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Sample records for bacterias aerobias aisladas

  1. RESISTENCIA A ANTIBIOTICOS DE BACTERIAS AISLADAS DE BIOPELÍCULAS EN UNA PLANTA DE ALIMENTOS

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    María Vanegas L

    2009-08-01

    Full Text Available Objetivo. Evaluar la resistencia a antibióticos y la capacidad de formación de biopelículas de bacterias aisladas en una planta de producción de alimentos. Materiales y métodos. Se tomaron muestras de 3 zonas diferentes, en una planta procesadora de alimentos; en la lavadora de canastas, la mesa de producción y en la banda empacadora. Se aislaron e identificaron las bacterias presentes en cada una de las tres zonas y se determinó la capacidad formadora de biopelículas por medio de cuantificación celular. Asimismo se evaluó la resistencia de cada una de las bacterias aisladas frente a ocho diferentes antibióticos. Resultados. Se recuperaron 29 cepas, correspondientes a 13 géneros diferentes, los cuales fueron todos formadores de biopelículas. Se encontró que cerca del 50% de las bacterias aisladas fueron resistentes a antibióticos como la penicilina G y vancomicina. Adicionalmente se evidenció un alto grado de multirresistencia a los diferentes antibióticos. Conclusiones. La alta multirresistencia encontrada a antibióticos entre las bacterias analizadas podría ser un problema para salud pública ya que pueden ser transmitidas por alimentos. De igual manera es de gran importancia la capacidad de producción de biopelículas de la microbiota analizada así como la alta concentración de bacterias entéricas y ambientales, lo que sugiere deficiencia del programa de limpieza y desinfección de la planta.

  2. Proteasas extracelulares producidas por bacterias marinas aisladas de aguas contaminadas con efluentes pesqueros

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    Tito Sánchez

    2013-06-01

    Full Text Available Un total de 26 cepas de bacterias marinas con actividad proteolítica fueron aisladas de agua de mar contaminadas con efluentes pesqueros; las mismas que se evaluaron en base al crecimiento y formación de halos de actividad en Agar Marino suplementados con caseína al 1%, pH 8,0 e incubados a 25 ºC por 72 h. Cinco cepas, seleccionadas por presentar los mejores halos de actividad fueron evaluadas a su vez por su crecimiento y producción de proteasas a diferentes concentraciones de NaCl, rangos de temperatura y pH; siendo consideradas finalmente como bacterias halotolerantes, psicrotróficas y alcalófilas moderadas. Estas cepas también fueron evaluadas por su actividad proteolítica específica sobre la caseína, siendo la cepa CM48 (Pseudomonas sp. la que presentó la mejor actividad específica (17,38 U/mg a las 72 horas, y seguidas por las cepas CM45 (Alcaligenes sp. (12,09 U/mg y tres cepas de Aeromonas sp. (CM43, CM44 y CM46 con valores de 12,02; 10,07 y 10,10 U/mg respectivamente.

  3. Evaluation of Petrifilm™ method for enumerating aerobic bacteria in Crottin goat's cheese Evaluación de PetrifilmTM para la enumeración de bacterias aerobias en queso de cabra Crottin

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    G.B. de Sousa

    2005-12-01

    Full Text Available The PetrifilmTM Aerobic Count Plate (ACP developed by 3M laboratories, is a ready-to-use culture medium system, useful for the enumeration of aerobic bacteria in food. PetrifilmTMwas compared with a standard method in several different food products with satisfactory results. However, many studies showed that bacterial counts in PetrifilmTM were significantly lower than those obtained with conventional methods in fermented food. The purpose of this study was to compare the PetrifilmTM method for enumerating aerobic bacteria with a conventional method (PCA in Crottin goat's cheese. Thirty samples were used for the colony count. The mean count and standard deviation were 7.18 ± 1.17 log CFU g-1 on PCA and 7.11 ± 1.05 log CFU g-1 on PetrifilmTM. Analysis of variance revealed no significant differences between both methods (t = 1.33, P = 0.193. The Pearson correlation coefficient (0.971, P=0.0001 indicated a strong linear relationship between the PetrifilmTM and the standard method. The results showed that PetrifilmTM is suitable and a convenient alternative to this standard method for the enumeration of aerobic flora in goat soft cheese.PetrifilmTM Aerobic Count Plate (ACP desarrollado por 3M es un sistema listo para usar, empleado para el recuento de bacterias aerobias en alimentos. PetrifilmTMfue comparado con los métodos estándar en diferentes productos alimenticios con resultados satisfactorios. Sin embargo, en alimentos fermentados, algunos estudios mostraron que el recuento de bacterias aerobias en PetrifilmTM fue significativamente menor que aquellos obtenidos con los métodos convencionales (PCA. El propósito de este estudio fue comparar el método PetrifilmTM para el recuento de bacterias aerobias con un método convencional en queso de cabra Crottin. Se usaron 30 muestras para el recuento de colonias. Las medias y desviaciones estándar fueron 7,18 ± 1,17 log UFC g-1 en PCA y 7,11 ± 1,05 log UFC g-1 en PetrifilmTM. El análisis de

  4. Biodegradación del explosivo tetranitrato de pentaeritritol (PETN por bacterias aisladas de ambientes mineros

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    Yerson Durán

    2013-12-01

    Full Text Available El tetranitrato de pentaeritritol (PETN es el detonante más energético y recalcitrante empleado en la actividad minera ya que posee cuatro grupos nitro unidos mediante enlaces éster; además es un contaminante orgánico persistente según el Convenio de Estocolmo. En el presente trabajo es evaluada la eficiencia de degradación del PETN por bacterias aisladas de ambientes mineros. En primer lugar se seleccionó las cepas con mayor crecimiento durante tres subcultivos en medio mínimo con PETN como única fuente de nitrógeno. Luego, se identificó mediante análisis del gen RNAr 16S las cepas Bacillus sp. J8A2 y Enterobacter sp. M1B. Las velocidades específicas de crecimiento fueron de 0.057 h -1 para J8A2 y 0.042 h -1 para M1B, y las velocidades específicas de degradación de 0.72 y 1.16 mmol de PETN/g de proteína.h, respectivamente. Además, el extracto crudo de la cepa J8A2 mostró una actividad específica (U de 1.03 mmol de PETN/h y una actividad específica por proteína (U/g de 138.6 mmol de PETN/g.h.

  5. Evaluación in vitro de sustancias antibacterianas producidas por bacterias aisladas de diferentes organismos marinos

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    Isabel Castillo

    2001-12-01

    Full Text Available Se realizaron antibiogramas directos para detectar la presencia de bacterias productoras de sustancias antibacterianas aisladas de diferentes organismos marinos, utilizando el patógeno de humanos Staphylococcus aureus ATCC6538 como germen revelador. Alas bacterias que produjeron sustancias inhibidoras del crecimiento del germen revelador se les realizó pruebas morfológicas, fisiológicas y bioquímicas en función de identificarlas a nivel de género. De un total de 290 cepas 54 (18.6 % inhibieron el crecimiento del germen revelador, pero sólo 27 se mantuvieron viables. Los grupos más representativos de donde se aislaron las bacterias productoras de sustancias antibacterianas fueron los moluscos bivalvos, las esponjas y corales, presentaron un 41.2, 33.3 y 29.7 %, respectivamente, de bacterias productoras relativas al número de sus aislados. Los organismos que presentaron una mayor proporción de bacterias inhibidoras del germen revelador se aislaron del coral Madracis decactis (62.5 %, la esponja Cliona sp. (57.1 %, y el octocoral Plexaura flexuosa (50.0 %. De las 27 cepas productoras de sustancias antibacterianas que se identificaron, 51.85 % pertenecieron al género Aeromonas y 14.8% al género Vibro. Los resultados muestran la abundancia de bacterias marinas productoras de sustancias antibacterianas, la mayoría de ellas pertenecientes al grupo de las vibrionáceas principalmente aisladas de corales y moluscos bivalvosBacteria from several groups of marine organisms were isolated and, using direct antibiograms, identified those that produce antibacterial substances, using a human pathogenic strain of Staphylococcus aureus ATCC6538 as revealing microorganism. Bacteria which produce substances that inhibite S. aureus growth were identified through morphological, physiological and biochemical tests. Out of 290 bacteria, 54 (18.6 % inhibited the growth of S. aureus, but only 27 survived for identification. Bivalves, sponges and corals were

  6. PRODUCCIÓN DE ENZIMAS EXTRACELLARES POR BACTERIAS AISLADAS DE INVERTEBRADOS MARINOS

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    Jorge León

    2014-06-01

    Full Text Available Con el fin de seleccionar las bacterias marinas con la capacidad de producir enzimas extracelulares ( CEE , se analizaron muestras de Argopecten purpuratus y Crassostrea gigas en el cultivo , así como de otros invertebrados interticlal y bentónicos. La selección de cepas de la CEE de productores se llevó a cabo en Agar Marino ( MA con la adición del sustrato relevante ( almidón , caseína , Tween - 80 , lecitina , ADN y gelatina . La CEE evaluación cepas productoras se llevó a cabo en 102 aislamientos . Los resultados muestran que las bacterias asociadas TOA . purpuratusand C. gigashave las mejores actividades multienzimáticos ; Sin embargo , Semimytilus algosus, Tetrapigus niger y Thais chocolata también son fuentes importantes de productores de bacterias de la CEE. La actividad multienzimático cualitativa en MA ( zonas claras u opacas alrededor de las colonias en mm de diámetro varió de 6 a > 16 mm . La frecuencia de la producción multienzimático fue caseinase 62,74 % , entre esterasa 57,84 % , 52,94 % de la amilasa , la gelatinasa 38,23 % , 33,3 % DNAsa , agarasa 5,43 % y 90,0 % lecitinasa . Los resultados sugieren la posibilidad de usar cepas nativas para fines biotecnológicos

  7. BACTERIAS AISLADAS DEL JUGO DE FIQUE CON ACTIVIDAD ANTAGÓNICA SOBREPhytophthora infestans (Mont. de Bary

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    IVAN DARIO OTERO R

    2014-06-01

    Full Text Available Phytophthora infestans (Mont. de Bary, causa pérdidas considerables en todas las áreas donde se cultivan Solanáceas. Su manejo se realizapor métodos químicos, biológicos y tradicionalmente por los agricultores utilizando jugo de fique. Se aislaron bacterias presentes en el jugo de fique y se evaluó el antagonismo contra P.infestans empleando el principio de la técnica de Bauer-Kirbyel. Se seleccionó el aislado con mayor inhibición para realizar una fermentación en jugo de fique estéril y pruebas de antagonismo contra P. infestans en cajas de agartomate enmendadas con caldo fermentado. Finalmente, se realizó la caracterización molecular del aislado seleccionado mediantela secuencia parcial del gen ribsomal 16S rRNA. Se obtuvo 41 aislados, de los cuales ocho presentaron inhibición del crecimiento In Vitro de P. infestans. Se seleccionó el aislado M46 para las pruebas de antagonismo en placas de agar tomate enmendadas con 200 µLde caldo fermentado y se alcanzó un porcentaje de inhibición del 95,4% del crecimiento de P. infestans. El aislado M46 se identificó como Bacillus spcon un porcentaje de identidad del 85% con B. cereus. La cepa de Bacillus spM46 tiene potencial como agente de control para el patógeno P.infestans.

  8. Susceptibilidad de las bacterias aisladas de infecciones gastrointestinales agudas a la rifaximina y otros agentes antimicrobianos en México

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    O. Novoa-Farías

    2016-01-01

    Conclusiones: La resistencia de las bacterias enteropatógenas a antimicrobianos utilizados en gastroenteritis es alta. La rifaximina fue activa contra el 99-100% de las bacterias en concentraciones alcanzables en el contenido intestinal con las dosis recomendadas.

  9. Caracterización de bacterias halófilas productoras de amilasas aisladas de las Salinas de San Blas en Junín

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    Pamela Elizabeth Canales Mormontoy

    2014-07-01

    Full Text Available Título en español: Caracterización de bacterias halófilas productoras de amilasas aisladas de las Salinas de San Blas en Junín Título en ingles: Characterization of halophilic bacteria producing amylase isolated from San Blas Salterns in Junin Título corto: Bacterias halófilas amilolíticas de las Salinas de San Blas Resumen:  El objetivo de este estudio fue caracterizar bacterias halófilas con actividad amilolítica provenientes de las Salinas de San Blas-Junín, ubicadas en los Andes peruanos aproximadamente a 4100 m de altitud. Este estudio se realizó con 34 bacterias aisladas de muestras de suelos las cuales se cultivaron en agar agua de sales (SW 5 % conteniendo extracto de levadura 0,5 % y almidón 1 %. El 41 % de bacterias mostró la capacidad de hidrolizar almidón, éstas fueron caracterizadas mediante pruebas fisiológicas y bioquímicas convencionales. Tres bacterias fueron Gram-negativas y once Gram-positivas. El 21 % (3/14 creció en un amplio rango de concentración de sales, entre 5 y 20 %. El 14 % (2/14 de las bacterias presentó actividad lipolítica, proteolítica y nucleolítica, y el 29 % (4/14, presentó actividad proteolítica y nucleolítica. Las bacterias se identificaron mediante los perfiles de restricción de los genes ribosómicos 16S amplificados, las enzimas usadas fueron Hae III, BstU I, Hinf I y Cfo I. Los genes ribosómicos 16S de siete bacterias que presentaron perfiles de ADN diferentes se amplificaron, secuenciaron y analizaron mediante programas bioinformáticos. Del análisis fenotípico y molecular de las 14 bacterias amilolíticas se obtuvieron dos grupos, uno perteneciente al género Halomonas (3 y el otro, al género Bacillus (11. Las bacterias amilolíticas caracterizadas podrían ser de potencial uso a nivel industrial.  Palabras clave: Salinas de San Blas, amilasas, genes ribosómicos 16S, ARDRA, Bacillus, Halomonas. Abstract: The aim of this study was to characterize halophilic

  10. Evaluación del potencial biofertilizante de bacterias diazótrofas aisladas de suelos con cultivo de cacao (Theobroma cacao L.

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    Adriana Zulay Argüello-Navarro

    2014-09-01

    Full Text Available La adaptabilidad del cacao (Theobroma cacao L. en condiciones adversas permite sugerir que la microbiota asociada con la rizosfera desempeña una función importante para la nutrición y el desarrollo de la planta. En el trabajo se evaluó el potencial biofertilizante de bacterias fijadoras de nitrógeno (diazótrofas aisladas de suelos cacaoteros por la técnica de diluciones seriadas. Las bacterias se aislaron en medios semiselectivos (NFb, JMV, LGI, JNFb. Los aislados puros se caracterizaron morfológica y bioquímicamente y complementariamente se evaluó la capacidad de fijación biológica de nitrógeno (FBN por el método de Micro-Kjeldahl. Los aislados con mejor capacidad de fijación de nitrógeno fueron seleccionados para evaluar su potencial promotor de crecimiento durante 120 días en plantas de cacao clon CCN 51 establecidas a partir de semillas. El análisis de datos mostró que las plantas de cacao respondieron efectivamente a los tratamientos con bacterias donde las variables de crecimiento y N (% foliar incrementaron significativamente, en comparación con el testigo. Se destacó el aporte de los aislados DKA2J24, DKB3J73 presuntamente del género Burkholderia sp. y DKA1L3 semejante al género Gluconacetobacter sp., todos con un gran potencial como biofertilizantes en la prueba de bioensayo.

  11. Potencial biofertilizante de bacterias diazótrofas aisladas de muestras de suelo rizosférico

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    Laura Y Moreno

    Full Text Available Las bacterias promotoras del crecimiento vegetal son capaces de adaptarse, colonizar y persistir en la rizosfera de la planta, lo cual favorece su crecimiento y desarrollo. En este trabajo se aislaron 32 cepas nativas de bacterias diazótrofas, a partir de muestras de suelo rizosférico de diferentes cultivos, identificadas mediante los medios de cultivo tradicionales y el sistema BBL CRYSTAL. La identificación bioquímica se realizó a través de la reacción en cadena de la polimerasa (PCR, del inglés Polymerase Chain Reaction. Nueve aislados se determinaron como Stenotrophomonas maltophilia y uno como Azotobacter vinelandii, de los cuales tres coincidieron en la identificación bioquímica y la molecular. Se realizó un ensayo en invernadero para evaluar el efecto fertilizante en plantas de maíz, según un diseño experimental de bloques al azar y nueve tratamientos, por triplicado: tratamiento 1: A. vinelandii ATCC 9046; tratamientos del 2 al 7 para los seis aislados; tratamiento 8 para fertilización química; y tratamiento 9 para suelo sin fertilización (testigo. Los aislados M8-10, M10-1 y M11-3, identificados como S. maltophilia por PCR, tuvieron mejores resultados en la emergencia de las plantas, el diámetro del tallo y la longitud de las hojas y los tallos. Finalmente se determinó que M10-1 mostró valores de emergencia y crecimiento de la planta por encima de la media y el límite superior, con respecto a los demás aislados y controles, lo cual lo convierte en un potencial biofertilizante.

  12. Antibiotic sensitivity of bacterial strains isolated from newborn infants Sensibilidad a los antibióticos de bacterias aisladas de neonatos hospitalizados

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    Alvaro Uribe

    1990-02-01

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    Eighty nine bacterial strains isolated from newborn infants hospitalized at a Special Care Unit in Medellin, Colombia, were studied. The sensitivity of each one was determined by the Minimallnhibitory Concentration method against 21 antibiotics; a high frequency of resistance was found toward gentamycin, netilmycin, oxacillin, penicillin G and ampicillin, that are often employed as initial therapy in newborn infants; on the other hand both Gram positive and Gram negative bacteria exhibited high percentages of sensitivity against quinolones; aztreonam and third generation cephalosporins were also highly effective against Gram negative bacilli. On the basis of this new information the need to restate therapeutic conducts in the case of serious bacterial neonatal infections is emphasized.

    Se estudiaron 89 cepas bacterianas aisladas de neonatos hospitalizados en la sala de cuidados especiales de la Fundación Hospitalaria San Vicente de Paúl, de Medellín; a cada una se le determinó la sensibilidad frente a 21 antibióticos por el método de la concentración inhibitoria mínima (CIM; se halló una alta frecuencia de resistencia hacia la gentamicina, la netilmicina, la oxacilina y la ampicilina que se usan a menudo en esta institución como terapia inicial en las infecciones del recién nacido; por otra parte se demostraron altos porcentajes de sensibilidad hacia las quinolonas tanto de las bacterias gram positivas como de las gram negativas; contra estas últimas también fueron muy efectivos el aztreonam y las cefalosporinas de tercera generación. A la luz de esta nueva información se llama la atención hacia la necesidad de revaluar las normas de la antibioterapia en las infecciones graves del recién nacido.

  13. CARACTERIZACIÓN DE BACTERIAS PROBIÓTICAS AISLADAS DEL INTESTINO GRUESO DE CERDOS COMO ALTERNATIVA AL USO DE ANTIBIÓTICOS

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    Henry Jurado G

    2009-08-01

    Full Text Available Objetivos. Caracterizar bacterias ácido lácticas probióticas aisladas del intestino grueso de cerdos adultos como posible alternativa al uso de antibióticos. Materiales y métodos. Se incluyeron muestras de intestino grueso de 20 cerdos adultos, para el aislamiento de bacterias lácticas (BAL. La caracterización de los parámetros bioquímicos-fisiológicos de las BAL contemplo la evaluación del pH del fermento, determinación de ácidos orgánicos por HPLC y detección de isómeros de ácido láctico. Los procedimientos microbiológicos evaluaron la capacidad de inhibición del crecimiento de patógenos y la actividad antagónica del probiótico vs antibiótico con su interacción competitiva. Se utilizaron pruebas API CHL 50 para la identificación de las BAL que se complementaron con la producción de gas, actividad de catalasa y viabilidad a diferentes concentraciones de sales biliares y temperaturas. Resultados. El plan de análisis permitió seleccionar dos aislados que se identificaron como: Lactobacillus plantarum 1 H1 y Lb. plantarum 1 H2. Las pruebas microbiológicas evidenciaron que las BAL seleccionadas inhibieron principalmente los enteropatógenos: Escherichia coli, Salmonella typhimurium y Clostridium perfringens. Las pruebas bioquímicas fueron compatibles con el género Lactobacillus, mostrando el siguiente perfil: Catalasa negativas; no productoras de gas; productoras de isómeros DL; resistentes a sales biliares y pH óptimo de crecimiento 3.5 a 38oC. Conclusiones. Los dos aislados de Lactobacillus plantarum 1 reunieron las características para el uso potencial como probióticos. Se recomienda su uso como complemento de terapias con antibióticos y en la elaboración de inóculos para aplicación en raciones alimenticias de lechones destetos, sin embargo, estudios complementarios se requieren para evaluar el efecto directo del probiótico como sustituto del uso de antibióticos in vivo.

  14. Resistencia a los antimicrobianos en bacterias indicadoras y zoonóticas aisladas de animales domésticos en Argentina Antimicrobial resistance in indicator and zoonotic bacteria isolated from domestic animals in Argentina

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    F. L. Pantozzi

    2010-02-01

    Full Text Available Se estudiaron los patrones de resistencia a diversos antimicrobianos en bacterias indicadoras y zoonóticas aisladas de muestras fecales de individuos sanos, sin signología clínica, pertenecientes a los siguientes grupos animales: bovinos, equinos, ovinos, porcinos, gallinas ponedoras y caninos. Los antimicrobianos seleccionados fueron los empleados con mayor frecuencia en medicina veterinaria y humana, y el método de evaluación utilizado fue el de difusión en agar con discos. Los resultados obtenidos a partir de 240 Escherichia coli, 189 Enterococcus spp., 11 Campylobacter spp. y 2 Salmonella Gaminara (16:d:1,7, revelaron un mayor porcentaje de resistencia y multirresistencia en porcinos y aves, esto es, en animales de cría intensiva. El perfil de resistencia observado en los aislamientos de E. coli incluyó a la ampicilina, la estreptomicina, la tetraciclina y el ácido nalidíxico, en coincidencia con los antimicrobianos más utilizados en las explotaciones animales, al igual que lo detectado en Enterococcus spp. respecto a la tetraciclina y la eritromicina. Las cepas de Salmonella Gaminara (16:d:1,7 fueron sensibles a todos los antimicrobianos probados. En Campylobacter spp., si bien el número de aislamientos evaluados fue reducido, se observó una mayor resistencia a tetraciclina y quinolonas. Teniendo en cuenta la falta de datos en nuestro país sobre resistencia a los antimicrobianos en bacterias indicadoras y zoonóticas en animales domésticos, consideramos que la información obtenida podría utilizarse como punto de partida para futuros programas de monitoreo.Antimicrobial resistance profiles in indicator and zoonotic bacteria isolated from faeces of healthy animals without clinical signs of the following species: bovine, equine, ovine, porcine, layer hens, and canine, were studied. The chosen antimicrobials are frequently used in veterinary and human medicine. The agar diffusion was the method used. The obtained results of 240

  15. Identificación de bacterias endofitas aisladas de Teocintle y Maíz con potencial para promover el crecimiento vegetal.

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    Flores Pantoja, Luis Enrique

    2016-01-01

    En este trabajo se pretende dar valor a las variedades de plantas locales de interés económico y a las poblaciones de bacterias endófitas asociadas a ellas, como un recurso natural importante que pueda ser aprovechado en la agricultura para brindar beneficios ambientales y económicos. Para esto, se aislaron bacterias endófitas de cortes desinfectados de la raíz de tres plantas de maíz con diferentes rasgos genéticos y se evaluó el efecto de tres cepas de interés en el crecimiento de maíz prie...

  16. Susceptibilidad a la rifaximina y otros antimicrobianos de bacterias aisladas en pacientes con infecciones gastrointestinales agudas en el sureste de México

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    O. Novoa-Farias

    2017-07-01

    Resultados: La mayoría de las bacterias fueron Escherichia coli (55% en todas sus variantes patógenas, Shigella (16.8%, Salmonella (15.3%, Aeromonas (7.8% y menos de 5% Campylobacter, Yersinia, Vibrio y Plesiomonas. La susceptibilidad global acumulada a RIF fue del 69.1, el 90.8, el 98.9 y el 100% a las concentraciones de 100, 200, 400 y 800 μg/ml, respectivamente. La susceptibilidad global a los otros antibióticos fue: FOS 82.8%, CLO 76.8%, CIP 73.9%, FUR 64%, T-S 58.7%, NEO 55.8% y AMP 23.8%. La susceptibilidad a RIF 400 y 800 μg fue significativamente mayor que con los otros antimicrobianos (p  98% de las cepas bacterianas y alta frecuencia de resistencia a varios antimicrobianos comunes.

  17. CAPACIDAD ANTIMICROBIANA DE BACTERIAS ÁCIDO LÁCTICAS AUTÓCTONAS AISLADAS DE QUESO DOBLE CREMA Y QUESILLO COLOMBIANO

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    MAYRA FUENTES VANEGAS

    2017-07-01

    Full Text Available Lactic Acid Bacteria (LAB native to have been reported as an efficient alternative for natural biopreservation, prevention of Foodborne Diseases (ETAS and improvement production processes of traditional fermented foods. The objective was to evaluate the antimicrobial capacity of native BAL isolated from Double Cream Cheese and Quesillo against the in vitro growth of Salmonella enterica subsp. enterica serovar Typhimurium ATCC 13311 and Listeria monocytogenes ATCC 7644. We studied 32 isolates, previously identified by analysis of 16S rDNA gene sequences and characterized technologically. We tested antimicrobial capacity using an agar spot test. Subsequently, cell-free supernatants were neutralized and filtered to detect their antimicrobial activity using the gel diffusion method by drilling plate. We selected 8 isolates showing inhibitory capacity against the two pathogens microorganisms. Isolated identified as Lactococcus lactis subsp. lactis Q5 presented higher activity, equivalent to 64.000 AU/ml for L. monocytogenes and 4.000 AU/ml for S. typhimurium. It is suggested that BAL from traditional cheeses produce antimicrobial substances Colombian bactericidal potential and can be used in formulating a starter culture with bioprotective effect.

  18. CONTROL BIOLÓGICO IN VITRO POR BACTERIAS ÁCIDO LÁCTICAS AISLADAS DE RESIDUOS DE CERVECERÍA

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    Gerbaldo G

    2012-07-01

    Full Text Available Los residuos de cervecería son suplementos de bajo costo y de fácil disponibilidad, sin embargo, el alto contenido de humedad los hace susceptibles a la degradación fúngica y al desarrollo de microorganismos patógenos. Las bacterias ácido lácticas (BAL se encuentran formando parte de la microbiota de los granos de cebada, de manera tal, que podrían contribuir en la calidad y seguridad tanto de la malta como de los pro- ductos derivados. El objetivo de este estudio fue determinar la presencia BAL, especies fúngicas de Aspergillus sección Flavi, Listeria monocytogenes e incidencia de aflatoxina B1 (AFB1 en residuos de cervecería, y evaluar in vitro el efecto antifúngico y anti-aflatoxicogénico de las BAL. El análisis de los residuos de cervecería mostró que, en general, los recuentos de BAL fueron elevados durante todos los períodos analizados, sin embargo, el recuento de Aspergillus sección Flavi, L. monocytogenes e incidencia natural de AFB1 fue variable. El hallazgo de L. monocytogenes es el primero informado en Argentina en este tipo de sustrato. Lactobacillus coryniformis subsp. coryniformis L47 y Lactobacillus cellobiosus L56 fueron las cepas más efectivas en inhibir el crecimiento y la producción de AFB1 de todas las cepas de Aspergillus sección Flavi ensayadas in vitro. Futuros estudios con estas cepas de BAL podrían realizarse para demostrar su efectividad in situ en estos sustratos alternativos destinados a la producción animal, así como también evaluar in vitro sus propiedades anti-listeria.

  19. Distribución de bacterias potencialmente fijadoras de nitrógeno y su relación con parámetros fisicoquímicos en suelos con tres coberturas vegetales en el sur de la Amazonia colombiana

    Directory of Open Access Journals (Sweden)

    Andrea J Mantilla-Paredes

    2009-12-01

    Full Text Available Se evaluó la abundancia y distribución de bacterias microaerófilas y aerobias potencialmente fijadoras de nitrógeno aisladas a partir de suelos bajo coberturas de bosque, pastizal y chagra en dos paisajes, terraza y llanura inundable, en el sur de trapecio amazónico. Se relacionó el recuento en placa en el medio Ashby de estas bacterias aerobias con las características físicas y químicas del suelo. Se encontró mayor abundancia de bacterias aerobias y microaerofilas en suelos bajo cobertura de pastizal. Se observó influencia directa del paisaje sobre la abundancia de bacterias microaerófilas registrando mayores recuentos los suelos bajo terraza en las coberturas de bosque y pastizal. Los aislamientos aerobios obtenidos (51 se agruparon en 19 morfologías, de las cuales se obtuvo mayor número en suelos bajo bosque y en el paisaje de llanura inundable. A través del análisis multidimensional no métrico (NMDS y análisis de similaridades (ANOSIM (pDistribution of potentially nitrogen-fixing bacteria and its relationship with physicochemical parameters in soils with three vegetation types in the southern Colombian Amazon region. Potentially nitrogen-fixing microaerobic and aerobic bacteria were isolated from several Colombian Amazon soils (forest, pastures and chagras and two landscapes (floodable and non floodable areas. The abundance and distribution of bacteria were evaluated, as well as their relationship with soil physical and chemical characteristics. Landscape had a direct influence on the abundance of the microaerobic bacteria, with higher numbers in forest and pasture soils in non- floodable zones. The aerobic isolates (N=51 were grouped into 19 morphologies, with the highest numbers found in forest soil in floodable zones. A higher number of aerobic morphologies was shared among forest sites (Nonmetric Multidimensional Scaling and Analysis of Similarity p<0.05, and 40% of the distribution was explained by lime percentage and

  20. AISLADA DE Cavia porcellus

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    H. Jurado-Gámez

    2014-01-01

    Full Text Available Se evaluó el efectoin vitrodeLactobacillus plantarumsobreYersinia pseudotuberculosisaislada de cuyes (Cavia porcellus e identificada bioquímica y molecularmente. Se deter-minó la viabilidad deL. plantaruma diferentes pH (3.25, 4.5, 7.6 y 8.2, sales biliaresbovinas (3, 4 y 5%, bilis bovina (0.5, 1 y 2% y temperatura (38 y 45°C. Se realizóantibiograma a ambas bacterias con Cefalotina, Cefepima, Ciprofloxacina, Dicloxacilina,Enrofloxacina, Gentamicina, Penicilina y Trimetropim-Sulfametoxasol. Se determina-ron los péptidos deL. plantarummediante HPLC y la cinética de crecimiento en dossustratos (MRS y Pro, midiéndose: biomasa, pH, consumo de azúcar total y ácidoláctico. Se observó un mejor crecimiento bajo pH 3.25, sales biliares 5%, bilis bovina2% y temperatura de 45°C con valores de 3.0·1012, 2.3·1012, 8.6·1011y 3.0·1012UFC/ml, respectivamente.L. plantarumy el sobrenadante inhibieron aY. pseudotuberculosis,con halos de 3 y 5 mm. Se observó resistencia deL. plantarumyY. pseudotuberculosisaPenicilina y Dicloxacilina, respectivamente, con sensibilidad de ambas cepas a los demásantibióticos. Se evidenciaron los péptidos VAL-TIR-VAL y TIR-GLI-GLI-FA-METen el sobrenadante deL. plantarum. Durante la fase logarítmica para los medios MRSy Pro se alcanzaron valores de 6.75·1012y 1.20·1012UFC/ml (biomasa, 6.96 y 5.49(pH, y 0.65 y 0.76%, (ácido láctico, respectivamente. La comparación de los mediosmediante un diseño de bloques al azar (P> 0.05, mostró similar comportamiento.L.plantarumdemostró su potencial probiótico en condicionesin vitro.

  1. Diazotrophic bacteria isolated from wild rice Oryza glumaepatula (Poaceae in the Brazilian Amazon Bacterias diazotróficas aisladas de arroz silvestre Oryza glumaepatula (Poaceae en la Amazonia brasileña

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    Paulo Ivan Fernandes Júnior

    2013-06-01

    Full Text Available The association of wild grasses with diazotrophic bacteria in Brazilian biomes is poorly understood. The isolation and characterization of bacteria associated with wild grasses can contribute to understand the diazotrophic ecology as well as to identify bacteria with biotechnological applications. In this study, we isolated and characterized diazotrophic bacterial isolates from Oryza glumaepatula collected in Cerrado and Forest areas of the Amazon in Roraima State, Brazil. Healthy O. glumepatula plants were collected at five sampling sites at Forest and seven at Cerrado, respectively. The plants were collected at the Cerrado areas in September 2008 while the Forest plants were collected in June/2008 and April/2009. The plants and the soil adhering to the roots were transferred to pots and grown for 35 days in greenhouse conditions. During the harvest, the shoots and the roots were crushed separately in a saline solution; the suspension was diluted serially and inoculated in Petri dishes containing Dyg’s medium. All distinct bacterial colonies were purified in the same medium. The diazotrophic capacity of each bacterium in microaerophilic conditions was assessed in semisolid BMGM medium. In addition, the pellicles forming bacterial isolates were also evaluated by PCR amplification for nifH gene. The diversity of nifH+ bacteria was analyzed by Box-PCR fingerprinting. For selected strains, the growth promoting capacity of O. sativa as a model plant was also evaluated. A total of 992 bacterial isolates were obtained. Fifty- one bacteria were able to form pellicles in the semisolid medium and 38 also positively amplified the 360bp nifH gene fragment. Among the 38 nifH+ isolates, 24 were obtained from the shoots, while 14 originated from the roots. The Box-PCR profiles showed that the bacterial isolates obtained in this study presented a low similarity with the reference strains belonging to the Herbaspirillum, Azospirillum and Burkholderia genus

  2. Evaluación de la diversidad de bacterias degradadoras de hidrocarburos aisladas de suelos de las cuencas de los ríos Otún y La Vieja / Evaluation of hydrocarbon degrading bacteria diversity isolated from soils of Otún and La Vieja river basins

    OpenAIRE

    Yanine Suárez, Habib Fernando

    2010-01-01

    Se evaluó el efecto del uso del suelo, sobre la densidad y diversidad de bacterias degradadoras de hidrocarburos (HC). Se seleccionaron los usos: bosque, pastizal y cafetal en la cuenca del río La Vieja (Valle del Cauca y Quindío), y bosque, cebollar y plantación forestal en la cuenca del río Otún (Risaralda) y se realizaron dos eventos de muestreo. La densidad se evaluó mediante la técnica de NMP en medio Bushnell-Hass, suplementado con diesel y usando XTT como indicador de actividad. Las ba...

  3. Optimización de un medio de cultivo para la producción de biomasa de la cepa Pseudomonas putida UA 44 aislada del suelo bananero de Uraba –Antioquia

    OpenAIRE

    Becerra Mejía, Camilo Andrés

    2007-01-01

    En el presente trabajo se diseñó y optimizó un medio de cultivo químicamente definido para la bacteria Pseudomonas putida UA44 con potencial PGPR aislada del suelo de la zona bananera de Uraba por Ramirez (2004). Los resultados obtenidos en el medio químicamente definido (MD) se compararon con los hallados en un medio de cultivo semicomplejo (TSB: Triptic Soy Broth por sus siglas en Ingles).

  4. Polihidroxialcanoatos de cepas de Azospirillum spp. aisladas de raíces de Lycopersicon esculentum Mill. “tomate” y Oryza sativa L. “arroz” en Lambayeque

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    Katty Baca

    2010-01-01

    Full Text Available En este trabajo se determinó la concentración de polihidroxialcanoatos (PH As de cepas de Azospirillum aisladas de raíces de Lycopersicon esculentum Mill. “tomate” y Oryza sativa L. “arroz”, como una alternativa ante la acumulación de plásticos derivados del petróleo. R aíces previamente desinfectadas se sembraron en medio Nfb se misólido, donde las bacterias fijadoras de nitrógeno se reconocieron por una película blanquecina bajo la superficie y el viraje del indicador al azul. El género Azospirillum se identificó en medio rojo de Congo, obteniéndose 96 cepas de A. lipoferum y A. brasilense en tomate y arroz. Se realizó una fermentación discontinua con caldo Azotobacter modificado, alimentando con una solución saturada de ácido málico cada 12 horas y se realizaron tinciones con Sudán Negro B. Se seleccionaron las cepas con mayor nú mero de gránulos de PHAs (en tomate , 18 de A. lipoferum y 2 de A. brasilense y en arroz, 10 de A. lipoferum y 10 de A. brasilense y se cuantificó la biomasa y PHAs. La concentración de PHAs alcanzó 0 . 661 gL - 1 en A. lipoferum KM(T - 73 y 0 . 738 gL - 1 en A. br asilense KM(T - 19. Las cepas de A. lipoferum y A. brasilense aisladas de tomate alcanzaron una mayor concentración de biomasa y PHAs frente a las cepas aisladas de arroz.

  5. Effect of adding mucilage from Opuntia ficus-indica and Opuntia atropes to raw milk on mesophilic aerobic bacteria and total coliforms

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    R. Ortiz-Rodríguez

    2016-01-01

    Full Text Available Se evaluó la adición de mucílago líquido y deshidratado de Opuntia ficus-indica y Opuntia atropes a la leche cruda sobre el crecimiento de bacterias mesófilas aerobias y coliformes totales. Las muestras de leche cruda de vacas Holstein de un sistema de producción familiar se adicionaron con mucílago líquido o deshidratado de O. ficus-indica u O. atropes en concentraciones de 0.5, 1.0 y 2.0%. En las muestras se midió el crecimiento de bacterias mesófilas aerobias y coliformes totales. Los resultados se analizaron mediante los modelos de efectos fijos y las comparaciones entre grupos se realizaron por el método de medias de mínimo cuadrados. En general, las cuentas bacterianas para mesófilas aerobias y coliformes totales disminuyeron (P < 0,05 cuando se adicionó mucilago a la leche cruda al 0,5%, independientemente de la especie o de la forma física (deshidratado o líquido. Se observó disminución de cuentas bacterias para mesófilas aerobias (P < 0.05 cuando se adicionó mucílago deshidratado de O. ficus indica (Log10 2.6 UFC mL-1 y O. atropes (Log10 2,7 UFC mL-1 en concentración de 0.5%, respectivamente. Mientras que el grupo Control (leche cruda sin adición de mucílago contenía Log10 3.6 UFC mL-1 de mesófilas aerobias. La mejor respuesta para coliformes totales se observó con el mucílago deshidratado de O. ficus-indica (Log10 3.0 UFC mL-1 y mucílago líquido de O. atropes (Log10 2,7 UFC mL1, ambos adicionados al 1%. El mucílago deshidratado o líquido de O. ficus-indica y O. atropes reducen el contenido microbiano de la leche cruda.

  6. PRUEBAS DE SENSIBILIDAD FRENTE A AGENTES ANTIMICROBIANOS EN CEPAS DE Brachyspira pilosicoli AISLADAS A PARTIR DE PONEDORAS COMERCIALES EN COLOMBIA

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    DM Álvarez

    2009-01-01

    Full Text Available Las espiroquetas intestinales del género Brachyspira ocasionan enfermedades importantes en porcinos y aves. Se ha evidenciado un problema de incremento en la presentación de cepas resistentes a los antimicrobianos utilizados normalmente para tratar las espiroquetosis intestinales en porcinos, y esto podría ser aplicable a los aislamientos de aves. Hay muy pocos reportes de sensibilidad antimicrobiana in vitro de cepas de Brachyspira spp. aisladas en aves. En este estudio se evaluó la sensibilidad de doce aislamientos de Brachyspira pilosicoli obtenidos de granjas de ponedoras comerciales a los agentes antimicrobianos tiamulina, tilosina y lincomicina, y se estableció la concentración mínima inhibitoria (CMImediante la técnica de dilución en agar. Todas las bacterias analizadas fueron sensibles a tiamulina (CMI ≤0,1 μg/ml y lincomicina (CMI 1 μg/ml y resistentes a tilosina (CMI 5 μg/ml.

  7. Depuración aerobia de los efluentes resultantes del proceso de biometanización del alpechín

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    Borja Padilla, R.

    1992-02-01

    Full Text Available A study of aerobic treatment in batch regime of the effluents produced in the olive mill wastewater biomethanation process was carried out. An 83% of effluents organic substances was removal after the third day of fermentation. The substrate removal rate follows a zero-order kinetic for high concentrations, and a first-order kinetic for low organic matter concentration, during the last days of fermentation. The kinetic parameters (qmáx and K were obtained from Michaelis- Menten model.

    Se ha efectuado un estudio del proceso de depuración aerobia, en régimen discontinuo, de los efluentes procedentes del proceso de depuración anaerobia o biometanización del alpechín. Se comprueba que el 83% de la materia orgánica presente en este efluente se elimina a partir del tercer día de fermentación. La eliminación de sustrato sigue una cinética de orden cero para altas concentraciones del mismo y una cinética de primer orden para bajas concentraciones de materia orgánica, es decir, durante los últimos días de fermentación. Se aplica el modelo de Michaelis-Menten de eliminación de sustrato para la obtención de los parámetros cinéticos qmáx y Ks que rigen este proceso.

  8. Estado de Salud infantil en las comunidades indígenas, afrocolombianas y aisladas en Colombia.

    OpenAIRE

    Francisco Nuñez L.; Ignacio M. Zarante; Jaime E. Bernal V.

    2002-01-01

    Se estima que Sur América en la época precolombina tenía entre 7 y 39 millones de habitantes(1). Como consecuencia del descubrimiento y la conquista de América la población indígena fue diezmada en gran proporción; entre las causas adicionales que explican esta disminución en la población, se encuentran múltiples patologías de diverso origen. A pesar de la reducción importante de las poblaciones aisladas Colombia cuenta hoy con una amplia diversidad étnica que motivó al Instituto de ...

  9. Efectos de la hindarina sobre las aurículas aisladas

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    Roberto Luis Rojas Martínez

    1997-12-01

    Full Text Available Se presentan los efectos de la hindarina y de la clorpromacina sobre la amplitud y la frecuencia de las contracciones espontáneas de las aurículas aisladas de rata. La hindarina produjo bradicardia moderada y aumento discreto de la amplitud de las contracciones en forma dosis-dependiente, en tanto que la clorpromacina deprimió más intensamente tanto la frecuencia como la amplitud de dichas contracciones. Se descartó una acción colinérgica o beta-bloqueadora en la producción de la bradicardia por la hindarina. Se descartó también una acción cardiotónica de la hindarina en las aurículas aisladas de cobayo deprimidas por solución hipocálcica o por hipoxia. Se sugiere su estudio como antiarrítmico.The effects of hindarine and of chlorpromazine on the amplitude and frequency of the spontaneous contractions of rats' isolated atria are presented. Hindarine produced a moderate bradycardia and a discreet increase of the contractions in a dosage-dependent way. Chlorpromazine caused a greater depression of the frequency and amplitude of these contractions. The cholinergic or beta-blocker action was discarded in the production of bradycardia brought about by hindarine. It was also eliminated a cadiotonic action of hindarine in the isolated atria of guinea pig depressed by hypocalcic solution or by hipoxia. It is suggested its study as an antiarrhythmic.

  10. Prueba de sensibilidad antimicrobiana de cepas de Salmonella grupo D (móviles e inmóviles aisladas de ponedoras comerciales en Colombia

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    J. Jaime

    2010-12-01

    Full Text Available Las infecciones originadas por bacterias del género Salmonella son una de las principalescausas de pérdidas económicas en la industria avícola, se caracterizan generalmentepor la presentación de cuadros diarreicos y septicémicos que llevan a las aves a unamarcada disminución en la producción y a la muerte. En Colombia, debido al efectonegativo que produce Salmonella spp. en las aves, y con el objetivo de poder controlarla enfermedad, se utiliza una gran variedad de productos antimicrobianos, de loscuales no se posee suficiente información acerca de su comportamiento en cuanto asensibilidad y resistencia frente a las cepas de Salmonella spp. de campo. El objetivo deeste estudio fue determinar la respuesta de 20 cepas de Salmonella grupo D (móviles einmóviles aisladas de aves ponedoras comerciales en Colombia frente a diferentes antimicrobianos.Para su aislamiento y tipificación se utilizaron técnicas microbiológicasconvencionales, pruebas bioquímicas, serológicas y pruebas de susceptibilidad a losantibióticos por difusión en agar. Los resultados revelaron una resistencia total hacia laestreptomicina, seguida de altas resistencias para tetraciclina y florfenicol, y una menorresistencia a productos como fosfomicina y cloramfenicol.

  11. Prueba de sensibilidad antimicrobiana de cepas de salmonella grupo D (móviles e inmóviles aisladas de ponedoras comerciales en Colombia

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    J. Mantilla

    2010-01-01

    Full Text Available Las infecciones originadas por bacterias del género Salmonella son una de las principales causas de pérdidas económicas en la industria avícola, se caracterizan generalmente por la presentación de cuadros diarreicos y septicémicos que llevan a las aves a una marcada disminución en la producción y a la muerte. En Colombia, debido al efecto negativo que produce Salmonella spp. en las aves, y con el objetivo de poder controlar la enfermedad, se utiliza una gran variedad de productos antimicrobianos, de los cuales no se posee suficiente información acerca de su comportamiento en cuanto a sensibilidad y resistencia frente a las cepas de Salmonella spp. de campo. El objetivo de este estudio fue determinar la respuesta de 20 cepas de Salmonellas grupo D (móviles e inmóviles aisladas de aves ponedoras comerciales en Colombia frente a diferentes antimicrobianos. Para su aislamiento y tipificación se utilizaron técnicas microbiológicas convencionales, pruebas bioquímicas, serológicas y pruebas de susceptibilidad a los antibióticos por difusión en agar. Los resultados revelaron una resistencia total hacia la estreptomicina, seguida de altas resistencias para tetraciclina y florfenicol, y una menor resistencia a productos como fosfomicina y cloramfenicol.

  12. Betalactamasas de espectro extendido tipo TEM y CTX-M en Klebsiella spp y Escherichia coli aisladas de superficies de ambientes hospitalarios

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    Marco Rivera-Jacinto

    Full Text Available El objetivo del estudio fue determinar el genotipo BLEE de 15 cepas de enterobacterias resistentes a betalactámicos, aisladas de superficies inanimadas y caracterizadas fenotípicamente como productoras de betalactamasas de espectro extendido. Previa evaluación y tamizaje de las cepas bacterianas, se hizo un PCR para amplificar fragmentos de 1078 pb y 544 pb correspondientes a BLEE tipo TEM y CTX-M. Once cepas presentaron ambos fragmentos a la vez y tres presentaron solamente blaCTX-M. En conclusión, se demostró la presencia de genes BLEE en cultivos de origen ambiental, algunos de los cuales podrían pertenecer a más de un tipo; esta información podría servir de base para implementar medidas de prevención que eviten la trasmisión de bacterias multirresistentes desde superficies inanimadas a los pacientes, principalmente en áreas hospitalarias críticas

  13. Instalación eléctrica de una vivienda unifamiliar aislada mediante suministro de energías renovables

    OpenAIRE

    LOZANO VALLADOLID, FERNANDO

    2015-01-01

    [ES] Instalación eléctrica con grado de electrificación elevada de una vivienda unifamiliar aislada mediante suministro de energías renovables (solar, eólica, geotérmicas). Lozano Valladolid, F. (2015). Instalación eléctrica de una vivienda unifamiliar aislada mediante suministro de energías renovables. http://hdl.handle.net/10251/58751. TFGM

  14. Proyecto básico y de ejecución de vivienda unifamiliar aislada con piscina

    OpenAIRE

    Zapata Sánchez, Miguel

    2012-01-01

    El objetivo del presente proyecto es servir de soporte técnico y administrativo a la obra que en él se describe: Vivienda unifamiliar aislada, compuesta de dos plantas (baja y primera), con 6 dormitorios y 4 cuartos de baño, adaptada para habitantes minusválidos. Incluye piscina cubierta en el exterior de la vivienda Escuela de Arquitectura e Ingeniería de Edificación Universidad Politécnica de Cartagena

  15. Proyecto de rehabilitación y acondicionamiento de vivienda unifamiliar aislada en Tamarite de Litera (Huesca)

    OpenAIRE

    Solano Ballester, Ma. Teresa

    2009-01-01

    Vivienda unifamiliar aislada construida en suelo urbano, situada en el casco histórico del término municipal de Tamarite de Litera, provincia de Huesca (Aragón) en la calle San Antonio Alta Nº 1. Según información de catastro, su construcción data del año 1888, con posteriores reformas. Después de una valoración del lugar, del entorno y las posibilidades de la edificación, se ha optado por un desarrollo de un proyecto que tiene como propósito la rehabilitación y acondicionamiento de dicha viv...

  16. Uso de dispositivos móviles en zonas rurales aisladas abastecidas con energía solar fotovoltaica

    OpenAIRE

    Rocabado Moreno, Sergio Hernán; Díaz, Francisco Javier; Cadena, Carlos

    2015-01-01

    En el presente trabajo se propone el uso de dispositivos móviles, con recarga basada en energía solar fotovoltaica, para acceder a información digital desde zonas rurales que se encuentren fuera del alcance de los centros de distribución de energía. Se realizaron mediciones de la potencia utilizada por un dispositivo móvil ubicado en una zona rural aislada, inicialmente se determinó el consumo de energía del celular sin carga de trabajo (e0), luego se midió el consumo adicional de energía (e1...

  17. Perfiles de resistencia a antibióticos y metales pesados en Pseudomonas aeruginosa potencialmente patógenas aisladas de agua de uso agrícola

    Directory of Open Access Journals (Sweden)

    Oscar G. Gutiérrez Cárdenas

    2017-01-01

    Full Text Available El 70% de l agua a nivel mundial se destina principalmente para las actividades agrícolas. Sin embargo, debido al crecimiento descontrolado de los asentamientos urbanos se ha acentuado la escasez y contaminación de los cuerpos de agua superficiales, de tal forma que cada vez este líquido de buena calidad es más escaso para la agricultura. Uno de los pri n cipa les contaminantes son las bacterias potencialmente patógenas resistentes a los antibiót i cos. Pseudomonas aeruginosa es una bacteria que se encuentra normalmente en el agua y suelo, es patógeno de animales y plantas. Esta bacteria se ha considerado un fenóm eno de resistencia debido a la diversidad de mecanismos que posee, por lo cual representa un rie s go potencial para la p o blación. Método : Se colectaron muestras de agua de uso agrícola, a partir de las cuales se aislaron e identificaron a nivel bioquímico y molecular P. aeruginosa . En estas bacterias se determinó la distribución de 6 genes de virulencia por PCR. Mediante ensayos de difusión en disco y m i crodilución se analizó la resistencia a 20 antibióticos. Además mediante ensayos de microd i lución se dete rminó la resistencia a metales pesados. Resultados : Se identificaron a nivel bioquímico y molecular 46 aislados de P. aeruginosa, éstas son potencialmente patógenas ya que en ellas se detectó la presencia de los genes de virule n cia algD y toxA (100%, las B (97.8%, plcH (95.6%, plcN (91.3% y exoS (89.1%. Dichas bacterias presentaron altos índices de resistencia a ampicilina, ceftriaxona, cloranfen i col, cefalotina, cefotaxima, nitrofurantoína, kanamicina , estreptomicina y tetraciclina. De igual forma fue ron muy susceptibles a ceftazidima, gentamicina, imipenem, ticarcilina, a z treonam, levofloxacina, netilmicina y carbenicilina. Todas las bacterias fueron multirresiste n tes ya que toleraron entre 8 y 11 antibióticos. De acuerdo a los patrones de resistencia obse r vados, las bacterias se

  18. Especies de Malassezia aisladas de pacientes con lesiones dermatológicas

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    Sandra Rincón

    2005-06-01

    Full Text Available Introducción. Las levaduras del género Malassezia forman parte de la flora normal de la piel y se asocian con varios tipos de lesiones dermatológicas. Desde 1996, la descripción de nuevas especies dentro de este género planteó numerosos interrogantes sobre su epidemiología y patogenicidad. Objetivo. El fin de este trabajo fue encontrar la frecuencia de las diferentes especies de Malassezia en individuos con pitiriasis versicolor, dermatitis atópica, dermatitis seborreica, dermatitis seborreica en pacientes positivos para VIH, y en individuos sin lesiones a partir de tres zonas corporales (cabeza, tórax, extremidades inferiores y superiores. Materiales y métodos. Se identificaron 154 aislamientos de especies de Malassezia de 112 individuos: 39 con dermatitis seborreica de los cuales 20 eran positivos para VIH, 18 con pitiriasis versicolor, 18 con dermatitis atópica y 37 individuos sin lesión dermatológica (controles. Las escamas de piel de los pacientes se observaron microscópicamente y las muestras de pacientes y controles se cultivaron en agar Dixon modificado. Posteriormente, se observaron las colonias y se identificaron según sus características macroscópicas, microscópicas y fisiológicas. Resultados. Las especies más frecuentemente aisladas en el total de los grupos estudiados fueron: Malassezia globosa (37,5%, M. sympodialis (31,3% y M. furfur (31,3%. M. globosa predominó en los aislamientos de pacientes con pitiriasis versicolor (67% y en pacientes positivos para VIH con dermatitis seborreica (85%. En pacientes con dermatitis atópica y dermatitis seborreica sin diagnóstico de VIH, se aislaron M. furfur y M. restricta en el 72% y el 26% de los casos, respectivamente. Conclusiones. Las diferentes especies de Malassezia pueden aislarse de pacientes con lesiones dermatológicas o sin ellas. Además, la frecuencia de especies en la población muestreada difiere de lo reportado en otras zonas geográficas. Se destaca la

  19. Incidencia y fármaco-resistencia de cepas de Staphylococcus spp aisladas de exudados conjuntivales Incidence and drug-resistance of Staphylococcus spp strains isolated from conjunctival swabs

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    Andrés Noya Cabaña

    2010-01-01

    Full Text Available OBJETIVO: Determinar la incidencia de cepas del género Staphylococcus aisladas de exudados conjuntivales y analizar su resistencia frente a diferentes antimicrobianos. MÉTODOS: Se realizó un estudio observacional descriptivo retrospectivo en el que se revisaron 3554 exudados conjuntivales a pacientes que acudieron en el período comprendido entre enero de 2002 a diciembre de 2003 y desde enero de 2005 hasta diciembre de 2007 al Instituto Cubano de Oftalmología «Ramón Pando Ferrer» por presentar un diagnóstico de infección ocular externa. RESULTADOS: Se aislaron 874 cepas de Staphylococcus aureus para un 47,5 % y 965 cepas de Staphylococcus spp. coagulasa negativa con prueba de patogenicidad positiva para un 52,4 %. En 69 de esos exudados los cultivos presentaron etiología mixta con dos bacterias diferentes, para el 3,7 %. Se determinaron los porcentajes de resistencia a las cepas aisladas pertenecientes al género Staphylococcus. CONCLUSIONES: Se encontró una alta incidencia de las especies del género Staphylococcus en las infecciones oculares, así como se pudo apreciar que la menor fármaco-resistencia para Staphylococcus aureus y Staphylococcus spp. coagulasa negativa correspondieron a los antimicrobianos ciprofloxacina y amikacina. La mayor fármaco-resistencia de las cepas de Staphylococcus aureus correspondió a eritromicina y tetraciclina y en Staphylococcus spp coagulasa negativa fue frente a la tetraciclina.OBJECTIVE: To determine the incidence of Staphylococcus strains isolated from conjunctival swaps and their resistance to several antimicrobial agents. METHODS: A retrospective, descriptive and observational study was performed to review 3554 conjunctival swabs from patients who went to "Ramón Pando Ferrer" Institute of Ophthalmology in the period from January 2002 to December 2009 due to a diagnosis of external ocular infection. RESULTS: From the total of conjunctival swabs, 874 Staphylococcus aureus strains (47.5 % and

  20. Caracterización molecular de serovariedades de Leptospira spp. aisladas de muestras de animales y agua en Colombia

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    Claudia M. Romero-Vivas

    2013-08-01

    Full Text Available Introducción. La leptospirosis es una infección bacteriana transmitida directa o indirectamente de animales a humanos, la cual puede resultar en una enfermedad hemorrágica grave, hepática o renal y pulmonar. Hay 20 especies de Leptospira conocidas y cientos de serovariedades, algunas de las cuales pertenecen a diferentes especies. Es esencial identificar las serovariedades patógenas y sus reservorios potenciales para enfocar estrategias de control. Objetivo. Caracterizar las serovariedades de Leptospira aisladas de muestras de roedores, perros, cerdos y agua en Colombia. Materiales y métodos. Las cepas de leptospiras aisladas fueron identificadas como patógenas usando la reacción en cadena de la polimerasa (PRC. Sus ADN y el ADN de Salmonella Braenderup H9812 (marcador de peso molecular fueron cortados con NotI y corridos en electroforesis de campo pulsado. Los patrones de la ECP se analizaron con base en los criterios de tipificación para cepas bacterianas y el coeficiente de Dice, cuando se compararon con 200 cepas aisladas en otras partes del mundo. Los perfiles de ADN con un coeficiente de Dice entre 73,7 % y 100 % se consideraron pertenecientes a la misma especie. Resultados. Todos los aislamientos fueron cepas patógenas y cinco se caracterizaron genéticamente. El aislamiento P275 (coeficiente de Dice: 84 % y el P282 (coeficiente de Dice: 95 % de cerdos, se relacionaron con Leptospira interrogans de serovariedad Pomona; el aislamiento de rata (I15 fue indistinguible de Leptospira interrogans de serovariedades Icterohaemorrhagiae o Copenhageni (coeficiente de Dice: 100 %, mientras que los aislamientos de perro (C67 y agua (A42 no se relacionaron (coeficiente de Dice <73,7 % con ninguna de las 200 cepas de referencia; las más cercanas fueron Leptospira noguchii de serovariedades Nicaragua (coeficiente de Dice: 63 % y Orleans (coeficiente de Dice: 60 %. Conclusiones. Esta fue la primera caracterización molecular de serotipos de

  1. Presencia de B-lactamasas de espectro extendido en enterobacterias aisladas de casos de infección nosocomial

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    Sergio Pavón Romero

    2011-01-01

    Full Text Available Las enterobacterias son los microorganismos etiologicos mas frecuentemente asociados a las infecciones nosocomiales (in, caracterizandose por su alta resistencia a los antibioticos B-lactamicos, mediada por la produccion de B-lactamasas de Espectro Extendido (blee. Su uso excesivo aumenta la seleccion de cepas multirresistentes, favoreciendo su propagacion e incremento de las complicaciones de casos de in. En algunos casos las cepas productoras de blee presentan resistencia adicional a aminoglucosidos, quinolonas, tetraciclinas y trimetoprim-sulfametoxazol, reduciendo las opciones terapeuticas de las in. Con la finalidad de conocer localmente la magnitud de este problema, se estudiaron 87 cepas de enterobacterias aisladas de casos de in, encontrandose que el 26.43% son productoras de blee y en este caso fenotipicamente multirresistentes.

  2. Neisseria meningitidis:contribución al transporte-conservación y caracterización de cepas aisladas en Cuba (1982-2002)

    OpenAIRE

    Martínez Motas, Isabel Florentina

    2005-01-01

    Con el objetivo de profundizar en los aspectos microbiológicos y epidemiológicos relacionados con las cepas de Neisseria meningitidis aisladas en Cuba durante 20 años (1982-2002), se realizó este trabajo. Se obtuvo un medio de cultivo útil para el transporte-conservación de cepas aisladas en Cuba y otros países. El Medio TC con líquido ascítico, mostró porcentajes de viabilidad aceptables durante un período de 6 meses y después de 12 años de almacenamiento a la temperatura de 20-25 0C, se re...

  3. Antimicrobial susceptibility test in Brachyspira pilosicoli strains isolated from commercial layers farms in Colombia PRUEBAS DE SENSIBILIDAD FRENTE A AGENTES ANTIMICROBIANOS EN CEPAS DE Brachyspira pilosicoli AISLADAS A PARTIR DE PONEDORAS COMERCIALES EN COLOMBIA

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    Figueroa Ramìrez Judith

    2009-04-01

    Full Text Available Intestinal Spirochaetes of the genus Brachyspira cause important diseases in swine and poultry. An increasing problem in the presentation of resistant strains to the antimicrobial drugs usually used to treat the intestinal spirochaetosis in swine has been evidenced and this could be applicable to the isolations from poultry. There are very few reports of in vitro antimicrobial susceptibility of Brachyspira spp. isolated from birds. In this study the antimicrobial susceptibility of twelve Brachyspira pilosicoli isolates obtain from commercial layers was evaluated against tiamulin, tylosin and lincomycin establishing the Minimum Inhibitory Concentration (MIC by agar dilution technique. All bacteria analyzed were sensitive to tiamulin (MIC ≤0,1μg/ml, and lincomycin (MIC 1μg/ml and resistant to tylosin (MIC 5μg/ml.Las espiroquetas intestinales del género Brachyspira ocasionan enfermedades importantes en porcinos y aves. Se ha evidenciado un problema de incremento en la presentación de cepas resistentes a los antimicrobianos utilizados normalmente para tratar las espiroquetosis intestinales en porcinos, y esto podría ser aplicable a los aislamientos de aves. Hay muy pocos reportes de sensibilidad antimicrobiana in vitro de cepas de Brachyspira spp. Aisladas en aves. En este estudio se evaluó la sensibilidad de doce aislamientos de Brachyspira pilosicoli obtenidos de granjas de ponedoras comerciales a los agentes antimicrobianos tiamulina, tilosina y lincomicina, y se estableció la concentración mínima inhibitoria (CMI mediante la técnica de dilución en agar. Todas las bacterias analizadas fueron sensibles a tiamulina (CMI ≤0,1 μg/ml y lincomicina (CMI 1 μg/ml y resistentes a tilosina (CMI 5 μg/ml.

  4. Determinación de la Variedad de Cepas de Cryptococcus Neoformans aisladas de pacientes con SIDA

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    C Canelo

    1999-01-01

    Full Text Available Cryptococcus neoformans tiene 2 variedades: neoformans y gattii. El primero afecta a pacientes inmunosuprimidos y la variedad gattii produce enfermedad en individuos aparentemente sanos originando compromiso neurológico. En nuestro país no se realizan pruebas bioquímicas diferenciales, por lo que este estudio permitió estandarizar un método de tipificación de las variedades en cepas de C. neoformans de origen clínico mantenidas en el Instituto Nacional de Salud del Perú (INS. Entre abril de 1997 y diciembre de 1998, el INS recibió 18 cepas de C. neoformans aisladas de pacientes con SIDA. La confirmación de las especies fue realizada según métodos convencionales: observación de levaduras encapsuladas, prueba de la urea, asimilación de carbohidratos y tolerancia a la temperatura. Adicionalmente se verificó la ausencia de la enzima nitrato reductasa y se realizó la prueba de la fenoloxidasa modificada. Las 18 cepas fueron tipificadas como variedad neoformans usando el agar CGB. No se encontró ninguna cepa de variedad gattii.

  5. Cirugía de mínimo acceso de la fibrilación auricular aislada

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    Aquilino Hurlé

    2008-10-01

    Full Text Available La fibrilación auricular es el trastorno del ritmo cardíaco más frecuente. Durante años, su tratamiento se vio limitado casi exclusivamente al control farmacológico de la frecuencia cardíaca y a la prevención de eventos tromboembólicos con fármacos anticoagulantes. Debido a los recientes avances en el campo de la electrofisiología cardíaca y al desarrollo tecnológico, el abordaje terapéutico de esta arritmia se contempla hoy en día desde una perspectiva mucho más intervencionista que antaño. Recientemente, técnicas de cirugía videoasistida de última generación han comenzado a ser aplicadas en el tratamiento de la fibrilación auricular aislada con dos modalidades de abordaje: la cirugía mediante miniincisiones (minitoracotomía y la cirugía toracoscópica propiamente dicha. En este artículo describiremos y comentaremos estas formas de tratamiento quirúrgico de la fibrilación auricular.

  6. Cepas nativas del bacterioneuston marino y su actividad inhibitoria de bacterias ictiopatógenas

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    Jorge León

    2014-06-01

    Full Text Available En la literatura científica, las bacterias marinas han sido consideradas con frecuencia como productores de sustancias antibacterianas. En este estudio, se investigó el potencial de actividad antibiótica in vitro de cepas nativas de bacterioneuston marino aisladas de las pozas intermareales de Montemar, Bahía de Valparaiso, Chile. Se aislaron 71 cepas neustónicas antagonistas a Staphylococcus aureus ATCC 11632. Veinticinco de ellas, productoras de sustancias fuertemente inhibitorias, fueron evaluadas por su antagonismo frente a una colección de 15 bacterias ictiopatógenas. Aplicando métodos clásicos para bacterias marinas, se caracterizaron fenotípicamente orientados a la identificación. Los resultados de antibiosis indican que la totalidad cle las ictiopatógenas en prueba son susceptibles a la actividad inhibitoria de las cepas neustónicas, siendo V anguillarum NCMB 2133, V ordalii 84/2559 y V tubiashii EX1 las más sensibles. Entre las cepas aisladas del neuston se identificaron miembros de los géneros Vibrio spp. (28%, Flavobacterium spp. (12%, Alteromonas-Marinomonas (12%, Pseudomonas spp (8% y Micrococcus spp, (4%. Nueve cepas (36% no fueron identificadas. Los resultados de actividades inhibitorias frente a ictiopatógenos sugieren que dichas cepas o sus productos pudieran ser útiles en actividades de cultivos intensivos de maricultura de peces, moluscos y crustáceos.

  7. Sensibilidad antibiótica de cepas de Haemophilus spp aisladas de pacientes pediátricos en un hospital general entre los años 2003 -2006.

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    Raúl Rodrigo Alarco Castro

    2008-04-01

    Full Text Available Objetivo: Determinar la sensibilidad antibiótica de cepas de Haemophilus spp aisladas de pacientes pediátricos en un hospital general entre los años 2003 y 2006. Materiales y métodos: Estudio descriptivo retrospectivo en el que se incluyeron cultivos positivos de Haemophilus spp. Se revisaron las historias clínicas de los pacientes de los cuales provenían los cultivos. Resultados: Se encontraron 37 cultivos positivos para Haemophilus spp, entre los cuales se encontró mayor sensibilidad a levofloxacino (100%, ampicilina/sulbactam (92%, carbapenems (95% y ciprofloxacino (85%. La sensibilidad a los antibióticos más usados contra esta bacteria fue menor: ampicilina (73%, ceftriaxona (77%, cloramfenicol (78% y azitromicina (62%. Se comparó la resistencia de las cepas que causaron neumonía y meningoencefalitis, encontrándose similar sensibilidad a lo ya presentado. En relación a los factores asociados a resistencia a antibióticos específicos no se encontró diferencias importantes por tratarse de grupos pequeños, pues de los 37 cultivos, sólo se encontraron 18 historias clínicas. Conclusión: La resistencia a antibióticos de primera línea (ampicilina y cloramfenicol es baja. Ampicilina/sulbactam es el antibiótico que presentó menor resistencia. Se necesitan estudios más amplios para determinar factores asociados a resistencia. (Rev Med Hered 2008;19

  8. Determinación de factores de virulencia en cepas de Aeromonas spp., aisladas a partir de pescado

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    William Suárez Q.

    2012-04-01

    Full Text Available Objetivo. Investigar la incidencia de cinco marcadores fenotípicos de virulencia en cepas de Aeromonas aisladas a partir de muestras de pescado expendido en Pamplona, Colombia. Materiales y métodos. Se utilizaron 47 cepas identificadas previamente. Se evaluaron: actividad hemolítica en agar sangre, suplementado con 5% de eritrocitos de cordero y agar sangre suplementado con 5% eritrocitos de sangre humana; actividad proteolítica en agar Mueller-Hinton suplementado al 10% (p/v con leche descremada, actividad lipolítica en agar tributirina; actividad desoxirribonucleasas en agar DNAsa. Resultados. Se encontró que las cepas de A. hydrophila, A. veronii GH 8, A. jandaei, A. veronii GH 10 y A. eucrenophila, demostraron capacidad hemolítica, proteolítica, lipolítica y nucleasa. Todas las cepas de A. popoffii fueron β-hemolíticas en agar sangre humana, proteolíticas y con actividad DNAsa. Las cepas de A. caviae, coincidieron en ser hemolíticas y lipolitícas, mientras que la cepa de A. schubertii, manifestó la presencia de actividad hemolítica y DNAsa. Conclusiones. La frecuencia de los factores de virulencia en las cepas estudiadas fue: el 87% demostraron producción de nucleasas; el 83% fueron β-hemolíticas sobre eritrocitos humanos; el 68% expresaron producción de lipasas, el 63% fueron proteolíticas y el 53% resultaron ser hemolíticas sobre eritrocitos de cordero, indicando estos datos el posible potencial patógeno de las cepas. Estos resultados mostraron que el pescado comercializado en Pamplona, puede ser una fuente importante de especies de Aeromonas que expresan factores asociados a la virulencia para el hombre.

  9. Determinación del potencial promotor del crecimiento vegetal de las enterobacterias aisladas de la rizósfera del cultivo de maíz (Zea mays L.

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    Luis H. León Mendoza

    2014-01-01

    Full Text Available El maíz amarillo duro es el tercer cultivoen importancia en el Perú y forma parte de la cadena maíz-avicultura-porcicultura, de impacto significativo en la actividad económica y social nacional, sin embargo, enel 2011, solo el 40%del maíz ofertado correspondió a la producción nacional. En busca de alternativas paradisminuir el uso de fertilizantes químicos se realizan investigaciones con denominadas rizobacteriaspromotoras del crecimiento vegetal. Las bacterias se aislaron de la rizósfera de maíz procedentes de camposagrícolas de los distritos de Monsefú y Reque, Región Lambayeque. Se realizó una dilución en solución salinaesterilizada: 0,87%NaCl, p/v y se sembró en agar Mac Conkey, incubando a 30°Cpor 48 horas. Se obtuvieron269 cultivos puros de bacterias, se investigósu reacción bioquímica en agar Hierro Triple Azúcar, agar HierroLisina,agar Citrato de Simons, caldo peptonado, caldo rojo de metilo Voges-Proskauer y caldo nitrato,identificándose 66%como enterobacterias de los génerosPantoea(49%,Klebsiella(17%,Kluyvera(16%,Serratia(11%,Citrobacter(4% yHafnia(3%. Con las enterobacterias nativas se cuantificó hasta 31,67ppm de nitrógeno fijado como amonio; 54,25 ppm de ácido indol acético y 4,78 ppm de fósforo solubilizado,así como también se determinó actividad proteolítica, quitinolítica y antagónica aFusarium verticillioides. El16%de enterobacterias nativas no afectó la emergencia de maíz amarillo duro hibrido simple AGRI-144, el77%la afectópositivamente y el 7%la afectó negativamente. A su vez, ninguna bacteria afectó lasobrevivencia.Se demostró el potencial promotor del crecimiento vegetal de las enterobacterias aisladas decampos de cultivos de la Región de Lambayeque.

  10. Identificación y caracterización de especies de Neosartorya aisladas de frutillas (Fragaria spp.) frescas y tratadas térmicamente

    OpenAIRE

    Laura Frisón; Silvina Sobrero; Juan De Jesús; María de Basílico; Juan Basílico

    2012-01-01

    El género Aspergillus es uno de los géneros fúngicos más estudiados y de gran impacto a nivel industrial. La sección Fumigati incluye unas pocas especies anamorfas del género Aspergillus. Las especies que son teleomorfas se encuentran dentro del género Neosartorya. Este es un moho resistente al calor que causan problemas en las industrias alimentarias o enfermedades en los seres humanos. Sus ascosporas han sido aisladas a partir de frutas, pulpas y jugos, ya que pueden sobrevivir a los tratam...

  11. Portadores de Neisseria meningitidis, caracterización de las cepas aisladas y respuesta inmune basal a VA-MENGOC-BC

    OpenAIRE

    María J. Valdés; Isabel Martínez; Gustavo Sierra; María A. Camaraza; Iván Cuevas; Mayelin Mirabal; Pedro Rodríguez; Yadira Fuentes; Graciela Bolaños; Isabel Villasusa

    2008-01-01

    Con el propósito de conocer la prevalencia de portadores de Neisseria meningitidis en un grupo de adolescentes, los marcadores epidemiológicos de las cepas aisladas, así como los factores de riesgo asociados con el estado de portador y la respuesta inmune basal a VA-MENGOC-BC , se realizó un estudio transversal descriptivo de portadores en 189 estudiantes de 12-19 años de un politécnico de Ciego de Ávila, siguiendo las Normas Bioéticas establecidas. A los estudiantes se les realizó un exudado...

  12. ESTUDIO DE SENSIBILIDAD ANTIMICROBIANA DE 183 CEPAS DE STREPTOCOCCUS AGALACTIAE AISLADAS EN REGION VAGINO-PERINEAL DE EMBARAZADAS EN EL TERCER TRIMESTRE

    OpenAIRE

    Belmar J.,Cristián; Abarzúa C.,Fernando; Beker V.,Jorge; Guzmán,Ana María; García C.,Patricia; Oyarzún E.,Enrique

    2002-01-01

    fluctúa entre 1 y 3 por 1000 recién nacidos vivos. Se han entregado pautas dirigidas a reducir las tasas de sepsis precoz con la administración de antibióticos intraparto. Se ha propuesto como antibiótico de primera elección la Penicilina o Ampicilina, y Clindamicina para pacientes alérgicos a las primeras, pero también se ha planteado el uso de Eritromicina o Cefazolina. Se estudia la sensibilidad a estas drogas, en 183 cepas de Streptococcus Grupo B, aisladas en 917 embarazadas, al final de...

  13. Empleo de la ultrafiltración extracorpórea aislada para el tratamiento de la insuficiencia cardiaca descompensada: dificultades técnicas y evolución clínica

    OpenAIRE

    José Luis Cobo Sánchez; Magdalena Gándara Revuelta; Raquel Pelayo Alonso; Araceli Sáenz de Buruaga Perea; María Yolanda Vicente Jiménez; Marina Rojo Tordable; Carmen Higuera Roldán; Violeta Olalla Antolín

    2013-01-01

    La ultrafiltración extracorpórea aislada se ha revelado como una posible estrategia terapéutica para pacientes con insuficiencia cardíaca descompensada resistente a diuréticos. Nuestro objetivo fue evaluar la evolución clínica a corto-medio plazo de los pacientes sometidos a ultrafiltración extracorpórea aislada y las incidencias técnicas/clínicas. Material y método: Estudio descriptivo transversal prospectivo en pacientes con insuficiencia cardíaca en estadio III-IV de la New York Heart Asso...

  14. Efectos de la proteína de soja aislada sobre la hipertensión y el alterado metabolismo de la glucosa en musculo cardíaco de ratas dislipemicas insulino resistentes.

    OpenAIRE

    Oliva, María E.; Chicco, Adriana; Lombardo, Yolanda B

    2017-01-01

    El objetivo del trabajo fue analizar los efectos de la administración de proteína de soja aislada, sobre la hipertensión y alteraciones del metabolismo de la glucosa presentes en el músculo cardíaco de ratas dislipémicas insulino resistentes, inducidas por una ingesta crónica de una dieta rica en sacarosa (DRS). Ratas machos Wistar recibieron durante 4 meses DRS. Finalizado este período, la mitad de los animales continuó con la DRS y en la otra mitad la proteína de soja aislada sustituyó a la...

  15. Degradación de Fenantreno por bacterias del género Burkholderia y Rhizobium aisladas de nódulos de mimosas

    OpenAIRE

    Arnoldo Wong-Villarreal; Erick Santiago-Mendez; Emanuel Hernández Núñez; Gustavo Yáñez-Ocampo; Germán Giácoman Vallejos; Avel González Sánchez; Sandra I. Ramírez González; Saúl Espinosa-Zaragoza; Orlando López-Báez

    2017-01-01

    El presente trabajo tuvo como objetivo identificar y evaluar la capacidad de degradación de microorganismos aislados de nódulos de mimosas, que puedan ser utilizados en procesos de biorremediación de suelos contaminados con fenantreno . Método . Se realizó el aislamiento de 122 cepas bacterianas de nódulos de mimosas; fueron crecidas en el medio de cultivo Maconkey para descartar enterobacterias. L as cepas bacterianas que dieron resultado n...

  16. Degradación de Fenantreno por bacterias del género Burkholderia y Rhizobium aisladas de nódulos de mimosas

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    Arnoldo Wong-Villarreal

    2017-01-01

    Full Text Available El presente trabajo tuvo como objetivo identificar y evaluar la capacidad de degradación de microorganismos aislados de nódulos de mimosas, que puedan ser utilizados en procesos de biorremediación de suelos contaminados con fenantreno . Método . Se realizó el aislamiento de 122 cepas bacterianas de nódulos de mimosas; fueron crecidas en el medio de cultivo Maconkey para descartar enterobacterias. L as cepas bacterianas que dieron resultado negativo a esta prueba, fueron inoculadas en el medio de cultivo que contenía como úni ca fuente de carbono fenantreno; tres aislados tuvieron la capacidad de crecer en este medio. Las tres cepas fueron identificadas por secuencia del gen 1 6s ribosomal, se evaluó su capacidad de crecimiento en presencia de fenantreno mediante curvas de crecimiento microbiano; la capacidad para degradar fenantreno de las tres cepas fue cuantificada por cromatografía de gases acoplado a masas. Resultados . La s secuencias obtenidas del gen 16s ribosomal tienen relación genética con las especies de Burkholderia phenoliruptrix , Burkholderia phymatum y Rhizobium paknamense. El crecimiento microbiano de las tres cepas, suministradas con fenantreno, tuvieron un comp ortamiento similar al control , el cual contenía succinato como fuente de carbono. La cepa de Burkholderia sp. BB26 degradó 78.5 % , Burkholderia sp. BB24 68.5 % y Rhizobium sp. BY8 99%. Discusión . Los resultados de degradación de fenantreno por las cepas de Burkholderia sp. BB26 , Burkholderia sp. BB24 y Rhizobium sp. BY8 sugieren que las tres cepas tienen p otencial para utilizarse en procesos de biorremediación de suelos contaminados con fenantreno.

  17. Magnetic Bacteria.

    Science.gov (United States)

    Nelson, Jane Bray; Nelson, Jim

    1992-01-01

    Describes the history of Richard Blakemore's discovery of magnetotaxic organisms. Discusses possible reasons why the magnetic response in bacteria developed. Proposes research experiments integrating biology and physics in which students investigate problems using cultures of magnetotaxic organisms. (MDH)

  18. Big bacteria

    DEFF Research Database (Denmark)

    Schulz, HN; Jørgensen, BB

    2001-01-01

    A small number of prokaryotic species have a unique physiology or ecology related to their development of unusually large size. The biomass of bacteria varies over more than 10 orders of magnitude, from the 0.2 mum wide nanobacteria to the largest cells of the colorless sulfur bacteria......, Thiomargarita namibiensis, with a diameter of 750 mum. All bacteria, including those that swim around in the environment, obtain their food molecules by molecular diffusion. Only the fastest and largest swimmers known, Thiovulum majus, are able to significantly increase their food supply by motility...... and by actively creating an advective flow through the entire population. Diffusion limitation generally restricts the maximal size of prokaryotic cells and provides a selective advantage for mum-sized cells at the normally low substrate concentrations in the environment. The largest heterotrophic bacteria...

  19. Big bacteria

    DEFF Research Database (Denmark)

    Schulz, HN; Jørgensen, BB

    2001-01-01

    A small number of prokaryotic species have a unique physiology or ecology related to their development of unusually large size. The biomass of bacteria varies over more than 10 orders of magnitude, from the 0.2 mum wide nanobacteria to the largest cells of the colorless sulfur bacteria...... and by actively creating an advective flow through the entire population. Diffusion limitation generally restricts the maximal size of prokaryotic cells and provides a selective advantage for mum-sized cells at the normally low substrate concentrations in the environment. The largest heterotrophic bacteria......, the 80 x 600 mum large Epulopiscium sp. from the gut of tropical fish, are presumably living in a very nutrient-rich medium. Many large bacteria contain numerous inclusions in the cells that reduce the volume of active cytoplasm. The most striking examples of competitive advantage from large cell size...

  20. Carotenogénesis de cinco cepas del alga Dunaliella sp. (Chlorophyceae aisladas de lagunas hipersalinas de Venezuela

    Directory of Open Access Journals (Sweden)

    Miguel Guevara

    2005-09-01

    Full Text Available Se realizaron cultivos discontinuos (medio Algal con 0.5 mM de NaNO3 y 27% de NaCl de cinco cepas de Dunaliella sp., aisladas de diferentes lagunas hipersalinas de Venezuela (Araya, Coche, Peonía, Cumaraguas y Boca Chica y una cepa de referencia (Dunaliella salina LB1644. Los bioensayos se mantuvieron a 25 ± 1 °C con aireación constante, fotoperiodo 12:12 y dos intensidades luminosas (195 y 390 µE.m-2.s-1 durante 30 días. El crecimiento celular se determinó diariamente mediante conteo celular en cámara de Neubaüer. La clorofila a y los carotenoides totales se analizaron al final del ensayo. Las mayores densidades celulares correspondieron a los ensayos de menor intensidad luminosa. La cepa que alcanzó la mayor densidad celular fue la aislada de Boca Chica (8 x10(6 y 2.5 x10(6 cel.ml-1 a 195 y 390 µE.m-2.s-1, respectivamente. El incremento de la intensidad luminosa en los cultivos produjo una disminución significativa de las tasas de crecimiento en todas las cepas. Los carotenoides totales por volumen fueron mayores a 390 µE.m-2 .s-1; siendo las cepas de referencia LB1644, Coche y Araya las que produjeron mayor cantidad (38.4; 32.8 y 21.0 µg.ml-1, respectivamente. El contenido de carotenoides totales por célula en los dos tratamientos fue significativamente diferente, obteniéndose la mayor concentración a 390 µE.m-2.s-1. Las cepas LB1644 y Coche fueron las que produjeron los valores más altos de carotenos (137.14 y 106.06 pg.cel-1, respectivamente. La cepa LB1644 presentó la mayor relación carotenoides totales:clorofila a (20:1 a 195 µE.m-2.s-1, mientras que en la cepa Coche no se evidenciaron diferencias significativas entre las dos intensidades (15:1. El resto de las cepas mostraron relaciones inferiores a uno. Nuestros resultados sugieren que las cepas Coche y Araya pueden ser potencialmente utilizadas en la biotecnología de producción de carotenoides.Carotenogenesis of five strains of the algae Dunaliella sp

  1. Tratamiento quirúrgico sin circulación extracorpórea de la fibrilación auricular aislada para la prevención secundaria de accidentes cerebrovasculares isquémicos agudos

    Directory of Open Access Journals (Sweden)

    Rafael Hernández-Estefanía

    2006-07-01

    Conclusiones: Nuestra experiencia inicial en el tratamiento de la FA aislada mediante ABVP con argón y sin CEC ofrece buenos resultados. Debe documentarse la persistencia del efecto y su eficacia en la reducción de los fenómenos tromboembólicos.

  2. 196. Predicción de disfunción ventricular izquierda irreversible tras cirugía de regurgitación aórtica aislada mediante cardiorresonancia magnética

    Directory of Open Access Journals (Sweden)

    L. Doñate Bertolín

    2012-04-01

    Conclusiones: La cRM es una herramienta útil para predecir disfunción ventricular irreversible tras cirugía de regurgitación aórtica aislada. El VTSVI permite predecir pacientes que quedan con dilatación ventricular y FE deprimida.

  3. Caracterización fenotípica de cepas invasivas de Neisseria meningitidis aisladas en Cuba durante 20 años

    Directory of Open Access Journals (Sweden)

    Isabel Martínez

    2006-04-01

    Full Text Available Se investigaron los marcadores epidemiológicos (serogrupos, serotipos, subtipos, inmunotipos de 429 cepas invasivas, aisladas en Cuba durante 20 años (1982-2002. Basándonos en el comportamiento de la incidencia de la Enfermedad Meningocócica (EM en el período investigado, las cepas se distribuyeron en dos etapas: epidémica y postepidémica. La epidémica, comprendió 279 cepas aisladas entre 1982-1992 y la ostepidémica, incluyó 150 aislamientos pertenecientes al período comprendido entre 1993-2002. Todas se cultivaron en Agar Mueller Hinton con suero fetal bovino (5% y se incubaron 24-48 horas, 37 0C, en atmósfera húmeda con 5% de C02. La identificación de género, especie y serogrupo, se realizó mediante métodos convencionales; para la caracterización de los sero/subtipos e inmunotipos, se utilizó el ensayo inmunoenzimático (ELISA de células enteras con anticuerpos monoclonales. En ambas etapas predominó el serogrupo B (97,90%: epidémica (96,77% y postepidémica (100%. Sin embargo, el serogrupo C (1,43% y cepas no agrupables (1,8%, sólo se observaron en aislamientos de la etapa epidémica. Los otros marcadores prevalentes fueron: serotipo 4 (86,48%, subtipo P1.19,15 (78,32%, inmunotipo L3,7,9 (90,2% , todos mostraron cifras similares en ambos períodos.Predominó el fenotipo B:4:P1.19,15:L3,7,9 (69,69%, aunque, en la etapa postepidémica (77,34%, el porcentaje fue superior al de la etapa epidémica (65,66% (p<0,05; además, en las cepas de este período, se observó una mayor diversidad de asociaciones fenotípicas. Los resultados obtenidos de esta caracterización fenotípica de las cepas de Neisseria meningitidis aisladas de enfermos aporta datos valiosos al estudio, prevención y control exitoso de la EM en Cuba.

  4. Evaluación serológica de una proteína recombinante a partir de una cepa aislada del virus de la fiebre amarilla en el Perú: un estudio piloto

    Directory of Open Access Journals (Sweden)

    Carlos Yábar V

    2003-10-01

    Full Text Available Objetivo: Evaluar serológicamente una proteína recombinante de 66 kDa (Er66 de una cepa del virus de la fiebre amarilla aislada en el Perú usando anticuerpos inmunoreactivos. Material y métodos: La proteína Er66 fue expresada in vitro en la bacteria Escherichia coli y enfrentada a títulos de 1/100, 1/50 y 1/25 de anticuerpos monoclonales, y a sueros con anticuerpos IgM e IgG inmunoreactivos contra el virus de la fiebre amarilla mediante ensayos de Western blot (WB. Asimismo, se evaluaron proteínas totales de las cepas de referencia del virus dengue (DEN y fiebre amarilla como controles de antigenicidad. Resultados: La proteína recombinante Er66 presentó antigenicidad contra títulos de 1/50 y 1/25 de anticuerpo monoclonal (MAB8701; sin embargo, no se observó inmunoreactividad en sueros positivos para fiebre amarilla y dengue. Los ensayos con extractos crudos de la cepa de fiebre amarilla Asibi 17D (PTFA revelaron que la antigenicidad de las proteínas virales comprendidas entre 60 y 80 kDa fue afectada negativamente a temperaturas desnaturalizantes de 100°C. En cambio, tratamientos con ß-mercaptoetanol sin calor generó un aumento de la antigenicidad de dichas proteínas. Siguiendo este mismo principio, la proteína Er66 fue sometida a tratamientos desnaturalizantes con ß-mercaptoetanol sin incluir calor y fue enfrentada nuevamente a los sueros reactivos. El resultado final reveló que la proteína Er66 generó inmunoreactividad frente a sueros con altos títulos de anticuerpos IgM e IgG para fiebre amarilla mientras que en otras muestras se observó una débil señal. Conclusiones: Los datos obtenidos en este trabajo demuestran que la Er66 pudo ser reconocida por anticuerpos IgM e IgG específicos para fiebre amarilla presentes en sueros de pacientes infectados. Los datos presentados en este artículo sugieren el uso de proteínas recombinantes como posibles candidatas de valor diagnóstico para la FA.

  5. The biological degradation as an energy option, determination of the effects of the aerobic phase on the subsequent production of biogas in a sanitary landfill; La degradacion biologica como una opcion energetica, determinacion de los efectos de la fase aerobia sobre la subsecuente produccion de biogas en un relleno sanitario

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar Juarez, Oscar [Asesoria de Servicios Ambientales del Bajio (ASSB), (Mexico)

    2010-07-01

    The present work deals with the energy evaluation of biological processes as energy source and is based on works concerning laboratory, pilot and field research. The objective of the research is to integrate the effect of the aerobic phase during the process of degradation of organic residues (basically the organic fraction of domestic residues), where the last aim is the biogas production. The usefulness of the results is reflected in the suitable estimation of the filling of a sanitary landfill considering the composition of the residues deposited and the effects that this management will have on the run-up time of the same and the velocity of biogas production. Finally, integrates a reflection on the intrinsic energy implications of the process and of the biogas yielding, which is evaluated as well as energy source. [Spanish] El presente trabajo trata sobre la valoracion energetica de procesos biologicos como fuente de energia y se basa en trabajos de investigacion a nivel de laboratorio, piloto y de campo. El objetivo de la investigacion es integrar el efecto de la fase aerobia durante el proceso de degradacion de residuos organicos (basicamente la fraccion organica de residuos domesticos), donde el fin ultimo es la produccion de biogas. La utilidad de los resultados se refleja en la estimacion adecuada del llenado de un relleno sanitario considerando la composicion de los residuos ahi depositados y los efectos que tendra esta gestion sobre el tiempo de estabilizacion de los mismos y la velocidad de produccion de biogas. Finalmente, se integra una reflexion sobre las implicaciones energeticas intrinsecas al proceso y del rendimiento de biogas, el cual a su vez es valorizado como fuente de energia.

  6. Naturally fermented Jijelian black olives: microbiological characteristics and isolation of lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    Karam, Nour-Eddine

    2009-12-01

    Full Text Available A study of the microflora of traditionally fermented black olives in Eastern Algeria is presented. A count of the following microbial groups was carried out: mesophilic bacteria, enterobacteria, lactic acid bacteria (LAB, staphylococci and yeast. In a second phase, the identification and assessment of the technological traits of LAB was performed. Seventeen lactic acid bacteria were isolated and identified. These isolates were represented by two genera: Lactobacillus and Leuconostoc. The results showed that Lactobacillus plantarum was the predominant species in this traditional product.Un estudio sobre la microflora de aceitunas negras fermentada por métodos tradicionales en el Este de Argelia es presentado. Se realizo el siguiente recuento de grupos de microorganismos: bacterias mesófilas, enterobacterias, bacterias ácido lácticas (LAB, staphylococcus y levaduras. En una segunda fase, la identificación y evaluación de aspectos tecnológicos de LAB fue realizada. Setenta bacterias ácido lácticas fueron aisladas e identificadas. Estos aislados contenían principalmente dos géneros: Lactobacillus y Leuconostoc. Los resultados mostraron que Lactobacillus plantarum fue la especie predominante en este producto tradicional.

  7. Empleo de la ultrafiltración extracorpórea aislada para el tratamiento de la insuficiencia cardiaca descompensada: dificultades técnicas y evolución clínica

    Directory of Open Access Journals (Sweden)

    José Luis Cobo Sánchez

    2013-12-01

    Full Text Available La ultrafiltración extracorpórea aislada se ha revelado como una posible estrategia terapéutica para pacientes con insuficiencia cardíaca descompensada resistente a diuréticos. Nuestro objetivo fue evaluar la evolución clínica a corto-medio plazo de los pacientes sometidos a ultrafiltración extracorpórea aislada y las incidencias técnicas/clínicas. Material y método: Estudio descriptivo transversal prospectivo en pacientes con insuficiencia cardíaca en estadio III-IV de la New York Heart Association resistentes al tratamiento diurético. La ultrafiltración extracorpórea aislada se realizó con el sistema Dedyca®, usando como acceso vascular un catéter venoso central. La tasa de ultrafiltración se iba ajustando en función de la tensión arterial del paciente. Para evaluar la evolución clínica se realizaron controles clínicos y analíticos antes y 1 mes después de las sesiones de ultrafiltración extracorpórea aislada. Para evaluar las complicaciones técnicas/clínicas se revisaron los registros de enfermería. Resultados: Se estudiaros 6 pacientes, que realizaron una media de 2 sesiones, con una duración media de 5 horas y una ultrafiltración media de 2100cc por sesión. Respecto a las complicaciones técnicas, sólo un paciente presentó coagulación parcial delsistema. Ningún paciente presentó efectos adversos durante la ultrafiltración extracorpórea aislada. Conclusiones: Tras la ultrafiltración extracorpórea aislada, aumenta la diuresis con la misma dosis de diurético e incluso con disminución progresiva. Es una técnica sencilla, sin complicaciones técnicas para enfermeras familiarizadas con técnicas de depuración extracorpórea.

  8. Aspectos pronósticos de la cirugía aislada de sustitución valvular tricuspídea

    Directory of Open Access Journals (Sweden)

    Ana Redondo Palacios

    2018-03-01

    Full Text Available Resumen: Introducción: La cirugía de sustitución valvular tricúspide (SVT aislada es una intervención poco frecuente, con una indicación controvertida, en gran parte debido a su mal pronóstico. Material y métodos: Se analizaron todos los pacientes intervenidos de SVT aislada entre los años 2003 y 2014. Se analizó: a Mortalidad perioperatoria y a largo plazo; y b Aparición de complicaciones relacionadas con las prótesis tricúspides a largo plazo (trombosis y degeneración protésica. Resultados: Durante el periodo de estudio se realizaron 40 intervenciones de SVT aislada. El 82,5% de los pacientes se encontraban en clase funcional iii/iv de la NYHA, y el 70% tenían hipertensión pulmonar al menos moderada (presión sistólica arterial pulmonar > 40 mmHg. La mortalidad perioperatoria fue del 25%, infraestimada por EuroSCORE I (mortalidad estimada del 13,89%. La anemia preoperatoria (OR: 0,52; IC 95%: 0,30-0,89; p = 0,017 se asoció con una mayor mortalidad perioperatoria. La reintervención se asoció con una tendencia a una mayor mortalidad perioperatoria (p = 0,081. La supervivencia tardía, tras 44 meses de seguimiento mediano, fue del 57,50%. Los factores significativamente asociados con una peor supervivencia en el seguimiento fueron: 1 Hipertensión pulmonar severa (OR: 5,77; IC 95%: 1,06-31,26; p = 0,042 y 2 Clase funcional iv (OR: 8,31; IC 95%: 1,48-49,06; p = 0,004. Los pacientes intervenidos en clase funcional iv de la NYHA presentaron una escasa supervivencia a largo plazo (12,5% de supervivencia al año; log rank p = 0,004. Conclusiones: La SVT aislada se asocia con una alta mortalidad, debido a la indicación de la intervención en avanzados estados de cardiopatía.La indicación de cirugía ha de hacerse de manera precoz, antes del deterioro de la función ventricular derecha o de la aparición de hipertensión pulmonar severa. La cirugía en clase funcional NYHA iv supone un escaso beneficio en t

  9. Igualdad de acceso a la telesanidad en zonas rurales y aisladas: propuesta de un marco ético normativo integral de acceso y distribución

    Directory of Open Access Journals (Sweden)

    María Graciela de Ortúzar

    2009-01-01

    Full Text Available Según la Asociación Médica Mundial, el uso de TICs (Tecnologías de la Información y Comunicaciones ¿ TICs- en salud, conocidas también como telesanidad y/o telemedicina, "es el ejercicio de la medicina a distancia, cuyas intervenciones, diagnósticos, decisiones de tratamientos y recomendaciones están bañadas en datos, documentos y otra información transmitida através de telecomunicación". Estas nuevas prácticas en el sistema de salud implican nuevos problemas éticos, legales, sociales, y tecnológicos que afectan los modelos actuales de atención de la salud. En términos generales, se ha priorizado el problema de la confidencialidad en el manejo de la información médica. Sin embargo, uno de los más importantes problemas éticos es justamente la igualdad de oportunidades en el acceso a TIC en salud (prevención, tratamiento, cura o rehabilitación. Por ello, el objetivo del presente trabajo constituye el lineamiento de un marco ético para evaluar el impacto en el acceso a la salud de los programas de telemedicina en zonas rurales y aisladas. En un segundo nivel, se analizará la regulación de uso de TICs en salud, considerando, responsabilidad profesional y social, respeto a la confidencialidad en el uso de la información médica (historias clínicas electrónicas y acceso a base de datos. La metodología utilizada es "equilibrio reflexivo" entre la teoría y la práctica. La hipótesis general que defenderé aquí es la necesidad de un marco ético integral para evaluar y regular el uso de programas de telemedicina en zonas rurales y aisladas, debido a que el impacto en la accesibilidad poblacional constituye el único sistema de salud alternativo para estas regiones.

  10. La dosificación de la intensidad en el desarrollo de la resistencia aerobia de los atletas de Marcha deportiva, categorías 16 -17 años de la ESPA Ormani Arenado de Pinar del Río

    Directory of Open Access Journals (Sweden)

    Ernesto Santana García

    2009-03-01

    Full Text Available La creciente demanda de recursos tecnológicos que presupone el deporte contemporáneo, pone en franca desventaja a los países en vías de desarrollo respecto a los llamados “del primer mundo”, a la vez que compromete a los primeros a redoblar sus esfuerzos intelectuales e investigativos para lograr compensaciones, a partir de la implementación de nuevas alternativas metodológicas accesibles y generalizables. Con el uso de diversas herramientas investigativas se pudo constatar que no se aplica por razones de imposibilidad real, la dosificación y el control de la intensidad para el entrenamiento aerobio a través de las zonas de rendimiento cardiorrespiratorio, pues no existen referencias suficientes sobre la relación entre estas y la velocidad de traslación, por lo cual se precisa de un pulsímetro y este elevaría grandemente el costo del proceso de preparación del deportista de  Marcha  Deportiva, por lo que, nos  planteamos como objetivo de  este trabajo:  proponer  una  alternativa  metodológica  para  contribuir a un  mejor control y dosificación de la intensidad en el desarrollo de la resistencia aerobia en los atletas de esta modalidad, categorías 16 -19 años. Para ello nos hemos auxiliado de herramientas investigativas tales como, el Análisis Síntesis, la inducción deducción, la encuesta y el análisis porcentual, entre otras. Los resultados alcanzados, tuvieron como referencia los criterios de entrenadores y las teorías más actualizadas, a partir de lo cual, se logra una alternativa metodológica que hace posible responder  al objetivo planteado.

  11. CLASIFICACIÓN POR MÉTODOS MOLECULARES DE CEPAS DE Trypanosoma spp AISLADAS EN COLOMBIA Y EVALUACIÓN MORFOMÉTRICA

    Directory of Open Access Journals (Sweden)

    E. Cassalett

    2006-01-01

    Full Text Available Mediante el empleo de técnicas de PCR-RFLP se caracterizaron tres cepas de tripanosomas aisladas de bovinos de diferentes regiones de Colombia, a partir de ampliÀcaciones de la región 18S de la subunidad ribosomal del rDNA del parásito. Para el PCR inicial se emplearon los primers específicos nF2 y nR3, y sobre el producto obtenido de 756 pb se realizó un PCR semianidado con los primers NF2 y NR2 de la misma región. Se obtuvo un producto 650 pb sobre el cual se realizó el análisis de restricción con las enzimas MspI y Eco57I , lo que permitió clasifícar las tres cepas analizadas como Trypanosoma vivax, Trypanosoma evansi y Trypanosoma theileri . El estudio morfométrico permitió corroborar diferencias morfológicas entre los parásitos clasificados. Se discute el uso de la técnica de PCR-RFLP como herramienta diagnóstica de la tripanosomosis bovina en Colombia.

  12. CLASIFICACIÓN POR MÉTODOS MOLECULARES DE CEPAS DE DE Trypanosoma spp AISLADAS EN COLOMBIA Y EVALUACIÓN MORFOMÉTRICA

    Directory of Open Access Journals (Sweden)

    Parra J. L.

    2006-11-01

    Full Text Available Mediante el empleo de técnicas de PCR-RFLP se caracterizaron tres cepas de tripanosomas aisladas de bovinos de diferentes regiones de Colombia, a partir de amplificaciones de la región 18S de la subunidad ribosomal del rDNA del parásito. Para el PCR inicial se emplearon los primers específicos nF2 y nR3, y sobre el producto obtenido de 756 pb se realizó un PCR semianidado con los primers NF2 y NR2 de la misma región. Se obtuvo un producto 650 pb sobre el cual se realizó el análisis de restricción con las enzimas MspI y Eco57I, lo que permitió clasificar las tres cepas analizadas como Trypanosoma vivax, Trypanosoma evansi y Trypanosoma theileri. El estudio morfométrico permitió corroborar diferencias morfológicas entre los parásitos clasificados. Se discute el uso de la técnica de PCR-RFLP como herramienta diagnóstica de la tripanosomosis bovina en Colombia.

  13. Caracterización Molecular de Bacterias Patógenas Cultivables presentes en las vías Respiratorias de Pacientes Peruanos con Fibrosis Quística

    OpenAIRE

    Aquino Ordinola, Ruth Elizabeth

    2016-01-01

    RESUMEN En los pacientes con Fibrosis Quística (FQ), la morbilidad y la mortalidad se asocian principalmente a infecciones microbianas crónicas de las vías respiratorias inferiores. En el presente trabajo las comunidades bacterianas cultivables procedentes de muestras de esputo de 21 pacientes pediátricos fueron identificadas a nivel molecular. Las bacterias fueron aisladas mediante técnicas microbiológicas estándares, mientras que la caracterización de las cepas puras se realizó por sec...

  14. Evaluación de la actividad fungistática in vitro de bacterias ácido lácticas contra especies de Fusarium causantes de pudrición basal en pitahaya amarilla (Selenicereus megalanthus Haw)

    OpenAIRE

    Valencia Hernández, Leidy J

    2015-01-01

    Fusarium sp. Es uno de los principales hongos fitopatógenos causantes de enfermedades en pitahaya amarilla. Estudios previos han demostrado la capacidad antimicrobiana de bacterias ácido lácticas (BAL) contra patógenos; sin embargo no se ha reportado en la literatura científica actividad fungistática de BAL contra especies de Fusarium causantes de pudrición basal en pitahaya amarilla. En este trabajo se evaluó in vitro la actividad fungistática de una BAL aislada de cultivos de pitahaya amari...

  15. Repercusiones en la salud pública de la resistencia a quinolonas en bacterias de origen animal QUINOLONAS EN BACTERIAS DE ORIGEN ANIMAL

    Directory of Open Access Journals (Sweden)

    José Antonio Orden Gutiérrez

    2001-01-01

    Full Text Available Las fluoroquinolonas son una de las clases de agentes antimicrobianos más útiles empleadas hoy en día en medicina humana y animal debido a su espectro y a sus propiedades fisicoquímicas. El uso de quinolonas en animales es un asunto de especial preocupación porque podría contribuir a la adquisición de resistencia en bacterias transmitidas por alimentos (tales como Salomonella spp., Campylobacter spp. y Escherichia coli y esto, a su vez, podría conducir a una reducción en la eficacia de tales componentes en el tratamiento de infecciones en los seres humanos. Sin embargo, la relación causal entre el uso de fluoroquinolonas en medicina veterinaria y el aislamiento de bacterias resistentes a fluoroquinolonas en humanos no ha sido generalmente probada y, además, el uso de fluoroquinolonas en animales es sólo uno de los muchos factores implicados en la resistencia a estos antimicrobianos. A pesar de ello, la vigilancia de la resistencia a fluoroquinolonas en bacterias aisladas de animales y alimentos y el uso adecuado de estos antimicrobianos en animales deben tener la máxima prioridad.

  16. Caracterización genotípica y fenotípica de cepas emergentes de Escherichia coli aisladas de niños con diarrea en Bucaramanga y su área metropolitana, Colombia

    Directory of Open Access Journals (Sweden)

    Monica Yurley Arias Guerrero

    2016-06-01

    Full Text Available Introducción: La enfermedad diarreica aguda (EDA sigue siendo uno de los principales problemas en salud pública en países en desarrollo. Dentro de los agentes infecciosos que causan esta enfermedad se encuentran bacterias, virus y parásitos. Los agentes bacterianos ocupan un segundo lugar destacándose Escherichia coli enteropatógenas entre las más importantes. Actualmente, seis cepas con diferentes mecanismos de patogenicidad están asociados a diarrea  E. coli enteropatógena (ECEP, productora de toxina-shiga (ECTS, enterotoxigénica (ECET, enteroinvasiva (ECEI, enteroagregativa (ECEA y adherente difusa (ECAD, cada una con un set específico de genes de virulencia. No obstante, se han reportado brotes de EDA ocasionados por cepas de E. coli diferentes a los patotipos conocidos, denominadas cepas emergentes. Estos brotes han sido reportados en Alemania, Europa y recientemente en Cartagena Colombia, lo que sugiere que en nuestro medio circulan estas cepas. Por lo cual, es necesario caracterizar estas cepas emergentes. Objetivo: Caracterizar genotípicamente y fenotípicamente dos cepas emergentes de E. coli aisladas de muestras diarreicas en niños menores de cinco años en Bucaramanga, Colombia. Materiales y métodos: De un estudio de casos y controles realizado entre Julio del 2013 y diciembre del 2014 en Bucaramanga y su área metropolitana, Colombia a 860 niños menores de 5 años con diarrea (casos y sin diarrea (controles. Se aislaron a partir de coprocultivos cepas de E. coli mediante pruebas bioquímicas. A estas cepas previamente almacenadas a -80°C se les determino mediante PCR multiplex los patotipos de E. coli, los cuales posteriormente fueron confirmados mediante PCR simple. Muestras positivas para dos patotipos u otra característica fueron clasificadas como cepas emergentes. Finalmente, estas cepas se caracterizaron fenotípica y genotípicamente. Para ello, se llevaron a cabo pruebas como secuenciación de genes de

  17. Inhibition of the growth of Ascosphaera apis by Bacillus and Paenibacillus strains isolated from honey Inhibición del crecimiento de Ascosphaera apis mediante cepas de Bacillus y Paenibacillus aisladas de miel

    Directory of Open Access Journals (Sweden)

    F. J. Reynaldi

    2004-03-01

    Full Text Available The fungus Ascosphaera apis, the causative agent of chalkbrood disease in honeybee larvae, occurs throughout the world and is found in many beekeeping areas of Argentina. The potential as biocontrol agents of 249 aerobic spore-forming bacterial antagonists isolated from honey samples was evaluated. Each isolate was screened against A. apis by a central disk test assay. Ten bacterial strains that showed the best antagonistic effect to A. apis were selected for further study and identified as Bacillus cereus (m363, mv86, mv81, mv75, Bacillus circulans (Fr231, m448b, Bacillus megaterium (m435, Bacillus pumilus (m354, Bacillus subtilis (m329, and Paenibacillus alvei (m321. For testing the efficiency of the selected strains, a paired culture test was used with 5 replicates of each combination bacterial antagonist / A. apis strain, and 5 replications for each control on 4 different culture media. The analysis of variance and posterior comparison of means according to LSD method showed that the best antagonists when using YGPSA medium were B. subtilis (m329 and B. megaterium (m435, and in the case of MYPGP medium the most efficient were B. circulans strains Fr 231 and m448b.La cría yesificada es una micosis invasiva ocasionada por el hongo heterotálico Ascosphaera apis que afecta exclusivamente a las larvas de las abejas. La enfermedad tiene difusión mundial y en la Argentina se halla diseminada en todas las áreas donde se realiza apicultura. Se estudió la potencialidad de 249 cepas de bacterias esporuladas aeróbicas aisladas de miel como agentes biocontroladores del hongo mediante un ensayo en disco central en condiciones de laboratorio. Se seleccionaron como mejores antagonistas 10 cepas bacterianas identificadas como Bacillus cereus (m363, mv86, mv81, mv75, Bacillus circulans (Fr231, m448b, Bacillus megaterium (m435, Bacillus pumilus (m354, Bacillus subtilis (m329, y Paenibacillus alvei (m321. Para probar la eficiencia de las cepas

  18. Sensibilidad antimicrobiana y caracterización de cepas de Streptococcus pyogenes aisladas de un brote de escarlatina

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    Pedraza-Avilés Alberto González

    2002-01-01

    Full Text Available Objetivo. Evaluar la actividad in vitro de 13 antibióticos contra 47 Streptococcus pyogenes grupo A (SGA. Determinar la presencia de genes que codifican para exotoxina pirogénica estreptocóccica A (SpeA y serotipos con base en proteína M. Material y métodos. Estudio transversal hecho en el Centro de Salud Dr. José Castro Villagrana sobre un brote de escarlatina en el Colegio Espíritu de América, entre diciembre de 1999 y enero de 2000. El número de niños estudiados fue 137. Se extrajeron porcentajes de sensibilidad. La concentración inhibitoria mínima (CIM se obtuvo por microdilución semiautomatizada. Se utilizó un secuenciador automatizado de DNA para el análisis de variación de secuencias en los genes que codifican para proteína M y SpeA. Resultados. Todas las cepas fueron sensibles a beta-lactámicos y clindamicina; 12.7% fueron resistentes a eritromicina. El serotipo M2 fue el más frecuente, 27 del total. Prácticamente todas las bacterias (96% con el gen SpeA tienen el gen que codifica para el serotipo M2. Conclusiones. Debido a la reciente reaparición de infecciones por SGA se sugiere realizar estudios tanto de sensibilidad a macrólidos y beta-lactámicos, como de epidemiología molecular.

  19. Extracción optimizada y purificación parcial de invertasa aislada de S. Cerevisiae en puré de durazno

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    Marcela Vega Ferreira

    2018-03-01

    Full Text Available Resumen La extracción fue realizada a través de un proceso de autolisis, donde las enzimas degradan las estructuras celulares y liberan el contenido citoplasmático al medio extracelular. El proceso de autolisis fue realizado en shaker con diferentes velocidades de agitación (50 - 350 rpm y concentraciones de bicarbonato de sodio (50 -350 mM NaHCO3 a 40 °C por 24 horas, usando un diseño experimental compuesto central adaptado para dos variables y cinco niveles, así como una metodología de superficie de respuest a (MSR y análisis canónico para definir las condiciones óptimas de extracción de invertasa de S. cerevisiae aislada de puré de durazno (ISc. En la condición optima de extracción, se estudió el efecto de la liofilización y purificación en la actividad de la invertasa, usando el método colorimétrico del ácido 3,5-dinitrosalicílico (DNS a 490 nm para acompañar su actividad expresada en unidades. Una unidad (U es definida como 1 mg glucosa.min-1. El valor de proteínas fue cuantificado por el método Lowry y la invertasa de levadura comercial (ILC como testigo. La influencia de la concentración de NaHCO3 y de la velocidad de agitación en la extracción de la enzima invertasa indicó efecto lineal, cuadrático e interactivo. El modelo de forma polinómica de segundo orden explicó el fenómeno de extracción de la invertasa con un R2 de 0,80, y con actividad significativamente dependiente de ambas variables. La máxima extracción fue observada en el punto central experimental (200 mM NaHCO3 y 200 rpm con una actividad de 14,7 U.mg-1. El punto estacionario es un punto de máxima extracción, el cual difiere en menos de 10% del punto central experimental. De acuerdo a estas características, las óptimas condiciones para extracción de la invertasa de S. cerevisiae aislada de puré de durazno son 200 mM NaHCO3 como agente de autolisis, 200 rpm de agitación orbital a 40oC durante 24 horas y usando una biomasa de

  20. La capacidad de trabajo funcional de las practicantes de Gimnasia Aerobia de Salón en correspondencia con las edades de 18 a 50 años de las escuelas comunitarias del municipio de Pinar del Río

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    Luis Alberto Mojena Rodríguez

    2009-06-01

    Full Text Available Con nuestro trabajo pretendemos brindar un valioso aporte para resolver una de las principales problemáticas que afrontan hoy en día los docentes que imparten  el  programa  de  gimnasia  aerobia  de  salón  ya  que  la  idea  es establecer rangos que nos permita evaluar de B, R y M la capacidad física de resistencia cardiovascular, contribuyendo a que este su principal objetivo se desarrolle sobre bases mas científicas , mediante la aplicación del test de Cooper a practicantes entrenados en las edades comprendidas entre 18 y 50 años  del  sexo  femenino, teniendo  en  cuenta  como  principal  medidor  el consumo máximo de oxigeno para evaluar dicha prueba, que la aplicaremos en tres momentos con dos meses de tiempo de aplicación entre una medición y otra que nos brindara en que por ciento debe mejorar su rendimiento o incrementar la mejoría en esta capacidad entre cada prueba que seria el principal aporte de nuestra investigación premisa la resistencia se puede definir como la capacidad psíquica y física que posee un deportista para resistir la fatiga (Weineck 1992, entendiéndose como fatiga la disminución transitoria de la capacidad de rendimiento. Es la capacidad de realizar un esfuerzo de mayor o menor intensidad, durante el mayor tiempo posible. La capacidad de oposición a la fatiga. Es la lucha para la mejora de la capacidad de absorción de O, ya que cuando se incrementa la intensidad de los esfuerzos, mayor es la necesidad de un aporte de oxígeno. Desde el punto de vista bioquímico,  la resistencia se determina por la relación entre la cantidad de las reservas energéticas dispuestas para su utilización y la velocidad de consumo de la energía durante la práctica deportiva (Menshikov y Volkov 1990. La resistencia tiene como sustrato morfo-funcional  al aparato cardiocirculatorio y respiratorio.  El aparato cardiovascular controla la cantidad de sangre que el corazón bombea y la circulaci

  1. Estudio del sistema regulador formado por la serotonina y sus receptores en las células troncales MSC aisladas de médula ósea humana. Adipogénesis.

    OpenAIRE

    González Méndez, Laura

    2014-01-01

    Tesis doctoral inédita, leída en Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de lectura: 21/03/2014 En los últimos años se ha identificado a la serotonina como un regulador crítico de la masa ósea, regulando tanto directa como indirectamente la actividad de las células responsables del proceso de remodelación ósea, osteoclastos y osteoblastos. El presente trabajo muestra que las MSCs aisladas de la médula ósea humana, células precursoras ...

  2. Analisis tecnico, socioeconomico y ambiental de la electrificación con energía solar fotovoltaica aislada para vivienda rural en Hato Corozal, Casanare, Colombia

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    Edwin Blasnilo Rúa Ramírez

    2017-06-01

    Full Text Available La electrificación con energía solar fotovoltaica aislada es la opción más viable para vivienda rural, en especial si se encuentra muy distante del sistema nacional interconectado. Hato Corozal, Casanare, Colombia, es un municipio estructurado en su área rural por fincas muy alejadas entre sí. Su mayor inconveniente de desarrollo social y económico es la falta de electricidad como servicio de primera necesidad.  La gobernación de Casanare a través del fondo nacional de regalías aprobó la instalación de 206 sistemas solares fotovoltaicos (SFV a las familias más alejadas y más vulnerables del municipio. El objetivo principal de esta investigación fue realizar una evaluación socio-económica de las familias de la zona rural del municipio, beneficiadas con la instalación de estos sistemas SFV. Además, se realizó un análisis técnico de simulación de la operación del SFV dimensionado con 2 días sin sol y luego 12 días con sol, también se hizo una simulación de la operación del SFV dimensionado con 14 días con sol. Esta investigación se abordó desde el enfoque metodológico descriptivo y de investigación aplicada de campo que incluyó visita a las viviendas, aplicación, análisis de instrumentos y registro fotográfico.  Los resultados presentan gran incidencia desde un enfoque social, económico y ambiental que puede llegar a ser implementado en otras áreas rurales del país como ejemplo de uso de tecnologías limpias en favor del desarrollo rural sostenible.

  3. Identificación y caracterización de especies de Neosartorya aisladas de frutillas (Fragaria spp. frescas y tratadas térmicamente

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    Laura Frisón

    2012-12-01

    Full Text Available El género Aspergillus es uno de los géneros fúngicos más estudiados y de gran impacto a nivel industrial. La sección Fumigati incluye unas pocas especies anamorfas del género Aspergillus. Las especies que son teleomorfas se encuentran dentro del género Neosartorya. Este es un moho resistente al calor que causan problemas en las industrias alimentarias o enfermedades en los seres humanos. Sus ascosporas han sido aisladas a partir de frutas, pulpas y jugos, ya que pueden sobrevivir a los tratamientos de térmicos industriales pudiendo aparecer la contaminación post-pasteurización. El objetivo fue caracterizar aislados de Neosartorya de frutillas frescas recién cosechadas y tratadas térmicamente, analizando la ornamentación de las ascosporas, toxicidad y resistencia térmica. Se aislaron las colonias, y se identificaron macro y microscópicamente siguiendo la metodología de Pitt y Hocking (2009, de 60 muestras. Se caracterizaron las ascosporas por microscopía electrónica de barrido. Se determinó la capacidad toxicogénica de los extractos por cromatografía líquida de alta eficiencia. Se evaluó la resistencia térmica a diferentes temperaturas. Se aislaron 18 cepas de Neosartorya de frutillas recién cosechadas, y otros mohos termorresistentes como Arthrinium phaeospermum, Byssochlamys nivea y Talaromyces macrosporus. En las frutillas tratadas térmicamente no se aislaron mohos termorresistentes. Trece aislados mostraron ascosporascoincidentes con N. fischeri, el resto con N. spinosa. Los aislados de N. fischeri produjeron fumitremorgina A y B y verruculógeno en arroz, pero no lo hicieron en frutillas frescas. Los parámetros de resistencia térmica fueron: D80 ºC: 20 - 22 minutos, D85 ºC: 9 - 11 minutos, D90 ºC: 2 - 3 minutos y z: 10 - 11 ºC para N. fischeri y D80 ºC: > 120 minutos, D85 ºC: 11 - 94 minutos, D90 ºC: 3 - 15 minutos y z: 6 - 9 ºC para N. spinosa. Es indispensable aplicar buenas prácticas agrícolas y

  4. Identificación y caracterización de especies de Neosartorya aisladas de frutillas (Fragaria spp. frescas y tratadas térmicamente

    Directory of Open Access Journals (Sweden)

    Laura Frisón

    2012-01-01

    Full Text Available El género Aspergillus es uno de los géneros fúngicos más estudiados y de gran impacto a nivel industrial. La sección Fumigati incluye unas pocas especies anamorfas del género Aspergillus. Las especies que son teleomorfas se encuentran dentro del género Neosartorya. Este es un moho resistente al calor que causan problemas en las industrias alimentarias o enfermedades en los seres humanos. Sus ascosporas han sido aisladas a partir de frutas, pulpas y jugos, ya que pueden sobrevivir a los tratamientos de térmicos industriales pudiendo aparecer la contaminación post-pasteurización. El objetivo fue caracterizar aislados de Neosartorya de frutillas frescas recién cosechadas y tratadas térmicamente, analizando la ornamentación de las ascosporas, toxicidad y resistencia térmica. Se aislaron las colonias, y se identificaron macro y microscópicamente siguiendo la metodología de Pitt y Hocking (2009, de 60 muestras. Se caracterizaron las ascosporas por microscopía electrónica de barrido. Se determinó la capacidad toxicogénica de los extractos por cromatografía líquida de alta eficiencia. Se evaluó la resistencia térmica a diferentes temperaturas. Se aislaron 18 cepas de Neosartorya de frutillas recién cosechadas, y otros mohos termorresistentes como Arthrinium phaeospermum, Byssochlamys nivea y Talaromyces macrosporus. En las frutillas tratadas térmicamente no se aislaron mohos termorresistentes. Trece aislados mostraron ascosporas coincidentes con N. fischeri, el resto con N. spinosa. Los aislados de N. fischeri produjeron fumitremorgina A y B y verruculógeno en arroz, pero no lo hicieron en frutillas frescas. Los parámetros de resistencia térmica fueron: D80 ºC: 20 - 22 minutos, D85 ºC: 9 - 11 minutos, D90 ºC: 2 - 3 minutos y z: 10 - 11 ºC para N. fischeri y D80 ºC: > 120 minutos, D85 ºC: 11 - 94 minutos, D90 ºC: 3 - 15 minutos y z: 6 - 9 ºC para N. spinosa. Es indispensable aplicar buenas prácticas agrícolas y

  5. Portadores de Neisseria meningitidis, caracterización de las cepas aisladas y respuesta inmune basal a VA-MENGOC-BC

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    María J. Valdés

    2008-08-01

    Full Text Available Con el propósito de conocer la prevalencia de portadores de Neisseria meningitidis en un grupo de adolescentes, los marcadores epidemiológicos de las cepas aisladas, así como los factores de riesgo asociados con el estado de portador y la respuesta inmune basal a VA-MENGOC-BC , se realizó un estudio transversal descriptivo de portadores en 189 estudiantes de 12-19 años de un politécnico de Ciego de Ávila, siguiendo las Normas Bioéticas establecidas. A los estudiantes se les realizó un exudado faríngeo y una extracción de sangre para la obtención de suero, así como una encuesta relacionada con aspectos de la investigación. La identificación de N. meningitidis se hizo por el sistema API NH (bioMérieux. Los serosubtipos e inmunotipos se clasificaron por ELISA de células enteras con anticuerpos monoclonales y la respuesta inmune basal se detectó por el Ensayo Bactericida del Suero. Se determinó la susceptibilidad antimicrobiana de las cepas frente a la penicilina, cloranfenicol, rifampicina, sulfadiacina sódica, ceftriaxona y ciprofloxacina. La prevalencia de portadores de N. meningitidis fue del 17%. Predominaron las cepas no agrupables (84,7%, seguidas por los serogrupos B (12,5% y Z (3,1%, destacándose la ausencia del C. Prevaleció el fenotipo NA:NT:P1.NST:L3,7,9 (12,5%, las cepas resistentes a la sulfadiacina (78,2% y sensibles a penicilina (81,3%, aunque el 18,7% mostró sensibilidad intermedia a este fármaco. Al resto de los antimicrobianos todas fueron sensibles. Se constató una respuesta inmune de memoria a la vacuna antimeningocócica (VAMENGOC-BC®, 12 años después de su aplicación, con títulos bactericidas anti C y B de 25 y 42%, respectivamente, resultados que pudieran estar influenciados por la inmunización sistemática que se realiza en Cuba con esta vacuna desde 1991.

  6. Análisis de una cepa de Yersinia enterocolitica aislada de heces diarreicas humanas en Argentina Analysis of a Yersinia enterocoliticaisolated from human diarreic feces in Argentina

    Directory of Open Access Journals (Sweden)

    M. Paz

    2004-12-01

    Full Text Available Algunos serotipos de Yersinia enterocolitica ocasionan desde diarreas hasta infecciones invasivas. El objetivo del trabajo fue analizar factores de virulencia y marcadores asociados en una cepa de Y. enterocolitica aislada de heces diarreicas humanas. El aislamiento deY. enterocolitica analizado fue incluído dentro del sub-grupo 1A.La determinación de resistencia al suero humano normal e hidrofobicidad de superficie, así como la búsqueda de los genes vir F y ail, resultaron negativos. Se demostró sin embargo producción de enterotoxina a 20 °C y también a 37 °C en condiciones de osmolaridad y pH similares a las del intestino humano. La enterotoxina, presentó reactividadpor la prueba del ratón lactante, aunque no se pudo comprobarpor PCR la presencia del gen yst. Los resultados obtenidos por nosotros, coincidentes con los de otros investigadores, indican que ciertos aislamientos clínicos de Y. enterocolitica del biotipo 1A (“avirulentas”, son capaces de causar enfermedad, probablemente a través de otros mecanismos, distintos a los caracterizados en especies de Yersinia enteropatógenas.Some serotypes of Yersinia enterocoliticamight causediarrheas and/or invasive infections. The aim of this work was to analyze virulence factors and associated markers in a strain of Y. enterocolitica isolated from human diarrheic feces. The strain analyzed was included in the biotype 1A. The virulence markers determinationas well as the search of the genes vir F and ail,were negatives. However, it was demonstratedenterotoxin production at 20 °C, andat 37 °C in osmolarity conditions and pH similar to the human intestine. The enterotoxin presented reactivity for the infant mouse test, although it could not be proven the presence of yst gene by PCR. The results obtained by us, coincident with those of other investigators,indicated that certain clinical isolates of Y. enterocolitica of the biotype 1A (“avirulent”, could be the etiological agent of

  7. Bleach vs. Bacteria

    Science.gov (United States)

    ... Articles | Inside Life Science Home Page Bleach vs. Bacteria By Sharon Reynolds Posted April 2, 2014 Your ... hypochlorous acid to help kill invading microbes, including bacteria. Researchers funded by the National Institutes of Health ...

  8. Phenotypic characterization of Clostridium botulinum strains isolated from infant botulism cases in Argentina Caracterización fenotípica de cepas de Clostridium botulinum aisladas de casos de botulismo del lactante en Argentina

    Directory of Open Access Journals (Sweden)

    M. D. Sagua

    2009-09-01

    Full Text Available Infant botulism is the most common form of human botulism; however, its transmission has not been completely explained yet. Some of the most recognized potential sources of Clostridium botulinum spores are the soil, dust, honey and medicinal herbs. In Argentina, 456 cases of infant botulism were reported between 1982 and 2007. C. botulinum type A was identified in 455 of these cases whereas type B was identified in just one case. However, in Argentina, types A, B, E, F, G, and Af have been isolated from environmental sources. It is not clearly known if strains isolated from infant botulism cases have different characteristics from strains isolated from other sources. During this study, 46 C. botulinum strains isolated from infant botulism cases and from environmental sources were typified according to phenotypic characteristics. Biochemical tests, antimicrobial activity, and haemagglutinin-negative botulinum neurotoxin production showed uniformity among all these strains. Despite the variability observed in the botulinum neurotoxin's binding to cellular receptors, no correlation was found between these patterns and the source of the botulinum neurotoxin. However, an apparent geographical clustering was observed, since strains isolated from Argentina had similar characteristics to those isolated from Italy and Japan, but different to those isolated from the United States.El botulismo del lactante es la forma más común del botulismo humano; sin embargo, su forma de transmisión no ha sido totalmente explicada. El suelo, el polvo ambiental, la miel y algunas hierbas medicinales son potenciales fuentes de esporas de Clostridium botulinum. Entre 1982 y 2007 se informaron en Argentina 456 casos de botulismo del lactante, 455 casos debidos al serotipo A y uno al serotipo B. Sin embargo, los serotipos A, B, E, F, G y Af han sido aislados de suelos y otras fuentes en Argentina. No se conoce si las cepas aisladas de casos de botulismo del lactante

  9. Isolation of lactic acid bacteria for its possible use in the fermentation of green algerian olives

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    Nour-Eddine, Karam

    2004-12-01

    Full Text Available This study was undertaken with the aim of obtaining lactic acid bacteria with the ability to ferment olives for possible use as starter cultures. For this reason, 32 isolates of lactic acid bacteria isolated from the spontaneous fermentation of green olives were characterized and identified on the basis of morphological and biochemical criteria. 14 of them were identified as Lactococcus lactis, 11 isolates as Lactobacillus plantarum and 7 isolates as Enterococcus sp. Of the 18 isolates examined for antagonistic activity, 3 isolates of Lactobacillus plantarum and one isolate of Enterococcus sp. were able to give distinct zones of inhibition against 5 indicator strains of lactic acid bacteria isolated in this study. Cell free supernatant of Lactobacillus plantarum OL9 was active against Gram-positive bacteria (Lactobacillus, Enterococcus and Propionibacterium and also against one Gram-negative bacteria strain of spoilage significance (Erwinia.Este estudio se emprendió con el objetivo de obtener bacterias del ácido láctico con capacidad para utilizarse como cultivo iniciador en la fermentación de aceitunas. Por esta razón, 32 cepas de bacterias del ácido láctico procedentes de fermentaciones espontáneas de aceitunas verdes se caracterizaron e identificaron en función de criterios morfológicos y bioquímicos. Catorce cepas se identificaron como Lactococcus lactis, 11 cepas como Lactobacillus plantarum y 7 cepas como Enterococcus sp. De las 18 cepas que se examinaron para detectar actividades antagónicas, se encontró que 3 cepas de Lactobacillus plantarum y una de Enterococcus sp. mostraban zonas de inhibición contra 5 cepas indicadoras de bacterias del ácido láctico aisladas en este estudio. El sobrenadante libre de células Lactobacillus plantarum OL9 fue activo contra diversas bacterias Gram-positivas (Lactobacillus, Enterococcus y Propionibacterium y contra una cepa de bacteria Gram-negativa relacionada con alteraciones (Erwinia.

  10. Distribución Diferencial de Bacterias con Potencial Biocontrolador de Spongospora subterranea en Plantas de Papa (Solanum tuberosum cv. Diacol Capiro Differential Distrubution of Candidadate Biocontrol Bacteria against Spongospora subterranea in Potato Plants (Solanum tuberosum cv. Diacol Capiro

    Directory of Open Access Journals (Sweden)

    Juliana Soler Arango

    2012-06-01

    Full Text Available Resumen. La búsqueda de microorganismos promisorios para biocontrol de patógenos de plantas en el suelo con frecuencia se ha orientado a la detección de productores de hormonas y enzimas líticas, condiciones asociadas a su capacidad para promover crecimiento vegetal. Sin embargo, el suelo es altamente variable en escalas pequeñas y se conoce poco sobre la distribución espacial de microorganismos que expresan esas funciones. Este estudio determinó la capacidad de producción de indoles totales y quitinasas en bacterias cultivables aisladas del interior de la raíz, la rizósfera, la superficie de los tubérculos o suelo de un cultivo de papa (Solanum tuberosum variedad Diacol Capiro. Las muestras se obtuvieron en un campo comercial en el municipio de la Unión en el departamento de Antioquia, Colombia, en plantas que presentaban síntomas de infección por Spongospora subterranea. Se encontró una producción diferencial de indoles o quitinasas según el sitio de aislamiento de las bacterias. No se encontró una alta producción de ambas actividades en un sólo aislamiento, la mayor producción de indoles totales y quitinasas se encontró en bacterias aisladas a partir de raíz y rizósfera, comparada con las aisladas de tubérculos y suelo. Estos resultados sugieren que en el suelo no es aleatoria la distribución de funciones deseables en controladores biológicos. Con estos resultados es posible orientar su búsqueda para optimizar el uso de recursos y el desarrollo de nuevos bioproductos.Abstract. Searching for promising microorganisms to biocontrol soil-borne plant pathogens has been often focused on producers of hormone and lytic enzymes, since these traits are linked to plant growth promotion. However, the environment from inner roots to bulk soil is quite variable, and little is known about the spatial distribution of microorganisms expressing these desirable traits. Using potato plants (Solanum tuberosum var. Diacol Capiro from a

  11. Lactic acid bacteria from "Sheep's Dhan", a traditional butter: Isolation, identification and major technological traits

    Directory of Open Access Journals (Sweden)

    2009-06-01

    Full Text Available Twenty six lactic acid bacteria were isolated from sheep’s Dhan, a traditional butter made from sheep’s milk in Jijel (East of Algeria. These strains belong to three genera: Lactococcus, Leuconostoc and Lactobacillus. The results showed that Lactococcus lactis ssp diacetylactis was the predominant species in this traditional butter. The results of the assessment of the technological aptitude indicate that a major strain has a good acidification aptitude, some of them show good proteolytic activity and only Leuconostoc mesenteroides ssp. dextranicum isolates were able to produce exopolysaccharide.

    Veintiséis bacterias lácticas fueron aisladas de “Sheep´s Dhan”, una mantequilla tradicional hecha con leche de oveja en Jijel (al Este de Argelia. Estas cepas pertenecen a tres géneros: Lactococcus, Leuconostoc y Lactobacillus. Los resultados mostraron que Lactococcus lactis ssp diacetylactis fue la especie predominante en esta mantequilla tradicional. Los resultados de la evaluación de la aptitud tecnológica indican que la principal cepa tiene una buena aptitud de acidificación, algunas de ellas mostraron una buena actividad proteolítica y únicamente Leuconostoc mesenteroides ssp. dextranicum fue capaz de producir exopolisacárido.

  12. Genomics of Probiotic Bacteria

    Science.gov (United States)

    O'Flaherty, Sarah; Goh, Yong Jun; Klaenhammer, Todd R.

    Probiotic bacteria from the Lactobacillus and Bifidobacterium species belong to the Firmicutes and the Actinobacteria phylum, respectively. Lactobacilli are members of the lactic acid bacteria (LAB) group, a broadly defined family of microorganisms that ferment various hexoses into primarily lactic acid. Lactobacilli are typically low G + C gram-positive species which are phylogenetically diverse, with over 100 species documented to date. Bifidobacteria are heterofermentative, high G + C content bacteria with about 30 species of bifidobacteria described to date.

  13. Chemotactic responses to gas oil of Halomonas spp. strains isolated from saline environments in Argentina Respuesta quimiotáctica hacia gas oil de cepas de Halomonas spp. aisladas de ambientes salinos de Argentina

    Directory of Open Access Journals (Sweden)

    Sebastián D´Ippólito

    2011-06-01

    Full Text Available In this study, two halophilic bacterial strains isolated from saline habitats in Argentina grew in the presence of gas oil. They were identified as Halomonas spp. and Nesterenkonia sp. by 16S ribosomal RNA sequencing. Chemotaxis towards gas oil was observed in Halomonas spp. by using swimming assays.En el presente trabajo se aislaron dos cepas bacterianas halofílicas a partir de muestras obtenidas en ambientes salinos de Argentina, que crecieron en presencia de gasoil como única fuente de carbono. Las cepas aisladas se identificaron como Halomonas spp. y Nesterenkonia sp. mediante secuenciación del gen del ARN ribosomal 16S. En ensayos de swimming, las cepas del genero Halomonas spp. mostraron una respuesta quimiotáctica hacia el gas oil.

  14. Microbiological study of naturally fermented Algerian green olives: isolation and identification of lactic acid bacteria and yeasts along with the effects of brine solutions obtained at the end of olive fermentation on Lactobacillus plantarum...

    Directory of Open Access Journals (Sweden)

    Nour-Eddine, Karam

    2006-09-01

    Full Text Available The microflora of naturally fermented green olives produced in Western Algeria was studied over 15, 60 and 90 day fermentation periods. Different microorganisms (aerobic bacteria, coliforms, staphylococci, lactic acid bacteria, lactobacilli, enterococci, yeasts, psychrotrophs and lipolytic bacteria were recorded at 15 and 60 days of fermentation. After 90 days (pH 4.40 of fermentation, the lactic acid bacteria population became dominant and persisted together with yeasts throughout the fermentation period. The lactic acid bacteria isolated (343 isolates were identified as L. casei, L. rhamnosus, L. paracasei, L. plantarum, L. lactis subsp. lactis, E. faecalis, E. faecium and E. durans. The dominant species was L. plantarum. Yeasts were isolated from all samples (32 isolates and were identified as Saccharomyces cerevisiae or Candida parapsilosis. Also, in this study we reported that brine solutions obtained at the end of olive fermentation were able to stimulate the growth of several L. plantarum strainsLa microflora de las aceitunas verdes fermentadas naturalmente elaboradas en Argelia Occidental fue estudiada en períodos de fermentación de 15, 60 y 90 días. Diferentes microorganismos (bacterias aeróbicas, coliformes, estafilococos, bacterias del ácido láctico, lactobacilos, enterococos, levaduras, psicotrofos y bacterias lipolíticas fueron detectados a los 15 y 60 días de fermentación. Después de 90 días de fermentación (pH 4.40, la población de bacterias lácticas se hizo dominante y persistió junto con las levaduras a lo largo de todo el proceso. Las bacterias lácticas aisladas (343 fueron identificadas como L. casei, L. rhamnosus, L. paracasei, L. plantarum, L. lactis subsp. lactis, E. faecalis, E. faecium y E. durans. La especie dominante fue L. plantarum. Las levaduras aisladas (32 de todas las muestras fueron identificadas como Saccharomyces cerevisiae o Candida parapsilosis. También se recoge en este estudio que las

  15. Endophytic Bacteria from Pinus taeda L. as Biocontrol Agents of Fusarium circinatum Nirenberg & O'Donnell Bacterias Endófitas de Pinus taeda L. como Agentes de control Biológico de Fusarium circinatum Nirenberg & O'Donnell

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    Silvina Soria

    2012-06-01

    Full Text Available Fusarium circinatum Nirenberg & O'Donnell, the pitch canker fungus, has been recently reported in Uruguay affecting Pinus taeda L. seedlings. The spread of this pathogen to plantations constitute a risk to forestry production. The aim of this work was to evaluate the inhibitory effect of live bacteria and their thermostable metabolites on F. circinatum growth in vitro. Four Bacillus subtilis strains and one of Burkholderia sp. isolated as P. taeda endophytes were evaluated as biological control agents of F. circinatum. Dual cultures between live bacteria and pathogen were performed. Furthermore, bacteria metabolites obtained from liquid cultures were sterilized and added to the culture media where fungus was grown. In this study all bacteria showed an antagonist effect on the pathogen growth arresting the mycelia at one cm of the edge of the bacteria colony. Bacteria thermostable metabolites reduced over 50% fungal growth. These results demonstrates that endophytic bacteria, well adapted to live in host tissues, constitute a good alternative to control F. circinatum affecting Pinus seedlings.La presencia de Fusarium circinatum Niremberg & O'Donnell, agente causal del cancro resinoso en pino, ha sido detectada recientemente en plántulas de Pinus taeda L. en Uruguay. La propagación de este patógeno en las plantaciones constituye un riesgo para la producción forestal. El objetivo de este trabajo fue determinar la capacidad inhibitoria de bacterias vivas y de sus metabolitos termoestables sobre el crecimiento de F. circinatum in vitro. Cuatro cepas de Bacillus subtilis y una de Burkholderia sp. aisladas como endófitas de P. taeda, fueron evaluadas como potenciales agentes de control biológico sobre F. circinatum. Para ello, se realizaron enfrentamientos directos entre las bacterias vivas y el micelio del patógeno. Por otra parte, los metabolitos bacterianos obtenidos de cultivos líquidos fueron esterilizados en autoclave y se incorporaron al

  16. Identificación, biotipificación y caracterización de cepas de Pasteurella multocida aisladas en la Argentina Identification, biotypification and characterization of Pasteurella multocida strains isolated in Argentina

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    G. A. Leotta

    2006-09-01

    Full Text Available Treinta cepas de Pasteurella multocida aisladas en la Argentina a partir de muestras de origen humano y animal fueron identificadas, biotipificadas y caracterizadas. Veintidós de ellas (73% correspondieron a P. multocida subsp. multocida; cinco (17% a P. multocida subsp. gallicida y tres (10% a P. multocida subsp. septica. Todas las cepas fueron agrupadas en 8 biotipos; el 70% presentó el tipo capsular A. Los serotipos somáticos más frecuentes fueron el 1 (n:11 y el 3 (n:9. Las cepas de origen porcino fueron resistentes a tiamulina, estreptomicina y tetraciclina. La caracterización de las cepas de P. multocida aisladas en la Argentina es el primer paso para concretar futuros estudios destinados a la prevención y al tratamiento de la pasteurelosis en medicina humana y veterinaria.Thirty Pasteurella multocida strains isolated in Argentina from human and animal samples were identified, biotypified and characterized. Twenty-two (73% strains were identified as P. multocida subsp. multocida, 5 (17% as P. multocida subsp. gallicida, and 3 (10% as P. multocida subsp. septica. All strains were grouped in 8 biotypes, and 70% of the strains presented capsular type A. The most frequent somatic serotypes were 1 (n:11 and 3 (n:9. P. multocida strains from swine source were resistant to tiamulin, streptomycin and tetracycline. Characterization of P. multocida strains isolated in Argentina is the first step to conduct future studies intended for the prevention and treatment of pasteurellosis in human and veterinary medicine.

  17. Supervivencia con oclusión traqueal fetoscópica versus manejo expectante post natal en el tratamiento de la hipoplasia pulmonar secundaria a hernia diafragmática congénita aislada

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    Rubén Darío Aguirre Urrea

    2014-09-01

    Full Text Available Antecedentes: La Hernia Diafragmática Congénita es el defecto más común de la formación y cierre del diafragma que permite el paso de las vísceras abdominales a la cavidad torácica generando dos consecuencias graves que aumentan el riesgo de mortalidad de los neonatos: hipoplasia e hipertensión pulmonar del lado afectado que determinan la gravedad de la anomalía. Objetivo: Comparar la supervivencia en los pacientes con hipoplasia pulmonar secundaria a Hernia Diafragmática Congénita aislada tratados con Oclusión Traqueal Fetoscópica versus la supervivencia en los tratados con manejo expectante post natal. Método: Se realizó una revisión integradora de la literatura científica de las bases de datos LILACS, SciELO, Cochrane Library, PubMed y Google Académico. Resultados: Se seleccionaron para ser analizados 11 estudios, entre los cuales, 6 fueron realizados en Europa: Inglaterra, Bélgica y España; 3 en Colombia, 1 en Brasil y 1 en Estados Unidos entre 1990 y 2013. Conclusiones: El pronóstico y las probabilidades de supervivencia mejoran sustancialmente cuando se opta por la Oclusión Traqueal Fetoscópica como tratamiento de la hipoplasia pulmonar secundaria a hernia diafragmática congénita aislada. Palabras clave: Hernia diafragmática congénita; oclusión traqueal fetoscópica; hipoplasia pulmonar, cirugía fetal, anomalías congénitas.

  18. How honey kills bacteria

    NARCIS (Netherlands)

    Kwakman, Paulus H. S.; te Velde, Anje A.; de Boer, Leonie; Speijer, Dave; Vandenbroucke-Grauls, Christina M. J. E.; Zaat, Sebastian A. J.

    2010-01-01

    With the rise in prevalence of antibiotic-resistant bacteria, honey is increasingly valued for its antibacterial activity. To characterize all bactericidal factors in a medical-grade honey, we used a novel approach of successive neutralization of individual honey bactericidal factors. All bacteria

  19. Análisis de predictores independientes del flujo del bypass coronario en pacientes intervenidos de revascularización miocárdica aislada

    Directory of Open Access Journals (Sweden)

    Stefano Urso

    2017-11-01

    Full Text Available Resumen: Introducción y objetivo: El medidor de flujo permite conocer 2 parámetros: el flujo medio del bypass coronario y el índice de pulsatilidad. Estos 2 parámetros, cuando están alterados, pueden indicar una estenosis de la anastomosis del bypass distal. Factores distintos de la suficiencia de la anastomosis, como la calidad de lecho coronario, pueden condicionar el flujo del bypass y dificultar su interpretación. El objetivo de nuestro estudio es analizar los predictores independientes del flujo de los bypass aorto-coronarios. Métodos: Recogimos de forma retrospectiva una serie consecutiva de 90 pacientes intervenidos de revascularización miocárdica aislada por el mismo cirujano desde enero del 2014 hasta agosto del 2016. A partir de esta serie, elaboramos una base de datos electrónica donde cada registro correspondía a un injerto. Construimos, por lo tanto, una base de datos de 185 injertos. De estos, 8 injertos no fueron analizados por no haberse medido el flujo correctamente. Por los tanto, los valores de flujo y de índice de pulsatilidad de 177 injertos fueron utilizados para nuestro análisis estadístico. Resultados: El análisis de regresión lineal múltiple detectó 2 predictores independientes del flujo de los bypasses: injerto de vena safena secuencial (valor r parcial: 0,32; p < 0,0001 e injerto arterial (valor r parcial: –0,23; p 0,0021. Por lo tanto, nuestro modelo objetivó una correlación directa entre la utilización de injerto de safena con técnica secuencial y flujo del bypass, y una correlación inversa entre la utilización de injerto arterial y flujo del bypass. Conclusiones: Los predictores del flujo de los bypasses aorto-coronarios son la utilización de un injerto arterial (coeficiente negativo y la utilización de un injerto venoso secuencial (coeficiente positivo. Nuestro modelo estadístico no ha identificado como predictor el SYNTAX score

  20. Resistencia inducida a la enfermedad del añublo de la panícula del arroz inoculando bacterias endofíticas

    Directory of Open Access Journals (Sweden)

    Manuel José Peláez Pelaez

    2017-09-01

    Full Text Available Se evaluó el efecto antagónico de las bacterias endófitas aisladas de porciones de hojas, tallos y raíces de plantas de arroz completamente sanas, contra la bacteria patogénica Burkholderia glumae (Kurita & Tabei, 1967, agente causal   de la enfermedad del añublo bacterial de la panícula. Se obtuvieron 24 aislamientos en total de bacterias endófitas que fueron evaluadas mediante la técnica de enfrentamiento de cultivos duales, en condiciones de laboratorio, posteriormente se realizaron las inoculaciones de la solución bacteriana en condiciones de campo para evaluar el efecto antagónico. Los resultados obtenidos indican que sólo dos cepas bacterianas presentaron actividad antagónica contra B. glumae las cuales fueron identificadas mediante caracterización bioquímica, de los bioensayos realizados a nivel de laboratorio y en campo. Por tanto, hubo una mejor expresión de las bacterias antagónicas bajo condiciones controladas en el laboratorio comparado con los ensayos realizados en campo

  1. Antibiotics from predatory bacteria

    Directory of Open Access Journals (Sweden)

    Juliane Korp

    2016-03-01

    Full Text Available Bacteria, which prey on other microorganisms, are commonly found in the environment. While some of these organisms act as solitary hunters, others band together in large consortia before they attack their prey. Anecdotal reports suggest that bacteria practicing such a wolfpack strategy utilize antibiotics as predatory weapons. Consistent with this hypothesis, genome sequencing revealed that these micropredators possess impressive capacities for natural product biosynthesis. Here, we will present the results from recent chemical investigations of this bacterial group, compare the biosynthetic potential with that of non-predatory bacteria and discuss the link between predation and secondary metabolism.

  2. Hydrogen production by nonphotosynthetic bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Huang, S.D.; Secor, C.K.; Zweig, R.M.; Ascione, R.

    1984-01-01

    H-producing nonphotosynthetic bacteria are identified and H from sewage treatment plants, H from rumen bacteria, and large-scale production of H through the genetic manipulation of H-producing nonphotosynthetic bacteria are discussed. (Refs. 36).

  3. [Darwin and bacteria].

    Science.gov (United States)

    Ledermann D, Walter

    2009-02-01

    As in 2009 the scientific world celebrates two hundreds years from the birthday of Charles Darwin and one hundred and fifty from the publication of The Origin of Species, an analysis of his complete work is performed, looking for any mention of bacteria. But it seems that the great naturahst never took knowledge about its existence, something rather improbable in a time when the discovery of bacteria shook the medical world, or he deliberately ignored them, not finding a place for such microscopic beings into his theory of evolution. But the bacteria badly affected his familiar life, killing scarlet fever one of his children and worsening to death the evolution of tuberculosis of his favourite Annie. Darwin himself could suffer the sickness of Chagas, whose etiological agent has a similar level to bacteria in the scale of evolution.

  4. Extracellular communication in bacteria

    DEFF Research Database (Denmark)

    Chhabra, S.R.; Philipp, B.; Eberl, L.

    2005-01-01

    molecules, in different Gram-positive and Gram-negative bacteria they control pathogenicity, secondary metabolite production, biofilm differentiation, DNA transfer and bioluminescence. The development of biosensors for the detection of these signal molecules has greatly facilitated their subsequent chemical...

  5. CARACTERIZACIÓN PRELIMINAR DE COMPUESTOS ANTILISTERIALES PRODUCIDOS POR BACTERIAS ÁCIDO LÁCTICAS NATIVAS

    Directory of Open Access Journals (Sweden)

    Blanca Botina A

    2008-12-01

    Full Text Available Objetivo. Caracterizar los metabolitos producidos por bacterias ácido lácticas nativas con capacidad antilisterial. Materiales y métodos. Se analizaron 42 muestras tomadas de alimentos y equipos procesadores de alimentos, de donde se aislaron bacterias ácido lácticas, las cuales se identificaron por medio de pruebas bioquímicas. Se evaluó la actividad antagónica de las cepas aisladas frente a 17 cepas de L. monocytogenes pertenecientes a los serotipos 4b, 4e, y 3b utilizando la técnica de la gota y doble capa. Se obtuvieron extractos crudos para la caracterización de los metabolitos inhibitorios del crecimiento de las cepas de L. monocytogenes, los cuales fueron tratados con catalasa, ácido clorhídrico, proteinasa K y temperaturas de 95ºC y 121ºC. El peso molecular de las proteínas se aproximó utilizando la técnica de electroforesis SDS-PAGE y bioensayos. Resultados. De un total de 250 aislamientos se lograron identificar 75 cepas de bacterias ácido lácticas. La evaluación de la actividad antagónica indicó que los metabolitos inhibitorios producidos por las bacterias ácido lácticas no actuaban de igual manera frente a las diferentes cepas de L. monocytogenes. Sin embargo, se encontró que tres de los aislamientos nativos identificados como Lactobacillus spp., Leuconostoc spp. y Enterococcus spp. presentaban una mejor actividad antilisterial debido a que sintetizan proteínas o metabolitos de peso molecular menor a 7600 Da. Conclusiones. En los alimentos distribuidos en Colombia existen cepas de bacterias ácido lácticas con potencial bioprotector.

  6. The fecal bacteria

    Science.gov (United States)

    Sadowsky, Michael J.; Whitman, Richard L.

    2011-01-01

    The Fecal Bacteria offers a balanced, integrated discussion of fecal bacteria and their presence and ecology in the intestinal tract of mammals, in the environment, and in the food supply. This volume covers their use in examining and assessing water quality in order to offer protection from illnesses related to swimming in or ingesting contaminated water, in addition to discussing their use in engineering considerations of water quality, modeling, monitoring, and regulations. Fecal bacteria are additionally used as indicators of contamination of ready-to-eat foods and fresh produce. The intestinal environment, the microbial community structure of the gut microbiota, and the physiology and genomics of this broad group of microorganisms are explored in the book. With contributions from an internationally recognized group of experts, the book integrates medicine, public health, environmental, and microbiological topics in order to provide a unique, holistic understanding of fecal bacteria. Moreover, it shows how the latest basic science and applied research findings are helping to solve problems and develop effective management strategies. For example, readers will discover how the latest tools and molecular approaches have led to our current understanding of fecal bacteria and enabled us to improve human health and water quality. The Fecal Bacteria is recommended for microbiologists, clinicians, animal scientists, engineers, environmental scientists, food safety experts, water quality managers, and students. It will help them better understand fecal bacteria and use their knowledge to protect human and environmental health. They can also apply many of the techniques and molecular tools discussed in this book to the study of a broad range of microorganisms in a variety of habitats.

  7. Caracterización de la comunidad bacteriana aerobia en sanguijuelas (Hirudinea, Haementeria sp. (Glossiphoniidae y Oxytychus ornatus (Macrobdellidae de El Bagre, Antioquia = Characterization of the aerobic bacterial community in leeches Haementeria sp (Hirudinea: Glossiphoniidae y Oxytychus ornatus (Hirudinea: Macrobdellidae de El Bagre, Antioquia

    Directory of Open Access Journals (Sweden)

    López Isaza, Laura Patricia

    2012-01-01

    Full Text Available Se ha incrementado el uso terapéutico de las sanguijuelas y se ha demostrado que ellas pueden inocular bacterias causantes de infecciones en el 20% de los pacientes. El hallazgo en Antioquia de dos especies de sanguijuelas promisorias para hirudoterapia motivó este estudio para identificar las bacterias en la superficie, la probóscide y el intestino de estos anélidos y evaluar su sensibilidad a antibióticos. Las sanguijuelas estudiadas se identificaron como Haementeria sp., y Oxytychus ornatus. Muestras de la superficie, boca e intestino de ambos anélidos se inocularon en agar sangre, agar sangre con ampicilina y agar eosina azul de metileno. La identificación de las bacterias y su sensibilidad a antibióticos se evaluaron por el método automatizado Vitek (Biomerieux®. Se hicieron en total 26 aislamientos pertenecientes a 12 especies de nueve géneros. Enterobacter cloacae fue la especie más frecuente en ambos anélidos. Las bacterias fueron sensibles a los antibióticos comúnmente empleados en las infecciones causadas por este tipo de microorganismos. Se sugiere hacer profilaxis con antibióticos en los pacientes que reciban terapia con los anélidos investigados e implementar los protocolos estandarizados para el lavado de los animales antes de su uso y para el aseo de los acuarios en donde se los mantenga.

  8. Evaluación de la susceptibilidad antimicrobiana de cepas de Salmonella spp. aisladas del beneficio porcino en Colombia / Evaluation of antimicrobial susceptibility of Salmonella spp. strains isolated from pork carcasses on Colombia

    Directory of Open Access Journals (Sweden)

    Paula M. Bermúdez D

    2014-01-01

    Full Text Available Objetivo: el estudio buscó establecer patrones de resistencia antimicrobiana de 155 cepas de Salmonella spp., aisladas de la superficie de canales de cerdo, procedentes de plantas de beneficio en Colombia. Metodología: mediante el método de difusión en disco (Bauer et. Kirby, 1966 se evaluaron nueve antimicrobianos: Amoxicilina y ácido clavulánico (30 ug, Ampicilina (10 ug, Ceftiofur (30 ug, Ciprofloxacina (5 ug, Cloranfenicol (30 ug, Florfenicol (30 ug, Gentamicina (10 ug, Sulfadiazina y Trimetoprim (25 ug y Tetraciclina (30 ug. Resultados: los resultados confirmaron la presencia de cepas multiresistentes de Salmonella spp. de origen porcino, mostrando 30 patrones diferentes de multiresistencia; el más común fue Ampicilina, Amoxicilina, Cloranfenicol, Florfenicol y Tetraciclina en el 16,77% (n=26 de las cepas. Tetraciclina y Florfenicol fueron los antimicrobianos menos efectivos en el 94,84% (n=147 y 47,74% (n=74 de cepas resistentes, respectivamente. Discusión: se deben consolidar los sistemas de monitoreo, y de vigilancia y control de las resistencias antimicrobianas para prevenir, con un enfoque de cadena productiva, la diseminación de cepas multiresistentes en alimentos de origen animal, como parte integral del sistema de gestión de inocuidad de los alimentos en Colombia. - Objetivo: el estudio buscó establecer patrones de resistencia antimicrobiana de 155 cepas de Salmonella spp., aisladas de la superficie de canales de cerdo, procedentes de plantas de beneficio en Colombia. Metodología: mediante el método de difusión en disco (Bauer et. Kirby, 1966 se evaluaron nueve antimicrobianos: Amoxicilina y ácido clavulánico (30 ug, Ampicilina (10 ug, Ceftiofur (30 ug, Ciprofloxacina (5 ug, Cloranfenicol (30 ug, Florfenicol (30 ug, Gentamicina (10 ug, Sulfadiazina y Trimetoprim (25 ug y Tetraciclina (30 ug. Resultados: los resultados confirmaron la presencia de cepas multiresistentes de Salmonella spp. de origen porcino, mostrando

  9. Linear Alkylbenzene Sulfonate tolerance in bacteria isolated from sediment of tropical water bodies polluted with detergents

    Directory of Open Access Journals (Sweden)

    I.T Kehinde

    2008-12-01

    ambiente acuático. El tensoactivador persiste en algunos arroyos y ríos de Nigeria, en parte es absorbido por materiales en suspensión y termina entre los sedimentos de los cuerpos de agua receptores. En este estudio, bacterias aisladas de los sedimentos de algunos arroyos tropicales que reciben efluentes contaminados con detergentes, fueron analizadas para determinar su tolerancia a los LAS, utilizando la técnica de dilusión del medio. Las bacterias se consideraron tolerantes a los LAS cuando continuaron creciendo aún en presencia del tensoactivador. En los sedimentos también se determinó acidez (pH, concentración de tensoactivador, poblaciones de bacterias heterotróficas y de bacterias tolerantes a los LAS. Se encontró una relación directa (r= 0.9124 entre condiciones alcalinas (pH= 8.2-12.0 y concentraciones altas de tensoactivador (45-132 mg/g en los sedimentos. Además, los sedimentos mostraron albergar a una población grande y variada de bacterias; las poblaciones de bacterias heterotróficas (vHB: 2.9×10(5 -1.2×10(7 cfu/g y bacterias tolerantes a los LAS (LTB: 1.5×10(4 -1.2×10(6 cfu/g, mostraron una relación directa (r= 0.9500. Por otra parte, una relación inversa se encontró entre cada una de ellas y la concentración de tensoactivador en los sedimentos, r vHB/ LAS = -0.9303 y rLTB/ LAS = -0.9143 respectivamente. Doce especies de bacterias fueron aisladas de los sedimentos: Alcaligenes odorans, Bacillus subtilis, Burkholderia cepacia, Citrobacter freundii, Citrobacter diversus, Escherichia coli, Micrococcus luteus, Micrococcus albus, Pseudomonas putida, Pseudomonas stutzeri, Staphylococcus aureus y Streptococcus faecalis. La mayoría de esas especies muestra adaptaciones al tensoactividor, siempre que éste se encuentre en concentraciones entre 0.03 y 1.0% (w/v. Los sedimentos pueden servir como una fuente de organismos que pueden ser utilizados en el bio-tratamiento de desechos que contengan LAS.

  10. Mycorrhiza helper bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Deveau, Aurelie [French National Insitute for Agricultural Research (INRA); Labbe, Jessy [ORNL

    2016-10-01

    This chapter focuses on the Mycorrhiza Helper Bacteria (MHB), a generic name given to bacteria which stimulate the formation of mycorrhizal symbiosis. By extension, some bacterial strains that positively impact the functioning of mycorrhizal symbiosis are also called MHB. These bacteria have applicative interests, as they indirectly improve the health and growth of tree seedlings. MHB are not restricted to a specific type of ecosystem, but are rather generalist in the way that they associate with both herbaceous and woody mycorrhizal plants from boreal, temperate, arid and tropical ecosystems. However, understanding the molecular mechanisms and their specificities will help us to know more about the ecology of the MHB. The process of acquisition varies between fungal species; while ectomycorrhizal fungi most probably recurrently acquire them from the environment, the association between bacterial endosymbionts and Glomeromycota probably dates back to very ancient times, and has since been vertically transmitted.

  11. Antifreeze Proteins of Bacteria

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 12; Issue 12. Antifreeze Proteins of Bacteria. M K Chattopadhyay. General Article Volume 12 Issue 12 December 2007 pp 25-30. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/012/12/0025-0030 ...

  12. (PHB)-producing bacteria

    African Journals Online (AJOL)

    Jane

    2011-06-06

    Jun 6, 2011 ... Bioplastics are naturally occurring biodegradable polymers made from polyhydroxyalkanoates (PHA) of which poly 3-hydroxy butyric acid ... The plastic polymers accumulate intracellularly as light- refracting amorphous ... study focuses on the isolation and identification of novel species of bacteria capable ...

  13. Do Bacteria Age?

    Indian Academy of Sciences (India)

    Bacteria are thought to be examples of organisms that do not age. ... sues, organs, organ systems, organism, population, species, and .... Humans inevitably grow old through aging. All vertebrates show physical manifestations of aging somewhat similar to humans (other than white hair!). Aging is also seen in plants.

  14. Antifreeze Proteins of Bacteria

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 12; Issue 12. Antifreeze Proteins of Bacteria. M K Chattopadhyay. General Article Volume 12 Issue 12 December 2007 pp 25-30. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/012/12/0025-0030. Keywords.

  15. Antibiotic-Resistant Bacteria.

    Science.gov (United States)

    Longenecker, Nevin E.; Oppenheimer, Dan

    1982-01-01

    A study conducted by high school advanced bacteriology students appears to confirm the hypothesis that the incremental administration of antibiotics on several species of bacteria (Escherichia coli, Staphylococcus epidermis, Bacillus sublitus, Bacillus megaterium) will allow for the development of antibiotic-resistant strains. (PEB)

  16. (PHB)-producing bacteria

    African Journals Online (AJOL)

    Isolation and characterization of two novel polyhydroxybutyrate (PHB)-producing bacteria. ... subsequently studied using phenotype microarray panels which allowed the testing of the effect of more than 90 different carbon, nitrogen, sulfur and phosphorus sources as well as pH on the growth characteristics of these strains.

  17. Selection of oleuropein-degrading lactic acid bacteria strains isolated from fermenting Moroccan green olives

    Directory of Open Access Journals (Sweden)

    Ghabbour, N.

    2011-03-01

    Full Text Available A total of 177 strains of lactic acid bacteria (LAB were isolated from early-stage Moroccan Picholine green olive fermentation, including Lactobacillus plantarum (44.63%, Lactobacillus pentosus (25.99%, Lactobacillus brevis (9.61% and Pediococcus pentosaceus (19.77%. All the isolates were screened for their tolerance to olive leaf extract and oleuropein. Most of the isolates (85.3% were found able to degrade oleuropein, when evaluated by either oleuropein or 5-Bromo- 4-chloro-3-indolyl β-D-glucuronide (X-Gluc as substrates. The biodegradation capacity of the selected strains of each species was confirmed by HPLC analysis.

    Un total de 177 cepas de bacterias ácido lácticas (LAB fueron aisladas en las primeras etapas de la fermentación de aceitunas verdes marroquíes Picholine, incluyendo Lactobacillus plantarum (44.63%, Lactobacillus pentosus (25.99%, Lactobacillus brevis (9.61% y Pediococcus pentosaceus (19.77%. Todos los aislados fueron evaluados mediante su tolerancia a extractos de hojas de olivo y oleuropeína. La mayoría de los aislados (85,3% degradaron oleuropeína, cuando fueron evaluados usando oleuropeína o 5-Bromo-4-cloro- 3-indolil β-D-glucuronido (X-Gluc como sustrato. La capacidad de biodegradación de las cepas seleccionadas para cada especie fue confirmada mediante análisis por HPLC.

  18. The friendly bacteria within us Commensal bacteria of the intestine ...

    Indian Academy of Sciences (India)

    The friendly bacteria within us Commensal bacteria of the intestine: Roles in health and disease B.S. Ramakrishna Professor & Head Gastroenterology & Hepatology Christian Medical College Vellore · Slide 2 · Intestinal bacteria: the hidden organ · Slide 4 · Slide 5 · The normal bacterial flora prevents GI disease · Slide 7.

  19. The friendly bacteria within us Commensal bacteria of the intestine ...

    Indian Academy of Sciences (India)

    Short chain fatty acids (SCFA) are main source of energy for colonic epithelial cells · SCFA – role in colonic disease · SCFA prevent mucosal inflammation · Immunoregulation by gut bacteria · Balance of bacterial species in the gut · Immunosensory detection of intestinal bacteria · Pathogenic bacteria release interleukin-8 ...

  20. Manufacture of Probiotic Bacteria

    Science.gov (United States)

    Muller, J. A.; Ross, R. P.; Fitzgerald, G. F.; Stanton, C.

    Lactic acid bacteria (LAB) have been used for many years as natural biopreservatives in fermented foods. A small group of LAB are also believed to have beneficial health effects on the host, so called probiotic bacteria. Probiotics have emerged from the niche industry from Asia into European and American markets. Functional foods are one of the fastest growing markets today, with estimated growth to 20 billion dollars worldwide by 2010 (GIA, 2008). The increasing demand for probiotics and the new food markets where probiotics are introduced, challenges the industry to produce high quantities of probiotic cultures in a viable and stable form. Dried concentrated probiotic cultures are the most convenient form for incorporation into functional foods, given the ease of storage, handling and transport, especially for shelf-stable functional products. This chapter will discuss various aspects of the challenges associated with the manufacturing of probiotic cultures.

  1. Bacteria in ulcera crurum.

    Science.gov (United States)

    Kontiainen, S; Rinne, E

    1988-01-01

    Bacterial cultures derived from 432 chronic leg ulcers were analysed retrospectively to determine which bacteria are most commonly found in these ulcers. The study covered a 2-year period. Two-thirds of the patients were over 70 years of age. Staphylococcus aureus was found in nearly half of the ulcers studied, Pseudomonas sp. in one-third, pyogenic streptococci and enterococci in every fifth and Proteus sp. in every tenth. The frequency by which pyogenic streptococci were isolated was about 10 to 20 times as high as previously reported. Obligate anaerobic bacteria were also frequently isolated. The sensitivity of the isolates from the second year to antimicrobial agents likely to be chosen if systemic therapy were required is also reported. The results are discussed in relation to previous findings.

  2. Bacteria in ancient sediments

    International Nuclear Information System (INIS)

    Izzo, G.

    1986-01-01

    In order to ascertain the role of biological activity in ancient sediments, two microbiological studies were carried out. The first was on pleistocenic clay sediments on land, the second on deep oceanic sediments. In the present paper by direct counting the samples is demonstrated the presence of bacteria in a range of 10 5 to 10 7 . Further studies must be carried out to ascertain the activities by in situ incubation methods

  3. Bacteria colonizing paper machines

    OpenAIRE

    Ekman, Jaakko

    2011-01-01

    Bacteria growing in paper machines can cause several problems. Biofilms detaching from paper machine surfaces may lead to holes and spots in the end product or even break the paper web leading to expensive delays in production. Heat stable endospores will remain viable through the drying section of paper machine, increasing the microbial contamination of paper and board. Of the bacterial species regularly found in the end products, Bacillus cereus is the only one classified as a pathogen. Cer...

  4. Pepsin homologues in bacteria

    Directory of Open Access Journals (Sweden)

    Bateman Alex

    2009-09-01

    Full Text Available Abstract Background Peptidase family A1, to which pepsin belongs, had been assumed to be restricted to eukaryotes. The tertiary structure of pepsin shows two lobes with similar folds and it has been suggested that the gene has arisen from an ancient duplication and fusion event. The only sequence similarity between the lobes is restricted to the motif around the active site aspartate and a hydrophobic-hydrophobic-Gly motif. Together, these contribute to an essential structural feature known as a psi-loop. There is one such psi-loop in each lobe, and so each lobe presents an active Asp. The human immunodeficiency virus peptidase, retropepsin, from peptidase family A2 also has a similar fold but consists of one lobe only and has to dimerize to be active. All known members of family A1 show the bilobed structure, but it is unclear if the ancestor of family A1 was similar to an A2 peptidase, or if the ancestral retropepsin was derived from a half-pepsin gene. The presence of a pepsin homologue in a prokaryote might give insights into the evolution of the pepsin family. Results Homologues of the aspartic peptidase pepsin have been found in the completed genomic sequences from seven species of bacteria. The bacterial homologues, unlike those from eukaryotes, do not possess signal peptides, and would therefore be intracellular acting at neutral pH. The bacterial homologues have Thr218 replaced by Asp, a change which in renin has been shown to confer activity at neutral pH. No pepsin homologues could be detected in any archaean genome. Conclusion The peptidase family A1 is found in some species of bacteria as well as eukaryotes. The bacterial homologues fall into two groups, one from oceanic bacteria and one from plant symbionts. The bacterial homologues are all predicted to be intracellular proteins, unlike the eukaryotic enzymes. The bacterial homologues are bilobed like pepsin, implying that if no horizontal gene transfer has occurred the duplication

  5. Serotypes and susceptibility of Streptococcus pneumoniae strains isolated from children in Mexico Serotipos y susceptibilidad de cepas de Streptococcus pneumoniae aisladas de niños en México

    Directory of Open Access Journals (Sweden)

    Alberto Villaseñor-Sierra

    2008-08-01

    Full Text Available Objective. To identify serotypes and susceptibility of S. pneumoniae strains from 48 children with invasive infections and 50 carriers. Material and Methods. Typing was performed by the Quellung reaction and susceptibility by Kirby-Bauer and Etest according to CLSI standards. Results. Of 31 meningeal strains, serotypes 19F, 3, 6B, 14 and 23F were predominant. Resistance to penicillin and STX was 16 and 58%, respectively; of 17 invasive non-meningeal strains, serotypes 19F and 3 were predominant and resistance to penicillin and SXT was 0 and 82%, respectively; of carrier strains, serotypes 6A, 6B, 19F and 23F were predominant. Conclusions. A 10-valent conjugate vaccine could offer a better coverage for meningeal strains.Objetivo. Identificar serotipos y susceptibilidad en cepas aisladas de 48 niños con infecciones invasivas y de 50 portadores. Material y métodos. Serotipificación mediante reacción de Quellung y susceptibilidad mediante Kirby-Bauer y E-test. Resultados. De 31 cepas meníngeas, predominaron serotipos 19F, 3, 6B, 14 y 23F y la resistencia a penicilina (P y trimetoprim-sulfametoxazol (SXT fue de 16 y 58%. En 17 cepas invasivas no meníngeas, predominaron serotipos 19F y 3 y la resistencia a P y SXT fue de 0 y 82%, en cada caso. En portadores predominaron serotipos 6A, 6B, 19F y 23F. Conclusiones. La resistencia es similar a otros informes. La vacuna conjugada 10-valente podría ofrecer mejor cobertura para serotipos asociados a meningitis.

  6. Determinación de las condiciones de crecimiento in vitro de una cepa probiótica (Lactobacillus delbruekii subsp. bulgaricus aislada del tracto intestinal de terneros (Bos taurus

    Directory of Open Access Journals (Sweden)

    José Ávila

    2010-07-01

    Full Text Available El objetivo de este estudio fue conocer el efecto de la temperatura, pH y la concentración de inóculo sobre el crecimiento in vitro de una cepa probiótica (Lactobacillus delbruekii subsp. bulgaricus aislada del intestino delgado de terneros. Para ello se utilizó en el primer caso, el método de superficie de respuesta para determinar las condiciones de pH y temperatura óptimas de la cepa, y en el segundo, un diseño experimental completamente aleatorizado considerando el factor concentración de inóculo inicial a seis niveles, donde el crecimiento (en medio De Man, Rogosa y Sharpe expresado en unidades de Absorbancia, constituyó la variable respuesta; presentándose una máxima respuesta (0,806 uA para 5 % de concentración inicial de inóculo. Los valores de pH y temperatura utilizados permitieron el establecimiento de una zona óptima de crecimiento in vitro en los siguientes intervalos, pH entre 5,1 y 5,6; y temperatura entre 38,0 y 41,5 °C, donde el máximo crecimiento se obtuvo a pH 5,31 y a 39,38 °C. Por otro lado se encontraron incrementos significativos del crecimiento in vitro (p < 0,05 a medida que se utiliza menor concentración de inóculo inicial. Con la información obtenida se espera incrementar los rendimientos de la cepa y así promover la producción de productos probióticos para el consumo animal en Venezuela.

  7. Determinación de las condiciones de crecimiento in vitro de una cepa probiótica (Lactobacillus delbruekii subsp. bulgaricus aislada del tracto intestinal de terneros (Bos taurus

    Directory of Open Access Journals (Sweden)

    José Ávila

    2010-06-01

    Full Text Available El objetivo de este estudio fue conocer el efecto de la temperatura, pH y la concentración de inóculo sobre el crecimiento in vitro de una cepa probiótica (Lactobacillus delbruekii subsp. bulgaricus aislada del intestino delgado de terneros. Para ello se utilizó en el primer caso, el método de superficie de respuesta para determinar las condiciones de pH y temperatura óptimas de la cepa, y en el segundo, un diseño experimental completamente aleatorizado considerando el factor concentración de inóculo inicial a seis niveles, donde el crecimiento (en medio De Man, Rogosa y Sharpe expresado en unidades de Absorbancia, constituyó la variable respuesta; presentándose una máxima respuesta (0,806 uA para 5 % de concentración inicial de inóculo. Los valores de pH y temperatura utilizados permitieron el establecimiento de una zona óptima de crecimiento in vitroen los siguientes intervalos, pH entre 5,1 y 5,6; y temperatura entre 38,0 y 41,5 °C, donde el máximo crecimiento se obtuvo a pH 5,31 y a 39,38 °C. Por otro lado se encontraron incrementos significativos del crecimiento in vitro (p < 0,05 a medida que se utiliza menor concentración de inóculo inicial. Con la información obtenida se espera incrementar los rendimientos de la cepa y así promover la producción de productos probióticos para el consumo animal en Venezuela.

  8. Una nueva especie de Euglena (Euglenozoa: Euglenales aislada de ambientes extremófilos en las Pailas de Barro del Volcán Rincón de la Vieja, Costa Rica

    Directory of Open Access Journals (Sweden)

    Ana Sittenfeld

    2004-03-01

    Full Text Available Se describe una nueva especie de euglena aislada de las Pailas de Barro Caliente del Volcán Rincón de la Vieja, Costa Rica. Esta especie se caracteriza por habitar sitios ácidos y calientes. Euglena pailasensis sp. nov. tiene como características principales: la ausencia de flagelos, presencia de filamentos similares a "pilis", presencia de cloroplastos con pirenoides atravesados por varios tilacoides, además, es termotolerante y acido-tolerante. Los análisis filogenéticos para el gen ADNr 18S y la secuencia del gen para la enzima Gap C indican que la nueva especie está relacionada con E. mutabilis. Las características taxonómicas basadas en la morfología, biología y secuencia del ADNr 18S y los genes GAP C, son discutidas y comparadas con otras especies relativamente cercanas al géneroAnew species of euglena isolated from a hot and acid mud pool located in Las Pailas de Barro, Volcán Rincón de la Vieja, Costa Rica is described. This species inhabits hot and acid environments. Euglena pailasensis sp. nov. main features are: the absence of flagella, the presence filaments like "pilis", the presence of chloroplasts with pyrenoids crossed by several tylakoids, and acid and heat tolerance. Molecular phylogeny studies using 18S rDNA and Gap C genes indicated that the new species is related to E mutabilis. Its taxonomic characters based on morphology, biology and sequence of the 18S rDNA and Gap C genes are discussed and compared with other closely related species of the genus

  9. Valoración de desinfectantes mediante el método dilución-neutralización en cepas de Salmonella spp. aisladas en plantas de beneficio porcino

    Directory of Open Access Journals (Sweden)

    Andrea Paola Rodríguez Triviño

    2011-06-01

    Full Text Available La salmonelosis es una enfermedad muy importante, causante de problemas de salud pública ya que produce fiebres entéricas, gastroenteritis, bacteriemia, infecciones localizadas y estado de portador crónico, además se han informado como fuentes de contaminación los huevos, las carnes y la leche, tres de los alimentos más importantes consumidos por las personas. Por tal razón es importante determinar en la industria de los alimentos la susceptibilidad de Salmonella spp. a los desinfectantes, con el fin de contribuir a elaborar programas de prevención y control de este microorganismo, haciéndose necesaria la evaluación de su acción en cepas de Salmonella spp., en especial sobre aquellas transmitidas por los alimentos, además se debe medir la eficacia de los tipos de desinfectantes mediante el ensayo cuantitativo de suspensión para la evaluación de la actividad bactericida, en especial cuando a futuro se tenga como objetivo, evaluar el uso de desinfectantes en cepas de Salmonella spp. aisladas de plantas de beneficio porcino. Así que una vez se seleccionen las plantas de beneficio porcino objeto de la medición, en éstas se debe aislar una cantidad representativa de cepas de Salmonella spp., para someterlas a los diversos tipos de desinfectantes. El objetivo de la presente revisión es comparar la eficacia de tipos de desinfectantes que cuentan con un principio activo de amonio cuaternario y ácido peracético. Esperando que en futuros ensayos, por el método a nivel in vitro se puede comprobar la eficacia de los mismos.

  10. Valoración de desinfectantes mediante el método dilución-neutralización en cepas de Salmonella spp. aisladas en plantas de beneficio porcino

    Directory of Open Access Journals (Sweden)

    Jairo Humberto López Vargas

    2011-01-01

    Full Text Available La salmonelosis es una enfermedad muy importante, causante de problemas de salud pública ya que produce fiebres entéricas, gastroenteritis, bacteriemia, infecciones localizadas y estado de portador crónico, además se han informado como fuentes de contaminación los huevos, las carnes y la leche, tres de los alimentos más importantes consumidos por las personas. Por tal razón es importante determinar en la industria de los alimentos la susceptibilidad de Salmonella spp. a los desinfectantes, con el fin de contribuir a elaborar programas de prevención y control de este microorganismo, haciéndose necesaria la evaluación de su acción en cepas de Salmonella spp., en especial sobre aquellas transmitidas por los alimentos, además se debe medir la eficacia de los tipos de desinfectantes mediante el ensayo cuantitativo de suspensión para la evaluación de la actividad bactericida, en especial cuando a futuro se tenga como objetivo, evaluar el uso de desinfectantes en cepas de Salmonella spp. aisladas de plantas de beneficio porcino. Así que una vez se seleccionen las plantas de beneficio porcino objeto de la medición, en éstas se debe aislar una cantidad representativa de cepas de Salmonella spp., para someterlas a los diversos tipos de desinfectantes. El objetivo de la presente revisión es comparar la eficacia de tipos de desinfectantes que cuentan con un principio activo de amonio cuaternario y ácido peracético. Esperando que en futuros ensayos, por el método a nivel in vitro se puede comprobar la eficacia de los mismos.

  11. Bacteria counting method based on polyaniline/bacteria thin film.

    Science.gov (United States)

    Zhihua, Li; Xuetao, Hu; Jiyong, Shi; Xiaobo, Zou; Xiaowei, Huang; Xucheng, Zhou; Tahir, Haroon Elrasheid; Holmes, Mel; Povey, Malcolm

    2016-07-15

    A simple and rapid bacteria counting method based on polyaniline (PANI)/bacteria thin film was proposed. Since the negative effects of immobilized bacteria on the deposition of PANI on glass carbon electrode (GCE), PANI/bacteria thin films containing decreased amount of PANI would be obtained when increasing the bacteria concentration. The prepared PANI/bacteria film was characterized with cyclic voltammetry (CV) technique to provide quantitative index for the determination of the bacteria count, and electrochemical impedance spectroscopy (EIS) was also performed to further investigate the difference in the PANI/bacteria films. Good linear relationship of the peak currents of the CVs and the log total count of bacteria (Bacillus subtilis) could be established using the equation Y=-30.413X+272.560 (R(2)=0.982) over the range of 5.3×10(4) to 5.3×10(8)CFUmL(-1), which also showed acceptable stability, reproducibility and switchable ability. The proposed method was feasible for simple and rapid counting of bacteria. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Diversidad de bacterias cultivables con capacidad de degradar hidrocarburos de la playa de Caleta Córdova, Argentina

    Directory of Open Access Journals (Sweden)

    Graciela N. Pucci

    2011-05-01

    Full Text Available En el presente trabajo se estudiaron las comunidades bacterianas aisladas de agua de mar y sedimentos intermareales de Caleta Córdova, norte de Comodoro Rivadavia, Argentina. Tres sitios fueron muestreados estacionalmente entre los años 2005 y 2006; el primer sitio fue una playa pública, el segundo sitio cerca de un puerto pesquero y el tercero cerca de una boya de toma de petróleo. Las comunidades bacterianas fueron determinadas en base a las diferencias en la composición de ácidos grasos de membrana, las bacterias fueron identificadas por medio del Sistema Sherlock MIDI, y el potencial de las comunidades para la utilización de hidrocarburos por la mineralización de gasoil, petróleo, kerosene, aceite lubricante y nafta. Las mineralizaciones evidenciaron la capacidad de los microorganismos para la degradación de hidrocarburos en dos de los sitios estudiados. Se aislaron 251 cepas de las que se lograron identificar 124 correspondientes a 24 géneros y 40 especies; la más frecuente fue Pseudoalteromonas.

  13. Beneficial bacteria inhibit cachexia

    Science.gov (United States)

    Varian, Bernard J.; Goureshetti, Sravya; Poutahidis, Theofilos; Lakritz, Jessica R.; Levkovich, Tatiana; Kwok, Caitlin; Teliousis, Konstantinos; Ibrahim, Yassin M.; Mirabal, Sheyla; Erdman, Susan E.

    2016-01-01

    Muscle wasting, known as cachexia, is a debilitating condition associated with chronic inflammation such as during cancer. Beneficial microbes have been shown to optimize systemic inflammatory tone during good health; however, interactions between microbes and host immunity in the context of cachexia are incompletely understood. Here we use mouse models to test roles for bacteria in muscle wasting syndromes. We find that feeding of a human commensal microbe, Lactobacillus reuteri, to mice is sufficient to lower systemic indices of inflammation and inhibit cachexia. Further, the microbial muscle-building phenomenon extends to normal aging as wild type animals exhibited increased growth hormone levels and up-regulation of transcription factor Forkhead Box N1 [FoxN1] associated with thymus gland retention and longevity. Interestingly, mice with a defective FoxN1 gene (athymic nude) fail to inhibit sarcopenia after L. reuteri therapy, indicating a FoxN1-mediated mechanism. In conclusion, symbiotic bacteria may serve to stimulate FoxN1 and thymic functions that regulate inflammation, offering possible alternatives for cachexia prevention and novel insights into roles for microbiota in mammalian ontogeny and phylogeny. PMID:26933816

  14. Chemical communication in bacteria

    Science.gov (United States)

    Suravajhala, Srinivasa Sandeep; Saini, Deepak; Nott, Prabhu

    Luminescence in Vibrio fischeri is a model for quorum-sensing-gene-regulation in bacteria. We study luminescence response of V. fischeri to both internal and external cues at the single cell and population level. Experiments with ES114, a wild-type strain, and ainS mutant show that luminescence induction in cultures is not always proportional to cell-density and there is always a basal level of luminescence. At any given concentration of the exogenously added signals, C6-HSL and C8-HSL, luminescence per cell reaches a maximum during the exponential phase and decreases thereafter. We hypothesize that (1) C6-HSL production and LuxR activity are not proportional to cell-density, and (2) there is a shift in equilibrium from C6-HSL to C8-HSL during the later stages of growth of the culture. RT-PCR analysis of luxI and luxR shows that the expression of these genes is maximum corresponding to the highest level of luminescence. The shift in equilibrium is shown by studying competitive binding of C6-HSL and C8-HSL to LuxR. We argue that luminescence is a unicellular behaviour, and an intensive property like per cell luminescence is more important than gross luminescence of the population in understanding response of bacteria to chemical signalling. Funding from the Department of Science and Technology, India is acknowledged.

  15. Susceptibility to rifaximin and other antimicrobials of bacteria isolated in patients with acute gastrointestinal infections in Southeast Mexico

    Directory of Open Access Journals (Sweden)

    O. Novoa-Farias

    2017-07-01

    Full Text Available Introduction: Enteropathogenic bacteria isolated in Mexico City have shown a high rate of resistance to different antibiotics, with the exception of rifaximin (RIF. RIF is a nonabsorbable antibiotic that reaches high fecal concentrations (≈ 8,000 μg/g. Susceptibility to antimicrobials can vary in different geographic regions. Aim: To study the susceptibility to rifaximin and other antimicrobials of enteropathogenic bacteria isolated in patients with acute diarrhea in the southeastern region of Mexico. Material and methods: A total of 614 strains of bacteria isolated from patients with acute diarrhea from 4 cities in Southeast Mexico were analyzed. An antibiogram with the following antibiotics was created: ampicillin (AMP, trimethoprim/sulfamethoxazole (T-S, neomycin (NEO, furazolidone (FUR, ciprofloxacin (CIP, chloramphenicol (CHL, and fosfomycin (FOS, assessed through the agar diffusion method at the standard concentrations recommended by the Clinical and Laboratory Standards Institute (CLSI and the American Society for Microbiology (ASM, and RIF, assessed through microdilution at 4 concentrations. Results: The bacteria were Escherichia coli (55%, as the majority, in all its pathogenic variants, Shigella (16.8%, Salmonella (15.3%, Aeromonas (7.8%, and less than 5% Campylobacter, Yersinia, Vibrio, and Plesiomonas. The accumulated overall susceptibility to RIF was 69.1, 90.8, 98.9, and 100% at concentrations of 100, 200, 400, and 800 μg/ml, respectively. Overall susceptibility to other antibiotics was FOS 82.8%, CHL 76.8%, CIP 73.9%, FUR 64%, T-S 58.7%, NEO 55.8%, and AMP 23.8%. Susceptibility to RIF at 400 and 800 μg was significantly greater than with the other antimicrobials (P 98% of the bacterial strains and a high frequency of resistance to several common antimicrobials. Resumen: Antecedentes: Bacterias enteropatógenas aisladas en la Ciudad de México han mostrado una alta tasa de resistencia a diversos antibi

  16. Cable Bacteria in Freshwater Sediments

    DEFF Research Database (Denmark)

    Risgaard-Petersen, Nils; Kristiansen, Michael; Frederiksen, Rasmus

    2015-01-01

    In marine sediments cathodic oxygen reduction at the sediment surface can be coupled to anodic sulfide oxidation in deeper anoxic layers through electrical currents mediated by filamentous, multicellular bacteria of the Desulfobulbaceae family, the so-called cable bacteria. Until now, cable...... bacteria have only been reported from marine environments. In this study, we demonstrate that cable bacteria also occur in freshwater sediments. In a first step, homogenized sediment collected from the freshwater stream Giber Å, Denmark, was incubated in the laboratory. After 2 weeks, pH signatures...... marine cable bacteria, with the genus Desulfobulbus as the closest cultured lineage. The results of the present study indicate that electric currents mediated by cable bacteria could be important for the biogeochemistry in many more environments than anticipated thus far and suggest a common evolutionary...

  17. Immunomodulatory properties of probiotic bacteria

    DEFF Research Database (Denmark)

    Fink, Lisbeth Nielsen

    2007-01-01

    Certain lactic acid bacteria (LAB) are part of the commensal intestinal flora and considered beneficial for health, as they compete with pathogens for adhesion sites in the intestine and ferment otherwise indigestible compounds. Another important property of these so-called probiotic bacteria...... with bacteria, and the cytokine pattern induced by specific bacteria resembled the pattern induced in MoDC, except for TNF-alpha and IL-6, which were induced in response to different bacteria in blood DC/monocytes and monocyte-derived DC. Autologous NK cells produced IFN-gamma when cultured with blood DC......, monocytes and monocyte-derived DC and IL-12-inducing bacteria, whereas only DC induced IFN-gamma production in allogeneic T cells. In vitro-generated DC is a commonly used model of tissue DC, but they differ in certain aspects from intestinal DC, which are in direct contact with the intestinal microbiota...

  18. Phenotypic switching in bacteria

    Science.gov (United States)

    Merrin, Jack

    Living matter is a non-equilibrium system in which many components work in parallel to perpetuate themselves through a fluctuating environment. Physiological states or functionalities revealed by a particular environment are called phenotypes. Transitions between phenotypes may occur either spontaneously or via interaction with the environment. Even in the same environment, genetically identical bacteria can exhibit different phenotypes of a continuous or discrete nature. In this thesis, we pursued three lines of investigation into discrete phenotypic heterogeneity in bacterial populations: the quantitative characterization of the so-called bacterial persistence, a theoretical model of phenotypic switching based on those measurements, and the design of artificial genetic networks which implement this model. Persistence is the phenotype of a subpopulation of bacteria with a reduced sensitivity to antibiotics. We developed a microfluidic apparatus, which allowed us to monitor the growth rates of individual cells while applying repeated cycles of antibiotic treatments. We were able to identify distinct phenotypes (normal and persistent) and characterize the stochastic transitions between them. We also found that phenotypic heterogeneity was present prior to any environmental cue such as antibiotic exposure. Motivated by the experiments with persisters, we formulated a theoretical model describing the dynamic behavior of several discrete phenotypes in a periodically varying environment. This theoretical framework allowed us to quantitatively predict the fitness of dynamic populations and to compare survival strategies according to environmental time-symmetries. These calculations suggested that persistence is a strategy used by bacterial populations to adapt to fluctuating environments. Knowledge of the phenotypic transition rates for persistence may provide statistical information about the typical environments of bacteria. We also describe a design of artificial

  19. [Chitinolytic activity of bacteria].

    Science.gov (United States)

    Saks, Elzbieta; Jankiewicz, Urszula

    2010-01-01

    Chitinolytic bacteria play an important role in degradation of chitin, one of the most abundant biopolymers in nature. These microorganisms synthesize specific enzymes, that catalyze hydrolysis of beta-1,4-glycosidic bonds in low-digestible chitin polymers, turning it into low-molecular, easy to digest compounds. During last decades many bacterial chitinolytic enzymes have been studied and characterized, mainly for their potential applications in agriculture, industry and medicine. Several chitinase classifications have been proposed, either on the base of substrate specificity or amino acid sequence similarities. X-ray crystallography and NMR spectroscopy techniques enabled the determination of three dimensional structure of some chitinases, what was helpful in explaining their catalytic mechanism. Development of biotechnology and molecular biology enables a deep research in regulation and cloning of bacterial chitinase genes.

  20. Bacteria, phages and septicemia.

    Directory of Open Access Journals (Sweden)

    Ausra Gaidelyte

    Full Text Available The use of phages is an attractive option to battle antibiotic resistant bacteria in certain bacterial infections, but the role of phage ecology in bacterial infections is obscure. Here we surveyed the phage ecology in septicemia, the most severe type of bacterial infection. We observed that the majority of the bacterial isolates from septicemia patients spontaneously secreted phages active against other isolates of the same bacterial strain, but not to the strain causing the disease. Such phages were also detected in the initial blood cultures, indicating that phages are circulating in the blood at the onset of sepsis. The fact that most of the septicemic bacterial isolates carry functional prophages suggests an active role of phages in bacterial infections. Apparently, prophages present in sepsis-causing bacterial clones play a role in clonal selection during bacterial invasion.

  1. Acoustofluidic bacteria separation

    International Nuclear Information System (INIS)

    Li, Sixing; Huang, Tony Jun; Ma, Fen; Zeng, Xiangqun; Bachman, Hunter; Cameron, Craig E

    2017-01-01

    Bacterial separation from human blood samples can help with the identification of pathogenic bacteria for sepsis diagnosis. In this work, we report an acoustofluidic device for label-free bacterial separation from human blood samples. In particular, we exploit the acoustic radiation force generated from a tilted-angle standing surface acoustic wave (taSSAW) field to separate Escherichia coli from human blood cells based on their size difference. Flow cytometry analysis of the E. coli separated from red blood cells shows a purity of more than 96%. Moreover, the label-free electrochemical detection of the separated E. coli displays reduced non-specific signals due to the removal of blood cells. Our acoustofluidic bacterial separation platform has advantages such as label-free separation, high biocompatibility, flexibility, low cost, miniaturization, automation, and ease of in-line integration. The platform can be incorporated with an on-chip sensor to realize a point-of-care sepsis diagnostic device. (paper)

  2. Acoustofluidic bacteria separation

    Science.gov (United States)

    Li, Sixing; Ma, Fen; Bachman, Hunter; Cameron, Craig E.; Zeng, Xiangqun; Huang, Tony Jun

    2017-01-01

    Bacterial separation from human blood samples can help with the identification of pathogenic bacteria for sepsis diagnosis. In this work, we report an acoustofluidic device for label-free bacterial separation from human blood samples. In particular, we exploit the acoustic radiation force generated from a tilted-angle standing surface acoustic wave (taSSAW) field to separate Escherichia coli from human blood cells based on their size difference. Flow cytometry analysis of the E. coli separated from red blood cells shows a purity of more than 96%. Moreover, the label-free electrochemical detection of the separated E. coli displays reduced non-specific signals due to the removal of blood cells. Our acoustofluidic bacterial separation platform has advantages such as label-free separation, high biocompatibility, flexibility, low cost, miniaturization, automation, and ease of in-line integration. The platform can be incorporated with an on-chip sensor to realize a point-of-care sepsis diagnostic device.

  3. Serovariedades y patrones de susceptibilidad a los antimicrobianos de cepas de Salmonella aisladas de alimentos en Cuba Serotypes and antimicrobial susceptibility patterns of Salmonella strains isolated from food in Cuba

    Directory of Open Access Journals (Sweden)

    Yamila Puig Peña

    2011-12-01

    Full Text Available Se describen los serotipos de 178 cepas de Salmonella enterica aisladas de alimentos en diferentes regiones de Cuba entre enero de 2008 y diciembre de 2009, y el patrón de susceptibilidad a los antimicrobianos de 100 aislados seleccionados mediante muestreo por estratos. Se identificaron 20 serovariedades de Salmonella entre las que predominaron S. Enteritidis (23%; S. Agona (13,5% y S. London (11,2%. Del total, 75% de las cepas fueron resistentes o presentaron resistencia intermedia a al menos uno de los fármacos probados, en el siguiente orden, según su frecuencia: tetraciclina (70,7%; ampicilina (22,7% y ácido nalidíxico (14,7%. Se identificaron 10 patrones de resistencia diferentes y predominaron las cepas resistentes o conresistencia intermedia a un fármaco (89,3%. Tres cepas (S. Infantis, S. Derby y S. Enteritidis fueron multirresistentes y una, de S. Enteritidis, dio un resultado no sensible al ácido nalidíxico y la ciprofloxacina. Se destaca la necesidad de extremar la vigilancia sanitaria integrada en el país para el control de la salmonelosis.The serotypes of 178 isolates of Salmonella enterica taken from food in different regions of Cuba between January 2008 and December 2009 were identified, and the antimicrobial susceptibility pattern of 100 selected isolates was determined by strata sampling. A total of 20 Salmonella serotypes were identified, with a predominance of S. Enteritidis (23%, S. Agona (13.5%, and S. London (11.2%. Of all the strains, 75% were resistant or presented intermediate resistance to at least one of the drugs tested, in the following order: tetracycline (70.7%, ampicillin (22.7%, and nalidixic acid (14.7%. Ten different resistance patterns were identified. The most frequent patterns corresponded to strains that were either drugresistant or had intermediate resistance (89.3%. Three strains (identified as S. Infantis, S. Derby, and S. Enteritidis were multiresistant, and one of them, S. Enteritidis, was

  4. Money and transmission of bacteria.

    NARCIS (Netherlands)

    Gedik, H.; Voss, T.A.; Voss, A.

    2013-01-01

    Money is one of the most frequently passed items in the world. The aim of this study was to ascertain the survival status of bacteria including Staphylococcus aureus, Escherichia coli, and Vancomycin- Resistant Enterococci (VRE) on banknotes from different countries and the transmission of bacteria

  5. Motility of electric cable bacteria

    DEFF Research Database (Denmark)

    Bjerg, Jesper Tataru; Damgaard, Lars Riis; Holm, Simon Agner

    2016-01-01

    Cable bacteria are filamentous bacteria that electrically couple sulfide oxidation and oxygen reduction at centimeter distances, and observations in sediment environments have suggested that they are motile. By time-lapse microscopy, we found that cable bacteria used gliding motility on surfaces...... with a highly variable speed of 0.50.3 ms1 (meanstandard deviation) and time between reversals of 155108 s. They frequently moved forward in loops, and formation of twisted loops revealed helical rotation of the filaments. Cable bacteria responded to chemical gradients in their environment, and around the oxic......-anoxic interface, they curled and piled up, with straight parts connecting back to the source of sulfide. Thus, it appears that motility serves the cable bacteria in establishing and keeping optimal connections between their distant electron donor and acceptors in a dynamic sediment environment....

  6. Índices fisiológicos associados com a "performance" aeróbia em corredores de "endurance": efeitos da duração da prova Índices fisiológicos asociados a la "performance" aerobia en competidores de "endurance": efectos de la duración de la prueba Physiological indexes associated with aerobic performance in endurance runners: effects of race duration

    Directory of Open Access Journals (Sweden)

    Benedito Sérgio Denadai

    2004-10-01

    .000m (17,9 ± 0,9 fueron significantemente diferentes. La regresión múltiple stepwise mostró que el LAn fue el único elemento de predicción de la performance de la v5.000m, explicando el 50% de la variación de esta performance. Para la v1.500m, el Tlim y la vVO2max explicaron el 88% de la variación de la performance. Con base en nuestros resultados, se puede concluir que la validez de los índices fisiológicos (VO2max, vVO2max, Tlim, EC y LAn, para la predicción de la performance aerobia de atletas de endurance depende de la distancia de la prueba (1.500 x 5.000m analizada.The aim of this study was to assess the validity of the maximal oxygen uptake (VO2max, the velocity at VO2max (vVO2max, time to exhaustion at vVO2max (Tlim, running economy (RE and anaerobic threshold (AnT to predict the aerobic performance of the endurance athletes. Fourteen well-trained long-distance runners (33.4 ± 4.4 yr.; 62.7 ± 4.3 kg; 166.1 ± 5.0 cm; VO2max = 60.4 ± 5.9 ml.kg-1.min-1 underwent the following tests: a simulated competitions in the distances of 1500 and 5000 m and; b laboratory treadmill tests to determine their VO2max, vVO2max, Tlim, EC and AnT. The velocities (km/h at vVO2max (18.7 + 0.8, LAn (17.3 + 1.1 v1500 m (19.9 + 0.8 and v5000 m (17.9 + 0.9 were significantly different. A stepwise multiple-regression analysis revealed that AnT alone was the best single predictor of v-5000 m and explained 50% of the variability in 5000 m running velocity. For v1.500 m, Tlim and vVO2max explained 88 % of the variability of the performance. We conclude that, in a group of well-trained long-distance runners, the validity of the physiological indexes (VO2max, vVO2max, Tlim, EC e LAn to predict the aerobic performance is dependent of the distance (1500 x 5000 m analyzed.

  7. METHODS FOR DETECTING BACTERIA USING POLYMER MATERIALS

    NARCIS (Netherlands)

    Van Grinsven Bart Robert, Nicolaas; Cleij, Thomas

    2017-01-01

    A method for characterizing bacteria includes passing a liquid containing an analyte comprising a first bacteria and a second bacteria over and in contact with a polymer material on a substrate. The polymer material is formulated to bind to the first bacteria, and the first bacteria binds to the

  8. Frecuencia de genes de virulencia sfa/foc y fyuA en Escherichia coli aislada de adultos con infección del tracto urinario en Bucaramanga, Santander

    Directory of Open Access Journals (Sweden)

    Libeth Yajaira Criado Guerrero

    2016-06-01

    Full Text Available Introducción: Aproximadamente, el 80% de los casos de las infecciones del tracto urinario (ITUs son causadas por Escherichia coli uropatógenas (UPEC. La diversidad entre los patotipos de E. coli es debida a la presencia de genes específicos asociados a la virulencia. La patogénesis por E. coli en ITUs ha sido poco estudiada en nuestra región, por lo que identificar los genes de virulencia en cepas de E. coli permitirá ampliar el conocimiento de su patogénesis. Objetivo: Estandarizar la técnica de PCR para la identificación de los genes de virulencia sfa/foc y fyuA y describir su frecuencia en las cepas de E. coli aisladas. Materiales y métodos: Se incluyeron sujetos de 18 o más años, que consultaron de marzo a diciembre de 2015 a la E.S.E ISABU de Bucaramanga, Santander, con sintomatología urinaria a quienes se les confirmó infección por E. coli en urocultivo (>105 UFC/ml. Se excluyeron mujeres embarazadas, pacientes con urocultivos polimicrobianos, con diagnóstico de VIH o cáncer o con tratamiento inmunosupresor y pacientes con antecedente de uso de sonda vesical en los últimos siete días u hospitalizados en las últimas 72 horas antes del día del inicio de los síntomas. Los urocultivos se sembraron por el método del asa calibrada (0.01 ml en agar sangre. Siembras adicionales se realizaron en agar Mc Conkey y en cromogénicos específicos. La identificación de E. coli se realizó en el equipo Phoenix 100 de BD y en el medio SIM. Finalmente, cada cepa se preservó a -80°C en caldo Luria con glicerol (15% (DO550 1.8-2.0. La obtención del DNA bacteriano se realizó mediante el método de lisis por ebullición. Se realizó PCR Multiplex, para la amplificación del gen fyuA se utilizaron los iniciadores F (5’-CTCCGGAGAACTGGGTGCATCTTAC-3’ y R (5’-CGGAGGAGTAATTACAAACCTGGCA-3’, y para el gen sfa/focDE los iniciadores F (5’-CTCCGGAGAACTGGGTGCATCTTAC-3’, R (5’-CGGAGGAGTAATTACAAACCTGGCA-3’. La denaturación inicial

  9. Interactions between diatoms and bacteria.

    Science.gov (United States)

    Amin, Shady A; Parker, Micaela S; Armbrust, E Virginia

    2012-09-01

    Diatoms and bacteria have cooccurred in common habitats for hundreds of millions of years, thus fostering specific associations and interactions with global biogeochemical consequences. Diatoms are responsible for one-fifth of the photosynthesis on Earth, while bacteria remineralize a large portion of this fixed carbon in the oceans. Through their coexistence, diatoms and bacteria cycle nutrients between oxidized and reduced states, impacting bioavailability and ultimately feeding higher trophic levels. Here we present an overview of how diatoms and bacteria interact and the implications of these interactions. We emphasize that heterotrophic bacteria in the oceans that are consistently associated with diatoms are confined to two phyla. These consistent bacterial associations result from encounter mechanisms that occur within a microscale environment surrounding a diatom cell. We review signaling mechanisms that occur in this microenvironment to pave the way for specific interactions. Finally, we discuss known interactions between diatoms and bacteria and exciting new directions and research opportunities in this field. Throughout the review, we emphasize new technological advances that will help in the discovery of new interactions. Deciphering the languages of diatoms and bacteria and how they interact will inform our understanding of the role these organisms have in shaping the ocean and how these interactions may change in future oceans.

  10. Interactions between Diatoms and Bacteria

    Science.gov (United States)

    Amin, Shady A.; Parker, Micaela S.

    2012-01-01

    Summary: Diatoms and bacteria have cooccurred in common habitats for hundreds of millions of years, thus fostering specific associations and interactions with global biogeochemical consequences. Diatoms are responsible for one-fifth of the photosynthesis on Earth, while bacteria remineralize a large portion of this fixed carbon in the oceans. Through their coexistence, diatoms and bacteria cycle nutrients between oxidized and reduced states, impacting bioavailability and ultimately feeding higher trophic levels. Here we present an overview of how diatoms and bacteria interact and the implications of these interactions. We emphasize that heterotrophic bacteria in the oceans that are consistently associated with diatoms are confined to two phyla. These consistent bacterial associations result from encounter mechanisms that occur within a microscale environment surrounding a diatom cell. We review signaling mechanisms that occur in this microenvironment to pave the way for specific interactions. Finally, we discuss known interactions between diatoms and bacteria and exciting new directions and research opportunities in this field. Throughout the review, we emphasize new technological advances that will help in the discovery of new interactions. Deciphering the languages of diatoms and bacteria and how they interact will inform our understanding of the role these organisms have in shaping the ocean and how these interactions may change in future oceans. PMID:22933565

  11. Review on SERS of Bacteria

    Directory of Open Access Journals (Sweden)

    Pamela A. Mosier-Boss

    2017-11-01

    Full Text Available Surface enhanced Raman spectroscopy (SERS has been widely used for chemical detection. Moreover, the inherent richness of the spectral data has made SERS attractive for use in detecting biological materials, including bacteria. This review discusses methods that have been used to obtain SERS spectra of bacteria. The kinds of SERS substrates employed to obtain SERS spectra are discussed as well as how bacteria interact with silver and gold nanoparticles. The roll of capping agents on Ag/Au NPs in obtaining SERS spectra is examined as well as the interpretation of the spectral data.

  12. Beer spoilage bacteria and hop resistance

    NARCIS (Netherlands)

    Sakamoto, K; Konings, WN

    2003-01-01

    For brewing industry, beer spoilage bacteria have been problematic for centuries. They include some lactic acid bacteria such as Lactobacillus brevis, Lactobacillus lindneri and Pediococcus damnosus, and some Gram-negative bacteria such as Pectinatus cerevisiiphilus, Pectinatus frisingensis and

  13. Gut Bacteria Affect Immunotherapy Response

    Science.gov (United States)

    Three new studies have identified intestinal bacteria that appear to influence the response to checkpoint inhibitors. This Cancer Currents blog post explains how the researchers think their findings could be used to improve patients’ responses to these immunotherapy drugs.

  14. Sewage-pollution indicator bacteria

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaiah, N.; Rodrigues, V.; Alwares, E.; Rodrigues, C.; Baksh, R.; Jayan, S.; Mohandass, C.

    indiscriminate, deliber- ate, accidental, or regular/routine disposals), higher will be the number of coliforms in environmental samples. Further, microbiologists rely on the principle that higher the incidence of sewage indicator bacteria in any environment...

  15. Interferencia entre bacterias comensales de faringe y patogénesis de oído medio en un modelo animas de otitis media

    Directory of Open Access Journals (Sweden)

    LM Villafane

    2013-01-01

    Full Text Available Objetivo: determinar in vivo la interacción entre bacterias comensales aisladas  de faringe de niños sanos y S. pneumoniae, en un modelo animal (Chinchilla laniger de otitis media. Metodos: estudio experimental Intervenciones: Suspensiones de los serotipos 18A y 9V de Spn fueron inyectados intra-peritonealmente en dos chinchillas y luego recuperados mediante cultivo de órganos y sangre de las mismas. Empleando suspensiones de las cepas animalizadas se inocularon intranasalmente cuatro chinchillas, y solo a dos de ellas se le inoculo una mezcla de las bacterias comensales (Streptococcus mitis, Streptococcus parasanguinis. Con un otoscopio se examinó la evolución de la infección a los 7 y 14 días. Se sacrificaron los animales y se tomaron muestras de los oídos para un examen histológico. Resultados: Mediante otoscopia, se observó al día 14 que todos presentaron una membrana timpánica hiperémica sin efusión, presentándose con mayor intensidad en aquellos que recibieron el tratamiento. La histología confirmó que la administración del tratamiento no evitó que la infección evolucionara, advirtiéndose que las infectadas con el serotipo 8A y tratadas fueron las que presentaron el tejido epitelial menos comprometido respecto al resto. Conclusiones: Spn y las bacterias comensales podrían establecer una relación competitiva, y el efecto moderador en la progresión de la infección de otitis media dependería del serotipo involucrado.

  16. INTERFERENCIA ENTRE BACTERIAS COMENSALES DE FARINGE Y PATÓGENAS DE OÍDO MEDIO EN UN MODELO ANIMAL DE OTITIS MEDIA

    Directory of Open Access Journals (Sweden)

    LM Villafañe

    2012-01-01

    Full Text Available Objetivo: determinar in vivo la interacción entre bacterias comensales aisladas de faringe de niños sanos y S. pneumoniae, en un modelo animal (Chinchilla laniger de otitis media. Metodos: estudio experimental Intervenciones: Suspensiones de los serotipos 18A y 9V de Spn fueron inyectados intra-peritonealmente en dos chinchillas y luego recuperados mediante cultivo de órganos y sangre de las mismas. Empleando suspensiones de las cepas animalizadas se inocularon intranasalmente cuatro chinchillas, y solo a dos de ellas se le inoculo una mezcla de las bacterias comensales (Streptococcus mitis, Streptococcus parasanguinis. Con un otoscopio se examinó la evolución de la infección a los 7 y 14 días. Se sacrificaron los animales y se tomaron muestras de los oídos para un examen histológico. Resultados: Mediante otoscopia, se observó al día 14 que todos presentaron una membrana timpánica hiperémica sin efusión, presentándose con mayor intensidad en aquellos que recibieron el tratamiento. La histología confirmó que la administración del tratamiento no evitó que la infección evolucionara, advirtiéndose que las infectadas con el serotipo 8A y tratadas fueron las que presentaron el tejido epitelial menos comprometido respecto al resto. Conclusiones: Spn y las bacterias comensales podrían establecer una relación competitiva, y el efecto moderador en la progresión de la infección de otitis media dependería del serotipo involucrado.

  17. LACTIC ACID BACTERIA: PROBIOTIC APPLICATIONS

    OpenAIRE

    NEENA GARG

    2015-01-01

    Lactic acid bacteria (LAB) is a heterotrophic Gram-positive bacteria which under goes lactic acid fermentations and leads to production of lactic acid as an end product. LAB includes Lactobacillus, Leuconostoc, Pediococcus, Lactococcus and Streptococcus which are grouped together in the family lactobacillaceae. LAB shows numerous antimicrobial activities due to production of antibacterial and antifungal compounds such as organic acids, bacteriocins, diacetyl, hydrogen peroxide and reutrin. LA...

  18. Thymidine kinase diversity in bacteria

    DEFF Research Database (Denmark)

    Sandrini, Michael; Clausen, A.R.; Munch-Petersen, B.

    2006-01-01

    Thymidine kinases (TKs) appear to be almost ubiquitous and are found in nearly all prokaryotes, eukaryotes, and several viruses. They are the key enzymes in thymidine salvage and activation of several anti-cancer and antiviral drugs. We show that bacterial TKs can be subdivided into 2 groups. The....... The TKs from Gram-positive bacteria are more closely related to the eukaryotic TK1 enzymes than are TKs from Gram-negative bacteria....

  19. Filtrating forms of soil bacteria

    Science.gov (United States)

    Van'kova, A. A.; Ivanov, P. I.; Emtsev, V. T.

    2013-03-01

    Filtrating (ultramicroscopic) forms (FF) of bacteria were studied in a soddy-podzolic soil and the root zone of alfalfa plants as part of populations of the most widespread physiological groups of soil bacteria. FF were obtained by filtering soil solutions through membrane filters with a pore diameter of 0.22 μm. It was established that the greater part of the bacteria in the soil and in the root zone of the plants has an ultramicroscopic size: the average diameter of the cells is 0.3 μm, and their length is 0.6 μm, which is significantly less than the cell size of banal bacteria. The number of FF varies within a wide range depending on the physicochemical conditions of the habitat. The FF number's dynamics in the soil is of a seasonal nature; i.e., the number of bacteria found increases in the summer and fall and decreases in the winter-spring period. In the rhizosphere of the alfalfa, over the vegetation period, the number of FF and their fraction in the total mass of the bacteria increase. A reverse tendency is observed in the rhizoplane. The morphological particularities (identified by an electron microscopy) and the nature of the FF indicate their physiological activity.

  20. Infecciones por bacterias poco comunes y oncogénesis bacteriana

    Directory of Open Access Journals (Sweden)

    Horacio A. Lopardo

    Full Text Available La recuperación de algunos microorganismos de aislamiento esporádico en el laboratorio de microbiología clínica podría significar la existencia de algún defecto inmunitarioespecial en el paciente. Por ejemplo, se ha descrito una importante correlación entre Clostridium septicum y carcinoma de colon, y se han visto relacionadas con leucemias y linfomas a especies que aparecen casi siempre como contaminantes (Bacillus spp., Corynebacterium spp. y a otras raramente aisladas en otros contextos (Capnocytophaga spp.. Hay bacterias que se aíslan casi exclusivamente de pacientes con sida (Rhodococcus equi. Se ha observado una mayor frecuencia de infecciones por Campylobacter spp., Aeromonas spp. y estreptococos del grupo G y del grupo mitis en individuos con algún tipo de cáncer que en el resto de los pacientes. También hay bacterias que son marcadoras de algún cáncer no detectado o que afectan más a pacientes neutropénicos que a individuos normoinmunes. La alteración de la reacción inflamatoria, la linfoproliferación mediada por antígenos bacterianos y la inducción de hormonas que aumentan la proliferación de las células epiteliales podrían ser causas de la oncogénesis bacteriana. Los ejemplos clásicos son el adenocarcinoma gástrico inducido por Helicobacter pylori, la asociación de la bacteriemia por estreptococos del grupo bovis y el cáncer de colon y los linfomas de tejido linfoide asociado a mucosas (MALT en vinculación con especies de Helicobacter (MALT gástricos y con Chlamydophila spp. (MALT oculares. El aislamiento de alguno de estos patógenos debería ser un llamado de atención para inducir al estudio de alguna enfermedad maligna.

  1. Culture supernatants from V. cholerae O1 ElTor strains isolated from different geographic areas induce cell vacuolation and cytotoxicity Cepas de V. cholerae O1 biotipo ElTor aisladas de diferente origen geográfico inducen vacuolización celular y citotoxicidad

    Directory of Open Access Journals (Sweden)

    Jorge E Vidal

    2009-02-01

    Full Text Available OBJECTIVE: To investigate whether the HlyA-induced vacuolating effect is produced by V. cholerae O1 ElTor strains isolated from different geographic origins, including Mexico. MATERIAL AND METHODS: Supernatant-induced haemolysis, vacuolating activity and cytotoxicity in Vero cells were recorded. PCR, RFLP analysis and molecular cloning were performed. RESULTS: All ElTor strains analyzed induced cellular vacuolation. Ribotype 2 strains isolates from the U.S. gulf coast yielded the highest titer of vacuolating activity. Eight of nine strains were haemolytic, while all strains were PCR positive for the hlyA gene. We cloned the hlyA gene from two ElTor strains, a toxigenic (2514-88, ctxAB+ and a non-toxigenic Mexican strain (CM 91-3, ctxAB-. Supernatant from those recombinant E. coli strains induced haemolysis, cell vacuolation and cytotoxicity. RFLP-PCR analysis revealed similarities in the hlyA gene from all strains tested. CONCLUSION: The HlyA-induced vacuolating effect is a widespread phenotype of epidemic V. cholerae O1 ElTor strains.OBJETIVO: Analizar el efecto vacuolizante de cepas de V. cholerae O1 ElTor aisladas de diferente origen geográfico, incluyendo México. MATERIAL Y MÉTODOS: Se realizaron pruebas de hemolisis, vacuolización y citotoxicidad en células Vero, así como PCR, análisis por RFLP y clonación molecular. RESULTADOS: Todas las cepas indujeron el efecto vacuolizante. Las cepas del ribotipo 2, aisladas de las costas del Golfo en Estados Unidos, presentaron títulos altos de vacuolización. El gen hlyA fue amplificado en las nueve cepas mediante PCR, aunque sólo ocho fueron hemolíticas. Se clonó el gen hlyA de una cepa toxigénica (2514-88, ctxAB+ y de una cepa no toxigénica aislada en México (CM 91-3, ctxAB-. El sobrenadante de las clonas recombinantes indujo hemólisis, efecto vacuolizante y citotoxicidad. El RFLP mostró alta similitud del gen hlyA de las cepas estudiadas. CONCLUSIÓN: El efecto vacuolizante es un

  2. ESTABILIDAD DE ALMACENAMIENTO DE ENSILADOS BIOLÓGICOS A PARTIR DE RESIDUOS DE PESCADO INOCULADOS CON BACTERIAS ÁCIDO -LÁCTICAS

    Directory of Open Access Journals (Sweden)

    MS Holguín

    2009-01-01

    Full Text Available Se elaboraron cuatro muestras por triplicado de ensilados biológicos para alimentación animal a partir de residuos de pescado, utilizando melaza como fuente de carbohidratos para el crecimiento de cuatro cepas de bacterias ácido-lácticas (BAL aisladas de los mismos, sometidos a un tiempo de incubación de 72 horas y temperatura de 35 °C (±2 °C para acidificar el producto como método de conservación. A continuación los ensilados se almacenaron durante 180 días a temperatura ambiente para evaluar la estabilidad en anaquel, por medio de análisis químicos, composición química proximal, aminograma, recuentos microbiológicos y algunos de tipo organoléptico del producto terminado. Las cepas fueron eficientes en el proceso de fermentación, causando inhibición del crecimiento de microorganismos indeseables y aportando características organolépticas agradables. El ensilado elaborado con la cepa C14 provocó el descenso del pH en menos de 72 horas de incubación. Ninguno de los productos sufrió deterioro evidente durante el almacenamiento; presentaron porcentajes aceptables de proteína, grasa, cenizas, carbohidratos y aminoácidos, que hacen del producto una fuente utilizable en formulaciones de alimentos para animales.

  3. Analysis, simulation and control of electromagnetic transients in gas insulated substations in SF6 by means of grounding grid; Analisis, simulacion y control de transitorios electromagneticos en subestaciones aisladas en SF6 por medio de redes de tierra

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez Martinez, Gaston

    2007-12-15

    operaciones de maniobra, originando el sobrevoltaje transitorio ultra rapido (VFTO) y el voltaje transitorio encapsulado (TEV). Esta investigacion se centra en disminuir la magnitud del VFTO y el TEV a traves del diseno y rediseno de redes de tierra para subestaciones aisladas en gas. El objetivo de este trabajo es el de disenar una red de tierra para una subestacion aerea y redisenarla para una subestacion GIS utilizando el modelo detallado de la subestacion en SF6 interconectado con la red de tierra aerea hasta conseguir, a traves de la adicion metodologica de varillas de tierra, disminuir el VFTO y el TVE dentro del GIS. Los resultados de la simulacion muestran que la red de tierra disenada permite disminuir considerablemente la magnitud del VFTO; sin embargo, este diseno no consigue atenuar adecuadamente la magnitud del TEV.

  4. Human body may produce bacteria.

    Science.gov (United States)

    Salerian, Alen J

    2017-06-01

    "Human body may produce bacteria" proposes that human body may produce bacteria and represent an independent source of infections contrary to the current paradigm of infectious disorders proposed by Louis Pasteur in 1880. The following observations are consistent with this hypothesis: A. Bidirectional transformations of both living and nonliving things have been commonly observed in nature. B. Complex multicellular organisms harbor the necessary properties to produce bacteria (water, nitrogen and oxygen). C. Physical laws suggest any previously observed phenomenon or action will occur again (life began on earth; a non living thing). D. Animal muscle cells may generate energy (fermentation). E. Sterilized food products (i.e. boiled eggs), may produce bacteria and fungus under special conditions and without any exposure to foreign living cells. "Human body may produce bacteria" may challenge the current medical paradigm that views human infectious disorders as the exclusive causative byproducts of invading foreign cells. It may also introduce new avenues to treat infectious disorders. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Estudio comparativo de cimentaciones aisladas en la ciudad de Cuenca diseñadas por el método de la presión admisible con los obtenidos aplicando el método de los estados límites

    OpenAIRE

    Cabrera Palacios, Eduardo Guillermo

    2010-01-01

    En este trabajo se realiza un estudio comparativo de cimentaciones aisladas en la ciudad de Cuenca, diseñadas por el método de la Presión Admisible con los obtenidos aplicando el método de los Estados Limites; se analiza el problema de los métodos de diseño de cimentaciones utilizados en la ciudad de Cuenca, estableciéndose como objetivo primordial el demostrar que para el diseño de cimentaciones superficiales, el método que permite diseñar cimentaciones más económicas es el método de los Est...

  6. Estudio de la susceptibilidad a vancomicina de cepas de Staphyloccus spp., aisladas del hospital Antonio Patricio de Alcalá, Cumaná, estado Sucre | Vancomycin susceptibility study of Staphylococcus spp. Strains isolated from Antonio Patricio de Alcalá hospital, Cumaná, Sucre state

    Directory of Open Access Journals (Sweden)

    Lorena Abadia-Patiño

    2017-10-01

    Full Text Available De todas las cepas de Staphylocccus aureus almacenadas en el cepario del Laboratorio de Resistencia Bacteriana del IIBCAUDO, se analizaron 14 para determinar la disminución de susceptibilidad a vancomicina. Sesenta y cuatro por ciento de las cepas crecieron en el cribado de vancomicina. La CMI a vancomicina de las cepas estuvo entre 1 y 2 mg/L por microdilución. La CMI por dilución en agar fue entre 2 y 4 mg/L. La CMB de las cepas fue de 2 y 4 mg/L. Ninguna cepa fue tolerante. No se detectaron cepas hVISA por PAP-AUC. Se recomienda realizar el cribado de vancomicina en cepas aisladas de sitios estériles.

  7. Chitin Degradation In Marine Bacteria

    DEFF Research Database (Denmark)

    Paulsen, Sara; Machado, Henrique; Gram, Lone

    2015-01-01

    Introduction: Chitin is the most abundant polymer in the marine environment and the second most abundant in nature. Chitin does not accumulate on the ocean floor, because of microbial breakdown. Chitin degrading bacteria could have potential in the utilization of chitin as a renewable carbon...... and nitrogen source in the fermentation industry.Methods: Here, whole genome sequenced marine bacteria were screened for chitin degradation using phenotypic and in silico analyses.Results: The in silico analyses revealed the presence of three to nine chitinases in each strain, however the number of chitinases...... chitin regulatory system.Conclusions: This study has provided insight into the ecology of chitin degradation in marine bacteria. It also served as a basis for choosing a more efficient chitin degrading production strain e.g. for the use of chitin waste for large-scale fermentations....

  8. Methylotrophic bacteria in sustainable agriculture.

    Science.gov (United States)

    Kumar, Manish; Tomar, Rajesh Singh; Lade, Harshad; Paul, Diby

    2016-07-01

    Excessive use of chemical fertilizers to increase production from available land has resulted in deterioration of soil quality. To prevent further soil deterioration, the use of methylotrophic bacteria that have the ability to colonize different habitats, including soil, sediment, water, and both epiphytes and endophytes as host plants, has been suggested for sustainable agriculture. Methylotrophic bacteria are known to play a significant role in the biogeochemical cycle in soil ecosystems, ultimately fortifying plants and sustaining agriculture. Methylotrophs also improve air quality by using volatile organic compounds such as dichloromethane, formaldehyde, methanol, and formic acid. Additionally, methylotrophs are involved in phosphorous, nitrogen, and carbon cycling and can help reduce global warming. In this review, different aspects of the interaction between methylotrophs and host plants are discussed, including the role of methylotrophs in phosphorus acquisition, nitrogen fixation, phytohormone production, iron chelation, and plant growth promotion, and co-inoculation of these bacteria as biofertilizers for viable agriculture practices.

  9. Bacteria on the hands of school-age children at a Pediatric Hospitalization Unit Bacterias presentes en las manos de los niños en edad escolar en la Unidad de Internación Pediátrica Bactérias presentes nas mãos dos meninos em idade escolar na unidade de internação pediátrica

    Directory of Open Access Journals (Sweden)

    Marcela Cristina Candido De Almeida

    2012-07-01

    Full Text Available Objective. To estimate the prevalence of bacteria isolated in samples from the hands of school-age children at a hospitalization unit. Methodology. In 2009, strains were cultured from the hands of 90 school-age children at the pediatric hospitalization unit of Hospital Estadual Bauru (São Paulo, Brazil. After culture of the samples, the isolated bacteria were identified. Results. In 98% of the samples taken from the children, bacteria were isolated. Coagulase-negative Staphilococcus was isolated in 64% of the samples, followed by Staphilococcus aureus (5% and Pseudomonas aeruginosa (1%. Conclusion. In most of the samples from the children's hands, bacteria were isolated. Therefore, educative actions about hygiene habits in- and outside the hospital environment should be reinforced, aimed at children and their companions.Objetivo. Estimar la prevalencia de bacterias aisladas en las manos de los niños en edad escolar en una unidad de internación. Metodología. En 2009 se hicieron cultivos de las manos de 90 niños en edad escolar de la unidad de internación pediátrica del Hospital Estadual Bauru (São Paulo, Brasil. Se hizo cultivo de las muestras y posteriormente se realizó identificación de las bacterias aisladas. Resultados. En el 98% de las muestras tomadas a los niños se hicieron aislamientos de bacterias. Stafilococcus coagulasa negativa se aisló en el 64% de las muestras; Staphilococcus aureus, en un 5%, y Pseudomonas aeruginosa, en un 1%. Conclusión. En la mayor parte de las muestras de las manos de los niños internados se aislaron bacterias, por lo que se deben reforzar las acciones educativas a los niños y a sus acompañantes en relación con los hábitos de higiene en el ambiente hospitalario y fuera de él.Estimar a prevalência de bactérias isoladas em mostras das mãos dos meninos em idade escolar numa unidade de internação. Metodologia. Em 2009 se fizeram cultivos das mãos de 90 meninos em idade escolar da unidade de

  10. Prevalence of R-type ACSSuT in strains of Salmonella serovar Typhimurium DT193 isolated from human infections in Brazil Prevalencia de resistencia de tipo ACSSuT en cepas de Salmonella serovariedad Typhimurium DT193 aisladas a partir de infecciones humanas en el Brasil

    Directory of Open Access Journals (Sweden)

    Eliane Moura Falavina dos Reis

    2011-06-01

    fagotipo definitivo (DT 193 aisladas de fuentes de origen humano durante las cuatro últimas décadas. MÉTODOS: Entre el 2008 y el 2010 se seleccionaron 553 aislados de DT193 entre 810 cepas de Salmonella serovariedad Typhimurium fagotipificadas aisladas desde la década de 1970 hasta el 2008, y en ellos se analizó la resistencia a ACSSuT: se estudiaron 91 cepas aisladas durante la década de 1970, 65 aisladas durante la década de 1980, 70 aisladas durante la década de 1990, y 327 aisladas entre el 2000 y el 2008, respectivamente. Los perfiles de resistencia a los antibióticos se determinaron mediante el método de difusión en disco. RESULTADOS: El antibiograma indicó que 20,9% (116 de todos los aislados que se analizaron fueron resistentes a ACSSuT, 52,0% (287 fueron resistentes a uno o más antibióticos del grupo ACSSuT y 27,1% (150 no fueron resistentes (es decir, fueron sensibles a dichos antibióticos. Según el análisis, la resistencia general a los antibióticos fue muy alta en la década de 1970 (y comprendió a 99,0% de los aislados de ese período y continuó siendo alta durante la década de 1980, cuando 95,4% de los aislados presentó algún tipo de resistencia a los antibióticos y la incidencia de Salmonella serovariedad Typhimurium DT193 con resistencia de tipo ACSSuT aumentó hasta 73,8%. La resistencia de tipo ACSSuT descendió a 27,1% (31 aislados durante la década de 1990, y a 5,2% (17 aislados entre el 2000 y el 2008, a pesar del aumento importante en el número de aislados que se evaluaron (397 frente a 204, 111 y 98 en las tres décadas anteriores, respectivamente. CONCLUSIONES: Aunque la prevalencia de Salmonella serovariedad Typhimurium DT193 con resistencia de tipo ACSSuT en el Brasil ha disminuido desde la década de 1970, los marcadores de resistencia a ACSSuT continúan en circulación. Por consiguiente, debe llevarse a cabo una vigilancia permanente para evaluar la aparición de infecciones por Salmonella serovariedad Typhimurium DT

  11. 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

    Directory of Open Access Journals (Sweden)

    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

  12. Probiotic bacteria in dairy products

    OpenAIRE

    KORANDOVÁ, Květa

    2012-01-01

    Probiotic microorganisms are live organisms that facilitate optimal composition of intestinal flora. The thesis deals with the positive influence of probiotic microorganisms on human health. It describes the most frequently used bacteria family, which includes Lactobacillus, Lactococcus, Streptococcus and Bifidobacterium. The thesis also deals with health, microbiologic and technological requirements necessary for probiotic effectiveness. It offers an overview of characteristics of products c...

  13. Biofilms: Community Behavior by Bacteria

    Indian Academy of Sciences (India)

    IAS Admin

    ment of Microbiology and. Cell Biology, Indian. Institute of Science. Her laboratory is interested in host–pathogen interaction and understanding the survival strategies of pathogens. Biofilm is a lifestyle exhibited by bacteria. This is an intricate process that involves cell–cell communication which leads to the regulation of ...

  14. ENDOSPORES OF THERMOPHILIC FERMENTATIVE BACTERIA

    DEFF Research Database (Denmark)

    Volpi, Marta

    2016-01-01

    solely based on endospores of sulphate-reducing bacteria (SRB), which presumably constitute only a small fraction of the total thermophilic endospore community reaching cold environments. My PhD project developed an experimental framework for using thermophilic fermentative endospores (TFEs) to trace...

  15. Programmed survival of soil bacteria

    DEFF Research Database (Denmark)

    Jensen, Lars Bogø; Molin, Søren; Sternberg, Claus

    Biological containment systems have been developed for Pseudomonas putida and related soil bacteria. The systems are based on combinations of lethal genes and regulated gene expression. Two types of killing function have been employed: 1) A membrane protein interfering with the membrane potential...

  16. Synthetic Biology in Streptomyces Bacteria

    NARCIS (Netherlands)

    Medema, Marnix H.; Breitling, Rainer; Takano, Eriko

    2011-01-01

    Actinomycete bacteria of the genus Streptomyces are major producers of bioactive compounds for the biotechnology industry. They are the source of most clinically used antibiotics, as well as of several widely used drugs against common diseases, including cancer . Genome sequencing has revealed that

  17. Deodorant bacteria; Des bacteries desodorisantes

    Energy Technology Data Exchange (ETDEWEB)

    Fanlo, J.L. [Ecole Nationale Superieure des Mines, 30 - Ales (France)

    1998-02-01

    Purifying bacteria: if this concept is not new, its application to gases cleansing has only been developed recently. This method allows to eliminate the volatile organic compounds and the gaseous effluents odors which come from industrial sites. Three bioreactors types exist at the present time. Their principles are explained. (O.M.) 6 refs.

  18. Manipulating Genetic Material in Bacteria

    Science.gov (United States)

    1998-01-01

    Lisa Crawford, a graduate research assistant from the University of Toledo, works with Laurel Karr of Marshall Space Flight Center (MSFC) in the molecular biology laboratory. They are donducting genetic manipulation of bacteria and yeast for the production of large amount of desired protein. Photo credit: NASA/Marshall Space Flight Center (MSFC)

  19. Functional genomics of intracellular bacteria.

    Science.gov (United States)

    de Barsy, Marie; Greub, Gilbert

    2013-07-01

    During the genomic era, a large amount of whole-genome sequences accumulated, which identified many hypothetical proteins of unknown function. Rapidly, functional genomics, which is the research domain that assign a function to a given gene product, has thus been developed. Functional genomics of intracellular pathogenic bacteria exhibit specific peculiarities due to the fastidious growth of most of these intracellular micro-organisms, due to the close interaction with the host cell, due to the risk of contamination of experiments with host cell proteins and, for some strict intracellular bacteria such as Chlamydia, due to the absence of simple genetic system to manipulate the bacterial genome. To identify virulence factors of intracellular pathogenic bacteria, functional genomics often rely on bioinformatic analyses compared with model organisms such as Escherichia coli and Bacillus subtilis. The use of heterologous expression is another common approach. Given the intracellular lifestyle and the many effectors that are used by the intracellular bacteria to corrupt host cell functions, functional genomics is also often targeting the identification of new effectors such as those of the T4SS of Brucella and Legionella.

  20. Biofilms: Community Behavior by Bacteria

    Indian Academy of Sciences (India)

    IAS Admin

    phenotypically planktonic bacteria, leaving behind an empty colony. Dispersal is usually ... dental plaque biofilms includes a series of steps that begins with the initial colonization of the pellicle and ends with the complex formation ... treated by the biofilm method (activated sludge) is very effective. Biofilms can also be used ...

  1. Automated radiometric detection of bacteria

    International Nuclear Information System (INIS)

    Waters, J.R.

    1974-01-01

    A new radiometric method called BACTEC, used for the detection of bacteria in cultures or in supposedly sterile samples, was discussed from the standpoint of methodology, both automated and semi-automated. Some of the results obtained so far were reported and some future applications and development possibilities were described. In this new method, the test sample is incubated in a sealed vial with a liquid culture medium containing a 14 C-labeled substrate. If bacteria are present, they break down the substrate, producing 14 CO 2 which is periodically extracted from the vial as a gas and is tested for radioactivity. If this gaseous radioactivity exceeds a threshold level, it is evidence of bacterial presence and growth in the test vial. The first application was for the detection of bacteria in the blood cultures of hospital patients. Data were presented showing typical results. Also discussed were future applications, such as rapid screening for bacteria in urine industrial sterility testing and the disposal of used 14 C substrates. (Mukohata, S.)

  2. Alternative sources of Legionella bacteria

    NARCIS (Netherlands)

    van Heijnsbergen, H.H.L.

    2017-01-01

    Legionella bacteria can cause Legionnaires’ disease (LD) in humans. Symptoms of LD can range from mild disease to severe pneumonia with sometimes fatal outcome. In the Netherlands, the most important infective agent is Legionella pneumophila. L. pneumophila infection is associated with aquatic

  3. Fuzzy species among recombinogenic bacteria

    Directory of Open Access Journals (Sweden)

    Fraser Christophe

    2005-03-01

    Full Text Available Abstract Background It is a matter of ongoing debate whether a universal species concept is possible for bacteria. Indeed, it is not clear whether closely related isolates of bacteria typically form discrete genotypic clusters that can be assigned as species. The most challenging test of whether species can be clearly delineated is provided by analysis of large populations of closely-related, highly recombinogenic, bacteria that colonise the same body site. We have used concatenated sequences of seven house-keeping loci from 770 strains of 11 named Neisseria species, and phylogenetic trees, to investigate whether genotypic clusters can be resolved among these recombinogenic bacteria and, if so, the extent to which they correspond to named species. Results Alleles at individual loci were widely distributed among the named species but this distorting effect of recombination was largely buffered by using concatenated sequences, which resolved clusters corresponding to the three species most numerous in the sample, N. meningitidis, N. lactamica and N. gonorrhoeae. A few isolates arose from the branch that separated N. meningitidis from N. lactamica leading us to describe these species as 'fuzzy'. Conclusion A multilocus approach using large samples of closely related isolates delineates species even in the highly recombinogenic human Neisseria where individual loci are inadequate for the task. This approach should be applied by taxonomists to large samples of other groups of closely-related bacteria, and especially to those where species delineation has historically been difficult, to determine whether genotypic clusters can be delineated, and to guide the definition of species.

  4. Tetracycline and oxytetracycline resistance determinants detected in Bacillus cereus strains isolated from honey samples Detección de determinantes de resistencia a tetraciclina y oxitetraciclina en cepas de Bacillus cereus aisladas de muestras de miel

    Directory of Open Access Journals (Sweden)

    A. C. López

    2008-12-01

    oxitetraciclina en las poblaciones de Bacillus cereus presentes en la miel. De un total de 77 aislamientos evaluados, 30 (39% resultaron resistentes a tetraciclina y/o minociclina de acuerdo con los resultados de las pruebas de difusión en disco. Dentro del grupo que presentó un fenotipo resistente, se investigó la presencia de los determinantes tetK, tetL, tetM, tetO, tetW, otrA y otrB por PCR y se determinaron los valores de CIM para tetraciclina, oxitetraciclina y minociclina. De acuerdo con los resultados obtenidos por PCR, 23 aislamientos (77% presentaron al menos un determinante de resistencia a tetraciclina o a oxitetraciclina; el genotipo tetK se encontró en 10 de esos aislamientos, mientras que los genotipos tetL, tetM y otrA se hallaron en 3, 2 y 5 aislamientos, respectivamente. Ningún aislamiento presentó los genotipos tetW, tetO ni otrB. Adicionalmente, se encontraron los genotipos tetK plus tetM (2 aislamientos; tetK plus tetL (1 aislamiento y tetK plus otrA (1 aislamiento. Por otra parte, 7 cepas (23% resultaron resistentes a tetraciclina, oxitetraciclina y/o minociclina por CIM, pero no presentaban ninguno de los determinantes tet u otr estudiados. Estos resultados indican la existencia de un alto porcentaje de cepas de B. cereus aisladas de miel con genes de resistencia a tetraciclina y oxitetraciclina, incluyendo los determinantes tetK, tetL, tetM y otrA. Este estudio constituye el primer registro de la presencia del determinante tetK de resistencia a tetraciclina en B. cereus, como así también la presencia del determinante otrA dentro del género Bacillus.

  5. Caracterización por PCR- múltiple del grupo filogenético de Escherichia coli uropatógena aisladas de pacientes ambulatorios de Bucaramanga, Santander

    Directory of Open Access Journals (Sweden)

    Alexandra Serrano

    2016-06-01

    Full Text Available Introducción: Las infecciones del tracto urinario son consideradas actualmente como una de las enfermedades infecciosas más comunes. En general se acepta que los agentes infecciosos con los cuales se asocia se encuentran presentes en la microbiota intestinal, por tal razón se ha descrito que Escherichia coli es una de las principales Enterobacterias involucradas en las manifestaciones clínicas presentes en pacientes con infecciones del tracto urinario. Las cepas de E. coli han sido clasificadas inicialmente en 4 grupos filogenéticos según Clermont y col. (2000, de este modo se conocen “cepas intestinales comensales, pertenecientes a los grupos A y B1, y cepas extra intestinales virulentas asociadas a los grupos B2 y D, para llevar a cabo dicha clasificación Clermont, diseñó herramientas moleculares como la PCR-triple, mediante la utilización de diferentes genes tales como ChuA, yjaA y TSPE4.C2”. Sin embargo debido a la complejidad estructural genética de este microorganismo, se han logrado establecer nuevos grupos filogenéticos de E. coli, A, B1, B2, C, D, E, F y un último grupo el cual no ha sido completamente identificado, por tal razón es importante conocer cuáles son los grupos filogenéticos que están presentes en nuestra región, mediante el uso de técnicas moleculares que permitan realizar la caracterización filogenética de dicho microorganismo y de esta manera lograr establecer los perfiles de resistencia y evaluar los posibles factores de virulencia asociados al proceso de infección. Objetivo: Realizar la caracterización molecular de los grupos filogenéticos de E. coli uropatógena aislada de pacientes ambulatorios que asisten a un laboratorio de tercer nivel de complejidad de la ciudad de Bucaramanga mediante el uso de PCR-multiplex. Materiales y métodos: El cálculo del tamaño muestral se realizó teniendo en cuenta la prevalencia reportada por Orduz, K y Trejos, J, (2010, se calculó el tamaño de muestra

  6. Cultivos primarios de células endoteliales aisladas de cordón umbilical humano: un modelo biológico para el estudio de los mecanismos de infección por enterococos.

    Directory of Open Access Journals (Sweden)

    Carlos Andrés Chiriboga

    2004-12-01

    Full Text Available Aunque las especies de enterococos son flora normal del tracto gastrointestinal humano, se encuentran entre los tres agentes patógenos microbianos que más se asocian con infecciones intrahospitalarias. Tradicionalmente, los enterococos se han considerado bacterias extracelulares. Sin embargo, es creciente la información que reporta su ingreso a través de líneas celulares epiteliales o macrófagos. A pesar de que estos microorganismos constituyen el tercer grupo de aislamientos obtenido de pacientes con bacteriemia o endocarditis, su interacción con la célula endotelial no se ha descrito completamente. En el presente trabajo evaluamos si el aislamiento intrahospitalario de Enterococcus faecalis (Ef2880 podía penetrar en células endoteliales de la vena de cordón umbilical humano (HUVEC cultivadas in vitro. Nuestros resultados indican que los cultivos primarios HUVEC después de ser inoculados con Ef2890, incubados y tratados con antibióticos bactericidas para las bacterias extracelulares y adheridas a la cara externa de la membrana celular, exhiben bacterias intracelulares que pueden ser recuperadas vivas cuatro horas después de la inoculación. El modelo biológico desarrollado se puede constituir en una herramienta útil para el estudio de las interacciones que establecen los enterococos con el endotelio.

  7. Identificación de bacterias productoras de Polihidroxialcanoatos (PHAs en suelos contaminados con desechos de fique

    Directory of Open Access Journals (Sweden)

    Silvia Alexandra Sánchez Moreno

    2012-07-01

    Full Text Available Título en ingles: Identification of polyhydroxyalkanoate-producing bacteria in soils contaminated with fique wastes Resumen: Los Polihidroxialcanoatos (PHAs son biopolímeros con características similares a los plásticos sintéticos, pero rápidamente biodegradables dado su origen microbiano. En esta investigación se aislaron 248 colonias bacteriales de suelos contaminados con residuos del beneficio de fique en Guarne (Antioquia, evaluándose su capacidad como productoras de PHAs. Se realizaron tinciones con rojo y azul de Nilo y detección por PCR del gen PhaC. Las bacterias positivas a dichas pruebas, fueron identificadas utilizando análisis filogenético de secuencias de 16S del ADNr y pruebas bioquímicas. Finalmente, se evaluó, mediante cromatografía de gases con detector selectivo de masas GC-MS/SIM, la naturaleza química del biopolímero, a partir de la biomasa generada en un ensayo de fermentación en cultivo sumergido, con medio mínimo de sales suplementado con glucosa como fuente de carbono. Cuatro cepas de los morfotipos bacteriales encontrados, presentaron potencial para producir PHAs, de los cuales dos fueron identificados como miembros de la especie Bacillus megaterium, uno como B. mycoides y el otro como Gordonia sp. El gen PhaC se detectó en los dos aislamientos de B. megaterium. El análisis cromatográfico permitió detectar al Polihidroxibutirato (PHB como el principal componente de los PHAs presentes en B. megaterium, cuantificándose entre 63.8 mg/g y 95.3 mg/g de PHB en los ensayos de fermentación. Las bacterias aisladas tienen potencial en la producción de PHAs a partir de residuos agroindustriales, incluyendo el jugo de fique, lo que contribuiría a la reducción de su condición contaminante. Palabras clave: ADNr 16S; Bacillus; biopolímeros; Furcraea bedinghausii; PhaC. Abstract: Polyhydroxyalkanoates (PHAs are biodegradable biopolymers of bacterial origin with properties similar to conventional plastics. In

  8. Drinking Water Fact Sheet: Coliform Bacteria

    OpenAIRE

    Mesner, Nancy; Daniels, Barbara

    2010-01-01

    This fact sheet provides information about coliform bacteria. Including sections about what coliform bacteria is, how it enters drinking water, health concerns from exposure, drinking water standards, and how to treat drinking water that contains coliforms.

  9. Killer Pigments in Bacteria: An Ecological Nightmare.

    Science.gov (United States)

    Benathen, Isaiah A.; Saccardi, Marion

    2000-01-01

    Describes an alternative to teaching ecology by using bacteria to test competitor survival. Students observe a time-dependent selective killing of other unrelated bacteria by Pseudomonas aeruginosa. (SAH)

  10. Viability of bacteria in peatlands

    Science.gov (United States)

    Bogdanova, O. Yu.; Golovchenko, A. V.; Lysak, L. V.; Glukhova, T. V.; Zvyagintsev, D. G.

    2014-04-01

    The viability of bacteria in oligotrofic bogs and fens was determined by the luminescent microscopy method with the help of a two-component fluorescent dye (L7012 LIVE/DEAD). Living bacterial cells were found in the entire peat profiles. Their portion was maximal (up to 60%) in the upper layers and did not exceed 25% in the lower layers. The portion of dead bacterial cells varied from 3 to 19%, and dormant cells constituted 25 to 95% of the total number of bacterial cells. The numbers of dormant cells increased down the profiles irrespectively of the peat type. The portion of nanoforms did not exceed 5% of the total. The cells of the nanoforms, unlike the bacteria of typical sizes, were characterized by their high viability (93-98%).

  11. Genetics of Lactic Acid Bacteria

    Science.gov (United States)

    Zagorec, Monique; Anba-Mondoloni, Jamila; Coq, Anne-Marie Crutz-Le; Champomier-Vergès, Marie-Christine

    Many meat (or fish) products, obtained by the fermentation of meat originating from various animals by the flora that naturally contaminates it, are part of the human diet since millenaries. Historically, the use of bacteria as starters for the fermentation of meat, to produce dry sausages, was thus performed empirically through the endogenous micro-biota, then, by a volunteer addition of starters, often performed by back-slopping, without knowing precisely the microbial species involved. It is only since about 50 years that well defined bacterial cultures have been used as starters for the fermentation of dry sausages. Nowadays, the indigenous micro-biota of fermented meat products is well identified, and the literature is rich of reports on the identification of lactic acid bacteria (LAB) present in many traditional fermented products from various geographical origin, obtained without the addition of commercial starters (See Talon, Leroy, & Lebert, 2007, and references therein).

  12. Copper resistance determinants in bacteria.

    Science.gov (United States)

    Brown, N L; Rouch, D A; Lee, B T

    1992-01-01

    Copper is an essential trace element that is utilized in a number of oxygenases and electron transport proteins, but it is also a highly toxic heavy metal, against which all organisms must protect themselves. Known bacterial determinants of copper resistance are plasmid-encoded. The mechanisms which confer resistance must be integrated with the normal metabolism of copper. Different bacteria have adopted diverse strategies for copper resistance, and this review outlines what is known about bacterial copper resistance mechanisms and their genetic regulation.

  13. Box-shaped halophilic bacteria.

    OpenAIRE

    Javor, B; Requadt, C; Stoeckenius, W

    1982-01-01

    Three morphologically similar strains of halophilic, box-shaped procaryotes have been isolated from brines collected in the Sinai, Baja California (Mexico), and southern California (United States). Although the isolates in their morphology resemble Walsby's square bacteria, which are a dominant morphological type in the Red Sea and Baja California brines, they are probably not identical to them. The cells show the general characteristics of extreme halophiles and archaebacteria. They contain ...

  14. Fungal inhibitory lactic acid bacteria

    OpenAIRE

    Ström, Katrin

    2005-01-01

    Lactic acid bacteria (LAB) are microorganisms that have been used for centuries to prepare and improve storage of food and for ensiling of different crops for animal feed. This thesis explores the possibility of using LAB to inhibit growth of spoilage fungi in food and feed products. LAB isolates, collected from plant material or dairy products, were screened for antifungal activity in a dual culture assay. Strains with antifungal activity were identified and the fungal inhibitory activity wa...

  15. Re-engineering bacteria for ethanol production

    Science.gov (United States)

    Yomano, Lorraine P; York, Sean W; Zhou, Shengde; Shanmugam, Keelnatham; Ingram, Lonnie O

    2014-05-06

    The invention provides recombinant bacteria, which comprise a full complement of heterologous ethanol production genes. Expression of the full complement of heterologous ethanol production genes causes the recombinant bacteria to produce ethanol as the primary fermentation product when grown in mineral salts medium, without the addition of complex nutrients. Methods for producing the recombinant bacteria and methods for producing ethanol using the recombinant bacteria are also disclosed.

  16. Oligotrophic bacteria isolated from clinical materials.

    OpenAIRE

    Tada, Y; Ihmori, M; Yamaguchi, J

    1995-01-01

    Oligotrophic bacteria (oligotrophs) are microorganisms that grow in extremely nutritionally deficient conditions in which the concentrations of organic substances are low. Many oligotrophic bacteria were isolated from clinical materials including urine, sputum, swabbings of the throat, vaginal discharges, and others. Seventy-seven strains of oligotrophic bacteria from 871 samples of clinical material were isolated. A relatively higher frequency of isolation of oligotrophic bacteria was shown ...

  17. La anaerobiosis más allá de las bacterias anaerobias: su importancia en la recuperación de microorganismos aerobios a partir de materiales purulentos Anaerobiosis beyond anaerobic bacteria: Its role in the recovery of aerobic microorganisms from purulent samples

    Directory of Open Access Journals (Sweden)

    M.R. Litterio Bürki

    2010-06-01

    Full Text Available El objetivo fundamental de la incubación en anaerobiosis es la recuperación de bacterias anaerobias obligadas, aunque ésta no excluye la recuperación de otros microorganismos. En el año 2003 iniciamos un estudio prospectivo y comparativo de los microorganismos aerobios recuperados a partir de la siembra primaria de muestras clínicas consecutivas en anaerobiosis y de aquellos recuperados a partir de la siembra primaria de las mismas muestras en aerobiosis. Los objetivos fueron evaluar el rendimiento de la metodología empleada en anaerobiosis en la recuperación de microorganismos aerobios no diagnosticados a partir de la siembra primaria en aerobiosis y establecer la relación entre éstos y el origen de la muestra. En el período 2003-2004 se procesaron 2776 muestras. Se recuperaron 1884 microorganismos aerobios; el 69,4% desarrolló tanto en condiciones aerobias como anaerobias, mientras que el 30,6% restante sólo lo hizo en una de las dos atmósferas: el 49,2% sólo en aerobiosis y el 50,8% sólo en anaerobiosis. La metodología empleada para los cultivos primarios en anaerobiosis (incubación anaerobia, medios de cultivo, lupa o microscopio estereoscópico para examinar las placas primarias, etc. permitió la recuperación de microorganismos aerobios, en particular de cocos gram positivos (microaerófilos y facultativos no diagnosticados a partir del cultivo primario en aerobiosis. Este rendimiento extra fue más evidente en materiales con flora polimicrobiana, especialmente gram negativa, e independiente del tipo de muestra estudiada.The main objective of incubation in anaerobiosis is the recovery of obligate anaerobic bacteria, not excluding other microorganisms. In 2003, we conducted a comparative and prospective study from consecutive clinical samples on the recovery of aerobic microorganisms from primary cultures both in anaerobiosis and aerobiosis of the same sample. The aims were to evaluate the methodology used in anaerobiosis

  18. Laser-Based Identification of Pathogenic Bacteria

    Science.gov (United States)

    Rehse, Steven J.

    2009-01-01

    Bacteria are ubiquitous in our world. From our homes, to our work environment, to our own bodies, bacteria are the omnipresent although often unobserved companions to human life. Physicists are typically untroubled professionally by the presence of these bacteria, as their study usually falls safely outside the realm of our typical domain. In the…

  19. Bacteria interfere with A-actinomycetemcomitans colonization

    OpenAIRE

    Teughels, Wim; Haake, S. Kinder; Sliepen, Isabelle; Pauwels, Martine; Van Eldere, Johan; Cassiman, Jean-Jacques; Quirynen, Marc

    2007-01-01

    It is known that beneficial bacteria can suppress the emergence of pathogenic bacteria, particularly in the gastrointestinal tract. This study examined the potential for a similar suppression of Aggregatibacter (formerly Actinobacillus) actinomycetemcomitans colonization of epithelial cells, due to its potential relevance in periodontal diseases. Seven presumed beneficial bacteria were examined for their ability to interfere, exclude, or displace A. actinomycetemcomitans from epithelial cells...

  20. Current strategies for improving food bacteria

    NARCIS (Netherlands)

    Kuipers, O P; Buist, Girbe; Kok, Jan

    2000-01-01

    Novel concepts and methodologies are emerging that hold great promise for the directed improvement of food-related bacteria, specifically lactic acid bacteria. Also, the battle against food spoilage and pathogenic bacteria can now be fought more effectively. Here we describe recent advances in

  1. AIDS: "it's the bacteria, stupid!".

    Science.gov (United States)

    Broxmeyer, Lawrence; Cantwell, Alan

    2008-11-01

    Acid-fast tuberculous mycobacterial infections are common in AIDS and are regarded as secondary "opportunistic infections." According to the National Institute of Allergy and Infectious Diseases, TB is the major attributable cause of death in AIDS patients. Could such bacteria play a primary or causative role in AIDS? Certainly, In screening tests for HIV, there is frequent, up to 70%, cross-reactivity, between the gag and pol proteins of HIV and patients with mycobacterial infections such as tuberculosis. By 1972, five years before gays started dying in the U.S., Rolland wrote Genital Tuberculosis, a Forgotten Disease? And ironically, in 1979, on the eve of AIDS recognition, Gondzik and Jasiewicz showed that even in the laboratory, genitally infected tubercular male guinea pigs could infect healthy females through their semen by an HIV-compatible ratio of 1 in 6 or 17%, prompting him to warn his patients that not only was tuberculosis a sexually transmitted disease, but also the necessity of the application of suitable contraceptives, such as condoms, to avoid it. Gondzik's solution and date of publication are chilling; his findings significant. Since 1982 Cantwell et al found acid-fast bacteria closely related to tuberculosis (TB) and atypical tuberculosis in AIDS tissue. On the other hand molecular biologist and virologist Duesberg, who originally defined retroviral ultrastructure, has made it clear that HIV is not the cause of AIDS and that the so-called AIDS retrovirus has never been isolated in its pure state. Dr. Etienne de Harven, first to examine retroviruses under the electron, agrees. In 1993 HIV co-discoverer Luc Montagnier reported on cell-wall-deficient (CWD) bacteria which he called "mycoplasma" in AIDS tissue. He suspected these as a necessary "co-factor" for AIDS. Remarkably, Montagnier remained silent on Cantwell's reports of acid-fast bacteria which could simulate "mycoplasma" in AIDS tissue. Mattman makes clear that the differentiation between

  2. Potential role of bacteria packaging by protozoa in the persistence and transmission of pathogenic bacteria

    OpenAIRE

    Denoncourt, Alix M.; Paquet, Valérie E.; Charette, Steve J.

    2014-01-01

    Many pathogenic bacteria live in close association with protozoa. These unicellular eukaryotic microorganisms are ubiquitous in various environments. A number of protozoa such as amoebae and ciliates ingest pathogenic bacteria, package them usually in membrane structures, and then release them into the environment. Packaged bacteria are more resistant to various stresses and are more apt to survive than free bacteria. New evidence indicates that protozoa and not bacteria control the packaging...

  3. Efecto de bacterias probióticas en el cultivo larvario del ostión de placer Crassostrea corteziensis (Bivalvia: Ostreidae

    Directory of Open Access Journals (Sweden)

    Angel Isidro Campa-Córdova

    2011-03-01

    Full Text Available El ostión de placer u ostra del Cortés (Crassostrea corteziensis se considera como una especie con potencial para ser cultivada en gran escala. Sin embargo, al igual que en otros bivalvos, la alta mortalidad que se presenta durante la etapa larvaria y juvenil, es el principal problema que limita el desarrollo del cultivo en el laboratorio. Un método que está ganando aceptación en la acuicultura es el uso de bacterias probióticas para controlar patógenos microbianos. Este estudio analiza el efecto de estas bacterias en la supervivencia y talla final de larvas de ostión de placer Crassostrea corteziensis. Se utilizó una cepa de bacterias ácido lácticas (cepa NS61 aisladas N. subnodosus, así como de bacilos aislados de L. vannamei (Pseudomonas aeruginosa, cepa YC58 y de C. corteziensis (Burkholderia cepacia, cepa Y021. Las cepas se evaluaron por inmersión en cultivos larvarios de C. corteziensis a dos concentraciones diferentes, hasta completar el estadio pediveliger. Los organismos se trataron con bacterias ácido lácticas (Lb, una mezcla de bacilos (Lb en proporción 1:1 y un grupo control. La concentración de 1x10(4UFC/ml registró una mayor supervivencia con Lb y Mb respecto al grupo control. La supervivencia con Mb a una concentración de 1x10(5UFC/ml fue mayor que la del grupo control y del grupo tratado con Lb. Los resultados mostraron que las larvas de C. corteziensis tratadas con probióticos no incrementaron significativamente su talla respecto a las larvas del grupo control. Mientras que las tratadas con Lb a la concentración mayor, 1x10(5UFC/ml, mostraron una disminución de la supervivencia respecto a las tratadas con 1x10(4UFC/ml. Este estudio demostró el efecto benéfico de cepas probióticas utilizadas individualmente o en mezcla en el cultivo larvario de C. corteziensis.

  4. Effect of D-004, a lipid extract from royal palm (Roystonea regia fruits, on phenylephrine-induced contractions of isolated rat prostate Efecto de D-004, un extracto lipídico extraído de las frutas de la palma real (Roystonea regia sobre las contracciones provocadas por la Fenilefrina sobre la próstata aislada de rata

    Directory of Open Access Journals (Sweden)

    Lourdes Arruzazabala Valmaña

    2009-12-01

    Full Text Available D-004, un extracto lipídico de las frutas de Roystonea regia, inhibe la contracción provocada por la norepinefrina en el vas deferens de las ratas. No obstante, el efecto de D-004 sobre las respuestas contráctiles adrenérgicas a1 en las preparaciones aisladas de la próstata no ha sido estudiado. Por lo tanto, este estudio investigó los efectos de D-004 sobre las contracciones provocadas por la fenilefrina en las extracciones aisladas de la próstata de la rata. D-004 (125-500 mg/mL fue adicionado a las preparaciones a partir de la próstata en la que las contracciones fueron provocadas por la fenilefrina (10-6-10-4 M o por CIK (50 mM. D-004 (250-500 mg/mL en forma significativa y la dosis en forma dependiente inhibieron las contracciones provocadas por la fenilefrina mediante un mecanismo no competetitivo, reduciendo así (12-60 % la contracción máxima por la fenilefrina con respecto a las preparaciones controles. D-004 a 500 µg/mL inhibieron de la misma forma tanto CIK como las respuestas contráctiles-fenilefrina. Tamsulosin (0,01 mg/mL eliminó la acción de la fenilefrina (100 % de inhibición, pero no afectó las contracciones provocadas por CIK.D-004, a lipid extract of Roystonea regia fruits, inhibits norepinephrine-elicited contraction in rat vas deferens. Nevertheless, the effect of D-004 on a1-adrenergic contractile responses in isolated prostate preparations had not been studied. Therefore, this study investigated the effects of D-004 on phenylephrine-induced contractions in isolated rat prostate strips. D-004 (125-500 mg/mL was added to prostate preparations in which contractions were induced with phenylephrine (10-6-10-4 M or with ClK (50 mM. D-004 (250-500 mg/mL significantly (p < 0,01.and dose-dependently inhibited the phenylephrine-induced contractions through a non-competitive mechanism, since it reduced (12-60 % the maximal contraction to phenyle phrine with respect to control preparations. D-004 at 500 mg/mL inhibited

  5. Bacteria detection instrument and method

    Science.gov (United States)

    Renner, W.; Fealey, R. D. (Inventor)

    1972-01-01

    A method and apparatus for screening a sample fluid for bacterial presence are disclosed wherein the fluid sample is mixed with culture media of sufficient quantity to permit bacterial growth in order to obtain a test solution. The concentration of oxygen dissolved in the test solution is then monitored using the potential difference between a reference electrode and a noble metal electrode which are in contact with the test solution. The change in oxygen concentration which occurs during a period of time as indicated by the electrode potential difference is compared with a detection criterion which exceeds the change which would occur absent bacteria.

  6. Bacteria and vampirism in cinema.

    Science.gov (United States)

    Castel, O; Bourry, A; Thévenot, S; Burucoa, C

    2013-09-01

    A vampire is a non-dead and non-alive chimerical creature, which, according to various folklores and popular superstitions, feeds on blood of the living to draw vital force. Vampires do not reproduce by copulation, but by bite. Vampirism is thus similar to a contagious disease contracted by intravascular inoculation with a suspected microbial origin. In several vampire films, two real bacteria were staged, better integrated than others in popular imagination: Yersinia pestis and Treponema pallidum. Bacillus vampiris was created for science-fiction. These films are attempts to better define humans through one of their greatest fears: infectious disease. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  7. RESISTENCIA A LOS ANTIBIÓTICOS EN CEPAS DE KLEBSIELLA PNEUMONIAE, SERRATIA SPP. Y ACINETOBACTER SPP.AISLADAS DE PACIENTES CON INFECCIÓN DEL TRACTO URINARIO - LIMA, PERU

    Directory of Open Access Journals (Sweden)

    Luján Roca DA

    2013-01-01

    Full Text Available INFECTION - LIMA, PERU Introduction: Urinary tract infection (UTI is one of the most common infections in clinical practice. Gram negative bacteria as Klebsiella pneumoniae, Serratia spp. and Acinetobacter spp. can cause UTI. Objective: To study antibiotic resistance in K. pneumoniae, Serratia spp. and Acinetobacter spp. strains isolated from UTI Material and methods: Urine cultures were collected from January 2003 to December 2003. Identification of isolated bacteria included biochemical characteristics. Bauer-Kirby disc diffusion test was performed. Results: A total of 106 strains were evaluated (41 of K. pneumoniae, 28 of Serratia spp. and 37 of Acinetobacter spp.. Among K. pneumoniae isolates resistance to ampicillin (83% was remarkable. The Serratia spp. isolates displayed a high level of resistance to nalidixic acid (79% and gentamicin (75%. In Acinetobacter spp. isolates high resistance rates were observed against amikacin (81%, gentamicin (67% and trimethoprim/sulfamethoxazole(71%. Conclusions: In general, antibiotic resistance patterns were high. Acinetobacter spp. showed elevated resistance rates (>50% against antibiotics included.

  8. Antibiotic- and heavy-metal resistance in bacteria isolated from deep subsurface in El Callao region, Venezuela

    Directory of Open Access Journals (Sweden)

    Maura Lina Rojas Pirela

    2014-07-01

    Full Text Available Título en ingles: Antibiotic- and heavy-metal resistance in bacteria isolated from deep subsurface in El Callao region, Venezuela Título corto: Antibiotic and metal resistance in bacteria from deep subsurface Título en español: Resistencia a antibioticos y metals pesados en bacterias aisladas de subsuelo en la región El Callao, Venezuela Resumen:  Se investigó el efecto de la contaminación con mercurio (Hg en las comunidades bacterianas del subsuelo profundo en la región de El Callao (Estado Bolívar, Venezuela. Se estudiaron comunidades bacterianas de dos niveles de profundidad (-288 m y -388 m en una mina de oro con el propósito de describir las características más relevantes de las bacterias indígenas cultivables que colonizaban esta mina. Se evaluaron los patrones de resistencia a antibióticos y metales pesados, presencia del gen merA y plásmidos en aislados resistentes. Se encontró una elevada frecuencia de bacterias indígenas resistentes al Hg y otros metales pesados. De 76 aislados Hg-resistentes probados 73.7 % fueron adicionalmente resistentes a ampicilina; 86.8 % a cloranfenicol; 67.1 % a tetraciclina; 56.6 % a estreptomicina y 51.3 % a kanamicina. Además, se encontró que 40.74 % (-328 m y 26.53 % (-388 m de las bacterias Hg-resistentes fueron simultáneamente resistentes tanto a cuatro como a cinco de estos antibióticos. Se detectó la presencia de plásmidos de alto y bajo peso molecular y, a pesar de que los aislados mostraban resistencia a compuestos mercuriales, la presencia del gen merA fue detectada solo en 71.05 % de los cepas. Estos resultados sugieren que la exposición a Hg podría ser una presión selectiva en la proliferación de bacterias resistentes a antibióticos y promover el mantenimiento y propagación de estos genes de resistencia. Sin embargo, la existencia de tales resistencias a estas profundidades podría también apoyar la idea de que la resistencia a antibióticos en estas bacterias es

  9. Money and transmission of bacteria.

    Science.gov (United States)

    Gedik, Habip; Voss, Timothy A; Voss, Andreas

    2013-08-28

    Money is one of the most frequently passed items in the world. The aim of this study was to ascertain the survival status of bacteria including Staphylococcus aureus, Escherichia coli, and Vancomycin- Resistant Enterococci (VRE) on banknotes from different countries and the transmission of bacteria to people who come in contact with the banknotes. The survival rate was highest for the Romanian Leu yielding all three microorganisms used after both three and six hours of drying. Furthermore, the Leu was the only banknote to yield VRE after one day of drying. Other currencies either enabled the survival of Extended-Spectrum Beta-Lactamases (ESBL) and VRE (e.g. Euro), but not of MRSA, or the other way round (e.g. US Dollar). While a variety of factors such as community hygiene levels, people's behaviour, and antimicrobial resistance rates at community level obviously have influence on the transmission of resistant microorganisms, the type of banknote-paper may be an additional variable to consider.

  10. Differential scanning calorimetry of bacteria.

    Science.gov (United States)

    Miles, C A; Mackey, B M; Parsons, S E

    1986-04-01

    Thermograms obtained by differential scanning calorimetry of a range of bacteria of different heat resistances were compared. Equations were derived to calculate the rate at which the numbers of viable organisms in a calorimeter decline as the temperature is raised at a constant rate. Vegetative bacteria scanned at 10 degrees C min-1 showed multi-peaked thermograms with four major peaks (denoted m, n, p and q) occurring in the regions 68-73, 77-84, 89-99 and 105-110 degrees C respectively. Exceptions were that peak m (the largest peak) occurred at 79-82 degrees C in Bacillus stearothermophilus and an additional peak, r, was detected in Escherichia coli at 119 degrees C. At temperatures below the main peak m there were major differences in thermograms between species. There was a direct relationship between the onset of thermal denaturation and the thermoresistance of different organisms. Heat-sensitive organisms displayed thermogram features which were absent in the more heat-resistant types. When samples were cooled to 5 degrees C and re-heated, a small endothermic peak, pr, was observed at the same temperature as p. Peaks p and pr were identified as the melting endotherms of DNA. In all vegetative organisms examined, maximum death rates, computed from published D and z values, occurred at temperatures above the onset of thermal denaturation, i.e. cell death and irreversible denaturation of cell components occurred within the same temperature range.

  11. Efecto de bacterias probióticas en el cultivo larvario del ostión de placer Crassostrea corteziensis (Bivalvia: Ostreidae

    Directory of Open Access Journals (Sweden)

    Angel Isidro Campa-Córdova

    2011-03-01

    Full Text Available El ostión de placer u ostra del Cortés (Crassostrea corteziensis se considera como una especie con potencial para ser cultivada en gran escala. Sin embargo, al igual que en otros bivalvos, la alta mortalidad que se presenta durante la etapa larvaria y juvenil, es el principal problema que limita el desarrollo del cultivo en el laboratorio. Un método que está ganando aceptación en la acuicultura es el uso de bacterias probióticas para controlar patógenos microbianos. Este estudio analiza el efecto de estas bacterias en la supervivencia y talla final de larvas de ostión de placer Crassostrea corteziensis. Se utilizó una cepa de bacterias ácido lácticas (cepa NS61 aisladas N. subnodosus, así como de bacilos aislados de L. vannamei (Pseudomonas aeruginosa, cepa YC58 y de C. corteziensis (Burkholderia cepacia, cepa Y021. Las cepas se evaluaron por inmersión en cultivos larvarios de C. corteziensis a dos concentraciones diferentes, hasta completar el estadio pediveliger. Los organismos se trataron con bacterias ácido lácticas (Lb, una mezcla de bacilos (Lb en proporción 1:1 y un grupo control. La concentración de 1x10(4UFC/ml registró una mayor supervivencia con Lb y Mb respecto al grupo control. La supervivencia con Mb a una concentración de 1x10(5UFC/ml fue mayor que la del grupo control y del grupo tratado con Lb. Los resultados mostraron que las larvas de C. corteziensis tratadas con probióticos no incrementaron significativamente su talla respecto a las larvas del grupo control. Mientras que las tratadas con Lb a la concentración mayor, 1x10(5UFC/ml, mostraron una disminución de la supervivencia respecto a las tratadas con 1x10(4UFC/ml. Este estudio demostró el efecto benéfico de cepas probióticas utilizadas individualmente o en mezcla en el cultivo larvario de C. corteziensis.Effect of probiotic bacteria on survival and growth of Cortez oyster larvae, Crassostrea corteziensis (Bivalvia: Ostreidae. Disease control

  12. Sulfur metabolism in phototrophic sulfur bacteria

    DEFF Research Database (Denmark)

    Frigaard, Niels-Ulrik; Dahl, Christiane

    2008-01-01

    Phototrophic sulfur bacteria are characterized by oxidizing various inorganic sulfur compounds for use as electron donors in carbon dioxide fixation during anoxygenic photosynthetic growth. These bacteria are divided into the purple sulfur bacteria (PSB) and the green sulfur bacteria (GSB......). They utilize various combinations of sulfide, elemental sulfur, and thiosulfate and sometimes also ferrous iron and hydrogen as electron donors. This review focuses on the dissimilatory and assimilatory metabolism of inorganic sulfur compounds in these bacteria and also briefly discusses these metabolisms...... in other types of anoxygenic phototrophic bacteria. The biochemistry and genetics of sulfur compound oxidation in PSB and GSB are described in detail. A variety of enzymes catalyzing sulfur oxidation reactions have been isolated from GSB and PSB (especially Allochromatium vinosum, a representative...

  13. Transformation of gram positive bacteria by sonoporation

    Science.gov (United States)

    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.

  14. Beneficial interactions between insects and gut bacteria

    OpenAIRE

    Rajagopal, R.

    2009-01-01

    Insects are amongst the most successful of animals, both in terms of diversity and in colonizing all ecological niches. Recent studies have highlighted the benefi ciary roles that bacteria play in the success and establishment of insects. By adopting techniques like 16S rRNA sequencing we are now in a position to understand the diversity of bacteria present in insect guts. It has been shown that some of these bacteria, like Wolbachia and Cardinium are involved in manipulating insect populatio...

  15. Magnetotactic bacteria at the geomagnetic equator

    International Nuclear Information System (INIS)

    Frankel, R.B.; Blakemore, R.P.; Araujo, F.F.T. de; Esquivel, D.M.S.; Danon, J.

    1981-01-01

    Magnetotatic bacteria are observed in freshwater and marine sediments of Fortaleza, Brazil, situated close to the geomagnetic equator. Both South-seeking and North-seeking bacteria are present in roughly equal numbers in the same samples. This observation is consistent with the hypothesis that the vertical component of the geomagnetic field selects the predominant polarity type among magnetotactic bacteria in natural environments. (Author) [pt

  16. Antioxidant Properties of Probiotic Bacteria.

    Science.gov (United States)

    Wang, Yang; Wu, Yanping; Wang, Yuanyuan; Xu, Han; Mei, Xiaoqiang; Yu, Dongyou; Wang, Yibing; Li, Weifen

    2017-05-19

    Oxidative stress defines a condition in which the prooxidant-antioxidant balance in the cell is disturbed, resulting in DNA hydroxylation, protein denaturation, lipid peroxidation, and apoptosis, ultimately compromising cells' viability. Probiotics have been known for many beneficial health effects, and the consumption of probiotics alone or in food shows that strain-specific probiotics can present antioxidant activity and reduce damages caused by oxidation. However, the oxidation-resistant ability of probiotics, especially the underling mechanisms, is not properly understood. In this view, there is interest to figure out the antioxidant property of probiotics and summarize the mode of action of probiotic bacteria in antioxidation. Therefore, in the present paper, the antioxidant mechanisms of probiotics have been reviewed in terms of their ability to improve the antioxidant system and their ability to decrease radical generation. Since in recent years, oxidative stress has been associated with an altered gut microbiota, the effects of probiotics on intestinal flora composition are also elaborated.

  17. Isolation and characterization of methanogenic bacteria from ...

    African Journals Online (AJOL)

    Isolation and characterization of methanogenic bacteria from brewery wastewater in Kenya. Sylvia Injete Murunga, Duncan Onyango Mbuge, Ayub Njoroge Gitau, Urbanus Ndungwa Mutwiwa, Ingrid Namae Wekesa ...

  18. 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...

  19. Aislamiento, selección y caracterización de bacterias ácido lácticas en ensilajes de soya

    Directory of Open Access Journals (Sweden)

    Carlos Tobía

    2003-01-01

    Full Text Available Plantas enteras de soya (Glycine max L. Merr., cosechadas en el estado R6 (semillas completamente llenas y seccionadas en trozos de aproximadamente 2 cm. fueron ensiladas en microsilos de 1 kg, con y sin deshidratación parcial (DP; a los silos se les añadió 0, 4, y 8% de melaza de caña azúcar. Se observó una respuesta lineal (P≤ 0,0001 en la disminución del pH concomitantemente con el incremento en la concentración de melaza. Del mismo modo, los contenidos de materia seca (MS se incrementaron al aumentar la concentración de melaza en los ensilajes. La DP concentró en 10 unidades porcentuales el contenido de MS. No se observó interacciones entre la DP y la concentración de melaza. Los aislamientos bacterianos fueron realizados en los microsilos con 4 y 8% de melaza y sin DP, debido a que éstos presentaron las mejores características sensoriales, los menores valores de pH y la menor diversidad de morfotipos bacterianos. Los cultivos se hicieron en agar Rogosa y a las colonias seleccionadas se les efectuó las pruebas de Gram y catalasa; las que correspondieron a bacilos Gram positivos y catalasa negativos, fueron inoculadas en galerias Api 50 CHL®, para su identificación como bacterias ácido lácticas (BAL. Las cepas aisladas correspondieron a Lactobacillus brevis 3.

  20. Coliform bacteria, fabrics, and the environment.

    Science.gov (United States)

    Colclasure, Victoria J; Soderquist, Thomas J; Lynch, Thomas; Schubert, Nina; McCormick, Deirdre S; Urrutia, Erika; Knickerbocker, Corey; McCord, Devon; Kavouras, Jerry H

    2015-02-01

    People come into contact with coliform bacteria at recreational sites. Previous research on bacteria adhering to fabrics and surfaces focused on the viability of clinically significant microbes, but did not examine the quantity of bacteria. This study examined the viability and quantity of coliform bacteria adhered to common fabrics. The fabrics of 100% cotton, blended cotton, and silk were exposed to a mixture of environmental coliform isolates. Fabrics were incubated in the dark at 25°C or 37°C or in direct sunlight at room temperature for 30, 60, 90, and 120 days. The quantity and viability of the bacteria were determined by the Most Probable Number technique using Colilert reagent (IDEXX Laboratories, Westbrook, ME) and eosin methylene blue agar, respectively. The highest numbers of bacteria were detected for each type of fabric when stored in the dark at 25°C, whereas the lowest numbers of bacteria were detected when fabrics were stored in the dark at 37°C. Low numbers of bacteria were detected on silk and blended cotton exposed to sunlight at room temperature, but not 100% cotton. It appears that coliform bacteria can survive on fabrics longer than previous studies have reported. Coliform bacteria survive better in the dark, at lower temperatures, and on fabrics that can retain moisture. These findings can be applied directly to the viability of bacteria on clothing and potential human exposure to fecal pathogens. Copyright © 2015 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  1. Identification of Quorum Quenching Bacteria and Its Biocontrol Potential Against Soft Rot Disease Bacteria, Dickeya Dadantii

    OpenAIRE

    Khoiri, Syaiful; Damayanti, Tri Asmira; Giyanto, Giyanto

    2017-01-01

    Dickeya dadantii is one of newly found bacteria causing soft rot on orchids in Indonesia. Infected plants showed severe rot rapidly only in few days. An effort to control the bacteria was conducted by utilizing selected quorum quenching (QQ) inducer bacteria which produce AHL-lactonase by aiiA gene. The aims of this research were to screen and identify of quorum quenching bacteria, and also assayed their biocontrol potential ability against D. dadantii in laboratory. The screening of QQ bacte...

  2. Characterization of Bacteria Isolation of Bacteria from Pinyon Rhizosphere,

    Science.gov (United States)

    2016-01-01

    Two hundred and fifty bacterial strains were isolated from pinyon rhizosphere and screened for biosurfactants production. Among them, six bacterial strains were selected for their potential to produce biosurfactants using two low cost wastes, crude glycerol and lactoserum, as raw material. Both wastes were useful for producing biosurfactants because of their high content in fat and carbohydrates. The six strains were identified by 16S rDNA with an identity percentage higher than 95%, three strains belonged to Enterobacter sp., Pseudomonas aeruginosa, Bacillus pumilus and Rhizobium sp. All strains assayed were able to grow and showed halos around the colonies as evidence of biosurfactants production on Cetyl Trimethyl Ammonium Bromide agar with crude glycerol and lactoserum as substrate. In a mineral salt liquid medium enriched with both wastes, the biosurfactants were produced and collected from free cell medium after 72 h incubation. The biosurfactants produced reduced the surface tension from 69 to 30 mN/m with an emulsification index of diesel at approximately 60%. The results suggest that biosurfactants produced by rhizosphere bacteria from pinyon have promising environmental applications.

  3. Sensibilidad antimicrobiana y caracterización de cepas de Streptococcus pyogenes aisladas de un brote de escarlatina Antimicrobial sensitivity and typing of Streptococcus pyogenes strains isolated during a scarlet fever outbreak

    Directory of Open Access Journals (Sweden)

    Alberto González Pedraza-Avilés

    2002-09-01

    Full Text Available Objetivo. Evaluar la actividad in vitro de 13 antibióticos contra 47 Streptococcus pyogenes grupo A (SGA. Determinar la presencia de genes que codifican para exotoxina pirogénica estreptocóccica A (SpeA y serotipos con base en proteína M. Material y métodos. Estudio transversal hecho en el Centro de Salud Dr. José Castro Villagrana sobre un brote de escarlatina en el Colegio Espíritu de América, entre diciembre de 1999 y enero de 2000. El número de niños estudiados fue 137. Se extrajeron porcentajes de sensibilidad. La concentración inhibitoria mínima (CIM se obtuvo por microdilución semiautomatizada. Se utilizó un secuenciador automatizado de DNA para el análisis de variación de secuencias en los genes que codifican para proteína M y SpeA. Resultados. Todas las cepas fueron sensibles a beta-lactámicos y clindamicina; 12.7% fueron resistentes a eritromicina. El serotipo M2 fue el más frecuente, 27 del total. Prácticamente todas las bacterias (96% con el gen SpeA tienen el gen que codifica para el serotipo M2. Conclusiones. Debido a la reciente reaparición de infecciones por SGA se sugiere realizar estudios tanto de sensibilidad a macrólidos y beta-lactámicos, como de epidemiología molecular.Objective. To evaluate the in vitro activities of 13 antimicrobial agents against 47 group A Streptococcus pyogenes (GAS strains, and to determine the presence of genes encoding streptococcal pyrogenic exotoxin A (SpeA and the M--protein serotypes. Materials and Methods. A cross-sectional study was conducted at Centro de Salud Dr. José Castro Villagrana, during a scarlet fever outbreak occurring between December 1999 and January 2000, among 137 children at Colegio Espíritu de América. Minimum Inhibitory Concentrations (MICs were obtained by the semiautomated microdilution method. Automated DNA sequencing was used for analysis of sequence variation in genes encoding the M protein, and SpeA. Results. All strains were sensitive to

  4. Rock-degrading endophytic bacteria in cacti

    Science.gov (United States)

    M. Esther Puente; Ching Y. Li; Yoav Bashan

    2009-01-01

    A plant-bacterium association of the cardon cactus (Pachycereus pringlei) and endophytic bacteria promotes establishment of seedlings and growth on igneous rocks without soil. These bacteria weather several rock types and minerals, unbind significant amounts of useful minerals for plants from the rocks, fix in vitro N2. produce...

  5. Comparative Genomics of Green Sulfur Bacteria

    DEFF Research Database (Denmark)

    Ussery, David; Davenport, C; Tümmler, B

    2010-01-01

    Eleven completely sequenced Chlorobi genomes were compared in oligonucleotide usage, gene contents, and synteny. The green sulfur bacteria (GSB) are equipped with a core genome that sustains their anoxygenic phototrophic lifestyle by photosynthesis, sulfur oxidation, and CO(2) fixation. Whole...... weight of 10(6), and are probably instrumental for the bacteria to generate their own intimate (micro)environment....

  6. Resuscitation effects of catalase on airborne bacteria.

    OpenAIRE

    Marthi, B; Shaffer, B T; Lighthart, B; Ganio, L

    1991-01-01

    Catalase incorporation into enumeration media caused a significant increase (greater than 63%) in the colony-forming abilities of airborne bacteria. Incubation for 30 to 60 min of airborne bacteria in collection fluid containing catalase caused a greater than 95% increase in colony-forming ability. However, catalase did not have any effects on enumeration at high relative humidities (80 to 90%).

  7. Lactic Acid Bacteria in the Gut

    NARCIS (Netherlands)

    Stolaki, M.; Vos, de W.M.; Kleerebezem, M.; Zoetendal, E.G.

    2012-01-01

    From all bacterial groups, the lactic acid bacteria (LAB) are probably the group of bacteria that is most associated with human lifestyle. The term LAB mainly refers to the ability of these organisms to convert sugars to lactic acid. The LAB comprise non-sporing, aerotolerant, coccus or rod-shaped,

  8. Isolating bacteria from sponges: Why and How?

    Science.gov (United States)

    Laport, Marinella Silva

    2018-03-28

    It is known that sponge-associated bacteria are an attractive source of new bioactive substances with biotechnological potential. These include antimicrobials, enzymes and surfactants. However, the potential of these microorganisms remains little investigated due to the difficulty of isolating new bacterial groups that produce original bioactive metabolites and enzymes. Cultivation methods are still playing crucial functions in many studies involving bacteria isolated from sponges, and in the traditional approach for biodiscovery by screening culture collections. For instance, culture media which are rich in nutrients favor the fast cultivation in comparison with slower growing bacteria, and diluted and/or poor culture media increase the possibility of growing previously uncultured bacteria. The ability to grow bacteria in culture and to characterize their secondary metabolites are a crucial approach to new biotechnology products of potential value. Many microbial biotechnology compounds used nowadays were extracted from cultured bacteria. This review presents and discusses some strategies to isolate and culture bacteria from sponges for biotechnological exploration. Finally, whole genome sequencing of sponge-associated bacteria is proposed as a novel strategy for biodiscovery. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  9. Energy transduction in lactic acid bacteria

    NARCIS (Netherlands)

    Poolman, Bert

    In the discovery of some general principles of energy transduction, lactic acid bacteria have played an important role. In this review, the energy transducing processes of lactic acid bacteria are discussed with the emphasis on the major developments of the past 5 years. This work not only includes

  10. Role of Outer Membrane Vesicles of Bacteria

    Indian Academy of Sciences (India)

    IAS Admin

    However, not all the surface-associated bacterial toxins mediate binding and internal- ization of the vesicles. Role in Pathogenesis. OMVs are important for pathogenicity and virulence of bacteria. Studies involving various pathogenic bacteria clearly reveal that they produce OMVs within the infected host tissues. Body fluids.

  11. The Microworld of Marine-Bacteria

    DEFF Research Database (Denmark)

    JØRGENSEN, BB

    1995-01-01

    metabolism types, bacteria in the mostly anoxic sea floor play an important role in the major element cycles of the ocean. The communities of giant, filamentous sulfur bacteria that live in the deep-sea hydrothermal vents or along the Pacific coast of South America are presented here as examples....

  12. Biodiversity of Bacteria Isolated from Different Soils

    Directory of Open Access Journals (Sweden)

    Fatma YAMAN

    2017-01-01

    Full Text Available The aim of this study was to determine the biodiversity of PHB producing bacteria isolated from soils where fruit and vegetable are cultivated (onion, grape, olive, mulberry and plum in Aydın providence. Morphological, cultural, biochemical, and molecular methods were used for bacteria identification. These isolated bacteria were identified by 16S rRNA sequencing and using BLAST. The following bacteria Bacillus thuringiensis (6, Bacillus cereus (8, Bacillus anthrachis (1, Bacillus circulans (1, Bacillus weihenstephanensis (1, Pseudomonas putida (1, Azotobacter chroococcum (1, Brevibacterium frigoritolerans (1, Burkholderia sp. (1, Staphylococcus epidermidis (1, Streptomyces exfoliatus (1, Variovorax paradoxus (1 were found. The Maximum Likelihood method was used to produce a molecular phylogenetic analysis and a phylogenetic tree was constructed. These bacteria can produce polyhydroxybutyrate (PHB which is an organic polymer with commercial potential as a biodegradable thermoplastic. PHB can be used instead of petrol derivated non-degradable plastics. For this reason, PHB producing microorganisms are substantial in industry.

  13. Coryneform bacteria associated with canine otitis externa

    DEFF Research Database (Denmark)

    Aalbæk, Bent; Bemis, David A.; Schjærff, Mette

    2010-01-01

    This study aims to investigate the occurrence of coryneform bacteria in canine otitis externa. A combined case series and case-control study was carried out to improve the current knowledge on frequency and clinical significance of coryneform bacteria in samples from canine otitis externa. A total...... of 16 cases of otitis externa with involvement of coryneform bacteria were recorded at two referral veterinary hospitals in Denmark and the US, respectively. Coryneform bacteria were identified by partial 16S rRNA gene sequencing. Corynebacterium auriscanis was the most common coryneform species (10...... cases). Small colony variants of this species were also observed. Other coryneform isolates were identified as Corynebacterium amycolatum (3 cases), Corynebacterium freneyi (2 cases) and an Arcanobacterium-like species (1 case). The coryneform bacteria were in all cases isolated together with other...

  14. HYDROCARBON-DEGRADING BACTERIA AND SURFACTANT ACTIVITY

    Energy Technology Data Exchange (ETDEWEB)

    Brigmon, R; Topher Berry, T; Grazyna A. Plaza, G; jacek Wypych, j

    2006-08-15

    Fate of benzene ethylbenzene toluene xylenes (BTEX) compounds through biodegradation was investigated using two different bacteria, Ralstonia picketti (BP-20) and Alcaligenes piechaudii (CZOR L-1B). These bacteria were isolated from extremely polluted petroleum hydrocarbon contaminated soils. PCR and Fatty Acid Methyl Ester (FAME) were used to identify the isolates. Biodegradation was measured using each organism individually and in combination. Both bacteria were shown to degrade each of the BTEX compounds. Alcaligenes piechaudii biodegraded BTEXs more efficiently while mixed with BP-20 and individually. Biosurfactant production was observed by culture techniques. In addition 3-hydroxy fatty acids, important in biosurfactant production, was observed by FAME analysis. In the all experiments toluene and m+p- xylenes were better growth substrates for both bacteria than the other BTEX compounds. In addition, the test results indicate that the bacteria could contribute to bioremediation of aromatic hydrocarbons (BTEX) pollution increase biodegradation through the action by biosurfactants.

  15. [Unique properties of highly radioresistant bacteria].

    Science.gov (United States)

    Romanovskaia, V A; Rokitko, P V; Malashenko, Iu R

    2000-01-01

    In connection with the Chernobyl Nuclear Power Plant (ChNPP) accident and the negative ecological after-effects for biota in this zone the interest has arisen to radioresistant bacteria, as to the most dynamic model of the given ecosystem, and to mechanisms which provide resistance of bacteria to ionizing radiation. The analysis of published data has shown that the radioresistant bacteria are not interrelated taxonomically and phylogenetically. The extreme radioresistant bacteria are represented by the Deinococcus species, which form a group phylogenetically close to the line Thermus-Meiothermus. Other radioresistant bacteria are the representatives of the genera Rubrobacter, Methylobacterium, Kocuria, Bacillus and some archebacteria. Data on natural habitats, of radioresistant bacteria are not numerous. In a number of cases it is difficult to distinguish their natural habitats, as they were isolated from the samples which were previously exposed to X-ray or gamma-irradiation, or from the ecosystems with the naturally raised radioactivity. To understand the strategy of survival of radioresistant bacteria, we briefly reviewed the mechanism of action of various species of radiation on cells and macromolecules; physiological signs of the cell damage caused by radiation; mechanisms eliminating (repairing) these damages. More details on mechanisms of the DNA repair in D. radiodurans are described. The extreme resistance of D. radiodurans to the DNA damaging factors is defined by 1) repair mechanisms which fundamentally differ from those in other procaryotes; 2) ability to increase the efficiency of a standard set of the DNA repairing proteins. Literary and own data on the effect of radiation on survival of various groups of bacteria in natural ecosystems are summarized. The ecological consequences of the ChNPP accident for soil bacteria in this region were estimated. The reduction of the number of soil bacteria and recession of microbial diversity under the effect of

  16. Tape Cassette Bacteria Detection System

    Science.gov (United States)

    1973-01-01

    The design, fabrication, and testing of an automatic bacteria detection system with a zero-g capability and based on the filter-capsule approach is described. This system is intended for monitoring the sterility of regenerated water in a spacecraft. The principle of detection is based on measuring the increase in chemiluminescence produced by the action of bacterial porphyrins (i.e., catalase, cytochromes, etc.) on a luminol-hydrogen peroxide mixture. Since viable as well as nonviable organisms initiate this luminescence, viable organisms are detected by comparing the signal of an incubated water sample with an unincubated control. Higher signals for the former indicate the presence of viable organisms. System features include disposable sealed sterile capsules, each containing a filter membrane, for processing discrete water samples and a tape transport for moving these capsules through a processing sequence which involves sample concentration, nutrient addition, incubation, a 4 Molar Urea wash and reaction with luminol-hydrogen peroxide in front of a photomultiplier tube. Liquids are introduced by means of a syringe needle which pierces a rubber septum contained in the wall of the capsule. Detection thresholds obtained with this unit towards E. coli and S. marcescens assuming a 400 ml water sample are indicated.

  17. Antibiotic resistance in probiotic bacteria

    Directory of Open Access Journals (Sweden)

    Miguel eGueimonde

    2013-07-01

    Full Text Available Probiotics are live microorganisms which when administered in adequate amounts confer a health benefit on the host. The main probiotic bacteria are strains belonging to the genera Lactobacillus and Bifidobacterium, although other representatives, such as Bacillus or Escherichia coli strains, have also been used. Lactobacillus and Bifidobacterium are two common inhabitants of the human intestinal microbiota. Also, some species are used in food fermentation processes as starters, or as adjunct cultures in the food industry. With some exceptions, antibiotic resistance in these beneficial microbes does not constitute a safety concern in itself, when mutations or intrinsic resistance mechanisms are responsible for the resistance phenotype. In fact, some probiotic strains with intrinsic antibiotic resistance could be useful for restoring the gut microbiota after antibiotic treatment. However, specific antibiotic resistance determinants carried on mobile genetic elements, such as tetracycline resistance genes, are often detected in the typical probiotic genera, and constitute a reservoir of resistance for potential food or gut pathogens, thus representing a serious safety issue.

  18. Comparative cytotoxicity of periodontal bacteria

    International Nuclear Information System (INIS)

    Stevens, R.H.; Hammond, B.F.

    1988-01-01

    The direct cytotoxicity of sonic extracts (SE) from nine periodontal bacteria for human gingival fibroblasts (HGF) was compared. Equivalent dosages (in terms of protein concentration) of SE were used to challenge HGF cultures. The cytotoxic potential of each SE was assessed by its ability to (1) inhibit HGF proliferation, as measured by direct cell counts; (2) inhibit 3H-thymidine incorporation in HGF cultures; or (3) cause morphological alterations of the cells in challenged cultures. The highest concentration (500 micrograms SE protein/ml) of any of the SEs used to challenge the cells was found to be markedly inhibitory to the HGFs by all three of the criteria of cytotoxicity. At the lowest dosage tested (50 micrograms SE protein/ml); only SE from Actinobacillus actinomycetemcomitans, Bacteroides gingivalis, and Fusobacterium nucleatum caused a significant effect (greater than 90% inhibition or overt morphological abnormalities) in the HGFs as determined by any of the criteria employed. SE from Capnocytophaga sputigena, Eikenella corrodens, or Wolinella recta also inhibited cell proliferation and thymidine incorporation at this dosage; however, the degree of inhibition (5-50%) was consistently, clearly less than that of the first group of three organisms named above. The SE of the three other organisms tested (Actinomyces odontolyticus, Bacteroides intermedius, and Streptococcus sanguis) had little or no effect (0-10% inhibition) at this concentration. The data suggest that the outcome of the interaction between bacterial components and normal resident cells of the periodontium is, at least in part, a function of the bacterial species

  19. Comparative cytotoxicity of periodontal bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, R.H.; Hammond, B.F.

    1988-11-01

    The direct cytotoxicity of sonic extracts (SE) from nine periodontal bacteria for human gingival fibroblasts (HGF) was compared. Equivalent dosages (in terms of protein concentration) of SE were used to challenge HGF cultures. The cytotoxic potential of each SE was assessed by its ability to (1) inhibit HGF proliferation, as measured by direct cell counts; (2) inhibit 3H-thymidine incorporation in HGF cultures; or (3) cause morphological alterations of the cells in challenged cultures. The highest concentration (500 micrograms SE protein/ml) of any of the SEs used to challenge the cells was found to be markedly inhibitory to the HGFs by all three of the criteria of cytotoxicity. At the lowest dosage tested (50 micrograms SE protein/ml); only SE from Actinobacillus actinomycetemcomitans, Bacteroides gingivalis, and Fusobacterium nucleatum caused a significant effect (greater than 90% inhibition or overt morphological abnormalities) in the HGFs as determined by any of the criteria employed. SE from Capnocytophaga sputigena, Eikenella corrodens, or Wolinella recta also inhibited cell proliferation and thymidine incorporation at this dosage; however, the degree of inhibition (5-50%) was consistently, clearly less than that of the first group of three organisms named above. The SE of the three other organisms tested (Actinomyces odontolyticus, Bacteroides intermedius, and Streptococcus sanguis) had little or no effect (0-10% inhibition) at this concentration. The data suggest that the outcome of the interaction between bacterial components and normal resident cells of the periodontium is, at least in part, a function of the bacterial species.

  20. Potential role of bacteria packaging by protozoa in the persistence and transmission of pathogenic bacteria

    Directory of Open Access Journals (Sweden)

    Alix M Denoncourt

    2014-05-01

    Full Text Available Many pathogenic bacteria live in close association with protozoa. These unicellular eukaryotic microorganisms are ubiquitous in various environments. A number of protozoa such as amoebae and ciliates ingest pathogenic bacteria, package them usually in membrane structures, and then release them into the environment. Packaged bacteria are more resistant to various stresses and are more apt to survive than free bacteria. New evidence indicates that protozoa and not bacteria control the packaging process. It is possible that packaging is more common than suspected and may play a major role in the persistence and transmission of pathogenic bacteria. To confirm the role of packaging in the propagation of infections, it is vital that the molecular mechanisms governing the packaging of bacteria by protozoa be identified as well as elements related to the ecology of this process in order to determine whether packaging acts as a Trojan Horse.

  1. Counting bacteria on a microfluidic chip.

    Science.gov (United States)

    Song, Yongxin; Zhang, Hongpeng; Chon, Chan Hee; Chen, Shu; Pan, Xinxiang; Li, Dongqing

    2010-11-29

    This paper reports a lab-on-a-chip device that counts the number of bacteria flowing through a microchannel. The bacteria number counting is realized by a microfluidic differential Resistive Pulse Sensor (RPS). By using a single microfluidic channel with two detecting arm channels placed at the two ends of the sensing section, the microfluidic differential RPS can achieve a high signal-to-noise ratio. This method is applied to detect and count bacteria in aqueous solution. The detected RPS signals amplitude for Pseudomonas aeruginosa ranges from 0.05 V to 0.17 V and the signal-to-noise ratio is 5-17. The number rate of the bacteria flowing through the sensing gate per minute is a linear function of the sample concentration. Using this experimentally obtained correlation curve, the concentration of bacteria in the sample solution can be evaluated within several minutes by measuring the number rate of the bacteria flowing through the sensing gate of this microfluidic differential RPS chip. The method described in this paper is simple and automatic, and have wide applications in determining the bacteria and cell concentrations for microbiological and other biological applications. Copyright © 2010 Elsevier B.V. All rights reserved.

  2. Fermentative Bacteria Influence the Competition between Denitrifiers and DNRA Bacteria

    Directory of Open Access Journals (Sweden)

    Eveline M. van den Berg

    2017-09-01

    results of this study clearly show that not only the ratio of available substrates, but also the nature of the electron donor influences the outcome of competition between DNRA and denitrification. Apparently, fermentative bacteria are competitive for the electron donor and thereby alter the ratio of available substrates for nitrate reduction.

  3. Folate Production by Probiotic Bacteria

    Directory of Open Access Journals (Sweden)

    Stefano Raimondi

    2011-01-01

    Full Text Available Probiotic bacteria, mostly belonging to the genera Lactobacillus and Bifidobacterium, confer a number of health benefits to the host, including vitamin production. With the aim to produce folate-enriched fermented products and/or develop probiotic supplements that accomplish folate biosynthesis in vivo within the colon, bifidobacteria and lactobacilli have been extensively studied for their capability to produce this vitamin. On the basis of physiological studies and genome analysis, wild-type lactobacilli cannot synthesize folate, generally require it for growth, and provide a negative contribution to folate levels in fermented dairy products. Lactobacillus plantarum constitutes an exception among lactobacilli, since it is capable of folate production in presence of para-aminobenzoic acid (pABA and deserves to be used in animal trials to validate its ability to produce the vitamin in vivo. On the other hand, several folate-producing strains have been selected within the genus Bifidobacterium, with a great variability in the extent of vitamin released in the medium. Most of them belong to the species B. adolescentis and B. pseudocatenulatum, but few folate producing strains are found in the other species as well. Rats fed a probiotic formulation of folate-producing bifidobacteria exhibited increased plasma folate level, confirming that the vitamin is produced in vivo and absorbed. In a human trial, the same supplement raised folate concentration in feces. The use of folate-producing probiotic strains can be regarded as a new perspective in the specific use of probiotics. They could more efficiently confer protection against inflammation and cancer, both exerting the beneficial effects of probiotics and preventing the folate deficiency that is associated with premalignant changes in the colonic epithelia.

  4. Bacteria classification using Cyranose 320 electronic nose

    Directory of Open Access Journals (Sweden)

    Gardner Julian W

    2002-10-01

    Full Text Available Abstract Background An electronic nose (e-nose, the Cyrano Sciences' Cyranose 320, comprising an array of thirty-two polymer carbon black composite sensors has been used to identify six species of bacteria responsible for eye infections when present at a range of concentrations in saline solutions. Readings were taken from the headspace of the samples by manually introducing the portable e-nose system into a sterile glass containing a fixed volume of bacteria in suspension. Gathered data were a very complex mixture of different chemical compounds. Method Linear Principal Component Analysis (PCA method was able to classify four classes of bacteria out of six classes though in reality other two classes were not better evident from PCA analysis and we got 74% classification accuracy from PCA. An innovative data clustering approach was investigated for these bacteria data by combining the 3-dimensional scatter plot, Fuzzy C Means (FCM and Self Organizing Map (SOM network. Using these three data clustering algorithms simultaneously better 'classification' of six eye bacteria classes were represented. Then three supervised classifiers, namely Multi Layer Perceptron (MLP, Probabilistic Neural network (PNN and Radial basis function network (RBF, were used to classify the six bacteria classes. Results A [6 × 1] SOM network gave 96% accuracy for bacteria classification which was best accuracy. A comparative evaluation of the classifiers was conducted for this application. The best results suggest that we are able to predict six classes of bacteria with up to 98% accuracy with the application of the RBF network. Conclusion This type of bacteria data analysis and feature extraction is very difficult. But we can conclude that this combined use of three nonlinear methods can solve the feature extraction problem with very complex data and enhance the performance of Cyranose 320.

  5. Mortality of fecal bacteria in seawater

    International Nuclear Information System (INIS)

    Garcia-Lara, J.; Menon, P.; Servais, P.; Billen, G.

    1991-01-01

    The authors propose a method for determining the mortality rate for allochthonous bacteria released in aquatic environments without interference due to the loss of culturability in specific culture media. This method consists of following the disappearance of radioactivity from the trichloracetic acid-insoluble fraction in water samples to which [ 3 H]thymidine-prelabeled allochthonous bacteria have been added. In coastal seawater, they found that the actual rate of disappearance of fecal bacteria was 1 order of magnitude lower than the rate of loss of culturability on specific media. Minor adaptation of the procedure may facilitate assessment of the effect of protozoan grazing and bacteriophage lysis on the overall bacterial mortality rate

  6. Anaerobic bacteria, the colon and colitis.

    Science.gov (United States)

    Roediger, W E

    1980-02-01

    Anaerobic bacteria constitute more than 90% of the bacteria in the colon. An anaerobic environment is needed to maintain their growth and the production of short-chain fatty acids by these bacteria from carbohydrates. Short-chain fatty acids are rapidly absorbed and essential for metabolic as well as functional welfare of the colonic mucosa. The importance of these acids in water absorption and in the patogenesis of colitis is discussed in relation to the concept of "energy deficiency diseases" of the colonic mucosa.

  7. Second messenger - Sensing riboswitches in bacteria.

    Science.gov (United States)

    Ramesh, Arati

    2015-12-01

    Signal sensing in bacteria has traditionally been attributed to protein-based factors. It is however becoming increasingly clear that bacteria also exploit RNAs to serve this role. This review discusses how key developmental processes in bacteria, such as community formation, choice of a sessile versus motile lifestyle, or vegetative growth versus dormant spore formation may be governed by signal sensing RNAs. The signaling molecules that affect these processes, the RNAs that sense these molecules and the underlying molecular basis for specific signal-response are discussed here. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Bacteria Culture Test: MedlinePlus Lab Test Information

    Science.gov (United States)

    ... this page: https://medlineplus.gov/labtests/bacteriaculturetest.html Bacteria Culture Test To use the sharing features on this page, please enable JavaScript. What is a Bacteria Culture Test? Bacteria are a large group of ...

  9. Comparative genomics of the lactic acid bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Makarova, K.; Slesarev, A.; Wolf, Y.; Sorokin, A.; Mirkin, B.; Koonin, E.; Pavlov, A.; Pavlova, N.; Karamychev, V.; Polouchine, N.; Shakhova, V.; Grigoriev, I.; Lou, Y.; Rokhsar, D.; Lucas, S.; Huang, K.; Goodstein, D. M.; Hawkins, T.; Plengvidhya, V.; Welker, D.; Hughes, J.; Goh, Y.; Benson, A.; Baldwin, K.; Lee, J. -H.; Diaz-Muniz, I.; Dosti, B.; Smeianov, V; Wechter, W.; Barabote, R.; Lorca, G.; Altermann, E.; Barrangou, R.; Ganesan, B.; Xie, Y.; Rawsthorne, H.; Tamir, D.; Parker, C.; Breidt, F.; Broadbent, J.; Hutkins, R.; O' Sullivan, D.; Steele, J.; Unlu, G.; Saier, M.; Klaenhammer, T.; Richardson, P.; Kozyavkin, S.; Weimer, B.; Mills, D.

    2006-06-01

    Lactic acid-producing bacteria are associated with various plant and animal niches and play a key role in the production of fermented foods and beverages. We report nine genome sequences representing the phylogenetic and functional diversity of these bacteria. The small genomes of lactic acid bacteria encode a broad repertoire of transporters for efficient carbon and nitrogen acquisition from the nutritionally rich environments they inhabit and reflect a limited range of biosynthetic capabilities that indicate both prototrophic and auxotrophic strains. Phylogenetic analyses, comparison of gene content across the group, and reconstruction of ancestral gene sets indicate a combination of extensive gene loss and key gene acquisitions via horizontal gene transfer during the coevolution of lactic acid bacteria with their habitats.

  10. Lactic acid bacteria: microbiological and functional aspects

    National Research Council Canada - National Science Library

    Lahtinen, Sampo

    2012-01-01

    "Updated with the substantial progress made in lactic acid and bacteria research since the third edition, this fourth volume discusses improved insights in genetics and new molecular biological techniques...

  11. Ecology: Electrical Cable Bacteria Save Marine Life

    DEFF Research Database (Denmark)

    Nielsen, Lars Peter

    2016-01-01

    Animals at the bottom of the sea survive oxygen depletion surprisingly often, and a new study identifies cable bacteria in the sediment as the saviors. The bacterial electrical activity creates an iron 'carpet', trapping toxic hydrogen sulfide....

  12. Flow cytometry, fluorescent probes, and flashing bacteria

    NARCIS (Netherlands)

    Bunthof, C.J.

    2002-01-01


    Key words: fluorescent probes, flow cytometry, CSLM, viability, survival, microbial physiology, lactic acid bacteria, Lactococcus lactis , Lactobacillus plantarum , cheese, milk,

  13. Effect of leukocyte hydrolases on bacteria

    International Nuclear Information System (INIS)

    Cohen, D.; Michel, J.; Ferne, M.; Bergner-Rabinowitz, S.; Ginsburg, I.

    1979-01-01

    Leukocyte extracts, trypsin, and lysozyme are all capable of releasing the bulk of the LPS from S. typhi, S. typhimurium, and E. coli. Bacteria which have been killed by heat, ultraviolet irradiation, or by a variety of metabolic inhibitors and antibiotics which affect protein, DNA, RNA, and cell wall synthesis no longer yield soluble LPS following treatment with the releasing agents. On the other hand, bacteria which are resistant to certain of the antibiotics yield nearly the full amount of soluble LPS following treatment, suggesting that certain heatabile endogenous metabolic pathways collaborate with the releasing agents in the release of LPS from the bacteria. It is suggested that some of the beneficial effects of antibiotics on infections with gram-negative bacteria may be the prevention of massive release of endotoxin by leukocyte enzymes in inflammatory sites

  14. Distribution of phytopathogenic bacteria in infested seeds

    Science.gov (United States)

    Populations of phytopathogenic bacteria representing five host-pathogen combinations were assessed to determine if there was a mathematical relationship common across seedborne bacterial diseases. Bacterial populations were estimated from naturally-infested seeds of cowpea (Vigna unguiculata), peppe...

  15. Bacteria-mediated bisphenol A degradation.

    Science.gov (United States)

    Zhang, Weiwei; Yin, Kun; Chen, Lingxin

    2013-07-01

    Bisphenol A (BPA) is an important monomer in the manufacture of polycarbonate plastics, food cans, and other daily used chemicals. Daily and worldwide usage of BPA and BPA-contained products led to its ubiquitous distribution in water, sediment/soil, and atmosphere. Moreover, BPA has been identified as an environmental endocrine disruptor for its estrogenic and genotoxic activity. Thus, BPA contamination in the environment is an increasingly worldwide concern, and methods to efficiently remove BPA from the environment are urgently recommended. Although many factors affect the fate of BPA in the environment, BPA degradation is mainly depended on the metabolism of bacteria. Many BPA-degrading bacteria have been identified from water, sediment/soil, and wastewater treatment plants. Metabolic pathways of BPA degradation in specific bacterial strains were proposed, based on the metabolic intermediates detected during the degradation process. In this review, the BPA-degrading bacteria were summarized, and the (proposed) BPA degradation pathway mediated by bacteria were referred.

  16. Abundance, viability and culturability of Antarctic bacteria

    Digital Repository Service at National Institute of Oceanography (India)

    LokaBharathi, P.A.; DeSouza, M.J.B.D.; Nair, S.; Chandramohan, D.

    The viability of total number of bacteria decide the mineralisation rate in any ecosystem and ultimately the fertility of the region. This study aims at establishing the extent of viability in the standing stock of the Antarctic bacterial population...

  17. Systemic resistance induced by rhizosphere bacteria

    NARCIS (Netherlands)

    Loon, L.C. van; Bakker, P.A.H.M.; Pieterse, C.M.J.

    1998-01-01

    Nonpathogenic rhizobacteria can induce a systemic resistance in plants that is phenotypically similar to pathogen-induced systemic acquired resistance (SAR). Rhizobacteria-mediated induced systemic resistance (ISR) has been demonstrated against fungi, bacteria, and viruses in Arabidopsis, bean,

  18. Discovering lactic acid bacteria by genomics

    NARCIS (Netherlands)

    Klaenhammer, T; Altermann, E; Arigoni, F; Bolotin, A; Breidt, F; Broadbent, J; Cano, R; Chaillou, S; Deutscher, J; Gasson, M; van de Guchte, M; Guzzo, J; Hartke, A; Hawkins, T; Hols, P; Hutkins, R; Kleerebezem, M; Kok, J; Kuipers, O; Maguin, E; McKay, L; Mills, D; Nauta, A; Overbeek, R; Pel, H; Pridmore, D; Saier, M; van Sinderen, D; Sorokin, A; Steele, J; O'Sullivan, D; de Vos, W; Weimer, B; Zagorec, M; Siezen, R

    This review summarizes a collection of lactic acid bacteria that are now undergoing genomic sequencing and analysis. Summaries are presented on twenty different species, with each overview discussing the organisms fundamental and practical significance, environmental habitat, and its role in

  19. Do bacteria, not fish, produce 'fish kairomone'?

    NARCIS (Netherlands)

    Ringelberg, J.; Van Gool, E.

    1998-01-01

    Fish-associated chemicals enhance phototactic downward swimming in Daphnia. If perch were treated with the antibiotic ampicillin, this enhancement was significantly decreased. Therefore, not fish, but bacteria associated with fish, seem to produce this kairomone. [KEYWORDS: Diel vertical migration;

  20. Rapid methods for detection of bacteria

    DEFF Research Database (Denmark)

    Corfitzen, Charlotte B.; Andersen, B.Ø.; Miller, M.

    2006-01-01

    Traditional methods for detection of bacteria in drinking water e.g. Heterotrophic Plate Counts (HPC) or Most Probable Number (MNP) take 48-72 hours to give the result. New rapid methods for detection of bacteria are needed to protect the consumers against contaminations. Two rapid methods: Measu......: Measurements of Adosine Triphosphate and BactiQuantTM have shown promising results as new monitoring tools, which gives the result within minutes/hours....

  1. Potentials of Exopolysaccharides from Lactic Acid Bacteria

    OpenAIRE

    Patel, Seema; Majumder, Avishek; Goyal, Arun

    2011-01-01

    Recent research in the area of importance of microbes has revealed the immense industrial potential of exopolysaccharides and their derivative oligosaccharides from lactic acid bacteria. However, due to lack of adequate technological knowledge, the exopolysaccharides have remained largely under exploited. In the present review, the enormous potentials of different types of exopolysaccharides from lactic acid bacteria are described. This also summarizes the recent advances in the applications ...

  2. Systemic resistance induced by rhizosphere bacteria

    OpenAIRE

    Loon, L.C. van; Bakker, P.A.H.M.; Pieterse, C.M.J.

    1998-01-01

    Nonpathogenic rhizobacteria can induce a systemic resistance in plants that is phenotypically similar to pathogen-induced systemic acquired resistance (SAR). Rhizobacteria-mediated induced systemic resistance (ISR) has been demonstrated against fungi, bacteria, and viruses in Arabidopsis, bean, carnation, cucumber, radish, tobacco, and tomato under conditions in which the inducing bacteria and the challenging pathogen remained spatially separated. Bacterial strains differ in their ability to ...

  3. ORAL BACTERIA AND SYSTEMS DISEASES: A REVIEW

    OpenAIRE

    Moromi Nakata, Hilda

    2014-01-01

    In order to show a global vision of oral bacteria in systemic diseases, it is important to analyze the presence and consequences of these microorganisms in relation with: bacteremia, endocarditis, cardiovascular disease, cerebrovascular disease, bacterial pneumonia, neonatal weight, nefritis, arthritis, dermatitis and diabetes mellitus, reaching conclusions for each one of them. Con el objeto de presentar una visión general de la bacterias orales en los procesos sistémicos, se analiza la p...

  4. Molecular genetic studies on obligate anaerobic bacteria

    International Nuclear Information System (INIS)

    Woods, D.R.

    1982-01-01

    Molecular genetic studies on obligate anaerobic bacteria have lagged behind similar studies in aerobes. However, the current interest in biotechnology, the involvement of anaerobes in disease and the emergence of antibioticresistant strains have focused attention on the genetics of anaerobes. This article reviews molecular genetic studies in Bacteroides spp., Clostridium spp. and methanogens. Certain genetic systems in some anaerobes differ from those in aerobes and illustrate the genetic diversity among bacteria

  5. [Teichoic acids from lactic acid bacteria].

    Science.gov (United States)

    Livins'ka, O P; Harmasheva, I L; Kovalenko, N K

    2012-01-01

    The current view of the structural diversity of teichoic acids and their involvement in the biological activity of lactobacilli has been reviewed. The mechanisms of effects of probiotic lactic acid bacteria, in particular adhesive and immunostimulating functions have been described. The prospects of the use of structure data of teichoic acid in the assessment of intraspecific diversity of lactic acid bacteria have been also reflected.

  6. Competition for hydrogen by human faecal bacteria: evidence for the predominance of methane producing bacteria.

    OpenAIRE

    Strocchi, A; Furne, J K; Ellis, C J; Levitt, M D

    1991-01-01

    Studies of sludge have shown that some species of sulphate reducing bacteria outcompete methane producing bacteria for the common substrate H2. A similar competition may exist in human faeces where the methane (CH4) producing status of an individual depends on the faecal concentration of sulphate reducing bacteria. To determine if non-methanogenic faeces outcompete CH4 producing faeces for H2, aliquots of each type of faeces were incubated alone or mixed together, with or without addition of ...

  7. Caracterización molecular de bacterias patógenas de las vías respiratorias de pacientes peruanos con fibrosis quística

    Directory of Open Access Journals (Sweden)

    Ruth Aquino

    Full Text Available RESUMEN Objetivos. Caracterizar a nivel molecular las bacterias patógenas de las vías respiratorias de pacientes peruanos con fibrosis quística (FQ. Materiales y métodos. Se caracterizaron las comunidades bacterianas cultivables a partir de muestras de esputo de pacientes pediátricos y adultos con FQ registrados en el Hospital Nacional Edgardo Rebagliati Martins y el Instituto Nacional de Salud del Niño (INSN. Para el cultivo bacteriano se utilizaron técnicas microbiológicas estándares, y para la caracterización molecular la secuenciación del gen ARNr 16S y espectrometría de masas de tipo desorción/ionización con láser asistido por matriz con tiempo de vuelo (MALDI TOF y MALDI TOF/TOF. Resultados. Por secuenciación del ARNr 16S se identificaron 127 cepas, encontrando las bacterias patógenas Pseudomonas aeruginosa (31,5%, Staphylococcus aureus (12,6%, Pseudomonas spp. (11,8%, Klebsiella oxytoca (3,1%, otras especies mostraron baja prevalencia. El análisis por MALDI TOF permitió obtener una serie de espectros representativos de cada especie aislada, mientras que el análisis por MALDI TOF/TOF reveló péptidos y proteínas de las especies más comunes con informaciones complementarias que revelarían datos sobre su patogenicidad o sensibilidad a antibióticos. Conclusiones. Los principales microorganismos patógenos encontrados en las vías respiratorias son similares a los reportados en otros países. Estos son los primeros hallazgos en Perú que muestran la caracterización bacteriana por secuenciación del ARNr 16S, por MALDI TOF y MALDI TOF TOF. Los hallazgos permiten la identificación bacteriana de microorganismos nativos relacionados con la FQ basada en el análisis de su proteoma.

  8. Evaluación del potencial probiótico de bacterias ácido lácticas para reducir el colesterol in vitro

    Directory of Open Access Journals (Sweden)

    Clementina Cueto

    2012-01-01

    Full Text Available El co nsumo diario de alimentos probióticos reduce los niveles de colesterol sérico en un 3%, valor significativo para la prevención de la hipercolesterolemia, factor de riesgo de enfermedad cardiovascular y causal de mortalidad. Algunas especies del género Lact obacillus , utilizadas en la industria alimentaria como probiótico, reducen el colesterol sérico por dos mecanismos, la adsorción de colesterol y producción de la enzima hidrolasa de sales biliares. El objetivo del estudio fue evaluar el potencial probiótic o de un grupo de bacterias lácticas aisladas de suero costeño. Se aislaron 53 cepas a partir de nueve muestras de suero costeño; el potencial probiótico de las bacterias se evaluó por tolerancia a pH 2.0, 0.3% de sales biliares y sensibilidad a vancomicina y cefoxitin. Se seleccionaron cinco microorganismos y se identificaron molecularmente, como Lactobacillus fermentum . La capacidad de adsorber el colesterol medida por el método de Kimoto, presentó disminución de 53.06 ± 2.69 μg.mL - 1 para la cepa K73 y 7. 23 ± 2.69 μg.mL - 1 para la cepa K75. Esas mismas cepas mostraron la mayor actividad total y específica de la enzima. Los resultados evidenciaron que no existe relación entre la producción de la enzima y la adsorción del colesterol. La cepa con mayor potenci al probiótico fue K73. La propiedad hipocolesterolémica de Lactobacillus fermentum , podría ser el inicio de la búsqueda de matrices alimentarias que permitan disminuir los niveles del colesterol sérico y adicionen valor agregado al producto.

  9. Antioxidant activity of Sphaerococcus coronopifolius associated bacteria

    Directory of Open Access Journals (Sweden)

    Nádia Fino

    2014-06-01

    Full Text Available Associated bacteria living on macroalgae surfaces are an interesting source of new secondary metabolites with biological activities. The aim of this study was the isolation and identification of epiphytic bacteria from the marine algae Sphaerococcus coronopifolius and the evaluation of the antioxidant activity of the bacteria extracts. The identification of epiphytic bacteria was determined by 16S rRNA gene sequencing. Bacteria extracts were obtained with methanol and dichloromethane (1:1 extraction. Antioxidant activity was evaluated by quantification of total phenolic content (TPC, 2,2-diphenyl-1-picrylhydrazyl (DPPH radical scavenging activity and oxygen radical absorbent capacity (ORAC. The extracts with higher antioxidant activity were tested on MCF-7 and HepG-2 cell lines in oxidative stress conditions induced by H2O2 at 0.2 mM and 0.5 mM, respectively. In total were isolated 21 Sphaerococcus coronopifolius associated bacteria and identified as Vibrio sp. (28.57%, Shewanella sp. (23.81%, Pseudoalteromonas sp. (19.05%, Bacillus sp. (9.52% and Halomonas sp. (9.52%. Two (9.52% of them presented less than 90% Basic Local Alignment Search Tool (BLAST match. The epiphytic bacteria with the most antioxidant potential evaluated by ORAC and DPPH methods were Sp2, Sp12, Sp23, Sp25 and Sp27. The strain Sp4 show high antioxidant activity in all antioxidant methods (ORAC, DPPH and TPC. In oxidative stress conditions on MCF-7 cell line, the extracts of bacteria (1mg.ml-1: 24hours Sp4 (16.15%, Sp25 (17.95% and Sp27 (10.65% prevented the cell death induced by H2O2. In the HepG-2 cell line was the extracts of Sp2 (9.01%, Sp4 (11.21%, Sp12 (7.20% and Sp23 (8.81% bacteria that high prevented the oxidative stress condition induced by H2O2. In conclusion, the Sphaerococcus coronopifolius associated bacteria can be an interesting and excellent source of marine natural compounds with antioxidant activity.

  10. Magnetosome chain superstructure in uncultured magnetotactic bacteria

    International Nuclear Information System (INIS)

    Abraçado, Leida G; Farina, Marcos; Abreu, Fernanda; Keim, Carolina N; Lins, Ulysses; Campos, Andrea P C

    2010-01-01

    Magnetotactic bacteria produce magnetosomes, which are magnetic particles enveloped by biological membranes, in a highly controlled mineralization process. Magnetosomes are used to navigate in magnetic fields by a phenomenon called magnetotaxis. Two levels of organization and control are recognized in magnetosomes. First, magnetotactic bacteria create a spatially distinct environment within vesicles defined by their membranes. In the vesicles, the bacteria control the size, composition and purity of the mineral content of the magnetic particles. Unique crystal morphologies are produced in magnetosomes as a consequence of this bacterial control. Second, magnetotactic bacteria organize the magnetosomes in chains within the cell body. It has been shown in a particular case that the chains are positioned within the cell body in specific locations defined by filamentous cytoskeleton elements. Here, we describe an additional level of organization of the magnetosome chains in uncultured magnetotactic cocci found in marine and freshwater sediments. Electron microscopy analysis of the magnetosome chains using a goniometer showed that the magnetic crystals in both types of bacteria are not oriented at random along the crystal chain. Instead, the magnetosomes have specific orientations relative to the other magnetosomes in the chain. Each crystal is rotated either 60°, 180° or 300° relative to their neighbors along the chain axis, causing the overlapping of the (1 1 1) and (1-bar 1-bar 1-bar) capping faces of neighboring crystals. We suggest that genetic determinants that are not present or active in bacteria with magnetosomes randomly rotated within a chain must be present in bacteria that organize magnetosomes so precisely. This particular organization may also be used as an indicative biosignature of magnetosomes in the study of magnetofossils in the cases where this symmetry is observed

  11. [Spectrum and susceptibility of preoperative conjunctival bacteria].

    Science.gov (United States)

    Fernández-Rubio, M E; Cuesta-Rodríguez, T; Urcelay-Segura, J L; Cortés-Valdés, C

    2013-12-01

    To describe the conjunctival bacterial spectrum of our patients undergoing intraocular surgery and their antibiotic sensitivity during the study period. A retrospective study of preoperative conjunctival culture of patients consecutively scheduled for intraocular surgery from 21 February 2011 to 1 April 2013. Specimens were directly seeded onto blood-agar and MacConkey-agar (aerobiosis incubation, 2 days), and on chocolate-agar (6% CO2 incubation, 7 days). The identified bacteria were divided into 3 groups according to their origin; the bacteria susceptibility tests were performed on those more pathogenic and on some of the less pathogenic when more than 5 colonies were isolated. The sensitivity of the exigent growing bacteria was obtained with disk diffusion technique, and for of the non-exigent bacteria by determining their minimum inhibitory concentration. The Epidat 3.1 program was used for statistical calculations. A total of 13,203 bacteria were identified in 6,051 cultures, with 88.7% being typical colonizers of conjunctiva (group 1), 8.8% typical of airways (group 2), and the remaining 2.5% of undetermined origin (group 3). 530 cultures (8.8%) were sterile. The sensitivity of group 1 was: 99% vancomycin, 95% rifampicin, 87% chloramphenicol, 76% tetracycline. Levels of co-trimoxazole, aminoglycosides, quinolones, β-lactams and macrolides decreased since 2007. The group 2 was very sensitive to chloramphenicol, cefuroxime, rifampicin, ciprofloxacin and amoxicillin/clavulanate. In group 3, to levofloxacin 93%, ciprofloxacin 89%, tobramycin 76%, but ceftazidime 53% and cefuroxime 29% decreased. None of the tested antibiotics could eradicate all possible conjunctival bacteria. Bacteria living permanently on the conjunctiva (group 1) have achieved higher resistance than the eventual colonizers. Copyright © 2013 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.

  12. Biodegradation of shea nut cake by indigenous soil bacteria ...

    African Journals Online (AJOL)

    This is to isolate bacteria with high shea nut cake degrading ability and consequently select the potential application of these bacteria in bioremediation. The bacteria were grown in mineral salt medium supplemented with 2% shea nut cake as sole source of carbon. More Gram negative bacteria were involved in shea nut ...

  13. Multi-hop conjugation based bacteria nanonetworks.

    Science.gov (United States)

    Balasubramaniam, Sasitharan; Lio', Pietro

    2013-03-01

    Molecular communication is a new paradigm for nanomachines to exchange information, by utilizing biological mechanism and/or components to transfer information (e.g., molecular diffusion, neuronal networks, molecular motors). One possible approach for molecular communication is through the use of bacteria, which can act as carriers for DNA-based information, i.e., plasmids. This paper analyzes multi-hop molecular nanonetworks that utilize bacteria as a carrier. The proposed approach combines different properties of bacteria to enable multi-hop transmission, such as conjugation and chemotaxis-based motility. Various analyses have been performed, including the correlation between the success rate of plasmid delivery to the destination node, and the role of conjugation in enabling this; as well as analyses on the impact of large topology shapes (e.g., Grid, Random, and Scale-free) on the success rate of plasmid delivery for multiple source-destination nanonetworks. A further solution proposed in this paper is the application of antibiotics to act as filters on illegitimate messages that could be delivered by the bacteria. Our evaluation, which has been conducted through a series of simulations, has shown that numerous bacteria properties fit to properties required for communication networking (e.g., packet filtering, routing, addressing).

  14. Overlapping riboflavin supply pathways in bacteria.

    Science.gov (United States)

    García-Angulo, Víctor Antonio

    2017-03-01

    Riboflavin derivatives are essential cofactors for a myriad of flavoproteins. In bacteria, flavins importance extends beyond their role as intracellular protein cofactors, as secreted flavins are a key metabolite in a variety of physiological processes. Bacteria obtain riboflavin through the endogenous riboflavin biosynthetic pathway (RBP) or by the use of importer proteins. Bacteria frequently encode multiple paralogs of the RBP enzymes and as for other micronutrient supply pathways, biosynthesis and uptake functions largely coexist. It is proposed that bacteria shut down biosynthesis and would rather uptake riboflavin when the vitamin is environmentally available. Recently, the overlap of riboflavin provisioning elements has gained attention and the functions of duplicated paralogs of RBP enzymes started to be addressed. Results point towards the existence of a modular structure in the bacterial riboflavin supply pathways. Such structure uses subsets of RBP genes to supply riboflavin for specific functions. Given the importance of riboflavin in intra and extracellular bacterial physiology, this complex array of riboflavin provision pathways may have developed to contend with the various riboflavin requirements. In riboflavin-prototrophic bacteria, riboflavin transporters could represent a module for riboflavin provision for particular, yet unidentified processes, rather than substituting for the RBP as usually assumed.

  15. Molecular analysis of deep subsurface bacteria

    International Nuclear Information System (INIS)

    Jimenez Baez, L.E.

    1989-09-01

    Deep sediments samples from site C10a, in Appleton, and sites, P24, P28, and P29, at the Savannah River Site (SRS), near Aiken, South Carolina were studied to determine their microbial community composition, DNA homology and mol %G+C. Different geological formations with great variability in hydrogeological parameters were found across the depth profile. Phenotypic identification of deep subsurface bacteria underestimated the bacterial diversity at the three SRS sites, since bacteria with the same phenotype have different DNA composition and less than 70% DNA homology. Total DNA hybridization and mol %G+C analysis of deep sediment bacterial isolates suggested that each formation is comprised of different microbial communities. Depositional environment was more important than site and geological formation on the DNA relatedness between deep subsurface bacteria, since more 70% of bacteria with 20% or more of DNA homology came from the same depositional environments. Based on phenotypic and genotypic tests Pseudomonas spp. and Acinetobacter spp.-like bacteria were identified in 85 million years old sediments. This suggests that these microbial communities might have been adapted during a long period of time to the environmental conditions of the deep subsurface

  16. Modulation of immune homeostasis by commensal bacteria

    Science.gov (United States)

    Ivanov, Ivaylo I.; Littman, Dan R.

    2011-01-01

    Intestinal bacteria form a resident community that has co-evolved with the mammalian host. In addition to playing important roles in digestion and harvesting energy, commensal bacteria are crucial for the proper functioning of mucosal immune defenses. Most of these functions have been attributed to the presence of large numbers of “innocuous” resident bacteria that dilute or occupy niches for intestinal pathogens or induce innate immune responses that sequester bacteria in the lumen, thus quenching excessive activation of the mucosal immune system. However it has recently become obvious that commensal bacteria are not simply beneficial bystanders, but are important modulators of intestinal immune homeostasis and that the composition of the microbiota is a major factor in pre-determining the type and robustness of mucosal immune responses. Here we review specific examples of individual members of the microbiota that modify innate and adaptive immune responses, and we focus on potential mechanisms by which such species-specific signals are generated and transmitted to the host immune system. PMID:21215684

  17. Bacteria and plutonium in marine environments

    International Nuclear Information System (INIS)

    Carey, A.E.; Bowen, V.T.

    1978-01-01

    Microbes are important in geochemical cycling of many elements. Recent reports emphasize biogenous particulates and bacterial exometabolites as controlling oceanic distribution of plutonium. Bacteria perform oxidation/reduction reactions on metals such as mercury, nickel, lead, copper, and cadmium. Redox transformations or uptake of Pu by marine bacteria may well proceed by similar mechanisms. Profiles of water samples and sediment cores were obtained along the continental shelf off Nova Scotia and in the Gulf of St. Lawrence. Profiles of water samples, and sediment cores were obtained. Epifluorescent microscopy was used to view bacteria (from water or sediment) after concentration on membrane filters and staining with acridine orange. Radiochemical analyses measured Pu in sediments and water samples. Studies of 237 Pu uptake used a strain of Leucothrix mucor isolated from a macroalga. Enumeration shows bacteria to range 10 4 to 10 5 cells/ml in seawater or 10 7 to 10 8 cells/gram of sediment. These numbers are related to the levels and distrbution of Pu in the samples. In cultures of L. mucor amended with Pu atom concentrations approximating those present in open ocean environments, bacterial cells concentrated 237 Pu slower and to lower levels than did clay minerals, glass beads, or phytoplankton. These data further clarify the role of marine bacteria in Pu biogeochemistry

  18. COMPETITION BETWEEN ANOXYGENIC PHOTOTROPHIC BACTERIA AND COLORLESS SULFUR BACTERIA IN A MICROBIAL MAT

    NARCIS (Netherlands)

    VISSCHER, PT; VANDENENDE, FP; SCHAUB, BEM; VANGEMERDEN, H

    The populations of chemolithoautotrophic (colorless) sulfur bacteria and anoxygenic phototrophic bacteria were enumerated in a marine microbial mat. The highest population densities were found in the 0-5 mm layer of the mat: 2.0 X 10(9) cells CM-3 sediment, and 4.0 X 10(7) cells cm-3 sediment for

  19. Method of Detecting Coliform Bacteria and Escherichia Coli Bacteria from Reflected Light

    Science.gov (United States)

    Vincent, Robert (Inventor)

    2013-01-01

    The present invention relates to a method of detecting coliform bacteria in water from reflected light and a method of detecting Eschericha Coli bacteria in water from reflected light, and also includes devices for the measurement, calculation and transmission of data relating to that method.

  20. Bacteria interfere with A. actinomycetemcomitans colonization.

    Science.gov (United States)

    Teughels, W; Kinder Haake, S; Sliepen, I; Pauwels, M; Van Eldere, J; Cassiman, J-J; Quirynen, M

    2007-07-01

    It is known that beneficial bacteria can suppress the emergence of pathogenic bacteria, particularly in the gastrointestinal tract. This study examined the potential for a similar suppression of Aggregatibacter (formerly Actinobacillus) actinomycetemcomitans colonization of epithelial cells, due to its potential relevance in periodontal diseases. Seven presumed beneficial bacteria were examined for their ability to interfere, exclude, or displace A. actinomycetemcomitans from epithelial cells in vitro. Streptococcus sanguinis, Streptococcus mitis, and Streptococcus salivarius showed prominent inhibitory effects on either A. actinomycetemcomitans recovery or colonization. These results confirmed the hypothesis that bacterial interactions interfere with A. actinomycetemcomitans colonization of epithelial cells in vitro, and demonstrated the potential beneficial effects of S. mitis, S. salivarius, and S. sanguinis.

  1. Lethal photosensitization of biofilm-grown bacteria

    Science.gov (United States)

    Wilson, Michael

    1997-12-01

    Antibacterial agents are increasingly being used for the prophylaxis and treatment of oral diseases. As these agents can be rendered ineffective by resistance development in the target organisms there is a need to develop alternative antimicrobial approaches. Light-activated antimicrobial agents release singlet oxygen and free radicals which can kill adjacent bacteria and a wide range of cariogenic and periodontopathogenic bacteria has been shown to be susceptible to such agents. In the oral cavity these organisms are present as biofilms (dental plaques) which are less susceptible to traditional antimicrobial agents than bacterial suspensions. The results of these studies have shown that biofilm-grown oral bacteria are also susceptible to lethal photosensitization although the light energy doses required are grater than those needed to kill the organisms when they are grown as aqueous suspensions.

  2. Hydrodynamic interaction between bacteria and passive sphere

    Science.gov (United States)

    Zhang, Bokai; Ding, Yang; Xu, Xinliang

    2017-11-01

    Understanding hydrodynamic interaction between bacteria and passive sphere is important for identifying rheological properties of bacterial and colloidal suspension. Over the past few years, scientists mainly focused on bacterial influences on tracer particle diffusion or hydrodynamic capture of a bacteria around stationary boundary. Here, we use superposition of singularities and regularized method to study changes in bacterial swimming velocity and passive sphere diffusion, simultaneously. On this basis, we present a simple two-bead model that gives a unified interpretation of passive sphere diffusion and bacterial swimming. The model attributes both variation of passive sphere diffusion and changes of speed of bacteria to an effective mobility. Using the effective mobility of bacterial head and tail as an input function, the calculations are consistent with simulation results at a broad range of tracer diameters, incident angles and bacterial shapes.

  3. Ancient bacteria show evidence of DNA repair

    DEFF Research Database (Denmark)

    Johnson, Sarah Stewart; Hebsgaard, Martin B; Christensen, Torben R

    2007-01-01

    Recent claims of cultivable ancient bacteria within sealed environments highlight our limited understanding of the mechanisms behind long-term cell survival. It remains unclear how dormancy, a favored explanation for extended cellular persistence, can cope with spontaneous genomic decay over......-term survival of bacteria sealed in frozen conditions for up to one million years. Our results show evidence of bacterial survival in samples up to half a million years in age, making this the oldest independently authenticated DNA to date obtained from viable cells. Additionally, we find strong evidence...... that this long-term survival is closely tied to cellular metabolic activity and DNA repair that over time proves to be superior to dormancy as a mechanism in sustaining bacteria viability....

  4. Widespread Oceanospirillaceae Bacteria in Porites spp.

    Directory of Open Access Journals (Sweden)

    Mark D. Speck

    2012-01-01

    Full Text Available We present evidence that a clade of bacteria in the Oceanospirillaceae is widely distributed in Porites spp. and other hermatypic corals. Bacteria 16S rDNA clone libraries were prepared from community genomic DNA extracted from Porites compressa and Porites lobata surface mucus and adjacent seawater collected along a line transect off Maui. Phylogenetic affiliations of operational taxonomic units (OTUs defined at the 97% level of nucleotide identity varied within and between the respective Porites spp. along the transect and differed from those in the seawater. One OTU (C7-A01, however, occurred in all mucus samples from both Porites species. C7-A01c affiliates with a clade of uncultivated Oceanospirillum-like bacteria; the nearest neighbors of this OTU have been reported only in the surface mucus layer of Porites spp. and other stony corals, in reef-dwelling invertebrates, and the corallivorous six-banded angelfish, Pomacanthus sexstriatus.

  5. Bacteriocins From Lactic Acid Bacteria: Interest For Food Products Biopreservation

    OpenAIRE

    Dortu, C.; Thonart, Philippe

    2009-01-01

    Bacteriocins from lactic acid bacteria: interest for food products biopreservation. Bacteriocins from lactic acid bacteria are low molecular weight antimicrobial peptides. They have inhibitory activity against the bacteria that are closed related to the producer strains and a narrow inhibitory spectrum. Nevertheless, most of them have activity against some food-born pathogenic bacteria as Listeria monocytogenes. The application of bacteriocins or bacteriocin producing lactic acid bacteria in ...

  6. Using Fluorescent Viruses for Detecting Bacteria in Water

    Science.gov (United States)

    Tabacco, Mary Beth; Qian, Xiaohua; Russo, Jaimie A.

    2009-01-01

    A method of detecting water-borne pathogenic bacteria is based partly on established molecular-recognition and fluorescent-labeling concepts, according to which bacteria of a species of interest are labeled with fluorescent reporter molecules and the bacteria can then be detected by fluorescence spectroscopy. The novelty of the present method lies in the use of bacteriophages (viruses that infect bacteria) to deliver the fluorescent reporter molecules to the bacteria of the species of interest.

  7. Rapid detection of bacteria by carbon quantum dots.

    Science.gov (United States)

    Mandal, Tapas K; Parvin, Nargish

    2011-12-01

    This work demonstrated a fluorescence measurement method for rapid detection of bacteria and their counting by using water-soluble carbon quantum dots (CQDs) as a fluorescence marker while sewage water bacteria were detection target bacteria. Highly luminescent water-soluble CQDs were prepared by carbonizing waste part of rice straw materials in a furnace under in-sufficient air flow. Bacteria in a LB media with count the total number of bacteria within a shortest time from any sample of environment.

  8. Bacteriophages: The Enemies of Bad Bacteria Are Our Friends!

    OpenAIRE

    Gutiérrez, Diana; Fernández, Lucía; Martínez, Beatriz; Rodríguez, Ana; García, Pilar

    2017-01-01

    Some bacteria can enter the human body and make people ill. Usually, these diseases can be cured by antibiotics, but sometimes bacteria are resistant to them, meaning that the antibiotics do not kill the bacteria. In these cases, bacteria become very dangerous. Bacteriophages are viruses that infect bacteria but are harmless to humans. To reproduce, they get into a bacterium, where they multiply, and finally they break the bacterial cell open to release the new viruses. Therefore, bacteriopha...

  9. Evaluación de la cognición social y teoría de la mente en pacientes con enfermedad cerebelosa degenerativa aislada no dementes Social cognition and theory of mind assessment in non-demented patients with isolated cerebellar degeneration

    Directory of Open Access Journals (Sweden)

    Carlos G. Abel

    2007-06-01

    Full Text Available OBJETIVO: Investigar la hipótesis según la cual, el cerebelo podría participar en las alteraciones de la cognición social (CS. MÉTODO: Se administraron tests neuropsicológicos generales, de función ejecutiva (FE, de CS que evaluaban la capacidad de inferir el estado mental de otras personas y la escala de Depresión de Beck a 10 pacientes adultos con enfermedad cerebelosa adquirida aislada (GEC y a 10 controles (GCO apareados por edad, sexo y educación. Se analizaron los datos mediante ANOVA y correlación. RESULTADOS: El GEC obtuvo puntajes significativamente menores (p?0,05 que el grupo GCO en tareas de FE (Test de Wisconsin y preguntas de creencia (PCr de Teoría de la Mente (ToM. El rendimiento en las preguntas de control (PCo de ToM fue similar en ambos grupos. El menor rendimiento en las PCr correlacionó significativamente con una menor habilidad conceptual, la severidad de la apatía (NPI y de la ataxia estática. Las PCo correlacionaron con medidas de atención y de recuerdo diferido libre. CONCLUSÍON: El cerebelo contribuiría en el monitoreo de la conducta mediante el control de datos multimodales motores, cognitivos y emocionales.AIM: To investigate whether the cerebellum could participate in social cognition (SC. METHOD: General neuropsychological tests, executive tests (EF, social cognition tests, which assess the ability to infer other peoples’ mental states, and the Beck Depression Inventory were given to 10 non-demented patients with isolated cerebellar degenerative disease, and to 10 healthy controls matched for sex, age, and years of education. ANOVA and correlation coefficients were employed for the statistical analysis. RESULTS: Patients within the cerebellar group were significantly impaired (p?0.05 in EF test [Wisconsin Card Sorting Test (WSCT] and belief questions (BQ from Theory of Mind (ToM tests. Performance in control questions (CQ from ToM tests was similar for both groups. Lower scores in BQ correlated

  10. Distribución de grupos filogenéticos y factores de virulencia en cepas de Escherichia coli uropatógena productora de ß-lactamasa CTX-M-15 aisladas de pacientes de la comunidad en Mérida, Venezuela

    Directory of Open Access Journals (Sweden)

    Ysheth Millán

    Full Text Available En este estudio se determinó el perfil de distribución de grupos filogéneticos y la detección genética de factores de virulencia en cepas de Escherichia coli uropatógena (ECUP productoras de ß-lactamasa CTX-M-15. Veintiocho cepas fueron aisladas de pacientes con infección del tracto urinario (ITU que asistieron al Laboratorio de Salud Pública del estado Mérida, Venezuela, durante el lapso comprendido entre enero 2009 y julio 2011. La determinación de los grupos filogenéticos y la detección de seis genes de virulencia, fimH, fyuA, kpsMTII, usp, PAI y papAH, se realizó mediante amplificación por PCR. Quince cepas de 28 se ubicaron principalmente en el filogrupo A, seguidos por el B2 (12/28 y D (1/28. No se observó una relación directa entre la recurrencia o gravedad de la ITU y la distribución de los filogrupos. Todos los factores de virulencia estudiados se encontraron con la frecuencia más alta en el grupo B2. El perfil de virulencia prevalente estuvo conformado por la asociación de tres genes principales: fimH, fyuA y kpsMTII y en menor frecuencia, por la presencia de otros determinantes como usp, PAI y/o papAH. Estos resultados indican que la mayoría de ECUP estuvieron dotadas de tres propiedades virulentas importantes: adhesión, captación de hierro y evasión de la fagocitosis, las cuales favorecieron la producción de ITU recurrentes. Este es el primer trabajo que describe la asociación de grupos filogenéticos con el potencial de virulencia de cepas de ECUP productoras de ß-lactamasa CTX-M-15 en Venezuela.

  11. Functional Encyclopedia of Bacteria and Archaea

    Energy Technology Data Exchange (ETDEWEB)

    Blow, M. J.; Deutschbauer, A. M.; Hoover, C. A.; Lamson, J.; Lamson, J.; Price, M. N.; Waters, J.; Wetmore, K. M.; Bristow, J.; Arkin, A. P.

    2013-03-20

    Bacteria and Archaea exhibit a huge diversity of metabolic capabilities with fundamental importance in the environment, and potential applications in biotechnology. However, the genetic bases of these capabilities remain unclear due largely to an absence of technologies that link DNA sequence to molecular function. To address this challenge, we are developing a pipeline for high throughput annotation of gene function using mutagenesis, growth assays and DNA sequencing. By applying this pipeline to annotate gene function in 50 diverse microbes we hope to discover thousands of new gene functions and produce a proof of principle `Functional Encyclopedia of Bacteria and Archaea?.

  12. DNA Barcoding on Bacteria: A Review

    Directory of Open Access Journals (Sweden)

    D. E. Lebonah

    2014-01-01

    Full Text Available Bacteria are omnipotent and they can be found everywhere. The study of bacterial pathogens has been happening from olden days to prevent epidemics, food spoilage, losses in agricultural production, and loss of lives. Modern techniques in DNA based species identification are considered. So, there is a need to acquire simple and quick identification technique. Hence, this review article covers the efficacy of DNA barcoding of bacteria. Routine DNA barcoding involves the production of PCR amplicons from particular regions to sequence them and these sequence data are used to identify or “barcode” that organism to make a distinction from other species.

  13. 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.

  14. Bacteria Provide Cleanup of Oil Spills, Wastewater

    Science.gov (United States)

    2010-01-01

    Through Small Business Innovation Research (SBIR) contracts with Marshall Space Flight Center, Micro-Bac International Inc., of Round Rock, Texas, developed a phototrophic cell for water purification in space. Inside the cell: millions of photosynthetic bacteria. Micro-Bac proceeded to commercialize the bacterial formulation it developed for the SBIR project. The formulation is now used for the remediation of wastewater systems and waste from livestock farms and food manufacturers. Strains of the SBIR-derived bacteria also feature in microbial solutions that treat environmentally damaging oil spills, such as that resulting from the catastrophic 2010 Deepwater Horizon oil rig explosion in the Gulf of Mexico.

  15. ISOLATION OF OBLIGATELY ANAEROBIC PSYCHROPHILIC BACTERIA.

    Science.gov (United States)

    SINCLAIR, N A; STOKES, J L

    1964-03-01

    Sinclair, N. A. (Washington State University, Pullman), and J. L. Stokes. Isolation of obligately anaerobic psychrophilic bacteria. J. Bacteriol. 87:562-565. 1964.-A total of 11 strains of strictly anaerobic psychrophilic bacteria have been isolated from soil, mud, and sewage. The organisms grow well at 0 C in liquid and on solid media, and grow only in the complete absence of oxygen. On the basis of shape, sporulation, flagellation, and strictly anaerobic growth, all of the organisms were classified as strains of Clostridium. Some of the biochemical properties of the strains and the effect of temperature on growth are described.

  16. Bacteria-Triggered Release of Antimicrobial Agents

    DEFF Research Database (Denmark)

    Komnatnyy, Vitaly V.; Chiang, Wen-Chi; Tolker-Nielsen, Tim

    2014-01-01

    Medical devices employed in healthcare practice are often susceptible to microbial contamination. Pathogenic bacteria may attach themselves to device surfaces of catheters or implants by formation of chemically complex biofilms, which may be the direct cause of device failure. Extracellular...... material is demonstrated by the bacteria‐triggered release of antibiotics to control bacterial populations and signaling molecules to modulate quorum sensing. The self‐regulating system provides the basis for the development of device‐relevant polymeric materials, which only release antibiotics...... in dependency of the titer of bacteria surrounding the medical device....

  17. Bacteria in crude oil survived autoclaving and stimulated differentially by exogenous bacteria.

    Directory of Open Access Journals (Sweden)

    Xiao-Cui Gong

    Full Text Available Autoclaving of crude oil is often used to evaluate the hydrocarbon-degrading abilities of bacteria. This may be potentially useful for bioaugmentation and microbial enhanced oil recovery (MEOR. However, it is not entirely clear if "endogenous" bacteria (e.g., spores in/on crude oil survive the autoclaving process, or influence subsequent evaluation of the hydrocarbon-degradation abilities of the "exogenous" bacterial strains. To test this, we inoculated autoclaved crude oil medium with six exogenous bacterial strains (three Dietzia strains, two Acinetobacter strains, and one Pseudomonas strain. The survival of the spore-forming Bacillus and Paenibacillus and the non-spore-forming mesophilic Pseudomonas, Dietzia, Alcaligenes, and Microbacterium was detected using a 16S rRNA gene clone library and terminal restriction fragment length polymorphism (T-RFLP analysis. However, neither bacteria nor bacterial activity was detected in three controls consisting of non-inoculated autoclaved crude oil medium. These results suggest that detection of endogenous bacteria was stimulated by the six inoculated strains. In addition, inoculation with Acinetobacter spp. stimulated detection of Bacillus, while inoculation with Dietzia spp. and Pseudomonas sp. stimulated the detection of more Pseudomonas. In contrast, similar exogenous bacteria stimulated similar endogenous bacteria at the genus level. Based on these results, special emphasis should be applied to evaluate the influence of bacteria capable of surviving autoclaving on the hydrocarbon-degrading abilities of exogenous bacteria, in particular, with regard to bioaugmentation and MEOR. Bioaugmentation and MEOR technologies could then be developed to more accurately direct the growth of specific endogenous bacteria that may then improve the efficiency of treatment or recovery of crude oil.

  18. Characterization of potential probiotic bacteria isolated from ...

    African Journals Online (AJOL)

    Characterization of potential probiotic bacteria isolated from sorghum and pearl millet of the semi-arid tropics. ... A total of nine probiotic bacterial isolates were short listed based on these traits. The sequences of 16s rDNA gene ... probiotic foods. Key words: Probiotics, prebiotics, sorghum, pearl millet, product development.

  19. On Bunsen Burners, Bacteria and the Bible

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 2. On Bunsen Burners, Bacteria and the Bible. Milind Watve. Classroom Volume 1 Issue 2 February 1996 pp 84-89. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/001/02/0084-0089 ...

  20. Prevalence, histopathological findings and aerobic bacteria flora ...

    African Journals Online (AJOL)

    Aerobic bacteria isolated from the lungs with pneumopathies were E. coli, Klebsiella pneumoniae, Mannheimia haemolytica, Streptococcus pyogenes, Staphylococcus aureus, Bacillus subtilis, Proteus vulgaris and Pasteurella multocida. E. coli with a prevalence rate of 73.5% was the most predominant isolate. There was ...

  1. Antibiotic Resistance of Bacteria: A Global Challenge

    Indian Academy of Sciences (India)

    vealed several aminoglycoside resistances in nonculturable bac- teria. Notwithstanding the availability of so many antimicrobial agents, infectious diseases still remain the second leading cause of death worldwide. Eventually, the widespread occurrence of antibiotic-resistant bacteria has added a new dimension to the.

  2. Polyphasic taxonomic characterization of lactic acid bacteria ...

    African Journals Online (AJOL)

    Polyphasic taxonomic characterization of lactic acid bacteria isolated from spontaneous sorghum fermentations used to produce ting, a traditional South African food. ... The results of these analyses showed that ting fermentation involved at least three different species of LAB, i.e. Lactobacillus fermentum, L. plantarum

  3. Stress physiology of lactic acid bacteria

    NARCIS (Netherlands)

    Papadimitriou, Konstantinos; Alegría, Ángel; Bron, Peter A.; Angelis, De Maria; Gobbetti, Marco; Kleerebezem, Michiel; Lemos, José A.; Linares, Daniel M.; Ross, Paul; Stanton, Catherine; Turroni, Francesca; Sinderen, Van Douwe; Varmanen, Pekka; Ventura, Marco; Zúñiga, Manuel; Tsakalidou, Effie; Kok, Jan

    2016-01-01

    Lactic acid bacteria (LAB) are important starter, commensal, or pathogenic microorganisms. The stress physiology of LAB has been studied in depth for over 2 decades, fueled mostly by the technological implications of LAB robustness in the food industry. Survival of probiotic LAB in the host and

  4. Stress Physiology of Lactic Acid Bacteria

    NARCIS (Netherlands)

    Papadimitriou, Konstantinos; Alegría, Ángel; Bron, Peter A; de Angelis, Maria; Gobbetti, Marco; Kleerebezem, Michiel; Lemos, José A; Linares, Daniel M; Ross, Paul; Stanton, Catherine; Turroni, Francesca; van Sinderen, Douwe; Varmanen, Pekka; Ventura, Marco; Zúñiga, Manuel; Tsakalidou, Effie; Kok, Jan

    Lactic acid bacteria (LAB) are important starter, commensal, or pathogenic microorganisms. The stress physiology of LAB has been studied in depth for over 2 decades, fueled mostly by the technological implications of LAB robustness in the food industry. Survival of probiotic LAB in the host and the

  5. Reflections Lederberg and the 'Cellularity' of Bacteria

    Indian Academy of Sciences (India)

    Srimath

    He tried to observe bacterial mating and the details of conjugation at the cellular level [3]. (reproduced in the Classics section), processes that are still being investigated [4]. He made the important discovery that penicillin induces the formation of spheroplasts. The announcing. Lederberg and the 'Cellularity' of Bacteria.

  6. Assessment of indigenous bacteria from biodiesel effluents ...

    African Journals Online (AJOL)

    This study was conducted in order to identify indigenous microorganisms which have the capability to degrade biodiesel contaminated sites. Bacterial isolates were identified on the basis of morphological and biochemical characterization in which nine bacteria were isolated from the site, Staphylococcus aureus and ...

  7. Anhydrobiosis in bacteria: From physiology to applications

    Indian Academy of Sciences (India)

    With regard to the desiccation tolerance in bacteria, although many mechanisms remain undiscovered at the molecular level, important research about the physiology of the anhydrobiotic state and its applications has been performed, and here we provide the most recent information about this subject. On the other hand, the ...

  8. Chitinolytic bacteria of the mammal digestive tract

    Czech Academy of Sciences Publication Activity Database

    Šimůnek, Jiří; Hodrová, Blanka; Bartoňová, H.; Kopečný, Jan

    2001-01-01

    Roč. 46, č. 1 (2001), s. 76-78 ISSN 0015-5632 R&D Projects: GA ČR GA525/00/0984; GA AV ČR KSK5052113 Keywords : chitinolytic bacteria Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.776, year: 2001

  9. Filamentous bacteria transport electrons over centimetre distances

    DEFF Research Database (Denmark)

    Pfeffer, Christian; Larsen, Steffen; Song, Jie

    2012-01-01

    across centimetre-wide zones. Here we present evidence that the native conductors are long, filamentous bacteria. They abounded in sediment zones with electric currents and along their length they contained strings with distinct properties in accordance with a function as electron transporters. Living...

  10. Control of indigenous pathogenic bacteria in seafood

    DEFF Research Database (Denmark)

    Huss, Hans Henrik

    1997-01-01

    The pathogenic bacteria indigenous to the aquatic and general environment are listed. Their distribution in nature, prevalence in seafood and the possibilities for growth of these organisms in various types of products are outlined These data, combined with what is known regarding the epidemiology...

  11. Biological Potential of Chitinolytic Marine Bacteria

    DEFF Research Database (Denmark)

    Paulsen, Sara Skøtt; Andersen, Birgitte; Gram, Lone

    2016-01-01

    Chitinolytic microorganisms secrete a range of chitin modifying enzymes, which can be exploited for production of chitin derived products or as fungal or pest control agents. Here, we explored the potential of 11 marine bacteria (Pseudoalteromonadaceae, Vibrionaceae) for chitin degradation using...

  12. Bioluminescent hydrocarbonclastic bacteria of the Niger Delta

    African Journals Online (AJOL)

    Administrator

    2007-02-19

    Feb 19, 2007 ... Utilization of three petroleum hydrocarbons (Mobil SAE 40 Engine Oil, Diesel and Bonny light Crude. Oil) by four ... growth of hydrocarbonoclastic bioluminescent bacteria which could serve as a potential tool for the remediation of petroleum ... lized TNT. In the Niger Delta, increasing petroleum exploration.

  13. Genetics of proteinases of lactic acid bacteria

    NARCIS (Netherlands)

    Kok, Jan; Venema, Gerhardus

    Because it is essential for good growth with concomitant rapid acid production, and for the production of flavorous peptides and amino acids, the proteolytic ability of lactic acid bacteria is of crucial importance for reliable dairy product quality. In view of this importance, considerable research

  14. On Bunsen Burners, Bacteria and the Bible

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 2. On Bunsen Burners, Bacteria and the Bible. Milind Watve. Classroom Volume 1 Issue 2 February 1996 pp 84-89. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/001/02/0084-0089 ...

  15. Identification of bacteria using mass spectrometry techniques

    Czech Academy of Sciences Publication Activity Database

    Krásný, Lukáš; Hynek, R.; Hochel, I.

    2013-01-01

    Roč. 353, NOV 2013 (2013), s. 67-79 ISSN 1387-3806 R&D Projects: GA ČR GAP503/10/0664 Institutional support: RVO:61388971 Keywords : Mass spectrometry * Bacteria * Identification Subject RIV: EE - Microbiology, Virology Impact factor: 2.227, year: 2013

  16. (Transport of subsurface bacteria in porous media)

    Energy Technology Data Exchange (ETDEWEB)

    1992-01-01

    This report describes studies undertaken to better understand basic microbiology of deep underground regions with special reference to Savannah River Plant. The studies related herein describe studies to enhance sampling methods of deep aquifers and soil columns, to develop equipment to better understand the migration of bacteria in deep soils, and to improve methods to culturing and maintaining deep isolates.

  17. [Transport of subsurface bacteria in porous media

    Energy Technology Data Exchange (ETDEWEB)

    1992-08-01

    This report describes studies undertaken to better understand basic microbiology of deep underground regions with special reference to Savannah River Plant. The studies related herein describe studies to enhance sampling methods of deep aquifers and soil columns, to develop equipment to better understand the migration of bacteria in deep soils, and to improve methods to culturing and maintaining deep isolates.

  18. Drug efflux proteins in multidrug resistant bacteria

    NARCIS (Netherlands)

    vanVeen, HW; Konings, WN

    Bacteria contain an array of transport proteins in their cytoplasmic membrane. Many of these proteins play an important role in conferring resistance to toxic compounds. The multidrug efflux systems encountered in prokaryotic cells are very similar to those observed in eukaryotic cells. Therefore, a

  19. Exopolysaccharides produced by lactic acid bacteria

    NARCIS (Netherlands)

    Caggianiello, Graziano; Kleerebezem, Michiel; Spano, Giuseppe

    2016-01-01

    A wide range of lactic acid bacteria (LAB) is able to produce capsular or extracellular polysaccharides, with various chemical compositions and properties. Polysaccharides produced by LAB alter the rheological properties of the matrix in which they are dispersed, leading to typically viscous and

  20. Role of Outer Membrane Vesicles of Bacteria

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 20; Issue 8. Role of Outer Membrance Vesicles of Bacteria. M V Jagannadham M K Chattopadhyay. General Article Volume 20 Issue 8 August 2015 pp 711-725. Fulltext. Click here to view fulltext PDF. Permanent link:

  1. Competitive interactions between sponge-associated bacteria.

    Science.gov (United States)

    Esteves, Ana I S; Cullen, Alescia; Thomas, Torsten

    2017-03-01

    The diversity of the microbial communities associated with marine sponges has been extensively studied, but their functioning and interactions within the sponge holobiont are only recently being appreciated. Sponge-associated microorganisms are known for the production of a range of inhibitory metabolites with biotechnological application, but the ecological role that these compounds remains elusive. In this work, we explore the competitive interactions between cultivated sponge-associated bacteria to inspect whether bacteria that produce antimicrobial activities are able to inhibit potentially pathogenic bacteria. We isolated a Bacillus sp. bacterium with sponge-degrading activity, which likely has a negative impact on the host. This bacterium, along with other sponge isolates from the same genus, was found to be inhibited by a subpopulation of closely related sponge-derived Pseudovibrio spp. In some Pseudovibrio strains, these inhibitory activities were correlated with the genetic capacity to produce polyketides, such as erythronolide. Our observations suggest that antagonistic activities likely influence the composition of the sponge microbiome, including the abundance of bacteria that can be harmful to the host. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  2. Biotechnological potential of sponge-associated bacteria.

    Science.gov (United States)

    Santos-Gandelman, Juliana F; Giambiagi-deMarval, Marcia; Oelemann, Walter M R; Laport, Marinella S

    2014-01-01

    As sessile and filter-feeding metazoans, marine sponges represent an ecologically important and highly diverse component of marine benthic communities throughout the world. It has been suggested that marine sponges are hosts to many microorganisms which can constitute up to 40-60% of its biomass. Recently, sponges have attracted a high interest from scientific community because two important factors. First there is the fact that sponges have a wide range of associated bacteria; and, second, they are a rich source of bioactive substances. Since 1950, a number of bioactive substances with various pharmacological functions have been isolated from marine sponges. However, many of these substances were subsequently shown to be actually synthesized by sponge-associated bacteria. Bacteria associated with marine sponges constitute an interesting source of novel bioactive compounds with biotechnological potential such as antimicrobial substances, enzymes and surfactants. In addition, these bacteria may be biofilm forming and can act as bioindicators in bioremediation processes of environmental pollution caused by oil and heavy metals. This review focuses on the biotechnological applications of these microorganisms.

  3. Separation, Purification and Identification of Bacteria

    African Journals Online (AJOL)

    user

    2011-05-16

    May 16, 2011 ... biochemical characteristics of the bacteria (Joseph et al., 2001). The common standard strains such as .... Berger's Manual of. Determinative Bacteriology. The Williams and Wilkins CO., Baltimore. (USA). Bruce E, Susan (1988). Recent advances in the development of an improved human anthrax vaccine.

  4. Freeze-drying of lactic acid bacteria.

    Science.gov (United States)

    Fonseca, Fernanda; Cenard, Stéphanie; Passot, Stéphanie

    2015-01-01

    Lactic acid bacteria are of great importance for the food and biotechnology industry. They are widely used as starters for manufacturing food (e.g., yogurt, cheese, fermented meats, and vegetables) and probiotic products, as well as for green chemistry applications. Freeze-drying or lyophilization is a convenient method for preservation of bacteria. By reducing water activity to values below 0.2, it allows long-term storage and low-cost distribution at suprazero temperatures, while minimizing losses in viability and functionality. Stabilization of bacteria via freeze-drying starts with the addition of a protectant solution to the bacterial suspension. Freeze-drying includes three steps, namely, (1) freezing of the concentrated and protected cell suspension, (2) primary drying to remove ice by sublimation, and (3) secondary drying to remove unfrozen water by desorption. In this chapter we describe a method for freeze-drying of lactic acid bacteria at a pilot scale, thus allowing control of the process parameters for maximal survival and functionality recovery.

  5. Probiotic bacteria may become dormant during storage.

    Science.gov (United States)

    Lahtinen, Sampo J; Gueimonde, Miguel; Ouwehand, Arthur C; Reinikainen, Johanna P; Salminen, Seppo J

    2005-03-01

    The determination of bacterial viability in probiotic products is of economic, technological, and clinical significance. We compared four methods to enumerate three Bifidobacterium strains in fermented oat products during storage. A subpopulation of nonculturable cells retained a functional cell membrane typical of viable cells, indicating that probiotic bacteria become dormant during storage.

  6. Probiotic Bacteria May Become Dormant during Storage

    OpenAIRE

    Lahtinen, Sampo J.; Gueimonde, Miguel; Ouwehand, Arthur C.; Reinikainen, Johanna P.; Salminen, Seppo J.

    2005-01-01

    The determination of bacterial viability in probiotic products is of economic, technological, and clinical significance. We compared four methods to enumerate three Bifidobacterium strains in fermented oat products during storage. A subpopulation of nonculturable cells retained a functional cell membrane typical of viable cells, indicating that probiotic bacteria become dormant during storage.

  7. [Innovative treatments for multidrug-resistant bacteria].

    Science.gov (United States)

    Pierre, Tattevin; Aurélien, Lorleac'h; Matthieu, Revest

    2014-03-01

    The spread of multidrug-resistant bacteria has accelerated sharply in the last decade. According to the World Health Organization they are responsible for an estimated 25 000 deaths in Europe each year. In addition, few new antibiotics are under development, raising the spectrum of a return to the "pre-antibiotic era". Non antibiotic antibacterial agents have recently attracted renewed interest. The most promising candidates are: i) phages (bacteria-infecting viruses) have been widely used in Eastern European countries since the 1930s but come up against logistic and regulatory obstacles due to the evolutionary nature of these biologic agents, while convincing clinical data are lacking; ii) bacteriocines are smallantibacterialpeptidesproducedby numerous bacteria; some have a rapid bactericidal effect, good tolerability, and a limited impact on the commensal flora; however, clinical use of bacteriocines is complicated by their fragility, poor penetration, and substantial risk of resistance selection ; iii) antisense oligonucleo tides act by inactivating genes through specific interaction with a complementary DNA or RNA fragment, potentially allowing specific inhibition of selected bacterial virulence factors. However, this therapeutic class may be more suitable for viral or genetic diseases than for multidrug-resistant bacterial infections, owing to the difficulty of delivering them inside bacteria.

  8. Antibiotic-Resistant Bacteria: There is Hope.

    Science.gov (United States)

    Offner, Susan

    1998-01-01

    Argues that reduction in the use of antibiotics would enable antibiotic-sensitive bacteria to flourish. Presents an activity designed to show students how a small, seemingly unimportant difference in doubling time can, over a period of time, make an enormous difference in population size. (DDR)

  9. Why engineering lactic acid bacteria for biobutanol

    Science.gov (United States)

    The Gram-positive Lactic acid bacteria (LAB) are considered attractive biocatalysts for biomass to biofuels for several reasons. They have GRAS (Generally Recognized As Safe) status that are acceptable in food, feed, and medical applications. LAB are fermentative: selected strains are capable of f...

  10. Manganese Oxidation by Bacteria: Biogeochemical Aspects

    Digital Repository Service at National Institute of Oceanography (India)

    Sujith, P.P.; LokaBharathi, P.A.

    to oxygen in the aquatic environment and therefore control the fate of several elements. Mn oxidizing bacteria have a suit of enzymes that not only help to scavenge Mn but also other associated elements, thus playing a crucial role in biogeochemical cycles...

  11. The proteolytic system of lactic acid bacteria.

    Science.gov (United States)

    Mayo, B

    1993-12-01

    Lactic acid bacteria are widely used throughout the world, empirically or deliberately, in the manufacturing of several food and feed stuffs, including milk products (such as cheese, butter, yoghurt, buttermilk, etc.), fermented vegetables (pickles, olives and sauerkraut), sausages, sourdough bread and silage, due to their ability to convert sugars into lactic acid. Of these, dairy products are of outstanding economic importance. Starter cultures used in the dairy industry are mixtures of carefully selected lactic acid bacteria which are added to the milk to fulfil the desired fermentation. Dairy starter cultures must reach high densities in milk in order to produce lactic acid at the required rates for manufacturing. Under these conditions, amino acids supply becomes limitant due to their scarce concentration in milk and to the auxotrophies shown by many starter bacteria. This implies the necessity of a proteolytic system, able to degrade the most abundant protein in milk, casein, into assimilable amino acids and peptides. Casein degradation and utilization require the concerted action of proteinases, peptidases and amino acid and peptide uptake systems. This whole set of enzymes constitutes the proteolytic system. In this article an overview of the recent biochemical and genetic data on the proteolytic system of lactic acid bacteria will be presented.

  12. NOTE: Survivability of Bacteria in Hypervelocity Impact

    Science.gov (United States)

    Burchell, Mark J.; Mann, Jo; Bunch, Alan W.; Brandão, Pedro F. B.

    2001-12-01

    Bacteria belonging to the genus Rhodococcus have been tested for their survivability in hypervelocity impacts at 5.1±0.1 km s -1. This is similar to the martian escape velocity for example but is slower than the mean velocities typical of impacts from space on planets like Mars (typically 14 km s -1) and Earth (typically 20-25 km s -1). The bacteria fired were loaded on a projectile using a two-stage light-gas gun. The targets were plates of nutrient media. Analysis techniques including pyrolysis mass spectrometry and selective growth in acetonitrile confirmed that the bacterium grown on a target plate after a shot was the original strain. The indication is that, if fired on a projectile, bacteria can survive a hypervelocity impact and subsequently grow. This holds implications for the study of possible natural migration of life around the Solar System on minor bodies which end up impacting target planets, thus transferring life if the bacteria can survive the resulting hypervelocity impact.

  13. Phytase activity in rabbit cecal bacteria

    Czech Academy of Sciences Publication Activity Database

    Marounek, Milan; Břeňová, Natalia; Suchorská, O.; Mrázek, Jakub

    2009-01-01

    Roč. 54, č. 2 (2009), s. 111-114 ISSN 0015-5632 R&D Projects: GA ČR GA523/07/0673 Institutional research plan: CEZ:AV0Z50450515 Keywords : rabbit * cecal bacteria Subject RIV: GH - Livestock Nutrition Impact factor: 0.978, year: 2009

  14. Molecular approaches to study probiotic bacteria

    NARCIS (Netherlands)

    Vaughan, E.E.; Heilig, G.H.J.; Zoetendal, E.G.; Satokari, R.; Collins, J.K.; Akkermans, A.D.L.; Vos, de W.M.

    2000-01-01

    Functional foods comprising probiotic bacteria are receiving increasing attention from the scientific community and science funding agencies [1]. An essential aspect relating to the functionality of probiotic-based foods is to develop molecular methods to determine the presence, activity and

  15. Bioluminescent hydrocarbonclastic bacteria of the Niger Delta ...

    African Journals Online (AJOL)

    Utilization of three petroleum hydrocarbons (Mobil SAE 40 Engine Oil, Diesel and Bonny light Crude Oil) by four bioluminescent bacteria (Vibrio harveyi, V. fisheri, Photobacterium leiognathi and P. Phosphoreum isolated from the Bonny estuary in the Niger Delta, Nigeria was investigated. Microbial utilization was monitored ...

  16. Pathomorphology and aerobic bacteria associated with pneumonia ...

    African Journals Online (AJOL)

    Pneumonia occurs in all ages of sheep and goats, in all breeds, in every country of the world causing heavy economic losses. The aim of this study was to determine the prevalence of pneumonia and aerobic bacteria flora associated with it in small ruminants slaughtered at the Nsukka abattoir. Pneumonic lung of small ...

  17. Isolation of biosurfactant-producing marine bacteria

    African Journals Online (AJOL)

    user

    2012-06-06

    Jun 6, 2012 ... Biosurfactant-producing marine bacteria were isolated from oil-spilled seawater collected from harbors and docks in Mumbai, India. ... pollution of the environment especially soil and water. A spill of over 800 tonnes of oil .... substrates (agro-industrial wastes) and efficient methods for cultivation of microbes ...

  18. The proteolytic systems of lactic acid bacteria

    NARCIS (Netherlands)

    Kunji, Edmund R.S.; Mierau, Igor; Hagting, Anja; Poolman, Bert; Konings, Wil N.

    1996-01-01

    Proteolysis in dairy lactic acid bacteria has been studied in great detail by genetic, biochemical and ultrastructural methods. From these studies the picture emerges that the proteolytic systems of lactococci and lactobacilli are remarkably similar in their components and mode of action. The

  19. Proteolytic enzymes of lactic acid bacteria

    NARCIS (Netherlands)

    Law, J; Haandrikman, A

    The proteolytic system of lactic acid bacteria is essential for their growth in milk and contributes significantly to flavour development in fermented milk products where these microorganisms are used as starter cultures. The proteolytic system is composed of proteinases which initially cleave the

  20. Seeing Streptococcus pneumoniae, a Common Killer Bacteria

    DEFF Research Database (Denmark)

    Kjærgaard, Rikke Schmidt; Andersen, Ebbe Sloth

    2014-01-01

    of the bacteria Streptococcus pneumoniae by use of ink, watercolours and computer graphics. We propose a novel artistic visual rendering of Streptococcus pneumoniae and ask what the value of these kind of representations are compared to traditional scientific data. We ask if drawings and computer...

  1. Hypermutation and stress adaptation in bacteria

    Indian Academy of Sciences (India)

    2011-08-19

    Aug 19, 2011 ... [Jayaraman R. 2011 Hypermutation and stress adaptation in bacteria. J. Genet. 90, 383–391]. Introduction. Adaptive evolution by natural selection depends upon the supply of mutations, especially beneficial mutations. (reviewed by Sniegowski and Gerrish 2010). Generally, spontaneous mutation rates are ...

  2. Fermentation of D-Tagatose by Human Intestinal Bacteria and Dairy Lactic Acid Bacteria

    OpenAIRE

    Bertelsen, Hans; Andersen, Hans; Tvede, Michael

    2011-01-01

    A number of 174 normal or pathogenic human enteric bacteria and dairy lactic acid bacteria were screened for D-tagatose fermentation by incubation for 48 hours. Selection criteria for fermentation employed included a drop in pH below 5.5 and a distance to controls of more than 0.5. Only a few of the normal occurring enteric human bacteria were able to ferment D-tagatose, among those Enterococcus faecalis, Enterococcus faecium and Lactobacillus strains. D-Tagatose fermentation seems to be comm...

  3. Effects of symbiotic bacteria on chemical sensitivity of Daphnia magna.

    Science.gov (United States)

    Manakul, Patcharaporn; Peerakietkhajorn, Saranya; Matsuura, Tomoaki; Kato, Yasuhiko; Watanabe, Hajime

    2017-07-01

    The crustacean zooplankton Daphnia magna has been widely used for chemical toxicity tests. Although abiotic factors have been well documented in ecotoxicological test protocols, biotic factors that may affect the sensitivity to chemical compounds remain limited. Recently, we identified symbiotic bacteria that are critical for the growth and reproduction of D. magna. The presence of symbiotic bacteria on Daphnia raised the question as to whether these bacteria have a positive or negative effect on toxicity tests. In order to evaluate the effects of symbiotic bacteria on toxicity tests, bacteria-free Daphnia were prepared, and their chemical sensitivities were compared with that of Daphnia with symbiotic bacteria based on an acute immobilization test. The Daphnia with symbiotic bacteria showed higher chemical resistance to nonylphenol, fenoxycarb, and pentachlorophenol than bacteria-free Daphnia. These results suggested potential roles of symbiotic bacteria in the chemical resistance of its host Daphnia. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Capacidade aerobia de futebolistas profissionais de altitude durante o periodo competitivo da cidade de Arequipa-Peru

    OpenAIRE

    Alejandro Inostroza Aeloiza

    2004-01-01

    Resumo: O objetivo do presente estudo foi de descrever e analisar a capacidade aeróbia de futebolistas profissionais de altitude durante o período competitivo, onde a seleção da amostra foi de tipo não-probabilístico 27 jogadores, para tal efeito, foram mensuradas as variáveis de massa corporal, estatura, quatro dobras cutâneas (triciptal, subescapular, supra- Ilíaca, e panturrilha), e para a capacidade aeróbia progressiva foi utilizado o teste físico de (corrida de ida e volta de 20m) de Nav...

  5. Counting small RNA in pathogenic bacteria.

    Science.gov (United States)

    Shepherd, Douglas P; Li, Nan; Micheva-Viteva, Sofiya N; Munsky, Brian; Hong-Geller, Elizabeth; Werner, James H

    2013-05-21

    Here, we present a modification to single-molecule fluorescence in situ hybridization that enables quantitative detection and analysis of small RNA (sRNA) expressed in bacteria. We show that short (~200 nucleotide) nucleic acid targets can be detected when the background of unbound singly dye-labeled DNA oligomers is reduced through hybridization with a set of complementary DNA oligomers labeled with a fluorescence quencher. By neutralizing the fluorescence from unbound probes, we were able to significantly reduce the number of false positives, allowing for accurate quantification of sRNA levels. Exploiting an automated, mutli-color wide-field microscope and data analysis package, we analyzed the statistics of sRNA expression in thousands of individual bacteria. We found that only a small fraction of either Yersinia pseudotuberculosis or Yersinia pestis bacteria express the small RNAs YSR35 or YSP8, with the copy number typically between 0 and 10 transcripts. The numbers of these RNA are both increased (by a factor of 2.5× for YSR35 and 3.5× for YSP8) upon a temperature shift from 25 to 37 °C, suggesting they play a role in pathogenesis. The copy number distribution of sRNAs from bacteria-to-bacteria are well-fit with a bursting model of gene transcription. The ability to directly quantify expression level changes of sRNA in single cells as a function of external stimuli provides key information on the role of sRNA in cellular regulatory networks.

  6. [Methanotrophic bacteria of acid sphagnum bogs].

    Science.gov (United States)

    Dedysh, S N

    2002-01-01

    Acid sphagnum bogs cover a considerable part of the territory of Russia and are an important natural source of biogenic methane, which is formed in their anaerobic layers. A considerable portion of this methane is consumed in the aerobic part of the bog profile by acidophilic methanotrophic bacteria, which comprise the methane filter of sphagnum bogs and decrease CH4 emission to the atmosphere. For a long time, these bacteria escaped isolation, which became possible only after the elucidation of the optimal conditions of their functioning in situ: pH 4.5 to 5.5; temperature, from 15 to 20 degrees C; and low salt concentration in the solution. Reproduction of these conditions and rejection of earlier used media with a high content of biogenic elements allowed methanotrophic bacteria of two new genera and species--Methylocella palustris and Methylocapsa acidophila--to be isolated from the peat of sphagnum bogs of the northern part of European Russia and West Siberia. These bacteria are well adapted to the conditions in cold, acid, oligotrophic sphagnum bogs. They grow in a pH range of 4.2-7.5 with an optimum at 5.0-5.5, prefer moderate temperatures (15-25 degrees C) and media with a low content of mineral salts (200-500 mg/l), and are capable of active nitrogen fixation. Design of fluorescently labeled 16S rRNA-targeted oligonucleotide probes for the detection of Methylocella palustris and Methylocapsa acidophila and their application to the analysis of sphagnum peat samples showed that these bacteria represent dominant populations of methanotrophs with a density of 10(5)-10(6) cells/g peat. In addition to Methylocella and Methylocapsa populations, one more abundant population of methanotrophs was revealed (10(6) cells/g peat), which were phylogenetically close to the genus Methylocystis.

  7. Antibacterial activity of silver-killed bacteria: the "zombies" effect

    Science.gov (United States)

    Wakshlak, Racheli Ben-Knaz; Pedahzur, Rami; Avnir, David

    2015-04-01

    We report a previously unrecognized mechanism for the prolonged action of biocidal agents, which we denote as the zombies effect: biocidally-killed bacteria are capable of killing living bacteria. The concept is demonstrated by first killing Pseudomonas aeruginosa PAO1 with silver nitrate and then challenging, with the dead bacteria, a viable culture of the same bacterium: Efficient antibacterial activity of the killed bacteria is observed. A mechanism is suggested in terms of the action of the dead bacteria as a reservoir of silver, which, due to Le-Chatelier's principle, is re-targeted to the living bacteria. Langmuirian behavior, as well as deviations from it, support the proposed mechanism.

  8. Identification of Lactic Acid Bacteria and Propionic Acid Bacteria using FTIR Spectroscopy and Artificial Neural Networks

    OpenAIRE

    Dziuba, Bartłomiej; Nalepa, Beata

    2012-01-01

    In the present study, lactic acid bacteria and propionic acid bacteria have been identified at the genus level with the use of artificial neural networks (ANNs) and Fourier transform infrared spectroscopy (FTIR). Bacterial strains of the genera Lactobacillus, Lactococcus, Leuconostoc, Streptococcus and Propionibacterium were analyzed since they deliver health benefits and are routinely used in the food processing industry. The correctness of bacterial identification by ANNs and FTIR was evalu...

  9. Ascitis fetal masiva idiopática aislada

    Directory of Open Access Journals (Sweden)

    Yolimar Navarro Briceño

    2016-08-01

    Full Text Available La ascitis fetal esta comúnmente asociada a malformaciones gastrointestinales y urinarias, anemia, infección y anomalías cromosómicas. La ascitis fetal masiva idiopática es rara. Se reporta un caso de una embarazada de 33 años referida a las 17 semanas después que se detectó ascitis en ausencia de anomalías estructurales. La evaluación cardiaca y las pruebas diagnósticas de infecciones virales fueron negativas. A las 28 semanas se detectó ascitis masiva sin otros signos de hidrops fetal. La velocidad sistólica pico de la arteria cerebral media fetal estaba elevada. El Doppler de la arteria umbilical, crecimiento fetal y volumen de líquido amniótico estaban normales. El ecocardiograma fetal estaba normal. Se realizó la amniocentesis con resultados normales del cariotipo. A pesar de la persistencia de la ascitis masiva durante el seguimiento, el crecimiento fetal y el volumen de líquido amniótico eran normales con valores elevados de la velocidad sistólica pico de la arteria cerebral media fetal. A las 33 semanas la paciente se realizó cesárea de emergencia por sufrimiento fetal agudo. Se obtuvo un recién nacido vivo femenino normal con valores normales de hemoglobina al nacer. El flujo vascular hepático, vesical y hepato-portal fueron normales. La ascitis se resolvió completamente al octavo día después del nacimiento y el recién nacido fue dado de alta a los 15 días.

  10. Estudio Clínico de las Craneostenosis Aisladas.

    OpenAIRE

    López Castilla, José Domingo

    2017-01-01

    La Craneostenosis es una anomalía congénita o adquirida de la bóveda craneal, que se acompaña de osificación prematura de una o varias suturas, lo que dificulta la expansión de la masa cerebral y da lugar a una forma anormal de la cabeza. Se produce una inhibición del desarrollo de la bóveda craneal en dirección perpendicular a la sutura estenosada, con crecimiento exagerado paralelo a la sutura afectada. A pesar de los estudi...

  11. Oh What a Tangled Biofilm Web Bacteria Weave

    Science.gov (United States)

    ... Home Page Oh What a Tangled Biofilm Web Bacteria Weave By Elia Ben-Ari Posted May 1, ... a suitable surface, some water and nutrients, and bacteria will likely put down stakes and form biofilms. ...

  12. Profiling urinary tract infections bacteria among elderly population in ...

    African Journals Online (AJOL)

    UTIs) causing bacteria in elderly in recent times. This study aims to evaluate the prevalence and resistance pattern of UTIs causing bacteria in elderly Nigerian patients. A prospective cross-sectional study was carried out among elderly ...

  13. Surveillance of multidrug resistant bacteria pathogens from female ...

    African Journals Online (AJOL)

    Highest sensitivity was observed with gatifloxacin, imipenam and piperacillin and tazobactum. Thus, according to this study, these antibiotics can be recommended against multi drug resistant bacteria pathogens. Keywords: Multidrug resistance, female infertility, bacteria pathogens. African Journal of Biotechnology Vol.

  14. Isolation and characterization of culturable bacteria from bulk soil ...

    African Journals Online (AJOL)

    The bacteria were screened for their ability to solubilise phosphates, for aminocyclopropane-1-carboxylate (ACC) deaminase activity, production of catalase, hydrogen cyanide, ammonia and protease activity. Efficiency of phosphate solubilising activity by bacteria was determined by phosphate solubilisation index.

  15. Developing new bacteria subroutines in the SWAT model

    Science.gov (United States)

    Fecal bacteria observations from four different sites in Korea and the US demonstrate seasonal variability, showing a significant relationship with temperature (Figure 1); fecal indicator bacteria (FIB) concentrations are relatively higher in summer and lower in winter , including Stillwater river (...

  16. Mimicking Seawater For Culturing Marine Bacteria

    DEFF Research Database (Denmark)

    Rygaard, Anita Mac; Sonnenschein, Eva; Gram, Lone

    2015-01-01

    Only about 1% of marine bacteria have been brought into culture using traditional techniques. The purpose of this study was to investigate if mimicking the natural bacterial environment can increase culturability.We used marine substrates containing defined algal polymers or gellan gum...... 100-fold; from 8.5 x 101 CFU/ml to 5.2 x 103 CFU/ml, whereas addition of AHLs did not improve culturability on any of the media.The substitution of agar with gellan gum shows great promise for increasing culturability of marine bacteria, and further studies are ongoing. The AHLs used in this study...... were selected based on a previous study determining the most common AHLs produced by marine strains of the Vibrionaceae family. However, their effect on culturability could not be fully explained, so also here further studies are being carried out....

  17. Physics of Intracellular Organization in Bacteria.

    Science.gov (United States)

    Wingreen, Ned S; Huang, Kerwyn Casey

    2015-01-01

    With the realization that bacteria achieve exquisite levels of spatiotemporal organization has come the challenge of discovering the underlying mechanisms. In this review, we describe three classes of such mechanisms, each of which has physical origins: the use of landmarks, the creation of higher-order structures that enable geometric sensing, and the emergence of length scales from systems of chemical reactions coupled to diffusion. We then examine the diversity of geometric cues that exist even in cells with relatively simple geometries, and end by discussing both new technologies that could drive further discovery and the implications of our current knowledge for the behavior, fitness, and evolution of bacteria. The organizational strategies described here are employed in a wide variety of systems and in species across all kingdoms of life; in many ways they provide a general blueprint for organizing the building blocks of life.

  18. Protein-Injection Machines in Bacteria.

    Science.gov (United States)

    Galán, Jorge E; Waksman, Gabriel

    2018-03-08

    Many bacteria have evolved specialized nanomachines with the remarkable ability to inject multiple bacterially encoded effector proteins into eukaryotic or prokaryotic cells. Known as type III, type IV, and type VI secretion systems, these machines play a central role in the pathogenic or symbiotic interactions between multiple bacteria and their eukaryotic hosts, or in the establishment of bacterial communities in a diversity of environments. Here we focus on recent progress elucidating the structure and assembly pathways of these machines. As many of the interactions shaped by these machines are of medical importance, they provide an opportunity to develop novel therapeutic approaches to combat important human diseases. Copyright © 2018 Elsevier Inc. All rights reserved.

  19. Have sex or not? Lessons from bacteria.

    Science.gov (United States)

    Lodé, T

    2012-01-01

    Sex is one of the greatest puzzles in evolutionary biology. A true meiotic process occurs only in eukaryotes, while in bacteria, gene transcription is fragmentary, so asexual reproduction in this case really means clonal reproduction. Sex could stem from a signal that leads to increased reproductive output of all interacting individuals and could be understood as a secondary consequence of primitive metabolic reactions. Meiotic sex evolved in proto-eukaryotes to solve a problem that bacteria did not have, namely a large amount of DNA material, occurring in an archaic step of proto-cell formation and genetic exchanges. Rather than providing selective advantages through reproduction, sex could be thought of as a series of separate events which combines step-by-step some very weak benefits of recombination, meiosis, gametogenesis and syngamy. Copyright © 2012 S. Karger AG, Basel.

  20. DNA Mismatch Repair in Eukaryotes and Bacteria

    Directory of Open Access Journals (Sweden)

    Kenji Fukui

    2010-01-01

    Full Text Available DNA mismatch repair (MMR corrects mismatched base pairs mainly caused by DNA replication errors. The fundamental mechanisms and proteins involved in the early reactions of MMR are highly conserved in almost all organisms ranging from bacteria to human. The significance of this repair system is also indicated by the fact that defects in MMR cause human hereditary nonpolyposis colon cancers as well as sporadic tumors. To date, 2 types of MMRs are known: the human type and Escherichia coli type. The basic features of the former system are expected to be universal among the vast majority of organisms including most bacteria. Here, I review the molecular mechanisms of eukaryotic and bacterial MMR, emphasizing on the similarities between them.

  1. Probiotic bacteria induce a 'glow of health'.

    Directory of Open Access Journals (Sweden)

    Tatiana Levkovich

    Full Text Available Radiant skin and hair are universally recognized as indications of good health. However, this 'glow of health' display remains poorly understood. We found that feeding of probiotic bacteria to aged mice induced integumentary changes mimicking peak health and reproductive fitness characteristic of much younger animals. Eating probiotic yogurt triggered epithelial follicular anagen-phase shift with sebocytogenesis resulting in thick lustrous fur due to a bacteria-triggered interleukin-10-dependent mechanism. Aged male animals eating probiotics exhibited increased subcuticular folliculogenesis, when compared with matched controls, yielding luxuriant fur only in probiotic-fed subjects. Female animals displayed probiotic-induced hyperacidity coinciding with shinier hair, a feature that also aligns with fertility in human females. Together these data provide insights into mammalian evolution and novel strategies for integumentary health.

  2. [RAPD analysis of plant pathogenic coryneform bacteria].

    Science.gov (United States)

    Yin, Yan-Ni; Chen, Yong-Fang; Li, Shi-Mo; Guo, Jian-Hua

    2005-12-01

    RAPD analysis was used for the taxonomy of plant pathogenic coryneform bacteria, especially for the classification of two new pathogens (Curtobacterium flaccumfaciens pv. basellae pv. nov. and Curtobacterium flaccumfaciens pv. beticola pv. nov.). 20 random primers were screened from 50 ones to detect polymorphism among the total strains used. 80.4% were polymorphic bands among the 225 ones produced. The results of pairwise similarity and UPGMA cluster analysis suggest that the two new pathovars of sugar beet (Beta vulgaris var. saccharifera) and malabar spinach (Basella rubra) are genetically close related with Curtobacterium flacumfaciens, and the minimal similarity coefficient is 0.6511. According to the RAPD analysis and previous research, some newly made taxonomic changes of the plant pathogenic coryneform bacteria are discussed.

  3. Biotechnological potential of Clostridium butyricum bacteria

    Directory of Open Access Journals (Sweden)

    Daria Szymanowska-Powałowska

    2014-09-01

    Full Text Available In response to demand from industry for microorganisms with auspicious biotechnological potential, a worldwide interest has developed in bacteria and fungi isolation. Microorganisms of interesting metabolic properties include non-pathogenic bacteria of the genus Clostridium, particularly C. acetobutylicum, C. butyricum and C. pasteurianum. A well-known property of C. butyricum is their ability to produce butyric acid, as well as effectively convert glycerol to 1,3-propanediol (38.2 g/L. A conversion rate of 0.66 mol 1,3-propanediol/mol of glycerol has been obtained. Results of the studies described in the present paper broaden our knowledge of characteristic features of C. butyricum specific isolates in terms of their phylogenetic affiliation, fermentation capacity and antibacterial properties.

  4. Alkaliphilic bacteria: applications in industrial biotechnology.

    Science.gov (United States)

    Sarethy, Indira P; Saxena, Yashi; Kapoor, Aditi; Sharma, Manisha; Sharma, Sanjeev K; Gupta, Vandana; Gupta, Sanjay

    2011-07-01

    Alkaliphiles are interesting groups of extremophilic organisms that thrive at pH of 9.0 and above. Many of their products, in particular enzymes, have found widespread applications in industry, primarily in the detergent and laundry industries. While the enzymes have been a runaway success from the industrial point of view, many more products have been reported from alkaliphiles such as antibiotics and carotenoids. Less known are their potential for degradation of xenobiotics. They also play a key role in biogeocycling of important inorganic compounds. This review provides an insight into the huge diversity of alkaliphilic bacteria, the varied products obtained from them, and the need for further investigations on these interesting bacteria.

  5. High efficiency recombineering in lactic acid bacteria

    OpenAIRE

    van Pijkeren, Jan-Peter; Britton, Robert A.

    2012-01-01

    The ability to efficiently generate targeted point mutations in the chromosome without the need for antibiotics, or other means of selection, is a powerful strategy for genome engineering. Although oligonucleotide-mediated recombineering (ssDNA recombineering) has been utilized in Escherichia coli for over a decade, the successful adaptation of ssDNA recombineering to Gram-positive bacteria has not been reported. Here we describe the development and application of ssDNA recombineering in lact...

  6. Antibiotic resistance of lactic acid bacteria

    OpenAIRE

    Bulajić Snežana; Mijačević Zora; Savić-Radovanović Radoslava

    2008-01-01

    Knowledge on the antibiotic resistance of lactic acid bacteria is still limited, possibly because of the large numbers of genera and species encountered in this group, as well as variances in their resistance spectra. The EFSA considers antibiotic resistances, especially transferable resistances, an important decision criterion for determining a strain's QPS status. There are no approved standards for the phenotypic or genotypic evaluation of antibiotic resistances in food isolat...

  7. Genetics of proteinases of lactic acid bacteria

    OpenAIRE

    Kok, Jan; Venema, Gerhardus

    1988-01-01

    Because it is essential for good growth with concomitant rapid acid production, and for the production of flavorous peptides and amino acids, the proteolytic ability of lactic acid bacteria is of crucial importance for reliable dairy product quality. In view of this importance, considerable research has been carried out to characterize the enzymes involved. The intensified genetic research in the lactic acid streptococci and the development of gene cloning systems for these organisms have res...

  8. Stress Physiology of Lactic Acid Bacteria

    OpenAIRE

    Papadimitriou, Konstantinos; Alegría, Ángel; Bron, Peter A.; de Angelis, Maria; Gobbetti, Marco; Kleerebezem, Michiel; Lemos, José A.; Linares, Daniel M.; Ross, Paul; Stanton, Catherine; Turroni, Francesca; van Sinderen, Douwe; Varmanen, Pekka; Ventura, Marco; Zúñiga, Manuel

    2016-01-01

    Lactic acid bacteria (LAB) are important starter, commensal, or pathogenic microorganisms. The stress physiology of LAB has been studied in depth for over 2 decades, fueled mostly by the technological implications of LAB robustness in the food industry. Survival of probiotic LAB in the host and the potential relatedness of LAB virulence to their stress resilience have intensified interest in the field. Thus, a wealth of information concerning stress responses exists today for strains as diver...

  9. Engineering bacteria for enhanced polyhydroxyalkanoates (PHA) biosynthesis

    OpenAIRE

    Chen, Guo-Qiang; Jiang, Xiao-Ran

    2017-01-01

    Polyhydroxyalkanoates (PHA) have been produced by some bacteria as bioplastics for many years. Yet their commercialization is still on the way. A few issues are related to the difficulty of PHA commercialization: namely, high cost and instabilities on molecular weights (Mw) and structures, thus instability on thermo-mechanical properties. The high cost is the result of complicated bioprocessing associated with sterilization, low conversion of carbon substrates to PHA products, and slow growth...

  10. Biological Potential of Chitinolytic Marine Bacteria

    OpenAIRE

    Sara Skøtt Paulsen; Birgitte Andersen; Lone Gram; Henrique Machado

    2016-01-01

    Chitinolytic microorganisms secrete a range of chitin modifying enzymes, which can be exploited for production of chitin derived products or as fungal or pest control agents. Here, we explored the potential of 11 marine bacteria (Pseudoalteromonadaceae, Vibrionaceae) for chitin degradation using in silico and phenotypic assays. Of 10 chitinolytic strains, three strains, Photobacterium galatheae S2753, Pseudoalteromonas piscicida S2040 and S2724, produced large clearing zones on chitin plates....

  11. Method of detecting and counting bacteria

    Science.gov (United States)

    Picciolo, G. L.; Chappelle, E. W. (Inventor)

    1976-01-01

    An improved method is provided for determining bacterial levels, especially in samples of aqueous physiological fluids. The method depends on the quantitative determination of bacterial adenosine triphosphate (ATP) in the presence of nonbacterial ATP. The bacterial ATP is released by cell rupture and is measured by an enzymatic bioluminescent assay. A concentration technique is included to make the method more sensitive. It is particularly useful where the fluid to be measured contains an unknown or low bacteria count.

  12. Extremophile bacteria glycolipids: structure and biological activity

    OpenAIRE

    Carillo, Sara

    2013-01-01

    Extremophile bacteria are able to survive in harsh life conditions, such as high or low temperatures (thermophiles and psychrophiles, respectively), high pressure (barophiles), high or low pH values (acidophiles or alkalophiles), environments characterized by high salt concentrations (halophiles). Structural features of the macromolecules belonging to the external layer are fundamental in adaptation mechanisms, e.g. it is well known that halophiles membrane phospholipids showed an increase...

  13. Chemotactic waves of bacteria at the mesoscale

    OpenAIRE

    Calvez, Vincent

    2016-01-01

    The existence of travelling waves for a model of concentration waves of bacteria is investigated. The model consists in a kinetic equation for the biased motion of cells following a run-and-tumble process, coupled with two reaction-diffusion equations for the chemical signals. Strong mathematical difficulties arise in comparison with the diffusive regime which was studied in a previous work. The cornerstone of the proof consists in establishing monotonicity properties of the spatial density o...

  14. Macrophage defense mechanisms against intracellular bacteria.

    Science.gov (United States)

    Weiss, Günter; Schaible, Ulrich E

    2015-03-01

    Macrophages and neutrophils play a decisive role in host responses to intracellular bacteria including the agent of tuberculosis (TB), Mycobacterium tuberculosis as they represent the forefront of innate immune defense against bacterial invaders. At the same time, these phagocytes are also primary targets of intracellular bacteria to be abused as host cells. Their efficacy to contain and eliminate intracellular M. tuberculosis decides whether a patient initially becomes infected or not. However, when the infection becomes chronic or even latent (as in the case of TB) despite development of specific immune activation, phagocytes have also important effector functions. Macrophages have evolved a myriad of defense strategies to combat infection with intracellular bacteria such as M. tuberculosis. These include induction of toxic anti-microbial effectors such as nitric oxide and reactive oxygen intermediates, the stimulation of microbe intoxication mechanisms via acidification or metal accumulation in the phagolysosome, the restriction of the microbe's access to essential nutrients such as iron, fatty acids, or amino acids, the production of anti-microbial peptides and cytokines, along with induction of autophagy and efferocytosis to eliminate the pathogen. On the other hand, M. tuberculosis, as a prime example of a well-adapted facultative intracellular bacterium, has learned during evolution to counter-balance the host's immune defense strategies to secure survival or multiplication within this otherwise hostile environment. This review provides an overview of innate immune defense of macrophages directed against intracellular bacteria with a focus on M. tuberculosis. Gaining more insights and knowledge into this complex network of host-pathogen interaction will identify novel target sites of intervention to successfully clear infection at a time of rapidly emerging multi-resistance of M. tuberculosis against conventional antibiotics. © 2015 The Authors

  15. Macrophage defense mechanisms against intracellular bacteria

    Science.gov (United States)

    Weiss, Günter; Schaible, Ulrich E

    2015-01-01

    Macrophages and neutrophils play a decisive role in host responses to intracellular bacteria including the agent of tuberculosis (TB), Mycobacterium tuberculosis as they represent the forefront of innate immune defense against bacterial invaders. At the same time, these phagocytes are also primary targets of intracellular bacteria to be abused as host cells. Their efficacy to contain and eliminate intracellular M. tuberculosis decides whether a patient initially becomes infected or not. However, when the infection becomes chronic or even latent (as in the case of TB) despite development of specific immune activation, phagocytes have also important effector functions. Macrophages have evolved a myriad of defense strategies to combat infection with intracellular bacteria such as M. tuberculosis. These include induction of toxic anti-microbial effectors such as nitric oxide and reactive oxygen intermediates, the stimulation of microbe intoxication mechanisms via acidification or metal accumulation in the phagolysosome, the restriction of the microbe's access to essential nutrients such as iron, fatty acids, or amino acids, the production of anti-microbial peptides and cytokines, along with induction of autophagy and efferocytosis to eliminate the pathogen. On the other hand, M. tuberculosis, as a prime example of a well-adapted facultative intracellular bacterium, has learned during evolution to counter-balance the host's immune defense strategies to secure survival or multiplication within this otherwise hostile environment. This review provides an overview of innate immune defense of macrophages directed against intracellular bacteria with a focus on M. tuberculosis. Gaining more insights and knowledge into this complex network of host-pathogen interaction will identify novel target sites of intervention to successfully clear infection at a time of rapidly emerging multi-resistance of M. tuberculosis against conventional antibiotics. PMID:25703560

  16. Tumour targeting with systemically administered bacteria.

    LENUS (Irish Health Repository)

    Morrissey, David

    2012-01-31

    Challenges for oncology practitioners and researchers include specific treatment and detection of tumours. The ideal anti-cancer therapy would selectively eradicate tumour cells, whilst minimising side effects to normal tissue. Bacteria have emerged as biological gene vectors with natural tumour specificity, capable of homing to tumours and replicating locally to high levels when systemically administered. This property enables targeting of both the primary tumour and secondary metastases. In the case of invasive pathogenic species, this targeting strategy can be used to deliver genes intracellularly for tumour cell expression, while non-invasive species transformed with plasmids suitable for bacterial expression of heterologous genes can secrete therapeutic proteins locally within the tumour environment (cell therapy approach). Many bacterial genera have been demonstrated to localise to and replicate to high levels within tumour tissue when intravenously (IV) administered in rodent models and reporter gene tagging of bacteria has permitted real-time visualisation of this phenomenon. Live imaging of tumour colonising bacteria also presents diagnostic potential for this approach. The nature of tumour selective bacterial colonisation appears to be tumour origin- and bacterial species- independent. While originally a correlation was drawn between anaerobic bacterial colonisation and the hypoxic nature of solid tumours, it is recently becoming apparent that other elements of the unique microenvironment within solid tumours, including aberrant neovasculature and local immune suppression, may be responsible. Here, we consider the pre-clinical data supporting the use of bacteria as a tumour-targeting tool, recent advances in the area, and future work required to develop it into a beneficial clinical tool.

  17. Streptomyces Bacteria as Potential Probiotics in Aquaculture

    OpenAIRE

    Tan, Loh Teng-Hern; Chan, Kok-Gan; Lee, Learn-Han; Goh, Bey-Hing

    2016-01-01

    In response to the increased seafood demand from the ever-going human population, aquaculture has become the fastest growing animal food-producing sector. However, the indiscriminate use of antibiotics as a biological control agents for fish pathogens has led to the emergence of antibiotic resistance bacteria. Probiotics are defined as living microbial supplement that exert beneficial effects on hosts as well as improvement of environmental parameters. Probiotics have been proven to be effect...

  18. [Application of anaerobic bacteria detection in oral and maxillofacial infection].

    Science.gov (United States)

    Bao, Zhen-ying; Lin, Qin; Meng, Yan-hong; He, Chun; Su, Jia-zeng; Peng, Xin

    2016-02-18

    To investigate the distribution and drug resistance of anaerobic bacteria in the patients with oral and maxillofacial infection. Aerobic and anaerobic bacteria cultures from 61 specimens of pus from the patients with oral and maxillofacial infection in the Department of Oral and Maxillofacial Surgery, Peking University School of Stomatology were identified. The culture type was evaluated by API 20A kit and drug resistance test was performed by Etest method. The clinical data and antibacterial agents for the treatment of the 61 cases were collected, and the final outcomes were recorded. The bacteria cultures were isolated from all the specimens, with aerobic bacteria only in 6 cases (9.8%), anaerobic bacteria only in 7 cases (11.5%), and both aerobic and anaerobic bacteria in 48 cases (78.7%). There were 55 infected cases (90.2%) with anaerobic bacteria, and 81 anaerobic bacteria stains were isolated. The highest bacteria isolation rate of Gram positive anaerobic bacteria could be found in Peptostreptococcus, Bifidobacterium and Pemphigus propionibacterium. No cefoxitin, amoxicillin/carat acid resistant strain was detected in the above three Gram positive anaerobic bacteria. The highest bacteria isolation rate of Gram negative anaerobic bacteria could be detected in Porphyromonas and Prevotella. No metronidazole, cefoxitin, amoxicillin/carat acid resistant strain was found in the two Gram negative anaerobic bacteria. In the study, 48 patients with oral and maxillofacial infection were treated according to the results of drug resistance testing, and the clinical cure rate was 81.3%. Mixed aerobic and anaerobic bacteria cultures are very common in most oral and maxillofacial infection patients. Anaerobic bacteria culture and drug resistance testing play an important role in clinical treatment.

  19. 3D printing of bacteria into functional complex materials

    OpenAIRE

    Schaffner, Manuel; Rühs, Patrick A.; Coulter, Fergal; Kilcher, Samuel; Studart, André R.

    2017-01-01

    Despite recent advances to control the spatial composition and dynamic functionalities of bacteria embedded in materials, bacterial localization into complex three-dimensional (3D) geometries remains a major challenge. We demonstrate a 3D printing approach to create bacteria-derived functional materials by combining the natural diverse metabolism of bacteria with the shape design freedom of additive manufacturing. To achieve this, we embedded bacteria in a biocompatible and functionalized 3D ...

  20. Bacteria as transporters of phosphorus through soil

    DEFF Research Database (Denmark)

    Glæsner, N.; Bælum, Jacob; Jacobsen, C. S.

    2016-01-01

    The transport of phosphorus (P) from agricultural land has led to the eutrophication of surface waters worldwide, especially in areas with intensive animal production. In this research, we investigated the role of bacteria in the leaching of P through three agricultural soils with different......RNA genes cell−1. Leaching of bacteria was in the range of 2.5–4.5 × 105 cells ml−1 prior to application of slurry to the three soil textures. After slurry application, leaching increased to 1.1 × 106 cells ml−1 in the loamy sand, 4.9 × 106 cells ml−1 in the sandy loam and 5.0 × 106 cells ml−1 in the loam....... Based on the reported P content of soil bacteria, 0.3–1.8% of the total P leached was present in the bacterial biomass when no slurry was applied, whereas slurry application increased the leaching of P from the bacterial biomass to 3−7.9% of total P leached. Bacterial leaching was related...

  1. Transfer of DNA from Bacteria to Eukaryotes

    Directory of Open Access Journals (Sweden)

    Benoît Lacroix

    2016-07-01

    Full Text Available Historically, the members of the Agrobacterium genus have been considered the only bacterial species naturally able to transfer and integrate DNA into the genomes of their eukaryotic hosts. Yet, increasing evidence suggests that this ability to genetically transform eukaryotic host cells might be more widespread in the bacterial world. Indeed, analyses of accumulating genomic data reveal cases of horizontal gene transfer from bacteria to eukaryotes and suggest that it represents a significant force in adaptive evolution of eukaryotic species. Specifically, recent reports indicate that bacteria other than Agrobacterium, such as Bartonella henselae (a zoonotic pathogen, Rhizobium etli (a plant-symbiotic bacterium related to Agrobacterium, or even Escherichia coli, have the ability to genetically transform their host cells under laboratory conditions. This DNA transfer relies on type IV secretion systems (T4SSs, the molecular machines that transport macromolecules during conjugative plasmid transfer and also during transport of proteins and/or DNA to the eukaryotic recipient cells. In this review article, we explore the extent of possible transfer of genetic information from bacteria to eukaryotic cells as well as the evolutionary implications and potential applications of this transfer.

  2. Engineering bacteria for enhanced polyhydroxyalkanoates (PHA biosynthesis

    Directory of Open Access Journals (Sweden)

    Guo-Qiang Chen

    2017-09-01

    Full Text Available Polyhydroxyalkanoates (PHA have been produced by some bacteria as bioplastics for many years. Yet their commercialization is still on the way. A few issues are related to the difficulty of PHA commercialization: namely, high cost and instabilities on molecular weights (Mw and structures, thus instability on thermo-mechanical properties. The high cost is the result of complicated bioprocessing associated with sterilization, low conversion of carbon substrates to PHA products, and slow growth of microorganisms as well as difficulty of downstream separation. Future engineering on PHA producing microorganisms should be focused on contamination resistant bacteria especially extremophiles, developments of engineering approaches for the extremophiles, increase on carbon substrates to PHA conversion and controlling Mw of PHA. The concept proof studies could still be conducted on E. coli or Pseudomonas spp. that are easily used for molecular manipulations. In this review, we will use E. coli and halophiles as examples to show how to engineer bacteria for enhanced PHA biosynthesis and for increasing PHA competitiveness.

  3. Engineering bacteria for enhanced polyhydroxyalkanoates (PHA) biosynthesis.

    Science.gov (United States)

    Chen, Guo-Qiang; Jiang, Xiao-Ran

    2017-09-01

    Polyhydroxyalkanoates (PHA) have been produced by some bacteria as bioplastics for many years. Yet their commercialization is still on the way. A few issues are related to the difficulty of PHA commercialization: namely, high cost and instabilities on molecular weights (Mw) and structures, thus instability on thermo-mechanical properties. The high cost is the result of complicated bioprocessing associated with sterilization, low conversion of carbon substrates to PHA products, and slow growth of microorganisms as well as difficulty of downstream separation. Future engineering on PHA producing microorganisms should be focused on contamination resistant bacteria especially extremophiles, developments of engineering approaches for the extremophiles, increase on carbon substrates to PHA conversion and controlling Mw of PHA. The concept proof studies could still be conducted on E. coli or Pseudomonas spp. that are easily used for molecular manipulations. In this review, we will use E. coli and halophiles as examples to show how to engineer bacteria for enhanced PHA biosynthesis and for increasing PHA competitiveness.

  4. Genera and species in acetic acid bacteria.

    Science.gov (United States)

    Yamada, Yuzo; Yukphan, Pattaraporn

    2008-06-30

    Taxonomic studies of acetic acid bacteria were historically surveyed. The genus Acetobacter was first introduced in 1898 with a single species, Acetobacter aceti. The genus Gluconobacter was proposed in 1935 for strains with intense oxidation of glucose to gluconic acid rather than oxidation of ethanol to acetic acid and no oxidation of acetate. The genus "Acetomonas" was described in 1954 for strains with polar flagellation and no oxidation of acetate. The proposals of the two generic names were due to confusion, and "Acetomonas" was a junior subjective synonym of Gluconobacter. The genus Acetobacter was in 1984 divided into two subgenera, Acetobacter and Gluconoacetobacter. The latter was elevated to the genus Gluconacetobacter in 1998. In the acetic acid bacteria, ten genera are presently recognized and accommodated to the family Acetobacteraceae, the Alphaproteobacteria: Acetobacteer, Gluconobacter, Acidomonas, Gluconacetobacter, Asaia, Kozakia, Swaminathania, Saccharibacter, Neoasaia and Granulibacter. In contrast, the genus Frateuria, strains of which were once named 'pseudacetic acid bacteria', was classified into the Gammaproteobacteria. The genus Gluconacetobacter was phylogenetically divided into two groups: the Gluconacetobacter liquefaciens group and the Gluconacetobacter xylinus group. The two groups were discussed taxonomically.

  5. Intracellular bacteria: the origin of dinoflagellate toxicity.

    Science.gov (United States)

    Silva, E S

    1990-01-01

    Dinoflagellate blooms of the same species have been registered either as toxic or nontoxic and, in the latter case, toxicity may be of different types. A hypothesis has been formulated according to which the bacteria having in some way taken part in the toxin formation are either inside the dinoflagellate cell or in the nutritive liquid. The presence of intracellular bacteria in those microorganisms has been studied mainly in material from cultures, a few from the sea, and several strains were isolated from different species. Experiments with crossed inoculations have shown that the bacterial strain from Gonyaulax tamarensis caused the cells of some other species to become toxic. From nontoxic clonal cultures of Prorocentrum balticum, Glenodinium foliaceum, and Gyrodinium instriatum, after inoculation of that bacterial strain, cultures were obtained whose cell extracts showed the same kind of toxicity as G. tamarensis. No toxic action could be found in the extracts of the bacterial cells form the assayed strains. The interference of intracellular bacteria in the metabolism of dinoflagellates must be the main cause of their toxicity.

  6. Soil bacteria for remediation of polluted soils

    Energy Technology Data Exchange (ETDEWEB)

    Springael, D.; Bastiaens, L.; Carpels, M.; Mergaey, M.; Diels, L.

    1996-09-18

    Soil bacteria, specifically adapted to contaminated soils, may be used for the remediation of polluted soils. The Flemish research institute VITO has established a collection of bacteria, which were isolated from contaminated areas. This collection includes microbacteria degrading mineral oils (Pseudomonas sp., Acinetobacter sp. and others), microbacteria degrading polycyclic aromatic hydrocarbons (genera Sphingomonas and Mycobacterium), microbacteria degrading polychlorobiphenyls (genus Ralstonia and strains related to beta-Proteobacteria), and metal resistant bacteria with plasmid borne resistances to Cd, Zn, Ni, Co, Cu, Hg, and Cr. Bench-scale reactors were developed to investigate the industrial feasibility of bioremediation. Batch Stirred Tank Reactors were used to evaluate the efficiency of oil degraders. Soils, contaminated with non-ferrous metals, were treated using a Bacterial Metal Slurry Reactor. It was found that the reduction of the Cd concentration may vary strongly from sample to sample: reduction factors vary from 95 to 50%. Is was shown that Cd contained in metallic sinter and biologically unavailable Cd could not be removed.

  7. Fecal indicator bacteria at Havana Bay

    International Nuclear Information System (INIS)

    Lopez Perez, Lisse; Gomez D'Angelo, Yamiris; Beltran Gonzalez, Jesus; Alvarez Valiente, Reinaldo

    2013-01-01

    Aims: Fecal indicator bacteria concentrations were evaluated in Havana Bay. Methods: Concentrations of traditional fecal indicator bacteria were calculated between April 2010 and February 2011, by MPN methods. Concentrations of thermo tolerant coliform (CTT), Escherichia coli, fecal streptococci (EF), intestinal enterococci (ENT) in seawater, and Clostridium perfringens in sediment surface, were determined. Results: CTT and E. coli levels were far above Cuban water quality standard for indirect contact with water, showing the negative influence of sewage and rivers on the bay. The EF and ENT were measured during sewage spills at the discharge site and they were suitable indicators of fecal contamination, but these indicators didn't show the same behavior in other selected sites. This result comes from its well-known inactivation by solar light in tropical zones and the presumable presence of humid acids in the waters of the bay. Conclusion: Fecal indicator bacteria and its statistical relationships reflect recent and chronic fecal contamination at the bay and near shores.

  8. [Prevent bacteria from communicating: Divide and cure].

    Science.gov (United States)

    Mion, S; Rémy, B; Plener, L; Chabrière, E; Daudé, D

    2018-03-26

    Quorum Sensing (QS) is a communication system used by numerous bacteria to synchronize their behavior according to the cell density. In this way, bacteria secrete and sense small mediating molecules, called autoinducers (AI), which concentration increases in the environment proportionally to bacterial cell number. QS induces major physiological and phenotypic changes such as virulence induction and biofilm formation. Biofilm represents a physical barrier which shelters bacteria poorly sensitive to antimicrobial treatments and favors the apparition of resistance mechanisms. Disturbing QS is referred to as quorum quenching (QQ). This strategy is used by microorganisms themselves to prevent the development of specific group behaviors. Two strategies are mainly employed: the use of quorum sensing inhibitors (QSI) and of quorum quenching enzymes (QQE) that degrades AI. Many studies have been dedicated to identifying QSI (natural or synthetic) as well as QQE and demonstrating their anti-virulence and anti-biofilm effects on numerous bacterial species. Synergistic effects between QQ and traditional treatments such as antibiotherapy or with reemerging phage therapy have been put forward. The efficiency of numerous QSI and QQE was thereby demonstrated either with in vitro or in vivo animal models leading to the development of medical devices containing QSI and QQE to improve already existing treatments. Copyright © 2018 Académie Nationale de Pharmacie. Published by Elsevier Masson SAS. All rights reserved.

  9. Acoustic manipulation of bacteria cells suspensions

    Science.gov (United States)

    GutiéRrez-Ramos, Salomé; Hoyos, Mauricio; Aider, Jean Luc; Ruiz, Carlos; Acoustofluidics team Team; Soft; Bio group Collaboration

    An acoustic contacless manipulation gives advantages in the exploration of the complex dynamics enviroment that active matter exhibits. Our works reports the control confinement and dispersion of Escherichia coliRP437-pZA3R-YFP suspensions (M9Glu-Ca) via acoustic levitation.The manipulation of the bacteria bath in a parallel plate resonator is achieved using the acoustic radiation force and the secondary radiation force. The primary radiation force generates levitation of the bacteria cells at the nodal plane of the ultrasonic standing wave generated inside the resonator. On the other side, secondary forces leads to the consolidation of stable aggregates. All the experiments were performed in the acoustic trap described, where we excite the emission plate with a continuous sinusoidal signal at a frequency in the order of MHz and a quartz slide as the reflector plate. In a typical experiment we observed that, before the input of the signal, the bacteria cells exhibit their typical run and tumble behavior and after the sound is turned on all of them displace towards the nodal plane, and instantaneously the aggregation begins in this region. CNRS French National Space Studies, CONACYT Mexico.

  10. Isolation and characterization of feather degrading bacteria from ...

    African Journals Online (AJOL)

    This study is aimed at isolating and characterizing new culturable feather degrading bacteria from soils of the University of Mauritius Farm. Bacteria that were isolated were tested for their capability to grow on feather meal agar (FMA). Proteolytic bacteria were tested for feather degradation and were further identified ...

  11. Bacteria associated with contamination of ready-to-eat (RTE ...

    African Journals Online (AJOL)

    The bacteria associated with contamination of ready-to-eat (RTE) cooked rice in Lagos, Nigeria were studied using standard microbiological methods. The objective of this study was to investigate the distribution of pathogenic bacteria recovered from RTE cooked rice in Lagos, assess bacteria load in the contaminated RTE ...

  12. Metabolism in bacteria at low temperature: A recent report

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... The adaptability of bacteria to extreme cold environments has been demonstrated from time to time by various investigators. Metabolic activity of bacteria at subzero temperatures is also evidenced. Recent studies indicate that bacteria continue both catabolic and anabolic activities at subzero temperatures.

  13. Bacteria associated with cultures of psathyrella atroumbonata (Pleger)

    African Journals Online (AJOL)

    These bacteria include Bacillus licheniformis, Bacillus subtilis, Leuconostoc mesenteroides, Pseudomonas aeruginosa, Bacillus cereus and Staphylococcus aureus. The average bacteria count was 1.0 x 106 cfu/ml and these bacteria grew within pH range of 5.0 and 9.0. the optimum temperature range of growth lied ...

  14. The growth of bacteria on organic compounds in drinking water

    NARCIS (Netherlands)

    Kooij, van der D.

    1984-01-01

    Growth ("regrowth") of bacteria In drinking water distribution systems results in a deterioration of the water quality. Regrowth of chemoheterotrophic bacteria depends on the presence of organic. compounds that serve as a nutrient source for these bacteria. A batch-culture technique was

  15. Quantification and Qualification of Bacteria Trapped in Chewed Gum

    NARCIS (Netherlands)

    Wessel, Stefan W.; van der Mei, Henny C.; Morando, David; Slomp, Anje M.; van de Belt-Gritter, Betsy; Maitra, Amarnath; Busscher, Henk J.

    2015-01-01

    Chewing of gum contributes to the maintenance of oral health. Many oral diseases, including caries and periodontal disease, are caused by bacteria. However, it is unknown whether chewing of gum can remove bacteria from the oral cavity. Here, we hypothesize that chewing of gum can trap bacteria and

  16. Bacteria Associated with Fresh Tilapia Fish (Oreochromis niloticus ...

    African Journals Online (AJOL)

    acer

    The isolates were found to be of medical importance. Keywords: Bacteria, Tilapia fish ... target,Systemic bacterial disease: bacteria inwades the fish's body and ... Shinkafi & Ukwaja; Bacteria Associated with Fresh Tilapia Fish (Oreochromis niloticus) Sold At Sokoto Central Market in Sokoto, Nigeria. 218 more prone to raid ...

  17. Mucolytic bacteria with increased prevalence in IBD mucosa augment in vitro utilization of mucin by other bacteria

    NARCIS (Netherlands)

    Png, C.W.; Linden, S.K.; Gilshenan, K.S.; Zoetendal, E.G.; McSweeney, C.S.; Sly, L.I.; McGuckin, M.A.; Florin, T.H.

    2010-01-01

    OBJECTIVES: Mucosa-associated bacteria are increased in inflammatory bowel disease (IBD), which suggests the possibility of an increased source of digestible endogenous mucus substrate. We hypothesized that mucolytic bacteria are increased in IBD, providing increased substrate to sustain

  18. Bacteria-Targeting Nanoparticles for Managing Infections

    Science.gov (United States)

    Radovic-Moreno, Aleksandar Filip

    Bacterial infections continue to be a significant concern particularly in healthcare settings and in the developing world. Current challenges include the increasing spread of drug resistant (DR) organisms, the side effects of antibiotic therapy, the negative consequences of clearing the commensal bacterial flora, and difficulties in developing prophylactic vaccines. This thesis was an investigation of the potential of a class of polymeric nanoparticles (NP) to contribute to the management of bacterial infections. More specifically, steps were taken towards using these NPs (1) to achieve greater spatiotemporal control over drug therapy by more targeted antibiotic delivery to bacteria, and (2) to develop a prophylactic vaccine formulation against the common bacterial sexually transmitted disease (STD) caused by Chlamydia trachomatis. In the first part, we synthesized polymeric NPs containing poly(lactic-co-glycolic acid)-block-poly(L-histidine)-block-poly(ethylene glycol) (PLGA-PLH-PEG). We show that these NPs are able to bind to bacteria under model acidic infection conditions and are able to encapsulate and deliver vancomycin to inhibit the growth of Staphylococcus aureus bacteria in vitro. Further work showed that the PLGA-PLH-PEG-based NPs demonstrated the potential for competition for binding bacteria at a site of infection from soluble protein and model phagocytic and tissue-resident cells in a NP composition dependent manner. The NPs demonstrated low toxicity in vitro, were well tolerated by mice in vivo, and circulated in the blood on timescales comparable to control PLGA-PEG NPs. In the second part, we used PLGA-PLH-PEG-based NPs to design a prophylactic vaccine against the obligate intracellular bacterium Chlamydia trachomatis, the most common cause of bacterial STD in the world. Currently, no vaccines against this pathogen are approved for use in humans. We first formulated NPs encapsulating the TLR7 agonist R848 conjugated to poly(lactic acid) (R848-PLA

  19. Resistência à mupirocina entre isolados de Staphylococcus aureus de profissionais de enfermagem Resistencia al mupirocin en cepas aisladas de Staphylococcus aureus de profesionales de enfermería Mupirocin-resistant Staphylococcus aureus in samples belonging to professional nurses

    Directory of Open Access Journals (Sweden)

    Josely Pinto de Moura

    2010-06-01

    Full Text Available OBJETIVOS: Avaliar a colonização por Staphylococcus aureus sensíveis e resistentes à meticilina na saliva de profissionais de enfermagem e o perfil de resistência à mupirocina. MÉTODOS: Foram coletadas três amostras da saliva de 356 (94,2% profissionais participantes da pesquisa, totalizando 1.068 amostras processadas. Todos os aspectos éticos foram contemplados. A análise microbiológica compreendeu a identificação fenotípica, segundo normas do Clinical and Laboratory Standards Institute. RESULTADOS: Foram obtidos 73 indivíduos colonizados por Staphylococcus aureus na primeira coleta, 48 na segunda e 37 na terceira, somando 158 isolados de Staphylococcus aureus. Desses, 24 (15,2% eram resistentes à oxacilina e 30 resistentes à mupirocina (18,9%. A resistência à mupirocina foi observada de forma pronunciada nos Staphylococcus aureus metacilina resistente (MRSA; dos 24 MRSA, 17 (70,8% apresentaram-se resistentes a este antimicrobiano. CONCLUSÃO: Os resultados indicaram que a resistência à mupirocina é um importante problema, pois esse antibiótico é um excelente aliado nas medidas de controle das infecções de serviços de saúde.OBJETIVOS: Evaluar la colonización por Staphylococcus aureus sensibles y resistentes al meticilín en la saliva de profesionales de enfermería y, reconocer el perfil de resistencia a la mupirocina. MÉTODOS: Fueron recolectadas tres muestras de saliva de 356 (94,2% profesionales participantes de la investigación, totalizando 1.068 muestras procesadas. Todos los aspectos éticos fueron contemplados. El análisis microbiológico comprendió la identificación fenotípica, según normas del Clinical and Laboratory Standards Institute. RESULTADOS: Fueron obtenidos 73 individuos colonizados por Staphylococcus aureus en la primera recolección, 48 en la segunda y 37 en la tercera, sumando 158 muestras aisladas de Staphylococcus aureus. De esas, 24 (15,2% eran resistentes a la oxacilina y 30

  20. Protocolo POG 9061 en la recaída aislada a sistema nervioso central en pacientes con diagnóstico de leucemia linfoide aguda. Resultados de una serie de casos en el Hospital Universitario de Santander POG 9061 protocol to treat isolated central nervous system recurrence in patients with acute lymphoid leukemia at Hospital Universitario de Santander

    Directory of Open Access Journals (Sweden)

    Ernesto Rueda

    2010-04-01

    Full Text Available Introducción: La leucemia linfoide aguda (LLA es la neoplasia más común en niños; el 5-10 % presentan recaídas a sistema nervioso central (SNC, un factor de mal pronóstico. Objetivo: Describir los resultados obtenidos en una unidad de oncología pediátrica con el protocolo POG 9061 modificado, en pacientes con LLA y recaída aislada a SNC. Metodología: Cohorte de los pacientes atendidos en el Hospital Universitario de Santander (HUS. Se estimó la sobrevida libre de evento (SLE y la sobrevida total (ST, así como las alteraciones resultantes del protocolo. Se incluyeron 15 pacientes atendidos entre enero/93 y marzo/07; el último diagnóstico de recaída al SNC se hizo en noviembre/04. Resultados: El 66,6 % de las recaídas se dieron antes de 18 meses luego de remitir la LLA. Dos pacientes abandonaron el protocolo, uno de los cuales falleció; dos o más fallecieron luego de terminar el protocolo. La ST a cinco años fue de 85,6 % (IC95 % 53,3-96,2, mientras que la SLE de 84,9 % (IC95 % 51,2-96,0 %. La complicación más frecuente fue mielosupresión; no hubo alteraciones de la función renal y solo una ligera elevación de las pruebas de función hepática. Las causas de hospitalización fueron principalmente infecciones. El coeficiente intelectual de los pacientes posterior a la aplicación del protocolo indicaba deficiencia leve en el 45,4 % de ellos. Conclusiones: La sobrevida, el tipo y la frecuencia de complicaciones, son similares a las encontradas a nivel mundial, lo que es relevante dada la alta proporción de pacientes con recaída precoz luego de remisión de la LLA. Salud UIS 2010; 42: 7-17Introduction: Acute lymphoblastic leukemia (ALL is the most frequent neoplasm in children. Relapses to central nervous system (CNS Appears in 5-10 % of the ALL patients and is a bad prognostic factor. Objective: To describe the results obtained with modified POG 9061 protocol in a pediatric oncology unit. Methodology: Survival analysis was

  1. Antifungal Activity of Selected Lactic Acid Bacteria and Propionic Acid Bacteria against Dairy-Associated Spoilage Fungi

    DEFF Research Database (Denmark)

    Aunsbjerg, Stina Dissing

    Bacterial cultures of lactic and propionic acid bacteria are widely used in fermented products including dairy products. Spoilage fungi may constitute a quality and safety issue in these products. The antifungal properties of some lactic and propionic acid bacteria make them potential candidates...... diacetyl and lactic acid, 6 antifungal hydroxy acids were identified. Of these, 3 have previously been reported from antifungal lactic acid bacteria, whereas the other 3 hydroxy acids have not previously been reported produced by antifungal lactic acid bacteria....

  2. Bacteria-Mineral Interactions on the Surfaces of Metal-Resistant Bacteria

    International Nuclear Information System (INIS)

    Malkin, A.J.

    2010-01-01

    The extraordinary ability of indigenous microorganisms, like metal-resistant bacteria, for biotransformation of toxic compounds is of considerable interest for the emerging area of environmental bioremediation. However, the underlying mechanisms by which metal-resistant bacteria transform toxic compounds are currently unknown and await elucidation. The project's objective was to study stress-induced responses of metal-resistant bacteria to environmental changes and chemical stimulants. This project involved a multi-institutional collaboration of our LLNL group with the group of Dr. H.-Y. Holman (Lawrence Berkeley National Laboratory). In this project, we have utilized metal-resistant bacteria Arthrobacter oxydans as a model bacterial system. We have utilized atomic force microscopy (AFM) to visualize for the first time at the nanometer scale formation of stress-induced structures on bacterial surfaces in response to Cr (VI) exposure. We have demonstrated that structure, assembly, and composition of these stress-induced structures are dependent on Cr (VI) concentrations. Our AFM observations of the appearance and development of stress-induced layers on the surfaces of Arthrobacter oxydans bacteria exposed to Cr (VI) were confirmed by Dr. Holman's biochemical, electron microscopy, and synchrotron infrared spectromicroscopy studies. In general, in vitro imaging of live microbial and cellular systems represents one of the most challenging issues in application of AFM. Various approaches for immobilization of bacteria on the substrate for in vitro imaging were tested in this project. Imaging of live bacteria was achieved, however further optimization of experimental methods are needed for high-resolution visualization of the cellular environmental structural dynamics by AFM. This project enhanced the current insight into molecular architecture, structural and environmental variability of bacterial systems. The project partially funded research for two book chapters (1

  3. Screening and characterization of phosphate solubilizing bacteria from isolate of thermophilic bacteria

    Science.gov (United States)

    Yulianti, Evy; Rakhmawati, Anna

    2017-08-01

    The aims of this study were to select bacteria that has the ability to dissolve phosphate from thermophilic bacteria isolates after the Merapi eruption. Five isolates of selected bacteria was characterized and continued with identification. Selection was done by using a pikovskaya selective medium. Bacterial isolates were grown in selective medium and incubated for 48 hours at temperature of 55 ° C. Characterization was done by looking at the cell and colony morphology, physiological and biochemical properties. Identification was done with the Profile Matching method based on the reference genus Oscillospira traced through Bergey's Manual of Determinative Bacteriology. Dendogram was created based on similarity index SSM. The results showed there were 14 isolates of bacteria that were able to dissolve phosphate indicated by a clear zone surrounding the bacterial colony on selective media. Five isolates were selected with the largest clear zone. Isolates D79, D92, D110a, D135 and D75 have different characters. The result of phenotypic characters identification with Genus Oscillospira profile has a percentage of 100% similarity to isolate D92 and D110a; 92.31% for isolates D79, and 84.6% for isolates D75 and D135. Dendogram generated from average linkage algorithm / UPGMA using the Simple Matching Coefficient (SSM) algorithms showed, isolate thermophilic bacteria D75 and D135 are combined together to form cluster 1. D110a and D92 form a sub cluster A. Sub cluster A and D79 form cluster 2

  4. Probiotic bacteria in prevention and treatment of diarrhea

    Directory of Open Access Journals (Sweden)

    Jasmina Havranek

    2009-03-01

    Full Text Available Probiotic bacteria have beneficial effects in prevention and treatment of different diseases. The results of preventive and therapeutic effect of probiotic bacteria on diarrhea during last ten years are shown in this paper. The greatest preventive and therapeutic effect of probiotic bacteria was identified for acute diarrhea in children caused by rotaviruses. Significant, but slightly lower effect of probiotic bacteria was proved for antibiotic associated diarrhea. Positive effect in prevention of traveller’s diarrhea and radiation-induced diarrhea is not significant. Preventive and therapeutic effect on diarrhea is not dependent on the way of probiotic bacteria consumption, by fermented milk, capsule or oral rehydration solution.

  5. Seeing green bacteria in a new light: genomics-enabled studies of the photosynthetic apparatus in green sulfur bacteria and filamentous anoxygenic phototrophic bacteria

    DEFF Research Database (Denmark)

    Frigaard, Niels-Ulrik; Bryant, Donald A

    2004-01-01

    Based upon their photosynthetic nature and the presence of a unique light-harvesting antenna structure, the chlorosome, the photosynthetic green bacteria are defined as a distinctive group in the Bacteria. However, members of the two taxa that comprise this group, the green sulfur bacteria...... (Chlorobi) and the filamentous anoxygenic phototrophic bacteria ("Chloroflexales"), are otherwise quite different, both physiologically and phylogenetically. This review summarizes how genome sequence information facilitated studies of the biosynthesis and function of the photosynthetic apparatus...... and carotenoid species also allow the functions of these pigments to be studied in vivo....

  6. Bacteria-bacteria interactions within the microbiota of the ancestral metazoan Hydra contribute to fungal resistance.

    Science.gov (United States)

    Fraune, Sebastian; Anton-Erxleben, Friederike; Augustin, René; Franzenburg, Sören; Knop, Mirjam; Schröder, Katja; Willoweit-Ohl, Doris; Bosch, Thomas C G

    2015-07-01

    Epithelial surfaces of most animals are colonized by diverse microbial communities. Although it is generally agreed that commensal bacteria can serve beneficial functions, the processes involved are poorly understood. Here we report that in the basal metazoan Hydra, ectodermal epithelial cells are covered with a multilayered glycocalyx that provides a habitat for a distinctive microbial community. Removing this epithelial microbiota results in lethal infection by the filamentous fungus Fusarium sp. Restoring the complex microbiota in gnotobiotic polyps prevents pathogen infection. Although mono-associations with distinct members of the microbiota fail to provide full protection, additive and synergistic interactions of commensal bacteria are contributing to full fungal resistance. Our results highlight the importance of resident microbiota diversity as a protective factor against pathogen infections. Besides revealing insights into the in vivo function of commensal microbes in Hydra, our findings indicate that interactions among commensal bacteria are essential to inhibit pathogen infection.

  7. Superfícies do ambiente hospitalar como possíveis reservatórios de bactérias resistentes: uma revisão Superficies inanimadas del ambiente hospitalario como posibles reservorios de bacterias resistentes: una revisión Surfaces of the hospital environment as possible deposits of resistant bacteria: a review

    Directory of Open Access Journals (Sweden)

    Adriana Cristina de Oliveira

    2010-12-01

    microorganismos. Se verificó semejanza en las cepas aisladas de pacientes colonizados y/o infectados y del ambiente por tipificación molecular. Esas evidencias refuerzan la necesidad de conocimiento y control de fuentes de patógenos en el ambiente hospitalario.The main objective of this study is to identify, in the literature, articles about the occurrence of contamination from inanimate surfaces and a possible dissemination of resistant bacteria in the hospital environment. A bibliographic survey was performed with articles published in the databases LILACS, MEDLINE, Science Direct, SCOPUS and ISI Web of Knowledge, between 2000 and 2008. Twenty-one articles were selected and analyzed. The analyzed studies highlighted the presence of bacteria on monitors, bed grids, tables, faucets, telephones, keyboards and other objects. There was a prevalence of Staphylococcus aureus resistant to methicillin, Clostridium difficile, Acinetobacter baumannii and Enterococcus resistant to vancomycin, being the predictive factor the previous occupation of patients colonized by these microorganisms. There was a similarity observed among the isolated strains of colonized and/or infected patients and the strains of the environment by molecular typification. These evidences reinforce the need for knowledge and control of the sources of pathogens in the hospital environment.

  8. INTEGRACIÓN DE INDUCCIÓN DE RESISTENCIA CON BACTERIAS QUITINOLÍTICAS EN EL CONTROL DE LA SIGATOKA NEGRA (Mycosphaerella fijiensis Morelet EN BANANO INTEGRATION OF INDUCED RESISTANCE WITH CHITINOLYTIC BACTERIA IN BLACK SIGATOKA CONTROL (Mycosphaerella fijiensis Morelet IN BANANA

    Directory of Open Access Journals (Sweden)

    Catalina María Zuluaga Amaya

    2007-12-01

    Full Text Available Se evaluó en condiciones de campo en la zona bananera de Urabá-Colombia, el efecto de inductores de resistencia y bacterias quitinolíticas sobre el desarrollo de la Sigatoka Negra en plantas de banano del cultivar Gran Enano. Como inductores de resistencia se utilizaron acibenzolar-s-metil (ASM (20 cm³ · ha-1 i.a. y ácido salicílico (AS (20 cm³ · ha-1 i.a cada uno en rotación y en mezcla con fungicidas utilizados en el control convencional de la enfermedad; se evaluó también la mezcla de estos inductores con bacterias quitinolíticas aisladas de la filosfera de banano; así como el efecto del fungicida biológico Biofun® ( 1,5 L · ha-1 de p.c. en rotación con fungicidas y en mezcla con ASM. La aplicación de ASM en rotación y en mezcla con fungicidas convencionales presentó un control de la enfermedad hasta un 50% mayor al obtenido con el control convencional, evidenciado esto en los valores más bajos del área bajo la curva del índice de severidad de la enfermedad (IS y más altos de hojas sanas (HS al momento de la floración. Los tratamientos, que incluyeron AS en rotación y mezcla con fungicidas convencionales, al igual que el producto Biofun® en rotación y en mezcla con ASM, mostraron un control de la enfermedad estadísticamente igual al obtenido con el control convencional, lo cual reveló una reducción de 46 - 100% de la cantidad de fungicidas convencionales usados en el control de la Sigatoka Negra.The effect of resistance elicitors and chitinolytic bacteria was evaluated on Black Sigatoka control in banana plants, in field conditions in Urabá-Colombia. Acibenzolar-s-metil (ASM (20 cm³ · ha- 1 a.i. and salicilyc acid (SA (20 cm³ a.i.ha-1 were used in rotation and mixture with conventional fungicides, and in mixture with chitinolytic bacteria isolated from banana phyllosphere. Biological fungicide Biofun® ( 1,5 L · ha-1 de p.c. was also tested in rotation and mixture with ASM. When fungicides were in rotation

  9. Hessian fly-associated bacteria: transmission, essentiality, and composition.

    Directory of Open Access Journals (Sweden)

    Raman Bansal

    Full Text Available Plant-feeding insects have been recently found to use microbes to manipulate host plant physiology and morphology. Gall midges are one of the largest groups of insects that manipulate host plants extensively. Hessian fly (HF, Mayetiola destructor is an important pest of wheat and a model system for studying gall midges. To examine the role of bacteria in parasitism, a systematic analysis of bacteria associated with HF was performed for the first time. Diverse bacteria were found in different developmental HF stages. Fluorescent in situ hybridization detected a bacteriocyte-like structure in developing eggs. Bacterial DNA was also detected in eggs by PCR using primers targeted to different bacterial groups. These results indicated that HF hosted different types of bacteria that were maternally transmitted to the next generation. Eliminating bacteria from the insect with antibiotics resulted in high mortality of HF larvae, indicating that symbiotic bacteria are essential for the insect to survive on wheat seedlings. A preliminary survey identified various types of bacteria associated with different HF stages, including the genera Enterobacter, Pantoea, Stenotrophomonas, Pseudomonas, Bacillus, Ochrobactrum, Acinetobacter, Alcaligenes, Nitrosomonas, Arcanobacterium, Microbacterium, Paenibacillus, and Klebsiella. Similar bacteria were also found specifically in HF-infested susceptible wheat, suggesting that HF larvae had either transmitted bacteria into plant tissue or brought secondary infection of bacteria to the wheat host. The bacteria associated with wheat seedlings may play an essential role in the wheat-HF interaction.

  10. Enhanced analysis of bacteria susceptibility in connected biofilms.

    Science.gov (United States)

    Sommerfeld Ross, Stacy; Reinhardt, Joseph M; Fiegel, Jennifer

    2012-07-01

    A common method for visualizing bacterial biofilms is through confocal laser scanning microscopy images. Current software packages separate connected-biofilm bacteria from unconnected bacteria, such as planktonic or dispersed bacteria, but do not save both image sequences, making interpretation of the two bacterial populations difficult. Thus we report the development of an algorithm to save separate image sequences and enable qualitative and quantitative evaluation of each bacterial population. To improve bacterial viability assessment using a membrane integrity dye, a colocalization algorithm was also developed. This assigns colocalized pixels to the dead bacteria population, rather than to both the live and dead bacteria groups. Visually, this makes it clearer to distinguish a green live bacteria pixel from a yellow colocalized dead bacteria pixel. This algorithm also aids in the quantification of viability for connected-biofilm bacteria and unconnected bacteria to investigate susceptibility of each population to antimicrobials. The utility of these algorithms was demonstrated with Pseudomonas aeruginosa biofilms treated with ciprofloxacin hydrochloride. Results from this study indicate that quantification with colocalization adjustment can prevent underestimation of dead bacteria. These improvements in image processing will enable researchers to visually differentiate connected-biofilm and unconnected bacteria in a single image and to quantify these populations independently for viability without double counting the colocalized image pixels. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. Probiotic bacteria: selective enumeration and survival in dairy foods.

    Science.gov (United States)

    Shah, N P

    2000-04-01

    A number of health benefits have been claimed for probiotic bacteria such as Lactobacillus acidophilus, Bifidobacterium spp., and Lactobacillus casei. Because of the potential health benefits, these organisms are increasingly incorporated into dairy foods. However, studies have shown low viability of probiotics in market preparations. In order to assess viability of probiotic bacteria, it is important to have a working method for selective enumeration of these probiotic bacteria. Viability of probiotic bacteria is important in order to provide health benefits. Viability of probiotic bacteria can be improved by appropriate selection of acid and bile resistant strains, use of oxygen impermeable containers, two-step fermentation, micro-encapsulation, stress adaptation, incorporation of micronutrients such as peptides and amino acids and by sonication of yogurt bacteria. This review will cover selective enumeration and survival of probiotic bacteria in dairy foods.

  12. Suppression of Enteric Bacteria by Bacteriophages: Importance of Phage Polyvalence in the Presence of Soil Bacteria.

    Science.gov (United States)

    Yu, Pingfeng; Mathieu, Jacques; Yang, Yu; Alvarez, Pedro J J

    2017-05-02

    Bacteriophages are widely recognized for their importance in microbial ecology and bacterial control. However, little is known about how phage polyvalence (i.e., broad host range) affects bacterial suppression and interspecies competition in environments harboring enteric pathogens and soil bacteria. Here we compare the efficacy of polyvalent phage PEf1 versus coliphage T4 in suppressing a model enteric bacterium (E. coli K-12) in mixtures with soil bacteria (Pseudomonas putida F1 and Bacillus subtilis 168). Although T4 was more effective than PEf1 in infecting E. coli K-12 in pure cultures, PEf1 was 20-fold more effective in suppressing E. coli under simulated multispecies biofilm conditions because polyvalence enhanced PEf1 propagation in P. putida. In contrast, soil bacteria do not propagate coliphages and hindered T4 diffusion through the biofilm. Similar tests were also conducted under planktonic conditions to discern how interspecies competition contributes to E. coli suppression without the confounding effects of restricted phage diffusion. Significant synergistic suppression was observed by the combined effects of phages plus competing bacteria. T4 was slightly more effective in suppressing E. coli in these planktonic mixed cultures, even though PEf1 reached higher concentrations by reproducing also in P. putida (7.2 ± 0.4 vs 6.0 ± 1.0 log 10 PFU/mL). Apparently, enhanced suppression by higher PEf1 propagation was offset by P. putida lysis, which decreased stress from interspecies competition relative to incubations with T4. In similar planktonic tests with more competing soil bacteria species, P. putida lysis was less critical in mitigating interspecies competition and PEf1 eliminated E. coli faster than T4 (36 vs 42 h). Overall, this study shows that polyvalent phages can propagate in soil bacteria and significantly enhance suppression of co-occurring enteric species.

  13. Probiotic bacteria survive in Cheddar cheese and modify populations of other lactic acid bacteria.

    Science.gov (United States)

    Ganesan, B; Weimer, B C; Pinzon, J; Dao Kong, N; Rompato, G; Brothersen, C; McMahon, D J

    2014-06-01

    Starter lactic acid bacteria in Cheddar cheese face physico-chemical stresses during manufacture and ageing that alter their abilities to survive and to interact with other bacterial populations. Nonstarter bacteria are derived from milk handling, cheese equipment and human contact during manufacture. Probiotic bacteria are added to foods for human health benefits that also encounter physiological stresses and microbial competition that may mitigate their survival during ageing. We added probiotic Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus paracasei and Bifidobacterium animalis subsp. lactis to full-fat, reduced-fat and low-fat Cheddar cheeses, aiming to study their survival over 270 days of ageing and to determine the role of the cheese matrix in their survival. Probiotic and other lactic acid bacterial populations were enumerated by quantitative PCR using primers specifically targeting the different bacterial genera or species of interest. Bifidobacteria were initially added at 10(6) CFU g(-1) cheese and survived variably in the different cheeses over the 270-day ageing process. Probiotic lactobacilli that were added at 10(7) CFU g(-1) cheese and incident nonstarter lactobacilli (initially at 10(8) CFU g(-1) cheese) increased by 10- to 100-fold over 270 days. Viable bacterial populations were differentiated using propidium monoazide followed by species-specific qPCR assays, which demonstrated that the starter and probiotic microbes survived over ageing, independent of cheese type. Addition of probiotic bacteria, at levels 100-fold below that of starter bacteria, modified starter and nonstarter bacterial levels. We demonstrated that starter lactococci, nonstarter lactobacilli and probiotic bacteria are capable of surviving throughout the cheesemaking and ageing process, indicating that delivery via hard cheeses is possible. Probiotic addition at lower levels may also alter starter and nonstarter bacterial survival. We applied qPCR to study

  14. Introduce of Viable But Nonculturable Bacteria

    Directory of Open Access Journals (Sweden)

    Mehdi Hassanshahian

    2008-03-01

    Full Text Available Viable-But-Nonculturable-State (VBNC is the condition in which bacteria fail to grow on their routine bacteriological media where they would normally grow and develop into colonies, but are still alive and capable of renewed metabolic activity. VBNC state is useful for evaluating public health and for ascertaining the sterility of drinking water, pharmaceuticals, and foodstuff. A number of bacteria, mostly pathogenic to humans, have been proved to enter into this state in response to natural stresses such as starvation, incubation out of optimum growth temperature, increased osmotic pressure, etc. Once in the VBNC state, they undergo various physiological, structural, and genetic alterations. These alterations result in reduced cell size, conversion from bacilli to coccid, thickened cell walls, and peptidoglycan gaining many cross links. Metabolic changes also occur that include reductions in growth, nutrient transport, and respiratory rate; biosynthesis of new protein, and ATP remaining at a constant level. It has been shown that in the VBNC state, some pathogens conserve their virulence properties. Gene expression continues in the VBNC cell. Nucleic acids remain intact in the early VBNC phase but they gradually undergo degradation with prolonged VBNC. Cytological methods such as direct viable count and reduction of tetrazolium salts, and molecular methods such as reverse transcription polymerase chain reaction and green fluorescent protein have been used for the study of VBNC. Resuscitation from VBNC state starts when the inducing factor(s is/are lifted. Factors that help the resuscitation of VBNC bacteria include addition of certain nutrients and chemicals, introduction of a few culturable cells into the VBNC cell population, and passage through the animal host. As virulence properties are sustained during the VBNC phase, special care must be paid when evaluating sterility of drinking water.

  15. Do foliar endophytic bacteria fix nitrogen?

    Science.gov (United States)

    Kueppers, L. M.; Moyes, A. B.; Frank, C.; Pett-Ridge, J.; Carper, D.; Vandehey, N.; O'Neil, J.; Dekas, A.

    2015-12-01

    Endophytic microorganisms - bacteria and fungi that live inside healthy plant tissue - are a relatively unexplored source of functional diversity in natural ecosystems. Prior to modern sequencing technology, detecting uncultured endophytic bacteria and assessing their putative functions was challenging. However, recent work has revealed a remarkable diversity of as yet non-culturable endophytic taxa and is beginning to identify functional roles within plant microbiomes. We recently examined bacterial communities in the foliage of a long-lived, high-elevation conifer species, limber pine (Pinus flexilis), and discovered a community strongly dominated by acetic acid bacteria (Acetobacteraceae), with several taxa closely related to known nitrogen fixers. Given limber pine's status as a pioneer species that is able to grow in low fertility soils, we hypothesized that this bacterial community has a potential functional role in fixing atmospheric nitrogen, providing a source of this limiting nutrient to the host tree. We used the radioisotope 13N2 to confirm that N2 rapidly diffuses into pine needles, where it could potentially be fixed. With an acetylene reduction assay we confirmed nitrogenase enzyme activity inside excised twigs 4 times over a growing season, and estimate potential rates of N2 fixation at 0.1 nmol N2 g needle-1 hr-1. Scaled to the stand level, this N input could be on the order of ~20 mg N m-2 d-1 over a growing season. While these rates are low, the long lifespan of individual trees (~1000 years) makes them biologically meaningful. Still, measured rates of acetylene reduction and bulk 15N2 incorporation are quite variable in space and time. Much work remains to better characterize the plant-microbial interactions in this system, including the rates of nitrogen fixation and their variability over the growing season, across edaphic conditions, among host species, and through plant development; and to determine which community members are responsible

  16. Polymer/bacteria composite nanofiber non-wovens by electrospinning of living bacteria protected by hydrogel microparticles.

    Science.gov (United States)

    Gensheimer, Marco; Brandis-Heep, Astrid; Agarwal, Seema; Thauer, Rudolf K; Greiner, Andreas

    2011-03-10

    Physically crosslinked PVA-hydrogel microparticles are utilized for encapsulation of E. coli and M. luteus. The bacteria survive dry storage or treatment with bacteria-hostile organic solvents significantly better than unprotected bacteria as proven by culture-test experiments. The bacteria-protecting PVA microparticles are available for standard polymer-solution-processing techniques, as exemplarily shown by co-electrospinning of living bacteria encapsulated in dry PVA-hydrogel microparticles together with PVB-, PLLA-, and PCL-form organic solvents. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Modeling Transformation and Conjugation in Bacteria Populations

    Science.gov (United States)

    Russo, John; Dong, J. J.

    The rise of antibiotic resistance in bacteria populations is a growing threat to medical treatment of diseases. Transformation, where a cell absorbs a plasmid from its environment, and conjugation, direct transfer of a plasmid from one cell to another, are the two main mechanisms of emergence of antibiotic resistance. We model the processes using a combined approach of Kinetic Monte Carlo simulation and differential equations to describe the plasmid-carrying and plasmid-free populations. Through analysis of our results, we characterize the conditions that lead to dominance of the antibiotic resistant population. NSF-DMR #1248387.

  18. Polymorphic transformation of helical flagella of bacteria

    Science.gov (United States)

    Lim, Sookkyung; Howard Berg Collaboration; William Ko Collaboration; Yongsam Kim Collaboration; Wanho Lee Collaboration; Charles Peskin Collaboration

    2016-11-01

    Bacteria such as E. coli swim in an aqueous environment by utilizing the rotation of flagellar motors and alternate two modes of motility, runs and tumbles. Runs are steady forward swimming driven by bundles of flagellar filaments whose motors are turning CCW; tumbles involve a reorientation of the direction of swimming triggered by motor reversals. During tumbling, the helical flagellum undergoes polymorphic transformations, which is a local change in helical pitch, helical radius, and handedness. In this work, we investigate the underlying mechanism of structural conformation and how this polymorphic transition plays a role in bacterial swimming. National Science Foundation.

  19. The Origin And Spread Of Airborne Bacteria

    Science.gov (United States)

    Henderson-Begg, S. K.; Moffett, B. F.

    2009-12-01

    The presence of bacteria in clouds may affect their radiation and precipitation properties as some species are able to catalyse the freezing of water at high temperatures (-2C to -10C). Where cloud-borne bacteria originate and the distances they are able to travel in the air remains a mystery. In this study we have attempted to address these issues by comparing metagenomic DNA sequences from air samples with those from other environmental sources. Air samples were collected on 1 July 2009 from a hill top at Thursley Nature Reserve in Surrey, United Kingdom, a rural site, 31 miles from the nearest stretch of coastline, and on 6 July 2009 from the top of a six storey building in Stratford on the East end of London, 38 miles from the nearest coastal area. Samples were collected using the Karcher DS5500 vacuum into a liquid filled collection vessel at an air flow rate of 3.3 m3 min-1 over a 4 hour period. Samples were then concentrated and the bacterial content was investigated by PCR, cloning and sequencing of 16S rRNA genes. During the collection period on 1 July the Royston Weather Station in the South East of England recorded wind speed of 1.9 miles/hour in an Easterly direction, with no cloud cover, relative humidity of 74% and atmospheric pressure of 1021.6 mB. On 6 July wind speed was 9.8 miles/hour in a South Westerly direction, there was light cloud cover, relative humidity was 73.8% and atmospheric pressure was 1002.8 mB. Twenty cloned 16S PCR products from each air sample were sequenced. The species identification of each clone is shown in Table 1. The diversity of bacteria found at both sites was similar, with Stenotrophomona and Pedobacteria species dominating both samples. When the DNA sequences were blasted against the environmental samples database, all sequences were found to display greatest homology to metagenomic DNA from marine sources. This may suggest that the most numerous bacteria in air samples originate in the oceans. Taking account of the

  20. Phosphate solubilizing bacteria around Indian peninsula

    Digital Repository Service at National Institute of Oceanography (India)

    De; Nair, S.; Chandramohan, D.

    compounds especially in environments where low concentrations of phosphorus causes various limitations. References 1 Pomeroy L R, Smith E & Giant C M, Limnol Oceanogr, 10 (1965) 167 2 Gachter R, Meyer } S & Mares A, Limnol Oceanogr, 33 (1988) 1542. 3... of Marine Sciences Vol. 29, March 2000, pp. 48-51 Phosphate solubilizing bacteria around Indian peninsula M-J. B. D. De Souza, S. Nair & D. Chandramohan National Institute of Oceanography, Dona Paula, Goa 403 004 India Received 29 July 1998, revised 16...

  1. Are Bacteria more dangerous in space?

    International Nuclear Information System (INIS)

    Leys, N.; Baatout, S.

    2010-01-01

    With a mission to Mars and a permanent base on the moon as the ultimate dream, space travel is continually pushing back the frontiers. But long space missions present great challenges for science, for example in the field of microbiology. Together with the European Space Agency (ESA), SCK-CEN is studying the effects of space travel conditions on the behaviour of bacteria. In 2009 the SCK-CEN experts completed four innovative research projects at the cutting edge of microbiology, radiation sciences and space travel.

  2. The Interaction between Heterotrophic Bacteria and Coliform, Fecal Coliform, Fecal Streptococci Bacteria in the Water Supply Networks.

    Science.gov (United States)

    Amanidaz, Nazak; Zafarzadeh, Ali; Mahvi, Amir Hossein

    2015-12-01

    This study investigated the interaction between heterotrophic bacteria and coliform, fecal coliforms, fecal streptococci bacteria in water supply networks. This study was conducted during 2013 on water supply distribution network in Aq Qala City, Golestan Province, Northern Iran and standard methods were applied for microbiological analysis. The surface method was applied to test the heterotrophic bacteria and MPN method was used for coliform, fecal coliform and fecal streptococci bacteria measurements. In 114 samples, heterotrophic bacteria count were over 500 CFU/ml, which the amount of fecal coliform, coliform, and fecal streptococci were 8, 32, and 20 CFU/100 ml, respectively. However, in the other 242 samples, with heterotrophic bacteria count being less than 500 CFU/ml, the amount of fecal coliform, coliform, and fecal streptococci was 7, 23, and 11 CFU/100ml, respectively. The relationship between heterotrophic bacteria, coliforms and fecal streptococci was highly significant (Pcoliforms, fecal streptococci bacteria being high, whenever the concentration of heterotrophic bacteria in the water network systems was high. Interaction between heterotrophic bacteria and coliform, fecal coliforms, fecal streptococci bacteria in the Aq Qala City water supply networks was not notable. It can be due to high concentrations of organic carbon, bio-films and nutrients, which are necessary for growth, and survival of all microorganisms.

  3. Inoculation of sugarcane with diazotrophic bacteria

    Directory of Open Access Journals (Sweden)

    Nivaldo Schultz

    2014-04-01

    Full Text Available The sugarcane industry, a strategic crop in Brazil, requires technological improvements in production efficiency to increase the crop energy balance. Among the various currently studied alternatives, inoculation with diazotrophic bacteria proved to be a technology with great potential. In this context, the efficiency of a mixture of bacterial inoculant was evaluated with regard to the agronomic performance and N nutrition of sugarcane. The experiment was carried out on an experimental field of Embrapa Agrobiologia, in Seropédica, Rio de Janeiro, using a randomized block, 2 × 3 factorial design (two varieties and three treatments with four replications, totaling 24 plots. The varieties RB867515 and RB72454 were tested in treatments consisting of: inoculation with diazotrophic bacteria, N-fertilized control with 120 kg ha-1 N and absolute control (no inoculation and no N fertilizer. The inoculum was composed of five strains of five diazotrophic species. The yield, dry matter accumulation, total N in the shoot dry matter and the contribution of N by biological fixation were evaluated, using the natural 15N abundance in non-inoculated sugarcane as reference. The bacterial inoculant increased the stalk yield of variety RB72454 similarly to fertilization with 120 kg ha-1 N in the harvests of plant-cane and first ratoon crops, however the contribution of biological N fixation was unchanged by inoculation, indicating that the benefits of the inoculant in sugarcane may have resulted from plant growth promotion.

  4. Conjugation in Gram-Positive Bacteria.

    Science.gov (United States)

    Goessweiner-Mohr, Nikolaus; Arends, Karsten; Keller, Walter; Grohmann, Elisabeth

    2014-08-01

    Conjugative transfer is the most important means of spreading antibiotic resistance and virulence factors among bacteria. The key vehicles of this horizontal gene transfer are a group of mobile genetic elements, termed conjugative plasmids. Conjugative plasmids contain as minimum instrumentation an origin of transfer (oriT), DNA-processing factors (a relaxase and accessory proteins), as well as proteins that constitute the trans-envelope transport channel, the so-called mating pair formation (Mpf) proteins. All these protein factors are encoded by one or more transfer (tra) operons that together form the DNA transport machinery, the Gram-positive type IV secretion system. However, multicellular Gram-positive bacteria belonging to the streptomycetes appear to have evolved another mechanism for conjugative plasmid spread reminiscent of the machinery involved in bacterial cell division and sporulation, which transports double-stranded DNA from donor to recipient cells. Here, we focus on the protein key players involved in the plasmid spread through the two different modes and present a new secondary structure homology-based classification system for type IV secretion protein families. Moreover, we discuss the relevance of conjugative plasmid transfer in the environment and summarize novel techniques to visualize and quantify conjugative transfer in situ.

  5. Detection of phenols using engineered bacteria

    Science.gov (United States)

    Wise, Arlene A.; Kuske, Cheryl R.; Terwilliger, Thomas C.

    2007-12-04

    Detection of phenols using engineered bacteria. A biosensor can be created by placing a reporter gene under control of an inducible promoter. The reporter gene produces a signal when a cognate transcriptional activator senses the inducing chemical. Creation of bacterial biosensors is currently restricted by limited knowledge of the genetic systems of bacteria that catabolize xenobiotics. By using mutagenic PCR to change the chemical specificity of the Pseudomonas species CF600 DmpR protein, the potential for engineering novel biosensors for detection of phenols has been demonstrated. DmpR, a well-characterized transcriptional activator of the P. CF600's dmp operon mediates growth on simple phenols. Transcription from Po, the promoter heading the dmp operon, is activated when the sensor domain of DmpR interacts with phenol and mono-substituted phenols. By altering the sensor domain of the DmpR, a group of DmpR derivatives that activate transcription of a Po-lacZ fusion in response to eight of the EPA's eleven priority pollutant phenols has been created. The assays and the sensor domain mutations that alter the chemical specificity of DmpR is described.

  6. Starvation-survival of subsurface bacteria

    International Nuclear Information System (INIS)

    Magill, N.G.

    1988-01-01

    The ability of four subsurface isolates to survive starvation was examined and the results were compared to survival curves obtained for Escherichia coli B and Serratia marcescens. To examine the starvation-survival phenomenon further, several experimental parameters including nutritional history, initial cell density, growth phase, temperature of growth and starvation, and aeration. Nutritional history, initial cell density, and growth phases of the cells had some effect on the ability of these bacteria to survive whereas temperature and limited aeration had no effect under the conditions tested. No conditions were found where E. coli B or Serratia marcescens died rapidly or where less than 10% of the original cell number of viable cells remained. Because the apparent survival of these bacteria may be due to cryptic growth, cross-feeding experiments with 14 C-labeled cells and unlabeled cells were carried out with E. coli B and Pseudomonas Lula V. Leaked extracellular 14 C-compounds were not used for growth or maintenance energy, and were not taken up by either bacterium. Cryptic growth did not occur; the cells were truly starving under the experimental conditions used

  7. Beneficial effects of antioxidative lactic acid bacteria

    Directory of Open Access Journals (Sweden)

    Hisako Nakagawa

    2017-01-01

    Full Text Available Oxidative stress is caused by exposure to reactive oxygen intermediates. The oxidative damage of cell components such as proteins, lipids, and nucleic acids one of the important factors associated with diabetes mellitus, cancers and cardiovascular diseases. This occurs as a result of imbalance between the generations of oxygen derived radicals and the organism’s antioxidant potential. The amount of oxidative damage increases as an organism ages and is postulated to be a major causal factor of senescence. To date, many studies have focused on food sources, nutrients, and components that exert antioxidant activity in worms, flies, mice, and humans. Probiotics, live microorganisms that when administered in adequate amounts provide many beneficial effects on the human health, have been attracting growing interest for their health-promoting effects, and have often been administered in fermented milk products. In particular, lactic acid bacteria (LAB are known to conferre physiologic benefits. Many studies have indicated the antioxidative activity of LAB. Here we review that the effects of lactic acid bacteria to respond to oxidative stress, is connected to oxidative-stress related disease and aging.

  8. Cyanobacterial Toxin Degrading Bacteria: Who Are They?

    Directory of Open Access Journals (Sweden)

    Konstantinos Ar. Kormas

    2013-01-01

    Full Text Available Cyanobacteria are ubiquitous in nature and are both beneficial and detrimental to humans. Benefits include being food supplements and producing bioactive compounds, like antimicrobial and anticancer substances, while their detrimental effects are evident by toxin production, causing major ecological problems at the ecosystem level. To date, there are several ways to degrade or transform these toxins by chemical methods, while the biodegradation of these compounds is understudied. In this paper, we present a meta-analysis of the currently available 16S rRNA and mlrA (microcystinase genes diversity of isolates known to degrade cyanobacterial toxins. The available data revealed that these bacteria belong primarily to the Proteobacteria, with several strains from the sphingomonads, and one from each of the Methylobacillus and Paucibacter genera. Other strains belonged to the genera Arthrobacter, Bacillus, and Lactobacillus. By combining the ecological knowledge on the distribution, abundance, and ecophysiology of the bacteria that cooccur with toxic cyanobacterial blooms and newly developed molecular approaches, it is possible not only to discover more strains with cyanobacterial toxin degradation abilities, but also to reveal the genes associated with the degradation of these toxins.

  9. Bacteria in atmospheric waters: Detection, characteristics and implications

    Science.gov (United States)

    Hu, Wei; Niu, Hongya; Murata, Kotaro; Wu, Zhijun; Hu, Min; Kojima, Tomoko; Zhang, Daizhou

    2018-04-01

    In this review paper, we synthesize the current knowledges about bacteria in atmospheric waters, e.g., cloud, fog, rain, and snow, most of which were obtained very recently. First, we briefly describe the importance of bacteria in atmospheric waters, i.e., the essentiality of studying bacteria in atmospheric waters in understanding aerosol-cloud-precipitation-climate interactions in the Earth system. Next, approaches to collect atmospheric water samples for the detection of bacteria and methods to identify the bacteria are summarized and compared. Then the available data on the abundance, viability and community composition of bacteria in atmospheric waters are summarized. The average bacterial concentration in cloud water was usually on the order 104-105 cells mL-1, while that in precipitation on the order 103-104 cells mL-1. Most of the bacteria were viable or metabolically active. Their community composition was highly diverse and differed at various sites. Factors potentially influencing the bacteria, e.g., air pollution levels and sources, meteorological conditions, seasonal effect, and physicochemical properties of atmospheric waters, are described. After that, the implications of bacteria present in atmospheric waters, including their effect on nucleation in clouds, atmospheric chemistry, ecosystems and public health, are briefly discussed. Finally, based on the current knowledges on bacteria in atmospheric waters, which in fact remains largely unknown, we give perspectives that should be paid attention to in future studies.

  10. Sulphur bacteria mediated formation of Palaeoproterozoic phosphorites

    Science.gov (United States)

    Joosu, Lauri; Lepland, Aivo; Kirsimäe, Kalle

    2014-05-01

    Modern phosphorite formation is typically associated with high productivity in upwelling areas where apatite (Ca-phosphate) precipitation is mediated by sulphur oxidising bacteria [1]. They inhabit the oxic/anoxic interface within the upper few centimetres of sediment column, accumulating phosphate in their cells under oxic conditions and releasing it rapidly when conditions become anoxic. Sulphur bacteria are known to live in close association with a consortium of anaerobic methane oxidising archaea and syntrophic sulphate-reducing bacteria. Paleoproterozoic, c. 2.0 Ga Zaonega Formation in Karelia, Russia contains several P-rich intervals in the upper part of 1500 m thick succession of organic-rich sedimentary rocks interlayered with mafic tuffs and lavas. Apatite in these P-rich intervals forms impure laminae, lenses and round-oval nodules which diameters typically range from 300 to 1000 μm. Individual apatite particles in P-rich laminae and nodules commonly occur as cylinders that are 1-8 μm long and have diameters of 0.5-4 μm. Cross-sections of best preserved cylindrical apatite particles reveal a thin outer rim whereas the internal parts consist of small anhedral elongated crystallites, intergrown with carbonaceous material. During recrystallization the outer rim thickens towards interior and cylinders may attain hexagonal crystal habit, but their size and shape remains largely unchanged [2]. The sizes of Zaonega nodules are similar to giant sulphide-oxidising bacteria known from modern and ancient settings [3, 4]. Individual apatite cylinders and aggregates have shapes and sizes similar to the methanotrophic archaea that inhabit microbial mats in modern seep/vent areas where they operate in close associations with sulphur-oxidising microbial communities [5]. Seep/vent influence during the Zaonega phosphogenesis is indicated by variable, though positive Eu anomaly, expected in magmatically active sedimentary environment experiencing several lava flows

  11. Identification of Lactic Acid Bacteria and Propionic Acid Bacteria using FTIR Spectroscopy and Artificial Neural Networks

    Directory of Open Access Journals (Sweden)

    Beata Nalepa

    2012-01-01

    Full Text Available In the present study, lactic acid bacteria and propionic acid bacteria have been identified at the genus level with the use of artificial neural networks (ANNs and Fourier transform infrared spectroscopy (FTIR. Bacterial strains of the genera Lactobacillus, Lactococcus, Leuconostoc, Streptococcus and Propionibacterium were analyzed since they deliver health benefits and are routinely used in the food processing industry. The correctness of bacterial identification by ANNs and FTIR was evaluated at two stages. At first stage, ANNs were tested based on the spectra of 66 reference bacterial strains. At second stage, the evaluation involved 286 spectra of bacterial strains isolated from food products, deposited in our laboratory collection, and identified by genus-specific PCR. ANNs were developed based on the spectra and their first derivatives. The most satisfactory results were reported for the probabilistic neural network, which was built using a combination of W5W4W3 spectral ranges. This network correctly identified the genus of 95 % of the lactic acid bacteria and propionic acid bacteria strains analyzed.

  12. The effect of lactic acid bacteria on cocoa bean fermentation.

    Science.gov (United States)

    Ho, Van Thi Thuy; Zhao, Jian; Fleet, Graham

    2015-07-16

    Cocoa beans (Theobroma cacao L.) are the raw material for chocolate production. Fermentation of cocoa pulp by microorganisms is crucial for developing chocolate flavor precursors. Yeasts conduct an alcoholic fermentation within the bean pulp that is essential for the production of good quality beans, giving typical chocolate characters. However, the roles of bacteria such as lactic acid bacteria and acetic acid bacteria in contributing to the quality of cocoa bean and chocolate are not fully understood. Using controlled laboratory fermentations, this study investigated the contribution of lactic acid bacteria to cocoa bean fermentation. Cocoa beans were fermented under conditions where the growth of lactic acid bacteria was restricted by the use of nisin and lysozyme. The resultant microbial ecology, chemistry and chocolate quality of beans from these fermentations were compared with those of indigenous (control) fermentations. The yeasts Hanseniaspora guilliermondii, Pichia kudriavzevii, Kluyveromyces marxianus and Saccharomyces cerevisiae, the lactic acid bacteria Lactobacillus plantarum, Lactobacillus pentosus and Lactobacillus fermentum and the acetic acid bacteria Acetobacter pasteurianus and Gluconobacter frateurii were the major species found in control fermentations. In fermentations with the presence of nisin and lysozyme, the same species of yeasts and acetic acid bacteria grew but the growth of lactic acid bacteria was prevented or restricted. These beans underwent characteristic alcoholic fermentation where the utilization of sugars and the production of ethanol, organic acids and volatile compounds in the bean pulp and nibs were similar for beans fermented in the presence of lactic acid bacteria. Lactic acid was produced during both fermentations but more so when lactic acid bacteria grew. Beans fermented in the presence or absence of lactic acid bacteria were fully fermented, had similar shell weights and gave acceptable chocolates with no differences

  13. Reactivity of the Bacteria-Water Interface: Linking Nutrient Availability to Bacteria-Metal Interactions

    Science.gov (United States)

    Fowle, D. A.; Daughney, C. J.; Riley, J. L.

    2002-12-01

    Identifying and quantifying the controls on metal mobilities in geologic systems is critical in order to understand processes such as global element cycling, metal transport in near-surface water-rock systems, sedimentary diagenesis, and mineral formation. Bacteria are ubiquitous in near-surface water-rock systems, and numerous laboratory and field studies have demonstrated that bacteria can facilitate the formation and dissolution of minerals, and enhance or inhibit contaminant transport. However, despite the growing evidence that bacteria play a key role in many geologic processes in low temperature systems, our understanding of the influence of the local nutrient dynamics of the system of interest on bacteria-metal interactions is limited. Here we present data demonstrating the effectiveness of coupling laboratory experiments with geochemical modeling to isolate the effect of nutrient availability on bacterially mediated proton and metal adsorption reactions. Experimental studies of metal-bacteria interactions were conducted in batch reactors as a function of pH, and solid-solute interactions after growth in a variety of defined and undefined media. Media nutrient composition (C,N,P) was quantified before and after harvesting the cells. Surface complexation models (SCM) for the adsorption reactions were developed by combining sorption data with the results of acid-base titrations, and in some cases zeta potential titrations of the bacterial surface. Our results indicate a clear change in both buffering potential and metal binding capacity of the cell walls of Bacillus subtilis as a function of initial media conditions. Combining current studies with our past studies on the effects of growth phase and others work on temperature dependence on metal adsorption we hope to develop a holistic surface complexation model for quantifying bacterial effects on metal mass transfer in many geologic systems.

  14. The role of adhesins in bacteria motility modification

    Science.gov (United States)

    Conrad, Jacinta; Gibiansky, Maxsim; Jin, Fan; Gordon, Vernita; Motto, Dominick; Shrout, Joshua; Parsek, Matthew; Wong, Gerard

    2010-03-01

    Bacterial biofilms are multicellular communities responsible for a broad range of infections. To investigate the early-stage formation of biofilms, we have developed high-throughput techniques to quantify the motility of surface-associated bacteria. We translate microscopy movies of bacteria into a searchable database of trajectories using tracking algorithms adapted from colloidal physics. By analyzing the motion of both wild-type (WT) and isogenic knockout mutants, we have previously characterized fundamental motility mechanisms in P. aeruginosa. Here, we develop biometric routines to recognize signatures of adhesion and trapping. We find that newly attached bacteria move faster than previously adherent bacteria, and are more likely to be oriented out-of-plane. Motility appendages influence the bacterium's ability to become trapped: WT bacteria exhibit two types of trapped trajectories, whereas flagella-deficient bacteria rarely become trapped. These results suggest that flagella play a key role in adhesion.

  15. Roseobacter-clade bacteria as probiotics in marine larvaeculture

    DEFF Research Database (Denmark)

    Grotkjær, Torben

    Disease caused by fish pathogenic bacteria can cause large scale crashes in marine fish larval rearing units. One of the biggest challenges for aquaculture is the management of these bacterial outbreaks. Vaccines can be admitted to fish but only the juvenile and the adult fish because they need...... to human pathogens. Alternatives are therefore needed and one could be the use of probiotic bacteria. Marine bacteria from the Roseobacter clade (Phaeobacter inhibens) have shown great potential as probiotic bacteria, and we have hypothesized that they could be used to antagonize pathogenic fish...... and crustacean bacteria in the environment of the larvae. The purpose of the present PhD study was to determine if antagonistic Roseobacter clade bacteria occurred in marine aquaculture units. The study would determine their clonal relationship and elucidate the mechanisms by which these potential probiotic...

  16. Influence of irradiation of bacteria on their thermoresistance

    Energy Technology Data Exchange (ETDEWEB)

    Szulc, M.; Stefaniakowa, A.; Tropilo, J.; Stanczak, B.; Peconek, J.; Mierzewska, H.; Bielecka, J. (Szkola Glowna Gospodarstwa Wiejskiego, Warsaw (Poland). Katedra Higieny Produktow Zwierzecych)

    1979-01-01

    The influence of x-radiation on thermoresistance of bacteria was determined. The studies were carried out on: E. coli, Pr. vulgaris, S. typhimurium, Staph. aureus and Str. faecalis. The bacteria were irradiated in PBS (physiological buffer solution) and in broth (containing about 1% of protein) with x-rays at radium absorbed doses of 100, 1000, 5000 and 10 000, which was followed immediately by heating at temperatures causing death of part of the bacteria. The results obtained indicate that irradiation of bacteria with small x-ray doses distinctly decreases their thermoresistance. Synergetic action of irradiation and heating of bacteria was observed, increasing with increased irradiation dose. The greatest changes of thermoresistance occurred with Pr. vulgaris, the smallest with S. typhimurium. Thermoresistance of bacteria decreased more strongly on their irradiation in protein-free medium (PBS).

  17. Influence of irradiation of bacteria on their thermoresistance

    International Nuclear Information System (INIS)

    Szulc, M.; Stefaniakowa, A.; Tropilo, J.; Stanczak, B.; Peconek, J.; Mierzewska, H.; Bielecka, J.

    1979-01-01

    The influence of x-radiation on thermoresistance of bacteria was determined. The studies were carried out on: E. coli, Pr. vulgaris, S. typhimurium, Staph. aureus and Str. faecalis. The bacteria were irradiated in PBS (physiological buffer solution) and in broth (containing about 1% of protein) with x-rays at radium absorbed doses of 100, 1000, 5000 and 10 000, which was followed immediately by heating at temperatures causing death of part of the bacteria. The results obtained indicate that irradiation of bacteria with small x-ray doses distinctly decreases their thermoresistance. Synergetic action of irradiation and heating of bacteria was observed, increasing with increased irradiation dose. The greatest changes of thermoresistance occurred with Pr. vulgaris, the smallest with S. typhimurium. Thermoresistance of bacteria decreased more strongly on their irradiation in protein-free medium (PBS). (author)

  18. Study of hydrogen producing bacteria in anaerobic digester

    Energy Technology Data Exchange (ETDEWEB)

    Kexin, L.; Jieguan, X.; Duoqun, L.; Guochao, S.; Tingjie, S.

    1980-01-01

    Hydrogen was produced vigorously by adding tuber mill of Dioscorea zingiberensis to enrich a culture of biogas sludge. Hydrogen-producig bacteria were able to be enriched in this way and twenty-four strains of hydrogen-producing bacteria were isolated. The amount of hydrogen produced varied with the species of bacteria and the media used. These bacteria were identified as Enterobacter cloacae, Escherichia coli, Serratia marcescens, Citrobacter freudii, Hafina alvei and Clostridium acetobutylicum. E. cloacae may be the major component. Its relative number was about 58.3% of the total number of bacteria isolated, and S. marcescens, about 16.7% and C. acetobutylicum, about 12.5%. The methane content in the biogas was greatly increased by adding a mixed culture of hydrogen-producing bacteria to an enriched culture of biogas sludge. The carbon dioxide content in it was obviously reduced. 8 references.

  19. 9th International Symposium on Lactic Acid Bacteria

    OpenAIRE

    Kuipers, Oscar P.; Poolman, Berend; Hugenholtz, Jeroen

    2008-01-01

    What’s new in the field of lactic acid bacteria? The 9th International Symposium on Lactic Acid Bacteria (LAB9) will take place 31 August to 4 September 2008 in Egmond aan Zee, The Netherlands. Traditionally, the triannual LAB symposium focuses on the themes of genetics, physiology, and applications of lactic acid bacteria (LAB). These microorganisms are widely used in the food industry but are also increasingly applied as probiotics, enzyme and metabolite factories, and vaccine delivery vehi...

  20. Antimutagenicity of fermented milk with lactic acid bacteria

    OpenAIRE

    細野, 明義; Akiyoshi, Hosono; 信州大学大学院農学研究科; Graduate School of Agriculture, Shinshu University

    2002-01-01

    Fermented milk and lactic acid bacteria have been considered to provide potential health benefits to human beings. Milk containing casein has been shown to be highly antimutagenic, and fermentation by lactic acid bacteria produces various hydrolytic peptides which contribute to the high antimutagenicity of fermented milk. The antimutagenic property of fermented milk was dependent on the strains of lactic acid bacteria and the fermentation time. Not only the proteolytic products of casein, but...

  1. Transmission of Nephridial Bacteria of the Earthworm Eisenia fetida

    OpenAIRE

    Davidson, Seana K.; Stahl, David A.

    2006-01-01

    The lumbricid earthworms (annelid family Lumbricidae) harbor gram-negative bacteria in their excretory organs, the nephridia. Comparative 16S rRNA gene sequencing of bacteria associated with the nephridia of several earthworm species has shown that each species of worm harbors a distinct bacterial species and that the bacteria from different species form a monophyletic cluster within the genus Acidovorax, suggesting that there is a specific association resulting from radiation from a common b...

  2. Antibiotic-resistant soil bacteria in transgenic plant fields

    OpenAIRE

    Demaneche, S.; Sanguin, H.; Pote, J.; Navarro, Elisabeth; Bernillon, D.; Mavingui, P.; Wildi, W.; Vogel, T. M.; Simonet, P.

    2008-01-01

    Understanding the prevalence and polymorphism of antibiotic resistance genes in soil bacteria and their potential to be transferred horizontally is required to evaluate the likelihood and ecological (and possibly clinical) consequences of the transfer of these genes from transgenic plants to soil bacteria. In this study, we combined culture-dependent and -independent approaches to study the prevalence and diversity of bla genes in soil bacteria and the potential impact that a 10-successive-y...

  3. Distribution and Identification of Luminous Bacteria from the Sargasso Sea

    OpenAIRE

    Orndorff, S. A.; Colwell, R. R.

    1980-01-01

    Vibrio fischeri and Lucibacterium harveyi constituted 75 of the 83 luminous bacteria isolated from Sargasso Sea surface waters. Photobacterium leiognathi and Photobacterium phosphoreum constituted the remainder of the isolates. Luminescent bacteria were recovered at concentrations of 1 to 63 cells per 100 ml from water samples collected at depths of 160 to 320 m. Two water samples collected at the thermocline yielded larger numbers of viable, aerobic heterotrophic and luminous bacteria. Lumin...

  4. Bacteria resitnce to antibiotics: an analysis of hospital conduct

    OpenAIRE

    Oliveira, Andrea Luiza de; CESUMAR

    2007-01-01

    The objective of this paper is to identify the main medical-hospital practices that aggravate bacteria resistance and reflect the indiscriminate use of antibiotics leaging to hospital infections. To that aim, we present general concepts on antibiotic therapy. We analyse the development of induced bacteria resistance by the indiscriminate use of antibiotics, describing the genetic and biochemical resistance mechanisms. We focus on the incidence of bacteria resistance in hospital in relation to...

  5. Synthesis of Metal Nanoparticles by Bacteria

    Directory of Open Access Journals (Sweden)

    Fikriye Alev Akçay

    2018-04-01

    Full Text Available Metal particles reduced to nano size by nanotechnological methods are confronted in many different fields such as biomedical and physicochemical, pharmaceutical, electric-electronic, automotive and food industries. Nanoparticles can be produced using chemical, physical and biological methods, of which chemical processes are in common use. However, physical and chemical methods are not environmentally friendly and economical because they require the use of high temperature, high pressure and toxic chemicals. For this reason, interest in the production of metal nanoparticles by biological methods, also called green technology, an environmentally friendly and sustainable approach, has increased in recent years. With some plant extracts and intracellular and extracellular secretions of microorganisms, some reduction reactions take place and metal nanoparticles are produced. Bacteria have been actively involved in nanotechnology in recent years due to their diversity in nature, their ease of isolation, and ease of nanoparticle synthesis. In this article, production and application of metal nanoparticles by using bacterial methods have been reviewed.

  6. Acetic Acid Bacteria as Symbionts of Insects

    KAUST Repository

    Crotti, Elena

    2016-06-14

    Acetic acid bacteria (AAB) are being increasingly described as associating with different insect species that rely on sugar-based diets. AAB have been found in several insect orders, among them Diptera, Hemiptera, and Hymenoptera, including several vectors of plant, animal, and human diseases. AAB have been shown to associate with the epithelia of different organs of the host, they are able to move within the insect’s body and to be transmitted horizontally and vertically. Here, we review the ecology of AAB and examine their relationships with different insect models including mosquitoes, leafhoppers, and honey bees. We also discuss the potential use of AAB in symbiont-based control strategies, such as “Trojan-horse” agents, to block the transmission of vector-borne diseases.

  7. Mutagenic effects of heavy ions in bacteria

    Science.gov (United States)

    Horneck, G.; Krasavin, E. A.; Kozubek, S.

    1994-10-01

    Various mutagenic effects by heavy ions were studied in bacteria, irradiated at accelerators in Dubna, Prague, Berkeley or Darmstadt. Endpoints investigated are histidine reversion (B. subtilis, S. typhimurium), azide resistance (B. subtilis), mutation in the lactose operon (E. coli), SOS chromotest (E. coli) and λ-prophage induction (E. coli). It was found that the cross sections of the different endpoints show a similar dependence on energy. For light ions (Z = 26) it increases with energy up to a maximum or saturation. The increment becomes steeper with increasing Z. This dependence on energy suggests a ``mutagenic belt'' inside the track that is restricted to an area where the density of departed energy is low enough not to kill the cell, but high enough to induce mutations.

  8. Separation of pathogenic bacteria by chain length.

    Science.gov (United States)

    Beech, Jason P; Ho, Bao Dang; Garriss, Geneviève; Oliveira, Vitor; Henriques-Normark, Birgitta; Tegenfeldt, Jonas O

    2018-02-13

    Using Deterministic Lateral Displacement devices optimized for sensitivity to particle length, we separate subpopulations of bacteria depending on known properties that affect their capability to cause disease (virulence). For the human bacterial pathogen Streptococcus pneumoniae, bacterial chain length and the presence of a capsule are known virulence factors contributing to its ability to cause severe disease. Separation of cultured pneumococci into subpopulations based on morphological type (single cocci, diplococci and chains) will enable more detailed studies of the role they play in virulence. Moreover, we present separation of mixed populations of almost genetically identical encapsulated and non-encapsulated pneumococcal strains in our device. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  9. Biological Potential of Chitinolytic Marine Bacteria

    Directory of Open Access Journals (Sweden)

    Sara Skøtt Paulsen

    2016-12-01

    Full Text Available Chitinolytic microorganisms secrete a range of chitin modifying enzymes, which can be exploited for production of chitin derived products or as fungal or pest control agents. Here, we explored the potential of 11 marine bacteria (Pseudoalteromonadaceae, Vibrionaceae for chitin degradation using in silico and phenotypic assays. Of 10 chitinolytic strains, three strains, Photobacterium galatheae S2753, Pseudoalteromonas piscicida S2040 and S2724, produced large clearing zones on chitin plates. All strains were antifungal, but against different fungal targets. One strain, Pseudoalteromonas piscicida S2040, had a pronounced antifungal activity against all seven fungal strains. There was no correlation between the number of chitin modifying enzymes as found by genome mining and the chitin degrading activity as measured by size of clearing zones on chitin agar. Based on in silico and in vitro analyses, we cloned and expressed two ChiA-like chitinases from the two most potent candidates to exemplify the industrial potential.

  10. Biological Potential of Chitinolytic Marine Bacteria.

    Science.gov (United States)

    Paulsen, Sara Skøtt; Andersen, Birgitte; Gram, Lone; Machado, Henrique

    2016-12-16

    Chitinolytic microorganisms secrete a range of chitin modifying enzymes, which can be exploited for production of chitin derived products or as fungal or pest control agents. Here, we explored the potential of 11 marine bacteria ( Pseudoalteromonadaceae , Vibrionaceae ) for chitin degradation using in silico and phenotypic assays. Of 10 chitinolytic strains, three strains, Photobacterium galatheae S2753, Pseudoalteromonas piscicida S2040 and S2724, produced large clearing zones on chitin plates. All strains were antifungal, but against different fungal targets. One strain, Pseudoalteromonas piscicida S2040, had a pronounced antifungal activity against all seven fungal strains. There was no correlation between the number of chitin modifying enzymes as found by genome mining and the chitin degrading activity as measured by size of clearing zones on chitin agar. Based on in silico and in vitro analyses, we cloned and expressed two ChiA-like chitinases from the two most potent candidates to exemplify the industrial potential.

  11. Physical mode of bacteria and virus coevolution

    Science.gov (United States)

    Han, Pu; Niestemski, Liang; Deem, Michael

    2013-03-01

    Single-cell hosts such as bacteria or archaea possess an adaptive, heritable immune system that protects them from viral invasion. This system, known as the CRISPR-Cas system, allows the host to recognize and incorporate short foreign DNA or RNA sequences from viruses or plasmids. The sequences form what are called ``spacers'' in the CRISPR. Spacers in the CRISPR loci provide a record of the host and predator coevolution history. We develop a physical model to study the dynamics of this coevolution due to immune pressure. Hosts and viruses reproduce, die, and evolve due to viral infection pressure, host immune pressure, and mutation. We will discuss the differing effects of point mutation and recombination on CRISPR evolution. We will also discuss the effect of different spacer deletion mechanisms. We will describe population structure of hosts and viruses, how spacer diversity depends on position within CRISPR, and match of the CRISPR spacers to the virus population.

  12. Magnetotactic bacteria. Promising biosorbents for heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Wei; Zhang, Yanzong; Ding, Xiaohui; Liu, Yan; Shen, Fei; Zhang, Xiaohong; Deng, Shihuai; Xiao, Hong; Yang, Gang; Peng, Hong [Sichuan Agricultural Univ., Chengdu (China). Provincial Key Lab. of Agricultural Environmental Engineering

    2012-09-15

    Magnetotactic bacteria (MTB), which can orient and migrate along a magnetic line of force due to intracellular nanosized magnetosomes, have been a subject of research in the medical field, in dating environmental changes, and in environmental remediation. This paper reviews the recent development of MTB as biosorbents for heavy metals. Ultrastructures and taxis of MTB are investigated. Adsorptions in systems of unitary and binary ions are highlighted, as well as adsorption conditions (temperature, pH value, biomass concentration, and pretreatments). The separation and desorption of MTB in magnetic separators are also discussed. A green method to produce metal nanoparticles is provided, and an energy-efficient way to recover precious metals is put forward during biosorption. (orig.)

  13. Streptomyces bacteria as potential probiotics in aquaculture

    Directory of Open Access Journals (Sweden)

    Tan Loh eTeng Hern

    2016-02-01

    Full Text Available In response to the increased seafood demand from the ever-going human population, aquaculture has become the fastest growing animal food-producing sector. However, the indiscriminate use of antibiotics as a biological control agents for fish pathogens has led to the emergence of antibiotic resistance bacteria. Probiotics are defined as living microbial supplement that exert beneficial effects on hosts as well as improvement of environmental parameters. Probiotics have been proven to be effective in improving the growth, survival and health status of the aquatic livestock. This review aims to highlight the genus Streptomyces can be a good candidate for probiotics in aquaculture. Studies showed that the feed supplemented with Streptomyces could protect fish and shrimp from pathogens as well as increase the growth of the aquatic organisms. Furthermore, the limitations of Streptomyces as probiotics in aquaculture is also highlighted and solutions are discussed to these limitations.

  14. DEOXYRIBONUCLEIC ACID HYBRIDS OF ACETIC ACID BACTERIA

    Science.gov (United States)

    De Ley, J.; Friedman, S.

    1964-01-01

    De Ley, J. (State University, Ghent, Belgium), and S. Friedman. Deoxyribonucleic acid hybrids of acetic acid bacteria. J. Bacteriol. 88:937–945. 1964.—Deuterated N15-labeled deoxyribonucleic acid (DNA) from Acetobacter aceti (mesoxydans 4) forms hybrids with ordinary DNA from other species of this genus (A. xylinum, A. pasteurianus, A. estunensis, and possibly A. xylinoides) when the guanine plus cytosine base composition does not vary by more than 1 to 2%. Beyond this limit (A. aceti Ch31 and A. muciparus 5) no hybrids are formed. The hybrids are apparently derived from an asymmetrical part of the compositional distribution. The results lend strength to the concept of a genetic species rather than to a division of a genus into sharply separated species, based on small phenotypic differences. Taxonomic implications are discussed. PMID:14219057

  15. Degradation of multiwall carbon nanotubes by bacteria

    International Nuclear Information System (INIS)

    Zhang, Liwen; Petersen, Elijah J.; Habteselassie, Mussie Y.; Mao, Liang; Huang, Qingguo

    2013-01-01

    Understanding the environmental transformation of multiwall carbon nanotubes (MWCNTs) is important to their life cycle assessment and potential environmental impacts. We report that a bacterial community is capable of degrading 14 C-labeled MWCNTs into 14 CO 2 in the presence of an external carbon source via co-metabolism. Multiple intermediate products were detected, and genotypic characterization revealed three possible microbial degraders: Burkholderia kururiensis, Delftia acidovorans, and Stenotrophomonas maltophilia. This result suggests that microbe/MWCNTs interaction may impact the long-term fate of MWCNTs. Highlights: •Mineralization of MWCNTs by a bacterial community was observed. •The mineralization required an external carbon source. •Multiple intermediate products were identified in the MWCNT degrading culture. •Three bacterial species were found likely responsible for MWCNT degradation. -- The 14 C-labeled multiwall carbon nanotubes can be degraded to 14 CO 2 and other byproducts by a bacteria community under natural conditions

  16. Phosphate Solubilizing Bacteria Adaptive to Vinasse

    Directory of Open Access Journals (Sweden)

    Kahar Muzakhar

    2015-06-01

    Full Text Available Microorganisms identified as phosphate solubilizing bacteria (PSB adaptive to vinasse were successfully screened from sugarcane soil from an agriculatural estate in Jatiroto. By conducting a screening on Pikovskaya’s agar medium (PAM, we found that five different isolates were detected as PSB (pvk-5a, pvk-5b, pvk-6b, pvk-7a, and pvk-8a. Of the five isolates only three could be grown and were found to be adaptive to vinasse based medium without any nutrients added (pvk-5a, pvk-5b and pvk-7a. The three isolates were characterized as coccus and Gram negative with no endospores detected. We suggest that these three isolates can be used as biofertilizer agent to support organic farming.

  17. Extracellular polysaccharides produced by marine bacteria.

    Science.gov (United States)

    Manivasagan, Panchanathan; Kim, Se-Kwon

    2014-01-01

    Extracellular polysaccharides (EPSs) produced by microorganisms are a complex mixture of biopolymers primarily consisting of polysaccharides, as well as proteins, nucleic acids, lipids, and humic substances. Microbial polysaccharides are multifunctional and can be divided into intracellular polysaccharides, structural polysaccharides, and extracellular polysaccharides or exopolysaccharides. Recent advances in biological techniques allow high levels of polysaccharides of interest to be produced in vitro. Biotechnology is a powerful tool to obtain polysaccharides from a variety of marine microorganisms, by controlling the growth conditions in a bioreactor while tailoring the production of biologically active compounds. The aim of this chapter is to give an overview of current knowledge on extracellular polysaccharides producing marine bacteria isolated from marine environment. © 2014 Elsevier Inc. All rights reserved.

  18. [Bacteria and biofilm in respiratory tract infections].

    Science.gov (United States)

    Drago, Lorenzo

    2009-07-01

    Biofilm is a structured community of bacterial cells included in a self-produced polymeric matrix adherent to an inert or living surface. The main property of biofilm consists of making microrganisms more resistant to exogenous insults. Antibiotic therapy typically resolves symptoms determined by planktonic cells released by biofilms but is not able to eradicate and completely clear biofilm. This is why infections sustained by biofilm-producer bacteria are often recurrent, making mandatory repeated antibiotic treatments. The typical conformation of biofilm, the phenotypical and genetical features existing among the different microrganisms confer a natural resistance to a number of antimicrobials so that it is necessary to test antimicrobial activity against the microbial species itself and also against biofilm, when it is present. Comparative studies, performed on quinolones and beta-lactams, evidenced a significant activity against biofilm produced by pneumococci, haemophyli and pseudomonas as well.

  19. REGEN: Ancestral Genome Reconstruction for Bacteria

    Directory of Open Access Journals (Sweden)

    João C. Setubal

    2012-07-01

    Full Text Available Ancestral genome reconstruction can be understood as a phylogenetic study with more details than a traditional phylogenetic tree reconstruction. We present a new computational system called REGEN for ancestral bacterial genome reconstruction at both the gene and replicon levels. REGEN reconstructs gene content, contiguous gene runs, and replicon structure for each ancestral genome. Along each branch of the phylogenetic tree, REGEN infers evolutionary events, including gene creation and deletion and replicon fission and fusion. The reconstruction can be performed by either a maximum parsimony or a maximum likelihood method. Gene content reconstruction is based on the concept of neighboring gene pairs. REGEN was designed to be used with any set of genomes that are sufficiently related, which will usually be the case for bacteria within the same taxonomic order. We evaluated REGEN using simulated genomes and genomes in the Rhizobiales order.

  20. REGEN: Ancestral Genome Reconstruction for Bacteria.

    Science.gov (United States)

    Yang, Kuan; Heath, Lenwood S; Setubal, João C

    2012-07-18

    Ancestral genome reconstruction can be understood as a phylogenetic study with more details than a traditional phylogenetic tree reconstruction. We present a new computational system called REGEN for ancestral bacterial genome reconstruction at both the gene and replicon levels. REGEN reconstructs gene content, contiguous gene runs, and replicon structure for each ancestral genome. Along each branch of the phylogenetic tree, REGEN infers evolutionary events, including gene creation and deletion and replicon fission and fusion. The reconstruction can be performed by either a maximum parsimony or a maximum likelihood method. Gene content reconstruction is based on the concept of neighboring gene pairs. REGEN was designed to be used with any set of genomes that are sufficiently related, which will usually be the case for bacteria within the same taxonomic order. We evaluated REGEN using simulated genomes and genomes in the Rhizobiales order.

  1. Antimicrobial resistant bacteria in the food chain

    DEFF Research Database (Denmark)

    Wegener, Henrik Caspar

    2003-01-01

    Antimicrobials are used for treatment and prevention of disease in food animals and as feed additives for growth promotion. All uses lead to the development of resistant bacteria, some of which are pathogenic to humans. Current main concerns are with resistance in Salmonella and Campylobacter...... to fluoroquinolones, which are used for empirical treatment of diarrhea in humans. Resistance to vancomycin and Synercid((R)) in enterococci is associated with use of similar drugs as growth promoters in food animals. Danish food animal producers have terminated the use of antimicrobial growth promoters. This has...... reduced the total use of antimicrobials by more than 50% and markedly reduced levels of resistance. There is an urgent need to implement globally, WHO principles for prudent use of antimicrobials in food animals. Use of antimicrobials as growth promoters could and should be terminated completely....

  2. Laser-induced fluorescence imaging of bacteria

    Science.gov (United States)

    Hilton, Peter J.

    1998-12-01

    This paper outlines a method for optically detecting bacteria on various backgrounds, such as meat, by imaging their laser induced auto-fluorescence response. This method can potentially operate in real-time, which is many times faster than current bacterial detection methods, which require culturing of bacterial samples. This paper describes the imaging technique employed whereby a laser spot is scanned across an object while capturing, filtering, and digitizing the returned light. Preliminary results of the bacterial auto-fluorescence are reported and plans for future research are discussed. The results to date are encouraging with six of the eight bacterial strains investigated exhibiting auto-fluorescence when excited at 488 nm. Discrimination of these bacterial strains against red meat is shown and techniques for reducing background fluorescence discussed.

  3. [Antimicrobial susceptibility testing of anaerobic bacteria].

    Science.gov (United States)

    García-Sánchez, José E; García-Sánchez, Enrique; García-García, María Inmaculada

    2014-02-01

    The anaerobic bacteria resistance to antibiotics is increasing, and even has appeared against the most active of those, like metronidazol and carbapenems. This fact forces to make and periodical sensibility tests -at least in the most aggressive and virulent species, in cases that they are isolated from life locations and in the absence of therapeutic response- to check the local sensibility and to establish suitable empiric therapies, all based on multicentric studies carried out in order to this or well to check the activity of new antibiotics. For the laboratory routine, the easiest sensibility method is the E-test/MIC evaluator. Another alternative is microdilution, that's only normalized for Bacteroides. There are preliminary facts that allow the use of disc diffusion method in some species of Bacteroides and Clostridium. For the temporal and multicentric studies, the procedure is dilution in agar plate, the reference method. Copyright © 2014 Elsevier España, S.L. All rights reserved.

  4. Streptomyces Bacteria as Potential Probiotics in Aquaculture.

    Science.gov (United States)

    Tan, Loh Teng-Hern; Chan, Kok-Gan; Lee, Learn-Han; Goh, Bey-Hing

    2016-01-01

    In response to the increased seafood demand from the ever-going human population, aquaculture has become the fastest growing animal food-producing sector. However, the indiscriminate use of antibiotics as a biological control agents for fish pathogens has led to the emergence of antibiotic resistance bacteria. Probiotics are defined as living microbial supplement that exert beneficial effects on hosts as well as improvement of environmental parameters. Probiotics have been proven to be effective in improving the growth, survival and health status of the aquatic livestock. This review aims to highlight the genus Streptomyces can be a good candidate for probiotics in aquaculture. Studies showed that the feed supplemented with Streptomyces could protect fish and shrimp from pathogens as well as increase the growth of the aquatic organisms. Furthermore, the limitations of Streptomyces as probiotics in aquaculture is also highlighted and solutions are discussed to these limitations.

  5. [Metabolism of mangiferin by human intestinal bacteria in vitro].

    Science.gov (United States)

    Huang, Huixue; Tan, Zhenyuan; Deng, Jiagang; Liang, Qiuyun; Nong, Yumei; Song, Nianmei

    2011-02-01

    To study the metabolism of mangiferin by human intestinal bacteria in vitro. Human intestinal bacteria and mangiferin were incubated under anaerobic conditions in vitro. The metabolite was separated and purified by D101 macroporous resin column and preparation high performance liquid chromatography, and its structure was identified by MS and NMR. After 12 h incubation with human intestinal bacteria, the content of mangiferin metabolite reached the maximum, and it was determined as 1, 3, 6, 7-tetrahydroxyxanthen by MS and NMR. Mangiferin can be metabolized in vitro by human intestinal bacteria into its aglycone (1, 3, 6, 7-tetrahydroxyxanthen).

  6. Identification of subdominant lactic acid bacteria in dawadawa (a ...

    African Journals Online (AJOL)

    ) by lactic acid bacteria (LAB) was investigated for seven days. The LAB isolated were Pediococcus pentosaceus, Lactobacillus raffinolactus, Leuconostoc mesenteroides, Leuconostoc sp, Pediococcus halophilus, Pediococcus sp ...

  7. Investigation of IR absorption spectra of oral cavity bacteria

    Science.gov (United States)

    Belikov, Andrei V.; Altshuler, Gregory B.; Moroz, Boris T.; Pavlovskaya, Irina V.

    1996-12-01

    The results of comparative investigation for IR and visual absorption spectra of oral cavity bacteria are represented by this paper. There are also shown the main differences in absorption spectra of such pure bacteria cultures as : E- coli, Candida, Staph, Epidermidis, and absorption spectra of bacteria colonies cultured in tooth root canals suspected to harbour several endodontical problems. The results of experimental research targeted to investigate an effect of such combined YAG:Nd and YAG:Cr; Tm; Ho laser parameters like: wavelength, energy density, average power and etc., to oral cavity bacteria deactivation are given finally.

  8. Quantification and qualification of bacteria trapped in chewed gum.

    Directory of Open Access Journals (Sweden)

    Stefan W Wessel

    Full Text Available Chewing of gum contributes to the maintenance of oral health. Many oral diseases, including caries and periodontal disease, are caused by bacteria. However, it is unknown whether chewing of gum can remove bacteria from the oral cavity. Here, we hypothesize that chewing of gum can trap bacteria and remove them from the oral cavity. To test this hypothesis, we developed two methods to quantify numbers of bacteria trapped in chewed gum. In the first method, known numbers of bacteria were finger-chewed into gum and chewed gums were molded to standard dimensions, sonicated and plated to determine numbers of colony-forming-units incorporated, yielding calibration curves of colony-forming-units retrieved versus finger-chewed in. In a second method, calibration curves were created by finger-chewing known numbers of bacteria into gum and subsequently dissolving the gum in a mixture of chloroform and tris-ethylenediaminetetraacetic-acid (TE-buffer. The TE-buffer was analyzed using quantitative Polymerase-Chain-Reaction (qPCR, yielding calibration curves of total numbers of bacteria versus finger-chewed in. Next, five volunteers were requested to chew gum up to 10 min after which numbers of colony-forming-units and total numbers of bacteria trapped in chewed gum were determined using the above methods. The qPCR method, involving both dead and live bacteria yielded higher numbers of retrieved bacteria than plating, involving only viable bacteria. Numbers of trapped bacteria were maximal during initial chewing after which a slow decrease over time up to 10 min was observed. Around 10(8 bacteria were detected per gum piece depending on the method and gum considered. The number of species trapped in chewed gum increased with chewing time. Trapped bacteria were clearly visualized in chewed gum using scanning-electron-microscopy. Summarizing, using novel methods to quantify and qualify oral bacteria trapped in chewed gum, the hypothesis is confirmed that chewing

  9. Biodegradation of endosulfan by mixed bacteria culture strains of ...

    African Journals Online (AJOL)

    Biodegradation of endosulfan by mixed bacteria culture strains of Pseudomonas aeruginosa and Staphylococcus aureus. Nsidibeabasi Calvin Nwokem, Calvin Onyedika Nwokem, Casmir Emmanuel Gimba, Beatrice Nkiruka Iwuala ...

  10. Evaluation of organophosphorus pesticide biodegradation by halophilic bacteria

    Directory of Open Access Journals (Sweden)

    Shokufeh Rafieyan

    2018-03-01

    Discussion and conclusion: Halophilic bacteria due to compatibility with the salty condition, can be a good option for the removal of organophosphorus pesticides in the contaminated salty environments.

  11. Effect of radiation on activity of sulphate reducing bacteria

    International Nuclear Information System (INIS)

    Agaev, N.M.; Smorodin, A.E.; Gusejnov, M.M.

    1985-01-01

    The effect of γ-radiation on activity of sulphate reducing bacteria has been studied. Concentration of biogenic hydrogen, generated in the medium, is the main criterion, characterizing corrosion activity of the bacteria studied. The developed method of suppression of active development of sulfate reducing bacteria considerably reduces, and at lethal doses of γ-radiation eliminates altogether the bacteria activity and formation of the main corrosion agent-hydrogen sulphide-in the medium and that, in its turn, liquidates hydrogen sulphide corrosion

  12. Diversity of rumen bacteria in canadian cervids.

    Directory of Open Access Journals (Sweden)

    Robert J Gruninger

    Full Text Available Interest in the bacteria responsible for the breakdown of lignocellulosic feedstuffs within the rumen has increased due to their potential utility in industrial applications. To date, most studies have focused on bacteria from domesticated ruminants. We have expanded the knowledge of the microbial ecology of ruminants by examining the bacterial populations found in the rumen of non-domesticated ruminants found in Canada. Next-generation sequencing of 16S rDNA was employed to characterize the liquid and solid-associated bacterial communities in the rumen of elk (Cervus canadensis, and white tailed deer (Odocoileus virginianus. Despite variability in the microbial populations between animals, principle component and weighted UniFrac analysis indicated that bacterial communities in the rumen of elk and white tail deer are distinct. Populations clustered according to individual host animal and not the association with liquid or solid phase of the rumen contents. In all instances, Bacteroidetes and Firmicutes were the dominant bacterial phyla, although the relative abundance of these differed among ruminant species and between phases of rumen digesta, respectively. In the elk samples Bacteroidetes were more predominant in the liquid phase whereas Firmicutes was the most prevalent phyla in the solid digesta (P = 1×10(-5. There were also statistically significant differences in the abundance of OTUs classified as Fibrobacteres (P = 5×10(-3 and Spirochaetes (P = 3×10(-4 in the solid digesta of the elk samples. We identified a number of OTUs that were classified as phylotypes not previously observed in the rumen environment. Our results suggest that although the bacterial diversity in wild North American ruminants shows overall similarities to domesticated ruminants, we observed a number of OTUs not previously described. Previous studies primarily focusing on domesticated ruminants do not fully represent the microbial diversity of the

  13. Mechanism of gram variability in select bacteria.

    Science.gov (United States)

    Beveridge, T J

    1990-03-01

    Gram stains were performed on strains of Actinomyces bovis, Actinomyces viscosus, Arthrobacter globiformis, Bacillus brevis, Butyrivibrio fibrisolvens, Clostridium tetani, Clostridium thermosaccharolyticum, Corynebacterium parvum, Mycobacterium phlei, and Propionibacterium acnes, using a modified Gram regimen that allowed the staining process to be observed by electron microscopy (J. A. Davies, G. K. Anderson, T. J. Beveridge, and H. C. Clark, J. Bacteriol. 156:837-845, 1983). Furthermore, since a platinum salt replaced the iodine mordant of the Gram stain, energy-dispersive X-ray spectroscopy could evaluate the stain intensity and location by monitoring the platinum signal. These gram-variable bacteria could be split into two groups on the basis of their staining responses. In the Actinomyces-Arthrobacter-Corynebacterium-Mycobacterium-Propionibacterium group, few cells became gram negative until the exponential growth phase; by mid-exponential phase, 10 to 30% of the cells were gram negative. The cells that became gram negative were a select population of the culture, had initiated septum formation, and were more fragile to the stress of the Gram stain at the division site. As cultures aged to stationary phase, there was a relatively slight increase toward gram negativity (now 15 to 40%) due to the increased lysis of nondividing cells by means of lesions in the side walls; these cells maintained their rod shape but stained gram negative. Those in the Bacillus-Butyrivibrio-Clostridium group also became gram negative as cultures aged but by a separate set of events. These bacteria possessed more complex walls, since they were covered by an S layer. They stained gram positive during lag and the initial exponential growth phases, but as doubling times increased, the wall fabric underlying the S layer became noticeably thinner and diffuse, and the cells became more fragile to the Gram stain. By stationary phase, these cultures were virtually gram negative.

  14. Stress Physiology of Lactic Acid Bacteria.

    Science.gov (United States)

    Papadimitriou, Konstantinos; Alegría, Ángel; Bron, Peter A; de Angelis, Maria; Gobbetti, Marco; Kleerebezem, Michiel; Lemos, José A; Linares, Daniel M; Ross, Paul; Stanton, Catherine; Turroni, Francesca; van Sinderen, Douwe; Varmanen, Pekka; Ventura, Marco; Zúñiga, Manuel; Tsakalidou, Effie; Kok, Jan

    2016-09-01

    Lactic acid bacteria (LAB) are important starter, commensal, or pathogenic microorganisms. The stress physiology of LAB has been studied in depth for over 2 decades, fueled mostly by the technological implications of LAB robustness in the food industry. Survival of probiotic LAB in the host and the potential relatedness of LAB virulence to their stress resilience have intensified interest in the field. Thus, a wealth of information concerning stress responses exists today for strains as diverse as starter (e.g., Lactococcus lactis), probiotic (e.g., several Lactobacillus spp.), and pathogenic (e.g., Enterococcus and Streptococcus spp.) LAB. Here we present the state of the art for LAB stress behavior. We describe the multitude of stresses that LAB are confronted with, and we present the experimental context used to study the stress responses of LAB, focusing on adaptation, habituation, and cross-protection as well as on self-induced multistress resistance in stationary phase, biofilms, and dormancy. We also consider stress responses at the population and single-cell levels. Subsequently, we concentrate on the stress defense mechanisms that have been reported to date, grouping them according to their direct participation in preserving cell energy, defending macromolecules, and protecting the cell envelope. Stress-induced responses of probiotic LAB and commensal/pathogenic LAB are highlighted separately due to the complexity of the peculiar multistress conditions to which these bacteria are subjected in their hosts. Induction of prophages under environmental stresses is then discussed. Finally, we present systems-based strategies to characterize the "stressome" of LAB and to engineer new food-related and probiotic LAB with improved stress tolerance. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  15. Stress Physiology of Lactic Acid Bacteria

    Science.gov (United States)

    Papadimitriou, Konstantinos; Alegría, Ángel; Bron, Peter A.; de Angelis, Maria; Gobbetti, Marco; Kleerebezem, Michiel; Lemos, José A.; Linares, Daniel M.; Ross, Paul; Stanton, Catherine; Turroni, Francesca; van Sinderen, Douwe; Varmanen, Pekka; Ventura, Marco; Zúñiga, Manuel; Tsakalidou, Effie

    2016-01-01

    SUMMARY Lactic acid bacteria (LAB) are important starter, commensal, or pathogenic microorganisms. The stress physiology of LAB has been studied in depth for over 2 decades, fueled mostly by the technological implications of LAB robustness in the food industry. Survival of probiotic LAB in the host and the potential relatedness of LAB virulence to their stress resilience have intensified interest in the field. Thus, a wealth of information concerning stress responses exists today for strains as diverse as starter (e.g., Lactococcus lactis), probiotic (e.g., several Lactobacillus spp.), and pathogenic (e.g., Enterococcus and Streptococcus spp.) LAB. Here we present the state of the art for LAB stress behavior. We describe the multitude of stresses that LAB are confronted with, and we present the experimental context used to study the stress responses of LAB, focusing on adaptation, habituation, and cross-protection as well as on self-induced multistress resistance in stationary phase, biofilms, and dormancy. We also consider stress responses at the population and single-cell levels. Subsequently, we concentrate on the stress defense mechanisms that have been reported to date, grouping them according to their direct participation in preserving cell energy, defending macromolecules, and protecting the cell envelope. Stress-induced responses of probiotic LAB and commensal/pathogenic LAB are highlighted separately due to the complexity of the peculiar multistress conditions to which these bacteria are subjected in their hosts. Induction of prophages under environmental stresses is then discussed. Finally, we present systems-based strategies to characterize the “stressome” of LAB and to engineer new food-related and probiotic LAB with improved stress tolerance. PMID:27466284

  16. Growth of bacteria in 3-d colonies.

    Directory of Open Access Journals (Sweden)

    Xinxian Shao

    2017-07-01

    Full Text Available The dynamics of growth of bacterial populations has been extensively studied for planktonic cells in well-agitated liquid culture, in which all cells have equal access to nutrients. In the real world, bacteria are more likely to live in physically structured habitats as colonies, within which individual cells vary in their access to nutrients. The dynamics of bacterial growth in such conditions is poorly understood, and, unlike that for liquid culture, there is not a standard broadly used mathematical model for bacterial populations growing in colonies in three dimensions (3-d. By extending the classic Monod model of resource-limited population growth to allow for spatial heterogeneity in the bacterial access to nutrients, we develop a 3-d model of colonies, in which bacteria consume diffusing nutrients in their vicinity. By following the changes in density of E. coli in liquid and embedded in glucose-limited soft agar, we evaluate the fit of this model to experimental data. The model accounts for the experimentally observed presence of a sub-exponential, diffusion-limited growth regime in colonies, which is absent in liquid cultures. The model predicts and our experiments confirm that, as a consequence of inter-colony competition for the diffusing nutrients and of cell death, there is a non-monotonic relationship between total number of colonies within the habitat and the total number of individual cells in all of these colonies. This combined theoretical-experimental study reveals that, within 3-d colonies, E. coli cells are loosely packed, and colonies produce about 2.5 times as many cells as the liquid culture from the same amount of nutrients. We verify that this is because cells in liquid culture are larger than in colonies. Our model provides a baseline description of bacterial growth in 3-d, deviations from which can be used to identify phenotypic heterogeneities and inter-cellular interactions that further contribute to the structure of

  17. Enumeration of petroleum hydrocarbon utilizing bacteria

    International Nuclear Information System (INIS)

    Mukherjee, S.; Barot, M.; Levine, A.D.

    1996-01-01

    In-situ biological treatment is one among a number of emerging technologies that may be applied to the remediation of contaminated soils and groundwater. In 1985, a surface spill of 1,500 gallons of dielectric transformer oil at the Sandia National Laboratories (HERMES II facility) resulted in contamination of soil up to depths of 160 feet. The extent of contamination and site characteristics favored the application of in-situ bioremediation as a potential remedial technology. The purpose of this research was to enumerate indigenous microbial populations capable of degrading petroleum hydrocarbons. Microbial enumeration and characterization methods suitably adapted for hydrocarbon utilizing bacteria were used as an indicator of the presence of viable microbial consortia in excavated oil samples with hydrocarbon (TPH) concentrations ranging from 300 to 26,850 ppm. Microbial activity was quantified by direct and streak plating soil samples on silica gel media. Effects of toxicity and temperature were studied using batch cultures of hydrocarbon utilizing bacteria (selectively isolated in an enrichment medium), at temperatures of 20 and 35 C. It was concluded from this study that it is possible to isolate native microorganisms from contaminated soils from depths of 60 to 160 feet, and with oil concentration ranging from 300 to 26,850 ppm. About 62% of the microorganisms isolated form the contaminated soil were capable of using contaminant oil as a substrate for growth and metabolism under aerobic conditions. Growth rates were observed to be 50% higher for the highest contaminant concentration at 20 C. Resistance to toxicity to contaminant oil was also observed to be greater at 20 C than at 35 C

  18. Laserterapia e microcorrente na cicatrização de queimadura em ratos: terapias associadas ou isoladas? Laserterapia y microcorriente en la cicatrización de quemaduras en ratas: ¿terapias asociadas o aisladas? Low-level laser therapy and micro current in burn wound healing in rats: associated or isolated therapy?

    Directory of Open Access Journals (Sweden)

    Rodrigo Pegado de Abreu Freitas

    2013-03-01

    Full Text Available Este estudo teve o objetivo de investigar se há diferenças entre as terapias associadas e isoladas do laser e microcorrentes no reparo de lesão por queimadura em ratos. Um total de 40 animais foi dividido aleatoriamente em quatro grupos: grupo controle (GC; grupo microcorrente (GM, grupo laser (GL e grupo laser/microcorrente (GLM, tratados com laser associado a microcorrentes. Após lesões térmicas induzidas no dorso do animal, foi realizado um total de dez dias de tratamento. Amostras do tecido foram coletadas para estudo histopatológico semiquantitativo com Hematoxilina Eosina e Tricrômico de Masson. Foram utilizados os testes de Kruskal-Wallis e post-hoc de Dunn. Houve diferença significativa entre os grupos para a produção de fibroblastos (p=0,0003, colágeno (p=0,0153, neoangiogênese (p=0,0031 e anexos cutâneos (p=0,0004. Na análise histológica semiquantitativa, o GLM apresentou valores menores nos parâmetros histológicos de presença de colágeno, número de fibroblastos e anexos cutâneos (pEste estudio tiene el objetivo de investigar si hay diferencias entre las terapias asociadas y aisladas del láser y microcorrientes en la reparación de lesión por quemadura en ratas. Un total de 40 animales fueron divididos aleatoriamente en cuatro grupos: grupo control (GC, grupo microcorriente (GM, grupo láser (GL y grupo láser/microcorriente (GLM, tratados con láser asociado a microcorrientes. Después de inducidas las lesiones térmicas en el dorso del animal, fueron realizados en total diez días de tratamiento. Las muestras de tejido fueron recolectadas para el estudio histopatológico semicuantitativo usando Hematoxilina Eosina y Tricómico de Masson. Fueron utilizados los tests de Kruskal-Wallis y post-hoc de Dunn's. Hubo diferencia significativa entre los grupos para la producción de fibroblastos (p=0,0003, colágeno (p=0,0153, neoangiogénesis (p=0,0031 y anexos cutáneos (p=0,0004. En el análisis histol

  19. Ecophysiological strategies in response to UV-B radiation stress in cultures of temperate microalgae isolated from the Pacific coast of South America Estrategias ecofisiológicas en respuesta a la radiación ultravioleta-B en cultivos de microalgas templadas aisladas de la costa sudamericana del Pacífico

    Directory of Open Access Journals (Sweden)

    VIVIAN MONTECINO

    2001-06-01

    with high rates of photorepair might be more tolerant to UV-B than those species, which depend on the synthesis of UV absorbing compounds as their principal protection mechanismLas microalgas marinas expuestas a radiación ultravioleta (UV presentan una respuesta adaptativa compleja, dada por una serie de mecanismos protectores y reparadores. Diferencias interespecificas en susceptibilidad al UV podrían resultar en la selección de las especies más tolerantes, alterándose así la estructura de los ensambles fitoplanctónicos. La importancia relativa de los mecanismos de protección y reparación frente a un potencial incremento de UV-B se estudió en monocultivos de cuatro especies aisladas de la costa de Chile que presentan diferencias taxonómicas, ecológicas y de tamaño: Alexandrium catenella Whedon et Kofoid Balech (dinoflagelado, Phaeodactylum tricornutum Bohlin (diatomea, Aureococcus sp. (crisoficea y Spirulina subsalsa Oersted (cianobacteria bentónica. Diferencias en tasas de fotosíntesis y crecimiento (µ se producirían porque la capacidad efectiva de aclimatación al UV entre microalgas no es universal. Cultivos en fase exponencial fueron primero aclimatados a 16 h día-1 de PAR + RUV-A (365 nm, 140-240 kJ m-2 d-1 y luego los tratamientos suplementados con 2 h d-1 alto y bajo RUV-B (313 nm, dosis máxima: 3,1 kJ m-2 d-1 al centro del período iluminado. Durante tres ciclos de fotoperiodo se estimó tasa de crecimiento (µ, absorción espectral in vivo, capacidad de fluorescencia celular, concentración de pigmentos fotosintéticos, tasa de fotosíntesis y fotorreactivación en cultivos control y tratamientos. Mientras que µ en Phaeodactylum y Aureococcus disminuyó en menos de un 35 %, Alexandrium y Spirulina presentaron una disminución entre 80-100 %. En estas últimas dos especies se observó un incremento significativo de compuestos absorbedores de RUV, probablemente debido a la presencia de sustancias tipo micosporinas (MAAs y scytonemin, as

  20. Cirurgia vídeo-assistida para a ablação da fibrilação atrial isolada por radiofrequência bipolar Cirugía videoasistida para ablación de fibrilación atrial aislada por radiofrecuencia bipolar Videothoracoscopy for isolated atrial fibrillation ablation through bipolar radiofrequency

    Directory of Open Access Journals (Sweden)

    Alexandre Siciliano Colafranceschi

    2009-10-01

    Full Text Available FUNDAMENTO: A prevalência da fibrilação atrial, os gastos com o sistema de saúde e a elevada morbidade e mortalidade associadas a ela, têm justificado a procura por novas abordagens terapêuticas. OBJETIVO: Avaliar a reprodutibilidade da técnica cirúrgica, a segurança e os resultados inicias da cirurgia vídeo-assistida para a ablação da fibrilação atrial isolada com radiofrequência bipolar. MÉTODOS: Dez pacientes (90% homens com fibrilação atrial (50% paroxística sintomática e refratária à terapia medicamentosa, sem doença cardíaca que requeresse cirurgia concomitante, foram submetidos à ablação da arritmia guiada por toracoscopia, no período de maio de 2007 a maio de 2008. Variáveis clínicas, laboratoriais e de imagem foram prospectivamente coletadas antes, durante e no seguimento pós-operatório. RESULTADOS: A cirurgia foi realizada conforme o planejado em todos os pacientes. Não houve lesão iatrogênica de estruturas intratorácicas ou óbitos. No seguimento médio de seis meses, 80% dos pacientes estão livres de fibrilação atrial. Houve melhora significativa dos sintomas de insuficiência cardíaca classe funcional New York Heart Association (2,4 ± 0,5 para 1,6 ± 0,7; p = 0,011. Não houve evidência de estenose de veias pulmonares à angiotomografia, nesta série. CONCLUSÃO: A cirurgia vídeo-assistida para o tratamento da fibrilação atrial é reprodutível e segura. Há melhora evolutiva dos sintomas de insuficiência cardíaca após a cirurgia.FUNDAMENTO: La prevalencia de la fibrilación atrial, los gastos con el sistema de salud y la elevada morbilidad y mortalidad asociados a ésta, justifican la búsqueda de nuevos abordajes terapéuticos. OBJETIVO: Evaluar la reproducibilidad de la técnica quirúrgica, la seguridad y los resultados iniciales de la cirugía videoasistida para la ablación de la fibrilación atrial aislada con radiofrecuencia bipolar. MÉTODOS: Diez pacientes (90% hombres con

  1. The Interaction between Heterotrophic Bacteria and Coliform, Fecal Coliform, Fecal Streptococci Bacteria in the Water Supply Networks

    OpenAIRE

    Nazak AMANIDAZ; Ali ZAFARZADEH; Amir Hossein MAHVI

    2015-01-01

    Background: This study investigated the interaction between heterotrophic bacteria and coliform, fecal coliforms, fecal streptococci bacteria in water supply networks.Methods: This study was conducted during 2013 on water supply distribution network in Aq Qala City, Golestan Province, Northern Iran and standard methods were applied for microbiological analysis. The surface method was applied to test the heterotrophic bacteria and MPN method was used for coliform, fecal coliform and fecal stre...

  2. Effect of air pollution on the total bacteria and pathogenic bacteria in different sizes of particulate matter.

    Science.gov (United States)

    Liu, Huan; Zhang, Xu; Zhang, Hao; Yao, Xiangwu; Zhou, Meng; Wang, Jiaqi; He, Zhanfei; Zhang, Huihui; Lou, Liping; Mao, Weihua; Zheng, Ping; Hu, Baolan

    2018-02-01

    In recent years, air pollution events have occurred frequently in China during the winter. Most studies have focused on the physical and chemical composition of polluted air. Some studies have examined the bacterial bioaerosols both indoors and outdoors. But few studies have focused on the relationship between air pollution and bacteria, especially pathogenic bacteria. Airborne PM samples with different diameters and different air quality index values were collected in Hangzhou, China from December 2014 to January 2015. High-throughput sequencing of 16S rRNA was used to categorize the airborne bacteria. Based on the NCBI database, the "Human Pathogen Database" was established, which is related to human health. Among all the PM samples, the diversity and concentration of total bacteria were lowest in the moderately or heavily polluted air. However, in the PM2.5 and PM10 samples, the relative abundances of pathogenic bacteria were highest in the heavily and moderately polluted air respectively. Considering the PM samples with different particle sizes, the diversities of total bacteria and the proportion of pathogenic bacteria in the PM10 samples were different from those in the PM2.5 and TSP samples. The composition of PM samples with different sizes range may be responsible for the variances. The relative humidity, carbon monoxide and ozone concentrations were the main factors, which affected the diversity of total bacteria and the proportion of pathogenic bacteria. Among the different environmental samples, the compositions of the total bacteria were very similar in all the airborne PM samples, but different from those in the water, surface soil, and ground dust samples. Which may be attributed to that the long-distance transport of the airflow may influence the composition of the airborne bacteria. This study of the pathogenic bacteria in airborne PM samples can provide a reference for environmental and public health researchers. Copyright © 2017 Elsevier Ltd

  3. Determination of Ammonia Oxidizing Bacteria and Nitrate Oxidizing Bacteria in Wastewater and Bioreactors

    Science.gov (United States)

    Francis, Somilez Asya

    2014-01-01

    The process of water purification has many different physical, chemical, and biological processes. One part of the biological process is the task of ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB). Both play critical roles in the treatment of wastewater by oxidizing toxic compounds. The broad term is nitrification, a naturally occurring process that is carried out by AOB and NOB by using oxidation to convert ammonia to nitrite and nitrite to nitrate. To monitor this biological activity, bacterial staining was performed on wastewater contained in inoculum tanks and biofilm samples from bioreactors. Using microscopy and qPCR, the purpose of this experiment was to determine if the population of AOB and NOB in wastewater and membrane bioreactors changed depending on temperature and hibernation conditions to determine the optimal parameters for AOB/NOB culture to effectively clean wastewater.

  4. Bacteria, some permanent tenants Space Station; Bacteria, unos inquilinos permanentes de la estacion espacial

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, B.

    2015-07-01

    Vacuum cleaners to operate the vacuum or rags with ethanol they are the products of cleaning of the astronauts. Is there tight spaces fully sterilized? It seems not, even in the Space Station International (ISS). When it comes to bacteria, they are able to travel more than 400 kilometers housed in costumes, bodies and interior of the astronauts themselves and settle in a enclosed space where-unlike in a {sup c}leanroom 'terrestre- the air is not recycled. A NASA study has found an abundance of bacteria 'opportunists' which, although harmless on Earth, they might derivasen cause infections in inflammations or skin irritations. Not forgetting those fungi that could damage or affect the infrastructure equipment space. (Author)

  5. Isolation of Crude Oil from Polluted Waters Using Biosurfactants Pseudomonas Bacteria: Assessment of Bacteria Concentration Effects

    Directory of Open Access Journals (Sweden)

    A. Khalifeh

    2013-04-01

    Full Text Available Biological decomposition techniques and isolation of environmental pollutions using biosurfactants bacteria are effective methods of environmental protection. Surfactants are amphiphilic compounds that are produced by local microorganisms and are able to reduce the surface and the stresses between surfaces. As a result, they will increase solubility, biological activity, and environmental decomposition of organic compounds. This study analyzes the effects of biosurfactants on crude oil recovery and its isolation using pseudomonas sea bacteria species. Preparation of biosurfactants was done in glass flasks and laboratory conditions. Experiments were carried out to obtain the best concentration of biosurfactants for isolating oil from water and destroying oil-in-water or water-in-oil emulsions in two pH ranges and four saline solutions of different concentrations. The most effective results were gained when a concentration of 0.1% biosurfactants was applied.

  6. Spatial scales of interactions among bacteria and between bacteria and the leaf surface

    Science.gov (United States)

    Esser, Daniel S.; Leveau, Johan H.J.; Meyer, Katrin M.; Wiegand, Kerstin

    2014-01-01

    Microbial life on plant leaves is characterized by a multitude of interactions between leaf colonizers and their environment. While the existence of many of these interactions has been confirmed, their spatial scale or reach often remained unknown. In this study, we applied spatial point pattern analysis to 244 distribution patterns of Pantoea agglomerans and Pseudomonas syringae on bean leaves. The results showed that bacterial colonizers of leaves interact with their environment at different spatial scales. Interactions among bacteria were often confined to small spatial scales up to 5–20 μm, compared to interactions between bacteria and leaf surface structures such as trichomes which could be observed in excess of 100 μm. Spatial point-pattern analyses prove a comprehensive tool to determine the different spatial scales of bacterial interactions on plant leaves and will help microbiologists to better understand the interplay between these interactions. PMID:25764562

  7. Number of Bacteria and Time of Coincubation With Bacteria Required for the Development of Acanthamoeba Keratitis.

    Science.gov (United States)

    Nakagawa, Hayate; Hattori, Takaaki; Koike, Naohito; Ehara, Tomoko; Narimatsu, Akitomo; Kumakura, Shigeto; Matsumoto, Tetsuya; Goto, Hiroshi

    2017-03-01

    We hypothesized that bacteria may be a factor contributing to the development of Acanthamoeba keratitis (AK). We investigated interactions between Acanthamoeba and Pseudomonas aeruginosa for the development of keratitis in rabbit corneas. Acanthamoeba castellanii (ATCC50492) and P. aeruginosa (PAO-1) were used. Two densities of P. aeruginosa (high, 1 × 10/mL; low, 3 × 10/mL) and 2 durations of coincubation (long, 6 h; short, 2 h) of Acanthamoeba with 1 × 10/mL of P. aeruginosa were tested. Acanthamoeba alone or Acanthamoeba coincubated with P. aeruginosa was inoculated into rabbit corneas. After inoculation, levofloxacin (LVFX) eye drops were administered. The clinical score of the cornea was evaluated after inoculation. Acanthamoeba alone did not produce keratitis during a 5-day observation period. Rabbit corneas inoculated with Acanthamoeba coincubated with low-density P. aeruginosa followed by topical LVFX were clear with few infiltrates. Corneas inoculated with Acanthamoeba coincubated with high-density P. aeruginosa followed by LVFX treatment developed severe keratitis, and clinical scores were significantly higher compared with high-density P. aeruginosa alone followed by LVFX treatment (scores 7, 9.6, 8.5 vs. 3, 3.5, 3.25 on days 1-3, all P Acanthamoeba with high-density P. aeruginosa resulted in more severe keratitis compared with short (2 h) coincubation (scores, 9.7, 12.7, 12.1, 9.8, 8.7 vs. 7, 9.6, 8.5, 6.9, 5.6 on days 1-5, all P < 0.01). These results suggest that the presence of bacteria is essential and a critical number of bacteria is required for the development of AK. The time of coexistence with bacteria may be an important determinant of the severity of AK.

  8. Seed-vectored endophytic bacteria modulate development of rice seedlings.

    Science.gov (United States)

    Verma, S K; Kingsley, K; Irizarry, I; Bergen, M; Kharwar, R N; White, J F

    2017-06-01

    The aim of the present study was to evaluate the effects of the removal of indigenous bacteria from rice seeds on seedling growth and development. Here we report the presence of three indigenous endophytic bacteria in rice seeds that play important roles in modulating seedling development (shoot and root lengths, and formation of root hairs and secondary roots) and defence against pathogens. Seed-associated bacteria were removed using surface sterilization with NaOCl (bleach) followed by antibiotic treatment. When bacteria were absent, growth of seedlings in terms of root hair development and overall seedling size was less than that of seedlings that contained bacteria. Reactive oxygen staining of seedlings showed that endophytic bacteria became intracellular in root parenchyma cells and root hairs. Roots containing endophytic bacteria were seen to stain densely for reactive oxygen, while roots free of bacteria stained lightly for reactive oxygen. Bacteria were isolated and identified as Enterobacter asburiae (VWB1), Pantoea dispersa (VWB2) and Pseudomonas putida (VWB3) by 16S rDNA sequencing. Bacteria were found to produce indole acetic acid (auxins), inhibited the pathogen Fusarium oxysporum and solubilized phosphate. Reinoculation of bacteria onto seedlings derived from surface-disinfected rice and Bermuda grass seeds significantly restored seedling growth and development. Rice seeds harbour indigenous bacterial endophytes that greatly influence seedling growth and development, including root and shoot lengths, root hair formation and disease susceptibility of rice seedlings. This study shows that seeds of rice naturally harbour bacterial endophytes that play key roles in modulation of seedling development. © 2017 The Society for Applied Microbiology.

  9. Predatory Bacteria Attenuate Klebsiella pneumoniae Burden in Rat Lungs

    Directory of Open Access Journals (Sweden)

    Kenneth Shatzkes

    2016-11-01

    Full Text Available Bdellovibrio bacteriovorus and Micavibrio aeruginosavorus are predatory bacteria that naturally—and obligately—prey on other Gram-negative bacteria, and their use has been proposed as a potential new approach to control microbial infection. The ability of predatory bacteria to prey on Gram-negative human pathogens in vitro is well documented; however, the in vivo safety and efficacy of predatory bacteria have yet to be fully assessed. In this study, we examined whether predatory bacteria can reduce bacterial burden in the lungs in an in vivo mammalian system. Initial safety studies were performed by intranasal inoculation of rats with predatory bacteria. No adverse effects or lung pathology were observed in rats exposed to high concentrations of predatory bacteria at up to 10 days postinoculation. Enzyme-linked immunosorbent assay (ELISA of the immune response revealed a slight increase in inflammatory cytokine levels at 1 h postinoculation that was not sustained by 48 h. Additionally, dissemination experiments showed that predators were efficiently cleared from the host by 10 days postinoculation. To measure the ability of predatory bacteria to reduce microbial burden in vivo, we introduced sublethal concentrations of Klebsiella pneumoniae into the lungs of rats via intranasal inoculation and followed with multiple doses of predatory bacteria over 24 h. Predatory bacteria were able to reduce K. pneumoniae bacterial burden, on average, by more than 3.0 log10 in the lungs of most rats as measured by CFU plating. The work presented here provides further support for the idea of developing predatory bacteria as a novel biocontrol agent.

  10. Acetic acid bacteria: A group of bacteria with versatile biotechnological applications.

    Science.gov (United States)

    Saichana, Natsaran; Matsushita, Kazunobu; Adachi, Osao; Frébort, Ivo; Frebortova, Jitka

    2015-11-01

    Acetic acid bacteria are gram-negative obligate aerobic bacteria assigned to the family Acetobacteraceae of Alphaproteobacteria. They are members of the genera Acetobacter, Gluconobacter, Gluconacetobacter, Acidomonas, Asaia, Kozakia, Swaminathania, Saccharibacter, Neoasaia, Granulibacter, Tanticharoenia, Ameyamaea, Neokomagataea, and Komagataeibacter. Many strains of Acetobacter and Komagataeibacter have been known to possess high acetic acid fermentation ability as well as the acetic acid and ethanol resistance, which are considered to be useful features for industrial production of acetic acid and vinegar, the commercial product. On the other hand, Gluconobacter strains have the ability to perform oxidative fermentation of various sugars, sugar alcohols, and sugar acids leading to the formation of several valuable products. Thermotolerant strains of acetic acid bacteria were isolated in order to serve as the new strains of choice for industrial fermentations, in which the cooling costs for maintaining optimum growth and production temperature in the fermentation vessels could be significantly reduced. Genetic modifications by adaptation and genetic engineering were also applied to improve their properties, such as productivity and heat resistance. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Laminar flow assisted anisotropic bacteria absorption for chemotaxis delivery of bacteria-attached microparticle

    Science.gov (United States)

    Huh, Keon; Oh, Darong; Son, Seok Young; Yoo, Hyung Jung; Song, Byeonghwa; Cho, Dong-il Dan; Seo, Jong-Mo; Kim, Sung Jae

    2016-12-01

    The concepts of microrobots has been drawn significant attentions recently since its unprecedented applicability in nanotechnology and biomedical field. Bacteria attached microparticles presented in this work are one of pioneering microrobot technology for self-propulsion or producing kinetic energy from ambient for their motions. Microfluidic device, especially utilizing laminar flow characteristics, were employed for anisotropic attachment of Salmonella typhimurium flagellated chemotactic bacteria to 30 um × 30 um and 50 um × 50 um microparticles that made of biodegradable polymer. Any toxic chemicals or harmful treatments were excluded during the attachment process and it finished within 100 s for the anisotropic attachment. The attachments were directly confirmed by fluorescent intensity changes and SEM visualization. Chemotaxis motions were tracked using aspartate and the maximum velocity of the bacteria-attached microrobot was measured to be 5 um/s which is comparable to prior state of art technologies. This reusable and scalable method could play a key role in chemotaxis delivery of functional microparticles such as drug delivery system.

  12. Bioactive proteins against pathogenic and spoilage bacteria

    Directory of Open Access Journals (Sweden)

    Mahmoud Z. Sitohy

    2014-10-01

    Full Text Available Background: It is likely that both human nutrition and the nutrition of livestock are benefited by the presence of bioactive proteins within their respective diet regimes. Bioactive proteins have been defined as specific protein fragments that positively impact bodily functions or conditions and may, ultimately, influence overall human health. The ingestion of bioactive proteins may have an effect on the major body systems—namely, the cardiovascular, digestive, immune and nervous systems. According to their functional properties, bioactive proteins may be classified as antimicrobial, antithrombotic, antihypertensive, opioid, immune-modulatory, mineral binding and anti-oxidative. There are many examples of biologically active food proteins and active peptides that can be obtained from various food protein sources. They have a physiological significance beyond the pure nutritional requirements; in other wordsthey have the acquisition of nitrogen for normal growth and maintenance. Objective: This study aims to specify and characterize the extent and mode of action of bioactive proteins in their native form, (glycinin, glycinin basic sub-unit and β-conglycinin against specific main pathogens (Listeria monocytogenes, Escherichia coli O157:H7 and Salmonella enterica serovar Enteritidis. We will be using standard media while identifying the main constituents responsible for this action. Methods: Glycinin, basic sub-unit and β-conglycinin were isolated from soybean protein and tested for their antimicrobial action against pathogenic and spoilage bacteria, They were thencompared to the properties of penicillin. Methylated soybean protein and also methylated chickpea protein (MSP and MCP, with isoelectric points around pI 8, were prepared by esterifying. 83 % of their free carboxyl groups and their interactions with Gram positive and Gram negative bacteria were examined. Results: The three divisions of cationic proteins exhibited antibacterial

  13. Isolation and Molecular Identification of Endophytic Bacteria From Rambutan Fruits (Nephelium lappaceum L.) Cultivar Binjai

    OpenAIRE

    Sony Suhandono; Meirina Kartika Kusumawardhani; Pingkan Aditiawati

    2016-01-01

    Interactions between plants and endophytic bacteria are mutualistic. Plant provides nutrient for bacteria, and bacteria will protect the plant from pathogen, help the phytohormone synthesis and nitrogen fixation, and also increase absorption of minerals. These bacteria called plant growth-promoting bacteria. The aim for this study is to identify endophytic bacteria on rambutan (Nephelium lappaceum L.) cultivar Binjai with 16S rRNA. Sequencing results showed that the bacteria is derived from g...

  14. [Isolation and study of azobenzene converting soil bacteria].

    Science.gov (United States)

    Vakkerov-Kouzova, N D

    2005-01-01

    Heterotrophic bacteria were isolated from soil and glass slides and classified as Bacillus cereus SNK12, Paenibacillus polymyxa SNK2, Azotobacter chroococcum ANKII, and Ochrobacterium intermedium ANKI. Their cultures could degrade azobenzene under the conditions of co-metabolism. A rapid test for the ability of bacteria to convert azobenzenes is proposed.

  15. Isolation And Characterization Of Lactic Acid Bacteria In Kirario, An ...

    African Journals Online (AJOL)

    The lactic acid bacteria (LAB) are the most diverse groups of bacteria known, and have been used by many communities in the World in spontaneous fermentation to produce fermented porridges with unique technological characteristics. Kirario is a traditional fermented porridge based on green maize, millet and/or ...

  16. Nitrogen acquisition in Agave tequilana from degradation of endophytic bacteria.

    Science.gov (United States)

    Beltran-Garcia, Miguel J; White, James F; Prado, Fernanda M; Prieto, Katia R; Yamaguchi, Lydia F; Torres, Monica S; Kato, Massuo J; Medeiros, Marisa H G; Di Mascio, Paolo

    2014-11-06

    Plants form symbiotic associations with endophytic bacteria within tissues of leaves, stems, and roots. It is unclear whether or how plants obtain nitrogen from these endophytic bacteria. Here we present evidence showing nitrogen flow from endophytic bacteria to plants in a process that appears to involve oxidative degradation of bacteria. In our experiments we employed Agave tequilana and its seed-transmitted endophyte Bacillus tequilensis to elucidate organic nitrogen transfer from (15)N-labeled bacteria to plants. Bacillus tequilensis cells grown in a minimal medium with (15)NH4Cl as the nitrogen source were watered onto plants growing in sand. We traced incorporation of (15)N into tryptophan, deoxynucleosides and pheophytin derived from chlorophyll a. Probes for hydrogen peroxide show its presence during degradation of bacteria in plant tissues, supporting involvement of reactive oxygen in the degradation process. In another experiment to assess nitrogen absorbed as a result of endophytic colonization of plants we demonstrated that endophytic bacteria potentially transfer more nitrogen to plants and stimulate greater biomass in plants than heat-killed bacteria that do not colonize plants but instead degrade in the soil. Findings presented here support the hypothesis that some plants under nutrient limitation may degrade and obtain nitrogen from endophytic microbes.

  17. Influence of carbohydrates on the isolation of lactic acid bacteria.

    Science.gov (United States)

    Endo, A; Futagawa-Endo, Y; Dicks, L M T

    2011-04-01

      To determine the influence of carbohydrates on enrichment isolation of lactic acid bacteria from different niches.   Lactic acid bacteria in three traditional fermented products in southern Africa (amasi, mahewu and tshwala) and in three fresh samples (two flowers and a fruit) were enrichment cultured in media supplemented with 13 different carbohydrates. Diversity of lactic acid bacteria was determined by PCR-denaturing-gradient gel electrophoresis. Carbohydrates used in enrichment media had a big impact on the isolation of lactic acid bacteria from fermented products. Depending on the carbohydrates tested, the number of species detected ranged from one to four in amasi, one to five in mahewu and one to three in tshwala. Fructose and mannitol selected for relatively higher numbers of lactic acid bacteria in fermented products. Specific relationships between substrates and lactic acid bacteria have been noted. On the other hand, small influences were found among carbohydrates tested in flowers and fruit.   Carbohydrates have a big impact on the isolation of a variety of lactic acid bacteria in fermented food.   This is the first study that reports the influence of carbohydrates on the enrichment of lactic acid bacteria. © 2011 The Authors. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology.

  18. Rapid separation of bacteria from blood - Chemical aspects.

    Science.gov (United States)

    Alizadeh, Mahsa; Wood, Ryan L; Buchanan, Clara M; Bledsoe, Colin G; Wood, Madison E; McClellan, Daniel S; Blanco, Rae; Ravsten, Tanner V; Husseini, Ghaleb A; Hickey, Caroline L; Robison, Richard A; Pitt, William G

    2017-06-01

    To rapidly diagnose infectious organisms causing blood sepsis, bacteria must be rapidly separated from blood, a very difficult process considering that concentrations of bacteria are many orders of magnitude lower than concentrations of blood cells. We have successfully separated bacteria from red and white blood cells using a sedimentation process in which the separation is driven by differences in density and size. Seven mL of whole human blood spiked with bacteria is placed in a 12-cm hollow disk and spun at 3000rpm for 1min. The red and white cells sediment more than 30-fold faster than bacteria, leaving much of the bacteria in the plasma. When the disk is slowly decelerated, the plasma flows to a collection site and the red and white cells are trapped in the disk. Analysis of the recovered plasma shows that about 36% of the bacteria is recovered in the plasma. The plasma is not perfectly clear of red blood cells, but about 94% have been removed. This paper describes the effects of various chemical aspects of this process, including the influence of anticoagulant chemistry on the separation efficiency and the use of wetting agents and platelet aggregators that may influence the bacterial recovery. In a clinical scenario, the recovered bacteria can be subsequently analyzed to determine their species and resistance to various antibiotics. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Niche differentiation between ammonia-oxidizing bacteria in aquatic environments

    NARCIS (Netherlands)

    Coci, M.

    2007-01-01

    The aim of the studies presented in this thesis was the search for niche differentiation between the ammonia-oxidizing bacteria in aquatic environments. Ammonia-oxidizing bacteria are chemolitho-autotrophic microorganisms responsible for the first, mostly rate-limiting step of the nitrification

  20. Can bacteria adapt to starvation-free environment?

    OpenAIRE

    Kei Kitahara

    2012-01-01

    Bacteria will experience starvation-free environment if infinite nutrition is supplied continuously for a long period. In this study, an evolutionary experiment was performed for 118 days where bacteria adapted to starvation-free environment and reduced their doubling time. It is anticipated that this finding will help to select bacterial strains that can grow more rapidly in rich media.