactamases production was studied in 111 enteric Gram-negative bacilli isolated from urine of symptomatic patients (1- 70 years) including males and females from indoor and outdoor patients by using double disc diffusion technique. Prevalence of extended-spectrum beta-lactamases production was seen in 71 (61.2%) enteric gram-negative organisms, the most prevalent gram-negative organism was Klebsiella pneumoniae 40 (71.4%) followed by Escherichia coli 27 (62.8%) and Pseudomonas aeruginosa 3 (25%). The extended-spectrum beta-lactamases producers were more prevalent in indoor patients 63 (88.7%) compared to outdoor patients 8 (11.3%), more in females 43 (60.6%) than males, 28 (39.4%). The extended-spectrum beta-lactamases producing gram-negative rods had more antibiotic-resistant profile than non-producers. All enteric gram negative rods should be tested for the production of extended-spectrum beta-lactamases in routine microbiology laboratory. (author)

Effectiveness of oral antibiotics for definitive therapy of Gram-negative bloodstream infections.

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Kutob, Leila F; Justo, Julie Ann; Bookstaver, P Brandon; Kohn, Joseph; Albrecht, Helmut; Al-Hasan, Majdi N

2016-11-01

There is paucity of data evaluating intravenous-to-oral antibiotic switch options for Gram-negative bloodstream infections (BSIs). This retrospective cohort study examined the effectiveness of oral antibiotics for definitive treatment of Gram-negative BSI. Patients with Gram-negative BSI hospitalised for antibiotics were included in this study. The cohort was stratified into three groups based on bioavailability of oral antibiotics prescribed (high, ≥95%; moderate, 75-94%; and low, antibiotics were prescribed to 106, 179 and 77 patients, respectively, for definitive therapy of Gram-negative BSI. Mean patient age was 63 years, 217 (59.9%) were women and 254 (70.2%) had a urinary source of infection. Treatment failure rates were 2%, 12% and 14% in patients receiving oral antibiotics with high, moderate and low bioavailability, respectively (P = 0.02). Risk of treatment failure in the multivariate Cox model was higher in patients receiving antibiotics with moderate [adjusted hazard ratio (aHR) = 5.9, 95% CI 1.6-38.5; P = 0.005] and low bioavailability (aHR = 7.7, 95% CI 1.9-51.5; P = 0.003) compared with those receiving oral antimicrobial agents with high bioavailability. These data demonstrate the effectiveness of oral antibiotics with high bioavailability for definitive therapy of Gram-negative BSI. Risk of treatment failure increases as bioavailability of the oral regimen declines. Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

Vaginose Bacteriana em Mulheres com Infertilidade e em Menopausadas Bacterial Vaginosis In Menopausal Women and in Women with Infertility

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Miriam da Silva Wanderley

2001-12-01

Full Text Available Objetivo: analisar a prevalência de vaginose bacteriana (VB em mulheres inférteis e em menopausadas e os métodos mais comumente usados na prática clínica para o seu diagnóstico. Métodos: foram avaliadas retrospectivamente 104 pacientes na menopausa e 86 inférteis. A presença de corrimento vaginal característico, pH vaginal >4,5, teste das aminas (whiff test positivo e achado de vaginose bacteriana à coloração da secreção pelo Gram foram considerados positivos. Foi estabelecido diagnóstico de VB quando 3 dos 4 critérios acima fossem satisfeitos. Resultados: analisando os métodos diagnósticos separadamente observamos, entre as menopausadas, 29 pacientes com corrimento vaginal característico (28,1%, 10 (9,6% com whiff test positivo, 68 (65,4% com pH vaginal >4,5 e 34 (32,7% com teste do Gram positivo. Nas mulheres inférteis os resultados foram 20 (23,2%, 13 (15,1%, 61 (70,9% e 26 (30,2%, respectivamente. Ao analisarmos todos os critérios em conjunto, em 14 pacientes na menopausa (13,5% e em 15 inférteis (17,4% foi diagnosticada VB. Conclusão: a prevalência de VB foi similar nos 2 grupos de pacientes. Além disso, todos os métodos diagnósticos devem ser utilizados a fim de não se sub ou super-diagnosticar essa patologia.Purpose: to evaluate the prevalence of bacterial vaginosis (BV in menopausal and in infertile outpatients and to analyze the current clinical diagnostic methods. Methods: we evaluated retrospectively 104 menopausal women and 86 with infertility. Characteristic vaginal discharge on gynecological examination, pH >4.5, positive KOH whiff test, and bacterial vaginosis by Gram test were considered positive. BV was established when at least 3 out of 4 criteria were found. Results: among the menopausal women, 29 patients (28.1% were clinically positive for BV, 10 (9.6% had positive whiff test, 68 (65.4% vaginal pH >4.5, and 34 (32.7% positive Gram test. For the infertile patients the figures were 20 (23.2%, 13

Widespread Fosfomycin Resistance in Gram-Negative Bacteria Attributable to the Chromosomal fosA Gene

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Ryota Ito

2017-08-01

Full Text Available Fosfomycin is a decades-old antibiotic which is being revisited because of its perceived activity against many extensively drug-resistant Gram-negative pathogens. FosA proteins are Mn2+ and K+-dependent glutathione S-transferases which confer fosfomycin resistance in Gram-negative bacteria by conjugation of glutathione to the antibiotic. Plasmid-borne fosA variants have been reported in fosfomycin-resistant Escherichia coli strains. However, the prevalence and distribution of fosA in other Gram-negative bacteria are not known. We systematically surveyed the presence of fosA in Gram-negative bacteria in over 18,000 published genomes from 18 Gram-negative species and investigated their contribution to fosfomycin resistance. We show that FosA homologues are present in the majority of genomes in some species (e.g., Klebsiella spp., Enterobacter spp., Serratia marcescens, and Pseudomonas aeruginosa, whereas they are largely absent in others (e.g., E. coli, Acinetobacter baumannii, and Burkholderia cepacia. FosA proteins in different bacterial pathogens are highly divergent, but key amino acid residues in the active site are conserved. Chromosomal fosA genes conferred high-level fosfomycin resistance when expressed in E. coli, and deletion of chromosomal fosA in S. marcescens eliminated fosfomycin resistance. Our results indicate that FosA is encoded by clinically relevant Gram-negative species and contributes to intrinsic fosfomycin resistance.

Gram-Positive Uropathogens, Polymicrobial Urinary Tract Infection, and the Emerging Microbiota of the Urinary Tract.

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Kline, Kimberly A; Lewis, Amanda L

2016-04-01

Gram-positive bacteria are a common cause of urinary-tract infection (UTI), particularly among individuals who are elderly, pregnant, or who have other risk factors for UTI. Here we review the epidemiology, virulence mechanisms, and host response to the most frequently isolated Gram-positive uropathogens: Staphylococcus saprophyticus, Enterococcus faecalis, and Streptococcus agalactiae. We also review several emerging, rare, misclassified, and otherwise underreported Gram-positive pathogens of the urinary tract including Aerococcus, Corynebacterium, Actinobaculum, and Gardnerella. The literature strongly suggests that urologic diseases involving Gram-positive bacteria may be easily overlooked due to limited culture-based assays typically utilized for urine in hospital microbiology laboratories. Some UTIs are polymicrobial in nature, often involving one or more Gram-positive bacteria. We herein review the risk factors and recent evidence for mechanisms of bacterial synergy in experimental models of polymicrobial UTI. Recent experimental data has demonstrated that, despite being cleared quickly from the bladder, some Gram-positive bacteria can impact pathogenic outcomes of co-infecting organisms. When taken together, the available evidence argues that Gram-positive bacteria are important uropathogens in their own right, but that some can be easily overlooked because they are missed by routine diagnostic methods. Finally, a growing body of evidence demonstrates that a surprising variety of fastidious Gram-positive bacteria may either reside in or be regularly exposed to the urinary tract and further suggests that their presence is widespread among women, as well as men. Experimental studies in this area are needed; however, there is a growing appreciation that the composition of bacteria found in the bladder could be a potentially important determinant in urologic disease, including susceptibility to UTI.

Gram-negative and -positive bacteria differentiation in blood culture samples by headspace volatile compound analysis.

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Dolch, Michael E; Janitza, Silke; Boulesteix, Anne-Laure; Graßmann-Lichtenauer, Carola; Praun, Siegfried; Denzer, Wolfgang; Schelling, Gustav; Schubert, Sören

2016-12-01

Identification of microorganisms in positive blood cultures still relies on standard techniques such as Gram staining followed by culturing with definite microorganism identification. Alternatively, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry or the analysis of headspace volatile compound (VC) composition produced by cultures can help to differentiate between microorganisms under experimental conditions. This study assessed the efficacy of volatile compound based microorganism differentiation into Gram-negatives and -positives in unselected positive blood culture samples from patients. Headspace gas samples of positive blood culture samples were transferred to sterilized, sealed, and evacuated 20 ml glass vials and stored at -30 °C until batch analysis. Headspace gas VC content analysis was carried out via an auto sampler connected to an ion-molecule reaction mass spectrometer (IMR-MS). Measurements covered a mass range from 16 to 135 u including CO2, H2, N2, and O2. Prediction rules for microorganism identification based on VC composition were derived using a training data set and evaluated using a validation data set within a random split validation procedure. One-hundred-fifty-two aerobic samples growing 27 Gram-negatives, 106 Gram-positives, and 19 fungi and 130 anaerobic samples growing 37 Gram-negatives, 91 Gram-positives, and two fungi were analysed. In anaerobic samples, ten discriminators were identified by the random forest method allowing for bacteria differentiation into Gram-negative and -positive (error rate: 16.7 % in validation data set). For aerobic samples the error rate was not better than random. In anaerobic blood culture samples of patients IMR-MS based headspace VC composition analysis facilitates bacteria differentiation into Gram-negative and -positive.

Effect of gamma radiation on physico-chemical characteristics of red gram (Cajanus cajan) starch

International Nuclear Information System (INIS)

Nene, S.P.; Vakil, U.K.; Sreenivasan, A.

1975-01-01

Total reducing and nonreducing sugars in red gram (Cajanus cajan) are not affected by radiation treatment (1 Mrad). Oligosaccharides, reported as flatulence factors in legumes, namely stachyose and raffinose, are slightly decreased on cooking the irradiated samples. Irradiated and cooked red gram starch is more susceptible to alpha-amylase action than the unirradiated sample. Rheological properties of red gram starch, such as gelatinization viscosity, swelling power and solubility improve on irradiation resulting in a final cooked product with better textural properties. (U.S.)

Análise microbiológica de gastroscópios descontaminados em aparelho Cleantop WM-1 por uso de água eletrolítica ácida Microbiological evaluation of gastroscope decontamination by electrolysed acid water (Clentop WM-1

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Alexandre Paulo Machado

2005-03-01

Full Text Available RACIONAL: O método com utilização manual de glutaraldeído é amplamente empregado para desinfecção de endoscópios. A elevada rotina nos serviços de gastroscopia, pequena quantidade de equipamentos e a falta de conhecimento técnico sobre os processos de descontaminação contribuem para desinfecção inadequada dos endoscópios, intensificando o risco de transmissão de microrganismos. A água eletrolítica ácida tem apresentado eficácia na inativação e destruição de microrganismos e vem sendo usada na descontaminação de endoscópios. OBJETIVO: Verificar a eficiência microbicida da água eletrolítica ácida, produzida pelo aparelho Cleantop WM-1, em 20 gastroscópios contaminados após uso em pacientes. MATERIAL E MÉTODOS: Amostras coletadas do canal de biopsia dos endoscópios, após uso em pacientes (n = 20 e depois da desinfecção (n = 20, foram cultivadas em ágar tripticaseína de soja, MacConkey e Sabouraud dextrose. RESULTADOS: Dezessete das 20 amostras coletadas após o uso do aparelho em pacientes revelaram a presença de bacilos gram-negativos, cocos gram-positivos e leveduras em taxas de 10³ a 10(5 ufc/mL. Nenhuma amostra, das 20 coletadas após a descontaminação, apresentou contaminação microbiana. CONCLUSÃO: Nesse estudo preliminar, a desinfecção mecânica realizada pelo aparelho Cleantop com água eletrolítica ácida revelou resultados satisfatórios pela eliminação de microrganismos e otimização no tempo de processamento dos gastroscópiosBACKGROUND: The manual disinfection of endoscopes with glutharaldeyde is widely employed. The great routine in gastroenteroscopy services, low number of equipment and the lack of technical knowledge about the decontamination processes are factors that stimulate the inadequate endoscope disinfection, intensifying the risk of transmission of microorganisms. The electrolysed acid water has been effective in the inactivation and destruction of microorganisms. AIM: The

Seguimiento a mujeres con resultado citológico positivo en una Empresa Social del Estado - ESE, Medellín, Colombia, 2011- 2012

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Marleny Valencia Arredondo

2017-01-01

Full Text Available En Colombia el cáncer cérvico-uterino (Cacu es una de las principales causas de muerte. Anualmente se diagnostican 7.000 casos y se registran 3.300 muertes, el 50% por diagnóstico tardío y falta de acceso a tratamientos especializados. Objetivo: describir el seguimiento a mujeres con resultado citológico positivo en una ESE de Medellín, 2011-2012. Metodología: estudio descriptivo transversal en 277 mujeres con resultado citológico positivo para lesiones sugestivas de alto grado y/o alteraciones glandulares. Se empleó muestreo estratificado y sistemático. Se utilizaron fuentes de información primaria y secundaria. La sistematización de datos se realizó en el programa SPSS, y se calcularon medidas de frecuencia, tendencia central y dispersión. Se empleó análisis descriptivo uni-bivariado para variables sociodemográficas, clínicas y relacionadas con la atención recibida. Resultados: el 10,7% de mujeres con lesiones de alto grado o invasoras no culminaron el tratamiento. La oportunidad total del seguimiento fue del 52,3% y las fases con mayores tiempos de espera para la atención fueron las citas para diagnóstico y tratamiento. Conclusión: A pesar de los esfuerzos para mejorar la cobertura del cribado y búsqueda activa de pacientes con citología positiva evidenciada en el estudio aún se presentan obstáculos en la atención de pacientes para un diagnóstico y tratamiento oportuno, lo que lleva en varios casos al avance de la enfermedad e incluso la muerte.

Resistance trends in gram-negative bacteria: surveillance results from two Mexican hospitals, 2005–2010

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Morfin-Otero Rayo

2012-06-01

Full Text Available Abstract Background Hospital-acquired infections caused by multiresistant gram-negative bacteria are difficult to treat and cause high rates of morbidity and mortality. The analysis of antimicrobial resistance trends of gram-negative pathogens isolated from hospital-acquired infections is important for the development of antimicrobial stewardship programs. The information obtained from antimicrobial resistant programs from two hospitals from Mexico will be helpful in the selection of empiric therapy for hospital-acquired gram-negative infections. Findings Two thousand one hundred thirty two gram-negative bacteria collected between January 2005 and December 2010 from hospital-acquired infections occurring in two teaching hospitals in Mexico were evaluated. Escherichia coli was the most frequently isolated gram-negative bacteria, with >50% of strains resistant to ciprofloxacin and levofloxacin. Klebsiella spp. showed resistance rates similar to Escherichia coli for ceftazidime (33.1% vs 33.2%, but exhibited lower rates for levofloxacin (18.2% vs 56%. Of the samples collected for the third most common gram-negative bacteria, Pseudomonas aeruginosa, >12.8% were resistant to the carbapenems, imipenem and meropenem. The highest overall resistance was found in Acinetobacter spp. Enterobacter spp. showed high susceptibility to carbapenems. Conclusions E. coli was the most common nosocomial gram-negative bacilli isolated in this study and was found to have the second-highest resistance to fluoroquinolones (>57.9%, after Acinetobacter spp. 81.2%. This finding represents a disturbing development in a common nosocomial and community pathogen.

Diversity of pigmented Gram-positive bacteria associated with marine macroalgae from Antarctica.

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Leiva, Sergio; Alvarado, Pamela; Huang, Ying; Wang, Jian; Garrido, Ignacio

2015-12-01

Little is known about the diversity and roles of Gram-positive and pigmented bacteria in Antarctic environments, especially those associated with marine macroorganisms. This work is the first study about the diversity and antimicrobial activity of culturable pigmented Gram-positive bacteria associated with marine Antarctic macroalgae. A total of 31 pigmented Gram-positive strains were isolated from the surface of six species of macroalgae collected in the King George Island, South Shetland Islands. On the basis of 16S rRNA gene sequence similarities ≥99%, 18 phylotypes were defined, which were clustered into 11 genera of Actinobacteria (Agrococcus, Arthrobacter, Brachybacterium, Citricoccus, Kocuria, Labedella, Microbacterium, Micrococcus, Rhodococcus, Salinibacterium and Sanguibacter) and one genus of the Firmicutes (Staphylococcus). It was found that five isolates displayed antimicrobial activity against a set of macroalgae-associated bacteria. The active isolates were phylogenetically related to Agrococcus baldri, Brachybacterium rhamnosum, Citricoccus zhacaiensis and Kocuria palustris. The results indicate that a diverse community of pigmented Gram-positive bacteria is associated with Antartic macroalgae and suggest its potential as a promising source of antimicrobial and pigmented natural compounds. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Computing symmetrical strength of N-grams: a two pass filtering approach in automatic classification of text documents.

Science.gov (United States)

Agnihotri, Deepak; Verma, Kesari; Tripathi, Priyanka

2016-01-01

The contiguous sequences of the terms (N-grams) in the documents are symmetrically distributed among different classes. The symmetrical distribution of the N-Grams raises uncertainty in the belongings of the N-Grams towards the class. In this paper, we focused on the selection of most discriminating N-Grams by reducing the effects of symmetrical distribution. In this context, a new text feature selection method named as the symmetrical strength of the N-Grams (SSNG) is proposed using a two pass filtering based feature selection (TPF) approach. Initially, in the first pass of the TPF, the SSNG method chooses various informative N-Grams from the entire extracted N-Grams of the corpus. Subsequently, in the second pass the well-known Chi Square (χ(2)) method is being used to select few most informative N-Grams. Further, to classify the documents the two standard classifiers Multinomial Naive Bayes and Linear Support Vector Machine have been applied on the ten standard text data sets. In most of the datasets, the experimental results state the performance and success rate of SSNG method using TPF approach is superior to the state-of-the-art methods viz. Mutual Information, Information Gain, Odds Ratio, Discriminating Feature Selection and χ(2).

A molecular gram stain using broad range PCR and pyrosequencing technology: a potentially useful tool for diagnosing orthopaedic infections.

Science.gov (United States)

Kobayashi, Naomi; Bauer, Thomas W; Togawa, Daisuke; Lieberman, Isador H; Sakai, Hiroshige; Fujishiro, Takaaki; Tuohy, Marion J; Procop, Gary W

2005-06-01

The bacteria associated with orthopaedic infections are usually common gram-positive and gram-negative bacteria. This fundamental grouping of bacteria is a necessary first step in the selection of appropriate antibiotics. Since polymerase chain reaction (PCR) is more rapid and may be more sensitive than culture, we developed a postamplification pyrosequencing method to subcategorize bacteria based on a few nucleotide polymorphisms in the 16S rRNA gene. We validated this method using well-characterized strains of bacteria and applied it to specimens from spinal surgery cases with suspected infections. Lysates of 114 bacteria including 75 species were created following standard cultivation to obtain DNA. The DNA was amplified by a broad-range real-time PCR. The amplicons were evaluated by pyrosequencing and were classified as gram-positive, gram-negative, or acid-fast bacilli based on the first three to five nucleotides sequenced. In addition, clinical cases of suspected infection were obtained from spinal surgery. The results of the "molecular Gram stain" were compared with the results of traditional Gram stain and culture. The lysates of 107 (93.9%) of the bacteria extracts tested were appropriately categorized as gram-positive and gram-negative or as acid-fast bacilli on the basis of this assay. The sensitivity and specificity of this assay were 100% and 97.4% for gram-positive and 88.3% and 100% for gram-negative isolates. All of the five clinical samples were appropriately categorized as containing gram-positive or gram-negative bacteria with this assay. This study demonstrates that high sensitivity and specificity of a molecular gram stain may be achieved using broad-range real-time PCR and pyrosequencing.

Identificación de Intervenciones para el Desarrollo Positivo de la Juventud

Science.gov (United States)

Sardiñas, Lili M.; Padilla, Viviana; Aponte, Mari; Boscio, Ana Morales; Pedrogo, Coralee Pérez; Santiago, Betzaida; Morales, Ángela Pérez; Dávila, Paloma Torres; Cesáreo, Marizaida Sánchez

2017-01-01

Resumen En el mundo hay más personas en la etapa de la juventud que en cualquier otra etapa del desarrollo. La juventud en Puerto Rico enfrenta muchas situaciones que inciden en su desarrollo y preparación para la adultez. Por lo tanto, es imperante identificar intervenciones para el desarrollo positivo de la juventud que han demostrado ser basadas en la evidencia. Además, a partir de dicha identificación, desarrollar prácticas que ayuden a los jóvenes a desarrollarse para prevenir situaciones adversas, promover experiencias positivas y propiciar que los niños y jóvenes estén involucrados y comprometidos. Se identificaron 147 intervenciones a través de una revisión tradicional de la literatura científica estadounidense. Los resultados reflejan que las intervenciones atienden la reducción de factores de riesgo y el incremento de factores de protección. Sin embargo, ninguna intervención propicia que los niños y jóvenes estén involucrados y comprometidos con su desarrollo óptimo y con sus comunidades. No obstante, todas brindan herramientas que podrían ser de utilidad para fomentar dichas prácticas en el contexto de Puerto Rico. De las 147 intervenciones identificadas seis están diseñadas para la población puertorriqueña residente en la Isla. Con el propósito de hacer la información accesible a los profesionales y la comunidad se expandió la colección del Archivo de Programas y Prácticas Basadas en Evidencia para la Prevención. PMID:28919943

[Influence of serious infections due to Gram-negative bacteria on the hospital economy].

Science.gov (United States)

Martínez, B; Gómez, J; Gómez Vargas, J; Guerra, B; Ruiz Gómez, J; Simarro, E; Baños, V; Canteras, M; Valdes, M

2000-12-01

Nosocomial infections due to Gram-negative bacteria are very important since they are associated with high morbidity and high hospital costs. A prospective study of 250 inpatients was carried out, 200 of whom had Gram-negative bacterial infections. Patients were divided into groups of 50 according to the localization of the infection (urinary, surgical wound, respiratory tract and bacteremia), with a control group of 50 patients with similar characteristics but no infection. We calculated the cost for the different groups by multiplying the average length of hospital stay in days by the daily cost of the stay. Significant differences were observed in the average length of stay per patient according to the type of infection and how it was acquired. In terms of cost, nosocomial infection due to Gram-negative bacteria was 1,049,139 pesetas more expensive than community-acquired infection. The cost of the stay for patients with postsurgical infection due to Gram-negative bacteria was 1,108, 252 pesetas more expensive than for the group of control patients. Nosocomial infection due to Gram-negative bacteria is associated with a prolongation in hospital stay of 9 to 28 days, which is the factor that most reflects the cost that can be attributed to nosocomial infection. Consensual and protocolized measures which allow for better clinical management need to be developed.

Bruchid egg induced transcript dynamics in developing seeds of black gram (Vigna mungo.

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Indrani K Baruah

Full Text Available Black gram (Vigna mungo seeds are a rich source of digestible proteins, however, during storage these seeds are severely damaged by bruchids (Callosobruchus spp., reducing seed quality and yield losses. Most of the cultivated genotypes of black gram are susceptible to bruchids, however, few tolerant genotypes have also been identified but the mechanism of tolerance is poorly understood. We employed Suppression Subtractive Hybridization (SSH to identify specifically, but rarely expressed bruchid egg induced genes in black gram. In this study, Suppression Subtractive Hybridization (SSH library was constructed to study the genes involved in defense response in black gram against bruchid infestation. An EST library of 277 clones was obtained for further analyses. Based on CAP3 assembly, 134 unigenes were computationally annotated using Blast2GOPRO software. In all, 20 defense related genes were subject to quantitative PCR analysis (qPCR out of which 12 genes showed up-regulation in developing seeds of the pods oviposited by bruchids. Few major defense genes like defensin, pathogenesis related protein (PR, lipoxygenase (LOX showed high expression levels in the oviposited population when compared with the non-oviposited plants. This is the first report on defense related gene transcript dynamics during the bruchid-black gram interaction using SSH library. This library would be useful to clone defense related gene(s such as defensin as represented in our library for crop improvement.

Detection of Extended-Spectrum Β-Lactamases among Gram ...

African Journals Online (AJOL)

Biochemical tests confirmed the identity of the Gram-negative isolates to be members of the enterobactericeae, which included Klebsiella pneumoniae (60), Escherichia coli (98), Providencia Spp. (32), Morganella moganii (32), Shigella Spp. (14), Citrobacter freundii (14), Serratia marcescens (10), Salmonella paratyphi A ...

Paciente VIH positivo con tuberculosis sistémica y lesiones osteolíticas de la calvaria, semejando mieloma múltiple

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Victor Mechán

2010-07-01

Full Text Available Varón de 33 años, soltero, sin ocupación fija, promiscuo, con historia de relaciones homosexuales, ingesta crónica de alcohol, consumo de tabaco, marihuana, pasta básica y clorhidrato de cocaína, desde los 18 años. Infectado por el virus de la inmunodeficiencia humana, recibía tratamiento irregular con terapia antirretroviral de gran actividad (Targa entre 2006 y 2008, regularizada en los últimos 12 meses. Por presentar bacilo ácido alcohol resistente (BAAR pansensible en esputo, inició en junio 2008 tratamiento antituberculoso [2RHZE/4(HR2], retirándosele la medicación 6 meses después por presentar BAAR pulmonar negativo. En marzo de 2009, percibió dolor lumbar intenso, dificultad para caminar, hipertrofia de ganglios cervicales, tos, fiebre. Un cultivo de secreción ganglionar cervical descubrió M. tuberculosis resistente a rifampicina. La imagenología mostró lesiones osteolíticas múltiples en cráneo y vértebras dorsolumbares y tumefacciones renitentes en cuero cabelludo, antebrazo derecho y parrilla costal izquierda. Tras descartarse mieloma múltiple y metástasis cancerosas, se añadió tratamiento antituberculosis multidrogo resistente al Targa, notándose dos meses después involución de las tumefacciones renitentes, de la fiebre y mejoría del estado general. Tras 16 meses de tratamiento supervisado, el paciente aumentó 7 kg de peso, habiendo desaparecido la sintomatología que presentaba. Se discute la fisiopatología de las lesiones osteolíticas cráneo-vertebrales en un paciente con coinfección por el virus de la inmunodeficiencia humana y tuberculosis.

An unusual class of anthracyclines potentiate Gram-positive antibiotics in intrinsically resistant Gram-negative bacteria

Science.gov (United States)

Cox, Georgina; Koteva, Kalinka; Wright, Gerard D.

2014-01-01

Objectives An orthogonal approach taken towards novel antibacterial drug discovery involves the identification of small molecules that potentiate or enhance the activity of existing antibacterial agents. This study aimed to identify natural-product rifampicin adjuvants in the intrinsically resistant organism Escherichia coli. Methods E. coli BW25113 was screened against 1120 actinomycete fermentation extracts in the presence of subinhibitory (2 mg/L) concentrations of rifampicin. The active molecule exhibiting the greatest rifampicin potentiation was isolated using activity-guided methods and identified using mass and NMR spectroscopy. Susceptibility testing and biochemical assays were used to determine the mechanism of antibiotic potentiation. Results The anthracycline Antibiotic 301A1 was isolated from the fermentation broth of a strain of Streptomyces (WAC450); the molecule was shown to be highly synergistic with rifampicin (fractional inhibitory concentration index = 0.156) and moderately synergistic with linezolid (FIC index = 0.25) in both E. coli and Acinetobacter baumannii. Activity was associated with inhibition of efflux and the synergistic phenotype was lost when tested against E. coli harbouring mutations within the rpoB gene. Structure–activity relationship studies revealed that other anthracyclines do not synergize with rifampicin and removal of the sugar moiety of Antibiotic 301A1 abolishes activity. Conclusions Screening only a subsection of our natural product library identified a small-molecule antibiotic adjuvant capable of sensitizing Gram-negative bacteria to antibiotics to which they are ordinarily intrinsically resistant. This result demonstrates the great potential of this approach in expanding antibiotic effectiveness in the face of the growing challenge of resistance in Gram-negatives. PMID:24627312

Epidemiology of infections caused by multiresistant gram-negatives: ESBLs, MBLs, panresistant strains.

Science.gov (United States)

Rossolini, Gian Maria; Mantengoli, Elisabetta; Docquier, Jean-Denis; Musmanno, Rosa Anna; Coratza, Grazietta

2007-07-01

Microbial drug resistance is a growing problem of global magnitude. In gram-negative pathogens, the most important resistance problems are encountered in Enterobacteriaceae, Pseudomonas aeruginosa and Acinetobacter, with increasing trends observed for all major anti-gram-negative agents (beta-lactams, fluoroquinolones and aminoglycosides). A matter of major concern is the emergence of new beta-lactamases capable of degrading the expanded-spectrum cephalosporins and/or carbapenems, such as the extended-spectrum beta-lactamases (ESBLs) and the carbapenemases. These beta-lactamase genes are often associated with resistance determinants to non-beta-lactam agents (e.g. aminoglycosides and fluoroquinolones), and strains producing ESBLs or carbapenemases often exhibit complex multidrug resistant phenotypes and sometimes are panresistant. The problem is worsened by the dearth of new agents active on multidrug-resistant Gram-negatives in the pipeline. The importance to develop better strategies to control resistance is underscored.

STUDY ON SURGICAL SITE INFECTIONS CAUSED BY ESBL PRODUCING GRAM NEGATIVE BACTERIA

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Rambabu

2015-09-01

Full Text Available Surgical site infections have been a major problem, because of the emergence of drug resistant bacteria, in particular B - lactamase producing bacteria. Extended spectrum beta lactamase producing gram negative organisms pose a great challenge in treatment o f SSI present study is aimed at determining multiple drug resistance in gram negative bacteria & to find out ESBL producers, in correlation with treatment outcome. A total of 120 wound infected cases were studied. Staphylococcus aureus was predominant bact erium - 20.Among gram negative bacteria, Pseudomonas species is predominant (14 followed by Escherichia coli (13 , Klebsiella species (12 , Proteus (9 Citrobacter (4 Providencia (2 & Acinetobacter species (2 . Out of 56 gramnegative bacteria isolated, 20 were i dentified as ESBL producers, which was statistically significant. Delay in wound healing correlated with infection by ESBL producers, which alarms the need of abstinence from antibiotic abuse

Prevalence of Gram-negative Pathogens and their antimicrobial ...

African Journals Online (AJOL)

The present study was conducted to find out the prevalence and spectrum of Gram negative pathogens causing bacterial meningitis and their antimicrobial susceptibility pattern in a tertiary care hospital. The cerebrospinal fluid (CSF) (3-5 ml) was collected from 638 admitted children clinically suspected of septic meningitis.

Sinus surgery postpones chronic gram-negative lung infection

DEFF Research Database (Denmark)

Alanin, M C; Aanaes, K; Høiby, N

2016-01-01

Background: In patients with cystic fibrosis (CF) the sinuses are a bacterial reservoir for Gram-negative bacteria (GNB). From the sinuses the GNB can repeatedly migrate to the lungs. In a one-year follow-up study, endoscopic sinus surgery (ESS) with adjuvant therapy reduced the frequency...

El método dialéctico transfinitante de Juan David García Bacca y el humanismo positivo como horizonte de la facticidad social

OpenAIRE

Gimeno Monfort, Xavier

2015-01-01

Nuestra intención en el presente trabajo es el siguiente: presentar del modo más sintético, concreto y preciso, las claves del “método dialéctico transfinitante” garcibacquiano. Analizaremos desde un punto de vista hermenéutico y crítico, el modo en el que el método dialéctico transfinitante es, en sí mismo, el sustento filosófico del humanismo positivo. Para ello, analizaremos los principales argumentos expuestos en Curso sistemático de filosofía actual que, a nue...

El Soporte Conductual Positivo y la comunicación como factores clave en la intervención educativa de los niños con TEA

OpenAIRE

Lizondo-Nieto, Elina Marcela

2013-01-01

En este trabajo, vamos a estudiar el Soporte Conductual Positivo aplicado a la Escuela (SCPE) como un método de intervención educativa que permite construir el aprendizaje de los niños con trastornos del espectro autista (TEA) a partir de las conductas problemáticas que estos manifiestan convirtiéndolas en habilidades, que, a su vez, van a ser reforzadas a través del sistema TEACCH, lo que combinado con un sistema alternativo y aumentativo de comunicación (SAAC), como el PECS, va ...

Black-pigmented gram-negative anaerobes in endodontic infections.

Science.gov (United States)

Haapasalo, M

1993-03-01

Necrotic dental root canal infections are polymicrobial infections dominated by anaerobic bacteria. The number of different species in one canal is usually low, approx. 4-7 species. The species isolated most frequently belong to the genera Prevotella, Porphyromonas, Fusobacterium, Peptostreptococcus, Eubacterium and Streptococcus. The frequency of isolation of black-pigmented Gram-negative anaerobes in endodontic infections varies from 25% to > 50%. Pr. intermedia is the most commonly found pigmented species, followed by Pr. denticola and two Porphyromonas species, P. gingivalis and P. endodontalis. Several studies have shown that P. gingivalis and P. endodontalis are closely related to the presence of acute symptoms in endodontic infections, whereas other black-pigmented Gram-negative anaerobes are not. However, several other species may also be involved in acute infections. Moreover, Porphyromonas species have occasionally been isolated from cases with no symptoms. Although Porphyromonas spp. are clearly related to symptoms at the beginning of therapy, they are not important for the prognosis of the treatment.

A classification system for plasmids from Enterococci and other Gram-positive bacteria

DEFF Research Database (Denmark)

Jensen, Lars Bogø; Garcia-Migura, Lourdes; Valenzuela, Antonio Jesus Sanchez

2010-01-01

A classification system for plasmids isolated from enterococci and other Gram-positive bacteria was developed based on 111 published plasmid sequences from enterococci and other Gram-positive bacteria; mostly staphylococci. Based on PCR amplification of conserved areas of the replication initiating....... Furthermore, conjugation experiments were performed obtaining 30 transconjugants when selecting for antimicrobial resistance. Among them 19 gave no positive amplicons indicating presence of rep-families not tested for in this experimental setup....

Community-acquired multidrug-resistant Gram-negative bacterial infective endocarditis.

Science.gov (United States)

Naha, Sowjanya; Naha, Kushal; Acharya, Vasudev; Hande, H Manjunath; Vivek, G

2014-08-05

We describe two cases of bacterial endocarditis secondary to multidrug-resistant Gram-negative organisms. In both cases, the diagnosis was made in accordance with the modified Duke's criteria and confirmed by histopathological analysis. Furthermore, in both instances there were no identifiable sources of bacteraemia and no history of contact with hospital or other medical services prior to the onset of symptoms. The patients were managed in similar fashion with prolonged broad-spectrum antibiotic therapy and surgical intervention and made complete recoveries. These cases highlight Gram-negative organisms as potential agents for endocarditis, as well as expose the dissemination of such multidrug-resistant bacteria into the community. The application of an integrated medical and surgical approach and therapeutic dilemmas encountered in managing these cases are described. 2014 BMJ Publishing Group Ltd.

Contingência e direito positivo: o paradoxo do direito na modernidade

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Marisse Costa de Queiroz

2004-12-01

Full Text Available Este artigo tem por objetivo apresentaraos leitores uma reflexão téorico-socialdo positivismo jurídico como paradigmaou matriz teórica que condiciona e interferenas construções científicas sobre o sistemajurídico na modernidade. Tal empenhotem como ponto de partida a consideraçãoque o direito positivo diferencia-se e estrutura-se na modernidade com um sistema quepretende dar conta da extrema contingênciade uma sociedade complexa como a sociedademoderna. Para tanto há a necessidade deadministrar e “controlar” a contingência domundo dos fatos e isso faz com que o direitoneutralize tal complexidade dentro do própriosistema. Essa diferenciação (evoluçãodo direito reflete-se nas teorias sobre o direito,culminando numa ruptura drástica daciência do direito ou da dogmática jurídicacom fundamentos valorativos para o direito.Contudo, essa tentativa também gera um paradoxo, qual seja: a normatização da vida(seleção, leva, necessariamente, à exclusãode outras possibilidades. Tento em vista ateoria sociológica luhmmaniana e à guisa deconclusões fechadas, tenta-se discutir esseparadoxo do direito moderno.This paper aims on presenting atheoretical-social reflection on legalpositivism as a paradigm through atheoretical matrix that restricts and interfereson scientific productions about the legalsystem in modern times. Such pledge beginsconsidering that the positive rights differand are structured on modernity, with asystem that aims on solving the extremecontingency of a complex society as themodern one. So, it is important to manageand “control” the world of fact contingencyand this helps law to neutralize suchcomplexity inside the own system. Thisevolution at law reflects on theories aboutlaw, ending in a drastic break of law scienceor legal doctrinaire full of valuable principlesfor law. However, this attempt also producesa paradox, which is: the ruling of life(selection leads, necessarily, to exclusion ofother

Inhaled Antibiotics for Gram-Negative Respiratory Infections

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Fraidenburg, Dustin R.; Scardina, Tonya

2016-01-01

SUMMARY Gram-negative organisms comprise a large portion of the pathogens responsible for lower respiratory tract infections, especially those that are nosocomially acquired, and the rate of antibiotic resistance among these organisms continues to rise. Systemically administered antibiotics used to treat these infections often have poor penetration into the lung parenchyma and narrow therapeutic windows between efficacy and toxicity. The use of inhaled antibiotics allows for maximization of target site concentrations and optimization of pharmacokinetic/pharmacodynamic indices while minimizing systemic exposure and toxicity. This review is a comprehensive discussion of formulation and drug delivery aspects, in vitro and microbiological considerations, pharmacokinetics, and clinical outcomes with inhaled antibiotics as they apply to disease states other than cystic fibrosis. In reviewing the literature surrounding the use of inhaled antibiotics, we also highlight the complexities related to this route of administration and the shortcomings in the available evidence. The lack of novel anti-Gram-negative antibiotics in the developmental pipeline will encourage the innovative use of our existing agents, and the inhaled route is one that deserves to be further studied and adopted in the clinical arena. PMID:27226088

Impact of round-the-clock CSF Gram stain on empirical therapy for suspected central nervous system infections.

Science.gov (United States)

Tissot, F; Prod'hom, G; Manuel, O; Greub, G

2015-09-01

The impact of round-the-clock cerebrospinal fluid (CSF) Gram stain on overnight empirical therapy for suspected central nervous system (CNS) infections was investigated. All consecutive overnight CSF Gram stains between 2006 and 2011 were included. The impact of a positive or a negative test on empirical therapy was evaluated and compared to other clinical and biological indications based on institutional guidelines. Bacterial CNS infection was documented in 51/241 suspected cases. Overnight CSF Gram stain was positive in 24/51. Upon validation, there were two false-positive and one false-negative results. The sensitivity and specificity were 41 and 99 %, respectively. All patients but one had other indications for empirical therapy than Gram stain alone. Upon obtaining the Gram result, empirical therapy was modified in 7/24, including the addition of an appropriate agent (1), addition of unnecessary agents (3) and simplification of unnecessary combination therapy (3/11). Among 74 cases with a negative CSF Gram stain and without formal indication for empirical therapy, antibiotics were withheld in only 29. Round-the-clock CSF Gram stain had a low impact on overnight empirical therapy for suspected CNS infections and was associated with several misinterpretation errors. Clinicians showed little confidence in CSF direct examination for simplifying or withholding therapy before definite microbiological results.

Genetic diversity in green gram [Vigna radiata (L.)] landraces ...

African Journals Online (AJOL)

GRACE

2006-07-03

Jul 3, 2006 ... nitrogen fixer for maintaining soil fertility. However ... use of radioactive elements makes it more costly and tedious. ... Figure 1. Geographic distribution of sampling localities of wild green gram in Southern Tamil Nadu, India.

Avaliação da qualidade dos dados, valor preditivo positivo, oportunidade e representatividade do sistema de vigilância epidemiológica da dengue no Brasil, 2005 a 2009

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Jakeline Ribeiro Barbosa

Full Text Available OBJETIVO: avaliar a qualidade dos dados, o valor preditivo positivo (VPP, a oportunidade e a representatividade do sistema de vigilância epidemiológica da dengue no Brasil entre 2005 e 2009. MÉTODOS: estudo de avaliação, com análise dos dados de dengue do Sistema de Informação de Agravos de Notificação (Sinan conforme atributos selecionados da metodologia do Centers for Disease Control and Prevention (Atlanta/GA, Estados Unidos da América. RESULTADOS: houve melhora na qualidade dos dados quanto a sua consistência; o VPP dos casos de dengue variou de 34 a 65%; o sistema apresentou uma mediana de oportunidade para notificação dos casos de 3 dias e revelou-se representativo, permitindo conhecer a situação da doença no país. CONCLUSÃO: o sistema de vigilância da dengue no Brasil mostrou-se consistente, com valor preditivo positivo expressivo, oportuno para notificação de casos e representativo, capaz de detectar tendência de mudança no perfil epidemiológico da doença.

Dose-Dependent Antimicrobial Activity of Silver Nanoparticles on Polycaprolactone Fibers against Gram-Positive and Gram-Negative Bacteria

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Erick Pazos-Ortiz

2017-01-01

Full Text Available The adhesion ability and adaptability of bacteria, coupled with constant use of the same bactericides, have made the increase in the diversity of treatments against infections necessary. Nanotechnology has played an important role in the search for new ways to prevent and treat infections, including the use of metallic nanoparticles with antibacterial properties. In this study, we worked on the design of a composite of silver nanoparticles (AgNPS embedded in poly-epsilon-caprolactone nanofibers and evaluated its antimicrobial properties against various Gram-positive and Gram-negative microorganisms associated with drug-resistant infections. Polycaprolactone-silver composites (PCL-AgNPs were prepared in two steps. The first step consisted in the reduction in situ of Ag+ ions using N,N-dimethylformamide (DMF in tetrahydrofuran (THF solution, and the second step involved the simple addition of polycaprolactone before electrospinning process. Antibacterial activity of PCL-AgNPs nanofibers against E. coli, S. mutans, K. pneumoniae, S. aureus, P. aeruginosa, and B. subtilis was evaluated. Results showed sensibility of E. coli, K. pneumoniae, S. aureus, and P. aeruginosa, but not for B. subtilis and S. mutans. This antimicrobial activity of PCL-AgNPs showed significant positive correlations associated with the dose-dependent effect. The antibacterial property of the PCL/Ag nanofibers might have high potential medical applications in drug-resistant infections.

In vitro activity of daptomycin against clinical isolates of Gram-positive bacteria.

Science.gov (United States)

Piper, Kerryl E; Steckelberg, James M; Patel, Robin

2005-08-01

We determined the activity of daptomycin, a recently FDA-approved antimicrobial agent, against clinical isolates of Gram-positive bacteria, including viridans group streptococci (16 Streptococcus mitis species group, 12 S. mutans species group, 9 S. anginosus species group, 8 S. sanguinis species group, 5 S. salivarius species group) from patients with infective endocarditis, 32 methicillin-resistant Staphylococcus aureus, 32 high-level penicillin-resistant Streptococcus pneumoniae, 38 vancomycin-resistant enterococci (including 1 linezolid-resistant isolate), and the following unusual Gram-positive bacteria: 3 Listeria monocytogenes, 4 Erysipelothrix rhusiopathiae, 9 Corynebacterium species, 10 Abiotrophia/Granulicatella species, 2 Rothia (Stomatococcus) mucilaginosus, and 4 Gemella morbillorum. Daptomycin minimum inhibitory concentration (MIC)(90) values for the viridans group streptococci, methicillin-resistant S. aureus, penicillin-resistant S. pneumoniae, and Enterococcus species were 0.5, 0.5, endocarditis as well as against several types of unusual Gram-positive bacteria that can cause endocarditis.

c-di-GMP Regulates Various Phenotypes and Insecticidal Activity of Gram-Positive Bacillus thuringiensis

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Yang Fu

2018-02-01

Full Text Available C-di-GMP has been well investigated to play significant roles in the physiology of many Gram-negative bacteria. However, its effect on Gram-positive bacteria is less known. In order to more understand the c-di-GMP functions in Gram-positive bacteria, we have carried out a detailed study on the c-di-GMP-metabolizing enzymes and their physiological functions in Bacillus thuringiensis, a Gram-positive entomopathogenic bacterium that has been applied as an insecticide successfully. We performed a systematic study on the ten putative c-di-GMP-synthesizing enzyme diguanylate cyclases (DGCs and c-di-GMP-degrading enzyme phosphodiesterases (PDEs in B. thuringiensis BMB171, and artificially elevated the intracellular c-di-GMP level in BMB171 by deleting one or more pde genes. We found increasing level of intracellular c-di-GMP exhibits similar activities as those in Gram-negative bacteria, including altered activities in cell motility, biofilm formation, and cell-cell aggregation. Unexpectedly, we additionally found a novel function exhibited by the increasing level of c-di-GMP to promote the insecticidal activity of this bacterium against Helicoverpa armigera. Through whole-genome transcriptome profile analyses, we found that 4.3% of the B. thuringiensis genes were differentially transcribed when c-di-GMP level was increased, and 77.3% of such gene products are involved in some regulatory pathways not reported in other bacteria to date. In summary, our study represents the first comprehensive report on the c-di-GMP-metabolizing enzymes, their effects on phenotypes, and the transcriptome mediated by c-di-GMP in an important Gram-positive bacterium.

A case of perforated sigmoid diverticulitis in which gram staining of ascitic fluid was useful for diagnosis.

Science.gov (United States)

Tsuchida, Junko; Fujita, Shouhei; Kawano, Fumihiro; Tsukamoto, Ryoichi; Honjo, Kunpei; Naito, Shigetoshi; Ishiyama, Shun; Miyano, Shozo; Machida, Michio; Kitabatake, Toshiaki; Fujisawa, Minoru; Kojima, Kuniaki; Ogura, Kanako; Matsumoto, Toshiharu

2014-01-01

An 85-year-old woman was admitted to our hospital for steroid therapy for relapsing nephrotic syndrome. During hospitalization, she complained of sudden epigastric pain at night. Although there were signs of peritoneal irritation, CT showed a large amount of ascitic fluid, but no free intraperitoneal gas. Gram staining of ascitic fluid obtained by abdominal paracentesis showed Gram-negative rods, which raised a strong suspicion of gastrointestinal perforation and peritonitis. Therefore, emergency surgery was performed. Exploration of the colon showed multiple sigmoid diverticula, one of which was perforated. The patient underwent an emergency Hartmann's procedure. Imaging studies failed to reveal any evidence of gastrointestinal perforation, presenting a diagnostic challenge. However, a physician performed rapid Gram staining of ascitic fluid at night when laboratory technicians were absent, had a strong suspicion of gastrointestinal perforation, and performed emergency surgery. Gram staining is superior in rapidity, and ascitic fluid Gram staining can aid in diagnosis, suggesting that it should be actively performed. We report this case, with a review of the literature on the significance of rapid diagnosis by Gram staining.

Intrinsic, adaptive and acquired antimicrobial resistance in Gram-negative bacteria.

Science.gov (United States)

Arzanlou, Mohsen; Chai, Wern Chern; Venter, Henrietta

2017-02-28

Gram-negative bacteria are responsible for a large proportion of antimicrobial-resistant infections in humans and animals. Among this class of bacteria are also some of the most successful environmental organisms. Part of this success is their adaptability to a variety of different niches, their intrinsic resistance to antimicrobial drugs and their ability to rapidly acquire resistance mechanisms. These mechanisms of resistance are not exclusive and the interplay of several mechanisms causes high levels of resistance. In this review, we explore the molecular mechanisms underlying resistance in Gram-negative organisms and how these different mechanisms enable them to survive many different stress conditions. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

Determination of the irradiation dose for the inhibition (D-10 radiation doses) of some gram negative and gram positive bacteria in peptone saline water

International Nuclear Information System (INIS)

Ayhan, H.; Tutluer, H.

1994-01-01

Determination of the irradiation dose for the inhibition of some pathogenic bacteria which cause food poisoning and spoilage were aimed. For this purpose, Salmonella typhi, Salmonella typhimurium,Salmonella enteridits,Klebsiella pneumonia, Pseudomonas fluorescence,Proteus vulgaris, Aeromonas hydrophila ,(gram-negative bacteria) and Bacillus cereus, Staphylococcus aureus strain 24,Staphylococcus aureus ATCC 6538 P,Staphylococcus epidermidis strain 115 and Clostridium perfringens A4TTK,(gram-positive bacteria) were used.Sensitivity of above mentioned bacteria to gamma rays (source Cs-137) was examined in saline with 0.1% peptone at different temperatures.Survivor plots (log.10 number of survivors versus dose) were determined by regression analysis of the data.Decimal reduction doses (D values in kGy) were calculated as the slope obtained from the regression analysis

Carbapenem-Resistant Non-Glucose-Fermenting Gram-Negative Bacilli: the Missing Piece to the Puzzle

Science.gov (United States)

Gniadek, Thomas J.; Carroll, Karen C.

2016-01-01

The non-glucose-fermenting Gram-negative bacilli Pseudomonas aeruginosa and Acinetobacter baumannii are increasingly acquiring carbapenem resistance. Given their intrinsic antibiotic resistance, this can cause extremely difficult-to-treat infections. Additionally, resistance gene transfer can occur between Gram-negative species, regardless of their ability to ferment glucose. Thus, the acquisition of carbapenemase genes by these organisms increases the risk of carbapenemase spread in general. Ultimately, infection control practitioners and clinical microbiologists need to work together to determine the risk carried by carbapenem-resistant non-glucose-fermenting Gram-negative bacilli (CR-NF) in their institution and what methods should be considered for surveillance and detection of CR-NF. PMID:26912753

False-Negative Rate of Gram-Stain Microscopy for Diagnosis of Septic Arthritis: Suggestions for Improvement

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Paul Stirling

2014-01-01

Full Text Available We quantify the false-negative diagnostic rate of septic arthritis using Gram-stain microscopy of synovial fluid and compare this to values reported in the peer-reviewed literature. We propose a method of improving the diagnostic value of Gram-stain microscopy using Lithium Heparin containers that prevent synovial fluid coagulation. Retrospective study of the Manchester Royal Infirmary microbiology database of patients undergoing synovial fluid Gram-stain and culture between December 2003 and March 2012 was undertaken. The initial cohort of 1896 synovial fluid analyses for suspected septic arthritis was reduced to 143 after exclusion criteria were applied. Analysis of our Gram-stain microscopy yielded 111 false-negative results from a cohort size of 143 positive synovial fluid cultures, giving a false-negative rate of 78%. We report a false-negative rate of Gram-stain microscopy for septic arthritis of 78%. Clinicians should therefore avoid the investigation until a statistically significant data set confirms its efficacy. The investigation's value could be improved by using Lithium Heparin containers to collect homogenous synovial fluid samples. Ongoing research aims to establish how much this could reduce the false-negative rate.

Numerically Stable Evaluation of Moments of Random Gram Matrices With Applications

KAUST Repository

Elkhalil, Khalil; Kammoun, Abla; Al-Naffouri, Tareq Y.; Alouini, Mohamed-Slim

2017-01-01

This paper focuses on the computation of the positive moments of one-side correlated random Gram matrices. Closed-form expressions for the moments can be obtained easily, but numerical evaluation thereof is prone to numerical stability, especially in high-dimensional settings. This letter provides a numerically stable method that efficiently computes the positive moments in closed-form. The developed expressions are more accurate and can lead to higher accuracy levels when fed to moment based-approaches. As an application, we show how the obtained moments can be used to approximate the marginal distribution of the eigenvalues of random Gram matrices.

Numerically Stable Evaluation of Moments of Random Gram Matrices With Applications

KAUST Repository

Elkhalil, Khalil

2017-07-31

This paper focuses on the computation of the positive moments of one-side correlated random Gram matrices. Closed-form expressions for the moments can be obtained easily, but numerical evaluation thereof is prone to numerical stability, especially in high-dimensional settings. This letter provides a numerically stable method that efficiently computes the positive moments in closed-form. The developed expressions are more accurate and can lead to higher accuracy levels when fed to moment based-approaches. As an application, we show how the obtained moments can be used to approximate the marginal distribution of the eigenvalues of random Gram matrices.

Prevalência da microbiota no trato digestivo de fêmeas de Lutzomyia longipalpis (Lutz & Neiva, 1912 (Diptera: Psychodidae provenientes do campo

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Oliveira Sandra Maria Pereira de

2000-01-01

Full Text Available No presente trabalho foram dissecados o trato digestivo de 245 fêmeas de Lutzomyia longipalpis originários da Gruta da Lapinha, Município de Lagoa Santa, MG, formando 7 grupos de 35 flebotomíneos. Das 8 espécies de bactérias isoladas houve uma predominância de bactérias Gram negativas (BGN pertencentes ao grupo de não fermentadoras de açúcar das seguintes espécies: Acinetobacter lowffii, Stenotrophomonas maltophhilia, Pseudomonas putida e Flavimonas orizihabitans. No grupo das fermentadoras tivemos: Enterobacter cloacae e Klebsiella ozaenae. No grupo dos Gram positivos foram identificados Bacillus thuringiensis e Staphylococcus spp.

Nicotinoprotein methanol dehydrogenase enzymes in Gram-positive methylotrophic bacteria

NARCIS (Netherlands)

Hektor, Harm J.; Kloosterman, Harm; Dijkhuizen, Lubbert

2000-01-01

A novel type of alcohol dehydrogenase enzyme has been characterized from Gram-positive methylotrophic (Bacillus methanolicus, the actinomycetes Amycolatopsis methanolica and Mycobacterium gastri) and non-methylotrophic bacteria (Rhodococcus strains). Its in vivo role is in oxidation of methanol and

Evaluation of Inhibitory and Lethal Effects of Aqueous, Ethanolic and Hydroalcoholic Extracts of Aerial Parts of Salvia chorassanica against Some Gram-negative and Gram-positive Bacteria in Vitro

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Azam Mehraban

2016-05-01

Full Text Available Abstract Background and Objectives: Development of bacterial resistance to antibiotics has led to an increased tendency to development of new more effective and non-toxic antimicrobial compounds. In this study, the inhibitory and lethal effects of aqueous, ethanolic, and hydroalcoholic extracts of aerial parts of Salvia chorassanica were evaluated against Listeria monocytogenes, Bacillus cereus, Salmonella typhi, and Escherichia coli O:157. Methods: In this study, Kirby–Bauer disk diffusion method was used to evaluate antimicrobial activity. In this method, bacteria were cultivated as grass culture in Mueller Hinton Agar (MHA media. To determine the minimum inhibitory concentration and minimum bactericidal concentration, micro-dilution method with ELISA and addition of phenyl tetrazolium chloride reagent, were used. Data were analyzed using one-way ANOVA and Duncan’s test at the significance level of p<0.05. Results: The highest diameter of inhibition in agar diffusion method was related to hydroalcoholic extract of aerial parts of Salvia chorassanica against Gram-positive bacteria Bacillus cereus. The amount of calculated MIC of hydro-alcoholic extract for Gram-positive bacteria was 30mg/ml. This amount was the lowest among other measured MIC. Conclusion: Based on the results of this study, Gram-negative bacteria showed more resistance to different extracts of aerial parts of Salvia chorassanica as compared to Gram-positive bacteria, so that Salmonella typhi was found to be the most resistant bacterium among the tested bacteria.

Gram stain microbiological pattern of upper extremities suppuration at Baptist Medical Centre, Ogbomoso Nigeria: a fifteen month review.

Science.gov (United States)

Oke, A J; Olaolorun, D A; Meier, D E; Tarpley, J L

2011-06-01

Sixty-eight (68) patients with serious upper extremity suppurative infections, presenting within a period of fifteen (15) months, were prospectively studied clinically, Gram stain of aspirates/pus were performed, specimen cultured, planted, and where indicated glucose levels and haemoglobin genotype determined. Half of the patients had hand infections. Staphylococcus aureus was isolated from thirty-nine (39) patients. Gram Negative bacilli, including Salmonella were more isolated from patients with diabetes mellitus or Hgb SS or SC. The Gram stain results correlated with the culture result 90%. When Gram Positive cocci were demonstrated in the primary microscopic examination, cultures were not mandatory. When no organism was demonstrated on primary Gram stain or the patient was diabetic or a sickler, cultures of the specimens were done. The Gram stain, well performed, remains a useful, inexpensive, technologically appropriate laboratory test for abetting decision making in patients with upper extremity suppurative infections. Organisms encountered in this study included: Staphylococcus aureus, Streptococcus pyogenes, Salmonella typhi, Proteus mirabilis, Pseudomonas aeruginosa, and Coliforms.

The Intersections of Science and Practice: Examples From FitnessGram® Programming.

Science.gov (United States)

Welk, Gregory J

2017-12-01

The FitnessGram® program has provided teachers with practical tools to enhance physical education programming. A key to the success of the program has been the systematic application of science to practice. Strong research methods have been used to develop assessments and standards for use in physical education, but consideration has also been given to ensure that programming meets the needs of teachers, students, parents, and other stakeholders. This essay summarizes some of these complex and nuanced intersections between science and practice with the FitnessGram® program. The commentaries are organized into 5 brief themes: science informing practice; practice informing science; balancing science and practice; promoting evidence-based practice; and the integration of science and practice. The article draws on personal experiences with the FitnessGram® program and is prepared based on comments shared during the 37th Annual C. H. McCloy Research Lecture at the 2017 SHAPE America - Society of Health and Physical Educators Convention.

[Diagnostic and therapeutic management of Gram-negative infections].

Science.gov (United States)

Bassetti, Matteo; Repetto, Ernestina

2008-04-01

Among Gram negative bacteria, Pseudomonas aeruginosa, the extended spectrum beta-lactamases (ESBL)-producing strains, Acinetobacter spp, in particular the multiresistant Acinetobacter baumannii, and Stenotrophomonas maltophilia are the most implicated micrororganisms in the ever more increasing problem of bacterial resistance. Possible solutions have to be searched, on one hand, in the use of new drugs but, on the other hand, in the re-evaluation of those already available drugs, possibly considering a new role for old drugs such as colistine and fosfomycin. Concerning ESBL-producing strains, the most recent data provided by EARSS report, in Italy, an incidence rate of 10-25 percent. The insurgence of an infection sustained by an ESBL+ve strain is strictly related to some well known risk factors, like the hospital stay itself, the disease severity, the length of stay in ICU, intubation and mechanical ventilation, catheterization, urinary or artery, and the past exposure to antibiotics. The raise in ESBL producing strains is closely related to the increasing use of cephalosporins. In the setting of a Gram negative infection, the combination therapy guarantees a higher coverage by reducing insurgence of possible resistance mechanisms, possibly resulting synergistic, and allowing a de-escalation therapy, although to this latter other problems, such as tolerability, costs and compliance, can be related. Another basic aspect to take into account of, in order to achieve the maximal efficacy of the antibiotic treatment, is the right dosage. In the idea to look for the best approach for the antibiotic treatment of a severe infection in a hospital setting, when a Gram negative aetiology is implicated, it can be possibly presumed that the right way consists in avoiding inappropriate antibiotic therapies, making therapeutic choices based on guidelines resulted from local epidemiological data, initiating the therapy promptly, avoiding excessive use of antibiotics, possibly

Antibacterial activity and interactions of plant essential oil combinations against Gram-positive and Gram-negative bacteria

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Cristina Anamaria Semeniuc

2017-04-01

Full Text Available The aim of this study was to compare the antibacterial effects of several essential oils (EOs alone and in combination against different Gram-positive and Gram-negative bacteria associated with food products. Parsley, lovage, basil, and thyme EOs, as well as their mixtures (1:1, v/v, were tested against Bacillus cereus, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Salmonella typhimurium. The inhibitory effects ranged from strong (thyme EO against E. coli to no inhibition (parsley EO against P. aeruginosa. Thyme EO exhibited strong (against E. coli, moderate (against S. typhimurium and B. cereus, or mild inhibitory effects (against P. aeruginosa and S. aureus, and basil EO showed mild (against E. coli and B. cereus or no inhibitory effects (against S. typhimurium, P. aeruginosa, and S. aureus. Parsley and lovage EOs revealed no inhibitory effects against all tested strains. Combinations of lovage/thyme and basil/thyme EOs displayed antagonistic effects against all bacteria, parsley/thyme EOs against B. cereus, S. aureus, P. aeruginosa, and E. coli, and lovage/basil EOs against B. cereus and E. coli. Combinations of parsley/lovage and parsley/basil EOs exhibited indifferent effects against all bacteria. The combination of lovage/basil EO showed indifferent effect against S. aureus, P. aeruginosa, and S. typhimurium, and the combination parsley/thyme EO against S. typhimurium. Thyme EO has the highest percentage yield and antibacterial potential from all tested formulations; its combination with parsley, lovage, and basil EOs determines a reduction of its antibacterial activity. Hence, it is recommended to be used alone as the antibacterial agent.

Dual beta-lactam therapy for serious Gram-negative infections: is it time to revisit?

Science.gov (United States)

Rahme, Christine; Butterfield, Jill M; Nicasio, Anthony M; Lodise, Thomas P

2014-12-01

We are rapidly approaching a crisis in antibiotic resistance, particularly among Gram-negative pathogens. This, coupled with the slow development of novel antimicrobial agents, underscores the exigency of redeploying existing antimicrobial agents in innovative ways. One therapeutic approach that was heavily studied in the 1980s but abandoned over time is dual beta-lactam therapy. This article reviews the evidence for combination beta-lactam therapy. Overall, in vitro, animal and clinical data are positive and suggest that beta-lactam combinations produce a synergistic effect against Gram-negative pathogens that rivals that of beta-lactam-aminoglycoside or beta-lactam-fluoroquinolone combination therapy. Although the precise mechanism of improved activity is not completely understood, it is likely attributable to an enhanced affinity to the diverse penicillin-binding proteins found among Gram negatives. The collective data indicate that dual beta-lactam therapy should be revisited for serious Gram-negative infections, especially in light of the near availability of potent beta-lactamase inhibitors, which neutralize the effect of problematic beta-lactamases. Copyright © 2014 Elsevier Inc. All rights reserved.

Linezolid: a promising option in the treatment of Gram-positives.

Science.gov (United States)

Zahedi Bialvaei, Abed; Rahbar, Mohammad; Yousefi, Mehdi; Asgharzadeh, Mohammad; Samadi Kafil, Hossein

2017-02-01

Linezolid, an oxazolidinone antimicrobial agent that acts by inhibiting protein synthesis in a unique fashion, is used in the treatment of community-acquired pneumonia, skin and soft-tissue infections and other infections caused by Gram-positive bacteria including VRE and methicillin-resistant staphylococci. Currently, linezolid resistance among these pathogens remains low, commonly linezolid susceptibility testing for this important agent and should be taken into account when considering its therapeutic use. Considering the importance of linezolid in the treatment of infections caused by Gram-positive bacteria, this review was undertaken to optimize the clinical use of this antibiotic. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Quorum sensing in gram-negative bacteria

DEFF Research Database (Denmark)

Wu, H.; Song, Z.J.; Høiby, N.

2004-01-01

Bacteria can communicate with each other by means of signal molecules to coordinate the behavior of the entire community, and the mechanism is referred to as quorum sensing (QS). Signal systems enable bacteria to sense the size of their densities by monitoring the concentration of the signal...... molecules. Among Gram-negative bacteria N-acyl-L-homoserine lactone (acyl-HSL)-dependent quorum sensing systems are particularly widespread. These systems are used to coordinate expression of phenotypes that are fundamental to the interaction of bacteria with each other and with their environment...

Associations Between Enteral Colonization With Gram-Negative Bacteria and Intensive Care Unit-Acquired Infections and Colonization of the Respiratory Tract.

Science.gov (United States)

Frencken, Jos F; Wittekamp, Bastiaan H J; Plantinga, Nienke L; Spitoni, Cristian; van de Groep, Kirsten; Cremer, Olaf L; Bonten, Marc J M

2018-02-01

Enteral and respiratory tract colonization with gram-negative bacteria may lead to subsequent infections in critically ill patients. We aimed to clarify the interdependence between gut and respiratory tract colonization and their associations with intensive care unit (ICU)-acquired infections in patients receiving selective digestive tract decontamination (SDD). Colonization status of the rectum and respiratory tract was determined using twice-weekly microbiological surveillance in mechanically ventilated subjects receiving SDD between May 2011 and June 2015 in a tertiary medical-surgical ICU in the Netherlands. Acquisition of infections was monitored daily by dedicated observers. Marginal structural models were used to determine the associations between gram-negative rectal colonization and respiratory tract colonization, ICU-acquired gram-negative infection, and ICU-acquired gram-negative bacteremia. Among 2066 ICU admissions, 1157 (56.0%) ever had documented gram-negative carriage in the rectum during ICU stay. Cumulative incidences of ICU-acquired gram-negative infection and bacteremia were 6.0% (n = 124) and 2.1% (n = 44), respectively. Rectal colonization was an independent risk factor for both respiratory tract colonization (cause-specific hazard ratio [CSHR], 2.93 [95% confidence interval {CI}, 2.02-4.23]) and new gram-negative infection in the ICU (CSHR, 3.04 [95% CI, 1.99-4.65]). Both rectal and respiratory tract colonization were associated with bacteremia (CSHR, 7.37 [95% CI, 3.25-16.68] and 2.56 [95% CI, 1.09-6.03], respectively). Similar associations were observed when Enterobacteriaceae and glucose nonfermenting gram-negative bacteria were analyzed separately. Gram-negative rectal colonization tends to be stronger associated with subsequent ICU-acquired gram-negative infections than gram-negative respiratory tract colonization. Gram-negative rectal colonization seems hardly associated with subsequent ICU-acquired gram-negative respiratory tract

Endocarditis : Effects of routine echocardiography during Gram-positive bacteraemia

NARCIS (Netherlands)

Vos, F J; Bleeker-Rovers, C P; Sturm, P D; Krabbe, P F M; van Dijk, A P J; Oyen, W J G; Kullberg, B J

2011-01-01

BACKGROUND: Despite firm recommendations to perform echocardiography in high-risk patients with Gram-positive bacteraemia, routine echocardiography is not embedded in daily practice in many settings. The aim of this study was to evaluate whether a regime including routine echocardiography results in

Prediction of lipoprotein signal peptides in Gram-negative bacteria

DEFF Research Database (Denmark)

Juncker, Agnieszka; Willenbrock, Hanni; Von Heijne, G.

2003-01-01

A method to predict lipoprotein signal peptides in Gram-negative Eubacteria, LipoP, has been developed. The hidden Markov model (HMM) was able to distinguish between lipoproteins (SPaseII-cleaved proteins), SPaseI-cleaved proteins, cytoplasmic proteins, and transmembrane proteins. This predictor ...

Development of a Multiplexed Microsphere PCR for Culture-Free Detection and Gram-Typing of Bacteria in Human Blood Samples.

Science.gov (United States)

Liang, Fang; Browne, Daniel J; Gray, Megan J; Gartlan, Kate H; Smith, David D; Barnard, Ross T; Hill, Geoffrey R; Corrie, Simon R; Markey, Kate A

2018-05-11

Bloodstream infection is a significant clinical problem, particularly in vulnerable patient groups such as those undergoing chemotherapy and bone marrow transplantation. Clinical diagnostics for suspected bloodstream infection remain centered around blood culture (highly variable timing, in the order of hours to days to become positive), and empiric use of broad-spectrum antibiotics is therefore employed for patients presenting with febrile neutropenia. Gram-typing provides the first opportunity to target therapy (e.g., combinations containing vancomycin or teicoplanin for Gram-positives; piperacillin-tazobactam or a carbapenem for Gram-negatives); however, current approaches require blood culture. In this study, we describe a multiplexed microsphere-PCR assay with flow cytometry readout, which can distinguish Gram-positive from Gram-negative bacterial DNA in a 3.5 h time period. The combination of a simple assay design (amplicon-dependent release of Gram-type specific Cy3-labeled oligonucleotides) and the Luminex-based readout (for quantifying each specific Cy3-labeled sequence) opens opportunities for further multiplexing. We demonstrate the feasibility of detecting common Gram-positive and Gram-negative organisms after spiking whole bacteria into healthy human blood prior to DNA extraction. Further development of DNA extraction methods is required to reach detection limits comparable to blood culture.

CARACTERIZAÇÃO DE GESTANTES COM TESTE RÁPIDO POSITIVO PARA HIV EM FORTALEZA-CE

Directory of Open Access Journals (Sweden)

LÉA MARIA MOURA BARROSO

2007-01-01

Full Text Available El objetivo fue describir a las gestantes sometidas al test rápido para detectar VIH/SIDA en una maternidad de Fortaleza- CE, en relación a las características sociodemográficas y clínicas. Estudio transversal del tipo documental retrospectivo, con trece gestantes sometidas al test rápido y con resultado positivo para VIH/SIDA en el periodo de abril de 2002 a abril de 2004. El promedio de edad de las gestantes era 26,2 años; el 61,5% estudió entre cuatro a siete años; el 69,2 % era de la capital y el 30,8 % del interior; el 53,8 % ama de casa; el 54,0 % con cuatro a siete consultas de prenatal; el 46,2 % fue diagnosticada antes del parto; el 84,6 % recibió profilaxis solamente en el parto; el 46,0% tuvo bolsa rota hasta cuatro horas antes del parto; el 77,0% parto quirúrgico y el 100% de los recién nacidos recibió el jarabe de AZT en las primeras dos horas de vida. Se concluye que la institución garantizó la reducción del riesgo de contaminación del recién nacido, sin embargo se percibió deficiencia en los servicios que ofrecieron atención antes del parto.

GRAM-CNN: a deep learning approach with local context for named entity recognition in biomedical text.

Science.gov (United States)

Zhu, Qile; Li, Xiaolin; Conesa, Ana; Pereira, Cécile

2018-05-01

Best performing named entity recognition (NER) methods for biomedical literature are based on hand-crafted features or task-specific rules, which are costly to produce and difficult to generalize to other corpora. End-to-end neural networks achieve state-of-the-art performance without hand-crafted features and task-specific knowledge in non-biomedical NER tasks. However, in the biomedical domain, using the same architecture does not yield competitive performance compared with conventional machine learning models. We propose a novel end-to-end deep learning approach for biomedical NER tasks that leverages the local contexts based on n-gram character and word embeddings via Convolutional Neural Network (CNN). We call this approach GRAM-CNN. To automatically label a word, this method uses the local information around a word. Therefore, the GRAM-CNN method does not require any specific knowledge or feature engineering and can be theoretically applied to a wide range of existing NER problems. The GRAM-CNN approach was evaluated on three well-known biomedical datasets containing different BioNER entities. It obtained an F1-score of 87.26% on the Biocreative II dataset, 87.26% on the NCBI dataset and 72.57% on the JNLPBA dataset. Those results put GRAM-CNN in the lead of the biological NER methods. To the best of our knowledge, we are the first to apply CNN based structures to BioNER problems. The GRAM-CNN source code, datasets and pre-trained model are available online at: https://github.com/valdersoul/GRAM-CNN. andyli@ece.ufl.edu or aconesa@ufl.edu. Supplementary data are available at Bioinformatics online.

Phosphorus Response and Amino Acid Composition of Different Green Gram (Vigna radiata L. Genotypes from Myanmar

Directory of Open Access Journals (Sweden)

M. Kywe

2007-10-01

Full Text Available Mungbean or green gram (Vigna radiata L. is an important component of rice-based cropping systems in Myanmar, where grain yields of around 800 kg ha^(-1 are much below its yield potential of 3000 kg ha^(-1. The reasons for this shortfall are as under-investigated as is the genotype-specific response of this crop to phosphorus (P application, which is critically low in many Myanmar soils, and the genetic variation in grain quality. For green gram quality, the concentration of lysine, an essential amino acid is particularly important given its scarcity in many cereal-based diets of Southeast Asia. The purpose of this study therefore was to investigate the effects of P application on the root and shoot growth, yield and its components for a range of green gram varieties, and to analyse the protein concentration and amino acid composition in green gram seed of different origins. To this end from 2001 to 2003, field experiments were conducted under rain-fed conditions in Yezin and Nyaung Oo. Fifteen landraces and five introduced green gram cultivars were grown at two levels of P (0 and 15 kg ha^(-1. There were large genotypic differences in P effects and a significant interaction between green gram genotypes and P for shoot and root growth. An unexpected benefit of P application was a reduction of pest and plant virus infestation in the field. Significant genotypic differences in the amino acid profile of seeds were also observed. The results indicate the potential for breeding efforts to increase seed yield and protein quality in green gram.

Multidrug resistance in enteric and other gram-negative bacteria.

Science.gov (United States)

George, A M

1996-05-15

In Gram-negative bacteria, multidrug resistance is a term that is used to describe mechanisms of resistance by chromosomal genes that are activated by induction or mutation caused by the stress of exposure to antibiotics in natural and clinical environments. Unlike plasmid-borne resistance genes, there is no alteration or degradation of drugs or need for genetic transfer. Exposure to a single drug leads to cross-resistance to many other structurally and functionally unrelated drugs. The only mechanism identified for multidrug resistance in bacteria is drug efflux by membrane transporters, even though many of these transporters remain to be identified. The enteric bacteria exhibit mostly complex multidrug resistance systems which are often regulated by operons or regulons. The purpose of this review is to survey molecular mechanisms of multidrug resistance in enteric and other Gram-negative bacteria, and to speculate on the origins and natural physiological functions of the genes involved.

Antibiotic-Resistant Gram Negative Bacilli in Meals Delivered at a General Hospital, Italy

Directory of Open Access Journals (Sweden)

Maria Rosa Anna Plano

2009-01-01

Full Text Available This study aimed at detecting the presence of antibiotic-resistant Gram-negatives in samples of meals delivered at the University General Hospital of Palermo, Italy. Antibiotic resistant Gram negatives were isolated in July—September 2007 ffrom cold dishes and food contact surfaces and utensils. Bacterial strains were submitted to susceptibility test and subtyped by random amplification of polymorphic DNA (RAPD. Forty-six of 55 (83.6% food samples and 14 of 17 (82.3% environmental swabs were culture positive for Gram negative bacilli resistant to at least one group of antibacterial drugs. A total of 134 antibiotic resistant strains, 51 fermenters and 83 non-fermenters, were recovered. Fermenters and non-fermenters showed frequencies as high as 97.8% of resistance to two or more groups of antibiotics and non fermenters were 28.9% resistant to more than three groups. Molecular typing detected 34 different profiles among the fermenters and 68 among the non-fermenters. Antibiotic resistance was very common among both fermenters and non-fermenters. However, the wide heterogeneity of RAPD patterns seems to support a prominent role of cross-contamination rather than a clonal expansion of a few resistant isolates. A contribution of commensal Gram negatives colonizing foods to a common bacterial resistance pool should not been overlooked.

Antibiotic-resistant gram negative bacilli in meals delivered at a general hospital, Italy.

Science.gov (United States)

Plano, Maria Rosa Anna; Di Noto, Anna Maria; Firenze, Alberto; Sciortino, Sonia; Mammina, Caterina

2009-01-01

This study aimed at detecting the presence of antibiotic-resistant Gram-negatives in samples of meals delivered at the University General Hospital of Palermo, Italy. Antibiotic resistant Gram negatives were isolated in July-September 2007 ffrom cold dishes and food contact surfaces and utensils. Bacterial strains were submitted to susceptibility test and subtyped by random amplification of polymorphic DNA (RAPD). Forty-six of 55 (83.6%) food samples and 14 of 17 (82.3%) environmental swabs were culture positive for Gram negative bacilli resistant to at least one group of antibacterial drugs. A total of 134 antibiotic resistant strains, 51 fermenters and 83 non-fermenters, were recovered. Fermenters and non-fermenters showed frequencies as high as 97.8% of resistance to two or more groups of antibiotics and non fermenters were 28.9% resistant to more than three groups. Molecular typing detected 34 different profiles among the fermenters and 68 among the non-fermenters. Antibiotic resistance was very common among both fermenters and non-fermenters. However, the wide heterogeneity of RAPD patterns seems to support a prominent role of cross-contamination rather than a clonal expansion of a few resistant isolates. A contribution of commensal Gram negatives colonizing foods to a common bacterial resistance pool should not been overlooked.

Diesel degradation and biosurfactant production by Gram-positive ...

African Journals Online (AJOL)

The ability of Gram-positive bacteria to degrade diesel increased in a comparable trend as its biosurfactant production increased. The E24 index was highest at 87.6% for isolate D9. Isolates D2, D9 and D10, were identified as Paenibacillus sp. whilst isolate DJLB was found to belong to Stenotrophomonas sp. This study ...

La Gramática en la enseñanza secundaria : las nociones de irregularidad y dependencia en las gramáticas pedagógicas de lengua española, 1901-1980 : estudio de su transposición didáctica

OpenAIRE

López Ferrero, Carmen

1997-01-01

[spa] La tesis doctoral La gramática en la enseñanza secundaria. Las nociones de irregularidad y dependencia en las gramáticas pedagógicas de lengua española (1901-1980): estudio de su transposición didáctica analiza las transformaciones didácticas que experimentan los conceptos lingüísticos (procedentes de las ciencias del lenguaje) cuando son introducidos en libros de texto de gramática (gramáticas pedagógicas) destinados a la enseñanza secundaria. El modelo de transposición didáctica esta...

Fighting infections due to multidrug-resistant Gram-positive pathogens.

Science.gov (United States)

Cornaglia, G

2009-03-01

Growing bacterial resistance in Gram-positive pathogens means that what were once effective and inexpensive treatments for infections caused by these bacteria are now being seriously questioned, including penicillin and macrolides for use against pneumococcal infections and-in hospitals-oxacillin for use against staphylococcal infections. As a whole, multidrug-resistant (MDR) Gram-positive pathogens are rapidly becoming an urgent and sometimes unmanageable clinical problem. Nevertheless, and despite decades of research into the effects of antibiotics, the actual risk posed to human health by antibiotic resistance has been poorly defined; the lack of reliable data concerning the outcomes resulting from antimicrobial resistance stems, in part, from problems with study designs and the methods used in resistence determination. Surprisingly little is known, too, about the actual effectiveness of the many types of intervention aimed at controlling antibiotic resistance. New antibiotics active against MDR Gram-positive pathogens have been recently introduced into clinical practice, and the antibiotic pipeline contains additional compounds at an advanced stage of development, including new glycopeptides, new anti-methicillin-resistant Staphylococcus aureus (MRSA) beta-lactams, and new diaminopyrimidines. Many novel antimicrobial agents are likely to be niche products, endowed with narrow antibacterial spectra and/or targeted at specific clinical problems. Therefore, an important educational goal will be to change the current, long-lasting attitudes of both physicians and customers towards broad-spectrum and multipurpose compounds. Scientific societies, such as the European Society of Clinical Microbiology and Infectious Diseases (ESCMID), must play a leading role in this process.

Medicalização dos desvios de comportamento na infância: aspectos positivos e negativos Medicalización de los desvíos de comportamiento en la infancia: aspectos positivos y negativos Medicalization of deviant behavior in children: positive and negative features

Directory of Open Access Journals (Sweden)

Fabíola Stolf Brzozowski

2013-01-01

Full Text Available A medicalização dos comportamentos desviantes na infância é apresentada como uma estratégia eficaz para lidar com crianças que apresentam algum tipo de dificuldade, sem que, no entanto, as dificuldades desse processo sejam claramente expostas. O processo de medicalização, porém, é complexo e apresenta muitos resultados negativos. Dentro desse contexto, nosso objetivo é refletir sobre essas dificuldades. Primeiramente, apresentamos como se dá a relação entre medicalização e infâcia. Em seguida, discutimos alguns aspectos considerados positivos e negativos da medicalização. Para finalizar, consideramos que enquadrar uma criança em um diagnóstico psiquiátrico apresenta sérias consequências indesejáveis, e acaba sendo mais útil para a sociedade e para o entorno da criança do que para a própria criança.La medicalización de los comportamientos desviantes en la infancia es presentada como una estrategia eficaz para manejar niños que presentan algún tipo de dificultad, sin que, sin embargo, las dificultades de ese proceso sean claramente expuestas. El proceso de medicalización, sin embargo, es complejo y presenta muchos resultados negativos. En ese contexto, nuestro objetivo es reflexionar sobre esas dificultades. Primero, presentamos como se da la relación entre medicalización e infancia. Enseguida, discutimos algunos aspectos considerados positivos y negativos de la medicalización. Para finalizar, consideramos que encuadrar un niño en un diagnóstico psiquiátrico presenta serias consecuencias indeseables, y acaba siendo más útil para la sociedad y para el entorno del niño de lo que para el propio niño.The medicalization of deviant behaviors during childhood is usually presented as an effective strategy to deal with troublesome children, but the problems associated with medicalization are not frequently exposed. Even so, the process of medicalization is complex and may present many negative results. In this

Tuberculosis

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Pablo Latorre Tortello

1998-10-01

Full Text Available Por definición, la tuberculosis pulmonar es la localizaci6n del M. tuberculosis en el tracto respiratorio, la forma más común y principal de la afección y la única capaz de contagiar a otras personas. El M. tuberculosis, descubierto por Robert Koch en 1882, el bacilo de Koch, es un bacilo delgado, inmóvil, de 4 micras de longitud media, aerobio obligado, que se tiñe de rajo por la tinción de Ziehl-Neelsen. Debido a la coraza lipídica de su pared, lo hace resistente a la decoloración con ácidos y alcohol, de ahí el nombre de bacilos ácido-alcohol resistente (BAAR. Su transmisión es directa, de persona a persona.

An unusual class of anthracyclines potentiate Gram-positive antibiotics in intrinsically resistant Gram-negative bacteria.

Science.gov (United States)

Cox, Georgina; Koteva, Kalinka; Wright, Gerard D

2014-07-01

An orthogonal approach taken towards novel antibacterial drug discovery involves the identification of small molecules that potentiate or enhance the activity of existing antibacterial agents. This study aimed to identify natural-product rifampicin adjuvants in the intrinsically resistant organism Escherichia coli. E. coli BW25113 was screened against 1120 actinomycete fermentation extracts in the presence of subinhibitory (2 mg/L) concentrations of rifampicin. The active molecule exhibiting the greatest rifampicin potentiation was isolated using activity-guided methods and identified using mass and NMR spectroscopy. Susceptibility testing and biochemical assays were used to determine the mechanism of antibiotic potentiation. The anthracycline Antibiotic 301A(1) was isolated from the fermentation broth of a strain of Streptomyces (WAC450); the molecule was shown to be highly synergistic with rifampicin (fractional inhibitory concentration index = 0.156) and moderately synergistic with linezolid (FIC index = 0.25) in both E. coli and Acinetobacter baumannii. Activity was associated with inhibition of efflux and the synergistic phenotype was lost when tested against E. coli harbouring mutations within the rpoB gene. Structure-activity relationship studies revealed that other anthracyclines do not synergize with rifampicin and removal of the sugar moiety of Antibiotic 301A(1) abolishes activity. Screening only a subsection of our natural product library identified a small-molecule antibiotic adjuvant capable of sensitizing Gram-negative bacteria to antibiotics to which they are ordinarily intrinsically resistant. This result demonstrates the great potential of this approach in expanding antibiotic effectiveness in the face of the growing challenge of resistance in Gram-negatives. © The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

La «Escala de Balance Afectivo»: Propiedades psicométricas de un instrumento para la medida del afecto positivo y negativo en población española

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D. Godoy-Izquierdo

2008-01-01

Full Text Available El Balance Afectivo se ha propuesto como uno de los componentes, junto con la Satisfacción Vital, del Bienestar Subjetivo. El Balance Afectivo se refiere a las respuestas emocionales de la persona cuando hace juicios valorativos sobre su vida, y es el resultado de la consideración de las emociones tanto positivas como negativas experimentadas a lo largo de un período de tiempo determinado. Este estudio presenta las características de la Escala de Balance Afectivo (EBA (versión española de la escala de Afecto Positivo y Negativo de Warr et al., 1983 en una muestra española adulta obtenida de la población general. METODOLOGÍA: Participaron voluntariamente en este estudio 219 personas con edades comprendidas entre los 18 y 64 años (M= 30.54; dt= 10.79; 62.1% mujeres procedentes de diferentes contextos comunitarios. Los participantes respondieron 4 medidas sobre balance afectivo, competencia personal inespecífica, salud general y satisfacción vital en una única administración. RESULTADOS: Respecto a las propiedades psicométricas de la EBA, las subescalas de Afecto Positivo y Afecto Negativo muestran una elevada consistencia interna, con valores de alfa de Cronbach de 0.82 y 0.75 respectivamente. Sus elementos muestran un adecuado comportamiento que refleja su pertinencia y relevancia para la medida del Balance Afectivo. La estructura factorial arroja un modelo bifactorial perfectamente ajustado a la propuesta teórica. No obstante, dos ítems necesitarían ser reformulados. El análisis de la posible relación entre el afecto positivo y el afecto negativo realizado utilizando un modelo de ecuaciones estructurales apoya la estrecha relación inversa entre ambas dimensiones de la afectividad. La escala muestra una adecuada validez convergente con medidas de competencia personal inespecífica o global, de salud física y mental y de satisfacción vital. CONCLUSIONES: Los resultados de este estudio nos permiten confirmar la EBA como una

Biosorption of mercury by capsulated and slime layerforming Gram ...

African Journals Online (AJOL)

The biosorption of mercury by two locally isolated Gram-ve bacilli: Klebsiella pneumoniae ssp. pneumonia (capsulated) and slime layer forming Pseudomonas aeruginosa, was characterized. Mercury adsorption was found to be influenced by the pH value of the biosorption solution, initial metal concentration, amount of the ...

Trans-generational Immune Priming Protects the Eggs Only against Gram-Positive Bacteria in the Mealworm Beetle

Science.gov (United States)

Dubuffet, Aurore; Zanchi, Caroline; Boutet, Gwendoline; Moreau, Jérôme; Teixeira, Maria; Moret, Yannick

2015-01-01

In many vertebrates and invertebrates, offspring whose mothers have been exposed to pathogens can exhibit increased levels of immune activity and/or increased survival to infection. Such phenomena, called “Trans-generational immune priming” (TGIP) are expected to provide immune protection to the offspring. As the offspring and their mother may share the same environment, and consequently similar microbial threats, we expect the immune molecules present in the progeny to be specific to the microbes that immune challenged the mother. We provide evidence in the mealworm beetle Tenebrio molitor that the antimicrobial activity found in the eggs is only active against Gram-positive bacteria, even when females were exposed to Gram-negative bacteria or fungi. Fungi were weak inducers of TGIP while we obtained similar levels of anti-Gram-positive activity using different bacteria for the maternal challenge. Furthermore, we have identified an antibacterial peptide from the defensin family, the tenecin 1, which spectrum of activity is exclusively directed toward Gram-positive bacteria as potential contributor to this antimicrobial activity. We conclude that maternal transfer of antimicrobial activity in the eggs of T. molitor might have evolved from persistent Gram-positive bacterial pathogens between insect generations. PMID:26430786

Trans-generational Immune Priming Protects the Eggs Only against Gram-Positive Bacteria in the Mealworm Beetle.

Directory of Open Access Journals (Sweden)

Aurore Dubuffet

2015-10-01

Full Text Available In many vertebrates and invertebrates, offspring whose mothers have been exposed to pathogens can exhibit increased levels of immune activity and/or increased survival to infection. Such phenomena, called "Trans-generational immune priming" (TGIP are expected to provide immune protection to the offspring. As the offspring and their mother may share the same environment, and consequently similar microbial threats, we expect the immune molecules present in the progeny to be specific to the microbes that immune challenged the mother. We provide evidence in the mealworm beetle Tenebrio molitor that the antimicrobial activity found in the eggs is only active against Gram-positive bacteria, even when females were exposed to Gram-negative bacteria or fungi. Fungi were weak inducers of TGIP while we obtained similar levels of anti-Gram-positive activity using different bacteria for the maternal challenge. Furthermore, we have identified an antibacterial peptide from the defensin family, the tenecin 1, which spectrum of activity is exclusively directed toward Gram-positive bacteria as potential contributor to this antimicrobial activity. We conclude that maternal transfer of antimicrobial activity in the eggs of T. molitor might have evolved from persistent Gram-positive bacterial pathogens between insect generations.

Bovine mastitis caused by gram negative bacteria in Mosul

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S. Y. A. Al-Dabbagh

2012-01-01

Full Text Available A total of 90 milk samples were collected from cows with clinical and subclinical mastitis from different areas in Mosul city, in a period from October 2009 to June 2010, for the detection of gram negative bacteriological causative agents. The bacteria were identified using morphological, cultural and biochemical characteristics. thirty tow (35.3% gram negative bacterial isolates were obtained from the total count which included 14 isolates (15.5% for Escherichia coli, 7 isolates (7.7% for Klebsiella spp, 4 isolates (4.4% for Pseudomonas aeruginosa, 3 isolates (3.3% for Enterobacter aerogenes ,2 isolates for Serratia marcescens and one isolates (1.1% for each of Aeromonas hydrophila and Pasteurella multocida. Results of antibiotic sensitivity test indicated that most of these isolates were sensitive to Ciprofloxacin following by Gentamycin and Cotrimoxazole, while most of these organisms were resistant to Ampicillin, the isolates showed different percentages of sensitivity to Doxycycline, Tetracycline, Neomycin and Chloramphenicol.

Flow cytometric evaluation of physico-chemical impact on Gram-positive and Gram-negative bacteria

Science.gov (United States)

Fröhling, Antje; Schlüter, Oliver

2015-01-01

Since heat sensitivity of fruits and vegetables limits the application of thermal inactivation processes, new emerging inactivation technologies have to be established to fulfill the requirements of food safety without affecting the produce quality. The efficiency of inactivation treatments has to be ensured and monitored. Monitoring of inactivation effects is commonly performed using traditional cultivation methods which have the disadvantage of the time span needed to obtain results. The aim of this study was to compare the inactivation effects of peracetic acid (PAA), ozonated water (O3), and cold atmospheric pressure plasma (CAPP) on Gram-positive and Gram-negative bacteria using flow cytometric methods. E. coli cells were completely depolarized after treatment (15 s) with 0.25% PAA at 10°C, and after treatment (10 s) with 3.8 mg l−1 O3 at 12°C. The membrane potential of CAPP treated cells remained almost constant at an operating power of 20 W over a time period of 3 min, and subsequently decreased within 30 s of further treatment. Complete membrane permeabilization was observed after 10 s O3 treatment, but treatment with PAA and CAPP did not completely permeabilize the cells within 2 and 4 min, respectively. Similar results were obtained for esterase activity. O3 inactivates cellular esterase but esterase activity was detected after 4 min CAPP treatment and 2 min PAA treatment. L. innocua cells and P. carotovorum cells were also permeabilized instantaneously by O3 treatment at concentrations of 3.8 ± 1 mg l−1. However, higher membrane permeabilization of L. innocua and P. carotovorum than of E. coli was observed at CAPP treatment of 20 W. The degree of bacterial damage due to the inactivation processes is highly dependent on treatment parameters as well as on treated bacteria. Important information regarding the inactivation mechanisms can be obtained by flow cytometric measurements and this enables the definition of critical process parameters. PMID

Flow cytometric evaluation of physico-chemical impact on Gram-positive and Gram-negative bacteria

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Antje eFröhling

2015-09-01

Full Text Available Since heat sensitivity of fruits and vegetables limits the application of thermal inactivation processes, new emerging inactivation technologies have to be established to fulfil the requirements of food safety without affecting the produce quality. The efficiency of inactivation treatments has to be ensured and monitored. Monitoring of inactivation effects is commonly performed using traditional cultivation methods which have the disadvantage of the time span needed to obtain results.The aim of this study was to compare the inactivation effects of peracetic acid (PAA, ozonated water (O3 and cold atmospheric pressure plasma (CAPP on Gram-positive and Gram-negative bacteria using flow cytometric methods. E. coli cells were completely depolarized after treatment (15 s with 0.25 % PAA at 10 °C, and after treatment (10 s with 3.8 mg l-1 O3 at 12°C. The membrane potential of CAPP treated cells remained almost constant at an operating power of 20 W over a time period of 3 min, and subsequently decreased within 30 s of further treatment. Complete membrane permeabilization was observed after 10 s O3 treatment, but treatment with PAA and CAPP did not completely permeabilize the cells within 2 min and 4 min, respectively. Similar results were obtained for esterase activity. O3 inactivates cellular esterase but esterase activity was detected after 4 min CAPP treatment and 2 min PAA treatment. L. innocua cells and P. carotovorum cells were also permeabilized instantaneously by O3 treatment at concentrations of 3.8 ± 1 mg l-1. However, higher membrane permeabilization of L. innocua and P. carotovorum than of E. coli was observed at CAPP treatment of 20 W. The degree of bacterial damage due to the inactivation processes is highly dependent on treatment parameters as well as on treated bacteria. Important information regarding the inactivation mechanisms can be obtained by flow cytometric measurements and this enables the definition of critical process

Adesão de pacientes HIV positivos à dietoterapia ambulatorial Adherence of positive HIV patients to ambulatory diet therapy

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Késia Diego Quintaes

1999-08-01

Full Text Available É conhecida a importância do estado nutricional para a evolução clínica de pacientes HIV positivos. Entretanto, é desconhecida a expectativa do paciente com relação à dietoterapia. Por um período de 30 semanas foram acompanhados 50,0% dos pacientes HIV positivo (grupos II e IV atendidos pelo ambulatório de Doenças Sexualmente Transmissíveis do Hospital e Maternidade Celso Pierro. Neste período foram realizadas duas entrevistas, sendo o intervalo entre elas de 10 semanas. Na primeira foram colhidos dados socioeconômicos, antropométricos, verificadas as modificações voluntárias feitas na alimentação e também a expectativa do paciente quanto a este tipo de tratamento. Na segunda foram colhidos indicadores diretos e indiretos de adesão ao tratamento. A adesão foi maior entre os pacientes do grupo IV (64,7% do que entre os do grupo II (35,3%. No entanto, 81,3% dos pacientes do grupo II, após tomarem conhecimento da sorologia positiva para HIV, modificaram voluntariamente sua alimentação, demostrando ser este um importante período para sensibilização do paciente para o tratamento.It's well known the importance of nutritional status to the clinical evolution of positive HIV patients. However, the patient expectation in relation to diet therapy is unknown. During 30 weeks, 50.0% of the patients HIV positive (groups II and IV attended by the ambulatory of Sexually Transmitted Diseases of Hospital and Maternity Celso Pierro, were interviewed. In this period two interviews with an interval of ten weeks were carried out. At the first one socioeconomic and anthropometric data were collected voluntary feeding modifications and also the patient expectation about such treatment were verified. At the second one, direct and indirect indicators of the adherence to treatment were colleded. The adherence was greater in pacients of group IV (64.7% than in group II (35.3%. However, 81.3% of the patients from group II, after being aware

Polymers for binding of the gram-positive oral pathogen Streptococcus mutans

Science.gov (United States)

Magennis, Eugene P.; Francini, Nora; Mastrotto, Francesca; Catania, Rosa; Redhead, Martin; Fernandez-Trillo, Francisco; Bradshaw, David; Churchley, David; Winzer, Klaus; Alexander, Cameron

2017-01-01

Streptococcus mutans is the most significant pathogenic bacterium implicated in the formation of dental caries and, both directly and indirectly, has been associated with severe conditions such as multiple sclerosis, cerebrovascular and peripheral artery disease. Polymers able to selectively bind S. mutans and/or inhibit its adhesion to oral tissue in a non-lethal manner would offer possibilities for addressing pathogenicity without selecting for populations resistant against bactericidal agents. In the present work two libraries of 2-(dimethylamino)ethyl methacrylate (pDMAEMA)-based polymers were synthesized with various proportions of either N,N,N-trimethylethanaminium cationic- or sulfobetaine zwitterionic groups. These copolymers where initially tested as potential macromolecular ligands for S. mutans NCTC 10449, whilst Escherichia coli MG1655 was used as Gram-negative control bacteria. pDMAEMA-derived materials with high proportions of zwitterionic repeating units were found to be selective for S. mutans, in both isolated and S. mutans–E. coli mixed bacterial cultures. Fully sulfobetainized pDMAEMA was subsequently found to bind/cluster preferentially Gram-positive S. mutans and S. aureus compared to Gram negative E. coli and V. harveyi. A key initial stage of S. mutans pathogenesis involves a lectin-mediated adhesion to the tooth surface, thus the range of potential macromolecular ligands was further expanded by investigating two glycopolymers bearing α-mannopyranoside and β-galactopyranoside pendant units. Results with these polymers indicated that preferential binding to either S. mutans or E. coli can be obtained by modulating the glycosylation pattern of the chosen multivalent ligands without incurring unacceptable cytotoxicity in a model gastrointestinal cell line. Overall, our results allowed to identify a structure–property relationship for the potential antimicrobial polymers investigated, and suggest that preferential binding to Gram-positive S

Evaluación económica del trastuzumab como tratamiento adyuvante en cáncer de mama HER2- positivo en Colombia

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Jefferson Antonio Buendía

2013-09-01

Full Text Available Introducción. El trastuzumab es un anticuerpo monoclonal de reconocida efectividad para el tratamiento en mujeres con cáncer de mama positivo para HER2. Sin embargo, la mayoría de estudios de costo-efectividad se han llevado a cabo en países desarrollados. Objetivo. Determinar el costo-efectividad del tratamiento adyuvante con trastuzumab en mujeres concáncer de mama HER2+ en Colombia. Materiales y métodos. Se construyó un modelo de Markov, con ciclos de transición anuales y desde la perspectiva del pagador, para estimar los resultados clínicos y económicos derivados de la administración de trastuzumab en mujeres con HER2 positivo. El modelo incorpora cinco estados de transición: libre de enfermedad, recurrencia local, metástasis, falla cardiaca y muerte. La tasa de eventos y la razón de tazas instantáneas (0,51; IC95% 0,44-0,59; p<0,0001 se derivaron del reporte a cuatro años de los ensayos clínicos controlados N9831 y NSABP B-31. Los costos y las utilidades se estimados a partir de la literatura científica, utilizando una tasa de descuento del 5 % anual. Resultados. El modelo revela que la utilización de trastuzumab como tratamiento adyuvante prolongala expectativa de vida ajustada por calidad en 0,8 años, en comparación con la quimioterapia sin trastuzumab; a una razón de costo efectividad incremental (sic. de US$ 71.491 por año de vida ganado ajustado por calidad de vida. Conclusión. El tratamiento con trastuzumab durante un año no es costo-efectivo en Colombia, utilizando la definición de costo-efectividad de la OMS de menos de dos a tres veces el PIB per cápita por año de vida ganado ajustado por calidad de vida. doi: http://dx.doi.org/10.7705/biomedica.v33i3.832

Curative Treatment of Severe Gram-Negative Bacterial Infections by a New Class of Antibiotics Targeting LpxC.

Science.gov (United States)

Lemaître, Nadine; Liang, Xiaofei; Najeeb, Javaria; Lee, Chul-Jin; Titecat, Marie; Leteurtre, Emmanuelle; Simonet, Michel; Toone, Eric J; Zhou, Pei; Sebbane, Florent

2017-07-25

The infectious diseases caused by multidrug-resistant bacteria pose serious threats to humankind. It has been suggested that an antibiotic targeting LpxC of the lipid A biosynthetic pathway in Gram-negative bacteria is a promising strategy for curing Gram-negative bacterial infections. However, experimental proof of this concept is lacking. Here, we describe our discovery and characterization of a biphenylacetylene-based inhibitor of LpxC, an essential enzyme in the biosynthesis of the lipid A component of the outer membrane of Gram-negative bacteria. The compound LPC-069 has no known adverse effects in mice and is effective in vitro against a broad panel of Gram-negative clinical isolates, including several multiresistant and extremely drug-resistant strains involved in nosocomial infections. Furthermore, LPC-069 is curative in a murine model of one of the most severe human diseases, bubonic plague, which is caused by the Gram-negative bacterium Yersinia pestis Our results demonstrate the safety and efficacy of LpxC inhibitors as a new class of antibiotic against fatal infections caused by extremely virulent pathogens. The present findings also highlight the potential of LpxC inhibitors for clinical development as therapeutics for infections caused by multidrug-resistant bacteria. IMPORTANCE The rapid spread of antimicrobial resistance among Gram-negative bacilli highlights the urgent need for new antibiotics. Here, we describe a new class of antibiotics lacking cross-resistance with conventional antibiotics. The compounds inhibit LpxC, a key enzyme in the lipid A biosynthetic pathway in Gram-negative bacteria, and are active in vitro against a broad panel of clinical isolates of Gram-negative bacilli involved in nosocomial and community infections. The present study also constitutes the first demonstration of the curative treatment of bubonic plague by a novel, broad-spectrum antibiotic targeting LpxC. Hence, the data highlight the therapeutic potential of Lpx

Curative Treatment of Severe Gram-Negative Bacterial Infections by a New Class of Antibiotics Targeting LpxC

Energy Technology Data Exchange (ETDEWEB)

Lemaître, Nadine; Liang, Xiaofei; Najeeb, Javaria; Lee, Chul-Jin; Titecat, Marie; Leteurtre, Emmanuelle; Simonet, Michel; Toone, Eric J.; Zhou, Pei; Sebbane, Florent; Nacy, Carol A.

2017-07-25

The infectious diseases caused by multidrug-resistant bacteria pose serious threats to humankind. It has been suggested that an antibiotic targeting LpxC of the lipid A biosynthetic pathway in Gram-negative bacteria is a promising strategy for curing Gram-negative bacterial infections. However, experimental proof of this concept is lacking. Here, we describe our discovery and characterization of a biphenylacetylene-based inhibitor of LpxC, an essential enzyme in the biosynthesis of the lipid A component of the outer membrane of Gram-negative bacteria. The compound LPC-069 has no known adverse effects in mice and is effectivein vitroagainst a broad panel of Gram-negative clinical isolates, including several multiresistant and extremely drug-resistant strains involved in nosocomial infections. Furthermore, LPC-069 is curative in a murine model of one of the most severe human diseases, bubonic plague, which is caused by the Gram-negative bacteriumYersinia pestis. Our results demonstrate the safety and efficacy of LpxC inhibitors as a new class of antibiotic against fatal infections caused by extremely virulent pathogens. The present findings also highlight the potential of LpxC inhibitors for clinical development as therapeutics for infections caused by multidrug-resistant bacteria.

IMPORTANCEThe rapid spread of antimicrobial resistance among Gram-negative bacilli highlights the urgent need for new antibiotics. Here, we describe a new class of antibiotics lacking cross-resistance with conventional antibiotics. The compounds inhibit LpxC, a key enzyme in the lipid A biosynthetic pathway in Gram-negative bacteria, and are activein vitroagainst a broad panel of clinical isolates of Gram-negative bacilli involved in nosocomial and community infections. The present study also constitutes the first demonstration of the curative treatment of bubonic plague by a novel, broad

A sustainable process for gram-scale synthesis of stereoselective ...

Indian Academy of Sciences (India)

RAJAN ABRAHAM

2018-02-07

Feb 7, 2018 ... for the additional structure modification.17–20. Acrylic acid derivatives ... mild conditions, and application in synthesizing bio- logically ... cal process for the gram-scale synthesis of streoselective ... ate yield of desired product 2 (58%, Table 1, entry. 2). .... Cross-Coupling and Atom-Economic Addition Reac-.

Resistencia a antimicrobianos de bacilos Gram negativos aislados en unidades de cuidado intensivo en hospitales de Colombia, WHONET 2003, 2004 y 2005

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María Consuelo Miranda

2006-09-01

Resultados. Los altos porcentajes de resistencia reportados en especial para A. baumannii, corroboraron la presencia de bacterias multirresistentes en las UCI en las instituciones participantes durante el periodo de estudio. Conclusiones. Es urgente crear una red nacional de vigilancia de la resistencia a antimicrobianos de los patógenos hospitalarios y de esta manera mejorar nuestra habilidad para detectar, supervisar y manejar la resistencia a antimicrobianos en Colombia.

[Characteristic of clinical strains of gram-negative obligate anaerobes].

Science.gov (United States)

Kadzielska, Joanna; Kierzkowska, Marta; Sawicka-Grzelak, Anna; Rokosz, Alicja; Łuczak, Mirosław

2007-01-01

The aim of the study was to assess prevalence and antibiotic susceptibility profiles ofGram-negative strictly anaerobic bacteria isolated from clinical specimens taken from hospitalized patients in 2005-2006. Biochemical identification and antibiotic susceptibility were done in an automated system ATB Expression (bioMerieux sa). From 12262 specimens examined 867 strains of obligate anaerobes were isolated. Gram-negative strictly anaerobic bacteria were cultured in number of 138 strains (15,9%). All cultures were performed on Columbia agar and Schaedler agar media (bioMerieux sa) supplemented with 5% sheep blood and incubated at 37 degrees C for 48-120 h in 85% N2, 10% H2, 5% CO2. Most frequently isolated was Bacteroides spp. (41,3%). For this group beta-lactamase activity was evaluated by using nitrocefin disc test (Cefinase BBL, Becton Dickinson and Co., Cockeysville, MD, USA). Production of ESBLs was detected with the use of two disc diffusion methods: the double-disc synergy test (DDST) according to Jarlier et al. and the diagnostic disc (DD) test according to Appleton. ESBLs were produced by 5,3% strains of Bacteroides spp. For all Bacteroides spp. strains MIC values were determined by gradient diffusion method Etest (AB BIODISK, Sweden). ESBLs and MIC were performed on Wilkins-Chalgren solid medium supplemented with 5% sheep blood (Difco Lab., USA) and all plates were incubated at 35 degrees C for 48 hours in 85% N2, 10% H2, 5% CO2. Most Gram-negative obligate anaerobes isolated from clinical specimens are still susceptible to imipenem (100%), metronidazole (99,3%) and beta-lactam antibiotics with beta-lactamase inhibitors: piperacillin/tazobactam (99,3%), ticarcillin/clavulanate (99.3%), amoxicillin/clavulanate (97.8%).

Análise do efeito de contingências de reforçamento positivo e controle aversivo sobre resposta de aritmética de crianças

OpenAIRE

Azevedo, Patrícia Nogueira

2015-01-01

Planejar contingências de reforçamento no contexto escolar envolve uma série de variáveis que devem ser analisadas e levadas em consideração. Para tanto, investir na análise de contingências que produzam ensino efetivo que possa auxiliar professores no exercício de sua função torna-se imprescindível. Este trabalho teve o objetivo de investigar os efeitos de contingências de reforçamento positivo e de punição/reforçamento negativo sobre o responder de crianças em atividades de a...

Indicações e achados das colonoscopias nos doentes HIV-positivo: comparação com soronegativos Indications and results of colonoscopies in HIV-positive patients: comparison with seronegative patients

Directory of Open Access Journals (Sweden)

Carmen Ruth Manzione

2007-03-01

Full Text Available Embora as indicações da colonoscopia sejam semelhantes em doentes HIV-positivo, quando comparados aos soronegativos, os achados e as suas incidências parecem diferir, sendo alguns deles mais específicos para o grupo dos imunodeprimidos. OBJETIVO: Avaliar as indicações e os achados das colonoscopias comparando os doentes soropositivos com os soronegativos para o HIV. Realizamos 1909 exames entre 1997 e 2005, sendo 1341 HIV-negativo (771 mulheres e 570 homens com média etária de 51,2 anos e 568 HIV-positivo (137 mulheres e 431 homens com 34,4 anos, em média. A análise estatística dos dados estudados revelou haver mais exames em homens no grupo HIV-positivo e em mulheres entre os soronegativos. O grupo mais jovem foi o dos soropositivos. Houve mais indicações devidas a enterorragia (22,1% e dor abdominal (12,7% nos pacientes soronegativos, e diarréia crônica (45,9% entre os soropositivos. As colites e os tumores foram os achados mais comuns em pacientes HIV-positivo e a moléstia diverticular e os pólipos, os mais freqüentes entre os soronegativos. O tumor predominante nos soronegativos foi o adenocarcinoma, enquanto que entre os soropositivos foi o sarcoma de Kaposi. CONCLUSÃO: A comparação entre os grupos demonstrou haver diferenças com relação ao sexo, idade e algumas indicações. Os achados foram semelhantes, embora com freqüências distintas.Although colonoscopy indications are similar in HIV-positive patients when compared to sero-negative persons, the findings and their incidences seem to be different, and some are more specific to immunosuppressed patients. The aim of this study is to evaluate indications and findings of colonoscopies comparing patients, sero-negatives and sero-positives to HIV. We performed 1909 colonoscopies from 1997 to 2005, 1341 in HIV-negative persons (771 females and 570 males with mean age of 51.2 years old and 568 in HIV-positive people (137 females and 431 males with mean age of 34.4 years

Development and transmission of antimicrobial resistance among Gram-negative bacteria in animals and their public health impact.

Science.gov (United States)

Mukerji, Shewli; O'Dea, Mark; Barton, Mary; Kirkwood, Roy; Lee, Terence; Abraham, Sam

2017-02-28

Gram-negative bacteria are known to cause severe infections in both humans and animals. Antimicrobial resistance (AMR) in Gram-negative bacteria is a major challenge in the treatment of clinical infections globally due to the propensity of these organisms to rapidly develop resistance against antimicrobials in use. In addition, Gram-negative bacteria possess highly efficient mechanisms through which the AMR can be disseminated between pathogenic and commensal bacteria of the same or different species. These unique traits of Gram-negative bacteria have resulted in evolution of Gram-negative bacterial strains demonstrating resistance to multiple classes of antimicrobials. The evergrowing resistance issue has not only resulted in limitation of treatment options but also led to increased treatment costs and mortality rates in humans and animals. With few or no new antimicrobials in production to combat severe life-threatening infections, AMR has been described as the one of the most severe, long-term threats to human health. Aside from overuse and misuse of antimicrobials in humans, another factor that has exacerbated the emergence of AMR in Gram-negative bacteria is the veterinary use of antimicrobials that belong to the same classes considered to be critically important for treating serious life-threatening infections in humans. Despite the fact that development of AMR dates back to before the introduction of antimicrobials, the recent surge in the resistance towards all available critically important antimicrobials has emerged as a major public health issue. This review thus focuses on discussing the development, transmission and public health impact of AMR in Gram-negative bacteria in animals. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

Inactivation dynamics of 222 nm krypton-chlorine excilamp irradiation on Gram-positive and Gram-negative foodborne pathogenic bacteria.

Science.gov (United States)

Kang, Jun-Won; Kim, Sang-Soon; Kang, Dong-Hyun

2018-07-01

The object of this study was to elucidate the bactericidal mechanism of a 222 nm Krypton Chlorine (KrCl) excilamp compared with that of a 254 nm Low Pressure mercury (LP Hg) lamp. The KrCl excilamp had higher bactericidal capacity against Gram-positive pathogenic bacteria (Staphylococcus aureus and L. monocytogenes) and Gram-negative pathogenic bacteria (S. Typhimurium and E. coli O157:H7) than did the LP Hg lamp when cell suspensions in PBS were irradiated with each type of UV lamp. It was found out that the KrCl excilamp induced cell membrane damage as a form of depolarization. From the study of respiratory chain dehydrogenase activity and the lipid peroxidation assay, it was revealed that cell membrane damage was attributed to inactivation of enzymes related to generation of membrane potential and occurrence of lipid peroxidation. Direct absorption of UV radiation which led to photoreaction through formation of an excited state was one of the causes inducing cell damage. Additionally, generation of ROS and thus occurrence of secondary damage can be another cause. The LP Hg lamp only induced damage to DNA but not to other components such as lipids or proteins. This difference was derived from differences of UV radiation absorption by cellular materials. Copyright © 2018 Elsevier Ltd. All rights reserved.

Patterns of Gram-stained fecal flora as a quick diagnostic marker in patients with severe SIRS.

Science.gov (United States)

Shimizu, Kentaro; Ogura, Hiroshi; Tomono, Kazunori; Tasaki, Osamu; Asahara, Takashi; Nomoto, Koji; Morotomi, Masami; Matsushima, Asako; Nakahori, Yasutaka; Yamano, Shuhei; Osuka, Akinori; Kuwagata, Yasuyuki; Sugimoto, Hisashi

2011-06-01

The gut is an important target organ of injury during critically ill conditions. Although Gram staining is a common and quick method for identifying bacteria, its clinical application has not been fully evaluated in critically ill conditions. This study's aims were to identify patterns of Gram-stained fecal flora and compare them to cultured bacterial counts and to investigate the association between the patterns and septic complications in patients with severe systemic inflammatory response syndrome (SIRS). Fifty-two patients with SIRS were included whose Gram-stained fecal flora was classified into three patterns. In a diverse pattern, large numbers of multiple kinds of bacteria completely covered the field. In a single pattern, one specific kind of bacteria or fungi predominantly covered the field. In a depleted pattern, most bacteria were diminished in the field. In the analysis of fecal flora, the numbers of total obligate anaerobes in the depleted pattern was significantly lower than those in the diverse pattern and single pattern (p Gram-stained fecal flora can be classified into three patterns and are associated with both cultured bacterial counts and clinical information. Gram-stained fecal bacteria can be used as a quick bedside diagnostic marker for severe SIRS patients.

Endocarditis por Brucella canis: primer caso documentado en un paciente adulto en Argentina Brucella canis endocarditis: first documented case in Argentina

Directory of Open Access Journals (Sweden)

Valeria Manias

2013-03-01

Full Text Available Se describe el primer caso documentado de endocarditis por Brucella canis en Argentina. El paciente fue un varón adulto que consultó por edemas en miembros inferiores, registros febriles aislados de 2 meses de evolución y dolor precordial opresivo que irradiaba a brazo izquierdo. Negaba contacto con animales de cría o consumo de productos sin pasteurización. Estudios cardiológicos constataron endocarditis infecciosa. Se resuelve cirugía de recambio valvular ante fracaso terapéutico empírico con cefalotina, ampicilina y gentamicina. Los hemocultivos fueron positivos (4 de 4 muestras con bacilos gram negativos. Se realizó la identificación con técnica API 20 NE (bioMérieux, el método automatizado Phoenix (BD y las pruebas bioquímicas convencionales, sin concluir género ni especie. Se derivó la cepa al departamento de Bacteriología Especial INEI-ANLIS "Dr. Carlos G. Malbrán" donde se identificó al aislamiento como Brucella canis. Se rotó el esquema terapéutico a doxiciclina, rifampicina y trimetoprima-sulfametoxazol con buena evolución. La importancia del caso radica en la posible falla del tratamiento antimicrobiano empírico administrado para endocarditis, ya que B. canis no responde a los antimicrobianos convencionales para esta patología.We herein present the case of an adult male patient who consulted for lower extremity edema, a 2- month history of fever and oppressive chest pain radiating to the left arm. He referred neither contact with breeding animals nor consumption of unpasteurized dairy products. A diagnosis of endocarditis was confirmed by cardiac studies. Since the empirical treatment with cephalotin, ampicillin and gentamicin failed, the patient underwent aortic valve replacement. A total of four blood cultures were positive with a gram-negative rod. Bacterial identification was performed using the API 20 NE technique (bioMerieux, the Phoenix automated method (BD and conventional biochemical tests which were

Blood culture gram stain, acridine orange stain and direct sensitivity-based antimicrobial therapy of bloodstream infection in patients with trauma.

Science.gov (United States)

Behera, B; Mathur, P; Gupta, B

2010-01-01

The purpose of this study was to ascertain if the simple practice of Gram stain, acridine orange stain and direct sensitivity determination of positive blood culture bottles could be used to guide early and appropriate treatment in trauma patients with clinical suspicion of sepsis. The study also aimed to evaluate the error in interpreting antimicrobial sensitivity by direct method when compared to standard method and find out if specific antibiotic-organism combination had more discrepancies. Findings from consecutive episodes of blood stream infection at an Apex Trauma centre over a 12-month period are summarized. A total of 509 consecutive positive blood cultures were subjected to Gram staining. AO staining was done in BacT/ALERT-positive Gram-stain negative blood cultures. Direct sensitivity was performed from 369 blood culture broths, showing single type of growth in Gram and acridine orange staining. Results of direct sensitivity were compared to conventional sensitivity for errors. No 'very major' discrepancy was found in this study. About 5.2 and 1.8% minor error rates were noted in gram-positive and gram-negative bacteria, respectively, while comparing the two methods. Most of the discrepancies in gram-negative bacteria were noted in beta lactam - beta lactamase inhibitor combinations. Direct sensitivity testing was not reliable for reporting of methicillin and vancomycin resistance in Staphylococci. Gram stain result together with direct sensitivity testing is required for optimizing initial antimicrobial therapy in trauma patients with clinical suspicion of sepsis. Gram staining and AO staining proved particularly helpful in the early detection of candidaemia.

leaves extracts as counter stain in gram staining reaction 56

African Journals Online (AJOL)

DR. AMINU

is a stain with color contrasting to the principal stain, making the stained ... technology today, the Gram's staining method remains ... was aimed at employing the use of Henna leaves extract as ... fragrant, white or rose flowers in clusters. It is.

Non-oral gram-negative facultative rods in chronic periodontitis microbiota

NARCIS (Netherlands)

van Winkelhoff, Arie J; Rurenga, Patrick; Wekema-Mulder, Gepke J; Singadji, Zadnach; Rams, Thomas E

OBJECTIVE: The subgingival prevalence of gram-negative facultative rods not usually inhabiting or indigenous to the oral cavity (non-oral GNFR), as well as selected periodontal bacterial pathogens, were evaluated by culture in untreated and treated chronic periodontitis patients. METHODS:

Restriction of cephalosporins and control of extended spectrum beta-lactamase producing gram negative bacteria in a neonatal intensive care unit.

Science.gov (United States)

Murki, Srinivas; Jonnala, Sravanthi; Mohammed, Faheemuddin; Reddy, Anupama

2010-09-01

This interventional study with historical controls was conducted to study the effect of cephalosporin restriction on the incidence of extended spectrum beta-lactamase (ESBL) gram negative infections in neonates admitted to intensive care unit. All gram negative isolates from the blood were evaluated for beta lactamase production. The incidence of ESBL production was compared before (year 2007) and after cephalosporin restriction (year 2008). Thirty two neonates (3% of NICU admissions) in the year 2007 and fifty six (5.2%) in the year 2008, had gram negative septicemia. The incidence of ESBL gram negatives decreased by 22% (47% to 25%, P=0.03). Restriction of all class of cephalosporins significantly decreased the incidence of ESBL gram negative infections.

Electrochemical reduction of oxygen catalyzed by a wide range of bacteria including Gram-positive

Energy Technology Data Exchange (ETDEWEB)

Cournet, Amandine [Universite de Toulouse, UPS, LU49, Adhesion Bacterienne et Formation de Biofilms, 35 chemin des Maraichers, 31 062 Toulouse cedex 09 (France); Laboratoire de Genie Chimique CNRS, Universite de Toulouse, 4 allee Emile Monso, BP 84234, 31432 Toulouse cedex 04 (France); Delia, Marie-Line; Bergel, Alain [Laboratoire de Genie Chimique CNRS, Universite de Toulouse, 4 allee Emile Monso, BP 84234, 31432 Toulouse cedex 04 (France); Roques, Christine; Berge, Mathieu [Universite de Toulouse, UPS, LU49, Adhesion Bacterienne et Formation de Biofilms, 35 chemin des Maraichers, 31 062 Toulouse cedex 09 (France)

2010-04-15

Most bacteria known to be electrochemically active have been harvested in the anodic compartments of microbial fuel cells (MFCs) and are able to use electrodes as electron acceptors. The reverse phenomenon, i.e. using solid electrodes as electron donors, is not so widely studied. To our knowledge, most of the electrochemically active bacteria are Gram-negative. The present study implements a transitory electrochemical technique (cyclic voltammetry) to study the microbial catalysis of the electrochemical reduction of oxygen. It is demonstrated that a wide range of aerobic and facultative anaerobic bacteria are able to catalyze oxygen reduction. Among these electroactive bacteria, several were Gram-positive. The transfer of electrons was direct since no activity was obtained with the filtrate. These findings, showing a widespread property among bacteria including Gram-positive ones, open new and interesting routes in the field of electroactive bacteria research. (author)

Exact closed-form expression for the inverse moments of one-sided correlated Gram matrices

KAUST Repository

Elkhalil, Khalil

2016-08-15

In this paper, we derive a closed-form expression for the inverse moments of one sided-correlated random Gram matrices. Such a question is mainly motivated by applications in signal processing and wireless communications for which evaluating this quantity is a question of major interest. This is for instance the case of the best linear unbiased estimator, in which the average estimation error corresponds to the first inverse moment of a random Gram matrix.

Exact closed-form expression for the inverse moments of one-sided correlated Gram matrices

KAUST Repository

Elkhalil, Khalil; Kammoun, Abla; Al-Naffouri, Tareq Y.; Alouini, Mohamed-Slim

2016-01-01

In this paper, we derive a closed-form expression for the inverse moments of one sided-correlated random Gram matrices. Such a question is mainly motivated by applications in signal processing and wireless communications for which evaluating this quantity is a question of major interest. This is for instance the case of the best linear unbiased estimator, in which the average estimation error corresponds to the first inverse moment of a random Gram matrix.

Surface-Exposed Lipoproteins: An Emerging Secretion Phenomenon in Gram-Negative Bacteria.

Science.gov (United States)

Wilson, Marlena M; Bernstein, Harris D

2016-03-01

Bacterial lipoproteins are hydrophilic proteins that are anchored to a cell membrane by N-terminally linked fatty acids. It is widely believed that nearly all lipoproteins produced by Gram-negative bacteria are either retained in the inner membrane (IM) or transferred to the inner leaflet of the outer membrane (OM). Lipoproteins that are exposed on the cell surface have also been reported but are generally considered to be rare. Results from a variety of recent studies, however, now suggest that the prevalence of surface-exposed lipoproteins has been underestimated. In this review we describe the evidence that the surface exposure of lipoproteins in Gram-negative bacteria is a widespread phenomenon and discuss possible mechanisms by which these proteins might be transported across the OM. Published by Elsevier Ltd.

Aluminium-induced excessive ROS causes cellular damage and metabolic shifts in black gram Vigna mungo (L.) Hepper.

Science.gov (United States)

Chowra, Umakanta; Yanase, Emiko; Koyama, Hiroyuki; Panda, Sanjib Kumar

2017-01-01

Aluminium-induced oxidative damage caused by excessive ROS production was evaluated in black gram pulse crop. Black gram plants were treated with different aluminium (Al 3+ ) concentrations (10, 50 and 100 μM with pH 4.7) and further the effects of Al 3+ were characterised by means of root growth inhibition, histochemical assay, ROS content analysis, protein carbonylation quantification and 1 H-NMR analysis. The results showed that aluminium induces excessive ROS production which leads to cellular damage, root injury, stunt root growth and other metabolic shifts. In black gram, Al 3+ induces cellular damage at the earliest stage of stress which was characterised from histochemical analysis. From this study, it was observed that prolonged stress can activate certain aluminium detoxification defence mechanism. Probably excessive ROS triggers such defence mechanism in black gram. Al 3+ can induce excessive ROS initially in the root region then transported to other parts of the plant. As much as the Al 3+ concentration increases, the rate of cellular injury and ROS production also increases. But after 72 h of stress, plants showed a lowered ROS level and cellular damage which indicates the upregulation of defensive mechanisms. Metabolic shift analysis also showed that the black gram plant under stress has less metabolic content after 24 h of treatment, but gradually, it was increased after 72 h of treatment. It was assumed that ROS played the most important role as a signalling molecule for aluminium stress in black gram.

Doripenem: an expected arrival in the treatment of infections caused by multidrug-resistant Gram-negative pathogens.

Science.gov (United States)

Poulakou, Garyphallia; Giamarellou, Helen

2008-05-01

Potent new drugs against multidrug-resistant Gram-negative bacteria, namely Pseudomonas aeruginosa and Acinetobacter spp. and pan-drug-resistant Klebsiella pneumoniae, which constitute an increasing medical threat, are almost absent from the future pharmaceutical pipeline. This drug evaluation focuses on the position of doripenem, a novel forthcoming carbapenem. Mechanisms of resistance and new drugs with anti-Gram-negative activity are also briefly reviewed. Literature search was performed for new carbapenems, new antibiotics, doripenem, metallo-beta-lactamase inhibitors, multidrug-resistant pathogens, antipseudomonal antibiotics and multidrug-resistant epidemiology. Doripenem possesses a broad spectrum of activity against Gram-negative bacteria, similar to that of meropenem, while retaining the spectrum of imipenem against Gram-positive pathogens. Against P. aeruginosa, doripenem exhibits rapid bactericidal activity with 2 - 4-fold lower MIC values, compared to meropenem. Exploitation of pharmacokinetic/pharmacodynamic applications could offer a treatment opportunity against strains exhibiting borderline resistance to doripenem. Stability against numerous beta-lactamases, low adverse event potential and more potent in vitro antibacterial activity against P. aeruginosa and A. baumanni compared to the existing carbapenems, are its principal features.

Integrating rapid diagnostics and antimicrobial stewardship improves outcomes in patients with antibiotic-resistant Gram-negative bacteremia.

Science.gov (United States)

Perez, Katherine K; Olsen, Randall J; Musick, William L; Cernoch, Patricia L; Davis, James R; Peterson, Leif E; Musser, James M

2014-09-01

An intervention for Gram-negative bloodstream infections that integrated mass spectrometry technology for rapid diagnosis with antimicrobial stewardship oversight significantly improved patient outcomes and reduced hospital costs. As antibiotic resistance rates continue to grow at an alarming speed, the current study was undertaken to assess the impact of this intervention in a challenging patient population with bloodstream infections caused by antibiotic-resistant Gram-negative bacteria. A total of 153 patients with antibiotic-resistant Gram-negative bacteremia hospitalized prior to the study intervention were compared to 112 patients treated post-implementation. Outcomes assessed included time to optimal antibiotic therapy, time to active treatment when inactive, hospital and intensive care unit length of stay, all-cause 30-day mortality, and total hospital expenditures. Integrating rapid diagnostics with antimicrobial stewardship improved time to optimal antibiotic therapy (80.9 h in the pre-intervention period versus 23.2 h in the intervention period, P Gram-negatives. The intervention decreased hospital and intensive care unit length of stay, total hospital costs, and reduced all-cause 30-day mortality. Copyright © 2014. Published by Elsevier Ltd.

Development and quality evaluation of hypoallergic complementary foods from rice incorporated with sprouted green gram flour

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Rafiya Bazaz

2016-12-01

Full Text Available Rice flour and green gram flour (sprouted as well as unsprouted were blended in different proportions with apple pulp, sugar, milk and water for formulation of 12 hypoallergic diets. The formulations were studied for physico-chemical properties, antinutrient content (phytate and oxalate and in vitro protein digestibility. Blending and sprouting significantly affected all the studied parameters. Sprouting significantly (p ≤ 0.05 improved protein content and in vitro protein digestibility, while carbohydrate content and antinutrients decreased significantly. Nutrition profile of water-based diets met RDA guidelines only after addition of sprouted green gram flour and were comparable to control (commercial weaning food. Water-based formulation showed lower sensory score than milk-based diets; however, addition of sprouted green gram flour significantly (p ≤ 0.05 improved their overall acceptability. It could be concluded that by incorporating sprouted green gram flour, milk could be replaced with water for production of hypoallergic weaning foods without affecting the nutritional and sensory attributes of formulations and thereby making the production more economical, especially for underdeveloped countries.

Gram-negative bacteria account for main differences between faecal microbiota from patients with ulcerative colitis and healthy controls

DEFF Research Database (Denmark)

Vigsnæs, Louise Kristine; Brynskov, J.; Steenholdt, C.

2012-01-01

process of the gut mucosa. The aim of this study was to investigate the faecal microbiota in patients either with UC in remission (n=6) or with active disease (n=6), and in healthy controls (n=6). The composition of Gram-negative bacteria and Gram-positive bacteria was examined. Antigenic structures...... of Gram-negative bacteria such as lipopolysaccharides have been related to the inflammatory responses and pathogenesis of inflammatory bowel disease. Dice cluster analysis and principal component analysis of faecal microbiota profiles obtained by denaturing gradient gel electrophoresis and quantitative...... PCR, respectively, revealed that the composition of faecal bacteria from UC patients with active disease differed from the healthy controls and that this difference should be ascribed to Gram-negative bacteria. The analysis did not show any clear grouping of UC patients in remission. Even...

Curative Treatment of Severe Gram-Negative Bacterial Infections by a New Class of Antibiotics Targeting LpxC

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Nadine Lemaître

2017-07-01

Full Text Available The infectious diseases caused by multidrug-resistant bacteria pose serious threats to humankind. It has been suggested that an antibiotic targeting LpxC of the lipid A biosynthetic pathway in Gram-negative bacteria is a promising strategy for curing Gram-negative bacterial infections. However, experimental proof of this concept is lacking. Here, we describe our discovery and characterization of a biphenylacetylene-based inhibitor of LpxC, an essential enzyme in the biosynthesis of the lipid A component of the outer membrane of Gram-negative bacteria. The compound LPC-069 has no known adverse effects in mice and is effective in vitro against a broad panel of Gram-negative clinical isolates, including several multiresistant and extremely drug-resistant strains involved in nosocomial infections. Furthermore, LPC-069 is curative in a murine model of one of the most severe human diseases, bubonic plague, which is caused by the Gram-negative bacterium Yersinia pestis. Our results demonstrate the safety and efficacy of LpxC inhibitors as a new class of antibiotic against fatal infections caused by extremely virulent pathogens. The present findings also highlight the potential of LpxC inhibitors for clinical development as therapeutics for infections caused by multidrug-resistant bacteria.

Extended spectrum β-lactamases, carbapenemases and mobile genetic elements responsible for antibiotics resistance in Gram-negative bacteria.

Science.gov (United States)

El Salabi, Allaaeddin; Walsh, Timothey R; Chouchani, Chedly

2013-05-01

Infectious diseases due to Gram-negative bacteria are a leading cause of morbidity and mortality worldwide. Antimicrobial agents represent one major therapeutic tools implicated to treat these infections. The misuse of antimicrobial agents has resulted in the emergence of resistant strains of Gram-negatives in particular Enterobacteriaceae and non-fermenters; they have an effect not only on a human but on the public health when bacteria use the resistance mechanisms to spread in the hospital environment and to the community outside the hospitals by means of mobile genetic elements. Gram-negative bacteria have become increasingly resistant to antimicrobial agents. They have developed several mechanisms by which they can withstand to antimicrobials, these mechanisms include the production of Extended-spectrum β-lactamases (ESBLs) and carbapenemases, furthermore, Gram-negative bacteria are now capable of spreading such resistance between members of the family Enterobacteriaceae and non-fermenters using mobile genetic elements as vehicles for such resistance mechanisms rendering antibiotics useless. Therefore, addressing the issue of mechanisms of antimicrobial resistance is considered one of most urgent priorities. This review will help to illustrate different resistance mechanisms; ESBLs, carbapenemases encoded by genes carried by mobile genetic elements, which are used by Gram-negative bacteria to escape antimicrobial effect.

The Growing Threat of Multidrug-Resistant Gram-Negative Infections in Patients with Hematologic Malignancies

Science.gov (United States)

Baker, Thomas M.; Satlin, Michael J.

2016-01-01

Prolonged neutropenia and chemotherapy-induced mucositis render patients with hematologic malignancies highly vulnerable to Gram-negative bacteremia. Unfortunately, multidrug-resistant (MDR) Gram-negative bacteria are increasingly encountered globally, and current guidelines for empirical antibiotic coverage in these patients may not adequately treat these bacteria. This expansion of resistance, coupled with traditional culturing techniques requiring 2-4 days for bacterial identification and antimicrobial susceptibility results, have grave implications for these immunocompromised hosts. This review characterizes the epidemiology, risk factors, resistance mechanisms, recommended treatments, and outcomes of the MDR Gram-negative bacteria that commonly cause infections in patients with hematologic malignancies. We also examine infection prevention strategies in hematology patients, such as infection control practices, antimicrobial stewardship, and targeted decolonization. Finally, we assess strategies to improve outcomes of infected patients, including gastrointestinal screening to guide empirical antibiotic therapy, new rapid diagnostic tools for expeditious identification of MDR pathogens, and use of two new antimicrobial agents, ceftolozane/tazobactam and ceftazidime/avibactam. PMID:27339405

Diagnóstico patológico y molecular de un caso de tuberculosis laríngea primaria en un médico

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Leonardo F. Jurado

2014-03-01

Full Text Available La tuberculosis laríngea primaria es una enfermedad rara con una amplia gama de manifestaciones clínicas. Se reporta el caso de un médico otorrinolaringólogo con diabetes de tipo II y con diagnóstico de tuberculosis laríngea primaria. El diagnóstico de cáncer de cuerda vocal se había considerado en otra institución, y al ingreso el paciente sólo presentaba disfonía de seis meses de evolución. En el estudio histopatológico se encontraron granulomas, células gigantes multinucleadas, fibrosis y necrosis, y en la tinción de Ziehl-Neelsen, bacilos ácido-alcohol resistentes. El cultivo del tejido de cuerda vocal para micobacterias y la PCR-IS6110 fueron positivos. La cepa de Mycobacterium tuberculosis demostró sensibilidad a todos los medicamentos de primera línea. Se inició tratamiento según la estrategia DOTS (Directly Observed Treatment, Short-course. Se discute la presentación clínica, los diagnósticos diferenciales, el abordaje diagnóstico y los factores de riesgo asociados y se hace una breve revisión de la literatura.

Prevalence of AmpC β-lactamase among Gram-negative bacteria ...

African Journals Online (AJOL)

Purpose: Infections caused by AmpC-positive bacteria results in high patient morbidity and mortality making their detection clinically important as they cannot be detected in routine susceptibility testing. This study aim to determine the prevalence of AmpC β-lactamase among Gram negative bacteria recovered from clinical ...

Optimization of linezolid treatment regimens for Gram-positive bacterial infections based on pharmacokinetic/pharmacodynamic analysis.

Science.gov (United States)

Yang, Minjie; Zhang, Jing; Chen, Yuancheng; Liang, Xiaoyu; Guo, Yan; Yu, Jicheng; Zhu, Demei; Zhang, Yingyuan

2017-01-01

To optimize linezolid treatment regimens for Gram-positive bacterial infections based on pharmacokinetic/pharmacodynamic analysis. The minimum inhibitory concentration (MIC) distribution of 572 Gram-positive strains from patients with clinically confirmed infections was analyzed. Using the Monte Carlo simulation method, the cumulative fraction of response and probability of target attainment were determined for linezolid regimens of 600 mg q.12h and q.8h Results: Linezolid dosage of 600 mg q.12h yielded >90% cumulative fraction of response and probability of target attainment for staphylococcal infections with an MIC of ≤1 mg/l, enterococcal infections with higher MIC values required 600 mg q.8h. Linezolid 600 mg q.12h is still the clinically recommended empirical dosage for Gram-positive bacterial infections. However, as bacterial MICs increase, 600 mg q.8h may be required to achieve better efficacy.

Daptomycin: a novel lipopeptide antibiotic against Gram-positive pathogens

Directory of Open Access Journals (Sweden)

Andres Beiras-Fernandez

2010-08-01

Full Text Available Andres Beiras-Fernandez1,*, Ferdinand Vogt1,*, Ralf Sodian1, Florian Weis21Department of Cardiac Surgery, University Hospital Großhadern, Ludwig-Maximilian-University, Munich, Germany; 2Department of Anesthesiology, University Hospital Großhadern, Ludwig-Maximilian-University, Munich, Germany *Andres Beiras-Fernandez and Ferdinand Vogt contributed equally to this paperAbstract: The aim of this review is to summarize the historical background of drug resistance of Gram-positive pathogens as well as to describe in detail the novel lipopeptide antibiotic daptomycin. Pharmacological and pharmacokinetic aspects are reviewed and the current clinical use of daptomycin is presented. Daptomycin seems to be a reliable drug in the treatment of complicated skin and skin structure infections, infective right-sided endocarditis, and bacteremia caused by Gram-positive agents. Its unique mechanism of action and its low resistance profile, together with its rapid bactericidal action make it a favorable alternative to vancomycin in multi-drug resistant cocci. The role of daptomycin in the treatment of prosthetic material infections, osteomyelitis, and urogenital infections needs to be evaluated in randomized clinical trials.Keywords: daptomycin, multi-drug resistance, methicillin-resistant Staphylococcus aureus (MRSA, pneumonia, urinary tract infection, left-sided endocarditis

Risk factors for carbapenem resistant bacteraemia and mortality due to gram negative bacteraemia in a developing country

International Nuclear Information System (INIS)

Kalam, K.; Kumar, S.; Ali, S.; Baqi, S.; Qamar, F.

2014-01-01

Objective: To identify the risk factors for carbapenem resistant bacteraemia and mortality due to gram negative bacteraemia in a developing country. Methods: A prospective cohort study was conducted at the Sindh Institute of Urology and Transplantation (SIUT) from June to October 2012. Hospitalized patients > 15 years of age with gram negative bacteraemia were included and followed for a period of 2 weeks for in hospital mortality. Data was collected and analyzed for 243 subjects. Multivariate analysis was used to determine the risk factors for carbapenem resistant bacteraemia and mortality due to gram negative bacteraemia. Crude and adjusted odds ratio and 95% CI are reported. Results: A total of 729 out of 1535 (47.5%) cultures were positive for gram negative isolates. Out of 243 subjects, 117 (48%) had an MDR isolate. Having an MDR isolate on culture (AOR, 2.33; 95% CI, 1.35 -4.0), having multiple positive cultures (AOR, 1.8; 95% CI, 0.94 -3.4) and stay in ICU >48 hours (AOR, 2.0 ; 95% CI, 1.12 -3.78) were identified as significant risk factors for mortality due to gram negative organisms. Risk factors for carbapenem resistant bacteraemia were age >50 years (AOR, 1.83; 95% CI, 1.0-3.5), septic shock on presentation (AOR 2.53; 95% CI, 1.03 -6.2) , ICU stay of >72 hours (AOR 2.40; 95% CI, 1.14-5.0) and receiving immunosuppressant medications (AOR 2.23; 95% CI, 0.74 - 6.7). Conclusion: There is a high burden of MDR and carbapenem resistant gram negative bacteraemia, with a high mortality rate. (author)

Tribolium castaneum defensins are primarily active against Gram-positive bacteria

Czech Academy of Sciences Publication Activity Database

Tonk, M.; Knorr, E.; Cabezas-Cruz, A.; Valdés, James J.; Kollewe, C.; Vilcinskas, A.

2015-01-01

Roč. 132, NOV 2015 (2015), s. 208-215 ISSN 0022-2011 R&D Projects: GA MŠk(CZ) EE2.3.30.0032 Institutional support: RVO:60077344 Keywords : Antimicrobial peptides * Defensin * Innate immunity * Insects * Tribolium castaneum * Gram-positive bacteria Subject RIV: EI - Biotechnology ; Bionics Impact factor: 2.198, year: 2015

NDM 1 Gene Carrying Gram negative Bacteria Isolated from Rats ...

African Journals Online (AJOL)

In this study, we screened 56 Gram negative bacteria comprising: 3 isolates of Enterobacter ludwigii, 30 Pseudomonas aeruginosa, 22 Proteus mirabilis, and 1 Aeromonas caviae isolated from oral cavity and rectum of rats captured from commercial poultry houses in Ibadan, Oyo State, Nigeria that were resistant to at least ...

European surveillance study on antimicrobial susceptibility of Gram-positive anaerobic cocci

DEFF Research Database (Denmark)

Brazier, J; Chmelar, D; Dubreuil, L

2008-01-01

Gram-positive anaerobic cocci (GPAC) are a heterogeneous group of microorganisms frequently isolated from local and systemic infections. In this study, the antimicrobial susceptibilities of clinical strains isolated in 10 European countries were investigated. After identification of 299 GPAC...

Metallo- β-lactamases among Multidrug Resistant (MDR Gram Negative Bacteria Isolated from Clinical Specimens during 2009 in Sanandaj, Kurdistan Province

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Himen Salimizand

2012-08-01

Full Text Available Background: Today, there are numerous reports about emerging multi drug resistant gram negative bacteria all around the world, especially in ICUs. Rarely, Metallo-β-lactamase (MBL enzymes are responsible for these cases. Study of MBLs for diagnosing and preventing distribution of the origin of infection are critical issues. In addition, we would like to compare the efficacy of Iranian and foreign- made antibiotic disks. Materials and Methods: During 2009 all entered clinical specimens to the laboratory tested for detecting gram negative bacteria. Isolated bacteria were tested by Kirby-Bauer method to antibiotic susceptibility test by Iranian and foreign (MAST disks. For gram negative carbapenem resistant isolates, PCR technique used to detect VIM, GIM, and SIM variants of MBLs.Results: During one year, 17890 clinical specimens referred Besat laboratory. The most specimen was Urine (8172 followed by blood culture (5190 that in which 1110 gram negative and positives isolated. Out of which, 778 (70% of isolates were gram negatives. MDR gram negatives were 157 (20.2%. Imipenem and meropenem were the most efficient antibiotics (all susceptible and ceftriaxone was the least (19 % susceptible. E. coli was the most prevalent isolate. 79 Gram negative isolates (10.1% were resistant to Iranian-made discs but all susceptible for foreign ones. All 79 isolates were tested by PCR for MBL genes, that, all were negative. Besides, Iranian imipenem and cefepime disks have had distinguishable difference in susceptibility of isolates.Conclusion: Fortunately, none of gram negative isolates were MBL producer, which revealed no colonization of MBL producing bacteria. Iranian-made disks appear efficient except for imipenem and cefepime.

RELAÇÃO ENTRE A PERCEPÇÃO DO CLIMA ORGANIZACIONAL E O COMPORTAMENTO ORGANIZACIONAL POSITIVO: ESTUDO NO SETOR DE OBRAS DA PREFEITURA DE TAMBOARA-PR

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Joao Paulo dos Santos Sanches

2015-12-01

Full Text Available A Administração Pública tem passado por uma série de reformas, uma delas é a transição do modelo burocrático para o gerencial, essa nova maneira de gestão tem como preceitos a qualidade nos serviços, busca por eficiência e a redução de custos. Nesse contexto, a Gestão de Pessoas possui a responsabilidade de movimentar, desenvolver e valorizar os profissionais para a consecução dos objetivos organizacionais. Um dos aspectos que deve ser observado pelos gestores é a percepção que os funcionários têm sobre a organização, pois a partir dessa assimilação é que os mesmos avaliam e sentem-se satisfeitos ou não, podendo consequentemente gerar resultados indesejáveis para a organização, já que esta avaliação realizada pelos funcionários exerce influência em seu comportamento organizacional. Essa percepção, quando extraída do coletivo, também é conhecida como clima organizacional. O objetivo da pesquisa é analisar como a percepção sobre o clima organizacional dos servidores do setor de obras, da prefeitura de Tamboara-PR, influencia em seu comportamento organizacional positivo. O trabalho é classificado como de tipo descritivo, caracterizando-se como de natureza mista, a coleta de dados utilizou a população de 24 funcionários. Com os resultados demostrou-se que a percepção dos servidores tem relação com o seu comportamento organizacional positivo, visto que a existência ou a inexistência de alguns aspectos lhes exerce influência no relacionamento interpessoal e na consecução das atividades diárias.

INTERACCIÓN DE LA BACTERIA Gluconacetobacter diazotrophicus Y HORTALIZAS DE RAÍZ

OpenAIRE

Yoania Ríos Rocafull; Bernardo Dibut Álvarez; Marcia Rojas Badía; Marisel Ortega García; Noel Arozarena Daza; Janet Rodríguez Sánchez

2016-01-01

Gluconacetobacter diazotrophicus es una bacteria endófita que presenta dentro de sus características metabólicas, mecanismos directos e indirectos de estimulación del crecimiento vegetal. Se han obtenido resultados positivos por su aplicación, fundamentalmente, en gramíneas y viandas tropicales. Sin embargo, en hortalizas, las investigaciones de esta interacción plantamicroorganismo son escasas. El presente trabajo tuvo como objetivo evaluar el efecto de cuatro cepas de G. diazotrophicus aisl...

Antimicrobial Activities of Methanol, Ethanol and Supercritical CO2 Extracts of Philippine Piper betle L. on Clinical Isolates of Gram Positive and Gram Negative Bacteria with Transferable Multiple Drug Resistance.

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Demetrio L Valle

Full Text Available Piper betle L. has traditionally been used in alternative medicine in different countries for various therapeutic purposes, including as an anti-infective agent. However, studies reported in the literature are mainly on its activities on drug susceptible bacterial strains. This study determined the antimicrobial activities of its ethanol, methanol, and supercritical CO2 extracts on clinical isolates of multiple drug resistant bacteria which have been identified by the Infectious Disease Society of America as among the currently more challenging strains in clinical management. Assay methods included the standard disc diffusion method and the broth microdilution method for the determination of the minimum inhibitory concentration (MIC and the minimum bactericidal concentrations (MBC of the extracts for the test microorganisms. This study revealed the bactericidal activities of all the P. betle leaf crude extracts on methicillin-resistant Staphylococcus aureus (MRSA, vancomycin-resistant Enterococcus (VRE, extended spectrum β-lactamase-producing Enterobacteriaceae, carbapenem-resistant Enterobacteriaceae, and metallo-β-lactamase-producing Pseudomonas aeruginosa and Acinetobacter baumannii, with minimum bactericidal concentrations that ranged from 19μg/ml to 1250 μg/ml. The extracts proved to be more potent against the Gram positive MRSA and VRE than for the Gram negative test bacteria. VRE isolates were more susceptible to all the extracts than the MRSA isolates. Generally, the ethanol extracts proved to be more potent than the methanol extracts and supercritical CO2 extracts as shown by their lower MICs for both the Gram positive and Gram negative MDRs. MTT cytotoxicity assay showed that the highest concentration (100 μg/ml of P. betle ethanol extract tested was not toxic to normal human dermal fibroblasts (HDFn. Data from the study firmly established P. betle as an alternative source of anti-infectives against multiple drug resistant

Antimicrobial Activities of Methanol, Ethanol and Supercritical CO2 Extracts of Philippine Piper betle L. on Clinical Isolates of Gram Positive and Gram Negative Bacteria with Transferable Multiple Drug Resistance.

Science.gov (United States)

Valle, Demetrio L; Cabrera, Esperanza C; Puzon, Juliana Janet M; Rivera, Windell L

2016-01-01

Piper betle L. has traditionally been used in alternative medicine in different countries for various therapeutic purposes, including as an anti-infective agent. However, studies reported in the literature are mainly on its activities on drug susceptible bacterial strains. This study determined the antimicrobial activities of its ethanol, methanol, and supercritical CO2 extracts on clinical isolates of multiple drug resistant bacteria which have been identified by the Infectious Disease Society of America as among the currently more challenging strains in clinical management. Assay methods included the standard disc diffusion method and the broth microdilution method for the determination of the minimum inhibitory concentration (MIC) and the minimum bactericidal concentrations (MBC) of the extracts for the test microorganisms. This study revealed the bactericidal activities of all the P. betle leaf crude extracts on methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), extended spectrum β-lactamase-producing Enterobacteriaceae, carbapenem-resistant Enterobacteriaceae, and metallo-β-lactamase-producing Pseudomonas aeruginosa and Acinetobacter baumannii, with minimum bactericidal concentrations that ranged from 19μg/ml to 1250 μg/ml. The extracts proved to be more potent against the Gram positive MRSA and VRE than for the Gram negative test bacteria. VRE isolates were more susceptible to all the extracts than the MRSA isolates. Generally, the ethanol extracts proved to be more potent than the methanol extracts and supercritical CO2 extracts as shown by their lower MICs for both the Gram positive and Gram negative MDRs. MTT cytotoxicity assay showed that the highest concentration (100 μg/ml) of P. betle ethanol extract tested was not toxic to normal human dermal fibroblasts (HDFn). Data from the study firmly established P. betle as an alternative source of anti-infectives against multiple drug resistant bacteria.

Antimicrobial resistance pattern of Gram –negative bacilli isolated of Vali-Asr Hospital wards in Arak

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Farshid Didgar

2014-11-01

Full Text Available Background: Infectious diseases are of the most important causes of mortality all around the world particular in developing countries. Recently, the most important thing that has worried medical society is antibiotic resistance. Multi-resistant gram_negative rods are important pathogens in hospitals, causing high rate of mortality.The main goal of this study was to investigate the antimicrobial resistance patterns among common gram-negative bacilli isolated from patients of Vali-Asr Hospital. Material and Methods: This is a cross-sectional descriptive study conducted between the years 2010-2012 in Vali-Asr hospital in Arak. In this study 1120 specimen were examined. Bacterial strains were isolated by conventional methods from various clinical samples of patients including: blood, urine, wound, sputum, CSF, andetc.All isolates were examined for antimicrobial resistance using disc diffusion method. Results: In this study 737 specimen were positive cultures. A total of 332 isolates of Gram-negative bacilli were identified. The most frequent gram negative bacteria were isolated from urine, wound, blood, respiratory secretion and catheter. The most frequent pathogens were E.coli followed by k.pneumonia, entrobacter, p.oaeruginosa, Acinetobacter spp, citrobacter and proteus. High rate of resistance to third generation of cephalospoins & carbapenems observed amang isolates of Acintobacter spp.Prodution of extended spectrum beralactamases (ESBLS was found in 51.4% of all Gram negative bacteria. Conclusion: Antibiotic resistance, particularly multi-drug resistance is frequent among microorganisms of ValiAsr Hospital. Resistance in our country, like other countries have been shown to be increased, so it is highly recommended to prohibit unnecessary prescription of antibiotics.

Validation of sputum Gram stain for treatment of community-acquired pneumonia and healthcare-associated pneumonia: a prospective observational study.

Science.gov (United States)

Fukuyama, Hajime; Yamashiro, Shin; Kinjo, Kiyoshi; Tamaki, Hitoshi; Kishaba, Tomoo

2014-10-18

The usefulness of sputum Gram stain in patients with community-acquired pneumonia (CAP) is controversial. There has been no study to evaluate the diagnostic value of this method in patients with healthcare-associated pneumonia (HCAP). The purpose of this study was to evaluate the usefulness of sputum Gram stain in etiological diagnosis and pathogen-targeted antibiotic treatment of CAP and HCAP. We conducted a prospective observational study on hospitalized patients with pneumonia admitted to our hospital from August 2010 to July 2012. Before administering antibiotics on admission, Gram stain was performed and examined by trained physicians immediately after sputum samples were obtained. We analyzed the quality of sputum samples and the diagnostic performance of Gram stain. We also compared pathogen-targeted antibiotic treatment guided by sputum Gram stain with empirical treatment. Of 670 patients with pneumonia, 328 were CAP and 342 were HCAP. Sputum samples were obtained from 591 patients, of these 478 samples were good quality. The sensitivity and specificity of sputum Gram stain were 62.5% and 91.5% for Streptococcus pneumoniae, 60.9% and 95.1% for Haemophilus influenzae, 68.2% and 96.1% for Moraxella catarrhalis, 39.5% and 98.2% for Klebsiella pneumoniae, 22.2% and 99.8% for Pseudomonas aeruginosa, 9.1% and 100% for Staphylococcus aureus. The diagnostic yield decreased in patients who had received antibiotics or patients with suspected aspiration pneumonia. Pathogen-targeted treatment provided similar efficacy with a decrease in adverse events compared to empirical treatment. Sputum Gram stain is highly specific for the etiologic diagnosis and useful in guiding pathogen-targeted antibiotic treatment of CAP and HCAP.

The Role of Monitoring Gentamicin Levels in Patients with Gram-Negative Peritoneal Dialysis-Associated Peritonitis

Science.gov (United States)

Tang, Wen; Cho, Yeoungjee; Hawley, Carmel M.; Badve, Sunil V.; Johnson, David W.

2014-01-01

♦ Background: There is limited available evidence regarding the role of monitoring serum gentamicin concentrations in peritoneal dialysis (PD) patients receiving this antimicrobial agent in gram-negative PD-associated peritonitis. ♦ Methods: Using data collected in all patients receiving PD at a single center who experienced a gram-negative peritonitis episode between 1 January 2005 and 31 December 2011, we investigated the relationship between measured serum gentamicin levels on day 2 following initial empiric antibiotic therapy and subsequent clinical outcomes of confirmed gram-negative peritonitis. ♦ Results: Serum gentamicin levels were performed on day 2 in 51 (77%) of 66 first gram-negative peritonitis episodes. Average serum gentamicin levels on day 2 were 1.83 ± 0.84 mg/L with levels exceeding 2 mg/L in 22 (43%) cases. The overall cure rate was 64%. No cases of ototoxicity were observed. Day-2 gentamicin levels were not significantly different between patients who did and did not have a complication or cure. Using multivariable logistic regression analysis, failure to cure peritonitis was not associated with either day-2 gentamicin level (adjusted odds ratio (OR) 0.96, 95% confidence interval (CI) 0.25 - 3.73) or continuation of gentamicin therapy beyond day 2 (OR 0.28, 0.02 - 3.56). The only exception was polymicrobial peritonitis, where day-2 gentamicin levels were significantly higher in episodes that were cured (2.06 ± 0.41 vs 1.29 ± 0.71, p = 0.01). In 17 (26%) patients receiving extended gentamicin therapy, day-5 gentamicin levels were not significantly related to peritonitis cure. ♦ Conclusion: Day-2 gentamicin levels did not predict gentamicin-related harm or efficacy during short-course gentamicin therapy for gram-negative PD-related peritonitis, except in cases of polymicrobial peritonitis, where higher levels were associated with cure. PMID:24385334

Effects of Tillage Systems on Changes of Soil Nutrients, Yield and Land Equivalent Ratio in Roselle – Green Gram Intercropping

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A Hodiani mehr

2017-10-01

Full Text Available Introduction Intercropping is one of the components of sustainable agriculture and as part of crop rotation in the design of sustainable system. One of the benefits of intercropping is greater use of available resources. The aims of this study were to evaluate different tillage systems and cropping patterns of Roselle and Green Gram on some soil nutrients and the use efficiency of environmental resources. Usually, intercropping used at Low fertility soil with low input conditions in the tropics region. Bahrani et al. (2007 reported that no tillage systems compared with conventional tillage with crop residue, were increased soil organic carbon content in maize production. Ramroudi et al. (2011 expressed conventional tillage reduced amount of nitrogen compared to no tillage system. Material and Methods The research was conducted at Zabol city. Split plot experiment performed based on a randomized complete block design with three replications. Main plot was three levels of tillage system (zero (without plowing, reduced (disk and conventional tillage (disc plow and sub plot was planting ratio with five levels (pure culture of Roselle, pure culture of Green gram, 50% roselle+50% green gram, 25% roselle+75% green gram, 75% roselle+25% green gram were considered. Preparing the ground in mid-June 2012, according to the type of plowing was performed. For comparison of means were used by Duncan's test at 5% probability. Results and Discussion The effects of tillage systems, planting ratios and interaction of tillage systems × planting ratio on soil organic carbon and nitrogen were very significant. The highest and lowest levels of organic carbon were obtained in zero tillage (1.14% and conventional tillage systems (0.63 %, respectively. The highest and lowest nitrogen of soil after harvest, of pure culture of Green gram (0.11 % and 75 % of Roselle + 25% Green gram intercropping (0.06 % were obtained respectively, Tillage system could not affected the

Multiparametric Profiling for Identification of Chemosensitizers against Gram-Negative Bacteria

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Vincent Lôme

2018-02-01

Full Text Available Antibiotic resistance is now a worldwide therapeutic problem. Since the beginning of anti-infectious treatment bacteria have rapidly shown an incredible ability to develop and transfer resistance mechanisms. In the last decades, the design variation of pioneer bioactive molecules has strongly improved their activity and the pharmaceutical companies partly won the race against the clock. Since the 1980s, the new classes of antibiotics that emerged were mainly directed to Gram-positive bacteria. Thus, we are now facing to multidrug-resistant Gram-negative bacteria, with no therapeutic options to deal with them. These bacteria are mainly resistant because of their double membrane that conjointly impairs antibiotic accumulation and extrudes these molecules when entered. The main challenge is to allow antibiotics to cross the impermeable envelope and reach their targets. One promising solution would be to associate, in a combination therapy, a usual antibiotic with a non-antibiotic chemosensitizer. Nevertheless, for effective drug discovery, there is a prominent lack of tools required to understand the rules of permeation and accumulation into Gram-negative bacteria. By the use of a multidrug-resistant enterobacteria, we introduce a high-content screening procedure for chemosensitizers discovery by quantitative assessment of drug accumulation, alteration of barriers, and deduction of their activity profile. We assembled and analyzed a control chemicals library to perform the proof of concept. The analysis was based on real-time monitoring of the efflux alteration and measure of the influx increase in the presence of studied compounds in an automatized bio-assay. Then, synergistic activity of compounds with an antibiotic was studied and kinetic data reduction was performed which led to the calculation of a score for each barrier to be altered.

Uma visão geral da gramática funcional

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Maria Helena de Moura Neves

2001-02-01

Full Text Available

O trabalho apresenta uma visão geral do que vem sendo chamado funcionalismo em lingüística. Contrapõem-se os modelos formalista e funcionalista e examinam-se, em especial, as propostas de gramática funcional de C. S. Dik e de M. A. K. Halliday.

Performance of Gram staining on blood cultures flagged negative by an automated blood culture system.

Science.gov (United States)

Peretz, A; Isakovich, N; Pastukh, N; Koifman, A; Glyatman, T; Brodsky, D

2015-08-01

Blood is one of the most important specimens sent to a microbiology laboratory for culture. Most blood cultures are incubated for 5-7 days, except in cases where there is a suspicion of infection caused by microorganisms that proliferate slowly, or infections expressed by a small number of bacteria in the bloodstream. Therefore, at the end of incubation, misidentification of positive cultures and false-negative results are a real possibility. The aim of this work was to perform a confirmation by Gram staining of the lack of any microorganisms in blood cultures that were identified as negative by the BACTEC™ FX system at the end of incubation. All bottles defined as negative by the BACTEC FX system were Gram-stained using an automatic device and inoculated on solid growth media. In our work, 15 cultures that were defined as negative by the BACTEC FX system at the end of the incubation were found to contain microorganisms when Gram-stained. The main characteristic of most bacteria and fungi growing in the culture bottles that were defined as negative was slow growth. This finding raises a problematic issue concerning the need to perform Gram staining of all blood cultures, which could overload the routine laboratory work, especially laboratories serving large medical centers and receiving a large number of blood cultures.

Protein secretion and membrane insertion systems in gram-negative bacteria.

Science.gov (United States)

Saier, Milton H

2006-01-01

In contrast to other organisms, gram-negative bacteria have evolved numerous systems for protein export. Eight types are known that mediate export across or insertion into the cytoplasmic membrane, while eight specifically mediate export across or insertion into the outer membrane. Three of the former secretory pathway (SP) systems, type I SP (ISP, ABC), IIISP (Fla/Path) and IVSP (Conj/Vir), can export proteins across both membranes in a single energy-coupled step. A fourth generalized mechanism for exporting proteins across the two-membrane envelope in two distinct steps (which we here refer to as type II secretory pathways [IISP]) utilizes either the general secretory pathway (GSP or Sec) or the twin-arginine targeting translocase for translocation across the inner membrane, and either the main terminal branch or one of several protein-specific export systems for translocation across the outer membrane. We here survey the various well-characterized protein translocation systems found in living organisms and then focus on the systems present in gram-negative bacteria. Comparisons between these systems suggest specific biogenic, mechanistic and evolutionary similarities as well as major differences.

VIP as a potential therapeutic agent in gram negative sepsis.

Science.gov (United States)

Ibrahim, Hiba; Barrow, Paul; Foster, Neil

2012-12-01

Gram negative sepsis remains a high cause of mortality and places a great burden on public health finance in both the developed and developing world. Treatment of sepsis, using antibiotics, is often ineffective since pathology associated with the disease occurs due to dysregulation of the immune system (failure to return to steady state conditions) which continues after the bacteria, which induced the immune response, have been cleared. Immune modulation is therefore a rational approach to the treatment of sepsis but to date no drug has been developed which is highly effective, cheap and completely safe to use. One potential therapeutic agent is VIP, which is a natural peptide and is highly homologous in all vertebrates. In this review we will discuss the effect of VIP on components of the immune system, relevant to gram negative sepsis, and present data from animal models. Furthermore we will hypothesise on how these studies could be improved in future and speculate on the possible different ways in which VIP could be used in clinical medicine.

[Development and Evaluation of a New Selective Culture Medium, KBM Anaero RS-GNR, for Detection of Anaerobic Gram Negative Rods].

Science.gov (United States)

Narita, Taeko; Kato, Kyohei; Hanaiwa, Hiroki; Harada, Tetsuhiro; Funashima, Yumiko; Akiwa, Makoto; Sekiguchi, Jun-Ichiro; Nagasawa, Zenzo; Umemura, Tsukuru

2017-03-22

The laboratory culture methods for isolating drug-resistant pathogens has been the gold standard in medical microbiology, and play pivotal roles in the overall management of infectious diseases. Recently, several reports have emphasized the development of antibiotics-resistance among anaerobic gram-negative rods, especially Genus Bacteroides and Prevotella . Therefore, a selective culture method to detect these pathogens is needed. We developed here the new selective culture medium, termed "KBM Anaero RS-GNR," for detecting anaerobic Gram-negative rods. Growth capability and selectivity of the agar medium were assessed by using the pure culture suspensions of more than 100 bacterial strains as well as the 13 samples experimentally contaminated with these bacterial strains. This new medium, "KBM Anaero RS-GNR," successfully showed the selective isolation of anaerobic Gram-negative rods. Compared with commercially available medium, "PV Brucella HK Agar, " which is also designed to detect anaerobic Gram-negative rods, there was no significant difference of the overall detection efficiency between two media. However, "KBM Anaero RS-GNR" showed superior to selectivity for anaerobic Gram-negative rods, especially from the samples contaminated with Candida species. Thus, the culture method using KBM Anaero RS-GNR is relevant for isolation of anaerobic Gram-negative rods especially from clinical specimens.

DMPD: Gram-negative endotoxin: an extraordinary lipid with profound effects oneukaryotic signal transduction. [Dynamic Macrophage Pathway CSML Database

Lifescience Database Archive (English)

Full Text Available 1916089 Gram-negative endotoxin: an extraordinary lipid with profound effects oneuk...ep;5(12):2652-60. (.png) (.svg) (.html) (.csml) Show Gram-negative endotoxin: an extraordinary lipid with profound effects...tive endotoxin: an extraordinary lipid with profound effects oneukaryotic signal transduction. Authors Raetz

Biofilm detection in chronic rhinosinusitis by combined application of hematoxylin-eosin and gram staining.

Science.gov (United States)

Tóth, László; Csomor, Péter; Sziklai, István; Karosi, Tamás

2011-10-01

The pathomechanism of chronic rhinosinusitis with nasal polyposis (CRS/NP) seems to be unclear. Bacterial-, fungal- and combined biofilms might play a potential role in the pathogenesis of various inflammatory diseases and recently in CRS/NP. A prospective, blinded observational study was performed to confirm that the combination of conventional hematoxylin-eosin (HE) and Gram staining protocols could be used to detect bacterial and fungal biofilms in patients with CRS/NP. A total of 50 patients with CRS/NP undergoing endoscopic sinus surgery (ESS) were analyzed. The negative control group consisted of 12 patients undergoing septoplasty for nasal obstruction without CRS/NP. The nasal polyps and inferior turbinate mucosa specimens applied as negative controls were processed to HE and Gram staining. Biofilm was detected in 44 of 50 patients with CRS/NP and in none of 12 negative controls. In our series, HE method showed an obvious correlation with the results of Gram staining and was allocated to be a good predictor of biofilm existence. It was found that the microscopic structure and thickness of biofilms were strongly associated with the integrity of nasal mucosa and with the characteristics of subepithelial cellular infiltration. This study confirmed the presence of bacterial and fungal biofilms on the surface of NPs obtained from patients with CRS. Since biofilms may affect the severity and recurrence rate of CRS treated by ESS they should be detected histologically. In conclusion, HE staining combined with Gram protocol is a robust and reliable method for the detection of bacterial and fungal biofilms in CRS/NP.

Antimicrobial effects of zero-valent iron nanoparticles on gram-positive Bacillus strains and gram-negative Escherichia coli strains

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Yi-Huang Hsueh

2017-11-01

Full Text Available Abstract Background Zero-valent iron nanoparticles (ZVI NPs have been used extensively for the remediation of contaminated soil and groundwater. Owing to their large active surface area, they serve as strong and effective reductants. However, the ecotoxicity and bioavailability of ZVI NPs in diverse ecological media have not been evaluated in detail and most studies have focused on non-nano ZVI or Fe0. In addition, the antimicrobial properties of ZVI NPs have rarely been investigated, and the underlying mechanism of their toxicity remains unknown. Results In the present study, we demonstrate that ZVI NPs exhibited significant toxicity at 1000 ppm against two distinct gram-positive bacterial strains (Bacillus subtilis 3610 and Bacillus thuringiensis 407 but not against two gram-negative strains (Escherichia coli K12 and ATCC11634. Specifically, ZVI NPs caused at least a 4-log and 1-log reductions in cell numbers, respectively, in the two Bacillus strains, whereas no change was detected in the two E. coli strains. X-ray photoelectron spectroscopy, X-ray absorption near-edge, and extended X-ray absorption fine structure spectra confirmed that Bacillus cells exposed to ZVI NPs contained mostly Fe2O3 with some detectable FeS. This finding indicated that Fe0 nanoparticles penetrated the bacterial cells, where they were subsequently oxidized to Fe2O3 and FeS. RedoxSensor analysis and propidium iodide (PI staining showed decreased reductase activity and increased PI in both Bacillus strains treated with a high (1000 ppm concentration of ZVI NPs. Conclusion Taken together, these data show that the toxicity of ZVI NPs was derived from their oxidative properties, which may increase the levels of reactive oxygen species and lead to cell death.

Electron beam irradiation: a technology for quarantine disinfestation of green gram seeds against Callsobruchus maculatus

International Nuclear Information System (INIS)

Bhalla, Shashi; Srinivasan, K.; Singh, Subadas; Thakur, Manju; Sharma, S.K.; Pramod, R.; Dwivedi, J.; Bapna, S.C.

2010-01-01

Green gram (Vigna radiata (L.) Wilkzec) an important legume crop in India is grown in 33.4 lakh hectares. India accounts for ∼ 60% of the world's green gram area but contributes only 47% of its production. Major constraint in storage is the pulse beetle Callosobruchus maculatus Fab. (Coleoptera: Bruchidae), which may cause damage upto 100%. It is widespread throughout tropics and sub-tropics with wide host range and also has different strains. Fumigation with methyl bromide (MB) has been the most widely applied management practice for its control. However, the ozone depleting effect of MB has led to restrictions in its use. Therefore, there is a need for an alternative strategy for controlling the pests. Irradiation, an approved technology by International Plant Protection Convention, seems to be a viable non-chemical, residue-free strategy. Therefore, present studies were conducted to see the efficacy of electron beam (EB) irradiation as quarantine disinfestation treatment against green gram seeds infested with different stages of the target pest, C. maculatus

Tuberculose e parasitismo intestinal em população indígena na Amazônia brasileira Tuberculosis y parasitismo intestinal en población indígena en el Amazonas Brasilero Tuberculosis and intestinal parasitism among indigenous people in the Brazilian Amazon region

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Márcio Neves Bóia

2009-02-01

Full Text Available O objetivo do estudo foi estimar as freqüências de tuberculose e parasitoses intestinais na em comunidades indígenas da localidade de Iauareté (AM, em 2001. Estudo transversal (n=333 visando à obtenção de dados demográficos e amostras biológicas para exames de escarro e fezes. Dentre os 43 sintomáticos respiratórios, seis foram positivos na pesquisa de bacilos álcool-ácido resistentes no escarro. As parasitoses intestinais apresentaram freqüência significativamente maior entre a população Hüpda do que entre os índios que habitam os demais bairros (37,5% vs. 19,3% para Ascaris lumbricoides, 32,4% vs. 16,3% para Trichuris trichiura, 75% vs. 19,3% para ancilostomídeos, 75% vs. 35,4% para Entamoeba histolyticaD dispar e 33,3% vs. 10,7% para Giardia lamblia. Conclui-se que a tuberculose e o parasitismo intestinal são freqüentes nessas comunidades, exigindo medidas de controle e melhorias na assistência à saúde.El objetivo del estudio fue estimar las frecuencias de tuberculosis y parasitosis intestinales en las comunidades indígenas de la localidad de Iauareté (Norte de Brasil, en 2001. Estudio transversal (n=333 intentando obtener datos demográficos y muestras biológicas para examenes de esputo y heces. Entre los 43 sintomáticos respiratorios, seis fueron positivos en la pesquisa de bacilos alcohol-ácido resistentes en el esputo. Las parasitosis intestinales presentaron frecuencia significativamente mayor entre la población Hüpda que entre los indios que habitan las demás localidades (37,5% vs. 19,3% para Ascaris lumbricoides, 32,4% vs. 16,3% para Trichuris trichiura, 75% vs. 19,3% para ancilostomídeos, 75% vs. 35,4% para Entamoeba histolytica/dispar y 33,3% vs. 10,7% para Giardia lamblia. Se concluyó que la tuberculosis y el parasitismo intestinal son frecuentes en esas comunidades, exigiendo medidas de control y mejorías en la asistencia a la salud.The objective of the survey was to estimate the frequencies of

Loss of outer membrane integrity in Gram-negative bacteria by silver ...

Indian Academy of Sciences (India)

plausible mechanism of bacterial cell disintegration ... New generation antimicrobial and smart drugs are the needs of the present era in fighting microbial ... charides (LPSs) in nature where the lipid portion acts ... sive release of LPS molecules and membrane proteins [10]. ... efficacy of antimicrobial action on Gram bacteria.

Seis gramáticos celebérrimos, y sus gramáticas: Panini, Dionicio de Tracia, Antonio de Nebrija, Andrés Bello, Rufino José Cuervo Urisarri y Miguel Antonio Caro Tobar

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JOSELYN CORREDOR TAPIAS

2009-01-01

Full Text Available El artículo presenta, en primer lugar, unas consideraciones liminares sobre la gramática. Expone algunas definiciones y perspectivas acerca de ésta; contiene algunos datos generales, más gramaticales que biográficos, acerca de seis figuras descollantes en el ámbito de la gramática: Panini, De Tracia, De Nebrija, Bello, Cuervo, y Caro; finalmente, se concluye con la importancia de dominar un acervo gramatical-lingüístico, si se trata de estudiar, en el contexto de su enseñanza, la lengua materna o una extranjera.

VDRL falso-positivo em recém-nascido filho de mãe portadora de síndrome antifosfolípide – relato de caso

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Marina Helena Mariano

2015-10-01

Full Text Available A incidência de sífilis congênita foi de 1,9 para cada 1000 nascimentos em 2005. Para alterar esse quadro, a prevenção e o diagnóstico no pré-natal e no parto foram reforçados pelo rastreamento com o VDRL. Apesar da alta sensibilidade desse teste, os resultados falso-positivos são possíveis, principalmente em doenças autoimunes e infecções, podendo ocorrer também a transferência passiva para o recém-nascido (RN. RN de J.L.S.A., 16 dias de vida, masculino, nascido em Sorocaba. Mãe com infecção urinária vigente no parto, sorologias negativas no 1º e 3º trimestre e histórico obstétrico de natimorto e aborto anteriores. Parto cesárea de urgência por pré-eclâmpsia e centralização fetal realizado com 30 semanas. RN pré-termo, pequeno para idade gestacional, muito baixo peso, desconforto neonatal precoce, infecção neonatal presumida. Evoluiu com apneia, sepse, plaquetopenia e crises convulsivas, permanecendo na UTI por 16 dias. Realizadas hemocultura e urocultura – negativas - e VRDL no RN e na mãe cujos resultados foram 1/2. Desse modo, iniciou-se o tratamento para o RN por sífilis congênita presumida. Devido baixos títulos e antecedentes maternos, foi pesquisada e confirmada Síndrome Antifosfolípide para mãe, concluindo-se tratar de um falso positivo para ambos. O relato tem como objetivo enfatizar a importância no cuidado do rastreamento eficaz da sífilis congênita, por se tratar de transmissibilidade vertical de uma doença sexualmente transmissível, o que pode abalar a integridade de uma família.

Horse gram- an underutilized nutraceutical pulse crop: a review

OpenAIRE

Prasad, Saroj Kumar; Singh, Manoj Kumar

2014-01-01

Horse gram is an underutilized pulse crop grown in wide range of adverse climatic conditions. It occupies an important place in human nutrition and has rich source of protein, minerals, and vitamins. Besides nutritional importance, it has been linked to reduced risk of various diseases due to presence of non-nutritive bioactive substances. These bioactive substances such as phytic acid, phenolic acid, fiber, enzymatic/proteinase inhibitors have significant metabolic and/or physiological effec...

The Effect of Charge at the Surface of Silver Nanoparticles on Antimicrobial Activity against Gram-Positive and Gram-Negative Bacteria: A Preliminary Study

International Nuclear Information System (INIS)

Abbaszadegan, A.; Ghahramani, Y.; Nabavizadeh, M.; Gholami, A.; Hemmateenejad, I.; Dorostkar, S.; Sharghi, H.

2014-01-01

The bactericidal efficiency of various positively and negatively charged silver nanoparticles has been extensively evaluated in literature, but there is no report on efficacy of neutrally charged silver nanoparticles. The goal of this study is to evaluate the role of electrical charge at the surface of silver nanoparticles on antibacterial activity against a panel of microorganisms. Three different silver nanoparticles were synthesized by different methods, providing three different electrical surface charges (positive, neutral, and negative). The antibacterial activity of these nanoparticles was tested against gram-positive (i.e., Staphylococcus aureus, Streptococcus mutans, and Streptococcus pyogenes) and gram-negative (i.e., Escherichia coli and Proteus vulgaris) bacteria. Well diffusion and micro-dilution tests were used to evaluate the bactericidal activity of the nanoparticles. According to the obtained results, the positively-charged silver nanoparticles showed the highest bactericidal activity against all microorganisms tested. The negatively charged silver nanoparticles had the least and the neutral nanoparticles had intermediate antibacterial activity. The most resistant bacteria were Proteus vulgaris. We found that the surface charge of the silver nanoparticles was a significant factor affecting bactericidal activity on these surfaces. Although the positively charged nanoparticles showed the highest level of effectiveness against the organisms tested, the neutrally charged particles were also potent against most bacterial species.

Comparison of the Cathra Repliscan II, the AutoMicrobic system Gram-Negative General Susceptibility-Plus Card, and the Micro-Media System Fox Panel for dilution susceptibility testing of gram-negative bacilli.

Science.gov (United States)

Reiber, N E; Kelly, M T; Latimer, J M; Tison, D L; Hysmith, R M

1985-06-01

A comparative evaluation was done to test the accuracy of the Cathra Repliscan II agar dilution system (Diagnostic Equipment, Inc., St. Paul, Minn.), the AutoMicrobic system with Gram-Negative General Susceptibility-Plus Card (Vitek Systems, Inc., Hazelwood, Mo.), and the Micro-Media Fox Panel micro broth dilution system (Micro-Media Systems, Inc., San Jose, Calif.) in determining MICs of 12 antibiotics for 200 gram-negative bacilli. Of the 200 strains tested, 12 isolates did not grow in one of the three systems. The 188 remaining organisms included 158 members of the family Enterobacteriaceae, 20 Pseudomonas spp., 5 Acinetobacter sp., 3 Aeromonas spp., and 2 Vibrio spp. A total of 2,256 organism-antibiotic combinations were analyzed for each system. An MIC was considered correct if two of the three systems were in agreement. When disagreements occurred, correct MICs were determined by the standard agar dilution method. With this criterion, overall agreements of the Cathra Repliscan II system, AutoMicrobic system, and Micro-Media Fox Panel system were 94.7, 94.9, and 95.5%, respectively. Tetracycline (20%), nitrofurantoin (20%), and ampicillin (16%) accounted for 56% of the discrepancies observed. These results indicate that all three systems perform with a high degree of accuracy for susceptibility testing of gram-negative bacilli.

Burdock (Arctium lappa Leaf Extracts Increase the In Vitro Antimicrobial Efficacy of Common Antibiotics on Gram-positive and Gram-negative Bacteria

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Pirvu Lucia

2017-04-01

Full Text Available This work aimed to study the potential effects of four Arctii folium extracts, 5 mg gallic [GAE] acid equivalents per 1 mL sample, on six antibiotics (Ampicillin/AM, Tetracycline/TE, Ciprofloxacin/CIP, Sulfamethoxazole-Trimethoprim/SXT, Chloramphenicol/C and Gentamicin/CN tested on four Gram-positive (Staphylococcus aureus ATCC 6538, Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212, and Staphylococcus epidermidis ATCC 12228 and five Gram-negative (Proteus mirabilis ATCC 29245, Escherichia coli ATCC 35218, E. coli ATCC 11229, E. coli ATCC 8739, and Bacillus cereus ATCC 11778 bacteria. Arctii folium extracts were the whole ethanol extract/W and subsequent ethyl acetate/EA, aqueous/AQ, and chloroform/CHL fractions. Chemical qualitative analysis (HPTLC method emphasized five main polyphenol compounds in Arctii folium polar extracts: chlorogenic acid (Rf≈0.52/0.55 and its isomer, 1,5-di-O-caffeoylquinic acid (Rf≈0.90/0.92, plus cynarin (Rf≈0.77, hyperoside (Rf≈0.68/0.64 and isoquercitrin (Rf≈0.69/0.71. Microbiological screening indicated Arctii folium polar extracts (AQ and W efficacy on S. epidermidis ATCC 12228; the MIC values were in the range of common antibiotics, being 32 and 128 μg GAE per mL sample respectively. The unpredictable effects (stimulatory or inhibitory of Arctii folium extracts in combination with typical antibiotics as well as a potential use of the whole ethanol extract/W for restoring the antimicrobial potency of susceptible antibiotics have also been evidenced.

Nodulation studies with induced mutants of black gram (Vigna mungo L.)

International Nuclear Information System (INIS)

Mahna, S.K.; Garg, Rekha; Parvateesam, M.

1990-01-01

Mutation breeding has been widely used to generate genetic variability in plants, but reports of mutations affecting the root system are less common. In the present work, black gram (Vigna mungo L. var T9), has been used for studies on the effect of induced mutations on nodulation patterns

The complete genome sequence of the Gram-positive bacterium Bacillus subtilis

NARCIS (Netherlands)

Kunst, F; Ogasawara, N; Moszer, [No Value; Albertini, AM; Alloni, G; Azevedo, [No Value; Bertero, MG; Bessieres, P; Bolotin, A; Borchert, S; Borriss, R; Boursier, L; Brans, A; Brignell, SC; Bron, S; Brouillet, S; Bruschi, CV; Caldwell, B; Capuano, [No Value; Carter, NM; Choi, SK; Codani, JJ; Connerton, IF; Cummings, NJ; Daniel, RA; Denizot, F; Devine, KM; Dusterhoft, A; Ehrlich, SD; Emmerson, PT; Entian, KD; Errington, J; Fabret, C; Ferrari, E; Foulger, D; Fujita, M; Fujita, Y; Fuma, S; Galizzi, A; Galleron, N; Ghim, SY; Glaser, P; Goffeau, A; Golightly, EJ; Grandi, G; Guiseppi, G; Guy, BJ; Haga, K; Haiech, J; Harwood, CR; Henaut, A; Hilbert, H; Holsappel, S; Hosono, S; Hullo, MF; Itaya, M; Jones, L; Joris, B; Karamata, D; Kasahara, Y; KlaerrBlanchard, M; Klein, C; Kobayashi, Y; Koetter, P; Koningstein, G; Krogh, S; Kumano, M; Kurita, K; Lapidus, A; Lardinois, S; Lauber, J; Lazarevic, [No Value; Lee, SM; Levine, A; Liu, H; Masuda, S; Mauel, C; Medigue, C; Medina, N; Mellado, RP; Mizuno, M; Moestl, D; Nakai, S; Noback, M; Noone, D; OReilly, M; Ogawa, K; Ogiwara, A; Oudega, B; Park, SH; Parro, [No Value; Pohl, TM; Portetelle, D; Porwollik, S; Prescott, AM; Presecan, E; Pujic, P; Purnelle, B; Rapoport, G; Rey, M; Reynolds, S; Rieger, M; Rivolta, C; Rocha, E; Roche, B; Rose, M; Sadaie, Y; Sato, T; Scanlan, E; Schleich, S; Schroeter, R; Scoffone, F; Sekiguchi, J; Sekowska, A; Seror, SJ; Serror, P; Shin, BS; Soldo, B; Sorokin, A; Tacconi, E; Takagi, T; Takahashi, H; Takemaru, K; Takeuchi, M; Tamakoshi, A; Tanaka, T; Terpstra, P; Tognoni, A; Tosato, [No Value; Uchiyama, S; Vandenbol, M; Vannier, F; Vassarotti, A; Viari, A; Wambutt, R; Wedler, E; Wedler, H; Weitzenegger, T; Winters, P; Wipat, A; Yamamoto, H; Yamane, K; Yasumoto, K; Yata, K; Yoshida, K; Yoshikawa, HF; Zumstein, E; Yoshikawa, H; Danchin, A

1997-01-01

Bacillus subtilis is the best-characterized member of the Gram-positive bacteria. Its genome of 4,214,810 base pairs comprises 4,100 protein-coding genes. Of these protein-coding genes, 53% are represented once, while a quarter of the genome corresponds to several gene families that have been

Prevalence and risk factors for CTX-M gram-negative bacteria in hospitalized patients at a tertiary care hospital in Kilimanjaro, Tanzania

DEFF Research Database (Denmark)

Sonda, Tolbert; Kumburu, Happiness; van Zwetselaar, Marco

2018-01-01

Emergence and spread of extended spectrum beta-lactamase (ESBL)-producing gram-negative bacteria, mainly due to CTX-M, is a major global public health problem. Patients infected with ESBL-producing gram-negative bacteria have an increased risk of treatment failure and death. We investigated...... 2015 were fully genome sequenced. The prevalence of ESBL-producing gram-negative bacteria was determined based on the presence of blaCTX-M. The odds ratio (OR) and risk factors for ESBL-producing gram-negative bacteria due to CTX-M were assessed using logistic regression models. The overall CTX......-M prevalence (95% CI) was 13.6% (10.1–18.1). Adjusted for other factors, the OR of CTX-M gram-negative bacteria for patients previously hospitalized was 0.26 (0.08–0.88), p = 0.031; the OR for patients currently on antibiotics was 4.02 (1.29–12.58), p = 0.017; the OR for patients currently on ceftriaxone was 0...

Metabolic versatility of Gram-positive microbial isolates from contaminated river sediments

International Nuclear Information System (INIS)

Narancic, Tanja; Djokic, Lidija; Kenny, Shane T.; O’Connor, Kevin E.; Radulovic, Vanja; Nikodinovic-Runic, Jasmina; Vasiljevic, Branka

2012-01-01

Highlights: ► Thirty-four isolated Gram-positive bacteria could degrade wide range of aromatic pollutants. ► Nine isolates could grow in the presence of extremely high levels of heavy metals. ► Twelve isolates accumulated polyphosphate, 3 polyhydroxybutyrate, 4 exopolysaccharides. ► The incidence of multiple antibiotic resistance markers among isolates was low. - Abstract: Gram-positive bacteria from river sediments affected by the proximity of a petrochemical industrial site were isolated and characterized with respect to their ability to degrade a wide range of aromatic compounds. In this study we identified metabolically diverse Gram-positive bacteria capable of growth on wide range aromatic compounds in the presence of heavy metals and with the ability to accumulate biopolymers. Thirty-four isolates that were able to use 9 or more common aromatic pollutants, such as benzene, biphenyl, naphthalene etc. as a sole source of carbon and energy included members of Bacillus, Arthrobacter, Rhodococcus, Gordonia, Streptomyces, and Staphylococcus genus. Rhodococcus sp. TN105, Gordonia sp. TN103 and Arthrobacter sp. TN221 were identified as novel strains. Nine isolates were able to grow in the presence of one or more metals (mercury, cadmium, nickel) at high concentration (100 mM). Seven isolates could degrade 15 different aromatic compounds and could grow in the presence of one or more heavy metals. Two of these isolates were resistant to multiple antibiotics including erythromycin and nalidixic acid. One third of isolates could accumulate at least one biopolymer. Twelve isolates (mainly Bacillus sp. and Arthrobacter sp.) accumulated polyphosphate, 3 Bacillus sp. accumulated polyhydroxybutyrate, while 4 isolates could accumulate exopolysaccharides.

Operation of the TSTA (Tritium Systems Test Assembly) with 100 gram tritium

International Nuclear Information System (INIS)

Sherman, R.H.; Bartlit, J.R.

1988-01-01

In March of 1988 full operation of the 4-column isotope separation system (ISS) was realized in runs that approximated the design load of tritium. Previous operations had been fraught with operating difficulties principally due to external systems. This report will examine the recent highly successful 6-day period of operation. During this time the system was cooled from room temperature, loaded with hydrogen isotopes including 109 grams of tritium, integrated with the transfer pumping, impurity injection, and impurity removal systems, as well as the remote computer control system. At the end of the operation 12 grams of tritium having a measured purity of 99.987% (remainder deuterium) were offloaded from the system. Observed profiles in the columns in general agree with computer models. A Height Equivalent to a Theoretical Plate (HETP) of 5.0 cm is confirmed. 3 refs., 5 figs

Trojan Horse Antibiotics-A Novel Way to Circumvent Gram-Negative Bacterial Resistance?

Science.gov (United States)

Tillotson, Glenn S

2016-01-01

Antibiotic resistance has been emerged as a major global health problem. In particular, gram-negative species pose a significant clinical challenge as bacteria develop or acquire more resistance mechanisms. Often, these bacteria possess multiple resistance mechanisms, thus nullifying most of the major classes of drugs. Novel approaches to this issue are urgently required. However, the challenges of developing new agents are immense. Introducing novel agents is fraught with hurdles, thus adapting known antibiotic classes by altering their chemical structure could be a way forward. A chemical addition to existing antibiotics known as a siderophore could be a solution to the gram-negative resistance issue. Siderophore molecules rely on the bacterial innate need for iron ions and thus can utilize a Trojan Horse approach to gain access to the bacterial cell. The current approaches to using this potential method are reviewed.

Efecto de cihalofop-butilo en el control de malezas gramíneas anuales en arroz de temporal

Directory of Open Access Journals (Sweden)

Valent\\u00EDn A. Esqueda

2004-01-01

Full Text Available Efecto de cihalofop-butilo para el control de malezas gramíneas anuales en arroz de temporal. Con objeto de evaluar la efectividad del herbicida cihalofop-butilo en el control de malezas gramíneas anuales en el arroz de temporal cv Milagro Filipino, durante 2002, se condujeron dos experimentos en el municipio de Tres Valles, Ver., México. En ambos experimentos se utilizó el diseño experimental de bloques al azar con siete tratamientos y cuatro repeticiones: cihalofop-butilo a 180, 225, 270, 315 y 360 g/ha, propanil a 4.320 g/ha y un testigo sin aplicar. Los tratamientos se aplicaron cuando el arroz tenía una altura de aproximadamente 25 cm. Las malezas gram íneas presentes fueron el zacate de agua y el zacate frente de toro [Digitaria ciliaris (Retz. Koeler]. El control de malezas gramíneas anuales y la toxicidad del herbicida al arroz se evaluaron a los 15, 30 y 45 días después de la aplicación. Los mejores controles de los zacates de agua y frente de toro se obtuvieron cuando cihalofop-butilo se aplicó a 315 y 360 g/ha. Las diferentes dosis de este herbicida, no ocasionaron toxicidad al arroz. El efecto en el control de las malezas gramíneas por el propanil fue similar al de cihalofop-butilo en dosis de 360 g/ha durante los primeros 15 días después de su aplicación.

GramHealth: a bottom-up approach to provide preventive healthcare services for unreached community.

Science.gov (United States)

Ahmed, Ashir; Kabir, Lutfe; Kai, Eiko; Inoue, Sozo

2013-01-01

Insufficient healthcare facilities and unavailability of medical experts in rural areas are the two major reasons that kept the people unreached to healthcare services. Recent penetration of mobile phone and the demand to basic healthcare services, remote health consultancy over mobile phone became popular in developing countries. In this paper, we introduce two such representative initiatives from Bangladesh and discuss the technical challenges they face to serve a remote patient. To solve these issues, we have prototyped a box with necessary diagnostic tools, we call it a "portable clinic" and a software tool, "GramHealth" for managing the patient information. We carried out experiments in three villages in Bangladesh to observe the usability of the portable clinic and verify the functionality of "GramHealth". We display the qualitative analysis of the results obtained from the experiment. GramHealth DB has a unique combination of structured, semi-structured and un-structured data. We are currently looking at these data to see whether these can be treated as BigData and if yes, how to analyze the data and what to expect from these data to make a better clinical decision support.

Gram-Negative Infections in Adult Intensive Care Units of Latin America and the Caribbean

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Carlos M. Luna

2014-01-01

Full Text Available This review summarizes recent epidemiology of Gram-negative infections in selected countries from Latin American and Caribbean adult intensive care units (ICUs. A systematic search of the biomedical literature (PubMed was performed to identify articles published over the last decade. Where appropriate, data also were collected from the reference list of published articles, health departments of specific countries, and registries. Independent cohort data from all countries (Argentina, Brazil, Chile, Colombia, Cuba, Mexico, Trinidad and Tobago, and Venezuela signified a high rate of ICU infections (prevalence: Argentina, 24%; Brazil, 57%. Gram-negative pathogens, predominantly Acinetobacter baumannii, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Escherichia coli, accounted for >50% of ICU infections, which were often complicated by the presence of multidrug-resistant strains and clonal outbreaks. Empirical use of antimicrobial agents was identified as a strong risk factor for resistance development and excessive mortality. Infection control strategies utilizing hygiene measures and antimicrobial stewardship programs reduced the rate of device-associated infections. To mitigate the poor health outcomes associated with infections by multidrug-resistant Gram-negative bacteria, urgent focus must be placed on infection control strategies and local surveillance programs.

Detection of Cross Site Scripting Attack in Wireless Networks Using n-Gram and SVM

Directory of Open Access Journals (Sweden)

Jun-Ho Choi

2012-01-01

Full Text Available Large parts of attacks targeting the web are aiming at the weak point of web application. Even though SQL injection, which is the form of XSS (Cross Site Scripting attacks, is not a threat to the system to operate the web site, it is very critical to the places that deal with the important information because sensitive information can be obtained and falsified. In this paper, the method to detect themalicious SQL injection script code which is the typical XSS attack using n-Gram indexing and SVM (Support Vector Machine is proposed. In order to test the proposed method, the test was conducted after classifying each data set as normal code and malicious code, and the malicious script code was detected by applying index term generated by n-Gram and data set generated by code dictionary to SVM classifier. As a result, when the malicious script code detection was conducted using n-Gram index term and SVM, the superior performance could be identified in detecting malicious script and the more improved results than existing methods could be seen in the malicious script code detection recall.

Synergistic antibacterial effect of silver and ebselen against multidrug-resistant Gram-negative bacterial infections.

Science.gov (United States)

Zou, Lili; Lu, Jun; Wang, Jun; Ren, Xiaoyuan; Zhang, Lanlan; Gao, Yu; Rottenberg, Martin E; Holmgren, Arne

2017-08-01

Multidrug-resistant (MDR) Gram-negative bacteria account for a majority of fatal infections, and development of new antibiotic principles and drugs is therefore of outstanding importance. Here, we report that five most clinically difficult-to-treat MDR Gram-negative bacteria are highly sensitive to a synergistic combination of silver and ebselen. In contrast, silver has no synergistic toxicity with ebselen on mammalian cells. The silver and ebselen combination causes a rapid depletion of glutathione and inhibition of the thioredoxin system in bacteria. Silver ions were identified as strong inhibitors of Escherichia coli thioredoxin and thioredoxin reductase, which are required for ribonucleotide reductase and DNA synthesis and defense against oxidative stress. The bactericidal efficacy of silver and ebselen was further verified in the treatment of mild and acute MDR E. coli peritonitis in mice. These results demonstrate that thiol-dependent redox systems in bacteria can be targeted in the design of new antibacterial drugs. The silver and ebselen combination offers a proof of concept in targeting essential bacterial systems and might be developed for novel efficient treatments against MDR Gram-negative bacterial infections. © 2017 The Authors. Published under the terms of the CC BY 4.0 license.

In vitro activities of dalbavancin and nine comparator agents against anaerobic gram-positive species and corynebacteria.

Science.gov (United States)

Goldstein, Ellie J C; Citron, Diane M; Merriam, C Vreni; Warren, Yumi; Tyrrell, Kerin; Fernandez, Helen T

2003-06-01

Dalbavancin is a novel semisynthetic glycopeptide with enhanced activity against gram-positive species. Its comparative in vitro activities and those of nine comparator agents, including daptomycin, vancomycin, linezolid, and quinupristin-dalfopristin, against 290 recent gram-positive clinical isolates strains, as determined by the NCCLS agar dilution method, were studied. The MICs of dalbavancin at which 90% of various isolates tested were inhibited were as follows: Actinomyces spp., 0.5 microg/ml; Clostridium clostridioforme, 8 microg/ml; C. difficile, 0.25 microg/ml; C. innocuum, 0.25 microg/ml; C. perfringens, 0.125 microg/ml; C. ramosum, 1 microg/ml; Eubacterium spp., 1 microg/ml; Lactobacillus spp., >32 microg/ml, Propionibacterium spp., 0.5 microg/ml; and Peptostreptococcus spp., 0.25 microg/ml. Dalbavancin was 1 to 3 dilutions more active than vancomycin against most strains. Dalbavancin exhibited excellent activity against gram-positive strains tested and warrants clinical evaluation.

Gram-positive bacteria as an antigen topically applied into gingival sulcus of immunized rat accelerates periodontal destruction.

Science.gov (United States)

Nagano, F; Kaneko, T; Yoshinaga, Y; Ukai, T; Kuramoto, A; Nakatsu, S; Oshino, K; Ichimura, I; Hara, Y

2013-08-01

Periodontitis is generally accepted to relate to gram-negative bacteria, and the host defense system influences its onset and progression. However, little is known about the relation between gram-positive bacteria and periodontitis. In this study, we topically applied gram-positive and gram-negative bacterial suspensions to the gingival sulcus in rats after immunization, and then histopathologically examined their influence on periodontal destruction. Rats previously immunized with heat-treated and sonicated Staphylococcus aureus or Aggregatibacter actinomycetemcomitans were used as immunized groups. The non-immunized group received only sterile phosphate-buffered saline. In each animal, S. aureus or A. actinomycetemcomitans suspension was applied topically to the palatal gingival sulcus of first molars every 24 h for 10 d. Blood samples were collected and the serum level of anti-S. aureus or anti-A. actinomycetemcomitans immunoglobulin G (IgG) antibodies was determined by enzyme-linked immunosorbent assay. The first molar regions were resected and observed histopathologically. Osteoclasts were stained with tartrate-resistant acid phosphatase (TRAP). The formation of immune complexes was confirmed by immunohistological staining of C1qB. Serum levels of anti-S. aureus and anti-A. actinomycetemcomitans IgG antibodies in the immunized groups were significantly higher than those in the non-immunized groups were. The loss of attachment, increase in apical migration of the junctional epithelium, and decreases in alveolar bone level and number of TRAP-positive multinuclear cells in each immunized group were significantly greater than in each non-immunized group. The presence of C1qB was observed in the junctional epithelium and adjacent connective tissue in the immunized groups. Heat-treated and sonicated S. aureus and A. actinomycetemcomitans induced attachment loss in rats immunized with their suspensions. Our results suggest that not only gram-negative but also gram

High resistance rate against 15 different antibiotics in aerobic gram-negative bacteria isolates of cardiology intensive care unit patients

Directory of Open Access Journals (Sweden)

Küçükates E

2002-01-01

Full Text Available Aerobic gram negative bacteria were isolated and examined microbiologically from various clinical samples of 602 patients hospitalized between January 1997 and December 2000 in surgical and coronary intensive care units (ICUs. A total of 827 isolates were obtained from 602 patients. The majority of microorganisms were isolated from the respiratory tract (50.3% and blood (39.9%. Pseudomonas spp. were the most frequently isolated gram negative species (32.7%, followed by Acinetobacter spp. (24.0% and Klebsiella pneumoniae (19.4%. High resistance rates to all antibiotics studied were observed. Imipenem and meropenem were the most effective antibiotics against gram negatives.

Expression levels of matrix metalloproteinase-9 and gram-negative bacteria in symptomatic and asymptomatic periapical lesions.

Science.gov (United States)

Ahmed, Geraldine M; El-Baz, Alaa A; Hashem, Ahmed Abdel Rahman; Shalaan, Abeer K

2013-04-01

The aim of this study was to test the hypothesis that the expression of matrix metalloproteinase (MMP)-9 is significantly elevated in patients with symptomatic apical periodontitis and to correlate this with the detected amount of gram-negative bacteria. Twenty-six patients with periapical lesions involving at least 2 teeth were included in this study. The patients were divided into 2 groups: the symptomatic (SYM) group included 13 patients expressing pain with periapical lesions, and the asymptomatic (ASYM) group included 13 patients expressing no pain. Root canal treatment was performed followed by endodontic surgery and periapical lesion collection. Periapical lesions were serially cut into 4-μ sections. Some sections were processed for histologic examination using hematoxylin-eosin stain. Other sections were processed for immunohistochemical examination. For MMP-9, the area fraction of the positive cells was measured, and the percentage of the MMP-9-immunopositive area to the total area of the microscopic field was calculated. For gram-negative stain cells, the number of cells showing the pink-red color was counted per microscopic field. The Student's t test was used to compare the SYM and ASYM groups. The Pearson correlation coefficient was used to determine a significant correlation between the number of cells and the MMP-9 level. The significance level was set at P ≤ .05. The SYM group showed a statistically significantly higher mean number of gram-negative cells (P = .001) and MMP-9 area percent (P < .001) than the ASYM group. There was a statistically significant positive (r = .927) correlation between the number of gram-negative cells and the MMP-9 area percent (P< .001). There is good evidence to suspect a significant role of gram-negative bacteria and MMP-9 in symptomatic periapical lesions. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Mucositis and oral infections secondary to gram negative rods in patients with prolonged neutropenia

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Mindy M. Sampson

2017-01-01

Full Text Available Patients with prolonged neutropenia are at risk for a variety of complications and infections including the development of mucositis and oral ulcers. The changes in oral flora during chemotherapy and its effects on the development of infections of the oral cavity have been studied with inconsistent results. However, there is evidence that supports the colonization of gram negative rods in patients undergoing chemotherapy. In this report, we present two leukemic patients who developed oral ulcers secondary to multi-drug resistant Pseudomonas aeruginosa. It is important to suspect multi-drug resistant gram negative rods in patients with prolonged neutropenia who develop gum infections despite appropriate antibiotic coverage.

Recovery of vancomycin-resistant gram-positive cocci from children.

OpenAIRE

Green, M; Wadowsky, R M; Barbadora, K

1990-01-01

A cross-sectional survey of vancomycin-resistant gram-positive cocci (VRGPC) in the feces of children was initiated after several bacteremic infections with these organisms occurred at our hospital. A selective medium consisting of colistin-nalidixic acid agar, 5% sheep blood, vancomycin (5 mg/liter), and amphotericin B (8 mg/liter) was developed to isolate VRGPC. A single stool specimen submitted to the clinical microbiology laboratory from each of 48 patients was inoculated onto the medium....

Resistant gram-negative bacilli and antibiotic consumption in zarqa, jordan

International Nuclear Information System (INIS)

Bataineh, H.A.; Alrashed, K.M.

2007-01-01

To investigate the prevalence of antibiotic resistance among gram-negative bacteria in relation to antibiotic use in Prince Hashem Hospital (PHH), Jordan. One hundred consecutive gram-negative bacterial isolates from different sites were collected from patients admitted to the ICU at PHH. The susceptibilities of the strains to 12 antibiotics were performed and interpreted. The quantities and the numbers of the patients discharged on antibiotics and the quantities consumed were obtained from the hospital pharmacy records. The most common isolate was P. aeruginosa (n=21) The most common site of isolation was the respiratory tract (65%), The highest susceptibility was to piperacillin/ tazobactam(78%), and the lowest was to cefuroxime(34%). The aminoglycosides gentamicin and amikacin were active against 71% and 73% of the isolates respectively, Ciprofloxacin was active against 75% of the isolates. The most frequently used antibiotics were the third-generation cephalosporins ceftriaxone and ceftazidime, followed by imipenem and amikacin. Antibiotic resistance surveillance programs associated with registration of antibiotic consumption are necessary to promote optimal use of antibiotics. Rational prescribing of antibiotics should be encouraged through educational programs, surveillance and audit. Proper infection control measures should be practiced to prevent horizontal transfer of drug-resistant organisms. (author)

Peptidoglycan architecture of Gram-positive bacteria by solid-state NMR.

Science.gov (United States)

Kim, Sung Joon; Chang, James; Singh, Manmilan

2015-01-01

Peptidoglycan is an essential component of cell wall in Gram-positive bacteria with unknown architecture. In this review, we summarize solid-state NMR approaches to address some of the unknowns in the Gram-positive bacteria peptidoglycan architecture: 1) peptidoglycan backbone conformation, 2) PG-lattice structure, 3) variations in the peptidoglycan architecture and composition, 4) the effects of peptidoglycan bridge-length on the peptidoglycan architecture in Fem mutants, 5) the orientation of glycan strands with respect to the membrane, and 6) the relationship between the peptidoglycan structure and the glycopeptide antibiotic mode of action. Solid-state NMR analyses of Staphylococcus aureus cell wall show that peptidoglycan chains are surprisingly ordered and densely packed. The peptidoglycan disaccharide backbone adopts 4-fold screw helical symmetry with the disaccharide unit periodicity of 40Å. Peptidoglycan lattice in the S. aureus cell wall is formed by cross-linked PG stems that have parallel orientations. The structural characterization of Fem-mutants of S. aureus with varying lengths of bridge structures suggests that the PG-bridge length is an important determining factor for the PG architecture. Copyright © 2014 Elsevier B.V. All rights reserved.

Nosocomial bloodstream infections in a Turkish university hospital: study of Gram-negative bacilli and their sensitivity patterns.

Science.gov (United States)

Köseoğlu , O; Kocagöz, S; Gür, D; Akova, M

2001-06-01

Treatment of nosocomial bacteraemia is usually governed by the surveillance results of the particular unit. Such results are especially important when antimicrobial resistance rates are high. Multiresistant isolates including Gram-negatives producing extended-spectrum beta-lactamases have been frequently reported in tertiary care units in Turkey. In this study, antimicrobial susceptibilities of Gram-negative blood isolates (n=348) were determined by microbroth dilution tests. The results showed carbapenems (meropenem and imipenem) to be uniformly more potent in vitro than any other drug against the Enterobacteriaceae. Quinolone antibiotics were more active in vitro than aminoglycosides against a range of bacteria. Gram-negative bloodstream isolates were highly resistant to many antimicrobial agents in the hospital. In order to prevent hospital infection and antimicrobial resistance, surveillance of aetiological agents must be performed regularly.

Distinction of Gram-positive and -negative bacteria using a colorimetric microbial viability assay based on the reduction of water-soluble tetrazolium salts with a selection medium.

Science.gov (United States)

Tsukatani, Tadayuki; Suenaga, Hikaru; Higuchi, Tomoko; Shiga, Masanobu; Noguchi, Katsuya; Matsumoto, Kiyoshi

2011-01-01

Bacteria are fundamentally divided into two groups: Gram-positive and Gram-negative. Although the Gram stain and other techniques can be used to differentiate these groups, some issues exist with traditional approaches. In this study, we developed a method for differentiating Gram-positive and -negative bacteria using a colorimetric microbial viability assay based on the reduction of the tetrazolium salt {2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium, monosodium salt} (WST-8) via 2-methyl-1,4-napthoquinone with a selection medium. We optimized the composition of the selection medium to allow the growth of Gram-negative bacteria while inhibiting the growth of Gram-positive bacteria. When the colorimetric viability assay was carried out in a selection medium containing 0.5µg/ml crystal violet, 5.0 µg/ml daptomycin, and 5.0µg/ml vancomycin, the reduction in WST-8 by Gram-positive bacteria was inhibited. On the other hand, Gram-negative bacteria produced WST-8-formazan in the selection medium. The proposed method was also applied to determine the Gram staining characteristics of bacteria isolated from various foodstuffs. There was good agreement between the results obtained using the present method and those obtained using a conventional staining method. These results suggest that the WST-8 colorimetric assay with selection medium is a useful technique for accurately differentiating Gram-positive and -negative bacteria.

Gram-scale production of a basidiomycetous laccase in Aspergillus niger.

Science.gov (United States)

Mekmouche, Yasmina; Zhou, Simeng; Cusano, Angela M; Record, Eric; Lomascolo, Anne; Robert, Viviane; Simaan, A Jalila; Rousselot-Pailley, Pierre; Ullah, Sana; Chaspoul, Florence; Tron, Thierry

2014-01-01

We report on the expression in Aspergillus niger of a laccase gene we used to produce variants in Saccharomyces cerevisiae. Grams of recombinant enzyme can be easily obtained. This highlights the potential of combining this generic laccase sequence to the yeast and fungal expression systems for large-scale productions of variants. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Kennedy's disease phenotype with positive genetic study for Kugelberg-Welander's disease: case report Fenótipo de doença de Kennedy com estudo genético positivo para doença de Kugelberg-Welander: relato de caso

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Ana P. Trentin

2005-06-01

Full Text Available We described a patient with clinical findings from Kennedy's disease and positive genetic study for Kugelberg-Welander's disease. A 24 years old man with negative family history presented with progressive spinal and bulbar muscular atrophy and gynecomastia at the age of 14. He was clinically diagnosed as having Kennedy's disease. However, a genetic study performed later was found to be negative for this disease and was positive for Kugelberg-Welander's disease, with deletion of the exons 7 and 8 in the "survival of motor neuron" gene.Descrevemos um paciente com achados clínicos de doença de Kennedy e estudo genético positivo para doença de Kugelberg-Welander. Homem, 24 anos e história familiar negativa, iniciou aos 14 anos com atrofia muscular espinhal de caráter progressivo com ginecomastia. Obteve diagnóstico clínico de doença de Kennedy, entretanto o estudo genético foi negativo para esta doença e positivo para doença de Kugelberg-Welander, com deleções dos exons 7 e 8 e do gene do survival of motor neuron.

Melting point gram-atomic volumes and enthalpies of atomization for liquid elements

International Nuclear Information System (INIS)

Lamoreaux, R.H.

1976-01-01

Values of the gram-atomic volumes and enthalpies of atomization to the monatomic ideal gas state for liquid elements at their melting points are collected to facilitate predictions of the behavior of mixed systems. Estimated values are given for experimentally undetermined quantities

Blue green alga mediated synthesis of gold nanoparticles and its antibacterial efficacy against Gram positive organisms

Energy Technology Data Exchange (ETDEWEB)

Uma Suganya, K.S. [Centre for Ocean Research, Sathyabama University, Chennai 600 119 (India); Govindaraju, K., E-mail: govindtu@gmail.com [Centre for Ocean Research, Sathyabama University, Chennai 600 119 (India); Ganesh Kumar, V.; Stalin Dhas, T.; Karthick, V. [Centre for Ocean Research, Sathyabama University, Chennai 600 119 (India); Singaravelu, G. [Nanoscience Division, Department of Zoology, Thiruvalluvar University, Vellore 632115 (India); Elanchezhiyan, M. [Department of Microbiology, Dr ALM Post Graduate Institute of Basic Medical Sciences, University of Madras, Chennai 600113 (India)

2015-02-01

Biofunctionalized gold nanoparticles (AuNPs) play an important role in design and development of nanomedicine. Synthesis of AuNPs from biogenic materials is environmentally benign and possesses high bacterial inhibition and bactericidal properties. In the present study, blue green alga Spirulina platensis protein mediated synthesis of AuNPs and its antibacterial activity against Gram positive bacteria is discussed. AuNPs were characterized using Ultraviolet–visible (UV–vis) spectroscopy, Fluorescence spectroscopy, Fourier Transform-Infrared (FTIR) spectroscopy, Raman spectroscopy, High Resolution-Transmission Electron Microscopy (HR-TEM) and Energy Dispersive X-ray analysis (EDAX). Stable, well defined AuNPs of smaller and uniform shape with an average size of ∼ 5 nm were obtained. The antibacterial efficacy of protein functionalized AuNPs were tested against Gram positive organisms Bacillus subtilis and Staphylococcus aureus. - Highlights: • Size controlled synthesis of gold nanoparticles from blue green alga Spirulina platensis • Stability of gold nanoparticles at different temperatures • Potent antibacterial efficacy against Gram positive organisms.

Peptidoglycan Recycling in Gram-Positive Bacteria Is Crucial for Survival in Stationary Phase

Science.gov (United States)

Borisova, Marina; Gaupp, Rosmarie; Duckworth, Amanda; Schneider, Alexander; Dalügge, Désirée; Mühleck, Maraike; Deubel, Denise; Unsleber, Sandra; Yu, Wenqi; Muth, Günther; Bischoff, Markus; Götz, Friedrich

2016-01-01

ABSTRACT Peptidoglycan recycling is a metabolic process by which Gram-negative bacteria reutilize up to half of their cell wall within one generation during vegetative growth. Whether peptidoglycan recycling also occurs in Gram-positive bacteria has so far remained unclear. We show here that three Gram-positive model organisms, Staphylococcus aureus, Bacillus subtilis, and Streptomyces coelicolor, all recycle the sugar N-acetylmuramic acid (MurNAc) of their peptidoglycan during growth in rich medium. They possess MurNAc-6-phosphate (MurNAc-6P) etherase (MurQ in E. coli) enzymes, which are responsible for the intracellular conversion of MurNAc-6P to N-acetylglucosamine-6-phosphate and d-lactate. By applying mass spectrometry, we observed accumulation of MurNAc-6P in MurNAc-6P etherase deletion mutants but not in either the isogenic parental strains or complemented strains, suggesting that MurQ orthologs are required for the recycling of cell wall-derived MurNAc in these bacteria. Quantification of MurNAc-6P in ΔmurQ cells of S. aureus and B. subtilis revealed small amounts during exponential growth phase (0.19 nmol and 0.03 nmol, respectively, per ml of cells at an optical density at 600 nm [OD600] of 1) but large amounts during transition (0.56 nmol and 0.52 nmol) and stationary (0.53 nmol and 1.36 nmol) phases. The addition of MurNAc to ΔmurQ cultures greatly increased the levels of intracellular MurNAc-6P in all growth phases. The ΔmurQ mutants of S. aureus and B. subtilis showed no growth deficiency in rich medium compared to the growth of the respective parental strains, but intriguingly, they had a severe survival disadvantage in late stationary phase. Thus, although peptidoglycan recycling is apparently not essential for the growth of Gram-positive bacteria, it provides a benefit for long-term survival. PMID:27729505

Black gram ( L. foliage supplementation to crossbred cows: effects on feed intake, nutrient digestibility and milk production

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Avijit Dey

2017-02-01

Full Text Available Objective An experiment was conducted to examine the effect of dietary supplementation of dried and ground foliage of black gram (Vigna mungo L. on feed intake and utilization, and production performance of crossbred lactating cows. Methods Eighteen lactating crossbred (Bos taurus×Bos indicus cows (body weight 330.93± 10.82 kg at their second and mid lactation (milk yield 6.77±0.54 kg/d were randomly divided into three groups of six each in a completely randomized block design. Three supplements were formulated by quantitatively replacing 0, 50, and 100 per cent of dietary wheat bran of concentrate mixture with dried and ground foliage of black gram. The designated supplement was fed to each group with basal diet of rice straw (ad libitum to meet the requirements for maintenance and milk production. Daily feed intake and milk yield was recorded. A digestion trial was conducted to determine the total tract digestibility of various nutrients. Results The daily feed intake was increased (p0.05, the fibre digestibility was increased (p0.05 among the groups, milk yield was increased by 10 per cent with total replacement of wheat bran in concentrate mixture with of black gram foliage. The economics of milk production calculated as feed cost per kg milk yield (INR 10.61 vs 7.98 was reduced by complete replacement of wheat bran with black gram foliage. Conclusion Black gram foliage could be used as complete replacement for wheat bran in concentrate mixture of dairy cows in formulating least cost ration for economic milk production in small holders’ animal production.

[Left-sided endocarditis due to gram-negative bacilli: epidemiology and clinical characteristics].

Science.gov (United States)

Noureddine, Mariam; de la Torre, Javier; Ivanova, Radka; Martínez, Francisco José; Lomas, Jose María; Plata, Antonio; Gálvez, Juan; Reguera, Jose María; Ruiz, Josefa; Hidalgo, Carmen; Luque, Rafael; García-López, María Victoria; de Alarcón, Arístides

2011-04-01

The aim of this study is to describe the epidemiological, clinical characteristics, and outcome of patients with left-side endocarditis caused by gram-negative bacteria. Prospective multicenter study of left-sided infective endocarditis reported in the Andalusian Cohort for the Study of Cardiovascular Infections between 1984 and 2008. Among the 961 endocarditis, 24 (2.5%) were caused by gram-negative bacilli. The most common pathogens were Escherichia coli, Pseudomonas aeruginosa and Salmonella enterica. Native valves (85.7%) were mainly affected, most of them with previous valve damage (57%). Comorbidity was greater (90% vs 39%; P=.05) than in endocarditis due to other microorganism, the most frequent being, diabetes, hepatic cirrhosis and neoplasm. A previous manipulation was found in 47.6% of the cases, and 37% were considered hospital-acquired. Renal failure (41%), central nervous system involvement (33%) and ventricular dysfunction (45%) were the most frequent complications. Five cases (21%) required cardiac surgery, mostly due to ventricular dysfunction. More than 50% of cases were treated with aminoglycosides, but this did not lead to a better outcome or prognosis. Mortality (10 patients) was higher than that reported with other microorganisms (41% vs 35%; P=.05). Left-sided endocarditis due to gram-negative bacilli is a rare disease, which affects patients with major morbidities and often with a previous history of hospital manipulations. Cardiac, neurological and renal complications are frequent and associated with a high mortality. The association of aminoglycosides in the antimicrobial treatment did not involve a better outcome or prognosis. Copyright © 2010 Elsevier España, S.L. All rights reserved.

Synergistic effect of Carum copticum and Mentha piperita essential oils with ciprofloxacin, vancomycin, and gentamicin on Gram-negative and Gram-positive bacteria

Science.gov (United States)

Talei, Gholam-Reza; Mohammadi, Mohsen; Bahmani, Mahmoud; Kopaei, Mahmoud Rafieian

2017-01-01

Background: Infectious diseases have always been an important health issue in human communities. In the recent years, much research has been conducted on antimicrobial effects of nature-based compounds because of increased prevalence of antibiotic resistance. The present study was conducted to investigate synergistic effect of Carum copticum and Mentha piperita essential oils with ciprofloxacin, vancomycin, and gentamicin on Gram-negative and Gram-positive bacteria. Materials and Methods: In this experimental study, the synergistic effects of C. copticum and M. piperita essential oils with antibiotics on Staphylococcus aureus (ATCC 25923), Enterococcus faecalis (ATCC 29212), Escherichia coli (ATCC 8739), Pseudomonas aeruginosa (ATCC 9027), Staphylococcus epidermidis (ATCC 14990), and Listeria monocytogenes (ATCC 7644) were studied according to broth microdilution and the MIC and fractional inhibitory concentration (FIC) of these two essential oils determined. Results: C. copticum essential oil at 30 μg/ml could inhibit S. aureus, and in combination with vancomycin, decreased MIC from 0.5 to 0.12 μg/ml. Moreover, the FIC was derived 0.24 μg/ml which represents a potent synergistic effect with vancomycin against S. aureus growth. C. copticum essential oil alone or combined with other antibiotics is effective in treating bacterial infections. Conclusions: In addition, C. copticum essential oil can strengthen the activities of certain antibiotics, which makes it possible to use this essential oil, especially in drug resistance or to lower dosage or toxicity of the drugs. PMID:28929050

earGram Actors: An Interactive Audiovisual System Based on Social Behavior

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Peter Beyls

2015-11-01

Full Text Available In multi-agent systems, local interactions among system components following relatively simple rules often result in complex overall systemic behavior. Complex behavioral and morphological patterns have been used to generate and organize audiovisual systems with artistic purposes. In this work, we propose to use the Actor model of social interactions to drive a concatenative synthesis engine called earGram in real time. The Actor model was originally developed to explore the emergence of complex visual patterns. On the other hand, earGram was originally developed to facilitate the creative exploration of concatenative sound synthesis. The integrated audiovisual system allows a human performer to interact with the system dynamics while receiving visual and auditory feedback. The interaction happens indirectly by disturbing the rules governing the social relationships amongst the actors, which results in a wide range of dynamic spatiotemporal patterns. A performer thus improvises within the behavioural scope of the system while evaluating the apparent connections between parameter values and actual complexity of the system output.

Probing the Penetration of Antimicrobial Polymyxin Lipopeptides into Gram-Negative Bacteria

Science.gov (United States)

2015-01-01

The dry antibiotic development pipeline coupled with the emergence of multidrug resistant Gram-negative ‘superbugs’ has driven the revival of the polymyxin lipopeptide antibiotics. Polymyxin resistance implies a total lack of antibiotics for the treatment of life-threatening infections. The lack of molecular imaging probes that possess native polymyxin-like antibacterial activity is a barrier to understanding the resistance mechanisms and the development of a new generation of polymyxin lipopeptides. Here we report the regioselective modification of the polymyxin B core scaffold at the N-terminus with the dansyl fluorophore to generate an active probe that mimics polymyxin B pharmacologically. Time-lapse laser scanning confocal microscopy imaging of the penetration of probe (1) into Gram-negative bacterial cells revealed that the probe initially accumulates in the outer membrane and subsequently penetrates into the inner membrane and finally the cytoplasm. The implementation of this polymyxin-mimetic probe will advance the development of platforms for the discovery of novel polymyxin lipopeptides with efficacy against polymyxin-resistant strains. PMID:24635310

Pulmonary Rhodococcus equi infection: report of the first two Brazilian cases

OpenAIRE

SEVERO, LUIZ CARLOS; RITTER, PATRICIA; PETRILLO, VICTOR FLÁVIO; DIAS, CÍCERO ARMÍDIO GOMES; PORTO, NELSON DA SILVA

2001-01-01

O Rhodococcus equi, principal agente da rodococose, é um cocobacilo pleomórfico, gram-positivo e aeróbio, que infecta humanos por via inalatória ou transcutânea e se manifesta clinicamente como abscesso pulmonar. Relatam-se os dois primeiros casos brasileiros da doença. Ambos os pacientes eram imunocomprometidos e apresentavam quadro infeccioso pulmonar. O primeiro tinha AIDS e apresentava pneumonia cavitada em lobo superior esquerdo, que teve evolução fatal. O segundo tinha doença de Goodpas...

ClubSub-P: Cluster-Based Subcellular Localization Prediction for Gram-Negative Bacteria and Archaea

Science.gov (United States)

Paramasivam, Nagarajan; Linke, Dirk

2011-01-01

The subcellular localization (SCL) of proteins provides important clues to their function in a cell. In our efforts to predict useful vaccine targets against Gram-negative bacteria, we noticed that misannotated start codons frequently lead to wrongly assigned SCLs. This and other problems in SCL prediction, such as the relatively high false-positive and false-negative rates of some tools, can be avoided by applying multiple prediction tools to groups of homologous proteins. Here we present ClubSub-P, an online database that combines existing SCL prediction tools into a consensus pipeline from more than 600 proteomes of fully sequenced microorganisms. On top of the consensus prediction at the level of single sequences, the tool uses clusters of homologous proteins from Gram-negative bacteria and from Archaea to eliminate false-positive and false-negative predictions. ClubSub-P can assign the SCL of proteins from Gram-negative bacteria and Archaea with high precision. The database is searchable, and can easily be expanded using either new bacterial genomes or new prediction tools as they become available. This will further improve the performance of the SCL prediction, as well as the detection of misannotated start codons and other annotation errors. ClubSub-P is available online at http://toolkit.tuebingen.mpg.de/clubsubp/ PMID:22073040

Identification of aerobic Gram-positive bacilli by use of Vitek MS.

Science.gov (United States)

Navas, Maria; Pincus, David H; Wilkey, Kathy; Sercia, Linda; LaSalvia, Margaret; Wilson, Deborah; Procop, Gary W; Richter, Sandra S

2014-04-01

The accuracy of Vitek MS mass spectrometric identifications was assessed for 206 clinically significant isolates of aerobic Gram-positive bacilli representing 20 genera and 38 species. The Vitek MS identifications were correct for 85% of the isolates (56.3% to the species level, 28.6% limited to the genus level), with misidentifications occurring for 7.3% of the isolates.

La «Gramàtica Valenciana» de Manuel Sanchis Guarner

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Antoni Ferrando

2015-10-01

Full Text Available This article studies Sanchis Guarner's Gramàtica Valenciana, trying to assess its relevant contribution, referring not only to the author's ideology and established goal, but also to its historical context and to its Catalan as well as Valencian precedents, like Fabra on one side, and Fullana, Giner and Salvador, on the other.

Cardiolipin, a major phospholipid of gram-positive bacteria that is not readily extractable

NARCIS (Netherlands)

Filgueiras, M.H.; Kamp, J.A.F. op den

1980-01-01

Extraction of phospholipids from stationary phase grown cells of the Gram+ bacteria, Bacillus megaterium, Bacillus subtilis, Bacillus cereus and Micrococcus lysodeikticus was found to be incomplete with various commonly used extraction procedures. Phosphatidylglycerol and phosphatidyl-ethanolamine

Características morfo-tintoriales en el ciclo celular de Acinetobacter baumannii por los métodos de Gram y 4’, 6-diamidino-2’-fenilindol, dihidrocloruro | Morphological and staining characteristics in cell cycle of Acinetobacter baumannii by the methods of Gram and 4´, 6-diamidino-2´-phenylindole, dihydrochloride

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Evelin Flores Hernández

2017-11-01

Full Text Available Several studies have reported variations in bacterial staining by Gram, which are associated with the content of nucleic acids in the bacterial cell cycle. In order to give continuity to the microscopical studies pertaining to the bacterial cell cycle, the morphological and staining characteristics were evaluated by Gram and 4', 6-diamidino-2'-phenylindole, dihydrochloride (DAPI in the cell cycle of Acinetobacter baumannii. From the synchronic cultures of 4 strains of A. baumannii, the cell cycle was studied incubating them in aerobiosis at 30ºC, taking aliquots every 5 min for 2 h. In turn, the respective extensions were made and stained with Gram and DAPI for their posterior microscopical study. In the statistical analysis Fischer's test was used to associate morphological and the staining characteristics by Gram and DAPI. In 74% of cycle times, the cocoid form predominated and 67% in the negative Gram staining. When determining the mean and standard deviation of bacterial morphological values, it was observed that between 15 and 55 min the bacterium initiates a new cell cycle, decreasing its diameter and length. There was a statistically significant association (p < 0.05 between the lax and compact appearance of the material with the light and intense fluorescent, respectively; likewise, between the strong Gram positive character and the intense fluorescence. It is concluded that in the Gram positive reaction, the DNA is possibly involved and that the purple material of compact and lax aspect observed by Gram staining in the bacterial cytoplasm correspond to the nucleoid and the morphological changes obey to the cellular growth process. These findings contribute to explain the mechanism of Gram staining, as well as its variability and the pleomorphism observed in this bacterial genus.

Impact of Gram stain results on initial treatment selection in patients with ventilator-associated pneumonia: a retrospective analysis of two treatment algorithms

OpenAIRE

Yoshimura, Jumpei; Kinoshita, Takahiro; Yamakawa, Kazuma; Matsushima, Asako; Nakamoto, Naoki; Hamasaki, Toshimitsu; Fujimi, Satoshi

2017-01-01

Background Ventilator-associated pneumonia (VAP) is a common and serious problem in intensive care units (ICUs). Several studies have suggested that the Gram stain of endotracheal aspirates is a useful method for accurately diagnosing VAP. However, the usefulness of the Gram stain in predicting which microorganisms cause VAP has not been established. The purpose of this study was to evaluate whether a Gram stain of endotracheal aspirates could be used to determine appropriate initial antimicr...

Lipopolysaccharide biogenesis and transport at the outer membrane of Gram-negative bacteria.

Science.gov (United States)

Sperandeo, Paola; Martorana, Alessandra M; Polissi, Alessandra

2017-11-01

The outer membrane (OM) of Gram-negative bacteria is an asymmetric lipid bilayer containing a unique glycolipid, lipopolysaccharide (LPS) in its outer leaflet. LPS molecules confer to the OM peculiar permeability barrier properties enabling Gram-negative bacteria to exclude many toxic compounds, including clinically useful antibiotics, and to survive harsh environments. Transport of LPS poses several problems to the cells due to the amphipatic nature of this molecule. In this review we summarize the current knowledge on the LPS transport machinery, discuss the challenges associated with this process and present the solutions that bacterial cells have evolved to address the problem of LPS transport and assembly at the cell surface. Finally, we discuss how knowledge on LPS biogenesis can be translated for the development of novel antimicrobial therapies. This article is part of a Special Issue entitled: Bacterial Lipids edited by Russell E. Bishop. Copyright © 2016. Published by Elsevier B.V.

Rational approaches to the therapy of nosocomial infections caused by gram-positive microorganisms in cancer p

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V. V. Aginova

2017-01-01

Full Text Available Nosocomial infections caused by gram-positive organisms, including Staphylococcus aureus and enterococci (Enterococcus faecium and Enterococcus faecalis are steadily increasing in almost all clinics around the world. Cancer patients have a higher risk of hospital-acquired infections than non-cancer patients. Cancer patients are immunosuppressed due to increased use of broad-spectrum antibiotics and chemotherapy drugs, radiation therapy, surgery and use of steroids. This paper presents an analysis of resistance of gram-positive bacterial pathogens to antimicrobial agents to determine treatment strategy for cancer patients.

Reducción del miedo escénico y mejora del afecto positivo, la autoeficacia y el desempeño ante la actuación en público: un cuasi=experimento aplicando PNL

OpenAIRE

Serrano Leiva, Damaris

2015-01-01

Treball final de Grau en Psicologia. Codi: PS1048. Curs acadèmic 2014-2015 En este estudio, se llevó a cabo un cuasi-experimento con el fin de evaluar la eficacia de dos técnicas en Programación Neuro Linguística (PNL): anclas y submodalidades en la mejora del afecto positivo, autoeficacia y desempeño, y la reducción del miedo escénico y del afecto negativo en alumnos de teatro de la Escuela Municipal de Villarreal. Para ello, se establecieron dos condiciones: Un grupo experime...

The Mechanisms of Virulence Regulation by Small Noncoding RNAs in Low GC Gram-Positive Pathogens

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Stephanie Pitman

2015-12-01

Full Text Available The discovery of small noncoding regulatory RNAs (sRNAs in bacteria has grown tremendously recently, giving new insights into gene regulation. The implementation of computational analysis and RNA sequencing has provided new tools to discover and analyze potential sRNAs. Small regulatory RNAs that act by base-pairing to target mRNAs have been found to be ubiquitous and are the most abundant class of post-transcriptional regulators in bacteria. The majority of sRNA studies has been limited to E. coli and other gram-negative bacteria. However, examples of sRNAs in gram-positive bacteria are still plentiful although the detailed gene regulation mechanisms behind them are not as well understood. Strict virulence control is critical for a pathogen’s survival and many sRNAs have been found to be involved in that process. This review outlines the targets and currently known mechanisms of trans-acting sRNAs involved in virulence regulation in various gram-positive pathogens. In addition, their shared characteristics such as CU interaction motifs, the role of Hfq, and involvement in two-component regulators, riboswitches, quorum sensing, or toxin/antitoxin systems are described.

Activation of toll-like receptors 2 and 4 by gram-negative periodontal bacteria

NARCIS (Netherlands)

Kikkert, R.; Laine, M. L.; Aarden, L. A.; van Winkelhoff, A. J.

2007-01-01

BACKGROUND/AIMS: Periodontitis is a chronic infectious disease associated with a gram-negative subgingival microflora. Bacterial components stimulate, among other receptors, Toll-like receptor (TLR) 2 and/or TLR4. Accumulating evidence indicates that both qualitatively and quantitatively distinct

Microflora en semillas de frijol

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Jos\\u00E9 B. Membre\\u00F1o

2001-01-01

Full Text Available Microflora en semillas de frijol (Phaseolus vulgaris L.. Se estudió la microflora bacteriana presente en semillas de frijol y su relación con Xanthomonas campestris pv. phaseoli (Xcp, en 118 genotipos procedentes de VIDAC-98, INTA- Nicaragua, TARS-USDA e Isabela-P.R. Se utilizaron cinco métodos de aislamiento: semilla desinfectada con hipoclorito de sodio, semilla en caldo nutritivo refrigerada por una hora, dispersión de 0,1 ml de suspensión de semillas en medio sólido, siembra líquida de 1 ml de suspensión y semilla en caldo nutritivo, agitado y refrigerado por 24 horas. Se aislaron 104 colonias amarillas de 41 genotipos. Treinta y seis colonias fueron KOH positivo (Gram negativo, 68 negativo (Gram positivo y 34 hidrolizaron almidón. Las colonias de pigmentación amarilla resultaron no patogénicas bajo condiciones de invernadero. Estas se identificaron con el sistema BIOLOG como: Pantoea agglomerans (25, Xanthomonas campestris (2, Enterobacter agglomerans (2, Sphingomonas paucimobilis (2, Pseudomonas fluorescens y Flavimonas oryzihabitans. En adición, los genotipos portaron colonias con pigmentación distinta a la amarilla. En las pruebas de antagonismo se identificaron colonias con actividad de deoxyribonucleasa y de antibiosis a Xcp. De éstas, 15 colonias inhibieron a Xcp significativamente. Se identificaron los hongos Rhizoctonia solani, Penicillium spp., Fusarium spp., Aspergillus flavus, Rhizopus nigricans y Macrophomina phaseolina en un 52,9 % del total de genotipos evaluados

ISOLAMENTO E CARACTERIZAÇÃO DE STAPHLOCOCCUS XYLOSUS DE SALAMES COLONIAIS: UM ESTUDO PRELIMINAR

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Andréia CIROLINI

2009-12-01

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A pesquisa teve como objetivo isolar e caracterizar cepas de Staphylococcus xylosus de salames coloniais. As linhagens foram coletadas de 3 amostras de salames coloniais comercializadas na região central do RS. As culturas foram selecionadas em meio ágar Baird Parker e incubadas a 36°C por 48h. Foram isoladas 5 colônias de cada amostra para posterior caracterização através de coloração de Gram, teste de coagulase, catalase, crescimento a concentração de 10% e 15% de NaCl em ágar nutriente e crescimento à temperatura de 15°C e 45°C em caldo BHI (Brain Heart Infusion. Para identifi cação do micro-organismo foi aplicado o kit Api Staph (Biomérieux. Através das análises realizadas, as cepas apresentaram características típicas do Staphylococccus xylosus como Gram positivo, coagulase negativo e catalase positivo, crescimento sob as diferentes concentrações de NaCl e crescimento às temperaturas de 15°C e 45°C, sendo selecionadas para posterior identifi cação no kit Api Staph. Decorrido o tempo de 24h à 35°C - 37°C, efetuou-se a leitura e interpretação dos resultados, onde das 15 cepas isoladas, 2 cepas foram identificadas como Staphylococcus xylosus.

PREVALENCIA DE Staphylococcus epidermidis Y Staphylococcus aureus EN PACIENTES CON CONJUNTIVITIS

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P. Hernández-Rodríguez

2005-12-01

Full Text Available Con el fin de establecer la prevalencia de Staphylococcus epidermidis y Staphylococcus aureus en pacientes con conjuntivitis, se evaluaron clínica y bacteriológicamente 131 pacientes con diagnóstico clínico presuntivo de conjuntivitis. A cada participante se le tomó muestra de secreción ocular, para la coloración de Gram y cultivo; además, se probó la susceptibilidad de los aislamientos frente a Oxacilina (Ox, Gentamicina (GM, Vancomicina (Va, Trimetoprim Sulfamethoxazole (SXT, Tetraciclina (Te, Cefalothin (CF, Ceftriaxone (CRO y Ciprofloxacina (CIP. El 53% de los cultivos bacteriológicos fueron positivos, donde el 87% de los aislamientos correspondieron a Gram positivos, siendo los más frecuentes Staphylococcus epidermidis (43%, Staphylococcus aureus (30%, Streptococcus sp. (15%, Enterococcus (7%, Corynebacterium sp. 5%. Se observó multirresistencia frente a 3 ó más antibióticos en S. epidermidis (44% y S.aureus (42%. La alta frecuencia de estos microorganismos y la multirresistencia encontrada en este estudio, determinan la importancia que tienen, como posibles patógenos oculares, y la necesidad de implementar las pruebas de susceptibilidad bacteriana en el ámbito oftalmológico. Este es el primer estudio publicado en Colombia sobre la prevalencia de Staphylococcus epidermidis y Staphylococcus aureus en pacientes con conjuntivitis, el cual seguramente originará la iniciación de posteriores investigaciones, encaminadas a determinar el verdadero papel de estos microorganismos, en el proceso infeccioso ocular.

Comparison of TiO2 and ZnO nanoparticles for photocatalytic degradation of methylene blue and the correlated inactivation of gram-positive and gram-negative bacteria

International Nuclear Information System (INIS)

Barnes, Robert J.; Molina, Rodrigo; Xu Jianbin; Dobson, Peter J.; Thompson, Ian P.

2013-01-01

Titanium dioxide (TiO 2 ) and zinc oxide (ZnO) nanoparticles are important photocatalysts and as such have been extensively studied for the removal of organic compounds from contaminated air and water and for microbial disinfection. Despite much research on the effect of TiO 2 and ZnO nanoparticles on different bacterial species, uncertainties remain about which bacteria are more sensitive to these compounds. Very few studies have directly compared the toxicity of ZnO to TiO 2 under both light and dark conditions. In addition, authors investigating the photocatalytic inactivation of TiO 2 and ZnO nanoparticles on bacteria have failed to investigate the reactive oxygen species (ROS) generation of the nanoparticles, making it difficult to correlate killing action with the generation of ROS. In this study, three types of metal nanoparticle (ZnO 2 ) have been characterised and ROS production assessed through the degradation of methylene blue (MB). The photocatalytic killing potential of three nanoparticle concentrations (0.01, 0.1 and 1 g/L) was then assessed on four representative bacteria: two gram-positive (S. aureus and B. subtilis) and two gram-negative (E. coli and P. aeruginosa). Results showed that out of the three nanoparticles tested, the TiO 2 nanoparticles generated more ROS than the ZnO nanoparticles, corresponding to a greater photocatalytic inactivation of three of the four species of bacteria examined. The MB decomposition results correlated well with the bacterial inactivation results with higher TiO 2 nanoparticle concentrations leading to greater ROS production and increased loss of cell viability. Although producing less ROS than the TiO 2 nanoparticles under ultraviolet light, the ZnO nanoparticles were toxic to two of the bacterial species even under dark conditions. In this study, no correlation between cell wall type and bacterial inactivation was observed for any of the nanoparticles tested although both gram-positive bacteria were sensitive to

Study of bacterial meningitis in children below 5 years with comparative evaluation of gram staining, culture and bacterial antigen detection.

Science.gov (United States)

Yadhav Ml, Kala

2014-04-01

Bacterial meningitis is one of the most serious infections seen in infants and children, which is associated with acute complications and chronic morbidity. Infections of Central Nervous System (CNS) still dominate the scene of childhood neurological disorders in most of the developing tropical countries. To isolate, identify and determine the antibiotic susceptibility patterns of pathogens associated with bacterial meningitis. We also aimed to comparatively evaluate of Gram staining, culture and bacterial antigen detection in cerebrospinal fluid samples. Present comparative study included 100 CSF samples of children below the age of 5 years, who were clinically suspected meningitis cases. The samples were subjected to Gram staining, culture and Latex agglutination test (LAT). The organisms isolated in the study were characterized and antibiotic susceptibility test was done according to standard guidelines. It was done by using Gaussian test. Of the 100 cases, 24 were diagnosed as Acute bacterial meningitis (ABM) cases by. Gram staining, culture and latex agglutination test. 21 (87.5%) cases were culture positive, with 2 cases being positive for polymicrobial isolates. Gram staining was positive in 17 (70.53%) cases and LAT was positive in 18 (33.33%) cases. Streptococcus pneumoniae was the predominant organism which was isolated and it was sensitive to antibiotics. In the present study, male to female ratio was 1.27:1, which showed a male preponderance. With the combination of Gram staining, culture, and LAT, 100% sensitivity and specificity can be achieved (p Gram staining and LAT can detect 85% of cases of ABM. Bacterial meningitis is a medical emergency and making an early diagnosis and providing treatment early are life saving and they reduce chronic morbidity.

Preemptive antibiotic treatment based on gram staining reduced the incidence of ARDS in mechanically ventilated patients.

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Matsushima, Asako; Tasaki, Osamu; Shimizu, Kentaro; Tomono, Kazunori; Ogura, Hiroshi; Shimazu, Takeshi; Sugimoto, Hisashi

2008-08-01

Ventilator-associated pneumonia (VAP) is one of the major complications in the intensive care unit. VAP sometimes results in acute respiratory distress syndrome (ARDS), and the associated mortality is high. We hypothesized that preemptive antibiotic therapy based on results of bedside gram staining would reduce the incidence of VAP. Patients who were endotracheally intubated in our intensive care unit for more than 72 hours were included. Patients younger than 16 years of age or patients died because of brain death were excluded. The study was divided into two periods. During the first period, we used antibiotics according to the American Thoracic Society guidelines. During the second period, antibiotics were given according to the results of bedside gram staining even before radiographic infiltrate appeared. One hundred twenty-eight patients and 133 patients were included in the first and second periods, respectively. The incidence of VAP was significantly decreased in the second period (first period, 22%; second period, 9%, p gram staining significantly reduced the incidences of VAP and ARDS without an increase in the use of antibiotics.

EFECTOS POSITIVOS Y NEGATIVOS DE LOS MEDIOS DE COMUNICACIÓN SOCIAL

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Fernando Serpa Florez

1982-12-01

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Un tema amplio fue escogido por la Asociación Latinoamericana de Academias de Medicina. Estudiar los "Efectos Positivos y Negativos de los Medios de Comunicación Social".

En su conjunto, entre tales medios podríamos englobar el gesto y la palabra, que desde el comienzo de la humanidad han sido usados por el hombre para comunicarse. O incluír, con el descubrimiento de la escritura milenios después, la influencia de ésta sobre la evolución del hombre, cada vez mayor a medida que se fueron inventando técnicas para hacer más fácil su difusión, con la imprenta como paso gigantesco del progreso.

La cultura se ha enriquecido con estas adquisiciones (con la invención de la palabra podríamos aceptar que la sorprendente evolución de nuestra especie comenzó: "En el principio fue el verbo ... ". y al lado de los factores negativos que tales medios de comunicación han tenido sobre el hombre, sería necio negar que los factores favorables han sido superiores.

Desde luego, nuestra Asociación, al señalar tan ambiciosa meta, seguramente ha querido (trascendiendo las primeras fases de la vida social en la historia de la humanidad, en las que por centurias el aprendizaje se basó en la transmisión de los conocimientos por medio de leyendas y mitos que quedaron grabados en el inconsciente colectivo y luego, ya en la época histórica, gracias a la lectura, aumentando el acervo cultural de los pueblos con la
invención del libro que ha permitido conservar las enseñanzas y hacerlas llegar a los hombres en el trasegar tranquilo de las escuelas y las bibliotecas centrar nuestro interés e investigación sobre el impacto que está causando la revolución tecnológica al producir, en virtud principalmente de la electrónica, la "cultura de masas" con la invención del telégrafo, el teléfono, la radiofonía y, por último, la televisión.

En un comienzo fue la imitación, uniendo las percepciones del ojo y del o

Survival and detection of coliforms, Enterobacteriaceae, and gram-negative bacteria in Greek yogurt.

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Hervert, C J; Martin, N H; Boor, K J; Wiedmann, M

2017-02-01

Despite the widespread use of coliforms as indicator bacteria, increasing evidence suggests that the Enterobacteriaceae (EB) and total gram-negative groups more accurately reflect the hygienic status of high-temperature, short-time pasteurized milk and processing environments. If introduced into milk as postpasteurization contamination, these bacteria may grow to high levels and produce a wide range of sensory-related defects. However, limited information is available on the use and survival of bacterial hygiene indicators in dairy products outside of pasteurized fluid milk and cheese. The goal of this study was to (1) provide information on the survival of a diverse set of bacterial hygiene indicators in the low pH environment of Greek yogurt, (2) compare traditional and alternative detection methods for their ability to detect bacterial hygiene indicators in Greek yogurt, and (3) offer insight into optimal hygiene indicator groups for use in low-pH fermented dairy products. To this end, we screened 64 bacterial isolates, representing 24 dairy-relevant genera, for survival and detection in Greek yogurt using 5 testing methods. Before testing, isolates were inoculated into plain, 0% fat Greek yogurt (pH 4.35 to 4.65), followed by a 12-h hold period at 4 ± 1°C. Yogurts were subsequently tested using Coliform Petrifilm (3M, St. Paul, MN) to detect coliforms; Enterobacteriaceae Petrifilm (3M), violet red bile glucose agar and the D-Count (bioMérieux, Marcy-l'Étoile, France) to detect EB; and crystal violet tetrazolium agar (CVTA) to detect total gram-negative bacteria. Overall, the non-EB gram-negative isolates showed significantly larger log reductions 12 h after inoculation into Greek yogurt (based on bacterial numbers recovered on CVTA) compared with the coliform and noncoliform EB isolates tested. The methods evaluated varied in their ability to detect different microbial hygiene indicators in Greek yogurt. Crystal violet tetrazolium agar detected the highest

Detection of Extended Spectrum Beta-Lactamases Among Gram Negative Bacilli Recovered from Cattle Feces In Benin City, Nigeria

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Helen Oroboghae OGEFERE

2017-06-01

Full Text Available This study was carried out to determine the prevalence of extended spectrum beta-lactamase (ESBL among Gram negative bacteria isolated from cattle feces in Benin City, Nigeria. A total of 250 Gram negative bacteria isolates were recovered from cattle feces and were processed microbiologically using standard techniques. Emergent colonies were identified and antibacterial susceptibility tests were determined using Kirby-Bauer disk diffusion method. All bacterial isolates were screened for the presence of ESBL using the double-disc synergy method. A total of 37 (14.8% isolates were positive for ESBL, with 33 (13.2% indicated by ceftazidime, while only 4 (1.6% were indicated by both ceftazidime and cefotaxime (P < 0.0001. Of the Gram negative bacterial isolates recovered, Salmonella species was the most prevalent ESBL-producer with 55.0% prevalence (P = 0.0092, while no isolate of Pseudomonas aeruginosa produced ESBL. ESBL-positive isolates showed poor susceptibility to the tested antibacterial agents in comparison with non-ESBL-producers and imipenem was the most active antibiotic. The prevalence of ESBL among Gram negative bacilli recovered from cattle feces was 14.8%. The study advises prudent use of antibiotics in the treatment of cattle and harps on improved hygiene in managing cattle, as they are potential reservoirs of ESBL-producing organisms.

Case of Mycobacterium tuberculosis meningitis: Gram staining as a useful initial diagnostic clue for tuberculous meningitis.

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Kawakami, Sayoko; Kawamura, Yasuyosi; Nishiyama, Kyouhei; Hatanaka, Hiroki; Fujisaki, Ryuichi; Ono, Yasuo; Miyazawa, Yukihisa; Nishiya, Hajime

2012-12-01

A 32-year-old man was admitted to our hospital because of fever, headache, and loss of consciousness. Four days before admission, he had had difficulty speaking. On the day of admission, his colleague had found him to be unconscious and lying on his back. He was admitted to our hospital. The temperature at the eardrum was 35.2°C. Neurologic evaluation was negative. Computed tomography (CT) scan of the brain showed slight ventricular enlargement bilaterally. An X-ray film of the chest showed no abnormality. On the second hospital day, neck stiffness was noted. The cerebrospinal fluid (CSF) contained 870 white cells/μl, most of which were neutrophils; the glucose level in the CSF was 10 mg/dl, and the protein level was 140 mg/dl. Stained smears of the CSF, including Gram staining and India-ink preparations, disclosed no microorganisms. Capsular antigen tests for several bacteria were negative. Antimicrobial agents were started. However, by changing the microscope focus slightly while viewing Gram stains of the CSF, we could see brightened and Gram-positive bacilli that had been phagocytosed by neutrophils. This finding suggested the presence of Mycobacterium tuberculosis. Ziehl-Neelsen staining of the CSF and gastric juice revealed anti-acid bacilli. Polymerase chain reaction for M. tuberculosis in the gastric juice was positive. This case showed that Gram staining could be useful as an initial adjunct for the diagnosis of tuberculous meningitis, particularly when the CSF shows predominantly neutrocytic pleocytosis, but no other evidence of bacterial meningitis.

ClubSub-P: Cluster-based subcellular localization prediction for Gram-negative bacteria and Archaea.

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Nagarajan eParamasivam

2011-11-01

Full Text Available The subcellular localization of proteins provides important clues to their function in a cell. In our efforts to predict useful vaccine targets against Gram-negative bacteria, we noticed that misannotated start codons frequently lead to wrongly assigned subcellular localizations. This and other problems in subcellular localization prediction, such as the relatively high false positive and false negative rates of some tools, can be avoided by applying multiple prediction tools to groups of homologous proteins. Here we present ClubSub-P, an online database that combines existing subcellular localization prediction tools into a consensus pipeline from more than 600 proteomes of fully sequenced microorganisms. On top of the consensus prediction at the level of single sequences, the tool uses clusters of homologous proteins from Gram-negative bacteria and from Archaea to eliminate false positive and false negative predictions. ClubSub-P can assign the subcellular localization of proteins from Gram-negative bacteria and Archaea with high precision. The database is searchable, and can easily be expanded using either new bacterial genomes or new prediction tools as they become available. This will further improve the performance of the subcellular localization prediction, as well as the detection of misannotated start codons and other annotation errors. ClubSub-P is available online at http://toolkit.tuebingen.mpg.de/clubsubp/

A synbio approach for selection of highly expressed gene variants in Gram-positive bacteria.

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Ferro, Roberto; Rennig, Maja; Hernández-Rollán, Cristina; Daley, Daniel O; Nørholm, Morten H H

2018-03-08

The market for recombinant proteins is on the rise, and Gram-positive strains are widely exploited for this purpose. Bacillus subtilis is a profitable host for protein production thanks to its ability to secrete large amounts of proteins, and Lactococcus lactis is an attractive production organism with a long history in food fermentation. We have developed a synbio approach for increasing gene expression in two Gram-positive bacteria. First of all, the gene of interest was coupled to an antibiotic resistance gene to create a growth-based selection system. We then randomised the translation initiation region (TIR) preceding the gene of interest and selected clones that produced high protein titres, as judged by their ability to survive on high concentrations of antibiotic. Using this approach, we were able to significantly increase production of two industrially relevant proteins; sialidase in B. subtilis and tyrosine ammonia lyase in L. lactis. Gram-positive bacteria are widely used to produce industrial enzymes. High titres are necessary to make the production economically feasible. The synbio approach presented here is a simple and inexpensive way to increase protein titres, which can be carried out in any laboratory within a few days. It could also be implemented as a tool for applications beyond TIR libraries, such as screening of synthetic, homologous or domain-shuffled genes.

Antimicrobial resistance in Gram-positive bacteria from Timorese River Buffalo (Bubalus bubalis) skin microbiota.

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Oliveira, Manuela; Monteiro, José L; Rana, Sílvia; Vilela, Cristina L

2010-06-01

The Timorese River Buffalo (Bubalus bubalis) plays a major role in the East Timor economy, as it is an important source of animal protein in human nutrition. They are widely spread throughout the country and are in direct contact with the populations. In spite of this proximity, information on their microbiota is scarce. This work aimed at characterizing the skin microbiota of the East Timorese River Buffalo and its antimicrobial resistance profile. Skin swab samples were taken from 46 animals in surveys conducted in three farms located in "Suco de Nairete", Lospalos district, during July and August 2006. Bacteria were isolated and identified according to conventional microbiological procedures. A total of 456 isolates were obtained, including Gram-positive (n = 243) and Gram-negative (n = 213) bacteria. Due to their importance as potential pathogens and as vehicles for antimicrobial resistance transmission, Gram-positive cocci (n = 27) and bacilli (n = 77) isolates were further characterized, and their antimicrobial resistance profile determined by the disk diffusion method according to the Clinical and Laboratory Standards Institute guidelines. This study shows the high bacterial diversity of B. bubalis skin microbiota, representing an important first step towards understanding its importance and epidemiologic role in animal health. It also points out the potential role of these animals as vectors of antimicrobial resistant bacteria dissemination and the importance of antimicrobial resistance monitoring in developing countries.

Characterization of carbapenem-resistant Gram-negative bacteria from Tamil Nadu.

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Nachimuthu, Ramesh; Subramani, Ramkumar; Maray, Suresh; Gothandam, K M; Sivamangala, Karthikeyan; Manohar, Prasanth; Bozdogan, Bülent

2016-10-01

Carbapenem resistance is disseminating worldwide among Gram-negative bacteria. The aim of this study was to identify carbapenem-resistance level and to determine the mechanism of carbapenem resistance among clinical isolates from two centres in Tamil Nadu. In the present study, a total of 93 Gram-negative isolates, which is found to be resistant to carbapenem by disk diffusion test in two centres, were included. All isolates are identified at species level by 16S rRNA sequencing. Minimal inhibitory concentrations (MICs) of isolates for Meropenem were tested by agar dilution method. Presence of blaOXA, blaNDM, blaVIM, blaIMP and blaKPC genes was tested by PCR in all isolates. Amplicons were sequenced for confirmation of the genes. Among 93 isolates, 48 (%52) were Escherichia coli, 10 (%11) Klebsiella pneumoniae, nine (%10) Pseudomonas aeruginosa. Minimal inhibitory concentration results showed that of 93 suspected carbapenem-resistant isolates, 27 had meropenem MICs ≥ 2 μg/ml. The MIC range, MIC50 and MIC90 were 128 μg/ml, 0.12 and 16 μg/ml, respectively. Fig. 1 . Among meropenem-resistant isolates, E. coli were the most common (9/48, 22%), followed by K. pneumoniae (7/9, 77%), P. aeruginosa (6/10, 60%), Acinetobacter baumannii (2/2, 100%), Enterobacter hormaechei (2/3, 67%) and one Providencia rettgeri (1/1, 100%). PCR results showed that 16 of 93 carried blaNDM, three oxa181, and one imp4. Among blaNDM carriers, nine were E. coli, four Klebsiella pneumoniae, two E. hormaechei and one P. rettgeri. Three K. pneumoniae were OXA-181 carriers. The only imp4 carrier was P. aeruginosa. A total of seven carbapenem-resistant isolates were negatives by PCR for the genes studied. All carbapenem-resistance gene-positive isolates had meropenem MICs >2 μg/ml. Our results confirm the dissemination of NDM and emergence of OXA-181 beta-lactamase among Gram-negative bacteria in South India. This study showed the emergence of NDM producer in clinical isolates of E

Characterization of an Hfq dependent antisense sRNA in the Gram-positive human pathogen Listeria monocytogenes

DEFF Research Database (Denmark)

Nielsen, Jesper Sejrup; Lei Kristensen, Lisbeth; Hanghøj Chrisitansen, Mie

between sRNA and target mRNA rely on the RNA chaperone Hfq. Hfq is a ubiquitous protein found in almost all genres of bacterial life. However, so far its role as an RNA chaperone has only been described in Gram-negative species such as Escherichia coli and Salmonella (Vogel, J. 2009). We previously...... identified several Hfq-binding sRNAs in the Gram-positive human pathogen L. monocytogenes (Christiansen et al 2006). Through bioinformatics, we have identified a number of candidate targets for one of these sRNAs (LhrA). Here, we present the characterization of one of these targets. Our results suggest...

Micorrizas en gramíneas nativas: efecto de la fertilización fosfatada a largo plazo

OpenAIRE

García, Silvina; Pezzani, Fabiana; Rodríguez, Andrea; del Pino, Amabelia

2016-01-01

En Uruguay el campo natural (CN) es el ecosistema dominante, relevante para la producción ganadera extensiva. Está constituido principalmente por gramíneas, especies que muestran alta micorrización. Los contenidos de fósforo (P) del CN son bajos, por lo que se llevan a cabo prácticas de fertilización fosfatada. El impacto de esta práctica sobre la comunidad vegetal difiere entre especies. El objetivo del trabajo fue estudiar el efecto del P sobre la colonización micorrícica en dos gramíneas n...

Increased genetic variability for symbiotic nitrogen fixation in green gram (Vigna radiata L.)

International Nuclear Information System (INIS)

Rosaiah, G.; Kumari, D.S.; Satyanarayana, A.; Seenaiah, P.

1989-01-01

Full text: When green gram is planted after rice in Andhra Pradesh, its nitrogen fixation relies upon local rhizobia that have been able to survive the stress of 5-6 months submergence. No rhizobia strain isolated elsewhere was found superior to native rhizobia. Thus improvement of the host may be the only practicable way to improve nitrogen fixation. 15 mutants obtained from gamma irradiated green gram variety 'LGG 127' were tested along with the parent and the cultivar 'Pant Mung 2'. Nodule no. per plant was higher in the mutants. There was also considerable variation in dry weight of nodules per plant and in seed yield. However the number of nodules per plant showed no correlation with seed yield, nodule size may be more relevant. The N content of the shoots at anthesis was positively correlated with dry weight of nodules, seed protein % and seed yield per plant. (author)

Transformation and Stability of Cloned Polysaccharidase Genes in Gram-Positive Bacteria

OpenAIRE

EKİNCİ, Mehmet Sait

2014-01-01

Polysaccharidase genes from rumen bacteria were transferred to and expressed in ruminal and non-ruminal Gram-positive bacteria. The transformation efficiency and genetic stability of polysaccharidase genes in bacteria from different habitats were investigated. PCR amplification of cloned polysaccharidase genes from Escherichia coli, Lactococcus lactis, Enterococcus faecalis, Streptococcus sanguis and S. bovis strain 26 showed that rearrangement of plasmid and the gene fragment did not occur. ...

Cefepime restriction improves gram-negative overall resistance patterns in neonatal intensive care unit

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Orlei Ribeiro de Araujo

Full Text Available Antibiotic restriction can be useful in maintaining bacterial susceptibility. The objective of this study was verify if restriction of cefepime, the most frequently used cephalosporin in our neonatal intensive care unit (NICU, would ameliorate broad-spectrum susceptibility of Gram-negative isolates. Nine hundred and ninety-five premature and term newborns were divided into 3 cohorts, according to the prevalence of cefepime use in the unit: Group 1 (n=396 comprised patients admitted from January 2002 to December 2003, period in which cefepime was the most used broad-spectrum antibiotic. Patients in Group 2 (n=349 were admitted when piperacillin/tazobactam replaced cefepime (January to December 2004 and in Group 3 (n=250 when cefepime was reintroduced (January to September 2005. Meropenem was the alternative third-line antibiotic for all groups. Multiresistance was defined as resistance to 2 or more unrelated antibiotics, including necessarily a third or fourth generation cephalosporin, piperacillin/tazobactam or meropenem. Statistics involved Kruskal-Wallis, Mann-Whitney and logrank tests, Kaplan-Meier analysis. Groups were comparable in length of stay, time of mechanical ventilation, gestational age and birth weight. Ninety-eight Gram-negative isolates were analyzed. Patients were more likely to remain free of multiresistant isolates by Kaplan-Meier analysis in Group 2 when compared to Group 1 (p=0.017 and Group 3 (p=0.003. There was also a significant difference in meropenem resistance rates. Cefepime has a greater propensity to select multiresistant Gram-negative pathogens than piperacillin/tazobactam and should not be used extensively in neonatal intensive care.

Ultrastructure, inferred porosity, and gram-staining character of Methanospirillum hungatei filament termini describe a unique cell permeability for this archaeobacterium

International Nuclear Information System (INIS)

Beveridge, T.J.; Sprott, G.D.; Whippey, P.

1991-01-01

By light microscopy, Methanospirillum hungatei GP1 stains gram positive at the terminal ends of each multicellular filament and gram negative at all regions in between. This phenomenon was studied further by electron microscopy and energy-dispersive X-ray spectroscopy of Gram-stained cells, using a platinum compound to replace Gram's iodine. Crystal violet-platinum precipitates could be found only in the terminal cells of each filament, which suggested that the multilamellar plugs at the filament ends were involved with stain penetration. When sheaths were isolated by sodium dodecyl sulfate-dithiothreitol treatment, the end plugs could be ejected and their layers could be separated from one another by 0.1 M NaOH treatment. Each plug consisted of at least three individual layers; two were particulate and possessed 14.0-nm particles hexagonally arranged on their surfaces with a spacing of a = b = 18.0 nm, whereas the other was a netting of 12.5-nm holes with spacings and symmetry identical to those of the particulate layers. Optical diffraction and computer image reconstruction were used to clarify the structures of each layer in an intact plug and to provide a high-resolution image of their interdigitated structures. The holes through this composite were three to six times larger than those through the sheath. Accordingly, we propose that the terminal plugs of M. hungatei allow the access of larger solutes than does the sheath and that this is the reason why the end cells of each filament stain gram positive whereas more internal cells are gram negative. Intuitively, since the cell spacers which partition the cells from one another along the filament contain plugs identical in structure to terminal plugs, the diffusion of large solutes for these cells would be unidirectional along the filament-cell axis

Secretory phospholipase A2 in dromedary tears: a host defense against staphylococci and other gram-positive bacteria.

Science.gov (United States)

Ben Bacha, Abir; Abid, Islem

2013-03-01

The best known physiologic function of secreted phospholipase A2 (sPLA2) group IIA (sPLA2-IIA) is defense against bacterial infection through hydrolytic degradation of bacterial membrane phospholipids. In fact, sPLA2-IIA effectively kills Gram-positive bacteria and to a lesser extent Gram-negative bacteria and is considered a major component of the eye's innate immune defense system. The antibacterial properties of sPLA2 have been demonstrated in rabbit and human tears. In this report, we have analyzed the bactericidal activity of dromedary tears and the subsequently purified sPLA2 on several Gram-positive bacteria. Our results showed that the sPLA2 displays a potent bactericidal activity against all the tested bacteria particularly against the Staphylococcus strains when tested in the ionic environment of tears. There is a synergic action of the sPLA2 with lysozyme when added to the bacteria culture prior to sPLA2. Interestingly, lysozyme purified from dromedary tears showed a significant bactericidal activity against Listeria monocytogene and Staphylococcus epidermidis, whereas the one purified from human tears displayed no activity against these two strains. We have also demonstrated that Ca(2+) is crucial for the activity of dromedary tear sPLA2 and to a less extent Mg(2+) ions. Given the presence of sPLA2 in tears and intestinal secretions, this enzyme may play a substantial role in innate mucosal and systemic bactericidal defenses against Gram-positive bacteria.

Flavins mediate extracellular electron transfer in Gram-positive Bacillus megaterium strain LLD-1

DEFF Research Database (Denmark)

You, Le-Xing; Liu, Li-Dan; Xiao, Yong

2018-01-01

The extracellular electron transfer (EET) mechanism of an isolated Gram-positive Bacillus megaterium strain (LLD-1), identified by 16S rRNA gene sequencing and physiological analysis, was investigated in the present study. The electrochemical activity of strain LLD-1 was confirmed by electrochemi...

DMPD: Lipopolysaccharide sensing an important factor in the innate immune response toGram-negative bacterial infections: benefits and hazards of LPShypersensitivity. [Dynamic Macrophage Pathway CSML Database

Lifescience Database Archive (English)

Full Text Available se toGram-negative bacterial infections: benefits and hazards of LPShypersensitivity. Freudenberg MA, Tchapt...portant factor in the innate immune response toGram-negative bacterial infections: benefits and hazards of L...une response toGram-negative bacterial infections: benefits and hazards of LPShyp

Design, Synthesis and Evaluation of Branched RRWQWR-Based Peptides as Antibacterial Agents Against Clinically Relevant Gram-Positive and Gram-Negative Pathogens

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Sandra C. Vega

2018-03-01

Full Text Available Multidrug resistance of pathogenic bacteria has become a public health crisis that requires the urgent design of new antibacterial drugs such as antimicrobial peptides (AMPs. Seeking to obtain new, lactoferricin B (LfcinB-based synthetic peptides as viable early-stage candidates for future development as AMPs against clinically relevant bacteria, we designed, synthesized and screened three new cationic peptides derived from bovine LfcinB. These peptides contain at least one RRWQWR motif and differ by the copy number (monomeric, dimeric or tetrameric and structure (linear or branched of this motif. They comprise a linear palindromic peptide (RWQWRWQWR, a dimeric peptide (RRWQWR2KAhx and a tetrameric peptide (RRWQWR4K2Ahx2C2. They were screened for antibacterial activity against Enterococcus faecalis (ATCC 29212 and ATCC 51575 strains, Pseudomonas aeruginosa (ATCC 10145 and ATCC 27853 strains and clinical isolates of two Gram-positive bacteria (Enterococcus faecium and Staphylococcus aureus and two Gram-negative bacteria (Klebsiella pneumoniae and Pseudomonas aeruginosa. All three peptides exhibited greater activity than did the reference peptide, LfcinB (17–31, which contains a single linear RRWQWR motif. Against the ATCC reference strains, the three new peptides exhibited minimum inhibitory concentration (MIC50 values of 3.1–198.0 μM and minimum bactericidal concentration (MBC values of 25–200 μM, and against the clinical isolates, MIC50 values of 1.6–75.0 μM and MBC values of 12.5–100 μM. However, the tetrameric peptide was also found to be strongly hemolytic (49.1% at 100 μM. Scanning Electron Microscopy (SEM demonstrated that in the dimeric and tetrameric peptides, the RRWQWR motif is exposed to the pathogen surface. Our results may inform the design of new, RRWQWR-based AMPs.

Breeding high yielding varieties of pigeon pea, mungbean and black gram using induced mutations

International Nuclear Information System (INIS)

Pawar, S.E.; Wanjari, K.B.

1994-01-01

The present communication emphasis the developing of high yielding varieties of pigeon pea, mungbean and black gram using induced mutation with disease resistance in these crops. This would help in stabilisation of the higher yield potential

Mezclas de Alfalfa y Gramíneas en la Serie Sabana de Bogotá Tipo Franco Arcilloso.

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Chaverra Gil. Hernán

1960-06-01

Full Text Available En el Centro Nacional de Investigaciones Agrícolas, Tibaitatá, y en la serie de suelos Sabana de Bogotá, tipo frnaco arcilloso, se llevaron a cabo dos experimentos con mezclas de alfalfa y gramíneas. En el primer ensayo, se sembraron simultáneamente con la alfalfa, ryegrass inglés, rygrass anual y orchoso. Los métodos de siembra utilizados fueron: a alfalfa y gramíneas sembradas al voleo, b alfalfa y gramíneas en el mismo surco, c alfalfa y gramíneas en surcos alternos, d alfalfa en surcos y gramíneas al voleo y e alfalfa en surcos y trébol blanco al voleo. En el segundo experimento se sembró la alfalfa en surcos separados 25 cm. Después de establecida la alfalfa e inmediatamente después del 4° corte se sembraron al voleo las siguientes gramíneas: ryegrass inglés, rygrass anual, orchoro, festuca media, pasto cinta y pasto rescate. Las finalidades del estudio fueron las de valorar el comportamiento de las gramíneas en mezcla con la alfalfa, mediante la determinación progresiva de la composición botánica y el rendimiento de forraje seco de las mezclas. La siembra simultánea de ryegrass inglés y ryegrass anual con la alfalfa dio como resultado una mala población de la leguminosa, especialmente en los dos primeros cortes. La competencia ejercida por estas dos gramíneas a la alfalfa, se redujo casi completamente, cuando se sembraron en surcos alternos o en la alfalfa establecida. Sea cual fuere el pasto sembrado, la siembra de gramíneas en alfalfa establecida, redujo la competencia entre los pastos asociados. En este ensayo el factor más importante en el establecimiento de las gramíneas, fue el agua disponible en el suelo. Bajo las condiciones del primer experimento el orchoro fue la gramínea que mejor creció en asocio de la alfalfa en todos los métodos de siembra estudiado. La producción promedia de la mezcla varió entre 2600 y 3145 Kg/hect. De forreje seco por corte y la proporción de orchoro entre

Late-onset granulomatous prostatitis following intravesical bacille Calmette-Guerin therapy: case report

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Octavio Castillo Cádiz

2016-06-01

Full Text Available Resumen El bacilo de Calmette-Guerin es el tratamiento intravesical más efectivo para disminuir la recurrencia de los carcinomas uroteliales no-músculo-invasivos. La aplicación de este tratamiento en ocasiones puede presentar efectos secundarios y, excepcionalmente, complicaciones graves. La prostatitis granulomatosa es un hallazgo histológico frecuente pero una entidad rara desde el punto de vista clínico. Se presenta el caso de un paciente de 75 años, diabético tipo 2, que fue diagnosticado de carcinoma in situ vesical, para lo cual inició tratamiento con bacilo de Calmette-Guerin intravesical. El paciente consultó cinco años después por presentar cuadro de nicturia, frecuencia miccional aumentada, urgencia miccional grave y dolor perineal intenso y recurrente asociado a una curva de antígeno prostático específico con marcada elevación. Se le realizó biopsia prostática que mostró una prostatitis crónica granulomatosa de grado moderado a grave relacionada a bacilo de Calmette-Guerin. El paciente recibió esquema antituberculoso completo con buena respuesta clínica.

Risk score for identifying adults with CSF pleocytosis and negative CSF Gram stain at low risk for an urgent treatable cause

NARCIS (Netherlands)

Hasbun, Rodrigo; Bijlsma, Merijn; Brouwer, Matthijs C.; Khoury, Nabil; Hadi, Christiane M.; van der Ende, Arie; Wootton, Susan H.; Salazar, Lucrecia; Hossain, Md Monir; Beilke, Mark; van de Beek, Diederik

2013-01-01

We aimed to derive and validate a risk score that identifies adults with cerebrospinal fluid (CSF) pleocytosis and a negative CSF Gram stain at low risk for an urgent treatable cause. Patients with CSF pleocytosis and a negative CSF Gram stain were stratified into a prospective derivation (n = 193)

O-antigen protects gram-negative bacteria from histone killing.

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Catherine Chaput

Full Text Available Beyond their traditional role of wrapping DNA, histones display antibacterial activity to Gram-negative and -positive bacteria. To identify bacterial components that allow survival to a histone challenge, we selected resistant bacteria from homologous Escherichia coli libraries that harbor plasmids carrying pieces of the chromosome in different sizes. We identified genes required for exopolysaccharide production and for the synthesis of the polysaccharide domain of the lipopolysaccharide, called O-antigen. Indeed, O-antigen and exopolysaccharide conferred further resistance to histones. Notably, O-antigen also conferred resistance to histones in the pathogens Shigella flexneri and Klebsiella pneumoniae.

The effect of mutagens on M1 population of black gram (Vigno ...

African Journals Online (AJOL)

Ramya

2014-02-19

Feb 19, 2014 ... This study was carried out with black gram (urdbean) variety TNAUCo(Bg)6 to determine the effects of gamma rays (150, 200, 250, 300 and 350 Gy) and ethyl methane sulphonate (10, 15, 20, 25, 30 mM). Data collected were on seed germination and survival, pollen and seed fertility, plant height, number of.

In vitro Efficacy of Meropenem, Colistin and Tigecycline Against the Extended Spectrum Beta-Lactamase Producing Gram Negative Bacilli

International Nuclear Information System (INIS)

Gill, M. M.; Usman, J.; Hassan, A.; Kaleem, F.; Anjum, R.

2015-01-01

Objective:To compare the in vitroefficacy of meropenem, colistin and tigecycline against extended spectrum Betalactamase producing Gram negative bacilli by minimal inhibitory concentration. Study Design:Cross-sectional descriptive study. Place and Duration of Study: Department of Microbiology, Army Medical College, National University of Sciences and Technology, Rawalpindi, from June to December 2010. Methodology: Routine clinical specimens were subjected to standard microbiological procedures and the isolates were identified to species level. Extended spectrum beta-lactamase producing Gram negative bacilli were detected by Jarlier disc synergy method and confirmed by ceftazidime and ceftazidime-clavulanate Etest. Minimum Inhibitory Concentration (MIC90) of meropenem, colistin and tigecycline was determined by Etest (AB BIOMERIUX) and the results were interpreted according to the manufacturer's instructions and Clinical and Laboratory Standards Institute guidelines and Food and Drug Authority recommendations. Results were analyzed by using Statistical Package for the Social Sciences version 20. Results: A total of 52 non-duplicate extended spectrum Beta-lactamase-producing Gram negative bacilli were included in the study. The MIC90 of tigecycline (0.75 micro g/ml) was lowest as compared to the meropenem (2 micro g/ml) and colistin (3 micro g/ml). Conclusion: Tigecycline is superior in efficacy against the extended spectrum Beta-lactamase producing Gram negative bacilli as compared to colistin and meropenem. (author)

Estudio molecular mediante reacción en cadena de la polimerasa y análisis de heteroduplex para el gen de la resistencia a la Rifampicina en Micobacterium tuberculosis

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P. Salcedo

2001-07-01

Full Text Available El Micobacterium tuberculosis, es un bacilo intracelular gramnegativo, facultativo, no esporulado, aerobio estricto, de crecimiento lento y que requiere medio de cultivo complejo para su aislamiento y caracterización. La tuberculosis es una infección que cursa con diversas manifestaciones clínicas teniendo como órgano blanco el pulmón y amplia distribució mundial. El bacilo muestra resistencia o multiresistencia a los tratamientos convencionales. El objetivo del presente trabajo, mediante PCR y el análisis de Heteroduplex de una región del gen rpoB de M. tuberculosis, es detectar las cepas resistentes a la rifampicina.

Tuberculosis

OpenAIRE

Latorre Tortello, Pablo

2011-01-01

Por definición, la tuberculosis pulmonar es la localizaci6n del M. tuberculosis en el tracto respiratorio, la forma más común y principal de la afección y la única capaz de contagiar a otras personas. El M. tuberculosis, descubierto por Robert Koch en 1882, el bacilo de Koch, es un bacilo delgado, inmóvil, de 4 micras de longitud media, aerobio obligado, que se tiñe de rajo por la tinción de Ziehl-Neelsen. Debido a la coraza lipídica de su pared, lo hace resistente a la decoloración con ácido...

Tuberculosis

OpenAIRE

Pablo Latorre Tortello

1998-01-01

Por definición, la tuberculosis pulmonar es la localizaci6n del M. tuberculosis en el tracto respiratorio, la forma más común y principal de la afección y la única capaz de contagiar a otras personas. El M. tuberculosis, descubierto por Robert Koch en 1882, el bacilo de Koch, es un bacilo delgado, inmóvil, de 4 micras de longitud media, aerobio obligado, que se tiñe de rajo por la tinción de Ziehl-Neelsen. Debido a la coraza lipídica de su pared, lo hace resistente a la decoloración con ácido...

Perfiles de resistencia a fluoroquinolonas en aislamientos clínicos de cocos Gram positivos provenientes de hospitales colombianos, 1994-2004

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César A. Arias

2008-06-01

Conclusión. Los aislamientos colombianos de S. pneumoniae mantienen susceptibilidad a las fluoroquinolonas de última generación. La resistencia a fluoroquinolonas es alta en S. aureus, especialmente en aislamientos resistentes a la meticilina (cercana al 100%.

A synbio approach for selection of highly expressed gene variants in Gram-positive bacteria

DEFF Research Database (Denmark)

Ferro, Roberto; Rennig, Maja; Hernández Rollán, Cristina

2018-01-01

with a long history in food fermentation. We have developed a synbio approach for increasing gene expression in two Gram-positive bacteria. First of all, the gene of interest was coupled to an antibiotic resistance gene to create a growth-based selection system. We then randomised the translation initiation...... region (TIR) preceding the gene of interest and selected clones that produced high protein titres, as judged by their ability to survive on high concentrations of antibiotic. Using this approach, we were able to significantly increase production of two industrially relevant proteins; sialidase in B....... subtilis and tyrosine ammonia lyase in L. lactis. Gram-positive bacteria are widely used to produce industrial enzymes. High titres are necessary to make the production economically feasible. The synbio approach presented here is a simple and inexpensive way to increase protein titres, which can be carried...

Relative uptake of technetium 99m stannous colloid by neutrophils and monocytes is altered by gram-negative infection

International Nuclear Information System (INIS)

Ramsay, Stuart C.; Maggs, Jacqueline A.; Ketheesan, Natkunam; Norton, Robert; LaBrooy, Justin

2005-01-01

Gram-negative infection alters phagocytic cell function; hence, it could affect phagocytic uptake of inorganic colloids by these cells. Neutrophil and monocyte uptake of technetium 99m stannous colloid ( 99m Tc SnC) in whole blood was measured in 10 patients with gram-negative infection (Burkholderia pseudomallei) and 7 controls. Mean uptake per individual neutrophil was reduced in infection. Uptake per monocyte was not significantly different. Blood from six normal individuals was incubated with lysed B. pseudomallei and colloid, which showed reduced neutrophil uptake, but increased monocyte uptake. These results indicate that uptake of 99m Tc SnC stannous colloid can be used to measure alteration in phagocytic cell function. They suggest that infection with B. pseudomallei is associated with reduced phagocytosis by individual neutrophils, possibly through toxic effects of bacterial products. This could have immunopathogenic consequences for this gram-negative infection and may explain why it responds to granulocyte colony-stimulating factor

Antibacterial properties of biosurfactants against selected Gram-positive and -negative bacteria.

Science.gov (United States)

Díaz De Rienzo, Mayri A; Stevenson, Paul; Marchant, Roger; Banat, Ibrahim M

2016-01-01

The antibacterial properties and ability to disrupt biofilms of biosurfactants (rhamnolipids, sophorolipids) and sodium dodecyl sulphate (SDS) in the presence and absence of selected organic acids were investigated. Pseudomonas aeruginosa PAO1 was inhibited by sophorolipids and SDS at concentrations >5% v/v, and the growth of Escherichia coli NCTC 10418 was also inhibited by sophorolipids and SDS at concentrations >5% and 0.1% v/v, respectively. Bacillus subtilis NCTC 10400 was inhibited by rhamnolipids, sophorolipids and SDS at concentrations >0.5% v/v of all three; the same effect was observed with Staphylococcus aureus ATCC 9144. The ability to attach to surfaces and biofilm formation of P. aeruginosa PAO1, E. coli NCTC 10418 and B. subtilis NCTC 10400 was inhibited by sophorolipids (1% v/v) in the presence of caprylic acid (0.8% v/v). In the case of S. aureus ATCC 9144, the best results were obtained using caprylic acid on its own. It was concluded that sophorolipids are promising compounds for the inhibition/disruption of biofilms formed by Gram-positive and Gram-negative microorganisms and this activity can be enhanced by the presence of booster compounds such as caprylic acid. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Mechanism of action of recombinant acc-royalisin from royal jelly of Asian honeybee against gram-positive bacteria.

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Lirong Shen

Full Text Available The antibacterial activity of royalisin, an antimicrobial peptide from the royal jelly produced by honeybees, has been addressed extensively. However, its mechanism of action remains unclear. In this study, a recombinant royalisin, RAcc-royalisin from the royal jelly of Asian honeybee Apis cerana cerana, was expressed by fusing with glutathione S-transferase (GST in Escherichia coli BL21, isolated and purified. The agar dilution assays with inhibition zone showed that RAcc-royalisin, similar to nisin, inhibits the growth of Gram-positive bacteria. The antibacterial activity of RAcc-royalisin was associated with its concentration, and was weakened by heat treatment ranging from 55°C to 85°C for 15 min. Both RAcc-royalisin and nisin exhibited the minimum inhibitory concentrations (MIC of 62.5 µg/ml, 125 µg/ml, and 250 µg/ml against Gram-positive bacterial strains, Bacillus subtilis and Micrococcus flavus and Staphyloccocus aureus in the microplate assay, respectively. However, RAcc-royalisin did not show antimicrobial activity against tested Gram-negative bacterial and fungal strains. The antibacterial activity of RAcc-royalisin agrees well with the decrease in bacterial cell hydrophobicity, the leakage of 260-nm absorbing materials, and the observation by transmission electron microscopy, all indicating that RAcc-royalisin induced the disruption and dysfunction of cell walls and membranes. This is the first report detailing the antibacterial mechanism of royalisin against Gram-positive bacteria, and provides insight into the application of recombinant royalisin in food and pharmaceutical industries as an antimicrobial agent.

Antimicrobial Resistance in Gram-Negative Rods Causing Bacteremia in Hematopoietic Stem Cell Transplant Recipients

DEFF Research Database (Denmark)

Averbuch, Diana; Tridello, Gloria; Hoek, Jennifer

2017-01-01

Background: This intercontinental study aimed to study gram-negative rod (GNR) resistance in hematopoietic stem cell transplantation (HSCT). Methods: GNR bacteremias occurring during 6 months post-HSCT (February 2014-May 2015) were prospectively collected, and analyzed for rates and risk factors...

Emerging Gram negative resistance to last-line antimicrobial agents fosfomycin, colistin and ceftazidime-avibactam - epidemiology, laboratory detection and treatment implications.

Science.gov (United States)

Sherry, Norelle; Howden, Benjamin

2018-04-01

Multidrug-resistant (MDR) and extensively-drug-resistant (XDR) Gram-negative bacteria have emerged as a major threat to human health globally. This has resulted in the 're-discovery' of some older antimicrobials and development of new agents, however resistance has also rapidly emerged to these agents. Areas covered: Here we describe recent developments in resistance to three of the most important last-line antimicrobials for treatment of MDR and XDR Gram negatives: fosfomycin, colistin and ceftazidime-avibactam. Expert commentary: A key challenge for microbiologists and clinicians using these agents for treating patients with MDR and XDR Gram negative infections is the need to ensure appropriate reference methods are being used to test susceptibility to these agents, especially colistin and fosfomycin. These methods are not available in all laboratories meaning accurate results are either delayed, or potentially inaccurate as non-reference methods are employed. Combination therapy for MDR and XDR Gram negatives is likely to become more common, and future studies should focus on the clinical effects of monotherapy vs combination therapy, as well as validation of synergy testing methods. Effective national and international surveillance systems to detect and respond to resistance to these last line agents are also critical.

Retrospective Analysis of Blood Stream Infections and Antibiotic Susceptibility Pattern of Gram Negative Bacteria in a Tertiary Care Cancer Hospital

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Radha Rani D

2017-12-01

Full Text Available Background: Bacterial bloodstream infections are important causes of morbidity and mortality globally. The aim of the present study was to determine the bacterial profile of bloodstream infections and their antibiotic susceptibility pattern among the clinically diagnosed cases of sepsis in cancer patients. Methods: In the present study, etiological and antimicrobial susceptibility profile of blood cultures over a period of 1 year at a tertiary cancer care hospital was done. Blood culture positive isolates were identified using standard microbiological methods and by Fully automated BD Phoenix 100. The antibiotic susceptibility pattern of the organisms was performed by Kirby-Bauer disc diffusion method and MIC (Minimum inhibitory concentration was done by Fully automated BD Phoenix 100. Results: There were 1178 blood culture samples, of which 327 (27.7% were identified to be culture positive. Out of 327 positive cultures, 299 (91.4% showed bacterial growth, Gram negative were 161 (53.8% and Gram positive were 138 (46.1%. Candida species were isolated from 13 (3.97% of positive samples and 15 samples showed contamination. The most common Gram-negative isolate was. Escherichia coli (37.80% and Gram-positive isolate was coagulasenegative staphylococci (52.80%. Escherichia coli showed highest sensitivity to amikacin (83.60% and sensitivity to piperacillin+ tazobactum and cefaperazone+sulbactam was 54.09% and 52.45% respectively. High degree of resistance was found to cephalosporins and levofloxacin. Conclusion: The results indicate high level of antimicrobial resistance among Gram negative bacilli in septicemic patients. The results warrant continuous monitoring of antimicrobial pattern so as to build geographical epidemiological data.

The gram-negative bacterial periplasm: Size matters.

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Samuel I Miller

2018-01-01

Full Text Available Gram-negative bacteria are surrounded by two membrane bilayers separated by a space termed the periplasm. The periplasm is a multipurpose compartment separate from the cytoplasm whose distinct reducing environment allows more efficient and diverse mechanisms of protein oxidation, folding, and quality control. The periplasm also contains structural elements and important environmental sensing modules, and it allows complex nanomachines to span the cell envelope. Recent work indicates that the size or intermembrane distance of the periplasm is controlled by periplasmic lipoproteins that anchor the outer membrane to the periplasmic peptidoglycan polymer. This periplasm intermembrane distance is critical for sensing outer membrane damage and dictates length of the flagellar periplasmic rotor, which controls motility. These exciting results resolve longstanding debates about whether the periplasmic distance has a biological function and raise the possibility that the mechanisms for maintenance of periplasmic size could be exploited for antibiotic development.

Trends of Bloodstream Infections in a University Greek Hospital during a Three-Year Period: Incidence of Multidrug-Resistant Bacteria and Seasonality in Gram-negative Predominance.

Science.gov (United States)

Kolonitsiou, Fevronia; Papadimitriou-Olivgeris, Matthaios; Spiliopoulou, Anastasia; Stamouli, Vasiliki; Papakostas, Vasileios; Apostolopoulou, Eleni; Panagiotopoulos, Christos; Marangos, Markos; Anastassiou, Evangelos D; Christofidou, Myrto; Spiliopoulou, Iris

2017-07-06

The aim of the study was to assess the epidemiology, the incidence of multidrug-resistant bacteria and bloodstream infections' (BSIs) seasonality in a university hospital. This retrospective study was carried out in the University General Hospital of Patras, Greece, during 2011-13 y. Blood cultures from patients with clinical presentation suggestive of bloodstream infection were performed by the BacT/ALERT System. Isolates were identified by Vitek 2 Advanced Expert System. Antibiotic susceptibility testing was performed by the disk diffusion method and E-test. Resistance genes (mecA in staphylococci; vanA/vanB/vanC in enterococci; bla KPC /bla VIM /bla NDM in Klebsiella spp.) were detected by PCR. In total, 4607 (9.7%) blood cultures were positive from 47451 sets sent to Department of Microbiology, representing 1732 BSIs. Gram-negative bacteria (52.3%) were the most commonly isolated, followed by Gram-positive (39.5%), fungi (6.6%) and anaerobes bacteria (1.8%). The highest contamination rate was observed among Gram-positive bacteria (42.3%). Among 330 CNS and 150 Staphylococcus aureus, 281 (85.2%) and 60 (40.0%) were mecA-positive, respectively. From 113 enterococci, eight were vanA, two vanB and two vanC-positives. Of the total 207 carbapenem-resistant Klebsiella pneumoniae (73.4%), 202 carried bla KPC , four bla KPC and bla VIM and one bla VIM . A significant increase in monthly BSIs' incidence was shown (R2: 0.449), which may be attributed to a rise of Gram-positive BSIs (R2: 0.337). Gram-positive BSIs were less frequent in spring (P period. The increasing incidence of BSIs can be attributed to an increase of Gram-positive BSI incidence, even though Gram-negative bacteria remained the predominant ones. Seasonality may play a role in the predominance of Gram-negative's BSI.