Sample records for DEFORMACIONES (strains)
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1

Presencia de cepas diarreogénicas de Escherichia coli y estudio de genes de virulencia en aislados desde fecas de dos poblaciones de lobo marino común, Otaria flavescens en el norte de Chile/ Presence of diarrheagenic strains of Escherichia coli and virulence genes study in isolates from feces of two populations of South American sea lion, Otaria flavescens in Northern Chile

Salinas C, Paula; Moraga M, Rubén; Santander P, Edgardo; Sielfeld K, Walter
2010-04-01

Resumen en inglés This research analyzed the effect of fecal contamination caused by sewage, and its relationship with the presence of enteropathogenic strains of Escherichia coli in the feces of South American sea lions (Otaria flavescens) from Iquique Bay and surrounding waters. The E. coli strains isolated from the water column of the bay and sewage outlet, showed the presence of the gene eae. In the strains isolated from the feces of both sea lion colonies no presence of virulent diarr (mas) heagenic genes was detected. The genotyping of strains resulted in clusters according to their origin and showed separation of the samples of E. coli population of the colonies of sea lions and those of the strains isolated from the column water of Iquique Bay

Scientific Electronic Library Online (Spanish)

2

Selección de cepas de rizobios aisladas de ecosistemas ganaderos de Cuba, inoculadas en trigo (Triticum aestivum, L.)/ Selection of rhizobia strains isolated from Cuban livestock production ecosystems, inoculated in wheat (Triticum aestivum, L.)

Bécquer, C.J; Salas, Beatriz; Ávila, U; Palmero, L; Nápoles, J.A; Ulloa, Lisbet
2008-03-01

Resumen en español Se efectuó un experimento de campo con el objetivo de seleccionar cepas de rizobio inoculadas en trigo (Triticum aestivum, L., var. Cuba-204), en el cual se evaluaron indicadores agroproductivos de la planta, tales como: peso seco aéreo, longitud del tallo, rendimiento de granos, peso de 1 000 granos y rendimiento de nitrógeno. Se utilizaron tres cepas de referencia, pertenecientes a diferentes géneros y especies de rizobio y 12 cepas nativas del género Bradyrhizobiu (mas) m, que fueron aisladas de raíces de leguminosas (Centrosema, Neonotonia y Stylosanthes), adaptadas a ecosistemas ganaderos de Sancti Spiritus, Cuba. Se aplicó un diseño experimental de bloques completamente aleatorizados, con 16 tratamientos y cuatro réplicas; uno de los tratamientos se fertilizó con 150 kg/ha (NH4NO3). Hubo tratamientos inoculados con las cepas comerciales USDA 191 y 25B6, y con las cepas nativas cubanas JH2, SP23, SP8, SP4, HG2 y JH1, que resultaron estadísticamente superiores al control fertilizado. Se concluye que la inoculación con rizobios influye notablemente en el desarrollo integral de la planta y que las cepas de rizobio utilizadas pueden constituir un recurso biológico valioso para la fertilización de trigo en Cuba, por lo que se recomiendan como una alternativa de alto valor ecológico y económico para la agricultura cubana. Resumen en inglés A field experiment was carried out in order to select rhizobial strains inoculated to wheat (Triticum aestivum, L., var. Cuba-204). Several parameters of agricultural significance were assessed, such as: aerial dry weight, length of stems, grain yield, weight of 1 000 grains and nitrogen yield. Three reference strains, belonging to several rhizobial genera and species were used, as well as twelve native strains, belonging to Bradyrhizobium that were isolated from roots of (mas) legumes (Centrosema, Neonotonia and Stylosanthes), adapted to Cuban livestock ecosystems. A completely randomized block experimental design with 16 treatments and four replications was used. A treatment was fertilized with 150 kg/ha (NH4NO3). It was concluded that reference strains USDA 191 and 25B6, as well as native strains JH2, SP23, SP8, SP4, HG2 and JH1 were statistically higher than the fertilized control. Rhizobial inoculation positively enhanced general plants growth and development, expressed in Nitrogen content. It was demonstrated that rhizobial strains used in the experiments may constitute a valuable biological resource for the fertilization of wheat in Cuba. Biofertilization of wheat with rhizobia is strongly recommended as an alternative of a high ecological and economic value for the agriculture of Cuba.

Scientific Electronic Library Online (Spanish)

3

Caracterización de cepas de Lactarius sección Deliciosi de Guatemala y su comparación con cepas europeas de L. deliciosus/ Characterizing strains of Lactarius section Deliciosi from Guatemala and its comparison with European strains of L. deliciosus

Flores, Roberto; Honrubia, Mario; Díaz, Gisela
2008-06-01

Resumen en español Se mencionan las características morfológicas de cultivos miceliares de 8 cepas de Lactarius de la sección Deliciosi procedentes de Guatemala (2 Lactarius deliciosus s.l, 1 L. aff. salmonicolor, 3 L. indigo y 2 L. aff. rubrilacteus) y 2 cepas de L. deliciosus Europeos procedentes de España, cultivados en medio BAF a 4 valores de pH. El máximo crecimiento se obtuvo a diferente pH según la cepa. Las colonias de L. deliciosus resultaron ser diferentes en color, forma y (mas) textura según su origen. Mientras las Europeas son notoriamente fibrilosas y con mechones hirsutos de color amarillo a naranja en la superficie, las Neotropicales forman colonias fibrilosas muy compactas o fibriloso-tomentosas de color naranja-rosado a canela. Estas notorias diferencias de los micelios en cultivo puro apoyan la posibilidad de que sean especies diferentes. Resumen en inglés The morphological features of the mycelial cultures of 8 Lactarius strains belonging to the section Deliciosi from Guatemala (2 Lactarius deliciosus s.l, 1 L. aff. salmonicolor, 3 L. indigo y 2 L. aff. rubrilacteus) and 2 L. deliciosus strains from Spain are described. They were grown in BAF medium at 4 different pH values. The maximal growth was obtained at different pH values for each fungal strain. The colonies of L. deliciosus were different in colour, shape and textu (mas) re depending on its geographical origin. Whereas European strains were fibrillose and with surface yellow to orange, the Neotropical ones were densely fibrillose and orange-pinkish to cinnamon. That features support the possibility that European and Neotropical and L. deliciosus are different species.

Scientific Electronic Library Online (Spanish)

4

Caracterización de cepas de Bacillus thuringiensis Berliner y actividad biológica hacia Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) y Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae)/ Caracterization of Bacillus thuringiensis Berliner Strains and Biological Activity on Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) and Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae)

Baró Robaina, Yamilé; fontana Capalbo, Deise M; Dos Santos Nascimento, Rosely
2009-09-01

Resumen en español Se realizó la caracterización de nueve cepas cubanas de Bacillus thuringiensis según la morfología del cristal, la determinación del patrón de proteínas Cry y la actividad biológica frente a los insectos lepidópteros Spodoptera frugiperda y Anticarsia gemmatalis. Se observó la típica morfología bipiramidal en todas las cepas, y además la presencia de inclusiones cúbicas. El patrón de proteínas Cry obtenido correspondió con el de la cepa estándar internac (mas) ional de B. thuringiensis var. kurstaki cepa HD1, en el que se observan dos bandas bien definidas correspondientes a la proteína Cry 1 (130 kDa) y Cry 2 (70 kDa). En la evaluación de la actividad biológica las cepas LBT 4 y LBT 7 causaron el 100% de mortalidad frente a S. frugiperda, mientras que las LBT 4, LBT 7, LBT 13 y LBT 47 provocaron el 100% de mortalidad para A. gemmatalis. Resumen en inglés This study describes the characterization of nine Cuban Bacillus thuringiensis strains based on crystal morphology, SDS polyacrylamide electrophoresis (PAGE) and insecticidal activity against Spodoptera frugiperda and Anticarsia gemmatalis.Ultrastructural analysis of parasporal bodies of the nine strains showed the typical bipyramidal crystal and cubic inclusion partially embedded in the middle of the bipyramidal crystal. The PAGE analysis showed two bands of 130 kDa and (mas) 70 kDa belongs to Cry 1 and Cry 2 protein present to HD1 standard strains B. thuringiensis var. kurstaki.The strains LBT 4 and LBT 7 analyzed in this report showed potential as biological insecticide against S. frugiperda and LBT 4, LBT 7, LBT13 and LBT47 strains showed 100% of mortality to Anticarsia gemmatalis.

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5

Obtención de cepas de lactobacillus.: Caracterización in-vitro como potenciales probióticas./ Obtention of Lactobacillus strains.: In-Vitro Characterization as Potentials Probiotics.

Mejía Rodríguez, José Andrés; Chacón Rueda, Zarack; Guerrero Cárdenas, Balmore; Otoniel Rojas, Julio; López Corcuera, Guillermo
2007-04-01

Resumen en español En el presente trabajo se aislaron trescientas sesenta cepas de microorganismos a partir de heces de niños lactantes y muestras vaginales de diez mujeres. Sólo veintidós se identificaron como Lactobacillus. Éstas fueron resistentes a condiciones hostiles como pH 3 y 0,30% de sales biliares. En los caldos de cultivo donde crecieron estas cepas se detectó actividad antimicrobiana contra: Bacillus subtilis ATCC 60519, Candida albicans ATCC 14053, Escherichia coli ATCC 2 (mas) 5922 y Staphylococcus aureus ATCC 25923 y contra cepas bacterianas enteropatógenas como Shigella sonnei, Escherichia coli poli I y Salmonella typhi aisladas de infantes con diarrea. Se observó resistencia de las cepas de Lactobacillus a una mezcla de 1,25 µg de trimetropim y 23,75 µg de sulfametoxazol, pero todas fueron sensibles a 10 µg de ampicilina. Estas cepas pueden considerarse posibles probióticas de gran utilidad en la industria láctea. Resumen en inglés In this work three hundred and sixty strains of microorganisms were isolated from feces of nursing children and vaginal samples of ten women. Only twenty-two of the strains were identified as Lactobacillus. They were resistant to hostile conditions such as pH 3 and 0.30% of bile salts. It was detected antimicrobial activity in the growth supernatant against: Bacillus subtilis ATCC 60519, Candida albicans ATCC 14053, Escherichia coli ATCC 25922 and Staphylococcus aureus AT (mas) CC 25923 and against enteropatogenics bacteria strains such as Shigella sonnei, Escherichia coli poli I and Salmonella typhi isolated of infants with diarrhea. It was observed resistance of Lactobacillus strains to a mixture of 1.25 µg of trimethoprim and 23.75 µg of sulphamethoxazole. However they were sensitive to 10 µg of ampiciline. These strains can be considered as posibles probiotics of great utility in the dairy industry.

Scientific Electronic Library Online (Spanish)

6

Evaluación de cepas de Bacillus thuringiensis para el control de Drosophila melanogaster Maengi/ Evaluation of Bacillus thuringiensis Strains for the control of Drosophila melanogaster Maengi

Carreras Solís, Bertha; Rodríguez Batista, Dayamí
2009-06-01

Resumen en español El uso de Bacillus thuringiensis como biolarvicida es una alternativa viable para el control de insectos, por lo que el número de cepas activas contra diptera está en ascenso. En el presente trabajo se realizó la caracterización de cepas de esta bacteria aisladas de las diferentes regiones de Cuba, la cual se basó en la actividad insecticida contra Drosophila melanogaster, observación al microscopio electrónico de la mezcla de esporas y cristales, y electroforesis (mas) en gel de poliacrilamida con duodecil sulfato de sodio de la suspensión de esporas-cristales. Las cepas LBT-63 y LBT-87 mostraron similitudes con el B. thuringiensis subsp. israelensis usado en este estudio, en relación con el perfil proteico y la morfología de las inclusiones cristalinas. Estas cepas mostraron proteínas de 130, 70 y 27 kDa y cristales amorfos; sin embargo, solamente la cepa LBT-87 mostró actividad contra D. melanogaster, aunque más baja que el B. thuringiensis subs. israelensis control Resumen en inglés The use of Bacillus thuringiensis as biolarvicide is a viable alternative for insect control so the number of known Bacillus thuringiensis strains active on diptera is growing. The characterization of strains of this bacterium isolated from different regions of Cuba is presented. Characterization was based on their insecticidal activity against Drosophila melanogaster, electron microscopy observation of the spores and crystal mixtures and sodium dodecyl sulfatepolyacrylam (mas) ide gel electrophoresis (SDS-PAGE) of spore-crystal suspensions. Strains LBT-63 and LBT-87 displayed similarities with the B. thuringiensis subs. israelensis used in this study with regard profile protein and morphology of crystal inclusions. These strains had major proteins of 130, 70 and 27 kDa and amorphous crystal; however, the strain LBT-87 only showed insecticidal activity against D.melanogaster but lower than B. thuringiensis subs. israelensis control

Scientific Electronic Library Online (Spanish)

7

Caracterización de cepas de Listeria monocytogenes realizados a partir de queso fresco proveniente de diferentes zonas productoras costarricenses/ Characterization of Listeria monocytogenes isolates obtained from raw cheese samples acquired from different Costa Rican producer zones

Cháves, Carolina; Arias, María Laura
2009-03-01

Resumen en español En Costa Rica, cerca del 25% de la producción de leche nacional es utilizada en la elaboración de queso tierno no pasteurizado, y el consumo de este producto es aproximadamente de 4 a 5 kg anuales per cápita. Este alimento ha sido involucrado en brotes debidos a Listeria monocytogenes. Dado lo anterior, se aisló e identificó esta bacteria a partir de muestras de queso blanco no pasteurizado provenientes de dos zonas tradicionalmente productoras y expendedoras de dich (mas) o producto. Se recolectaron 110 muestras de queso a partir de las cuales se aislaron 27 cepas de L. monocytogenes. Las cepas fueron caracterizadas mediante pruebas bioquímicas y serológicas, además se les realizaron pruebas de susceptibilidad a los antibióticos, hemólisis en tubo e invasión en células Hela. El 85% de las cepas evaluadas fueron sensibles a todos los antibióticos analizados, no obstante, cuatro cepas (15%) presentaron patrones de resistencia a diversos agentes, incluyendo estreptomicina, kanamicina, cefalotina y tetraciclina. También, se encontraron patrones de resistencia múltiple. El 88,9% de los aislamientos estudiados fueron positivos para la prueba de hemólisis en tubo, y el 22,2% presentaron porcentajes de invasión iguales o superiores a la cepa de origen clínico usada como control. Cabe destacar que todas las cepas con capacidad de invasión fueron también susceptibles a todos los antibióticos usados. Los resultados encontrados ponen de manifiesto la presencia de L. monocytogenes en queso blanco de origen costarricense. También se evidencia un alto porcentaje de susceptibilidad a los antibióticos de uso común para los casos de listeriosis. Por otro lado, pone de manifiesto que el queso blanco puede ser transmisor de cepas con capacidad de invasión y por ende, potencialmente patógenas al hombre. Resumen en inglés In Costa Rica, almost 25% of the national milk production is used for the elaboration of non pasteurized soft cheese, and the annual intake of this product is around 4-5 kg per capita. This product has been identified as the source of food borne outbreaks due to Listeria monocytogenes. Given that, the isolation and identification of this bacterium from non pasteurized soft cheese samples coming from two producer zones of Costa Rica was performed. 110 cheese samples were c (mas) ollected, from which 27 L. monocytogenes strains were isolated. These were characterized using biochemical and serological tests, also, susceptibility to common used antibiotics, test tube hemolysis and invasion in Hela cells trials were performed. 85% of the strains evaluated were sensible to all the antibiotics analyzed, nevertheless, four strains presented resistance to different agents, including streptomycin, kanamycin, cephalotin and tetracycline. Also, multiple resistance patterns were found. 88,9% of the studied isolates were positive for the test tube hemolysis trial; 22,2% presented invasion percentages higher than the clinical origin strain used as control. It is important to point out that all the invasive strains were completely susceptible to the antibiotics tested. The results found demonstrate the presence of L. monocytogenes in Costa Rican soft cheese samples. Also, demonstrate its high percent of susceptibility to common use antibiotics. Same time, invasion trials show that soft cheese may be a source of invasive and potentially pathogenic strains for human being.

Scientific Electronic Library Online (Spanish)

8

Comportamiento de cepas argentinas del virus de la Coriomeningitis Linfocitaria en roedores/ Behavior of Argentine lymphocytic choriomeningitis virus strains in rodents

Saavedra, María Del Cármen; Ambrosio, Ana M.; Riera, Laura; Sabattini, Marta S.
2007-10-01

Resumen en español La actividad del virus LCM fue informada en Argentina a comienzos de la década del 70 y sólo han sido aisladas cinco cepas a partir del roedor Mus domesticus y dos de humanos. El objetivo de este trabajo consistió en investigar características biológicas de las cepas argentinas de virus LCM para compararlas entre sí y respecto a las cepas históricas WE y Armstrong. En células L 929 se obtuvieron placas bajo agarosa tanto con las cepas humanas como con las cepas de (mas) ratón, pero en células Vero sólo se obtuvieron placas con las cepas humanas. No se observó ninguna característica morfométrica de las placas que distinguiera nítidamente a las cepas históricas de las cepas argentinas, ni se observaron diferencias que se relacionen con las especies de origen de las cepas. Las cepas históricas y las cepas argentinas no fueron letales para ratón recién nacido (rrn) generando una infección persistente, según se comprobó al inocular ratones recién nacidos (rrn) por vía intracerebral con cepas de virus LCM y detectarse virus en los cerebros cosechados a diferentes días post inoculación. La única excepción fue la cepa Cba An 13065 que resultó virulenta para rrn ya que con sólo 0.026 UFP se logró 1 DL50. Todas las cepas resultaron letales en ratón adulto (rad), siendo las cepas de ratón más virulentas que las cepas de humanos. Estos resultados permitieron evidenciar el diferente comportamiento en cultivos celulares de las cepas de ratón con respecto a las cepas humanas, e identificar marcadores de virulencia mediante la respuesta a la inoculación por vía intracerebral del rad y del rrn. Resumen en inglés The activity of LCM virus was first reported in Argentina at the beginning of the seventies and only five strains have been isolated from rodents Mus domesticus and two from humans. The objective of this paper was to find differential biological characteristics of Argentine strains of LCM virus comparing them in relation to the historical strains WE and Armstrong. Regarding the results obtained in tissue culture, when L 929 cells were used, plaque forming units (PFU) were (mas) obtained with human and mouse strains, whilst on Vero cells only human strains developed PFU. Differentials characteristics of historical and Argentine strain's plates were not found, neither differences related to the strain's origin. Neither historical nor Argentine strains were lethal to new-born mice giving a persistent infection, that was demonstrated when we inoculated new-born mouse by intracranial route with different strains of LCM virus and virus was isolated from brains harvested at different days post inoculation. The only exception was Cba An 13065 strain that exhibited virulence in new-born mice, only with 0.026 PFU was obtained 1 DL50. All the strains resulted lethal to adult mice. The mouse strains were more virulent than human strains, being Cba An 13065 the most virulent. These results demonstrate a different behavior in tissue culture between human and mouse strains and allow the identification of virulence markers by intracranial inoculation into new-born or adult mice.

Scientific Electronic Library Online (Spanish)

9

Detección del gen blaVIM-2 en cepas de Pseudomonas aeruginosa productoras de metalo ß-lactamasa aisladas en una unidad de cuidados intensivos en Ciudad Bolívar, Venezuela/ blaVIM-2 gene detection in metallo-ß-lactamase-producing Pseudomonas aeruginosa strains isolated in an Intensive Care Unit in Ciudad Bolívar, Venezuela

Guevara, Armando; de Waard, Jacobus; Araque, María
2009-08-01

Resumen en español Se estudiaron 10 cepas de Pseudomonas aeruginosa con resistencia a cefalosporinas y carbapenémicos con el objeto de determinar la presencia de genes que median la producción de metalo ß-lactamasas. Estas cepas se aislaron de pacientes con infección nosocomial hospitalizados en la Unidad de Cuidados Intensivos (UCI) del Complejo Hospitalario "Ruiz y Paéz" de Ciudad Bolívar, estado Bolívar, Venezuela, durante el período 2003 - 2006. En todas las cepas se detectó la (mas) actividad de una metalo-enzima, mediante la prueba del sinergismo del doble disco. La amplificación por la reacción de polimerasa en cadena de los genes que codifican para las metalo ß-lactamasas de las familias IMP, VIM y SPM, y su posterior secuenciación, permitió confirmar la presencia de metalo p-lactamasas de tipo VIM-2. Estos resultados sugieren que es necesario mantener bajo vigilancia epidemiológica a estas cepas, establecer estrategias de laboratorio para su detección oportuna e implementar nuevas políticas que aseguren el uso adecuado de los antibacterianos en esta institución Resumen en inglés Ten Pseudomonas aeruginosa strains with resistance to broad-spectrum cephalosporin and carbapenems were studied to determine the presence of genes that mediate the productionof metallo-p-lactamases. These strains were isolated from patients with nosocomial infection at the Intensive Care Unit of the Complejo Hospitalario "Ruiz y Paéz" of Ciudad Bolívar, Bolívar State, Venezuela, from 2003 to 2006. In all isolates a metallo-enzyme activity was detected by using the doub (mas) le disk synergism test. PCR amplification of genes encoding the families IMP, VIM and SPM metallo-ß-lactamases showed the presence of a blaVIM gene in all strains studied. DNA sequencing revealed that all isolates showed the presence of blaVIM-2These results suggest that it is necessary to keep these strains under epidemiologic surveillance, establish laboratory strategies for opportune detection and the imple-mentation of new policies to ensure the appropriate use of antibiotics in this institution

Scientific Electronic Library Online (Spanish)

10

Sensibilidad de cepas de Pseudomonas aeruginosa frente a beta-lactámicos/ Beta-lactams susceptibility in Pseudomonas aeruginosa strains

González Rizo, Aileen; Salazar Rodríguez, Daniel; López Sierra, Odalis; Barrios Martínez, Zoyla; Martínez Izquierdo, Alicia
2007-03-01

Resumen en español Los pacientes portadores de enfermedad fibroquística presentan manifestaciones respiratorias a repetición o crónicas, las cuales se acompañan de infecciones bacterianas. Pseudomonas aeruginosa es la especie bacteriana que se aísla con mayor frecuencia en estos pacientes a partir de muestras de origen respiratorio. Teniendo en cuenta que las infecciones por esta bacteria son difíciles de tratar y que la terapia usualmente empleada es la combinación de un aminoglucó (mas) sido con un antibiótico beta-lactámico, se analizó el comportamiento por el método de microdilución en caldo de 54 cepas aisladas de pacientes con fibrosis quística frente a cuatro beta-lactámicos (carbenicilina, azlocilina, cefotaxima, ceftazidima), y se observó que el 85% de las cepas fueron sensibles a ceftazidima, 83% a azlocilina, 37% sensibles a carbenicilina, y solamente un 20% de las cepas estudiadas fueron sensibles a cefotaxima. Los resultados evidencian que ceftazidima continúa siendo un beta-lactámico de elección en el tratamiento de las infecciones causadas por Pseudomonas aeruginosa en pacientes con fibrosis quística. Resumen en inglés Repetitive or chronic respiratory infections are common in cystic fibrosis patients, usually due to Pseudomonas aeruginosa. The recommended therapy is the combination of one aminoglycoside with a beta-lactam antibiotic. For this reason, the susceptibility of 54 Pseudomonas aeruginosa isolated obtained from the respiratory tract of cystic fibrosis patients to four beta-lactams was analysed. The study was performed by broth microdilution. Ceftazidime was the most active age (mas) nt against Pseudomonas aeruginosa (85% of the total strains being susceptible).. Eighty three percent of the strains were inhibited by azlocillin and 37% by carbenicillin. Only 20% of all studied strains were susceptible to cefotaxime.

Scientific Electronic Library Online (Spanish)

11

Conservación de cepas vacunales de Leptospira en nitrógeno líquido/ Preservation for vaccinal strains of Leptospira at liquid nitrogen

Borrero Maura, Reinier; Batista Santiesteban, Niurka; Blain Torres, Kirenia; Valdés Abreu, Yolanda
2010-08-01

Resumen en español INTRODUCCIÓN: las cepas de Leptospira interrogans que integran la vacuna cubana vax-SPIRAL® son conservadas en medio semisólido de Fletcher, el cual garantiza el mantenimiento de la viabilidad de las células por pocos meses. OBJETIVO: en este estudio, se evaluó la crioconservación en nitrógeno líquido de 6 variantes de crioprotectores como método de conservación a largo plazo de las cepas de Leptospira interrogans, utilizadas como antígenos en la vacuna antilep (mas) tospirósica vax-SPIRAL®. MÉTODOS: la viabilidad se evaluó periódicamente según el rendimiento celular alcanzado por las cepas recién descongeladas en medio EMJH. La estabilidad de la virulencia fue estimada en hámster. La antigenicidad antes y después de la crioconservación fue comparada mediante microaglutinación, frente a una batería de antisueros de referencia correspondientes a los serogrupos vacunales. RESULTADOS: solo el empleo de dimetilsulfóxido a 2,5 y 5 %, y glicerol 2,5 % como agentes crioprotectores permitió una rápida recuperación de las 3 cepas, tras 19 meses de crioconservación sin afectación de su virulencia y antigenicidad. CONCLUSIONES: los resultados obtenidos demuestran la factibilidad de la crioconservación en nitrógeno líquido con un apropiado agente crioprotector, como método de conservación de cepas vacunales de Leptospira. Resumen en inglés INTRODUCTION: Leptospira interrogans strains of Cuban vaccine vax-SPIRAL®are preserved in Fletcher's semi-solid medium, which guarantees the preservation of the cell viability for a few months. OBJECTIVE: to evaluate the cryopreservation at liquid nitrogen of 6 different cryoprotectors as a long-term preservation method for Leptospira interrogans strains used as antigens in vaccine vax-SPIRAL® against leptospirosis. METHODS: viability was systematically evaluated accord (mas) ing to the cell yield of the recently thawed strains in EMJH medium. Virulence stability was estimated in hamsters and antigenicity was evaluated by microscopic agglutination test using reference antisera from vaccinal serogroups. RESULTS: the use of 2.5% and 5% dimethyl sulfoxide, and 2.5% glycerol allowed quick recovery of the three strains without virulence or antigenicity depletion after 19 months of cryopreservation. CONCLUSIONS: the results showed the feasibility of the cryopreservation at liquid nitrogen using suitable cryoprotectant as a preservation method for vaccinal strains of Leptospira.

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12

Antagonismo in vitro de cepas de Aspergillus y Trichoderma hacia hongos filamentosos que afectan al cultivo del ajo/ In vitro antagonism of Aspergillus and Trichoderma strains against garlic-pathogenic filamentous fungi

Quiroz-Sarmiento, Vivian Francisca; Ferrera-Cerrato, Ronald; Alarcón, Alejandro; Lara Hernández, María Encarnación
2008-06-01

Resumen en español El presente trabajo evaluó la capacidad antagónica de 22 cepas de hongos filamentosos hacia Penicillium sp. y Fusarium spp. que afectan al cultivo del ajo, mediante enfrentamientos in vitro. Tanto las cepas patógenas como las antagonistas fueron aisladas de la rizósfera y/o material vegetativo de plantas maduras de ajo recolectadas de Celaya, Guanajuato. De las 22 cepas probadas, ocho contribuyeron en la inhibición del crecimiento de los patógenos, seis de las cuale (mas) s correspondieron a Aspergillus nidulans, A. ochraceus (2 cepas), A. wentii (2 cepas) y A. niger, y las dos cepas restantes correspondieron al género Trichoderma sp. Los principales mecanismos de acción identificados en la inhibición del crecimiento de las colonias de los hongos patógenos fueron el micoparasitismo, la antibiosis y la competencia. Los daños causados a las estructuras de los patógenos por los hongos antagónicos variaron según la cepa del antagonista. En general, los antagonistas causaron agrupamiento, deformación y lisis de conidios, así como deformación, lisis y enrollamiento de micelio de los patógenos. Resumen en inglés This research focused on studying the antagonistic capability of 22 strains of filamentous fungi to Penicillium sp. and Fusarium spp. garlic pathogens, via in vitro confrontation. Either pathogen or antagonist strains were isolated from the rhizosphere or vegetative organs of garlic mature plants collected from Celaya, Guanajuato. Eight out of 22 fungal strains inhibited the growth of the pathogens; six of them belonged to Aspergillus species: A. nidulans, A. ochraceus (2 (mas) strains), A. wentii (2 strains), and A. niger, and the remaining two strains belonged to the genus Trichoderma spp. Mycoparasitism, antibiosis, and competition were the main mechanisms by which the fungal strains inhibit the growth of Penicillium and Fusarium. There were variations among antagonists to attack the pathogens and their fungal structures. In general, antagonists caused grouping, deformation, and lysis on conidia, as well deformation, lysis, and winding on mycelia of the pathogens.

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Capacidad probiótica de cepas del género Lactobacillus extraídas del tracto intestinal de animales de granja/ Probiotic Properties of Strains of Lactobacillus Genus Extracted from Intestinal Tract of Farm Animals

Ávila, José; Ávila, Manuel; Tovar, Belkis; Brizuela, María; Perazzo, Yurimaua; Hernández, Helis
2010-03-01

Resumen en español Se aislaron y caracterizaron 14 cepas bacterianas del tracto intestinal de diferentes animales de granja con el fin de seleccionar las cepas con potencial probiótico. Las cepas seleccionadas fueron sometidas a pruebas bioquímicas y además se evaluó su capacidad probiótica mediante pruebas de resistencia al ácido y a las sales de bilis, crecimiento a temperaturas extremas y perfil de fermentación de carbohidratos. Los resultados permitieron la selección e identific (mas) ación de cuatro cepas de Lactobacillus con potencial para ser utilizados como aditivos probióticos en la alimentación animal. Resumen en inglés In the present work 14 bacterial strains were isolated and characterized from the intestinal tract of different farm animals, in order to select the strains whit probiotic potential. The selected strains were exerted to biochemical trails and also their probiotic properties were evaluated through acid resistance and bile salt trials, extreme temperature growth and the carbohydrate fermentation profile. The results allowed selection and identification of four lactobacillus strains with potential to be used as probiotic additives in animal feeding.

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Mutaciones en genes gyrA y gyrB en cepas de bacilos Gram negativos aisladas en hospitales chilenos y su relación con la resistencia a fluoroquinolonas/ Mutations in gyrA and gyrB genes among strains of Gram-negative bacilli isolated from Chilean hospitals and their relation with resistance to fluoroquinolones

De la Fuente C, Mery; Dauros S, Priscila; Bello T, Helia; Domínguez Y, Mariana; Mella M, Sergio; Sepúlveda A, Marcela; Zemelman Z, Raúl; González R, Gerardo
2007-09-01

Resumen en inglés Background: A progressive frequency of resistance to fluorquinolones is observed among Gram-negative bacilli. Aim: To investigate the mechanism of resistance to fluoroquinolones mediated by mutations affecting gyrA and gyrB genes in strains of Gram negative bacüli isolated from CMean hospitals. Material and method: Minimal inhibitory concentration of fluoroquinolones was determined in 91 randomly selected nalidixic acid-resistant strains of Escherichia coli, Klebsiella p (mas) neumoniae, Acinetobacter baumannii and Pseudomonas aeruginosa, isolated from hospitals of 12 Chilean cities. Quinolone resistance determining region (QRDR) was amplified by PCR and mutations were determined by restriction fragment length polymorphism (RFLP) and DNA sequencing. Results: Strains with mutation in codon 83 of gyrA showed decreased susceptibility to ciprofloxacin with MICs ranging from 0.25 to 1024 fig/ml. The sequencing of PCR products for gyrA indicated amino acid changes in the QRDR region. One strain ofE. coli presented a double mutation, in codon 83 Ser to Leu as well as in codon 87 Asp to Asn. In strains ofK. pneumoniae, however, the change of codon 83 was Ser to Tyr, in A. baumannii was Ser to Leu and in P. aeruginosa was Thr to He. No strains with mutations affecting gyrB were found. Conclusions: Mutations in codon 83 of gyrA is a frequent genetic event involved in the mechanism leading to decreased susceptibility to fluoroquinolone in strains of Gram-negative bacilli

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Factores de virulencia en cepas de Aeromonas aisladas de pacientes con enfermedad diarreica aguda en Cuba/ Virulence factors in Aeromonas strains isolated from patients with acute diarrheas in Cuba

Bravo Fariñas, Laura; San Germán Suárez, Susana; Fernández Abreu, Anabel; Ramírez Álvarez, Margarita; Morier Díaz, Luis; Fernández Andreu, Carlos; Cabrera Rodríguez, Luis E.; Castro Escarpulli, Graciela; Ledo Ginarte, Yudith; Correa Martínez, Yusleidy; Núñez Fernández, Fidel; Cruz Infante, Yanaika
2008-08-01

Resumen en español Objetivo: se realizó un estudio en cepas de Aeromonas aisladas de pacientes con enfermedad diarreica aguda en Cuba, para conocer la expresión fenotípica de la citotoxina y la enterotoxina como factores de virulencia. Métodos: se investigaron 46 cepas (A. hydrophila, A. veronii biovar sobria, A. caviae, A. veronii biovar veronii y Aeromonas spp.), aisladas de heces de pacientes con enfermedad diarreica aguda, en el período comprendido entre 2005 y 2006. Todas las cepa (mas) s tenían identificado su patrón de susceptibilidad antimicrobiana. Se comprobó la expresión fenotípica de la citotoxina y la enterotoxina en la línea celular Vero. Resultados: el estudio demostró que 91,31 % de las cepas mostraron actividad citotóxica y 43,48 % actividad enterotóxica. De las cepas multirresistentes, 93,75 % presentó al menos un factor de virulencia estudiado. Conclusiones: los resultados demostraron que los 2 factores de virulencia investigados estuvieron presentes en las cepas estudiadas, contribuyendo así a los múltiples esfuerzos que se realizan para conocer los mecanismos de enteropatogenicidad de este género bacteriano. Resumen en inglés Objective: A study was carried out in Aeromonas strains isolated from patients with acute diarrheas in Cuba to find out the phenotypical expression of the cytotoxin and the enterotoxin as virulence factors. Methods: Forty six strains of the genus Aeromonas (A. hydrophila, A. veronii bv sobria, A. caviae, A. veronii bv veronii and Aeromonas spp.) isolated from stool specimens taken form patients with acute diarrheal disease were studied from 2005 to 2006. All the strains h (mas) ad their pattern of antimicrobial susceptibility pattern identified. The phenotypic expression of the cytotoxin and the enterotoxin in the Vero cell line was checked. Results: It was demonstrated that 91,31 % of the strains showed cytotoxic activity and 43,48 % of them enterotoxic activity. Regarding multiresistant strains, 93,75 % presented with at least one of the studied virulence factors. Conclusions: these results proved that the two researched virulence factors did exist in the studied strains, thus contributing to the many efforts that are being made to learn about the mechanisms of enteropathogenicity of this bacterial genus.

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Susceptibilidad a penicilina en cepas de Streptococcus pneumoniae aisladas en el Hospital de Puerto Montt, 1995-2003/ Penicillin susceptibility in Streptococcus pneumoniae strains isolated at Puerto Montt Hospital between 1995 and 2003

Rioseco Z, María Luisa; Riquelme O, Raúl
2006-02-01

Resumen en inglés Background: The emergence and dissemination of resistance to penicillin among Streptococcus pneumoniae changed the approach to empiric antimicrobial therapy. Aim: To evaluate the in vitro susceptibility to penicillin in all S. pneumoniae strains isolated in Puerto Montt Hospital between 1995 and 2003. Material and methods: We revised all Microbiology Laboratory files of this period. Identification and antimicrobial susceptibility study methods for S pneumoniae did not cha (mas) nge during the study period. Results: Six hundred eighteen S pneumoniae strains were identified. Of these, 66% came from adults and 48% from invasive diseases. Only 1.9% of strains were penicillin resistant and 7.6% had intermediate sensibility. Strains isolated from children and those isolated from non sterile sources had non significantly higher resistance levels. The susceptibility did not change along the years of the study. Conclusions: Among S pneumoniae strains isolated at Puerto Montt Hospital, the prevalence of penicillin resistance is low

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Aislamiento y caracterización de cepas silvestres de Sporotrhix schenkii e investigación de reactores a la Esporototicina/ Isolation and Characterization of Wild Sporothrix schenkii Strains and Investigation of Sporototrichin Reactors

Sánchez-Alemán, Miguel Ángel; Araiza, Javier; Bonifaz, Alexandra
2004-10-01

Resumen en español Se llevó a cabo un estudio en la sierra sur de Oaxaca de aislamiento de cepas silvestres de Sporothrix schenckii a partir de muestras de tierra, así como investigación de reactores positivos a la intradermorreacción con Esporotricina. El estudio se llevó a cabo a partir de la recolección de muestras de tierra y su posterior procesamiento mediante métodos de dilución y aislamiento del hongo en medios habituales de cultivo de Sabouraud simple y Sabouraud con antibi� (mas) �ticos (SS y SA). Las cepas presuntivas se sometieron apruebas de dimorfismo, formación de melanina y comprobación de virulencia en animales. Se investigaron los reactores positivos a la Esporotricina L (Levaduriforme). Se identificaron tres cepas presuntivas por sus características reproductivas, formación demelanina y capacidad virulenta. En la comunidad se investigaron a 144 individuos dando positivos a la Esporotricina L el 6.25%. Se comprueba el aislamiento de cepas virulentas de S. schenckii a partir de la naturaleza (suelo) y se comprueba primocontacto con éste en un porcentaje de la población estudiada. Resumen en inglés We conducted a study in the southern mountains of the Mexican State of Oaxaca that consisted of isolation of wild Sporothrix schenckii strains obtained from soil samples and investigation of positive reactors to skin test reaction with sprotrichin antigen. The study was conducted by means of recollection of soil samples and processing of these with dilution methods and fungal isolation in ordinary culture media Sabouraud simple Agar with and without antibiotics (SS, SA). (mas) Suspected strains underwent dimorfism, melanin formation, and virulence confirmation tests. Investigation of positive reactors to sporotrichin Y (yeast) was also conducted. Three supposed strains were identified due to their reproductive characteristics, melaninproduction, and virulence. In the community; 144 individuals were studied, ofwhom6.25%werepositivetosporotichin. Isolation of virulent strains o/Sporotrhix schenkii from nature (soil) andprimoinfection of a percentage of the studied population were confirmed.

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Evaluación higiénico-sanitaria y acción antagónica de cepas de lactobacilos comerciales frente a microorganismos patógenos (escherichia coli) presentes en el queso de capa del municipio de mompox/ Higienic-sanitary evaluation and antagonistic action of strains of commercial lactobacillus in front to the pathogen microorganism (escherichia coli ) present in the cheese of layer of the municipality of mompox

Durán Lengua, Marlene; Montero Castillo, Piedad; Flórez Díaz, Wilfrido; Franco de la Hoz, Vicenta; Coneo Rodríguez, Rusbel
2010-06-01

Resumen en español El objetivo de este trabajo fue evaluar la calidad higiénica del queso de capa del municipio de Mompóx en el departamento de Bolívar, Colombia y la capacidad bactericida de Lactobacillus spp aislados de un producto comercial (yogurt). Se tomaron 16 muestras de 200 g en cuatro sitios de fabricación del queso de capa, entre abril y noviembre del 2006; fueron empacadas en bolsas estériles y trasladadas en nevera de icopor con hielo hasta el laboratorio de Microbiología (mas) de Alimentos de la Universidad de Cartagena, allí se evaluó la carga microbiana de mesófilos aerobios, coliformes totales, coliformes fecales, E. coli y Salmonella. Este estudio arrojó un promedio de mesófilos aerobios 1,5×10(8), de coliformes totales 2,5×10³; se confirmó la presencia de E. coli y la ausencia de Salmonella, así como de cepas ácido lácticas en las muestras estudiadas. En general, los recuentos microbiológicos sobrepasan los valores establecidos por la legislación colombiana. Por otro lado, la evaluación de actividad antagónica de Lactobacillus comerciales fue demostrada frente a las cepas de E. coli aisladas. Resumen en inglés The aim of this study was to assess the hygienic quality of the cheese layer in the Mompox Municipality in the Department of Bolivar, Colombia, and the bactericidal capacity of the Lactobacillus spp isolated from a commercial product (yogurt). Sixteen cheese layer samples of 200g each were taken from four manufacturing sites between April and November of 2006, the samples were packed in sterile bags and transported with ice in polystyrene to the laboratory of food Microbi (mas) ology at the University of Cartagena, the university assessed the microbial of aerobic mesophiles total coliforms, fecal coliforms, E. coli and salmonella. This study threw an average of aerobic mesophiles 1.5×10(8), of total coliforms 2.5×10³; confirmed the presence of E. coli and the absence of Salmonella, as well as strains of lactic acid in the samples studied. In general, microbial counts exceed the levels established by Colombian legislation. Furthermore, assessment of antagonistic activity of commercial Lactobacillus was demonstrated against isolated strains of E. coli.

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Perfil serológico y antibiotipia de cepas de Streptococcus pneumoniae aisladas de portadores nasales pediátricos./ Serotype profile and antibiotyping of Streptococcus pneumoniae strains isolated from nasal carriage in pediatric patients.

Quintero, Beatriz; Araque, María
2006-03-01

Resumen en español El objetivo de este trabajo fue determinar el perfil serológico y la antibiotipia de S. pneumoniae aislados de portadores nasales pediátricos. Ciento veinticinco muestras de secreción nasal provenientes de niños fueron cultivadas y estudiadas para detectar la presencia de Streptococcus pneumoniae. Las cepas fueron identificadas según métodos microbiológicos estandarizados, la serotipificación por la reacción de Quellung y los patrones de resistencia por el métod (mas) o de microdilución de acuerdo al National Committee for Clinical Laboratory Standards. Los resultados indicaron que la frecuencia de aislamiento de neumococos en la región nasal fue de 24% (n=30), y los serotipos más comúnmente identificados fueron el 23F (20%), el 6B (20%) y el 14 (13%). El 73% de los aislados fueron resistentes por lo menos a uno de los antibióticos probados. El 47% de las cepas mostraron resistencia a la penicilina y los serotipos más frecuentemente asociados a este marcador fueron el 6B y el 23F. El 60% de las cepas mostró resistencia a la doxiciclina, el 37% al trimetoprim/sulfametoxasol y a la clindamicina, el 30% a eritromicina, el 23% al cloramfenicol, el 7% a ceftriaxona y el 3% a cefepima. Todas las cepas fueron sensibles a la ofloxacina, rifampicina y vancomicina. Los patrones de multirresistencia más comunes fueron PNC-ERI-TMP/SMX-DOX-CLO-CLI (16,59%) y PNC-DOX (13,27%). Los resultados obtenidos en este estudio permitirán orientar la terapia empírica para las infecciones neumocócicas y el uso racional de los antibióticos en la práctica clínica, así como la aplicación de un programa de vacunación adaptado a los serotipos más frecuentemente encontrados en la población infantil. Resumen en inglés The aim of this study was to determine the serotype profile and antibiotyping of Streptococcus pneumoniae from nasal isolates in children. Nasopharyngeal swab samples obtained from 125 children were cultivated and screened for the presence of S. pneumoniae. Strains were identified according to standard microbiological methods. The isolates were serotyped by the Quellung reaction and resistance patterns were determined by the microdilution method according to NCCLS guideli (mas) nes. Results indicate an overall pneumococcal carriage rate of 24% (n=30). The most commonly isolated serotypes were 23F (20%), 6B (20%) and 14 (13%). 73% of isolates were resistant at least to one of the tested antibiotics. 47% of the strains were consistently resistant to penicillin and the serotypes 6B and 23F were frequently associated with this marker. 60% of the strains were resistant to doxycycline, 37% to trimethoprim/sulfamethoxazole and clindamycin, 30% to erythromycin, 23% to cloramphenicol, 7% to ceftriaxone and 3% to cefepime. All strains were sensible to ofloxacin, rifampin and vancomycin. The most common combined resistance patterns were PNC-ERI-TMP/SMX-DOX-CLO-CLI (16.59%) and PNC-DOX (13.27%). The results obtained in this study will allow to orient the empiric therapy for pneumococcal infections and a rational use of antibiotics in clinical practice, as well as the application of an appropriate vaccination program specially adapted to the serotypes more frequently found in children.

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Estudio molecular de cepas argentinas de Bacillus anthracis/ Molecular study of Argentine strains of Bacillus anthracis

Pavan, M. E.; Cairó, F.
2007-06-01

Resumen en español Bacillus anthracis es una de las bacterias más monomórficas conocidas y los estudios epidemiológicos de este microorganismo se han visto dificultados por la falta de marcadores moleculares. El objetivo de este trabajo fue caracterizar molecularmente catorce cepas de campo argentinas y la cepa vacunal Sterne 34F2 sobre la base del estudio del locus vrrA, que contiene una repetición en tándem de número variable (VNTR) y presenta un polimorfismo con cinco variantes. Ta (mas) mbién se ha tenido en cuenta la presencia o ausencia de los plásmidos de virulencia. Las cepas fueron aisladas de vacas, ovejas y cerdos durante brotes ocurridos en Buenos Aires, Entre Ríos, Santa Fe y La Pampa durante los últimos cincuenta años. Todas las cepas de campo presentaron los plásmidos pXO1 y pXO2, con excepción de una cepa aislada de cerdo que únicamente presentó el plásmido pXO2. Todos los aislamientos y la cepa vacunal pertenecieron a la misma variante molecular de VNTR, que se definió secuenciando el locus vrrA de tres de los aislamientos y de la cepa 34F2. Estas secuencias fueron completamente idénticas y correspondieron a la variante VNTR4; así, las catorce cepas argentinas de B. anthracis estudiadas mostraron una gran uniformidad a nivel molecular, aun cuando se habían aislado de diferentes especies de mamíferos, en un amplio período de tiempo y en una extensa zona geográfica. Resumen en inglés Bacillus anthracis is one of the most monomorphic bacteria known and epidemiological studies of this microorganism have been hampered by the lack of molecular markers. For the genotyping of fourteen Argentine field strains and the vaccine strain Sterne 34F2, the presence or absence of the virulence plasmids as well as vrrA locus containing a variable-number tandem repeat (VNTR) and presenting a polymorphism involving five variants, were analyzed. Strains were isolated fro (mas) m cows, sheep and pigs during outbreaks occurred in Buenos Aires, Entre Ríos, Santa Fe and La Pampa in the past fifty years. All of the field strains presented plasmids pXO1 and pXO2, except for a strain isolated from pig that only presented plasmid pXO2. All the strains and the vaccine strain belonged to the same VNTR variant that was defined by sequencing the vrrA locus from three of the isolates and the strain 34F2. These sequences were completely identical and corresponded to the variant VNTR4. Thus, the fourteen Argentine B. anthracis strains studied showed great uniformity at molecular level even though they had been isolated from different mammal species within a wide time period and covering an extensive geographical area.

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Susceptibilidad a antibióticos de cepas paraguayas de Helicobacter pylori aisladas de pacientes con enfermedad gastro-duodenal/ Antimicrobial susceptibility of H pylori strains obtained from Paraguayan patients

Fariña, Norma; Kasamatsu, Elena; Samudio, Margarita; Morán, Miryam; Sanabria, Rosa; Laspina, Florentina
2007-08-01

Resumen en inglés Background: Antimicrobial resistance is one of the main obstacles for an effective eradication of H. pylori infection. Aim: To determine the susceptibility of H. pylori strains obtained from gastric biopsies to metronidazole, clarithromycin and amoxicillin. Material and methods: Susceptibility to metronidazole, clarithromycin and amoxicillin was determined using E-test in 46 isolates ofH. pylori obtained from gastric biopsies of 54 adult patients. Results: Thirty three pe (mas) rcent of isolates were resistant to metronidazole and 2% were resistant to clarithromycin and amoxicillin. One isolate was resistant to metronidazole and clarithromycin. Conclusions: The antimicrobial susceptibility of these strains ofH. pylori obtained from Paraguayan patients, may help to decide the initial therapy to eradicate this infection (RevMéd Chile 2007; 135:1009-14)

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Resistencia a antimicrobianos en cepas de Enterococcus sp aisladas en hospitales del norte de Chile/ Resistance to antimicrobial drugs in Enterococcus sp strains isolated in hospitals of Northern Chile

Silva A, Juan; Asserella R, Leyla; Bolados G, Nury; Herrera H, Nelson; Leyton O, Johanna
2006-09-01

Resumen en español Se estudió la prevalencia de diferentes especies de Enterococcus y su resistencia a antimicrobianos en cepas aisladas en 5 hospitales del norte de Chile. Un total de 249 cepas de Enterococcus spp fueron incluidas en el estudio. Las principales fuentes de obtención fueron muestras de orinas y heridas operatorias. Se identificaron 5 especies de Enterococcus, siendo E. faecalis y E. faecium las especies aisladas con mayor frecuencia en todos los hospitales. Se observó una (mas) alta susceptibilidad a los antimicrobianos β-lactámicos, resistencia moderada a tetracilina, ciprofloxacina y eritromicina, y resistencia elevada a cloranfenicol. No se detectó resistencia a vancomicina y aproximadamente, 12% de las cepas de Enterococcus sp presentó resistencia a altas concentraciones de gentamicina. En 30% del total de las cepas de Enterococcus estudiadas se observó resistencia a 3 y más antimicrobianos Resumen en inglés The prevalence of different species of Enterococcus and the resistance to antimicrobial drugs was studied in strains isolated in 5 hospitals of Northern Chile. A total of 249 of Enterococcus spp strains were included in this study. Enterococci were mostly isolated from urine and wounds. Among five species identified, E. faecalis and E. faecium were most frequently isolated in the all hospitals. High susceptibility to beta-lactam antibiotics, moderate resistance to tetracy (mas) cline, ciprofloxacin and eritromycin, and high resistance to chloramphenicol was observed. Vancomycin resistance was absent. Approximately 12% of Enterococcus spp strains presented high level of gentamicin resistance. Multiresistance to 3 o more antimicrobial agents was detected in 30% of total Enterococcus strains studied

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Fenotipos bioquímicos y fagotipos de cepas de Salmonella enteritidis aisladas en Antofagasta, 1997-2000/ Biochemical phenotypes and phage types of Salmonella enteritidis strains isolated in Antofagasta during the period 1997-2000

Silva A, Juan; Aravena M, Carmen; Araya R, Jorge; Colque-Navarro, Patricia; Kühn, Inger; Möllby, Roland
2003-08-01

Resumen en inglés PhP-S48 (Phene Plate Techniques AB), a method based on biochemical phenotypes has been developed and used successfully to typify S enteritidis strains in epidemiological studies. Aim: To identify phenotypes of S enteritidis isolated from eggs, chicken meat and infected humans in Antofagasta during the period 1997-2000. Material and Methods: PhP-S48 and phage typing were used to identify phenotypes of 33 S enteritidis strains, sixteen isolated from poultry and 17 from clin (mas) ical sources. S enteritidis ATCC17036 was used as control strain. Results: Twelve biochemical phenotypes (BTs) including 4 common (C) and 8 single (S) were identified. BTs C1 y C3 containing 16 and 5 strains, respectively, accounted for 63.6% of the isolates. BT C1 was found in poultry and human sources in the period 1997-2000, and BT C3 was isolated from humans, in the period 1999-2000. Using phage typing, 5 phage types (PT) and 3 strains could be not typed (NTs). PT1 and PT21 were the dominant phage types, with 14 and 13 strains respectively. Strains of PT1 were isolated from poultry and human sources in the period 1997-2000. PT21 was found in poultry samples in the period 1997-1998 and in clinical samples, in the period 1997-1998. Combination of biochemical phenotypes and phage typing divided the strains into 5 phenotypes (BT:PT). Two phenotypes were the most frequently isolated, phenotype C1:1 with 8 isolates found in eggs and humans in 1999, and phenotype C1:21 with 5 strains isolated in 1997-1999. Conclusions: These results indicate the presence of one persistent and one recently emerged phenotype among S enteritidis in Antofagasta, Chile. PhP-S48 also provided information about a relationship among the strains (Rev Méd Chile 2003; 131: 837-45)

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Secuencias de inserción IS6110 e IS1081 en cepas de Mycobacterium bovis provenientes de bovinos beneficiados en la Región Metropolitana/ Insertion sequences IS6110 and IS1081 present in strains of Mycobacterium bovis from cattle slaughtered at the Metropolitan Area, Chile

RETAMAL M, PATRICIO; MARTÍNEZ T, M. ANGÉLICA; ABALOS P, PEDRO
2003-01-01

Resumen en español La tuberculosis constituye uno de los principales problemas de salud pública en el mundo. Varios estudios han comunicado la utilidad de la técnica de fingerprint con las secuencias de inserción (IS) 6110 e IS1081 para la identificación y tipificación de cepas del complejo Mycobacterium tuberculosis. Ambas secuencias son específicas de las especies bacterianas que pertenecen a este complejo, pero su presencia y número de copias varía entre cepas de M. tuberculosis (mas) y M. bovis. El objetivo de nuestro estudio fue investigar la presencia de las secuencias IS6110 e IS1081 en nueve cepas de Mycobacterium bovis aisladas de los ganglios mediastínicos de bovinos beneficiados en mataderos de Santiago de Chile. Se detectó la presencia de IS1081 en todas las cepas, mientras que IS6110 sólo fue detectada en 7 de ellas. Los resultados de este estudio sugieren la utilidad potencial de IS1081 para ser aplicada en la tipificación de cepas de M. bovis. La secuencia IS6110 podría constituir un marcador genético adicional en las cepas que contengan este elemento. Se requiere continuar la caracterización de estas secuencias de inserción con técnicas de genotipificación en que se incluya un mayor número de muestras, de distintas especies animales y provenientes de distintas zonas geográficas, a fin de generar información epidemiológica útil en futuros programas de control de la enfermedad Resumen en inglés Tuberculosis remains one of the major world health problems. Several studies have established the usefulness of insertion sequence (IS) IS6110 and IS1081 fingerprinting for the identification and typing of strains from the Mycobacterium tuberculosis complex. Both sequences are specific of bacteria belonging to this complex, but the number of copies can be variable among different M. tuberculosis and M. bovis strains. The aim of our study was to survey the presence of the (mas) insertion sequences IS6110 and IS1081 in nine strains of Mycobacterium bovis isolated from the mediastinal lymph nodes of cattle slaughtered in Santiago, Chile. All the strains contained IS1081, whereas only seven of them contained the IS6110 sequence. These results suggest the potential use of IS1081 for the differentiation by RFLP analysis of M. bovis strains. IS6110 may constitute an additional genetic marker for typing strains containing this element. It is recommended the characterization of this insertion sequences with genotyping assays, with higher sample sizes, more animal species and from different geographical areas to obtain useful epidemiological information in further control programs of the disease

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Detección y caracterización molecular de cepas variantes del virus de la enfermedad infecciosa de la bolsa en el Estado Zulia, Venezuela/ Molecular detection and characterization of infectious bursal disease virus variant strains from Zulia State, Venezuela

Oviedo, Ana; García, Elita; Mavarez, Yaneth; Gil, Marcelo; Arzalluz-Fischer, Ana; Perozo, Francisco
2010-02-01

Resumen en español Las cepas clásicas del virus de la enfermedad infecciosa de la bolsa (por sus siglas en inglés IBDV) están presentes en la industria avícola venezolana desde el último tercio del siglo pasado, a pesar de la implementación de programas intensivos de vacunación. Recientemente, se ha reportado la presencia de cepas variantes del IBDV en varios países de Latinoamérica. El presente trabajo reporta la identificación, mediante técnicas moleculares, de cepas variantes (mas) en granjas avícolas venezolanas. En parvadas de pollos de engorde de cuatro semanas de edad se tomaron bolsas de Fabricio e improntas en la tarjeta Whatman Indicadora Clásica FTA® para evaluación histopatológica y detección molecular, respectivamente. Para la caracterización molecular se utilizó la prueba de reacción en cadena por la polimerasa-transcriptasa reversa (por sus siglas en inglés RT-PCR) acoplada a secuenciación directa de nucleótidos. El peso vivo del ave, el índice peso bolsa/peso corporal, así como el peso y diámetro de la bolsa se consideraron como indicadores de inmunocompetencia a la cuarta semana. Todas las aves muestreadas (n=113) resultaron positivas a IBDV. Los virus provenientes de 10 de las 13 granjas mostraron alta similitud con cepas variantes (A y E). En concordancia con los resultados de RT-PCR, los hallazgos histopatológicos mostraron lesiones relacionadas con IBDV. Los indicadores morfológicos de inmunocompetencia se afectaron significativamente en las granjas donde se detectaron cepas variantes. En Venezuela no se utiliza vacuna viva contra cepas variantes, lo que incrementa el riesgo de inmunosupresión, fallas en los programas de vacunación y la susceptibilidad a enfermedades endémicas. Resumen en inglés Classical infectious bursa disease virus (IBDV) has been present in the Venezuelan poultry industry since the last quarter of the past century despite intensive vaccination programs applied to control the disease. Lately, the presence of variant strains has been reported in several Latin-American countries. This work reports the molecular identification of variant IBDV strains in poultry farms from Venezuela. Bursal imprints in Whatman classic indicator FTA® cards and bu (mas) rsa tissues for histopathological analysis were collected from 4-week old broiler flocks. Reverse transcriptase polymerase chain reaction (RT-PCR) and direct nucleotide sequence were used for the virus molecular characterization. The bird´s body weight, the bursal index, the bursa weight and diameter were used to assess the immune status at four weeks of age. All the birds sampled (n =113) were IBDV positive. Viruses from 10 out of 13 farms showed high similarity with the IBDV variant strains (variants A and E). Histopathological findings where consistent with the RT-PCR, results showing IBDV related bursa damage in the infected birds. The immune status indicators were significantly affected in the farms where variant strains were detected. No variant strain live vaccination is currently used in Venezuela, increasing the risk of immunossupression, vaccine failure and susceptibility to endemic diseases.

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Variaciones fenotípicas de susceptibilidad en cepas de Klebsiella pneumoniae de origen nosocomial y su asociación con la formación de biopelículas/ Phenotipic variations of susceptibility in Klebsiella pneumoniae strains of nosocomial origin and their association with biofilms formation

Barreto, Silvio; Zambrano, María; Araque, María
2009-06-01

Resumen en español Klebsiella pneumoniae constituye uno de los principales patógenos oportunistas asociado con infecciones nosocomiales. La morbi-mortalidad producida por este microorganismo está relacionado en gran parte con la resistencia antimicrobiana y la capacidad de formar biopelículas. En este estudio se analizaron las variaciones fenotípicas de susceptibilidad de 50 cepas de K. pneumoniae (26, productoras de bLEE y 24, no productoras de bLEE) aisladas de pacientes pediátricos (mas) con septicemia nosocomial, recluidos en la Unidad de Alto Riesgo Neonatal del Instituto Autónomo Hospital Universitario de Los Andes, Mérida, Venezuela y su asociación con la formación de biopelículas. Las cepas fueron identificadas según los métodos microbiológicos estandarizados, los patrones de susceptibilidad se determinaron por concentración inhibitoria mínima, y la formación de biopelícula por técnicas espectrofotométricas. La mayoría de las cepas productoras de bLEE se asociaron con frecuencia a otros marcadores de resistencia, tales como: tobramicina, kanamicina, tetraciclina, cloranfenicol (38%, cada uno), estreptomicina (36%), y netilmicina (34%). El fenotipo multirresistente predominante fue el constituido por bLEE+-AMG-TET-CLF (30%). El 18% de las cepas de K. pneumoniae fue sensible a los antibióticos probados. La formación de biopelículas se observó en el 77,8% de las cepas sensibles y en el 96,2% de las resistentes. No hubo relación estadística entre las variaciones fenotípicas de susceptibilidad y la formación de biopelículas (p= >0,05). Sin embargo, ambas características en K. pneumoniae deben ser consideradas en el momento de decidir una conducta terapéutica para el tratamiento de pacientes con infección nosocomial. Resumen en inglés Klebsiella pneumoniae is the principal opportunist pathogen associated with nosocomial infections. The morbidity and mortality produced by this microorganism is related mostly to antimicrobial resistance and its capacity to form biofilms. In this study, the phenotypic variations of susceptibility in 50 Klebsiella pneumoniae strains (26 bLEE-producer and 24 no bLEE-producer) isolated from pediatric patients with nosocomial septicemia at the High-risk Neonatal Unit of the I (mas) nstituto Autónomo Hospital Universitario de Los Andes, Mérida, Venezuela and their associations with biofilm formation were analyzed. These strains were biochemically identified by standard microbiology methods. Antimicrobial susceptibility was determined by minimal inhibitory concentration and biofilm formation was detected by spectrophotometric techniques. Most of bLEE strains were frequently associated with resistance markers such as tobramycin, kanamycin, tetracycline, chloramphenicol (38% each), streptomycin (36%) and netilmicin (34%). The predominant multiresistent phenotype was composed of bLEE+-AMG-TET-CLF (30%). 18% of K. pneumoniae strains were sensible to the antibiotics tested. Formation of biofilm was observed in 77.8% and 96.2% of sensible and resistent strains, respectively. There was no statistic relation between phenotipic variations of susceptibility and biofilm formation (p= >0.05). However, both characteristics of K. pneumoniae should be evaluated to determine the therapeutic conduct to treat patients with nosocomial infection.

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Factores de virulencia de cepas de Enterococcus aisladas de quesos ovinos/ Virulence factors of Enterococcus strains isolated from ovine cheese

Marguet, Emilio Rogelio; Vallejo, Marisol; Olivera, Nelda Lila
2008-12-01

Resumen en español Los enterococos son utilizados en la industria alimenticia como cultivos iniciadores o probióticos y constituyen contaminantes naturales de los alimentos. Sin embargo, el género Enterococcus ha cobrado relevancia como causal de infecciones nosocomiales, tendencia exacerbada por el desarrollo de resistencia antibiótica. Con el objetivo de estudiar la virulencia potencial de ocho cepas de Enterococcus faecium y de dos cepas de Enterococcus faecalis aislados de quesos ovi (mas) nos se investigó la resistencia a vancomicina, la actividad hemolítica y la actividad de gelatinasa. En forma adicional se llevó a cabo la reacción en cadena de la polimerasa (PCR) para determinar la presencia de los genes cylB de la citolisina, gelE de la gelatinasa, cpd de la feromona sexual y agg de la proteína de agregación. Ninguna de las cepas mostró resistencia a la vancomicina o actividad hemolítica. El gen cylB no pudo ser identificado mediante amplificación por PCR en ninguna de las cepas estudiadas. La presencia del gen gelE fue detectada en siete cepas de E. faecium y en una cepa de E. faecalis, sin embargo en ningún caso se detectó actividad de la enzima. El gen cpd fue detectado en E. faecium ETw7 y E. faecalis ETw23, mientras que el gen agg fue hallado en las cepas de E. faecium ETw7 y E. faecalis ETw27. Estos resultados sugieren que la introducción de productos alimenticios o probióticos basados en el uso de cepas de enterococos requiere una cuidadosa evaluación sobre su seguridad. Resumen en inglés Enterococci are used as starter and probiotic cultures in the food industry, and they occur as natural food contaminants. However, the genus Enterococcus is of increased significance as a cause of nosocomial infections, exacerbated by the development of antibiotic resistance. In order to study the potential virulence of eight Enterococcus faecium strains and two Enterococcus faecalis strains isolated from ovine cheese, vancomicine resistance, hemolytic activity and gelati (mas) nase activity were investigated. In addition, polymerase chain reaction (PCR) tests were carried out in order to determine the presence of cytolicyn gene cylB, gelatinase gene gelE, sex pheromone gene cpd and aggregation protein gene agg. None of the strains showed vancomicine resistance or hemolitic activity. Gene cylB could not be identified by PCR amplification in any of the strains studied. The presence of gene gelE was found in seven E. faecium strains and in one E. faecalis strain, however in no case was gelatinase activity detected. Gene cpd was detected in E. faecium ETw7 and E. faecalis ETw23, while gene agg was found in E. faecium ETw7 and E. faecalis ETw27. These results suggest that the introduction of food products or probiotics based on the use of enterococal strains requires careful safety evaluations.

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Resistencia a gentamicina, amikacina y ciprofloxacina en cepas hospitalarias de Klebsiella pneumoniae subespecie pneumoniae productoras de ß-lactamasas de espectro extendido/ Resistance to gentamicin, amikacin and ciprofloxacin among nosocomial isolates of Klebsiella pneumoniae subspecie pneumoniae producing extended spectrum ß-lactamases

Díaz Q, Patricia; Bello T, Helia; Domínguez Y, Mariana; Trabal F, Natalia; Mella M, Sergio; Zemelman Z, Raúl; González R, Gerardo
2004-10-01

Resumen en inglés Background: Klebsiella pneumoniae is a pathogenic bacterium frequently isolated from nosocomial samples, specially the subspecie pneumoniae, with extensive antibiotic resistance profiles, including third generation cephalosporins, aminoglycosides and quinolones. This is specially true for those strains producing extended spectrum beta lactamases (ESBL). Aim: To investigate the susceptibility to gentamicin, amikacin and ciprofloxacin and the presence of some aminoglycoside (mas) modifying enzyme (AMEs) among nosocomial strains of K pneumoniae subspecie pneumoniae producing ESBL. Material and methods: The antibiotic resistant patterns and the level of resistance (minimal inhibitory concentration, MIC) of 100 strains, isolated from several hospitals of different Chilean cities, were determined. The presence of some aminoglycosides modifying enzyme (AMEs) was investigated by PCR. Results: Sixty five percent of strains were resistant to gentamicin, 47% were resistant to amikacin and 29% were resistant to ciprofloxacin. The most frequent AMEs genes detected were the aac(6')-Ib gene (6'-N-Acetyltransferase type Ib enzyme) in 69% of strains, conferring resistance to amikacin, kanamycin, tobramycin, and neomycin, and the gene aac(3)-IIa (3-Acetyltransferase type 3-IIa enzyme), in 36% of strains, conferring resistance to gentamicin. Conclusions: Among nosocomial strains of K pneumoniae subspecie pneumoniae isolated from Chilean hospitals, there is an association between the production of ESBL and the resistance to others antimicrobial agents, especially aminoglycosides. Nevertheless, 71% of isolates are susceptible to ciprofloxacin (Rev Méd Chile 2004; 132: 1173-8)

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Búsqueda de resistencia a amantadina en cepas de virus influenza A aisladas en Santiago de Chile, entre los años 2001 y 2002/ Search of amantadine-resistance in influenza A strains isolated in Santiago, Chile, 2001-2002

Fehlmann P, Elisa; Le Corre P, Nicole; Abarca V, Katia; Godoy M, Paula; Montecinos P, Luisa; Veloz B, Ana; Ferrés G, Marcela
2005-06-01

Resumen en español Amantadina es un fármaco eficaz para el tratamiento y prevención de influenza A. Su mecanismo de acción es inhibir la proteína M2. Su uso por períodos prolongados puede generar resistencia, la cual ocurre por mutaciones en el gen que codifica para la proteína M2. La mutación más frecuentemente encontrada se ubica en la posición 31. El uso de técnicas de biología molecular permite detectar estas mutaciones. Los objetivos fueron determinar la existencia de resist (mas) encia a amantadina en cepas de virus influenza A aisladas entre los años 2001 y 2002 en un laboratorio de virología en Santiago de Chile, y validar un nuevo método de biología molecular para reconocer cepas resistentes. Para ello se utilizó metodología de RPC y análisis de tamaño de fragmentos de restricción. En 31 cepas procesadas no se observó la presencia de cambios en la posición 31. Estos hallazgos sugieren que la resistencia a amantadina es muy baja o está ausente en nuestro medio. Esto podría explicarse por un limitado uso de este fármaco en esta población. El método descrito puede servir de base para un monitoreo prospectivo de resistencia, que pueda ser de utilidad al médico clínico Resumen en inglés Amantadine has been used for prevention and treatment of influenza A infection. It blocks the proton through the M2 ion channel. Drug-resistant viruses appear quickly when this therapy is used. Single amino acids changes in the H2 protein can confer resistance, being the most frequent one in position 31. Different methods to detect resistant strains have been described. The objectives were to determine the existence of amantadine resistance of influenza A strains isolated (mas) in a virologic laboratory in Santiago, Chile, between 2001-2002, and to validate a new molecular method to detect resistant strains. A PCR restriction fragment length polymorphism analysis was employed for the detection of resistant viruses. In 31 processed strains no mutation in the position 31 was found. This result supports that amantadine resistance is very low or absent in Chile. This could be explained by a limited use of this drug in the study population. This method could be used as a monitoring system to survey resistant viruses

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Susceptibilidad a los agentes antimicrobianos en cepas de Staphylococcus Aureus aisladas en leche de bovinos con mastitis subclínica y leche de tanque/ Antimicrobial Susceptibility of Staphylococcus aureus Strains Isolated from Subclinical Bovine Mastitis Milk and Bulk Tank Milk

Valero-L, Kutchynskaya; Olivares, Yamelys; Perozo, Armindo; Valbuena, Emiro; Boscán, Leonardo; Colina, Gladis; Briñez, Wilfido
2010-07-01

Resumen en español Staphylococcus aureus es uno de los principales patógenos bacterianos de mastitis bovina en el estado Zulia - Venezuela. El objetivo del presente estudio fue determinar la susceptibilidad a los agentes antimicrobianos de cepas de S. aureus aisladas de muestras de leche de cuartos mamarios con mastitis subclínica y leche de tanque en tres fincas del estado Zulia. Un total de 88 cepas fueron analizadas, de estos aislamientos 81 fueron aislados de leche de cuartos mamarios (mas) y 7 de leche de tanque. A las cepas se le determinó la sensibilidad a los agentes antimicrobianos por el método de difusión del disco en agar, correspondientes a: vancomicina (Va), estreptomicina (S), clindamicina (Cc), eritromicina (E), tetraciclina (Te), penicilina (Pe), ciprofloxacina (Cip), cefoxitina (Fox), cloranfenicol (C), enrofloxacina (Enr), rifampicina (Rif), trimetoprim/sulfametoxazol (SXT), oxacilina (Ox) y gentamicina (G). La concentración inhibitoria mínima (CIM) se determinó a Pe, Va, Ox, y E. Las cepas de S. aureus aisladas de leche de cuartos mamarios fueron resistentes a Pe (12,3%), Enr (8,6%), Cip, S (4,9%, respectivamente), E (3,7%), Cc, y Rif (2,5%, respectivamente). Las cepas aisladas de leche de tanque fueron resistentes a Pe y Te (28,6%) y Cc (14, 3%). Los resultados indican que los aislamientos de S. aureus provenientes de leche de cuartos mamarios con mastitis subclínica fueron más susceptibles a todos los agentes antimicrobianos (70%) en comparación con las cepas procedentes de la leche de tanque (57%). Resumen en inglés Staphylococcus aureus is one of the main bacterial pathogens involved in bovine mastitis in Zulia State-Venezuela. The objective of this research was to determine the susceptibility to antimicrobial agents of Staphylococcus aureus isolated from the mammary quarter milk of subclinical mastitis cows and from bulk tank milk in three dairy farms of Zulia State. A total of 88 strains were analyzed, of these isolates 81 were isolated from quarter milk and 7 from bulk tank milk. (mas) The susceptibility to antimicrobial agents of those strains was determined by agar disk diffusion test. The antibiotics tested were: vancomycin (Va), streptomycin (S), clindamycin (Cc), erithromycin (E), tetracycline (Te), penicillin (Pe), ciprofloxacin (Cip), cefoxitin (Fox), chloramfenicol (C), enrofloxacin (Enr), rifampicin (Rif), trimethoprim/sulfametoxazole (SXT), oxacillin (Ox) and gentamicin. (G). Minimum Inhibitory Concentration (MIC) for Pe, Va, Ox and E was determined. S. aureus strains isolated from quarter milk were resistant to Pe (12.3%), Enr (8.6%), Cip, S (4.9%, respectively), E (3.7%), Cc, and Rif (2.5%, respectively). Strains isolated from bulk tank milk were resistant to Pe and Te (28.6%, respectively) and Cc (14.3%). The results indicate that isolates of S. aureus from mammary quarter milk of subclinical mastitis were more susceptible to all antimicrobial agents (70%) compared with strains from the bulk tank milk (57%).

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Comparación del perfil de sensibilidad a antibióticos de cepas de Listeria monocytogenes y Salmonella spp. aisladas a partir de alimentos con cepas de origen clínico

Zamora, Juan Manuel; Chaves, Carolina; Arias, María Laura
2006-06-01

Resumen en español El uso actual de los antibióticos no se da únicamente con fines terapéuticos, sino que se ha extendido hacia la prevención de enfermedades y como promotores del crecimiento en animales. Esta prácticas han llevado a la propagación de resistencia a antibióticos, lo cual representa un riesgo en Salud Pública. En el presente estudio, se evaluó el perfil de sensibilidad a antibióticos de 20 cepas de Listeria monocytogenes y 40 cepas de Salmonella spp. aisladas a part (mas) ir de alimentos y se comparó con los perfiles de sensibilidad de 20 cepas de L. monocytogenes y 100 de Salmonella sp de origen clínico. El 95% de las cepas de L. monocytoges aisladas a partir de alimentos fue sensible a ampicilina, comparado con el 65% de las cepas de origen clínico. De la misma manera, el 100% de las cepas alimentarias mostraron sensibilidad a la gentamicina, comparado en el 85% de las cepas clínicas. El 95% de ambas mostró sensibilidad a tripetropin sulfametoxazol y el 100% a ciprofloxacina. Con respecto a Salmonella spp., para los antibióticos trimetoprim sulfametoxazol, gentamicina, ciprofloxacina, ácido nalidíxico y amoxicilina/ácido clavulánico, los porcentajes de sensibilidad fueron similares, sin embargo, las cepas de origen alimentario mostraron un 97,5% y un 82.5% de sensibilidad a la tetraciclina y cefalexina respectivamente, comparado con un 83 y 90% obtenido a partir de las cepas de origen clínico. Los resultados obtenidos ponen de manifiesto el riesgo potencial que representan las cepas bacterianas aisladas de alimentos en la transmisión de resistencia a los antibióticos. Resumen en inglés Summary The actual use of antibiotics includes, not just its therapeutic cases, but also for disease prevention and as a growth promoter in animals. These practices have resulted in the propagation of resistance to antibiotics, representing a threat for Public Health. In this work, the antibiotic sensibility pattern of 20 Listeria monocytogenes and 40 Salmonella spp. strains, isolated from foodstuff was studied and compared with the antibiotic sensibility patterns of 20 L (mas) . monocytogenes and 100 Salmonella strains of clinical origin. 95% of the L. monocytogenes strains isolated from food were sensible to ampicillin, compared with the 65% of the clinical origin strains. Same way, 100% of food strains were sensible to gentamicin, compared with 85% of clinical origin strains. 95% of both showed sensibility to trimethoprim sulfametoxazole and 100% to ciprofloxacin. For Salmonella spp., the sensibility patterns for trimethoprim sulfametoxazole, gentamicin, ciprofloxacin, nalidixic acid and amoxicilin/clavulanic acid from both origins were similar. Nevertheless, food origin strains showed a 97,5% and 82,5% sensibility for tetracycline and cephalosporin respectively, compared with a 83 and 90% sensibility shown by clinical origin strains. The results obtained demonstrate the potential risk that bacterial strains isolated from food represent in the transmission of antibiotics’ resistance.

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Sensibilidad a los antimicrobianos de cepas de salmonella aisladas en granjas porcinas del estado Zulia/ Antimicrobial susceptibility of salmonella strains isolated from pig herds in Zulia state

Mejia, Willian; Calatayud Marquez, Derwin; Zapata, Denice; Quintero, Armando; Sánchez, Damarys; Mateu, Enric
2008-12-01

Resumen en español El objetivo de este estudio fue determinar los patrones de resistencia a los antimicrobianos de diferentes cepas de Salmonella aisladas en granjas de cerdos del estado Zulia. Para este fin se evaluaron mediante la técnica de Bauer-Kirby, 126 cepas de Salmonella aisladas de heces de cerdos portadores asintomáticos. Las pruebas de sensibilidad antimicrobiana demostraron que los más altos niveles de resistencia fueron frente a la sulfamida (54%), tetraciclina (40%), ácid (mas) o nalidíxico (29%) y ampicilina (23%). Sin embargo, sensibilidad superior al 95% fue encontrada frente a la ceftriaxona, gentamicina, apramicina y colistina. El treinta por ciento de las cepas mostraron multirresistencia (MR) a los antimicrobianos, siendo el patrón de resistencia ASuT (7,14%) el más frecuente. Los resultados obtenidos indican que la proporción de cepas de Salmonella de origen porcino con características de multirresistencia a los agentes antimicrobianos es medianamente elevada (30%) y esta multirresistencia puede afectar a cualquier serotipo. Desde ese punto de vista, la infección de las personas por cepas de Salmonella de origen porcino conlleva a un riesgo potencial de presentar dificultades en el tratamiento específico. Resumen en inglés The aim of this study was to determine antimicrobial resintance paterns of different strains of Salmonella isolated in pig farms of the Zulia State. To achieve these goals 126 strain Salmonella were screened by Kirby-Bauer method, colleted from heces of pigs asymptomatic. Antimicrobial susceptibility tests showed that the highest level of resistance was against Sulphonamides (54%), Tetracycline (40%), Nalidixic acid (29%) and Amplicillin (23%). However, susceptibility sup (mas) erior to 95% was found to Ceftriaxone, Gentamycin, Apramycin and Colistin. Thrity percent of the strains showed multirresitance, being the patterns resistance ASuT (7.14%) the most frequent. The results indicate the proportion of strain of Salmonella of pig origin with characteristics of multiresistance to the antimicrobial agents is elevated (30%) and this multiresistance could affect to anyone serotype. From this point of view, the infection of the people by isolates of Salmonella from swine origin entails a potential risk to present difficulties in the specific treatment.

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Grupos de interesterilidad y productividad de cepas de Pleurotus de regiones tropicales y subtropicales de México/ Intersterility groups and productivity of Pleurotus strains from tropical and subtropical regions of Mexico

Huerta, Graciela; Martínez-Carrera, Daniel; Sánchez, José E.; Leal-Lara, Hermilo
2009-12-01

Resumen en español En una colección de cepas silvestres mexicanas se identificaron los grupos de interesterilidad Pleurotus djamor, P. pulmonarius, P. ostreatus mediante cruzamientos con monospóricos de referencia y dicarión- monocarión. P. levis, P. agaves y P smithii fueron identificados por análisis filogenético de secuencias de la región ITS1-5.8S-ITS2 del ADN ribosómico, debido a falta de cepas de referencia o la similaridad entre alelos de compatibilidad. Las cepas fueron cult (mas) ivadas sobre pulpa de café, para evaluar su productividad y describir la variedad en forma, tamaño, color, textura y sabor de los basidiomas en fresco. Con relación a su productividad, se encontraron seis cepas de P. djamor con fructificación temprana (12 días) y cinco con productividad sobresaliente, con una Eficiencia Biológica (EB) de 116-178%. Para P. pulmonarius una de las cepas mostró fructificación continua (no intermitente) y dos productividad sobresaliente (EB 110-140%). Las cepas de P. smithii y P. agaves no fructificaron a 26°C. Resumen en inglés The intersterility groups Pleurotus djamor, P. pulmonarius, P. ostreatus were identified in a Mexican wild strain collection through crossing the strains with reference monosporics and dikarion - monokarion. Due to lack of reference strains or the similarity between compatibility alleles, P. levis, P. agaves and P. smithii were identified by phylogenetic analysis of ribosomal DNA ITS1-5.8S-ITS2 region sequences. The strains were cultivated on coffee pulp in order to evalu (mas) ate its productivity and describe the variety in form, size, color, texture and flavor of the fresh basidiomes. In relation to productivity it was found six strains of P. djamor with early fructification (12 days) and five with outstanding productivity (116-178% of Biological Efficiency). One strain of P. pulmonarius showed a continued productivity (non intermittent) and other two with excellent productivity (110-140% of BE). The P. smithii and P. agaves strains did not show fructification to 26°C.

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Aislamiento, caracterización y subtipificación de cepas de Escherichia coli O157:H7 a partir de productos cárnicos y leche/ Isolation, characterization and typing of Escherichia coli O157:H7 strains from beef products and milk

Roldán, M. L.; Chinen, I.; Otero, J. L.; Miliwebsky, E. S.; Alfaro, N.; Burns, P.; Rivas, M.
2007-06-01

Resumen en español Escherichia coli productor de toxina Shiga (Stx) (STEC) O157:H7 es un patógeno asociado a enfermedades transmitidas por alimentos, fundamentalmente de origen animal. Se investigó la presencia de E. coli O157 en 250 muestras de carne picada y hamburguesas obtenidas de comercios de las ciudades de Santa Fe y Santo Tomé (Pcia. de Santa Fe) y en 150 muestras de leche provenientes de tanques de enfriado de tambos de la región, utilizando enriquecimiento selectivo y separac (mas) ión inmunomagnética. A partir de 3 muestras de carne (1,2%) se aislaron cepas E. coli O157:H7 stx2, eae, y ehxA positivas, que pudieron ser diferenciadas mediante electroforesis de campo pulsado, fagotipificación y genotipificación de stx. No se aislaron cepas STEC O157:H7 a partir de las muestras de leche. Estos hallazgos confirman la participación de los alimentos de origen animal en la epidemiología de las enfermedades producidas por E. coli O157:H7. Resumen en inglés Shiga toxin (Stx)-producing Escherichia coli (STEC) is an emergent pathogen associated with foodborne diseases, especially foodstuffs of animal origin. A total of 250 beef samples (ground beef and hamburgers) obtained from retail outlets in Santa Fe and Santo Tomé cities, and 150 milk samples from bulk tank milk from dairy barns of the region were analyzed by selective enrichment and immunomagnetic separation. Escherichia coli O157:H7 stx2, eae and ehxA positive strains (mas) were isolated from three (1.2%) beef samples. The strains could be differentiated by pulsed-field gel electrophoresis, phagetyping and genotyping of stx. The milk samples were negative for STEC O157. These findings confirm the role of food of animal origin in the epidemiology of E. coli O157:H7 - associated diseases.

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Transferecia de de ß-lactamasas de espectro extendido desde cepas hospitalarias de Klebsiella pneumoniae a otras especies de enterobacterias/ Transference of extended-spectrum ß-lactamases from nosocomial strains of Klebsiella pneumoniae to other species of Enterobacteriaceae

Sánchez U, Magaly; Bello T, Helia; Domínguez Y, Mariana; Mella M, Sergio; Zemelman Z, Raúl; González R, Gerardo
2006-04-01

Resumen en inglés Background: Klebsiella pneumoniae is an important pathogenic bacterium, frequently isolated from nosocomial samples, that exhibits wide antimicrobial resistance profiles, including third generation cephalosporins (3GC), aminoglycosides and quinolones. The resistance to 3GC is mainly due to the synthesis of extended spectrum beta lactamases (ESBL), encoded by conjugative plasmids. Aim: To investigate the potential transference of resistance to 3GC from nosocomial strains o (mas) f K. pneumoniae to other clinical strains of various species of Enterobacteriaceae. Material and methods: The mating experiments were carried out in liquid media and three nosocomial strains of K. pneumoniae were used as donors. These strains were ESBL-producers and resistant to, at least, one of the 3GC assayed. One strain of Citrobacter freundii, Salmonella typhimurium, Serratia marcescens and Escherichia coli, isolated from clinical specimens, were used as recipients. The presence of bla genes was investigated by PCR. Results: The three nosocomial strains of K. pneumoniae were able to transfer the resistance to 3GC and the genes encoding the ESBL to the susceptible recipient strains of enterobacteria. The frequency of transference was as high as 3.2 x 10-2 transconjugants/recipient cell when the strain of Citrobacter freundii was used as recipient. All transconjugants exhibited high level of resistance to the 3GC assayed. Conclusions: Strains of K. pneumoniae isolated from Chilean hospitals are able to disseminate the ESBL genes to clinical strains of others species of Enterobacteriaaceae

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Localización cromosómica de los genes KMP-11 en cepas KP1(+) y KP1 (-) de Trypanosoma rangeli | Chromosomal localization of the KMP-11 genes in the KP1(+) and KP1(-) strains of Trypanosoma rangeli

Ureña, Claudia; Santander, Paola; Díez, Hugo; Montilla, Marleny; Zarante, Ignacio; Thomas, María del Carmen

Genes encoding for the KMP-11 protein were localized on the chromosomes of Trypanosoma rangeli. These genes were located in two chromosomes of 3,100 and 3,400 kb in the KP1(-) strain whereas in the KP1(+) H14 and Choachí strains, the genes are located in a chromosome of 1,600 kb. The Choachí strain ...

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Localización cromosómica de los genes KMP-11 en cepas KP1(+) y KP1 (-) de Trypanosoma rangeli/ Chromosomal localization of the KMP-11 genes in the KP1(+) and KP1(-) strains of Trypanosoma rangeli

Urueña, Claudia; Santander, Paola; Díez, Hugo; Montilla, Marleny; Zarante, Ignacio; Thomas, María del Carmen; López, Manuel Carlos; Puerta, Concepción
2004-06-01

Resumen en español En este trabajo se determinó la localización cromosómica de los genes codificantes para la proteína 11 de membrana de los kinetoplástidos en Trypanosoma rangeli. Los resultados indican que estos genes se localizan en dos cromosomas de 3.100 y 3.400 kb en la cepa Tre, KP1(-) mientras que en las cepas KP1(+), H14 y Choachí se ubican en 1.600 kb; la cepa Choachí presenta una banda adicional de 1.400 kb. En las cepas Shubacbarina y Munantá de Trypanosoma cruzi, los ge (mas) nes KMP-11 se localizaron en una banda cromosómica de 1.490 kb. Estos resultados sugieren la potencialidad de la localización cromosómica de los genes kmp-11 para diferenciar estos parásitos. Resumen en inglés Genes encoding for the KMP-11 protein were localized on the chromosomes of Trypanosoma rangeli. These genes were located in two chromosomes of 3,100 and 3,400 kb in the KP1(-) strain whereas in the KP1(+) H14 and Choachí strains, the genes are located in a chromosome of 1,600 kb. The Choachí strain presents an additional band of 1,400 kb. In the Shubacbarina and Munanta strains of Trypanosoma cruzi, the KMP-11 genes are located on a chromosomal band of 1,490 kb. Therefore, the chromosomal localization of the KMP-11 genes presents a potential tool to differentiate among these parasites.

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

Leotta, G. A.; Vigo, G. B.; Chinen, I.; Prieto, M.; Callejo, R.; Rivas, M.
2006-09-01

Resumen en español 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 (mas) 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. Resumen en inglés 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 (mas) 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.

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Selección y elaboración de un cultivo iniciador a partir de cepas de Enterococcus aisladas de un queso venezolano ahumado andino/ Selection and Manufacture of an Starter Using Strains of Enterococcus Isolated from a Venezuelan Andean Smoked Cheese

Rodríguez, María Elisa; Chacón Rueda, Zarack; Guerrero Cárdenas, Balmore; Rojas, Julio Otoniel; López Corcuera, Guillermo
2007-12-01

Resumen en español El objetivo del presente estudio fue aislar bacterias del género Enterococcus presentes en una muestra de queso ahumado andino. Se aislaron 15 cepas pertenecientes al género Enterococcus. Se realizaron pruebas confirmatorias para el género, descartando 8 cepas que no reunían las características del género, conservándose 7 que cumplían con las características exigidas. De las cepas seleccionadas se escogieron cuatro cepas entre las que se encontraban las mejores a (mas) cidificadoras de la leche, y además que fueran compatibles con cepas de Lactococcus y Lactobacillus aisladas en un estudio anterior también a partir de un queso ahumado andino. Con las cepas de Enterococcus así como con las de Lactococcus y Lactobacillus, se prepararon diferentes mezclas para su posterior uso como cultivos iniciadores en la elaboración de un queso ahumado elaborado con leche pasteurizada, para obtener un producto con características similares al queso artesanal, pero con los beneficios higiénicos de la leche pasteurizada y una flora bacteriana conocida. Resumen en inglés The objective of the present study was to isolate bacteria from the genus Enterococcus that were present in a sample of smoked Andean cheese. Fifteen strains belonging to the genus Enterococcus were isolated. Confirmatory tests were carried out for this genus, ruling out eight strains that didn’t fulfill the characteristics of the genus, and leaving seven that complied with the required characteristics. Of the strains selected, four were chosen as being amongst the best (mas) milk acidifiers, which also were compatible with strains of Lactococcus and Lactobacillus, isolated in a previous study, and again obtained from smoked Andean cheese. With the strains of Enterococcus, as well as with those of Lactococcus and Lactobacillus, different mixtures were prepared for use as starter in the manufacture of a smoked cheese produced with pasteurized milk, in order to obtain similar characteristics to the handmade cheese, but with the hygienic benefits of pasteurized milk and known bacterial flora.

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Isla de patogenicidad de Vibrio parahaemolyticus en cepas chilenas clínicas y ambientales/ Pathogenicity island region of clinical and environmental strains of Vibrio parahaemolyticus, isolated in Chile

Núñez, Harold; Ulloa, María Teresa; Guerra, Fabiola; Osorio, Carlos G
2009-02-01

Resumen en inglés Background: Most clinical isolates of Vibrio parahaemolyticus produce a major virulence factor known as the thermostable direct hemolysin (TDH). TDH is encoded by the tdh gene which is located in a genomic pathogenicity island (PAI). Most environmental isolates are described as tdh negative. Aim: To assess if environmental strains lack the full pathogenicity island or if only the tdh gene is deleted. Material and methods: Thirty eight clinical and 66 environmental strains (mas) of Vibrio parahaemolyticus were studied. PAI was characterized by polymerase chain reaction (PCR). The presence of tdhA and tdhS genes, was determined by Southern blot. Results: Fifty three environmental strains (80%) lacked a full PAI when compared with clinical strains. In environmental strains, Southern blot and sequence analysis showed that a genetic región of 80 kilobase pairs including genes from VPA1310 to VPA1396 was missing. Conclusions: These results highlight the genetic dynamism of Vibrio parahaemolyticus pathogenecity island región and suggest that new pathogenic strains could appear by horizontal transfer of the island between toxigenic and non-toxigenic strains

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Resistencia a las Fluoroquinolonas y Otros Antimicrobianos en Cepas de Salmonella spp. Aisladas en el Procesamiento de Pollo Entero./ Fluoroquinolone Resistance and Other Drugs in Salmonella spp. Strains Isolated from Whole Chicken Processing.

Briceño-Torres, Lilibeth; Narváez-Bravo, Claudia A; Rodas-González, Argenis; Wittum, Thomas E; Hoet, Armando E
2007-10-01

Resumen en español El objetivo de este estudio fue determinar patrones de resistencia y multirresistencia de cepas de Salmonella spp. aisladas de una planta procesadora de aves, hacia las quinolonas y fluoroquinolonas (ácido nalidíxico=Na, ciprofloxacina=Cf y enrofloxacina=Ex), así como a otros antimicrobianos: tetraciclinas (T), oxitetraciclina (O), neomicina (N), nitrofurantoina (Nf), trimetoprim (Tr) y cloranfenicol (C). Un total de 146 aislamientos de Salmonella spp. fueron obtenidos (mas) de diferentes fuentes: 34 cepas provenientes de mezclas de vísceras blancas (colón, ciegos) y vísceras rojas (hígado y bazo); 87 cepas aisladas de las canales en los procesos de desplume, eviscerado, enfriamiento y empacado; 8 cepas obtenidas de subproductos comestibles (patas, cuellos, hígados y mollejas) y 19 cepas de muestras de ambientes (agua, hielo y superficies de equipos). Se utilizaron técnicas microbiológicas convencionales, pruebas bioquímicas, serológicas y pruebas de susceptibilidad a los antibióticos por difusión en agar. Los resultados revelaron una alta resistencia para Na (73,3%; 107/146), Nf (60,2%; 88/146), T (56,2%; 82/146), O (54,8%; 80/146), Tr (54,1%; 79/146) y una menor resistencia a Ex (6.2%; 9/146), Cf (2,7%; 4/146), N (2,0%; 3/146) y C (2,5%; 4/146). Se encontró un porcentaje elevado de multirresistencia (65,0%; 95/146) y dentro de ellos, los más notorios fueron: NaNfTTr (42,1%), NaNfTr (26,3%) y NaNfT (10,5%). No se observó relación significativa (P>0,05) entre los patrones de resistencia y multirresistencia encontrados con el origen de las diferentes cepas de Salmonella. Estos resultados evidencian el surgimiento de cepas de Salmonellas resistentes a las quinolonas y la necesidad de programas de vigilancia de resistencia antimicrobiana. Resumen en inglés The aim of this study was to determine the resistance and multi-resistance patterns of strains of Salmonella spp. isolated in a poultry processing plant in Zulia State, to quinolones and fluoroquinolones (Nalidixic acid=Na, ciprofloxacin=Cf, and enrofloxacin=Ex), as well as other antimicrobial drugs: tetracycline (T), oxitetracycline (O), neomycin (N), nitrofurantoine (Nf), trimetropim (Tr) and chloranfenicol (C). A total of 146 Salmonella isolates were obtained from diff (mas) erent sources: 34 strains from pools of Intestines (duodenal and colon) and internal organs (liver and spleen); 87 strains of carcass samples collected in four different phases: carcasses after defeathering, evisceration, chilling, and final packed products; 8 strains from edible by-products (neck, liver, gizzard and legs) and 19 strains from environmental samples (water, ice, and equipment surfaces). The detection analyses were performed using conventional microbiological techniques, biochemical tests, serological and agar diffusion methods for antimicrobial susceptibility. The results showed a high resistance to Na (73.3%; 107/146), Nf (60.2%; 88/147), T (56.2%; 82/146), O (54.8%; 80/146), Tr (54.1%; 79/146) and low resistance to Ex (6.2%; 9/146), Cf (2.7%; 4/146), N (2.0%; 3/146) and C (2.7%; 4/146). There was observed a high percentage of multi-resistant strains (65.0%; 95/146) and within of them, the most common patterns were: NaNfTTr (42.1%), NaNfTr (26.3%) and NaNfT (10.5%). No significant relationship was observed (P>0.05) between resistance and multi-resistance patterns with the source of the Salmonella strains. These results are evidence of the emergence of resistant Salmonella strains to fluoroquinolones and the necessity of programs for antimicrobial resistance surveillance.

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DETERMINACIÓN DEL GEN aac(6´)-aph(2´´) ASOCIADO CON RESISTENCIA A AMINOGLUCÓSIDOS EN CEPAS DE STAPHYLOCOCCUS COAGULASA NEGATIVA EN UNA UNIDAD NEONATAL EN BOGOTÁ/ Detection of gene aac(6´)-aph(2´´) in associated with aminoglucosides resistance in Staphylococcus coagulase-negative strains isolates from one neonatal unit in Bogota

Muñoz M, Liliana; Pinilla B, Gladys; Ruiz-Parra, Ariel I; Cifuentes C, Yolanda; Gallego, Eva A
2009-10-01

Resumen en español Antecedentes. La causa más común de resistencia a antibióticos aminoglucósidos en bacterias Gram positivas, especialmente en S. epidermidis, es la enzima modificante AAC(6’)-APH(2"), capaz de acetilar y fosforilar un amplio rango de antibióticos. Objetivo. Determinar la presencia del gen aac(6’)-aph(2") en cepas de Staphylococcus coagulasa negativa aisladas en infecciones neonatales, e investigar la concordancia con las pruebas de sensibilidad in-vitro. Material y (mas) métodos. Se determinó la presencia del gen aac(6’)-aph(2") en 63 cepas de estafilococos coagulasa negativa provenientes de hemocultivos y puntas de catéter, de la Unidad de Neonatología del Instituto Materno Infantil, en Bogotá. Resultados. Staphylococcus epidermidis fue el germen más frecuente y el gen aac(6’)-aph(2") estaba presente en 55 (87,3%) cepas; de éstas, 42 (73,4%) cepas provenían de hemocultivos y 13 (23,6%) cepas de punta de catéter. La susceptibilidad a gentamicina se determinó mediante concentración inhibitoria mínima y para amikacina por difusión en disco. No se encontró asociación estadísticamente significativa entre la presencia del gen aac(6’)-aph(2") y la resistencia a gentamicina y amikacina. Conclusión. La presencia del gen aac(6’)-aph(2") de resistencia a aminoglucósidos es muy alta en cepas de Staphylococcus epidermidis. Diferencias en la expresión del gen pueden explicar parcialmente la falta de consistencia con las pruebas de susceptibilidad utilizadas en la clínica. Resumen en inglés Background. The most common cause of resistance to aminoglucosides is the acetilation and phosphorilation of the antibiotic by the enzyme AAC(6’)APH(2"). Objetive. To determine the presence of the gene aac(6’)-aph(2") in strains of coagulase-negative Staphylococci isolated from infected neonates and to investigate the concordance with the susceptibility tests in-vitro. Materials and methods. the aac(6’)-aph(2") gene was determined in 63 coagulase-negative Staphylococci (mas) strains isolated from blood cultures and catheter tips obtained from the neonatal care unit at the Instituto Materno Infantil in Bogotá, Colombia. Results. Staphylococcus epidermidis was the most frequently identified microorganism. The aac(6’)-aph(2") gene was detected in 55 out of 63 strains (73,43%), 42 strains (87,5%) isolated from blood cultures, and 13 strains (23,6%) isolated from catheter tips. Susceptibility to gentamycin was determined by minimum inhibitory concentration, and susceptibility to amikacin by the disk diffusion antibiotic sensitivity test. There was no a significant statistical association between the presence of the gene and the microbial susceptibility to either gentamycin or amikacin. Conclusion. The presence of the aac(6’)-aph(2") gene in strains of Staphylococcus epidermidis is very high. Differences in the expression of the gene might explain some cases of inconsistency with the susceptibility tests.

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Efecto antifúngico de quitosán de alto peso molecular en cepas de Candida sp aisladas de muestras clínicas/ Antifungal effect of high molecular weight chitosan on Candida spp isolated from clinical samples

Tapia P, Cecilia  ; Soto M, Diego; Vergara G, Leonardo; Alburquerque O, Claudio; Maccioni R, Andrea; Matamata C, Ana M; Hermosilla D, Germán; Bucarey V, Sergio
2009-12-01

Resumen en español El quitosán es un polisacárido de β-glucosamina derivado de la quitina que presenta una actividad antimicrobiana frente a bacterias y hongos. Objetivo: Evaluar el efecto antifúngico de quitosán de alto peso molecular (QAPM) en cepas clínicas de Candida sp. Metodología: Se estudiaron 40 cepas (16 Candida albicans, 11 C glabrata, 5 C tropicalis, 5 C krusei, 2 C parapsilosis y 2 C famatá) mediante un método de microdilución en caldo a pH 7,0 y a ph 4,0. Resulta (mas) dos: De un total de 40 cepas analizadas sólo dos cepas fueron inhibidas por QAPM a pH 7,0 y correspondieron a las cepas control ATCC (C krusei 625 8 y C parapsilosis 22019). Como contrapatida, 37/40 cepas (92,5%) fueron inhibidas a concentraciones inferiores a 1,25 mg/mL de QAPM a pH 4,0. Conclusión: Estos resultados muestran que el QAPM, presenta actividad antifúngica contra cepas clínicas de Candida sp., incluyendo C glabrata y que esta actividad ocurre a pH ácido (4,0). Este compuesto podría utilizase en candidiasis vulvovaginal que cursa a pH 4,0-4,5 Resumen en inglés Chitosan is a D-glucosamine polysaccharide derived from chitin that displays an antimicrobial activity against bacteria and fungi. Objective: to evaluate the antifungal effect of high molecular weight chitosan (HMWC) in clinical strains of Candida spp. Methodology: the susceptibility of forty strains of Candida spp. to HMWC was studied (16 C albicans, 11 C glabrata, 5 C. tropicalis, 5 C krusei, 2 C parapsilosis and 2 C.famatd) by broth microdilution at pH 7.0 and pH 4.0. (mas) Results: of 40 strains, only 2 were inhibited at pH 7.0 and corresponded to ATCC control strains (C. krusei 6258 and C parapsilosis 22019). On the other hand, 37/40 strains (92.5%) were inhibited by concentrations lower than 1.25 mg/mL of HMWC at pH 4.0. Conclusion: these results show that HMWC, presents activity against clinical Candida spp. strains, including C glabrata, and that this activity is present at acid pH (4.0). This compound could potentially be used in vulvovaginal candidiasis since it occurs at pH 4.0-4.5

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Caracterización de factores de virulencia y susceptibilidad antimicrobiana en cepas de Plesiomonas shigelloides aisladas de pacientes con diarrea aguda en Cuba/ Virulence factors and in vitro susceptibility of Plesiomonas shigelloides isolated from diarrhea episodes in Cuba

Bravo F, Laura; Correa M, Yusleidy; Clausell I, Jorge F; Fernández A, Anabel; Ramírez A, Margarita; Núñez F, Fidel; Ledo G, Yudith; Cruz I, Yanaika
2009-06-01

Resumen en español La diarrea aguda (DA) continúa siendo una de las principales causas de consulta en los países en vías de desarrollo. Un agente de baja prevalencia en DA es Plesiomonas shigelloides. En el Laboratorio Nacional de Referencia de Enfermedad Diarreica Aguda del IPK se estudiaron 54 cepas conservadas de P. shigelloides. Se determinó el serotipo detectándose por primera vez en el país la circulación de cuatro serotipos (O20:H2, 056:H18, 07LH31, 08LH22) así como la vanant (mas) e antigénica de mayor prevalencia (094:H3). Se estudió el comportamiento de las cepas frente a 21 agentes antimicrobianos obteniéndose los mayores porcentajes de resistencia frente a ampicilina (77,7%), tetraciclina (29,2%o) y eritromicina (18,5%) mientras que para el resto se obtuvieron porcentajes de resistencia inferior a 33%o. No se evidenció asociación entre los serotipos y los patrones de multi-resistencia presentes en las cepas del estudio. Se estudiaron los factores de virulencia: actividad hemolítica, producción de exo-polisacáridos y adherencia a hidrocarburos. El 22,2% de las cepas resultaron B hemolíticas, 72,2%o presentó bio-película y 92,31% fueron hidrofóbicas. El 17,3% de las cepas presentaron los tres factores de virulencia. Estableciendo una relación entre los factores de virulencia y los serotipos de las cepas con reacción cruzada con el género Shigella se evidenció que 93,3%o de las cepas presentaron al menos uno de los factores de virulencia. El 90,9%o de las cepas multi-resistentes presentó al menos uno de ellos Resumen en inglés Acute diarrhea is still one of the main causes of disease in developing countries. At the National Reference Laboratory for Acute Diarrhoeal Diseases, of the "Pedro Kourí" Tropical Medicine Institute, 54 Plesiomonas shigelloides strains were serotyped. As a result, the circulation of four new serotypes (O20:H2, 056:H18, 071 :H31,081 :H22) was detected. The most common antigenic variant was 094:H3. In addition, the susceptibility pattern to 21 antimicrobial agents (AA) wa (mas) s studied. Highest percentages of resistance were observed to ampicillin (77.7%), tetracycline (29.2%), and erythromycin (18.5%) while, to all other AA the resistance percentages were under 33%. There was no evidence of association between the serotypes and the multi-resistance patterns present in the strains under study. The frequency of virulence factors was determined: 21.15% of the strains turned out to be ß-haemolytic; 73.7% showed the presence of biofilm and 92.31% were hydrophobic. In 17.3% of the strains, the three virulence factors analysed were present. When establishing the relationship among the different virulence factors and the serotypes of the strains through cross reaction with the Shigella genus, there was evidence that 93.3% of the strains showed at least one of the virulence factors studied. Likewise, at least one of the virulence factors analysed was present in 90.9% of the multi-resistant strains

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Caracterización de ß-lactamasas de espectro extendido (BLEE) en cepas nosocomiales de K. pneumoniae. Sucre-Venezuela/ Characterization of extended-spectrum ß-lactamases in nosocomial strains of Klebsiella pneumoniae

Guzmán, Militza; Alonso, Guillermina
2009-12-01

Resumen en español En este estudio, 25 cepas de K. pneumoniae aisladas de pacientes con infección nosocomial durante el periodo agosto 2002 a diciembre de 2003 fueron examinadas para determinar su susceptibilidad antimicrobiana, perfil plasmídico, transferencia de determinantes de resistencia y los tipos de genes blaTEM , blaSHV , blaCTX-M. Diecinueve cepas presentaron susceptibilidad disminuida a las cefalosporinas de tercera generación y al aztreonam y fueron productoras de ß-lactamas (mas) as de espectro extendido (BLEE). Todas las cepas presentaron plásmidos transferibles con una frecuencia de conjugación de 10-3 a 10-4 transconjugantes/célula donante. El análisis de los patrones de restricción reveló la presencia de tres tipos de plásmidos. Las cepas E. coli transconjugantes, además de ser productoras de BLEE, expresaron resistencia a aminoglucósidos y cloranfenicol. Se encontró la presencia del gen blaTEM en todos los plásmidos transferibles y los genes blaSHV y blaCTX en plásmidos transferibles y no transferibles. Las enzimas identificadas fueron TEM-1, SHV-5-2a y CTX-M-2. Los plásmidos presentes en las cepas de K. pneumoniae, juegan un papel importante en la diseminación de los genes que codifican resistencia a los ß-lactámicos y otros antimicrobianos. Resumen en inglés In this study, 25 strains of K. pneumoniae, isolated from patients with nosocomial infections from August 2002 to December 2003, were examined to determine their antimicrobial susceptibility, plasmid profile, transfer capacity of resistance determinants and blaTEM, blaSHV, and blaCTX-M genes. Nineteen nosocomial strains revealed a weakened susceptibility to third-generation cephalosporins and aztreonam, and were extended-spectrum ß-lactamases (ESBLs) producers. All strai (mas) ns presented conjugable plasmids with a conjugation frequency of 10-3 to 10-4 transconjugants/donor cell. The analysis of restriction patterns revealed the presence of three differents plasmids. The Escherichia coli transconjugants were ESBLs producers and expressed resistance for aminoglucosides and chloramphenicol. The blaTEM gen was found in all transferables plasmids and the blaSHV and blaCTX genes were found in transferables and no transferables plasmids. The enzymes identified in the isolates were TEM-1 SHV-5-2a and CTX-M-2. The plasmids present in the K. pneumoniae strains play an important role in the dissemination of the genes encoding resistance to ß-lactams and other antimicrobial agents.

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Caracterización de la región variable de integrones clase 1 presentes en cepas nosocomiales de Klebsiella pneumoniae/ Characterization of the variable region within class 1 integrons in Klebsiella pneumoniae nosocomials strains

GUZMÁN, MILITZA; ALONSO, GUILLERMINA
2010-03-01

Resumen en inglés Background: Integrons are responsible for the capture and dissemination of resistance genes in Gram-negative bacteria. Aim: To characterize the variable region within class 1 integrons in nosocomial strains of Klebsiella pneumoniae. Material and Methods: Twenty-nine Klebsiella pneumoniae strains isolated from hospitalized patients were analyzed. The variable region of class 1 integrons was characterized by polymerase chain reaction and direct sequencing. Genetic localizat (mas) ion of class 1 integrons was determined by bacterial conjugation. Results: Ten strains contained class 1 integrons, with sizes ranging from 750 to 2000 base pairs. One integrant element was present in nine strains and two elements in one single strain. Integrons were associated to plasmids. Cassettes aadA, aac(6)-Iq, orfD, dfrA]7, aadA5 and aadB were found. Conclusions: The presence of class 1 integrons may play an important role in the dissemination of hospital resistance against amino glycosides

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Detección de la actividad de desoxiribonucleasa (DNasa) en cepas de Clostridium chauvoei/ Desoxiribonuclease activity detection in Clostridium chauvoei strains

Carloni, G.H.; Bentancor, L.D.; De Torres, R.A.
2005-06-01

Resumen en español La toxina beta de Clostridium chauvoei posee actividad de desoxiribonucleasa (DNasa) y se considera uno de sus principales factores de virulencia. Se detectó su producción a partir de cepas provenientes de aislamientos bovinos, empleando como controles C. chauvoei American Type Culture Collection (ATCC) 10092 y C. septicum y C. perfringens tipo A, ambos aislamientos de laboratorio. La actividad enzimática se evidenció sobre un sustrato sólido con el agregado de DNA y (mas) verificando macroscópicamente su degradación. Se desarrolló una metodología sencilla empleando agar comercial para ensayo de DNasa, con agregado de suero equino estéril. Cada cepa se sembró sobre la superficie del medio de cultivo, incubando en atmósfera anaerobia hasta 48 horas a 37 °C. Los cultivos se sometieron a la acción de ácido clorhídrico (HCl) 1N. La aparición de una zona clara y transparente alrededor y por debajo del desarrollo microbiano se consideró reacción positiva. La actividad enzimática se detectó en 10 de 12 cepas estudiadas y en los controles. El agregado de suero al medio base comercial permitió el desarrollo óptimo de los microorganismos evidenciando con claridad la zona de digestión enzimática. Resumen en inglés Beta toxin of C. chauvoei has desoxiribonuclease (DNase) activity which is regarded as one of its virulence factors. The production of DNase was detected in strains isolated from bovines, using as controls C. chauvoei ATCC 10092, and C. perfringens Type A and C. septicum, both laboratory isolates. The enzyme activity was made evident on a DNA substrate observing the macroscopic degradation. A simple methodology was developed using a commercial medium for DNase test, with (mas) the incorporation of sterile horse serum. Each strain was streaked on the surface of the medium, incubated in anaerobic atmosphere at 37 °C for 48 hours. The plates were revealed with HCl 1N. The appearance of a clear and transparent zone around and under the microbial growing was considered a positive reaction. Enzyme activity was detected in 10 of 12 strains and also in the controls. The serum addition to the commercial basal medium allows the optimum development of the microorganism showing the enzymatic digestion zone.

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ACTIVIDAD ANTAGÓNICA FRENTE A Pyricularia grisea (Sacc.) Y FITOESTIMULACIÓN EN EL CULTIVO DEL ARROZ DE CEPAS AUTÓCTONAS DE Pseudomonas putida (Trev.)/ ANTAGONISTIC ACTIVITY AGAINST Pyricularia grisea (Sacc.) AND GROWTH STIMULATION IN RICE OF Pseudomonas putida (Trev.) NATIVE STRAINS

Rives, Narovis; Acebo, Yanelis; Almaguer, M; García, J.C; Hernández, Annia
2009-08-01

Resumen en español La aplicación de inoculantes de origen bacteriano en cultivos de importancia económica, constituye una alternativa ecológica que permite la obtención de mayores rendimientos y la conservación del medio ambiente. La obtención y caracterización de cepas autóctonas, potencialmente eficientes en la promoción del crecimiento vegetal y el control biológico de patógenos constituye un paso esencial para el desarrollo de inoculantes microbianos. Esta investigación se d (mas) esarrolló con el objetivo de caracterizar cepas de Pseudomonas putida previamente aisladas del cultivo del arroz variedad J-104 en cuanto a su actividad promotora del crecimiento vegetal y su efecto antagónico frente a Pyricularia grisea. Se realizaron experimentos in vitro para detectar la producción de compuestos indólicos, producción de sideróforos, actividad antagónica contra P. grisea y el efecto estimulador del crecimiento vegetal de las cepas, en plantas de arroz de 12 días de edad sembradas en tubos de ensayo con medio Murashige y Skoog (MS). Los resultados mostraron la capacidad de producir metabolitos del tipo ácido 3-indolacético (45,8 - 56 µg.mL-1) y sideróforos (7,3-39,4 µM) por las cepas en estudio, las que manifestaron efecto antagónico frente a P. grisea (82-86% de inhibición del crecimiento fúngico) y como promotor del crecimiento vegetal, esto último, a través de su efecto sobre algunos parámetros del crecimiento evaluados (altura de la planta, largo de la raíz, masa fresca aérea y de raíz), destacándose un comportamiento integral en las cepas de P. putida AJ9, AJ14, AJ20 y AJ18. Desde el punto de vista práctico estos resultados indican las potencialidades de las cepas estudiadas para su utilización como inoculantes microbianos en beneficio del cultivo del arroz. Resumen en inglés The application of bacterial inoculants in crops economicaly important crops has been an ecological alternative to improve crop yield and to preserve the environment. The obtaining and characterization of native strains associated with several crops and potentially efficient to promote plant growth and to biocontrol the phytopathogens are key steps to the development of microbial inoculants. This research was carried out to characterize strains of Pseudomonas putida, isol (mas) ated from rice (Oryza sativa L. var. J-104) as phytostimulators and antagonistic agents against Pyricularia grisea. In vitro experiments were carried out to detect the production of indolic compounds and siderophores, antagonistic activity against P. grisea and to assess the phytostimulating effect of the strains in 12-day-old rice plants grown in Murashige and Skoog medium. The results showed the ability of the strains to produce indolacetic acid-like metabolites (45,8 to 56 µg·mL-1) and siderophores (7,3 to 39,4µM) . The strains showed antagonistic effect against P. grisea (82-86% of fungal growth inhibition) and were also capable of promoting plant growth (by increase in plant height, root length, root fresh weight and aerial part fresh weight), standing out the strains AJ9, AJ14, AJ20 and AJ18 for the best performance. From the practical point of view, these results show the potential of these strains to be used as inoculants in rice crop.

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Integrones y cassettes genéticos de resistencia a antimicrobianos en cepas de Shigella flexneri/ Integrons and antimicrobial resistance gene cassettes in Shigella flexneri strains

Muñoz A, Jeannette; Bello T, Helia; Domínguez Y, Mariana; Mella M, Sergio; Zemelman Z, Raúl; González R, Gerardo
2003-07-01

Resumen en inglés Background: The resistance of Shigella flexneri to antimicrobial agents can be associated to the presence of integrons that may contain and express antimicrobial resistance gene cassettes. Aim: To study antimicrobial resistance and the presence of integrons and antimicrobial gene cassettes in Shigella flexneri strains. Material and methods: In vitro susceptibility to 27 antimicrobials was studied in twenty four Shigella flexneri strains isolated from stools. The presence (mas) of integrons class 1, 2 and 3 and antimicrobial resistance gene cassettes was investigated by polymerase chain reaction (PCR) using specific primers for each gene. Results: Most strains were resistant to one of the following antimicrobials: ampicillin, sulphonamide, trimethoprim, tetracycline, streptomycin, sulfamethoxazole-trimethoprim or chloramphenicol. Twenty nine percent were simultaneously resistant to all these antimicrobials. Integrons class 1 and 2 were found in 19 strains (79%). Class 3 integrons were not found. Gene cassettes dfrA1 and ant(3")I were associated to integrons class 2 in most strains (15/20, 75%). Genes cat, tetB and blarTEM were detected in 18/24 (75%), 7/24 (29%) and 4/24 (17%) of the strains, respectively and were not associated to any of the studied integrons. Genes that codify enzymes AAC(6')Ib and APH(3')VI were not detected in any strain. Conclusions: The high frequency of integrons found in the studied strains, could partly explain the increasing antimicrobial resistance of Shigella flexneri strains, isolated in Chile (Rev Méd Chile 2003; 131: 727-33)

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Evaluación del Agar Azul Bromotimol Lactosa introducido en BioCen con cepas de referencia/ Assessment of Agar Blue Bromotimol Lactose introduced in BioCen using reference strans

Villegas Blanco, Maikel Fausto
2009-03-01

Resumen en español OBJETIVO: exponer los resultados obtenidos en las evaluaciones realizadas a los medios de cultivo Agar azul bromotimol lactosa producido en BioCen, Cuba, y el comercializado por la Merck, Alemania, destinado para la diferenciación de microorganismos especialmente las enterobacterias, por su capacidad de fermentar la lactosa. MÉTODOS: se ensayaron un total de 13 cepas certificadas y una aislada de muestra de agua, pertenecientes al Departamento de Investigaciones de Medi (mas) os de Cultivo (BioCen). RESULTADOS: las cepas evaluadas en ambos productos mostraron similitud en cuanto a su respuesta y a las características morfológicas de las colonias. Los valores del índice relativo de crecimiento (IRC) para 10 cepas superaron el 90 %, resultando el 71,5 % del total, mientras que solo 4 cepas reflejaron valores inferiores, resultando el 28,5 % del total. Todas las cepas sobrepasaron el valor recomendado (> 70 %), además las características culturales desarrolladas respondían a las reportadas. CONCLUSIONES: los resultados alcanzados en la determinación del IRC demuestran la buena calidad del medio producido en BioCen frente a cepas de referencia, tomando como criterio el hecho de que todos los microorganismos ensayados mostraron valores del IRC superiores al valor recomendado. Resumen en inglés OBJECTIVE: to show results obtained in evaluations performed in agar blue bromotimol lactose culture media produced in BioCen, Cuba, and that marketed by Merck, Germany, created for microorganism differentiation, specially the Enterobacter ones, due to its ability for lactose fermentation. METHODS: we assayed a total of 13 certified strains and another isolated from water sample, from Research Department of Culture Media (BeioCen). RESULTS: values or Growing Relative Inde (mas) x for 10 strains were above 90 %, with 71,5% of total, while that only 4 strains shoed lower values to a 28,5 % of total. All strains exceeded the recommended value (>70%). CONCLUSIONS: strains evaluated in both products showed similarity as regard its response and to morphologic features of colonies.

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Isolation and screening of Trichoderma strains antagonistic to Sclerotinia sclerotiorum and Sclerotinia minor/ Aislamiento y selección de cepas de Trichoderma antagonistas a Sclerotinia sclerotiorum y Sclerotinia minor

Ibarra-Medina, Verónica Azucena; Ferrera-Cerrato, Ronald; Alarcón, Alejandro; Lara-Hernández, María Encarnación; Valdez-Carrasco, Jorge Manuel
2010-06-01

Resumen en español Sclerotinia sclerotiorum (Ss) y Sclerotinia minor (Sm) afectan severamente más de 400 especies de plantas, y pueden causar reducciones en rendimiento por arriba del 50%. Con el propósito de obtener microorganismos potenciales para el control de ambos patógenos, se realizó el aislamiento de cepas de Trichoderma a partir de muestras de suelo con diferente uso agrícola y forestal. Setenta y un aislados fúngicos de Trichoderma (IBA) fueron obtenidos a través de técnic (mas) a de trampas con esclerocios. Subsecuentemente, se evaluó su capacidad micoparasítica sobre micelio y esclerocios de ambos fitopatógenos mediante cultivos duales in vitro. Los más altos porcentajes de colonización (>90%) de las cepas de Trichoderma sobre Ss y Sm fueron observados para los aislamientos IBA-3, IBA-4, IBA-38, e IBA-54. En general, la habilidad de los aislamientos de Trichoderma para parasitar y degradar esclerocios fue agresiva en los aislamientos IBA-3, IBA-4, IBA-23, IBA-38, IBA-46, IBA-54, e IBA-56. Con base en criterios morfológicos, cuatro de los más prominentes aislamientos fueron identificados como T. viride (IBA-4), T. pseudokoningii (IBA-23), T harzianum (IBA-38), y T. virens (IBA-46). Estas cepas de Trichoderma tienen importante potencial como antagonistas de Ss and Sm. Resumen en inglés Sclerotinia sclerotiorum (Ss) and Sclerotinia minor (Sm) drastically affect more than 400 plant species, and may cause crop yield reductions up to 50%. With the purpose to obtain potential microorganisms to control both pathogens, the isolation of Trichoderma strains from soil samples with different agricultural and forestry use was performed. Seventy-one fungal Trichoderma isolates (IBA) were obtained through sclerotia-trap techniques. Subsequently their mycoparasitic ac (mas) tivities on mycelium as well as on sclerotia of both phytopathogens were assessed by in vitro dual cultures. The highest percentages of colonization (>90%) of the Trichoderma strains on Ss and Sm were found for the isolates IBA-3, IBA-4, IBA-38, IBA-54. The ability of Trichoderma strains to parasitize and to degrade sclerotia in general was aggressive for the strains IBA-3, IBA-4, IBA-23, IBA-38, IBA-46, IBA-54, and IBA-56. Based on morphological criteria, four of the most prominent strains were identified as T. viride (IBA-4), T. pseudokoningii (IBA-23), T. harzianum (IBA-38), and T. virens (IBA-46). These Trichoderma strains have important potential as antagonists to Ss and Sm.

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Localización cromosómica de los genes KMP-11 en cepas KP1(+) y KP1 (-) de Trypanosoma rangeli

Ureña, Claudia; Santander, Paola; Díez, Hugo; Montilla, Marleny; Zarante, Ignacio; Thomas, María del Carmen; López López, Manuel Carlos; Puerta, Concepción Judith
2004-06-01

Digital.CSIC (Spain)

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Genomic divergence of Escherichia coli strains: evidence for horizontal transfer and variation in mutation rates | Divergencia genómica de algunas cepas de Escherichia coli: pruebas de la transferencia horizontal y variación en las velocidades de mutación

Elena, Santiago F.; Whittam, Thomas S.; Winkworth, Cynthia L.; Riley, Margaret A.; Lenski, Richard E.

This report describes the sequencing in the Escherichia coli B genome of 36 randomly chosen regions that are present in most or all of the fully sequenced E. coli genomes. The phylogenetic relationships among E. coli strains were examined, and evidence for the horizontal gene transfer and variation ...

DRIVER (Spanish)

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Red de vigilancia de resistencia antimicrobiana PRONARES: Informe primer semestre 2001/ PRONARES ANTIMICROBIAL SURVEILLANCE NETWORK ON ANTIMICROBIAL AGENTS RESISTANCE: REPORT OF THE FIRST SEMESTER 2001

Trucco A, Olivia; Prado J, Valeria; Durán T, Claudia; grupo PRONARES
2002-01-01

Resumen en español En el transcurso de los años hemos sido testigos de un creciente problema de resistencia antimicrobiana, fenómeno que involucra cada día mayor número de cepas, nuevas especies y nuevos mecanismos. En noviembre de 1997 iniciamos una red de vigilancia de resistencia antimicrobiana PRONARES (Programa Nacional de Resistencia), en diferentes hospitales del país, que trabajando un protocolo común (20 cepas por síndrome clínico por mes) y utilizando un programa computaci (mas) onal WHONET (diseñado para vigilancia), nos permitiera detectar y monitorear el problema de la resistencia bacteriana en Chile. Los resultados del primer semestre de este año reportan 5.251 cepas de diferentes síndromes clínicos. En ITU, Escherichia coli (1.088 cepas) demostró alta susceptibilidad a todos los antimicrobianos, Klebsiella (1.000 cepas) demostró un perfil de resistencia más elevado, en cepas de Enterococcus spp se observó 30% de resistencia a ciprofloxacina y 2% a nitrofurantoína. Entre 899 cepas procedentes de infecciones invasoras, Staphylococcus aureus (555 cepas), mostró elevado perfil de resistencia a cloxacilina 40% superior -40%- (21%) al observado en cepas aisladas de piel y tejidos blandos (550). Shigella spp, (137 cepas) presentó 80% de resistencia a ampicilina y 32% a cloranfenicol; ciprofloxacina y furazolidona demostraron muy buena actividad in vitro frente a este enteropatógeno. Al comparar cepas nosocomiales y de la comunidad, las primeras mostraron un perfil de mayor resistencia. Mantener una red nacional de vigilancia de resistencia se hace cada vez más necesario para orientar el uso adecuado de antibacterianos y evitar así que el fenómeno aumente Resumen en inglés During the last years we have seen are emerging antimicrobial agents resistance that compromise more strains, new species and new mechanisms. In November 1997 we iniciated a network of antimicrobial surveillance named PRONARES in differents hospitals that working with a unique protocol (20 strains by month by syndrome) and using a computational software WHONET surveys the resistance in Chile. The results obtained during the first semester of 2001 shows the susceptibility (mas) pattern of 5.251 strains isolated from different clinical syndromes. In urinary tract infections E. coli (1.088 strains) were very susceptible to all the antibiotics tested, Klebsiella spp (1.000 strains) were more resistant. In Enterococcus we observed 30% of ciprofloxacin resistance and 2% of nitrofurantoin resistance. Among 899 invasive strains, S. aureus (655 strains) presented a high methicillin resistance level (40%) more than 20% observed in skin and soft tissue infections. Shigella spp (137) presented 80% of ampicillin resistance and 32% to chloramphenicol. Ciprofloxacin and furazolidone had better activity. Comparing nosocomial and community strains, the higher pattern of resistance was observed in nosocomial strains. It is very important to maintain the surveillance network to prescribe the appropriate antimicrobial and to avoid the increase of resistance

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Isolation and characterization of culturable bacteria from tropical coastal waters/ Aislamiento y caracterización de bacterias cultivables de aguas costeras tropicales

Lee, C-W; Ng, A Y-F; Narayanan, K; Sim, E U-H; Ng, C-C
2009-06-01

Resumen en español En este estudio se aislaron y caracterizaron algunas bacterias cultivables de las aguas costeras tropicales de Malasia Peninsular. Se obtuvieron entre 0.23 y 1.85 x 10³ ufc mL-1 en medio de cultivo Zobell 2216E, y se cultivaron 0.04% a 0.12% de los conteos totales de bacterias. Se seleccionaron diferentes cepas bacterianas mediante RFLP del gen 16S rDNA usando cuatro enzimas de restricción (Ddel, Hhal, Rsal y Sau3AI), de las cuales Hhal produjo más patrones de RFLP. Se (mas) obtuvieron un total de 54 cepas singulares, las cuales fueron identificadas por su secuencia 16S rDNA. Estas cepas bacterianas fueron divididas en cinco clases: 38 cepas de γ-proteobacterias (61.1%), 3 cepas de α-proteobacterias (5.5%), 2 cepas del grupo Cytophaga-Flavobacter-Bacteroides (3.7%), 3 cepas de bacterias Gram positivas con alto contenido de GC (5.5%) y 13 cepas de bacterias Gram positivas con bajo contenido de GC (24.1%). Estos aislados tienen un buen potencial para futuros estudios biotecnológicos ya que 56% de ellos presentaron actividad de la enzima amilasa, mientras que 36% y 18% presentaron actividad de las enzimas proteasa y lipasa, respectivamente. La mayoría (>70%) de los aislados produjeron poli-B-hidroxibutirato. Resumen en inglés In this study we isolated and characterized some culturable bacteria from tropical coastal waters of Peninsular Malaysia. We obtained between 0.23 and 1.85 x 10³ cfu mL-1 in the Zobell 2216E medium, and cultured 0.04% to 0.12% of total bacterial counts. Different bacterial strains were then selected by 16S rDNA RFLP using four restriction enzymes (Ddel, Hhal, Rsal, and Sau3AI), of which Hhal gave the most RFLP patterns. A total of 54 unique strains were obtained and thes (mas) e were identified by their 16S rDNA gene sequence. These bacterial strains could be divided into five classes: 38 strains of γ-Proteobacteria (61.1%); 3 strains of α-Proteobacteria (5.5%); 2 strains of the Cytophaga-Flavobacterium-Bacteroides group (3.7%); 3 strains of high GC, Gram-positive bacteria (5.5%); and 13 strains of low GC, Gram-positive bacteria (24.1%). These isolates have good potential for further biotechnological studies since about 56% of the isolates exhibited amylase activity, whereas 36% and 18% of the isolates had protease and lipase, respectively. Most (>70%) of the isolates also produced poly-B-hydroxybutyrate.

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Detección y caracterización de Escherichia coli productor de toxina Shiga a partir de casos clínicos y de alimentos en Uruguay/ Detection and characterization of Shiga toxin - producing Escherichia coli from clinical cases and food in Uruguay

Varela, G.; Chinen, I.; Gadea, P.; Miliwebsky, E.; Mota, M.I.; González, S.; González, G.; Gugliada, M.J.; Carbonari, C.C.; Algorta, G.; Bernadá, M.; Sabelli, R.; Pardo, L.; Rivas, M.; Schelotto, F.
2008-06-01

Resumen en español Establecimos la frecuencia de aislamiento de Escherichia coli productor de toxina Shiga (STEC) a partir de muestras clínicas y de alimentos, así como las características fenotípicas y genotípicas de las cepas recuperadas. Se analizaron 198 muestras fecales de niños con diarrea sanguinolenta (DS), 14 muestras fecales de niños con síndrome urémico hemolítico (SUH) y 220 muestras de carne picada. También se estudiaron 4 cepas STEC aisladas de alimentos embutidos. (mas) Se recuperó STEC de 3 (1,5%) de los niños con DS, de 1 (7%) niño con SUH y de 4 (1,8%) de las muestras de carne picada. Todas las cepas fueron eae y ehxA positivas. Los serotipos detectados fueron: O157:H7 (9 cepas), O26:H11 (2 cepas), O111:NM (1 cepa) y O145:HNT (1 cepa). Todas las cepas O157:H7 portaron el subtipo eae-g1; las cepas O26:H11 y O145:HNT portaron el subtipo eae-b1 y la cepa O111:NM portó el subtipo eae-g2/q. Las cepas STEC del mismo serogrupo mostraron alta diversidad genética. En Uruguay STEC no sería agente frecuente de diarrea con sangre en niños. Sin embargo, las cepas recuperadas presentaron los genes asociados con enfermedad severa y 2 de los 3 niños infectados con STEC evolucionaron a SUH. La carne picada y otros alimentos serían vehículos importantes de O157:H7. Resumen en inglés We have assessed the frequency of Shiga toxin-producing Escherichia coli (STEC) in clinical and food samples as well as studied the genotypic and phenotypic characteristics of the recovered strains. One hundred ninety eight fecal samples from children with bloody diarrhea (BD), 14 from children with hemolytic uremic syndrome (HUS), 220 ground beef samples and 4 STEC isolates from other beef-derived products were analyzed. The STEC strains were isolated from 3 (1.5%) child (mas) ren with bloody diarrhea, 1 (7%) from a child with HUS and 4 (1.8%) from ground beef samples. All strains were eae and ehxA positive. The serotypes found were: O157:H7 (9 strains), O26:H11 (2), O111: NM (1) and O145:HNT (1). All O157:H7 STEC strains harbored the eae subtype g1, O26:H11 and O145:HNT strains, subtype b1 and O111:NM strain, subtype g2/q. The STEC strains of the same serogroup showed high genetic diversity. In Uruguay, STEC is not frequently isolated from cases of bloody diarrhea in children. However, all the recovered STEC strains carried the genes associated with severe disease and 2 out of 3 children infected with STEC developed HUS. Ground beef and other food products might be important vehicles for O157:H7 strains.

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Utilidad del Sistema API 20NE para identificar especies del género Acinetobacter y otros bacilos gramnegativos no fermentadores/ Use of the API 20NE System to identify species of the Acinetobacter genus and other non fermenting gram-negative bacilli

Salazar de Vegas, Elsa Z; Nieves, Beatriz; Ruíz, Joaquín; Vila, Jordi
2008-12-01

Resumen en español Se utilizaron 62 cepas identificadas inicialmente como bacilos gramnegativos no fermentadores (BGNNF), aisladas de pacientes con diagnóstico de infección nosocomial, con el objeto de determinar su género y especie. Cuarenta y cinco cepas fueron identificadas como Acinetobacter baumannii, 10 como Pseudomonas aeruginosa, 3 como Stenotrophomonas maltophilia, 3 como Comamonas acidovorans y 1 como Achromobacter xylosoxidans subsp. xylosoxidans, mediante el API 20NE. Con res (mas) pecto a las cepas de Acinetobacter, el ARDRA permitió identificar 20 cepas como A. baumannii y 23 como Acinetobacter genoespecie 13TU, pero 2 cepas no fueron identificadas por este método. La secuencia de la subunidad 16S del ADNr de todas las cepas incluidas en este estudio permitió identificar 20 cepas como A. baumannii, 23 cepas como Acinetobacter RUH1139, 10 como P. aeruginosa, 4 como A. xylosoxidans subsp. xylosoxidans (2 de estas cuatro cepas habían sido identificadas como A. baumannii mediante API20NE), 3 como S. maltophilia, 1 como C. acidovorans y 1 como β-Proteubacterium. Las discrepancias entre la identificación bioquímica por API 20NE y por ARDRA, para diferenciar las genoespecies de Acinetobacter, fue resuelta por la secuenciación de la subunidad 16S del ADNr, indicando que la identificación de los aislados de Acinetobacter, entre otros BGNNF, mediante API 20NE, debe ser confirmada por técnicas genéticas. Resumen en inglés We used 62 strains initially identified as non fermenting gram-negative bacilli (NFGNB) isolated from patients with a nosocomial infection diagnosis with the purpose of identifying their genus and species. Forty five strains were identified as Acinetobacter baumannii, 10 as Pseudomonas aeruginosa, 3 as Stenotrophomonas maltophilia, 3 as Comamonas acidovorans and 1 as Achromobacter xylosoxidans subspecies xylosoxidans through the API 20NE. Regarding the Acinetobacter strai (mas) ns, the ARDRA allowed to identify 20 strains as A. baumannii and 23 as Acinetobacter genospecies 13TU, but 2 strains were not identified with this method. The ADNr 16S sequence of all the strains included in this study allowed to identify 20 strains as A. baumannii, 23 strains as Acinetobacter RUH1139, 10 as P. aeruginosa, 4 as A. xylosoxidans subsp. xylosoxidans (2 of these four strains strains had been identified as A. baumannii through API20NE), 3 as S. maltophilia, and 1 as C. acidovorans and 1 as β-Proteubacterium. The discrepancies between the biochemical identification by API 20NE and by ARDRA to differentiate the Acinetobacter genospecies was resolved by the ADNr16S sequencing, indicating that the identification of the Acinetobacter isolates, among other NFGNB, through API 20NE, should be confirmed through genetic techniques.

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Inoculación de trigo (Triticum aestivum, L.) con rizobios adaptados a ecosistemas ganaderos de Alberta, Canadá/ Inoculation of wheat (Triticum aestivum, L.) with rhizobia adapted to livestock ecosystems of Alberta, Canadá

Bécquer, C.J; Salas, Beatriz; Archambault, D; Slaski, J; Anyia, A
2007-03-01

Resumen en español Se efectuó un ensayo en invernadero con el objetivo de seleccionar cepas de rizobio inoculadas en trigo (Triticum aestivum, L., var. CDC Teal). Para ello se utilizaron 16 cepas nativas canadienses pertenecientes a Sinorhizobium medicae, así como 12 cepas comerciales. Los inóculos se confeccionaron en medio CLM y fueron agitados hasta alcanzar un título de 10(6)-10(8) cél./mL. Se utilizaron los métodos estándar para la inoculación de cereales. Se construyó un dend (mas) rograma mediante el método de Ward (distancia euclidiana al cuadrado). Se evaluaron las variables: peso seco aéreo (PSA), peso seco raíz (PSR), longitud del tallo (LT), peso seco espigas (PSE) y número de hijos (NH). Se constató un incremento significativo en todas las variables en los tratamientos inoculados con las cepas nativas y las cepas comerciales de rizobio, comparados con el testigo absoluto. En peso seco aéreo, peso seco espigas y peso seco raíz, la mayor parte de los tratamientos no difirieron significativamente del control fertilizado. En longitud del tallo existieron 17 tratamientos superiores estadísticamente con respecto al control fertilizado. Se seleccionaron 10 cepas del total. Los tratamientos seleccionados en el dendrograma constituyeron el 31% para las cepas nativas y el 42% para las comerciales. Se recomienda efectuar ensayos de campo con las cepas seleccionadas inoculadas en cereales de interés económico para Cuba. Resumen en inglés A greenhouse experiment was carried out in order to select rhizobium strains inoculated on wheat (Triticum aestivum, L., var. CDC Teal). For that 16 Canadian native strains, belonging to Sinorhizobium medicae, as well as 12 commercial strains, were used. The inocula were prepared in YMB medium and shaken up to obtain a title of 106-108 cells/mL. The standard methods for the inoculation of cereals were used. A dendrogram was constructed by means of the Ward's method (squar (mas) e Euclidian distance). The variables: aerial dry weight (ADW), dry weight of root (DWR), stem length (SL), dry weight of spikes (DWS) and number of shoots (NS) were evaluated. A significant increase was observed in all the variables in the treatments inoculated with the native strains and the commercial strains of rhizobium, as compared to the absolute control. In aerial dry weight, dry weight of spikes and dry weight of root, most of the treatments did not differ significantly from the fertilized control. In stem length there were 17 treatments statistically higher than the fertilized control. Ten strains were selected from the total. The treatments selected in the dendrogram constituted 31% for the native strains and 42% for the commercial strains. Field trials with the strains selected inoculated on cereals of economic interest for Cuba are recommended.

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Determinación del poder bactericida de la crema de vancomicina al 0,5 % frente a Staphylococcus aureus/ Determination of bactericidal power of 0.5 % vancomycin cream related to Staphylococcus aureus strains used in burn patients

Nodarse Hernández, Rafael; Braña Suárez, Juan Carlos; Palacios Alfonso, Irene
2009-12-01

Resumen en español OBJETIVOS. Determinar el poder bactericida per se de la crema de vancomicina al 0,5 % (vehiculizada en crema de nitrofurazona al 0,2 %) para avalar su utilización en el tratamiento tópico de infecciones producidas por Staphylococcus aureus en pacientes quemados. MÉTODOS. Se utilizó crema de vancomicina al 0,5 %, la cual se obtuvo agregando 2 bulbos de vancomicina clorhidrato 500 mg a un frasco de crema de 200 mg de nitrofurazona al 0,2 %; para determinar su poder bact (mas) ericida in vitro se realizó la prueba de susceptibilidad a antimicrobianos mediante el método de difusión con discos. Los discos utilizados fueron preparados al efecto, embebidos en cremas de vancomicina (contenían además nitrofurazona) y nitrofurazona, hasta alcanzar la concentración deseada. Se utilizaron 7 cepas correspondientes a Staphylococcus aureus aislados en pacientes («cepas salvajes»), para ser enfrentadas a los discos en estudio. RESULTADOS. Las cepas 1, 2 y 3 correspondieron a estafilococos sensibles a meticilina, mientras que las cepas 4, 5, 6 y 7 eran resistentes a este antibiótico. CONCLUSIÓN. La crema de vancomicina al 0,5 % fue capaz de inhibir el crecimiento in vitro de cepas salvajes de Staphylococcus aureus causantes de infecciones, tanto de cepas sensibles a meticilina como de cepas resistentes a este antibiótico. Este efecto lo consiguió por sí misma y no por sinergismo con nitrofurazona, la cual se mostró inefectiva frente a cepas de Staphylococcus aureus resistente a meticilina. Resumen en inglés OBJECTIVE. To determine the bactericidal power per se of the 0.5 % Vancomicyn cream (0.2 % Nitrofurazone cream as vehicle) to guarantee its use in topical treatment of infections caused by Staphylococcus aureus in burned patients. METHODS. We used 0,5 % Vancomicyn cream obtained adding two bulbs of hydrochlorate (500 mg) to a cream small bottle of 0.2 % Nitrofurazone (200 mg).To determine its bactericidal power in vitro a susceptibility test to antimicrobials by disk-diff (mas) usion method. Disk used were prepared to that effect embedded in Vancomicyn cream plus Nitrofurazone to achieve the desired concentration. We used 7 strains corresponding to Staphylococcus aureus isolated from patients (wild strains) to be exposed to study disks. RESULTS. One, two and three strains corresponded to Methicillin-sensitive staphylococcus, where as the four, five, six and seven strains were resistant to this antibiotic. CONSLUSIONS. The 0.5 % Vancomicyn cream was able to inhibits the in vitro growth of wild strains of S. aureus causing the infections, of Methicillin-sensitive strains and those resistant to this antibiotic. This effect was achieved per se and not by Nitrofurazone synergism, which was ineffective in face of Methicillin-resistant S. aureus.

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Evaluación de dos técnicas de subtipificación molecular para el estudio de Pasteurella multocida/ Evaluation of two techniques of molecular subtyping to study Pasteurella multocida

Leotta, G. A.; Chinen, I.; Vigo, G. B.; Gugliada, J.; Rivas, M.
2006-12-01

Resumen en español Se determinó la tipibilidad, la reproducibilidad y el poder discriminatorio de ERIC-PCR y ApaI-PFGE para establecer la relación genética de cepas de Pasteurella multocida. Se estudiaron 49 cepas de diferente origen, subespecie, biotipo, grupo capsular, serotipo somático y perfil de resistencia antimicrobiana. Por ERIC-PCR se establecieron 31 patrones, los que presentaron entre 10 y 14 bandas en un rango comprendido entre 0,2 y 1,2 kb. Por ApaI-PFGE se detectaron 37 pa (mas) trones de restricción, los cuales presentaron entre 7 y 15 bandas bien definidas de 34 a 450 kb. La tipibilidad de ERIC-PCR fue del 100% (T=1) y la de ApaI-PFGE del 94% (T=0,94). La reproducibilidad de ambas técnicas fue del 100% (R=1); sin embargo, el poder discriminatorio de ERIC-PCR fue 93% (D=0,93) y el de ApaI-PFGE 98% (D=0,98). Mediante ambas técnicas fue posible agrupar las cepas con relación epidemiológica y diferenciar claramente las cepas no relacionadas. Se demostró el valor de ERIC-PCR y ApaI-PFGE para complementar estudios epidemiológicos, principalmente si las cepas en estudio son analizadas por ambas técnicas. Resumen en inglés Typeability, reproducibility, and discriminatory power of ERIC-PCR and ApaI-PFGE to establish the genetic relation of P. multocida strains were determined. Forty-nine strains of different source, biotype, capsular group, somatic serotype, and resistance to antimicrobials were studied. By ERIC-PCR, 31 patterns were defined with 10 to 14 bands in a rank of 0.2 and 1.2 kb. By ApaI-PFGE, 37 restriction patterns were established with 7 to 15 bands of 34 to 450 kb. Typeability (mas) was 100% (T=1) for ERIC-PCR, and 94% (T=0.94) for ApaI-PFGE. Reproducibility of both techniques was 100% (R=1). Discriminatory power was 93% (D=0.93) for ERIC-PCR, and 98% (D=0.98) for ApaI-PFGE. By using both techniques, epidemiologically related strains were grouped, and unrelated strains were clearly differentiated. The value of ERIC-PCR and ApaI-PFGE as complements to epidemiologic studies was demonstrated, especially when both techniques were used to analyze the strains.

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EVALUACIÓN in vitro DE HONGOS NEMATÓFAGOS PARA EL CONTROL BIOLÓGICO DE NEMÁTODOS GASTROINTESTINALES DE RUMIANTES/ IN VITRO ASSESSMENT OF NEMATOPHAGUS FUNGI FOR BIOLOGICAL CONTROL OF GASTROINTESTINAL NEMATODES OF RUMINANTS

Orozco A, Martha; Álvarez C, Víctor; Jiménez R, Ana; Acuña N, Óscar
2009-09-01

Resumen en español Objetivo. Determinar la actividad depredadora in vitro de cepas de hongos nematófagos autóctonos de Costa Rica. Materiales y métodos. Dieciséis cepas de hongos nematófagos nativos de Costa Rica de los géneros Candelabrella musiformis, Arthrobotrys oligospora y Dactylella sp. Se evaluó in vitro la actividad depredadora de los hongos frente a nemátodos gastrointestinales como Haemonchus spp., Oesophagostomum sp. y Trichostrongylus sp aislados de pequeños rumiantes. (mas) Resultados. La actividad de los hongos fue muy heterogénea, presentándose resultados que van desde 9.8 a 99.6% de depredación. Conclusiones. El análisis estadístico demostró diferencias significativas en la actividad de los hongos; sin embargo, las cepas de A. oligospora mostraron un mejor desempeño en la captura de nemátodos comparado con las cepas de C. musiformis y Dactylella sp. La heterogeneidad encontrada responde a factores como: origen de las cepas, características intrínsecas de las mismas y especies de larvas utilizadas. Resumen en inglés Objetive. To determine in vitro predatory activity of fungi strains nematófagos native of Costa Rica. Materials and methods. Sixteen native strains of nematophagus fungi from Costa Rica isolated from different substrata and identified as Candelabrella musiformis, Arthrobotrys oligospora and Dactylella sp. In order to assess their fungi predatory activity, it was evaluated in vitro assay gastrointestinal nemátodos as Haemonchus spp., Oesophagostomum sp. and Trichostrongy (mas) lus sp, isolated from small ruminants. Results. The activity of fungi was very heterogeneous, ranging between 9.8 and 99.6%. Conclusions. The statistical analysis showed significant differences; however, A. oligospora strains were more effective in capturing nematodes in comparison with C. musiformis and Dactylella sp. strains. Heterogeneity is explained by factors like strains origin, their own characteristics and type of larvae used in the test.

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Selección de rizobios adaptados a ecosistemas ganaderos de Alberta, Canadá, inoculados en maíz (Zea mays, L.).: Fase I: invernadero/ Selection of rhizobia adapted to livestock production ecosystems from Alberta, Canada, inoculated in corn (Zea mays, L.).: Stage I: greenhouse

Bécquer, C.J; Salas, Beatriz; Archambault, D; Slaski, J; Anyia, A
2008-12-01

Resumen en español Se efectuó un ensayo en invernadero con el objetivo de seleccionar cepas de rizobio inoculadas en maíz (Zea mays, L.), para lo cual se utilizaron 16 cepas nativas canadienses de Sinorhizobium meliloti, así como 12 cepas comerciales, pertenecientes a diferentes géneros y especies de rizobio. Los inóculos se confeccionaron en medio CLM y fueron agitados hasta alcanzar un título de 10(6)-10(8) cél./mL. Se evaluaron las variables: peso seco aéreo (PSA), peso seco raí (mas) z (PSR) y longitud del tallo (LT). Se constató que en todas las variables existieron tratamientos inoculados que fueron estadísticamente superiores al control absoluto. En el PSA dos tratamientos no difirieron significativamente del control fertilizado; mientras que sólo cuatro tratamientos inoculados en LT y cinco en PSR fueron estadísticamente inferiores al control fertilizado. La agrupación en conglomerados permitió seleccionar las cepas CAC8, CAC9, CAC17 y CAC17a, para su posterior evaluación en condiciones de campo. El 100% de los tratamientos seleccionados en el dendrograma fueron inoculados con cepas nativas. Al evaluar los tratamientos en cuanto al nivel de dependencia del PSA y la LT con respecto al PSR, se observó una regresión fuerte del PSA en los inoculados con cepas nativas, y débil en los inoculados con cepas comerciales, así como en los controles. La regresión fue débil en la LT en todos los tratamientos. Se recomienda la continuación de estas investigaciones en condiciones de campo, además de otros estudios más profundos. Resumen en inglés A greenhouse experiment was conducted in order to select rhizobium strains inoculated on corn (Zea mays, L.), for which 16 Canadian native strains of Sinorhizobium meliloti, as well as 12 commercial strains, belonging to different rhizobium genera and species, were used. The inoculi were prepared in BYM medium and shaken to obtain a titer of 10(6)-10(8) cells/mL.. The variables evaluated were: aerial dry weight (ADW), root dry weight (RDW) and stem length (SL). In all the (mas) variables some inoculated treatments were observed to be statistically higher than the absolute control. In ADW two treatments did not differ significantly from the fertilized control; while only four inoculated treatments in SL and five in RDW were statistically lower than the fertilized control. Cluster analysis allowed to select the strains CAC8, CAC9, CAC17 and CAC17a, for their later evaluation under field conditions. One hundred percent of the treatments selected in the dendrogram were inoculated with native strains. When evaluating the treatments regarding the level of dependence of ADW and SL with regards to RDW, a strong regression of ADW was observed in the ones inoculated with native strains, and a weak regression in the treatments inoculated with commercial strains. The regression was weak in SL for all treatments. To continue this research under field conditions, in addition to further studies, is recommended.

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Distribución y susceptibilidad a fluconazol de levaduras del género Candida aisladas en pacientes hospitalizados y ambulatorios/ Species distribution and fluconazole susceptibility of yeasts of genus Candida isolated from hospitalized and ambulatory patients

Alburquerque O, Claudio; Hermosilla D, Germán; Tapia P, Cecilia
2009-10-01

Resumen en español La mayoría de los estudios de vigilancia de levaduras del género Candida se realizan en candidiasis invasora en pacientes hospitalizados; sin embargo, no existen estudios que evalúen simultáneamente la distribución global de especies y susceptibilidad a fluconazol de cepas de Candida aisladas de pacientes hospitalizados y ambulatorios. Se analizaron 166 cepas de Candida, recolectadas consecutivamente en un período de 6 meses, las cuales fueron aisladas de flujo vagi (mas) nal (73,5%), orina (7,8%), muestras respiratorias bajas (7,8%), hemocultivos (4,2%), líquidos estériles (2,4%) y heridas (1,8%). Un 71,1% provenía de pacientes ambulatorios. La especies aisladas fueron Candida albicans (78,9%), C glabrata (8,4%), C tropicalis (6,0%), Cfamata (1,8%), C. krusei (1,8%), C parapsilosis (1,8%) y C. sake (1,2%). Los porcentajes de sensibilidad a fluconazol fueron: 92,3%o para C. albicans, 85,7%o para C glabrata (siendo la mayoría sensible dosis dependiente), 100%) para C parapsilosis y 80%o para C tropicalis. En los niños, todos hospitalizados, se aislaron sólo cepas sensibles, mientras que en adultos ambulatorios se aislaron más cepas resistentes, fundamentalmente de flujo vaginal. Considerar cepas ambulatorias en futuros estudios de vigilancia permitirían dar cuenta de probables reservónos de cepas más resistentes, como C. glabrata Resumen en inglés Most surveillance studies have included invasive candidiasis from hospitalized patients. However, no national study has evaluated the species distribution and susceptibility to fluconazole of Candida species isolated from hospitalized and ambulatory patients. Atotal of 166 strains were collected consecutively during a 6 month period. Strains were isolated from vaginal fluid (73.5%), uriñe (7.8%), lower respiratory tract samples (7.8%), blood cultures (4.2%), sterile flui (mas) ds (2.4%) and wounds (1.8%). Most of the isolates were obtained from ambulatory patients (71.1%). The species found were Candida albicans (78.9%), C glabrata (8.4%), C. tropicalis (6.0%o), C.famata (1.8%), C krusei (1.8%), C parapsilosis (1.8%) and C. sake (1.2%). Fluconazole susceptibility was: 92.3%o for C. albicans, 85.7 % for C glabrata (most strains being dose-dependent susceptible), 100%) for C parapsilosis and 80%) for C tropicalis. Only susceptible strains were isolated from hospitalized children, whereas more resistant strains were isolated from ambulatory adults, mainly from vaginal fluid. In order to identify probable reservoirs of less susceptible strains such as C. glabrata, it would be necessary to include ambulatory isolates in future surveillance studies

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IDENTIFICACIÓN DEL GEN syl EN AISLAMIENTOS CUBANOS Streptococcus suis PROCEDENTES DE CERDOS MEDIANTE LA REACCIÓN EN CADENA DE LA POLIMERASA (PCR)/ IDENTIFICATION OF syl GENE IN CUBAN ISOLATES OF Streptococcus suis FROM SWINE USING THE POLYMERASE CHAIN REACTION (PCR)

Espinosa, Ivette; Domínguez, Patricia; Lobo, Evelyn; Alfonso, P; Martínez, Siomara
2010-04-01

Resumen en español Streptococcus suis es un coco anaerobio facultativo, considerado un importante agente asociado a meningitis, artritis, endocarditis y neumonía en cerdos. En este trabajo se realizó el aislamiento de S.suis a partir de diferentes condiciones clínicas como neumonía, abscesos en articulaciones y tonsilas de animales asintomáticos. Se identificaron 14 cepas de S. suis: 11 a partir de pulmones, 2 de abscesos y 1 de tonsila. Las cepas mostraron diferentes patrones de prueb (mas) as bioquímicas. El gen que codifica para la hemolisina denominados suilisina (syl) se detectó por PCR solamente en 5 cepas de las cuales 4 proceden de pulmón y una de tonsila. Sin embargo, en los aislamientos procedentes de abscesos y asociados a artritis no se detectó la presencia de este gen, lo cual muestra un comportamiento similar a las cepas presentes en Norte América syl -, asociadas a enfermedad invasiva. Resumen en inglés Streptococcus suis is a facultative anaerobic coccus considered an important agent associated to meningitis, arthritis, endocarditis and pneumonia. In this work, the isolation of S. suis from different clinical conditions such as pneumonia, joint and tonsil in asymptomatic animals was carried out. Fourteen strains of S. suis were identified: 11 from lungs, 2 from abscess and 1 from tonsils. The strains showed different pattern of biochemistry test. The syl gene codifying (mas) for suylisin was detected by PCR only in 5 strains, four coming from lung and one from tonsil. However, in the isolations from abscess and associated to arthritis, the presence of this gene was not detected showing a similar behaviour to the strains from North America (syl -) associated to invasive disease.

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Aislamiento, Identificación y Caracterización de Bacterias Ácido Lácticas de un Queso Venezolano Ahumado Andino Artesanal. Su Uso Como Cultivo Iniciador./ Isolation, Identification and Characterization of Lactic Acid Bacterias from Venezuelan Artisanal Andino Smoked Cheese. Their Use as Starter.

Alvarado Rivas, Carmen; Chacón Rueda, Zarack; Otoniel Rojas, Julio; Guerrero Cárdenas, Balmore; López Corcuera, Guillermo
2007-05-01

Resumen en español Veinte cepas de microorganismos, aisladas a partir de una muestra de queso venezolano ahumado andino artesanal, se sometieron a pruebas bioquímicas clásicas y morfológicas para determinar su género. En este trabajo sólo se tomó en cuenta los géneros Lactococcus, Lactobacillus y Leuconostoc que son los más utilizados en la Industria Quesera como cultivos iniciadores. De las veinte, ocho pertenecían al género Lactococcus y dos al género Lactobacillus, con ellas s (mas) e realizaron pruebas como: capacidad acidificadora de la leche, resistencia a antibióticos, resistencia a productos de limpieza de uso industrial y compatibilidad entre cepas. De acuerdo a sus características de aptitud tecnológica se seleccionaron cuatro cepas: dos lactococos y dos lactobacilos. Las cepas selecionadas se emplearon como cultivos iniciadores en la fabricación de quesos ahumados experimentales utilizando leche pasteurizada. Estos quesos se sometieron a una evaluación sensorial en la que también se incluyeron dos controles: un queso elaborado con leche cruda (sin cultivo iniciador) y el artesanal que dió origen a las cepas. Los resultados obtenidos en la degustación se analizaron con un análisis de varianza, que demostró que los quesos elaborados con las cepas seleccionadas, son equivalentes al artesanal y al fabricado con leche cruda. Resumen en inglés Twenty strains of microorganisms isolated from a sample of venezuelan artisanal andino smoked cheese were subjected to several biochemical and morphological tests in order to determine their genera. In this work it was only considered the genus Lactococcus, Lactobacillus and Leuconostoc that are those more used in the cheesemaker industry. From the twenty strains, eight belonged to the genus Lactococcus and two to the genus Lactobacillus, all ten strains were tested for s (mas) election as starter cultures and were carried out tests like: acidification activity, antibiotic resistance, detergent resistance and strains compatibility. Four strains (two lactobacilli and two lactococci) were selected according to their technological aptitude characteristics. The selected strains were used as the starters in order to produce experimental smoked cheeses using pasteurized milk. The experimental cheeses were subject to sensory analysis, for comparison two cheeses were included in the sensory analysis: an experimental cheese produced from raw milk (without starters) and the artisanal cheese. The sensory analysis results were subjected to a variance analysis, which showed no significant differences between the experimental cheeses and the control cheeses.

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Staphylococcus aureus meticilino resistente en niños escolares de Cartagena/ Methicillin-resistant Staphylococcus aureus in children attending school in Cartagena, Colombia

Castro-Orozco, Raimundo; Villafañe-Ferrer, Lucy M; Álvarez-Rivera, Eduviges; Martínez De Arco, Melina; Rambaut-Donado, Carmen L; Vitola-Heins, Gina V
2010-06-01

Resumen en español Objetivo Determinar portadores nasales de Staphylococcus aureus resistente a meticilina (SARM) y factores de riesgo asociados a esta colonización, en una población escolar de Cartagena de Indias. Métodos Se realizó un estudio analítico transversal en 100 niños escolares sanos, para la búsqueda de portadores nasales de cepas SARM y su asociación con factores de riesgo. Para la identificación bacteriana se utilizaron métodos convencionales. A todos los aislamiento (mas) s se les determinó la sensibilidad a antibióticos por el método de Kirby-Bauer. Resultados De la población escolar, se identificaron 36 cepas de S. aureus; 25 %, oxacilino-resistentes; 66,7 %, oxacilino-sensibles y 8,3 %, con sensibilidad intermedia. El 67 % de cepas SARM aisladas fueron sensibles a todos los antibióticos probados. Una cepa (SARM-Ant4) presentó resistencia a tres antibióticos con mecanismos de acción diferentes. Conclusiones Este es el primer estudio realizado en Cartagena, que determinó las frecuencias de portadores nasales de S. aureus y cepas SARM en una población escolar, registrándose un 33 % y 9 %, respectivamente. Todas las cepas de S. aureus oxacilino-resistente, fueron también cefoxitino-resistente, lo que hace sospechar la presencia del gen mecA. El uso de antibióticos betalactámicos en los últimos tres meses, incrementa aproximadamente cinco veces más el riesgo de ser portador nasal de cepas SARM (aOR=4,72 [IC95 %=0,96-23,98] p Resumen en inglés Objective Determining nasal carriers of methicillin-resistant Staphylococcus aureus (MRSA) and associated risk factors for nasal colonisation in a school-aged population in the seaside city of Cartagena, Colombia. Methods A cross-sectional, analytical study was carried out on 100 healthy schoolchildren to determine MRSA nasal carriage and its association with risk factors. Bacteria were identified using conventional methods. Antibiotic sensitivity was determined by the Ki (mas) rby Bauer method. Results A total of 36 isolates of S. aureus were identified in the school children. 25 % of the strains were oxacillin-resistant, 66.7 % oxacillin-sensitive and 8.3 % had intermediate susceptibility. 67 % of the MRSA strains isolated were sensitive to all antibiotics tested. One strain (MRSA-Ant4) showed resistance to antibiotics having different mechanisms of action. Conclusions This is the first study in Cartagena which determined the frequency of S. aureus and MRSA strains nasal carriers in a school population (33 % and 9 %, respectively). All S. aureus oxacillin-resistant strains were cephoxitin-resistant, thereby leading to the presence of the mecA gene being suspected. Having used beta-lactam antibiotics during the last three months increased the likelihood of being an MRSA nasal carrier by around five times (OR=4.72; 0.96-23.98 95 %CL; p

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Especies de Fusarium de la Quebrada de Lozano, Jujuy, Argentina/ Fusarium species of the Quebrada de Lozano, Jujuy, Argentina

Flores, C.; San Martín, S.; Carrillo, L.; Bejarano, N.
2005-06-01

Resumen en español Se hizo un muestreo de suelo en 50 sitios cultivados con especies hortícolas y florales donde hubo antecedentes de fusariosis. Para el aislamiento se empleó agar rosa Bengala, agar peptona dicloran cloranfenicol y agar cayote dicloran cloranfenicol, siendo este último el más conveniente. Las cepas aisladas fueron identificadas como F. acuminatum, F. avenaceum, F. graminearum, F. merismoides, F. oxysporum, F. poae, F. proliferatum, F. semitectum, F. solani, F. subgluti (mas) nans y F. sporotrichioides. En los ensayos sobre plantines se comprobó la patogenicidad de las cepas de F. acuminatum y F. proliferatum aisladas de sitios cultivados con Cucurbita ficifolia y Vicia faba respectivamente, y de las cepas de F. oxysporum obtenidas de suelos con cultivos de Chrysanthemum leucanthemum, Ocimum basilicum y Zea mays. Las cepas provenientes de sitios con estas tres especies vegetales que se recuperaron de los plantines como invasores secundarios fueron F. merismoides, F. semitectum y F. subglutinans. Resumen en inglés A soil sampling was made in 50 cultivated places with horticultural and floral species where there were fusariosis records. For the isolation Bengal rose agar, peptone dichloran chloramphenicol agar and cayote dichloran chloramphenicol agar were used, being this last one, the more convenient. The isolates were identified as F. acuminatum, F. avenaceum, F. graminearum, F. merismoides, F. oxysporum, F. poae, F. proliferatum, F. semitectum, F. solani, F. subglutinans and F. (mas) sporotrichioides. It was proven the pathogenesis of F. acuminatum and F. proliferatum strains isolated from cultivated places with Cucurbita ficifolia and Vicia faba respectively, and of the strains of F. oxysporum obtained of soils with cultivations of Chrysanthemum leucanthemum, Ocimum basilicum and Zea mays. The F. merismoides, F. semitectum and F. subglutinans strains coming from places with these three vegetable species, were recovered as secondary invaders.

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ACTIVIDAD ANTAGÓNICA ENTRE BACTERIAS EPIBIÓTICAS AISLADAS DE ESPONJAS MARINAS DEL CARIBE COLOMBIANO Y SU RELACIÓN CON LA MACROEPIBIOSIS/ ANTAGONISTIC ACTIVITY BETWEEN EPIBIOTIC BACTERIA ISOLATED FROM MARINE SPONGES OF THE COLOMBIAN CARIBBEAN AND ITS RELATIONSHIP WITH THE MACROFOULING

Mora-Cristancho, Jennyfer; Zea, Sven; Gil-Agudelo, Diego L.
2009-01-01

Resumen en español Las superficies sumergidas en el mar son densamente colonizadas por bacterias y sus interacciones, tales como la inhibición del crecimiento, son importantes para determinar el desarrollo de comunidades bacterianas, como también de posteriores etapas de la macroepibiosis. Para determinar el potencial de interacción entre bacterias de las biopelículas de esponjas, se realizaron ensayos de actividad de inhibición in vitro de crecimiento entre cepas bacterianas aisladas (mas) de superficies con diferente grado de macroepibiosis, de las esponjas Aplysina insularis (limpia), Aplysina lacunosa (con macroepibiosis) y de la superficie calcárea de la concha del molusco bivalvo Donax sp. El porcentaje total de interacción antagónica entre estas cepas bacterianas fue del 64 %; las cepas bacterianas aisladas de superficies limpias inhibieron el crecimiento de cepas provenientes de superficies muy colonizadas en proporciones cercanas a 1:1. Cepas de superficies no colonizadas tuvieron mayor frecuencia de interacciones antagónicas. Se propone la interacción bacteriana antagónica como posible mecanismo de regulación del crecimiento poblacional y de esta forma del desarrollo de etapas subsecuentes de la macroepibiosis. Resumen en inglés Surfaces submerged in the sea are densely colonized by bacteria, and inter-specific interactions such as growth inhibition are important determinants of the development of bacterial communities, as well as of later phases of macrofouling. To determine the potential interactions among biofilm bacteria from sponges we carried out in vitro growth inhibition tests between bacterial strains isolated from surfaces with various degrees of macrofouling, from the sponges Aplysina (mas) insularis (clean), Aplysina lacunosa (fouled), and from the calcareous surface of the bivalve mollusk Donax sp. The total percentage of antagonistic interactions among these strains was 64 %; strains isolated from clean surfaces inhibited the growth of strains from well-colonized surfaces in a 1:1 ratio. Strains from clean surfaces had a higher frequency of antagonistic interactions. We propose bacterial antagonistic interaction as a possible mechanism of population growth regulation and, consequently, of the development of subsequent phases of macrofouling.

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La región intergénica del gen H2A apoya las subpoblaciones KP1(-) y KP1(+) de Trypanosoma rangeli/ The intergenic region of the histone h2a gene supports two major lineages of Trypanosoma rangeli

Suárez, Brian Alejandro; Cuervo, Claudia Liliana; Puerta, Concepción Judith
2007-09-01

Resumen en español Introducción. Con base en la amplificación del ADN de los minicírculos del cinetoplasto y de los genes miniexón, Trypanosoma rangeli ha sido clasificado en las subpoblaciones KP1(-) y KP1(+). Objetivo. Comparar la región intergénica de los genes H2A entre cepas KP1(+) y KP1(-) de T. rangeli, con el fin de aportar evidencias a dicha división. Materiales y métodos. Se amplificó, clonó y determinó la secuencia de la región intergénica de los genes h2a de las cep (mas) as KP1(-) Tre y 5048 y de la cepa Choachí KP1(+). Dichas secuencias, junto con las reportadas para las cepas C23 KP1(-) y H14 KP1(+), fueron utilizadas para la reconstrucción de árboles filogenéticos basados en los métodos de neighbor-joining, máxima parsimonia y máxima verosimilitud, utilizando la cepa Y de Trypanosoma cruzi como grupo raíz externo. Resultados. Se evidenció heterogeneidad intraespecífica en el tamaño de la región estudiada, soportados por valores bootstrap de 85% (neighbor-joining), 66% (máxima parsimonia) y 57% (máxima verosimilitud), los resultados indican que las cepas KP1(-) se agrupan aparte, claramente diferenciadas de las cepas KP1(+), las cuales presentan una mayor heterogeneidad intraespecífica en tamaño y secuencia. Además, se encontró mayor proximidad filogenética entre T. rangeli y T. cruzi que entre T. rangeli y Trypanosoma brucei. Conclusiones. Los análisis filogenéticos basados en la región intergénica de los genes h2a de las cepas estudiadas apoyan la división de T. rangeli en las subpoblaciones KP1(-) y KP1(+). Sin embargo, se requiere estudiar un mayor número de cepas para confirmar estos hallazgos. Resumen en inglés Introduction. Trypanosoma rangeli has been classified in the KP1(+) and KP1(-) subpopulations, based on the mini-exon gene and kinetoplast DNA minicircle amplification profiles. Objective. The intergenic region of the histone h2a gene was compared between KP1(+) and KP1(-) strains of T. rangeli to substantiate this classification. Materials and methods. The amplification, cloning and sequencing of the h2a gene intergenic region was undertaken for the Tre and 5048 KP1(-) s (mas) trains for comparison with the Choachí KP1(+) strain. These sequences, along with those previously reported for the KP1 (+) and KP1 (-) H14 and C23 strains, were used to reconstruct phylogenetic trees based on the "neighbor-joining", maximum parsimony and maximum likelihood methods. The Y strain of Trypanosoma cruzi was chosen as the outgroup. Results. Intra-specific heterogeneity was observed in the size of the gene region under study, supported by bootstarp values of 85% (neighbor-joining), 66% (maximum parsimony) and 57% (maximum likelihood). The KP1(-) strains were grouped apart, clearly differentiated from the KP1(+) strains. The latter demonstrated a higher intra-specific heterogeneity, both in sequence length and composition. In addition, a closer phylogenetic relationship between T. rangeli and T. cruzi was found to be more closely related to one another than to T. rangeli and Trypanosoma brucei. Conclusion. Phylogenetic analyses of analyzed strains based on the intergenic region of the h2a genes supported the T. rangeli grouping in two major subpopulations known as KP1(+) and KP1(-) strains. However, a higher number of strains are needed to confirm this finding.

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Interacción tripanosoma-vector-vertebrado y su relación con la sistemática y la epidemiología de la tripanosomiasis americana/ Trypanosoma rangeli parasite-vector-vertebrate interactions and their relationship to the systematics and epidemiology of American trypanosomiasis

Vallejo, Gustavo Adolfo; Guhl, Felipe; Carranza, Julio César; Triana, Omar; Pérez, Gerardo; Ortiz, Paola Andrea; Marín, Dairo Humberto; Villa, Lina Marcela; Suárez, Jazmín; Sánchez, Isaura Pilar; Pulido, Ximena; Rodríguez, Ingrid Bibiana; Lozano, Leyder Elena; Urrea, Daniel Alfonso; Rivera, Fredy Arvey; Cuba-Cuba, César; Clavijo, Jairo Alfonso
2007-01-01

Resumen en español Introducción. Trypanosoma rangeli es la segunda especie de tripanosoma que infecta al hombre en América Latina. Se ha observado variabilidad en las características biológicas, bioquímicas y moleculares en diferentes aislamientos de este parásito. Objetivo. Estudiar las características morfológicas y moleculares de cepas de T. rangeli aisladas de diferentes especies de Rhodnius e inoculadas en diferentes especies de vertebrados. Materiales y métodos. Se utilizaron (mas) 19 cepas de T. rangeli aisladas de R. prolixus, R. pallescens y R. colombiensis en Colombia, R. ecuadoriensis en Perú y R. pallescens en Panamá. Se evaluó el polimorfismo de los tripomastigotes sanguíneos en ratones ICR y se estudió el pleomorfismo de la cepa P53 de T. rangeli KP1(-) inoculada en ratón, marsupial y canino. Se efectuó análisis de ADN polimorfo amplificado aleatorio en 12 cepas aisladas de cuatro especies de Rhodnius. Resultados. Se observaron tres grupos discretos en la longitud total de los tripomastigotes sanguíneos y la cepa P53 presentó diferencias significativas en el tamaño de los tripomastigotes sanguíneos en ratón, marsupial y canino. El análisis de ADN polimorfo amplificado aleatorio mostró segregación de las cepas en dos ramas correspondientes a las cepas de T. rangeli KP1(+) y T. rangeli KP1(-). De otra parte todos las cepas de T. rangeli KP1(-) se agruparon de acuerdo con las especies de Rhodnius de las cuales fueron aisladas. Conclusión. Este es el primer estudio que revela una estrecha asociación entre cepas de T. rangeli y las especies de Rhodnius, confirmando que cada especie de Rhodnius transmite al hospedero vertebrado poblaciones del parásito con claras diferencias fenotípicas y genotípicas, lo cual soporta la evolución clonal de estas poblaciones. Introduction. Trypanosoma rangeli is a species of trypanosome second to T. cruzi, that is infective to humans in Latin America. Variability in the biological, biochemical and molecular characteristics between different isolates isolates of this parasite have been recorded. Objective. Morphological and molecular characteristics were recorded from strains of T. rangeli that were isolated from different species of Rhodnius and maintained in different vertebrate species. Materials and methods. Nineteen strains of T. rangeli were isolated from R. prolixus, R. pallescens and R. colombiensis in Colombia, R. ecuadoriensis in Peru and R. pallescens in Panama. Polymorphism of blood trypomastigotes in ICR mice was evaluated and pleomorphism of P53 strain of T. rangeli KP1(-) inoculated in mouse, marsupial and canine was studied. RAPD analysis (randomly amplified polymorphic DNA analysis) of 12 strains isolated from four species of Rhodnius was performed. Result. Based on the total length of blood trypomastigotes, three discrete groups were observed. The P53 strain showed significant differences in the size of blood trypomastigotes in mouse, marsupial and canine. RAPD analysis showed that the strains segregated into two branches corresponding to strains of T. rangeli KP1(+) and T. rangeli KP1(-). All strains of T. rangeli KP1 (-) clustered according to the species of Rhodnius from which they were isolated . Conclusion. These data reveal, for the first time, a close association amongst T. rangeli strains and Rhodnius species, confirming that each species of Rhodnius transmits to vertebrate hosts a parasite population with clear phenotypic and genotypic differences. This is further evidence that supports the concept of clonal evolution of these parasites.

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Tipificación molecular y fenotípica de Staphylococcus aureus resistentes a meticilina (SAMR) en un hospital universitario/ Molecular and phenotypical typification of methicillin resistant Staphylococcus aureus (MRSA) strains in a university hospital

Castellano-González, Maribel J; Perozo-Mena, Armindo J; Vivas-Vega, Rosana L; Ginestre-Pérez, Messaria M; Rincón-Villalobos, Gresleida C
2009-02-01

Resumen en español Objetivo: Tipificar por métodos moleculares y fenotípicos, las cepas SAMR aisladas de pacientes y personal de enfermería para establecer su posible origen clonal. Materiales y Métodos: Se analizaron 50 cepas SAMR aisladas en un Hospital Universitario de Maracaibo (Venezuela). La tipificación se efectuó mediante electroforesis en gel de campo pulsado (EGCP) y antibiotipia. Resultados: Entre pacientes, se obtuvieron 19 antibiotipos y 12 grupos (I-XII); mientras que, e (mas) n el personal de salud, por EGCP se detectaron seis grupos (I-VI) y dos antibiotipos. No se encontró asociación estadísticamente significativa entre los antibiotipos y patrones de bandas obtenidos por EGCP (p > 0,05). Conclusiones: Por medio de la detección de marcadores de resistencia y mediante la EGCP, es factible diferenciar la naturaleza de las cepas SAMR de origen clínico. Los resultados obtenidos demuestran la posible transmisión intrahospitalaria de cepas SAMR; así como, su diseminación clonal en los servicios del hospital, particularmente en la UCI, durante el período estudiado Resumen en inglés Objective: To typify by molecular and phenotypical methods, MRSA strains, isolated from patients and nurses to establish their possible clonal origin. Materials and Methods: 50 MRSA strains isolated in a teaching hospital in Maracaibo (Venezuela) were analyzed. The typification of MRSA strains was performed by means of pulsed-field gel electrophoresis (PFGE) and antibiotyping. Results: In patients, 12 clusters (I-XII) and 19 antibiotypes were found; whereas in the health- (mas) care personnel, 6 clusters (I-VI) and two antbiotypes were detected. There was no statistically significative association between antibiotypes and band patterns obtained by PFGE (p>0.05). Conclusions: By means of detection of resistance markers and PFGE, it is feasible to discrimínate the nature of the clinical strains of MRSA. The obtained results show the possible nosocomial transmission of MRSA strains and their clonal spread in hospital departments, particularly at the ICU

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Detección de la enterotoxina A de Staphylococcus aureus mediante la reacción en cadena de la polimerasa (PCR) y su correlación con las pruebas de coagulasa y termonucleasa/ Staphylococcus aureus enterotoxin A detection using the polymerase chain reaction (PCR) and its correlation with coagulase and thermonuclease tests

Suarez, María José; Arias, María Laura; Gamboa, María del Mar
2008-03-01

Resumen en español Staphylococcus aureus es una bacteria patógena, de amplia distribución en la naturaleza, asociada con infección general y brotes alimentarios. La relación de esta bacteria con cuadros alimentarios se ha realizado, históricamente, a partir de varias pruebas, incluyendo la coagulasa, termonucleasa, y en la actualidad, PCR para los genes que codifican específicamente por la enterotoxina responsable del cuadro. El presente trabajo pretende detectar por medio de la reacc (mas) ión en cadena de la polimerasa la presencia del gen que codifica para la enterotoxina A en un grupo de cepas de Staphylococcus aureus aisladas de alimentos, así como correlacionar la presencia de este gen con la producción de las enzimas coagulasa y termonucleasa. Se analizaron 69 cepas de estafilococos, 58 provenientes de muestras de leche no pasteurizada de la Estación Experimetal Alfredo Volio Mata y 11 de la colección del Laboratorio de Alimentos y Aguas de la Facultad de Microbiología de la Universidad de Costa Rica. Se les realizó a las cepas las pruebas de coagulasa, termonucleasa y enterotoxina A, y un análisis estadístico entre los resultados obtenidos para verificar su posible asociación. Los resultados demuestran que no existe correlación entre las tres variables, no obstante, todas las cepas coagulasa positivas fueron termonucleasa pero no así a la inversa y todas las cepas enterotoxina positiva son también coagulasa y termonucleasa positivas, no así a la inversa. Lo anterior pone de manifiesto el que utilizar pruebas presuntivas o indirectas para evidenciar enterotoxigenicidad en cepas de S. aureus no es confiable y por lo tanto es recomendable realizar el análisis directo de éstas utilizando técnicas altamente sensibles y específicas, como es el PCR. Resumen en inglés Staphylococcus aureus is a pathogenic bacterium, widely distributed on nature and associated to general infection and food borne outbreaks. The relationship between this bacterium and food borne outbreaks has been done, historically, using several tests, including coagulase, thermonuclease and actually, PCR for the genes codifying for the enterotoxin responsible of clinical symptoms. The objective of this work is to detect enterotoxin A codifying gene through PCR in a gro (mas) up of S. aureus strains isolated from food samples, and also to correlate the presence of this gene with the production of coagulase and thermonuclease enzymes. A total of 69 staphylococcal strains were analyzed, 58 obtained from non pasteurized milk samples from the Estación Experimental Alfredo Volio Mata and 11 from the Food and Water Microbiology Laboratory collection, Universidad de Costa Rica. Coagulase, thermonuclease and enterotoxin A were analyzed in all the strains, and a statistical correlation was performed in order to verify possible associations. Results show that there is no correlation between the three variables, nevertheless, all coagulase positive strains were thermonuclease positive, and all enterotoxin positive strains were coagulase and thermonuclease positive, but not inversely. These results show that the use of presumptive or indirect tests for establishing entorotoxigenity of S. aureus strains is not truthful, more sensible and specific analysis, as PCR, shall be performed.

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Primeros aislamientos de Thraustochytriales (Labyrinthulomycetes, Heterokonta) de ambientes estuariales y salinos de la Argentina/ First isolations of Thraustochytriales (Labyrinthulomycetes, Heterokonta) from estuarial and saline environments of Argentina

Rosa, Silvina M.; Galvagno, Miguel A.; Vélez, Carlos G.
2006-07-01

Resumen en español Se presentan y describen cinco cepas de Thraustochytriales aisladas de dos ambientes: uno salino continental y otro estuarial. Debido a que las observaciones no coincidieron exactamente con las descripciones originales, tanto en lo morfológico como en lo ecológico, las cepas se determinaron como Thraustochytrium aff. antarcticum, Ulkenia aff. radiata y U. aff. visurgensis. Estos registros constituyen las primeras citas de Labyrinthulomycetes para Argetnina. Resumen en inglés This is the first report of Labyrinthulomycetes for Argentina. Five strains of Thraustochytriales were isolated from both, a saline continental environment and an estuarial one from Argentina. The strains were identified as Thraustochytrium aff. antarcticum, Ulkenia aff. radiata and U. aff. visurgensis because the observations did not exactly fit the original descriptions in the morphological and ecological aspects.

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Genetic diversity of Giardia intestinalis populations in Colombia

Ravid, Zaava; Duque, Sofía; Arévalo, Adriana; Nicholls, Rubén Santiago; Wasserman, Moisés
2007-03-01

Resumen en español Diversidad genética de poblaciones de Giardia intestinalis en Colombia Introducción. Giardia intestinalis es un parásito protozoario que causa la infección gastrointestinal conocida como giardiosis, la cual se transmite principalmente a través de la contaminación fecal-oral. Estudios genéticos de aislamientos de Giardia cultivados axénicamente han identificado dos grupos genéticos principales distribuidos en el mundo. En el presente estudio se analizaron 24 (mas) cepas nativas del parásito por medio de la técnica RAPD (ADN polimórfico amplificado aleatoriamente). Objetivo. Determinar el nivel de polimorfismo y la complejidad de las cepas circulantes en áreas específicas de Colombia. Materiales y métodos. Se utilizó el método RAPD debido a que permite obtener un análisis rápido, sencillo y confiable, que no requiere conocimiento previo de la genética del parásito. El análisis RAPD se realizó en cultivos continuos de aislamientos nativos recolectados en Colombia entre 1997 y 2001. Se evaluaron separadamente diversos iniciadores con el objeto de incrementar la capacidad de discriminación del método. Resultados. De las 24 cepas incluidas en el estudio, 22 se agruparon en clusters independientes. Las cepas que provenían de la misma zona geográfica, y que fueron recolectadas aproximadamente al mismo tiempo, generalmente presentaron patrones RAPD sumamente similares pero distinguibles entre sí. Se analizaron así mismo los clones aislados de una misma cepa y fue posible diferenciarlos molecularmente. Conclusión. Los resultados de las cepas estudiadas indicaron que éstas corresponden al genotipo A, y sugieren que consisten en una mezcla heterogénea de poblaciones estrechamente relacionadas. Resumen en inglés Introduction. Giardia intestinalis is a protozoan parasite that causes a gastrointestinal infection known as giardiosis, which is transmitted primarily through fecal-oral contamination. Genetic studies of axenically cultivated Giardia isolates have identified two major genetic groups distributed throughout the world. In the present study 24 native strains of the parasite were analyzed by the RAPD technique (Random Amplified Polymorphic DNA). Objective. To determine the le (mas) vel of polymorphism and the complexity of Giardia intestinalis circulating strains in specific areas of Colombia. Materials and methods. The RAPD method was used, as it allows for a quick, simple and reliable analysis that requires no prior knowledge of the genetics of the parasite. A RAPD analysis was conducted on native isolates collected in Colombia between 1997 and 2001, established in continuous cultures. Several primers were tested separately, in order to enhance the capacity for discrimination of the method. Results. Of the 24 strains that were included in the study, 22 were arranged in independent clusters. The strains that were from the same geographic area and collected at about the same time, generally displayed highly similar but distinguishable RAPD patterns. Clones isolated from a strain were analyzed as well, and it was possible to differentiate them molecularly. Conclusion. The studied strains showed to belong to genotype A .The results suggest that the Colombian strains studied consist of a heterogeneous mixture of closely related populations.

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Seroprevalencia de la infección por Trypanosoma cruzi en la población rural de Miraflores, estado Monagas: Estabilidad y diferencia de reactividad de epimastigotes fijados/ Seroprevalence of Trypanosoma cruzi infection in the rural population of Miraflores, Monagas State, Venezuela: Stability and reactivity differences of fixed epimastigotes

Berrizbeitia, Mariolga; Aguilera, Giovanna; Brian, Ward; Rodríguez, Jessicca; Jorquera, Alicia; Ndao, Momar
2010-06-01

Resumen en español Se evaluó la seroprevalencia de anticuerpos IgG anti-Trypanosoma cruzi, en la población rural de Miraflores, estado Monagas. En el estudio participaron 106 individuos (edades: 4 a 79 años) de cualquier género. El diagnóstico serológico fue realizado mediante la prueba de ELISA utilizando antígenos fijados de las formas epimastigotes de T. cruzi. Se evaluó la estabilidad del antígeno utilizado y las diferencias en la reactividad de dos cepas distintas de T. cruzi (mas) (complejo Tulahuen-Brasil y cepa RG1). La seropositividad de anticuerpos de tipo IgG anti-T. cruzi, con la cepa RG1 y la mezcla de cepas Tulahuen-Brasil, fue 2,8%. Se observó una correlación positiva entre la edad de los pacientes y la densidad óptica de la determinación de anticuerpos tipo IgG anti-T. cruzi presentada por la prueba de ELISA, para las dos cepas. La cepa Tulahuen-Brasil mostró mayor reactividad que aquella obtenida con la cepa RG1. Los antígenos fijados (mezcla de cepas Tulahuen-Brasil) mantuvieron su estabilidad y reactividad por un período de 5 años, lo cual hace de este tipo de antígeno un excelente candidato para las pruebas de diagnóstico. En la zona de estudio estuvieron presentes las variables epidemiológicas de riesgo para la reactivación de la infección en esta región de Venezuela. Resumen en inglés The seroprevalence of anti-Trypanosoma cruzi IgG was evaluated in the rural population of Miraflores, Monagas State. The study included 106 individuals (ages: 4 to 79 years) of any sex. The serologic diagnosis was done through the ELISA test using as antigen fixed T. cruzi epimastigote forms. The stability of the antigen used was evaluated, as well as the differences in reactivity of the two different T. cruzi strains used (the Tulahuen-Brasil complex, and the RG1 strains (mas) ). Seropositivity of anti-T. cruzi IgG type antibodies with the RG1 strains and the mixture of Tulahuen-Brasil strains was 2.8%. There was a positive relationship between the age of patients and the optical density of the anti-T. cruzi IgG type antibody determination shown by the ELISA test for both strains. The Tulahuen-Brasil strains showed greater reactivity than the one seen with the RG1 strain. Fixed antigens (mixture of Tulahuen-Brasil strains) maintained their stability and reactivity during a five-year period, which means that this antigen is an excellent candidate for diagnostic tests. The epidemiological risk variables for the reactivation of this infection were present in this region of Venezuela.

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Susceptibilidad antimicrobiana y patrones de resistencia de Staphylococcus aureus aislados de pacientes y portadores en la ciudad de Valdivia, Chile/ Antimicrobial susceptibility and resistance patterns of Staphylococcus aureus isolated from patients and carriers in Valdivia city, Chile

Otth R, Laura; Wilson Sch, Myra; Bustamante H, Natalia; Fernández J, Heríberto; Otth L, Carola
2008-06-01

Resumen en español La susceptibilidad in vitro de Staphylococcus aureus adquirido, tanto en el ambiente hospitalario como en la comunidad, debe ser monitorizada periódicamente por su continua evolución. Objetivos: Conocer la susceptibilidad antimicrobiana de cepas de S. aureus aisladas en Valdivia, determinar la prevalencia de cepas resistentes a meticilina y sus respectivos patrones de resistencia, analizar la evolución de esta susceptibilidad a través de los años. Material y Métodos (mas) : Se evaluaron 278 cepas de S. aureus: 136 obtenidas de pacientes hospitalizados, 50 de pacientes ambulatorios y 92 de portadores. Los antimicrobianos ensayados fueron: penicilina, oxacilina, vancomicina, gentamicina, ciprofloxacina, lincomicina y eritromicina Resumen en inglés In vitro susceptibility of nosocomial and community acquired strains of Staphylococcus aureus must be periodically evaluated because of its continuous evolution. Aim: To know the antimicrobial susceptibility of S. aureus isolated in Valdivia, to determine the prevalence of methicillin resistance and global patterns of resistance and to compare the evolution of the susceptibility along the years. Material and Methods: A total of 278 S. aureus strains were evaluated: 136 ob (mas) tained from hospitalized patients, 50 belonged to outpatients and 92 to healthy carriers. Antimicrobial agents tested were: penicillin, oxacillin, vancomycin, gentamycin, ciprofloxacin, lincomycin and erythromycin. Results: Thirty three, 28 and 1.1% of strains isolated from hospitalized, outpatients and carriers, respectively, were methicillin-resistant. Six resistance patterns were found. No vancomycin resistant strain was isolated. Comment: It is worrisome that 2% of S. aureus strains obtained from hospitalized patients showed intermediate resistance to vancomycin

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Evaluación del sistema API Coryne, versión 2.0, para la identificación de bacilos gram-positivos difteroides de importancia clínica/ Evaluation of API Coryne system, version 2.0, for diphteroid gram-positive rods identification with clinical relevance

Almuzara, M. N.; De Mier, C.; Rodríguez, C. R.; Famiglietti, A. M. R.; Vay, C. A.
2006-12-01

Resumen en español Se evaluó la capacidad del sistema API Coryne, versión 2.0, (bioMérieux) para identificar 178 cepas de bacilos gram-positivos: 78 del género Corynebacterium y 100 de géneros relacionados, aislados de muestras clínicas de pacientes atendidos en el Hospital de Clínicas José de San Martín (UBA) en el período 1995-2004. Los aislamientos fueron identificados de acuerdo al esquema de von Graevenitz y Funke. Sobre un total de 178 cepas, 162 (91%) fueron correctamente i (mas) dentificadas a nivel de género y especie (IC95 = 85,6- 94,6 ), 44 de ellas (24,7%) requirieron el uso de pruebas adicionales para la identificación definitiva. En 16 cepas (9%) no se llegó a la identificación correcta (IC95= 5,4-14,4 ) y no hubo cepas no identificadas. API Coryne versión 2.0 es un sistema útil para la identificación de la mayoría de las especies de Corynebacterium de importancia clínica: Corynebacterium jeikeium, Corynebacterium urealyticum, Corynebacterium striatum, Corynebacterium pseudodiphtheriticum, Corynebacterium amycolatum y de las especies relacionadas Arcanobacterium haemolyticum, Dermabacter hominis, Listeria monocytogenes, entre otros. No obstante para bacilos gram-positivos difteroides que presentan pigmento amarillo (Aureobacterium spp, Leifsonia aquatica, Microbacterium spp. y Cellulomonas spp.) y para bacilos gram-positivos ácido resistentes (Rhodococcus, Gordonia, Tsukamurella y Nocardia), la utilidad en la identificación del género es limitada. Resumen en inglés The ability of the API Coryne system, version 2.0, to identify 178 strains of gram-positive rods was evaluated. Seventy eight isolates belonged to genus Corynebacterium and one hundred to related genera, all strains were isolated from clinical samples at the Laboratory of Bacteriology, Hospital de Clínicas José de San Martín (UBA) between 1995 and 2004.The isolates were identified according to von Graevenitz and Funke&'s scheme. One hundred and sixty two out of 178 str (mas) ains (91%) were correctly identified at genus and species level (IC95= 85.6-94.6), in 44 of them (24.7%) additional tests were needed to final identification. Sixteen strains (9%) were not correctly identified (IC95=5.4-14.4); none of the 178 strains remained unidentified. The API Coryne system, version 2.0, is useful to identify the majority of Corynebacterium species with clinical relevance: Corynebacterium jeikeium, Corynebacterium urealyticum, Corynebacterium striatum, Corynebacterium pseudodiphtheriticum, Corynebacterium amycolatum and related species such as Arcanobacterium haemolyticum, Dermabacter hominis, Listeria monocytogenes, among others. Nevertheless for yellow-pigmented diphteroid gram-positive rods (Aureobacterium spp., Leifsonia aquatica, Microbacterium spp. and Cellulomonas spp.) and for acid fast gram-positive rods (Rhodococcus, Gordonia, Tsukamurella and Nocardia) the identification usefulness the system is limited.

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Enteropatogenicidad de bacterias aisladas de peces, del agua y plancton de su entorno en Venezuela/ Enteropathogenicity of bacteria isolated from fish, water and plancton from their environment in Venezuela

Leal, Yubiry; Reyes, Mayra; Álvarez, Julia D; Obregón, José; Viña, Xiomara
2009-10-01

Resumen en español Las enfermedades de transmisión alimentaria asociadas al consumo de pescado, constituyen en la actualidad un grave problema sanitario en Venezuela, ya que la aparición de patologías gastrointestinales se ha hecho cada vez más frecuente, quizás originada directamente por miembros de la bacterioflora de peces dulceacuícolas. En tal sentido, el objetivo de esta investigación se centró en la determinación de la enteropatogenicidad, específicamente la citotoxicidad y (mas) enterotoxicidad de cepas bacterianas aisladas de tilapias, truchas arco iris y cachamas, provenientes de granjas y del medio silvestre. Para ello, se emplearon un total de 12 cepas, dos por cada especie bacteriana: Aeromonas hydrophila, Escherichia coli, Klebsiella pneumoniae, Pseudomonas fluorescens, Plesiomonas shigelloides y Vibrio cholerae, empleando la línea celular Vero y a través del modelo de inoculación en ratones lactantes. La producción de enterotoxinas resultó positiva para el 42% de las cepas, observándose distensión abdominal con fluido intestinal de color blanquecino en ratones inoculados con A. hydrophila, K. pneumoniae y V. cholerae, mientras que en aquellos inoculados con E. coli, el fluido se observó hemorrágico. El 100% de las cepas resultaron citotóxicas en el ensayo con células Vero, produciendo alteraciones intra (granulaciones tóxicas) y extracelulares (disgregación y cambios en la morfología celular). Estos resultados permiten inferir sobre la existencia de un vínculo entre el consumo de pescado y la aparición de enfermedades en el humano. Resumen en inglés Diseases transmitted through food products associated to fish consumption, actually constitute a serious sanitary problem in Venezuela, because gastrointestinal pathologies are more frequent, maybe originated directly from members of freshwater fish bacterioflora. For this, the objective of this research was focused in the enteropathogenicity determination, specifically citotoxicity and enterotoxicity of strains isolated from tilapias, rainbow trouts and cachamas, capture (mas) d from farms and natural environments. In that sense, 12 strains were used, two of each of the following species: Aeromonas hydrophila, Escherichia coli, Klebsiella pneumoniae, Pseudomonas fluorescens, Plesiomonas shigelloides and Vibrio cholerae, using a Vero cellular line and the suckling mouse model. The enterotoxin production resulted positive for 42% of the strains, observing abdominal distension with a whitish intestinal fluid in mice inoculated with Aeromonas hydrophila, Klebsiella pneumoniae and Vibrio cholerae, while in those inoculated with E. coli the fluid was hemorraghic. All the strains resulted citotoxic in the trial with Vero cells, producing intracellular (toxic granulations) and extra cellular alterations (desegregation and changes in the cellular morphology). These results allow the inference that there is a relation between fish consumption and the appearance of disease in humans.

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Identificación, cuantificación y determinación del perfil de sensibilidad a antibióticos de bacterias prebióticas adicionadas a productos de consumo frecuente en Costa Rica/ Identification, quantification and antimicrobial susceptibility pattern of probiotic bacteria added to common use food products in Costa Rica

Córdoba, Manuela; Chaves, Carolina; Arias, María Laura
2009-06-01

Resumen en español En los últimos años, debido a la alta demanda de los productos adicionados con probióticos y los múltiples beneficios nutricionales y terapéuticos asociados, la investigación sobre estos microorganismos ha progresado considerablemente, se han realizado avances notables en su selección y caracterización. De manera general, diversas entidades como la Organización Mundial de la Salud (OMS) y la Organización de las Naciones Unidas para la agricultura y la alimentaci (mas) ón (FAO) recomiendan que se declare en la etiqueta del producto, tanto la especie como la cantidad de microorganismos probióticos viables presentes. En este trabajo se analizaron seis productos adicionados con probióticos, con el fin de evaluar su concentración a lo largo de la vida útil del producto, se identificaron las cepas aisladas para corroborar la información declarada en la etiqueta y se determinó su perfil de susceptibilidad a antibióticos. Como resultado del análisis se encontró que las cepas adicionadas a los productos evaluados se mantienen en concentraciones aceptables durante los 28 días de vida útil de los productos. La identificación de las cepas aisladas no coincidió, en varios casos, con la estipulada por la etiqueta, no obstante, el método utilizado se basa en la capacidad de fermentar carbohidratos y no en pruebas genotípicas. Con respecto a los perfiles de susceptibilidad encontrados para las cepas analizadas, son necesarios estudios adicionales que establezcan la naturaleza intrínseca o adquirida de los determinantes de resistencia, y que evidencien si estos están codificados en elementos transferibles entre bacterias Resumen en inglés In the last years, due to the high demand of food products supplemented with probiotics and the multiple nutritional and therapeutic benefits associated with them, research on these microorganisms has advanced considerably, including their selection and characterization. As a general recommendation, several entities as World Health Organization (WHO) and United Nations Organization for Agriculture and Food recommend that the specification of the alive species contained an (mas) d their number shall appear in the label of the product. In the present study, six different commercially available products, supplemented with probiotics were analyzed, in order to evaluate the concentration of microorganisms through the shelf life of the product, identify the strains isolated and determine the antibiotic susceptibility pattern of these. Results demonstrated that the strains isolated kept acceptable concentrations during the 28 days of storage. Nevertheless, the identification of these strains variated from the one reported on the label on several of the products tested. This can be due to the commercial method used for the identifications, which is based in the carbohydrate fermentation pattern and not in genotypic trials. The antimicrobials’ susceptibility patterns found show that further research shall be performed in order to establish the intrinsic or acquired nature of the resistance determinants, and if these are codified by transferable elements among bacteria

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Amibiasis: Importancia de su diagnóstico y tratamiento. Mini-revisión/ Amebiasis: importance of the diagnosis and treatment. Minireview

Araujo, José; García, María Eugenia; Díaz-Suárez, Odelis; Urdaneta, Haidee
2008-06-01

Resumen en español El protozoario E. histolytica es el agente etiológico de la amibiasis humana; la identificación de su patogenicidad ha sido de gran ayuda en la búsqueda de antígenos importantes para su inmunodiagnóstico e inmunoprofilaxia. En 1995 se describió el aislamiento y axenización de las dos primeras cepas de E. histolytica venezolanas procedentes de pacientes sintomáticos, denominadas IULA: 1092:1 e IULA: 0593:2. Estas cepas han sido evaluadas a través de estudios de pe (mas) rfiles electroforéticos, demostrándose la presencia del zimodemo de tipo II característico de cepas patógenas. También han mostrado ser de alta virulencia. Además, presentan un complejo patrón de reactividad y la presencia de un antígeno marcador de patogenicidad; el análisis isoenzimático ha mostrado correlación con el análisis genotípico, indicando una organización genotípica propia de una cepa patógena. Con esta cepa se han podido evaluar todos los casos de amibiasis remitidos al Instituto de Inmunología Clínica de la Universidad de Los Andes, y han sido de utilidad en otras localidades al emplear sus antígenos para evaluar poblaciones urbanas e incluso indígenas, por lo que pueden ser usadas como cepas nativas de referencia en los ensayos de diagnóstico y profilaxis. Las limitaciones del examen microscópico, específicamente los falsos diagnósticos de amibiasis, y su incapacidad para discriminar entre infecciones por E. histolytica y E. dispar, han conducido al desarrollo de procedimientos de laboratorio que permiten la detección de componentes de las especies presentes. El éxito de tales procedimientos permitiría una disminución de tratamientos innecesarios, los cuales pueden llevar a resistencia ante las diferentes drogas antiamibianas. Resumen en inglés The protozoa E. histolytica is the etiologic agent of human amebiasis, the identification of its pathogenicity has been of great aid in the search of important antigens for immunodiagnostic and inmunoprofilaxis. In 1995 the isolation and axenization of the first two strains of Venezuelan E. histolytica were described from symptomatic patients, which were denominated: IULA 1092:1 and IULA: 0593:2 These strains have been evaluated through studies of electrophoretic profiles (mas) , demonstrating the presence of type II zymodemes, characteristic of pathogenic strains. Also, they have shown to be of high virulence, they present a complex pattern of reactivity and the presence of a marker antigen of pathogenicity. The isoenzymatic analysis has shown correlation with the genotypic analysis, showing a genotypic organization typical of a pathogenic strain. With this strain, it has been possible to evaluate all the amebiasis cases sent to the Institute of Clinical Immunology of Universidad de Los Andes, in Merida, Venezuela. These strains have been useful, here, as well as in other sites, when using their antigens to evaluate urban and even indigenous populations. They can be used, like native strains of reference, in diagnostic tests and prophylaxis for this parasitosis. The limitations of the microscopic analysis, specifically, the false amebiasis diagnosis and its inability to discriminate between infections caused by E. histolytica and E. dispar have led to the development of laboratory procedures that allow for the detection of components of the species present. The success of such procedures would result in a diminution of unnecessary treatments, which could be the cause of antiamoebic drug resistance.

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Aislamiento de Escherichia coli O145:NM en casos de síndrome urémico hemolítico/ Escherichia coli 0145-.NM isolated from hemolytic uremic syndrome cases

Gómez, Diana; Chinen, Isabel; Zotta, Claudio Marcelo; Carbonari, Carolina; Lavayén, Silvina; Monzani, Victoria; Deza, Natalia; Morvay, Laura; Cepeda, Marcela; Rivas, Marta
2010-03-01

Resumen en español En Argentina se notifican más de 500 nuevos casos de síndrome urémico hemolítico (SUH) anuales. El objetivo del trabajo fue investigar epidemiológicamente casos de SUH y contactos de los que se aislaron cepas de STEC O145:NM que pertenecían a un mismo cluster. Para detectar STEC se realizó PCR-múltiple para amplificar genes de toxinas Shiga 1 y 2, y otros marcadores de virulencia como eae y ehxA. Se subtipificó STEC por separación por electroforesis de campos pu (mas) lsados (XbaI-PFGE). Entre enero y febrero de 2006, en tres casos de SUH y un contacto familiar conviviente se identificó STEC O145:NM. Genotípicamente se caracterizaron como productores de stx2, eae+ y ehxA+. Todas las cepas presentaron el mismo patrón por XbaI-PFGE (AREXSX0 1.0207) y por B/nI-PFGE (AREXSA26.0018). Estas cepas pertenecieron a un mismo cluster, diseminado en distintos barrios de la ciudad de Mar del Plata. Los datos de la investigación epidemiológica fueron incompletos para establecer un nexo entre los casos. Sin embargo, no se descarta la posibilidad de ocurrencia de un brote difuso. Se destaca la importancia que tiene el sistema de vigilancia de laboratorio en tiempo real mediante PFGE como mecanismo de alerta que sirve para afianzar los resultados con los datos de epidemiología. Resumen en inglés More than 500 new cases of hemolytic uremic syndrome (HUS) are annually reported in Argentina. The aim of this work was to carry out epidemiological studies on cases of HUS and their household contacts that were isolated from STEC O145 strains: NM belonging to the same cluster. In order to detect STEC, Multiplex PCR was performed to amplify Shiga toxin 1 and 2 genes and other virulence markers like eae and ehxA. STEC was subtypified by means of separation by pulsed field (mas) electrophoresis (PFGE-XbaI). Between January and February 2006, STEC O145:NM strains were identified in three cases of HUS and one household contact. Genotypically, they were characterized as producing stx2, eae+ and ehxA +. All strains showed the same pattern by PFGE-XbaI (AREXSX01.0207) and BlnI-PFGE (AREXSA26.0018). These strains belonged to the same cluster, scattered in different areas of the city of Mar del Plata. Data from epidemiological research were not enough to establish a link between the cases. However, the possibility of occurrence of a diffuse outbreak. is not ruled out The importance of a laboratory surveillance system in real time by PFGE is stressed, as a warning mechanism that serves to strengthen the results with epidemiologic data.

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Etiología bacteriana de la diarrea aguda en pacientes pediátricos/ Bacterial etiology of acute diarrhea in pediatric patients

Giugno, Silvina; Oderiz, Sebastián
2010-03-01

Resumen en español La diarrea aguda es una causa importante de morbilidad y mortalidad en países en desarrollo. Sólo requiere tratamiento antimicrobiano en situaciones puntuales y el uso adecuado de los mismos depende del conocimiento previo de la epidemiología local. Para conocer estos parámetros se estudiaron en forma retrospectiva los resultados bacteriológicos de 7.075 muestras de materia fecal de niños ambulatorios hasta 15 años, en el período 2001-2003, atendidos en el Hospita (mas) l de Niños de La Plata. Se aislaron 1.221 bacterias enteropatógenas (17,26%). Los patógenos identificados por métodos estándar fueron: Shigella flexneri(27%), Shigella sonnei(21,2%), Campylobacterspp. (30,1%), Aeromonas spp.(9,4%), Salmonella spp. (5,4%), Escheríchia coli enteropatógena (5,7%), Escheríchia coli enteroinvasiva (0,9%) y Escheríchia coliO157 (0,4%). No se aislaron cepas de Shigella dysenteriae, Shigella boydii ni Yersinia spp. Las cepas de Shigella flexneri presentaron una alta resistencia: ampicilina (92,4%, 89,2% y 91,9%), cotrimoxazol (51,5%, 50% y 44,4%) y cloranfenicol (73,8%, 85,9% y 79,2%) en 2001, 2002 y 2003, respectivamente. En el caso de Shigella sonnei, la resistencia a ampicilina fue menor (39,4%, 20,6% y 12,9%), la resistencia a cotrimoxazol fue similar (60,6%, 54,3% y 38,7%) y para cloranfenicol mucho menor aún (6%, 2,9% y 3,3%) en los mismos años. No se aislaron cepas resistentes a ciprofloxacina, nitrofuranos ni cefalosporinas de tercera generación en el período de estudio. Resumen en inglés Acute diarrhea is an important cause of morbidity and mortality in developing countries, and in some cases, it requires antimicrobial therapy .The use of antibiotics needs a previous knowledge of local epidemiology. In order to know these parameters, the result of enteropathogenic bacteria isolated from 7.075 fecal samples from ambulatory patients up to 15 years old, assisted at the Hospital de Niños de La Plata from 2001 to 2003 was retrospectively studied. A total of 1 (mas) ,221 enteropathogenic bacteria were isolated (17.26%). The pathogens identified by standard methods were Shigella flexneri (27%), Shigella sonnei (21.2%), Campylobacter spp.(30.1%), Aeromonas spp.(9.4%), Salmonella spp. (5.4%), enteropathogenic Escherichia coli ( 5.7% ), enteroinvasive Escherichia coli (0.9%) and Escherichia coli 0157 (0.4%). Strains from Shigella dysenteriae, Shigella boydii and Yersinia spp were not isolated in this study. Shigella flexneri strains were resistant to ampicillin (92.4%, 89.2%, 91.9%), cotrimoxazole (51.5%, 50%, 44%) and chloramphenicol (73.8%, 85.9%, 79.2%) for 2001, 2002 and 2003 respectively. Shigella sonnei strains were resistant to ampicillin (39.4%, 20.6%,12.9%), cotrimoxazole (60.6%, 54.3% 38.7%) and chloramphenicol (6%, 2.9%, 3.3%) for each year. Strains resistant to ciprofloxacin, nitrofurans and third generation cephalosporins were not isolated.

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Estudio multicéntrico de la vigilancia de la susceptibilidad in vitro a tigeciclina en Santiago de Chile/ Multicenter study on the monitoring of in vitro susceptibility to tigeeyeline in Santiago, Chile

García C, Patricia; Juliet L, Chrystal; Fernández V, Alejandra; San Martín S, Marcela; Cifuentes D, Marcela; Porte T, Lorena; Braun J, Stephanie; Castillo D, Loriana; Vechiola H, Maggie; Tapia P, Cecilia; Sakurada Z, Andrea; Chanqueo C, Leonardo; Lam E, Marusella; Espinoza P, Mónica; Curcio F, Daniel
2009-06-01

Resumen en español Para conocer la susceptibilidad a tigeciclina por difusión en agar en nueve hospitales de Santiago y comparar la susceptibilidad con otros antimicrobianos, se diseñó este estudio multicéntrico. Cada centro estudió 20 cepas mensualmente. Las intermedias, resistentes y 10%o de las susceptibles se re-testearon y estudiaron por microdilución en caldo. Se incluyeron 2.304 cepas. Fueron susceptibles a tigeciclina Strep-tococcus sp (100%o), Enterococcus sp (100%), E. coli (mas) (100%o), Staphylococcus sp (99,8%), Klebsiella pneumoniae (93%) y Acinetobacter baumannii (80%). En Proteus, Providencia y Morganella la susceptibilidad fue 4%o. Klebsiella resistente a cefotaxima y Acinetobacter resistente a imipenem, 95%o y 80%o fueron susceptibles a tigeciclina, respectivamente. La concordancia en cepas susceptibles y en las enviadas como resistentes o intermedias (A. baumannii) fue 100%o y 27%o respectivamente. El re-testeo confirmó que la mayoría eran susceptibles. Los patrones de susceptibilidad bacteriana muestran muy buena actividad in vitro a tigeciclina. La resistencia in vitro de A. baumannii por difusión en agar debe interpretarse con precaución Resumen en inglés The objective of this multicenter study was to determine tigeeyeline susceptibility rates, measured by agar diffusion, in nine hospitals in Santiago and to compare these rates with other antimicrobials. Each center studied 20 strains per month. All intermedíate and fully resistant strains as well as 10% of susceptibile strains were also studied by the broth microdilution method. Overall, 2301 strains were studied displaying the foliowing susceptibility rates for tigeeyel (mas) ine: 100% for Streptococcus sp, Enterococcus sp, and E. coli respectively, 99.8% for Staphylococcus sp, 93% for Klebsiella and 80% for Acinetobacter baumarmii. For Proteus, Providencia and Morganella the susceptibility rates were 4%. For cefotaxime-resistant Klebsiella and imipenem-resistant A. baumarmii susceptibility rates were 95% and 80% respectively. The agar diffusion and broth dilution method were 100% concordant for tigeeyeline susceptible strains but only 27% for resistant or intermedíate strains represented mostly by Acinetobacter baumannii. The majority of these strains (57/59) proved to be susceptible after retesting. The great majority (96,6%) of strains tested from nine Chilean hospitals proved to be susceptible to tigeeyeline with exception for Proteus, Providencia and Morganella (66% resistance). Using the agar diffusion method for measuring tigeeyeline susceptibility to A. baumannii may be misleading

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Aislamiento deEnterococcus faecium resistente a vancomicina con genotipo vanB en el Hospital Clínico Regional de Concepción/ ISOLATION OF VANCOMYCIN RESISTANT Enterococcus faecium WITH GENOTYPE vanB AT THE HOSPITAL CLINICO REGIONAL DE CONCEPCIÓN

MELLA M, SERGIO; SEPÚLVEDA A, MARCELA; ACOSTA V, PAMELA; BELLO T, HELIA; DOMÍNGUEZ Y, MARIANA; GONZÁLEZ R, GERARDO; ZEMELMAN Z, RAÚL; COFRÉ C, OMAR
2002-01-01

Resumen en español La resistencia bacteriana a los agentes antimicrobianos ha aumentado durante las últimas décadas. De particular importancia es la descripción de aislamientos de Enterococcus resistente a vancomicina (EVR), de reciente y progresiva descripción en nuestro país. Comunicamos el aislamiento de dos cepas de E. faecium resistentes a vancomicina de pacientes colonizados por este microorganismo en el Hospital Clínico Regional de Concepción. El estudio feno y genotípico fue (mas) positivo para vanB, además ambos aislamientos presentaron similitud genética en un estudio de tipificación molecular por rep-PCR. Interesantemente el aislamiento de estas cepas precedió al aislamiento de EVR según el protocolo ministerial. Esta diferencia puede explicarse por los factores de riesgo que presentaron los pacientes estudiados Resumen en inglés The antibiotic resistance among bacteria has increased during the last decades. Of particular importance was the report of vancomycin-resistant Enterococcus isolates (VRE), recently described in our country. In this work we report the isolation of two strains of E. faecium resistant to vancomycin from colonized patients admitted to the Hospital Regional de Concepción. The phenotyping and genotyping studies gave positive results for VanB type of vancomycin resistance. Bot (mas) h strains showed genetic similarity when were molecular typed by rep-PCR. Interestingly, the isolation of this strains was previous to the isolation of VRE according to the protocols delineated by the Health Ministry. This difference may be explained by the risk factors exhibited by the colonized patients

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In vitro mating of Colombian isolates of the Cryptococcus neoformans species complex/ Determinación in vitro de la pareja sexual en aislamientos del complejo Cryptococcus neoformans

Escandón, Patricia; Ngamskulrungroj, Popchai; Meyer, Wieland; Castañeda, Elizabeth
2007-06-01

Resumen en español Introducción. En el complejo Cryptococcus neoformans se reconocen dos especies y cinco serotipos: C. neoformans (var. grubii, serotipo A; var. neoformans, serotipo D y un híbrido, serotipo AD) y C. gattii (serotipos B y C). La pareja sexual a y alfa es controlada por un solo locus, y la pareja sexual alfa es la más prevalente en los serotipos A y D, y es convencionalmente determinada mediante reacción en cadena de la polimerasa. Objetivo. Evaluar la habilidad de aisla (mas) mientos colombianos de C. neoformans para aparearse in vitro con aislamientos control de la pareja sexual opuesta. Materiales y métodos. Treinta y tres aislamientos clínicos de C. neoformans var. grubii serotipo A, 4 de la var. neoformans serotipo D, todos pareja sexual alfa, y 16 aislamientos clínicos de C. gattii, 13 serotipo B (pareja sexual a) y 3 serotipo C (pareja sexual alfa ), se mezclaron, en agar jugo V8 modificado, con cepas control para determinar la pareja sexual in vitro. Resultados. Los estudios de apareamiento mostraron que 9 de 33 (27,3%) aislamientos serotipo A y 6 de 13 (46,2%) aislamientos serotipo B tuvieron la capacidad de aparearse con las cepas control. Todos los aislamientos del serotipo A que presentaron apareamiento eran pareja sexual alfa y los del serotipo B eran pareja sexual a. Microscópicamente se observaron conexiones en gancho, basidias y basidiosporas, estructuras que establecieron que se había realizado el proceso de apareamiento. Conclusión. Este acercamiento provee por primera vez la capacidad de que los aislamientos colombianos de C. neoformans se apareen in vitro con cepas control lo cual tiene importancia en el estudio de la diseminación del hongo. Resumen en inglés Introduction. Within the Cryptococcus neoformans species complex, two species and five serotypes are recognized: C. neoformans (var. grubii, serotype A; var. neoformans, serotype D and a hybrid, serotype AD) and C. gattii (serotypes B and C). Mating types a and alpha are designated by a single locus, with the mating type alpha being most prevalent in serotype A and D strains. Objective. To evaluate the ability of Colombian isolates of the C. neoformans species complex to (mas) mate in vitro with tester strains of the opposite mating type. Materials and methods. Fifty three clinical isolates were included in this study, 33 C. neoformans var. grubii serotype A, 4 C. neoformans var. neoformans serotype D, all mating type alpha, and 16 C. gattii, 13 serotype B (mating type a) and 3 serotype C (mating type alpha), were mixed on V8 juice agar, using a modified method, with the appropriate tester strains to determine the mating types in vitro. Results. Mating studies revealed that 9 of 33 (27.3%) serotype A isolates and 6 of 13 (46.2%) serotype B isolates were able to mate. Clamp connections and basidia with basidiospores were observed microscopically, indicating that the mating process had occurred. All mating competent serotype A strains were mating type alpha and the serotype B mating competent strains were mating type a. Conclusion. This is the first report of the determination of the mating ability of Colombian Cryptococcus neoformans isolates to mate in vitro with appropriate tester strains, which is of great importance to study the propagation of the fungus around the globe.

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Variation in the number of EPIYA-C repeats in CagA protein from Colombian Helicobacter pylori strains and its ability middle to induce hummingbird phenotype in gastric epithelial cells/ Variación en el número de repeticiones EPIYA-C en la proteína CagA de aislamientos colombianos de Helicobacter pylori y su capacidad para inducir fenotipo colibrí en células epiteliales gástricas

Quiroga, Andrés Javier; Huertas, Antonio; Cómbita, Alba Lucía; Bravo, María Mercedes
2010-06-01

Resumen en español Introducción. En los aislamientos de Helicobacter pylori del hemisferio occidental, se ha observado que el número de repeticiones EPIYA-C en la proteína CagA es un factor de riesgo para cáncer gástrico. La proteína CagA es introducida en la célula epitelial y, posteriormente, es fosforilada en las tirosinas presentes en los motivos EPIYA e induce rearreglos en el citoesqueleto. Objetivos. Nuestro propósito fue evaluar el número de repeticiones EPIYA-C y la habili (mas) dad para inducir rearreglos en el citoesqueleto en los aislamientos de H. pylori positivos para cagA, provenientes de pacientes colombianos con enfermedad gastroduodenal. Materiales y métodos. Mediante PCR, se analizó la región 3´ que contiene las repeticiones EPIYA-C, en 93 aislamientos de H. pylori positivos para cagA provenientes de 49 pacientes con gastritis, 17 con cáncer gástrico y 24 con úlcera duodenal. Los rearreglos del citoesqueleto se evaluaron mediante cultivos simultáneos de células AGS con las cepas de H. pylori. Resultados. En gastritis y úlcera duodenal se observó la mayor frecuencia de aislamientos con EPIYA C; los aislamientos con tres repeticiones EPIYA-C se encontraron con mayor frecuencia en cáncer gástrico. Encontramos un riesgo de cáncer gástrico significativamente mayor para individuos infectados con cepas con tres repeticiones EPIYA-C (OR=12,4; IC95% 2,32-66,3). Los aislamientos provenientes de cáncer gástrico mostraron mayores porcentajes de inducción de rearreglos en el citoesqueleto que los observados con aislamientos provenientes de gastritis (prueba de Mann-Whitney menor de 0,005). Conclusiones. La infección con cepas de H. pylori con tres repeticiones EPIYA-C puede conferir un mayor riesgo de desarrollar cáncer gástrico. Resumen en inglés Introduction. Studies using Western Helicobacter pylori strains have shown that a risk factor for gastric cancer is the number of EPIYA-C motifs in the cytotoxin-associated A protein. CagA is delivered into epithelial cells, where it becomes tyrosine phosphorylated in their EPIYA repeats and induces cytoskeleton rearrangements. Objectives. The objective of this study was to evaluate H. pylori cagA positive strains isolated from Colombian patients with gastroduodenal disea (mas) ses for the number of EPIYA-C repeats in cagA and their ability to induce cytoskeleton rearrangements in epithelial cells. Materials and methods. We analyzed the 3´ EPIYA repeats region of cagA by PCR in 93 H. pylori cagA positive strains from 49 patients with gastritis, 17 with gastric cancer, and 24 with duodenal ulcer. AGS cells exposed to the various H. pylori isolates were evaluated for rearrangements in their cytoskeleton. Results. Strains with one EPIYA-C were the most frequent in gastritis and duodenal ulcer patients. Strains with three EPIYA-C were mainly found in gastric cancer. We found a significantly higher risk of gastric cancer for individuals infected with strains harboring three EPIYA-C motifs (OR=12.4, CI95%: 2.32-66.3). Strains from gastric cancer showed significantly higher percentages of induction of cytoskeleton rearrangements in comparison with those from gastritis (p Mann-Whitney

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Prevalencia serológica del virus de influenza A en cerdos en Argentina durante la temporada 2002: evaluación mediante inhibición de la hemaglutinación y ELISA/ Seroprevalence of the swine Influenza virus in fattening pigs in Argentina in the 2002 season: evaluation by hemagglutination-inhibition and ELISA tests

Piñeyro, P.E.; Baumeister, E.; Cappuccio, J.A.; Machuca, M.A.; Quiroga, M.A.; Tedoroff, T.; Perfumo, C.J.
2010-06-01

Resumen en español Se evaluó la prevalencia serológica del virus de influenza mediante las pruebas de inhibición de la hemaglutinación (IHA) y ELISA para los subtipos H1N1 y H3N2 en 13 granjas porcinas de Argentina. Se compararon los resultados obtenidos mediante ambas pruebas en términos individuales y de establecimientos. La prevalencia individual por la técnica de IHA fue de 38,46% a 100% para H1 y de 7,69% a 100% para H3. Por la técnica de ELISA, la prevalencia individual fue de (mas) 2,33% a 6,9% para H1 y de 9,65% a 48% para H3. No se observaron diferencias significativas entre ambas técnicas a escala de granja (H1: p=0,20; H3: p=0,11). La concordancia entre las pruebas fue nula al tomar como unidad de referencia el animal (H1: 0,005; H3: 0,070), mientras que en términos de establecimiento fue escasa (H1: 0,350; H3: 0,235). Considerando la alta prevalencia individual obtenida por la prueba de IHA y la alta sensibilidad de esta técnica, se podría sugerir que en las poblaciones porcinas de la Argentina circularon cepas virales humanas o cepas porcinas con gran proximidad filogenética a las utilizadas en este estudio desde el año 2002. Resumen en inglés The seroprevalence of the Influenza virus against H1N1 and H3N2 was determined by the hemagglutination-inhibition test (HI) and a commercial swine influenza ELISA kit, in 13 Argentinean swine herds. The results of within-herd and between-herd prevalence obtained by both tests were statistically correlated. The within-herd prevalence observed by the HI test varied from 38.46 to 100% against H1 and 7.69 to 100% for H3. When the within-herd prevalence was measured with the E (mas) LISA test, it varied from 2.33 to 6.9% for H1 and 9.65 to 48% for H3. No statistical differences were observed at herd level between HI and ELISA (H1: p = 0. 20; H3: p=0.11). No agreement between HI and ELISA detected prevalence was observed when the within-herd prevalence was compared (H1: 0.005; H3: 0.070), while the agreement at herd level was considered poor (H1: 0,350; H3: 0,235). The high within-herd prevalence values observed with the HI test and the high sensibility of this test might show that human strains or swine strains phylogenetically closely related to the humans strains used in the HI test in this study have been affecting the swine population since 2002.

Scientific Electronic Library Online (Spanish)

88

Evaluación de la calidad del diagnóstico micológico: cultivos/ Quality assessment of the mycological diagnosis: cultures

Bava, Amadeo Javier; Zuiani, María Fernanda
2007-03-01

Resumen en español Se evaluó la capacidad de los laboratorios participantes del Sub Programa Micología para identificar diferentes cepas de hongos al nivel de género o especie. Tomados los resultados en conjunto, el 66% de los laboratorios identificó en forma correcta las cepas, mientras que otro 25% lo hizo en forma parcial. En el caso de los dermatofitos hubo un mayor porcentaje de respuestas correctas para el reconocimiento de Trichophyton mentagrophytes (76%) respecto de las especie (mas) s de Microsporum evaluadas: M. canis (66%) y M. gypseum (65%). Los resultados de la identificación de las especies de levaduras mostraron dos grupos diferentes: uno conformado por Candida albicans y Cryptococcus neoformans, con elevados porcentajes de respuestas correctas (87 y 95%, respectivamente) y otro por C. tropicalis y C. glabrata, que ocasionó dificultades para su correcta identificación (sólo 28 y 32% de respuestas correctas). Las especies de Aspergillus evaluadas (A. fumigatus y A. niger) fueron reconocidas en forma correcta por el 63 y 72% de los participantes. Los resultados obtenidos, si bien son considerados como aceptables, evidencian la necesidad de mejorar la capacidad evaluada, teniendo en cuenta su influencia decisiva sobre la calidad del diagnóstico micológico. Resumen en inglés The ability to identify different fungal strains at genera or specie level for participant laboratories of the Mycology Sub-Program, was evaluated. Taking into account all results as a whole, 66% of laboratories identified the strains correctly, while another 25% recognized the strains partially. Regarding dermatophytes, a higher percentage of correct responses for Trichophyton mentagrophytes recognition was observed with respect to (76%) those of the evaluated Microsporu (mas) m species: M. canis (66%) and M. gypseum (65%). The results produced by the identification of yeasts species showed 2 different groups: one constituted by Candida albicans and Cryptococcus neoformans, with higher percentages of correct responses (87 and 95%, respectively) and another one constituted by C. tropicalis and C. glabrata, which presented difficulties for their correct identification (28 and 32% correct responses). The evaluated species of Aspergillus (A. fumigatus and A. niger) were recognized by 63% and 72% of the participants. The results obtained, considered as acceptable, show the need to improve the evaluated capacity, taking into account their decisive influence on mycologic diagnosis quality.

Scientific Electronic Library Online (Spanish)

89

Influencia de la concentración inhibitoria mínima de penicilina en la acción sinérgica de su combinación con gentamicina frente a estreptococos del grupo viridans/ Influence of penicillin minimal inhibitory concentration in the synergy between penicillin and gentamicin in viridans group streptococci

Vigliarolo, L.; Ramírez, M. S.; Centrón, D.; Lopardo, H.
2007-06-01

Resumen en español Los porcentajes de resistencia a penicilina entre los estreptococos del grupo viridans han llegado a niveles superiores al 60% en algunos estudios realizados en la década pasada, y en recientes trabajos se los encontró asociados a un mayor índice de mortalidad en las bacteriemias. Aún no se conoce cuál es el nivel de concentración inhibitoria mínima de penicilina para el cual resulta imposible lograr un efecto sinérgico con algún aminoglucósido. Con este propós (mas) ito, se estudió la sensibilidad a penicilina de 28 cepas de estreptococos del grupo viridans aisladas de materiales clínicamente significativos en el Hospital de Pediatría "Prof. Dr. Juan P. Garrahan". Se seleccionaron siete aislamientos pertenecientes al grupo mitis con distintas características de sensibilidad, y con ellos se ensayó la curva de muerte frente a penicilina, gentamicina y penicilina más gentamicina, con concentraciones de penicilina por encima y por debajo de su concentración inhibitoria mínima. En ningún caso se observó sinergia cuando la concentración de penicilina fue inferior a la concentración inhibitoria mínima, al menos en este grupo particular de estreptococos que presentaron concentraciones inhibitorias mínimas de gentamicina ³ 16 µg/ml. Se encontró sinergia en cinco de las siete cepas cuando se trabajó con concentraciones de penicilina superiores a la concentración inhibitoria mínima. En las otras dos, se detectaron enzimas modificadoras de aminoglucósidos. Resumen en inglés Penicillin resistance rates higher than 60% have been recorded in viridans group streptococci by some authors during the 90's and recently such resistance was associated with higher levels of mortality in bacteremia. The lowest minimal inhibitory concentration of penicillin for which synergy with aminoglycosides is not yet possible is still unknown. In order to try to dilucidate this puzzle, a study on the susceptibility to penicillin of 28 strains of viridans group strep (mas) tococci isolated from significant samples in the Hospital de Pediatría "Prof. Dr. Juan P. Garrahan" was carried out. Seven mitis group isolates presenting different susceptibility patterns were selected for performing time-killing curves with penicillin, gentamicin, and penicillin plus gentamicin, using higher and lower penicillin concentrations than their minimal inhibitory concentrations. Synergy was not observed when the penicillin concentration was lower than the minimal inhibitory concentration, at least in these strains with minimal inhibitory concentrations of gentamicin ³ 16 µg/ml. When using penicillin in higher concentrations than the minimal inhibitory concentration, synergy was found in five of the seven strains. Aminoglycoside-modifying enzymes were found in the two other streptococci.

Scientific Electronic Library Online (Spanish)

90

Evaluación de un ensayo de RPC múltiple para diferenciar micobacterias del complejo Mycobacterium tuberculosis en un laboratorio de referencia/ Evaluation of a multiplex PCR assay to differentiate mycobacteria of the Mycobacterium tuberculosis complex in a reference laboratory

Arráiz R, Nailet; Romay B, Zolay; Faría M, Nelba
2007-04-01

Resumen en español Las micobacterias que causan tuberculosis en animales y humanos pertenecen al complejo Mycobacterium tuberculosis. Las técnicas de diagnóstico convencional, además de ser lentas y laboriosas, no permiten diferenciar entre miembros de este complejo. El objetivo de este estudio fue evaluar ensayos de RPC múltiple para contribuir a la identificación diferencial de micobacterias del complejo M. tuberculosis a partir de cultivos, en un laboratorio de referencia. Se utiliz (mas) aron oligonucleótidos partidores basados en regiones de diferencia (RD) que consisten en segmentos de ADN que están presentes en M. tuberculosis, pero que han sido eliminados diferencialmente del genoma de otros miembros del complejo M. tuberculosis. El ensayo se aplicó sobre 86 aislados clínicos de micobacterias. El patrón de amplificación permitió diferenciar entre cepas de M. tuberculosis, M. bovis y M. bovis variedad BCG en una única RPC. Este ensayo de RPC múltiple puede ser utilizado en el Laboratorio de Referencia de Diagnóstico de Tuberculosis como prueba complementaria para diferenciar micobacterias del complejo M. tuberculosis, contribuyendo a un acortamiento en el período de reporte de resultados y un tratamiento adecuado del paciente, y podría ser aplicado también en estudios epidemiológicos de transmisión zoonótica de M. bovis a humanos Resumen en inglés Mycobacteria that cause tuberculosis in animals and humans belong to the Mycobacterium tuberculosis complex. Techniques for conventional diagnosis are time-consuming and do not differentiate between different strains belonging to the M. tuberculosis complex. The aim of this study was to evaluate a multiplex PCR assay applicable to mycobacteria in culture with the capacity to differentiate different strains belonging to the M. tuberculosis complex in a reference laboratory (mas) . Primers based on genomics regions of difference (RD) consisting in DNA segments that are present in M. tuberculosis, but differentially deleted in several members of M. tuberculosis complex were used in a PCR assay. The test was applied to 86 clinical isolates of mycobacteria. The pattern of amplification allowed differentiating between M. tuberculosis, M. bovis and M. bovis BCG in a single PCR reaction. This PCR multiplex assay may be used in a Reference Laboratory of Tuberculosis Diagnosis as a complementary test to differentiate mycobacteria strains belonging to the M. tuberculosis complex. This test significantly reduces the time period between culture and strain identification, and thus for could favor the adoption of better strain specific antimycobacterial regimens as well as identification of zoonotic transmission of M. bovis to humans

Scientific Electronic Library Online (Spanish)

91

Yeast population dynamics during the fermentation and biological aging of sherry wines

Esteve Zarzoso, Braulio; Peris Torán, María José; García Maiquez, E; Uruburu, Federico; Querol, Amparo
2001-05-01

Digital.CSIC (Spain)

92

Wine Yeast Strains Engineered for Glycogen Overproduction Display Enhanced Viability under Glucose Deprivation Conditions

Pérez Torrado, R; Gimeno Alcañiz, José Vicente; Matallana, Emilia

We used metabolic engineering to produce wine yeasts with enhanced resistance to glucose deprivation conditions. Glycogen metabolism was genetically modified to overproduce glycogen by increasing the glycogen synthase activity and eliminating glycogen phosphorylase activity. All of the modified stra...

DRIVER (Spanish)

94

Widespread occurrence of non-phosphorylating glyceraldehyde-3-phosphate dehydrogenase among gram-positive bacteria | Amplia distribución de la gliceraldehído-3-fosfato deshidrogenasa no-fosforilante entre las bacterias gram-positivas

Iddar, Abdelghani; Valverde, Federico; Assobhei, Omar; Serrano, Aurelio; Soukri, Abdelaziz

The non-phosphorylating glyceraldehyde 3-phosphate dehydrogenase (GAPDHN, NADP+ -specific, EC 1.2.1.9) is present in green eukaryotes and some Streptococcus strains. The present report describes the results of activity and immunoblot analyses, which were used to generate the first survey of bacteria...

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97

Vigilancia de la resistencia de Neisseria gonorrhoeae en un hospital de la provincia de Santa Fe, Argentina: 1997-2004/ Resistance surveillance of Neisseria gonorrhoeae in a hospital in Santa Fe province, Argentina: 1997-2004

De Los A. Méndez, E.; Morano, S. T.; Mollerach, A. S.; Mendosa, M. A.; Ahumada, C.; Pagano, I.; Oviedo, C.; Galarza, P.
2008-09-01

Resumen en español Se determinaron los fenotipos de resistencia caracterizados por la concentración inhibitoria mínima, la difusión con discos y la producción de β-lactamasa de 434 aislamientos de Neisseria gonorrhoeae obtenidos de pacientes atendidos en el Servicio de Enfermedades de Transmisión Sexual del Hospital Dr. José María Cullen, Santa Fe, Argentina. Se realizaron pruebas de sensibilidad a los siguientes antimicrobianos: penicilina, tetraciclina, ciprofloxacina, especti (mas) nomicina, azitromicina y ceftriaxona. A tres aislamientos resistentes a ciprofloxacina se les realizó electroforesis de campo pulsado. Se destacaron tres situaciones epidemiológicas de interés: en el año 1997, alta incidencia de aislamientos con resistencia plasmídica a tetraciclina (33,3%); en el período 2002-2004, un aumento significativo de la resistencia plasmídica a penicilina (9,7% a 34,8%); y en el año 2000, la emergencia de dos de los tres primeros aislamientos con resistencia a quinolonas del país. El primer aislamiento resistente a azitromicina en nuestro hospital emerge en el 2004. Este trabajo jerarquiza el rol del Laboratorio de Microbiología Clínica en la orientación del tratamiento empírico de la gonorrea. Resumen en inglés Resistance phenotypes characterized by minimum inhibitory concentration, disk diffusion and β-lactamase production were determined in 434 isolates from patients attending the Sexually Transmitted Disease Service at Dr. José María Cullen Hospital in Santa Fe, Argentina. Susceptibility tests to penicillin, tetracycline, ciprofloxacin, espectinomycin, azithromycin and ceftriaxone were performed. Pulsed-field gel electrophoresis was conducted made to on three ciproflox (mas) acin-resistant isolates. Epidemiologically speaking, three interesting events should be highlighted: during 1997, plasmid-mediated high level tetracycline-resistant strains were observed (33.3%); from 2002 to 2004 a significant increase of plasmid-mediated penicillin-resistant strains was registered (9.7% to 34.8%); and in the year 2000 the first two quinolone-resistant strains emerged in the province. In our hospital, the first azithromycin-resistant isolate emerged in 2004. We therefore emphasize the importance of the Clinical Microbiology Laboratory in order to provide information for the empiric treatment of this infection.

Scientific Electronic Library Online (Spanish)

99

Vaccination with recombinant Boophilus annulatus Bm86 ortholog protein, Ba86, protects cattle against B. annulatus and B. microplus infestations

Canales García-Menocal, Mario; Almazán, Consuelo; Naranjo, María Victoria; Jongejan, Frans; Fuente García, José de la
2009-03-31

Digital.CSIC (Spain)

101

Ubiquity and diversity of multidrug resistance genes in Lactococcus lactis strains isolated between 1936 and 1995

Flórez García, Ana Belén; González de los Reyes-Gavilán, Clara; Wind, Anette; Mayo Pérez, Baltasar; Margolles Barros, Abelardo

The presence and the nucleotide sequence of four multidrug resistance genes, lmrA, lmrP, lmrC, and lmrD, were investigated in 13 strains of Lactococcus lactis ssp. lactis, four strains of Lactococcus lactis ssp. cremoris, two strains of Lactococcus plantarum, and two strains of Lactococcus raffinola...

DRIVER (Spanish)

102

Ubiquity and diversity of multidrug resistance genes in Lactococcus lactis strains isolated between 1936 and 1995

Flórez García, Ana Belén; González de los Reyes-Gavilán, Clara; Wind, Anette; Mayo Pérez, Baltasar; Margolles Barros, Abelardo
2006-08-21

Digital.CSIC (Spain)

104

Trends in Antimicrobial Resistance in 1,968 Invasive Streptococcus pneumoniae Strains Isolated in Spanish Hospitals (2001 to 2003): Decreasing Penicillin Resistance in Children's Isolates

Baquero, Fernando; Oteo, Jesús; de Abajo, Francisco J.; Lázaro, Edurne; Campos, José

To address the public health problem of antibiotic resistance, the European Union (EU) founded the European Antimicrobial Resistance Surveillance System. A network of 40 hospitals that serve approximately 30% of the Spanish population (about 12 million) participated. Each laboratory reported data on...

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105

Transformation of Escherichia coli with DNA from Saccharomyces cerevisiae cell lysates

Adam, Ana Cristina; González Blasco, Gracia; Rubio Texeira, Marta; Polaina Molina, Julio
1999-12-01

Digital.CSIC (Spain)

106

Thermus thermophilus Strains Active in Purine Nucleoside Syntesis

Almendros, Marcos; Sinisterra Gago, Jose-Vicente; Berenguer, José

Digital.CSIC (Spain)

108

The role of GAP1 gene in the nitrogen metabolism of Saccharomyces cerevisiae during wine fermentation

Chiva, Rosana; Baiges, Isabel; Mas, Albert; Guillamón, José Manuel
2009-03-16

Digital.CSIC (Spain)

109

The Pseudomonas aeruginosa pfpI gene plays an antimutator role and provides general stress protection

Rodriguez-Rojas, Alexandro; Blázquez, Jesús

Hypermutator Pseudomonas aeruginosa strains, characterized by an increased spontaneous-mutation rate, are found at high frequencies in chronic lung infections. Hypermutability is associated with the loss of antimutator genes related to DNA repair or damage avoidance systems. Only a few antimutator g...

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110

The F1F0-ATPase of Bifidobacterium animalis is involved in bile tolerance

Sánchez García, Borja; González de los Reyes-Gavilán, Clara; Margolles Barros, Abelardo
2006-06-08

Digital.CSIC (Spain)

111

Texture evolution with superplastic deformation of a AlCu4Mg/Si3N4/20p composite

Fernández, Ricardo; Mabuchi, M; Higashi, K; González-Doncel, Gaspar
2009-03-01

Digital.CSIC (Spain)

112

Susceptibility and resistance to ethanol in Saccharomyces strains isolated from wild and fermentative environments

Arroyo López, Francisco Noé; Salvadó, Z.; Tronchoni, Jordi; Guillamón, José Manuel; Barrio, Eladio; Querol, Amparo
2010-12-01

Digital.CSIC (Spain)

113

Surface phenotypic characteristics and virulence of Spanish isolates of Aeromonas salmonicida after passage through fish.

Nieto, T P; Fernández, A I; Rodríguez, L A; Pérez, M J

Eleven strains of Aeromonas salmonicida were passaged twice by intraperitoneal injection through rainbow trout and reisolated from the kidney of moribund fish. The surface characteristics and virulence of the strains changed following passage through fish. None of the in vitro tests used could effec...

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115

Study of the origin of bending induced by bimetallic effect on microcantilevers

Ramos Vega, Daniel; Mertens, Johann; Calleja, Montserrat; Tamayo, Javier
2007-09-05

Digital.CSIC (Spain)

116

Stress proteins on the yeast cell surface determine resistance to osmotin, a plant antifungal protein

Yun, Dae-Jin; Zhao, Yuan; Pardo, José M.; Narasimhan, Meena L.; Damsz, Barbara; Lee, Hyeseung; Abad, Laura R.

Copyright © by National Academy of Sciences. La versión original está disponible en http://www.pnas.org/ | Strains of the yeast Saccharomyces cerevisiae differ in their sensitivities to tobacco osmotin, an antifungal protein of the PR-5 family. However, cells sensitive to tobacco osmotin showed resi...

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117

Strains nodulating Lupinus albus on different continents belong to several new chromosomal and symbiotic lineages within Bradyrhizobium

Velázquez, E.; Valverde, A.; Rivas, R.; Gomis, V.; Peix, A.; Gantois, I.; Igual, J. M.; León-Barrios, M.; Willems, A.; Mateos, P. F.; Martínez-Molina, E.
2010-01-01

Digital.CSIC (Spain)

118

Strain-Induced Quenching of Optical Transitions in Capped Self-Assembled Quantum Dot Structures

Prieto, J. A.; Armelles Reig, Gaspar; Utzmeier, T.; Briones Fernández-Pola, Fernando; Ferrer, J. C.; Peiró, F.; Cornet, A.; Morante, J. R.
1998-02-02

Digital.CSIC (Spain)

119

Strain effects on the surface optical transitions of GaAs

Postigo, Pablo Aitor; Armelles Reig, Gaspar; Briones Fernández-Pola, Fernando
1998-10-15

Digital.CSIC (Spain)

120

Strain determination in MBE-grown InAs quantum wires on InP

Mazuelas, A.; González, Luisa; García, Jorge M.; González, Yolanda; Schuelli, T.; Priester, C.; Metzger, T. H.
2006-01-12

Digital.CSIC (Spain)

121

Strain and phonon shifts in GaAs1−xPx alloys

Armelles Reig, Gaspar; Sanjuan Álvarez, María Luisa; González, Luisa; González, Yolanda
1996-03-25

Digital.CSIC (Spain)

123

Staphylococcus aureus comunitario resistente a cloxacilina: Comunicación de los primeros cinco casos descritos en Chile/ Community acquired infections with methicillin resistant strains of Staphylococcus aureus: Report of five cases

Noriega, Luis Miguel; González, Patricia; Hormazábal, Juan Carlos; Pinto, Consuelo; Canals, Magdalena; Munita, José Manuel; Thompson, Luis; Marcotti, Alejandra; Pérez, Jorge; Ibáñez, Daniel; Araya, Pamela; Canals, Claudio; Vial, Pablo
2008-07-01

Resumen en inglés Community acquired infections with methicillin resistant strains of Staphylococcus aureus (MRSA) infections have a more aggresive clinical course and involve mostly skin and lungs. These infections appear as outbreaks among prisoners, spoñsmen, men having sex with men and military personnel. The higher aggressiveness of these strains is due to the production of several toxins, mainly Panton- Valentine leukocidine. The detection of the gene that codes for this toxin is a (mas) distinctive feature ofthese strains. We report five patients with community acquired MRSA infections. The clinicalpresentation was a skin infection in all. One patient had a pleuropneumonia in addition. Apart for resistance to beta-lactam antimicrobials, the strains were resistant to erythromycin and ciprofloxacin. Patients were treated with vancomycin, clotrimoxazole or intravenous clindamycin with a good evolution. An epidemiológical surveillance for community acquired MRSA strain infections should be started and measures to adequately treat infected patients and avoid dissemination should be implemented

Scientific Electronic Library Online (Spanish)

124

Stability of retained austenite in TRIP-assisted

Sherif, M.Y.; García Mateo, Carlos; Sourmail, T.; Bhadeshia, H. K. D. H.
2004-01-01

Digital.CSIC (Spain)

125

Spontaneous Lactobacillus delbrueckii phage-resistant mutants with acquired bile tolerance

Guglielmotti, Daniela; Briggiler Marcó, Mariángeles; Vinderola, Celso; González de los Reyes-Gavilán, Clara

Three commercial phage-sensitive strains of Lactobacillus delbrueckii (strains Ab1, YSD V and Ib3) and four spontaneous phage-resistant mutants (strains A7, A17, V2 and I39) isolated from them, all with a probiotic potential previously demonstrated were studied for their tolerance of bile salts (ox ...

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126

Spontaneous Lactobacillus delbrueckii phage-resistant mutants with acquired bile tolerance

Guglielmotti, Daniela; Briggiler Marcó, Mariángeles; Vinderola, Celso; González de los Reyes-Gavilán, Clara; Jorge Reinheimer, Jorge; Quiberoni, Andrea
2007-01-01

Digital.CSIC (Spain)

128

Short-term temporal variability of ammonium and urea uptake by Alexandrium Catenella (Dinophyta)in cultures

Jauzein, Cécile; Collos, Yves; Garcés, Esther; Vila, Magda; Masó, Mercedes
2008-03-14

Digital.CSIC (Spain)

129

Short communication: effect of exopolysaccharide isolated from “VIIlI" on the adhesion of probiotics and pathogens to intestinal mucus

Ruas-Madiedo, Patricia; Gueimonde Fernández, Miguel; González de los Reyes-Gavilán, Clara; Salminen, Seppo

The strong ropy character of the Scandinavian fermented milk viili is conferred by the exopolysaccharides (EPS) produced by lactococcal strains. These biopolymers can be responsible for some health benefits. We have assessed the influence of the EPS fraction isolated from commercial viili on the adh...

DRIVER (Spanish)

130

Serotipos y susceptibilidad antimicrobiana de Streptococcus agalactiae/ Serotypes and antimicrobial susceptibility of Streptococcus agalactiae

Martínez T, María Angélica; Ovalle S, Alfredo; Durán T, Claudia; Reid S, Iván; Urriola J, Gabriela; Garay G, Beatriz; Cifuentes D, Marcela
2004-05-01

Resumen en inglés Background : Streptococcus agalactiae or group B streptococcus, GBS, is the leading cause of neonatal and maternal infections and an opportunistic pathogen in adults with underlying disease. In the last decade, a dramatic increase in the resistance of this microorganism to erythromycin and clindamycin has been observed. Aim: To determine the serotype distribution and antimicrobial susceptibility of isolates of S agalactiae collected from infections and colonization and to (mas) assess the genetic mechanisms of macrolide and clindamycin resistance. Material and methods: A total of 100 GBS isolates were collected between 1998 and 2002, in Santiago, Chile. They were isolated from the amniotic fluid from patients with premature rupture of membranes (7 isolates), blood from neonatal sepsis (10 isolates), neonate colonizations (2 strains), skin and soft tissue infections (7 isolates), urinary tract infections (5 isolates), genital infections (3 isolates), articular fluid (one isolate), and 65 strains were recovered from vaginal colonization55. Results: Serotypes Ia, II and III were the predominant serotypes identified in our study, accounting for 90 (90%) of the strains. Five isolates belonged to serotypes Ib (5%) and two (2%) to serotype V respectively; no strains belonging to serotype IV were found. All strains were susceptible to penicillin G, ampicillin and cefotaxime, and four isolates (4%) were resistant to both erythromycin (MIC >64 µg/ml) and clindamycin (MIC >64 µg/ml). The strains had a constitutive macrolide-lincosamide-streptogramin (cMLSB) resistance phenotype and the erm(A) gene was present in the four isolates. Conclusions: Serotypes Ia, II and III were the predominant serotypes in this study. All strains were susceptible to penicillin G, ampicillin and cefotaxime, and four (4%) strains were resistant to both erythromycin and clindamycin. The cMLSB resistance phenotype, and the erm(A) gene was detected in resistant strains (Rev Méd Chile 2004; 132: 549-55)

Scientific Electronic Library Online (Spanish)

131

Seroprevalence and Genomic Divergence of Circulating Strains of Feline Immunodeficiency Virus among Felidae and Hyaenidae Species

Troyer, Jennifer L.; Pecon-Slattery, Jill; Roelke, Melody E.; Johnson, Warren; VandeWoude, Sue; Vazquez-Salat, Nuria

Feline immunodeficiency virus (FIV) infects numerous wild and domestic feline species and is closely related to human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV). Species-specific strains of FIV have been described for domestic cat (Felis catus), puma (Puma concolor), lion (...

DRIVER (Spanish)

132

Second generation" of TSAO compounds directed against HIV-1 TSAO-resistant strains

Lobaton, E.; Velazquez, S.; Perez-Perez, M. J.; Jimeno, M. Luisa; San-Felix, S.; De Clercq, E.; Balzarini, J.; Camarasa, M. J.
2001-01-01

Digital.CSIC (Spain)

133

Screening of Exopolysaccharide-Producing Lactobacillus and Bifidobacterium Strains Isolated from the Human Intestinal Microbiota

Ruas-Madiedo, Patricia; Moreno Muñoz, José Antonio; Salazar Garzo, Nuria; Delgado Palacio, Susana; Mayo Pérez, Baltasar

Using phenotypic approaches, we have detected that 17% of human intestinal Lactobacillus and Bifidobacterium strains could be exopolysaccharide (EPS) producers. However, PCR techniques showed that only 7% harbored genes related to the synthesis of heteropolysaccharides. This is the first work to scr...

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137

Rga2 IS a Rho2 GAP that regulates morphogenesis and cell integrity in Schizosaccharomyces pombe

Villar-Tajadura, María Antonia; Coll, Pedro M.; Santos, Beatriz; Pérez González, Pilar

15 pages, 8 figures.-- PMID: 18793338 [PubMed].-- Supporting information (Table S1: List of strains used in the study) available at: http://www3.interscience.wiley.com/journal/121408738/suppinfo | Schizosaccharomyces pombe Rho2 GTPase regulates alpha-D-glucan synthesis and acts upstream of Pck2 to a...

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138

Resistencia a metronidazol y claritromicina en aislamientos de Helicobacter pylori de pacientes dispépticos en Colombia/ Antimicrobial susceptibility of Helicobacter pylori strains isolated in Colombia

Álvarez, Adalucy; Moncayo, José Ignacio; Santacruz, Jorge Javier; Corredor, Luisa Fernanda; Reinosa, Elizabeth; Martínez, José William; Beltrán, Leonardo
2009-10-01

Resumen en inglés Background: Helicobacter pylori antimicrobial resistance rates differ among countries and even between different areas of a country. In Colombia, the most commonly used antimicrobials for the treatment of H pylori infection are amoxicillin, clarithromycin and metronidazole. Aim: To determine antimicrobial susceptibility of H pylori strains isolated in Colombia. Materials and methods: Eighty eight strains of H pylori were isolated and identified by microbiological methods (mas) and confirmed with polymerase chain reaction (PCR). The detection of antimicrobial resistance to amoxicillin, clarithromycin, metronidazole and tetraclycline, was conducted by the Etest method. Mutations in the 23S rDNA, involved in resistance to clarithromycin, were detected using PCR and restriction fragment lenght polymorphism. Results: Eighty eight and 2.2% of the strains were resistant to metronidazole and clarithromycin, respectively. No isolate was simultaneously resistant to amoxicillin or tetracycline. The two clarithromycin resistant strains were homozygous for the A2143G mutation. No mutations were found in the remaining 86 susceptible strains. Conclusions: The high rate of metronidazole resistance in our population precludes the use of this drug for the empirical treatment of Hpylori infection

Scientific Electronic Library Online (Spanish)

140

Reduction of oxidative cellular damage by overexpression of the thioredoxin TRX2 gene improves yield and quality of wine yeast dry active biomass

Gómez Pastor, Rocío; Pérez Torrado, Roberto; Cabiscol, Elisa; Ros, Joaquim; Matallana, Emilia
2010-02-12

Digital.CSIC (Spain)

141

Recombinant wine yeasts

González García, Ramón; González Ramos, Daniel
2010-03-09

Digital.CSIC (Spain)

142

Raman-assisted distributed Brillouin sensor in optical fiber for strain and temperature monitoring in civil engineering applications

Rodríguez Barrios, Félix; Martín-Lopez, Sonia; Carrasco-Sanz, Ana; Corredera, Pedro; Hernanz, Maria Luisa; González-Herraez, Miguel
2009-01-01

Digital.CSIC (Spain)

143

Quality Control for β-Lactam Susceptibility Testing with a Well-Defined Collection of Enterobacteriaceae and Pseudomonas aeruginosa Strains in Spain

Baquero, Fernando; Cantón, Rafael; Del Carmen Conejo, María; Loza, Elena; Martínez-Martínez, Luis

Eighteen Enterobacteriaceae and Pseudomonas aeruginosa strains, 16 of them with well-defined β-lactam re sistance mechanisms, were sent to 52 Spanish microbiology laboratories. Interpretative categories for 8 extended-spectrum β-lactams were collected. Participating laboratories used their own routi...

DRIVER (Spanish)

144

PseudoMLSA: a database for multigenic sequence analysis of Pseudomonas species

Bennasar, Antoni; Mulet, Magdalena; Lalucat, Jorge; García-Valdés, Elena
2010-04-21

Digital.CSIC (Spain)

146
147

Process for obtaining specific probes of strain or specie

Pérez Martínez, Gaspar; Miralles, María del Carmen
1996-08-15

Digital.CSIC (Spain)

148

Prevención de la neumonía del adulto adquirida en la comunidad/ Prevention of community-acquired pneumonia in adults

Barros M, Manuel; Cartagena S, Claudia; Bavestrello F, Luis
2005-01-01

Resumen en inglés Polysaccharide 23 valent pneumococcal vaccine commercially available from 1983 includes 23 serotypes of Streptococcus pneumoniae, representing near 90% of strains involved in invasive pneumococcal disease in immune competent adults. Vaccine confers protection against invasive pneumococcal disease. Immunization is recommended in adults over 65 years old, in patients affected by chronic diseases (cardiopathies, COPD, nephropathies, diabetes mellitus, hepatic cirrhosis, chro (mas) nic breakage in brain-blood barrier, functional or anatomical asplenia, alcoholism), in immunocompromised hosts, including HIV infection, chemotherapy treatment and hematological malignancies. Influenza vaccine is prepared with particulated antigens, including two influenza A strains and one influenza B strain, selected according to influenza epidemiological worldwide surveillance the year before. On account of continuous antigenic changes (drifts), it is necessary to modify the vaccine antigen's composition yearly. Cost/effectiveness evaluation has confirmed the efficacy of influenza vaccine in reducing morbidity and mortality associated to influenza epidemic and health economical resources involved in patient care. Besides, clinical trials have confirmed that immunization reduces the risk of acquiring pneumonia, of hospitalization and death in elderly people during the influenza epidemic, when vaccine antigenic composition is similar to the circulating strains. Vaccination is recommended annually in healthy adults over 65 years old, in patients with chronic diseases (cardiopathies, COPD, nephropathies, diabetes mellitus, hepatic cirrhosis, chronic breakage of blood-brain barrier, functional or anatomical asplenia, alcoholism). It is also recommended in women who will be in the second or third trimester of pregnancy during the influenza season, in immunocompromised hosts, in institutionalized patients (geriatrics), health care workers, and travelers to geographical areas that are affected by the influenza epidemic

Scientific Electronic Library Online (Spanish)

149

Prevalence of Clinical Isolates of Escherichia coli Producing Inhibitor-Resistant β-Lactamases at a University Hospital in Barcelona, Spain, over a 3-Year Period

Sabaté, Montserrat; Miró, Elisenda; Mirelis, Beatriz; Navarro, Ferran; Rivera, Alba; Coll, Pere; Prats, Guillem

About 7% of 7,252 nonduplicated clinical Escherichia coli strains from a Spanish hospital showed reduced susceptibility to amoxicillin-clavulanate. Of these, 0.37% produced the IRTs TEM-30, TEM-31, TEM-33, TEM-34, TEM-37, TEM-40, TEM-51, and TEM-54; 5.3% were probable class C β-lactamase overproduce...

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150

Prevalence and Evolution of Methicillin-Resistant Staphylococcus aureus in Spanish Hospitals between 1996 and 2002

Cabrera, R.; Vindel, A.; Gómez, E.; Trincado, P.; Boquete, T.; Saez-Nieto, J. A.; Solá, C.; Valdezate, S.

Pulsed-field gel electrophoretic analysis of 2,144 methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from patients in Spanish hospitals over a 7-year period revealed 17 predominant profiles. Typing showed the replacement of Iberian clone E1 (ST247-MRSA-I) by two prevalent clones, E...

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151

Presencia de metalo-ß-lactamasas en Pseudomonas aeruginosa resistente a imipenem/ Presence of metal lo ß-lactamases in imipenem-resistant Pseudomonas aeruginosa

Pérez I, Alfonso; García C, Patricia; Poggi M, Helena; Braun J, Stephanie; Castillo V, Claudia; Román, Juan Carlos; Lagos, Marcela; Romeo 0, Eliana; Porte T, Lorena; Labarca L, Jaime; González R, Gerardo
2008-04-01

Resumen en inglés Background: Metallo-ß-lactamases (MBL) confer high resistance to carbapenems in Pseudomonas aeruginosa (Psae). They are encoded in mobile elements of different genes (VIM, IMP, SMP, GIM), along with other resistance genes. Aim: To detect the presence of MBL in imipenem resistant Psae strains. Material and methods: Fifty-nine imipenem resistant Psae strains isolated from January 2004 to August 2005 in a University Clinical Hospital, were included. The presence of MBL was (mas) studied by Etest (phenotypic) and genotypic polymerase chain reaction (PCR) methods. To rule out a nosocomial outbreak, MBL positive strains, were studied by pulse field gel electrophoresis. Results: The presente of MBL was detected in eleven strains. AH were type VIM and were not clonally related. There was no concordance between phenotypic and genotypic MBL detecting methods. AH the strains were also multiresistant. Conclusions: The presence of MBL was detected in 19% of imipenem resistant Psae strains

Scientific Electronic Library Online (Spanish)

152

Population dynamics of swine influenza virus in finishing pigs

Loeffen, W.L.A.

Influenza virus infections in swine were first noticed in the US in 1918, during the human pandemic of the Spanish flu. In Europe, seroprevalences for the three most common swine influenza strains at the moment, H1N1, H3N2 and H1N2, range from 20-80% in finishing pigs at the end of the finishing per...

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153

Population Genetics of Vibrio vulnificus: Identification of Two Divisions and a Distinct Eel-Pathogenic Clone

Gutacker, Michaela; Conza, Nadine; Benagli, Cinzia; Pedroli, Ambra; Bernasconi, Marco Valerio; Permin, Lise

Genetic relationships among 62 Vibrio vulnificus strains of different geographical and host origins were analyzed by multilocus enzyme electrophoresis (MLEE), random amplification of polymorphic DNA (RAPD), and sequence analyses of the recA and glnA genes. Out of 15 genetic loci analyzed by MLEE, 11...

DRIVER (Spanish)

155

Polymorphism of Listeria monocytogenes and Listeria innocua strains isolated from short-ripened cheeses

Margolles, Abelardo; Mayo Pérez, Baltasar; González de los Reyes-Gavilán, Clara

Thirty isolates of Listeria monocytogenes and 18 of L. innocua obtained from different short-ripened cheeses manufactured in Asturias (northern Spain), were compared with each other and with reference strains using serotype, phage type and pulsed-field restriction endonuclease digestion profiles ana...

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156

Polyclonal B-cell activation by a synthetic analogue of bacterial lipoprotein is functionally different from activation by bacterial lipopolysaccharide.

Martínez-Alonso, Carlos; Kleine, B.; Sprenger, R.; Bessler, W. G

The reactivity of 38 murine strains to a synthetic analogue of bacterial lipoprotein, tripalmitoyl-pentapeptide (TPP), was tested and compared with the reactivity to lipopolysaccharide (LPS). These strains include common laboratory mice and H-2 recombinant inbred lines, as well as some newly bred li...

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159

Phonon pressure coefficient as a probe of the strain status of self-assembled quantum dots

Reparaz, J. S.; Bernardi, A.; Goñi, A. R.; Lacharmoise, P. D.; Alonso, M. I.; Garriga, M.; Novák, J.; Vávra, I.
2007-08-01

Digital.CSIC (Spain)

160

Phaseolus lunatus is nodulated by a phosphate solubilizing strain of Sinorhizobium meliloti in a Peruvian soil.

Ormeño, E.; Torres, R.; Mayo, J.; Rivas, R.; Peix, A.; Velázquez, E.; Zuñiga, D.
2007-01-01

Digital.CSIC (Spain)

162

Optical phonon behavior in strain-free dilute Ga(As,N) studied by Raman scattering

Ibáñez, Jordi; Alarcón-Lladó, Esther; Cuscó, Ramón; Artús, Lluís; Hopkinson, Mark
2007-07-03

Digital.CSIC (Spain)

163

Observation of dislocation generation in highly strained quantum well lasers during operation

Mazuelas, A.; Dotor, María Luisa; Golmayo, Dolores; Zeimer, U.; Baumbach, T.; Luebbert, D.; Grenzer, J.; Baruchel, J.
2001-05-21

Digital.CSIC (Spain)

164

Novel strain of lactobacillus plantarum for the production of carotenoids

Ruiz Barba, Jose Luis; Garrido Fernández, Juan; Hornero Méndez, Dámaso; Maldonado-Barragán, Antonio; Caballero-Guerrero, Belén
2010-12-16

Digital.CSIC (Spain)

166

Natural diversity of nodular microsymbionts of Alnus glutinosa in the Tormes River basin.

Igual, J. M.; Valverde, A.; Velázquez, E.; Santa Regina, I.; Rodríguez-Barrueco, C.
2006-01-01

Digital.CSIC (Spain)

167

Mutational Patterns Associated with the 69 Insertion Complex in Multi-drug-resistant HIV-1 Reverse Transcriptase that Confer Increased Excision Activity and High-level Resistance to Zidovudine

Cases-González, Clara E.; Franco, Sandra; Martínez, Miguel Angel; Menéndez-Arias, Luis

Article available at http://dx.doi.org/10.1016/j.jmb.2006.09.073 | Human immunodeficiency virus type 1 (HIV-1) strains having dipeptide insertions in the fingers subdomain and other drug resistance-related mutations scattered throughout their reverse transcriptase (RT)-coding region show high-level ...

DRIVER (Spanish)

169

Mucin Degradation by Bifidobacterium Strains Isolated from the Human Intestinal Microbiota

Ruas-Madiedo, Patricia; Gueimonde Fernández, Miguel; Fernández García, María; González de los Reyes-Gavilán, Clara

The presence of the genes engBF (endo--N-acetylgalactosaminidase) and afcA (1,2--L-fucosidase) was detected in several intestinal Bifidobacterium isolates. Two strains of Bifidobacterium bifidum contained both genes, and they were able to degrade high-molecular weight porcine mucin in vitro. The exp...

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173

Molecular characterization of intrinsic and acquired antibiotic resistance in lactic acid bacteria and bifidobacteria

Ammor, Mohammed Salim; Flórez García, Ana Belén; H.A.M. van Hoek, Angela; González de los Reyes-Gavilán, Clara

The minimum inhibitory concentrations (MICs) of 6 different antibiotics (chloramphenicol, clindamycin, erythromycin, streptomycin, tetracycline and vancomycin) were determined for 143 strains of lactic acid bacteria and bifidobacteria using the Etest. Different MICs were found for different species ...

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174

Molecular characterization of intrinsic and acquired antibiotic resistance in lactic acid bacteria and bifidobacteria

Ammor, Mohammed Salim; Flórez García, Ana Belén; H. A. M. van Hoek, Angela; González de los Reyes-Gavilán, Clara; J.M. Aarts, Henk; Margolles Barros, Abelardo; Mayo Pérez, Baltasar
2008-01-01

Digital.CSIC (Spain)

175

Molecular characterization of Anaplasma platys strains from dogs in Sicily, Italy

Fuente García, José de la; Torina, Alessandra; Naranjo, Victoria; Nicosia, Silviane; Alongi, Angelina

[Background] The genetic diversity of Anaplasma platys (Rickettsiales: Anaplasmataceae) strains is currently poorly defined. The present study was designed to characterize A. patys strains in dogs from Palermo, Sicily, Italy, using a combination of PCR and sequence analysis of the 16S rDNA, heat sho...

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176

Molecular characterization of Anaplasma platys strains from dogs in Sicily, Italy

Fuente García, José de la; Torina, Alessandra; Naranjo, María Victoria; Nicosia, Silviane; Alongi, Angelina; La Mantia, Francesco; Kocan, Katherine M.
2006-07-26

Digital.CSIC (Spain)

177

Molecular Typing by Pulsed-Field Gel Electrophoresis of Spanish Animal and Human Listeria monocytogenes Isolates

Franco, C.; Rodriguez Moure, A. A.; Dominguez, L.; Blanco, M. M.; Moreno, M. A.; Latre, M. V.; Vela, A. I.; Fernandez-Garayzabal, J. F.

A total of 153 strains of Listeria monocytogenes isolated from different sources (72 from sheep, 12 from cattle, 18 from feedstuffs, and 51 from humans) in Spain from 1989 to 2000 were characterized by pulsed-field gel electrophoresis. The strains of L. monocytogenes displayed 55 pulsotypes. The 84 ...

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178

Molecular Characterization of a Chromosomal Rearrangement Involved in the Adaptive Evolution of Yeast Strains

Pérez Ortín, José E; Querol, Amparo; Puig, Sergi; Barrio, Eladio

Wine yeast strains show a high level of chromosome length polymorphism. This polymorphism is mainly generated by illegitimate recombination mediated by Ty transposons or subtelomeric repeated sequences. We have found, however, that the SSU1-R allele, which confers sulfite resistance to yeast cells, ...

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179

Mitotic recombination and genetic changes in Saccharomyces cerevisiae during wine fermentation

Puig, Sergi; Querol, Amparo; Barrio, Eladio; Pérez Ortín, José E

Natural strains of Saccharomyces cerevisiae are prototrophic homothallic yeasts that sporulate poorly, are often heterozygous, and may be aneuploid. This genomic constitution may confer selective advantages in some environments. Different mechanisms of recombination, such as meiosis or mitotic rearr...

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180

Microfabricated photoplastic cantilever with integrated photoplastic/carbon based piezoresistive strain sensor

Gammelgaard, L.; Rasmussen, P. A.; Calleja, Montserrat; Vettiger, P.; Boisen, Anja
2006-03-15

Digital.CSIC (Spain)

181

Large Conjugative Plasmids from Clinical Strains of Salmonella enterica Serovar Virchow Contain a Class 2 Integron in Addition to Class 1 Integrons and Several Non-Integron-Associated Drug Resistance Determinants

Rodríguez, Irene; Rodicio, M. Rosario; Mendoza, M. Carmen; Martín, M. Cruz

Final full-text version of the paper available at: http://dx.doi.org/10.1128/AAC.50.4.1603-1607.2006. | Two large conjugative resistance (R) plasmids from clinical strains of Salmonella enterica serovar Virchow carried a class 2 integron with the 5' conserved sequence (5'CS)-dfrA1-sat1-aadA1-3'CS ge...

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184

Isolation, properties and behaviour of tyramine-producing lactic acid bacteria from wine

Moreno-Arribas, M. V.; Torlois, S.; Joyeux, A.; Bertrand, A.; Lonvaud-Funel, A.

Wines containing high levels of biogenic amines were investigated for the presence of tyramine-producing strains. Two different Lactobacillus brevis (IOEB 9809 and IOEB 9901) able to produce the amine were isolated. None of the isolated strains identified as Oenococcus oeni formed tyramine. In addit...

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185

Isolation, properties and behaviour of tyramine-producing lactic acid bacteria from wine

Moreno-Arribas, M. V.; Torlois, S.; Joyeux, A.; Bertrand, A.; Lonvaud-Funel, A.
2000-01-01

Digital.CSIC (Spain)

188

Isolation and Characterization of Temperate and Virulent Bacteriophages of Lactobacillus plantarum

Caso, J. L.; González de los Reyes-Gavilán, Clara; Herrero, Monica; Montilla, Antonia; Rodríguez González, Ana

DRIVER (Spanish)

191

Influence of the yeast strain on the changes of the amino acids, peptides and proteins during sparkling wine production by the traditional method

Martinez-Rodriguez, A. J.; Carrascosa, Alfonso V.; Martin-Alvarez, Pedro J.; Moreno-Arribas, M. V.; Polo, M. C.

The influence of five yeast strains on the nitrogen fractions, amino acids, peptides and proteins, during 12 months of aging of sparkling wines produced by the traditional or Champenoise method, was studied. High-performance liquid chromatography (HPLC) techniques were used for analysis of the amino...

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192

Influence of a defined-strain starter and Lactobacillus plantarum as adjunct culture on volatile compounds and sensory characteristics of Manchego cheese

Gómez-Ruiz, José Ángel; Cabezas, Lourdes; Martínez-Castro, Isabel; González-Viñas, Miguel Ángel; Poveda, Justa María
2008-05-01

Digital.CSIC (Spain)

193

Induction of α-L-arabinofuranosidase activity by monomeric carbohydrates in Bifidobacterium longum and ubiquity of encoding genes

Gueimonde Fernández, Miguel; Noriega Pérez, Luis; Margolles Barros, Abelardo; González de los Reyes-Gavilán, Clara

Bifidobacterium longum can be isolated from human faeces, some strains being considered probiotics. B. longum NIZO B667 produces an exo-acting α-L-arabinofuranosidase, AbfB, previously purified by us, that releases L-arabinose from arabinan and arabinoxylan. This activity was subjected to two-seven-...

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194

In Vitro Susceptibilities of 400 Spanish Isolates of Neisseria gonorrhoeae to Gemifloxacin and 11 Other Antimicrobial Agents

de la Fuente, L.; Berrón, S.; Giménez, M. J.; Vázquez, J. A.; Aguilar, L.

The in vitro activity of gemifloxacin versus those of 11 other antimicrobial agents against 400 strains of Neisseria gonorrhoeae was determined by microdilution with supplemented GC agar. A total of 37.5% of the strains were β-lactamase positive. A total of 70 and 6.4% of the β-lactamase-negative st...

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195

In Vitro Activities of Tigecycline (GAR-936) against Recently Isolated Clinical Bacteria in Spain

Gómez, María; Betriu, Carmen; Sánchez, Blas Ali; Rodríguez-Avial, Iciar; Álvarez, Juan; Picazo, Juan J.

The antimicrobial activities of tigecycline (GAR-936) were compared with those of other agents against 1,087 strains recently isolated in 12 Spanish medical centers. Tigecycline showed activity against a wide spectrum of aerobic and anaerobic bacteria, including strains such as methicillin-resistant...

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196

Improvement of SCP production and BOD removal of whey with mixed yeast culture

Moeini, Hassan; Nahvi, Iraj; Tavassoli, Manoochehr
2004-12-01

Resumen en inglés This research emphasizes on single cell protein (SCP) production and Biochemical Oxygen Demand (BOD) removal from whey with mixed yeast culture. For this purpose, 11 yeast strains were isolated from dairy products (M1-M11) and the strains were identified by morphological and physiological properties. These yeast strains were tested for their ability to reduce the BOD and to produce SCP from whey. Among these strains, K. lactis (M2) had the most SCP production from whey wi (mas) th the yield of 11.79 g/l. Ammonium sulphate as nitrogen source had an increasing effect on biomass yield. The mixed culture of the isolated yeast strains with Saccharomyces cerevisiae was used in order to increase the biomass yield and BOD removal. The highest biomass yield (22.38 g/l) and reduction of initial BOD from 30000 to 3450 mg/l were obtained with the mixed culture of K. lactis (M2) and S. cerevisiae

Scientific Electronic Library Online (Spanish)

197

Identification of an Emergent and Atypical Pseudomonas viridiflava Lineage Causing Bacteriosis in Plants of Agronomic Importance in a Spanish Region

González, Ana J.; Mendoza, M. Carmen; Rodicio, M. Rosario

Pseudomonas strains with an atypical LOPAT profile (where LOPAT is a series of determinative tests: L, levan production; O, oxidase production; P, pectinolitic activity; A, arginine dihydrolase production; and T, tobacco hypersensibility) can be regarded as emergent pathogens in the Principality of ...

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199

Hydrogen in alpha-iron: stress and diffusion

Sánchez, Javier; Fullea, José; Andrade, Carmen; Andrés, Pedro L. de

First-principles density-functional theory has been used to investigate equilibrium geometries, total energies, and diffusion barrfiers for H as an interstitial impurity absorbed in bcc-Fe. Internal strains/stresses upon hydrogen absorption are a crucial factor to understand preferred absorption sit...

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200

Heterologous expression of enterocin AS-48 in several strains of lactic acid bacteria

Fernández, M.; Martínez-Bueno, M.; Martín Martín, M.Cruz; Valdivia, E.; Maqueda, M.

Final full-text version of the paper available at: http://dx.doi.org/10.1111/j.1365-2672.2006.03194.x. | [Aims] Enterococcus faecalis produces a cationic and circular enterocin, AS-48, of 7149 Da, the genetic determinants of which are located within the pMB2 plasmid. We have compared enterocin AS-48...

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202

Head-to-head comparison on the immunogenicity of two HIV/AIDS vaccine candidates based on the attenuated poxvirus strains MVA and NYVAC co-expressing in a single locus the HIV-1(BX08) gp120 and HIV-1(IIIB) Gag-Pol-Nef proteins of clade B

Gómez, Carmen E.; Nájera, José L.; Pérez Jiménez, Eva; Jiménez, Victoria; Wagner, Ralf; Graf, Marcus

23 pages, 8 figures.-- PMID: 17113200 [PubMed].-- Includes Appendix A: DNA sequence of MVA-B in the TK viral locus.-- Printed version published on Apr 12, 2007. | In this investigation we have generated and defined the immunogenicity of two novel HIV/AIDS vaccine candidates based on the highly atten...

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203

Growth and metabolic activity of a cheese starter in CO2-acidified and non-acidified refrigerated milk

Rúas Madiedo, Patricia; Alonso López, Leocadio; González de Llano, M.ª Dolores; González de los Reyes-Gavilán, Clara

The growth and activity of two Lactococcus strains and one Leuconostoc strain in CO2-acidified and non-acidified refrigerated milk were evaluated separately and as a mixed culture to determine their suitability for use as a starter in the manufacture of Afuega’l Pitu, an acid-coagulated Spanish chee...

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204

Growth and metabolic activity of a cheese starter in CO2-acidified and non-acidified refrigerated milk

Ruas-Madiedo, Patricia; Alonso López, Leocadio; González de Llano, M.ª Dolores; González de los Reyes-Gavilán, Clara
1998-03-23

Digital.CSIC (Spain)

205

Genotipos de Staphylococcus aureus con fenotipo meticilino resistente, aislados de pacientes del Hospital Base de Valdivia/ Genotypes of Staphylococcus aureus strains with methicillin resistant phenotype

Wilson S, Myra; Otth L, Carola; Medina S, Gustavo; Otth R, Laura; Fernández J, Heriberto; Arce, María; Zaror C, Angela; Lizama, Víctor; Gil D, Mónica; von Chrismar, Ana María
2007-05-01

Resumen en inglés Background: Methicillin resistant strains of Staphylococcus aureus (MRSA) are an important cause of nosocomial infections. Aim: To determine the genotypes of MRSA strains. Material and methods: Fifty five strains of MRSA, isolated from patients hospitalized in Hospital Base Valdivia, were studied. The phenotype was determined through MicroScan® in all strains and by minimum inhibitory concentration (MIC) in 41. The genotype of the strains was analyzed by a duplex polymer (mas) ase chain reaction (PCR) of the mecA gene, amplifying eight hypervariable DNA regions associated to such gene. Results: According to MIC, 88% of strains had a pattern of resistance against multiple antimicrobial (penicillin, ampicillin, cephradine, gentamycin, ciprofloxacin, ¡incomycin and erythromycin). Vancomicin resistan strains were not detected. Only 53 strains (96%) had at least one of the eight hypervariable regions and were classified as MRSA. Genotypic patterns types 15 were the most commonly detected in 38% and 34% of strains, respectively. MicroScan® erroneously classified five strains in an incorrect phenotype, according to results obtained with duplex PCR. MIC results did not differ from those of duplex PCR. Conclusions: Duplex- PCR is a useful tool to detect hyper variable regions associated to mecA gene

Scientific Electronic Library Online (Spanish)

206

Genetically engineered Pseudomonas: a factory of new bioplastics with broad applications

Olivera, Elías R.; Carnicero, David; Jodra, Ruth; Miñambres Rodríguez, Baltasar; García, Belén; Abraham, Gustavo A.

7 pages, 4 figures, 1 table.-- PMID: 11722541 [PubMed]. | New bioplastics containing aromatic or mixtures of aliphatic and aromatic monomers have been obtained using genetically engineered strains of Pseudomonas putida. The mutation (-) or deletion (Delta) of some of the genes involved in the beta-o...

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207

Genetic procedures for identification of enterotoxigenic strains of Staphylococcus aureus from three food poisoning outbreaks

Martín, M. Cruz; Fueyo Mendoza, José María; González-Hevia, M. A.; Mendoza, M. Carmen

Final full-text version of the paper available at: http://dx.doi.org/10.1016/j.ijfoodmicro.2004.01.011. | Three food poisoning restaurant outbreaks due to Staphylococcus aureus, occurring during June–October 2002 in the Principality of Asturias (PA), Spain, provided the basis for investigating some ...

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208

Genetic procedures for identification of enterotoxigenic strains of Staphylococcus aureus from three food poisoning outbreaks

Martín, M. Cruz; Fueyo Mendoza, José María; González-Hevia, M. A.; Mendoza, M. Carmen
2004-08-01

Digital.CSIC (Spain)

209

Genetic Heterogeneity of Clinical Strains of Yersinia enterocolitica Traced by Ribotyping and Relationships between Ribotypes, Serotypes, and Biotypes

Mendoza, M. C.; Lobato, M. J.; González-Hevia, M. A.; Landeras, E.

A series of 74 Yersinia enterocolitica clinical strains collected in a Spanish region and 10 reference strains, assigned to nine serotypes and five biotypes, were analyzed by ribotyping procedures. Riboprobing, performed separately with HindIII and BglI and using an rrn operon as the probe, generate...

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210

Generation of Food-Grade Recombinant Lactic Acid Bacterium Strains by Site-Specific Recombination

Martín, M. Cruz; Alonso, Juan C.; Suárez Fernández, Juan Evaristo; Álvarez González, Miguel Ángel

Final full-text version of the paper available at: http://aem.asm.org/cgi/content/abstract/66/6/2599. | The construction of a delivery and clearing system for the generation of food-grade recombinant lactic acid bacterium strains, based on the use of an integrase (Int) and a resolvo-invertase (β-rec...

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211

Generation of Food-Grade Recombinant Lactic Acid Bacterium Strains by Site-Specific Recombination

Martín, M. Cruz; Alonso, Juan C.; Suárez Fernández, Juan Evaristo; Álvarez González, Miguel Ángel
2000-06-01

Digital.CSIC (Spain)

212

Gene expression analysis of cold and freeze stress in baker's yeast

Rodríguez Vargas, Sonia; Estruch, Francisco; Rández Gil, Francisca
2002-06-01

Digital.CSIC (Spain)

213

Fungal Degradation of Lipophilic Extractives in Eucalyptus globulus Wood

Gutiérrez, Ana; Río Andrade, José Carlos del; Martínez Hernández, María Jesús; Martínez Ferrer, Ángel Tomás

Solid-state fermentation of eucalypt wood with several fungal strains was investigated as a possible biological pretreatment for decreasing the content of compounds responsible for pitch deposition during Cl2-free manufacture of paper pulp. First, different pitch deposits were characterized by gas c...

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215

Fluorescence spectroscopy: a rapid tool for assessing tetracycline resistance in Bifidobacterium longum

Ammor, Mohammed Salim; Flórez García, Ana Belén; Margolles Barros, Abelardo; Mayo Pérez, Baltasar

[EN]The tetracycline uptake kinetics of 35 Bifidobacterium longum strains isolated from the human gastrointestinal tract were examined by fluorescence spectroscopy, and the suitability of the technique as a screening tool of tetracycline resistance or susceptibility was determined. The strains were ...

DRIVER (Spanish)

216

Exopolysaccharides produced by probiotic strains modify the adhesion of probiotics and enteropathogens to human intestinal mucus

Ruas-Madiedo, Patricia; Gueimonde Fernández, Miguel; Margolles Barros, Abelardo; González de los Reyes-Gavilán, Clara

Exopolysaccharides (EPSs) are exocellular polymers present in the surface of many bacteria, including Lactobacillus and Bifidobacterium. The genome sequence of several strains revealed the presence of EPS-encoding genes. However, the physiological role that EPSs play in the bacterial ecology still r...

DRIVER (Spanish)

217

Existence of a True Phosphofructokinase in Bacillus sphaericus: Cloning and Sequencing of the pfk Gene

Alice, Alejandro F; Pérez Martínez, Gaspar; Sánchez Rivas, Carmen

Some strains of Bacillus sphaericus are entomopathogenic to mosquito larvae, which transmit diseases, such as filariasis and malaria, affecting millions of people worldwide. This species is unable to use hexoses and pentoses as unique carbon sources, which was proposed to be due to the lack of glyco...

DRIVER (Spanish)

218

Evaluation of biological control agents for managing cucurbit powdery mildew on greenhouse-grown melon

Torés Montosa, Juan Antonio

An evaluation was made of the ability of two mycoparasite-based products AQ10® (Ampelomyces quisqualis) and Mycotal® (Lecanicillium lecanii), as well as three strains of Bacillus subtilis, to manage powdery mildew disease, caused by Podosphaera fusca on melon seedlings maintained under different reg...

DRIVER (Spanish)

219

Entorno genético de CTX-M-2 en aislamientos de Klebsiella pneumoniae provenientes de pacientes hospitalizados en Uruguay | Genetic environment of CTX-M-2 in Klebsiella pneumoniae isolates from hospitalized patients in Uruguay

Vignoli, R.; Cordeiro, N.; Seija, V.; Schelotto, F.; Radice, M.; Ayala, Juan Alfonso; Power, P.; Gutkind, Gabriel

Klebsiella pneumoniae clinical strains, K96005 and K13, isolated from hospitalized patients in Uruguay, during 1996 and 2003, respectively. The genomic surroundings of blaCTX-M-2 were characterized by PCR-mapping and DNA sequencing. Our results show that blaCTX-M-2 is included in a complex class-1 i...

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220

Enterotoxigenicity of Staphylococcus strains isolated from Spanish dry-cured hams.

Marín, M E; Cornejo, I; de la Rosa, M C

The ability of 135 Staphylococcus strains isolated from Spanish dry-cured hams to produce enterotoxins in culture was investigated by the reversed passive latex agglutination method. A high percentage of enterotoxigenic Staphylococcus aureus strains (85.9%) was recorded, and 54.3% of these produced ...

DRIVER (Spanish)

222

Effect of inoculation with a strain of Pseudomonas fragi in the growth and phosphorous content of strawberry plants.

Martín, L.; Velázquez, E.; Rivas, R.; Mateos, P. F.; Martínez-Molina, E.; Rodríguez-Barrueco, C.; Peix, A.
2007-01-01

Digital.CSIC (Spain)

224

Effect of Plastic Deformation on the Microscopic Residual Stresses in 6061Al-15vol%SiCw Composites

Fernández, Ricardo; Bruno, G; Peng, R. L; González-Doncel, Gaspar
2003-08-15

Digital.CSIC (Spain)

225

Dictyostelium transcriptional responses to Pseudomonas aeruginosa: common and specific effects from PAO1 and PA14 strains

Carilla Latorre, Sergio; Calvo Garrido, Javier; Bloomfield, Gareth; Skelton, Jason; Kay, Robert R.; Ivens, Alasdair

15 pages.-- Final full-text version of the paper also available at: http://dx.doi.org/10.1186/1471-2180-8-109.-- Includes 3 additional files: Dictyostelium_s1.xls: Microsoft excel document containing all the results and genes contained in the microarray.- Dictyostelium_s2.xls: Microsoft excel docume...

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226

Dictyostelium transcriptional responses to Pseudomonas aeruginosa: common and specific effects from PAO1 and PA14 strains

Carilla Latorre, Sergio; Calvo Garrido, Javier; Bloomfield, Gareth; Skelton, Jason; Kay, Robert R.; Ivens, Alasdair; Martínez, José L.; Escalante, Ricardo
2008-06-30

Digital.CSIC (Spain)

228

Deconjugation and bile salts hydrolase activity by Bifidobacterium strains with acquired resistance to bile

Noriega Pérez, Luis; Cuevas, Isabel; Margolles Barros, Abelardo; González de los Reyes-Gavilán, Clara

Deconjugation by bile salts hydrolases in probiotics has been related to reduction of serum cholesterol levels in mammals. We compared the susceptibility to conjugated primary (glycocholate and taurocholate) and secondary (glycodeoxycholate and taurodeoxycholate) salts and the level of hydrolase act...

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229

Deconjugation and bile salts hydrolase activity by Bifidobacterium strains with acquired resistance to bile

Noriega Pérez, Luis; Cuevas, Isabel; Margolles Barros, Abelardo; González de los Reyes-Gavilán, Clara
2005-01-01

Digital.CSIC (Spain)

230

Critical thickness determination of InAs, InP and GaP on GaAs by X-ray interference effect and transmission electron microscopy

Mazuelas, A.; González, Luisa; Ponce, F. A.; Tapfer, L.; Briones Fernández-Pola, Fernando
1993-08-01

Digital.CSIC (Spain)

231

Construction of a Genetically Modified Wine Yeast Strain Expressing the Aspergillus aculeatus rhaA Gene, Encoding an {alpha}-L-Rhamnosidase of Enological Interest

Manzanares, Paloma; Orejas, Margarita; Gil, José Vicente; Graaff, Leo H de; Visser, Jaap; Ramón, Daniel

The Aspergillus aculeatus rhaA gene encoding an {alpha}-L-rhamnosidase has been expressed in both laboratory and industrial wine yeast strains. Wines produced in microvinifications, conducted using a combination of the genetically modified industrial strain expressing rhaA and another strain express...

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232

Construction of a Genetically Modified Wine Yeast Strain Expressing the Aspergillus aculeatus rhaA Gene, Encoding an {alpha}-L-Rhamnosidase of Enological Interest

Manzanares, Paloma; Orejas, Margarita; Gil, José Vicente; Graaff, Leo H. de; Visser, Jaap; Ramón Vidal, Daniel
2003-12-01

Digital.CSIC (Spain)

233

Composition dependence of the phonon strain shift coefficients of SiGe alloys revisited

Reparaz, J. S.; Bernardi, A.; Goñi, A. R.; Alonso, M. I.; Garriga, M.
2008-02-26

Digital.CSIC (Spain)

234

Competitive exclusion of enteropathogens from human intestinal mucus by Bifidobacterium strains with acquired resistance to bile : A preliminary study

Gueimonde Fernández, Miguel; Margolles Barros, Abelardo; González de los Reyes-Gavilán, Clara; Salminen, Seppo

The ability to inhibit the adhesion and to displace selected pathogens from human intestinal mucus of two Bifidobacterium strains with acquired resistance to bile, were assessed and compared with those of their bile sensitive original strains. A preliminary characterization of the macromolecules inv...

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235

Competitive exclusion of enteropathogens from human intestinal mucus by Bifidobacterium strains with acquired resistance to bile : A preliminary study

Gueimonde Fernández, Miguel; Margolles Barros, Abelardo; González de los Reyes-Gavilán, Clara; Salminen, Seppo
2007-01-01

Digital.CSIC (Spain)

236

Comparison of different procedures for serotyping aquatic birnavirus

Novoa, Beatriz; Blake, S.; Nicholson, B. L.; Figueras, Antonio
1995-08-01

Digital.CSIC (Spain)

237

Comparative study of three methods for genotyping hepatitis C virus strains in samples from Spanish patients.

Jimenez De Anta, M T; Simmonds, P; Ampurdanès, S; Forns, X; Rodés, J; López-Labrador, F X; Maluenda, M D; Olmedo, E

Hepatitis C virus (HCV) genotypes may be investigated by a variety of laboratory methods that target different parts of the HCV genome and have various degrees of technical difficulty. Since the choice of a particular method is difficult, we compared the performance of (i) a type-specific PCR with t...

DRIVER (Spanish)

239

Comparative analysis of oxygen consumption rates between cupped oyster spat of Crassostrea gigas of French, Japanese, Spanish and Taiwanese origins

Goulletquer Philippe; Wolowicz Maciej; Latala Adam; Geairon Philippe; Huvet Arnaud; Boudry Pierre

Respiration rates of various geographical strains of Crassostrea gigas were compared to assess the respiratory expenditure as a physiological indicator of catabolism (cost of maintenance). Parental oysters, sampled in France (Marennes-Oleron), Japan (Hiroshima), Taiwan (Tunkang) and Spain (Cadix), w...

DRIVER (Spanish)

240

Comparación de diferentes métodos para identificar las especies del género Proteus/ Comparison of different methods in order to identify Proteus spp

Castro, S. T.; Rodríguez, C. R.; Perazzi, B. E.; Radice, M.; Paz Sticotti, M.; Muzio, H.; Juárez, J.; Gutkind, G.; Famiglietti, A. M. R.; Santini, P. I.; Vay, C. A.
2006-09-01

Resumen en español Los objetivos de este trabajo fueron: a) identificar a nivel de especie aislamientos de Proteus siguiendo la combinación de los esquemas de Farmer y O'Hara; b) determinar la utilidad del sistema comercial API 20E y de un esquema reducido de pruebas (agar TSI y agar MIO: movilidad, indol y ornitina), comparar estos procedimientos con la metodología convencional y evaluar su sensibilidad y especificidad, y c) evaluar la utilidad del perfil proteico en la identificación d (mas) e las distintas especies. Se estudiaron 205 aislamientos de Proteus spp. aislados en el período comprendido entre enero de 1998 y setiembre de 2004, recuperados de distintos materiales clínicos correspondientes a pacientes hospitalizados y ambulatorios atendidos en el Hospital de Clínicas. Los organismos fueron identificados mediante la metodología convencional, por el sistema API 20E y con un esquema reducido de pruebas; 48 de ellos fueron sometidos a un SDS-PAGE. API 20E identificó 79 de 87 aislamientos de P. mirabilis (90,8%), 103/103 del complejo P. vulgaris y 15/15 de P. penneri. Ocho aislamientos identificados como Proteus spp. resultaron ser P. mirabilis, al incluir una prueba adicional (maltosa). En la identificación, el esquema reducido coincidió en un 100% con la metodología convencional. A diferencia del sistema API 20E, el esquema reducido alcanza la correcta identificación de todas las especies en laboratorios de baja complejidad, sin la necesidad de pruebas adicionales. El perfil proteico permitió la correcta diferenciación de las tres especies, independientemente de las diferentes atipias de P. mirabilis. Resumen en inglés The objectives were: a) to identify Proteus strains to species level, following Farmer's and O'Hara's conventional biochemical reactions; b) to evaluate the sensitivity and specificity of both the API 20E method and a schema of reduced reactions (TSI and MIO agar: motility, indole and ornithine) comparing them with conventional methodology, and c) to evaluate the utility of SDS-PAGE (total proteins) in order to identify Proteus strains to species level. Two hundred and fi (mas) ve Proteus spp. clinical isolates, were collected between January 1998 and September 2004, from inpatients and outpatients at Hospital de Clínicas. Strains were identified by means of conventional methodology, the API 20E method, and a schema of reduced reactions. SDS-PAGE (total proteins) was used in 48 out of the 205 strains. The API 20E method identified 79 out of 87 (90.8%) strains of P. mirabilis, 103 out of 103 P. vulgaris complex, and 15 out of 15 P. penneri. Eight strains of P. mirabilis were identified as Proteus spp., the acid production from maltose being necessary to identify them to species level. The schema of reduced reactions identified 205 out of 205 (100%) strains, that is, this schema of reduced reactions identified all the strains to species level without any additional tests, in marked contrast to the API 20E method. The SDS-PAGE (total proteins) identified the three species of the genus, even if the strains of P. mirabilis showed different biochemical reactions.

Scientific Electronic Library Online (Spanish)

241

Chemical composition and strain distribution of InAs/GaAs(001) stacked quantum rings

Ben, Teresa; Sánchez, A. M.; Molina, Sergio I.; Granados, Daniel; García, Jorge M.; Kret, S.
2005-01-01

Digital.CSIC (Spain)

242

Characterization of plasmids from Listeria monocytogenes and Listeria innocua strains isolated from short-ripened cheeses

Margolles, Abelardo; González de los Reyes-Gavilán, Clara

The plasmid content of 30 isolates of Listeria monocytogenes and 18 isolates of Listeria innocua obtained from short-ripened cheeses was analysed. The isolates of L. monocytogenes serogroup 1 harboured a single plasmid, pLM33 (33.2 kbp), whereas the serogroup 4 isolates did not contain plasmids. One...

DRIVER (Spanish)

243

Characterization of muscle sarcoplasmic and myofibrillar protein hydrolysis caused by Lactobacillus plantarum

Fadda, Silvina; Sanz, Yolanda; Vignolo, Graciela; Oliver, Guillermo; Toldrá Vilardell, Fidel

Strains of Lactobacillus plantarum originally isolated from sausages were screened for proteinase and aminopeptidase activities toward synthetic substrates; on the basis of that screening, L. plantarum CRT, 681 was selected for further assays on muscle proteins. The activities of whole cells, cell e...

DRIVER (Spanish)

244
245

Characterization of a novel Lactobacillus species closely related to Lactobacillus johnsonii using a combination of molecular and comparative genomics methods

Sarmiento-Rubiano, Luz-Adriana; Berger, Bernard; Déborah, Moine; Zúñiga, Manuel; Pérez Martínez, Gaspar; Yebra, María Jesús
2010-09-17

Digital.CSIC (Spain)

247

Characterisation of the rhodanese enzyme in Trichoderma spp

Mufaddal, I. Ezzi; Pascual, J. A.; Gould, Barry J.; Lynch, J. M.
2003-04-08

Digital.CSIC (Spain)

248

Carotenoid production in Lactobacillus plantarum

Garrido Fernández, Juan; Maldonado-Barragán, Antonio; Caballero-Guerrero, Belén; Hornero Méndez, Dámaso; Ruiz-Barba, José Luis
2010-01-10

Digital.CSIC (Spain)

249

Caracterización molecular en aislados chilenos de Streptococcus agalactiae/ Molecular characterization of Chilean isolates of streptococcus agalactiae

Rojo, Patricia; Araya, Pamela; Martínez T, M Angélica; Hormazábal, Juan Carlos; Maldonado, Aurora; Fernández, Jorge
2008-05-01

Resumen en inglés Streptococcus agalactiae is the main causing organism of invasive infections such as sepsis and meningitis in the newborn. Aim: To perform a genotype characterization of Streptococcus agalactiae strains coming form invasive infections of newborns and colonized pregnant women. Material and methods: A group of 58 strains not related epidemiologically isolated from colonized pregnant women and invasive infections in newborns, were studied. Pulsed field electrophoresis (PFGE) (mas) and polymerase chain reaction amplification of hylB and IS 1548 genes, as possible virulence markers, were performed. Results: Among the studied strains, 37 genetic subtypes were observed. There were nine groups of identical PFGE patterns. Three corresponded to serotype la and six to serotype III. An erythromycin and clindamycin resistant clone was identified in three colonized women and a newborn with sepsis, which were not epidemiologically related. The hylB gene was equally present in cases of neonatal meningitis or colonized pregnant women. Conclusions: There was a great degree of polymorphism among the studied strains. The ample presence of hylB gene and the absence of the insertion element IS1548 in the hylB gene in invasive and colonizing strains, indicates that both groups of strains are potentially pathogenic

Scientific Electronic Library Online (Spanish)

250

Candidiasis invasoras en el paciente crítico adulto/ Invasive candidiasis in critically ill adult patient

Tobar A, Eduardo; Silva O, Francisco; Olivares C, Roberto; Gaete G, Pablo; Luppi N, Mario
2011-02-01

Resumen en español Las infecciones invasoras por Candida spp, representan una patología relevante en los pacientes críticos. Para su oportuno diagnóstico es necesaria una elevada sospecha clinica, tomando en consideración el cuadro clinico y la presencia de factores de riesgo. Pese a la incorporación de nuevos fármacos al arsenal terapéutico durante la última década, mantiene una elevada mortalidad. Las claves para mejorar los desenlaces clínicos en estos pacientes son el empleo d (mas) e una terapia precoz, eficaz y que permita la cobertura de distintas especies de Candida: C albicans y no albicans. Recientes guías internacionales sugieren la terapia empírica con equinocandinas ante la sospecha de candidiasis invasora en esta población de pacientes. Este grupo de fármacos ha documentado adecuada eficacia clínica y seguridad en estos pacientes. Se espera que la incorporación de nuevas equinocandinas al mercado aminore sus costos y mejore el acceso a este grupo de fármacos Resumen en inglés Invasive infections by Candida strains are a relevant pathology in critically ill patients. Candida should be considered where a high risk of infection is present for a critical early diagnosis. Despite the incorporation of new drugs in the therapeutic armamentarium over the last decade, mortality remains high. The key in improving clinical outcomes of these patients are the use of early effective therapies that offer coverage against different strains of Candida: C. albi (mas) cans and non-albicans. Recent international guidelines suggest empiric therapy with echinocandins in suspected invasive candidiasis in this patient population. This group of drugs adequately documented clinical efficacy and safe use in these patients. The emergence of new echinocandins could improve access to these drugs by reducing their cost

Scientific Electronic Library Online (Spanish)

251

Burkholderia ferrariae sp. nov., a novel bacterium isolated from an iron ore in Brazil.

Valverde, A.; Delvasto, P.; Peix, A.; Velázquez, E.; Santa Regina, I.; Ballester, A.; Rodríguez-Barrueco, C.; García-Balboa, C.; Igual, J. M.
2006-01-01

Digital.CSIC (Spain)

252

Biología molecular en Infectología: Parte II: Diagnóstico molecular de agentes infecciosos/ Molecular biology in infectious diseases: Part II: Molecular diagnosis of infectious agents

Corvalán R, Alejandro; Aguayo G, Francisco; Lévican G, Jorge; Corvalán V, Ignacio
2003-01-01

Resumen en inglés The diagnostic applications of the molecular biology in infectious diseases are wide and applicable to any diagnostic problem. In the Herpesviridae family, the most used methods are those based on the amplification of DNA polymerase gene for the detection of HSV 1 and 2, varicela-zoster, citomegalovirus, Epstein Barr virus and HHV6 simultaneously. This methodology has been able of detect the co-infection of HSV1 and VZV in samples of CNS fluid. In citomegalovirus, molecul (mas) ar methods are used in the monitoring of the reactivation of CMV in immunosuppressed patients and are able to detect viral reactivation within 1 week before symptoms. The molecular methods are also able to identify the Epstein-Barr virus in a proportion of 8 to 20% of gastric cancer cases harboring a unique strain in spite of the presence multiples strains in the healthy population. These associations between virus and cancer have also been described for the human papilloma virus and esophageal and lung cancer. In bacterial agents, the detection and quantification of Bordetella pertussis is another interesting application since it might become a method for rapid diagnosis and predictive of severity in children less than 6 months old. The identification of Helicobacter pylori strains in relation to gastric cancer and peptic ulcer disease and the characterization of strains of methicillin resistant Staphylococcus aureus are other examples of potential applications of the molecular methods in typing microorganisms. In the diagnosis of respiratory tract infectious agents such as Mycobacterium tuberculosis, Pneumocystis carinii and atypical agents, the molecular methods allow the diagnosis in non-invasive samples. Finally, these new methodologies also contribute to the diagnosis of systemic mycotic agents (Candidiasis and Aspergillosis) particularly in immunosuppressed patients

Scientific Electronic Library Online (Spanish)

253

Biodiversity of populations of phosphate solubilizing rhizobia that nodulates chickpea in different Spanish soils.

Rivas, R.; Peix, A.; Mateos, P. F.; Trujillo, M. E.; Martínez-Molina, E.; Velázquez, E.
2007-01-01

Digital.CSIC (Spain)

254

Bioconversion of anthocyanin glycosides by Bifidobacteria and Lactobacillus

Ávila, Marta; Hidalgo, María; Sánchez-Moreno, Concepción; Peláez Martínez, María Carmen; Requena Rolanía, María Teresa; Pascual-Teresa, Sonia de
2009-12-01

Digital.CSIC (Spain)

255

Bile-resistant derivatives obtained from non-intestinal dairy lactobacilli

Burns, Patricia; Vinderola, Gabriel; Binetti, Ana G.; Quiberoni, Andrea; González de los Reyes-Gavilán, Clara; Reinheimer, Jorge A.
2007-11-13

Digital.CSIC (Spain)

256

Bifidobacterium exopolysaccharides fermented by human microbiota

Salazar Garzo, Nuria; Gueimonde Fernández, Miguel; Hernández-Barranco, Ana María; Ruas-Madiedo, Patricia

Eleven exopolysaccharides (EPS) isolated from different human intestinal Bifidobacterium strains were tested in fecal slurry batch cultures and compared with glucose and the prebiotic inulin, for their ability to act as fermentable substrates for intestinal bacteria. During incubation, the increase ...

DRIVER (Spanish)

257

Bacteriocin production and competitiveness of Lactobacillus plantarum LPCO10 in olive juice broth, a culture medium obtained from olives

Leal-Sánchez, M. Vega; Baras, M.; Ruiz-Barba, José Luis; Floriano Pardal, Belén; Jiménez Díaz, Rufino
1998-08-18

Digital.CSIC (Spain)

259

Análisis de observaciones de marea de extensión en Lanzarote

Arnoso, José; Vieira, Ricardo; Vélez, Emilio; Cai, Weixin; Tan, Shiling; Venedikov, A. P.
2003-01-01

Digital.CSIC (Spain)

260

Antimicrobial susceptibility of Streptococcus pneumoniae: serotype distribution of penicillin-resistant strains in Spain.

Casal, J

This study examined the resistance to penicillin, tetracycline, erythromycin, and chloramphenicol of 318 pneumococcal strains isolated in Spanish hospitals from blood or cerebrospinal fluid of patients during 1979 to 1981. The serotypes of these strains were determined to discover whether a correlat...

DRIVER (Spanish)

261

Antimicrobial Resistance and Spread of Class 1 Integrons among Salmonella Serotypes

Mendoza, M. Carmen; Guerra, Beatriz; Cal, Santiago; Soto, Sara

The resistance profiles, for 15 antimicrobial agents, of 333 Salmonella strains representing the most frequent nontyphoidal serotypes, isolated between 1989 and 1998 in a Spanish region, and 9 reference strains were analyzed. All strains were susceptible to amikacin, ceftazidime, ciprofloxacin, and ...

DRIVER (Spanish)

262

Antigenic characterization of intermediate adenovirus 14-11 strains associated with upper respiratory illness in a military camp.

Hierholzer, J C; Pumarola, A

An unusual variant of adenovirus (AV) 11 was isolated from throat and rectal swabs from six persons with upper respiratory illness in a Spanish military camp in March 1969. The same strain was serologically related to the upper respiratory illness of seven other men among 25 sample cases studied in ...

DRIVER (Spanish)

265

Analysis and dynamics of the chromosomal complements of wild sparkling-wine yeast strains

Nadal, Dolors; Carro, David; Fernández-Larrea, Juan; Piña, Benjamín
1999-04-01

Digital.CSIC (Spain)

267

Allopatric speciation in ticks: genetic and reproductive divergence between geographic strains of Rhipicephalus (Boophilus) microplus

Labruna, Marcelo B.; Naranjo, Victoria; Mangold, Atilio J.; Thompson, Carolina; Estrada-Peña, Agustín

12 pages, 5 figures.-- PMID: 19243585 [PubMed].-- PMCID: PMC2656471.-- Supporting information (Microsatellite genotypes of individual tick crosses, XLS file) available at: http://www.biomedcentral.com/content/supplementary/1471-2148-9-46-s1.xls | [Background] The cattle tick, Rhipicephalus (Boophilu...

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268

Allopatric speciation in ticks: genetic and reproductive divergence between geographic strains of Rhipicephalus (Boophilus) microplus

Labruna, Marcelo B.; Naranjo, María Victoria; Mangold, Atilio J.; Thompson, Carolina; Estrada-Peña, Agustín; Guglielmone, Alberto A.; Jongejan, Frans; Fuente García, José de la
2009-02-25

Digital.CSIC (Spain)

269

Activities of Six Different Quinolones against Clinical Respiratory Isolates of Streptococcus pneumoniae with Reduced Susceptibility to Ciprofloxacin in Spain

Aguilar, L.; Pérez-Trallero, E.; Martín-Sánchez, A. M.; García-Rey, C.; García-de-Lomas, J.; Ruiz, J.

Six quinolones were tested on 817 consecutive pneumococcal isolates for which ciprofloxacin MICs were high (≥2 μg/ml); the isolates had been collected during two recent Spanish surveillance studies. For strains for which the ciprofloxacin MIC was ≥4 μg/ml, the MICs at which 90% of the isolates teste...

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270

A Method for Estimation of Population-Densities of Ice Nucleating Active Pseudomonas-Syringae in Buds and Leaves of Mango

Cazorla, F.M.; Olalla, L.; Torés, J.A.; Pérez-Garcia, A.; Codina, J.C.; Vicente, A. de

Active ice nucleation strains of Pseudomonas syringae pv. syringae have been associated with a necrotic disease in mango trees growing in Málaga (southern Spain). In this paper a simple multiple-tube test is described to estimate the number of active ice nucleation bacteria associated with plant tis...

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271

A Method for Estimation of Population-Densities of Ice Nucleating Active Pseudomonas-Syringae in Buds and Leaves of Mango

Cazorla, F.M.; Olalla, L.; Torés Montosa, Juan Antonio; Pérez-García, A.; Codina, J.C.; Vicente, A. de
1995-04-05

Digital.CSIC (Spain)

272

Marin, P; Jurado, M; Magan, Naresh; Vazquez, C; Gonzalez-Jaen, MT

DRIVER (Spanish)