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Sample records for leguminosarum biovar phaseoli

  1. Interacción de Tsukamurella paurometabola C-924 con Rhizobium leguminosarum biovar phaseoli CFH en el cultivo de frijol

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    Marieta Marín Bruzos

    2013-01-01

    Full Text Available En el estudio se evaluaron, mediante análisis de los parámetros fenológicos de las plantas, la interacción de Tsukamurella paurometabola C-924 con Rhizobium leguminosarum biovar phaseoli CFH en el cultivo de frijol. Se emplearon cuatro tratamientos: plantas sin inocular (control, inoculadas con T. paurometabola C-924, inoculadas con R. leguminosarum biovar phaseoli CFH e inoculadas con ambas cepas. Se observaron diferencias significativas (P < 0.01 en los porcentajes de germinación de las plantas tratadas con microorganismos de forma independiente o conjunta con respecto al control sin inocular. Se determinó que la inoculación de T. paurometabola C-924 afectó el proceso de nodulación de R. leguminosarum biovar phaseoli CFH. Sin embargo, esto no incidió de manera significativa en la altura de las plantas ni en el diámetro del tallo, ya que no se encontraron diferencias entre los tratamientos para estos parámetros. Para el número de hojas, los mejores resultados se obtuvieron con la aplicación de T. paurometabola C-924. Se concluyó que la interacción de T. paurometabola C-924 con R. leguminosarum biovar phaseoli CFH en el frijol estimuló significativamente la germinación de las semillas y el número de hojas de las plantas con respecto al control sin inocular. Aunque la aplicación de T. paurometabola C-924 no favoreció la nodulación de R. leguminosarum biovar phaseoli CFH, esto no afectó las características fenológicas del cultivo.

  2. Identification of a NodD repressible gene adjacent to nodM in Rhizobium leguminosarum biovar viciae

    Institute of Scientific and Technical Information of China (English)

    Xiao'er Yang; Bihe Hou; Chenzhi Zong; Guofan Hong

    2012-01-01

    The nodFEL and nodMNT operons in Rhizobium leguminosarum biovar viciae are transcribed in the same orie-tation and induced by NodD in response to flavonoids secreted by legumes.In the narrow intergenic region between nodFEL and nodMNT,we identified a small gene divergently transcribed from nodM to the 3' end of nodL.Unlike the promoters upstream of nodF and nodM,the promoter of this gene is constitutively expressed.It appeared that its promoter might partially overlap with that of nodM and its expression was repressed by nodD.A deletion mutation was made and proteins produced by the mutant were compared with those by wild-type using 2D gel electrophoresis.Several protein differences were identified suggesting that this small gene influences the expression or stability of these proteins.However,the mutant nodulated its host plant (pea) normally.

  3. Immobilization and Survival of Root Nodule Bacterium Rhizobium leguminosarum Biovar viciae / Gumiņbaktērijas Rhizobium leguminosarum biovar viciae imobilizācija un dzīvotspēja

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    Žvagiņa Signe

    2015-11-01

    Full Text Available Rhizobium leguminosarum biovar viciae ir augsnes baktērija, kas spēj veidot gumiņus uz zirņu, pupu, lēcu un vīķu saknēm un saistīt atmosfēras slāpekli simbiozē ar augiem. Gumiņbaktērijas izmanto lauksaimniecībā kā bioloģiskus mēslošanas līdzekļus augu augšanas veicināšanai. Komerciālos gumiņbaktēriju preparātus var iegādāties sausā, šķidrā vai liofilizētā formā. Parasti izmanto sausos sagatavotos mēslošanas līdzekļus uz kūdras bāzes. Šī pētījuma mērķis bija imobilizēt R. leguminosarum un noteikt tās dzīvotspēju šķidrumā un dažādos nesējmateriālos, lai izstrādātu uzlabotus gumiņbaktēriju preparātus. Imobilizēšanai izmantoja piecus sterilizētus materiālus: kūdru, māla pulveri, divu veidu ovālus šūnainās keramikas agregātus un cilindriskas keramikas granulas, kas izgatavotas no Planču depozīta Devona perioda māla. Imobilizāciju veica 2,5 stundu laikā 20 °C temperatūrā. Vēlāk kūdru, pulveri un granulas noberza un sasmalcināja ūdenī ar sterilu piestiņu, lai atdalītu pielipušās baktērijas. Baktēriju kolonijas veidojošo vienību skaitu noteica, izsējot iegūto suspensiju atšķaidījumus Petri traukos ar agarizētu barotni. Dzīvotspēju noteica arī ar LIVE/DEAD epifluorescences metodi. Iegūtie rezultāti parādīja, ka nesējmateriāls ietekmē imobilizācijas sekmes un ka uzglabāšanas temperatūra ietekmē R. leguminosarum dzīvotspēju. Vislabākos rezultātus ieguva, uzglabājot baktērijas suspensijā vai imobilizējot uz kūdras. Rekomendējam uzglabāt R. leguminosarum produktus −18 °C vai 4 °C temperatūrā.

  4. Compatibility of rhizobial genotypes within natural populations of Rhizobium leguminosarum biovar viciae for nodulation of host legumes.

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    Laguerre, Gisèle; Louvrier, Philippe; Allard, Marie-Reine; Amarger, Noëlle

    2003-04-01

    Populations of Rhizobium leguminosarum biovar viciae were sampled from two bulk soils, rhizosphere, and nodules of host legumes, fava bean (Vicia faba) and pea (Pisum sativum) grown in the same soils. Additional populations nodulating peas, fava beans, and vetches (Vicia sativa) grown in other soils and fava bean-nodulating strains from various geographic sites were also analyzed. The rhizobia were characterized by repetitive extragenomic palindromic-PCR fingerprinting and/or PCR-restriction fragment length polymorphism (RFLP) of 16S-23S ribosomal DNA intergenic spacers as markers of the genomic background and PCR-RFLP of a nodulation gene region, nodD, as a marker of the symbiotic component of the genome. Pairwise comparisons showed differences among the genetic structures of the bulk soil, rhizosphere, and nodule populations and in the degree of host specificity within the Vicieae cross-inoculation group. With fava bean, the symbiotic genotype appeared to be the preponderant determinant of the success in nodule occupancy of rhizobial genotypes independently of the associated genomic background, the plant genotype, and the soil sampled. The interaction between one particular rhizobial symbiotic genotype and fava bean seems to be highly specific for nodulation and linked to the efficiency of nitrogen fixation. By contrast with bulk soil and fava bean-nodulating populations, the analysis of pea-nodulating populations showed preferential associations between genomic backgrounds and symbiotic genotypes. Both components of the rhizobial genome may influence competitiveness for nodulation of pea, and rhizosphere colonization may be a decisive step in competition for nodule occupancy.

  5. Rhizobium leguminosarum biovar viciae 3841, deficient in 27-hydroxyoctacosanoate-modified lipopolysaccharide, is impaired in desiccation tolerance, biofilm formation and motility.

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    Vanderlinde, Elizabeth M; Muszynski, Artur; Harrison, Joe J; Koval, Susan F; Foreman, Dallas L; Ceri, Howard; Kannenberg, Elmar L; Carlson, Russell W; Yost, Christopher K

    2009-09-01

    The lipopolysaccharide (LPS) of the Gram-negative legume symbiont Rhizobium leguminosarum biovar viciae 3,841 contains several unique modifications, including the addition of a 27-hydroxyoctacosanoic acid (27OHC28 : 0), also termed the very long chain fatty acid (VLCFA), attached at the 2' position of lipid A. A transposon mutant that lacks expression of two putative 3-oxo-acyl [acyl-carrier protein] synthase II genes, fabF1 and fabF2, from the VLCFA biosynthetic cluster, was isolated and characterized. MS indicated that the lipid A of the mutant lacked the VLCFA modification, and sodium deoxycholate (DOC)-PAGE of the LPS indicated further structural alterations. The mutant was characteristically sensitive to several stresses that would be experienced in the soil environment, such as desiccation and osmotic stresses. An increase in the excretion of neutral surface polysaccharides was observed in the mutant. This mutant was also altered in its attachment to solid surfaces, and was non-motile, with most of the mutant cells lacking flagella. Despite the pleiotropic effects of the mutation, these mutants were still able to nodulate legumes and fix atmospheric nitrogen. This report emphasizes that a structurally intact VLCFA-containing lipid A is critical to cellular traits that are important for survival in the rhizosphere.

  6. Expressão dos genes nod de Rhizobium tropici, R. etli e R. leguminosarum bv. phaseoli e estabelecimento da nodulação do feijoeiro na presença de exsudatos de sementes de Mimosa flocculosa e Leucaena leucocephala

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    F. M. Mercante

    2000-06-01

    Full Text Available Na etapa inicial da troca de sinais moleculares entre macro e microssimbiontes, a interação do feijoeiro e estirpes de Rhizobium tropici, R. etli e R. leguminosarum bv. phaseoli foi avaliada pela expressão dos genes nod de estirpes bacterianas, contendo a fusão nodA::gusA. Esta avaliação foi efetuada por meio da atividade da enzima ß-glucuronidase, utilizando, como indutores, exsudatos liberados pelas sementes de Mimosa flocculosa e Leucaena leucocephala. Além disso, avaliou-se o efeito da adição desses exsudatos no estabelecimento da nodulação do feijoeiro, cv. Carioca. Nos testes "in vitro", a mistura de exsudatos de sementes de feijoeiro e M. flocculosa promoveu aumentos sinergísticos significativos na expressão dos genes nod, tanto das estirpes de R. tropici (CIAT 899/pGUS 32 e F 98.5/pGUS 32 quanto de R. etli (CFN 42/pGUS 32. Em condições controladas, a adição dos exsudatos, tanto de M. flocculosa quanto de L. leucocephala, proporcionou aumento significativo na nodulação inicial do feijoeiro, quando foi inoculada a estirpe CFN 42 (R. etli. A nodulação do feijoeiro cultivado em vasos com solo não foi inibida pelo suprimento de N-mineral, quando se inoculou a estirpe CIAT 899 (R. tropici e foram fornecidos exsudatos de sementes de M. flocculosa.

  7. Characterization of Xanthomonas axonopodis pv. phaseoli isolates

    NARCIS (Netherlands)

    Nunes, W.M.C.; Corazza, M.J.; De Souza, S.A.C.D.; Tsai, S.M.; Kuramae, E.E.

    2008-01-01

    A simple, quick and easy protocol was standardized for extraction of total DNA of the bacteria Xanthomonas axonopodis pv. phaseoli. The DNA obtained by this method had high quality and the quantity was enough for the Random Amplified Polymorphic DNA (RAPD) reactions with random primers, and

  8. Characterization of Xanthomonas axonopodis pv. phaseoli isolates

    NARCIS (Netherlands)

    Nunes, W.M.C.; Corazza, M.J.; De Souza, S.A.C.D.; Tsai, S.M.; Kuramae, E.E.

    2008-01-01

    A simple, quick and easy protocol was standardized for extraction of total DNA of the bacteria Xanthomonas axonopodis pv. phaseoli. The DNA obtained by this method had high quality and the quantity was enough for the Random Amplified Polymorphic DNA (RAPD) reactions with random primers, and Polymera

  9. Bioassay for selection of biocontroller bacteria against bean common blight (Xanthomonas axonopodis pv. phaseoli Bioensaio para seleção de bactérias biocontroladoras do crestamento bacteriano comum do feijão (Xanthomonas axonopodis pv. phaseoli

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    Zarela G.C.N. Zanatta

    2007-09-01

    Full Text Available Emphasis has been given on selection of micro-organism for biological control. However, in order to evaluate the biological control potential of a great number of micro-organisms in a small period of time it is necessary to develop an efficient bioassay. Seven hundred and sixty bacterial isolates from different habitats, were selected for compatibility with Rhizobium leguminosarum bv. phaseoli (SEMIA 4077 e SEMIA 4080. Among them 596 isolates were ineffective against both rhizobia. Bean seeds immersed in suspension of each one of these isolates were agitated for 5 hours at 10ºC and sowed in non-sterilized soil. The plants were kept in greenhouse. After the development of cotyledonary and primary leaves, these were removed and bioassayed for Xanthomonas axonopodis pv. phaseoli (XAP control. In the cotyledonary leaves, it was observed that the isolate DFs093 offered 100% control, DFs041 and DFs1297 offered 90% and DFs490, DFs769, DFs831, DFs842 and DFs843 offered 80% control. In the primary leaves, the DFs482 isolated offered 100% and the DFs080, DFs348, DFs513, DFs622, DFs769, DFs842 and DFs912 offered 80% of XAP control.Tem-se dado muita ênfase ao controle biológico mediante seleção de microorganismos. Porém, para se avaliar o potencial de biocontroladores de forma massal e em pequeno intervalo de tempo é necessário desenvolver um bioensaio eficiente. Bactérias de diferentes sítios, num total de 760 isolados, foram selecionadas para compatibilidade com Rhizobium leguminosarum bv. phaseoli estirpes SEMIA 4077 e SEMIA 4080, onde 596 isolados foram inefetivos contra ambos rizóbios. Sementes de feijão foram imersas em suspensão de cada um destes isolados sendo agitadas por 5 horas a 10ºC, plantadas em solo não esterelizado, sendo as plantas mantidas em casa de vegetação. Após o desenvolvimento das folhas cotiledonares e folhas primárias, estas foram retiradas e avaliadas por bioensaio para o controle de Xanthomonas axonopodis pv

  10. Introduction of the Escherichia coli gdhA gene into Rhizobium phaseoli: effect on nitrogen fixation.

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    Bravo, A; Becerril, B; Mora, J

    1988-01-01

    Rhizobium phaseoli lacks glutamate dehydrogenase (GDH) and assimilates ammonium by the glutamine synthetase-glutamate synthase pathway. A strain of R. phaseoli harboring the Escherichia coli GDH structural gene (gdhA) was constructed. GDH activity was expressed in R. phaseoli in the free-living state and in symbiosis. Nodules with bacteroids that expressed GDH activity had severe impairment of nitrogen fixation. Also, R. phaseoli cells that lost GDH activity and assimilated ammonium by the glutamine synthetase-glutamate synthase pathway preferentially nodulated Phaseolus vulgaris. PMID:2892830

  11. a -Difluoromethylornithine Inhibits the Growth of Fungus Macrophomina phaseoli

    OpenAIRE

    PALAVAN-ÜNSAL, Narçin

    2014-01-01

    a -Difluoromethylornithine (DFMO), a specific enzyme activated inhibitor of ornithine decarboxylase (ODC), significantly inhibited the mycelial growth of the fungus Macrophomina phaseoli (Tassi) Goidanich. Putrescine (Put), when added to the nutrient medium at a concentration of 0.25 mM, decreased the inhibitory effect of DFMO. These results suggest that polyamines (PAs) are essential for the growth of fungi and that DFMO is applicable to the alleviation or prevention of crop losses due to ph...

  12. Reação de genótipos de feijoeiro comum a Fusarium oxysporum f. sp. phaseoli, Macrophomina phaseolina e Xanthomonas campestris pv. phaseoli Behavior of dry bean genotypes to Fusarium oxysporum f. sp. phaseoli, Macrophomina phaseolina, and Xanthomonas campestris pv. phaseoli

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    Antonio Carlos Maringoni

    1999-04-01

    Full Text Available Foi avaliado no presente trabalho o comportamento dos genótipos de feijoeiro (Phaseolus vulgaris L. PI 150414, PI 163117, PI 175829 branco, PI 175829 roxo, PI 175858, PI 197687, A 417, A 420, A 429, Xan 160, Xan 161, WISHBR 40 e IAC Carioca inoculados com Fusarium oxysporum f. sp. phaseoli, Macrophomina phaseolina e Xanthomonas campestris pv. phaseoli, sob condições de telado/casa de vegetação. Verificou-se que os genótipos Xan 160, PI 150414, A 417, PI 175829 roxo, Xan 161, A 420, PI 163117 e PI 175829 branco foram resistentes a F. oxysporum f. sp. phaseoli e somente o PI 175829 branco apresentou bom nível de resistência a M. phaseolina. Com relação ao comportamento desses genótipos a X. campestris pv. phaseoli, eles foram altamente suscetíveis ao isolado Feij-4 e apenas o genótipo Xan 161 apresentou nível moderado de resistência foliar ao isolado Feij-41.The behavior of dry bean (Phaseolus vulgaris L. genotypes PI 150414, PI 163117, PI 175829 white, PI 175829 purple, PI 175858, PI 197687, A 417, A 420, A 429, Xan 160, Xan 161, WISHBR 40, and IAC Carioca inoculated with Fusarium oxysporum f. sp. phaseoli, Macrophomina phaseolina, and Xanthomonas campestris pv. phaseoli was evaluated under greenhouse condition. The bean genotypes Xan 160, PI 150414, A 417, PI 175829 purple, Xan 161, A 420, PI 163117, and PI 175829 white were resistant to F. oxysporum f. sp. phaseoli, and only PI 155829 white had a good level of resistance to M. phaseolina. All bean genotypes were susceptible to Feij-4 strain, and only Xan 161 had some level of leaf resistance to Feij-41 strain of X. campestris pv. phaseoli.

  13. Clavibacter michiganensis subsp. phaseoli subsp. nov., pathogenic in bean.

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    González, Ana J; Trapiello, Estefanía

    2014-05-01

    A yellow Gram-reaction-positive bacterium isolated from bean seeds (Phaseolus vulgaris L.) was identified as Clavibacter michiganensis by 16S rRNA gene sequencing. Molecular methods were employed in order to identify the subspecies. Such methods included the amplification of specific sequences by PCR, 16S amplified rDNA restriction analysis (ARDRA), RFLP and multilocus sequence analysis as well as the analysis of biochemical and phenotypic traits including API 50CH and API ZYM results. The results showed that strain LPPA 982T did not represent any known subspecies of C. michiganensis. Pathogenicity tests revealed that the strain is a bean pathogen causing a newly identified bacterial disease that we name bacterial bean leaf yellowing. On the basis of these results, strain LPPA 982T is regarded as representing a novel subspecies for which the name Clavibacter michiganensis subsp. phaseoli subsp. nov. is proposed. The type strain is LPPA 982T (=CECT 8144T=LMG 27667T).

  14. Interaction of Acidithiobacillus ferrooxidans, Rhizobium phaseoli and Rhodotorula sp. in bioleaching process based on Lotka–Volterra model

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    Xuecheng Zheng

    2016-07-01

    Conclusion: The relationship among microorganisms during leaching could be described appropriately by Lotka–Volterra model between the initial and peak values. The relationship of A. ferrooxidans and R. phaseoli could be considered as mutualism, whereas, the relationship of A. ferrooxidans and R. phaseoli could be considered as commensalism.

  15. Investigation of Ureaplasma urealyticum biovars and their relationship with antimicrobial resistance

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    Zhu Chang-tai

    2011-01-01

    Full Text Available Purpose: To develop Taqman fluorescence quantitative polymerase chain reaction (PCR method for investigating the characteristics of the distributions of Ureaplasma urealyticum (UU biovars and to explore the relationship between UU biovars and antimicrobial resistance. Materials and Methods: By the method of culture, Ureaplasma species were detected. Taqman fluorescence quantitative PCR for detecting UU biovars were developed and UU clinical isolates were detected to distinguish biovars. The broth micro-dilution susceptibility testing methods were used to determine UU susceptibility. Results: By Taqman PCR method, UU biovars was successfully detected. Of 126 samples, biovar 1 was found in 73 (57.94%. There was a statistical difference between genital-urinary tract infection group and asymptomatic group (P<0.05. In the region, UU biovar 1 to 9 kinds of agents kept higher susceptibility rates, but biovar 2 maintained higher susceptibility rates only to tetracyclines. Compared with biovar 1, UU biovar 2 resistance rates to 7 kinds of agents were higher (P<0.05. Conclusions: (1 Our new established Taqman PCR method is a useful tool for screening UU biovars. (2 UU biovar 1 predominated in asymptomatic population; whereas in genital-urinary tract infection population UU biovar 2 had a higher proportion. (3 The characteristics of drug resistance were different between UU biovars. Overall, both two biovars remained higher susceptibility rates to tetracyclines. A majority of biovor 1 strains were sensitive to macrolides and quinolones; while only a small number of biovar 2 strains kept sensitive to roxithromycin and quinolones, a large proportion of biovar 2 strains were found in intermediate ranges.

  16. Pathogenicity of Macrophomina phaseoli on Jute in the Presence of Meloidogyne incognita and Hoplolaimus indicus.

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    Haque, M D; Mukhopadhyaya, M C

    1979-10-01

    Seedlings of Corchorus capsularis (cv. C4444) were inoculated with Meloidogyne incognita, Hoplolaimus indicus, and a fungus pathogen of jute, Macrophomina phaseoli, separately and in all possible combinations. The significant damage of jute plants caused individually by the pathogens was aggravated when the fungus was associated with either of the nematode species. M. incognita alone caused greater damage than either H. indicus or Macrophomina phaseoli alone. Plants inoculated with M. incognita and Macrophomina phaseoli were more severely damaged than plants inoculated with H. indicus and the fungus. Plant growth was minimum and disease symptoms were maximum when all pathogens acted together. In the presence of the fungus, M. incognita produced fewer galls. The reproduction of H. indicus was not influenced by the other organisms.

  17. Diversity of Rhizobium leguminosarum from pea fields in Washington State

    Science.gov (United States)

    Rhizobia-mediated biological nitrogen (N) fixation in legumes contributes to yield potential in these crops and also provides residual fertilizer to subsequent cereals. Our objectives were to collect isolates of Rhizobium leguminosarum from several pea fields in Washington, examine genetic diversity...

  18. The analysis of core and symbiotic genes of rhizobia nodulating Vicia from different continents reveals their common phylogenetic origin and suggests the distribution of Rhizobium leguminosarum strains together with Vicia seeds.

    Science.gov (United States)

    Alvarez-Martínez, Estela R; Valverde, Angel; Ramírez-Bahena, Martha Helena; García-Fraile, Paula; Tejedor, Carmen; Mateos, Pedro F; Santillana, Nery; Zúñiga, Doris; Peix, Alvaro; Velázquez, Encarna

    2009-08-01

    In this work, we analysed the core and symbiotic genes of rhizobial strains isolated from Vicia sativa in three soils from the Northwest of Spain, and compared them with other Vicia endosymbionts isolated in other geographical locations. The analysis of rrs, recA and atpD genes and 16S-23S rRNA intergenic spacer showed that the Spanish strains nodulating V. sativa are phylogenetically close to those isolated from V. sativa and V. faba in different European, American and Asian countries forming a group related to Rhizobium leguminosarum. The analysis of the nodC gene of strains nodulating V. sativa and V. faba in different continents showed they belong to a phylogenetically compact group indicating that these legumes are restrictive hosts. The results of the nodC gene analysis allow the delineation of the biovar viciae showing a common phylogenetic origin of V. sativa and V. faba endosymbionts in several continents. Since these two legume species are indigenous from Europe, our results suggest a world distribution of strains from R. leguminosarum together with the V. sativa and V. faba seeds and a close coevolution among chromosome, symbiotic genes and legume host in this Rhizobium-Vicia symbiosis.

  19. Infestation of Caliothrips phaseoli (Thysanoptera: Thripidae) on Bean Cultivars Grown in the Winter, Rainy, and Dry Seasons in Brazil.

    Science.gov (United States)

    Boiça Júnior, Arlindo Leal; Costa, Eduardo Neves; De Souza, Bruno Henrique Sardinha; Da Silva, Anderson Gonçalves; Chiorato, Alisson Fernando

    2015-08-01

    The present study aimed to identify common bean (Phaseolus vulgaris L.) cultivars less susceptible to Caliothrips phaseoli (Hood) in different growing seasons, to evaluate whether climatic conditions influence plant resistance to C. phaseoli infestation, and to investigate the preferred plant part for insect feeding. Eighteen common bean cultivars were evaluated in the winter season, and 19 cultivars were assessed in the rainy and dry seasons, under field conditions in the municipality of Jaboticabal, state of São Paulo, Brazil. Infestation of C. phaseoli nymphs in the upper and lower parts of the beans plants was recorded at weekly intervals from 25 days after plant emergence (DAE) to 60 DAE. In the winter season, the cultivars 'IAC Galante,' 'IAC Centauro,' 'IAC Carioca Eté,' and 'IAC Formoso' had significantly lower number of thrips than the cultivar 'IAC Diplomata.' In the rainy season, the cultivars 'IAC Harmonia' and 'IPR Siriri' had the lowest thrips infestation, differing from the cultivars 'BRS Pontal' and 'IAC Una.' The bean cultivars were equally susceptible to C. phaseoli in the dry season. The results suggest that C. phaseoli nymphs prefer to infest leaves of the lower part of bean plants, like most generalist herbivorous insects. In the winter and dry seasons, the highest thrips infestation was observed at 60 DAE, while in the rainy season, it was recorded from 32 to 46 DAE. Overall, C. phaseoli infestation on bean cultivars was not influenced by either temperature, relative humidity, or rainfall.

  20. Effect of Naturally Occurring nif Reiterations on Symbiotic Effectiveness in Rhizobium phaseoli

    Science.gov (United States)

    Romero, David; Singleton, Paul W.; Segovia, Lorenzo; Morett, Enrique; Bohlool, B. Ben; Palacios, Rafael; Dávila, Guillermo

    1988-01-01

    Most naturally occurring strains of Rhizobium phaseoli possess reiteration of the nif genes. Three regions contain nitrogenase structural genes in strain CFN42. Two of these regions (a and b) have copies of nifH, nifD, and nifK, whereas the third region (c) contains only nifH. Strains containing mutations in either nif region a or nif region b had significantly diminished symbiotic effectiveness compared with the wild-type strain on the basis of nodule mass, total nitrogenase activity per plant, nitrogenase specific activity, total nitrogen in the shoot, and percentage of nitrogen. A strain containing mutations in both nif region a and nif region b was totally ineffective. These data indicate that both nif region a and nif region b are needed for full symbiotic effectiveness in R. phaseoli. PMID:16347593

  1. Estrategias para diferenciar xanthomonas campestris pv. phaseoli con sales inorgánicas

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    Mildred Zapata

    2001-01-01

    Full Text Available Colonias de Xanthomonas campestris pv. phaseoli (Xcp aisladas de hojas de habichuelas con síntomas de tizón común en Puerto Rico, República Dominicana y Costa Rica fueron caracterizadas como patogénicas en hojas de Phaseolus vulgaris. Sin embargo, éstas fueron clasificadas en los patovares phaseoli, vesicatoria, carotae y xanthosoma por el sistema Biolog. Las cepas de Xcp crecidas en 2, 3, 5-Trifenil cloruro de tetrazolio (TTC mostraron colonias convexas, brillosas, lisas y de color rojo en diferentes tamaños. TTC fue reducido por las cepas de Xcp a un pigmento rojo intenso, un formazán de trifenilo. No se encontraron diferencias en virulencia y tipos de colonias en las cepas identificadas por pruebas de patogenicidad como Xcp. Por otro lado, hubo diferencias en el tipo de colonia en cultivos bacterianos identificados como: Pseudomonas cissicola, P. fulva, Corynebacterium, Rhodococcus, y Shingomonas

  2. Interaction of Meloidogyne javanica and Macrophomina phaseoli in Kenaf Root Rot.

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    Tu, C C; Cheng, Y H

    1971-01-01

    Incidence and severity of root-rot caused by the fungus Macrophomina phaseoli was increased in screenhouse-grown kenaf (Hibiscus cannabinus L.) seedlings simultaneously infected by the nematode Meloidogyne javanica. In seedlings inoculated at 5, 10 and 15 days of age, root rot lesions increased 70.3, 44.1 and 21.8%, and nematode penetration increased 49.0, 36.7, and 12.3% when both fungus and nematode were present.

  3. Danish Rhizobium leguminosarum strains nodulating ‘Afghanistan’ pea (Pisum sativum)

    DEFF Research Database (Denmark)

    Jensen, Erik Steen; Sørensen, Lasse Holst; Engvild, Kjeld Christensen

    1986-01-01

    A wild pea (Pisum sativum L.) native to Afghanistan normally known to be resisant to nodulation with European strains of Rhizobium leguminosarum was nodulated early and effectively in field soil in Denmark. Isolates from nodules formed effective nodules abundantly on 'Afghanistan' on reinfection...... pattern with Rhizobium leguminosarum strains isolated from a modern pea variety cultivated in the same field....

  4. Draft Genome Sequence of Corynebacterium diphtheriae Biovar Intermedius NCTC 5011

    OpenAIRE

    Sangal, Vartul; Nicholas P Tucker; Burkovski, Andreas; Hoskisson, Paul A.

    2012-01-01

    We report an annotated draft genome of the human pathogen Corynebacterium diphtheriae bv. intermedius NCTC 5011. This strain is the first C. diphtheriae bv. intermedius strain to be sequenced, and our results provide a useful comparison to the other primary disease-causing biovars, C. diphtheriae bv. gravis and C. diphtheriae bv. mitis. The sequence has been deposited at DDBJ/EMBL/GenBank with the accession number AJVH01000000.

  5. Draft genome sequence of Corynebacterium diphtheriae biovar intermedius NCTC 5011.

    Science.gov (United States)

    Sangal, Vartul; Tucker, Nicholas P; Burkovski, Andreas; Hoskisson, Paul A

    2012-09-01

    We report an annotated draft genome of the human pathogen Corynebacterium diphtheriae bv. intermedius NCTC 5011. This strain is the first C. diphtheriae bv. intermedius strain to be sequenced, and our results provide a useful comparison to the other primary disease-causing biovars, C. diphtheriae bv. gravis and C. diphtheriae bv. mitis. The sequence has been deposited at DDBJ/EMBL/GenBank with the accession number AJVH01000000.

  6. Identification at biovar level of Brucella isolates causing abortion in small ruminants of iran.

    Science.gov (United States)

    Behroozikhah, Ali Mohammad; Bagheri Nejad, Ramin; Amiri, Karim; Bahonar, Ali Reza

    2012-01-01

    To determine the most prevalent biovar responsible for brucellosis in sheep and goat populations of Iran, a cross-sectional study was carried out over 2 years in six provinces selected based on geography and disease prevalence. Specimens obtained from referred aborted sheep and goat fetuses were cultured on Brucella selective media for microbiological isolation. Brucellae were isolated from 265 fetuses and examined for biovar identification using standard microbiological methods. Results showed that 246 isolates (92.8%) were B. melitensis biovar 1, 18 isolates (6.8%) were B. melitensis biovar 2, and, interestingly, one isolate (0.4%) obtained from Mazandaran province was B. abortus biovar 3. In this study, B. melitensis biovar 3 was isolated in none of the selected provinces, and all isolates from 3 provinces (i.e., Chehar-mahal Bakhtiari, Markazi, and Ilam) were identified only as B. melitensis biovar 1. In conclusion, we found that B. melitensis biovar 1 remains the most prevalent cause of small ruminant brucellosis in various provinces of Iran.

  7. Identification at Biovar Level of Brucella Isolates Causing Abortion in Small Ruminants of Iran

    Directory of Open Access Journals (Sweden)

    Ali Mohammad Behroozikhah

    2012-01-01

    Full Text Available To determine the most prevalent biovar responsible for brucellosis in sheep and goat populations of Iran, a cross-sectional study was carried out over 2 years in six provinces selected based on geography and disease prevalence. Specimens obtained from referred aborted sheep and goat fetuses were cultured on Brucella selective media for microbiological isolation. Brucellae were isolated from 265 fetuses and examined for biovar identification using standard microbiological methods. Results showed that 246 isolates (92.8% were B. melitensis biovar 1, 18 isolates (6.8% were B. melitensis biovar 2, and, interestingly, one isolate (0.4% obtained from Mazandaran province was B. abortus biovar 3. In this study, B. melitensis biovar 3 was isolated in none of the selected provinces, and all isolates from 3 provinces (i.e., Chehar-mahal Bakhtiari, Markazi, and Ilam were identified only as B. melitensis biovar 1. In conclusion, we found that B. melitensis biovar 1 remains the most prevalent cause of small ruminant brucellosis in various provinces of Iran.

  8. Rapid detection and biovar differentiation of Ureaplasma urealyticum in clinical specimens by PCR.

    Science.gov (United States)

    Teng, L J; Ho, S W; Ho, H N; Liaw, S J; Lai, H C; Luh, K T

    1995-07-01

    On the basis of the nucleotide sequence of the multiple-banded (MB) antigen genes of Ureaplasma urealyticum, a polymerase chain reaction (PCR) technique was developed for rapid detection and biovar differentiation of U. urealyticum in a total of 100 urogenital specimens from 50 female patients. Positive PCR UM-1 amplification was found in 28 cervical swabs and 31 urine samples. Overall agreement between PCR and culture was 95%. Members of the two biovars of U. urealyticum could be distinguished by the size of the PCR UM-1 amplification products. Biovar differentiation was also demonstrated by two additional sets of PCRs: PCR UM-2 and UM-3. The PCR UM-2 was used to amplify biovar 1, while PCR UM-3 amplified biovar 2 specifically. The results indicated that use of the MB antigen gene as a target for PCR amplification could provide rapid and specific detection and biotyping of ureaplasma DNA in urogenital samples.

  9. Ultrastructural aspects in perithecia hyphae septal pores of Glomerella cingulata F. SP. Phaseoli

    Directory of Open Access Journals (Sweden)

    Roca M. María Gabriela

    2000-01-01

    Full Text Available Glomerella cingulata (Stonem. Spauld. & Schrenk f. sp. phaseoli, better known in its anamorphic state Colletotrichum lindemuthianum (Sacc. & Magn. Briosi & Cav., is a causal agent of anthracnose in beans (Phaseolus vulgaris L.. Ultrastructural aspects of the perithecial hyphae of this pathogen were studied. The perithecia hyphae septal pores were found either plugged by a vesicle or unplugged. Some perithecia hyphae septa presented no pore. The Woronin bodies, close to the septal pores, appeared as globose structures which were more electron dense than the occlusions plugging the septal pore.

  10. Functional characterization of aroA from Rhizobium leguminosarum with significant glyphosate tolerance in transgenic Arabidopsis.

    Science.gov (United States)

    Han, Jing; Tian, Yong-Sheng; Xu, Jing; Wang, Li-Juan; Wang, Bo; Peng, Ri-He; Yao, Quan-Hong

    2014-09-01

    Glyphosate is the active component of the top-selling herbicide, the phytotoxicity of which is due to its inhibition of the shikimic acid pathway. 5-Enolpyruvylshikimate-3-phosphate synthase (EPSPS) is a key enzyme in the shikimic acid pathway. Glyphosate tolerance in plants can be achieved by the expression of a glyphosate-insensitive aroA gene (EPSPS). In this study, we used a PCR-based two-step DNA synthesis method to synthesize a new aroA gene (aroAR. leguminosarum) from Rhizobium leguminosarum. In vitro glyphosate sensitivity assays showed that aroAR. leguminosarum is glyphosate tolerant. The new gene was then expressed in E. coli and key kinetic values of the purified enzyme were determined. Furthermore, we transformed the aroA gene into Arabidopsis thaliana by the floral dip method. Transgenic Arabidopsis with the aroAR. leguminosarum gene was obtained to prove its potential use in developing glyphosate-resistant crops.

  11. A DNA-Based Procedure for In Planta Detection of Fusarium oxysporum f. sp. phaseoli.

    Science.gov (United States)

    Alves-Santos, Fernando M; Ramos, Brisa; García-Sánchez, M Asunción; Eslava, Arturo P; Díaz-Mínguez, José María

    2002-03-01

    ABSTRACT We have characterized strains of Fusarium oxysporum from common bean fields in Spain that were nonpathogenic on common bean, as well as F. oxysporum strains (F. oxysporum f. sp. phaseoli) pathogenic to common bean by random amplified polymorphic DNA (RAPD) analysis. We identified a RAPD marker (RAPD 4.12) specific for the highly virulent pathogenic strains of the seven races of F. oxysporum f. sp. phaseoli. Sequence analysis of RAPD 4.12 allowed the design of oligonucleotides that amplify a 609-bp sequence characterized amplified region (SCAR) marker (SCAR-B310A280). Under controlled environmental and greenhouse conditions, detection of the pathogen by polymerase chain reaction was 100% successful in root samples of infected but still symptomless plants and in stem samples of plants with disease severity of >/=4 in the Centro Internacional de Agricultura Tropical (CIAT; Cali, Colombia) scale. The diagnostic procedure can be completed in 5 h and allows the detection of all known races of the pathogen in plant samples at early stages of the disease with no visible symptoms.

  12. Cloning of a two-component signal transduction system of Xanthomonas campestris pv. phaseoli var. fuscans strain BXPF65

    DEFF Research Database (Denmark)

    Chan, JWYF; Maynard, Scott; Goodwin, PH

    1998-01-01

    A putative two-component signal transduction system was amplified and cloned from the plant pathogenic bacterium Xanthomonas campestris pv. phaseoli var. fuscans isolate BXPF65. The 620 bp amplified fragment was sequenced and analyzed with the BLAST Enhanced Alignment Utility (BEAUTY). BEAUTY ana...

  13. Characterization and functional analysis of seven flagellin genes in Rhizobium leguminosarum bv. viciae. Characterization of R. leguminosarum flagellins

    Directory of Open Access Journals (Sweden)

    Tambalo Dinah D

    2010-08-01

    Full Text Available Abstract Background Rhizobium leguminosarum bv. viciae establishes symbiotic nitrogen fixing partnerships with plant species belonging to the Tribe Vicieae, which includes the genera Vicia, Lathyrus, Pisum and Lens. Motility and chemotaxis are important in the ecology of R. leguminosarum to provide a competitive advantage during the early steps of nodulation, but the mechanisms of motility and flagellar assembly remain poorly studied. This paper addresses the role of the seven flagellin genes in producing a functional flagellum. Results R. leguminosarum strains 3841 and VF39SM have seven flagellin genes (flaA, flaB, flaC, flaD, flaE, flaH, and flaG, which are transcribed separately. The predicted flagellins of 3841 are highly similar or identical to the corresponding flagellins in VF39SM. flaA, flaB, flaC, and flaD are in tandem array and are located in the main flagellar gene cluster. flaH and flaG are located outside of the flagellar/motility region while flaE is plasmid-borne. Five flagellin subunits (FlaA, FlaB, FlaC, FlaE, and FlaG are highly similar to each other, whereas FlaD and FlaH are more distantly related. All flagellins exhibit conserved amino acid residues at the N- and C-terminal ends and are variable in the central regions. Strain 3841 has 1-3 plain subpolar flagella while strain VF39SM exhibits 4-7 plain peritrichous flagella. Three flagellins (FlaA/B/C and five flagellins (FlaA/B/C/E/G were detected by mass spectrometry in the flagellar filaments of strains 3841 and VF39SM, respectively. Mutation of flaA resulted in non-motile VF39SM and extremely reduced motility in 3841. Individual mutations of flaB and flaC resulted in shorter flagellar filaments and consequently reduced swimming and swarming motility for both strains. Mutant VF39SM strains carrying individual mutations in flaD, flaE, flaH, and flaG were not significantly affected in motility and filament morphology. The flagellar filament and the motility of 3841 strains

  14. Biovar-specific epitopes of the urease enzyme of Ureaplasma urealyticum.

    Science.gov (United States)

    MacKenzie, C R; Henrich, B; Hadding, U

    1996-11-01

    The importance of Ureaplasma urealyticum as a pathogen in premature neonates and patients with a profound defect in humoral immunity has, over the last few years, become well recognised. U. urealyticum is unique amongst the Mycoplasmataceae for its use of urea metabolism as an essential source of energy. The urease enzyme responsible for this is, therefore, of prime importance and any variability in expression of this enzyme may play a role in virulence of the organism. U. urealyticum is divided into 14 serovars comprising two biovars -- the parvo-biovar and T960-biovar. In this study monoclonal antibodies (MAbs) were produced against the urease enzyme. Two distinct epitopes of the 72-kDa alpha-subunit were recognised by three different MAbs. Under denaturing conditions both epitopes were shown to be specific for the parvo-biovar.

  15. Clonal outbreaks of [ Pasteurella] pneumotropica biovar Heyl in two mouse colonies.

    Science.gov (United States)

    Adhikary, Sadhana; Bisgaard, Magne; Dagnæs-Hansen, Frederik; Christensen, Henrik

    2017-01-01

    The aim of this study was to document the pathogenic role of biovar Heyl of [ Pasteurella] pneumotropica in mouse colonies. Fifty-three isolates associated with mastitis and orbital, cutaneous and vaginal abscesses as well as isolates from the nose and vagina of healthy mice were investigated. According to phenotypic characteristics and rpoB sequencing, the isolates were identified as [ P.] pneumotropica biovar Heyl. Pulsed-field gel electrophoresis (PFGE) revealed five closely related profiles separated by only one to four fragments. The outbreak strains diverged from epidemiologically unrelated strains with the same rpoB sequence type, as shown by the PFGE profiles. The investigation documented that members of biovar Heyl of [ P.] pneumotropica caused disease outbreaks in mouse colonies since the clonality indicated a primary role of [ P.] pneumotropica biovar Heyl in the infections observed.

  16. Plaque Formation by and Plaque Cloning of Chlamydia trachomatis Biovar Trachoma

    OpenAIRE

    Matsumoto, Akira; Izutsu, Hiroshi; Miyashita, Naoyuki; Ohuchi, Masanobu

    1998-01-01

    A new technique for the induction of plaque formation by Chlamydia trachomatis biovar trachoma applicable to the titration of infectivity and cloning of biovar trachoma was established. Three novel strains were cloned and confirmed to be free of glycogen inclusions. The lack of glycogen accumulation correlated with the absence of a 7.5-kb plasmid, which is highly conserved in other strains of C. trachomatis. Although the growth efficiency of these plasmid-free strains was slightly lower than ...

  17. Changes of predominant species/biovars and sequence types of Brucella isolates, Inner Mongolia, China.

    Science.gov (United States)

    Chen, Yanfen; Ke, Yuehua; Wang, Yufei; Yuan, Xitong; Zhou, Xiaoyan; Jiang, Hai; Wang, Zhoujia; Zhen, Qing; Yu, Yaqin; Huang, Liuyu; Cui, Buyun; Chen, Zeliang

    2013-11-01

    Human brucellosis incidence in China was divided into 3 stages, high incidence (1950-1960s), decline (1970-1980s) and re-emergence (1990-2000s). Human brucellosis has been reported in all the 32 provinces, of which Inner Mongolia has the highest prevalence, accounting for over 40% of the cases in China. To investigate the etiology alteration of human brucellosis in Inner Mongolia, the species, biovars and genotypes of 60 Brucella isolates from this province were analyzed. Species and biovars of the Brucella strains isolated from outbreaks were determined based on classical identification procedures. Strains were genotyped by multi locus sequence typing (MLST). Sequences of 9 housekeeping genes were obtained and sequence types were defined. The distribution of species, biovars and sequence types (STs) among the three incidence stages were analyzed and compared. The three stages of high incidence, decline and re-emergence were predominated by B. melitensis biovar 2 and 3, B. abortus biovar 3, and B. melitensis biovar 1, respectively, implying changes in the predominant biovars. Genotyping by MLST revealed a total of 14 STs. Nine STs (from ST28 to ST36), accounting for 64.3% of all the STs, were newly defined and different from those observed in other countries. Different STs were distributed among the three stages. ST8 was the most common ST in 1950-1960s and 1990-2000s, while ST2 was the most common in 1970-1980s. The prevalence of biovars and sequence types of Brucella strains from Inner Mongolia has changed over time in the three stages. Compared with those from other countries, new sequence types of Brucella strains exist in China.

  18. Identification at Biovar Level of Brucella Isolates Causing Abortion in Small Ruminants of Iran

    OpenAIRE

    Ali Mohammad Behroozikhah; Ramin Bagheri Nejad; Karim Amiri; Ali Reza Bahonar

    2012-01-01

    To determine the most prevalent biovar responsible for brucellosis in sheep and goat populations of Iran, a cross-sectional study was carried out over 2 years in six provinces selected based on geography and disease prevalence. Specimens obtained from referred aborted sheep and goat fetuses were cultured on Brucella selective media for microbiological isolation. Brucellae were isolated from 265 fetuses and examined for biovar identification using standard microbiological methods. Results show...

  19. Rhizobium leguminosarum bv. viciae populations in soils with increasing heavy metal contamination: abundance, plasmid profiles, diversity and metal tolerance

    NARCIS (Netherlands)

    Lakzian, A.; Murphy, P.; Turner, A.; Beynon, J.L.; Giller, K.E.

    2002-01-01

    Populations of Rhizobium leguminosarum bv. viciae were investigated from plots of a long-term sewage sludge experiment in Braunschweig, Germany, which represented a gradient of increasing metal contamination. The number of R. leguminosarum bv. viciae decreased from 105 cells g¿1 soil in uncontaminat

  20. A lack of genetic basis for biovar differentiation in clinically important Corynebacterium diphtheriae from whole genome sequencing.

    Science.gov (United States)

    Sangal, Vartul; Burkovski, Andreas; Hunt, Alison C; Edwards, Becky; Blom, Jochen; Hoskisson, Paul A

    2014-01-01

    The differentiation of clinically important Corynebacterium diphtheriae into specific biovars is complex and phylogenetically unclear. Comparative genomic analyses of 17 strains indicate that the division of C. diphtheriae into different biovars does not correlate with the variation in the gene content in the relevant metabolic categories that are potentially involved in the biovar discrimination. The biochemical separation is also not supported by phylogenetic analyses, suggesting molecular methods of typing C. diphtheriae strains should be adopted much more widely.

  1. Development of Specific Markers for Identification of Biovars 1 and 2 Strains of Pseudomonas syringae pv. actinidiae

    Directory of Open Access Journals (Sweden)

    Young Sun Lee

    2016-04-01

    Full Text Available Pseudomonas syringae pv. actinidiae, the causal agent of canker in kiwifruit, can be divided into three biovars (biovars 1, 2, and 3. Strains belonging to biovar 1 produce phaseolotoxin and were isolated in Japan and Italy before 2008. Strains of biovar 2 produce coronatine instead of phaseolotoxin and have been isolated only in Korea. Strains belonging to biovar 3 produce neither phaseolotoxin nor coronatine and are responsible for the global outbreak of bacterial canker of kiwifruit in recent years. The biovar 3-specific primer set was developed in a previous work. In this study, two sets of PCR primers specific to strains of biovars 1 and 2, respectively, were developed based on random amplified polymorphic DNA analyses. Primers PsaJ-F and PsaJ-R produced a 481-bp region with genomic DNA of biovar 1 strains, whereas primers PsaK-F and PsaK-R amplified a 413-bp region present only in the genome of biovar 2 strains.

  2. Physiological distinctions of pea symbiotic mutants with various nodulation level under inoculation by Rhizobium leguminosarum

    Directory of Open Access Journals (Sweden)

    Akimova G. P.

    2012-11-01

    Full Text Available The study was focused on morphological and physiological peculiarities of pea plants with various nodulation ability under the infection by Rhizobium leguminosarum. Microscopic studies identified distinct features in formation of root nodules in different pea mutants. We revealed differences in the content of indole-acetic acid (IAA in mutants in the root zones differing by sensibility to R. leguminosarum. It was concluded that hormonal system of plants plays an important role in control of nodulation process, and emergence of mutations inducing disturbance of nodule-forming ability apparently depends on root hormonal status, in particular, IAA concentration ensuring both formation of nodule meristem and further organogenesis of the nodule.

  3. The center for plant and microbial complex carbohydrates at the University of Georgia Complex Carbohydrate Research Center

    Energy Technology Data Exchange (ETDEWEB)

    Albersheim, P.; Darvill, A.

    1991-08-01

    Research from the Complex Carbohydrates Research Center at the University of Georgia is presented. Topics include: Structural determination of soybean isoflavones which specifically induce Bradyrhizobium japonicum nodD1 but not the nodYABCSUIJ operon; structural analysis of the lipopolysaccharides (LPSs) from symbiotic mutants of Bradyrhizobium japonicum; structural characterization of lipooligosaccharides from Bradyrhizobium japonicum that are required for the specific nodulation of soybean; structural characterization of the LPSs from R. Leguminosarum biovar phaseoli, the symbiont of bean; characterization of bacteroid-specific LPS epitopes in R. leguminosarum biovar viciae; analysis of the surface polysaccharides of Rhizobium meliloti mutants whose lipopolysaccharides and extracellular polysaccharides can have the same function in symbiosis; characterization of a polysaccharide produced by certain Bradyrhizobium japonicum strains within soybean nodules; structural analysis of a streptococcal adhesin polysaccharide receptor; conformational studies of xyloglucan, the role of the fucosylated side chain in surface-specific cellulose-xyloglucan interactions; the structure of an acylated glucosamine oligosaccharide signal molecule (nod factor) involved in the symbiosis of Rhizobium leguminosarum biovar viciae with its host Vicia sativa; investigating membrane responses induced by oligogalacturonides in cultured cells; the polygalacturonase inhibitor protein; characterization of the self-incompatability glycoproteins from Petunia hybrida; investigation of the cell wall polysaccharide structures of Arabidopsis thaliana; and the glucan inhibition of virus infection of tabacco.

  4. The center for plant and microbial complex carbohydrates at the University of Georgia Complex Carbohydrate Research Center. Annual report, September 15, 1990--December 31, 1991

    Energy Technology Data Exchange (ETDEWEB)

    Albersheim, P.; Darvill, A.

    1991-08-01

    Research from the Complex Carbohydrates Research Center at the University of Georgia is presented. Topics include: Structural determination of soybean isoflavones which specifically induce Bradyrhizobium japonicum nodD1 but not the nodYABCSUIJ operon; structural analysis of the lipopolysaccharides (LPSs) from symbiotic mutants of Bradyrhizobium japonicum; structural characterization of lipooligosaccharides from Bradyrhizobium japonicum that are required for the specific nodulation of soybean; structural characterization of the LPSs from R. Leguminosarum biovar phaseoli, the symbiont of bean; characterization of bacteroid-specific LPS epitopes in R. leguminosarum biovar viciae; analysis of the surface polysaccharides of Rhizobium meliloti mutants whose lipopolysaccharides and extracellular polysaccharides can have the same function in symbiosis; characterization of a polysaccharide produced by certain Bradyrhizobium japonicum strains within soybean nodules; structural analysis of a streptococcal adhesin polysaccharide receptor; conformational studies of xyloglucan, the role of the fucosylated side chain in surface-specific cellulose-xyloglucan interactions; the structure of an acylated glucosamine oligosaccharide signal molecule (nod factor) involved in the symbiosis of Rhizobium leguminosarum biovar viciae with its host Vicia sativa; investigating membrane responses induced by oligogalacturonides in cultured cells; the polygalacturonase inhibitor protein; characterization of the self-incompatability glycoproteins from Petunia hybrida; investigation of the cell wall polysaccharide structures of Arabidopsis thaliana; and the glucan inhibition of virus infection of tabacco.

  5. Complete Genome Sequence of Campylobacter fetus subsp. venerealis Biovar Intermedius, Isolated from the Prepuce of a Bull.

    Science.gov (United States)

    Iraola, Gregorio; Pérez, Ruben; Naya, Hugo; Paolicchi, Fernando; Harris, David; Lawley, Trevor D; Rego, Natalia; Hernández, Martín; Calleros, Lucía; Carretto, Luis; Velilla, Alejandra; Morsella, Claudia; Méndez, Alejandra; Gioffre, Andrea

    2013-08-01

    Campylobacter fetus subsp. venerealis is the causative agent of bovine genital campylobacteriosis, a sexually transmitted disease distributed worldwide. Campylobacter fetus subsp. venerealis biovar Intermedius strains differ in their biochemical behavior and are prevalent in some countries. We report the first genome sequence for this biovar, isolated from bull prepuce.

  6. Genome sequence of Corynebacterium pseudotuberculosis biovar equi strain 258 and prediction of antigenic targets to improve biotechnological vaccine production

    DEFF Research Database (Denmark)

    Soares, Siomar C; Trost, Eva; Ramos, Rommel T J;

    2013-01-01

    Corynebacterium pseudotuberculosis is the causative agent of several veterinary diseases in a broad range of economically important hosts, which can vary from caseous lymphadenitis in sheep and goats (biovar ovis) to ulcerative lymphangitis in cattle and horses (biovar equi). Existing vaccines ag...

  7. Energy supply for dinitrogen fixation by Azotobacter vinelandii and by bacteroids of Rhizobium leguminosarum

    NARCIS (Netherlands)

    Laane, N.C.M.

    1980-01-01

    The central issue of this thesis is how obligate aerobes, such as Rhizobium leguminosarum bacteroids and Azotobacter vinelandii, generate and regulate the energy supply (in the form of ATP and reducing equivalents) for nitrogenase.In an effective Rhizobium -legume symbiosis, the actual reduction of

  8. Studies on the expression of plasmid-borne genes in the endosymbiotic state of Rhizobium leguminosarum

    NARCIS (Netherlands)

    Krol, A.J.M.

    1982-01-01

    The subject matter of the research reported in this thesis is the role of plasmid-borne genes of Rhizobium in symbiosis and nitrogen fixation. Plasmid DNA was isolated from Rhizobium leguminosarum strain PRE and the expression of plasmid DNA in nitrogen fixing nodules was investigated by hybridizati

  9. Characterization of the nifA regulatory gene of Rhizobium leguminosarum PRE.

    NARCIS (Netherlands)

    Roelvink, P.W.

    1989-01-01

    This thesis describes the characterization of the nif A regulatory gene of the pea endosymbiont Rhizobiumleguminosarum PRE.Chapter I gives a general overview on the regulation of nitrogen fixation in diazotrophs, with special focus on the regulatory NifA pr

  10. Distribution of a Population of Rhizobium leguminosarum bv. trifolii among Different Size Classes of Soil Aggregates†

    OpenAIRE

    Mendes, Ieda C.; Bottomley, Peter J.

    1998-01-01

    A combination of the plant infection-soil dilution technique (most-probable-number [MPN] technique) and immunofluorescence direct count (IFDC) microscopy was used to examine the effects of three winter cover crop treatments on the distribution of a soil population of Rhizobium leguminosarum bv. trifolii across different size classes of soil aggregates (

  11. Rhizoplane colonisation of peas by Rhizobium leguminosarum bv. viceae and a deleterious Pseudomonas putida

    NARCIS (Netherlands)

    Berggren, I.; Alstrom, S.; Vuurde, van J.W.L.; Martensson, A.M.

    2005-01-01

    Pseudomonas putida strain angstrom 313, a deleterious rhizosphere bacterium, reduced pea nitrogen content when inoculated alone or in combination with Rhizobium leguminosarum bv. viceae on plants in the presence of soil under greenhouse conditions. When plants were grown gnotobiotically in liquid me

  12. Classification of physiological races of Fusarium oxysporum f. sp. phaseoli in common bean

    Directory of Open Access Journals (Sweden)

    Francisco Humberto Henrique

    2015-03-01

    Full Text Available Fusarium wilt, caused by Fusarium oxysporum Schlecht. f. phaseoli Kendrick and Snyder (FOP, is a major disease of common bean, causing large economic losses. Genetic resistance is one of the main mechanisms of pathogen control, and knowledge of the physiological variability is fundamental in breeding for resistant cultivars. Thus, a method of pathogen classification that describes the variability and is useful in plant breeding of isolates from different sources was evaluated by different methodologies. Common bean plants of different sets of differentiating cultivars were inoculated with 25 FOP isolates and 3 controls, totaling 28 isolates evaluated 30 days after inoculation. The variability in the isolates found in this study differs from the results of other authors, who reported a small number of physiological races of the pathogen and disagrees with their evaluation of the races and the evaluation methodology. The proposed approach for binary classification based on a group of 12 differentiating cultivars demonstrated that the variability in pathogenicity of FOP is greater than reported so far. By this methodology, 27 different physiological races of the pathogen were obtained. The methods led to contrasting results, with double race classification in the same isolate. The physiological variability found indicates that the physiological races of the pathogen are not limited to 7 as previously mentioned.

  13. Selectable genes for transformation of the fungal plant pathogen Glomerella cingulata f. sp. phaseoli (Colletotrichum lindemuthianum).

    Science.gov (United States)

    Rodriguez, R J; Yoder, O C

    1987-01-01

    Glomerella cingulata f. sp. phaseoli (Gcp) was transformed using either of two selectable markers: the amdS + gene of Aspergillus nidulans, which encodes acetamidase and permits growth on acetamide as the sole nitrogen source and the hygBR gene of Escherichia coli which encodes hygromycin B (Hy) phosphotransferase and permits growth in the presence of the antibiotic Hy. The amdS+ gene functioned in Gcp under control of A. nidulans regulatory signals and hygBR was expressed after fusion to a promoter from Cochliobolus heterostrophus, another filamentous ascomycete. Protoplasts to be transformed were generated with the digestive enzyme complex Novozym 234 and then were exposed to plasmid DNA in the presence of 10 mM CaCl2 and polyethylene glycol. Transformation occurred by integration of single or multiple copies of either the amdS+ or hygBR plasmid into the fungal genome. There was no evidence of autonomous plasmid replication. Transformants were mitotically stable on selective and nonselective media. However, transforming DNA in hygBR transformants was observed to occasionally rearrange during nonselective growth, resulting in fewer copies of the plasmid per genome. These transformants were capable of infecting bean (Phaseolus vulgaris), the Gcp host plant, and after recovery from infected tissue were found to have retained both the transforming DNA unrearranged in their genomes and the Hy resistance phenotype. All single-conidial cultures derived from both amdS+ and hygBR transformants had the transplanted phenotype, suggesting that transformants were homokaryons.

  14. Assessing the Genotypic Differences between Strains of Corynebacterium pseudotuberculosis biovar equi through Comparative Genomics.

    Science.gov (United States)

    Baraúna, Rafael A; Ramos, Rommel T J; Veras, Adonney A O; Pinheiro, Kenny C; Benevides, Leandro J; Viana, Marcus V C; Guimarães, Luís C; Edman, Judy M; Spier, Sharon J; Azevedo, Vasco; Silva, Artur

    2017-01-01

    Seven genomes of Corynebacterium pseudotuberculosis biovar equi were sequenced on the Ion Torrent PGM platform, generating high-quality scaffolds over 2.35 Mbp. This bacterium is the causative agent of disease known as "pigeon fever" which commonly affects horses worldwide. The pangenome of biovar equi was calculated and two phylogenomic approaches were used to identify clustering patterns within Corynebacterium genus. Furthermore, other comparative analyses were performed including the prediction of genomic islands and prophages, and SNP-based phylogeny. In the phylogenomic tree, C. pseudotuberculosis was divided into two distinct clades, one formed by nitrate non-reducing species (biovar ovis) and another formed by nitrate-reducing species (biovar equi). In the latter group, the strains isolated from California were more related to each other, while the strains CIP 52.97 and 1/06-A formed the outermost clade of the biovar equi. A total of 1,355 core genes were identified, corresponding to 42.5% of the pangenome. This pangenome has one of the smallest core genomes described in the literature, suggesting a high genetic variability of biovar equi of C. pseudotuberculosis. The analysis of the similarity between the resistance islands identified a higher proximity between the strains that caused more severe infectious conditions (infection in the internal organs). Pathogenicity islands were largely conserved between strains. Several genes that modulate the pathogenicity of C. pseudotuberculosis were described including peptidases, recombination enzymes, micoside synthesis enzymes, bacteriocins with antimicrobial activity and several others. Finally, no genotypic differences were observed between the strains that caused the three different types of infection (external abscess formation, infection with abscess formation in the internal organs, and ulcerative lymphangitis). Instead, it was noted that there is a higher phenetic correlation between strains isolated at

  15. Assessing the Genotypic Differences between Strains of Corynebacterium pseudotuberculosis biovar equi through Comparative Genomics

    Science.gov (United States)

    Ramos, Rommel T. J.; Veras, Adonney A. O.; Pinheiro, Kenny C.; Benevides, Leandro J.; Edman, Judy M.; Spier, Sharon J.; Azevedo, Vasco; Silva, Artur

    2017-01-01

    Seven genomes of Corynebacterium pseudotuberculosis biovar equi were sequenced on the Ion Torrent PGM platform, generating high-quality scaffolds over 2.35 Mbp. This bacterium is the causative agent of disease known as “pigeon fever” which commonly affects horses worldwide. The pangenome of biovar equi was calculated and two phylogenomic approaches were used to identify clustering patterns within Corynebacterium genus. Furthermore, other comparative analyses were performed including the prediction of genomic islands and prophages, and SNP-based phylogeny. In the phylogenomic tree, C. pseudotuberculosis was divided into two distinct clades, one formed by nitrate non-reducing species (biovar ovis) and another formed by nitrate-reducing species (biovar equi). In the latter group, the strains isolated from California were more related to each other, while the strains CIP 52.97 and 1/06-A formed the outermost clade of the biovar equi. A total of 1,355 core genes were identified, corresponding to 42.5% of the pangenome. This pangenome has one of the smallest core genomes described in the literature, suggesting a high genetic variability of biovar equi of C. pseudotuberculosis. The analysis of the similarity between the resistance islands identified a higher proximity between the strains that caused more severe infectious conditions (infection in the internal organs). Pathogenicity islands were largely conserved between strains. Several genes that modulate the pathogenicity of C. pseudotuberculosis were described including peptidases, recombination enzymes, micoside synthesis enzymes, bacteriocins with antimicrobial activity and several others. Finally, no genotypic differences were observed between the strains that caused the three different types of infection (external abscess formation, infection with abscess formation in the internal organs, and ulcerative lymphangitis). Instead, it was noted that there is a higher phenetic correlation between strains isolated at

  16. Reação de linhagens de feijoeiro ao fungo Fusarium oxysporum f. sp. phaseoli em condições controladas Reaction of common bean lines to Fusarium oxysporum f. sp. phaseoli in controlled conditions

    Directory of Open Access Journals (Sweden)

    Mônica Juliani Zavaglia Pereira

    2011-10-01

    Full Text Available Entre os patógenos que mais contribuem para a redução da produtividade do feijoeiro no Brasil está o Fusarium oxysporum f. sp. phaseoli. O emprego de cultivares resistentes é o controle mais eficaz para esse patógeno. Conduziu-se este trabalho, com o objetivo de avaliar linhagens de feijoeiro (Phaseolus vulgaris L. do banco de germoplasma da Universidade Federal de Lavras (UFLA, quanto a reação ao Fusarium oxysporum f. sp. phaseoli e, ao mesmo tempo, estimar os parâmetros genéticos e fenotípicos que possam auxiliar em futuros programas de melhoramento para esse caráter. Foram avaliadas 367 linhagens em dez experimentos. As testemunhas 'Carioca' (suscetível e 'Carioca MG' (resistente foram utilizadas em todos os experimentos. O delineamento utilizado foi inteiramente ao acaso, com cinco repetições e parcelas de uma planta por vaso. As inoculações foram realizadas segundo a metodologia de corte e imersão de raízes na suspensão de esporos do fungo e as avaliações realizadas aos 21 dias após a inoculação com base no índice de severidade da doença empregando-se notas de 1 (plantas sem sintomas a 9 (plantas mortas.Das linhagens do banco de germoplasma da Universidade Federal de Lavras (UFLA avaliadas, 36,5% foram resistentes ao Fusarium oxysporum f. sp. phaseoli. Entre as resistentes, a maioria foi linhagens obtidas antes de 1990. Das 18 linhagens dos experimentos de VCU, do período de 2005/06, apenas quatro foram suscetíveis. A estimativa da herdabilidade (h² foi elevada (h² = 87%, indicando que, a princípio, o caráter é de fácil seleção.Among the pathogens that most contribute for reducing the productivity of beans in Brazil is the Fusarium oxysporum f. sp. phaseoli. The use of resistant cultivars is the most effective control for this pathogen. The aim of this study was to evaluate germoplasm bean (Phaseolus vulgaris L. lines of the Federal University of Lavras (UFLA as the reaction to the Fusarium oxysporum f

  17. Plaque formation by and plaque cloning of Chlamydia trachomatis biovar trachoma.

    Science.gov (United States)

    Matsumoto, A; Izutsu, H; Miyashita, N; Ohuchi, M

    1998-10-01

    A new technique for the induction of plaque formation by Chlamydia trachomatis biovar trachoma applicable to the titration of infectivity and cloning of biovar trachoma was established. Three novel strains were cloned and confirmed to be free of glycogen inclusions. The lack of glycogen accumulation correlated with the absence of a 7.5-kb plasmid, which is highly conserved in other strains of C. trachomatis. Although the growth efficiency of these plasmid-free strains was slightly lower than that of plasmid-positive strains, possession of the plasmid and glycogen accumulation were not essential for the survival of C. trachomatis.

  18. Variabilidade genética em isolados de Colletotrichum lindemuthianum (Glomerella cingulata f. sp. phaseoli) por meio de marcadores morfológicos

    OpenAIRE

    Souza, Breno Oliveira de

    2014-01-01

    Colletotrichum lindemuthianum (Glomerela cingulata f. sp. phaseoli) apresenta ampla variabilidade genética, demonstrada por suas caracteristicas morfológicas. Este trabalho objetivou caracterizar, por meio de marcadores morfológicos, diferentes isolados (LV4, LV33, LV47, LV51, LV71, LV76, LV77, LV79, LV80, LV81, LV82, LV83, LV84) de C. lindemuthianum (G. cingulata f. sp. phaseoli) e identificar marcadores morfológicos com uso potencial em análises genéticas. Foram avaliados os seguintes carac...

  19. Controle de Rhizoctonia solani e Fusarium oxysporum f.sp. phaseoli por biopreparados de isolados de Trichoderma spp.

    Directory of Open Access Journals (Sweden)

    Pedro Paulo Dias

    2013-12-01

    Full Text Available Os experimentos objetivaram avaliar em condições de casa de vegetação o biocontrole dos fitopatógenos Rhizoctonia solani (RS e Fusarium oxysporum f.sp. phaseoli (FOP em alface (Lactuca sativa L. cultivar Regina, e feijão-vagem (Phaseolus vulgaris L. cultivar Alessa, respectivamente, utilizando como agentes antagonistas, 10 isolados de Trichoderma spp. selecionados em testes in vitro. Foram feitos biopreparados à base de arroz previamente colonizado por isolados de Trichoderma spp. e posteriormente triturados. Para a realização dos testes, os biopreparados foram inoculados previamente na proporção de 10(9 conídios.mL-1, em substrato comercial para produção de mudas. Após sete dias, os patógenos foram introduzidos separadamente em duas concentrações distintas: R. solani na proporção de 144 mg de meio de arroz por kg de substrato e F. oxysporum f.sp. phaseoli inoculado na forma de suspensão contendo 4,75 x 10(6 conídios.mL-1. Avaliou-se a influência dos biopreparados na % de damping-off de pós-emergência em plantas de alface e a severidade de murcha em plantas de feijão-vagem. O biopreparado referente ao isolado T-03 foi o mais eficiente no controle de R. solani em plantas de alface cultivar Regina, por ter reduzido a incidência de damping-off de pós-emergência nessa cultura. Por outro lado, nenhum dos biopreparados apresentou efeito antagonista satisfatório à F. oxysporum f.sp. phaseoli em plantas de feijão-vagem.

  20. Isolation of Rhizobium phaseoli Tn5-induced mutants with altered expression of cytochrome terminal oxidases o and aa3.

    Science.gov (United States)

    Soberón, M; Membrillo-Hernández, J; Aguilar, G R; Sánchez, F

    1990-01-01

    Two Rhizobium phaseoli mutants affected in cytochrome expression were obtained by Tn5-mob mutagenesis of the wild-type strain (CE3). Mutant strain CFN031 expressed sevenfold less cytochrome o in culture, expressed cytochrome aa3 under microaerophilic culture conditions, in contrast to strain CE3, and was affected in its vegetative growth properties and proliferation inside plant host cells. Mutant CFN037 expressed cytochrome aa3 under microaerophilic culture conditions, while bacteroid development and nitrogen fixation occurred earlier than in strain CE3. Images FIG. 2 PMID:2155209

  1. Genotipos de frijol (Phaseolus Vulgaris l. resistentes a Xanthomonas campestris pv. phaseoli de Mexico

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    Rosa Navarrete

    2000-01-01

    Full Text Available Genotipos de frijol (Phaseolus vulgaris L. resistentes a Xanthomonas campestris pv. phaseoli de México. Durante 1995 se evaluó la reacción de genotipos de frijol de diversos origenes a Xcp, bajo condiciones de invernadero en el Campo Experimental del Valle de México, del INIFAP. Se realizaron tres experimentos con a120, b44 y csiete genotipos de frijol. Las plantas se inocularon por corte con navajas en la etapa V3, a y b con una mezcla de nueve cepas de Xcp y el c, con cada una de siete cepas con diferente grado de patogenicidad. La severidad se evaluó 20 días después de la inoculación, por comparación con una escala visual de nueve grados. Los datos se analizaron bajo un diseño completamente al azar. En a, los genotipos que mostraron reacción de resistencia a Xcp fueron: A 36, A 475, G 5686, G 11867, Harowood, SEA 14, XAN 266, MCD 4012 y REN 27. En b los genotipos resistentes fueron: Sequía Durango, Taylor y XAN 30. En los experimentos anteriores la severidad de la enfermedad mostró una distribución normal, con el máximo número de genotipos en el grado de severidad cinco en a y seis en b. Los resultados obtenidos indican que el uso de mezclas de cepas de bacterias con diferente patogenicidad es eficiente para identificar genotipos de frijol resistentes a Xcp. Los genotipos resistentes identificados en el último experimento, mostraron respuesta diferencial e interacciones genotipo por cepa. REN 27 y SEA 14 mostraron resistencia a las cepas utilizadas

  2. Bacterial leaf rot of Aloe vera L., caused byErwinia chrysanthemi biovar 3

    NARCIS (Netherlands)

    Laat, de P.C.A.; Verhoeven, J.T.W.; Danse, J.D.

    1994-01-01

    A severe attack of the bacteriumErwinia chrysantemi biovar 3 on the succulentAloe vera on the Carribean island of Aruba is described. Biochemical and pathological characteristics of strains are presented, including results of successful inoculation experiments onAloe vera. This is the first report

  3. Bacterial leaf rot of Aloe vera L., caused byErwinia chrysanthemi biovar 3

    NARCIS (Netherlands)

    Laat, de P.C.A.; Verhoeven, J.T.W.; Danse, J.D.

    1994-01-01

    A severe attack of the bacteriumErwinia chrysantemi biovar 3 on the succulentAloe vera on the Carribean island of Aruba is described. Biochemical and pathological characteristics of strains are presented, including results of successful inoculation experiments onAloe vera. This is the first report o

  4. A putative genomic island, PGI-1, in Ralstonia solanacearum biovar 2 revealed by subtractive hybridization

    NARCIS (Netherlands)

    Stevens, P.; van Elsas, J.D.

    2010-01-01

    Ralstonia solanacearum biovar 2, a key bacterial pathogen of potato, has recently established in temperate climate waters. On the basis of isolates obtained from diseased (potato) plants, its genome has been assumed to be virtually clonal, but information on environmental isolates has been lacking.

  5. Assessment of Qualitative and Quantitative Characters of Two Persian Clover Ecotypes Inoculated by Rhizobium leguminosarum biovartrifoli and Pesudomonas putida Bacteria

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    R Azamei

    2016-02-01

    Full Text Available Introduction Over the past decades, world attitude has changed towards the reduction of environmental pollutants. Harmful effects of synthetic fertilizers on environment have been identified. Bio-fertilizers are not harmful to the environment, but also they have favorable effects on plant growth processes. Soil biotechnology can be defined as the study of soil organisms and their metabolic processes which may have positive effects on plant yields. The main goal of this study is to asess the biotechnology fertilizers beneficial effects on soil organisms and their subsequently to maximize the yield. It is also our desire conside the soil quality, hygiene and environmental protection along this process. Among the strain of nitrogen-fixing bacteria, symbiotic bacteria such as rhizobium bacteria are important and essential in planning the sustainable farming systems. Several studies have shown that crop varieties which inoculated with rhizobium and pseudomonas were superior in yield production and performance. Material and Methods An experiment was designed as factorial performed in randomized complete block design (RCBD with three replications in Agricultural Research Center of Golpayegan (Isfahan during 2010 – 2011. the purpose of this study was to evaluate the effects of inoculation of two ecotypes of Persian clover by various strains of Rhizobium leguminosarum. Biovar trifoli bacteria accompanied with plant growth promoting rhizobacteria (PGPR Pseudomonas putida was employed to find certain qualitative and quantitative characteristics of clover yield, The main plots included two local ecotypes of Persian clover; Arak Haft Chin (V1 and Isfahan Haft Chin (V2, the subplots included inoculation by two strain of Rhizobium; Rb-3, Rb-13 and one strain of Pseudomonas; PS -168.4 cuts were performed during the experiment and 60 kg/ha seed was used for cultivation based on local knowledge. According to recommendations of the Institute of Soil and Water

  6. Genome sequence of the Trifolium rueppellianum -nodulating Rhizobium leguminosarum bv. trifolii strain WSM2012.

    Science.gov (United States)

    Reeve, Wayne; Melino, Vanessa; Ardley, Julie; Tian, Rui; De Meyer, Sofie; Terpolilli, Jason; Tiwari, Ravi; Yates, Ronald; O'Hara, Graham; Howieson, John; Ninawi, Mohamed; Held, Brittany; Bruce, David; Detter, Chris; Tapia, Roxanne; Han, Cliff; Wei, Chia-Lin; Huntemann, Marcel; Han, James; Chen, I-Min; Mavromatis, Konstantinos; Markowitz, Victor; Szeto, Ernest; Ivanova, Natalia; Mikhailova, Natalia; Pagani, Ioanna; Pati, Amrita; Goodwin, Lynne; Woyke, Tanja; Kyrpides, Nikos

    2013-12-20

    Rhizobium leguminosarum bv. trifolii WSM2012 (syn. MAR1468) is an aerobic, motile, Gram-negative, non-spore-forming rod that was isolated from an ineffective root nodule recovered from the roots of the annual clover Trifolium rueppellianum Fresen growing in Ethiopia. WSM2012 has a narrow, specialized host range for N2-fixation. Here we describe the features of R. leguminosarum bv. trifolii strain WSM2012, together with genome sequence information and annotation. The 7,180,565 bp high-quality-draft genome is arranged into 6 scaffolds of 68 contigs, contains 7,080 protein-coding genes and 86 RNA-only encoding genes, and is one of 20 rhizobial genomes sequenced as part of the DOE Joint Genome Institute 2010 Community Sequencing Program.

  7. Genome sequence of the South American clover-nodulating Rhizobium leguminosarum bv. trifolii strain WSM597.

    Science.gov (United States)

    Reeve, Wayne; Terpolilli, Jason; Melino, Vanessa; Ardley, Julie; Tian, Rui; De Meyer, Sofie; Tiwari, Ravi; Yates, Ronald; O'Hara, Graham; Howieson, John; Ninawi, Mohamed; Held, Brittany; Bruce, David; Detter, Chris; Tapia, Roxanne; Han, Cliff; Wei, Chia-Lin; Huntemann, Marcel; Han, James; Chen, I-Min; Mavromatis, Konstantinos; Markowitz, Victor; Ivanova, Natalia; Ovchinnikova, Galina; Pagani, Ioanna; Pati, Amrita; Goodwin, Lynne; Woyke, Tanja; Kyrpides, Nikos

    2013-12-20

    Rhizobium leguminosarum bv. trifolii strain WSM597 is an aerobic, motile, Gram-negative, non-spore-forming rod isolated from a root nodule of the annual clover Trifolium pallidum L. growing at Glencoe Research Station near Tacuarembó, Uruguay. This strain is generally ineffective for nitrogen (N2) fixation with clovers of Mediterranean, North American and African origin, but is effective on the South American perennial clover T. polymorphum Poir. Here we describe the features of R. leguminosarum bv. trifolii strain WSM597, together with genome sequence information and annotation. The 7,634,384 bp high-quality-draft genome is arranged in 2 scaffolds of 53 contigs, contains 7,394 protein-coding genes and 87 RNA-only encoding genes, and is one of 20 rhizobial genomes sequenced as part of the DOE Joint Genome Institute 2010 Community Sequencing Program.

  8. Genome sequence of the clover-nodulating Rhizobium leguminosarum bv. trifolii strain TA1.

    Science.gov (United States)

    Reeve, Wayne; Tian, Rui; De Meyer, Sofie; Melino, Vanessa; Terpolilli, Jason; Ardley, Julie; Tiwari, Ravi; Howieson, John; Yates, Ronald; O'Hara, Graham; Ninawi, Mohamed; Teshima, Hazuki; Bruce, David; Detter, Chris; Tapia, Roxanne; Han, Cliff; Wei, Chia-Lin; Huntemann, Marcel; Han, James; Chen, I-Min; Mavromatis, Konstantinos; Markowitz, Victor; Ivanova, Natalia; Ovchinnikova, Galina; Pagani, Ioanna; Pati, Amrita; Goodwin, Lynne; Pitluck, Sam; Woyke, Tanja; Kyrpides, Nikos

    2013-12-20

    Rhizobium leguminosarum bv. trifolii strain TA1 is an aerobic, motile, Gram-negative, non-spore-forming rod that is an effective nitrogen fixing microsymbiont on the perennial clovers originating from Europe and the Mediterranean basin. TA1 however is ineffective with many annual and perennial clovers originating from Africa and America. Here we describe the features of R. leguminosarum bv. trifolii strain TA1, together with genome sequence information and annotation. The 8,618,824 bp high-quality-draft genome is arranged in a 6 scaffold of 32 contigs, contains 8,493 protein-coding genes and 83 RNA-only encoding genes, and is one of 20 rhizobial genomes sequenced as part of the DOE Joint Genome Institute 2010 Community Sequencing Program.

  9. Characterization of genes involved in erythritol catabolism in Rhizobium leguminosarum bv. viciae.

    Science.gov (United States)

    Yost, Christopher K; Rath, Amber M; Noel, Tanya C; Hynes, Michael F

    2006-07-01

    A genetic locus encoding erythritol uptake and catabolism genes was identified in Rhizobium leguminosarum bv. viciae, and shown to be plasmid encoded in a wide range of R. leguminosarum strains. A Tn5-B22 mutant (19B-3) unable to grow on erythritol was isolated from a mutant library of R. leguminosarum strain VF39SM. The mutated gene eryF was cloned and partially sequenced, and determined to have a high homology to permease genes of ABC transporters. A cosmid complementing the mutation (pCos42) was identified and was shown to carry all the genes necessary to restore the ability to grow on erythritol to a VF39SM strain cured of pRleVF39f. In the genomic DNA sequence of strain 3841, the gene linked to the mutation in 19B-3 is flanked by a cluster of genes with high homology to the known erythritol catabolic genes from Brucella spp. Through mutagenesis studies, three distinct operons on pCos42 that are required for growth on erythritol were identified: an ABC-transporter operon (eryEFG), a catabolic operon (eryABCD) and an operon (deoR-tpiA2-rpiB) that encodes a gene with significant homology to triosephosphate isomerase (tpiA2). These genes all share high sequence identity to genes in the erythritol catabolism region of Brucella spp., and clustalw alignments suggest that horizontal transfer of the erythritol locus may have occurred between R. leguminosarum and Brucella. Transcription of the eryABCD operon is repressed by EryD and is induced by the presence of erythritol. Mutant 19B-3 was impaired in its ability to compete against wild-type for nodulation of pea plants but was still capable of forming nitrogen-fixing nodules.

  10. Trehalose biosynthesis in Rhizobium leguminosarum bv. trifolii and its role in desiccation tolerance.

    Science.gov (United States)

    McIntyre, Helen J; Davies, Holiday; Hore, Timothy A; Miller, Simon H; Dufour, Jean-Pierre; Ronson, Clive W

    2007-06-01

    Rhizobium leguminosarum bv. trifolii forms nitrogen-fixing root nodules on the pasture legume Trifolium repens, and T. repens seed is often coated with a compatible R. leguminosarum bv. trifolii strain prior to sowing. However, significant losses in bacterial viability occur during the seed-coating process and during storage of the coated seeds, most likely due to desiccation stress. The disaccharide trehalose is known to function as an osmoprotectant, and trehalose accumulation due to de novo biosynthesis is a common response to desiccation stress in bacteria. In this study we investigated the role of endogenous trehalose synthesis in desiccation tolerance in R. leguminosarum bv. trifolii strain NZP561. Strain NZP561 accumulated trehalose as it entered the stationary phase due to the combined actions of the TreYZ and OtsAB pathways. Mutants deficient in either pathway showed near-wild-type levels of trehalose accumulation, but double otsA treY mutants failed to accumulate any trehalose. The double mutants were more sensitive to the effects of drying, and their survival was impaired compared to that of the wild type when glass beads were coated with the organisms and stored at relative humidities of 5 and 32%. The otsA treY mutants were also less competitive for nodule occupancy. Gene expression studies showed that the otsA and treY genes were expressed constitutively and that expression was not influenced by the growth phase, suggesting that trehalose accumulation is controlled at the posttranscriptional level or by control of trehalose breakdown rates. Our results indicate that accumulated trehalose plays an important role in protecting R. leguminosarum bv. trifolii cells against desiccation stress and against stress encountered during nodulation.

  11. Functional and Expression Analysis of the Metal-Inducible dmeRF System from Rhizobium leguminosarum bv. viciae

    Science.gov (United States)

    Rubio-Sanz, L.; Prieto, R. I.; Imperial, J.; Brito, B.

    2013-01-01

    A gene encoding a homolog to the cation diffusion facilitator protein DmeF from Cupriavidus metallidurans has been identified in the genome of Rhizobium leguminosarum UPM791. The R. leguminosarum dmeF gene is located downstream of an open reading frame (designated dmeR) encoding a protein homologous to the nickel- and cobalt-responsive transcriptional regulator RcnR from Escherichia coli. Analysis of gene expression showed that the R. leguminosarum dmeRF genes are organized as a transcriptional unit whose expression is strongly induced by nickel and cobalt ions, likely by alleviating the repressor activity of DmeR on dmeRF transcription. An R. leguminosarum dmeRF mutant strain displayed increased sensitivity to Co(II) and Ni(II), whereas no alterations of its resistance to Cd(II), Cu(II), or Zn(II) were observed. A decrease of symbiotic performance was observed when pea plants inoculated with an R. leguminosarum dmeRF deletion mutant strain were grown in the presence of high concentrations of nickel and cobalt. The same mutant induced significantly lower activity levels of NiFe hydrogenase in microaerobic cultures. These results indicate that the R. leguminosarum DmeRF system is a metal-responsive efflux mechanism acting as a key element for metal homeostasis in R. leguminosarum under free-living and symbiotic conditions. The presence of similar dmeRF gene clusters in other Rhizobiaceae suggests that the dmeRF system is a conserved mechanism for metal tolerance in legume endosymbiotic bacteria. PMID:23934501

  12. Comparative Analysis of Rice Transformation Using Agrobacterium tumefaciens and Rhyzobium leguminosarum

    Directory of Open Access Journals (Sweden)

    Syamsidah Rahmawati

    2015-11-01

    Full Text Available This study was aimed to study the effectiveness of Rhizobium transformation system compared to the most widely used Agrobacterium mediated transformation system on three rice cultivars, Ciherang (Indica, Nipponbare (Japonica, and Rojolele (Javanica. Six day old calli induced from immature embryos were inoculated with Rhizobium leguminosarum bv trifolii ANU845 and Agrobacterium tumefaciens LBA288 that harbored with vector pCAMBIA 5106. This plasmid contained a minimum set of transfer machinery genes and had a gusplus and an hptII gene driven by 35S CaMV promoter in the T-DNA. The results showed that the transformation frequencies (number of PCR positive plants per number of calli inoculated ranging from 0 to 12.05 % depend on the genotype and transfer agent used. The highest transformation frequency (12.05% was obtained in Ciherang transformed with R. leguminosarum. Most of the transgenic rice obtainedby Rhizobium transformation were normal in morphology and fertile similar to those obtained by Agrobacterium transformation. Integration, expression and inheritance of transgenes were demonstrated by molecular and genetic analysis in T0 and T1 generations.Key words : Rhizobium leguminosarum, immature embryos, Agrobacterium tumefaciens

  13. Characterization of the urease gene cluster from Rhizobium leguminosarum bv. viciae.

    Science.gov (United States)

    Toffanin, Annita; Cadahia, Esther; Imperial, Juan; Ruiz-Argüeso, Tomás; Palacios, Manuel

    2002-04-01

    Moderate levels of urease activity (ca. 300 mU mg(-1)) were detected in Rhizobium leguminosarum bv. viciae UPM791 vegetative cells. This activity did not require urea for induction and was partially repressed by the addition of ammonium into the medium. Lower levels of urease activity (ca. 100 mU mg(-1)) were detected also in pea bacteroids. A DNA region of ca. 9 kb containing the urease structural genes ( ureA, ureB and ureC), accessory genes ( ureD, ureE, ureF, and ureG), and five additional ORFs ( orf83, orf135, orf207, orf223, and orf287) encoding proteins of unknown function was sequenced. Three of these ORFs ( orf83, orf135 and orf207) have a homologous counterpart in a gene cluster from Sinorhizobium meliloti, reported to be involved in urease and hydrogenase activities. R. leguminosarum mutant strains carrying Tn 5 insertions within this region exhibited a urease-negative phenotype, but induced wild-type levels of hydrogenase and nitrogenase activities in bacteroids. orf287 encodes a potential transmembrane protein with a C-terminal GGDEF domain. A mutant affected in orf287 exhibited normal levels of urease activity in culture cells. Experiments aimed at cross-complementing Ni-binding proteins required for urease and hydrogenase synthesis (UreE and HypB, respectively) indicated that these two proteins are not functionally interchangeable in R. leguminosarum.

  14. Study on the Response of some Solanaceous Plants to Ralstonia solanacearum Biovars 2A and 2T

    Directory of Open Access Journals (Sweden)

    Vahideh Hasabi

    2014-09-01

    Full Text Available Ralstonia solanacearum is a very destructive bacterial plant pathogen that causes wilt disease in solanaceae crops. To study the response of potato, tomato, eggplant and petunia to bacterial wilt disease, two isolates representing biovars 2A and 2T of R. solanacearum were evaluated for their pathogenicity aggressiveness and tobacco hypersensitivity response (HR at two different temperature regimes. The response of plants was estimated by appearance of wilting symptoms and bacterial density in the xylems of inoculated plants over a four weeks period. The results indicated that isolates representing biovar 2T caused less disease in all the species and cultivars compared to isolates biovar 2A, at both temperature conditions and also, there were significant differences in susceptibility to biovars 2A and 2T of R. solanacearum among tomato, eggplant and petunia and potato cultivars.

  15. Infestação de Bemisia tabaci biótipo B e Caliothrips phaseoli em genótipos de feijoeiro Infestation of Bemisia tabaci biotype B and Caliothrips phaseoli on bean genotypes

    Directory of Open Access Journals (Sweden)

    Flávio Gonçalves de Jesus

    2010-01-01

    Full Text Available Avaliou-se o comportamento de genótipos de feijoeiro sob a infestação de Bemisia tabaci (Genn. biótipo B e Caliothrips phaseoli (Hood em condições de campo, nas épocas de cultivo "de inverno", "das águas" e "da seca". Adotou-se o delineamento de blocos casualizados em esquema de parcelas sub-subdividida (19x3x6, com 19 genótipos (IAC Tybatã, IAC Una, FT Nobre, Pérola, Gen 96A98-15-3-32-1, Gen 96A45-3-51-52-1, IAC Alvorada, IAC Diplomata, Gen 96A3-P1-1-1, LP 98-122, LP 02-130, LP 01-38, LP 9979, BRS-Pontal, BRS-Requinte, BRS-Triunfo, BRS-Grafite, CV-48 e Z-28, três épocas de cultivos (inverno, águas e seca e seis períodos de avaliação. As avaliações foram realizadas semanalmente, contando-se o número de ovos e ninfas de B. tabaci e ninfas de C. phaseoli em dez folíolos por parcela. Os genótipos IAC Una, Pérola, Gen 96A45-3-51-52-1, Gen 96A98-15-32-1, FT Nobre, IAC Tybatã, IAC Alvorada, LP 02-130, LP 01-38, LP 98-122, IAC Diplomata e Gen 96A3P1-1-1 foram menos ovipositados por B. tabaci no cultivo "das águas". Os genótipos Pérola, Gen 96A45-3-51-52-1, IAC Una, Gen 96A98-15-32-1, IAC Tybatã e FT Nobre foram menos infestados por C. phaseoli. A maior incidência de ninfas de mosca-branca ocorreu no fim de janeiro no cultivo "das águas" e início de maio no cultivo "da seca"; para tripés, foi em junho durante o cultivo "de inverno". A maior incidência da população de B. tabaci e C. phaseoli, ocorreu dos 46 aos 60 dias após a emergência das plantas.The response of bean genotypes to infestation of Bemisia tabaci (Genn. biotype B and Caliothrips phaseoli (Hood in field conditions on the winter, rainy and dry seasons was evaluated. The experiment was arranged in a randomized Sub-divided (19x3x6 blocks design with 19 genotypes (IAC Tybatã, IAC Una, FT Nobre, Pérola, Gen 96A98-15-3-32-1, Gen 96A45-3-51-52-1, IAC Alvorada, IAC Diplomata, Gen 96A3-P1-1-1, LP 98-122, LP 02-130, LP 01-38, LP 9979, BRS-Pontal, BRS

  16. Emended description of Campylobacter sputorum and revision of its infrasubspecific (biovar) divisions, including C-sputorum biovar paraureolyticus, a urease-producing variant from cattle and humans

    DEFF Research Database (Denmark)

    On, S.L.W.; Atabay, H.I.; Corry, J.E.L.;

    1998-01-01

    A polyphasic taxonomic study of 15 bovine and human strains assigned to the catalase-negative, urease-positive campylobacter (CNUPC) group identified these bacteria as a novel, ureolytic biovar of Campylobacter sputorum for which we propose the name C. sputorum bv. paraureolyticus: suitable...... should be revised to include by. sputorum for catalase-negative strains; by. fecalis for catalase-positive strains; and by. paraureolyticus for urease-positive strains. Strains classified previously as by. bubulus should be reclassified as by. sputorum. The species description of C. sputorum is revised...

  17. The pan-genome of the animal pathogen Corynebacterium pseudotuberculosis reveals differences in genome plasticity between the biovar ovis and equi strains.

    Directory of Open Access Journals (Sweden)

    Siomar C Soares

    Full Text Available Corynebacterium pseudotuberculosis is a facultative intracellular pathogen and the causative agent of several infectious and contagious chronic diseases, including caseous lymphadenitis, ulcerative lymphangitis, mastitis, and edematous skin disease, in a broad spectrum of hosts. In addition, Corynebacterium pseudotuberculosis infections pose a rising worldwide economic problem in ruminants. The complete genome sequences of 15 C. pseudotuberculosis strains isolated from different hosts and countries were comparatively analyzed using a pan-genomic strategy. Phylogenomic, pan-genomic, core genomic, and singleton analyses revealed close relationships among pathogenic corynebacteria, the clonal-like behavior of C. pseudotuberculosis and slow increases in the sizes of pan-genomes. According to extrapolations based on the pan-genomes, core genomes and singletons, the C. pseudotuberculosis biovar ovis shows a more clonal-like behavior than the C. pseudotuberculosis biovar equi. Most of the variable genes of the biovar ovis strains were acquired in a block through horizontal gene transfer and are highly conserved, whereas the biovar equi strains contain great variability, both intra- and inter-biovar, in the 16 detected pathogenicity islands (PAIs. With respect to the gene content of the PAIs, the most interesting finding is the high similarity of the pilus genes in the biovar ovis strains compared with the great variability of these genes in the biovar equi strains. Concluding, the polymerization of complete pilus structures in biovar ovis could be responsible for a remarkable ability of these strains to spread throughout host tissues and penetrate cells to live intracellularly, in contrast with the biovar equi, which rarely attacks visceral organs. Intracellularly, the biovar ovis strains are expected to have less contact with other organisms than the biovar equi strains, thereby explaining the significant clonal-like behavior of the biovar ovis

  18. Duplex PCR for differentiation of the vaccine strain Brucella suis S2 and B. suis biovar 1 from other strains of Brucella spp.

    Science.gov (United States)

    Nan, Wenlong; Tan, Pengfei; Wang, Yong; Xu, Zouliang; Mao, Kairong; Peng, Daxin; Chen, Yiping

    2014-09-01

    Immunisation with attenuated Brucella spp. vaccines prevents brucellosis, but may also interfere with diagnosis. In this study, a duplex PCR was developed to distinguish Brucella suis vaccine strain S2 from field strains of B. suis biovar 1 and other Brucella spp. The PCR detected 60 fg genomic DNA of B. suis S2 or biovar 1 field strains and was able to distinguish B. suis S2 and wild-type strains of B. suis biovar 1 among 76 field isolates representing all the common species and biovars, as well as four vaccine strains, of Brucella.

  19. Freqüência de biovares de Ralstonia solanacearum em diferentes cultivares e épocas de cultivo de batata no Rio Grande do Sul

    OpenAIRE

    Maciel, Joao Leodato Nunes; Duarte, Valmir; Silveira,José Ricardo Pfeifer; Van der Sand, Sueli Terezinha

    2001-01-01

    A presença das biovares I e/ou II de Ralstonia solanacearum em uma lavoura de batatas (Solanum tuberosum) tem influência direta no sucesso das medidas adotadas para controlar a murcha bacteriana. As biovares diferem entre si em relação à agressividade, latência e sobrevivência. Assim, um experimento de campo foi conduzido em uma área naturalmente infestada em duas épocas de cultivo com os objetivos de verificar (1) a incidência de biovares I e/ou II, (2) a relação entre biovar e época de plan...

  20. Effect of disturbance of the gastrointestinal microflora on the faecal excretion of Fusobacterium necrophorum biovar A.

    OpenAIRE

    Smith, G. R.; Thornton, E. A.

    1993-01-01

    Oral pretreatment of mice with either a mixture of kanamycin and erythromycin or metronidazole to modify the gut microflora greatly enhanced the faecal excretion of Fusobacterium necrophorum biovar A given by mouth. This lends support to the suggestion that disturbance of the gastrointestinal microflora in animals such as cattle, which often carry the organism in the rumen, may lead to intestinal multiplication and faecal excretion, thereby providing a source of infection that may lead to nec...

  1. Imunidade de aves (Gallus gallus) para Salmonella enterica subesp. enterica Sorovar Gallinarum biovar Gallinarum

    OpenAIRE

    Acelas Díaz, Silvia Juliana [UNESP

    2014-01-01

    The fowl typhoid is a systemic disease of chickens caused by Salmonella enteric subsp. enteric serovar Gallinarum biovar Gallinarum. This bacterium is highly pathogenic for chickens at any age, causing mortality even in adult birds. The progress of clinical signs differs among different lines of chickens. White lines of chickens are considered resistant and hardly mortality is observed. Chickens of brown lines are more susceptible and develop severe clinical signs with high mortality rates. T...

  2. Extracción de adn plasmidico de cepas de rhizobium leguminosarum

    Directory of Open Access Journals (Sweden)

    M. Y, Cortés L.

    2010-07-01

    Full Text Available S.e realizó una comparación simultánea de cuatro métodos para la extracción de ADN plasmídico. De los resultados experimentales se concluyó que únicamente con la técnica de Kronstad, en las condiciones ensayadas y con cultivos de cepas de Rhizobium leguminosarum bv Viceae en fase de crecimiento logarítmica temprana, se visualizaron 3 plásmidos para la cepa SEMIA 335 y un plásmido para la cepa B.

  3. Extracción de adn plasmidico de cepas de rhizobium leguminosarum

    OpenAIRE

    2010-01-01

    S.e realizó una comparación simultánea de cuatro métodos para la extracción de ADN plasmídico. De los resultados experimentales se concluyó que únicamente con la técnica de Kronstad, en las condiciones ensayadas y con cultivos de cepas de Rhizobium leguminosarum bv Viceae en fase de crecimiento logarítmica temprana, se visualizaron 3 plásmidos para la cepa SEMIA 335 y un plásmido para la cepa B.

  4. Symbiotic Autoregulation of nifA Expression in Rhizobium leguminosarum bv. viciae

    OpenAIRE

    Martínez, Marta; Palacios, José M.; Imperial, Juan; Ruiz-Argüeso, Tomás

    2004-01-01

    NifA is the general transcriptional activator of nitrogen fixation genes in diazotrophic bacteria. In Rhizobium leguminosarum bv. viciae UPM791, the nifA gene is part of a gene cluster (orf71 orf79 fixW orf5 fixABCX nifAB) separated by 896 bp from an upstream and divergent truncated duplication of nifH (ΔnifH). Symbiotic expression analysis of genomic nifA::lacZ fusions revealed that in strain UPM791 nifA is expressed mainly from a σ54-dependent promoter (PnifA1) located upstream of orf71. Th...

  5. Effects of microgravity on the binding of acetylsalicylic acid by Rhizobium leguminosarum bv. trifolii

    Science.gov (United States)

    Urban, James E.; Gerren, Richard; Zoelle, Jeffery

    1995-07-01

    Bacteroids can be induced in vitro by treating growing Rhizobium leguminosarum bv. trifolii with succinic acid or succinic acid structural analogs like acetylsalicylic acid. Quantitating bacteroid induction by measuring acetylsalicylic binding under normal (1 g) conditions showed two forms of binding to occur. In one form of binding cells immediately bound comparatively high levels of acetylsalicylic acid, but the binding was quickly reversed. The second form of binding increased with time by first-order kinetics, and reached saturation in 40 s. Similar experiments performed in the microgravity environment aboard the NASA 930 aircraft showed only one form of binding and total acetylsalicylic acid bound was 32% higher than at 1 g.

  6. Genome sequencing reveals a new lineage associated with lablab bean and genetic exchange between Xanthomonas axonopodis pv. phaseoli and Xanthomonas fuscans subsp. fuscans

    Directory of Open Access Journals (Sweden)

    Valente eAritua

    2015-10-01

    Full Text Available Common bacterial blight is a devastating seed-borne disease of common beans that also occurs on other legume species including lablab and Lima beans. We sequenced and analysed the genomes of 26 isolates of Xanthomonas axonopodis pv. phaseoli and X. fuscans subsp. fuscans, the causative agents of this disease, collected over four decades and six continents. This revealed considerable genetic variation within both taxa, encompassing both single-nucleotide variants and differences in gene content, that could be exploited for tracking pathogen spread. The bacterial isolate from Lima bean fell within the previously described Genetic Lineage 1, along with the pathovar type isolate (NCPPB 3035. The isolates from lablab represent a new, previously unknown genetic lineage closely related to strains of X. axonopodis pv. glycines. Finally, we identified more than 100 genes that appear to have been recently acquired by Xanthomonas axonopodis pv. phaseoli from X. fuscans subsp. fuscans.

  7. Typing Discrepancy Between Phenotypic and Molecular Characterization Revealing an Emerging Biovar 9 Variant of Smooth Phage-Resistant B. abortus Strain 8416 in China.

    Science.gov (United States)

    Kang, Yao-Xia; Li, Xu-Ming; Piao, Dong-Ri; Tian, Guo-Zhong; Jiang, Hai; Jia, En-Hou; Lin, Liang; Cui, Bu-Yun; Chang, Yung-Fu; Guo, Xiao-Kui; Zhu, Yong-Zhang

    2015-01-01

    A newly isolated smooth colony morphology phage-resistant strain 8416 isolated from a 45-year-old cattle farm cleaner with clinical features of brucellosis in China was reported. The most unusual phenotype was its resistance to two Brucella phages Tbilisi and Weybridge, but sensitive to Berkeley 2, a pattern similar to that of Brucella melitensis biovar 1. VITEK 2 biochemical identification system found that both strain 8416 and B. melitensis strains shared positive ILATk, but negative in other B. abortus strains. However, routine biochemical and phenotypic characteristics of strain 8416 were most similar to that of B. abortus biovar 9 except CO2 requirement. In addition, multiple PCR molecular typing assays including AMOS-PCR, B. abortus special PCR (B-ab PCR) and a novel sub-biovar typing PCR, indicated that strain 8416 may belong to either biovar 3b or 9 of B. abortus. Surprisingly, further MLVA typing results showed that strain 8416 was most closely related to B. abortus biovar 3 in the Brucella MLVA database, primarily differing in 4 out of 16 screened loci. Therefore, due to the unusual discrepancy between phenotypic (biochemical reactions and particular phage lysis profile) and molecular typing characteristics, strain 8416 could not be exactly classified to any of the existing B. abortus biovars and might be a new variant of B. abortus biovar 9. The present study also indicates that the present phage typing scheme for Brucella sp. is subject to variation and the routine Brucella biovar typing needs further studies.

  8. Genetic diversity of indigenous Rhizobium leguminosarum bv. viciae isolates nodulating two different host plants during soil restoration with alfalfa.

    Science.gov (United States)

    Zhang, X X; Kosier, B; Priefer, U B

    2001-09-01

    A total of 360 Rhizobium leguminosarum bv. viciae strains was isolated from three brown-coal mining restoration fields of different age and plant cover (without and in the first and second year of alfalfa, Medicago sativa, cultivation) using two host species (Vicia hirsuta and Pisum sativum) as capture plants. The strains were genetically typed by restriction fragment length polymorphism analysis of polymerase chain reaction (PCR)-generated 16S-23S ribosomal DNA intergenic spacer regions (IGS-RFLP) and characterized by plasmid profiles and RFLP analysis of amplified nodABC genes. The R. leguminosarum bv. viciae population was dominated by the same group of strains (irrespective of the trap plant used). According to type richness, the genetic diversity of indigenous R. leguminosarum in the second year of restoration was lower than in the first year and it resembled that of the fallow field, except for plasmid types, in which it was higher than that of the fallow field. Some of the less frequent nodABC genotypes were associated with distinct chromosomal IGS genotypes and symbiotic plasmids (pSyms) of different sizes, indicating that horizontal transfer and rearrangements of pSym can occur in natural environments. However, the dominant pSym and chromosomal genotypes were strictly correlated suggesting a genetically stable persistence of the prevailing R. leguminosarum bv. viciae genotypes in the absence of its host plant.

  9. A Rhizobium leguminosarum CHDL- (Cadherin-Like-) Lectin Participates in Assembly and Remodeling of the Biofilm Matrix

    DEFF Research Database (Denmark)

    Vozza, Nicolás F.; Abdian, Patricia L; Russo, Daniela M

    2016-01-01

    important advances were made in the identification of the genetic and extracellular factors required for biofilm formation, the mechanisms leading to biofilm matrix assembly, and the roles of extracellular proteins in these processes are still poorly understood. The symbiont Rhizobium leguminosarum requires...

  10. Rhizobium leguminosarum exoB mutants are deficient in the synthesis of UDP-glucose 4'-epimerase

    NARCIS (Netherlands)

    CREMERS, HCJC; Batley, M; Redmond, J W; Eijdems, Elisabeth; BREEDVELD, MW; ZEVENHUIZEN, LPTM; Pees, Elisabeth; Wijffelman, C A; Lugtenberg, Ben J.J.

    1990-01-01

    Rhizobium leguminosarum bv. viciae Exo- mutant strains RBL5523,exo7::Tn5,RBL5523,exo8::Tn5 and RBL5523,exo52::Tn5 are affected in nodulation and in the syntheses of lipopolysaccharide, capsular polysaccharide, and exocellular polysaccharide. These mutants were complemented for nodulation and for the

  11. Genetic diversity of indigenous Rhizobium leguminosarum bv. viciae isolates nodulating two different host plants during soil restoration with alfalfa

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, X.X.; Kosier, B.; Priefer, U.B. [Rheinisch-Westfaelische TH Aachen, Aachen (Germany)

    2001-09-01

    A total of 360 Rhizobium leguminosarum bv. viciae strains was isolated from three brown-coal mining restoration fields of different age and plant cover (without and in the first and second year of alfalfa, Medicago sativa, cultivation) using two host species (Vicia hirsuta and Pisum sativum) as capture plants. The strains were genetically typed by restriction fragment length polymorphism analysis of polymerase chain reaction (PCR)-generated 16S-23S ribosomal DNA intergenic spacer regions (IGS-RFLP) and characterized by plasmid profiles and RFLP analysis of amplified nodABC genes. The R. leguminosarum bv. viciae population was dominated by the same group of strains (irrespective of the trap plant used). According to type richness, the genetic diversity of indigenous R. leguminosarum in the second year of restoration was lower than in the first year and it resembled that of the fallow field, except for plasmid types, in which it was higher than that of the fallow field. Some of the less frequent nodABC genotypes were associated with distinct chromosomal IGS genotypes and symbiotic plasmids (pSyms) of different sizes, indicating that horizontal transfer and rearrangements of pSym can occur in natural environments. However, the dominant pSym and chromosomal genotypes were strictly correlated suggesting a genetically stable persistence of the prevailing R. leguminosarum bv, viciae genotypes in the absence of its host plant.

  12. Transfer and loss of naturally-occuring plasmids among isolates of Rhizobium leguminosarum bv. viciae in heavy metal contaminated soils

    NARCIS (Netherlands)

    Lakzian, A.; Murphy, P.J.; Giller, K.E.

    2007-01-01

    Plasmid transfer among isolates of Rhizobium leguminosarum bv. viciae in heavy metal contaminated soils from a long-term experiment in Braunschweig, Germany, was investigated under laboratory conditions. Three replicate samples each of four sterilized soils with total Zn contents of 54, 104, 208 and

  13. Root Exudates of Various Host Plants of Rhizobium leguminosarum Contain Different Sets of Inducers of Rhizobium Nodulation Genes.

    Science.gov (United States)

    Zaat, S A; Wijffelman, C A; Mulders, I H; van Brussel, A A; Lugtenberg, B J

    1988-04-01

    Rhizobium promoters involved in the formation of root nodules on leguminous plants are activated by flavonoids in plant root exudate. A series of Rhizobium strains which all contain the inducible Rhizobium leguminosarum nodA promoter fused to the Escherichia coli lacZ gene, and which differ only in the source of the regulatory nodD gene, were recently used to show that the regulatory nodD gene determines which flavonoids are able to activate the nodA promoter (HP Spaink, CA Wijffelman, E Pees, RJH Okker, BJJ Lugtenberg 1987 Nature 328: 337-340). Since these strains therefore are able to discriminate between various flavonoids, they were used to determine whether or not plants that are nodulated by R. leguminosarum produce different inducers. After chromatographic separation of root exudate constituents from Vicia sativa L. subsp. nigra (L.), V. hirsuta (L.) S.F. Gray, Pisum sativum L. cv Rondo, and Trifolium subterraneum L., the fractions were tested with a set of strains containing a nodD gene of R. leguminosarum, R. trifolii, or Rhizobium meliloti, respectively. It appeared that the source of nodD determined whether, and to what extent, the R. leguminosarum nodA promoter was induced. Lack of induction could not be attributed to the presence of inhibitors. Most of the inducers were able to activate the nodA promoter in the presence of one particular nodD gene only. The inducers that were active in the presence of the R. leguminosarum nodD gene were different in each root exudate.

  14. Biovar diversity is reflected by variations of genes encoding urease of Ureaplasma urealyticum.

    Science.gov (United States)

    Ruifu, Y; Minli, Z; Guo, Z; Wang, X

    1997-01-01

    Five oligonucleotide primers derived from the gene encoding urease of Ureaplasma urealyticum were designed to evaluate the relationship between the urease gene and biovar diversity of this organism. Five combinations of these primers were tested by PCR and the result revealed that there were variations in urease genes among different serovars of U. urealyticum. This result, in agreement with other PCRs based on other functionally unrelated (rRNA and MB antigen) genes, may reflect the phylogenetic relationship among organisms taxonomically classified as U. urealyticum.

  15. A look into the invisible: ultraviolet-B sensitivity in an insect (Caliothrips phaseoli) revealed through a behavioural action spectrum.

    Science.gov (United States)

    Mazza, Carlos A; Izaguirre, Miriam M; Curiale, Javier; Ballaré, Carlos L

    2010-02-07

    Caliothrips phaseoli, a phytophagous insect, detects and responds to solar ultraviolet-B radiation (UV-B; lambda insects are sensitive. We constructed an action spectrum of thrips responses to light by studying their behavioural reactions to monochromatic irradiation under confinement conditions. Thrips were maximally sensitive to wavelengths between 290 and 330 nm; human-visible wavelengths (lambda >or= 400 nm) failed to elicit any response. All but six ommatidia of the thrips compound eye were highly fluorescent when exposed to UV-A of wavelengths longer than 330 nm. We hypothesized that the fluorescent compound acts as an internal filter, preventing radiation with lambda > 330 nm from reaching the photoreceptor cells. Calculations based on the putative filter transmittance and a visual pigment template of lambda(max) = 360 nm produced a sensitivity spectrum that was strikingly similar to the action spectrum of UV-induced behavioural response. These results suggest that specific UV-B vision in thrips is achieved by a standard UV-A photoreceptor and a sharp cut-off internal filter that blocks longer UV wavelengths in the majority of the ommatidia.

  16. Effects of compost addition and simulated solarisation on the fate of Ralstonia solanacearum biovar 2 and indigenous bacteria in soil

    NARCIS (Netherlands)

    Schonfeld, J.; Gelsomino, A.; Overbeek, van L.S.; Gorissen, A.; Smala, K.; Elsas, van J.D.

    2003-01-01

    The effects of compost addition and simulated solarisation of soil on the survival of Ralstonia solanacearum biovar 2 strain 1609, as well as on the structure of indigenous soil bacterial communities, were analysed. In addition, effects on the invasion of susceptible test plants by strain 1609 were

  17. Comparative genomics of all three Campylobacter sputorum biovars and a novel cattle-associated C. sputorum clade

    Science.gov (United States)

    Campylobacter sputorum is a non-thermotolerant campylobacter that is primarily isolated from food animals such as cattle and sheep. C. sputorum is also infrequently associated with human illness. Based on catalase and urease activity, three biovars are currently recognized within C. sputorum: bv. sp...

  18. [Construction of Frankia genomic libraries and isolation of clones homologous to nodulation genes from Rhizobium leguminosarum].

    Science.gov (United States)

    Cui, Y H; Qin, M; Wang, Y L; Ding, J; Ma, Q S

    1990-01-01

    High molecular genomic DNAs were isolated by using the lysozyme plus achromopeptidase system from Frankia strains At4, Ccol and Hr16, the root nodule endophytes of Alnus, Casuarina and Hippophae respectively, and used to construct genomic libraries in pLAFR1, a broad host range cosmid vector within many gram-negative hosts. The genomic libraries were screened by in situ colony hybridization to identify clones homologous to common nodulation genes of Rhizobium leguminosarum, based on the sequence homology of EcoRI-digested Frankia total DNA to nodABC from Rhizobium meliloti. Several clones showing relatively strong hybridization were found, the recombinant plasmid was isolated, and their homology with Rhizobium nodulation genes was confirmed by spot hybridization. Further work on these positive clones is now underway.

  19. [Improvement of laboratory diagnostics of cholera due to genetically altered (hybrid) variants of cholera Vibrio biovar El Tor].

    Science.gov (United States)

    Savel'eva, I V; Khatsukov, K X; Savel'eva, E I; Moskvitina, S I; Kovalev, D A; Savel'ev, V N; Kulichenko, A N; Antonenko, A D; Babenyshev, B V

    2015-01-01

    Improvement of laboratory diagnostics of cholera taking into the account appearance of hybrid variants of cholera vibrio El Tor biovar in the 1990s. Phenotypic and molecular-genetic properties of typical toxigenic (151 strains) and hybrid (102 strains) variants of El Tor biovar cholera vibrios, isolated in the Caucuses in 1970-1990 and 1993-1998, respectively, were studied. Toxigenicity gene DNA fragments, inherent to El Tor biovars or classic, were detected by using a reagent kit "Genes of Vibrio cholerae variant ctxB-rstR-rstC, REF" developed by us. Reagent kit "Genes of V. cholerae variant ctxB-rstR-rstC, REF" is proposed to be used for laboratory diagnostics of cholera during study of material from humans or environmental objects and for identification of V. cholerae 01 on genome level in PCR-analysis as a necessary addition to the classic scheme of bacteriological analysis. Laboratory diagnostics of cholera due to genetically altered (hybrid) variants of cholera vibrio El Tor biovar is based on a complex study of material from humans and environmental objects by routine bacteriologic and PCR-analysis methods with the aim of detection of gene DNA fragments in the studied material, that determine biovar (classic or El Tor), identification of V. cholerae O1 strains with differentiation of El Tor vibrios into typical and altered, as well as determination of enterotoxin, produced by the specific cholera vibrio strain (by the presence ctxB(El) or ctxB(Cl) gene DNA fragment, coding biosynthesis of CT-2 or CT-1, respectively).

  20. Physiological and serological variation in S. mitis biovar 1 from the human oral cavity during the first year of life

    Science.gov (United States)

    Kirchherr, Jennifer L.; Bowden, George H.; Cole, Michael F.; Kawamura, Yoshiaki; Richmond, Dorothy A.; Sheridan, Michael J.; Wirth, Katherine A.

    2007-01-01

    SUMMARY Objective The purpose of the study was to explore the physiological and antigenic diversity of a large number of S. mitis biovar 1 isolates in order to begin to determine whether these properties contribute to species persistence. Design S. mitis biovar 1 was collected from four infants from birth to one year of age. At each of 8–9 visits 60 isolates each were obtained from the cheeks, tongue and incisors (once erupted) yielding 4,440 in total. These were tested for production of neuraminidase, β1-N-acetylglucosaminidase, β1-N-acetylgalactosaminidase, IgA1 protease, and amylase-binding. Antigenic diversity was examined by ELISA and Western immunoblotting using antisera raised against S. mitis biovar 1 NCTC 12261T and SK145. Results 3,330 (75%) of the isolates were identified as S. mitis biovar 1 and 3,144 (94.4%) could be divided into four large phenotypic groups based on glycosidase production. 54% of the isolates produced IgA1 protease, but production was disproportionate among the phenotypes. Between 1/3 to 1/2 of the strains of each phenotype bound salivary α-amylase. Antisera against strains NCTC 12261T and SK145 displayed different patterns of reactivity with randomly selected representatives of the four phenotypes. Conclusions S. mitis biovar 1 is physiologically and antigenically diverse, properties which could aid strains in avoiding host immunity and promote re-colonization of a habitat or transfer to a new habitat. PMID:17045561

  1. The "missing" typical Rhizobium leguminosarum O antigen is attached to a fatty acylated glycerol in R. leguminosarum bv. trifolii 4S, a strain that also lacks the usual tetrasaccharide "core" component.

    Science.gov (United States)

    Cedergren, R A; Wang, Y; Hollingsworth, R I

    1996-09-01

    Rhizobium leguminosarum bv. trifolii 4S has a lipopolysaccharide O antigen that lacks galactose and many of the typical glycosyl components found in related strains. Here, we show that it also lacks the typical core tetrasaccharide but synthesizes an alternative glycolipid that contains galactose and the typical O-antigen glycosyl components, suggesting that in this strain, the O antigen is transferred to an alternative lipid acceptor.

  2. Post-transcriptional regulation of NifA expression by Hfq and RNase E complex in Rhizobium leguminosarum bv. viciae

    Institute of Scientific and Technical Information of China (English)

    Yinghua Zhang; Guofan Hong

    2009-01-01

    NifA is the general transcriptional activator of nitrogen fixation genes in diazotrophic bacteria. In Rhizobium leguminosarum by. viciae strain 8401/pRL1JI, the NifA gene is part of a gene cluster (fixABCXNifAB). In this study, results showed that in R. leguminosarum by. viciae 8401/pRLI1I, host factor required (Hfq), and RNase E were involved in the post-transcriptional regulation of NifA expression. It was found that Hfq-dependent RNase E cleavage of NifA mRNA was essen-tial for NifA translation. The cleavage site is located at 32 nucleotides upstream of the NifA translational start codon. A possible explanation based on predicted RNA secondary structure of the NifA 5'-untranslated region was that the cleavage made ribosome-binding sites accessible for translation.

  3. Light regulates attachment, exopolysaccharide production, and nodulation in Rhizobium leguminosarum through a LOV-histidine kinase photoreceptor.

    Science.gov (United States)

    Bonomi, Hernán R; Posadas, Diana M; Paris, Gastón; Carrica, Mariela del Carmen; Frederickson, Marcus; Pietrasanta, Lía Isabel; Bogomolni, Roberto A; Zorreguieta, Angeles; Goldbaum, Fernando A

    2012-07-24

    Rhizobium leguminosarum is a soil bacterium that infects root hairs and induces the formation of nitrogen-fixing nodules on leguminous plants. Light, oxygen, and voltage (LOV)-domain proteins are blue-light receptors found in higher plants and many algae, fungi, and bacteria. The genome of R. leguminosarum bv. viciae 3841, a pea-nodulating endosymbiont, encodes a sensor histidine kinase containing a LOV domain at the N-terminal end (R-LOV-HK). R-LOV-HK has a typical LOV domain absorption spectrum with broad bands in the blue and UV-A regions and shows a truncated photocycle. Here we show that the R-LOV-HK protein regulates attachment to an abiotic surface and production of flagellar proteins and exopolysaccharide in response to light. Also, illumination of bacterial cultures before inoculation of pea roots increases the number of nodules per plant and the number of intranodular bacteroids. The effects of light on nodulation are dependent on a functional lov gene. The results presented in this work suggest that light, sensed by R-LOV-HK, is an important environmental factor that controls adaptive responses and the symbiotic efficiency of R. leguminosarum.

  4. Rhizobium leguminosarum is the symbiont of lentils in the Middle East and Europe but not in Bangladesh.

    Science.gov (United States)

    Harun-or Rashid, M; Gonzalez, Javier; Young, J Peter W; Wink, Michael

    2014-01-01

    Lentil is the oldest of the crops that have been domesticated in the Fertile Crescent and spread to other regions during the Bronze Age, making it an ideal model to study the evolution of rhizobia associated with crop legumes. Housekeeping and nodulation genes of lentil-nodulating rhizobia from the region where lentil originated (Turkey and Syria) and regions to which lentil was introduced later (Germany and Bangladesh) were analyzed to determine their genetic diversity, population structure, and taxonomic position. There are four different lineages of rhizobia associated with lentil nodulation, of which three are new and endemic to Bangladesh, while Mediterranean and Central European lentil symbionts belong to the Rhizobium leguminosarum lineage. The endemic lentil grex pilosae may have played a significant role in the origin of these new lineages in Bangladesh. The presence of R. leguminosarum with lentil at the center of origin and in countries where lentil was introduced later suggests that R. leguminosarum is the original symbiont of lentil. Lentil seeds may have played a significant role in the initial dispersal of this Rhizobium species within the Middle East and on to other countries. Nodulation gene sequences revealed a high similarity to those of symbiovar viciae.

  5. The draft genome sequence of Corynebacterium diphtheriae bv. mitis NCTC 3529 reveals significant diversity between the primary disease-causing biovars.

    Science.gov (United States)

    Sangal, Vartul; Tucker, Nicholas P; Burkovski, Andreas; Hoskisson, Paul A

    2012-06-01

    We report the draft genome of the human pathogen Corynebacterium diphtheriae bv. mitis NCTC 3529. This is the first C. diphtheriae bv. mitis strain to be sequenced and reveals significant differences from the other primary biovar, C. diphtheriae bv. gravis.

  6. The Draft Genome Sequence of Corynebacterium diphtheriae bv. mitis NCTC 3529 Reveals Significant Diversity between the Primary Disease-Causing Biovars

    OpenAIRE

    Sangal, Vartul; Nicholas P Tucker; Burkovski, Andreas; Hoskisson, Paul A.

    2012-01-01

    We report the draft genome of the human pathogen Corynebacterium diphtheriae bv. mitis NCTC 3529. This is the first C. diphtheriae bv. mitis strain to be sequenced and reveals significant differences from the other primary biovar, C. diphtheriae bv. gravis.

  7. First report of orchitis in man caused by Brucella abortus biovar 1 in Ecuador.

    Science.gov (United States)

    Ron-Román, Jorge; Saegerman, Claude; Minda-Aluisa, Elizabeth; Benítez-Ortíz, Washington; Brandt, Jef; Douce, Richard

    2012-09-01

    We present a 44-year-old man from a rural community in northern Ecuador who worked on a cattle farm where he was involved with primary veterinary care, including assistance during births (or calving) and placenta retention and artificial insemination, with minimal precautions. In September of 2009, quite abruptly, he developed asthenia and hypersomnia without any apparent cause or symptoms like fever, chills, or night sweats. On November 14, 2009, he suffered from pain and edema in the right testicle that coincided with pain in the abdomen. Clinical, serological, and bacteriological investigations confirmed the first case of unilateral orchitis in man in Ecuador caused by Brucella abortus biovar 1. Because brucellosis is a neglected disease, special attention should be given to it in the training of medical and veterinary students.

  8. Effect of bean genotypes, insecticides, and natural products on the control of Bemisia tabaci (Gennadius biotype B (Hemiptera: Aleyrodidae and Caliothrips phaseoli (Hood (Thysanoptera: Thripidae = Efeito de genótipos de feijoeiro, inseticida e produtos naturais no controle Bemisia tabaci (Gennadius biotipo B (Hemiptera: Aleyrodidae e Caliothrips phaseoli (Hood (Thysanoptera: Thripidae

    Directory of Open Access Journals (Sweden)

    Júlio Cesar Janini

    2011-07-01

    Full Text Available Effect of bean genotypes, insecticides, and natural products on the control of Bemisia tabaci (Gennadius biotype B (Hemiptera: Aleyrodidae and Caliothrips phaseoli (Hood (Thysanoptera: Thripidae. The influence of bean genotypes associated with neem oil as insecticide was evaluated to control B. tabaci (Gennadius biotype B and C. phaseoli (Hood during the wet season sowing. The experimental design used was the randomized block arrangement in a 4x4x3 factorial scheme, represented by genotypes, neem oil and insecticides respectively, with three replications. The genotypes Carioca, IAC Harmonia, IAC Centauro and Pérola were used. The evaluations were done at 14 and 42 days after seedling emergence, bycounting B. tabaci biotype B eggs and nymphs and C. phaseoli nymphs in the genotypes leaf. Conclusion: The B. tabaci biotype B eggs and nymphs number were smaller in IAC Centauro and higher in IAC Harmonia. The tested genotypes were similarly infested by C. phaseoli. IAC Centauro and IAC Harmonia genotypes associated with neem oil (highlighting the full dose – 1% provided lower number of whitefly eggs and thrips nymphs. Neem oil at the full dose alsoreduced whitefly nymph number. In the tested genotypes the insecticide provided reduction in the number of whitefly eggs and nymphs as well in the thrips nymphs, with increase in therecommend dose. Avaliou-se a influência de genótipos de feijoeiro associado à aplicação de óleo de nim e inseticida no controle de B. tabaci (Gennadius biótipo B e C. phaseoli (Hood na época de semeadura “das águas”. O delineamento experimental utilizados foi o de blocos casualizados dispostos em um esquema fatorial 4 x 3 x 3, representado por variedades, óleo de nim e inseticidas, respectivamente, com três repetições. Utilizaram-se os genótipos Carioca, IAC Harmonia, IAC Centauro e Pérola. As avaliações foram realizadas dos 14 aos 42 dias após a emergência das plantas, contando-se o número de ovos e

  9. Typing discrepancy between phenotypic and molecular characterization revealing an emerging biovar 9 variant of smooth phage-resistant B. abortus strain 8416 in China

    Directory of Open Access Journals (Sweden)

    YaoXia eKang

    2015-12-01

    Full Text Available A newly isolated smooth colony morphology phage-resistant (SPR strain 8416 isolated from a 45-year-old cattle farm cleaner with clinical features of brucellosis in China was reported. The most unusual phenotype was its resistance to two Brucella phages Tbilisi and Weybridge, but sensitive to Berkeley 2, a pattern similar to that of B. melitensis biovar 1. VITEK 2 biochemical identification system found that both strain 8416 and B. melitensis strains shared positive ILATk, but negative in other B. abortus strains. However, routine biochemical and phenotypic characteristics of strain 8416 were most similar to that of B. abortus biovar 9 except CO2 requirement. In addition, multiple PCR molecular typing assays including AMOS-PCR, B. abortus special PCR (B-ab PCR and a novel sub-biovar typing PCR, indicated that strain 8416 may belong to either biovar 3b or 9 of B. abortus. Surprisingly, further MLVA typing results showed that strain 8416 was most closely related to B. abortus biovar 3 in the Brucella MLVA database, primarily differing in 4 out of 16 screened loci. Therefore, due to the unusual discrepancy between phenotypic (biochemical reactions and particular phage lysis profile and molecular typing characteristics, strain 8416 couldn’t be exactly classified to any of the existing B. abortus biovars and might be a new variant of B. abortus biovar 9. The present study also indicates that the present phage typing scheme for Brucella spp. is subject to variation and the routine Brucella biovar typing needs further studies.

  10. Phenotypic and genotypic characterization of Brucella strains isolated from autochthonous livestock reveals the dominance of B. abortus biovar 3a in Nigeria.

    Science.gov (United States)

    Bertu, Wilson J; Ducrotoy, Marie J; Muñoz, Pilar M; Mick, Virginie; Zúñiga-Ripa, Amaia; Bryssinckx, Ward; Kwaga, Jacob K P; Kabir, Junaid; Welburn, Susan C; Moriyón, Ignacio; Ocholi, Reuben A

    2015-10-22

    Brucellosis is a worldwide widespread zoonosis caused by bacteria of the genus Brucella. Control of this disease in a given area requires an understanding of the Brucella species circulating in livestock and humans. However, because of the difficulties intrinsic to Brucella isolation and typing, such data are scarce for resource-poor areas. The paucity of bacteriological data and the consequent imperfect epidemiological picture are particularly critical for Sahelian and Sub-Sahara African countries. Here, we report on the characterization of 34 isolates collected between 1976 and 2012 from cattle, sheep and horses in Nigeria. All isolates were identified as Brucella abortus by Bruce-ladder PCR and assigned to biovar 3 by conventional typing. Further analysis by enhanced AMOS-ERY PCR showed that all of them belonged to the 3a sub-biovar, and MLVA analysis grouped them in a cluster clearly distinct from that formed by European B. abortus biovar 3b strains. Nevertheless, MLVA detected heterogeneity within the Nigerian biovar 3a strains. The close genetic profiles of the isolates from cattle, sheep and horses, suggest that, at least in some parts of Nigeria, biovar 3a circulates among animal species that are not the preferential hosts of B. abortus. Consistent with previous genetic analyses of 7 strains from Ivory Cost, Gambia and Togo, the analysis of these 34 Nigerian strains supports the hypothesis that the B. abortus biovar 3a lineage is dominant in West African countries.

  11. The Regulatory Protein RosR Affects Rhizobium leguminosarum bv. trifolii Protein Profiles, Cell Surface Properties, and Symbiosis with Clover

    Science.gov (United States)

    Rachwał, Kamila; Boguszewska, Aleksandra; Kopcińska, Joanna; Karaś, Magdalena; Tchórzewski, Marek; Janczarek, Monika

    2016-01-01

    Rhizobium leguminosarum bv. trifolii is capable of establishing a symbiotic relationship with plants from the genus Trifolium. Previously, a regulatory protein encoded by rosR was identified and characterized in this bacterium. RosR possesses a Cys2-His2-type zinc finger motif and belongs to Ros/MucR family of rhizobial transcriptional regulators. Transcriptome profiling of the rosR mutant revealed a role of this protein in several cellular processes, including the synthesis of cell-surface components and polysaccharides, motility, and bacterial metabolism. Here, we show that a mutation in rosR resulted in considerable changes in R. leguminosarum bv. trifolii protein profiles. Extracellular, membrane, and periplasmic protein profiles of R. leguminosarum bv. trifolii wild type and the rosR mutant were examined, and proteins with substantially different abundances between these strains were identified. Compared with the wild type, extracellular fraction of the rosR mutant contained greater amounts of several proteins, including Ca2+-binding cadherin-like proteins, a RTX-like protein, autoaggregation protein RapA1, and flagellins FlaA and FlaB. In contrast, several proteins involved in the uptake of various substrates were less abundant in the mutant strain (DppA, BraC, and SfuA). In addition, differences were observed in membrane proteins of the mutant and wild-type strains, which mainly concerned various transport system components. Using atomic force microscopy (AFM) imaging, we characterized the topography and surface properties of the rosR mutant and wild-type cells. We found that the mutation in rosR gene also affected surface properties of R. leguminosarum bv. trifolii. The mutant cells were significantly more hydrophobic than the wild-type cells, and their outer membrane was three times more permeable to the hydrophobic dye N-phenyl-1-naphthylamine. The mutation of rosR also caused defects in bacterial symbiotic interaction with clover plants. Compared with

  12. Rhizobium leguminosarum COMO ORGANISMO BIOCONTROLADOR DE LA INTERACCIÓN HOSPEDERO-PATÓGENO: CLAVEL (Dianthus caryophyllus – Fusarium Oxysporum f. sp. dianthi

    Directory of Open Access Journals (Sweden)

    Cheol Woo Lee Park

    2010-08-01

    Full Text Available Se investigó el efecto de biocontrol de Rhizobium leguminosarum (R. leguminosarum cepa B, contra Fusarium oxysporum f.sp.dianthi (FOD raza 2, en la interacción Clavel - FOD. Se utilizó la raza 2 de FOD por ser la de mayor patogenicidad y distribución en las fincas de cultivo de clavel en Colombia. Para ello se establecieron las condiciones de inoculación de FOD sobre cultivos establecidos de R . leguminosarum, variando la concentración in vitro de la bacteria. Se encontró una reducción en el número de microconidias hasta un 90% y una inhibición en el crecimiento radial del patógeno de hasta un 71 %. En el ensayo de microcultivo dual se detectó fraccionamiento de las hifas después de 48 horas de incubación con R . leguminosarum En el ensayo in vivo, los esquejes de clavel Raggio di solé, variedad susceptible al patógeno, fueron inoculados con 45.0 x 10 células de R. leguminosarum por matero, mostrando una severidad inferior al 5%, una incidencia menor del 20% y una reducción del índice de la enfermedad hasta de un 92% en presencia del patógeno.

  13. Colonização radicular de plantas cultivadas por Ralstonia solanacearum biovares 1, 2 e 3 Root colonization of cultivated plants inoculated with Ralstonia solanacearum biovar 1, 2 and 3

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    José Magno Martins Bringel

    2001-09-01

    Full Text Available A murcha bacteriana causada por Ralstonia solanacearum é considerada a principal doença de origem bacteriana no mundo. Centenas de espécies de plantas pertencentes a mais de 50 famílias botânicas têm sido relatadas como hospedeiras. Foi avaliada, em condições de casa de vegetação, a colonização radicular de alface, arroz, cebolinha, ervilha, pepino e soja, por seis isolados de Ralstonia solanacearum (Rs, biovares 1, 2 e 3. Estirpes dos isolados de Rs com resistência múltipla aos antibióticos estreptomicina, rifampicina e cloranfenicol foram utilizadas. A colonização foi avaliada 45 dias após a inoculação, através do plaqueamento de suspensão de trituração em meio de cultura semi-seletivo. A ervilha comportou-se como hospedeira de todos os isolados mas, apenas um isolado da biovar 3 foi patogênico a esta espécie. A soja apresentou populações elevadas de quatro isolados distribuídos entre as três biovares e o pepino, de apenas dois isolados das biovares 1 e 3. Exceto para o isolado que foi patogênico à ervilha, as plantas não apresentaram sintomas da doença, comportando-se como hospedeiras não suscetível. O arroz apresentou populações muito baixas de todos os isolados. Alface e cebolinha não hospedaram nenhum dos isolados inoculados. Os resultados mostram a capacidade de Rs colonizar e sobreviver em diferentes espécies de plantas como rizobactérias.Bacterial wilt caused by Ralstonia solanacearum is considered the main plant disease of bacterial origin in the world, where hundreds of plant species in more than 50 botanical families are host plants. Root colonization of lettuce (Lactuca sativa, rice (Oryza sativa, spring onion (Allium fistulosum, pea (Pisum sativum, cucumber (Cucumis sativus, and soybean (Glycine max by six isolates of Ralstonia solanacearum (Rs biovars 1, 2 and 3 was evaluated under greenhouse conditions. Bacterial strains resistant to streptomycin, rifampicin and chloranfenicol were used

  14. Transcriptomic Analysis of Yersinia enterocolitica Biovar 1B Infecting Murine Macrophages Reveals New Mechanisms of Extracellular and Intracellular Survival

    OpenAIRE

    2015-01-01

    Yersinia enterocolitica is typically considered an extracellular pathogen; however, during the course of an infection, a significant number of bacteria are stably maintained within host cell vacuoles. Little is known about this population and the role it plays during an infection. To address this question and to elucidate the spatially and temporally dynamic gene expression patterns of Y. enterocolitica biovar 1B through the course of an in vitro infection, transcriptome sequencing and differ...

  15. Bacterial wilt of potato (Ralstonia solanacearum race 3, biovar 2): disease management, pathogen survival and possible eradication

    NARCIS (Netherlands)

    Messiha, N.A.S.

    2006-01-01

    Potato brown rot, caused by Ralstonia solanacearum race 3 biovar 2 (Phylovar II, sequevar 1), is a serious endemic disease in the Nile Delta of Egypt. It is a quarantine disease in the EU, and export of potatoes fromEgypt

  16. Regulation of nitrogen metabolism is altered in a glnB mutant strain of Rhizobium leguminosarum.

    Science.gov (United States)

    Amar, M; Patriarca, E J; Manco, G; Bernard, P; Riccio, A; Lamberti, A; Defez, R; Iaccarino, M

    1994-02-01

    We isolated a Rhizobium leguminosarum mutant strain altered in the glnB gene. This event, which has never been described in the Rhizobiaceae, is rare in comparison to mutants isolated in the contiguous gene, glnA. The glnB mutation removes the glnBA promoter but in vivo does not prevent glnA expression from its own promoter, which is not nitrogen regulated. The glnB mutant strain does not grow on nitrate as a sole nitrogen source and it is Nod+, Fix+. Two -24/-12 promoters, for the glnII and glnBA genes, are constitutively expressed in the glnB mutant, while two -35/-10-like promoters for glnA and ntrBC are unaffected. We propose that the glnB gene product, the PII protein, plays a negative role in the ability of NtrC to activate transcription from its target promoters and a positive role in the mechanism of nitrate utilization.

  17. SYMBIOTIC EFFECTIVENESS OF RHIZOBIUM LEGUMINOSARUM BV. VICIAE WITH PEA PLANTS AS INFLUENCED BY AZOTOBACTER CHROOCOCCUM

    Directory of Open Access Journals (Sweden)

    Stefan Martyniuk

    2015-09-01

    Full Text Available The aim of this work was to examine the effects of A. chroococcum on the proliferation of R. leguminosarum bv. viciae (Rlv in a solid-carrier inoculant and on symbiotic effectiveness of Rlv with pea plants grown under laboratory and field conditions. In a laboratory experiment it was found that proliferation of both bacterial species, Rlv and A. chroococcum, in the dual-culture inoculants was efficient, and that A. chroococcum had no adverse effects on the development of the rhizobia (Rlv in the solid-carrier inoculant. In a pot experiment the highest number of nodules was detected on roots of pea plants inoculated with the dual-culture inoculant containing Rlv and A. chroococcum, slightly lower numbers on pea roots inoculated with the mono-culture inoculum of Rlv and almost no nodules were found on the roots of pea un-inoculated (control treatment with the bacteria. In the micro-plot experiment conducted in the years 2011–2012 pre-sowing inoculation of pea seeds with the mono-culture inoculant of Rlv or with the mixed inoculant of Rlv and A. chroococcum slightly increased nodule numbers/plant, pod numbers/plant and seed numbers/pod, as compared to the un-inoculated control, but these differences were not reflected in pea seed yields/m2, which were similar in all treatments.

  18. Modulation of rosR expression and exopolysaccharide production in Rhizobium leguminosarum bv. trifolii by phosphate and clover root exudates.

    Science.gov (United States)

    Janczarek, Monika; Skorupska, Anna

    2011-01-01

    The acidic exopolysaccharide (EPS) secreted in large amounts by the symbiotic nitrogen-fixing bacterium Rhizobium leguminosarum bv. trifolii is required for the establishment of an effective symbiosis with the host plant Trifolium spp. EPS biosynthesis in rhizobia is a very complex process regulated at both transcriptional and post-transcriptional levels and influenced by various nutritional and environmental conditions. The R. leguminosarum bv. trifolii rosR gene encodes a transcriptional regulator with a C(2)H(2) type zinc-finger motif involved in positive regulation of EPS synthesis. In silico sequence analysis of the 450-bp long rosR upstream region revealed the presence of several inverted repeats (IR1 to IR6) and motifs with significant identity to consensus sequences recognized by PhoB and LysR-type proteins associated with phosphate- and flavonoid-dependent gene regulation in R. leguminosarum. Using a set of sequentially truncated rosR-lacZ transcriptional fusions, the role of the individual motifs and the effect of phosphate and clover root exudates on rosR expression were established. In addition, the significance of IR4 inverted repeats in the repression, and P2-10 hexamer in the activation of rosR transcription, respectively, was found. The expression of rosR increased in the presence of phosphate (0.1-20 mM) and clover root exudates (10 μM). PHO boxes and the LysR motif located upstream of the rosR translation start site were engaged in the regulation of rosR transcription. The synthesis of EPS and biofilm formation decreased at high phosphate concentrations, but increased in the presence of clover root exudates, indicating a complex regulation of these processes.

  19. Rhizobium leguminosarum bv. trifolii rosR is required for interaction with clover, biofilm formation and adaptation to the environment

    Science.gov (United States)

    2010-01-01

    Background Rhizobium leguminosarum bv. trifolii is a symbiotic nitrogen-fixing bacterium that elicits nodules on roots of host plants Trifolium spp. Bacterial surface polysaccharides are crucial for establishment of a successful symbiosis with legumes that form indeterminate-type nodules, such as Trifolium, Pisum, Vicia, and Medicago spp. and aid the bacterium in withstanding osmotic and other environmental stresses. Recently, the R. leguminosarum bv. trifolii RosR regulatory protein which controls exopolysaccharide production has been identified and characterized. Results In this work, we extend our earlier studies to the characterization of rosR mutants which exhibit pleiotropic phenotypes. The mutants produce three times less exopolysaccharide than the wild type, and the low-molecular-weight fraction in that polymer is greatly reduced. Mutation in rosR also results in quantitative alterations in the polysaccharide constituent of lipopolysaccharide. The rosR mutants are more sensitive to surface-active detergents, antibiotics of the beta-lactam group and some osmolytes, indicating changes in the bacterial membranes. In addition, the rosR mutants exhibit significant decrease in motility and form a biofilm on plastic surfaces, which differs significantly in depth, architecture, and bacterial viability from that of the wild type. The most striking effect of rosR mutation is the considerably decreased attachment and colonization of root hairs, indicating that the mutation affects the first stage of the invasion process. Infection threads initiate at a drastically reduced rate and frequently abort before they reach the base of root hairs. Although these mutants form nodules on clover, they are unable to fix nitrogen and are outcompeted by the wild type in mixed inoculations, demonstrating that functional rosR is important for competitive nodulation. Conclusions This report demonstrates the significant role RosR regulatory protein plays in bacterial stress adaptation

  20. Rhizobium leguminosarum bv. trifolii rosR is required for interaction with clover, biofilm formation and adaptation to the environment

    Directory of Open Access Journals (Sweden)

    Piersiak Tomasz

    2010-11-01

    Full Text Available Abstract Background Rhizobium leguminosarum bv. trifolii is a symbiotic nitrogen-fixing bacterium that elicits nodules on roots of host plants Trifolium spp. Bacterial surface polysaccharides are crucial for establishment of a successful symbiosis with legumes that form indeterminate-type nodules, such as Trifolium, Pisum, Vicia, and Medicago spp. and aid the bacterium in withstanding osmotic and other environmental stresses. Recently, the R. leguminosarum bv. trifolii RosR regulatory protein which controls exopolysaccharide production has been identified and characterized. Results In this work, we extend our earlier studies to the characterization of rosR mutants which exhibit pleiotropic phenotypes. The mutants produce three times less exopolysaccharide than the wild type, and the low-molecular-weight fraction in that polymer is greatly reduced. Mutation in rosR also results in quantitative alterations in the polysaccharide constituent of lipopolysaccharide. The rosR mutants are more sensitive to surface-active detergents, antibiotics of the beta-lactam group and some osmolytes, indicating changes in the bacterial membranes. In addition, the rosR mutants exhibit significant decrease in motility and form a biofilm on plastic surfaces, which differs significantly in depth, architecture, and bacterial viability from that of the wild type. The most striking effect of rosR mutation is the considerably decreased attachment and colonization of root hairs, indicating that the mutation affects the first stage of the invasion process. Infection threads initiate at a drastically reduced rate and frequently abort before they reach the base of root hairs. Although these mutants form nodules on clover, they are unable to fix nitrogen and are outcompeted by the wild type in mixed inoculations, demonstrating that functional rosR is important for competitive nodulation. Conclusions This report demonstrates the significant role RosR regulatory protein plays in

  1. Deduced products of C4-dicarboxylate transport regulatory genes of Rhizobium leguminosarum are homologous to nitrogen regulatory gene products.

    OpenAIRE

    Ronson, C W; Astwood, P M; Nixon, B T; Ausubel, F M

    1987-01-01

    We have sequenced two genes dctB and dctD required for the activation of the C4-dicarboxylate transport structural gene dctA in free-living Rhizobium leguminosarum. The hydropathic profile of the dctB gene product (DctB) suggested that its N-terminal region may be located in the periplasm and its C-terminal region in the cytoplasm. The C-terminal region of DctB was strongly conserved with similar regions of the products of several regulatory genes that may act as environmental sensors, includ...

  2. Deduced products of C4-dicarboxylate transport regulatory genes of Rhizobium leguminosarum are homologous to nitrogen regulatory gene products.

    OpenAIRE

    Ronson, C W; Astwood, P M; Nixon, B T; Ausubel, F M

    1987-01-01

    We have sequenced two genes dctB and dctD required for the activation of the C4-dicarboxylate transport structural gene dctA in free-living Rhizobium leguminosarum. The hydropathic profile of the dctB gene product (DctB) suggested that its N-terminal region may be located in the periplasm and its C-terminal region in the cytoplasm. The C-terminal region of DctB was strongly conserved with similar regions of the products of several regulatory genes that may act as environmental sensors, includ...

  3. Seroprevalence of brucellosis and typing of Brucella melitensis biovar 2 in lactating cows in Kuwait

    Directory of Open Access Journals (Sweden)

    Adel El-Gohary

    2016-09-01

    Results: The results showed that the overall seroprevalence of bovine brucellosis was 339 (7.25% by BAPAT, 332 (7.1% by RBPT, and 329 (7.04% by CFT. The results revealed that, 42 (8.6%, 5 (1.4% and 292 (7.6% sera were positive for brucellosis by BAPAT in the cows of Al-Wafra, Al-Kabed and Al-Salebia areas, respectively. Whereas, their respective number and seroreactive cases by RBPT were 39 (8.02%, 5 (1.4% and 288 (7.4%. Similarly, as confirmatory test by CFT, the number and seroreactive cases in these areas were 39 (8.02%, 5 (1.4% and 285 (7.46%. MRT revealed that the average positive case was 61.67% (59.46% in Al-Wafra; 60% in Al-Kabed and 66.6% in Al-Salebia. Two Brucella isolates could be recovered from the stomach content of the two aborted feti and typed as Brucella melitensis biovar 2. Conclusion: Brucellosis is prevalent among lactating cows in Kuwait. This indicates the potential role of these dairy animals in disseminating and spread of such zoonosis to human. Considering public health significance, appropriate preventive measures are suggestive for combating brucellosis in Kuwait. [J Adv Vet Anim Res 2016; 3(3.000: 229-235

  4. Asymptomatic Brucella bacteraemia and isolation of Brucella melitensis biovar 3 from human breast milk.

    Science.gov (United States)

    Celebi, Güven; Külah, Canan; Kiliç, Selçuk; Ustündağ, Gonca

    2007-01-01

    Brucellosis is a zoonotic disease and virtually all infections derived from exposure to animals or ingestion of unpasteurized dairy products. Brucellosis among family members has been reported. However, screening household members of an index case of acute brucellosis is not a routine procedure. A 10-y-old boy was diagnosed with acute brucellosis. Unpasteurized goat cheese commonly consumed within the family was thought to be the possible source of the bacteria. The family (parents, sister and brother) was screened with physical examination, serum tube agglutination test, blood cultures and routine laboratory tests. Three additional cases (parents and sister) of serological and culture proven brucellosis were detected. Two of them (mother and sister) were asymptomatic and had no clinical findings. Brucella melitensis biovar 3 was isolated from breast milk culture and from all blood cultures of 4 brucellosis cases. In conclusion, brucellosis, even with bacteraemia, can be completely asymptomatic. Consumption of raw milk products by household members is a common risk factor for brucellosis outbreak among family members. Thus, screening household members of an index case of brucellosis can expose new brucellosis cases.

  5. Occurrence of Xanthomonas axonopodis pv. phaseoli, the causal agent of common bacterial blight disease, on seeds of common bean (Phaseolus vulgaris L.) in upper Egypt.

    Science.gov (United States)

    Abd-Alla, M H; Bashandy, S R; Schnell, S

    2010-01-01

    Common bean seed lots collected from different seed dealers and Malawii agriculture station were screened for the presence of Xanthomonas axonopodis pv. phaseoli. In the laboratory the pathogen was isolated following the routine laboratory assay method, i.e. direct plating method using yeast extract-dextrose-calcium carbonate agar medium (YDC). Yellow, convex, mucoid colonies of Xanthomonas were consistently isolated on YDC from seed samples. The presumptive pathogen was confirmed by isolation on semiselective medium, such as mTBM and MD5A. Further, the pathogen was confirmed by biochemical, physiological and, finally, the pathogenicity tests. Five samples out of seven were positive for Xanthomonas. The isolates were found to cause common blight of 3-week-old common bean plants by 7 d after inoculation. Bacteria with the same characteristics as those inoculated were re-isolated from the infected plants.

  6. Eumycetoma caused by Diaporthe phaseolorum (Phomopsis phaseoli): a case report and a mini-review of Diaporthe/Phomopsis spp invasive infections in humans.

    Science.gov (United States)

    Iriart, X; Binois, R; Fior, A; Blanchet, D; Berry, A; Cassaing, S; Amazan, E; Papot, E; Carme, B; Aznar, C; Couppié, P

    2011-10-01

    Diaporthe phaseolorum (syn. Phomopsis phaseoli) is a frequent fungal parasite of plants, present on all continents around the world. It has rarely been involved in human diseases. We report a case of eumycetoma with osteomyelitis of the forefoot caused by this fungus and diagnosed by molecular biology. The patient had positive HTLV-1 serology and was a farmer from French Guiana who walked barefoot. He was successfully treated with long-term oral itraconazole (400 mg/day). A review of the literature underlines the essential roles of plants and host immunosuppression in this infection and the favourable outcome with a triazole antifungal treatment. © 2011 The Authors. Clinical Microbiology and Infection © 2011 European Society of Clinical Microbiology and Infectious Diseases.

  7. Analysis of iron acquisition and storage-related genes in clinical and non-clinical strains of Yersinia enterocolitica biovar 1A.

    Science.gov (United States)

    Kanaujia, Pawan Kumar; Bajaj, Priyanka; Virdi, Jugsharan Singh

    2015-10-01

    Possession of mechanisms for iron acquisition and its storage enhances the ability of the bacteria to survive in the iron-limiting environment of the host. In this study, 81 strains of Yersinia enterocolitica biovar 1A isolated from various clinical (n = 51) and non-clinical (n = 30) sources were investigated for the presence of the genes related to iron acquisition and storage. Important genes which were present in more than 85% of the strains included hasA, foxA, bfr, bfd, ftnA, and hmsT as well as the fhuCDB, fepBDGCfesfepA, feoAB, yfuABCD, hemPRSTUV, and hmsHFRS gene clusters. Majority of these genes is being reported for the first time in biovar 1A strains and showed significant homology with genes present in the known pathogenic biovars of Y. enterocolitica. However, no significant difference was observed in the distribution of iron acquisition and storage-related genes among clinical and non-clinical biovar 1A strains. Thus, it may be suggested that the presence of iron acquisition and storage-related genes per se might not be responsible for the supposedly better ability of clinical biovar 1A strains to cause infections in humans. However, in the backdrop of this data, the need to undertake functional studies are highly recommended.

  8. Identification of protein secretion systems and novel secreted proteins in Rhizobium leguminosarum bv. viciae

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    Krehenbrink Martin

    2008-01-01

    Full Text Available Abstract Background Proteins secreted by bacteria play an important role in infection of eukaryotic hosts. Rhizobia infect the roots of leguminous plants and establish a mutually beneficial symbiosis. Proteins secreted during the infection process by some rhizobial strains can influence infection and modify the plant defence signalling pathways. The aim of this study was to systematically analyse protein secretion in the recently sequenced strain Rhizobium leguminosarum bv. viciae 3841. Results Similarity searches using defined protein secretion systems from other Gram-negative bacteria as query sequences revealed that R. l. bv. viciae 3841 has ten putative protein secretion systems. These are the general export pathway (GEP, a twin-arginine translocase (TAT secretion system, four separate Type I systems, one putative Type IV system and three Type V autotransporters. Mutations in genes encoding each of these (except the GEP were generated, but only mutations affecting the PrsDE (Type I and TAT systems were observed to affect the growth phenotype and the profile of proteins in the culture supernatant. Bioinformatic analysis and mass fingerprinting of tryptic fragments of culture supernatant proteins identified 14 putative Type I substrates, 12 of which are secreted via the PrsDE, secretion system. The TAT mutant was defective for the symbiosis, forming nodules incapable of nitrogen fixation. Conclusion None of the R. l. bv. viciae 3841 protein secretion systems putatively involved in the secretion of proteins to the extracellular space (Type I, Type IV, Type V is required for establishing the symbiosis with legumes. The PrsDE (Type I system was shown to be the major route of protein secretion in non-symbiotic cells and to secrete proteins of widely varied size and predicted function. This is in contrast to many Type I systems from other bacteria, which typically secrete specific substrates encoded by genes often localised in close proximity to

  9. Competitive nodulation blocking of cv. Afghanistan pea is related to high levels of nodulation factors made by some strains of Rhizobium leguminosarum bv. viciae

    NARCIS (Netherlands)

    Hogg, B.; Davies, A.E.; Wilson, K.E.; Bisseling, T.; Downie, J.A.

    2002-01-01

    Cultivar Afghanistan peas are resistant to nodulation by many strains of Rhizobium leguminosarum bv. viciae but are nodulated by strain TOM, which carries the host specificity gene nodX. Some strains that lack nodX can inhibit nodulation of cv. Afghanistan by strain TOM. We present evidence that

  10. Comparative Transcriptome Analysis Reveals Cool Virulence Factors of Ralstonia solanacearum Race 3 Biovar 2.

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    Fanhong Meng

    Full Text Available While most strains of the plant pathogenic bacterium Ralstonia solanacearum are tropical, the race 3 biovar 2 (R3bv2 subgroup attacks plants in cooler climates. To identify mechanisms underlying this trait, we compared the transcriptional profiles of R. solanacearum R3bv2 strain UW551 and tropical strain GMI1000 at 20°C and 28°C, both in culture and during tomato pathogenesis. 4.2% of the ORFs in the UW551 genome and 7.9% of the GMI1000 ORFs were differentially expressed by temperature in planta. The two strains had distinct transcriptional responses to temperature change. GMI1000 up-regulated several stress response genes at 20°C, apparently struggling to cope with plant defenses. At the cooler temperature, R3bv2 strain UW551 up-regulated a cluster encoding a mannose-fucose binding lectin, LecM; a quorum sensing-dependent protein, AidA; and a related hypothetical protein, AidC. The last two genes are absent from the GMI1000 genome. In UW551, all three genes were positively regulated by the adjacent SolI/R quorum sensing system. These temperature-responsive genes were required for full virulence in R3bv2. Mutants lacking lecM, aidA, or aidC were each significantly more reduced in virulence on tomato at 20°C than at 28°C in both a naturalistic soil soak inoculation assay and when they were inoculated directly into tomato stems. The lecM and aidC mutants also survived poorly in potato tubers at the seed tuber storage temperature of 4°C, and the lecM mutant was defective in biofilm formation in vitro. Together, these results suggest novel mechanisms, including a lectin, are involved in the unique temperate epidemiology of R3bv2.

  11. Exploring the Diversity of Field Strains of Brucella abortus Biovar 3 Isolated in West Africa

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    Moussa Sanogo

    2017-06-01

    Full Text Available Brucellosis is one of the most widespread bacterial zoonotic diseases in the world, affecting both humans and domestic and wild animals. Identification and biotyping of field strains of Brucella are of key importance for a better knowledge of the epidemiology of brucellosis, for identifying appropriate antigens, for managing disease outbreaks and for setting up efficient preventive and control programmes. Such data are required both at national and regional level to assess potential threats for public health. Highly discriminative genotyping methods such as the multiple locus variable number of tandem repeats analysis (MLVA allow the comparison and assessment of genetic relatedness between field strains of Brucella within the same geographical area. In this study, MLVA biotyping data retrieved from the literature using a systematic review were compared using a clustering analysis and the Hunter-Gaston diversity index (HGDI. Thus, the analysis of the 42 MLVA genotyping results found in the literature on West Africa [i.e., from Ivory Coast (1, Niger (1, Nigeria (34, The Gambia (3, and Togo (3] did not allow a complete assessment of the actual diversity among field strains of Brucella. However, it provided some preliminary indications on the co-existence of 25 distinct genotypes of Brucella abortus biovar 3 in this region with 19 genotypes from Nigeria, three from Togo and one from Ivory Coast, The Gambia, and Niger. The strong and urgent need for more sustainable molecular data on prevailing strains of Brucella in this sub-region of Africa and also on all susceptible species including humans is therefore highlighted. This remains a necessary stage to allow a comprehensive understanding of the relatedness between field strains of Brucella and the epidemiology of brucellosis within West Africa countries.

  12. Genetic relatedness of Brucella suis biovar 2 isolates from hares, wild boars and domestic pigs.

    Science.gov (United States)

    Kreizinger, Zsuzsa; Foster, Jeffrey T; Rónai, Zsuzsanna; Sulyok, Kinga M; Wehmann, Enikő; Jánosi, Szilárd; Gyuranecz, Miklós

    2014-08-27

    Porcine brucellosis generally manifests as disorders in reproductive organs potentially leading to serious losses in the swine industry. Brucella suis biovar 2 is endemic in European wild boar (Sus scrofa) and hare (Lepus europeus, Lepus capensis) populations, thus these species may play a significant role in disease spread and serve as potential sources of infection for domestic pigs. The aim of this study was an epidemiologic analysis of porcine brucellosis in Hungary and a comparative analysis of B. suis bv. 2 strains from Europe using multiple-locus variable-number tandem repeat analysis (MLVA). MLVA-16 and its MLVA-11 subset were used to determine the genotypes of 68 B. suis bv. 2 isolates from Hungary and results were then compared to European MLVA genotypes. The analyses indicated relatively high genetic diversity of B. suis bv. 2 in Hungary. Strains isolated from hares and wild boars from Hungary showed substantial genetic divergence, suggesting separate lineages in each host and no instances of cross species infections. The closest relatives of strains from Hungarian wild boars and domestic pigs were mainly in the isolates from German and Croatian boars and pigs. The assessment of the European MLVA genotypes of wild boar isolates generally showed clustering based on geographic origin. The hare strains were relatively closely related to one another and did not cluster based on geographic origin. The limited relationships between geographic origin and genotype in isolates from hares might be the result of cross-border live animal translocation. The results could also suggest that certain B. suis strains are more adapted to hares. Across Europe, isolates from domestic pigs were closely related to isolates originating from both hares and wild boars, supporting the idea that wild animals are a source of brucellosis in domestic pigs.

  13. Identification and characterization of PhoP regulon members in Yersinia pestis biovar Microtus

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    Du Zongmin

    2008-03-01

    Full Text Available Abstract Background The transcription regulator PhoP has been shown to be important for Y. pestis survival in macrophages and under various in vitro stresses. However, the mechanism by which PhoP promotes bacterial intracellular survival is not fully understood. Our previous microarray analysis suggested that PhoP governed a wide set of cellular pathways in Y. pestis. A series of biochemical experiments were done herein to study members of the PhoP regulon of Y. pestis biovar Microtus. Results By using gel mobility shift assay and quantitative RT-PCR, a total of 30 putative transcription units were characterized as direct PhoP targets. The primer extension assay was further used to determine the transcription start sites of 18 PhoP-dependent promoters and to localize the -10 and -35 elements. The DNase I footprinting was used to identify the PhoP-binding sites within 17 PhoP-dependent promoters, enabling the identification of PhoP box and matrix that both represented the conserved signals for PhoP recognition in Y. pestis. Data presented here providing a good basis for modeling PhoP-promoter DNA interactions that is crucial to the PhoP-mediated transcriptional regulation. Conclusion The proven direct PhoP targets include nine genes encoding regulators and 21 genes or operons with functions of detoxification, protection against DNA damages, resistance to antimicrobial peptides, and adaptation to magnesium limitation. We can presume that PhoP is a global regulator that controls a complex regulatory cascade by a mechanism of not only directly controlling the expression of specific genes, but also indirectly regulating various cellular pathways by acting on a set of dedicated regulators. These results help us gain insights into the PhoP-dependent mechanisms by which Y. pestis survives the antibacterial strategies employed by host macrophages.

  14. Characterization of bacterial isolates from rotting potato tuber tissue showing antagonism to Dickeya sp. biovar 3 in vitro and in planta

    NARCIS (Netherlands)

    Czajkowski, R.L.; De Boer, W.J.; Van Veen, J.A.; Van der Wolf, J.M.

    2012-01-01

    Possibilities for biocontrol of biovar 3 Dickeya sp. in potato were investigated, using bacteria from rotting potato tissue isolated by dilution plating on nonselective agar media. In a plate assay, 649 isolates were screened for antibiosis against Dickeya sp. IPO2222 and for the production of

  15. Characterization of bacterial isolates from rotting potato tuber tissue showing antagonism to Dickeya sp. biovar 3 in vitro and in planta

    NARCIS (Netherlands)

    Czajkowski, R.L.; De Boer, W.J.; Van Veen, J.A.; Van der Wolf, J.M.

    2012-01-01

    Possibilities for biocontrol of biovar 3 Dickeya sp. in potato were investigated, using bacteria from rotting potato tissue isolated by dilution plating on nonselective agar media. In a plate assay, 649 isolates were screened for antibiosis against Dickeya sp. IPO2222 and for the production of sider

  16. Symbiotic plasmid is required for NolR to fully repress nodulation genes in Rhizobium leguminosarum A34

    Institute of Scientific and Technical Information of China (English)

    Fengqing Li; Bihe Hou; Guofan Hong

    2008-01-01

    NolR is a reguiator of noduiation genes present in Rhizobium and Sinorhizobium. However, the mechanism by which NolR participates in the inducible transcription ofnoduiation genes remains unclear. To investigate whether there are other factors regulating the function of NoIR, an insertion mutant of NolR in Rhizobium leguminosarum strain 8401, which lacks the symbiotic plasmid, was constructed by homologous recombination. We investigated the effects of NolR inactivation on the expression of nodulation genes. Three inducible nodulation genes (nodA, nodF and nodM) were expressed constitutively in NoiR-mutant, MRl14. Our results suggested that the symbiotic plasmid is required for NolR to fully repress nodulation genes in Rhizobium ieguminosarum A34. In addition, MRl14 has provided a useful tool for further study of molecular interactions between NolR and other factors.

  17. Iron requirement of Rhizobium leguminosarum and secretion of anthranilic acid during growth on an iron-deficient medium.

    Science.gov (United States)

    Rioux, C R; Jordan, D C; Rattray, J B

    1986-07-01

    Rhizobium leguminosarum GF160 required iron for growth under aerobic conditions in a chemically defined medium. Maximal growth of bacteria previously depleted in iron was obtained with approximately 50 microM unchelated ferric iron and with glucose as the only carbon source. Growth under iron deficiency did not result in the production of detectable levels of siderophores of either the catechol or hydroxamate types. Growing cells released a Fe3+-reducing agent that was identified as anthranilic acid by paper and thin-layer chromatography, ultraviolet and nuclear magnetic resonance spectroscopy, and mass spectrometry. The amount of anthranilic acid secreted per unit of cell growth was inversely related to the iron concentration in the culture medium and reached concentrations up to 1 mM. Ferric but not ferrous ions were solubilized in the growth medium by anthranilic acid.

  18. PssP2 is a polysaccharide co-polymerase involved in exopolysaccharide chain-length determination in Rhizobium leguminosarum.

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    Małgorzata Marczak

    Full Text Available Production of extracellular polysaccharides is a complex process engaging proteins localized in different subcellular compartments, yet communicating with each other or even directly interacting in multicomponent complexes. Proteins involved in polymerization and transport of exopolysaccharide (EPS in Rhizobium leguminosarum are encoded within the chromosomal Pss-I cluster. However, genes implicated in polysaccharide synthesis are common in rhizobia, with several homologues of pss genes identified in other regions of the R. leguminosarum genome. One such region is chromosomally located Pss-II encoding proteins homologous to known components of the Wzx/Wzy-dependent polysaccharide synthesis and transport systems. The pssP2 gene encodes a protein similar to polysaccharide co-polymerases involved in determination of the length of polysaccharide chains in capsule and O-antigen biosynthesis. In this work, a mutant with a disrupted pssP2 gene was constructed and its capabilities to produce EPS and enter into a symbiotic relationship with clover were studied. The pssP2 mutant, while not altered in lipopolysaccharide (LPS, displayed changes in molecular mass distribution profile of EPS. Lack of the full-length PssP2 protein resulted in a reduction of high molecular weight EPS, yet polymerized to a longer length than in the RtTA1 wild type. The mutant strain was also more efficient in symbiotic performance. The functional interrelation between PssP2 and proteins encoded within the Pss-I region was further supported by data from bacterial two-hybrid assays providing evidence for PssP2 interactions with PssT polymerase, as well as glycosyltransferase PssC. A possible role for PssP2 in a complex involved in EPS chain-length determination is discussed.

  19. Involvement of diamine oxidase and peroxidase in insolubilization of the extracellular matrix: implications for pea nodule initiation by Rhizobium leguminosarum.

    Science.gov (United States)

    Wisniewski, J P; Rathbun, E A; Knox, J P; Brewin, N J

    2000-04-01

    Rhizobium leguminosarum colonizes host cells and tissues through infection threads, which are tubular in-growths of the plant cell wall. Monoclonal antibody MAC265 recognizes a plant matrix glycoprotein (MGP) associated with the lumen of these infection threads. This glycoprotein is also released in soluble form from the root tips of pea seedlings. In the presence of hydrogen peroxide, release of glycoprotein from root tips was not observed. Extractability from root tips was therefore used as the basis for investigating the peroxide-driven insolubilization of MGP and the possible involvement of two extracellular enzymes, peroxidase (POD) and diamine oxidase (DAO), was investigated. Release of MGP from root tips was enhanced by application of POD and DAO inhibitors (salicylhydroxamic acid and o-phenanthroline, respectively). Furthermore, release of MGP was inhibited by pretreatment of roots with putrescine (the substrate of DAO) and also by application of a partially purified extract of DAO from pea shoots. Following inoculation of pea roots with R. leguminosarum, elevated levels of DAO transcript were observed by reverse transcriptase-polymerase chain reaction (RT-PCR), but these then dropped to a low level from 4 to 10 days post inoculation, rising again in more mature nodules. In situ hybridization studies indicated that the bulk of the transcription was associated with the infected tissue in the center of the nodule. On the basis of these observations, we postulate that DAO may be involved in the peroxide-driven hardening of MGP in the lumen of infection threads and in the intercellular matrix.

  20. Structural Variabilities in β-Lactamase (blaA of Different Biovars of Yersinia enterocolitica: Implications for β-Lactam Antibiotic and β-Lactamase Inhibitor Susceptibilities.

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    Neelja Singhal

    Full Text Available Yersiniosis caused by Yersinia enterocolitica has been reported from all continents. The bacterial species is divided into more than fifty serovars and six biovars viz. 1A, 1B, 2, 3, 4 and 5 which differ in geographical distribution, ecological niches and pathogenicity. Most Y.enterocolitica strains harbor chromosomal genes for two β-lactamases, blaA an Ambler class A penicillinase and blaB an Ambler class C inducible cephalosporinase. In the present study, susceptibility to b-lactam antibiotics and β-lactamase inhibitor was studied for Y. enterocolitica strains of biovars 1A, 1B, 2 and 4. We observed that β-lactamases were expressed differentially among strains of different biovars. To understand the molecular mechanisms underlying such differential expression, the sequences of genes and promoters of blaA were compared. Also, the variants of blaA present in different biovars were modeled and docked with amoxicillin and clavulanic acid. The mRNA secondary structures of blaA variants were also predicted in-silico. Our findings indicated that neither variations in the promoter regions, nor the secondary structures of mRNA contributed to higher/lower expression of blaA in different biovars. Analysis of H-bonding residues of blaA variants with amoxicillin and clavulanic acid revealed that if amino acid residues of a β-lactamase interacting with amoxicillin and the clavulanic acid were similar, clavulanic acid was effective in engaging the enzyme, accounting for a significant reduction in MIC of amoxicillin-clavulanate. This finding might aid in designing better β-lactamase inhibitors with improved efficiencies in future.

  1. Structural Variabilities in β-Lactamase (blaA) of Different Biovars of Yersinia enterocolitica: Implications for β-Lactam Antibiotic and β-Lactamase Inhibitor Susceptibilities.

    Science.gov (United States)

    Singhal, Neelja; Srivastava, Abhishikha; Kumar, Manish; Virdi, Jugsharan Singh

    2014-01-01

    Yersiniosis caused by Yersinia enterocolitica has been reported from all continents. The bacterial species is divided into more than fifty serovars and six biovars viz. 1A, 1B, 2, 3, 4 and 5 which differ in geographical distribution, ecological niches and pathogenicity. Most Y.enterocolitica strains harbor chromosomal genes for two β-lactamases, blaA an Ambler class A penicillinase and blaB an Ambler class C inducible cephalosporinase. In the present study, susceptibility to b-lactam antibiotics and β-lactamase inhibitor was studied for Y. enterocolitica strains of biovars 1A, 1B, 2 and 4. We observed that β-lactamases were expressed differentially among strains of different biovars. To understand the molecular mechanisms underlying such differential expression, the sequences of genes and promoters of blaA were compared. Also, the variants of blaA present in different biovars were modeled and docked with amoxicillin and clavulanic acid. The mRNA secondary structures of blaA variants were also predicted in-silico. Our findings indicated that neither variations in the promoter regions, nor the secondary structures of mRNA contributed to higher/lower expression of blaA in different biovars. Analysis of H-bonding residues of blaA variants with amoxicillin and clavulanic acid revealed that if amino acid residues of a β-lactamase interacting with amoxicillin and the clavulanic acid were similar, clavulanic acid was effective in engaging the enzyme, accounting for a significant reduction in MIC of amoxicillin-clavulanate. This finding might aid in designing better β-lactamase inhibitors with improved efficiencies in future.

  2. Structural Variabilities in β-Lactamase (blaA) of Different Biovars of Yersinia enterocolitica: Implications for β-Lactam Antibiotic and β-Lactamase Inhibitor Susceptibilities

    Science.gov (United States)

    Singhal, Neelja; Srivastava, Abhishikha; Kumar, Manish; Virdi, Jugsharan Singh

    2015-01-01

    Yersiniosis caused by Yersinia enterocolitica has been reported from all continents. The bacterial species is divided into more than fifty serovars and six biovars viz. 1A, 1B, 2, 3, 4 and 5 which differ in geographical distribution, ecological niches and pathogenicity. Most Y.enterocolitica strains harbor chromosomal genes for two β-lactamases, blaA an Ambler class A penicillinase and blaB an Ambler class C inducible cephalosporinase. In the present study, susceptibility to b-lactam antibiotics and β-lactamase inhibitor was studied for Y. enterocolitica strains of biovars 1A, 1B, 2 and 4. We observed that β-lactamases were expressed differentially among strains of different biovars. To understand the molecular mechanisms underlying such differential expression, the sequences of genes and promoters of blaA were compared. Also, the variants of blaA present in different biovars were modeled and docked with amoxicillin and clavulanic acid. The mRNA secondary structures of blaA variants were also predicted in-silico. Our findings indicated that neither variations in the promoter regions, nor the secondary structures of mRNA contributed to higher/lower expression of blaA in different biovars. Analysis of H-bonding residues of blaA variants with amoxicillin and clavulanic acid revealed that if amino acid residues of a β-lactamase interacting with amoxicillin and the clavulanic acid were similar, clavulanic acid was effective in engaging the enzyme, accounting for a significant reduction in MIC of amoxicillin-clavulanate. This finding might aid in designing better β-lactamase inhibitors with improved efficiencies in future. PMID:25919756

  3. Draft Genome Sequences of Brucella suis Biovar 4 Strain NCTC 10385, Brucella ceti Strain NCTC 12891T , Brucella inopinata Strain CAMP 6436T, and Brucella neotomae Strain ATCC 23459T

    OpenAIRE

    Wahab, Tara; Ferrari, Sevinc; Lindberg, Martina; Bäckman, Stina; Kaden, Rene

    2014-01-01

    With the aim of developing quantitative PCR methods for the detection and differentiation of Brucella species, the genomes of Brucella ceti, Brucella inopinata, Brucella netotomae, and Brucella suis biovar 4 were sequenced and analyzed.

  4. Draft Genome Sequences of Brucella suis Biovar 4 Strain NCTC 10385, Brucella ceti Strain NCTC 12891T, Brucella inopinata Strain CAMP 6436T, and Brucella neotomae Strain ATCC 23459T

    OpenAIRE

    Wahab, Tara; Ferrari, Sevinc; Lindberg, Martina; Bäckman, Stina; Kaden, Rene

    2014-01-01

    With the aim of developing quantitative PCR methods for the detection and differentiation of Brucella species, the genomes of Brucella ceti, Brucella inopinata, Brucella netotomae, and Brucella suis biovar 4 were sequenced and analyzed.

  5. Identification and characterization of the alpha-acetolactate synthase gene from Lactococcus lactis subsp. lactis biovar diacetylactis.

    Science.gov (United States)

    Marugg, J D; Goelling, D; Stahl, U; Ledeboer, A M; Toonen, M Y; Verhue, W M; Verrips, C T

    1994-01-01

    The conversion of 3-13C-labelled pyruvate in an acetoin-producing clone from a Lactococcus lactis subsp. lactis biovar diacetylactis strain DSM 20384 plasmid bank in Escherichia coli was studied by 13C nuclear magnetic resonance analysis. The results showed that alpha-acetolactate was the first metabolic product formed from pyruvate, whereas acetoin appeared at a much slower rate and reached only low concentrations. This alpha-acetolactate production shows that the cells express the gene for alpha-acetolactate synthase (als). Nucleotide sequence analysis identified an open reading frame encoding a protein of 554 amino acids. The deduced amino acid sequence exhibits extensive similarities to those of known alpha-acetolactate synthases from both prokaryotes and eukaryotes. The als gene is expressed on a monocistronic transcriptional unit, which is transcribed from a promoter located just upstream of the coding region. Images PMID:8017926

  6. Epidemiological investigation of the first human brucellosis case in Spain due to Brucella suis biovar 1 strain 1330.

    Science.gov (United States)

    Compés Dea, Cecilia; Guimbao Bescós, Joaquín; Alonso Pérez de Ágreda, Juan Pablo; Muñoz Álvaro, Pilar María; Blasco Martínez, José María; Villuendas Usón, María Cruz

    2017-03-01

    No cases of human brucellosis caused by Brucella suis has been reported in Spain. This study involved interviews with the case and his co-workers, inspection of their workplace, checking infection control measures, and typing the Brucella strain isolated in the blood culture. Brucella suis biovar 1 strain 1330 was isolated from a patient who worked in a waste treatment plant. Food borne transmission, contact with animals, and risk jobs were ruled out. An accidental inoculation with a contaminated needle from a research laboratory waste container was identified as the most probable mode of transmission. There should be controls to ensure that waste containers are sealed. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

  7. Seminal vesiculitis and orchitis caused by Brucella abortus biovar 1 in young bison bulls from South Dakota.

    Science.gov (United States)

    Rhyan, J C; Holland, S D; Gidlewski, T; Saari, D A; Jensen, A E; Ewalt, D R; Hennager, S G; Olsen, S C; Cheville, N F

    1997-10-01

    Specimens of blood, lymph nodes, spleens, and genitalia were collected at slaughter from seven 3- and 4-year-old male bison that had recently become seropositive for brucellosis. The animals were from a captive herd of approximately 3,500 bison located in central South Dakota. Brucella abortus biovar 1 was isolated from 2 or more specimens from each of 6 bison. Severe necrotizing and pyogranulomatous orchitis was present in 1 testicle from 1 bull, and 4 animals had mild to marked seminal vesiculitis. Immunohistochemical staining labeled organisms in seminal vesicles and the testicle with orchitis. Ultrastructurally, intact bacilli were present in cytoplasmic vacuoles of some macrophages; other macrophages contained intracytoplasmic aggregates of calcified coccobacilli.

  8. Effects of distilled Phaseoli Semen rubra Herbal-Acupuncture on lipid composition, liver function, antioxidant capacity and molecular biological aspects in obese rats induced high fat diet

    Directory of Open Access Journals (Sweden)

    Ji, Jun Hwan

    2005-06-01

    Full Text Available Effects of Phaseoli Semen rubra Herbal-acupuncture at zusanli(ST-36, Quchi(LI-11 and Sanyinjiao(Sp-6 on lipid composition, liver function, oxidative capacity and molecular biological aspects were investigate in high fat diet induced obese rats. Forty male Sprague-Dawley rats weighing about 400g were divided into 4 groups according to body weight and raised four weeks with control, zusanli(ST-36, Quchi(LI-11 and Sanyinjiao(Sp-6 Herbal-acupuncture groups. 1. Plasma total cholesterol and LDL-cholesterol showed a low values in the (ST-36 and (LI-11 Herbal-acupuncture groups and HDL- cholesterol showed a high values in the (ST-36 Herbal-acupuncture groups. 2. Plasma triglyceride and glucose showed a low values in the (ST-36 and (LI-11 Herbal-acupuncture groups. 3. The contents of plasma free fatty acids showed a tendence to decrease in the Herbal-acupuncture groups, however in the Herbal-acupuncture groups, the values showed no significantly different. 4. The activities of AST and ALT showed no significantly different in all treatment groups. 5. The contents of plasma β-lipoprotein and free fatty acids showed a tendency to decrease in the Herbal-acupuncture groups compared to those of control group. In the Herbal-acupuncture groups, the values of (ST-36 and (LI-11 Herbal-acupuncture groups showed a low in the acupuncture groups. 6. Liver total cholesterol and triglyceride showed a low values in the (ST-36 and (LI-11 Herbal-acupuncture groups. 7. Contents of plasma TBARS showed a low values in the (ST-36 and (LI-11 Herbal-acupuncture groups, however contents of liver TBARS showed no significantly different among treatment groups. 8. Values of liver glutathione peroxidase and catalase activity showed a tendency to increase in the (ST-36 and (LI-11 Herbal-acupuncture groups. Values of liver super oxide dismutase activity showed a high in the (ST-36 Herbal-acupuncture groups compared to those of other groups. 9. Expression of apo-B mRNA in liver cell

  9. Differentially Expressed Genes in Resistant and Susceptible Common Bean (Phaseolus vulgaris L. Genotypes in Response to Fusarium oxysporum f. sp. phaseoli.

    Directory of Open Access Journals (Sweden)

    Renfeng Xue

    Full Text Available Fusarium wilt of common bean (Phaseolus vulgaris L., caused by Fusarium oxysporum Schlechtend.:Fr. f.sp. phaseoli (Fop, is one of the most important diseases of common beans worldwide. Few natural sources of resistance to Fop exist and provide only moderate or partial levels of protection. Despite the economic importance of the disease across multiple crops, only a few of Fop induced genes have been analyzed in legumes. Therefore, our goal was to identify transcriptionally regulated genes during an incompatible interaction between common bean and the Fop pathogen using the cDNA amplified fragment length polymorphism (cDNA-AFLP technique. We generated a total of 8,730 transcript-derived fragments (TDFs with 768 primer pairs based on the comparison of a moderately resistant and a susceptible genotype. In total, 423 TDFs (4.9% displayed altered expression patterns after inoculation with Fop inoculum. We obtained full amplicon sequences for 122 selected TDFs, of which 98 were identified as annotated known genes in different functional categories based on their putative functions, 10 were predicted but non-annotated genes and 14 were not homologous to any known genes. The 98 TDFs encoding genes of known putative function were classified as related to metabolism (22, signal transduction (21, protein synthesis and processing (20, development and cytoskeletal organization (12, transport of proteins (7, gene expression and RNA metabolism (4, redox reactions (4, defense and stress responses (3, energy metabolism (3, and hormone responses (2. Based on the analyses of homology, 19 TDFs from different functional categories were chosen for expression analysis using quantitative RT-PCR. The genes found to be important here were implicated at various steps of pathogen infection and will allow a better understanding of the mechanisms of defense and resistance to Fop and similar pathogens. The differential response genes discovered here could also be used as

  10. Differentially Expressed Genes in Resistant and Susceptible Common Bean (Phaseolus vulgaris L.) Genotypes in Response to Fusarium oxysporum f. sp. phaseoli.

    Science.gov (United States)

    Xue, Renfeng; Wu, Jing; Zhu, Zhendong; Wang, Lanfen; Wang, Xiaoming; Wang, Shumin; Blair, Matthew W

    2015-01-01

    Fusarium wilt of common bean (Phaseolus vulgaris L.), caused by Fusarium oxysporum Schlechtend.:Fr. f.sp. phaseoli (Fop), is one of the most important diseases of common beans worldwide. Few natural sources of resistance to Fop exist and provide only moderate or partial levels of protection. Despite the economic importance of the disease across multiple crops, only a few of Fop induced genes have been analyzed in legumes. Therefore, our goal was to identify transcriptionally regulated genes during an incompatible interaction between common bean and the Fop pathogen using the cDNA amplified fragment length polymorphism (cDNA-AFLP) technique. We generated a total of 8,730 transcript-derived fragments (TDFs) with 768 primer pairs based on the comparison of a moderately resistant and a susceptible genotype. In total, 423 TDFs (4.9%) displayed altered expression patterns after inoculation with Fop inoculum. We obtained full amplicon sequences for 122 selected TDFs, of which 98 were identified as annotated known genes in different functional categories based on their putative functions, 10 were predicted but non-annotated genes and 14 were not homologous to any known genes. The 98 TDFs encoding genes of known putative function were classified as related to metabolism (22), signal transduction (21), protein synthesis and processing (20), development and cytoskeletal organization (12), transport of proteins (7), gene expression and RNA metabolism (4), redox reactions (4), defense and stress responses (3), energy metabolism (3), and hormone responses (2). Based on the analyses of homology, 19 TDFs from different functional categories were chosen for expression analysis using quantitative RT-PCR. The genes found to be important here were implicated at various steps of pathogen infection and will allow a better understanding of the mechanisms of defense and resistance to Fop and similar pathogens. The differential response genes discovered here could also be used as molecular

  11. Draft Genome Sequence of Highly Virulent Race 4/Biovar 3 of Ralstonia solanacearum CaRs_Mep Causing Bacterial Wilt in Zingiberaceae Plants in India

    Science.gov (United States)

    Munjal, Vibhuti; Sheoran, Neelam; Prameela, Thekkan Puthiyaveedu; Suseelabhai, Rajamma; Aggarwal, Rashmi; Jain, Rakesh Kumar; Eapen, Santhosh J.

    2017-01-01

    ABSTRACT The genome of Ralstonia solanacearum CaRs_Mep, a race 4/biovar 3/phylotype I bacterium causing wilt in small cardamom and other Zingiberaceae plants, was sequenced. Analysis of the 5.7-Mb genome sequence will aid in better understanding of the genetic determinants of host range, host jump, survival, pathogenicity, and virulence of race 4 of R. solanacearum. PMID:28057749

  12. Genetic relationships between clinical and non-clinical strains of Yersinia enterocolitica biovar 1A as revealed by multilocus enzyme electrophoresis and multilocus restriction typing

    Directory of Open Access Journals (Sweden)

    Virdi Jugsharan S

    2010-05-01

    Full Text Available Abstract Background Genetic relationships among 81 strains of Y. enterocolitica biovar 1A isolated from clinical and non-clinical sources were discerned by multilocus enzyme electrophoresis (MLEE and multilocus restriction typing (MLRT using six loci each. Such studies may reveal associations between the genotypes of the strains and their sources of isolation. Results All loci were polymorphic and generated 62 electrophoretic types (ETs and 12 restriction types (RTs. The mean genetic diversity (H of the strains by MLEE and MLRT was 0.566 and 0.441 respectively. MLEE (DI = 0.98 was more discriminatory and clustered Y. enterocolitica biovar 1A strains into four groups, while MLRT (DI = 0.77 identified two distinct groups. BURST (Based Upon Related Sequence Types analysis of the MLRT data suggested aquatic serotype O:6,30-6,31 isolates to be the ancestral strains from which, clinical O:6,30-6,31 strains might have originated by host adaptation and genetic change. Conclusion MLEE revealed greater genetic diversity among strains of Y. enterocolitica biovar 1A and clustered strains in four groups, while MLRT grouped the strains into two groups. BURST analysis of MLRT data nevertheless provided newer insights into the probable evolution of clinical strains from aquatic strains.

  13. Interaction of Yersinia enterocolitica biovar 1A with cultured cells in vitro does not reflect the two previously identified clonal groups.

    Science.gov (United States)

    Dhar, Mahesh S; Virdi, Jugsharan S

    2013-12-01

    Yersinia enterocolitica biovar 1A strains have been delineated into two clonal groups (A and B) based on repetitive extragenic palindrome- and enterobacterial repetitive intergenic consensus-PCR genotyping. The present study investigated the interaction of Y. enterocolitica biovar 1A strains with cultured cells in vitro by their ability to adhere, invade and survive within these cells. The response of macrophages to these strains was also studied by quantifying the expression of inducible nitric oxide synthase, production of nitric oxide and cytokines, and activation of NFκB. The survival rate of clonal group B strains inside macrophages was significantly higher than that of clonal group A strains. In addition, strains harbouring the fepA gene showed better survival inside macrophages. However, the production of nitric oxide and cytokines and activation of NFκB did not show any significant differences between the two clonal groups. In this study, interaction of Y. enterocolitica biovar 1A with cultured cells in vitro did not reflect the previously identified clonal groups, but was more dependent on the characteristics of the individual strains. Therefore, a combination of genotype and phenotype data must be used to characterize this extremely heterogeneous organism.

  14. Characterisation of SalRAB a salicylic acid inducible positively regulated efflux system of Rhizobium leguminosarum bv viciae 3841.

    Science.gov (United States)

    Tett, Adrian J; Karunakaran, Ramakrishnan; Poole, Philip S

    2014-01-01

    Salicylic acid is an important signalling molecule in plant-microbe defence and symbiosis. We analysed the transcriptional responses of the nitrogen fixing plant symbiont, Rhizobium leguminosarum bv viciae 3841 to salicylic acid. Two MFS-type multicomponent efflux systems were induced in response to salicylic acid, rmrAB and the hitherto undescribed system salRAB. Based on sequence similarity salA and salB encode a membrane fusion and inner membrane protein respectively. salAB are positively regulated by the LysR regulator SalR. Disruption of salA significantly increased the sensitivity of the mutant to salicylic acid, while disruption of rmrA did not. A salA/rmrA double mutation did not have increased sensitivity relative to the salA mutant. Pea plants nodulated by salA or rmrA strains did not have altered nodule number or nitrogen fixation rates, consistent with weak expression of salA in the rhizosphere and in nodule bacteria. However, BLAST analysis revealed seventeen putative efflux systems in Rlv3841 and several of these were highly differentially expressed during rhizosphere colonisation, host infection and bacteroid differentiation. This suggests they have an integral role in symbiosis with host plants.

  15. Multiplicity of Sulfate and Molybdate Transporters and Their Role in Nitrogen Fixation in Rhizobium leguminosarum bv. viciae Rlv3841.

    Science.gov (United States)

    Cheng, Guojun; Karunakaran, Ramakrishnan; East, Alison K; Poole, Philip S

    2016-02-01

    Rhizobium leguminosarum Rlv3841 contains at least three sulfate transporters, i.e., SulABCD, SulP1 and SulP2, and a single molybdate transporter, ModABC. SulABCD is a high-affinity transporter whose mutation prevented growth on a limiting sulfate concentration, while SulP1 and SulP2 appear to be low-affinity sulfate transporters. ModABC is the sole high-affinity molybdate transport system and is essential for growth with NO3(-) as a nitrogen source on limiting levels of molybdate (molybdate, a quadruple mutant with all four transporters inactivated, had the longest lag phase on NO3(-), suggesting these systems all make some contribution to molybdate transport. Growth of Rlv3841 on limiting levels of sulfate increased sulB, sulP1, modB, and sulP2 expression 313.3-, 114.7-, 6.2-, and 4.0-fold, respectively, while molybdate starvation increased only modB expression (three- to 7.5-fold). When grown in high-sulfate but not low-sulfate medium, pea plants inoculated with LMB695 (modB) reduced acetylene at only 14% of the wild-type rate, and this was not further reduced in the quadruple mutant. Overall, while modB is crucial to nitrogen fixation at limiting molybdate levels in the presence of sulfate, there is an unidentified molybdate transporter also capable of sulfate transport.

  16. Characterisation of SalRAB a salicylic acid inducible positively regulated efflux system of Rhizobium leguminosarum bv viciae 3841.

    Directory of Open Access Journals (Sweden)

    Adrian J Tett

    Full Text Available Salicylic acid is an important signalling molecule in plant-microbe defence and symbiosis. We analysed the transcriptional responses of the nitrogen fixing plant symbiont, Rhizobium leguminosarum bv viciae 3841 to salicylic acid. Two MFS-type multicomponent efflux systems were induced in response to salicylic acid, rmrAB and the hitherto undescribed system salRAB. Based on sequence similarity salA and salB encode a membrane fusion and inner membrane protein respectively. salAB are positively regulated by the LysR regulator SalR. Disruption of salA significantly increased the sensitivity of the mutant to salicylic acid, while disruption of rmrA did not. A salA/rmrA double mutation did not have increased sensitivity relative to the salA mutant. Pea plants nodulated by salA or rmrA strains did not have altered nodule number or nitrogen fixation rates, consistent with weak expression of salA in the rhizosphere and in nodule bacteria. However, BLAST analysis revealed seventeen putative efflux systems in Rlv3841 and several of these were highly differentially expressed during rhizosphere colonisation, host infection and bacteroid differentiation. This suggests they have an integral role in symbiosis with host plants.

  17. Complete genome sequence of Rhizobium leguminosarum bv. trifolii strain WSM1325, an effective microsymbiont of annual Mediterranean clovers.

    Energy Technology Data Exchange (ETDEWEB)

    Reeve, Wayne [Murdoch University, Perth, Australia; O' Hara, Graham [Murdoch University, Perth, Australia; Chain, Patrick S. G. [Lawrence Livermore National Laboratory (LLNL); Ardley, Julie [Murdoch University, Perth, Australia; Brau, Lambert [Murdoch University, Perth, Australia; Nandesena, Kemanthi [Murdoch University, Perth, Australia; Tiwari, Ravi [Murdoch University, Perth, Australia; Copeland, A [U.S. Department of Energy, Joint Genome Institute; Nolan, Matt [U.S. Department of Energy, Joint Genome Institute; Han, Cliff [Los Alamos National Laboratory (LANL); Brettin, Thomas S [ORNL; Land, Miriam L [ORNL; Ovchinnikova, Galina [U.S. Department of Energy, Joint Genome Institute; Ivanova, N [U.S. Department of Energy, Joint Genome Institute; Mavromatis, K [U.S. Department of Energy, Joint Genome Institute; Markowitz, Victor [U.S. Department of Energy, Joint Genome Institute; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Melino, Vanessa [Murdoch University, Perth, Australia; Denton, Matthew [Department of Primary Industries, Victoria, Australia; Yates, Ron [Murdoch University, Perth, Australia; Howieson, John [Murdoch University, Perth, Australia

    2010-01-01

    Rhizobium leguminosarum bv trifolii is a soil-inhabiting bacterium that that has the capacity to be an effective nitrogen fixing microsymbiont of a diverse range of annual Trifolium (clover) species. Strain WSM1325 is an aerobic, motile, non-spore forming, Gram-negative rod isolated from root nodules collected in 1993 from the Greek Island of Serifos. WSM1325 is manufactured commercially in Australia as an inoculant for a broad range of annual clovers of Mediterranean origin due to its superior attributes of saprophytic competence, nitrogen fixation and acid-tolerance. Here we describe the basic features of this organism, together with the complete genome sequence, and annotation. This is the first completed genome sequence for a microsymbiont of annual clovers. We reveal that its genome size is 7,418,122 bp encoding 7,232 protein-coding genes and 61 RNA-only encoding genes. This multipartite genome contains 6 distinct replicons; a chromosome of size 4,767,043 bp and 5 plasmids of size 828,924, 660,973, 516,088, 350,312 and 294,782 bp.

  18. Calcium-dependent regulation of genes for plant nodulation in Rhizobium leguminosarum detected by iTRAQ quantitative proteomic analysis.

    Science.gov (United States)

    Arrigoni, Giorgio; Tolin, Serena; Moscatiello, Roberto; Masi, Antonio; Navazio, Lorella; Squartini, Andrea

    2013-11-01

    Rhizobia, the nitrogen-fixing bacterial symbionts of legumes, represent an agricultural application of primary relevance and a model of plant-microbe molecular dialogues. We recently described rhizobium proteome alterations induced by plant flavonoids using iTRAQ. Herein, we further extend that experimentation, proving that the transient elevation in cytosolic calcium is a key signaling event necessary for the expression of the nodulation (nod) genes. Ca(2+) involvement in nodulation is a novel issue that we recently flagged with genetic and physiological approaches and that hereby we demonstrate also by proteomics. Exploiting the multiple combinations of 4-plex iTRAQ, we analyzed Rhizobium leguminosarum cultures grown with or without the nod gene-inducing plant flavonoid naringenin and in the presence or absence of the extracellular Ca(2+) chelator EGTA. We quantified over a thousand proteins, 189 of which significantly altered upon naringenin and/or EGTA stimulation. The expression of NodA, highly induced by naringenin, is strongly reduced when calcium availability is limited by EGTA. This confirms, from a proteomic perspective, that a Ca(2+) influx is a necessary early step in flavonoid-mediated legume nodulation by rhizobia. We also observed other proteins affected by the different treatments, whose identities and roles in nodulation and rhizobium physiology are likewise discussed.

  19. Alterações metabólicas em plantas de feijão originadas de sementes microbiolizadas por Pseudomonas sp. e inoculadas com Xanthomonas axonopodis pv. phaseoli Metabolic alterations on bean plants originated from microbiolization of seeds with Pseudomonas sp. and inoculated with Xanthomnas axonopodis pv. phaseoli

    Directory of Open Access Journals (Sweden)

    Eliane Gonçalves da Silva

    2009-06-01

    Full Text Available Muitas enzimas estão envolvidas em reações de defesa de plantas contra patógenos. O objetivo deste trabalho foi verificar alterações na atividade de algumas destas enzimas em plantas de feijão originadas de sementes microbiolizadas com um isolado de Pseudomonas do grupo das fluorescentes (isolado DFs842. Sementes de feijão cultivar BRS Valente foram imersas em suspensão salina preparada a partir de crescimento bacteriano com 24 h do isolado de Pseudomonas (OD540=0,5 sabidamente biocontroladora de Xanthomonas axonopodis pv. phaseoli. Como testemunhas, as sementes foram imersas em solução salina (NaCl 0,85%. Após a microbiolização por 5 h a 10ºC, as sementes foram plantadas em vasos contendo uma mistura de solo não esterilizado, areia e esterco bovino (proporção 3:1:1, mantidos em casa de vegetação. A inoculação do patógeno foi realizada na terceira folha verdadeira de todas as plantas, fazendo-se cortes com tesoura imersa em suspensão salina do patógeno (X. axonopodis pv. phaseoli preparada a partir de crescimento de 24 h (OD540=0,4. Câmaras úmidas foram mantidas 24 h antes e após a inoculação. Para o preparo do extrato protéico, as três primeiras folhas verdadeiras foram coletadas individualmente em 5 épocas de coleta distintas: uma, momentos antes da inoculação e as demais nos tempos seis, 24, 72 h e 15 dias após a inoculação. Este extrato protéico serviu de fonte para as determinações do teor de proteínas solúveis totais (PST, atividade da polifenol oxidase (PPO e da peroxidase (PO, as quais foram realizadas por leituras espectrofotométricas. Os resultados demonstraram aumento significativo no teor de PST e na atividade de PPO nas plantas submetidas ao tratamento com isolado DFs842, sendo que, o teor de PST foi o dobro, em relação às plantas não tratadas. Também foi observado que, mesmo antes da inoculação do patógeno o teor de PST e a atividade de PPO nas plantas tratadas estavam bem maiores

  20. Rhizobium meliloti and Rhizobium leguminosarum dctD gene products bind to tandem sites in an activation sequence located upstream of sigma 54-dependent dctA promoters.

    OpenAIRE

    Ledebur, H; Gu, B; Sojda, J; Nixon, B T

    1990-01-01

    Free-living rhizobia transport external C4-dicarboxylates to use as sole carbon sources, and uptake of these compounds is essential for nitrogen fixation by rhizobial bacteroids. In both Rhizobium leguminosarum and Rhizobium meliloti, the genes dctB and dctD are believed to form an ntrB/ntrC-like two-component system which regulates the synthesis of a C4-dicarboxylate transport protein encoded by dctA. Here we confirm the identity of sigma 54-dependent promoters previously hypothesized for th...

  1. Molekularbiologische und genetische Untersuchungen zur Regulation des zentralen Regulators der Stickstofffixierung NifA in Rhizobium leguminosarum bv. viciae VF39

    OpenAIRE

    Saeglitz, Nico

    2008-01-01

    Expression of nif and fix genes in rhizobia is strictly regulated. The dominating regulator within the regulation of nif and fix gene expression is NifA. This work presents, that two promotors are involved in nifA gene expression in Rhizobium leguminosarum bv. viciae VF39, namely P1, located at the downstream end of fixX and PfixA, the promotor of the fixA gene, located 3600bp upstream of P1. P2, a promotor identified by transcriptional mapping was shown to be pointless in earlier works and c...

  2. Rhizobium meliloti and Rhizobium leguminosarum dctD gene products bind to tandem sites in an activation sequence located upstream of sigma 54-dependent dctA promoters.

    OpenAIRE

    Ledebur, H; Gu, B.; Sojda, J; Nixon, B T

    1990-01-01

    Free-living rhizobia transport external C4-dicarboxylates to use as sole carbon sources, and uptake of these compounds is essential for nitrogen fixation by rhizobial bacteroids. In both Rhizobium leguminosarum and Rhizobium meliloti, the genes dctB and dctD are believed to form an ntrB/ntrC-like two-component system which regulates the synthesis of a C4-dicarboxylate transport protein encoded by dctA. Here we confirm the identity of sigma 54-dependent promoters previously hypothesized for th...

  3. Bacillus cereus Biovar Anthracis Causing Anthrax in Sub-Saharan Africa—Chromosomal Monophyly and Broad Geographic Distribution

    Science.gov (United States)

    Mabon, Philip; Zimmermann, Fee; Lankester, Felix; Peller, Tianna; Feistner, Anna; Todd, Angelique; Herbinger, Ilka; de Nys, Hélène M.; Muyembe-Tamfun, Jean-Jacques; Karhemere, Stomy; Wittig, Roman M.; Couacy-Hymann, Emmanuel; Grunow, Roland; Calvignac-Spencer, Sébastien; Corbett, Cindi R.; Klee, Silke R.; Leendertz, Fabian H.

    2016-01-01

    Through full genome analyses of four atypical Bacillus cereus isolates, designated B. cereus biovar anthracis, we describe a distinct clade within the B. cereus group that presents with anthrax-like disease, carrying virulence plasmids similar to those of classic Bacillus anthracis. We have isolated members of this clade from different mammals (wild chimpanzees, gorillas, an elephant and goats) in West and Central Africa (Côte d’Ivoire, Cameroon, Central African Republic and Democratic Republic of Congo). The isolates shared several phenotypic features of both B. anthracis and B. cereus, but differed amongst each other in motility and their resistance or sensitivity to penicillin. They all possessed the same mutation in the regulator gene plcR, different from the one found in B. anthracis, and in addition, carry genes which enable them to produce a second capsule composed of hyaluronic acid. Our findings show the existence of a discrete clade of the B. cereus group capable of causing anthrax-like disease, found in areas of high biodiversity, which are possibly also the origin of the worldwide distributed B. anthracis. Establishing the impact of these pathogenic bacteria on threatened wildlife species will require systematic investigation. Furthermore, the consumption of wildlife found dead by the local population and presence in a domestic animal reveal potential sources of exposure to humans. PMID:27607836

  4. Isolation and Identification of Brucella melitensis Biovar 3 from Vaccinated Small Ruminants: A Public Health Threat in Kosovo.

    Science.gov (United States)

    Hamidi, A; Mayer-Scholl, A; Dreshaj, S; Robaj, A; Sylejmani, D; Ramadani, N; Al Dahouk, S; Nöckler, K

    2016-12-01

    In 2011, a human brucellosis case with severe clinical symptoms was reported at the University Clinic for Infectious Diseases in Prishtina, Kosovo. A trace-back investigation was conducted to find the source of human infection. A total of 49 blood samples and 15 corresponding milk samples from sheep and goats raised on the patient's farm were taken for serological and molecular analysis. Serology using RBT and CFT revealed 11 positive animals. Twelve milk samples were PCR positive. A Brucella strain isolated from a goat's milk sample was classified as Brucella melitensis biovar 3, indicating the first ever isolation and report in Kosovo. The use of the Bruce-ladder PCR provided differentiation between the field strain and the vaccine strain. Hence, the accidental transmission of the vaccine strain Rev 1 that was previously used for the vaccination of the farm animals could be excluded. The findings of this study show that brucellosis is still a public health threat in Kosovo despite control measures. © 2015 Blackwell Verlag GmbH.

  5. Extended Multilocus Sequence Analysis to Describe the Global Population Structure of the Genus Brucella: Phylogeography and Relationship to Biovars

    Science.gov (United States)

    Whatmore, Adrian M.; Koylass, Mark S.; Muchowski, Jakub; Edwards-Smallbone, James; Gopaul, Krishna K.; Perrett, Lorraine L.

    2016-01-01

    An extended multilocus sequence analysis (MLSA) scheme applicable to the Brucella, an expanding genus that includes zoonotic pathogens that severely impact animal and human health across large parts of the globe, was developed. The scheme, which extends a previously described nine locus scheme by examining sequences at 21 independent genetic loci in order to increase discriminatory power, was applied to a globally and temporally diverse collection of over 500 isolates representing all 12 known Brucella species providing an expanded and detailed understanding of the population genetic structure of the group. Over 100 sequence types (STs) were identified and analysis of data provided insights into both the global evolutionary history of the genus, suggesting that early emerging Brucella abortus lineages might be confined to Africa while some later lineages have spread worldwide, and further evidence of the existence of lineages with restricted host or geographical ranges. The relationship between biovar, long used as a crude epidemiological marker, and genotype was also examined and showed decreasing congruence in the order Brucella suis > B. abortus > Brucella melitensis. Both the previously described nine locus scheme and the extended 21 locus scheme have been made available at http://pubmlst.org/brucella/ to allow the community to interrogate existing data and compare with newly generated data. PMID:28066370

  6. Transcriptomic Analysis of Yersinia enterocolitica Biovar 1B Infecting Murine Macrophages Reveals New Mechanisms of Extracellular and Intracellular Survival.

    Science.gov (United States)

    Bent, Zachary W; Poorey, Kunal; Brazel, David M; LaBauve, Annette E; Sinha, Anupama; Curtis, Deanna J; House, Samantha E; Tew, Karen E; Hamblin, Rachelle Y; Williams, Kelly P; Branda, Steven S; Young, Glenn M; Meagher, Robert J

    2015-07-01

    Yersinia enterocolitica is typically considered an extracellular pathogen; however, during the course of an infection, a significant number of bacteria are stably maintained within host cell vacuoles. Little is known about this population and the role it plays during an infection. To address this question and to elucidate the spatially and temporally dynamic gene expression patterns of Y. enterocolitica biovar 1B through the course of an in vitro infection, transcriptome sequencing and differential gene expression analysis of bacteria infecting murine macrophage cells were performed under four distinct conditions. Bacteria were first grown in a nutrient-rich medium at 26 °C to establish a baseline of gene expression that is unrelated to infection. The transcriptomes of these bacteria were then compared to bacteria grown in a conditioned cell culture medium at 37 °C to identify genes that were differentially expressed in response to the increased temperature and medium but not in response to host cells. Infections were then performed, and the transcriptomes of bacteria found on the extracellular surface and intracellular compartments were analyzed individually. The upregulated genes revealed potential roles for a variety of systems in promoting intracellular virulence, including the Ysa type III secretion system, the Yts2 type II secretion system, and the Tad pilus. It was further determined that mutants of each of these systems had decreased virulence while infecting macrophages. Overall, these results reveal the complete set of genes expressed by Y. enterocolitica in response to infection and provide the groundwork for future virulence studies.

  7. Resistance to amoxicillin-clavulanate and its relation to virulence-related factors in Yersinia enterocolitica biovar 1A

    Directory of Open Access Journals (Sweden)

    N Singhal

    2016-01-01

    Full Text Available Recent studies have reported that the virulence factors (VFs were detected more frequently in amoxicillin-clavulanate (AMC susceptible clinical isolates of Escherichia coli. Here, we have evaluated the relationship between VFs and AMC-resistance phenotype in clinical isolates of Y. enterocolitica biovar 1A. The presence/absence of VFs was compared with their minimum inhibitory concentrations for AMC in strains of two serovars. We observed that the strains of the serovar O: 6, 30-6, 31 showed a similar relationship between the number of VFs and resistance to clavulanic acid as in E. coli but not of serovar O: 6, 30. Variations in the promoters/complete coding sequences (CCDSs of β-lactamase gene (bla A or the serological characteristics could not account for unusual susceptibility to AMC displayed by the strains of the serovar O: 6, 30. Therefore, we speculate that since the clinical strains of serovar O: 6, 30-6, 31 originated from the environment they were less exposed to antibiotics compared to clinical strains of serovar O: 6, 30. Thus, AMC susceptibility seems to be influenced by factors other than serotypes or promoters/CCDS of β-lactamase genes.

  8. Resistance to amoxicillin-clavulanate and its relation to virulence-related factors in Yersinia enterocolitica biovar 1A.

    Science.gov (United States)

    Singhal, N; Kumar, M; Virdi, J S

    2016-01-01

    Recent studies have reported that the virulence factors (VFs) were detected more frequently in amoxicillin-clavulanate (AMC) susceptible clinical isolates of Escherichia coli. Here, we have evaluated the relationship between VFs and AMC-resistance phenotype in clinical isolates of Y. enterocolitica biovar 1A. The presence/absence of VFs was compared with their minimum inhibitory concentrations for AMC in strains of two serovars. We observed that the strains of the serovar O: 6, 30-6, 31 showed a similar relationship between the number of VFs and resistance to clavulanic acid as in E. coli but not of serovar O: 6, 30. Variations in the promoters/complete coding sequences (CCDSs) of β-lactamase gene (bla A) or the serological characteristics could not account for unusual susceptibility to AMC displayed by the strains of the serovar O: 6, 30. Therefore, we speculate that since the clinical strains of serovar O: 6, 30-6, 31 originated from the environment they were less exposed to antibiotics compared to clinical strains of serovar O: 6, 30. Thus, AMC susceptibility seems to be influenced by factors other than serotypes or promoters/CCDS of β-lactamase genes.

  9. MLVA as an Epidemiological Tool To Trace Back Brucella melitensis Biovar 1 Re-Emergence in Italy.

    Science.gov (United States)

    De Massis, F; Ancora, M; Atzeni, M; Rolesu, S; Bandino, E; Danzetta, M L; Zilli, K; Di Giannatale, E; Scacchia, M

    2015-10-01

    Brucellosis is an important zoonosis caused by Brucella spp., still prevalent in most areas of the world. Brucellosis control in animals is the key to protect humans. The knowledge of Brucella spp. prevailing genotypes in a territory represents an important epidemiological tool to formulate policies and strategies for disease control and to trace back the introduction of new strains previously considered as exotic. In the last years, multiple-locus variable number tandem repeat analysis (MLVA) has been proposed as complementary to classical biotyping methods. MLVA may add important information to the classical epidemiological investigation techniques, to help in tracing back sources of infection in brucellosis outbreaks. Sardinia is an Italian region officially free from sheep and goats brucellosis since 1998. In 2011, Brucella melitensis biovar 1, a biotype not reported in Italy since 1995, was isolated in one flock in the region. The genotyping MLVA-16 showed that isolates belonged to a rare American lineage, confirming it was introduced from other countries. The strain was considered as probably originating from Spain, where this lineage is endemic. BrucellaMLVA-16 has been proved to be useful to analyse the epidemiological correlation of strains enabling to trace its geographic origin by comparing their previously reported genetic patterns.

  10. Bacillus cereus Biovar Anthracis Causing Anthrax in Sub-Saharan Africa-Chromosomal Monophyly and Broad Geographic Distribution.

    Directory of Open Access Journals (Sweden)

    Kym S Antonation

    2016-09-01

    Full Text Available Through full genome analyses of four atypical Bacillus cereus isolates, designated B. cereus biovar anthracis, we describe a distinct clade within the B. cereus group that presents with anthrax-like disease, carrying virulence plasmids similar to those of classic Bacillus anthracis. We have isolated members of this clade from different mammals (wild chimpanzees, gorillas, an elephant and goats in West and Central Africa (Côte d'Ivoire, Cameroon, Central African Republic and Democratic Republic of Congo. The isolates shared several phenotypic features of both B. anthracis and B. cereus, but differed amongst each other in motility and their resistance or sensitivity to penicillin. They all possessed the same mutation in the regulator gene plcR, different from the one found in B. anthracis, and in addition, carry genes which enable them to produce a second capsule composed of hyaluronic acid. Our findings show the existence of a discrete clade of the B. cereus group capable of causing anthrax-like disease, found in areas of high biodiversity, which are possibly also the origin of the worldwide distributed B. anthracis. Establishing the impact of these pathogenic bacteria on threatened wildlife species will require systematic investigation. Furthermore, the consumption of wildlife found dead by the local population and presence in a domestic animal reveal potential sources of exposure to humans.

  11. Yersinia pestis biovar Microtus strain 201, an avirulent strain to humans, provides protection against bubonic plague in rhesus macaques.

    Science.gov (United States)

    Zhang, Qingwen; Wang, Qiong; Tian, Guang; Qi, Zhizhen; Zhang, Xuecan; Wu, Xiaohong; Qiu, Yefeng; Bi, Yujing; Yang, Xiaoyan; Xin, Youquan; He, Jian; Zhou, Jiyuan; Zeng, Lin; Yang, Ruifu; Wang, Xiaoyi

    2014-01-01

    Yersinia pestis biovar Microtus is considered to be a virulent to larger mammals, including guinea pigs, rabbits and humans. It may be used as live attenuated plague vaccine candidates in terms of its low virulence. However, the Microtus strain's protection against plague has yet to be demonstrated in larger mammals. In this study, we evaluated the protective efficacy of the Microtus strain 201 as a live attenuated plague vaccine candidate. Our results show that this strain is highly attenuated by subcutaneous route, elicits an F1-specific antibody titer similar to the EV and provides a protective efficacy similar to the EV against bubonic plague in Chinese-origin rhesus macaques. The Microtus strain 201 could induce elevated secretion of both Th1-associated cytokines (IFN-γ, IL-2 and TNF-α) and Th2-associated cytokines (IL-4, IL-5, and IL-6), as well as chemokines MCP-1 and IL-8. However, the protected animals developed skin ulcer at challenge site with different severity in most of the immunized and some of the EV-immunized monkeys. Generally, the Microtus strain 201 represented a good plague vaccine candidate based on its ability to generate strong humoral and cell-mediated immune responses as well as its good protection against high dose of subcutaneous virulent Y. pestis challenge.

  12. A Rhizobium leguminosarum CHDL- (Cadherin-Like-) Lectin Participates in Assembly and Remodeling of the Biofilm Matrix

    Science.gov (United States)

    Vozza, Nicolás F.; Abdian, Patricia L.; Russo, Daniela M.; Mongiardini, Elías J.; Lodeiro, Aníbal R.; Molin, Søren; Zorreguieta, Angeles

    2016-01-01

    In natural environments most bacteria live in multicellular structures called biofilms. These cell aggregates are enclosed in a self-produced polymeric extracellular matrix, which protects the cells, provides mechanical stability and mediates cellular cohesion and adhesion to surfaces. Although important advances were made in the identification of the genetic and extracellular factors required for biofilm formation, the mechanisms leading to biofilm matrix assembly, and the roles of extracellular proteins in these processes are still poorly understood. The symbiont Rhizobium leguminosarum requires the synthesis of the acidic exopolysaccharide and the PrsDE secretion system to develop a mature biofilm. PrsDE is responsible for the secretion of the Rap family of proteins that share one or two Ra/CHDL (cadherin-like-) domains. RapA2 is a calcium-dependent lectin with a cadherin-like β sheet structure that specifically recognizes the exopolysaccharide, either as a capsular polysaccharide (CPS) or in its released form [extracellular polysaccharide (EPS)]. In this study, using gain and loss of function approaches combined with phenotypic and microscopic studies we demonstrated that RapA lectins are involved in biofilm matrix development and cellular cohesion. While the absence of any RapA protein increased the compactness of bacterial aggregates, high levels of RapA1 expanded distances between cells and favored the production of a dense matrix network. Whereas endogenous RapA(s) are predominantly located at one bacterial pole, we found that under overproduction conditions, RapA1 surrounded the cell in a way that was reminiscent of the capsule. Accordingly, polysaccharide analyses showed that the RapA lectins promote CPS formation at the expense of lower EPS production. Besides, polysaccharide analysis suggests that RapA modulates the EPS size profile. Collectively, these results show that the interaction of RapA lectins with the polysaccharide is involved in rhizobial

  13. Mutation of praR in Rhizobium leguminosarum enhances root biofilms, improving nodulation competitiveness by increased expression of attachment proteins.

    Science.gov (United States)

    Frederix, Marijke; Edwards, Anne; Swiderska, Anna; Stanger, Andrew; Karunakaran, Ramakrishnan; Williams, Alan; Abbruscato, Pamela; Sanchez-Contreras, Maria; Poole, Philip S; Downie, J Allan

    2014-08-01

    In Rhizobium leguminosarum bv. viciae, quorum-sensing is regulated by CinR, which induces the cinIS operon. CinI synthesizes an AHL, whereas CinS inactivates PraR, a repressor. Mutation of praR enhanced biofilms in vitro. We developed a light (lux)-dependent assay of rhizobial attachment to roots and demonstrated that mutation of praR increased biofilms on pea roots. The praR mutant out-competed wild-type for infection of pea nodules in mixed inoculations. Analysis of gene expression by microarrays and promoter fusions revealed that PraR represses its own transcription and mutation of praR increased expression of several genes including those encoding secreted proteins (the adhesins RapA2, RapB and RapC, two cadherins and the glycanase PlyB), the polysaccharide regulator RosR, and another protein similar to PraR. PraR bound to the promoters of several of these genes indicating direct repression. Mutations in rapA2, rapB, rapC, plyB, the cadherins or rosR did not affect the enhanced root attachment or nodule competitiveness of the praR mutant. However combinations of mutations in rapA, rapB and rapC abolished the enhanced attachment and nodule competitiveness. We conclude that relief of PraR-mediated repression determines a lifestyle switch allowing the expression of genes that are important for biofilm formation on roots and the subsequent initiation of infection of legume roots.

  14. Polymorphic infection and organogenesis patterns induced by a Rhizobium leguminosarum isolate from Lotus root nodules are determined by the host genotype.

    Science.gov (United States)

    Gossmann, Jasmin A; Markmann, Katharina; Brachmann, Andreas; Rose, Laura E; Parniske, Martin

    2012-10-01

    To sample the natural variation in genes controlling compatibility in the legume-rhizobium symbiosis, we isolated rhizobia from nodules of endemic Lotus species from 21 sites across Europe. The majority of isolates were identified as Mesorhizobium- or Bradyrhizobium-related and formed nitrogen-fixing root nodules on Lotus corniculatus and L. pendunculatus, respectively, thus confirming previously defined cross-inoculation groups. Rhizobium leguminosarum (Rl) strain Norway, isolated from L. corniculatus nodules, displayed an exceptional phenotypic variation on different Lotus genotypes. On L. burttii, Rl Norway formed infected nodules, whereas tumors and elongated infected swellings were induced on L. glaber and L. japonicus ecotype Nepal, respectively. A symbiosis- and Nod-factor-responsive promoter:uidA fusion was strongly and rapidly induced in L. japonicus Gifu, but infection threads or signs of nodule organogenesis were absent. This complex phenotypic pattern was not mimicked by either of three engineered R. leguminosarum bv viciae strains producing different Nod-factor variants. Intriguingly, Rl Norway formed infection threads on Pisum sativum cv Sparkle, but failed to induce organogenesis. Rl Norway thus uncovered variation in symbiotic capabilities among diploid Lotus species and ecotypes that are obscured by optimally adapted M. loti strains. These contrasting infection and organogenesis phenotypes reveal recent diversification of recognition determinants in Lotus.

  15. Bacillus simplex—A Little Known PGPB with Anti-Fungal Activity—Alters Pea Legume Root Architecture and Nodule Morphology When Coinoculated with Rhizobium leguminosarum bv. viciae

    Directory of Open Access Journals (Sweden)

    Ann M. Hirsch

    2013-09-01

    Full Text Available Two strains, 30N-5 and 30VD-1, identified as Bacillus simplex and B. subtilis, were isolated from the rhizospheres of two different plants, a Podocarpus and a palm, respectively, growing in the University of California, Los Angeles (UCLA Mildred E. Mathias Botanical Garden. B. subtilis is a well-known plant-growth promoting bacterial species, but B. simplex is not. B. simplex 30N-5 was initially isolated on a nitrogen-free medium, but no evidence for nitrogen fixation was found. Nevertheless, pea plants inoculated with B. simplex showed a change in root architecture due to the emergence of more lateral roots. When Pisum sativum carrying a DR5::GUSA construct, an indicator for auxin response, was inoculated with either B. simplex 30N-5 or its symbiont Rhizobium leguminosarum bv. viciae 128C53, GUS expression in the roots was increased over the uninoculated controls. Moreover, when pea roots were coinoculated with either B. simplex 30N-5 or B. subtilis 30VD-1 and R. leguminosarum bv. viciae 128C53, the nodules were larger, clustered, and developed more highly branched vascular bundles. Besides producing siderophores and solubilizing phosphate, the two Bacillus spp., especially strain 30VD-1, exhibited anti-fungal activity towards Fusarium. Our data show that combining nodulating, nitrogen-fixing rhizobia with growth-promoting bacteria enhances plant development and strongly supports a coinoculation strategy to improve nitrogen fixation, increase biomass, and establish greater resistance to fungal disease.

  16. Meio semi-seletivo para detectar Xanthomonas axonopodis pv. phaseoli em sementes de feijoeiro e sua erradicação através do tratamento de sementes com o fungicida tolylfluanid A semi-selective medium to detect Xanthomonas axonopodis pv. phaseoli in bean seeds and its eradication through seed treatment with tolylfluanid

    Directory of Open Access Journals (Sweden)

    Lucilene Paula Lopes

    2008-09-01

    Full Text Available Estudou-se a eficiência do meio semi-seletivo desenvolvido para Xanthomonas axonopodis pv. malvacearum (Xam do algodoeiro, com algumas modificações, na detecção de Xanthomonas axonopodis pv. phaseoli (Xap em sementes de feijoeiro, bem como a eficiência do fungicida tolylfluanid na erradicação de Xap através do tratamento de sementes. Foram utilizadas sementes naturalmente infectadas por Xap, procedentes de diferentes municípios do Estado do Paraná. Houve o desenvolvimento de colônias bacterianas ao redor das sementes infectadas sob meio semi-seletivo entre seis e 12 dias de incubação. A freqüência de recuperação de colônias da bactéria em relação ao meio Agar nutriente (AN variou entre 30 a 112%. O crescimento de Xap foi inibido a concentrações entre 54 a 1500 ppm do fungicida tolylfluanid. A bactéria foi recuperada das sementes não tratadas em meio semi-seletivo, mas não das sementes tratadas em solução do fungicida tolylfluanid (1,20g/L água. Em casa de vegetação, das 400 sementes tratadas com tolylfluanid não foi produzida nenhuma planta com sintomas da doença até 30 dias após a semeadura, enquanto que 9,75% das sementes não tratadas apresentaram sintomas de Xap. Em um outro experimento, das 1200 sementes não tratadas um total de 7,08% e 11,67% das plantas mostraram-se com sintomas da doença, enquanto que das sementes tratadas 0,5% e 2,4% apresentaram sintomas, 26 e 46 dias após a semeadura, respectivamente.The efficiency of a semi-selective medium developed for Xanthomonas axonopidis pv. malvacearum (Xam, was verified with some modifications, in detecting the presence of X. axonopodis pv. phaseoli (Xap in bean seed. Seed samples naturally infected with Xap were collected from the State of Paraná. The bacterial growth developed around the infected seed in the semi-selective medium after 12 days after incubation. The recovery frequency of bacterial colonies in relation to nutrient agar varied between 30

  17. Origin of the Outbreak in France of Pseudomonas syringae pv. actinidiae Biovar 3, the Causal Agent of Bacterial Canker of Kiwifruit, Revealed by a Multilocus Variable-Number Tandem-Repeat Analysis

    Science.gov (United States)

    Cunty, A.; Cesbron, S.; Poliakoff, F.; Jacques, M.-A.

    2015-01-01

    The first outbreaks of bacterial canker of kiwifruit caused by Pseudomonas syringae pv. actinidiae biovar 3 were detected in France in 2010. P. syringae pv. actinidiae causes leaf spots, dieback, and canker that sometimes lead to the death of the vine. P. syringae pv. actinidifoliorum, which is pathogenic on kiwi as well, causes only leaf spots. In order to conduct an epidemiological study to track the spread of the epidemics of these two pathogens in France, we developed a multilocus variable-number tandem-repeat (VNTR) analysis (MLVA). MLVA was conducted on 340 strains of P. syringae pv. actinidiae biovar 3 isolated in Chile, China, France, Italy, and New Zealand and on 39 strains of P. syringae pv. actinidifoliorum isolated in Australia, France, and New Zealand. Eleven polymorphic VNTR loci were identified in the genomes of P. syringae pv. actinidiae biovar 3 ICMP 18744 and of P. syringae pv. actinidifoliorum ICMP 18807. MLVA enabled the structuring of P. syringae pv. actinidiae biovar 3 and P. syringae pv. actinidifoliorum strains in 55 and 16 haplotypes, respectively. MLVA and discriminant analysis of principal components revealed that strains isolated in Chile, China, and New Zealand are genetically distinct from P. syringae pv. actinidiae strains isolated in France and in Italy, which appear to be closely related at the genetic level. In contrast, no structuring was observed for P. syringae pv. actinidifoliorum. We developed an MLVA scheme to explore the diversity within P. syringae pv. actinidiae biovar 3 and to trace the dispersal routes of epidemic P. syringae pv. actinidiae biovar 3 in Europe. We suggest using this MLVA scheme to trace the dispersal routes of P. syringae pv. actinidiae at a global level. PMID:26209667

  18. Revised description and classification of atypical isolates of Pasteurella multocida from bovine lungs based on genotypic characterization to include variants previously classified as biovar 2 of Pasteurella canis and Pasteurella avium

    DEFF Research Database (Denmark)

    Christensen, Henrik; Angen, Øystein; Olsen, John E.

    2004-01-01

    -DNA hybridizations between strains of P. multocida, biovar 2 variants of P. avium and P. canis, and P. multocida subsp. septica confirmed similarity at the species level. It is proposed, on the basis of genotypic similarity, that P. multocida be reclassified to include the biovar 2 variants of P. avium and P. canis...... as essential for identification to the species level. A format reclassification of the species is not possible, however, since too few strains have been found to vary in these key characters. Considering the phenotypic diversity of P. multocida, identification will have to depend partly on genotypic methods...

  19. Genotyping of human Brucella melitensis biovar 3 isolated from Shanxi Province in China by MLVA16 and HOOF.

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    Pei Xiao

    Full Text Available BACKGROUND: Brucellosis presents a significant economic burden for China because it causes reproductive failure in host species and chronic health problems in humans. These problems can involve multiple organs. Brucellosis is highly endemic in Shanxi Province China. Molecular typing would be very useful to epidemiological surveillance. The purpose of this study was to assess the diversity of Brucella melitensis strains for epidemiological surveillance. Historical monitoring data suggest that Brucella melitensis biovar 3 is the predominant strain associated with the epidemic of brucellosis in Shanxi Province. METHODS/PRINCIPAL FINDINGS: Multiple-locus variable-number repeat analysis (MLVA-16 and hypervariable octameric oligonucleotide fingerprinting (HOOF-print were used to type a human-hosted Brucella melitensis population (81 strains. Sixty-two MLVA genotypes (discriminatory index: 0.99 were detected, and they had a genetic similarity coefficient ranging from 84.9% to 100%. Eighty strains of the population belonged to the eastern Mediterranean group with panel 1 genotypes 42 (79 strains and 43 (1 strain. A new panel 1 genotype was found in this study. It was named 114 MLVAorsay genotype and it showed similarity to the two isolates from Guangdong in a previous study. Brucella melitensis is distributed throughout Shanxi Province, and like samples from Inner Mongolia, the eastern Mediterranean genotype 42 was the main epidemic strain (97%. The HOOF-printing showed a higher diversity than MLVA-16 with a genetic similarity coefficient ranging from 56.8% to 100%. CONCLUSIONS: According to the MLVA-16 and HOOF-printing results, both methods could be used for the epidemiological surveillance of brucellosis. A new genotype was found in both Shanxi and Guangdong Provinces. In areas with brucellosis, the MLVA-16 scheme is very important for tracing cases back to their origins during outbreak investigations. It may facilitate the expansion and eradication

  20. Prevalence and characterization of multi-drug resistant Salmonella Enterica serovar Gallinarum biovar Pullorum and Gallinarum from chicken

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    Md. Shafiullah Parvej

    2016-01-01

    Full Text Available Aim: Salmonella is an important zoonotic pathogen responsible for animal and human diseases. The aim of the present study was to determine the prevalence and stereotyping of Salmonella isolates isolated from apparently healthy poultry. Furthermore, the clonal relatedness among the isolated Salmonella serovars was assessed. Materials and Methods: A total of 150 cloacal swab samples from apparently healthy chickens were collected, and were subjected for the isolation and identification of associated Salmonella organisms. The isolated colonies were identified and characterized on the basis of morphology, cultural characters, biochemical tests, slide agglutination test, polymerase chain reaction, and pulsed-field gel electrophoresis (PFGE. Antibiotic sensitivity patterns were also investigated using commonly used antibiotics. Results: Of the 150 samples, 11 (7.33% produced characteristics pink colony with black center on XLD agar medium, and all were culturally and biochemically confirmed to be Salmonella. All possessed serovar-specific gene SpeF and reacted uniformly with group D antisera, suggesting that all of the isolates were Salmonella Enterica serovar Gallinarum, biovar Pullorum and/or Gallinarum. Antimicrobial susceptibility testing revealed that 54.54% of the isolated Salmonella Enterica serovars were highly sensitive to ciprofloxacin, whereas the 81.81% isolates were resistant to amoxycillin, doxycycline, kanamycin, gentamycin, and tetracycline. Pulsed-field gel electrophoresis of the XbaI-digested genomic DNA exhibited identical banding patterns, suggesting that the multidrug resistant Salmonella Enterica serovars occurring in commercial layers are highly clonal in Bangladesh. Conclusion: The present study was conducted to find out the prevalence of poultry Salmonella in layer chicken and to find out the clonal relationship among them. The data in this study suggest the prevalence of Salmonella Enterica, which is multidrug resistant and

  1. SEÑALES PRODUCIDAS POR Rhizobium leguminosarum EN LA INTERACCIÓN CON FRIJOL COMÚN (Phaseolus vulgaris L.

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    María C. Nápoles García

    2016-01-01

    Full Text Available La interacción Rhizobium-leguminosas depende de un complejo intercambio de señales, que se mantiene durante todo el proceso simbiótico y de las que solamente una combinación correcta permitirá una simbiosis eficiente. Estas plantas secretan flavonoides, reconocidos por bacterias compatibles y que inducen sus genes nod. Estos codifican las proteínas que sintetizan y exportan lipoquitooligosacáridos conocidos como factores Nod. Los factores Nod activan los procesos de infección e inician la división celular en la raíz, hasta la formación del nódulo y participan también en la fijación biológica del nitrógeno. Existen evidencias de que el uso de inductores de los genes nod incrementa la nodulación en algunas leguminosas. El objetivo de este trabajo fue estudiar la producción de algunas moléculas señales, inducidas por la isoflavona genisteína en una cepa de R. leguminosarum y evaluar el impacto de esa inducción en el efecto del inóculo sobre plantas de frijol común. La fracción lipídica en los inóculos fue extraída con n-butanol y analizada por cromatografía de capa fina, cromatografía líquida de alta resolución y cromatografía gaseosa acoplada a un espectrómetro de masas. En los inóculos inducidos con genisteína se detectó una cantidad superior de lipooligosacáridos (factores de nodulación y de ácidos grasos de alto peso molecular, con diferencias significativas respecto a los controles sin inducir. En relación con ese enriquecimiento en moléculas señales, los inóculos inducidos con genisteína, mostraron un efecto positivo en las plantas de frijol de la variedad Cubacueto 25-9, con mayor número de nódulos y contenido de clorofila que las plantas no inoculadas (control.

  2. [Secretion of Phenolic Compounds into Root Exudates of Pea Seedlings upon Inoculation with Rhizobium leguminosarum bv. viceae or Pseudomonas siringae pv. Pisi].

    Science.gov (United States)

    Makarova, L E; Dudareva, L V; Petrova, I G; Vasil'eva, G G

    2016-01-01

    The content of apigenin, naringenin, pisatin, dibutyl-ortho-phthalate, and N-phenyl-2-naphthyl-amine were assayed in root exudates of pea (Pisum sativum L.) seedlings one day after their inoculation with Rhizobium leguminosarum, bv. viceae or Pseudomonas siringae pv. pisi, which represent, respectively, mutualistic and antagonistic strategies of interaction with a host plant. After inoculation with either bacteria, the concentrations of apigenin and pisatin in the root exudates were equal, whereas the concentrations of naringenin and N-phenyl-2-naphthylamine were different and those of dibutyl-o-phthalate were unchanged. A certain role is suggested for the phenolic compounds in an accomplishment of symbiotic relations of bacteria with a host plant.

  3. Otimização da técnica de PCR para a detecção de Xanthomonas axonopodis pv. phaseoli em sementes de feijão Optimization of PCR technique for detection of Xanthomonas axonopodis pv. phaseoli in bean seeds

    Directory of Open Access Journals (Sweden)

    Franklin Cordeiro Silva

    2013-03-01

    Full Text Available O crestamento bacteriano comum, causado por Xanthomonas axonopodis pv. phaseoli (Xap, é a principal bacteriose do feijoeiro no Brasil, sendo transmitida principalmente por sementes. O presente trabalho teve como objetivo aperfeiçoar uma técnica, por meio de diferentes métodos de preparação do extrato, para a detecção de Xap, bem como sua detecção simultânea com Curtobacterium flaccumfaciens pv. flaccumfaciens (Cff nos extratos de sementes de feijão,via PCR. A partir de amostras de sementes de feijão inoculadas artificialmente com Xap e lotes comerciais, foram avaliados: extrato bruto obtido diretamente das sementes, extrato concentrado por filtração em membrana de 0,22µM de diâmetro, extrato concentrado por centrifugação e extrato plaqueado em meio semi-seletivo XCP1 com e sem antibióticos (BIO-PCR. Avaliou-se a presença simultânea de Xap e Cff em 10 lotes comerciais de sementes de feijão através da reação multiplex, utilizandos-se os primers X4c, X4e, CffFOR2 e CffREV4. A partir do extrato bruto, do extrato concentrado por centrifugação e por filtragem em membrana Millipore® não foi possível a detecção de Xap nas sementes de feijão artificialmente contaminadas nem nos 47 lotes comerciais de sementes/ grãos de feijão. A técnica de BIO-PCR permitiu a detecção de Xap a partir de extratos de sementes de feijão artificialmente contaminadas e em 18 dos 47 lotes comerciais. A técnica de detecção simultânea de Xap e Cff no mesmo gel é viável, por amplificar fragmentos de DNA típicos de cada fitobactéria. O uso do meio de cultura XCP1 sem adição de antibióticos permitiu detectar Xap com período de incubação menor em um dia em comparação à detecção utilizando-se o meio de cultura com antibióticosCommon bacterial blight, caused by Xanthomonas axonopodis pv. phaseoli (Xap, is the major bacteriosis affecting bean plants in Brazil and is mainly transmitted by seeds. This study aimed to improve a

  4. INFLUÊNCIA DA DENSIDADE DE INÓCULO DE Fusarium solani f.sp. phaseoli NA SEVERIDADE DA PODRIDÃO RADICULAR SECA DO FEIJOEIRO EFFECT OF Fusarium solani f.sp. phaseoli INOCULUM DENSITY ON DRY ROOT ROT SEVERITY IN THE COMMON BEAN

    Directory of Open Access Journals (Sweden)

    Gesimária Ribeiro Costa

    2007-09-01

    Full Text Available

    Foram testadas quatro densidades de inóculo de Fusarium solani, em gramas por litro de solo (1,0; 2,0; 4,0 e 8,0 e um tratamento testemunha, em solo tipo Latossolo Vermelho-Escuro, cultivado e não cultivado, com o objetivo de determinar a densidade mínima de inóculo no solo necessária para a ocorrência de podridão radicular seca do feijoeiro. Como variáveis respostas foram avaliadas: número de microorganismos totais do solo, número de propágulos de F. solani, atividade microbiológica total do solo e severidade da doença em plântulas. Os resultados indicaram que a densidade de inóculo do fungo variou com o tipo de solo. Para um solo não cultivado a densidade necessária para causar a doença esteve acima de 5.127 propágulos por grama de solo, enquanto para o solo cultivado a densidade de inóculo para causar doença foi de 3.701 propágulos por grama de solo. Os índices de doença em plântulas cultivadas sob o solo cultivado foram duas vezes superiores ao índice de doença de plântulas sob o solo não cultivado. A atividade microbiológica total nos solos, determinada pela desidrogenase de fluorescina diacetato, não se correlacionou com a população dos microorganismos, indicando que a simples presença desses não implica em que estejam ativos.

    PALAVRAS-CHAVE: Solo supressivo; solo conducivo; Phaseolus vulgaris.

    Four densities of Fusarium solani inoculum (1, 2, 4 and 8 g/L of soil were tested for determining the minimum inoculum density for the occurrence of bean dry root rot, in two soil types. The response variables evaluated were the total number of microorganisms in the soil, the number of F. solani f. sp. phaseoli propagules, total soil microbial activity and seedling disease severity

  5. RESPUESTA A BACTERIOSIS COMÚN (Xanthomonas axonopodis p.v phaseoli EN LOS CULTIVARES COMERCIALES DE FRIJOL COMÚN DE CUBA, EN CONDICIONES DE CAMPO. AFECTACIÓN DE LOS RENDIMIENTOS POR EFECTO DE LA INOCULACIÓN

    Directory of Open Access Journals (Sweden)

    Odile Rodríguez Miranda

    2015-01-01

    Full Text Available En el germoplasma de frijol común (Phaseolus vulgaris L., en Cuba, es posible identificar cultivares con niveles de resistencia ante un aislamiento patogénico de Xanthomonas axonopodis pv. phaseoli, a fin de disminuir las pérdidas y aumentar el rendimiento promedio del cultivo en campos infectados con este patógeno. Los objetivos de este trabajo estuvieron dirigidos a evaluar, en genotipos de frijol común respuestas contrastantes frente a la incidencia natural e inoculación del aislamiento patogénico Xap527 (Xanthomonas axonopodis; identificar los cultivares comerciales con mejor comportamiento en follaje y vainas y con menores pérdidas de rendimiento en campos infectados por este patógeno. Los resultados permitieron seleccionar los genotipos de frijol, con buen comportamiento frente al aislamiento de Xap estudiado y se determinó la disminución del rendimiento en los cultivares de frijol por su reacción de susceptibilidad frente a Bacteriosis común, con la inoculación del aislamiento Xap 527, de Cuba

  6. Possession, Use, and Transfer of Select Agents and Toxins-- Addition of Bacillus Cereus Biovar Anthracis to the HHS List of Select Agents and Toxins. Interim final rule and request for comments.

    Science.gov (United States)

    2016-09-14

    The Centers for Disease Control and Prevention (CDC) in the Department of Health and Human Services (HHS) is adding Bacillus cereus Biovar anthracis to the list of HHS select agents and toxins as a Tier 1 select agent. We are taking this action to regulate this agent that is similar to B. anthracis to prevent its misuse, which could cause a biological threat to public health and/or national security.

  7. Complete genome sequence of Rhizobium leguminosarum bv trifolii strain WSM2304, an effective microsymbiont of the South American clover Trifolium polymorphum

    Energy Technology Data Exchange (ETDEWEB)

    Reeve, Wayne [Murdoch University, Perth, Australia; O' Hara, Graham [Murdoch University, Perth, Australia; Chain, Patrick S. G. [Lawrence Livermore National Laboratory (LLNL); Ardley, Julie [Murdoch University, Perth, Australia; Brau, Lambert [Murdoch University, Perth, Australia; Nandesena, Kemanthi [Murdoch University, Perth, Australia; Tiwari, Ravi [Murdoch University, Perth, Australia; Malfatti, Stephanie [Lawrence Livermore National Laboratory (LLNL); Kiss, Hajnalka [Los Alamos National Laboratory (LANL); Lapidus, Alla L. [U.S. Department of Energy, Joint Genome Institute; Copeland, A [U.S. Department of Energy, Joint Genome Institute; Nolan, Matt [U.S. Department of Energy, Joint Genome Institute; Land, Miriam L [ORNL; Ivanova, N [U.S. Department of Energy, Joint Genome Institute; Mavromatis, K [U.S. Department of Energy, Joint Genome Institute; Markowitz, Victor [U.S. Department of Energy, Joint Genome Institute; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Melino, Vanessa [Murdoch University, Perth, Australia; Denton, Matthew [Department of Primary Industries, Victoria, Australia; Yates, Ron [Murdoch University, Perth, Australia; Howieson, John [Murdoch University, Perth, Australia

    2010-01-01

    Rhizobium leguminosarum bv trifolii is the effective nitrogen fixing microsymbiont of a diverse range of annual and perennial Trifolium (clover) species. Strain WSM2304 is an aerobic, motile, non-spore forming, Gram-negative rod, isolated from Trifolium polymorphum in Uruguay in 1998. This microsymbiont predominated in the perennial grasslands of Glencoe Research Station, in Uruguay, to competitively nodulate its host, and fix atmospheric nitrogen. Here we describe the basic features of WSM2304, together with the complete genome sequence, and annotation. This is the first completed genome sequence for a nitrogen fixing microsymbiont of a clover species from the American center of origin. We reveal that its genome size is 6,872,702 bp encoding 6,643 protein-coding genes and 62 RNA only encoding genes. This multipartite genome was found to contain 5 distinct replicons; a chromosome of size 4,537,948 bp and four circular plasmids of size 1,266,105 bp, 501,946 bp, 308,747 bp and 257,956 bp.

  8. Rhizobium leguminosarum bv. viciae 3841 Adapts to 2,4-Dichlorophenoxyacetic Acid with "Auxin-Like" Morphological Changes, Cell Envelope Remodeling and Upregulation of Central Metabolic Pathways.

    Directory of Open Access Journals (Sweden)

    Supriya V Bhat

    Full Text Available There is a growing need to characterize the effects of environmental stressors at the molecular level on model organisms with the ever increasing number and variety of anthropogenic chemical pollutants. The herbicide 2,4-dichlorophenoxyacetic acid (2,4-D, as one of the most widely applied pesticides in the world, is one such example. This herbicide is known to have non-targeted undesirable effects on humans, animals and soil microbes, but specific molecular targets at sublethal levels are unknown. In this study, we have used Rhizobium leguminosarum bv. viciae 3841 (Rlv as a nitrogen fixing, beneficial model soil organism to characterize the effects of 2,4-D. Using metabolomics and advanced microscopy we determined specific target pathways in the Rlv metabolic network and consequent changes to its phenotype, surface ultrastructure, and physical properties during sublethal 2,4-D exposure. Auxin and 2,4-D, its structural analogue, showed common morphological changes in vitro which were similar to bacteroids isolated from plant nodules, implying that these changes are related to bacteroid differentiation required for nitrogen fixation. Rlv showed remarkable adaptation capabilities in response to the herbicide, with changes to integral pathways of cellular metabolism and the potential to assimilate 2,4-D with consequent changes to its physical and structural properties. This study identifies biomarkers of 2,4-D in Rlv and offers valuable insights into the mode-of-action of 2,4-D in soil bacteria.

  9. Brucella melitensis Biovar 1 and Brucella abortus S19 Vaccine Strain Infections in Milkers Working at Cattle Farms in the Khartoum Area, Sudan.

    Directory of Open Access Journals (Sweden)

    Amira E F Osman

    Full Text Available Human brucellosis is a preventable zoonoses that may become persistent, causing, if left untreated, severe localized disease. Occupational exposure to infected animals or animal products and consumption of fresh contaminated dairy are main risk factors.One hundred farmworkers employed at two cattle farms one in Khartoum North and one in Omdurman were screened for the presence of specific antibodies and seropositive workers were invited to donate a blood sample for blood culture. Molecular typing was used to characterize Brucella isolates.Ten percent of farmworkers tested seropositive and while Brucella melitensis biovar 1 was isolated from the blood of three individuals, an isolate identical to the B. abortus S19 vaccine strain was isolated from a fourth person. All four bacteremic individuals were employed as milkers and did not have obvious disease.The isolation of the highly infectious pathogen B. melitensis from seropositive workers is consistent with the notion that the pathogen may persist in the blood without causing overt disease. While vaccination with strain S19 is essential for the control of bovine brucellosis the vaccine strain may be transmitted to the human population and protective measures remain important to prevent exposure also in view of the presence of B. melitensis. To create awareness for this potentially severe disease more information on the prevalence of the pathogen in different risk groups and in livestock in the Sudan is needed.

  10. Emergence and molecular characterisation of non-toxigenic tox gene-bearing Corynebacterium diphtheriae biovar mitis in the United Kingdom, 2003-2012.

    Science.gov (United States)

    Zakikhany, K; Neal, S; Efstratiou, A

    2014-06-05

    Non-toxigenic Corynebacterium diphtheriae have become increasingly recognised as emerging pathogens across Europe causing severe invasive disease. A subset of non-toxigenic C. diphtheriae are ‘non-toxigenic tox gene-bearing’ (NTTB) strains; these strains are genotypically toxpositive, but do not express the protein. The circulation of NTTB strains was first observed during the 1990s upsurge of diphtheria in Eastern Europe but has not been reported in other European countries. Circulation of NTTB strains could be considered an increased risk for diphtheria and other related diseases, given their possible role as a tox gene reservoir with the theoretical risk of re-emerging toxin expression. Here we report the characterisation of 108 non-toxigenic C. diphtheriae biovar mitis isolates submitted to the World Health Organization (WHO) Global Reference Centre for Diphtheria at Public Health England, London, between 2003 and 2012, in order to determine the presence of NTTB strains. Using molecular methods, five NTTB isolates were identified; four human isolates (MLST type 212) and one isolate from a companion cat (MLST type 40). The emergence of these strains could indicate continuation of the circulation of potentially toxigenic strains and appropriate laboratory diagnostic methods should be used for detection. Given the complacency that currently exists in Europe awareness with regards to diphtheria diagnostics must be enhanced.

  11. Nickel availability to pea (Pisum sativum L.) plants limits hydrogenase activity of Rhizobium leguminosarum bv. viciae bacteroids by affecting the processing of the hydrogenase structural subunits.

    Science.gov (United States)

    Brito, B; Palacios, J M; Hidalgo, E; Imperial, J; Ruiz-Argüeso, T

    1994-01-01

    Rhizobium leguminosarum bv. viciae UPM791 induces the synthesis of an [NiFe] hydrogenase in pea (Pisum sativum L.) bacteroids which oxidizes the H2 generated by the nitrogenase complex inside the root nodules. The synthesis of this hydrogenase requires the genes for the small and large hydrogenase subunits (hupS and hupL, respectively) and 15 accessory genes clustered in a complex locus in the symbiotic plasmid. We show here that the bacteroid hydrogenase activity is limited by the availability of nickel to pea plants. Addition of Ni2+ to plant nutrient solutions (up to 10 mg/liter) resulted in sharp increases (up to 15-fold) in hydrogenase activity. This effect was not detected when other divalent cations (Zn2+, Co2+, Fe2+, and Mn2+) were added at the same concentrations. Determinations of the steady-state levels of hupSL-specific mRNA indicated that this increase in hydrogenase activity was not due to stimulation of transcription of structural genes. Immunoblot analysis with antibodies raised against the large and small subunits of the hydrogenase enzyme demonstrated that in the low-nickel situation, both subunits are mainly present in slow-migrating, unprocessed forms. Supplementation of the plant nutrient solution with increasing nickel concentrations caused the conversion of the slow-migrating forms of both subunits into fast-moving, mature forms. This nickel-dependent maturation process of the hydrogenase subunits is mediated by accessory gene products, since bacteroids from H2 uptake-deficient mutants carrying Tn5 insertions in hupG and hupK and in hypB and hypE accumulated the immature forms of both hydrogenase subunits even in the presence of high nickel levels. Images PMID:8071205

  12. The function of three indigenous plasmids in Mesorhizobium huakuii 2020 and its symbiotic inter-action with Sym pJB5JI of Rhizobium leguminosarum

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A Mesorhizobium huakuii strain 2020, isolated from a rice-growing field in southern China, contains three indigenous plasmids named p2020a, p2020b and p2020c, respectively. The plasmids were deleted via Tn5-sacB insertion, and two cured derivatives were obtained. Interestingly, the mutant 2020D29 curing of p2020c could significantly enhance the capacity of symbiotic nitrogen fixation. But the mutant 2020D8 curing of p2020b lost the ability to nodulate Astragalus sinicus. Furthermore, the third plasmid p2020a could be hardly eliminated, suggesting that some house-keeping genes necessary for strain growth located on this plasmid. Then the Sym plasmid pJB5JI of R. leguminosarum bv. viciae was transferred into 2020 and its cured derivatives. The pot plant test showed that the ability of competition and symbiotic nitrogen fixation of transconjugant 2020-137 (pJB5JI) was increased evidently in con-trast to 2020. pJB5JI could not restore the ability of 2020D8 to nodulate Astragalus sinicus. 2020D8-8 (pJB5JI) could form ineffective nodules on peas, which implied that the symbiotic plasmid pJB5JI could express its function at the chromosomal background of Mesorhizobium huakuii 2020. The plas-mid stability was checked in transconjugants under free-living and during symbiosis. The results indi-cated that pJB5JI failed to be detected in some nodule isolates. That Km resistance gene could be am-plified from all transconjugants and nodule isolates suggested that pJB5JI was fully or partially inte-grated into the chromosome of recipients.

  13. Unexpectedly Diverse Mesorhizobium Strains and Rhizobium leguminosarum Nodulate Native Legume Genera of New Zealand, while Introduced Legume Weeds Are Nodulated by Bradyrhizobium Species

    Science.gov (United States)

    Weir, Bevan S.; Turner, Susan J.; Silvester, Warwick B.; Park, Duck-Chul; Young, John M.

    2004-01-01

    The New Zealand native legume flora are represented by four genera, Sophora, Carmichaelia, Clianthus, and Montigena. The adventive flora of New Zealand contains several legume species introduced in the 19th century and now established as serious invasive weeds. Until now, nothing has been reported on the identification of the associated rhizobia of native or introduced legumes in New Zealand. The success of the introduced species may be due, at least in part, to the nature of their rhizobial symbioses. This study set out to address this issue by identifying rhizobial strains isolated from species of the four native legume genera and from the introduced weeds: Acacia spp. (wattles), Cytisus scoparius (broom), and Ulex europaeus (gorse). The identities of the isolates and their relationship to known rhizobia were established by comparative analysis of 16S ribosomal DNA, atpD, glnII, and recA gene sequences. Maximum-likelihood analysis of the resultant data partitioned the bacteria into three genera. Most isolates from native legumes aligned with the genus Mesorhizobium, either as members of named species or as putative novel species. The widespread distribution of strains from individual native legume genera across Mesorhizobium spp. contrasts with previous reports implying that bacterial species are specific to limited numbers of legume genera. In addition, four isolates were identified as Rhizobium leguminosarum. In contrast, all sequences from isolates from introduced weeds aligned with Bradyrhizobium species but formed clusters distinct from existing named species. These results show that native legume genera and these introduced legume genera do not have the same rhizobial populations. PMID:15466541

  14. Variability of isolated colonies in bean nodulating Rhizobium strains before and after exposure to high temperature

    Directory of Open Access Journals (Sweden)

    Raposeiras Rui

    2002-01-01

    Full Text Available Irregular response to bean plants to Rhizobium inoculation has been attributed to among other factors, low competitive ability, low N2 fixation efficiency and genetic instability of the symbiont. This genetic instability caused by high rates of genomic rearrangements and/or plasmid deletions can be accentuated by high temperatures. This fact may limit the utilization of these strains as inoculants, especially in tropical soils. In this study, the variability of isolated colonies derived from effective R. leguminosarum bv. phaseoli (SLP1.3 and BR 10.026 and R tropici (SLA2.2 and BR322 strains was evaluated before and after exposure to high temperatures (four consecutive thermal shocks at 45masculineC. This evaluation involved plant dry matter analysis of inoculated plants and genotypic (plasmid profile and genomic patterns via RAPD analysis of the Rhizobium strains. The results evidenced that high temperature improve the natural performance variability especially between isolated colonies from R. leguminosarum bv. phaseoli strains. The plasmid profile of isolated colonies from R. tropici strains were identical regardless of temperature treatment whereas isolated colonies from R. leguminosarum bv. phaseoli alterations were detected especially after the thermal treatment. The genomic patterns generated by AP-PCR showed more alterations and genetic variation in isolated colonies from R. leguminosarum bv. phaseoli strains indicating that R. tropici strains are more stable and lower affected by high temperature.

  15. Licheniocin 50.2 and Bacteriocins from Lactococcus lactis subsp. lactis biovar. diacetylactis BGBU1-4 Inhibit Biofilms of Coagulase Negative Staphylococci and Listeria monocytogenes Clinical Isolates

    Science.gov (United States)

    Draganic, Veselin; Lozo, Jelena; Beric, Tanja; Kojic, Milan; Arsic, Biljana; Garalejic, Eliana; Djukic, Slobodanka; Stankovic, Slavisa

    2016-01-01

    Background Coagulase negative staphylococci (CoNS) and Listeria monocytogenes have important roles in pathogenesis of various genital tract infections and fatal foetomaternal infections, respectively. The aim of our study was to investigate the inhibitory effects of two novel bacteriocins on biofilms of CoNS and L. monocytogenes genital isolates. Methods The effects of licheniocin 50.2 from Bacillus licheniformis VPS50.2 and crude extract of bacteriocins produced by Lactococcus lactis subsp. lactis biovar. diacetylactis BGBU1-4 (BGBU1-4 crude extract) were evaluated on biofilm formation and formed biofilms of eight CoNS (four S. epidermidis, two S. hominis, one S. lugdunensis and one S. haemolyticus) and 12 L. monocytogenes genital isolates. Results Licheniocin 50.2 and BGBU1-4 crude extract inhibited the growth of both CoNS and L. monocytogenes isolates, with MIC values in the range between 200–400 AU/ml for licheniocin 50.2 and 400–3200 AU/ml for BGBU1-4 crude extract. Subinhibitory concentrations (1/2 × and 1/4 × MIC) of licheniocin 50.2 inhibited biofilm formation by all CoNS isolates (p bacteriocins in concentrations of 100 AU/mL and 200 AU/mL reduced the amount of 24 h old CoNS and L. monocytogenes biofilms (p bacteriocins have potential to be used for genital application, to prevent biofilm formation and/or to eradicate formed biofilms, and consequently reduce genital and neonatal infections by CoNS and L. monocytogenes. PMID:27930711

  16. Reporte histórico: Primer Aislamiento de Vibrio cholera serogrupo O1 biovar El Tor serovar Inaba durante la epidemia de cólera en el Perú ‑ 1991 Historical report: first isolation of Vibrio cholera serogroup O1 biovar El Tor serovar Inaba during the cholerae epidemic in Perú ‑ 1991

    Directory of Open Access Journals (Sweden)

    Nora Bravo Cruz

    2011-03-01

    Full Text Available Hace 20 años apareció una enfermedad diarreica nueva en el Perú y el Laboratorio de Referencia de Enteropatógenos del Instituto Nacional de Salud, cumplió una labor destacada en el aislamiento e identificación rápida y oportuna del Vibrio cholerae. La enfermedad del cólera no se había presentado anteriormente, pero en la última semana de enero de 1991 se detectó un brote epidémico de diarrea aguda con deshidratación intensa y algunos casos de fallecidos. La epidemia afectó, al comienzo, varias localidades del litoral peruano. Equipos de trabajo de la Oficina General de Epidemiología y de los laboratorios del Instituto Nacional de Salud obtuvieron muestras fecales de pacientes con diarrea aguda procedentes de las ciudades de Chancay, Chimbote, Piura y algunos hospitales de Lima. Las muestras colectadas en el medio de transporte de Cary y Blair fueron procesadas en el Laboratorio Nacional de Referencia de Enteropatógenos (LANARE del Instituto Nacional de Salud. De todas las muestras se aisló e identificó Vibrio cholerae serogrupo O1 biovar El Tor serovar Inaba que mostró ser sensible a la tetraciclina y a otros antibióticos. Esta investigación confirmó el primer brote epidémico de cólera en el Perú.20 years ago, a new diarrheal disease was introduced in Peru and the Enteropathogens Reference Laboratory of the Instituto Nacional de Salud had an outstanding role in the isolation and rapid and timely identification of Vibrio cholerae. Cholera had not been seen before, but during the last week of January 1991 an outbreak of acute diarrhea was detected, presenting intense dehydration and some deaths. The epidemic affected, in the beginning, many locations of the peruvian coast. Some working teams of the General Office of Epidemiology and of the Instituto Nacional de Salud obtained fecal samples from patients with acute diarrhea coming from the cities of Chancay, Chimbote, Piura and some hospitals in Lima. The collected samples

  17. Crystallization and X-ray diffraction analysis of an l-arabinonate dehydratase from Rhizobium leguminosarum bv. trifolii and a d-xylonate dehydratase from Caulobacter crescentus

    Science.gov (United States)

    Rahman, Mohammad Mubinur; Andberg, Martina; Koivula, Anu; Rouvinen, Juha; Hakulinen, Nina

    2016-01-01

    l-Arabinonate dehydratase (EC 4.2.1.25) and d-xylonate dehydratase (EC 4.2.1.82) are two enzymes that are involved in a nonphosphorylative oxidation pathway of pentose sugars. l-Arabinonate dehydratase converts l-arabinonate into 2-dehydro-3-deoxy-l-arabinonate, and d-xylonate dehydratase catalyzes the dehydration of d-xylonate to 2-dehydro-3-deoxy-d-xylonate. l-Arabinonate and d-xylonate dehydratases belong to the IlvD/EDD family, together with 6-phosphogluconate dehydratases and dihydroxyacid dehydratases. No crystal structure of any l-arabinonate or d-xylonate dehydratase is available in the PDB. In this study, recombinant l-arabinonate dehydratase from Rhizobium leguminosarum bv. trifolii (RlArDHT) and d-xylonate dehydratase from Caulobacter crescentus (CcXyDHT) were heterologously expressed in Escherichia coli and purified by the use of affinity chromatography followed by gel-filtration chromatography. The purified proteins were crystallized using the hanging-drop vapour-diffusion method at 293 K. Crystals of RlArDHT that diffracted to 2.40 Å resolution were obtained using sodium formate as a precipitating agent. They belonged to space group P21, with unit-cell parameters a = 106.07, b = 208.61, c = 147.09 Å, β = 90.43°. Eight RlArDHT molecules (two tetramers) in the asymmetric unit give a V M value of 3.2 Å3 Da−1 and a solvent content of 62%. Crystals of CcXyDHT that diffracted to 2.66 Å resolution were obtained using sodium formate and polyethylene glycol 3350. They belonged to space group C2, with unit-cell parameters a = 270.42, b = 236.13, c = 65.17 Å, β = 97.38°. Four CcXyDHT molecules (a tetramer) in the asymmetric unit give a V M value of 4.0 Å3 Da−1 and a solvent content of 69%. PMID:27487924

  18. Crystallization and X-ray diffraction analysis of an l-arabinonate dehydratase from Rhizobium leguminosarum bv. trifolii and a d-xylonate dehydratase from Caulobacter crescentus

    Energy Technology Data Exchange (ETDEWEB)

    Rahman, Mohammad Mubinur [University of Eastern Finland, Joensuu Campus, PO Box 111, FIN-80101 Joensuu (Finland); Andberg, Martina; Koivula, Anu [VTT Technical Research Centre of Finland Ltd, PO Box 1000, FIN-02044 VTT Espoo (Finland); Rouvinen, Juha; Hakulinen, Nina, E-mail: nina.hakulinen@uef.fi [University of Eastern Finland, Joensuu Campus, PO Box 111, FIN-80101 Joensuu (Finland)

    2016-07-13

    l-Arabinonate dehydratase and d-xylonate dehydratase from the IlvD/EDD family were crystallized by the vapour-diffusion method. Diffraction data sets were collected to resolutions of 2.40 and 2.66 Å from crystals of l-arabinonate dehydratase and d-xylonate dehydratase, respectively. l-Arabinonate dehydratase (EC 4.2.1.25) and d-xylonate dehydratase (EC 4.2.1.82) are two enzymes that are involved in a nonphosphorylative oxidation pathway of pentose sugars. l-Arabinonate dehydratase converts l-arabinonate into 2-dehydro-3-deoxy-l-arabinonate, and d-xylonate dehydratase catalyzes the dehydration of d-xylonate to 2-dehydro-3-deoxy-d-xylonate. l-Arabinonate and d-xylonate dehydratases belong to the IlvD/EDD family, together with 6-phosphogluconate dehydratases and dihydroxyacid dehydratases. No crystal structure of any l-arabinonate or d-xylonate dehydratase is available in the PDB. In this study, recombinant l-arabinonate dehydratase from Rhizobium leguminosarum bv. trifolii (RlArDHT) and d-xylonate dehydratase from Caulobacter crescentus (CcXyDHT) were heterologously expressed in Escherichia coli and purified by the use of affinity chromatography followed by gel-filtration chromatography. The purified proteins were crystallized using the hanging-drop vapour-diffusion method at 293 K. Crystals of RlArDHT that diffracted to 2.40 Å resolution were obtained using sodium formate as a precipitating agent. They belonged to space group P2{sub 1}, with unit-cell parameters a = 106.07, b = 208.61, c = 147.09 Å, β = 90.43°. Eight RlArDHT molecules (two tetramers) in the asymmetric unit give a V{sub M} value of 3.2 Å{sup 3} Da{sup −1} and a solvent content of 62%. Crystals of CcXyDHT that diffracted to 2.66 Å resolution were obtained using sodium formate and polyethylene glycol 3350. They belonged to space group C2, with unit-cell parameters a = 270.42, b = 236.13, c = 65.17 Å, β = 97.38°. Four CcXyDHT molecules (a tetramer) in the asymmetric unit give a V{sub M

  19. Crystallization and X-ray diffraction analysis of an L-arabinonate dehydratase from Rhizobium leguminosarum bv. trifolii and a D-xylonate dehydratase from Caulobacter crescentus.

    Science.gov (United States)

    Rahman, Mohammad Mubinur; Andberg, Martina; Koivula, Anu; Rouvinen, Juha; Hakulinen, Nina

    2016-08-01

    L-Arabinonate dehydratase (EC 4.2.1.25) and D-xylonate dehydratase (EC 4.2.1.82) are two enzymes that are involved in a nonphosphorylative oxidation pathway of pentose sugars. L-Arabinonate dehydratase converts L-arabinonate into 2-dehydro-3-deoxy-L-arabinonate, and D-xylonate dehydratase catalyzes the dehydration of D-xylonate to 2-dehydro-3-deoxy-D-xylonate. L-Arabinonate and D-xylonate dehydratases belong to the IlvD/EDD family, together with 6-phosphogluconate dehydratases and dihydroxyacid dehydratases. No crystal structure of any L-arabinonate or D-xylonate dehydratase is available in the PDB. In this study, recombinant L-arabinonate dehydratase from Rhizobium leguminosarum bv. trifolii (RlArDHT) and D-xylonate dehydratase from Caulobacter crescentus (CcXyDHT) were heterologously expressed in Escherichia coli and purified by the use of affinity chromatography followed by gel-filtration chromatography. The purified proteins were crystallized using the hanging-drop vapour-diffusion method at 293 K. Crystals of RlArDHT that diffracted to 2.40 Å resolution were obtained using sodium formate as a precipitating agent. They belonged to space group P21, with unit-cell parameters a = 106.07, b = 208.61, c = 147.09 Å, β = 90.43°. Eight RlArDHT molecules (two tetramers) in the asymmetric unit give a VM value of 3.2 Å(3) Da(-1) and a solvent content of 62%. Crystals of CcXyDHT that diffracted to 2.66 Å resolution were obtained using sodium formate and polyethylene glycol 3350. They belonged to space group C2, with unit-cell parameters a = 270.42, b = 236.13, c = 65.17 Å, β = 97.38°. Four CcXyDHT molecules (a tetramer) in the asymmetric unit give a VM value of 4.0 Å(3) Da(-1) and a solvent content of 69%.

  20. Construction and Function of Permease Gene Mutant in Rhizobium leguminosarum%豌豆根瘤菌透性酶基因突变体的构建及其功能研究

    Institute of Scientific and Technical Information of China (English)

    周艳琳; 曾小波; 田梦洋; 殷杰; 程国军

    2015-01-01

    This study investigated the role of the permease gene rl1568 in Rhizobium species strain 3841,rl1568 knockout R.leguminosarum strain was constructed by homologous recombination.Under the free-living conditions,the rl1568 mutant exhib-ited no generation time extension.However,cells of the rl1568 mutant strain were sensitive and deficient in consumption of low concentrations of peroxide.The qRT-PCR results showed that rl1568 was expressed independently of exogenous H2O2.With regard to symbiotic capacities with Pisum sativum,there was no different between the rl1568 mutant and the wild type in root nodule nitogenase activity.%为研究豌豆根瘤菌(Rhizobium leguminosarum)3841透性酶基因rl1568的作用,通过同源重组构建了豌豆根瘤菌透性酶基因rl1568突变体.结果表明,rl1568基因突变不影响菌株在自生培养条件下生长,但该基因突变株对低浓度的氧化物十分敏感且生长较差. 荧光定量RT-PCR结果表明,H2O2不能诱导rl1568基因表达. 植物盆栽试验发现rl1568基因突变对根瘤菌共生固氮能力无影响.

  1. 布鲁氏菌种及种内部分生物型快速PCR鉴定方法的建立及应用研究%Development and application of one-step polymerase chain reaction(PCR) for rapid identification of Brucella species and some biovars

    Institute of Scientific and Technical Information of China (English)

    李振军; 侯雪新; 孙渭歌; 贾雪; 田国忠

    2013-01-01

    目的 建立一步法PCR快速鉴定布鲁氏菌种及种内部分生物型.方法 设计6对引物,建立一步法PCR反应,将布鲁氏菌6个种和种内某些生物型进行鉴定,应用该方法检测了27株布鲁氏菌参考菌株和239株临床分离的布鲁氏菌,并与生物学分型方法进行比较.结果 通过一步法PCR能够将待检菌株准确的鉴定到布鲁氏菌种,对于猪种可以定位到生物型和疫苗株;对于牛种可以鉴定到牛种生物型1、3、4 与2、5、6、7、9两组生物型;对于羊种可以鉴定到1与2、3两组生物型和羊种疫苗株.生物学分型方法和PCR方法准确鉴定到种水平的符合率分别为98.33%和100%.结论 一步法PCR是一种快速、特异、简便而低费用的鉴定布鲁氏菌种的分子分型方法.%Objective To develop a one-step PCR assay for rapid discrimination of six Brucella species and some intraspecific biovars.Methods Using 6 pairs of primers in one-step PCR to differentiate six classical Brucella species and some biovar in ordinary PCR instrument.The tested strains including 27 reference strains of six Brucella species and 239 Brucella strains were estimated by the PCR assay and biological identification methods.Results The six Brucella species could be precisely differentiated by the onestep PCR assay from the tested strains.Five biovars and vaccine strain of B.suis species could be determined,and biovars 1,3,4 and biovars 2,5,6,7,9 of B.abortus species could be identified at the level of their biovar,moreover,biovars 1,2 and 3,and vaccine strain Rev 1 of B.melitensis species were also discriminated at the biovar and strain level.The accurate rates of the biological identification method and the PCR assay were 98.33% and 100% respectively.Conclusion One-step PCR assay was a rapid,specific,and low cost method for identification of Brucella species and discriminating biovars in ordinary PCR instrument.

  2. Structures of two cell wall-associated polysaccharides of a Streptococcus mitis biovar 1 strain. A unique teichoic acid-like polysaccharide and the group O antigen which is a C-polysaccharide in common with pneumococci

    DEFF Research Database (Denmark)

    Bergström, N; Jansson, P.-E.; Kilian, Mogens

    2000-01-01

    The cell wall of Streptococcus mitis biovar 1 strain SK137 contains the C-polysaccharide known as the common antigen of a closely related species Streptococcus pneumoniae, and a teichoic acid-like polysaccharide with a unique structure. The two polysaccharides are different entities and could...... to that of one of the two structures of C-polysaccharide previously identified in S. pneumoniae. C-polysaccharide of S. mitis is characterized by the presence, in each repeating unit, of two residues of phosphocholine and both galactosamine residues in the N-acetylated form. Immunochemical analysis showed that C......-polysaccharide constitutes the Lancefield group O antigen. Studies using mAbs directed against the backbone and against the phosphocholine moiety of the C-polysaccharide revealed several different patterns of these epitopes among 95 S. mitis and Streptococcus oralis strains tested and the exclusive presence of the group O...

  3. Effects of mixed starter composition on nisin Z production by lactococcus lactis subsp. lactis biovar. diacetylactis UL 719 during production and ripening of Gouda cheese.

    Science.gov (United States)

    Bouksaim, M; Lacroix, C; Audet, P; Simard, R E

    2000-09-10

    A starter culture system that produced both acid and nisin at acceptable rates in milk for manufacture of Gouda cheese was developed using nisin Z-producing L. lactis subsp. lactis biovar. diacetylactis UL 719 (UL 719) and a commercial Flora Danica (FD) starter culture. Different compositions of mixed cultures (0, 0.2, 0.4, 0.6 or 0.8% UL 719 with 1.4% FD) were tested for acidification and nisin Z production in milk after 12 h incubation at 30 degrees C. The 0.6/1.4% combination, selected as the optimal mixture of starter cultures, acidified milk to a suitable pH and produced nisin Z at a high concentration of 512 IU/ml. With this optimal combination, FD numbers of citrate-fermenting and non-fermenting bacteria did not change compared with the control (1.4% FD). However, with 0.8% of L. lactis strain UL 719 and 1.4% of the FD starter culture, the numbers of citrate-fermenting and non-fermenting bacteria in fermented milk decreased compared with those obtained when milk was inoculated with 0.2, 0.4 or 0.6% of UL 719 added to 1.4% FD or control cultures (1.4% FD). Mixed starter culture ratios 0.6/1.4%, 0.4/1.4% and 0.5/1.4% (UL 719/FD) were used to manufacture nisin Z containing Gouda cheese which was ripened up to 45 weeks. The composition of control cheeses made with 1.4% FD, and nisin Z-containing Gouda cheeses were similar with respect to percent moisture, fat, salt and protein. During the ripening period, the cell counts observed were approximately two logs higher in cheese made with the 0.6/1.4% mixed starter culture than in control cheese. In experimental cheese produced with 0.6/1.4% (UL 719/FD) mixed starter culture, nisin activity increased from 256 IU/g at the end of manufacture to a maximum of 512 IU/g after 6 weeks of ripening; the levels then decreased to 128 and 32 IU/g after 27 and 45 weeks of ripening, respectively. In contrast, nisin Z was not detected in experimental cheeses made with 0.4/1.4% or 0.5/1.4% (UL 719/FD) mixed starters. Using an

  4. Genotypic and phenotypic diversity of rhizobia isolated from Lathyrus japonicus indigenous to Japan.

    Science.gov (United States)

    Aoki, Seishiro; Kondo, Tetsuya; Prévost, Danielle; Nakata, Sayuri; Kajita, Tadashi; Ito, Motomi

    2010-11-01

    Sixty-one rhizobial strains from Lathyrus japonicus nodules growing on the seashore in Japan were characterized and compared to two strains from Canada. The PCR-based method was used to identify test strains with novel taxonomic markers that were designed to discriminate between all known Lathyrus rhizobia. Three genomic groups (I, II, and III) were finally identified using RAPD, RFLP, and phylogenetic analyses. Strains in genomic group I (related to Rhizobium leguminosarum) were divided into two subgroups (Ia and Ib) and subgroup Ia was related to biovar viciae. Strains in subgroup Ib, which were all isolated from Japanese sea pea, belonged to a distinct group from other rhizobial groups in the recA phylogeny and PCR-based grouping, and were more tolerant to salt than the isolate from an inland legume. Test strains in genomic groups II and III belonged to a single clade with the reference strains of R. pisi, R. etli, and R. phaseoli in the 16S rRNA phylogeny. The PCR-based method and phylogenetic analysis of recA revealed that genomic group II was related to R. pisi. The analyses also showed that genomic group III harbored a mixed chromosomal sequence of different genomic groups, suggesting a recent horizontal gene transfer between diverse rhizobia. Although two Canadian strains belonged to subgroup Ia, molecular and physiological analyses showed the divergence between Canadian and Japanese strains. Phylogenetic analysis of nod genes divided the rhizobial strains into several groups that reflected the host range of rhizobia. Symbiosis between dispersing legumes and rhizobia at seashore is discussed.

  5. Rhizobial Diversity and Nodulation Characteristics of the Extremely Promiscuous Legume Sophora flavescens.

    Science.gov (United States)

    Jiao, Yin Shan; Liu, Yuan Hui; Yan, Hui; Wang, En Tao; Tian, Chang Fu; Chen, Wen Xin; Guo, Bao Lin; Chen, Wen Feng

    2015-12-01

    In present study, we report our extensive survey on the diversity and biogeography of rhizobia associated with Sophora flavescens, a sophocarpidine (matrine)-containing medicinal legume. We additionally investigated the cross nodulation, infection pattern, light and electron microscopies of root nodule sections of S. flavescens infected by various rhizobia. Seventeen genospecies of rhizobia belonging to five genera with seven types of symbiotic nodC genes were found to nodulate S. flavescens in natural soils. In the cross-nodulation tests, most representative rhizobia in class α-Proteobacteria, whose host plants belong to different cross-nodulation groups, form effective indeterminate nodules, while representative rhizobia in class β-Proteobacteria form ineffective nodules on S. flavescens. Highly host-specific biovars of Rhizobium leguminosarum (bv. trifolii and bv. viciae) and Rhizobium etli bv. phaseoli could establish symbioses with S. flavescens, providing further evidence that S. flavescens is an extremely promiscuous legume and it does not have strict selectivity on either the symbiotic genes or the species-determining housekeeping genes of rhizobia. Root-hair infection is found as the pattern that rhizobia have gained entry into the curled root hairs. Electron microscopies of ultra-thin sections of S. flavescens root nodules formed by different rhizobia show that the bacteroids are regular or irregular rod shape and nonswollen types. Some bacteroids contain poly-β-hydroxybutyrate (PHB), while others do not, indicating the synthesis of PHB in bacteroids is rhizobia-dependent. The extremely promiscuous symbiosis between S. flavescens and different rhizobia provide us a basis for future studies aimed at understanding the molecular interactions of rhizobia and legumes.

  6. [Nitrogenase, hydrogenase and nitrate reductase activities, oxygen consumption, and ATP content in nodules formed by strains of Rhizobium leguminosarum 128C53 and 300 in symbiosis with pea plants].

    Science.gov (United States)

    Bedmar, E J; Olivares, J

    1986-10-01

    The nitrogenase activity, nitrate reductase activity and oxygen uptake as well as the hydrogen incorporation and ATP content were examined in the root nodules and bacteroids, respectively, formed by Rhizobium leguminosarum strains 128C53 (hydrogenase positive) and 300 (hydrogenase negative) in symbiosis with Pisum sativum plants grown in the presence of 2 mM KNO3. The strain 128C53 showed the greatest values for all parameters analyzed, except for the nitrate reductase activity, which was higher for the strain 300. Similarly, nodule nitrate reductase activity in strain 300 was greater than that in strain 128C53 when plants grew in the absence of combined nitrogen. In general, the highest values were obtained when determinations were made after 7 hours of plant illumination. However, the hydrogenase activity of strain 128C53 and the nitrate reductase activities of both strains increased with the light period, reaching a maximum after 14 hours of illumination. These results suggest that the benefits derived from the superior symbiotic properties and from the presence of hydrogenase activity in strain 128C53 could be counteracted by the higher rates of the nodule nitrate reductase activity in strain 300.

  7. Genetic diversity of resident soil rhizobia isolated from nodules of distinct hairy vetch genotypes

    Science.gov (United States)

    Hairy vetch (Vicia villosa Roth) is widely grown as a legume cover crop throughout the U.S.A., with biological nitrogen fixation (BNF) through symbiosis with Rhizobium leguminosarum biovar viciae (Rlv) being one of the most sought after benefits of its cultivation. This study determined if HV culti...

  8. Number and Effectiveness of Pea Rhizobia in Danish Soils

    DEFF Research Database (Denmark)

    Engvild, K.C.

    1989-01-01

    Most of 44 Danish soils tested contain between 1000 and 10 000 pea rhizobia (Rhizobium leguminosarum biovar viceae) per gram. Pea rhizobia were not detected in acid moor and forest soils. Only one case of failed nodulation in peas in the field has been noted, in spots in a reclaimed sandy heath...

  9. Underexpression of Ap from R-Plasmids in Fast-Growing Rhizobium Species

    Science.gov (United States)

    Sikka, Virendra K.; Kumar, Sushil

    1984-01-01

    The presence of the plasmid RP1 in the cells of Rhizobium leguminosarum strains Rld1, 300, and 248, R. phaseoli 1233, R. trifolii strains T1 and 6661, and R. meliloti 4013 was found to appreciably increase bacterial resistance toward kanamycin and tetracycline but not toward ampicillin. The presence of 16 other R-plasmids in R. leguminosarum was also found to either not increase or only marginally increase bacterial resistance toward ampicillin. It appears now that underexpression of the plasmid-specified ampicillin function is common to most fast- and slow-growing rhizobia. PMID:16346686

  10. Effects of high temperature on survival, symbiotic performance and genomic modifications of bean nodulating Rhizobium strains Sobrevivência, fixação de nitrogênio e modificações genéticas em estirpes de Rhizobium sp. efetivas na nodulação do feijoeiro, expostas à altas temperaturas

    OpenAIRE

    1998-01-01

    High temperatures can affect the survival, establishment and symbiotic properties of Rhizobium strains. Bean nodulating Rhizobium strains are considered particularly sensitive because on this strains genetic recombinations and/or deletions occur frequently, thus compromising the use of these bacteria as inoculants. In this study R. tropici and R. leguminosarum bv. phaseoli strains isolated from Cerrado soils were exposed to thermal stress and the strains’ growth, survival and symbiotic relati...

  11. Control biológico del marchitamiento vascular causado por Fusarium oxysporum f. sp. phaseoli en fríjol Phaseolus vulgaris L., mediante la acción combinada de Entrophospora colombiana, Trichoderma sp. Y Pseudomonas fluorescens

    Directory of Open Access Journals (Sweden)

    Avendaño Camila

    2006-06-01

    Hidden="false" UnhideWhenUsed="false" QFormat="true" Name="Intense Emphasis" /> Entrophospora colombiana, Trichoderma sp., Pseudomonas fluorescens y una combinación de estos antagonistas fueron evaluados como biocontroladores de Fusarium oxysporumf. sp. Phaseoli en plantas de fríjol de la variedad ‘ICA Tundama’. El ensayo se estableció en una casa de malla del Programa nacional de manejo integrado de plagas (MIP de la Corporación Colombiana de Investigación Agropecuaria (Corpoica, en el Centro de Investigación Tibaitat

  12. Humoral Immunity to Commensal Oral Bacteria in Human Infants: Salivary Secretory Immunoglobulin A Antibodies Reactive with Streptococcus mitis biovar 1, Streptococcus oralis, Streptococcus mutans, and Enterococcus faecalis during the First Two Years of Life

    Science.gov (United States)

    Cole, Michael F.; Bryan, Stacey; Evans, Mishell K.; Pearce, Cheryl L.; Sheridan, Michael J.; Sura, Patricia A.; Wientzen, Raoul L.; Bowden, George H. W.

    1999-01-01

    Secretory immunoglobulin A (SIgA) antibodies reactive with the pioneer oral streptococci Streptococcus mitis biovar 1 and Streptococcus oralis, the late oral colonizer Streptococcus mutans, and the pioneer enteric bacterium Enterococcus faecalis in saliva samples from 10 human infants from birth to age 2 years were analyzed. Low levels of salivary SIgA1 and SIgA2 antibodies reactive with whole cells of all four species were detected within the first month after birth, even though S. mutans and E. faecalis were not recovered from the mouths of the infants during the study period. Although there was a fivefold increase in the concentration of SIgA between birth and age 2 years, there were no differences between the concentrations of SIgA1 and SIgA2 antibodies reactive with the four species over this time period. When the concentrations of SIgA1 and SIgA2 antibodies reactive with all four species were normalized to the concentrations of SIgA1 and SIgA2 in saliva, SIgA1 and SIgA2 antibodies reactive with these bacteria showed a significant decrease from birth to 2 years of age. Adsorption of each infant’s saliva with cells of one species produced a dramatic reduction of antibodies recognizing the other three species. Sequential adsorption of saliva samples removed all SIgA antibody to the bacteria, indicating that the SIgA antibodies were directed to antigens shared by all four species. The induction by the host of a limited immune response to common antigens that are likely not involved in adherence may be among the mechanisms that commensal streptococci employ to persist in the oral cavity. PMID:10085031

  13. An amino-terminal secretion signal is required for YplA export by the Ysa, Ysc, and flagellar type III secretion systems of Yersinia enterocolitica biovar 1B.

    Science.gov (United States)

    Warren, Sasha M; Young, Glenn M

    2005-09-01

    Yersinia enterocolitica biovar 1B maintains three distinct type III secretion (TTS) systems, which independently operate to target proteins to extracellular sites. The Ysa and Ysc systems are prototypical contact-dependent TTS systems that translocate toxic effectors to the cytosols of targeted eukaryotic host cells during infection. The flagellar TTS system is utilized during the assembly of the flagellum and is required for secretion of the virulence-associated phospholipase YplA to the bacterial milieu. When ectopically produced, YplA is also a secretion substrate for the Ysa and Ysc TTS systems. In this study, we define elements that allow YplA recognition and export by the Ysa, Ysc, and flagellar TTS systems. Fusion of various amino-terminal regions of YplA to Escherichia coli alkaline phosphatase (PhoA) lacking its native secretion signal demonstrated that the first 20 amino acids or corresponding mRNA codons of YplA were sufficient for export of YplA-PhoA chimeras by each TTS system. Export of native YplA by each of the three TTS systems was also found to depend on the integrity of its amino terminus. Introduction of a frameshift mutation or deletion of yplA sequences encoding the amino-terminal 20 residues negatively impacted YplA secretion. Deletion of other yplA regions was tolerated, including that resulting in the removal of amino acid residues 30 through 40 of the polypeptide and removal of the 5' untranslated region of the mRNA. This work supports a model in which independent and distantly related TTS systems of Y. enterocolitica recognize protein substrates by a similar mechanism.

  14. Evaluation of the ability of two multiplex PCR assays (Bruce-ladder and Suis-ladder) to distinguish six Brucella species and Brucella suis at the biovar level%应用多重PCR鉴别布鲁氏菌种及猪种5个生物型研究

    Institute of Scientific and Technical Information of China (English)

    陈军; 崔步云; 赵鸿雁; 朴东日; 姜海; 邰新平; 田国忠

    2013-01-01

    Objective To evaluate the ability of two types of multiplex PCR assays (Bruce-ladder and Suis-ladder) to distinguish six Brucella species and five biovars of Brucella suis. Methods A Bruce-ladder multiplex PCR assay was performed using 8 pairs of primers to distinguish six Brucella species. A Suis-ladder multiplex PCR assay was performed using 4 pairs of primers to distinguish five biovars of B. suis. The tested strains, which consisted of 27 reference strains of six Brucella species and 239 Brucella isolates, were examined using PCR assays and methods of biological identification. Results The Bruce-ladder multiplex PCR assay differentiated six Brucella species, including Brucella abortus, Brucella melitensis , Brucella suis , Brucella canis , Brucella ovis , and Brucella neotomae , in a single step. The Suis-ladder multiplex PCR assay differentiated five biovars of B. suis in a single step. The electrophoresis patterns of the vaccine strain S2 and biovar 1 of B. suis were identical. The total rate of concordance between methods of biological identification and multiplex PCR assays was 100%. Conclusion The Bruce-ladder and Suis-ladder multiplex PCR assays are rapid and specific methods of respectively identifying Brucella species and B. suis at the biovar level.%目的 应用布鲁氏菌种多重PCR和猪种多重PCR对布鲁氏菌进行鉴定. 方法 对两套多重PCR方法进行条件优化,应用布鲁氏菌参考菌株、疫苗株和临床分离菌株进行评价,并与生物学分型方法进行比较. 结果 布鲁氏菌种多重PCR扩增(包括牛种布鲁氏菌8个生物型,猪种5个生物型,羊种3个生物型,以及绵羊附睾、犬和沙漠森林野鼠种各1个生物型)可获得152~1 682 bp的8个DNA片段,但种间DNA片段数不一.猪种多重PCR扩增猪种5个生物型菌株得到197~774 bp的7个DNA片段,不同生物型的DNA扩增图谱不同;猪种疫苗株S2扩增图谱与猪种生物1型相同,多重PCR分型方法与生物学

  15. Effects of Culture Conditions on Rhizobium leguminosarum Cell Growth and CoQ10 Production%发酵条件对豌豆根瘤菌细胞生长和辅酶Q10合成的影响

    Institute of Scientific and Technical Information of China (English)

    王根华; 钱和

    2003-01-01

    以豌豆根瘤菌(Rhizobium leguminosarum)1.172 3为研究对象,对影响细胞生长和辅酶Q10合成的培养条件:温度、pH值、接种量、装液量、收集时间等进行了研究.结果表明:菌株的最适生长条件为pH值5.0,温度30 ℃,接种量体积分数2%,装液量25 mL,培养时间24 h,辅酶Q10的合成量最高.

  16. Microsymbionts of Phaseolus vulgaris in acid and alkaline soils of Mexico.

    Science.gov (United States)

    Verástegui-Valdés, Myrthala M; Zhang, Yu Jing; Rivera-Orduña, Flor N; Cheng, Hai-Ping; Sui, Xing Hua; Wang, En Tao

    2014-12-01

    In order to investigate bean-nodulating rhizobia in different types of soil, 41 nodule isolates from acid and alkaline soils in Mexico were characterized. Based upon the phylogenetic studies of 16S rRNA, atpD, glnII, recA, rpoB, gyrB, nifH and nodC genes, the isolates originating from acid soils were identified as the phaseoli symbiovar of the Rhizobium leguminosarum-like group and Rhizobium grahamii, whereas the isolates from alkaline soils were defined as Ensifer americanum sv. mediterranense and Rhizobium radiobacter. The isolates of "R. leguminosarum" and E. americanum harbored nodC and nifH genes, but the symbiotic genes were not detected in the four isolates of the other two species. It was the first time that "R. leguminosarum" and E. americanum have been reported as bean-nodulating bacteria in Mexico. The high similarity of symbiotic genes in the Rhizobium and Ensifer populations showed that these genes had the same origin and have diversified recently in different rhizobial species. Phenotypic characterization revealed that the "R. leguminosarum" population was more adapted to the acid and low salinity conditions, while the E. americanum population preferred alkaline conditions. The findings of this study have improved the knowledge of the diversity, geographic distribution and evolution of bean-nodulating rhizobia in Mexico.

  17. Random amplified polymorphic DNA analysis of effective Rhizobium sp. associated with beans cultivated in brazilian cerrado soils Caracterização, via RAPD, de estirpes efetivas de Rhizobium sp associadas ao feijoeiro cultivado em solos de cerrado no Brasil

    Directory of Open Access Journals (Sweden)

    Isnia Aparecida de Oliveira

    2000-03-01

    Full Text Available Efficient bean nodulating Rhizobium strains, isolated from different Brazilian cerrado soils, were characterized by RAPD. This study showed great genetic heterogeneity among R. tropici and R. leguminosarum bv. phaseoli strains and allowed the constitution of genetic clusters, besides indicating the most suitable primers for this characterization. The groups of genetically distinct strains can be used in competitiveness studies to select appropriate Rhizobium strains for bean inoculation in cerrado soils.Estirpes de Rhizobium eficientes na nodulação do feijoeiro, isoladas de diferentes solos da região do cultivo dessa leguminosa nos cerrados brasileiros, foram caracterizadas via RAPD. Esse estudo mostrou grande heterogeneidade genética entre as estirpes de R. tropici e R. leguminosarum bv. phaseoli testadas e permitiu a definição de grupos genéticos, além de indicar os "primers" mais adequados para essa caracterização. Os grupos de estirpes geneticamente distintas podem ser usados em estudos de competitividade, importantes para obtenção de resultados positivos na inoculação dessa leguminosa em solos de cerrado.

  18. Impact of rhizobial inoculation and nitrogen utilization in plant growth promotion of maize (Zea mays L.

    Directory of Open Access Journals (Sweden)

    RAMESH K. SINGH

    2013-05-01

    Full Text Available Singh RK, Malik N, Singh S. 2013. Impact of rhizobial inoculation and nitrogen utilization in plant growth promotion of maize (Zea mays L.. Nusantara Bioscience 5: 8-14. During the course of growing population demands there has been an increasing interest in exploring the possibility of extending the beneficial interaction between cereals and plant growth promoting rhizobacteria (PGPR. Endophytes are a group of microorganism that resides mostly in the intercellular space of various parts of plants including cereals. Assessment of plant growth promoting properties of the five-rhizobial strains belonging to α subclass i.e. Rhizobium leguminosarum bv. phaseoli RRE6 and R. undicola RRE36 and those belonging to β subclass i.e. Burkholderia cepacia (RRE3, RRE5, RRE25 was done by growing maize plants inoculated with these strains. Inoculated maize plants showed a significant increase in plant height, root length, shoot and root dry weight over uninoculated control. R. leguminosarum bv. phaseoli RRE6 and B. cepacia RRE5 among the α and β-subclass representatives respectively, gave the best inoculation response. Effect of nitrate supplementation upon maize-RRE6 and RRE5 association was also studied and a significant increase in all the growth parameters and colonization ability was recorded when nitrate was present as a supplement over uninoculated control and maize-RRE6 and RRE5 in absence of external nitrate.

  19. Effects of inoculation with different Rhizobium leguminosarum strains on growth performances,yield,and grain quality of a semi-leafless pea variety%不同根瘤菌株对半无叶型豌豆生育特征、产量及品质的影响

    Institute of Scientific and Technical Information of China (English)

    郭丽梅; 陈恭; 隋新华; 张世晨; 杨亚东; 龙金成; 胡跃高; 曾昭海

    2012-01-01

    In order to study the effects of inoculation with Rhizobium leguminosarum strains on growth performances,yield,and grain quality of Canadian pea M.P.1824,a pot experiment was conducted involving inoculating with eight different Rhizobium leguminosarum strains.The results showed that,compared with no-inoculated control,rhizobium inoculation could extend pea's growth periods,produce a better growth in pea's ripening period,increase yield,and increase grain crude protein and fiber content,but reduce the content of soluble sugar.When inoculated with rhizobium ACCC 16058,periods of flowering beginning,flowering and podding beginning,podding,pod ripening delayed by 3.1,5.2,4.8,and 12 d,respectively.The number of branches at flowering and podding beginning period and plant height at pod ripening period increased by 45.5% and 16.61% respectively.In addition,pods per plant,grains per plant,grain dry weight per plant,and grain dry weight per pot were significantly(P0.05) increased by 76.67%,85.54%,65.13%,and 36.71%,respectively.Inoculating with commercial rhizobium F98 significantly(P0.05) raised the crude protein content and reduced the soluble sugar content,with variable quantity of +12.37% and-37.77%.Inoculating with CCBAU 43228 and CCBAU 43232 significantly(P0.01) increased the content of crude fiber by 1.24 and 1.20 times compared with CK,and by 39.7% and 37.6% compared with F98.While inoculating with CCBAU 43232 decreased the content of soluble sugar by 35.65%.In conclusion,for pot experiment,the comprehensive performance of M.P.1824 inoculated with rhizobium ACCC 16058 was the best.%在盆栽条件下,对加拿大豌豆品种M.P.1824接种8株豌豆根瘤菌菌株,研究其对豌豆生育特征、产量及品质的影响。结果显示:与不接种对照相比,接种根瘤菌可以延长豌豆生育期,促进后期豌豆植株生长,提高产量,增加籽粒粗蛋白质、粗纤维含量,以及降低可溶性糖含

  20. Phylogenetic diversity based on rrs, atpD, recA genes and 16S-23S intergenic sequence analyses of rhizobial strains isolated from Vicia faba and Pisum sativum in Peru.

    Science.gov (United States)

    Santillana, Nery; Ramírez-Bahena, Martha Helena; García-Fraile, Paula; Velázquez, Encarna; Zúñiga, Doris

    2008-03-01

    In this study 17 isolates from effective nodules of Vicia faba and Pisum sativum var. macrocarpum growing in different soils from Peru were isolated and characterized. The isolates, presenting 11 different RAPD profiles, were distributed in three groups on the basis of their 16S-RFLP patterns. The 16S rRNA gene sequences of strains from 16S-RFLP groups I, II and III were closely related (identities higher than 99.5%) to Rhizobium leguminosarum bv. trifolii DSM 30141 (=ATCC 14480), R. leguminosarum bv. viciae DSM 30132(T) and Rhizobium etli CFN42(T) (=USDA 9032(T)), respectively. The analysis of the 16S-23S intergenic spacer (ITS) and two housekeeping genes, atpD and recA, confirmed the identification of strains from group I, however those from groups II and III were phylogenetically divergent to strains DSM 30132(T) and CFN42(T). These results support the fact that the 16S rRNA gene is not adequate for identification at species level within genus Rhizobium and suggest the existence of putative new species within the phylogenetic group of R. leguminosarum. They also confirm the need of a taxonomic revision of R. leguminosarum since the reference strains of the three biovars included in this study are phylogenetically divergent according to their ITS, atpD and recA gene sequences.

  1. Oligo- and polysaccharide synthesis by Rhizobium leguminosarum and Rhizobium meliloti

    NARCIS (Netherlands)

    Breedveld, M.W.

    1992-01-01

    Rhizobium and Agrobacterium species are capable of synthesizing a variety of extracellular and cellular oligo- and polysaccharides. Changes in environmental conditions may all affect the composition, physical properties, and relative amounts of

  2. Oligo- and polysaccharide synthesis by Rhizobium leguminosarum and Rhizobium meliloti.

    NARCIS (Netherlands)

    Breedveld, M.W.

    1992-01-01

    Rhizobium and Agrobacterium species are capable of synthesizing a variety of extracellular and cellular oligo- and polysaccharides. Changes in environmental conditions may all affect the composition, physical properties, and relative amounts of oligo- and polysaccharides. Interest in the field of Rh

  3. Oligo- and polysaccharide synthesis by Rhizobium leguminosarum and Rhizobium meliloti.

    OpenAIRE

    Breedveld, M W

    1992-01-01

    Rhizobium and Agrobacterium species are capable of synthesizing a variety of extracellular and cellular oligo- and polysaccharides. Changes in environmental conditions may all affect the composition, physical properties, and relative amounts of oligo- and polysaccharides. Interest in the field of Rhizobium polys accharides has resulted from a development in two distinct areas, (i) the role of oligo- and polysaccharides in the microbe- plant interaction, and (ii) studies on the physico- chemic...

  4. Diversity and numbers of root-nodule bacteria (rhizobia in Polish soils

    Directory of Open Access Journals (Sweden)

    Stefan Martyniuk

    2011-01-01

    Full Text Available Using a sand pouch-plant infection method, populations of several species of root-nodule bacteria (rhizobia were enumerated in eighty soils collected throughout Poland. Rhizobium leguminosarum bv. viciae (symbionts of pea, faba bean, vetch and R. leguminosarum bv. trifolii (symbionts of clover were detected in 77 and 76 soils, respectively. Most of these soils contained moderate and high numbers of these species of the rhizobia. Symbionts of beans, R. leguminosarum bv. phaseoli, were assessed in 76 soils; of this number 15 soils had no detectable populations of bean rhizobia and in 40 soils high or moderate numbers of these bacteria were found. Bradyrhizobium sp. (Lupinus, root-nodule bacteria of lupine and serradella, were absent in 19 soils, out of 80 tested, and 34 soils were colonised by high or moderate populations of bradyrhizobia. Sinorhizobium meliloti, rhizobia nodulating alfalfa, were sparse in the examined soils; with 56 soil containing no detectable numbers of S. meliloti and only 6 soils harbouring high or moderate populations of this species. The estimated numbers of the rhizobia in the studied soils were also related to some physical and chemical properties of these soils.

  5. Identification and characterization of regions of difference between the Salmonella Gallinarum biovar Gallinarum and the Salmonella Gallinarum biovar Pullorum genomes.

    Science.gov (United States)

    Batista, Diego Felipe Alves; Freitas Neto, Oliveiro Caetano; Barrow, Paul Andrew; Oliveira, Marcos Túlio de; Almeida, Adriana Maria; Ferraudo, Antonio Sergio; Berchieri, Angelo

    2015-03-01

    Salmonella Gallinarum is the causative agent of fowl typhoid, a severe septicaemic disease that affects birds of all ages, whereas S. Pullorum causes pullorum disease, a systemic disorder affecting primarily young birds. A proportion of birds with pullorum disease become carriers and are thereby able to transmit S. Pullorum vertically. Although these two pathogens cause distinct diseases, they are otherwise phenotypically and genetically similar. Therefore, the small variations that lead to the differences in virulence must have a genetic basis which currently is unknown. In the present study, we compared the genome sequences of S. Gallinarum (strains: SG287/91 and SG9) and S. Pullorum (strains: SP_CDC, SP_RKS, SP_FCAV, SP_S06) and identified 223 regions of difference (RODs), characterized by indels which were detected by using the software Artemis Comparison Tool. Some of the RODs led to pseudogenes frequently formed by frameshifts and premature stop codons in genes primarily involved in virulence and metabolism. We further verified the presence of some conserved RODs by PCR in 26 isolates of S. Gallinarum and 17 of S. Pullorum in order to extrapolate data analyses from genome comparison to field strains. The variations observed in virulence-related genes of S. Gallinarum and S. Pullorum appear not to be sufficient to explain the differences between the distinct biology of infection of fowl typhoid and pullorum disease. Thus, we suggest that the identified pseudogenes affecting metabolism might play a greater role during infection than previously thought.

  6. Analysis of Kenyan isolates of Fusarium solani f. sp. phaseoli from ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-06-03

    Jun 3, 2008 ... were determined by visual observation while pigmentation on the mycelium was determined with ..... pathogenicity, a correlation analysis was done using the computer .... death syndrome (SDS) on soybean foliage, a disease.

  7. Effects of high temperature on survival, symbiotic performance and genomic modifications of bean nodulating Rhizobium strains Sobrevivência, fixação de nitrogênio e modificações genéticas em estirpes de Rhizobium sp. efetivas na nodulação do feijoeiro, expostas à altas temperaturas

    Directory of Open Access Journals (Sweden)

    Patrícia P. Pinto

    1998-10-01

    Full Text Available High temperatures can affect the survival, establishment and symbiotic properties of Rhizobium strains. Bean nodulating Rhizobium strains are considered particularly sensitive because on this strains genetic recombinations and/or deletions occur frequently, thus compromising the use of these bacteria as inoculants. In this study R. tropici and R. leguminosarum bv. phaseoli strains isolated from Cerrado soils were exposed to thermal stress and the strains’ growth, survival and symbiotic relationships as well as alterations in their genotypic and phenotypic characteristics were analyzed. After successive thermal shocks at 45ºC for four hours, survival capacity appeared to be strain-specific, independent of thermo-tolerance and was more apparent in R. tropici strains. Certain R. leguminosarum bv. phaseoli strains had significant alterations in plant dry weight and DNA patterns obtained by AP-PCR method. R. tropici strains (with the exception of FJ2.21 were more stable than R. leguminosarum bv. phaseoli strains because no significant phenotypic alterations were observed following thermal treatments and they maintained their original genotypic pattern after inoculation in plants.Altas temperaturas podem afetar a sobrevivência, estabelecimento e as propriedades simbióticas em estirpes de Rhizobium. As estirpes capazes de nodular o feijoeiro têm sido consideradas particularmente sensíveis, porque nessas estirpes é comum a ocorrência de recombinações e/ou deleções genômicas comprometendo, muitas vezes, a sua utilização como inoculantes. Neste trabalho, procurou-se avaliar a capacidade de crescimento e sobrevivência em temperaturas elevadas de estirpes de Rhizobium efetivas na fixação de nitrogênio no feijoeiro isoladas dos cerrados, bem como avaliar suas características fenotípicas e genotípicas após choque térmico. A capacidade de sobrevivência à temperaturas elevadas, avaliada após choques térmicos sucessivos (45ºC por 4

  8. Novel Rhizobium lineages isolated from root nodules of the common bean (Phaseolus vulgaris L.) in Andean and Mesoamerican areas.

    Science.gov (United States)

    Ribeiro, Renan Augusto; Ormeño-Orrillo, Ernesto; Dall'Agnol, Rebeca Fuzinatto; Graham, Peter H; Martinez-Romero, Esperanza; Hungria, Mariangela

    2013-09-01

    The taxonomic affiliations of nineteen root-nodule bacteria isolated from the common bean (Phaseolus vulgaris L.) in Mexico, Ecuador and Brazil were investigated by analyses of 16S rRNA and of four protein-coding housekeeping genes. One strain from Mexico could be assigned to Rhizobium etli and two from Brazil to Rhizobium leucaenae, whereas another from Mexico corresponded to a recently described bean-nodulating species-level lineage related to R. etli and Rhizobium phaseoli. Ten strains isolated in Ecuador and Mexico corresponded to three novel Rhizobium lineages that fall into the R. phaseoli/R. etli/Rhizobium leguminosarum clade. One of those lineages, with representatives isolated mostly from Ecuador, seems to be dominant in beans from that Andean region. Only one of the Mexican strains clustered within the Rhizobium tropici clade, but as an independent lineage. Interestingly, four strains were affiliated with species within the Rhizobium radiobacter clade. The existence of yet non-described native Rhizobium lineages in both the Andean and Mesoamerican areas is discussed in relation to common-bean diversity and environmental conditions.

  9. Multivariate analysis and determination of the best indirect selection criteria to genetic improvement the biological nitrogen fixation ability in common bean genotypes (Phaseolus vulgaris L.

    Directory of Open Access Journals (Sweden)

    Golparvar Reza Ahmad

    2012-01-01

    Full Text Available In order to determine the best indirect selection criteria for genetic improvement of biological nitrogen fixation, sixty four common bean genotypes were cultivated in two randomized complete block design. Genotypes were inoculated with bacteria Rhizobium legominosarum biovar Phaseoli isolate L-109 only in one of the experiments. The second experiment was considered as check for the first. Correlation analysis showed positive and highly significant correlation of majority of the traits with percent of nitrogen fixation. Step-wise regression designated that traits percent of total nitrogen of shoot, number of nodule per plant and biological yield accounted for 92.3 percent of variation exist in percent of nitrogen fixation. Path analysis indicated that these traits have direct and positive effect on percent of nitrogen fixation. Hence, these traits are promising indirect selection criteria for genetic improvement of nitrogen fixation capability in common bean genotypes especially in early generations.

  10. Biosynthesis of compatible solutes in rhizobial strains isolated from Phaseolus vulgaris nodules in Tunisian fields

    Directory of Open Access Journals (Sweden)

    Nieto Joaquín J

    2010-07-01

    Full Text Available Abstract Background Associated with appropriate crop and soil management, inoculation of legumes with microbial biofertilizers can improve food legume yield and soil fertility and reduce pollution by inorganic fertilizers. Rhizospheric bacteria are subjected to osmotic stress imposed by drought and/or NaCl, two abiotic constraints frequently found in semi-arid lands. Osmostress response in bacteria involves the accumulation of small organic compounds called compatible solutes. Whereas most studies on rhizobial osmoadaptation have focussed on the model species Sinorhizobium meliloti, little is known on the osmoadaptive mechanisms used by native rhizobia, which are good sources of inoculants. In this work, we investigated the synthesis and accumulations of compatible solutes by four rhizobial strains isolated from root nodules of Phaseolus vulgaris in Tunisia, as well as by the reference strain Rhizobium tropici CIAT 899T. Results The most NaCl-tolerant strain was A. tumefaciens 10c2, followed (in decreasing order by R. tropici CIAT 899, R. leguminosarum bv. phaseoli 31c3, R. etli 12a3 and R. gallicum bv. phaseoli 8a3. 13C- and 1H-NMR analyses showed that all Rhizobium strains synthesized trehalose whereas A. tumefaciens 10c2 synthesized mannosucrose. Glutamate synthesis was also observed in R. tropici CIAT 899, R. leguminosarum bv. phaseoli 31c3 and A. tumefaciens 10c2. When added as a carbon source, mannitol was also accumulated by all strains. Accumulation of trehalose in R. tropici CIAT 899 and of mannosucrose in A. tumefaciens 10c2 was osmoregulated, suggesting their involvement in osmotolerance. The phylogenetic analysis of the otsA gene, encoding the trehalose-6-phosphate synthase, suggested the existence of lateral transfer events. In vivo 13C labeling experiments together with genomic analysis led us to propose the uptake and conversion pathways of different carbon sources into trehalose. Collaterally, the β-1,2-cyclic glucan from R

  11. Role of symbiotic auxotrophy in the Rhizobium-legume symbioses.

    Directory of Open Access Journals (Sweden)

    Jurgen Prell

    Full Text Available Rhizobium leguminosarum bv. viciae mutants unable to transport branched-chain amino acids via the two main amino acid ABC transport complexes AapJQMP and BraDEFGC produce a nitrogen starvation phenotype when inoculated on pea (Pisum sativum plants [1], [2]. Bacteroids in indeterminate pea nodules have reduced abundance and a lower chromosome number. They reduce transcription of pathways for branched-chain amino acid biosynthesis and become dependent on their provision by the host. This has been called "symbiotic auxotrophy".A region important in solute specificity was identified in AapQ and changing P144D in this region reduced branched-chain amino acid transport to a very low rate. Strains carrying P144D were still fully effective for N(2 fixation on peas demonstrating that a low rate of branched amino acid transport in R. leguminosarum bv. viciae supports wild-type rates of nitrogen fixation. The importance of branched-chain amino acid transport was then examined in other legume-Rhizobium symbioses. An aap bra mutant of R. leguminosarum bv. phaseoli also showed nitrogen starvation symptoms when inoculated on French bean (Phaseolus vulgaris, a plant producing determinate nodules. The phenotype is different from that observed on pea and is accompanied by reduced nodule numbers and nitrogen fixation per nodule. However, an aap bra double mutant of Sinorhizobium meliloti 2011 showed no phenotype on alfalfa (Medicago sativa.Symbiotic auxotrophy occurs in both determinate pea and indeterminate bean nodules demonstrating its importance for bacteroid formation and nodule function in legumes with different developmental programmes. However, only small quantities of branched chain amino acids are needed and symbiotic auxotrophy did not occur in the Sinorhizobium meliloti-alfalfa symbiosis under the conditions measured. The contrasting symbiotic phenotypes of aap bra mutants inoculated on different legumes probably reflects altered timing of amino acid

  12. Identification and characterization of symbiotic genes on the Rhizobium leguminosarum PRE sym-plasmid.

    NARCIS (Netherlands)

    Schetgens, T.M.P.

    1986-01-01

    Bacteria of the genera Rhizobium and Bradyrhizobium are unique in their quality to form nitrogen-fixing root nodules in symbiosis with leguminous plants. In fast-growing Rhizobium bacteria the genes involved in host recognition and nodule development ( nod ) and in nitrog

  13. Involvement of Rhizobium leguminosarum nodulation genes in gene expression in pea root hairs.

    NARCIS (Netherlands)

    Gloudemans, T.; Bhuvaneswari, T.V.; Moerman, M.; Brussel, van T.; Kammen, van A.; Bisseling, T.

    1989-01-01

    The mRNA population in pea root hairs was characterized by means of in vitro translation of total root hair RNA followed by 2-dimensional gel electrophoresis of the translation products. Root hairs contain several mRNAs not detectable in total RNA preparations from roots. Most of these root hair-spe

  14. Nitrogen fixation by Rhizobium leguminosarum PRE; a genetical and biochemical approach.

    NARCIS (Netherlands)

    Klein Lankhorst, R.

    1989-01-01

    Nitrogen fix ation by Rhizobium and Bradyrhizobium bacteria in symbiosis with their leguminous host plants forms an attractive alternative for the industrial production of nitrogenous fertilizers, both from an economic as well as an enviromnental point of view, and is the topic of many scientific re

  15. Isolation of Rhizobium Spp. Bacteria which as Used Microbial Fertilizer from Wild Leguminosarum Plants

    Directory of Open Access Journals (Sweden)

    Hatice Öğütcü

    2014-04-01

    Full Text Available In our study used wild leguminous plants (Medicago sativa, M. lupulina and M. varia Erzurum belongs to the high altitude (2000 - 2500m regions ( Palandöken mountain, Alibaba mountain, Turnagöl mountain, Hasanbaba mountain, Eğerli mountain, Yıldırım mountain, Çubuklu mountain, Deveboynu locality, Kayakyolu locality, Telsizler and Dumlu hill were collected during the months of June and July. Nodules were obtained from this plant were sterilized, YMA (Yeast Mannitol Agar plates were streaked and petri dishes 28+1ºC were incubated for 3-5 days. Colonies appear after incubation typically constitute (white, clear or slightly opaque, mucosity, round, raised 39 isolates were selected and transferred to tubes and refrigerated YMA were stored at +4ºC. In the next stage, cytological and biochemical analyzes of these isolates were studied to determine. For this purpose isolates; YMA containing bromothymol blue and congo red reproduction, gram stain reaction, movement and subjected to catalase and oxidase tests were evaluated. The cytological and biochemical analysis of results showed that 28 of 39 strains belonged to Rhizobium spp.

  16. Soil moisture deficit selects for desiccation tolerant Rhizobium leguminosarum bv. trifolii

    NARCIS (Netherlands)

    Ham, van Robert; O'Callaghan, Maureen; Geurts, Rene; Ridgway, Hayley J.; Ballard, Ross; Noble, Alasdair; Macara, Gregor; Wakelin, Steven A.

    2016-01-01

    Tolerance to desiccation is a highly desirable attribute for Rhizobium spp., which are widely used as symbionts of pasture legumes. Poor survival of Rhizobium spp. is of particular concern during the commercial formulation and seed application phase, but also when sown into dry fields and during sap

  17. The symbiosis between Rhizobium leguminosarum and Pisum savitum: regulation of the nitrogenase activity.

    NARCIS (Netherlands)

    Appels, M.A.

    1989-01-01

    Bacteria of the genus Rhizobium can form a symbiosis with plants of the family Leguminosae. Both bacteria and plant show considerable biochemical and morphological changes in order to develop and carry out the symbiosis. The Rhizobia induce special structures on the legumes, which are called root no

  18. The symbiosis between Rhizobium leguminosarum and Pisum sativum : regulation of the nitrogenase activity

    NARCIS (Netherlands)

    Appels, M.A.

    1989-01-01

    Bacteria of the genus Rhizobium can form a symbiosis with plants of the family Leguminosae. Both bacteria and plant show considerable biochemical and morphological changes in order to develop and carry out the symbiosis. The Rhizobia

  19. Análisis funcional de DsbA una tiol oxidorreductasa de Rhizobium leguminosarum

    OpenAIRE

    Vega de los Reyes, Rosa Mª

    2009-01-01

    Las proteínas que se exportan fuera del citoplasma bacteriano constituyen hasta un 20% del total de proteínas sintetizadas. Algunas de estas proteínas necesitan adquirir su conformación tridimensional particular en el citoplasma, incorporando frecuentemente cofactores metálicos antes de su transporte. Dicho transporte está mediado por el sistema Tat que es capaz de transportar proteínas que presentan un péptido señal característico en conformación plegada. Se ha postulado DsbA como proteína d...

  20. Experimental transmission of Corynebacterium pseudotuberculosis biovar equi in horses by house flies

    Science.gov (United States)

    The route of Corynebacterium pseudotuberculosis infection in horses remains undetermined, but transmission by insects is suspected. Scientists from CMAVE and Auburn University investigated house flies (Musca domestica L.) as possible vectors. Three ponies were directly inoculated with C. pseudotuber...

  1. Anaerobic disinfestation of tare soils contaminated with Ralstonia solanacearum biovar 2 and Globodera pallida.

    NARCIS (Netherlands)

    Overbeek, van L.S.; Runia, W.T.; Kastelein, P.; Molendijk, L.P.G.

    2014-01-01

    Tare soil is soil attached to harvested products like potato tubers. Tare soil becomes a considerable waste stream after storage, washing and processing of harvested products. There is a high risk on contamination of tare soils with (quarantine) phytopathogens, because of import of harvested product

  2. Capsules, toxins and AtxA as virulence factors of emerging Bacillus cereus biovar anthracis.

    Science.gov (United States)

    Brézillon, Christophe; Haustant, Michel; Dupke, Susann; Corre, Jean-Philippe; Lander, Angelika; Franz, Tatjana; Monot, Marc; Couture-Tosi, Evelyne; Jouvion, Gregory; Leendertz, Fabian H; Grunow, Roland; Mock, Michèle E; Klee, Silke R; Goossens, Pierre L

    2015-04-01

    Emerging B. cereus strains that cause anthrax-like disease have been isolated in Cameroon (CA strain) and Côte d'Ivoire (CI strain). These strains are unusual, because their genomic characterisation shows that they belong to the B. cereus species, although they harbour two plasmids, pBCXO1 and pBCXO2, that are highly similar to the pXO1 and pXO2 plasmids of B. anthracis that encode the toxins and the polyglutamate capsule respectively. The virulence factors implicated in the pathogenicity of these B. cereus bv anthracis strains remain to be characterised. We tested their virulence by cutaneous and intranasal delivery in mice and guinea pigs; they were as virulent as wild-type B. anthracis. Unlike as described for pXO2-cured B. anthracis, the CA strain cured of the pBCXO2 plasmid was still highly virulent, showing the existence of other virulence factors. Indeed, these strains concomitantly expressed a hyaluronic acid (HA) capsule and the B. anthracis polyglutamate (PDGA) capsule. The HA capsule was encoded by the hasACB operon on pBCXO1, and its expression was regulated by the global transcription regulator AtxA, which controls anthrax toxins and PDGA capsule in B. anthracis. Thus, the HA and PDGA capsules and toxins were co-regulated by AtxA. We explored the respective effect of the virulence factors on colonisation and dissemination of CA within its host by constructing bioluminescent mutants. Expression of the HA capsule by itself led to local multiplication and, during intranasal infection, to local dissemination to the adjacent brain tissue. Co-expression of either toxins or PDGA capsule with HA capsule enabled systemic dissemination, thus providing a clear evolutionary advantage. Protection against infection by B. cereus bv anthracis required the same vaccination formulation as that used against B. anthracis. Thus, these strains, at the frontier between B. anthracis and B. cereus, provide insight into how the monomorphic B. anthracis may have emerged.

  3. [Survival capacity of Corynebacterium pseudotuberculosis biovar ovis in different soil types from Chubut, Argentine Patagonia].

    Science.gov (United States)

    Alvarez, Laura; William, Aillin; Castro, Isabel; Valenzuela, Fernanda; Estevao Belchior, Silvia

    Corynebacterium pseudotuberculosis is transmitted among sheep in Argentine Patagonia causing pseudotuberculosis. The bacterium penetrates the skin or mucous membrane wounds, infecting the superficial lymph nodes and viscera. When surface abscesses are cut during shearing, they drain their purulent contents and contaminate tools and the soil. The objective of this work was to evaluate the survival capacity of C. pseudotuberculosis over time, in soils from the extra-Andean Patagonia region. Five types of superficial soils were collected from different areas in Chubut province (extra-Andean Patagonia), having distinctive physicochemical properties including organic matter content (very high to nonexistent), pH (neutral to strongly alkaline), electrical conductivity (saline to non-saline) and texture (sandy, clayey, silty loam). Different aliquots of each type of soil were inoculated with C. pseudotuberculosis PAT10 strain isolated from a Patagonian sheep, and were stored at room temperature. The number of surviving bacteria was determined at various times. Sixty percent (60%) of the inoculated C. pseudotuberculosis population survived for 80 to 210 days in soils with moderate to high organic matter content respectively. Silty soils favored bacterial survival, whereas the variables pH and salinity had no effect on survival. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  4. Capsules, toxins and AtxA as virulence factors of emerging Bacillus cereus biovar anthracis.

    Directory of Open Access Journals (Sweden)

    Christophe Brézillon

    2015-04-01

    Full Text Available Emerging B. cereus strains that cause anthrax-like disease have been isolated in Cameroon (CA strain and Côte d'Ivoire (CI strain. These strains are unusual, because their genomic characterisation shows that they belong to the B. cereus species, although they harbour two plasmids, pBCXO1 and pBCXO2, that are highly similar to the pXO1 and pXO2 plasmids of B. anthracis that encode the toxins and the polyglutamate capsule respectively. The virulence factors implicated in the pathogenicity of these B. cereus bv anthracis strains remain to be characterised. We tested their virulence by cutaneous and intranasal delivery in mice and guinea pigs; they were as virulent as wild-type B. anthracis. Unlike as described for pXO2-cured B. anthracis, the CA strain cured of the pBCXO2 plasmid was still highly virulent, showing the existence of other virulence factors. Indeed, these strains concomitantly expressed a hyaluronic acid (HA capsule and the B. anthracis polyglutamate (PDGA capsule. The HA capsule was encoded by the hasACB operon on pBCXO1, and its expression was regulated by the global transcription regulator AtxA, which controls anthrax toxins and PDGA capsule in B. anthracis. Thus, the HA and PDGA capsules and toxins were co-regulated by AtxA. We explored the respective effect of the virulence factors on colonisation and dissemination of CA within its host by constructing bioluminescent mutants. Expression of the HA capsule by itself led to local multiplication and, during intranasal infection, to local dissemination to the adjacent brain tissue. Co-expression of either toxins or PDGA capsule with HA capsule enabled systemic dissemination, thus providing a clear evolutionary advantage. Protection against infection by B. cereus bv anthracis required the same vaccination formulation as that used against B. anthracis. Thus, these strains, at the frontier between B. anthracis and B. cereus, provide insight into how the monomorphic B. anthracis may have emerged.

  5. Rhizobium sophorae sp. nov. and Rhizobium sophoriradicis sp. nov., nitrogen-fixing rhizobial symbionts of the medicinal legume Sophora flavescens.

    Science.gov (United States)

    Jiao, Yin Shan; Yan, Hui; Ji, Zhao Jun; Liu, Yuan Hui; Sui, Xin Hua; Wang, En Tao; Guo, Bao Lin; Chen, Wen Xin; Chen, Wen Feng

    2015-02-01

    Five bacterial strains representing 45 isolates originated from root nodules of the medicinal legume Sophora flavescens were defined as two novel groups in the genus Rhizobium based on their phylogenetic relationships estimated from 16S rRNA genes and the housekeeping genes recA, glnII and atpD. These groups were distantly related to Rhizobium leguminosarum USDA 2370(T) (95.6 % similarity for group I) and Rhizobium phaseoli ATCC 14482(T) (93.4 % similarity for group II) in multilocus sequence analysis. In DNA-DNA hybridization experiments, the reference strains CCBAU 03386(T) (group I) and CCBAU 03470(T) (group II) showed levels of relatedness of 17.9-57.8 and 11.0-42.9 %, respectively, with the type strains of related species. Both strains CCBAU 03386(T) and CCBAU 03470(T) contained ubiquinone 10 (Q-10) as the major respiratory quinone and possessed 16 : 0, 18 : 0, 19 : 0 cyclo ω8c, summed feature 8 and summed feature 2 as major fatty acids, but did not contain 20 : 3 ω6,8,12c. Phenotypic features distinguishing both groups from all closely related species of the genus Rhizobium were found. Therefore, two novel species, Rhizobium sophorae sp. nov. for group I (type strain CCBAU 03386(T) = E5(T) = LMG 27901(T) = HAMBI 3615(T)) and Rhizobium sophoriradicis sp. nov. for group II (type strain CCBAU 03470(T) = C-5-1(T) = LMG 27898(T) = HAMBI 3510(T)), are proposed. Both groups were able to nodulate Phaseolus vulgaris and their hosts of origin (Sophora flavescens) effectively and their nodulation gene nodC was phylogenetically located in the symbiovar phaseoli.

  6. Comparative effectiveness of different Rhizobium sp. for improving growth and yield of maize (Zea mays L.

    Directory of Open Access Journals (Sweden)

    Ijaz Mehboob, Zahir Ahmad Zahir, Muhammad Arshad, Muhammad Khalid

    2012-05-01

    Full Text Available During the last couple of decades, it has been demonstrated that rhizobia can associate with roots of non-legumes also without forming true nodules, and can promote their growth by using one or more of the direct or indirect mechanisms of actions. This work examines the growth and yield responses of maize to inoculation with different species of rhizobia, isolated from the root nodules of chickpea (Cicer arietinum L., lentil (Lens culinaris M. and mung bean (Vigna radiata L. in pots and fields. Twenty isolates of rhizobia were isolated from root nodules each of mung bean, lentil and chickpea and were screened under axenic conditions. On the basis of their promising performance under axenic conditions, nine most efficient isolates (three from each legume host were selected, characterized and further evaluated for their growth promoting activities by conducting pot and field experiments. Results of pot experiment revealed that maximum increase in grain yield, 1000 grain weight, N, P and K uptake (up to 47.89, 54.52, 73.46, 84.66 and 59.19% by CRI28, respectively, over un-inoculated control was produced by the isolate of Mesorhizobium ciceri. Whereas, maximum improvement in rest of the parameters was caused by the isolates of Rhizobium phaseoli (i.e. fresh biomass, straw yield and root length up to 36.30% by A18, 25.46% by S6 and 81.89% by A18, respectively over un-inoculated control. Rhizobium leguminosarum isolates came out to be the least effective among the species tested. Similarly, all the selected isolates improved the growth and yield attributing parameters in fields as well but with varying capacity compared with un-inoculated control. The selected isolates of Mesorhizobium ciceri and Rhizobium phaseoli again remained superior compared to the isolates of Rhizobium leguminosarum under field conditions. The results of this study imply that rhizobium species had potential to promote growth and yield of maize but this technology should be

  7. Rhizobium ecuadorense sp. nov., an indigenous N2-fixing symbiont of the Ecuadorian common bean (Phaseolus vulgaris L.) genetic pool.

    Science.gov (United States)

    Ribeiro, Renan Augusto; Martins, Talita Busulini; Ormeño-Orrillo, Ernesto; Marçon Delamuta, Jakeline Renata; Rogel, Marco Antonio; Martínez-Romero, Esperanza; Hungria, Mariangela

    2015-09-01

    There are two major centres of genetic diversification of common bean (Phaseolus vilgaris L.), the Mesoamerican and the Andean, and the legume is capable of establishing nitrogen-fixing symbioses with several rhizobia; Rhizobium etli seems to be the dominant species in both centres. Another genetic pool of common bean, in Peru and Ecuador, is receiving increasing attention, and studies of microsymbionts from the region can help to increase our knowledge about coevolution of this symbiosis. We have previously reported several putative new lineages from this region and here present data indicating that strains belonging to one of them, PEL4, represent a novel species. Based on 16S rRNA gene sequence phylogeny, PEL4 strains are positioned in the Rhizobium phaseoli/R. etli/Rhizobium leguminosarum clade, but show unique properties in several morphological, physiological and biochemical analyses, as well as in BOX-PCR profiles ( Rhizobium fabae. DNA-DNA hybridization ( Rhizobium ecuadorense sp. nov. The type strain is CNPSo 671(T) ( = UMR 1450(T) = PIMAMPIRS I 5(T) = LMG 27578(T)).

  8. Cloning of nod gene regions from mesquite rhizobia and bradyrhizobia and nucleotide sequence of the nodD gene from mesquite rhizobia.

    Science.gov (United States)

    Thomas, P M; Golly, K F; Virginia, R A; Zyskind, J W

    1995-09-01

    Nitrogen-fixing symbiosis between bacteria and the tree legume mesquite (Prosopis glandulosa) is important for the maintenance of many desert ecosystems. Genes essential for nodulation and for extending the host range to mesquite were isolated from cosmid libraries of Rhizobium (mesquite) sp. strain HW17b and Bradyrhizobium (mesquite) sp. strain HW10h and were shown to be closely linked. All of the cosmid clones of rhizobia that extended the host range of Rhizobium (Parasponia) sp. strain NGR234CS to mesquite also supported nodulation of a Sym- mesquite strain. The cosmid clones of bradyrhizobia that extended the host range of Rhizobium (Parasponia) sp. strain NGR234CS to mesquite were only able to confer nodulation ability in the Sym- mesquite strain if they also contained a nodD-hybridizing region. Subclones containing just the nodD genes of either genus did not extend the host range of Rhizobium (Parasponia) sp. to mesquite, indicating that the nodD gene is insufficient for mesquite nodulation. The nodD gene region is conserved among mesquite-nodulating rhizobia regardless of the soil depth from which they were collected, indicating descent from a common ancestor. In a tree of distance relationships, the NodD amino acid sequence from mesquite rhizobia clusters with homologs from symbionts that can infect both herbaceous and tree legumes, including Rhizobium tropici, Rhizobium leguminosarum bv; phaseoli, Rhizobium loti, and Bradyrhizobium japonicum.

  9. Genetic Improvement of Biological Nitrogen Fixation in Common Bean Genotypes (Phaseolus vulgaris L.

    Directory of Open Access Journals (Sweden)

    Ahmad Reza Golparvar

    2012-06-01

    Full Text Available Fifty common bean genotypes were cultivated in two separately field trials at the research station of Islamic Azad University, Khorasgan Branch during 2008-2009. The experimental design was randomized complete block. Bean seeds were inoculated by Rhizobium legominosarum biovar Phaseoli isolate L-109 in one of the experiments before sowing. The dose of Rhizobium for seed inoculation was 7 miligrams of bacteria for 1 kilogram of seed. The second experiment was control. The second experiment was analyzed in the same way as the first except for biological nitrogen fixation. The results showed definite positive and significant correlation in percentage of nitrogen fixation with some other been characters. Step-wise regression designated that total nitrogen percentage in shoot, number of nodules per plant and biomass yield accounted for 93.8% of variation expect for nitrogen fixation percent. Path analysis indicated that total nitrogen percentage in shoot, number of nodules per plant and biomass yield have direct and positive effect on nitrogen fixation index. Hence, total nitrogen percentage in shoot, number of nodules per plant and biomass yield are promising indirect selection criteria for genetic improvement of nitrogen fixation capability in common bean genotypes.

  10. Visualization of symbiotic tissue in intact root nodules of Vicia tetrasperma using GFP-marked Rhizobium leguminosarum bv. viciae

    National Research Council Canada - National Science Library

    Chovanec, P; Hovorka, O; Novák, K

    2008-01-01

    In rhizobial symbiosis with legume plant hosts, the symbiotic tissue in the root nodules of indeterminate type is localized to the basal part of the nodule where the symbiotic zones contain infected cells (IC...

  11. Extracellular polysaccharides are involved in the attachment of Azospirillum brasilense and Rhizobium leguminosarum to arbuscular mycorrhizal structures

    OpenAIRE

    V Bianciotto; Andreotti, S.; Balestrini, R; Bonfante, P.; Perotto, S

    2009-01-01

    Arbuscular mycorrhizal (AM) fungi, one of the most important component of the soil microbial community, establish physical interactions with naturally occurring and genetically modified bacterial biofertilizers and biopesticides, commonly referred to as plant growth-promoting rhizobacteria (PGPR). We have used a genetic approach to investigate the bacterial components possibly involved in the attachment of two PGPR (Azospirillum and Rhizobium) to AM roots and AM fungal structures. Mutants aff...

  12. Extracellular polysaccharides are involved in the attachment of Azospirillum brasilense and Rhizobium leguminosarum to arbuscular mycorrhizal structures

    Directory of Open Access Journals (Sweden)

    V Bianciotto

    2009-12-01

    Full Text Available Arbuscular mycorrhizal (AM fungi, one of the most important component of the soil microbial community, establish physical interactions with naturally occurring and genetically modified bacterial biofertilizers and biopesticides, commonly referred to as plant growth-promoting rhizobacteria (PGPR. We have used a genetic approach to investigate the bacterial components possibly involved in the attachment of two PGPR (Azospirillum and Rhizobium to AM roots and AM fungal structures. Mutants affected in extracellular polysaccharides (EPS have been tested in in vitro adhesion assays and shown to be strongly impaired in the attachment to both types of surfaces as well as to quartz fibers. Anchoring of rhizobacteria to AM fungal structures may have special ecological and biotechnological significance because it may facilitate colonisation of new rhizospheres by the bacteria, and may be an essential trait for the development of mixed inocula.

  13. Extracellular polysaccharides are involved in the attachment of Azospirillum brasilense and Rhizobium leguminosarum to arbuscular mycorrhizal structures.

    Science.gov (United States)

    Bianciotto, V; Andreotti, S; Balestrini, R; Bonfante, P; Perotto, S

    2001-01-01

    Arbuscular mycorrhizal (AM) fungi, one of the most important component of the soil microbial community, establish physical interactions with naturally occurring and genetically modified bacterial biofertilizers and biopesticides, commonly referred to as plant growth-promoting rhizobacteria (PGPR). We have used a genetic approach to investigate the bacterial components possibly involved in the attachment of two PGPR (Azospirillum and Rhizobium) to AM roots and AM fungal structures. Mutants affected in extracellular polysaccharides (EPS) have been tested in in vitro adhesion assays and shown to be strongly impaired in the attachment to both types of surfaces as well as to quartz fibers. Anchoring of rhizobacteria to AM fungal structures may have special ecological and biotechnological significance because it may facilitate colonisation of new rhizospheres by the bacteria, and may be an essential trait for the development of mixed inocula.

  14. Immune Responses and Protection against Experimental Brucella suis biovar 1 Challenge in Non-vaccinated or RB51-Vaccinated Cattle

    Science.gov (United States)

    Twenty Hereford heifers, approximately 9 months of age, were vaccinated with saline (control) or 2 x 10**10 CFU of Brucella abortus strain RB51 (RB51) vaccine. Immunologic responses after inoculation demonstrated significantly greater (P<0.05) antibody and proliferative responses to RB51 antigens i...

  15. First isolation, identification, phenotypic and genotypic characterization of Brucella abortus biovar 3 from dairy cattle in Tanzania

    OpenAIRE

    Mtenga, Coletha Mathew; Stokstad, Maria; Johansen, Tone Kristin Bjordal; Klevar, Siv; Mdgela, Robinson H.; Mwamengele, G L; Michel, P; L. Escobar; Fretin, D.; Godfroid, Jacques

    2015-01-01

    Background: Brucellosis is a disease of worldwide public health and economic importance. Successful control is based on knowledge of epidemiology and strains present in an area. In developing countries, most investigations are based on serological assays. This study aimed at investigating a dairy herd experiencing abortions in order to establish within-herd seroprevalence to Brucella spp., identify, characterize Brucella strains by Multiple Loci Variable Number of Tandem Repeats Analysis (MLV...

  16. Effects of ecological factors on the survival and physiology of Ralstonia solanacearum biovar 2 in agricultural drainage water

    NARCIS (Netherlands)

    Elsas, van J.D.; Kastelein, P.; Vries, de P.M.; Overbeek, van L.S.

    2001-01-01

    The fate of Ralstonia solanacearum bv. 2, the causative agent of brown rot in potato, in aquatic habitats of temperate climate regions is still poorly understood. In this study, the population dynamics and the physiological response of R. solanacearum bv. 2 were tested in sterile pure water and in a

  17. Biochemical and genetical analysis reveal a new clade of biovar 3 Dickeya spp. strains isolated from potato in Europe

    NARCIS (Netherlands)

    Slawiak, M.; Beckhoven, van J.R.C.M.; Speksnijder, A.G.C.L.; Czajkowski, R.L.; Grabe, G.; Wolf, van der J.M.

    2009-01-01

    Sixty-five potato strains of the soft rot-causing plant pathogenic bacterium Dickeya spp., and two strains from hyacinth, were characterised using biochemical assays, REP-PCR genomic finger printing, 16S rDNA and dnaX sequence analysis. These methods were compared with nineteen strains representing

  18. Influência da inoculação de rizóbios sobre a germinação e o vigor de plântulas de alface Influence of rhizobial inoculation on seedling vigor and germination of lettuce

    Directory of Open Access Journals (Sweden)

    Gilson Schlindwein

    2008-06-01

    Full Text Available Os rizóbios, conhecidos por sua capacidade de fixar N2 em associação com leguminosas, também se mostram capazes de promover o crescimento de não-leguminosas, especialmente pela produção de ácido indol-acético (AIA. Neste trabalho, objetivou-se selecionar rizóbios produtores de AIA e avaliar o efeito de diferentes concentrações deste fitormônio sobre a germinação e o desenvolvimento inicial de plântulas de alface. Foram selecionados quatro isolados de Bradyrhizobium sp. e um isolado de Rhizobium leguminosarum biovar trifolii, os quais foram crescidos por quatro dias em meio levedura-manitol enriquecido com triptofano. Após esse período, avaliou-se a produção de AIA e procedeu-se à inoculação de sementes de alface com os isolados. O isolado TV-13, de R. leguminosarum biovar trifolii produziu 171,1µg mL-1 de AIA, causando prejuízos para o desenvolvimento das plântulas de alface. Por outro lado, os isolados de Bradyrhizobium sp. produziram entre 1,2 e 3,3µg mL-1 de AIA e aumentaram o vigor das plântulas em relação ao tratamento sem inoculação com rizóbios. Para verificar se essas diferenças foram decorrentes das concentrações de AIA, foram realizados mais dois experimentos, nos quais as sementes foram embebidas em culturas de TV-13 com ou sem a presença de triptofano ou em doses crescentes de AIA sintético. O isolado TV-13 crescido na presença de triptofano causou danos progressivos sobre o desenvolvimento das plântulas de alface, o que não ocorreu na ausência de triptofano. Também foi verificado um retardo na germinação das sementes quando submetidas a altas concentrações de AIA sintético. Os resultados indicam a influência do AIA sobre os parâmetros de germinação, de modo que a inoculação de sementes de alface com rizóbios que produzem baixas quantidades de AIA é uma prática recomendável.Rhizobia are known by their ability to fix nitrogen in symbiosis with legumes, but they are also capable

  19. A common genomic framework for a diverse assembly of plasmids in the symbiotic nitrogen fixing bacteria.

    Directory of Open Access Journals (Sweden)

    Lisa C Crossman

    Full Text Available This work centres on the genomic comparisons of two closely-related nitrogen-fixing symbiotic bacteria, Rhizobium leguminosarum biovar viciae 3841 and Rhizobium etli CFN42. These strains maintain a stable genomic core that is also common to other rhizobia species plus a very variable and significant accessory component. The chromosomes are highly syntenic, whereas plasmids are related by fewer syntenic blocks and have mosaic structures. The pairs of plasmids p42f-pRL12, p42e-pRL11 and p42b-pRL9 as well large parts of p42c with pRL10 are shown to be similar, whereas the symbiotic plasmids (p42d and pRL10 are structurally unrelated and seem to follow distinct evolutionary paths. Even though purifying selection is acting on the whole genome, the accessory component is evolving more rapidly. This component is constituted largely for proteins for transport of diverse metabolites and elements of external origin. The present analysis allows us to conclude that a heterogeneous and quickly diversifying group of plasmids co-exists in a common genomic framework.

  20. Sugar-Binding Activity of Pea Lectin Expressed in White Clover Hairy Roots.

    Science.gov (United States)

    Diaz, C. L.; Logman, TJJ.; Stam, H. C.; Kijne, J. W.

    1995-01-01

    Introduction of the pea (Pisum sativum L.) lectin (PSL) gene into white clover (Trifolium repens L.) hairy roots facilitates nodulation by the nitrogen-fixing bacterium Rhizobium leguminosarum biovar viciae, which normally nodulates pea and not white clover (C.L. Diaz, L.S. Melchers, P.J.J. Hooykaas, B.J.J. Lugtenberg, and J.W. Kijne [1989] Nature 338: 579-581). Here, we show that PSL is functionally expressed in transgenic white clover hairy roots transformed with the PSL gene. PSL could be isolated from these roots by affinity chromatography. Immunoanalysis of PSL showed the presence of polypeptides corresponding to the PSL precursor and its [beta] subunits. In addition, we developed a highly sensitive localization technique based on specific binding of a glycan moiety of rat IgE to PSL. Similar to the situation in pea roots, PSL appeared to be localized on the external cell surface of elongated epidermal cells and on the tips of emerging and growing root hairs of transgenic white clover hairy roots. PSL was not observed on normal white clover roots and on hairy roots without the PSL gene. These results show that (a) in transgenic white clover hairy roots, PSL is correctly processed and targeted to root cells susceptible to rhizobial infection, and (b) like in pea roots, PSL is surface bound with at least one of its two sugar-binding sites available for (rhizobial) ligands. PMID:12228660

  1. Morphogenesis of root nodules in white clover. II. The effect of mutation in genes nod IJ of the microsymbiont upon the nodule structure

    Directory of Open Access Journals (Sweden)

    Barbara Łotocka

    2014-01-01

    Full Text Available Morphogenesis of ineffective root nodules initiated on the roots of white clover 'Astra' by the Rhizobium leguminosarum biovar. trifolii strains ANU261 (Tn5 insertion in nod 1 gene and ANU262 (Tn5 insertion in nod J gene was investigated. Following changes were observed, as compared to the wild-type nodulation: the exaggerated, not delayed reaction of root hairs; the delay in nodulation with the number of nodules the same as in plants inoculated with a wild strain; the formation and organization of the nodule primordium not changed in comparison with the wild-type nodules; infection threads abnormally branched and diffusing with bacteria deprived of light zone and enriched with storage material; infected cells of bacteroidal tissue abnormally strongly osmiophilic and only slightly vacuolated; symbiosomes with very narrowed peribacteroidal space, subject to premature degradation; abnormal accumulation of starch in the nodule tissues; nodule development blocked at the stage of laterally situated meristem and single nodule bundle; inhibition of divisions in the meristem and vacuolation of its cells; the appearance of single cells with colonies of saprophytic rhizobia embedded in the fibrillar matrix in the old, degraded regions of the bacteroidal tissue.

  2. Site-specific distribution and competitive ability of indigenous bean-nodulating rhizobia isolated from organic fields in Minnesota.

    Science.gov (United States)

    Wongphatcharachai, Manoosak; Wang, Ping; Staley, Christopher; Chun, Chan Lan; Ferguson, John A; Moncada, Kristine M; Sheaffer, Craig C; Sadowsky, Michael J

    2015-11-20

    Organic dry bean production systems have received increasing interest in many regions of the US, including Minnesota. Thus, improving biological N2 fixation would be highly beneficial for organic crop production. To date, only limited work has been done to select efficient N2-fixing rhizobia for organic dry bean production. In this study, soil samples from 25 organic fields in Minnesota, with a previous cropping history of dry beans, soybeans or both, were collected during May to July 2012. Genetic diversity of indigenous dry bean-rhizobia (511 isolates) was determined by using horizontal, fluorophore-enhanced, repetitive, extragenic, and palindromic-PCR (HFERP) DNA fingerprinting and isolates were classified as belonging to 58 different genotypes. The more abundant rhizobia isolated from bean nodules comprised 35.6% of the population. None of the isolates were identical to commonly-used commercial strains used in the U.S., including Rhizobium tropici CIAT899. Seventeen predominant genotypes were shown to represent two main species, Rhizobium leguminosarum bv. phaseoli (67.1%) and Rhizobium etli (30.2%). One of the indigenous strains, orgK9, displayed efficient N2-fixation and competitive ability relative to the commercial strains tested. The lack of large numbers of indigenous dry bean-rhizobia at most study sites will be useful to avoid competition problems between inoculant strains and indigenous rhizobia. This will allow inoculation with highly effective N2-fixing rhizobia, thus resulting in improved crop productivity. Our results highlight the existence of site-specific rhizobial genotypes in different organic fields and identify strains that may prove useful as novel inoculants for organic dry bean production systems. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Variation of clonal, mesquite-associated rhizobial and bradyrhizobial populations from surface and deep soils by symbiotic gene region restriction fragment length polymorphism and plasmid profile analysis.

    Science.gov (United States)

    Thomas, P M; Golly, K F; Zyskind, J W; Virginia, R A

    1994-04-01

    Genetic characteristics of 14 Rhizobium and 9 Bradyrhizobium mesquite (Prosopis glandulosa)-nodulating strains isolated from surface (0- to 0.5-m) and deep (4- to 6-m) rooting zones were determined in order to examine the hypothesis that surface- and deep-soil symbiont populations were related but had become genetically distinct during adaptation to contrasting soil conditions. To examine genetic diversity, Southern blots of PstI-digested genomic DNA were sequentially hybridized with the nodDABC region of Rhizobium meliloti, the Klebsiella pneumoniae nifHDK region encoding nitrogenase structural genes, and the chromosome-localized ndvB region of R. meliloti. Plasmid profile and host plant nodulation assays were also made. Isolates from mesquite nodulated beans and cowpeas but not alfalfa, clover, or soybeans. Mesquite was nodulated by diverse species of symbionts (R. meliloti, Rhizobium leguminosarum bv. phaseoli, and Parasponia bradyrhizobia). There were no differences within the groups of mesquite-associated rhizobia or bradyrhizobia in cross-inoculation response. The ndvB hybridization results showed the greatest genetic diversity among rhizobial strains. The pattern of ndvB-hybridizing fragments suggested that surface and deep strains were clonally related, but groups of related strains from each soil depth could be distinguished. Less variation was found with nifHDK and nodDABC probes. Large plasmids (>1,500 kb) were observed in all rhizobia and some bradyrhizobia. Profiles of plasmids of less than 1,000 kb were related to the soil depth and the genus of the symbiont. We suggest that interacting selection pressures for symbiotic competence and free-living survival, coupled with soil conditions that restrict genetic exchange between surface and deep-soil populations, led to the observed patterns of genetic diversity.

  4. The lipopolysaccharide lipid-a long chain fatty acid is important for rhizobium leguminosarum growth and stress adaptation in free-living and nodule environments

    Science.gov (United States)

    Rhizobium bacteria live in soil and plant environments, are capable of inducing symbiotic nodules on legumes, invade these nodules, and develop into bacteroids that fix atmospheric nitrogen into ammonium. Lipopolysaccharide (LPS) is anchored in the bacterial outer membrane through a specialized lipi...

  5. Local genetic structure and worldwide phylogenetic position of symbiotic Rhizobium leguminosarum strains associated with a traditional cultivated crop, Vicia ervilia, from Northern Morocco

    OpenAIRE

    Sbabou, L.; Regragui, A.; Filali-Maltouf, A.; Ater, M.; Béna, Gilles

    2016-01-01

    A total of 212 symbiotic bacteria were isolated from nodules of Vicia ervilia, a traditional crop cultivated in Northern Morocco. The isolates were recovered from 10 different sites, trapped each time with the local cultivar grown in the same field. Four loci were sequenced in order to characterize the isolates, including two housekeeping genes (recA and glnII), one plasmidic symbiotic gene (nodC) and one locus from another plasmid (prL11). In several isolates, two different copies of glnII w...

  6. Local genetic structure and worldwide phylogenetic position of symbiotic Rhizobium leguminosarum strains associated with a traditional cultivated crop, Vicia ervilia, from Northern Morocco.

    Science.gov (United States)

    Sbabou, Laila; Regragui, Assmaa; Filali-Maltouf, Abdelkarim; Ater, Mohammed; Béna, Gilles

    2016-09-01

    A total of 212 symbiotic bacteria were isolated from nodules of Vicia ervilia, a traditional crop cultivated in Northern Morocco. The isolates were recovered from 10 different sites, trapped each time with the local cultivar grown in the same field. Four loci were sequenced in order to characterize the isolates, including two housekeeping genes (recA and glnII), one plasmidic symbiotic gene (nodC) and one locus from another plasmid (prL11). In several isolates, two different copies of glnII were detected and sequenced, suggesting a unique duplication event, which has never been reported previously. There was no correlation between the genetic differentiation among cultivars and among bacteria, showing that the evolution of the bacterial population was independent, at least partially, from the host plant. By placing the haplotypes in a wide-ranging phylogenetic reconstruction, it was shown that the diversity detected in Morocco was spread throughout the different clades detected worldwide. The differentiation between areas relied on frequency variations of haplotypes rather than a presence/absence pattern. This finding raises new questions concerning bacterial genetic resource preservation, and confirms the old tenet "everything is everywhere but the environment selects". Copyright © 2016 Elsevier GmbH. All rights reserved.

  7. Incidence of Agrobacterium tumefaciens biovar 1 in and on ‘Paradox’ (Juglans hindsii x Juglans regia) walnut seed collected from commercial nurseries

    Science.gov (United States)

    The walnut rootstock Paradox (Juglans hindsii (Jeps) Rehder x J. regia L.) is susceptible to Agrobacterium tumefaciens (7) which often results in a high incidence of crown gall in nursery or walnut production orchards. Though A. tumefaciens is susceptible to the commonly used preplant soil fumigant...

  8. Historical report: first isolation of Vibrio Cholera serogroup 01 biovar El Tor serovar inaba during the cholerae epidemic in Peru - 1991

    OpenAIRE

    Bravo Cruz, Nora; Facultad de Ciencias Naturales y Matemática, Universidad Nacional Federico Villarreal. Bióloga. Exjefa del Departamento de Bacteriología, Centro Nacional de Salud Pública, Instituto Nacional de Salud.; Guillén, Alfredo; Facultad de Tecnología Médica, Universidad Nacional Federico Villarreal. Clínica San Borja. Médico Microbiólogo.

    2011-01-01

    20 years ago, a new diarrheal disease was introduced in Peru and the Enteropathogens Reference Laboratory of the Instituto Nacional de Salud had an outstanding role in the isolation and rapid and timely identification of Vibrio cholerae. Cholera had not been seen before, but during the last week of January 1991 an outbreak of acute diarrhea was detected, presenting intense dehydration and some deaths. The epidemic affected, in the beginning, many locations of the peruvian coast. Some work...

  9. Nucleotide Sequence and Analysis of an orotate transporter-containing plasmid isolated from the Lactococcus lactis ssp. lactis biovar diacetylactis strain DB0410

    DEFF Research Database (Denmark)

    Defoor, Els Marie Celine; Martinussen, Jan

    determined. Fifteen open reading frames (ORFs) were encountered of which three insertion-sequence (IS) elements identified as two IS946 and one IS982. Two ORFs are incomplete due to the insertion of an IS element in their carboxy terminal end. Homologs for four ORFs were found on the IL1403 sequence: the cop...... and molecular cloning, we identified the open reading frames on pDBORO necessary for the utilization of orotate as the sole pyrimidine source. Surprisingly, homologs are found on the Lactococcus lactis IL1403 and MG1363 chromosomes despite the fact that they are resistant towards fluoroorotate....

  10. The pan-genome of the animal pathogen Corynebacterium pseudotuberculosis reveals differences in genome plasticity between the biovar ovis and equi strains

    DEFF Research Database (Denmark)

    Soares, Siomar C; Silva, Artur; Trost, Eva

    2013-01-01

    Corynebacterium pseudotuberculosis is a facultative intracellular pathogen and the causative agent of several infectious and contagious chronic diseases, including caseous lymphadenitis, ulcerative lymphangitis, mastitis, and edematous skin disease, in a broad spectrum of hosts. In addition, Cory...

  11. Downward Vascular Translocation of a Green Fluorescent Protein-Tagged Strain of Dickeya sp. (Biovar 3) from Stem and Leaf Inoculation Sites on Potato.

    NARCIS (Netherlands)

    Czajkowski, R.L.; Boer, de W.; Veen, van J.A.; Wolf, van der J.M.

    2010-01-01

    Translocation of a green fluorescent protein (GFP)-tagged Dickeya sp. from stems or from leaves to underground parts of potato plants was studied in greenhouse experiments. Thirty days after stem inoculation, 90% of plants expressed symptoms at the stem base and 95% of plants showed browning of inte

  12. The cyclic AMP receptor protein, CRP, is required for both virulence and expression of the minimal CRP regulon in Yersinia pestis biovar microtus.

    Science.gov (United States)

    Zhan, Lingjun; Han, Yanping; Yang, Lei; Geng, Jing; Li, Yingli; Gao, He; Guo, Zhaobiao; Fan, Wei; Li, Gang; Zhang, Lianfeng; Qin, Chuan; Zhou, Dongsheng; Yang, Ruifu

    2008-11-01

    The cyclic AMP receptor protein (CRP) is a bacterial regulator that controls more than 100 promoters, including those involved in catabolite repression. In the present study, a null deletion of the crp gene was constructed for Yersinia pestis bv. microtus strain 201. Microarray expression analysis disclosed that at least 6% of Y. pestis genes were affected by this mutation. Further reverse transcription-PCR and electrophoretic mobility shift assay analyses disclosed a set of 37 genes or putative operons to be the direct targets of CRP, and thus they constitute the minimal CRP regulon in Y. pestis. Subsequent primer extension and DNase I footprinting assays mapped transcriptional start sites, core promoter elements, and CRP binding sites within the DNA regions upstream of pla and pst, revealing positive and direct control of these two laterally acquired plasmid genes by CRP. The crp disruption affected both in vitro and in vivo growth of the mutant and led to a >15,000-fold loss of virulence after subcutaneous infection but a pestis and, particularly, is more important for infection by subcutaneous inoculation. It can further be concluded that the reduced in vivo growth phenotype of the crp mutant should contribute, at least partially, to its attenuation of virulence by both routes of infection. Consistent with a previous study of Y. pestis bv. medievalis, lacZ reporter fusion analysis indicated that the crp deletion resulted in the almost absolute loss of pla promoter activity. The plasminogen activator encoded by pla was previously shown to specifically promote Y. pestis dissemination from peripheral infection routes (subcutaneous infection [flea bite] or inhalation). The above evidence supports the notion that in addition to the reduced in vivo growth phenotype, the defect of pla expression in the crp mutant will greatly contribute to the huge loss of virulence of this mutant strain in subcutaneous infection.

  13. 菜豆根瘤菌对土壤无机磷的活化释放作用%EFFECT OF RHIZOBIUM PHASEOLI ON MOBILIZATION AND RELEASE OF INORGANIC PHOSPHORUS IN SOIL

    Institute of Scientific and Technical Information of China (English)

    张亮; 黄建国

    2012-01-01

    Seven strains of Rhizobium sp. were cultured in liquid mediums using soil as the sole source for phosphorus to investigate effect of the strains on mobilization and release of phosphorus in soil. The control treatment was set in the same way except inoculation of Rhizobia. Results suggest that the bacteria released a large amount of hydrogen ions, thus making the concentration of the ions multiplied by at least 20 times, which resulted in a significant decrease in pH of the solution. Different strains of Rhizobia released different types and amounts of organic acids, including oxalic acid, malic acid, succinic acid, formic acid, acetic acid, citric acid and lactic acid. However, most of the strains exuded acetic acid. The treatments were significantly higher than the control in total phosphorus in the liquid culture mediums, while the total inorganic phosphorus in the soil immersed in the liquid behaved otherwise. Taking into account the soil being the sole phosphorus source, it could be concluded that Rhizobia could promote mobilization and release of inorganic phosphorus from the soil. Correlation analysis shows that total phosphorous was extremely positively related to pH of the liquid ( r = 0. 893 , n = 8) , suggesting that the secretion of hydrogen ions from the bacteria is one of the causes for dissolution of inorganic phosphorus in soil. Inoculation of Rhizobia reduced occluded phosphorus in the soil remarkably, and also Al-P, Fe-P and Ca-P but to an extent varying with the stains of Rhizobia, which might be attributed to the different amounts and types of organic acids they could secret. The phenomenon of Rhizobia releasing hydrogen ions and a variety of organic acids suggests that inorganic phosphorus in the soil is mobilized in a number of ways, which demonstrates that inoculation of Rhizobia may help legume crops make use of various forms of unavailable phosphorus in the soil, thus making them adapted to different soils low in phosphorus.%以土壤为磷源,通过液体培养研究了7株菜豆根瘤菌(Rhizobium sp.)对土壤磷的利用.结果表明,菜豆根瘤菌能释放大量的氢离子,使液体培养基的pH大幅度降低,氢离子的浓度至少提高20倍以上.根瘤菌分泌有机酸的种类与数量因菌株不同而异,这些有机酸包括甲酸、乙酸、草酸、丁二酸、柠檬酸、苹果酸和乳酸等,大部分根瘤菌能分泌乙酸.在接种根瘤菌的液体培养基中,全磷含量显著高于不接种的液体培养基,土壤无机磷总量则显著降低.由于土壤是培养基磷的唯一来源,故根瘤菌可促进土壤无机磷的溶解释放.相关分析表明,培养基的pH与土壤无机磷总量呈极显著正相关(r=0.893**,n=8),说明根瘤菌分泌的氢离子可能是溶解土壤无机磷的原因之一.接种根瘤菌显著降低土壤闭蓄态磷,土壤中的铁磷、铝磷和钙磷因菌株不同而降低,其原因可能与有机酸分泌的数量和种类有关.根瘤菌既能释放氢离子又可分泌多种有机酸的现象表明其活化土壤无机磷的方式具有多样性,可能有益于豆科植物利用不同形态的难溶性磷,使之适应各种不同的低磷土壤.

  14. Application of a lux-based bioassay to assess soil toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Paton, G.I. [Macaulay Land Use Research Inst., Aberdeen (United Kingdom)]|[Univ. of Aberdeen (United Kingdom); Campbell, C.D. [Macaulay Land Use Research Inst., Aberdeen (United Kingdom); Rattray, E.A.S.; Glover, L.A.; Killham, K. [Univ. of Aberdeen (United Kingdom)

    1995-12-31

    The expression of prokaryotic bioluminescence is linked with cell metabolism and accordingly bioassays have been developed using naturally bioluminescent bacteria to assess ecotoxicity. Advances in biotechnology have allowed the isolation of the lux genes (responsible for bioluminescence) from marine organisms and their insertion into terrestrial bacteria. This has enabled the use of ecologically relevant bacteria to assess toxicity by measuring bioluminescence response in the presence of toxins. The lux genes were inserted into Pseudomonas fluorescens and Rhizobium leguminosarum biovar trifolii as a multi-copy plasmid and also integrated into the chromosome. It was found that in aqueous solutions the plasmid constructs were more sensitive than the chromosomal constructs to a range of toxins. The order of toxicity for Ps. fluorescens was Zn = Cu > Cd > Ni > Cr > DCP and for R. trifolii Zn > Cu > Cd > DCP > Cr. The lux based bioassays were more reproducible and sensitive than ATP and dehydrogenase assays and offered greater sensitivity than Photobacterium phosphoreum assays to assess toxicity of inorganic pollutants. Extracts from 4 soil types were spiked with a range of toxins and when EC{sub 50} values were determined it was shown that toxicity was related to soil characteristics. This enabled the assay to be used to assess the Lee Valley soil experiment which represents an important international study of the effect of the application of contaminated sewage to land. High metal application rates had been shown to have serious implications for soil ecology. Chemical analysis, carried out 26 years after sewage addition confirmed that soil extracts still had increased metal concentrations. The lux-based bioassays, which proved to be rapid, reproducible and sensitive confirmed that the metals were still biologically available and hence toxic.

  15. Molecular typing of Brucella species isolates from Human and livestock bloods in Isfahan province

    Directory of Open Access Journals (Sweden)

    Ebtehaj Pishva

    2015-01-01

    Conclusion: Our findings confirm abundance of B. melitensis, particularly biovar 1 in human and sheep are identical but B. abortus biovar 3 as the etiological agent of cattle brucellosis most frequently isolated in the Isfahan area.

  16. Reporte histórico: Primer Aislamiento de Vibrio cholera serogrupo O1 biovar El Tor serovar Inaba durante la epidemia de cólera en el Perú ‑ 1991 Historical report: first isolation of Vibrio cholera serogroup O1 biovar El Tor serovar Inaba during the cholerae epidemic in Perú ‑ 1991

    OpenAIRE

    Nora Bravo Cruz; Alfredo Guillén

    2011-01-01

    Hace 20 años apareció una enfermedad diarreica nueva en el Perú y el Laboratorio de Referencia de Enteropatógenos del Instituto Nacional de Salud, cumplió una labor destacada en el aislamiento e identificación rápida y oportuna del Vibrio cholerae. La enfermedad del cólera no se había presentado anteriormente, pero en la última semana de enero de 1991 se detectó un brote epidémico de diarrea aguda con deshidratación intensa y algunos casos de fallecidos. La epidemia afectó, al comienzo, varia...

  17. QTL analysis for Fusarium root rot resistance in snap bean under greenhouse conditions

    Science.gov (United States)

    Fusarium root rot (FRR), caused by Fusarium solani f. sp. phaseoli (syn.F. phaseoli T. Aoki & O’Donnell, F. cuneirostrum O’Donnell & T. Aoki), is considered as one of the most economically important and widespread fungal diseases of common bean (1). Progress in breeding for FRR resistance has been h...

  18. Antioxidation and symbiotic nitrogen fixation phenotype of ohrB gene in Rhizobium leguminosarum%豌豆根瘤菌ohrB基因的抗氧化和共生固氮表型

    Institute of Scientific and Technical Information of China (English)

    田梦洋; 何冬兰; 李晓华; 周艳琳; 曾小波; 程国军

    2016-01-01

    采用基因敲除构建豌豆根瘤菌ohrB基因突变株,研究突变株的抗氧化和共生固氮表型.结果表明:ohrB基因不影响菌株在自生培养条件下的生长能力,但对氢过氧化枯烯(cumene hydroperoxyde,CuOOH)、过氧化氢(H2O2)、次氯酸钠(NaClO)等氧化物敏感,且在CuOOH胁迫下,相比野生型菌株,突变株的存活率显著下降.荧光定量RT-PCR结果显示,豌豆根瘤菌ohrB基因表达不受H2O2诱导,且ohrB基因的缺失对其他抗氧化基因的表达没有影响.共生实验表明,ohrB基因对根瘤菌共生固氮能力及根际定殖能力没有影响,但在7d瘤龄的豌豆根瘤类菌体中表达水平显著提高,并对根瘤菌结瘤能力有影响.ohrB基因虽对豌豆根瘤菌的自生生长、共生固氮、根圈定殖没有影响,但在抗氧化及竞争结瘤中发挥重要作用.

  19. Identificación y caracterización funcional de sistemas génicos implicados en la homeostasis de níquel en Rhizobium leguminosarum bv. viciae

    OpenAIRE

    2010-01-01

    La homeostasis de metales como níquel, cobalto, cobre o zinc es un proceso delicado en procariotas. Estos metales de transición son, por un lado imprescindibles para el mantenimiento del metabolismo celular, pero por otro muy tóxicos a elevadas concentraciones. Por este motivo, los microorganismos han desarrollado mecanismos para regular su concentración intracelular, tales como bombas de flujo de metales, secuestradores intra y extracelulares o enzimas detoxificadoras.

  20. Draft Genome Sequences of Brucella suis Biovar 4 Strain NCTC 10385, Brucella ceti Strain NCTC 12891T, Brucella inopinata Strain CAMP 6436T, and Brucella neotomae Strain ATCC 23459T

    National Research Council Canada - National Science Library

    Wahab, Tara; Ferrari, Sevinc; Lindberg, Martina; Bäckman, Stina; Kaden, Rene

    2014-01-01

    With the aim of developing quantitative PCR methods for the detection and differentiation of Brucella species, the genomes of Brucella ceti, Brucella inopinata, Brucella netotomae, and Brucella suis...

  1. NCBI nr-aa BLAST: CBRC-MLUC-01-0812 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-MLUC-01-0812 ref|YP_002974466.1| cobalt transport protein [Rhizobium leguminos...arum bv. trifolii WSM1325] gb|ACS54927.1| cobalt transport protein [Rhizobium leguminosarum bv. trifolii WSM1325] YP_002974466.1 4.1 32% ...

  2. NCBI nr-aa BLAST: CBRC-BTAU-01-1670 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-BTAU-01-1670 ref|YP_768013.1| probable peptidase/protease [Rhizobium leguminos...arum bv. viciae 3841] emb|CAK07913.1| probable peptidase/protease [Rhizobium leguminosarum bv. viciae 3841] YP_768013.1 2.3 25% ...

  3. NCBI nr-aa BLAST: CBRC-LAFR-01-1888 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-LAFR-01-1888 ref|YP_770319.1| hypothetical protein pRL100017 [Rhizobium legumi...nosarum bv. viciae 3841] emb|CAK10242.1| conserved hypothetical protein [Rhizobium leguminosarum bv. viciae 3841] YP_770319.1 0.49 34% ...

  4. Complete Genome Sequences of Three Rhizobium gallicum Symbionts Associated with Common Bean (Phaseolus vulgaris)

    Science.gov (United States)

    Bustos, Patricia; Santamaría, Rosa Isela; Pérez-Carrascal, Olga María; Acosta, José Luis; Lozano, Luis; Juárez, Soledad; Martínez-Romero, Esperanza; Cevallos, Miguel Ángel; Romero, David; Dávila, Guillermo; Vinuesa, Pablo; Miranda, Fabiola; Ormeño, Ernesto

    2017-01-01

    ABSTRACT The whole-genome sequences of three strains of Rhizobium gallicum reported here support the concept that the distinct nodulation host ranges displayed by the symbiovars gallicum and phaseoli can be largely explained by different symbiotic plasmids. PMID:28302777

  5. Genetic variability of Yersinia pestis isolates as predicted by PCR-based IS100 genotyping and analysis of structural genes encoding glycerol-3-phosphate dehydrogenase (glpD).

    Science.gov (United States)

    Motin, Vladimir L; Georgescu, Anca M; Elliott, Jeffrey M; Hu, Ping; Worsham, Patricia L; Ott, Linda L; Slezak, Tomas R; Sokhansanj, Bahrad A; Regala, Warren M; Brubaker, Robert R; Garcia, Emilio

    2002-02-01

    A PCR-based genotyping system that detects divergence of IS100 locations within the Yersinia pestis genome was used to characterize a large collection of isolates of different biovars and geographical origins. Using sequences derived from the glycerol-negative biovar orientalis strain CO92, a set of 27 locus-specific primers was designed to amplify fragments between the end of IS100 and its neighboring gene. Geographically diverse members of the orientalis biovar formed a homogeneous group with identical genotype with the exception of strains isolated in Indochina. In contrast, strains belonging to the glycerol-positive biovar antiqua showed a variety of fingerprinting profiles. Moreover, strains of the biovar medievalis (also glycerol positive) clustered together with the antiqua isolates originated from Southeast Asia, suggesting their close phylogenetic relationships. Interestingly, a Manchurian biovar antiqua strain Nicholisk 51 displayed a genotyping pattern typical of biovar orientalis isolates. Analysis of the glycerol pathway in Y. pestis suggested that a 93-bp deletion within the glpD gene encoding aerobic glycerol-3-phosphate dehydrogenase might account for the glycerol-negative phenotype of the orientalis biovar. The glpD gene of strain Nicholisk 51 did not possess this deletion, although it contained two nucleotide substitutions characteristic of the glpD version found exclusively in biovar orientalis strains. To account for this close relationship between biovar orientalis strains and the antiqua Nicholisk 51 isolate, we postulate that the latter represents a variant of this biovar with restored ability to ferment glycerol. The fact that such a genetic lesion might be repaired as part of the natural evolutionary process suggests the existence of genetic exchange between different Yersinia strains in nature. The relevance of this observation on the emergence of epidemic Y. pestis strains is discussed.

  6. Disease: H00297 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available ue of Justinian in the sixth century, the Black Death in the fourteenth century, and the Third...determined for the strains responsible for these epidemics. Infectious disease Yersinia pestis CO92 (biovar Orientalis) [GN:ype] (Thi...rd Pandemic) Yersinia pestis KIM (biovar Mediaevalis) [G

  7. Molecular diagnosis of lymphogranuloma venereum in patients with genital ulcer disease.

    NARCIS (Netherlands)

    Sturm, P.D.J.; Moodley, P.; Govender, K.; Bohlken, L.; Mali, T. van; Sturm, A.W.

    2005-01-01

    The detection of herpes, chancroid, and syphilis in genital ulcers is done by PCR. This is not so for lymphogranuloma venereum (LGV). We report on the use of a PCR with digestion that differentiates the LGV biovar from the trachoma biovar. Our findings suggest that the clinical description of LGV in

  8. Recommendations of the Subcommittee on the taxonomy of Campylobacter and related bacteria

    DEFF Research Database (Denmark)

    Vandamme, P.; On, S.L.W.

    2001-01-01

    therefore discourages the use of the name C. hyoilei. (ii) The revised infrasubspecific nomenclature of Campylobacter sputorum is endorsed. C. sputorum is subdivided into C. sputorum biovar sputorum (characterized by the absence of catalase and urease activity); C. sputorum biovar faecalis (characterized...

  9. NCBI nr-aa BLAST: CBRC-MDOM-03-0025 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-MDOM-03-0025 ref|ZP_02220736.1| hypothetical protein YpF1991016_1335 [Yersinia pestis biovar Oriental...is str. F1991016] gb|EDR40255.1| hypothetical protein YpF1991016_1335 [Yersinia pestis biovar Orientalis str. F1991016] ZP_02220736.1 0.018 30% ...

  10. Green fluorescent protein labeling of food pathogens Yersinia enterocolitica and Yersinia pseudotuberculosis.

    Science.gov (United States)

    Gensberger, Eva Theres; Kostić, Tanja

    2017-01-01

    Labeling of bacteria with marker genes, such as green fluorescent protein, is a useful and practicable tool for tracking and enumerating bacterial cells in a complex environment e.g. discrimination from the indigenous background population. In this study, novel TurboGFP prokaryotic expression vector was utilized for labeling of Yersinia species. Y. enterocolitica biovar 1A, biovar 2, biovar 4 and Y. pseudotuberculosis were successfully transformed with the vector and expressed bright green fluorescence that was even detectable visually by eye. No adverse effects were observed in growth behavior of the labeled strains compared to wild type (parental) strains and vector maintenance for longer time periods could be achieved for Y. enterocolitica biovar 1A, Y. enterocolitica biovar 2 and Y. pseudotuberculosis.

  11. Comparison of three typing assays for nicotinamide adenine dinucleotide-independent Actinobacillus pleuropneumoniae.

    Science.gov (United States)

    Maldonado, Jaime; Blanco, Mónica; Martínez, Eva; Navas, Jesús

    2011-07-01

    Three tests for typing clinical isolates of Actinobacillus pleuropneumoniae biovar 2 were compared: 1) standard coagglutination with type-specific antisera against serovars 1-12 of biovar 1 of A. pleuropneumoniae; 2) a previously described polymerase chain reaction system for detecting the apx genes encoding the ApxI, ApxII, and ApxIII toxins in A. pleuropneumoniae; and 3) a restriction fragment length polymorphism analysis of the transferrin-binding protein B gene. The panel of strains tested included 112 field isolates of biovar 2 recovered from pigs between 1979 and 2007 in Italy and Spain, and reference strains for all described serovars of both biovars. The values of Simpson index of diversity obtained for the 3 methods were 0.68, 0.20, and 0.60, respectively. Coagglutination assays identified the field isolates as belonging to serovars 2 (9 strains), 4 (13 strains), 7 (61 strains), 9 (17 strains), and 11 (1 strain). Eleven strains were not typeable, and cross-reactivity was observed between serovars 2 and 4, 4 and 7, and 9 and 11. Isolates of A. pleuropneumoniae biovar 2 displayed 2 apx patterns: ApxII(+) (94 strains) and ApxI(+)/ApxII(+) (18 strains). The restriction fragment length polymorphism analysis assigned the strains tested to 3 different patterns. This method distinguished between biovar 2 reference strains and field strains that could not be identified by other methods, thus constituting a useful complementary test for the typing of A. pleuropneumoniae biovar 2.

  12. Characterization of some Brucella species from Zimbabwe by biochemical profiling and AMOS-PCR

    Directory of Open Access Journals (Sweden)

    Skjerve Eystein

    2009-12-01

    Full Text Available Abstract Background Bovine brucellosis caused by Brucella abortus is endemic in most large commercial and smallholder cattle farms of Zimbabwe, while brucellosis in other domestic animals is rare. The diagnosis of brucellosis is mainly accomplished using serological tests. However, some Brucella spp. have been isolated from clinical cases in the field and kept in culture collection but their biochemical profiles were not documented. We report biochemical profiling and AMOS-PCR characterization of some of these field isolates of Brucella originating from both commercial and smallholder cattle farming sectors of Zimbabwe. Findings Fourteen isolates of Brucella from culture collection were typed using biochemical profiles, agglutination by monospecific antisera, susceptibility to Brucella-specific bacteriophages and by AMOS-PCR that amplifies species- specific IS711. The results of the biochemical profiles for B. abortus biovar 1 (11 isolates and biovar 2 (2 isolates were consistent with those of reference strains. A single isolate from a goat originating from a smallholder mixed animal farm was identified as B. melitensis biovar 1. The AMOS-PCR produced DNA products of sizes 498 bp and 731 bp for B. abortus (biovar 1 and 2 and B. melitensis biovar 1, respectively. Conclusion We concluded that the biochemical profiles and AMOS-PCR characterization were consistent with their respective species and biovars. B. abortus biovar 1 is likely to be the predominant cause of brucellosis in both commercial and smallholder cattle farms in Zimbabwe.

  13. Contributo para a melhoria de solos marginais destinados a pastagens pela aplicação de lama residual urbana, sem riscos ambientais Contribution to the improvement of degraded soils under pastures through sewage sludge application, without environmental risks

    Directory of Open Access Journals (Sweden)

    M. G. Serrão

    2009-01-01

    Full Text Available A aplicação de lamas residuais urbanas (LRU aos solos destinados a pastagens, ainda escassamente utilizada no País, contribui, com frequência, para melhorar os níveis de matéria orgânica (M.O. e de alguns nutrientes das plantas e para diminuir o risco de erosão, pelo aumento da cobertura vegetal. Todavia, a presença eventual de níveis elevados de metais pesados, compostos orgânicos poluentes e organismos patogénicos nas LRU condiciona a dose a aplicar e torna imprescindível o controlo desses factores nos solos aos quais foram incorporadas. Também o teor elevado de azoto que por vezes contêm pode inibir a actividade simbiótica do rizóbio, prejudicando a sobrevivência das leguminosas na pastagem. Neste trabalho, examinaram-se a produção de matéria seca, a composição florística e o teor de cobre (Cu na biomassa vegetal, em dois anos consecutivos de um ensaio com uma mistura pratense semeada para cortes sucessivos, instalado, no Outono de 2001, num Luvissolo Háplico de baixa fertilidade, em Mértola, ao qual foi aplicado LRU secundária proveniente da ETAR de Évora, com um elevado teor de Cu. No mesmo período, apreciou-se a evolução, na camada superficial do solo, dos teores de M.O., de alguns macronutrientes e do Cu extraível por água régia. Avaliouse, ainda, a grandeza da população rizobiana que nodula o trevo (Rhizobium leguminosarum biovar trifolii e procedeu-se à prospecção de indicadores de contaminação fecal (bactérias coliformes e enterococos. No ano seguinte à aplicação da LRU, examinou-se a evolução, no solo, de 11 compostos bifenilospoliclorados (PCBs, 13 pesticidas organoclorados e 16 hidrocarbonetos aromáticos polinucleares (PAHs. O ensaio, de blocos casualizados, teve como modalidades três níveis de LRU (L 0 = 0, L1 = 12 e L2 = 24 t/ha e duas repetições. A mistura semeada incluiu azevém anual, panasco, cinco espécies de trevo, bisserula e serradela. Além de muito maiores produ

  14. 76 FR 65166 - International Sanitary and Phytosanitary Standard-Setting Activities

    Science.gov (United States)

    2011-10-20

    .... Chapter X.X.X, Animal Welfare and Broiler Chicken Production. (This proposed chapter that focuses on... Panel The panel will develop a NAPPO diagnostic protocol for Ralstonia solanacearum Race 3 Biovar 2...

  15. Establishment of streptococci in the upper respiratory tract: longitudinal changes in the mouth and nasopharynx up to 2 years of age

    DEFF Research Database (Denmark)

    Könönen, E; Jousimies-Somer, H; Bryk, A;

    2002-01-01

    As part of a series of longitudinal studies on the development of the indigenous microflora of the upper respiratory tract, the establishment of streptococci in the oral cavity and nasopharynx and IgA1 protease production by the early streptococcal flora was examined in 50 healthy Caucasian infants...... in the nasopharynx. S. mitis biovar 1 and S. pneumoniae, a traditional respiratory pathogen, were the principal streptococcal species among nasopharyngeal isolates. IgA1 protease production by early streptococci was common in infancy. Among the oral streptococcal microflora, S. mitis biovar 1 (especially during...... at the ages of 2, 6, 12, 18 and 24 months. In the oral cavity, streptococci were found in all infants on every sampling occasion, Streptococcus mitis biovar 1 being the main finding in each age group. S. salivarius and S. mitis biovar 2 reached their highest prevalence during the first year of life, whereas...

  16. Genotyping, Orientalis-like Yersinia pestis, and plague pandemics.

    Science.gov (United States)

    Drancourt, Michel; Roux, Véronique; Dang, La Vu; Tran-Hung, Lam; Castex, Dominique; Chenal-Francisque, Viviane; Ogata, Hiroyuki; Fournier, Pierre-Edouard; Crubézy, Eric; Raoult, Didier

    2004-09-01

    Three pandemics have been attributed to plague in the last 1,500 years. Yersinia pestis caused the third, and its DNA was found in human remains from the second. The Antiqua biovar of Y. pestis may have caused the first pandemic; the other two biovars, Medievalis and Orientalis, may have caused the second and third pandemics, respectively. To test this hypothesis, we designed an original genotyping system based on intergenic spacer sequencing called multiple spacer typing (MST). We found that MST differentiated every biovar in a collection of 36 Y. pestis isolates representative of the three biovars. When MST was applied to dental pulp collected from remains of eight persons who likely died in the first and second pandemics, this system identified original sequences that matched those of Y. pestis Orientalis. These data indicate that Y. pestis caused cases of Justinian plague. The two historical plague pandemics were likely caused by Orientalis-like strains.

  17. Molecular typing of Brucella species isolates from livestock and human.

    Science.gov (United States)

    Nagalingam, Mohandoss; Shome, Rajeswari; Balamurugan, Vinayagamurthy; Shome, Bibek Ranjan; NarayanaRao, Krishnamsetty; Vivekananda; Isloor, Shrikrishna; Prabhudas, Krishnamsetty

    2012-01-01

    Although host specificity has been observed in different species of Brucella, crossing the animal host boundary is likely to occur at any time. In this study, Bruce ladder PCR and abortus-melitensis-ovis-suis (AMOS) PCR assays were used to characterize 47 Brucella isolates from Indian origin in order to know exact species for understanding epidemiology of brucellosis. Out of them, 28, 14, and 5 isolates were found to be Brucella abortus, Brucella melitensis, and Brucella suis, respectively. Further analysis by AMOS PCR has identified that all the B. abortus isolates belong to any one of the biovar 1, 2, or 4; of the five B. suis isolates, three belong to biovar 1 and two belong to any one of the biovar 2, 3, 4, or 5. Although this multiplex Bruce ladder PCR is useful in differentiating all Brucella species, elaborate study is required to further characterize the isolates at exact biovar level.

  18. Differentiation between serological responses to Brucella suis and Yersinia enterocolitica serotype O : 9 after natural or experimental infection in pigs

    DEFF Research Database (Denmark)

    Jungersen, Gregers; Sørensen, Vibeke; Giese, Steen Bjørck

    2006-01-01

    responses in a YeO:9-purified O-antigen indirect ELISA did not decrease accordingly. Analysis of available cross-sectional serum samples from pig herds naturally infected with YeO: 9 or B. suis biovar 2 confirmed that the observed difference in the duration of the serological responses between the two...... infections could be used to discriminate between herds infected with B. suis biovar 2 and YeO:9....

  19. Discriminating microsatellites from Macrophomina phaseolina and their potential association to biological functions

    Science.gov (United States)

    The fungal pathogen Macrophomina phaseolina (Tassi) Goid. (=M. phaseoli [Maubl.] Ashby) causes charcoal rot disease in a vast number of plant species including soybean, cotton, sunflower and maize, resulting in significant economic losses. M. phaseolina exhibits apparent genetic adaptation to the p...

  20. Environ: E00450 [KEGG MEDICUS

    Lifescience Database Archive (English)

    Full Text Available E00450 Vigna angularis seed Phaseoli semen Crude drug Phytosterol Vigna angularis [...TAX:3914] Fabaceae (pea family) Vigna angularis mature seed (dried) Crude drugs [BR:br08305] Dicot plants: rosids Fabaceae (pea family) E00450 Vigna angularis seed ...

  1. Adaptabilidade, estabilidade e resistência a patógenos em genótipos de feijoeiro

    Directory of Open Access Journals (Sweden)

    Cleber Vinicius Giaretta Azevedo

    2015-10-01

    Full Text Available Resumo:O objetivo deste trabalho foi avaliar a resistência de genótipos de feijoeiro aos principais patógenos da cultura, bem como a adaptabilidade e a estabilidade de produção de grãos desses genótipos. Avaliaram-se 26 genótipos de feijoeiro quanto à resistência a Colletotrichum lindemuthianum, Fusarium oxysporum f. sp. phaseolie Xanthomonas axonopodis pv. phaseoli, por meio de inoculação, em laboratório, e em 19 ensaios de valor de cultivo e uso (VCU, em diferentes locais do Estado de São Paulo, nas safras das "águas", "seca" e "inverno", durante os anos agrícolas 2011, 2012 e 2013. Dezoito genótipos foram considerados resistentes: sete deles a C. lindemuthianum, sete a F. oxysporumf. sp. phaseolie quatro a X. axonopodispv. phaseoli. A reação de resistência aos patógenos está associada à estabilidade dos genótipos. Por meio das análises GGE biplot, foi possível identificar genótipos com adaptabilidade e estabilidade superiores às das testemunhas, nos dois grupos de tegumento avaliados, em todas as épocas de semeadura.

  2. Fungal mitochondrial DNases: Effectors with the potential to activate plant defenses in nonhost resistance

    Science.gov (United States)

    Previous reports on the model nonhost resistance interaction between Fusarium solani f. sp. phaseoli (Fsph) and pea endocarp tissue, have described the signaling role of a fungal DNase1-like protein. This enzyme termed, FsphDNase, induced complete resistance in pea tissue against pea pathogens, no ...

  3. MLVA genotyping of Brucella melitensis and Brucella abortus isolates from different animal species and humans and identification of Brucella suis vaccine strain S2 from cattle in China.

    Directory of Open Access Journals (Sweden)

    Hai Jiang

    Full Text Available In China, brucellosis is an endemic disease and the main sources of brucellosis in animals and humans are infected sheep, cattle and swine. Brucella melitensis (biovars 1 and 3 is the predominant species, associated with sporadic cases and outbreak in humans. Isolates of B. abortus, primarily biovars 1 and 3, and B. suis biovars 1 and 3 are also associated with sporadic human brucellosis. In this study, the genetic profiles of B. melitensis and B. abortus isolates from humans and animals were analyzed and compared by multi-locus variable-number tandem-repeat analysis (MLVA. Among the B. melitensis isolates, the majority (74/82 belonged to MLVA8 genotype 42, clustering in the 'East Mediterranean' group. Two B. melitensis biovar 1 genotype 47 isolates, belonging to the 'Americas' group, were recovered; both were from the Himalayan blue sheep (Pseudois nayaur, a wild animal. The majority of B. abortus isolates (51/70 were biovar 3, genotype 36. Ten B. suis biovar 1 field isolates, including seven outbreak isolates recovered from a cattle farm in Inner Mongolia, were genetically indistinguishable from the vaccine strain S2, based on MLVA cluster analysis. MLVA analysis provided important information for epidemiological trace-back. To the best of our knowledge, this is the first report to associate Brucella cross-infection with the vaccine strain S2 based on molecular comparison of recovered isolates to the vaccine strain. MLVA typing could be an essential assay to improve brucellosis surveillance and control programs.

  4. The effect of acidity on the distribution and symbiotic efficiency of rhizobia in Lithuanian soils

    Science.gov (United States)

    Lapinskas, E. B.

    2007-04-01

    The distribution and symbiotic efficiency of nodule bacteria Rhizobium leguminosarum_bv. trifolii F., Sinorhizobium meliloti D., Rhizobium galegae L., and Rhizobium leguminosarum bv. viciae F. in Lithuanian soils as dependent on the soil acidity were studied in the long-term field, pot, and laboratory experiments. The critical and optimal pH values controlling the distribution of rhizobia and the symbiotic nitrogen fixation were determined for every bacterial species. The relationship was found between the soil pH and the nitrogen-fixing capacity of rhizobia. A positive effect of liming of acid soils in combination with inoculation of legumes on the efficiency of symbiotic nitrogen fixation was demonstrated.

  5. Effects of nano-ZnO on the agronomically relevant Rhizobium-legume symbiosis

    Science.gov (United States)

    The impact of nano-ZnO (nZnO) on Rhizobium-legume symbiosis was studied with garden pea and its compatible bacterial partner Rhizobium leguminosarum bv. viciae 3841. Exposure of peas to nZnO had no impact on germination, but significantly affected root length. Chronic exposure of plant to nZnO impac...

  6. Effects of nano-TiO2 on the agronomically-relevant Rhizobium-legume symbiosis

    Science.gov (United States)

    The impact of nano-TiO2 on Rhizobium-legume symbiosis was studied using garden peas and the compatible bacterial partner Rhizobium leguminosarum bv. viciae 3841. Exposure to nano-TiO2 did not affect the germination of peas grown aseptically, nor did it impact the gross root structure. However, nano-...

  7. GenBank blastx search result: AK110582 [KOME

    Lifescience Database Archive (English)

    Full Text Available ltransferase/uridylyl-removing enzyme (glnD) gene, complete cds; and MviN (mviN) gene, partial cds.|BCT BCT 1e-40 +2 ... ...AK110582 002-168-E10 AF155830.1 Rhizobium leguminosarum bv. viciae putative uridyly

  8. Root hair deformation activity of nodulation factor and their fate on Vicia sativa.

    NARCIS (Netherlands)

    Heidstra, R.; Geurts, R.; Franssen, H.; Spaink, H.P.; Kammen, van A.; Bisseling, T.

    1994-01-01

    We used a semiquantitative root hair deformation assay for Vicia sativa (vetch) to study the activity of Rhizobium leguminosarum bv viciae nodulation (Nod) factors. Five to 10 min of Nod factor-root interaction appears to be sufficient to induce root hair deformation. The first deformation is visibl

  9. Parallel variation in isoenzyme and nitrogen fixation markers in a Rhizobium population

    DEFF Research Database (Denmark)

    Engvild, K.C.; Jensen, E.S.; Skøt, L.

    1990-01-01

    Twenty isolates of Rhizobium leguminosarum bv. viceae were isolated at random from one field and examined for symbiotic plasmid fragment length polymorphisms and for isoenzyme patterns. The latter are most probably chromosome markers. With one exception both methods separated the isolates...

  10. Identification of Ononitol and O-methyl-scyllo-inositol in Pea Root Nodules

    DEFF Research Database (Denmark)

    Skøt, Leif; Egsgaard, Helge

    1984-01-01

    Ononitol (4-O-methyl-myo-inositol) and O-methyl-scyllo-inositol were identified in pea (Pisum sativum L.) root nodules formed by twoRhizobium leguminosarum strains. Ononitol was the major soluble carbohydrate in nodules formed by strain 1045 while O-methyl-scyllo-inositol and two unidentified...

  11. Molecular aspects of the nitrogen fixing system in pea root nodules

    NARCIS (Netherlands)

    Bisseling, T.

    1980-01-01

    This thesis deals with research on symbiotic nitrogen fixation of Pisumsativum and Rhizobium Leguminosarum. Nitrogen fixation takes place in the Rhizobium bacteroids which are located within root nodule cells. Two im

  12. [DNA homology in various strains of nitrogen-fixing bacteria].

    Science.gov (United States)

    Vardevanian, P O; Minasbekian, L A; Parsadanian, M A

    2000-01-01

    Melting temperature and GC content were evaluated for DNA of some nitrogen-fixing bacteria of Rhizobium leguminosarum and Onobrychis spp. (Adans). The degree of homology between strains of the same species was determined. A combination of thermal denaturing and molecular hybridization can serve as a rapid test for evaluating the genome homology of the organisms compared.

  13. The Rhizobium-pea symbiosis as affected by high temperatures

    NARCIS (Netherlands)

    Frings, J.F.J.

    1976-01-01

    A study has been made concerning the effect of high temperatures on the symbiosis of Rhizobium leguminosarum and pea plants (Pisum sativum). At 30°C, no nodules were found on the roots of plants growing in nutrient solution after inoculation with the appropriate bacteria. This is in contrast to the

  14. Pea-root exudates and their effect upon root-nodule bacteria

    NARCIS (Netherlands)

    Egeraat, van A.W.S.M.

    1972-01-01

    The main purpose of this investigation was to study the exudation (mechanism, sites) of various compounds by roots of pea seedlings in relation to the growth of Rhizobium leguminosarum.Chapter 1 gives a survey of the literature pertaining to plant-root exudates and their influence upon soil microorg

  15. Effect of combined nitrogen on symbiotic nitrogen fixation in pea plants

    NARCIS (Netherlands)

    Houwaard, F.

    1979-01-01

    The nitrogen-fixing activity of the symbiotic system of Pisum sativum with Rhizobium leguminosarum is adversely affected by combined nitrogen. Both ammonium chloride and potassium nitrate, when added to the roots, lower the nitrogenase activity (acetylene-reduction) of intact pea plants. During a 3-

  16. The pea early nodulin gene PsENOD7 maps in the region of linkage group I containing sym2 and leghaemoglobin.

    NARCIS (Netherlands)

    Kozik, A.; Matvienko, M.; Scheres, B.; Paruvangada, V.G.; Bisseling, T.; Kammen, van A.; Ellis, T.H.N.; LaRue, T.; Weeden, N.

    1996-01-01

    The early nodulin gene, PsENOD7, is expressed in pea root nodules induced by Rhizobium leguminosarum bv. viciae, but not in other plant organs. In situ hybridization showed that this gene is transcribed during nodule maturation in the infected cells of the proximal part of the prefixation zone II.

  17. Chlamydia trachomatis Mip-like protein

    DEFF Research Database (Denmark)

    Lundemose, AG; Rousch, DA; Birkelund, Svend

    1992-01-01

    A 27 kDa Chlamydia trachomatis Mip-like protein with homology of a 175-amino-acid C-terminal fragment to the surface-exposed Legionella pneumophila mip-gene product has previously been described. In this paper the entire chlamydia Mip-like sequence of C. trachomatis serovar L2 (lymphogranuloma...... venereum (LGV) biovar) is presented. The sequence shows high similarity to the legionella Mip protein and its C-terminal region, like that of the legionella Mip, has high amino acid similarity to eukaryotic and prokaryotic FK506-binding proteins. The chlamydial mip-like gene was detected by polymerase...... chain reaction (PCR) in other C. trachomatis serovars and by sequencing of the mip-like genes of serovars B and E (trachoma biovar) was shown to be highly conserved within the two major biovars of C. trachomatis. Monoclonal and polyclonal antibodies raised against the recombinant Mip-like protein failed...

  18. Chlamydia trachomatis Mip-like protein

    DEFF Research Database (Denmark)

    Lundemose, AG; Rousch, DA; Birkelund, Svend

    1992-01-01

    A 27 kDa Chlamydia trachomatis Mip-like protein with homology of a 175-amino-acid C-terminal fragment to the surface-exposed Legionella pneumophila mip-gene product has previously been described. In this paper the entire chlamydia Mip-like sequence of C. trachomatis serovar L2 (lymphogranuloma...... chain reaction (PCR) in other C. trachomatis serovars and by sequencing of the mip-like genes of serovars B and E (trachoma biovar) was shown to be highly conserved within the two major biovars of C. trachomatis. Monoclonal and polyclonal antibodies raised against the recombinant Mip-like protein failed...... venereum (LGV) biovar) is presented. The sequence shows high similarity to the legionella Mip protein and its C-terminal region, like that of the legionella Mip, has high amino acid similarity to eukaryotic and prokaryotic FK506-binding proteins. The chlamydial mip-like gene was detected by polymerase...

  19. Isolation and Molecular Characterization of Brucella Isolates in Cattle Milk in Uganda

    Directory of Open Access Journals (Sweden)

    Denis Rwabiita Mugizi

    2015-01-01

    Full Text Available Brucellosis is endemic in livestock and humans in Uganda and its transmission involves a multitude of risk factors like consumption of milk from infected cattle. To shed new light on the epidemiology of brucellosis in Uganda the present study used phenotypic and molecular approaches to delineate the Brucella species, biovars, and genotypes shed in cattle milk. Brucella abortus without a biovar designation was isolated from eleven out of 207 milk samples from cattle in Uganda. These isolates had a genomic monomorphism at 16 variable number tandem repeat (VNTR loci and showed in turn high levels of genetic variation when compared with other African strains or other B. abortus biovars from other parts of the world. This study further highlights the usefulness of MLVA as an epidemiological tool for investigation of Brucella infections.

  20. Biotyping and genotyping (MLVA16 of Brucella abortus isolated from cattle in Brazil, 1977 to 2008.

    Directory of Open Access Journals (Sweden)

    Sílvia Minharro

    Full Text Available Brucellosis is a worldwide distributed zoonosis that causes important economic losses to animal production. In Brazil, information on the distribution of biovars and genotypes of Brucella spp. is scarce or unavailable. This study aimed (i to biotype and genotype 137 Brazilian cattle isolates (from 1977 to 2008 of B. abortus and (ii to analyze their distribution. B. abortus biovars 1, 2 and 3 (subgroup 3b were confirmed and biovars 4 and 6 were first described in Brazil. Genotyping by the panel 1 revealed two groups, one clustering around genotype 40 and another around genotype 28. Panels 2A and 2B disclosed a high diversity among Brazilian B. abortus strains. Eighty-nine genotypes were found by MLVA16. MLVA16 panel 1 and 2 showed geographic clustering of some genotypes. Biotyping and MLVA16 genotyping of Brazilian B. abortus isolates were useful to better understand the epidemiology of bovine brucellosis in the region.

  1. PHYSIOLOGICAL CHANGES IN BEAN (PHASEOLUS VULGARIS L. LEAVES, INFECTED BY THE MOST IMPORTANT BEAN DISEA

    Directory of Open Access Journals (Sweden)

    MALGOJATA BEROVA

    2007-11-01

    Full Text Available Gas-exchange, plastid pigments and some other physiological parameters were determined in bean (Phaseolus vulgaris L. local populations leaves naturally infected by Xanthomonas campestris pv.phaseoli (Smith Dye, and Pseudomonas syringae pv.phaseolicola (Bukholder Young, Dye et Wilkie, and in healthy leaves (control. It was established that infected leaves had lower both plastid pigments content and photosynthetic activity as well as lower yield and quality of produce.

  2. Chemical Composition and Antibacterial Activity of Essential Oils of Tagetes minuta (Asteraceae) against Selected Plant Pathogenic Bacteria

    OpenAIRE

    Martin Muthee Gakuubi; Wagacha, John M.; Saifuddin F. Dossaji; Wycliffe Wanzala

    2016-01-01

    The objective of this study was to determine the chemical composition and antibacterial activity of essential oils (EOs) of Tagetes minuta against three phytopathogenic bacteria Pseudomonas savastanoi pv. phaseolicola, Xanthomonas axonopodis pv. phaseoli, and Xanthomonas axonopodis pv. manihotis. The essential oils were extracted using steam distillation method in a modified Clevenger-type apparatus while antibacterial activity of the EOs was evaluated by disc diffusion method. Gas chromatogr...

  3. Novel Task Functionalized Biopolymers for Enhanced Change Detection in Support of C-IED Operations

    Science.gov (United States)

    2013-04-15

    produced by a soil bacterial species, Rhizobium tropici(RTEPS) and 3) polyacrylamide, a synthetic polymer that is considered the standard for soil...Franzén, L.-E., Darvill, J.E., McNeil, M., Darvill, A.G., Albersheim, P., 1983a. The structure of the acidic polysaccharide secreted by Rhizobium ...Bulletin 128991. ----- 1983b. The structure of the acidic polysaccharide secreted by Rhizobium phaseoli Strain 127 K87. Carbohydr. Res. 117, 169-183

  4. Application of some insecticides and plant crude extracts for controlling insect pests in yard long bean

    OpenAIRE

    2003-01-01

    Tests on plant crude extracts of neem seeds, galanga and citronella grass at the rates of 200 ml/20 L of water together with synthetic insecticides, cypermethrin, methamidophos, carbosulfan and carbofuran, at the recommended rates showed that none of the treatments was effective in controlling plant damage caused by adult of bean fly (Ophiomyia phaseoli Tryon). The application of the synthetic insecticide, methamidophos, and plant crude extracts of neem seeds + galanga + citronella grass prov...

  5. Differential phenotyping of Brucella species using a newly developed semi-automated metabolic system

    Science.gov (United States)

    2010-01-01

    Background A commercial biotyping system (Taxa Profile™, Merlin Diagnostika) testing the metabolization of various substrates by bacteria was used to determine if a set of phenotypic features will allow the identification of members of the genus Brucella and their differentiation into species and biovars. Results A total of 191 different amines, amides, amino acids, other organic acids and heterocyclic and aromatic substrates (Taxa Profile™ A), 191 different mono-, di-, tri- and polysaccharides and sugar derivates (Taxa Profile™ C) and 95 amino peptidase- and protease-reactions, 76 glycosidase-, phosphatase- and other esterase-reactions, and 17 classic reactions (Taxa Profile™ E) were tested with the 23 reference strains representing the currently known species and biovars of Brucella and a collection of 60 field isolates. Based on specific and stable reactions a 96-well "Brucella identification and typing" plate (Micronaut™) was designed and re-tested in 113 Brucella isolates and a couple of closely related bacteria. Brucella species and biovars revealed characteristic metabolic profiles and each strain showed an individual pattern. Due to their typical metabolic profiles a differentiation of Brucella isolates to the species level could be achieved. The separation of B. canis from B. suis bv 3, however, failed. At the biovar level, B. abortus bv 4, 5, 7 and B. suis bv 1-5 could be discriminated with a specificity of 100%. B. melitensis isolates clustered in a very homogenous group and could not be resolved according to their assigned biovars. Conclusions The comprehensive testing of metabolic activity allows cluster analysis within the genus Brucella. The biotyping system developed for the identification of Brucella and differentiation of its species and biovars may replace or at least complement time-consuming tube testing especially in case of atypical strains. An easy to handle identification software facilitates the applicability of the Micronaut

  6. Differential phenotyping of Brucella species using a newly developed semi-automated metabolic system

    Directory of Open Access Journals (Sweden)

    Appel Bernd

    2010-10-01

    Full Text Available Abstract Background A commercial biotyping system (Taxa Profile™, Merlin Diagnostika testing the metabolization of various substrates by bacteria was used to determine if a set of phenotypic features will allow the identification of members of the genus Brucella and their differentiation into species and biovars. Results A total of 191 different amines, amides, amino acids, other organic acids and heterocyclic and aromatic substrates (Taxa Profile™ A, 191 different mono-, di-, tri- and polysaccharides and sugar derivates (Taxa Profile™ C and 95 amino peptidase- and protease-reactions, 76 glycosidase-, phosphatase- and other esterase-reactions, and 17 classic reactions (Taxa Profile™ E were tested with the 23 reference strains representing the currently known species and biovars of Brucella and a collection of 60 field isolates. Based on specific and stable reactions a 96-well "Brucella identification and typing" plate (Micronaut™ was designed and re-tested in 113 Brucella isolates and a couple of closely related bacteria. Brucella species and biovars revealed characteristic metabolic profiles and each strain showed an individual pattern. Due to their typical metabolic profiles a differentiation of Brucella isolates to the species level could be achieved. The separation of B. canis from B. suis bv 3, however, failed. At the biovar level, B. abortus bv 4, 5, 7 and B. suis bv 1-5 could be discriminated with a specificity of 100%. B. melitensis isolates clustered in a very homogenous group and could not be resolved according to their assigned biovars. Conclusions The comprehensive testing of metabolic activity allows cluster analysis within the genus Brucella. The biotyping system developed for the identification of Brucella and differentiation of its species and biovars may replace or at least complement time-consuming tube testing especially in case of atypical strains. An easy to handle identification software facilitates the

  7. Siderophore and organic acid production in root nodule bacteria.

    Science.gov (United States)

    Carson, K C; Holliday, S; Glenn, A R; Dilworth, M J

    1992-01-01

    Nineteen strains of root nodule bacteria were grown under various iron regimes (0.1, 1.0 and 20 microM added iron) and tested for catechol and hydroxamate siderophore production and the excretion of malate and citrate. The growth response of the strains to iron differed markedly. For 12 strains (Bradyrhizobium strains NC92B and 32H1, B. japonicum USDA110 and CB1809, B. lupini WU8, cowpea Rhizobium NGR234, Rhizobium meliloti strains U45 and CC169, Rhizobium leguminosarum bv viciae WU235 and Rhizobium leguminosarum bv trifolii strains TA1, T1 and WU95) the mean generation time showed no variation with the 200-fold increase in iron concentration. In contrast, in Bradyrhizobium strains NC921, CB756 and TAL1000, B. japonicum strain 61A76 and R. leguminosarum bv viciae MNF300 there was a 2-5 fold decrease in growth rate at low iron. R. meliloti strains WSM419 and WSM540 showed decreased growth at high iron. All strains of root nodule bacteria tested gave a positive CAS (chrome azurol S) assay for siderophore production. No catechol-type siderophores were found in any strain, and only R. leguminosarum bv trifolii T1 and bv viciae WU235 produced hydroxamate under low iron (0.1 and 1.0 microM added iron). Malate was excreted by all strains grown under all iron regimes. Citrate was excreted by B. japonicum USDA110 and B. lupini WU8 in all iron concentrations, while Bradyrhizobium TAL1000, R. leguminosarum bv viciae MNF300 and B. japonicum 61A76 only produced citrate under low iron (0.1 and/or 1.0 microM added iron) during the stationary phase of growth.

  8. 两种豆科药材及其混伪品的可溶性蛋白质电泳鉴别%Electrophoresis identification of two leguminosae Chinese drugs and the ir adulterants

    Institute of Scientific and Technical Information of China (English)

    马晓莉; 史超群

    2001-01-01

    目的:对赤小豆、决明子及其混伪品进行电泳鉴别,并考察考马 斯亮蓝G-250的染色效果。方法:可溶性蛋白质凝胶电泳。 结果:赤小豆、决明子及其混伪品的电泳图谱存在显著差异。结论:电泳图谱可作为赤小豆、决明子及其混伪品的鉴别依据,考马斯亮蓝G-250可用于电泳 鉴别。%OBJECTIVE:To identify two leguminosae Chinese drugs,semen phaseoli,semen cassiae,and their adulterants by electrophoresis and to study the dyeing effect of coomassie brilliant blue G-250.METHOD:Gel electrophoresis of soluble protein was used.RESULTS:The elect rophoretograms of semen phaseoli,semen cassiae and their adulterants are used d ifferent.CONCLUSION:The electrophoretograms can be used to different iate semen phaseoli and semen cassiae from their adulterants.Coomassie brilliant blue G-250 can be used in the electrophoresis identification.

  9. Population dynamics of Streptococcus mitis in its natural habitat

    DEFF Research Database (Denmark)

    Hohwy, J.; Reinholdt, Jesper; Kilian, Mogens

    2001-01-01

    The purpose of this study was to examine the genetic structure of the typical commensal Streptococcus mitis biovar 1 in its natural habitat in the human oral cavity and pharynx and to investigate the role that selected microbial properties and host, spatial, and temporal factors play in determining...... showed that the ability to persist was not distributed at random in the S. mitis biovar 1 population. However, neither immunoglobulin A1 protease activity nor the ability to bind alpha-amylase from saliva was a preferential characteristic of persistent genotypes. In contrast to current concepts of climax...

  10. THERMOTOLERANT Campylobacter SPECIES ISOLATED FROM PSITTACIFORMES IN THE PERUVIAN AMAZON REGION

    Directory of Open Access Journals (Sweden)

    Alvaro TRESIERRA-AYALA

    1998-07-01

    Full Text Available Foi determinada a freqüência de isolamento de campylobacters termotolerantes em Psittaciformes silvestres capturados na região amazônica do Peru. Campylobacters foram isolados em 10/142 (7.0% dos animais estudados, sendo C. jejuni subsp. jejuni biovar I (6/10 o mais freqüente, seguido de C. coli biovar II (2/10, C. lari não foi isolado. Os resultados sugerem que estas aves podem ser importantes reservatórios destas bactérias.

  11. Studies on a suitable antibiotic therapy for treating swine brucellosis.

    Science.gov (United States)

    Dieste-Pérez, L; Fraile, L; de Miguel, M J; Barberán, M; Blasco, J M; Muñoz, P M

    2015-08-01

    The aim of this work was developing effective treatments against Brucella suis biovar 2, responsible for swine brucellosis in Europe. MICs for antibiotics used classically in brucellosis and two new macrolides (tulathromycin and tildipirosin) were determined for 33 B. suis biovar 2 field and B. suis reference strains. MIC90 values ranged from 0.01 to 0.25 μg/mL. The best candidates, given alone or combined, were then evaluated in mice. Ten groups (n = 7) of BALB/c mice were inoculated (1 × 10(5) CFU/mouse) with a virulent B. suis biovar 2 field strain. All groups, excepting untreated control, were treated for 14 days with, respectively, doxycycline, dihydrostreptomycin, tulathromycin (one or two doses), or tildipirosin (one or two doses) given alone, and doxycycline combined with dihydrostreptomycin, tulathromycin, or tildipirosin. Combined tildipirosin treatment was the most effective, then selected for pig studies. Sixteen B. suis biovar 2 naturally infected sows were treated with oxytetracycline (20 mg/kg BW/daily) for 21 days. The half of these received also tildipirosin (4 mg/kg BW) in two doses with a 10-day interval. An extensive bacteriological study conducted ten days after ceasing treatments proved the efficacy of this combined oxytetracycline/tildipirosin treatment.

  12. Stenotrophomonas maltophilia: a new potential biocontrol agent of Ralstonia solanacearum, causal agent of potato brown rot

    NARCIS (Netherlands)

    Messiha, N.A.S.; Diepeningen, van A.D.; Farag, N.S.; Abdallah, S.A.; Janse, J.D.; Bruggen, van A.H.C.

    2007-01-01

    Stenotrophomonas maltophilia was isolated from the rhizosphere of eggplant in the Nile Delta of Egypt, and its antagonistic potential against Ralstonia solanacearum race 3 biovar 2, the causal agent of potato brown rot, was in vitro evaluated on KB agar medium and in vivo on potato plants. In vitro,

  13. Potato brown rot incidence and severity under different management and amendment regimes in different soil types

    NARCIS (Netherlands)

    Messiha, N.A.S.; Bruggen, van A.H.C.; Diepeningen, van A.D.; Vos, de O.J.; Termorshuizen, A.J.; Tjou-Tam-Sin, N.N.A.; Janse, J.D.

    2007-01-01

    Ralstonia solanacearum race 3 biovar 2, the causative agent of potato brown rot (bacterial wilt), is an economically important disease in tropical, subtropical and temperate regions of the world. In view of previous reports on suppression of the disease by organic amendments, and the expansion of or

  14. Population dynamics of Streptococcus mitis in its natural habitat

    DEFF Research Database (Denmark)

    Hohwy, J.; Reinholdt, Jesper; Kilian, Mogens

    2001-01-01

    showed that the ability to persist was not distributed at random in the S. mitis biovar 1 population. However, neither immunoglobulin A1 protease activity nor the ability to bind alpha-amylase from saliva was a preferential characteristic of persistent genotypes. In contrast to current concepts of climax...

  15. Isolation and Characterization of Ralstonia solanacearum Causing ...

    African Journals Online (AJOL)

    Prof. Ogunji

    requires definite information on race and biovar characteristics of the pathogen in those endemic ... possibility for chemical control, high capacity of ... carried out by adding 1 ml of the sample to 9 .... Bacterial cells (100 mg) were added to a ZR BashingBeadTM Lysis Tube and ..... effects (Murakoshi and Takahashi, 1984).

  16. Non-imported brucellosis outbreak from unpasteurized raw milk in Moroccan immigrants in Spain

    Science.gov (United States)

    RAMOS, J. M.; BERNAL, E.; ESGUEVILLAS, T.; LOPEZ-GARCIA, P.; GAZTAMBIDE, M. S.; GUTIERREZ, F.

    2008-01-01

    SUMMARY Nine cases of brucellosis were identified in the city of Elche (Comunidad Valenciana, Spain) in two families of Moroccan immigrants. All of the patients had drunk unpasteurized raw milk from goats. Brucella melitensis biovar 3 was identified in clinical specimens. Preventive measures for brucellosis should be implemented among immigrant populations in Spain. PMID:18205974

  17. El problema práctico de la brucelosis: buscando soluciones

    OpenAIRE

    Grilló, María Jesús

    2011-01-01

    La brucelosis es una zoonosis extendida mundialmente, causada por bacterias del género Brucella. Existe una amplia variedad de especies y biovares de Brucella, clasificadas en función de su estructura antigénica y hospedador animal preferente, aunque sólo algunas de ellas han sido aisladas en humanos.

  18. A polyphasic approach for studying the interaction between Ralstonia solanacearum and potential control agents in the tomato phytosphere

    NARCIS (Netherlands)

    Overbeek, van L.S.; Cassidy, M.; Kozdroj, J.; Trevors, J.T.; Elsas, van J.D.

    2002-01-01

    Ralstonia solanacearum biovar 2, the causative agent of brown rot in potato, has been responsible for large crop losses in Northwest Europe during the last decade. Knowledge on the ecological behaviour of R. solanacearum and its antagonists is required to develop sound procedures for its control and

  19. A multiplex PCR assay to detect and differentiate select agent strains of Ralstonia solanacearum

    Science.gov (United States)

    Ralstonia solanacearum causes bacterial wilt in a variety of cash crops. R. solanacearum race 3 biovar 2 strains are considered select agents by the U.S. Government because they are not endemic to the U.S. and have the potential to cause brown rot disease in our potato production fields. Simple and...

  20. A TaqMan-based multiplex qPCR assay and DNA extraction method for phylotype IIB sequevars 1&2 (select agent) strains of Ralstonia solanacearum

    Science.gov (United States)

    Ralstonia solanacearum race 3 biovar 2 strains have the ability to cause brown rot of potato in temperate climates. Since these strains are not established in the U.S. and because of the potential risk they pose to the potato industry, the U.S. government has listed them as select agents. Cultivated...

  1. Efficacy of antibiotic treatment and test-based culling strategies for eradicating brucellosis in commercial swine herds

    NARCIS (Netherlands)

    Dieste-Pérez, L.; Frankena, K.; Blasco, J. M.; Muñoz, P. M.; De Jong, M. C M

    2016-01-01

    Swine brucellosis caused by Brucella suis biovar 2 is an emerging disease in continental Europe. Without effective vaccines being available, the European Food Safety Authority (EFSA) recommends the full depopulation of infected herds as the only strategy to eradicate B. suis outbreaks. Using data co

  2. Efficacy of antibiotic treatment and test-based culling strategies for eradicating brucellosis in commercial swine herds

    NARCIS (Netherlands)

    Dieste-Pérez, L.; Frankena, K.; Blasco, J.M.; Muñoz, P.M.; Jong, de M.C.M.

    2016-01-01

    Swine brucellosis caused by Brucella suis biovar 2 is an emerging disease in continental Europe. Without effective vaccines being available, the European Food Safety Authority (EFSA) recommends the full depopulation of infected herds as the only strategy to eradicate B. suis outbreaks. Using data

  3. 78 FR 59628 - Importation of Potatoes From Mexico

    Science.gov (United States)

    2013-09-27

    ... bacterium that causes brown rot of potato.\\1\\ \\1\\ The PRA refers to this pest as ``Ralstonia solanacearum... this document. Rosellinia bunodes (Berk. & Broome) Sacc., a pathogenic fungus. R. pepo Pat., a... solanacearum race 3 biovar 2 (Smith) Yabuuchi et al., a bacterium that causes brown rot of potato; Rosellinia...

  4. Ralstonia solanacearum ¿PGI-1 Strain KZR-5 Is Affected in Growth, Response to Cold Stress and Invasion of Tomato

    NARCIS (Netherlands)

    Stevens, P.; Overbeek, van L.S.; Elsas, van J.D.

    2011-01-01

    The survival and persistence of Ralstonia solanacearum biovar 2 in temperate climates is still poorly understood. To assess whether genomic variants of the organism show adaptation to local conditions, we compared the behaviour of environmental strain KZR-5, which underwent a deletion of the 17.6 kb

  5. Ralstonia solanacearum Delta PGI-1 Strain KZR-5 Is Affected in Growth, Response to Cold Stress and Invasion of Tomato

    NARCIS (Netherlands)

    Stevens, Patricia; van Overbeek, Leonard Simon; van Elsas, Jan Dirk

    2011-01-01

    The survival and persistence of Ralstonia solanacearum biovar 2 in temperate climates is still poorly understood. To assess whether genomic variants of the organism show adaptation to local conditions, we compared the behaviour of environmental strain KZR-5, which underwent a deletion of the 17.6 kb

  6. Differentiation between serological responses to Brucella suis and Yersinia enterocolitica serotype O : 9 after natural or experimental infection in pigs

    DEFF Research Database (Denmark)

    Jungersen, Gregers; Sørensen, Vibeke; Giese, Steen Bjørck

    2006-01-01

    with responses of B. suis biovar 2-inoculated pigs. FPSR were limited to 2-9 weeks post-YeO:9 inoculation, while B. suis-infected pigs were test-positive throughout the 21-week period of investigation. Although YeO:9-inoculated pigs exhibited FPSR in Brucella tests for a limited period of time, the serological...

  7. "HOOF-Print" Genotyping and Haplotype Inference Discriminates among Brucella spp Isolates From a Small Spatial Scale

    Science.gov (United States)

    We demonstrate that the “HOOF-Print” assay provides high power to discriminate among Brucella isolates collected on a small spatial scale (within Portugal). Additionally, we illustrate how haplotype identification using non-random association among markers allows resolution of B. melitensis biovars ...

  8. Susceptibility of Geranium Cultivars (Pelargonium spp.) to Ralstonia solanacearum

    Science.gov (United States)

    Sixty-one cultivars of geraniums including zonal, regal, ivy, and scented were tested for susceptibility to three strains of Ralstonia solanacearum: a Race 1 Biovar 1 (R1B1) strain P597 isolated from tomato in Florida, a R1B1 strain P673 obtained from pothos originating in Costa Rica, and a Race 3 B...

  9. Efficacy of two fungus-based biopesticide against the honeybee ectoparasitic mite, Varroa destructor.

    Science.gov (United States)

    Ahmed, Abdelaal A; Abd-Elhady, Hany K

    2013-08-15

    The varroa mite, Varroa destructor (Anderson and Trueman) (Acari: Varroidae), is known as the most serious ectoparasitic mite on honeybee, Apis mellifera (Hymenoptera: Apidae) in the world. Based on the spores of entomopathogenic fungi, two commercial preparations; Bioranza (Metarhizium anisopliae) and Biovar (Beauveria bassiana) were evaluated through application into the hives against varroa mite. Data showed significant differences between treatments with Bioranza and Biovar, the results were significant after 7 and 14 days post-treatment. Mean a daily fallen mite individual was significantly different between the hives before and after the applications of the two biopesticides and wheat flour. Also, mites' mortality was, significantly, different between the hives before and after treatments. There were significant differences between treatments with the two biopesticides in worker's body weight. Bioranza and Biovar did not infect the honeybee in larval, prepupal, pupal and adult stages. Scanning and transmission electron microscopy images showed spores and hyphae penetration through stigma and wounds on varroa. The results suggest that Bioranza and Biovar are potentially are effective biopesticides against V. destructor in honeybee colonies.

  10. Similarity in Pathogenic Features in Lung and Peritoneal Infection by Coxiella burnetii, Typhus Group Rickettsiae, and Chlamydiae

    Science.gov (United States)

    1990-06-26

    trachomatis (mouse pneumonia biovar) (B, C). Arrows point to pneumocyte areas with chlamydial inclusions that are composed of reticulate bodies, some...of pathogenicity on microorganisms, including adhesive molecules, the adhesins, that interact with receptors on susceptible cells. 2 It appears that

  11. Genotyping and phylogenetic analysis of Yersinia pestis by MLVA: insights into the worldwide expansion of Central Asia plague foci.

    Directory of Open Access Journals (Sweden)

    Yanjun Li

    Full Text Available BACKGROUND: The species Yersinia pestis is commonly divided into three classical biovars, Antiqua, Medievalis, and Orientalis, belonging to subspecies pestis pathogenic for human and the (atypical non-human pathogenic biovar Microtus (alias Pestoides including several non-pestis subspecies. Recent progress in molecular typing methods enables large-scale investigations in the population structure of this species. It is now possible to test hypotheses about its evolution which were proposed decades ago. For instance the three classical biovars of different geographical distributions were suggested to originate from Central Asia. Most investigations so far have focused on the typical pestis subspecies representatives found outside of China, whereas the understanding of the emergence of this human pathogen requires the investigation of strains belonging to subspecies pestis from China and to the Microtus biovar. METHODOLOGY/PRINCIPAL FINDINGS: Multi-locus VNTR analysis (MLVA with 25 loci was performed on a collection of Y. pestis isolates originating from the majority of the known foci worldwide and including typical rhamnose-negative subspecies pestis as well as rhamnose-positive subspecies pestis and biovar Microtus. More than 500 isolates from China, the Former Soviet Union (FSU, Mongolia and a number of other foci around the world were characterized and resolved into 350 different genotypes. The data revealed very close relationships existing between some isolates from widely separated foci as well as very high diversity which can conversely be observed between nearby foci. CONCLUSIONS/SIGNIFICANCE: The results obtained are in full agreement with the view that the Y. pestis subsp. pestis pathogenic for humans emerged in the Central Asia region between China, Kazakhstan, Russia and Mongolia, only three clones of which spread out of Central Asia. The relationships among the strains in China, Central Asia and the rest of the world based on the MLVA

  12. Human brucellosis in Maghreb: existence of a lineage related to socio-historical connections with Europe.

    Science.gov (United States)

    Lounes, Nedjma; Cherfa, Moulay-Ali; Le Carrou, Gilles; Bouyoucef, Abdellah; Jay, Maryne; Garin-Bastuji, Bruno; Mick, Virginie

    2014-01-01

    Despite control/eradication programs, brucellosis, major worldwide zoonosis due to the Brucella genus, is endemic in Northern Africa and remains a major public health problem in the Maghreb region (Algeria/Morocco/Tunisia). Brucella melitensis biovar 3 is mostly involved in human infections and infects mainly small ruminants. Human and animal brucellosis occurrence in the Maghreb seems still underestimated and its epidemiological situation remains hazy. This study summarizes official data, regarding Brucella melitensis infections in Algeria, from 1989 to 2012, with the purpose to provide appropriate insights concerning the epidemiological situation of human and small ruminant brucellosis in Maghreb. Algeria and Europe are closely linked for historical and economical reasons. These historical connections raise the question of their possible impact on the genetic variability of Brucella strains circulating in the Maghreb. Other purpose of this study was to assess the genetic diversity among Maghreb B. melitensis biovar 3 strains, and to investigate their possible epidemiological relationship with European strains, especially with French strains. A total of 90 B. melitensis biovar 3 Maghreb strains isolated over a 25 year-period (1989-2014), mainly from humans, were analysed by MLVA-16. The obtained results were compared with genotypes of European B. melitensis biovar 3 strains. Molecular assays showed that Algerian strains were mainly distributed into two distinct clusters, one Algerian cluster related to European sub-cluster. These results led to suggest the existence of a lineage resulting from socio-historical connections between Algeria and Europe that might have evolved distinctly from the Maghreb autochthonous group. This study provides insights regarding the epidemiological situation of human brucellosis in the Maghreb and is the first molecular investigation regarding B. melitensis biovar 3 strains circulating in the Maghreb.

  13. Multi-locus variable-number tandem repeat analysis of Chinese Brucella strains isolated from 1953 to 2013.

    Science.gov (United States)

    Tian, Guo-Zhong; Cui, Bu-Yun; Piao, Dong-Ri; Zhao, Hong-Yan; Li, Lan-Yu; Liu, Xi; Xiao, Pei; Zhao, Zhong-Zhi; Xu, Li-Qing; Jiang, Hai; Li, Zhen-Jun

    2017-05-02

    Brucellosis was a common human and livestock disease caused by Brucella strains, the category B priority pathogens by the US Center for Disease Control (CDC). Identified as a priority disease in human and livestock populations, the increasing incidence in recent years in China needs urgent control measures for this disease but the molecular background important for monitoring the epidemiology of Brucella strains at the national level is still lacking. A total of 600 Brucella isolates collected during 60 years (from 1953 to 2013) in China were genotyped by multiple locus variable-number tandem repeat analysis (MLVA) and the variation degree of MLVA11 loci was calculated by the Hunter Gaston Diversity Index (HGDI) values. The charts and map were processed by Excel 2013, and cluster analysis and epidemiological distribution was performed using BioNumerics (version 5.1). The 600 representative Brucella isolates fell into 104 genotypes with 58 singleton genotypes by the MLVA11 assay, including B. melitensis biovars 2 and 3 (five main genotypes), B. abortus biovars 1 and 3 (two main genotypes), B. suis biovars 1 and 3 (three main genotypes), and B. canis (two main genotypes) respectively. While most B. suis biovar 1 and biovar 3 were respectively found in northern provinces and southern provinces, B. melitensis and B. abortus strains were dominant in China. Canine Brucellosis was only found in animals without any human cases reported. Eight Brucellosis epidemic peaks emerged during the 60 years between 1953 and 2013: 1955 - 1959, 1962 - 1969, 1971 - 1975, 1977 - 1983, 1985 - 1989, 1992 - 1997, 2000 - 2008 and 2010 - 2013 in China. Brucellosis has its unique molecular epidemiological patterns with specific spatial and temporal distribution according to MLVA. IDOP-D-16-00101.

  14. Strain identification in Rhizobium by starch gel electrophoresis of isoenzymes

    DEFF Research Database (Denmark)

    Engvild, Kjeld Christensen; Nielsen, G.

    1985-01-01

    Sonieated extracts of rhizobia, especiaUy Rhizobium leguminosarum from pea and vetch, were run in horizontal starch gel electrophoresis in the cold. The rhizobia were grown on agar on a slime suppressing substrate of tryptone-yeast extract-CaCl2 with small amounts of mannitol, sorbitol and arabin......Sonieated extracts of rhizobia, especiaUy Rhizobium leguminosarum from pea and vetch, were run in horizontal starch gel electrophoresis in the cold. The rhizobia were grown on agar on a slime suppressing substrate of tryptone-yeast extract-CaCl2 with small amounts of mannitol, sorbitol...... and arabinose and other sugars as enzyme inducers. After electrophoresis the gels were separated into several slabs by a gel cutter. Each slab was stained for a particular enzyme. Among numerous enzyme systems tested we found useful variation in esterases (EC 3.1.1.1, EC 3.1.1.2), 3-hydroxybutyrate...

  15. Genetic diversity of rhizobia nodulating native Vicia spp. in Sweden.

    Science.gov (United States)

    Ampomah, Osei Yaw; Huss-Danell, Kerstin

    2016-05-01

    Despite the recognition that Rhizobium leguminosarum sv. viciae is the most common symbiont of Vicia species worldwide, there is no available information on rhizobia nodulating native Vicia species in Sweden. We have therefore studied the genetic diversity and phylogeny of root nodule bacteria isolated from V. cracca, V. hirsuta, V. sepium, V. tetrasperma and V. sylvatica growing in different locations in Sweden as well as an isolate each from V. cracca in Tromsø, Norway, and V. multicaulis in Siberia, Russia. Out of 25 isolates sampled from the six Vicia species in 12 different locations, there were 14 different genotypes based on the atpD, recA and nodA gene phylogenies. All isolates were classified into Rhizobium leguminosarum sv. viciae group based on the concatenated atpD and recA phylogeny and the nodA phylogeny.

  16. "Comparación de algunas propiedades de las lectinas de semilla y de raíz de haba

    Directory of Open Access Journals (Sweden)

    Yolanda De Navarro

    2010-05-01

    Full Text Available Se aislaron las lectinas de semilla y de las paredes celulares de la raíz de haba. La lectina de raíz se purificó parcialmente por Sephadex G-25 obteniéndose resultados que sugieren la presencia de dos lectinas. El comportamiento en filtración por gel, diálisis, electroforesis inhibición por carbohidratos de la eritroaglutinación, acción aglutinante frente a la cepa B de R. leguminosarum cultivada en medio Bishop. capacidad aglutinante de cepas homologas y heterólogas de las dos lectinas demostraron que ellas son diferentes. La lectina de raíz parece ser más específica, ya que solo aglutinó a R. leguminosarum y R. spp. (caupi, mientras que la Favina presentó actividad bactoaglutinante con cepas nodulantes como con no nodulantes de diferentes especies de Rhizobium.

  17. Pyruvate Is Synthesized by Two Pathways in Pea Bacteroids with Different Efficiencies for Nitrogen Fixation▿

    OpenAIRE

    Mulley, Geraldine; Lopez-Gomez, Miguel; Zhang, Ye; Terpolilli, Jason; Prell, Jurgen; Finan, Turlough; Poole, Philip

    2010-01-01

    Nitrogen fixation in legume bacteroids is energized by the metabolism of dicarboxylic acids, which requires their oxidation to both oxaloacetate and pyruvate. In alfalfa bacteroids, production of pyruvate requires NAD+ malic enzyme (Dme) but not NADP+ malic enzyme (Tme). However, we show that Rhizobium leguminosarum has two pathways for pyruvate formation from dicarboxylates catalyzed by Dme and by the combined activities of phosphoenolpyruvate (PEP) carboxykinase (PckA) and pyruvate kinase (...

  18. Construction of a marker system for the evaluation of competitiveness for legume nodulation in Rhizobium strains.

    Science.gov (United States)

    Sánchez-Cañizares, Carmen; Palacios, Jose

    2013-03-01

    A marker system has been set up for the analysis of competitiveness of Rhizobium leguminosarum strains for legume nodulation. The strains generated incorporate gusA and celB marker genes at identical positions and allow efficient scoring of single and double infections. Based on this system, we have found that strain UPM791 outcompetes 3841 for nodulation in pea. This technique will be useful to determine the effect of different traits on competitiveness.

  19. Transposon Tn5 specifies streptomycin resistance in Rhizobium spp.

    OpenAIRE

    1984-01-01

    Transposon Tn5 conferred streptomycin resistance on different strains of Rhizobium meliloti, Rhizobium leguminosarum, and Rhizobium trifolii but not on Escherichia coli. A gene (str) specifying this phenotype has been identified and localized on the physical and genetic map of Tn5. It is transcribed from the promoter of neo, the gene that encodes neomycin phosphotransferase. The str gene is downstream from neo in a single transcriptional unit, as revealed by molecular cloning of different seg...

  20. Role of Symbiotic Auxotrophy in the Rhizobium-Legume Symbioses

    OpenAIRE

    Jurgen Prell; Alexandre Bourdès; Shalini Kumar; Emma Lodwig; Arthur Hosie; Seonag Kinghorn; James White; Philip Poole

    2010-01-01

    Background Rhizobium leguminosarum bv. viciae mutants unable to transport branched-chain amino acids via the two main amino acid ABC transport complexes AapJQMP and BraDEFGC produce a nitrogen starvation phenotype when inoculated on pea (Pisum sativum) plants [1], [2]. Bacteroids in indeterminate pea nodules have reduced abundance and a lower chromosome number. They reduce transcription of pathways for branched-chain amino acid biosynthesis and become dependent on their provision by the host....

  1. Conservation of Plasmid-Encoded Traits among Bean-Nodulating Rhizobium Species

    OpenAIRE

    Brom, Susana; Girard, Lourdes; García-de los Santos, Alejandro; Sanjuan-Pinilla, Julio M.; Olivares, José; Sanjuan, Juan

    2002-01-01

    Rhizobium etli type strain CFN42 contains six plasmids. We analyzed the distribution of genetic markers from some of these plasmids in bean-nodulating strains belonging to different species (Rhizobium etli, Rhizobium gallicum, Rhizobium giardinii, Rhizobium leguminosarum, and Sinorhizobium fredii). Our results indicate that independent of geographic origin, R. etli strains usually share not only the pSym plasmid but also other plasmids containing symbiosis-related genes, with a similar organi...

  2. Degradation of the Herbicide Glyphosate by Members of the Family Rhizobiaceae

    OpenAIRE

    Liu, C.-M.; McLean, P. A.; Sookdeo, C C; Cannon, F C

    1991-01-01

    Several strains of the family Rhizobiaceae were tested for their ability to degrade the phosphonate herbicide glyphosate (isopropylamine salt of N-phosphonomethylglycine). All organisms tested (seven Rhizobium meliloti strains, Rhizobium leguminosarum, Rhizobium galega, Rhizobium trifolii, Agrobacterium rhizogenes, and Agrobacterium tumefaciens) were able to grow on glyphosate as the sole source of phosphorus in the presence of the aromatic amino acids, although growth on glyphosate was not a...

  3. 2,4-D引导豌豆根瘤菌进入棉花形成根瘤的研究

    Institute of Scientific and Technical Information of China (English)

    杨永友

    2011-01-01

    用2,4-D处理水培养的棉花植株并接种豌豆根瘤菌Rhizobium leguminosarum,结果表明,2,4-D能诱导植株形成透明根瘤,且诱导的最佳浓度为0.05 mg/kg,与豌豆根瘤菌同时处理棉苗后,可促进根瘤形成.

  4. Rhizobium laguerreae sp. nov. nodulates Vicia faba on several continents.

    Science.gov (United States)

    Saïdi, Sabrine; Ramírez-Bahena, Martha-Helena; Santillana, Nery; Zúñiga, Doris; Álvarez-Martínez, Estela; Peix, Alvaro; Mhamdi, Ridha; Velázquez, Encarna

    2014-01-01

    Several fast-growing strains nodulating Vicia faba in Peru, Spain and Tunisia formed a cluster related to Rhizobium leguminosarum. The 16S rRNA gene sequences were identical to that of R. leguminosarum USDA 2370(T), whereas rpoB, recA and atpD gene sequences were phylogenetically distant, with sequence similarities of less than 96 %, 97 % and 94 %, respectively. DNA-DNA hybridization analysis showed a mean relatedness value of 43 % between strain FB206(T) and R. leguminosarum USDA 2370(T). Phenotypic characteristics of the novel strains also differed from those of the closest related species of the genus Rhizobium. Therefore, based on genotypic and phenotypic data obtained in this study, we propose to classify this group of strains nodulating Vicia faba as a novel species of the genus Rhizobium named Rhizobium laguerreae sp. nov. The type strain is FB206(T) ( = LMG 27434(T) = CECT 8280(T)).

  5. Induction of microbial genes for pathogenesis and symbiosis by chemicals from root border cells.

    Science.gov (United States)

    Zhu, Y; Pierson, L S; Hawes, M C

    1997-12-01

    Reporter strains of soil-borne bacteria were used to test the hypothesis that chemicals released by root border cells can influence the expression of bacterial genes required for the establishment of plant-microbe associations. Promoters from genes known to be activated by plant factors included virE, required for Agrobacterium tumefaciens pathogenesis, and common nod genes from Rhizobium leguminosarum bv viciae and Rhizobium meliloti, required for nodulation of pea (Pisum sativum) and alfalfa (Medicago sativum), respectively. Also included was phzB, an autoinducible gene encoding the biosynthesis of antibiotics by Pseudomonas aureofaciens. The virE and nod genes were activated to different degrees, depending on the source of border cells, whereas phzB activity remained unaffected. The homologous interaction between R. leguminosarum bv viciae and its host, pea, was examined in detail. Nod gene induction by border cells was dosage dependent and responsive to environmental signals. The highest levels of gene induction by pea (but not alfalfa) border cells occurred at low temperatures, when little or no bacterial growth was detected. Detached border cells cultured in distilled water exhibited increased nod gene induction (ini) in response to signals from R. leguminosarum bv viciae.

  6. Phylogenetic multilocus sequence analysis of native rhizobia nodulating faba bean (Vicia faba L.) in Egypt.

    Science.gov (United States)

    Youseif, Sameh H; Abd El-Megeed, Fayrouz H; Ageez, Amr; Cocking, Edward C; Saleh, Saleh A

    2014-12-01

    The taxonomic diversity of forty-two Rhizobium strains, isolated from nodules of faba bean grown in Egypt, was studied using 16S rRNA sequencing, multilocus sequence analyses (MLSA) of three chromosomal housekeeping loci and one nodulation gene (nodA). Based on the 16S rRNA gene sequences, most of the strains were related to Rhizobium leguminosarum, Rhizobium etli, and Rhizobium radiobacter (syn. Agrobacterium tumefaciens). A maximum likelihood (ML) tree built from the concatenated sequences of housekeeping proteins encoded by glnA, gyrB and recA, revealed the existence of three distinct genospecies (I, II and III) affiliated to the defined species within the genus Rhizobium/Agrobacterium. Seventeen strains in genospecies I could be classified as R. leguminosarum sv. viciae. Whereas, a single strain of genospecies II was linked to R. etli. Interestingly, twenty-four strains of genospecies III were identified as A. tumefaciens. Strains of R. etli and A. tumefaciens have been shown to harbor the nodA gene and formed effective symbioses with faba bean plants in Leonard jar assemblies. In the nodA tree, strains belonging to the putative genospecies were closely related to each other and were clustered tightly to R. leguminosarum sv. viciae, supporting the hypothesis that symbiotic and core genome of the species have different evolutionary histories and indicative of horizontal gene transfer among these rhizobia.

  7. Determinação da variabilidade em isolados de Colletotrichum lindemuthianum por meio de marcadores morfológicos e culturais

    OpenAIRE

    Breno Oliveira de Souza; Elaine Aparecida de Souza; Maria Cristina Mendes-Costa

    2007-01-01

    Colletotrichum lindemuthianum (teleomorfo Glomerella cingulata f. sp. phaseoli) apresenta ampla variabilidade genética, demonstrada por suas características morfológicas. Com este trabalho, objetivou-se caracterizar, por meio de marcadores morfológicos, diferentes isolados de C. lindemuthianum e identificar marcadores morfológicos com uso potencial em análises genéticas. Foram avaliados os seguintes caracteres morfológicos e culturais: cor e textura das colônias, compatibilidade vegetativa e ...

  8. ANTIBACTERIAL ACTIVITY OF THREE MEDICINAL PLANTS OF KUMAUN HIMALAYA AGAINST SOME PATHOGENIC BACTERIA

    Directory of Open Access Journals (Sweden)

    S. C. SATI

    2015-11-01

    Full Text Available The antibacterial property of methanol, ethanol and hexane extracts of Berberis aristata, Chenopodium ambrosioides and Tinospora cordifolia grown in Kumaun Himalayan were investigated against some pathogenic gram positive and gram negative bacterial strains (Bacillus subtilis, Agrobacterium tumefaciens, Escherichia coli, Xanthomonas phaseoli and Erwinia chrysanthemi using disc diffusion method. Methanol extract of B. aristata was found with highest inhibitory activity against E. chrysanthemi (ZOI, 11±0.3mm. Whereas lowest inhibition was recorded in ethanolic extract of B. aristata against E. coli. The hexane extract of B. aristata and methanolic extract of C. ambrosioides were found totally inactive against all the pathogens tested.

  9. Whole genome analysis of diverse Chlamydia trachomatis strains identifies phylogenetic relationships masked by current clinical typing

    Science.gov (United States)

    Harris, Simon R.; Clarke, Ian N.; Seth-Smith, Helena M. B.; Solomon, Anthony W.; Cutcliffe, Lesley T.; Marsh, Peter; Skilton, Rachel J.; Holland, Martin J.; Mabey, David; Peeling, Rosanna W.; Lewis, David A.; Spratt, Brian G.; Unemo, Magnus; Persson, Kenneth; Bjartling, Carina; Brunham, Robert; de Vries, Henry J.C.; Morré, Servaas A.; Speksnijder, Arjen; Bébéar, Cécile M.; Clerc, Maïté; de Barbeyrac, Bertille; Parkhill, Julian; Thomson, Nicholas R.

    2012-01-01

    Chlamydia trachomatis is responsible for both trachoma and sexually transmitted infections causing substantial morbidity and economic cost globally. Despite this, our knowledge of its population and evolutionary genetics is limited. Here we present a detailed whole genome phylogeny from representative strains of both trachoma and lymphogranuloma venereum (LGV) biovars from temporally and geographically diverse sources. Our analysis demonstrates that predicting phylogenetic structure using the ompA gene, traditionally used to classify Chlamydia, is misleading because extensive recombination in this region masks true relationships. We show that in many instances ompA is a chimera that can be exchanged in part or whole, both within and between biovars. We also provide evidence for exchange of, and recombination within, the cryptic plasmid, another important diagnostic target. We have used our phylogenetic framework to show how genetic exchange has manifested itself in ocular, urogenital and LGV C. trachomatis strains, including the epidemic LGV serotype L2b. PMID:22406642

  10. Dynamics of CRISPR Loci in Microevolutionary Process of Yersinia pestis Strains

    Science.gov (United States)

    Barros, Maria Paloma S.; França, Camila T.; Lins, Rosanny Holanda F. B.; Santos, Milena Danda V.; Silva, Ednaldo J.; Oliveira, Maria Betânia M.; Silveira-Filho, Vladimir M.; Rezende, Antônio M.; Balbino, Valdir Q.; Leal-Balbino, Tereza Cristina

    2014-01-01

    The potential use of CRISPR loci genotyping to elucidate population dynamics and microevolution of 146 Yersinia pestis strains from different biovars and locations was investigated in this work. The majority of strains from the Orientalis biovar presented specific spacer arrays, allowing for the establishment of a CRISPR signature for their respective isolates. Twenty-one new spacers were found in the Y. pestis strains from plague foci in Brazil. Ninety-three (64%) strains were grouped in the G1 genotype, whereas the others were distributed in 35 genotypes. This study allowed observing a microevolutionary process in a group of Y. pestis isolated from Brazil. We also identified specific genotypes of Y. pestis that were important for the establishment of the bacteria in plague foci in Brazil. The data have provided supporting evidence for the diversity and dynamics of CRISPR loci present in the genome of Y. pestis strains from plague foci in Brazil. PMID:25265542

  11. Foodborne pathogenic bacteria in prepackaged fresh retail portions of farmed rainbow trout and salmon stored at 3 degrees C.

    Science.gov (United States)

    González-Rodríguez, M N; Sanz, J J; Santos, J A; Otero, A; García-López, M L

    2002-06-05

    Twelve lots of fresh unskinned fillets of rainbow trout (Oncorhynchus mykiss) and 10 lots of fresh sliced salmon (Salmo salar) prepacked in trays wrapped with an oxygen-permeable film were obtained immediately after packing from two supermarkets having in-plant facilities for packaging wet fish. During storage at 3 degrees C, Listeria innocua was detected in eight lots of trout fillets after 4 days storage. L. monocytogenes was recovered from a single lot also contaminated with L. innocua. Initial numbers of aeromonads were significantly (p fish products, these bacteria significantly (p < 0.05) increased up until spoilage. Most Aeromonas spp. isolates from trout fillets were assigned to A. veronii biovar sobria HG8 (hybridisation group 8), A. caviae HG4, A. eucrenophila HG6, A. hydrophila HG1 and A. veronii biovar veronii HG10. Strains of HG12 (A. schubertii), HG4 and HG8 formed the majority of aeromonads recovered from salmon slices.

  12. SIDEROPHORE PRODUCING Pseudomonas AS PATHOGENIC Rhisoctonia solani AND Botrytis cinerea ANTAGONISTS

    Directory of Open Access Journals (Sweden)

    Martha Páez

    2005-06-01

    Full Text Available Pseudomonas aeruginosa, Pseudomonas putida biovar B, Pseudomonas marginalis y Burkholderia cepacia, aisladas de rizosfera y filosfera de plantas de rosa y alstroemeria, identificadas por ensayos bioquímicos y cultivadas en medio King B, mostraron propiedades antagónicas contra los patógenos (se usó medio PDA agar par el cultivo Rhizoctonia solani y Botrytis cinerea. Estas propiedades coincidieron con la presencia de un sideróforo, sustancia polar con bandas de absorción en 260 nm y 402 nm. Se observó incremento del crecimiento longitudinal de las plantas, medido sobre el tallo central, por influencia de P. putida biovar B, P. aeruginosa y P. marginalis. El crecimiento de rizomas (a: 0.05 fue notorio bajo la influencia de P. marginalis.

  13. TNF and PGE2 in human monocyte-derived macrophages infected with Chlamydia trachomatis

    Directory of Open Access Journals (Sweden)

    E. Manor

    1993-01-01

    Full Text Available In this study levels of prostaglandin E2 (PGE2, tumour necrosis factor (TNF and interleukin-1 (IL-1 alpha in medium from monocyte derived macrophages (MdM infected with Chlamydia trachomatis (L2/434/Bu or K biovars. TNF and PGE2 were found in both cases while IL-1 alpha was not detected. Both TNF and PGE2 levels were higher in the medium of the MdM infected with K biovars. TNF reached maximum levels 24 h postinfection, and then declined, while PGE2 levels increased continuously during the infection time up to 96 h post-infection. Addition of dexamethasone inhibited production of TNF and PGE2. Inhibition of PGE2 production by indomethacin resulted in increased production of TNF, while addition of PGE2 caused partial inhibition of TNF production from infected MdM.

  14. Identification of pioneer viridans streptococci in the oral cavity of human neonates.

    Science.gov (United States)

    Pearce, C; Bowden, G H; Evans, M; Fitzsimmons, S P; Johnson, J; Sheridan, M J; Wientzen, R; Cole, M F

    1995-01-01

    Three hundred and sixty-seven strains of pioneer streptococci isolated from the mouths of 40 healthy, full-term infants during the first month of life were examined by two taxonomic schemes that incorporated biochemical and physiological characteristics, IgA1 protease production and glycosidase activities. Streptococcus mitis biovar 1 and S. oralis comprised 55.0% of the pioneer streptococci isolated from neonates. S. salivarius constituted 25.3% of the isolates, while S. anginosus, S. mitis biovar 2, S. sanguis and S. gordonii accounted collectively for 11.4%. Difficulties in identifying streptococci were encountered and 8.4% of the 367 isolates could not be assigned to a recognised species.

  15. Brucellosis in nomadic pastoralists and their goats in two provinces of the eastern Algerian high plateaus.

    Science.gov (United States)

    Gabli, Abdelhafid; Agabou, Amir; Gabli, Zahra

    2015-08-01

    A 31-months study was conducted to elucidate the prevalence of brucellosis in nomadic pastoralists and their goats in two provinces of the eastern Algerian high plateaus. Five hundred eight human and 4955 animal sera were screened with the Rose Bengal plate test and the complement fixation test for confirmation. Uterine fluids from aborting goats were subjected to microbiological analyses to determine the biovars responsible for abortions. The overall seroprevalence was 0.98% among animals and 15.84% among herds. A significant correlation was recorded between occurrence of brucellosis and herd size (r = 0.4046, P Brucella melitensis biovar 3 was the only aetiology of brucellosis-associated abortion in goats of the studied region.

  16. Shewanella Oneidensis MR-1 Msh Pilin Proteins are Involved in Extracellular Electron Transfer in Microbial Fuel Cells

    Science.gov (United States)

    2011-01-01

    comparison of the 16 MR-1 Msh pilin complex proteins to Vibrio cholerae O1 biovar El Tor (tax id: 686) using the BLAST-search algorithm [21] for proteins... Vibrio cholerae mannose-sensitive hemagglutinin type 4 pilus gene locus. J Bacteriol 1999;181:1110–7. [23] Ringeisen BR, Henderson E, Wu PK...BLASTp) with default algorithm parameters. Sequence homology of MR-1 Msh proteins to the well-studied Msh pilin complex from V. cholera [22] allowed

  17. Determination of reactive oxygen generated from natural medicines and their antibacterial activity

    Directory of Open Access Journals (Sweden)

    Noriko Tajima

    2016-08-01

    Galla chinensis generated 2.4×10−4 mol/L hydrogen peroxide from a 1 mg/mL solution. In bacterial growth tests, Galla chinensis extract had antibacterial activity against Escherichia coli, Staphylococcus aureus, Bacteroides thetaiotaomicron, Campylobacter sputorum biovar sputorum, Streptococcus salivarius thermophilus, Lactobacillus casei, and Bifidobacterium longum infantis. This antibacterial activity was decreased by the addition of catalase. It revealed that hydrogen peroxide which Galla chinensis produced participated in antibacterial activity.

  18. Envolvimento de Aeromonas em surto de doença diarréica aguda em São Bento do Una, Pernambuco Aeromonas associated with an acute diarrhea outbreak in São Bento do Una, Pernambuco

    Directory of Open Access Journals (Sweden)

    Ernesto Hofer

    2006-04-01

    Full Text Available No primeiro semestre de 2004, ocorreu um surto de diarréia em São Bento do Una, Pernambuco, registrando-se 2.170 casos. Nas 582 coproculturas realizadas, 145 (25% revelaram um enteropatógeno bacteriano, destacando 114 casos (19,5% com a participação de Aeromonas, representadas por Aeromonas caviae (57/9,8%, Aeromonas veronii biovar sobria (23/3,9%, Aeromonas veronii biovar veronii (15/2,6% e outras espécies (19/3,2%. Nos 31 episódios restantes (5,3%, foram detectados: V. cholerae O1 Ogawa toxigênico (18/3,1%, Salmonella spp (8/1,4%, Shigella spp (3/0,5% e Vibrio cholerae não O1/não O139 (2/0,3%.An acute diarrhea outbreak, with 2170 cases, was described during January to July, 2004, in São Bento do Una, Pernambuco. 582 stools were examined and an enteric pathogen was recovered in 25% (145 patients. Aeromonas species were the most frequent (114-19.5% and the main isolates were Aeromonas caviae (57-9.8%, Aeromonas veronii biovar sobria (23-3.9%, Aeromonas veronii biovar veronii (15-2.6% and other species (19-3.2%. The other isolated enteropathogens were Vibrio cholerae O1-Ogawa toxigenic (18-3.1%, Salmonella spp (8-1.4%, Shigella spp (3-0.5% and Vibrio cholerae non-O1/non-O139 (2-0.3%.

  19. Infections following the application of leeches: two case reports and review of the literature

    Directory of Open Access Journals (Sweden)

    Maetz Benjamin

    2012-10-01

    Full Text Available Abstract Introduction Since the 1980s, leeches have been ingeniously used in the management of venous flap congestion. The presence of anticoagulative substances in their saliva improves the blood drainage. Their digestive tract contains several bacterial species, the main ones being Aeromonas hydrophila and Aeromonas veronii biovar sobria, which contribute to the digestion of ingested blood. These bacteria can be the cause of infections. Case presentation We report two cases of septicemia related to Aeromonas veronii biovar sobria that presented after leeches had been applied to congested transverse rectus abdominis myocutaneous flaps for delayed mammary reconstructions. Patient number 1 was a 55-year-old Caucasian woman who underwent a delayed breast reconstruction procedure. On the sixth postoperative day she showed a clinical presentation of septicemia. Aeromonas veronii biovar sobria was identified in the patient’s skin and blood bacteriological samples. Her fever ceased after 4 days of antibiotic treatment. Patient number 2 was a 56-year-old Caucasian woman who underwent a delayed breast reconstruction procedure. On the seventh postoperative day we noticed that she showed a clinical presentation of septicemia. Aeromonas veronii biovar sobria was identified in the patient’s blood cultures and local bacteriological samples. An antibiogram showed resistance to amoxicillin/clavulanic acid. Her fever ceased on the eleventh postoperative day after 4 days of antibiotic treatment. Conclusion The rate of infection after application of leeches is not negligible. The concentration of Aeromonas inside the digestive tracts of leeches largely decreases when the patient is under antibiotic therapy. These germs are sensitive to third-generation cephalosporins and fluoroquinolones and resistant to amoxicillin/clavulanic acid. We recommend preventive treatment based on classical measures of asepsis and on oral antibioprophylaxy with a fluoroquinolone

  20. Evaluation of Cholera Toxin Expression in Different Populations of Vibrio cholera

    OpenAIRE

    Sedigheh Ebrahimi Kasgari; Mahnaz Nourani; Yousef Yahyapour; Seyed Ehsanollah Mousavi; Enayatollah Kalantar; Hami Kaboosi (PhD); Seyed Mahmoud Amin Marashi

    2015-01-01

    Background: Cholera is one of the most diseases of human. Cholera toxin is the most important pathogenic factor in humans that causes diarrhea. The cholera toxin is produced by V. cholerae and CTXфPhage. Objectives: In this study, we have investigated the production cholera toxin with different density of Vibrio cholerae. Materials and Methods: With this propose we inoculated classical strain O1 of Vibrio cholerae ATCC 14035 and Vibrio cholerae O1biovar El Tor N16961 into th...

  1. Identification and determination of antibiotic susceptibilities of Brucella strains isolated from patients in van, Turkey by conventional and molecular methods.

    Science.gov (United States)

    Parlak, Mehmet; Güdücüoğlu, Hüseyin; Bayram, Yasemin; Çıkman, Aytekin; Aypak, Cenk; Kılıç, Selçuk; Berktaş, Mustafa

    2013-01-01

    Brucellosis is a worldwide zoonotic disease and still constitutes a major public health problem. In this study, we aimed to identify biovars of Brucella strains isolated from clinical specimens taken from brucellosis patients from the Eastern Anatolia region as well determine the susceptibility of these isolates to tigecycline and azithromycin, drugs that may serve as alternatives to the conventional drugs used in the therapy. Seventy-five Brucella spp. isolates were included in the study. All strains were identified by both conventional and molecular methods. Brucella Multiplex PCR kit (FC-Biotech, Code: 0301, Turkey) and B. melitensis biovar typing PCR kit (FC-Biotech, Code: 0302, Turkey) were used for molecular typing. Antimicrobial susceptibilities of all strains were determined by E-tests. By conventional biotyping, 73 strains were identified as B. melitensis biovar 3 and two strains as B. abortus biovar 3. Molecular typing results were compatible with conventional methods. The MIC50 and MIC90 values of doxycycline were 0.047 and 0.094; tigecycline 0.094 and 0.125; trimethoprim/sulfamethoxazole 0.064 and 0.19; ciprofloxacin 0.19 for both; streptomycin 0.75 and 1; rifampin 1 and 2 and azithromycin 4 and 8. According to the MIC values, doxycycline was found to be the most effective antibiotic, followed by tigecycline, trimethoprim-sulfamethoxazole and ciprofloxacin. Currently recommended antibiotics for the treatment of brucellosis such as doxycycline, rifampin, streptomycin, trimethoprim-sulfamethoxazole and ciprofloxacin were found to be still effective. While our results showed that tigecycline can be used an alternative agent in the treatment of brucellosis, azithromycin has not been confirmed as an appropriate agent for the treatment.

  2. Phenotypical characteristics, genetic identification, and antimicrobial sensitivity of Aeromonas species isolated from farmed rainbow trout (Onchorynchus mykiss) in Mexico.

    Science.gov (United States)

    Vega-Sánchez, Vicente; Acosta-Dibarrat, Jorge; Vega-Castillo, Fernando; Castro-Escarpulli, Graciela; Aguilera-Arreola, Ma Guadalupe; Soriano-Vargas, Edgardo

    2014-02-01

    In the present study, Aeromonas isolates from diseased and healthy farmed rainbow trout (Oncorhynchus mykiss) in Mexico, were characterized phenotypically and identified to species level by using 16S rDNA RFLP-PCR. A total of 50 isolates were included in the study and 10 Aeromonas species identified. The species A. veronii biovar sobria (22%), A. hydrophila (20%) and A. bestiarum (20%) were the most predominant. All isolates (100%) were resistant to cephalothin.

  3. Complete Genome Sequence of Yersinis pestis Strains Antiqua and Nepa1516: Evidence of Gene Reduction in an Emerging Pathogen

    Energy Technology Data Exchange (ETDEWEB)

    Chain, Patrick S [ORNL; Hu, Ping [Lawrence Berkeley National Laboratory (LBNL); Malfatti, Stephanie [Lawrence Livermore National Laboratory (LLNL); Radnedge, Lyndsay [Lawrence Livermore National Laboratory (LLNL); Larimer, Frank W [ORNL; Vergez, Lisa [Lawrence Livermore National Laboratory (LLNL); Worsham, Patricia [U.S. Army Medical Research Institute of Infectious Diseases; Chu, May C [Centers for Disease Control and Prevention; Anderson, Gary L [Lawrence Berkeley National Laboratory (LBNL)

    2006-01-01

    Yersinia pestis, the causative agent of bubonic and pneumonic plagues, has undergone detailed study at the molecular level. To further investigate the genomic diversity among this group and to help characterize lineages of the plague organism that have no sequenced members, we present here the genomes of two isolates of the ''classical'' antiqua biovar, strains Antiqua and Nepal516. The genomes of Antiqua and Nepal516 are 4.7 Mb and 4.5 Mb and encode 4,138 and 3,956 open reading frames, respectively. Though both strains belong to one of the three classical biovars, they represent separate lineages defined by recent phylogenetic studies. We compare all five currently sequenced Y. pestis genomes and the corresponding features in Yersinia pseudotuberculosis. There are strain-specific rearrangements, insertions, deletions, single nucleotide polymorphisms, and a unique distribution of insertion sequences. We found 453 single nucleotide polymorphisms in protein-coding regions, which were used to assess the evolutionary relationships of these Y. pestis strains. Gene reduction analysis revealed that the gene deletion processes are under selective pressure, and many of the inactivations are probably related to the organism's interaction with its host environment. The results presented here clearly demonstrate the differences between the two biovar antiqua lineages and support the notion that grouping Y. pestis strains based strictly on the classical definition of biovars (predicated upon two biochemical assays) does not accurately reflect the phylogenetic relationships within this species. A comparison of four virulent Y. pestis strains with the human-avirulent strain 91001 provides further insight into the genetic basis of virulence to humans.

  4. Mitochondrial genome sequences reveal evolutionary relationships of the Phytophthora 1c clade species.

    Science.gov (United States)

    Lassiter, Erica S; Russ, Carsten; Nusbaum, Chad; Zeng, Qiandong; Saville, Amanda C; Olarte, Rodrigo A; Carbone, Ignazio; Hu, Chia-Hui; Seguin-Orlando, Andaine; Samaniego, Jose A; Thorne, Jeffrey L; Ristaino, Jean B

    2015-11-01

    Phytophthora infestans is one of the most destructive plant pathogens of potato and tomato globally. The pathogen is closely related to four other Phytophthora species in the 1c clade including P. phaseoli, P. ipomoeae, P. mirabilis and P. andina that are important pathogens of other wild and domesticated hosts. P. andina is an interspecific hybrid between P. infestans and an unknown Phytophthora species. We have sequenced mitochondrial genomes of the sister species of P. infestans and examined the evolutionary relationships within the clade. Phylogenetic analysis indicates that the P. phaseoli mitochondrial lineage is basal within the clade. P. mirabilis and P. ipomoeae are sister lineages and share a common ancestor with the Ic mitochondrial lineage of P. andina. These lineages in turn are sister to the P. infestans and P. andina Ia mitochondrial lineages. The P. andina Ic lineage diverged much earlier than the P. andina Ia mitochondrial lineage and P. infestans. The presence of two mitochondrial lineages in P. andina supports the hybrid nature of this species. The ancestral state of the P. andina Ic lineage in the tree and its occurrence only in the Andean regions of Ecuador, Colombia and Peru suggests that the origin of this species hybrid in nature may occur there.

  5. Biodiversity and biogeography of rhizobia associated with common bean (Phaseolus vulgaris L.) in Shaanxi Province.

    Science.gov (United States)

    Wang, Li; Cao, Ying; Wang, En Tao; Qiao, Ya Juan; Jiao, Shuo; Liu, Zhen Shan; Zhao, Liang; Wei, Ge Hong

    2016-05-01

    The biodiversity and biogeography of rhizobia associated with bean in Shaanxi Province were investigated. A total of 194 bacterial isolates from bean nodules collected from 13 sampling sites were characterized based on phylogenetic analyses of the 16S rRNA gene, the housekeeping genes recA, glnII and atpD, and the symbiotic genes nodC and nifH. Fifteen genospecies belonging to the genera Rhizobium, Agrobacterium, Ensifer, Bradyrhizobium and Ochrobactrum were defined among the isolates, with Rhizobium sp. II, Agrobacterium sp. II, E. fredii and R. phaseoli being the dominant groups. Four symbiotic gene lineages corresponding to Rhizobium sp. I, Rhizobium sp. II, R. phaseoli and B. liaoningense were detected in the nodC and nifH sequence analyses, indicating different origins for the symbiotic genes and their co-evolution with the chromosome of the bacteria. Moreover, the Ensifer isolates harbored symbiotic genes closely related to bean-nodulating Pararhizobium giardinii, indicating possible lateral gene transfer from Rhizobium to Ensifer. Correlation of rhizobial community composition with moisture, temperature, intercropping, soil features and nutrients were detected. All the results demonstrated a great diversity of bean rhizobia in Shaanxi that might be due to the adaptable evolution of the bean-nodulating rhizobia subjected to the diverse ecological conditions in the area.

  6. Etiology of phomopsis root rot in soybean

    Directory of Open Access Journals (Sweden)

    Valéria Cecília Ghissi

    2014-09-01

    Full Text Available In a survey of damages caused by soybean root rot to crops in the south of Brazil for several years, a root rot caused by Phomopsis sp has been found with increasing frequency. The primary symptoms are seen when the main root is cut longitudinally, including the death of the wood which shows white coloration and well-defined black lines that do not have a defined format. Thus, based on similarity, it has been called geographic root rot due to its aspect resembling irregular lines that separate regions on a map. In isolations, colonies and alpha spores of Phomopsis have prevailed. Pathogenicity test was done by means of inoculation in the crown of plants cultivated in a growth chamber. The geographic symptoms were reproduced in plants and the fungus Phomopsis sp. was reisolated. In soybean stems naturally infected with pod and stem blight, geographic symptoms caused by Phomopsis phaseoli are found. To the known symptoms on stems, pods and grains, that of root rot caused by P. phaseoli is now added.

  7. Antibacterial activity of essential oil components and their potential use in seed disinfection.

    Science.gov (United States)

    Lo Cantore, Pietro; Shanmugaiah, Vellasamy; Iacobellis, Nicola Sante

    2009-10-28

    Among the main (> or = 0.7%) components of some essential oils, considerable antibacterial activity was shown by terpenoid and phenylpropanoid derivatives containing phenol and alcohol functionalities. A reduced or no activity was shown by those derivatives containing ketones, aldehydes, ethers, and ester functionalities as well as the remaining terpenoids. Eugenol emulsion treatments (1-8 mg/mL) of bean seeds bearing about 2.6 x 10(6) cfu/seed of strain ICMP239 of Xanthomonas campestris pv. phaseoli var. fuscans determined a highly significant reduction of the bacteria on seeds. In particular, eugenol at 4 mg/mL disinfect seeds bearing about 7.0 x 10(2) cfu/seed and lower densities. However, after 72 h, incubation treatments with 2, 4, and 8 mg/mL of eugenol caused germination reduction of 3%, 7%, and 16%, respectively, which was significantly different from the controls. No effect on germination was observed with 1 mg/mL eugenol emulsion treatment. These data indicate eugenol as potentially useful for bean seed disinfection from X. campestris pv. phaseoli var. fuscans. Further studies on the effects on seed vitality and on formulation of essential oils are needed.

  8. Toxicity of twenty-two plant essential oils against pathogenic bacteria of vegetables and mushrooms.

    Science.gov (United States)

    Todorović, Biljana; Potočnik, Ivana; Rekanović, Emil; Stepanović, Miloš; Kostić, Miroslav; Ristić, Mihajlo; Milijašević-Marčić, Svetlana

    2016-12-01

    ASBTRACT Toxicity of twenty-two essential oils to three bacterial pathogens in different horticultural systems: Xanthomonas campestris pv. phaseoli (causing blight of bean), Clavibacter michiganensis subsp. michiganensis (bacterial wilt and canker of tomato), and Pseudomonas tolaasii (causal agent of bacterial brown blotch on cultivated mushrooms) was tested. Control of bacterial diseases is very difficult due to antibiotic resistance and ineffectiveness of chemical products, to that essential oils offer a promising alternative. Minimal inhibitory and bactericidal concentrations are determined by applying a single drop of oil onto the inner side of each plate cover in macrodilution assays. Among all tested substances, the strongest and broadest activity was shown by the oils of wintergreen (Gaultheria procumbens), oregano (Origanum vulgare), and lemongrass (Cymbopogon flexuosus. Carvacrol (64.0-75.8%) was the dominant component of oregano oils, while geranial (40.7%) and neral (26.7%) were the major constituents of lemongrass oil. Xanthomonas campestris pv. phaseoli was the most sensitive to plant essential oils, being susceptible to 19 oils, while 11 oils were bactericidal to the pathogen. Sixteen oils inhibited the growth of Clavibacter michiganensis subsp. michiganensis and seven oils showed bactericidal effects to the pathogen. The least sensitive species was Pseudomonas tolaasii as five oils inhibited bacterial growth and two oils were bactericidal. Wintergreen, oregano, and lemongrass oils should be formulated as potential biochemical bactericides against different horticultural pathogens.

  9. Sexual recombination in Colletotrichum lindemuthianum occurs on a fine scale.

    Science.gov (United States)

    Souza, E A; Camargo, O A; Pinto, J M A

    2010-09-08

    Glomerella cingulata f. sp phaseoli is the sexual phase of the fungus Colletotrichum lindemuthianum, the causal agent of common bean anthracnose. This fungus is of great concern, because it causes large economic losses in common bean crops. RAPD markers of five populations of G. cingulata f. sp phaseoli from two Brazilian states were analyzed to determine if this population possesses the sexual reproductive potential to generate the genetic variation that is observed in this phytopathogen. We identified 128 polymorphic bands, amplified by 28 random primers. The estimates of genetic similarity in this analysis ranged from 0.43 to 1.00, and the dendrogram generated from analysis of all genotypes displayed five principal groups, coinciding with the five populations. Genetic differentiation was observed between the populations (GST=0.6455); 69% of the overall observed genetic variation was between individual populations and 31% of the variance was within the sub-populations. We identified significant levels of linkage disequilibrium in all populations. However, the values of the disequilibrium ranged from low to moderate, indicating that this pathogen maintains a genetic structure consistent with sexual reproduction. The mean contribution of sexual reproduction was determined by comparison of the amplitudes of genetic similarity of isolates from sexual and asexual phases. These results support the hypothesis that recombination plays an important role in determining the amplitude of variability in this pathogen population and that this determination occurs on a fine scale.

  10. Isolation and identification of bovine Brucella isolates from Pakistan by biochemical tests and PCR.

    Science.gov (United States)

    Ali, Shahzad; Ali, Qurban; Melzer, Falk; Khan, Iahtasham; Akhter, Shamim; Neubauer, Heinrich; Jamal, Syed M

    2014-01-01

    Brucellosis is endemic in bovines in Pakistan. The Brucella species and biovars involved, however, are unknown. The objectives of the present study were to isolate and characterize brucellae from seropositive milk samples, aborted fetuses, and vaginal swabs of cattle and buffaloes which had recently aborted. The seropositive milk samples, aborted fetuses, and vaginal swabs of cattle and buffaloes were collected from the Potohar Plateau, Pakistan. Isolation of brucellae was done on modified Farrell's serum dextrose agar. Isolates were characterized by conventional biotyping methods, while molecular typing was done by genus (B4/B5) and species-specific (Brucella abortus, Brucella melitensis, Brucella ovis, and Brucella suis) polymerase chain reaction (PCR). A total of 30 isolates were recovered from milk (n = 5), aborted fetuses (n = 13), and vaginal swabs (n = 12). Most isolates were from cattle (56.7 %). All of them were identified as B. abortus biovar 1 based on conventional biotyping methods and genus and species-specific PCR. This preliminary study provides the first report on the prevalence of B. abortus biovar 1 in cattle and buffaloes in Pakistan.

  11. [An evaluation of the effectiveness of laboratory diagnostic methods for brucellosis].

    Science.gov (United States)

    Gandara, B; Zheludkov, M M; Chernysheva, M I

    1994-01-01

    The diagnostic value of bacteriological and serological methods for the laboratory diagnosis of brucellosis was studied. In the analysis of milk and cheese specimens Brucella cultures were isolated and differentiated as B.melitensis, biovar I, and B.abortus, biovar 4. In 25.6% of cases B.melitensis culture, biovar 1, was isolated from the blood of persons suspected for brucellosis. The isolation of B.melitensis culture from milk showed that this infective agent migrated from small animals to cattle, which was indicative of a high risk of human infection in the state of Zacatecas, Mexico. The comparative evaluation of serological diagnostic methods (the agglutination test in test tubes, Huddleson's slide test, the acidic rose bengal test and the 2-mercaptoethanol test) showed high sensitivity of rapid tests (Huddleson's test and the rose bengal test in 93.7% and 87.9% of cases respectively). The 2-mercaptoethanol test which gave positive results in 63.8% of cases provided additional information characterizing the course of infections process.

  12. Complete Genome Sequence of Yersinia pestis Strains Antiqua andNepal516: Evidence of Gene Reduction in an Emerging Pathogen

    Energy Technology Data Exchange (ETDEWEB)

    Chain, Patrick S.G.; Hu, Ping; Malfatti, Stephanie A.; Radnedge,Lyndsay; Larimer, Frank; Vergez, Lisa M.; Worsham, Patricia; Chu, May C.; Andersen, Gary L.

    2006-01-16

    Yersinia pestis, the causative agent of bubonic andpneumonicplague, has undergone detailed study at the molecular level. Tofurther investigate the genomic diversity among this group and to helpcharacterize lineages of the plague organism that have no sequencedmembers, we present here the genomes of two isolates of the "classical"Antiqua biovar, strains Antiqua and Nepal516. The genomes of Antiqua andNepal516 are 4.7 Mb and 4.5 Mb and encode 4,138 and 3,956 open readingframes respectively. Though both strains belong to one of the threeclassical biovars, they represent separate lineages defined by recentphylogenetic studies. We compare all five currently sequenced Y. pestisgenomes and the corresponding features in Y. pseudotuberculosis. Thereare strain-specific rearrangements, insertions, deletions, singlenucleotide polymorphisms and a unique distribution of insertionsequences. We found 453 single nucleotide polymorphisms in protein codingregions, which were used to assess evolutionary relationships of these Y.pestis strains. Gene reduction analysis revealed that the gene deletionprocesses are under selective pressure and many of the inactivations areprobably related to the organism s interaction with its host environment.The results presented here clearly demonstrate the differences betweenthe two Antiqua lineages and support the notion that grouping Y. pestisstrains based strictly on the classical definition of biovars (predicatedupon two biochemical assays) does not accurately reflect the phylogeneticrelationships within this species. Comparison of four virulent Y. pestisstrains with the human-avirulent strain 91001 provides further insightinto the genetic basis of virulence to humans.

  13. Assessment of Genetic Diversity of Zoonotic Brucella spp. Recovered from Livestock in Egypt Using Multiple Locus VNTR Analysis

    Directory of Open Access Journals (Sweden)

    Ahmed M. S. Menshawy

    2014-01-01

    Full Text Available Brucellosis is endemic in most parts of Egypt, where it is caused mainly by Brucella melitensis biovar 3, and affects cattle and small ruminants in spite of ongoing efforts devoted to its control. Knowledge of the predominant Brucella species/strains circulating in a region is a prerequisite of a brucellosis control strategy. For this reason a study aiming at the evaluation of the phenotypic and genetic heterogeneity of a panel of 17 Brucella spp. isolates recovered from domestic ruminants (cattle, buffalo, sheep, and goat from four governorates during a period of five years (2002–2007 was carried out using microbiological tests and molecular biology techniques (PCR, MLVA-15, and sequencing. Thirteen strains were identified as B. melitensis biovar 3 while all phenotypic and genetic techniques classified the remaining isolates as B. abortus (n=2 and B. suis biovar 1 (n=2. MLVA-15 yielded a high discriminatory power (h=0.801, indicating a high genetic diversity among the B. melitensis strains circulating among domestic ruminants in Egypt. This is the first report of the isolation of B. suis from cattle in Egypt which, coupled with the finding of B. abortus, suggests a potential role of livestock as reservoirs of several zoonotic Brucella species in the region.

  14. Assessment of genetic diversity of zoonotic Brucella spp. recovered from livestock in Egypt using multiple locus VNTR analysis.

    Science.gov (United States)

    Menshawy, Ahmed M S; Perez-Sancho, Marta; Garcia-Seco, Teresa; Hosein, Hosein I; García, Nerea; Martinez, Irene; Sayour, Ashraf E; Goyache, Joaquín; Azzam, Ragab A A; Dominguez, Lucas; Alvarez, Julio

    2014-01-01

    Brucellosis is endemic in most parts of Egypt, where it is caused mainly by Brucella melitensis biovar 3, and affects cattle and small ruminants in spite of ongoing efforts devoted to its control. Knowledge of the predominant Brucella species/strains circulating in a region is a prerequisite of a brucellosis control strategy. For this reason a study aiming at the evaluation of the phenotypic and genetic heterogeneity of a panel of 17 Brucella spp. isolates recovered from domestic ruminants (cattle, buffalo, sheep, and goat) from four governorates during a period of five years (2002-2007) was carried out using microbiological tests and molecular biology techniques (PCR, MLVA-15, and sequencing). Thirteen strains were identified as B. melitensis biovar 3 while all phenotypic and genetic techniques classified the remaining isolates as B. abortus (n = 2) and B. suis biovar 1 (n = 2). MLVA-15 yielded a high discriminatory power (h = 0.801), indicating a high genetic diversity among the B. melitensis strains circulating among domestic ruminants in Egypt. This is the first report of the isolation of B. suis from cattle in Egypt which, coupled with the finding of B. abortus, suggests a potential role of livestock as reservoirs of several zoonotic Brucella species in the region.

  15. Production and characterization of monoclonal antibodies against Campylobacter fetus subsp. venerealis

    Directory of Open Access Journals (Sweden)

    Telma M. Alves

    2012-07-01

    Full Text Available Myeloma cells Sp2/0-Ag14 and spleen cells from BALB/c mouse immunized with sonicated Campylobacter fetus subsp. venerealis NCTC 10354 were fused with polyethylene glycol (PEG for the selection of clones producing antibodies. Clones were obtained by limiting dilution and screened for the production of specific antibodies to C. fetus subsp. venerealis NCTC 10354 by indirect ELISA and western blot against a panel of bacteria: C. fetus subsp. venerealis NCTC 10354, C. fetus subsp fetus ADRI 1812, C. sputorum biovar sputorum LMG 6647, C. lari NCTC 11352, and Arcobacter skirrowii LMG 6621 for the ELISA and C. fetus subsp. venerealis NCTC 10354 and C. sputorum biovar sputorum LMG 6647 for the western blotting. Fifteen clones producing monoclonal antibodies (MAbs anti-C. fetus subsp. venerealis of the IgM (1 and IgG (14 classes were further screened for species-specificity. Four clones of the 15 obtained were producers of species-specific monoclonal antibodies (MAbs: two were specific for C. fetus subsp. venerealis and two were specific for C. fetus subsp. fetus. None of the clones were reactive against C. sputorum biovar sputorum LMG 6647. All clones recognized a protein with molecular mass of approximately 148 kDa from lysed C. fetus subsp. venerealis NCTC 10354.

  16. Natural variation in host-specific nodulation of pea is associated with a haplotype of the SYM37 LysM-type receptor-like kinase.

    Science.gov (United States)

    Li, Ronghui; Knox, Maggie R; Edwards, Anne; Hogg, Bridget; Ellis, T H Noel; Wei, Gehong; Downie, J Allan

    2011-11-01

    Rhizobium leguminosarum bv. viciae, which nodulates pea and vetch, makes a mixture of secreted nodulation signals (Nod factors) carrying either a C18:4 or a C18:1 N-linked acyl chain. Mutation of nodE blocks the formation of the C18:4 acyl chain, and nodE mutants, which produce only C18:1-containing Nod factors, are less efficient at nodulating pea. However, there is significant natural variation in the levels of nodulation of different pea cultivars by a nodE mutant of R. leguminosarum bv. viciae. Using recombinant inbred lines from two pea cultivars, one which nodulated relatively well and one very poorly by the nodE mutant, we mapped the nodE-dependent nodulation phenotype to a locus on pea linkage group I. This was close to Sym37 and PsK1, predicted to encode LysM-domain Nod-factor receptor-like proteins; the Sym2 locus that confers Nod-factor-specific nodulation is also in this region. We confirmed the map location using an introgression line carrying this region. Our data indicate that the nodE-dependent nodulation is not determined by the Sym2 locus. We identified several pea lines that are nodulated very poorly by the R. leguminosarum bv. viciae nodE mutant, sequenced the DNA of the predicted LysM-receptor domains of Sym37 and PsK1, and compared the sequences with those derived from pea cultivars that were relatively well nodulated by the nodE mutant. This revealed that one haplotype (encoding six conserved polymorphisms) of Sym37 is associated with very poor nodulation by the nodE mutant. There was no such correlation with polymorphisms at the PsK1 locus. We conclude that the natural variation in nodE-dependent nodulation in pea is most probably determined by the Sym37 haplotype.

  17. Genetic diversity of Rhizobium from nodulating beans grown in a variety of Mediterranean climate soils of Chile.

    Science.gov (United States)

    Baginsky, Cecilia; Brito, Belén; Scherson, Rosita; Pertuzé, Ricardo; Seguel, Oscar; Cañete, Alejandro; Araneda, Cristian; Johnson, Warren E

    2015-04-01

    In spite of potentially being an important source of rhizobial diversity and a key determinant of common bean productivity, there is a paucity of data on Rhizobium genetic variation and species composition in the important bean producing area of Chile and only one species has been documented (Rhizobium leguminosarum). In this study, 240 Rhizobium isolates from Torcaza bean (Phaseolus vulgaris L.) nodules established in the highest bean producing area in Chile (33°34'S-70°38'W and 37°36'S-71°47'W) were characterized by PCR-RFLP markers for nodC gene, revealing eight banding patterns with the polymorphic enzyme Hinf I. The locality of San Agustín de Aurora in Central Chile (35°32'S-71°29'W) had the highest level of diversity. Isolates were classified by species using PCR-RFLP markers for 16S rDNA gene and were confirmed by sequencing an internal fragment of the 16S rDNA gene. The results confirmed the presence of R. leguminosarum and three other species of rhizobia nodulating beans in South Central Chile (R. etli, R. tropici and R. leucaenae). R. tropici and R. leucaenae showed the least genetic variation and were most commonly identified in acid soils, while R. etli was the most common species in slightly acidic to moderately alkaline soils, with higher levels of organic matter content. R. leguminosarum was identified in almost all soils, was the most genetically diverse, and was the most common, being documented in soils with pH that ranged between 5.3 and 8.2, and with organic matter content between 2.1 and 4 %.

  18. Strain identification in Rhizobium by starch gel electrophoresis of isoenzymes

    DEFF Research Database (Denmark)

    Engvild, Kjeld Christensen; Nielsen, G.

    1985-01-01

    Sonieated extracts of rhizobia, especiaUy Rhizobium leguminosarum from pea and vetch, were run in horizontal starch gel electrophoresis in the cold. The rhizobia were grown on agar on a slime suppressing substrate of tryptone-yeast extract-CaCl2 with small amounts of mannitol, sorbitol...... and arabinose and other sugars as enzyme inducers. After electrophoresis the gels were separated into several slabs by a gel cutter. Each slab was stained for a particular enzyme. Among numerous enzyme systems tested we found useful variation in esterases (EC 3.1.1.1, EC 3.1.1.2), 3-hydroxybutyrate...

  19. Auxin and nitric oxide control indeterminate nodule formation

    Directory of Open Access Journals (Sweden)

    Spena Angelo

    2007-05-01

    Full Text Available Abstract Background Rhizobia symbionts elicit root nodule formation in leguminous plants. Nodule development requires local accumulation of auxin. Both plants and rhizobia synthesise auxin. We have addressed the effects of bacterial auxin (IAA on nodulation by using Sinorhizobium meliloti and Rhizobium leguminosarum bacteria genetically engineered for increased auxin synthesis. Results IAA-overproducing S. meliloti increased nodulation in Medicago species, whilst the increased auxin synthesis of R. leguminosarum had no effect on nodulation in Phaseolus vulgaris, a legume bearing determinate nodules. Indeterminate legumes (Medicago species bearing IAA-overproducing nodules showed an enhanced lateral root development, a process known to be regulated by both IAA and nitric oxide (NO. Higher NO levels were detected in indeterminate nodules of Medicago plants formed by the IAA-overproducing rhizobia. The specific NO scavenger cPTIO markedly reduced nodulation induced by wild type and IAA-overproducing strains. Conclusion The data hereby presented demonstrate that auxin synthesised by rhizobia and nitric oxide positively affect indeterminate nodule formation and, together with the observation of increased expression of an auxin efflux carrier in roots bearing nodules with higher IAA and NO content, support a model of nodule formation that involves auxin transport regulation and NO synthesis.

  20. Genetic diversity of root-nodulating bacteria isolated from pea (Pisum sativum) in subtropical regions of China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Diversity of 42 isolates from effective nodules of Pisum sativum in different geographical regions of China were studied using 16S rRNA gene RFLP patterns, 16S rRNA sequencing, 16S–23S rRNA inter-genic spacer (IGS) region RFLP patterns and G-C rich random amplified polymorphic DNA (RAPD). The isolates were distributed in two groups on the basis of their 16S rRNA gene RFLP patterns. The 16S rRNA gene sequences of strains from 16S rRNA gene RFLP patterns group I were very closely related (identities higher than 99.5%) to Rhizobium leguminosarum USDA 2370. Group II consisting of WzP3 and WzP15 was closely related to Rhizobium etli CFN42. The analysis of the 16S–23S IGS RFLP pat-terns divided the isolates into 18 genotypes and four groups. Group I was clustered with R. legumino-sarum USDA2370. Group II consisted of YcP2, YcP3 and CqP7. The strains of group III were distributed abroad. Group IV consisted of WzP3, WzP15 and R. etli CFN42. RAPD divided the isolates into nine clusters in which group IV only consisted of YcP2 and the strains of group V and IX were from Wenzhou and Xiantao, respectively. This assay demonstrated the geographical effect on genetic diversity of pea rhizobia.

  1. A new sand pouch-plant infection technique for enumeration of rhizobia in soil

    Directory of Open Access Journals (Sweden)

    Stefan Martyniuk

    2014-01-01

    Full Text Available A sand pouch-plant infection technique for counting most probable numbers of rhizobia in soil is described. Populations of Rhizobium leguminosarum bv. trifoli detected by the plant infection method performed in enclosed glass tubes or in sand pouches did not differ significantly. The described method was used to assess numbers of R. leguminosarum bv. trifoli (R.l.t. and bv. viciae (R.l.v. in 20 soils of Poland. Logarithms of the populations of R.l.t. in the tested soils ranged from not detectable level to 4.76 and those of R.l.v. from 2.23 to 5.84 in g1 of soil dry mass. Numbers of R.l.t. were significantly correlated with soil clay, C org, and total N contents but not with the soil pH (in KCI, while numbers of R.l.v. showed significant correlation only with the soil pH.

  2. Genetic Diversity and Symbiotic Phenotype of Hairy Vetch Rhizobia in Japan.

    Science.gov (United States)

    Yuan, Kun; Miwa, Hiroki; Iizuka, Maki; Yokoyama, Tadashi; Fujii, Yoshiharu; Okazaki, Shin

    2016-06-25

    Hairy vetch (Vicia villosa Roth) is a leguminous crop widely used as green manure and a cover crop in Japan. It exhibits strong weed-suppressing activity, high resistance to insect pests, and the ability to fix nitrogen through symbiotic interactions with soil bacteria known as rhizobia. Few studies have investigated the rhizobia that form nodules on hairy vetch in Japan, and the biological resources available for selecting high nitrogen-fixing rhizobia are limited. In the present study, we isolated 110 hairy vetch rhizobia from 13 different areas in Japan. Based on their 16S rRNA gene sequences, 73% of the isolates were identified as Rhizobium leguminosarum. A comparative analysis of nodC and 16S rRNA gene phylogenies revealed that several isolates possessed congruent nodC sequences despite having divergent 16S rRNA gene sequences, suggesting that the horizontal transfer of nod genes occurred during the evolution of rhizobia. Inoculation tests showed that isolates closely related to R. leguminosarum had better plant growth-promoting effects than other strains, thereby providing a promising agricultural resource for inoculating crops.

  3. Molecular diversity and phylogeny of rhizobia associated with Lablab purpureus (Linn.) grown in Southern China.

    Science.gov (United States)

    Chang, Yue Li; Wang, En Tao; Sui, Xin Hua; Zhang, Xiao Xia; Chen, Wen Xin

    2011-06-01

    As an introduced plant, Lablab purpureus serves as a vegetable, herbal medicine, forage and green manure in China. In order to investigate the diversity of rhizobia associated with this plant, a total of 49 rhizobial strains isolated from ten provinces of Southern China were analyzed in the present study with restriction fragment length polymorphism and/or sequence analyses of housekeeping genes (16S rRNA, IGS, atpD, glnII and recA) and symbiotic genes (nifH and nodC). The results defined the L. purpureus rhizobia as 24 IGS-types within 15 rrs-IGS clusters or genomic species belonging to Bradyrhizobium, Rhizobium, Ensifer (synonym of Sinorhizobium) and Mesorhizobium. Bradyrhizobium spp. (81.6%) were the most abundant isolates, half of which were B. elkanii. Most of these rhizobia induced nodules on L. purpureus, but symbiotic genes were only amplified from the Bradyrhizobium and Rhizobium leguminosarum strains. The nodC and nifH phylogenetic trees defined five lineages corresponding to B. yuanmingense, B. japonicum, B. elkanii, B. jicamae and R. leguminosarum. The coherence of housekeeping and symbiotic gene phylogenies demonstrated that the symbiotic genes of the Lablab rhizobia were maintained mainly through vertical transfer. However, a putative lateral transfer of symbiotic genes was found in the B. liaoningense strain. The results in the present study clearly revealed that L. purpureus was a promiscuous host that formed nodules with diverse rhizobia, mainly Bradyrhizobium species, harboring different symbiotic genes.

  4. Genetic diversity of root-nodulating bacteria isolated from pea (Pisum sativum) in subtropical regions of China

    Institute of Scientific and Technical Information of China (English)

    YANG ChengYun; YANG JiangKe; LI YouGuo; ZHOU JunOhu

    2008-01-01

    Diversity of 42 isolates from effective nodules of Pisum sativum in different geographical regions of China were studied using 16S rRNA gene RFLP patterns, 16S rRNA sequencing, 16S-23S rRNA inter-genic spacer (IGS) region RFLP patterns and G-C rich random amplified polymorphic DNA (RAPD). The isolates were distributed in two groups on the basis of their 16S rRNA gene RFLP patterns. The 16S rRNA gene sequences of strains from 16S rRNA gene RFLP patterns group Ⅰ were very closely related (identities higher than 99.5%) to Rhizobium leguminosarum USDA 2370. Group Ⅱ consisting of WzP3 and WzP15 was closely related to Rhizobium etli CFN42. The analysis of the 16S-23S IGS RFLP pat-terns divided the isolates into 18 genotypes and four groups. Group Ⅰ was clustered with R. legumino-sarum USDA2370. Group Ⅱ consisted of YcP2, YcP3 and CqP7. The strains of group Ⅲ were distributed abroad. Group Ⅳ consisted of WzP3, WzP15 and R. etli CFN42. RAPD divided the isolates into nine clusters in which group Ⅳ only consisted of YcP2 and the strains of group Ⅴ and Ⅸ were from Wenzhou and Xiantao, respectively. This assay demonstrated the geographical effect on genetic diversity of pea rhizobia.

  5. Phylogeny and diversity of broad bean rhizobium in Qinghai%青海蚕豆根瘤菌的系统发育与多样性研究

    Institute of Scientific and Technical Information of China (English)

    韩梅; 马晓彤; 曹卫东; 张宏亮; 王雪翠

    2015-01-01

    To explore and exploit broad bean rhizobium of Qinghai, and determine their classification status.Broad bean rhizobia were collected in Qinghai and 16 SrDNA identification, phylogeny and diversity were studied.The results showed that 6 strains belonging to 4 groups respectively, andR. leguminosarum, R.laguerreae, R.fabae, R.pisi have the closest phylogenetic relationship.The species diversity is rich in Qinghai.%为发掘和利用青海冷凉地区蚕豆优良的根瘤菌种质资源,确定其分类地位.通过对青海冷凉地区采集的蚕豆根瘤菌进行16 SrDNA鉴定、系统发育及多样性研究.结果表明:6株供试菌株属于4个类聚,分别与Rhizobium leguminosarum,R.laguerreae,R.fabae,R.pisi亲缘关系最为接近,种类多样性较为丰富.

  6. The celC gene, a new phylogenetic marker useful for taxonomic studies in Rhizobium.

    Science.gov (United States)

    Robledo, Marta; Velázquez, Encarna; Ramírez-Bahena, Martha Helena; García-Fraile, Paula; Pérez-Alonso, Ana; Rivas, Raúl; Martínez-Molina, Eustoquio; Mateos, Pedro F

    2011-09-01

    The celC gene codifies for a cellulase that fulfils a very significant role in the infection process of clover by Rhizobium leguminosarum. This gene is located in the celABC operon present in the chromosome of strains representing R. leguminosarum, Rhizobium etli and Rhizobium radiobacter whose genomes have been completely sequenced. Nevertheless, the existence of this gene in other species of the genus Rhizobium had not been investigated to date. In this study, the celC gene was analysed for the first time in several species of this genus isolated from legume nodules and plant tumours, in order to compare the celC phylogeny to those of other chromosomal and plasmidic genes. The results obtained showed that phylogenies of celC and chromosomal genes, such as rrs, recA and atpD, were completely congruent, whereas no relation was found with symbiotic or virulence genes. Therefore, the suitability and usefulness of the celC gene to differentiate species of the genus Rhizobium, especially those with closely related rrs genes, was highlighted. Consequently, the taxonomic status of several strains of the genus Rhizobium with completely sequenced genomes is also discussed.

  7. Effects of nano-ZnO on the agronomically relevant Rhizobium-legume symbiosis.

    Science.gov (United States)

    Huang, Yu Chu; Fan, Ruimei; Grusak, Michael A; Sherrier, Janine D; Huang, C P

    2014-11-01

    The impact of nano-ZnO (nZnO) on Rhizobium-legume symbiosis was studied with garden pea and its compatible bacterial partner Rhizobium leguminosarum bv. viciae 3841. Exposure of peas to nZnO had no impact on germination, but significantly affected root length. Chronic exposure of plant to nZnO impacted its development by decreasing the number of the first- and the second-order lateral roots, stem length, leaf surface area, and transpiration. The effect of nZnO dissolution on phytotoxicity was also examined. Results showed that Zn(2+) had negative impact on plant development. Exposure of R. leguminosarum bv. viciae 3841 to nZnO brought about morphological changes by rendering the microbial cells toward round shape and damaging the bacterial surface. Furthermore, the presence of nZnO in the rhizosphere affected root nodulation, delayed the onset of nitrogen fixation, and caused early senescence of nodules. Attachment of nanoparticles on the root surface and dissolution of Zn(2+) are important factors affecting the phytotocity of nZnO. Hence, the presence of nZnO in the environment is potentially hazardous to the Rhizobium-legume symbiosis system.

  8. INFLUENCE OF N2-FIXING BACTERIA ON PEA PLANTS AND HUMUS FRACTIONS IN SOIL EXPERIMENTALLY POLLUTED WITH CADMIUM

    Directory of Open Access Journals (Sweden)

    S. Matei

    2012-12-01

    Full Text Available Heavy metals accumulation has negative effects on plant growth and yields, especially in leguminous sensible species, as well as on soil processes, such as nutrients cycling, humification or degradation of various pollutants. Under the impact of heavy metals, inoculation with effective N2-fixing bacterial strains could positively influence plant development and soil processes. A greenhouse experiment has been carried out in order to assess changes in growth and nodulation of pea plants, cultivar CORINA inoculated with Rhizobium leguminosarum bv. leguminosarum strain Mz 805,under the influence of growing concentrations of cadmium in soil (1ppm, 3ppm and 30ppm, as compared with non-inoculated plants and non-polluted control. The paper presents the results concerning the effect of cadmium on plant growth, nodulation parameters and yields at main developing stages. These parameters significantly decreased when cadmium increased. The values of regression coefficients calculated were higher in non-inoculated variants than in inoculated ones. Chromatography revealed that in rhizosphere of pea plants inoculated with strain Mz 804, composition of humus fractions THAC, TFAC and FAC I was modified by the different nature of root exudates.

  9. Avirulent mutants of Macrophomina phaseolina and Aspergillus fumigatus initiate infection in Phaseolus mungo in the presence of phaseolinone; levamisole gives protection.

    Science.gov (United States)

    Sett, S; Mishra, S K; Siddiqui, K A

    2000-03-01

    To evaluate the role of phaseolinone, a phytotoxin produced by Macrophomina phaseolina, in disease initiation, three nontoxigenic avirulent mutants of the fungus were generated by UV-mutagenesis. Two of them were able to initiate infection in germinating Phaseolus mungo seeds only in the presence of phaseolinone. The minimum dose of phaseoli-none required for infection in 30% seedlings was 2 5 mg/ml. A human pathogen, Aspergillus fumigatus was also able to infect germinating seeds of P. mungo in the presence of 5 mg/ml concentration of phaseolinone. Phaseolinone seemed to facilitate infection by A. fumigatus, which is not normally phytopathogenic, by reducing the immunity of germinating seedlings in a nonspecific way. Levamisole, a non-specific immunopotentiator gave protection against infection induced by A. fumigatus at an optimum dose of 50 mg/ml. Sodium malonate prevented the effects of levamisole.

  10. INFLUÊNCIA DO PREPARO DE SOLO E DA ROTAÇÃO DE CULTURAS NA SEVERIDADE DE PODRIDÕES RADICULARES NO FEIJOEIRO COMUM EFFECTS OF SOIL TILLAGE SYSTEM AND CROP ROTATION ON DRY BEAN ROOT ROT SEVERITY

    Directory of Open Access Journals (Sweden)

    Pedro Marques da Silveira

    2007-09-01

    Full Text Available

    As podridões radiculares do feijoeiro são causadas pelos fungos Rhizoctonia solani Kühn e Fusarium solani f. sp. phaseoli Snyd. & Hans. Neste trabalho testou-se a combinação dos fatores preparo de solo e rotação de culturas, além de se avaliarem seus efeitos sobre as podridões radiculares do feijoeiro. Os tipos de preparo de solo consistiram em: arado+grade (P1, arado (P2, grade (P3 e plantio direto (P4. As rotações de culturas foram: arroz-feijão (R1, milho-feijão (R2, arroz/calopogônio (Calopogonium muconoides-feijão (R3 e milho-feijão-milho-feijão-arroz-feijão (R4. A severidade de F. solani f. sp. phaseoli, avaliada aos 25 dias após o plantio, apresentou interação significativa, sendo a maior severidade encontrada na combinação da rotação R3 com o preparo de solo P1, e a menor severidade, na combinação da rotação R2 com o preparo de solo P3. Diferenças estatísticas ocorreram na severidade da doença provocada por R. solani. O preparo de solo P3 apresentou maior severidade que P4, e, entre as rotações, R3 apresentou a maior severidade da doença.

    PALAVRAS-CHAVE: Rhizoctonia solani; Fusarium solani f. sp. phaseoli; práticas culturais; fungos.

    Dry bean root rot is caused by the fungi Rhizoctonia solani Kühn and Fusarium solani f. sp. phaseoli Snyd. & Hans.The effects of the interaction between soil tillage systems andcrop rotation on the severity of root rot was tested. The soiltillage systems consisted of plough+harrow (P1, plough (P2,harrow (P3 and no tillage (P4 and the crop rotation treatmentswere rice-bean (R1, corn-bean (R2, rice/Calopogonium muconoides-bean (R3 and corn

  11. Determinants of nodulation competitiveness in Rhizobium etli. Final report for period September 30, 1996--September 29, 1999

    Energy Technology Data Exchange (ETDEWEB)

    Handelsman, Jo

    2000-01-04

    Nitrogen is a major limiting nutrient in crop production. Chemical fertilizers, which are used extensively to meet crop nitrogen requirements, contribute to the high energy inputs of modern agriculture and cause human health and environmental problems. Legumes and their bacterial associates have long been used in crop rotations to replenish soil nitrogen, but effective and reliable biological nitrogen fixation for beans is prevented by the lack of nodulation competitiveness of many Rhizobium strains used as inoculants. The result is that the inoculant strains will not occupy the host's nodules and no benefit will be derived from inoculation. Many indigenous soil strains of Rhizobium etli bv. phaseoli, the symbiont of bean, nodulate but fix little or no nitrogen, and therefore the nodulation competitiveness problem is significant for achieving maximum nitrogen benefit from bean crops. This project was directed toward developing an understanding of the basis of nodulation competitiveness.

  12. Custo adaptativo da indução de resistência em feijoeiro mediada pela rizobactéria Bacillus cereus ou acibenzolar-S-metil: atividade de enzimas, síntese de fenóis e lignina e biomassa Fitness cost of induced resistance in bean plants by the rhizobacteria Bacillus cereus or acibenzolar-S-methyl: enzymes activities, phenol and lignin synthesis, and biomass

    Directory of Open Access Journals (Sweden)

    Odair José Kuhn

    2010-06-01

    Full Text Available Plantas que utilizam recursos para defesa na ausência de pragas ou patógenos, arcarão com custos energéticos que podem refletir na sua produtividade. Assim, teve-se por objetivo avaliar os custos adaptativos da indução de resistência, antes da chegada do patógeno, em feijoeiro induzido por um indutor biótico (Bacillus cereus e um abiótico (acibenzolar-S-metil, ASM, em 2, 3 ou 4 aplicações distribuídas ao longo do ciclo da cultura. Avaliou-se o efeito protetor contra a bactéria Xanthomonas axonopodis pv. phaseoli, além da atividade de peroxidase, quitinase, β-1,3-glucanase, síntese de lignina, fenóis e crescimento com base na matéria seca. Observou-se que os indutores protegeram a cultura contra X. axonopodis pv. phaseoli com base na redução da severidade. O ASM aumentou a atividade de peroxidase, quitinase e β-1,3-glucanase, enquanto que o B. cereus aumentou apenas a peroxidase. O ASM aumentou a síntese de lignina e B. cereus não, enquanto que ASM diminuiu teor de fenóis e B. cereus não. O ASM reduziu a biomassa da planta, o que não ocorreu em plantas induzidas por B. cereus. Portanto, a resistência induzida por ASM apresenta elevado custo associado, enquanto que por B. cereus apresenta baixo custo, necessitando a indução de resistência ser melhor explorada e estudada para potencializar seu uso em feijoeiro.Plants that use resources to defend themselves in the absence of pests or pathogens will pay off with energy costs that can reflect in the productivity. Thus, the objective of this work was to evaluate the fitness costs of the resistance induced in bean plants, before the presence of the pathogen, by using biotic (Bacillus cereus and abiotic (acibenzolar-S-methyl, ASM inducers, applied 2, 3 or 4 times during the cycle of the culture. The protecting effect was evaluated against the bacterium Xanthomonas axonopodis pv. phaseoli. The activities of peroxidase, chitinase and β-1,3-glucanase, lignin and phenol

  13. Application of some insecticides and plant crude extracts for controlling insect pests in yard long bean

    Directory of Open Access Journals (Sweden)

    Wipawadee Chamnan

    2003-05-01

    Full Text Available Tests on plant crude extracts of neem seeds, galanga and citronella grass at the rates of 200 ml/20 L of water together with synthetic insecticides, cypermethrin, methamidophos, carbosulfan and carbofuran, at the recommended rates showed that none of the treatments was effective in controlling plant damage caused by adult of bean fly (Ophiomyia phaseoli Tryon. The application of the synthetic insecticide, methamidophos, and plant crude extracts of neem seeds + galanga + citronella grass provided the highest effectiveness tocontrol aphids (Aphis craccivora Koch. Control of A. craccivora was not significantly different between the synthetic insecticide and plant crude extracts, except methamidophos. Pod damage caused by pod borer (Maruca testulalis Geyer and yields were also not significantly different among treatments. However, the highest yield of 1,224.7 kg/rai was recorded in plots treated with neem seed extracts and the synthetic insecticide, carbosulfan. In untreated plots, the lowest yield of 587.3 kg/rai was collected.

  14. Linhagens de feijoeiro comum com fenótipos agronômicos favoráveis e resistência ao crestamento bacteriano comum e antracnose Common bean lines with suitable agronomic phenotypes and resistant to bacterial blight and anthracnose

    Directory of Open Access Journals (Sweden)

    Joaquim Geraldo Cáprio da Costa

    2003-10-01

    Full Text Available O crestamento bacteriano comum e a antracnoseincitados por Xanthomonas axonopodis pv. phaseoli (Smith Vauterin, Hoste, Kesters & Swings e Colletotrichum lindemuthianum (Sacc. & Magn. Scrib., respectivamente, podem reduzir consideravelmente a produtividade do feijoeiro comum (Phaseolus vulgaris L.. Conduziu-se este trabalho com o objetivo de obter linhagens com resistência conjunta ao crestamento bacteriano comum e à antracnose, com características agronômicas desejáveis. Foram obtidas 35 populações F2 provenientes de cruzamentos simples entre linhagens com resistência ao crestamento bacteriano comum proveniente de P. acutifolius A. Gray e linhagens resistentes à antracnose e com características agronômicas favoráveis. As populações segregantes de F2 a F5 foram inoculadas com o patótipo 89 de C. lindemuthianum com uma concentração de 1,2 x 10(6 conídios/mL e submetidas à seleção massal modificada. As plantas que apresentaram grau superior a 4 foram eliminadas. Na geração F5, foi realizada seleção individual das plantas remanescentes para obter as famílias F6. As famílias F6 foram avaliadas mediante inoculação com os patótipos 55, 89, 95 e 453 de C. lindemuthianum. As famílias F7 resistentes à antracnose foram inoculadas em casa-de-vegetação por incisão das folhas primárias com tesoura mergulhada em uma suspensão de 5 x 10(7 ufc do isolado XpCNF 15 de X. axonopodis pv. phaseoli. As linhagens resistentes foram avaliadas em quatro experimentos de campo. Foram selecionadas 17 linhagens com alto rendimento de grãos, resistentes ao crestamento bacteriano comum e à antracnose, com boa altura de inserção das vagens inferiores e resistentes ao acamamento.Common bacterial blight and anthracnose diseases, incited by Xanthomonas axonopodis pv. phaseoli (Smith Vauterin, Hoste, Kesters & Swings and Colletotrichum lindemuthianum (Sacc. & Magn. Scrib., respectively, are major constrains for dry bean (Phaseolus vulgaris L

  15. Rendimiento y reacción a enfermedades en frijol tipo Flor de Mayo en riego y temporal Seed yield and disease reaction in Flor de Mayo bean type grown under irrigation and rainfed conditions

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    Jorge Alberto Acosta Gallegos

    Full Text Available El frijol tipo Flor de Mayo es de alta demanda entre los consumidores del centro de México, su producción se realiza en las regiones de la Mesa Central, El Bajío y Semiárida. El objetivo fue determinar el rendimiento, peso de la semilla y reacción a enfermedades de un grupo de 14 líneas y dos testigos a través de 14 ambientes, 10 de temporal y cuatro de riego. Los ensayos se condujeron durante los ciclos primavera-verano 2008 y otoño-invierno 2008-2009. Se realizaron análisis de conjunto y por ensayos de temporal y de riego en forma independiente. Diferentes enfermedades atacaron al cultivo a través de los sitios de prueba; bajo temporal, las de mayor distribución fueron la bacteriosis común (Xanthomonas campestris pv phaseoli y la mancha angular (Phaeoisariopsis griseola; mientras que la antracnosis (Colletotrichum lindemuthianum y el mildiú velloso (Phythohpthora phaseoli mostraron un fuerte ataque en Calera, Zacatecas y Celaya, Guanajuato, respectivamente. El ambiente de mayor rendimiento promedio fue Celaya bajo riego (4.15 t ha-1 y el menor se obtuvo en Texcoco bajo temporal (0.90 t ha-1. El análisis conjunto detecto diferencias significativas (pThe 'Flor de Mayo' bean type is highly demanded by consumers in Central Mexico, its production takes place at the semiarid, El Bajio and the central plateau regions. The aim was to test a set of 14 bred lines plus two checks across 10 rainfed locations and four irrigated sites on the basis of seed yield, 100-seeds weight and disease reaction. Trials were conducted in the spring-summer season 2008 and fall-winter season 2008-2009. Data analyses were conducted including all test sites, and independently rainfed and irrigated sites. Different diseases attacked the crop across test sites; those widely distributed were common bacterial blight (Xanthomonas campestris pv phaseoli and angular leaf spot (Phaeoisariopsis griseola; whereas anthracnose (Colletotrichum lindemuthianum and downy

  16. ANTIFUNGAL AND CYTOTOXIC ACTIVITIES OF FIVE TRADITIONALLY USED INDIAN MEDICINAL PLANTS

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    Adhikarimayum Haripyaree

    2013-02-01

    Full Text Available Hexane, Methanol and Distilled water extracts of five Indian Medicinal plants viz., Mimosa pudica L, Vitex trifolia Linn, Leucas aspera Spreng, Centella asiatica (L Urban and Plantago major Linn belonging to different families were subjected to preliminary antimicrobial screening against six standard organisms viz., Ceratocystis paradoxa, Aspergillus niger, Penicillium citrinum, Macrophomina phaseoli, Trichoderma viride and Rhizopus nigricans. To evaluate antifungal activity agar well diffusion method was used. In addition LD50 of the same plant extracts were determined by using Range test on Mus musculus for cytotoxic activity. Methanolic extract of M. pudica showed the highest and significant inhibitory effect against some fungal species. Again, methanolic extract of M. pudica displayed the greatest cytotoxic activity.

  17. Characterization of the gene encoding pisatin demethylase (FoPDA1) in Fusarium oxysporum.

    Science.gov (United States)

    Coleman, Jeffrey J; Wasmann, Catherine C; Usami, Toshiyuki; White, Gerard J; Temporini, Esteban D; McCluskey, Kevin; VanEtten, Hans D

    2011-12-01

    The pea pathogen Fusarium oxysporum f. sp. pisi is able to detoxify pisatin produced as a defense response by pea, and the gene encoding this detoxification mechanism, FoPDA1, was 82% identical to the cytochrome P450 pisatin demethylase PDA1 gene in Nectria haematococca. A survey of F. oxysporum f. sp. pisi isolates demonstrated that, as in N. haematococca, the PDA gene of F. oxysporum f. sp. pisi is generally located on a small chromosome. In N. haematococca, PDA1 is in a cluster of pea pathogenicity (PEP) genes. Homologs of these PEP genes also were found in the F. oxysporum f. sp. pisi isolates, and PEP1 and PEP5 were sometimes located on the same small chromosomes as the FoPDA1 homologs. Transforming FoPDA1 into a pda(?) F. oxysporum f. sp. lini isolate conferred pda activity and promoted pathogenicity on pea to some transformants. Different hybridization patterns of FoPDA1 were found in F. oxysporum f. sp. pisi but these did not correlate with the races of the fungus, suggesting that races within this forma specialis arose independently of FoPDA1. FoPDA1 also was present in the formae speciales lini, glycines, and dianthi of F. oxysporum but they had mutations resulting in nonfunctional proteins. However, an active FoPDA1 was present in F. oxysporum f. sp. phaseoli and it was virulent on pea. Despite their evolutionary distance, the amino acid sequences of FoPDA1 of F. oxysporum f. sp. pisi and F. oxysporum f. sp. phaseoli revealed only six amino acid differences, consistent with a horizontal gene transfer event accounting for the origin of these genes.

  18. EFEITO ANTIBIÓTICO DO PRÓPOLIS SOBRE BACTÉRIAS FITOPATOGÊNICAS

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    L. BIANCHINI

    1998-01-01

    Full Text Available O efeito antibiótico de extrato aquoso de própolis, em várias concentrações, foi avaliado para cinco espécies de bactérias fitopatogênicas. Agrobacterium tumefaciens, Clavibacter michiganensis subsp. michiganensis e Xanthomonas axonopodis pv. phaseoli foram completamente inibidas em meio de cultura contendo 10% de extrato de própolis. Erwinia chrysanthemi foi parcialmente inibida, enquanto Pseudomonas syringae pv. tabaci se mostrou insensível ao extrato, desenvolvendo colônias idênticas àquelas observadas em meios livres de própolis. Concentrações menores não foram suficientes para exercer um efeito antimicrobiano desejável sobre as bactérias pertencentes a todas as espécies testadas. Resultados idênticos foram obtidos quando própolis foi incorporado ao meio antes ou após a autoclavagem, demonstrando que a substância ativa presente no extrato não é termosensível. Foi demonstrado, portanto, o uso potencial do própolis como antibiótico para o controle de bactérias fitopatogênicas.The antibiotic effect of aqueous extract of propolis was evaluated in vitro against five species of bacteria. The growth of Agrobacterium tumefaciens, Clavibacter michiganensis subsp. michiganensis and Xanthomonas axonopodis pv. phaseoli was completely inhibited in a medium containing 10% of propolis. Erwinia chrysanthemi was partially inhibited and Pseudomonas syringae pv. tabaci was not affected. Lower concentration of the aqueous extract was not effective to promote a desirable antibiotic action against all bacterial species tested. The active ingredient present in the propolis was thermostable. The potential use of the propolis to control phytopathogenic bacteria was demonstrated.

  19. Diversity of sporadic symbionts and nonsymbiotic endophytic bacteria isolated from nodules of woody, shrub, and food legumes in Ethiopia.

    Science.gov (United States)

    Aserse, Aregu Amsalu; Räsänen, Leena A; Aseffa, Fassil; Hailemariam, Asfaw; Lindström, Kristina

    2013-12-01

    Fifty-five bacterial isolates were obtained from surface-sterilized nodules of woody and shrub legumes growing in Ethiopia: Crotalaria spp., Indigofera spp., and Erythrina brucei, and the food legumes soybean and common bean. Based on partial 16S rRNA gene sequence analysis, the majority of the isolates were identified as Gram-negative bacteria belonging to the genera Achromobacter, Agrobacterium, Burkholderia, Cronobacter, Enterobacter, Mesorhizobium, Novosphingobium, Pantoea, Pseudomonas, Rahnella, Rhizobium, Serratia, and Variovorax. Seven isolates were Gram-positive bacteria belonging to the genera Bacillus, Paenibacillus, Planomicrobium, and Rhodococcus. Amplified fragment length polymorphism (AFLP) fingerprinting showed that each strain was genetically distinct. According to phylogenetic analysis of recA, glnII, rpoB, and 16S rRNA gene sequences, Rhizobium, Mesorhizobium, and Agrobacterium were further classified into six different genospecies: Agrobacterium spp., Agrobacterium radiobacter, Rhizobium sp., Rhizobium phaseoli, Mesorhizobium sp., and putative new Rhizobium species. The strains from R. phaseoli, Rhizobium sp. IAR30, and Mesorhizobium sp. ERR6 induced nodules on their host plants. The other strains did not form nodules on their original host. Nine endophytic bacterial strains representing seven genera, Agrobacterium, Burkholderia, Paenibacillus, Pantoea, Pseudomonas, Rhizobium, and Serratia, were found to colonize nodules of Crotalaria incana and common bean on co-inoculation with symbiotic rhizobia. Four endophytic Rhizobium and two Agrobacterium strains had identical nifH gene sequences with symbiotic Rhizobium strains, suggesting horizontal gene transfer. Most symbiotic and nonsymbiotic endophytic bacteria showed plant growth-promoting properties in vitro, which indicate their potential role in the promotion of plant growth when colonizing plant roots and the rhizosphere.

  20. Determinação da variabilidade em isolados de Colletotrichum lindemuthianum por meio de marcadores morfológicos e culturais Determination of variability in isolates of Colletotrichum lindemuthianum based on morphological and cultural markers

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    Breno Oliveira de Souza

    2007-08-01

    Full Text Available Colletotrichum lindemuthianum (teleomorfo Glomerella cingulata f. sp. phaseoli apresenta ampla variabilidade genética, demonstrada por suas características morfológicas. Com este trabalho, objetivou-se caracterizar, por meio de marcadores morfológicos, diferentes isolados de C. lindemuthianum e identificar marcadores morfológicos com uso potencial em análises genéticas. Foram avaliados os seguintes caracteres morfológicos e culturais: cor e textura das colônias, compatibilidade vegetativa e sexual, índice de velocidade de crescimento micelial (IVCM, diâmetro colonial (DC, capacidade de esporulação (CE, dimensões e formas conidiais, dimensões dos ascósporos, formação de estruturas reprodutivas e formação de anastomoses entre hifas e conídios. Os resultados obtidos demonstraram que os isolados de C. lindemuthianum possuem ampla variabilidade genética para todas as características avaliadas e que a forma do conídio pode ser usada como marcador morfológico em análises genéticas.Colletotrichum lindemuthianum (teleomorfo Glomerella cingulata f. sp. phaseoli presents wide genetic variability, demonstrated by its morphological traits. The objective of this study was to characterize morphological markers in different isolates of C. lindemuthianum and, to identify useful morphological markers in genetic analyses. The following morphological and cultural traits were evaluated: color and texture of the colonies, vegetative and sexual compatibility, micelial growth index (MGI, colonial diameter (CD, esporulation capacity (EC, conidia dimensions and form, ascospores dimensions and formation of reproductive structures. The data showed wide genetic variability for all traits and that conidial form can be used as morphological marker in genetic analysis.

  1. Microbially produced extracellular poly-saccharidic Pu(IV)- binding ligands

    Energy Technology Data Exchange (ETDEWEB)

    Hung, C.C.; Roberts, K.A.; Schwehr, K.A.; Santschi, P.H. [Texas A and M University at Galveston, 5007 Ave U, Galveston, TX 77551 (United States)

    2005-07-01

    Full text of publication follows: The investigation of the Pu-binding properties of ligands for diverse extracellular polysaccharides (EPS) is of relevance for the quantitative understanding of colloidal barriers to radionuclide migration. The EPS isolated for this study were from four different bacteria species: a) two aerobic soil bacteria: Shewanella putrefaciens CN32 and Pseudomonas fluorescens Biovar II; and b) one anaerobic bacterium, Clostridium sp. BC1. EPS from these bacteria were isolated through repeated ethanol precipitations. The neutral monosaccharides in the EPS from Pseudomonas florescens Biovar II that were determined by GC-MS consisted of rhamnose, fucose, ribose, arabinose, xylose, mannose, galactose and glucose. The potentially Pu(IV) binding EPS ligands were mainly composed of carboxylic acids and other minor poly-anionic groups, e.g., sulphates and phosphates. Up to 70 % of total carbohydrates were hydrophilic uronic acids, and total carbohydrates made up 23-31% of organic carbon for P. florescens Biovar II and 9-17% of organic carbon for S. putrefaciens CN32. Besides the neutral and acidic sugars in the EPS, there were also 2-13 % of more hydrophobic proteins among these bacterial EPS. Pu binding to these exo-polymers showed log Kd values of about 5 - 6, with results strongly dependent on procedural details (e.g., removal of colloids in Pu(IV) tracer and reagent solutions). We hypothesize that the relative hydrophobicity of the EPS ligands affects the outcome in ternary sorption studies with colloidal silica. Experiments with varying relative hydrophobicities of EPS will elucidate the different sorption strengths and/or attachment potentials of the Pu-binding ligands to inorganic surfaces. (authors)

  2. Ureaplasma: Current perspectives

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    P Kokkayil

    2015-01-01

    Full Text Available Ureaplasma species are the most prevalent genital Mycoplasma isolated from the urogenital tract of both men and women. Ureaplasma has 14 known serotypes and is divided into two biovars- Ureaplasma parvum and Ureaplasma urealyticum. The organism has several genes coding for surface proteins, the most important being the gene encoding the Multiple Banded Antigen (MBA. The C-terminal domain of MBA is antigenic and elicits a host antibody response. Other virulence factors include phospholipases A and C, IgA protease and urease. Besides genital tract infections and infertility, Ureaplasma is also associated with adverse pregnancy outcomes and diseases in the newborn (chronic lung disease and retinopathy of prematurity. Infection produces cytokines in the amniotic fluid which initiates preterm labour. They have also been reported from renal stone and suppurative arthritis. Genital infections have also been reported with an increasing frequency in HIV-infected patients. Ureaplasma may be a candidate ′co factor′ in the pathogenesis of AIDS. Culture and polymerase chain reaction (PCR are the mainstay of diagnosis. Commercial assays are available with improved turnaround time. Micro broth dilution is routinely used to test antimicrobial susceptibility of isolates. The organisms are tested against azithromycin, josamycin, ofloxacin and doxycycline. Resistance to macrolides, tetracyclines and fluoroquinolones have been reported. The susceptibility pattern also varies among the biovars with biovar 2 maintaining higher sensitivity rates. Prompt diagnosis and initiation of appropriate antibiotic therapy is essential to prevent long term complications of Ureaplasma infections. After surveying PubMed literature using the terms ′Ureaplasma′, ′Ureaplasma urealyticum′ and ′Ureaplasma parvum′, relevant literature were selected to provide a concise review on the recent developments.

  3. Evaluation and selection of tandem repeat loci for a Brucella MLVA typing assay

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    Denoeud France

    2006-02-01

    Full Text Available Abstract Background The classification of Brucella into species and biovars relies on phenotypic characteristics and sometimes raises difficulties in the interpretation of the results due to an absence of standardization of the typing reagents. In addition, the resolution of this biotyping is moderate and requires the manipulation of the living agent. More efficient DNA-based methods are needed, and this work explores the suitability of multiple locus variable number tandem repeats analysis (MLVA for both typing and species identification. Results Eighty tandem repeat loci predicted to be polymorphic by genome sequence analysis of three available Brucella genome sequences were tested for polymorphism by genotyping 21 Brucella strains (18 reference strains representing the six 'classical' species and all biovars as well as 3 marine mammal strains currently recognized as members of two new species. The MLVA data efficiently cluster the strains as expected according to their species and biovar. For practical use, a subset of 15 loci preserving this clustering was selected and applied to the typing of 236 isolates. Using this MLVA-15 assay, the clusters generated correspond to the classical biotyping scheme of Brucella spp. The 15 markers have been divided into two groups, one comprising 8 user-friendly minisatellite markers with a good species identification capability (panel 1 and another complementary group of 7 microsatellite markers with higher discriminatory power (panel 2. Conclusion The MLVA-15 assay can be applied to large collections of Brucella strains with automated or manual procedures, and can be proposed as a complement, or even a substitute, of classical biotyping methods. This is facilitated by the fact that MLVA is based on non-infectious material (DNA whereas the biotyping procedure itself requires the manipulation of the living agent. The data produced can be queried on a dedicated MLVA web service site.

  4. Performance of skin tests with allergens from B. melitensis B115 and rough B. abortus mutants for diagnosing swine brucellosis.

    Science.gov (United States)

    Dieste-Pérez, L; Blasco, J M; De Miguel, M J; Marín, C M; Barberán, M; Conde-Álvarez, R; Moriyón, I; Muñoz, P M

    2014-01-10

    Swine brucellosis by Brucella suis biovar 2 is an emerging disease whose control is based on serological testing and culling. However, current serological tests detect antibodies to the O-polysaccharide (O/PS) moiety of Brucella smooth lipopolysaccharide (S-LPS), and thus lack specificity when infections by Yersinia enterocolitica O:9 and other gram-negative bacteria carrying cross-reacting O/PS occur. The skin test with the protein-rich brucellin extract obtained from rough B. melitensis B115 is assumed to be specific for discriminating these false positive serological reactions (FPSR). However, B115 strain, although unable to synthesize S-LPS, accumulates O/PS internally, which could cause diagnostic problems. Since the brucellin skin test has been seldom used in pigs and FPSR are common in these animals, we assessed its performance using cytosoluble protein extracts obtained from B. abortus rough mutants in manBcore or per genes (critical for O/PS biosynthesis) and B. melitensis B115. The diagnostic sensitivity and specificity were determined in B. suis biovar 2 culture positive and brucellosis free sows, and apparent prevalence in sows of unknown individual bacteriological and serological status belonging to B. suis biovar 2 naturally infected herds. Moreover, the specificity in discriminating brucellosis from FPSR was assessed in brucellosis free boars showing FPSR. The skin test with B. abortus ΔmanBcore and B. melitensis B115 allergens performed similarly, and the former one resulted in 100% specificity when testing animals showing FPSR in indirect ELISA, Rose Bengal and complement fixation serological tests. We conclude that O/PS-free genetically defined mutants represent an appropriate alternative to obtain Brucella protein extracts for diagnosing swine brucellosis.

  5. [ISOLATION OF ANTIBIOTICS RESISTANCE GENES IN VIBRIO CHOLERAE O1 AND O139 SEROGROUP STRAINS].

    Science.gov (United States)

    Zadnova, S P; Smirnova, N I

    2015-01-01

    Determination of sensitivity of V. cholerae O1 serogroup El Tor biovar and O139 serogroup strains to antibiotics and determination of the presence of antibiotics resistance genes in their genome. The studies were carried out in 75 V. cholerae O1 and O139 serogroup strains. Sensitivity of cultures to antibiotics was determined by disc-diffusion method. DNA isolation was carried out in the presence of 6M guanidine thiocyanate. PCR was carried out in multi-channel amplificator Tercyc. A multiplex PCR was constructed, that includes 5 primer pairs for the detection of O1 and O139 serogroup resistance genes of vibrios to sulfame- thoxazolum, streptomycin B, trimethoprim, the presence of SXT element, an amplification program was developed. Using the developed PCR, V. cholerae O1 serogroup El Tor biovar strains with multiple drug resistance were established to be imported into Russia in 1993. The presence of SXT elements with genes of resistance to 4 antibiotics simultaneously was detected precisely in these strains, that belong to toxigenic genovariants of V. cholerae El Tor biovar. All the El Tor vibrio strains imported in the subsequent years were shown to stably preserve SXT element, this indicates its important role in biology of cholera vibrios. O139 serogroup strains with intact SXT element and having a deletion of the gene coding trimethoprim resistance were isolated. The data obtained may be used to establish molecular-genetic mechanisms of emergence of antibiotics resistant strains of cholera vibrio, construction of novel gene diagnostic test-systems and carrying out passportization of strains that are stored in the State collection of pathogenic bacteria.

  6. Spatial distribution and risk factors of Brucellosis in Iberian wild ungulates

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    de la Fuente José

    2010-03-01

    Full Text Available Abstract Background The role of wildlife as a brucellosis reservoir for humans and domestic livestock remains to be properly established. The aim of this work was to determine the aetiology, apparent prevalence, spatial distribution and risk factors for brucellosis transmission in several Iberian wild ungulates. Methods A multi-species indirect immunosorbent assay (iELISA using Brucella S-LPS antigen was developed. In several regions having brucellosis in livestock, individual serum samples were taken between 1999 and 2009 from 2,579 wild bovids, 6,448 wild cervids and4,454 Eurasian wild boar (Sus scrofa, and tested to assess brucellosis apparent prevalence. Strains isolated from wild boar were characterized to identify the presence of markers shared with the strains isolated from domestic pigs. Results Mean apparent prevalence below 0.5% was identified in chamois (Rupicapra pyrenaica, Iberian wild goat (Capra pyrenaica, and red deer (Cervus elaphus. Roe deer (Capreolus capreolus, fallow deer (Dama dama, mouflon (Ovis aries and Barbary sheep (Ammotragus lervia tested were seronegative. Only one red deer and one Iberian wild goat resulted positive in culture, isolating B. abortus biovar 1 and B. melitensis biovar 1, respectively. Apparent prevalence in wild boar ranged from 25% to 46% in the different regions studied, with the highest figures detected in South-Central Spain. The probability of wild boar being positive in the iELISA was also affected by age, age-by-sex interaction, sampling month, and the density of outdoor domestic pigs. A total of 104 bacterial isolates were obtained from wild boar, being all identified as B. suis biovar 2. DNA polymorphisms were similar to those found in domestic pigs. Conclusions In conclusion, brucellosis in wild boar is widespread in the Iberian Peninsula, thus representing an important threat for domestic pigs. By contrast, wild ruminants were not identified as a significant brucellosis reservoir for

  7. Characterisation of the genetic diversity of Brucella by multilocus sequencing

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    MacMillan Alastair P

    2007-04-01

    Full Text Available Abstract Background Brucella species include economically important zoonotic pathogens that can infect a wide range of animals. There are currently six classically recognised species of Brucella although, as yet unnamed, isolates from various marine mammal species have been reported. In order to investigate genetic relationships within the group and identify potential diagnostic markers we have sequenced multiple genetic loci from a large sample of Brucella isolates representing the known diversity of the genus. Results Nine discrete genomic loci corresponding to 4,396 bp of sequence were examined from 160 Brucella isolates. By assigning each distinct allele at a locus an arbitrary numerical designation the population was found to represent 27 distinct sequence types (STs. Diversity at each locus ranged from 1.03–2.45% while overall genetic diversity equated to 1.5%. Most loci examined represent housekeeping gene loci and, in all but one case, the ratio of non-synonymous to synonymous change was substantially Brucella species, B. abortus, B. melitensis, B. ovis and B. neotomae correspond to well-separated clusters. With the exception of biovar 5, B. suis isolates cluster together, although they form a more diverse group than other classical species with a number of distinct STs corresponding to the remaining four biovars. B. canis isolates are located on the same branch very closely related to, but distinguishable from, B. suis biovar 3 and 4 isolates. Marine mammal isolates represent a distinct, though rather weakly supported, cluster within which individual STs display one of three clear host preferences. Conclusion The sequence database provides a powerful dataset for addressing ongoing controversies in Brucella taxonomy and a tool for unambiguously placing atypical, phenotypically discordant or newly emerging Brucella isolates. Furthermore, by using the phylogenetic backbone described here, robust and rationally selected markers for use in

  8. Reliable identification at the species level of Brucella isolates with MALDI-TOF-MS

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    Lista Florigio

    2011-12-01

    Full Text Available Abstract Background The genus Brucella contains highly infectious species that are classified as biological threat agents. The timely detection and identification of the microorganism involved is essential for an effective response not only to biological warfare attacks but also to natural outbreaks. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS is a rapid method for the analysis of biological samples. The advantages of this method, compared to conventional techniques, are rapidity, cost-effectiveness, accuracy and suitability for the high-throughput identification of bacteria. Discrepancies between taxonomy and genetic relatedness on the species and biovar level complicate the development of detection and identification assays. Results In this study, the accurate identification of Brucella species using MALDI-TOF-MS was achieved by constructing a Brucella reference library based on multilocus variable-number tandem repeat analysis (MLVA data. By comparing MS-spectra from Brucella species against a custom-made MALDI-TOF-MS reference library, MALDI-TOF-MS could be used as a rapid identification method for Brucella species. In this way, 99.3% of the 152 isolates tested were identified at the species level, and B. suis biovar 1 and 2 were identified at the level of their biovar. This result demonstrates that for Brucella, even minimal genomic differences between these serovars translate to specific proteomic differences. Conclusions MALDI-TOF-MS can be developed into a fast and reliable identification method for genetically highly related species when potential taxonomic and genetic inconsistencies are taken into consideration during the generation of the reference library.

  9. [Standard algorithm of molecular typing of Yersinia pestis strains].

    Science.gov (United States)

    Eroshenko, G A; Odinokov, G N; Kukleva, L M; Pavlova, A I; Krasnov, Ia M; Shavina, N Iu; Guseva, N P; Vinogradova, N A; Kutyrev, V V

    2012-01-01

    Development of the standard algorithm of molecular typing of Yersinia pestis that ensures establishing of subspecies, biovar and focus membership of the studied isolate. Determination of the characteristic strain genotypes of plague infectious agent of main and nonmain subspecies from various natural foci of plague of the Russian Federation and the near abroad. Genotyping of 192 natural Y. pestis strains of main and nonmain subspecies was performed by using PCR methods, multilocus sequencing and multilocus analysis of variable tandem repeat number. A standard algorithm of molecular typing of plague infectious agent including several stages of Yersinia pestis differentiation by membership: in main and nonmain subspecies, various biovars of the main subspecies, specific subspecies; natural foci and geographic territories was developed. The algorithm is based on 3 typing methods--PCR, multilocus sequence typing and multilocus analysis of variable tandem repeat number using standard DNA targets--life support genes (terC, ilvN, inv, glpD, napA, rhaS and araC) and 7 loci of variable tandem repeats (ms01, ms04, ms06, ms07, ms46, ms62, ms70). The effectiveness of the developed algorithm is shown on the large number of natural Y. pestis strains. Characteristic sequence types of Y. pestis strains of various subspecies and biovars as well as MLVA7 genotypes of strains from natural foci of plague of the Russian Federation and the near abroad were established. The application of the developed algorithm will increase the effectiveness of epidemiologic monitoring of plague infectious agent, and analysis of epidemics and outbreaks of plague with establishing the source of origin of the strain and routes of introduction of the infection.

  10. Ocorrência de murcha bacteriana em helicônias e musácea ornamental no Distrito Federal

    OpenAIRE

    Zoccoli, Débora Maria; Tomita, Celso Katsuhiro; Uesugi,Carlos Hidemi

    2009-01-01

    Plantas de Heliconia spp. e Musa spp. apresentando murcha foram observadas em plantio comercial no Distrito Federal. Testes laboratoriais e de inoculação confirmaram como sendo a bactéria Ralstonia solanacearum biovar 1 raça 2 responsável pela doença. Este é o primeiro relato da presença da bactéria em helicônia e musácea ornamental na região. _______________________________________________________________________________ ABSTRACT Plants of Heliconia spp. and Musa spp. presenting wilt were...

  11. Stenotrophomonas maltophilia: a new potential biocontrol agent of Ralstonia solanacearum, causal agent of potato brown rot

    OpenAIRE

    Messiha, N.A.S.; Diepeningen, van, A.D.; Farag, N.S.; Abdallah, S.A.; Janse, J.D.; Bruggen, van, A.S.

    2007-01-01

    Stenotrophomonas maltophilia was isolated from the rhizosphere of eggplant in the Nile Delta of Egypt, and its antagonistic potential against Ralstonia solanacearum race 3 biovar 2, the causal agent of potato brown rot, was in vitro evaluated on KB agar medium and in vivo on potato plants. In vitro, four isolates of S. maltophilia (PD3531, PD3532, PD3533, and PD3534) appeared antagonistic. The isolate (PD3533) was screened as the most promising antagonist for the in vivo tests. In the greenho...

  12. NCBI nr-aa BLAST: CBRC-DDIS-02-0198 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-DDIS-02-0198 ref|NP_233090.1| hypothetical protein VCA0703 [Vibrio cholerae O1... biovar eltor str. N16961] ref|ZP_01480135.1| hypothetical protein VchoM_02000665 [Vibrio cholerae MO10] ref...|ZP_01675362.1| conserved hypothetical protein [Vibrio cholerae 2740-80] ref|ZP_01679126.1| conserved hypoth...etical protein [Vibrio cholerae V52] ref|ZP_01951459.1| conserved hypothetical protein [Vibrio cholera...e MAK 757] ref|ZP_01971260.1| conserved hypothetical protein [Vibrio cholerae NCTC 8457

  13. NCBI nr-aa BLAST: CBRC-TNIG-10-0000 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-TNIG-10-0000 ref|NP_232950.1| GGDEF family protein [Vibrio cholerae O1 biovar ...eltor str. N16961] ref|ZP_01480008.1| hypothetical protein VchoM_02000754 [Vibrio cholerae MO10] ref|ZP_0168...1911.1| GGDEF family protein [Vibrio cholerae V52] ref|YP_001215333.1| GGDEF family protein [Vibrio cholerae... O395] ref|ZP_01953769.1| GGDEF family protein [Vibrio cholerae MAK 757] ref|ZP_0...1971917.1| GGDEF family protein [Vibrio cholerae NCTC 8457] ref|ZP_01975511.1| GGDEF family protein [Vibrio cholera

  14. NCBI nr-aa BLAST: CBRC-DRER-26-0538 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-DRER-26-0538 ref|NP_229856.1| hemolysin secretion ATP-binding protein, putative [Vibrio cholera...e O1 biovar eltor str. N16961] ref|ZP_01681061.1| hemolysin secretion ATP-binding protein, putative [Vibrio cholera...e V52] ref|ZP_01971238.1| hemolysin secretion ATP-binding protein, putative [Vibrio cholera...e NCTC 8457] ref|ZP_01974256.1| hemolysin secretion ATP-binding protein, putative [Vibrio cholera...e B33] gb|AAF93375.1| hemolysin secretion ATP-binding protein, putative [Vibrio cholera

  15. Characteristics and phylogeny of Bacillus cereus strains isolated from Maari, a traditional West African food condiment

    DEFF Research Database (Denmark)

    Thorsen, Line; Kando, Christine Kere; Sawadogo, Hagrétou

    2015-01-01

    light on the succession and pathogenic potential of B. cereus species in traditional West African food condiment and clarifies their phylogenetic relatedness to B. cereus biovar anthracis. Future implementation of GMP and HACCP and development of starter cultures for controlled Maari fermentations......Maari is a spontaneously fermented food condiment made from baobab tree seeds in West African countries. This type of product is considered to be safe, being consumed by millions of people on a daily basis. However, due to the spontaneous nature of the fermentation the human pathogen Bacillus...

  16. Direct Spectrophotometric Assay for Benzaldehyde Lyase Activity

    Directory of Open Access Journals (Sweden)

    Dessy Natalia

    2011-01-01

    Full Text Available Benzaldehyde lyase from Pseudomonas fluorescens Biovar I. (BAL, EC 4.1.2.38 is a versatile catalyst for the organic synthesis of chiral α-hydroxy ketones. To allow fast assessment of enzyme activity, a direct spectrophotometric assay is desirable. Here, a new robust and easy-to-handle assay based on UV absorption is presented. The assay developed is based on the ligation of the α-hydroxy ketone (R-2,2′-furoin from 2-furaldehyde. A robust assay with direct monitoring of the product is facilitated with a convenient concentration working range minimising experimental associated with low concentrations.

  17. A case of pharyngeal diphtheria in Germany, June 2015.

    Science.gov (United States)

    Berger, A; Meinel, D M; Schaffer, A; Ziegler, R; Pitteroff, J; Konrad, R; Sing, Andreas

    2016-10-01

    In June 2015, a 45-year-old man suffering from acute necrotic tonsillitis and throat phlegmon was hospitalized in Nuremberg, Germany. After emergency surgery the patient was initially treated with antibiotics. A throat swab grew a toxigenic Corynebacterium diphtheriae biovar mitis strain. The patient's vaccination status was not documented and the patient was tested serologically for anti-diphtheria antibodies showing no protective immunity. Extensive control investigations were performed by the local health department showing no likely source of his infection. No secondary cases were found and the patient completely recovered.

  18. NCBI nr-aa BLAST: CBRC-DNOV-01-0564 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-DNOV-01-0564 ref|NP_407377.1| hypothetical protein YPO3936 [Yersinia pestis CO...92] ref|NP_671186.1| hypothetical protein y3892 [Yersinia pestis KIM] ref|NP_994586.1| hypothetical protein YP_3298 [Yersinia... pestis biovar Microtus str. 91001] ref|YP_653672.1| hypothetical protein YPA_3765 [Yersinia... pestis Antiqua] ref|YP_649511.1| hypothetical protein YPN_3584 [Yersinia pestis... Nepal516] ref|ZP_01917834.1| putative membrane protein [Yersinia pestis CA88-4125] gb|AAM87437.1|AE013994_2 hypothetical [Yersinia

  19. Genotipos de aislados de campo de Brucella abortus de distintas regiones geográficas de Chile Genotypes of Brucella abortus field isolates from different geographical regions of Chile

    Directory of Open Access Journals (Sweden)

    M Mancilla

    2008-01-01

    Full Text Available La brucelosis bovina es una enfermedad zoonótica, endémica de alto impacto económico. La identificación genética de las cepas prevalentes de Brucella abortus, el patógeno, es clave para establecer estrategias epidemiológicas de control de la enfermedad. La secuencia de inserción IS711 ha sido utilizada como un marcador genético para diferenciar entre especies de Brucella, miembros de una misma especie y dentro de un mismo biovar. Hemos analizado los perfiles de IS711-RFLP de 46 aislados de B. abortus, recolectados durante el periodo 1997-2005, provenientes de 16 áreas geográficas diferentes de Chile. Todos los aislados fueron previamente identificados como B. abortus biovar 1, utilizando las técnicas convencionales. De estos, el 87% compartieron el mismo perfil de IS711-RFLP, mientras que el 8,7% correspondió al patrón de la cepa vacuna RB51. En este trabajo se informa el hallazgo de dos cepas indistinguibles por PCR AMOS con perfiles nuevos de IS711-RFLP, no reportados previamente.Bovine brucellosis is an endemic, zoonotic disease of high economic impact. The genetic identification of the prevalent Brucella abortus strains, the pathogen, is key to pursue further epidemiological strategies for disease control. The insertion sequence IS711 has been used as genetic marker to differentiate among Brucella species, members of the same specie and within the same biovar. We have analyzed the IS711-RFLP pattern for 46 B. abortus isolates, collected during the period of 1997-2005 from 16 different geographical areas of Chile. All isolates were previously identified by conventional techniques as B. abortus biovar 1. Of these, 87% sharedthesame IS711 DNA profile, while an 8.7 % corresponded to the pattern of RB51 vaccine strain. We report the finding of two new strains, not differentiated by AMOS PCR, which showed unreported patterns of IS711-RFLP.

  20. Avaliação da resistência de clones e cultivares de batata à murcha bacteriana (Ralstonia solanacearum)

    OpenAIRE

    Lima Neto, Artur Ferreira

    2005-01-01

    Cultivares e clones de batata (Solanum tuberosum L.) foram avaliados de 2002 a 2004 na Embrapa Hortaliças, Brasília-DF, para resistência à murcha bacteriana em campo naturalmente infestado com a raça 1, biovar 1 de Ralstonia solanacearum. Os testes de avaliação foram conduzidos com as cultivares atualmente mais plantadas no Brasil e com conjuntos de clones relatados como resistentes no Brasil e em outras partes do mundo. Em todos os experimentos, a doença foi avaliada pela incidência de plant...

  1. Analysis of the brucella pathogen and its molecular genotype in Guangdong province%广东省布鲁杆菌的病原学及分子分型分析

    Institute of Scientific and Technical Information of China (English)

    陈经雕; 刘美真; 柯碧霞; 谭海玲; 李柏生; 张万里; 柯昌文

    2012-01-01

    目的 分析广东省布鲁杆菌病原学及分子分型特征.方法 对2010年广东省分离出的19株布鲁杆菌菌株进行传统生物学表型验证,同时进行PCR试验和脉冲凝胶电泳(PFGE)分子分型.结果 4株菌为羊种1型,2株菌为猪种3型,其余均为羊种3型,属特异性B基因阳性,菌株间的PFGE分型相似值介于67.9%~ 100.0%.除了来自珠海的4株菌为爆发,同源性为100.0%,其余菌株均为散发病例.结论 广东省布鲁杆菌病例存在高度散发和分散爆发的流行特征,与前几年比较呈现出种型的多样化,羊种3型仍是目前广东省布鲁杆菌流行株的优势菌型,PFGE方法可在种的水平区分布鲁杆菌的3个种,但不能有效区分同种异型.%Objective To analysis the etiology and molecular classification of brucella strains isolated in Guangdong province in 2010.Methods The strains of 19 brucella were verified and identified by some methods including traditional biology phenotype confirmation,PCR amplification and pulsed field gel electrophoresis (PFGE).Results On phenotype level,4 strains were brucella melitensis biovar 1,2 strains were brucella suis biovar 3,and the rest were brucella melitensis biovar 3,which were specific B genes positive strains,and the PFGE typing similar values ranging from 67.9% to 100%.In addition to the four strains from Zhuhai for the outbreak,the homology was 100%,and the rest were sporadic cases.Conclusions Brucella cases,in Guangdong province,are highly sporadic and dispersed outbreaks.Compared with a few years ago,it shows species diversification,and brucella melitensis biovar 3 is still the dominant serotype.PFGE can be used to distinguish the three species of brucella,but it can't effectively distinguish the allotypes.

  2. Genome-scale reconstruction of the metabolic network in Yersinia pestis CO92

    Science.gov (United States)

    Navid, Ali; Almaas, Eivind

    2007-03-01

    The gram-negative bacterium Yersinia pestis is the causative agent of bubonic plague. Using publicly available genomic, biochemical and physiological data, we have developed a constraint-based flux balance model of metabolism in the CO92 strain (biovar Orientalis) of this organism. The metabolic reactions were appropriately compartmentalized, and the model accounts for the exchange of metabolites, as well as the import of nutrients and export of waste products. We have characterized the metabolic capabilities and phenotypes of this organism, after comparing the model predictions with available experimental observations to evaluate accuracy and completeness. We have also begun preliminary studies into how cellular metabolism affects virulence.

  3. Genome sequence of vibrio cholerae G4222, a South African clinical isolate

    CSIR Research Space (South Africa)

    Le Rouw, Wouter J

    2013-03-01

    Full Text Available sequences of V. cholerae MJ-1236 (7) and V. cholerae O1 biovar El Tor strain N16961 (8) with the NCBI Genomic (NG) Aligner tool of the NCBI Genome Workbench v2.5.5. A further 38 gaps were closed by PCR ampli- fication and Sanger sequencing. This resulted.... 2013. Genome sequence of Vibrio cholerae G4222, a South African clinical isolate. Genome Announc. 1(2):e00040-13. doi:10.1128/genomeA.00040-13. Copyright © 2013 le Roux et al. This is an open-access article distributed under the terms of the Creative...

  4. [Plague in Algeria: about five strains of Yersinia pestis isolated during the outbreak of June 2003].

    Science.gov (United States)

    Lounici, M; Lazri, M; Rahal, K

    2005-02-01

    In this study, we isolated and identified five strains of Yersinia pestis during an epidemic occurred in west of Algeria in June 2003. The bacteriological identification was confirmed by bacteriophage susceptibility. All these strains belonged to the biovar Orientalis (they did not ferment glycerol but did reduce nitrate to nitrite) which caused the current pandemic. The in vitro activities of antimicrobial agents used to treat plague and recommended for prophylaxis, showed that they are active against all strains. The comparison of these strains by plasmid profile analyse demonstrated that all isolates had three plasmids: 110, 70 and 9.5 kb, which are present in Y. pestis strains.

  5. Complete genome sequence of Bacillus thuringiensis tenebrionis 4AA1, a typical strain with toxicity to Coleopteran insects.

    Science.gov (United States)

    Gao, Qiuling; Zheng, Jinshui; Zhu, Lei; Ruan, Lifang; Peng, Donghai; Sun, Ming

    2015-06-20

    Bacillus thuringiensis serovar morrisoni biovar tenebrionis has been developed as an bioinsecticide to control Coleopteran insects in agriculture and forestry for a few decades. Its major crystal protein Cry3Aa was also applied to transgenic crops. Here we report the complete genome sequence of strain tenebrionis 4AA1, which has one chromosome of 5,652,292bp and six plasmids. Two crystal protein genes, cry3Aa and cry15Aa, locate on one single plasmid named pBMB51. This strain also possesses plentiful virulence factors besides crystal proteins. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. A numerical taxonomic study of species of Vibrio isolated from the aquatic environment and birds in Kent, England.

    Science.gov (United States)

    West, P A; Lee, J V; Bryant, T N

    1983-10-01

    A numerical taxonomic study has been carried out to confirm the identity of strains of the family Vibrionaceae isolated during an ecological study. A total of 237 strains were studied including 148 from the aquatic environment, 6 from estuarine birds, 1 from sheep faeces, and 61 control cultures. Duplicates of 21 of the strains were randomly selected and included to estimate test and operator error. Taxonomic resemblance was estimated on the basis of 148 characters using Euclidean distance. The taxonomic position of some strains was reevaluated using the pattern different coefficient. Strains were clustered by three methods, all of which gave similar results. The estimated average probability of test error was 1.5%. Strains previously identified as Vibrio anguillarum fell into four distinct phenons corresponding to V. anguillarum biovar I, 'V. anguillarum biovar II', V. diazotrophicus, and strains pathogenic to oyster larvae. The latter group characteristically degraded xanthine and probably represents a new species. The phenon corresponding to V. cholerae included the type strain, strains of human origin, and strains isolated in the United Kingdom from birds and the aquatic environment. Some strains of V. cholerae were luminous. Other phenons were identified as V. metschnikovii, V. fluvialis, and Aeromonas spp.

  7. Biochemical and Pathogenic Properties of Shewanella alga and Shewanella putrefaciens

    Science.gov (United States)

    Khashe, Shideh; Janda, J. Michael

    1998-01-01

    We characterized 49 strains of Shewanella spp. from clinical (n = 31) and nonhuman (n = 18) sources. Most Shewanella alga organisms (Gilardi biovar 2; Centers for Disease Control and Prevention [CDC] biotype 2) originated from clinical material (92%), failed to produce acid from carbohydrates other than d-ribose, and were biochemically and enzymatically fairly homogeneous. In contrast, Shewanella putrefaciens organisms (Gilardi biovars 1 and 3; CDC biotype 1) were more often associated with nonhuman sources (70%), were able to utilize a number of sugars (sucrose, l-arabinose, and maltose), and were found to exhibit wider variations in biochemical characteristics; three biotypes within S. putrefaciens were detected. Notable differences between the two species in enzymatic activity, determined with the API-ZYM system (bioMérieux, Hazelwood, Mo.), and cellular fatty acid profiles, determined by the MIDI system (Microbial ID Inc., Newark, Del.), were also detected. Pathogenicity studies of mice indicate that S. alga appears to be the more virulent species, possibly due to the production of a hemolytic substance. PMID:9508312

  8. Aislamiento y caracterización de cepas de Bacillus spp. con actividad contra Tetranychus urticae Koch en cultivos comerciales de rosas

    Directory of Open Access Journals (Sweden)

    Isabel Larrea-Izurieta

    2015-11-01

    Full Text Available One of the species of mites that cause considerable qualitative and quantitative losses in roses growing under greenhouses in Ecuador is Tetranychus urticae, where conventional agrochemicals control is not effective; therefore seeks to identify strains of Bacillus spp. Isolated from T. urticae and determine their anatomical pathogenic scenarios for future control with bacteria. The field phase took place in Naranjo Roses S.A. in Latacunga in a growing roses under organic conditions, where they were collected sheets of each third of six plants with presence of T. urticae Koch. The samples were taken to be processed in Plantsphere Laboratories (PSL in Quito. They were identified and quantified the different stages of the pest and some individuals were isolated for the presence of pathogenic strains of Bacillus spp., which were isolated, purified and identified. Check treatments of pathogenic were strains, distilled water (control and Bacillus thuringiensis biovar acari (positive control. Pathogenic events were evaluated in adult females of T. urticae by citohistochemistry, where breakout of the outer walls, precipitation of cell contents and cuticular malformations were reported. It was determined that the largest numbers of pest individuals are located in the lower third (59.4% with greater presence of eggs (63.3%. Using principal component analysis (PCA of the treatments, the PSL 104, 113, 114 and Bacillus thuringiensis biovar acari was determined as the most efficient Biocatalytic Effectors (EBc©.

  9. Anti-Brucella Antibodies in Moose (Alces alces gigas), Muskoxen (Ovibos moschatus), and Plains Bison (Bison bison bison) in Alaska, USA.

    Science.gov (United States)

    Nymo, Ingebjørg Helena; Beckmen, Kimberlee; Godfroid, Jacques

    2016-01-01

    We used an indirect enzyme-linked immunosorbent assay (iELISA) and the rose bengal test (RBT) to test for anti-Brucella antibodies in moose (Alces alces gigas), muskoxen (Ovibos moschatus), and plains bison (Bison bison bison) from various game management units (GMUs) in Alaska, US, sampled from 1982 to 2010. A portion of the sera had previously been tested with the standard plate test (SPT), the buffered Brucella antigen (BBA) card test, and the card test (CARD). No antibody-positive plains bison were identified. Anti-Brucella antibodies were detected in moose (iELISA, n=4/87; RBT, n=4/87; SPT, n=4/5; BBA, n=4/4) from GMU 23 captured in 1992, 1993, and 1995 and in muskoxen (iELISA, n=4/52; RBT, n=4/52; CARD, n=4/35) from GMUs 26A and 26B captured in 2004, 2006, and 2007. A negative effect of infection on the health of individuals of these species is probable. The presence of antibody-positive animals from 1992 to 2007 suggests presence of brucellae over time. The antibody-positive animals were found in northern Alaska, an area with a historically higher prevalence of Brucella-positive caribou, and a spillover of Brucella suis biovar 4 from caribou may have occurred. Brucella suis biovar 4 causes human brucellosis, and transmission from consumption of moose and muskoxen is possible.

  10. Vibrios among patients of good socioeconomic conditions during the cholera epidemic in Recife, Brazil Vibriões coléricos e não coléricos entre pacientes de boas condições sódo-econômicas durante a epidemia de coléra no Recife, Brasil

    Directory of Open Access Journals (Sweden)

    Vera Magalhães

    1993-08-01

    Full Text Available Between March and July, 1992, we screened for Vibrio all fecal samples submitted for bacteriologic diagnosis at a private clinical laboratory in Recife. Of 1435 cultures examined only 1 (0.07% was positive for V.cholerae 01, biovar Eltor, serovar Inaba, but 17 (1.2% yielded non-cholera Vibrio (V.cholerae non-01; V.fluvialis; V.furnissii, V.parahaemolyticus and Vibrio spp. Thus, V.cholerae 01, differently of other enteropathogenic vibrios, spared individuals of good socioeconomic conditions even during the cholera epidemic, which made hundreds of victims in the neighboring slums.Entre março e julho de 1992, pesquisou-se Vibrio em todos os espécimes fecais enviados para diagnóstico bacteriológico a um laboratório clínico privado do Recife. De 1435 culturas examinadas apenas 1 (0.07% foi positiva para V.cholerae 01, biovar Eltor, sorovar Inaba, porém 17 (1,2% forneceram outras espécies de Vibrio (V.cholerae nao-01; V.fluvialis; V.furnissii; V.parahaemolyticus e Vibrio spp. Portanto, V.cholerae 01, diferentemente de outros vibriões entero patogênicos, poupou indivíduos de boas condições sócio-econômicas, mesmo durante uma epidemia de cólera que atingiu centenas de pessoas nas favelas vizinhas.

  11. Ensifer meliloti bv. lancerottense establishes nitrogen-fixing symbiosis with Lotus endemic to the Canary Islands and shows distinctive symbiotic genotypes and host range.

    Science.gov (United States)

    León-Barrios, Milagros; Lorite, María José; Donate-Correa, Javier; Sanjuán, Juan

    2009-09-01

    Eleven strains were isolated from root nodules of Lotus endemic to the Canary Islands and they belonged to the genus Ensifer, a genus never previously described as a symbiont of Lotus. According to their 16S rRNA and atpD gene sequences, two isolates represented minority genotypes that could belong to previously undescribed Ensifer species, but most of the isolates were classified within the species Ensifer meliloti. These isolates nodulated Lotus lancerottensis, Lotus corniculatus and Lotus japonicus, whereas Lotus tenuis and Lotus uliginosus were more restrictive hosts. However, effective nitrogen fixation only occurred with the endemic L. lancerottensis. The E. meliloti strains did not nodulate Medicago sativa, Medicago laciniata Glycine max or Glycine soja, but induced non-fixing nodules on Phaseolus vulgaris roots. nodC and nifH symbiotic gene phylogenies showed that the E. meliloti symbionts of Lotus markedly diverged from strains of Mesorhizobium loti, the usual symbionts of Lotus, as well as from the three biovars (bv. meliloti, bv. medicaginis, and bv. mediterranense) so far described within E. meliloti. Indeed, the nodC and nifH genes from the E. meliloti isolates from Lotus represented unique symbiotic genotypes. According to their symbiotic gene sequences and host range, the Lotus symbionts would represent a new biovar of E. meliloti for which bv. lancerottense is proposed.

  12. Swine brucellosis: current perspectives

    Directory of Open Access Journals (Sweden)

    Olsen SC

    2016-12-01

    Full Text Available SC Olsen, FM Tatum Infectious Bacterial Diseases of Livestock Research Unit, National Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Ames, IA, USA Abstract: Brucella suis is a significant zoonotic species that is present in domestic livestock and wildlife in many countries worldwide. Transmission from animal reservoirs is the source of human infection as human-to-human transmission is very rare. Although swine brucellosis causes economic losses in domestic livestock, preventing human infection is the primary reason for its emphasis in disease control programs. Although disease prevalence varies worldwide, in areas outside of Europe, swine brucellosis is predominantly caused by B. suis biovars 1 and 3. In Europe, swine are predominantly infected with biovar 2 which is much less pathogenic in humans. In many areas worldwide, feral or wild populations of swine are important reservoir hosts. Like other Brucella spp. in their natural host, B. suis has developed mechanisms to survive in an intracellular environment and evade immune detection. Limitations in sensitivity and specificity of current diagnostics require use at a herd level, rather for individual animals. There is currently no commercial vaccine approved for preventing brucellosis in swine. Although not feasible in all situations, whole-herd depopulation is the most effective regulatory mechanism to control swine brucellosis. Keywords: livestock, transmission, pathogenicity, vaccine, host, infection

  13. Improved diagnostic PCR assay for Actinobacillus pleuropneumoniae based on the nucleotide sequence of an outer membrane lipoprotein

    DEFF Research Database (Denmark)

    Gram, Trine; Ahrens, Peter

    1998-01-01

    The gene (omlA) coding for an outer membrane protein of Actinobacillus pleuropneumoniae serotypes 1 and 5 has been described earlier and has formed the basis for development of a specific PCR assay, The corresponding regions of all 12 A. pleuropneumoniae reference strains of biovar 1 were sequenc...... and sensitivity of this PCR compared to those of culture suggest the use of this PCR for routine identification of A. pleuropneumoniae.......The gene (omlA) coding for an outer membrane protein of Actinobacillus pleuropneumoniae serotypes 1 and 5 has been described earlier and has formed the basis for development of a specific PCR assay, The corresponding regions of all 12 A. pleuropneumoniae reference strains of biovar 1 were sequenced...... species related to A. pleuropneumoniae or isolated from pigs were assayed. They were all found negative in the PCR, as were tonsil cultures from 50 pigs of an A. pleuropneumoniae-negative herd. The sensitivity assessed by agarose gel analysis of the PCR product was 10(2) CFU/PCR test tube. The specificity...

  14. Skin and soft-tissue infections caused by Aeromonas species.

    Science.gov (United States)

    Chao, C M; Lai, C C; Tang, H J; Ko, W C; Hsueh, P-R

    2013-04-01

    This study investigated the clinical characteristics of patients with skin and soft-tissue infections (SSTIs) due to Aeromonas species. Patients with SSTIs caused by Aeromonas species during the period from January 2009 to December 2011 were identified from a computerized database of a regional hospital in southern Taiwan. The medical records of these patients were retrospectively reviewed. A total of 129 patients with SSTIs due to Aeromonas species were identified. A. hydrophila (n = 77, 59.7 %) was the most common pathogen, followed by A. veronii biovar sobria (n = 22, 17.1 %), A. veronii biovar veronii (n = 20, 15.5 %), A. caviae (n = 9, 7.0 %), and A. schubertii (n = 1, 0.8 %). The most common isolates obtained from patients with polymicrobial infections were Klebsiella species (n = 33), followed by Enterococcus spp. (n = 24), Enterobacter spp. (n = 21), Escherichia coli (n = 17), Staphylococcus spp. (n = 17), Streptococcus spp. (n = 17), and Acinetobacter spp. (n = 15). Liver cirrhosis and concomitant bacteremia were more common among patients with monomicrobial Aeromonas SSTIs than among patients with polymicrobial SSTIs. Nine (7 %) patients required limb amputations. The in-hospital mortality rate was 1.6 %. In conclusion, Aeromonas species should be considered as important causative pathogens of SSTIs, and most infections are polymicrobial. In addition, the clinical presentation differs markedly between patients with monomicrobial and those with polymicrobial Aeromonas SSTIs.

  15. Interaction of Aeromonas strains with lactic acid bacteria via Caco-2 cells.

    Science.gov (United States)

    Hatje, E; Neuman, C; Katouli, M

    2014-01-01

    The genus Aeromonas includes some species that have now been identified as human pathogens of significant medical importance. We investigated the ability of 13 selected Aeromonas strains belonging to nine species isolated from clinical cases (n = 5), environmental waters (n = 5), and fish (n = 3) to adhere to and translocate Caco-2 cells in the absence and presence of two lactic acid bacteria (LAB), i.e., Lactobacillus acidophilus and Bifidobacterium breve. Aeromonas isolates were also assessed for their cytotoxicity, the presence of virulence genes, and hemolysin production. Among the clinical isolates, one strain of Aeromonas veronii biovar veronii and two strains of Aeromonas hydrophila carried cytotoxin (act), heat-labile toxin (alt), hemolysin (hlyA), and aerolysin (aerA) genes, were cytotoxic to Vero cells, produced hemolysin, and showed higher adherence to Caco-2 cells. In contrast, this was seen in only one environmental strain, a strain of A. veronii biovar sobria. When Aeromonas strains were coinoculated with LAB onto Caco-2 cells, their level of adhesion was reduced. However, their rate of translocation in the presence of LAB increased and was significantly (P Aeromonas and LAB strains could have a detrimental effect on the Caco-2 cells, allowing the Aeromonas to translocate more readily, or the presence of the LAB stimulated the Aeromonas strains to produce more toxins and/or increase their translocation rate.

  16. Colonization of streptomycin-treated mice by Aeromonas species.

    Science.gov (United States)

    Sanderson, K; Ghazali, F M; Kirov, S M

    1996-03-01

    Streptomycin-treated adult mice were investigated as a possible model for studying the enteropathogenicity of Aeromonas species. C57BL mice pre-treated with streptomycin (5.0 g/L drinking water, 48 hours) received a single intragastric dose (10(10) bacteria /10.5 mL) of one of six well-characterized, toxin-producing, human diarrhoeal isolates of A. veronii biovar sobria (n = 3) or A. hydrophila (n = 3). Their faeces were examined for Aeromonas for 10 days post-challenge. All strains colonized the antibiotic-treated mice. Colonization did not occur in mice which did not receive streptomycin. Strains of A. hydrophila were recovered in greater numbers than strains of A. veronii biovar sobria, and colonized ( > or = 10(3) cfu/g of faeces) a greater proportion of mice at day 10. Strains of the latter species, however, were more adherent in cell line assays used as models of intestinal adhesion. A. hydrophila strains localized in the large intestine and appeared not to be cell associated. This study, therefore, points to species-related differences in intestinal colonization mechanisms. The streptomycin-treated adult mouse model may prove useful for further investigation of some of these mechanisms. Diarrhoeal symptoms were, however, not produced in this model.

  17. First Report of Tumorigenic Agrobacterium radiobacter on Raspberry in Serbia

    Directory of Open Access Journals (Sweden)

    Svetlana Milijašević

    2007-01-01

    Full Text Available During the spring of 2003, gall symptoms on the roots and crowns of young raspberry plants cv. Vilamette were observed near Valjevo. Phytopathogenic bacteria were isolated from diseased plant samples. Based on the pathogenic, morphological, differential biochemicaland physiological characteristics, the isolated strains were identified as tumorigenic Agrobacterium radiobacter (biovar 1 Agrobacterium. In order to confirm the identity of isolated strains by polymerase chain reaction (PCR primers complementary to tms2 genelocated on the Ti plasmid were used. In the first PCR protocol using a tms2F1 + tms2R2 primer pair, 617 bp products specific for tumorigenic Agrobacterium strains were amplified. The second PCR protocol, using a tms2F1 + tms2B primer pair, amplified the expected 458 bp products. On the basis of multiplex PCR with primers complementary to chromosomal gene coding for 23S rRNA, the isolated strains were classified as biovar 1 Agrobacterium (A. radiobacter. This is the first report of tumorigenic A. radiobacter on raspberry in Serbia.

  18. 辅酶Q10高产菌株的诱变选育%Induced Mutation Breeding and Screening of a Coenzyme QlO-Producing Strain

    Institute of Scientific and Technical Information of China (English)

    曹燕妮; 岳田利; 袁亚红; 高振鹏

    2012-01-01

    以豌豆根瘤菌(Rhizobium leguminosarum 11723)为出发菌株,利用紫外-LiCl和超声波进行诱变,以期获得高产辅酶Q10菌株。结果表明:lg/LLiCl诱变能显著提高菌株的正突变率,超声波诱变会引起细胞壁结构与构成发生改变。通过罗红霉素初筛和摇床复筛,获得辅酶Q10突变株C40-05,胞内辅酶QlO产量为1.198mg/g干菌,比出发菌株(0.389mg/g)提高了208%。菌株经5次传代培养,胞内辅酶Q10产量下降了2.67%,突变株遗传形状稳定,可作为辅酶Q10生产菌株。%Rhizobium leguminosarum 1.1723 was mutagenized by means of LiCl treatment followed by UV irradiation or ultrasonic treatment alone to yield coenzyme Q10-producing strains. The results showed that 1 g/L LiCl could obviously increase the positive mutation rate and that ultrasonic treatment could change cell wall structure of Rhizobium leguminosarum. A mutant C40-05 with high productivity of coenzyme Q10 was obtained through preliminary screening with roxithromycin and secondary screening by means of shake flask cultivation. Its coenzyme Q10 yield was up to 1.198 mg/g, which revealed a 208% increase compared with the original stain. Only 2.67% reduction in coenzyme Q10 yield of the mutant was observed after the fifth passage. Therefore, the obtained mutant is a stable strain that deserves to be studied further.

  19. Cultivar and Rhizobium Strain Effects on the Symbiotic Performance of Pea (Pisum sativum)

    DEFF Research Database (Denmark)

    Skøt, Leif

    1983-01-01

    content and dry weight/N ratio. At harvest 63 days after planting, cultivars accounted for 75% of the variation in dry weight, while the Rhizobium strains accounted for 63% of the variation in N-content and 70% of the variation in dry weight/N ratio. Cultivar × strain interactions were statistically......The symbiotic performance of four pea (Pisum sativum L.) cultivars in combination with each of four strains of Rhizobium leguminosarum was studied in growth chamber experiments in order to estimate the effects of cultivars, strains and cultivar × strain interaction on the variation in dry weight, N...... significant, but of minor quantitative importance, accounting for 5–15% of the total variation. Rhizobium strains also influenced the partitioning of N between reproductive and vegetative plant parts and between root and shoot biomass....

  20. Virus-induced gene silencing (VIGS) as a reverse genetic tool to study development of symbiotic root nodules

    DEFF Research Database (Denmark)

    Kjær, Gabriela Didina Constantin; Grønlund, Mette; Stougaard, Jens

    2008-01-01

    was mediated by agroinfiltration and, 2 weeks later, a Rhizobium leguminosarum bv. viceae culture was added in order to induce root nodulation. At this time point, it was estimated that systemic silencing was established because leaves of reference plants inoculated with PEBV carrying a fragment of Phytoene...... desaturase displayed photo bleaching. Three weeks after Rhizobium spp. application, plants inoculated with a control vector nodulated normally, whereas nodulation was almost eliminated in plants inoculated with a vector carrying PsNinA and PsNinC. For plants inoculated with a vector carrying Ps......NinB, nodulation was reduced by at least 45%. Down-regulation of PsNin transcripts in plants inoculated with vectors carrying PsNin cDNA fragments was confirmed and these plants displayed a relative increase in the root/shoot ratio, as expected if nitrogen fixation had been impaired....

  1. Genetic Factors in Rhizobium Affecting the Symbiotic Carbon Costs of N2 Fixation and Host Plant Biomass Production

    DEFF Research Database (Denmark)

    Skøt, L.; Hirsch, P. R.; Witty, J. F.

    1986-01-01

    The effect of genetic factors in Rhizobium on host plant biomass production and on the carbon costs of N2 fixation in pea root nodules was studied. Nine strains of Rhizobium leguminosarum were constructed, each containing one of three symbiotic plasmids in combination with one of three different...... with the background of B151. The relationship between nitrogenase activity, carbon costs of N2 fixation and host plant biomass production is discussed....... the lowest carbon costs of N2 fixation (7.10–8.10 μmol C/μmol N2), but shoot dry weight of those plants was also smaller than that of plants nodulated by strains with the background of B151 or JI8400. Nodules formed by these two strain types had carbon costs of N2 fixation varying between 11.26 and 13...

  2. Response of Phaseolus vulgaris cv. Mantequilla to inoculation of Rhizobium native strains of the Ecuador in greenhouse native races of the Ecuador

    Directory of Open Access Journals (Sweden)

    Klever Iván Granda Mora

    2016-10-01

    Full Text Available The development of biofertilizers based on Rhizobium strains for common bean (Phaseolus vulgaris L. requires studies about bacterial interaction with target cultivars. For these reason, the aim of this paper was to determine the effect of the inoculation of Rhizobium native strains, isolated from southern Ecuador, on P. vulgaris cultivar Mantequilla. An assay was performed in greenhouse. It were evaluated the parameters of nodulation, biomass, nitrogen fixation and efficiency of the symbiosis. All inoculated strains were able to nodulate bean seedlings. The total number of nodules, nodular biomass and plant biomass, were favourably affected by inoculation of Rhizobium strains. The best results were obtained with R. mesoamericanum NAM1, R. leguminosarum COL 6 and R. etli PIN 1 strains. The experimental evidences shows the potential of native strains of Rhizobium for it use as biofertilizers because they are able to raise the rates of nitrogen fixation in common bean in southern Ecuador.

  3. Avaliação da biodiversidade de rizóbios simbiontes do feijoeiro (Phaseolus vulgaris L. em Santa Catarina Assessment of biodiversity in rhizobia symbionts of common bean (Phaseolus vulgaris L. in Santa Catarina, Brazil

    Directory of Open Access Journals (Sweden)

    Priscila Stocco

    2008-06-01

    Full Text Available Os solos brasileiros, em geral, apresentam uma população abundante de rizóbios capazes de nodular e fixar N2 em simbiose com o feijoeiro (Phaseolus vulgaris L.; contudo, a diversidade dessas bactérias ainda é pouco conhecida. Este estudo teve por objetivo conhecer a biodiversidade de microssimbiontes do feijoeiro em Santa Catarina e, para isso, foram obtidos 117 isolados de nódulos de plantas coletadas em campo, em 23 áreas do extremo oeste, do meio oeste e do planalto sul catarinense. Com base nos atributos morfofisiológicos, os isolados foram classificados em nove grupos. Pela análise dos perfis de DNA após a amplificação (PCR com o "primer" BOX, que codifica regiões conservadas e repetidas do genoma, 107 perfis distintos foram agrupados em um nível final de similaridade de apenas 26,9 %. Os perfis obtidos pela amplificação do gene 16S ribossômico - referência na taxonomia atual de procariotos - seguida pela digestão com três enzimas de restrição (técnica de RFLP-PCR, resultaram em seis agrupamentos principais e cinco bactérias isoladas. As populações consistiram de 17,1 % de Rhizobium tropici, 35,9 % de R. etli, 32,5 % de R. leguminosarum, 1,7 % de R. giardinii e 12,8 % com perfis distintos das espécies descritas de rizóbios de feijoeiro. R. tropici predominou em solos ácidos do meio oeste e do planalto sul, R. leguminosarum não foi detectado no extremo oeste e R. etli ocorreu nas três regiões, essas duas últimas espécies em solos menos ácidos. Os resultados enfatizam a diversidade genética elevada de rizóbios, inter e intra-específica, nos solos catarinenses, inclusive com a indicação de novas espécies.Brazilian soils usually present a great number of populations of rhizobial bacteria capable of nodulating and fixing N2 in symbiosis with common bean (Phaseolus vulgaris L., but the diversity of these bacteria is still poorly known. This study aimed to assess the biodiversity of micro-symbionts of

  4. Rhizobium strains differ considerably in outer membrane permeability and polymyxin B resistance.

    Science.gov (United States)

    Komaniecka, Iwona; Zamłyńska, Katarzyna; Zan, Radosław; Staszczak, Magdalena; Pawelec, Jarosław; Seta, Irena; Choma, Adam

    2016-01-01

    Six rhizobium (Rhizobium leguminosarum bv. Trifolii TA1, Sinorhizobium meliloti 1021, Mesorhizobium huakuii IFO 15243(T), Ochrobactrum lupini LUP 21(T), Bradyrhizobium japonicum USDA110 and B. elkanii USDA 76) and two Escherichia coli strains (E. coli ATCC 25922 and E. coli HB 101) were compared in respect to polymyxin B and EDTA resistance, as well as bacterial outer membrane (OM) permeability to a fluorescent hydrophobic agent (N-phenyl-1-naphthylamine - NPN). TEM (Transmission Electron Microscopy) and a microbial test demonstrated that all the rhizobia were much more resistant to polymyxin B in comparison with E. coli strains. EDTA and polymyxin B enhance permeability of B. japonicum and O. lupini OM. Other rhizobia incorporated NPN independently of the presence of membrane-deteriorating agents; however, the level of fluorescence (measured as NPN absorption) was strain dependent.

  5. [The Effect of Cadmium on the Efficiency of Development of Legume-Rhizobium Symbiosis].

    Science.gov (United States)

    Chuhukova, O V; Postrigan, B N; Baimiev, A Kh; Chemeris, A V

    2015-01-01

    Screening of nodule bacteria (rhizobia) forming symbiotic relationships with legumes has been performed in order to isolate strains resistant to cadmium ions in a wide range of concentrations (6-132 mg/kg). The effect ofcadmium salts (6, 12, 24 mg/kg) on the legume-rhizobium symbiosis ofthe pea Pisum sativum L. with Rhizobium leguminosarum and of the fodder galega Galega orientalis Lam. with Rhizobium galegae has been studied under experimental laboratory conditions. No statistically significant differences have been revealed in the growth and biomass of plants with regard to the control in the range of concentrations given above. However, it was found that cadmium inhibited nodulation in P. sativum and stimulated it in G. orientalis.

  6. Seven enzymes create extraordinary molecular complexity in an uncultivated bacterium

    Science.gov (United States)

    Freeman, Michael F.; Helf, Maximilian J.; Bhushan, Agneya; Morinaka, Brandon I.; Piel, Jörn

    2016-11-01

    Uncultivated bacteria represent a massive resource of new enzymes and bioactive metabolites, but such bacteria remain functionally enigmatic. Polytheonamides are potent peptide cytotoxins produced by uncultivated bacteria that exist as symbionts in a marine sponge. Outside glycobiology, polytheonamides represent the most heavily post-translationally modified biomolecules that are derived from amino acids. The biosynthesis of polytheonamides involves up to 50 site-specific modifications to create a membrane-spanning β-helical structure. Here, we provide functional evidence that only seven enzymes are necessary for this process. They iteratively catalyse epimerization, methylation and hydroxylation of diverse amino acids. To reconstitute C-methylation, we employed the rarely used heterologous host Rhizobium leguminosarum to invoke the activities of two cobalamin-dependent C-methyltransferases. We observed 44 of the modifications to systematically unravel the biosynthesis of one of the most densely modified and metabolically obscure ribosome-derived molecules found in nature.

  7. Seven enzymes create extraordinary molecular complexity in an uncultivated bacterium

    Science.gov (United States)

    Freeman, Michael F.; Helf, Maximilian J.; Bhushan, Agneya; Morinaka, Brandon I.; Piel, Jörn

    2017-04-01

    Uncultivated bacteria represent a massive resource of new enzymes and bioactive metabolites, but such bacteria remain functionally enigmatic. Polytheonamides are potent peptide cytotoxins produced by uncultivated bacteria that exist as symbionts in a marine sponge. Outside glycobiology, polytheonamides represent the most heavily post-translationally modified biomolecules that are derived from amino acids. The biosynthesis of polytheonamides involves up to 50 site-specific modifications to create a membrane-spanning β-helical structure. Here, we provide functional evidence that only seven enzymes are necessary for this process. They iteratively catalyse epimerization, methylation and hydroxylation of diverse amino acids. To reconstitute C-methylation, we employed the rarely used heterologous host Rhizobium leguminosarum to invoke the activities of two cobalamin-dependent C-methyltransferases. We observed 44 of the modifications to systematically unravel the biosynthesis of one of the most densely modified and metabolically obscure ribosome-derived molecules found in nature.

  8. Against friend and foe: type 6 effectors in plant-associated bacteria.

    Science.gov (United States)

    Ryu, Choong-Min

    2015-03-01

    Bacterial secretion systems play critical roles in communication with neighboring bacteria and in the modulation of host immune responses via the secretion of small proteins called effectors. Several secretion systems have been identified and these are denoted types I-VII. Of these, the type VI secretion system (T6SS) and its effectors were only recently elucidated. Most studies on the role and significance of the T6SS and its effectors have focused on human pathogens. In this review, type 6 effectors from plant-associated beneficial and pathogenic bacteria are discussed, including effectors from Agrobacterium tumefaciens, Dickeya dadanti, Rhizobium leguminosarum, Pectobacterium atroseptium, Ralstonia solanacearum, Pseudomonas syringae, Pseudomonas fluorescens, and Pseudomonas protegens. Type 6 effectors act in symbiosis, biofilm formation, virulence, and interbacterial competition. Understanding the impact of type 6 effectors on pathogenesis will contribute to the management of bacterial pathogens in crop plants by allowing the manipulation of intra and inter-specific interactions.

  9. Dicty_cDB: Contig-U10150-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available :none) Tropheryma whipplei str. Twist, ... 39 0.62 CP000614_1895( CP000614 |pid:none) Burkholderia vietnam...:none) Rhizobium leguminosarum bv. vici... 41 0.096 AL939124_135( AL939124 |pid:none) Streptomyces coelicolor A3(2) co...:none) Thermoanaerobacter tengcongensi... 56 3e-06 CP000246_1907( CP000246 |pid:none) Clostridium perfrin...:none) Persephonella marina EX-H1, comp... 42 0.056 AE017125_523( AE017125 |pid:none) Helicobac....056 CP000744_2665( CP000744 |pid:none) Pseudomonas aeruginosa PA7, com... 42 0.056 CP000941_323( CP000941 |pid:none) Xylella fastidi

  10. Diversity pattern of nitrogen fixing microbes in nodules of Trifolium arvense (L. at different initial stages of ecosystem development

    Directory of Open Access Journals (Sweden)

    M. Schloter

    2012-09-01

    Full Text Available Legumes can be considered as pioneer plants during ecosystem development, as they form a symbiosis with different nitrogen fixing rhizobia species, which enable the plants to grow on soils with low available nitrogen content. In this study we compared the abundance and diversity of nitrogen fixing microbes based on the functional marker gene nifH, which codes for a subunit of the Fe-protein of the dinitrogenase reductase, in nodules of different size classes of Trifolium arvense (L.. Additionally, carbon and nitrogen contents of the bulk soil and plant material were measured. Plants were harvested from different sites, reflecting 2 (2a and 5 (5a yr of ecosystem development, of an opencast lignite mining area in the south of Cottbus, Lower Lusatia (Germany where the artificial catchment "Chicken Creek" was constructed to study the development of terrestrial ecosystems. Plants from the 5a site revealed higher amounts of carbon and nitrogen, although nifH gene abundances in the nodules and carbon and nitrogen contents between the two soils did not differ significantly. Analysis of the nifH clone libraries showed a significant effect of the nodule size on the community composition of nitrogen fixing microbes. Medium sized nodules (2–5 mm contained a uniform community composed of Rhizobium leguminosarum bv. trifolii, whereas the small nodules (Rhizobium nifH gene sequences. Regarding the impact of the soil age on the community composition a clear distinction between the small and the medium nodules can be made. While clone libraries from the medium nodules were pretty similar at both soil ages, soil age had a significant effect on the community compositions of the small nodules, where the proportion of R. leguminosarum bv. trifolii increased with soil age.

  11. Diversity pattern of nitrogen fixing microbes in nodules of Trifolium arvense (L.) at different initial stages of ecosystem development

    Science.gov (United States)

    Schulz, S.; Engel, M.; Fischer, D.; Buegger, F.; Elmer, M.; Welzl, G.; Schloter, M.

    2013-02-01

    Legumes can be considered as pioneer plants during ecosystem development, as they form a symbiosis with different nitrogen fixing rhizobia species, which enable the plants to grow on soils with low available nitrogen content. In this study we compared the abundance and diversity of nitrogen fixing microbes based on the functional marker gene nifH, which codes for a subunit of the Fe-protein of the dinitrogenase reductase, in nodules of different size classes of Trifolium arvense (L.). Additionally, carbon and nitrogen contents of the bulk soil and plant material were measured. Plants were harvested from different sites, reflecting 2 (2a) and 5 (5a) yr of ecosystem development, of an opencast lignite mining area in the south of Cottbus, Lower Lusatia (Germany) where the artificial catchment "Chicken Creek" was constructed to study the development of terrestrial ecosystems. Plants from the 5a site revealed higher amounts of carbon and nitrogen, although nifH gene abundances in the nodules and carbon and nitrogen contents between the two soils did not differ significantly. Analysis of the nifH clone libraries showed a significant effect of the nodule size on the community composition of nitrogen fixing microbes. Medium sized nodules (2-5 mm) contained a uniform community composed of Rhizobium leguminosarum bv. trifolii, whereas the small nodules (<2 mm) consisted of a diverse community including clones with non-Rhizobium nifH gene sequences. Regarding the impact of the soil age on the community composition a clear distinction between the small and the medium nodules can be made. While clone libraries from the medium nodules were pretty similar at both soil ages, soil age had a significant effect on the community compositions of the small nodules, where the proportion of R. leguminosarum bv. trifolii increased with soil age.

  12. Diversity pattern of nitrogen fixing microbes in nodules of Trifolium arvense (L. at different initial stages of ecosystem development

    Directory of Open Access Journals (Sweden)

    M. Schloter

    2013-02-01

    Full Text Available Legumes can be considered as pioneer plants during ecosystem development, as they form a symbiosis with different nitrogen fixing rhizobia species, which enable the plants to grow on soils with low available nitrogen content. In this study we compared the abundance and diversity of nitrogen fixing microbes based on the functional marker gene nifH, which codes for a subunit of the Fe-protein of the dinitrogenase reductase, in nodules of different size classes of Trifolium arvense (L.. Additionally, carbon and nitrogen contents of the bulk soil and plant material were measured. Plants were harvested from different sites, reflecting 2 (2a and 5 (5a yr of ecosystem development, of an opencast lignite mining area in the south of Cottbus, Lower Lusatia (Germany where the artificial catchment "Chicken Creek" was constructed to study the development of terrestrial ecosystems. Plants from the 5a site revealed higher amounts of carbon and nitrogen, although nifH gene abundances in the nodules and carbon and nitrogen contents between the two soils did not differ significantly. Analysis of the nifH clone libraries showed a significant effect of the nodule size on the community composition of nitrogen fixing microbes. Medium sized nodules (2–5 mm contained a uniform community composed of Rhizobium leguminosarum bv. trifolii, whereas the small nodules (Rhizobium nifH gene sequences. Regarding the impact of the soil age on the community composition a clear distinction between the small and the medium nodules can be made. While clone libraries from the medium nodules were pretty similar at both soil ages, soil age had a significant effect on the community compositions of the small nodules, where the proportion of R. leguminosarum bv. trifolii increased with soil age.

  13. 122例急性布鲁菌病患者血培养临床分析%Clinical analysis of 122 acute brucellosis patients' blood culture

    Institute of Scientific and Technical Information of China (English)

    刘卫华; 李福兴; 陈哲; 刘长民

    2016-01-01

    目的 分析急性布鲁菌病(简称布病)患者血培养结果和菌种分型,确定感染种型,进一步探讨布病患者临床表现及治疗效果.方法 选取2012、2013年在黑龙江省农垦总局总医院住院的122例(男性83例、女性39例)急性布病患者,年龄在6 ~ 73岁,平均年龄36.5岁.所有患者行血培养、血清学检查,并给予氨基糖苷类、喹诺酮类、头孢类抗生素治疗.结果 122例布病患者血培养均为羊种布鲁菌,其中羊种3型104例,羊种1型18例.所有受试者的血清学虎红平板凝集试验(rose bengal plate agglutination test,RBPT)均为阳性;血清试管凝集试验(serum tube agglutination test,SAT)各个效价在羊种1型和3型均匀分布,羊种1型主要集中在1∶800效价区,羊种3型主要集中在1∶400效价区;羊种1型与羊种3型的抗人球蛋白及半胱氨酸分布趋势相似,抗人球蛋白主要集中在1∶800效价区,半胱氨酸主要集中在1∶40效价区.所有患者均有典型的布病症状,并发症多(如脊柱炎、中毒性肝炎等).122例急性布病患者经治疗112例痊愈,10例好转.结论 黑龙江省人间布病由羊种菌1、3型引起,临床症状重且并发症多,早期诊断、早期治疗才能得到显著治疗效果.%Objective By studying the acute brucellosis patients' blood culture and the bacteria strains,we tried to confirm the bacteria strains,and to further explore the symptoms and the results of the treatment.Methods Totally 122 acute brucellosis patients were selected,who were in hospital in Heilongjiang Provincial Nongken General Hospital from 2012 to 2013.The patients aged 6-73 years old,whose average age was 36.5(including 83 males and 39 females).All of the subjects were detected in the aspects of blood culture and brucellosis serology,all of whom were treated with aminoglycoside,4-quinolones and cephalosporins.Results All the subjects were Brucella melitensis biovar,of which 104 were Brucella melitensis biovar

  14. Primera cita de dos especies de insectos sobre el cultivo de maní (Arachis hypogaea L. en Córdoba, Argentina First report of two species of insects on peanut crop (Arachis hypogaea L. in Córdoba, Argentina

    Directory of Open Access Journals (Sweden)

    G.T. Boito

    2006-12-01

    Full Text Available La Argentina es uno de los principales exportadores de maní tipo confitería, cuya mayor área de producción se encuentra en la provincia de Córdoba. Entre los años 2002 y 2005 se realizaron monitoreos sobre el cultivo, en las localidades de Charras y General Deheza, situadas en dicha área, para determinar la presencia de insectos que pudieran ocasionarle algún daño. En esta comunicación se cita por primera vez a Anomala testaceipennis Blanchard (Coleoptera-Melolonthidae- Rutelinae-Anomalini y Caliothrips phaseoli Hood (Thysanoptera-Thripidae-Panchaetothripinae causando daño sobre maní (Arachis hypogaea L. en Córdoba, Argentina. Los estados inmaduros de Anomala testaceipennis se identificaron sobre la base de características morfológicas, principalmente la disposición de las setas en el extremo abdominal (raster, y los adultos de ambas especies fueron identificados mediante el uso de claves taxonómicas especializadas. Debido a la importancia de la calidad del producto que se comercializa (maní tipo confitería para exportación es relevante cuantificar el daño que estos insectos provocan y si ello incide económicamente en la producción del cultivo.Argentina is among the main exporters of peanut and the principal production area is located in Cordoba province. This crop was monitored between 2002 and 2005 years in Charras and General Deheza to detect potentially damaging insects. In this communication, Anomala testaceipennis Blanchard (Coleoptera-Melolonthidae- Rutelinae-Anomalini and Caliothrips phaseoli Hood (Thysanoptera-Thripidae- Panchaetothripinae are reported for the first time causing damage on peanut (Arachis hypogaea in Cordoba, Argentina. The immature stages of the A. testaceipennis were identified through its morphologic characteristics, mainly of the abdominal extreme (raster, and the adults of both species were identified through the use of specialized taxonomy keys. Due to the importance of the quality of the

  15. Ação de tinturas e óleos essenciais de plantas medicinais sobre o crestamento bacteriano comum do feijoeiro e na produção de proteínas de indução de resistência

    Directory of Open Access Journals (Sweden)

    Sandra Cristina Vigo

    2009-12-01

    Full Text Available A exploração da atividade biológica de compostos secundários presentes nas tinturas ou em óleos essenciais de plantas podem representar, ao lado da indução de resistência, mais uma forma potencial de controle de doenças em plantas cultivadas. O presente trabalho objetivou avaliar o potencial de tinturas de Lippia alba, Lippia sidoides, Mikania glomerata, Equisetum sp. e Hedera helix e óleos essenciais de Rosmarinus officinalis e Cinnamomum zeylanicum nas atividades in vitro, in vivo e na produção de proteínas na indução de resistência, em plantas de feijão vagem cultivar Bragança. Os resultados obtidos demonstraram que as tinturas de L. alba e L. sidoides e os óleos essenciais (R. officinalis e C. zeylanicum apresentaram atividade in vitro aos isolados de Xanthomonas axonopodis pv. phaseoli. Todas as tinturas ensaiadas apresentaram menores valores do progresso da doença (AACPD, em relação à testemunha, merecendo destaque a tintura de L. alba, que estavam correlacionadas com os maiores teores de polifenoloxidase, peroxidase e proteínas solúveis totais, evidenciando uma possível indução de resistência. Os óleos essenciais não apresentaram diferença na AACPD e nem na indução de proteínas.Additionally to resistance inducers, the exploitation of secondary compounds biological activity present in plants alcohol extracts or essential oils could potential way to control diseases in cultivated plants. This aimed to evaluate the potential of Lippia alba, Lippia sidoides, Mikania glomerata, Equisetum sp. and Hedera helix alcohol extracts and, Rosmarinus officinalis and Cinnamomum zeylanicum essential oils on in vitro and in vivo activity, and protein production on resistance induction in snap beans Bragança cultivar. Results showed in vitro activity against Xanthomonas axonopodis pv. phaseoli for L. alba and L. sidoides extracts, and essential oils. Although all alcohol extracts have showed the lowest area under the

  16. Método generalizado de análise de dialelos desbalanceados Generalized method for analysis of unbalanced diallels

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    SÍLVIA AGRIPINA GONÇALVES E SILVA

    2000-10-01

    Full Text Available Apresenta-se um procedimento generalizado de estimação das capacidades geral e específica de combinação em cruzamentos dialélicos, com número desigual de repetições para tratamentos (genitores e combinações híbridas F1, avaliados em um delineamento com restrições na casualização. Neste caso, as médias ajustadas estimadas são interdependentes e heterocedásticas, devendo-se, para estimar os parâmetros desejados, utilizar o modelo linear generalizado de GaussMarkov. O objetivo deste trabalho foi a dedução teórica do método e sua aplicação a um exemplo prático. Foram analisados os dados obtidos de um dialelo completo, sem os recíprocos, envolvendo cinco genitores: CB 511687-1, CB 733753, Diamante Negro, Rosinha G2 e Compuesto Chimaltenango 2. Os genitores CB 733753, CB 511687-1 e Diamante Negro contribuem geneticamente para a resistência, enquanto Rosinha G2 e Compuesto Chimaltenango 2 contribuem para a suscetibilidade do feijoeiro ao crestamento-bacteriano comum. Na maioria dos cruzamentos analisados constatou-se a dominância parcial da suscetibilidade do feijoeiro a Xanthomonas axonopodis pv. phaseoli.A general procedure for estimation of general and specific combining ability in diallelic crosses with unequal number of replications for treatments (parents and F1 hybrid combinations, evaluated in a design with restricted randomization, is presented. In this case, the estimates of adjusted means are interdependent and heterocedastic, demanding the use of the GaussMarcov generalized linear model. The objective of this study was the theoretical deduction of the model and its application to a practical example. A complete diallel crossing without reciprocals was performed, including five parents: CB 511687-1, CB 733753, Diamante Negro, Rosinha G-2 and Compuesto Chimaltenango 2. The parents CB 511687-1, CB 733753 and Diamante Negro contribute genetically for resistance while Rosinha G-2 and Compuesto Chimaltenango 2

  17. Genomic studies of nitrogen-fixing rhizobial strains from Phaseolus vulgaris seeds and nodules.

    Science.gov (United States)

    Peralta, Humberto; Aguilar, Alejandro; Díaz, Rafael; Mora, Yolanda; Martínez-Batallar, Gabriel; Salazar, Emmanuel; Vargas-Lagunas, Carmen; Martínez, Esperanza; Encarnación, Sergio; Girard, Lourdes; Mora, Jaime

    2016-09-06

    Rhizobia are soil bacteria that establish symbiotic relationships with legumes and fix nitrogen in root nodules. We recently reported that several nitrogen-fixing rhizobial strains, belonging to Rhizobium phaseoli, R. trifolii, R. grahamii and Sinorhizobium americanum, were able to colonize Phaseolus vulgaris (common bean) seeds. To gain further insight into the traits that support this ability, we analyzed the genomic sequences and proteomes of R. phaseoli (CCGM1) and S. americanum (CCGM7) strains from seeds and compared them with those of the closely related strains CIAT652 and CFNEI73, respectively, isolated only from nodules. In a fine structural study of the S. americanum genomes, the chromosomes, megaplasmids and symbiotic plasmids were highly conserved and syntenic, with the exception of the smaller plasmid, which appeared unrelated. The symbiotic tract of CCGM7 appeared more disperse, possibly due to the action of transposases. The chromosomes of seed strains had less transposases and strain-specific genes. The seed strains CCGM1 and CCGM7 shared about half of their genomes with their closest strains (3353 and 3472 orthologs respectively), but a large fraction of the rest also had homology with other rhizobia. They contained 315 and 204 strain-specific genes, respectively, particularly abundant in the functions of transcription, motility, energy generation and cofactor biosynthesis. The proteomes of seed and nodule strains were obtained and showed a particular profile for each of the strains. About 82 % of the proteins in the comparisons appeared similar. Forty of the most abundant proteins in each strain were identified; these proteins in seed strains were involved in stress responses and coenzyme and cofactor biosynthesis and in the nodule strains mainly in central processes. Only 3 % of the abundant proteins had hypothetical functions. Functions that were enriched in the genomes and proteomes of seed strains possibly participate in the successful

  18. Albicampo, variedad de frijol de temporal para Valles Altos de la Mesa Central Albicampo, rainfed bean variety for the High Valleys of the Central Mexican Plateau

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    Dagoberto Garza-García

    2010-12-01

    Full Text Available Albicampo (Phaseolus vulgaris L. es una variedad de grano negro opaco pequeño, tipo Jamapa, liberada en 2010 por el programa de frijol del Campo Experimental Valle de México (CEVAMEX del Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias (INIFAP. Se obtuvo mediante una cruza simple, utilizando selección masal hasta la generación F4. En la F5 se realizó selección individual para resistencia a enfermedades, calidad de grano y características agronómicas. Esta variedad se distingue de otras del mismo tipo comercial, por su alto rendimiento, excelente calidad culinaria y alto contenido de proteína, así plasticidad fenológica que le permite adaptarse a zonas, tanto de crítico como de buen temporal de lluvia. Es resistente a antracnosis (Colletotrichum lindemuthianum Sacc & Magn. Briosi & Cav., tizón común (Xanthomonas campestris pv phaseoli (Smith Dye y pudrición de raíz (Pythium y Rhizoctonia, y tolerante a roya (Uromyces appendiculatus (Pers.:Pers. Unger. Es de ciclo intermedio (105 a 115 días a madurez, su hábito de crecimiento es tipo III (indeterminado, con guía corta y flores moradas. Albicampo expresa su máximo potencial en áreas desde 2000 hasta 2400 msnm, suelo profundo y un mínimo de 350 mm de precipitación pluvial.Albicampo (Phaseolus vulgaris L., a small opaque dry bean seed variety from the Jamapa class, was released in 2010 by the bean program of the INIFAP's Campo Experimental Valle de Mexico. It was obtained through a simple cross, using bulk selection to the F4 followed by individual selection in F5 for disease, quality and agronomic traits. It distinguishes from other varieties of the same commercial class because of its high yield (>2 t ha-1, excellent cooking quality and high protein content, as well as phenological plasticity which enables it to adapt itself from critical to good rain season. It is resistant to anthracnose (Colletotrichum lindemuthianum Sacc & Magn. Briosi & Cav

  19. TRATAMENTO DE SEMENTES DE ARROZ, TRIGO, FEIJÃO E SOJA COM UM PRODUTO FORMULADO À BASE DE CÉLULAS E DE METABÓLITOS DE Bacillus subtilis

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    E LAZZARETTI

    1997-01-01

    Full Text Available Um produto constituido de pó-molhável (PBBS formulado à base de células (60g e de metabólitos (60g de Bacillus subtilis, argila (480g, espalhante (7,92g e água (2400ml, moído e seco, mostrou-se semelhante aos tratamentos com fungicidas recomendados para o controle de Rhizoctonia solani, Aspergillus sp. e Sclerotinia sclerotiorum em sementes de feijão; Pyricularia oryzae e Rhinchosporium sativum em sementes de arroz; e Cercospora kikuchii, Phomopsis phaseoli e Fusarium spp. em sementes de soja. Para Dreschlera oryzae em arroz e Bipolaris sorokiniana, P. oryzae e Alternaria tenuis em sementes de trigo, o tratamento com o PBBS, embora não tenha se igualado ao tratamento com o fungicida padrão, diferiu estatisticamente do tratamento testemunha. A nodulação das raízes de feijão e soja por bactérias simbióticas, fixadoras de nitrogênio, não foi influenciada quando o PBBS foi aplicado simultaneamente ao inoculante contendo Rhyzobium sp. e Bradyrhizobium japonicum, respectivamente. O PBBS também não afetou a emergência das plântulas das culturas testadas.A biological fungicide product containing B. subtilis cells (60 g and metabolites (60g was transformed into a wettable powder formulated with, clay (480 g, surfactant (7,92 g and water (2400 ml.The product showed to be similar to the conventional fungicides used in the control of Rhizoctonia solani, Aspergillus sp. and Sclerotinia sclerotiorum in bean seeds. The control of Pyricularia oryzae and Rhinchosporium sativum in rice seeds and Cercospora kikuchii, Phomopsis phaseoli and Fusarium spp. in soybean seeds was also as efficient as the comercial fungicides. For Dreschlera oryzae in rice seeds and Bipolaris sorokiniana, P. oryzae and Alternaria tenuis in wheat seeds, the treatment with the product, althought not as efficient as the chemical treatment, was statistically distinct from the control. The root nodulation of bean and soybean by nitrogen fixing bacteria, was not affected

  20. Potencial de óleos essenciais de plantas medicinais no controle de fitopatógenos

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    M.C.M. FONSECA

    2015-03-01

    Full Text Available Além do valor como recurso terapêutico, plantas medicinais também possuem potencial para serem utilizadas como fonte de princípios ativos contra fitopatógenos. O objetivo deste trabalho foi avaliar o efeito de óleos essenciais das espécies medicinais Baccharis dracunculifolia (alecrim-do-campo, Schinus terebinthifolius (aroeirinha e Porophyllum ruderale (arnica-brasileira sobre o crescimento dos fungos fitopatogênicos Fusarium oxysporum f. sp. phaseoli (Fop, F. solani f. sp. phaseoli (Fsp, Sclerotinia sclerotiorum (Ss, S. minor (Sm, Rhizoctonia solani (Rs, Sclerotium rolfsii (Sr e Macrophomina phaseolina (Mp. Avaliou-se em placas de Petri o crescimento radial desses fungos em meio batata-dextrose-ágar (BDA com cinco concentrações (0, 250, 500, 1000 e 3000 mg L-1 dos óleos essenciais. Discos de micélio (5 mm de diâmetro de cada fungo em crescimento foram transferidos para placas de Petri que foram mantidas a 23°C no escuro por 48 horas. O óleo essencial de alecrim-do-campo foi o mais eficiente na redução do crescimento micelial de todos os fungos, com inibição completa quando se utilizou a concentração de 3000 mg L-1. A redução de crescimento variou de 29% (Fs a 80% (Rs a 250 mg L-1 do óleo essencial de alecrim-do-campo; a 500 mg L-1, variou de 29% (Fs a 98% (Sr; e a 1000 mg L-1, de 41% (Fs a 100% (Sr. A redução do crescimento dos fungos pelo óleo de aroeirinha na concentração de 3000 mg L-1 variou de 27% (Fsp a 74% (Rs. Nessa concentração, o óleo de arnica-brasileira reduziu o crecimento micelial de Ss em 72%, o de Rs em 80% e o de Mp em 82%, sem efeitos significativos sobre o crescimento micelial de Fsp e Fop. Conclui-se que os óleos essenciais de alecrim-do-campo, aroeirinha e arnica-brasileira possuem potencial para o controle dos fungos fitopatogênicos estudados, com destaque para o óleo de alecrim-do-campo.

  1. Yersinia enterocolitica infection and tcaA-dependent killing of Caenorhabditis elegans.

    Science.gov (United States)

    Spanier, Britta; Starke, Mandy; Higel, Fabian; Scherer, Siegfried; Fuchs, Thilo M

    2010-09-01

    Caenorhabditis elegans is a validated model to study bacterial pathogenicity. We report that Yersinia enterocolitica strains W22703 (biovar 2, serovar O:9) and WA314 (biovar 1B, serovar O:8) kill C. elegans when feeding on the pathogens for at least 15 min before transfer to the feeding strain Escherichia coli OP50. The killing by Yersinia enterocolitica requires viable bacteria and, in contrast to that by Yersinia pestis and Yersinia pseudotuberculosis strains, is biofilm independent. The deletion of tcaA encoding an insecticidal toxin resulted in an OP50-like life span of C. elegans, indicating an essential role of TcaA in the nematocidal activity of Y. enterocolitica. TcaA alone is not sufficient for nematocidal activity because E. coli DH5alpha overexpressing TcaA did not result in a reduced C. elegans life span. Spatial-temporal analysis of C. elegans infected with green fluorescent protein-labeled Y. enterocolitica strains showed that Y. enterocolitica colonizes the nematode intestine, leading to an extreme expansion of the intestinal lumen. By low-dose infection with W22703 or DH5alpha followed by transfer to E. coli OP50, proliferation of Y. enterocolitica, but not E. coli, in the intestinal lumen of the nematode was observed. The titer of W22703 cells within the worm increased to over 10(6) per worm 4 days after infection while a significantly lower number of a tcaA knockout mutant was recovered. A strong expression of tcaA was observed during the first 5 days of infection. Y. enterocolitica WA314 (biovar 1B, serovar O:8) mutant strains lacking the yadA, inv, yopE, and irp1 genes known to be important for virulence in mammals were not attenuated or only slightly attenuated in their toxicity toward the nematode, suggesting that these factors do not play a significant role in the colonization and persistence of this pathogen in nematodes. In summary, this study supports the hypothesis that C. elegans is a natural host and nutrient source of Y. enterocolitica.

  2. MLVA Genotyping Characteristics of Human Brucella melitensis Isolated from Ulanqab of Inner Mongolia, China

    Science.gov (United States)

    Liu, Zhi-Guo; Di, Dong-Dong; Wang, Miao; Liu, Ri-Hong; Zhao, Hong-Yan; Piao, Dong-Ri; Tian, Guo-Zhong; Fan, Wei-Xing; Jiang, Hai; Cui, Bu-Yun; Xia, Xian-Zhu

    2017-01-01

    Brucellosis is a serious public health problem in Ulanqab, which is a region located in the middle of the Inner Mongolia Autonomous Region adjacent to Shanxi and Hebei provinces. The disease is prevalent in both the latter provinces and Ulanqab with the highest prevalence of brucellosis occurring in Inner Mongolia. The MLVA-16 scheme is a genotyping tool for assessing genetic diversity and relationships among isolates. Moreover, this genotyping tool can also be applied to epidemiological trace-back investigations. This study reports the occurrence of at least two B. melitensis biovars (1 and 3) in Ulanqab, encompassing 22 and 94 isolates, respectively. B. melitensis biovar 3 was the predominant biovar in the area examined. Panel 1 (MLVA-8) identified three genotypes (42, 63, and 114), with genotype 42 (n = 101) representing 87% of the tested strains. MLVA-11 identified eight genotypes (116, 111, 297, 291, and 342–345) from 116 of the analyzed isolates. All of these isolates were identified as belonging to the East Mediterranean group. Genotype 116 (n = 94) was the predominant genotype and represented 81% of the isolates. The isolates pertaining to this genotype were distributed throughout most of Ulanqab and neighboring regions. The MLVA-16 scheme showed the presence of 69 genotypes, with 46 genotypes being represented by single isolates. This analysis revealed that Ulanqab brucellosis cases had epidemiologically unrelated and sporadic characteristics. The remaining 23 genotypes were shared (between a total of 70 isolates) with each genotype being represented by two to eight isolates. These data indicate that these cases were epidemiologically related. MLVA genotyping confirmed the occurrence of a multipoint outbreak epidemic and intrafamilial brucellosis. Extensive genotype-sharing events were observed among isolates from different regions of Ulanqab and from other provinces of China. These findings suggest either a lack of control of animal movement between

  3. Molecular typing of isolates obtained from aborted foetuses in Brucella-free Holstein dairy cattle herd after immunisation with Brucella abortus RB51 vaccine in Egypt.

    Science.gov (United States)

    Wareth, Gamal; Melzer, Falk; Böttcher, Denny; El-Diasty, Mohamed; El-Beskawy, Mohamed; Rasheed, Nesma; Schmoock, Gernot; Roesler, Uwe; Sprague, Lisa D; Neubauer, Heinrich

    2016-12-01

    Bovine brucellosis is endemic in Egypt in spite of application of surveillance and control measures. An increase of abortions was reported in a Holstein dairy cattle herd with 600 animals in Damietta governorate in Egypt after immunisation with Brucella (B.) abortus RB51 vaccine. Twenty one (10.6%) of 197 vaccinated cows aborted after 3 months. All aborted cows had been tested seronegative for brucellosis in the past 3 years. B. abortus was isolated from four foetuses. Conventional biochemical and bacteriological identification and polymerase chain reaction (PCR) confirmed two B. abortus biovar (bv.) 1 smooth and two B. abortus rough strains. None of the B. abortus isolates were identified as RB51. Genotyping analysis by multiple locus of variable number tandem repeats analysis based on 16 markers (MLVA-16) revealed two different profiles with low genetic diversity. B. abortus bv1 was introduced in the herd and caused abortions.

  4. Laminosioptes cysticola and Gallibacterium anatis infections in a lymphoma diseased chicken hen with a cystic right oviduct

    Directory of Open Access Journals (Sweden)

    E. Soriano-Vargas,

    2010-07-01

    Full Text Available SummaryA domestic hen showing infraorbital swelling was presented for a routine classroom demonstration of avian diagnostics. At necropsy, tiny whitish caseo-calcareous nodules were found in the subcutaneous tissues of the carcass, produced by the subcutaneous fowl mite, Laminosioptes cysticola. Gallibacterium anatis biovar haemolytica was isolated from the infraorbital sinus, it containing a caseous exudate. During necropsy, a conspicuous cyst was found in the abdominal cavity. Microscopic examination of the internal lining of the cyst revealed a single cuboidal to columnar, ciliated epithelium, leading to a diagnosis of oviductal cyst. Also, the microscopic examination of the heart, lung, liver and kidney reveal a multifocal infiltration of lymphoma cells. It appears the first caseof simultaneous presentation of these conditions from a single chicken. Key words: Laminosioptes cysticola, Gallibacterium anatis, oviductal cyst, neoplasia, poultry.

  5. SEROLOGICAL DIAGNOSIS OF MODERN CHOLERA USING LIPOSOMAL ENTEROTOXIC DIAGNOSTICUM IN COMPLEMENT FIXATION TEST

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    I. V. Savelyeva

    2013-01-01

    Full Text Available Abstract. The possibility of serological diagnosis of cholera using cholera enterotoxic diagnostics kit in complement fixation test to detect anti-enterotoxic antibodies in sera of patients with cholera caused by hybrid variants of the El Tor biovar has been demonstrated. In patients with mild course of cholera anti-enterotoxic antibodies were detected in titres 1:50 and 1:200 in paired sera obtained on the 7th and 14th days of disease, respectively (fourfold titre increase. In patients with the course of medium severity 32-fold titre increase was recorded from the titre 1:100 in serum obtained on the fifth day of disease till the titre 1:3200 — on the twelfth day of disease. Antibodies titers reached 1:1600 and 1:800 were revealed in two medium course patients (adult and infant of 10 months on the sixth day of disease.

  6. How Should Staphylococcal Food Poisoning Outbreaks Be Characterized?

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    Sylviane Dragacci

    2010-08-01

    Full Text Available Staphylococcal food poisoning is one of the most common food-borne diseases and results from the ingestion of staphylococcal enterotoxins (SEs preformed in food by enterotoxigenic strains of Staphylococcus aureus. To date, more than 20 SEs have been described: SEA to SElV. All SEs have superantigenic activity whereas only a few have been proved to be emetic, representing a potential hazard for consumers. Characterization of staphylococcal food poisoning outbreaks (SFPOs has considerably progressed compared to 80 years ago, when staphylococci were simply enumerated and only five enterotoxins were known for qualitative detection. Today, SFPOs can be characterized by a number of approaches, such as the identification of S. aureus biovars, PCR and RT-PCR methods to identify the se genes involved, immunodetection of specific SEs, and absolute quantification by mass spectrometry. An integrated gene-to-protein approach for characterizing staphylococcal food poisoning is advocated.

  7. A forgotten disease in a returning traveler from Thailand.

    Science.gov (United States)

    Depypere, M; Verhaegen, J; Derdelinckx, I; Meersseman, W

    2013-01-01

    Cutaneous diphteria is a forgotten disease. We must consider this in our differential diagnosis, not only when a patient presents with a cutaneous ulcer and has travelled to tropical areas, but also in patients who subsist in low socio-economic conditions, especially in homeless people and people with a history of alcohol or drug abuse. Vigilance for this forgotten disease is warranted because most physicians in developed countries have never seen one case. In an era of increasing globalisation, we might see more cases in the future. We report a case of a foot infection with a non toxigenic C. diptheriae biovar gravis in a 16 year old girl, who has travelled to Thailand.

  8. High Incidence of Respiratory Involvement in a Cluster of Brucella suis-Infected Workers from a Pork Processing Plant in Argentina.

    Science.gov (United States)

    Wallach, J C; García, J L; Cardinali, P S; Seijo, A P; Benchetrit, A G; Echazarreta, S E; Garro, S L; Deodato, B; Baldi, P C

    2016-12-29

    Epidemiological and clinical aspects of Brucella suis infection in 17 workers from a pork processing plant in Argentina occurring between January 2014 and July 2015 are presented. All patients reported working 9 h daily without adequate personal protection garment. Blood cultures were positive for Brucella spp. in 14 of the 17 patients (82.3%). All isolates were identified as B. suis biovar 1. Although fever, sweats, asthenia, myalgia and hepatic involvement were the most frequent clinical manifestations, an unusually high incidence of respiratory involvement was found. From 13 patients in which chest radiography was performed, four (30%) had radiological abnormalities, including lobar pneumonia in two cases (one with pleural effusion) and interstitial involvement in other two. The high frequency of respiratory involvement in our series makes necessary to consider brucellosis in the differential diagnosis of respiratory diseases in pork processing plant employees.

  9. Identificação de progênies de tomateiro resistentes à murcha-bacteriana

    OpenAIRE

    Silveira,Elineide B.; Andréa M.A. Gomes; Ferraz,Edinardo; Maranhão,Elizabeth A. A.; Rosa L.R. Mariano

    1999-01-01

    Uma amostra de 660 plantas de uma população F6 de tomateiro, obtida pelo cruzamento das cultivares CL5915-93 (moderadamente resistente) e IPA-6 (suscetível) foi avaliada para resistência a Ralstonia solanacearum em condições de campo (28 ± 4ºC e UR 70 ± 5,5%), em março de 1996 na UFRPE. Plantas com 20 dias foram inoculadas com a biovar III do patógeno pela deposição de 5 ml de uma suspensão (5x10(8) UFC/ml) na base de cada planta, duas horas antes do transplantio para canteiros no campo. As a...

  10. Identificação de progênies de tomateiro resistentes à murcha-bacteriana Identification of tomato progenies for resistance to bacterial wilt

    OpenAIRE

    Silveira,Elineide B.; Andréa M.A. Gomes; Edinardo Ferraz; Maranhão,Elizabeth A. A.; Rosa L.R. Mariano

    1999-01-01

    Uma amostra de 660 plantas de uma população F6 de tomateiro, obtida pelo cruzamento das cultivares CL5915-93 (moderadamente resistente) e IPA-6 (suscetível) foi avaliada para resistência a Ralstonia solanacearum em condições de campo (28 ± 4ºC e UR 70 ± 5,5%), em março de 1996 na UFRPE. Plantas com 20 dias foram inoculadas com a biovar III do patógeno pela deposição de 5 ml de uma suspensão (5x10(8) UFC/ml) na base de cada planta, duas horas antes do transplantio para canteiros no campo. As a...

  11. Diphtheria outbreak in Maranhão, Brazil: microbiological, clinical and epidemiological aspects.

    Science.gov (United States)

    Santos, L S; Sant'anna, L O; Ramos, J N; Ladeira, E M; Stavracakis-Peixoto, R; Borges, L L G; Santos, C S; Napoleão, F; Camello, T C F; Pereira, G A; Hirata, R; Vieira, V V; Cosme, L M S S; Sabbadini, P S; Mattos-Guaraldi, A L

    2015-03-01

    We describe microbiological, clinical and epidemiological aspects of a diphtheria outbreak that occurred in Maranhão, Brazil. The majority of the 27 confirmed cases occurred in partially (n = 16) or completely (n = 10) immunized children (n = 26). Clinical signs and characteristic symptoms of diphtheria such as cervical lymphadenopathy and pseudomembrane formation were absent in 48% and 7% of the cases, respectively. Complications such as paralysis of lower limbs were observed. Three cases resulted in death, two of them in completely immunized children. Microbiological analysis identified the isolates as Corynebacterium diphtheriae biovar intermedius with a predominant PFGE type. Most of them were toxigenic and some showed a decrease in penicillin G susceptibility. In conclusion, diphtheria remains endemic in Brazil. Health professionals need to be aware of the possibility of atypical cases of C. diphtheriae infection, including pharyngitis without pseudomembrane formation.

  12. T4-related bacteriophage LIMEstone isolates for the control of soft rot on potato caused by 'Dickeya solani'.

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    Evelien M Adriaenssens

    Full Text Available The bacterium 'Dickeya solani', an aggressive biovar 3 variant of Dickeya dianthicola, causes rotting and blackleg in potato. To control this pathogen using bacteriophage therapy, we isolated and characterized two closely related and specific bacteriophages, vB_DsoM_LIMEstone1 and vB_DsoM_LIMEstone2. The LIMEstone phages have a T4-related genome organization and share DNA similarity with Salmonella phage ViI. Microbiological and molecular characterization of the phages deemed them suitable and promising for use in phage therapy. The phages reduced disease incidence and severity on potato tubers in laboratory assays. In addition, in a field trial of potato tubers, when infected with 'Dickeya solani', the experimental phage treatment resulted in a higher yield. These results form the basis for the development of a bacteriophage-based biocontrol of potato plants and tubers as an alternative for the use of antibiotics.

  13. Persistent anthrax as a major driver of wildlife mortality in a tropical rainforest

    Science.gov (United States)

    Hoffmann, Constanze; Zimmermann, Fee; Biek, Roman; Kuehl, Hjalmar; Nowak, Kathrin; Mundry, Roger; Agbor, Anthony; Angedakin, Samuel; Arandjelovic, Mimi; Blankenburg, Anja; Brazolla, Gregory; Corogenes, Katherine; Couacy-Hymann, Emmanuel; Deschner, Tobias; Dieguez, Paula; Dierks, Karsten; Düx, Ariane; Dupke, Susann; Eshuis, Henk; Formenty, Pierre; Yuh, Yisa Ginath; Goedmakers, Annemarie; Gogarten, Jan F.; Granjon, Anne-Céline; McGraw, Scott; Grunow, Roland; Hart, John; Jones, Sorrel; Junker, Jessica; Kiang, John; Langergraber, Kevin; Lapuente, Juan; Lee, Kevin; Leendertz, Siv Aina; Léguillon, Floraine; Leinert, Vera; Löhrich, Therese; Marrocoli, Sergio; Mätz-Rensing, Kerstin; Meier, Amelia; Merkel, Kevin; Metzger, Sonja; Murai, Mizuki; Niedorf, Svenja; de Nys, Hélène; Sachse, Andreas; van Schijndel, Joost; Thiesen, Ulla; Ton, Els; Wu, Doris; Wieler, Lothar H.; Boesch, Christophe; Klee, Silke R.; Wittig, Roman M.; Calvignac-Spencer, Sébastien; Leendertz, Fabian H.

    2017-08-01

    Anthrax is a globally important animal disease and zoonosis. Despite this, our current knowledge of anthrax ecology is largely limited to arid ecosystems, where outbreaks are most commonly reported. Here we show that the dynamics of an anthrax-causing agent, Bacillus cereus biovar anthracis, in a tropical rainforest have severe consequences for local wildlife communities. Using data and samples collected over three decades, we show that rainforest anthrax is a persistent and widespread cause of death for a broad range of mammalian hosts. We predict that this pathogen will accelerate the decline and possibly result in the extirpation of local chimpanzee (Pan troglodytes verus) populations. We present the epidemiology of a cryptic pathogen and show that its presence has important implications for conservation.

  14. Feral swine brucellosis in the United States and prospective genomic techniques for disease epidemiology.

    Science.gov (United States)

    Leiser, Owen P; Corn, Joseph L; Schmit, Brandon S; Keim, Paul S; Foster, Jeffrey T

    2013-09-27

    Brucellosis is a common infection of feral swine throughout the United States. With the recent expansion of feral swine populations across the country, this disease poses an increasing threat to agriculture and hunters. The standard approach to Brucella surveillance in feral swine has been serological testing, which gives an indication of past exposure and is a rapid method of determining populations where Brucella is present. More in-depth analyses require bacterial isolation to determine the Brucella species and biovar involved. Ultimately, for a comprehensive understanding of Brucella epizootiology in feral swine, incorporation of genotyping assays has become essential. Fortunately, the past decade has given rise to an array of genetic tools for assessing Brucella transmission and dispersal. This review aims to synthesize what is known about brucellosis in feral swine and will cover prospective genomic techniques that may be utilized to develop more complete understanding of the disease and its transmission history. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Tips and tricks for the assembly of a Corynebacterium pseudotuberculosis genome using a semiconductor sequencer

    DEFF Research Database (Denmark)

    Ramos, Rommel Thiago Jucá; Carneiro, Adriana Ribeiro; Soares, Siomar de Castro;

    2013-01-01

    New sequencing platforms have enabled rapid decoding of complete prokaryotic genomes at relatively low cost. The Ion Torrent platform is an example of these technologies, characterized by lower coverage, generating challenges for the genome assembly. One particular problem is the lack of genomes...... data obtained compared with traditional quality filter approaches. Data preprocessing prior to the de novo assembly enabled the use of known methodologies in the next-generation sequencing data assembly. Moreover, manual curation was proved to be essential for ensuring a quality assembly, which...... that enable reference-based assembly, such as the one used in the present study, Corynebacterium pseudotuberculosis biovar equi, which causes high economic losses in the US equine industry. The quality treatment strategy incorporated into the assembly pipeline enabled a 16-fold greater use of the sequencing...

  16. Seroprevalence of Brucella spp. in Cattle, Molecular Characterization in Milk, and the Analysis of Associated Risk Factors with Seroprevalence in Humans, Egypt.

    Science.gov (United States)

    El-Diasty, Mohamed M; Ahmed, Heba A; Sayour, Ashraf E; El Hofy, Fatma I; Tahoun, Asmaa B M B; Shafik, Saleh M

    2016-12-01

    The objective of the present study was to estimate the seroprevalence of Brucella spp. in humans and cattle at Sharkia Governorate, Egypt. In addition, identification of Brucella spp. in milk samples by PCR and culture with the evaluation of the risk factors associated with Brucella spp. seroprevalence in humans were carried out. Overall, the seroprevalence of Brucella antibodies in the examined cattle was 23.8%, while in human participants it was 21%. The examination of 205 milk samples using PCR revealed that 6.3% were positive for B. abortus biovar 1 and the results were confirmed by culture methods. Multivariate logistic regression revealed that consumption of unpasteurized dairy products, occupational contact with animals, and knowledge about the disease are risk factors associated with infection in humans. This study documented the endemic status of brucellosis in Egypt. Hygienic measures and increased awareness about the disease are recommended to minimize the spread of infection from animals to humans.

  17. [INFLUENCE OF FUNGICIDES COMPLEX INOCULUM EKOVITAL ON RHIZOSPHERE MICROBIOCENOSIS, DISEASES RESISTANCE AND SOYBEEN PRODUCTIVITY].

    Science.gov (United States)

    Vozniuk, S V; Tytova, L V; Lyaska, S I; Iutynska, G O

    2015-01-01

    It has been investigated the effect of fungicide with systemic action of Vitavaks 200 FF, Maxim Star 025 FS, Kinto duo and the complex inoculum Ekovital on rhizospheric microbial communities, diseases resistance and soybean productivity of Annushka biovar. The combined use of fungicides and inoculation has contributed to better formation of nodulation apparatus (the number of nodules on the roots was increased in 1.3-2.8 times), resistance increase to soybean pathogens septoriosis and ascochitosis, plant productivity increase on 17.4-32.1% relatively to the variant with Ekovital. The efficiency of the combined treatment of seeds against septoriosis and ascochitosis has become 45.8-64.1% and 82.0-95.1% respectively, in the flowering-early fruiting stage and 38.1-60.6% and 70.3-82.1% respectively, in the loading beans phase.

  18. [CITRULLINUREIDASE GENE DIVERSITY IN THE GENUS FRANCISELLA].

    Science.gov (United States)

    Timofeev, V S; Bakhteeva, I V; Pavlov, V M; Mokrievich, A N

    2015-01-01

    This work describes the results, of the in silico analysis of the genetic diversity of the citrullinureidase gene (ctu) in two species of bacteria of the genus Francisella: tularensis (ssp. tularensis, holarctica, mediasiatica, novicida) and philomiragia. The strains of the Central Asiatic subspecies possessing the citrullinureidase activity differ in the gene ctu from the ssp tularensis Schu by three nucleotide substitutions leading to two insignificant amino acid substitutions in the encoded polypeptide. In the strain F. tularensis of the ssp. holarctica the gene ctu encodes inactive enzyme, which is probably due to amino acid substitutions: 151 Gly --> Asp, 183 Pro --> Leu, 222 Asp --> Asn. Except for the Japan biovar bacteria, in all strains of the Holarctic subspecies there are two stop codons in the gene ctu. The bacteria of the subspecies novicida contain the ctu gene only in the strain 3523, whereas the other strains contain the gene FTN_0827 encoding the C-N hydrolase, which probably provides the citrullinureidase activity.

  19. 河北省首例水貂养殖者布鲁杆菌病病原学及遗传特征分析%Analysis of pathogens and genetic characteristics of the first case of mink breeder infected with brucellosis in Hebei Province

    Institute of Scientific and Technical Information of China (English)

    姜霞; 钱振宇; 王茜; 何宝花; 孙印旗; 刘晓丽

    2015-01-01

    Objective A suspected Brucella strain, isolated from the first case of mink breeder in Hebei Province was identified and genetic characteristics were analyzed.Methods Blood sample of the patient with brucellosis was collected at brucellosis laboratory of Hebei Provincial Center for Disease Control and Prevention;anti-Brucella antibody was tested and Brucella was isolated by two phase culture bottles.Conventional methods were used to identify the isolated strain, the genetic characteristics were analyzed by multiple-locus variable-number tandem-repeat analysis (MLVA).Results Anti-Brucella antibody was tested positive.The isolated strain was identified as Brucella melitensis biovar 1 using the conventional methods.Using Pannel 1, the strain was genotype 42 clustering to the "East Mediterranean" Brucella Melitensis group.It was closely clustered with Brucella melitensis biovar 3, and difference of repeated numbers at variable-number tandem-repeat (VNTR) loci bruce19 was also displayed.Conclusion The case is the first brucellosis case of mink breeder in Hebei Province, the isolated strain from this patient is identified as Brucella melitensis biovar 1 and the genetic characteristics of the strain are closely related to those of Brucella melitensis biovar 3.%目的 对河北省首例水貂养殖者布鲁杆菌病(简称布病)病例病原菌进行鉴定并对其遗传特征进行分析.方法 2013年8月,在河北省疾病预防控制中心布病实验室,对布病患者血液进行布病血清学抗体检测和血培养.对分离菌株应用传统鉴定方法确定布鲁杆菌属与种型,采用多位点可变数目串联重复序列分析方法(MLVA)分析其遗传特征.结果 血清学检测布病试验阳性.分离菌株鉴定为布鲁杆菌羊种1型.MLVA结果显示该菌Panel1基因型为42,属于东地中海组,与羊种3型聚类最近,但在可变数目串联重复序列位点(VNTR)brucel9存在串联重复数目差异.结论 河北省首例水貂养

  20. Determination of reactive oxygen generated from natural medicines and their antibacterial activity$

    Institute of Scientific and Technical Information of China (English)

    Noriko Tajima; Makiko Takasaki; Haruka Fukamachi; Takeshi Igarashi; Yoshijiro Nakajima; Hidetoshi Arakawa

    2016-01-01

    Extracts of 16 natural medicine powders (Galla chinensis, Malloti cortex, Cassiae semen, Sophorae radix, Myricae cortex, Crataegi fructus, Gambir, Mume fructus, Geranii herba, Phellodendri cortex, Coptidis rhizoma, Swertiae herba, and Cinnamomi cortex) were assayed for reactive oxygen concentrations using the per-oxyoxalate chemiluminescent detection system. High luminescence intensity was observed in Galla chinensis, Geranii herba, Malloti cortex, Myricae cortex, and Cinnamomi cortex. Additional experiments identified the reactive oxygen species as hydrogen peroxide. Galla chinensis generated 2.4 ? 10 ? 4 mol/L hydrogen peroxide from a 1 mg/mL solution. In bacterial growth tests, Galla chinensis extract had antibacterial activity against Escherichia coli, Staphylococcus aureus, Bacteroides thetaiotaomicron, Campylobacter sputorum biovar sputorum, Streptococcus salivarius thermophilus, Lactobacillus casei, and Bifidobacterium longum infantis. This antibacterial activity was de-creased by the addition of catalase. It revealed that hydrogen peroxide which Galla chinensis produced participated in antibacterial activity.