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Sample records for citrobacter rodentium genome

  1. Citrobacter rodentium is an unstable pathogen showing evidence of significant genomic flux.

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    Nicola K Petty

    2011-04-01

    Full Text Available Citrobacter rodentium is a natural mouse pathogen that causes attaching and effacing (A/E lesions. It shares a common virulence strategy with the clinically significant human A/E pathogens enteropathogenic E. coli (EPEC and enterohaemorrhagic E. coli (EHEC and is widely used to model this route of pathogenesis. We previously reported the complete genome sequence of C. rodentium ICC168, where we found that the genome displayed many characteristics of a newly evolved pathogen. In this study, through PFGE, sequencing of isolates showing variation, whole genome transcriptome analysis and examination of the mobile genetic elements, we found that, consistent with our previous hypothesis, the genome of C. rodentium is unstable as a result of repeat-mediated, large-scale genome recombination and because of active transposition of mobile genetic elements such as the prophages. We sequenced an additional C. rodentium strain, EX-33, to reveal that the reference strain ICC168 is representative of the species and that most of the inactivating mutations were common to both isolates and likely to have occurred early on in the evolution of this pathogen. We draw parallels with the evolution of other bacterial pathogens and conclude that C. rodentium is a recently evolved pathogen that may have emerged alongside the development of inbred mice as a model for human disease.

  2. Citrobacter rodentium: infection, inflammation and the microbiota.

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    Collins, James W; Keeney, Kristie M; Crepin, Valerie F; Rathinam, Vijay A K; Fitzgerald, Katherine A; Finlay, B Brett; Frankel, Gad

    2014-09-01

    Citrobacter rodentium is a mucosal pathogen of mice that shares several pathogenic mechanisms with enteropathogenic Escherichia coli (EPEC) and enterohaemorrhagic E. coli (EHEC), which are two clinically important human gastrointestinal pathogens. Thus, C. rodentium has long been used as a model to understand the molecular basis of EPEC and EHEC infection in vivo. In this Review, we discuss recent studies in which C. rodentium has been used to study mucosal immunology, including the deregulation of intestinal inflammatory responses during bacteria-induced colitis and the role of the intestinal microbiota in mediating resistance to colonization by enteric pathogens. These insights should help to elucidate the roles of mucosal inflammatory responses and the microbiota in the virulence of enteric pathogens.

  3. In Vivo Bioluminescence Imaging of the Murine Pathogen Citrobacter rodentium

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    Wiles, Siouxsie; Pickard, Karen M.; Peng, Katian; MacDonald, Thomas T.; Frankel, Gad

    2006-01-01

    Citrobacter rodentium is a natural mouse pathogen related to enteropathogenic and enterohemorrhagic Escherichia coli. We have previously utilized bioluminescence imaging (BLI) to determine the in vivo colonization dynamics of C. rodentium. However, due to the oxygen requirement of the bioluminescence system and the colonic localization of C. rodentium, in vivo localization studies were performed using harvested organs. Here, we report the detection of bioluminescent C. rodentium and commensal...

  4. Citrobacter rodentium mouse model of bacterial infection.

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    Crepin, Valerie F; Collins, James W; Habibzay, Maryam; Frankel, Gad

    2016-10-01

    Infection of mice with Citrobacter rodentium is a robust model to study bacterial pathogenesis, mucosal immunology, the health benefits of probiotics and the role of the microbiota during infection. C. rodentium was first isolated by Barthold from an outbreak of mouse diarrhea in Yale University in 1972 and was 'rediscovered' by Falkow and Schauer in 1993. Since then the use of the model has proliferated, and it is now the gold standard for studying virulence of the closely related human pathogens enteropathogenic and enterohemorrhagic Escherichia coli (EPEC and EHEC, respectively). Here we provide a detailed protocol for various applications of the model, including bacterial growth, site-directed mutagenesis, mouse inoculation (from cultured cells and after cohabitation), monitoring of bacterial colonization, tissue extraction and analysis, immune responses, probiotic treatment and microbiota analysis. The main protocol, from mouse infection to clearance and analysis of tissues and host responses, takes ∼5 weeks to complete. PMID:27606775

  5. Genome-wide analysis of the Pho regulon in a pstCA mutant of Citrobacter rodentium.

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    Catherine Cheng

    Full Text Available The phosphate-specific transport operon, pstSCAB-phoU, of Gram-negative bacteria is an essential part of the Pho regulon. Its key roles are to encode a high-affinity inorganic phosphate transport system and to prevent activation of PhoB in phosphate-rich environments. In general, mutations in pstSCAB-phoU lead to the constitutive expression of the Pho regulon. Previously, we constructed a pstCA deletion mutant of Citrobacter rodentium and found it to be attenuated for virulence in mice, its natural host. This attenuation was dependent on PhoB or PhoB-regulated gene(s because a phoB mutation restored virulence for mice to the pstCA mutant. To investigate how downstream genes may contribute to the virulence of C. rodentium, we used microarray analysis to investigate global gene expression of C. rodentium strain ICC169 and its isogenic pstCA mutant when grown in phosphate-rich medium. Overall 323 genes of the pstCA mutant were differentially expressed by at least 1.5-fold compared to the wild-type C. rodentium. Of these 145 were up-regulated and 178 were down-regulated. Differentially expressed genes included some involved in phosphate homoeostasis, cellular metabolism and protein metabolism. A large number of genes involved in stress responses and of unknown function were also differentially expressed, as were some virulence-associated genes. Up-regulated virulence-associated genes in the pstCA mutant included that for DegP, a serine protease, which appeared to be directly regulated by PhoB. Down-regulated genes included those for the production of the urease, flagella, NleG8 (a type III-secreted protein and the tad focus (which encodes type IVb pili in Yersinia enterocolitica. Infection studies using C57/BL6 mice showed that DegP and NleG8 play a role in bacterial virulence. Overall, our study provides evidence that Pho is a global regulator of gene expression in C. rodentium and indicates the presence of at least two previously unrecognized

  6. Virulence factors enhance Citrobacter rodentium expansion through aerobic respiration.

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    Lopez, Christopher A; Miller, Brittany M; Rivera-Chávez, Fabian; Velazquez, Eric M; Byndloss, Mariana X; Chávez-Arroyo, Alfredo; Lokken, Kristen L; Tsolis, Renée M; Winter, Sebastian E; Bäumler, Andreas J

    2016-09-16

    Citrobacter rodentium uses a type III secretion system (T3SS) to induce colonic crypt hyperplasia in mice, thereby gaining an edge during its competition with the gut microbiota through an unknown mechanism. Here, we show that by triggering colonic crypt hyperplasia, the C. rodentium T3SS induced an excessive expansion of undifferentiated Ki67-positive epithelial cells, which increased oxygenation of the mucosal surface and drove an aerobic C. rodentium expansion in the colon. Treatment of mice with the γ-secretase inhibitor dibenzazepine to diminish Notch-driven colonic crypt hyperplasia curtailed the fitness advantage conferred by aerobic respiration during C. rodentium infection. We conclude that C. rodentium uses its T3SS to induce histopathological lesions that generate an intestinal microenvironment in which growth of the pathogen is fueled by aerobic respiration. PMID:27634526

  7. Fermented dairy products modulate Citrobacter rodentium-induced colonic hyperplasia.

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    Collins, James W; Chervaux, Christian; Raymond, Benoit; Derrien, Muriel; Brazeilles, Rémi; Kosta, Artemis; Chambaud, Isabelle; Crepin, Valerie F; Frankel, Gad

    2014-10-01

    We evaluated the protective effects of fermented dairy products (FDPs) in an infection model, using the mouse pathogen Citrobacter rodentium (CR). Treatment of mice with FDP formulas A, B, and C or a control product did not affect CR colonization, organ specificity, or attaching and effacing lesion formation. Fermented dairy product A (FDP-A), but neither the supernatant from FDP-A nor β-irradiated (IR) FDP-A, caused a significant reduction in colonic crypt hyperplasia and CR-associated pathology. Profiling the gut microbiota revealed that IR-FDP-A promoted higher levels of phylotypes belonging to Alcaligenaceae and a decrease in Lachnospiraceae (Ruminococcus) during CR infection. Conversely, FDP-A prevented a decrease in Ruminococcus and increased Turicibacteraceae (Turicibacter). Importantly, loss of Ruminococcus and Turicibacter has been associated with susceptibility to dextran sodium sulfate-induced colitis. Our results demonstrate that viable bacteria in FDP-A reduced CR-induced colonic crypt hyperplasia and prevented the loss of key bacterial genera that may contribute to disease pathology.

  8. Long-term selenium deficiency increases the pathogenicity of a Citrobacter rodentium infection in mice

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    Citrobacter rodentium is a mouse pathogen that causes infectious colitis and shares characteristics with human enteropathogenic (EPEC) and enterohemorrhagic (EHEC) Escherichia coli, including the ability to cause attaching and effacing lesions in the colon, and serves as a useful model to study the ...

  9. Hypervirulent- host-associated Citrobacter rodentium cells have poor acid tolerance

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    Enhanced virulence or infectivity after passage through a mammalian host has been reported for a number of enteric food-borne pathogens. Citrobacter rodentium is a mouse pathogen that mimics many aspects of enterohemorrhagic E. coli infection of humans and serves as a useful model for studying viru...

  10. Citrobacter rodentium-induced colitis: A robust model to study mucosal immune responses in the gut.

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    Koroleva, Ekaterina P; Halperin, Sydney; Gubernatorova, Ekaterina O; Macho-Fernandez, Elise; Spencer, Cody M; Tumanov, Alexei V

    2015-06-01

    Citrobacter rodentium is a natural mouse pathogen which reproducibly infects mice and causes intestinal disease. The C. rodentium model of infection is very useful for investigating host-pathogen immune interactions in the gut, and can also be used to understand the pathogenesis of several important human intestinal disorders, including Crohn's disease, ulcerative colitis, dysbiosis and colon tumorigenesis. Both innate and adaptive immune responses play a critical role in protection against C. rodentium. Here, we summarize the role of immune components in protection against C. rodentium and describe techniques for the analysis of innate and adaptive mucosal immune responses, including setting up the infection, analysis of colonic hyperplasia and bacterial dissemination, evaluation of antibody responses, and purification and analysis of intestinal epithelial and lymphoid cells.

  11. Development of a real-time PCR assay for quantification of Citrobacter rodentium.

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    Sagaidak, Sofia; Taibi, Amel; Wen, Bijun; Comelli, Elena M

    2016-07-01

    Molecular tools to quantify Citrobacter rodentium are not available. We developed a quantitative PCR assay targeting the espB gene. This assay is specific, has a linearity range of about 6.7×10(1) to 6.7×10(6)cells/PCR reaction (92% efficiency) and a detection limit of about 10(4)cells/g wet feces.

  12. The Serine Protease Autotransporter Pic Modulates Citrobacter rodentium Pathogenesis and Its Innate Recognition by the Host.

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    Bhullar, Kirandeep; Zarepour, Maryam; Yu, Hongbing; Yang, Hong; Croxen, Matthew; Stahl, Martin; Finlay, B Brett; Turvey, Stuart E; Vallance, Bruce A

    2015-07-01

    Bacterial pathogens produce a number of autotransporters that possess diverse functions. These include the family of serine protease autotransporters of Enterobacteriaceae (SPATEs) produced by enteric pathogens such as Shigella flexneri and enteroaggregative Escherichia coli. Of these SPATEs, one termed "protein involved in colonization," or Pic, has been shown to possess mucinase activity in vitro, but to date, its role in in vivo enteric pathogenesis is unknown. Testing a pic null (ΔpicC) mutant in Citrobacter rodentium, a natural mouse pathogen, found that the C. rodentium ΔpicC strain was impaired in its ability to degrade mucin in vitro compared to the wild type. Upon infection of mice, the ΔpicC mutant exhibited a hypervirulent phenotype with dramatically heavier pathogen burdens found in intestinal crypts. ΔpicC mutant-infected mice suffered greater barrier disruption and more severe colitis and weight loss, necessitating their euthanization between 10 and 14 days postinfection. Notably, the virulence of the ΔpicC mutant was normalized when the picC gene was restored; however, a PicC point mutant causing loss of mucinase activity did not replicate the ΔpicC phenotype. Exploring other aspects of PicC function, the ΔpicC mutant was found to aggregate to higher levels in vivo than wild-type C. rodentium. Moreover, unlike the wild type, the C. rodentium ΔpicC mutant had a red, dry, and rough (RDAR) morphology in vitro and showed increased activation of the innate receptor Toll-like receptor 2 (TLR2). Interestingly, the C. rodentium ΔpicC mutant caused a degree of pathology similar to that of wild-type C. rodentium when infecting TLR2-deficient mice, showing that despite its mucinase activity, PicC's major role in vivo may be to limit C. rodentium's stimulation of the host's innate immune system.

  13. Evolutionary adaptation of an AraC-like regulatory protein in Citrobacter rodentium and Escherichia species.

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    Tan, Aimee; Petty, Nicola K; Hocking, Dianna; Bennett-Wood, Vicki; Wakefield, Matthew; Praszkier, Judyta; Tauschek, Marija; Yang, Ji; Robins-Browne, Roy

    2015-04-01

    The evolution of pathogenic bacteria is a multifaceted and complex process, which is strongly influenced by the horizontal acquisition of genetic elements and their subsequent expression in their new hosts. A well-studied example is the RegA regulon of the enteric pathogen Citrobacter rodentium. The RegA regulatory protein is a member of the AraC/XylS superfamily, which coordinates the expression of a gene repertoire that is necessary for full pathogenicity of this murine pathogen. Upon stimulation by an exogenous, gut-associated signal, namely, bicarbonate ions, RegA activates the expression of a series of genes, including virulence factors, such as autotransporters, fimbriae, a dispersin-like protein, and the grlRA operon on the locus of enterocyte effacement pathogenicity island. Interestingly, the genes encoding RegA homologues are distributed across the genus Escherichia, encompassing pathogenic and nonpathogenic subtypes. In this study, we carried out a series of bioinformatic, transcriptional, and functional analyses of the RegA regulons of these bacteria. Our results demonstrated that regA has been horizontally transferred to Escherichia spp. and C. rodentium. Comparative studies of two RegA homologues, namely, those from C. rodentium and E. coli SMS-3-5, a multiresistant environmental strain of E. coli, showed that the two regulators acted similarly in vitro but differed in terms of their abilities to activate the virulence of C. rodentium in vivo, which evidently was due to their differential activation of grlRA. Our data indicate that RegA from C. rodentium has strain-specific adaptations that facilitate infection of its murine host. These findings shed new light on the development of virulence by C. rodentium and on the evolution of virulence-regulatory genes of bacterial pathogens in general.

  14. The CpxRA two-component system is essential for Citrobacter rodentium virulence.

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    Thomassin, Jenny-Lee; Giannakopoulou, Natalia; Zhu, Lei; Gross, Jeremy; Salmon, Kristiana; Leclerc, Jean-Mathieu; Daigle, France; Le Moual, Hervé; Gruenheid, Samantha

    2015-05-01

    Citrobacter rodentium is a murine intestinal pathogen used as a model for the foodborne human pathogens enterohemorrhagic Escherichia coli and enteropathogenic E. coli. During infection, these pathogens use two-component signal transduction systems to detect and adapt to changing environmental conditions. In E. coli, the CpxRA two-component signal transduction system responds to envelope stress by modulating the expression of a myriad of genes. Quantitative real-time PCR showed that cpxRA was expressed in the colon of C57BL/6J mice infected with C. rodentium. To determine whether CpxRA plays a role during C. rodentium infection, a cpxRA deletion strain was generated and found to have a colonization defect during infection. This defect was independent of an altered growth rate or a defective type III secretion system, and single-copy chromosomal complementation of cpxRA restored virulence. The C. rodentium strains were then tested in C3H/HeJ mice, a lethal intestinal infection model. Mice infected with the ΔcpxRA strain survived infection, whereas mice infected with the wild-type or complemented strains succumbed to infection. Furthermore, we found that the cpxRA expression level was higher during early infection than at a later time point. Taken together, these data demonstrate that the CpxRA two-component signal transduction system is essential for the in vivo virulence of C. rodentium. In addition, these data suggest that fine-tuned cpxRA expression is important for infection. This is the first study that identifies a C. rodentium two-component transduction system required for pathogenesis. This study further indicates that CpxRA is an interesting target for therapeutics against enteric pathogens.

  15. Tir Triggers Expression of CXCL1 in Enterocytes and Neutrophil Recruitment during Citrobacter rodentium Infection.

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    Crepin, Valerie F; Habibzay, Maryam; Glegola-Madejska, Izabela; Guenot, Marianne; Collins, James W; Frankel, Gad

    2015-09-01

    The hallmarks of enteropathogenic Escherichia coli (EPEC) infection are formation of attaching and effacing (A/E) lesions on mucosal surfaces and actin-rich pedestals on cultured cells, both of which are dependent on the type III secretion system effector Tir. Following translocation into cultured cells and clustering by intimin, Tir Y474 is phosphorylated, leading to recruitment of Nck, activation of N-WASP, and actin polymerization via the Arp2/3 complex. A secondary, weak, actin polymerization pathway is triggered via an NPY motif (Y454). Importantly, Y454 and Y474 play no role in A/E lesion formation on mucosal surfaces following infection with the EPEC-like mouse pathogen Citrobacter rodentium. In this study, we investigated the roles of Tir segments located upstream of Y451 and downstream of Y471 in C. rodentium colonization and A/E lesion formation. We also tested the role that Tir residues Y451 and Y471 play in host immune responses to C. rodentium infection. We found that deletion of amino acids 382 to 462 or 478 to 547 had no impact on the ability of Tir to mediate A/E lesion formation, although deletion of amino acids 478 to 547 affected Tir translocation. Examination of enterocytes isolated from infected mice revealed that a C. rodentium strain expressing Tir_Y451A/Y471A recruited significantly fewer neutrophils to the colon and triggered less colonic hyperplasia on day 14 postinfection than the wild-type strain. Consistently, enterocytes isolated from mice infected with C. rodentium expressing Tir_Y451A/Y471A expressed significantly less CXCL1. These result show that Tir-induced actin remodeling plays a direct role in modulation of immune responses to C. rodentium infection.

  16. Dietary Chitosan Supplementation Increases Microbial Diversity and Attenuates the Severity of Citrobacter rodentium Infection in Mice

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    Guiping Guan

    2016-01-01

    Full Text Available C57BL/6 mice were tested in order to investigate the effects of dietary chitosan (COS supplements on intestinal microflora and resistance to Citrobacter rodentium infection. The findings reveal that, after consuming a 300 mg/kg COS diet for 14 days, microflora became more diverse as a result of the supplement. Mice receiving COS exhibited an increase in the percentage of Bacteroidetes phylum and a decrease in the percentage of Firmicutes phylum. After Citrobacter rodentium infection, the histopathology scores indicated that COS feeding resulted in less severe colitis. IL-6 and TNF-α were significantly lower in colon from COS-feeding mice than those in the control group. Furthermore, mice in COS group were also found to experience inhibited activation of nuclear factor-kappa B (NF-κB in the colonic tissue. Overall, the findings revealed that adding 300 mg/kg COS to the diet changed the composition of the intestinal microflora of mice, resulting in suppressed NF-κB activation and less production of TNF-α and IL-6; and these changes led to better control of inflammation and resolution of infection with C. rodentium.

  17. Dietary Chitosan Supplementation Increases Microbial Diversity and Attenuates the Severity of Citrobacter rodentium Infection in Mice

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    Wang, Hongbing; Xiong, Xia; Tan, Bie; Al-Dhabi, Naif Abdullah; Fang, Jun

    2016-01-01

    C57BL/6 mice were tested in order to investigate the effects of dietary chitosan (COS) supplements on intestinal microflora and resistance to Citrobacter rodentium infection. The findings reveal that, after consuming a 300 mg/kg COS diet for 14 days, microflora became more diverse as a result of the supplement. Mice receiving COS exhibited an increase in the percentage of Bacteroidetes phylum and a decrease in the percentage of Firmicutes phylum. After Citrobacter rodentium infection, the histopathology scores indicated that COS feeding resulted in less severe colitis. IL-6 and TNF-α were significantly lower in colon from COS-feeding mice than those in the control group. Furthermore, mice in COS group were also found to experience inhibited activation of nuclear factor-kappa B (NF-κB) in the colonic tissue. Overall, the findings revealed that adding 300 mg/kg COS to the diet changed the composition of the intestinal microflora of mice, resulting in suppressed NF-κB activation and less production of TNF-α and IL-6; and these changes led to better control of inflammation and resolution of infection with C. rodentium. PMID:27761062

  18. The cell surface receptor Slamf6 modulates innate immune responses during Citrobacter rodentium-induced colitis.

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    van Driel, Boaz; Wang, Guoxing; Liao, Gongxian; Halibozek, Peter J; Keszei, Marton; O'Keeffe, Michael S; Bhan, Atul K; Wang, Ninghai; Terhorst, Cox

    2015-09-01

    The homophilic cell surface receptors CD150 (Slamf1) and CD352 (Slamf6) are known to modulate adaptive immune responses. Although the Th17 response was enhanced in Slamf6(-/-) C57BL/6 mice upon oral infection with Citrobacter rodentium, the pathologic consequences are indistinguishable from an infection of wild-type C57BL/6 mice. Using a reporter-based binding assay, we show that Slamf6 can engage structures on the outer cell membrane of several Gram(-) bacteria. Therefore, we examined whether Slamf6, like Slamf1, is also involved in innate responses to bacteria and regulates peripheral inflammation by assessing the outcome of C. rodentium infections in Rag(-/-) mice. Surprisingly, the pathology and immune responses in the lamina propria of C. rodentium-infected Slamf6(-/-) Rag(-/-) mice were markedly reduced as compared with those of Rag(-/-) mice. Infiltration of inflammatory phagocytes into the lamina propria was consistently lower in Slamf6(-/-) Rag(-/-) mice than in Rag(-/-) animals. Concomitant with the reduced systemic translocation of the bacteria was an enhanced production of IL-22, suggesting that Slamf6 suppresses a mucosal protective program. Furthermore, administering a mAb (330) that inhibits bacterial interactions with Slamf6 to Rag(-/-) mice ameliorated the infection compared with a control antibody. We conclude that Slamf6-mediated interactions of colonic innate immune cells with specific Gram(-) bacteria reduce mucosal protection and enhance inflammation, contributing to lethal colitis that is caused by C. rodentium infections in Rag(-/-) mice.

  19. The pathogenicity of an enteric Citrobacter rodentium infection is enhanced by deficiencies in the antioxidants selenium and vitamin E

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    Citrobacter rodentium is a mouse pathogen that shares many characteristics with human enteropathogenic (EPEC) and enterohemorrhagic (EHEC) Escherichia coli, the causative agents for human disease, and serves as a useful model to study immunity to these organisms. In this study, the effect of a doub...

  20. Selective enrichment of commensal gut bacteria protects against Citrobacter rodentium-induced colitis.

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    Vong, Linda; Pinnell, Lee J; Määttänen, Pekka; Yeung, C William; Lurz, Eberhard; Sherman, Philip M

    2015-08-01

    The intestinal microbiota plays a key role in shaping the host immune system. Perturbation of gut microbial composition, termed dysbiosis, is associated with an increased susceptibility to intestinal pathogens and is a hallmark of a number of inflammatory, metabolic, and infectious diseases. The prospect of mining the commensal gut microbiota for bacterial strains that can impact immune function represents an attractive strategy to counteract dysbiosis and resulting disease. In this study, we show that selective enrichment of commensal gut lactobacilli protects against the murine pathogen Citrobacter rodentium, a well-characterized model of enteropathogenic and enterohemorrhagic Escherichia coli infection. The lactobacilli-enriched bacterial culture prevented the expansion of Gammaproteobacteria and Actinobacteria and was associated with improved indexes of epithelial barrier function (dextran flux), transmissible crypt hyperplasia, and tissue inflammatory cytokine levels. Moreover, cultivation of gut bacteria from Citrobacter rodentium-infected mice reveals the differential capacity of bacterial subsets to mobilize neutrophil oxidative burst and initiate the formation of weblike neutrophil extracellular traps. Our findings highlight the beneficial effects of a lactobacilli-enriched commensal gut microenvironment and, in the context of an intestinal barrier breach, the ability of neutrophils to immobilize both commensal and pathogenic bacteria.

  1. Investigation of Host and Pathogen Contributions to Infectious Colitis Using the Citrobacter rodentium Mouse Model of Infection.

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    Bosman, Else S; Chan, Justin M; Bhullar, Kirandeep; Vallance, Bruce A

    2016-01-01

    Citrobacter rodentium is used as a model organism to study enteric bacterial infections in mice. Infection occurs via the oral-fecal route and results in the pathogen forming attaching and effacing lesions on infected epithelial cells. Moreover, infection leads to a subsequent host-mediated form of colitis. C. rodentium infection is thus an excellent model to study infectious colitis in vivo, while the ability to genetically manipulate C. rodentium virulence genes provides the opportunity to develop clear insights into the pathogenesis of this and related infectious microbes. This chapter outlines the basic techniques involved in setting up a C. rodentium infection in mice and several different methodologies to assess the severity of the infection.

  2. Influence of NleH effector expression, host genetics, and inflammation on Citrobacter rodentium colonization of mice.

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    Feuerbacher, Leigh Ann; Hardwidge, Philip R

    2014-05-01

    The Escherichia coli NleH1 and NleH2 virulence proteins differentially regulate host transcription of innate immunity genes. The mouse pathogen Citrobacter rodentium encodes one NleH protein, which functions equivalently to E. coli NleH1. We examined the impact of host genetics and intestinal inflammation on the contribution of NleH to C. rodentium colonization of mice differing in LPS responsiveness. NleH expression was detrimental to C. rodentium in C57BL/10ScNJ mice, which do not mount LPS-induced inflammatory responses. This phenotype was reversed if inflammation was induced by chemical means. C. rodentium that expressed both E. coli NleH1 and NleH2 was hypervirulent in C3H/HeJ mice.

  3. Rac2-deficiency leads to exacerbated and protracted colitis in response to Citrobacter rodentium infection.

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    Fattouh, Ramzi; Guo, Cong-Hui; Lam, Grace Y; Gareau, Melanie G; Ngan, Bo-Yee; Glogauer, Michael; Muise, Aleixo M; Brumell, John H

    2013-01-01

    Recent genetic-based studies have implicated a number of immune-related genes in the pathogenesis of inflammatory bowel disease (IBD). Our recent genetic studies showed that RAC2 is associated with human IBD; however, its role in disease pathogenesis is unclear. Given Rac2's importance in various fundamental immune cell processes, we investigated whether a defect in Rac2 may impair host immune responses in the intestine and promote disease in the context of an infection-based (Citrobacter rodentium) model of colitis. In response to infection, Rac2(-/-) mice showed i) worsened clinical symptoms (days 13-18), ii) increased crypt hyperplasia at days 11 and 22 (a time when crypt hyperplasia was largely resolved in wild-type mice; WT), and iii) marked mononuclear cell infiltration characterized by higher numbers of T (CD3(+)) cells (day 22), compared to WT-infected mice. Moreover, splenocytes harvested from infected Rac2(-/-) mice and stimulated in vitro with C. rodentium lysate produced considerably higher levels of interferon-γ and interleukin-17A. The augmented responses observed in Rac2(-/-) mice did not appear to stem from Rac2's role in NADPH oxidase-driven reactive oxygen species production as no differences in crypt hyperplasia, nor inflammation, were observed in infected NOX2(-/-) mice compared to WT. Collectively, our findings demonstrate that Rac2(-/-) mice develop more severe disease when subjected to a C. rodentium-induced model of infectious colitis, and suggest that impaired Rac2 function may promote the development of IBD in humans. PMID:23613889

  4. Rac2-deficiency leads to exacerbated and protracted colitis in response to Citrobacter rodentium infection.

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    Ramzi Fattouh

    Full Text Available Recent genetic-based studies have implicated a number of immune-related genes in the pathogenesis of inflammatory bowel disease (IBD. Our recent genetic studies showed that RAC2 is associated with human IBD; however, its role in disease pathogenesis is unclear. Given Rac2's importance in various fundamental immune cell processes, we investigated whether a defect in Rac2 may impair host immune responses in the intestine and promote disease in the context of an infection-based (Citrobacter rodentium model of colitis. In response to infection, Rac2(-/- mice showed i worsened clinical symptoms (days 13-18, ii increased crypt hyperplasia at days 11 and 22 (a time when crypt hyperplasia was largely resolved in wild-type mice; WT, and iii marked mononuclear cell infiltration characterized by higher numbers of T (CD3(+ cells (day 22, compared to WT-infected mice. Moreover, splenocytes harvested from infected Rac2(-/- mice and stimulated in vitro with C. rodentium lysate produced considerably higher levels of interferon-γ and interleukin-17A. The augmented responses observed in Rac2(-/- mice did not appear to stem from Rac2's role in NADPH oxidase-driven reactive oxygen species production as no differences in crypt hyperplasia, nor inflammation, were observed in infected NOX2(-/- mice compared to WT. Collectively, our findings demonstrate that Rac2(-/- mice develop more severe disease when subjected to a C. rodentium-induced model of infectious colitis, and suggest that impaired Rac2 function may promote the development of IBD in humans.

  5. Dynamic changes in mucus thickness and ion secretion during Citrobacter rodentium infection and clearance.

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    Jenny K Gustafsson

    Full Text Available Citrobacter rodentium is an attaching and effacing pathogen used as a murine model for enteropathogenic Escherichia coli. The mucus layers are a complex matrix of molecules, and mucus swelling, hydration and permeability are affected by many factors, including ion composition. Here, we used the C. rodentium model to investigate mucus dynamics during infection. By measuring the mucus layer thickness in tissue explants during infection, we demonstrated that the thickness changes dynamically during the course of infection and that its thickest stage coincides with the start of a decrease of bacterial density at day 14 after infection. Although quantitative PCR analysis demonstrated that mucin mRNA increases during early infection, the increased mucus layer thickness late in infection was not explained by increased mRNA levels. Proteomic analysis of mucus did not demonstrate the appearance of additional mucins, but revealed an increased number of proteins involved in defense responses. Ussing chamber-based electrical measurements demonstrated that ion secretion was dynamically altered during the infection phases. Furthermore, the bicarbonate ion channel Bestrophin-2 mRNA nominally increased, whereas the Cftr mRNA decreased during the late infection clearance phase. Microscopy of Muc2 immunostained tissues suggested that the inner striated mucus layer present in the healthy colon was scarce during the time point of most severe infection (10 days post infection, but then expanded, albeit with a less structured appearance, during the expulsion phase. Together with previously published literature, the data implies a model for clearance where a change in secretion allows reformation of the mucus layer, displacing the pathogen to the outer mucus layer, where it is then outcompeted by the returning commensal flora. In conclusion, mucus and ion secretion are dynamically altered during the C. rodentium infection cycle.

  6. Psidium guajava leaf extract prevents intestinal colonization of Citrobacter rodentium in the mouse model

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    Pooja Gupta

    2015-01-01

    Full Text Available Diarrheal diseases are the second highest cause of mortality of children under 5 years worldwide. There is a continuous search for developing a cost-effective treatment for diarrhea as the present ones are facing challenges. Medicinal plants can be explored further as an alternative treatment for diarrhea. Psidium guajava leaves have been used as an antidiarrheal globally. Citrobacter rodentium, a common mouse pathogen, is known to mimic the pathogenecity of enteropathogenic and enterohemorrhagic E. coli. It can thus present an effective model to study infectious diarrhea. In the present study, the P. guajava leaf extract was tested for its efficacy in treating infectious diarrhea using a C. rodentium mouse model. The mice in the test group (treated with P. guajava leaf extract showed quicker clearance of infection as compared with the control group. The bacterial load in the fecal sample of the mice in the test group was high on Day 4 as compared with that in the control group, suggesting a flush out of the bacteria. In the test group, 6/7 (85.71% mice showed clearance of infection by Day 19. The control group continued to show infection till Day 29. P. guajava leaf extract thus has the potential for use in the treatment of infectious diarrhea.

  7. A balanced IL-1β activity is required for host response to Citrobacter rodentium infection.

    Directory of Open Access Journals (Sweden)

    Misagh Alipour

    Full Text Available Microbial sensing plays essential roles in the innate immune response to pathogens. In particular, NLRP3 forms a multiprotein inflammasome complex responsible for the maturation of interleukin (IL-1β. Our aim was to delineate the role of the NLRP3 inflammasome in macrophages, and the contribution of IL-1β to the host defense against Citrobacter rodentium acute infection in mice. Nlrp3(-/- and background C57BL/6 (WT mice were infected by orogastric gavage, received IL-1β (0.5 µg/mouse; ip on 0, 2, and 4 days post-infection (DPI, and assessed on 6 and 10 DPI. Infected Nlrp3(-/- mice developed severe colitis; IL-1β treatments reduced colonization, abrogated dissemination of bacteria to mesenteric lymph nodes, and protected epithelial integrity of infected Nlrp3(-/- mice. In contrast, IL-1β treatments of WT mice had an opposite effect with increased penetration of bacteria and barrier disruption. Microscopy showed reduced damage in Nlrp3(-/- mice, and increased severity of disease in WT mice with IL-1β treatments, in particular on 10 DPI. Secretion of some pro-inflammatory plasma cytokines was dissipated in Nlrp3(-/- compared to WT mice. IL-1β treatments elevated macrophage infiltration into infected crypts in Nlrp3(-/- mice, suggesting that IL-1β may improve macrophage function, as exogenous administration of IL-1β increased phagocytosis of C. rodentium by peritoneal Nlrp3(-/- macrophages in vitro. As well, the exogenous administration of IL-1β to WT peritoneal macrophages damaged the epithelial barrier of C. rodentium-infected polarized CMT-93 cells. Treatment of Nlrp3(-/- mice with IL-1β seems to confer protection against C. rodentium infection by reducing colonization, protecting epithelial integrity, and improving macrophage activity, while extraneous IL-1β appeared to be detrimental to WT mice. Together, these findings highlight the importance of balanced cytokine responses as IL-1β improved bacterial clearance in Nlrp3(-/- mice

  8. Polarizing the T helper 17 response in Citrobacter rodentium infection via expression of resistin-like molecule α.

    Science.gov (United States)

    Chen, Gang; Chan, Alexander J; Chung, Josiah I; Jang, Jessica C; Osborne, Lisa C; Nair, Meera G

    2014-01-01

    Citrobacter rodentium infection is a murine model of pathogenic Escherichia coli infection that allows investigation of the cellular and molecular mechanisms involved in host-protective immunity and bacterial-induced intestinal inflammation. We recently demonstrated that following C. rodentium infection, the absence of Resistin-Like Molecule (RELM) α resulted in attenuated Th17 cell responses and reduced intestinal inflammation with minimal effects on bacterial clearance. In this addendum, we investigated the cytokine modulatory effects of RELMα and RELMα expression in the intestinal mucosa following C. rodentium infection. We show that in addition to promoting Th17 cytokine responses, RELMα inhibits Th2 cytokine expression and Th2-cytokine effector macrophage responses in the C. rodentium-infected colons. Second, utilizing reporter C. rodentium, we examined RELMα expression and macrophage recruitment at the host pathogen interface. We observed infection-induced macrophage infiltration and RELMα expression by intestinal epithelial cells. The influence of infection-induced RELMα on macrophage recruitment in the intestine is discussed.

  9. Role of class 1 serine protease autotransporter in the pathogenesis of Citrobacter rodentium colitis.

    Science.gov (United States)

    Vijayakumar, Vidhya; Santiago, Araceli; Smith, Rachel; Smith, Mark; Robins-Browne, Roy M; Nataro, James P; Ruiz-Perez, Fernando

    2014-06-01

    A growing family of virulence factors called serine protease autotransporters of Enterobacteriaceae (SPATEs) are secreted by Shigella, Salmonella, and Escherichia coli pathotypes. SPATEs are subdivided into class 1 and class 2 based on structural features and phylogenetics. Class 1 SPATEs induce cytopathic effects in numerous epithelial cell lines, and several have been shown to cleave the cytoskeletal protein spectrin in vitro. However, to date the in vivo role of class 1 SPATEs in enteric pathogenesis is unknown. Citrobacter rodentium, a natural mouse pathogen, has recently been shown to harbor class 1 and class 2 SPATEs. To better understand the contribution of class 1 SPATEs in enteric infection, we constructed a class 1 SPATE null mutant (Δcrc1) in C. rodentium. Upon infection of C57BL/6 mice, the Δcrc1 mutant exhibited a hypervirulent, hyperinflammatory phenotype compared with its parent, accompanied by greater weight loss and a trend toward increased mortality in young mice; the effect was reversed when the crc1 gene was restored. Using flow cytometry, we observed increased infiltration of T cells, B cells, and neutrophils into the lamina propria of the distal colon in mice fed the Δcrc1 mutant, starting as early as 5 days after infection. No significant difference in epithelial cytotoxicity was observed. Reverse transcription-PCR (RT-PCR) analysis of distal colonic tissue on day 10 postinfection showed significant increases in mRNA encoding cytokines interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), gamma interferon (IFN-γ), IL-1β, and inducible nitric oxide synthase (iNOS) but not in mRNA encoding IL-17, IL-4, or IL-10 in the Δcrc1 mutant-infected mice. Our data suggest a previously unsuspected role for class 1 SPATEs in enteric infection.

  10. Dysbiosis caused by vitamin D receptor deficiency confers colonization resistance to Citrobacter rodentium through modulation of innate lymphoid cells.

    Science.gov (United States)

    Chen, J; Waddell, A; Lin, Y-D; Cantorna, M T

    2015-05-01

    Vitamin D receptor (VDR) knockout (KO) mice had fewer Citrobacter rodentium in the feces than wild-type (WT) mice and the kinetics of clearance was faster in VDR KO than WT mice. VDR KO mice had more interleukin-22 (IL-22)-producing innate lymphoid cells (ILCs) and more antibacterial peptides than WT mice. The increased ILCs in the VDR KO mice was a cell-autonomous effect of VDR deficiency on ILC frequencies. Bone marrow (BM) transplantation from VDR KO mice into WT resulted in higher ILCs and colonization resistance of the WT mice. Disruption of the gut microbiota using antibiotics in VDR KO mice reversed colonization resistance to C. rodentium infection. Confirming the role of the microbiota in the colonization resistance of VDR KO mice, transfer of the VDR KO microbiota to WT germ-free mice resulted in colonization resistance. Once colonization resistance was overcome, VDR KO mice had increased susceptibility to C. rodentium. VDR expression is a regulator of ILC frequencies, IL-22, dysbiosis, and C. rodentium susceptibility.

  11. Understanding the host-adapted state of Citrobacter rodentium by transcriptomic analysis.

    Science.gov (United States)

    Smith, Allen D; Yan, Xianghe; Chen, Celine; Dawson, Harry D; Bhagwat, Arvind A

    2016-05-01

    Citrobacter rodentium (Cr) is a mouse pathogen that mimics many aspects of enteropathogenic Escherichia coli infections including producing attaching and effacing (A/E) lesions. Host-adapted (HA) Cr cells that are shed at the peak of infection have been reported to be hyper-infective. The exact mechanism underlying this phenomenon has remained elusive since the pathogen loses its HA 'status' immediately upon subculturing in laboratory media. We sequenced the entire transcriptome of Cr directly from the feces of infected mice and analyzed the gene expression pattern. We observed that the entire transcriptional machinery as well as several transcriptional regulators to be differentially expressed when compared with the transcriptome of cells grown on laboratory media. Major adhesion and effector genes, tir and eae, were highly expressed in HA along with many genes located on all five loci of enterocyte effacement regions (LEE 1-5). Notable absent among the HA expressed genes were 19 fimbrial operons and non-fimbrial adhesions and several non-LEE encoded effectors. These results demonstrate that host-adapted Cr has a unique transcriptome that is associated with increased host transmission.

  12. Immunological mechanisms involved in probiotic-mediated protection against Citrobacter rodentium-induced colitis.

    Science.gov (United States)

    Jiang, Y; Yang, G; Meng, F; Yang, W; Hu, J; Ye, L; Shi, C; Wang, C

    2016-06-01

    Inflammatory bowel disease is a group of chronic, incurable inflammatory disorders of the gastrointestinal tract that cause severe diarrhoea, intestinal inflammation, pain, fatigue and weight loss. In this study, we first developed a model of Citrobacter rodentium-induced colitis and then evaluated the protective effects of selected probiotics on inflammation. The results showed that administration of a combination of probiotics including Lactobacillus rhamnosus ATCC 53103, Lactobacillus acidophilus ATCC 4356 and Lactobacillus plantarum A significantly increased the production of CD11c(+) dendritic cells in the spleen (3.62% vs phosphate buffered saline (PBS)-treated control, P<0.01) and mesenteric lymph nodes (MLNs). In addition, the presence of probiotics significantly up-regulated the development of CD4(+)/CD25(+)/Foxp3(+) regulatory T cells in MLNs by approximately 2.07% compared to the effect observed in the PBS-treated control (P<0.01) and down-regulated the expression of inflammatory cytokines, including interleukin-17, tumour necrosis factor-α and interferon-γ, by 0.11, 0.11 and 0.15%, respectively, compared to the effect observed in the PBS-treated control (P<0.01).These effects conferred protection against colitis, as shown by histopathological analyses.

  13. IL-23-mediated mononuclear phagocyte crosstalk protects mice from Citrobacter rodentium-induced colon immunopathology.

    Science.gov (United States)

    Aychek, Tegest; Mildner, Alexander; Yona, Simon; Kim, Ki-Wook; Lampl, Nardy; Reich-Zeliger, Shlomit; Boon, Louis; Yogev, Nir; Waisman, Ari; Cua, Daniel J; Jung, Steffen

    2015-01-01

    Gut homeostasis and mucosal immune defense rely on the differential contributions of dendritic cells (DC) and macrophages. Here we show that colonic CX3CR1(+) mononuclear phagocytes are critical inducers of the innate response to Citrobacter rodentium infection. Specifically, the absence of IL-23 expression in macrophages or CD11b(+) DC results in the impairment of IL-22 production and in acute lethality. Highlighting immunopathology as a death cause, infected animals are rescued by the neutralization of IL-12 or IFNγ. Moreover, mice are also protected when the CD103(+) CD11b(-) DC compartment is rendered deficient for IL-12 production. We show that IL-12 production by colonic CD103(+) CD11b(-) DC is repressed by IL-23. Collectively, in addition to its role in inducing IL-22 production, macrophage-derived or CD103(-) CD11b(+) DC-derived IL-23 is required to negatively control the otherwise deleterious production of IL-12 by CD103(+) CD11b(-) DC. Impairment of this critical mononuclear phagocyte crosstalk results in the generation of IFNγ-producing former TH17 cells and fatal immunopathology.

  14. Immunological mechanisms involved in probiotic-mediated protection against Citrobacter rodentium-induced colitis.

    Science.gov (United States)

    Jiang, Y; Yang, G; Meng, F; Yang, W; Hu, J; Ye, L; Shi, C; Wang, C

    2016-06-01

    Inflammatory bowel disease is a group of chronic, incurable inflammatory disorders of the gastrointestinal tract that cause severe diarrhoea, intestinal inflammation, pain, fatigue and weight loss. In this study, we first developed a model of Citrobacter rodentium-induced colitis and then evaluated the protective effects of selected probiotics on inflammation. The results showed that administration of a combination of probiotics including Lactobacillus rhamnosus ATCC 53103, Lactobacillus acidophilus ATCC 4356 and Lactobacillus plantarum A significantly increased the production of CD11c(+) dendritic cells in the spleen (3.62% vs phosphate buffered saline (PBS)-treated control, Pprobiotics significantly up-regulated the development of CD4(+)/CD25(+)/Foxp3(+) regulatory T cells in MLNs by approximately 2.07% compared to the effect observed in the PBS-treated control (P<0.01) and down-regulated the expression of inflammatory cytokines, including interleukin-17, tumour necrosis factor-α and interferon-γ, by 0.11, 0.11 and 0.15%, respectively, compared to the effect observed in the PBS-treated control (P<0.01).These effects conferred protection against colitis, as shown by histopathological analyses. PMID:26925601

  15. Modulation of Inducible Nitric Oxide Synthase Expression by the Attaching and Effacing Bacterial Pathogen Citrobacter rodentium in Infected Mice

    Science.gov (United States)

    Vallance, Bruce A.; Deng, Wanyin; De Grado, Myriam; Chan, Crystal; Jacobson, Kevan; Finlay, B. Brett

    2002-01-01

    Citrobacter rodentium belongs to the attaching and effacing family of enteric bacterial pathogens that includes both enteropathogenic and enterohemorrhagic Escherichia coli. These bacteria infect their hosts by colonizing the intestinal mucosal surface and intimately attaching to underlying epithelial cells. The abilities of these pathogens to exploit the cytoskeleton and signaling pathways of host cells are well documented, but their interactions with the host's antimicrobial defenses, such as inducible nitric oxide synthase (iNOS), are poorly understood. To address this issue, we infected mice with C. rodentium and found that iNOS mRNA expression in the colon significantly increased during infection. Immunostaining identified epithelial cells as the major source for immunoreactive iNOS. Finding that nitric oxide (NO) donors were bacteriostatic for C. rodentium in vitro, we examined whether iNOS expression contributed to host defense by infecting iNOS-deficient mice. Loss of iNOS expression caused a small but significant delay in bacterial clearance without affecting tissue pathology. Finally, immunofluorescence staining was used to determine if iNOS expression was localized to infected cells by staining for the C. rodentium virulence factor, translocated intimin receptor (Tir), as well as iNOS. Interestingly, while more than 85% of uninfected epithelial cells expressed iNOS, fewer than 15% of infected (Tir-positive) cells expressed detectable iNOS. These results demonstrate that both iNOS and intestinal epithelial cells play an active role in host defense during C. rodentium infection. However, the selective expression of iNOS by uninfected but not infected cells suggests that this pathogen has developed mechanisms to locally limit its exposure to host-derived NO. PMID:12379723

  16. CXCL9 contributes to antimicrobial protection of the gut during citrobacter rodentium infection independent of chemokine-receptor signaling.

    Directory of Open Access Journals (Sweden)

    Sarah A Reid-Yu

    2015-02-01

    Full Text Available Chemokines have been shown to be effective bactericidal molecules against a variety of bacteria and fungi in vitro. These direct antimicrobial effects are independent of their chemotactic activities involving immunological receptors. However, the direct biological role that these proteins may play in host defense, particularly against intestinal pathogens, is poorly understood. Here, we show that CXCL9, an ELR- chemokine, exhibits direct antimicrobial activity against Citrobacter rodentium, an attaching/effacing pathogen that infects the gut mucosa. Inhibition of this antimicrobial activity in vivo using anti-CXCL9 antibodies increases host susceptibility to C. rodentium infection with pronounced bacterial penetration into crypts, increased bacterial load, and worsened tissue pathology. Using Rag1(-/- mice and CXCR3(-/- mice, we demonstrate that the role for CXCL9 in protecting the gut mucosa is independent of an adaptive response or its immunological receptor, CXCR3. Finally, we provide evidence that phagocytes function in tandem with NK cells for robust CXCL9 responses to C. rodentium. These findings identify a novel role for the immune cell-derived CXCL9 chemokine in directing a protective antimicrobial response in the intestinal mucosa.

  17. Dietary vitamin D3 deficiency alters intestinal mucosal defense and increases susceptibility to Citrobacter rodentium-induced colitis.

    Science.gov (United States)

    Ryz, Natasha R; Lochner, Arion; Bhullar, Kirandeep; Ma, Caixia; Huang, Tina; Bhinder, Ganive; Bosman, Else; Wu, Xiujuan; Innis, Sheila M; Jacobson, Kevan; Vallance, Bruce A

    2015-11-01

    Vitamin D deficiency affects more that 1 billion people worldwide. Although thought to increase risk of bacterial infections, the importance of vitamin D on host defense against intestinal bacterial pathogens is currently unclear since injection of the active form of vitamin D, 1,25(OH)2D3, increased susceptibility to the enteric bacterial pathogen Citrobacter rodentium by suppressing key immune/inflammatory factors. To further characterize the role of vitamin D during bacteria-induced colitis, we fed weanling mice either vitamin D3-deficient or vitamin D3-sufficient diets for 5 wk and then challenged them with C. rodentium. Vitamin D3-deficient mice lost significantly more body weight, carried higher C. rodentium burdens, and developed worsened histological damage. Vitamin D3-deficient mice also suffered greater bacterial translocation to extra-intestinal tissues, including mesenteric lymph nodes, spleen, and liver. Intestinal tissues of infected vitamin D3-deficient mice displayed increased inflammatory cell infiltrates as well as significantly higher gene transcript levels of inflammatory mediators TNF-α, IL-1β, IL-6, TGF-β, IL-17A, and IL-17F as well as the antimicrobial peptide REG3γ. Notably, these exaggerated inflammatory responses accelerated the loss of commensal microbes and were associated with an impaired ability to detoxify bacterial lipopolysaccharide. Overall, these studies show that dietary-induced vitamin D deficiency exacerbates intestinal inflammatory responses to infection, also impairing host defense.

  18. CXCL9 contributes to antimicrobial protection of the gut during citrobacter rodentium infection independent of chemokine-receptor signaling.

    Science.gov (United States)

    Reid-Yu, Sarah A; Tuinema, Brian R; Small, Cherrie N; Xing, Lydia; Coombes, Brian K

    2015-02-01

    Chemokines have been shown to be effective bactericidal molecules against a variety of bacteria and fungi in vitro. These direct antimicrobial effects are independent of their chemotactic activities involving immunological receptors. However, the direct biological role that these proteins may play in host defense, particularly against intestinal pathogens, is poorly understood. Here, we show that CXCL9, an ELR- chemokine, exhibits direct antimicrobial activity against Citrobacter rodentium, an attaching/effacing pathogen that infects the gut mucosa. Inhibition of this antimicrobial activity in vivo using anti-CXCL9 antibodies increases host susceptibility to C. rodentium infection with pronounced bacterial penetration into crypts, increased bacterial load, and worsened tissue pathology. Using Rag1(-/-) mice and CXCR3(-/-) mice, we demonstrate that the role for CXCL9 in protecting the gut mucosa is independent of an adaptive response or its immunological receptor, CXCR3. Finally, we provide evidence that phagocytes function in tandem with NK cells for robust CXCL9 responses to C. rodentium. These findings identify a novel role for the immune cell-derived CXCL9 chemokine in directing a protective antimicrobial response in the intestinal mucosa.

  19. Interleukin-7 produced by intestinal epithelial cells in response to Citrobacter rodentium infection plays a major role in innate immunity against this pathogen.

    Science.gov (United States)

    Zhang, Wei; Du, Jiang-Yuan; Yu, Qing; Jin, Jun-O

    2015-08-01

    Interleukin-7 (IL-7) engages multiple mechanisms to overcome chronic viral infections, but the role of IL-7 in bacterial infections, especially enteric bacterial infections, remains unclear. Here we characterized the previously unexplored role of IL-7 in the innate immune response to the attaching and effacing bacterium Citrobacter rodentium. C. rodentium infection induced IL-7 production from intestinal epithelial cells (IECs). IL-7 production from IECs in response to C. rodentium was dependent on gamma interferon (IFN-γ)-producing NK1.1(+) cells and IL-12. Treatment with anti-IL-7Rα antibody during C. rodentium infection resulted in a higher bacterial burden, enhanced intestinal damage, and greater weight loss and mortality than observed with the control IgG treatment. IEC-produced IL-7 was only essential for protective immunity against C. rodentium during the first 6 days after infection. An impaired bacterial clearance upon IL-7Rα blockade was associated with a significant decrease in macrophage accumulation and activation in the colon. Moreover, C. rodentium-induced expansion and activation of intestinal CD4(+) lymphoid tissue inducer (LTi) cells was completely abrogated by IL-7Rα blockade. Collectively, these data demonstrate that IL-7 is produced by IECs in response to C. rodentium infection and plays a critical role in the protective immunity against this intestinal attaching and effacing bacterium.

  20. Properdin provides protection from Citrobacter rodentium-induced intestinal inflammation in a C5a/IL-6-dependent manner.

    Science.gov (United States)

    Jain, Umang; Cao, Qi; Thomas, Nikhil A; Woodruff, Trent M; Schwaeble, Wilhelm J; Stover, Cordula M; Stadnyk, Andrew W

    2015-04-01

    Citrobacter rodentium is an attaching and effacing mouse pathogen that models enteropathogenic and enterohemorrhagic Escherichia coli in humans. The complement system is an important innate defense mechanism; however, only scant information is available about the role of complement proteins during enteric infections. In this study, we examined the impact of the lack of properdin, a positive regulator of complement, in C. rodentium-induced colitis. Following infection, properdin knockout (P(KO)) mice had increased diarrhea and exacerbated inflammation combined with defective epithelial cell-derived IL-6 and greater numbers of colonizing bacteria. The defect in the mucosal response was reversed by administering exogenous properdin to P(KO) mice. Then, using in vitro and in vivo approaches, we show that the mechanism behind the exacerbated inflammation of P(KO) mice is due to a failure to increase local C5a levels. We show that C5a directly stimulates IL-6 production from colonic epithelial cells and that inhibiting C5a in infected wild-type mice resulted in defective epithelial IL-6 production and exacerbated inflammation. These outcomes position properdin early in the response to an infectious challenge in the colon, leading to complement activation and C5a, which in turn provides protection through IL-6 expression by the epithelium. Our results unveil a previously unappreciated mechanism of intestinal homeostasis involving complement, C5a, and IL-6 during bacteria-triggered epithelial injury.

  1. R-Spondins Are Expressed by the Intestinal Stroma and are Differentially Regulated during Citrobacter rodentium- and DSS-Induced Colitis in Mice.

    Science.gov (United States)

    Kang, Eugene; Yousefi, Mitra; Gruenheid, Samantha

    2016-01-01

    The R-spondin family of proteins has recently been described as secreted enhancers of β-catenin activation through the canonical Wnt signaling pathway. We previously reported that Rspo2 is a major determinant of susceptibility to Citrobacter rodentium-mediated colitis in mice and recent genome-wide association studies have revealed RSPO3 as a candidate Crohn's disease-specific inflammatory bowel disease susceptibility gene in humans. However, there is little information on the endogenous expression and cellular source of R-spondins in the colon at steady state and during intestinal inflammation. RNA sequencing and qRT-PCR were used to assess the expression of R-spondins at steady state and in two mouse models of colonic inflammation. The cellular source of R-spondins was assessed in specific colonic cell populations isolated by cell sorting. Data mining from publicly available datasets was used to assess the expression of R-spondins in the human colon. At steady state, colonic expression of R-spondins was found to be exclusive to non-epithelial CD45- lamina propria cells, and Rspo3/RSPO3 was the most highly expressed R-spondin in both mouse and human colon. R-spondin expression was found to be highly dynamic and differentially regulated during C. rodentium infection and dextran sodium sulfate (DSS) colitis, with notably high levels of Rspo3 expression during DSS colitis, and high levels of Rspo2 expression during C. rodentium infection, specifically in susceptible mice. Our data are consistent with the hypothesis that in the colon, R-spondins are expressed by subepithelial stromal cells, and that Rspo3/RSPO3 is the family member most implicated in colonic homeostasis. The differential regulation of the R-spondins in different models of intestinal inflammation indicate they respond to specific pathogenic and inflammatory signals that differ in the two models and provides further evidence that this family of proteins plays a key role in linking intestinal

  2. Rac2-Deficiency Leads to Exacerbated and Protracted Colitis in Response to Citrobacter rodentium Infection

    OpenAIRE

    Ramzi Fattouh; Cong-Hui Guo; Lam, Grace Y; Gareau, Melanie G.; Bo-Yee Ngan; Michael Glogauer; Aleixo M Muise; Brumell, John H.

    2013-01-01

    Recent genetic-based studies have implicated a number of immune-related genes in the pathogenesis of inflammatory bowel disease (IBD). Our recent genetic studies showed that RAC2 is associated with human IBD; however, its role in disease pathogenesis is unclear. Given Rac2's importance in various fundamental immune cell processes, we investigated whether a defect in Rac2 may impair host immune responses in the intestine and promote disease in the context of an infection-based (Citrobacter rod...

  3. IL-4 Protects the Mitochondria Against TNFα and IFNγ Induced Insult During Clearance of Infection with Citrobacter rodentium and Escherichia coli.

    Science.gov (United States)

    Maiti, Arpan K; Sharba, Sinan; Navabi, Nazanin; Forsman, Huamei; Fernandez, Harvey R; Lindén, Sara K

    2015-01-01

    Citrobacter rodentium is a murine pathogen that serves as a model for enteropathogenic Escherichia coli. C. rodentium infection reduced the quantity and activity of mitochondrial respiratory complexes I and IV, as well as phosphorylation capacity, mitochondrial transmembrane potential and ATP generation at day 10, 14 and 19 post infection. Cytokine mRNA quantification showed increased levels of IFNγ, TNFα, IL-4, IL-6, and IL-12 during infection. The effects of adding these cytokines, C. rodentium and E. coli were hence elucidated using an in vitro colonic mucosa. Both infection and TNFα, individually and combined with IFNγ, decreased complex I and IV enzyme levels and mitochondrial function. However, IL-4 reversed these effects, and IL-6 protected against loss of complex IV. Both in vivo and in vitro, the dysfunction appeared caused by nitric oxide-generation, and was alleviated by an antioxidant targeting mitochondria. IFNγ -/- mice, containing a similar pathogen burden but higher IL-4 and IL-6, displayed no loss of any of the four complexes. Thus, the cytokine environment appears to be a more important determinant of mitochondrial function than direct actions of the pathogen. As IFNγ and TNFα levels increase during clearance of infection, the concomitant increase in IL-4 and IL-6 protects mitochondrial function.

  4. Draft Genome Sequence of the Type Species of the Genus Citrobacter, Citrobacter freundii MTCC 1658

    OpenAIRE

    Kumar, Shailesh; Kaur, Chandandeep; Kimura, Kazuyuki; Takeo, Masahiro; Raghava, Gajendra Pal Singh; Mayilraj, Shanmugam

    2013-01-01

    We report the 5.0-Mb genome sequence of the type species of the genus Citrobacter, Citrobacter freundii strain MTCC 1658, isolated from canal water. This draft genome sequence of C. freundii strain MTCC 1658T consists of 5,001,265 bp with a G+C content of 51.61%, 4,691 protein-coding genes, 70 tRNAs, and 10 rRNAs.

  5. The in vitro and in vivo effects of constitutive light expression on a bioluminescent strain of the mouse enteropathogen Citrobacter rodentium

    Science.gov (United States)

    Read, Hannah M.; Mills, Grant; Johnson, Sarah; Tsai, Peter; Dalton, James; Barquist, Lars; Print, Cristin G.; Patrick, Wayne M.

    2016-01-01

    Bioluminescent reporter genes, such as those from fireflies and bacteria, let researchers use light production as a non-invasive and non-destructive surrogate measure of microbial numbers in a wide variety of environments. As bioluminescence needs microbial metabolites, tagging microorganisms with luciferases means only live metabolically active cells are detected. Despite the wide use of bioluminescent reporter genes, very little is known about the impact of continuous (also called constitutive) light expression on tagged bacteria. We have previously made a bioluminescent strain of Citrobacter rodentium, a bacterium which infects laboratory mice in a similar way to how enteropathogenic Escherichia coli (EPEC) and enterohaemorrhagic E. coli (EHEC) infect humans. In this study, we compared the growth of the bioluminescent C. rodentium strain ICC180 with its non-bioluminescent parent (strain ICC169) in a wide variety of environments. To understand more about the metabolic burden of expressing light, we also compared the growth profiles of the two strains under approximately 2,000 different conditions. We found that constitutive light expression in ICC180 was near-neutral in almost every non-toxic environment tested. However, we also found that the non-bioluminescent parent strain has a competitive advantage over ICC180 during infection of adult mice, although this was not enough for ICC180 to be completely outcompeted. In conclusion, our data suggest that constitutive light expression is not metabolically costly to C. rodentium and supports the view that bioluminescent versions of microbes can be used as a substitute for their non-bioluminescent parents to study bacterial behaviour in a wide variety of environments. PMID:27366640

  6. The in vitro and in vivo effects of constitutive light expression on a bioluminescent strain of the mouse enteropathogen Citrobacter rodentium.

    Science.gov (United States)

    Read, Hannah M; Mills, Grant; Johnson, Sarah; Tsai, Peter; Dalton, James; Barquist, Lars; Print, Cristin G; Patrick, Wayne M; Wiles, Siouxsie

    2016-01-01

    Bioluminescent reporter genes, such as those from fireflies and bacteria, let researchers use light production as a non-invasive and non-destructive surrogate measure of microbial numbers in a wide variety of environments. As bioluminescence needs microbial metabolites, tagging microorganisms with luciferases means only live metabolically active cells are detected. Despite the wide use of bioluminescent reporter genes, very little is known about the impact of continuous (also called constitutive) light expression on tagged bacteria. We have previously made a bioluminescent strain of Citrobacter rodentium, a bacterium which infects laboratory mice in a similar way to how enteropathogenic Escherichia coli (EPEC) and enterohaemorrhagic E. coli (EHEC) infect humans. In this study, we compared the growth of the bioluminescent C. rodentium strain ICC180 with its non-bioluminescent parent (strain ICC169) in a wide variety of environments. To understand more about the metabolic burden of expressing light, we also compared the growth profiles of the two strains under approximately 2,000 different conditions. We found that constitutive light expression in ICC180 was near-neutral in almost every non-toxic environment tested. However, we also found that the non-bioluminescent parent strain has a competitive advantage over ICC180 during infection of adult mice, although this was not enough for ICC180 to be completely outcompeted. In conclusion, our data suggest that constitutive light expression is not metabolically costly to C. rodentium and supports the view that bioluminescent versions of microbes can be used as a substitute for their non-bioluminescent parents to study bacterial behaviour in a wide variety of environments. PMID:27366640

  7. Transcriptional frameshifting rescues Citrobacter rodentium type VI secretion by the production of two length variants from the prematurely interrupted tssM gene.

    Science.gov (United States)

    Gueguen, Erwan; Wills, Norma M; Atkins, John F; Cascales, Eric

    2014-12-01

    The Type VI secretion system (T6SS) mediates toxin delivery into both eukaryotic and prokaryotic cells. It is composed of a cytoplasmic structure resembling the tail of contractile bacteriophages anchored to the cell envelope through a membrane complex composed of the TssL and TssM inner membrane proteins and of the TssJ outer membrane lipoprotein. The C-terminal domain of TssM is required for its interaction with TssJ, and for the function of the T6SS. In Citrobacter rodentium, the tssM1 gene does not encode the C-terminal domain. However, the stop codon is preceded by a run of 11 consecutive adenosines. In this study, we demonstrate that this poly-A tract is a transcriptional slippery site that induces the incorporation of additional adenosines, leading to frameshifting, and hence the production of two TssM1 variants, including a full-length canonical protein. We show that both forms of TssM1, and the ratio between these two forms, are required for the function of the T6SS in C. rodentium. Finally, we demonstrate that the tssM gene associated with the Yersinia pseudotuberculosis T6SS-3 gene cluster is also subjected to transcriptional frameshifting.

  8. Enteric infection with Citrobacter rodentium induces coagulative liver necrosis and hepatic inflammation prior to peak infection and colonic disease.

    Directory of Open Access Journals (Sweden)

    Arkadiusz R Raczynski

    Full Text Available Acute and chronic forms of inflammation are known to affect liver responses and susceptibility to disease and injury. Furthermore, intestinal microbiota has been shown critical in mediating inflammatory host responses in various animal models. Using C. rodentium, a known enteric bacterial pathogen, we examined liver responses to gastrointestinal infection at various stages of disease pathogenesis. For the first time, to our knowledge, we show distinct liver pathology associated with enteric infection with C. rodentium in C57BL/6 mice, characterized by increased inflammation and hepatitis index scores as well as prominent periportal hepatocellular coagulative necrosis indicative of thrombotic ischemic injury in a subset of animals during the early course of C. rodentium pathogenesis. Histologic changes in the liver correlated with serum elevation of liver transaminases, systemic and liver resident cytokines, as well as signal transduction changes prior to peak bacterial colonization and colonic disease. C. rodentium infection in C57BL/6 mice provides a potentially useful model to study acute liver injury and inflammatory stress under conditions of gastrointestinal infection analogous to enteropathogenic E. coli infection in humans.

  9. Interleukin-1 (IL-1) signaling in intestinal stromal cells controls KC/ CXCL1 secretion, which correlates with recruitment of IL-22- secreting neutrophils at early stages of Citrobacter rodentium infection.

    Science.gov (United States)

    Lee, Yong-Soo; Yang, Hyungjun; Yang, Jin-Young; Kim, Yeji; Lee, Su-Hyun; Kim, Ji Heui; Jang, Yong Ju; Vallance, Bruce A; Kweon, Mi-Na

    2015-08-01

    Attaching and effacing pathogens, including enterohemorrhagic Escherichia coli in humans and Citrobacter rodentium in mice, raise serious public health concerns. Here we demonstrate that interleukin-1 receptor (IL-1R) signaling is indispensable for protection against C. rodentium infection in mice. Four days after infection with C. rodentium, there were significantly fewer neutrophils (CD11b+ Ly6C+ Ly6G+) in the colons of IL-1R−/− mice than in wild-type mice. Levels of mRNA and protein of KC/CXCL1 were also significantly reduced in colon homogenates of infected IL-1R−/− mice relative to wild-type mice. Of note, infiltrated CD11b+ Ly6C+ Ly6G+ neutrophils were the main source of IL-22 secretion after C. rodentium infection. Interestingly, intestinal stromal cells isolated from IL-1R−/− mice secreted lower levels of KC/CXCL1 than stromal cells from wild-type mice during C. rodentium infection. Similar effects were found when mouse intestinal stromal cells and human nasal polyp stromal cells were treated with IL-1R antagonists (i.e., anakinra) in vitro. These results suggest that IL-1 signaling plays a pivotal role in activating mucosal stromal cells to secrete KC/CXCL1, which is essential for infiltration of IL-22-secreting neutrophils upon bacterial infection.

  10. Genome sequence of Citrobacter sp. strain A1, a dye-degrading bacterium.

    Science.gov (United States)

    Chan, Giek Far; Gan, Han Ming; Rashid, Noor Aini Abdul

    2012-10-01

    Citrobacter sp. strain A1, isolated from a sewage oxidation pond, is a facultative aerobe and mesophilic dye-degrading bacterium. This organism degrades azo dyes efficiently via azo reduction and desulfonation, followed by the successive biotransformation of dye intermediates under an aerobic environment. Here we report the draft genome sequence of Citrobacter sp. A1.

  11. Complete genome sequence of novel carbon monoxide oxidizing bacteria Citrobacter amalonaticus Y19, assembled de novo.

    Science.gov (United States)

    Ainala, Satish Kumar; Seol, Eunhee; Park, Sunghoon

    2015-10-10

    We report here the complete genome sequence of Citrobacter amalonaticus Y19 isolated from an anaerobic digester. PacBio single-molecule real-time (SMRT) sequencing was employed, resulting in a single scaffold of 5.58Mb. The sequence of a mega plasmid of 291Kb size is also presented.

  12. Phylogeny and Comparative Genomics Unveil Independent Diversification Trajectories of qnrB and Genetic Platforms within Particular Citrobacter Species.

    Science.gov (United States)

    Ribeiro, Teresa G; Novais, Ângela; Branquinho, Raquel; Machado, Elisabete; Peixe, Luísa

    2015-10-01

    To gain insights into the diversification trajectories of qnrB genes, a phylogenetic and comparative genomics analysis of these genes and their surrounding genetic sequences was performed. For this purpose, Citrobacter sp. isolates (n = 21) and genome or plasmid sequences (n = 56) available in public databases harboring complete or truncated qnrB genes were analyzed. Citrobacter species identification was performed by phylogenetic analysis of different genotypic markers. The clonal relatedness among isolates, the location of qnrB genes, and the genetic surroundings of qnrB genes were investigated by pulsed-field gel electrophoresis (PFGE), S1-/I-CeuI-PFGE and hybridization, and PCR mapping and sequencing, respectively. Identification of Citrobacter isolates was achieved using leuS and recN gene sequences, and isolates characterized in this study were diverse and harbored chromosomal qnrB genes. Phylogenetic analysis of all known qnrB genes revealed seven main clusters and two branches, with most of them included in two clusters. Specific platforms (comprising pspF and sapA and varying in synteny and/or identity of other genes and intergenic regions) were associated with each one of these qnrB clusters, and the reliable identification of all Citrobacter isolates revealed that each platform evolved in different recognizable (Citrobacter freundii, C. braakii, C. werkmanii, and C. pasteurii) and putatively new species. A high identity was observed between some of the platforms identified in the chromosome of Citrobacter spp. and in different plasmids of Enterobacteriaceae. Our data corroborate Citrobacter as the origin of qnrB and further suggest divergent evolution of closely related qnrB genes/platforms in particular Citrobacter spp., which were delineated using particular genotypic markers.

  13. Genome Sequence of Citrobacter sp. CtB7.12, Isolated from the Gut of the Desert Subterranean Termite Heterotermes aureus

    Science.gov (United States)

    Fontes-Perez, Héctor; Olvera-García, Myrna; Chávez-Martínez, America; Rodriguez-Almeida, Felipe A.; Arzola-Alvarez, Claudio A.

    2015-01-01

    The draft genome of Citrobacter sp. CtB7.12, isolated from termite gut, is presented here. This organism has been reported as a cellulolytic bacterium, which is biotechnologically important because it can be used as a gene donor for the ethanol and biofuel industries. PMID:26543121

  14. Unraveling the dha cluster in Citrobacter werkmanii: comparative genomic analysis of bacterial 1,3-propanediol biosynthesis clusters.

    Science.gov (United States)

    Maervoet, Veerle E T; De Maeseneire, Sofie L; Soetaert, Wim K; De Mey, Marjan

    2014-04-01

    In natural 1,3-propanediol (PDO) producing microorganisms such as Klebsiella pneumoniae, Citrobacter freundii and Clostridium sp., the genes coding for PDO producing enzymes are grouped in a dha cluster. This article describes the dha cluster of a novel candidate for PDO production, Citrobacter werkmanii DSM17579 and compares the cluster to the currently known PDO clusters of Enterobacteriaceae and Clostridiaceae. Moreover, we attribute a putative function to two previously unannotated ORFs, OrfW and OrfY, both in C. freundii and in C. werkmanii: both proteins might form a complex and support the glycerol dehydratase by converting cob(I)alamin to the glycerol dehydratase cofactor coenzyme B12. Unraveling this biosynthesis cluster revealed high homology between the deduced amino acid sequence of the open reading frames of C. werkmanii DSM17579 and those of C. freundii DSM30040 and K. pneumoniae MGH78578, i.e., 96 and 87.5 % identity, respectively. On the other hand, major differences between the clusters have also been discovered. For example, only one dihydroxyacetone kinase (DHAK) is present in the dha cluster of C. werkmanii DSM17579, while two DHAK enzymes are present in the cluster of K. pneumoniae MGH78578 and Clostridium butyricum VPI1718.

  15. Multilocus sequence analysis of the genus Citrobacter and description of Citrobacter pasteurii sp. nov.

    Science.gov (United States)

    Clermont, Dominique; Motreff, Laurence; Passet, Virginie; Fernandez, José-Carlos; Bizet, Chantal; Brisse, Sylvain

    2015-05-01

    Strains originating from various sources and classified as members of the genus Citrobacter within the family Enterobacteriaceae were characterized by sequencing internal portions of genes rpoB, fusA, pyrG and leuS, 16S rRNA gene sequencing, average nucleotide identity (ANI) of genomic sequences and biochemical tests. Phylogenetic analysis based on the four housekeeping genes showed that the 11 species of the genus Citrobacter with validly published names are well demarcated. Strains CIP 55.13(T) and CIP 55.9 formed a distinct branch associated with Citrobacter youngae. The ANI between CIP 55.9 and CIP 55.13(T) was 99.19%, whereas it was 94.75% between CIP 55.13(T) and strain CIP 105016(T) of the species C. youngae, the most closely related species. Biochemical characteristics consolidated the fact that the two isolates represent a separate species, for which the name Citrobacter pasteurii sp. nov. is proposed. The type strain is CIP 55.13(T) ( =DSM 28879(T) =Na 1a(T)).

  16. Endocarditis Due to Citrobacter Freundii

    OpenAIRE

    Reyes, Cesar V.; Folwarkiw, Oksana

    1984-01-01

    The etiologic association of acute bacterial endocarditis with the Citrobacter species has been rare, although it is one of the opportunistic organisms that afflicts the elderly, neonates, the debilitated and immunocompromised. We report a case of endocarditis due to Citrobacter freundii.

  17. A Genomic Island in Salmonella enterica ssp. salamae provides new insights on the genealogy of the locus of enterocyte effacement.

    Directory of Open Access Journals (Sweden)

    P Scott Chandry

    Full Text Available The genomic island encoding the locus of enterocyte effacement (LEE is an important virulence factor of the human pathogenic Escherichia coli. LEE typically encodes a type III secretion system (T3SS and secreted effectors capable of forming attaching and effacing lesions. Although prominent in the pathogenic E. coli such as serotype O157:H7, LEE has also been detected in Citrobacter rodentium, E. albertii, and although not confirmed, it is likely to also be in Shigella boydii. Previous phylogenetic analysis of LEE indicated the genomic island was evolving through stepwise acquisition of various components. This study describes a new LEE region from two strains of Salmonella enterica subspecies salamae serovar Sofia along with a phylogenetic analysis of LEE that provides new insights into the likely evolution of this genomic island. The Salmonella LEE contains 36 of the 41 genes typically observed in LEE within a genomic island of 49, 371 bp that encodes a total of 54 genes. A phylogenetic analysis was performed on the entire T3SS and four T3SS genes (escF, escJ, escN, and escV to elucidate the genealogy of LEE. Phylogenetic analysis inferred that the previously known LEE islands are members of a single lineage distinct from the new Salmonella LEE lineage. The previously known lineage of LEE diverged between islands found in Citrobacter and those in Escherichia and Shigella. Although recombination and horizontal gene transfer are important factors in the genealogy of most genomic islands, the phylogeny of the T3SS of LEE can be interpreted with a bifurcating tree. It seems likely that the LEE island entered the Enterobacteriaceae through horizontal gene transfer as a single unit, rather than as separate subsections, which was then subjected to the forces of both mutational change and recombination.

  18. A Genomic Island in Salmonella enterica ssp. salamae provides new insights on the genealogy of the locus of enterocyte effacement.

    Science.gov (United States)

    Chandry, P Scott; Gladman, Simon; Moore, Sean C; Seemann, Torsten; Crandall, Keith A; Fegan, Narelle

    2012-01-01

    The genomic island encoding the locus of enterocyte effacement (LEE) is an important virulence factor of the human pathogenic Escherichia coli. LEE typically encodes a type III secretion system (T3SS) and secreted effectors capable of forming attaching and effacing lesions. Although prominent in the pathogenic E. coli such as serotype O157:H7, LEE has also been detected in Citrobacter rodentium, E. albertii, and although not confirmed, it is likely to also be in Shigella boydii. Previous phylogenetic analysis of LEE indicated the genomic island was evolving through stepwise acquisition of various components. This study describes a new LEE region from two strains of Salmonella enterica subspecies salamae serovar Sofia along with a phylogenetic analysis of LEE that provides new insights into the likely evolution of this genomic island. The Salmonella LEE contains 36 of the 41 genes typically observed in LEE within a genomic island of 49, 371 bp that encodes a total of 54 genes. A phylogenetic analysis was performed on the entire T3SS and four T3SS genes (escF, escJ, escN, and escV) to elucidate the genealogy of LEE. Phylogenetic analysis inferred that the previously known LEE islands are members of a single lineage distinct from the new Salmonella LEE lineage. The previously known lineage of LEE diverged between islands found in Citrobacter and those in Escherichia and Shigella. Although recombination and horizontal gene transfer are important factors in the genealogy of most genomic islands, the phylogeny of the T3SS of LEE can be interpreted with a bifurcating tree. It seems likely that the LEE island entered the Enterobacteriaceae through horizontal gene transfer as a single unit, rather than as separate subsections, which was then subjected to the forces of both mutational change and recombination.

  19. Citrobacter bitternis sp. nov. isolated from bitterns.

    Science.gov (United States)

    Ko, Kwan Soo; Choi, Ji-Young; Kim, Joo; Park, Myoung Kyu

    2015-06-01

    In this study, we reported two gram-negative bacteria that were isolated from bitterns, designated as SKKU-TP7(T) and SKKU-TP20, representing a novel species of Citrobacter. Based on the 16S rRNA gene sequences, the two strains were found to be closely related and showed the highest pairwise similarity with Citrobacter farmeri CDC 2992-81(T) (97.1-97.3 %) and other Citrobacter species. Cellular fatty acid analysis revealed that the profiles of strains SKKU-TP7(T) and SKKU-TP20 were similar to those of related species of Citrobacter. The major cellular fatty acids were C16:0 (31.5 %), summed feature 3 (C16:1 ω7c, C16:1 ω6c, 19.7 %), summed feature 8 (C18:1 ω7c, C18:1 ω6c, 11.9 %), C17:0 cyclo (10.7 %), and summed feature 2 (C12:0 aldehyde/unknown 10928, 9.5 %). Although the strains could utilize sucrose and raffinose as a carbon source, they did not produce ornithine decarboxylase and urease. The biochemical and genotypic characteristics indicate that strains SKKU-TP7(T) and SKKU-TP20 represent a novel species of Citrobacter, for which the name Citrobacter bitterns sp. nov. is proposed. The type strain is SKKU-TP7(T) (=KCTC 42139(T) = JCM 30009(T)).

  20. Characterization of a virulent bacteriophage LK1 specific for Citrobacter freundii isolated from sewage water.

    Science.gov (United States)

    Chaudhry, Waqas Nasir; Haq, Irshad Ul; Andleeb, Saadia; Qadri, Ishtiaq

    2014-06-01

    Citrobacter freundii is a worldwide emerging nosocomial pathogen with escalating incidence of multidrug resistance. Citrobacter freundii exists in natural environment, especially in health care settings and is difficult to eradicate. Phage therapy is considered as an alternative way of controlling bacterial infections and contaminations. In this study, we have described isolation and characterization of a virulent bacteriophage LK1 capable of specifically infecting Citrobacter freundii. A virulent bacteriophage LK1, specific for Citrobacter freundii was isolated from sewage water sample. TEM showed that phage Lk1 has an icosahedral head 70 nm in diameter and short tail of 17 nm, and can be classified as a member of the Podoviridae family. Restriction analysis indicated that phage LK1 was a dsDNA virus with an approximate genome size of 20-23 kb. Proteomic pattern generated by SDS PAGE using purified LK1 phage particles, revealed three major and six minor protein bands with molecular weight ranging from 25 to 80 kDa. Adsorption rate of LK1 relative to the host bacterium was also determined which showed significant improvement in adsorption with the addition of CaCl2 . In a single step growth experiment, LK1 exhibited a latent period of 24 min and burst size of 801 particle/cell. Moreover, pH and thermal stability of phage LK1 demonstrated a pH range of 5.0-6.0 and phage viability decreased to 0% at 65 °C. When LK1 was used to infect six other clinically isolated pathogenic strains, it showed relatively narrow host range. LK1 was capable of eliciting efficient lysis of Citrobacter freundii, revealing its potential as a non-toxic sanitizer for controlling Citrobacter freundii infection and contamination in both hospital and other public environments.

  1. 21 CFR 866.3125 - Citrobacter spp. serological reagents.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Citrobacter spp. serological reagents. 866.3125... (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3125 Citrobacter spp. serological reagents. (a) Identification. Citrobacter spp. serological reagents are devices...

  2. Pathogenicity of Helicobacter rodentium in A/JCr and SCID mice.

    Science.gov (United States)

    Myles, Matthew H; Livingston, Robert S; Franklin, Craig L

    2004-10-01

    Helicobacter rodentium was first recognized as a potential pathogen when it was isolated, along with Helicobacter bilis, from a colony of scid/Trp53 knockout mice with diarrhea. Clinical disease in these mice was more severe than that previously reported in mice infected with H. bilis alone, thus suggesting that H. rodentium contributed to the pathogenesis of enteritis. The purpose of the study reported here was to address two questions: is H. rodentium pathogenic in mice, and when co-infection with a pathogenic helicobacter occurs, does H. rodentium augment disease? To this end, A/JCr and C.B-17/IcrCrl-scidBr mice were inoculated with H. rodentium and/or H. hepaticus. Twelve weeks after inoculation, mice were euthanized. The cecum and liver were evaluated microscopically for evidence of disease. Cecal interferon-inducible protein 10 (IP-10), macrophage inflammatory protein 1alpha (MIP-1alpha), interleukin 10 (IL-10), and interferon gamma (IFN-gamma) mRNA values were measured as an indicator of mucosal immune response. Hepatic lesions were not identified in mice mono-infected with H. rodentium; likewise, cecal lesion scores were not significantly different from those of uninfected controls. With the exception of an increased IL-10 mRNA value in SCID mice, mean immune-related gene expression in H. rodentium mono-infected and uninfected control mice was not significantly different. In contrast, all mice infected with H. hepaticus developed moderate to severe hepatitis, significant increase in cecal lesion scores, and increased immune-related gene expression. The C.B-17/IcrCrl-scidBr mice co-infected with H. hepaticus and H. rodentium had liquid cecal contents and low terminal body weight. Further, compared with mice infected with H. hepaticus alone, co-infection was associated with significant increases of IL-10, MIP-1alpha, and IP-10 mRNA values in C.B-17/IcrCrl-scidBr and IFN-gamma and MIP-1alpha mRNA values in A/JCr mice. These results suggested that H. rodentium

  3. Optimum management of Citrobacter koseri infection.

    Science.gov (United States)

    Deveci, Aydin; Coban, Ahmet Yilmaz

    2014-09-01

    Low virulent Citrobacter koseri can cause life threatening infections. Neonates and other immunocompromised patients are particularly susceptible to infection from C. koseri. Any infection due to C. koseri mandates antimicrobial therapy based on the sensitivity of the pathogen microorganism. Various types of antibiotics, including aminoglycosides carbapenems, cephalosporins, chloramphenicol and quinolones, are used for the treatment of C. koseri infections. The rational choice of antimicrobial therapy for Citrobacter infections is a challenge for clinicians because there is a sustained increase in antibacterial resistance. We reviewed antimicrobial agents used for C. koseri infections in this review.

  4. Citrobacter koseri meningitis: another freediving risk?

    Science.gov (United States)

    Pollara, Gabriele; Savy, Lloyd; Cropley, Ian; Hopkins, Susan

    2011-01-01

    We present a rare case of meningitis caused by Citrobacter koseri in an immunocompetent adult who had recently been freediving. Middle ear pressure changes from this recreational activity, and the subsequent inflammatory response, are likely to have provided this environmental organism access to the central nervous system, and thus the ability to cause clinically significant infection. PMID:20933000

  5. In vitro susceptibility of Citrobacter species to various antimicrobial agents.

    OpenAIRE

    Samonis, G.; Ho, D H; Gooch, G F; Rolston, K V; Bodey, G P

    1987-01-01

    The in vitro activities of 16 antimicrobial agents against 14 clinical isolates of Citrobacter diversus and 27 isolates of Citrobacter freundii were studied. C. freundii isolates were more resistant, being susceptible only to amikacin, netilmicin, gentamicin, imipenem, ciprofloxacin, and enoxacin. C. diversus isolates were susceptible to many more of the agents tested.

  6. CLINICOMICROBIOLOGICAL STUDY OF INFECTIONS DUE TO CITROBACTER SPECIES

    OpenAIRE

    Dhanya; Sevitha

    2015-01-01

    BACKGROUND & OBJECTIVES: Citrobacter species have emerged as important nosocomial pathogens . The infections caused by this organism include UTI , wound infection , Neonatal sepsis , pulmonary infection , brain abscess , meningitis . The organism is recovered from a variety of clinical specimen incl uding pus , urine , sputum . Antibiotic resistance is on rise among the Citrobacter spp . The present study w...

  7. Isolation and characterization of cytotoxic, aggregative Citrobacter freundii.

    Directory of Open Access Journals (Sweden)

    Li Bai

    Full Text Available Citrobacter freundii is an infrequent but established cause of diarrhea in humans. However, little is known of its genetic diversity and potential for virulence. We analyzed 26 isolates, including 12 from human diarrheal patients, 2 from human fecal samples of unknown diarrheal status, and 12 from animals, insects, and other sources. Pulsed field gel electrophoresis using XbaI allowed us to divide the 26 isolates into 20 pulse types, while multi-locus sequence typing using 7 housekeeping genes allowed us to divide the 26 isolates into 6 sequence types (STs with the majority belonging to 4 STs. We analyzed adhesion and cytotoxicity to HEp-2 cells in these 26 strains. All were found to adhere to HEp-2 cells. One strain, CF74, which had been isolated from a goat, showed the strongest aggregative adhesion pattern. Lactate dehydrogenase (LDH released from HEp-2 cells was evaluated as a measure of cytotoxicity, averaging 7.46%. Strain CF74 induced the highest level of LDH, 24.3%, and caused >50% cell rounding, detachment, and death. We named strain CF74 "cytotoxic and aggregative C. freundii." Genome sequencing of CF74 revealed that it had acquired 7 genomic islands, including 2 fimbriae islands and a type VI secretion system island, all of which are potential virulence factors. Our results show that aggregative adherence and cytotoxicity play an important role in the pathogenesis of C. freundii.

  8. Citrobacter koseri septicaemia in a holstein calf.

    Science.gov (United States)

    Komine, M; Massa, A; Moon, L; Mullaney, T

    2014-11-01

    A 4-day-old male Holstein calf with dull mentation, nystagmus and blindness was humanely destroyed and subject to necropsy examination. Gross lesions included severe suppurative meningitis characterized by diffuse cloudy thickening of the meninges, bilateral hypopyon and fibrinosuppurative polyarthritis affecting the hocks. Citrobacter koseri was isolated from the meninges, ocular fluid, synovial fluid, spleen and small intestine. Microscopically, there was neutrophilic and histiocytic meningitis with intralesional bacilli, endophthalmitis, neutrophilic splenitis and multiple renal microabscesses. Failure of passive transfer of colostrum was confirmed. This appears to be the first characterization of septicaemia in a calf caused by C. koseri, with lesions comparable with those described in human neonates.

  9. Characterization of Five Podoviridae Phages Infecting Citrobacter freundii.

    Science.gov (United States)

    Hamdi, Sana; Rousseau, Geneviève M; Labrie, Simon J; Kourda, Rim S; Tremblay, Denise M; Moineau, Sylvain; Slama, Karim B

    2016-01-01

    Citrobacter freundii causes opportunistic infections in humans and animals, which are becoming difficult to treat due to increased antibiotic resistance. The aim of this study was to explore phages as potential antimicrobial agents against this opportunistic pathogen. We isolated and characterized five new virulent phages, SH1, SH2, SH3, SH4, and SH5 from sewage samples in Tunisia. Morphological and genomic analyses revealed that the five C. freundii phages belong to the Caudovirales order, Podoviridae family, and Autographivirinae subfamily. Their linear double-stranded DNA genomes range from 39,158 to 39,832 bp and are terminally redundant with direct repeats between 183 and 242 bp. The five genomes share the same organization as coliphage T7. Based on genomic comparisons and on the phylogeny of the DNA polymerases, we assigned the five phages to the T7virus genus but separated them into two different groups. Phages SH1 and SH2 are very similar to previously characterized phages phiYeO3-12 and phiSG-JL2, infecting, respectively, Yersinia enterocolitica and Salmonella enterica, as well as sharing more than 80% identity with most genes of coliphage T7. Phages SH3, SH4, and SH5 are very similar to phages K1F and Dev2, infecting, respectively, Escherichia coli and Cronobacter turicensis. Several structural proteins of phages SH1, SH3, and SH4 were detected by mass spectrometry. The five phages were also stable from pH 5 to 10. No genes coding for known virulence factors or integrases were found, suggesting that the five isolated phages could be good candidates for therapeutic applications to prevent or treat C. freundii infections. In addition, this study increases our knowledge about the evolutionary relationships within the T7virus genus.

  10. Brain abscess caused by Citrobacter koseri infection in an adult.

    Science.gov (United States)

    Liu, Heng-Wei; Chang, Chih-Ju; Hsieh, Cheng-Ta

    2015-04-01

    Citrobacter koseri is a gram-negative bacillus that causes mostly meningitis and brain abscesses in neonates and infants. However, brain abscess caused by Citrobacter koseri infection in an adult is extremely rare, and only 2 cases have been described. Here, we reported a 73-year-old male presenting with a 3-week headache. A history of diabetes mellitus was noted. The images revealed a brain abscess in the left frontal lobe and pus culture confirmed the growth of Citrobacter koseri. The clinical symptoms improved completely postoperatively.

  11. A case of emphysematous pyelonephritis induced by Citrobacter freundii infection

    Directory of Open Access Journals (Sweden)

    Youichi Yanagawa

    2013-01-01

    Full Text Available A 79-year-old female with diabetes mellitus had general fatigue, a high fever and vomiting. A CT revealed acute emphysematous pyelonephritis (EPN. A nephrectomy was performed on the 2 nd hospital day. The results of the blood culture showed the presence of Citrobacter freundii infection. The patient′s post-operative course was uneventful. This case is the second reported case of EPN induced by Citrobacter freundii. Bacteremia induced by Citrobacter freundii infection typically results in a high mortality rate. In this case, the early diagnosis of the EPN using CT and immediate medical treatment, including urgent elective nephrectomy, were key to the favorable outcome.

  12. Citrobacter koseri folliculitis of the face.

    Science.gov (United States)

    Raia, D D; Barbareschi, M; Veraldi, S

    2015-10-01

    We report a case of severe Citrobacter koseri folliculitis of the face in a boy with acne. A 15-year-old boy affected by acne was admitted because of a rash located on the face. Dermatological examination revealed two large plaques, with numerous pustules, eschars and crusts, located bilaterally and symmetrically on the cheeks. Three bacteriological examinations were positive for C. koseri. The patient was successfully treated with i.m. ceftriaxone. C. koseri is a Gram-negative, aerobic, mobile, nonsporulating bacillus belonging to the Enterobacteriaceae family. It can cause meningitis, central nervous system abscess and sepsis, almost exclusively in infants and immunocompromised hosts. Respiratory tract and urinary infections have been reported in elderly people. Furthermore, rare cases of skin infections have been described.

  13. Musculoskeletal infections associated with Citrobacter koseri.

    Science.gov (United States)

    Kwaees, T A; Hakim, Z; Weerasinghe, C; Dunkow, P

    2016-09-01

    Introduction Citrobacter koseri is a well known cause of central nervous system infections in the paediatric setting. Musculoskeletal infections caused by C koseri are rare, with only 14 previously reported cases. We present the first recorded case of C koseri induced septic arthritis of the knee along with a review of the literature. Methods A search of the PubMed, Embase(®) and Google Scholar™ databases was undertaken. Only complete or near complete cases were reviewed. Findings Fourteen musculoskeletal infections were identified. Of these, five were associated with an operative procedure and five involved a septic joint. Surgical treatment was required in the majority of cases and cure was achieved in all cases following prolonged antibiotic use. Conclusions C koseri associated musculoskeletal infections may complicate primary orthopaedic procedures. The organism can present aggressively and can be difficult to identify microbiologically. It is sensitive to newer generation beta-lactams, cephalosporin-based antibiotics and timely surgery.

  14. Biochemical Identification of Citrobacter Species Defined by DNA Hybridization and Description of Citrobacter gillenii sp. nov. (Formerly Citrobacter Genomospecies 10) and Citrobacter murliniae sp. nov. (Formerly Citrobacter Genomospecies 11)

    OpenAIRE

    Brenner, Don J.; O’Hara, Caroline M.; Grimont, Patrick A. D.; Janda, J. Michael; Falsen, Enevold; Aldova, Eva; Ageron, Elisabeth; Schindler, Jiri; Abbott, Sharon L.; Steigerwalt, Arnold G.

    1999-01-01

    Recent work describing six named species and two unnamed genomospecies within Citrobacter has enlarged the genus to 11 species. DNA relatedness and phenotypic tests were used to determine how well these species can be identified. One hundred thirty-six strains were identified to species level by DNA relatedness and then identified phenotypically in a blinded fashion. By using conventional tests, 119 of the 136 strains (88%) were correctly identified to species level. Three additional strains ...

  15. Characterization of phiCFP-1, a virulent bacteriophage specific for Citrobacter freundii.

    Science.gov (United States)

    Zhao, Xiangna; Huang, Simo; Zhao, Jiangtao; He, Xiaoming; Li, Erna; Li, Huan; Liu, Wei; Zou, Dayang; Wei, Xiao; Wang, Xuesong; Dong, Derong; Yang, Zhan; Yan, Xiabei; Shen, Zhiqiang; Yuan, Jing

    2016-05-01

    Citrobacter freundii, a Gram-negative bacterium, causes many opportunistic infections. Bacteriophage phiCFP-1 was isolated and characterized by its ability to lyse the multidrug-resistant clinical C. freundii strain P10159. Transmission electron microscopy showed that the phage has an icosahedral head and a short tail, making it a Podoviridae family member. In a single-step growth experiment, phiCFP-1 exhibited an eclipse period of 20 min and a burst size of 100 particles per cell. Its genome assembled as a circular molecule when genomic sequencing was completed. However, based on genome content and organization, it was categorized as a classic T7-related phage, and such phages are known to have linear genomes with direct terminal repeats. With the quick and simple method established herein, the 38,625-bp linear double-stranded DNA with 229-bp direct terminal repeats was accurately identified. The genome contained 43 putative open reading frames and no tRNA genes. Using a proteomics-based approach, seven viral and two host proteins from purified phiCFP-1 particles were identified. Comparative genomics and recombination analyzes revealed close genetic relatedness among phiCFP-1, phiYeO3-12/vB_YenP_AP5 (from Yersinia enterocolitica O3), and phiSG-JL2 (from Salmonella enterica).

  16. Citrobacter amalonaticus human urinary tract infections, Marseille, France.

    Science.gov (United States)

    Garcia, V; Abat, C; Moal, V; Rolain, J-M

    2016-05-01

    Citrobacter amalonaticus is a bacterium that has rarely been reported as a human pathogen. Here we report four cases of C. amalonaticus infections occurring in patients hospitalized in Marseille, France, and review all cases described in the published literature.

  17. Phosphatase production and activity in Citrobacter freundii and a naturally occurring, heavy-metal-accumulating Citrobacter sp.

    Science.gov (United States)

    Montgomery, D M; Dean, A C; Wiffen, P; Macaskie, L E

    1995-10-01

    The ability of a naturally occurring Citrobacter sp. to accumulate cadmium has been attributed to cellular precipitation of CdHPO4, utilizing HPO4(2-) liberated via the activity of an overproduced, Cd-resistant acid-type phosphatase. Phosphatase production and heavy metal accumulation by batch cultures of this strain (N14) and a phosphatase-deficient mutant were compared with two reference strains of Citrobacter freundii. Only strain N14 expressed a high level of acid phosphatase and accumulated lanthanum and uranyl ion enzymically. Acid phosphatase is regulated via carbon-starvation; although the C. freundii strains overexpressed phosphatase activity in carbon-limiting continuous culture, this was approximately 20-fold less than the activity of strain N14 grown similarly. Citrobacter strain N14 was originally isolated from a metal-contaminated soil environment; phosphatase overproduction and metal accumulation were postulated as a detoxification mechanism. However, application of Cd-stress, and enrichment for Cd-resistant C. freundii ('training'), reduced the phosphatase activity of this organism by about 50% as compared to Cd-unstressed cultures. The acid phosphatase of C. freundii and Citrobacter N14 had a similar pattern of resistance to some diagnostic reagents. The enzyme of the latter is similar to the PhoN acid phosphatase of Salmonella typhimurium described by other workers; the results are discussed with respect to the known phosphatases of the enterobacteria.

  18. Characterization of qnrB-like genes in Citrobacter species of the American Type Culture Collection.

    Science.gov (United States)

    Saga, Tomoo; Sabtcheva, Stefana; Mitsutake, Kotaro; Ishii, Yoshikazu; Tateda, Kazuhiro; Yamaguchi, Keizo; Kaku, Mitsuo

    2013-06-01

    Among five American Type Culture Collection (ATCC) Citrobacter strains, qnrB60 in Citrobacter freundii ATCC 6879, an isolate from the preantibiotic era, and qnrB61 in Citrobacter braakii ATCC 51113(T), a type strain belonging to the C. freundii complex, were identified. Meanwhile, a truncated qnrB-like pseudogene was identified in C. freundii ATCC 8090(T) and ATCC 43864. No qnrB-like sequence was found in Citrobacter koseri ATCC 27028(T). These findings underscore the close relationship between this species and qnrB.

  19. Citrobacter koseri Pneumonia As Initial Presentation of Underlying Pulmonary Adenocarcinoma

    Science.gov (United States)

    Pennington, Kelly; Van Zyl, Martin; Escalante, Patricio

    2016-01-01

    Citrobacter koseri is a motile, gram-negative rod traditionally known to cause infection in individuals with significant comorbidities and immunocompromised status. While most cases represent nosocomial infections, rarely community-acquired infections have been reported. We present a previously healthy man in his 60s with C. koseri pneumonia who was subsequently found to have underlying pulmonary adenocarcinoma, illustrating the need for further investigation for immunodeficiency and/or intrapulmonary pathology.

  20. Molecular analysis of type 3 fimbrial genes from Escherichia coli, Klebsiella and Citrobacter species

    Directory of Open Access Journals (Sweden)

    McEwan Alastair G

    2010-06-01

    Full Text Available Abstract Background Catheter-associated urinary tract infection (CAUTI is the most common nosocomial infection in the United States and is caused by a range of uropathogens. Biofilm formation by uropathogens that cause CAUTI is often mediated by cell surface structures such as fimbriae. In this study, we characterised the genes encoding type 3 fimbriae from CAUTI strains of Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Citrobacter koseri and Citrobacter freundii. Results Phylogenetic analysis of the type 3 fimbrial genes (mrkABCD from 39 strains revealed they clustered into five distinct clades (A-E ranging from one to twenty-three members. The majority of sequences grouped in clade A, which was represented by the mrk gene cluster from the genome sequenced K. pneumoniae MGH78578. The E. coli and K. pneumoniae mrkABCD gene sequences clustered together in two distinct clades, supporting previous evidence for the occurrence of inter-genera lateral gene transfer. All of the strains examined caused type 3 fimbriae mediated agglutination of tannic acid treated human erythrocytes despite sequence variation in the mrkD-encoding adhesin gene. Type 3 fimbriae deletion mutants were constructed in 13 representative strains and were used to demonstrate a direct role for type 3 fimbriae in biofilm formation. Conclusions The expression of functional type 3 fimbriae is common to many Gram-negative pathogens that cause CAUTI and is strongly associated with biofilm growth. Our data provides additional evidence for the spread of type 3 fimbrial genes by lateral gene transfer. Further work is now required to substantiate the clade structure reported here by examining more strains as well as other bacterial genera that make type 3 fimbriae and cause CAUTI.

  1. Structural and serological studies on the O-antigen show that Citrobacter youngae PCM1505 must be classified to a new Citrobacter O-serogroup.

    Science.gov (United States)

    Katzenellenbogen, Ewa; Kocharova, Nina A; Górska-Frączek, Sabina; Gamian, Andrzej; Shashkov, Alexander S; Knirel, Yuriy A

    2012-10-01

    The O-polysaccharide obtained by mild acid hydrolysis of the lipopolysaccharide of Citrobacter youngae PCM1505 was studied by sugar and methylation analyses along with 1D and 2D (1)H and (13)C NMR spectroscopies. The following structure of the tetrasaccharide repeating unit of the polysaccharide was established: [Formula: see text]. Structural and serological data obtained earlier and in this work show that the strain studied is a candidate to a new Citrobacter O-serogroup.

  2. Glycerol assimilation and production of 1,3-propanediol by Citrobacter amalonaticus Y19.

    Science.gov (United States)

    Ainala, Satish Kumar; Ashok, Somasundar; Ko, Yeounjoo; Park, Sunghoon

    2013-06-01

    Citrobacter amalonaticus Y19 (Y19) was isolated because of its ability for carbon monoxide-dependent hydrogen production (water-gas shift reaction). This paper reports the assimilation of glycerol and the production of 1,3-propanediol (1,3-PDO) by Y19. Genome sequencing revealed that Y19 contained the genes for the utilization of glycerol and 1,2-propanediol (pdu operon) along with those for the synthesis of coenzyme B12 (cob operon). On the other hand, it did not possess the genes for the fermentative metabolism of glycerol of Klebsiella pneumoniae, which consists of both the oxidative (dhaD and dhaK) and reductive (dhaB and dhaT) pathways. In shake-flask cultivation under aerobic conditions, Y19 could grow well with glycerol as the sole carbon source and produced 1,3-PDO. The level of 1,3-PDO production was improved when vitamin B12 was added to the culture medium under aerobic conditions. Under anaerobic conditions, cell growth and 1,3-PDO production on glycerol was also possible, but only when an exogenous electron acceptor, such as nitrate or fumarate, was added. This is the first report of the glycerol metabolism and 1,3-PDO production by C. amalonaticus Y19.

  3. Acute death associated with Citrobacter freundii infection in an African elephant (Loxodonta africana).

    Science.gov (United States)

    Ortega, Joaquín; Corpa, Juan M; Orden, José A; Blanco, Jorge; Carbonell, María D; Gerique, Amalia C; Latimer, Erin; Hayward, Gary S; Roemmelt, Andreas; Kraemer, Thomas; Romey, Aurore; Kassimi, Labib B; Casares, Miguel

    2015-09-01

    A 21-year-old male African elephant (Loxodonta africana) died suddenly with no previous medical history. Grossly, there were severe multifocal epicardial and endocardial hemorrhages of the atria and ventricles, hydropericardium, multifocal pleural hemorrhages, and severe pulmonary congestion and edema. Histologically, there was fibrinoid vasculitis and thrombosis in the heart and lung and myocardial necrosis. Citrobacter freundii was isolated in abundance in pure culture from liver and heart samples. Low levels of multiples types of elephant endotheliotropic herpesvirus (EEHV-6, EEHV-2B, and EEHV-3A) were detected in spleen samples, but not in heart samples. The levels of EEHV DNA found were much lower than those usually associated with acute EEHV hemorrhagic disease, and many other genomic loci that would normally be found in such cases were evidently below the level of detection. Therefore, these findings are unlikely to indicate lethal EEHV disease. Polymerase chain reaction for encephalomyocarditis virus (EMCV) and toxicology for oleander (Nerium oleander) were negative. Stress, resulting from recent transport, and antimicrobial therapy may have contributed to the death of this animal.

  4. Community-Acquired Pneumonia and Empyema Caused by Citrobacter koseri in an Immunocompetent Patient

    Directory of Open Access Journals (Sweden)

    Miguel Angel Ariza-Prota

    2015-01-01

    Full Text Available Citrobacter species, belonging to the family Enterobacteriaceae, are environmental organisms commonly found in soil, water, and the intestinal tracts of animals and humans. Citrobacter koseri is known to be an uncommon but serious cause of both sporadic and epidemic septicemia and meningitis in neonates and young infants. Most cases reported have occurred in immunocompromised hosts. The infections caused by Citrobacter are difficult to treat with usual broad spectrum antibiotics owing to rapid generation of mutants and have been associated with high death rates in the past. We believe this is the first case described in the literature of a community-acquired pneumonia and empyema caused by Citrobacter koseri in an immunocompetent adult patient.

  5. Fulminant citrobacter meningitis with multiple periventricular abscesses in a three-month-old infant

    Directory of Open Access Journals (Sweden)

    P. Anoop

    2003-12-01

    Full Text Available Citrobacter, a Gram-negative enteric bacillus, is a rare cause of septicemia and meningitis, seldom reported beyond the neonatal period. It is characterized by a fulminant clinical course and a high incidence of complications, including brain abscesses. We studied a three-month-old infant with Citrobacter meningitis, who developed acute communicating hydrocephalus and multiple periventricular brain abscesses while on treatment. The patient died, despite intensive antibiotic treatment directed towards the causative organism, C. diversus.

  6. [Recovery of platinum with immobilized Citrobacter freudii XP05 biomass].

    Science.gov (United States)

    Hu, Hong-Bo; Liu, Yue-Ying; Fu, Jin-Kun; Xue, Ru; Gu, Ping-Ying

    2003-07-01

    The objective of this work was to develop a valuable adsorbent for recovery of platinum by studying the properties of Pt4+ -adsorption with immobilized Citrobacter freudii XP05 biomass. Five methods for immobilization of Citrobacter freudii XP05 biomass were compared. The method with gelatin-alginate sodium as entrapment matrix was considered to be the optimal. Spherical and uniform beads were produced and the SEM micrograph indicated that the cell of strain XP08 were uniformly dispersed within the matrix. The adsorption of Pt4+ by immobilized XP05 biomass was affected with adsorptive time, pH value of the solution, immobilized biomass concentration, Pt4+ initial concentration The adsorption was a rapid process. The optimal pH value for Pt4+ adsorption was 1.5, and its adsorptive capacity increased linearly with increasing Pt4+ initial concentrations in the range of 50 - 250 mg/L. The experimental data could be fitted to Langmuir and Freundlich models of adsorption isotherm. The adsorptive capacity reached 35.2 mg/g under the conditions of 250 Pt4+ mg/L, 2.0 g/L immobilized biomass, pH 1.5 and 30 degrees C for 60 min. 98.7% of Pt4+ adsorbed on immobilized biomass could be desorbed with 0.5 mol HC1/L. The characteristics of dynamic adsorption and desorption of immobilized XP05 biomass in packed-bed reactor were investigated. The saturation uptake was 24.66 mg Pt4+ /g under the conditions of flow rate 1.2 mL/min, pH 1.5, 50 mg Pt4+/L and 1.85 g biomass(dry weight) . Adsorptive efficiency of Pt4 + by the immobilized XP05 biomass was above 78% for 4 cycles of adsorption and desorption. The recovery of platinum from waste platinum catalyst was studied. The adsorptive capacity was 20.94 mg Pt4+/g immobilized biomass under the conditions of 4.0 g/L immobilized XP05 biomass, 117.76 mg Pt4+/L and pH 1.5 for 60 min. The immobilized XP05 biomass is potentially applicable to the recovery of platinum from waste and wastewater containing platinum. PMID:15969064

  7. Production and properties of alpha-amylase from Citrobacter species

    Directory of Open Access Journals (Sweden)

    Ebuta N. Etim-Osowo

    2009-04-01

    Full Text Available Amylase production by Citrobacter sp. isolated from potato was optimized in batch culture studies under shake flask conditions. Effects and interactions of best sources and levels of carbon and nitrogen estimated by 4 x 5 and 4 x 4 factorial experimental arrangements were significant (P < 0.01 on amylase production. Optimal alpha-amylase yield was obtained in a medium containing sorghum flour (2.0 % w/v and a mixture of (NH42SO4 + soybean meal (1.5% w/v with an initial medium pH of 8.0. Under optimum conditions, amylase yield was maximal (0.499 U/ml after 60h incubation at room temperature (28oC ± 2oC. Characterization studies showed that the enzyme had maximum activity at 60oC, retained 100% of its original activities at 60oC for 2h, was maximally active at pH 7.0 and retained 100% of original activities at pH 9.0 for 2h. Enzyme activity was stimulated by urea, Mg2+, Ca2+ and Zn2+ but inhibited by Hg2+.

  8. Multidrug resistant citrobacter: an unusual cause of liver abscess.

    Science.gov (United States)

    Kumar, Prabhat; Ghosh, Soumik; Rath, Deepak; Gadpayle, A K

    2013-01-01

    Liver abscesses are infectious, space occupying lesions in the liver, the two most common abscesses being pyogenic and amoebic. A pyogenic liver abscess (PLA) is a rare condition with a reported incidence of 20 per 100 000 hospital admissions in the western population. The right lobe of the liver is the most common site in both types of liver abscess. Clinical presentation is elusive with complaints of fever, right upper quadrant pain in the abdomen and hepatomegaly with or without jaundice. The aetiology of PLA has changed in the past few decades and may be of biliary, portal, arterial or traumatic origin, but many cases are still cryptogenic. The most common organisms causing PLA are Gram-negative aerobes, especially Escherichia coli and Klebsiella pneumoniae. Studies have shown a high degree of antimicrobial susceptibility of isolated organism resulting in an overall lower mortality in PLA. Here, we present a case of PLA caused by multidrug-resistant Citrobacter freundii, which is an unusual organism to be isolated.

  9. Genome Sequences of 12 Bacterial Isolates Obtained from the Urine of Pregnant Women

    Science.gov (United States)

    Weimer, Cory M.; Deitzler, Grace E.; Robinson, Lloyd S.; Park, SoEun; Hallsworth-Pepin, Kymberlie; Wollam, Aye; Mitreva, Makedonka

    2016-01-01

    The presence of bacteria in urine can pose significant risks during pregnancy. However, there are few reference genome strains for many common urinary bacteria. We isolated 12 urinary strains of Streptococcus, Staphylococcus, Citrobacter, Gardnerella, and Lactobacillus. These strains and their genomes are now available to the research community. PMID:27688327

  10. Genome Sequences of 12 Bacterial Isolates Obtained from the Urine of Pregnant Women.

    Science.gov (United States)

    Weimer, Cory M; Deitzler, Grace E; Robinson, Lloyd S; Park, SoEun; Hallsworth-Pepin, Kymberlie; Wollam, Aye; Mitreva, Makedonka; Lewis, Warren G; Lewis, Amanda L

    2016-01-01

    The presence of bacteria in urine can pose significant risks during pregnancy. However, there are few reference genome strains for many common urinary bacteria. We isolated 12 urinary strains of Streptococcus, Staphylococcus, Citrobacter, Gardnerella, and Lactobacillus These strains and their genomes are now available to the research community. PMID:27688327

  11. Genome Sequences of Nine Gram-Negative Vaginal Bacterial Isolates

    Science.gov (United States)

    Deitzler, Grace E.; Ruiz, Maria J.; Lu, Wendy; Weimer, Cory; Park, SoEun; Robinson, Lloyd S.; Hallsworth-Pepin, Kymberlie; Wollam, Aye; Mitreva, Makedonka

    2016-01-01

    The vagina is home to a wide variety of bacteria that have great potential to impact human health. Here, we announce reference strains (now available through BEI Resources) and draft genome sequences for 9 Gram-negative vaginal isolates from the taxa Citrobacter, Klebsiella, Fusobacterium, Proteus, and Prevotella. PMID:27688330

  12. Genome Sequences of Nine Gram-Negative Vaginal Bacterial Isolates.

    Science.gov (United States)

    Deitzler, Grace E; Ruiz, Maria J; Lu, Wendy; Weimer, Cory; Park, SoEun; Robinson, Lloyd S; Hallsworth-Pepin, Kymberlie; Wollam, Aye; Mitreva, Makedonka; Lewis, Warren G; Lewis, Amanda L

    2016-01-01

    The vagina is home to a wide variety of bacteria that have great potential to impact human health. Here, we announce reference strains (now available through BEI Resources) and draft genome sequences for 9 Gram-negative vaginal isolates from the taxa Citrobacter, Klebsiella, Fusobacterium, Proteus, and Prevotella. PMID:27688330

  13. Citrobacter freundii septicemia in a stranded newborn Cuvier's beaked whale (Ziphius cavirostris).

    Science.gov (United States)

    Fernández, Antonio; Vela, Ana Isabel; Andrada, Marisa; Herraez, Pedro; Díaz-Delgado, Josue; Domínguez, Lucas; Arbelo, Manuel

    2011-10-01

    Citrobacter freundii, a gram-negative enterobacterium, may cause fatal septicemia in humans and animals. Its potential pathogenic role in cetaceans (bottlenose dolphins and beluga whales) has been hypothesized. Here we describe fatal C. freundii septicemia in a stranded newborn Cuvier's beaked whale (Ziphius cavirostris).

  14. Distribution of chitin/chitosan-like bioflocculant-producing potential in the genus Citrobacter.

    Science.gov (United States)

    Kimura, Kazuyuki; Inoue, Takuya; Kato, Dai-Ichiro; Negoro, Seiji; Ike, Michihiko; Takeo, Masahiro

    2013-11-01

    Some strains belonging to the genera Citrobacter and Enterobacter have been reported to produce chitin/chitosan-like bioflocculants (BFs) from acetate. In this study, to investigate the distribution of the BF-producing potential in the genus Citrobacter and to screen stably and highly BF-producing strains, we obtained 36 Citrobacter strains from different culture collection centers, which were distributed among seven species in the genus, and tested for the flocculating activities of their culture supernatants using a kaolin suspension method. As a result, 21 strains belonging to C. freundii (17 strains in 23 strains tested), C. braakii (two in two), C. youngae (one in one), and C. werkmanii (one in two) showed flocculating activity, but this ability was limited to cells grown on acetate. Gas chromatography/mass spectrometry (GC/MS) analysis of the hydrolysates from the BFs of five selected strains indicated that they consisted of glucosamine and/or N-acetylglucosamine, such as the chitin/chitosan-like BF (BF04) produced by Citrobacter sp. TKF04 (Fujita et al. J Biosci Bioeng 89: 40-46, 2000). Gel filtration chromatography using a high-performance liquid chromatography system revealed that the molecular weight ranges of these BFs varied, but the average sizes were all above 1.66 × 10⁶Da.

  15. Utilization of aminoaromatic acids by a methanogenic enrichment culture and by a novel Citrobacter freundii strain

    NARCIS (Netherlands)

    Savelieva, O.; Kotova, I.; Roelofsen, W.; Stams, A.J.M.; Netrusov, A.

    2004-01-01

    Following incubation of mesophilic methanogenic floccular sludge from a lab-scale upflow anaerobic sludge bed reactor used to treat cattle manure wastewater, a stable 5-aminosalicylate-degrading enrichment culture was obtained. Subsequently, a Citrobacter freundii strain, WA1, was isolated from the

  16. Favorable outcome in cerebral abscesses caused by Citrobacter koseri in a newborn infant

    Directory of Open Access Journals (Sweden)

    Sarah Algubaisi

    2015-01-01

    Full Text Available The treatment of brain abscesses in newborn infants is controversial. We report on a 6-week-old infant with multiple brain abscesses caused by Citrobacter koseri that resolved after treatment with combined surgical drainage and intravenous therapy with meropenem and fosfomycin.

  17. Clonal origin of aminoglycoside-resistant Citrobacter freundii isolates in a Danish county

    DEFF Research Database (Denmark)

    Norskov-Lauritsen, N.; Sandvang, Dorthe; Hedegaard, J.;

    2001-01-01

    During 1997, attention was drawn to an increased frequency of aminoglycoside-resistant Citrobacter freundii in a Danish county, when a total of 24 resistant C. freundii isolates was detected. In this study, 15 such isolates were typed by pulsed-field gel electrophoresis, riboprinting and partial...

  18. SYNTHESIS OF L-DOPA BY CITROBACTER FERUNDII RESTING CELLS%Citrobacter freundii休止细胞催化合成L-多巴

    Institute of Scientific and Technical Information of China (English)

    张莉; 李文; 肖正华; 王云霞; 夏仕文

    2003-01-01

    以在L-酪氨酸诱导下高效表达酪氨酸酚解酶的菌株Citrobacter freundii48003-3的休止细胞为生物催化剂,以邻苯二酚、丙酮酸钠、醋酸铵为前体,选择性合成L-DOPA.研究了反应温度、pH和前体浓度等对合成L-DOPA的影响.最优反应条件下,反应12h,L-DOPA的量可达到9.5g/L.

  19. Phosphatase-mediated heavy metal accumulation by a Citrobacter sp. and related enterobacteria.

    Science.gov (United States)

    Macaskie, L E; Bonthrone, K M; Rouch, D A

    1994-08-15

    A Citrobacter sp. was reported previously to accumulate heavy metals as cell-bound heavy metal phosphates. Metal uptake is mediated by the activity of a periplasmic acid-type phosphatase that liberates inorganic phosphate to provide the precipitant ligand for heavy metals presented to the cells. Amino acid sequencing of peptide fragments of the purified enzyme revealed significant homology to the phoN product (acid phosphatase) of some other enterobacteria. These organisms, together with Klebsiella pneumoniae, previously reported to produce acid phosphatase, were tested for their ability to remove uranium and lanthanum from challenge solutions supplemented with phosphatase substrate. The coupling of phosphate liberation to metal bioaccumulation was limited to the metal accumulating Citrobacter sp.; therefore the participation of species-specific additional factors in metal bioaccumulation was suggested.

  20. Morphological alterations on Citrobacter freundii bacteria induced by erythrosine dye and laser light.

    Science.gov (United States)

    Silva, Josmary R; Cardoso, Gleidson; Maciel, Rafael R G; de Souza, Nara C

    2015-01-01

    The effect of the laser irradiation (532 nm) on films prepared from Citrobacter freundii mixed with erythrosine dye was investigated by using atomic force microscopy. It was observed that morphological changes of bacterial surfaces after irradiations, which were attributed to cellular damage of the outer membranes, are a result of a photodynamic effect. The results suggested that the combination of erythrosine and laser light at 532 nm could be a candidate to a photodynamic therapy against C. freundii.

  1. Identification and phylogeny of Enterobacter sakazakii relative to Enterobacter and Citrobacter species

    DEFF Research Database (Denmark)

    Iversen, Carol; Waddington, Michael; On, Stephen L.W.;

    2004-01-01

    The phylogenetic relationships of Enterobacter sakazakii strains were investigated using 16S ribosomal DNA (rDNA) and hsp60 sequencing. Each analysis distributed E. sakazakii strains among four clusters, indicating substantial taxonomic heterogeneity. The E. sakazakii type strain 16S rDNA sequenc...... was 97.8% similar to that of Citrobacter koseri but 97.0% similar to that of Enterobacter cloacae....

  2. Sulfate reduction and copper precipitation by a Citrobacter sp. isolated from a mining area

    Energy Technology Data Exchange (ETDEWEB)

    Qiu Rongliang, E-mail: eesqrl@mail.sysu.edu.cn [School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275 (China)] [Guangdong Provincial Key Laboratory for Environmental Pollution Control and Remediation Technology, Guangzhou 510275 (China); Zhao Benliang; Liu Jinling [School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Huang, Xiongfei [School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275 (China)] [Guangdong Provincial Key Laboratory for Environmental Pollution Control and Remediation Technology, Guangzhou 510275 (China); Li, Qingfei [School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Brewer, Eric [Viridian Environmental LLC, VA 22207 (United States); Wang, Shizhong; Shi, Ning [School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275 (China)

    2009-05-30

    A strain of sulfate-reducing bacteria, designated strain 'DBM', was isolated from sediments of a mining area. Phylogenetic analysis of the 16S rRNA gene sequence of the isolate revealed that it was related to members of the genus Citrobacter, with C. AzoR-4, C. freundii, C. braakii and C. werkmanii being the most closely related species (sequence similarity up to 98%). Few studies have been done on sulfate reduction ability in Citrobacter. Electron microscopy studies showed that the morphology of the strain DBM was rod-shaped. Strain DBM reduced 10 mM of sulfate completely to sulfide within 7 d, and it recovered its sulfate reduction ability after 7 d of aerobic growth. Furthermore, strain DBM effectively precipitated 0.40 mM copper during its growth. Elemental composition of the resulting microbial precipitate was studied using electro-dispersive X-ray spectroscopy, and it was found that the ratio of S:Cu was 1.07. The result was consistent with the formation of copper sulfide. Heavy metal precipitation by Citrobacter sp. strain DBM was a phenomenon that may be useful in the bioremediation of acid mine drainage.

  3. Biosorption of lead, cadmium, and zinc by Citrobacter strain MCM B-181: Characterization studies

    Energy Technology Data Exchange (ETDEWEB)

    Puranik, P.R.; Paknikar, K.M. [Agharkar Research Inst., Pune (India). Div. of Microbial Sciences

    1999-03-01

    The biosorption process for removal of lead, cadmium, and zinc by Citrobacter strain MCM B-181, a laboratory isolate, was characterized. Effects of environmental factors and growth conditions on metal uptake capacity were studied. Pretreatment of biomass with chemical agents increased cadmium sorption efficiency; however, there was no significant enhancement in lead and zinc sorption capacity. Metal sorption by Citrobacter strain MCM B-181 was found to be influenced by the pH of the solution, initial metal concentration, biomass concentration, and type of growth medium. The metal sorption process was not affected by the age of the culture or change in temperature. Equilibrium metal sorption was found to fit the Langmuir adsorption model. Kinetic studies showed that metal uptake by Citrobacter strain MCm B-181 was a fast process, requiring < 20 min to achieve > 90% adsorption efficiency. The presence of cations reduced lead, zinc, and cadmium sorption to the extent of 11.8%, 84.3%, and 33.4%, respectively. When biomass was exposed to multimetal solutions, metals were adsorbed in the order Co{sup 2+} < Ni{sup 2+} < Cd{sup 2+} < Cu{sup 2+}, Zn{sup 2+} < Pb{sup 2+}. A new mathematical model used for batch kinetic studies was found to be highly useful in prediction of experimentally obtained metal concentration profiles as a function of time.

  4. DEGRADATION CHARACTERISTICS OF m-CRESOL BY CITROBACTER FARMERI AND THE ELEMENTARY STUDY OF METABOLIC PATHWAY%间甲酚降解Citrobacter farmeri 的降解特性及代谢途径解析

    Institute of Scientific and Technical Information of China (English)

    彭丽花; 任源; 邓留杰; 张小璇; 韦朝海

    2009-01-01

    考察了在不同温度、pH值、摇床转速、氮源等环境和营养条件下,间甲酚降解菌Citrobacter farmeri对降解速率和降解过程中反应液的TOC值、紫外吸收及酶活的变化.结果表明,Citrobacter farmeri 降解间甲酚的最适温度为35℃,培养基初始pH值为6.5-8.0,摇床转速为170 r·min-1,无机氮比有机氮和氨态氮比硝态氮更利于Citrobacter farmeri/对间甲酚的降解;当间甲酚初始浓度低于375mg·l-1时,Citrobacter farmerifarmeri降解间甲酚符合零级动力学方程;间甲酚初始浓度约为60 mg·I-1时约4 h完全降解,TOC的去除率8 h内可达到77%,之后几乎不变;Citrobacter farmeri 可完全降解约600 mg·l-1的间甲酚,表现出高效与强耐受能力的结合.对酶活的测定发现,儿茶酚1,2-双加氧酶有明显增大,初步判断Citrobacter farmeri以邻位裂解的途径对间甲酚进行降解.

  5. Exoelectrogenic bacterium phylogenetically related to Citrobacter freundii, isolated from anodic biofilm of a microbial fuel cell.

    Science.gov (United States)

    Huang, Jianjian; Zhu, Nengwu; Cao, Yanlan; Peng, Yue; Wu, Pingxiao; Dong, Wenhao

    2015-02-01

    An electrogenic bacterium, named Citrobacter freundii Z7, was isolated from the anodic biofilm of microbial fuel cell (MFC) inoculated with aerobic sewage sludge. Cyclic voltammetry (CV) analysis exhibited that the strain Z7 had relatively high electrochemical activity. When the strain Z7 was inoculated into MFC, the maximum power density can reach 204.5 mW/m(2) using citrate as electron donor. Series of substrates including glucose, glycerol, lactose, sucrose, and rhammose could be utilized to generate power. CV tests and the addition of anode solution as well as AQDS experiments indicated that the strain Z7 might transfer electrons indirectly via secreted mediators.

  6. [Septic shock following platelet transfusion contaminated with Citrobacter koseri in a child with postchemotherapy febrile neutropenia].

    Science.gov (United States)

    Tichit, R; Saumet, L; Marchandin, H; Haouy, S; Latry, P; Sirvent, N

    2016-01-01

    The bacterial transfusion risk is currently the greatest infectious risk of blood transfusion. We report the case of a child with postchemotherapy febrile neutropenia who presented septic shock following platelet transfusion contaminated with Citrobacter koseri. The life-threatening development could have been avoided by strict compliance with good clinical practice. The stability of mortality rates due to adverse effects of bacterial proliferation during platelet transfusions in France since 1994 calls for optimization of all preventive measures throughout the transfusion chain and perfect knowledge of transfusion rules by medical staff and care givers.

  7. Paraffin as oxygen vector modulates tyrosine phenol lyase production by Citrobacter freundii MTCC 2424.

    Science.gov (United States)

    Azmi, Wamik; Kumar, Ajay; Dev, Varun

    2013-06-01

    The efficiency of three oxygen-vectors liquid paraffin, silicone oil and n-dodecane in the production of tyrosine phenol lyase (TPL) by Citrobacter freundii MTCC 2424 was evaluated at 4% (v/v) concentration. The liquid paraffin as oxygenvectors was found to exhibit a stimulatory effect on TPL synthesis. The liquid paraffin at 6% (v/v) resulted in 34% increase in the TPL synthesis accompanied by a 13% increase in the production of cell mass at a 10 L scale. This improvement in TPL and cell mass production in the presence of liquid paraffin can be related to the fact that liquid paraffin was capable of maintaining dissolved O2 concentration above 28% throughout the course of the fermentation. Maintenance of the dissolved O2 concentration above 28% could be viewed in terms of an adequate oxygen supply to the rapidly dividing cells of the bacterium, which in turn resulted in enhanced synthesis of TPL and cell mass.

  8. Decolorization of textile plant effluent by Citrobacter sp. strain KCTC 18061P.

    Science.gov (United States)

    Jang, Moon-Sun; Jung, Byung-Gil; Sung, Nak-Chang; Lee, Young-Choon

    2007-12-01

    Citrobacter sp. strain KCTC 18061P was found to be able to decolorize textile plant effluent containing different types of reactive dyes. Effects of physico-chemical parameters, such as aeration, nitrogen source, glucose and effluent concentrations on the color removal of real dye effluent by this strain were investigated. The observed changes in the visible spectra indicated color removal by the absorption of dye to cells during incubation with the strain. This strain showed higher decolorization ability under aerobic than static culture conditions. With 1% glucose, this strain removed 70% of effluent color within 5 days. Decolorization was not significantly dependent on the nitrogen sources tested. Chemical oxygen demand (COD) and biological oxygen demand (BOD) were decreased in proportion to incubation times, and their removal rates were about 35% and 50%, respectively, at 7 days of culture.

  9. Isolation,Identification and Antibiotics Susceptibility Test of Citrobacter freundii from Procambarus clarkia

    Institute of Scientific and Technical Information of China (English)

    Chen; Honglian; Song; Guangtong; He; Jixiang; Hou; Guanjun; Wang; Yongjie

    2014-01-01

    This experiment was conducted to clarify species and drug resistance of pathogen from the diseased Procambarus clarkia. Pathogenic bacteria from hepatopancreas of the diseased P. clarkia were examined using conventional methods,and then were isolated. The further tests and analysis of the isolated strain were developed,including the regression experiment to P. clarkia,the morphology,physiological and biochemical characteristics,sequence analysis of their 16 S rRNA and gyr B genes,and the susceptibility test to antibiotics. Large colonies with similar morphology and color were obtained. Strain X120523 was identified as Citrobacter freundii,proved to have strong pathogenicity,and was susceptible to quinolones and aminoglycosides.

  10. 微生物燃料电池中一株产电菌Citrobacter freundii的分离及特性研究%ISOLATION AND CHARACTERIZATION OF EXOELECTROGENIC BACTERIUM Citrobacter freundii LY-3 FROM MICROBIAL FUEL CELL

    Institute of Scientific and Technical Information of China (English)

    李颖; 孙永明; 孔晓英; 李连华; 李东; 袁振宏

    2012-01-01

    An exoelectrogenic bacterium LY-3 was isolated from microbial fuel cell. According to its phenotypic, physiological and biochemical characteristics as well as the phylogenetic analysis based on the sequence of 16S rDNA, it was identified as Citrobacter sp. and shared the highest similarities to C. freundi. So we named it as C. freundi LY-3. Cyclic voltammetry experiment showed that strain LY-3 is electrochemical activity. The C. freundi LY-3 is inoculated into the anode chamber of two-chamber MFC and the maximal voltage output was 0. 43 V with 2. 0g/L beef extract as the fuel. The maximal power density is 98. 2mW/m2.%通过形态、生理生化特性及系统进化分析表明,从微生物燃料电池中分离出的产电菌株LY-3与弗氏柠檬酸杆菌(Citrobacter freundii)最相近,将其命名为Citrobacter freundii LY-3.循环伏安扫描显示,该菌株具有电化学活性,在微生物燃料电池中,以牛肉膏为燃料产生的最大电压为0.43V,最大功率密度为98.2mW/m2.

  11. [Microbial contamination of water by pipe and tube materials. 3. Behavior of E. coli, Citrobacter freundii and Klebsiella pneumoniae].

    Science.gov (United States)

    Schoenen, D; Schlömer, G

    1989-08-01

    Materials water comes into contact with can promote the microbial growth as it could be shown before. The reaction of an unspecific microorganism flora and of Legionella pneumophila in pipes and hoses has been described in the two previous communications. The investigation with L. pneumophila has shown that even a pathogen organism can grow upon the materials. Therefore it was of special interest to prove whether indicator organisms for the testing of drinking water can grow in pipes and hoses as well. Escherichia coli, Citrobacter freundii and Klebsiella pneumoniae grew after the experimental contamination for many weeks on the rubber hose until the test was finally stopped, in the other pipes and hoses (glass, high-grade steel, PVC, PE, PA, PTFE and silicone) E. coli could be found for maximal 7 weeks, Citrobacter freundii for 1 week and Klebsiella pneumoniae for maximal 3 weeks. In the copper pipe the organisms could be found only for a few days. PMID:2673263

  12. Citrobacter freundii infection after acute necrotizing pancreatitis in a patient with a pancreatic pseudocyst: a case report

    OpenAIRE

    Larino-Noia Jose; Iglesias-Garcia Julio; Iglesias-Canle Jose; Lozano-Leon Antonio; Dominguez-Muñoz Enrique

    2011-01-01

    Abstract Introduction Infections are the most frequent and severe complications of acute necrotizing pancreatitis with a mortality rate of up to 80 percent. Although experimental and clinical studies suggest that the microbiologic source of pancreatic infection could be enteric, information in this regard is controversial. Case presentation We describe a Citrobacter freundii isolation by endoscopy ultrasound fine needle aspiration in a 80-year-old Caucasian man with pancreatic pseudocyst afte...

  13. Identification, cloning and heterologous expression of active [NiFe]-hydrogenase 2 from Citrobacter sp. SG in Escherichia coli.

    Science.gov (United States)

    Maier, Johannes A H; Ragozin, Sergey; Jeltsch, Albert

    2015-04-10

    Hydrogen (H2) is a potential alternative energy carrier which only produces water and heat upon combustion. Today, industrial hydrogen production mainly uses thermochemical processes based on fossil fuels or electrolysis of water. Therefore, biotechnological approaches to produce H2 from biomass are an interesting alternative. We introduce here a novel direct hydrogen measurement system using a semiconducting device specific for hydrogen detection. Using this device, a bacterium producing considerable amounts of hydrogen under aerobic cultivation was isolated and identified by 16S ribosomal DNA sequencing as Citrobacter sp. The enzyme responsible for the observed hydrogenase activity was partially purified by 3 chromatographic purification steps and could be identified by peptide mass fingerprinting to be a type 2 [NiFe]-hydrogenase. Expression of the [NiFe]-hydrogenase 2 containing operon from Citrobacter sp. SG in Escherichia coli allowed recombinant hydrogen production. The [NiFe]-hydrogenase 2 identified here may be useful for biotechnological hydrogen production. We speculate that the expression of the hydrogenase in Citrobacter may be an adaptation to growth in acidic conditions.

  14. O2-stable membrane-bound [NiFe]hydrogenase from a newly isolated Citrobacter sp. S-77.

    Science.gov (United States)

    Eguchi, Shigenobu; Yoon, Ki-Seok; Ogo, Seiji

    2012-11-01

    Hydrogenases are of great interest due to their potential use in H(2)-based technology. However, most hydrogenases are highly sensitive to O(2), which have been the major bottleneck in hydrogenase studies. Here we report an O(2)-stable membrane-bound [NiFe]hydrogenase (MBH) purified from a newly isolated strain, S-77. According to the 16S rRNA gene sequence and phylogenetic analysis of the strain S-77, it belongs to the genus of Citrobacter. In vitro experiments using the cytoplasmic membrane of strain S-77 suggested that a cytochrome b acts as the physiological electron acceptor of the MBH. The purified MBH was composed of a dimer of heterodimers, consisting of two distinct subunits with the molecular weights of 58.5 and 38.5 kDa. The enzyme showed a specific activity for H(2)-oxidation of 661 U/mg, which is 35-fold greater than that for H(2)-production of 18.7 U/mg. Notably, the MBH showed a remarkable O(2)-stability, maintaining almost 95% of its original activity even after incubation for 30 h in air at 4°C. These results suggest that the O(2)-stable MBH may play an important role in the H(2)-metabolic pathway under the aerobic conditions of Citrobacter sp. S-77. This is the first report of the purification and biochemical characterization of an O(2)-stable MBH from the genus of Citrobacter.

  15. Study on biosorption kinetics and thermodynamics of uranium by Citrobacter freudii

    International Nuclear Information System (INIS)

    Biosorption has been developed as an effective and economic method to treat wastewater containing low concentrations of metal pollutants. In this study, a bacterium, Citrobacter freudii, was used as a biosorbent to adsorb uranium ions. The thermodynamics and kinetics of this adsorption, as well as its mechanism, were investigated. The results indicated that the biosorption rate could be better described by a pseudo 2nd-order model than a pseudo 1st-order model. The adsorption of U (VI) proceeded very rapidly in the first 30 min and subsequently slowed down continuously for a long period. The biosorption isotherm of uranium by C. freudii could be described well by the Langmuir or Freundlich isotherm, and the latter was better. The thermodynamics parameters, ΔHo, ΔGo, and ΔSo were calculated according to the results of the experiment, which showed this biosorption as being endothermic and spontaneous. The authors investigated the active sites of bacteria for biosorption and the results proved that carboxyl in the cell wall played an important role in biosorption

  16. Studies of polypropylene membrane fouling during microfiltration of broth with Citrobacter freundii bacteria

    Directory of Open Access Journals (Sweden)

    Gryta Marek

    2015-12-01

    Full Text Available In this work a fouling study of polypropylene membranes used for microfiltration of glycerol solutions fermented by Citrobacter freundii bacteria was presented. The permeate free of C. freundii bacteria and having a turbidity in the range of 0.72–1.46 NTU was obtained. However, the initial permeate flux (100–110 L/m2h at 30 kPa of transmembrane pressure was decreased 3–5 fold during 2–3 h of process duration. The performed scanning electron microscope observations confirmed that the filtered bacteria and suspensions present in the broth formed a cake layer on the membrane surface. A method of periodical module rinsing was used for restriction of the fouling influence on a flux decline. Rinsing with water removed most of the bacteria from the membrane surface, but did not permit to restore the initial permeate flux. It was confirmed that the irreversible fouling was dominated during broth filtration. The formed deposit was removed using a 1 wt% solution of sodium hydroxide as a rinsing solution.

  17. Effect of surfactant on phenanthrene metabolic kinetics by Citrobacter sp. SA01.

    Science.gov (United States)

    Li, Feng; Zhu, Lizhong; Zhang, Dong

    2014-11-01

    To attain a better understanding of the effects of surfactants on the metabolic kinetics of hydrophobic organic compounds, the biodegradation of phenanthrene by Citrobacter sp. SA01 was investigated in a batch experiment containing Tween 80, sodium dodecyl benzene sulfonate and liquid mineral salt medium. The Monod model was modified to effectively describe the partition, phenanthrene biodegradation and biopolymer production. The results showed that Tween 80 and sodium dodecyl benzene sulfonate (each at 50mg/L) enhanced phenanthrene metabolism and poly-β-hydroxybutyrate production as indicated by the increasing amounts of intermediates (by 17.2% to 47.9%), and percentages of poly-β-hydroxybutyrate (by 107.3% and 33.1%) within the cell dry weight when compared to their absence. The modified Monod model was capable of predicting microbial growth, phenanthrene depletion and biopolymer production. Furthermore, the Monod kinetic coefficients were largely determined by the surfactant-enhanced partition, suggesting that partitioning is a critical process in surfactant-enhanced bioremediation of hydrophobic organic compounds.

  18. Engineered Citrobacter freundii methionine γ-lyase effectively produces antimicrobial thiosulfinates.

    Science.gov (United States)

    Morozova, Elena A; Kulikova, Vitalia V; Rodionov, Alexei N; Revtovich, Svetlana V; Anufrieva, Natalya V; Demidkina, Tatyana V

    2016-01-01

    Antimicrobial activity of thiosulfinates in situ produced by mixtures of Citrobacter freundii methionine γ-lyase (MGL) with new substrates, l-methionine and S-(alkyl/allyl)-l-cysteine sulfoxides has been recently demonstrated (Anufrieva et al., 2015). This opens a way to the rational design of a new biotechnologically relevant antimicrobial drug producer. To increase the efficiency of the enzyme toward sulfoxides, the mutant forms of MGL, with the replacements of active site cysteine 115 with alanine (C115A MGL) and histidine (C115H MGL) were obtained. The replacement of cysteine 115 by histidine results in the loss of activity of the mutant enzyme in the γ-elimination reaction of physiological substrate, whereas the activity in the β-elimination reaction of characteristic substrates persists. However, the catalytic efficiency of C115H MGL in the β-elimination reaction of S-substituted l-cysteine sulfoxides is increased by about an order of magnitude compared to the wild type MGL. The antibacterial activity of C115H MGL mixtures with a number of sulfoxides was assessed against Gram-positive and Gram-negative bacteria. The bacteriostatic effect was more pronounced against Gram-positive than against Gram-negative bacteria, while antibacterial potential proved to be quite similar. Thus, the mutant enzyme C115H MGL is an effective catalyst, in particular, for decomposition of sulfoxides and the pharmacological couples of the mutant form with sulfoxides might be new antimicrobial agents.

  19. Hydrogen production by a new chemoheterotrophic bacterium Citrobacter sp. Y19

    Energy Technology Data Exchange (ETDEWEB)

    Jung, G.Y. [Pusan National Univ. (Korea). Inst. for Environmental Technology and Industry; Kim, J.R.; Park, J.Y. [Pusan National Univ. (Korea). Dept. of Chemical Engineering; Park, S. [Pusan National Univ. (Korea). Inst. for Environmental Technology and Industry; Pusan National Univ. (Korea). Dept. of Chemical Engineering

    2002-06-01

    A newly isolated Citrobacter sp. Y19 grows on organic carbons aerobically and produces hydrogen from carbon monoxide (CO) and water when transferred to anaerobic conditions. Hydrogen production capability of Y19 was studied in serum-bottle and bioreactor cultures. Optimal cell growth was observed at pH 5-8, temperature of 30-40 {sup o} C, oxygen partial pressure of 0.2-0.4 atm. Induction of hydrogen production activity could be carried out efficiently under 20% (v/v) CO when the culture was removed to anaerobic conditions at 12 h. Optimal conditions for hydrogen production were 30-40{sup o} C and pH 5.5-7.5. The maximum hydrogen production activity was observed as 27.1 mmol/gcellh, which was about three times higher than that of Rhodospirillium rubrum. In bioreactor experiments, a stable hydrogen production along with a high activity of 20 mmolH{sub 2}gcellh was observed during the continuous operation of 68 h. (author)

  20. Study on biosorption kinetics and thermodynamics of uranium by Citrobacter freudii

    Energy Technology Data Exchange (ETDEWEB)

    Xie Shuibo [Department of Environment Science and Engineering, Tsinghua University, Beijing 100084 (China) and School of Urban Construction, University of South China, Hengyang, Hunan 421001 (China)], E-mail: xiesbmr@263.net; Yang Jing [School of Urban Construction, University of South China, Hengyang, Hunan 421001 (China); Chen Chao; Zhang Xiaojian [Department of Environment Science and Engineering, Tsinghua University, Beijing 100084 (China); Wang Qingliang; Zhang Chun [School of Urban Construction, University of South China, Hengyang, Hunan 421001 (China)

    2008-01-15

    Biosorption has been developed as an effective and economic method to treat wastewater containing low concentrations of metal pollutants. In this study, a bacterium, Citrobacter freudii, was used as a biosorbent to adsorb uranium ions. The thermodynamics and kinetics of this adsorption, as well as its mechanism, were investigated. The results indicated that the biosorption rate could be better described by a pseudo 2nd-order model than a pseudo 1st-order model. The adsorption of U (VI) proceeded very rapidly in the first 30 min and subsequently slowed down continuously for a long period. The biosorption isotherm of uranium by C. freudii could be described well by the Langmuir or Freundlich isotherm, and the latter was better. The thermodynamics parameters, {delta}H{sup o}, {delta}G{sup o}, and {delta}S{sup o} were calculated according to the results of the experiment, which showed this biosorption as being endothermic and spontaneous. The authors investigated the active sites of bacteria for biosorption and the results proved that carboxyl in the cell wall played an important role in biosorption.

  1. Biohydrogen production by dark fermentation of glycerol using Enterobacter and Citrobacter Sp.

    Science.gov (United States)

    Maru, Biniam T; Constanti, Magda; Stchigel, Alberto M; Medina, Francesc; Sueiras, Jesus E

    2013-01-01

    Glycerol is an attractive substrate for biohydrogen production because, in theory, it can produce 3 mol of hydrogen per mol of glycerol. Moreover, glycerol is produced in substantial amounts as a byproduct of producing biodiesel, the demand for which has increased in recent years. Therefore, hydrogen production from glycerol was studied by dark fermentation using three strains of bacteria: namely, Enterobacter spH1, Enterobacter spH2, and Citrobacter freundii H3 and a mixture thereof (1:1:1). It was found that, when an initial concentration of 20 g/L of glycerol was used, all three strains and their mixture produced substantial amounts of hydrogen ranging from 2400 to 3500 mL/L, being highest for C. freundii H3 (3547 mL/L) and Enterobacter spH1 (3506 mL/L). The main nongaseous fermentation products were ethanol and acetate, albeit in different ratios. For Enterobacter spH1, Enterobacter spH2, C. freundii H3, and the mixture (1:1:1), the ethanol yields (in mol EtOH/mol glycerol consumed) were 0.96, 0.67, 0.31, and 0.66, respectively. Compared to the individual strains, the mixture (1:1:1) did not show a significantly higher hydrogen level, indicating that there was no synergistic effect. Enterobacter spH1 was selected for further investigation because of its higher yield of hydrogen and ethanol.

  2. Proteome responses of Citrobacter werkmanii BF-6 planktonic cells and biofilms to calcium chloride.

    Science.gov (United States)

    Zhou, Gang; Shi, Qing-shan; Huang, Xiao-mo; Xie, Xiao-bao

    2016-02-01

    Calcium ions are well-known as intracellular second messengers that also have an important extracellular structural role for bacteria. Recently, we found that denser biofilms were formed by Citrobacter werkmanii BF-6 in the presence of 400 mM Ca(2+) than that of 12.5mM Ca(2+). Therefore, we employed two-dimensional (2-D) electrophoresis methods to investigate the proteome profiles of planktonic cells and biofilms in BF-6 under different concentrations of Ca(2+). Meanwhile, BF-6 biofilm architecture was also visualized with confocal laser scanning microscopy (CLSM). The results demonstrated that BF-6 biofilms formed at the bottom of microtiter plates when grown in the presence of 400 mM Ca(2+). A total of 151 proteins from planktonic cells and biofilms after exposure of BF-6 cells to 12.5 and 400 mM Ca(2+) were successfully identified. Different gene ontology (GO) and KEGG pathways were categorized and enriched for the above proteins. Growth in the presence of 400 mM Ca(2+) induced more complex signal pathways in BF-6 than 12.5mM Ca(2+). In addition, the biofilm architectures were also affected by Ca(2+). Our results show two different modes of biofilm enhancement for C. werkmanii in the presence of excess Ca(2+) and provide a preliminary expression of these differences based on proteomic assays.

  3. Reduction of azo dyes by flavin reductase from Citrobacter freundii A1

    Directory of Open Access Journals (Sweden)

    Mohd Firdaus Abdul-Wahab

    2012-12-01

    Full Text Available Citrobacter freundii A1 isolated from a sewage treatment facility was demonstrated to be able to effectively decolorize azo dyes as pure and mixed culture. This study reports on the investigation on the enzymatic systems involved. An assay performed suggested the possible involvement of flavin reductase (Fre as an azo reductase. A heterologouslyexpressed recombinant Fre from C. freundii A1 was used to investigate its involvement in the azo reduction process. Three model dyes were used, namely Acid Red 27 (AR27, Direct Blue 15 (DB15 and Reactive Black 5 (RB5. AR27 was found to be reduced the fastest by Fre, followed by RB5, and lastly DB15. Redox mediators nicotinamide adenine dinucleotide (NADH and riboflavin enhance the reduction, suggesting the redox activity of the enzyme. The rate and extent of reduction of the model dyes correlate well with the reduction potentials (Ep. The data presented here strongly suggest that Fre is one of the enzymes responsible for azo reduction in C. freundii A1, acting via an oxidation-reduction reaction.

  4. Impact of cold plasma on Citrobacter freundii in apple juice: inactivation kinetics and mechanisms.

    Science.gov (United States)

    Surowsky, Björn; Fröhling, Antje; Gottschalk, Nathalie; Schlüter, Oliver; Knorr, Dietrich

    2014-03-17

    Various studies have shown that cold plasma is capable of inactivating microorganisms located on a variety of food surfaces, food packaging materials and process equipment under atmospheric pressure conditions; however, less attention has been paid to the impact of cold plasma on microorganisms in liquid foodstuffs. The present study investigates cold plasma's ability to inactivate Citrobacter freundii in apple juice. Optical emission spectroscopy (OES) and temperature measurements were performed to characterise the plasma source. The plasma-related impact on microbial loads was evaluated by traditional plate count methods, while morphological changes were determined using scanning electron microscopy (SEM). Physiological property changes were obtained through flow cytometric measurements (membrane integrity, esterase activity and membrane potential). In addition, mathematical modelling was performed in order to achieve a reliable prediction of microbial inactivation and to establish the basis for possible industrial implementation. C. freundii loads in apple juice were reduced by about 5 log cycles after a plasma exposure of 480s using argon and 0.1% oxygen plus a subsequent storage time of 24h. The results indicate that a direct contact between bacterial cells and plasma is not necessary for achieving successful inactivation. The plasma-generated compounds in the liquid, such as H2O2 and most likely hydroperoxy radicals, are particularly responsible for microbial inactivation.

  5. Metabolic-flux analysis of hydrogen production pathway in Citrobacter amalonaticus Y19

    Energy Technology Data Exchange (ETDEWEB)

    Oh, You-Kwan; Kim, Mi-Sun [Bioenergy Research Center, Korea Institute of Energy Research, Daejeon 305-343 (Korea); Kim, Heung-Joo; Park, Sunghoon [Department of Chemical and Biochemical Engineering and Institute for Environmental Technology and Industry, Pusan National University, Busan 609-735 (Korea); Ryu, Dewey D.Y. [Biochemical Engineering Program, Department of Chemical Engineering and Material Science, University of California, Davis, CA 95616 (United States)

    2008-03-15

    For the newly isolated chemoheterotrophic bacterium Citrobacter amalonaticus Y19, anaerobic glucose metabolism and hydrogen (H{sub 2}) production pathway were studied using batch cultivation and an in silico metabolic-flux analysis. Batch cultivation was conducted under varying initial glucose concentration between 1.5 and 9.5 g/L with quantitative measurement of major metabolites to obtain accurate carbon material balance. The metabolic flux of Y19 was analyzed using a metabolic-pathway model which was constructed from 81 biochemical reactions. The linear optimization program MetaFluxNet was employed for the analysis. When the specific growth rate of cells was chosen as an objective function, the model described the batch culture characteristics of Ci. amalonaticus Y19 reasonably well. When the specific H{sub 2} production rate was selected as an objective function, on the other hand, the achievable maximal H{sub 2} production yield (8.7molH{sub 2}/mol glucose) and the metabolic pathway enabling the high H{sub 2} yield were identified. The pathway involved non-native NAD(P)-linked hydrogenase and H{sub 2} production from NAD(P)H which were supplied at a high rate from glucose degradation through the pentose phosphate pathway. (author)

  6. Purification and characterization of selenocysteine beta-lyase from Citrobacter freundii

    International Nuclear Information System (INIS)

    The purification and characterization of bacterial selenocysteine beta-lyase, an enzyme which specifically catalyzes the cleavage of L-selenocysteine to L-alanine and Se0, are presented. The enzyme, purified to near homogeneity from Citrobacter freundii, is monomeric with a molecular weight of ca. 64,000 and contains 1 mol of pyridoxal 5'-phosphate as a cofactor per mol of enzyme. L-Selenocysteine is the sole substrate. L-Cysteine is a competitive inhibitor of the enzyme. The enzyme also catalyzes the alpha, beta elimination of beta-chloro-L-alanine to form NH3, pyruvate, and Cl- and is irreversibly inactivated during the reaction. The physicochemical properties, e.g., amino acid composition and subunit structure, of the bacterial enzyme are fairly different from those of the pig liver enzyme. However, the catalytic properties of both enzymes, e.g., substrate specificity and inactivation by the substrate or a mechanism-based inactivator, beta-chloro-L-alanine, are very similar

  7. Purification and characterization of selenocysteine beta-lyase from Citrobacter freundii

    Energy Technology Data Exchange (ETDEWEB)

    Chocat, P.; Esaki, N.; Tanizawa, K.; Nakamura, K.; Tanaka, H.; Soda, K.

    1985-08-01

    The purification and characterization of bacterial selenocysteine beta-lyase, an enzyme which specifically catalyzes the cleavage of L-selenocysteine to L-alanine and Se0, are presented. The enzyme, purified to near homogeneity from Citrobacter freundii, is monomeric with a molecular weight of ca. 64,000 and contains 1 mol of pyridoxal 5'-phosphate as a cofactor per mol of enzyme. L-Selenocysteine is the sole substrate. L-Cysteine is a competitive inhibitor of the enzyme. The enzyme also catalyzes the alpha, beta elimination of beta-chloro-L-alanine to form NH3, pyruvate, and Cl- and is irreversibly inactivated during the reaction. The physicochemical properties, e.g., amino acid composition and subunit structure, of the bacterial enzyme are fairly different from those of the pig liver enzyme. However, the catalytic properties of both enzymes, e.g., substrate specificity and inactivation by the substrate or a mechanism-based inactivator, beta-chloro-L-alanine, are very similar.

  8. The Type VI Secretion System Modulates Flagellar Gene Expression and Secretion in Citrobacter freundii and Contributes to Adhesion and Cytotoxicity to Host Cells.

    Science.gov (United States)

    Liu, Liyun; Hao, Shuai; Lan, Ruiting; Wang, Guangxia; Xiao, Di; Sun, Hui; Xu, Jianguo

    2015-07-01

    The type VI secretion system (T6SS) as a virulence factor-releasing system contributes to virulence development of various pathogens and is often activated upon contact with target cells. Citrobacter freundii strain CF74 has a complete T6SS genomic island (GI) that contains clpV, hcp-2, and vgr T6SS genes. We constructed clpV, hcp-2, vgr, and T6SS GI deletion mutants in CF74 and analyzed their effects on the transcriptome overall and, specifically, on the flagellar system at the levels of transcription and translation. Deletion of the T6SS GI affected the transcription of 84 genes, with 15 and 69 genes exhibiting higher and lower levels of transcription, respectively. Members of the cell motility class of downregulated genes of the CF74ΔT6SS mutant were mainly flagellar genes, including effector proteins, chaperones, and regulators. Moreover, the production and secretion of FliC were also decreased in clpV, hcp-2, vgr, or T6SS GI deletion mutants in CF74 and were restored upon complementation. In swimming motility assays, the mutant strains were found to be less motile than the wild type, and motility was restored by complementation. The mutant strains were defective in adhesion to HEp-2 cells and were restored partially upon complementation. Further, the CF74ΔT6SS, CF74ΔclpV, and CF74Δhcp-2 mutants induced lower cytotoxicity to HEp-2 cells than the wild type. These results suggested that the T6SS GI in CF74 regulates the flagellar system, enhances motility, is involved in adherence to host cells, and induces cytotoxicity to host cells. Thus, the T6SS plays a wide-ranging role in C. freundii.

  9. Kinetics study on decolorization of Reactive Red KN-3B by Citrobacter sp. CK3%Citrobacter sp. CK3对活性红KN-3B的脱色反应动力学研究

    Institute of Scientific and Technical Information of China (English)

    赖正; 熊小京; 郑天凌; 林光辉; 张章堂

    2012-01-01

    采用脱色菌Citrobacter sp. CK3,以活性红KN-3B染料为处理对象,在厌氧批式反应条件下,系统考察了pH值,温度和染料浓度对脱色反应速度的影响;通过动力学模拟及反应过程中染料的UV-Vis扫描图分析,探讨了脱色反应机理。结果表明:Citrobacter sp. CK3对活性红KN-3B的脱色反应的适宜pH为7~9;脱色反应速度在温度为32℃时达到最大。染料初浓度从57 mg/L逐渐增大到458 mg/L时脱色率逐渐降低。脱色过程中染料的偶氮键发生断裂,脱色反应符合二级反应动力学。%The kinetic modeling and mechanism with which Citrobacter sp. CK3 removed the textile dye, C.I. Reactive Red 180, from aqueous solution was investigated using different parameters, such as initial dye concentration,pH and temperature. In anaerobic batch experiments, the decolorization efficiency decreased with increase in initial dye concentration. The high decolorization rate was observed at pH of 7 -9 and temperature of 32C. The decolorization followed a second order kinetic model. The UV-Vis spectra analysis revealed that the decolorization process was azo bond cleaved reaction.

  10. NDM-1-Producing Citrobacter freundii, Escherichia coli, and Acinetobacter baumannii Identified from a Single Patient in China.

    Science.gov (United States)

    Huang, Ying-Min; Zhong, Lan-Lan; Zhang, Xue-Fei; Hu, Hang-Tong; Li, Yu-Qi; Yang, Xiao-Rong; Feng, Lian-Qiang; Huang, Xi; Tian, Guo-Bao

    2015-08-01

    We identified New Delhi metallo-β-lactamase (NDM-1)-producing Citrobacter freundii GB032, Escherichia coli GB102, and Acinetobacter baumannii GB661 in urine and stool samples from a single patient in China. Plasmid profiling and Southern blotting indicated that blaNDM-1 from GB032 and that from GB102 were likely located on the same plasmid, while blaNDM-1 from GB661 was located on a very large (>400-kb) plasmid. This case underscores the broad host range of blaNDM-1 and its potential to spread between members of the family Enterobacteriaceae and A. baumannii.

  11. Polymeric and compositional properties of novel extracellular microbial polyglucosamine biopolymer from new strain of citrobacter sp. BL-4.

    Science.gov (United States)

    Kim, Lin-Su; Hong, Soo-Jung; Son, Mi-Kyung; Lee, Yong-Hyun

    2006-02-01

    A novel polyglucosamine polymer, PGB-2, was produced extracellularly from a new strain Citrobacter sp. BL-4 using pH-stat fed batch cultivation. It was composed of 97.3% glucosamine and 2.7% rhamnose; its average molecular weight, solubility in 2% acetic acid and viscosity were 20 kDa, 5 g l(-1) and 2.9 cps, respectively. FT-IR and 1H NMR spectra of PGB-2 revealed a close identity with chitosan from crab shells.

  12. Cloning, sequencing, and overexpression of the genes encoding coenzyme B12-dependent glycerol dehydratase of Citrobacter freundii.

    OpenAIRE

    Seyfried, M.; Daniel, R.; Gottschalk, G

    1996-01-01

    The genes encoding coenzyme B12-dependent glycerol dehydratase of Citrobacter freundii were cloned and overexpressed in Escherichia coli. The B12-free enzyme was purified to homogeneity. It consists of three types of subunits whose N-terminal sequences are in accordance with those deduced from the open reading frames dhaB, dhaC, and dhaE, coding for subunits of 60,433 (alpha), 21,487 (beta), and 16,121 (gamma) Da, respectively. The enzyme complex has the composition alpha2beta2gamma2. Amino a...

  13. Fermentative biohydrogen production by a new chemoheterotrophic bacterium Citrobacter sp. Y19

    Energy Technology Data Exchange (ETDEWEB)

    Youkwan Oh; Sunghoon Park [Changjeon Univ., Pusan (Korea). Dept. of Chemical Engineering; Pusan National Univ. (Korea). Inst. for Environmental Technology and Industry; Eunhee Seol [Changjeon Univ., Pusan (Korea). Dept. of Chemical Engineering; Jung Rae Kim [Pusan National Univ. (Korea). Inst. for Environmental Technology and Industry

    2003-12-01

    A newly isolated Citrobacter sp. Y19 for CO-dependent H{sub 2} production was studied for its capability of fermentative H{sub 2} production in batch cultivation. When glucose was used as carbon source, the pH of the culture medium significantly decreased as fermentation proceeded and H{sub 2} production was seriously inhibited. The use of fortified phosphate at 60-180 mM alleviated this inhibition. By increasing culture temperatures (25-36{sup o}C), faster cell growth and higher initial H{sub 2} production rates were observed but final H{sub 2} production and yield were almost constant irrespective of temperature. Optimal specific H{sub 2} production activity was observed at 36{sup o}C and pH 6-7. The increase of glucose concentration (1-20 g/l) in the culture medium resulted in higher H{sub 2} production, but the yield of H{sub 2} production (mol H{sub 2}/mol glucose) gradually decreased with increasing glucose concentration. Carbon mass balance showed that, in addition to cell mass, ethanol, acetate and CO{sub 2} were the major fermentation products and comprised more than 70% of the carbon consumed. The maximal H{sub 2} yield and H{sub 2} production rate were estimated to be 2.49 mol H{sub 2}/mol glucose and 32.3 mmol H{sub 2}/gcellh, respectively. The overall performance of Y19 in fermentative H{sub 2} production is quite similar to that of most H{sub 2}-producing bacteria previously studied, especially to that of Rhodopseudomonas palustris P4, and this indicates that the attempt to find an outstanding bacterial strain for fermentative H{sub 2} production might be very difficult if not impossible. (author)

  14. The role of active site tyrosine 58 in Citrobacter freundii methionine γ-lyase.

    Science.gov (United States)

    Anufrieva, Natalya V; Faleev, Nicolai G; Morozova, Elena A; Bazhulina, Natalia P; Revtovich, Svetlana V; Timofeev, Vladimir P; Tkachev, Yaroslav V; Nikulin, Alexei D; Demidkina, Tatyana V

    2015-09-01

    In the spatial structure of methionine γ-lyase (MGL, EC 4.4.1.11) from Citrobacter freundii, Tyr58 is located at H-bonding distance to the oxygen atom of the phosphate "handle" of pyridoxal 5'-phosphate (PLP). It was replaced for phenylalanine by site-directed mutagenesis. The X-ray structure of the mutant enzyme was determined at 1.96Å resolution. Comparison of spatial structures and absorption spectra of wild-type and mutant holoenzymes demonstrated that the replacement did not result in essential changes of the conformation of the active site Tyr58Phe MGL. The Kd value of PLP for Tyr58Phe MGL proved to be comparable to the Kd value for the wild-type enzyme. The replacement led to a decrease of catalytic efficiencies in both γ- and β-elimination reactions of about two orders of magnitude as compared to those for the wild-type enzyme. The rates of exchange of C-α- and C-β- protons of inhibitors in D2O catalyzed by the mutant form are comparable with those for the wild-type enzyme. Spectral data on the complexes of the mutant form with the substrates and inhibitors showed that the replacement led to a change of rate the limiting step of the physiological reaction. The results allowed us to conclude that Tyr58 is involved in an optimal positioning of the active site Lys210 at some stages of γ- and β-elimination reactions. This article is part of a Special Issue entitled: Cofactor-dependent proteins: evolution, chemical diversity and bio-applications.

  15. Microbial degradation of Paclitaxel using Citrobacter amalonaticus Rashtia isolated from pharmaceutical wastewater: kinetic and thermodynamic study.

    Science.gov (United States)

    Zamani, Hojjatolah; Grakoee, Seyed Reza; Rakhshaee, Roohan

    2016-08-01

    Paclitaxel is a highly toxic anticancer agent which is used in a wide range against ovarian, breast, lung, and prostate cancers. Paclitaxel is manufactured recently in the north of Iran which may lead to the introduction of the drug into the environment via pharmaceutical wastewater. To our knowledge, Paclitaxel degradation is currently performed using physicochemical methods and biological degradation of Paclitaxel has not been reported. In this study, a Paclitaxel degrading bacterium was isolated from pharmaceutical wastewater for the first time. The bacterium was identified using biochemical and molecular assays and its Paclitaxel degradation potential was evaluated using High Performance Liquid Chromatography (HPLC). In addition, kinetic and thermodynamic study of Paclitaxel degradation at different experimental conditions was performed. A Citrobacter species named as C. amalonaticus Rashtia able to degrade and utilize Paclitaxel as the sole carbon source was isolated. The isolated strain tolerated high level concentration of Paclitaxel (0.4 mg/mL) in liquid culture media and was able to degrade spillage-level concentrations of the drug (0.01-0.1 mg/mL) with 87-93 % efficacy under aerobic condition. Kinetic and thermodynamic study at different pHs (4.0, 7.0 and 10.0) and temperatures (285, 295 and 310 K) revealed that Paclitaxel degradation is a non-spontaneous process and the highest rate constant was observed in the basic condition and at the highest temperature. The ΔG values at 285, 295 and 310 K were determined 103.3, 105.9 and 109.9 kJ/mol, respectively. In addition, The ΔH and activation energy (Ea) of the process were determined +28.7 kJ/mol and +30.87 kJ/mol, respectively.

  16. 1,3-Propanediol production by Escherichia coli using genes from Citrobacter freundii atcc 8090.

    Science.gov (United States)

    Przystałowska, Hanna; Zeyland, Joanna; Kośmider, Alicja; Szalata, Marlena; Słomski, Ryszard; Lipiński, Daniel

    2015-01-01

    Compared with chemical synthesis, fermentation has the advantage of mass production at low cost, and has been used in the production of various industrial chemicals. As a valuable organic compound, 1,3-propanediol (1,3-PDO) has numerous applications in the production of polymers, lubricants, cosmetics and medicines. Here, conversion of glycerol (a renewable substrate and waste from biodiesel production) to 1,3-PDO by E. coli bacterial strain carrying altered glycerol metabolic pathway was investigated. Two gene constructs containing the 1,3-PDO operon from Citrobacter freundii (pCF1 and pCF2) were used to transform the bacteria. The pCF1 gene expression construct contained dhaBCE genes encoding the three subunits of glycerol dehydratase, dhaF encoding the large subunit of the glycerol dehydratase reactivation factor and dhaG encoding the small subunit of the glycerol dehydratase reactivating factor. The pCF2 gene expression construct contained the dhaT gene encoding the 1,3-propanediol dehydrogenase. Expression of the genes cloned in the above constructs was under regulation of the T7lac promoter. RT-PCR, SDS-PAGE analyses and functional tests confirmed that 1,3-PDO synthesis pathway genes were expressed at the RNA and protein levels, and worked flawlessly in the heterologous host. In a batch flask culture, in a short time applied just to identify the 1,3-PDO in a preliminary study, the recombinant E. coli bacteria produced 1.53 g/L of 1,3-PDO, using 21.2 g/L of glycerol in 72 h. In the Sartorius Biostat B Plus reactor, they produced 11.7 g/L of 1,3-PDO using 24.2 g/L of glycerol, attaining an efficiency of 0.58 [mol1,3-PDO/molglycerol].

  17. Species identification of strains belonging to genus Citrobacter using the biochemical method and MALDI-TOF mass spectrometry.

    Science.gov (United States)

    Kolínská, Renáta; Spanělová, Petra; Dřevínek, Michal; Hrabák, Jaroslav; Zemličková, Helena

    2015-01-01

    Strains of genus Citrobacter (152 isolates from 1950 to 1988 deposited in the Czech National Collection of Type Cultures, Prague) were re-classified using biological and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) methods. One-hundred thirty-six strains (ca. 90 %) were identified to the species level using the biological method with evaluation by Farmer matrix. MALDI-TOF MS exhibited better identification capability, the data being more compact; the method was unambiguously successful in typing 145 (95 %) strains. Comparison of the results of identification by the two methods revealed differences (for 12 samples) in identified species which, considering all biochemical and/or MS characteristics, could be attributed to the natural variability of strains and close relation of the misidentified species (all of them belonged to the Citrobacter freundii complex). Taking into account all the above data, both methods can be considered reliable; however, the MALDI-TOF MS exhibits higher accuracy, efficiency, and rapidity.

  18. Effects of nutritional and environmental conditions on planktonic growth and biofilm formation of Citrobacter werkmanii BF-6.

    Science.gov (United States)

    Zhou, Gang; Li, Long-jie; Shi, Qing-shan; Ouyang, You-sheng; Chen, Yi-ben; Hu, Wen-feng

    2013-12-01

    Citrobacter sp. is a cause of significant opportunistic nosocomial infection and is frequently found in human and animal feces, soil, and sewage water, and even in industrial waste or putrefaction. Biofilm formation is an important virulence trait of Citrobacter sp. pathogens but the process and characteristics of this formation are unclear. Therefore, we employed in vitro assays to study the nutritional and environmental parameters that might influence biofilm formation of C. werkmanii BF-6 using 96-well microtiter plates. In addition, we detected the relative transcript levels of biofilm formation genes by RT-PCR. Our results indicated that the capacity of C. werkmanii BF-6 to form biofilms was affected by culture temperature, media, time, pH, and the osmotic agents glucose, sucrose, NaCl, and KCl. Confocal laser scanning microscopy results illustrated that the structure of biofilms and extracellular polysaccharide was influenced by 100 mM NaCl or 100 mM KCl. In addition, nine biofilm formation genes (bsmA, bssR, bssS, csgD, csgE, csgF, mrkA, mrkB, and mrkE) were found to contribute to planktonic and biofilm growth. Our data suggest that biofilm formation by C. werkmanii BF-6 is affected by nutritional and environmental factors, which could pave the way to the prevention and elimination of biofilm formation using proper strategies.

  19. 枸橼酸杆菌医院感染特点及耐药性检测%Nosocomial infection and antibiotic resistance surveillance of citrobacter

    Institute of Scientific and Technical Information of China (English)

    刘红梅; 姜玉昌

    2011-01-01

    Objective To investigate the distribution and antibiotic resistance of citrobacter for anti-infection therapy .Methods The citrobacter were identified by Walk-Away-40 according to《National Guide to Clinical Laboratory Procedures》 .Kirby-Bauer(K-B ) were used for drug sensitive test and WHONET5.4 for statistics .Results We isolated 172 strains of citrobacteT .Of which C .freundii was major (70.3%) ,then Citrobacter am alonaticus (14.0%) and Citrobacter diversus (5.2%).In 172 strains of citrobacte which came mainly from respiratoy tract (67 .4%) and urogenital tract was the next(22.1% ).The infected ward were neurology ward (29.1%) ,respiratoy ward(27.9%)nephrology ward (16.9%)and oncology ward(11.0%).Drug sensitive test showed higher resistance rate in 172 strains of citrobacter to ampicillin ,cefazolin and Cefoxitin were above 87% ,while to amikacin ,imipenem and sulperazone were lower 20% .Conclusion C .freundii was the common citrobacter in nosocomial infection and came mainly from respiratory tract.Citrobacter produced multi-β-lactam ase resistance .Imipenem ,sulperazone and amikacin have higher antibacterial activities to citrobacte.%目的 了解枸橼酸杆菌在医院感染中的分布特点及耐药特性,为临床抗感染治疗提供依据.方法 细菌分离培养按进行;采用WalkAway-40全自动细菌鉴定仪对临床分离菌株进行菌种鉴定;采用K-B法进行药敏试验,用WHONET5.4软件进行统计分析.结果 共分离枸橼酸杆菌属细菌172株,其中弗劳地枸橼酸杆菌最多,占70.3%,其次为丙二酸盐阴性枸橼酸杆菌和异型枸橼酸杆菌,分别占14.0%和5.2%,172株枸橼酸杆菌的感染部位以呼吸道最多(67.4%),其次为泌尿生殖道(22.1%);病区分布主要为神经内科病房、呼吸内科病房、肾内科病房和肿瘤病房,分别占29.1%、27.9%、16.9%和11.0%;药敏结果显示,172株枸橼酸杆菌对氨苄西林、头孢唑啉、头孢

  20. Morphological Evolution during the Formation of Carbonate Spherulite in Citrobacter freundii Culture%Citrobacter freundii作用下球状碳酸盐矿物的形态演化过程研究

    Institute of Scientific and Technical Information of China (English)

    马恒; 李福春; 苏宁; 李学林

    2009-01-01

    不少微生物都具有形成球状碳酸盐矿物的能力.对形成过程的动态跟踪研究是了解球状碳酸盐矿物形成机理的关键.利用光学显微镜和电子显微镜对Citrobacter freundii作用下球状碳酸盐矿物的形成过程进行了跟踪研究.结果表明,纳米晶体在有机物质的包裹下逐渐聚集.最终生长为具有辐射状内部结构和菱形表面纹理的球状构造.在球状构造形成之前,矿物集合体经历了花形、哑铃形、花菜形、纺锤形以及类似于十字形的多种过渡形态.对最初、过渡和最终形态进行总结,有助于理解微生物作用下的球状碳酸盐矿物形成机理,为识别微生物活动在沉积环境中遗留的痕迹提供更多有用的信息.以往的研究极少涉及Citrobacter freundii诱导碳酸盐矿物的形成.研究结果将丰富微生物促进球状碳酸盐矿化的研究内容.

  1. Development of a Rapid and Accurate Identification Method for Citrobacter Species Isolated from Pork Products Using a Matrix-Assisted Laser-Desorption Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS).

    Science.gov (United States)

    Kwak, Hye-Lim; Han, Sun-Kyung; Park, Sunghoon; Park, Si Hong; Shim, Jae-Yong; Oh, Mihwa; Ricke, Steven C; Kim, Hae-Yeong

    2015-09-01

    Previous detection methods for Citrobacter are considered time consuming and laborious. In this study, we have developed a rapid and accurate detection method for Citrobacter species in pork products, using matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). A total of 35 Citrobacter strains were isolated from 30 pork products and identified by both MALDI-TOF MS and 16S rRNA gene sequencing approaches. All isolates were identified to the species level by the MALDI-TOF MS, while 16S rRNA gene sequencing results could not discriminate them clearly. These results confirmed that MALDI-TOF MS is a more accurate and rapid detection method for the identification of Citrobacter species.

  2. [NiFe]Hydrogenase from Citrobacter sp. S-77 surpasses platinum as an electrode for H2 oxidation reaction.

    Science.gov (United States)

    Matsumoto, Takahiro; Eguchi, Shigenobu; Nakai, Hidetaka; Hibino, Takashi; Yoon, Ki-Seok; Ogo, Seiji

    2014-08-18

    Reported herein is an electrode for dihydrogen (H2) oxidation, and it is based on [NiFe]Hydrogenase from Citrobacter sp. S-77 ([NiFe]S77). It has a 637 times higher mass activity than Pt (calculated based on 1 mg of [NiFe]S77 or Pt) at 50 mV in a hydrogen half-cell. The [NiFe]S77 electrode is also stable in air and, unlike Pt, can be recovered 100 % after poisoning by carbon monoxide. Following characterization of the [NiFe]S77 electrode, a fuel cell comprising a [NiFe]S77 anode and Pt cathode was constructed and shown to have a a higher power density than that achievable by Pt.

  3. Citrobacter freundii infection after acute necrotizing pancreatitis in a patient with a pancreatic pseudocyst: a case report

    Directory of Open Access Journals (Sweden)

    Larino-Noia Jose

    2011-02-01

    Full Text Available Abstract Introduction Infections are the most frequent and severe complications of acute necrotizing pancreatitis with a mortality rate of up to 80 percent. Although experimental and clinical studies suggest that the microbiologic source of pancreatic infection could be enteric, information in this regard is controversial. Case presentation We describe a Citrobacter freundii isolation by endoscopy ultrasound fine needle aspiration in a 80-year-old Caucasian man with pancreatic pseudocyst after acute necrotizing pancreatitis. Conclusion Our case report confirms that this organism can be recovered in patients with a pancreatic pseudocyst. On-site cytology feedback was crucial to the successful outcome of this case as immediate interpretation of the fine needle aspiration sample directed the appropriate cultures and, ultimately, the curative therapy. To the best of our knowledge, this is the first reported case of isolated pancreatic C. freundii diagnosed by endoscopy ultrasound fine needle aspiration.

  4. Malachite green bioremoval by a newly isolated strain Citrobacter sedlakii RI11; enhancement of the treatment by biosurfactant addition.

    Science.gov (United States)

    Mnif, Inès; Fendri, Raouia; Ghribi, Dhouha

    2015-01-01

    Citrobacter sedlackii RI11, isolated from acclimated textile effluent after selective enrichment on synthetic dyes, was assessed for malachite green (MG) biotreatment potency. Results indicate that this bacterium has potential for use in effective treatment of MG contaminated wastewaters under shaking conditions at neutral and alkaline pH value, characteristic of typical textile effluents. Also, the newly isolated strain can tolerate higher doses of dye and decolorize up to 1,000 mg/l of dye. When used as microbial surfactant to enhance MG biodecolorization, Bacillus subtilis SPB1-derived lipopeptide accelerated the decolorization rate and maximized the decolorization efficiency at an optimal concentration of biosurfactant of about 0.075%. Studies ensured that MG removal by this strain could be due to biodegradation and/or adsorption. Results on germination potencies of different seeds using the treated dyes under different conditions favor the use of SPB1 biosurfactant for the treatment of MG.

  5. Aminoglycoside 6′-N-Acetyltransferase Variants of the Ib Type with Altered Substrate Profile in Clinical Isolates of Enterobacter cloacae and Citrobacter freundii

    OpenAIRE

    Casin, Isabelle; Bordon, Florence; Bertin, Philippe; Coutrot, Anne; Podglajen, Isabelle; Brasseur, Robert; Collatz, Ekkehard

    1998-01-01

    Three clinical isolates, Enterobacter cloacae EC1562 and EC1563 and Citrobacter freundii CFr564, displayed an aminoglycoside resistance profile evocative of low-level 6′-N acetyltransferase type II [AAC(6′)-II] production, which conferred reduced susceptibility to gentamicin but not to amikacin or isepamicin. Aminoglycoside acetyltransferase assays suggested the synthesis in the three strains of an AAC(6′) which acetylated amikacin practically as well as it acetylated gentamicin in vitro. Bot...

  6. Molybdenum-containing membrane-bound formate dehydrogenase isolated from Citrobacter sp. S-77 having high stability against oxygen, pH, and temperature.

    Science.gov (United States)

    Nguyen, Nga T; Yatabe, Takeshi; Yoon, Ki-Seok; Ogo, Seiji

    2014-10-01

    Membrane-bound formate dehydrogenase (FDH) was purified to homogeneity from a facultative anaerobic bacterium Citrobacter sp. S-77. The FDH from Citrobacter sp. S-77 (FDHS77) was a monomer with molecular mass of approximately 150 kDa. On SDS-PAGE, the purified FDHS77 showed as three different protein bands with molecular mass of approximately 95, 87, and 32 kDa, respectively. Based on the N-terminal amino acid sequence analysis, the sequence alignments observed for the 87 kDa protein band were identical to that of the large subunit of 95 kDa, indicating that the purified FDHS77 consisted of two subunits; a 95 kDa large subunit and a 32 kDa small subunit. The purified FDHS77 in this purification did not contain a heme b subunit, but the FDHS77 showed significant activity for formate oxidation, determined by the Vmax of 30.4 U/mg using benzyl viologen as an electron acceptor. The EPR and ICP-MS spectra indicate that the FDHS77 is a molybdenum-containing enzyme, displaying a remarkable O2-stability along with thermostability and pH resistance. This is the first report of the purification and characterization of a FDH from Citrobacter species.

  7. Diarrhea-associated biofilm formed by enteroaggregative Escherichia coli and aggregative Citrobacter freundii: a consortium mediated by putative F pili

    Directory of Open Access Journals (Sweden)

    Araújo Ana CG

    2010-02-01

    Full Text Available Abstract Background Enteroaggregative Escherichia coli (EAEC are enteropathogenic strains identified by the aggregative adhesion (AA pattern that share the capability to form biofilms. Citrobacter freundii is classically considered as an indigenous intestinal species that is sporadically associated with diarrhea. Results During an epidemiologic study focusing on infantile diarrhea, aggregative C. freundii (EACF and EAEC strains were concomitantly recovered from a severe case of mucous diarrhea. Thereby, the occurrence of synergic events involving these strains was investigated. Coinfection of HeLa cells with EACF and EAEC strains showed an 8-fold increase in the overall bacterial adhesion compared with single infections (P traA were capable of forming bacterial aggregates only in the presence of EACF. Scanning electronic microscopy analyses revealed that bacterial aggregates as well as enhanced biofilms formed by EACF and traA-positive EAEC were mediated by non-bundle forming, flexible pili. Moreover, mixed biofilms formed by EACF and traA-positive EAEC strains were significantly reduced using nonlethal concentration of zinc, a specific inhibitor of F pili. In addition, EAEC strains isolated from diarrheic children frequently produced single biofilms sensitive to zinc. Conclusions Putative F pili expressed by EAEC strains boosted mixed biofilm formation when in the presence of aggregative C. freundii.

  8. Biochemical characterization of a bifunctional acetaldehyde-alcohol dehydrogenase purified from a facultative anaerobic bacterium Citrobacter sp. S-77.

    Science.gov (United States)

    Tsuji, Kohsei; Yoon, Ki-Seok; Ogo, Seiji

    2016-03-01

    Acetaldehyde-alcohol dehydrogenase (ADHE) is a bifunctional enzyme consisting of two domains of an N-terminal acetaldehyde dehydrogenase (ALDH) and a C-terminal alcohol dehydrogenase (ADH). The enzyme is known to be important in the cellular alcohol metabolism. However, the role of coenzyme A-acylating ADHE responsible for ethanol production from acetyl-CoA remains uncertain. Here, we present the purification and biochemical characterization of an ADHE from Citrobacter sp. S-77 (ADHE(S77)). Interestingly, the ADHE(S77) was unable to be solubilized from membrane with detergents either 1% Triton X-100 or 1% Sulfobetaine 3-12. However, the enzyme was easily dissociated from membrane by high-salt buffers containing either 1.0 M NaCl or (NH(4))(2)SO(4) without detergents. The molecular weight of a native protein was estimated as approximately 400 kDa, consisting of four identical subunits of 96.3 kDa. Based on the specific activity and kinetic analysis, the ADHES77 tended to have catalytic reaction towards acetaldehyde elimination rather than acetaldehyde formation. Our experimental observation suggests that the ADHES77 may play a pivotal role in modulating intracellular acetaldehyde concentration.

  9. Conversion of glycerol to 1,3-propanediol by Citrobacter freundii and Hafnia alvei - newly isolated strains from the Enterobacteriaceae.

    Science.gov (United States)

    Drożdżyńska, Agnieszka; Pawlicka, Joanna; Kubiak, Piotr; Kośmider, Alicja; Pranke, Dorota; Olejnik-Schmidt, Agnieszka; Czaczyk, Katarzyna

    2014-09-25

    In this study, nearly 4000 bacterial strains from the family of Enterobacteriaceae isolated from different environments were screened for ability to convert glycerol to 1,3-propanediol (1,3-PD). The aim of the research was to isolate 1,3-PD producers from the natural environment, identify and characterize the best isolates. Three selective media were tested to usefulness in the isolation of bacteria from the family Enterobacteriaceae. Only, 28% of examined isolates could synthesize 1,3-PD from glycerol. 1,3-PD producing bacteria were identified by API 20E tests and 16S rRNA sequences to be Klebsiella pneumoniae, Klebsiella oxytoca, Citrobacter freundii and Hafnia alvei. It is the first time, when the fermentation glycerol to 1,3-PD by H. alvei was investigated. The selected strains (C. freundii AD119 and H. alvei AD27) were analyzed on a bioreactor scale under constant pH value 7.0 at temperature of 30°C and 37°C. After 40h in batch fermentation, H. alvei AD27 produced 11.3g/L of 1,3-PD at 37°C. For C. freundii AD119, the best results were obtained at temperature of 30°C. After 24h of fermentation, the 1,3-PD concentration reached above 23 g/L of 1,3-PD.

  10. Surfactant-modified fatty acid composition of Citrobacter sp. SA01 and its effect on phenanthrene transmembrane transport.

    Science.gov (United States)

    Li, Feng; Zhu, Lizhong

    2014-07-01

    The effects of the surfactants, Tween 80 and sodium dodecyl benzene sulfonate (SDBS) on a membrane's fatty acid composition and the transmembrane transport of phenanthrene were investigated. The results indicated that both surfactants could modify the composition of fatty acids of Citrobacter sp. Strain SA01 cells, 50 mg L(-1) of both surfactants changed the composition of the fatty acids the most, increasing the amount of unsaturated fatty acids. The comparison of fatty acid profiles with diphenylhexatriene fluorescence anisotropy, a probe for plasma membrane fluidity, suggested that an increased amount of unsaturated fatty acids corresponded to greater membrane fluidity. In addition, increased unsaturated fatty acids promoted phenanthrene to partition from the extracellular matrix to cell debris, which increased reverse partitioning from the cell debris to the cytochylema. The results of this study were expected in that the addition of a surfactant is a simple and effective method for accelerating the rate-limiting step of transmembrane transport of hydrophobic organic compounds (HOCs) in bioremediation.

  11. Alliin is a suicide substrate of Citrobacter freundii methionine γ-lyase: structural bases of inactivation of the enzyme.

    Science.gov (United States)

    Morozova, Elena A; Revtovich, Svetlana V; Anufrieva, Natalya V; Kulikova, Vitalia V; Nikulin, Alexey D; Demidkina, Tatyana V

    2014-11-01

    The interaction of Citrobacter freundii methionine γ-lyase (MGL) and the mutant form in which Cys115 is replaced by Ala (MGL C115A) with the nonprotein amino acid (2R)-2-amino-3-[(S)-prop-2-enylsulfinyl]propanoic acid (alliin) was investigated. It was found that MGL catalyzes the β-elimination reaction of alliin to form 2-propenethiosulfinate (allicin), pyruvate and ammonia. The β-elimination reaction of alliin is followed by the inactivation and modification of SH groups of the wild-type and mutant enzymes. Three-dimensional structures of inactivated wild-type MGL (iMGL wild type) and a C115A mutant form (iMGL C115A) were determined at 1.85 and 1.45 Å resolution and allowed the identification of the SH groups that were oxidized by allicin. On this basis, the mechanism of the inactivation of MGL by alliin, a new suicide substrate of MGL, is proposed.

  12. 柠檬酸杆菌吸附重金属铀的试验研究%Study on Adsorption of Heavy Metal Uranium by Citrobacter freundii

    Institute of Scientific and Technical Information of China (English)

    杨晶

    2009-01-01

    Citrobacter freundii was used to adsorb heavy metal uranium. The influence of pH, strain concentration and initial concentration of uranium on the adsorption of uranium were investigated. The results show that the adsorption efficiency of uranium by Citrobacter freundii increases with the in-crease of pH at the beginning of the adsorption and reaches its maximum at pH of 6 then decreases. The adsorption efficiency increases with the increase of strain concentration, while the adsorption capacity de-creases. The adsorption capacity increases with the increase of the initial concentration of uranium while the adsorption efficiency decreases. The adsorption process of uranium by Citrobacter freundii is in ac-cordance with Langmuir and Freundlich isotherms, and the fitting result of Freundlich isotherm is better.%采用弗氏柠檬酸杆菌吸附重金属铀,考察了pH、菌体浓度和铀离子浓度对吸附效果的影响.结果表明,弗氏柠檬酸杆菌对铀的吸附一开始随pH的增大而增大,当pH值为6时吸附率达到最大,而后降低;吸附率随菌体浓度的增加而增大,吸附量则相反;吸附量随铀起始浓度的增加而增大,而吸附率则降低;吸附过程符合Langmuir和Freundlich等温吸附方程,且后者的拟合效果较前者好.

  13. Degradation characteristics of m-cresol by Citrobacterfarmeri%Citrobacter farmeri降解间甲酚的特性分析

    Institute of Scientific and Technical Information of China (English)

    彭丽花; 董佳

    2011-01-01

    从某焦化厂废水好氧生物处理的污泥中分离出一株能以间甲酚为唯一碳源、能源生长代谢的菌株Citrobacter farmeri.考察了间甲酚在不同初始浓度下Citrobacter farmeri细菌生长动力学,4种等浓度酚类物质的降解先后顺序,分别添加共基质葡萄糖和蛋白胨对低浓度和高浓度间甲酚降解的影响,以及在添加共基质葡萄糖时Citrobacter farmeri降解高浓度间甲酚过程中产生的酶活.结果表明,当间甲酚初始质量浓度低于375 mg/L时,Citrobacter farmeri菌株生长符合一级动力学方程;Citrobacter farmeri降解4种酚类物质的降解顺序依次为苯酚>邻甲酚>间甲酚>萘酚;外加葡萄糖或蛋白胨对质量浓度低于375 mg/L的间甲酚的降解没有影响,但对高于375mg/L的间甲酚降解有明显的促进作用,在最佳葡萄糖添加量为800 mg/L或最佳蛋白胨添加量为640 mg/L时,缩短降解时间分别为30 h和29 h;对酶活的测定发现儿茶酚1,2-双加氧酶和儿茶酚2,3-双加氧酶有明显增大,初步判断Citrobacter farmeri以邻位和间位裂解的途径对间甲酚进行降解.%A bacterium named Citrobacterfarmeri, which utilizes m-cresol as the sole source of carbon and energy, was isolated from the sludge in the aerobic biological wastewater treatment system of a coking plant. The effects of the Citrobacter farmeri bacteria growth kinetics of m-cresol with various initial concentrations, the degradation sequence of the four kinds of phenols with the same concentration, and the separate addition of glucose or peptone on degradation of m-cresol with low or high concentration were studied. The key enzyme activity related to the ring-cleaving during the high-concentration m-cresol degradation by Citrobacter farmeri was measured to analyze the metabolic pathway when added glucose as co-substrate. The results showed that, the Citrobacter farmeri bacterium growth could be described by first-order dynamic equation

  14. Characterization of chromosomal qnrB and ampC alleles in Citrobacter freundii isolates from different origins.

    Science.gov (United States)

    Liao, Xiaoping; Fang, Liangxing; Li, Liang; Sun, Jian; Li, Xingping; Chen, Muya; Deng, Hui; Yang, Qiu'e; Li, Xue; Liu, Yahong

    2015-10-01

    The association of ESBLs (extended-spectrum beta-lactamases)/pAmpCs (plasmid-mediated AmpC β-lactamases) with PMQR (plasmid mediated quinolone resistance) in gram-negative bacteria has been of great concern. The present study was performed to characterize the diversity, gene location, genetic context, and evolution of ampC and qnrB alleles in isolates of Citrobacter freundii. Fifteen isolates of C. freundii were identified from a total of 788 isolates of Enterobacteriaceae derived from humans, animals, animal food products, and the environment between 2010 and 2012. Co-existence of qnrB/ΔqnrB with ampC was detected in all C. freundii isolates. Both ampC and qnrB genes were found to be located on the chromosome, but were distantly separated on the chromosome. Seven and six novel alleles were discovered for the 10 ampC and qnrB variants detected in this study, respectively. Phylogenetic analysis showed that the new alleles differed a little from the variants of ampC/qnrB previously described in this genus. The genetic context surrounding ampC genes was AmpR-AmpC-Blc-SugE. However, five different genetic contexts surrounding qnrB/ΔqnrB genes were observed, but they occurred in all cases between the pspF and sapA genes. Additionally, cloning experiments showed that the regions containing different qnrB alleles, even with different genetic contexts, contributed to the reduction of quinolone susceptibility. Our results showed that the chromosomal ampC and qnrB alleles are closely related to C. freundii. However, unlike ampC, qnrB alleles seemed to be related to the genetic contexts surrounding them. The evolution of these two genes in C. freundii isolates might be through different pathways.

  15. Fermentative hydrogen production by Clostridium butyricum CWBI1009 and Citrobacter freundii CWBI952 in pure and mixed cultures

    Directory of Open Access Journals (Sweden)

    Beckers, L.

    2010-01-01

    Full Text Available This paper investigates the biohydrogen production by two mesophilic strains, a strict anaerobe (Clostridium butyricum CWBI1009 and a facultative anaerobe (Citrobacter freundii CWBI952. They were cultured in pure and mixed cultures in serum bottles with five different carbon sources. The hydrogen yields of pure C. freundii cultures ranged from 0.09 molH2.molhexose-1 (with sucrose to 0.24 molH2.molhexose-1 (with glucose. Higher yields were obtained by the pure cultures of Cl. butyricum ranging from 0.44 molH2.molhexose-1 (with sucrose to 0.69 molH2.molhexose-1 (with lactose. This strain also fermented starch whereas C. freundii did not. However, it consumed the other substrates faster and produced hydrogen earlier than Cl. butyricum. This ability has been used to promote the growth conditions of Cl. butyricum in co-culture with C. freundii, since Cl. butyricum is extremely sensitive to the presence of oxygen which strongly inhibits H2 production. This approach could avoid the addition of any expensive reducing agents in the culture media such as L-cysteine since C. freundii consumes the residual oxygen. Thereafter, co-cultures with glucose and starch were investigated: hydrogen yields decreased from 0.53 molH2.molhexose-1 for pure Cl. butyricum cultures to 0.38 molH2.molhexose-1 for mixed culture with glucose but slightly increased with starch (respectively 0.69 and 0.73 molH2.molhexose-1. After 48 h of fermentation, metabolites analysis confirmed with microbial observation, revealed that the cell concentration of C. freundii dramatically decreased or was strongly inhibited by the development of Cl. butyricum.

  16. Use of WGS data for investigation of a long-term NDM-1-producing Citrobacter freundii outbreak and secondary in vivo spread of blaNDM-1 to Escherichia coli, Klebsiella pneumoniae and Klebsiella oxytoca

    DEFF Research Database (Denmark)

    Hammerum, Anette M; Hansen, Frank; Nielsen, Hans Linde;

    2016-01-01

    OBJECTIVES: An outbreak of NDM-1-producing Citrobacter freundii and possible secondary in vivo spread of blaNDM-1 to other Enterobacteriaceae were investigated. METHODS: From October 2012 to March 2015, meropenem-resistant Enterobacteriaceae were detected in 45 samples from seven patients...

  17. 潜在致病性的弗氏枸橼酸杆菌的筛查%Screening of potential pathogenic Citrobacter freundii

    Institute of Scientific and Technical Information of China (English)

    刘丽云; 夏胜利; 孙晖

    2015-01-01

    目的 筛查具有潜在致病性的弗氏枸橼酸杆菌.方法 对从河南省睢县分离到的36株弗氏枸橼酸杆菌进行黏附HEp-2细胞的检测,以及与HEp-2细胞(MOI:100)作用10 h后的乳酸脱氢酶(LDH)释放情况分析.同时比较弗氏枸橼酸杆菌CF74(Citrobacter freundii 74)、CF72(Citrobacter freundii 72)、肠聚集性大肠埃希菌(EnteroaggregativeE.coli,EAEC)、肠致病性大肠埃希菌(Enteropathogenic E.coli,EPEC)2348/69和HB101的黏附和细胞毒性差异.结果 16株弗氏枸橼酸杆菌几乎没有黏附性,黏附指数<1;18株弗氏枸橼酸杆菌具有中等强度的黏附性,黏附指数<100;2株弗氏枸橼酸杆菌CF74和CF65(Citrobacter freundii 65)具有强的黏附性.与HEp-2细胞作用10 h后,除了CF74(24.4%),其余的35株弗氏枸橼酸杆菌具有低的LDH释放量,LDH释放量与阴性对照HB101 (5.02%)相似.说明除了CF74,其余的弗氏枸橼酸杆菌不具有细胞毒性.CF74具有和EAEC042一样的聚集性黏附类型,并且CF74引起的LDH释放率明显高于CF72、2348/69和HB101(P<0.01)而低于EAEC17-2.结论 作为潜在的致病菌,CF74具有强的黏附性和细胞毒性.

  18. Cancer genomics

    DEFF Research Database (Denmark)

    Norrild, Bodil; Guldberg, Per; Ralfkiær, Elisabeth Methner

    2007-01-01

    Almost all cells in the human body contain a complete copy of the genome with an estimated number of 25,000 genes. The sequences of these genes make up about three percent of the genome and comprise the inherited set of genetic information. The genome also contains information that determines whe...

  19. 弗劳地枸橼酸杆菌引起的猕猴腹泻%Identification of Citrobacter freundii Caused Diarrhea in Rhesus Monkey

    Institute of Scientific and Technical Information of China (English)

    周勤; 郭光远

    2004-01-01

    对从腹泻猕猴脓血便中分离的一株细菌,经ATB细菌分析仪,选用ID32E肠杆菌测试条鉴定为弗劳地枸橼酸杆菌(Citrobacter freundii),id%=99.9.用K-B纸片法做药敏试验,结果表明,该菌对诺氟沙星、环丙沙星、头孢噻肟、头孢曲松、头孢他定、氯霉素敏感.对庆大霉素、头孢拉定、痢特灵等十几种抗生素耐药.总之,在做腹泻病猴粪便培养时,应重视弗劳地枸橼酸菌的检测.

  20. A large family of antivirulence regulators modulates the effects of transcriptional activators in Gram-negative pathogenic bacteria.

    Directory of Open Access Journals (Sweden)

    Araceli E Santiago

    2014-05-01

    Full Text Available We have reported that transcription of a hypothetical small open reading frame (orf60 in enteroaggregative E. coli (EAEC strain 042 is impaired after mutation of aggR, which encodes a global virulence activator. We have also reported that the cryptic orf60 locus was linked to protection against EAEC diarrhea in two epidemiologic studies. Here, we report that the orf60 product acts as a negative regulator of aggR itself. The orf60 protein product lacks homology to known repressors, but displays 44-100% similarity to at least fifty previously undescribed small (<10 kDa hypothetical proteins found in many gram negative pathogen genomes. Expression of orf60 homologs from enterotoxigenic E. coli (ETEC repressed the expression of the AraC-transcriptional ETEC regulator CfaD/Rns and its regulon in ETEC strain H10407. Complementation in trans of EAEC 042orf60 by orf60 homologs from ETEC and the mouse pathogen Citrobacter rodentium resulted in dramatic suppression of aggR. A C. rodentium orf60 homolog mutant showed increased levels of activator RegA and increased colonization of the adult mouse. We propose the name Aar (AggR-activated regulator for the clinically and epidemiologically important orf60 product in EAEC, and postulate the existence of a large family of homologs among pathogenic Enterobacteriaceae and Pasteurellaceae. We propose the name ANR (AraC Negative Regulators for this family.

  1. Box counting method in recording, processing and evaluation of genomic signals

    Directory of Open Access Journals (Sweden)

    Martin Valla*

    2010-12-01

    Full Text Available Fractals are geometrical shapes with noninteger dimension andinvariance against change of scale factor. For each geometricalshape, a single parameter - dimension - can be calculated. Forcalculation, Box Counting Method (BCM was chosen.Determination of dimension on one level of resolution is notsufficient, it is necessary to subsequently process it and determine multifractal coefficient. Aim of our interest consists in analysis of images obtained from a linear sequence of DNA code. For analysis itself, sequences of Homo sapiens and Citrobacter youngae were chosen. Results of calculation are fractal coefficients derived from dimensions of generated structures. This result enables to introduce criterion for sequences determination. Graphical outputs may bealso represented as multidimensional alternative transformation of linearly recorded genomic signal. Algorithms were developed in computational environment MATLAB. Data were downloaded from a public database EMBL (ESI and GenBank (NCBI.

  2. Identification of Citrobacter freundii from Ornamental Carp ( Cyprinus carpio L. )%锦鲤弗氏柠檬酸杆菌的鉴定

    Institute of Scientific and Technical Information of China (English)

    陈翠珍; 房海; 葛慕湘; 王秀云

    2011-01-01

    对从病死锦鲤(cyprinuscarpioL.)肝组织中分离的2株菌(编号:HC050630B-1,HC050630B-2)进行了形态特征、主要理化特性、对健康鲤鱼的致病作用、药物敏感性等方面的检验;同时测定了HCOS0630B-1株菌的16SrRNA基因序列,构建了系统发育树。结果表明,2株被检菌为弗氏柠檬酸杆菌(Citrobacter加吼蒯),对健康鲤鱼有致病作用;所测菌株的16SrRNA基因序列长度1458bp,在GenBank中登录号为EF669481,该菌株16SrRNA基因序列与GenBank数据库中柠檬酸杆菌属细菌的16SrRNA基因序列同源性在99%;药敏试验结果显示,对供试的头孢噻肟等21种药物呈现高度敏感或敏感,对头孢唑啉等5种呈低度敏感,对四环素等11种耐药。%Two strains ( HC050630B-1 ,HC050630B-2) isolated from the liver of diseased ( or dead) ornamen- tal carp were examined,including their morphological characteristics,physiological and biochemical character- istics ,pathogenicity to healthy carp and antibiotic sensitivity. In addition,the 16S rRNA gene of HC050630B-1 were sequenced,and molecular phylogenetic tree was constructed. The results showed that the two examined strains were identified as Citrobacter freundii, and had strong pathogenicity to healthy carp. The length of the 16S rRNA gene sequence of examined strain is 1 458 bp. Its database accession numbers in NCBI is EF669481 ,and the similarity of the 16S rRNA gene sequence of examined strain with the 16S rRNA gene of Citrobacter from GenBank database is 99%. The antibiotic sensitivity using 37 antimicrobial agents showed that isolates were high sensitive or sensitive to 21 agents including cefotaxime, slight sensitive to 5 agents including cefazolin, and resistant to 11 agents including tetrecycline.

  3. Effect of surfactant-induced cell surface modifications on electron transport system and catechol 1,2-dioxygenase activities and phenanthrene biodegradation by Citrobacter sp. SA01.

    Science.gov (United States)

    Li, Feng; Zhu, Lizhong

    2012-11-01

    In order to better understand how surfactants affect biodegradation of hydrophobic organic compounds (HOCs), Tween 80 and sodium dodecyl benzene sulfonate (SDBS), were selected to investigate effects on cell surface hydrophobicity (CSH), electron transport system (ETS) activities and phenanthrene biodegradation by Citrobacter sp. SA01. Tween 80 and SDBS increased CSH by 19.8-25.2%, ETS activities by 352.1-376.0μmol/gmin, catechol 1,2-dioxygenase (C12) activities by 50.8-52.7U/L, and phenanthrene biodegradation by 8.9-17.2% separately in the presence of 50mg/L of surfactants as compared to in their absence. Lipopolysaccharide (LPS) release was 334.7μg/mg in the presence of both surfactants whereas in their absence only 8.6-44.4μg/mg of LPS was released. Thus, enhanced LPS release probably increased ETS and C12 activities as well as phenanthrene biodegradation by increasing CSH. The results demonstrate that surfactant-enhanced CSH provides a simple, yet effective strategy for field applications of surfactant-enhanced bioremediation of HOCs.

  4. Citrobacter amalonaticus phytase on the cell surface of Pichia pastoris exhibits high pH stability as a promising potential feed supplement.

    Science.gov (United States)

    Li, Cheng; Lin, Ying; Huang, Yuanyuan; Liu, Xiaoxiao; Liang, Shuli

    2014-01-01

    Phytase expressed and anchored on the cell surface of Pichia pastoris avoids the expensive and time-consuming steps of protein purification and separation. Furthermore, yeast cells with anchored phytase can be used as a whole-cell biocatalyst. In this study, the phytase gene of Citrobacter amalonaticus was fused with the Pichia pastoris glycosylphosphatidylinositol (GPI)-anchored glycoprotein homologue GCW61. Phytase exposed on the cell surface exhibits a high activity of 6413.5 U/g, with an optimal temperature of 60°C. In contrast to secreted phytase, which has an optimal pH of 5.0, phytase presented on the cell surface is characterized by an optimal pH of 3.0. Moreover, our data demonstrate that phytase anchored on the cell surface exhibits higher pH stability than its secreted counterpart. Interestingly, our in vitro digestion experiments demonstrate that phytase attached to the cell surface is a more efficient enzyme than secreted phytase.

  5. 花鳗鲡病原菌弗氏柠檬酸杆菌的鉴定%Identification of Pathogenic Citrobacter freundii Isolated from Anguilla marmorata

    Institute of Scientific and Technical Information of China (English)

    杨方园; 关瑞章; 李忠琴; 于海振; 李秋云

    2013-01-01

    首次报道了从养殖花鳗鲡(Anguilla marmorata)肝脏中分离得到优势菌株AMRB6,经人工腹腔注射感染健康花鳗鲡试验,结果证实该菌有致病作用,其半数致死量LD50为3.2×107 CFU/mL.结合菌体形态特征、常规生理生化鉴定和Biolog自动微生物鉴定系统鉴定,以及16S rRNA序列扩增结果,表明该菌为弗氏柠檬酸杆菌(Citrobacter freundii).30种药物药敏试验结果表明,该菌株对左氧氟沙星、诺氟沙星、庆大霉素、卡那霉素等14种药物高度敏感.

  6. Listeria Genomics

    Science.gov (United States)

    Cabanes, Didier; Sousa, Sandra; Cossart, Pascale

    The opportunistic intracellular foodborne pathogen Listeria monocytogenes has become a paradigm for the study of host-pathogen interactions and bacterial adaptation to mammalian hosts. Analysis of L. monocytogenes infection has provided considerable insight into how bacteria invade cells, move intracellularly, and disseminate in tissues, as well as tools to address fundamental processes in cell biology. Moreover, the vast amount of knowledge that has been gathered through in-depth comparative genomic analyses and in vivo studies makes L. monocytogenes one of the most well-studied bacterial pathogens. This chapter provides an overview of progress in the exploration of genomic, transcriptomic, and proteomic data in Listeria spp. to understand genome evolution and diversity, as well as physiological aspects of metabolism used by bacteria when growing in diverse environments, in particular in infected hosts.

  7. Cephalopod genomics

    DEFF Research Database (Denmark)

    Albertin, Caroline B.; Bonnaud, Laure; Brown, C. Titus;

    2012-01-01

    The Cephalopod Sequencing Consortium (CephSeq Consortium) was established at a NESCent Catalysis Group Meeting, ``Paths to Cephalopod Genomics-Strategies, Choices, Organization,'' held in Durham, North Carolina, USA on May 24-27, 2012. Twenty-eight participants representing nine countries (Austria...... active in sequencing, assembling and annotating genomes, agreed on a set of cephalopod species of particular importance for initial sequencing and developed strategies and an organization (CephSeq Consortium) to promote this sequencing. The conclusions and recommendations of this meeting are described...

  8. Genome Sequencing

    DEFF Research Database (Denmark)

    Sato, Shusei; Andersen, Stig Uggerhøj

    2014-01-01

    The current Lotus japonicus reference genome sequence is based on a hybrid assembly of Sanger TAC/BAC, Sanger shotgun and Illumina shotgun sequencing data generated from the Miyakojima-MG20 accession. It covers nearly all expressed L. japonicus genes and has been annotated mainly based on transcr......The current Lotus japonicus reference genome sequence is based on a hybrid assembly of Sanger TAC/BAC, Sanger shotgun and Illumina shotgun sequencing data generated from the Miyakojima-MG20 accession. It covers nearly all expressed L. japonicus genes and has been annotated mainly based...

  9. Evaluative profiling of arsenic sensing and regulatory systems in the human microbiome project genomes.

    Science.gov (United States)

    Isokpehi, Raphael D; Udensi, Udensi K; Simmons, Shaneka S; Hollman, Antoinesha L; Cain, Antia E; Olofinsae, Samson A; Hassan, Oluwabukola A; Kashim, Zainab A; Enejoh, Ojochenemi A; Fasesan, Deborah E; Nashiru, Oyekanmi

    2014-01-01

    The influence of environmental chemicals including arsenic, a type 1 carcinogen, on the composition and function of the human-associated microbiota is of significance in human health and disease. We have developed a suite of bioinformatics and visual analytics methods to evaluate the availability (presence or absence) and abundance of functional annotations in a microbial genome for seven Pfam protein families: As(III)-responsive transcriptional repressor (ArsR), anion-transporting ATPase (ArsA), arsenical pump membrane protein (ArsB), arsenate reductase (ArsC), arsenical resistance operon transacting repressor (ArsD), water/glycerol transport protein (aquaporins), and universal stress protein (USP). These genes encode function for sensing and/or regulating arsenic content in the bacterial cell. The evaluative profiling strategy was applied to 3,274 genomes from which 62 genomes from 18 genera were identified to contain genes for the seven protein families. Our list included 12 genomes in the Human Microbiome Project (HMP) from the following genera: Citrobacter, Escherichia, Lactobacillus, Providencia, Rhodococcus, and Staphylococcus. Gene neighborhood analysis of the arsenic resistance operon in the genome of Bacteroides thetaiotaomicron VPI-5482, a human gut symbiont, revealed the adjacent arrangement of genes for arsenite binding/transfer (ArsD) and cytochrome c biosynthesis (DsbD_2). Visual analytics facilitated evaluation of protein annotations in 367 genomes in the phylum Bacteroidetes identified multiple genomes in which genes for ArsD and DsbD_2 were adjacently arranged. Cytochrome c, produced by a posttranslational process, consists of heme-containing proteins important for cellular energy production and signaling. Further research is desired to elucidate arsenic resistance and arsenic-mediated cellular energy production in the Bacteroidetes.

  10. 一株大凉疣螈肠道弗氏柠檬酸杆菌的分离及其药敏试验%Isolation and Susceptibility Test of an Intestinal Citrobacter freundii from Tylototriton taliangensis

    Institute of Scientific and Technical Information of China (English)

    李蓓; 邹立扣; 罗燕

    2011-01-01

    首次从大凉疣螈(Tylototritoa taliangemsis)肠道分离获得弗氏柠稼酸杆菌(Citrobacter freundii),利用分子生物学方法对其16S rDNA进行了扩增测序,并与GenBank中已有的有关序列进行比较,进行了系统发育分析.测序结果表明,16S rDNA与GenBank中序列同源率在98%~99%,分离的菌株与GU126681(C.freundii MRB0903)处于同一分支中;序列同源性及系统发育树表明,此菌为弗氏柠檬酸杆菌;药敏试验表明.弗氏柠檬酸杆菌对氨苄西林及头孢噻吩中介,对其余药物均敏感.%A Citrobacter freundii was isolated from the intestinal tact of Tylototriton taliangensis ,and its 16S rDNA was amplified and sequenced by the molecular biology method,and then the 16S rDNA was compared with other sequences in Genbank to conduct a phylogenetic analysis. The results indicated that the 16S rDNA sequence of Citrobacter freundii showed 98% -99% homogeny with those in the GenBank.and belonged to the same branch with GU126681 (C.freundii MRB0903). As shown by the sequence homology and phylogenetic tree,the bacterium was C. Freun-dii,which was medium sensitive to ampicillin and cephalothin,and sensitive to other biotics.

  11. Ancient genomics

    DEFF Research Database (Denmark)

    Der Sarkissian, Clio; Allentoft, Morten Erik; Avila Arcos, Maria del Carmen;

    2015-01-01

    , archaic hominins, ancient pathogens and megafaunal species. Those have revealed important functional and phenotypic information, as well as unexpected adaptation, migration and admixture patterns. As such, the field of aDNA has entered the new era of genomics and has provided valuable information when...

  12. Herbarium genomics

    DEFF Research Database (Denmark)

    Bakker, Freek T.; Lei, Di; Yu, Jiaying;

    2016-01-01

    Herbarium genomics is proving promising as next-generation sequencing approaches are well suited to deal with the usually fragmented nature of archival DNA. We show that routine assembly of partial plastome sequences from herbarium specimens is feasible, from total DNA extracts and with specimens...

  13. Optimization of culture conditions for biological hydrogen production by Citrobacter freundii CWBI952 in batch, sequenced-batch and semicontinuous operating mode

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, Christopher; Hiligsmann, Serge; Beckers, Laurent; Masset, Julien; Thonart, Philippe [Walloon Centre of Industrial Biology, Bd du Rectorat, 29, B.40 - P.70, B-4000 Liege (Belgium); Wilmotte, Annick [Center for Protein Engineering, Institute of Chemistry, B.6-P.14, B-4000 Liege (Belgium)

    2010-02-15

    Investigations were carried out to determine the effect of the pH, the nitrogen source, iron and the dilution rate (h{sup -1}) on fermentative hydrogen production from glucose by the newly isolated strain Citrobacter freundii CWBI952. The hydrogen production rate (HPR), hydrogen yield, biomass and soluble metabolites were monitored at 30 C in 100 mL serum bottles and in a 2.3 L bioreactor operated in batch, sequenced-batch and semicontinuous mode. The results indicate that hydrogen production activity, formate biosynthesis and glucose intake rates are very sensitive to the culture pH, and that additional formate bioconversion and production of hydrogen with lower biomass yields can be obtained at pH 5.9. In a further series of cultures casein peptone was replaced by (NH{sub 4}){sub 2}SO{sub 4}, a low cost alternative nitrogen source. The ammonia-based substitute was found to be suitable for H{sub 2} production when a concentration of 0.045 g/L FeSO{sub 4} was provided. Optimal overall performances (ca. an HPR of 33.2 mL H{sub 2}/L h and a yield of 0.83mol{sub H{sub 2}}/mol{sub glucose}) were obtained in the semicontinuous culture applying the previously optimized parameters for pH, nitrogen, and iron with a dilution rate of 0.012 h{sup -1} and degassing of biogas by N{sub 2} at a 28 mL/min flow rate. (author)

  14. Mechanistic deductions from kinetic isotope effects and pH studies of pyridoxal phosphate dependent carbon-carbon lyases: Erwinia herbicola and Citrobacter freundii tyrosine phenol-lyase

    International Nuclear Information System (INIS)

    The pH dependence of the kinetic parameters and primary deuterium isotope effects have been determined for tyrosine phenol-lyase from both Erwinia herbicola and Citrobacter freundii. The primary deuterium isotope effects indicate that proton abstraction from the 2-position of the substrate is partially rate-limiting for both enzymes. The C. freundii enzyme primary deuterium isotope effects [DV = 3.5 and D(V/Ktyr) = 2.5] are pH independent, indicating that tyrosine is not sticky (i.e., does not dissociate slower than it reacts to give products). Since Vmax for both tyrosine and the alternate substrate S-methyl-L-cysteine is also pH independent, substrate binds only to the correctly protonated form of the enzyme. For the E. herbicola enzyme, both Vmax and V/K for tyrosine or S-methyl-L-cysteine are pH dependent, as well as both DV and D(V/Ktyr). Thus, while both the protonated and unprotonated enzyme can bind substrate, and may be interconverted directly, only the unprotonated Michaelis complex is catalytically competent. At pH 9.5, DV = 2.5 and D(V/Ktyr) = 1.5. However, at pH 6.4 the isotope effect on both parameters is equal to 4.1. From these data, the forward commitment factor (cf = 5.2) and catalytic ratio (cvf = 1.1) for tyrosine and S-methyl-L-cysteine (cf = 2.2, cvf = 24) are calculated. Also, the Michaelis complex partition ratio (cf/cvf) for substrate and products is calculated to be 4.7 for tyrosine and 0.1 for S-methyl-L-cysteine

  15. Mechanistic deductions from kinetic isotope effects and pH studies of pyridoxal phosphate dependent carbon-carbon lyases: Erwinia herbicola and Citrobacter freundii tyrosine phenol-lyase

    Energy Technology Data Exchange (ETDEWEB)

    Kiick, D.M.; Phillips, R.S.

    1988-09-20

    The pH dependence of the kinetic parameters and primary deuterium isotope effects have been determined for tyrosine phenol-lyase from both Erwinia herbicola and Citrobacter freundii. The primary deuterium isotope effects indicate that proton abstraction from the 2-position of the substrate is partially rate-limiting for both enzymes. The C. freundii enzyme primary deuterium isotope effects (DV = 3.5 and D(V/Ktyr) = 2.5) are pH independent, indicating that tyrosine is not sticky (i.e., does not dissociate slower than it reacts to give products). Since Vmax for both tyrosine and the alternate substrate S-methyl-L-cysteine is also pH independent, substrate binds only to the correctly protonated form of the enzyme. For the E. herbicola enzyme, both Vmax and V/K for tyrosine or S-methyl-L-cysteine are pH dependent, as well as both DV and D(V/Ktyr). Thus, while both the protonated and unprotonated enzyme can bind substrate, and may be interconverted directly, only the unprotonated Michaelis complex is catalytically competent. At pH 9.5, DV = 2.5 and D(V/Ktyr) = 1.5. However, at pH 6.4 the isotope effect on both parameters is equal to 4.1. From these data, the forward commitment factor (cf = 5.2) and catalytic ratio (cvf = 1.1) for tyrosine and S-methyl-L-cysteine (cf = 2.2, cvf = 24) are calculated. Also, the Michaelis complex partition ratio (cf/cvf) for substrate and products is calculated to be 4.7 for tyrosine and 0.1 for S-methyl-L-cysteine.

  16. Genome cartography: charting the apicomplexan genome.

    Science.gov (United States)

    Kissinger, Jessica C; DeBarry, Jeremy

    2011-08-01

    Genes reside in particular genomic contexts that can be mapped at many levels. Historically, 'genetic maps' were used primarily to locate genes. Recent technological advances in the determination of genome sequences have made the analysis and comparison of whole genomes possible and increasingly tractable. What do we see if we shift our focus from gene content (the 'inventory' of genes contained within a genome) to the composition and organization of a genome? This review examines what has been learned about the evolution of the apicomplexan genome as well as the significance and impact of genomic location on our understanding of the eukaryotic genome and parasite biology.

  17. Citrus Genomics

    OpenAIRE

    Talon, Manuel; Gmitter, Fred G.Jr.

    2008-01-01

    Citrus is one of the most widespread fruit crops globally, with great economic and health value. It is among the most difficult plants to improve through traditional breeding approaches. Currently, there is risk of devastation by diseases threatening to limit production and future availability to the human population. As technologies rapidly advance in genomic science, they are quickly adapted to address the biological challenges of the citrus plant system and the world's industries. The hist...

  18. The function genomics study

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ Genomics is a biology term appeared ten years ago, used to describe the researches of genomic mapping, sequencing, and structure analysis, etc. Genomics, the first journal for publishing papers on genomics research was born in 1986. In the past decade, the concept of genomics has been widely accepted by scientists who are engaging in biology research. Meanwhile, the research scope of genomics has been extended continuously, from simple gene mapping and sequencing to function genomics study. To reflect the change, genomics is divided into two parts now, the structure genomics and the function genomics.

  19. Visualization for genomics: the Microbial Genome Viewer.

    NARCIS (Netherlands)

    Kerkhoven, R.; Enckevort, F.H.J. van; Boekhorst, J.; Molenaar, D.; Siezen, R.J.

    2004-01-01

    SUMMARY: A Web-based visualization tool, the Microbial Genome Viewer, is presented that allows the user to combine complex genomic data in a highly interactive way. This Web tool enables the interactive generation of chromosome wheels and linear genome maps from genome annotation data stored in a My

  20. 156株弗氏柠檬酸杆菌感染的分布与耐药性分析%Distribution and drug resistance of 156 strains of citrobacter freundii

    Institute of Scientific and Technical Information of China (English)

    刘广义

    2011-01-01

    OBJECTIVE To understand the distribution and drug resistance of citrobacter freundii, to provide a reasonable basis for clinicians to use anti-infective therapy. METHODS Totally 156 strains of Citrobacter freundii from patients from Oct 2008 to May 2010 were analyzed, the component ratio and the isolation rate from various department were calculated by referring to the National Clinical Laboratory Operation Rules, as well as the drug sensitivity testing was performed by K-B methods. RESULTS Of 156 strains of isolated citrobacter freundii, the isolates from department of respiratory medicine accounted for 39.1%, from department of neurology 15.4 %,from intensive care unit was 12.2% ; the main clinical specimens were collected from the sputum, the liquor purisand the urine, accounting for 60. 3%, 21. 2% and 7. 1%, respectively. Of 447 strains of detected pathogenic bacteria, there were 156 strains of citrobacter freundii, accounting for 34.9%; drug resistance rates of CFR to ampicillin and cefazolin were 100. 0% and 91.0%, which could cause multiple sites infection. CONCLUSION Hospital should attach importance to the monitoring and the controlling of multidrug-resistant citrobacter freundii and prevent the outbreak and epidemic of nosocomial infections.%目的 了解医院临床标本分离的弗氏柠檬酸杆菌(CFR)检出分布规律及耐药性特点,为临床医师合理抗感染治疗提供依据.方法 回顾性分析2008年1月-2010年5月,住院患者送检标本中分离的156株CFR,计算其构成比、科室分离率,鉴定按进行;药物敏感性试验采用CLSI推荐的K-B法.结果 分离的156株CFR中,呼吸内科检出占39.1%,神经内科占15.4%,综合ICU占12.2%;主要标本来源于痰液、脓液、尿液,分别占总数的60.3%、21.2%、7.1%;病原菌检出447株,检出CFR 156株,占34.9%;CFR对氨苄西林、头孢唑林的耐药性较强,耐药率分别为100.0%、91.0%,可引起多部位感染.结论应重视对多药

  1. An Analysis of the Effects of Vancomycin and/or Vancomycin-Resistant Citrobacter freundii Exposure on the Microbial Community Structure in Soil.

    Science.gov (United States)

    Cycoń, Mariusz; Borymski, Sławomir; Orlewska, Kamila; Wąsik, Tomasz J; Piotrowska-Seget, Zofia

    2016-01-01

    The occurrence of antibiotics and antibiotic resistance genes in the environment has become a subject of growing concern. The extensive use of vancomycin and other pharmaceuticals may alter the biodiversity of soil microbial communities and select antibiotic-resistant bacteria. Therefore, the purpose of the study was to evaluate the impact of vancomycin and/or vancomycin-resistant Citrobacter freundii on soil microbial communities using the denaturing gradient gel electrophoresis (DGGE) and the phospholipid fatty acid (PLFA) approaches. The experiment had a completely randomized block design with the following treatments: control soil (C), soil with vancomycin (1 mg/kg soil-VA1), soil with vancomycin (10 mg/kg soil-VA10), soil with C. freundii (Cit), soil with vancomycin (1 mg/kg soil) and C. freundii (VA1+Cit), and soil with vancomycin (10 mg/kg soil) and C. freundii (VA10+Cit). A bacterial strain resistant to vancomycin was isolated from raw sewage collected from the municipal sewage treatment plant. The obtained results indicated that the antibiotic and/or the bacterial strain exerted a selective pressure that resulted in qualitative and quantitative changes in the population of soil microorganisms. However, a multivariate analysis showed that the genetic and structural diversity of the soil microbial community was primarily affected by the incubation time and to a lesser extent by the antibiotic and introduced bacteria. DGGE analysis clearly showed that certain species within the bacterial community were sensitive to vancomycin as was evidenced by a decrease in the values of S (richness) and H (Shannon-Wiener) indices. Moreover, a PLFA method-based analysis revealed alterations in the structure of the soil microbial community as indicated by changes in the biomass of the PLFA biomarkers specific for Gram-positive and Gram-negative bacteria as well as fungi. The changes observed in the community of soil microorganisms may decrease the rate of microbial

  2. 中华绒螯蟹病原弗氏柠檬酸杆菌的鉴定%Identification of Citrobacter freundii isolated from crab (Eriocheir sinensis)

    Institute of Scientific and Technical Information of China (English)

    陈翠珍; 张晓君; 房海; 巩元芳; 葛慕湘

    2006-01-01

    目的对从一起自然发病的病(死)中华绒螯蟹(Eriocheir sinensis H.Milne-Edwards)肝胰腺中,所分离做纯培养的6株(HQ010516B-1至HQ010516B-6)菌,进行在主要生物学性状、感染试验的致病作用、对抗菌类药物的敏感性等方面的检验,旨在明确分离菌的种类、病原学意义及耐药特征等.方法在发病情况及主要病变检验的基础上,以6只病(死)蟹的肝胰腺为材料做细菌分离与纯培养,对纯培养菌做形态特征、理化特性、16S rRNA基因序列测定及系统发育学分析等方面较系统的鉴定,主要依据(1994)并结合系统发育特征做菌种归类判定;以3×108CFU/ml的菌悬液,对健康蟹做感染试验,测定相应的致病作用;用琼脂扩散(K-B)法做对常用抗菌类药物的敏感性测定,以抑菌圈直径作为敏感与耐药的判定指标.结果分离做纯培养的6株菌为同种的弗氏柠檬酸杆菌(Citrobacter freundii),对供试健康蟹有致病性,对供试37种抗菌类药物中的头孢噻肟等22种药物呈敏感或高度敏感、对四环素等5种呈低度敏感、对青霉素G等10种耐药.结论所检出的弗氏柠檬酸杆菌,构成了所检中华绒螯蟹病例的病原菌之一,对供试抗菌类药物未表现出敏感与耐药的明显株间差异性.

  3. Characterization of extended-spectrum β-lactamase (ESBL)-producing Klebsiella, Enterobacter, and Citrobacter obtained in environmental samples of a Tunisian hospital.

    Science.gov (United States)

    Dziri, Raoudha; Klibi, Naouel; Alonso, Carla Andrea; Said, Leila Ben; Bellaaj, Ridha; Slama, Karim Ben; Boudabous, Abdellatif; Torres, Carmen

    2016-10-01

    The assessment of the hospital environment as a reservoir of ESBL-producing Enterobacteriaceae in Tunisian hospitals is scarcely analyzed, except for Escherichia coli. The aim of this study was to evaluate the presence of ESBL-producing non-E. coli Enterobacteriaceae (ESBL-EbNoEc) in 300 samples of abiotic surfaces and the hands of patients and staff of a Tunisian Hospital, and to characterize the ESBL genes of the recovered isolates. ESBL-EbNoEc were recovered in 28 of 300 (9.3%) analyzed samples and were identified as Klebsiella pneumoniae (n= 11), Enterobacter cloacae (n=11), Citrobacter freundii (n=4) and Klebsiella oxytoca (n=2). The bla genes identified by PCR and sequencing among the strains were as follows: 11 K.pneumoniae strains [blaCTX-M-15+ blaTEM-1+ blaSHV-11 (n=6); blaCTX-M-15+ blaTEM-1+ blaSHV-28 (n=3); blaCTX-M-15+ blaTEM-1+ blaSHV-1 (n=2)], 11 E. cloacae strains [blaCTX-M-15 (n=6); blaCTX-M-15+ blaTEM-1b (n=2); blaCTX-M-15+ blaTEM-1b+ blaOXA-1 (n=1);blaCTX-M-15+ blaOXA-1 (n=1);blaSHV-12 (n=1)], 4 C. freundii strains [blaCTX-M-15] and 2 K. oxytoca strains [blaCTX-M-15 (n=1); blaSHV-12 (n=1)]. The ISEcp1 and orf477 sequences were identified upstream and downstream of the blaCTX-M-15 gene, respectively, in 3 K. pneumoniae and 3 E. cloacae isolates. The PFGE analysis demonstrated three unrelated pulsotypes in K. pneumoniae strains and five pulsotypes in E. cloacae. The uncontrolled dissemination of ESBL-producing bacteria, even in the hospital environment, has become a real problem and new strategies and hygienic rules are needed to stop this bacterial dissemination. PMID:27492133

  4. Whole Genome Sequencing

    Science.gov (United States)

    ... you want to learn. Search form Search Whole Genome Sequencing You are here Home Testing & Services Testing ... the full story, click here . What is whole genome sequencing? Whole genome sequencing is the mapping out ...

  5. Genomes on ice.

    Science.gov (United States)

    Parkhill, Julian

    2016-03-01

    This month's Genome Watch discusses the analysis of a Helicobacter pylori genome from the preserved Copper-Age mummy known as the Iceman and how ancient genomes shed light on the history of bacterial pathogens. PMID:26853114

  6. Rodent malaria parasites : genome organization & comparative genomics

    NARCIS (Netherlands)

    Kooij, Taco W.A.

    2006-01-01

    The aim of the studies described in this thesis was to investigate the genome organization of rodent malaria parasites (RMPs) and compare the organization and gene content of the genomes of RMPs and the human malaria parasite P. falciparum. The release of the complete genome sequence of P. falciparu

  7. Gene cloning and expression of glycerol dehydratase from Citrobacter freundii in Escherichia coli%弗氏柠檬酸菌甘油脱水酶基因在大肠杆菌中的克隆和表达

    Institute of Scientific and Technical Information of China (English)

    齐向辉; 朱绮霞; 韦宇拓; 黄鲲; 黄日波

    2005-01-01

    以弗氏柠檬酸菌(Citrobacter freundii)基因组DNA为模板,通过PCR得到甘油脱水酶(glycerol dehydratase)基因dhaB、dhaC、dhaE,克隆到表达载体pSE380上,得到重组质粒pSE-dhaBCE.将此重组质粒转化到E.coliJM109中,重组菌株SDS-PAGE结果显示有明显的61kD、22kD、16kD三条特异性蛋白条带出现.重组菌株经诱导表达,酶活力为11.59U/mL.

  8. Purification and properties of Citrobacter freundii phytase%弗氏柠檬酸杆菌植酸酶的分离纯化及其酶学性质研究

    Institute of Scientific and Technical Information of China (English)

    罗会颖; 石鹏君; 李江; 王亚茹; 姚斌; 黄火青; 袁铁铮; 柏映国

    2006-01-01

    从弗氏柠檬酸杆菌(Citrobacter freundii)中分离纯化了一种植酸酶并进行了酶学性质研究,其反应最适pH为4.0~4.5,最适温度为40℃,在37℃下以植酸钠为底物的Km值为0.85nmol/L,Vmax为0.53IU/(mg·min),具有较好的抗胰蛋白酶的能力.酶蛋白的分子量大小约为45kDa,成熟酶蛋白N端序列为QCAPEGYQLQQVLMM.

  9. Isolation and identification of Citrobacter freundii from Cherax quadricarinatus%红螯螯虾弗氏柠檬酸杆菌病病原的分离与鉴定

    Institute of Scientific and Technical Information of China (English)

    沈锦玉; 顾志敏; 潘晓艺; 周保中; 尹文林; 曹铮

    2005-01-01

    从濒死的红螯螯虾(Cherax quadricarinatus)的肝胰脏中分离得到可疑病菌L1和L2,经细菌学鉴定2株细菌均为弗氏柠檬酸杆菌(Citrobacter freundii);经人工感染试验证实L1和L2均导致健康虾发病死亡,其LD50分别为2.2×105CFU/ind、7×105CFU/ind;2株细菌对14种药物的敏感性相似,对9种抗生素敏感,对5种抗生素有抗性.从中筛选出有效药物,应用于生产中取得了较好效果.

  10. Investigation of a foodborne disease outbreak caused by Citrobacter freundii%一起弗氏柠檬酸杆菌所致食源性疾病调查

    Institute of Scientific and Technical Information of China (English)

    闫革彬; 隋吉林; 芦丹; 刘重程; 王涛

    2013-01-01

    本文用描述性流行病学分析方法,对一起集体聚餐所致食源性疾病进行分析,根据流行病学调查资料、病例临床特点和实验室检验结果,证实该起食源性疾病由食用受弗氏柠檬酸杆菌污染的食品所致.%Descriptive epidemiological analysis was conducted on a food borne disease outbreak after a mass dinner, and laboratory detection was performed to understand the etiology of the disease. According to the epidemiological survey and laboratory detection results, the outbreak was identified to be caused by the food contaminated with Citrobacter freundii.

  11. 弗氏柠檬酸杆菌随机扩增多态性DNA法基因分型%Genotyping of Citrobacter freundii by Randomly Amplified Polymorphic DNA Technique

    Institute of Scientific and Technical Information of China (English)

    叶明亮; 黄象艳; 吕波; 侯晓琦; 李银太

    2005-01-01

    目的建立弗氏柠檬酸杆菌(Citrobacter freundii)随机扩增多态性DNA(RAPD)法基因分型图谱. 方法以优化的反应体系及单一随机引物L8,对临床分离的116株C.freundii进行RAPD分析,并按指纹图上DNA条带数及片段大小绘制基因分型图谱. 结果 116株临床分离C.freundii共得78种RAPD型. 结论 RAPD法可将C.freundii分型78种.

  12. Funding Opportunity: Genomic Data Centers

    Science.gov (United States)

    Funding Opportunity CCG, Funding Opportunity Center for Cancer Genomics, CCG, Center for Cancer Genomics, CCG RFA, Center for cancer genomics rfa, genomic data analysis network, genomic data analysis network centers,

  13. Isolation, identification and antibiotics susceptibility test of Citrobacter freundii from Procambarus clarkii%克氏原螯虾弗氏柠檬酸杆菌的分离鉴定与药敏试验

    Institute of Scientific and Technical Information of China (English)

    陈红莲; 宋光同; 何吉祥; 侯冠军; 王永杰

    2014-01-01

    为确定引起养殖克氏原螯虾( Procambarus clarkii)患病的病原种类及耐药情况,从患病克氏原螯虾肝胰腺取样进行常规细菌学检查,对分离株进行回归感染试验、形态观察、生理生化特性检测、16S rRNA和gyrB基因分析及药敏试验。结果显示:从患病克氏原螯虾肝胰腺分离到大量菌落形态和色泽一致的细菌,代表菌株X120523为弗氏柠檬酸杆菌( Citrobacter freundii),具有较强致病性,对20种抗生素中的喹诺酮类和氨基糖苷类抗生素敏感。%This experiment was conducted to clarify species and drug resistance of pathogen from the diseased Procambarus clarkia.Pathogenic bacteria from hepatopancreas of the diseased Procambarus clarkia were examined using conventional methods and isolated.The further tests and analysis of the isolated strain were developed , including the regression experi-ment to Procambarus clarkii, the morphology, physiological and biochemical characteristics , sequence analysis of their 16S rRNA and gyrB genes , and the susceptibility test to antibiotics.Large colonies with similar morphology and color were obtained.Strain X120523 was identified as Citrobacter freundii, proved to have strong pathogenicity , and susceptible to quinolones and aminoglycosides.

  14. Enabling functional genomics with genome engineering.

    Science.gov (United States)

    Hilton, Isaac B; Gersbach, Charles A

    2015-10-01

    Advances in genome engineering technologies have made the precise control over genome sequence and regulation possible across a variety of disciplines. These tools can expand our understanding of fundamental biological processes and create new opportunities for therapeutic designs. The rapid evolution of these methods has also catalyzed a new era of genomics that includes multiple approaches to functionally characterize and manipulate the regulation of genomic information. Here, we review the recent advances of the most widely adopted genome engineering platforms and their application to functional genomics. This includes engineered zinc finger proteins, TALEs/TALENs, and the CRISPR/Cas9 system as nucleases for genome editing, transcription factors for epigenome editing, and other emerging applications. We also present current and potential future applications of these tools, as well as their current limitations and areas for future advances. PMID:26430154

  15. Genome Mapping in Plant Comparative Genomics.

    Science.gov (United States)

    Chaney, Lindsay; Sharp, Aaron R; Evans, Carrie R; Udall, Joshua A

    2016-09-01

    Genome mapping produces fingerprints of DNA sequences to construct a physical map of the whole genome. It provides contiguous, long-range information that complements and, in some cases, replaces sequencing data. Recent advances in genome-mapping technology will better allow researchers to detect large (>1kbp) structural variations between plant genomes. Some molecular and informatics complications need to be overcome for this novel technology to achieve its full utility. This technology will be useful for understanding phenotype responses due to DNA rearrangements and will yield insights into genome evolution, particularly in polyploids. In this review, we outline recent advances in genome-mapping technology, including the processes required for data collection and analysis, and applications in plant comparative genomics.

  16. Exploring Other Genomes: Bacteria.

    Science.gov (United States)

    Flannery, Maura C.

    2001-01-01

    Points out the importance of genomes other than the human genome project and provides information on the identified bacterial genomes Pseudomonas aeuroginosa, Leprosy, Cholera, Meningitis, Tuberculosis, Bubonic Plague, and plant pathogens. Considers the computer's use in genome studies. (Contains 14 references.) (YDS)

  17. GENOMIC MEDICINE

    Directory of Open Access Journals (Sweden)

    Ignacio Briceño Balcázar

    2011-03-01

    Full Text Available Until the twilight of the 20th century, genetics was a branch of medicine applied to diseases of rare occurrence. The advent of the human genome sequence and the possibility of studying it at affordable costs for patients and healthcare institutions, has permitted its application in high-priority diseases like cancer, cardiovascular disease, diabetes, and Alzheimer’s, among others.There is great potential in predictive and preventive medicine, through studying polymorphic genetic variants associated to risks for different diseases. Currently, clinical laboratories offer studies of over 30,000 variants associated with susceptibilities, to which individuals can access without much difficulty because a medical prescription is not required. These exams permit conducting a specific plan of preventive medicine. For example, upon the possibility of finding a deleterious mutation in the BRCA1 and BRCA2 genes, the patient can prevent the breast cancer by mastectomy or chemoprophylaxis and in the presence of polymorphisms associated to cardiovascular risk preventive action may be undertaken through changes in life style (diet, exercise, etc..Legal aspects are also present in this new conception of medicine. For example, currently there is legislation for medications to indicate on their labels the different responses such medication can offer regarding the genetic variants of the patients, given that similar doses may provoke adverse reactions in an individual, while for another such dosage may be insufficient. This scenario would allow verifying the polymorphisms of drug response prior to administering medications like anticoagulants, hyperlipidemia treatments, or chemotherapy, among others.We must specially mention recessive diseases, produced by the presence of two alleles of a mutated gene, which are inherited from the mother, as well as the father. By studying the mutations, we may learn if a couple is at risk of bearing children with the disease

  18. Genomic Medicine

    Directory of Open Access Journals (Sweden)

    Ignacio Briceño Balcázar

    2011-04-01

    Full Text Available Until the twilight of the 20th century, genetics was a branch of medicine applied to diseases of rare occurrence.  The advent of the human genome sequence and the possibility of studying it at affordable costs for patients and healthcare institutions, has permitted its application in high-priority diseases like cancer, cardiovascular disease, diabetes, and Alzheimer’s, among others. There is great potential in predictive and preventive medicine, through studying polymorphic genetic variants associated to risks for different diseases. Currently, clinical laboratories offer studies of over 30,000 variants associated with susceptibilities, to which individuals can access without much difficulty because a medical prescription is not required. These exams permit conducting a specific plan of preventive medicine.  For example, upon the possibility of finding a deleterious mutation in the BRCA1 and BRCA2 genes, the patient can prevent the breast cancer by mastectomy or chemoprophylaxis and in the presence of polymorphisms associated to cardiovascular risk preventive action may be undertaken through changes in life style (diet, exercise, etc.. Legal aspects are also present in this new conception of medicine.  For example, currently there is legislation for medications to indicate on their labels the different responses such medication can offer regarding the genetic variants of the patients, given that similar doses may provoke adverse reactions in an individual, while for another such dosage may be insufficient. This scenario would allow verifying the polymorphisms of drug response prior to administering medications like anticoagulants, hyperlipidemia treatments, or chemotherapy, among others. We must specially mention recessive diseases, produced by the presence of two alleles of a mutated gene, which are inherited from the mother, as well as the father. By studying the mutations, we may learn if a couple is at risk of bearing children with the

  19. Genomes and evolutionary genomics of animals

    Institute of Scientific and Technical Information of China (English)

    Luting SONG; Wen WANG

    2013-01-01

    Alongside recent advances and booming applications of DNA sequencing technologies,a great number of complete genome sequences for animal species are available to researchers.Hundreds of animals have been involved in whole genome sequencing,and at least 87 non-human animal species' complete or draft genome sequences have been published since 1998.Based on these technological advances and the subsequent accumulation of large quantity of genomic data,evolutionary genomics has become one of the most rapidly advancing disciplines in biology.Scientists now can perform a number of comparative and evolutionary genomic studies for animals,to identify conserved genes or other functional elements among species,genomic elements that confer animals their own specific characteristics and new phenotypes for adaptation.This review deals with the current genomic and evolutionary research on non-human animals,and displays a comprehensive landscape of genomes and the evolutionary genomics of non-human animals.It is very helpful to a better understanding of the biology and evolution of the myriad forms within the animal kingdom [Current Zoology 59 (1):87-98,2013].

  20. Genome Maps, a new generation genome browser

    Science.gov (United States)

    Medina, Ignacio; Salavert, Francisco; Sanchez, Rubén; de Maria, Alejandro; Alonso, Roberto; Escobar, Pablo; Bleda, Marta; Dopazo, Joaquín

    2013-01-01

    Genome browsers have gained importance as more genomes and related genomic information become available. However, the increase of information brought about by new generation sequencing technologies is, at the same time, causing a subtle but continuous decrease in the efficiency of conventional genome browsers. Here, we present Genome Maps, a genome browser that implements an innovative model of data transfer and management. The program uses highly efficient technologies from the new HTML5 standard, such as scalable vector graphics, that optimize workloads at both server and client sides and ensure future scalability. Thus, data management and representation are entirely carried out by the browser, without the need of any Java Applet, Flash or other plug-in technology installation. Relevant biological data on genes, transcripts, exons, regulatory features, single-nucleotide polymorphisms, karyotype and so forth, are imported from web services and are available as tracks. In addition, several DAS servers are already included in Genome Maps. As a novelty, this web-based genome browser allows the local upload of huge genomic data files (e.g. VCF or BAM) that can be dynamically visualized in real time at the client side, thus facilitating the management of medical data affected by privacy restrictions. Finally, Genome Maps can easily be integrated in any web application by including only a few lines of code. Genome Maps is an open source collaborative initiative available in the GitHub repository (https://github.com/compbio-bigdata-viz/genome-maps). Genome Maps is available at: http://www.genomemaps.org. PMID:23748955

  1. Genome Maps, a new generation genome browser.

    Science.gov (United States)

    Medina, Ignacio; Salavert, Francisco; Sanchez, Rubén; de Maria, Alejandro; Alonso, Roberto; Escobar, Pablo; Bleda, Marta; Dopazo, Joaquín

    2013-07-01

    Genome browsers have gained importance as more genomes and related genomic information become available. However, the increase of information brought about by new generation sequencing technologies is, at the same time, causing a subtle but continuous decrease in the efficiency of conventional genome browsers. Here, we present Genome Maps, a genome browser that implements an innovative model of data transfer and management. The program uses highly efficient technologies from the new HTML5 standard, such as scalable vector graphics, that optimize workloads at both server and client sides and ensure future scalability. Thus, data management and representation are entirely carried out by the browser, without the need of any Java Applet, Flash or other plug-in technology installation. Relevant biological data on genes, transcripts, exons, regulatory features, single-nucleotide polymorphisms, karyotype and so forth, are imported from web services and are available as tracks. In addition, several DAS servers are already included in Genome Maps. As a novelty, this web-based genome browser allows the local upload of huge genomic data files (e.g. VCF or BAM) that can be dynamically visualized in real time at the client side, thus facilitating the management of medical data affected by privacy restrictions. Finally, Genome Maps can easily be integrated in any web application by including only a few lines of code. Genome Maps is an open source collaborative initiative available in the GitHub repository (https://github.com/compbio-bigdata-viz/genome-maps). Genome Maps is available at: http://www.genomemaps.org. PMID:23748955

  2. Genome Maps, a new generation genome browser.

    Science.gov (United States)

    Medina, Ignacio; Salavert, Francisco; Sanchez, Rubén; de Maria, Alejandro; Alonso, Roberto; Escobar, Pablo; Bleda, Marta; Dopazo, Joaquín

    2013-07-01

    Genome browsers have gained importance as more genomes and related genomic information become available. However, the increase of information brought about by new generation sequencing technologies is, at the same time, causing a subtle but continuous decrease in the efficiency of conventional genome browsers. Here, we present Genome Maps, a genome browser that implements an innovative model of data transfer and management. The program uses highly efficient technologies from the new HTML5 standard, such as scalable vector graphics, that optimize workloads at both server and client sides and ensure future scalability. Thus, data management and representation are entirely carried out by the browser, without the need of any Java Applet, Flash or other plug-in technology installation. Relevant biological data on genes, transcripts, exons, regulatory features, single-nucleotide polymorphisms, karyotype and so forth, are imported from web services and are available as tracks. In addition, several DAS servers are already included in Genome Maps. As a novelty, this web-based genome browser allows the local upload of huge genomic data files (e.g. VCF or BAM) that can be dynamically visualized in real time at the client side, thus facilitating the management of medical data affected by privacy restrictions. Finally, Genome Maps can easily be integrated in any web application by including only a few lines of code. Genome Maps is an open source collaborative initiative available in the GitHub repository (https://github.com/compbio-bigdata-viz/genome-maps). Genome Maps is available at: http://www.genomemaps.org.

  3. Genomic Encyclopedia of Fungi

    Energy Technology Data Exchange (ETDEWEB)

    Grigoriev, Igor

    2012-08-10

    Genomes of fungi relevant to energy and environment are in focus of the Fungal Genomic Program at the US Department of Energy Joint Genome Institute (JGI). Its key project, the Genomics Encyclopedia of Fungi, targets fungi related to plant health (symbionts, pathogens, and biocontrol agents) and biorefinery processes (cellulose degradation, sugar fermentation, industrial hosts), and explores fungal diversity by means of genome sequencing and analysis. Over 150 fungal genomes have been sequenced by JGI to date and released through MycoCosm (www.jgi.doe.gov/fungi), a fungal web-portal, which integrates sequence and functional data with genome analysis tools for user community. Sequence analysis supported by functional genomics leads to developing parts list for complex systems ranging from ecosystems of biofuel crops to biorefineries. Recent examples of such parts suggested by comparative genomics and functional analysis in these areas are presented here.

  4. JGI Fungal Genomics Program

    Energy Technology Data Exchange (ETDEWEB)

    Grigoriev, Igor V.

    2011-03-14

    Genomes of energy and environment fungi are in focus of the Fungal Genomic Program at the US Department of Energy Joint Genome Institute (JGI). Its key project, the Genomics Encyclopedia of Fungi, targets fungi related to plant health (symbionts, pathogens, and biocontrol agents) and biorefinery processes (cellulose degradation, sugar fermentation, industrial hosts), and explores fungal diversity by means of genome sequencing and analysis. Over 50 fungal genomes have been sequenced by JGI to date and released through MycoCosm (www.jgi.doe.gov/fungi), a fungal web-portal, which integrates sequence and functional data with genome analysis tools for user community. Sequence analysis supported by functional genomics leads to developing parts list for complex systems ranging from ecosystems of biofuel crops to biorefineries. Recent examples of such 'parts' suggested by comparative genomics and functional analysis in these areas are presented here

  5. Genomic Data Commons | Office of Cancer Genomics

    Science.gov (United States)

    The NCI’s Center for Cancer Genomics launches the Genomic Data Commons (GDC), a unified data sharing platform for the cancer research community. The mission of the GDC is to enable data sharing across the entire cancer research community, to ultimately support precision medicine in oncology.

  6. Phytophthora genomics: the plant destroyers' genome decoded

    NARCIS (Netherlands)

    Govers, F.; Gijzen, M.

    2006-01-01

    The year 2004 was an exciting one for the Phytophthora research community. The United States Department of Energy Joint Genome Institute (JGI) completed the draft genome sequence of two Phytophthora species, Phytophthora sojae and Phytophthora ramorum. In August of that year over 50 people gathered

  7. Comparative Genome Analysis and Genome Evolution

    NARCIS (Netherlands)

    Snel, Berend

    2003-01-01

    This thesis described a collection of bioinformatic analyses on complete genome sequence data. We have studied the evolution of gene content and find that vertical inheritance dominates over horizontal gene trasnfer, even to the extent that we can use the gene content to make genome phylogenies. Usi

  8. CD4+ lymphoid tissue inducer cells promote innate immunity in the gut

    OpenAIRE

    Sonnenberg, Gregory F.; Monticelli, Laurel A.; Elloso, M. Merle; Fouser, Lynette A.; Artis, David

    2010-01-01

    Fetal CD4+ lymphoid tissue inducer (LTi) cells play a critical role in the development of lymphoid-tissues. Recent studies identified that LTi cells persist in adults and are related to a heterogeneous population of innate lymphoid cells that have been implicated in inflammatory responses. However, whether LTi cells contribute to protective immunity remains poorly defined. We demonstrate that following infection with Citrobacter rodentium, CD4+ LTi cells were a dominant source of interleukin-...

  9. Genomic Data Commons launches

    Science.gov (United States)

    The Genomic Data Commons (GDC), a unified data system that promotes sharing of genomic and clinical data between researchers, launched today with a visit from Vice President Joe Biden to the operations center at the University of Chicago.

  10. Rat Genome Database (RGD)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Rat Genome Database (RGD) is a collaborative effort between leading research institutions involved in rat genetic and genomic research to collect, consolidate,...

  11. Genomics of Sorghum

    OpenAIRE

    Paterson, Andrew H.

    2008-01-01

    Sorghum (Sorghum bicolor (L.) Moench) is a subject of plant genomics research based on its importance as one of the world's leading cereal crops, a biofuels crop of high and growing importance, a progenitor of one of the world's most noxious weeds, and a botanical model for many tropical grasses with complex genomes. A rich history of genome analysis, culminating in the recent complete sequencing of the genome of a leading inbred, provides a foundation for invigorating progress toward relatin...

  12. Exploiting the genome

    Energy Technology Data Exchange (ETDEWEB)

    Block, S. [The MITRE Corporation, McLean, VA (US). JASON Program Office; Cornwall, J. [The MITRE Corporation, McLean, VA (US). JASON Program Office; Dyson, F. [The MITRE Corporation, McLean, VA (US). JASON Program Office; Koonin, S. [The MITRE Corporation, McLean, VA (US). JASON Program Office; Lewis, N. [The MITRE Corporation, McLean, VA (US). JASON Program Office; Schwitters, R. [The MITRE Corporation, McLean, VA (US). JASON Program Office

    1998-09-11

    In 1997, JASON conducted a DOE-sponsored study of the human genome project with special emphasis on the areas of technology, quality assurance and quality control, and informatics. The present study has two aims: first, to update the 1997 Report in light of recent developments in genome sequencing technology, and second, to consider possible roles for the DOE in the ''post-genomic" era, following acquisition of the complete human genome sequence.

  13. 产CMY型AmpC酶费劳地枸橼酸杆菌的分子学特性研究%Study on molecule characteristics of a novel CMY-type AmpC β-Lactamase from Citrobacter freundii

    Institute of Scientific and Technical Information of China (English)

    张晓坤; 徐韫健; 廖伟娇; 张东梅; 张丽梅

    2011-01-01

    目的 对产CMY型AmpC酶费劳地枸橼酸杆菌进行耐药表型及分子学特性进行研究,探讨研制新的酶抑制剂.方法 对临床分离的两株费劳地枸橼酸杆菌所产CMY型AmpC酶用纸片扩散法、三相水解试验进行耐药表型检测,以该菌总基因组DNA和质粒DNA为模板进行PCR扩增、序列分析、质粒接合试验、构建重组表达载体及AmpC酶检测.结果 两株菌株对青霉素类、头孢菌素类、喹诺酮类、氨基糖苷类抗生素均表现为耐药,对呋喃类和碳青霉烯类表现为敏感;三相水解试验结果显示该菌能水解头孢西丁;PCR扩增出大小为1 146 bp的基因片段,与GenBank上多种CMY亚型的基因序列同源性为97%;质粒接合试验证实质粒上含CMY基因,为可转移质粒.结论 两株菌株所产CMY型AmpC酶为新的CMY型头孢菌素酶,它介导了该菌对青霉素类、头孢菌素类、喹诺酮类等抗生素耐药,其耐药性能水平传播.%Objective To investigate the antibiotic phenotype and moleculelogy characteristics of novel CMY-type AmpC β-Lactamase from Citrobacter freundii,in order to triturate homologue enzyme inhibitors. Methods Slip diffusion method and three-phase hydrolyses test were used to analyze antibiotic phenotype of novel CMY-type AmpC β-Lactamase from Citrobacter freundii that was detached from clinic.The DNA and plasmid of CMY-type AmpCβ-Lactamase from Citrobacter freundii Strain was amplified by PCR、sequence analysis.Plasmid Conjugation tests、construction recombinant expression vector and AmpC induce tests. Results Two strains were resistant to penicillins , cephalosporin, quinolone, aminoglycoside , and susceptible to nitrofuran , carbapenem , The results of three-dimension test showed, AmpCβ-Lactamase from DNA Strain and recombinant strain could hydrolyz cefoxitin,The 1 l46bp DNA fragment of CMY-type AmpC β-Lactamase encoding gene sequence shared 97% amino acid identity with CMY-type AmpC β-Lactamase that

  14. Whole Genome Selection

    Science.gov (United States)

    Whole genome selection (WGS) is an approach to using DNA markers that are distributed throughout the entire genome. Genes affecting most economically-important traits are distributed throughout the genome and there are relatively few that have large effects with many more genes with progressively sm...

  15. Chicken's Genome Decoded

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ After completing the work on mapping chicken genome sequence and chicken genome variation in early March, 2004, two international research consortiums have made significant progress in reading the maps, shedding new light on the studies into the first bird as well as the first agricultural animal that has its genome sequenced and analyzed in the world.

  16. Public Health Genomics

    OpenAIRE

    Lavinha, João

    2012-01-01

    Professional genomic and molecular medicine and consumer genetics. The health field concept and the public health wheel. The enterprise of Public Health Genomics (PHGEN). Genetic exceptionalism. Ethical benchmarks. Introduction and use of genome-based knowledge in the health services. Stakeholder involvement.

  17. Ebolavirus comparative genomics

    DEFF Research Database (Denmark)

    Jun, Se-Ran; Leuze, Michael R.; Nookaew, Intawat;

    2015-01-01

    The 2014 Ebola outbreak in West Africa is the largest documented for this virus. To examine the dynamics of this genome, we compare more than 100 currently available ebolavirus genomes to each other and to other viral genomes. Based on oligomer frequency analysis, the family Filoviridae forms...

  18. Isolation and identification of multidrug resistant Citrobacter freundii from diseased soft -shelled turtle, Pelodiscus sinensis%一株多重耐药中华鳖源弗氏柠檬酸杆菌的分离鉴定

    Institute of Scientific and Technical Information of China (English)

    毛烁君; 斯广杰; 任晓金; 石婷婷; 章烨; 王卓瑞; 章晓栋

    2015-01-01

    从患典型鳃腺炎病中华鳖(Pelodiscus sinensis)肝脏和腹水处进行细菌接种,分离获得一株细菌。综合菌落形态,16 S rRNA 序列进化分析和 API 细菌生化鉴定系统判定,所得菌株为弗氏柠檬酸杆菌(Citrobacter freundii)(SX43)。动物回归实验显示,分离株对小鼠的半数致死量(LD50)为106.5 CFU,显示该菌株具有较强的致病性,可从实验幼鳖体内再次分离到相同的病原菌。常用药物的抗菌敏感性测定显示,菌株 SX43对头孢哌酮、头孢曲松、头孢呋辛、复方新诺明、氯霉素高度敏感。%One bacteria was isolated from liver and ascites of diseased soft- shelled turtles( Pelodiscus sinensis) suffered with parotitis, on the colony morphology, Gram’s staining, API ID32E bacterial biochemical identification system and se-quence analysis of 16S rRNA gene, the isolate bacteria was identified as Citrobacter freundii, named SX43.Healthy soft -shelled turtles (Pelodiscus sinensis) were used for experimental infection with bacterial suspension, the same bacterium could be recovered.Isolate SX43 was demonstrated virulence potential in mouse models, with the median lethal dose (LD50 ) in mice at 10 6.5 CFU.The susceptibility test to antibiotics demonstrated that the bacterial strain SX43 was suscepti-ble to cefoperazone, rocephin, cefuroxim, co -trimoxazole, chloramphenicol.

  19. Isolation and identification of Citrobacter sedlakii from Palea steindachneri and its antibiotic sensitivity%山瑞鳖塞氏柠檬酸杆菌的分离鉴定及药物敏感性研究

    Institute of Scientific and Technical Information of China (English)

    韦信贤; 童桂香; 黎小正; 吴祥庆; 庞燕飞

    2010-01-01

    从患致死性传染病的山瑞鳖(Palea steindachneri)组织中分离到一株细菌(YL090422),对该菌形态、生理生化特征及致病性进行分析,并用BIOLOG自动微生物鉴定系统及16S rDNA序列分析对其进行了鉴定.结果显示:该菌具有较强的致病性,且为发酵型革兰氏阴性短杆菌,无芽胞及荚膜;具有对葡萄糖、精氨酸双水解酶、鸟氨酸脱羧酶、脲酶、西蒙氏柠檬酸盐、丙二酸盐、卫茅醇、吲哚、动力等反应呈阳性,对氧化酶、赖氨酸脱羧酶、苯丙氨酸脱氨酶、V-P反应等呈阴性的特点.BIOLOG自动微生物鉴定系统显示该菌为塞氏柠檬酸杆菌(Citrobacter sedlakii).16S rDNA序列分析得到1条长度为1464bp的核苷酸序列(GenBank登录号为GU726186),并显示该分离株与塞氏柠檬酸杆菌(C.sedlakii)的同源性达99.9%,且在系统发育树上与C.sedlakii聚为一支.鉴定结果确认菌株YL090422为塞氏柠檬酸杆菌(Citrobacter sedlakii).药敏试验结果显示:该菌对供试16种抗菌药物中的阿米卡星等3种药物敏感,对头孢哌酮等3种药物中度敏感,对氨苄青霉素等10种抗生素均存在不同程度的耐药.

  20. Isolation and Identification of Citrobacter freundii and Its PCR-SSCP Analysis%弗氏柠檬酸杆菌的分离鉴定与PCR-SSCP分析

    Institute of Scientific and Technical Information of China (English)

    胡秀彩; 王艺; 吕爱军

    2011-01-01

    摘要利用营养琼脂、MaC培养基从草鱼肠道中分离到3株细菌,暂时编号为TC-1、TC-2和TC-3,通过形态学观察、生理生化特征、药敏试验、动物试验、构建系统发育进化树及PCR-SSCP分析等系统鉴定,结果表明3株菌株均为弗氏柠檬酸杆菌(Citrobacter freundii),其中TC-2菌株对小鼠、斑马鱼有致病性;3株菌均对头孢噻肟、头孢曲松、洛美沙星、诺氟沙星等多种药物敏感;系统发育分析表明,3株弗氏柠檬酸杆菌16S rDNA序列与DSM 30039模式株同源性分别为99.59%、99.47%和99.53%,且位于系统发育树的同一分支;进一步采用V3区PCR-SSCP分析结果显示弗氏柠檬酸杆菌SSCP图谱中菌株间带型存在差异.%The bacteria were isolated from intestine in grass carp ( Ctenopharyngodon idellus ) using nutrient agar and MaC medium, designated temporarily as TC-1, TC-2 and TC-3, and identified with morphological observation, physiological and biochemical characteristics, drug sensitive test, animal test, established phylogcnctic tree, as well as PCR-SSCP analysis. The results showed that all 3 strains were Citrobacter freundii (Cf). Animal tests showed that TC-2 strain was lethal to mice and zebrafish, respectively. Drug sensitivity test analysis revealed that 3 strains were sensitivity to cefotaxime, ceftriaxone, lomefloxacin, norfloxacin, and many others. The phylogenetic analysis showed that 16S rDNA sequence of the 3 strains had homoiogy to the typical strain DSM 30039 at 99. 59% , 99. 47% and 99.53% respectively, and they located on the same branch of the phylogenelic tree. Further analysis results adopting V3 region of PCR-SSCP showed there were differences among SSCP atlases of Cf strains.

  1. The Genomic Medicine Game.

    Science.gov (United States)

    Tran, Elvis; de Andrés-Galiana, Enrique J; Benitez, Sonia; Martin-Sanchez, Fernando; Lopez-Campos, Guillermo H

    2016-01-01

    With advancements in genomics technology, health care has been improving and new paradigms of medicine such as genomic medicine have evolved. The education of clinicians, researchers and students to face the challenges posed by these new approaches, however, has been often lagging behind. From this the Genomic Medicine Game, an educational tool, was created for the purpose of conceptualizing the key components of Genomic Medicine. A number of phenotype-genotype associations were found through a literature review, which was used to be a base for the concepts the Genomic Medicine Game would focus on. Built in Java, the game was successfully tested with promising results. PMID:27577486

  2. A genome blogger manifesto

    Directory of Open Access Journals (Sweden)

    Corpas Manuel

    2012-10-01

    Full Text Available Abstract Cheap prices for genomic testing have revolutionized consumers’ access to personal genomics. Exploration of personal genomes poses significant challenges for customers wishing to learn beyond provider customer reports. A vibrant community has spontaneously appeared blogging experiences and data as a way to learn about their personal genomes. No set of values has publicly been described to date encapsulating ideals and code of conduct for this community. Here I present a first attempt to address this vacuum based on my own personal experiences as genome blogger.

  3. Statistics of genome architecture

    International Nuclear Information System (INIS)

    The main statistical distributions applicable to the analysis of genome architecture and genome tracks are briefly discussed and critically assessed. Although the observed features in distributions of element lengths can be equally well fitted by the different statistical approximations, the interpretation of observed regularities may strongly depend on the chosen scheme. We discuss the possible evolution scenarios and describe the main characteristics obtained with different distributions. The expression for the assessment of levels in hierarchical chromatin folding is derived and the quantitative measure of genome architecture inhomogeneity is suggested. This theory provides the ground for the regular statistical study of genome architecture and genome tracks.

  4. Activation of intestinal epithelial Stat3 orchestrates tissue defense during gastrointestinal infection.

    Directory of Open Access Journals (Sweden)

    Nadine Wittkopf

    Full Text Available Gastrointestinal infections with EHEC and EPEC are responsible for outbreaks of diarrheal diseases and represent a global health problem. Innate first-line-defense mechanisms such as production of mucus and antimicrobial peptides by intestinal epithelial cells are of utmost importance for host control of gastrointestinal infections. For the first time, we directly demonstrate a critical role for Stat3 activation in intestinal epithelial cells upon infection of mice with Citrobacter rodentium - a murine pathogen that mimics human infections with attaching and effacing Escherichia coli. C. rodentium induced transcription of IL-6 and IL-22 in gut samples of mice and was associated with activation of the transcription factor Stat3 in intestinal epithelial cells. C. rodentium infection induced expression of several antimicrobial peptides such as RegIIIγ and Pla2g2a in the intestine which was critically dependent on Stat3 activation. Consequently, mice with specific deletion of Stat3 in intestinal epithelial cells showed increased susceptibility to C. rodentium infection as indicated by high bacterial load, severe gut inflammation, pronounced intestinal epithelial cell death and dissemination of bacteria to distant organs. Together, our data implicate an essential role for Stat3 activation in intestinal epithelial cells during C. rodentium infection. Stat3 concerts the host response to bacterial infection by controlling bacterial growth and suppression of apoptosis to maintain intestinal epithelial barrier function.

  5. Causes of genome instability

    DEFF Research Database (Denmark)

    Langie, Sabine A S; Koppen, Gudrun; Desaulniers, Daniel;

    2015-01-01

    Genome instability is a prerequisite for the development of cancer. It occurs when genome maintenance systems fail to safeguard the genome's integrity, whether as a consequence of inherited defects or induced via exposure to environmental agents (chemicals, biological agents and radiation). Thus......, genome instability can be defined as an enhanced tendency for the genome to acquire mutations; ranging from changes to the nucleotide sequence to chromosomal gain, rearrangements or loss. This review raises the hypothesis that in addition to known human carcinogens, exposure to low dose of other...... chemicals present in our modern society could contribute to carcinogenesis by indirectly affecting genome stability. The selected chemicals with their mechanisms of action proposed to indirectly contribute to genome instability are: heavy metals (DNA repair, epigenetic modification, DNA damage signaling...

  6. Bacterial Adrenergic Sensors Regulate Virulence of Enteric Pathogens in the Gut

    Directory of Open Access Journals (Sweden)

    Cristiano G. Moreira

    2016-06-01

    Full Text Available Enteric pathogens such as enterohemorrhagic Escherichia coli (EHEC and Citrobacter rodentium, which is largely used as a surrogate EHEC model for murine infections, are exposed to several host neurotransmitters in the gut. An important chemical exchange within the gut involves the neurotransmitters epinephrine and/or norepinephrine, extensively reported to increase virulence gene expression in EHEC, acting through two bacterial adrenergic sensors: QseC and QseE. However, EHEC is unable to establish itself and cause its hallmark lesions, attaching and effacing (AE lesions, on murine enterocytes. To address the role of these neurotransmitters during enteric infection, we employed C. rodentium. Both EHEC and C. rodentium harbor the locus of enterocyte effacement (LEE that is necessary for AE lesion formation. Here we show that expression of the LEE, as well as that of other virulence genes in C. rodentium, is also activated by epinephrine and/or norepinephrine. Both QseC and QseE are required for LEE gene activation in C. rodentium, and the qseC and qseE mutants are attenuated for murine infection. C. rodentium has a decreased ability to colonize dopamine β-hydroxylase knockout (Dbh−/− mice, which do not produce epinephrine and norepinephrine. Both adrenergic sensors are required for C. rodentium to sense these neurotransmitters and activate the LEE genes during infection. These data indicate that epinephrine and norepinephrine are sensed by bacterial adrenergic receptors during enteric infection to promote activation of their virulence repertoire. This is the first report of the role of these neurotransmitters during mammalian gastrointestinal (GI infection by a noninvasive pathogen.

  7. Development in Rice Genome Research Based on Accurate Genome Sequence

    OpenAIRE

    2008-01-01

    Rice is one of the most important crops in the world. Although genetic improvement is a key technology for the acceleration of rice breeding, a lack of genome information had restricted efforts in molecular-based breeding until the completion of the high-quality rice genome sequence, which opened new opportunities for research in various areas of genomics. The syntenic relationship of the rice genome to other cereal genomes makes the rice genome invaluable for understanding how cereal genomes...

  8. Whole-exome/genome sequencing and genomics.

    Science.gov (United States)

    Grody, Wayne W; Thompson, Barry H; Hudgins, Louanne

    2013-12-01

    As medical genetics has progressed from a descriptive entity to one focused on the functional relationship between genes and clinical disorders, emphasis has been placed on genomics. Genomics, a subelement of genetics, is the study of the genome, the sum total of all the genes of an organism. The human genome, which is contained in the 23 pairs of nuclear chromosomes and in the mitochondrial DNA of each cell, comprises >6 billion nucleotides of genetic code. There are some 23,000 protein-coding genes, a surprisingly small fraction of the total genetic material, with the remainder composed of noncoding DNA, regulatory sequences, and introns. The Human Genome Project, launched in 1990, produced a draft of the genome in 2001 and then a finished sequence in 2003, on the 50th anniversary of the initial publication of Watson and Crick's paper on the double-helical structure of DNA. Since then, this mass of genetic information has been translated at an ever-increasing pace into useable knowledge applicable to clinical medicine. The recent advent of massively parallel DNA sequencing (also known as shotgun, high-throughput, and next-generation sequencing) has brought whole-genome analysis into the clinic for the first time, and most of the current applications are directed at children with congenital conditions that are undiagnosable by using standard genetic tests for single-gene disorders. Thus, pediatricians must become familiar with this technology, what it can and cannot offer, and its technical and ethical challenges. Here, we address the concepts of human genomic analysis and its clinical applicability for primary care providers.

  9. 乌翅真鲨弗氏柠檬酸杆菌的分离与鉴定%Isolation and Identification of Pathogenic Bacterium Citrobacter Freundii from Blacktip Reef Shark Carcharhinus melanopterus

    Institute of Scientific and Technical Information of China (English)

    卢君辉; 孙佳佳; 董世龙; 任硕

    2015-01-01

    为确定引起乌翅真鲨(Carcharhinus melanopterus)患病的病原种类及耐药情况,用常规方法从患病乌翅真鲨内脏取样分离得到的1株优势菌,通过回归感染试验确定该菌株的致病性,通过经典生理生化分析、API 20E细菌快速鉴定系统、16S rDNA序列分析对其进行鉴定,确定该株致病菌为弗氏柠檬酸杆菌(Citrobacter freundii).药敏试验结果表明:该菌株对左氧氟沙星、头孢曲松钠、四环素、链霉素和庆大霉素等敏感.

  10. Mechanism of resistance to β-lactam antibiotics in Citrobacter%枸橼酸杆菌对β-内酰胺类抗生素的耐药机制

    Institute of Scientific and Technical Information of China (English)

    余燕; 徐建国; 熊衍文; 叶长芸

    2008-01-01

    枸橼酸杆菌(Citrobacter)是一种条件致病菌,近年来在临床上造成的感染越来越多,随之而来的是枸橼酸杆菌对常用抗生素(如β-内酰胺类、氨基糖甙类和喹诺酮类等药物)的耐药性日益突出.枸橼酸杆菌对β-内酰胺类抗生素的耐药机制主要是产生特异性的β-内酰胺酶,而且不同种枸橼酸杆菌对抗生素的敏感性不同.因此,了解枸橼酸杆菌的耐药机制及进展,对预防和治疗由该属细菌引起的感染以及控制耐药性的蔓延有重要意义.

  11. 枸橼酸杆菌中质粒介导喹诺酮耐药基因的检测%Study of plasmid-mediated quinolone resistance determinants in Citrobacter freundii

    Institute of Scientific and Technical Information of China (English)

    邵宜波; 李旭; 胡立芬; 谢琴秀

    2013-01-01

    目的 了解枸橼酸杆菌中质粒介导喹诺酮耐药(PMQR)基因的分布,以期发现新型PMQR基因.测定临床分离的PMQR基因阳性枸橼酸杆菌对临床常用抗菌药物的敏感性.方法 收集安徽医科大学第一附属医院检验科2009年临床分离的枸橼酸杆菌,PCR扩增qnr、aac(6′)-Ib-cr和qepA基因,产物纯化测序,测序结果在GenBank上比对并行转移接合实验.对收集的PMQR基因阳性枸橼酸杆菌及其接合子,采用琼脂对倍稀释法进行临床常用抗菌药物的药物敏感试验.结果 收集的枸橼酸杆菌共31株,8株菌株扩增出qnr,qnr基因阳性率为25.8%;其中6株扩增出qnrB.4株qnr阳性菌株的qnr基因转移接合成功.在qnr阳性的枸橼酸杆菌中,测序发现1种PMQR基因新亚型,命名为qnrB24.所有qnr阳性临床菌株对喹诺酮类药物的耐药率为87.5%,对头孢噻肟、阿米卡星、头孢他啶、头孢吡肟和庆大霉素的耐药率分别为75.0%、7.5%、62.5%、37.5%和87.5%,所有qnr阳性菌株对亚胺培南耐药表型为敏感.喹诺酮类药物对qnr阳性的接合子最低抑菌浓度升高10~23倍,敏感性下降.结论 安徽地区枸橼酸杆菌中qnr基因型的检出率较高,以qnrB基因型为主,qnr阳性枸橼酸杆菌对常用抗菌药物耐药性较高.%Objectives This study was conducted to detect and analyze the presence of plasmidmediated quinolone resistance (PMQR) determinants [qnr,aac-(6′)-Ib-cr and qepA] among clinical isolates of Citrobacter freundii strains isolated from patients in Anhui,China,and to understand the susceptibility of PMQR positive strains to commonly used antimicrobial agents.Methods During the year 2009,31 Citrobacter strains were collected from the First Affiliated Hospital of Anhui Medical University.Polymerase chain reaction (PCR) was used to detect PMQR genes.Amplicons were purified,sequenced and compared with data from the GenBank.Conjugation experiments were conducted to

  12. Isolation and algicidal characteristics of Citrobacter sp.strain N10%柠檬酸杆菌 N10的分离及其溶藻特性

    Institute of Scientific and Technical Information of China (English)

    孙朋飞; 卢丽玲; 王冠; 赵宇华

    2013-01-01

    Summary In recent decades,harmful algal blooms(HABs),which are natural phenomena that occur across all the world, have posed threats to decrease dissolved oxygen and have had a negative effect on fisheries, aquaculture,drinking water,tourism and human health.It is increasingly urgent to develop useful strategies for predicting and reducing the negative impacts of HABs.Actually,many methods have been devoted to controlling HABs,including copper sulfate,hydrogen peroxide,ozonization,ultrasonication,collection of algae from water surface using nets,iron powder and magnets,centrifugal separation,or ultraviolet radiation.As an effective and environment friendly strategy to control harmful algal bloom outbreaks,biologic control methods such as using algicidal bacteria against M.aeruginosa have been more and more attractive.It has been demonstrated that algicidal bacteria could serve as potential ways in reducing the impacts of HABs. In this study,a Citrobacter sp.N10 with algicidal activity against the toxic algae M.aeruginosa was isolated and identified from a lake of Zhejiang University using liquid infection technology and 1 6S rDNA sequence analysis.The growth and algicidal characters of Citrobacter sp.N10 were then studied in order to offer some useful information for HABs controlling. The results showed that the bacterium was gram-negative and its colonies were smooth, convex, low moisture,translucent or opaque and gray,and its colony surfaces were glossy.Sequence analysis of 1 6S rDNA demonstrated that strain N10 belonged to Citrobacter sp.When inoculation time was 2 to 12 h,N10 grew in logarithmic-growth period,and when inoculation time was beyond 12 h,N10 was in stationary phase.Strain N10 showed a high lysis of M.aeruginosa with an algicidal rate of 86.55% within 24 h.The algicidal rate of N10 increased with increasing incubation time and reached 97.08% within 72 h.pH value had the most significant effect on the growth of strain N10,followed by Na

  13. Bioinformatics decoding the genome

    CERN Document Server

    CERN. Geneva; Deutsch, Sam; Michielin, Olivier; Thomas, Arthur; Descombes, Patrick

    2006-01-01

    Extracting the fundamental genomic sequence from the DNA From Genome to Sequence : Biology in the early 21st century has been radically transformed by the availability of the full genome sequences of an ever increasing number of life forms, from bacteria to major crop plants and to humans. The lecture will concentrate on the computational challenges associated with the production, storage and analysis of genome sequence data, with an emphasis on mammalian genomes. The quality and usability of genome sequences is increasingly conditioned by the careful integration of strategies for data collection and computational analysis, from the construction of maps and libraries to the assembly of raw data into sequence contigs and chromosome-sized scaffolds. Once the sequence is assembled, a major challenge is the mapping of biologically relevant information onto this sequence: promoters, introns and exons of protein-encoding genes, regulatory elements, functional RNAs, pseudogenes, transposons, etc. The methodological ...

  14. State of cat genomics.

    Science.gov (United States)

    O'Brien, Stephen J; Johnson, Warren; Driscoll, Carlos; Pontius, Joan; Pecon-Slattery, Jill; Menotti-Raymond, Marilyn

    2008-06-01

    Our knowledge of cat family biology was recently expanded to include a genomics perspective with the completion of a draft whole genome sequence of an Abyssinian cat. The utility of the new genome information has been demonstrated by applications ranging from disease gene discovery and comparative genomics to species conservation. Patterns of genomic organization among cats and inbred domestic cat breeds have illuminated our view of domestication, revealing linkage disequilibrium tracks consequent of breed formation, defining chromosome exchanges that punctuated major lineages of mammals and suggesting ancestral continental migration events that led to 37 modern species of Felidae. We review these recent advances here. As the genome resources develop, the cat is poised to make a major contribution to many areas in genetics and biology.

  15. Physician Assistant Genomic Competencies.

    Science.gov (United States)

    Goldgar, Constance; Michaud, Ed; Park, Nguyen; Jenkins, Jean

    2016-09-01

    Genomic discoveries are increasingly being applied to the clinical care of patients. All physician assistants (PAs) need to acquire competency in genomics to provide the best possible care for patients within the scope of their practice. In this article, we present an updated version of PA genomic competencies and learning outcomes in a framework that is consistent with the current medical education guidelines and the collaborative nature of PAs in interprofessional health care teams. PMID:27490287

  16. Genome packaging in viruses

    OpenAIRE

    Sun, Siyang; Rao, Venigalla B.; Rossmann, Michael G.

    2010-01-01

    Genome packaging is a fundamental process in a viral life cycle. Many viruses assemble preformed capsids into which the genomic material is subsequently packaged. These viruses use a packaging motor protein that is driven by the hydrolysis of ATP to condense the nucleic acids into a confined space. How these motor proteins package viral genomes had been poorly understood until recently, when a few X-ray crystal structures and cryo-electron microscopy structures became available. Here we discu...

  17. Querying genomic databases

    Energy Technology Data Exchange (ETDEWEB)

    Baehr, A.; Hagstrom, R.; Joerg, D.; Overbeek, R.

    1991-09-01

    A natural-language interface has been developed that retrieves genomic information by using a simple subset of English. The interface spares the biologist from the task of learning database-specific query languages and computer programming. Currently, the interface deals with the E. coli genome. It can, however, be readily extended and shows promise as a means of easy access to other sequenced genomic databases as well.

  18. Chromium and Genomic Stability

    OpenAIRE

    Wise, Sandra S.; Wise, John Pierce

    2011-01-01

    Many metals serve as micronutrients which protect against genomic instability. Chromium is most abundant in its trivalent and hexavalent forms. Trivalent chromium has historically been considered an essential element, though recent data indicate that while it can have pharmacological effects and value, it is not essential. There are no data indicating that trivalent chromium promotes genomic stability and, instead may promote genomic instability. Hexavalent chromium is widely accepted as high...

  19. The Genome Atlas Resource

    OpenAIRE

    Azam Qureshi, Matloob; Rotenberg, Eva; Stærfeldt, Hans Henrik; Hansson, Lena; Ussery, David

    2010-01-01

    Abstract. The Genome Atlas is a resource for addressing the challenges of synchronising prokaryotic genomic sequence data from multiple public repositories. This resource can integrate bioinformatic analyses in various data format and quality. Existing open source tools have been used together with scripts and algorithms developed in a variety of programming languages at the Centre for Biological Sequence Analysis in order to create a three-tier software application for genome analysis. The r...

  20. Between two fern genomes.

    Science.gov (United States)

    Sessa, Emily B; Banks, Jo Ann; Barker, Michael S; Der, Joshua P; Duffy, Aaron M; Graham, Sean W; Hasebe, Mitsuyasu; Langdale, Jane; Li, Fay-Wei; Marchant, D Blaine; Pryer, Kathleen M; Rothfels, Carl J; Roux, Stanley J; Salmi, Mari L; Sigel, Erin M; Soltis, Douglas E; Soltis, Pamela S; Stevenson, Dennis W; Wolf, Paul G

    2014-01-01

    Ferns are the only major lineage of vascular plants not represented by a sequenced nuclear genome. This lack of genome sequence information significantly impedes our ability to understand and reconstruct genome evolution not only in ferns, but across all land plants. Azolla and Ceratopteris are ideal and complementary candidates to be the first ferns to have their nuclear genomes sequenced. They differ dramatically in genome size, life history, and habit, and thus represent the immense diversity of extant ferns. Together, this pair of genomes will facilitate myriad large-scale comparative analyses across ferns and all land plants. Here we review the unique biological characteristics of ferns and describe a number of outstanding questions in plant biology that will benefit from the addition of ferns to the set of taxa with sequenced nuclear genomes. We explain why the fern clade is pivotal for understanding genome evolution across land plants, and we provide a rationale for how knowledge of fern genomes will enable progress in research beyond the ferns themselves. PMID:25324969

  1. Fungal Genomics Program

    Energy Technology Data Exchange (ETDEWEB)

    Grigoriev, Igor

    2012-03-12

    The JGI Fungal Genomics Program aims to scale up sequencing and analysis of fungal genomes to explore the diversity of fungi important for energy and the environment, and to promote functional studies on a system level. Combining new sequencing technologies and comparative genomics tools, JGI is now leading the world in fungal genome sequencing and analysis. Over 120 sequenced fungal genomes with analytical tools are available via MycoCosm (www.jgi.doe.gov/fungi), a web-portal for fungal biologists. Our model of interacting with user communities, unique among other sequencing centers, helps organize these communities, improves genome annotation and analysis work, and facilitates new larger-scale genomic projects. This resulted in 20 high-profile papers published in 2011 alone and contributing to the Genomics Encyclopedia of Fungi, which targets fungi related to plant health (symbionts, pathogens, and biocontrol agents) and biorefinery processes (cellulose degradation, sugar fermentation, industrial hosts). Our next grand challenges include larger scale exploration of fungal diversity (1000 fungal genomes), developing molecular tools for DOE-relevant model organisms, and analysis of complex systems and metagenomes.

  2. Genome position specific priors for genomic prediction

    DEFF Research Database (Denmark)

    Brøndum, Rasmus Froberg; Su, Guosheng; Lund, Mogens Sandø;

    2012-01-01

    Background The accuracy of genomic prediction is highly dependent on the size of the reference population. For small populations, including information from other populations could improve this accuracy. The usual strategy is to pool data from different populations; however, this has not proven...... as successful as hoped for with distantly related breeds. BayesRS is a novel approach to share information across populations for genomic predictions. The approach allows information to be captured even where the phase of SNP alleles and casual mutation alleles are reversed across populations, or the actual...... casual mutation is different between the populations but affects the same gene. Proportions of a four-distribution mixture for SNP effects in segments of fixed size along the genome are derived from one population and set as location specific prior proportions of distributions of SNP effects...

  3. Genome-Scale Models

    DEFF Research Database (Denmark)

    Bergdahl, Basti; Sonnenschein, Nikolaus; Machado, Daniel;

    2016-01-01

    An introduction to genome-scale models, how to build and use them, will be given in this chapter. Genome-scale models have become an important part of systems biology and metabolic engineering, and are increasingly used in research, both in academica and in industry, both for modeling chemical...

  4. Estimation of genome length

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The genome length is a fundamental feature of a species. This note outlined the general concept and estimation method of the physical and genetic length. Some formulae for estimating the genetic length were derived in detail. As examples, the genome genetic length of Pinus pinaster Ait. and the genetic length of chromosome Ⅵ of Oryza sativa L. were estimated from partial linkage data.

  5. Genomics for Weed Science

    Science.gov (United States)

    Numerous genomic-based studies have provided insight to the physiological and evolutionary processes involved in developmental and environmental processes of model plants such as arabidopsis and rice. However, far fewer efforts have been attempted to use genomic resources to study physiological and ...

  6. Genetics and Genomics

    Science.gov (United States)

    Good progress is being made on genetics and genomics of sugar beet, however it is in process and the tools are now being generated and some results are being analyzed. The GABI BeetSeq project released a first draft of the sugar beet genome of KWS2320, a dihaploid (see http://bvseq.molgen.mpg.de/Gen...

  7. Unlocking the bovine genome

    Science.gov (United States)

    The draft genome sequence of cattle (Bos taurus) has now been analyzed by the Bovine Genome Sequencing and Analysis Consortium and the Bovine HapMap Consortium, which together represent an extensive collaboration involving more than 300 scientists from 25 different countries. ...

  8. Safeguarding genome integrity

    DEFF Research Database (Denmark)

    Sørensen, Claus Storgaard; Syljuåsen, Randi G

    2012-01-01

    Mechanisms that preserve genome integrity are highly important during the normal life cycle of human cells. Loss of genome protective mechanisms can lead to the development of diseases such as cancer. Checkpoint kinases function in the cellular surveillance pathways that help cells to cope with DNA...

  9. National Human Genome Research Institute

    Science.gov (United States)

    ... Director Organization Reports & Publications Español The National Human Genome Research Institute conducts genetic and genomic research, funds ... study, led by researchers at the National Human Genome Research Institute and the Eunice Kennedy Shriver National ...

  10. Genomic Prediction in Barley

    DEFF Research Database (Denmark)

    Edriss, Vahid; Cericola, Fabio; Jensen, Jens D;

    Genomic prediction uses markers (SNPs) across the whole genome to predict individual breeding values at an early growth stage potentially before large scale phenotyping. One of the applications of genomic prediction in plant breeding is to identify the best individual candidate lines to contribute...... to next generation. The main goal of this study was to see the potential of using genomic prediction in a commercial Barley breeding program. The data used in this study was from Nordic Seed company which is located in Denmark. Around 350 advanced lines were genotyped with 9K Barely chip from...... Illumina. Traits used in this study were grain yield, plant height and heading date. Heading date is number days it takes after 1st June for plant to head. Heritabilities were 0.33, 0.44 and 0.48 for yield, height and heading, respectively for the average of nine plots. The GBLUP model was used for genomic...

  11. Genomic Prediction in Barley

    DEFF Research Database (Denmark)

    Edriss, Vahid; Cericola, Fabio; Jensen, Jens D;

    2015-01-01

    Genomic prediction uses markers (SNPs) across the whole genome to predict individual breeding values at an early growth stage potentially before large scale phenotyping. One of the applications of genomic prediction in plant breeding is to identify the best individual candidate lines to contribute...... to next generation. The main goal of this study was to see the potential of using genomic prediction in a commercial Barley breeding program. The data used in this study was from Nordic Seed company which is located in Denmark. Around 350 advanced lines were genotyped with 9K Barely chip from...... Illumina. Traits used in this study were grain yield, plant height and heading date. Heading date is number days it takes after 1st June for plant to head. Heritabilities were 0.33, 0.44 and 0.48 for yield, height and heading, respectively for the average of nine plots. The GBLUP model was used for genomic...

  12. 产AmpC酶弗劳地枸橼酸杆菌的耐药基因研究%Study on resistance gene of AmpC β-lactamase in Citrobacter freundii

    Institute of Scientific and Technical Information of China (English)

    曾红莲; 赵东明; 徐韫健; 张晓坤

    2011-01-01

    Aim To investigate the drug resistance gene of AmpC β-Lactamase from ten Citrobacter freundii.Methods -lactamases of ten strains was extracted by ultrasonic crushing,and AmpC -lactamases was tested with Cefoxitin in three dimensional test,the genotype of AmpC were amplified by multiple PCR and PCR products were sequenced subsequently. Drug sensitivity of ten strains were determined. Results There were 4 strains positive in three-dimensional test.The genotype of β-lactamases were not detected in CMY-G1 (1/10),CMY-G2 (2/10),FOX (1/10),CIT(2/10),ACT,DHA and MOX genes in ten strains. The 1 146bp DNA fragment of CMY-type AmpC β-Lactamase gene sequence shared 99 % amino acid identity with blaCMY that already appeared in Guangzhou. The resistant strains overexpressing AmpC β-lactamases were multi-drug resistant. Conclusion The surveillance of overexpressing AmpC β-lactamases in Citrobacter freundii should be emphasized so as to choose effective antibiotic for dealing with AmpC β-lactamases producing strains.%目的 对广州医学院第一附属医院临床分离的10株弗劳地枸橼酸杆菌进行AmpC酶的耐药基因研究.方法 用超声破碎法提取10株菌的β-内酰胺酶粗提物,进行三维试验;提取10株细菌的总DNA,PCR扩增CMY-G1、CMY-G2、FOX、ACT、DHA、MOX、CIT耐药基因并进行测序;对菌株进行MIC药物敏感试验.结果 三维试验阳性的有4株,β-内酰胺酶基因的检出率:CMY-G1(1/10)、CMY-G2(2/10)、FOX(1/10)、CIT(2/10),ACT、DHA和MOX未检出;CMY基因经全序列测定得到1 146bp的基因片段,与广州地区报道的CMY基因有99%同源;AmpC酶阳性的菌株茵呈多重耐药现象.结论 加强菌弗劳地枸橼酸杆菌产AmpC酶的监测,以选择合适的抗生素应对产酶株.

  13. Correlation between integron and drug-resistance in clinical isolates of Citrobacter freundii%弗氏柠檬酸杆菌临床分离株整合子与耐药相关性的研究

    Institute of Scientific and Technical Information of China (English)

    俞燕; 魏取好; 王卫忠

    2013-01-01

    目的 了解临床分离弗氏柠檬酸杆菌中整合子的分布,分析整合子与细菌耐药性的关系.方法 选取2011年7月至2013年2月非重复分离自浙江省人民医院就诊患者临床样本中的37株弗氏柠檬酸杆菌,用聚合酶链反应(PCR)检测菌株第Ⅰ、Ⅱ、Ⅲ类整合子.抗生素药敏试验采用微量肉汤稀释法.结果 37株弗氏柠檬酸杆菌中,有14株(37.8%)检测到第Ⅰ类整合子,未检出第Ⅱ类和第Ⅲ类整合子.对15种常用抗生素的耐药性检测显示,第Ⅰ类整合子阳性菌株对复方磺胺甲(噁)唑及环丙沙星的耐药率高于第Ⅰ类整合子阴性菌株(P均<0.05);对其他抗生素的耐药性,第Ⅰ类整合子阳性和阴性菌株间差异无统计学意义(P均>0.05).结论 第Ⅰ类整合子在弗氏柠檬酸杆菌中分布普遍.第Ⅰ类整合子与复方磺胺甲(噁)唑及环丙沙星的耐药性密切相关.%Objective To investigate the distribution of integrons in clinical Citrobacterfreundii strains and analyze the relationship between integrons and antibiotic resistance.Methods A total of 37 non-repeated clinical isolates of Citrobacter freundii from Zhejiang Provincial People's Hospital were selected from July 2011 to February 2013.The types of the interons(intIl、intI2、intI3) were identified by PCR and the drug-sensitivity tests were carried out by broth dilution method.Results Among 37 non-repeated isolates of Citrobacter freundii,intIl was detected in 14 isolates (37.8 %),intI2 and intI3 genes were not detected.After drug-resistance test of 15 common used antibiotics,the intI1-positive strains showed higher resistant rates of trimethoprim-sulfamethoxazole and ciprofloxacin than the intIl-negative strains (P all < 0.05).For resistance rates of the other antibiotics,there was no difference between theintIl-positive and intIl-negative strains(P all > 0.05).Conclusions In this study,the class Ⅰ integron is extensively found in clinical isolates

  14. Screening of Lipase-Producing Bacteria and Conditions Optimization of Lipase Production by Citrobacter sp.%产脂肪酶菌株筛选及柠檬酸杆菌产酶条件优化

    Institute of Scientific and Technical Information of China (English)

    张晶晶; 刘金峰; 牟伯中; 杨世忠

    2015-01-01

    脂肪酶可以催化甘油三酯水解成脂肪酸和甘油,已广泛应用在工业领域,而获得产酶微生物是研究的基础。采用油脂平板法筛选出1株脂肪酶产生菌。经16S rRNA 序列分析可知,该菌株属于柠檬酸杆菌(Citrobacter werkman and Gillen)。单因素试验对其进行产酶条件优化,优化后产酶条件(g/ L):淀粉2.0,KH2 PO41.0,K2 HPO4·3H2 O 2.2,(NH4)2 SO41.0,MgSO4·7H2 O 0.1,牛肉膏2.0,橄榄油10.0 mL,pH 7.5,每升接种量为15 mL,37℃培养43 h。获得最大酶活为384 U/ mL,是优化前的13倍。可以利用该菌制备脂肪酶。%Lipase can catalyze hydrolysis of triglyceride into fatty acids and glycerol,and has been widely applied in industries,and to obtain lipase-producing microorganisms is the basis of the study. A novel lipase-producing microbe was isolated from lipid-contaminated soil samples using plate-screening method. It was purified and identified as Citrobacter sp. through 16S rRNA sequence analysis. The enzyme production condition was optimized by single factor experiment. The optimum culture condition in a liter medium was 2. 0(g/ L,the same below)of soluble starch,1. 0 KH2 PO4 ,2. 2 K2 HPO4 ·3H2 O,1. 0(NH4 )2 SO4 ,0. 1 MgSO4 ·7H2 O,2. 0 beef extract,olive oil 10. 0 mL,pH 7. 5 and 15 mL of inoculum,culture for 43 h at 37 °C in shaker. The obtained enzymatic activity was 384 U/ mL at the highest,and it was 13-fold of that before the optimization. This strain could be used to produce lipase.

  15. Screening of Lipase-Producing Bacteria and Conditions Optimization of Lipase Production by Citrobacter sp.%产脂肪酶菌株筛选及柠檬酸杆菌产酶条件优化

    Institute of Scientific and Technical Information of China (English)

    张晶晶; 刘金峰; 牟伯中; 杨世忠

    2015-01-01

    Lipase can catalyze hydrolysis of triglyceride into fatty acids and glycerol,and has been widely applied in industries,and to obtain lipase-producing microorganisms is the basis of the study. A novel lipase-producing microbe was isolated from lipid-contaminated soil samples using plate-screening method. It was purified and identified as Citrobacter sp. through 16S rRNA sequence analysis. The enzyme production condition was optimized by single factor experiment. The optimum culture condition in a liter medium was 2. 0(g/ L,the same below)of soluble starch,1. 0 KH2 PO4 ,2. 2 K2 HPO4 ·3H2 O,1. 0(NH4 )2 SO4 ,0. 1 MgSO4 ·7H2 O,2. 0 beef extract,olive oil 10. 0 mL,pH 7. 5 and 15 mL of inoculum,culture for 43 h at 37 °C in shaker. The obtained enzymatic activity was 384 U/ mL at the highest,and it was 13-fold of that before the optimization. This strain could be used to produce lipase.%脂肪酶可以催化甘油三酯水解成脂肪酸和甘油,已广泛应用在工业领域,而获得产酶微生物是研究的基础。采用油脂平板法筛选出1株脂肪酶产生菌。经16S rRNA 序列分析可知,该菌株属于柠檬酸杆菌(Citrobacter werkman and Gillen)。单因素试验对其进行产酶条件优化,优化后产酶条件(g/ L):淀粉2.0,KH2 PO41.0,K2 HPO4·3H2 O 2.2,(NH4)2 SO41.0,MgSO4·7H2 O 0.1,牛肉膏2.0,橄榄油10.0 mL,pH 7.5,每升接种量为15 mL,37℃培养43 h。获得最大酶活为384 U/ mL,是优化前的13倍。可以利用该菌制备脂肪酶。

  16. Phytozome Comparative Plant Genomics Portal

    Energy Technology Data Exchange (ETDEWEB)

    Goodstein, David; Batra, Sajeev; Carlson, Joseph; Hayes, Richard; Phillips, Jeremy; Shu, Shengqiang; Schmutz, Jeremy; Rokhsar, Daniel

    2014-09-09

    The Dept. of Energy Joint Genome Institute is a genomics user facility supporting DOE mission science in the areas of Bioenergy, Carbon Cycling, and Biogeochemistry. The Plant Program at the JGI applies genomic, analytical, computational and informatics platforms and methods to: 1. Understand and accelerate the improvement (domestication) of bioenergy crops 2. Characterize and moderate plant response to climate change 3. Use comparative genomics to identify constrained elements and infer gene function 4. Build high quality genomic resource platforms of JGI Plant Flagship genomes for functional and experimental work 5. Expand functional genomic resources for Plant Flagship genomes

  17. Detection of an IncA/C plasmid encoding VIM-4 and CMY-4 β-lactamases in Klebsiella oxytoca and Citrobacter koseri from an inpatient in a cardiac rehabilitation unit.

    Science.gov (United States)

    Caltagirone, Mariasofia; Bitar, Ibrahim; Piazza, Aurora; Spalla, Melissa; Nucleo, Elisabetta; Navarra, Antonella; Migliavacca, Roberta

    2015-07-01

    A 62-year-old patient was transferred to the cardiac rehabilitation unit of the I.R.C.C.S. Fondazione S. Maugeri after undergoing a heart transplantation at the Acute Care Hospital I.R.C.C.S. S. Matteo of Pavia. On 1 August 2013 and during hospitalization in the rehabilitation unit, Klebsiella oxytoca and Citrobacter koseri clinical isolates were simultaneously recovered from the patient's preputial swab. Both the K. oxytoca and C. koseri strains were carbapenem- resistant by MicroScan System (Beckman Coulter). Carbapenem-resistant K. pneumoniae had previously been reported in the same rehabilitation facility. The aim of the study was to identify the carbapenem resistance mechanisms among the enterobacterial species recovered. Phenotypic screening tests useful to detect the β-lactamases/carbapenemases were performed. Carbapenem MICs were obtained by Etest. AmpC and MBL encoding genes were identified by PCR and sequencing. Conjugation assays and plasmid characterization were performed. Both of the K. oxytoca and C. koseri isolates were multi drug resistant, showing resistance to amoxicillin-clavulanic acid, three generation cephalosporins, ertapenem (K. oxytoca MIC, >32 mg/L; C. koseri MIC, 4 mg/L), imipenem (K. oxytoca MIC, 4 mg/L; C. koseri MIC, 12 mg/L), thrimethoprim sulphamethoxazole and gentamicin. Susceptibility was retained to fluoroquinolones, colistin and tigecycline. Molecular characterization confirmed the co-presence of blaCMY-4 and blaVIM-4 determinants in a 150 Kb transferable plasmid of IncA/C group. This case is the first detection in Italy of the K. oxytoca and C. koseri clinical isolates co-producing the CMY-4 and VIM-4 enzymes.

  18. Secondary metabolites extracted from marine sponge associated Comamonas testosteroni and Citrobacter freundii as potential antimicrobials against MDR pathogens and hypothetical leads for VP40 matrix protein of Ebola virus: an in vitro and in silico investigation.

    Science.gov (United States)

    Skariyachan, Sinosh; Acharya, Archana B; Subramaniyan, Saumya; Babu, Sumangala; Kulkarni, Shruthi; Narayanappa, Rajeswari

    2016-09-01

    The current study explores therapeutic potential of metabolites extracted from marine sponge (Cliona sp.)-associated bacteria against MDR pathogens and predicts the binding prospective of probable lead molecules against VP40 target of Ebola virus. The metabolite-producing bacteria were characterized by agar overlay assay and as per the protocols in Bergey's manual of determinative bacteriology. The antibacterial activities of extracted metabolites were tested against clinical pathogens by well-diffusion assay. The selected metabolite producers were characterized by 16S rDNA sequencing. Chemical screening and Fourier Transform Infrared (FTIR) analysis for selected compounds were performed. The probable lead molecules present in the metabolites were hypothesized based on proximate analysis, FTIR data, and literature survey. The drug-like properties and binding potential of lead molecules against VP40 target of Ebola virus were hypothesized by computational virtual screening and molecular docking. The current study demonstrated that clear zones around bacterial colonies in agar overlay assay. Antibiotic sensitivity profiling demonstrated that the clinical isolates were multi-drug resistant, however; most of them showed sensitivity to secondary metabolites (MIC-15 μl/well). The proximate and FTIR analysis suggested that probable metabolites belonged to alkaloids with O-H, C-H, C=O, and N-H groups. 16S rDNA characterization of selected metabolite producers demonstrated that 96% and 99% sequence identity to Comamonas testosteroni and Citrobacter freundii, respectively. The docking studies suggested that molecules such as Gymnastatin, Sorbicillactone, Marizomib, and Daryamide can designed as probable lead candidates against VP40 target of Ebola virus. PMID:26577929

  19. Secondary metabolites extracted from marine sponge associated Comamonas testosteroni and Citrobacter freundii as potential antimicrobials against MDR pathogens and hypothetical leads for VP40 matrix protein of Ebola virus: an in vitro and in silico investigation.

    Science.gov (United States)

    Skariyachan, Sinosh; Acharya, Archana B; Subramaniyan, Saumya; Babu, Sumangala; Kulkarni, Shruthi; Narayanappa, Rajeswari

    2016-09-01

    The current study explores therapeutic potential of metabolites extracted from marine sponge (Cliona sp.)-associated bacteria against MDR pathogens and predicts the binding prospective of probable lead molecules against VP40 target of Ebola virus. The metabolite-producing bacteria were characterized by agar overlay assay and as per the protocols in Bergey's manual of determinative bacteriology. The antibacterial activities of extracted metabolites were tested against clinical pathogens by well-diffusion assay. The selected metabolite producers were characterized by 16S rDNA sequencing. Chemical screening and Fourier Transform Infrared (FTIR) analysis for selected compounds were performed. The probable lead molecules present in the metabolites were hypothesized based on proximate analysis, FTIR data, and literature survey. The drug-like properties and binding potential of lead molecules against VP40 target of Ebola virus were hypothesized by computational virtual screening and molecular docking. The current study demonstrated that clear zones around bacterial colonies in agar overlay assay. Antibiotic sensitivity profiling demonstrated that the clinical isolates were multi-drug resistant, however; most of them showed sensitivity to secondary metabolites (MIC-15 μl/well). The proximate and FTIR analysis suggested that probable metabolites belonged to alkaloids with O-H, C-H, C=O, and N-H groups. 16S rDNA characterization of selected metabolite producers demonstrated that 96% and 99% sequence identity to Comamonas testosteroni and Citrobacter freundii, respectively. The docking studies suggested that molecules such as Gymnastatin, Sorbicillactone, Marizomib, and Daryamide can designed as probable lead candidates against VP40 target of Ebola virus.

  20. Genome instability and aging.

    Science.gov (United States)

    Vijg, Jan; Suh, Yousin

    2013-01-01

    Genome instability has long been implicated as the main causal factor in aging. Somatic cells are continuously exposed to various sources of DNA damage, from reactive oxygen species to UV radiation to environmental mutagens. To cope with the tens of thousands of chemical lesions introduced into the genome of a typical cell each day, a complex network of genome maintenance systems acts to remove damage and restore the correct base pair sequence. Occasionally, however, repair is erroneous, and such errors, as well as the occasional failure to correctly replicate the genome during cell division, are the basis for mutations and epimutations. There is now ample evidence that mutations accumulate in various organs and tissues of higher animals, including humans, mice, and flies. What is not known, however, is whether the frequency of these random changes is sufficient to cause the phenotypic effects generally associated with aging. The exception is cancer, an age-related disease caused by the accumulation of mutations and epimutations. Here, we first review current concepts regarding the relationship between DNA damage, repair, and mutation, as well as the data regarding genome alterations as a function of age. We then describe a model for how randomly induced DNA sequence and epigenomic variants in the somatic genomes of animals can result in functional decline and disease in old age. Finally, we discuss the genetics of genome instability in relation to longevity to address the importance of alterations in the somatic genome as a causal factor in aging and to underscore the opportunities provided by genetic approaches to develop interventions that attenuate genome instability, reduce disease risk, and increase life span. PMID:23398157

  1. Center for Cancer Genomics | Office of Cancer Genomics

    Science.gov (United States)

    The Center for Cancer Genomics (CCG) was established to unify the National Cancer Institute's activities in cancer genomics, with the goal of advancing genomics research and translating findings into the clinic to improve the precise diagnosis and treatment of cancers. In addition to promoting genomic sequencing approach

  2. Human Genome Project

    Energy Technology Data Exchange (ETDEWEB)

    Block, S. [The MITRE Corporation, McLean, VA (US). JASON Program Office; Cornwall, J. [The MITRE Corporation, McLean, VA (US). JASON Program Office; Dally, W. [The MITRE Corporation, McLean, VA (US). JASON Program Office; Dyson, F. [The MITRE Corporation, McLean, VA (US). JASON Program Office; Fortson, N. [The MITRE Corporation, McLean, VA (US). JASON Program Office; Joyce, G. [The MITRE Corporation, McLean, VA (US). JASON Program Office; Kimble, H. J. [The MITRE Corporation, McLean, VA (US). JASON Program Office; Lewis, N. [The MITRE Corporation, McLean, VA (US). JASON Program Office; Max, C. [The MITRE Corporation, McLean, VA (US). JASON Program Office; Prince, T. [The MITRE Corporation, McLean, VA (US). JASON Program Office; Schwitters, R. [The MITRE Corporation, McLean, VA (US). JASON Program Office; Weinberger, P. [The MITRE Corporation, McLean, VA (US). JASON Program Office; Woodin, W. H. [The MITRE Corporation, McLean, VA (US). JASON Program Office

    1998-01-04

    The study reviews Department of Energy supported aspects of the United States Human Genome Project, the joint National Institutes of Health/Department of Energy program to characterize all human genetic material, to discover the set of human genes, and to render them accessible for further biological study. The study concentrates on issues of technology, quality assurance/control, and informatics relevant to current effort on the genome project and needs beyond it. Recommendations are presented on areas of the genome program that are of particular interest to and supported by the Department of Energy.

  3. Genomic taxonomy of vibrios

    Directory of Open Access Journals (Sweden)

    Iida Tetsuya

    2009-10-01

    Full Text Available Abstract Background Vibrio taxonomy has been based on a polyphasic approach. In this study, we retrieve useful taxonomic information (i.e. data that can be used to distinguish different taxonomic levels, such as species and genera from 32 genome sequences of different vibrio species. We use a variety of tools to explore the taxonomic relationship between the sequenced genomes, including Multilocus Sequence Analysis (MLSA, supertrees, Average Amino Acid Identity (AAI, genomic signatures, and Genome BLAST atlases. Our aim is to analyse the usefulness of these tools for species identification in vibrios. Results We have generated four new genome sequences of three Vibrio species, i.e., V. alginolyticus 40B, V. harveyi-like 1DA3, and V. mimicus strains VM573 and VM603, and present a broad analyses of these genomes along with other sequenced Vibrio species. The genome atlas and pangenome plots provide a tantalizing image of the genomic differences that occur between closely related sister species, e.g. V. cholerae and V. mimicus. The vibrio pangenome contains around 26504 genes. The V. cholerae core genome and pangenome consist of 1520 and 6923 genes, respectively. Pangenomes might allow different strains of V. cholerae to occupy different niches. MLSA and supertree analyses resulted in a similar phylogenetic picture, with a clear distinction of four groups (Vibrio core group, V. cholerae-V. mimicus, Aliivibrio spp., and Photobacterium spp.. A Vibrio species is defined as a group of strains that share > 95% DNA identity in MLSA and supertree analysis, > 96% AAI, ≤ 10 genome signature dissimilarity, and > 61% proteome identity. Strains of the same species and species of the same genus will form monophyletic groups on the basis of MLSA and supertree. Conclusion The combination of different analytical and bioinformatics tools will enable the most accurate species identification through genomic computational analysis. This endeavour will culminate in

  4. Genomic signal processing

    CERN Document Server

    Shmulevich, Ilya

    2007-01-01

    Genomic signal processing (GSP) can be defined as the analysis, processing, and use of genomic signals to gain biological knowledge, and the translation of that knowledge into systems-based applications that can be used to diagnose and treat genetic diseases. Situated at the crossroads of engineering, biology, mathematics, statistics, and computer science, GSP requires the development of both nonlinear dynamical models that adequately represent genomic regulation, and diagnostic and therapeutic tools based on these models. This book facilitates these developments by providing rigorous mathema

  5. Human Genome Program

    Energy Technology Data Exchange (ETDEWEB)

    1993-01-01

    The DOE Human Genome program has grown tremendously, as shown by the marked increase in the number of genome-funded projects since the last workshop held in 1991. The abstracts in this book describe the genome research of DOE-funded grantees and contractors and invited guests, and all projects are represented at the workshop by posters. The 3-day meeting includes plenary sessions on ethical, legal, and social issues pertaining to the availability of genetic data; sequencing techniques, informatics support; and chromosome and cDNA mapping and sequencing.

  6. Genomic taxonomy of vibrios

    DEFF Research Database (Denmark)

    Thompson, Cristiane C.; Vicente, Ana Carolina P.; Souza, Rangel C.;

    2009-01-01

    BACKGROUND: Vibrio taxonomy has been based on a polyphasic approach. In this study, we retrieve useful taxonomic information (i.e. data that can be used to distinguish different taxonomic levels, such as species and genera) from 32 genome sequences of different vibrio species. We use a variety...... analytical and bioinformatics tools will enable the most accurate species identification through genomic computational analysis. This endeavour will culminate in the birth of the online genomic taxonomy whereby researchers and end-users of taxonomy will be able to identify their isolates through a web...

  7. The Genome Atlas Resource

    DEFF Research Database (Denmark)

    Azam Qureshi, Matloob; Rotenberg, Eva; Stærfeldt, Hans Henrik;

    2010-01-01

    Abstract. The Genome Atlas is a resource for addressing the challenges of synchronising prokaryotic genomic sequence data from multiple public repositories. This resource can integrate bioinformatic analyses in various data format and quality. Existing open source tools have been used together...... with scripts and algorithms developed in a variety of programming languages at the Centre for Biological Sequence Analysis in order to create a three-tier software application for genome analysis. The results are made available via a web interface developed in Java, PHP and Perl CGI. User...

  8. Genome-specificity of triplet periodicity of prokaryotic genomes

    International Nuclear Information System (INIS)

    Authors have found that triplet periodicity (TP) is more similar inside genome than between genomes and that TP distribution inside genome corresponds to hypothesis which imply common TP pattern for majority of sequences inside a genome. To test the specificity of TP, the classification of the gene has been carried out to detect the belonging to one genome of the pair. For most pairs, the classification accuracy was more than 85%

  9. Lophotrochozoan mitochondrial genomes

    Energy Technology Data Exchange (ETDEWEB)

    Valles, Yvonne; Boore, Jeffrey L.

    2005-10-01

    Progress in both molecular techniques and phylogeneticmethods has challenged many of the interpretations of traditionaltaxonomy. One example is in the recognition of the animal superphylumLophotrochozoa (annelids, mollusks, echiurans, platyhelminthes,brachiopods, and other phyla), although the relationships within thisgroup and the inclusion of some phyla remain uncertain. While much ofthis progress in phylogenetic reconstruction has been based on comparingsingle gene sequences, we are beginning to see the potential of comparinglarge-scale features of genomes, such as the relative order of genes.Even though tremendous progress is being made on the sequencedetermination of whole nuclear genomes, the dataset of choice forgenome-level characters for many animals across a broad taxonomic rangeremains mitochondrial genomes. We review here what is known aboutmitochondrial genomes of the lophotrochozoans and discuss the promisethat this dataset will enable insight into theirrelationships.

  10. The genomics of adaptation.

    Science.gov (United States)

    Radwan, Jacek; Babik, Wiesław

    2012-12-22

    The amount and nature of genetic variation available to natural selection affect the rate, course and outcome of evolution. Consequently, the study of the genetic basis of adaptive evolutionary change has occupied biologists for decades, but progress has been hampered by the lack of resolution and the absence of a genome-level perspective. Technological advances in recent years should now allow us to answer many long-standing questions about the nature of adaptation. The data gathered so far are beginning to challenge some widespread views of the way in which natural selection operates at the genomic level. Papers in this Special Feature of Proceedings of the Royal Society B illustrate various aspects of the broad field of adaptation genomics. This introductory article sets up a context and, on the basis of a few selected examples, discusses how genomic data can advance our understanding of the process of adaptation.

  11. Epidemiology & Genomics Research Program

    Science.gov (United States)

    The Epidemiology and Genomics Research Program, in the National Cancer Institute's Division of Cancer Control and Population Sciences, funds research in human populations to understand the determinants of cancer occurrence and outcomes.

  12. The genomics of adaptation.

    Science.gov (United States)

    Radwan, Jacek; Babik, Wiesław

    2012-12-22

    The amount and nature of genetic variation available to natural selection affect the rate, course and outcome of evolution. Consequently, the study of the genetic basis of adaptive evolutionary change has occupied biologists for decades, but progress has been hampered by the lack of resolution and the absence of a genome-level perspective. Technological advances in recent years should now allow us to answer many long-standing questions about the nature of adaptation. The data gathered so far are beginning to challenge some widespread views of the way in which natural selection operates at the genomic level. Papers in this Special Feature of Proceedings of the Royal Society B illustrate various aspects of the broad field of adaptation genomics. This introductory article sets up a context and, on the basis of a few selected examples, discusses how genomic data can advance our understanding of the process of adaptation. PMID:23097510

  13. The genome editing revolution

    DEFF Research Database (Denmark)

    Stella, Stefano; Montoya, Guillermo

    2016-01-01

    the previously available DNA binding templates, zinc fingers and meganucleases. Recently, the area experimented a quantum leap because of the introduction of the clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein (Cas) system (clustered regularly interspaced short palindromic...... sequence). This ribonucleoprotein complex protects bacteria from invading DNAs, and it was adapted to be used in genome editing. The CRISPR ribonucleic acid (RNA) molecule guides to the specific DNA site the Cas9 nuclease to cleave the DNA target. Two years and more than 1000 publications later, the CRISPR......-Cas system has become the main tool for genome editing in many laboratories. Currently the targeted genome editing technology has been used in many fields and may be a possible approach for human gene therapy. Furthermore, it can also be used to modifying the genomes of model organisms for studying human...

  14. Yeast genome sequencing:

    DEFF Research Database (Denmark)

    Piskur, Jure; Langkjær, Rikke Breinhold

    2004-01-01

    For decades, unicellular yeasts have been general models to help understand the eukaryotic cell and also our own biology. Recently, over a dozen yeast genomes have been sequenced, providing the basis to resolve several complex biological questions. Analysis of the novel sequence data has shown...... of closely related species helps in gene annotation and to answer how many genes there really are within the genomes. Analysis of non-coding regions among closely related species has provided an example of how to determine novel gene regulatory sequences, which were previously difficult to analyse because...... they are short and degenerate and occupy different positions. Comparative genomics helps to understand the origin of yeasts and points out crucial molecular events in yeast evolutionary history, such as whole-genome duplication and horizontal gene transfer(s). In addition, the accumulating sequence data provide...

  15. Mouse genome database 2016.

    Science.gov (United States)

    Bult, Carol J; Eppig, Janan T; Blake, Judith A; Kadin, James A; Richardson, Joel E

    2016-01-01

    The Mouse Genome Database (MGD; http://www.informatics.jax.org) is the primary community model organism database for the laboratory mouse and serves as the source for key biological reference data related to mouse genes, gene functions, phenotypes and disease models with a strong emphasis on the relationship of these data to human biology and disease. As the cost of genome-scale sequencing continues to decrease and new technologies for genome editing become widely adopted, the laboratory mouse is more important than ever as a model system for understanding the biological significance of human genetic variation and for advancing the basic research needed to support the emergence of genome-guided precision medicine. Recent enhancements to MGD include new graphical summaries of biological annotations for mouse genes, support for mobile access to the database, tools to support the annotation and analysis of sets of genes, and expanded support for comparative biology through the expansion of homology data.

  16. Mouse Genome Informatics (MGI)

    Data.gov (United States)

    U.S. Department of Health & Human Services — MGI is the international database resource for the laboratory mouse, providing integrated genetic, genomic, and biological data to facilitate the study of human...

  17. The Lotus japonicus genome

    DEFF Research Database (Denmark)

    This book provides insights into some of the key achievements made in the study of Lotus japonicus (birdsfoot trefoil), as well as a timely overview of topics that are pertinent for future developments in legume genomics. Key topics covered include endosymbiosis, development, hormone regulation......, carbon/nitrogen and secondary metabolism, as well as advances made in high-throughput genomic and genetic approaches. Research focusing on model plants has underpinned the recent growth in plant genomics and genetics and provided a basis for investigations of major crop species. In the legume family...... Fabaceae, groundbreaking genetic and genomic research has established a significant body of knowledge on Lotus japonicus, which was adopted as a model species more than 20 years ago. The diverse nature of legumes means that such research has a wide potential and agricultural impact, for example...

  18. Genetical Genomics for Evolutionary Studies

    NARCIS (Netherlands)

    Prins, J.C.P.; Smant, G.; Jansen, R.C.

    2012-01-01

    enetical genomics combines acquired high-throughput genomic data with genetic analysis. In this chapter, we discuss the application of genetical genomics for evolutionary studies, where new high-throughput molecular technologies are combined with mapping quantitative trait loci (QTL) on the genome i

  19. An Introduction to Genome Annotation.

    Science.gov (United States)

    Campbell, Michael S; Yandell, Mark

    2015-12-17

    Genome projects have evolved from large international undertakings to tractable endeavors for a single lab. Accurate genome annotation is critical for successful genomic, genetic, and molecular biology experiments. These annotations can be generated using a number of approaches and available software tools. This unit describes methods for genome annotation and a number of software tools commonly used in gene annotation.

  20. Molluscan Evolutionary Genomics

    Energy Technology Data Exchange (ETDEWEB)

    Simison, W. Brian; Boore, Jeffrey L.

    2005-12-01

    In the last 20 years there have been dramatic advances in techniques of high-throughput DNA sequencing, most recently accelerated by the Human Genome Project, a program that has determined the three billion base pair code on which we are based. Now this tremendous capability is being directed at other genome targets that are being sampled across the broad range of life. This opens up opportunities as never before for evolutionary and organismal biologists to address questions of both processes and patterns of organismal change. We stand at the dawn of a new 'modern synthesis' period, paralleling that of the early 20th century when the fledgling field of genetics first identified the underlying basis for Darwin's theory. We must now unite the efforts of systematists, paleontologists, mathematicians, computer programmers, molecular biologists, developmental biologists, and others in the pursuit of discovering what genomics can teach us about the diversity of life. Genome-level sampling for mollusks to date has mostly been limited to mitochondrial genomes and it is likely that these will continue to provide the best targets for broad phylogenetic sampling in the near future. However, we are just beginning to see an inroad into complete nuclear genome sequencing, with several mollusks and other eutrochozoans having been selected for work about to begin. Here, we provide an overview of the state of molluscan mitochondrial genomics, highlight a few of the discoveries from this research, outline the promise of broadening this dataset, describe upcoming projects to sequence whole mollusk nuclear genomes, and challenge the community to prepare for making the best use of these data.

  1. The human genome project

    International Nuclear Information System (INIS)

    The Human Genome Project is a massive international research project, costing 3 to 5 billion dollars and expected to take 15 years, which will identify the all the genes in the human genome - i.e. the complete sequence of bases in human DNA. The prize will be the ability to identify genes causing or predisposing to disease, and in some cases the development of gene therapy, but this new knowledge will raise important ethical issues

  2. Cryptosporidium parvum Genome Project

    OpenAIRE

    Abrahamsen, Mitchell S.

    2001-01-01

    A lack of basic understanding of parasite biology has been a limiting factor in designing effective means of treating and preventing disease caused by Cryptosporidium parvum. Since the genomic DNA sequence encodes all of the heritable information responsible for development, disease pathogenesis, virulence, species permissiveness and immune resistance, a comprehensive knowledge of the C. parvum genome will provide the necessary information required for cost-effective and target...

  3. Decoding the human genome

    CERN Document Server

    CERN. Geneva. Audiovisual Unit; Antonerakis, S E

    2002-01-01

    Decoding the Human genome is a very up-to-date topic, raising several questions besides purely scientific, in view of the two competing teams (public and private), the ethics of using the results, and the fact that the project went apparently faster and easier than expected. The lecture series will address the following chapters: Scientific basis and challenges. Ethical and social aspects of genomics.

  4. Human Genome Annotation

    Science.gov (United States)

    Gerstein, Mark

    A central problem for 21st century science is annotating the human genome and making this annotation useful for the interpretation of personal genomes. My talk will focus on annotating the 99% of the genome that does not code for canonical genes, concentrating on intergenic features such as structural variants (SVs), pseudogenes (protein fossils), binding sites, and novel transcribed RNAs (ncRNAs). In particular, I will describe how we identify regulatory sites and variable blocks (SVs) based on processing next-generation sequencing experiments. I will further explain how we cluster together groups of sites to create larger annotations. Next, I will discuss a comprehensive pseudogene identification pipeline, which has enabled us to identify >10K pseudogenes in the genome and analyze their distribution with respect to age, protein family, and chromosomal location. Throughout, I will try to introduce some of the computational algorithms and approaches that are required for genome annotation. Much of this work has been carried out in the framework of the ENCODE, modENCODE, and 1000 genomes projects.

  5. Human social genomics.

    Directory of Open Access Journals (Sweden)

    Steven W Cole

    2014-08-01

    Full Text Available A growing literature in human social genomics has begun to analyze how everyday life circumstances influence human gene expression. Social-environmental conditions such as urbanity, low socioeconomic status, social isolation, social threat, and low or unstable social status have been found to associate with differential expression of hundreds of gene transcripts in leukocytes and diseased tissues such as metastatic cancers. In leukocytes, diverse types of social adversity evoke a common conserved transcriptional response to adversity (CTRA characterized by increased expression of proinflammatory genes and decreased expression of genes involved in innate antiviral responses and antibody synthesis. Mechanistic analyses have mapped the neural "social signal transduction" pathways that stimulate CTRA gene expression in response to social threat and may contribute to social gradients in health. Research has also begun to analyze the functional genomics of optimal health and thriving. Two emerging opportunities now stand to revolutionize our understanding of the everyday life of the human genome: network genomics analyses examining how systems-level capabilities emerge from groups of individual socially sensitive genomes and near-real-time transcriptional biofeedback to empirically optimize individual well-being in the context of the unique genetic, geographic, historical, developmental, and social contexts that jointly shape the transcriptional realization of our innate human genomic potential for thriving.

  6. Evolution of small prokaryotic genomes

    OpenAIRE

    Martínez-Cano, David J.; Reyes-Prieto, Mariana; Martínez-Romero, Esperanza; Partida-Martínez, Laila P.; Latorre, Amparo; Moya, Andrés; Delaye, Luis

    2015-01-01

    As revealed by genome sequencing, the biology of prokaryotes with reduced genomes is strikingly diverse. These include free-living prokaryotes with ∼800 genes as well as endosymbiotic bacteria with as few as ∼140 genes. Comparative genomics is revealing the evolutionary mechanisms that led to these small genomes. In the case of free-living prokaryotes, natural selection directly favored genome reduction, while in the case of endosymbiotic prokaryotes neutral processes played a more prominent ...

  7. Evolution of small prokaryotic genomes

    OpenAIRE

    David José Martínez-Cano; Mariana eReyes-Prieto; Esperanza eMartinez-Romero; Laila Pamela Partida-Martinez; Amparo eLatorre; Andres eMoya; Luis eDelaye

    2015-01-01

    As revealed by genome sequencing, the biology of prokaryotes with reduced genomes is strikingly diverse. These include free-living prokaryotes with ~800 genes as well as endosymbiotic bacteria with as few as ~140 genes. Comparative genomics is revealing the evolutionary mechanisms that led to these small genomes. In the case of free-living prokaryotes, natural selection directly favored genome reduction, while in the case of endosymbiotic prokaryotes neutral processes played a more prominent ...

  8. WheatGenome.info: A Resource for Wheat Genomics Resource.

    Science.gov (United States)

    Lai, Kaitao

    2016-01-01

    An integrated database with a variety of Web-based systems named WheatGenome.info hosting wheat genome and genomic data has been developed to support wheat research and crop improvement. The resource includes multiple Web-based applications, which are implemented as a variety of Web-based systems. These include a GBrowse2-based wheat genome viewer with BLAST search portal, TAGdb for searching wheat second generation genome sequence data, wheat autoSNPdb, links to wheat genetic maps using CMap and CMap3D, and a wheat genome Wiki to allow interaction between diverse wheat genome sequencing activities. This portal provides links to a variety of wheat genome resources hosted at other research organizations. This integrated database aims to accelerate wheat genome research and is freely accessible via the web interface at http://www.wheatgenome.info/ . PMID:26519407

  9. Rumen microbial genomics

    International Nuclear Information System (INIS)

    Full text: Improving plant cell wall (fiber) degradation remains one of the highest priority goals for all livestock enterprises, whether it is the intensively managed dairy herds in the United States, or the nomadic cattle herds in sub-Saharan Africa. The North American Consortium for Genomics of Fibrolytic Ruminal Bacteria was created in 2000 to promote the sequencing and comparative analysis of rumen microbial genomes. High throughput genome sequencing offers the potential to obtain a complete blueprint for the lifestyle of a specific microbe, and to assess its genetic potential in a functional and comparative fashion. So far, a combination of funds from U.S. Department of Agriculture's (USDA's) Initiative for Future Agriculture and Food Systems and the National Science Foundation (USDA-NSF) Microbe Sequencing Program has supported the sequencing of three rumen bacterial genomes to closure. Genome closure and annotation is complete for Fibrobacter succinogenes, and the Ruminococcus albus and Prevotella ruminicola genomes should be completed during 2004. In addition to these sequencing projects, Consortium members have used subtractive hybridization methods to characterize the genomic differences among the sequenced genomes and the genomes of additional strains and species of ruminal bacteria. A database has also been developed by bioinformaticians at The Institute for Genomic Research (www.tigr.org), which will contain the sequence information arising from this project, as well as in silico tools for genome examination. Accordingly, our Consortium will have provided a comprehensive suite of resources and tools useful to microbiologists and animal scientists throughout the world, especially those interested in the conversion of cellulose-rich materials into useful commodities, such as meat, milk and draught animal power. The inherent value associated with whole genome sequencing is already apparent for the F. succinogenes project. The genome sequence has revealed

  10. Genomes to Proteomes

    Energy Technology Data Exchange (ETDEWEB)

    Panisko, Ellen A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Grigoriev, Igor [USDOE Joint Genome Inst., Walnut Creek, CA (United States); Daly, Don S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Webb-Robertson, Bobbie-Jo [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Baker, Scott E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2009-03-01

    Biologists are awash with genomic sequence data. In large part, this is due to the rapid acceleration in the generation of DNA sequence that occurred as public and private research institutes raced to sequence the human genome. In parallel with the large human genome effort, mostly smaller genomes of other important model organisms were sequenced. Projects following on these initial efforts have made use of technological advances and the DNA sequencing infrastructure that was built for the human and other organism genome projects. As a result, the genome sequences of many organisms are available in high quality draft form. While in many ways this is good news, there are limitations to the biological insights that can be gleaned from DNA sequences alone; genome sequences offer only a bird's eye view of the biological processes endemic to an organism or community. Fortunately, the genome sequences now being produced at such a high rate can serve as the foundation for other global experimental platforms such as proteomics. Proteomic methods offer a snapshot of the proteins present at a point in time for a given biological sample. Current global proteomics methods combine enzymatic digestion, separations, mass spectrometry and database searching for peptide identification. One key aspect of proteomics is the prediction of peptide sequences from mass spectrometry data. Global proteomic analysis uses computational matching of experimental mass spectra with predicted spectra based on databases of gene models that are often generated computationally. Thus, the quality of gene models predicted from a genome sequence is crucial in the generation of high quality peptide identifications. Once peptides are identified they can be assigned to their parent protein. Proteins identified as expressed in a given experiment are most useful when compared to other expressed proteins in a larger biological context or biochemical pathway. In this chapter we will discuss the automatic

  11. Study on corrosion mechanism of Citrobacter freundii to HSn70-1AB copper alloy in reclaimed water%再生水中柠檬酸杆菌对铜合金腐蚀机理研究

    Institute of Scientific and Technical Information of China (English)

    张静

    2013-01-01

    With Citrobacter freundii in reclaimed water as the research object,the structure features of the biofilm on the surface of HSn70-1AB copper alloy was studied from aspects of micro-morphology characteristics,thermal analysis and so on using atomic force microscopy(AFM),contact angle measurement,scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS) and some other methods; meanwhile,the effect of hydrophobicity of the biofilm on its structure and the corrosion mechanism of HSn70-1AB copper alloy were also analyzed.The study results showed that,the uniformity of the said alloy gradually deteriorated along with the soaking time; benefited from the strong hydrophilicity,the whole structure of the biofilm was integrated at later stage; the corrosion of Citrobacterfreundii to HSn70-1AB was mainly represented as localized corrosion,especially pitting corrosion.%以再生水中弗氏柠檬酸杆菌为研究对象,采用原子力显微镜(AFM)、接触角测量仪、扫描电子显微镜(SEM)和能谱仪(EDS)等试验方法,从微观形貌表征、热力学分析等方面,研究了HSn70-1AB铜合金表面生物膜的结构特性,并分析了生物膜疏水性能对生物膜结构的影响以及生物膜下HSn70-1AB铜合金的腐蚀机理.研究结果显示,HSn70-1AB合金表面生物膜的均匀性随浸泡对间的延长而逐渐变差;较强的亲本性使得后期生物膜的整体结构比较完整;弗氏柠檬酸杆菌对HSn70-1AB主要以局部腐蚀为主,尤其是点蚀.

  12. Genome position specific priors for genomic prediction

    Directory of Open Access Journals (Sweden)

    Brøndum Rasmus

    2012-10-01

    Full Text Available Abstract Background The accuracy of genomic prediction is highly dependent on the size of the reference population. For small populations, including information from other populations could improve this accuracy. The usual strategy is to pool data from different populations; however, this has not proven as successful as hoped for with distantly related breeds. BayesRS is a novel approach to share information across populations for genomic predictions. The approach allows information to be captured even where the phase of SNP alleles and casuative mutation alleles are reversed across populations, or the actual casuative mutation is different between the populations but affects the same gene. Proportions of a four-distribution mixture for SNP effects in segments of fixed size along the genome are derived from one population and set as location specific prior proportions of distributions of SNP effects for the target population. The model was tested using dairy cattle populations of different breeds: 540 Australian Jersey bulls, 2297 Australian Holstein bulls and 5214 Nordic Holstein bulls. The traits studied were protein-, fat- and milk yield. Genotypic data was Illumina 777K SNPs, real or imputed. Results Results showed an increase in accuracy of up to 3.5% for the Jersey population when using BayesRS with a prior derived from Australian Holstein compared to a model without location specific priors. The increase in accuracy was however lower than was achieved when reference populations were combined to estimate SNP effects, except in the case of fat yield. The small size of the Jersey validation set meant that these improvements in accuracy were not significant using a Hotelling-Williams t-test at the 5% level. An increase in accuracy of 1-2% for all traits was observed in the Australian Holstein population when using a prior derived from the Nordic Holstein population compared to using no prior information. These improvements were significant (P

  13. Genomics of Salmonella Species

    Science.gov (United States)

    Canals, Rocio; McClelland, Michael; Santiviago, Carlos A.; Andrews-Polymenis, Helene

    Progress in the study of Salmonella survival, colonization, and virulence has increased rapidly with the advent of complete genome sequencing and higher capacity assays for transcriptomic and proteomic analysis. Although many of these techniques have yet to be used to directly assay Salmonella growth on foods, these assays are currently in use to determine Salmonella factors necessary for growth in animal models including livestock animals and in in vitro conditions that mimic many different environments. As sequencing of the Salmonella genome and microarray analysis have revolutionized genomics and transcriptomics of salmonellae over the last decade, so are new high-throughput sequencing technologies currently accelerating the pace of our studies and allowing us to approach complex problems that were not previously experimentally tractable.

  14. Domestication and plant genomes.

    Science.gov (United States)

    Tang, Haibao; Sezen, Uzay; Paterson, Andrew H

    2010-04-01

    The techniques of plant improvement have been evolving with the advancement of technology, progressing from crop domestication by Neolithic humans to scientific plant breeding, and now including DNA-based genotyping and genetic engineering. Archeological findings have shown that early human ancestors often unintentionally selected for and finally fixed a few major domestication traits over time. Recent advancement of molecular and genomic tools has enabled scientists to pinpoint changes to specific chromosomal regions and genetic loci that are responsible for dramatic morphological and other transitions that distinguish crops from their wild progenitors. Extensive studies in a multitude of additional crop species, facilitated by rapid progress in sequencing and resequencing(s) of crop genomes, will further our understanding of the genomic impact from both the unusual population history of cultivated plants and millennia of human selection.

  15. Brief Guide to Genomics: DNA, Genes and Genomes

    Science.gov (United States)

    ... de genómica A Brief Guide to Genomics DNA, Genes and Genomes Deoxyribonucleic acid (DNA) is the chemical ... needed to build the entire human body. A gene traditionally refers to the unit of DNA that ...

  16. Genomics in Cardiovascular Disease

    OpenAIRE

    Roberts, Robert; Marian, A.J.; Dandona, Sonny; Alexandre F R Stewart

    2013-01-01

    A paradigm shift towards biology occurred in the 1990’s subsequently catalyzed by the sequencing of the human genome in 2000. The cost of DNA sequencing has gone from millions to thousands of dollars with sequencing of one’s entire genome costing only $1,000. Rapid DNA sequencing is being embraced for single gene disorders, particularly for sporadic cases and those from small families. Transmission of lethal genes such as associated with Huntington’s disease can, through in-vitro fertilizatio...

  17. Precision genome editing

    DEFF Research Database (Denmark)

    Steentoft, Catharina; Bennett, Eric P; Schjoldager, Katrine Ter-Borch Gram;

    2014-01-01

    of glycobiology, primarily due to their low efficiencies, with resultant failure to impose substantial phenotypic consequences upon the final glycosylation products. Here, we review novel nuclease-based precision genome editing techniques enabling efficient and stable gene editing, including gene disruption...... by introducing single or double-stranded breaks at a defined genomic sequence. We here compare and contrast the different techniques and summarize their current applications, highlighting cases from the field of glycobiology as well as pointing to future opportunities. The emerging potential of precision gene...

  18. Mucin dynamics in intestinal bacterial infection.

    Directory of Open Access Journals (Sweden)

    Sara K Lindén

    Full Text Available BACKGROUND: Bacterial gastroenteritis causes morbidity and mortality in humans worldwide. Murine Citrobacter rodentium infection is a model for gastroenteritis caused by the human pathogens enteropathogenic Escherichia coli and enterohaemorrhagic E. coli. Mucin glycoproteins are the main component of the first barrier that bacteria encounter in the intestinal tract. METHODOLOGY/PRINCIPAL FINDINGS: Using Immunohistochemistry, we investigated intestinal expression of mucins (Alcian blue/PAS, Muc1, Muc2, Muc4, Muc5AC, Muc13 and Muc3/17 in healthy and C. rodentium infected mice. The majority of the C. rodentium infected mice developed systemic infection and colitis in the mid and distal colon by day 12. C. rodentium bound to the major secreted mucin, Muc2, in vitro, and high numbers of bacteria were found in secreted MUC2 in infected animals in vivo, indicating that mucins may limit bacterial access to the epithelial surface. In the small intestine, caecum and proximal colon, the mucin expression was similar in infected and non-infected animals. In the distal colonic epithelium, all secreted and cell surface mucins decreased with the exception of the Muc1 cell surface mucin which increased after infection (p<0.05. Similarly, during human infection Salmonella St Paul, Campylobacter jejuni and Clostridium difficile induced MUC1 in the colon. CONCLUSION: Major changes in both the cell-surface and secreted mucins occur in response to intestinal infection.

  19. Tick Genomics: The Ixodes genome project and beyond

    Science.gov (United States)

    Ticks and mites (subphylum Chelicerata; subclass Acari) are important pests of animals and plants worldwide. The Ixodes scapularis (black-legged tick) genome sequencing project marks the beginning of the genomics era for the field of acarology. This project is the first to sequence the genome of a...

  20. Exploring functional elements and genomic variation in the noncoding genome

    NARCIS (Netherlands)

    van Heesch, S.A.A.C.

    2014-01-01

    Gene expression regulation is a delicate process that depends on multiple aspects including genome structure and transcription factor binding to DNA elements. The majority of our genome consists of noncoding DNA, which was shown to be crucial in providing the correct context for genome function. Alt

  1. Genome Statute and Legislation Database

    Science.gov (United States)

    ... Database Welcome to the Genome Statute and Legislation Database The Genome Statute and Legislation Database is comprised ... the National Society of Genetic Counselors . Search the Database Search Tips You may select one or more ...

  2. Illuminating the Druggable Genome (IDG)

    Data.gov (United States)

    Federal Laboratory Consortium — Results from the Human Genome Project revealed that the human genome contains 20,000 to 25,000 genes. A gene contains (encodes) the information that each cell uses...

  3. RIKEN mouse genome encyclopedia.

    Science.gov (United States)

    Hayashizaki, Yoshihide

    2003-01-01

    We have been working to establish the comprehensive mouse full-length cDNA collection and sequence database to cover as many genes as we can, named Riken mouse genome encyclopedia. Recently we are constructing higher-level annotation (Functional ANnoTation Of Mouse cDNA; FANTOM) not only with homology search based annotation but also with expression data profile, mapping information and protein-protein database. More than 1,000,000 clones prepared from 163 tissues were end-sequenced to classify into 159,789 clusters and 60,770 representative clones were fully sequenced. As a conclusion, the 60,770 sequences contained 33,409 unique. The next generation of life science is clearly based on all of the genome information and resources. Based on our cDNA clones we developed the additional system to explore gene function. We developed cDNA microarray system to print all of these cDNA clones, protein-protein interaction screening system, protein-DNA interaction screening system and so on. The integrated database of all the information is very useful not only for analysis of gene transcriptional network and for the connection of gene to phenotype to facilitate positional candidate approach. In this talk, the prospect of the application of these genome resourced should be discussed. More information is available at the web page: http://genome.gsc.riken.go.jp/.

  4. Genetics, genomics and fertility

    Science.gov (United States)

    In order to enhance the sustainability of dairy businesses, new management tools are needed to increase the fertility of dairy cattle. Genomic selection has been successfully used by AI studs to screen potential sires and significantly decrease the generation interval of bulls. Buoyed by the success...

  5. The tomato genome

    Science.gov (United States)

    The tomato genome sequence was undertaken at a time when state-of-the-art sequencing methodologies were undergoing a transition to co-called next generation methodologies. The result was an international consortium undertaking a strategy merging both old and new approaches. Because biologists were...

  6. The UCSC Ebola Genome Portal

    OpenAIRE

    Haeussler, Maximilian; Karolchik, Donna; Clawson, Hiram; Raney, Brian J.; Rosenbloom, Kate R.; Fujita, Pauline A.; Hinrichs, Angie S.; Speir, Matthew L; Eisenhart, Chris; Zweig, Ann S.; Haussler, David; Kent, W. James

    2014-01-01

    Background: With the Ebola epidemic raging out of control in West Africa, there has been a flurry of research into the Ebola virus, resulting in the generation of much genomic data. Methods: In response to the clear need for tools that integrate multiple strands of research around molecular sequences, we have created the University of California Santa Cruz (UCSC) Ebola Genome Browser, an adaptation of our popular UCSC Genome Browser web tool, which can be used to view the Ebola virus genome s...

  7. Challenges in global genomics education

    Directory of Open Access Journals (Sweden)

    Ashwini de Abrew

    2014-12-01

    Full Text Available In spite of high expectations for the integration of genomics into medicine, it is not clear that health providers are competent to appropriately use new genomic approaches. The issue is further complicated by differences across the globe in terms of educational systems, access to genomic technologies, and priorities in health care. In this commentary we will review some of the major challenges in educating the health provider workforce about genomic medicine.

  8. Statistical Challenges in Functional Genomics

    OpenAIRE

    Sebastiani, Paola; Gussoni, Emanuela; Kohane, Isaac S.; Ramoni, Marco F

    2003-01-01

    On February 12, 2001 the Human Genome Project announced the completion of a draft physical map of the human genome---the genetic blueprint for a human being. Now the challenge is to annotate this map by understanding the functions of genes and their interplay with proteins and the environment to create complex, dynamic living systems. This is the goal of functional genomics. Recent technological advances enable biomedical investigators to observe the genome of entire orga...

  9. Genome stability in Caenorhabditis elegans

    NARCIS (Netherlands)

    Haaften, G.W. van

    2006-01-01

    Genome stability is closely linked to cancer. Most, if not all tumor cells show some form of genome instability, mutations can range from single point mutations to gross chromosomal rearrangements and aneuploidy. Genome instability is believed to be the driving force behind tumorigenesis. In order t

  10. Genome size of Mycoplasma genitalium.

    OpenAIRE

    Su, C J; Baseman, J B

    1990-01-01

    The genome size of Mycoplasma genitalium was determined by using restriction enzymes that infrequently cut its DNA. The calculated value of 577 to 590 kilobases is one-fourth smaller than the genome of Mycoplasma pneumoniae, which is considered among the smallest genomes of self-replicating organisms.

  11. Evolution of plant genome architecture.

    Science.gov (United States)

    Wendel, Jonathan F; Jackson, Scott A; Meyers, Blake C; Wing, Rod A

    2016-01-01

    We have witnessed an explosion in our understanding of the evolution and structure of plant genomes in recent years. Here, we highlight three important emergent realizations: (1) that the evolutionary history of all plant genomes contains multiple, cyclical episodes of whole-genome doubling that were followed by myriad fractionation processes; (2) that the vast majority of the variation in genome size reflects the dynamics of proliferation and loss of lineage-specific transposable elements; and (3) that various classes of small RNAs help shape genomic architecture and function. We illustrate ways in which understanding these organism-level and molecular genetic processes can be used for crop plant improvement. PMID:26926526

  12. Rice: The First Crop Genome.

    Science.gov (United States)

    Jackson, Scott A

    2016-12-01

    Rice was the first sequenced crop genome, paving the way for the sequencing of additional and more complicated crop genomes. The impact that the genome sequence made on rice genetics and breeding research was immediate, as evidence by citations and DNA marker use. The impact on other crop genomes was evident too, particularly for those within the grass family. As we celebrate 10 years since the completion of the rice genome sequence, we look forward to new empowering tool sets that will further revolutionize research in rice genetics and breeding and result in varieties that will continue to feed a growing population. PMID:27003180

  13. Microbial Genomics Research in China

    Institute of Scientific and Technical Information of China (English)

    ZHAOGuo-ping

    2004-01-01

    Microorganisms, including phage/virus, were initial targets and tools for developing DNA sequencing technology. Microbial genomic study was started as a model system for the Human Genome Project (HGP) and it did successfully supported the HGP, particularly with respect to BAC contig construction and large-scale shotgun sequencing and assembly. Microbial genomics study has become the fastest developed genomics discipline along with HGP, taking the advantage of the organisms' highly diversified physiology, extremely long history of evolution, close relationship with human/environment,as well as relatively small genome sizes and simple systems for functional analysis.

  14. Microbial Genomics Research in China

    Institute of Scientific and Technical Information of China (English)

    ZHAO Guo-ping

    2004-01-01

    @@ Microorganisms, including phage/virus, were initial targets and tools for developing DNA sequencing technology. Microbial genomic study was started as a model system for the Human Genome Project (HGP) and it did successfully supported the HGP, particularly with respect to BAC contig construction and large-scale shotgun sequencing and assembly. Microbial genomics study has become the fastest developed genomics discipline along with HGP, taking the advantage of the organisms' highly diversified physiology, extremely long history of evolution, close relationship with human/environment,as well as relatively small genome sizes and simple systems for functional analysis.

  15. Nongenetic functions of the genome.

    Science.gov (United States)

    Bustin, Michael; Misteli, Tom

    2016-05-01

    The primary function of the genome is to store, propagate, and express the genetic information that gives rise to a cell's architectural and functional machinery. However, the genome is also a major structural component of the cell. Besides its genetic roles, the genome affects cellular functions by nongenetic means through its physical and structural properties, particularly by exerting mechanical forces and by serving as a scaffold for binding of cellular components. Major cellular processes affected by nongenetic functions of the genome include establishment of nuclear structure, signal transduction, mechanoresponses, cell migration, and vision in nocturnal animals. We discuss the concept, mechanisms, and implications of nongenetic functions of the genome.

  16. Informational laws of genome structures

    Science.gov (United States)

    Bonnici, Vincenzo; Manca, Vincenzo

    2016-01-01

    In recent years, the analysis of genomes by means of strings of length k occurring in the genomes, called k-mers, has provided important insights into the basic mechanisms and design principles of genome structures. In the present study, we focus on the proper choice of the value of k for applying information theoretic concepts that express intrinsic aspects of genomes. The value k = lg2(n), where n is the genome length, is determined to be the best choice in the definition of some genomic informational indexes that are studied and computed for seventy genomes. These indexes, which are based on information entropies and on suitable comparisons with random genomes, suggest five informational laws, to which all of the considered genomes obey. Moreover, an informational genome complexity measure is proposed, which is a generalized logistic map that balances entropic and anti-entropic components of genomes and is related to their evolutionary dynamics. Finally, applications to computational synthetic biology are briefly outlined. PMID:27354155

  17. Evolution of small prokaryotic genomes

    Directory of Open Access Journals (Sweden)

    David José Martínez-Cano

    2015-01-01

    Full Text Available As revealed by genome sequencing, the biology of prokaryotes with reduced genomes is strikingly diverse. These include free-living prokaryotes with ~800 genes as well as endosymbiotic bacteria with as few as ~140 genes. Comparative genomics is revealing the evolutionary mechanisms that led to these small genomes. In the case of free-living prokaryotes, natural selection directly favored genome reduction, while in the case of endosymbiotic prokaryotes neutral processes played a more prominent role. However, new experimental data suggest that selective processes may be at operation as well for endosymbiotic prokaryotes at least during the first stages of genome reduction. Endosymbiotic prokaryotes have evolved diverse strategies for living with reduced gene sets inside a host-defined medium. These include utilization of host-encoded functions (some of them coded by genes acquired by gene transfer from the endosymbiont and/or other bacteria; metabolic complementation between co-symbionts; and forming consortiums with other bacteria within the host. Recent genome sequencing projects of intracellular mutualistic bacteria showed that previously believed universal evolutionary trends like reduced G+C content and conservation of genome synteny are not always present in highly reduced genomes. Finally, the simplified molecular machinery of some of these organisms with small genomes may be used to aid in the design of artificial minimal cells. Here we review recent genomic discoveries of the biology of prokaryotes endowed with small gene sets and discuss the evolutionary mechanisms that have been proposed to explain their peculiar nature.

  18. Informational laws of genome structures

    Science.gov (United States)

    Bonnici, Vincenzo; Manca, Vincenzo

    2016-06-01

    In recent years, the analysis of genomes by means of strings of length k occurring in the genomes, called k-mers, has provided important insights into the basic mechanisms and design principles of genome structures. In the present study, we focus on the proper choice of the value of k for applying information theoretic concepts that express intrinsic aspects of genomes. The value k = lg2(n), where n is the genome length, is determined to be the best choice in the definition of some genomic informational indexes that are studied and computed for seventy genomes. These indexes, which are based on information entropies and on suitable comparisons with random genomes, suggest five informational laws, to which all of the considered genomes obey. Moreover, an informational genome complexity measure is proposed, which is a generalized logistic map that balances entropic and anti-entropic components of genomes and is related to their evolutionary dynamics. Finally, applications to computational synthetic biology are briefly outlined.

  19. 132株弗劳地枸橼酸杆菌致重症患者医院感染的原因与耐药性分析%Analysis of the etiology and drug resistance of hospital infection in critically ill patients caused by 132 Citrobacter freundii

    Institute of Scientific and Technical Information of China (English)

    温国辉

    2015-01-01

    Objective To analysis of the causes and drug resistance characteristics in ICU patients with Citrobacter freundii hos‐pital infections ,for the future of clinical treatment and prevention of Citrobacter freundii infection provides the basis .Methods Col‐lected our hospitals from December 2011 to November 2014 clinical samples of ICU patients ,conventional isolation and culture of bacteria ,K‐B disk diffusion susceptibility test ,using Whonet5 .6 software analysis processing tentative data .Results Isolated from Critically ill patients Citrobacter freundii lower respiratory tract ,accounted for 64 .4% ;ESBLs producing high ,accounted for 35 .6% ;susceptibility testing showed the bacteria to imipenem ,meropenem ,nitrofurantoin ,kanamycin ,amikacin ,cefoperazone/sul‐bactam and piperacillin/tazobactam were more sensitive ,drug resistance rates were 3 .8% ,4 .5% ,8 .3% ,9 .1% ,17 .4% ,18 .1% and 22 .7% ,the rest of antimicrobial drug resistance rates more than 25 .0% .Conclusion Citrobacter freundii caused critically ill pa‐tients hospital infection have become increasingly serious ,lower respiratory tract was the main site of infection ,the bacteria used in the clinic for cephalosporin ,quinolones ,aminoglycosides and a variety of internal β‐lactam antibiotics were highly resistant ,clinicians should strengthen monitoring of drug resistance ,to reduce the resistant strains produced and spread within the hospital .%目的:分析该院重症监护病房患者弗劳地枸橼酸杆菌医院感染的原因和耐药特点,为今后的临床治疗和预防弗劳地枸橼酸杆菌感染提供依据。方法收集该院2011年12月至2014年11月重症监护病房患者的临床标本,常规分离培养细菌,K‐B纸片法进行药敏试验,利用WHONET 5.6软件分析处理实验数据。结果从重症患者分离的弗劳地枸橼酸杆菌以下呼吸道为主,占64.4%;产ESBLs高,达35.6%;药敏试验表明该菌对亚胺培南、

  20. Genome size analyses of Pucciniales reveal the largest fungal genomes

    Directory of Open Access Journals (Sweden)

    Silvia eTavares

    2014-08-01

    Full Text Available Rust fungi (Basidiomycota, Pucciniales are biotrophic plant pathogens which exhibit diverse complexities in their life cycles and host ranges. The completion of genome sequencing of a few rust fungi has revealed the occurrence of large genomes. Sequencing efforts for other rust fungi have been hampered by uncertainty concerning their genome sizes. Flow cytometry was recently applied to estimate the genome size of a few rust fungi, and confirmed the occurrence of large genomes in this order (averaging 151.5 Mbp, while the average for Basidiomycota was 49.9 Mbp and was 37.7 Mbp for all fungi. In this work, we have used an innovative and simple approach to simultaneously isolate nuclei from the rust and its host plant in order to estimate the genome size of 30 rust species by flow cytometry. Genome sizes varied over 10-fold, from 70 to 893 Mbp, with an average genome size value of 380.2 Mbp. Compared to the genome sizes of over 1,800 fungi, Gymnosporangium confusum possesses the largest fungal genome ever reported (893.2 Mbp. Moreover, even the smallest rust genome determined in this study is larger than the vast majority of fungal genomes (94 %. The average genome size of the Pucciniales is now of 305.5 Mbp, while the average Basidiomycota genome size has shifted to 70.4 Mbp and the average for all fungi reached 44.2 Mbp. Despite the fact that no correlation could be drawn between the genome sizes, the phylogenomics or the life cycle of rust fungi, it is interesting to note that rusts with Fabaceae hosts present genomes clearly larger than those with Poaceae hosts. Although this study comprises only a small fraction of the more than 7,000 rust species described, it seems already evident that the Pucciniales represent a group where genome size expansion could be a common characteristic. This is in sharp contrast to sister taxa, placing this order in a relevant position in fungal genomics research.

  1. Optimization of fermentation conditions for violacein production by recombinant Citrobacter freundii%重组柠檬酸杆菌合成紫色杆菌素的工艺条件优化

    Institute of Scientific and Technical Information of China (English)

    张瑞萍; 蒋培霞; 李春; 邢新会

    2010-01-01

    以L-色氨酸为前体物,对弗氏柠檬酸杆菌(Citrobacter freundii)基因工程菌株生产紫色杆菌素的工艺条件进行了优化.通过单因素实验研究了培养基种类、培养温度、碳源、溶氧、种子液的状态、接种量、诱导时机、诱导剂的浓度及初始pH对细胞生长和紫色杆菌素产量的影响,通过正交实验研究了这些因素中可能存在交互作用的4个因素(种子液OD660、接种量、诱导时机、诱导剂浓度)的影响主次,确定了这些因素、水平的最佳搭配方案.结果表明,重组柠檬酸杆菌合成紫色杆菌素的最优培养条件为:种子液培养至OD660=3.6时,以3 %的接种量接种于以甘油为碳源、初始pH为6.5的磷酸盐发酵培养基E2(25 μg·ml-1卡那霉素),先在37℃、200 r·min-1下培养至OD660=1.4,然后加入0.5 μl·ml-1的诱导剂正辛烷,同时转入20℃,在150 r·min-1下诱导培养31 h.在此最优条件下,紫色杆菌素粗提物(紫色杆菌素及脱氧紫色杆菌素的混合物)产量可达1.809 g·L-1,比优化前(0.514 g·L-1)提高了252%,是目前国际上其他研究小组报道的最高摇瓶产量(0.43 g·L-1)的4.2倍.质粒稳定性实验结果表明重组柠檬酸杆菌在抗生素选择压力条件下具有良好的遗传稳定性.

  2. Genomic dairy cattle breeding

    DEFF Research Database (Denmark)

    Mark, Thomas; Sandøe, Peter

    2010-01-01

    it less accountable to the concern of private farmers for the welfare of their animals. It is argued that there is a need to mobilise a wide range of stakeholders to monitor developments and maintain pressure on breeding companies so that they are aware of the need to take precautionary measures to avoid...... these new genomic tools are especially useful for traits relating to animal welfare that are difficult to improve using traditional breeding tools, they may also facilitate breeding schemes with reduced generation intervals carrying a higher risk of unwanted side-effects on animal welfare. In this paper...... negative effects on animal welfare and to invest in breeding for increased animal welfare. Researchers are encouraged to further investigate the long-term effects of various breeding schemes that rely on genomic breeding values....

  3. eGenomics: Cataloguing Our Complete Genome Collection III

    Directory of Open Access Journals (Sweden)

    Dawn Field

    2007-01-01

    Full Text Available This meeting report summarizes the proceedings of the “eGenomics: Cataloguing our Complete Genome Collection III” workshop held September 11–13, 2006, at the National Institute for Environmental eScience (NIEeS, Cambridge, United Kingdom. This 3rd workshop of the Genomic Standards Consortium was divided into two parts. The first half of the three-day workshop was dedicated to reviewing the genomic diversity of our current and future genome and metagenome collection, and exploring linkages to a series of existing projects through formal presentations. The second half was dedicated to strategic discussions. Outcomes of the workshop include a revised “Minimum Information about a Genome Sequence” (MIGS specification (v1.1, consensus on a variety of features to be added to the Genome Catalogue (GCat, agreement by several researchers to adopt MIGS for imminent genome publications, and an agreement by the EBI and NCBI to input their genome collections into GCat for the purpose of quantifying the amount of optional data already available (e.g., for geographic location coordinates and working towards a single, global list of all public genomes and metagenomes.

  4. Genomic landscape of liposarcoma.

    Science.gov (United States)

    Kanojia, Deepika; Nagata, Yasunobu; Garg, Manoj; Lee, Dhong Hyun; Sato, Aiko; Yoshida, Kenichi; Sato, Yusuke; Sanada, Masashi; Mayakonda, Anand; Bartenhagen, Christoph; Klein, Hans-Ulrich; Doan, Ngan B; Said, Jonathan W; Mohith, S; Gunasekar, Swetha; Shiraishi, Yuichi; Chiba, Kenichi; Tanaka, Hiroko; Miyano, Satoru; Myklebost, Ola; Yang, Henry; Dugas, Martin; Meza-Zepeda, Leonardo A; Silberman, Allan W; Forscher, Charles; Tyner, Jeffrey W; Ogawa, Seishi; Koeffler, H Phillip

    2015-12-15

    Liposarcoma (LPS) is the most common type of soft tissue sarcoma accounting for 20% of all adult sarcomas. Due to absence of clinically effective treatment options in inoperable situations and resistance to chemotherapeutics, a critical need exists to identify novel therapeutic targets. We analyzed LPS genomic landscape using SNP arrays, whole exome sequencing and targeted exome sequencing to uncover the genomic information for development of specific anti-cancer targets. SNP array analysis indicated known amplified genes (MDM2, CDK4, HMGA2) and important novel genes (UAP1, MIR557, LAMA4, CPM, IGF2, ERBB3, IGF1R). Carboxypeptidase M (CPM), recurrently amplified gene in well-differentiated/de-differentiated LPS was noted as a putative oncogene involved in the EGFR pathway. Notable deletions were found at chromosome 1p (RUNX3, ARID1A), chromosome 11q (ATM, CHEK1) and chromosome 13q14.2 (MIR15A, MIR16-1). Significantly and recurrently mutated genes (false discovery rate < 0.05) included PLEC (27%), MXRA5 (21%), FAT3 (24%), NF1 (20%), MDC1 (10%), TP53 (7%) and CHEK2 (6%). Further, in vitro and in vivo functional studies provided evidence for the tumor suppressor role for Neurofibromin 1 (NF1) gene in different subtypes of LPS. Pathway analysis of recurrent mutations demonstrated signaling through MAPK, JAK-STAT, Wnt, ErbB, axon guidance, apoptosis, DNA damage repair and cell cycle pathways were involved in liposarcomagenesis. Interestingly, we also found mutational and copy number heterogeneity within a primary LPS tumor signifying the importance of multi-region sequencing for cancer-genome guided therapy. In summary, these findings provide insight into the genomic complexity of LPS and highlight potential druggable pathways for targeted therapeutic approach.

  5. Genomics Research Group Session

    OpenAIRE

    Baldwin, D.; Chittur, S.V.; Raghavachari, N.; N Jafari; Aquino, C.; Perera, A; Reyero, N.G.

    2014-01-01

    The Genomics Research Group (GRG) presentation is intended to describe the current activities of the group in applying the latest tools and technologies for transcriptome analysis to determine the advantages and disadvantages of each of the platforms. We will present three ongoing projects. In the first project, we specifically evaluated microarrays, QPCR and Next Generation Sequencing (NGS) platforms for examining the sensitivity and specificity of microRNA detection using synthetic miRNA st...

  6. The genomics of adaptation

    OpenAIRE

    Radwan, Jacek; Babik, Wiesław

    2012-01-01

    The amount and nature of genetic variation available to natural selection affect the rate, course and outcome of evolution. Consequently, the study of the genetic basis of adaptive evolutionary change has occupied biologists for decades, but progress has been hampered by the lack of resolution and the absence of a genome-level perspective. Technological advances in recent years should now allow us to answer many long-standing questions about the nature of adaptation. The data gathered so far ...

  7. Genomic Feature Models

    DEFF Research Database (Denmark)

    Sørensen, Peter; Edwards, Stefan McKinnon; Rohde, Palle Duun

    Whole-genome sequences and multiple trait phenotypes from large numbers of individuals will soon be available in many populations. Well established statistical modeling approaches enable the genetic analyses of complex trait phenotypes while accounting for a variety of additive and non-additive g...... regions and gene ontologies) that provide better model fit and increase predictive ability of the statistical model for this trait....

  8. Human Social Genomics

    OpenAIRE

    Cole, Steven W.

    2014-01-01

    A growing literature in human social genomics has begun to analyze how everyday life circumstances influence human gene expression. Social-environmental conditions such as urbanity, low socioeconomic status, social isolation, social threat, and low or unstable social status have been found to associate with differential expression of hundreds of gene transcripts in leukocytes and diseased tissues such as metastatic cancers. In leukocytes, diverse types of social adversity evoke a common conse...

  9. Genomic Prediction from Whole Genome Sequence in Livestock: The 1000 Bull Genomes Project

    DEFF Research Database (Denmark)

    Hayes, Benjamin J; MacLeod, Iona M; Daetwyler, Hans D;

    Advantages of using whole genome sequence data to predict genomic estimated breeding values (GEBV) include better persistence of accuracy of GEBV across generations and more accurate GEBV across breeds. The 1000 Bull Genomes Project provides a database of whole genome sequenced key ancestor bulls......, for imputing sequence variant genotypes into reference sets for genomic prediction. Run 3.0 included 429 sequences, with 31.8 million variants detected. BayesRC, a new method for genomic prediction, addresses some challenges associated with using the sequence data, and takes advantage of biological...... information. In a dairy data set, predictions using BayesRC and imputed sequence data from 1000 Bull Genomes were 2% more accurate than with 800k data. We could demonstrate the method identified causal mutations in some cases. Further improvements will come from more accurate imputation of sequence variant...

  10. Genome update: the 1000th genome - a cautionary tale

    DEFF Research Database (Denmark)

    Lagesen, Karin; Ussery, David; Wassenaar, Gertrude Maria

    2010-01-01

    There are now more than 1000 sequenced prokaryotic genomes deposited in public databases and available for analysis. Currently, although the sequence databases GenBank, DNA Database of Japan and EMBL are synchronized continually, there are slight differences in content at the genomes level...... for a variety of logistical reasons, including differences in format and loading errors, such as those caused by file transfer protocol interruptions. This means that the 1000th genome will be different in the various databases. Some of the data on the highly accessed web pages are inaccurate, leading to false...... conclusions for example about the largest bacterial genome sequenced. Biological diversity is far greater than many have thought. For example, analysis of multiple Escherichia coli genomes has led to an estimate of around 45 000 gene families more genes than are recognized in the human genome. Moreover...

  11. Genome-wide association and genomic selection in animal breeding.

    Science.gov (United States)

    Hayes, Ben; Goddard, Mike

    2010-11-01

    Results from genome-wide association studies in livestock, and humans, has lead to the conclusion that the effect of individual quantitative trait loci (QTL) on complex traits, such as yield, are likely to be small; therefore, a large number of QTL are necessary to explain genetic variation in these traits. Given this genetic architecture, gains from marker-assisted selection (MAS) programs using only a small number of DNA markers to trace a limited number of QTL is likely to be small. This has lead to the development of alternative technology for using the available dense single nucleotide polymorphism (SNP) information, called genomic selection. Genomic selection uses a genome-wide panel of dense markers so that all QTL are likely to be in linkage disequilibrium with at least one SNP. The genomic breeding values are predicted to be the sum of the effect of these SNPs across the entire genome. In dairy cattle breeding, the accuracy of genomic estimated breeding values (GEBV) that can be achieved and the fact that these are available early in life have lead to rapid adoption of the technology. Here, we discuss the design of experiments necessary to achieve accurate prediction of GEBV in future generations in terms of the number of markers necessary and the size of the reference population where marker effects are estimated. We also present a simple method for implementing genomic selection using a genomic relationship matrix. Future challenges discussed include using whole genome sequence data to improve the accuracy of genomic selection and management of inbreeding through genomic relationships.

  12. Genome Update: alignment of bacterial chromosomes

    DEFF Research Database (Denmark)

    Ussery, David; Jensen, Mette; Poulsen, Tine Rugh;

    2004-01-01

    There are four new microbial genomes listed in this month's Genome Update, three belonging to Gram-positive bacteria and one belonging to an archaeon that lives at pH 0; all of these genomes are listed in Table 1⇓. The method of genome comparison this month is that of genome alignment and......, as an example, an alignment of seven Staphylococcus aureus genomes and one Staphylococcus epidermidis genome is presented....

  13. Genomic Data Commons and Genomic Cloud Pilots - Google Hangout

    Science.gov (United States)

    Join us for a live, moderated discussion about two NCI efforts to expand access to cancer genomics data: the Genomic Data Commons and Genomic Cloud Pilots. NCI subject matters experts will include Louis M. Staudt, M.D., Ph.D., Director Center for Cancer Genomics, Warren Kibbe, Ph.D., Director, NCI Center for Biomedical Informatics and Information Technology, and moderated by Anthony Kerlavage, Ph.D., Chief, Cancer Informatics Branch, Center for Biomedical Informatics and Information Technology. We welcome your questions before and during the Hangout on Twitter using the hashtag #AskNCI.

  14. The Saccharomyces Genome Database: Exploring Genome Features and Their Annotations.

    Science.gov (United States)

    Cherry, J Michael

    2015-12-01

    Genomic-scale assays result in data that provide information over the entire genome. Such base pair resolution data cannot be summarized easily except via a graphical viewer. A genome browser is a tool that displays genomic data and experimental results as horizontal tracks. Genome browsers allow searches for a chromosomal coordinate or a feature, such as a gene name, but they do not allow searches by function or upstream binding site. Entry into a genome browser requires that you identify the gene name or chromosomal coordinates for a region of interest. A track provides a representation for genomic results and is displayed as a row of data shown as line segments to indicate regions of the chromosome with a feature. Another type of track presents a graph or wiggle plot that indicates the processed signal intensity computed for a particular experiment or set of experiments. Wiggle plots are typical for genomic assays such as the various next-generation sequencing methods (e.g., chromatin immunoprecipitation [ChIP]-seq or RNA-seq), where it represents a peak of DNA binding, histone modification, or the mapping of an RNA sequence. Here we explore the browser that has been built into the Saccharomyces Genome Database (SGD). PMID:26631126

  15. Domestication genomics: evidence from animals.

    Science.gov (United States)

    Wang, Guo-Dong; Xie, Hai-Bing; Peng, Min-Sheng; Irwin, David; Zhang, Ya-Ping

    2014-02-01

    Animal domestication has far-reaching significance for human society. The sequenced genomes of domesticated animals provide critical resources for understanding the genetic basis of domestication. Various genomic analyses have shed a new light on the mechanism of artificial selection and have allowed the mapping of genes involved in important domestication traits. Here, we summarize the published genomes of domesticated animals that have been generated over the past decade, as well as their origins, from a phylogenomic point of view. This review provides a general description of the genomic features encountered under a two-stage domestication process. We also introduce recent findings for domestication traits based on results from genome-wide association studies and selective-sweep scans for artificially selected genomic regions. Particular attention is paid to issues relating to the costs of domestication and the convergent evolution of genes between domesticated animals and humans.

  16. Genome engineering in Vibrio cholerae

    DEFF Research Database (Denmark)

    Val, Marie-Eve; Skovgaard, Ole; Ducos-Galand, Magaly;

    2012-01-01

    Although bacteria with multipartite genomes are prevalent, our knowledge of the mechanisms maintaining their genome is very limited, and much remains to be learned about the structural and functional interrelationships of multiple chromosomes. Owing to its bi-chromosomal genome architecture and its...... importance in public health, Vibrio cholerae, the causative agent of cholera, has become a preferred model to study bacteria with multipartite genomes. However, most in vivo studies in V. cholerae have been hampered by its genome architecture, as it is difficult to give phenotypes to a specific chromosome....... This difficulty was surmounted using a unique and powerful strategy based on massive rearrangement of prokaryotic genomes. We developed a site-specific recombination-based engineering tool, which allows targeted, oriented, and reciprocal DNA exchanges. Using this genetic tool, we obtained a panel of V. cholerae...

  17. Big Data: Astronomical or Genomical?

    Directory of Open Access Journals (Sweden)

    Zachary D Stephens

    2015-07-01

    Full Text Available Genomics is a Big Data science and is going to get much bigger, very soon, but it is not known whether the needs of genomics will exceed other Big Data domains. Projecting to the year 2025, we compared genomics with three other major generators of Big Data: astronomy, YouTube, and Twitter. Our estimates show that genomics is a "four-headed beast"--it is either on par with or the most demanding of the domains analyzed here in terms of data acquisition, storage, distribution, and analysis. We discuss aspects of new technologies that will need to be developed to rise up and meet the computational challenges that genomics poses for the near future. Now is the time for concerted, community-wide planning for the "genomical" challenges of the next decade.

  18. Programs | Office of Cancer Genomics

    Science.gov (United States)

    OCG facilitates cancer genomics research through a series of highly-focused programs. These programs generate and disseminate genomic data for use by the cancer research community. OCG programs also promote advances in technology-based infrastructure and create valuable experimental reagents and tools. OCG programs encourage collaboration by interconnecting with other genomics and cancer projects in order to accelerate translation of findings into the clinic. Below are OCG’s current, completed, and initiated programs:

  19. Genome mapping of the horse

    OpenAIRE

    Lindgren, Gabriella

    2001-01-01

    Our ability to map and sequence whole genomes is one of the most important developments in biological science. It will provide us with an unprecedented insight into the genetic background of phenotypic traits, such as disease resistance, reproduction and growth and also makes it feasible to study the processes of genome evolution. The main focus of this thesis has been to develop a linkage map of the horse (Equus caballus) genome. A secondary aim was to expand the number of physically mapped ...

  20. Bacterial genome reengineering.

    Science.gov (United States)

    Zhou, Jindan; Rudd, Kenneth E

    2011-01-01

    The web application PrimerPair at ecogene.org generates large sets of paired DNA sequences surrounding- all protein and RNA genes of Escherichia coli K-12. Many DNA fragments, which these primers amplify, can be used to implement a genome reengineering strategy using complementary in vitro cloning and in vivo recombineering. The integration of a primer design tool with a model organism database increases the level of quality control. Computer-assisted design of gene primer pairs relies upon having highly accurate genomic DNA sequence information that exactly matches the DNA of the cells being used in the laboratory to ensure predictable DNA hybridizations. It is equally crucial to have confidence that the predicted start codons define the locations of genes accurately. Annotations in the EcoGene database are queried by PrimerPair to eliminate pseudogenes, IS elements, and other problematic genes before the design process starts. These projects progressively familiarize users with the EcoGene content, scope, and application interfaces that are useful for genome reengineering projects. The first protocol leads to the design of a pair of primer sequences that were used to clone and express a single gene. The N-terminal protein sequence was experimentally verified and the protein was detected in the periplasm. This is followed by instructions to design PCR primer pairs for cloning gene fragments encoding 50 periplasmic proteins without their signal peptides. The design process begins with the user simply designating one pair of forward and reverse primer endpoint positions relative to all start and stop codon positions. The gene name, genomic coordinates, and primer DNA sequences are reported to the user. When making chromosomal deletions, the integrity of the provisional primer design is checked to see whether it will generate any unwanted double deletions with adjacent genes. The bad designs are recalculated and replacement primers are provided alongside the

  1. Organizational heterogeneity of vertebrate genomes.

    Directory of Open Access Journals (Sweden)

    Svetlana Frenkel

    Full Text Available Genomes of higher eukaryotes are mosaics of segments with various structural, functional, and evolutionary properties. The availability of whole-genome sequences allows the investigation of their structure as "texts" using different statistical and computational methods. One such method, referred to as Compositional Spectra (CS analysis, is based on scoring the occurrences of fixed-length oligonucleotides (k-mers in the target DNA sequence. CS analysis allows generating species- or region-specific characteristics of the genome, regardless of their length and the presence of coding DNA. In this study, we consider the heterogeneity of vertebrate genomes as a joint effect of regional variation in sequence organization superimposed on the differences in nucleotide composition. We estimated compositional and organizational heterogeneity of genome and chromosome sequences separately and found that both heterogeneity types vary widely among genomes as well as among chromosomes in all investigated taxonomic groups. The high correspondence of heterogeneity scores obtained on three genome fractions, coding, repetitive, and the remaining part of the noncoding DNA (the genome dark matter--GDM allows the assumption that CS-heterogeneity may have functional relevance to genome regulation. Of special interest for such interpretation is the fact that natural GDM sequences display the highest deviation from the corresponding reshuffled sequences.

  2. Genome engineering in Vibrio cholerae

    DEFF Research Database (Denmark)

    Val, Marie-Eve; Skovgaard, Ole; Ducos-Galand, Magaly;

    2012-01-01

    Although bacteria with multipartite genomes are prevalent, our knowledge of the mechanisms maintaining their genome is very limited, and much remains to be learned about the structural and functional interrelationships of multiple chromosomes. Owing to its bi-chromosomal genome architecture and its....... This difficulty was surmounted using a unique and powerful strategy based on massive rearrangement of prokaryotic genomes. We developed a site-specific recombination-based engineering tool, which allows targeted, oriented, and reciprocal DNA exchanges. Using this genetic tool, we obtained a panel of V. cholerae...

  3. Preemptive public policy for genomics.

    Science.gov (United States)

    Carlson, Rick J

    2008-02-01

    To many, genomics is merely exploitable technology for the leviathan of biotechnology. This is both shallow and short sighted. Genomics is applied knowledge based on profound and evolving science about how living things develop, how healthy or sick we are, and what our future will be like. In health care, genomics technologies are disruptive yet potentially cost-effective because they enable primary prevention, the antidote to runaway costs and declining productivity. The challenges to integration are great, however, and many bioethical and social-policy implications are alarming. Because it is poorly understood today, we must debate genomics vigorously if we are to act wisely. Public policy must lead.

  4. Comparative genomics of Lactobacillus and other LAB

    DEFF Research Database (Denmark)

    Wassenaar, Trudy M.; Lukjancenko, Oksana

    2014-01-01

    The genomes of 66 LABs, belonging to five different genera, were compared for genome size and gene content. The analyzed genomes included 37 Lactobacillus genomes of 17 species, six Lactococcus lactis genomes, four Leuconostoc genomes of three species, six Streptococcus genomes of two species...... that of the others, with the two Streptococcus species having the shortest genomes. The widest distribution in genome content was observed for Lactobacillus. The number of tRNA and rRNA gene copies varied considerably, with exceptional high numbers observed for Lb. delbrueckii, while these numbers were relatively...

  5. Comparative genomics reveals insights into avian genome evolution and adaptation

    DEFF Research Database (Denmark)

    Zhang, Guojie; Li, Cai; Li, Qiye;

    2014-01-01

    Birds are the most species-rich class of tetrapod vertebrates and have wide relevance across many research fields. We explored bird macroevolution using full genomes from 48 avian species representing all major extant clades. The avian genome is principally characterized by its constrained size, ...

  6. Insights into structural variations and genome rearrangements in prokaryotic genomes.

    Science.gov (United States)

    Periwal, Vinita; Scaria, Vinod

    2015-01-01

    Structural variations (SVs) are genomic rearrangements that affect fairly large fragments of DNA. Most of the SVs such as inversions, deletions and translocations have been largely studied in context of genetic diseases in eukaryotes. However, recent studies demonstrate that genome rearrangements can also have profound impact on prokaryotic genomes, leading to altered cell phenotype. In contrast to single-nucleotide variations, SVs provide a much deeper insight into organization of bacterial genomes at a much better resolution. SVs can confer change in gene copy number, creation of new genes, altered gene expression and many other functional consequences. High-throughput technologies have now made it possible to explore SVs at a much refined resolution in bacterial genomes. Through this review, we aim to highlight the importance of the less explored field of SVs in prokaryotic genomes and their impact. We also discuss its potential applicability in the emerging fields of synthetic biology and genome engineering where targeted SVs could serve to create sophisticated and accurate genome editing.

  7. Genomic and darwinian medicine

    Directory of Open Access Journals (Sweden)

    Salzano, Francisco M

    2009-01-01

    Full Text Available Genomic and darwinian medicine deal with the application of hereditary and evolutionary principles for the understanding of health and disease. The progress in molecular and bioinformatic knowledge is making possible through a holistic approach to biological phenomena and one aspect of it, host-pathogen coevolution, is discussed with examples of research performed by our group. The search for the etiology of genetic diseases can focus on simple traits with mendelian inheritance or in more complex multifactorial characteristics, as well as in nuclear or mitochondrial DNA genes. Also important is the investigation of genetically conditioned variation in response to drugs (pharmacogenomics and unorthodox environmental effects (epigenetics. Every day the genome of a given cell receives one million lesions which should be repaired. Defects in repair mechanisms can lead to diseases, one important category of them being neurological disorders. The association between intronic inversions which lead to severe hemophilia A and the prevalence of Factor VIII inhibitors in these patients was also considered using information obtained by the Porto Alegre group and those of colleagues living in other cities. The fi nal message emphasizes the need for an evolutionary approach to fully understand pathologic processes and their management.

  8. Genomics of human longevity.

    Science.gov (United States)

    Slagboom, P E; Beekman, M; Passtoors, W M; Deelen, J; Vaarhorst, A A M; Boer, J M; van den Akker, E B; van Heemst, D; de Craen, A J M; Maier, A B; Rozing, M; Mooijaart, S P; Heijmans, B T; Westendorp, R G J

    2011-01-12

    In animal models, single-gene mutations in genes involved in insulin/IGF and target of rapamycin signalling pathways extend lifespan to a considerable extent. The genetic, genomic and epigenetic influences on human longevity are expected to be much more complex. Strikingly however, beneficial metabolic and cellular features of long-lived families resemble those in animals for whom the lifespan is extended by applying genetic manipulation and, especially, dietary restriction. Candidate gene studies in humans support the notion that human orthologues from longevity genes identified in lower species do contribute to longevity but that the influence of the genetic variants involved is small. Here we discuss how an integration of novel study designs, labour-intensive biobanking, deep phenotyping and genomic research may provide insights into the mechanisms that drive human longevity and healthy ageing, beyond the associations usually provided by molecular and genetic epidemiology. Although prospective studies of humans from the cradle to the grave have never been performed, it is feasible to extract life histories from different cohorts jointly covering the molecular changes that occur with age from early development all the way up to the age at death. By the integration of research in different study cohorts, and with research in animal models, biological research into human longevity is thus making considerable progress.

  9. Parsing of genomic graffiti

    Energy Technology Data Exchange (ETDEWEB)

    Tibbetts, C.; Golden, J. III; Torgersen, D. [Vanderbilt Univ. School of Engineering, Nashville, TN (United States)

    1996-12-31

    A focal point of modern biology is investigation of wide varieties of phenomena at the level of molecular genetics. The nucleotide sequences of deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) define the ultimate resolution of this reductionist approach to understand the determinants of heritable traits. The structure and function of genes, their composite genomic organization, and their regulated expression have been studied in systems representing every class of organism. Many human diseases or pathogenic syndromes can be directly attributed to inherited defects in either the regulated expression, or the quality of the products of specific genes. Genetic determinants of susceptibility to infectious agents or environmental hazards are amply documented. Mapping and sequencing of the DNA molecules encoding human genes have provided powerful technology for pharmaceutical bioengineering and forensic investigations. From an alternative perspective, we may anticipate that voluminous archives of singular DNA sequences alone will not suffice to define and understand the functional determinants of genome organization, allelic diversity and evolutionary plasticity of living organisms. New insights will accumulate pertaining to human evolutionary origins and relationships of human biology to models based on other mammals. Investigators of population genetics and epidemiology now exploit the technology of molecular genetics to more powerfully probe variation within the human gene pool at the level of DNA sequences. 40 refs., 7 figs., 2 tabs.

  10. A Taste of Algal Genomes from the Joint Genome Institute

    Energy Technology Data Exchange (ETDEWEB)

    Kuo, Alan; Grigoriev, Igor

    2012-06-17

    Algae play profound roles in aquatic food chains and the carbon cycle, can impose health and economic costs through toxic blooms, provide models for the study of symbiosis, photosynthesis, and eukaryotic evolution, and are candidate sources for bio-fuels; all of these research areas are part of the mission of DOE's Joint Genome Institute (JGI). To date JGI has sequenced, assembled, annotated, and released to the public the genomes of 18 species and strains of algae, sampling almost all of the major clades of photosynthetic eukaryotes. With more algal genomes currently undergoing analysis, JGI continues its commitment to driving forward basic and applied algal science. Among these ongoing projects are the pan-genome of the dominant coccolithophore Emiliania huxleyi, the interrelationships between the 4 genomes in the nucleomorph-containing Bigelowiella natans and Guillardia theta, and the search for symbiosis genes of lichens.

  11. Parasite Genome Projects and the Trypanosoma cruzi Genome Initiative

    Directory of Open Access Journals (Sweden)

    Wim Degrave

    1997-11-01

    Full Text Available Since the start of the human genome project, a great number of genome projects on other "model" organism have been initiated, some of them already completed. Several initiatives have also been started on parasite genomes, mainly through support from WHO/TDR, involving North-South and South-South collaborations, and great hopes are vested in that these initiatives will lead to new tools for disease control and prevention, as well as to the establishment of genomic research technology in developing countries. The Trypanosoma cruzi genome project, using the clone CL-Brener as starting point, has made considerable progress through the concerted action of more than 20 laboratories, most of them in the South. A brief overview of the current state of the project is given

  12. The Perennial Ryegrass GenomeZipper – Targeted Use of Genome Resources for Comparative Grass Genomics

    DEFF Research Database (Denmark)

    Pfeiffer, Matthias; Martis, Mihaela; Asp, Torben;

    2013-01-01

    (Lolium perenne) genome on the basis of conserved synteny to barley (Hordeum vulgare) and the model grass genome Brachypodium (Brachypodium distachyon) as well as rice (Oryza sativa) and sorghum (Sorghum bicolor). A transcriptome-based genetic linkage map of perennial ryegrass served as a scaffold to...... assignment of 3,315 out of 8,876 previously unmapped genes to the respective chromosomes. In total, the GenomeZipper incorporates 4,035 conserved grass gene loci, which were used for the first genome-wide sequence divergence analysis between perennial ryegrass, barley, Brachypodium, rice, and sorghum. The...

  13. OryzaGenome: Genome Diversity Database of Wild Oryza Species.

    Science.gov (United States)

    Ohyanagi, Hajime; Ebata, Toshinobu; Huang, Xuehui; Gong, Hao; Fujita, Masahiro; Mochizuki, Takako; Toyoda, Atsushi; Fujiyama, Asao; Kaminuma, Eli; Nakamura, Yasukazu; Feng, Qi; Wang, Zi-Xuan; Han, Bin; Kurata, Nori

    2016-01-01

    The species in the genus Oryza, encompassing nine genome types and 23 species, are a rich genetic resource and may have applications in deeper genomic analyses aiming to understand the evolution of plant genomes. With the advancement of next-generation sequencing (NGS) technology, a flood of Oryza species reference genomes and genomic variation information has become available in recent years. This genomic information, combined with the comprehensive phenotypic information that we are accumulating in our Oryzabase, can serve as an excellent genotype-phenotype association resource for analyzing rice functional and structural evolution, and the associated diversity of the Oryza genus. Here we integrate our previous and future phenotypic/habitat information and newly determined genotype information into a united repository, named OryzaGenome, providing the variant information with hyperlinks to Oryzabase. The current version of OryzaGenome includes genotype information of 446 O. rufipogon accessions derived by imputation and of 17 accessions derived by imputation-free deep sequencing. Two variant viewers are implemented: SNP Viewer as a conventional genome browser interface and Variant Table as a text-based browser for precise inspection of each variant one by one. Portable VCF (variant call format) file or tab-delimited file download is also available. Following these SNP (single nucleotide polymorphism) data, reference pseudomolecules/scaffolds/contigs and genome-wide variation information for almost all of the closely and distantly related wild Oryza species from the NIG Wild Rice Collection will be available in future releases. All of the resources can be accessed through http://viewer.shigen.info/oryzagenome/. PMID:26578696

  14. Evaluation of genomic island predictors using a comparative genomics approach

    Directory of Open Access Journals (Sweden)

    Brinkman Fiona SL

    2008-08-01

    Full Text Available Abstract Background Genomic islands (GIs are clusters of genes in prokaryotic genomes of probable horizontal origin. GIs are disproportionately associated with microbial adaptations of medical or environmental interest. Recently, multiple programs for automated detection of GIs have been developed that utilize sequence composition characteristics, such as G+C ratio and dinucleotide bias. To robustly evaluate the accuracy of such methods, we propose that a dataset of GIs be constructed using criteria that are independent of sequence composition-based analysis approaches. Results We developed a comparative genomics approach (IslandPick that identifies both very probable islands and non-island regions. The approach involves 1 flexible, automated selection of comparative genomes for each query genome, using a distance function that picks appropriate genomes for identification of GIs, 2 identification of regions unique to the query genome, compared with the chosen genomes (positive dataset and 3 identification of regions conserved across all genomes (negative dataset. Using our constructed datasets, we investigated the accuracy of several sequence composition-based GI prediction tools. Conclusion Our results indicate that AlienHunter has the highest recall, but the lowest measured precision, while SIGI-HMM is the most precise method. SIGI-HMM and IslandPath/DIMOB have comparable overall highest accuracy. Our comparative genomics approach, IslandPick, was the most accurate, compared with a curated list of GIs, indicating that we have constructed suitable datasets. This represents the first evaluation, using diverse and, independent datasets that were not artificially constructed, of the accuracy of several sequence composition-based GI predictors. The caveats associated with this analysis and proposals for optimal island prediction are discussed.

  15. Role of bacterial infection in the epigenetic regulation of Wnt antagonist WIF1 by PRC2 protein EZH2

    OpenAIRE

    Roy, Badal C.; Subramaniam, Dharmalingam; Ahmed, Ishfaq; Jala, Venkatakrishna R.; Hester, Christina; Greiner, K. Allen; Haribabu, Bodduluri; Anant, Shrikant; Umar, Shahid

    2014-01-01

    The Enhancer of Zeste Homolog-2 (EZH2) represses gene transcription through histone H3 lysine-27-trimethylation (H3K27me3). Citrobacter rodentium (CR) promotes crypt hyperplasia and tumorigenesis by aberrantly regulating Wnt/β-catenin signaling. We aimed at investigating EZH2’s role in epigenetically regulating Wnt/β-catenin signaling following bacterial infection. NIH:Swiss outbred and Apc Min/+ mice were infected with CR (108cfu); BLT1−/−ApcMin/+ mice, AOM/DSS-treated mice and de-identified...

  16. Retinoic acid expression associates with enhanced IL-22 production by γδ T cells and innate lymphoid cells and attenuation of intestinal inflammation

    OpenAIRE

    Mills, Kingston; Raverdeau, Mathilde

    2013-01-01

    PUBLISHED Retinoic acid (RA), a vitamin A metabolite, modulates mucosal T helper cell responses. Here we examined the role of RA in regulating IL-22 production by γδ T cells and innate lymphoid cells in intestinal inflammation. RA significantly enhanced IL-22 production by γδ T cells stimulated in vitro with IL-1β or IL-18 and IL-23. In vivo RA attenuated colon inflammation induced by dextran sodium sulfate treatment or Citrobacter rodentium infection. This was associated with a significan...

  17. Activation of p38α in T cells regulates the intestinal host defense against attaching and effacing bacterial infections

    OpenAIRE

    Shim, Eun-Jin; Bang, Bo Ram; Kang, Seung-Goo; Ma, Jianhui; Otsuka, Motoyuki; Kang, Jiman; Stahl, Martin; Han, Jiahuai; Xiao, Changchun; Vallance, Bruce A.; Kang, Young Jun

    2013-01-01

    Intestinal infections by attaching and effacing (A/E) bacterial pathogens cause severe colitis and bloody diarrhea. Although p38α in intestine epithelial cells (IEC) plays an important role in promoting protection against A/E bacteria by regulating T cell recruitment, its impact on immune responses remains unclear. In this study, we show that activation of p38α in T cells is critical for the clearance of the A/E pathogen Citrobacter rodentium. Mice deficient of p38α in T cells, but not in mac...

  18. Bioinformatics for plant genome annotation

    NARCIS (Netherlands)

    Fiers, M.W.E.J.

    2006-01-01

    Large amounts of genome sequence data are available and much more will become available in the near future. A DNA sequence alone has, however, limited use. Genome annotation is required to assign biological interpretation to the DNA sequence. This thesis describ

  19. Public health genomics in Europe

    Directory of Open Access Journals (Sweden)

    Stefania Boccia

    2006-12-01

    Full Text Available The challenge of integrating genomics into public health The Human Genome Project was completed in 2003. Expectations are high that new knowledge and technologies arising from the project will soon contribute to the improvement of individual and population health. Yet, approaches in public health have so far not broadly used molecular knowledge of individual genetic susceptibility for achieving their goals. However, in the past decade there has been increasing awareness that advances in genomics can be utilised in public health in the near future. It is our opinion that it is of major importance to start discussion of this option and its possible consequences early enough. This thematic issue starts from the premise that public health approaches can and should no longer ignore the advances made in genomics.We are seeing the emergence of the multidisciplinary field of public health genomics that deals with these opportunities and challenges. According to the statements of an expert group that discussed public health genomics concepts in Bellagio in 2005, public health genomics can be defined as:“The responsible and effective translation of genome-based knowledge and technologies for the benefit of population health (Bellagio Report.”

  20. Genomic medicine: too great expectations?

    Science.gov (United States)

    O'Rourke, P P

    2013-08-01

    As advances in genomic medicine have captured the interest and enthusiasm of the public, an unintended consequence has been the creation of unrealistic expectations. Because these expectations may have a negative impact on individuals as well as genomics in general, it is important that they be understood and confronted.

  1. Fueling Future with Algal Genomics

    Energy Technology Data Exchange (ETDEWEB)

    Grigoriev, Igor

    2012-07-05

    Algae constitute a major component of fundamental eukaryotic diversity, play profound roles in the carbon cycle, and are prominent candidates for biofuel production. The US Department of Energy Joint Genome Institute (JGI) is leading the world in algal genome sequencing (http://jgi.doe.gov/Algae) and contributes of the algal genome projects worldwide (GOLD database, 2012). The sequenced algal genomes offer catalogs of genes, networks, and pathways. The sequenced first of its kind genomes of a haptophyte E.huxleyii, chlorarachniophyte B.natans, and cryptophyte G.theta fill the gaps in the eukaryotic tree of life and carry unique genes and pathways as well as molecular fossils of secondary endosymbiosis. Natural adaptation to conditions critical for industrial production is encoded in algal genomes, for example, growth of A.anophagefferens at very high cell densities during the harmful algae blooms or a global distribution across diverse environments of E.huxleyii, able to live on sparse nutrients due to its expanded pan-genome. Communications and signaling pathways can be derived from simple symbiotic systems like lichens or complex marine algae metagenomes. Collectively these datasets derived from algal genomics contribute to building a comprehensive parts list essential for algal biofuel development.

  2. Parameters for accurate genome alignment

    Directory of Open Access Journals (Sweden)

    Hamada Michiaki

    2010-02-01

    Full Text Available Abstract Background Genome sequence alignments form the basis of much research. Genome alignment depends on various mundane but critical choices, such as how to mask repeats and which score parameters to use. Surprisingly, there has been no large-scale assessment of these choices using real genomic data. Moreover, rigorous procedures to control the rate of spurious alignment have not been employed. Results We have assessed 495 combinations of score parameters for alignment of animal, plant, and fungal genomes. As our gold-standard of accuracy, we used genome alignments implied by multiple alignments of proteins and of structural RNAs. We found the HOXD scoring schemes underlying alignments in the UCSC genome database to be far from optimal, and suggest better parameters. Higher values of the X-drop parameter are not always better. E-values accurately indicate the rate of spurious alignment, but only if tandem repeats are masked in a non-standard way. Finally, we show that γ-centroid (probabilistic alignment can find highly reliable subsets of aligned bases. Conclusions These results enable more accurate genome alignment, with reliability measures for local alignments and for individual aligned bases. This study was made possible by our new software, LAST, which can align vertebrate genomes in a few hours http://last.cbrc.jp/.

  3. The promise of insect genomics

    DEFF Research Database (Denmark)

    Grimmelikhuijzen, Cornelis J P; Cazzamali, Giuseppe; Williamson, Michael;

    2007-01-01

    Insects are the largest animal group in the world and are ecologically and economically extremely important. This importance of insects is reflected by the existence of currently 24 insect genome projects. Our perspective discusses the state-of-the-art of these genome projects and the impacts...... that they have on basic insect science and pest control....

  4. Genome instability in Alzheimer disease

    DEFF Research Database (Denmark)

    Hou, Yujun; Song, Hyundong; Croteau, Deborah L;

    2016-01-01

    to the development of noninvasive treatment strategies. Further investigations into the molecular mechanisms connecting DNA damage to AD pathology may help to develop novel treatment strategies for this debilitating disease. Here we provide an overview of the role of genome instability and DNA repair deficiency...... in AD pathology and discuss research strategies that include genome instability as a component....

  5. Genomic Heritability: What Is It?

    DEFF Research Database (Denmark)

    de los Campos, Gustavo; Sorensen, Daniel; Gianola, Daniel

    2015-01-01

    of phenotypic variance that can be explained by regression on molecular markers. This is so even though some of the assumptions commonly adopted for data analysis are at odds with important quantitative genetic concepts. In this article we develop theory that leads to a precise definition of parameters arising...... in high dimensional genomic regressions; we focus on the so-called genomic heritability: the proportion of variance of a trait that can be explained (in the population) by a linear regression on a set of markers. We propose a definition of this parameter that is framed within the classical quantitative...... genetics theory and show that the genomic heritability and the trait heritability parameters are equal only when all causal variants are typed. Further, we discuss how the genomic variance and genomic heritability, defined as quantitative genetic parameters, relate to parameters of statistical models...

  6. The UCSC Archaeal Genome Browser: 2012 update

    OpenAIRE

    Chan, Patricia P.; Holmes, Andrew D.; Smith, Andrew M.; Tran, Danny; Lowe, Todd M.

    2011-01-01

    The UCSC Archaeal Genome Browser (http://archaea.ucsc.edu) offers a graphical web-based resource for exploration and discovery within archaeal and other selected microbial genomes. By bringing together existing gene annotations, gene expression data, multiple-genome alignments, pre-computed sequence comparisons and other specialized analysis tracks, the genome browser is a powerful aggregator of varied genomic information. The genome browser environment maintains the current look-and-feel of ...

  7. The UCSC Genome Browser database: 2015 update

    OpenAIRE

    Rosenbloom, Kate R.; Armstrong, Joel; Barber, Galt P.; Casper, Jonathan; Clawson, Hiram; Diekhans, Mark; Dreszer, Timothy R.; Fujita, Pauline A.; Guruvadoo, Luvina; Haeussler, Maximilian; Harte, Rachel A.; Heitner, Steve; Hickey, Glenn; Hinrichs, Angie S.; Hubley, Robert

    2014-01-01

    Launched in 2001 to showcase the draft human genome assembly, the UCSC Genome Browser database (http://genome.ucsc.edu) and associated tools continue to grow, providing a comprehensive resource of genome assemblies and annotations to scientists and students worldwide. Highlights of the past year include the release of a browser for the first new human genome reference assembly in 4 years in December 2013 (GRCh38, UCSC hg38), a watershed comparative genomics annotation (100-species multiple al...

  8. Privacy in the Genomic Era

    Science.gov (United States)

    NAVEED, MUHAMMAD; AYDAY, ERMAN; CLAYTON, ELLEN W.; FELLAY, JACQUES; GUNTER, CARL A.; HUBAUX, JEAN-PIERRE; MALIN, BRADLEY A.; WANG, XIAOFENG

    2015-01-01

    Genome sequencing technology has advanced at a rapid pace and it is now possible to generate highly-detailed genotypes inexpensively. The collection and analysis of such data has the potential to support various applications, including personalized medical services. While the benefits of the genomics revolution are trumpeted by the biomedical community, the increased availability of such data has major implications for personal privacy; notably because the genome has certain essential features, which include (but are not limited to) (i) an association with traits and certain diseases, (ii) identification capability (e.g., forensics), and (iii) revelation of family relationships. Moreover, direct-to-consumer DNA testing increases the likelihood that genome data will be made available in less regulated environments, such as the Internet and for-profit companies. The problem of genome data privacy thus resides at the crossroads of computer science, medicine, and public policy. While the computer scientists have addressed data privacy for various data types, there has been less attention dedicated to genomic data. Thus, the goal of this paper is to provide a systematization of knowledge for the computer science community. In doing so, we address some of the (sometimes erroneous) beliefs of this field and we report on a survey we conducted about genome data privacy with biomedical specialists. Then, after characterizing the genome privacy problem, we review the state-of-the-art regarding privacy attacks on genomic data and strategies for mitigating such attacks, as well as contextualizing these attacks from the perspective of medicine and public policy. This paper concludes with an enumeration of the challenges for genome data privacy and presents a framework to systematize the analysis of threats and the design of countermeasures as the field moves forward. PMID:26640318

  9. The Video Genome

    CERN Document Server

    Bronstein, Alexander M; Kimmel, Ron

    2010-01-01

    Fast evolution of Internet technologies has led to an explosive growth of video data available in the public domain and created unprecedented challenges in the analysis, organization, management, and control of such content. The problems encountered in video analysis such as identifying a video in a large database (e.g. detecting pirated content in YouTube), putting together video fragments, finding similarities and common ancestry between different versions of a video, have analogous counterpart problems in genetic research and analysis of DNA and protein sequences. In this paper, we exploit the analogy between genetic sequences and videos and propose an approach to video analysis motivated by genomic research. Representing video information as video DNA sequences and applying bioinformatic algorithms allows to search, match, and compare videos in large-scale databases. We show an application for content-based metadata mapping between versions of annotated video.

  10. The South Asian genome.

    Directory of Open Access Journals (Sweden)

    John C Chambers

    Full Text Available The genetic sequence variation of people from the Indian subcontinent who comprise one-quarter of the world's population, is not well described. We carried out whole genome sequencing of 168 South Asians, along with whole-exome sequencing of 147 South Asians to provide deeper characterisation of coding regions. We identify 12,962,155 autosomal sequence variants, including 2,946,861 new SNPs and 312,738 novel indels. This catalogue of SNPs and indels amongst South Asians provides the first comprehensive map of genetic variation in this major human population, and reveals evidence for selective pressures on genes involved in skin biology, metabolism, infection and immunity. Our results will accelerate the search for the genetic variants underlying susceptibility to disorders such as type-2 diabetes and cardiovascular disease which are highly prevalent amongst South Asians.

  11. Marine Bacterial Genomics

    DEFF Research Database (Denmark)

    Machado, Henrique

    For decades, terrestrial microorganisms have been used as sources of countless enzymes and chemical compounds that have been produced by pharmaceutical and biotech companies and used by mankind. There is a need for new chemical compounds, including antibiotics,new enzymatic activities and new...... microorganisms to be used as cell factories for production. Therefore exploitation of new microbial niches and use of different strategies is an opportunity to boost discoveries. Even though scientists have started to explore several habitats other than the terrestrial ones, the marine environment stands out...... as a hitherto under-explored niche. This thesis work uses high-throughput sequencing technologies on a collection of marine bacteria established during the Galathea 3 expedition, with the purpose of unraveling new biodiversity and new bioactivities. Several tools were used for genomic analysis in order...

  12. Genomics in Neurological Disorders

    Institute of Scientific and Technical Information of China (English)

    Guangchun Han; Jiya Sun; Jiajia Wang; Zhouxian Bai; Fuhai Song; Hongxing Lei

    2014-01-01

    Neurological disorders comprise a variety of complex diseases in the central nervous system, which can be roughly classified as neurodegenerative diseases and psychiatric disorders. The basic and translational research of neurological disorders has been hindered by the difficulty in accessing the pathological center (i.e., the brain) in live patients. The rapid advancement of sequencing and array technologies has made it possible to investigate the disease mechanism and biomarkers from a systems perspective. In this review, recent progresses in the discovery of novel risk genes, treatment targets and peripheral biomarkers employing genomic technologies will be dis-cussed. Our major focus will be on two of the most heavily investigated neurological disorders, namely Alzheimer’s disease and autism spectrum disorder.

  13. Linking the genomes of nonmodel teleosts through comparative genomics.

    Science.gov (United States)

    Sarropoulou, E; Nousdili, D; Magoulas, A; Kotoulas, G

    2008-01-01

    Recently the genomes of two more teleost species have been released: the medaka (Oryzias latipes), and the three-spined stickleback (Gasterosteus aculateus). The rapid developments in genomics of fish species paved the way to new and valuable research in comparative genetics and genomics. With the accumulation of information in model species, the genetic and genomic characterization of nonmodel, but economically important species, is now feasible. Furthermore, comparison of low coverage gene maps of aquacultured fish species against fully sequenced fish species will enhance the efficiency of candidate genes identification projected for quantitative trait loci (QTL) scans for traits of commercial interest. This study shows the syntenic relationship between the genomes of six different teleost species, including three fully sequenced model species: Tetraodon nigroviridis, Oryzias latipes, Gasterosteus aculateus, and three marine species of commercial and evolutionary interest: Sparus aurata, Dicentrarchus labrax, Oreochromis spp. All three commercial fish species belong to the order Perciformes, which is the richest in number of species (approximately 10,000) but poor in terms of available genomic information and tools. Syntenic relationships were established by using 800 EST and microsatellites sequences successfully mapped on the RH map of seabream. Comparison to the stickleback genome produced most positive BLAT hits (58%) followed by medaka (32%) and Tetraodon (30%). Thus, stickleback was used as the major stepping stone to compare seabass and tilapia to seabream. In addition to the significance for the aquaculture industry, this approach can encompass important ecological and evolutionary implications. PMID:18297360

  14. Human myoblast genome therapy

    Institute of Scientific and Technical Information of China (English)

    Peter K Law; Leo A Bockeria; Choong-Chin Liew; Danlin M Law; Ping Lu; Eugene KW Sim; Khawja H Haider; Lei Ye; Xun Li; Margarita N Vakhromeeva; Ilia I Berishvili

    2006-01-01

    Human Myoblast Genome Therapy (HMGT) is a platform technology of cell transplantation, nuclear transfer, and tissue engineering. Unlike stem cells, myoblasts are differentiated, immature cells destined to become muscles. Myoblasts cultured from satellite cells of adult muscle biopsies survive, develop, and function to revitalize degenerative muscles upon transplantation. Injection injury activates regeneration of host myofibers that fuse with the engrafted myoblasts, sharing their nuclei in a common gene pool of the syncytium. Thus, through nuclear transfer and complementation, the normal human genome can be transferred into muscles of patients with genetic disorders to achieve phenotype repair or disease prevention. Myoblasts are safe and efficient gene transfer vehicles endogenous to muscles that constitute 50% of body weight. Results of over 280 HMGT procedures on Duchenne Muscular Dystrophy (DMD) subjects in the past 15 years demonstrated absolute safety. Myoblast-injected DMD muscles showed improved histology.Strength increase at 18 months post-operatively averaged 123%. In another application of HMGT on ischemic cardiomyopathy, the first human myoblast transfer into porcine myocardium revealed that it was safe and effective. Clinical trials on approximately 220 severe cardiomyopathy patients in 15 countries showed a <10% mortality. Most subjects received autologous cells implanted on the epicardial surface during coronory artery bypass graft, or injected on the endomyocardial surface percutaneously through guiding catheters. Significant increases in left ventricular ejection fraction, wall thickness, and wall motion have been reported, with reduction in perfusion defective areas, angina, and shortness of breath. As a new modality of treatment for disease in the skeletal muscle or myocardium, HMGT emerged as safe and effective. Large randomized multi-center trials are under way to confirm these preliminary results. The future of HMGT is bright and exciting

  15. Inheritance of the yeast mitochondrial genome

    DEFF Research Database (Denmark)

    Piskur, Jure

    1994-01-01

    Mitochondrion, extrachromosomal genetics, intergenic sequences, genome size, mitochondrial DNA, petite mutation, yeast......Mitochondrion, extrachromosomal genetics, intergenic sequences, genome size, mitochondrial DNA, petite mutation, yeast...

  16. Plantagora: modeling whole genome sequencing and assembly of plant genomes.

    Directory of Open Access Journals (Sweden)

    Roger Barthelson

    Full Text Available BACKGROUND: Genomics studies are being revolutionized by the next generation sequencing technologies, which have made whole genome sequencing much more accessible to the average researcher. Whole genome sequencing with the new technologies is a developing art that, despite the large volumes of data that can be produced, may still fail to provide a clear and thorough map of a genome. The Plantagora project was conceived to address specifically the gap between having the technical tools for genome sequencing and knowing precisely the best way to use them. METHODOLOGY/PRINCIPAL FINDINGS: For Plantagora, a platform was created for generating simulated reads from several different plant genomes of different sizes. The resulting read files mimicked either 454 or Illumina reads, with varying paired end spacing. Thousands of datasets of reads were created, most derived from our primary model genome, rice chromosome one. All reads were assembled with different software assemblers, including Newbler, Abyss, and SOAPdenovo, and the resulting assemblies were evaluated by an extensive battery of metrics chosen for these studies. The metrics included both statistics of the assembly sequences and fidelity-related measures derived by alignment of the assemblies to the original genome source for the reads. The results were presented in a website, which includes a data graphing tool, all created to help the user compare rapidly the feasibility and effectiveness of different sequencing and assembly strategies prior to testing an approach in the lab. Some of our own conclusions regarding the different strategies were also recorded on the website. CONCLUSIONS/SIGNIFICANCE: Plantagora provides a substantial body of information for comparing different approaches to sequencing a plant genome, and some conclusions regarding some of the specific approaches. Plantagora also provides a platform of metrics and tools for studying the process of sequencing and assembly

  17. Genome Annotation Transfer Utility (GATU: rapid annotation of viral genomes using a closely related reference genome

    Directory of Open Access Journals (Sweden)

    Upton Chris

    2006-06-01

    Full Text Available Abstract Background Since DNA sequencing has become easier and cheaper, an increasing number of closely related viral genomes have been sequenced. However, many of these have been deposited in GenBank without annotations, severely limiting their value to researchers. While maintaining comprehensive genomic databases for a set of virus families at the Viral Bioinformatics Resource Center http://www.biovirus.org and Viral Bioinformatics – Canada http://www.virology.ca, we found that researchers were unnecessarily spending time annotating viral genomes that were close relatives of already annotated viruses. We have therefore designed and implemented a novel tool, Genome Annotation Transfer Utility (GATU, to transfer annotations from a previously annotated reference genome to a new target genome, thereby greatly reducing this laborious task. Results GATU transfers annotations from a reference genome to a closely related target genome, while still giving the user final control over which annotations should be included. GATU also detects open reading frames present in the target but not the reference genome and provides the user with a variety of bioinformatics tools to quickly determine if these ORFs should also be included in the annotation. After this process is complete, GATU saves the newly annotated genome as a GenBank, EMBL or XML-format file. The software is coded in Java and runs on a variety of computer platforms. Its user-friendly Graphical User Interface is specifically designed for users trained in the biological sciences. Conclusion GATU greatly simplifies the initial stages of genome annotation by using a closely related genome as a reference. It is not intended to be a gene prediction tool or a "complete" annotation system, but we have found that it significantly reduces the time required for annotation of genes and mature peptides as well as helping to standardize gene names between related organisms by transferring reference genome

  18. Molecular characterization of encoding plasmid-mediated ESBLs and AmpC β-lactamases genes in Citrobacter freundii%质粒介导产ESBLs与AmpCβ-内酰胺酶基因弗氏柠檬酸杆菌的研究

    Institute of Scientific and Technical Information of China (English)

    陈坚; 余方友

    2011-01-01

    OBJECTIVE To investigate the resistant mechanism of Citrobacter freundii which coexisted with ESBLs and AmpC genes. METHODS A multi-resistant Citrobacter freundii was isolated from hospital by VITEK-60 system. The detection of ESBLs was performed by the CLSI-recommended confirmatory test, Cefoxitin three-dimentional test was presented to identify AmpC β-lactamases, the mimimal inhibitative concentration (MIC) was determined by E-test. Polymerase chain reaction(PCR) and sequencing were carried out for analyzing the encoding genes of β-lactamases. Conjugation study was performed to determine whether resistant genes were likely transferred by plasmid. RESULTS The isolate was highly resistant to ceftazidime (MICs,96 jug/ml), cefotaxime (MlCs,96 μg/ml), cefoxitin(MICs.256 μg/ml) , aztreonam(MICs, 192 fig/ml) , ampicillin(MICs,>256 μg/ml) and sinomin compositea(MICs,>32 fig/ml). The clinical isolate produced AmpCs and ESBLs. The presence of blacrx-M-3 and blaCMY-2 of clinical isolate were identified by PCR and sequenced. Those genes of clinical isolate could be transferred to Escherichia coli J53 through conjugation. CONCLUSION Citrobacter freundii carries ESBLs and AmpC β-lactamases genes synchronously, which were mediated by plasmid.%目的 研究一株同时产ESBLs和AmpC β-内酰胺酶弗氏柠檬酸杆菌(CFR)的耐药机制.方法 2008年1月从临床尿液标本中分离出多药耐药弗氏柠檬酸杆菌1株,采用双纸片扩散法检测产ESBLs,头孢西丁三维试验检测AmpC酶,E-test法测定抗菌药物最低抑菌浓度(MIC),聚合酶链反应(PCR)检测产ESBss和AmpC酶基因,DNA测序决定基因型;接合试验测定耐药基因的转移性.结果 临床分离出一株同时产ESBLs和AmpCβ-内酰胺酶的多药耐药弗氏柠檬酸杆菌,对头孢他啶、头孢噻肟、头孢西丁、氨曲南、氨苄西林、磺胺甲噁唑/甲氧苄啶的MIC分别为96、96、256、192、>256、>32 μg/ml,PCR扩增及测序

  19. Components of Adenovirus Genome Packaging

    Science.gov (United States)

    Ahi, Yadvinder S.; Mittal, Suresh K.

    2016-01-01

    Adenoviruses (AdVs) are icosahedral viruses with double-stranded DNA (dsDNA) genomes. Genome packaging in AdV is thought to be similar to that seen in dsDNA containing icosahedral bacteriophages and herpesviruses. Specific recognition of the AdV genome is mediated by a packaging domain located close to the left end of the viral genome and is mediated by the viral packaging machinery. Our understanding of the role of various components of the viral packaging machinery in AdV genome packaging has greatly advanced in recent years. Characterization of empty capsids assembled in the absence of one or more components involved in packaging, identification of the unique vertex, and demonstration of the role of IVa2, the putative packaging ATPase, in genome packaging have provided compelling evidence that AdVs follow a sequential assembly pathway. This review provides a detailed discussion on the functions of the various viral and cellular factors involved in AdV genome packaging. We conclude by briefly discussing the roles of the empty capsids, assembly intermediates, scaffolding proteins, portal vertex and DNA encapsidating enzymes in AdV assembly and packaging. PMID:27721809

  20. The genome of Eucalyptus grandis

    Energy Technology Data Exchange (ETDEWEB)

    Myburg, Alexander A.; Grattapaglia, Dario; Tuskan, Gerald A.; Hellsten, Uffe; Hayes, Richard D.; Grimwood, Jane; Jenkins, Jerry; Lindquist, Erika; Tice, Hope; Bauer, Diane; Goodstein, David M.; Dubchak, Inna; Poliakov, Alexandre; Mizrachi, Eshchar; Kullan, Anand R. K.; Hussey, Steven G.; Pinard, Desre; van der Merwe, Karen; Singh, Pooja; van Jaarsveld, Ida; Silva-Junior, Orzenil B.; Togawa, Roberto C.; Pappas, Marilia R.; Faria, Danielle A.; Sansaloni, Carolina P.; Petroli, Cesar D.; Yang, Xiaohan; Ranjan, Priya; Tschaplinski, Timothy J.; Ye, Chu-Yu; Li, Ting; Sterck, Lieven; Vanneste, Kevin; Murat, Florent; Soler, Marçal; Clemente, Hélène San; Saidi, Naijib; Cassan-Wang, Hua; Dunand, Christophe; Hefer, Charles A.; Bornberg-Bauer, Erich; Kersting, Anna R.; Vining, Kelly; Amarasinghe, Vindhya; Ranik, Martin; Naithani, Sushma; Elser, Justin; Boyd, Alexander E.; Liston, Aaron; Spatafora, Joseph W.; Dharmwardhana, Palitha; Raja, Rajani; Sullivan, Christopher; Romanel, Elisson; Alves-Ferreira, Marcio; Külheim, Carsten; Foley, William; Carocha, Victor; Paiva, Jorge; Kudrna, David; Brommonschenkel, Sergio H.; Pasquali, Giancarlo; Byrne, Margaret; Rigault, Philippe; Tibbits, Josquin; Spokevicius, Antanas; Jones, Rebecca C.; Steane, Dorothy A.; Vaillancourt, René E.; Potts, Brad M.; Joubert, Fourie; Barry, Kerrie; Pappas, Georgios J.; Strauss, Steven H.; Jaiswal, Pankaj; Grima-Pettenati, Jacqueline; Salse, Jérôme; Van de Peer, Yves; Rokhsar, Daniel S.; Schmutz, Jeremy

    2014-06-11

    Eucalypts are the world s most widely planted hardwood trees. Their broad adaptability, rich species diversity, fast growth and superior multipurpose wood, have made them a global renewable resource of fiber and energy that mitigates human pressures on natural forests. We sequenced and assembled >94% of the 640 Mbp genome of Eucalyptus grandis into its 11 chromosomes. A set of 36,376 protein coding genes were predicted revealing that 34% occur in tandem duplications, the largest proportion found thus far in any plant genome. Eucalypts also show the highest diversity of genes for plant specialized metabolism that act as chemical defence against biotic agents and provide unique pharmaceutical oils. Resequencing of a set of inbred tree genomes revealed regions of strongly conserved heterozygosity, likely hotspots of inbreeding depression. The resequenced genome of the sister species E. globulus underscored the high inter-specific genome colinearity despite substantial genome size variation in the genus. The genome of E. grandis is the first reference for the early diverging Rosid order Myrtales and is placed here basal to the Eurosids. This resource expands knowledge on the unique biology of large woody perennials and provides a powerful tool to accelerate comparative biology, breeding and biotechnology.

  1. Genome size variation in the genus Avena.

    Science.gov (United States)

    Yan, Honghai; Martin, Sara L; Bekele, Wubishet A; Latta, Robert G; Diederichsen, Axel; Peng, Yuanying; Tinker, Nicholas A

    2016-03-01

    Genome size is an indicator of evolutionary distance and a metric for genome characterization. Here, we report accurate estimates of genome size in 99 accessions from 26 species of Avena. We demonstrate that the average genome size of C genome diploid species (2C = 10.26 pg) is 15% larger than that of A genome species (2C = 8.95 pg), and that this difference likely accounts for a progression of size among tetraploid species, where AB genome configuration had similar genome sizes (average 2C = 25.74 pg). Genome size was mostly consistent within species and in general agreement with current information about evolutionary distance among species. Results also suggest that most of the polyploid species in Avena have experienced genome downsizing in relation to their diploid progenitors. Genome size measurements could provide additional quality control for species identification in germplasm collections, especially in cases where diploid and polyploid species have similar morphology.

  2. Genome Modeling System: A Knowledge Management Platform for Genomics.

    Directory of Open Access Journals (Sweden)

    Malachi Griffith

    2015-07-01

    Full Text Available In this work, we present the Genome Modeling System (GMS, an analysis information management system capable of executing automated genome analysis pipelines at a massive scale. The GMS framework provides detailed tracking of samples and data coupled with reliable and repeatable analysis pipelines. The GMS also serves as a platform for bioinformatics development, allowing a large team to collaborate on data analysis, or an individual researcher to leverage the work of others effectively within its data management system. Rather than separating ad-hoc analysis from rigorous, reproducible pipelines, the GMS promotes systematic integration between the two. As a demonstration of the GMS, we performed an integrated analysis of whole genome, exome and transcriptome sequencing data from a breast cancer cell line (HCC1395 and matched lymphoblastoid line (HCC1395BL. These data are available for users to test the software, complete tutorials and develop novel GMS pipeline configurations. The GMS is available at https://github.com/genome/gms.

  3. Genomic prediction using QTL derived from whole genome sequence data

    DEFF Research Database (Denmark)

    Brøndum, Rasmus Froberg; Su, Guosheng; Janss, Luc;

    This study investigated the gain in accuracy of genomic prediction when a small number of significant variants from single marker analysis based on whole genome sequence data were added to the regular 54k SNP data. Analyses were performed for Nordic Holstein and Danish Jersey animals, using either...... a genomic BLUP or a Bayesian variable selection model. When using the genomic BLUP model, results showed increases in accuracy of up to two percentage points for production traits in both Holstein and Jersey animals by including the extra variants in the analysis, and an extra 1.5 percentage points...... for fertility in Jersey animals. When using a Bayesian model accuracies were generally higher, but only small increases in accuracy of up to 0.6 percentage points were observed for the Holstein animals when including the extra markers, while both increases and decreases were observed for Jersey...

  4. Capturing prokaryotic dark matter genomes.

    Science.gov (United States)

    Gasc, Cyrielle; Ribière, Céline; Parisot, Nicolas; Beugnot, Réjane; Defois, Clémence; Petit-Biderre, Corinne; Boucher, Delphine; Peyretaillade, Eric; Peyret, Pierre

    2015-12-01

    Prokaryotes are the most diverse and abundant cellular life forms on Earth. Most of them, identified by indirect molecular approaches, belong to microbial dark matter. The advent of metagenomic and single-cell genomic approaches has highlighted the metabolic capabilities of numerous members of this dark matter through genome reconstruction. Thus, linking functions back to the species has revolutionized our understanding of how ecosystem function is sustained by the microbial world. This review will present discoveries acquired through the illumination of prokaryotic dark matter genomes by these innovative approaches.

  5. Human genome. 1993 Program report

    Energy Technology Data Exchange (ETDEWEB)

    1994-03-01

    The purpose of this report is to update the Human Genome 1991-92 Program Report and provide new information on the DOE genome program to researchers, program managers, other government agencies, and the interested public. This FY 1993 supplement includes abstracts of 60 new or renewed projects and listings of 112 continuing and 28 completed projects. These two reports, taken together, present the most complete published view of the DOE Human Genome Program through FY 1993. Research is progressing rapidly toward 15-year goals of mapping and sequencing the DNA of each of the 24 different human chromosomes.

  6. Capturing prokaryotic dark matter genomes.

    Science.gov (United States)

    Gasc, Cyrielle; Ribière, Céline; Parisot, Nicolas; Beugnot, Réjane; Defois, Clémence; Petit-Biderre, Corinne; Boucher, Delphine; Peyretaillade, Eric; Peyret, Pierre

    2015-12-01

    Prokaryotes are the most diverse and abundant cellular life forms on Earth. Most of them, identified by indirect molecular approaches, belong to microbial dark matter. The advent of metagenomic and single-cell genomic approaches has highlighted the metabolic capabilities of numerous members of this dark matter through genome reconstruction. Thus, linking functions back to the species has revolutionized our understanding of how ecosystem function is sustained by the microbial world. This review will present discoveries acquired through the illumination of prokaryotic dark matter genomes by these innovative approaches. PMID:26100932

  7. Identification of genomic sites for CRISPR/Cas9-based genome editing in the Vitis vinifera genome

    Science.gov (United States)

    CRISPR/Cas9 has been recently demonstrated as an effective and popular genome editing tool for modifying genomes of human, animals, microorganisms, and plants. Success of such genome editing is highly dependent on the availability of suitable target sites in the genomes to be edited. Many specific t...

  8. Challenges in Whole-Genome Annotation of Pyrosequenced Eukaryotic Genomes

    Energy Technology Data Exchange (ETDEWEB)

    Kuo, Alan; Grigoriev, Igor

    2009-04-17

    Pyrosequencing technologies such as 454/Roche and Solexa/Illumina vastly lower the cost of nucleotide sequencing compared to the traditional Sanger method, and thus promise to greatly expand the number of sequenced eukaryotic genomes. However, the new technologies also bring new challenges such as shorter reads and new kinds and higher rates of sequencing errors, which complicate genome assembly and gene prediction. At JGI we are deploying 454 technology for the sequencing and assembly of ever-larger eukaryotic genomes. Here we describe our first whole-genome annotation of a purely 454-sequenced fungal genome that is larger than a yeast (>30 Mbp). The pezizomycotine (filamentous ascomycote) Aspergillus carbonarius belongs to the Aspergillus section Nigri species complex, members of which are significant as platforms for bioenergy and bioindustrial technology, as members of soil microbial communities and players in the global carbon cycle, and as agricultural toxigens. Application of a modified version of the standard JGI Annotation Pipeline has so far predicted ~;;10k genes. ~;;12percent of these preliminary annotations suffer a potential frameshift error, which is somewhat higher than the ~;;9percent rate in the Sanger-sequenced and conventionally assembled and annotated genome of fellow Aspergillus section Nigri member A. niger. Also,>90percent of A. niger genes have potential homologs in the A. carbonarius preliminary annotation. Weconclude, and with further annotation and comparative analysis expect to confirm, that 454 sequencing strategies provide a promising substrate for annotation of modestly sized eukaryotic genomes. We will also present results of annotation of a number of other pyrosequenced fungal genomes of bioenergy interest.

  9. The Materials Genome Project

    Science.gov (United States)

    Aourag, H.

    2008-09-01

    In the past, the search for new and improved materials was characterized mostly by the use of empirical, trial- and-error methods. This picture of materials science has been changing as the knowledge and understanding of fundamental processes governing a material's properties and performance (namely, composition, structure, history, and environment) have increased. In a number of cases, it is now possible to predict a material's properties before it has even been manufactured thus greatly reducing the time spent on testing and development. The objective of modern materials science is to tailor a material (starting with its chemical composition, constituent phases, and microstructure) in order to obtain a desired set of properties suitable for a given application. In the short term, the traditional "empirical" methods for developing new materials will be complemented to a greater degree by theoretical predictions. In some areas, computer simulation is already used by industry to weed out costly or improbable synthesis routes. Can novel materials with optimized properties be designed by computers? Advances in modelling methods at the atomic level coupled with rapid increases in computer capabilities over the last decade have led scientists to answer this question with a resounding "yes'. The ability to design new materials from quantum mechanical principles with computers is currently one of the fastest growing and most exciting areas of theoretical research in the world. The methods allow scientists to evaluate and prescreen new materials "in silico" (in vitro), rather than through time consuming experimentation. The Materials Genome Project is to pursue the theory of large scale modeling as well as powerful methods to construct new materials, with optimized properties. Indeed, it is the intimate synergy between our ability to predict accurately from quantum theory how atoms can be assembled to form new materials and our capacity to synthesize novel materials atom

  10. Invisible genomes: the genomics revolution and patenting practice.

    Science.gov (United States)

    Bostanci, Adam; Calvert, Jane

    2008-03-01

    In the mid-1990s, the company Human Genome Sciences submitted three potentially revolutionary patent applications to the US Patent and Trademark Office, each of which claimed the entire genome sequence of a microorganism. The patent examiners, however, objected to these applications, and after negotiation they were eventually re-written to resemble more traditional gene patents. In this paper, which is based on a study of the patent examination files, we examine the reasons why these patent applications were unsuccessful in their original form. We show that with respect to utility and novelty, the patent attorney's case built on an understanding of the genome as a computer-related invention. The patent examiners did not object to the patenting of complete genome sequences as computer-related inventions on moral grounds or in terms of the distinction between a discovery and an invention. Instead, their objections were based on classification, rules and procedure. Rather than patent examiners having a notion of a genome that should not be patented, the notion of a 'genome', and the ways in which it may be different from a 'gene', played no role in these debates. We discuss the consequences of our findings for patenting in the biosciences. PMID:18331958

  11. Whole-genome haplotyping approaches and genomic medicine.

    Science.gov (United States)

    Glusman, Gustavo; Cox, Hannah C; Roach, Jared C

    2014-01-01

    Genomic information reported as haplotypes rather than genotypes will be increasingly important for personalized medicine. Current technologies generate diploid sequence data that is rarely resolved into its constituent haplotypes. Furthermore, paradigms for thinking about genomic information are based on interpreting genotypes rather than haplotypes. Nevertheless, haplotypes have historically been useful in contexts ranging from population genetics to disease-gene mapping efforts. The main approaches for phasing genomic sequence data are molecular haplotyping, genetic haplotyping, and population-based inference. Long-read sequencing technologies are enabling longer molecular haplotypes, and decreases in the cost of whole-genome sequencing are enabling the sequencing of whole-chromosome genetic haplotypes. Hybrid approaches combining high-throughput short-read assembly with strategic approaches that enable physical or virtual binning of reads into haplotypes are enabling multi-gene haplotypes to be generated from single individuals. These techniques can be further combined with genetic and population approaches. Here, we review advances in whole-genome haplotyping approaches and discuss the importance of haplotypes for genomic medicine. Clinical applications include diagnosis by recognition of compound heterozygosity and by phasing regulatory variation to coding variation. Haplotypes, which are more specific than less complex variants such as single nucleotide variants, also have applications in prognostics and diagnostics, in the analysis of tumors, and in typing tissue for transplantation. Future advances will include technological innovations, the application of standard metrics for evaluating haplotype quality, and the development of databases that link haplotypes to disease. PMID:25473435

  12. Gene finding in novel genomes

    Directory of Open Access Journals (Sweden)

    Korf Ian

    2004-05-01

    Full Text Available Abstract Background Computational gene prediction continues to be an important problem, especially for genomes with little experimental data. Results I introduce the SNAP gene finder which has been designed to be easily adaptable to a variety of genomes. In novel genomes without an appropriate gene finder, I demonstrate that employing a foreign gene finder can produce highly inaccurate results, and that the most compatible parameters may not come from the nearest phylogenetic neighbor. I find that foreign gene finders are more usefully employed to bootstrap parameter estimation and that the resulting parameters can be highly accurate. Conclusion Since gene prediction is sensitive to species-specific parameters, every genome needs a dedicated gene finder.

  13. Genomic Datasets for Cancer Research

    Science.gov (United States)

    A variety of datasets from genome-wide association studies of cancer and other genotype-phenotype studies, including sequencing and molecular diagnostic assays, are available to approved investigators through the Extramural National Cancer Institute Data Access Committee.

  14. Collaborators | Office of Cancer Genomics

    Science.gov (United States)

    The TARGET initiative is jointly managed within the National Cancer Institute (NCI) by the Office of Cancer Genomics (OCG)Opens in a New Tab and the Cancer Therapy Evaluation Program (CTEP)Opens in a New Tab.

  15. Genomic Resources for Cancer Epidemiology

    Science.gov (United States)

    This page provides links to research resources, complied by the Epidemiology and Genomics Research Program, that may be of interest to genetic epidemiologists conducting cancer research, but is not exhaustive.

  16. Empowering marine science through genomics

    NARCIS (Netherlands)

    Volckaert, F.A M J; Barbier, M.; Canario, A; Olsen, J.L.; Wesnigk, J; Clark, M; Boyen, C

    2008-01-01

    Marine scientists in Europe summarize their successes with genome technologies in the marine sciences and make a plea for a concerted international effort to raise greater public education for support. (C) 2008 Elsevier B.V. All rights reserved.

  17. Genomic Aspects of Research Involving Polyploid Plants

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Xiaohan [ORNL; Ye, Chuyu [ORNL; Tschaplinski, Timothy J [ORNL; Wullschleger, Stan D [ORNL; Tuskan, Gerald A [ORNL

    2011-01-01

    Almost all extant plant species have spontaneously doubled their genomes at least once in their evolutionary histories, resulting in polyploidy which provided a rich genomic resource for evolutionary processes. Moreover, superior polyploid clones have been created during the process of crop domestication. Polyploid plants generated by evolutionary processes and/or crop domestication have been the intentional or serendipitous focus of research dealing with the dynamics and consequences of genome evolution. One of the new trends in genomics research is to create synthetic polyploid plants which provide materials for studying the initial genomic changes/responses immediately after polyploid formation. Polyploid plants are also used in functional genomics research to study gene expression in a complex genomic background. In this review, we summarize the recent progress in genomics research involving ancient, young, and synthetic polyploid plants, with a focus on genome size evolution, genomics diversity, genomic rearrangement, genetic and epigenetic changes in duplicated genes, gene discovery, and comparative genomics. Implications on plant sciences including evolution, functional genomics, and plant breeding are presented. It is anticipated that polyploids will be a regular subject of genomics research in the foreseeable future as the rapid advances in DNA sequencing technology create unprecedented opportunities for discovering and monitoring genomic and transcriptomic changes in polyploid plants. The fast accumulation of knowledge on polyploid formation, maintenance, and divergence at whole-genome and subgenome levels will not only help plant biologists understand how plants have evolved and diversified, but also assist plant breeders in designing new strategies for crop improvement.

  18. 2004 Structural, Function and Evolutionary Genomics

    Energy Technology Data Exchange (ETDEWEB)

    Douglas L. Brutlag Nancy Ryan Gray

    2005-03-23

    This Gordon conference will cover the areas of structural, functional and evolutionary genomics. It will take a systematic approach to genomics, examining the evolution of proteins, protein functional sites, protein-protein interactions, regulatory networks, and metabolic networks. Emphasis will be placed on what we can learn from comparative genomics and entire genomes and proteomes.

  19. International network of cancer genome projects

    NARCIS (Netherlands)

    Hudson, Thomas J.; Anderson, Warwick; Aretz, Axel; Barker, Anna D.; Bell, Cindy; Bernabe, Rosa R.; Bhan, M. K.; Calvo, Fabien; Eerola, Iiro; Gerhard, Daniela S.; Guttmacher, Alan; Guyer, Mark; Hemsley, Fiona M.; Jennings, Jennifer L.; Kerr, David; Klatt, Peter; Kolar, Patrik; Kusuda, Jun; Lane, David P.; Laplace, Frank; Lu, Youyong; Nettekoven, Gerd; Ozenberger, Brad; Peterson, Jane; Rao, T. S.; Remacle, Jacques; Schafer, Alan J.; Shibata, Tatsuhiro; Stratton, Michael R.; Vockley, Joseph G.; Watanabe, Koichi; Yang, Huanming; Yuen, Matthew M. F.; Knoppers, M.; Bobrow, Martin; Cambon-Thomsen, Anne; Dressler, Lynn G.; Dyke, Stephanie O. M.; Joly, Yann; Kato, Kazuto; Kennedy, Karen L.; Nicolas, Pilar; Parker, Michael J.; Rial-Sebbag, Emmanuelle; Romeo-Casabona, Carlos M.; Shaw, Kenna M.; Wallace, Susan; Wiesner, Georgia L.; Zeps, Nikolajs; Lichter, Peter; Biankin, Andrew V.; Chabannon, Christian; Chin, Lynda; Clement, Bruno; de Alava, Enrique; Degos, Francoise; Ferguson, Martin L.; Geary, Peter; Hayes, D. Neil; Johns, Amber L.; Nakagawa, Hidewaki; Penny, Robert; Piris, Miguel A.; Sarin, Rajiv; Scarpa, Aldo; Shibata, Tatsuhiro; van de Vijver, Marc; Futreal, P. Andrew; Aburatani, Hiroyuki; Bayes, Monica; Bowtell, David D. L.; Campbell, Peter J.; Estivill, Xavier; Grimmond, Sean M.; Gut, Ivo; Hirst, Martin; Lopez-Otin, Carlos; Majumder, Partha; Marra, Marco; Nakagawa, Hidewaki; Ning, Zemin; Puente, Xose S.; Ruan, Yijun; Shibata, Tatsuhiro; Stratton, Michael R.; Stunnenberg, Hendrik G.; Swerdlow, Harold; Velculescu, Victor E.; Wilson, Richard K.; Xue, Hong H.; Yang, Liu; Spellman, Paul T.; Bader, Gary D.; Boutros, Paul C.; Campbell, Peter J.; Flicek, Paul; Getz, Gad; Guigo, Roderic; Guo, Guangwu; Haussler, David; Heath, Simon; Hubbard, Tim J.; Jiang, Tao; Jones, Steven M.; Li, Qibin; Lopez-Bigas, Nuria; Luo, Ruibang; Pearson, John V.; Puente, Xose S.; Quesada, Victor; Raphael, Benjamin J.; Sander, Chris; Shibata, Tatsuhiro; Speed, Terence P.; Stuart, Joshua M.; Teague, Jon W.; Totoki, Yasushi; Tsunoda, Tatsuhiko; Valencia, Alfonso; Wheeler, David A.; Wu, Honglong; Zhao, Shancen; Zhou, Guangyu; Stein, Lincoln D.; Guigo, Roderic; Hubbard, Tim J.; Joly, Yann; Jones, Steven M.; Lathrop, Mark; Lopez-Bigas, Nuria; Ouellette, B. F. Francis; Spellman, Paul T.; Teague, Jon W.; Thomas, Gilles; Valencia, Alfonso; Yoshida, Teruhiko; Kennedy, Karen L.; Axton, Myles; Dyke, Stephanie O. M.; Futreal, P. Andrew; Gunter, Chris; Guyer, Mark; McPherson, John D.; Miller, Linda J.; Ozenberger, Brad; Kasprzyk, Arek; Zhang, Junjun; Haider, Syed A.; Wang, Jianxin; Yung, Christina K.; Cross, Anthony; Liang, Yong; Gnaneshan, Saravanamuttu; Guberman, Jonathan; Hsu, Jack; Bobrow, Martin; Chalmers, Don R. C.; Hasel, Karl W.; Joly, Yann; Kaan, Terry S. H.; Kennedy, Karen L.; Knoppers, Bartha M.; Lowrance, William W.; Masui, Tohru; Nicolas, Pilar; Rial-Sebbag, Emmanuelle; Rodriguez, Laura Lyman; Vergely, Catherine; Yoshida, Teruhiko; Grimmond, Sean M.; Biankin, Andrew V.; Bowtell, David D. L.; Cloonan, Nicole; Defazio, Anna; Eshleman, James R.; Etemadmoghadam, Dariush; Gardiner, Brooke A.; Kench, James G.; Scarpa, Aldo; Sutherland, Robert L.; Tempero, Margaret A.; Waddell, Nicola J.; Wilson, Peter J.; Gallinger, Steve; Tsao, Ming-Sound; Shaw, Patricia A.; Petersen, Gloria M.; Mukhopadhyay, Debabrata; Chin, Lynda; DePinho, Ronald A.; Thayer, Sarah; Muthuswamy, Lakshmi; Shazand, Kamran; Beck, Timothy; Sam, Michelle; Timms, Lee; Ballin, Vanessa; Lu, Youyong; Ji, Jiafu; Zhang, Xiuqing; Chen, Feng; Hu, Xueda; Zhou, Guangyu; Yang, Qi; Tian, Geng; Zhang, Lianhai; Xing, Xiaofang; Li, Xianghong; Zhu, Zhenggang; Yu, Yingyan; Yu, Jun; Yang, Huanming; Lathrop, Mark; Tost, Joerg; Brennan, Paul; Holcatova, Ivana; Zaridze, David; Brazma, Alvis; Egevad, Lars; Prokhortchouk, Egor; Banks, Rosamonde Elizabeth; Uhlen, Mathias; Cambon-Thomsen, Anne; Viksna, Juris; Ponten, Fredrik; Skryabin, Konstantin; Stratton, Michael R.; Futreal, P. Andrew; Birney, Ewan; Borg, Ake; Borresen-Dale, Anne-Lise; Caldas, Carlos; Foekens, John A.; Martin, Sancha; Reis-Filho, Jorge S.; Richardson, Andrea L.; Sotiriou, Christos; Stunnenberg, Hendrik G.; Thomas, Gilles; van de Vijver, Marc; van't Veer, Laura; Birnbaum, Daniel; Blanche, Helene; Boucher, Pascal; Boyault, Sandrine; Chabannon, Christian; Gut, Ivo; Masson-Jacquemier, Jocelyne D.; Lathrop, Mark; Pauporte, Iris; Pivot, Xavier; Vincent-Salomon, Anne; Tabone, Eric; Theillet, Charles; Thomas, Gilles; Tost, Joerg; Treilleux, Isabelle; Bioulac-Sage, Paulette; Clement, Bruno; Decaens, Thomas; Degos, Francoise; Franco, Dominique; Gut, Ivo; Gut, Marta; Heath, Simon

    2010-01-01

    The International Cancer Genome Consortium (ICGC) was launched to coordinate large-scale cancer genome studies in tumours from 50 different cancer types and/or subtypes that are of clinical and societal importance across the globe. Systematic studies of more than 25,000 cancer genomes at the genomic

  20. Reconstructing ancient genomes and epigenomes

    DEFF Research Database (Denmark)

    Orlando, Ludovic Antoine Alexandre; Gilbert, M. Thomas P.; Willerslev, Eske

    2015-01-01

    DNA studies have now progressed to whole-genome sequencing for an increasing number of ancient individuals and extinct species, as well as to epigenomic characterization. Such advances have enabled the sequencing of specimens of up to 1 million years old, which, owing to their extensive DNA damage and...... contamination, were previously not amenable to genetic analyses. In this Review, we discuss these varied technical challenges and solutions for sequencing ancient genomes and epigenomes....

  1. Expanding Genomics of Mycorrhizal Symbiosis

    Directory of Open Access Journals (Sweden)

    Alan eKuo

    2014-11-01

    Full Text Available The mycorrhizal symbiosis between soil fungi and plant roots is a ubiquitous mutualism that plays key roles in plant and soil health, and carbon and nutrient cycles. The symbiosis evolved repeatedly and independently as multiple morphological types (e.g. arbuscular [AM], ectomycorrhizal [ECM] in multiple fungal clades (e.g. phyla Glomeromycota, Ascomycota, Basidiomycota. The accessibility and culturability of many mycorrhizal partners make them ideal models for symbiosis studies. Alongside molecular, physiological, and ecological investigations, sequencing led to the first 3 mycorrhizal fungal genomes, representing 3 fungal phyla and 2 mycorrhizal types. The genome of the ECM basidiomycete Laccaria bicolor showed that the mycorrhizal lifestyle can evolve through loss of plant-degrading enzymes (PDEs and expansion of lineage-specific gene families, including short secreted protein (SSP effectors and other symbiosis genes. The genome of the ECM ascomycete Tuber melanosporum showed that the ECM type can evolve without expansion of gene families in contrast to Laccaria, and thus a different set of symbiosis genes. The genome of the AM glomeromycete Rhizophagus irregularis showed that despite enormous phylogenetic distance and morphological difference from the other 2 fungi, the symbiosis can involve similar solutions as loss of PDEs and mycorrhiza-induced SSPs. The mycorrhizal community is building on these studies with 3 large-scale initiatives. The Mycorrhizal Genomics Initiative (MGI is sequencing 35 genomes of multiple fungal clades and mycorrhizal types for phylogenomic and population analyses. 17 MGI species whose symbiosis is reconstitutable in vitro are targeted for comprehensive transcriptomics of mycorrhiza formation. MGI genomes are seeding a set of 50+ reference fungal genomes for annotating metatranscriptomes sampled from 7 diverse well-described soil sites. These 3 projects address fundamental questions about the nature and role of a

  2. Gender And The Human Genome

    Directory of Open Access Journals (Sweden)

    Chadwick Ruth

    2009-01-01

    Full Text Available Gender issues arise in relation to the human genome across a number of dimensions: the level of attention given to the nuclear genome as opposed to the mitochondrial; the level of basic scientific research; decision-making in the clinic related to both reproductive decision-making on the one hand, and diagnostic and predictive testing on the other; and wider societal implications. Feminist bioethics offers a useful perspective for addressing these issues.

  3. Genomic toolboxes for conservation biologists

    OpenAIRE

    Angeloni, F.; Wagemaker, N.; Vergeer, P.; Ouborg, N.J.

    2011-01-01

    Conservation genetics is expanding its research horizon with a genomic approach, by incorporating the modern techniques of next-generation sequencing (NGS). Application of NGS overcomes many limitations of conservation genetics. First, NGS allows for genome-wide screening of markers, which may lead to a more representative estimation of genetic variation within and between populations. Second, NGS allows for distinction between neutral and non-neutral markers. By screening populations on thou...

  4. Contact | Office of Cancer Genomics

    Science.gov (United States)

    For more information about the Office of Cancer Genomics, please contact: Office of Cancer Genomics National Cancer Institute 31 Center Drive, 10A07 Bethesda, Maryland 20892-2580 Phone: (301) 451-8027 Fax: (301) 480-4368 Email: ocg@mail.nih.gov *Please note that this site will not function properly in Internet Explorer unless you completely turn off the Compatibility View*

  5. Fungal genomics beyond Saccharomyces cerevisiae?

    DEFF Research Database (Denmark)

    Hofmann, Gerald; Mcintyre, Mhairi; Nielsen, Jens

    2003-01-01

    Fungi are used extensively in both fundamental research and industrial applications. Saccharomyces cerevisiae has been the model organism for fungal research for many years, particularly in functional genomics. However, considering the diversity within the fungal kingdom, it is obvious that the a......Fungi are used extensively in both fundamental research and industrial applications. Saccharomyces cerevisiae has been the model organism for fungal research for many years, particularly in functional genomics. However, considering the diversity within the fungal kingdom, it is obvious...

  6. EPIGENETIC MODIFICATIONS OF SWINE GENOME

    OpenAIRE

    Kristina Budimir; Gordana Kralik; Vladimir Margeta

    2013-01-01

    Epigenetics is represents a new way of genome analysis, respectively gene expression that occurs without DNA sequence change. Changes that occur are epigenetic modifications and they include post-translational histone modification and DNA methylation. Chemical groups that are added on DNA molecule cause changes in DNA and create epigenome. The consequence of that is appearance of imprinted genes in genome. Genetic imprinting is epigenetic modification in which one of inherited alleles inactiv...

  7. IS4 family goes genomic

    Directory of Open Access Journals (Sweden)

    Mahillon Jacques

    2008-01-01

    Full Text Available Abstract Background Insertion sequences (ISs are small, mobile DNA entities able to expand in prokaryotic genomes and trigger important rearrangements. To understand their role in evolution, accurate IS taxonomy is essential. The IS4 family is composed of ~70 elements and, like some other families, displays extremely elevated levels of internal divergence impeding its classification. The increasing availability of complete genome sequences provides a valuable source for the discovery of additional IS4 elements. In this study, this genomic database was used to update the structural and functional definition of the IS4 family. Results A total of 227 IS4-related sequences were collected among more than 500 sequenced bacterial and archaeal genomes, representing more than a three fold increase of the initial inventory. A clear division into seven coherent subgroups was discovered as well as three emerging families, which displayed distinct structural and functional properties. The IS4 family was sporadically present in 17 % of analyzed genomes, with most of them displaying single or a small number of IS4 elements. Significant expansions were detected only in some pathogens as well as among certain extremophiles, suggesting the probable involvement of some elements in bacterial and archaeal adaptation and/or evolution. Finally, it should be noted that some IS4 subgroups and two emerging families occurred preferentially in specific phyla or exclusively inside a specific genus. Conclusion The present taxonomic update of IS4 and emerging families will facilitate the classification of future elements as they arise from ongoing genome sequencing. Their narrow genomic impact and the existence of both IS-poor and IS-rich thriving prokaryotes suggested that these families, and probably ISs in general, are occasionally used as a tool for genome flexibility and evolution, rather than just representing self sustaining DNA entities.

  8. The fishes of Genome 10K

    KAUST Repository

    Bernardi, Giacomo

    2012-09-01

    The Genome 10K project aims to sequence the genomes of 10,000 vertebrates, representing approximately one genome for each vertebrate genus. Since fishes (cartilaginous fishes, ray-finned fishes and lobe-finned fishes) represent more than 50% of extant vertebrates, it is planned to target 4,000 fish genomes. At present, nearly 60 fish genomes are being sequenced at various public funded labs, and under a Genome 10K and BGI pilot project. An additional 100 fishes have been identified for sequencing in the next phase of Genome 10K project. © 2012 Elsevier B.V.

  9. Genomic medicine implementation: learning by example.

    Science.gov (United States)

    Williams, Marc S

    2014-03-01

    Genomic Medicine is beginning to emerge into clinical practice. The National Human Genome Research Institute's Genomic Medicine Working Group consists of organizations that have begun to implement some aspect of genomic medicine (e.g., family history, systematic implementation of Mendelian disease program, pharmacogenomics, whole exome/genome sequencing). This article concisely reviews the working group and provides a broader context for the articles in the special issue including an assessment of anticipated provider needs and ethical, legal, and social issues relevant to the implementation of genomic medicine. The challenges of implementation of innovation in clinical practice and the potential value of genomic medicine are discussed.

  10. Mutational dynamics of aroid chloroplast genomes.

    Science.gov (United States)

    Ahmed, Ibrar; Biggs, Patrick J; Matthews, Peter J; Collins, Lesley J; Hendy, Michael D; Lockhart, Peter J

    2012-01-01

    A characteristic feature of eukaryote and prokaryote genomes is the co-occurrence of nucleotide substitution and insertion/deletion (indel) mutations. Although similar observations have also been made for chloroplast DNA, genome-wide associations have not been reported. We determined the chloroplast genome sequences for two morphotypes of taro (Colocasia esculenta; family Araceae) and compared these with four publicly available aroid chloroplast genomes. Here, we report the extent of genome-wide association between direct and inverted repeats, indels, and substitutions in these aroid chloroplast genomes. We suggest that alternative but not mutually exclusive hypotheses explain the mutational dynamics of chloroplast genome evolution. PMID:23204304

  11. Genom-undersøgelser

    DEFF Research Database (Denmark)

    Mark, Edith

    2012-01-01

    Genom-undersøgelser bør anvendes varsomt, da de kan kompromittere den undersøgtes ret til ikke-viden, til selvbestemmelse og til privatliv. Myndighederne bør ikke forhindre borgere i at købe genom-undersøgelser hos private udbydere, uanset at testens sundhedsmæssige værdi kan være tvivlsom, men...... bør derudover sikre tilstrækkelig regulering • Såfremt genom-undersøgelser anvendes i forskning, bør forsøgspersoner ikke tilbydes tilbagemelding om fund af genetiske risikofaktorer • Såfremt genom-undersøgelser anvendes i diagnostik bør patienters ønsker om tilbagemelding af tilfældighedsfund aftales......, før undersøgelse igangsættes. Omfanget af tilbagemelding bør aftales i fællesskab mellem patient og læge • Genom-undersøgelser bør i både offentlig og privat regi være ledsaget af fyldestgørende og uvildig rådgivning og information • Information, rådgivning, henvisning og opfølgning på genom...

  12. Comparative genomic analyses in Asparagus.

    Science.gov (United States)

    Kuhl, Joseph C; Havey, Michael J; Martin, William J; Cheung, Foo; Yuan, Qiaoping; Landherr, Lena; Hu, Yi; Leebens-Mack, James; Town, Christopher D; Sink, Kenneth C

    2005-12-01

    Garden asparagus (Asparagus officinalis L.) belongs to the monocot family Asparagaceae in the order Asparagales. Onion (Allium cepa L.) and Asparagus officinalis are 2 of the most economically important plants of the core Asparagales, a well supported monophyletic group within the Asparagales. Coding regions in onion have lower GC contents than the grasses. We compared the GC content of 3374 unique expressed sequence tags (ESTs) from A. officinalis with Lycoris longituba and onion (both members of the core Asparagales), Acorus americanus (sister to all other monocots), the grasses, and Arabidopsis. Although ESTs in A. officinalis and Acorus had a higher average GC content than Arabidopsis, Lycoris, and onion, all were clearly lower than the grasses. The Asparagaceae have the smallest nuclear genomes among all plants in the core Asparagales, which typically have huge genomes. Within the Asparagaceae, European Asparagus species have approximately twice the nuclear DNA of that of southern African Asparagus species. We cloned and sequenced 20 genomic amplicons from European A. officinalis and the southern African species Asparagus plumosus and observed no clear evidence for a recent genome doubling in A. officinalis relative to A. plumosus. These results indicate that members of the genus Asparagus with smaller genomes may be useful genomic models for plants in the core Asparagales. PMID:16391674

  13. Comparative genomics of Helicobacter pylori

    Institute of Scientific and Technical Information of China (English)

    Quan-Jiang Dong; Qing Wang; Ying-Nin Xin; Ni Li; Shi-Ying Xuan

    2009-01-01

    Genomic sequences have been determined for a number of strains of Helicobacter pylori (H pylori) and related bacteria.With the development of microarray analysis and the wide use of subtractive hybridization techniques,comparative studies have been carried out with respect to the interstrain differences between H pylori and inter-species differences in the genome of related bacteria.It was found that the core genome of H pylori constitutes 1111 genes that are determinants of the species properties.A great pool of auxillary genes are mainly from the categories of cag pathogenicity islands,outer membrane proteins,restriction-modification system and hypothetical proteins of unknown function.Persistence of H pylori in the human stomach leads to the diversification of the genome.Comparative genomics suggest that a host jump has occurs from humans to felines.Candidate genes specific for the development of the gastric diseases were identified.With the aid of proteomics,population genetics and other molecular methods,future comparative genomic studies would dramatically promote our understanding of the evolution,pathogenesis and microbiology of H pylori.

  14. Genome size and genome evolution in diploid Triticeae species.

    Science.gov (United States)

    Eilam, T; Anikster, Y; Millet, E; Manisterski, J; Sagi-Assif, O; Feldman, M

    2007-11-01

    One of the intriguing issues concerning the dynamics of plant genomes is the occurrence of intraspecific variation in nuclear DNA amount. The aim of this work was to assess the ranges of intraspecific, interspecific, and intergeneric variation in nuclear DNA content of diploid species of the tribe Triticeae (Poaceae) and to examine the relation between life form or habitat and genome size. Altogether, 438 plants representing 272 lines that belong to 22 species were analyzed. Nuclear DNA content was estimated by flow cytometry. Very small intraspecific variation in DNA amount was found between lines of Triticeae diploid species collected from different habitats or between different morphs. In contrast to the constancy in nuclear DNA amount at the intraspecific level, there are significant differences in genome size between the various diploid species. Within the genus Aegilops, the 1C DNA amount ranged from 4.84 pg in A. caudata to 7.52 pg in A. sharonensis; among genera, the 1C DNA amount ranged from 4.18 pg in Heteranthelium piliferum to 9.45 pg in Secale montanum. No evidence was found for a smaller genome size in annual, self-pollinating species relative to perennial, cross-pollinating ones. Diploids that grow in the southern part of the group's distribution have larger genomes than those growing in other parts of the distribution. The contrast between the low variation at the intraspecific level and the high variation at the interspecific one suggests that changes in genome size originated in close temporal proximity to the speciation event, i.e., before, during, or immediately after it. The possible effects of sudden changes in genome size on speciation processes are discussed.

  15. The UCSC Genome Browser database: 2016 update

    OpenAIRE

    Speir, Matthew L; Zweig, Ann S.; Rosenbloom, Kate R.; Raney, Brian J.; Paten, Benedict; Nejad, Parisa; Rowe, Laurence D.; Learned, Katrina; Karolchik, Donna; Hinrichs, Angie S.; Heitner, Steve; Harte, Rachel A.; Haeussler, Maximilian; Guruvadoo, Luvina; Fujita, Pauline A.

    2015-01-01

    For the past 15 years, the UCSC Genome Browser (http://genome.ucsc.edu/) has served the international research community by offering an integrated platform for viewing and analyzing information from a large database of genome assemblies and their associated annotations. The UCSC Genome Browser has been under continuous development since its inception with new data sets and software features added frequently. Some release highlights of this year include new and updated genome browsers for vari...

  16. A Genome-Wide Perspective on Metabolism

    DEFF Research Database (Denmark)

    Rauch, Alexander; Mandrup, Susanne

    2015-01-01

    number of technologies that can be used to obtain genome-wide insight into how genomes are reprogrammed during development and in response to specific external signals. By applying such technologies, we have begun to reveal the cross-talk between metabolism and the genome, i.e., how genomes...... are reprogrammed in response to metabolites, and how the regulation of metabolic networks is coordinated at the genomic level....

  17. REEF: searching REgionally Enriched Features in genomes

    OpenAIRE

    Danieli Gian Antonio; Coppe Alessandro; Bortoluzzi Stefania

    2006-01-01

    Abstract Background In Eukaryotic genomes, different features including genes are not uniformly distributed. The integration of annotation information and genomic position of functional DNA elements in the Eukaryotic genomes opened the way to test novel hypotheses of higher order genome organization and regulation of expression. Results REEF is a new tool, aimed at identifying genomic regions enriched in specific features, such as a class or group of genes homogeneous for expression and/or fu...

  18. Brazil: public health genomics.

    Science.gov (United States)

    Castilla, E E; Luquetti, D V

    2009-01-01

    Brazil represents half of South America and one third of Latin America, having more than 186 million inhabitants. After China and India it is the third largest developing country in the world. The wealth is unequally distributed among the states and among the people. Brazil has a large and complex health care system. A Universal Public Health System (SUS: Sistema SPACEnico de Saúde) covers the medical expenses for 80% of the population. The genetic structure of the population is very complex, including a large proportion of tri- hybrid persons, genetic isolates, and a panmictic large majority. Genetic services are offered at 64 genetic centers, half of them public and free. Nationwide networks are operating for inborn errors of metabolism, oncogenetics, and craniofacial anomalies. The Brazilian Society of Medical Genetics (SBGM) has granted 120 board certifications since 1986, and 7 recognized residences in medical genetics are operating in the country. Three main public health actions promoted by the federal government have been undertaken in the last decade, ultimately aimed at the prevention of birth defects. Since 1999, birth defects are reported for all 3 million annual live births, several vaccination strategies aim at the eradication of rubella, and wheat and maize flours are fortified with folic acid. Currently, the government distributes over 2 million US dollars to finance 14 research projects aimed at providing the basis for the adequate prevention and care of genetics disorders through the SUS. Continuity of this proactive attitude of the government in the area of genomics in public health is desired. PMID:19023184

  19. Genomics and museum specimens.

    Science.gov (United States)

    Nachman, Michael W

    2013-12-01

    Nearly 25 years ago, Allan Wilson and colleagues isolated DNA sequences from museum specimens of kangaroo rats (Dipodomys panamintinus) and compared these sequences with those from freshly collected animals (Thomas et al. 1990). The museum specimens had been collected up to 78 years earlier, so the two samples provided a direct temporal comparison of patterns of genetic variation. This was not the first time DNA sequences had been isolated from preserved material, but it was the first time it had been carried out with a population sample. Population geneticists often try to make inferences about the influence of historical processes such as selection, drift, mutation and migration on patterns of genetic variation in the present. The work of Wilson and colleagues was important in part because it suggested a way in which population geneticists could actually study genetic change in natural populations through time, much the same way that experimentalists can do with artificial populations in the laboratory. Indeed, the work of Thomas et al. (1990) spawned dozens of studies in which museum specimens were used to compare historical and present-day genetic diversity (reviewed in Wandeler et al. 2007). All of these studies, however, were limited by the same fundamental problem: old DNA is degraded into short fragments. As a consequence, these studies mostly involved PCR amplification of short templates, usually short stretches of mitochondrial DNA or microsatellites. In this issue, Bi et al. (2013) report a breakthrough that should open the door to studies of genomic variation in museum specimens. They used target enrichment (exon capture) and next-generation (Illumina) sequencing to compare patterns of genetic variation in historic and present-day population samples of alpine chipmunks (Tamias alpinus) (Fig. 1). The historic samples came from specimens collected in 1915, so the temporal span of this comparison is nearly 100 years.

  20. 中华鳖弗氏柠檬酸杆菌的分离、鉴定及药物敏感性试验%Isolation, Identification and Antibiotic Sensitivity of Pathogenic Bacterium Citrobacter freundii from Soft Shell Turtle Trionyx sinensis

    Institute of Scientific and Technical Information of China (English)

    田飞焱; 欧阳敏; 张晓燕; 江明华

    2013-01-01

    从患病中华鳖(Trionyx sinensis)内脏中分离到一株细菌(LCJY-002).ATB Expression型微生物鉴定系统显示:该菌为弗氏柠檬酸杆菌(Citrobacter freundii.16S rDNA分析得到1条长度为1456bp的核苷酸序列(GenBank登录号为KC691177);Blast分析显示:该分离株与弗氏柠檬酸杆菌的同源性达99%,在系统发育树上与C.freundii聚为一支.鉴定结果确认:菌株LCJY-002为弗氏柠檬酸杆菌.人工回归感染试验证实:该菌具有致病性,PCR检测表明:分离的弗氏柠檬酸杆菌具有cfa毒力因子.药敏试验结果显示:该菌对16种抗菌药物中的庆大霉素等7种药物敏感.

  1. 来源于柠檬酸杆菌的高比活植酸酶基因在毕赤酵母中的高效表达%Overexpression of Citrobacter braakii phytase with high specific activity in Pichia pastoris

    Institute of Scientific and Technical Information of China (English)

    黄火清; 罗会颖; 柏映国; 王亚茹; 姚斌; 孟昆; 袁铁铮; 杨培龙

    2006-01-01

    柠檬酸杆菌(Citrobacter braakii)来源的植酸酶是目前报道的比活最高的植酸酶.按照毕赤酵母(Pichia pastoris)对密码子的选择偏向性,对来源于柠檬酸杆菌的高比活植酸酶基因AppA 进行了密码子优化改造.改造后的基因AppA(m)按正确的阅读框架融合到毕赤酵母表达载体pPIC9的α-因子信号肽编码序列3′端,通过电击转化得到重组转化子.通过PCR验证,AppA(m)已整合在酵母染色体上.SDS-PAGE分析和表达产物的研究表明,植酸酶得到了高效分泌表达,在5L发酵罐中植酸酶蛋白表达量达到3.2mg/mL发酵液,发酵效价达到每毫升发酵液1.4×107IU以上,高于目前报道的各种植酸酶基因工程菌株的发酵效价.

  2. Differential expression of immune-related genes from skin of zebrafish induced by the infection of Citrobacter freundii%弗氏柠檬酸杆菌感染诱导斑马鱼皮肤免疫相关基因的差异表达

    Institute of Scientific and Technical Information of China (English)

    吕爱军; 胡秀彩; 朱静榕; 薛军; 王艺; 程超

    2012-01-01

    With water pollution aggravated and intensive aquaculture spread, the occurrence of opportunistic infections has become a significant health problem in farmed fish, Citrobacter freundii is an enterobacterium commonly isolated from diseased and healthy animals, including human, mammals and fish, which is considered to be an opportunistic pathogen. Skin is an essential protective barrier for fish and functions as a first line of defense against invading pathogens,but its molecular mechanism remains unclear. The objective of this study is to screen the differential gene expression in response to pathogen infection in skin of fish,and provide a basis for understanding the fish skin immune mechanism to the pathogen at the molecular level. Here,a strain of bacteria was isolated from intestine in Ctenopharyngodon idellus, which was identified by using the morphological observation, physiological and biochemical characteristics, and 16S rDNA sequence analysis. The results showed that the isolated strain was identified species levels as Citrobacter freundii ,and animal tests showed that the strain was lethal to zebrafish. Immune response in skin of fish analyzed by using Citrobacter freundii induced zebrafish as a model, which applied the Affymetrix zebrafish cDNA microarray hybridized to the skin tissues. Total RNAs were isolated from the skin tissues of the zebrafish and labeled with biotin,and hybridized to zebrafish cDNA gene chips. The expression profiles from the hybridization to 15617 genes in zebrafish cDNA array were analyzed by the GeneChip Operating Software( GCOS 1.4). Out of 15617 genes in zebrafish cDNA chips,total of 88 immune-related genes were identified to be significantly expressed in the skin tissues,of which 74 genes are up-regulated and 14 are down-regulated in the zebrafish skin tissues. Furthermore, the differential expression genes could be categorized into eight functional groups by using the Gene Ontology (GO) method,including complement

  3. The Genomic Code: Genome Evolution and Potential Applications

    KAUST Repository

    Bernardi, Giorgio

    2016-01-25

    The genome of metazoans is organized according to a genomic code which comprises three laws: 1) Compositional correlations hold between contiguous coding and non-coding sequences, as well as among the three codon positions of protein-coding genes; these correlations are the consequence of the fact that the genomes under consideration consist of fairly homogeneous, long (≥200Kb) sequences, the isochores; 2) Although isochores are defined on the basis of purely compositional properties, GC levels of isochores are correlated with all tested structural and functional properties of the genome; 3) GC levels of isochores are correlated with chromosome architecture from interphase to metaphase; in the case of interphase the correlation concerns isochores and the three-dimensional “topological associated domains” (TADs); in the case of mitotic chromosomes, the correlation concerns isochores and chromosomal bands. Finally, the genomic code is the fourth and last pillar of molecular biology, the first three pillars being 1) the double helix structure of DNA; 2) the regulation of gene expression in prokaryotes; and 3) the genetic code.

  4. Mapping whole genome shotgun sequence and variant calling in mammalian species without their reference genomes

    Science.gov (United States)

    Genomics research in mammals has produced reference genome sequences that are essential for identifying variation associated with disease. High quality reference genome sequences are now available for humans, model species, and economically important agricultural animals. Comparisons between these s...

  5. Human Genome Education Program

    Energy Technology Data Exchange (ETDEWEB)

    Richard Myers; Lane Conn

    2000-05-01

    The funds from the DOE Human Genome Program, for the project period 2/1/96 through 1/31/98, have provided major support for the curriculum development and field testing efforts for two high school level instructional units: Unit 1, ''Exploring Genetic Conditions: Genes, Culture and Choices''; and Unit 2, ''DNA Snapshots: Peaking at Your DNA''. In the original proposal, they requested DOE support for the partial salary and benefits of a Field Test Coordinator position to: (1) complete the field testing and revision of two high school curriculum units, and (2) initiate the education of teachers using these units. During the project period of this two-year DOE grant, a part-time Field-Test Coordinator was hired (Ms. Geraldine Horsma) and significant progress has been made in both of the original proposal objectives. Field testing for Unit 1 has occurred in over 12 schools (local and non-local sites with diverse student populations). Field testing for Unit 2 has occurred in over 15 schools (local and non-local sites) and will continue in 12-15 schools during the 96-97 school year. For both curricula, field-test sites and site teachers were selected for their interest in genetics education and in hands-on science education. Many of the site teachers had no previous experience with HGEP or the unit under development. Both of these first-year biology curriculum units, which contain genetics, biotechnology, societal, ethical and cultural issues related to HGP, are being implemented in many local and non-local schools (SF Bay Area, Southern California, Nebraska, Hawaii, and Texas) and in programs for teachers. These units will reach over 10,000 students in the SF Bay Area and continues to receive support from local corporate and private philanthropic organizations. Although HGEP unit development is nearing completion for both units, data is still being gathered and analyzed on unit effectiveness and student learning. The final field

  6. Advances in Genome Biology & Technology

    Energy Technology Data Exchange (ETDEWEB)

    Thomas J. Albert, Jon R. Armstrong, Raymond K. Auerback, W. Brad Barbazuk, et al.

    2007-12-01

    This year's meeting focused on the latest advances in new DNA sequencing technologies and the applications of genomics to disease areas in biology and biomedicine. Daytime plenary sessions highlighted cutting-edge research in areas such as complex genetic diseases, comparative genomics, medical sequencing, massively parallel DNA sequencing, and synthetic biology. Technical approaches being developed and utilized in contemporary genomics research were presented during evening concurrent sessions. Also, as in previous years, poster sessions bridged the morning and afternoon plenary sessions. In addition, for the third year in a row, the Advances in Genome Biology and Technology (AGBT) meeting was preceded by a pre-meeting workshop that aimed to provide an introductory overview for trainees and other meeting attendees. This year, speakers at the workshop focused on next-generation sequencing technologies, including their experiences, findings, and helpful advise for others contemplating using these platforms in their research. Speakers from genome centers and core sequencing facilities were featured and the workshop ended with a roundtable discussion, during which speakers fielded questions from the audience.

  7. NCBI prokaryotic genome annotation pipeline.

    Science.gov (United States)

    Tatusova, Tatiana; DiCuccio, Michael; Badretdin, Azat; Chetvernin, Vyacheslav; Nawrocki, Eric P; Zaslavsky, Leonid; Lomsadze, Alexandre; Pruitt, Kim D; Borodovsky, Mark; Ostell, James

    2016-08-19

    Recent technological advances have opened unprecedented opportunities for large-scale sequencing and analysis of populations of pathogenic species in disease outbreaks, as well as for large-scale diversity studies aimed at expanding our knowledge across the whole domain of prokaryotes. To meet the challenge of timely interpretation of structure, function and meaning of this vast genetic information, a comprehensive approach to automatic genome annotation is critically needed. In collaboration with Georgia Tech, NCBI has developed a new approach to genome annotation that combines alignment based methods with methods of predicting protein-coding and RNA genes and other functional elements directly from sequence. A new gene finding tool, GeneMarkS+, uses the combined evidence of protein and RNA placement by homology as an initial map of annotation to generate and modify ab initio gene predictions across the whole genome. Thus, the new NCBI's Prokaryotic Genome Annotation Pipeline (PGAP) relies more on sequence similarity when confident comparative data are available, while it relies more on statistical predictions in the absence of external evidence. The pipeline provides a framework for generation and analysis of annotation on the full breadth of prokaryotic taxonomy. For additional information on PGAP see https://www.ncbi.nlm.nih.gov/genome/annotation_prok/ and the NCBI Handbook, https://www.ncbi.nlm.nih.gov/books/NBK174280/. PMID:27342282

  8. The genome of Prunus mume

    Science.gov (United States)

    Zhang, Qixiang; Chen, Wenbin; Sun, Lidan; Zhao, Fangying; Huang, Bangqing; Yang, Weiru; Tao, Ye; Wang, Jia; Yuan, Zhiqiong; Fan, Guangyi; Xing, Zhen; Han, Changlei; Pan, Huitang; Zhong, Xiao; Shi, Wenfang; Liang, Xinming; Du, Dongliang; Sun, Fengming; Xu, Zongda; Hao, Ruijie; Lv, Tian; Lv, Yingmin; Zheng, Zequn; Sun, Ming; Luo, Le; Cai, Ming; Gao, Yike; Wang, Junyi; Yin, Ye; Xu, Xun; Cheng, Tangren; Wang, Jun

    2012-01-01

    Prunus mume (mei), which was domesticated in China more than 3,000 years ago as ornamental plant and fruit, is one of the first genomes among Prunus subfamilies of Rosaceae been sequenced. Here, we assemble a 280M genome by combining 101-fold next-generation sequencing and optical mapping data. We further anchor 83.9% of scaffolds to eight chromosomes with genetic map constructed by restriction-site-associated DNA sequencing. Combining P. mume genome with available data, we succeed in reconstructing nine ancestral chromosomes of Rosaceae family, as well as depicting chromosome fusion, fission and duplication history in three major subfamilies. We sequence the transcriptome of various tissues and perform genome-wide analysis to reveal the characteristics of P. mume, including its regulation of early blooming in endodormancy, immune response against bacterial infection and biosynthesis of flower scent. The P. mume genome sequence adds to our understanding of Rosaceae evolution and provides important data for improvement of fruit trees. PMID:23271652

  9. NCBI prokaryotic genome annotation pipeline.

    Science.gov (United States)

    Tatusova, Tatiana; DiCuccio, Michael; Badretdin, Azat; Chetvernin, Vyacheslav; Nawrocki, Eric P; Zaslavsky, Leonid; Lomsadze, Alexandre; Pruitt, Kim D; Borodovsky, Mark; Ostell, James

    2016-08-19

    Recent technological advances have opened unprecedented opportunities for large-scale sequencing and analysis of populations of pathogenic species in disease outbreaks, as well as for large-scale diversity studies aimed at expanding our knowledge across the whole domain of prokaryotes. To meet the challenge of timely interpretation of structure, function and meaning of this vast genetic information, a comprehensive approach to automatic genome annotation is critically needed. In collaboration with Georgia Tech, NCBI has developed a new approach to genome annotation that combines alignment based methods with methods of predicting protein-coding and RNA genes and other functional elements directly from sequence. A new gene finding tool, GeneMarkS+, uses the combined evidence of protein and RNA placement by homology as an initial map of annotation to generate and modify ab initio gene predictions across the whole genome. Thus, the new NCBI's Prokaryotic Genome Annotation Pipeline (PGAP) relies more on sequence similarity when confident comparative data are available, while it relies more on statistical predictions in the absence of external evidence. The pipeline provides a framework for generation and analysis of annotation on the full breadth of prokaryotic taxonomy. For additional information on PGAP see https://www.ncbi.nlm.nih.gov/genome/annotation_prok/ and the NCBI Handbook, https://www.ncbi.nlm.nih.gov/books/NBK174280/.

  10. Pseudomonas genomes: diverse and adaptable.

    Science.gov (United States)

    Silby, Mark W; Winstanley, Craig; Godfrey, Scott A C; Levy, Stuart B; Jackson, Robert W

    2011-07-01

    Members of the genus Pseudomonas inhabit a wide variety of environments, which is reflected in their versatile metabolic capacity and broad potential for adaptation to fluctuating environmental conditions. Here, we examine and compare the genomes of a range of Pseudomonas spp. encompassing plant, insect and human pathogens, and environmental saprophytes. In addition to a large number of allelic differences of common genes that confer regulatory and metabolic flexibility, genome analysis suggests that many other factors contribute to the diversity and adaptability of Pseudomonas spp. Horizontal gene transfer has impacted the capability of pathogenic Pseudomonas spp. in terms of disease severity (Pseudomonas aeruginosa) and specificity (Pseudomonas syringae). Genome rearrangements likely contribute to adaptation, and a considerable complement of unique genes undoubtedly contributes to strain- and species-specific activities by as yet unknown mechanisms. Because of the lack of conserved phenotypic differences, the classification of the genus has long been contentious. DNA hybridization and genome-based analyses show close relationships among members of P. aeruginosa, but that isolates within the Pseudomonas fluorescens and P. syringae species are less closely related and may constitute different species. Collectively, genome sequences of Pseudomonas spp. have provided insights into pathogenesis and the genetic basis for diversity and adaptation.

  11. Development of fatal intestinal inflammation in MyD88 deficient mice co-infected with helminth and bacterial enteropathogens.

    Directory of Open Access Journals (Sweden)

    Libo Su

    2014-07-01

    Full Text Available Infections with intestinal helminth and bacterial pathogens, such as enteropathogenic Escherichia coli, continue to be a major global health threat for children. To determine whether and how an intestinal helminth parasite, Heligomosomoides polygyrus, might impact the TLR signaling pathway during the response to a bacterial enteropathogen, MyD88 knockout and wild-type C57BL/6 mice were infected with H. polygyrus, the bacterial enteropathogen Citrobacter rodentium, or both. We found that MyD88 knockout mice co-infected with H. polygyrus and C. rodentium developed more severe intestinal inflammation and elevated mortality compared to the wild-type mice. The enhanced susceptibility to C. rodentium, intestinal injury and mortality of the co-infected MyD88 knockout mice were found to be associated with markedly reduced intestinal phagocyte recruitment, decreased expression of the chemoattractant KC, and a significant increase in bacterial translocation. Moreover, the increase in bacterial infection and disease severity were found to be correlated with a significant downregulation of antimicrobial peptide expression in the intestinal tissue in co-infected MyD88 knockout mice. Our results suggest that the MyD88 signaling pathway plays a critical role for host defense and survival during helminth and enteric bacterial co-infection.

  12. Constitutive induction of intestinal Tc17 cells in the absence of hematopoietic cell-specific MHC class II expression.

    Science.gov (United States)

    Rubino, Stephen J; Geddes, Kaoru; Magalhaes, Joao G; Streutker, Catherine; Philpott, Dana J; Girardin, Stephen E

    2013-11-01

    The enteric pathogen Citrobacter rodentium induces a mucosal IL-17 response in CD4(+) T helper (Th17) cells that is dependent on the Nod-like receptors Nod1 and Nod2. Here, we sought to determine whether this early Th17 response required antigen presentation by major histocompatibility complex class II (MHCII) for full induction. At early phases of C. rodentium infection, we observed that the intestinal mucosal Th17 response was fully blunted in irradiated mice reconstituted with MHCII-deficient (MHCII(-/-) →WT) hematopoietic cells. Surprisingly, we also observed a substantial increase in the relative frequency of IL-17(+) CD8(+) CD4(-) TCR-β(+) cells (Tc17 cells) and FOXP3(+) CD8(+) CD4(-) TCR-β(+) cells in the lamina propria and intraepithelial lymphocyte compartment of MHCII(-/-) →WT mice compared with that in WT→WT counterparts. Moreover, MHCII(-/-) →WT mice displayed increased susceptibility, increased bacterial translocation to deeper organs, and more severe colonic histopathology after infection with C. rodentium. Finally, a similar phenotype was observed in mice deficient for CIITA, a transcriptional regulator of MHCII expression. Together, these results indicate that MHCII is required to mount early mucosal Th17 responses to an enteric pathogen, and that MHCII regulates the induction of atypical CD8(+) T-cell subsets, such as Tc17 cells and FOXP3(+) CD8(+) cells, in vivo. PMID:23881368

  13. A physical map of the human genome

    Energy Technology Data Exchange (ETDEWEB)

    McPherson, J.D.; Marra, M.; Hillier, L.; Waterston, R.H.; Chinwalla, A.; Wallis, J.; Sekhon, M.; Wylie, K.; Mardis, E.R.; Wilson, R.K.; Fulton, R.; Kucaba, T.A.; Wagner-McPherson, C.; Barbazuk, W.B.; Gregory, S.G.; Humphray, S.J.; French, L.; Evans, R.S.; Bethel, G.; Whittaker, A.; Holden, J.L.; McCann, O.T.; Dunham, A.; Soderlund, C.; Scott, C.E.; Bentley, D.R.; Schuler, G.; Chen, H.-C.; Jang, W.; Green, E.D.; Idol, J.R.; Maduro, V.V. Braden; Montgomery, K.T.; Lee, E.; Miller, A.; Emerling, S.; Kucherlapati; Gibbs, R.; Scherer, S.; Gorrell, J.H.; Sodergren, E.; Clerc-Blankenburg, K.; Tabor, P.; Naylor, S.; Garcia, D.; de Jong, P.J.; Catanese, J.J.; Nowak, N.; Osoegawa, K.; Qin, S.; Rowen, L.; Madan, A.; Dors, M.; Hood, L.; Trask, B.; Friedman, C.; Massa, H.; Cheung, V.G.; Kirsch, I.R.; Reid, T.; Yonescu, R.; Weissenbach, J.; Bruls, T.; Heilig, R.; Branscomb, E.; Olsen, A.; Doggett, N.; Cheng, J.F.; Hawkins, T.; Myers, R.M.; Shang, J.; Ramirez, L.; Schmutz, J.; Velasquez, O.; Dixon, K.; Stone, N.E.; Cox, D.R.; Haussler, D.; Kent, W.J.; Furey, T.; Rogic, S.; Kennedy, S.; Jones, S.; Rosenthal, A.; Wen, G.; Schilhabel, M.; Gloeckner, G.; Nyakatura, G.; Siebert, R.; Schlegelberger, B.; Korenberg, J.; Chen, X.N.; Fujiyama, A.; Hattori, M.; Toyoda, A.; Yada, T.; Park, H.S.; Sakaki, Y.; Shimizu, N.; Asakawa, S.; Kawasaki, K.; Sasaki, T.; Shintani, A.; Shimizu, A.; Shibuya, K.; Kudoh, J.; Minoshima, S.; Ramser, J.; Seranski, P.; Hoff, C.; Poustka, A.; Reinhardt, R.; Lehrach, H.

    2001-01-01

    The human genome is by far the largest genome to be sequenced, and its size and complexity present many challenges for sequence assembly. The International Human Genome Sequencing Consortium constructed a map of the whole genome to enable the selection of clones for sequencing and for the accurate assembly of the genome sequence. Here we report the construction of the whole-genome bacterial artificial chromosome (BAC) map and its integration with previous landmark maps and information from mapping efforts focused on specific chromosomal regions. We also describe the integration of sequence data with the map.

  14. : a database of ciliate genome rearrangements.

    Science.gov (United States)

    Burns, Jonathan; Kukushkin, Denys; Lindblad, Kelsi; Chen, Xiao; Jonoska, Nataša; Landweber, Laura F

    2016-01-01

    Ciliated protists exhibit nuclear dimorphism through the presence of somatic macronuclei (MAC) and germline micronuclei (MIC). In some ciliates, DNA from precursor segments in the MIC genome rearranges to form transcriptionally active genes in the mature MAC genome, making these ciliates model organisms to study the process of somatic genome rearrangement. Similar broad scale, somatic rearrangement events occur in many eukaryotic cells and tumors. The (http://oxytricha.princeton.edu/mds_ies_db) is a database of genome recombination and rearrangement annotations, and it provides tools for visualization and comparative analysis of precursor and product genomes. The database currently contains annotations for two completely sequenced ciliate genomes: Oxytricha trifallax and Tetrahymena thermophila.

  15. How good is our genome?

    Science.gov (United States)

    Weill, Jean-Claude; Radman, Miroslav

    2004-01-29

    Our genome has evolved to perpetuate itself through the maintenance of the species via an uninterrupted chain of reproductive somas. Accordingly, evolution is not concerned with diseases occurring after the soma's reproductive stage. Following Richard Dawkins, we would like to reassert that we indeed live as disposable somas, slaves of our germline genome, but could soon start rebelling against such slavery. Cancer and its relation to the TP53 gene may offer a paradigmatic example. The observation that the latency period in cancer can be prolonged in mice by increasing the number of TP53 genes in their genome, suggests that sooner or later we will have to address the question of heritable disease avoidance via the manipulation of the human germline. PMID:15065661

  16. Genomics of Escherichia and Shigella

    Science.gov (United States)

    Perna, Nicole T.

    The laboratory workhorse Escherichia coli K-12 is among the most intensively studied living organisms on earth, and this single strain serves as the model system behind much of our understanding of prokaryotic molecular biology. Dense genome sequencing and recent insightful comparative analyses are making the species E. coli, as a whole, an emerging system for studying prokaryotic population genetics and the relationship between system-scale, or genome-scale, molecular evolution and complex traits like host range and pathogenic potential. Genomic perspective has revealed a coherent but dynamic species united by intraspecific gene flow via homologous lateral or horizontal transfer and differentiated by content flux mediated by acquisition of DNA segments from interspecies transfers.

  17. Crenarchaeal Viruses: Morphotypes and Genomes,

    DEFF Research Database (Denmark)

    Prangishvili, P.; Basta, P.; Garrett, Roger Antony

    2008-01-01

    not been observed among viruses from the other two domains of life, the Bacteria and the Eukarya. Also the sequences of circular and linear genomes of crenarchaeal viruses are remarkable because the vast majority of predicted genes have no homologs in the public sequence databases. Viruses...... of the Crenarchaeota generally do not cause the lysis of the host cells during release of viral progeny and they persist in infected cells in stable carrier state. In accordance with this rather unsophisticated virus-host relationship, the studies of transcription of genes in rudiviruses and fusellovirus SSV1...... demonstrated a simple transcriptional pattern with minimal temporal control. The replication of viral genomes has not been studied experimentally. Nevertheless, some plausible predictions about possible replication strategies could be made based on specific features of several viral genomes. The comparative...

  18. Enhancer Identification through Comparative Genomics

    Energy Technology Data Exchange (ETDEWEB)

    Visel, Axel; Bristow, James; Pennacchio, Len A.

    2006-10-01

    With the availability of genomic sequence from numerousvertebrates, a paradigm shift has occurred in the identification ofdistant-acting gene regulatory elements. In contrast to traditionalgene-centric studies in which investigators randomly scanned genomicfragments that flank genes of interest in functional assays, the modernapproach begins electronically with publicly available comparativesequence datasets that provide investigators with prioritized lists ofputative functional sequences based on their evolutionary conservation.However, although a large number of tools and resources are nowavailable, application of comparative genomic approaches remains far fromtrivial. In particular, it requires users to dynamically consider thespecies and methods for comparison depending on the specific biologicalquestion under investigation. While there is currently no single generalrule to this end, it is clear that when applied appropriately,comparative genomic approaches exponentially increase our power ingenerating biological hypotheses for subsequent experimentaltesting.

  19. Translating genomics in cancer care.

    Science.gov (United States)

    Bombard, Yvonne; Bach, Peter B; Offit, Kenneth

    2013-11-01

    There is increasing enthusiasm for genomics and its promise in advancing personalized medicine. Genomic information has been used to personalize health care for decades, spanning the fields of cardiovascular disease, infectious disease, endocrinology, metabolic medicine, and hematology. However, oncology has often been the first test bed for the clinical translation of genomics for diagnostic, prognostic, and therapeutic applications. Notable hereditary cancer examples include testing for mutations in BRCA1 or BRCA2 in unaffected women to identify those at significantly elevated risk for developing breast and ovarian cancers, and screening patients with newly diagnosed colorectal cancer for mutations in 4 mismatch repair genes to reduce morbidity and mortality in their relatives. Somatic genomic testing is also increasingly used in oncology, with gene expression profiling of breast tumors and EGFR testing to predict treatment response representing commonly used examples. Health technology assessment provides a rigorous means to inform clinical and policy decision-making through systematic assessment of the evidentiary base, along with precepts of clinical effectiveness, cost-effectiveness, and consideration of risks and benefits for health care delivery and society. Although this evaluation is a fundamental step in the translation of any new therapeutic, procedure, or diagnostic test into clinical care, emerging developments may threaten this standard. These include "direct to consumer" genomic risk assessment services and the challenges posed by incidental results generated from next-generation sequencing (NGS) technologies. This article presents a review of the evidentiary standards and knowledge base supporting the translation of key cancer genomic technologies along the continuum of validity, utility, cost-effectiveness, health service impacts, and ethical and societal issues, and offers future research considerations to guide the responsible introduction of

  20. How retrotransposons shape genome regulation.

    Science.gov (United States)

    Mita, Paolo; Boeke, Jef D

    2016-04-01

    Retrotransposons are mutagenic units able to move within the genome. Despite many defenses deployed by the host to suppress potentially harmful activities of retrotransposons, these genetic units have found ways to meld with normal cellular functions through processes of exaptation and domestication. The same host mechanisms targeting transposon mobility allow for expansion and rewiring of gene regulatory networks on an evolutionary time scale. Recent works demonstrating retrotransposon activity during development, cell differentiation and neurogenesis shed new light on unexpected activities of transposable elements. Moreover, new technological advances illuminated subtler nuances of the complex relationship between retrotransposons and the host genome, clarifying the role of retroelements in evolution, development and impact on human disease.

  1. Biocommunication and natural genome editing

    Institute of Scientific and Technical Information of China (English)

    Guenther; Witzany

    2010-01-01

    The biocommunicative approach investigates communication processes within and among cells,tissues,organs and organisms as sign-mediated interactions,and nucleotide sequences as code,i.e.language-like text,which follows in parallel three kinds of rules:combinatorial (syntactic),context-sensitive(pragmatic),and contentspecific(semantic).Natural genome editing from a bio-communicative perspective is competent agent-driven generation and integration of meaningful nucleotide sequences into pre-existing genomic content arrangements and the ability to(re-)combine and(re-)regulate them according to context-dependent(i.e.adaptational) purposes of the host organism.

  2. EPIGENETIC MODIFICATIONS OF SWINE GENOME

    Directory of Open Access Journals (Sweden)

    Kristina Budimir

    2013-06-01

    Full Text Available Epigenetics is represents a new way of genome analysis, respectively gene expression that occurs without DNA sequence change. Changes that occur are epigenetic modifications and they include post-translational histone modification and DNA methylation. Chemical groups that are added on DNA molecule cause changes in DNA and create epigenome. The consequence of that is appearance of imprinted genes in genome. Genetic imprinting is epigenetic modification in which one of inherited alleles inactivates. Its influence can be seen on productive and reproductive traits. Discovering new imprinted genes is important because of their conservation and understanding their function.

  3. Genome editing comes of age.

    Science.gov (United States)

    Kim, Jin-Soo

    2016-09-01

    Genome editing harnesses programmable nucleases to cut and paste genetic information in a targeted manner in living cells and organisms. Here, I review the development of programmable nucleases, including zinc finger nucleases (ZFNs), TAL (transcription-activator-like) effector nucleases (TALENs) and CRISPR (cluster of regularly interspaced palindromic repeats)-Cas9 (CRISPR-associated protein 9) RNA-guided endonucleases (RGENs). I specifically highlight the key advances that set the foundation for the rapid and widespread implementation of CRISPR-Cas9 genome editing approaches that has revolutionized the field. PMID:27490630

  4. Genomic profiling of breast cancer.

    Science.gov (United States)

    Pandey, Anjita; Singh, Alok Kumar; Maurya, Sanjeev Kumar; Rai, Rajani; Tewari, Mallika; Kumar, Mohan; Shukla, Hari S

    2009-05-01

    Genome study provides significant changes in the advancement of molecular diagnosis and treatment in Breast cancer. Several recent critical advances and high-throughput techniques identified the genomic trouble and dramatically accelerated the pace of research in preventing and curing this malignancy. Tumor-suppressor genes, proto-oncogenes, DNA-repair genes, carcinogen-metabolism genes are critically involved in progression of breast cancer. We reviewed imperative finding in breast genetics, ongoing work to segregate further susceptible genes, and preliminary studies on molecular profiling.

  5. Genomic Signals of Reoriented ORFs

    Directory of Open Access Journals (Sweden)

    Paul Dan Cristea

    2004-01-01

    Full Text Available Complex representation of nucleotides is used to convert DNA sequences into complex digital genomic signals. The analysis of the cumulated phase and unwrapped phase of DNA genomic signals reveals large-scale features of eukaryote and prokaryote chromosomes that result from statistical regularities of base and base-pair distributions along DNA strands. By reorienting the chromosome coding regions, a “hidden” linear variation of the cumulated phase has been revealed, along with the conspicuous almost linear variation of the unwrapped phase. A model of chromosome longitudinal structure is inferred on these bases.

  6. Genomic and non-genomic actions of glucocorticoids in asthma

    Directory of Open Access Journals (Sweden)

    Alangari Abdullah

    2010-01-01

    Full Text Available Glucocorticoids are the mainstay of asthma therapy. They are primarily used to suppress airway inflammation, which is the central pathological change in asthmatic patients′ airways. This is achieved by many different mechanisms. The classical mechanism is by suppression of the genetic transcription of many inflammatory cytokines that are key in asthma pathophysiology (transrepression. On the other hand, the transcription of certain inhibitory cytokines is activated by glucocorticoids (transactivation, a mechanism that also mediates many of the adverse effects of glucocorticoids. The onset of action through these mechanisms is often delayed (4-24 hours. Other mechanisms mediated through non-genomic pathways are increasingly appreciated. These are delivered in part by binding of glucocorticoids to nonclassical membrane-bound glucocorticoid receptors or by potentiating the a1-adrenergic action on the bronchial arterial smooth muscles, in addition to other mechanisms. These effects are characterized by their rapid onset and short duration of action. Understanding these different mechanisms will help in the development of new and better drugs to treat this common disease and to develop new improved strategies in our approach to its management. Here, the genomic and non-genomic mechanisms of actions of glucocorticoids in asthma are briefly reviewed, with special emphasis on the current updates of the non-genomic mechanisms.

  7. Cancer Genome Anatomy Project | Office of Cancer Genomics

    Science.gov (United States)

    The National Cancer Institute (NCI) Cancer Genome Anatomy Project (CGAP) is an online resource designed to provide the research community access to biological tissue characterization data. Request a free copy of the CGAP Website Virtual Tour CD from ocg@mail.nih.gov.

  8. Human and mouse genome analysis using array comparative genomic hybridization

    NARCIS (Netherlands)

    Snijders, Antoine Maria

    2004-01-01

    Almost all human cancers as well as developmental abnormalities are characterized by the presence of genetic alterations, most of which target a gene or a particular genomic locus resulting in altered gene expression and ultimately an altered phenotype. Different types of genetic alterations include

  9. Cancer Genome Anatomy Project (CGAP) | Office of Cancer Genomics

    Science.gov (United States)

    CGAP generated a wide range of genomics data on cancerous cells that are accessible through easy-to-use online tools. Researchers, educators, and students can find "in silico" answers to biological questions through the CGAP website. Request a free copy of the CGAP Website Virtual Tour CD from ocg@mail.nih.gov to learn how to navigate the website.

  10. Genome Size Dynamics and Evolution in Monocots

    Directory of Open Access Journals (Sweden)

    Ilia J. Leitch

    2010-01-01

    Full Text Available Monocot genomic diversity includes striking variation at many levels. This paper compares various genomic characters (e.g., range of chromosome numbers and ploidy levels, occurrence of endopolyploidy, GC content, chromosome packaging and organization, genome size between monocots and the remaining angiosperms to discern just how distinctive monocot genomes are. One of the most notable features of monocots is their wide range and diversity of genome sizes, including the species with the largest genome so far reported in plants. This genomic character is analysed in greater detail, within a phylogenetic context. By surveying available genome size and chromosome data it is apparent that different monocot orders follow distinctive modes of genome size and chromosome evolution. Further insights into genome size-evolution and dynamics were obtained using statistical modelling approaches to reconstruct the ancestral genome size at key nodes across the monocot phylogenetic tree. Such approaches reveal that while the ancestral genome size of all monocots was small (1C=1.9 pg, there have been several major increases and decreases during monocot evolution. In addition, notable increases in the rates of genome size-evolution were found in Asparagales and Poales compared with other monocot lineages.

  11. Fungal genome sequencing: basic biology to biotechnology.

    Science.gov (United States)

    Sharma, Krishna Kant

    2016-08-01

    The genome sequences provide a first glimpse into the genomic basis of the biological diversity of filamentous fungi and yeast. The genome sequence of the budding yeast, Saccharomyces cerevisiae, with a small genome size, unicellular growth, and rich history of genetic and molecular analyses was a milestone of early genomics in the 1990s. The subsequent completion of fission yeast, Schizosaccharomyces pombe and genetic model, Neurospora crassa initiated a revolution in the genomics of the fungal kingdom. In due course of time, a substantial number of fungal genomes have been sequenced and publicly released, representing the widest sampling of genomes from any eukaryotic kingdom. An ambitious genome-sequencing program provides a wealth of data on metabolic diversity within the fungal kingdom, thereby enhancing research into medical science, agriculture science, ecology, bioremediation, bioenergy, and the biotechnology industry. Fungal genomics have higher potential to positively affect human health, environmental health, and the planet's stored energy. With a significant increase in sequenced fungal genomes, the known diversity of genes encoding organic acids, antibiotics, enzymes, and their pathways has increased exponentially. Currently, over a hundred fungal genome sequences are publicly available; however, no inclusive review has been published. This review is an initiative to address the significance of the fungal genome-sequencing program and provides the road map for basic and applied research. PMID:25721271

  12. Fungal genome sequencing: basic biology to biotechnology.

    Science.gov (United States)

    Sharma, Krishna Kant

    2016-08-01

    The genome sequences provide a first glimpse into the genomic basis of the biological diversity of filamentous fungi and yeast. The genome sequence of the budding yeast, Saccharomyces cerevisiae, with a small genome size, unicellular growth, and rich history of genetic and molecular analyses was a milestone of early genomics in the 1990s. The subsequent completion of fission yeast, Schizosaccharomyces pombe and genetic model, Neurospora crassa initiated a revolution in the genomics of the fungal kingdom. In due course of time, a substantial number of fungal genomes have been sequenced and publicly released, representing the widest sampling of genomes from any eukaryotic kingdom. An ambitious genome-sequencing program provides a wealth of data on metabolic diversity within the fungal kingdom, thereby enhancing research into medical science, agriculture science, ecology, bioremediation, bioenergy, and the biotechnology industry. Fungal genomics have higher potential to positively affect human health, environmental health, and the planet's stored energy. With a significant increase in sequenced fungal genomes, the known diversity of genes encoding organic acids, antibiotics, enzymes, and their pathways has increased exponentially. Currently, over a hundred fungal genome sequences are publicly available; however, no inclusive review has been published. This review is an initiative to address the significance of the fungal genome-sequencing program and provides the road map for basic and applied research.

  13. Burkholderia pseudomallei genome plasticity associated with genomic island variation

    Directory of Open Access Journals (Sweden)

    Currie Bart J

    2008-04-01

    Full Text Available Abstract Background Burkholderia pseudomallei is a soil-dwelling saprophyte and the cause of melioidosis. Horizontal gene transfer contributes to the genetic diversity of this pathogen and may be an important determinant of virulence potential. The genome contains genomic island (GI regions that encode a broad array of functions. Although there is some evidence for the variable distribution of genomic islands in B. pseudomallei isolates, little is known about the extent of variation between related strains or their association with disease or environmental survival. Results Five islands from B. pseudomallei strain K96243 were chosen as representatives of different types of genomic islands present in this strain, and their presence investigated in other B. pseudomallei. In silico analysis of 10 B. pseudomallei genome sequences provided evidence for the variable presence of these regions, together with micro-evolutionary changes that generate GI diversity. The diversity of GIs in 186 isolates from NE Thailand (83 environmental and 103 clinical isolates was investigated using multiplex PCR screening. The proportion of all isolates positive by PCR ranged from 12% for a prophage-like island (GI 9, to 76% for a metabolic island (GI 16. The presence of each of the five GIs did not differ between environmental and disease-associated isolates (p > 0.05 for all five islands. The cumulative number of GIs per isolate for the 186 isolates ranged from 0 to 5 (median 2, IQR 1 to 3. The distribution of cumulative GI number did not differ between environmental and disease-associated isolates (p = 0.27. The presence of GIs was defined for the three largest clones in this collection (each defined as a single sequence type, ST, by multilocus sequence typing; these were ST 70 (n = 15 isolates, ST 54 (n = 11, and ST 167 (n = 9. The rapid loss and/or acquisition of gene islands was observed within individual clones. Comparisons were drawn between isolates obtained

  14. Advancing Eucalyptus genomics: cytogenomics reveals conservation of Eucalyptus genomes

    Directory of Open Access Journals (Sweden)

    Teresa Mousinho Resina Ribeiro

    2016-04-01

    Full Text Available The genus Eucalyptus encloses several species with high ecological and economic value, being the subgenus Symphyomyrtus one of the most important. Species such as E. grandis and E. globulus are well characterized at the molecular level but knowledge regarding genome and chromosome organization is very scarce. Here we characterized and compared the karyotypes of three economically important species, E. grandis, E. globulus and E. calmadulensis, and three with ecological relevance, E. pulverulenta, E. cornuta and E. occidentalis, through an integrative approach including genome size estimation, fluorochrome banding, rDNA FISH and BAC landing comprising genes involved in lignin biosynthesis. All karyotypes show a high degree of conservation with pericentromeric 35S and 5S rDNA loci in the first and third pairs, respectively. GC-rich heterochromatin was restricted to the 35S locus while the AT-rich het pattern was species-specific. The slight differences in karyotype formulas and distribution of AT-rich het, along with genome sizes estimations, supports the idea of Eucalyptus genome evolution by local expansions of heterochromatin clusters. The unusual co-localization of both rDNA with AT-rich het was attributed mainly to the presence of silent transposable elements in those loci. The cinnamoyl CoA reductase gene (CCR1 previously assessed to linkage group 10 (LG10 was clearly localized distally at the long arm of chromosome 9 establishing an unexpected correlation between the cytogenetic chromosome 9 and the LG10. Our work is novel and contributes to the understanding of Eucalyptus genome organization which is essential to develop successful advanced breeding strategies for this genus.

  15. Genomic inflation factors under polygenic inheritance

    NARCIS (Netherlands)

    Yang, Jian; Weedon, Michael N.; Purcell, Shaun; Lettre, Guillaume; Estrada, Karol; Willer, Cristen J.; Smith, Albert V.; Ingelsson, Erik; O'Connell, Jeffrey R.; Mangino, Massimo; Maegi, Reedik; Madden, Pamela A.; Heath, Andrew C.; Nyholt, Dale R.; Martin, Nicholas G.; Montgomery, Grant W.; Frayling, Timothy M.; Hirschhorn, Joel N.; McCarthy, Mark I.; Goddard, Michael E.; Visscher, Peter M.

    2011-01-01

    Population structure, including population stratification and cryptic relatedness, can cause spurious associations in genome-wide association studies (GWAS). Usually, the scaled median or mean test statistic for association calculated from multiple single-nucleotide-polymorphisms across the genome i

  16. Hapsembler: An Assembler for Highly Polymorphic Genomes

    Science.gov (United States)

    Donmez, Nilgun; Brudno, Michael

    As whole genome sequencing has become a routine biological experiment, algorithms for assembly of whole genome shotgun data has become a topic of extensive research, with a plethora of off-the-shelf methods that can reconstruct the genomes of many organisms. Simultaneously, several recently sequenced genomes exhibit very high polymorphism rates. For these organisms genome assembly remains a challenge as most assemblers are unable to handle highly divergent haplotypes in a single individual. In this paper we describe Hapsembler, an assembler for highly polymorphic genomes, which makes use of paired reads. Our experiments show that Hapsembler produces accurate and contiguous assemblies of highly polymorphic genomes, while performing on par with the leading tools on haploid genomes. Hapsembler is available for download at http://compbio.cs.toronto.edu/hapsembler.

  17. Quasireplicas and universal lengths of microbial genomes

    CERN Document Server

    Hsieh, L C; Luo, L; Ji, F; Lee, H C; Hsieh, Li-Ching; Chang, Chang-Heng; Luo, Liaofu; Ji, Fengmin; Lee, Hoong-Chien

    2003-01-01

    Statistical analysis of distributions of occurrence frequencies of short words in 108 microbial complete genomes reveals the existence of a set of universal "root-sequence lengths" shared by all microbial genomes. These lengths and their universality give powerful clues to the way microbial genomes are grown. We show that the observed genomic properties are explained by a model for genome growth in which primitive genomes grew mainly by maximally stochastic duplications of short segments from an initial length of about 200 nucleotides (nt) to a length of about one million nt typical of microbial genomes. The relevance of the result of this study to the nature of simultaneous random growth and information acquisition by genomes, to the so-called RNA world in which life evolved before the rise of proteins and enzymes and to several other topics are discussed.

  18. V-GAP: Viral genome assembly pipeline

    KAUST Repository

    Nakamura, Yoji

    2015-10-22

    Next-generation sequencing technologies have allowed the rapid determination of the complete genomes of many organisms. Although shotgun sequences from large genome organisms are still difficult to reconstruct perfect contigs each of which represents a full chromosome, those from small genomes have been assembled successfully into a very small number of contigs. In this study, we show that shotgun reads from phage genomes can be reconstructed into a single contig by controlling the number of read sequences used in de novo assembly. We have developed a pipeline to assemble small viral genomes with good reliability using a resampling method from shotgun data. This pipeline, named V-GAP (Viral Genome Assembly Pipeline), will contribute to the rapid genome typing of viruses, which are highly divergent, and thus will meet the increasing need for viral genome comparisons in metagenomic studies.

  19. The Chlamydomonas genome project: a decade on

    Science.gov (United States)

    Blaby, Ian K.; Blaby-Haas, Crysten; Tourasse, Nicolas; Hom, Erik F. Y.; Lopez, David; Aksoy, Munevver; Grossman, Arthur; Umen, James; Dutcher, Susan; Porter, Mary; King, Stephen; Witman, George; Stanke, Mario; Harris, Elizabeth H.; Goodstein, David; Grimwood, Jane; Schmutz, Jeremy; Vallon, Olivier; Merchant, Sabeeha S.; Prochnik, Simon

    2014-01-01

    The green alga Chlamydomonas reinhardtii is a popular unicellular organism for studying photosynthesis, cilia biogenesis and micronutrient homeostasis. Ten years since its genome project was initiated, an iterative process of improvements to the genome and gene predictions has propelled this organism to the forefront of the “omics” era. Housed at Phytozome, the Joint Genome Institute’s (JGI) plant genomics portal, the most up-to-date genomic data include a genome arranged on chromosomes and high-quality gene models with alternative splice forms supported by an abundance of RNA-Seq data. Here, we present the past, present and future of Chlamydomonas genomics. Specifically, we detail progress on genome assembly and gene model refinement, discuss resources for gene annotations, functional predictions and locus ID mapping between versions and, importantly, outline a standardized framework for naming genes. PMID:24950814

  20. The Arab genome: Health and wealth.

    Science.gov (United States)

    Zayed, Hatem

    2016-11-01

    The 22 Arab nations have a unique genetic structure, which reflects both conserved and diverse gene pools due to the prevalent endogamous and consanguineous marriage culture and the long history of admixture among different ethnic subcultures descended from the Asian, European, and African continents. Human genome sequencing has enabled large-scale genomic studies of different populations and has become a powerful tool for studying disease predictions and diagnosis. Despite the importance of the Arab genome for better understanding the dynamics of the human genome, discovering rare genetic variations, and studying early human migration out of Africa, it is poorly represented in human genome databases, such as HapMap and the 1000 Genomes Project. In this review, I demonstrate the significance of sequencing the Arab genome and setting an Arab genome reference(s) for better understanding the molecular pathogenesis of genetic diseases, discovering novel/rare variants, and identifying a meaningful genotype-phenotype correlation for complex diseases.

  1. Comparative Genomics of Green Sulfur Bacteria

    DEFF Research Database (Denmark)

    Ussery, David; Davenport, C; Tümmler, B

    2010-01-01

    Eleven completely sequenced Chlorobi genomes were compared in oligonucleotide usage, gene contents, and synteny. The green sulfur bacteria (GSB) are equipped with a core genome that sustains their anoxygenic phototrophic lifestyle by photosynthesis, sulfur oxidation, and CO(2) fixation. Whole...

  2. Strategies and tools for whole genome alignments

    Energy Technology Data Exchange (ETDEWEB)

    Couronne, Olivier; Poliakov, Alexander; Bray, Nicolas; Ishkhanov,Tigran; Ryaboy, Dmitriy; Rubin, Edward; Pachter, Lior; Dubchak, Inna

    2002-11-25

    The availability of the assembled mouse genome makespossible, for the first time, an alignment and comparison of two largevertebrate genomes. We have investigated different strategies ofalignment for the subsequent analysis of conservation of genomes that areeffective for different quality assemblies. These strategies were appliedto the comparison of the working draft of the human genome with the MouseGenome Sequencing Consortium assembly, as well as other intermediatemouse assemblies. Our methods are fast and the resulting alignmentsexhibit a high degree of sensitivity, covering more than 90 percent ofknown coding exons in the human genome. We have obtained such coveragewhile preserving specificity. With a view towards the end user, we havedeveloped a suite of tools and websites for automatically aligning, andsubsequently browsing and working with whole genome comparisons. Wedescribe the use of these tools to identify conserved non-coding regionsbetween the human and mouse genomes, some of which have not beenidentified by other methods.

  3. Bioinformatica ten behoeve van genomics

    NARCIS (Netherlands)

    Pennings JLA; Hoebee B; TOX

    2007-01-01

    Sinds enkele jaren wordt op het RIVM genomicsonderzoek uitgevoerd. Genomics omvat grootschalig onderzoek naar het erfelijk materiaal (DNA) van organismen. Dit onderzoek levert inzicht op in de manier waarop erfelijke eigenschappen zich vertalen naar het functioneren van een cel, en uiteindelijk ee

  4. Causal Factors in Genome Control

    NARCIS (Netherlands)

    O'Duibhir, E.

    2015-01-01

    The aim of this thesis is to study how genes are switched on and off in a coordinated way across an entire genome. In order to do this yeast is used as a model organism. The mechanisms that control gene expression in yeast are very similar to those of human cells. Chapter 1 provides a general introd

  5. Rosaceae: Taxonomy, Economic Importance, Genomics

    Science.gov (United States)

    This chapter presents an introduction for the book Genetics and Genomics of the Rosaceae. It reviews the origins of the Rose family, Rosaceae. Theories of the origin of this plant family are given. The first descriptions by Michel Adanson and Antoine Laurent de Jussieu in the 1700s, controversial t...

  6. Genomics: Implementatie, toepassing en toekomst

    NARCIS (Netherlands)

    Pennings JLA; Hoebee B; TOX

    2007-01-01

    Genomics - the large scale analysis of hereditary information encoded in the DNA - has been implemented at the National Institute for Public Health and the Environment (RIVM) in the Netherlands. In the near future other large-scale technologies will become important for the RIVM, including proteomic

  7. Small RNA in rice genome

    Institute of Scientific and Technical Information of China (English)

    王凯; 朱小蓬; 钟兰; 陈润生

    2002-01-01

    Rice has many characteristics of a model plant. The recent completion of the draft of the rice genome represents an important advance in our knowledge of plant biology and also has an important contribution to the understanding of general genomic evolution. Besides the rice genome finishing map, the next urgent step for rice researchers is to annotate the genes and noncoding functional sequences. The recent work shows that noncoding RNAs (ncRNAs) play significant roles in biological systems. We have explored all the known small RNAs (a kind of ncRNA) within rice genome and other six species sequences, including Arabidopsis, maize, yeast, worm, mouse and pig. As a result we find 160 out of 552 small RNAs (sRNAs) in database have homologs in 108 rice scaffolds, and almost all of them (99.41%) locate in intron regions of rice by gene predication. 19 sRNAs only appear in rice. More importantly, we find two special U14 sRNAs: one is located in a set of sRNA ZMU14SNR9(s) which only appears in three plants, 86% sequences of them can be compared as the same sequence in rice, Arabidopsis and maize; the other conserved sRNA XLHS7CU14 has a segment which appears in almost all these species from plants to animals. All these results indicate that sRNA do not have evident borderline between plants and animals.

  8. Comparative genomics of Dothideomycete fungi

    NARCIS (Netherlands)

    Burgt, van der A.

    2014-01-01

    Fungi are a diverse group of eukaryotic micro-organisms particularly suited for comparative genomics analyses. Fungi are important to industry, fundamental science and many of them are notorious pathogens of crops, thereby endangering global food supply. Dozens of fungi have been sequenced in the la

  9. Evolutionary genomics of animal personality.

    Science.gov (United States)

    van Oers, Kees; Mueller, Jakob C

    2010-12-27

    Research on animal personality can be approached from both a phenotypic and a genetic perspective. While using a phenotypic approach one can measure present selection on personality traits and their combinations. However, this approach cannot reconstruct the historical trajectory that was taken by evolution. Therefore, it is essential for our understanding of the causes and consequences of personality diversity to link phenotypic variation in personality traits with polymorphisms in genomic regions that code for this trait variation. Identifying genes or genome regions that underlie personality traits will open exciting possibilities to study natural selection at the molecular level, gene-gene and gene-environment interactions, pleiotropic effects and how gene expression shapes personality phenotypes. In this paper, we will discuss how genome information revealed by already established approaches and some more recent techniques such as high-throughput sequencing of genomic regions in a large number of individuals can be used to infer micro-evolutionary processes, historical selection and finally the maintenance of personality trait variation. We will do this by reviewing recent advances in molecular genetics of animal personality, but will also use advanced human personality studies as case studies of how molecular information may be used in animal personality research in the near future. PMID:21078651

  10. Genomic counseling: next generation counseling.

    Science.gov (United States)

    Mills, Rachel; Haga, Susanne B

    2014-08-01

    Personalized medicine continues to expand with the development and increasing use of genome-based testing. While these advances present new opportunities for diagnosis and risk assessment, they also present challenges to clinical delivery. Genetic counselors will play an important role in ushering in this new era of testing; however, it will warrant a shift from traditional genetic counseling to "genomic counseling." This shift will be marked by a move from reactive genetic testing for diagnosis of primarily single-gene diseases to proactive genome-based testing for multiple complex diseases for the purpose of disease prevention. It will also require discussion of risk information for a number of diseases, some of which may have low relative risks or weak associations, and thus, may not substantially impact clinical care. Additionally, genomic counselors will expand their roles, particularly in the area of health promotion to reduce disease risk. This additional role will require a style of counseling that is more directive than traditional counseling and require greater knowledge about risk reducing behaviors and disease screening.

  11. Genomic profile of ovarian carcinomas

    OpenAIRE

    Micci, Francesca; Haugom, Lisbeth; Vera M. Abeler; Davidson, Ben; Tropé, Claes G; Heim, Sverre

    2014-01-01

    Background It is known that all tumors studied in sufficient number to draw conclusions show characteristic/specific chromosomal rearrangements, and the identification of these chromosomes and the genes rearranged behind the aberrations may ultimately lead to a tailor-made therapy for each cancer patient. Knowledge about the acquired genomic aberrations of ovarian carcinomas is still unsatisfactory. Methods ...

  12. A genome befitting a monarch.

    Science.gov (United States)

    Stensmyr, Marcus C; Hansson, Bill S

    2011-11-23

    The monarch butterfly is famous for its annual fall migration from eastern North America to central Mexico, but it has also been an important model for studies in long-distance migration. Now, Zhan et al. present the genome of the monarch, opening up the detailed characterization of the butterfly's navigational system and unique social life. PMID:22118454

  13. Fungal genome resources at NCBI.

    Science.gov (United States)

    Robbertse, B; Tatusova, T

    2011-09-01

    The National Center for Biotechnology Information (NCBI) is well known for the nucleotide sequence archive, GenBank and sequence analysis tool BLAST. However, NCBI integrates many types of biomolecular data from variety of sources and makes it available to the scientific community as interactive web resources as well as organized releases of bulk data. These tools are available to explore and compare fungal genomes. Searching all databases with Fungi [organism] at http://www.ncbi.nlm.nih.gov/ is the quickest way to find resources of interest with fungal entries. Some tools though are resources specific and can be indirectly accessed from a particular database in the Entrez system. These include graphical viewers and comparative analysis tools such as TaxPlot, TaxMap and UniGene DDD (found via UniGene Homepage). Gene and BioProject pages also serve as portals to external data such as community annotation websites, BioGrid and UniProt. There are many different ways of accessing genomic data at NCBI. Depending on the focus and goal of research projects or the level of interest, a user would select a particular route for accessing genomic databases and resources. This review article describes methods of accessing fungal genome data and provides examples that illustrate the use of analysis tools. PMID:22737589

  14. Recent advance in carrot genomics

    Science.gov (United States)

    In recent years there has been an effort towards the development of genomic resources in carrot. The number of available sequences for carrot in public databases has increased recently. This has allowed the design of SSRs markers, COS markers and a high-throughput SNP assay for genotyping. Additiona...

  15. Heart failure: advances through genomics

    NARCIS (Netherlands)

    E.E. Creemers; A.A. Wilde; Y.M. Pinto

    2011-01-01

    Heart failure is an increasingly prevalent and highly lethal disease that is most often caused by underlying pathologies, such as myocardial infarction or hypertension, but it can also be the result of a single gene mutation. Comprehensive genetic and genomic approaches are starting to disentangle t

  16. The potato psyllid genome project

    Science.gov (United States)

    The potato psyllid (Bactericera cockerelli) is a Hemipteran pest of solanaceous plants and limits potato and tomato production by the transmission of Candidatus Liberibacter solanacearum. Genomic information on the potato psyllid is limited but is vital in developing appropriate management strategi...

  17. The 1000 bull genome project

    Science.gov (United States)

    To meet growing global demands for high value protein from milk and meat, rates of genetic gain in domestic cattle must be accelerated. At the same time, animal health and welfare must be considered. The 1000 bull genomes project supports these goals by providing annotated sequence variants and ge...

  18. Genomics, Patents, and Human Rights

    NARCIS (Netherlands)

    Korthals, Michiel

    2016-01-01

    The life sciences have changed enormously: new disciplines, such as genomic and metabolomic technologies, have revolutionized the descriptive and normative power wielded by these disciplines. The technological developments accompanied by new scientific approaches and positions make the daily prac

  19. Unleashing the Genome of Brassica Rapa

    OpenAIRE

    Tang, Haibao; Lyons, Eric

    2012-01-01

    The completion and release of the Brassica rapa genome is of great benefit to researchers of the Brassicas, Arabidopsis, and genome evolution. While its lineage is closely related to the model organism Arabidopsis thaliana, the Brassicas experienced a whole genome triplication subsequent to their divergence. This event contemporaneously created three copies of its ancestral genome, which had diploidized through the process of homeologous gene loss known as fractionation. By the fractionation ...

  20. RNA virus genomics: a world of possibilities

    OpenAIRE

    Edward C Holmes

    2009-01-01

    The increasing availability of complete genome sequences of RNA viruses has the potential to shed new light on fundamental aspects of their biology. Here, I use case studies of 3 RNA viruses to explore the impact of genomic sequence data, with particular emphasis on influenza A virus. Notably, the studies of RNA virus genomics undertaken to date largely focused on issues of evolution and epidemiology, and they have given these disciplines new impetus. However, genomic data have so far made fe...

  1. Evolution, language and analogy in functional genomics.

    Science.gov (United States)

    Benner, S A; Gaucher, E A

    2001-07-01

    Almost a century ago, Wittgenstein pointed out that theory in science is intricately connected to language. This connection is not a frequent topic in the genomics literature. But a case can be made that functional genomics is today hindered by the paradoxes that Wittgenstein identified. If this is true, until these paradoxes are recognized and addressed, functional genomics will continue to be limited in its ability to extrapolate information from genomic sequences.

  2. Minimal model for genome evolution and growth

    OpenAIRE

    Hsieh, L. C.; Luo, L. F.; Ji, F. M.; Lee, H C

    2002-01-01

    Textual analysis of typical microbial genomes reveals that they have the statistical characteristics of a DNA sequence of a much shorter length. This peculiar property supports an evolutionary model in which a genome evolves by random mutation but primarily grows by random segmental self-copying. That genomes grew mostly by self-copying is consistent with the observation that repeat sequences in all genomes are widespread and intragenomic and intergenomic homologous genes are preponderance ac...

  3. Clinical Implications of the Cancer Genome

    OpenAIRE

    MacConaill, Laura E; Garraway, Levi A

    2010-01-01

    Cancer is a disease of the genome. Most tumors harbor a constellation of structural genomic alterations that may dictate their clinical behavior and treatment response. Whereas elucidating the nature and importance of these genomic alterations has been the goal of cancer biologists for several decades, ongoing global genome characterization efforts are revolutionizing both tumor biology and the optimal paradigm for cancer treatment at an unprecedented scope. The pace of advance has been empow...

  4. The Human Genome Browser at UCSC

    OpenAIRE

    Kent, W James; Sugnet, Charles W.; Furey, Terrence S.; Roskin, Krishna M; Pringle, Tom H.; Zahler, Alan M.; Haussler, and David

    2002-01-01

    As vertebrate genome sequences near completion and research refocuses to their analysis, the issue of effective genome annotation display becomes critical. A mature web tool for rapid and reliable display of any requested portion of the genome at any scale, together with several dozen aligned annotation tracks, is provided at http://genome.ucsc.edu. This browser displays assembly contigs and gaps, mRNA and expressed sequence tag alignments, multiple gene predictions, cross-species homologies,...

  5. Genomics for Disease Treatment and Prevention

    OpenAIRE

    Bloss, Cinnamon S.; Jeste, Dilip V.; Schork, Nicholas J.

    2010-01-01

    The enormous advances in genetics and genomics of the past decade have the potential to revolutionize health care, including mental health care, and bring about a system predominantly characterized by the practice of genomic and personalized medicine. We briefly review the history of genetics and genomics and present heritability estimates for major chronic diseases of aging and neuropsychiatric disorders. We then assess the extent to which the results of genetic and genomic studies are curre...

  6. Searching and Indexing Genomic Databases via Kernelization

    Directory of Open Access Journals (Sweden)

    Travis eGagie

    2015-02-01

    Full Text Available The rapid advance of DNA sequencing technologies has yielded databases of thousands of genomes. To search and index these databases effectively, it is important that we take advantage of the similarity between those genomes. Several authors have recently suggested searching or indexing only one reference genome and the parts of the other genomes where they differ. In this paper we survey the twenty-year history of this idea and discuss its relation to kernelization in parameterized complexity.

  7. International network of cancer genome projects.

    OpenAIRE

    Aretz, Axel; Bernabé, Rosa R.; Eerola, Iiro; Hemsley, Fiona M.; Jennings, Jennifer L.; Kerr, David; Klatt, Peter; Kolar, Patrik; Lane, David P; Laplace, Frank; Nettekoven, Gerd; Remacle, Jacques; WATANABE, Koichi; Yuen, Matthew M. F.; Knoppers, Bartha M.

    2010-01-01

    The International Cancer Genome Consortium (ICGC) was launched to coordinate large-scale cancer genome studies in tumours from 50 different cancer types and/or subtypes that are of clinical and societal importance across the globe. Systematic studies of more than 25,000 cancer genomes at the genomic, epigenomic and transcriptomic levels will reveal the repertoire of oncogenic mutations, uncover traces of the mutagenic influences, define clinically relevant subtypes for prognosis and therapeut...

  8. Genome chaos: survival strategy during crisis.

    Science.gov (United States)

    Liu, Guo; Stevens, Joshua B; Horne, Steven D; Abdallah, Batoul Y; Ye, Karen J; Bremer, Steven W; Ye, Christine J; Chen, David J; Heng, Henry H

    2014-01-01

    Genome chaos, a process of complex, rapid genome re-organization, results in the formation of chaotic genomes, which is followed by the potential to establish stable genomes. It was initially detected through cytogenetic analyses, and recently confirmed by whole-genome sequencing efforts which identified multiple subtypes including "chromothripsis", "chromoplexy", "chromoanasynthesis", and "chromoanagenesis". Although genome chaos occurs commonly in tumors, both the mechanism and detailed aspects of the process are unknown due to the inability of observing its evolution over time in clinical samples. Here, an experimental system to monitor the evolutionary process of genome chaos was developed to elucidate its mechanisms. Genome chaos occurs following exposure to chemotherapeutics with different mechanisms, which act collectively as stressors. Characterization of the karyotype and its dynamic changes prior to, during, and after induction of genome chaos demonstrates that chromosome fragmentation (C-Frag) occurs just prior to chaotic genome formation. Chaotic genomes seem to form by random rejoining of chromosomal fragments, in part through non-homologous end joining (NHEJ). Stress induced genome chaos results in increased karyotypic heterogeneity. Such increased evolutionary potential is demonstrated by the identification of increased transcriptome dynamics associated with high levels of karyotypic variance. In contrast to impacting on a limited number of cancer genes, re-organized genomes lead to new system dynamics essential for cancer evolution. Genome chaos acts as a mechanism of rapid, adaptive, genome-based evolution that plays an essential role in promoting rapid macroevolution of new genome-defined systems during crisis, which may explain some unwanted consequences of cancer treatment.

  9. Genetics and Genomics of Pathogens: Fighting Infections with Genome-Sequencing Technology.

    Science.gov (United States)

    Plavskin, Alexandra

    2016-01-01

    Discussions of clinical genetics and genomics often focus on screening for disease-causing genes in humans and the promise of targeted therapies. Another important area of research is analysis of pathogen genomes. Genetics and genomics-based approaches, such as population genomics and phylogenetics, provide insight into mechanisms of resistance, sources of infections, and pathogen transmission routes.

  10. Value of a newly sequenced bacterial genome.

    Science.gov (United States)

    Barbosa, Eudes Gv; Aburjaile, Flavia F; Ramos, Rommel Tj; Carneiro, Adriana R; Le Loir, Yves; Baumbach, Jan; Miyoshi, Anderson; Silva, Artur; Azevedo, Vasco

    2014-05-26

    Next-generation sequencing (NGS) technologies have made high-throughput sequencing available to medium- and small-size laboratories, culminating in a tidal wave of genomic information. The quantity of sequenced bacterial genomes has not only brought excitement to the field of genomics but also heightened expectations that NGS would boost antibacterial discovery and vaccine development. Although many possible drug and vaccine targets have been discovered, the success rate of genome-based analysis has remained below expectations. Furthermore, NGS has had consequences for genome quality, resulting in an exponential increase in draft (partial data) genome deposits in public databases. If no further interests are expressed for a particular bacterial genome, it is more likely that the sequencing of its genome will be limited to a draft stage, and the painstaking tasks of completing the sequencing of its genome and annotation will not be undertaken. It is important to know what is lost when we settle for a draft genome and to determine the "scientific value" of a newly sequenced genome. This review addresses the expected impact of newly sequenced genomes on antibacterial discovery and vaccinology. Also, it discusses the factors that could be leading to the increase in the number of draft deposits and the consequent loss of relevant biological information. PMID:24921006

  11. Impact of genomics on microbial food safety

    NARCIS (Netherlands)

    Abee, T.; Schaik, van W.; Siezen, R.J.

    2004-01-01

    Genome sequences are now available for many of the microbes that cause food-borne diseases. The information contained in pathogen genome sequences, together with the development of themed and whole-genome DNA microarrays and improved proteomics techniques, might provide tools for the rapid detection

  12. Genomic instability and cancer: an introduction

    Institute of Scientific and Technical Information of China (English)

    Zhiyuan Shen

    2011-01-01

    @@ Genomic instability as a major driving force of tumorigenesis.The ultimate goal of cell division for most non-cancerous somatic cells is to accurately duplicate the genome and then evenly divide the duplicated genome into the two daughter cells.This ensures that the daughter cells will have exactly the same genetic material as their parent cell.

  13. Pig genome sequence - analysis and publication strategy

    NARCIS (Netherlands)

    Archibald, A.L.; Bolund, L.; Churcher, C.; Fredholm, M.; Groenen, M.A.M.; Harlizius, B.

    2010-01-01

    Background - The pig genome is being sequenced and characterised under the auspices of the Swine Genome Sequencing Consortium. The sequencing strategy followed a hybrid approach combining hierarchical shotgun sequencing of BAC clones and whole genome shotgun sequencing. Results - Assemblies of the B

  14. Leaner and meaner genomes in Escherichia coli

    DEFF Research Database (Denmark)

    Ussery, David

    2006-01-01

    A 'better' Escherichia coli K-12 genome has recently been engineered in which about 15% of the genome has been removed by planned deletions. Comparison with related bacterial genomes that have undergone a natural reduction in size suggests that there is plenty of scope for yet more deletions....

  15. A new guide to the human genome

    Energy Technology Data Exchange (ETDEWEB)

    Marx, J.

    1995-12-22

    The construction of a detailed physical map of the human genome, with 15,000 sequence-based landmarks, opens the door to genome-wide sequencing. This article summarizes the researchers, the research, the approach, and the usefulness of a new physical map of the human genome.

  16. Practical Solutions for Protecting Individual Genomic Privacy

    OpenAIRE

    Fellay, Jacques; Raisaro, Jean Louis; Huang, Zhicong; Humbert, Mathias; Ayday, Erman; Mc Laren, Paul Jack; Hubaux, Jean-Pierre; Telenti, Amalio

    2014-01-01

    The increasing availability of genomic data has major implications for personal privacy. The issues raised by genomic privacy reside at the crossroads of medicine, computer science, legislation and public policy. We here describe the design and development of new privacy enhancing technologies that aim to find the optimal balance between usability and privacy of genomic data in clinical care and in biomedical research.

  17. Genome re-annotation: a wiki solution?

    OpenAIRE

    Salzberg, Steven L.

    2007-01-01

    The annotation of most genomes becomes outdated over time, owing in part to our ever-improving knowledge of genomes and in part to improvements in bioinformatics software. Unfortunately, annotation is rarely if ever updated and resources to support routine reannotation are scarce. Wiki software, which would allow many scientists to edit each genome's annotation, offers one possible solution.

  18. Value of a newly sequenced bacterial genome

    Institute of Scientific and Technical Information of China (English)

    Eudes; GV; Barbosa; Flavia; F; Aburjaile; Rommel; TJ; Ramos; Adriana; R; Carneiro; Yves; Le; Loir; Jan; Baumbach; Anderson; Miyoshi; Artur; Silva; Vasco; Azevedo

    2014-01-01

    Next-generation sequencing(NGS) technologies have made high-throughput sequencing available to medium- and small-size laboratories, culminating in a tidal wave of genomic information. The quantity of sequenced bacterial genomes has not only brought excitement to the field of genomics but also heightened expectations that NGS would boost antibacterial discovery and vaccine development. Although many possible drug and vaccine targets have been discovered, the success rate of genome-based analysis has remained below expectations. Furthermore, NGS has had consequences for genome quality, resulting in an exponential increase in draft(partial data) genome deposits in public databases. If no further interests are expressed for a particular bacterial genome, it is more likely that the sequencing of its genome will be limited to a draft stage, and the painstaking tasks of completing the sequencing of its genome and annotation will not be undertaken. It is important to know what is lost when we settle for a draft genome and to determine the "scientific value" of a newly sequenced genome. This review addresses the expected impact of newly sequenced genomes on antibacterial discovery and vaccinology. Also, it discusses the factors that could be leading to the increase in the number of draft deposits and the consequent loss of relevant biological information.

  19. The Latest Buzz in Comparative Genomics

    OpenAIRE

    Kulathinal, Rob J.; Hartl, Daniel L.

    2005-01-01

    A second species of fruit fly has just been added to the growing list of organisms with complete and annotated genome sequences. The publication of the Drosophila pseudoobscura sequence provides a snapshot of how genomes have changed over tens of millions of years and sets the stage for the analysis of more fly genomes.

  20. All about the Human Genome Project (HGP)

    Science.gov (United States)

    ... the full human sequence All About The Human Genome Project (HGP) The Human Genome Project (HGP) was one of the great feats of ... Model Organisms A Quarter Century after the Human Genome Project's Launch: Lessons Beyond the Base Pairs October 1, ...