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Sample records for bacteriophora poinar cepa

  1. Susceptibility of larvae of Aedes aegypti (Linnaeus (Diptera: Culicidae to entomopathogenic nematode Heterorhabditis bacteriophora (Poinar (Rhabditida: Heterorhabditidae

    Directory of Open Access Journals (Sweden)

    María L. PESCHIUTTA

    2014-01-01

    Full Text Available Aedes aegypti (Linnaeus (Diptera: Culicidae es vector de los agentes etiológicos de la fiebre amarilla y del dengue. Una alternativa al control químico de este vector es el uso de agentes biológicos. Los nematodos entomopatógenos son efectivos en el control de plagas. La infectividad y el ciclo de vida de un aislado argentino de Heterorhabditis bacteriophora Poinar (Rhabditida: Heterorhabditidae en larvas de A. aegypti se registró por primera vez bajo condiciones de laborato - rio. Para cada unidad experimental, 30 larvas de mosquito de segundo estadio fueron expuestas a 8 dosis del nematodo (0:1, 1:1, 5:1, 15:1, 100:1, 500:1, 750:1, 1500:1. Los juveniles infectivos (JIs utilizados fueron multiplicados sobre Galleria mellonella (Lepidoptera: Pyralidae. La continuidad infectiva de los JIs obtenidos de A. aegypti fue probada aplicándolos en una dosis de 100:1 sobre larvas del mosquito . Las tasas de mortalidad fueron de 0% a 84%. El número de nematodos desarrollados dentro de la larva de mosquito, la mortalidad larval y los nuevos JIs se incrementaron con el aumento de la dosis de nematodos. Los resultados indican que H. bacteriophora es capaz de infectar larvas de A. aegypti , se desarrolla y produce nuevos JIs, permitiendo la continuidad de su ciclo de vida.

  2. Acción patogénica de Heterorhabditis bacteriophora (Poinar) sobre el caracol manzana (Pomacea canaliculata Lamarck), plaga de los cultivos de arroz (Oriza sativa) en la cuenca baja del río Daule, Guayas, Ecuador

    OpenAIRE

    G. A. Salcedo

    2013-01-01

    Los cultivos de arroz en la cuenca baja del río Daule, Ecuador, son afectados por el caracol manzana. La pérdida estimada es de 40 al 60% de la producción/ha. El agricultor, para evitar pérdidas considerables, aplica agroquímicos en dosis elevadas, desequilibrando la fauna y microfauna nativa, agravando el problema. Razón por la cual, se evaluó la patogenicidad de H. bacteriophora sobre el caracol manzana, con tres dosis; mediante un diseño completamente al azar (DCA) con cuatro tratamientos ...

  3. Acción patogénica de Heterorhabditis bacteriophora (Poinar sobre el caracol manzana (Pomacea canaliculata Lamarck, plaga de los cultivos de arroz (Oriza sativa en la cuenca baja del río Daule, Guayas, Ecuador

    Directory of Open Access Journals (Sweden)

    G. A. Salcedo

    2013-01-01

    Full Text Available Los cultivos de arroz en la cuenca baja del río Daule, Ecuador, son afectados por el caracol manzana. La pérdida estimada es de 40 al 60% de la producción/ha. El agricultor, para evitar pérdidas considerables, aplica agroquímicos en dosis elevadas, desequilibrando la fauna y microfauna nativa, agravando el problema. Razón por la cual, se evaluó la patogenicidad de H. bacteriophora sobre el caracol manzana, con tres dosis; mediante un diseño completamente al azar (DCA con cuatro tratamientos y cinco repeticiones. Los resultados muestran el 100% de mortalidad por septicemia a las 96 horas de la inoculación, con relación al testigo.

  4. Transcriptomic analysis of the entomopathogenic nematode Heterorhabditis bacteriophora TTO1

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    Spieth John

    2009-04-01

    Full Text Available Abstract Background The entomopathogenic nematode Heterorhabditis bacteriophora and its symbiotic bacterium, Photorhabdus luminescens, are important biological control agents of insect pests. This nematode-bacterium-insect association represents an emerging tripartite model for research on mutualistic and parasitic symbioses. Elucidation of mechanisms underlying these biological processes may serve as a foundation for improving the biological control potential of the nematode-bacterium complex. This large-scale expressed sequence tag (EST analysis effort enables gene discovery and development of microsatellite markers. These ESTs will also aid in the annotation of the upcoming complete genome sequence of H. bacteriophora. Results A total of 31,485 high quality ESTs were generated from cDNA libraries of the adult H. bacteriophora TTO1 strain. Cluster analysis revealed the presence of 3,051 contigs and 7,835 singletons, representing 10,886 distinct EST sequences. About 72% of the distinct EST sequences had significant matches (E value H. bacteriophora, among which are those encoding F-box-like/WD-repeat protein theromacin, Bax inhibitor-1-like protein, and PAZ domain containing protein. Gene Ontology terms were assigned to 6,685 of the 10,886 ESTs. A total of 168 microsatellite loci were identified with primers designable for 141 loci. Conclusion A total of 10,886 distinct EST sequences were identified from adult H. bacteriophora cDNA libraries. BLAST searches revealed ESTs potentially involved in parasitism, RNA interference, defense responses, stress responses, and dauer-related processes. The putative microsatellite markers identified in H. bacteriophora ESTs will enable genetic mapping and population genetic studies. These genomic resources provide the material base necessary for genome annotation, microarray development, and in-depth gene functional analysis.

  5. Postembryonic RNAi in Heterorhabditis bacteriophora: a nematode insect parasite and host for insect pathogenic symbionts

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    Sternberg Paul W

    2007-09-01

    Full Text Available Abstract Background Heterorhabditis bacteriophora is applied throughout the world for the biological control of insects and is an animal model to study interspecies interactions, e.g. mutualism, parasitism and vector-borne disease. H. bacteriophora nematodes are mutually associated with the insect pathogen, Photorhabdus luminescens. The developmentally arrested infective juvenile (IJ stage nematode (vector specifically transmits Photorhabdus luminescens bacteria (pathogen in its gut mucosa to the haemocoel of insects (host. The nematode vector and pathogen alone are not known to cause insect disease. RNA interference is an excellent reverse genetic tool to study gene function in C. elegans, and it would be useful in H. bacteriophora to exploit the H. bacteriophora genome project, currently in progress. Results Soaking L1 stage H. bacteriophora with seven dsRNAs of genes whose C. elegans orthologs had severe RNAi phenotypes resulted in highly penetrant and obvious developmental and reproductive abnormalities. The efficacy of postembryonic double strand RNA interference (RNAi was evident by abnormal gonad morphology and sterility of adult H. bacteriophora and C. elegans presumable due to defects in germ cell proliferation and gonad development. The penetrance of RNAi phenotypes in H. bacteriophora was high for five genes (87–100%; Hba-cct-2, Hba-daf-21, Hba-icd-1; Hba-nol-5, and Hba-W01G7.3 and moderate for two genes (usually 30–50%; Hba-rack-1 and Hba-arf-1. RNAi of three additional C. elegans orthologs for which RNAi phenotypes were not previously detected in C. elegans, also did not result in any apparent phenotypes in H. bacteriophora. Specific and severe reduction in transcript levels in RNAi treated L1s was determined by quantitative real-time RT-PCR. These results suggest that postembryonic RNAi by soaking is potent and specific. Conclusion Although RNAi is conserved in animals and plants, RNAi using long dsRNA is not. These results

  6. Transcriptional profiling of trait deterioration in the insect pathogenic nematode Heterorhabditis bacteriophora

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    Shapiro-Ilan David I

    2009-12-01

    Full Text Available Abstract Background The success of a biological control agent depends on key traits, particularly reproductive potential, environmental tolerance, and ability to be cultured. These traits can deteriorate rapidly when the biological control agent is reared in culture. Trait deterioration under laboratory conditions has been widely documented in the entomopathogenic nematode (EPN Heterorhabditis bacteriophora (Hb but the specific mechanisms behind these genetic processes remain unclear. This research investigates the molecular mechanisms of trait deterioration of two experimental lines of Hb, an inbred line (L5M and its original parental line (OHB. We generated transcriptional profiles of two experimental lines of Hb, identified the differentially expressed genes (DEGs and validated their differential expression in the deteriorated line. Results An expression profiling study was performed between experimental lines L5M and OHB of Hb with probes for 15,220 ESTs from the Hb transcriptome. Microarray analysis showed 1,185 DEGs comprising of 469 down- and 716 up-regulated genes in trait deteriorated nematodes. Analysis of the DEGs showed that trait deterioration involves massive changes of the transcripts encoding enzymes involved in metabolism, signal transduction, virulence and longevity. We observed a pattern of reduced expression of enzymes related to primary metabolic processes and induced secondary metabolism. Expression of sixteen DEGs in trait deteriorated nematodes was validated by quantitative reverse transcription-PCR (qRT-PCR which revealed similar expression kinetics for all the genes tested as shown by microarray. Conclusion As the most closely related major entomopathogen to C. elegans, Hb provides an attractive near-term application for using a model organism to better understand interspecies interactions and to enhance our understanding of the mechanisms underlying trait deterioration in biological control agents. This information

  7. Effects of tannin-rich host plants on the infection and establishment of the entomopathogenic nematode Heterorhabditis bacteriophora.

    Science.gov (United States)

    Glazer, Itamar; Salame, Liora; Dvash, Levana; Muklada, Hussein; Azaizeh, Hassan; Mreny, Raghda; Markovics, Alex; Landau, SergeYan

    2015-06-01

    Parasitized animals can self-medicate. As ingested plant phenolics, mainly tannins, reduce strongyle nematode infections in mammalian herbivores. We investigated the effect of plant extracts known to be anthelmintic in vertebrate herbivores on the recovery of the parasitic entomopathogenic nematode Heterorhabditis bacteriophora infecting African cotton leafworm (Spodoptera littoralis). Nematode infective juveniles (IJs) were exposed to 0, 300, 900, 1200, 2400 ppm of Pistacia lentiscus L. (lentisk), Inula viscosa L. (strong-smelling inula), Quercus calliprinos Decne. (common oak) and Ceratonia siliqua L. (carob) extracts on growth medium (in vitro assay). In control treatments, 50-80% of IJs resumed development to J4, young and developed adult hermaphrodites, whereas all extracts, except for C. siliqua at 300 ppm, impaired IJ exsheathment and development. The highest concentration of I. viscosa extract (2400 ppm) had the strongest effect, killing 95% of exposed nematodes. Surviving nematodes did not recover, remaining at the IJ stage. Over the whole cycle, I. viscosa extract inhibited recovery to 25% or less, and did not allow full development to adulthood, whereas 65% of IJs in the control treatment recovered and resumed development, 12% reaching complete maturation within 72 h of incubation. When herbivorous S. littoralis larvae were fed with different plant extracts in vivo, I. viscosa had the strongest effect at concentrations above 300 ppm, with 90% of insect-invading IJs not developing to parasitic stages, whereas in the control treatment, 85% of IJs resumed development. Exposure to C. siliqua extract also inhibited exsheathment and development of 75% of the IJs. Half of those that resumed development reached full maturation. P. lentiscus and Q. calliprinos extracts also inhibited development of 50% IJs. Our results suggest that H. bacteriophora can be used to study herbal medication against parasites in animals.

  8. CEPA:物流业的机遇%CEPA:opportunities for logistics industry

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    @@ The Chinese mainland/Hong Kong Closer Economic Partnership Arrangement (CEPA) became effective from zero hour Thursday, January 1,2004, with the support of the central government and joint efforts of the industry and commerce circles on both sides.

  9. CEPA--opportunities for logistics industry

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    The Chinese mainland/HongKong CloserEconomic Partnership Arrangement(CEPA)became effective from zero hour Thursday,January 1,2004,with the support of the cen-tral government and joint efforts of the indus-try and commerce circles on both sides.

  10. Antimutagenic potential of curcumin on chromosomal aberrations in Allium cepa

    Institute of Scientific and Technical Information of China (English)

    RAGUNATHAN Irulappan; PANNEERSELVAM Natarajan

    2007-01-01

    Turmeric has long been used as a spice and food colouring agent in Asia. In the present investigation, the antimutagenic potential of curcumin was evaluated in Allium cepa root meristem cells. So far there is no report on the biological properties of curcumin in plant test systems. The root tip cells were treated with sodium azide at 200 and 300 μg/ml for 3 h and curcumin was given at 5, 10 and 20 μg/ml for 16 h, prior to sodium azide treatment. The tips were squashed after colchicine treatment and the cells were analyzed for chromosome aberration and mitotic index. Curcumin induces chromosomal aberration in Allium cepa root tip cells in an insignificant manner, when compared with untreated control. Sodium azide alone induces chromosomal aberrations significantly with increasing concentrations. The total number of aberrations was significantly reduced in root tip cells pretreated with curcumin. The study reveals that curcumin has antimutagenic potential against sodium azide induced chromosomal aberrations in Allium cepa root meristem cells. In addition, it showed mild cytotoxicity by reducing the percentage of mitotic index in all curcumin treated groups, but the mechanism of action remains unknown. The antimutagenic potential of curcumin is effective at 5 μg/ml in Allium cepa root meristem cells.

  11. Acetic acid: Crop injury and onion (Allium cepa L.) yields

    Science.gov (United States)

    Weed control is a major challenge in conventional and organic production systems, especially for organically produced sweet onion (Allium cepa L.). Organic herbicides for sweet onions are limited to non-selective materials, such as corn gluten meal and vinegar. Research at Lane, Oklahoma has shown...

  12. AISLAMIENTO Y CARACTERIZACIÓN DE CEPAS DE Gluconacetobacter diazotrophicus

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    Yoania Ríos Rocafull

    2016-01-01

    Full Text Available Gluconacetobacter diazotrophicus es un microorganismo endófito que presenta, dentro de sus características, mecanismos directos e indirectos de estimulación del crecimiento vegetal. A pesar de sus grandes perspectivas para constituir el principio activo de un bioproducto de uso agrícola, en Cuba no existe ninguno elaborado a partir de esta especie bacteriana. El aislamiento de cepas del microorganismo y su caracterización constituyen pasos importantes para la obtención de un biopreparado, pues permiten la selección inicial de cepas que tengan características adecuadas para la estimulación del crecimiento. En la presente investigación se purificaron 85 aislados de microorganismos endófitos, a partir de los diferentes órganos de 24 especies vegetales. Cuatro de ellos fueron identificados como Gluconacetobacter diazotrophicus, al comparar sus características con las de cepas patrones de la especie bacteriana. Los microorganismos seleccionados provenían de frutos de guayaba (Psidium guajava L. y mango (Mangifera indica L., así como de tallos de yuca (Manihot esculenta Crantz. y remolacha (Beta vulgaris L.. Se destacó la presencia del microorganismo en los dos primeros cultivos para Cuba y el aislamiento en la guayaba a nivel internacional. Las cuatro cepas mostraron diferencias en su capacidad de solubilizar fósforo, producir ácido indol acético y en su actividad antagonista frente a Fusarium moniliforme y Fusarium incarnatum. Al agruparse las cepas por sus características, se diferenciaron los microorganismos provenientes de mango y remolacha, los que se consideran promisorios para realizar estudios en condiciones in vivo del efecto de su interacción con otros cultivos.

  13. Ultrastructural localization of active genes in Allium cepa cells

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    By using the anti-RNA/DNA hybrid antibody as the probe, we labeled and analyzed the precise transcriptional sites of active genes in Allium cepa cells in situ. The results showed that the location of labeled signals appeared in mitochondrion was the same as that in chloroplast, generally concentrated at the central matrix space where there were no cristae and thylakoids. In the extranucleolar regions of nucleus, the labeled signals of transcriptional sites were situated at the perichromatin fibrils, which decondensed and stretched out from the chromosome territories. Our results also displayed the concentrations of labeled signals in a cer-tain region of nucleus, and this means that the gene tran-scription rich region actually existed in Allium cepa cells. In nucleolus, the synthetic sites of rRNA were localized not only to the periphery of fibrillar centers but also to the DFC near FC.

  14. Fenoloxidasa Modificada: Clave para identificar cepas de Cryptococcus neoformans

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    Carlos Canelo D

    2000-01-01

    Full Text Available Cryptococcus neoformans es la única levadura patógena capaz de sintetizar pigmentos como la melanina mediante la actividad de su enzima llamada fenoloxidasa. El objetivo del presente estudio fue implementar y estandarizar la prueba de la fenoloxidasa, como técnica complementaria en la identificación de cepas de C. neoformans. Se estudiaron 21 cepas, identificadas previamente con métodos convencionales. La prueba de la fenoloxidasa fue modificada debido a que su empleo originaba 9,6% (2/21 de falsa negatividad. Esta prueba modificada se optimizó a 28°C a partir de un medio con baja concentración de glucosa. Ningún aislamiento falso negativo fue encontrado luego de repetir tres veces el ensayo, y el pigmento melanina fue detectado con mayor rapidez.

  15. CEPA and interrelationship between Chinese yuan and Hong Kong dollar

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In order to explore the interrelated impacts of the economical communications between China and Hong Kong SAR, especially after the closer economic partnership arrangement (CEPA) and the Chinese yuan offshore financial business in Hong Kong banks in 2004, the exchange rates of the Chinese yuan and the Hong Kong dollar are investigated as well-performing market signals that should reflect this historical transformation. With vector autoregressive models (VAR), the Johansen cointegration test and the Granger ...

  16. The Effect of CEPA is Showing up at the 700th Day

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ Nov. 30 is the 700th day that CEPA was implemented. At the forum on the Simp1ification of CEPA Trade and Custom Declaration, It is learned that after the execution of CEPA, the exchanges of logistics, Human Resources, capital and information between the mainland and Hong Kong and Macao are getting more and more frequent, which inputs new energy into the promotion of Hong Kong and Macao economic growth. At the same time, the effect is showing up.

  17. Neuroprotective effect of Allium cepa L. in aluminium chloride induced neurotoxicity.

    Science.gov (United States)

    Singh, Tanveer; Goel, Rajesh Kumar

    2015-07-01

    The present study was envisaged to investigate the neuroprotective potential of Allium cepa (A. cepa) in aluminium chloride induced neurotoxicity. Aluminium chloride (50 mg/kg/day) was administered orally in mice supplemented with different doses of A. cepa hydroethanolic extract for a period of 60 days. Various behavioural, biochemical and histopathological parameters were estimated in aluminium exposed animals. Chronic aluminium administration resulted in significant motor incoordination and memory deficits, which were also endorsed biochemically as there was increased oxidative stress as well as elevated acetylcholinesterase (AChE) and aluminium levels in the brain. Supplementation with A. cepa in aluminium exposed animals significantly improved muscle coordination and memory deficits as well as reduced oxidative stress, AChE and decreased abnormal aluminium deposition in the brain. Histopathologically, there was marked deterioration visualized as decreased vacuolated cytoplasm as well as decreased pyramidal cells in the hippocampal area of mice brain which were found to be reversed with A. cepa supplementation. Administration of BADGE (PPARγ antagonist) in aluminium exposed animals reversed the neuroprotective potential of A. cepa as assessed with various behavioural, biochemical, neurochemical and histopathological estimations. In conclusion, finding of this study suggested significant neuroprotective potential of A. cepa in aluminium induced neurotoxicity. Further, the role of PPARγ receptor agonism has also been suggested as a putative neuroprotective mechanism of A. cepa, which needs further studies for confirmation.

  18. Interaction of Natural Dye (Allium cepa with Ionic Surfactants

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    Shalini Chandravanshi

    2013-01-01

    Full Text Available Allium cepa is a natural dye that has been extracted from onion skin with the help of soxhlet apparatus. The pigment in the dye pelargonidin was found to be 2.25%. The interaction of the dye with ionic surfactants, namely, cationic surfactant (cetyltrimethylammonium bromide and anionic (sodium lauryl sulphate has been studied by spectrophotometrically, conductivity, and surface tension measurements. The thermodynamic and surface parameters have been evaluated for the interaction process. The results indicate {surfactant-dye} complex formation and domination of adsorption in comparison to micellization.

  19. Tracking Environmental Crime Through CEPA: Canada's Environment Cops or Industry's Best Friend?

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    April L. Girard

    2010-01-01

    Full Text Available This paper examines shifts in the regulation and governance of environmental crime over the twenty-year period since the passage of the Canadian Environmental Protection Act (CEPA in 1988, tracing its history, policies, and enforcement record from 1989–2008. Documents assessed include Environment Canada’s enforcement data, Annual Reports, reports on its Plans and Priorities,the Senate and House of Commons five-year reviews of CEPA 1988 and CEPA 1999 and the government’s response to these reviews. The purpose of the paperis to document the process and compromises that have shaped federal environmental protection, and explore the policy paralysis this has produced.

  20. The Effect of CEPA is Showing up at the 700th Day

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

      Nov. 30 is the 700th day that CEPA was implemented. At the forum on the Simp1ification of CEPA Trade and Custom Declaration, It is learned that after the execution of CEPA, the exchanges of logistics, Human Resources, capital and information between the mainland and Hong Kong and Macao are getting more and more frequent, which inputs new energy into the promotion of Hong Kong and Macao economic growth. At the same time, the effect is showing up.……

  1. Fatal onion (Allium cepa) toxicosis in water buffalo (Bubalus bubalis).

    Science.gov (United States)

    Borelli, Vanessa; Lucioli, Joelma; Furlan, Fernando Henrique; Hoepers, Patrícia Giovana; Roveda, Juliano Fleck; Traverso, Sandra Davi; Gava, Aldo

    2009-05-01

    Toxicosis caused by the ingestion of onion (Allium cepa) by 5 water buffalo (Bubalus bubalis) occurred in the district of Caçador, Santa Catarina, Brazil. The water buffalo died after ingestion of a large quantity of onion that had been left in the pasture. Clinical signs started 8 days postingestion and were characterized by pale mucous membranes, lethargy, and dark urine. At necropsy, pieces of onions were found in the rumen of 1 animal. The carcass smelled strongly of onion, and the kidneys and urine were dark brown. Microscopic renal lesions included tubular degeneration and necrosis with deposits of eosinophilic material in the cytoplasm of renal tubular epithelial cells and tubular lumina. These changes were consistent with hemoglobinuric nephrosis. Centrilobular coagulation necrosis was observed in the liver accompanied by hemorrhage and macrophages containing brown cytoplasmic pigment. A diagnosis of hemolytic anemia caused by onion toxicosis was based on the epidemiological data, clinical signs, macroscopic changes, and histological lesions. PMID:19407101

  2. Chromosomal and Nuclear Alterations in Root Tip Cells of Allium Cepa L. Induced by Alprazolam

    OpenAIRE

    Nefic, Hilada; Musanovic, Jasmin; Metovic, Azra; Kurteshi, Kemajl

    2013-01-01

    ABSTRACT Introduction: Alprazolam is a triazolobenzodiazepine used in panic disorders and other anxiety states. Target organ of Alprazolam is CNS, causing depression of respiration and consciousness. Aim: This study aimed to estimate the genotoxic potential of Alprazolam using Allium cepa test. Methods: Allium cepa is one of the most suitable plants for detecting different types of xenobiotics. The test enables the assessment of different genetic endpoints making possible damage to the DNA of...

  3. Repairing Effect of Allium Cepa on Testis Degeneration Caused by Toxoplasma Gondii in The Rat

    OpenAIRE

    Yagoob Garedaghi; Seyed Razi Bahavarnia

    2014-01-01

    Objectives: Toxoplasma gondii, an intracellular parasite, infectS a large proportion of the world population yearly. This study was investigated to evaluate the remedial effects of allium cepa on testis degeneration in male rats infected by T.gondii, RH strain. Materials and Methods: Wistar male rats (n=40) divided into control (n=10) and experimental (n=30) groups. The experimental groups were divided into two groups; allium cepa group (n=10) received 1cc of fresh onion juice daily and th...

  4. Compatibilidad entre nueve cepas de Biomphalaria glabrata de áreas endémicas y no endémicas y una cepa de Schistosoma mansoni venezolanas

    Directory of Open Access Journals (Sweden)

    Pino Luz A.

    1999-01-01

    Full Text Available Se infectaron experimentalmente 9 lotes de 32 caracoles B. glabrata (de 5 a 7mm de diámetro con miracidios de la cepa C5 de Schistosoma mansoni a razón de 5 miracidios por caracol, pertenecientes a las siguientes cepas: En el área endémica de transmisión de Esquistosomiasis mansoni a Sector Puerta Negra, Lago Valencia, b Cagua c Ingenio Bolívar (Estado Aragua d Mariara e Caserío El 25 f Güigüe (Estado Carabobo. Fuera del área endémica de transmisión g Anzoátegui (Estado Lara, h Chabasquén (Estado Portuguesa, i Sector La Elvira, Caripe (Estado Monagas. El período prepatente intramolusco, osciló entre 23 y 25 días, para las 9 cepas evaluadas. La duración total de la infección fue muy variable desde 20 días para la cepa Chabasquén, hasta 93 días para la de Güigüe.La producción total promedio de cercarias al tercer día de iniciada la emisión varió desde X = 74,4 para la cepa de Mariara, hasta X = 591,7 para la cepa de Chabasquén. Se evidenció la existencia de diferencias estadísticamente significativas (H = 97,4, P < 0,05 en la producción total de cercarias al tercer día de iniciada la emisión, detectándose diferencias estadísticamente significativas para casi todas las 36 combinaciones, excepto para las cuatro siguientes: Mariara/Ingenio Bolívar, Cagua/Caserío El 25, Lago de Valencia/Güigüe y Güigüe/Caripe.En lo que respecta al porcentaje de caracoles que presentaron cura espontánea, los valores mas elevados se obtuvieron en las cepas del Lago de Valencia (88,8%, Cagua (85,2%, Chabasquén (82,6%, Caripe (82,6% y Anzoátegui (80%. Mientras que el porcentaje mas bajo se obtuvo para la cepa de Güigüe (21,4%.

  5. The Diversity and Abundance of Small Arthropods in Onion, Allium cepa, Seed Crops, and their Potential Role in Pollination

    OpenAIRE

    Walker, M.K.; Howlett, B. G.; Wallace, A.R.; Mccallum, J. A.; Teulon, D.A.J.

    2011-01-01

    Onion, Allium cepa L. (Asparagales: Amaryllidaceae), crop fields grown for seed production require arthropod pollination for adequate seed yield. Although many arthropod species visit A. cepa flowers, for most there is little information on their role as pollinators. Small flower visiting arthropods (body width < 3 mm) in particular are rarely assessed. A survey of eight flowering commercial A. cepa seed fields in the North and South Islands of New Zealand using window traps revealed that sma...

  6. Infectividad de Metarhizium anisopliae en contra de cepas de garrapata Boophilus microplus sensible y resistente a los organofosforados

    OpenAIRE

    Manuel Fernández-Ruvalcaba; Elyes Zhioua; Zeferino García-Vázquez

    2005-01-01

    La infectividad del hongo entomopatogénico Metarhizium anisopliae (Metschnikoff) fue probada en contra de una cepa de Boophilus microplus (Canestrini) sensible, y otra resistente a los organofosforados, por medio de un ensayo in vitro con hembras ingurgitadas de B. microplus recién desprendidas del bovino, utilizando la cepa ECS1 de M. anisopliae. El micromiceto M. anisopliae demostró ser altamente infectivo, tanto para la cepa sensible como para la resistente a los organofosforados a la conc...

  7. CEPA calculations on open-shell molecules. Pt. 11

    International Nuclear Information System (INIS)

    Ab initio calculations at SCF and CEPA levels using large Gaussian basis sets have been performed for the two lowest electronic states, X2Σ+ and A2Π, of HeAr+. Spin-orbit coupling (SOC) effects have been added using a semiempirical treatment. The resulting potential curves for the three states X, A1, and A2 have been used to evaluate molecular constants such as vibrational intervals ΔG(υ+1/2) and rotational constants Bυ as well as - by means of a Dunham expansion - equilibrium constants such as Re, ωe, Be etc. Comparison with the experimental data from UV emission spectroscopy shows that the calculated potential curves are slightly too shallow and have too large equilibrium distances: De=242 cm-1 and Re=2.66 A compared to the experimental values of 262 cm-1 and 2.585 A, respectively, for the X2Σ+ ground state. However, the ab initio calculations yield more bound vibrational levels than observed experimentally and allow for a more complete Dunham analysis, in particular for the A2 state. The experimental value of 154 cm-1 for the dissociation energy De of this state is certainly too low; our best estimate is 180±5 cm-1. For the A1 state our calculations are predictions since this state has not yet been observed experimentally. (orig.)

  8. Micropropagation of onion (Allium cepa L.) from immature inflorescences.

    Science.gov (United States)

    Marinangeli, Pablo

    2013-01-01

    In vitro plant production by direct organogenesis from immature flower heads is an ideal approach for clonal propagation of onions (Allium cepa L.). This technique ensures genetic stability, high propagation rate, and maintains donor plant of explants with an advantage over other means of in vitro regeneration. Onion micropropagation is usually applied in breeding programs, maintenance, and multiplication of cytoplasmic-male sterile lines for hybrid production, germplasm conservation, and as a tool for the application of other biotechnologies. For in vitro culture, mature onion bulbs are induced to reproductive phase by vernalization and forced to inflorescence initiation. Immature umbels are dissected from bulbs or cut directly when they appear from the pseudostem among the leaves. Disinfected inflorescences are cultivated in BDS basal medium supplemented with 30 g/L sucrose, 0.1 mg/L naphthalene acetic acid, 1 mg/L N (6)-benzyladenine, and 8 g/L agar, pH 5.5, under 16 h photoperiod white fluorescent light (PPD: 50-70 μmol/m(2)s) for 35 days. The regenerated shoot clumps are divided and subculture under the same conditions. For bulbification phase, the individual shoots are cultured in BDS basal medium containing 90 g/L sucrose, without plant growth regulators, pH 5.5, under 16 h photoperiod. Microbulbs can be directly cultivated ex vitro without acclimation. PMID:23179710

  9. HEPATOPROTECTIVE ACTIVITY OF ALCOHOLIC AND AQUEOUS EXTRACTS OF ALLIUM CEPA LINN. (LILIACEAE IN RATS

    Directory of Open Access Journals (Sweden)

    Riyaz Shaik et al

    2012-09-01

    Full Text Available In the present study, we have chosen a plant named Allium cepa Linn (Liliaceae to evaluate its hepatoprotective activity in experimental animals. Different pharmacological activities are reported with different parts of this plant. Some of its medicinal properties reported are as stimulant, diuretic, anti-tubercular, anthelmintic, and used for various diseases like diabetes, skin diseases, rheumatism, asthma, nausea and constipation. From the literature we found that A. cepa has also been traditionally indicated for treatment of hepatic disorders. This prompt us to select bulb extracts of this plant for the study of hepatoprotective activity in paracetamol induced hepatotoxicity in experimental animals. Phytochemical screening of A. cepa revealed the presence of Saponins, carbohydrate, steroids, Flavonoids. The present study was made to evaluate the hepatoprotective effect of alcoholic and aqueous extracts of Allium cepa in CCl4 and paracetamol induced hepatic injury in experimental animals. Hepatoprotective activity of A. cepa was studied by estimating the serum levels of serum glutamic oxaloacetic transaminase (SGOT, serum glutamic pyruvic transaminase (SGPT, alkaline phosphatase (ALP, direct and total bilirubin. The treatment with AEAC and AQEAC showed significant reduction of CCl4 and paracetamol induced elevated serum enzyme and pigment levels. Histopathology of liver shows hepatoprotective effect of these extracts.

  10. Towards onions and shallots (Allium cepa L.) resistant to beet armyworm (Spodoptera exigua Hübner) by transgenesis and conventional breeding

    OpenAIRE

    S.J. Zheng

    2000-01-01

    Onion ( Allium cepa L. group Common Onion) and shallot ( A. cepa L. group Aggregatum) are two subspecies of A. cepa . Both onion and shallot together with other Allium species like garlic ( A. sativum ), leek ( A. porrum ) and bunching onion ( A. fistulosum ) are very important vegetable crops on a worldwide scale. A. cepa is cultivated mainly as a biennial but some types are treated as perennials. It is propagated by seeds, bulbs, or sets (small bulbs). TThe bulbs of common onion are large, ...

  11. Towards onions and shallots (Allium cepa L.) resistant to beet armyworm (Spodoptera exigua Hübner) by transgenesis and conventional breeding

    NARCIS (Netherlands)

    Zheng, S.J.

    2000-01-01

    Onion ( Allium cepa L. group Common Onion) and shallot ( A. cepa L. group Aggregatum) are two subspecies of A. cepa . Both onion and shallot together with other Allium species like garlic ( A. sativum ), leek ( A. porrum ) and bunching onion ( A. fistulosum ) are very important vegetable crops on a

  12. Biodegradación de DDT por dos cepas nativas de hongos de la podredumbre blanca

    Directory of Open Access Journals (Sweden)

    Osmel Domínguez

    2010-01-01

    Trametes maxima MUCL 44155, las cuales producen elevados niveles de las enzimas lacasa y MnP en el medio Kimura suplementado con diferentes concentraciones de DDT (5, 10 and 15 mg.L-1. El hecho de que nuestras cepas excreten estas enzimas es un resultado importante dado que las mismas presentan una estrecha relación con la degradación de DDT. La cromatografía gaseosa realizada a las muestras de DDT tratadas con ambas cepas confirmó la transformación del DDT y la aparición de productos de degradación en el tratamiento con la cepa B-18.

  13. Evaluación en modelos animales de cepas vivas atenuadas de vibrio cholerae O139

    Directory of Open Access Journals (Sweden)

    Talena Ledón

    2010-01-01

    Full Text Available CRC3222 y CRC3241 son mutantes mshA derivados de una cepa salvaje de Vibrio cholerae O139, estos fueron obtenidos mediante una serie de modificaciones genéticas que incluyó la deleción de los genes del fago CTXfi. Dichos clones además están marcados con el gen heterólogo celA, el cual se insertó en el locus de hapA. Estudios previos han demostrado que estas cepas poseen características adecuadas para ser empleadas como vacunas vivas contra cólera; la virulencia y capacidad colonizadora de CRC3222 y CRC3241 fueron estudiadas en el modelo de ratón lactante. En este trabajo se evalúa su desempeño en el modelo de conejo adulto, el cual se utilizó para estudiar el potencial inmunogénico de estas cepas. Luego de la inoculación intraduodenal con una simple dosis de 109 UFC de CRC3222, CRC3241 y sus cepas parentales, se determinó tanto el título de anticuerpos IgG anti-LPS O139, como el de anticuerpos con actividad vibriocida presentes en el suero de los conejos inmunizados. Estos estudios indicaron que ambas cepas generaron una buena respuesta inmune, ya que se detectó un incremento de más de cuatro veces en los títulos de anticuerpos bactericidas de todos los conejos vacunados, con relación al suero pre-inmune. No se detectaron diferencias significativas en la respuesta de los mutantes mshA, con relación a sus cepas parentales, independientemente de su fenotipo de motilidad. Este experimento demostró que CRC3222 y CRC3241 son potenciales candidatos vacunales contra la infección con Vibrio cholerae O139.

  14. Configuration of nucleolarDNA in situ in nucleolus ofAllium cepa cells

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The location and configuration of nucleolar DNA have not beendetermined for a long time. In this paper, we have observed the nucleolar ultrastructure and the character of nucleolar DNA in Allium cepa cells by conventional electron microscopy and the cytochemical NAMA-Ur DNA specific staining method. Furthermore, we have properly improved the NAMA-Ur method so as to analyze the location and configuration of nucleolar DNA in situ. Our results indicated that the nucleolar DNA in Allium cepa cells is mainly located at the border between fibrillar centers and dense fibrillar component, especially distributed in the configuration of encircling the fibrillar centers.

  15. The cepa project: a new model for community-based program planning.

    Science.gov (United States)

    Buchanan, D; Apostol, E; Balfour, D; Claudio, C; Marinoff, J; O'Hare, N; Rodriguez, M; Santiago, C

    1993-01-01

    The article describes a new model of community-based program planning developed by the Centro de Educacion, Prevencion y Accion (CEPA) project, an HIV prevention program for Puerto Ricans located in Holyoke, Massachusetts. Based on models of critical thinking, empowerment and participatory education, the basic philosophy of the CEPA project is to narrow the gap between program developers and program recipients to the greatest extent possible. The article discusses the successes and challenges encountered in approaching this ideal. The article concludes with recommendations for public health professionals considering the use of community-based approaches to address public health issues. PMID:20841236

  16. Synthesis and characterization of Allium cepa L. as photosensitizer of dye-sensitized solar cell

    Science.gov (United States)

    Sutikno, Afrian, Noverdi; Supriadi, Putra, Ngurah Made Dharma

    2016-04-01

    The synthesis and characterization of Allium cepa L. used as natural pigment for natural dye sensitizer of solar cell has successfully done and anthocyanin is extracted. Anthocynin is color pigment of plant which has characteristic absorption spectrum of photon and excites electrons up to pigment molecules. As the anthocyanin absorbed light increases the excited electrons increase as well. The generated current also increases and it leads to the efficiency increase. The energy conversion efficiency of the cells sensitized with dye of Allium cepa L. was 3,045 x 10-4%. A simple technique was taken to fabricate dye sensitizer solar cell is spincoating.

  17. Indicadores fisiológicos de la respuesta al estrés en cepas Saccharomyces cerevisiae alcholeras

    Directory of Open Access Journals (Sweden)

    Roxana García

    2009-01-01

    Full Text Available El fenómeno de tolerancia cruzada en levaduras se ha propuesto como indicador fisiológico útil en estudios de selección de cepas S. cerevisiae para la obtención de etanol. Se evalúa para cinco cepas de esta especie la relación entre resistencia a H2O2 3,2 M y a presiones hidrostáticas de 200 MPa durante 30 minutos y la actividad enzimática alcohol deshidrogenasa (ADH en presencia de etanol y glucosa. Solo el mutante auxótrofo XA3-1 no muestra un crecimiento apreciable ante el estrés oxidativo. Su cepa salvaje A3 es la única capaz de crecer hasta la mayor dilución a altas presiones hidrostáticas. Las cepas CM y 373 muestran patrones similares de actividad ADH en presencia de glucosa o etanol, mientras que las cepas A3 y su mutante presentan niveles de ADH superiores en presencia de 5% (v/v de etanol. Los resultados indican una estrecha vinculación entre la resistencia a estreses no necesariamente propios de la fermentación alcohólica y el comportamiento fermentativo en cepas S. cerevisiae, lo cual abre la posibilidad de emplear estos criterios para estudios de selección de cepas alcoholeras dirigidos a futuras estrategias de mejoramiento genético.

  18. Corn gluten meal as a preemergence herbicide for spring-transplanted onions (Allium cepa L.)

    Science.gov (United States)

    Onions (Allium cepa L.) are a potential alternative crop for Oklahoma and northeast Texas. Corn gluten meal is a certified organic material used for preemergence or preplant incorporated weed control. In 2002 and 2003 field research was conducted in southeast Oklahoma (Lane, OK) to determine the ...

  19. Fusarium oxysporum f.sp. cepae dynamics: in-plant multiplication and crop sequence simulations

    NARCIS (Netherlands)

    Leoni, C.; Vries, de M.; Braak, ter C.J.F.; Bruggen, van A.H.C.; Rossing, W.A.H.

    2013-01-01

    To reduce Fusarium Basal Rot caused by Fusarium oxysporum f.sp. cepae (Foc) through crop rotation, plant species should be selected based on Foc multiplication in their roots. Foc multiplication rates in 13 plant species were tested in a greenhouse. All plant species enabled Foc multiplication. The

  20. Screening for resistance to the beet armyworm (Spodoptera exigua) in Allium cepa and its wild relatives

    NARCIS (Netherlands)

    Zheng, S.J.; Henken, B.; Sofiari, E.; Wietsma, W.A.; Jacobsen, E.; Krens, F.A.; Kik, C.

    2000-01-01

    The beet armyworm (Spodoptera exigua Hübner) is the most important pest in tropical Allium cultivations. All shallot ( Allium cepa L. group Aggregatum) cultivars are susceptible to this pest. Therefore accessions from three wild Allium species, namely A. galanthum Kar. et Kir., A. fistulosum L. and

  1. Factors influencing induction, propagation and regeneration of mature zygotic embryo-derived callus from Allium cepa.

    NARCIS (Netherlands)

    Zheng, S.; Henken, B.; Sofiari, E.; Jacobsen, E.; Krens, F.A.; Kik, C.

    1998-01-01

    A systematic study on the effects of subspecies, cultivar, basal medium, sucrose concentration and 2,4-dichlorophenoxyacetic acid concentration on callus induction, propagation and subsequent plant regeneration in Allium cepa has been carried out. Mature zygotic embryos from two onion (cvs. Sturon a

  2. Preliminary Identification of Entomopathogenic Nematodes (Heterorhabditis bacteriophora strain NileKe) and Its Symbiotic Bacteria in Xinjiang%新疆嗜菌异小杆线虫及其共生细菌的初步鉴定研究

    Institute of Scientific and Technical Information of China (English)

    詹发强; 布卡欧尔娜; 侯敏; 杨蓉; 龙宣杞

    2015-01-01

    【目的】分离获得新疆地区的昆虫病原线虫及其共生细菌,确定其种属及共生细菌的分类地位,为新疆利用昆虫病原线虫进行生物防治害虫提供新的选择和奠定基础。【方法】采用黄粉甲( Tenebrio molitor)幼虫为诱导昆虫,采用 Whitetrap 法收集侵染期线虫,通过致死的昆虫血腔和侵染期线虫直接分离共生细菌,利用18S rRNA 与形态鉴定初步确定昆虫病原线虫的种属,利用16S rRNA 与形态初步确定其共生细菌的分类地位。【结果】从新疆伊犁州尼勒克县一山区牧场林带土壤中分离出一种能够有效致死黄粉甲幼虫的昆虫病原线虫,经初步鉴定其属于异小杆属线虫,与嗜菌异小杆线虫进化距离最近,初步命名为嗜菌异小杆线虫尼勒克品系(Heterorhabditis bacteriophora strain Nileke);分离出其共生细菌,初步鉴定为 Photorhabdus luminescens(NLK—1),但无荧光。【结论】在新疆本土成功分离出一种异小杆属昆虫病原线虫及其共生细菌,初步确定了其种属,为在新疆本土开展以昆虫病原线虫为主的生物防治害虫提供了新的选择及途径,为开展本地区更广泛的分离筛选奠定了基础。%Objective]To obtain a local entomopathogenic nematodes and their symbiotic bacteria,deter_mine their species and taxonomic status,provide new options and lay the foundation of using our region′s ento_mopathogenic nematodes to control pests in future.[Method] Using Tenebrio molitor larve to induce ento_mopathogenic nematodes,adopting the method of whitetrap to collect infective juveniles.Symbiotic bacteria i_solated directly through infective juveniles or the blood chamber of Tenebrio molitor larve which were infected by entomopathogenic nematodes,using 18S rRNA and morphological to identify the species of nematodes ini_tially,16S rRNA and morphological to identify the species of symbiotic bacteria initially

  3. Determinación de la presencia de genes cry en cepas nativas de Bacillus thuringiensis

    Directory of Open Access Journals (Sweden)

    Chaparro Giraldo Luis Alejandro

    2004-12-01

    Full Text Available A partir de dos tipos de muestras, suelo asociado a cultivos de papa (Solanum tuberosum y polvo asociado a sitios de almacenamiento de granos (cereales colectado en las centrales de Corabastos y Paloquemao en Bogotá, se aislaron 88 cepas nativas de Bacillus thuringiensis bacilo
    grampositivo patógeno de insectos plaga de cultivos agrícolas. De las 88 cepas obtenidas 57 de ellas se escogieron para separarlas posteriormente mediante subcultivos en virtud a sus características fenotípicas al interior de la colonia llevando esto a obtener un número de 145 cepas nuevas para un total de 176 cepas de B. thuringiensis caracterizadas  morfológicamente y por su patrón de formas de las ICPs mediante microscopía de contraste de fases, y de las proteínas Cry arrojado por los perfiles de SDS-PAGE; en el total de cepas hubo presencia predominante de ICPs con forma romboide acompañadas por al menos otras dos formas distintas, y mostraron perfiles electroforéticos de proteínas de peso molecular entre el rango de 130, 116 y 60 kDa. Del total de cepas B. thuringiensis nativas aisladas en este estudio, 59 (30 de suelos y 29 de polvo fueron analizadas mediante la técnica PCR, encontrando que 100% de ellas son portadoras de alguno de los seis tipos de genes cry1 estudiados cry1Aa5 (71,2%, cry1Ab9 (66,1%, cry1Ac5 (45,8%, cry1Ba1 (39%, cry1Ca3 (49,1%, y cry1Da1 (71,2%; adicionalmente se observó la presencia de productos génicos inespecíficos, posiblemente nuevos, amplificados por la PCR y relacionados con los genes cry1C (55,9%, cry1B (30,5% y otros genes cry1 no estudiados por este método en al menos el 50% de las cepas estudiadas. De acuerdo con estos resultados se estableció un total de 19 genotipos diferentes según los genes cry1 estudiados, presentados por las cepas nativas en estudio determinando que estos son diferentes en composición genética según la fuente de procedencia del aislamiento, permitiendo establecer estrecha correlaci

  4. Resistencia a penicilina G y oxacilina, de cepas de Staphylococcus aureus aisladas de mastitis bovina subclínica

    OpenAIRE

    Michael Zschöck; Amr El-Sayed; Nawara Eissa; Christoph Lämmler; Hugo Castañeda-Vazquez

    2011-01-01

    De 530 diferentes cepas de S. aureus aisladas de casos de mastitis subclínica bovina, se seleccionaron 68 cepas de S. aureus procedentes de Alemania (n = 26), Indonesia (n = 16), México (n = 16) y Brasil (n = 10), para estudiarlas en la presente investigación. Las cepas fueron analizadas fenotípica y genotípicamente para observar su resistencia a penicilina G y oxacilina. Para una identificación inicial se utilizó el sistema Api 32 Staph y la prueba de coagulasa. El resultado se confirmó por ...

  5. Efectividad de la vacuna VA-MENGOC-BC® contra cepas heterólogas de meningococo B

    Directory of Open Access Journals (Sweden)

    Rolando Ochoa-Azze

    2016-08-01

    Full Text Available La efectividad de las vacunas de vesículas de membrana externa de Neisseria meningitidis serogrupo B ha sido cuestionada por algunos investigadores, limitándola a la cepa vacunal. VA-MENGOC-BC® es una vacuna antimeningocócica basada en dicha tecnología. Presentamos un metaanálisis de estudios realizados en diferentes contextos epidemiológicos, evaluando su efectividad contra cepas heterólogas de meningococo B en varios grupos de edades. Se demuestra que la vacuna es efectiva contra cepas homólogas, heterólogas y de diferentes complejos clonales.

  6. Identificación de la cepa vacunal Brucella abortus S19 en muestras de leche de vaca

    OpenAIRE

    Luary Carolina Martínez Chavarría; Antonio Verdugo Rodríguez; Rigoberto Hernández Castro

    2006-01-01

    La brucelosis es una enfermedad infectocontagiosa de origen bacteriano que afecta tanto al humano como a diferentes especies animales domésticas y silvestres. En la década pasada, la vacuna que se usaba ampliamente en los bovinos era la cepa vacunal B. abortus S19, que tiene una deleción en dos de los genes del operón ery que participa en el catabolismo del eritritol. En México, desde 1997 se aprobó la cepa B. abortus RB51 como vacuna para el ganado. Esta cepa presenta una secuencia de inserc...

  7. Marcadores fenotípicos de atenuación en cepas de virus Junín recuperadas de individuos vacunados con la cepa Junín Candid#1

    Directory of Open Access Journals (Sweden)

    Graciela S. Gamboa

    2013-08-01

    Full Text Available La Fiebre Hemorrágica Argentina es una enfermedad producida por el virus Junín. Para la prevención de esta enfermedad se obtuvo una vacuna efectiva denominada Candid#1. Durante un ensayo clínico realizado en el INEVH, dos cepas de virus Junín fueron aisladas de sangre periférica de dos voluntarios mediante co-cultivo de células mononucleares. El objetivo de este trabajo fue comparar las características fenotípicas de atenuación de esas dos cepas recuperadas de humanos con las de la vacuna Candid#1 utilizando los indicadores de atenuación desarrollados por Contigiani y Sabattini en 1977. A tal fin se midieron los índices de letalidad, infección y protección en cobayos y ratones de diferentes edades. Las tres cepas investigadas resultaron letales para ratones recién nacidos pero no para ratones de 10 a 12 días, ratones adultos ni cobayos, aun a la más baja dilución inoculada. Los cobayos inoculados con las cepas recuperadas de humanos y con la cepa Candid#1 no presentaron síntomas de enfermedad y mostraron estar protegidos cuando fueron desafiados con una cepa patógena. Los índices de infección y de protección hallados indican que estas cepas poseen elevada capacidad infectante y protectora en las especies animales aquí estudiadas. Estos resultados demuestran que las cepas de virus Junín aisladas de voluntarios inmunizados con Candid#1 mantienen el mismo fenotipo atenuado de la vacuna Candid#1 después de un pasaje por humanos.

  8. Potential therapeutic effect of Allium cepa L. and quercetin in a murine model of Blomia tropicalis induced asthma

    OpenAIRE

    Oliveira, Tatiane Teixeira; Campos, Keina Maciele; Cerqueira-Lima, Ana Tereza; Cana Brasil Carneiro, Tamires; da Silva Velozo, Eudes; Ribeiro Melo, Ingrid Christie Alexandrino; Figueiredo, Eugênia Abrantes; de Jesus Oliveira, Eduardo; de Vasconcelos, Darizy Flávia Silva Amorim; Pontes-de-Carvalho, Lain Carlos; Alcântara-Neves, Neuza Maria; Figueiredo, Camila Alexandrina

    2015-01-01

    Background Asthma is an inflammatory condition characterized by airway hyperresponsiveness and chronic inflammation. The resolution of inflammation is an essential process to treat this condition. In this study we investigated the effect of Allium cepa L. extract (AcE) and quercetin (Qt) on cytokine and on smooth muscle contraction in vitro and its therapeutic potential in a murine model of asthma. Methods AcE was obtained by maceration of Allium cepa L. and it was standardized in terms of qu...

  9. GC-MS Investigation of Essential oil and antioxidant activity of Egyptian White Onion (Allium cepa L.)

    OpenAIRE

    Eman Ahmed El-Wakil; Mortada Mohamed El-Sayed; Ezzat El-Sayed Abdel-Lateef

    2015-01-01

    Objectives: This study carried out to investigate the chemical constituents of white onion (Allium cepa L.) essential oil as well as evaluate the antioxidant activities, total phenolic and total flavonoid contents of their different extracts. Methods: The Essential oil of white onion (Allium cepa L.) bulbs were extracted by hydro distillation method and analysed by gas chromatography coupled with mass spectrometry (GC–MS) to determine the chemical composition of the volatile compounds. The an...

  10. Evaluation of Green Manure Amendments for the Management of Fusarium Basal Rot (Fusarium oxysporum f.sp. cepae) on Shallot

    OpenAIRE

    Assefa Sintayehu; Seid Ahmed; Chemeda Fininsa; Sakhuja, P. K.

    2014-01-01

    Shallot (Allium cepa L. var. ascalonicum) is the most traditional vegetable crop in Ethiopia. Shallot is susceptible to a number of diseases that reduce yield and quality, among which fusarium basal rot (FBR) caused by Fusarium oxysporum f.sp. cepae (Foc) is one of the most important yield limiting factors in Ethiopia. The present study was designed to evaluate the effectiveness of Brassica crops for the management of shallot FBR on shallot. The experiments were carried out at Debre Zeit Agri...

  11. Prevalência de sorotipos e resistência antimicrobiana de cepas invasivas do Streptococcus pneumoniae

    Directory of Open Access Journals (Sweden)

    Mantese Orlando C.

    2003-01-01

    Full Text Available OBJETIVO: Avaliar o perfil de sorotipos e a susceptibilidade aos antimicrobianos de cepas de Streptococcus pneumoniae obtidas em espécimes clínicos de pacientes com doença invasiva, bem como suas implicações na formulação de vacinas pneumocócicas. MÉTODOS: Cepas de pneumococo isoladas no Laboratório de Análises Clínicas do Hospital de Clínicas da Universidade Federal de Uberlândia a partir de amostras clínicas de pacientes com doença invasiva foram identificadas e enviadas ao Instituto Adolfo Lutz em São Paulo para confirmação da identificação, sorotipagem e determinação da susceptibilidade aos antimicrobianos. RESULTADOS: De abril de 1999 a março de 2003, foram isoladas 148 cepas invasivas de pneumococo, sendo 84 (56,7% provenientes de pacientes do sexo masculino. A idade variou de um dia a 88,83 anos, com média de 21,33+25,82 anos e mediana de 4,42 anos. Os diagnósticos clínicos mais comuns foram pneumonia (91 casos; 61,4%, meningite (32 casos; 21,6% e bacteremia sem foco evidente (15 casos; 10,1%. As principais fontes de recuperação foram sangue (76 amostras; 51,3%, líquido pleural (39; 26,3% e liquor (30; 20,2%. No total, foram identificados 23 diferentes sorotipos entre 143 amostras testadas, sendo os mais comuns os seguintes: 14, 3, 1, 5, 6A, 6B e 18C. Dentre 30 (20,2% cepas oxacilina-resistentes, 23 (15,5% confirmaram a resistência à penicilina (12,8% com nível intermediário e 2,7%, com nível pleno, que esteve restrita aos sorotipos 14, 23F, 19A e 6B, predominando em indivíduos com até dois anos de idade (p = 0,0008. Foi detectada susceptibilidade diminuída ao cotrimoxazol (63,4%, à eritromicina (8,3%, à clindamicina (8,7% e à ofloxacina (0,8%. A resistência à cefotaxima foi detectada em três das 30 cepas testadas (2% das 148, todas elas com resistência confirmada à penicilina. Não foi observada resistência a cloranfenicol, rifampicina ou vancomicina. CONCLUSÕES: A resistência

  12. Variabilidad genética en cepas de Sporothrix schenckii aisladas en Abancay, Perú

    Directory of Open Access Journals (Sweden)

    Susan Holechek

    2004-04-01

    Full Text Available Objetivo: Identificar los genotipos de S. schenckii que circulan en 2 distritos de la provincia de Abancay, Perú. Material y Métodos: Se evaluaron 17 cepas procedentes de pacientes con lesiones linfocutáneas y lesión cutánea fija mediante la técnica del ADN Polimorfo Amplificado Aleatorio - Reacción en Cadena de la Polimerasa (RAPD - PCR con el cebador GTG 5 (GTG GTG GTG GTG GTG. Resultados: Identificamos 6 genotipos, siendo el genotipo I el predominante en las áreas de estudio. No se logró asociar los genotipos obtenidos con caracteres clínicos y geográficos. Conclusiones: Nuestros resultados evidencian que existe biodiversidad genética entre las cepas de S. schenckii que circulan en ambas zonas.

  13. Cytotoxic Effects of (5 Medicinal Plants on Mitosis in Allium cepa Root Tips

    Directory of Open Access Journals (Sweden)

    I.J. Udo

    2014-03-01

    Full Text Available The study was conducted to investigate the effects that plant extracts from 5 medicinal plants may have on mitosis in Allium cepa. Root of A .cepa were immersed in alcoholic extracts at the concentrations of 0, 25, 50, 75 and 100 mg/mL, respectively for each of the following plants: Gnetum africanum Welw., Lasianther aafricana P. Beauv, Ocimum gratissimum Linn., Telfairia occidentalis Hook F. and Vernonia amygdalina Del. Leafy vegetable which are commonly used in herbal medicine. Results obtained show that the various concentrations of the extracts from test plants had toxic effects on the cells, which caused significant reduction (p<0.05 in the mitotic index when compared with the control. Other effects were prophase inhibition, the delay of mitosis and nuclear lesion. The cytotoxic effect makes a case for a precaution in the use of the leafy extracts in herbal medicine practice.

  14. The impact of atmospheric H2S on growth and sulfur metabolism of Allium cepa L.

    NARCIS (Netherlands)

    Durenkamp, M; De Kok, LJ

    2002-01-01

    The impact of atmospheric H2S deposition on growth and sulfur metabolism has been studied in onion (Allium cepa L.). The H2S Uptake followed saturation kinetics with respect to the H2S concentration. The maximum H2S uptake rate (JH(2)S(max)) was approx. 1 mumol g(-1) FW h(-1) and the KH2S (H2S conce

  15. Suscetibilidade de biomphalaria glabrata, B. straminea e B. tenagophila a diferentes cepas de schistosoma mansoni

    Directory of Open Access Journals (Sweden)

    Luiz Candido de Souza Dias

    1987-08-01

    Full Text Available Em condições experimentais foi estudada a suscetibilidade de Biomphalaria glabrata, B. straminea e B. tenagophila a quatro linhagens humanas (MAP, PTH, UPH, e OuH e duas de roedores silvestres (PTR e VPR do Schistosoma mansoni. Grupos de 50 moluscos foram expostos individualmente a 10 miracídios e observados durante 70 dias. Avaliou-se a suscetibilidade dos moluscos ao parasito por meio da % de animais com esporocistos, % de moluscos que eliminavam cercárias e mortalidade conjunta dos animais expostos e infectados. Exemplares de B. glabrata mineira infectaram-se com cepa simpátrica (MAP e com 5 alopátricas do Estado de São Paulo (PTH, VPH, OuH, PTR e VPR. B. glabrata paulista mostrou altas taxas de infecção com as cepas MAP, VPR e OuH do trematódeo. Quatro % dos exemplares B. straminea de São Paulo eliminavam cercárias de cepas simpátricas; com cepa mineira apenas 4% apresentaram esporocistos na vigência de 20 miracídios por molusco; as menores taxas de mortalidade foram registradas com essa espécie de molusco, não sendo maior do que 20%. B. tenagophila paulista foi suscetível apenas às linhagens simpáticas sendo 6% a maior taxa de moluscos que eliminaram cercárias. Os resultados indicam que os movimentos populacionais humanos dentro do território paulista e para fora dele são importantes na disseminação da esquistossomose mansônica.

  16. Efectos del gas ozono sobre cepas de Fusarium verticillioides y F. proliferatum productoras de fumonisinas

    Directory of Open Access Journals (Sweden)

    Laura Frisón

    2014-07-01

    Full Text Available Las fumonisinas son producidas por especies de Fusarium, esencialmente por Fusarium verticillioides y F. proliferatum que se encuentran como contaminantes naturales en maíz y subproductos de maíz. Su consumo, se asocia con ciertas enfermedades en animales y humanos. La industria alimentaria apunta sus investigaciones al desarrollo de nuevas tecnologías y la aplicación de gas ozono, dado su elevado poder germicida y su descomposición espontánea a oxígeno, se ha convertido en un agente potencial para garantizar la seguridad microbiológica y la calidad de los alimentos. Debido a la importancia del consumo de maíz en Argentina y a la contaminación de este grano por cepas productoras de fumonisinas, se estudió la posibilidad de detoxificar maíz contaminado con esta toxina con gas ozono. Se aislaron cepas de Fusarium verticillioides y F. proliferatum de granos de maíz y de silaje. Se estudió la capacidad de producción de toxina de dichas cepas. La cuantificación de esta toxina se realizó mediante ensayo por inmunoabsorción ligado a enzimas (ELISA con el kit para fumonisinas RIDASCREEN®FAST Fumonisin siguiendo las instrucciones del fabricante. Se utilizó gas ozono a concentraciones de: 4500, 7500 y 25000 ppmv, por tiempos de exposición de 10 y 20 minutos. Todas las cepas de Fusarium estudiadas fueron buenas productoras de fumonisinas. A las concentraciones y tiempos evaluados, no se observó la eliminación o disminución de la concentración de toxina. Prevenir la contaminación con estos mohos es la mejor solución para el problema de las micotoxinas, debido a que una vez producida la toxina es difícil de erradicar.

  17. Efectos del gas ozono sobre cepas de Fusarium verticillioides y F. proliferatum productoras de fumonisinas

    Directory of Open Access Journals (Sweden)

    Laura Frisón

    2014-06-01

    Full Text Available Las fumonisinas son producidas por especies de Fusarium, esencialmente por Fusarium verticillioides y F. proliferatum que se encuentran como contaminantes naturales en maíz y subproductos de maíz. Su consumo, se asocia con ciertas enfermedades en animales y humanos. La industria alimentaria apunta sus investigaciones al desarrollo de nuevas tecnologías y la aplicación de gas ozono, dado su elevado poder germicida y su descomposición espontánea a oxígeno, se ha convertido en un agente potencial para garantizar la seguridad microbiológica y la calidad de los alimentos. Debido a la importancia del consumo de maíz en Argentina y a la contaminación de este grano por cepas productoras de fumonisinas, se estudió la posibilidad de detoxificar maíz contaminado con esta toxina con gas ozono. Se aislaron cepas de Fusarium verticillioides y F. proliferatum de granos de maíz y de silaje. Se estudió la capacidad de producción de toxina de dichas cepas. La cuantificación de esta toxina se realizó mediante ensayo por inmunoabsorción ligado a enzimas (ELISA con el kit para fumonisinas RIDASCREEN®FAST Fumonisin siguiendo las instrucciones del fabricante. Se utilizó gas ozono a concentraciones de: 4500, 7500 y 25000 ppmv, por tiempos de exposición de 10 y 20 minutos. Todas las cepas de Fusariumestudiadas fueron buenas productoras de fumonisinas. A las concentraciones y tiempos evaluados, no se observó la eliminación o disminución de la concentración de toxina. Prevenir la contaminación con estos mohos es la mejor solución para el problema de las micotoxinas, debido a que una vez producida la toxina es difícil de erradicar.

  18. El consumo de oxigeno de cepas de uta y espundia (Leishmania) con monosacáridos

    OpenAIRE

    Margarita Aurazo R.; Inés Gárate C.; César Náquira V

    2014-01-01

    Se ha realizado un estudio comparativo de la respiración, y la acción de los monosacáridos (glucosa, fructosa, galactosa y manosa) sobre el consumo de oxigeno entre dos cepas de Leishmania provenientes de casos clínicos de leishmaniosis cutánea pura (uta) y de leishmaniosis cutáneo-mucosa (espundia) del Perú.

  19. Modulating effect of Allium cepa on kidney apoptosis caused by Toxoplasma gondii

    OpenAIRE

    Yaghub gharadaghi; Saeedeh Shojaee; Arash Khaki; Amir Hatef; Hamid Reza Ahmadi Ashtiani; Hossin Rastegar; Fatemeh Fathiazad

    2012-01-01

    Purpose: Toxoplasma gondii is a widespread protozoan parasite that infects a broad range of warm blooded animals as well as humans. The present study was investigated to evaluate the effects of allium cepa on renal failur in male rats which experimentally infected by Toxoplasma gondii, RH strain. Methods: Wistar male rat (n=40) were allocated into four groups, group one that received tachyzoites of T. gondii (ip) (n=10), group two that received tachyzoites of T. gondii (ip), plus fresh onion ...

  20. Content of total polyphenols and antioxidant activity in selected varieties of onion (Allium cepa L.)

    OpenAIRE

    Petra Kavalcová; Judita Bystrická; Pavol Trebichalský; Miriama Kopernická; Miroslava Hrstková; Marianna Lenková

    2015-01-01

    Onion (Allium cepa L.) is one of the most important vegetable crops widely consumed in the world. The bulb onion is grown as fresh shoots and as bulbs for consuming uncooked, cooked, and pickled or production of seed and sets. They can be eaten raw, boiled, steamed and roasted. Onion has high nutritional value. Onions are a good source of vitamins, minerals and major component like polyphenols, flavonoids, fructooligosaccharides, thiosulfinates and other sulfur compounds. Polyphen...

  1. POTASSIUM AND ITS EFFECT ON THE CONTENT OF POLYPHENOLS IN ONION (ALLIUM CEPA L.)

    OpenAIRE

    Petra Kavalcová; Judita Bystrická; Tomáš Tóth; Beáta Volnová; Miriama Kopernická; Ľuboš Harangozo

    2015-01-01

    Onion (Allium cepa L.) is rich of chemoprotective compounds as polyphenols, flavonoids, anthocyanins, vitamins, sulphur compounds which have potential beneficial properties for human health. Potassium as important mineral abundant plays many vital roles in plant nutrition (reduces respiration, activates enzyme). In generally, potassium increases crop yield and improves quality of onion bulbs. The objectives of this work were to compare and evaluate the impact of potassium on the content of to...

  2. Strip Tillage and Early-Season Broadleaf Weed Control in Seeded Onion (Allium cepa)

    OpenAIRE

    Sarah Gegner-Kazmierczak; Harlene Hatterman-Valenti

    2016-01-01

    Field experiments were conducted in 2007 and 2008 near Oakes, North Dakota (ND), USA, to evaluate if strip tillage could be incorporated into a production system of seeded onion (Allium cepa) to eliminate the standard use of a barley (Hordeum vulgare) companion crop with conventional, full width tillage, yet support common early-season weed control programs. A split-factor design was used with tillage (conventional and strip tillage) as the main plot and herbicide treatments (bromoxynil, DCPA...

  3. Chromosomal and Nuclear Alterations in Root Tip Cells of Allium Cepa L. Induced by Alprazolam

    Science.gov (United States)

    Nefic, Hilada; Musanovic, Jasmin; Metovic, Azra; Kurteshi, Kemajl

    2013-01-01

    ABSTRACT Introduction: Alprazolam is a triazolobenzodiazepine used in panic disorders and other anxiety states. Target organ of Alprazolam is CNS, causing depression of respiration and consciousness. Aim: This study aimed to estimate the genotoxic potential of Alprazolam using Allium cepa test. Methods: Allium cepa is one of the most suitable plants for detecting different types of xenobiotics. The test enables the assessment of different genetic endpoints making possible damage to the DNA of humans to be predicted. Results: Alprazolam induced chromosomal (anaphase bridges, breaks, lagging and stickiness, abnormal spiralisation, multipolarity and polyploidy) and cytological aberrations, especially nuclear alterations (nuclear buds, fragmented nucleus and apoptotic bodies, cells without nucleus, binucleated and micronucleated cells), morphological alterations in shape and size of cells, spindle disturbance and polar deviation in root tip meristem cells of Allium cepa at all tested concentrations. Alprazolam also caused significant inhibition of mitotic index in these cells. Conclusion: These changes in cells are indicators of genotoxic potential of Alprazolam suggesting a need for further in vitro studies on animal and human lymphocytes as well as in vivo studies. PMID:25568504

  4. Isolation of lactic acid bacteria from Allium cepa var. aggregatum and study of their probiotic properties

    Directory of Open Access Journals (Sweden)

    Nannu Shafakatullah

    2015-04-01

    Full Text Available The shallot (Allium cepa var. aggregatum or the A. cepa Aggregatum Group is a botanical variety of the species Allium cepa, to which the multiplier onion also belongs. Shallots are called "small onions" in South India and are used extensively in cooking. The scientific use of shallots as a source of Lactic Acid Bacteria (LAB has not yet been examined. Indigenous knowledge revealed shallots as a good health source. An attempt has been made to find out the possibilities of LAB in fresh shallots. Four isolates were identified on the basis of their morphological, cultural, physiological and biochemical tests and their probiotic properties were evaluated. These isolates were screened for resistance against bile salt, gastric juice, intestinal juice, different NaCl concentrations, acidic pH, ability to inhibit pathogens, antibiotic resistance, adherence capacity as well as survival under different storage temperatures. Isolated strains Bacillus coagulans (Lactobacillus sporogenes, Lactobacillus brevis, Lactobacillus delbrueckii subsp. bulgaricus and Lactococcus lactis showed satisfactory probiotic potentials.

  5. Phytosteroids from tissue culture of Allium cepa L. and Trachyspermum ammi S prague.

    Directory of Open Access Journals (Sweden)

    Pratibha Chaturvedi

    2013-03-01

    Full Text Available Production of secondary metabolites by cultured cells provides a particularly important benefit to manipulate and improve the production of desired compounds; thus biotechnological approaches to increase the concentrations of the metabolites are discussed. Present study deals with the production, isolation and identification of phytosterols from tissue culture of Allium cepa and from plant parts and tissue culture of Trachyspermum ammi. Steroidal analysis of plant parts showed the maximum amount of stigmasterol (0.240 mg/gdw which was comparatively little less than that of the amount of β- sitosterol (0.295 mg/gdw in the seeds of T. ammi . The maximum amount of stigmasterol was present in four weeks old tissue of T. ammi (0.249 mg/gdw whereas the highest content of β- sitosterol was observed in six weeks old tissue of A. cepa (0.315 mg/gdw However, lanosterol, was present only in the tissue of A. cepa which was maximum in six weeks old tissue (0.039 mg/gdw.

  6. Plasmidotipia y evaluación in vitro de la virulencia de cepas de Salmonella enteritidis de origen aviar

    Directory of Open Access Journals (Sweden)

    Rubén Darío Toro

    2000-02-01

    Full Text Available Con el fin de caracterizar a nivel biológico y molecular cepas de Salmonella entérica, subespecie entérica serotipo Enteritidis (Salmonella enteritidis se obtuvieron y confirmaron bioquímica y serológicamente treinta cepas aisladas de aves clínicamente sanas. Las cepas fueron evaluadas mediante plasmidotipia y determinación de virulencia in vitro evaluando susceptibilidad antimicrobiana, actividad hemaglutinante manosa resistente y manosa sensible como indicativo de la presencia de adhesinas fimbriales y capacidad de sobrevivencia en el interior de macrófagos. La extracción de plásmidos se realizó por la técnica de lisis alcalina. Se obtuvieron perfiles de restricción con las enzimas PstI y SmaI. La susceptibilidad antimicrobiana se determinó por la prueba de difusión de disco en agar. La actividad hemaglutinante en presencia y en ausencia de manosa fue evaluada frente a glóbulos rojos de ave, bovino, equino, humano (A+ y ovino. La capacidad de sobrevivencia en el interior de macrófagos se determinó valorando la viabilidad de las cepas 24 horas después de la ingestión por macrófagos de línea de origen murino. Veintinueve cepas (96.6% mostraron un plasmido cuyo tamaño corresponde al plasmido de virulencia asociado a serotipo. Veintisiete cepas (90% mostraron dos o más plasmidos. Perfiles de restricción realizados con las enzimas Pst I y Sma I permitieron establecer una alta asociación entre las cepas. Se determinó resistencia a uno o más antimicrobianos en catorce cepas de S. enteritidis (46.6%, se observó resistencia a oxitetraciclina, sulfatrimetroprim, estreptomicina y cloranfenicol. Ninguna cepa mostró resistencia a gentamicina y kanamicina. Se detectó actividad hemaglutinante manosa sensible como indicativo de adhesinas fimbriales tipo I en once cepas (36.6% de las treinta evaluadas. La totalidad de las cepas sobrevivieron en el interior de macrófagos de línea J774A.1 y fueron viables 24 horas después de la

  7. Proteasas alcalinas de una cepa nativa de Bacillus sp Alcalofílico Proteasas alcalinas de una cepa nativa de Bacillus sp Alcalofílico

    Directory of Open Access Journals (Sweden)

    A. Sáez Vega

    2006-06-01

    Full Text Available Se evaluó el efecto de cuatro fuentes de nitrógeno sobre la actividad enzimática de proteasas alcalinas, secretadas por una cepa nativa de Bacillus sp Alcalofílico, cultivada a diferentes concentraciones de LMF (Licor de Maíz Fermentado. El crecimiento de la cepa no es afectado por los pH de inoculación de 7,0; 8,5 y 9,5; en contraste con la actividad enzimática y producción de proteína verdadera, que tuvieron sus mejores resultados a pH inicial de 8,5. A este pH se evaluaron dos fuentes de nitrógeno orgánico (extracto de levadura y peptona y dos inorgánicos (NH4Cl y NaNO3The effect of four nitrogen sources on the enzymatic activity of alkaline proteases from a wild strain of Alkalophilic Bacillus sp cultivated to different concentrations from CSL (Corn Steep Liquor. was evaluated. The growth of the strain is not affected by pH of inoculation of 7,0, 8,5 and 9,5, in contrast to the enzymatic activity and true protein production, that had their better results to initial pH of 8,5. To this initial pH of 8,5; two organic nitrogen sources (yeast extract and peptone and two inorganic ones were evaluated (NH4Cl and NaNO3. With peptone the best enzymatic activity to a relation appeared to molar C/N between 1 and 2 was found. For the studied interval of % CSL (0,5 to 2% p/v the concentration of the CSL does not affect the enzymatic activity.

  8. Screening and incorporation of rust resistance from Allium cepa into bunching onion (Allium fistulosum) via alien chromosome addition.

    Science.gov (United States)

    Wako, Tadayuki; Yamashita, Ken-ichiro; Tsukazaki, Hikaru; Ohara, Takayoshi; Kojima, Akio; Yaguchi, Shigenori; Shimazaki, Satoshi; Midorikawa, Naoko; Sakai, Takako; Yamauchi, Naoki; Shigyo, Masayoshi

    2015-04-01

    Bunching onion (Allium fistulosum L.; 2n = 16), bulb onion (Allium cepa L. Common onion group), and shallot (Allium cepa L. Aggregatum group) cultivars were inoculated with rust fungus, Puccinia allii, isolated from bunching onion. Bulb onions and shallots are highly resistant to rust, suggesting they would serve as useful resources for breeding rust resistant bunching onions. To identify the A. cepa chromosome(s) related to rust resistance, a complete set of eight A. fistulosum - shallot monosomic alien addition lines (MAALs) were inoculated with P. allii. At the seedling stage, FF+1A showed a high level of resistance in controlled-environment experiments, suggesting that the genes related to rust resistance could be located on shallot chromosome 1A. While MAAL, multi-chromosome addition line, and hypoallotriploid adult plants did not exhibit strong resistance to rust. In contrast to the high resistance of shallot, the addition line FF+1A+5A showed reproducibly high levels of rust resistance.

  9. Caracterización de un pigmento naranja producido por una cepa nativa de bacillus spp.

    Directory of Open Access Journals (Sweden)

    Ana María Gómez-Marín

    2007-01-01

    Full Text Available Considerando la riqueza de especies y variedades microbianas de ciertos países, la búsqueda de cepas nativas con posible potencial biotecnológico y que produzcan compuestos de interés industrial es una forma de impulsar avances científicos, económicos y sociales dentro de las regiones. En este estudio se selecciona e identifica, morfológica y bioquímicamente mediante el juego de reactivos API CHB, una cepa nativa bacteriana del género Bacillus spp., la cual produce un pigmento naranja que es aislado, purificado y caracterizado utilizando diferentes pruebas físicas, químicas y espectrofotométricas. Los resultados indican que la cepa nativa se comporta como un Bacillus subtilis, probablemente el denominado Bacillus globigii según recientes reportes basados en técnicas de identificación molecular. El pigmento naranja producido fue caracterizado, parcialmente, como una melanina, más específicamente una alomelanina, dado su origen microbiano. Debe tenerse en cuenta que la clasificación de un material dentro de esta familia es difícil y ambigua. Se ha denominado melaninas a un conjunto de compuestos biológicos que poseen una serie de características comunes. No existe un método o análisis químico o físico satisfactorio que permita decidir claramente si una sustancia particular pertenece o no a este grupo; sin embargo, existen diferentes pruebas no definitivas, aunque algunas excluyentes, que permiten sospechar si un material bajo estudio puede pertenecer a esta familia de pigmentos. Estas sustancias poseen interesantes propiedades físicas y químicas que las convierte en materiales con potenciales aplicaciones tecnológicas.

  10. Report on the CEPA activities [Consorcio Educativo para la Proteccion Ambiental/Educational Consortium for Environmental Preservation] [Final report of activities from 1998 to 2002

    Energy Technology Data Exchange (ETDEWEB)

    Cruz, Miriam

    2003-02-01

    This report compiles the instances of scientific, educational, and institutional cooperation on environmental issues and other activities in which CEPA was engaged during the past five years, and includes several annual reports and meeting summaries. CEPA is a collaborative international consortium that brings together higher education institutions with governmental agencies, research laboratories, and private sector entities. CEPA's mission is to strengthen the technical, professional, and educational environmental infrastructure in the United States and Latin America. The CEPA program includes curriculum development, student exchange, faculty development, and creation of educational materials, joint research, and other cooperative activities. CEPA's goals are accomplished by actively working with Hispanic-serving institutions of higher education in the United States, in collaboration with institutions of higher education in Latin America and other Consortium members to deliver competitive environmental programs.

  11. EFECTIVIDAD DE CEPAS DE Azotobacter sp. Y Bacillus sp. PARA EL CONTROL DE ESPECIES FÚNGICAS ASOCIADAS A HORTALIZAS

    Directory of Open Access Journals (Sweden)

    Janet Rodríguez Sánchez

    2016-01-01

    Full Text Available Los géneros Azotobacter y Bacillus tienen la potencialidad de fijar nitrógeno atmosférico, solubilizar elementos minerales y producir un grupo de sustancias estimuladoras del crecimiento vegetal. Bacillus se reconoce, además, por su actividad antagonista. Estas razones justifican su selección como principios activos de productos biofertilizantes. La presencia de enfermedades causadas por hongos en los cultivos hortícolas, constituye un problema en la agricultura cubana. El objetivo del presente trabajo fue evaluar la actividad antagonista de cepas de los géneros Azotobacter y Bacillus contra hongos que causan enfermedades a cultivos hortícolas. Para ello se emplearon las especies Fusarium chlamydosporum, Corynespora cassiicola y Cladosporium oxysporum . Todas las cepas pertenecen a las colecciones del INIFAT. Para desarrollar este trabajo se utilizó el Método de “Enfrentamiento de Cultivos Duales”, que permitió seleccionar aquellas que poseen dicha actividad y describir, a la vez, las principales afectaciones que provocan a las estructuras fúngicas. Los resultados arrojaron que dentro de los dos géneros hay cepas que logran inhibir el crecimiento micelial. Dentro de las cepas de Azotobacter cinco resultaron promisorias contra Cladosporium oxysporum, dos responden frente a Fusarium chlamydosporum y una sola resultó efectiva contra Corynespora cassiicola. La actividad mostrada por el género Bacillus fue mayor. En este caso, dos cepas muestran efectividad contra Corynespora casiicola; seis contra Cladosporium oxysporum y ocho contra Fusarium chlamydosporum. Se comprobó que existen cepas de Azotobacter capaces de inhibir a más de una especie fúngica, lo que resulta novedoso por encontrarse poco citada la actividad del género contra patógenos de hortalizas

  12. Propiedades hemaglutinantes de cepas de Escherichia coli aisladas de corderos diarreicos y su relación con su toxicidad

    Directory of Open Access Journals (Sweden)

    J. ZAMORA

    1997-01-01

    Full Text Available Se examinó el contenido intestinal de 107 corderos neonatos muertos con el objeto de aislar cepas de E. coli productoras de toxina termoestable (ST y verotoxina (VT y también comprobar su capacidad hemaglutinante. Se aislaron 84 (78.5% cepas de E. coli, 70 (83.3% de ellas fueron hemaglutinantes de eritrocitos de diversas especies de animales, preferentemente de gallina, la mayoría de las cuales resultaron ser manosa resistentes (HAMR. A su vez, se logró el aislamiento de 18 cepas elaboradoras de ST y de 11 de VT, todas ellas con capacidad hemaglutinante, predominando las de tipo HAMR. Se recomienda hacer la prueba de hemaglutinación y posteriormente pesquisar la estructura antigénica y capacidad enterotóxicas de las cepas aisladas, particularmente cuando se analiza un gran número de cepas, con la finalidad de disminuir los costos de diagnóstico, logrando una información preliminar de cepas presumiblemente patógenasThe intestinal content of 107 neonatal dead lambs was examined in order to isolate producers of thermostable toxin (ST and verotoxin (VT E. coli strains. Besides, the hemagglutinating properties were also tested. Eighty four (78.5% strains of E. coli were isolated, 70 (83.3% of which were hemagglutinating to red blood cells of different animal species, mainly hen; most of them proved mannose resistent (MRHA. Also, 18 strains ST producers and 11 VT producers were isolated, all of them with agglutinating activity; the MRHA type predominating. It is recommended to run the hemagglutination test and secondly to study the antigenic structure and enterotoxic capacity of the isolated strain, particulary when a big number of strains is analized, in order to decrease the diagnostic costs and to obtain preliminary information on presumably, pathogenous strains

  13. Comparison of the ability of fifteen onion (Allium cepa L.) cultivars to accumulate nitrates

    OpenAIRE

    Renata Wojciechowska; Anna Kołton

    2014-01-01

    The aim of a two-year study was to characterise selected Allium cepa L. genotypes with regard to their ability to accumulate nitrates in bulbs as well as to search for a possible relation between NO3- concentration and dry matter content. Fifteen cultivars of edible onion, mostly of long-day genotype with different growing periods, bulb size and skin colour, were taken for the experiment. Seeds of particular cultivars were obtained from the following seed companies: Spójnia Nochowo (‘Labrador...

  14. Tipificación de cepas de Mycobacterium bovis. Revisión

    OpenAIRE

    Rosalinda Acosta-Salinas; Ciro Estrada-Chávez; Feliciano Milián-Suazo

    2009-01-01

    La tuberculosis bovina es una zoonosis que produce grandes pérdidas a la economía de muchos países y constituye un problema de salud pública. Su epidemiología resulta muy compleja debido a que se trata de una bacteria de lento crecimiento, que puede permanecer de forma latente y afectar a diversas especies animales, incluyendo fauna silvestre que funge como reservorio. Por este motivo en todo el mundo existe la necesidad de genotipificar de manera precisa las cepas de M. bovis y rastrear el o...

  15. Screening antibiotics : industrial research by CEPA and Merck in the 1950s

    OpenAIRE

    Santesmases, María Jesús

    2011-01-01

    This article is an account of a screening programme in search of new antibiotics established by CEPA (Compañia Española de Penicilinas y Antibióticos) and Merck in Madrid in 1954. An exploration of the genealogy for such a programme, its narratives and practices, shows that the main inspiration for this programme was the factory system of production, on the one hand, and Selman Waksman’s research agenda on microorganisms of the soil, on the other. In this article, the relationship between ind...

  16. KERUSAKANKROMOSOM BAWANG MERAH (Allium cepaL. AKIBAT PERENDAMAN DENGAN ETIDIUM BROMIDA

    Directory of Open Access Journals (Sweden)

    Eka Fibayani Imaniar

    2014-09-01

    Full Text Available The aim of this research was to identify thedamage of onion’s(AlliumcepaL. chromosomes causedbyethidiumbromide submersion for 6and12hoursat 500ppm. The methodused to study chromosome damage of onionroot tip wassquash technique. The result showed several types of chromosomedamagesuch as the formation of, micronuclei, nuclear buds and chromosome bridges. At 6 hours submersion,the average percentageof chromosomal damage was 2.99 %, while in submersion for 12 hours, the average percentage of chromosomal damage was 6.81 %. Keywords:Ethidium bromide, chromosome damage, Allium cepa L.

  17. Genotoxicity and toxicity evaluations of ECF cellulose bleaching effluents using the Allium cepa L. test.

    Science.gov (United States)

    Roa, O; Yeber, M C; Venegas, W

    2012-08-01

    Toxicity and genotoxicity tests were performed on root cells of Allium cepa in order to evaluate wastewater quality following an ECF cellulose bleaching process. The results revealed a toxic effect of the effluent, with inhibition of meristem growth and generally lower values of metaphase, anaphase and telophase indices at pH 10.5 than pH 7 for all effluent concentrations. The genotoxicity effect was different from the toxic effect given that the micronucleus and the chromosomal aberration tests in anaphase-telophase cells were low over all ranges of the studied effluent concentrations. PMID:22990817

  18. Cytotoxicity of Aloe vera gel extracts on Allium cepa root tip cells

    OpenAIRE

    İLBAŞ, Ali İrfan; GÖNEN, Umut; YILMAZ, Semih; DADANDI, Mehmet Yaşar

    2012-01-01

    Aloe vera L. is a valuable medicinal plant and is currently used in pharmaceutical, cosmetic, and food industries worldwide. In the present study, the effect of various concentrations of Aloe vera leaf gel extracts was investigated on mitotic and phase indexes of Allium cepa L. root tip cells for 24 and 48 h durations. The EC50 value of gel extracts was found to be 20% and was used to determine the experimental concentrations. The results indicated that the mitotic index and root growth rate ...

  19. Riesgo de aparición de cepas Staphylococcus aureus resistente a vancomicina en pacientes hospitalarios de un hospital del Perú, 2008

    Directory of Open Access Journals (Sweden)

    A. Giancarlo Alvarado-Gamarra

    2010-01-01

    Full Text Available Objetivo, Evaluar el riesgo de aparición de cepas de Staphylococcus aureus resistente a vancomicina (VRSA a partir de la interacción de cepas de Staphylococcus aureus resistente a meticilina (MRSA y cepas de Enterococcus resistente a vancomicina (VRE. Diseño, Análisis bivariado de datos de un estudio descriptivo, transversal y retrospectivo. Lugar, Hospital Nacional Hipólito Unanue de Lima-Perú. Participantes, pacientes hospitalizados durante el año 2008. Intervenciones, Formato de registro del laboratorio del hospital. Principales medidas de resultados: Frecuencias relativas y absolutas para variables cualitativos, y medianas para variables cuantitativos, grado de asociación evaluado con odds ratio (OR con un intervalo de confianza al 95%. Resultados, Se encontró un 82,8% de cepas MRSA, mientras que en la Unidad de Terapia Intensiva (UTI se encontró un 92,1% de ellas. No se que halló cepas VRSA. El aislamiento de cepas MRSA se asoció con la procedencia de la UTI (OR=3,38, con la procedencia de Neonatología (OR=0,19, con ser paciente adulto (OR=2,87 y con la muestra de tipo sanguinea (OR=0,35. El tiempo de permanencia de los pacientes con aislamientos de cepas MRSA fue mayor que en los pacientes con cepas sensibles (p<0,007. Conclusiones, No existe riesgo de aparición de cepas VRSA a partir de la interacción de cepas MRSA y VRE en los pacientes hospitalarios de este nosocomio.

  20. Riesgo de aparición de cepas Staphylococcus aureus resistente a vancomicina en pacientes hospitalarios de un hospital del Perú, 2008

    Directory of Open Access Journals (Sweden)

    A. Giancarlo Alvarado-Gamarra

    2012-02-01

    Full Text Available Objetivo: Evaluar el riesgo de aparición de cepas de Staphylococcus aureus resistente a vancomicina (VRSA a partir de la interacción de cepas de Staphylococcus aureus resistente a meticilina (MRSA y cepas de Enterococcus resistente a vancomicina (VRE. Diseño: Análisis bivariado de datos de un estudio descriptivo, transversal y retrospectivo. Lugar: Hospital Nacional Hipólito Unanue de Lima-Perú. Participantes: pacientes hospitalizados durante el año 2008. Intervenciones: Formato de registro del laboratorio del hospital. Principales medidas de resultados: Frecuencias relativas y absolutas para variables cualitativos, y medianas para variables cuantitativos, grado de asociación evaluado con odds ratio (OR con un intervalo de confianza al 95%. Resultados: Se encontró un 82,8% de cepas MRSA, mientras que en la Unidad de Terapia Intensiva (UTI se encontró un 92,1% de ellas. No se que halló cepas VRSA. El aislamiento de cepas MRSA se asoció con la procedencia de la UTI (OR=3,38, con la procedencia de Neonatología (OR=0,19, con ser paciente adulto (OR=2,87 y con la muestra de tipo sanguinea (OR=0,35. El tiempo de permanencia de los pacientes con aislamientos de cepas MRSA fue mayor que en los pacientes con cepas sensibles (p<0,007. Conclusiones: No existe riesgo de aparición de cepas VRSA a partir de la interacción de cepas MRSA y VRE en los pacientes hospitalarios de este nosocomio.

  1. Evaluación de doce materiales de cebolla de bulbo (Allium cepa L. para deshidratación

    Directory of Open Access Journals (Sweden)

    Sandoval A. Héctor L.

    1986-09-01

    Full Text Available El objetivo del ensayo fue la introducción de materiales de cebolla de bulbo (Allium cepa L. de día corto para la deshidratación. Se realizaron observaciones de campo y análisis de laboratorio para determinar sus cualidades industriales.The objective of this assay was the introduction of materials of bulb's onion (Allium cepa L., for short day, to dehydrate. Observations to determinate their field behavior, and laboratories analysis to determinate their industrial characteristics were realized.

  2. Transmisión de cepas atenuadas de babesia bigemina y babesia bovis por garrapatas rhipicephalus (Boophilus) microplus

    OpenAIRE

    Edmundo E. Rojas Ramírez; Juan J. Mosqueda Gualito; Jesús A. Álvarez Martínez; Rubén Hernández Ortíz; Juan A. Ramos Aragón; Carmen Rojas Martínez; Germinal J. Cantó Alarcón; Carlos A. Vega y Murguía; Julio V. Figueroa Millán

    2011-01-01

    Para evaluar la transmisión por garrapatas Rhipicephalus microplus (R. microplus) de una clona atenuada de Babesia bovis (BOR) y una cepa atenuada de Babesia bigemina (BIS), doce bovinos se dividieron en cuatro grupos e infestados de forma escalonada con larvas de R. microplus libres de Babesia spp. Un becerro de cada grupo se inoculó con 1x108 eritrocitos infectados (EI) con BIS, BOR, y cepas virulentas de B. bigemina y B. bovis, respectivamente. Se realizaron dos inoculaciones seriadas adic...

  3. Susceptibilidad antimicrobiana in vitro de cepas de Neisseria gonorrhoeae procesadas en el instituto nacional de salud, Lima, Perú. 1998-1999

    Directory of Open Access Journals (Sweden)

    José Portilla C

    2003-10-01

    Full Text Available Objetivo: Determinar la frecuencia de susceptibilidad y resistencia in vitro de cepas de Neisseria gonorrhoeae, aisladas en el Laboratorio de Bacterias de Transmisión Sexual del Instituto Nacional de Salud, Lima, Perú, frente a los antimicrobianos de uso actual en el tratamiento de la infección por el gonococo; asimismo, conocer la frecuencia con que se presentan las cepas de N. gonorrhoeae productoras de beta-lactamasas. Material y Métodos: Estudio observacional descriptivo. En el Laboratorio de Bacterias de Transmisión Sexual del Instituto Nacional de Salud, Lima, Perú, se recibieron 130 cepas de N. gonorrhoeae (49 en 1998 y 81 en 1999, procedentes de diferentes localidades del país para confirmación bacteriológica. El método de estudio de susceptibilidad antimicrobiana usado fue el de Concentración inhibitoria mínima (CIM frente a la penicilina, espectinomicina, ceftriaxona, cefotaxima, ciprofloxacina y azitromicina. Resultados: La frecuencia de la resistencia de las cepas de N. gonorrhoeae in vitro a la penicilina fue en 15/49 cepas en el año 1998 y 15/81 cepas en el año 1999. Asimismo, la resistencia a la tetraciclina fue en 31/49 cepas en el año 1998 y 51/81 cepas en 1999. El 100% de las cepas estudiadas fueron sensibles a la espectinomicina, ceftriaxona, cefotaxima y ciprofloxacina. En el país, se reporta en 9/81 cepas de N. gonorrhoeae de susceptibilidad disminuida a la azitromicina. Entre los años 1998 y 1999, se reportaron 21/52 y 6/85, respectivamente de cepas de N. gonorrhoeae productoras de beta-lactamasas. Conclusiones: Se encontró resistencia in vitro de cepas de N. gonorrhoeae frente a la penicilina y tetraciclina. Los antibióticos que se deben usar para el tratamiento de la infección son: espectinomicina, ceftriaxona, cefotaxima y ciprofloxacina. Por primer vez se reporta en el país, cepas de susceptibilidad disminuida a la azitromicina.

  4. Sistema de Lotes de Siembra de la cepa vacunal Vibrio cholerae 638

    Directory of Open Access Journals (Sweden)

    Carmen A. del Puerto

    2004-04-01

    Full Text Available En la producción de biológicos, especialmente en aquellos obtenidos a partir de microorganismos, resulta imprescindible contar con un suministro de células caracterizado y estable, como punto de partida para la producción. El concepto de Sistema de Lotes de Siembra en dos niveles, en el cual el Lote de Siembra de Referencia es usado para generar el Lote de Siembra de Trabajo, es considerado el enfoque más práctico para lograr este propósito. En este trabajo se elaboraron los Lotes de Siembra de Referencia y de Trabajo de la cepa vacunal Vibrio cholerae 638, primera etapa de la fabricación de una vacuna contra el cólera, cumpliendo con los requerimientos de Buenas Prácticas de Producción (BPP, lo que constituye una exigencia de las autoridades regulatorias nacionales e internacionales. La caracterización de los lotes demostró que se lograron adecuados niveles de viabilidad y se conservaron inalterables las características de la cepa original en cuanto a identidad, pureza, atenuación de su virulencia, capacidad de colonizar el intestino delgado de ratones lactantes y de inducir una respuesta inmune.

  5. In vitro antibacterial activity of onion (allium cepa) against clinical isolates of vibrio cholera

    International Nuclear Information System (INIS)

    Background: Cholera is a major public health problem in developing countries of the world. Bacterial resistance, lack of surveillance data and proper microbiological facilities are major problems regarding diagnosis of cholera. The spread of microbial drug resistance is a global public health challenge that results in increased illness and death rate. Newer antimicrobials or agents are urgently required to overcome this problem. This work was therefore done to investigate the antimicrobial potential of onion against thirty-three clinical isolates of Vibrio cholera. Methods: The extract was prepared by reflux extraction method. Antibacterial screening of clinical isolates of V. cholerae was done by agar well diffusion method. Agar dilution method was used to assess the Minimum Inhibitory Concentration (MIC). Results: All tested strains of V. cholerae were sensitive to onion (Allium cepa) extracts of two types (purple and yellow). Purple type of extract had MIC range of 19.2-21.6 mg/ml. The extract of yellow type onion had an MIC range of 66-68.4 mg/ml. Conclusion: The results indicated that onion (Allium cepa) has an inhibitory effect on V. cholerae. Keeping in view the anti-bacterial activity of this compound can be exploited as a therapeutic agent in an animal model. This finding is a positive point for further investigation of this herb of traditional medicine. (author)

  6. POTASSIUM AND ITS EFFECT ON THE CONTENT OF POLYPHENOLS IN ONION (ALLIUM CEPA L.

    Directory of Open Access Journals (Sweden)

    Petra Kavalcová

    2015-02-01

    Full Text Available Onion (Allium cepa L. is rich of chemoprotective compounds as polyphenols, flavonoids, anthocyanins, vitamins, sulphur compounds which have potential beneficial properties for human health. Potassium as important mineral abundant plays many vital roles in plant nutrition (reduces respiration, activates enzyme. In generally, potassium increases crop yield and improves quality of onion bulbs. The objectives of this work were to compare and evaluate the impact of potassium on the content of total polyphenols and antioxidant activity of onion (Allium cepa L.. The content of the total polyphenols was determined by using the Folin-Ciocalteu reagent (FCR. The absorbance was measured at 765 nm of wave length against blank. Antioxidant activity was measured using a compound DPPH˙ (2.2-diphenyl-1-picrylhydrazyl at 515.6 nm in the spectrophotometer. The content of total polyphenols in samples of onion during vegatation period moved in the range from 505.6 mg GAE/kg ±25.18 to 621.49 mgGAE/kg ±13.41. In this work was watched also the influence of potassium on antioxidant activity, where values were in interval from 32.20 %± 0.58 to 44.67 % ±0.68.

  7. Cytogenetic effects of three commercially formulated pesticides on somatic and germ cells of Allium cepa.

    Science.gov (United States)

    Kuchy, Aashiq H; Wani, Aijaz A; Kamili, Azra N

    2016-04-01

    Cytological effects of Endosri-ES (endosulfan), Nuvan-NU (dichlorvos), and Kvistin-KS (carbendazim) were evaluated on mitotic and meiotic cells of Allium cepa. Test concentrations were chosen by calculating EC50 values of formulated ES, NU, and KS, which turned to be 60, 200, and 500 ppm (parts per million), respectively. Cytological studies were undertaken on root meristem cells of A. cepa using EC50, 1/2 × EC50, and 2 × EC50 of these pesticides for 24 and 48 h. Similarly, a meiotic study was conducted by applying the pesticides at the aforesaid concentrations from seedling to bud stage. A set of onion bulbs exposed to tap water was run parallel for negative control and maleic hydrazide (112.09 ppm) as positive control. During the study period, mitotic index (MI) decreased at all the pesticide concentrations compared to the negative control. Among various chromosomal aberrations, chromatin bridges, breaks, stickiness, laggard, vagrant chromosomes, fragments, C-mitosis, multipolarity, ring chromosome as well as micronuclei were observed in mitotic preparations. In contrast, meiotic aberrations revealed comparatively less frequency of chromosomal aberrations and the most frequent were lagging chromosome, stray bivalents, secondary association, chromatin bridge, disturbed anaphase, and stickiness. Comparative analysis of the pesticides showed that NU was highly toxic to plant cells than KS, while as ES showed intermediate effects between the two. Further, our study revealed that all the three pesticides produce genotoxic effects which can cause health risks to the human populations. Graphical Abstract ᅟ.

  8. Diferenciação de cepas de Candida albicans pelo sistema killer

    Directory of Open Access Journals (Sweden)

    Regina Celia Cândido

    1995-12-01

    Full Text Available Foi estudado o efeito killer de 9 cepas padrão de leveduras sobre 146 amostras de Candida albicans isoladas dos seguintes espécimes clínicos: mucosa bucal, fezes, lavado brônquico, escarro, secreção vaginal, urina, lesão de pele, lesão de unha e sangue. Usando este sistema foi possível diferenciar 23 biotipos de C. albicans. Os biotipos 211, 111 e 811 foram os mais freqüentemente isolados. A maioria das amostras de C. albicans (98,6% foi sensível a pelo menos uma ou mais das 9 cepas killer. Empregando- se este sistema foi possível demonstrar que 2 pacientes albergavam mesmo biotipo killer, respectivamente, 111 e 211, em diferentes espécimes clínicos, e em outro paciente, o mesmo biotipo (211 foi isolado de hemoculturas realizadas em ocasiões distintas. O uso do sistema killer para diferenciar os tipos entre as espécies de leveduras patogênicas, pode ser um método útil para estabelecer a eventual fonte de infecção, constituindo uma ajuda valiosa para o controle e vigilância de infecções nosocomiais causadas por leveduras.

  9. Resistencia antimicrobiana de cepas de Staphylococcus aureus, Costa Rica Antimicrobial resistance of Staphylococcus aureus, Costa Rica

    Directory of Open Access Journals (Sweden)

    Víctor Hugo Alvarado

    2011-12-01

    Full Text Available Objetivo: Determinar y comparar los perfiles de resistencia de cepas de S. aureus aisladas de quesos, producidos en la Zona Sur de Costa Rica y de un centro hospitalario de la misma región. Materiales y Métodos: Se analizaron 35 muestras de queso fresco, adquiridas durante los meses de setiembre y octubre del 2010 en la zona de San Vito de Coto Brus. A cada muestra se le realizaron recuentos de coliformes totales, coliformes fecales y Staphylococcus aureus. Adicionalmente se analizó presencia/ausencia de Listeria monocytogenes en 25 gramos del producto. A las cepas identificadas como S. aureus se les realizó la prueba de sensibilidad a los antibióticos mediante el sistema automatizado Vitek y la interpretación de los datos se realizó siguiendo las pautas del Clinical and Laboratory Standards Institute antimicrobial susceptibility testing 2011. Adicional a esto se recolectaron datos acerca de la sensibilidad de las cepas de S. aureus aisladas e identificadas en el Hospital de San Vito de Coto Brus en el mismo período. Resultados: El promedio obtenido para el recuento de coliformes totales fue de 9,7 X 10(6 UFC/g, para coliformes fecales de 6,7 X 10(5 y para S. aureus de 2,8 X 10(5 UFC/g, obteniéndose un 83 % de muestras positivas por esta bacteria. En cuanto a la resistencia antimicrobiana, se obtuvieron porcentajes de resistencia mayores en las cepas de origen clínico. Se encontró también que 23 de las cepas (96% provenientes de muestras clínicas, presentaban resistencia a más de un antibiótico, mientras que siete de las obtenidas a partir de queso (27% presentaban esta característica. Con respecto a los betalactamicos (ampicilina, oxacilina y penicilina se observó la existencia de una diferencia estadísticamente significativa (pObjective: determined and compared the resistance patters of S. aureus strains isolated from cheese produced in the southern zone of Costa Rica and from clinical samples isolated at the hospital center

  10. Disponibilidade hídrica e germinação de sementes de cebola (Allium cepa L. Water availability and germination of onion seeds (Allium cepa L.

    Directory of Open Access Journals (Sweden)

    Z. Piana

    1994-12-01

    Full Text Available Objetivando verificar a influência do teor de água do substrato na germinação de sementes de cebola (Allium cepa L., conduziu-se um ensaio sob condições de ambiente de laboratório. Os efeitos de cinco níveis de água no substrato solo x areia (3:1, 20, 40, 60, 80 e 100% da capacidade de retenção foram avaliados através da porcentagem de emergência no 14° dia da semeadura e pesos da matéria verde e seca das plântulas normais. Para tanto, 200 sementes do cultivar Pira Ouro por tratamento, em quatro repetições de 50, foram semeadas a 1,5 cm de profundidade, mantendo-se constantes os níveis de água no substrato. Os resultados possibilitaram concluir que os níveis de umidade do solo indicados para germinação de sementes de cebola são de 40% e 60% da capacidade de retenção do substrato, por possibilitarem uma melhor emergência, peso da matéria verde e seca das plântulas.One essay was conducted under laboratory conditions, in order to verify the influence of substrate water content on the germination of onion (Allium cepa L. seeds. The effect of five water levels in the medium soil x sand (3:1 - 20, 40, 60, 80 and 100% retention capacity-were evaluated through the emergence percentage 14 days after seedling and the weight of fresh and dry matters of normal seedlings. For that purpose, 200 treated seeds of Pira Ouro cultivar were sown 1.5 cm deep in four replicátions of 50, with a constant water content in the medium. The best results showed that the soil moisture levels suggested for the germination of onion seeds were 40% to 60% of the substrate retention capacity, once they provide better emergence, weight of the fresh and dry matters of seedlings.

  11. Comportamento da cepa LE de Schistosoma mansoni, após passagem em hospedeiro humano infectado acidentalmente

    Directory of Open Access Journals (Sweden)

    Neusa Araújo

    1986-12-01

    Full Text Available Uma auxiliar de laboratório infectou-se acidentalmente, com cercárias de Schistosoma mansoni, cepa LE, mantida rotineiramente em nossos laboratórios. Decorridos 5 meses, o exame parasitológico de fezes revelou 108 ovos/g . A pacientefoi tratada com oxamniquine, porém a infecção continuou ativa (6 ovos/g. Foi então obtido o isolado SSF mantido no modelo Biomphalaria glabrata - camundongo albino. Os resultados obtidos no estudo comparativo, entre o isolado SSF e a cepa LE, que lhe deu origem, mostraram que a duração do período pré-patente e o índice de infectividade em camundongos, bem como a resposta aos agentes esquistossomicidas (hycanthone, oxamniquine epraziquantel não apresentaram diferenças estatisticamente significativas. Por outro lado, o número de miracídios obtidos dos intestinos e fígados dos camundongos infectados foi o dobro com a cepa LE, quando comparados com aquele do isolado SSF. Também a variação do peso dos animais foi bastante diferente. Concluiu-se que apenas uma passagem pelo hospedeiro humano não mudou substancialmente as características da cepa estudada.

  12. Inhibitive and Adsorption Properties of Ethanolic Extract of Allium Cepa for the Corrosion of -?Brass in HNO3 Solutions

    OpenAIRE

    Fouda, Abd El-Aziz S.; Nofal, Ashraf M.; Maher, Reham

    2015-01-01

    Ethanol extract of allium cepa has been evaluated as a green corrosion inhibitor for ?-brass in HNO3 solutions using weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM) techniques. Potentiodynamic polarization measurements showed that this extract acts as a mixed type inhibitor. The inhibition efficiency increases with increasing the extract concentration, but decreases with raising the temperature. The adsorpt...

  13. Immunolcocalization of actin in intact and DNA—and histone—depleted nuclei and chromosomes of allium cepa

    Institute of Scientific and Technical Information of China (English)

    WANLIHONG; MIAOXING

    1998-01-01

    The presence of actin in eukaryotic nuclei and chromosomes,and especially in higher plant nuclei and chromosomes,has not been well established.We detected actin in meristematic cells of Allium cepa with indirect immunofluorescence technique and observed bright fluorescence in the intact nuclei and chromosomes,indicating that actin is present in the nuclei and chromosomes of the higher plant.We labeld sections of the meristematic cells of A.cepa with immunogold technique,gold parti cles were concentrated in condensed chromatin and nucleoli,confirming the results of the immunofluoresence observations.We traeated the nuclei and chromosomes of A.cepa with DNase I and 2M NaCl and obtained DNA-and histone-depleted nuclei and chromosomes.Indirect immunofluorescence tests showed that the DNA-and histonedepleted nuclei and chromosomes reacted positively with the anti-actin antibodies.These results demonstrate that the anti-actin antibodies.These results demonstrate that actin exists not only in intact nuclei and chromosomes,but also in DNA-and histone-depleted nuclei and chrmosomes of the plant.In addition,our immuno-fluorescence tests indicate that tropomyosin is present in the nuclei and chromosomes of A.cepa.

  14. Beneficial effects of Allium sativum, Allium cepa and Commiphora mukul on experimental hyperlipidemia and atherosclerosis--a comparative evaluation.

    OpenAIRE

    Lata S; Saxena K; Bhasin V; Saxena R; Kumar A; Srivastava V

    1991-01-01

    Oral administration of petroleum ether extract of Allium sativum, Allium cepa and ethylacetate extract of Commiphora mukul in albino rats significantly prevented rise in serum cholesterol and serum triglyceride level, caused by atherogenic diet. All the three agents were also found to confer significant protection against atherogenic diet induced atherosclerosis.

  15. 维药洋葱子质量标准研究%Research on quality specification of Allium cepa seed

    Institute of Scientific and Technical Information of China (English)

    赵翡翠; 何强; 聂继红

    2012-01-01

    Objective: To provide scientific basis for the utilization and development of Allium cepa seed by setting up the quality control specification of Allium cepa seed. Methods: Collecting different origin of 10 batch Allium cepa seed samples.the original plant of which were identificated, the properties of which were described, the powder of which were microscopic identificated. And Allium cepa seed were identificated on TLC method in contrast to p -Sitosterol. Determination of the 10 batch Allium cepa seed of impurities, moisture, ash, peroxide value and extract according to Chinese Pharmacopoeia 2010 version (Vol I ) of appendix K H and K. The fatty oil determination method of Allium cepa seed were inspected according to Chinese Pharmacopoeia 2010 version (Vol I ) of appendix K N. Results: The origins, macroscopic and microscopic identification of Allium cepa seed are described, and the TLC identification method was formulated with thiacyclohexane-ethyl ether-ethyl acetate (20^5.5:2.5) as developing solvent, temporarily formulating impurities can not lead 1.4%, moisture can not lead 10.0%, total ashes can not lead 12.0%, acid-insoluble ashes can not lead 6.50%, peroxide value can not lead 0.13, extract not less 10.00%. Determine the fatty oil of Allium cepa seed shall be not less than 9.0% . Conclusion: Setting the Allium cepa seed quality control standard can be used to evaluate the quality of Allium cepa seed.%目的:建立维药洋葱子的质量控制标准.方法:于不同产地采集10批洋葱子样品,对其原植物进行鉴定,对其性状进行鉴别;对其粉末进行显微鉴别;以β-谷甾醇为对照品对洋葱子药材进行薄层色谱鉴别;按照《中国药典》2010年版(一部)附录测定10批洋葱子药材的杂质、水分、总灰分、酸不溶性灰分、过氧化值、浸出物;按照《中国药典》2010年版(一部)附录测定10批洋葱子药材的脂肪油含量.结果:对洋葱子药材的来源、性状进行了描

  16. Caracterización fisiológica y molecular de cepas vínicas Saccharomyces sp. Influencia en su comportamiento durante la vinificación.

    OpenAIRE

    Zuzuarregui Miró, Aurora

    2005-01-01

    RESUMEN La transformación del mosto de uva en vino es un proceso microbiológico complejo aunque la fermentación alcohólica es llevada a cabo generalmente por cepas de Saccharomyces. El uso de inóculos de cepas preseleccionadas es frecuente en bodega dado que la cepa iniciadora se impone sobre las indígenas proporcionando ventajas encaminadas a una mayor producción y a una mejora de la calidad. El empleo de cultivos iniciadores hace necesario el establecimiento de criterios de selecci...

  17. Nuevas cepas de duganella aisladas de la rizosfera de olivo silvestre y cultivado y su uso en la producción de violaceína

    OpenAIRE

    Landa, Blanca B.; Aranda Ocampo, Sergio; Montes Borrego, Miguel; Castillo, Pablo

    2010-01-01

    [ES] La presente invención se refiere a unas cepas bacterianas de Duganella spp. obtenidas de la rizosfera de olivos silvestres y cultivados. Preferentemente las cepas son CECT 7779, CECT 7780 y CECT 7781 y más preferentemente la cepa bacteriana es CECT 7780. Además, la presente invención se refiere a sus combinaciones con otros microorganismos y a las composiciones que comprenden los productos anteriores, así como a un procedimiento para la producción de violaceína y a la violaceína produ...

  18. Nuevas cepas de duganella aisladas de la rizosfera de olivo silvestre y cultivado y su uso en la producción de violaceína

    OpenAIRE

    Landa, Blanca B.; Aranda Ocampo, Sergio; Montes Borrego, Miguel; Castillo Castillo, Miguel

    2010-01-01

    La presente invención se refiere a unas cepas bacterianas de Duganella spp. obtenidas de la rizosfera de olivos silvestres y cultivados. Preferentemente las cepas son CECT 7779, CECT 7780 y CECT 7781 y más preferentemente la cepa bacteriana es CECT 7780. Además, la presente invención se refiere a sus combinaciones con otros microorganismos y a las composiciones que comprenden los productos anteriores, así como a un procedimiento para la producción de violaceína y a la violaceína producida par...

  19. Dissection of Trichoderma longibrachiatum-induced defense in onion (Allium cepa L.) against Fusarium oxysporum f. sp. cepa by target metabolite profiling.

    Science.gov (United States)

    Abdelrahman, Mostafa; Abdel-Motaal, Fatma; El-Sayed, Magdi; Jogaiah, Sudisha; Shigyo, Masayoshi; Ito, Shin-ichi; Tran, Lam-Son Phan

    2016-05-01

    Trichoderma spp. are versatile opportunistic plant symbionts that can cause substantial changes in the metabolism of host plants, thereby increasing plant growth and activating plant defense to various diseases. Target metabolite profiling approach was selected to demonstrate that Trichoderma longibrachiatum isolated from desert soil can confer beneficial agronomic traits to onion and induce defense mechanism against Fusarium oxysporum f. sp. cepa (FOC), through triggering a number of primary and secondary metabolite pathways. Onion seeds primed with Trichoderma T1 strain displayed early seedling emergence and enhanced growth compared with Trichoderma T2-treatment and untreated control. Therefore, T1 was selected for further investigations under greenhouse conditions, which revealed remarkable improvement in the onion bulb growth parameters and resistance against FOC. The metabolite platform of T1-primed onion (T1) and T1-primed onion challenged with FOC (T1+FOC) displayed significant accumulation of 25 abiotic and biotic stress-responsive metabolites, representing carbohydrate, phenylpropanoid and sulfur assimilation metabolic pathways. In addition, T1- and T1+FOC-treated onion plants showed discrete antioxidant capacity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) compared with control. Our findings demonstrated the contribution of T. longibrachiatum to the accumulation of key metabolites, which subsequently leads to the improvement of onion growth, as well as its resistance to oxidative stress and FOC. PMID:26993243

  20. Establecimiento de un medio de cultivo sumergido para una cepa nativa de un hongo poliporal

    OpenAIRE

    Peña Serna Carolina; Sierra Cadavid Andrea; Sáez Vega Alex Armando; Rojano Benjamín Alberto

    2007-01-01

    Se evaluó el efecto de dos velocidades de agitación (80 y 100 rpm), dos fuentes de carbono (glucosa y sacarosa) y tres pH iniciales (5.5, 6.0 y 6.5) sobre la producción de fenoles totales, la actividad antioxidante, el crecimiento micelial y el consumo de sustrato de una cepa nativa de un hongo perteneciente al orden Poliporal en cultivo sumergido.El mayor crecimiento micelial se obtuvo al día 3 con un valor de 10 g/L a una velocidad de agitación de 80 rpm, sacarosa como fuente de carbono y p...

  1. Controlled green synthesis of silver nanoparticles by Allium cepa and Musa acuminata with strong antimicrobial activity

    Science.gov (United States)

    Sahni, Geetika; Panwar, Amit; Kaur, Balpreet

    2015-02-01

    A controlled "green synthesis" approach to synthesize silver nanoparticles by Allium cepa and Musa acuminata plant extract has been reported. The effect of different process parameters, such as pH, temperature and time, on synthesis of Ag nanoparticles from plant extracts has been highlighted. The work reports an easy approach to control the kinetics of interaction of metal ions with reducing agents, stabilized by ammonia to achieve sub-10 nm particles with narrow size distribution. The nanoparticles have been characterized by UV-Visible spectra and TEM analysis. Excellent antimicrobial activity at extremely low concentration of the nanoparticles was observed against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Fusarium oxysporum which may allow their exploitation as a new generation nanoproduct in biomedical and agricultural applications.

  2. Effect of gamma irradiation on the storage and vitamin C concentration of allium cepa onion samples

    International Nuclear Information System (INIS)

    This study was done to investigate the effect of gamma irradiation on storage, germination and vitamin C concentration of local onion (Allium cepa). 5 onion samples were irradiated with 5 different radiation doses (0.1, 0.2, 0.3, 0.4, and 0.5 k Gray) using cobalt-60 irradiator (Nor din) compared to non irradiated samples as controls. The irradiated and control onions were stored at room temperature for three months. The results of this study showed that the non irradiated samples were either deteriorated or grown while all the irradiated samples were not. Regarding the concentration of vitamin C it was clear that it decreased with the dose increase from 30.53 to 14.44 mg/100 g. This study concluded that the irradiation is very effective in prevention of spoilage, elongation of germination period and decrease of vitamin C concentration.(Author)

  3. Arbuscular mycorrhiza improves yield and nutritional properties of onion (Allium cepa).

    Science.gov (United States)

    Rozpądek, Piotr; Rąpała-Kozik, Maria; Wężowicz, Katarzyna; Grandin, Anna; Karlsson, Stefan; Ważny, Rafał; Anielska, Teresa; Turnau, Katarzyna

    2016-10-01

    Improving the nutritional value of commonly cultivated crops is one of the most pending problems for modern agriculture. In natural environments plants associate with a multitude of fungal microorganisms that improve plant fitness. The best described group are arbuscular mycorrhizal fungi (AMF). These fungi have been previously shown to improve the quality and yield of several common crops. In this study we tested the potential utilization of Rhizophagus irregularis in accelerating growth and increasing the content of important dietary phytochemicals in onion (Allium cepa). Our results clearly indicate that biomass production, the abundance of vitamin B1 and its analogues and organic acid concentration can be improved by inoculating the plant with AM fungi. We have shown that improved growth is accompanied with up-regulated electron transport in PSII and antioxidant enzyme activity.

  4. Arbuscular mycorrhiza improves yield and nutritional properties of onion (Allium cepa).

    Science.gov (United States)

    Rozpądek, Piotr; Rąpała-Kozik, Maria; Wężowicz, Katarzyna; Grandin, Anna; Karlsson, Stefan; Ważny, Rafał; Anielska, Teresa; Turnau, Katarzyna

    2016-10-01

    Improving the nutritional value of commonly cultivated crops is one of the most pending problems for modern agriculture. In natural environments plants associate with a multitude of fungal microorganisms that improve plant fitness. The best described group are arbuscular mycorrhizal fungi (AMF). These fungi have been previously shown to improve the quality and yield of several common crops. In this study we tested the potential utilization of Rhizophagus irregularis in accelerating growth and increasing the content of important dietary phytochemicals in onion (Allium cepa). Our results clearly indicate that biomass production, the abundance of vitamin B1 and its analogues and organic acid concentration can be improved by inoculating the plant with AM fungi. We have shown that improved growth is accompanied with up-regulated electron transport in PSII and antioxidant enzyme activity. PMID:27318800

  5. Effect of 5-Aminouracil on mitotic cell division in Allium cepa Efeito de 5-Aminouracil na divisão mitótica de células de Allium cepa

    Directory of Open Access Journals (Sweden)

    Veronica Elisa Pimenta Vicentini

    1999-07-01

    Full Text Available A exposição de células meristemáticas de Allium cepa por dois ciclos de divisões (48 horas, em soluções contendo concentrações mais baixas de 5-aminouracil (50, 100 e 150μM do que as usualmente empregadas para proceder à sincronização da proliferação celular, mostrou que as concentrações usadas causam anormalidades cromossômicas e formação de micronúcleos, mas não bloqueiam a entrada destas células em mitose. As células em mitose e com micronúcleos podem prosseguir em divisão e assim contribuir para o crescimento das raízes de A. cepa expostas às concentrações de 5-aminouracil estudadas. As células meristemáticas da raiz de A. cepa parecem suportar um certo nível de danos não reparados no DNA, os quais não impedem a divisão celular e o conseqüente crescimento dos tecidos. Esta flexibilidade genética do genoma de vegetais deve se constituir numa resposta metabólica adaptativa para sustentar condições ambientais adversas.Cytological preparations of Allium cepa meristematic cells were examined under a light microscope to evaluate the effect of prolonged exposure (at least two-cell cycle to 5-aminouracil (5-AU on mitotic cell division in the roots. The results are a cytological demonstration that a lower concentration of 5-AU than usually employed for synchronizing proliferating cells in A. cepa root meristems induces chromosomal abnormalities and formation of micronucleus but does not fully block the cell flow into mitosis, and that micronucleated cells can proceed in mitosis and contribute to the enhancement of root length values reported by other authors. A. cepa root tip cells seems to support a certain damage level in DNA (around 10% of micronucleated cells in mitosis without having any negative effect on cellular proliferation and growth of the roots. This genetic flexibility of vegetable genomes may permit an attenuation of the adaptative metabolic-response to sustained adverse environmental conditions.

  6. Uso do sistema teste de Allium cepa como bioindicador de genotoxicidade de infusões de plantas medicinais The use of Allium cepa test as a bioindicator of genotoxicity of medicinal plants infusions

    Directory of Open Access Journals (Sweden)

    Margarete Dulce Bagatini

    2007-09-01

    Full Text Available Mundialmente, muitas espécies de plantas medicinais são utilizadas para o tratamento de doenças. No entanto, a maioria dessas espécies não foram suficientemente estudadas, principalmente quanto à presença de substâncias citotóxicas/mutagênicas em sua composição ou decorrentes do próprio metabolismo e podem causar danos à saúde da população. A presença de substâncias mutagênicas nas espécies vegetais que causam alterações cromossômicas podem ser detectadas durante o ciclo celular de uma espécie. O sistema teste de Allium cepa é freqüentemente utilizado para avaliação do potencial genotóxico de extratos de plantas medicinais através da análise de células meristemáticas provenientes de pontas de raízes tratadas com infusões medicinais (chás. O conhecimento do potencial genotóxico destas espécies medicinais, através da análise do ciclo celular de Allium cepa serve como indicativo de segurança para a população que utiliza chás medicinais como única alternativa para o tratamento de doenças. Essa revisão, objetiva informar a respeito da importância do teste de Allium cepa para avaliação preliminar da genotoxicidade de infusões de plantas medicinais.All over the world, many species of medicinal plants are used for disease treatments. However, most of them were not deeply studied; and the presence of cytotoxic or mutagenic substances in their composition or resulting from their metabolism may be harmful to human beings. The mutagenic effects caused by such substances result in chromosomal changes which are detecTable during the cell cycle of a species through cytogenetic analysis. The Allium cepa test system is widely used for evaluating the genotoxic potential of infusions (tea made of medicinal plants, through the cell cycle analysis. The knowledge of the genotoxic potential of such species through the Allium cepa test serves as a warning and safety bioindicator for the population who uses medicinal

  7. Cepas de Campylobacter jejuni resistentes a quinolonas aisladas de humanos, gallinas y pollos

    Directory of Open Access Journals (Sweden)

    Rodolfo Notario

    2011-08-01

    Full Text Available Se compararon 8 aislamientos de Campylobacter jejuni provenientes de humanos con enfermedad diarreica aguda, con 23 aislamientos de cloaca de gallinas y pollos obtenidos de zonas próximas a la ciudad de Rosario, todos resistentes a la ciprofloxacina. Las muestras se sembraron en agar selectivo y se incubaron en microaerofilia a 42 °C. Las colonias se identificaron con el método tradicional. Los aislamientos se conservaron a -70 °C en caldo cerebro corazón con 17% v/v de glicerina. La clonalidad se determinó por RAPD-PCR, utilizando el primer 1254 (Stern NJ. Se interpretaron los aislamientos como clones distintos cuando diferían en una banda de amplificación. Se obtuvieron 5 clones diferentes. Los patrones I, II y V fueron aislados en criaderos industriales de pollos y en humanos (el II también en un establecimiento de gallinas ponedoras de huevos. En un gallinero familiar se obtuvo el patrón I. El patrón III sólo se obtuvo de humanos. El patrón IV se halló en uno de los criaderos pero no en humanos. Se pudo determinar que 93.5% de las cepas se aislaron tanto de animales como de humanos, por lo que se considera posible que la colonización de criaderos con cepas resistentes a los antimicrobianos pudiera ser el origen de la infección de humanos.

  8. Molecular and Functional Characterization of FLOWERING LOCUS T Homologs in Allium cepa

    Directory of Open Access Journals (Sweden)

    Ranjith Kumar Manoharan

    2016-02-01

    Full Text Available Onion bulbing is an important agricultural trait affecting economic value and is regulated by flowering-related genes. FLOWERING LOCUS T (FT-like gene function is crucial for the initiation of flowering in various plant species and also in asexual reproduction in tuber plants. By employing various computational analysis using RNA-Seq data, we identified eight FT-like genes (AcFT encoding PEBP (phosphatidylethanolamine-binding protein domains in Allium cepa. Sequence and phylogenetic analyses of FT-like proteins revealed six proteins that were identical to previously reported AcFT1-6 proteins, as well as one (AcFT7 with a highly conserved region shared with AcFT6 and another (comp106231 with low similarity to MFT protein, but containing a PEBP domain. Homology modelling of AcFT7 proteins showed similar structures and conservation of amino acids crucial for function in AtFT (Arabidopsis and Hd3a (rice, with variation in the C-terminal region. Further, we analyzed AcFT expression patterns in different transitional stages, as well as under SD (short-day, LD (long-day, and drought treatment in two contrasting genotypic lines EM (early maturation, 36101 and LM (late maturation, 36122. The FT transcript levels were greatly affected by various environmental factors such as photoperiod, temperature and drought. Our results suggest that AcFT7 is a member of the FT-like genes in Allium cepa and may be involved in regulation of onion bulbing, similar to other FT genes. In addition, AcFT4 and AcFT7 could be involved in establishing the difference in timing of bulb maturity between the two contrasting onion lines.

  9. La morfología de los cuerpos paraesporales y su relación con la actividad biológica en cepas cubanas de Bacillus thuringiensis

    Directory of Open Access Journals (Sweden)

    Bertha Carreras

    2008-01-01

    Full Text Available La principal característica de la bacteria Bacillus thuringiensis es la producción de cuerpos paraesporales (cristales proteicos, los cuales constituyen el principio activo de bioinsecticidas comerciales. La morfología de los cuerpos paraesporales es uno de los criterios más utilizados en la caracterización de cepas de B. thuringiensis. El objetivo del presente trabajo fue estudiar la morfología de los cuerpos paraesporales de tres cepas nativas de B. thuringiensis (LBT-87, LBT-99 y LBT-111 y determinar si existe una correlación entre este elemento y la toxicidad preferencial informada previamente para cada cepa. Las muestras de B.thuringiensis estudiadas procedieron de la colección de cepas del Instituto de Investigaciones de Sanidad Vegetal, Ciudad de La Habana. Las muestras de bacterias se analizaron mediante Microscopia Óptica y Microscopia Electrónica de Transmisión. Para Microscopia Óptica se estudiaron frotis de cultivos autolisados de B. thuringiensis teñidos con violeta cristal. Para Microscopia Electrónica de Transmisión, se analizaron cortes ultrafinos obtenidos a partir de precipitados de B. thuringiensis incluidos en resina Spurr. La morfología de los cristales estuvo en correspondencia con la actividad biológica informada para cada cepa. La cepa LBT-87, tóxica contra el insecto díptero D. melanogaster, presentó cristales irregulares con inclusiones en forma de barra. La cepa LBT-111, tóxica contra el insecto lepidóptero H. virescens, presentó cristales bipiramidales y cúbicos. La cepa LBT-99, tóxica contra el nemátodo M. incognita, presentó un cristal muy pequeño adherido a la espora.

  10. Optimizing the Utility of Allium cepa L. var. aggregatum (sibuyas Tagalog for the Allium Test by Elucidating its Mitotic Periodicity and Rhythmicity Under Varying Light Conditions

    Directory of Open Access Journals (Sweden)

    Ambrocio Melvin A. Matias

    2011-06-01

    Full Text Available The occurrence of pattern of mitotic activity has long been studied in different plants; in the onion Allium cepa, determination of its mitotic activity has led to its utilization in the Allium test for cytotoxicity and mutagenicity of test substances. In this study, the pattern of mitotic activity of A. cepa var. aggregatum and the effect of light exposure on mitotic activity were determined to test the utility of A. cepa L. var. aggregatum as an alternative to the common onion, A. cepa, for the Allium test. Bulblets of A. cepa var. aggregatum were allowed to root for three days in tap water under three different set-ups: constant light exposure set-up (Light, constant dark set-up (Dark and 12 hours light-12 hours dark set-up (Light-Dark. The root tips from the bulblets were then excised and subjected to microscopic observation for the mitotic index (MI every hour after the third day. The results showed no significant difference observed across the three set-ups. However, MI for the Dark and Light set-ups were periodic, showing peaks or maxima of MI falling between 11 AM and 12 PM, whereas that of Light-Dark set-up was rhythmic, having an hourly fluctuation, but also showed maximum between 11 AM and 12 PM. It is recommended that A. cepa var. aggregatum root tips be excised between 11 AM and 12 PM for the Allium test.

  11. Changes in the hemolymph of female Haemaphysalis longicornis Neumann (Acari: Ixodidae) after infection by Heterorhabditis bacteriophora (Nematoda: Heterorhabditidae)%长角血蜱雌蜱感染嗜菌异小杆线虫后血淋巴的变化

    Institute of Scientific and Technical Information of China (English)

    高志华; 杨小龙; 刘敬泽; 简恒

    2006-01-01

    用嗜菌异小杆线虫Heterorhabditis bacteriophora E-6-7(Hb E-6-7)感染长角血蜱Haemaphysalis longicornis雌蜱,测定感染后雌蜱血淋巴总蛋白含量、酯酶活性及酯酶同工酶的变化,以探讨昆虫病原线虫对蜱的致病机理.结果显示,雌蜱血淋巴总蛋白含量在Hb E-6-7感染后12 h显著增加,达到最大值92.21 μg/μL;在感染后24 h明显下降(49.06 μg/μL);至感染后48 h降至34.25 μg/μL.雌蜱血淋巴酯酶活性在线虫感染后0~12 h内无显著变化;在感染24 h后迅速增加(OD24h=0.1840, OD36h=0.1940, OD48h=0.2165),与对照组差异显著.PAGE结果表明,线虫感染后导致雌蜱血淋巴酯酶同工酶电泳图谱发生变化,主要为电泳图谱两端a带和b带的消失以及一条c带的增加.上述结果表明,长角血蜱雌蜱被Hb E-6-7感染后其血淋巴总蛋白含量和酯酶发生变化,这种变化可能与蜱的防御和对昆虫病原线虫的适应有关.

  12. Seleccion de cepas de rizobios en suelos promisorios para el cultivo de la soya (Glycine max (L Merril en Colombia

    Directory of Open Access Journals (Sweden)

    Sylvester Bradley Rosemary

    1989-06-01

    Full Text Available En el invernadero se evaluó la efectividad de las cepas preseleccionadas de B. japonicum (CIAT 199,209,3778,3874 y 3876 de la recomendada (CIAT51 y una de Rhizobium spp (CIAT 3779. En el suelo Fluventic Haplustoll, de reacción casi neutra, se presentó respuesta altamente significativa a la inoculación. El tratamiento fertilizado con 150 kg de N/ha produjo el mayor rendimiento de N. Las cepas más efectivas fueron CIAT 3778 y 51, que también presentaron el mayor indice de efectividad a la inoculación (IEI. En el suelo Typic Pellustert,de reacción alcalina, se presentó respuesta significativa a la inoculación. El mayor rendimiento de N se obtuvo con las cepas CIAT 3778 y 51, que fueron además estadísticamente iguales a las cepas CIAT 199 y 3876 en cuanto al IEI. En el suelo Arenic Haplustalf, de reacción ligeramente ácida, hubo respuesta altamente significativa a la inoculación y la cepa más efectiva fue la CJAT 199. En el suelo Fluventic Ustropept, de reacci6n ligeramente ácida, se presentaron diferencias significativas entre los tratamientos inoculados. El mayor rendimiento de N se presentó en el tratamiento fertilizado con N. Las mejores cepas fueron CIAT 3778,3779 y 209. En el suelo Vertic Ustropept, de reacción alcalina, se presentó respuesta altamente significativa a la inoculación. En cuanto al rendimiento de N no se encontraron diferencias entre el tratamiento fertilizado con N y las cepas CIAT 51, 209 y CIAT 3778, siendo también las más efectivas en cuanto al IEI, junto oon la cepa CIAT 199. En los suelos Tropentic Haplorthox y Typic Tropudult no se enoontró respuesta a la inoculación.Screening of Rhizobium strains in soils apt for soybean (Glycine max (L Merril cultivation in Colombia. Under greenhouse conditions were evaluated the effectivity of the preselected strains of the preselected strains of B. japonicum (CIAT 199, 209, 3778, 3874 and 3876, in addition to the recommended strain (CIAT 51 and one of

  13. Mutagenic and antimutagenic effects of aqueous extract of rosemary (Rosmarinus officinalis L.) on meristematic cells of Allium cepa.

    Science.gov (United States)

    Felicidade, I; Lima, J D; Pesarini, J R; Monreal, A C D; Mantovani, M S; Ribeiro, L R; Oliveira, R J

    2014-01-01

    Polyphenolic compounds present in rosemary were found to have antioxidant properties, anticarcinogenic activity, and to increase the detoxification of pro-carcinogens. The aim of the study was to determine the effect the aqueous extract of rosemary (AER) on mutagenicity induced by methylmethane sulfonate in meristematic cells of Allium cepa, as well as to describe its mode of action. Anti-mutagenicity experiments were carried out with 3 different concentrations of AER, which alone showed no mutagenic effects. In antimutagenicity experiments, AER showed chemopreventive activity in cultured meristematic cells of A. cepa against exposure to methylmethane sulfonate. Additionally, post-treatment and simultaneous treatment using pre-incubation protocols were the most effective. Evaluation of different protocols and the percent reduction in DNA indicated bioantimutagenic as well desmutagenic modes of action for AER. AER may be chemopreventive and antimutagenic. PMID:25501210

  14. AISLAMIENTO Y CARACTERIZACIÓN DE CEPAS DE Staphylococcus ENTEROTOXIGÉNICOS AISLADOS DE QUESOS EN BOGOTA

    OpenAIRE

    María Vanegas L; Lina González G; Aida Martínez L; Francisco Buitrago

    2008-01-01

    Objetivo. Caracterizar cepas de Staphylococcus aureus enterotoxigénicos provenientes de quesos distribuidos en supermercados, tiendas y en ventas callejeras en la ciudad de Bogota, Colombia. Materiales y métodos. Se ecolectaron muestras de quesos provenientes de tiendas, supermercados y ventas callejeras. Se detectó la presencia del gen para enterotoxina A usando un set de primers reportado en estudios previos. Un total de 50 quesos fueron analizados, 13 comercializados en tien...

  15. In Vitro Study of Berberis vulgaris, Actinidia deliciosa and Allium cepa L. Antibacterial Effects on Listeria monocytogenes

    OpenAIRE

    Anzabi Younes

    2015-01-01

    Objective: One control method of pathogenic microorganisms is using synthetic chemical preservatives and antibiotics. Because of being generally recognized as safe, antibacterial compounds with organic origin are considered important for health. This study was done in order to investigate the antibacterial effects of methanol extracts of the Berberis vulgaris (Barberry), Actinidia deliciosa (Kiwi) and Allium cepa L. (Onions) on the standard strain (ATCC:19114) of Listeria monocytogenes (L. mo...

  16. Lesões cardíacas em ratos wistar inoculados com diferentes cepas do Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    E. Chapadeiro

    1988-09-01

    Full Text Available Ratos albinos Wistar infectados com diferentes inóculos das cepas Y, Colombiana (COL e São Felipe (12SF do Trypanosoma cruzi desenvolveram parasitemia elevada entre 14e21 dias, a qual tomou-se desprezível ou desapareceu completamente ao final da 4ª semana. As lesões do coração foram avaliadas, semiquantitativamente, pelo sistema de "scores", conforme a intensidade e a extensão da inflamação, nas diferentes estruturas do órgão, tendo sido observado que: a na fase inicial (aguda da infecção, os animais mortos espontaneamente ou em conseqüência de acidente anestésico apresentaram cardite de intensidade moderada à acentuada, não havendo diferença em relação às cepas utilizadas; as diferentes estruturas do coração estavam uniformemente comprometidas; b na fase crônica da infecção observou-se cardite degrau leve a moderado e as lesões foram mais freqüentes e intensas quanto maior o inoculo empregado; no entanto, inóculos baixos só produziram lesões quando a cepa utilizada foi a Colombiana. Trombose mural nos átrios e dilatação da ponta do ventrículo esquerdo foram observadas em 20% dos animais, independentemente da cepa. Na fase crônica 15% dos animais apresentaram miocardite crônica com fibrose, associada à hipertrofia das miocélulas. Os AA confirmam ser o rato albino suscetível à infecção chagásica e, portanto, um modelo útil no estudo das manifestações cardíacas da Doença de Chagas.

  17. In Vivo Cytogenotoxicity of Electronic Waste Leachate from Iloabuchi Electronic Market, Diobu, Rivers State, Nigeria on Allium Cepa

    Directory of Open Access Journals (Sweden)

    Bolaji Babatunde

    2015-06-01

    Full Text Available The human and environmental impact of electronic waste is increasing due to its careless disposal. Cytogenotoxicity of electronic waste from Iloabuchi electronic market, Diobu, Rivers State was investigated using the Allium cepa bioassay comprised of the root elongation and chromosome aberration tests. Leachate samples of e-waste analysed were above maximum permissible limits. Toxicity to root growth of A. cepa was evaluated at concentrations of 5%, 10%, 25%, 50%, and 100% showed root growth inhibition at all concentrations of the samples compared to the control and root growth inhibition was concentration dependent. An effective concentration (EC50 at which root growth amounted to 50 % of control for the sample was 37.5%. Various morphological defects of the onion roots were observed including short, crochet roots, C-tumor roots and severe toxic effects where no growth was observed. In the in vivo genotoxity assay, all samples lowered the frequency of mitotic cells in the meristematic region of the roots at statistically significant levels (P < 0.05 compared to the control and mitotic inhibition was also concentration dependent. There was significant induction of aberrations at all concentrations tested compared to control. The high metal content of the e-waste leachate may be responsible for observed cytotoxicity in A. cepa roots cells.

  18. Caracterización de las glicoproteínas de una cepa de virus respiratorio sincicial aislada en Cali.

    Directory of Open Access Journals (Sweden)

    Beatriz Parra

    2009-10-01

    Full Text Available Se empleó un aislado de virus respiratorio sincicial de un niño de dos meses de edad que presentó el primer episodio de infección aguda en un estudio longitudinal efectuado en Cali (1986-1990, para caracterizar molecular y antigénicamente las glicoproteínas virales que son importantes en los mecanismos de inmunopatogénesis en la infección respiratoria aguda generada por este tipo de virus. La caracterización electroforética de proteínas radiomarcadas in vitro con [3H]-Glucosamina permitió evidenciar las bandas de 98, 70, 30 kd como glicoproteínas que hacen parte de la envoltura del virus. La gp 70 es importante en la inmunopatogénesis porque aparece como efecto de protección de tipo IgG transmitida pasivamente por la madre. Se pudieron localizar dos sitios para la proteasa V8 en la gp70 aislada de ambas cepas. La F1 es una de las subunidades comprometidas en la generación de una respuesta inmune de tipo neutralizante determinada en sueros de la fase aguda y en hiperinmunes de conejo. Se demostró la similitud antigénica y estructural de la cepa Cali-0015 con la cepa de referencia Long.

  19. La cepa de yogur en leche de vaca y cabra como suplemento en corderos de levante

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    Nubia E. Flechas-F.

    2011-02-01

    Full Text Available La  obtención de  productos pecuarios  inocuos para la salud humana cobra cada vez más fuerza. Por esta razón surge la tendencia al empleo de probióticos  que  administrados  a  los  animales provocan  efectos  benéficos  mediante modificaciones en  la población microbiana de su tracto digestivo. Se realizó un estudio con 25 corderos en etapa de  levante, con el  fin de evaluar el  efecto  de  el  uso  de  la  cepa  de  yogur (Lactobacillus  bulgaricus  y  Streptococcus thermophylus  preparado  en  leche  de  vaca  y leche de cabra sobre el crecimiento y  la ganancia de peso, con una duración de 30 días, la dieta estuvo  conformada  por  forraje  a  voluntad  y suplementación  con maíz  y  concentrado.  Los tratamientos  fueron:  yogur a base de  leche de vaca, dosis de 10 y 20 cm3; yogur a base de  leche de cabra, dosis 10 y 20 cm3 y control agua como placebo, 10 cm3. Se suministro  la cepa cada 3 días  y  se  pesaron  los  animales  una  vez  por semana, se realizó química sanguínea al inicio y al  final del ensayo. El peso para  los diferentes

  20. Diferenciação de cepas de Candida albicans pelo sistema killer

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    Regina Celia Cândido

    1995-12-01

    Full Text Available Foi estudado o efeito killer de 9 cepas padrão de leveduras sobre 146 amostras de Candida albicans isoladas dos seguintes espécimes clínicos: mucosa bucal, fezes, lavado brônquico, escarro, secreção vaginal, urina, lesão de pele, lesão de unha e sangue. Usando este sistema foi possível diferenciar 23 biotipos de C. albicans. Os biotipos 211, 111 e 811 foram os mais freqüentemente isolados. A maioria das amostras de C. albicans (98,6% foi sensível a pelo menos uma ou mais das 9 cepas killer. Empregando- se este sistema foi possível demonstrar que 2 pacientes albergavam mesmo biotipo killer, respectivamente, 111 e 211, em diferentes espécimes clínicos, e em outro paciente, o mesmo biotipo (211 foi isolado de hemoculturas realizadas em ocasiões distintas. O uso do sistema killer para diferenciar os tipos entre as espécies de leveduras patogênicas, pode ser um método útil para estabelecer a eventual fonte de infecção, constituindo uma ajuda valiosa para o controle e vigilância de infecções nosocomiais causadas por leveduras.The authors studied the killer effect of nine standard strains of yeasts on 146 samples of Candida albicans isolated from the following clinical specimens: oral mucosa, feces, bronchial wash, sputum, vaginal secretion, urine, skin lesion, nail lesion and blood. Using this system it was possible to differentiate 23 biotypes of Candida albicans. The biotypes 211, 111 and 811 were most frequently isolated. Most of the samples of C. albicans (98.6% were sensitive to at least one or more of the nine killer strains. Using the killer system it was possible to show that two patients harbored the same killer biotypes, 111 and 211, respectively, in different clinical specimens and another patient harbored the same biotype (211 in blood cultures effected in different ocasions. The utilization of the killer system to differentiate types among species of pathogenic yeasts can be a useful method to stablish the eventual

  1. Dichlorophen and Dichlorovos mediated genotoxic and cytotoxic assessment on root meristem cells of Allium cepa

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    Sibhghatulla Shaikh

    2012-06-01

    Full Text Available Plants are direct recipients of agro – toxics and therefore important materials for assessing environmental chemicals for genotoxicity. The meristematic mitotic cell of Allium cepa is an efficient cytogenetic material for chromosome aberration assay on environmental pollutants. Onion root tips were grown on moistened filter paper in petri dish at room temperature. Germinated root tips were then exposed to three concentrations of each pesticide for 24 h. About 1 – 2 mm length of root tip was cut, fixed in cornoy’s fixative, hydrolyzed in warm 1 N HCL, stained with acetocarmine and squashed on glass slide. About 3000 cells were scored and classified into interphase and normal or aberrant division stage. Cytotoxicity was determined by comparing the mitotic index (MI of treated cells with that of the negative control. The MI of cells treated with Dichlorophen and Dichlorovos at one or more concentration was half or less than that of control are said to be cytotoxic. Genotoxicity was measured by comparing the number of cells/1000 in aberrant division stages at each dose with the negative control using Mann – Whitney U test. Both Dichlorophen and Dichlorovos are genotoxic at higher concentrations i.e. 0.001%, 0.002% and 0.028%, 0.056% inducing chromosome fragment, chromosome lagging and bridges, stick chromosome and multipolar anaphase.

  2. Biomphalaria straminea no Peru e sua suscetibilidade a cepas brasileiras de Schistosoma mansoni

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    C.A. Cuba Cuba

    1977-12-01

    Full Text Available Em Maio de 1973, um dos autores (C.A.C. coletou na localidade de Imacita, Província de Bagua, Departamento de Amazonas, vários espécimes de Biomphalaria straminea (Dunker, 1848, uma espécie que, até então, não havia sido assinalada no Peru. Descendentes destes indivíduos foram submetidos a provas de suscetibilidade às cepas BH e SJ de Schistosoma mansoni que, em condições naturais, evoluem em B. glabrata de Belo Horizonte e B. tenagophila de São José dos Campos, respectivamente. Oitenta espécimens foram expostos à cepa BH dos quais em 13 ou 16,2% a infecção evoluiu caracteristicamente até a formação de esporocistos secundários sem haver, contudo, eliminação de cercárias, mesmo no indivíduo que apresentou uma sobrevivência de 88 dias após a exposição. Não se verificou cura espontânea neste lote. Entre as 40 B. straminea expostas à cepa SJ 9 ou 22,5% infectaram-se, sendo que apenas duas eliminaram poucas cercárias aos 57 e 77 dias após a exposição, por dois dias consecutivos, tendo uma morrido e uma se curado espontaneamente. A cura espontânea do parasitismo foi notado em mais dois indivíduos, nos quais a infecção foi observada através da concha. Cortes histológicos seriados de 9 caramujos, expostos individualmente a 50 miracídios da cepa BH e fixados entre 6 e 120 horas após a exposição, mostraram esporocistos em desenvolvimento e esporocistos invadidos por amebócitos, sem formação de granulomas por parte do hospedeiro, fato assinalado em caramujos suscetíveis. A população estudada comportou-se experimentalmente de modo semelhante a outras populações de B. straminea testadas em laboratório, isto é, com baixa suscetibilidade, embora tal comportamento não afaste a possibilidade dela vir a manter o ciclo do parasita em sua área de distribuição.In May 1973 one of the Authors (C.A.C. collected specimens of Biomphalaria straminea (Dunker 1848 at imacita, Bagua Province, Amazonas, Pem. This

  3. De Novo Transcriptome Analysis of Allium cepa L. (Onion Bulb to Identify Allergens and Epitopes.

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    Hemalatha Rajkumar

    Full Text Available Allium cepa (onion is a diploid plant with one of the largest nuclear genomes among all diploids. Onion is an example of an under-researched crop which has a complex heterozygous genome. There are no allergenic proteins and genomic data available for onions. This study was conducted to establish a transcriptome catalogue of onion bulb that will enable us to study onion related genes involved in medicinal use and allergies. Transcriptome dataset generated from onion bulb using the Illumina HiSeq 2000 technology showed a total of 99,074,309 high quality raw reads (~20 Gb. Based on sequence homology onion genes were categorized into 49 different functional groups. Most of the genes however, were classified under 'unknown' in all three gene ontology categories. Of the categorized genes, 61.2% showed metabolic functions followed by cellular components such as binding, cellular processes; catalytic activity and cell part. With BLASTx top hit analysis, a total of 2,511 homologous allergenic sequences were found, which had 37-100% similarity with 46 different types of allergens existing in the database. From the 46 contigs or allergens, 521 B-cell linear epitopes were identified using BepiPred linear epitope prediction tool. This is the first comprehensive insight into the transcriptome of onion bulb tissue using the NGS technology, which can be used to map IgE epitopes and prediction of structures and functions of various proteins.

  4. Therapeutic Effects of Allium sativum and Allium cepa in Schistosoma mansoni experimental infection

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    Mona Mohamed Mantawy

    2011-06-01

    Full Text Available The effects of both garlic (Allium sativum and onion (Allium cepa on some biochemical parameters in Schistosoma mansoni infected mice individually and mixed either with or without the currently used drug, praziquantel (PZQ were investigated. These involved some immunological parameters, namely IgM, IgG, interleukins 2 and 6 (IL-2 and 6 and tumor necrosis factor (TNF-α, some antioxidant enzymes [catalase, superoxide dismutase (SOD and glutathione peroxidase (GPX]. In addition, parasitological and histopathological investigations were performed. No changes were observed in the normal control mice treated with dry extract of onion or garlic, individually or mixed, with or without PZQ, compared to the normal healthy control group. Infection with S. mansoni showed an increase in IgG, IgM, IL-2, IL-6, TNF-α and catalase enzyme, accompanied with a decrease in GPX and SOD antioxidant enzyme activities. Remarkable amelioration was noticed in the levels of all the measured parameters in S. mansoni infected mice after administration of the studied extracts. Moreover a significant reduction in worm burden, hepatic and intestinal eggs and oogram count was noticed which was reflected in normalization of liver architecture.

  5. Leaf cavity CO2 concentrations and CO2 exchange in onion, Allium cepa L.

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    Byrd, G T; Loboda, T; Black, C C; Brown, R H

    1995-06-01

    Onion (Allium cepa L.) plants were examined to determine the photosynthetic role of CO2 that accumulates within their leaf cavities. Leaf cavity CO2 concentrations ranged from 2250 μL L(-1) near the leaf base to below atmospheric (CO2 concentrations with minimum values near midday and maximum values at night. Conductance to CO2 from the leaf cavity ranged from 24 to 202 μmol m(-2) s(-1) and was even lower for membranes of bulb scales. The capacity for onion leaves to recycle leaf cavity CO2 was poor, only 0.2 to 2.2% of leaf photosynthesis based either on measured CO2 concentrations and conductance values or as measured directly by (14)CO2 labeling experiments. The photosynthetic responses to CO2 and O2 were measured to determine whether onion leaves exhibited a typical C3-type response. A linear increase in CO2 uptake was observed in intact leaves up to 315 μL L(-1) of external CO2 and, at this external CO2 concentration, uptake was inhibited 35.4±0.9% by 210 mL L(-1) O2 compared to 20 mL L(-1) O2. Scanning electron micrographs of the leaf cavity wall revealed degenerated tissue covered by a membrane. Onion leaf cavity membranes apparently are highly impermeable to CO2 and greatly restrict the refixation of leaf cavity CO2 by photosynthetic tissue. PMID:24307095

  6. Screening antibiotics: industrial research by CEPA and Merck in the 1950s.

    Science.gov (United States)

    Jesús Santesmases, María

    2011-01-01

    This article is an account of a screening programme in search of new antibiotics established by CEPA (Comparñia Española de Penicilinas y Antibióticos) and Merck in Madrid in 1954. An exploration of the genealogy for such a programme, its narratives and practices, shows that the main inspiration for this programme was the factory system of production, on the one hand, and Selman Waksman's research agenda on microorganisms of the soil, on the other. In this article, the relationship between industrial production of antibiotics and the research program aimed at identifying new candidate drugs is examined. I suggest that this screening program in search of new antibiotics was organised like industrial manufacturing. The research objects and tools came, both materially and conceptually, from industrial production: a line of artisanship put together in order to obtain a product with the collaboration of every member of the production line. Following the style developed by Selman Waksman in Rutgers, the screening program evaluated samples manually, and the microbiological skills were enhanced with every test. The Madrid team's practice of applying instructions for use led to circulation of knowledge and practices, including research material and microbiological methods. PMID:22332466

  7. Conservación de cepas de Candida utilis en agua destilada estéril

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    Aidín Martínez

    2009-01-01

    Full Text Available Algunos métodos han sido utilizados para el mantenimiento de la colección de levaduras. La elección de uno u otro tiene como objetivo garantizar la estabilidad de los cultivos; teniendo en cuenta las dimensiones y posibilidades económicas de la colección. En este trabajo se empleó la preservación de levaduras en agua destilada estéril por ser un método sencillo, económico, seguro y, capaz de garantizar la viabilidad de los cultivos por un período prolongado. Se conservaron 8 cepas de Candida utilis y se aseguró el 100% de supervivencia de las mismas en dicho sustrato durante tres años, a la vez que no se observaron cambios en las características fisiológicas y morfológicas de los cultivos. Palabras clave: preservación, levaduras, agua destilada.

  8. Establecimiento de un medio de cultivo sumergido para una cepa nativa de un hongo Poliporal

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    Peña Serna Carolina

    2006-07-01

    Full Text Available Se evaluó el efecto de dos velocidades de agitación (80 y 100 rpm, dos fuentes de carbono (glucosa y sacarosa y tres pH iniciales (5.5, 6.0 y 6.5 sobre la producción de fenoles totales, la actividad antioxidante, el crecimiento micelial y el consumo de sustrato de una cepa nativa de un hongo perteneciente al orden Poliporal en cultivo sumergido.El mayor crecimiento micelial se obtuvo al día 3 con un valor de 10 g/L a una velocidad de agitación de 80 rpm, sacarosa como fuente de carbono y pH inicial 5.5. La máxima producción de fenoles y actividad antioxidante se presentó este mismo día, alcanzando valores de 0.18 g GAE/L y 0.28 TEAC (mM/mL, respectivamente, para cualquiera de las dos velocidades de agitación evaluadas, con glucosa como fuente de carbono y con pH inicial 6.0 y/o 6.5 para fenoles y pH inicial 5.5 para actividad antioxidante.Palabras claves: actividad antioxidante, crecimiento micelial, cultivo sumergido, fenoles.

  9. Evaluation of the cytogenotoxicity of textile effluents using Allium cepa L.

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    Sandro Barbosa

    2011-08-01

    Full Text Available The cytotoxic and genotoxic potential of the raw (EB and treated (ET effluents of two textile mills located in south of Minas Gerais State that have their effluents treated at the same Effluent Treatment Plant was investigated using the Allium cepa test system. Cytotoxicity was evaluated by the root elongation and mitotic index (MI endpoints and the genotoxicity was assessed by de determination of chromosome aberrations (CA.The effluent samples were tested at the concentrations 0 (ultrapure water, 25, 50, 75, and 100 % (v/v. A Completely Randomized Design with four replicates of 30 seeds was used. The effluent samples in almost all tested concentrations promoted an increase in root elongation compared to the negative control and this effect was probably related to nutrients levels and organic matter in effluent samples. A lower MI at all concentrations of ET compared to EB. The highest MI was observed at 100% (v/v concentration of both effluents. The highest rates of CA occurred at concentrations 75% (v/v of EB and 100% (v/v of both effluents. The effluent samples showed no cytotoxic effect, but cell division occurred disorderly, leading to increase rate of AC, revealing a genetoxic effect. Improvements in the wastewater treatment are needed to reduce environmental impacts.

  10. Effects of Pterocaulon polystachyum DC. (Asteraceae on onion (Allium cepa root-tip cells

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    Michelle Frainer Knoll

    2006-01-01

    Full Text Available In Brazil leaf infusions of the plant Pterocaulon polystachyum DC (Asteraceae are used to treat digestive problems. We used plants from six P. polystachyum populations to prepare fresh aqueous leaf infusions at the concentration normally used in Brazil (2.5 g L-1 and at twice (5 g L-1 and four times (10 g L-1 this concentration. We rooted onion bulbs in a water control or one of the infusions for 24 h and used the in vivo onion (Allium cepa root-tip cell test to investigate the potential mutagenicity of the infusions by calculating the mitotic index for the control and the experimental treatments and comparing them using the Chi-squared test (chi2, p = 0.05. There was a highly significant decrease in the mitotic index of root-tip cells treated with infusion as compared to those exposed to water only. These results indicate that P. polystachyum infusions present cytotoxic and anti-proliferative activity and therefore have therapeutic potential.

  11. Viabilidad y colonización de la Cepa Vacunal Vibrio Cholerae 638 liofilizada en dos formulaciones y almacenada a diferentes temperaturas

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    Herminia Delgado

    2005-01-01

    Full Text Available Una vacuna efectiva contra el cólera debe ser suministrada por vía oral. En este tipo de vacunas es muy importante conservar el microorganismo a concentraciones conocidas por períodos prolongados. La liofilización es el método ideal para lograr este objetivo, sin embargo, durante este proceso ocurren pérdidas considerables en la viabilidad de los microorganismos, por lo que se deben utilizar sustancias lioprotectoras que minimicen estas pérdidas. La viabilidad de la cepa vacunal y su capacidad de colonización son aspectos importantes para lograr la inmunogenicidad y por tanto la eficacia de la vacuna. Para la realización de este trabajo utilizamos la cepa vacunal 638, Vibrio cholerae O1, El Tor Ogawa, liofilizada en las formulaciones F1 (lactosa, peptona, sorbitol y F9 (leche descremada, peptona, sorbitol. Se estudiaron muestras de lotes liofilizados y almacenados a 8 y -20ºC por períodos de tiempo de 6 meses y 1 año. Al cabo de dichos tiempos, se evaluó la pérdida de viabilidad y la capacidad de colonización de dicha cepa. También se analizó la actividad celulolítica (celA de los productos liofilizados. La viabilidad de la cepa liofilizada en F9 y almacenada a las diferentes temperaturas y tiempos fue ligeramente menor que en la F1. La actividad celA de la cepa vacunal, conservada y almacenada en estas condiciones, fue detectada en el 100% de las colonias analizadas. La cepa 638 colonizó el intestino de la mayoría de los ratones al cabo de las 24h de inoculados, excepto cuando se utilizó la cepa liofilizada en F9 y almacenada a 8ºC durante 1 año. No obstante, a las 120h se alcanzaron los niveles máximos de colonización observados para esta cepa en estudios previos sin liofilizar. Teniendo en cuenta todo lo anterior, ambas formulaciones mantienen, en niveles aceptables, la viabilidad, y la capacidad colonizadora de la cepa vacunal 638, almacenada hasta 1 año.

  12. Resistencia antimicrobiana de cepas de Bartonella bacilliformis procedentes de regiones endémicas de la Enfermedad de Carrión en EL Perú

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    Giovanna Mendoza-Mujica

    2015-10-01

    Full Text Available Objetivos. Evaluar la susceptibilidad antimicrobiana in vitro a cloranfenicol (CHL y ciprofloxacino (CIP de cepas de Bartonella bacilliformis procedentes de áreas endémicas de la enfermedad de Carrión (EC en el Perú, mediante tres métodos de laboratorio. Materiales y métodos. Se evaluó la susceptibilidad antimicrobiana a CHL y CIP de 100 cepas de Bartonella bacilliformis, los aislamientos procedieron de pacientes de los departamentos de Ancash, Cusco, Cajamarca, Lima y La Libertad; las cepas se evaluaron mediante: disco difusión, E-Test y dilución en agar. Resultados. El 26% de las cepas de Bartonella bacilliformis evaluadas, presentaron resistencia a CIP y 1% a CHL. Se obtuvieron patrones similares de sensibilidad/resistencia antimicrobiana en los tres métodos utilizados. Conclusiones. Las cepas de Bartonella bacilliformis circulantes en el Perú, presentan elevados niveles de resistencia in vitro a CIP, por lo que se recomienda ampliar la investigación sobre la utilización del fármaco en los esquemas de tratamiento de la EC. Los métodos de E-test y disco difusión resultaron más convenientes para la evaluación de la susceptibilidad antimicrobiana in vitro del microorganismo

  13. Streptococcus pneumoniae: estudo das cepas isoladas de liquor Streptococcus pneumoniae: a study of strains isolated from cerebrospinal fluid

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    Ataiza C. Vieira

    2007-02-01

    Full Text Available OBJETIVO: Determinar a freqüência dos sorotipos capsulares e a susceptibilidade antimicrobiana de cepas de Streptococcus pneumoniae, assim como dar suporte à indicação de vacinas disponíveis e ao uso de antimicrobianos. MÉTODOS: Neste estudo retrospectivo, foram adotadas metodologias padronizadas para identificar, sorotipar e determinar a susceptibilidade à penicilina, cefotaxima e vancomicina. O estudo foi realizado com cepas de pneumococo isoladas de liquor em pacientes atendidos nos hospitais públicos e em três hospitais particulares do Distrito Federal no período de janeiro de 1995 a dezembro de 2004. A identificação e a determinação de susceptibilidade a antimicrobianos foi realizada no Laboratório Central de Saúde Pública no Distrito Federal. A sorotipagem foi realizada no Instituto Adolfo Lutz. RESULTADOS: Foram isoladas 232 cepas de pneumococo, compreendendo 126 cepas (54,31% de pacientes do sexo masculino. A idade dos pacientes variou de 0 a 62 anos, sendo agrupados em faixas etárias de 0 a 5, 6 a 17, 18 a 50 e acima de 50 anos. Identificaram-se 36 sorotipos distintos. Desses destacaram-se oito: 14, 6B, 18C, 5, 19F, 23F, 9V e 6A. O teste de oxacilina caracterizou 67 cepas resistentes à penicilina; dessas, 47 foram confirmadas pelo E teste com resistência de nível intermediário. Nenhuma cepa apresentou resistência de alto nível. CONCLUSÃO: A resistência do pneumococo à penicilina apresentou um aumento gradativo nos últimos 10 anos no Distrito Federal. Os sorotipos mais isolados na faixa etária de 0 a 5 anos foram também os mais envolvidos na resistência à penicilina, e estão incluídos na vacina 7-valente.OBJECTIVE: To determine the frequency of capsular serotypes and the antimicrobial susceptibility of strains of Streptococcus pneumoniae, as well as to provide recommendations on the use of available vaccines and antimicrobial drugs. METHODS: In this retrospective study, standard procedures were followed

  14. The effect of oleander glycosides on the germination of pollen grains and the mitosis of the generative nucleus in Tradescantia bracteata Small and Allium cepa L.

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    J. A. Tarkowska

    2015-05-01

    Full Text Available The effect of water solution of a mixture of glycosides from oleander (Nerium oleander L. on the germination of pollen grains and on the mitosis of the generative nucleus in Tradescantia bracteata Small and Allium cepa L. has been studied. An inhibition of the germination and of the growth of pollen tubes was observed, proportionally to the concentration of glycosides. The pollen grains of A. cepa are more sensitive. The disturbances in mitosis lead to the formation of two or more uneven-sized doughter nuclei, or to the formation of restitution nuclei. These anomalies are more numerous in T. bracteata. From these results d t appears that pollen grains of A. cepa are characterized by a generally high physiological sensitivity and a small mitotic sensitivity, wheras for T. bracteata the opposite is true.

  15. Strip Tillage and Early-Season Broadleaf Weed Control in Seeded Onion (Allium cepa

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    Sarah Gegner-Kazmierczak

    2016-03-01

    Full Text Available Field experiments were conducted in 2007 and 2008 near Oakes, North Dakota (ND, USA, to evaluate if strip tillage could be incorporated into a production system of seeded onion (Allium cepa to eliminate the standard use of a barley (Hordeum vulgare companion crop with conventional, full width tillage, yet support common early-season weed control programs. A split-factor design was used with tillage (conventional and strip tillage as the main plot and herbicide treatments (bromoxynil, DCPA, oxyfluorfen, and pendimethalin as sub-plots. Neither tillage nor herbicide treatments affected onion stand counts. Common lambsquarters (Chenopodium album densities were lower in strip tillage compared to conventional tillage up to three weeks after the post-emergence applied herbicides. In general, micro-rate post-emergence herbicide treatments provided greater early-season broadleaf weed control than pre-emergence herbicide treatments. Onion yield and grade did not differ among herbicide treatments because the mid-season herbicide application provided sufficient control/suppression of the early-season weed escapes that these initial weed escapes did not impact onion yield or bulb diameter. In 2007, onion in the strip tillage treatment were larger in diameter resulting in greater total and marketable yields compared to conventional tillage. Marketable onion yield was 82.1 Mg ha−1 in strip tillage and 64.9 Mg ha−1 in conventional tillage. Results indicate that strip tillage use in direct-seeded onion production was beneficial, especially when growing conditions were conducive to higher yields and that the use of strip tillage in onion may provide an alternative to using a companion crop as it did not interfere with either early-season weed management system.

  16. Comparison of the ability of fifteen onion (Allium cepa L. cultivars to accumulate nitrates

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    Renata Wojciechowska

    2014-04-01

    Full Text Available The aim of a two-year study was to characterise selected Allium cepa L. genotypes with regard to their ability to accumulate nitrates in bulbs as well as to search for a possible relation between NO3- concentration and dry matter content. Fifteen cultivars of edible onion, mostly of long-day genotype with different growing periods, bulb size and skin colour, were taken for the experiment. Seeds of particular cultivars were obtained from the following seed companies: Spójnia Nochowo (‘Labrador’, ‘Takstar F1’,‘Tęcza’, ‘Warna’, ‘Zorza’, Polan (‘Polanowska’, ‘Topolska’, PlantiCo Gołębiew (‘Alibaba’, ‘Efekt’, ‘Kristine’, ‘Niagara F1’,and PlantiCo Zielonki (‘Bila’, ‘Irka’, ‘Wenta’, ‘Zeta’. Plants produced from seedlings were grown in the experimental field of the University of Agriculture in Kraków. After crop harvesting and additional drying, nitrate and dry matter content in bulbs of all cultivars were measured. The following cultivars: ‘Efekt’, ‘Labrador’ and red-skinned ‘Wenta’, were characterized by the lowest ability to accumulate NO3- in bulbs. The highest nitrate content was noted in bulbs of ‘Takstar F1’ (a very early-season cultivar, followed by ‘Bila’ and ‘Tęcza’. A weak, yet statistically significant negative correlation between nitrate and dry matter content was observed. The highest dry matter content was determined in bulbs of white-skinned ‘Alibaba’, while the lowest – in brown-skinned ‘Labrador’.

  17. Transcriptome Analysis of Sucrose Metabolism during Bulb Swelling and Development in Onion (Allium cepa L.)

    Science.gov (United States)

    Zhang, Chunsha; Zhang, Hongwei; Zhan, Zongxiang; Liu, Bingjiang; Chen, Zhentai; Liang, Yi

    2016-01-01

    Allium cepa L. is a widely cultivated and economically significant vegetable crop worldwide, with beneficial dietary and health-related properties, but its sucrose metabolism is still poorly understood. To analyze sucrose metabolism during bulb swelling, and the development of sweet taste in onion, a global transcriptome profile of onion bulbs was undertaken at three different developmental stages, using RNA-seq. A total of 79,376 unigenes, with a mean length of 678 bp, was obtained. In total, 7% of annotated Clusters of Orthologous Groups (COG) were involved in carbohydrate transport and metabolism. In the Kyoto Encyclopedia of Genes and Genomes (KEGG) database, “starch and sucrose metabolism” (147, 2.40%) constituted the primary metabolism pathway in the integrated library. The expression of sucrose transporter genes was greatest during the early-swelling stage, suggesting that sucrose transporters (SUTs) participated in sucrose metabolism mainly at an early stage of bulb development. A gene-expression analysis of the key enzymes of sucrose metabolism suggested that sucrose synthase, cell wall invertase, and invertase were all likely to participate in the hydrolysis of sucrose, generating glucose, and fructose. In addition, trehalose was hydrolyzed to two molecules of glucose by trehalase. From 15 to 40 days after swelling (DAS), both the glucose and fructose contents of bulbs increased, whereas the sucrose content decreased. The growth rate between 15 and 30 DAS was slower than that between 30 and 40 DAS, suggesting that the latter was a period of rapid expansion. The dataset generated by our transcriptome profiling will provide valuable information for further research. PMID:27713754

  18. Potency of Allium sativum and Allium cepa Oils against Schistosoma mansoni Infection in Mice

    Directory of Open Access Journals (Sweden)

    Nadia S. Metwally

    2006-06-01

    Full Text Available Introduction: It has been reported that garlic (Allium sativum and onion (Allium cepa are used all over the world in different diseases, such as infections, injuries, gastrointestinal dysfunctions and cardiovascular diseases. Therefore, our aim in this work was to study the ability of garlic and onion oils to offset the infectivity as well as the metabolic disturbances induced by Schistosoma mansoni parasitism. Methods: The two current drugs were given in a dosage of 5ml / kg body weight/ day. Three aspects of drug action were investigated, the effect on S. mansoni infection, the effect on liver functions, and on liver metabolism. The parasitological investigation included worm burden and ova count. Results: Serum biochemical analysis of infected mice revealed a significant increase in the levels of aspartate aminotransferase (AST, alanine aminotransferase (ALT , ­ glutamyltransferase (GGT , alkaline phosphatase ( ALP, acid phosphatase (AP, while a decrease in glucose, total lipids total cholesterol, high - and low- density lipoproteins cholesterol (HDL and LDL, triglycerides, total proteins and albumin was observed. Liver tissue analysis of infected animals showed a marked increase in L- hydroxyproline (HP concentration and xanthine oxidase (XO activity accompanied with a reduction in total adenosinetriphosphatase (ATPase and phosphofructokinase (PFK enzymatic activities. Treatment with either garlic or onion oils greatly normalized liver function enzymes and variably improved the other parameters with a noticeable reduction in worm burden and ova count. Conclusions: It could be concluded that garlic or onion may play a role against the metabolic disturbances caused by S. mansoni infection, owing to an effect which may be induced by improving the immunological host system and their antioxidant activities

  19. Hypersensitivity of Allium cepa seedling roots to X-rays for production of micronuclei

    Energy Technology Data Exchange (ETDEWEB)

    Hori, Takayoshi [Kyoritsu Junior High School, Tokyo (Japan); Hanmoto, Hidehiro; Fujishige, Ikuko; Inoue, Toshihiro; Taniguchi, Kenji; Itoh, Tetsuo; Fujikawa, Kazuo; Yonezawa, Yoshihiko

    1995-10-01

    Seedling roots of onion (Allium cepa) were irradiated with various doses of X-rays. Following irradiation, the roots were incubated at 23-25degC for 24 hr, i.e., approximate time for one mitotic cycle, and then fixed, stained and macerated in a 7:3 mixture of acetic dahlia (prepared by dissolving a 0.5 g sample of dahlia violet into 100 ml of 30% acetate) and 1 N HCl for 10-15 min. Terminal 1-2 mm of the root tips were squashed on slides, one root each, and microscopically inspected for the presence of more than one nucleus in the cells. The additional nuclei, which were smaller than the normal, were scored as micronuclei. The frequency of micronuclei increased with dose over the control level ({approx}0.2x10{sup -3}) to a high level of 140x10{sup -3} at 1 Gy. The frequency recorded at 1 Gy was about two fold higher as compared with the frequency reported by Evans et al. (1959) for micronuclei induced by {gamma}-rays at a comparable dose in the root tip cells of Vica faba seedlings, probably reflecting relatively higher DNA content per cell in Allium somatic cells. We thus may conclude that root-tip meristematic cells of Allium seedlings are hypersensitive to the induction of micronuclei by X-rays. The Allium micronucleus assay may be useful as a system not only for quantitating chromosome damage by low-level radiation but also for detecting environmental mutagens. (author).

  20. Genotoxic evaluation of infusions of Urera baccifera leaves and roots in Allium cepa cells

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    Amanda L. Gindri

    2015-04-01

    Full Text Available Context: The aqueous extracts of Urera baccifera Wedd. leaves and roots are used to inflammatory and infectious diseases in Brazilian folk medicine. Oxalic acid, a substance co-related with toxicity and stinging, was already quantified in this plant. Aims: To evaluate the action of leaves and roots infusions (1, 30, 75 g/L and the oxalic acid standard on mitosis as indicative of presumably antimitotic and genotoxic actions, using the Allium cepa test. Methods: Oxalic acid was quantified in the roots and leaves infusions by High-performance liquid chromatography (HPLC-DAD, with the mobile phase of 25 mM phosphate buffer (pH 2.5: acetonitrile at 95:5 (v/v. To the genotoxicity test, onion bulbs were used. After the rootlets germination, each bulb was submitted for 24 h of the individual treatments. Were analyzed 1000 cells per bulb, in a total of 5000 cells per treatment. Results: Results showed that all concentrations of roots infusions induced chromosomes abnormalities, except for the highest, that caused a substantial inhibition in the mitosis, precluding to be observed abnormalities. In the leaves infusions, only the two higher concentrations caused the highest values of damage in the cellular cycle. The oxalic acid also caused abnormalities in the mitosis, and may be considered responsible by part of the genotoxic action of U. baccifera. Conclusions: Oxalic acid can be responsible by part of the chromosomal abnormalities caused by U. baccifera, although, there must have more metabolites that evoke the same effect promoting the genotoxic effect of this nettle.

  1. Identification of pathogenicity-related genes in Fusarium oxysporum f. sp. cepae.

    Science.gov (United States)

    Taylor, Andrew; Vágány, Viktória; Jackson, Alison C; Harrison, Richard J; Rainoni, Alessandro; Clarkson, John P

    2016-09-01

    Pathogenic isolates of Fusarium oxysporum, distinguished as formae speciales (f. spp.) on the basis of their host specificity, cause crown rots, root rots and vascular wilts on many important crops worldwide. Fusarium oxysporum f. sp. cepae (FOC) is particularly problematic to onion growers worldwide and is increasing in prevalence in the UK. We characterized 31 F. oxysporum isolates collected from UK onions using pathogenicity tests, sequencing of housekeeping genes and identification of effectors. In onion seedling and bulb tests, 21 isolates were pathogenic and 10 were non-pathogenic. The molecular characterization of these isolates, and 21 additional isolates comprising other f. spp. and different Fusarium species, was carried out by sequencing three housekeeping genes. A concatenated tree separated the F. oxysporum isolates into six clades, but did not distinguish between pathogenic and non-pathogenic isolates. Ten putative effectors were identified within FOC, including seven Secreted In Xylem (SIX) genes first reported in F. oxysporum f. sp. lycopersici. Two highly homologous proteins with signal peptides and RxLR motifs (CRX1/CRX2) and a gene with no previously characterized domains (C5) were also identified. The presence/absence of nine of these genes was strongly related to pathogenicity against onion and all were shown to be expressed in planta. Different SIX gene complements were identified in other f. spp., but none were identified in three other Fusarium species from onion. Although the FOC SIX genes had a high level of homology with other f. spp., there were clear differences in sequences which were unique to FOC, whereas CRX1 and C5 genes appear to be largely FOC specific.

  2. Eficiencia biológica de cepas nativas de Trichoderma spp., en el control de Sclerotium rolfsii Sacc., en cacahuate

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    A. C. Michel-Aceves

    2013-01-01

    Full Text Available En el control de Sclerotium rolfsii Sacc., se evaluó el efecto antagónico de aislados nativos de Trichoderma spp., bajo condiciones in vitro y de invernadero, en la zona Norte del estado de Guerrero. Se obtuvieron doce aislados nativos de Trichoderma spp. (dos de Santa Teresa y diez de Tlaxmalac, Gro., de los cuales se seleccionaron seis (Tcn-4, Tcn-5, Tcn-6, Tcn-7, Tcn-8 y Tcn-11 mediante el método del papel celofán. En condiciones in vitro, el porcentaje de inhibición varió desde 10 a 94.40%; registrándose mediante la técnica de cultivos apareados el antagonismo clase dos en el aislado Tcn-11; en estas condiciones, inhibió el crecimiento del fitopatógeno y evitó su desarrollo en el 80% de la superficie del medio en la caja de Petri. En condiciones de invernadero se evaluó la cepa nativa Tcn-11 identificada morfológica y genéticamente como T. harzianum Rifai y se comparó con una cepa de la colección (Thzcf-12 y un fungicida comercial en tres tiempos de inoculación. El fitopatógeno S. rolfsii no fue suficientemente agresivo para ocasionar la muerte de la planta de cacahuate; sin embargo, se observaron efectos negativos en su desarrollo y producción de semillas. Las cepas Tcn-11 y Thzcf-12 fueron capaces de contribuir al desarrollo de la planta de cacahuate y ayudar a protegerla de la infección de S. rolfsii de manera más eficiente que el fungicida pentacloro nitrobenceno (PCNB.

  3. Selección de cepas de Shigella sonnei para el desarrollo de una vacuna efectiva contra la shigellosis

    Directory of Open Access Journals (Sweden)

    Olga M. Martínez

    2008-12-01

    Full Text Available En el Instituto Finlay se desarrolló una metodología de trabajo que contribuyó a la selección de cepas de Shigella sonnei como posibles candidatos vacunales contra la shigellosis. Las cepas investigadas, donadas por el Centro Provincial de Higiene y Epidemiología de Ciudad de La Habana, se caracterizaron según los métodos convencionales. La identificación del serogrupo y serotipo se realizó por aglutinación en láminas portaobjetos con antisueros comerciales; mientras que para el estudio de la susceptibilidad antimicrobiana se utilizó el DIRAMIC 10, un equipo semiautomatizado que proporcionó los resultados 4 horas después de su realización. Se investigó también la presencia de plásmidos de virulencia, por el crecimiento de Shigella spp. en medio de agar Triptona Soya con Rojo Congo al 0,025%, así como la expresión de las proteínas de la membrana externa en SDS-PAGE; para las pruebas de virulencia y potencia se emplearon los modelos animales (modelo ratón-pulmón y Test de Sereny. Los resultados obtenidos con la metodología utilizada permitieron la selección de la cepa de S. sonnei A-04 como la más adecuada para la obtención del posible candidato vacunal.

  4. Efectividad de cepas rizobianas de frijolbajo diferentes regímenes de fósforo

    Directory of Open Access Journals (Sweden)

    Juliana Mayz Figueroa

    2012-06-01

    Full Text Available Normal 0 21 false false false ES-CO X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;} Título en ingles: Effectiveness of cowpea rhizobial strains under different phosphorus regimes Resumen En Venezuela, el frijol representa una alternativa a la proteína animal, debido a su alto consumo y valor nutritivo, por ello se ha estimulado la implementación de programas para reactivar la economía de los pequeños y medianos productores, a fin de incrementar su producción y así tener mayor disponibilidad de proteína de alta calidad a  bajo costo; de manera que, los estudios encaminados a mejorar su cultivo, son acertados. Se evaluó la efectividad de cepas rizobianas de crecimiento lento (cl y rápido (cr en frijol (Vigna unguiculata (L. Walp. cultivar TC9-6 en varios regímenes de fósforo (0, 20, 40 y 80 kgP2O5 ha-1, con un diseño experimental de bloques al azar con arreglo factorial. Las plantas se cultivaron en 4 kg de suelo de sabana 45 días y las cepas en caldo de levadura y manitol: 5 (cr: JV91 y 10 (cl: JV94 días. La inoculación (2 ml cada vez fue aplicada a la siembra y 6 días más tarde. La utilización de fósforo (40-80 kgP2O5 ha-1 incrementó la nodulación (número, peso seco total e individual de nódulos y favoreció la aparición de nódulos rojos; así mismo, acrecent

  5. Estrategias de identificación de genes de proteasas en una cepa de pseudomonas fluorescens alterante de leche

    OpenAIRE

    Rodrigo Torres, Lidia

    2013-01-01

    La leche es un alimento muy completo nutricionalmente y por ello fácilmente alterable por microorganismos si no se adoptan unas medidas de higiene adecuadas. El análisis de un lote de leche esterilizada comercial alterada reveló la presencia de una cepa de Pseudomonas fluorescens con actividad proteolítica y lipolítica. El objetivo de este trabajo fue diseñar oligonucleótidos y utilizar la técnica de amplificación por PCR (Polymerase Chain Reaction), seguida de secuenciación o de clonación...

  6. Inhibition effect on the Allium cepa L. root growth when using hexavalent chromium-doped river waters.

    Science.gov (United States)

    Espinoza-Quiñones, F R; Szymanski, N; Palácio, S M; Módenes, A N; Rizzutto, M A; Silva, F G; Oliveira, A P; Oro, A C P; Martin, N

    2009-06-01

    The effect of Cr(6+) on Allium cepa root length was studied using both clean and polluted river waters. Seven series of Cr(6+)-doped polluted and non-polluted river waters were used to grow onions. Chromium concentration (Cr(6+)) of 4.2 mg L(-1)(EC(50) value), doped in clean river water caused a 50% reduction of root length, while in organically polluted samples similar root growth inhibition occurred at 12.0 mg Cr(6+) L(-1). The results suggested that there was a dislocation to higher values in toxic chromium concentration in polluted river water due to the eutrophization level of river water.

  7. Comportamento da cepa LE de Schistosoma mansoni, após passagem em hospedeiro humano infectado acidentalmente

    Directory of Open Access Journals (Sweden)

    Neusa Araújo

    1986-12-01

    Full Text Available Uma auxiliar de laboratório infectou-se acidentalmente, com cercárias de Schistosoma mansoni, cepa LE, mantida rotineiramente em nossos laboratórios. Decorridos 5 meses, o exame parasitológico de fezes revelou 108 ovos/g . A pacientefoi tratada com oxamniquine, porém a infecção continuou ativa (6 ovos/g. Foi então obtido o isolado SSF mantido no modelo Biomphalaria glabrata - camundongo albino. Os resultados obtidos no estudo comparativo, entre o isolado SSF e a cepa LE, que lhe deu origem, mostraram que a duração do período pré-patente e o índice de infectividade em camundongos, bem como a resposta aos agentes esquistossomicidas (hycanthone, oxamniquine epraziquantel não apresentaram diferenças estatisticamente significativas. Por outro lado, o número de miracídios obtidos dos intestinos e fígados dos camundongos infectados foi o dobro com a cepa LE, quando comparados com aquele do isolado SSF. Também a variação do peso dos animais foi bastante diferente. Concluiu-se que apenas uma passagem pelo hospedeiro humano não mudou substancialmente as características da cepa estudada.A laboratory technician was accidentally infected with the LE strain of Schistosoma mansoni cercariae maintained in our laboratories. After 5 months infection parasitological examination revealed 108 eggs/g faeces. Althrough treated with oxamniquine, the infection still persisted (6 eggs/g of faeces. An isolate (SSF was obtained from that person and maintained in Biomphalaria glabrata - Swiss mouse by alternate passage. The experimental comparative results between the newly obtained SSF isolate and the original LE strain showed that the differences in pre-patent period, the mice infectivity level and the schistosomicidal response to hycanthone, oxamniquine and praziquantel was not statistically significant. On the other hand the number of miracidia recovered from intestines and livers of equally infected mice was twice as miich in the LE strain than

  8. Chromatographic analysis and antiproliferative potential of aqueous extracts of Punica granatum fruit peels using the Allium cepa test

    OpenAIRE

    Andrielle Wouters Kuhn; Marília Tedesco; Aline Augusti Boligon; Margareth Linde Athayde; Haywood Dail Laughinghouse IV; Solange Bosio Tedesco

    2015-01-01

    Punica granatum L., locally known as romanzeira, is native to Asia but found throughout Brazil. P. granatum is used for treating inflammatory, infectious and respiratory diseases. The aim of this study was to evaluate the chromatography and genotoxicity of an aqueous extract of P. granatum (pomegranate) fruit peel using the Allium cepa L. test. The experiment set-up entailed 7 treatments: T1-distilled water, T2-tea 5 g.L-1, T3-tea 10 g.L-1, T4-glyphosate at 9.6%, T5-glyphosate with subsequent...

  9. Expresión de toxinas activas para larvas de mosquito por una cepa nativa de Asticaccaulis excentricus

    Directory of Open Access Journals (Sweden)

    Sergio Ordúz

    2000-02-01

    Full Text Available

    El control de mosquitos con insecticidas biológicos, como las toxinas producidas por especies del género Bacillus ha sido usado ampliamente en muchos países. Sin embargo, la rápida sedimentación de éstas las coloca fuera del alcance de la zona de alimentación de las larvas de mosquito. Con el propósito de resolver este problema se ha propuesto clonar los genes de dichas toxinas en bacterias acuáticas que son capaces de vivir y multiplicarse en la parte superior de la columna de agua, donde se alimentas los mosquitos anofelinos. Se escogieron dos cepas de la bacteria acuática Asticaccaulis excentricus para expresar los genes de la toxina binaria de B. sphaericus y el gen cry11Bb de B. thuringiensis subesp. Medellín clonados en un vector de expresión adecuado. En experimentos de alimentación se encontró que larvas de las especies Culex quinquefasciatus, Aedes aegypti y Anopheles albimanus fueron capaces de sobrevivir en una dieta basada exclusivamente en esta bacteria gram negativa. Las células de A. excentricus recombinante fueron capaces de expresar ambos genes, pero solamente la cepa expresando los genes de la toxina binaria de B. sphaericus fue tóxica para larvas de mosquito. Extractos de proteasas de A. excentricus no degradaron la toxina Cry11Bb, lo que indica que es otro el mecanismo que interfiere con la expresión de la toxicidad de la toxina Cry11Bb en esta bacteria recombinante. Los experimentos de flotación mostraron que A. excentricus recombiante se mantiene en la parte superior de la columna de agua al igual que las cepas nativas, y por más tiempo que las cepas de Bacillus.

  10. Correlation between heavy metal ions (copper, zinc, lead concentrations and root length of Allium cepa L. in polluted river water

    Directory of Open Access Journals (Sweden)

    Soraya Moreno Palacio

    2005-06-01

    Full Text Available The present work was performed using the common onion (Allium cepa L. as a bioindicator of toxicity of heavy metals in river water. The test waters were collected at two sampling sites: at the beginning and the end of the Toledo River. The bulbs of A. cepa L. were grown in test water with nine concentration levels of copper, zinc and lead from 0.1 to 50 ppm. In the laboratory, the influence of these test liquids on the root growth was examined during five days. For test liquids containing below 0.03-ppm dissolved Cu the root growth was reduced by 40% However, the same reduction occurred for 1-ppm dissolved Zn. For dissolved Pb, results reveal toxicity above 0.1 and 0.6 ppm at the beginning and the end of the Toledo river water, respectively.O presente trabalho foi realizado utilizando a cebola comum (Allium cepa L. como bioindicador da toxicidade de metais pesados em água de rio. As águas de teste foram coletadas em dois locais: na nascente e na foz do rio Toledo. Os bulbos de A. cepa L. foram cultivados em água de teste com nove níveis de concentração de cobre, zinco e chumbo de 0,1 a 50 ppm. Em laboratório a influência destes líquidos de teste em crescimento de raiz foi examinada durante cinco dias. Em todos os líquidos de teste o metal dissolvido contido foi medido pela técnica TXRF. Para líquidos de teste contendo 0,1-ppm de Cu dissolvido o crescimento da raiz foi reduzido em 50%. Entretanto, ocorreu a mesma redução para 1-ppm de Zn dissolvido. Para Pb dissolvido, o método do Allium teste revela toxidade acima de 0,1 e 0,5 ppm para a nascente e a foz do rio Toledo, respectivamente.

  11. Serotipificación y susceptibilidad antibacteriana de cepas de Pseudomonas aeruginosa aisladas de pacientes quemados infectados

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    Aniel Moya

    2003-06-01

    Full Text Available Se aislaron 11 cepas de Pseudomonas aeruginosa en 10 pacientes quemados que se encontraban hospitalizados y se les realizó tipificación serológica y antibiotipia para determinar los serotipos más frecuentes en este tipo de pacientes. Los serotipos de mayor frecuencia de aislamiento fueron el O4 y el O5. Observamos una marcada resistencia frente a los antibióticos: carbenicilina (81,8% y la azlocilina (72,7%.

  12. Toxicidad biológica de cepas nativas de Bacillus thuringiensis Berliner en larvas de Tecia solanivora Povolny

    OpenAIRE

    Paola Martínez; Wilson Martínez

    2011-01-01

    La biodiversidad microbiológica de los suelos del departamento de Boyacá aún no ha sido explorada en toda su magnitud y existen microorganismos, como en el caso de Bacillus thuringiensis Berliner (Bt), que pueden emplearse para el desarrollo de estrategias biológicas de control de plagas en el futuro. Por lo anterior, el presente trabajo evaluó la actividad biológica, expresada como  toxicidad, de cepas nativas de B. thuringiensis en la Polilla Guatemalteca  de  la  papa  Tecia  solanivora Po...

  13. Actividad antioxidante e inhibidora de a-glucosidasa y a-amilasa de tres variedades de cebolla (Allium cepa L.)

    OpenAIRE

    Leticia X. López-Martínez; Luisa M. Aguilar Cisneros; Octavio Dublán-García

    2014-01-01

    La cebolla (Allium cepa L.) ha sido cultivada durante miles de años y es utilizada como un componente importante en la dieta del ser humano. Estudios recientes sugieren que su consumo puede reducir o prevenir problemas de salud como asma, enfermedades cardiovasculares y diabetes, debido a sus efectos antioxidantes. En este estudio se determinó el contenido de compuestos fenólicos totales, la capacidad antiradical y la inhibición de las enzimas α-glucosidasa y α-amilasa de extractos acuosos y ...

  14. Certain antioxidant enzymes of Allium cepa as biomarkers for the detection of toxic heavy metals in wastewater

    International Nuclear Information System (INIS)

    The utility of antioxidant enzymes, viz glutathione-S-transferase (GST), glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), glutathione peroxidase (GPX), monodehydroascorbate reductase (MDHAR) and dehydroascorbate reductase (DHAR), as biomarkers of heavy metal pollution in water was investigated using the Allium cepa (onion) system. These antioxidant enzymes were assayed in onion bulbs exposed to certain heavy metals taken separately, the test metals taken in combination as well as the industrial wastewater especially found to contain these metals. GST exhibited significantly enhanced activity upon treatment with individual heavy metals. However, GR, SOD and CAT did not show such a pronounced increase in activities. At higher heavy metal concentrations, GR, SOD and CAT showed a steep decline while GST activity still showed a rise. Moreover, APX, GPX and MDHAR also exhibited remarkable induction with increase in the concentration of individual heavy metals. However, there was no significant change in DHAR activity with respect to the controls. Metabolites like ascorbate (ASC) and glutathione (GSH) exhibited significant decline with increase in the concentration of individual heavy metals while the level of H2O2 continued to display the rise up to a heavy metal concentration of 100 μM, after which it showed a gradual decline. A. cepa bulbs treated with wastewater sample showed enzyme activity profiles similar to that shown with heavy metals, thereby suggesting the presence of heavy metals in the test wastewater. Atomic absorption spectrophotometry also detected large amounts of Cd, Cr, Cu, Hg, Pb and Zn in the test water sample. The metal mixture, containing the amounts of heavy metals equivalent to those found in the wastewater, resulted in steep declines in GR, SOD and CAT activities in A. cepa while GST showed a rise. However, when this metal mixture was diluted to 2000-fold, GR, SOD and CAT also showed enhanced

  15. Investigation of Proline, Chlorophyll and Carotenoids Changes Under Drought Stress in Some Onion (Allium Cepa L.) Cultivars

    OpenAIRE

    HANCI, Fatih; CEBECİ, Esra

    2014-01-01

    Drought is one of the major limitations for vegetable growth and productivity all over the World. In this study the effects of drought stress on proline, chlorophyll a/b, total chlorophyll and carotenoids were investigated in some onion (Allium cepa L.) cultivars (Kantartopu-3, Akgun-12 and Texas Early Grano) under the early plant growth phase. Seeds were germinated in peat material and transferred to plastic pots after 21 days of sowing. The plants have been grown in vermiculite by “substrat...

  16. Estudio del comportamiento de diferentes cepas de Staphylococcus aureus frente a los cementos de obturación de conductos radiculares

    OpenAIRE

    Pumarola Suñé, José; Berástegui, Esther; Canalda Sahli, Carlos; Brau Aguadé, Esteban

    1991-01-01

    El objetivo de este trabajo es estudiar el comportamiento de 120 cepas de Staphylococcus aureus frente a siete cementos selladores: Traitement Spad, Endométhasonc, N2 Universal, AH26 con plata, Diaket-A, Tubli Sea! y Sealapex. La prueba de susceptibilidad microbiana empleada ha sido el test de difusión en agar utilizando como medio de cultivo el agar de Muelle r-Tlinton. Los resultados obtenidos demuestran un comportamiento significativamente diferente de las diversas cepas probadas. En conse...

  17. Evaluación preliminar de la micorriza versículo-arbuscular en dos sistemas: pastizal y cebolla de bulbo Allium cepa

    OpenAIRE

    Muñoz F. Jaime Eduardo; Sánchez de Prager Marina; Bastidas Vanessa

    1993-01-01

    Se evaluó durante dos semestres la micorriza en dos sistemas: pastizal y cultivo de Allium cepa, en un mismo sitio con un contenido de P alto. Para el pastizal se tomaron muestras en cinco lotes identificando las especies presentes y su abundancia relativa, en A. cepa se tomaron muestras en cinco edades del cultivo. En ambos sistemas se evaluó porcentaje de infección por MVA (PI), número de esporas por 50 g de suelo (NES), se identificaron las especies de MVA y se obtuvo su frecuencia. En el ...

  18. Antioxidants in aqueous extract of Myristica fragrans (Houtt.) suppress mitosis and cyclophosphamide-induced chromosomal aberrations in Allium cepa L. cells

    OpenAIRE

    Akinboro, Akeem; Mohamed, Kamaruzaman Bin; Asmawi, Mohd Zaini; Sulaiman, Shaida Fariza; Sofiman, Othman Ahmad

    2011-01-01

    In this study, freeze-dried water extract from the leaves of Myristica fragrans (Houtt.) was tested for mutagenic and antimutagenic potentials using the Allium cepa assay. Freeze-dried water extract alone and its combination with cyclophosphamide (CP) (50 mg/kg) were separately dissolved in tap water at 500, 1000, 2000, and 4000 mg/kg. Onions (A. cepa) were suspended in the solutions and controls for 48 h in the dark. Root tips were prepared for microscopic evaluation. 2,2-Diphenyl-1-picrylhy...

  19. Detección inmunoquímica de esterasas en dos cepas de la garrapata boophilus microplus (acarii: ixodidae) resistentes a ixodicidas

    OpenAIRE

    Rodrigo Rosario Cruz; Zeferino García Vázquez; John George Edward

    2000-01-01

    Se encontró una esterasa en Boophilus microplus con actividad incrementada, en dos cepas de garrapatas resistentes a acaricidas de la familia de los piretroides y organofosforados, que fue detectada después de ser separadas electroforéticamente. La proteína fue separada y utilizada en la preparación de un anticuerpo policlonal monoespecífico. La especificidad de este anticuerpo fue probada mediante un ensayo de inmunoelectrotransferencia, en extractos totales de dos cepas de garrapatas resist...

  20. Avances en la sistemática del género Micromonospora: estudio de cepas aisladas de la Rizosfera y Nódulos de Pisum sativum

    OpenAIRE

    Carro Garcia, Lorena

    2010-01-01

    [ES] En este trabajo se ha llevado a cabo el aislamiento de 272 cepas, 239 obtenidas a partir de nódulos fijadores de nitrógeno de plantas de Pisum sativum esterilizados en superficie y recogidos en siete localidades diferentes de Castilla y León y 33 a partir de la rizosfera de esas mismas plantas. De estas cepas se seleccionaron las 106 obtenidas en Cañizal y en Salamanca, 27 y 46 obtenidas de nódulos, y 21 y 12 obtenidas de rizosfera respectivamente, para realizar un análisis de la diversi...

  1. Prueba de inmunodifusión radial con hapteno nativo para diferenciar bovinos con revacunaciones repetidas con la cepa S19 de Brucella abortus

    OpenAIRE

    Esperanza González Miranda; Laura Hernández Andrade; Efrén Díaz Aparicio

    2006-01-01

    El objetivo del estudio fue establecer la capacidad de la inmunodifusión radial (IDR) con hapteno nativo, para diferenciar anticuerpos post-vacunales de anticuerpos por infección, en bovinos con revacunaciones repetidas de cepa S19. Se trabajó en un establo del estado de México, con presencia de abortos, retención de placenta, expulsiones y fetos momificados. Las becerras se vacunaban con dosis clásica de cepa S19 de B. abortus, y ya adultas revacunaciones anuales repetidas con dosis reducida...

  2. The potential for controlling Pangaeus bilineatus (Heteroptera: Cydnidae) using a combination of entomopathogens and an insecticide.

    Science.gov (United States)

    Mbata, George N; Shapiro-Ilan, David

    2013-10-01

    The peanut burrower bug, Pangaeus bilineatus (Say), is an important pest of peanut (Arachis hypogaea L.) in the southern United States. Current control methods for this pest, which are based on the use of chemical insecticides, have not been successful. Our objective was to determine if entomopathogens applied alone or in combination with a standard chemical insecticide would provide superior levels of P. bilineatus mortality compared with the standard chemical applied alone. Specifically, we investigated the efficacy of an entomopathogenic nematode, Heterorhabditis bacteriophora Poinar (Oswego strain), and a fungus, Beauveria bassiana (Balsamo) Vuillemin (GHA strain), applied alone or in combination with chlorpyrifos. When applied as single treatments, the two entomopathogens were not pathogenic, that is, they did not cause mortality in P. bilineatus adults that was different from the nontreated control. However, 3 and 7 d posttreatment, the combination of the H. bacteriophora and chlorpyrifos caused higher mortality than the nematode, fungus, or insecticide alone, or the combination of chlorpyrifos and B. bassiana. The nature of the interaction between H. bacteriophora and chlorpyrifos was synergistic, which is of particular interest, given that this is the first time a synergy is being reported between a nematode that was not pathogenic when applied alone and a chemical insecticide. B. bassiana and its combination with the chlorpyrifos did not significantly increase insect mortality compared with chlorpyrifos alone or the control. Based on the observation of synergy, the combination of H. bacteriophora and chlorpyrifos should be investigated further for potential adoption in the management of P. bilineatus.

  3. Investigation of protective effects of Erythrina velutina extract against MMS induced damages in the root meristem cells of Allium cepa

    Directory of Open Access Journals (Sweden)

    Deborah S. B. S. Silva

    2013-04-01

    Full Text Available Erythrina velutina Willd., Fabaceae, is a medicinal plant that can be found in the tropics and subtropics, including in the semi-arid northeastern Brazil. It is commonly used in folk medicine to treat anxiety, agitation and insomnia. E. velutina has been known to present analgesic, anti-inflammatory and antibacterial activities, however, it is unknown if this plant present a protective effect on DNA. We assessed the antigenotoxic effect of E. velutina against the genotoxic effects induced by MMS in the root meristem cells of Allium cepa. Three concentrations of the aqueous extract (100, 200 and 400 mg/L of this medicinal plant were used in three different types of treatment (pre-, post- and simultaneous. The effects of the extracts on the root meristem cells of A. cepa were analyzed at both macroscopic and microscopic levels. Protective effects were observed at higher concentrations in pre-treatment and in simultaneous treatment. The results suggest that E. velutina may present antigenotoxic properties and demonstrate its chemopreventive potential.

  4. Water Quality of Urban Streams: The Allium cepa Seeds/Seedlings Test as a Tool for Surface Water Monitoring

    Directory of Open Access Journals (Sweden)

    Camila Gonçalves Athanásio

    2014-01-01

    Full Text Available The present study investigates the genotoxic, mutagenic, and cytotoxic potential of surface waters in urban streams using Allium cepa and analyzes the applicability of this assay for environmental monitoring. Water samples were collected from three streams located in the urban area of a municipality in the south of Brazil. For each stream, two samples were collected, one upstream and one downstream of the pollution discharge site. Physicochemical evaluation indicated that all samples had various degrees of environmental impact, but substantial impact was seen for the downstream samples of the Preto and Pedras streams. All samples increased the frequency of chromosome aberrations (P<0.05. The sample from Pedras downstream site also caused a decrease in mitotic index (P<0.08 and increase in micronuclei (P<0.08 frequency, indicating potential cytotoxicity and mutagenicity. The Pedras stream receives mixed industrial and urban wastewater, while the Lajeado and Preto streams receive wastewater predominantly domestic in nature, which may partially explain the difference in toxicity among the samples. Moreover, the Allium cepa seeds/seedlings were shown to be extremely sensitive in detecting the genotoxicity of environmental water samples and can be applied as the first tool for environmental health hazard identification and prediction.

  5. Variabilidad genética en cepas de Plasmodium falciparum circulantes en regiones colombianas con riesgo diferente para malaria

    Directory of Open Access Journals (Sweden)

    Mauricio Arcos Burgos

    2000-02-01

    Full Text Available

    La presencia de malaria en una zona es el resultado de una interacción dinámica entre los hospederos humanos, los plasmodios, el vector y el medio ambiente ecológico, físico, socioeconómico y cultural. Plasmodium falciparum, es la especie que produce la enfermedad más grave. La diversidad genética de las cepas de P. falciparum se expresa en el gran polimorfismo antigénico, en la susceptibilidad de este plasmodio a las diferentes drogas utilizadas para su tratamiento y en la patogenicidad de las cepas. El secuenciamiento de genes de P. falciparum ha demostrado diferencias tanto en tamaño como en la secuencia de regiones repetitivas que codifican para la parte inmunodominante de antígenos altamente polimórficos.

    Algunos estudios asocian el grado de variabilidad genética con la endemicidad de malaria en la zona. Estos hallazgos han permitido formular la hipótesis de que a mayor endemicidad mayor variabilidad genética del P. falciparum (2, 3, sin embargo la mayoría de estudios se han realizado en zonas altamente endémicas y poco se conoce sobre la complejidad genética de P. falciparum en zonas de baja y moderada endemicidad. La variabilidad genética de cepas de P. falciparum circulantes en Colombia según el riesgo por regiones es desconocido, en Colombia, según el Índice Parasitario Anual (IPA, hay zonas de alto riesgo (IPA >10, mediano riesgo (IPA entre 2-10 y de bajo riesgo (IPA entre 0-2 para malaria, pensamos que a mayor endemicidad de la malaria en una zona mayor será la variabilidad genética de las cepas de P. falciparum circulantes en ella, por eso queremos conocer el grado de variabilidad genética de las cepas de P. falciparum circulantes en zonas colombianas con diferente riesgo para malaria y la presencia de infección multiclonal en dichas áreas. Para determinar el

  6. Ability of Allium cepa L. root tips and Tradescantia pallida var. purpurea in N-nitrosodiethylamine genotoxicity and mutagenicity evaluation

    Directory of Open Access Journals (Sweden)

    Claudia R. de Rainho

    2010-12-01

    Full Text Available N-nitroso compounds, such as N-nitrosodiethylamine (NDEA, can be formed by the reaction of secundary amines with nitrosating agents, and are suspected to be involved in tumors in humans. NDEA has been considered a weak carcinogen in genotoxic assays probably due to the inefficient nitrosamine activation system that is used and/or to the efficient repair system. In this work, we evaluated the sensibility of Allium cepa L. root tips and Tradescantia stamen hair mutation assay (Trad-SH using Tradescantia pallida var. purpurea for NDEA (0.1; 0.5; 5 and 25mM genotoxicity and mutagenicity induction. Allium cepa L. was treated with different NDEA concentrations for 3h, for 3 consecutive days, including negative control (distilled water and positive control maleic hydrazide (MH 30mg/mL. After treatment, the roots were hydrolyzed, squashed, and the mitotic index (MI and cytological abnormalities were scored. The results revealed a cytostatic effect of NDEA (0.5 and 5mM, showing a significant reduction in the MI. Chromosome stickiness suggests a NDEA toxic effect. T. pallida purpurea did not respond to mutagens with a dose-dependent pattern. In conclusion, our study indicates that the root tips of Allium cepa L. have sensibility to detect NDEA genotoxicity, but not for Trad-SH test.Nitrocompostos, como N-nitrosodietilamina (NDEA, podem ser formados pela reação entre uma amina secundária e agentes nitrosantes e são suspeitos de estarem envolvidos na formação de tumores em humanos. NDEA é considerada um carcinógeno fraco e ensaios genotóxicos provavelente pela utilização de um sistema de ativação ineficiente e/ou pela utilização de um eficiente sistema de reparo. Neste trabalho, nós avaliamos a sensibilidade de ensaios com Alliu cepa L. e Tradescantia pallida var. purpurea (Trad-SH à genotoxicidade e mutagenicidade induzidas por diferentes concentrações de NDEA (0,1; 0,5; 5 e 25mM por 3h, por 3 dias consecutivos, incluindo controle

  7. Molecular characterization of transgenic shallots (Allium cepa L.) by adaptor ligation PCR (AL-PCR) and sequencing of genomic DNA flanking T-DNA borders

    NARCIS (Netherlands)

    Zheng, S.J.; Henken, G.; Sofiari, E.; Jacobsen, E.; Krens, F.A.

    2001-01-01

    Genomic DNA blot hybridization is traditionally used to demonstrate that, via genetic transformation, foreign genes are integrated into host genomes. However, in large genome species, such as Allium cepa L., the use of genomic DNA blot hybridization is pushed towards its limits, because a considerab

  8. Patrones de adherencia de cepas de Escherichia coli Difusamente adherente (DAEC) provenientes de niños con y sin diarrea Adhesion patterns in diffusely adherent Escherichia coli (DAEC) strains isolated from children With and without diarrhea

    OpenAIRE

    Maribel Riveros; Francesca Barletta; Martín Cabello; David Durand; Erik H. Mercado; Carmen Contreras; Fulton P. Rivera; Susan Mosquito; Ángela Lluque; Theresa J. Ochoa

    2011-01-01

    Introducción. Las E. coli de adherencia difusa (DAEC) son el sexto grupo de E. coli diarrogénicas reconocidas. Su asociación con diarrea es controversial. No se conoce la variabilidad en los patrones de adherencia de cepas clínicas. Objetivos. Comparar los patrones de adherencia entre cepas aisladas de niños con y sin diarrea. Materiales y métodos. Se analizó 31 cepas DAEC, 25 de diarrea y 6 de niños asintomáticos (control) aislados de un estudio de cohorte de niños menores de 12 meses en el ...

  9. Imunogenicidade da cepa avirulenta RV194-2 do vírus rábico em camundongos

    Directory of Open Access Journals (Sweden)

    Rugimar Marcovistz

    1996-12-01

    Full Text Available O vírus rábico RV194-2, uma variante avirulenta da cepa CVS (Challenge Vírus Standard, produz uma infecção inaparente quando inoculado intracerebralmente em camundongos adultos. Sugerindo que a resposta imunológica do hospedeiro permite a eliminação do vírus do sistema nervoso central. Por esta razão foram estudadas a indução de interferon e a resposta imune humoral em camundongos BALB/c inoculados com vírus RV194-2. Durante a infecção, estes camundongos apresentaram elevados níveis de interferon no plasma e no cérebro com altos títulos de anticorpos neutralizantes anti-rábicos. A 2-5A sintetase. um marcador da ação dos interferons,foi também analisada no cérebro destes animais. Sua atividade, aumentou, paralelamente, á produção de interferon, demonstrando que este interferon é bioquímicamente ativo. O vírus RV194-2 também induziu, 45 dias após sua inoculação, proteção aos animais quando desafiados com a cepa virulenta CVS. Estes resultados demonstram que a cepa RV194-2possui um alto nível imunogênico.RV194-2 rabies virus, an avirulent mutant of CVS strain, induces an inapparent infection limited to the central nervous system (CNS in adult mice inoculated intracerebrally. This fact suggest that immune response of the host is able to eliminate the virus in CNS. For this reason, we have studied the induction of interferon and the humoral immune responses in BALB/c mice after RV194-2 inoculation. These mice presented high levels of interferon in the plasma and in the brain, with elevated levels of neutralizing antirabies antibodies. The 2-5A synthetase, an enzyme marker of interferon action, was analyzed in the brain of inoculated animals. Its enhancement in parallel to the interferon production in the brain, showed biochemical evidence that this interferon is active. Forty five days after RV194-2 virus inoculation, mice were protected against a challenge with the CVS virulent strain. The results presented

  10. Laboratory Evaluation of Seven Pakistani Strains of Entomopathogenic Nematodes Against a Stored Grain Insect Pest, Pulse beetle Callosobruchus chinensis (L.)

    Science.gov (United States)

    Javed, Salma

    2009-01-01

    Seven Pakistani strains of entomopathogenic nematodes belonging to the genera Steinernema and Heterorhabditis were tested against last instar and adult stages of the pulse beetle, Callosobruchus chinensis (L.). These nematodes included Steinernema pakistanense Shahina, Anis, Reid and Maqbool (Ham 10 strain); S. asiaticum Anis, Shahina, Reid and Rowe (211 strain); S. abbasi Elawad, Ahmad and Reid (507 strain); S. siamkayai Stock, Somsook and Reid (157 strain); S. feltiae Filipjev (A05 strains); Heterorhabditis bacteriophora Poinar (1743 strain); and H. indica Poinar, Karunakar and David (HAM-64 strain). Activity of all strains was determined at four different nematode densities in Petri dishes and in concrete containers. A significant nematode density effect was detected for all nematode species tested. Overall, Heterorhabditis bacteriophora, S. siamkayai, and S. pakistanense were among those that showed the highest virulence to pulse beetle larvae and adults. For all nematode species, the last larval stage of the pulse beetle seems to be more susceptible than the adult. LC50 values in Petri dish and concrete containers were 14-340 IJs/larvae and 41-441 IJs/larvae, respectively, and 59-1376 IJs/adult and 170-684/adult, respectively. PMID:22736823

  11. Effect of 5-Aminouracil on mitotic cell division in Allium cepa Efeito de 5-Aminouracil na divisão mitótica de células de Allium cepa

    OpenAIRE

    Veronica Elisa Pimenta Vicentini; Marcia Flores da Silva; Maria de Fátima Pires da Silva Machado

    1999-01-01

    A exposição de células meristemáticas de Allium cepa por dois ciclos de divisões (48 horas), em soluções contendo concentrações mais baixas de 5-aminouracil (50, 100 e 150μM) do que as usualmente empregadas para proceder à sincronização da proliferação celular, mostrou que as concentrações usadas causam anormalidades cromossômicas e formação de micronúcleos, mas não bloqueiam a entrada destas células em mitose. As células em mitose e com micronúcleos podem prosseguir em divisão e assim con...

  12. Atividade antibacteriana de óleos essenciais em cepas isoladas de infecção urinária

    Directory of Open Access Journals (Sweden)

    Pereira Rogério Santos

    2004-01-01

    Full Text Available A análise da atividade antibacteriana de óleos essenciais de ervas medicinais (Ocimum gratissimum, L., Cybopogum citratus (DC Stapf. e Salvia officinalis, L. foi verificada frente a 100 cepas de bactérias isoladas de indivíduos da comunidade com diagnóstico de infecção urinária. Os microrganismos foram semeados em ágar Muller Hinton e os extratos aplicados com replicador de Steers e incubados a 37degreesC por 24 horas. Verificou-se que Salvia officinalis, L. apresentou ação inibitória superior às outras ervas, tendo eficácia de 100% quando testadas em espécies de Klebsiella e Enterobacter, 96% em Escherichia coli, 83% contra Proteus mirabilis e 75% contra Morganella morganii.

  13. Lesões cardíacas em ratos wistar inoculados com diferentes cepas do Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    E. Chapadeiro

    1988-09-01

    Full Text Available Ratos albinos Wistar infectados com diferentes inóculos das cepas Y, Colombiana (COL e São Felipe (12SF do Trypanosoma cruzi desenvolveram parasitemia elevada entre 14e21 dias, a qual tomou-se desprezível ou desapareceu completamente ao final da 4ª semana. As lesões do coração foram avaliadas, semiquantitativamente, pelo sistema de "scores", conforme a intensidade e a extensão da inflamação, nas diferentes estruturas do órgão, tendo sido observado que: a na fase inicial (aguda da infecção, os animais mortos espontaneamente ou em conseqüência de acidente anestésico apresentaram cardite de intensidade moderada à acentuada, não havendo diferença em relação às cepas utilizadas; as diferentes estruturas do coração estavam uniformemente comprometidas; b na fase crônica da infecção observou-se cardite degrau leve a moderado e as lesões foram mais freqüentes e intensas quanto maior o inoculo empregado; no entanto, inóculos baixos só produziram lesões quando a cepa utilizada foi a Colombiana. Trombose mural nos átrios e dilatação da ponta do ventrículo esquerdo foram observadas em 20% dos animais, independentemente da cepa. Na fase crônica 15% dos animais apresentaram miocardite crônica com fibrose, associada à hipertrofia das miocélulas. Os AA confirmam ser o rato albino suscetível à infecção chagásica e, portanto, um modelo útil no estudo das manifestações cardíacas da Doença de Chagas.Wistar albino rats infected intraperitonially with different inocula of Y, 12SF and Colombian strains of Trypanosoma cruzi developed high parasitemia, which lowered by the end of the 6th week; mortality varied according with the strain and inoculum. Acute carditis like that occurring in the human, was found in all animals killed or dying spontaneously. The surviving rats were sacrificed in the 8th month of infection. They presented active chronic carditis involving especially the myocardium and the intracardiac nervous

  14. Encuestas sobre tasas de portadores sanos de N. Meningitidis y caracterización de cepas circulantes

    Directory of Open Access Journals (Sweden)

    Julián Mauro Ramos Aceitero

    2000-01-01

    Full Text Available FUNDAMENTO: Durante la temporada epidémica 1.996-97 el incremento de incidencia de Enfermedad Meningocócica por N. Meningitidis serogrupo C llevó a instaurar programas de vacunación y realizar distintos estudios, entre ellos dos para conocer la prevalencia de portadores sanos que presentamos. MÉTODO: Portadores sanos en población general: encuesta transversal realizada entre marzo y mayo de 1.998, entre residentes en Extremadura. Tomamos dos grupos de edad: 0-19 años, vacunados (n=1.140 y 20 y más años (n=1.193, no vacunados. Portadores sanos en un acuartelamiento: encuesta transversal en una base militar durante mayo de 1.998 (n=619, tomando dos grupos: < 20 años (n=453 vacunados, y 20 y más años (n=166 no vacunados RESULTADOS: Portadores sanos en población general El porcentaje de portadores para todos los serogrupos fue: grupo de 0-19 años 7’98, grupo 20 y más años 3’32, total 4’60, para serogrupo B: 4’43, 2’25 y 2’84; para C: 0’04, 0’10 y 0’08 respectivamente. Las diferencias entre ambos grupos de edad del serogrupo B y total son estadísticamente significativas, así como la mayor prevalencia del B sobre C. El subtipo de las tres muestras con aislamiento de serogrupo C fue: una cepa NT:P1.6, una 2b:P1.2, y una no pudo sub-tiparse. Una cepa no serogrupable se subtipo como 2b: P1. 5. Portadores sanos en un acuartelamiento El porcentaje de portadores para todos los serogrupos fue: < 20 años 8’43, 20 y más años 6’84, total 7’27, para serogrupo B: 4’82, 3’75 y 4’04; y para C: 0’60, 0’00 y 0’16 respectivamente. Las mayores prevalencias obtenidas en militares sobre población general mostraron diferencias estadísticamente significativas. También la prevalencia de serogrupo B es significativamente muy superior a la C. La única cepa de C aislada se subtipó 2b : p1.2,5. CONCLUSIONES: La prevalencia de portadores sanos de N. meningitidis en población general es de 4,60 %, siendo mayor en el grupo de menor edad

  15. Encuestas sobre tasas de portadores sanos de N. Meningitidis y caracterización de cepas circulantes

    Directory of Open Access Journals (Sweden)

    Ramos Aceitero Julián Mauro

    2000-01-01

    Full Text Available FUNDAMENTO: Durante la temporada epidémica 1.996-97 el incremento de incidencia de Enfermedad Meningocócica por N. Meningitidis serogrupo C llevó a instaurar programas de vacunación y realizar distintos estudios, entre ellos dos para conocer la prevalencia de portadores sanos que presentamos. MÉTODO: Portadores sanos en población general: encuesta transversal realizada entre marzo y mayo de 1.998, entre residentes en Extremadura. Tomamos dos grupos de edad: 0-19 años, vacunados (n=1.140 y 20 y más años (n=1.193, no vacunados. Portadores sanos en un acuartelamiento: encuesta transversal en una base militar durante mayo de 1.998 (n=619, tomando dos grupos: < 20 años (n=453 vacunados, y 20 y más años (n=166 no vacunados RESULTADOS: Portadores sanos en población general El porcentaje de portadores para todos los serogrupos fue: grupo de 0-19 años 7'98, grupo 20 y más años 3'32, total 4'60, para serogrupo B: 4'43, 2'25 y 2'84; para C: 0'04, 0'10 y 0'08 respectivamente. Las diferencias entre ambos grupos de edad del serogrupo B y total son estadísticamente significativas, así como la mayor prevalencia del B sobre C. El subtipo de las tres muestras con aislamiento de serogrupo C fue: una cepa NT:P1.6, una 2b:P1.2, y una no pudo sub-tiparse. Una cepa no serogrupable se subtipo como 2b: P1. 5. Portadores sanos en un acuartelamiento El porcentaje de portadores para todos los serogrupos fue: < 20 años 8'43, 20 y más años 6'84, total 7'27, para serogrupo B: 4'82, 3'75 y 4'04; y para C: 0'60, 0'00 y 0'16 respectivamente. Las mayores prevalencias obtenidas en militares sobre población general mostraron diferencias estadísticamente significativas. También la prevalencia de serogrupo B es significativamente muy superior a la C. La única cepa de C aislada se subtipó 2b : p1.2,5. CONCLUSIONES: La prevalencia de portadores sanos de N. meningitidis en población general es de 4,60 %, siendo mayor en el grupo de menor edad y el

  16. De Novo Assembly and Transcriptome Analysis of Bulb Onion (Allium cepa L.) during Cold Acclimation Using Contrasting Genotypes.

    Science.gov (United States)

    Han, Jeongsukhyeon; Thamilarasan, Senthil Kumar; Natarajan, Sathishkumar; Park, Jong-In; Chung, Mi-Young; Nou, Ill-Sup

    2016-01-01

    Bulb onion (Allium cepa) is the second most widely cultivated and consumed vegetable crop in the world. During winter, cold injury can limit the production of bulb onion. Genomic resources available for bulb onion are still very limited. To date, no studies on heritably durable cold and freezing tolerance have been carried out in bulb onion genotypes. We applied high-throughput sequencing technology to cold (2°C), freezing (-5 and -15°C), and control (25°C)-treated samples of cold tolerant (CT) and cold susceptible (CS) genotypes of A. cepa lines. A total of 452 million paired-end reads were de novo assembled into 54,047 genes with an average length of 1,331 bp. Based on similarity searches, these genes were aligned with entries in the public non-redundant (nr) database, as well as KEGG and COG database. Differentially expressed genes (DEGs) were identified using log10 values with the FPKM method. Among 5,167DEGs, 491 genes were differentially expressed at freezing temperature compared to the control temperature in both CT and CS libraries. The DEG results were validated with qRT-PCR. We performed GO and KEGG pathway enrichment analyses of all DEGs and iPath interactive analysis found 31 pathways including those related to metabolism of carbohydrate, nucleotide, energy, cofactors and vitamins, other amino acids and xenobiotics biodegradation. Furthermore, a large number of molecular markers were identified from the assembled genes, including simple sequence repeats (SSRs) 4,437 and SNP substitutions of transition and transversion types of CT and CS. Our study is the first to provide a transcriptome sequence resource for Allium spp. with regard to cold and freezing stress. We identified a large set of genes and determined their DEG profiles under cold and freezing conditions using two different genotypes. These data represent a valuable resource for genetic and genomic studies of Allium spp. PMID:27627679

  17. Microscopic examination on cytological changes in Allium cepa and shift in phytoplankton population at different doses of Atrazine

    Science.gov (United States)

    Ghosh, Nabarun; Finger, Kristen; Usnick, Samantha; Rogers, William J.; Das, A. B.; Smith, Don W.

    2010-06-01

    Atrazine is a wide-range herbicide. For over 50 years, atrazine has been used as a selective broadleaf herbicide in many capacities, from pre-plant to pre-emergence to post-emergence, depending on the crop and application. Currently, 96% of all atrazine used is for commercial applications in fields for the control of broadleaf and grassy weeds in crops such as sorghum, corn, sugarcane, pineapple and for the control of undesirable weeds in rangeland. Many panhandle wells have also detected atrazine in samples taken. The concern for the public is the long-term effect of atrazine with its increasing popularity, and the impact on public health. We investigated the effect of different concentrations of atrazine on Allium cepa (onion), a standard plant test system. We established a control with the Allium bulbs grown on hydroponics culture. Varying concentrations of atrazine was used on the standard plant test system, Allium cepa grown hydroponically. The mitotic indices varied and with higher doses, we observed various chromosomal abnormalities including sticky bridges, early and late separations, and lag chromosomes with higher doses of treatments. In the second part of the experiment, 0.1ppb, 1ppb, 10ppb, and 100ppb concentrations of atrazine were applied to established phytoplankton cultures from the Lake Tanglewood, Texas. Study with a Sedgwick-Rafter counter, a BX-40 Olympus microscope with DP-70 camera revealed a gradual shift in the phytoplankton community from obligatory to facultative autotroph and finally to a parasitic planktonic community. This explains the periodic fish kill in the lakes after applications of atrazine in crop fields.

  18. Phenotypic polomorphism in indigenous strains of sporothrix schenckii Polimorfismo fenotípico de cepas autóctonas de Sporothrix schenckii

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    Fernando Montoya Maya

    1996-02-01

    Full Text Available

    We studied macroscopic colony findings, sugar assimilation patterns and virulence of 55 Sporothrix schenckij strains obtained from patients with cutaneous sporothrichosis. They were collected during a 10-year period at the Mycology Laboratory, University of Antioquia, School of Medicine, Medellín, Colombia. Pigmentation types and macroscopic morphological characteristics’ were studied on mycosel agar and malt extract. In most cases 2 or 3 colony colors were present In both media. In mycosel agar only 5 strains (9.1% were monochromatic. Pigmentation was very stable in that medium. Eighty five percent of the mycosel agar colonies were beige, brown, pleated or pleated and umbilicated. All strains assimilated D-glucosa, glycerol and D-xylosa. We established 9 patterns of assimilation (blotypes, from A to I In 25 strains. Both pigmented and albino strains were virulent for mice. We emphasize the diversity of our Indigenous strains, and the importance of genotypic characterization and of the correlation studies of phenotypic and genotypic variation with the clinical and geographical patterns of the disease.

    Se presentan los resultados macroscópicos, de asimilación de azúcares y de virulencia de 55 cepas de Sporothrix schenckii aisladas a partir de lesiones de pacientes con esporotricosis cutánea, que consultaron al laboratorio de micología de la Facultad de Medicina de la Universidad de Antioquia en Medellín, Colombia, y que fueron coleccionadas en el transcurso de 10 años. La morfología macroscópica de las colonias y su pigmentación se evaluaron tanto en agar mycosel como en extracto de malta. La mayoría de las cepas en los dos medios presentaban colonias con 2 ó 3 colores diferentes. En mycosel 5 cepas (9.1% fueron monocromáticas y éste fue el medio más estable para definir las

  19. Efecto de lactoferrina bovina en la formación de biofilms en cepas clínicas de E. coli enteroagregativa

    Directory of Open Access Journals (Sweden)

    Cecilia Coveñas

    2014-09-01

    Full Text Available Objetivos. Determinar el efecto de lactoferrina bovina (bLf en la formación de biofilms en cepas clínicas de Escherichia coli enteroagregativa (EAEC, y si este efecto es independiente del hierro. Materiales y métodos. Se utilizaron dos métodos: (a cualitativo, mediante observación directa por microscopia óptica, y (b cuantitativo, lecturas de los valores de absorbancia mediante lector de ELISA en presencia de bLf en concentraciones de 0,01mg/mL y 1mg/mL, con y sin hierro, y no bLf (control, en 122 cepas de EAEC para el método cuantitativo (60 cepas de niños con diarrea y 62 de niños sanos y 31 cepas para el método cualitativo. Resultados. (a Método cualitativo: se evaluaron 31 cepas, con y sin hierro. Sin hierro la formación de biofilms fue de 77% (24/31 en el grupo control versus 58% (14/31 con bLf de 0,01 mg/mL y 4% (1/31 con 1 mg/mL. Con hierro la formación de biofilms fue 90% (28/31 en el grupo control versus 55% (17/31 con bLf de 0,01 mg/mL y 4% (1/31 a 1 mg/mL. (b Método cuantitativo: sin hierro la absorbancia medida a OD 560 nm del grupo control fue 0,7 ± 0,5 versus 0,4 ± 0,3 con bLf 0,01mg/mL y 0,3 ± 0,2 con bLf de 1 mg/mL (p<0,0001. Esta disminución en presencia de bLf incluso se dio con hierro. Conclusiones. La bLf tiende a disminuir la formación de biofilms, mostrando un efecto inhibitorio en las cepas clínicas de EAEC, este efecto no es hierro-dependiente

  20. Efecto de lactoferrina bovina en la formación de biofilms en cepas clínicas de E. coli enteroagregativa

    Directory of Open Access Journals (Sweden)

    Cecilia Coveñas

    2014-07-01

    Full Text Available Objetivos. Determinar el efecto de lactoferrina bovina (bLf en la formación de biofilms en cepas clínicas de Escherichia coli enteroagregativa (EAEC, y si este efecto es independiente del hierro. Materiales y métodos. Se utilizaron dos métodos: (a cualitativo, mediante observación directa por microscopia óptica, y (b cuantitativo, lecturas de los valores de absorbancia mediante lector de ELISA en presencia de bLf en concentraciones de 0,01mg/mL y 1mg/mL, con y sin hierro, y no bLf (control, en 122 cepas de EAEC para el método cuantitativo (60 cepas de niños con diarrea y 62 de niños sanos y 31 cepas para el método cualitativo. Resultados. (a Método cualitativo: se evaluaron 31 cepas, con y sin hierro. Sin hierro la formación de biofilms fue de 77% (24/31 en el grupo control versus 58% (14/31 con bLf de 0,01 mg/mL y 4% (1/31 con 1 mg/mL. Con hierro la formación de biofilms fue 90% (28/31 en el grupo control versus 55% (17/31 con bLf de 0,01 mg/mL y 4% (1/31 a 1 mg/mL. (b Método cuantitativo: sin hierro la absorbancia medida a OD 560 nm del grupo control fue 0,7 ± 0,5 versus 0,4 ± 0,3 con bLf 0,01mg/mL y 0,3 ± 0,2 con bLf de 1 mg/mL (p<0,0001. Esta disminución en presencia de bLf incluso se dio con hierro. Conclusiones. La bLf tiende a disminuir la formación de biofilms, mostrando un efecto inhibitorio en las cepas clínicas de EAEC, este efecto no es hierro-dependiente

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

    Directory of Open Access Journals (Sweden)

    Isabel Martínez

    2006-04-01

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

  2. EVALUACIÓN DE CEPAS NATIVAS DEL GÉNERO Azospirillum Y SU INTERACCIÓN CON EL CULTIVO DEL ARROZ

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    Mabel Pazos

    2001-01-01

    Full Text Available Catorce cepas nativas pertenecientes a la especie Azospirillum brasilense se caracterizaron en cuanto a su ca- pacidad de fijar el nitrógeno atmosférico. Se estudió su efecto en el cultivo del arroz (Oryza sativa, mediante el modelo Microcosmos, realizando determinaciones de la altura de las plantas inoculadas, masa fresca de la raíz y el contenido de fenoles libres y la cuantificación de proteínas en las hojas. Se observó en todos los casos un efecto positivo por la inocula- ción con estas rizobacterias, donde se destaca la cepa R5(15 con los mayores incrementos en los indicadores estudiados.

  3. Evaluation of DNA damage in the root cells of Allium cepa seeds growing in soil of high background radiation areas of Ramsar - Iran

    Energy Technology Data Exchange (ETDEWEB)

    Saghirzadeh, M. [Department of Basic Science, Gonabad University of Medical Sciences, Gonabad (Iran, Islamic Republic of); Gharaati, M.R. [Faculty of Science, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Mohammadi, Sh. [Nuclear Science and Technology Research Institute (NSTRI), Radiation Applications Research School, Tehran 11365-3486 (Iran, Islamic Republic of)], E-mail: smohammadi@aeoi.org.ir; Ghiassi-Nejad, M. [Faculty of Science, Tarbiat Modares University, Tehran (Iran, Islamic Republic of)

    2008-10-15

    Plants are unique in their ability to serve as in situ monitors for environmental genotoxins. We have used the alkaline comet assay for detecting induced DNA damage in Allium cepa to estimate the impact of high levels of natural radiation in the soils of inhabited zones of Ramsar. The average specific activity of natural radionuclides measured in the soil samples for {sup 226}Ra was 12,766 Bq kg{sup -1} whereas in the control soils was in the range of 34-60 Bq kg{sup -1}. A positive strong significant correlation of the DNA damage in nuclei of the root cells of A. cepa seeds germinated in the soil of high background radiation areas with {sup 226}Ra specific activity of the soil samples was observed. The results showed high genotoxicity of radioactively contaminated soils. Also the linear increase in the DNA damage indicates that activation of repair enzymes is not triggered by exposure to radiation in HBRA.

  4. Evaluación preliminar de la micorriza versículo-arbuscular en dos sistemas: pastizal y cebolla de bulbo Allium cepa

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    Muñoz F. Jaime Eduardo

    1993-12-01

    Full Text Available Se evaluó durante dos semestres la micorriza en dos sistemas: pastizal y cultivo de Allium cepa, en un mismo sitio con un contenido de P alto. Para el pastizal se tomaron muestras en cinco lotes identificando las especies presentes y su abundancia relativa, en A. cepa se tomaron muestras en cinco edades del cultivo. En ambos sistemas se evaluó porcentaje de infección por MVA (PI, número de esporas por 50 g de suelo (NES, se identificaron las especies de MVA y se obtuvo su frecuencia. En el pastizal la especie predominante Paspalum notatum presentó los mayores PI (16.2 y 15.4 y el mayor NES, Penisetum clandestinulll no adaptada a la zona presentó el menor PI (0.1% y el menor NES; para los dos semestres hubo correlación entre PI y NES y para cada variable a través de semestres, lo que indica que el comportamiento fue similar en las dos épocas. En Allium cepa, para los dos semestres, no se presentó infección por MVA en semillero y los PI de infección fueron muy bajos, menores de 5.3%, no obstante que la especie es considerada de alta dependencia de la MVA; esto puede deberse al alto contenido de P del suelo (167 ppm, y a la aplicación de fungicidas. En ambos sistemas las especies de MVA fueron las mismas, Glomus geosporum, Glomus mosseae, Glomus versiforme, Acaulospora longula, Glomus monosporum y Glolmus sp; Entrophospora infreguens no se presentó en A. cepa. Las especies predominantes en los dos sistemas fueron Glomus geosporum y Acaulospora longula.

    During two semesters Micorriza (VAM was evaluated in two systems: pastures and Allium cepa culture, in the same place, which had a high P content. For pastures were taken samples in five lots, identifying present species and their relative abundance. In A. cepa samples were taken in five culture ages, In both systems were evaluated infection percentage (lP for VAM, number of spores for 50 g of soil (NSS, were identified the VAM species and was obtained their frequency. At the pastures

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

    OpenAIRE

    Martínez Motas, Isabel Florentina

    2005-01-01

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

  6. Efectividad de cepas rizobianas nativas de sabana en Vigna unguiculata (L. Walp. cv. C4A-3

    Directory of Open Access Journals (Sweden)

    Juliana Mayz

    2010-12-01

    Full Text Available Título en inglés: Effectiveness of savannah native rhizobial strains in Vigna unguiculata (L. Walp. cv. C4A-3 Resumen Se estima que la población mundial se incrementará y demandará mayor cantidad de alimentos y uso de fertilizantes nitrogenados. En Venezuela, el frijol es altamente consumido y se cultiva en las sabanas orientales, cuyas características edáficas pueden afectar negativamente la población rizobiana. Estos planteamientos refuerzan la importancia de la evaluación de la flora rizobiana nativa, y enfatizan la necesidad de aumentar la explotación de la fijación biológica de nitrógeno. En este contexto, se evaluaron 6 cepas rizobianas en el cultivar C4A-3, aisladas, de frijol cv. Tejero Criollo y previamente catalogadas como efectivas (JV91, JV94 y JV101 e inefectivas (JV99, JV103, y JV104 en el cultivar TC9-6. El experimento se llevó a cabo en umbráculo por 45 días, donde además se incluyeron dos tratamientos control no inoculados. La suspensión de las cepas individualmente cultivadas se usó para inoculación. De acuerdo con la tipología de la nodulación (número de nódulos, peso total y por nódulo, tamaño y color, los valores de los parámetros de crecimiento (peso seco, altura y número de hojas del vástago y los estimados de la concentración de nitrógeno y nitrógeno total, las cepas JV91, JV99 y JV101, fueron las más efectivas en la fijación de nitrógeno. El nitrógeno total y la concentración de nitrógeno tuvieron una correlación significativa con peso seco, altura y número de hojas del vástago. Los resultados muestran la existencia de cepas efectivas en los suelos de sabana para este cultivar, y enfatizan la importancia de evaluar las cepas indígenas, antes de proceder a la inoculación con foráneas. Palabras clave: Rhizobium; frijol; fijación de nitrógeno; Venezuela. Abstract It is estimated that world-wide population will increase and demand higher amount of food and use of nitrogen

  7. Efecto protector de una cepa no virulenta contra la infección con una cepa virulenta de Trypanosoma cruzi en un modelo murino Protective effect of a non virulent strain against infection of a highly virulent strain of Trypanosoma cruzi in a murine model

    Directory of Open Access Journals (Sweden)

    C Zúñiga

    2007-01-01

    Full Text Available En el presente estudio se realizó una comparación en el desarrollo de la infección con 2.000 tripomastigotes, en ratones ACA, usando las cepas Tulahuen y Munantá de Trypanosoma cruzi, aisladas originalmente en Chile y Colombia, respectivamente. La cepa ACA se mostró como altamente susceptible a la infección con la cepa Tulahuen, muriendo el 100% de los animales dentro de las 3 semanas postinfección. Sin embargo, todos los ratones infectados con la cepa Munantá sobrevivieron a pesar de alcanzar mayores niveles de parasitemia. El estudio histopatológico de corazón mostró diferentes grados de parasitismo intracelular e infiltrado inflamatorio en relación con la cepa de parásito utilizada. En la infección con la cepa Munantá se pudo observar escasa presencia de pseudoquistes, en este tejido, con una discreta inflamación. Por el contrario, los tejidos de los animales infectados con la cepa Tulahuen mostraron un alto número de parásitos intracelulares y un severo proceso inflamatorio. Se investigó el posible efecto protector de una primoinfección con la cepa no virulenta Munantá frente a una posterior infección con la cepa virulenta Tulahuen. Los animales reinfectados con esta última cepa mostraron menores niveles de parasitemia, 100% de sobrevivencia y menor daño tisular.This study was carried out to compare the infection course of Trypanosoma cruzi in the ACA inbred mouse strain inoculated with 2000 blood trypomastigotes of the Tulahuen strain and the Colombian Munantá strain. Parasitaemia and mortality rates showed different patterns for both strains of the parasite. All the Tulahuen infected mice died within 3 weeks after infection, in contrast, all mice infected with the Munantá strain survived, although they showed higher level of parasitaemia. These results are in agreement with previous findings suggesting poor correlation between death and parasitaemia level. The histopathological study showed different degrees of

  8. UTILIZACIÓN DE CEPAS EFICIENTES DE HONGOS MICORRÍZICOS ARBUSCULARES EN EL DESARROLLO DE PORTAINJERTOS DE AGUACATE EN UN SUSTRATO SUELO-CACHAZA

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    Luis R. Fundora Sánchez

    2011-01-01

    Full Text Available El objetivo del presente trabajo fue evaluar el efecto de dos cepas eficientes de hongos micorrízicos arbusculares sobre indicadores de crecimiento y desarrollo en portainjertos de aguacate. La inoculación del producto a las semillas, se llevó a cabo mediante una pasta fluida compuesta por 1 kg del biofertilizante EcoMic® y 600 mL de agua. Con esta pasta, se recubrieron las semillas de los tratamientos 1 y 2 quedando conformado el esquema de la forma siguiente T1: semillas inoculadas con la cepa Glomus hoi-like, T2: semillas inoculadas con la cepa Glomus mosseae y T3: semillas no inoculadas. Se utilizó un germinador con cáscara de maní como lecho de germinación; a los 30 días después de la germinación las plantas fueron llevadas a bolsas, las cuales contenían un sustrato formado por suelo agrícola + cachaza en una relación (75 % : 25 % v/v. Las variables de crecimiento y desarrollo estudiadas fueron: altura del portainjerto, diámetro del tallo, número de hojas, longitud y ancho de las hojas, área foliar y tasa de crecimiento relativo; dentro de los parámetros micorrízicos se determinó el porcentaje de colonización radical, la densidad visual y el índice de eficiencia micorrízica. Los resultados encontrados demostraron, que la utilización de cepas eficientes de hongos micorrízicos arbusculares; estimula el desarrollo de los portainjertos de aguacate en condiciones de vivero lo cual repercute en la obtención de plantas de mayor calidad y a su vez constituyen una alternativa nutricional para este cultivo.

  9. Comparative effect of garlic (Allium sativum), onion (Allium cepa), and black seed (Nigella sativa) on gastric acid secretion and gastric ulcer

    OpenAIRE

    Bastaki, Salim

    2011-01-01

    Naheed Amir, Amina Al Dhaheri, Najla Al Jaberi, Fatma Al Marzouqi, Salim MA BastakiDepartment of Pharmacology and Therapeutics, Faculty of Medicine and Health Sciences, UAE University, Al Ain, United Arab EmiratesAbstract: Protective roles of raw and boiled garlic (Allium sativum) and onion (Allium cepa) in comparison with black seed (Nigella sativa) on acidified ethanol-induced gastric ulcers and gastric acid secretion in rats in vivo have been investigated. Raw or boiled Nigella sativa, gar...

  10. Neisseria gonorrhoeae produtora de penicilinase: primeira cepa isolada em São Paulo, SP (Brasil) Penicillinase producing Neisseria gonorrhoeae: the first strain isolated in S. Paulo, Brazil

    OpenAIRE

    Clovis Lombardi; Luiz Fernando de Góes Siqueira; Manuel Fernando Queiroz dos Santos Júnior; Waldemar Francisco; Walter Belda

    1985-01-01

    Relata-se o primeiro caso identificado de Neisseria gonorrhoeae produtora de penicilinase (NGPP) no Estado de São Paulo, Brasil, demonstrando a necessidade de mensurar os índices de prevalência destas cepas na população.This paper reports on the first case of penicillinase-producing Neisseria gonorrhoeae (PPNG) isolated in S. Paulo, Brazil, demonstrating the necessity of measuring the prevalence of these strains among the population.

  11. In Vitro Evaluation Of Selected Plant Extracts As Biocontrol Agents Against Black Mold Aspergillus Niger Van Tieghem Of Onion Bulbs Allium Cepa L.

    OpenAIRE

    SAIFELDIN A. F. EL-NAGERABI; Awad H. M. Ahmed; ABDULKADIR E. ELSHAFIE

    2015-01-01

    Black mold disease caused by Aspergillus niger V. Tiegh. is the most devastating infection occurs in onions Allium cepa L. under field and store conditions. The use of biocontrol agents is ecofriendly approach for controlling seedborne and soilborne diseases compared to the use of toxic synthetic fungicides. This study has been designed to assess the contamination levels of onion seeds with A. niger and its effect on seed germination and to evaluate the in vitro antifungal activity of Prunus ...

  12. Integrative structural annotation of de novo RNA-Seq provides an accurate reference gene set of the enormous genome of the onion (Allium cepa L.)

    OpenAIRE

    Kim, Seungill; Kim, Myung-Shin; Kim, Yong-Min; Yeom, Seon-In; Cheong, Kyeongchae; Kim, Ki-Tae; Jeon, Jongbum; Kim, Sunggil; Kim, Do-Sun; Sohn, Seong-Han; Lee, Yong-Hwan; Choi, Doil

    2014-01-01

    The onion (Allium cepa L.) is one of the most widely cultivated and consumed vegetable crops in the world. Although a considerable amount of onion transcriptome data has been deposited into public databases, the sequences of the protein-coding genes are not accurate enough to be used, owing to non-coding sequences intermixed with the coding sequences. We generated a high-quality, annotated onion transcriptome from de novo sequence assembly and intensive structural annotation using the integra...

  13. The Application of the Cluster Analysis in Recognizing Weather Patterns Conducive to Large and Small Crops of Mid-late Onion Cultivars (Allium cepa L.) in Poland

    OpenAIRE

    Robert KALBARCZYK

    2010-01-01

    This study uses 40 years valuable of data (1966-2005) obtained by the Polish Research Centre for Cultivar Testing and the Polish Institute of Meteorology and Water Management to recognize weather conditions conducive to large and small crops of onion (Allium cepa L.), more specifically-its mid-late cultivars cultivated in Poland. We found three clusters of agrometeorological conditions, determining different sizes of onion crops. Cluster no. 1 included observations which were characterized by...

  14. Aislamiento y selección de una cepa bacteriana degradadora de hidrocarburos a partir de suelos contaminados con petróleo

    Directory of Open Access Journals (Sweden)

    Rosa María Pérez Silva

    2008-01-01

    Full Text Available El conocimiento científico acerca del papel que desempeñan los microorganismos en el tratamiento de agentes contaminantes del medio ambiente como el petróleo, es esencial para prevenir y controlar los daños que puedan ocasionar los derrames o fugas de estos contaminantes. La degradación de petróleo es un proceso que puede ocurrir de forma natural por los microorganismos nativos de las zonas contaminadas aprovechando sus rutas metabólicas. Por esta razón, en estos momentos se prevé que los microorganismos pueden ofrecer esta posibilidad en tecnologías basadas en el uso de estos en la remediación de la contaminación ambiental por petróleo y sus derivados. En el presente trabajo, se estudió la biodegradación de petróleo por cepas aisladas de suelos contaminados con petróleo, mediante un aislamiento realizado por enriquecimiento secuencial utilizando petróleo Mesa 30/Puerto escondido (80 : 20 como única fuente de carbono y energía. Se aislaron 9 cepas bacterianas, cinco Gram negativas y cuatro Gram positivas, que fueron identificadas según el Manual Bergey's, 1994. Las pruebas bioquímicas evaluadas confirmaron que las cepas aisladas AT14, AT15, AT16, AT17 y AT18 corresponden a Pseudomonas aeruginosa. En este estudio, se seleccionó la cepa Pseudomonas aeruginosa AT18, por mostrar mayor crecimiento sobre petróleo como única fuente de carbono y energía al obtenerse 1,83 g/L de biomasa celular, lo que representa un 57 % de biodegradación de petróleo.

  15. Valgomojo svogūno (Allium cepa L.) ginogenezė ir homozigotinių linijų kūrimas

    OpenAIRE

    Juškevičienė, Danguolė

    2006-01-01

    Peculiarities of edible onions (Allium cepa L.) gynogenesis investigated in the dissertation work. Conditions for creation of dihaploid plants evaluated. Biological assumptions for preparation of methodical suggestions, that would enable improving of gynogenesis, determined. Stimulation effect of using TDZ and NAR in media on the formation of edible onion embryogenic tissue has been revealed for the first time. Characteristic higher frequency of gynogenesis of unfertilized flower of edible on...

  16. Evaluation of toxic, cytotoxic, mutagenic, and antimutagenic activities of natural and technical cashew nut shell liquids using the Allium cepa and Artemia salina bioassays.

    Science.gov (United States)

    Leite, Aracelli de Sousa; Dantas, Alisson Ferreira; Oliveira, George Laylson da Silva; Gomes Júnior, Antonio L; de Lima, Sidney Gonçalo; Citó, Antônia Maria das Graças Lopes; de Freitas, Rivelilson M; Melo-Cavalcante, Ana Amélia de C; Dantas Lopes, José Arimateia

    2015-01-01

    The cashew nut releases a substance that is known as cashew nut shell liquid (CNSL). There are both natural (iCNSL) and technical (tCNSL) cashew nut shell liquids. This study used an Artemia salina bioassay to evaluate the toxic effects of iCNSL and tCNSL cashew nut shell liquids. It also evaluated the toxicity, cytotoxicity, and mutagenicity of CNSL and its effects on the damage induced by copper sulfate (CuSO4·5H2O) on the meristems' root of Allium cepa. Effects of the damage induced by CuSO4·5H2O were evaluated before (pre-), during (co-), and after (post-) treatments. The iCNSL contained 94.5% anacardic acid, and the tCNSL contained 91.3% cardanol. The liquids were toxic to A. salina. Toxicity, cytotoxicity, and mutagenicity were observed with iCNSL compared with the negative control. Similarly, iCNSL failed to inhibit the toxicity and cytotoxicity of CuSO4·5H2O. The tCNSL was not toxic, cytotoxic, or mutagenic in any of the concentrations. However, the lowest iCNSL concentrations and all of the tCNSL concentrations had preventive, antimutagenic, and reparative effects on micronuclei and on chromosomal aberrations in the A. cepa. Therefore, protective, modulating, and reparative effects may be observed in the A. cepa, depending on the concentration and type of CNSL used. PMID:25861638

  17. Antioxidants in aqueous extract of Myristicafragrans (Houtt.) suppress mitosis and cyclophosphamide-induced chromosomal aberrations in Allium cepa L.cells

    Institute of Scientific and Technical Information of China (English)

    Akeem AKINBORO; Kamaruzaman Bin MOHAMED; Mohd Zaini ASMAWI; Shaida Fariza SULAIMAN; Othman Ahmad SOFIMAN

    2011-01-01

    In this study,freeze-dried water extract from the leaves of Myristica fragrans (Houtt.) was tested for mutagenic and antimutagenic potentials using the Allium cepa assay.Freeze-dried water extract alone and its combination with cyclophosphamide (CP) (50 mg/kg) were separately dissolved in tap water at 500,1000,2000,and 4000 mg/kg.Onions (A.cepa) were suspended in the solutions and controls for 48 h in the dark.Root tips were prepared for microscopic evaluation.2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radicals' scavenging power of the extract was tested using butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) as standards.Water extract of Myristica fragrans scavenged free radicals better than BHA,but worse than BHT.The extract alone,as well as in combination with CP suppressed cell division,and induced chromosomal aberrations that were insignificantly different from the negative control (P≤0.05).However,cytotoxic and mutagenic actions of CP were considerably suppressed.The observed effects on cell division and chromosomes of A.cepa may be principally connected to the antioxidant properties of the extract.The obtained results suggest mitodepressive and antimutagenic potentials of water extract of the leaves of M.fragrans as desirable properties of a promising anticancer agent.

  18. Caracterização de cepas do Trypanosoma cruzi isoladas de doentes nos quais foi realizado transplante de coração

    Directory of Open Access Journals (Sweden)

    Perla Natalia Bustos Lanura

    1995-12-01

    Full Text Available Três cepas do Trypanosoma cruzi foram, isoladas de pacientes com doença de Chagas crônica, receptores de coração por meio de tra?isplante. Houve caracterização delas através de modelo experimental baseado no emprego de camundongos, com avaliação de parasitismo, mortalidade e intensidade da inflamação no coração, além de análise do grau de parasitismo nesse órgão. Como controle, teve lugar comparação com o comportamento da já bem conhecida cepa Y. Ficaram caracterizadas atuações diferentes das cepas, ao serem valorizados os parâmetros citados, sem correlação rigorosa com as evoluções pós-transplantes, que sofrem a influência de vários fatores, entre os quais podem estar particularidades vinculadas ao parasitismo.

  19. CE-PA: A user`s manual for determination of controlling earthquakes and development of seismic hazard information data base for the central and eastern United States

    Energy Technology Data Exchange (ETDEWEB)

    Short, C.

    1995-05-01

    The CE-PA, Controlling Earthquake(s) through Probabilistic Analysis, software package developed at Lawrence Livermore National Laboratory (LLNL) is a research program used as part of a study performed for the US Office of Nuclear Regulatory Research Division Engineering project on Geosciences Issues in the revision of geological siting criteria. The objectives of this study were to explore ways on how to use results from probabilistic seismic hazard characterization (PSHC) to determine hazard-consistent scenario earthquakes and to develop design ground motion. The purpose of this document is to describe the CE-PA software to users. The software includes two operating system and process controllers plus several fortran routines and input decks. This manual gives an overview of the methodology to estimate controlling earthquakes in Section I. A descriptive overview of the procedures and the organization of the program modules used in CE-PA is provided in Section II. Section III contains four example executions with comments and a graphical display of each execution path, plus an overview of the directory/file structure. Section IV provides some general observations regarding the model.

  20. Evaluation of Toxic, Cytotoxic, Mutagenic, and Antimutagenic Activities of Natural and Technical Cashew Nut Shell Liquids Using the Allium cepa and Artemia salina Bioassays

    Directory of Open Access Journals (Sweden)

    Aracelli de Sousa Leite

    2015-01-01

    Full Text Available The cashew nut releases a substance that is known as cashew nut shell liquid (CNSL. There are both natural (iCNSL and technical (tCNSL cashew nut shell liquids. This study used an Artemia salina bioassay to evaluate the toxic effects of iCNSL and tCNSL cashew nut shell liquids. It also evaluated the toxicity, cytotoxicity, and mutagenicity of CNSL and its effects on the damage induced by copper sulfate (CuSO4·5H2O on the meristems’ root of Allium cepa. Effects of the damage induced by CuSO4·5H2O were evaluated before (pre-, during (co-, and after (post- treatments. The iCNSL contained 94.5% anacardic acid, and the tCNSL contained 91.3% cardanol. The liquids were toxic to A. salina. Toxicity, cytotoxicity, and mutagenicity were observed with iCNSL compared with the negative control. Similarly, iCNSL failed to inhibit the toxicity and cytotoxicity of CuSO4·5H2O. The tCNSL was not toxic, cytotoxic, or mutagenic in any of the concentrations. However, the lowest iCNSL concentrations and all of the tCNSL concentrations had preventive, antimutagenic, and reparative effects on micronuclei and on chromosomal aberrations in the A. cepa. Therefore, protective, modulating, and reparative effects may be observed in the A. cepa, depending on the concentration and type of CNSL used.

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

    Directory of Open Access Journals (Sweden)

    Paula M. Bermúdez D

    2014-01-01

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

  2. Análise das cepas de Streptococcus pneumoniae causadores de pneumonia invasiva: sorotipos e sensibilidade aos antimicrobianos

    Directory of Open Access Journals (Sweden)

    Cristina R. M. Yoshioka

    2011-02-01

    Full Text Available OBJETIVOS: Identificar os sorotipos de pneumococo mais frequentemente isolados de crianças internadas com pneumonia invasiva, comparar os sorotipos com os incluídos em vacinas conjugadas e analisar sua sensibilidade aos antimicrobianos mais utilizados na faixa etária pediátrica. MÉTODOS: Estudo descritivo, retrospectivo das pneumonias pneumocócicas identificadas em crianças internadas no hospital universitário da Universidade de São Paulo, no período de janeiro de 2003 a outubro de 2008. Os critérios de inclusão foram: faixa etária de 29 dias até 15 anos incompletos com diagnóstico clínico e radiológico de pneumonia e com cultura de sangue e/ou líquido pleural com crescimento de Streptococcus pneumoniae. RESULTADOS: Foram incluídas no estudo 107 crianças. Os sorotipos mais frequentes foram: 14 (36,5%, 1 (16,7%, 5 (14,6%, 6B (6,3% e 3 (4,2%. A proporção de sorotipos contidos na vacina conjugada heptavalente seria de 53,1%, na vacina 10-valente de 86,5% e na 13-valente seria de 96,9%. De acordo com os padrões do Clinical and Laboratory Standards Institute 2008, 100 cepas (93,5% de pneumococos foram sensíveis à penicilina (concentração inibitória mínima, CIM 8 µg/mL. Verificamos alta taxa de sensibilidade para as cepas testadas para vancomicina, rifampicina, ceftriaxone, clindamicina, cloranfenicol e eritromicina. CONCLUSÕES: Nossos resultados confirmam um expressivo impacto potencial das vacinas conjugadas, principalmente pela 10-valente e 13-valente, sobre os casos de pneumonias invasivas. Os resultados de sensibilidade à penicilina evidenciam que a opção terapêutica de escolha para o tratamento das pneumonias invasivas continua sendo a penicilina.

  3. Toxicidad biológica de cepas nativas de Bacillus thuringiensis Berliner en larvas de Tecia solanivora Povolny

    Directory of Open Access Journals (Sweden)

    Paola Martínez

    2011-11-01

    Full Text Available La biodiversidad microbiológica de los suelos del departamento de Boyacá aún no ha sido explorada en toda su magnitud y existen microorganismos, como en el caso de Bacillus thuringiensis Berliner (Bt, que pueden emplearse para el desarrollo de estrategias biológicas de control de plagas en el futuro. Por lo anterior, el presente trabajo evaluó la actividad biológica, expresada como  toxicidad, de cepas nativas de B. thuringiensis en la Polilla Guatemalteca  de  la  papa  Tecia  solanivora Povolny, una de  las plagas más  limitantes en el cultivo de papa en la región andina colombiana. Esta  evaluación  se  realizó con  aislados de  Bt obtenidos y conservados por el Grupo de Manejo Biológico de Cultivos (GMBC en el Laboratorio de Control Biológico de la UPTC, colectados de muestras de  suelo en  la Provincia Centro de Boyacá y  previamente  caracterizados  macro  y microscópicamente.  La   toxicidad  se  evaluó mediante bioensayos con larvas de primer instar de  T.  solanivora,  utilizando  el método  decontaminación superficial de cubos de papa. Se evaluó  la mortalidad  ocho  días  después  de montado  el  bioensayo  y  se  determinó, igualmente,  la Concentración letal media (Cl 50 de las cepas que presentaron  la mayor actividad  tóxica en  los  bioensayos  iniciales.  Los  aislamientosGMBC-B054, GMBC-B071, GMBC-B076, GMBC- B098, GMBC-B111 y GMBC-B117 fueron  los más activos, con Cl 50 de 1.08x106, 4.24x106, 5.12x106, 4.36x103, 3.56x103  y  1.19x104  esporas  · mL-1,respectivamente.

  4. Tipificación molecular por PCR-RFLPS de cepas trypanosoma sp. aisladas en campo y evaluación de ganados de la Orinoquia colombiana

    Directory of Open Access Journals (Sweden)

    Vera Víctor Julio

    2006-12-01

    Full Text Available En este estudio se presentan los primeros resultados obtenidos al utilizar como una herramienta diagnóstica,
    técnicas moleculares de PCR y RFLPs sobre la subunidad ribosomal 18S del DNA del Trypanosoma. La PCR-RFLPs
    se estandarizó al utilizar tres cepas de Trypanosoma (Trypanosoma vivax, Trypanosoma evansi y Trypanosoma theileri pertenecientes al Banco de Germoplasma de Hemoparásitos de Corpoica, las cuales fueron multiplicadas en ovinos de lana y purificadas por medio del método de cromatografía de intercambio iónico. Con la PCR semianidada se obtuvieron los primeros amplificados de las tres cepas de Trypanosoma entre 700 a 800 pb, y de 600 a 700 pb en la segunda amplificación. Usando las enzimas de digestión MspI y Eco57I se obtuvieron diferentes perfiles diferenciando las infecciones por Trypanosoma vivax, Trypanosoma evansi y Trypanosoma theileri. Con base en la información obtenida con las tres cepas de Tripanosoma, se trabajaron 70 muestras de sangre de ganados del piedemonte llanero, colectadas por el método del Buffy coat, los cuales fueron reportados como negativos a Trypanosoma bajo pruebas parasitológicas de Woo y extendido de sangre. De las 70 muestras bovinas, con la PCR se detectaron como animales positivos a trypanosoma un 7,14%, con niveles de sensibilidad en campo de la prueba de 25 trypanosomas/ml de sangre parasitada. De los animales positivos, los patrones de digestión obtenidos
    correspondieron a la cepa Trypanosoma theileri en un 80%, y un 20% a la cepa Trypanosoma vivax. Los resultados que se obtuvieron del estudio morfométrico en las especies T. vivax y T. evansi del Banco de Germoplasma de Corpoica, mostraron que el T. vivax es un parásito con mayor longitud (20-25 μm que el T. evansi (18-19 μm, aunque el flagelo libre de este último siempre fue mayor (7-9 μm al igual que el diámetro de su núcleo. En ambos parásitos la posición del núcleo fue central y la posición del quinetolasto

  5. Genotoxicity of Thermopsis turcica on Allium cepa L. roots revealed by alkaline comet and random amplified polymorphic DNA assays.

    Science.gov (United States)

    Ciğerci, İbrahim Hakkı; Cenkci, Süleyman; Kargıoğlu, Mustafa; Konuk, Muhsin

    2016-08-01

    This study was undertaken to evaluate genotoxic potential of Thermopsis turcica aqueous extracts on the roots of onion bulb (Allium cepa L.) by comet assay and random amplified polymorphic DNA technique. The Allium root growth inhibition test indicated that the EC50 and 2×EC50 values were 8 and 16 mg/ml concentrations of T. turcica aqueous extracts, respectively. The negative control (distilled water), positive control (methyl methane sulfonate, 10 mg/l) and 8 and 16 mg/ml concentrations of T. turcica extracts were introduced to the roots of onion bulbs for 24 and 96 h. The root growth, DNA damage in root cells and randomly amplified polymorphic DNA (RAPD) profiles of root tissue were used as endpoints of the genotoxicity. The comet assay clearly indicated that dose-dependent single strand DNA breaks in the root nuclei of onions were determined for the treatment concentrations of T. turcica extracts. In comparison to RAPD profile of negative control group, RAPD polymorphisms became evident as disappearance and/or appearance of RAPD bands in treated roots. The diagnostic and phenetic numerical analyses of RAPD profiles obviously indicated dose-dependent genotoxicity induced by Thermopsis extracts. In conclusion, the results clearly indicated that water extract of T. turcica has genotoxic potential on the roots of onion bulbs as shown by comet assay and RAPD technique. PMID:25550040

  6. Detection of GLV, OYDV and LYSV in potato onion (Allium cepa L.,Aggregatum group) by RT-PCR

    Institute of Scientific and Technical Information of China (English)

    XU Qijiang; CHEN Dian; TONG Youli; LI Yuhua

    2007-01-01

    Three pairs of primers were designed and synthesized from nucleotide sequences of garlic latent virus (GLV), onion yellow dwarf virus (OYDV), and leek yellow stripe virus (LYSV) by using PCR primer design software. The expected fragments about 170 bp,287 bp, and 191 bp were amplified by RT-PCR for GLV, OYDV, and LYSV, respectively in disease-infected plants of potato onion(Allium cepa L., Aggregatum group), but such fragments were not obtained from healthy-looking plants and virus-free seedlings of shoot-tips. The amplified products ofGLV, OYDV and LYSV were cloned into pGEM-T vectors, and transformed into Escherichia coli.JM109. The recombinant plasmids were obtained and sequenced. The nucleotide sequences were compared with corresponding viral nucleotide sequences reported in GenBank by performing a NCBI BLAST. The analysis showed that their homology attained 75% toplants was diluted to a series of 10-1 to 10-5 and the detection sensitivity of RT-PCR was 10-4 (about 4 ng). Thus, a method of identification and detection by RT-PCR of GLV, OYDV, and SLYV was established.

  7. Flavonol Glucoside and Antioxidant Enzyme Biosynthesis Affected by Mycorrhizal Fungi in Various Cultivars of Onion (Allium cepa L.).

    Science.gov (United States)

    Mollavali, Mohanna; Bolandnazar, Saheb Ali; Schwarz, Dietmar; Rohn, Sascha; Riehle, Peer; Zaare Nahandi, Fariborz

    2016-01-13

    The objective of this study was to investigate the impact of mycorrhizal symbiosis on qualitative characteristics of onion (Allium cepa L.). For this reason, five onion cultivars with different scale color and three different strains of arbuscular mycorrhizal fungi (Diversispora versiformis, Rhizophagus intraradices, Funneliformis mosseae) were used. Red cultivars, mainly 'Red Azar-shahr', showed the highest content in vitamin C, flavonols, and antioxidant enzymes. Mycorrhizal inoculation increased total phenolic, pyruvic acid, and vitamin C of onion plants. Considerable increase was observed in quercetin-4'-O-monoglucoside and isorhamnetin-4'-O-monoglucoside content in plants inoculated with Diversispora versiformis, but quercetin-3,4'-O-diglucoside was not significantly influenced. Analyses for phenylalanine ammonia-lyase (PAL) and antioxiodant enzyme activities such as polyphenol oxidase (PPO), catalase (CAT), and peroxidase (POD) revealed that all except PPO were enhanced by mycorrhizal inoculation. Overall, these findings suggested that mycorrhizal inoculation influenced biosynthesis of flavonol glucosides and antioxidant enzymes by increasing nutrient uptake or by induction of the plant defense system. PMID:26694086

  8. Biodecolorization of azo dye Remazol orange by Pseudomonas aeruginosa BCH and toxicity (oxidative stress) reduction in Allium cepa root cells.

    Science.gov (United States)

    Jadhav, Shekhar B; Surwase, Shripad N; Kalyani, Dayanand C; Gurav, Ranjit G; Jadhav, Jyoti P

    2012-11-01

    In this report a textile azo dye Remazol orange was degraded and detoxified by bacterium Pseudomonas aeruginosa BCH in plain distilled water. This bacterial decolorization performance was found to be pH and temperature dependent with maximum decolorization observed at pH 8 and temperature 30 °C. Bacterium tolerated higher dye concentrations up to 400 mg l(-1). Effect of initial cell mass showed that higher cell mass concentration can accelerate decolorization process with maximum of 92 % decolorization observed at 2.5 g l(-1) cell mass within 6.5 h. Effect of various metal ions showed Mn has inducing effect whereas Zn strongly inhibited the decolorization process at 5 mM concentration. Analysis of biodegradation products carried out with UV-vis spectroscopy, HPTLC and FTIR confirmed the decolorization and degradation of Remazol orange. Possible route for the degradation of dye was proposed based on GC-MS analysis. During toxicological scrutiny in Allium cepa root cells, induction in the activities of superoxide dismutase (SOD), guaiacol peroxidase (GPX) and inhibition of catalase (CAT) along with raised levels of lipid peroxidation and protein oxidation in dye treated samples were detected which conclusively indicated the generation of oxidative stress. Less toxic nature of the dye degraded products was observed after bacterial treatment.

  9. Nuclear lamina—like filaments and nuclear matrix in allium cepa as revealed by scanning electron microscopy

    Institute of Scientific and Technical Information of China (English)

    HAOSHUI

    1992-01-01

    In this study,freeze-fractured specimens of allium cepa root tip meristems were examined under the scanning electron microscope(SEM),This technique permitted the visualization of the outer membrane of the nuclear envelope with nuclear pore complexes and polyribosomes.Some of the cell nuclei prepared with this procedure had fissures of various widths on their nuclear envelopes through which the nuclear lamina-like filaments(LLF) undernearth the nucleoplasmic side of the envelopes were clearly visible.The diameters of these filaments veried between 25 and 125nm.Many of the LLFs showed granular thickenings at places,and were attached to the inner surface of nuclear envelope in some regions .Similar LLFs were also seen at the peripheries of the freeze-fractured faces of nuclei.Meanwhile,the spatial relation between the nuclear matrix filaments(NMF) and other nuclear structures(nucleoli,chromation and peripheral lamina-like filaments) was revealed in these fractured preparations.In addition,the methods and techniques in studying the nuclear lamina morphology and the roles played by NMFs in activities of various nuclear sturctures were discessed in brief.

  10. Genotypic variation in the sulfur assimilation and metabolism of onion (Allium cepa L.) I. Plant composition and transcript accumulation

    KAUST Repository

    McCallum, John A.

    2011-06-01

    Organosulfur compounds are major sinks for assimilated sulfate in onion (Allium cepa L.) and accumulation varies widely due to plant genotype and sulfur nutrition. In order to better characterise sulfur metabolism phenotypes and identify potential control points we compared plant composition and transcript accumulation of the primary sulfur assimilation pathway in the high pungency genotype \\'W202A\\' and the low pungency genotype \\'Texas Grano 438\\' grown hydroponically under S deficient (S-) and S-sufficient (S+) conditions. Accumulation of total S and alk(en)yl cysteine sulfoxide flavour precursors was significantly higher under S+ conditions and in \\'W202A\\' in agreement with previous studies. Leaf sulfate and cysteine levels were significantly higher in \\'W202A\\' and under S+. Glutathione levels were reduced by S- treatment but were not affected by genotype, suggesting that thiol pool sizes are regulated differently in mild and pungent onions. The only significant treatment effect observed on transcript accumulation in leaves was an elevated accumulation of O-acetyl serine thiol-lyase under S-. By contrast, transcript accumulation of all genes in roots was influenced by one or more treatments. APS reductase transcript level was not affected by genotype but was strongly increased by S-. Significant genotype × S treatment effects were observed in a root high affinity-sulfur transporter and ferredoxin-sulfite reductase. ATP sulfurylase transcript levels were significantly higher under S+ and in \\'W202A\\'. © 2011 Elsevier Ltd. All rights reserved.

  11. Influence of Allium ampeloprasum L. and Allium cepa L. essential oils on the growth of some yeasts and moulds

    Directory of Open Access Journals (Sweden)

    Kocić-Tanackov Sunčica D.

    2009-01-01

    Full Text Available Essential oils extracted from spices, as natural antimicrobial agents, attract particular attention due to their possible role in food protection from microorganisms, and their nontoxicity, in contrast to the synthetic preservatives. In this work, inhibitory effect of Allium ampeloprasum and two onions (Allium cepa, Junski srebrnjak and Kupusinski jabučar, essential oils in different concentrations (1, 4, 7 and 10% on three yeasts (Saccharomyces cerevisiae, Candida tropicalis and Rhodotorula sp. and three moulds (Aspergillus tamarii, Penicillium griseofulvum and Eurotium amstelodami was investigated. All three essential oils showed the strongest inhibitory effect against S. cerevisiae in concentration of only 1%. Among onions, Kupusinski jabučar essential oil had stronger influence to C. tropicalis, while Allium ampeloprasum essential oil did not show any influence on this yeast. Rhodotorula sp. was influenced only by Allium ampeloprasum essential oil. The strongest inhibitory effect on A. tamarii showed Kupusinski jabučar (57% of inhibition, in concentration of 10%, while on P. griseofulvum, the strongest influence showed Allium ampeloprasum essential oil (78.3% of inhibition, in concentration of 10%. Junski srebrnjak and Kupusinski jabučar essential oils, in concentrations of 7 and 10% respectively, completely inhibited the growth of E. amstelodami.

  12. Subcellular localization of cadmium in the root cells of Allium cepa by electron energy loss spectroscopy and cytochemistry

    Indian Academy of Sciences (India)

    Donghua Liu; Ingrid Kottke

    2004-09-01

    The ultrastructural investigation of the root cells of Allium cepa L. exposed to 1 mM and 10 mM cadmium (Cd) for 48 and 72 h was carried out. The results indicated that Cd induced several obvious ultrastructural changes such as increased vacuolation, condensed cytoplasm with increased density of the matrix, reduction of mitochondrial cristae, severe plasmolysis and highly condensed nuclear chromatin. Electron dense granules appeared between the cell wall and plasmalemma. In vacuoles, electron dense granules encircled by the membrane were aggregated and formed into larger precipitates, which increase in number and volume as a consequence of excessive Cd exposure. Data from electron energy loss spectroscopy (EELS) confirmed that these granules contained Cd and showed that significantly higher level of Cd in vacuoles existed in the vacuolar precipitates of meristematic or cortical parenchyma cells of the differentiating and mature roots treated with 1 mM and 10 mM Cd. High levels of Cd were also observed in the crowded electron dense granules of nucleoli. However, no Cd was found in cell walls or in cells of the vascular cylinder. A positive Gomori-Swift reaction showed that small metallic silver grains were abundantly localized in the vesicles, which were distributed in the cytoplasm along the cell wall.

  13. Padrão isoenzimático da cepa Y do Trypanosoma cruzi após quimioterapia específica Isoenzymatic pattern of Trypanosoma cruzi Y strain following specific chemoterapy

    Directory of Open Access Journals (Sweden)

    Rosângela Castro Silva

    1989-03-01

    Full Text Available Foi estudado o perfil isoenzimático da cepa Y do Trypanosoma cruzi isolada de camundongos tratados e não curados com o Nufurtimox (Bay 2502 ou com o Benzonidazol (Ro 7.1051, submetida à passagens em camundongos recém-nascidos e a seguir inoculada nos seguintes grupos experimentais: I - camundongos inoculados com a cepa Y resistente ao Nifurtimox e tratados com esta mesma droga; II - camundongos inoculdado com a cepa Y resistente ao Nifurtimox e tratados com o Benzonidazol e III - camundognos resistentes ao tratamento com o Benzonidazol e tratados com esta mesma droga. Os inóculos foram de 15 x 10 [elevado a 4 ] tripomastigotas sanguícolas. Houve aumento de resistência em relação a cepa original com a mesma droga e resistência cruzada. A cepa Y isolada dos animais não curados foi passada em cultura em meio Warren e preparados os extratos enzimáticos para a eletroforese das seguintes enzimas: GPI, PGM, ALAT e ASAT. Como controle isoenzimático foram utilizadas as cepas Peruana (Tipo I, 21 SF (Tipo II e Colombiana (Tipo III e duas amostras da cepa Y mantidas por diferentes período em cultura e em criopreservação dos extraidos enzimáticos. Não houve modificações do perfil isoenzimático da cepa Y, que Tipo I (Peruana e ao padrão das amostras da cepa Y com diferentes períodos de manutenção.The isoenzyme pattern of the Trypanosoma cruzi Y strain recovered from mice inoculated with 15 x 10 [raised to the power of 4] blood trypomastigotes and previously treated with either Bay 2002 (Nifurtimox orRo 7-1051 (Benzonidazol was analyzed in the following situations: a strain resistant to Bay 2502 and again treated with the same drug; b strain resistant to Bay 2502 and treated with Ro 7-1051; c strain resistant to Ro 7-1051 and treated with that same drug. Although marked drug resistance was noted in all cases, the isoenzyme pattern of the Y strain for GPI, PGM, ALAT and ASAT remained throughout the same. The pattern was similar to that

  14. Evaluación de cepas de Pseudomonas sp para el control de hongos fitopatógenos que afectan cultivos de interés económico

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    Pilar M. Villa

    2005-01-01

    Full Text Available Se promueve cada vez más disminuir el uso de los plaguicidas químicos que afectan al ecosistema, para lo cual se emplean diferentes alternativas entre las que se encuentra el control biológico con microorganismos o sus metabolitos entre los que se encuentran las Pseudomonas fluorescentes por las propiedades que presentan. El objetivo de este trabajo es la evaluación de cepas de Pseudomonas de la Colección de Cultivos del ICIDCA para ser empleadas en el control biológico que afectan cultivos de interés económico. Se evaluaron 7 cepas que producen sideróforos y metabolitos antimicrobianos frente al hongo Sclerotium rolfsii mediante cultivo dual en papa dextrosa Agar más King B y Agar Nutriente, determinando la inhibición del crecimiento micelial del hongo. Se observó que las 7 cepas inhiben el crecimiento de éste entre el 60 y 90 % por la producción de sideróforos y compuestos antibióticos lo que las hacen efectiva para el control biológico. Las mejores cepas fueron las cepas de las Pseudomonas sp. 13 y las Pseudomonas aeruginosa PSS, y 11, que las hace promisorias para el desarrollo de productos biológicos para el control de enfermedades fúngicas en cultivos de interés económico.

  15. Molecular characterization of Borrelia burgdorferi sensu lato strains isolated in the area of Belgrade, Serbia Caracterização molecular de cepas de Borrelia burgdorferi sensu lato isoladas na região de Belgrado, Sérvia

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    Elizabeta S. Ristanovic

    2007-03-01

    Full Text Available This is the first report of the molecular characterization and identification of Borrelia burgdorferi sensu lato strains isolated in Serbia. Isolates A1, A2 and M1, from Ixodes ricinus, belong to Borrelia burgdorferi sensu stricto, while isolate K1 from Apodemus flavicollis is a mixture of Borrelia afzelii and B. burgdorferi s.s.Trata-se do primeiro relato de identificação e caracterização molecular de cepas de Borrelia burgdorferi sensu lato isoladas na região de Belgrado, Sérvia. As cepas A1, A2 e M1, isoladas de Ixodes ricinus, pertencem à Borrelia burgdorferi sensu stricto, enquanto a cepa K1, isolada de Apodemus flavocollis é uma mistura de Borrelia afzelii e B. burgdorferi s.s.

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

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    Pedraza-Avilés Alberto González

    2002-01-01

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

  17. Actividad antioxidante e inhibidora de a-glucosidasa y a-amilasa de tres variedades de cebolla (Allium cepa L.

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    Leticia X. López-Martínez

    2014-01-01

    Full Text Available La cebolla (Allium cepa L. ha sido cultivada durante miles de años y es utilizada como un componente importante en la dieta del ser humano. Estudios recientes sugieren que su consumo puede reducir o prevenir problemas de salud como asma, enfermedades cardiovasculares y diabetes, debido a sus efectos antioxidantes. En este estudio se determinó el contenido de compuestos fenólicos totales, la capacidad antiradical y la inhibición de las enzimas α-glucosidasa y α-amilasa de extractos acuosos y etanólicos de tres variedades de cebolla (blanca, amarilla y morada. El contenido de compuestos fenólicos totales varió de 6.59 a 9.25 mg/100 g y la actividad antiradical expresada como % DPPH- se encontró entre 20.4% a 39.6% y de 46.8 a 89.2% para los extractos acuosos y etanólicos respectivamente. Todos los extractos etanólicos fueron capaces de inhibir la actividad α-glucosidasa y α-amilasa de 58% a 34%% y 33 y 22% respectivamente, mientras que los extractos acuosos fueron menos efectivos. Entre los extractos estudiados, el extracto etanólicos de cebolla morada presenta la mayor concentración de compuestos fenólicos totales y la mayor actividad antiradical e inhibidora de α-glucosidasa. Las diferencias encontradas entre la concentración de compuestos fenólicos y las distintas actividades estudiadas parecen depender del perfil único de compuestos fenólicos que posee cada variedad de cebolla.

  18. Induction of mitotic and chromosomal abnormalities on Allium cepa cells by pesticides imidacloprid and sulfentrazone and the mixture of them.

    Science.gov (United States)

    Bianchi, Jaqueline; Fernandes, Thais Cristina Casimiro; Marin-Morales, Maria Aparecida

    2016-02-01

    To evaluate the cytotoxic and genotoxic effects of low concentrations of pesticides in non-target organisms, seeds of Allium cepa were exposed for 24 h to the imidacloprid insecticide, sulfentrazone herbicide and to the mixture of them, followed by recovery periods of 48 and 72 h. Imidacloprid results indicated an indirect genotoxic effect by inducing different types of chromosome aberration (CA), mainly bridges and chromosomal adherences. Cells with micronucleus (MN) were not significant in the analyzed meristems. Moreover, the 72-h recovery tests indicated that the two lower concentrations of the insecticide (0.036 and 0.36 g L(-1)) had their genotoxic effects minimized after discontinuation of treatment, differently to the observed for the field concentration (3.6 g L(-1)). Sulfentrazone herbicide at field concentration (6 g L(-1)) caused cytotoxic effects by inducing nuclear fragmentation and inhibition of cell division. The other concentrations (0.06, 0.6 and 1.2 g L(-1)) indicated genotoxic effects for this herbicide. The concentration of 0.06 g L(-1) induced persistent effects that could be visualized both by the induction of CA in the recovery times as by the presence of MN in meristematic and F1 cells. The induction of MN by this lowest concentration was associated with the great amount of breakage, losses and chromosomal bridges. The mixture of pesticides induced genotoxic and cytotoxic effects, by reducing the MI of the cells. The chromosomal damage induced by the mixture of pesticides was not persistent to the cells, since such damage was minimized 72 h after the interruption of the exposure.

  19. In Vitro Study of Berberis vulgaris, Actinidia deliciosa and Allium cepa L. Antibacterial Effects on Listeria monocytogenes

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    Anzabi Younes

    2015-10-01

    Full Text Available Objective: One control method of pathogenic microorganisms is using synthetic chemical preservatives and antibiotics. Because of being generally recognized as safe, antibacterial compounds with organic origin are considered important for health. This study was done in order to investigate the antibacterial effects of methanol extracts of the Berberis vulgaris (Barberry, Actinidia deliciosa (Kiwi and Allium cepa L. (Onions on the standard strain (ATCC:19114 of Listeria monocytogenes (L. monocytogenes, as it seems that it is possible to find some important organic and health safe anti-Listerial compounds. Materials and Methods: After collecting the mentioned plants phytology study was done. Then methanol extracts of named plants were prepared and antibacterial effects of these plants against the mentioned strain of L. monocytogenes by the Disk Diffusion, minimum inhibitory concentration (MIC and minimal bactericidal concentration (MBC methods were performed. Also Ampicillin (10 μg/disc was used as the reference antibacterial substance. In order to find the relationship between antibacterial properties of plants extracts independent t test, chi-square and analysis of variance (ANOVA tests were used. Results: Results showed that the extracts of all the three studied plants had antibacterial effects on L. monocytogenes. Average diagonal of growing area in disk diffusion test for barberry, kiwi and onions in order was 12, 15.5 and 11 mm. Also MIC of mentioned plants extracts in order was 125, 62.5, and 125 μg/ml and MBC of named plants was 500, 250 and 500 μg/ ml, respectively. Conclusion: The results of this work showed that methanol extracts of kiwi had stronger anti-Listerial effect than barberry’s and onion’s extracts.

  20. Analysis of cytotoxicity and genotoxicity on E. coli, human blood cells and Allium cepa suggests a greater toxic potential of hair dye.

    Science.gov (United States)

    Maiti, Swati; Sasmal, Kankaayan; Sinha, Sudarson Sekhar; Singh, Mukesh

    2016-02-01

    Pharmaceuticals and personal care products (PPCPs) are among the most important emerging environmental contaminants in recent time. PPCPs include wide range of cosmetics, among which hair dyes, are immensely popular in modern society. However, impact of hair dye and its residual discharged to the environment in relation to human health and ecological imbalance have not been widely studied. Based on the result of initial survey among the group of populations of eastern India, three most popular and commonly used permanent hair dyes are selected. Working sample of dye is prepared as recommended on the instructions booklet of the hair dye. The effect of three dyes is studied on Escherichia coli, human red blood cells (RBC), white blood cells (WBC) and Allium cepa bulbs by growth inhibition, hemolysis, 3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide (3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) assay and A. cepa micronuclei assays respectively. The Lethal dose (LD) demonstrated significant differences among three dyes and the model systems. In vitro hemolytic assays performed on RBC, and MTT assays on WBC show the cytotoxic effects of hair dye. Significant growth inhibition of E. coli has also been noted. In addition, the root tips of A. cepa treated with the dye have shown major chromosomal abnormalities coupled with cell division retardation. Here low mitotic index confirm cell division retardation. Finally, results of in vitro studies of dye-DNA interactions demonstrate electrostatic interaction. Combing all these results it confirms that hair dyes are cytotoxic and may cause mutagenic effect on living cells irrespective of microbes, plant and animal system.

  1. Caracterização de cepas do Trypanosoma cruzi isoladas de doentes nos quais foi realizado transplante de coração

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    Perla Natalia Bustos Lanura

    1995-12-01

    Full Text Available Três cepas do Trypanosoma cruzi foram, isoladas de pacientes com doença de Chagas crônica, receptores de coração por meio de tra?isplante. Houve caracterização delas através de modelo experimental baseado no emprego de camundongos, com avaliação de parasitismo, mortalidade e intensidade da inflamação no coração, além de análise do grau de parasitismo nesse órgão. Como controle, teve lugar comparação com o comportamento da já bem conhecida cepa Y. Ficaram caracterizadas atuações diferentes das cepas, ao serem valorizados os parâmetros citados, sem correlação rigorosa com as evoluções pós-transplantes, que sofrem a influência de vários fatores, entre os quais podem estar particularidades vinculadas ao parasitismo.Three strains of Trypanosoma cruzi were isolated from Chagas' disease patients transplanted for heart failure, after cardiac transplantation, and were studied in an experimental model of Chagas' disease, in mice, with evaluation of parasitic load, mortality and extension of inflammatory infiltrates in the heart. These parameters were compared with the standard strain Y. The strains had differences in the studied parameters, but there was no clear relationship between those and post-transplant evolution of the patients. Probably the clinical response is multifactorial and derives only in part from biological characteristics of the infecting T. cruzi strain, as measured in our model.

  2. Analysis of cytotoxicity and genotoxicity on E. coli, human blood cells and Allium cepa suggests a greater toxic potential of hair dye.

    Science.gov (United States)

    Maiti, Swati; Sasmal, Kankaayan; Sinha, Sudarson Sekhar; Singh, Mukesh

    2016-02-01

    Pharmaceuticals and personal care products (PPCPs) are among the most important emerging environmental contaminants in recent time. PPCPs include wide range of cosmetics, among which hair dyes, are immensely popular in modern society. However, impact of hair dye and its residual discharged to the environment in relation to human health and ecological imbalance have not been widely studied. Based on the result of initial survey among the group of populations of eastern India, three most popular and commonly used permanent hair dyes are selected. Working sample of dye is prepared as recommended on the instructions booklet of the hair dye. The effect of three dyes is studied on Escherichia coli, human red blood cells (RBC), white blood cells (WBC) and Allium cepa bulbs by growth inhibition, hemolysis, 3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide (3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) assay and A. cepa micronuclei assays respectively. The Lethal dose (LD) demonstrated significant differences among three dyes and the model systems. In vitro hemolytic assays performed on RBC, and MTT assays on WBC show the cytotoxic effects of hair dye. Significant growth inhibition of E. coli has also been noted. In addition, the root tips of A. cepa treated with the dye have shown major chromosomal abnormalities coupled with cell division retardation. Here low mitotic index confirm cell division retardation. Finally, results of in vitro studies of dye-DNA interactions demonstrate electrostatic interaction. Combing all these results it confirms that hair dyes are cytotoxic and may cause mutagenic effect on living cells irrespective of microbes, plant and animal system. PMID:26544094

  3. Obtención por Ɣ-irradiación de cepas de Saccharomyces cerevisiae tolerantes a condiciones de cultivo rigurosas, para la producción de bioetanol

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    Sylvia Enid Vazquez Zeballos

    2013-01-01

    Full Text Available Con el objetivo de obtener nuevas cepas de levadura capaces de resistir condiciones rigurosas de cultivo se sometió un cultivo fresco de Saccharomyces cerevisiae M522 a Ɣ-irradiación. Se generó una colección de cepas y se evaluó su capacidad de crecimiento a elevadas concentraciones de azúcar y etanol. Se seleccionó una de las cepas y se estudió en ella el efecto de los productos de degradación de la lignina, oligómeros fenólicos metoxilados obtenidos de su despolimerización oxidativa por tratamiento biológico. Se estudiaron también las enzimas involucradas. Todos los cultivos fueron evaluados por absorbancia a 660 nm tras 24 horas de incubación a 37 ˚C. En cuanto a las fracciones fenólicas, se obtuvo el perfil por espectrofotometría UV y se identificaron enzimas laccasa, desmetilasa y lig-peroxidasa.Se obtuvo una cepa (SacSV-10 con las mismas características de cultivo que la M522 en YPD. Se logró cultivar la cepa en un caldo con 10 % de etanol, cepa que toleró el efecto de los productos de degradación de la lignina, así como una concentración de glucosa de 40 g/L, y en condiciones anaerobias se obtuvo una biomasa mayor que para la M522. En conclusión, SacSV-10 es un prometedor candidato para usar en producciones de alcohol a partir de residuos lignocelulósicos.

  4. EVALUACIÓN DE CEPAS NATIVAS DEL GÉNERO Azospirillum Y SU INTERACCIÓN CON EL CULTIVO DEL ARROZ

    OpenAIRE

    Mabel Pazos; Annia Hernández

    2001-01-01

    Catorce cepas nativas pertenecientes a la especie Azospirillum brasilense se caracterizaron en cuanto a su ca- pacidad de fijar el nitrógeno atmosférico. Se estudió su efecto en el cultivo del arroz (Oryza sativa), mediante el modelo Microcosmos, realizando determinaciones de la altura de las plantas inoculadas, masa fresca de la raíz y el contenido de fenoles libres y la cuantificación de proteínas en las hojas. Se observó en todos los casos un efecto positivo por la inocula- ción con e...

  5. Evaluation of Toxic, Cytotoxic, Mutagenic, and Antimutagenic Activities of Natural and Technical Cashew Nut Shell Liquids Using the Allium cepa and Artemia salina Bioassays

    OpenAIRE

    Aracelli de Sousa Leite; Alisson Ferreira Dantas; George Laylson da Silva Oliveira; Gomes Júnior, Antonio L.; Sidney Gonçalo de Lima; Antônia Maria das Graças Lopes Citó; de Freitas, Rivelilson M.; Melo-Cavalcante, Ana Amélia de C.; José Arimateia Dantas Lopes

    2015-01-01

    The cashew nut releases a substance that is known as cashew nut shell liquid (CNSL). There are both natural (iCNSL) and technical (tCNSL) cashew nut shell liquids. This study used an Artemia salina bioassay to evaluate the toxic effects of iCNSL and tCNSL cashew nut shell liquids. It also evaluated the toxicity, cytotoxicity, and mutagenicity of CNSL and its effects on the damage induced by copper sulfate (CuSO4·5H2O) on the meristems’ root of Allium cepa. Effects of the damage induced by CuS...

  6. Regulation of miR394 in Response to Fusarium oxysporum f. sp. cepae (FOC) Infection in Garlic (Allium sativum L)

    OpenAIRE

    Chand, Subodh K.; Nanda, Satyabrata; Joshi, Raj K.

    2016-01-01

    MicroRNAs (miRNAs) are a class of post-transcriptional regulators that negatively regulate gene expression through target mRNA cleavage or translational inhibition and play important roles in plant development and stress response. In the present study, six conserved miRNAs from garlic (Allium sativum L.) were analyzed to identify differentially expressed miRNAs in response to Fusarium oxysporum f. sp. cepae (FOC) infection. Stem-loop RT-PCR revealed that miR394 is significantly induced in gar...

  7. On the tissular parasitism of Trypanosoma cruzi y strain in swiss mice Sobre o parasitismo tecidual da cepa Y do Trypanosoma cruzi em camundongos albinos (Swiss-Webster

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    Maria Auxiliadora de Sousa

    1984-12-01

    Full Text Available A review of the tissular parasitism of Trypanosoma cruzi Y strain in Swiss mice was carried out. This strain parasitized preferentially smooth, skeletal and cardiac muscle fibers, with low transitory spleen and liver parasitism, as previously found by some Authors, although differing from other reports. These results can be related to the host genetical constitution and/or the degree of the strain virulence at the time of this study. Furthermore, we discuss that the high macrophagotropism reported for this strain in some instances could be an artificially induced condition resulting from its serial maintenance in mice, either for a longer time and/or by using young animals. The heavy parasitism and inflammation observed in the bladder, pancreas and spermatic duct of some inoculated mice, as well as the testis parasitization, were also noteworthy findings.Através deste trabalho fizemos uma revisão do parasitismo tecidual da cepa Y do Trypanosoma cruzi em camundongos albinos (Swiss-Webster. Esta cepa parasitou preferencialmente as fibras musculares lisas, esqueléticas e cardíacas, sendo baixo e transitório seu parasitismo do baço e fígado, conforme já observado por alguns Autores, embora diferindo de outros achados. Estes resultados podem estar relacionados com o padrão genético do hospedeiro e/ou com o grau de virulência da cepa por ocasião deste estudo. Além do mais, discutimos a possibilidade de que o intenso macrofagotropismo descrito para esta cepa em algumas ocasiões possa ser uma condição artificialmente induzida através de sua manutenção seriada em camundongos por tempo prolongado e/ou pelo uso de animais jovens. Também são dignos de nota, o intenso parasitismo e inflamação da bexiga, pâncreas e canal espermático de alguns animais inoculados, assim como, o encontro de ninhos de amastigotas no testículo.

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

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    María J. Valdés

    2008-08-01

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

  9. Caracterización de cepas y de plásmidos de Enterobacteriaceae portadores de ß-lactamasas de espectro extendido

    OpenAIRE

    Blanc Pociello, Vanessa

    2007-01-01

    La resistencia bacteriana a los antimicrobianos, y en particular la producción de ß- lactamasas plasmídicas de espectro extendido (BLEE), es un grave problema descrito principalmente en cepas de origen clínico. Sin embargo, no existen muchos datos sobre la prevalencia y la capacidad de difusión de estas resistencias en otros ambientes. Por ello, los objetivos de esta Tesis se enmarcan en un amplio proyecto coordinado cuya finalidad ha sido el estudio de la prevalencia de BLEE, cefamicinasas y...

  10. Efecto de lactoferrina bovina en la formación de biofilms en cepas clínicas de E. coli enteroagregativa

    OpenAIRE

    Cecilia Coveñas; Georgette Dextre; Diana Fernandez; Susan Mosquito; Theresa Ochoa

    2014-01-01

    Objetivos. Determinar el efecto de lactoferrina bovina (bLf) en la formación de biofilms en cepas clínicas de Escherichia coli enteroagregativa (EAEC), y si este efecto es independiente del hierro. Materiales y métodos. Se utilizaron dos métodos: (a) cualitativo, mediante observación directa por microscopia óptica, y (b) cuantitativo, lecturas de los valores de absorbancia mediante lector de ELISA en presencia de bLf en concentraciones de 0,01mg/mL y 1mg/mL, con y sin hierro, y no bLf (contro...

  11. Tipificación molecular por PCR-RFLPS de cepas trypanosoma sp. aisladas en campo y evaluación de ganados de la Orinoquia colombiana

    OpenAIRE

    Vera Víctor Julio; Cassalett Bustillo Elizabeth Regina

    2006-01-01

    En este estudio se presentan los primeros resultados obtenidos al utilizar como una herramienta diagnóstica,
    técnicas moleculares de PCR y RFLPs sobre la subunidad ribosomal 18S del DNA del Trypanosoma. La PCR-RFLPs
    se estandarizó al utilizar tres cepas de Trypanosoma (Trypanosoma vivax, Trypanosoma evansi y Trypanosoma theileri) pertenecientes al Banco de Germoplasma de Hemoparásitos de Corpoica, las cuales fueron multiplicadas en ovinos de lana y purificadas por medio ...

  12. Relations between boiling water test, standard germination test and field emergence of leek (Allium porrum L.) and onion (Allium cepa L.) seeds

    OpenAIRE

    Ismail Guvenc; Haluk C. Kaymak; Sibel Duman

    2012-01-01

    The aim of this study was to determine relations occurring between boiling water test, standard germination test and field emergence of leek (Allium porrum L.) and onion (Allium cepa L.) seeds. In this study, seeds of six lots ('Kalem', 'Ala', 'Ínegöl-A, B, C and D') from three cultivars of leek and seven onion cultivars ('Early Texas Grano' (ETG), 'Panku', 'Storm', 'Banko', 'Aki', 'Kisagün' and 'Banka') seeds were used as plant material and their viability was evaluated in boiling water test...

  13. Evaluación de una formulación para la conservación de cepas de Pseudomona aeruginosa

    OpenAIRE

    Nancy Burguet-Lago; Nelson Sierra-Prado; Miguel Acosta Estrada

    2014-01-01

    La humanidad tiene la responsabilidad histórica de solucionar uno de los problemas más importantes de los tiempos actuales: la conservación del medio ambiente. Mientras que la conservación de plantas y animales ha sido aceptada desde hace tiempo, solo recientemente es que ha sido recibido reconocida la necesidad de conservar la diversidad microbiana. Laboratorios LIORAD dispone de una colección de cultivos microbianos procedente de subcultivos primarios de cepas de referencia, donde se encont...

  14. RESPUESTA DE LA CANAVALIA ENSIFORMIS A LA INOCULACIÓN MICORRÍZICA CON GLOMUS CUBENSE (CEPA INCAM-4), SU EFECTO DE PERMANENCIA EN EL CULTIVO DEL MAIZ

    OpenAIRE

    Gloria M. Martín Alonso; Ramón Rivera Espinosa; Alberto Pérez Díaz; Lianne Arias Pérez

    2012-01-01

    Para evaluar la influencia del número de esporas de hongos micorrízicos arbusculares (HMA) en el suelo sobre la respuesta de la canavalia a la inoculación con una cepa eficiente de HMA, se realizaron varios experimentos con diferentes condiciones de contenido inicial de esporas y manejo de inoculantes micorrízicos: (grupo 1) suelos en los que nunca antes se había aplicado este tipo de biofertilizante, con un número inicial de esporas de HMA bajo; (grupo 2) suelos con alto número inicial de...

  15. Evaluation of the genotoxicity of zinc oxide-eugenol cement to Allium cepa L. - doi: 10.4025/actascibiolsci.v35i4.17925

    OpenAIRE

    Elisângela de Fátima Rezende; Maria Cristina Mendes-Costa; Johnson Campideli Fonseca; Alex de Oliveira Ribeiro

    2013-01-01

    Evaluation of the Genotoxicity of Zinc Oxide-Eugenol Cement in Allium cepa L. Dental materials can induce local and systemic effects. The Allium cepa assay was used to evaluate the genotoxicity and/or cytotoxicity of zinc oxide and eugenol (ZOE) at different proportions. The ZOE solution was tested at the concentration of 1 drop of eugenol (in each drop of liquid, the approximate concentration of eugenol is 85%) and 1 portion of zinc oxide cement (treatment I), and twice the concentration of ...

  16. Molecular characterization of Borrelia burgdorferi sensu lato strains isolated in the area of Belgrade, Serbia Caracterização molecular de cepas de Borrelia burgdorferi sensu lato isoladas na região de Belgrado, Sérvia

    OpenAIRE

    Elizabeta S. Ristanovic; Kayoko Kitamura; Toshiyuki Masuzawa; Marija J. Milutinovic; Radovan M. Cekanac; Novica T. Stajkovic; Danijela M. Zivanovic

    2007-01-01

    This is the first report of the molecular characterization and identification of Borrelia burgdorferi sensu lato strains isolated in Serbia. Isolates A1, A2 and M1, from Ixodes ricinus, belong to Borrelia burgdorferi sensu stricto, while isolate K1 from Apodemus flavicollis is a mixture of Borrelia afzelii and B. burgdorferi s.s.Trata-se do primeiro relato de identificação e caracterização molecular de cepas de Borrelia burgdorferi sensu lato isoladas na região de Belgrado, Sérvia. As cepas A...

  17. Evaluation of the genotoxicity of zinc oxide-eugenol cement to Allium cepa L. - doi: 10.4025/actascibiolsci.v35i4.17925

    Directory of Open Access Journals (Sweden)

    Elisângela de Fátima Rezende

    2013-07-01

    Full Text Available Evaluation of the Genotoxicity of Zinc Oxide-Eugenol Cement in Allium cepa L. Dental materials can induce local and systemic effects. The Allium cepa assay was used to evaluate the genotoxicity and/or cytotoxicity of zinc oxide and eugenol (ZOE at different proportions. The ZOE solution was tested at the concentration of 1 drop of eugenol (in each drop of liquid, the approximate concentration of eugenol is 85% and 1 portion of zinc oxide cement (treatment I, and twice the concentration of eugenol (treatment II. Treated roots appeared to be yellowish-brown, fewer in number, thicker and less turgid compared with the control, suggesting a cytotoxic activity of ZOE. A significant difference was found in the root size between the control and treatment II. This treatment reduced by 79% the size of the root compared with the control, and the mitotic index was 66%, indicating a 22.4% reduction relative to the control, which in turn evidenced the cytotoxicity of ZOE. The significant increase in anaphase bridges suggests a genotoxic effect.

  18. Estudio fisiológico de una cepa de levadura con potencialidades para el enriquecimiento proteico del bagazo de caña de azúcar

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    María Isabel Sánchez

    2007-01-01

    Full Text Available La producción de biomasa microbiana se presenta como una alternativa destinada a cubrir las necesidades nutricionales del hombre y los animales. Las levaduras son los microorganismos más ampliamente utilizados en la producción de proteína unicelular, fundamentalmente por poseer un elevado contenido de proteína, superior incluso al de los alimentos consumidos tradicionalmente. En el presente trabajo se realizó un estudio fisiológico de la cepa Pichia guilliermondii que tiene potencialidades para ser utilizada en un proceso de fermentación en estado sólido para obtener biomasa proteica. Esta cepa de levadura presentó una adecuada utilización de miel C como fuente de carbono y energía, tanto en cultivos sumergidos como en estado sólido. Toleró un amplio intervalo de pH en el medio de cultivo sin una merma apreciable en el crecimiento, no necesitó el suministro de extracto de levadura y utilizó adecuadamente la urea como fuente de nitrógeno.

  19. Caracterización inmunológica de cepas de Leishmania (Viannia panamensis aisladas de zonas endémicas de Colombia

    Directory of Open Access Journals (Sweden)

    Mónica Giraldo

    2001-04-01

    Full Text Available

    El 95% de los casos de leishmaniosis en Colombia son causados por L. (V panamensis (1; de ellos la mayoría corresponden a leishmaniosis cutánea; no obstante, esta especie también se asocia con cuadros de leishmaniosis mucosa y leishmaniosis difusa así como con recaídas (2. Si bien la diversidad de formas clínicas y la severidad de la leishmaniosis son el producto de la interacción entre el hospedero y el parásito en un contexto ecológico apropiado (3, es probable que existan diferencias en el parásito, aun entre cepas de la misma especie, que determinan el tipo de respuesta inmune establecida, lo cual condiciona la forma clínica de la enfermedad. Basados en este supuesto nos proponemos caracterizar la respuesta inmune inducida durante la infección murina experimental con diferentes cepas de L. (V panamensis aisladas de pacientes con distintas formas clínicas de la leishmaniosis.

     

  20. Systemic control of cell division and endoreduplication by NAA and BAP by modulating CDKs in root tip cells of Allium cepa.

    Science.gov (United States)

    Tank, Jigna G; Thaker, Vrinda S

    2014-01-01

    Molecular mechanism regulated by auxin and cytokinin during endoreduplication, cell division, and elongation process is studied by using Allium cepa roots as a model system. The activity of CDK genes modulated by auxin and cytokinin during cell division, elongation, and endoreduplication process is explained in this research work. To study the significance of auxin and cytokinin in the management of cell division and endoreduplication process in plant meristematic cells at molecular level endoreduplication was developed in root tips of Allium cepa by giving colchicine treatment. There were inhibition of vegetative growth, formation of c-tumor at root tip, and development of endoreduplicated cells after colchicine treatment. This c-tumor was further treated with NAA and BAP to reinitiate vegetative growth in roots. BAP gave positive response in reinitiation of vegetative growth of roots from center of c-tumor. However, NAA gave negative response in reinitiation of vegetative growth of roots from c-tumor. Further, CDKs gene expression analysis from normal, endoreduplicated, and phytohormone (NAA or BAP) treated root tip was done and remarkable changes in transcription level of CDK genes in normal, endoreduplicated, and phytohormones treated cells were observed.

  1. Selección de una cepa bacteriana y un medio de cultivo industrial para la producción de poli 3-hidroxibutirato

    Directory of Open Access Journals (Sweden)

    Arianna Núñez-Caraballo

    2012-01-01

    Full Text Available Se realizó un diseño estadístico de experimentos 32 con réplica en cada punto, con el objetivo de seleccionar una cepa y un medio de cultivo para la obtención de Poli 3- hidroxibutirato (PHB. Los resultados indicaron la selección de la cepa de Bacillus subtilis B/ 23-44-4 y un medio de cultivo compuesto por miel final de caña al 1 %, hidrolizado de levadura 1 g/l y sal común 2,5 g/l para la producción de poli-β-hidroxibutirato, con el que se logra la reducción de los costos de producción casi 6 veces por concepto de materias primas, a través de la sustitución de las fuentes de carbono y nitrógeno que hasta ahora se habían empleado.

  2. Mutagenic potential of pollutans in the water of the Paraíba do Sul river, Tremembé, SP, Brazil, using the Allium cepa test

    Directory of Open Access Journals (Sweden)

    Agnes Barbério

    2011-04-01

    Full Text Available The mutagenicity can be related to chromosomic breaks induced by environmental pollutants. The aim of this research was to characterize the mutagenic potential of the pollutants in the water of the Paraíba do Sul river, in Tremembé city, São Paulo State, Brazil, analyzing chromosomal changes in the meristematic cells of Allium cepa, in the summer (April and winter (August of 2008. The bulbs were exposed for 72 h to the treatments: water from river, Hoagland solution (negative control and 15 µg/L from MMS – methyl methanesulfonate (positive control. In each treatment, three bulbs were exposed and for each bulb, five slides were prepared. For mitotic index (MI and micronucleus (MN frequency rate, a total of 2,000 cells per root/slide were analyzed and 100 cells for the chromosome aberrations (CA. In April, the pollutants induced a high mutagenic potential in the meristematic cells of Allium cepa, the frequency rate of MN, stickiness and CA from non-identified type were greater than the negative control. In August, the only significant change found was the chromosome bridges. There was no significant change for MI. These results indicate that the effluents which have varied sources are inducing harmful effects on the bioindicator, therefore, it is important to keep biomonitoring and adopting effluents control measures. The measures are important because these waters are used primarily for public supply and irrigation.

  3. Evaluación de la producción experimental de enzimas coagulantes de leche utilizando cepas de Rhizomucor spp

    Directory of Open Access Journals (Sweden)

    Osmar Thomas Morillo

    2015-05-01

    Full Text Available Título en ingles: Evaluation of experimental production of milk-clotting enzymes using Rhizomucor spp strainsTítulo corto: Producción de enzimas coagulantes de lecheResumen: La producción experimental de enzimas coagulante de leche se llevó a cabo en un medio de cultivo de laboratorio durante 190 h de incubación, utilizando tres cepas certificadas de Rhizomucor pusillus,  R. miehei y dos especies nativas de Rhizomucor spp. BIOMI-12 y 13. La evaluación se realizó midiendo la concentración de glucosa y proteína durante la incubación, estimación de la productividad, actividad específica, índice fuerza de cuajo/actividad proteolítica en los extractos enzimáticos crudos, determinación de los pesos moleculares y actividad proteolítica en los extractos enzimáticos parcialmente purificado. Todas las cepas mostraron un consumo de glucosa similar, el mismo comportamiento se observó en el contenido de proteína, excepto la cepa BIOM-13. Los incrementos en el contenido de proteínas después del descenso, coincidieron con la máxima actividad coagulante registrada por cada cepa, siendo el extracto crudo de la cepa BIOMI-13 la de mayor actividad coagulante (148,15 FC, productividad (3,09 FC/h, índice fuerza de cuajo/actividad proteolítica (142,60 FC/U y actividad específica (1.062,00 FC/mg. Los extractos enzimáticos parcialmente purificados de las cepas R miehei 37, Rhizomucor spp BIOM-12 y 13, presentaron proteínas con pesos moleculares en aproximadamente 22,6 y 46,52 KDa, mientras el extracto R pusillus 39 presentó una banda adicional de 39,6 KDa. En el zimograma se observó para todas las cepas actividad proteolítica en las bandas comprendidas entre 40-50 KDa y 20-22 KDa, no así para el R pusillus 36, donde fue escasa. Finalmente se determinó que la cepa BIOMI-13, tiene la mayor capacidad para producir enzimas coagulantes de la leche.Palabras clave: renina microbiana, fuerza de cuajo, actividad proteolítica, productividad

  4. Oxidative potential of ultraviolet-A irradiated or nonirradiated suspensions of titanium dioxide or silicon dioxide nanoparticles on Allium cepa roots.

    Science.gov (United States)

    Koce, Jasna Dolenc; Drobne, Damjana; Klančnik, Katja; Makovec, Darko; Novak, Sara; Hočevar, Matej

    2014-04-01

    The effect of ultraviolet-A irradiated or nonirradiated suspensions of agglomerates of titanium dioxide (TiO(2)) or silicon dioxide (SiO(2)) nanoparticles on roots of the onion (Allium cepa) has been studied. The reactive potential of TiO(2) nanoparticles, which have photocatalytic potential, and the nonphotocatalytic SiO(2) nanoparticles with the same size of agglomerates was compared. The authors measured the activity of antioxidant enzymes glutathione reductase, ascorbate peroxidase, guaiacol peroxidase, and catalase as well as lipid peroxidation to assess the oxidative stress in exposed A. cepa roots. A wide range of concentrations of nanoparticles was tested (0.1-1000 µg/mL). The sizes of agglomerates ranged in both cases from 300 nm to 600 nm, and the exposure time was 24 h. Adsorption of SiO(2) nanoparticles on the root surface was minimal but became significant when roots were exposed to TiO(2) agglomerates. No significant biological effects were observed even at high exposure concentrations of SiO(2) and TiO(2) nanoparticles individually. Plants appear to be protected against nanoparticles by the cell wall, which shields the cell membrane from direct contact with the nanoparticles. The authors discuss the need to supplement conventional phytotoxicity and stress end points with measures of plant physiological state when evaluating the safety of nanoparticles. PMID:24812678

  5. Cytological changes in meristematic cells of Allium cepa L. root tip treated with extracts from callus of Catharanthus roseus (L. G. Don

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    Agnieszka Pietrosiuk

    2014-02-01

    Full Text Available The effect of an ethanolic extract from callus of Catharanthus roseus on Allium cepa root cells divisions was investigated. Two lines: white and green callus, were established on solid B5 medium with IAA 1 mg/l and kinetin 0.1 mg/l. The HPLC analysis of callus extracts showed the presence of indole alkaloids, however not known pharmacologically active alkaloids or derivatives used in semisynthesis (vinblastine, ajmalicine, serpentine, yohimbine, vindoline and catharanthine have been found. The ethanolic extract of C. roseus callus inhibited the number of mitoses in Allium cepa root tip cells. Short (1-3 hours treatment resulted in an increase in the index of late prophases, with characteristic light spaces, and the index of metaphases with twisted chromosomes forming an equatorial plate or irregular structures of c-metaphases. At the same time, the percentage of anaphases and telophases decreased significantly. Longer treatment of the root tip inhibited mitotic activity, stopping it completely already after 12 hours. Interphase nuclei became at first denser and homogeneous, eventually their structure became , partitioned into zones and formation of chromatin territories, with distinct large nucleoli has been observed. Electron microscope observations revealed well developed rough endoplasmic reticulum and thick, invaginating cell membrane.

  6. Comparison of cytotoxic and genotoxic effects of plutonium-239 alpha particles and mobile phone GSM 900 radiation in the Allium cepa test.

    Science.gov (United States)

    Pesnya, Dmitry S; Romanovsky, Anton V

    2013-01-20

    The goal of this study was to compare the cytotoxic and genotoxic effects of plutonium-239 alpha particles and GSM 900 modulated mobile phone (model Sony Ericsson K550i) radiation in the Allium cepa test. Three groups of bulbs were exposed to mobile phone radiation during 0 (sham), 3 and 9h. A positive control group was treated during 20min with plutonium-239 alpha-radiation. Mitotic abnormalities, chromosome aberrations, micronuclei and mitotic index were analyzed. Exposure to alpha-radiation from plutonium-239 and exposure to modulated radiation from mobile phone during 3 and 9h significantly increased the mitotic index. GSM 900 mobile phone radiation as well as alpha-radiation from plutonium-239 induced both clastogenic and aneugenic effects. However, the aneugenic activity of mobile phone radiation was more pronounced. After 9h of exposure to mobile phone radiation, polyploid cells, three-groups metaphases, amitoses and some unspecified abnormalities were detected, which were not registered in the other experimental groups. Importantly, GSM 900 mobile phone radiation increased the mitotic index, the frequency of mitotic and chromosome abnormalities, and the micronucleus frequency in a time-dependent manner. Due to its sensitivity, the A. cepa test can be recommended as a useful cytogenetic assay to assess cytotoxic and genotoxic effects of radiofrequency electromagnetic fields.

  7. Systemic Control of Cell Division and Endoreduplication by NAA and BAP by Modulating CDKs in Root Tip Cells of Allium cepa

    Directory of Open Access Journals (Sweden)

    Jigna G. Tank

    2014-01-01

    Full Text Available Molecular mechanism regulated by auxin and cytokinin during endoreduplication, cell division, and elongation process is studied by using Allium cepa roots as a model system. The activity of CDK genes modulated by auxin and cytokinin during cell division, elongation, and endoreduplication process is explained in this research work. To study the significance of auxin and cytokinin in the management of cell division and endoreduplication process in plant meristematic cells at molecular level endoreduplication was developed in root tips of Allium cepa by giving colchicine treatment. There were inhibition of vegetative growth, formation of c-tumor at root tip, and development of endoreduplicated cells after colchicine treatment. This c-tumor was further treated with NAA and BAP to reinitiate vegetative growth in roots. BAP gave positive response in reinitiation of vegetative growth of roots from center of c-tumor. However, NAA gave negative response in reinitiation of vegetative growth of roots from c-tumor. Further, CDKs gene expression analysis from normal, endoreduplicated, and phytohormone (NAA or BAP treated root tip was done and remarkable changes in transcription level of CDK genes in normal, endoreduplicated, and phytohormones treated cells were observed.

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

    Directory of Open Access Journals (Sweden)

    J. Jaime

    2010-12-01

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

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

    Directory of Open Access Journals (Sweden)

    J. Mantilla

    2010-01-01

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

  10. Infección por Helicobacter pylori en la Ciudad de La Habana, Cuba.Prevalencia de las cepas cagA positivas

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    Beatriz Gutiérrez

    2005-12-01

    Full Text Available Existe una gran falta de información acerca de la infección por Helicobacter pylori en los países de la región del Caribe. Nuestros objetivos en este estudio fueron determinar la prevalencia, la resistencia a los antibióticos y los factores de virulencia de la bacteria. La medida de la prevalencia de la infección por H. pylori se determinó en un grupo de pacientes a los que se les practicó una endoscopia en tres centros hospitalarios de La Ciudad de La Habana, lo que nos permitió evaluar la resistencia a la claritromicina y la presencia de cagA + en las cepas obtenidas. De las endoscopias realizadas se obtuvieron 117 biopsias gástricas, procedentes de tres centros hospitalarios de La Ciudad de La Habana, Cuba: Instituto de Oncología, Instituto de Gastroenterología y el Hospital Calixto García. Las biopsias fueron mantenidas a –70 ºC para posterior cultivo en tres medios diferentes (dos selectivos y uno no selectivo y su posterior incubación por 7 días a 37 ºC en una atmósfera de microaerofilia. La presencia de H. pylori fue identificada por la presencia de diferentes enzimas (oxidasa, catalasa, ureasa. Se realizó la extracción del DNA y la PCR, donde se utilizó el primer H2761676 y se amplificó con 397 fragmentos del gen cagA. La susceptibilidad a la claritromicina fue medida por el método de difusión en gel. Diagnóstico endoscópico: (1 cáncer gástrico; (19 úlcera duodenal; (8 úlcera gástrica; (89 dispepsias no ulcerosas, incluyendo (62 gastritis; (9 hernia hiatal; (2 reflujo biliar; (1 pólipo gástrico; (15 panendoscopias normales. Del total de 117 biopsias realizadas, 83 fueron positivas a la infección por H.pylori (70,9% . De las 35 cepas a las que se les realizó presencia de cagA+ resultaron positivas 31 (88,5%. Solo el 3% de las cepas fueron resistentes a la claritromicina. La prevalencia de la infección por H. pylori en la población sintomática de La Ciudad de La Habana es la misma que la reportada en

  11. Isolation of Egg Cells from Allium cepa L.%洋葱卵细胞的分离

    Institute of Scientific and Technical Information of China (English)

    陈美灵; 于金金; 吴晓琛; 魏冬梅; 田惠桥

    2012-01-01

    Viable egg cells of Allium cepa L. were isolated using enzymic digestion and mechanical dissection. The onion ovules were incubated in an enzymic solution for 50~110 min and then peeled its two intaguments. The outline of embryo sac in nucellus was seen clearly. Using a dissecting needle cutting necellus transversely and pushing its micropyle part, three cells of egg apparatus could be released from cut end of the nucellus. The egg cell could be separated with two synergids, reaching the purpose of isolation of onion egg cell. Enzymes are very important for isolating egg cell, and in optimal enzyme solution containing 0.02% Pectolyse Y-23, 0.08% Pectinase (Serva), 0.05% Cellulase (Onozuka RS), 0.05% Hemicellulase (Sigma), 10 egg cells (41.67%) could be isolated from 24 ovules in 1 h. With embryo sac development, two synergids display dimorphism in size. The isolation of onion egg cells makes a base for its in vitro fertilization, and provides the condition to study onion egg development using methods of molecular biology.%将洋葱的胚珠置于酶液中酶解50~110 min后剥去其珠被,可清楚地看到珠心中的胚囊轮廓.用解剖针将珠心从中部横切,然后挤压其珠孔部位,卵器细胞从胚珠的切口处逸出.再用显微操作仪的玻璃针将卵细胞和两个助细胞分开,达到分离洋葱卵细胞的目的.酶对分离卵细胞具有重要作用,在最佳的酶液浓度[0.02%果胶酶Y23、0.08%果胶酶(Serva)、0.05%纤维素酶和0.05%半纤维素酶]下酶解胚珠110 min后,解剖1h可从24个胚珠中分离出10个卵细胞(41.67%).随着胚囊的发育,两个助细胞的体积出现明显的二形性.洋葱生活卵细胞的分离为开展洋葱离体受精建立了基础,也为研究洋葱卵器细胞的发育创造了条件.

  12. ESTUDIO DE LA ASOCIACIÓN Gluconacetobacter diazotrophicus-VIANDAS TROPICALES EN SUELO FERRALÍTICO ROJO.I. SELECCIÓN DE CEPAS EFECTIVAS PARA LA BIOFERTILIZACIÓNDE BONIATO, YUCA Y MALANGA

    Directory of Open Access Journals (Sweden)

    B. Dibut

    2010-01-01

    Full Text Available El interés de la comunidad científica internacionalpor la bacteria endófita Gluconacetobacter diazotrophicus,microorganismo fijador de nitrógeno atmosférico y productorde sustancias promotoras del crecimiento vegetal, se haincrementado en los últimos años. Por lo que teniendo en cuentasu potencial agrobiológico y los escasos estudios sobre elefecto que puede provocar la aplicación de productos elaboradosa partir de la fermentación de cepas efectivas, se diseñó estainvestigación, con el objetivo de seleccionar una cepa deGluconacetobacter diazotrophicus efectiva para estimular elcrecimiento, desarrollo y rendimiento de viandas tropicales,como son el boniato (Ipomea batatas Lam., la yuca (Manihotesculenta, Crantz y la malanga (Xanthosoma spp., cultivadossobre suelo un Ferralítico Rojo. La cepa INIFAT Abn1, aisladadel cultivo del boniato, fue la más promisoria para incrementarlos diferentes indicadores en los tres cultivos, con incrementosen valores de estimulación entre 23 y 46 %. Se demostró laimportancia de contar con una colección de amplia diversidadpara realizar una selección adecuada, así como la no existenciade una relación directa cultivo de procedencia-efectividad dela cepa.

  13. Biomodelo para la evaluación de cepas atenuadas como candidatos vacunales contra el cólera humano. I. Estudio de la virulencia, capacidad de colonización y adherencia a la mucosa intestinal

    Directory of Open Access Journals (Sweden)

    Reynaldo Oliva

    2008-04-01

    Full Text Available El cólera continúa siendo en muchos países un problema para la salud humana, manteniéndose como una enfermedad epidémica o endémica que afecta tanto a niños como adultos y causa la muerte en casos no tratados. Una vacuna viva oral contra esta enfermedad puede ser la solución. En el presente trabajo se seleccionó y aplicó un biomodelo para la evaluación de cepas atenuadas genéticamente de Vibrio cholerae como candidatas vacunales contra el cólera. La virulencia, capacidad de colonización y adherencia a la mucosa intestinal de las cepas fueron evaluadas mediante el uso de ratones neonatos de 2 a 4 días de nacidos de la línea Balb/c, con un peso entre 1,5-2 g. Los resultados obtenidos con este biomodelo demostraron que las cepas atenuadas genéticamente son no virulentas, colonizan y se adhieren a la mucosa intestinal. Se concluye que el biomodelo utilizado permite la evaluación y selección de cepas candidatas para vacunas vivas orales contra el cólera.

  14. Antimicrobial susceptibility of coagulase-negative Staphylococci isolated from mastitic cattle in Brazil Susceptibilidade antimicrobiana de cepas de Staphylococci coagulase-negativa isoladas de leite de bovinos com mastite no Brasil

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    T.R.O. Machado

    2008-02-01

    Full Text Available Um total de 109 cepas de Staphylococci coagulase-negativa foi isolado de leite de vacas com mastite clínica e subclínica, em 35 fazendas, situadas em nove estados brasileiros, no período de fevereiro a maio de 2005. Os isolados foram investigados em relação a susceptibilidade in vitro a diversos agentes antimicrobianos. A resistência à penicilina foi a observação mais freqüente (93,5%, seguida por sulfonamida (88,9%, novobiocina (88,6% e ampicilina (85,3%. Todas as cepas examinadas mostraram resistência a pelo menos uma das drogas antimicrobianas testadas. Cepas apresentando resistência múltipla foram extremamente comuns, com 10,0% dos microrganismos isolados apresentando resistência a todas as drogas antimicrobianas. Os resultados obtidos indicaram que as cepas de Staphylococci coagulase-negativas, isoladas no Brasil, apresentaram um alto grau de resistência a antimicrobianos. Estes resultados são, provavelmente, uma conseqüência da pressão devida ao uso intensivo de drogas antimicrobianas.

  15. CEPA实施绩效评估与香港经贸战略发展走向探析%CEPA implementing performance evaluation and HK economy and trade strategy development trend probing

    Institute of Scientific and Technical Information of China (English)

    徐晓迪

    2012-01-01

    2003年签订的《内地与香港关于建立更紧密经贸关系的安排》(CEPA),至今已经接近整整10年的时间,本文通过测算CEPA实施以来对香港地区、澳门地区和大陆产生的制度绩效,同时分析了对香港地区经贸发展的巨大拉动作用,最后对后CEPA时代香港经贸发展进行了展望和预测。%"The mainland and Hong Kong Closer Economic Partnership Arrangement"(CEPA) signed in 2003 which has been nearly 10 years.This paper calculates the CEPA performance in Hong Kong area,Macao area and the mainland China.And have a special analysis on the extreme effect of CEPA on Hong Kong economic and trade development.Finally,the post CEPA era of Hong Kong economic and trade development is prospected.

  16. Desenvolvimento e avaliação de uma cepa knockout de Brucella abortus obtida pela deleção do gene virB10 Development and evaluation of a strain of Brucella abortus gotten by the knockout of the virB10 gene

    OpenAIRE

    Fabiane G. de Souza; Ana L.A.R. Osório; Bárbara G. Csordas; Rafael Q. Prado; Carina Elisei; Cleber O. Soares; Araújo, Flábio R; Stênio P Fragoso; Grácia M.S. Rosinha

    2009-01-01

    Brucella spp. são bactérias gram-negativas, intracelulares facultativas que são patogênicas para muitas espécies de mamíferos causando a brucelose, uma zoonose difundida mundialmente. Por isso a busca de alternativas de controle mais eficientes se faz necessário como o desenvolvimento de novas cepas que possam ser testadas como potenciais imunógenos. Neste estudo realizou-se a deleção do gene virB10 da cepa S2308 de Brucella abortus gerando uma cepa knockout provavelmente incapaz de produzir ...

  17. Atividade antiproliferativa e mutagênica dos extratos aquosos de Baccharis trimera (Less. A. P. de Candolle e Baccharis articulata (Lam. Pers. (Asteraceae sobre o sistema teste de Allium cepa Antiproliferative and mutagenic activities of aqueous extract of Baccharis trimera (Less. A. P. de Candolle and Baccharis articulata (Lam. Pers. (Asteraceae on the Allium cepa test system

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    J.M. Fachinetto

    2009-01-01

    Full Text Available As espécies medicinais Baccharis trimera e Baccharis articulata, nativas no sul do Brasil, são muito utilizadas na medicina popular. Este estudo objetivou avaliar o potencial efeito citotóxico destas infusões sobre o ciclo celular de Allium cepa. Ramos de duas populações de cada espécie coletados durante os estádios vegetativo e reprodutivo (floração foram usados para preparar infusões em duas concentrações: 15 mg mL-1 e 75 mg mL-1. Células das pontas de raízes Allium cepa são usadas como sistema teste in vivo. Foram preparadas lâminas através da técnica de esmagamento. As células foram analisadas em todo o ciclo celular de A. cepa, totalizando 4000 células para cada grupo de bulbos. O índice mitótico (IM foi calculado e realizado análise estatística através do teste Qui-quadrado (c² = 0,05. Os resultados mostraram que as infusões de B. trimera nas duas populações causaram redução do IM em relação ao controle, mas não entre as concentrações, em ambos estádios utilizados. Os extratos de B. articulata também apresentaram redução do IM em relação ao controle, sendo que uma das populações apresentou diferença do IM entre as concentrações nos dois estádios, o que não ocorreu na outra população. Com relação à presença de células com aberrações cromossômicas, esta ocorreu em todas as populações estudadas. Os resultados indicaram que os extratos dessas espécies apresentaram efeito antiproliferativo e mutagênico para as concentrações estudadas, não possuindo diferença nesses efeitos quanto ao estádio de desenvolvimento das plantas.The medicinal species Baccharis trimera and Baccharis articulata, which are native to the south of Brazil, are extensively used in popular medicine. This study aimed to evaluate the potential cytotoxic effect of these infusions on the cell cycle of Allium cepa. Branches of two populations of each species collected during the vegetative and reproductive

  18. Efeito genotóxico e antiproliferativo de Mikania cordifolia (L. F. Willd. (Asteraceae sobre o ciclo celular de Allium cepa L.

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    M.G. Dias

    2014-06-01

    Full Text Available As plantas com potencial medicinal têm sido muito utilizadas para o tratamento de doenças no Brasil. O objetivo deste estudo foi avaliar o efeito genotóxico e antiproliferativo de infusões de Mikania cordifolia (L.F. Willd. sobre o ciclo celular de Allium cepa L. Foram coletadas duas populações no município de Santa Maria, Rio Grande do Sul, e, para cada uma, foram preparados dois tratamentos em duas concentrações: 4g/500mL e 16g/500mL, além de um controle positivo composto por 10% de glifosato em 90% água, um herbicida amplamente utilizado com conhecido potencial genotóxico, e de um controle negativo composto por água destilada. Após período de 24 horas, as radículas foram coletadas das infusões, fixadas em etanol-ácido acético (3:1 por 24 horas e estocadas em etanol 70%. Foram analisadas células em todas as fases do ciclo celular de A. cepa, totalizando 2500, para cada grupo de bulbos. Os índices mitóticos (IM foram calculados e submetidos à análise estatística pelo teste χ² a 5%. Os resultados mostraram que, em ambas as populações de M. cordifolia, houve redução do IM de todos os tratamentos em relação ao controle negativo. Em ambas as populações, obteve-se aumento nos valores dos índices mitóticos em função do aumento da concentração da infusão. Ocorreram aberrações cromossômicas em ambas as populações estudadas. Concluiu-se que as infusões de M. cordifolia, nas concentrações estudadas, possuem efeito antiproliferativo e mutagênico sobre o ciclo celular de A. cepa.

  19. Citotoxicidade e genotoxicidade da água do rio Subaé (Humildes, Bahia, Brasil usando Allium cepa L. como bioindicador

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    Jacqueline Ramos Machado Braga

    2015-01-01

    Full Text Available Ao longo dos anos, o rio Subaé na Bahia tem sido impactado por atividade industrial pelo lançamento de efluentes tóxicos em suas águas. O presente estudo analisou os efeitos citotóxicos e genotóxicos provocados pela água do trecho deste rio que banha o município de Humildes-BA, utilizando o teste do Allium cepa. Amostras de água foram obtidas em três pontos de coleta (PI, PII e PIII para as análises de parâmetros fisico-químicos. Bulbos de A. cepa foram colocados por 72 h para germinação nas amostras de água em triplicata. As radículas foram submetidas por 12-h a 4 oC, fixadas em Carnoy por 12-h e coradas com técnica de Feulgen. Foram analisadas 6.500 células/tratamento. A citotoxicidade foi avaliada pelo índice mitótico (IM e a genotoxicidade, por anormalidades cromossômicas (AC. Os testes fisico-químicos revelaram que PI e PIII apresentavam valores de OD, DBO5 e DQO alterados. O teste de toxicidade indicou que houve inibição do crescimento das raízes nos pontos PI (10,3 % e PII (10,6 %, quando comparados ao controle negativo (11,9 %. No PI, foram encontrados 6,2 % de ACs, 6 % em PII e 5,4 % em PIII, valores acima do controle positivo (3 %, evidenciando o efeito genotóxico nos pontos estudados. A partir dos resultados, pode-se inferir que as águas do Rio Subaé podem conter substâncias que provavelmente estão afetando o ciclo celular do A. cepa, sendo importante que outras análises sejam realizadas em diferentes estações do ano, para melhor monitoramento das condições ambientais locais.

  20. Cinética de degradación del naftaleno por células inmovilizadas húmedas de Bacillus alcalophilus cepa IDO-225

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    Roberto Rafael Núñez Moreira

    2004-01-01

    Full Text Available Numerosas han sido las investigaciones sobre el estudio de la biorremediación para su aplicación en la lucha para combatir la contaminación ambiental por hidrocarburos. El Instituto de Oceanología del Ministerio de Ciencia, Tecnología y Ambiente, ha trabajado desde 1988 en el aislamiento y conservaci ón de bacterias marinas que sean capaces de degradar el petróleo. Actualmente, cuenta con cuatro bioproductos degradadores de petróleo en medio marino denominados BIOIL, K-BIOIL, BIOIL-FC e IDO-225. En el presente trabajo, se demuestra por Espectroscopia Infrarroja de las muestras extraídas a los 3, 6, 9, 12 y 15 d de contacto de las células húmedas inmovilizadas de Bacillus alcalophilus cepa IDO-225 en el medio de degradación con el naftaleno, un hidrocarburo del petróleo, que estas son capaces de degradar el naflateno como única fuente de carbono y energía. La degradación de este hidrocarburo por las células inmovilizadas de esta cepa se lleva a cabo mediante un mecanismo que se basa en un modelo cinético de segundo orden correspondiente a un mecanismo de metil-oxidación y b-oxidación, al igual que las células libres de dicha cepa, pero con la diferencia de que en el caso de las células inmovilizadas, el término cuadrático (metil-oxidación es mayor y el término lineal (b-oxidación es menor que en las células libres. En este mecanismo se produce acetil-CoA, el cual se incorpora al ciclo de los acidos tricarboxílicos para formar dióxido de carbono, agua y coenzimas reducidas, las cuales se dirigen a la cadena de transporte electrónica para obtener energía en forma de ATP y garantizar la síntesis de compuestos esenciales y la obtención de energía.

  1. Selección de cepas nativas con actividad Quitino-Proteolítica de Bacillus sp. aisladas de suelos tropicales Selecting native

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    Beatriz Adriana Rodas Junco

    2009-10-01

    Full Text Available Bacillus sp. strains having chitinolytic and proteolytic activity which have been isolated from tropical soils Resumen: El objetivo de este trabajo fue la selección de cepas nativas del género Bacillus con actividad quitinolítica y proteolítica, en suelo tropical en la costa de Oaxaca, México. Se aislaron 150 cepas, de las cuales 22 fueron seleccionadas por presentar actividad quitinolítica y proteolítica. Dicha actividad se evaluó por la formación de halo de hidrólisis alrededor de la colonia en medios de cultivo suplementados con quitina coloidal al 5% y leche descremada al 1% respectivamente. Las cepas LUM B001, B003, B013, B015 y B065 presentaron mayor actividad quitinolítica y proteolítica, por lo que tienen el potencial para ser evaluadas en control biológico de hongos fitopatógenos. Se encontró al género Bacillus distribuido en suelos cultivados y no cultivados, no se encontraron diferencias estadísticas según el cultivo establecido (PPalabras clave: método de hidrólisis; quitina coloidal; quitinasas; proteasas.  Abstract: This work was aimed at selecting native strains from the Bacillus genus having chitinolytic and proteolytic activity from soil from the tropical coast of Oaxaca, Mexico. 150 strains were isolated, 22 of which were selected as they presented chitinolytic and proteolytic activity. Such activity was assessed by the formation of a hydrolysis halo around the colony in culture media supplemented with 5% colloidal chitin and 1% skimmed milk. The LUM B001, B003, B013, B015 and B065-chitin strains presented higher quitinolytic and proteolytic activity, thereby having the potential for being evaluated in the biological control of phytopathogenic fungi. The Bacillus genus was found in cultivated and uncultivated soils; no statistical differences were found according to established crop (p Key words: Hydrolysis method; colloidal chitin; chitinases; proteases.

  2. Comportamento fisiológico de goiabeira serrana quando multiplicada por mergulhia de cepa Physiological behavior of feijoa multiplied by stool layring

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    MS. Mielke

    1994-04-01

    Full Text Available Com o objetivo de estudar alguns fatores fisiológicos envolvidos na formação e desenvolvimento de raízes em mudas de goiabeira serrana (Feijoa sellowiana Berg, multiplicadas por mergulhia de cepa, foi realizado um experimento em Pelotas-RS, com mudas decepadas em julho de 91 e sobre as quais foi realizada amontoa em outubro de 91. A avaliação foi feita em agosto de 92, sendo observadas as variáveis: teor de clorofila total, área foliar, numero e diâmetro de brotações, número e percentagem de brotações enraizadas e peso da matéria seca das raízes. As variáveis teor de clorofila, área foliar e diâmetro médio das brotações não apresentaram influência sobre a matéria seca das raízes. O incremento no número de brotações causou um aumento no número de brotações enraizadas, entretanto, não apresentou influência na percentagem de brotações enraizadas. O aumento no número de brotações por cepa ocasionou um decréscimo em seu diâmetro médio. É demonstrado que é possível multiplicar plantas de goiabeira serrana através de mergulhia de cepa.The aim of this research was to study some physiological factors involved in root growth and development in sprouts of feijoa Feijoa settowiana Berg., multiplied by stool layring. The experiment was conducted in Pelotas,RS, Brazil, using sprouts cut in July 91, which were covered with soil in October 91. In August 92 the following variables were evaluated: total chlorophyll content, leaf area, stool number and diameter, number and percentage of rooted stools and root dry-matter weight. The variables chlorophyll content, leaf area and stool average diameter, did not show influence on root dry matter. The increase in number of stools caused an increase in the number but not in the percentage of rooted stools. The increase in stool number per plant caused a decrease in stool average diameter. It is demonstrated that it is possible to multiply feijoa plants through stool layring.

  3. Citotoxicity of food dyes sunset yellow (E-110, bordeaux red (E-123, and tatrazine yellow (E-102 on Allium cepa L. root meristematic cells Citotoxicidade dos corantes alimentares amarelo crepúsculo (E-110, vermelho bordeaux (E-123 e amarelo tartrazina (E-102 em células meristemáticas de raízes de Allium cepa L.

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    Keiva Maria Silva Gomes

    2013-03-01

    Full Text Available The objective of this study was to evaluate the cytotoxic effect of the food dyes sunset yellow, bordeaux red, and tartrazine yellow on the cellular cycle of Allium cepa L. Each dye was evaluated at the doses of 0.4 and 4.0 mL, at the exposure times of 24 and 48 hours in root tip cells of Allium cepa L. Slides were prepared and cells were analyzed during the whole cell cycle for cellular aberrations totaling 5,000 total cells for each dose evaluated. The mitotic index was calculated, and statistical analysis was performed using the Chi-squared test (p Este estudo teve por objetivo avaliar o efeito citotóxico dos corantes alimentares amarelo crepúsculo, vermelho bordeaux e amarelo tartrazina sobre o ciclo celular de Allium cepa L. Cada corante foi avaliado nas doses de 0,4 e 4,0 mL, nos tempos de exposição de 24 e 48 horas, em células de pontas de raízes de Allium cepa L. Prepararam-se lâminas e analisaram-se células, em todo o ciclo celular, e a presença de aberrações celulares, totalizando 5.000 células para cada dose avaliada. Foi calculado o índice mitótico e a análise estatística foi feita por meio do teste quiquadrado (p < 0,05. Os resultados mostraram que os três corantes, nas doses e tempos de exposição avaliados, foram citotóxicos às células do sistema-teste utilizado. Estudos adicionais de citotoxicidade devem ser conduzidos para se somar a estes resultados e, assim, avaliar, com propriedade, a ação destes três corantes em nível celular.

  4. Respuesta serológica y tiempo de saneamiento en rebaños bovinos con brucelosis vacunados con Cepa 19 o Cepa RB-51; Xª Región, Chile Serologic response and time to eradication in herds with brucellosis vaccinated with strain 19 or strain RB-51; 10th Region, Chile

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    M RAMIREZ

    2002-01-01

    Full Text Available Se comparó la respuesta serológica y el tiempo de saneamiento en rebaños bovinos con brucelosis, vacunados con vacuna Cepa 19 o Cepa RB-51. Se estudiaron los registros serológicos de 79 rebaños de la provincia de Valdivia, Xª región de Chile. Los rebaños se habian incorporado al Programa de Erradicacion de Brucelosis Bovina entre 1996 y 1999, y al momento de este estudio se encontraban bajo la condicion de "rebaño saneado". Veintiséis rebaños, con 540 vacas y una seroprevalencia inicial de 14.1%, fueron vacunados con la vacuna Cepa 19 y 53 rebaños, con 1104 vacas y una seroprevalencia inicial de 7.6%, recibieron Cepa RB-51. Periódicamente se colectaron muestras de suero sanguíneo y se examinaron para anticuerpos de Brucella spp. usando las pruebas de Rosa de Bengala y Fijacion de Complemento. Se evaluaron las seroprevalencias, el tiempo de saneamiento y los intervalos de tiempo dentro de éste, el número de exámenes y el lapso de tiempo entre los exámenes. Sesenta y seis de 369, vacas, previamente negativas vacunadas con Cepa 19, seroconvirtieron, pero ninguna de las 917 vacas vacunadas con RB-51 seroconvirtió. El tiempo de saneamiento para los rebaños vacunados con Cepa 19 fluctuó desde 304 a 1025 días (mediana 481 días, y para los rebaños vacunados con Cepa RB-51 desde 140 a 753 días (mediana 401 días; p = 0.003. El tamaño del rebaño, las políticas de reemplazo, el tipo de asistencia veterinaria y la severidad de los signos clínicos de brucelosis no afectaron los lapsos de tiempo. Los rebaños con Cepa 19 fueron muestreados en promedio 4.4 veces y los rebaños con Cepa RB-51 fueron muestreados solo 3.4 veces (p The serologic response to brucellosis vaccination and the time to eradication of brucellosis from herds were compared in dairy cattle vaccinated with either vaccine strains 19 or RB-51. Serologic records from 79 herds from the Province of Valdivia, 10th region of Chile, were evaluated. Herds had been

  5. A comparison study on the anti-leech effects of onion (Allium cepa L and ginger (Zingiber officinale with levamisole and triclabendazole

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    Bahmani Mahmoud

    2013-01-01

    Full Text Available Introduction: Leech may indwell in mucosa of the pharynx, tonsil, esophagus, nose, nasopharyngeal and rarely in larynx of hosts, however, the effective drugs against this parasite is scarce. This study was aimed to evaluate and compare the anti-leech effect of methanolic extract of onion (Allium cepa L and ginger (Zingiber officinale with levamisole and triclabendazole. Materials and Methods: In this study, 60 leeches (Limnatis nilotica were collected from south of Ilam. The anti-leech effect of methanolic extract of onion and ginger in comparison with levamisole and triclabendazole drugs (positive controls were evaluated. Distilled water was used as negative control. Paralysis and death of leeches were recorded in 720 minutes. Results: Lethal effect of methanolic extract of ginger against Limnatis nilotica was equal to levamisole and more than triclabendazole and methanolic extract of onion. Conclusion: Ginger equal to levamisole has anti-leech activity and its methanolic extract might be used against Limnatis nilotica.

  6. Effects of water soluble oncostatic fraction from Rheum officinale Baill. rhizomes on Allium cepa root meristem. III. Morphological changes in cytoplasm

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    A. Dawidowicz-Grzegorzewska

    2015-05-01

    Full Text Available Spiral concentric and linear configurations of membraneous structures were observed in the cytoplasm of fixed meristematic cells from the root apex of Allium cepa under the light microscope. They appeared after incubation in sublethal and lethal conditions in Rheum ofiicinale rhizome extracts. During postincubation these structures disappeared. They were interpreted as ER membranes. On the basis of literature data the physiological significance of these structures is discussed. It would seem that they are an indication of enhanced metabolic activity evoked either exogenously by various injuries as a form of defence reaction of the protoplast or endogenously during cytodifferentiation. Prolonged treatment in ,noxious conditions causes the ER membranes to transform into inactive myelin structures

  7. Caracterización de germoplasma de cebollín (Allium cepa var. Aggregatum, en el municipio de Gibara, provincia de Holguín

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    Hubert Rodríguez García

    2010-01-01

    Full Text Available Se colectaron y estudiaron 18 accesiones de cebollín (Allium cepa var Aggregatum entre los productores del municipio Gibara se plantaron en las fincas de los productores de la CCS Mario Muñoz Gibara. El estudio se realizo en el período comprendido de enero del 2005 a diciembre del 2006, con el objetivo de realizar una caracterización del germoplasma para determinar las variedades existentes en del municipio. Entre los principales resultados obtenidos se identificaron dos variedades en el agroecosistema: Bola Roja de bulbos de color rojo violáceo, redondos globoso y pungencia fuerte y la variedad Amarillo Largo de bulbos amarillo naranja, fusiformes-oblongos y de pungencia media.

  8. Análisis de la interacción soya-cepa (bradyrhizobium japonicum) x ambiente, en oxisoles de la orinoquia colombiana

    OpenAIRE

    Valencia, Rubén; Ligarreto M., Gustavo

    2012-01-01

    La Orinoquia colombiana y en particular las sabanas de la altillanura, representa una vasta región con ventajas comparativas y competitivas para la producción de soya. La especie se asocia con bacterias del género Bradyrhizobium para suplir, parcial o totalmente, los requerimientos de nitrógeno. Esta asociación es variable y de alta especificidad huésped-rizobio. La investigación tuvo como propósito determinar la interacción existente entre variedades de soya, cepas del género Bradyrhizobium ...

  9. Occurrence of fungus Rhizopus sp in bioassays with Allium cepa germinated in the presence of uranium to study the effect of natural radioactivity

    Energy Technology Data Exchange (ETDEWEB)

    Xavier, Magno N.; Oliveira, Andressa L.; Maffei, Eliane M.D.; Campos, Simara S., E-mail: simaracampos@gmail.com [Universidade Estadual do Sudoeste da Bahia (UESB), Vitoria da Conquista, BA (Brazil). Departamento de Ciencias Exatas e Tecnologicas; Gennari, Roseli F. [Universidade de Sao Paulo (USP), SP (Brazil). Instituto de Fisica. Departamento de Fisica Nuclear

    2015-07-01

    The demographic and global economic growth has promoted increasing power consumption. In this context, several studies point to nuclear energy as being promising to meet such demand. Although Brazil composes the seventh position in the world ranking of uranium reserves, the ore is still little explored in Brazil, considering its vast existing arsenal. On the one hand, despite nuclear energy has brought great benefits, technological and socio-economic development, it generates controversy about environmental contamination and risks to public health. Studies on this subject indicate that areas where uranium ore concentration is high, natural environmental radiation exposure levels are already higher than in other regions. The aim of this study is to observe the simple germination of the bio-indicator (Allium cepa), typically used to assess potential chromosomal aberrations, suffer any adverse effect caused by natural radiation uranium. The choice of this bio-indicator is based on its potential for evaluating the mutation caused by countless chemical compounds. Four treatments with three replicates were designed. In each treatment, 10 seeds of onion A. cepa without any pesticides were packed in the Petri dish lined with germination paper and room temperature (25°C) was kept until the root reaches approximately 1cm long. As a result, growth of the fungus Rhizopus sp was observed, in the experiments where uranium ore was added. It is important to mention according to the literature, this fungus can cause serious infections (and often fatal) in humans and animals, due to its high growth rate and also to their ability on surviving in relatively high temperatures. (author)

  10. Caracterización de tres cepas bacterianas capaces de fijar nitrógeno y biodegradar hidrocarburos aisladas de un suelo de la Patagonia

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    A.J. Acuña

    2010-01-01

    Full Text Available El objetivo de este trabajo fue caracterizar tres microorganismos capaces de biodegradar hidrocarburos en ausencia de nitrógeno aislados a partir de un suelo de la Patagonia con una larga historia de contaminación por petróleo y sus derivados. Para ello se aislaron tres cepas bacterianas de un suelo patagónico con baja concentración de nitrógeno y contaminado con hidrocarburos. Estos fueron identificados por ARNr 16S y ácidos grasos de membrana. También se estudiaron sus perfiles de biodegradación de hidrocarburos en presencia y en ausencia de nitrógeno con hidrocarburos alifáticos, cíclicos, aromáticos y poliaromáticos. La capacidad de realizar fijación biológica de nitrógeno se estudió por reducción de acetileno y detección del gen nifD. Por otro lado, se realizó un estudio por desarrollo en cultivo líquido para conocer la adaptación a diferentes pH, entre 5 y 9, temperatura, de 15 a 65 °C, y concentraciones crecientes de NaCl entre 0 y 3M. Los microorganismos aislados correspondieron a los géneros Pseudomonas, Bacillus y Gordonia, todos con capacidad de fijar nitrógeno. Las cepas biodegradaron casi la totalidad de los hidrocarburos ensayados en presencia y ausencia de nitrógeno y tuvieron una buena adaptación a los cambios de pH, temperatura y concentración de NaCl, demostrando una buena adaptación a los principales factores de estrés en los suelos patagónicos.

  11. Características biológicas de una cepa de Trypanosoma cruzi en un modelo murino y análisis de supervivencia

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    Nicolás Suárez

    2009-04-01

    Full Text Available Conocer las características biológicas de una cepa de Trypanosoma cruzi, procedente de Tiabaya, Arequipa, Perú, y determinar la supervivencia de los ratones inoculados con relación a la dosis infectante y al sexo. Se utilizaron 14 ratones BALB/C-53 (machos y hembras de 30 días. Los grupos I y II fueron inoculados por vía intraperitoneal con 1,8 x 105 y 1,8 x 104 trypomastigotes metacíclicos de T. cruzi, respectivamente; el grupo III con 1,5 x 107 trypomastigotes sanguíneos. El grupo control (IV recibió solo solución salina fisiológica al 0,9 %. Los parásitos fueron evaluados en sangre periférica de los ratones. El análisis de supervivencia fue realizado por el método de Kaplan-Meier, test de Logaritmo de rangos y Wilcoxon al 95 % de nivel de confianza. Se encontraron formas delgadas y gruesas de T. cruzi. La letalidad fue 100 % al día 40 postinfección (pi. La parasitemia fue detectada desde el 6to hasta el 40mo día pi y el pico máximo global (6747 parásitos fue observado al 29no día pi. Existen diferencias significativas en la supervivencia de los ratones inoculados de acuerdo a la dosis por la prueba de Logaritmo de rangos (p = 0,0202. La cepa de T. cruzi, procedente de Tiabaya, Arequipa es de mediana virulencia. La supervivencia de los ratones infectados está relacionada a la dosis de inoculación.

  12. Susceptibilidad "in vitro" de cepas de Cryptococcus a 5 drogas antifungicas "In vitro" susceptibility of Cryptococcus strains to 5 antifungal drugs

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    A. J. Bava

    1989-10-01

    Full Text Available Se estudió la susceptibilidad "in vitro" de 24 cepas de 3 especies del género Cryptococcus a 5 drogas antifúngicas (anfotericina B, 5 fluorocitosina, ketoconazol, itraconazol y miconazol. Las mismas se agruparon según su especie, variedad y origen de aislamiento. Para determinar la concentración inhibitoria mínima (C.I.M. de cada droga se empleó el método de dilución en agar con el medio básico nitrogenado para levaduras, adicionado de glucosa. Se obtuvo además la media geométrica de estos valores para cada grupo y se comparó cada uno de ellos. Los resultados obtenidos fueron homogéneos con la sola excepción de las cepas de Cryptococcus sp (no neoformans, en las cuales se detectaron elevados valores de C.I.M. para la 5 fluorocitosina.A comparative study of the "in vitro" susceptibility of 24 Cryptococcus strains to 5 antifungal drugs (amphotericin B, 5 fluorocytosine, miconazole, itraconazole and ketoconazole, was carried out. These strains were grouped according to species, varieties and isolation's origins. The minimum inhibitory concentration (M.I.C. was determinated by the agar dilution technique in yeast nitrogen base agar with dextrose. The mean geometrical of the M.I.C. values of each group was compared with the others. The results obtained were homogeneous with the only exception of the "non neoformans" strains, in which, higher M.I.C. to 5 fluorocytosine values were detected.

  13. Estudio comparativo de la patogenicidad y la antigenicidad de 6 cepas de Paracoccidioides brasiliensis Comparative study of pathogenicity and antigenicity of six Paracoccidioides brasiliensis strains

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    J.L. Finquelievich

    1993-12-01

    Full Text Available Fueron estudiadas en forma comparativa 6 cepas de P. brasiliensis con el propósito de determinar su patogenicidad para la rata y su antigenicidad. Las mismas fueron aisladas de : 1 biopsia de cuello uterino en 1989 (U, 2 biopsia de mucosa bucal en 1988 (V, 3 aspiración ósea en 1991 (63265, 4 testículo de cobayo 1984(C24, 5 punción-aspiración ganglionaren 1986 (G y 6 cepa proveniente de la Escola Paulista de Medicina (339. Se prepararon antigenos citoplasmáticos liofilizados de cada una de ellas, en la concentración final de 100 mg/ml y se realizaron pruebas de inmunodifusión frente a 6 sueros patrones positivos de ratas. En este ensayo todos los antígenos presentaron dos ó tres bandas de precipitación. Para estudiar el poder patógeno se inocularon, en total, 120 ratas Wistar, de ambos sexos de 200 g de peso, por via intracardíaca con suspensiones de la fase levaduriforme del P. brasiliensis, en concentraciones de 3x10(7 y 5x10(7 células/ml de cada cepa. Los animales que no murieron espontáneamente fueron sacrificados a los 14,28,42, 56 y 70 dias post-infección y se evaluaron los siguientes parámetros: A exámenes macro y microscópicos de pulmones, hígado, bazo y riñones; B cultivos de un pulmón y C prueba de inmunodifusión con antígeno homólogo. Se consideró además, el porcentaje de muertes espontáneas por cada cepa. Los resultados de estos estudios fueron los siguientes:No se observó relación entre la patogenicidad y la antigenicidad. La cepa más virulenta correspondió a un aislamiento reciente a partir de una forma juvenil grave y la más antigénica fue una cepa, morfológicamente atípica, que no provocó lesiones macroscópicas ni microscópicas en los órganos de las ratas.A comparative study of antigenicity and patho-genicity for rats of six Paracoccidioides brasiliensis strains was carried out. The antigenic capacity "in vitro" of cytoplasmic extract from each strain was determined by immuno-diffusion test

  14. Evaluación de la tolerancia a la crioconservación de dos cepas de Escherichia coli K12 de uso frecuente en biotecnología

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    Diliana Celeste Pérez-Reytor*, Angela Estela Sosa Espinosa

    2010-08-01

    Full Text Available Uno de los métodos más recomendados para la conservación de E. coli es la congelación entre -20ºC y -70ºC, donde comúnmente se utiliza glicerol o dimetilsulfóxido como criopreservante. Los bancos de E. coli que se conservan por esta vía pueden mantener altas viabilidades por más de 10 años. A pesar de que es una práctica común están poco documentadas las diferencias que existen entre las cepas de interés biotecnológico en cuanto a la resistencia a la congelación. En este artículo se comparan dos cepas mutantes de E. coli K12: la cepa RRI y la cepa HB101, con el objetivo de evaluar el comportamiento de ambas a dos temperaturas de almacenamiento y diferentes concentraciones de glicerol, después de ocho ciclos sucesivos de congelación-descongelación. Las cepas estudiadas sólo difieren en su capacidad de reparación al daño sobre el ADN al presentar la HB101 una variante mutada del gen recA. Cuando se utilizó una temperatura de almacenamiento de -70 ºC y diferentes concentraciones de criopreservante las cepas tuvieron un comportamiento similar de supervivencia, después de los ocho ciclos. Sin embargo, el comportamiento de la supervivencia difiere cuando la temperatura de congelación en los ciclos es de -20 ºC. Además de la supervivencia y la estabilidad de los marcadores genéticos estudiados, observamos que el efecto de los ciclos de congelación y descongelación retardó el tiempo de aparición de las colonias en medio sólido.

  15. Suscetibilidade da linhagem de células Vero a cepas vacinais do vírus do sarampo Susceptibility of Vero cell line to vaccine strains of the measles virus

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    Célia Sayoko Takata

    1994-06-01

    Full Text Available A suscetibilidade da linhagem de células Vero ao vírus do sarampo é bem conhecida e sua utilização no controle da potência da vacina contra o sarampo é amplamente difundida. Com o objetivo de comparar a suscetibilidade de células Vero empregadas em titulações, amostras provenientes de dois laboratórios controladores (Vero IB e Vero INCQS, foram testadas frente a três cepas vacinais: Moraten, Schwarz e Biken CAM-70. Foram titulados 72 lotes de vacinas contra o sarampo, sendo 25 produzidos com a cepa Moraten, 24 com a cepa Schwarz e 23 com a cepa Biken CAM-70. A análise estatística dos resultados obtidos nas titulações, feita através dos testes Limites para uma Média e "t" de Student, mostrou que para as cepas Moraten e Biken CAM-70, as diferenças de títulos não foram estatisticamente significantes, o mesmo não ocorrendo com a cepa Schwarz, para a qual as células Vero IB se mostraram mais sensíveis.Vero cells used by distinct measles vaccine control laboratories had their susceptibility to Moraten, Schwarz and Biken CAM-70 vaccine strains assayed. Of a total of 72 lots of measles vaccine whose potency was titrated by microtechnique in two Vero cell samples (Vero IB and Vero INCQS, 25 had been produced with Moraten strain, 24 with Schwarz and 23 with Biken CAM-70. The statistical analysis of the results demonstrated that both Vero cells assayed presented comparable susceptibility to Moraten and Biken CAM-70 strains. As to the Schwarz strain, Vero IB cells were more susceptible than the other cell sample tested, thus confirming the existence of different sensitivities of Vero cells to some measles vaccine strains, or even to viruses derived from the same strain but with different passage histories. An altered cell susceptibility to virus replication may significantly alter the results in potency testing. Such alteration may be caused not only by the adoption of distinct protocols for the maintenance of cell cultures by

  16. Production of aflatoxins by Aspergillus flavus and of fumonisins by Fusarium species isolated from Brazilian sorghum Avaliação da toxigenidade das cepas de Aspergillus flavus e Fusarium spp. isoladas de amostras de sorgo

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    Josefa B. da Silva

    2004-09-01

    Full Text Available Fifty-nine Aspergillus flavus and 35 Fusarium verticillioides strains, isolated from freshly harvested (10 and stored (130 Brazilian sorghum samples, were tested regarding their ability to produce aflatoxins (coconut milk agar and fumonisins (rice culture, respectively. Aflatoxins B1 and B2 were detected by TLC, and fumonisins B1 and B2 were analyzed by HPLC. Thirty-eight (64.4% A. flavus strains produced detectable levels of aflatoxins at concentrations ranging from 12.00 to 3282.50 µg/kg (AFB1 + AFB2, while thirty two (91% F. verticillioides strains produced FB1 at concentrations ranging from 0.12 to 5.38 µg/g. Two F. proliferatum strains produced low fumonisin levels. The toxigenic potential of A. flavus (64.4% and F. verticillioides (91.5% strains observed in sorghum samples indicates that rigorous control should be directed at the storage conditions of these products to minimize contamination with toxigenic deteriorating fungi, preventing further hazard to human and animal health.A produção de aflatoxinas por 59 cepas de Aspergillus flavus e fumonisinas por 35 cepas de Fusarium verticillioides isoladas de amostras de grãos de sorgo recém colhido (10 amostras e armazenado (130 amostras, foram avaliadas. A detecção de aflatoxinas (AFB1 e AFB2 foi efetuada por Cromatografia em Camada Delgada (CCD e fumonisinas (FB1 e FB2 foram analisadas por Cromatografia Líquida de Alta Eficiência (CLAE. Os resultados demonstram a produção de AFB1 e AFB2 em 38 cepas (64,4% de A. flavus cujos níveis variaram de 12,00 a 3282,50 µg/kg. Referente às cepas de F. verticillioides, 32 (91% produziram FB1, nas concentrações de 0,12 a 5,38 µg/g. Baixos níveis de fumonisinas foram detectados em 2 cepas de F. proliferatum. A constatação da potencialidade toxígena das cepas de A. flavus (64,4% e de F. verticillioides (91,5% nesta investigação, revelam a importância da pesquisa de aflatoxinas e fumonisinas nas amostras de sorgo. Diante disto

  17. Inhibición in vitro de aislamientos nativos de Trichoderma en presencia de la cepa comercial T22

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    Gabriela Hernández – Ramírez

    2013-06-01

    Full Text Available Título en ingles: In vitro inhibition from native isolates of Trichoderma against commercial strain T22.  Título corto: Inhibición in vitro de aislamientos nativos Resumen El objetivo de este trabajo fue evaluar 14 aislamientos nativos del género Trichoderma (Tn obtenidos de la rizósfera del cultivo de caña de azúcar de acuerdo con su efecto de inhibición In vitro en cultivos duales contra la cepa comercial de Trichoderma harzianum (T22. Los aislamientos nativos con mayor índice de inhibición fueron los denominados Palma (T12 y Hubero (T11, con un valor de 2, mientras que T01, T04, T05 y T08 presentaron un valor de 1. Además, el mayor porcentaje de inhibición fue causado por el aislamiento T03, con una media de 92.32 ± 2.64%, sin diferencias estadísticas con los nativos T07, con un valor inhibición de 88.99 ± 1.46%, T01 87.93 ± 2.28%, y T12; 87.71 ± 3.16. En este caso, los aislamientos T07 y T12 mostraron capacidad inhibitoria con mayores atributos para su selección como agentes de control biológico. Al evaluar la tolerancia In vitro de los aislamientos nativos de Trichoderma a la actividad del agua (aw, se observó efecto significativo sobre el desarrollo micelial de los aislamientos de Trichoderma nativo evaluados. Los aislamientos T03 (7919.3 ± 932.53 y T12 (6388.2 ± 623.40 presentaron el mejor desarrollo radial. Estos resultados sugieren que los aislamientos T03 y T12 podrían desarrollarse mejor bajo condiciones de estrés hídrico. Por lo anterior, concluimos que los aislamientos T07 y T12, son los mejores candidatos como agentes inhibidores y se sugiere evaluarlos In vitro o invernadero contra el agente causal de la enfermedad del muermo rojo en caña de azúcar (Colletotrichum falcatum. Palabras clave: Control Biológico; tolerancia;  ompetencia; estrés hídrico; actividad de agua. Abstract The objective of this work was to evaluate 14 native e Trichoderma genus isolates (Tn obtained from the rhyzosphere of

  18. Isolation and characterization of canine parvovirus type 2c circulating in Uruguay Isolamento e caracterização da cepa tipo 2c do parvovirus canino circulante no Uruguai

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    Andrea Blanc Pintos

    2011-08-01

    Full Text Available This research reports the first CPV-2c isolation in cell culture (canine fibroma cell line A-72 in Uruguay. The isolates were obtained from 13 rectal swabs of Uruguayan dogs with parvovirosis. Samples were submitted to PCR with two sets of primers, restriction fragment length polymorphism (RFLP, partial sequencing of the gene encoding for VP2 capsid protein and phylogenetic characterization. The strain isolated was confirmed as CPV-2c. These results contribute to a better knowledge of CPV strains circulating in Uruguay and promote an evaluation of the efficacy of heterologous vaccines used to protect against the circulating strains.Este trabalho relata o primeiro isolamento do CPV-2c em cultura de células (linhagem celular de fibroma canino A-72, no Uruguai. Os isolados foram obtidos a partir de 13 suabes retais de cães uruguaios com parvovirose. As amostras foram submetidas à reação em cadeia da polimerase (PCR com dois pares de primers, polimorfismo de comprimento de fragmentos de restrição (RFLP, sequenciamento parcial do gene que codifica a proteína capsidial VP2 e caracterização filogenética. A cepa isolada foi confirmada como CPV-2c. Os resultados contribuem para um melhor conhecimento das cepas do CPV circulantes no Uruguai e incitam uma maior investigação sobre a eficácia das vacinas produzidas com cepas heterólogas utilizadas atualmente para proteger contra cepas circulantes.

  19. Sensibilidad a antibióticos, actividad antibacteriana frente a patógenos y fermentaciones ácido lácticas de una cepa nativa de Lactobacillus paracasei de origen humano

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    Fabiana Rey

    2011-05-01

    Full Text Available l objetivo de este trabajo fue caracterizar una cepa nativa de Lactobacillus paracasei aislada en el Departamento de Bioprocesos y Biotecnología del Laboratorio Tecnológico del Uruguay (LATU. Se realizaron fermentaciones ácido lácticas (FAL en leche, a los efectos de determinar las características de crecimiento de la cepa. Se evaluaron tres cinéticas en las FAL: los ácidos orgánicos determinados por titulación en leche, la acidificación del medio a lo largo de las fermentaciones por medidas directas de pH sobre el medio y la biomasa producida en 10 ml de cultivo.Asimismo, se evaluó la actividad antimicrobiana frente a un patógeno gastro intestinal como Salmonella sp. por análisis de discos impregnados con diferentes concentraciones del probiótico. También se determinó la sensibilidad a dicloxacilina y penicilina por medio de un antibiograma modificado. La cepa exhibió buen crecimiento en leche, con curvas de crecimiento típicas de bacterias lácticas. Se detectaron los halos deinhibición del crecimiento de Salmonella sp. dependiendo de la concentración bacteriana. Fueron obtenidas las curvas de inhibicióndel crecimiento bacteriano en función de las concentraciones de antibiótico. En conclusión, esta cepa de Lactobacillus paracasei aislada de materia fecal humana es un prometedor candidato a ser usado en la preparación de productos probióticos.

  20. Estrategia de verificación de calidad de las cepas de Escherichia coli conservadas en la Colección del Centro de Ingeniería Genética y Biotecnología

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    Iveldris Domínguez-Vázquez

    2010-04-01

    Full Text Available La colección de microorganismos de interés biotecnológico del Centro de Ingeniería Genética y Biotecnología incluye diferentes cepas de bacterias y levaduras utilizables en la manipulación de genes mediante el empleo de la ingeniería genética y para la producción de proteínas recombinantes por métodos biotecnológicos. La colección de hospederos de Escherichia coli centraliza todas las cepas que se utilizan en los proyectos de investigación-desarrollo de la institución. Este microorganismo constituye una de las herramientas biológicas imprescindibles para el trabajo en ingeniería genética y la investigación molecular. La fidelidad de los resultados experimentales depende en parte de la calidad de los bancos de estas cepas, que está determinada por las condiciones de almacenamiento y las estrategias de evaluación de los mismos. La complejidad del manejo de esta colección está influida en gran medida por el hecho de que en los medios de propagación pueden crecer un gran número de contaminantes ambientales de difícil identificación. Mientras más similar es el contaminante a la cepa de interés, más difícil es lograr bancos puros con una estabilidad confiable para la conservación. En este trabajo se describe cómo se garantiza el control de calidad de los bancos de Escherichia coli. Los métodos y estrategias de verificación que se describen han sido desarrollados en nuestro laboratorio.

  1. Molecular diversity of Mycobacterium tuberculosis strains in a slum area of Rio de Janeiro, Brazil Diversidade molecular de cepas de Mycobacterium tuberculosis em uma região de favela da cidade do Rio de Janeiro

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    Joycenea Matsuda Mendes

    2008-12-01

    Full Text Available This retrospective molecular study involving restriction fragment length polymorphism, using insertion sequence 6110 as a marker, was conducted in order to provide an initial insight into the genetic diversity of Mycobacterium tuberculosis strains isolated in the slums of the Complexo de Manguinhos, located in the city of Rio de Janeiro, Brazil. Of the 67 strains evaluated, 23 (34.3% were found to belong to clusters (total clusters, 10. Household and social chains of transmission were associated with clustering, in 20% and 60%, respectively. Living in the Conjunto Habitacional Programado 2 slum was associated with clustering. Although not significant, it is relevant that 26% of the clustered strains presented primary resistance. These findings, although possibly underestimating the prevalence due to the failure to analyze all strains, could help improve the local tuberculosis control program.Este estudo retrospectivo envolvendo polimorfismo de fragmento de restrição e utilizando como marcador a seqüência de inserção 6110, foi realizado para fornecer informações iniciais quanto à diversidade genética das cepas de Mycobacterium tuberculosis isoladas em favelas do Complexo de Manguinhos, na cidade do Rio de Janeiro. Das 67 cepas isoladas, 23 (34,3% foram agrupadas em clusters (total de clusters, 10. A transmissão entre comunicantes domiciliares e extra-domicialiares estave associada a 20% e 60% dos clusters, respectivamente. Ser morador do Conjunto Habitacional Programado 2 foi associado à presença de clusters. Embora não significativo, é relevante o fato de que 26% das cepas em cluster apresentaram resistência primária. Estes achados, embora possivelmente subestimados devido à impossibilidade de analisar todas as cepas, fornecem subsídios para a melhoria do programa local de controle da tuberculose.

  2. Diarrea neonatal porcina. Aislamiento de cepas de Escherichia coli toxigénicas productoras de STa, LT y VT Neonatal diarrhoea of piglets. Isolation of toxigenic Escherichia coli strains producing STa, LT, and VT

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    J. ZAMORA

    1999-01-01

    Full Text Available Las cepas toxigénicas de Escherichia coli juegan un importante papel como causa de las enteritis colibacilar porcina, motivo por el cual se investigó la presencia de estos micoorganismos en fecas de cerditos con diarrea. Se aislaron 79 (27.33% cepas de Escherichia coli toxigénicas, 46 (58.2% produjeron STa, 20 (25.3% LT y 13 (16.5% VT, de las cuales 5 sintetizaban VT1, 3 VT2 y 5 expresaron simultáneamente VT1 y VT2. Una cepa que sintetizó simultáneamente VT1 y VT2 perteneció al serotipo O149: K91, K88 y 2 cepas STa+ correspondieron a los serotipos O9: K35 y la otra O149: K91Toxigenic Escherichia coli strains play an important role in the genesis of the enteric colibacillosis of swine., For this reason these mircoorganisms was investigated in faeces of piglets with diarrhoea. A total of 79 (27.3% toxigenic Escherichia coli strains were isolated, of which 46 (58.2% were STa, 20 (25.3% LT and 13 (16.5% VT. Five out of 13 VT strains synthesised VT1, 3 VT2 and 5 expressed VT1 and VT2 simultaneously. One strain that synthesised both VT1 and VT2 belonged to the serotype O149: K91; K88 and 2 strains STa+ corresponded to the serotypes O9: K35. The other one belonged to O149: K91

  3. Validación de un ELISA para la cuantificación de las impurezas proteicas de la cepa hospedera en el principio activo de la vacuna recombinante cubana contra la hepatitis B

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    Eliana Pérez

    2014-04-01

    Full Text Available Se validó un inmunoensayo tipo sandwich de doble anticuerpo para cuantificar las impurezas proteicas de la cepa hospedera que pueden estar presentes en el principio activo de la vacuna cubana contra la hepatitis B. Se prepararon los reactivos biológicos empleados en el ELISA. Las proteínas de la cepa hospedera se obtuvieron bajo las mismas condiciones que el proceso de producción de la proteína recombinante hasta un paso de semipurificación o purificación primaria. Los antisueros dirigidos contra las proteínas de la cepa hospedera se generaron en conejos por un proceso de inmunización en cascada. Para la validación se analizaron los siguientes parámetros: linealidad, límite de detección y cuantificación, exactitud, rango y precisión. El ensayo establecido resultó específico, con una exactitud entre 89% y 109% para todos los tampones estudiados; se demostró un ajuste parabólico y un rango de trabajo entre 0,63 y 1,25 ng/mL, la repetibilidad y la precisión intermedia mostraron coeficientes de variación inferiores al 10 y 20% respectivamente.

  4. The change of behavior of two strains of Leishmania after cultivation in a defined medium Mudanças no comportamento de duas cepas de Leishmania após cultivo em meio definido

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    M. N. Melo

    1987-12-01

    Full Text Available Attempts have been made to characterize two strains of Leishmania that became infective to golden hamsters only after they had been maintained for several years in a chemically defined culture medium. Observations were made on the growth rates of promastigotes in vitro, course of infection in hamsters, morphology of amastigotes, and electrophoretic mobility patterns of eight isoenzymes. Information was obtained about the buoyant densities of n-DNA and k-DNA, and one strain was tested against monoclonal antibodies. The identity of both strains remains obscure.Duas cepas de Leishmania originalmente isoladas in vitro de casos humanos de leishmaniose cutânea e que ab initio não infectaram animais de laboratório, tornaram-se infectantes para hamnsters após serem mantidos por vários anos em meio de cultura quimicamente definido. Foram realizadas observações sobre o crescimento de promastigotas in vitro, curso da infecção em hamsters, morfologia das amastigotas, mobilidade eletroforética de oito enzimas solúveis. Foram obtidas informações sobre a densidade de flutuação do n-DNA e do k-DNA e uma das cepas foi testada contra anticorpos monoclonais. Ambas as cepas permanecem sem identificação precisa.

  5. Effect of aflatoxin B1 on growth and enzymatic activity of a native strain of Bacillus sp Efecto de la aflatoxina B1 sobre el crecimiento y actividad proteolítica de una cepa nativa de Bacillus sp

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    Márquez Edna Judith

    2004-07-01

    Full Text Available The effect of different aflatoxin B1 (AFAB1 concentrations on alkaline protease growth and enzymatic activity was evaluated; a native strain of alkalophilic Bacillus sp cultivated in CSL (Corn Steep Liquor was used. It was found that the effect of AFAB1 on the strain inhibited its growth and enzymatic activity to 1 ppm, showing that the strain is highly sensible to AFAB1, meaning that medium obtained f rom Colombian corn contaminated with this mycotoxin cannot be easily used. Concentrations less than 0.1 ppm did not affect growth and enzymatic activity. Key words: Bacillus, aflatoxin, alkaline proteases.Se evaluó el efecto de diferentes concentraciones de aflatoxina B1 (AFAB1 sobre el crecimiento y actividad enzimática de proteasas alcalinas de una cepa nativa de Bacillus sp Alcalofílico cultivada en LAM (Licor Agotado de Maíz. Se encontró que la cepa inhibe su crecimiento y actividad enzimática a 1 ppm, lo que demuestra una alta sensibilidad de la cepa evaluada a la AFAB1 e imposibilita utilizar fácilmente medios obtenidos de maíz nacional contaminado con esta micotoxina. Las concentraciones inferiores a 0.1 ppm no tienen ningún efecto sobre el crecimiento y la actividad enzimática. Palabras clave: Bacillus, aflatoxina, proteasas alcalinas.

  6. Isolation of Pseudomonas aeruginosa strains from dental office environments and units in Barretos, state of São Paulo, Brazil, and analysis of their susceptibility to antimicrobial drugs Isolamento de cepas de Pseudomonas aeruginosa provenientes do meio ambiente e de equipos dentarios em clinicas dentarias em Barretos, São Paulo, Brasil; analises da susceptibilidade das cepas a drogas antimicrobianas

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    Ana Claudia de Oliveira

    2008-09-01

    Full Text Available A wide variety of opportunistic pathogens has been detected in the tubing supplying water to odontological equipment, in special in the biofilm lining of these tubes. Among these pathogens, Pseudomonas aeruginosa, one of the leading causes of nosocomial infections, is frequently found in water lines supplying dental units. In the present work, 160 samples of water, and 200 fomite samples from forty dental units were collected in the city of Barretos, State of São Paulo, Brazil and evaluated between January and July, 2005. Seventy-six P. aeruginosa strains, isolated from the dental environment (5 strains and water system (71 strains, were tested for susceptibility to six antimicrobial drugs most frequently used against P. aeruginosa infections. Susceptibility to ciprofloxacin, followed by meropenem was the predominant profile. The need for effective means of reducing the microbial burden within dental unit water lines is emphasized, and the risk of exposure and cross-infection in dental practice, in special when caused by opportunistic pathogens like P. aeruginosa, are highlighted.Uma ampla variedade de patógenos oportunistas tem sido detectadas nos tubos de alimentação de água dos equipos odontológicos, particularmente no biofilme formado na superfície do tubo. Entre os patógenos oportunistas encontrados nos tubos de água, Pseudomonas aeruginosa é reconhecida como uma das principais causadoras de infecções nosocomiais. Foram coletadas 160 amostras de água e 200 amostras de fomites em quarenta clinicas odontológicas na cidade de Barretos, São Paulo, Brasil, durante o período de Janeiro a Julho de 2005. Setenta e seis cepas de P. aeruginosa, isoladas a partir dos fomites (5 cepas e das amostras de água (71 cepas, foram analisadas quanto à susceptibilidade à seis drogas antimicrobianas freqüentemente utilizadas para o tratamento de infecções provocadas por P. aeruginosa. As principais suscetibilidades observadas foram para a

  7. Estudio Ultraestructural de Leptospira Biflexa Serovar Andamana cepa JNS al Microscopio Electrónico de Transmisión y Barrido

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    Sonia Macedo A

    2005-10-01

    Full Text Available Objetivos: Investigar la ultraestructura de Leptospira biflexa serovar Andamana cepa JNS, por la técnica de réplica metálica, cortes ultrafinos y tinción negativa al microscopio electrónico de transmisión (MET y barrido (MEB en alta y ultraalta resolución. Materiales y métodos: Cultivos en fase logarítmica 12-15x106 cel/mL del serovar Andamana cepa JNS, aislada de un paciente. Se aplicaron los métodos de tinción negativa, cortes ultrafinos y réplica metálica para la microscopía electrónica de transmisión. Para la microscopía electrónica de barrido se usaron las técnicas en alta y ultraalta resolución de muestras cubiertas con oro y platino. Resultados: Con el método de réplica metálica se definió la estructura externa en células individuales de Leptospira biflexa serovar Andamana al MET. Mediante la técnica de tinción negativa se observó la membrana externa formada por tres capas, los filamentos axiales, la membrana citoplasmática, el citoplasma granular con inclusiones electronodensas, las formaciones «globosas», la «estructura terminal», «apéndices terminales», además de las inclusiones permeables para los electrones, claramente definidas. La morfología clásica del microorganismo fue observada en cortes finos, y al microscopio electrónico de barrido. Conclusiones: Se reporta por primera vez la técnica de réplica metálica para determinar la morfología externa en células individuales de Leptospira biflexa serovar Andamana JNS, la cual ofrece resultados ventajosos en comparación con otros métodos. La ultraestructura, y las inclusiones permeables para electrones dentro del citoplasma a una magnificación de 120000x 20KV fueron nítidamente observadas por tinción negativa. La estructura helicoidal del microorganismo se comprobó al MEB.

  8. Cepas invasivas de pneumococo isoladas de crianças e adolescentes em Salvador Invasive pneumococcal strains isolated from children and adolescents in Salvador

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    Cristiana M. Nascimento-Carvalho

    2003-06-01

    Full Text Available OBJETIVOS: descrever resistência antimicrobiana e sorotipos de cepas de pneumococo. MÉTODOS: durante 57 meses, foi conduzida uma vigilância de cepas invasivas de pneumococo de pacientes com idade OBJECTIVE: describe the antimicrobial resistance and serotype distribution of pneumococcal strains. METHODS: in a 57-month period, a laboratory-based surveillance of invasive pneumococcal strains from patients aged < 20 years was conducted. Pneumococcus was identified by means of tests for solubility in bile and optochin. Pneumococcal resistance to penicillin was screened by 1µg oxacillin disc and minimal inhibitory concentration was determined for the strains not susceptible to penicillin. Disc diffusion and broth microdilution methods were used for surveillance of resistance to other antimicrobials. Pneumococci were serotyped by means of the Neufeld-Quellung reactions. RESULTS: of 70 patients, 57.1% were males. The mean age was 1.92 yrs (mean 3.19 + 3.66 yrs, range 1 month to 19.5 yrs; 52.9% and 81.4% were < 2 yrs and < 5 yrs, respectively. The strains were isolated from blood (91.4%, CSF (2.9%, pleural (2.9%, peritoneal (1.4% and abscess (1.4% fluids from patients with pneumonia (77.1%, fever without localizing signs (10.0%, meningitis (4.3%, others (8.6%. Resistance was detected to penicillin (20.0%, trimethoprim-sulfamethoxazole (65.7%, tetracycline (21.4%, ofloxacin (6.3%, erythromycin (5.7%, clindamycin (2.9%. All tested strains were susceptible to chloramphenicol and vancomycin. Among penicillin-resistant strains, high resistance was detected in one, the same that showed intermediate resistance to cefotaxime. The most frequent serotypes were: 14 (22.9%, 5 and 6A (10.0% each, 6B and 19F (8.6% each, 9V, 18C and 23F (5.7% each. Resistance to penicillin was detected in serotypes 14 (71.4%, 6B and 19F (14.3% each. CONCLUSIONS: of 70 strains, 67.2% were classified as serotypes included in the heptavalent conjugate pneumococcal vaccine as well as

  9. Clonado de cepas de Tritrichomonas foetus obtenidas de infecciones naturales en bovinos Cloned strains of Tritrichomonas foetus obtained from natural infections in cattle

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    M.L. Doumecq

    2011-12-01

    Full Text Available El objetivo del presente trabajo es describir una técnica sencilla para clonar cepas de Tritrichomonas foetus en un medio sólido. A partir de diferentes cepas obtenidas de infecciones naturales de bovinos se ensayaron dos técnicas: Homogeneizado en tubo y Homogeneizado en placa. Para cada una de ellas se evaluaron diferentes concentraciones de agar en el medio de cultivo y el tiempo de incubación más apropiado. Los resultados obtenidos demostraron que la técnica más adecuada fue la técnica de Homogeneizado en placa, con una concentración de agar 0,45 g % p/v y un tiempo de incubación de 5 días en anaerobiosis. Esta técnica resulta un procedimiento útil y sencillo para la obtención de clones de T. foetus ya que permite el crecimiento de protozoarios en colonias aisladas sobre un medio sólido. Además la técnica puede ser utilizada para evaluar la producción de colonias hemolíticas por la presencia de glóbulos rojos en el medio de cultivo.The aim of this work is to describe a simple technique to cloned strain of Tritrichomonas foetus in a solid medium. From different strains from natural infections in cattle two techniques: Homogenized in tube and Homogenized in plate were tested. The must appropriate agar concentrations in the culture medium and incubation time were evaluated for each techniques. The results showed that the most appropriate technique was Homogenized in plate with an agar concentration of 0.45 g% w /v and an incubation time of 5 days. This technique is a useful and easy to obtain clones of T. foetus, allows the growth of protozoa in isolated colonies on solid media. Furthermore the technique can be used to evaluate the production of hemolytic colonies for the presence of bovine red blood cells in the culture medium.

  10. Vegetal waste degradation by microbial strains inoculation Degradación de residuos vegetales mediante inoculación con cepas microbianas

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    Nubia Grijalva Vallejos

    2013-06-01

    degradadores demateriales lignocelulósicos por su capacidad de sintetizar enzimas extracelulares hidrolíticas yoxidativas en altas cantidades. Trichoderma reesei, Aspergillus niger, Penicillium sp. yPhanerochaete chrysosporium son cepas modelo cuya eficiencia de degradación de materialesricos en lignocelulosa incluso en presencia de contaminantes ha sido comprobada. Se estánrealizando varios estudios de mutagénesis dirigida, co-cultivo y expresión heteróloga, con elobjeto de mejorar el contenido de enzimas (celulasas, xylanasas, y β-glucosidasas en variascepas, además de nuevas búsquedas genéticas para encontrar otros microorganismos coneste potencial. Su principal aplicación es la producción industrial de etanol y metabolitossecundarios bajo condiciones controladas en procesos de fermentación. Esta revisiónproporciona una perspectiva general de las estrategias y metodologías actualmente usadaspara el aprovechamiento de residuos vegetales mediante inoculación de cepas microbianas.

  11. Evaluación de una formulación para la conservación de cepas de Pseudomona aeruginosa

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    Nancy Burguet-Lago

    2014-01-01

    Full Text Available La humanidad tiene la responsabilidad histórica de solucionar uno de los problemas más importantes de los tiempos actuales: la conservación del medio ambiente. Mientras que la conservación de plantas y animales ha sido aceptada desde hace tiempo, solo recientemente es que ha sido recibido reconocida la necesidad de conservar la diversidad microbiana. Laboratorios LIORAD dispone de una colección de cultivos microbianos procedente de subcultivos primarios de cepas de referencia, donde se encontraba depositada Pseudomonas aeruginosa, conservada por liofilización mediante dos variantes de sustancias lioprotectoras: leche descremada y glicerol al 20 %. Teniendo en cuenta que en la actualidad está más extendido el empleo de mezclas de aditivos, en el presente estudio se propuso como objetivo evaluar una formulación (variante 3 constituida por leche descremada más peptona al 5 %, la cual se seleccionó (a partir de estudios previos publicados por otros autores. Para verificar la conservación del cultivo se realizó un adecuado control de calidad, que incluyó la comprobación de pureza, viabilidad y estabilidad de las propiedades de interés (identificación fisiológica y bioquímica. Se procedió a realizar un tratamiento estadístico mediante el software Minitab, V 14.0, para determinar si existían diferencias significativas entre las diferentes variantes de sustancias lioprotectoras empleadas. La pureza e identidad, se mantuvieron inalterables en las tres variantes, la viabilidad: tanto en la variante 1, como en la 3 han permitido una buena supervivencia durante el tiempo objeto de estudio; no así al emplear glicerol al 20 %. El estudio estadístico corroboró con un 95 % de confiabilidad que no había diferencias estadísticas entre las variantes 1 y 3. Al finalizar el estudio se dispuso de dos variantes para la conservación de la cepa por largos periodos de tiempo (el empleo de la leche descremada al 20 % y la formulación objeto de

  12. Cepas de Campylobacter jejuni resistentes a quinolonas aisladas de humanos, gallinas y pollos Quinolone resistant Campylobacter jejuni strains isolated from humans and from poultry

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    Rodolfo Notario

    2011-08-01

    Full Text Available Se compararon 8 aislamientos de Campylobacter jejuni provenientes de humanos con enfermedad diarreica aguda, con 23 aislamientos de cloaca de gallinas y pollos obtenidos de zonas próximas a la ciudad de Rosario, todos resistentes a la ciprofloxacina. Las muestras se sembraron en agar selectivo y se incubaron en microaerofilia a 42 °C. Las colonias se identificaron con el método tradicional. Los aislamientos se conservaron a -70 °C en caldo cerebro corazón con 17% v/v de glicerina. La clonalidad se determinó por RAPD-PCR, utilizando el primer 1254 (Stern NJ. Se interpretaron los aislamientos como clones distintos cuando diferían en una banda de amplificación. Se obtuvieron 5 clones diferentes. Los patrones I, II y V fueron aislados en criaderos industriales de pollos y en humanos (el II también en un establecimiento de gallinas ponedoras de huevos. En un gallinero familiar se obtuvo el patrón I. El patrón III sólo se obtuvo de humanos. El patrón IV se halló en uno de los criaderos pero no en humanos. Se pudo determinar que 93.5% de las cepas se aislaron tanto de animales como de humanos, por lo que se considera posible que la colonización de criaderos con cepas resistentes a los antimicrobianos pudiera ser el origen de la infección de humanos.Eight quinolone resistant Campylobacter jejuni strains isolated from humans with diarrheal disease were compared with 23 isolates from chicken and from laying hens. Samples were cultured on selective agar in microaerophilia, identified by conventional tests, and conserved in 17% glycerol at -70 °C. Clones were determined by RAPD-PCR employing the 1254 primer (Stern NJ. Five patterns were obtained. Patterns I, II, and V were found in both poultry and human isolates. Pattern I was obtained from poultry in a domestic henhouse. Pattern III was only obtained from humans whereas pattern IV was only obtained from poultry. A 95.3% of clones were found in both, humans and poultry. According to these

  13. Biological parameters of two strains (acaricide resistant and susceptible of the tick Rhipicephalus microplusParâmetros biológicos de duas cepas (sensível e resistente a acaricidas do carrapato Rhipicephalus microplus

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    Luciana Dalla Rosa

    2013-10-01

    Full Text Available The resistance of Rhipicephalus microplus to acaricides occurs in almost all regions where it is present and treatments with chemicals are the most frequent. Therefore the monitoring of ticks is crucial to diagnose resistance at an early stage to help slow down the spread of resistance and to obtain knowledge of the distribution of acaricide resistance. The objective of the present work was to know the biological parameters of R. microplus sensitive strain to the main acaricides used. We compared the number and weight of engorged females, as well as the mass of eggs obtained the percentage of hatching and reproductive efficiency of two strains (acaricide-resistant and susceptible of the tick R. microplus, after passage in cattle. The results showed a reduced capacity to adjust the acaricide-susceptible strain, which presented the lowest number of ticks recovered (p?0.0001, with less weight and egg mass. With respect to reproductive parameters, the ticks susceptible strain showed hatching rate eggs (p=0.0002410 and reproductive efficiency reduced when compared with those of the acaricide-resistant strain. A resistência do Rhipicephalus microplus aos carrapaticidas ocorre em quase todas as regiões onde ele está presente e os tratamentos com produtos químicos são os mais frequentes. Portanto, monitoramento de carrapatos é fundamental para diagnosticar a resistência em um estágio inicial, diminuir a propagação e obter conhecimento da distribuição da resistência acaricida. Com o objetivo de se conhecer os parâmetros biológicos de uma cepa sensível de R. microplus aos principais carrapaticidas utilizados, o presente trabalho foi desenvolvido. Foram comparados o número e o peso de teleóginas, assim como a massa de ovos obtida, a percentagem de eclosão e a eficiência reprodutiva de duas cepas (sensível e resistente a acaricidas do carrapato R. microplus, após passagem em bovinos. Os resultados demonstraram uma menor capacidade de

  14. Serosubtipos de meningococo B causantes de enfermedad invasiva en Cantabria y concordancia con la cepa de la vacuna cubana Meningococcus B serosubtypes causing invasive disease in Cantabria [Spain] and agreement with the Cuban vaccine strain

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    Álvaro González de Aledo

    2004-02-01

    Full Text Available Objetivo: Conocer los serosubtipos de meningococo B causantes de enfermedad invasiva en Cantabria y el porcentaje de concordancia con la cepa de la vacuna cubana VA-Mengoc-BC. Métodos: Revisión retrospectiva de todos los casos de enfermedad invasiva por meningococo B declarados a través del sistema de Enfermedades de Declaración Obligatoria (EDO entre el 1 de enero de 1998 y el 28 de febrero de 2003, los aislamientos bacteriológicos del Hospital Universitario Marqués de Valdecilla y la serosubtipificación hecha en el laboratorio de referencia de Majadahonda. Resultados: De los 117 casos declarados, se identificó el serosubtipo de 79 (67,5%. La coincidencia con la cepa vacunal cubana fue del 67, el 71 y el 76% en los grupos de edad de 0 a 19 años, 18 meses a 19 años, y de 4 a 19 años, respectivamente. Incluyendo las cepas con protección cruzada, estos porcentajes se elevan al 83, el 83 y el 84%, respectivamente, en los mismos grupos de edad. Conclusiones: El porcentaje de coincidencia con la cepa vacunal cubana y con las cepas heterólogas con protección cruzada es alto, por lo que esta vacuna podría ser de utilidad para la situación epidemiológica de Cantabria.Objective: To determine the serosubtypes of meningococcus B causing invasive disease in Cantabria and the percentage of agreement with the Cuban vaccine strain, VA-MENGOC-BC. Methods: We performed a retrospective review of all cases of invasive disease due to meningococcus B declared through the Diseases of Mandatory Reporting System between 1st January 1998 and 28th February 2003. The bacteriological isolates of the «Marqués de Valdecilla» University Hospital, and the serosubtyping performed in the Majadahonda reference laboratory (Madrid, Spain were also analyzed. Results: Of the 117 declared cases, serosubtype was identified in 79 (67.5%. The agreement with the Cuban vaccine strain was 67%, 71% and 76% in the age groups of newborn to 19 years, 18 months to 19 years

  15. Rebrota de cepas de Acacia mearnsii em diferentes idades, épocas do ano e alturas de corte Resprouting of Acacia mearnsii stumps under different ages, seasons and cut heights

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    Edison Rogério Perrando

    2006-04-01

    Full Text Available O objetivo deste trabalho foi avaliar o efeito da idade, da época do ano e da altura de corte sobre a capacidade de rebrota de cepas de Acacia mearnsii De Wild. O trabalho foi conduzido em delineamento de blocos ao acaso e parcelas subdivididas no tempo. Em árvores de quatro e sete anos, foram avaliadas as alturas de corte de 0,15; 0,30; 0,45; 0,60; 1,2 e 2 m aos 15, 30, 45, 60, 75 e 90 dias depois do corte, nas quatro estações do ano. Obteve-se interação significativa entre a altura de corte e a época de avaliação, em ambas as idades avaliadas. As maiores médias, quanto ao número de brotações por cepa, foram constatadas a 1,2 e 2 m de altura, na idade de quatro anos. Elevados porcentuais de mortalidade foram registrados em cepas com sete anos, independentemente da altura de corte. A capacidade de rebrota em cepas de acácia-negra é estimulada, quando o corte é realizado no período entre o outono e a primavera. O verão é a estação menos adequada à rebrota de cepas dessa espécie.The objective of this work was to evaluate the effect of age, time of the year and cut height on the resprouting capacity of Acacia mearnsii De Wild. stumps. The work was conducted in stands of four and seven years of age, in randomized blocks design and time subdivided plots. Different cut heights (0.15; 0.30; 0.45; 0.60; 1.2 and 2 m, and evaluation times (15, 30, 45, 60, 75 and 90 days after cutting, in the four seasons of the year were evaluated. A significant interaction between cut height and evaluation time was found in both ages. The higher averages due to stumps in each strain were verified in 1.2 and 2 m height, in the age of four years. High death percentages were registered in seven years-old stumps, independently of cut height. The resprouting capacity of black wattle stumps is stimulated when cut is conducted between autumn and spring; summer is the least suitable season to stumps resprouting of this specie.

  16. EVALUACIÓN in vitro DEL EFECTO BACTERICIDA DE CEPAS NATIVAS DE Lactobacillus sp. CONTRA Salmonella sp. y Escherichia coli In vitro EVALUATION OF THE BACTERICIDAL EFFECT OF NATIVE STOCKS OF Lactobacillus sp. AGAINST Salmonela sp. AND Echerichia coli

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    Ana Cristina Estrada Maldonado

    2005-06-01

    Full Text Available En esta investigación se trabajó con dos cepas nativas de Lactobacillus plantarum y Lactobacillus brevis, aisladas de productos fermentados; estas crecen en medios de cultivo y producen un extracto complejo de ácidos orgánicos y péptidos con actividad bactericida. Los extractos de estas cepas mostraron capacidad bactericida frente a Salmonella sp. y Escherichia coli. Los ensayos para determinar su acción se realizaron con el extracto crudo y centrifugado provenientes de cada una de las cepas, a diferentes tiempos de almacenamiento, temperatura y pH. Se observó una mejor actividad antibacteriana y estabilidad de la actividad, en el extracto crudo almacenado a temperatura de 0ºC y 4ºC. A pH 5.5 se presento la mejor actividad en los dos extractos frente a las cepas de estudio. Se concluyó que los extractos sintetizados por ambas cepas tienen un alto potencial bactericida contra estas dos patógenos que son responsables de toxi-infecciones alimentarias.In this investigation, two native stocks of Lactobacillus plantarum and Lactobacillus brevis isolated from fermented products were studied; these grow in culture media and produce a complex extract of organic acids and peptides with bactericidal activity. The extracts of these stocks showed bactericidal capacity with Salmonella sp. and Escherichia coli. The tests to determine their action were made with crude and centrifuged extract originating of each one of the stocks, with different storage times, temperatures and pHs. A superior antibacterial activity and stability of the activity was observed in the crude extract stored in temperatures of 0ºC and 4ºC. With pH 5,5 the best activity of the two extracts against the study stocks was obtained. It is concluded that the extracts synthesized by both stocks have a high bactericidal potential against these two pathogens that are responsible for nutritional toxi-infections.

  17. Leptospirosis en el Perú: II. Incidencia de la infección en las ratas (Rattus norvegicus de la ciudad de Lima e identificación de la cepa infectante

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    Arístides Herrer

    1960-01-01

    Full Text Available Entre mayo de 1955 y diciembre de 1957 se ha estudiado la incidencia de la leptospirosis en las ratas (Rattus norvegicus que infestan los mercados de abastos en la ciudad de Lima, tratando al mismo tiempo de determinar el valor diagnóstico de cada uno de los métodos empleados. En tales estudios se utilizaron 600 ratas, en la mayoría de las cuales se efectuaron hemocultivos, cultivos del riñón, reacciones serológicas de aglutinación-lisis y observaciones al campo oscuro del triturado de riñón, Al determinar la presencia de anticuerpos en la sangre de las ratas así como en la identificación de las cepas que se aislaran en cultivo, se emplearon las siguientes cepas serológicas de leptospiras: L. icterohaemorrhagiae AB Wijnberg, L. canicola Ruebush, L. autumnalis AB Akiyama A., L. bataviae Van Tienen, L. sejroe Mallersdorf, L. pomona S91, L. ballum S102, L. hyos, L. grippotyphosa Moscow V., L. hebdomadis y L. pyrogenes Salinem. Además, con frecuencia se usó también dos cepas (R23 y R410 aisladas por los autores durante las investigaciones e identificadas como L. icterohaemorrhagiae. Los principales resultados obtenidos son los siguientes: 1. Los hemocultivos fueron positivos en el 1.2%, entretanto que los cultivos del riñón ofrecieron una positividad de 49.0%, variando entre 38.3 y 54.5% de acuerdo con los diferentes mercados donde fueran capturadas las ratas. La observación al campo oscuro del triturado del riñón fue positiva en el 26. 0% de los casos. De acuerdo con la reacción de aglutinación-lisis, los sueros fueron positivos en el 32.8%. En 591 ratas, en las que se realizaran los estudios empleando los cuatro métodos de diagnóstico mencionados, la positividad fue de 62.4%. 2. La reacción de aglutinación-lisis fue positiva en 195 sueros, 167 (85.6% de los cuales reaccionaron únicamente con el antígeno de L. icterohaemorrhagiae AB Wijnberg; seis sueros también reaccionaron tan sólo con un antígeno, pero diferente al

  18. Evaluation of Trichoderma spp. and Clonostachys spp. Strains to Control Fusarium circinatum in Pinus radiata Seedlings Evaluación de Cepas de Trichoderma spp. y Clonostachys spp. para Controlar Fusarium circinatum en Plántulas de Pinus radiata

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    Priscila Moraga-Suazo

    2011-09-01

    os. Debido a la ausencia de métodos eficientes para controlar este patógeno, el propósito de este estudio fue evaluar el potencial uso de cepas de Trichoderma y Clonostachys como control de F. circinatum en plántulas de Pinus radiata D. Don. Ochenta y un cepas de Trichoderma spp. y Clonostachys spp. fueron evaluadas a través de ensayos in vitro para determinar su habilidad para actuar como antagonistas de F. circinatum y 21 cepas fueron probadas por su habilidad para reducir la mortalidad post-emergencia e incrementar la supervivencia de P. radiata bajo condiciones de invernadero. Durante los experimentos in vitro, 15 cepas de Trichoderma inhibieron el crecimiento del patógeno más de un 60% y una cepa de Clonostachys mostró parasitismo de hifas de F. circinatum. En experimentos en invernadero, los antagonistas no controlaron la enfermedad cuando fueron agregados después de la inoculación del patógeno. Sin embargo, cuando los antagonistas fueron sembrados antes del patógeno, cuatro cepas (Clonostachys UDC-32 y UDC-222, Trichoderma UDC-23 y UDC-408 redujeron la mortalidad post-emergencia entre 80 y 100%. Entre estas cepas, sólo Clonostachys UDC-222 incrementó significativamente la supervivencia de plántulas de P. radiata. Estos resultados demuestran que Clonostachys UDC-222 posee gran potencial para ser empleado como agente de biocontrol contra F. circinatum en la producción de plantas de P. radiata.

  19. Nodulação e produtividade de Vigna unguiculata (L. Walp. por cepas de rizóbio em Bom Jesus, PI Yield and nodulation of Vigna unguiculata (L. Walp. inoculated with rhizobia strains in Bom Jesus, PI

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    Elaine Martins Costa

    2011-03-01

    Full Text Available Objetivou-se avaliar a resposta de Vigna unguiculata (L. Walp. cv. "BR 17 Gurguéia" à inoculação com duas cepas isoladas de solos de mineração de bauxita em reabilitação: UFLA 3-164 e UFLA 3-155 e três cepas INPA 03 11B (BR 3301; UFLA 03 84 (BR 3302 e BR 3267 (SEMIA 6462, autorizadas pelo MAPA como inoculantes para a cultura do feijão-caupi. O experimento foi conduzido em campo na Universidade Federal do Piauí, Campus Professora Cinobelina Elvas, Bom Jesus, PI. Utilizou-se o delineamento experimental em blocos casualizados com sete tratamentos e com seis repetições, sendo cinco cepas citadas e dois controles não inoculados, um com N-mineral (70 kg ha-1 de N e outra sem N mineral. Foram avaliados a nodulação (número e massa seca de nódulos, o crescimento (massa seca da parte aérea, o rendimento de grãos e o teor e acúmulo de nitrogênio na parte aérea e nos grãos, além da eficiência relativa. A inoculação das sementes com as cepas de bactérias diazotróficas simbióticas resultou em rendimentos de grãos equivalente à testemunha adubada com nitrogênio mineral. A cepa em fase de teste, UFLA 3-155 apresentou rendimento de grãos igual à cepa recomendada INPA 03 11B (BR 3301, podendo também ser testada em outras regiões brasileiras. Entre as cepas aprovadas pelo MAPA a INPA 03 11B (BR 3301 apresentou a maior produção de grãos.It evaluates the effect of inoculation with two rhizobia strains isolated from soils under rehabilitation after bauxite mining: UFLA 3-164 and UFLA 3-155, compared to inoculation with strains INPA 03 11B (BR 3301; UFLA 03 84 (BR 3302 and BR 3267 (SEMIA 6462, officially authorized as inoculant to cowpea by MAPA, in Vigna unguiculata (L. Walp cv. "BR 17 Gurgueia". The experiment was carried out at the 'Universidade Federal do Piauí, Campus Professora Cinobelina Elvas, Bom Jesus, PI,' in a randomized block design, white seven treatments and six replications. Treatments were the five strains and

  20. Characterization of a 65 kDa NIF in the nuclear matrix of the monocot Allium cepa that interacts with nuclear spectrin-like proteins.

    Science.gov (United States)

    Pérez-Munive, Clara; Blumenthal, Sonal S D; de la Espina, Susana Moreno Díaz

    2012-01-01

    Plant cells have a well organized nucleus and nuclear matrix, but lack orthologues of the main structural components of the metazoan nuclear matrix. Although data is limited, most plant nuclear structural proteins are coiled-coil proteins, such as the NIFs (nuclear intermediate filaments) in Pisum sativum that cross-react with anti-intermediate filament and anti-lamin antibodies, form filaments 6-12 nm in diameter in vitro, and may play the role of lamins. We have investigated the conservation and features of NIFs in a monocot species, Allium cepa, and compared them with onion lamin-like proteins. Polyclonal antisera against the pea 65 kDa NIF were used in 1D and 2D Western blots, ICM (imunofluorescence confocal microscopy) and IEM (immunoelectron microscopy). Their presence in the nuclear matrix was analysed by differential extraction of nuclei, and their association with structural spectrin-like proteins by co-immunoprecipitation and co-localization in ICM. NIF is a conserved structural component of the nucleus and its matrix in monocots with Mr and pI values similar to those of pea 65 kDa NIF, which localized to the nuclear envelope, perichromatin domains and foci, and to the nuclear matrix, interacting directly with structural nuclear spectrin-like proteins. Its similarities with some of the proteins described as onion lamin-like proteins suggest that they are highly related or perhaps the same proteins.

  1. Degradación microbiana de cianuro procedente de plantas de beneficio de oro mediante una cepa nativa de P. fluorecens

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    OSCAR JAIME RESTREPO

    2006-01-01

    Full Text Available El cianuro es el compuesto lixiviante más utilizado en la industria metalúrgica de metales preciosos. El cianuro presenta efectos nocivos, entre los que se destacan su alta toxicidad y su efecto inhibitorio en la respiración celular. En este trabajo se probó la alternativa biotecnológica de degradar cianuro empleando una cepa nativa de P. fluorescens, aislada a partir de muestras de arenas procedentes de plantas de beneficio de oro que utilizan la cianuración ubicadas en municipio de Segovia, Colombia. En la mayor parte de las plantas de tratamiento no se controlan técnicamente los procesos, lo cual lleva a la utilización de cantidades de NaCN por encima de las necesarias, generando altas descargas del exceso tanto en solución como en las arenas descartadas. Las pruebas de toxicidad realizadas con D. pulex indican que una concentración de cianuro mayor o igual a 54 ppm es suficiente para intoxicar e inhibir su sobrevivencia. Los tratamientos convencionales para degradación de cianuro, suelen ser muy comunes y eficientes, sin embargo presentan desventajas por el alto costo que conlleva la compra de los reactivos necesarios. El tratamiento microbiano por su parte, demuestra eliminar grandes cantidades de cianuro de una manera eficiente y económica.

  2. Bronquite infecciosa das galinhas: conhecimentos atuais, cepas e vacinas no Brasil Infectious bronchitis of chickens: current knowledge, strains and vaccines in Brazil

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    Juliana Figueiredo Pitangui Mendonça

    2009-11-01

    Full Text Available A bronquite infecciosa das galinhas (IB é uma doença viral aguda e altamente contagiosa que provoca grandes perdas econômicas à indústria avícola em todo o mundo. Considerando que surtos têm ocorrido no Brasil com emergência de novas variantes de IBV, desafiando as estratégias de vacinação atuais, este trabalho objetiva revisar os conhecimentos sobre IB e IBV, a sua distribuição, as cepas e as vacinas utilizadas no Brasil.Infectious bronchitis (IB is an acute, highly contagious disease of chickens, caused by infectious bronchitis virus (IBV, which results in great economic losses to the poultry industry worldwide, despite the routine use of vaccines. Several outbreaks do occur periodically in densely populated poultry regions in Brazil and there are constant emergence of new variants. The aim of this paper is to review the current knowledge about IBV and IB, the distribution, strains and vaccines in Brazil.

  3. Effects of Lead on the Morphology and Structure of the Nucleolus in the Root Tip Meristematic Cells of Allium cepa L.

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    Ze Jiang

    2014-07-01

    Full Text Available To study the toxic mechanisms of lead (Pb in plants, the effects of Pb on the morphology and structure of the nucleolus in root tip meristematic cells of Allium cepa var. agrogarum L. were investigated. Fluorescence labeling, silver-stained indirect immunofluorescent microscopy and western blotting were used. Fluorescence labeling showed that Pb ions were localized in the meristematic cells and the uptake and accumulation of Pb increased with treatment time. At low concentrations of Pb (1–10 μM there were persistent nucleoli in some cells during mitosis, and at high concentration (100 μM many of the nucleolar organizing regions were localized on sticky chromosomes in metaphase and anaphase cells. Pb induced the release of particles containing argyrophilic proteins to be released from the nucleus into the cytoplasm. These proteins contained nucleophosmin and nucleolin. Pb also caused the extrusion of fibrillarin from the nucleus into the cytoplasm. Western blotting demonstrated the increased expression of these three major nucleolar proteins under Pb stress.

  4. Effects of lead on the morphology and structure of the nucleolus in the root tip meristematic cells of Allium cepa L.

    Science.gov (United States)

    Jiang, Ze; Zhang, Huaning; Qin, Rong; Zou, Jinhua; Wang, Junran; Shi, Qiuyue; Jiang, Wusheng; Liu, Donghua

    2014-07-31

    To study the toxic mechanisms of lead (Pb) in plants, the effects of Pb on the morphology and structure of the nucleolus in root tip meristematic cells of Allium cepa var. agrogarum L. were investigated. Fluorescence labeling, silver-stained indirect immunofluorescent microscopy and western blotting were used. Fluorescence labeling showed that Pb ions were localized in the meristematic cells and the uptake and accumulation of Pb increased with treatment time. At low concentrations of Pb (1-10 μM) there were persistent nucleoli in some cells during mitosis, and at high concentration (100 μM) many of the nucleolar organizing regions were localized on sticky chromosomes in metaphase and anaphase cells. Pb induced the release of particles containing argyrophilic proteins to be released from the nucleus into the cytoplasm. These proteins contained nucleophosmin and nucleolin. Pb also caused the extrusion of fibrillarin from the nucleus into the cytoplasm. Western blotting demonstrated the increased expression of these three major nucleolar proteins under Pb stress.

  5. Vermistabilization of sugar beet (Beta vulgaris L) waste produced from sugar factory using earthworm Eisenia fetida: Genotoxic assessment by Allium cepa test.

    Science.gov (United States)

    Bhat, Sartaj Ahmad; Singh, Jaswinder; Vig, Adarsh Pal

    2015-08-01

    In the present study, sugar beet mud (SBM) and pulp (SBP) produced as a waste by-products of the sugar industry were mixed with cattle dung (CD) at different ratios on dry weight basis for vermicomposting with Eisenia fetida. Minimum mortality and highest population of worms were observed in 20:80 (SBM20) mixture of SBM and 10:90 (SBP10) ratios. However, increased percentages of wastes significantly affected the growth and fecundity of worms. Nutrients like nitrogen, phosphorus, sodium, increased from initial feed mixture to final products (i.e., vermicompost), while organic carbon (OC), C:N ratio and electrical conductivity (EC) declined in all the products of vermicomposting. Although there was an increase in the contents of all the heavy metals except copper, chromium, and iron in SBM, the contents were less than the international standards for compost which indicates that the vermicompost can be used in the fields without any ill effects on the soil. Allium cepa root chromosomal aberration assay was used to evaluate the genotoxicity of pre- and post-vermicomposted SBM to understand the effect of vermicomposting on the reduction of toxicity. Genotoxicity analysis of post-vermicomposted samples of SBM revealed 18-75% decline in the aberration frequencies. Scanning electron microscopy (SEM) was recorded to identify the changes in texture in the control and vermicomposted samples. The vermicomposted mixtures in the presence of earthworms confirm more numerous surface irregularities that prove to be good manure. PMID:25794577

  6. Estudios sobre leishmaniasis tegumentaria en el Perú. I. Infección experimental de perros con cepas de leishmanias procedentes de casos de Uta

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    Arístides Herrer

    1951-01-01

    Full Text Available Se han inoculado varias series de perros con cepas de leishmanias procedentes de la forma clínica de la leishmaniasis tegumentaria conocida en el Perú con el nombre de uta, usando con tal objeto material tomado directamente de las lesiones utosas así como también cultivos del parásito. Los principales resultados obtenidos en tales inoculaciones son los siguientes: 1. Ha sido imposible infectar al perro con cultivos mantenidos solamente in vitro por espacio de cinco a ocho años, no obstante de haberse ensayado en tres series distintas de inoculaciones. 2. Se ha conseguido infecciones experimentales en el 87 por ciento de los perros que fueron inoculados con cultivos de reciente aislamiento. Aunque las inoculaciones fueran hechas bajo las mismas circunstancias en el dorso del hocico y la cara interna de una de las orejas, la infección se ha obtenido principalmente en el hocico. 3. También se ha logrado infectar perros inoculándoles material tomado directamente de las lesiones leishmaniásicas, ya sea de casos de uta o de lesiones producidas experimentalmente en otros perros.

  7. Estudo fitoquímico e avaliação in vitro da atividade anti-Trypanosoma cruzi cepa Y de Pilocarpus spicatus St. Hil. (Rutaceae

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    C.V Silva

    2014-12-01

    Full Text Available A investigação química da espécie Pilocarpus spicatus, popularmente conhecida como jaborandi e usada na medicina tradicional para doenças como estomatite, febre, bronquite e psoríase, teve por objetivo o isolamento e/ou identificação de substâncias ativas e a avaliação da atividade antiparasitária dos extratos frente às formas epimastigotas de Trypanosoma cruzi. O estudo resultou na identificação de nove substâncias, tais como: tridecanona, 2-heptadecanona, espatulenol, aromadendreno, β-cariofileno, ácido 3α-hidroxitirucala-7,24-dien-21-óico, (+-isoangenomalina, episesamina e sesamina. As estr uturas dos compostos foram elucidadas por análises espectroscópicas e comparação com dados da literatura. Os extratos hexânico e metanólico de folhas e raízes foram testados in vitro contra o Trypanosoma cruzi cepa Y e apresentaram atividade tripanomicida.

  8. Detección por cromatografía de capa fina (CCF de metabolitos antinfúngicos producidos de Pseudomonas aeruginosa cepa PSS

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    Magdalena Lorenzo

    2006-01-01

    Full Text Available Se muestran los resultados preliminares obtenidos de la detección de extractos orgánicos de metabolitos antifúngicos de Pseudomonas aeruginosa cepa PSS por cromatografía de capa fina (CCF. Las extracciones fueron llevadas a cabo con acetato de etilo y la fase orgánica se analizó por TLC empleando el sistema de solvente cloroformo: acetona (3:1 como fase móvil. Para discernir el metabolito con actividad antifúngica se realizó un ensayo de Bioautografía utilizando el hongo Aspergillus flavus. Como resultado, se observó una mancha con Rf entre 0.70-0.80 detectada a luz ultravioleta (255 nm y revelada con vainillina que presenta actividad antifúngica, por lo que es posible de una manera preliminar detectar los metabolitos antifúngicos mediante la combinación de estos dos métodos.

  9. Investigation of Volatiles Emitted from Freshly Cut Onions (Allium cepa L. by Real Time Proton-Transfer Reaction-Mass Spectrometry (PTR-MS

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    Mette Marie Løkke

    2012-11-01

    Full Text Available Volatile organic compounds (VOCs in cut onions (Allium cepa L. were continuously measured by PTR-MS during the first 120 min after cutting. The headspace composition changed rapidly due to the very reactive volatile sulfurous compounds emitted from onion tissue after cell disruption. Mass spectral signals corresponding to propanethial S-oxide (the lachrymatory factor and breakdown products of this compound dominated 0–10 min after cutting. Subsequently, propanethiol and dipropyl disulfide predominantly appeared, together with traces of thiosulfinates. The concentrations of these compounds reached a maximum at 60 min after cutting. Propanethiol was present in highest concentrations and had an odor activity value 20 times higher than dipropyl disulfide. Thus, propanethiol is suggested to be the main source of the characteristic onion odor. Monitoring the rapid changes of VOCs in the headspace of cut onion necessitates a high time resolution, and PTR-MS is demonstrated to be a very suitable method for monitoring the headspace of freshly cut onions directly after cutting without extraction or pre-concentration.

  10. Efecto de cinco Dosis de Heterorhabditis indica Poinat cepa P2M sobre la broca del café (Hypothenemus hampei Ferrari.

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    Yander Fernández Cancio

    2015-12-01

    Full Text Available Con el objetivo de evaluar el efecto de Heterorhaditis indica cepa P2M en el manejo de la broca del café (Hypotenemushampei Ferrari se realizó la investigación en condiciones controladas en el Laboratorio Provincial de Sanidad Vegetal de Sancti Spíritus con cinco dosis del patógeno: 20, 45, 75, 100 y 200 individuos juveniles infestiles/adulto (iji/adulto. Se diseñaron dos experimentos: variante 1 con aplicaciones directa sobre los adultos del insecto en placas Petri con siete repeticiones y variante 2 con la aplicación al suelo en bolsas de nylon con granos de la variedad Robusta con presencia de larvas y adultos del insecto. Se determinó la susceptibilidad de los adultos del insecto a las 24, 48 y 72 horas y el efecto de las dosis sobre el porcentaje de mortalidad de las larvas y adultos. Como resultado relevante de la variante 1 se destaca que los adultos tuvieron una susceptibilidad por encima del (50 % en 24 horas con las dosis superiores a 20 iji/adultos y en la variante 2 lo valores de mortalidad de las larvas fueron superiores a los adultos del insecto a las 72 horas. El nematodo constituye una alternativa viable en el control de la broca con valores de mortalidad de 50% en 24 horas.

  11. Genetic structure of Neisseria meningitidis serogroup C epidemic strains in South Brazil Estrutura genética de cepas epidêmicas de Neisseria meningitidis sorogrupo C do Sul do Brasil

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    Claudio Tavares Sacchi

    1995-08-01

    .No presente estudo, nós reportamos os resultados de uma análise, baseada na sorotipagem, multilocus enzimático (MEE e ribotipagem de N. meningitidis sorogrupo C isoladas de paciente com doença meningocócica no Rio Grande do Sul (RS e Santa Catarina (SC, onde o Centro de Controle Epidemiológico do Ministério da Saúde detectou um aumento do número de casos de doença meningocócica (DM devido a este sorogrupo nos últimos 2 anos (1992-1993. Nós demonstramos que a DM devido a cepas de N. meningitidis sorogrupo C no RS e SC que ocorreram nos últimos 4 anos foi devido principalmente por um clone (ET 40, com isolados indistinguíveis por sorogrupo, sorotipo, subtipo e até por ribotipagem. Um pequeno número de casos que não foram devidos a cepas do ET 40 representaram um grupo geneticamente relacionado, que provavelmente é uma nova linhagem gerada do clone ET 40, referido como complexo ET 11 A. Nós também analisamos cepas de N. meningitidis sorogrupo C isoladas na grande São Paulo em 1976 como um grupo representativo do primeiro ano pós-epidêmico na região. A ribotipagem, bem como MEE, puderam fornecer informações sobre as características clonais das cepas isoladas no período pós-epidêmico e também no Sul do Brasil. As cepas de 1976 possuem mais similaridades com as cepas endêmicas atuais do que com as cepas epidêmicas (1992-1993 por ribotipagem, sensibilidade a sulfonamida e MEE. Em conclusão, sorotipagem com anticorpos monoclonais (C:2b:P1.3, MEE (complexo ET11 e ET11A e ribotipagem usando a enzima de restrição ClaI, foram úteis em caracterizar estas cepas epidêmicas de N. meningitidis relacionadas com o aumento da incidência da DM em diferentes estados do sul do Brasil. É muito provável que estas cepas de N. meningitidis sorogrupo C possuam pouca ou nenhuma correlação genética com as cepas epidêmicas sorogrupo C de 1971-1975. A similaridade genética dos membros do complexo ET 11 e ET 11A foram confirmadas por ribotipagem usando-se 3

  12. VERIFICATION OF THE PRESENCE OF CAPSULE GENE SEQUENCES IN NASOPHARYNGEAL ISOLATES OF NONTYPEABLE HAEMOPHILUS INFLUENZAE FROM HEALTHY CHILDREN AT A BRAZILIAN DAY CARE CENTER Verificação da presença de seqüências do gene da cápsula em cepas não tipáveis de Haemophilus influenzae isoladas da nasofaringe de crianças saudáveis em uma creche brasileira

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    Maria Emilia Bonifácio da Silva

    2001-10-01

    Full Text Available Fifty-eight nasopharyngeal isolates of Haemophilus influenzae were collected from healthy children at a day care center, and nontypeable isolates were examined by Southern blot for the presence of capsule gene sequences. Seven isolates (12% demonstrated homology with capsule-specific sequences. One isolate was characterized as an H. influenzae type b capsule-deficient strain.Cinqüenta e oito cepas de Haemophilus influenzae foram isoladas da nasofaringe de crianças saudáveis que freqüentam uma creche, e através da técnica de Southern blot foi pesquisada nas cepas acapsuladas a presença de seqüências do gene capsular. Sete cepas (12% caracterizadas sorologicamente como acapsuladas mostraram homologia com seqüências específicas da cápsula. Uma cepa foi caracterizada com uma linhagem H. influenzae tipo b cápsula deficiente.

  13. Estudo parasitológico e anátomo-patológico da fase aguda da doença de Chagas em cães inoculados com duas diferentes cepas do Trypanosoma cruzi

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    Maria Alice Pedreira de Castro

    1985-12-01

    Full Text Available Cães jovens foram infectados com as cepas Y e CL do T. cruzi usando-se como inóculos 107 formas sangüíneas inoculadaspor via intraperitoneal e 2 x 10³ tripomastigotas metacíclicos obtidos do inseto vetor e inoculadospor via conjuntival. As cepas Ye CL induziram nos cães curvas deparasitemia totalmente distintas, confirmando dados parasitológicos obtidos em camundongos e coelhos. Com a cepa CL a parasitemia, com ambos os inóculos, foi gradualmente ascencional ao passo que com Y a parasitemia foi extremamente baixa, irregular e, com freqüência, subpatente. Com ambas as cepas o parasitismo e as lesões predominaram no miocárdio. Entretanto, com a cepa Y a miocardite foi sempre intensa desde as fases mais precoces da infecção, ao passo que com a cepa CL o processo inflamatório tomou-se acentuado somente a partir do 20.° dia. Freqüentemente a intensidade da miocardite observada em alguns animais não guardava relação com a parasitemia; em alguns cães com parasitemia subpatente, nos quais a infecção só foi diagnosticada pelo xenodiagnóstico, a intensidade da miocardite foi comparável àquela observada nos animais com parasitemia patente. Idêntica correlação também não foi assinalada em relação ao parasitismo tissular. Esses achados sugerem a participação de mecanismo imunológicos na gênese das lesões, ainda na fase aguda da infecção.Young dogs were inoculated with T. cruzi Y and CL strains either by intraperitoneal route with 107 blood forms or by ocular route with 2 x 10³ vector-derived trypomastigotes. With both inocula the patterns of parasitemia were significantly different, confirming data previously obtained in experimentally infected mice and rabbits. CL strain induced a gradual ascencional parasitemia whereas with Y the parasitemia was either subpatent or the number of parasites was very low, rapidly declining. Although myocarditis was present in most animals regardless of the strain used, the

  14. Potencial probiótico de cepas nativas para uso como aditivos en la alimentación avícola

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    Cecilia Lara Mantilla

    2012-11-01

    Full Text Available Normal 0 21 false false false ES-CO X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;} Título en ingles: Probiotic potential of native strains, for as feed additives for poultry Resumen: Se evaluó in vitro el potencial probiótico de cepas nativas aisladas de las heces de pollos asilvestrados (Gallus gallus pertenecientes a los géneros Lactobacillus sp, Bacillus sp y levaduras tipo saccharomyces sp; se determinó la actividad probiótica mediante pruebas de resistencia al ácido (pH  3, 4, 5, 6, 7, sales de bilis (0,05, 0,1, 0,15, 0.3 %, tolerancia al NaCl (2, 4, 7, 10 %, actividad antagónica (Salmonella sp, E. coli, determinación del tipo de fermentación, crecimiento a temperaturas (28,37,43°C y capacidad de crecimiento. Las cepas con mayor tolerancia se identificaron a través de pruebas bioquímicas y fermentación de carbohidratos. Como resultado se observó que tres microorganismos: Saccharomyces sp. (3, Bacillus sp. (7 y Lactobacillus sp. (14 poseen propiedades probióticas. Palabras claves: Gallus gallus; Saccharomyces sp.;  Bacillus sp.; Lactobacillus sp.; aditivos  microbianos. Abstract: Was evaluated in vitro the probiotic potential of native strains isolated from feces of wild chickens (Gallus gallus belonging to the genera Lactobacillus sp., Bacillus sp. and

  15. Allium cepa L. and Quercetin Inhibit RANKL/Porphyromonas gingivalis LPS-Induced Osteoclastogenesis by Downregulating NF-κB Signaling Pathway

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    Tatiane Oliveira

    2015-01-01

    Full Text Available Objectives. We evaluated the in vitro modulatory effects of Allium cepa L. extract (AcE and quercetin (Qt on osteoclastogenesis under inflammatory conditions (LPS-induced. Methods. RAW 264.7 cells were differentiated with 30 ng/mL of RANKL, costimulated with PgLPS (1 µg/mL, and treated with AcE (50–1000 µg/mL or Qt (1.25, 2.5, or 5 µM. Cell viability was determined by alamarBlue and protein assays. Nuclei morphology was analysed by DAPI staining. TRAP assays were performed as follows: p-nitrophenyl phosphate was used to determine the acid phosphatase activity of the osteoclasts and TRAP staining was used to evaluate the number and size of TRAP-positive multinucleated osteoclast cells. Von Kossa staining was used to measure osteoclast resorptive activity. Cytokine levels were measured on osteoclast precursor cell culture supernatants. Using western blot analysis, p-IκBα and IκBα degradation, inhibitor of NF-kappaB, were evaluated. Results. Both AcE and Qt did not affect cell viability and significantly reduced osteoclastogenesis compared to control. We observed lower production of IL-6 and IL-1α and an increased production of IL-3 and IL-4. AcE and Qt downregulated NF-κB pathway. Conclusion. AcE and Qt may be inhibitors of osteoclastogenesis under inflammatory conditions (LPS-induced via attenuation of RANKL/PgLPS-induced NF-κB activation.

  16. Regulation of miR394 in Response to Fusarium oxysporum f. sp. cepae (FOC) Infection in Garlic (Allium sativum L).

    Science.gov (United States)

    Chand, Subodh K; Nanda, Satyabrata; Joshi, Raj K

    2016-01-01

    MicroRNAs (miRNAs) are a class of post-transcriptional regulators that negatively regulate gene expression through target mRNA cleavage or translational inhibition and play important roles in plant development and stress response. In the present study, six conserved miRNAs from garlic (Allium sativum L.) were analyzed to identify differentially expressed miRNAs in response to Fusarium oxysporum f. sp. cepae (FOC) infection. Stem-loop RT-PCR revealed that miR394 is significantly induced in garlic seedlings post-treatment with FOC for 72 h. The induction of miR394 expression during FOC infection was restricted to the basal stem plate tissue, the primary site of infection. Garlic miR394 was also upregulated by exogenous application of jasmonic acid. Two putative targets of miR394 encoding F-box domain and cytochrome P450 (CYP450) family proteins were predicted and verified using 5' RLM-RACE (RNA ligase mediated rapid amplification of cDNA ends) assay. Quantitative RT-PCR showed that the transcript levels of the predicted targets were significantly reduced in garlic plants exposed to FOC. When garlic cultivars with variable sensitivity to FOC were exposed to the pathogen, an upregulation of miR394 and down regulation of the targets were observed in both varieties. However, the expression pattern was delayed in the resistant genotypes. These results suggest that miR394 functions in negative modulation of FOC resistance and the difference in timing and levels of expression in variable genotypes could be examined as markers for selection of FOC resistant garlic cultivars. PMID:26973694

  17. Post-treatment with plant extracts used in Brazilian folk medicine caused a partial reversal of the antiproliferative effect of glyphosate in the Allium cepa test.

    Science.gov (United States)

    Frescura, Viviane Dal-Souto; Kuhn, Andrielle Wouters; Laughinghouse, Haywood Dail; Paranhos, Juçara Terezinha; Tedesco, Solange Bosio

    2013-08-01

    Species of the genus Psychotria are used for multiple purposes in Brazilian folk medicine, either as water infusions, baths or poultices. This study was aimed to evaluate the genotoxic and antiproliferative effects of infusions of Psychotria brachypoda and P. birotula on the Allium cepa test. Exposure to distilled water was used as a negative control, while exposure to glyphosate was used as a positive control. The interaction of extracts (as a post-treatment) with the effects of glyphosate was also studied. Results showed that glyphosate and the extracts of both P. brachypoda and P. birotula reduced the mitotic index as compared with the negative control (distilled water). Surprisingly, however, both extracts from P. brachypoda and P. birotula caused a partial reversal of the antiproliferative effect of glyphosate when used as a post-treatment. Glyphosate also induced the highest number of cells with chromosomal alterations, which was followed by that of P. birotula extracts. However, the extracts from P. brachypoda did not show any significant genotoxic effect. Post-treatment of glyphosate-treated samples with distilled water allowed a partial recovery of the genotoxic effect of glyphosate, and some of the Psychotria extracts also did so. Notably, post-treatment of glyphosate-treated samples with P. brachypoda extracts induced a statistically significant apoptotic effect. It is concluded that P. brachypoda extracts show antiproliferative effects and are not genotoxic, while extracts of P. birotula show a less potent antiproliferative effect and may induce chromosomal abnormalities. The finding of a partial reversion of the effects of glyphosate by a post-treatment with extracts from both plants should be followed up.

  18. Efecto de las cepas nativas Paecilomyces sp. (Bainier y Lecanicillium sp. (Zimm en el control de Carmenta foraseminis Eichlin (Lepidoptera: Sesiidae en cultivos de cacao (Theobroma cacao L.

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    Wilmer Figueroa Medina

    2013-07-01

    Full Text Available El pasador del fruto, Carmenta foraseminis Eichlin, es un insecto que ha acentuado su ataque en cultivos de cacao (Theobroma cacao L. en los últimos años en Norte de Santander (Colombia. El objetivo de este estudio fue evaluar la patogenicidad de las cepas nativas Giav-3 Paecilomyces sp. y Giav-4 Lecanicillium sp. sobre larvas de C. foraseminis. Para el efecto, se realizaron aislamientos a partir de muestras de suelo recolectadas en el municipio de Tibú, Norte de Santander. Después de obtenidos los cultivos puros se procedió a la caracterización macroscópica y microscópica para la identificación del género de los aislados mediante claves taxonómicas. La infección fue realizada mediante inmersión de larvas en las suspensiones de los aislados en concentraciones de 0, 10(6, 10(7 y 10(8 conidios/ml. En ambos aislados se observó una tendencia lineal respecto a la mortalidad, la cual fue directamente proporcional a las concentraciones del inóculo. La CL50 y CL90 para Giav-3 fue de 10(6.95 y 10(8.70 conidios/ml y para Giav-4 de 10(6.6 y 10(8.04 conidios/ml, respectivamente. Lo cual indica que esta última requirió la menor concentración de inóculo para eliminar el 50% y 90% de la población tratada, lo que supone una mayor efectividad contra las larvas.

  19. Avaliação da sensibilidade de cepas de Malassezia furfur a imidas cíclicas Sensibility of evaluations of Malassezia furfur strains at cyclic imides

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    Edeltrudes de Oliveira Lima

    2002-12-01

    Full Text Available Malassezia furfur (Pityrosporum orbiculare é um fungo lipofílico, que está associado a pitiríase versicolor, foliculite, dermatite seborréica e atópica, fungemia e infecções sistêmicas. O tratamento é feito com soluções antimicóticas ou derivados imidazólicos, particularmente, o cetoconazol. Dentro das perspectivas de avaliação de novas alternativas para a terapêutica das infecções micóticas, determinou-se, nesse estudo, a atividade antifúngica de compostos imídicos. As imidas 3,4-dicloro-N-fenil-maleimida (6,3 µg/ml, 3,4-dicloro-N-benzil-maleimida (25 µg/ml e 3,4dicloro-N-fenil-propil-maleimida (20 µg/ml foram os compostos que apresentaram melhor atividade inibitória contra as cepas de M. furfur.Malassezia furfur (Pityrosporum orbiculare is a lipophilic microrganism and it has also been associated with pityriasis versicolor, folliculitis, seborrheic and atopic dermatitis, fungemia and systemic infections. The treatment comprehends antimicotics or imidazol derivatives solutions, specially cetoconazol. With purpose of evaluating new alternatives to the therapeutics of mycosis infections, the antifungical activity of cyclic imides was determinated in the present study. The imides 3,4-cichloro-N-phenylmaleimide (6,3 µg/ml, 3,4dichloro-N-benzyl-maleimide (25 µg/mL and 3,4dichloro-N-phenyl-propyl-maleimide (25 µg/mL were the compounds which produced the best activities of inhibition against strains of M. furfur.

  20. In Vitro Evaluation Of Selected Plant Extracts As Biocontrol Agents Against Black Mold Aspergillus Niger Van Tieghem Of Onion Bulbs Allium Cepa L.

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    Saifeldin A. F. El-Nagerabi

    2015-08-01

    Full Text Available Black mold disease caused by Aspergillus niger V. Tiegh. is the most devastating infection occurs in onions Allium cepa L. under field and store conditions. The use of biocontrol agents is ecofriendly approach for controlling seedborne and soilborne diseases compared to the use of toxic synthetic fungicides. This study has been designed to assess the contamination levels of onion seeds with A. niger and its effect on seed germination and to evaluate the in vitro antifungal activity of Prunus mahaleb seeds Commiphora myrrha resin 0.5 1.0 1.5 2.0 g100 ml Syzygium aromaticum dry buds clove and Panax ginseng roots extracts 0.5 1.0 2.0 2.5 g100 ml against black mold of onion bulbs. The fungus is seedborne pathogen which significantly contaminated onion seeds 89-100 and reduced seed germination 39-83. The extracts of clove caused 43-96 inhibition in spore germination followed by mahaleb 37-96 myrrha 33-88 and ginseng 34-87. The highest concentration of these extracts 3.0 did not affect seed germination but significantly reduced seed contamination by A. niger up to 84 80 71 and 65 for Syzygium aromaticum Syzygium aromaticum Panax ginseng and Prunus mahaleb respectively. The extracts apparently inhibited the fungal growth and mold development on stored onion bulbs which indicates the antifungal property of these extracts against A. niger. Therefore they can be recommended as effective biocontrol agents to reduce seed contamination and enhance the storability of onion bulbs. Thus the use of healthy and certified seeds for onion production is a priority.

  1. Regulation of miR394 in Response to Fusarium oxysporum f. sp. cepae (FOC Infection in Garlic (Allium sativum L

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    Subodh Kumar Chand

    2016-03-01

    Full Text Available MicroRNAs (miRNAs are a class of post transcriptional regulators that negatively regulate gene expression through target mRNA cleavage or translational inhibition and play important roles in plant development and stress response. In the present study, 6 conserved miRNAs from garlic (Allium sativum L. were analysed to identify differentially expressed miRNAs in response to Fusarium oxysporum f. sp. cepae (FOC infection. Stem-loop RT-PCR revealed that miR394 is significantly induced in garlic seedlings post treatment with FOC for 72 h. The induction of miR394 expression during FOC infection was restricted to the basal stem plate tissue, the primary site of infection. Garlic miR394 was also upregulated by exogenous application of jasmonic acid. Two putative targets of miR394 encoding F-box domain and cytochrome P450 (CYP450 family proteins were predicted and verified using 5’ RLM-RACE (RNA ligase mediated rapid amplification of cDNA ends assay. Quantitative RT-PCR showed that the transcript levels of the predicted targets were significantly reduced in garlic plants exposed to FOC. When garlic cultivars with variable sensitivity to FOC were exposed to the pathogen, an upregulation of miR394 and down regulation of the targets were observed in both varieties. However, the expression pattern was delayed in the resistant genotypes. These results suggest that miR394 functions in negative modulation of FOC resistance and the difference in timing and levels of expression in variable genotypes could be examined as markers for selection of FOC resistant garlic cultivars.

  2. Change in Flavonoid Composition and Antioxidative Activity during Fermentation of Onion (Allium cepa L.) by Leuconostoc mesenteroides with Different Salt Concentrations.

    Science.gov (United States)

    Lee, Yu Geon; Cho, Jeong-Yong; Kim, Young-Min; Moon, Jae-Hak

    2016-06-01

    The aim of this study is to investigate the change in flavonoid composition and antioxidative activity during fermentation of onion (Allium cepa L.) by Leuconostoc mesenteroides with different NaCl concentrations. In order to qualify and quantify the flavonoids during fermentation of onion, 7 flavonoids, [quercetin 3,7-O-β-d-diglucopyranoside (Q3,7G), quercetin 3,4'-O-β-d-diglucopyranoside (Q3,4'G), quercetin 3-O-β-d-glucopyranoside (Q3G), quercetin 4'-O-β-d-glucopyranoside (Q4'G), isorhamnetin 3-O-β-d-glucopyranoside (IR3G), quercetin (Q), and isorhamnetin (IR)], were isolated and identified from onion. During fermentation, the contents of flavonoid glucosides (Q3,7G, Q3,4'G, Q3G, Q4'G, and IR3G) gradually decreased, whereas the contents of flavonoid aglycones (Q, IR) gradually increased. Decline rates of the flavonoid glucosides increased with the addition of L. mesenteroides. Furthermore, the activity of β-glucosidase, which is produced by L. mesenteroides, is dose-dependently inhibited with different NaCl concentrations during fermentation. The presence of L. mesenteroides enhanced the antioxidative activity of onion as demonstrated using the 1,1-diphenyl-2-picrylhydrazyl, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), and reducing power assays. The enhancement of antioxidative activity was considered because the content of flavonoid aglycones increased during fermentation. However, the addition of NaCl may decrease the antioxidative activity; we surmise that this phenomenon occurs because of the inhibition of β-glucosidase by NaCl. Therefore, we conclude that the addition of NaCl may be useful for the regulation of antioxidative activity via the control of β-glucosidase action, during the fermentation of flavonoid glucoside-rich foods. PMID:27175820

  3. Micronucleus test of varying amounts of potassium bromate (KBrO3) on the meristematic cells of Allium cepa var. aggregatum root tips

    International Nuclear Information System (INIS)

    Four hundred twenty onion bulbs of the multiplier variety Allium cepa var. aggregatum were used as test materials to assay the micronucleus induction capacity of potassium bromate doses of 0, 5, 10, 25, 50, 75, and 100 parts per million. Microscopic analyses were done using onion root tips prepared according to a modified technique of Medina (1994). These analyses were done on root tips taken from onions grown in KBrO3 for three days and for five days. The study was conducted following a completely randomized design and the data were statistically analyzed using a non-parametric equivalent of the analysis of variance. A significant amount of micronucleated cells (MCN) were found among treated onions compared with the almost non-occurrence in the control groups (0 ppm). The Kruskal-Wallis H-test and the Wilcoxon two-samples tests revealed significant differences among treatment means and that a significant increase in the number of MCN occurs as the dose of KBr03 increased in both day experiments. Results from the higher doses of 50, 75, and 100 ppm were found to be significantly the same for the day 3 experiments while those of the day 5 higher doses are characterized by lack of clear cellular and nuclear outline such that scoring is difficult. Differences in MCN averages for the day 3 and 5 experiments appear to be insignificant. However, day 3 results show averages that are more significantly different from each other. These prove that the MCN can be used as an efficient and time-saving parameter for the allium test of chemicals with chromosome breaking capacities. (Author)

  4. Utilidad del modelo animal ratón-pulmón para evaluar la virulencia de posibles cepas vacunales de Shigella spp

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    Olga M. Martínez

    2008-04-01

    Full Text Available Shigella flexneri y Shigella sonnei, como cualquier otra especie del género Shigella, se sitúan entre los principales agentes etiológicos de las enfermedades diarreicas agudas, sobre todo aquellas que ocurren en los países en vías de desarrollo, aunque por la baja dosis infectante de este enteropatógeno no se excluyen los países desarrollados. Esta situación conlleva a la elaboración de vacunas para prevenir esta enfermedad y la necesidad de un modelo animal que pruebe la eficacia protectora e inmunogénica de posibles candidatos vacunales contra la shigellosis, situación que ha motivado numerosos estudios por la dificultad de demostrar la enteropatía intestinal en los monos y humanos. Lo anteriormente expuesto, más la capacidad de Shigella spp para mostrar resistencia a los antimicrobianos, motivó la realización de este trabajo. En el mismo se constató la utilidad del modelo animal ratón-pulmón para evaluar la virulencia de candidatos vacunales a partir de este microorganismo. Se utilizó la técnica de inoculación intranasal con una concentración entre 107 y 109 UFC de cepas de Shigella flexneri y Shigella sonnei. Por todos los resultados obtenidos con el modelo animal ratón-pulmón se concluyó que este modelo puede ser eficiente para los estudios preclínicos de cualquier candidato vacunal a partir de Shigella spp.

  5. Obtención y caracterización de mutantes fnr derivados de una cepa de Vibrio cholerae El Tor

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    Karen Marrero-Domínguez

    2013-01-01

    Full Text Available La bacteria anaerobia facultativa Vibrio cholerae es el agente causal del cólera. Su patogénesis comprende, entre otros procesos, la motilidad, la adherencia y la producción de la toxina del cólera y el pilus de expresión coregulada con la toxina, dos factores de virulencia esenciales. Trabajos previos invitro han mostrado que la expresión de los factores de virulencia en este microorganismo es diferencial y ocurre en respuesta a bajas tensiones de oxígeno; sin embargo, todos los reguladores que median esta respuesta no se conocen. La adaptación bacteriana al crecimiento en bajas concentraciones de oxígeno involucra a varios sistemas reguladores globales, entre los que se encuentra la proteína reguladora FNR (del inglés, Fumarate and Nitrate Reduction . El objetivo de este trabajo fue obtener mutantes en el genfnr derivados de una cepa de V. cholerae del biotipo El Tor y caracterizarlos invitro en cuanto a la producción de la toxina del cólera y el pilusco regulado con ella, así como la motilidad. Para esto, se obtuvieron dos mutantes que contenían al gen fnr parcialmente delecionado. La caracterización de estos mutantes arrojó que el regulador FNR activa específicamente la expresión de la toxina del cólera y no del pilus coregulado con la toxina en V. cholerae El Tor crecido en medio Syncase y anaerobiosis. Además, se encontró que este regulador contribuye a la motilidad de V. cholerae en anaerobiosis. Estos resultados identifican a FNR como un regulador involucrado en el control de la virulencia de V. cholerae en respuesta a la anaerobiosis, una señal fisiológicamente importante in vivo.

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

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    José Ávila

    2010-07-01

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

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

    Directory of Open Access Journals (Sweden)

    José Ávila

    2010-06-01

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

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

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    Andrea Paola Rodríguez Triviño

    2011-06-01

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

  9. Avaliação da atividade mutagênica e antimutagênica da Aloe vera em teste de Allium cepa e teste de micronúcleo em linfócitos humanos binucleados

    Directory of Open Access Journals (Sweden)

    Régis T. Sturbelle

    2010-07-01

    Full Text Available Algumas das substâncias presentes nos vegetais podem ter efeitos mutagênicos, enquanto outras podem atenuar ou anular estes efeitos. Estima-se que mais de 200 substâncias ativas façam parte do gel de Aloe vera, sendo que os polissacarídeos chegam a 30%, e muitos dos benefícios terapêuticos, nutricionais e cosméticos são a eles atribuídos. O objetivo deste trabalho foi determinar o efeito mutagênico e antimutagênico da solução de Aloe vera, em teste de Allium cepa e teste de micronúcleos em linfócitos humanos binucleados. Para as soluções, as folhas de Aloe vera foram trituradas, filtradas e esterilizadas. O teste de Allium cepa foi constituído de oito tratamentos e o de linfócitos, de cinco (com quatro repetições. Observou-se que na dose usual, a solução de Aloe vera não foi mutagência para o sistema de teste vegetal e nem para o humano. Já na dose dez vezes mais concentrada provocou um efeito citotóxico e mutagênico em Allium cepa. Em células vegetais a solução foi antimutagênica apenas quando colocada depois do paracetamol, enquanto que nas células humanas, essa ação se manifestou quando a solução foi utilizada ao mesmo tempo com o paracetamol.

  10. Caracterização de cepas de referência de Leptospira sp utilizando a técnica de pulsed field gel electrophoresis Characterization of Leptospira sp reference strains using the pulsed field gel electrophoresis technique

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    Lívia Machry

    2010-04-01

    Full Text Available INTRODUÇÃO: A leptospirose é uma zoonose endêmica, mundialmente distribuída, causada por bactérias do gênero Leptospira. Este gênero compreende espécies patogênicas e saprofíticas, com mais de 200 sorovares distintos, dificultando sua caracterização. A técnica de pulsed field gel electrophoresis tem sido empregada como uma ferramenta para auxiliar nesta caracterização. Os objetivos deste trabalho foram padronizar a técnica de PFGE, determinar os perfis moleculares das cepas de referência utilizadas pelo Laboratório de Referência Nacional para Leptospirose/Centro Colaborador da Organização Mundial de Saúde para Leptospirose e criar um banco de dados com estes perfis. MÉTODOS: Foram analisadas, por PFGE, dezenove cepas utilizando a enzima de restrição NotI. RESULTADOS: Cada cepa apresentou um perfil único que pode ser considerado como uma identidade genômica específica, com exceção dos sorovares Icterohaemorrhagiae e Copenhageni, cujos perfis foram indistinguíveis. CONCLUSÕES: Dessa forma, foi possível a criação de um banco de perfis moleculares que está sendo utilizado no Laboratório para a comparação e identificação de cepas isoladas de quadros clínicos.INTRODUCTION: Leptospirosis is an endemic zoonosis of worldwide distribution, caused by bacteria of the genus Leptospira. This genus includes pathogenic and saprophytic species, with more than 200 different serovars, thus making it difficult to characterize. The technique of pulsed field gel electrophoresis has been used as a tool to aid in this characterization. The aims of this study were to standardize the PFGE technique, determine the molecular profiles of reference strains used at the National Reference Laboratory for Leptospirosis/World Health Organization Collaborating Center for Leptospirosis and create a database with these profiles. METHODS: Nineteen strains were analyzed by means of PFGE, using the restriction enzyme NotI. RESULTS: Each strain

  11. Aislamientos de cepas fijadoras de nitrógeno y solubilizadoras de fósforo en un suelo alfisol venezolano Isolation of nitrogen-fixing and phosporus-solubilizing strains in alfisol soils of Venezuela

    Directory of Open Access Journals (Sweden)

    Learsy Padron

    2012-04-01

    Full Text Available Para evaluar el potencial de los suelos del Valle Medio del Río Yaracuy para la producción de biofertilizantes, se aislaron cepas fijadoras de nitrógeno (FNVL y solubilizadoras de fósforo (SF en suelos sometidos a diferentes condiciones de manejos. Para ello muestra rizosferica en los usos caña de azúcar (Sacharum oficcinarum, maíz (Zea mayz L., lechoza (Carica papaya, pasto (Brachiaria decumbens, además de un área bajo bosque natural, las muestras fueron tomadas en abril de 2010, las bacterias FNVL y SF fueron aisladas usando medio Ashby y Pikoskaya respectivamente, las principales propiedades químicas y físicas del suelo fueron evaluadas, para establecer su relación con el desarrollo de las cepas. Los resultados muestran que las FN se desarrollaron mejor en los usos pasto y caña de azúcar con 20 y 10 cepas respectivamente, lo que indica que las cepas FNVL se desarrollaron mejor en aquellos manejos con bajo contenido de materia orgánica o manejo intensivo, el mayor numero de bacterias SF se observaron en aquellos manejos con mayor contenido de fósforo (lechoza con 13 colonias, o en usos con adecuadas condiciones físicas para el desarrollo microorganismos (bosque, con 10 colonias.In order to evaluate the potential of soils in the Middle Valley of Yaracuy River in Venezuela for the production of biofertilizers, nitrogen fixed strains (FBN and phosphorus-solubilizing strains (SF were isolated in soils subjected to different management conditions. For this, rizhosferic samples in six different land uses were taken in April, 2010. Sugarcane (Sacharum officinarum, maize (Zea mayz L., pawpaw (Carica papaya, grass (Brachiaria decumbens and a forest area were sampled. Bacteria FNVL and SF were isolated using Ashby and Pikoskaya, respectively. Chemical and physical properties were evaluated in all soils to determine the relationship between them and the development of the strains. Results showed that Fn developed better in grass and

  12. Validación técnica de inoculantes en frijol con cepas de rhizobium eficientes en fijación de nitrógeno en Centroamérica

    OpenAIRE

    Oscar Acu\\u00F1a; Emigdio Rodr\\u00EDguez; Aurelio Llano; Vilma Ruth Calder\\u00F3n; Guillermo Flores; Abelardo Viana; Rogelio L\\u00E9piz

    2001-01-01

    Se realizó un ensayo de validación técnica de inoculantes en frijol elaborado con cepas de Rhizobium eficientes en fijación biológica de nitrógeno, con el objetivo de recabar mayor información sobre la bondad de esta tecnología en la producción comercial de frijol. El ensayo regional se sembró en 45 sitios, distribuidos en Costa Rica (20), Panamá (10), Nicaragua (10) y El Salvador (5), durante 1998 y 1999. Se incluyeron cuatro tratamientos: 1. Testigo absoluto; 2. Inoc...

  13. Validación técnica de inoculantes en frijol con cepas de rhizobium eficientes en fijación de nitrógeno en Centroamérica

    OpenAIRE

    Oscar Acuña; Emigdio Rodríguez; Aurelio Llano; Vilma Ruth Calderón; Guillermo Flores; Abelardo Viana; Rogelio Lépiz

    2001-01-01

    Se realizó un ensayo de validación técnica de inoculantes en frijol elaborado con cepas de Rhizobium eficientes en fijación biológica de nitrógeno, con el objetivo de recabar mayor información sobre la bondad de esta tecnología en la producción comercial de frijol. El ensayo regional se sembró en 45 sitios, distribuidos en Costa Rica (20), Panamá (10), Nicaragua (10) y El Salvador (5), durante 1998 y 1999. Se incluyeron cuatro tratamientos: 1. Testigo absoluto; 2. Inoculado; 3. Fertilización ...

  14. Bases ecofisiológicas de la producción de la cebolla (Allium cepa, L.): aportaciones para la mejora de las técnicas de cultivo en el Pla d'Urgell (Lleida)

    OpenAIRE

    Bosch i Serra, Àngela D.

    1999-01-01

    El presente estudio se plantea a fin de optimizar las prácticas de cultivo de cebolla (Allium cepa L.) a la vez que se profundiza en las bases ecofisiológicas de su producción. La experimentación se ubica en la comarca del Pla d´Urgell (Lleida) donde constituye la principal hortícola . El cultivar más común, con siembra a partir de enero, es Valenciana de Grano (V. de Grano). Se recolecta en la segunda quincena de agosto y se destina a consumo en fresco aunque almacenándose para ser comercial...

  15. Transformación de Agrobacterium tumefaciens CEPA LBA4404 con el vector binario pNOV022, selección in vitro y caracterización molecular

    OpenAIRE

    Santos Rodríguez Janneth Fabiola

    2002-01-01

    La caracterización molecular de la infección causada por Agrobacterium tumefaciensy el des-cubrimiento de que una parte del plásmido inductor de tumores (T-DNA) es transferido algenoma de las plantas que infecta, han permitido utilizar esta bacteria como sistema detransformación vegetal. La utilización de esta tecnología ha permitido a los científicos resolverproblemas con relación a especies cultivables. En el presente trabajo se realizó la transfor-mación de las cepas LBA4404 de Agrobacteri...

  16. Avaliação da tolerância à vancomicina em 395 cepas hospitalares de Staphylococcus aureus resistentes à oxacilina Evaluation of the tolerance to vancomycin in 395 oxacillin-resistant Staphylococcus aureus strains isolated from Brazilian hospitals

    Directory of Open Access Journals (Sweden)

    Geraldo A. Oliveira

    2001-01-01

    Full Text Available O objetivo deste estudo foi avaliar a presença de tolerância à vancomicina em cepas de Staphylococcus aureus resistentes à oxacilina (Orsa isoladas de quatro hospitais da cidade de São Paulo. Foram estudadas 395 cepas Orsa isoladas de pacientes hospitalizados entre outubro de 1998 e maio de 2000. A determinação da concentração inibitória mínima (CIM e da concentração bactericida mínima (CBM para vancomicina foi realizada conforme padronizado pelo National Committee for Clinical Laboratory Standards (NCCLS. A tolerância à vancomicina foi definida como a razão CBM/CIM > ou = 32. Do total de cepas estudadas, 10,4% apresentaram CIM de 0,5µg/ml para vancomicina; 41,3%, CIM de 1µg/ml; 42,2%, CIM de 2µg/ml; e 6,1%, CIM de 4µg/ml. Em média, 49,1% dos Orsa apresentaram tolerância à vancomicina. Em conclusão, a tolerância à vancomicina entre as cepas Orsa foi considerada elevada. Conseqüentemente, aumentam as chances de falhas no tratamento com vancomicina, além de aumentar o risco da emergência de Staphylococcus aureus vancomicina-intermediário.The objective of this study was to evaluate the presence of tolerance to vancomycin in oxacillin-resistant Staphylococcus aureus (Orsa strains isolated from four hospitals in the city of São Paulo. From October/1998 to May/2000 we analysed 395 Orsa strains isolated from hospitalized patients. MIC and MBC to vancomycin were determined as standardised by National Committee for Clinical Laboratory Standards (NCCLS. Tolerance was defined as the ratio MBC/MIC > or = 32. The results showed that 10.4% of the Orsa strains presented a MIC of 0.5µg/mL for vancomycin, 41.3% presented a MIC of 1µg/mL, 42.2% a MIC of 2µg/mL and 6.1% a MIC of 4µg/mL. On average, 49,1% of the Orsa presented tolerance to vancomycin. We conclude that the tolerance to vancomycin amongst the Orsa strains was considered high. These high levels of tolerance augment the chances of failure in the treatment with

  17. Control biológico de Rhizoctonia solani en plantas de papa criollaSolanum phureja usando cepas nativas de Pseudomonas fluorescens BIOCONTROL OF Rhizoctonia solani IN NATIVE POTATO (Solanum phureja) PLANTS USING NATIVE Pseudomonas fluorescens

    OpenAIRE

    GLORIA BAUTISTA; DANIEL URIBE; HENRY MENDOZA

    2007-01-01

    Rhizoctonia solani es un hongo fitopatógeno del suelo, el cual produce una reducción significativa del vigor de las plantas y de la producción de tubérculos en cultivos de papa. Es de gran interés la búsqueda de alternativas de manejo de esta enfermedad, especialmente desde la perspectiva de control biológico ya que los cultivos de papa son los mayores consumidores de plaguicidas de origen químicos en Colombia. Con el objeto de obtener una cepa del grupo de las Pseudomonas fluorescentes con l...

  18. Control biológico de Rhizoctonia solani en plantas de papa criollaSolanum phureja usando cepas nativas de Pseudomonas fluorescens BIOCONTROL OF Rhizoctonia solani IN NATIVE POTATO (Solanum phureja PLANTS USING NATIVE Pseudomonas fluorescens

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    GLORIA BAUTISTA

    2007-06-01

    Full Text Available Rhizoctonia solani es un hongo fitopatógeno del suelo, el cual produce una reducción significativa del vigor de las plantas y de la producción de tubérculos en cultivos de papa. Es de gran interés la búsqueda de alternativas de manejo de esta enfermedad, especialmente desde la perspectiva de control biológico ya que los cultivos de papa son los mayores consumidores de plaguicidas de origen químicos en Colombia. Con el objeto de obtener una cepa del grupo de las Pseudomonas fluorescentes con la capacidad para reducir los síntomas de la enfermedad producidos por R. solani, se realizó en un estudio previo el aislamiento y caracterización de una colección de aislamientos de Pseudomonas fluorescentes provenientes de diferentes cultivos de la región papera más productiva del país. Seis cepas nativas de P. fluorescens con buena, moderada o ninguna capacidad para inhibir el crecimiento fúngico in vitro fueron seleccionadas. A pesar de las diferencias encontradas en términos de la dinámica y capacidad de colonización, todas las cepas evaluadas indujeron el crecimiento en las plantas de S. phureja y redujeron los síntomas de la enfermedad producidos por R. solani a nivel de invernadero. Nuestros resultados sustentan la conclusión que la asociación de cepas de P. fluorescens con la rizosfera de S. phureja es una alternativa para el manejo de R. solani en papa.Rhizoctonia solani is a soil borne phytopathogen associated with reduced plant vigor and tuber production in potato crops. There is a huge interest to search alternatives of biological control management of this disease, because the potato crops in Colombia are the highest consumers of chemical pesticides in Colombia. In order to obtain a fluorescent Pseudomonas strain with the capacity to reduce the disease symptoms produced by R. solani, determination and isolation of the predominant fluorescent Pseudomonas in several potato crops of the main Colombian producing region was done

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

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    Jorge E Vidal

    2009-02-01

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

  20. Lesiones macro y microscópicas de intestino delgado de cerdos neonatos sin calostrar inoculados experimentalmente con cepas de E. coli fimbriadas Histopatholocial lesions in the small intestine of calostrum deprived pigs inoculated with strains of E. Coli bearing F4, F5, F6 y F41 fimbriaes

    OpenAIRE

    A.M CANAL; V. CUBILLOS; J. ZAMORA; G. REINHARDT; E. PAREDES; R. ILDEFONSO; Alberdi, A.

    1999-01-01

    La presente investigación se realizó con el propósito de evaluar los efectos patológicos de cepas enteropatógenas de E. coli que expresan antígenos fimbriales F4, F5, F6 y F41, administradas oralmente a cerdos neonatos que no ingirieron calostro. Los cerdos inoculados experimentalmente con las cuatro cepas enteropatógenas de E. coli presentaron diarrea acuosa y de color amarilla a las 4 h.p.i. Las lesiones macroscópicas se caracterizaron por congestión y abundante contenido acuoso, apreciándo...

  1. Respuesta diferencial de variedades de soya a la asociación simbiótica con cepas de Bradyrhizobium japonicum, en Oxisoles de la Orinoquia colombiana / Differental response of soybean varieties to the symbiotic association with Bradyrhizobium japonicum strains, in Oxisols of the Colombian Orinoquia

    OpenAIRE

    Valencia Ramírez, Rubén Alfredo

    2010-01-01

    El cultivo de la soya (Glycine max (L) Merril), en oxisoles de la Orinoquia colombiana presenta restricciones por la alta saturación de aluminio y en general, baja CIC y MO, que afectan la fijación biológica del N y el crecimiento normal de las plantas. La respuesta diferencial de variedades de soya a la inoculación con diferentes cepas de B. japonicum, se determinó mediante la evaluación de seis genotipos inoculados individualmente con las cepas ICA J-01, J-96, J-98, la mezcla de J-01 con J-...

  2. Characterization of Photorhabdusluminescens Growth for the Rearing of the Beneficial Nematode Heterorhabditis bacteriophora

    OpenAIRE

    Singh, Sunita; Eric, Moreau; Floyd, Inman; Leonard, Holmes D.

    2011-01-01

    Culturing the bioluminescent bacterium Photorhabdus luminescens in nutrient broth (NB) is used to recover phase I cells. These phase I cells were highly luminescent for up to 7 h in this media and the luminosity could also be seen with the naked eye after a 15 min eye adjustment period in a dark room. Red pigmentation is a known trait of phase I cells and was visually distinct within the culture media. The color shade of the red pigment varied on nutrient agar and in NB suggesting that the co...

  3. Characterization of Photorhabdus luminescens Growth for the Rearing of the Beneficial Nematode Heterorhabditis bacteriophora.

    Science.gov (United States)

    Singh, Sunita; Eric, Moreau; Floyd, Inman; Leonard, Holmes D

    2012-09-01

    Culturing the bioluminescent bacterium Photorhabdus luminescens in nutrient broth (NB) is used to recover phase I cells. These phase I cells were highly luminescent for up to 7 h in this media and the luminosity could also be seen with the naked eye after a 15 min eye adjustment period in a dark room. Red pigmentation is a known trait of phase I cells and was visually distinct within the culture media. The color shade of the red pigment varied on nutrient agar and in NB suggesting that the concentration of the pigment produced is dependent upon density of phase I cells within a specified area. The specific growth rate (μ) and doubling time (g) was determined during the logarithmic growth phase to be 0.36 h(-1) and 2.1 h, respectively in NB medium. The nematode-bacterium suspension was injected into larvae of Galleria mellonella to test for entomopathogencity. Within 24 h post-injection insect mortality was seen along with dark red pigmentation and extremely high luminosity indicating infection with P. luminescens. PMID:23997320

  4. Submerged monoxenic culture medium development for Heterorhabditis bacteriophora and its symbiotic bacterium Photorhabdus luminescens: protein sources.

    Science.gov (United States)

    Cho, Chun-Hwi; Whang, Kyung Sook; Gaugler, Randy; Yoo, Sun Kyun

    2011-08-01

    Most medium formulations for improving culture of entomopathogenic nematodes (EPN) based on protein sources have used enriched media like animal feed such as dried egg yolk, lactalbumin, and liver extract, among other ingredients. Most results, however, showed unstable yields and longer production time. Many of the results do not show the detailed parameters of fermentation. Soy flour, cotton seed flour, corn gluten meal, casein powder, soytone, peptone, casein hydrolysates, and lactalbumin hydrolysate as protein sources were tested to determine the source to support optimal symbiotic bacteria and nematode growth. The protein hydrolysates selected did not improve bacterial cell mass compared with the yeast extract control, but soy flour was the best, showing 75.1% recovery and producing more bacterial cell number (1.4×10⁹/ml) than all other sources. The highest yield (1.85×10⁵ IJs/ml), yield coefficient (1.67×10⁶ IJs/g medium), and productivity (1.32×10⁷ IJs/l/day) were also achieved at enriched medium with soybean protein. PMID:21876379

  5. Avaliação hematológica pós-desafio com cepa virulenta de Eimeria tenella em frangos de corte imunizados com cepa atenuada ou proteínas de esporozoítos de cepa homóloga Post-challenge hematological evaluation with virulent strain of Eimeria tenella in broilers immunized with attenuated strain or sporozoite proteins from homologous strain

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    Alexey Leon Gomel Bogado

    2010-03-01

    Full Text Available Foram avaliados os parâmetros hematológicos em frangos de corte imunizados e desafiados com Eimeria tenella. Pintos de corte fêmeas da linhagem Hubbard, livres de coccídios, foram mantidos em baterias metálicas e inoculados no terceiro dia. O experimento foi delineado por cinco tratamentos com três repetições cada, sendo: T1 controle negativo, T2 recebeu 500 oocistos esporulados atenuados via oral, T3 controle positivo, T4 recebeu vacina contendo 50 µg de proteínas de esporozoítos + Quil A e T5 recebeu Quil A + PBS, sendo os dois últimos por via nasal nos dias 0, 7 e 21. No dia 31, todos os tratamentos foram desafiados com cepa virulenta homóloga de E. tenella na dose de 8,0 × 10(4 oocistos, exceto T1. Uma semana depois, foi realizada amostragem de sangue, escore de lesão e contagem de oocistos cecais. Os parâmetros parasitológicos apresentaram significância estatística (p 0,05, pelo teste ANOVA. As correlações sugerem que os parâmetros sanguíneos foram afetados pelos efeitos do parasita no tecido, apresentando níveis de hemorragia e/ou hidratação.Hematological parameters were evaluated in broilers immunized and challenged with Eimeria tenella. Broiler chickens of Hubbard strain, females, coccidian-free, were kept in wire cages and inoculated on the third day. The experiment was designed to include five sorts of treatment with three replicates each. T1 was the negative control group, T2 received 500 attenuated sporulated oocysts by gavage, T3 was the positive control, T4 received 50 µg of sporozoite protein + Quil A vaccine, and T5 received Quil A without sporozoite protein + PBS, the last two through nasal route on days 0, 7, and 21. On the 31st day, all treatments were challenged with homologous virulent strain of E. tenella in the dose of 8.0 × 10(4 oocysts, with the exception of T1. One week later, blood sampling, lesion scores, and cecal oocyst count were carried out. The parasitological parameters showed

  6. Combination of physico-chemical analysis, Allium cepa test system and Oreochromis niloticus erythrocyte based comet assay/nuclear abnormalities tests for cyto-genotoxicity assessments of treated effluents discharged from textile industries.

    Science.gov (United States)

    Hemachandra, Chamini K; Pathiratne, Asoka

    2016-09-01

    Bioassays for cyto-genotoxicity assessments are generally not required in current textile industry effluent discharge management regulations. The present study applied in vivo plant and fish based toxicity tests viz. Allium cepa test system and Oreochromis niloticus erythrocyte based comet assay and nuclear abnormalities tests in combination with physico-chemical analysis for assessing potential cytotoxic/genotoxic impacts of treated textile industry effluents reaching a major river (Kelani River) in Sri Lanka. Of the treated effluents tested from two textile industries, color in the Textile industry 1 effluents occasionally and color, biochemical oxygen demand and chemical oxygen demand in the Textile industry 2 effluents frequently exceeded the specified Sri Lankan tolerance limits for discharge of industrial effluents into inland surface waters. Exposure of A. cepa bulbs to 100% and 12.5% treated effluents from both industries resulted in statistically significant root growth retardation, mito-depression, and induction of chromosomal abnormalities in root meristematic cells in comparison to the dilution water in all cases demonstrating cyto-genotoxicity associated with the treated effluents. Exposure of O. niloticus to the 100% and 12.5% effluents, resulted in erythrocytic genetic damage as shown by elevated total comet scores and induction of nuclear abnormalities confirming the genotoxicity of the treated effluents even with 1:8 dilution. The results provide strong scientific evidence for the crucial necessity of incorporating cyto-genotoxicity impact assessment tools in textile industry effluent management regulations considering human health and ecological health of the receiving water course under chronic exposure.

  7. Resistência in vitro de cepas do Plasmodium falciparum isoladas no sul do estado do Pará, em diferentes períodos: emergência de casos de multirresistência

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    A. A. Couto

    1993-03-01

    Full Text Available O presente estudo avalia a resposta de cepas de Plasmodium falciparum às drogas antimaláricas, através de testes in vitro, isoladas em 7 municípios do sul do Estado do Pará. Foram efetuados 69 testes para cloroquina e mefloquina, 62 para amodiaquina e 61 para quinino. Os resultados mostram elevada resistência para cloroquina (71%, relativamente baixa resistência para amodiaquina com (25,8% e para o quinino apenas 8,2%. Mefloquina revela ampla sensibilidade (100%, mas, demonstrando perda da mesma quando comparada em dois períodos distintos. Evidenciou-se também cepas multirresistentes em dois dos municípios estudados.The responses of Plasmodium falciparum to antimalarial drugs were evaluated through the in vitro test using blood sample collected from patients of 7 municipalities of the south of Pará State. Sixty nine microtests for chloroquine and mefloquine, 62 for amodiaquine and 61 for quinine were pet formed. The results showed a high resistance for chloroquine (71%, a relatively low resistance level for amodiaquine (25.8% and little resistance to quinine (8.2%. For mefloquine 100% of sensitivity was found.

  8. Escherichia coli aislada de cerditos diarreicos: Presunción de cepas productoras del Factor Citotóxico Necrosante (CNF Escherichia coli isolated from diarrheic piglets: Presumption of Cytotoxic Necrotizing Factor (CNF producing-strains

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    J. Zamora

    2000-01-01

    Full Text Available Se recolectaron 497 muestras de fecas diarreicas de cerditos lactantes de hasta 40 días de edad con la finalidad de aislar cepas de E. coli, a las cuales se les determinó la capacidad de producir toxinas que tuvieran la propiedad de producir lesiones en la línea celular HeLa como las que causa el CNF. Además, se investigó la capacidad hemolítica y la presencia de fimbrias. Se aislaron 275 cepas de E. coli, de las cuales 16 (5,8% eran productoras de la toxina "tipo CNF"; de éstas 5 (31,20% eran hemolíticas y a ninguna se les detectó fimbrias con los antisueros utilizadosFour hundred and ninety seven diarrheic fecal samples were obtained from suckling piglets (up to 40 days old in order to isolate E. coli strains. The samples were tested for the capacity to produce toxins able to induce lesions into HeLa cell line, similar to those induced by CNF. Besides, the hemolytic capacity and the presence of fimbria were also determined. A total of 275 strains of E. coli were isolated. Sixteen (5.8% were shown to be producers of the toxin "CNF type", and 5 (31.2% out these were hemolytic. Fimbria was not detected

  9. Leptospirosis en el Perú: I. Identificación de las cepas de leptospiras presentes en el perro y el gato e incidencia de la infección

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    Arístides Herrer

    1958-12-01

    Full Text Available Durante 1955 a 1957 se han realizado investigaciones acerca de la leptospirosis en el perro y el gato en la ciudad de Lima con la finalidad de determinar las cepas serológicas que infectan a dichos animales y la incidencia de la infección en relación con diversos factores. Todos los gatos y la mayoría de los perros estudiados procedían de la ciudad de Lima y sus inmediaciones; el resto de los perros, habían sido enviados a Lima procedentes de diversas localidades que se hallan a lo largo de la Costa. Las investigaciones efectuadas en dichos animales consisten en: a reacciones serológicas de aglutinación-lisis, en las que se empleó 11 cepas diferentes de leptospiras; b cultivos de la sangre y el riñón; y c observaciones al campo oscuro del triturado de riñón. Los principales resultados obtenidos son los siguientes: 1. De 444 perros en los que se realizaran las reacciones serológicas, en 206 (46.4% se ha verificado la presencia de anticuerpos a título que varió entre 1:100 a 1:30,000. Los anticuerpos verificados correspondieron casi en su totalidad a L. canícola Ruebush (84.5%, y L. icterohaemorrhagiae AB Winjberg (11.6%. 2. De los 206 perros con reacción serológica positiva, 66 (32% reaccionaron simultáneamente frente a dos cepas y 11 (5.3% frente a tres. En tales reacciones cruzadas la cepa L. ballum fue la que ofreció resultados positivos con mayor frecuencia (78.0% 3. En cuanto al título de los anticuerpos, en 154 casos (74.8% fue entre 1:100 y 1:300; en 49 (23.8%, entre 1:1,000 y 1:3,000; y en los tres restantes (1.4%, entre 1:10,000 y 1:30,000. 4. A semejanza de lo que sucede en otras partes, la incidencia de la leptospirosis canina es mayor durante los meses de temperatura más elevada (enero-marzo, del mismo modo, la incidencia es más alta en los animales machos (50% que en las hembras (35.9%. Ambos datos han sido obtenidos a base de los cultivos de riñón. 5. En 435 perros se hicieron cultivos de riñón y, en 113

  10. An attemp at reversibility and increase of the virulence of axenic strains of Entamoeba histolytica Tentativa de reversibilidade e aumento de virulência de cepas axônicas de Entamoeba histolytica

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    Maria Aparecida Gomes

    1993-12-01

    Full Text Available In this study we have tried to verify whether the interaction "in vitro" with bacteria or small pieces of normal hamster liver would modify the pathogenic behavior of axenic strains of E. histolytica: avirulent ones (ICB-32 and ICB-RPS, of attenuated virulence (ICB-CSP and HM1 and of mean virulence (ICB-462. Every attempt to render virulent, recover or increase the virulence of axenic strains of E. histolytica has failedNeste trabalho procuramos verificar se a interação "in vitro" com bactérias e fragmentos de fígado de hamster normal, modificaria o comportamento patogênico de cepas axênicas de E. histolytica avirulentas (ICB-32 e ICB-RPS; virulentas, porém atenuadas (ICB-CSP e HM1 e de média virulência (ICB-462. Todas as tentativas de tornar virulentas, restabelecer ou aumentar a virulência das cepas axênicas de E. histolytica utilizadas fracassaram

  11. Avaliação in vitro de uma cepa de campo de Boophilus microplus (Acari : Ixodidae resistente à amitraz In vitro evaluation of a field strain of Boophilus microplus (Acari:Ixodidae resistant to amitraz

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    Minerva Santamaría Vargas

    2003-08-01

    Full Text Available O uso dos acaricidas químicos ainda se constitui no principal instrumento de controle do carrapato bovino Boophilus microplus. No sul do Brasil, o amitraz aplicado por imersão e aspersão é o ingrediente ativo mais utilizado, nos últimos anos, contra as cepas de carrapatos resistentes aos organofosforados (OF e piretróides sintéticos (PS. Em conseqüência, torna-se importante a realização de investigações que possam contribuir para prolongar a vida útil desse ixodicida. No presente estudo, foi analisado o comportamento toxicológico de uma cepa de B. microplus colhida na localidade de Alegrete, Rio Grande do Sul, usando-se químicos da família dos OF, PS, misturas OF/PS, além do amitraz. Os resultados indicaram que a cepa denominada "Santa Luiza" apresentou fatores de resistência (FR que variaram entre 2,3 e 3,95 para OF, 23,3 e 147,56 para PS e de 3,76 a 21.57 para amitraz em testes realizados com larvas de carrapatos. A caracterização e purificação de uma cepa de B. microplus resistente ao amitraz permitem seu uso como cepa de referência para a avaliação biológica de ixodicidas alternativos, além de padronizar e validar métodos de diagnósticos toxicológicos que possam detectar resistência frente a esse acaricida.The use of chemical acaricide still remains as the main tool against the cattle tick Boophilus microplus. In Southern Brazil, amitraz applied by immersion and/or spray is the main active ingredient to control organophosphate and synthetic pyrethroid resistant strains. In consequence it is important to conduct investigations in order to prolong useful life of this ingredient. In this article, toxicological behaviour of a strain of Boophilus microplus named "Santa Luiza" collected in the locality of Alegrete, state of Rio Grande do Sul, Brazil, was analyzed against acaricides organophosphorous, pyrethroids, mixtures SP and OP and amitraz. Results showed factors of resistance from 2.3 to 3.95 to OP, 23.3 to 147

  12. Comportamento das cepas Y e Peruana do Trypanosoma cruzi no camundongo, após passagem em diferentes meios Behavior of the Y and Peruvian strains of Trypanasoma cruzi in mice, ofter passage through different media

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    Juracy B. Magalhães

    1985-03-01

    Full Text Available Com o objetivo de verificar se o comportamento morfobiológico e histopalógico de cerpa do Trypanosoma cruzi é mantido após modificações no seu meio de manutenção e multiplicação, foram estudados oito grupos de infecção experimental em camundongos com as cepas Y e Peruana, após manutenção nas seguintes condições cultura acelular em meio de Warren, criopreservação em Nitrogênio líquido durante trinta dias, passagem em triatomíneos e passagem em camundongos. Os parâmetros avaliados foram: parasitemia, mortalidade, sobrevida, morfologiaq dos parasitos no sangue periférico, tropismo tíssular e lesões histopatológicoas. Tanto com a cepa Y como Peruana, cada grupo experimental foi dividido em dois subgrupos de acordo com a dose de inóculo, sendo um inoculado com 10.000 e outro com 50.000 formas tripomastigotas, menos o inoculado com formas de triatomíneos em que o inóculo foi apenas com 10.000 tripomastigotas. Observou-se na infecção pela cepa Y, retardo na evolução da parasitemia nos inoculados com formas de cultura e atenuação de virulência com o inóculo de 10.000 formas. Os caracteres básicos da cepa foram mantidos com predominância de macrofagotropismo na fase inicial da infecção e miotropismo nas fases tardias,predominância de forma delgadas e elevada patogenicidade, com 100% de mortalidade embora com variação nos periodos de sobrevida. Na infecção pela cepa Peruana observou-se também retardo da evolução da parasitemia com o inóculo de 10.000 formas provenientes de triatomíneos, de cultura e de criopreservação. Entretanto, as características morfológicas, o tropismo tissular e a patogenicidade foram mantidos.The behavior of two strains of Trypanosoma cruzi (Y and Peruvian strains in experimental mouse infection, after being passed through different conditions of maintainance and cultivation was studied. The conditions were: Warren's acellular culture medium, cryopreservation in liquid

  13. Propagação da goiabeira serrana Feijoa sellowiana Berg, através da mergulhia de cepa Vegetative propagation of Feijoa sellowiana Berg through stool layring

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    J.C. Fachinello

    1992-01-01

    Full Text Available Este trabalho teve como objetivo verificar a influência de três tipos de mergulhia de cepa na obtenção de novas plantas de Feijoa sellowiana Berg. Para isso, foi conduzido experimento na EMBRAPA-CNPFT, Pelotas-RS, durante o período de agosto de 90 a julho de 91. Foram utilizados como tratamentos: T1 -corte total da planta a l0cm do nível do solo, seguido de amontoa; T2 - Sem corte da planta, seguido de amontoa a 20 cm de altura e T3 - corte total da planta a 10 cm do nível do solo e amontoa com terra a 20 cm de altura, 2 meses depois do corte. Os parâmetros avaliados foram: número de brotos emitidos por planta; número de brotos enraizados por plantas; número de raízes por broto e vigor dos brotos, representado pelas medidas do comprimento total e diâmetro da base. De acordo com o resultados obtidos o tratamento T3 foi o que proporcionou um maior número de brotos emitidos e enraizados. Para as demais variáveis não houve diferença significativa entre os tratamentos.An experiment to evaluate the effect of stool layring of feijoa was carried out in EMBR APA/CNPFT, Pelotas-RS, from August 90 to July 91. Three treatments of layring propagation were used: T1 - plant cutting 10 cm above the ground and covered with soil; T2 - No plant cutting and covered with soil up to 10 cm above the ground; and T3 - Plant cutting 10 cm above the ground and covered with soil two months later. The results obtained showed that the number of shoots and rooted shoots were more significant in T3. There was no diference between number of roots, diameter and length of shoots among treatments.

  14. Relations between boiling water test, standard germination test and field emergence of leek (Allium porrum L. and onion (Allium cepa L. seeds

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    Ismail Guvenc

    2012-12-01

    Full Text Available The aim of this study was to determine relations occurring between boiling water test, standard germination test and field emergence of leek (Allium porrum L. and onion (Allium cepa L. seeds. In this study, seeds of six lots ('Kalem', 'Ala', 'Ínegöl-A, B, C and D' from three cultivars of leek and seven onion cultivars ('Early Texas Grano' (ETG, 'Panku', 'Storm', 'Banko', 'Aki', 'Kisagün' and 'Banka' seeds were used as plant material and their viability was evaluated in boiling water test (BWT, standard germination test (SGT and field emergence (FE. The percentage of field emergence was evaluated at three sowing times: 20 May (FE-I, 10 June (FE-II and 20 July (FE-III. The mean germination of leek seeds varied from 77.5% to 100.0% and from 36.0% to 61.0% in SGT and BWT, respectively. While the range of results obtained in the boiling water test was from 38.5% to 60.0%, the range of results of the standard germination test was from 81.0% to 100.0% in onion seeds. The range of field emergence was between 18.5% ('Kisagün', FE-III and 72.0% (İnegöl-C', FE-II. Besides, the boiling water test was correlated highly significantly with SGT (r = 0.670**, FE-I (r = 0.923**, FE-II (r = 0.906** and FE-III (r = 0.939** in leek seeds. Similarly, BWT showed positive correlation with SGT (r = 0.568**, FE-I (r = 0.844**, FE-II (r = 0.933** and FE-III (r = 0.858** in onion seeds. In conclusion, the boiling water test is a new and reliable technique to test seed viability and it has a great potential to test rapidly germination and field emergence of leek and onion seeds at different sowing times.

  15. Effects of Onion (Allium cepa L. Extract Administration on Intestinal α-Glucosidases Activities and Spikes in Postprandial Blood Glucose Levels in SD Rats Model

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    Sun-Ho Kim

    2011-06-01

    Full Text Available Diets high in calories and sweetened foods with disaccharides frequently lead to exaggerated postprandial spikes in blood glucose. This state induces immediate oxidant stress and free radicals which trigger oxidative stress-linked diabetic complications. One of the therapeutic approaches for decreasing postprandial hyperglycemia is to retard absorption of glucose by the inhibition of carbohydrate hydrolyzing enzymes,α-amylase and α-glucosidases, in the digestive organs. Therefore, the inhibitory activity of Korean onion (Allium cepa L. extract against rat intestinal α-glucosidases, such as sucrase, maltase, and porcine pancreatic α-amylase were investigated in vitro and in vivo. The content of quercetin in ethyl alcohol extract of onion skin (EOS was 6.04 g/100 g dried weight of onion skin. The in vitro half-maximal inhibitory concentrations (IC50 of EOS and quercetin, a major phenolic in onion, on rat intestinal sucrase were 0.40 and 0.11 mg/mL, respectively. The postprandial blood glucose lowering effects of EOS and quercetin were compared to a known type 2 diabetes drug (Acarbose, a strong α-glucosidase inhibitor in the Sprague-Dawley (SD rat model. In rats fed on sucrose, EOS significantly reduced the blood glucose spike after sucrose loading. The area under the blood glucose-time curve (AUClast in EOS-treated SD rats (0.5 g-EOS/kg was significantly lower than in untreated SD rats (259.6 ± 5.1 vs. 283.1 ± 19.2 h·mg/dL. The AUClast in quercetin-treated SD rats (0.5 g-quercetin/kg was similar to in EOS-treated group (256.1 ± 3.2 vs. 259.6 ± 5.1 h·mg/dL. Results from this study indicates that although quercetin does have blood glucose lowering potential via α-glucosidase inhibition, there are other bioactive compounds present in onion skin. Furthermore, the effects of two weeks administration of EOS in a high carbohydrate-dietary mixture (Pico 5053 on sucrase and maltase activities in intestine were evaluated in SD rat model

  16. Cytotoxicity of Spent Pot Liner on Allium cepa root tip cells: A comparative analysis in meristematic cell type on toxicity bioassays.

    Science.gov (United States)

    Palmieri, Marcel José; Andrade-Vieira, Larissa Fonseca; Campos, José Marcello Salabert; Dos Santos Gedraite, Leonardo; Davide, Lisete Chamma

    2016-11-01

    Spent Pot Liner (SPL) is a waste generated during the production of aluminum. It is comprised of a mixture of substances most of which, like cyanide, aluminum and fluoride, are toxic. Previous studies indicate the highly toxic nature of SPL. However studies using cells of the differentiation/elongation zone of the root meristem (referred as M2 cells in this study) after a proper recovery period in water were never considered. Using these cells could be useful to further understanding the toxicity mechanisms of SPL. A comparative approach between the effects on M2 cells and meristematic cells of the proximal meristem zone (referred as M1 cells in this study) could lead to understanding how DNA damage caused by SPL behaves on successive generations of cells. Allium cepa cells were exposed to 4 different concentrations of SPL (2.5, 5, 7.5 and 10gL(-1)) mixed with soil and diluted in a CaCl2 0.01M to simulate the ionic forces naturally encountered on the environment. A solution containing only soil diluted on CaCl2 0.01M was used as control. M1 and M2 cells were evaluated separately, taking into account four different parameters: (1) mitotic alterations (MA); (2) presence of condensed nuclei (CN); (3) mitotic index (MI); (4) presence of micronucleus (MCN). Significant differences were observed between M1 and M2 roots tip cells for these four parameters accessed. M1 cells was more prompt to reveal citogenotoxicity through the higher frequency of MA observed. Meanwhile, for M2 cells higher frequencies of MCN and CN was noticed, followed by a reduction of MI. Also, it was possible to detect significant differences between the tested treatments and the control on every case. These results indicate SPL toxic effects carries on to future cells generations. This emphasizes the need to properly manage this waste. Joint evaluation of cells from both M1 and M2 regions was proven valuable for the evaluation of a series of parameters on all toxicity tests. PMID:27517141

  17. Um estudo comparativo das cepas Feira de Santana (Bahia e Porto Rico do Schistosoma Mansoni na infecção experimental do camundongo A comparative study of the Feira de Santana (Bahia and Porto Rico strains of Schistosoma mansoni in the experimental infection of mice

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    Zilton A. Andrade

    1985-03-01

    Full Text Available Dois grupos de camundongos, infectados com cem cercárias do S. mansoni, um com a cepa Porto Rico e outro com a cepa Feira de Santana mostraram resultados semelhantes quanto à recuperação de esquistossômulos pulmonares, recuperação de vermes do sistema porta, número de ovos por grama de tecido no figado e intestinos, lesões histopatológicas e mortalidade. Na realidade as diferenças entre animais infectados pela mesma cepa foram maiores que quando os dados conjuntos das duas cepas foram considerados.A comparative study of mice infected either with the Porto Rican or a Brazilian (Feira de Santana strain of Schistosoma mansoni failed to show any difference regarding recovery of five day lung worms, recovery of adult worms from the portal system, number of eggs per gram of tissue in liver and intestines, histopathology or mortality rate. In fact, the differences, although small, were greater among animals infected with the same strain, that when the total results from both strains were compared.

  18. LSSP-PCR para la identificación de polimorfismos en el gen cry1B en cepas nativas de Bacillus thuringiensis

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    Martha Ilce Orozco Mera

    2012-02-01

    Full Text Available Normal 0 21 false false false ES-CO X-NONE X-NONE MicrosoftInternetExplorer4 Título en ingles: LSSP-PCR to identify polymorphisms in the gene cry1B of Bacillus thuringiensis native strain Resumen: Se estandarizó la técnica LSSP-PCR (reacción en cadena de la polimerasa con un único oligonucleótido en condiciones de baja astringencia, para identificar polimorfismos del gen cry1B en aislamientos nativos de Bacillus thuringiensis (Bt. Se evaluaron 164 aislamientos nativos colombianos identificándose el gen cry1Ba en 11 de estos aislamientos. Los 11 fragmentos amplificados, junto con el de la cepa de referencia Bt subsp. aizawai HD137, se analizaron por LSSP-PCR y los patrones electroforéticos obtenidos se compararon cualitativamente. Con los productos amplificados mediante el oligonucleótido directo se construyó un dendrograma utilizando UPGMA que  mostró tres agrupamientos con similitud de 83, 79 y 68%. La agrupación con 68% de similaridad correspondió al aislamiento nativo BtGC120 que presentó el patrón de bandas más variable. Con el oligonucleótido reverso el aislamiento BtGC120 mostró una menor variabilidad (43%. La secuencia nucleotidica obtenida de este fragmento de 806 pares de bases mostró una identidad de 93% con la secuencia de los genes cry1Bc1 de Bt morrisoni y cry1Bb1 de la cepa BT-EG5847. Se predijo del marco de lectura +3 una proteína de 268 residuos aminoácidicos, con 88% de identidad con la proteína Cry1Bc. Esta  secuencia reveló dos dominios, una endotoxina N implicada en la formación del poro y otra endotoxina M relacionada en el reconocimiento del receptor. La evaluación biológica del aislamiento BtGC120 sobre larvas de primer instar del insecto plaga Spodoptera frugiperda, mostró una CL50 de 1,896 ng de proteína total por cm2. Este estudio muestra que la LSSP-PCR es una técnica que permite identificar de una manera específica variaciones en las secuencias de los genes cry de Bt, con potencialidad

  19. Evaluación de la producción de cuerpos fructíferos de cepas guatemaltecas del hongo comestible Rukoxil Tunay Che’ (Agrocybe cylindracea (DC.: Fr. Maire en diferentes sustratosEvaluation of the production of fruiting bodies of the

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    María del Carmen Bran

    2014-10-01

    Full Text Available En el presente estudio se determinó la producción de cuerpos fructíferos de cinco cepas nativas de Agrocybe cylindracea sobre tres sustratos y dos tratamientos térmicos, a través del porcentaje de eficiencia biológica y la medición del diámetro de los píleos. Se encontró que el mayor porcentaje de eficiencia biológica de las cepas en los sustratos evaluados fue 115.84 %, que correspondió al sustrato constituido por 29% paja de trigo mas 1% de harina de soya pasteurizado y obtenido por la cepa 58.01, la cual también produjo las mayores eficiencias biológicas en todos los sustratos evaluados. Al confrontar el porcentaje de eficiencia biológica en los diferentes sustratos, todas las cepas presentaron valores altos en el sustrato compuesto por 28% de paja de trigo, 1% harina de soya y CaCO3. Con respecto al diámetro de los cuerpos fructíferos, las cepas 58.01, 59.01, 60.01 y 638.08 produjeron píleos menores de 2 cm, entre 2-4 cm y mayores a 4.0 cm en los diferentes sustratos y tratamientos, excepto la cepa 59.01 que en el sustrato formulado con 29% de paja de trigo y 1% de harina de soya, solo produjo cuerpos fructíferos con píleos menores a 2 cm y entre 2-4 cm. En el análisis proximal de los basidiomas de las cepas evaluadas se obtuvo un alto porcentaje de proteínas, fibra cruda y carbohidratos, así como bajo porcentaje de grasas. Se recomienda que en futuras investigaciones o transferencia de tecnología a comunidades o entidades interesadas en el cultivo de este hongo, utilizar paja de trigo suplementada con harina de soya y como regulador de pH CaCO3, ya que en dicho sustrato se obtuvieron los mayores porcentajes de eficiencia biológica para la producción de cuerpos fructíferos de A. cylindracea.

  20. Extended-spectrum beta-lactamase production among ampicillin-resistant Escherichia coli strains from chicken in Enugu State, Nigeria Produção de beta-lactamase de espectro expandido por cepas de Escherichia coli resistentes a ampicilina isoladas de frango em Enugu State, Nigéria

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    K.F. Chah

    2007-12-01

    Full Text Available One hundred and seventy-two ampicillin-resistant E. coli strains isolated from commercial chickens in Enugu State, Nigeria, were screened for beta-lactamase production using the broth method with nitrocefin® as the chromogenic cephalosporin to detect enzyme production. Beta-lactamase producing strains were further examined for extended-spectrum beta-lactamase (ESBL production using the Oxoid combination discs method. One hundred and seventy (98.8% of the 172 ampicillin-resistant E. coli strains produced beta-lactamase enzyme. Sixteen (9.4% beta-lactamase producers were phenotypically confirmed to produce ESBLs. Six of the ESBL producing strains were only detected with ceftazidime versus ceftazidime/clavulanate combination while ten of the ESBL producers were detected with cefotaxime versus cefotaxime/clavulanate combination. Chicken may serve as a reservoir of ESBL-producing E. coli strains which could be transferred to man and other animals.Cento e setenta e duas cepas de Escherichia coli resistentes a ampicilina isoladas de frangos em Enugu State, Nigéria, foram avaliadas quanto à produção de beta-lactamase através do uso de método em caldo com nitrocefin® como indicador cromogênico da produção da enzima. Em seguida, as cepas produtoras de beta-lactamase foram examinadas quanto à produção de beta-lactamase de espectro expandido (ESBL através do método de discos combinados Oxoid. Entre as cepas de Escherichia coli resistentes a ampicilina, cento e setenta (98,8% produziram beta-lactamase. Testes fenotípicos indicaram que dezesseis (9,4% das cepas produtoras de beta-lactamase produziram ESBL. Seis cepas produtoras de ESBL foram detectadas apenas com a combinação ceftazidima versus cefotaxime/clavulanato, enquanto dez cepas produtoras de ESBL foram detectadas com a combinação cefotaxime versus cefotaxime/clavulanato. Frangos podem ser reservatório de cepas de E.coli produtoras de ESBL, que podem ser transferidos para o homem

  1. Análisis molecular de una cepa de virus de Newcastle de origen vacunal aislada a partir de un hisopado cloacal de aves sanas en Costa Rica - Molecular analysis of an isolated Newcastle disease virus strain obtained from cloacal swabs in healthy poultry farm in Costa Rica

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    León Rodríguez, Bernal

    2009-11-01

    Full Text Available ResumenEl virus de Newcastle (VNC es un paramyxovirus tipo 1 (APMV-1 quepertenece a la familia Paramyxoviridae, género Avulavirus, los cualesson virus de ARN no segmentados de una sola hebra de polaridadnegativa. En Costa Rica, se vacuna con cepas de baja patogenicidad y nunca se ha detectado brotes de cepas de alta patogenicidad. En el artículo se informa sobre el aislamiento de una cepa de VNC la cual se hizo a partir de un huevo embrionado inoculado con un hisopado cloacal de una muestra de una parvada de aves que no presentó signos clínicos de la enfermedad. La cepa fue identificada por la prueba de inhibición de la hemaglutinación y confirmada por PCR. posteriormente, se secuenció un fragmento de 310 pares de bases que incluyó el dominio de corte del gen F0 (posición 112 a 117 de la proteína, se demostró por análisis filogenéticos que la cepa aislada era de baja patogenicidad y de origen vacunal.SummaryA Newcastle Disease Virus was isolated from an embryonated egginoculated with a cloacal swab specimen fluid received for testing from a poultry flock without clinical signs. The sample was identify by the Hemagglutination-Inhibition Assay and confirmed by the Polymerase Chain Reaction technique (PCR. Subsequently, a region of the fusion protein gene F0 of 310 base pairs (that included the cut site at position 112 to 117 of the protein was sequenced and was demonstrated by phylogenetic and molecular analysis that the isolated strain was low pathogenic and vaccine origin.

  2. Response to chemotherapy with benznidazole of clones isolated from the 21SF strain of Trypanosoma cruzi (biodeme Type II, Trypanosoma cruzi II Resposta à quimioterapia com benzonidazol de clones isolados da cepa 21SF do Trypanosoma cruzi (biodema Tipo II, Trypanosoma cruzi II

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    Rozália Figueira Campos

    2005-04-01

    Full Text Available Susceptibility to chemotherapy with benznidazole was investigated of 5 clones isolated from the 21 SF strain (biodeme Type II, Trypanosoma cruzi II. Swiss mice were infected with the parental strain for each clone and submitted to chemotherapy with benznidazole (100mg/kg/day during 90 days. Treatment determined negativity of the parasitemia. Cure rates were evaluated by parasitological cure tests. Serology was evaluated for treated animals (titers from negative to 1:640 and untreated controls (1:160 to 1:640. Cure rates varied from 30 to 100% for the 5 clones, and were 25% for the parental strain. Results suggested that the variability of response to treatment of the clonal populations of Trypanosoma cruzi II strains is responsible for the high variation in the response to chemotherapy with benznidazole and nifurtimox by strains of this biodeme.A suscetibilidade à quimioterapia com o benzonidazol, de 5 clones isolados da cepa 21SF (biodema Tipo II, T. cruzi II, foi investigada. Camundongos suíços foram infectados com a cepa parental e com cada clone e submetidos à quimioterapia com benzonidazol (100mg/k/dia durante 90 dias. Os índices de cura foram avaliados pelos testes de cura parasitológicos. A sorologia foi avaliada para os animais tratados e (de negativo a 1: 640 e para os controles não tratados( 1:160 a 1:640. Os índices de cura variaram de 30% a 100% para os 5 clones sendo de 25% para a cepa parental. Os resultados sugerem que a variabilidade de resposta ao tratamento das populações clonais das cepas Trypanosoma cruzi II é responsável pela grande variação na resposta à quimioterapia com benzonidazol e nifurtimox das cepas deste biodema.

  3. DETERMINACIÓN DE MEDIOS DE CULTIVO Y PH PARA LA MASIFICACIÓN in vitro DE CEPAS DE Suillus luteus Aubl. ASOCIADAS A Pinus radiata D. Don Y Scleroderma citrinum Pers. ASOCIADAS A Eucalyptus globulus Labill. DE LA REGIÓN DEL BIOBÍO, CHILE

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    Marta González

    2015-02-01

    Full Text Available El uso de agentes biológicos en la producción en vivero ha aflorado como un elemento que permite no sólo mejorar la calidad morfológica y fisiológica de las plantas, sino que también posibilitar un mayor éxito en el ámbito silvicultural de una plantación. Estos agentes biológicos requieren de un ambiente óptimo para crecer, asociarse y reproducirse. El objetivo de este estudio fue determinar la dependencia del pH y el medio de cultivo en el crecimiento in vitro de distintas cepas de Suillus luteus y Scleroderma citrinum asociadas a Pinus radiata y Eucalyptus globulus, respectivamente. El estudio se realizó en condiciones controladas de temperatura y humedad, disponiendo los inóculos en placas Petri con diferentes medios cultivo, evaluando parámetros de crecimiento y biomasa a los 38 días para S. luteus y 105 días para S. citrinum. Los resultados indican que tanto el medio de cultivo, el pH del medio, así como las cepas de cada especie estudiada, son determinantes en las respuestas de crecimiento de los hongos ectomicorrícicos in vitro evaluados. Las cepas de S. luteus se desarrollaron adecuadamente en un medio de cultivo con abundancia de nutrientes (BAF, MMN como en baja presencia de ellos (EMA, y con pH más bien ácido (4,8 y 5,8. Por otro lado, las cepas de S. citrinum presentaron, para los mismos ambientes, un desarrollo inferior y lento, no obstante, la cepa Sc8 se reprodujo de forma óptima y rápida bajo un medio de cultivo BAF y con un pH moderadamente ácido de 5,8.

  4. Transformación de Agrobacterium tumefaciens CEPA LBA4404 con el vector binario pNOV022, selección in vitro y caracterización molecular

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    Santos Rodríguez Janneth Fabiola

    2002-06-01

    Full Text Available La caracterización molecular de la infección causada por Agrobacterium tumefaciensy el des-cubrimiento de que una parte del plásmido inductor de tumores (T-DNA es transferido algenoma de las plantas que infecta, han permitido utilizar esta bacteria como sistema detransformación vegetal. La utilización de esta tecnología ha permitido a los científicos resolverproblemas con relación a especies cultivables. En el presente trabajo se realizó la transfor-mación de las cepas LBA4404 de Agrobacterium tumefaciensy DH5a de Escherichia coli. Para tal finse utilizó la técnica de choque térmico incorporando el vector binario pNOV022, que contenía6868Resúmenes la construcción p35S-IP-t35S - pUBQ-PMI-tNos (promotor 35S del CaMV, inhibidor de protea-sas, terminador 35S del CaMV, promotor ubiquitina 3, fosfomanosa isomerasa y terminadorde la nopalinsintetasa. Igualmente se realizó selección de clones bacterianos transformados(basado en la resistencia a espectinomicina y/o estreptomicina y su caracterización molecularpor medio de PCR y un perfil de restricción. Este trabajo apuntó a producir un vector adecuadopara la transformación estable de papa criolla (Solanum phureja y de papa (Solanum tuberosum,un gen que confiere resistencia a insectos. Los resultados de las metodologías empleados evi-denciaron la introducción exitosa del plásmido recombinante en E. coliy A. tumefaciens. Si bienla eficiencia de transformación fue baja (0,032 x 10-8, los resultados de la PCR mostraron laamplificación de una secuencia de 500 pb del gen inhibidor de proteasa aislado a partir de lascepas transformadas. En cuanto al perfil de restricción los resultados no fueron los esperados,sin embargo, permiten diferenciar la cepa de A. tumefacienstransformada. Adicionalmente seestandarizó las condiciones de los medios de selección para diferenciar cepas transformadas.

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

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    Carlos Yábar V

    2003-10-01

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

  6. Avaliação da atividade mutagênica da infusão de Baccharis trimera (Less. DC. em teste de Allium cepa e teste de aberrações cromossômicas em linfócitos humanos Evaluation of mutagenic activity resulting from the infusion Baccharis trimera (Less. DC. using the Allium cepa test and a chromosomal test for aberrations in human lymphocytes

    Directory of Open Access Journals (Sweden)

    Daiane S. de Pinho

    2010-05-01

    Full Text Available A carqueja (Baccharis trimera(Less. DC. é uma planta medicinal da família Asteraceae muito utilizada como chá no sul do Brasil no tratamento de doenças renais, intestinas, estomacais e principalmente como emagrecedora. O objetivo desde trabalho foi de avaliar a mutagenicidade in vivoe in vitrodo chá e para isso foi realizado o teste de Allium cepaL. e o de aberrações cromossômicas em linfócitos humanos utilizando quatro tratamentos: T1 (água; T2 (20 g/L de carqueja; T3 (200 g/L de carqueja, e T4 (paracetamol, a 400 mg/L. Ambos os procedimentos foram analisados pelo teste Mann-Whitney U. Este estudo evidencia um efeito mutagênico do chá em células vegetais (Allium cepa e em células humanas (aberrações cromossômicas cultivadas, pois em ambos os testes, T2 e T3 obteve-se uma média mais elevada que nos outros tratamentos. Este estudo demonstra que o efeito é dependente da dose, portanto recomenda-se que o chá de carqueja seja consumido com moderação.Broom (Baccharis trimera(Less. DC. is a medicinal plant from Asteraceae that is commonly used as a tea in the south of Brazil for the treatment of renal, intestinal and stomach diseases. It is also used as a slimming agent. The aim of this study was to evaluate the mutagenicity of the tea in vivoand in vitro. In order to do this, the Allium cepatest was carried out and the chromosomal aberrations in human lymphocytes were tested using four treatments: T1 (water; T2 (20 g/L of broom; T3 (200 g/L of broom and T4 (paracetamol at 400 mg/L. Both procedures were analyzed using the Mann-Whitney U test. This study provided evidence of a mutagenic effect of the tea in vegetable cells (Allium cepa and in cultivated human cells. In tests T2 and T3 there was a higher average than the other treatments. This study shows that the effect is dependent on the dose. It is therefore recommended that broom tea be consumed with moderation.

  7. ESTUDIO DEL EFECTO QUIMIOTÁCTICO DE LOS EXUDADOS RADICALES DEL ARROZ SOBRE Azospirillum brasilense Sp7 Y A. brasilense R5(15. PRODUCCIÓN DE AUXINAS POR AMBAS CEPAS

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    Mabel Pazos

    2003-01-01

    Full Text Available El género Azospirillum agrupa bacterias diazotróficas de vida libre, ampliamente encontradas en suelos tropicales y subtropicales, en asociación con raíces de cultivos de importancia económica como arroz, trigo y diversas especies vegetales. La gran mayoría de los estudios realizados con este género han demostrado su distribución prácticamente universal y sus numerosos efectos sobre el crecimiento de las plantas que coloniza. En este trabajo se demuestra el efecto quimiotáctico que ejercen los exudados radicales del arroz variedad J-104 sobre dos cepas de A. brasilense (R5(15 y Sp7, así como la capacidad de ambas de producir auxinas 16.60 mg.mL-1 y 11.82 mg.mL-1 respectivamente.

  8. Antimicrobial susceptibilities of Listeria monocytogenes human strains isolated from 1970 to 2008 in Brazil Susceptibilidade antimicrobiana de cepas humanas de Listeria monocytogenes isoladas no período de 1970 a 2008 no Brasil

    Directory of Open Access Journals (Sweden)

    Cristhiane Moura Falavina dos Reis

    2011-04-01

    ampicilina a um aminoglicosídeo além de outros, em segunda escolha, representados por cloranfenicol, eritromicina, tetraciclina e rifampicina. O presente estudo teve como objetivo analisar o perfil de susceptibilidade aos antimicrobianos de amostras de origem humana isoladas nas últimas quatro décadas. MÉTODOS: Foram selecionadas 68 cepas provenientes de casos clínicos humanos ocorridos em diferentes regiões do país no período de 1970-2008. A susceptibilidade aos antimicrobianos testados foi determinada através dos critérios estabelecidos por Soussy pelo método de Kirby-Bauer e a concentração mínima inibitória realizada através do E-Test. RESULTADOS: A amostragem constituiu-se de 68 cepas, isoladas principalmente de líquido cefalorraquidiano, e hemocultura no período, pertencentes ao Laboratório de Zoonoses Bacterianas/LABZOO/Fiocruz. O sorovar L4b (60,3% foi o mais prevalente, seguido do sorovar 1/2a (20,6%, 1/2b (13,2% e aqueles mais raros representados por 1/2c, 3b e 4ab (5,9%. Todas as cepas foram sensíveis à ampicilina, cefalotina, eritromicina, gentamicina, teicoplanina e vancomicina. Apenas uma cepa (1,5% apresentou resistência à rifampicina, enquanto duas (3% foram resistentes à associação de sulfametoxazol-trimetoprim. CONCLUSÕES: Apesar de o estudo ter demonstrado uma baixa prevalência de amostras resistentes aos antimicrobianos indicados na terapêutica da listeriose humana, o sistema de monitoramento do perfil de resistência antimicrobiana é de extrema importância para a orientação do tratamento adequado, principalmente nas infecções em pacientes imunocomprometidos.

  9. Multiple drug resistant Staphylococcus aureus strains isolated from a fish market and from fish handlers Multiresistência a antimicrobianos de cepas de Staphylococcus aureus isoladas de uma feira de pescado e de seus manipuladores

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    W.F. Albuquerque

    2007-03-01

    Full Text Available The aim of this study was to investigate the presence of antibiotic resistant Staphylococcus aureus strains in fish stalls and in hands and nasal and oral cavities of fish handlers of the Mucuripe Fish Market, Fortaleza, Ceará, Brazil. All S. aureus isolates were resistant to Ampicillin and 44 % were multi-drug resistant.O objetivo da pesquisa foi investigar a presença de Staphylococcus aureus resistente a antibióticos nos boxes de venda de peixe e nas mãos e cavidades nasal e oral de manipuladores de pescado da Feira de Pescado do Mucuripe, Fortaleza, Ceará. Todas as cepas isoladas foram resistentes à ampicilina e 44% apresentaram multiresistência.

  10. Remoción de Cromo (VI) por una Cepa de Paecilomyces sp Resistente a Cromato Removal of Chromium (VI) in a Chromate-Resistant Strain of Paecilomyces sp

    OpenAIRE

    Cárdenas-González, Juan F.; Martínez-Juárez, Víctor M.; Ismael Acosta-Rodríguez

    2011-01-01

    Se analizó la capacidad de remoción de Cr(VI) de una cepa de Paecilomyces sp. Cuando el hongo se incubó en medio mínimo con glucosa y otras fuentes de carbono comerciales y de bajo costo, como azúcar moscabada y piloncillo ó glicerol, en presencia de 50 mg/L de Cr(VI), removió totalmente el Cr(VI). La reducción a Cr(III) ocurre en el medio de cultivo después de 7 días de incubación a 28°C, pH 4.0, y un inoculo de 38 mg. El hongo también redujo eficientemente la concentración de Cr(VI) a parti...

  11. Avaliação da atividade mutagênica e antimutagênica da Aloe vera em teste de Allium cepa e teste de micronúcleo em linfócitos humanos binucleados

    OpenAIRE

    Régis T. Sturbelle; Daiane S. de Pinho; Rossana G. Restani; de Oliveira, Gisele R.; Gilberto L. Garcias; Maria da Graça Martino-Roth

    2010-01-01

    Algumas das substâncias presentes nos vegetais podem ter efeitos mutagênicos, enquanto outras podem atenuar ou anular estes efeitos. Estima-se que mais de 200 substâncias ativas façam parte do gel de Aloe vera, sendo que os polissacarídeos chegam a 30%, e muitos dos benefícios terapêuticos, nutricionais e cosméticos são a eles atribuídos. O objetivo deste trabalho foi determinar o efeito mutagênico e antimutagênico da solução de Aloe vera, em teste de Allium cepa e teste de micronúcleos em li...

  12. The Development Status Quo and Implications in Mainland-Hong kong Service Trade under the Framework of CEPA%CEPA框架下内地与香港服务贸易的发展及苴启示

    Institute of Scientific and Technical Information of China (English)

    周金城

    2012-01-01

    Trade cooperation in services between Mainland and Hongkong under the framework of CEPA is mainly embodied in the mainland to Hongkong for unilateral open commitment, in which most preferential measures have reached the level of national treatment. The bilateral service trade between mainland and Hongkong develops fast, and focused on tourism, trade and transportation which belong to traditional service ar- eas. Service output of the mainland to Hongkong lags behind and with a low proportion? of modern service trade. They keeps each other's largest trading partners in the service trade. While Mainland improving the open- ing level to Hongkong service providers, Hongkong should improve the opening level to mainland service pro- vider. Mainland should actively undertake service industry transfering from Hongkong to enhance development level of service industry, deepen cooperation in the field of trade in service, and implementation of CEPA rules in the opening up of service trade.%CEPA框架下内地与香港服务贸易的领域合作,主要体现为内地向香港的单边开放承诺,大部分优惠措施已达到国民待遇水平。内地与香港双边服务贸易的发展速度较快,且集中在旅游、商贸和运输等传统服务领域;内地向香港的服务输出发展相对滞后,两地的现代服务贸易比重较低。两地应进一步深化在服务贸易领域的合作。

  13. Combination of physico-chemical analysis, Allium cepa test system and Oreochromis niloticus erythrocyte based comet assay/nuclear abnormalities tests for cyto-genotoxicity assessments of treated effluents discharged from textile industries.

    Science.gov (United States)

    Hemachandra, Chamini K; Pathiratne, Asoka

    2016-09-01

    Bioassays for cyto-genotoxicity assessments are generally not required in current textile industry effluent discharge management regulations. The present study applied in vivo plant and fish based toxicity tests viz. Allium cepa test system and Oreochromis niloticus erythrocyte based comet assay and nuclear abnormalities tests in combination with physico-chemical analysis for assessing potential cytotoxic/genotoxic impacts of treated textile industry effluents reaching a major river (Kelani River) in Sri Lanka. Of the treated effluents tested from two textile industries, color in the Textile industry 1 effluents occasionally and color, biochemical oxygen demand and chemical oxygen demand in the Textile industry 2 effluents frequently exceeded the specified Sri Lankan tolerance limits for discharge of industrial effluents into inland surface waters. Exposure of A. cepa bulbs to 100% and 12.5% treated effluents from both industries resulted in statistically significant root growth retardation, mito-depression, and induction of chromosomal abnormalities in root meristematic cells in comparison to the dilution water in all cases demonstrating cyto-genotoxicity associated with the treated effluents. Exposure of O. niloticus to the 100% and 12.5% effluents, resulted in erythrocytic genetic damage as shown by elevated total comet scores and induction of nuclear abnormalities confirming the genotoxicity of the treated effluents even with 1:8 dilution. The results provide strong scientific evidence for the crucial necessity of incorporating cyto-genotoxicity impact assessment tools in textile industry effluent management regulations considering human health and ecological health of the receiving water course under chronic exposure. PMID:27209118

  14. In vitro effect of josamycin in strains of Rhodococcus equi isolated from pulmonar infections in foals / Efeito in vitro da josamicina em cepas de rhodocaccus equi isoladas de afecções pulmonares em potros

    Directory of Open Access Journals (Sweden)

    Jaime Galvão Dias Júnior

    2000-12-01

    Full Text Available Antmicrobial susceptibility test was performed in thirty-one samples of Rhodococcus equi isolated from iung infections in foals. Among the antimicrobial tosted, erythromycin (100,0 %, rifampin (96.3%. neomycin (93,6 %Josamycin (90,4% and gentamicin (90,4 %presented the highest sensitivity against R- equi- The most-common occurrence of resistance was observed from cephalexim (100,0 %}, lincomycin (100,0 %, cephalothin (96,3 %. oxacillin (96,8 %, penicillin G (96,8 %, amoxicillin (90,3 % and trimethoprim/sulfamethoxazole (83,8 %. The highest susceptibility of the R. equi to josamycin, suggest the drug as alternative for therapy of R. equi infections in foals.Procedeu-se o teste de sensibilidade microbiana in vitro pelo teste de difusão com discos em 31 cepas de Rhodococcus equi. isoladas de afecções pulmonares cm potros. frente a 20 antimicrobianos. Os maioires índices de sensibilidade de R. equi foram constatados para entromicina (100,0 %, níampicina (96.8 %}t ncomicina (93. 6 %. josamicina (90.4% e gentamicina (90A %. Os maiores índices de resistência do agente foram verificados para cefalexina (100,0%, lincomicina (100.0%, cefalotina (96.8 %, oxacilino (96,8 %}, penicilina G (96,3 %, amoxicilina (90.3 % e sulfametoxazol/trimetoprim (83,8 %. A alta sensibilidade das cepas de R. equi para a josamicina, sugere a possibilidade de utilização da droga como alternativa no tratamento da rodococose em potros.

  15. Remoción de Cromo (VI por una Cepa de Paecilomyces sp Resistente a Cromato Removal of Chromium (VI in a Chromate-Resistant Strain of Paecilomyces sp

    Directory of Open Access Journals (Sweden)

    Juan F Cárdenas-González

    2011-01-01

    Full Text Available Se analizó la capacidad de remoción de Cr(VI de una cepa de Paecilomyces sp. Cuando el hongo se incubó en medio mínimo con glucosa y otras fuentes de carbono comerciales y de bajo costo, como azúcar moscabada y piloncillo ó glicerol, en presencia de 50 mg/L de Cr(VI, removió totalmente el Cr(VI. La reducción a Cr(III ocurre en el medio de cultivo después de 7 días de incubación a 28°C, pH 4.0, y un inoculo de 38 mg. El hongo también redujo eficientemente la concentración de Cr(VI a partir de tierra contaminada. Los resultados indican que la cepa de Paecilomyces sp tiene la capacidad de reducir Cr(VI a Cr(III, y por lo tanto puede utilizarse para eliminar la contaminación por Cr(VI.The ability to reduce chromium (VI by a fungal strain of Paecilomyces sp was studied. When it was incubated in minimal medium with glucose and other inexpensive commercial carbon sources such as unrefined and brown sugar or glycerol, in the presence of 50 mg/L of Cr(VI, the strain caused complete removal of Cr(VI. The reduction to Cr (III occurs in the growth medium after 7 days of incubation, at 28°C, pH 4.0, and inoculum of 38 mg. Also, the fungi efficiently reduced the concentration of Cr(VI from contaminated soil wastes. The results indicate that the fungal strain of Paecilomyces sp has the capacity of reducing Cr(VI to Cr(III, and therefore it could be useful for the removal of Cr(VI pollution.

  16. Biochemical characteristics of typical and atypical Staphylococcus aureus in mastitic milk and environmental samples of Brazilian dairy farms Características bioquímicas de cepas típicas e atípicas de Staphylococcus aureus isoladas de leite mastítico e de amostras ambientais de fazendas leiteiras brasileiras

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    Wladimir Padilha da Silva

    2000-06-01

    Full Text Available This study reports results on the biochemical characteristics of 274 Staphylococcus aureus strains isolated from mastitic milk, hands of milkmen and milking machines. Features included colony morphology on Baird Parker agar (BPA, catalase, coagulase and thermonuclease tests. API-Staph (bioMérieux, France was used as reference identification system. 39.4% of the colonies on BPA identified as S.aureus were atypical. They were more frequent in milk samples (94.4%. All S.aureus strains were coagulase positive but intensity of the test varied according to the source: environmental strains were 3+ or 4+, while 17.1% of strains isolated from milk presented only 1+ or 2+ results. The majority of atypical S.aureus strains presented a 4+ coagulase result. 2.2% of S.aureus strains were thermonuclease negative. Sixteen thermonuclease positive and coagulase positive strains were identified as S.hyicus.Esse trabalho relata as características bioquímicas de 274 cepas de Staphylococcus aureus isoladas de leite mastítico, de mãos de ordenhadores e de ordenhadeiras mecânicas. Foram avaliadas as características morfológicas em agar Baird Parker (BPA e os resultados para os testes de catalase, coagulase e termonuclease. API-Staph foi empregado como sistema de referência para identificação. 39,4% das colônias em BPA identificadas como S.aureus apresentaram morfologia atípica, sendo mais freqüentes em leite (94,4%. Todas as cepas identificadas como S.aureus foram coagulase positivas mas a intensidade da reação variou de acordo com a fonte: cepas isoladas de amostras ambientais foram 3+ ou 4+, enquanto 17,1% daquelas isoladas de leite foram apenas 1+ ou 2+. A maioria das cepas de S aureus com morfologia atípica em agar Baird-Parker apresentaram coagulase 4+. 2,2% das cepas de S.aureus foram termonuclease negativas. 16 cepas termonuclease positivas e coagulase positivas foram identificadas como S.hyicus.

  17. Avaliação de três cepas de vírus rábico, antigenicamente distintas, em camundongos: II - Estudo da disseminação viral por diferentes órgãos Evaluation of three antigenically different rabies virus strains in mice: II -Study of the viral dissemination in different organs

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    Pedro Manuel Leal Germano

    1988-12-01

    Full Text Available Estudou-se, comparativamente, o grau de disseminação de três cepas de vírus rábico, duas de origem de cão, Jales e Nigéria, e uma de origem de morcego, DR 19, com perfis antigênicos do nucleocapside distintos. Estas cepas foram inoculadas por via intramuscular, na face interna da coxa, em dois grupos de camundongos, com 21 e 28 dias de idade. Os animais foram mantidos em observação por um período total de 30 dias, e dos animais vitimados pela infecção, foram coletados diferentes órgãos, músculo lingual, coração, pulmão, rim e fígado, além do cérebro e da medula espinal, para avaliar-se o grau de disseminação de cada cepa viral, através da prova de imunofluorescência direta (IFD. Os resultados obtidos evidenciaram que os decalques de cérebro e de medula espinal apresentaram total concordância na prova de IFD, constatando-se as maiores diferenças com as cepas Jales e Nigéria, situando-se a cepa DR 19, intermediariamente, a estas duas. O músculo lingual foi o órgão que apresentou maior freqüência de positividade para ambos os grupos etários e para as três cepas virais.A study was conducted to compare three strains of rabies virus, two of them, Jales and Nigeria, isolated from dogs, and the other DR 19, from vampire bats, with different nucleo-capside antigenic characteristics. These strains were intramuscularly inoculated in the inner side of the thigh of 21 and 28 day-old mice. The animals were observed for 30 days and different organs: brain, spinal cord, tongue, heart, lung, kidney and liver were collected from the animals which died of rabies for the dissemination study by the immunofluorescent antibody technique (IFA. This technique showed complete agreement between brain and spinal cord. The greatest differences in dissemination were observed between Jales and Nigeria strains. The results observed for the DR 19 strain were situated between those of the two dog strains. The greates degree of dissemination

  18. EFECTO DE LA MICORRIZA Y GALLINAZA SOBRE LA PRODUCCIÓN Y LA CALIDAD DE CEBOLLA CABEZONA (Allium cepa L. ‘Yellow Granex’ EFFECT OF MYCORRHIZAE AND HEN MANURE FERTILIZATION ON YIELD AND QUALITY OF ONION (Allium cepa L. ‘YELLOW GRANEX’

    Directory of Open Access Journals (Sweden)

    Maritza Yolima Agudelo Becerra

    2004-06-01

    Full Text Available En condiciones de campo se evaluó el efecto de hongos micorrizógenos y de gallinaza, comparado con la aplicación de fertilizante mineral, sobre la producción y la calidad de cebolla cabezona (Allium cepa L. ‘Yellow Granex’ en el municipio de Cucaita - Boyacá (Colombia. Las semillas germinaron en suelo, y 70 días después de la germinación, se seleccionaron plántulas de tamaño uniforme, se transplantaron y se inocularon (0,86 ton/ha de Mycofertil o no con hongos micorrícicos. Se aplicaron tres dosis de gallinaza (0 - 1 y 2 ton/ha y 0,5 ton / ha de fertilizante comercial 15 - 15 - 15. Se evaluó la producción total, la producción de bulbos de primera y segunda calidad, así como de los bulbos dañados. Se utilizó el diseño de bloques al azar con tres replicaciones. Se hizo un análisis de varianza (ANOVA para los datos registrados y se realizó la prueba de comparación de medias de Duncan con un nivel de significancia de 0,01. Los resultados mostraron que las micorrizas y la gallinaza incrementaron la producción total y de las cebollas de primera calidad, comparados con la aplicación fertilizante mineral solo o complementado con 1 ó 2 ton/ha de gallinaza. Sin embargo, la producción de cebolla de segunda calidad fue superior en las parcelas tratadas con micorrizas, comparadas con los otros tratamientos sin ellas. Por otro lado, la adición de micorrizas redujo la cantidad de bulbos dañados. El tratamiento con fertilizante mineral solo presentó la producción total más baja y la menor producción de cebolla de primera y segunda calidad, pero la más alta producción de cebollas dañadas, en comparación con los demás tratamientos evaluados. Los resultados se discutieron con base en el incremento en la toma de nutrientes y en la reducción del efecto de patógenos radiculares en las plantas colonizadas con micorrizas.Under field conditions, the effects of mycorrhizae and hen manure fertilization, compared to the application

  19. Genetic relationships of Corynebacterium diphtheriae strains isolated from a diphtheria case and carriers by restriction fragment length polymorphism of rRNA genes Relação genética de cepas de Corynebacterium diphtheriae isoladas de caso e seus contatos por RLFP de rRNA gene

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    Claudio Tavares Sacchi

    1995-08-01

    Full Text Available In the present study we report the results of an analysis, based on ribotyping of Corynebacterium diphtheriae intermedius strains isolated from a 9 years old child with clinical diphtheria and his 5 contacts. Quantitative analysis of RFLPs of rRNA was used to determine relatedness of these 7 C.diphtheriae strains providing support data in the diphtheria epidemiology. We have also tested those strains for toxigenicity in vitro by using the Elek's gel diffusion method and in vivo by using cell culture method on cultured monkey kidney cell (VERO cells. The hybridization results revealed that the 5 C.diphtheriae strains isolated from contacts and one isolated from the clinical case (nose case strain had identical RFLP patterns with all 4 restriction endonucleases used, ribotype B. The genetic distance from this ribotype and ribotype A (throat case strain, that we initially assumed to be responsible for the illness of the patient, was of 0.450 showing poor genetic correlation among these two ribotypes. We found no significant differences concerned to the toxin production by using the cell culture method. In conclusion, the use of RFLPs of rRNA gene was successful in detecting minor differences in closely related toxigenic C.diphtheriae intermedius strains and providing information about genetic relationships among them.No presente estudo, nós reportamos os resultados de uma análise, baseada na ribotipagem de cepas de C. diphtheriae intermedius isoladas de uma criança de 9 anos com difteria e seus 5 contatos. Análise quantitativa por RFLP de rRNA foi usada para determinar a relação destas 7 cepas de C. diphtheriae fornecendo dados de interesse epidemiológico. Nós também testamos estas cepas para toxicidade in vitro usando método de difusão de Elek e in vivo usando método de cultura celular com células VERO. Os resultados de hibridização revelaram que as 5 cepas de C. diphtheriae isoladas dos contatos e uma isolada do caso (cepa isolada

  20. Production of bacteriocin-like inhibitory substances (BLIS by Streptococcus salivarius strains isolated from the tongue and throat of children with and without sore throat Produção de substâncias inibidoras semelhantes à bacteriocina por cepas de Streptococcus salivarius, isoladas da língua e garganta de crianças com e sem dor de garganta

    Directory of Open Access Journals (Sweden)

    Vera Fantinato

    1999-12-01

    Full Text Available Streptococcus salivarius strains, isolated from children with and without sore throat, were tested for bacteriocin production against Streptococcus pyogenes. S. salivarius strains producing bacteriocin-like inhibitory substances (BLIS against S. pyogenes were more frequently found in children without sore throat. These results suggest that these children may be protected against sore throat by the presence of BLIS-positive S. salivarius strains.Cepas de Streptococcus salivarius, isoladas de crianças com e sem dor de garganta, foram testadas quanto à produção de bacteriocina contra Streptococcus pyogenes. Os resultados mostraram que as crianças que não tinham dor de garganta possuiam, na boca, cepas de bactérias produtoras de substâncias inibidoras semelhantes à bacteriocina contra S. pyogenes.

  1. Vaccination of C57BL/10 mice against cutaneous leishmaniasis using killed promastigotes of different strains and species of Leishmania Vacinação de camundongos C57BL/10 contra leishmaniose com promastigotas mortas de diferentes cepas e espécies de Leishmania

    Directory of Open Access Journals (Sweden)

    Wilson Mayrink

    2002-04-01

    Full Text Available Antigenic extracts from five Leishmania stocks were used to vaccinate C57BL/10 mice. The Leishvacin® and PH8 monovalent vaccine yielded the highest IFN-gamma levels in the supernatants of spleen cell culture from vaccinated animals. Each single strain immunized group showed evidence of protective immunity six months after the challenge with promastigotes of Leishmania (Leishmania amazonensis. No differences were detected between the vaccinated groups. It can be concluded that vaccines composed of single Leishmania stocks can provide protection to C57BL/10 mice against L. (L. amazonensis infection.Estudos anteriores revelaram que uma vacina preparada com promastigotas mortas de cinco cepas de Leishmania pode induzir uma imunidade protetora para a leishmaniose tegumentar americana no homem e em modelos experimentais. Um dos problemas do uso desta vacina é a complexidade de sua composição e a necessidade de se incorporar diferentes cepas de Leishmania. Por esta razão, extratos antigênicos de cada uma das cinco cepas constituintes da vacina foram preparados e usados individualmente em estudos imunológicos com camundongos C57BL/10. A Leishvacin® e a vacina monovalente PH8 induziram os maiores níveis de Interferon-g (IFN-gama detectado no sobrenadante de células esplênicas dos animais vacinados. Cada grupo imunizado com vacinas monovalentes desenvolveram uma imunidade protetora seis meses após a infecção desafio com promastigotas de Leishmania (Leishmania amazonensis e nenhuma diferença estatística foi observada entre os grupos vacinados. Pode-se concluir que vacinas compostas por cepas isoladas de Leishmania protegem camundongos C57BL/10 contra, pelo menos, da infecção por L. (L. amazonensis.

  2. Phenotypic characterization and species-specific PCR of promising starter culture strains of Lactobacillus plantarum isolated from naturally fermented sausages Caracterização fenotípica e por PCR espécie-específica de cepas promissoras como cultivos iniciadores de Lactobacillus plantarum isolados de embutidos cárneos fermentados naturalmente

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    Maristela Cortez Sawitzki

    2007-09-01

    Full Text Available The purpose of the present work was to characterize promising starter culture strains of Lactobacillus plantarum isolated from naturally fermented artisanal sausage manufactured in the northwestern region of Rio Grande do Sul state, Brazil. From 127 isolates of homofermentative, Gram-positive and catalase-negative lactic acid bacteria, ten isolates were randomly selected and the phenotypic characterization and species-specific PCR were performed. Genomic DNA from each isolated strain and from the reference strains L. plantarum ATCC 8014 and L. pentosus ATCC 8041 were amplified using two pairs of L. plantarum species-specific primers (16/Lpl and LbP11/LbP12. The results of the phenotypic characterization and species-specific PCR indicated that five out of ten isolates were Lactobacillus plantarum.O objetivo do presente trabalho foi caracterizar cepas promissoras como cultivos iniciadores de Lactobacillus plantarum isoladas de embutidos cárneos fermentados naturalmente produzidos na região noroeste do Rio Grande do Sul, Brasil. Das 127 bactérias ácido láctica homofermentativas, Gram-positivo e catalase-negativo isoladas, dez foram aleatoriamente selecionadas e a caracterização fenotípica e a PCR espécie-específica foram realizadas. DNA genômico das cepas isoladas e das cepas de referência L. plantarum ATCC 8014 e L. pentosus ATCC 8041 foram amplificadas utilizando-se dois pares de iniciadores espécie-específicos para L. plantarum (16/Lpl e LbP11/LbP12. Os resultados da caracterização fenotípica e da PCR espécie-específica permitiram a identificação como Lactobacillus plantarum de cinco cepas das dez selecionadas.

  3. Resistência de Biomphalaria peregrina de Santa Rita do Sapucaí, Minas Gerais, a infecção com três cepas de Schistosoma mansoni Resistance of Biomphalaria peregrina from Santa Rita do Sapucaí, State of Minas Gerais, Brazil, to infection with strain of Schistosoma mansoni

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    Cecília Pereira de Souza

    1988-12-01

    Full Text Available Descendentes do planorbídeo Biomphalaria peregrina, coletados em Santa Rita do Sapucaí, Minas Gerais, Brasil, foram expostos a miracídios de três cepas de Schistosoma mansoni: "LE" de Belo Horizonte, MG; "SJ" de São José dos Campos, SP e "AL" do Estado de Alagoas. Dentre 300 exemplares expostos, nenhum se infectou com as três cepas do trematódeo. Por outro lado, 300 exemplares de B. glabrata, dos grupos de controle, apresentaram taxas de infecção de 61,1 a 95,3% com as três cepas do trematódeo. As taxas de mortalidade de B. peregrina e de B. glabrata foram de 20,0 e de 28,0%, respectivamente.The descendants of the planorbid snail Biomphalaria peregrina, collected in the region of Santa rita do Sapucaí, Minas Gerais, Brazil, were exposed to miracidia of three strains of Schistosoma mansoni: "LE" strain from Belo Horizonte, State of Minas Gerais; "SJ", strain from São José dos Campos, State of São Paulo and "AL" strain from State of Alagoas. Of 300 snails exposed to miracidia of the three strains, none was infected. On the other hand, 300 Biomphalaria glabrata of the control groups showed infection rates of 61.1 to 95.3% with three strains. The mortality rates of B. peregrina and B. glabrata were 20% and 28%, respectively.

  4. Secretion of an alkaline protease from a salt- tolerant and alkaliphilic, Streptomyces clavuligerus strain Mit-1 Secreção de uma protease alcalina por uma cepa halotolerante e alcalifílica de Streptomyces clavuligerus, Mit-1

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    Jignasha T. Thumar

    2007-12-01

    Full Text Available An alkaliphilic and salt- tolerant actinomycete, Streptomyces clavuligerus strain Mit-1, was isolated from Mithapur, the western coast of India. The organism was Gram-positive, having filamentous, long thread like structure. The sporulation started after two days of growth and the optimum level of alkaline protease (130 U/ml was produced during the early stationary phase. The strain could grow and produce protease with 0-10% NaCl (w/v, the optimum being 5% NaCl (w/v. Growth and protease production was optimum at pH 9 with substantial decline at neutral pH. Sucrose and gelatin were the best carbon and nitrogen sources respectively, whereas gelatin broth was the preferred medium for protease production. Mit-1 produced substantial protease with various amino acids, when employed as the sole nitrogen sources. Crude substrates, such as molasses, whey and wheat flour had significant effect on enzyme production. The results are quite valuable, as only few actinomycetes, particularly salt-tolerant alkaliphilic ones, have so far been explored for their enzymatic potential and process optimization.Uma cepa halotolerante e alcalifílica de Streptomyces clavuligerus, Mit-1, foi isolada em Mithapur, na costa oeste da Índia. Esse microrganismo é Gram positivo e apresenta estrutura filamentosa na forma de longas cordas. A esporulação iniciou após dois dias de cultivo e o nível ótimo de produção de protease alcalina (130 U/ml foi atingido no início da fase estacionária de crescimento. A cepa foi capaz de multiplicar com 0-10% NaCl (w/v, com um ótimo de 5% NaCl (w/v. O ótimo de crescimento e produção de protease foi atingido em pH 9, apresentando declínio substancial em pH neutro. Sacarose e gelatina foram as melhores fones de carbono e nitrogênio, respectivamente, enquanto o caldo gelatina foi o melhor meio para produção de protease. A cepa Mit-1 produziu bastante protease quando vários aminoácidos foram empregados como única fonte de

  5. EVALUACIÓN DEL CONTENIDO DE NUTRIENTES Y PRODUCCIÓN DE BIOMASA EN CEPAS DE LEVADURA COLOMBIANAS Y COMERCIALES EVALUATION OF THE NUTRIENT CONTENT AND BIOMASS PRODUCTION IN COLOMBIAN AND COMMERCIAL YEAST STRAINS

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    Nohora Patricia Manovacía Moreno

    2008-12-01

    Full Text Available En el presente estudio se evaluó la producción de biomasa, el contenido de algunos nutrientes (selenio, carbohidratos totales y proteína microbiana y el consumo de sustrato de cepas de levaduras comerciales y nativas pertenecientes al Banco de Germoplasma de la Nación Colombiana, manejado por la Corporación Colombiana de Investigación Agropecuaria, CORPOICA. Inicialmente se determinó el crecimiento de tres levaduras nativas seleccionadas al azar bajo diferentes condiciones de pH, temperatura y tiempo de fermentación usando un medio líquido de extracto de malta. Dentro de estas condiciones, las mejores respuestas se observaron a pH de 4,5, 25 °C y 24 horas de fermentación. Usando estas condiciones se evaluaron 100 accesiones de levaduras nativas y 4 comerciales por su producción de biomasa, contenido de selenio, carbohidratos totales y proteína microbiana y consumo de sustratos. De acuerdo con estas variables y un análisis de conglomerados fue posible agrupar las levaduras en grupos homogéneos. Hubo elevada variabilidad en la producción de biomasa entre las 104 cepas evaluadas, probablemente debido a la variabilidad biológica existente en la población estudiada. Los rendimientos de biomasa variaron entre 0,101 y 0,480 g de biomasa g-1 de azúcar consumido y las velocidades de producción de biomasa oscilaron entre 0,040 y 0,185 g L-1 h-1. El consumo promedio de nutrientes (g de nutrientes consumidos/ g de nutrientes disponibles fue de 91,6% en el caso de los carbohidratos y de 17,8% en el caso de la proteína. Se identificaron diez cepas de superior crecimiento y contenido de nutrientes, cuyo potencial prebiótico y probiótico será evaluado en futuros ensayos In vivo.In the present study biomass production and nutrient (selenium, total carbohydrate and microbial protein were evaluated in both commercial and native yeast isolates from the Colombian Germplasm Bank managed by the Colombian Corporation of Agricultural Research

  6. Modelación por homología de la proteína Luxs de Porphyromonas gingivalis cepa W83 Modelling by homology of Luxs protein in Porphyromonas gingivalis strain W83

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    A Díaz Caballero

    2012-12-01

    Full Text Available Antecedentes: En las proteínas no se logra siempre su cristalización, de buen tamaño y de buena calidad para someterla a difracción de rayos X. De tal manera que se abre un campo para el desarrollo de estudios teóricos moleculares y proteínicos, que permiten la representación de las moléculas en tres dimensiones, proporcionando una información espacial para estudiar la interacción entre ligandos y receptores macromoleculares. Materialesy Métodos: Estudio In silico, a partir del análisis de secuencias primarias de seis diferentes proteínas LuxS cristalizadas de diversas bacterias, se seleccionó la proteína 1J6X del Helicobacter pylori, por su similaridad con la secuencia de la proteína LuxS en Porphyromonas gingivalis (P. gingivalis cepa W83, para producir un modelo por homología de esta proteína, utilizando los programas Sybyl y MOE. Se realizó un acoplamiento con el ligando natural para evaluar la reproducibilidad del modelo en un ambiente biológico. Resultados: Se desarrolló el modelado de la proteína LuxS de P. gingivalis cepa W83, que permite el acercamiento a una estructura que se propone, por la interacción entre la proteína y su ligando natural. El modelo generado con recursos computacionales logró una correcta estructura molecular que aceptó la realización de diversos cálculos. El acoplamiento demostró una cavidad donde se logran diversas posiciones del ligando con buenos resultados. Conclusiones: Se obtuvo un modelo 3D para la proteína LuxS en la P. gingivalis cepa W83 validado por diferentes métodos computacionales con una adecuada reproducibilidad biológica por medio del acoplamiento molecular.Background: Crystallization is not always achieved for all proteins in a good size and a good quality for X-ray diffraction. So that condition opens a field for the development of theoretical molecular and protein studies allowing the representation of the molecules in 3D, providing spatial information to study

  7. Patrones de adherencia de cepas de Escherichia coli Difusamente adherente (DAEC provenientes de niños con y sin diarrea Adhesion patterns in diffusely adherent Escherichia coli (DAEC strains isolated from children With and without diarrhea

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    Maribel Riveros

    2011-03-01

    Full Text Available Introducción. Las E. coli de adherencia difusa (DAEC son el sexto grupo de E. coli diarrogénicas reconocidas. Su asociación con diarrea es controversial. No se conoce la variabilidad en los patrones de adherencia de cepas clínicas. Objetivos. Comparar los patrones de adherencia entre cepas aisladas de niños con y sin diarrea. Materiales y métodos. Se analizó 31 cepas DAEC, 25 de diarrea y 6 de niños asintomáticos (control aislados de un estudio de cohorte de niños menores de 12 meses en el cono sur de Lima. Las DAEC fueron identificadas por PCR (gen daaD. Se evaluó el patrón y grado de adherencia en cultivos de células HEp-2; la polimerización de actina se evaluó por la prueba de coloración de fluorescencia de actina (FAS; y la motilidad se evaluó por métodos convencionales microbiológicos. Resultados. El patrón de adherencia difusa se encontró en el 88% de muestras de diarrea y en el 100% de muestras control. La cantidad de bacterias adheridas por célula fue significativamente menor en las muestras de diarrea (pIntroduction. Diffusely adherent E. coli (DAEC is the sixth recognized group of diarrheagenic E. coli. However, its association with diarrhea remains controversial. Variability in the adherence patterns of clinical strains is unknown. Objectives. To compare the adherence patterns between strains isolated from children with and without diarrhea. Materials and methods. A total of 31 DAEC strains were analyzed, 25 from children with diarrhea and 6 from asymptomatic (control children, isolated from a cohort study of children under one year of age in the southern districts of Lima. DAEC were identified by PCR (daaD gene. The pattern and adherence score in HEp-2 cell culture were evaluated, Actin polimerization was determined by fluorescence actin staining (FAS and motility was evaluated by conventional microbiology methods. Results. Diffuse adherence pattern was found in 88% of diarrhea samples and in the total of

  8. Control of Botrytis cinerea in Eucalyptus globulus Mini-Cuttings Using Clonostachys and Trichoderma Strains Control de Botrytis cinerea en miniestacas de Eucalyptus globulus Utilizando Cepas de Clonostachys y Trichoderma

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    Salomé Zaldúa

    2010-12-01

    Full Text Available Botrytis cinerea Pers. ex Fr. causes the disease known as gray mold in more than 200 hosts. It is one of the most important pathogens in Chilean forest nurseries and Eucalyptus globulus Labill. is one of the most susceptible species, especially in vegetative reproduction systems. Clonostachys and Trichoderma strains were selected as potential biocontrol agents of gray mold in previous research by the authors. The objective of this study was to evaluate the effectiveness of antagonistic fungi to control B. cinerea in E. globulus mini-cuttings. Five fungi strains were tested and applied weekly, two Clonostachys and three Trichoderma (5 x 10(6 conidia mL-1. In addition, comparison treatments were also used: absolute control (water and fungicide application. The experiment was carried out under operational conditions to produce E. globulus mini-cuttings. The Clonostachys UDC-A10 and UDC-A11 strains reduce mini-cutting mortality caused by B. cinerea in 54 and 71%, respectively, and with effects similar to those achieved by fungicides. Clonostachys UDC-A11 reduces the disease progression rate with the same statistical results as fungicides. A negative effect of applying fungicides on rooting of the surviving mini-cuttings was also confirmed. These results demonstrate the effectiveness of Clonostachys as a control agent against gray mold disease in E. globulus mini-cuttings.Botrytis cinerea Pers. ex Fr. ocasiona la enfermedad conocida como moho gris en más de 200 hospederos. En Chile es uno de los patógenos más importantes en viveros forestales, siendo Eucalyptus globulus Labill. una de las especies más susceptibles, especialmente en los sistemas de reproducción vegetativa. En investigaciones previas, realizadas por los autores, se seleccionaron cepas de Clonostachys y Trichoderma como potenciales agentes de biocontrol del moho gris. El objetivo fue evaluar la eficacia de hongos antagonistas en el control de B. cinerea en mini-estacas de E

  9. Efecto del nitrógeno inorgánico (NO-3 sobre el crecimiento y la composición bioquímica de la microalga Scenedesmus sp. Cepa Laun 0001

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    Chaparro de Valencia Martha

    2004-12-01

    Full Text Available Se evaluó el efecto de seis concentraciones de nitrógeno en forma de nitrato, sobre el crecimiento y la composición bioquímica de la microalga cepa LAUN 0001 de Scenedesmus sp. (Chlorophyceae, aislada en el laboratorio de cultivo de microalgas de la Universidad Nacional de Colombia, en un
    lote de cultivos discontinuos, aireados permanentemente. Se estableció que en la razón de 3,5:1 de N:P, se obtiene el mejor rendimiento celular (18.280.000 + 2.820.000 células/ml con una tasa de crecimiento neta alta (2,9 a los siete días. La tasa de crecimiento instantánea no presentó diferencias significativas en los valores para cada tratamiento aplicado, pero se observó una tendencia general de incremento en los tratamientos con mayor concentración. La forma colonial de cuatro células por cenobio predominó en todos los tratamientos aplicados. La concentración de lípidos y carbohidratos se incrementó significativamente en los tratamientos con baja concentración
    de nitrógeno (61-77 pg/célula, mientras que en la  concentración de proteínas y clorofila no se observaron cambios significativos. La concentración de clorofila b fue levemente mayor con respecto a la clorofila a (2,65-3,42 contra 2,33-2,8 pg/célula; la concentración de carotenos fue baja en todos los tratamientos (0,62-0,76 pg/célula aumentando  significativamente en el tratamiento donde la razón de N:P es de 14:1 (1,03 pg/célula. Los valores altos registrados en los diferentes parámetros evaluados y el fácil manejo de la cepa, hacen de esta un modelo promisorio para la realización de estudios a nivel ecológico o biotecnológico.

  10. Screening of medicinal plants for antibacterial activities on Staphylococcus aureus strains isolated from bovine mastitis Screening de plantas medicinais com atividade antimicrobiana contra cepas de Staphylococcus aureus isoladas de mastite bovina

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    Marisa A. N. Diaz

    2010-11-01

    Full Text Available Staphylococcus aureus is the main causative agent of bovine mastitis. The activity of several extracts from ten medicinal plants traditionally used in Brazil as antiseptic was investigated against fifteen strains of Staphylococcus aureus isolated from animals with mastitis manifestation by the disc diffusion method and broth microdilution assay. The interference of the extracts on cell in the form of adherent colonies was also evaluated. MIC values ranged from 0.5 mg/mL to 1.0 mg/mL and biofilm inhibitory concentration (BIC were between 0.25 mg/mL and 0.8 mg/mL. Results revealed the potential of extracts of Senna macranthera, Artemisia absinthium, Cymbopogon nardus and Baccharis dracunculifolia as antibacterial agents against S. aureus strains isolated from bovine mastitis and support the possible use of these phytotherapic agents in the clinical management of the disease.Staphylococcus aureus é o principal agente causador de mastite bovina. A atividade de diversos extratos de dez plantas medicinais tradicionalmente usadas no Brasil como anti-sépticas foi investigada contra quinze cepas de Staphylococcus aureus isoladas de animais com manifestação de mastite pelo método de difusão em ágar e ensaio de microdiluição. A interferência dos extratos na célula bacteriana em forma de colônias aderidas também foi avaliada. Os valores de MIC variaram de 0.5 mg/mL a 1.0 mg/mL e a concentração inibitória de biofilme (BIC variou de 0.25 mg/mL a 0.8 mg/mL. Os resultados revelaram o potencial dos extratos de Senna macranthera, Artemisia absinthium, Cymbopogon nardus e Baccharis dracunculifolia como agentes antibacterianos contra cepas de S. aureus isolados de mastite bovina e suportam o possível uso destas plantas no manejo clínico da doença.

  11. Adaptación de una cepa compatible con Acidithiobacillus ferrooxidans sobre concentrados de calcopirita (CuFeS2, esfalerita (ZnS y galena (PbS

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    E Mejía

    2011-08-01

    Full Text Available Adaptation of a strain Acidithiobacillus ferrooxidans compatible on concentrates of chalcopyrite (CuFeS2, sphalerite (ZnS and galena (PbSRESUMENEn este estudio se evaluó la adaptación de una cepa compatible con Acidithiobacillus ferrooxidans a altas densidades de pulpa de calcopirita, esfalerita y galena, con dos distribuciones de tamaño de partícula, -200 y -325 serie Tyler de tamices. Los microorganismos fueron adaptados por la disminución gradual de la fuente principal de energía, sulfato ferroso, y el aumento en el contenido de mineral, para finalmente realizar un subcultivo sin la adición de fuente de energía externa. La realización de subcultivos en serie resultó ser una estrategia eficaz para la adaptación a altas densidades de pulpa de esfalerita, calcopirita y galena indicando que el protocolo empleado es adecuado. Los resultados muestran que la cepa compatible con Acidithiobacillus ferrooxidans es más resistente a altas concentraciones de esfalerita, seguido por calcopirita y finalmente por galena. El tamaño de partícula juega un papel fundamental en la adaptación de los microorganismos al mineral. Palabras clave: esfalerita, calcopirita, galena, adaptación, Acidithiobacillus ferrooxidans, biolixiviación. ABSTRACTIn this study the adaptation of Acidithiobacillus ferrooxidans-like to high concentrations of chalcopyrite, sphalerite and galena were evaluated with two mineral-particle sizes: 200 and 325 Tyler mesh. The strain was adapted using two simultaneous processes. The first one consisted in a gradual decreasing of the main energy source, ferrous sulphate. The second one consisted in a gradual increasing of the mineral content. Finally, a test was made without ferrous sulphate. The serial subculturing was found to be an efficient strategy to adapt Acidithiobacillus ferrooxidans-like to higher concentrations of chalcopyrite, sphalerite and galena. This indicates that a suitable protocol was employed. The results

  12. Haploid Plant Induction via in Vitro Gynogenesis and Plant Regeneration in Onion (Allium cepa L.)%离体雌核发育诱导洋葱单倍体与植株再生

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    刘冰江; 缪军; 霍雨猛; 杨妍妍; 徐坤; 吴雄

    2012-01-01

    以来自日本的3个中日照型洋葱(Allium cepa L.)杂交种的未开放花蕾为外植体材料,研究了2,4-D和6-BA浓度及配比对单倍体诱导培养的影响,以建立洋葱单倍体诱导技术体系。研究结果表明,含有1.5 mg · L^-1 2,4-D + 1.5 mg · L^-1 6-BA和2.0 mg · L^-1 2,4-D + 2.0 mg · L^-1 6-BA的B5培养基适于洋葱单倍体的诱导,诱导率最高达到4.00%。共获得了43枚雌核发育胚,雌核发育胚转移至不含激素的B5基本培养基中即可发育成完整植株,再生植株驯化移栽成活率达到100%。利用根尖染色体计数和流式细胞仪鉴定有42株是单倍体。%The flower buds of three intermediate-day hybrid cultivars of onion(Allium cepa L.)from Japanese seed company were cultured in vitro using B5 medium which supplied with 100 g · L-1 sucrose and 2,4-D and 6-BA. The suitable media for haploid induction of onion were B5 medium with 1.5 mg · L-1 2,4-D + 1.5 mg · L-1 6-BA and B5 medium with 2.0 mg · L-1 2,4-D + 2.0 mg · L-1 6-BA. The highest induction rate was 4.00%. Forty-three gynogenic embryos were obtained and each of them developed into the whole plant on the B5 medium with no any plant growth regulators. The regenerated plantlets were domesticated and transplanted in greenhouse. The survival rate was 100%. Ploidy analysis of the regenerants with chromosome counts of root tip cells and flow cytometry analysis of leaf tissue revealed that 42 of them are haploid.

  13. Avaliação de três cepas de vírus rábico, antigenicamente distintas, em camundongos: I - Estudo dos períodos de observação clínica Evaluation of three antigenically different rabies virus strains in mice: I - Study of the clinical observation periods

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    Pedro Manuel Leal Germano

    1988-10-01

    Full Text Available Estudou-se, comparativamente, o comportamento de três cepas de vírus rábico, duas de origem de cão, Jales e Nigéria, e uma de origem de morcego, DR 19, com perfis antigênicos do nucleocapside distintos. Estas cepas foram inoculadas por via intramuscular, na face interna da coxa, em dois grupos de camundongos, com 21 e 28 dias de idade. Os animais foram observados durante 30 dias, levando-se em consideração os períodos de observação clínica (incubação e duração da doença, determinando-se os coeficientes de mortalidade para cada grupo etário e para cada uma das cepas virais, bem como o título infectante de pool de cérebros de cada sub-grupo experimental. Os resultados obtidos permitiram constatar comportamento semelhante entre as cepas Jales e Nigéria, notadamente em relação aos períodos de observação clínica e mortalidade, para ambos os grupos etários, diferindo, todavia, quando comparados aos da cepa DR 19.A study was conducted to compare three rabies virus strains, two of them, Jales and Nigeria, isolated from dogs, and the other, DR 19, from vampire bats, with different nucleocapside antigenic variations. These strains were intramuscularly inoculated in the inside part of the thigh of 21 and 28 day-old mice. The animals were observed for 30 days, in accordance with the clinical observation periods (incubation and illness. Mortality rates by age and viral strain were recorded. The brain pooled infective title of each experimental subgroup was determined. The results showed that Jales and Nigeria strains were similar when clinical observation periods and mortality rates were analysed for both age groups. However, these results were different from to those obtained for the DR 19 strain.

  14. Metodologia de seleção de cepas para produção etodologia da ciclodextrina glicosiltransferase e para purificação da enzima - DOI: 10.4025/actascihealthsci.v29i1.133 Strains selection methodology for cyclodextrin glycosyltransferase production and enzyme purification - DOI: 10.4025/actascihealthsci.v29i1.133

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    Graciette Matioli

    2007-12-01

    Full Text Available As ciclodextrinas (CDs são maltooligossacarídeos, produzidas a partir do amido, pela enzima ciclodextrina glicosiltransferase (CGTase. Esta pesquisa teve por objetivo estabelecer metodologias de seleção de cepas para produção de CGTase e para purificação da enzima. Os microrganismos foram selecionados a partir de 53 análises de solos de cultura de amido, em placas contendo meio de cultivo específico, para seleção de cepas produtoras de CGTase. As enzimas foram obtidas com cultivo destes microrganismos em meio líquido. As atividades enzimáticas das CGTases foram determinadas pelos métodos espectrofotométricos e precipitação com tricloroetileno. A cepa isolada do solo de aveia foi a que apresentou maior atividade [0,1864 mol de -CD (min mL-1]. Esta cepa foi utilizada para a produção da enzima em escala laboratorial e purificação em cromatografia de afinidade bioespecífica. A cepa selecionada nesta pesquisa abre novas perspectivas para produção de enzima e CDs em escala industrial. Palavras-chave: ciclodextrina, glicosiltransferase, CGTase.Cyclodextrins (CDs are maltooligosaccharides produced from starch by cyclodextrin glycosyltransferase (CGTase enzyme. This research aimed at establishing method for strains selection for CGTase production and enzyme purification. The microorganisms were selected from 53 analyses of starch cultures soils on plates containing specific culture medium for strains selection that produce CGTase. The enzymes were obtained by culturing these microorganisms in liquid medium. The enzyme activity was determined with photospectrometric methods and precipitation with trichloroethylene. The strain isolated from oat soil was the one that showed the highest activity [0.1864 µmol of ß-CD (min mL-1]. This strain was used for enzyme production in laboratory scale and purification by biospecific affinity chromatography. The strain selected in this research opens new perspectives for enzymes

  15. Comparison of efficiency and reproductive aptitude indexes between a reference and field strains of the cattle tick Rhipicephalus (Boophilus microplus, in Sinaloa, Mexico Comparação dos índices de eficiência e aptidão reprodutiva entre uma cepa de referência e outra de campo do carrapato do gado, Rhipicephalus (Boophilus microplus, em Sinaloa, México

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    Soila Gaxiola-Camacho

    2009-12-01

    Full Text Available The objective of this work was to study the reproductive behavior of two strains of R. (B. microplus, one wild-caught (Native and one reference strain (Media Joya for two years, measuring the reproductive efficiency index (REI and reproductive aptitude index (RAI. Engorged ticks from each strain were collected monthly from February 2002 to February 2004. These were weighed and kept in the laboratory until egg-laying. Oogenic masses were individually weighed and incubated until larvae emergence. REI and RAI were calculated from each sample, grouping ticks by weight in 100 mg range classes. An analysis of variance and Duncan's multiple rank tests were carried out on the data (P O objetivo deste trabalho foi estudar a conduta reprodutiva de duas cepas de R. (B. microplus, uma coletada no campo (Nativa e outra de referência (Média Jóia, por dois anos, calculando o índice de eficiência reprodutiva (REI e o índice de aptidão reprodutiva (RAI. Foram coletados mensalmente carrapatos fêmeas engurgitadas de cada cepa no período de Fevereiro de 2002 a Fevereiro de 2004. Estas foram pesadas e conservadas no laboratório até ovipositar. As massas de ovos foram pesadas individualmente e incubadas até a eclosão das larvas. O REI e o RAI foram calculados para cada coleta, agrupando os carrapatos em classe de peso de 100 mg. Os dados foram submetidos a uma análise de variância e prova de classe múltipla de Duncan (P < 0,05. Foram calculados os coeficientes de correlação de Pearson (P < 0,01 para estimar a associação entre o peso dos carrapatos engurgitados e o peso e número de ovos postos e eclosionados. A cepa Nativa mostrou um peso ao engurgitamento mais alto do que a cepa Média Jóia. Os valores de REI e de RAI em ambas cepas foram similares em todos as classes de peso, mostrando tendência cuadrática na Média Jóia e linear-cuadrática na cepa Nativa (P < 0,05. Ambos os índices por classe de peso no engurgitamento foram sempre mais

  16. Analysis of proteins from membrane and soluble fractions of Giardia duodenalis trophozoites of two Brazilian axenic strains Análise de proteínas de frações de membranas e de frações solúveis de trofozoítos de duas cepas de Giardia duodenalis, isoladas e axenizadas no Brasil

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    Semíramis GUIMARÃES

    2002-10-01

    Full Text Available In the present study, we have analyzed by sodium docecyl sulphate - polyacrilamide gel electrophoresis (SDS-PAGE, immunoblotting and Concanavalin A blotting (Con A blotting proteins of membrane fractions and soluble fractions obtained from Giardia duodenalis trophozoites of two axenic strains isolated in Brazil from a symptomatic (BTU-11 and an asymptomatic patient (BTU-10, as compared to the reference strain Portland 1. Both Brazilian strains showed a complex and homogeneous electrophoretic pattern of proteins, but some differences could be observed. Several glycoproteins were detected, particularly the proteins of 81, 72, 59 kDa and the protein of 62 kDa in the membrane proteins and cytosol, respectively. Many antigenic components were revealed by anti-Giardia rabbit IgG antibodies in the immunoblotting analysis. Among these components, the membrane protein of 32 kDa and the cytosol protein of 30 kDa could be related to giardin, as previously demonstrated.Foi realizada a análise de algumas características bioquímicas e antigênicas de duas cepas axênicas de Giardia duodenalis, isoladas em Botucatu, a partir de cistos obtidos de paciente sintomático (BTU-11 e assintomático (BTU-10, tendo por referência a cepa padrão Portland 1 (P-1, isolada e axenizada nos Estados Unidos. Preparações contendo proteínas de membranas e proteínas solúveis (citosol de cada cepa foram empregadas na eletroforese das proteínas em gel de poliacrilamida (SDS-PAGE, na análise de glicoproteínas pela técnica de Con A blot e na análise antigênica pela técnica de "Immunoblotting". Na análise do perfil eletroforético os padrões de bandas de proteínas das cepas BTU-10 e BTU-11 foram complexos e na maior parte homogêneos; algumas diferenças foram detectadas entre as proteínas de membranas. Várias glicoproteínas foram demonstradas, destacando-se as de 81, 72, 59 kDa e a glicoproteína de 62 kDa, detectadas nas preparações de proteínas de membranas

  17. Atividade antibacteriana de óleos essenciais em cepas isoladas de infecção urinária Antibacterial activity of essential oils on microorganisms isolated from urinary tract infection

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    Rogério Santos Pereira

    2004-04-01

    Full Text Available A análise da atividade antibacteriana de óleos essenciais de ervas medicinais (Ocimum gratissimum, L., Cybopogum citratus (DC Stapf. e Salvia officinalis, L. foi verificada frente a 100 cepas de bactérias isoladas de indivíduos da comunidade com diagnóstico de infecção urinária. Os microrganismos foram semeados em ágar Muller Hinton e os extratos aplicados com replicador de Steers e incubados a 37°C por 24 horas. Verificou-se que Salvia officinalis, L. apresentou ação inibitória superior às outras ervas, tendo eficácia de 100% quando testadas em espécies de Klebsiella e Enterobacter, 96% em Escherichia coli, 83% contra Proteus mirabilis e 75% contra Morganella morganii.The antibacterial activity of essential oils extracted from medicinal plants (Ocimum gratissimum, L., Cybopogum citratus (DC Stapf., and Salvia officinalis, L. was assessed on bacterial strains derived from 100 urine samples. Samples were taken from subjects diagnosed with urinary tract infection living in the community. Microorganisms were plated on Müller Hinton agar. Plant extracts were applied using a Steers replicator and petri dishes were incubated at 37°C for 24 hours. Salvia officinalis, L. showed enhanced inhibitory activity compared to the other two herbs, with 100% efficiency against Klebsiella and Enterobacter species, 96% against Escherichia coli, 83% against Proteus mirabilis, and 75% against Morganella morganii.

  18. Influencia de la concentración de ácido glutámico y glicerol en la síntesis de meta bolitos antimicrobianos de Pseudomonas aeruginosa cepa PSS

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    Alina Frias

    2005-01-01

    Full Text Available En el presente trabajo se informa sobre la influencia significativa que ejerce la concentración de dos fuentes de carbono sobre la producción de metabolitos antimicrobianos empleando la cepa Pseudomonas aeruginosa PSS. Dichos metabolitos son especialmente atractivos para su uso en el control biológico de Alternaria alternatti. El cultivo se realizó a escala de zaranda empleando un diseño factorial 22 con glicerol y ácido glutámico como fuentes de carbono, a dos concentraciones (5 y 10 gL-1. Como variable respuesta se empleó el porcentaje de inhibición del crecimiento de Alternaria alternatti. Los mejores resultados en cuanto a la producción de metabolitos antimicrobianos fueron alcanzados en el medio con ácido glutámico a 5gL-1, urea y fosfato, al ser más económico y obtenerse rendimientos producto/sustrato de 30 %.

  19. Sélection de variétés d'oignon (Allium cepa L. adaptées au nord de la Côte d'Ivoire

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    Coulibaly, MY.

    2003-01-01

    Full Text Available Selection of Varieties Onion (Allium cepa L. Adapted to the North of Ivory Coast. Sixteen varieties of onion from the collection of the National Agronomical Research Center were evaluated on the basis of their performance in the North of Ivory Coast, during the agricultural season 1998- 1999. This evaluation was made in the presence of a local control, Violet de Galmi, at the station of production of onion seeds of the Rural Development Support National Agency. Varieties Rouge de Tana, RCS1903, RCS2211 and RCS2302 gave a higher rate of healthy bulbs (64.07% on average than the others. For the total yield, varieties RCS1903, RCS2211 and RCS2302 produced more (18.18 t/ha on average than Violet de Galmi (14.58 t/ha. The latter was more productive than Rouge de Tana (12.56 t/ha. However only the purple variety, Rouge de Tana had a high content of dry matter (20.86% and was good preserved with nearly 95% of healthy bulbs after 3 months of storage, like the local control. Significant correlations appeared between the various studied characters. The most significant correlation was observed between the date of harvest and the percentage of layering at 100 days (r= -0.858; and the rate of healthy bulbs after 3 months of storage and the content of dry matter (r= 0.847.

  20. Influência de sanificantes nas características microbiológicas, físicas e físico-químicas de cebola (Allium cepa L. minimamente processada Effect of sanitizers on the microbial, physical and physical-chemical characteristics of fresh-cut onions (Allium cepa L

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    Karla Michalsky Carvalho Beerli

    2004-02-01

    Full Text Available Objetivou-se com esta pesquisa avaliar a influência dos sanificantes peróxido de hidrogênio (H2O2 e dicloro isocianurato de sódio (NaDCC sobre a vida de prateleira da cebola (Allium cepa L. minimamente processada, com base no desenvolvimento da microbiota e características físicas e físico-químicas. As cebolas foram previamente lavadas, descascadas e fatiadas. Foram testados 6 tratamentos em 3 blocos casualizados. Os tratamentos foram: controle, H2O2 (2%, H2O2 (4%, H2O2 (6%, NaDCC (50ppm e NaDCC (100ppm. Após a sanificação, as cebolas foram embaladas e armazenadas durante 7 dias a 4ºC. A cada dia, uma bandeja de cada tratamento foi retirada e utilizada para coleta de amostras, para realização das seguintes análises: contagem padrão de microrganismos aeróbios mesófilos, contagem total de microrganismos aeróbios psicrotróficos, quantificação de fungos e leveduras, quantificação de coliformes a 35ºC e a 45ºC, sólidos solúveis totais (SST, pH, determinação da acidez total titulável (ATT, textura e perda de massa. Menores contagens de aeróbios mesófilos foram encontradas nos tratamentos com H2O2; todos os tratamentos, exceto o controle, foram eficientes para redução dos aeróbios psicrotróficos e coliformes a 35ºC; não foram encontrados coliformes a 45ºC em nenhum dos tratamentos; apenas os tratamentos com 4% e 6% de H2O2 reduziram os valores de fungos e leveduras; não houve diferenças entre os tratamentos para as análises de SST e perda de massa; foram obtidos maiores valores de pH para os tratamentos com NaDCC; menores valores de ATT foram encontrados nos tratamentos com H2O2 (4%, H2O2 (6% e NaDCC (50 ppm e maiores resultados de textura foram obtidos nos tratamentos com H2O2 (4% e H2O2 (6%. De acordo com as condições deste experimento, concluiu-se que o H2O2, nas concentrações de 4% e 6%, foi mais eficiente como sanificante para cebolas minimamente processadas do que o NaDCC; segundo os par

  1. Phenotypical and genotypical characterization of Bordetella pertussis strains isolated in São Paulo, Brazil, 1988-2002 Caracterização fenotípica e genética de cepas de Bordetella pertussis isoladas em São Paulo, Brasil, 1988-2002

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    Célia R. Gonçalves

    2007-04-01

    cepas de Bordetella pertussis isoladas no período 1988-2002 em São Paulo, Brasil. Todas as cepas foram submetidas à determinação do perfil de resistência à eritromicina, à sorotipagem e 56 cepas à eletroforese em campo pulsado (PFGE. Todas as cepas foram sensíveis à eritromicina e a maioria delas pertencia ao sorotipo 1,3. As 56 cepas foram classificadas em 11 perfis de PFGE com base nas diferenças no padrão de bandas. Embora mais de 60% das cepas tenham sido isoladas de crianças com menos de três meses de idade, cerca de 15% delas era de adolescentes/adultos evidenciando um aumento da incidência da coqueluche nesse grupo etário.

  2. 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

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    Liliana Muñoz M

    2009-01-01

    Full Text Available 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 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.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 strains

  3. Evaluación de la producción de ácidos orgánicos por Streptomyces spp. y solubilización de tres fuentes de fósforo por la cepa T3A

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    Gloria Carolina Prieto Correal

    2015-05-01

    Full Text Available  Título en ingles: Evaluation of organic acid production by Streptomyces spp. and solubilization of three phosphorus sources by strain T3A Título corto: Producción de ácidos orgánicos por Streptomyces spp.  y solubilización de fosfatos por la cepa T3A. Título corto en ingles: Organic acid production by Streptomyces spp. and solubilization by strain T3AResumen: Quince aislamientos de actinobacterias solubilizadoras de fósforo obtenidas a partir de suelos de los andes orientales colombianos fueron identificadas por sus características morfológicas y por la secuenciación del gen 16S ADNr. El análisis BLASTN de las 15 secuencias obtenidas mostró que los aislamientos pertenecían al género Streptomyces. Paralelamente, los aislamientos fueron sometidos a la detección de ácidos orgánicos, durante el proceso de solubilización de fósforo con la presencia mayoritaria de los ácidos oxálico, cítrico y glucónico. Dentro de las cepas evaluadas Streptomyces sp. T3A fue seleccionada para ser evaluada bajo diferentes fuentes de fósforo inorgánico debido a los resultados de evaluaciones cualitativas y cuantitativas realizadas previamente, en las cuales mostró una actividad solubilizadora de fósforo significativamente alta. Los resultados evidenciaron la capacidad de ésta actinobacteria para solubilizar diferentes fuentes de fosfatos insolubles con valores de 122 mgP·L-1 paraCa3(PO42, 14 mgP·L-1 para AlPO4 y 19,6 mgP·L-1 para roca fosfórica. También los ensayos revelaron que la actividad se mantiene en un rango de pH de 5 a 8 con las mismas fuentes de fosfatos evaluadas. Los resultados presentados contribuyen al avance en la caracterización de estas bacterias como promotoras de crecimiento vegetal con el fin de presentarlos como un recurso clave a nivel de biotecnología agrícola. Palabras clave: Streptomyces, Solubilización de fósforo, ácidos orgánicos, actinobacteria, HPLC. Abstrac: Fifteen isolates of Eastern

  4. Soil Management and Efficiency of Rhizobia Strains of Cowpea Vigna unguiculata (L. Walp. in the Tropics Manejo de Suelo y Eficiencia de Cepas de Rizobio de Frijol Vigna unguiculata (L. Walp. en los Trópicos

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    José Geraldo Donizetti dos Santos

    2011-12-01

    Full Text Available In the humid tropics, the largest obstacle to the implementation of sustainable farming systems is the reduced efficiency of nutrient use by crops. This study assesses the effectiveness of five selected rhizobia strains in symbiosis with cowpea (Vigna unguiculata (L. Walp., with the objective of replacing N fertilization in the predominant agricultural system used by smallholder farmers. The study was carried out in three adjacent areas with distinct agricultural uses: conventional tillage, itinerant agriculture, and a no-till system. The experimental design was in randomized complete blocks with four replicates and seven treatments: five rhizobia strains (BR3262, BR3267, BR3299, INPA3-11B, and UFLA 3-84 and two controls without inoculation (one without mineral N and another fertilized with 74 kg N ha-1. We measured the dry mass of 100 grains, nodules and shoots, as well as cowpea yields and calculated relative and absolute efficiency indices for dry biomass production of cowpea shoots. Agricultural uses affected the number and dry mass of the nodules and, consequently, the mass of the dry plant matter and bean yield. In terms of yield, there was a major difference between the conventional and the itinerant systems. Yield was around four times as high in the itinerant system (1009.9 kg ha-1 compared to 243.7 kg ha-1. Under conditions of cohesion-prone soils, the system of conventional tillage reduces the possibility of cultivation of a second harvest in the year even with inoculation or N fertilization.En los trópicos húmedos, el mayor obstáculo para la aplicación de sistemas de agricultura sostenible es la reducción de la eficiencia del uso de nutrientes por los cultivos. Este estudio evalúa la eficacia de cinco cepas de rizobios seleccionados en simbiosis con frijol (Vigna unguiculata (L. Walp., con el objetivo de sustituir la fertilización nitrogenada en el sistema de uso de suelo predominante utilizado por los pequeños agricultores

  5. Antifungal susceptibility of Candida albicans isolated from oral mucosa of patients with cancer Suscetibilidade de Candida albicans a antifúngicos: cepas isoladas da mucosa bucal de pacientes com câncer

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    Lino João da COSTA

    1999-07-01

    Full Text Available The increasing number of oral infections due to opportunistic fungi in immunocompromised patients, needs a new evaluation of the drugs in use. The susceptibility in vitro of Candida albicans strains from the oral mucosa of cancer patients to amphotericin B, ketoconazole, miconazole, fluconazole and itraconazole were evaluated. A dilution technique in YNB agar or subculture on Sabouraud agar was utilised for MIC or MFC determinations. With this methodology, the best fungicidal drug for C.albicans collected from the oral mucosa of 40 cancer patients, divided in two groups: one treated by radiotherapy and the other not, the best results were obtained with amphotericin B, presenting low values of MIC compared to azoles and MFC values. However it is important to take into consideration the utilisation in vivo of this polyenic antibiotic and the possible toxic levels necessary to achieve good results. The coexistence of other fungi and the local conditions must also be pondered with these patients, who are mostly undergoing radiotherapy. In order to achieve better results without undesirable consequences, higher levels of MIC are expected with the daily clinical use of new drugs.O crescente número de infecções fúngicas bucais em pacientes imunocomprometidos tem estimulado a pesquisa de drogas mais eficientes. Procuramos, assim, avaliar a suscetibilidade in vitro de cepas de Candida albicans de pacientes com câncer submetidos ou não a radioterapia frente às seguintes drogas: anfotericina B, cetoconazol, miconazol e itraconazol. A técnica de diluição em ágar YNB e o subcultivo em AS foram respectivamente utilizados para determinação da CIM (Concentração Inibitória Mínima e da CFM (Concentração Fungicida Mínima. Com esta metodologia, a droga que mostrou melhor atividade antifúngica para cepas de C. albicans isoladas de qualquer dos grupos de pacientes foi a anfotericina B, apresentando baixos valores de CIM em comparação aos az

  6. Suscetibilidade a antifúngicos de cepas de Candida albicans isoladas de pacientes com estomatite protética Susceptibility to antifungal drugs of Candida albicans strains isolated from patients with denture stomatitis

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    Jéssica Moreira BATISTA

    1999-12-01

    Full Text Available Pacientes portadores de próteses totais, apresentam, com freqüência a chamada estomatite protética, com a qual associa-se Candida albicans determinando a chamada candidíase eritematosa. Assim, procuramos avaliar a suscetibilidade dessa levedura a agentes antifúngicos. A suscetibilidade de dezenove cepas de Candida albicans isoladas de pacientes apresentando estomatite protética foi estudada frente a: um derivado poliênico representado, pela anfotericina B (AnB, e dois derivados azóicos, cetoconazol e miconazol. A atividade antifúngica foi estudada a partir da determinação da concentração inibitória mínima (CIM e da concentração fungicida mínima (CFM, pela técnica de diluição em ágar. Os resultados obtidos, mostraram baixos valores de CIMs e CFMs (mg/ml para a AnB frente a todas as leveduras. Para o miconazol e o cetoconazol, foram observadas CIMs invariavelmente £ 4,00 mg/ml; para as CFMs, foram obtidos valores ³ 16,00 mg/ml frente a maioria das cepas. Conclui-se que a AnB apresentou maior ação fungicida in vitro enquanto os azóis demonstraram ação fungistática mas não fungicida. Acreditamos que a pesquisa de novas drogas, principalmente de uso tópico ainda é necessária, a fim de se tratar, com sucesso, a candidíase eritematosa, comumente observada nas chamadas estomatites protéticas.Users of total prosthesis present in general a high frequency of the so called denture stomatitis, associated to erythematous candidiasis. So, we evaluated the susceptibility of oral yeast to three antifungal agents. Strains of Candida albicans isolated from patients with denture stomatitis were evaluated in relation to the susceptibility of the antifungal drugs as amphotericin B (polyenic derivatives, and azole agents as ketoconazole and miconazole. The antifungal activity was evaluated, and the minimal inhibitory concentration (MIC and minimal fungicide concentration (MFC were determined utilizing the agar dilution method. The

  7. First insights into the genetic diversity of Mycobacterium tuberculosis strains in Salvador, Bahia State, Brazil Primeiro ensaio sobre diversidade genética das cepas de Mycobacterium tuberculosis em Salvador, Bahia, Brasil

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    Aída Cristina do Nascimento Silva

    2011-09-01

    Full Text Available This study constitutes a first attempt to describe the genetic population structure of Mycobacterium tuberculosis circulating in Salvador, Bahia State, Brazil. A total of 56 confirmed cases of pulmonary tuberculosis, identified between March and June 2008, were analyzed using restriction fragment length polymorphism (IS6110-RFLP. The study population was characterized by a predominance of males (71.43% over 30 years of age (68.75%. Forty-one isolates were found to belong to a single pattern (73.2%, while 15 (26.7% were found in group patterns, forming six clusters. The higher level of diversity observed is much more suggestive of endogenous reactivation than recent transmission.Este é o primeiro estudo realizado na Bahia, Brasil, visando à descrição da estrutura da população genética circulante do Mycobacterium tuberculosis na cidade de Salvador. Um total de 56 casos confirmados de tuberculose pulmonar, identificados entre março e junho de 2008, foi analisado pelo método Restriction Fragment Lenght Polymorphism (IS6110-RFLP. A população de estudo foi caracterizada como a maioria do sexo masculino (71,43 %, idade acima de 30 anos (68,75%. Quarenta e um isolados (73,21% com padrão único, enquanto 15 (26,75% apresentaram padrões agrupáveis, formando seis clusters. A alta taxa de diversidade das cepas de M. tuberculosis observada é mais sugestiva de reativação endógena do que transmissão recente.

  8. Suplementación con selenio en vaquillas: Efecto sobre la respuesta inmune a las vacunas Brucella abortus cepa RB51 y toxoide tetánico Selenium suplementation in heifers: Effect on the immune response to Brucella abortus strain RB51 and tetanus toxoid vaccines

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    V Leyán; D Pesutic; G Schurig; F. WITTWER; P.A. CONTRERAS; J. KRUZE

    2005-01-01

    El trabajo tiene por objetivo evaluar el efecto de una suplementación con selenio (Se) sobre la respuesta inmune a las vacunas Toxoide tetánico y Brucella abortus cepa RB51 en vaquillas con un adecuado balance metabólico de selenio (GSH-Px >130 U/g Hb). Para ello se empelaron 32 vaquillas Friesian de 18 a 24 meses de edad, asignadas al azar a dos grupos de 16 animales; uno suplementado (Se-S) el día 0 con una dosis de selenato de bario (1 mg Se/kg, s.c.), permaneciendo el otro como control no...

  9. Secuenciación y clonación de los genes dihidrofolatoreductasa (dhfr) y dihidropteroatosintetasa (dhps) de la cepa RH y de 2 aislamientos de Toxoplasma gondii / Sequencing and cloning dihydrofolate reductase (dhfr) and dihydropteroate synthetase (dhps) genes of the RH reference strain and two isolates of Toxoplasma gondii

    OpenAIRE

    Cortés Cortés, Liliana Jazmín

    2012-01-01

    El presente trabajo tuvo por objetivo realizar la clonación y secuenciación de los genes dihidrofolatoreductasa (dhfr) y dihidropteroatosintetasa (dhps) de la cepa de referencia RH y de dos aislamientos de Toxoplasma gondii obtenidos a partir de líquido céfalo-raquídeo (LCR) de pacientes HIV positivos con toxoplasmosis cerebral. Se realizó la optimización de las técnicas de extracción del DNA parasitario y de la Reacción en Cadena de la Polimerasa (PCR), la secuenciación de los productos puri...

  10. Molecular characterization of severe and mild cases of influenza A (H1N1 2009 strain from Argentina Caracterización molecular de cepas de influenza A (H1N1 2009 de casos leves y graves de la Argentina

    Directory of Open Access Journals (Sweden)

    Elsa Baumeister

    2010-12-01

    Full Text Available While worldwide pandemic influenza A(H1N1 pdm case fatality rate (CFR was 0.4%, Argentina's was 4.5%. A total of 34 strains from mild and severe cases were analyzed. A full genome sequencing was carried out on 26 of these, and a partial sequencing on the remaining eight. We observed no evidence that the high CFR can be attributed to direct virus changes. No evidence of re-assortment, mutations associated with resistance to antiviral drugs, or genetic drift that might contribute to virulence was observed. Although the mutation D225G associated with severity in the latest reports from the Ukraine and Norway is not observed among the Argentine strains, an amino acid change in the area (S206T surrounding the HA receptor binding domain was observed, the same previously established worldwide.Mientras que la tasa de letalidad (CFR para (H1N1pdm en todo el mundo era del 0.4%, en la Argentina la mortalidad observada fue de 4.5%. La secuenciación del genoma completo de 26 cepas de virus argentinos de influenza A (H1N1pdm de casos leves y graves y de 8 cepas secuenciadas parcialmente no mostró evidencia de que la elevada tasa de letalidad se pueda atribuir directamente a cambios en el virus. No se encontraron hallazgos de recombinación, de mutaciones asociadas con la resistencia a los medicamentos antivirales ni de variaciones genéticas que puedan contribuir a la virulencia observada. Si bien la mutación D225G asociada con la gravedad, comunicada en informes procedentes de Ucrania y Noruega, no se ha encontrado en las cepas argentinas estudiadas, se ha observado un cambio aminoacídico en la región (S206T en torno al dominio del sitio de unión al receptor en la HA, el mismo hallado en cepas distribuidas alrededor del mundo.

  11. Immunoglobulin Fc receptors in clinical strains of Staphylococcus aureus do not confer resistance to Phagocytosis in an in vitro assay Los receptores Fc para inmunoglobulinas en cepas clínicas de Staphylococcus aureus no confieren resistencia a la fagocitosis in vitro

    Directory of Open Access Journals (Sweden)

    Benito VEGA

    1999-05-01

    Full Text Available Staphylococcus aureus binds Immunoglobulin G (IgG on its external surface due to the presence of specific receptors for the Fc domain of this immunoglobulin. This mechanism represents a kind of camouflage against phagocytic cells. In order to confirm that possibility an in vitro evaluation of the phagocytic activity of leukocytes polymorpho-nuclear (PMN against strains of Staphylococcus aureus was done, comparing 18 strains isolated from clinical samples and 16 from healthy individuals. The presence of Fc receptors was evaluated by haemagglutination (HA with erythrocytes group A after incubation of the strains with IgG anti blood group A. Phagocytosis of S. aureus was carried out by mixing live bacteria with a suspension of human PMN and incubating at 37 °C for 1 h; survivors were counted as colony forming units by plating. The strains from clinical specimens showed higher HA than those from healthy individuals (p = 0.01; but the former were killed more efficiently than the latter (80-90% and 40%, respectively. It is may be possible that S. aureus showed different behavior in vivo, where could express other virulence factors to prevent the action of phagocytes.Staphylococcus aureus liga inmunoglobulinas G (IgG a su superficie externa debido a la presencia de receptores para el dominio Fc de esas inmunoglobulinas. Este mecanismo representa una clase de camuflage contra células fagocíticas. Para confirmar tal posibilidad se realizó una evaluación in vitro de la actividad fagocítica de leucocitos polimorfonucleares (PMN contra cepas de Staphylococcus aureus, comparando 18 cepas aisladas de casos clínicos y 16 de individuos sanos. La presencia de receptores fue evaluada por hemaglutinación (HA con eritrocitos grupo A luego que las cepas fueron incubadas con IgG anti grupo sanguíneo A. La fagocitosis de S. aureus fue realizada mezclando células vivas con una suspensión de PMN e incubada a 37 °C por una hora; las bacterias sobrevivientes

  12. Relationship between plant nutrition and severity of damage caused by white rot desease on onion (Allium cepa Relación entre la nutrición mineral y la severidad del daño ocasionado por pudrición blanca en cebolla de bulbo

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    Piraneque G Nelson Virgilio

    2006-12-01

    Full Text Available

    In a comercial onion crop (Allium cepa located in Tibasosa, Boyacá, Colombia, the relationship between plant nutrition and severity of damage caused by white rot disease was studied. The soil was classified as sulfic endoamept. At 20 days before sowing (DAS and at 45, 90 and 120 days after sowing soil samples and esclerotium were taken plant tissue analysis at 45, 90 and 120 DAS was carried out. Also association among soil chemical parameters and plant percentage of damage was estudied. Results showed direct relationship among cooper content in soil (r=0.71, nitrogen in leaves (r=0.46 and magnesium in leaves (r=0.66 with percentage o damage caused by S. cepivorum. Calcium content in leaves (r=0.52, boron in leaves (r=-0.49 and esclerocios in soil Elg (r=0.56 were inversely proportional to percentage of damage. The treatment with the highest percentage of damage had higher contents of N, P and S in leaves and lower K, Ca, Mg, B, Mn, Cu and Zn.

    Key words: Allium cepa; Sclerotium cepivorum; plant nutrition.

    En un cultivo comercial de cebolla de bulbo (Allium cepa situado en el municipio de Tibasosa, Boyacá-Colombia, se recolectaron muestras de suelos (sulfic endoaquepts yesclerocios 20 días antes de la siembra, 45, 90 y 120 días después de la siembra (DDS; los análisis de tejidos se realizaron a los 45, 90 y 120 DDS. Se determinó la asociación entre parámetros químicos del suelo y de la planta con el porcentaje de daño. Se estableció asociación directa entre las variables, contenido de cobre en suelo Cu (r=0.71, nitrógeno foliar Nf(r=0.46 y magnesio foliar Mgf (r=0.66 con el porcentaje de daño causado por S. cepivorum. El contenido de calcio foliar Caf (r=-0.52, boro foliar Bf (r=-0.49 y esclerocios por gramo de suelo ES/g (r=-0.56 fueron inversamente proporcionales con el porcentaje de daño. El tratamiento con mayor porcentaje de daño presentó contenidos altos de N, P y S en tejidos y menores

  13. Identification of genes involved in the mutualistic colonization of the nematode Heterorhabditis bacteriophora by the bacterium Photorhabdus luminescens.

    LENUS (Irish Health Repository)

    Easom, Catherine A

    2010-01-01

    ABSTRACT: BACKGROUND: Photorhabdus are Gram negative entomopathogenic bacteria that also have a mutualistic association with nematodes from the family Heterorhabditis. An essential part of this symbiosis is the ability of the bacterium to colonize the gut of the freeliving form of the nematode called the infective juvenile (IJ). Although the colonization process (also called transmission) has been described phenomonologically very little is known about the underlying molecular mechanisms. Therefore, in this study, we were interested in identifying genes in Photorhabdus that are important for IJ colonization. RESULTS: In this work we genetically tagged P. luminescens TT01 with gfp and constructed a library containing over 3200 mutants using the suicide vector, pUT-Km2. Using a combination of in vitro symbiosis assays and fluorescent microscopy we screened this library for mutants that were affected in their ability to colonize the IJ i.e. with decreased transmission frequencies. In total 8 mutants were identified with transmission frequencies of <\\/= 30% compared to wild-type. These mutants were mapped to 6 different genetic loci; the pbgPE operon, galE, galU, proQ, asmA and hdfR. The pbgPE, galE and galU mutants were all predicted to be involved in LPS biosynthesis and, in support of this, we have shown that these mutants are avirulent and sensitive to the cationic antimicriobial peptide, polymyxin B. On the other hand the proQ, asmA and hdfR mutants were not affected in virulence and were either as resistant (proQ) or slightly more sensitive (asmA, hdfR) to polymyxin B than the wild-type (WT). CONCLUSIONS: This is the first report describing the outcome of a comprehensive screen looking for transmission mutants in Photorhabdus. In total 6 genetic loci were identified and we present evidence that all of these loci are involved in the assembly and\\/or maintenance of LPS and other factors associated with the cell surface. Interestingly several, but not all, of the transmission mutants identified were also avirulent suggesting that there is a significant, but not complete, genetic overlap between pathogenicity and mutualism. Therefore, this study highlights the importance of the cell surface in mediating the symbiotic and pathogenic interactions of Photorhabdus.

  14. Pesquisa de antigenos aglutinantes "major" 1, 2 e 3 em cepas de Bordetella pertussis, isoladas de crianças com coqueluche atendidas no Hospital de Isolamento Emílio Ribas de São Paulo, Brasil Determination of 1, 2 and 3 major antigens in Bordetella pertussis strains isolated from Brazilian children with whooping-cough

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    Sebastião Timo Iaria

    1977-09-01

    Full Text Available Em 30 cepas de Bordetella pertussis isoladas de crianças com coqueluche, atendidas no Hospital de Isolamento Emílio Ribas de São Paulo, foram pesquisados os antígenos aglutinantes ''major" 1, 2 e 3. Levando-se em conta a presença combinada dos três antígenos, as provas de soro-aglutinação rápida em lamina revelaram que 25 (83,3% cepas possuiam os fatores 1, 2 e 3, enquanto que 3 (10,0% e 2 (6,7% foram positivas, somente, para 1, 2 e 1, 3, respectivamente. Os resultados foram discutidos, considerando-se a importância deste antígeno no preparo de vacinas.The presence of major antigens, 1, 2 and 3 were determined in 30 strains of B. pertussis isolated from children with whooping-cough hospitalized at the Hospital Emílio Ribas, São Paulo Brazil. The method used was the slide-agglutination test. Tests showed that 25(83.3% of strains were positives for factors 1, 2 and 3. Factores 1 and 3 alone were present in 3 (10% of strains and 1 and 2 alone in 2 (6.7%.

  15. Cepas atenuadas de Babesia bovis e Babesia bigemina e de Anaplasma centrale como imunógenos no controle da tristeza parasitária bovina Attenuated strains of Babesia bovis and Babesia bigemina and of Anaplasma centrale as immunogens for tick borne disease control

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    Ana Maria Sastre Sacco

    2001-10-01

    Full Text Available Neste trabalho foram avaliadas cepas atenuadas de Babesia bovis e B. bigemina e Anaplasma centrale como imunógenos a serem utilizados no controle da Tristeza Parasitária Bovina. O processo de imunização demonstrou ser inócuo, imunogênico e eficiente, pelo menos no que diz respeito às babesias, pois protegeu os animais vacinados frente ao desafio com cepas heterólogas virulentas a campo, que provocou doença clínica e morte nos animais do grupo controle. O desafio a campo pelo Anaplasma marginale não se mostrou muito virulento ou patogênico, não sendo possível concluir que a imunização com A. centrale proteja os animais contra anaplasmose.Attenuated strains of Babesia bovis and B. bigemina and a strain of Anaplasma centrale were evaluated as immunogens against tick-borne disease. The immunization process was shown to be inocuous, immunogenic and efficient to protect cattle, at least against the babesias. Vaccinated animals proved to be protected when naturally challenged with heterologous and virulent strains, in contrast to control animals that showed clinical symptoms of the disease and had to be treated. The Anaplasma marginale challenge was not efficient since treatment was not necessary in the control animals, therefore it was not possible to conclude that immunization with A. centrale protected animals against anaplasmosis.

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

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    Alberto González Pedraza-Avilés

    2002-09-01

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

  17. Relación de la fijación de nitrógeno y la producción de auxinas en cepas de Gluconacetobacter diazotrophicus procedentes de diferentes cultivos

    Directory of Open Access Journals (Sweden)

    Marcia M. Rojas

    2009-08-01

    Full Text Available Relationships between nitrogen fixation and auxins production in Gluconacetobacter diazotrophicus strains from different crops ResumenSe determinó la capacidad de fijar nitrógeno mediante la actividad reductora de acetileno para 8 cepas de G. diazotrophicus aisladas de diferentes ecosistemas empleando el medio LGI-P. Además, se determinó la producción de auxinas a través del método de Salkowski y se analizó la influencia del aminoácido triptófano y del AIA en la actividad de la nitrogenasa. El triptófano, al igual que otros aminoácidos y las diferentes concentraciones de AIA, inhiben en distinta medida la actividad de la enzima solo parcialmente. Se demostró que las condiciones de nitrofijación no afectan la producción de AIA en esta bacteria. Esta relación entre ambas capacidades fisiológicas beneficiosas para los cultivos agrícolas pudiera tener gran importancia ya que pueden desarrollarse paralelamente, y potenciar la acción beneficiosa hacia la planta, basada en la dinitrofijación y la producción de auxinas estimuladoras del crecimiento vegetal.Palabras clave: Gluconacetobacter diazotrophicus; auxinas; fijación de nitrógeno. Abstract: The capacity to fix nitrogen of 8 strains of G. diazotrophicus from different ecosystems was determined by acetylene reduction assay using LGIP medium. Moreover, auxins production was determined by Salkowski’s method and the influence of triptophan and indoleacetic acid (IAA in the nitrogenase activity were analyzed. The triptophan as other aminoacids and different concentrations of IAA, inhibit at different levels the nitrogen fixation only partially. There were demonstrated that the nitrogen fixation conditions do not affect the auxins production of this bacteria. This relationship between both crop beneficial physiological capacities should be a great importance since they may be parallely developed, and enhance the beneficial action to the plant, based on dinitrogen fixation

  18. Evaluación del efecto de diferentes cepas de levadura (Montrachet, K1-V1116, EC-1118, 71B-1122 y IVC-GRE ® y clarificantes sobre los atributos sensoriales del vino de naranja criolla (Citrus sinensis

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    Rafael E Olivero

    2011-04-01

    Full Text Available Evaluation of effect of various strains of yeast (Montrachet, K1-V1116, EC-1118, 71B-1122 y IVC-GRE ® and clearer on the sensory attributes orange wine (Citrus sinensis RESUMEN En este trabajo se evaluó el efecto de diferentes cepas de levadura (Montrachet, K1-V1116, EC-1118, 71B-1122 y IVC-GRE ® sobre los atributos sensoriales del vino de naranja. Estos atributos fueron medidos utilizando la escala modificada de UC Davis. En una prueba de ordenamiento para determinar el mejor tratamiento de clarificación se determinó que la gelatina por sí sola no causa efecto sobre el atributo apariencia general, la combinación de la gelatina y la microfiltración tienen un efecto positivo sobre la apariencia del vino de naranja. Los cinco vinos tratados con diferentes levaduras presentaron diferencias significativas sobre la puntuación total, acidez total, sabor y calidad en general. En términos del efecto de las levaduras, la evaluación sensorial realizada a los vinos mostró que el de naranja con la levadura K1-V1116 fue el que sobresalió en términos de puntuación en los promedios de casi todos los atributos analizados por el panel sensorial.  Palabras clave: vino de naranja criolla, levaduras, clarificantes, atributos sensoriales.  ABSTRACT In this Wort was evaluated the effect of different types of strains of yeast (Montrachet, K1-V1116, EC-1118, 71B-1122 y IVC-GRE over the sensorial attributes of orange wines were also studied. These attributes were measured in a modified scale of UC Davis. By using an order test in order to know the best cleared treatment, it was determined that gelatin by itself does not cause any effect over the general quality attribute, but the combination of gelatin and microfiltration, cause a positive effect over the orange wine appearance. The five wines treated with different yeasts presented significant differences on individual scores, total acidy, flavor and general quality of the UC Davis scale. The

  19. Transmissão transovariana de Babesia bovis em Boophilus microplus: obtenção de cepa de carrapato livre de Babesia spp. Babesia bovis transovarian transmission in Boophilus microplus: obtention of a Babesia free tick strain

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    Tânia Regina Bettin dos Santos

    2000-06-01

    Full Text Available O presente trabalho objetivou o estudo de parte do ciclo da Babesia bovis no seu hospedeiro invertebrado, o carrapato Boophilus microplus. Analisou-se a capacidade de infeccção e transmissão transovariana de B. bovis em partenóginas de B. microplus, alimentadas em bovinos portadores e enfermos por esse protozoário. No 18º dia após a infestação, coletaram-se partenóginas diretamente do corpo dos bovinos e teleóginas após o desprendimento natural, a partir do 21º dia. Todos os grupos foram incubados a 27ºC e umidade relativa superior a 70%. No 5º dia após o início da postura, realizou-se o exame de hemolinfa a fim de diagnosticar a infecção dos ínstares por B. bovis. A ausência de infecção detectada no exame de hemolinfa foi confirmada posteriormente com o teste biológico, revelando que partenóginas não transmitem B. bovis transovarianamente. Esses resultados oferecem uma técnica simplificada para a obtenção de cepas de carrapatos livres de B. bovis.In this experiment part of the life cycle of Babesia bovis in its invertebrate host, the tick Boophilus microplus was studied. In order to evaluate the capacity of infection and transmission of B. bovis were collected semi-engorged females of B. microplus fed on carrier and ill bovines. In the 18th day after infestation, semi-engorged females were collected directly from bovine bodies and after 21st day engorged females dropped on the ground. All the collected groups were incubated at 27°C and relative humidity greater than 70%. At the 5th day of oviposition the diagnosis was made by direct examination of haemolymph smears. The biological test reveled that B. bovis transovarial transmission doesn't happer in semi-engorged females. The results offer a simple techique to obtain strains of ticks free of B. bovis.

  20. Pathogenicity of Entamoeba dispar under xenic and monoxenic cultivation compared to a virulent E. histolytica Patogenicidade de Entamoeba dispar em cultivo polixênico e monoxênico comparada a uma cepa virulenta de E. histolytica

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    Adriana Oliveira Costa

    2006-10-01

    Full Text Available Two xenic isolates and cloned cultures of Entamoeba dispar were submitted to monoxenization using Crithidia fasciculata as the associated organism. Growth in monoxenic cultivation and ability of xenic and monoxenic trophozoites to destroy VERO cells and produce lesions in hamster livers were compared to those of a virulent E. histolytica. Parental and cloned E. dispar under monoxenic cultivation showed a remarkable lower growth than the monoxenic E. histolytica and were avirulent in both in vivo and in vitro tests. When xenically cultured, trophozoites of E. dispar showed a moderate lytic activity against VERO cells (1.5 to 41.8% of destruction but caused severe hepatic lesions in hamsters as those caused by the virulent E. histolytica (29 to 100% in prevalence and 0.86 to 4.00 in lesion degree. Although E. dispar has not been associated with invasive disease in men, the ability of xenic trophozoites to produce prominent tissue damage in experimental conditions has indicated that some strains have a considerable pathogenic potential when in presence of bacteria.Dois isolados de Entamoeba dispar em cultivo polixênico e culturas clonadas deles obtidas foram submetidos à monoxenização utilizando Crithidia fasciculata como organismo associado. O crescimento em cultivo monoxênico dos isolados e clones, bem como sua capacidade de destruir células VERO (efeito citopático e de produzir lesões hepáticas em hamster foram comparados a uma cepa virulenta de E. histolytica. Os trofozoítos de E. dispar em cultivo monoxênico apresentaram um crescimento nitidamente menor que o de E. histolytica e foram avirulentos tanto no teste in vivo quanto in vitro. Entretanto, isolados e clones de E. dispar em cultivo polixênico exibiram uma atividade lítica moderada sobre as células VERO (1,5 to 41,8% de destruição e causaram lesões hepáticas em hamster (29 a 100% em prevalência e 0,86 a 4,00 no grau de lesão tão extensas quanto aquelas causadas pela

  1. Induction and Proliferation Conditions of Onion(Allium cepa L.) Embryogenic Callus%洋葱胚性愈伤组织的诱导及增殖条件的研究

    Institute of Scientific and Technical Information of China (English)

    代月; 吴雄; 朴炫春; 霍雨猛; 缪军; 廉美兰

    2012-01-01

    [目的]探讨洋葱离体培养的最佳条件,为建立其高频再生体系及转基因研究奠定技术基础.[方法]以洋葱(Allium cepa L.)种子为外植体,对洋葱愈伤组织的诱导、胚性愈伤组织获得及增殖的培养条件进行了初步研究.[结果]不同培养基种类对愈伤组织的诱导有影响,BDS优于MS和B5培养基;当培养基中2,4-D浓度为0.5 mg,/L时种子出愈率最高;适当降低生长素浓度,添加分裂素BA能够促进胚性愈伤组织的发生,且无分化现象产生,胚性愈伤组织诱导最佳培养基为BDS+2,4-D 0.25 mg/L+BA 2.0 mg/L,增殖最佳培养基为BDS+2,4-D O.25 mg/L+BA 1.0 mg/L.[结论]该试验建立的基因转化受体系统为洋葱基因转化奠定了良好基础.%[Objective] To explore the best conditions for the in vitro culture of onion, so as to lay technical foundation for its trangenic research and the establishment of high frequency regeneration system. [ Method] With the onion seeds as explants, the induction and proliferation conditions of onion (Alliiim r.epa L. ) callus and embryogenic callus were preliminarily studied. [ Result] The types of callus produced certain impact on the induction of callus, BDS was better than MS and B5; the callus rate was the highest at the concentrations of 0. 5 mg/L 2,4-D; the appropriate reduction of auxin concentration and addition of cytokinin BA could promote the induction of enbryogenic callus without differentiation, the best embryogenic callus induction medium was BDS +2,4-D 0. 25 mg/L + BA 2.0 mg/L and the best proliferation medium was BDS + 2,4-D 0.25 mg/L + BA 1.0 mg/L. [Conclusion] Hie transgenic receptor system established in this experiment lays good foundation for the genetic transformation of onion.

  2. Análisis de las polihidroxialcanoato sintasas (PhaC1 y PhaC2 en una cepa de Pseudomonas fluorescens IBUN S1602, aislada en suelos colombianos

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    Julieth Serrano Riaño

    2012-06-01

    Full Text Available Normal 0 21 false false false ES-CO X-NONE X-NONE MicrosoftInternetExplorer4 Título en ingles: Analysis of polyhydroxyalkanoate synthases (PhaC1 and PhaC2 in a strain of Pseudomonas fluorescens   IBUN S1602 isolated from Colombian soil. Resumen La cepa Pseudomonas fluorescens IBUN S1602 conforma el grupo de aislamientos provenientes de suelos colombianos de caña de azúcar, que acumula polihidrioxialcanoato (PHA, fue seleccionada como promisoria para escalamiento comercial por tener afinidad por sustratos alternativos y económicos como el glicerol, aceites usados, suero de leche, entre otros. Dada la importancia de la enzima sintasa en la síntesis de los PHAs, en el presente trabajo se realizó el análisis molecular de los genes phaC1 y phaC2 que codifican las enzimas sintasas tipo II (PhaC1 y PhaC2. Para la obtención de los amplímeros requeridos en la secuenciación, se utilizó la técnica de PCR bajo condiciones estandarizadas para iniciadores diseñados reportados en las bases de datos. Se identificaron dos fragmentos de 1680 pb y 1683 pb correspondientes a  phaC1 y phaC2. El análisis comparativo de las secuencias proteicas resultantes de estos genes demuestra que la sintasa  IBUN S1602 contiene la región α/β hidrolasa y 8 residuos de aminoácidos conservados, que son características de las sintasas examinadas a nivel mundial. Se analizó la estructura enzimática a nivel primario y se predijo la secundaria. Se concluyó que  las sintasas de la cepa Pseudomonas fluorescens IBUN S1602 presentan alta homología con las sintasas tipo II  que se reportan para Pseudomonas. Los resultados obtenidos contribuyen al entendimiento básico de la biosíntesis de PHA,  la cual permitirá, en un futuro, el aumento de la calidad de PHA debida a la modulación del nivel de sintasa que se exprese en un organismo recombinante, con el fin de variar el peso molecular del biopolímero, propiedad esencial en el estudio de aplicaciones

  3. Detection of different Staphylococcus aureus strains in bovine milk from subclinical mastitis using PCR and routine techniques Detecção de diferentes cepas de Staphylococcus aureus de mastite bovina subclínica através da técnica de PCR e técnicas tradicionais

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    Olney Vieira-da-Motta

    2001-03-01

    Full Text Available Contamination of fresh milk with Staphylococcus aureus was assessed comparatively through routine phenotypic (coagulase tube test and coagulase slide test and genotypic (PCR screening of 128 S. aureus strains isolated from 555 milk samples. These samples were collected from 362 cows with subclinical mastitis, hosted in different dairy herds at various locations of the Northern and Northeastern rural areas of the State of Rio de Janeiro, 39.7% of which were CMT-positive. All S. aureus isolates tested positive for the presence of the coagulase gene by PCR and the isolates could be grouped into four distinct classes according to the size of the PCR product. The strains also yielded variable results when assayed with coagulase test. Taken together, these data indicate the existence of extensive polymorphism at the coagulase gene locus in the genus Staphylococcus and exemplifies the extent of molecular and phenotypic heterogeneity associated with the strains circulating in rural herds.Quinhentas e cinqüenta e cinco amostras de leite, provenientes de 362 vacas com mastite subclínica em diferentes propriedades rurais do Estado do Rio de Janeiro, Brasil, de 1995 a 1997, foram submetidas ao teste "Califórnia Mastitis Test" (CMT. 39,7% das amostras foram positivas, das quais foram isoladas 128 cepas de Staphylococcus aureus. Todas as cepas isoladas foram positivas para o gene da coagulase utilizando a técnica de PCR, todavia, resultados de coagulase através das técnicas em tubo e "coagulase slide test" foram variáveis. Após a amplificação do gen de coagulase através da técnica de PCR utilizando iniciadores específicos para o referido gen, fragmentos com diferentes pesos moleculares foram vistos através de análise em gel de agarose, sugerindo a ocorrência de polimorfismo genético. O estudo também sugere a ocorrência de diferentes cepas da bactéria atuando nos rebanhos leiteiros causando mastite bovina.

  4. Detecção de cepas patogênicas pela PCR multiplex e avaliação da sensibilidade a antimicrobianos de Escherichia coli isoladas de leitões diarréicos Detection of pathogenic strains by multiplex PCR and antimicrobial sensitivity of Escherichia coli isolated from piglets

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    N.R. Macêdo

    2007-10-01

    Full Text Available Avaliou-se a freqüência dos genes de fímbrias (K88, K99, 987P, F18 e F41 e toxinas (LT, Stb, StaP e Stx2e de cepas de E. coli isoladas de leitões com diarréia usando a técnica de PCR multiplex com primers específicos para esses genes, e estudou-se o padrão de sensibilidade das cepas patogênicas pelo método de difusão em disco ao florfenicol, ceftiofur sódico, colistina, fosfomicina, neomicina, norfloxacina, sulfa + trimetoprim, doxiciclina, tetraciclina e lincomicina. Foram utilizadas 144 amostras de E.coli isoladas de leitões com diarréia, provenientes de granjas localizadas no estado de Minas Gerais. Dessas, 42 (29,2% foram positivas para pelo menos um dos fatores de virulência testados. Dentre essas 42 amostras, 23 (54,8% apresentaram genes de fímbria e toxina, sete (16,6% apresentaram somente genes de toxinas e 12 (28,6% amostras somente genes de fímbria. O resultado do teste de sensibilidade aos antimicrobianos demonstrou que o florfenicol (89,5 % e o ceftiofur sódico (84,2% foram as drogas de melhor eficácia in vitro sobre cepas de E. coli com fatores de virulência.The frequency of virulence determinants genes for fimbrial adhesions (K88, K99, 987P, F18 and F41 and toxins (LT, Stb, StaP and Stx2e in E. coli strains isolated from diarrheic piglets using the multiplex polymerase chain reaction assay with specific primers for these genes was studied. The antimicrobial sensitivity pattern of pathogenic isolates for florfenicol, sodium ceftiofur, colistin, fosfomycin, neomycin, norfloxacin, sulfa + trimetoprim, doxycycline, tetracycline and lincomycin was also tested using the disk diffusion method. E. coli were isolated from 144 diarrheic piglets from farms in the state of Minas Gerais. Forty-two out of 144 studied samples (29.2% were positive for at least one tested virulence factor. Out of these 42, 23 samples (54.8% contained fimbria and toxin genes, seven (16.6% samples had genes for toxins only and 12 (28.6% samples

  5. Comparison of predicted binders in Rhipicephalus (Boophilus microplus intestine protein variants BM86 Campo Grande strain, BM86 and BM95 Comparação da previsão de ligação das variantes de proteína de intestino de Rhipicephalus (Boophilus microplus Bm86 cepa Campo Grande, Bm86 e Bm95

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    Renato Andreotti

    2008-06-01

    Full Text Available This paper reports the sequence analysis of Bm86 Campo Grande strain comparing it with Bm86 and Bm95 antigens from the preparations TickGardPLUS and GavacTM, respectively. The PCR product was cloned into pMOSBlue and sequenced. The secondary structure prediction tool PSIPRED was used to calculate alpha helices and beta strand contents of the predicted polypeptide. The hydrophobicity profile was calculated using the algorithms from the Hopp and Woods method, in addition to identification of potential MHC class-I binding regions in the antigens. Pair-wise alignment revealed that the similarity between Bm86 Campo Grande strain and Bm86 is 0.2% higher than that between Bm86 Campo Grande strain and Bm95 antigens. The identities were 96.5% and 96.3% respectively. Major suggestive differences in hydrophobicity were predicted among the sequences in two specific regions.O objetivo deste estudo foi analisar a seqüência de Bm86 cepa Campo Grande comparando-a com os antígenos Bm86 e Bm95 das preparações TickGardPLUS e GavacTM, respectivamente. O produto de PCR foi clonado em PMOSBlue e seqüenciado. Para calcular os conteúdos de alfa-hélice e fita beta do polipeptídio previsto, foi utilizada a ferramenta de prognóstico de estrutura secundária PSIPRED. O perfil de hidrofobicidade foi calculado usando os algoritmos de Hopp e Woods, além da identificação das possíveis regiões de ligação com MHC classe I nos antígenos. O alinhamento "pair-wise" revelou que a similaridade entre Bm86 cepa Campo Grande e Bm86 é 0,2% maior que aquela entre Bm86 cepa Campo Grande e Bm95. As identidades foram de 96,5% e 96,3%, respectivamente. Com relação à hidrofobicidade, os resultados sugerem que a maior diferença entre as seqüências está localizada em duas regiões específicas.

  6. Cyclodextrin glycosyltransferase production by new Bacillus sp. strains isolated from brazilian soil Produção de ciclodextrina glicosiltransferase por novas cepas de Bacillus sp. isoladas de solo brasileiro

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    Vivian Menocci

    2008-12-01

    lado, o isolado de BACNC-1 apresentou atividade específica 2,4x10-3 U/mg prot quando cultivado em pH 7,0 acrescido de 1% de NaCl, e em pH 10,0 sua atividade específica foi de 3,4x10-3 U/mg prot sem adição de NaCl. Também foi demonstrada neste trabalho que ciclodextrinas são formadas durante o processo fermentativo, e que a precipitação com acetona ou liofilização seguida de diálise foram eficientes na remoção destas CDs, eliminando sua interferência nos ensaios enzimáticos. A enzima produzida pela cepa BACAR foi purificada parcialmente liberando b-CD como produto da reação.

  7. Qualidade da silagem de cana-de-açúcar inoculada com uma cepa de Lactobacillus buchneri = Effect of addition of a bacteria isolated from sugarcane silage on the quality of the silage

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    Michele Simile Silva

    2008-10-01

    Full Text Available Objetivou-se avaliar o efeito de um inoculante bacteriano sobre as características químicas e microbiológicas da silagem de cana-de-açúcar. Os tratamentos foram silagem sem inoculante e silagem inoculada com uma cepa identificada como sendo da espécie Lactobacillus buchneri. Para a avaliação do perfil de fermentação das silagens, os silos experimentais de PVC foram abertos com 0, 10, 32 e 70 dias de fermentação; retiraram-se amostras para determinação dos teores de matéria seca (MS, proteína bruta (PB, fibra em detergente neutro (FDN, fibra em detergente ácido (FDA e hemicelulose, para avaliação da população de bactérias do ácido lático (BAL, de leveduras e para determinação dos valores de pH. Foi observada redução nos teores de MS de 33,02 para 25,99%, e aumento nos teores de FDN e FDA de 48,78 para 60,14% e de 28,42 para 38,61%, respectivamente, com a fermentação. A população de BAL foi maior para a silagem inoculada, e a população média de leveduras e os valores de pH foram menores. Recomenda-se a aplicação de Lactobacillus buchneri (4 log ufc g-1 de forragem na ensilagem da cana-de-açúcar.Evaluating the effect of an inoculant containing a strain isolated from sugarcane silage on the chemical and microbiological characteristics of the silage of this forage was aimed. The treatments were silage without an inoculant and the strain identified as being of the species Lactobacillus buchneri. The forage was compacted in PVC silos. For the evaluation of the fermentation profile of the silages, the silos were opened with 0, 10, 32 and 70 days of fermentation and samples removed for determination of the content of dry matter (DM, crude protein (CP, neutral detergent fiber (NDF, acid detergent fiber (ADF and hemicellulose and for evaluation of the population of lactic acid bacteria (LAB and of yeasts for determination of pH. A reduction of DM contents from 33.02 to 25.99% and increased contents of NDF and ADF from

  8. EFEITO DA RADIAÇÃO GAMA NA SOBREVIVÊNCIA DA LEVEDURA Saccharomyces cerevisiae (cepa M-300-A EM MOSTO DE MEL DE CANA-DE-AÇÚCAR

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    A.R. ALCARDE

    1997-09-01

    Full Text Available No presente trabalho foi estudado o efeito da radiação gama na sobrevivência da levedura Saccharomyces cerevisiae em mosto de melaço de cana-de-açúcar. O melaço a 65o Brix foi diluído a 11o Brix e inoculado com a levedura Saccharomyces cerevisiae (cepa M-300-A. As amostras foram irradiadas com doses de 1,0; 2,0; 3,0; 4,0; 5,0 e 6,0 kGy (Cobalto-60, a uma taxa de 1,703 kGy/h. As amostras foram armazenadas a 4, 18 e 32oC por 7 e 14 dias. A radiação gama se mostrou efetiva em controlar a proliferação da levedura no mosto logo após a sua irradiação, sendo que nas doses de 5,0 e 6,0 kGy não foi observada nenhuma unidade formadora de colônia da levedura. As amostras armazenadas por 7 e 14 dias a 4oC não apresentaram capacidade de proliferação da levedura, mostando resultados semelhantes àqueles obtidos logo após a irradiação do mosto. Nenhuma dose de radiação foi efetiva, porém no controle da proliferação da levedura nas amostras armazenadas por 7 e 14 dias a 18 e 32oC. A dose D10 (dose para reduzir a população a um décimo determinada para a levedura Saccharomyces cerevisiae no mosto foi de 0,775 kGy.The effect of gamma radiation was studied on yeast survival in sugar-cane molasses. Molasses (65o Brix was diluted to 11o Brix and inoculated with Saccharomyces cerevisiae (strain M-300-A yeast. The samples were irradiated with doses of 1.0; 2.0; 3.0; 4.0, 5.0 and 6.0 kGy (Cobalt-60, at a 1.703 kGy/h rate. The samples were stored at 4, 18 and 32oC during 7 and 14 day periods. No unit-forming colony was detected at the doses of 5.0 and 6.0 kGy, immediately after irradiation. Gamma radiation was effective to control yeast proliferation on sugar-cane molasses right after irradiation. The samples stored at 4oC for periods of 7 and 14 day did not show yeast proliferation, however none of the radiation doses was effective in controlling yeast proliferation of samples stored at 18 and 32oC for periods of 7 and 14 days. The D10

  9. Modulación de la fisiología gastrointestinal mediante cepas probióticas de Lactobacillus casei y Bifidobacterium bifidum Modulation of gastrointestinal physiology through probiotic strains of Lactobacillus casei and Bifidobacterium bifidum

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    J. Barrenetxe

    2006-12-01

    Full Text Available En el contexto de la alimentación y la promoción de la salud se sitúan los productos denominados alimentos funcionales que tienen diversos efectos beneficiosos en el organismo, además de los meramente nutricionales. Dentro de estos alimentos funcionales, entre otros, podemos distinguir entre compuestos probióticos y prebióticos. Los microorganismos más utilizados en alimentos probióticos pertenecen a los géneros Lactobacillus y Bifidobacterium. En el presente trabajo se ha estudiado el efecto de dietas suplementadas con Lactobacillus casei o Bifidobacterium bifidum en el desarrollo animal y en especial sobre la función intestinal, centrada en su actividad immunitaria, digestiva y absortiva de animales en crecimiento. Las cepas bacterianas utilizadas modifican la actividad del intestino delgado de los ratones sanos, afectando significativamente a su actividad enzimática (sacarasa, maltasa y aminopeptidasa y a la captación de nutrientes (galactosa y glicilsarcosina, así como a la actividad inmune intestinal (mayor número de placas de Peyer. Sin embargo, estos efectos no parecen perturbar el desarrollo de los animales en crecimiento ya que no se aprecian diferencias significativas en su peso corporal ni en sus parámetros sanguíneos. Estos resultados ponen de manifiesto los posibles efectos beneficiosos en la fisiología intestinal y contribuyen al conocimiento de los posibles mecanismos de acción de los probióticos, que se pudieran utilizar en el tratamiento preventivo de diferentes patologías relacionadas con el aparato digestivo.The products called functional foods, which besides being merely nutritional have different beneficial effects on the organism, are situated in the context of diet and health promotion. Amongst these functional foods we can distinguish, amongst others, between probiotic and prebiotic compounds. The micro-organisms most widely used in probiotic foods belong to the Lactobacillus and Bifidobacteriumtypes

  10. Variabilidad de cepas de Hirsutella thompsonii, a partir de ácaros fitófagos en tres sistemas terrestres del estado de Colima, México Variability of Hirsutella thompsonii strains, isolated from phytophagous mites from three terrestrial systems in the State of Colima, México

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    José Luis Rosas-Acevedo

    2006-06-01

    Full Text Available Entre 1999 y 2004 se obtuvieron diez cepas del hongo Hirsutella thompsonii Fisher, a partir de ácaros infectados, en 9 localidades de 3 de los 11 sistemas terrestres que tiene el estado de Colima, México: Llanura Costera de Tecomán, Llanura Costera de Cuyutlán y Valle del río Armería. De las 10 cepas, 5 pertenecen a la variedad thompsonii que es de crecimiento micelial mullido, ligeramente elevado, de color gris a gris verdoso, y 5 a la variedad sinematosa Samson, McCoy y O'Donnell, de apariencia plana y coloración blanco a amarillo. Los hospedantes fueron araña roja (Tetranychus urticae Koch, eriófidos (Aceria guerreronis Keifer y Phyllocoptruta oleivora Ashmead y brevipálpidos (Brevipalpus phoenicis Geijkes sobre cítricos como hospedero de 8 de los 10 aislamientos. De ellos, sólo la cepa HtM130 de H. thompsonii var. thompsonii presentó formación de exudados en la fase esporulativa, característica que le da mayor potencial de manejo en estrategias para el control de ácaros fitopatógenos. El tipo de crecimiento y la coloración de las cepas no se correlacionan con el sistema terrestre donde se encontraron, ni con las condiciones climáticas imperantes en ellos. La presente contribución demuestra la importancia de valorar la presencia de enemigos naturales autóctonos para garantizar un mejor establecimiento bajo las condiciones agroclimáticas de la región donde se pretenda utilizarlos, y antes de introducir microorganismos comerciales o aislamientos de otros sitios para no afectar los sistemas naturales de regulación.Between 1999 and 2004, ten strains of the fungus Hirsutella thompsonii Fisher were isolated from infected acari, in 9 localities of 3 of the 11 terrestrial systems found in the state of Colima, Mexico: Coastal Plain of Tecomán, Coastal Plain of Cuyutlán and Valley of the Armería river. Of the 10 strains, 5 belong to var. thompsonii, whose growth is fluffed mycelial, slightly tall, gray to greenish gray, and 5

  11. Técnicas diagnósticas de referencia para el análisis de marcadores de virulencia del virus pseudorrabia, cepa RC/79: ensayos preliminares Referential diagnostic techniques to analyze virulence markers of pseudorabies virus RC/79 strain: preliminary assays

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    L.I. SABINI

    1997-01-01

    Full Text Available En nuestro laboratorio hemos estandarizado los métodos de inmunoperoxidasa e inmunofluores-cencia indirecta para la detección del virus de la enfermedad de Aujeszky en cultivos de células Vero, utilizando como modelo la cepa viral RC/79. Hubo una fuerte correlación entre los resultados logrados por ambas técnicas, las que evidenciaron ser altamente específicas para la identificación del virus y permitieron una precisa localización de los antígenos virales en las células infectadas. La aparición de células multinucleadas o sincitios con marcada reacción en la región nuclear a las 16 horas p.i. indicó que la cepa RC/79 es fuertemente virulenta. Esta aseveración fue corroborada por los ensayos de infección experimental en conejos. El carácter virulento de la cepa se evidenció por un intenso prurito en la zona de inoculación, con la aparición de una lesión rezumante serosanguinolenta entre las 6 y 24 horas previas a la muerte. La misma aconteció en tiempo promedio, a las 62 y 120 horas p.i., dependiendo de la dosis viral inyectada. En todos los casos la tasa de mortalidad fue del 100%, aun trabajando con cantidades menores de virus (102 UFP, indicando ausencia de dosis-respuesta. Los métodos empleados fueron útiles como marcadores de virulencia para la cepa RC/79 y se constituyen en herramientas indispensables para el diagnóstico de la enfermedad de Aujeszky, disponibles en nuestro laboratorio y posibles de contemplar por las autoridades nacionales cuando establezcan un plan sanitario para esta patología.The indirect immunoperoxidase and immunofluorescence methods were standardized for the detection of Aujeszky's disease virus in Vero cell cultures, using as a model the RC/79 strain virus." There was a strong correlation in the results obtained by both methods. The results proved to be highly specific for the identification of the virus and allowed a precise localization of the viral antigen in infected cells. The presence

  12. Molecular characterization and evaluation of antimicrobial susceptibility of enteropathogenic E. coli (EPEC isolated from minas soft cheese Caracterização molecular e avaliação da suscetibilidade antimicrobiana de cepas enteropatogenicas de E. coli (EPEC, isoladas de queijo minas frescal

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    Mariana Tavares Dias

    2012-12-01

    Full Text Available Foodborne disease caused by microorganisms is a problem of public health. Minas soft cheese is a national product manufactured using simple technology; it has high level of acceptance in the country making its production an important economic activity. Many microorganisms may be present in foods including the bacterium Escherichia coli (E. coli. Overall, E. coli is a harmless commensal bacterium; however, some strains may have a pathogenic potential. Several outbreaks of foodborne diseases associated with consumption of contaminated cheese have been reported, and the presence of pathogenic strains of E. coli has increased. The objective of this study was to isolate, evaluate the antimicrobial susceptibility, and characterize, by Multiplex PCR, the pathogenic E. coli strains isolated from Minas cheese commercialized in Rio de Janeiro. Thirty samples were analyzed and five strains of E. coli (EPEC were identified. The assessment of antimicrobial susceptibility revealed 40% of the isolates resistant to ampicillin and 40% with intermediate resistance to ampicillin-sulbactam combination. These findings are a warning signal to health authorities since Minas cheese is a ready to eat food product, and therefore should not pose health risks to the population.Doenças transmitidas por alimentos (DTA, causadas por microrganismos, representam um importante problema de saúde pública. O queijo Minas Frescal é um produto nacional, de tecnologia simples e elevada aceitação no País, tornando sua produção uma importante atividade econômica. Muitos microrganismos podem estar presentes neste alimento e, entre eles, destaca-se a bactéria Escherichia coli (E. coli. De modo geral, E. coli é um comensal inofensivo, entretanto, algumas cepas podem apresentar potencial patogênico. Diversos surtos de DTA, associados ao consumo de queijos contaminados, têm sido relatados e a presença de cepas patogênicas de E. coli cada vez mais observada. Este estudo teve

  13. Lesiones macro y microscópicas de intestino delgado de cerdos neonatos sin calostrar inoculados experimentalmente con cepas de E. coli fimbriadas Histopatholocial lesions in the small intestine of calostrum deprived pigs inoculated with strains of E. Coli bearing F4, F5, F6 y F41 fimbriaes

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    A.M CANAL

    1999-01-01

    Full Text Available La presente investigación se realizó con el propósito de evaluar los efectos patológicos de cepas enteropatógenas de E. coli que expresan antígenos fimbriales F4, F5, F6 y F41, administradas oralmente a cerdos neonatos que no ingirieron calostro. Los cerdos inoculados experimentalmente con las cuatro cepas enteropatógenas de E. coli presentaron diarrea acuosa y de color amarilla a las 4 h.p.i. Las lesiones macroscópicas se caracterizaron por congestión y abundante contenido acuoso, apreciándose diferencias solo en la intensidad lesional entre los diferentes grupos inoculados. Microscópicamente, el íleon fue el segmento más afectado, observándose congestión, adherencia bacteriana, vacuolización epitelial de las vellosidades intestinales, atrofia, infiltrados de neutrófilos y necrosis linfoide en placas de Peyer, siendo la cepa E. coli F4 responsable de las lesiones de mayor severidad. Los resultados de la presente investigación confirman la importancia de los antígenos fimbriales como factor de adhesión de cepas enteropatógenas de E. coli al intestino delgado de cerdos lactantes y permite proyectar a futuro metodologías que utilicen las propiedades antigénicas de las fimbrias no solo como métodos de diagnóstico sino también en la elaboración de inmunógenos los cuales evitarían la adhesión bacteriana y la presentación de cuadros de colibacilosis, enfermedad responsable de cuantiosas pérdidas económicas en la explotación porcina en la actualidadA study to evaluate the degrees of lesions caused by different enteropathogenic strains of E. coli was carried out. Newborn piglets without calostrum were innoculated with enteropathogenic strains of E. coli which contained F4, F5, F6 and F41 fimbriae in order to characterize the macro and microscopic lesions to the duodenum, jejunum and ilium. The pigs experimentally innoculated with the four enteropathegenic strains of E. coli presented watery, yellowish diarrhea four

  14. Respuesta de anticuerpos inducidos por la vacuna antimeningocócica cubana VA-MENGOC-BC® frente a la cepa de Neisseria meningitidis B:4:P1.19,15 en adolescentes después de 12 años de inmunizados

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    María A. Camaraza

    2006-12-01

    Full Text Available Se estudió la respuesta de anticuerpos inducida por la vacuna antimeningocócica cubana VA-MENGOC-BC® contra la cepa de Neisseria meningitidis B:4:P1.19,15 mediante el Ensayo Bactericida del Suero (EBS y ELISA de tipo indirecto, para medir anticuerpos contra vesículas de membrana externa (VME de N. meningitidis B a 184 adolescentes de un politécnico de Ciego de Ávila que fueron inmunizados en campañas masivas 12 años antes. Se realizaron extracciones de sangre antes de aplicar la primera dosis (T0, 4 semanas después de ésta (T1 y 4 semanas después de la segunda dosis (T2. Transcurridos 12 años de esta vacunación el 42% de los adolescentes presentó títulos bactericidas ≥ 1:4 frente a la cepa homóloga (B:4:P1.19,15 y el 98% mostró anticuerpos detectables contra las VME. En el EBS; el porcentaje de seroconversión T1/T0 fue del 57% y T2/T0 del 60%. Mediante ELISA la seroconversión fue del 59% y 54%, respectivamente, por lo que se demostró que la aplicación de una sola dosis después de 12 años indujo una respuesta inmune importante que puede sugerir una respuesta anamnésica.

  15. Resistencia bacteriana en cepas patógenas aisladas de mastitis en vacas lecheras de la V Región, Región Metropolitana y Xª Región, Chile Bacterial resistance of mastitis pathogens isolated from dairy cows in the Vth Region, Metropolitan Region and Xth Region, Chile

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    B SAN MARTIN

    2002-01-01

    Full Text Available La quimioterapia antimicrobiana en medicina humana y veterinaria es la principal herramienta terapéutica frente a los microorganismos patógenos causantes de enfermedades infecciosas; sin embargo, con el transcurrir de los años se ha observado la aparición de cepas multiresistentes. Dentro de las medidas utilizadas a nivel mundial para enfrentar este riesgo, están el uso de antimicrobianos bajo receta veterinaria, la rotación en el uso de estos fármacos y la instauración de programas permanentes de monitoreo de la resistencia bacteriana. Este trabajo forma parte de un proyecto de fármacovigilancia de resistencia bacteriana en el ganado lechero, cuyo objetivo fue determinar la sensibilidad en bacterias patógenas aisladas de mastitis en vacas lecheras de la V Región, Región Metropolitana (VR,RM y X Región (XR, frente a los antimicrobianos utilizados con mayor frecuencia en lecherías del país. Para evaluar la resistencia bacteriana, se utilizó el Método de Dilución en Placa con el fin de determinar la Concentración Mínima Inhibitoria (MIC de cada cepa bacteriana. En la VR,RM a partir de 963 muestras de leche, se lograron aislar 449 cepas bacterianas, observándose un fuerte predominio de E. coli (40.76%. En la XR, de 2.000 muestras se aislaron 1.012 cepas, observándose un claro predominio de S. aureus (55.53%. Las bacterias grampositivas (Staphylococcus aureus, Streptococcus spp y Staphylococcus coagulasa negativo presentaron altos porcentajes de resistencia ( 25%, frente a amoxicilina, ampicilina, penicilina, estreptomicina y lincomicina. Para S. aureus, un 6.15% y 3.74% de las cepas aisladas de la VR,RM y XR respectivamente, mostraron resistencia a cloxacilina. Las cepas de E. coli presentaron una mayor sensibilidad, no observándose resistencias superiores al 25%. De los resultados se puede concluir también que las bacterias causantes de mastitis en las regiones en estudio presentan resistencia a más de un antimicrobiano

  16. Use of natural enemies and biorational pest control of corne

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    Cipriano García Gutiérrez

    2012-09-01

    Full Text Available A general analysis of the potential use of natural enemies and biorational insecticides for control of main pests of corn in thestate of Sinaloa is presented. A discuss on their composition, dosage, toxicity and type of effect on beneficial organisms(natural enemies and pollinators is too included. The work revealed that is possible implement the use of these natural enemies and products for the control of neonate larvae of Spodoptera frugiperda fall armyworm (J. E Smith with Nomuraea rileyi (Farlow (Samson; against thrips Frankliniella occidentalis (Pergande using the nematodes Steinernema riobravis (Cabanillas and Poinar, S. feltiae (Filipjev and Heterorhabditis bacteriophora (Poinar at doses of 10,000 IJ (4x10 ~ IJ/m; against the corn silk fly Euxesta stigmatias (Loew encouraging the natural parasitism of Spalangia sp., while for the cutworm Agrotis ipsilon (Hufnagel can be with spinosad (soluble concentrate at doses of 0.123 kg a. i, and to the corn earwormHelicoverpa zea (Boddie using the analog of methoxyfenozide molting hormone (24% at 144 mg of a. i/L. The biorational control agents that not affect significantly to the natural enemies were the nucleopoliedrosis virus SfMNPV and SeMNPV; N. rileyi and Isaria fumosorosea (Wize; Bacillus thuringiensis (Berlinier; the azadirachtin (neem and parasitoids. In the case of products of chemical synthesis: Spinosad, oxymatrine and bifenthrin showed high rates of mortality in the control of corn pests, so these are considered as of high and moderate risk to Aphis mellifera (L. bees, the methoxyfenozide presented relatively low toxicity to natural enemies. In general, biorational products have repellent effect on larvae and adults of these insects, inhibit feeding and induce molting, also causing deformities and impede the development and growth, too interfere with sexual intercourse and copulate, reducing the oviposition, as well as cause sterility of adults, so these may also constitute a risk to

  17. Prevalência de sorotipos e resistência antimicrobiana de cepas invasivas do pneumococo em crianças: análise de 9 anos Prevalence of serotypes and antimicrobial resistance of invasive strains of pneumococcus in children: analysis of 9 years

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    Orlando Cesar Mantese

    2009-12-01

    Full Text Available OBJETIVO: Avaliar o perfil de sorotipos e a sensibilidade aos antimicrobianos de cepas de pneumococo obtidas de crianças e as implicações na formulação de vacinas pneumocócicas. MÉTODOS: Cepas de pneumococo isoladas no Hospital de Clínicas da Universidade Federal de Uberlândia, Uberlândia (MG, a partir de pacientes com doença invasiva, foram enviadas ao Instituto Adolfo Lutz, São Paulo (SP, para confirmação da identificação, sorotipagem e determinação da sensibilidade aos antimicrobianos. RESULTADOS: De abril de 1999 a dezembro de 2008, foram avaliadas 142 cepas de pneumococo obtidas de crianças de até 5 anos de idade. Setenta e cinco (52,8% eram de pacientes do sexo masculino, e a idade variou de 1 a 60 meses (média de 19±15,4 meses e mediana de 15 meses. Os diagnósticos clínicos mais comuns foram pneumonia [92 casos (64,8%] e meningite [33 casos (23,2%], e as principais fontes de recuperação foram sangue [61 amostras (43%], líquido pleural [52 (36,6%] e liquor [28 (19,7%]. Os sorotipos mais comuns foram o 14, 5, 6B, 1, 6A, 18C, 19A, 3, 9V, 19F, 23F, 9N e 10A. Foram detectadas 14 (9,9% cepas penicilina-resistentes, restritas aos sorotipos 14, 6B, 19F, 19A e 23F e predominantes no período de 2004 a 2008 (p = 0,000. Foi detectada sensibilidade diminuída ao cotrimoxazol (79,5%, à eritromicina e à clindamicina (11,3% cada e à ceftriaxona (5,6%. CONCLUSÕES: A resistência à penicilina foi detectada em 9,9% das cepas e predominou no período de 2004 a 2008. Foram identificados 20 diferentes sorotipos de pneumococo, e a cifra de cobertura pela vacina 7-valente atualmente disponível (PN CRM7 é de 71,9%.OBJECTIVE: To determine the prevalence of serotypes and antimicrobial susceptibility of strains of pneumococcus in children and to evaluate the implications for vaccine formulation. METHODS: Strains of pneumococcus obtained from children admitted with invasive diseases were isolated at Hospital de Clínicas of

  18. ISOLATION OF SHIGATOXIGENIC ESCHERICHIA COLI SEROGROUPS O157 AND O111 BY ISOLAMENTO DE CEPAS DE ESCHERICHIA COLI SHIGATOXIGÊNICAS SOROGRUPOS O157 E O111 POR SEPARAÇÃO IMUNOMAGNÉTICA APÓS DETECÇÃO POR PCR (NOTA DE PESQUISA

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    Luciano Menezes Ferreira

    2008-10-01

    Full Text Available

    The objective of this study was to verify the isolation tax by immunomagnetic separation (IMS of strains of Shigatoxin producing Escherichia coli serogroups O157 and O111 in dairy farms in Jaboticabal-SP, Brazil, starting from positive samples, detected by the polimerase chain reaction (PCR. Initially feces, water and milk samples were submitted to a selection process, through a PCR multiplex, in order to detect the presence of sequences stx1, stx2 and eae. All of the positive samples in this first phase were submitted to a new PCR reaction targeting the sequences rfb O157 and rfb O111, what resulted in, respectively, 14.8% and 0.2% of positive feces samples for those serogroups and 2.4% and 10.0%, respectively, of water and milk positive samples for the serogroup O157. Those PCR positive samples were submitted to IMS, isolated strains of E. coli O157, were obtained of only 53.6% of the feces samples. There were no isolated strains of E. coli O157 from water and milk samples, they were not also isolated strains of E. coli O111 from any sample type. In conclusion, IMS, although more sensitive than other techniques, still doesn’t allow the isolation of E. coli O157 and O111 strains, of 100% of the PCR positive samples.

    KEY WORDS: E coli O111, E. coli O157, immunomagnetic separation, PCR, shigatoxin.

    Este trabalho teve como objetivo verificar a taxa de isolamento por separação imunomagnética (IMS de cepas de Escherichia coli produtoras de shigatoxinas dos sorogrupos O157 e O111 em rebanhos leiteiros do Município de Jaboticabal, SP, a partir de amostras positivas, detectadas pela reação em cadeia da polimerase (PCR. Inicialmente, amostras de fezes, água e leite foram submetidas a um processo de triagem, por meio de uma PCR multiplex, a

  19. Desenvolvimento e avaliação de uma cepa knockout de Brucella abortus obtida pela deleção do gene virB10 Development and evaluation of a strain of Brucella abortus gotten by the knockout of the virB10 gene

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    Fabiane G. de Souza

    2009-11-01

    Full Text Available Brucella spp. são bactérias gram-negativas, intracelulares facultativas que são patogênicas para muitas espécies de mamíferos causando a brucelose, uma zoonose difundida mundialmente. Por isso a busca de alternativas de controle mais eficientes se faz necessário como o desenvolvimento de novas cepas que possam ser testadas como potenciais imunógenos. Neste estudo realizou-se a deleção do gene virB10 da cepa S2308 de Brucella abortus gerando uma cepa knockout provavelmente incapaz de produzir a proteína nativa correspondente. O gene virB10 faz parte de um operon que codifica para um sistema de secreção do tipo IV, essencial para a sobrevivência intracelular e multiplicação da bactéria em células hospedeiras. A deleção foi realizada pela construção do plasmídeo suicida pBlue:virB10:kan e eletroporação deste em células eletrocompetentes de B. abortus S2308, ocorrendo a troca do gene selvagem pelo gene interrompido, com o gene de resistência a canamicina, por recombinação homóloga dupla. Camundongos BALB/c foram inoculados com as cepas S19, RB-51, ΔvirB10 de B. abortus e B. abortus S2308 selvagem; os resultados demonstraram que camundongos BALB/c inoculados com S19 e camundongos BALB/c inoculados com S2308 apresentaram queda mais rápida de linha de tendência, quando comparadas aos demais grupos, para recuperação bacteriana (RB e peso esplênico (PE respectivamente. Os grupos que receberam ΔvirB10 S2308 de B. abortus e RB-51 demonstraram comportamento semelhante para ambas as características. Na sexta semana após a inoculação, os resultados para RB (log de UFC ± desvio padrão e PE (peso esplênico ± desvio padrão, respectivamente, mostraram: grupos inoculados com as cepas S2308 (4,44±1,97 e 0,44±0,11, S19 (1,83±2,54 e 0,31±0,04, RB-51 (0,00±0,00 e 0,20±0,01 e ΔvirB10 S2308 (1,43±1,25 e 0,19±0,03. Considerado o clearance bacteriano, todos os grupos diferiram estatisticamente do grupo que recebeu S

  20. Histological and morphometric investigations of changes induced by the RAL strain of Trypanosoma cruzi in the mouse placenta Investigações histológicas e morfométricas das alterações da placenta do camundongo causadas pela cepa RAL de Trypanosoma cruzi

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    Ana Amélia Carraro Abrahão

    2003-06-01

    Full Text Available Pregnant Swiss mice (Mus musculus were inoculated intraperitoneally with 2 x 10(5 trypomastigotes of the RAL strain of Trypanosoma cruzi on the 7th day of pregnancy and sacrificed on the 19th day of pregnancy. The placenta was sectioned for the assessment of histological and morphometric changes. The RAL strain showed intense tropism for the placenta, with parasitism reaching the three placental layers. There was involvement of the maternal and fetal portions of the placentas, and also of giant cells and spongioblasts. The placentas of infected animals presented sparse areas of degeneration and necrosis, with mild dystrophic calcification of the decidua. The inflammatory process consisted of plasmocytes and lymphocytes, revealing involvement of the decidua. Cytometric study of giant trophoblastic cells showed that the placentas of the infected group were seriously affected, also with respect to cell volume. The changes provoked by the RAL strain in the trophoblastic cells and the difference in behavior observed in the cell population of the various placental regions may affect intrauterine development, probably by a deficient production of hormones such as placental lactogen, which acts as a fetal growth hormone, or indirectly by deficient tissue invasion caused by inefficient utero-placental vascularization, thus impairing fetal nutrition.Camundongos suíços prenhes(Mus musculusforam inoculados, intraperitonealmente, com 2 x 10(5 tripomastigotas da cepa RAL de Trypanosoma cruzino 7º dia da prenhez e sacrificados no 19º dia da prenhez. Foram realizados cortes histológicos para avaliar as alterações histológicas e morfométricas das placentas. A cepa RAL mostrou intenso tropismo pela placenta, com parasitismo atingindo as três camadas placentárias. Houve envolvimento da parte materna e fetal das placentas, bem como das células gigantes e dos espongioblastos. As placentas dos animais infectados apresentaram escassas áreas de degenera

  1. Genital immunization of heifers with a glycoprotein Edeleted, recombinant bovine herpesvirus 1 strain confers protection upon challenge with a virulent isolate Imunização genital de bezerras com uma cepa recombinante do herpesvírus bovino tipo 1 defectiva na glicoproteína E confere proteção frente a desafio com um isolado virulento

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    Marcelo Weiss

    2010-01-01

    mild and transient vulvovaginitis (3/4 or mild to moderate genital lesions (1/4. In the IV group, the clinical signs lasted 4 to 8 days (x: 5.5 days. Clinical examination of the animals after challenge revealed that vaccination by both routes conferred some degree of protection, yet IV vaccination was clearly more effective in reducing the severity and duration of clinical disease. Furthermore, IV vaccination reduced the period of virus shedding in comparison with both groups. Taken together, these results demonstrate that SV265gE- is sufficiently attenuated upon IV vaccination in a low-titer dosis, is not readily reactivated after corticosteroid treatment and lastly, and more importantly, confers local protection upon challenge with a high titer of a virulent heterologous BoHV-1 isolate. Therefore, the use of this recombinant for genital immunization may be considered for prevention of BoHV-1-associated genital disease in the field.A infecção genital de novilhas ou vacas soronegativas pelo herpesvírus bovino tipo 1.2 (BoHV-1.2 pode resultar em vulvovaginite e infertilidade temporária. As vacinas atenuadas ou inativadas administradas pela via parenteral freqüentemente conferem proteção incompleta frente a desafio pela via genital. Este estudo relata uma avaliação da resposta imunológica e proteção conferida pela vacinação genital de bezerras soronegativas com uma cepa recombinante do BoHV-1 defectiva na glicoproteína E (SV265gE-. Um grupo de seis bezerras foi vacinado com a cepa SV265gE(0,2mL contendo 10(6,9TCID50 na submucosa da vulva (grupo IV; quatro bezerras foram vacinadas pela via intramuscular (IM; dose 10(7,6TCID50 e quatro bezerras permaneceram como controles não-vacinadas. As bezerras vacinadas pela via IV apresentaram edema e hiperemia leve e transitório na vulva e excretaram vírus em títulos baixos por alguns dias após a vacinação, porém uma bezerra soronegativa mantida em contato não soroconverteu. Administração de dexametasona

  2. Agentes bacterianos enteropatogênicos em suínos de diferentes faixas etárias e perfil de resistência a antimicrobianos de cepas de Escherichia coli e Salmonella spp Enteropathogenic bacterial agents in pigs of different age groups and profile of resistance in strains of Escherichia coli and Salmonella spp. to antimicrobial agents

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    Álvaro Menin

    2008-09-01

    Full Text Available As enterites infecciosas bacterianas provocam severas perdas para a indústria suína em todo o mundo. Os objetivos deste trabalho foram determinar os agentes bacterianos, associados com a ocorrência de diarréia em suínos, em diferentes faixas etárias, no Estado de Santa Catarina, Brasil, e verificar o perfil de resistência das cepas de Escherichia coli e Salmonella spp, frente aos principais antimicrobianos utilizados em granjas de suínos. Os principais gêneros/espécies bacterianos diagnosticados foram Escherichia coli, Clostridium spp, Salmonella spp Brachyspira hyodysenteriae, Brachyspira pilosicoli e Lawsonia intracellularis. Os fatores de virulência de E. coli mais prevalentes na fase de maternidade foram F5 / (K99 20%, F6 / (987P 16,3%, F42 6,8% e F41 5,7%, já nas fases de creche e terminação, predominaram cepas com fimbrias F4 (K88 11,2% e 5,4%, respectivamente. Para E. coli os maiores índices de resistência foram encontrados para oxitetraciclina (94% e tetraciclina (89,5% e os menores índices de resistência para neomicina (55%, ceftiofur (57,4%. Quanto às amostras de Salmonella spp, estas apresentaram maior resistência à oxitetraciclina (77%, e à tetraciclina (42,1% e menor à gentamicina (3,5% e amoxicilina (4,8%.Infectious bacterial enteritis causes severe losses to the swine industry worldwide. The objective of this study was to determine the epidemiology of bacterial agents that are associated with the occurrence of diarrhea in pigs at different age groups, and to verify the profile of resistance of strains of Escherichia coli and Salmonella spp to the main antimicrobial agents. The main bacterial species diagnosed were Escherichia coli, Clostridium spp, Salmonella spp, Brachyspira hyodysenteriae, Brachyspira pilosicoli and Lawsonia intracellularis. The E. coli virulence factors of higher prevalence in preweaning piglets were F5 / (K99 20%, F6 / (987P 16.3%, F42 6.8% and F41 5.7%, whereas at the nursery and with

  3. Produção de xilanases por uma cepa selvagem de Aspergillus nidulans - DOI: 10.4025/actascibiolsci.v25i1.2095 Xylanase production by a wild strain of Aspergillus nidulans - DOI: 10.4025/actascibiolsci.v25i1.2095

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    Maria Aparecida Ferreira Costa

    2003-04-01

    Full Text Available Uma cepa selvagem de Aspergillus nidulans isolada de solo produziu xilanase isenta de atividade celulolítica quando desenvolvida em meio submerso contendo sabugo de milho como principal substrato. Produção máxima de xilanase (220 U/mL foi obtida quando a cepa foi desenvolvida em meio mineral suplementado com sabugo de milho a 3% (p/v por 6 dias. Eletroforese com SDS revelou a ocorrência de quatro iso-xilanases, com pesos moleculares de 50, 43, 20 e 18 kDa. A xilanase bruta foi resistente à precipitação com acetona, apresentando atividade ótima em pH 5.0-6.0 e temperatura entre 50º e 55ºC. A enzima exibiu grande estabilidade quando exposta a condições alcalinas, e foi estável por várias horas quando exposta a temperaturas de até 55ºC, retendo 50% e 23% de sua atividade quando aquecida por 1 h a 60 e 65ºC, respectivamenteA wild strain of Aspergillus nidulans isolated from soil produce cellulase-free xylanase activity when developed on submerged cultures using corn cob powder as the main substrate. Maximum xylanase production (220 U/mL was obtained when the strain was developed in mineral medium supplemented with 3% (w/v corn cob for 6 days. SDS-PAGE revealed the occurrence of four isoxylanases with molecular weights of 50, 43, 20 and 18 kDa. Crude xylanase was resistant to acetone precipitation with 80% of recovery. The enzyme had optimal activity at pH values between 5.0 and 6.0 and temperature between 50-55oC. The enzyme exhibited high stability under alkaline conditions and temperature up to 55oC. It retained 50% and 23% of its activity when heated for 1 h at 60 and 65oC, respectively

  4. Actividad de metabolitos secundarios de Xenorhabdus bovienii - Poinar, simbionte del nematodo entomoparásito Steinernema feltiae sobre Fusarium spp en el cultivo de tomate – Solanum lycopersicum L.

    OpenAIRE

    Leguízamo Bermúdez, María Claudia

    2012-01-01

    Xenorhabdus bovienii (Enterobacteriaceae) es simbionte del nematodo entomoparásito Steinernema feltiae (Filipjev, 1934, Cephalobina, Steinernematidae) y sus metabolitos se consideran promisorios en el control biológico de patógenos como Fusarium spp, que ocasiona considerables pérdidas económicas en tomate Solanum lycopersicum L. en el Valle del Cauca. Esta investigación se realizó con el fin de evaluar la actividad antimicrobiana de algunos metabolitos secundarios de esta bacteria sobre aisl...

  5. Fotossensibilidade e termoestabilidade de vacinas contra o sarampo (cepa Biken CAM-70 liofilizadas e/ou reconstituídas para administração Photosensitivity and stability of freeze-dried and reconstituted (Biken CAM-70 strain measles vaccines

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    Edda de Rizzo

    1990-02-01

    Full Text Available Três lotes de vacinas contra o sarampo, produzidos com a cepa de vírus Biken CAM-70, sob as formas liofilizada e reconstituída, pertencentes ao estoque da rede de vacinação da Secretaria de Estado da Saúde de São Paulo, Brasil, foram submetidos a testes de sensibilidade à luz, à temperatura de 2 a 8°C, e de termoestabilidade (protegidos da luz às temperaturas de 28, 36,5 e 45°C, objetivando verificar por quanto tempo retinham sua potência, isto é, a concentração ideal recomendada para a cepa de vírus presente (3,70 log 10 DICT50 ou 5.000 doses infectantes de cultura de tecidos 50% por dose. A análise de retas de regressão ajustadas demonstrou que, de modo geral, tanto os lotes de vacinas liofilizados como os reconstituídos, mantidos às referidas temperaturas, expostos ou protegidos da luz, apresentaram queda de potência no decorrer do experimento, a qual foi mais acentuada para vacinas expostas à luz. Reconstituídos e mantidos a 2 a 8°C, os lotes não apresentaram homogeneidade no referente à sensibilidade à luz. Quando a fotossensibilidade de lotes de vacinas liofilizadas foi testada a 2 a 8°C eles mostraram-se mais sensíveis à degradação térmica quando expostos à luz do que quando protegidos dela. Entretanto, expostos ou protegidos, a potência foi inferior à minima aceita para a cepa Biken CAM-70. Às demais temperaturas, mesmo ao abrigo da luz, os dois lotes não retiveram potência mínima. Quanto às vacinas do lote 3, conservadas a 2 a 8°C, mantiveram-se de acordo com os requerimentos mínimos de potência durante 60 dias quando protegidas da luz, e durante 40 dias quando expostas a ela. A degradação térmica às demais temperaturas foi mais acentuada (28°C: 5 dias; 36,5°C: 2 dias; 45°C: 0,5 dia. Considerando a concentração viral mínima que vacinas produzidas com a cepa Biken CAM-70 devem conter para induzir efetiva resposta imunológica, os lotes de vacinas pesquisados (sob a forma liofilizada

  6. EFECTO DE LA INOCULACIÓN DE LA CEPA DE HONGOMICORRÍZICO ARBUSCULAR Glomus hoi-like EN LA RESPUESTA DE Brachiaria HÍBRIDO cv. MULATO II (CIAT 36087 A LA FERTILIZACIÓN ORGÁNICA Y NITROGENADA

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    Pedro J. González

    2011-01-01

    Full Text Available Se evaluó el efecto de la inoculación de la cepa dehongo micorrízico arbuscular (HMA Glomus hoi-like en larespuesta de Brachiaria híbrido cv. Mulato II (CIAT 36087 a lafertilización orgánica y nitrogenada. El experimento se realizó en laMicroestación de Pastos y Forrajes de la Empresa Pecuaria GenéticaNiña Bonita, en la provincia de Artemisa, sobre un suelo FerralíticoRojo Lixiviado. Se evaluaron once tratamientos conformados porlas aplicaciones de 15 y 30 t de estiércol vacuno.ha-1; 30 t de estiércolvacuno.ha-1 combinada con 150 kg de N.ha-1.año-1; 15 y 30 t deestiércol vacuno.ha-1, ambas combinadas con 0, 75 y 100 kg deN.ha-1.año-1 más la inoculación de G. hoi-like, así como los corres-pondientes testigos sin estiércol ni fertilizante nitrogenado, con ysin la inoculación de la cepa de HMA, los cuales se distribuyeronen un diseño de bloques al azar con cuatro réplicas. Se presentanlos resultados de los dos primeros años del establecimiento delpasto. El estiércol vacuno incrementó el pH y los contenidos demateria orgánica (MO, P asimilable y K intercambiable del suelo ysu efecto permaneció durante los dos primeros años de suaplicación; los mayores valores de esas variables se obtuvieroncon la dosis de 30 t.ha-1. La inoculación de G. hoi-like combinadacon las aplicaciones de 15 t de estiércol.ha-1 más 75 o 100 kgde N.ha-1.año-1, produjeron los mayores porcentajes decolonización micorrízica, densidad visual y densidad de esporas,así como contenidos de nutrientes en la biomasa y rendimientos demasa seca similares a los obtenidos con la aplicación de 30 t deestiércol.ha-1 más 150 kg de N.ha-1.año-1 sin inocular. El efecto de lainoculación de G. hoi-like en las estructuras micorrízicas y en lareducción de las dosis de ambos fertilizantes se mantuvo durantelos dos años en que se condujo el experimento.

  7. DISEÑO DE OLIGONUCLEÓTIDOS PARA EL ESTUDIO DE GENES CELULOLÍTICOS Y SOLVENTOGÉNICOS EN CEPAS COLOMBIANAS DE Clostridiumsp. (CLOSTRIDIACEAE Oligonucleotide Probe Design for the Study of Cellulolytic and Solventogenic Genes in Colombian Clostridiumsp. strains (Clostridiaceae

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    JOSÉ DAVID MONTOYA SOLANO

    Full Text Available El objetivo de este estudio fue analizar las rutas metabólicas para la producción de solventes y degradación de celulosa en cepas colombianas promisorias del género Clostridium. Para ello se diseñaron sondas de hibridación que sirvieran para posteriores estudios de mejoramiento genético de las cepas. Se construyó la base de datos denominada MULTICLOST en Microsoft Access® con las secuencias de 485 genes involucrados en las rutas metabólicas arriba mencionadas, provenientes de 45 especies bacterianas y 10 especies fúngicas. Los genes fueron agrupados de acuerdo al tipo de enzima y a los dominios catalíticos o de unión a sustrato en el caso de las celulasas. Cada grupo se sometió a alineamiento múltiple en ClustalW 1.83 y con base en los resultados se crearon subgrupos de similitud mayor al 50%. Se localizaron secuencias conservadas de longitud mayor a 19 nucleótidos en GeneDoc 2.6.002 y sus valores termodinámicos fueron estimados con GeneRunner v3.05, mientras que la sensibilidad y especificidad fue verificada por búsquedas en GenBank usando BLASTN 2.2.8. En total se obtuvieron 94 secuencias conservadas con las siguientes características: longitud promedio de 24 nucleótidos, Tm promedio de 65,8 ºC y contenido de (G+C entre 14,3 y 60,0%. Se determinó que ninguna de las sondas diseñadas forma estructuras secundarias estables con Tm superior a 36,1 ºC. De acuerdo a sus características y valores termodinámicos, todas las sondas podrían ser utilizadas en la construcción de un microarreglo o en reacciones de PCR para la identificación de regiones relevantes en el mejoramiento del proceso por ingeniería metabólica.The goal of the present study was to analyze the metabolic pathways involved in solvent production and cellulose consumption by promising Colombian native strains of the genus Clostridium. Therefore a set of oligonucleotide probes was designed, with the aim of analyzing potential targets for genetic improvement

  8. Homology among extra-cryptic DNA bands and the typical plasmids in Brazilian Yersinia pestis strains Homologia entre bandas extras de DNA críptico e os plasmídios típicos em cepas brasileiras de Yersinia pestis

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    Nilma Cintra Leal

    2000-03-01

    Full Text Available Yersinia pestis, the etiologic agent of plague, harbors three well-characterized plasmids: pFra (90-110kb, pYV (70 kb and pPst (9.5 kb. Furthermore, some extra-cryptic DNA bands have been observed in a number of wild strains from several foci of the world. Additional bands have also been reported in Brazilian strains. Looking for any relationship among these cryptic DNA bands and the three-prototypical plasmids, we analyzed twelve strains displaying different plasmid content. The DNA bands were hybridized by southern blot with probes directed at the genes caf1, lcrV and pla located respectively on the plasmids pFra, pYV and pPst. The probes were constructed by PCR amplification and labeled with digoxigenin. The Pla probe hybridized with its target (pPst and with bands of about 35 kb suggesting some homology among them. The Caf1 probe hybridized with the target (pFra as well as with higher bands. The LcrV also hybridized with the target (pYV and both with the bands higher than pFra and the bands between pFra and pYV. These results suggest that the large-cryptic bands could represent some rearrangement, open circular or linearized forms of the pFra and pYV plasmids.Yersinia pestis, o agente causador da peste, possui três plasmídios bem caracterizados: pFra (90-110 kb, pYV (70 kb e pPst (9.5 kb. Adicionalmente, algumas bandas extras de DNA críptico têm sido observadas em numerosas cepas selvagens em vários focos do mundo. Bandas extras também foram observadas em cepas brasileiras. Para verificar se existe alguma homologia entre as bandas extras de DNA críptico e os três plasmídios típicos, foram analisadas 12 culturas de Y. pestis através de hibridização com sondas dirigidas aos genes caf1, lcrV e pla localizados respectivamente nos plasmídios pFra, pYV e pPst. As sondas foram construídas através de amplificação por PCR e marcadas com digoxigenina. A sonda Pla reconheceu seu alvo (pPst e bandas de cerca de 35 kb sugerindo que

  9. Evaluation of pyrethroids toxicity in a laboratory strain and a fi eld population of Rachiplusia nu (Lepidoptera: Noctuidae using two bioassay techniques Evaluación de la toxicidad de piretroides en una cepa de laboratorio y una población de campo de Rachiplusia nu (Lepidoptera: Noctuidae usando dos métodos de bioensayo

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    Romina Russo

    2012-06-01

    Full Text Available Soybean is the most important crop in Argentina and Rachiplusia nu (Gueneé (Lepidoptera: Noctuidae is one of its main pests. In this study, the toxicity of five pyrethroids applied topically and by exposure to films on filter paper was evaluated on third instar larvae from a laboratory strain and a field population of R. nu. Four cyanopyrethroids and one non-cyanopyrethroid (permethrin were tested. All cyanopyrethroids showed the same order of increasing toxicity, regardless of the form of application and origin of the larvae: cypermethrin La soja es el cultivo más importante en la República Argentina y Rachiplusia nu (Gueneé (Lepidoptera: Noctuidae, una de sus principales plagas. En este estudio se evaluó la toxicidad de cuatro cianopiretroides y un no-cianopiretroide, aplicados en forma tópica o por exposición a filmes sobre papeles de filtro, en ninfas del tercer estadio de una cepa de laboratorio y una población de campo de R. nu. Todos los cianopiretroides mostraron el mismo orden de toxicidad creciente, independientemente de la forma de aplicación y del origen de las larvas: cipermetrina < ?-cihalotrina < deltametrina < ß-ciflutrina. Los valores de Dosis de Volteo para el 50% (DV50 y de Tiempo de Volteo para el 50% (TV50 aumentaron en función de la solubilidad de los cianopiretroides en agua. El no-cianopiretroide permetrina mostró un comportamiento diferente: fue el insecticida más tóxico para la cepa de laboratorio cuando se hizo una aplicación tópica, pero el menos tóxico cuando las larvas fueron expuestas a filmes sobre papeles de filtro. En general, todos los piretroides fueron más tóxicos para las larvas criadas en laboratorio que para las provenientes del campo. La estimación de los valores de Factor de Resistencia (FR permitió establecer que la población de campo presentaba resistencia moderada o baja a permetrina, cipermetrina y ?-cihalotrina, cuando los insecticidas fueron aplicados en forma tópica. Sin

  10. Diseño de oligonucléotidos para el estudio de genes celulolíticos y solventogénicos en cepas colombianas de Clostridium sp. (CLOSTRIDIACEAE Oligonucleotide Probe Design for the Study of Cellulolytic and Solventogenic Genes in Colombian Clostridiumsp. strains (Clostridiaceae

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    Suárez Moreno Zulma Rocío

    2007-12-01

    Full Text Available El objetivo de este estudio fue analizar las rutas metabólicas para la producción de solventes y degradación de celulosa en cepas colombianas promisorias del género Clostridium. Para ello se diseñaron sondas de hibridación que sirvieran para posteriores estudios de mejoramiento genético de las cepas. Se construyó la base de datos denominada MULTICLOST en Microsoft Access® con las secuencias de 485 genes involucrados en las rutas metabólicas arriba mencionadas, provenientes de 45 especies bacterianas y 10 especies fúngicas. Los genes fueron agrupados de acuerdo al tipo de enzima y a los dominios catalíticos o de unión a sustrato en el caso de las celulasas. Cada grupo se sometió a alineamiento múltiple en ClustalW 1.83 y con base en los resultados se crearon subgrupos de similitud mayor al 50%. Se localizaron secuencias conservadas de longitud mayor a 19 nucleótidos en GeneDoc 2.6.002 y sus valores termodinámicos fueron estimados con GeneRunner v3.05, mientras que la sensibilidad y especificidad fue verificada por búsquedas en GenBank usando BLASTN 2.2.8. En total se obtuvieron 94 secuencias conservadas con las siguientes características: longitud promedio de 24 nucleótidos, Tm promedio de 65,8 ºC y contenido de (G+C entre 14,3 y 60,0%. Se determinó que ninguna de las sondas diseñadas forma estructuras secundarias estables con Tm superior a 36,1 ºC. De acuerdo a sus características y valores termodinámicos, todas las sondas podrían ser utilizadas en la construcción de un microarreglo o en reacciones de PCR para la identificación de regiones relevantes en el mejoramiento del proceso por ingeniería metabólica.The goal of the present study was to analyze the metabolic pathways involved in solvent production and cellulose consumption by promising Colombian native strains of the genus Clostridium. Therefore a set of oligonucleotide probes was designed, with the aim of analyzing potential targets for genetic

  11. Respuesta serológica a la vacunación contra brucelosis en bovinos provenientes de un rebaño libre vacunados con dos dosis de vacuna Cepa RB-51 Serological response to brucellosis vaccination in bovines from a free herd vaccinated with two doses of RB-51

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    C Ramírez

    2009-01-01

    Full Text Available Se realizó una encuesta prospectiva con la finalidad de determinar la respuesta serológica a las pruebas oficiales aplicadas en Chile para la detección de brucelosis bovina que son Rosa de Bengala (RB, Fijación de Complemento (FC y Elisa de Competencia (C-Elisa, en hembras adultas vacunadas con dos dosis de vacuna Cepa RB-51 provenientes de un rebaño libre de la enfermedad con certificación vigente otorgada por el Servicio Agrícola y Ganadero (SAG del Ministerio de Agricultura de Chile. Se seleccionaron 100 hembras bovinas mayores de 18 meses con la finalidad de tener una confianza de un 90% de que la proporción de positivos no será mayor a un 2,95% si todos los animales muestreados resultan negativos. Los bovinos fueron vacunados vía subcutánes con vacuna Cepa RB-51 en dosis de 1-3.4 x 10(10 UFC con una diferencia de 30 días entre la primera y segunda aplicación; la fecha de la primera vacunación correspondió al día cero del estudio. Los días 0, 30 y 60 se tomaron muestras de 10 ml de sangre por venopunción coccígea de cada animal seleccionado. Las muestras se procesaron en el Laboratorio de Referencia de Brucelosis Bovina del SAG, Osorno, X Región, Chile. Ningún animal presentó reacción serológica atribuible a la vacunación con RB-51 que puedan interferir con las pruebas diagnósticas actualmente utilizadas para la detección de la brucelosis bovina.A prospective study was carried out in order to determine the serological response to the official tests used in Chile for the detection of bovine brucellosis which are Rose Bengal (RB, Complement Fixation (CF and Competing Elisa (C-ELISA, in adult cows vaccinated with two doses of vaccine strain RB-51 from a brucellosis free herd as certified by the Servicio Agrícola y Ganadero (SAG of the Ministry of Agriculture of Chile. A total of 100 female bovines older than 18 months were selected in order to be 90% confident that the proportion of positives in cows vaccinated twice

  12. Avaliação da eficácia da azitromicina e pirimetamina em camundongos infectados por cepa cistogênica de Toxoplasma gondii Evaluation of the efficacy of azithromycin and pyrimethamine, for treatment of experimental infection of mice with Toxoplasma gondii cystogenic strain

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    Susana A.Z. Lescano

    2004-12-01

    Full Text Available Foi avaliada a eficácia da administração prolongada de azitromicina e pirimetamina em camundongos infectados com cepa cistogênica de Toxoplasma gondii. Os animais foram inoculados intraperitonealmente com um cisto de T. gondii e, após 20 dias, divididos em quatro grupos: GI infectados não tratados, GII infectados e tratados concomitantemente com pirimetamina (12,5mg/kg/dia e azitromicina (100mg/kg/dia, GIII infectados e tratados com a mesma dose de pirimetamina e GIV infectados e tratados da mesma forma com azitromicina. O tratamento, via oral, estendeu-se por 120 dias; após este período os animais foram sacrificados e foi feita a contagem dos cistos no cérebro. A associação de ambos os medicamentos proporcionou melhores resultados, diminuindo a contagem de cistos no cérebro dos animais tratados de forma concomitante.The efficacy of prolonged administration of azithromycin and pyrimethamine was evaluated in mice experimentally infected with cystogenic strain of Toxoplasma gondii. The animals were intraperitoneally inoculated with one cyst of T. gondii and after 20 days were allocated into four groups: GI, infected without treatment; GII, infected and treated with the association of pyrimethamine (12.5mg/kg/day and azithromycin (100mg/kg/day; GIII, infected and treated with the same dose of pyrimethamine; and GIV, infected and treated in the same way with azithromycin. The oral treatment lasted 120 days, after this period all the animals were sacrificed and the count of cysts in the brain was done. The association of both drugs provided the best results, by diminishing the cyst count in the brain of the animals treated in this way.

  13. Produção e caracterização de anticorpos monoclonais contra uma cepa do herpesvírus bovino tipo 1 defectiva na glicoproteína C (gC Production and characterization of monoclonal antibodies to a bovine herpesvirus type 1 strain defective on the glycoprotein C

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    Evandro Reinoldo Winkelmann

    2007-08-01

    Full Text Available A maioria dos anticorpos monoclonais (AcMs já produzidos contra o herpesvírus bovino tipo 1 (BoHV-1 reage com a glicoproteína C (gC, um antígeno abundante e imunodominante presente no envelope viral. Com o objetivo de produzir AcMs com outras especificidades protéicas, antígenos de uma cepa do BoHV-1 defectiva no gene da gC foram utilizados para a imunização de camundongos BALB/c. Após fusão e seleção de 54 hibridomas resistentes ao meio seletivo HAT, foram obtidos três clones (1F1, 2H4 e 4D7 secretores de imunoglobulinas da classe IgG2a, que reagiram com antígenos da cepa homóloga. Os AcMs reagiram com antígenos virais nas técnicas de imunofluorescência (IFA e imunoperoxidase (IPX em diluições de até 1:640 (sobrenadante de cultivo e 1:20.000 (fluído ascítico. Os três AcMs apresentaram um espectro amplo de reatividade, reagindo com antígenos de 14 herpesvírus isolados de doença respiratória ou genital (provavelmente BoHV-1 e com 17 isolados de doença neurológica (supostamente BoHV-5, e apresentaram atividade neutralizante em níveis variáveis contra todos esses isolados. A especificidade protéica dos AcMs não pode ser determinada diretamente, pois nenhum deles reagiu com proteínas virais na técnica de Western blot. Por outro lado, os três AcMs reagiram em IFA com células infectadas com uma cepa do BoHV-5 defectiva nas glicoproteínas E, I e proteína US9, o que exclui estes antígenos como possíveis alvos dos AcMs. Por exclusão (gC, gE, gI e pela sua forte atividade neutralizante, os AcMs são provavelmente direcionados contra epitopos conservados de outras glicoproteínas do envelope viral que contêm epitopos neutralizantes: a gB e/ou gD. Pelo seu alto título de reação e pelo amplo espectro de reatividade, esses AcMs possuem potencial aplicação em técnicas diagnósticas. Além disso, podem ser úteis para o mapeamento de epitopos neutralizantes conservados nas glicoproteínas do envelope

  14. Caracterização biológica, histopatológica e análise de ácido nucléico de uma cepa Trypanosoma cruzi da região de Marília, SP Biological and histopathological characterization together with nucleic acids analysis of a Trypanosoma cruzi strain from Marília, São Paulo State

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    Luciamáre Perinetti Alves Martins

    2003-01-01

    Full Text Available Estudou-se o comportamento biológico e histopatológico de uma cepa genuínamente mariliense de Trypanosoma cruzi, isolada em 1997 através de xenodiagnóstico artificial. Vinte e cinco camundongos swiss foram infectados intraperitonealmente, sendo 11 utilizados para a realização da curva parasitêmica e observação da morfologia dos tripomastigotas e 14 foram sacrificados após o 17, 23, 30, 60 e 180 dias pós-infecção e coletados coração, esôfago, fígado, cólon, e músculo esquelético (fragmento da coxa direita para análise histopatológica. Cultura em meio LIT foi realizada para análise de DNA. Os resultados mostraram predomínio de formas largas, baixa parasitemia com picos médios de 860 tripomastigotas/5mil de sangue ao redor do 20º dia de infecção. Nenhum camundongo morreu na fase aguda da infecção. Exame histopatológico mostrou poucos ninhos de amastigotas em coração, raros em músculo esquelético e cólon com discreto processo inflamatório. Comparada com a cepa Y, que foi isolada de uma paciente da mesma região, notamos diferentes características biológicas e comportamentais, porém a análise de DNA as coloca no mesmo grupo, demonstrando a proximidade dessas cepas.The aim of this report was to study the biological and histopathological behavior of a Trypanosoma cruzi strain, which is found in the region of Marília. The strain was isolated in 1997, by artificial xenodiagnosis. Twenty-five swiss mice were intraperitoneally inoculated. Eleven were used for observation of parasitemia and trypomastigotes morphology and 14 were sacrificed after 17, 23, 30, 60 and 180 days post-infection. Heart, esophagus, liver, colon, and skeletal muscle (fragment of the right thigh were collected for histopathological study. LIT culture medium was accomplished for DNA analysis. The results showed predominance of broad forms, low parasitemia with mean peaks of 860 trypomastigotes/5mul of blood of the 20th day of infection. No

  15. Plasmid composition and virulence-associated factors of Yersinia pestis isolates from a plague outbreak at the Paraíba State, Brazil Composição plasmidial e fatores associados à virulência em cepas de Yersinia pestis de um surto de peste no Estado da Paraíba, Brasil

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    Nilma Cintra Leal

    1989-10-01

    Full Text Available Pathogenic Yersinia pestis isolates were collected during a plague outbreak at the Paraiba State in 1986. The Y. pestis isolates were investigated for the presence of virulence-associated factors and plasmid content. All strains analysed were proficient in the expression of the VW and fraction 1 antigens, pigment adsorption and pesticin-fibronolysin-coagulase production. A similar plasmid profile composed by four plasmid with molecular weight of 60, 44, 14.9, and 6.4 Megadaltons (MD was found in all strains. DNA cleavage with EcoRI restriction enzyme further demonstrated the uniform plasmid content of the Y. pestis isolates. Seven additional Y. pestis strains, previously isolated in the same region but in an endemic state, showed the same plasmid fingerprint. The lack of any detectable difference between epidemic and endemic isolates as well as the value of plasmid fingerprints in epidemiology of Y. pestis is discussed.Cepas patogênicas de Yersinia pestis foram coletadas durante um surto de peste no Estado da Paraíba em 1986. Os isolados de Y. pestis foram analisados quanto a presença de fatores associados à virulência e conteúdo plasmidial. Todas as linhagens analisadas foram proficientes na expressão dos antígenos VW e fração 1, além de possuírem capacidade de adsorção de pigmentos e produção de pesticina-fibrinolisina-coagulase. Um perfil plasmidial semelhante composto por quatro plasmídeos com peso molecular de 60, 44, 14.9, e 6.4 MD foi encontrado em todas as linhagens. A clivagem do DNA plasmidial com a enzima de restrição EcoRI demonstrou o conteúdo plasmidial uniforme dos isolados de Y. pestis. Sete outras linhagens de Y. pestis, isoladas previamente no mesmo local mas em condição endêmica, mostraram o mesmo perfil plasmidial. A falta de diferenças entre os isolados epidêmicos e endêmicos assim como o uso do perfil plasmidial na epidemiologic de Y. pestis e discutida.

  16. Quantitative toxoplasma gondii oocyst detection by a modified Kato Katz test using Kinyoun staining (KKK in ME49 strain experimentally infected cats Detecção quantitativa de oocistos de Toxoplasma gondii, por um teste modificado de Kato Katz usando coloração de Kinyoun (KKK, em gatos infectados experimentalmente com a cepa ME49

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    Luciana Regina Meireles

    2008-06-01

    Full Text Available We detected Toxoplasma gondii oocysts in feces of experimentally infected cats, using a Kato Katz approach with subsequent Kinyoun staining. Animals serologically negative to T. gondii were infected orally with 5x10² mice brain cysts of ME49 strain. Feces were collected daily from the 3rd to the 30th day after challenge. Oocysts were detected by qualitative sugar flotation and the quantitative modified Kato Katz stained by Kinyoun (KKK. In the experimentally infected cats, oocysts were detected from the 7th to 15th day through sugar flotation technique, but oocysts were found in KKK from the 6th to 16th day, being sensitive for a larger period, with permanent documentation. The peak of oocysts excretion occurred between the 8th to 11th days after challenge, before any serological positive result. KKK could be used in the screening and quantification of oocysts excretion in feces of suspected animals, with reduced handling of infective material, decreasing the possibility of environmental and operator contamination.Detectamos oocistos de Toxoplasma gondii em fezes de gatos experimentalmente infectados, usando a abordagem de Kato Katz, com subseqüente coloração pelo método de Kinyoun. Animais sorologicamente negativos ao T. gondii foram infectados por via oral com 5x10² cistos da cepa ME49 de cérebros de camundongos. Fezes foram colhidas diariamente a partir do 3º até o 30º dia pós-infecção. Oocistos foram detectados por centrífugo-flutuação em sacarose qualitativa e pelo método quantitativo de Kato Katz modificado corado pela técnica de Kinyoun (KKK. Em gatos experimentalmente infectados, oocistos foram detectados do 7º ao 15º dia pela técnica de centrífugo-flutuação em sacarose, mas oocistos foram detectados do 6º ao 16º dia pelo KKK, sendo sensível por um período maior, com documentação permanente. O pico da excreção de oocistos ocorreu entre 8º a 11º dia pós-infecção, antes de resultado sorológico positivo

  17. Atividade anti-fúngica do neem e jurema-preta sobre cepas de Candida spp isolados de vacas com mastite subclínica no Estado de Pernambuco Anti-fungal activity of neem and jurema-preta on samples of isolated Candida spp of cows with subclinical mastitis in the State of Pernambuco

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    Andréia V. Pereira

    2009-12-01

    Full Text Available O objetivo deste estudo foi avaliar a atividade anti-fungica (in vitro do neem (Azadiracta indica A. Juss. e de jurema preta (Mimosa tenuiflora (Wild Poir. sobre cepas de Candida spp. isoladas de casos de mastite subclínica em vacas no Estado de Pernambuco. As folhas do neem foram coletadas em árvores de fazendas do município de Patos-PB e a casca da jurema-preta foi coletada na UFCG, Campus de Patos e preparados extratos etanólicos. As amostras de Candida spp. foram coletadas de leite de vacas com mastite subclínica e semeadas em placas de Petri contendo ágar-base acrescido de 5% de sangue desfibrinado de ovino Sabouraud. As placas foram incubadas em estufa bacteriológica a 37 ºC e a leitura foi realizada com 24 e 48 h. Os ensaios foram realizados em duplicata e o resultado final foi determinado pela média aritmética dos halos de inibição. A avaliação microbiológica destes ensaios demonstrou que o extrato da casca da jurema-preta apresentou atividade antifúngica bastante satisfatória sobre a levedura de C. albicans, proporcionando resultado superior aos obtidos com o extrato do neem e fluconazol.The leaves of neem were collected on farms of the city of Patos-PB, and the bark of jurema-preta was collected in the UFCG - Campus of Patos-PB, and the extracts were prepared from the ethanol. The samples of Candida spp. were collected in milk of cows with subclinical mastitis and sown in plates of Petri containing agar-base 5% increased of de-fiber blood of sheep Sabouraud. The plates were incubated in bacteriological greenhouse 37 ºC and the reading was carried through with 24 and 48 h. The assays were carried through in duplicate and the final result was determined by the arithmetic mean of inhibition halos. The microbiological evaluation of these assays demonstrated that the extract from the bark of jurema-preta showed antifungal activity quite satisfactory on the yeast C. albicans, providing superior results to those obtained

  18. Antimicrobial resistance profile, phage typing and molecular characterization of Salmonella Enteritidis strains from poultry originPerfil de resistência a antimicrobianos, fagotipagem e caracterização molecular de cepas de Salmonella Enteritidis de origem avícola

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    Marciane Magnani

    2012-05-01

    Full Text Available Salmonella enterica subsp. enterica serovar Enteritidis (SE is currently responsible for significant losses in the poultry industry with consequences on public health. In the present study, 38 SE isolates from biological material of chicken breeders were characterized using phage typing, antimicrobial resistance profile and pulsed field gel electrophoresis (PFGE. The phage type (PT 7 and 9 were predominant and 26.3% of the isolates were resistance to nalidixic acid (NAL. The phage typing and analysis of antimicrobial resistance profile showed high discriminatory power (0.85. The PFGE profile of 13 strains with XbaI and SpeI discriminated the SE phage types, as well characterized strains from the same serovar. The results showed the importance to associate different methods for the characterization of SE and suggest that poultry products may have been source of human salmonellosis in the Parana State during the period of study. Salmonella enterica subsp. enterica sorovar Enteritidis (SE é responsável por prejuízos significativos à avicultura, com conseqüências importantes para saúde pública. No presente estudo foi realizada a caracterização de 38 isolados de SE provenientes de material biológico de reprodutoras destinadas à produção de frangos de corte através de fagotipagem, perfil de resistência antimicrobiana e de eletrofose de campo pulsado (PFGE. Os fagotipos (PT predominantes foram PT7 e PT9 e 26,3% dos isolados apresentaram resistência ao ácido nalidíxico (NAL. A fagotipagem e a análise do perfil de resistência antimicrobiana juntos mostraram elevado poder discriminatório (0,85. Os perfis de PFGE de 13 cepas, com as endonucleases XbaI e SpeI permitiram discriminar os fagotipos de SE, bem como associar perfis de um mesmo fagotipo. Os resultados mostram a importância da associação de métodos para a caracterização de SE e sugerem que produtos da avicultura de corte podem ser fonte de salmonelose humana.

  19. Efecto del pH, cepa bacteriana y tipo de muestra, en la detección microbiológica, de ácido oxolínico y oxitetraciclina en peces Influence of pH, microbial strain and sample type, on the microbiological detection of oxolinic acid and oxitetraciclyne in fish

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    ERIKA GESCHE

    2001-01-01

    Full Text Available Junto al desarrollo de la salmonicultura, surge la necesidad de aplicación de antimicrobianos para el control de enfermedades de los peces, aumentando el riesgo de la presencia de residuos en el producto destinado al consumo. Con la finalidad de aportar antecedentes a la detección microbiológica de residuos de ácido oxolínico y oxitetraciclina en peces, se trataron, 75 peces de la especie Salmo salar con cada uno de los antibióticos. Para ello se escogieron peces con un peso promedio de 2,7 Kg, y durante 10 días se les administró por vía oral la dosis indicada por el fabricante para ambos antibacterianos. Finalizado el período de tratamiento, se tomaron muestras de músculo y suero de 5 peces en los días 1 a 5 y 10, 15, 20 y 30 post tratamiento. Las muestras fueron conservadas en congelación para luego ser analizadas por el método de detección del antibiótico por inhibición bacteriana, utilizando Bacillus subtilis BGA y E. coli ATCC 11303 como cepas sensibles, incluidas en un medio de cultivo nutritivo a pH 6,0 y 8,0 respectivamente. Muestras de suero y de músculo de cada pez se colocaron en duplicado en cada una de las 4 placas de Petri con los diferentes substratos de cultivo. Después de la incubación de las placas a 35 ºC por 24 h se midió el halo de inhibición bacteriana (en mm provocado por la difusión del residuo. Los resultados demuestran que el ácido oxolínico y la oxitetraciclina se detectan mejor en el substrato a pH 6,0, y que la cepa Bacillus subtilis BGA, es más sensible que E.coli ATCC 11303, a la detección de ambos antibacterianos. Las muestras de suero provocaron halos de inhibición de mayor tamaño que las de músculo del mismo pez y demostraron una mayor persistencia del residuo a través del tiempo de depleción de los fármacosSimultaneously with the development of the salmoniculture, comes forth the need to use antimicrobial drugs to control fish disease thus, increasing the risk of residues in

  20. Efectos beneficiosos en niños sanos del consumo de un producto lácteo que contiene dos cepas probióticas: Lactobacillus coryniformis CECT5711 y Lactobacillus gasseri CECT5714 Beneficial effects of consumption of a dairy product containing two probiotic strains: Lactobacillus coryniformis CECT5711 and Lactobacillus gasseri CECT5714 in healthy children

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    F. Lara-Villoslada

    2007-08-01

    Full Text Available Objetivo o antecedente: En las últimas décadas la manipulación de la microbiota intestinal mediante el uso de probióticos ha adquirido un gran interés en el tratamiento y prevención de determinadas patologías infantiles. Además actualmente existen multitud de estudios que demuestran que las bacterias probióticas podrían tener un importante papel en el desarrollo del sistema inmunitario. Estudios recientes sugieren que dos cepas probióticas, Lactobacillus coryniformis CECT5711 y Lactobacillus gasseri CECT5714 mejoran la función intestinal de adultos sanos y potencian la respuesta inmunitaria. Dado que son muy pocos los estudios que analizan el papel de los probióticos en niños sanos, principales consumidores de estos productos, el objetivo del presente trabajo fue analizar los efectos de la administración conjunta de estas dos cepas probióticas en un producto lácteo fermentado en niños sanos. Intervenciones: Se reclutaron 30 niños de entre 3 y 12 años sin patología gastrointestinal conocida. Además de su dieta habitual, durante las 3 primeras semanas los niños recibieron 200 ml de un yogurt convencional que contenía Lactobacillus bulgaricus y Streptococcus thermophilus. A continuación este yogurt se sustituyó por 80 ml de un producto probiótico (Max Defensas® Puleva FOOD S.L. que contenía la misma cantidad de Streptococcus thermophilus y donde el L. bulgaricus fue substituido por la misma cantidad de una mezcla de las bacterias probióticas objeto del estudio: L. coryniformis CECT5711 y L. gasseri CECT5714. Se tomaron muestras de heces y de saliva al comienzo del estudio, a las 3 semanas y al finalizar el estudio. Durante estas 6 semanas los niños no tomaron otro yogurt o probiótico que no fueran los citados anteriormente. Se analizó la microbiotafecal de los niños, la toxicidad de las aguas fecales y la capacidad de éstas para inhibir la adhesión de Salmonella cholerasusis ssp. cholerasuis a mucinas

  1. Soil fertility, organic carbon and fractions of the organic matter at different distances from eucalyptus stumps Fertilidade do solo, carbono orgânico e frações da matéria orgânica em diferentes distâncias da cepa de eucalipto

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    Geraldo Erli Faria

    2009-06-01

    fractions of soil organic matter in the topsoil layer reflect the deposition and maintenance of forest residues on the soil surface, mainly after forest harvest.O conhecimento das variações vertical, horizontal e temporal de características químicas do solo sob cepas remanescentes de eucalipto é de fundamental importância para o manejo de cultivos subsequentes. O objetivo deste trabalho foi avaliar o efeito de cepas remanescentes de eucalipto (CRE na variabilidade espacial de características químicas em um Argissolo Amarelo distrófico típico localizado na região litorânea do Espírito Santo. Para isso, foram selecionadas CRE com 31 e 54 meses de idade, em duas áreas experimentais com características semelhantes, a fim de avaliar os efeitos da decomposição delas sobre características químicas do solo. Dessa forma, amostras de solo foram coletadas ao redor dessas CRE e nas distâncias de 30, 60, 90, 120 e 150 cm, nas camadas de 0-10, 10-20 e 20-40 cm de profundidade, na direção da linha das CRE, as quais se situavam na entrelinha de povoamentos de eucalipto de mesma idade, cultivados no espaçamento de 3 x 3 m. O procedimento de amostragem de solo foi realizado em cinco parcelas de 900 m² . As amostras de solo foram analisadas para: pH em água, P e K disponíveis (Mehlich-1, Al, Ca e Mg trocáveis, C orgânico total (COT e teores de C nas substâncias húmicas (SH e na fração leve livre. Os resultados obtidos indicaram variação nos valores de pH e nos teores de P, K, Ca2+, Mg2+ e Al3+ à medida que se afastou das CRE aos 31 e 54 meses, entre as camadas de solo amostradas. Os maiores valores de pH, P, K, Ca2+ e Mg2+ foram constatados na camada superficial do solo, e os menores, para Al3+ . Os teores de C orgânico das diversas frações da matéria orgânica do solo decresceram à medida que se afastou das CRE aos 31 e 54 meses, nas camadas de 0-10 e 10-20 cm de profundidade, indicando que a ciclagem de raízes (e tocos e a rizodeposição contribuem

  2. Treatment Effects of Onion (Allium cepa) and Ginger

    OpenAIRE

    Hussein Nikniaz; Arash Davatgar Badie; Alireza Farnam; Arash Khaki

    2012-01-01

    Objective: The aim of the present study was to evaluate the beneficial degree of sexual behavior in male rats after inducement of onion and ginger in lamotrigine receiving groups. Material and Methods: Wistar rats (n=70) (male=35, female=35) were allocated so that males were divided into seven groups: control (n=5) and test groups (n=35). Control group used normal Saline (3 cc for each rat). Lamotrigine group were given Lamotrigine (10 mg/kg). Onion group used onion fresh juice (3 cc for eac...

  3. Sifat Antirayap Ekstrak Kulit Bawang merah (Allium cepa L.)

    OpenAIRE

    Sari, Margaretha Uliartha

    2013-01-01

    The problem of termites attack in the building is estimated be the most high because of the high rate of development, land conversion, development of settlements in the area in addition a very dense population so as disturbed the life of termites. The alternative to solve the problem was used natural biotermiticida like onion husk extract. This research aims to find out rate of extract and onion husk lost weight percentage test sample, evaluate the toxicity level of onion husk ...

  4. Treatment Effects of Onion (Allium cepa and Ginger

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    Hussein Nikniaz

    2012-09-01

    Full Text Available Objective: The aim of the present study was to evaluate the beneficial degree of sexual behavior in male rats after inducement of onion and ginger in lamotrigine receiving groups. Material and Methods: Wistar rats (n=70 (male=35, female=35 were allocated so that males were divided into seven groups: control (n=5 and test groups (n=35. Control group used normal Saline (3 cc for each rat. Lamotrigine group were given Lamotrigine (10 mg/kg. Onion group used onion fresh juice (3 cc for each rat/daily. Ginger group was fed on ginger powder (100 mg/kg/daily. Onion & Lamotrigine group used both onion juice (3 cc fresh onion juice for each rat/day and Lamotrigine (10 mg/kg. Ginger & Lamotrigine group used both ginger powder (100 mg/kg/day and Lamotrigine (10 mg/kg/day. Onion, ginger & Lamortigine group jointly used ginger powder (100 mg/kg/day and onion juice (3 cc juice for each rat and Lamotrigine (10 mg/kg/day. All groups were given treatments orally. For sexual behaviors, Estradiolbenzoate (50 microgram and 6 hours before test (500 microgram progesterone was injected to the female rats subcutaneously. Then rats were viewed for erection, ejaculation and cup.Results: There was maximum Serum total testosterone level in the onion group, there was maximum malondialdehyde (MDA in the Lamotrigine group and there was maximum total antioxidant capacity in both the onion group and ginger group (p<0.05. Conclusion: Results revealed that administration of (100 mg/kg/day of ginger powder, and freshly prepared onion juice (3 cc for each rat, significantly lowered the adverse effects of lamotrigine, and can have beneficial effects on sexual behavior in male rat.

  5. The Root-inhibiting Substance of Allium Cepa

    NARCIS (Netherlands)

    Stolk, Anth.

    1953-01-01

    Whereas scientific research on inhibiting substances has mainly occupied itself with the effect of these substances on the germination process, I was able to demonstrate the presence of a root-inhibiting agent during my studies on root formation in Fuchsia hybrida and Pelargonium zonale (Stolk, 1952

  6. FERMENTATION AND AEROBIC LOSSES IN CORN GRAIN ENSILED WITH Lactobacillus buchneri “NCIMB 40788” EFEITO DE DOSES DE Lactobacillus buchneri “CEPA NCIMB 40788” SOBRE AS PERDAS NOS PERÍODOS DE FERMENTAÇÃO E PÓS-ABERTURA DA SILAGEM DE GRÃOS ÚMIDOS DE MILHO

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    Estella Rosseto Janusckiewicz

    2008-12-01

    Full Text Available This research was carried out to evaluate the corn grain ensiled with different Lactobacillus buchneri (NCIMB 40788 levels (5 x 104, 1 x 105, 2 x 105 e 4 x 105 UFC/g of the ensiled corn grains, and control. It was determined the losses during the fermentation and air exposition phases. The DM, and ammonia nitrogen contents, pH values, yeast and fungal populations were determined during the silage fermentation, and air exposition phase. The data were analyzed according to a randomized block design, in a split plot schedule with four replications. The L. buchneri utilization did not affect the corn grain fermentation, but controlled the yeast and fungal growth. It was recorded average pH values (4.2, gas losses (2.68%, and effluent (2.56 kg/t of silage and RMS (98.24%. However, during the air exposition, the silage inoculated with 1x105 CFU/g  of mass ensiled the time to break the stability. The inoculation using L. buchneri (1 x 105 UFC/g of corn grain was efficient on the yeast and fungal growth control, and increased the aerobic stability. However, the highest levels of additive utilization were more efficient, but is necessary to evaluate the economic aspects of this technique.

    KEY WORDS: Additives, aerobic stability, ensilage, fermentation, losses. Objetivou-se avaliar o efeito do Lactobacillus buchneri (cepa NCIMB 40788 nas silagens de grãos úmidos de milho tratadas com quatro doses do inoculante (5x104, 1x105, 2x105 e 4x105 UFC/g de massa ensilada mais o grupo-controle. Determinaram-se as perdas durante a fermentação, e durante a exposição aeróbia avaliaram-se os teores de MS, de nitrogênio amoniacal, valores de pH e contagem de fungos e leveduras. Constatou-se que a inclusão do L. buchneri nas silagens de grãos úmidos de milho não influenciou os parâmetros avaliados na fermentação, registrando-se valores médios de pH (4,2, perda por gases (2,68% e por efluente (2,56 kg/t de silagem e RMS (98,42%. No entanto

  7. Efecto de una dieta con bajo aporte de selenio sobre la respuesta inmune a la vacuna Brucella abortus Cepa RB51 en vacas lecheras Effect of a low selenium diet on the immune response to Brucella abortus strain RB51 vaccine in dairy cows

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    V Leyán

    2006-01-01

    Full Text Available Se estudió el efecto de una dieta con bajo aporte de selenio (Se sobre la respuesta inmune a la vacuna Brucella abortus Cepa RB51 y la concentración de inmunoglobulinas séricas en vacas. Se utilizaron 12 vacas Friesian, estabuladas desde aproximadamente dos meses preparto y hasta el cuarto mes de lactancia mantenidas con una dieta basada en heno de pradera con bajo contenido de Se (0,02 ppm de MS y balanceada según requerimientos para el resto de nutrientes. Seis vacas conformaron el grupo de animales con bajo aporte de Se (Se-D y otras seis el grupo de animales suplementados (Se-S con selenato de bario (1 mg de Se/kg , 45 días previos al parto. Los animales fueron inmunizados con la vacuna RB51 al cuarto mes del experimento. Muestras de sangre fueron obtenidas previo a la suplementación con Se y cada 15 días hasta el término del experimento. El balance de Se fue medido mediante la actividad sanguínea de GSH-Px. Las concentraciones séricas de IgG, IgM e IgA se determinaron por inmunodifusión y los anticuerpos específicos contra Brucella abortus mediante ELISA y la respuesta inmune celular mediante pruebas de intradermorreacción a antígenos de Brucella abortus y estudio histológico de la reacción. La dieta con bajo contenido de Se provocó una disminución lenta y progresiva de la actividad de GSH-Px (The effect of a diet with a low selenium (Se content on the immune response to Brucella abortus Strain RB51 vaccine in dairy cows and in their serum inmunoglobulin concentrations was studied. Twelve pregnant Friesian cows (7 to 8 months were randomly allocated into two homogeneous groups of six animals each. Animals were maintained during 6 months in individual cubicles with water ad libitum and a diet based on grass hay with a low Se content (0.02 ppm base on dry matter and nutritionally balanced for other nutrients. One group was maintained only with the low Se diet (Se-D and the other group (Se-S was treated with barium selenate

  8. Xylanase production with xylan rich lignocellulosic wastes by a local soil isolate of Trichoderma viride Produção de xilanase com resíduos lignocelulósicos ricos em xilana por uma cepa local de Trichoderma viride isolada de solo

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    Meenakshi Goyal

    2008-09-01

    Full Text Available In the present study, cultural and nutritional conditions for enhanced production of xylanase by a local soil isolate of Trichoderma viride, using various lignocellulosic substrates in submerged culture fermentation have been optimized. Of the lignocellulosics used, maize straw was the best inducer followed by jowar straw for xylanase production. The highest activity achieved was between 14 to 17 days of fermentation. A continuous increase in xylanase production was observed with increasing level of lignocellulosics in the medium and highest activity was observed with maize straw at 5% level. Xylanase production with higher levels of lignocellulosics (3 to 5% of maize, jowar and barseem was found to be higher as compared to that with commercial xylan as carbon source. Sodium nitrate was the best nitrogen source among the six sources used. Maximum xylanase production was achieved with initial medium pH of 3.5-4.0 and incubation temperature of 25ºC.The enzyme preparation was effective in bringing about saccharification of different lignocellulosics. The xylanase production could be further improved by using alkali treated straw as carbon source.Neste estudo, otimizou-se as condições culturais e nutricionais para produção aumentada de xilanase por uma cepa local de Trichoderma viride isolada de solo, empregando-se vários substratos lignocelulósicos, em fermentação submersa. Entre os substratos utilizados, o melhor indutor de produção de xilanase foi palha de milho, seguido de palha de sorgo. A atividade mais alta foi obtida entre 14 e 17 dias de fermentação. Com palha de milho observou-se um aumento contínuo na produção de xilanase com o aumento da concentração dos substratos lignocelulósicos no meio, sendo que a melhor atividade foi obtida com 5% de palha de milho. A produção de xilanase com níveis mais altos de (3 a 5% de milho, sorgo e forragem verde (barseem foi mais levada do que com xilana comercial como fonte de carbono

  9. Isolamento e seleção de fungos causadores da podridão-branca da madeira em florestas de Eucalyptus spp. com potencial de degradação de cepas e raízes Isolation and screening of wood white rot fungi from Eucalyptus spp. forests with potential for use in degradation of stumps and roots

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    Sandra Kunieda de Alonso

    2007-02-01

    Full Text Available Este trabalho objetivou isolar fungos causadores da podridão-branca da madeira, a partir de basidiocarpos e de fragmentos de madeira de eucalipto coletados em várias regiões do país, bem como testar seu potencial de degradação de cepas e raízes mortas em plantios comerciais de eucalipto, após o corte raso. Para o isolamento dos fungos foi desenvolvido um meio de cultura de serragem de eucalipto-ágar. Dentre 292 isolados obtidos e submetidos ao teste de Bavendamm, 144 foram classificados como causadores de podridão-branca, capazes de produzir fenoloxidases. Dentre as nove relações C/N testadas, observou-se uma tendência de ocorrer maior degradação de cavacos naquelas iguais a 60 : 1, 200 : 1 e 300 : 1. Utilizando a relação C/N igual a 60 : 1, realizaram-se dois experimentos para avaliar a degradação de cavacos de Eucalyptus saligna por isolados fúngicos de podridão-branca. No primeiro experimento, avaliado aos 90 dias de incubação, foram selecionados sete isolados, que causaram perda de peso em cavacos superior ou igual à causada por Trametes versicolor, usado para comparação. No segundo experimento foram testados 46 isolados fúngicos. Dentre os mais eficientes estavam os sete isolados selecionados no primeiro teste, além de outros quatro isolados. Baseado na análise de DNA, seis isolados foram identificados, sendo três pertencentes à espécie Pycnoporus sanguineus, um ao gênero Peniophora sp., um ao gênero Pestalotiopsis sp. e um ao gênero Ganoderma sp.The aim of this work was to isolate native wood white-rot fungi from fungal fruit-bodies and eucalyptus wood fragments from different regions of Brazil and to test their potential for degrading dead stumps and roots in Eucalyptus plantings after harvest. Fungi isolates were obtained in a culture medium composed by Eucalyptus sawdust and agar. Among 292 isolates submitted to the Banvedamm test, 144 were classified as phenoloxidases producing isolates. Among nine C

  10. Characterization of a Hepatitis B virus strain in southwestern Paraná, Brazil, presenting mutations previously associated with anti-HBs Resistance Caracterização de uma cepa de hepatite por vírus B no sudoeste do Paraná, Brasil, apresentando mutações previamente associadas à resistência anti-HBs

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    Dennis Armando Bertolini

    2010-02-01

    ça destes aminoácidos, exceto para Serina na posição 114, tem sido relacionada a terapia monoclonal ou policlonal com anti-HBs após transplante de fígado, enquanto a presença da treonina na posição 116 tem sido descrita em crianças imunizadas de Singapura. Este achado demonstra a possível circulação de cepas do HBV resistentes a imunoprofilaxia para hepatite B no Sudoeste do Paraná, Brasil. O genótipo da amostra foi identificado como genótipo D, o qual é frequentemente encontrado na região estudada. Desde que 36% das crianças tinham recebido incompleta ou nenhuma imunoprofilaxia, um seguimento mais intensivo das crianças nascidas de mães AgHBs positivo é necessário.

  11. Suplementación con selenio en vaquillas: Efecto sobre la respuesta inmune a las vacunas Brucella abortus cepa RB51 y toxoide tetánico Selenium suplementation in heifers: Effect on the immune response to Brucella abortus strain RB51 and tetanus toxoid vaccines

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    V Leyán

    2005-01-01

    Full Text Available El trabajo tiene por objetivo evaluar el efecto de una suplementación con selenio (Se sobre la respuesta inmune a las vacunas Toxoide tetánico y Brucella abortus cepa RB51 en vaquillas con un adecuado balance metabólico de selenio (GSH-Px >130 U/g Hb. Para ello se empelaron 32 vaquillas Friesian de 18 a 24 meses de edad, asignadas al azar a dos grupos de 16 animales; uno suplementado (Se-S el día 0 con una dosis de selenato de bario (1 mg Se/kg, s.c., permaneciendo el otro como control no suplementado (No-S. Todas las vaquillas fueron mantenidas durante 9 meses (abril a enero a pastoreo sobre una pradera naturalizada con un contenido de Se de 0,04 ppm/MS. Los animales fueron inmunizados con vacuna RB51 el día 60 y posteriormente con Toxoide tetánico los días 120 y 150. Muestras de sangre fueron obtenidas previo a la suplementación y cada 15 días hasta el término del experimento. El balance metabólico de selenio fue evaluado mediante la actividad sanguínea de Glutatión peroxidasa (GSH-Px. La respuesta inmune humoral se evaluó determinando los anticuerpos séricos específicos para ambos antígenos mediante ELISA y la respuesta inmune celular mediante pruebas de intradermorreacción a antígenos de Brucella abortus. La administración de Se aumentó (P 0,05 en ambos grupos experimentales, mientras que la respuesta celular a la vacuna RB51 fue menor (P The effect of selenium (Se supplementation on the immune response to tetanus toxoid and Brucella abortus strain RB51 vaccines was studied in heifers with a normal Se status (GSH-Px activity > 130 U/g Hb. Frisian heifers (n-32, 18 to 24 months old were randomly allocated into two groups of 16 animals each. Animals from one group were supplemented (Se-S with one dose of barium selenate (1 mg/Se/kg. s.c. on day 0; animals from the other group remained as a control without supplementation (No-S. The heifers grazed during 9 months (April to January a pasture that contained 0.04 ppm/DM of Se

  12. Avaliação do teste de nitrato redutase para a detecção rápida de resistência aos medicamentos de primeira linha em cepas de Mycobacterium tuberculosis isoladas de pacientes em um hospital geral Evaluation of the nitrate reductase assay for the rapid detection of resistance to first-line medications in Mycobacterium tuberculosis strains isolated from patients in a general hospital

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    Maria de Fátima Filardi Oliveira Mansur

    2012-04-01

    Full Text Available Comparamos o teste de nitrato redutase com o método de proporções, considerado como padrão ouro, em 57 cepas de Mycobacterium tuberculosis isoladas de pacientes atendidos no Hospital das Clínicas da Universidade Federal de Minas Gerais, em Belo Horizonte (MG. A sensibilidade, a especificidade e a acurácia para rifampicina e isoniazida foram de 100% para todas, enquanto essas foram, respectivamente, de 88,9%, 66,7% e 96,5% para estreptomicina e de 98,0%, 100% e 98,2% para etambutol. A média de tempo para a obtenção dos resultados foi de dez dias. Na amostra estudada, o teste de nitrato redutase mostrou grande acurácia e excelente concordância com o padrão ouro.We compared the nitrate reductase assay with the proportion method, which is considered the gold standard, in 57 Mycobacterium tuberculosis strains isolated from patients treated at the Federal University of Minas Gerais Hospital das Clínicas, located in the city of Belo Horizonte, Brazil. For rifampin and isoniazid, the sensitivity, specificity, and accuracy of the nitrate reductase assay were all 100%, whereas they were 100%, 88.9%, and 66.7%, respectively, for streptomycin and 98.0%, 100%, and 98.2%, respectively, for ethambutol. The mean time to results was ten days. In the study sample, the nitrate reductase assay proved highly accurate and showed excellent concordance with the gold standard.

  13. Intoxicação experimental por cebola, Allium cepa (Liliaceae, em gatos Experimental onion Allium cepa (Liliaceae poisoning in cats

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    Rafael A. Fighera

    2002-04-01

    Full Text Available A intoxicação por cebola é relatada em várias espécies animais em muitas partes do mundo. O princípio tóxico (n-propil dissulfito presente na cebola causa a transformação da hemoglobina em metemoglobina. Para estudar os achados laboratoriais, de necropsia e histopatológicos da intoxicação por cebola em gatos, cinco gatos de quatro meses de idade receberam cada um uma dose única de 10g/kg de cebola desidratada por via oral. Um outro gato de mesma idade não recebeu a refeição com cebola e serviu como controle. Todos os cinco gatos desenvolveram sinais clínicos da toxicose; um deles morreu dentro de 24 horas após a ingestão da cebola. Os sinais clínicos incluíram apatia, taquicardia, taquipnéia e cianose. Os achados laboratoriais se caracterizavam por anemia hemolítica associada a corpúsculos de Heinz e metemoglobinemia. Os principais achados de necropsia foram esplenomegalia e sangue de cor marrom. Os achados histopatológicos foram hemossiderose e hematopoese extramedular no baço e fígado.Onion poisoning is reported worlwide in several animal species. The toxic principle (n-propyl dissulfide present in onions causes the transformation of hemoglobin in methemoglobin. In order to study the laboratory, gross and histopathological findings in onion poisoning in cats, five 4-month-old cats were fed a single dose of 10g/kg of dried-onion each. Another cat of the same age did not receive the onion meal and served as control. All five cats developed clinical signs of the toxicosis; one of them died within 24 hours of the ingestion of the onion meal. Clinical signs included apathy, tachycardia, tachypnea, and cyanosis. Laboratory findings included hemolytic anemia associated with Heinz bodies and methemoglobinemia. Main necropsy findings were splenomegaly and brown discoloration of blood. Histopathological findings included splenic and hepatic hemosiderosis and multifocal extramedullary hematopoiesis.

  14. Períodos de interferência das plantas daninhas na cultura de cebola (Allium cepa transplantada Periods of weed interference with transplanted onion crop (Allium cepa

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    D.J. Soares

    2003-12-01

    Full Text Available O trabalho foi realizado com o objetivo de estudar os efeitos de períodos de convivência (0, 14, 28, 42, 56, 70, 84 e 98 dias após o transplantio de uma comunidade de plantas daninhas sobre a produtividade de quatro cultivares de cebola (Mercedes, Granex 33, Superex e Serrana, em sistema de transplantio de mudas. O experimento foi instalado em Jaboticabal-SP, de abril a outubro de 2000, utilizando delineamento experimental de blocos ao acaso, quatro repetições, em esquema fatorial 4 x 8. As principais populações de plantas daninhas no final dos períodos de convivência foram de Coronopus didymus, Amaranthus hybridus e Cyperus rotundus. Os cultivares Mercedes (2,90 kgm-2 e Granex 33 (2,64 kgm-2 foram os mais produtivos, independentemente da interferência das plantas daninhas. A convivência com as plantas daninhas durante os primeiros 98 dias reduziu a produtividade da cebola em 95% e o peso médio de bulbos em 91%. O período anterior à interferência (PAI foi de 42 dias, não havendo diferença entre os cultivares de cebola.This research was carried out to evaluate the effects of weed coexistence periods (0, 14, 28, 42, 56, 70, 84 and 98 days after transplanting on the productivity of four onion cultivars (Mercedez, Granex 33, Superex and Serrana. The experiment was installed in Jaboticabal - SP - Brazil, from April to October 2000, arranged in a randomized complete block design, with four replications, in a factorial design 4 x 8. The main weed populations at the end of the coexistence periods were Coronopus didymus, Amaranthus hybridus and Cyperus rotundus. The cultivars Merced