35 research outputs found

    Genome of Herbaspirillum seropedicae Strain SmR1, a Specialized Diazotrophic Endophyte of Tropical Grasses

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    The molecular mechanisms of plant recognition, colonization, and nutrient exchange between diazotrophic endophytes and plants are scarcely known. Herbaspirillum seropedicae is an endophytic bacterium capable of colonizing intercellular spaces of grasses such as rice and sugar cane. The genome of H. seropedicae strain SmR1 was sequenced and annotated by The Paraná State Genome Programme—GENOPAR. The genome is composed of a circular chromosome of 5,513,887 bp and contains a total of 4,804 genes. The genome sequence revealed that H. seropedicae is a highly versatile microorganism with capacity to metabolize a wide range of carbon and nitrogen sources and with possession of four distinct terminal oxidases. The genome contains a multitude of protein secretion systems, including type I, type II, type III, type V, and type VI secretion systems, and type IV pili, suggesting a high potential to interact with host plants. H. seropedicae is able to synthesize indole acetic acid as reflected by the four IAA biosynthetic pathways present. A gene coding for ACC deaminase, which may be involved in modulating the associated plant ethylene-signaling pathway, is also present. Genes for hemagglutinins/hemolysins/adhesins were found and may play a role in plant cell surface adhesion. These features may endow H. seropedicae with the ability to establish an endophytic life-style in a large number of plant species

    The complete genome sequence of Chromobacterium violaceum reveals remarkable and exploitable bacterial adaptability

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    Chromobacterium violaceum is one of millions of species of free-living microorganisms that populate the soil and water in the extant areas of tropical biodiversity around the world. Its complete genome sequence reveals (i) extensive alternative pathways for energy generation, (ii) ≈500 ORFs for transport-related proteins, (iii) complex and extensive systems for stress adaptation and motility, and (iv) wide-spread utilization of quorum sensing for control of inducible systems, all of which underpin the versatility and adaptability of the organism. The genome also contains extensive but incomplete arrays of ORFs coding for proteins associated with mammalian pathogenicity, possibly involved in the occasional but often fatal cases of human C. violaceum infection. There is, in addition, a series of previously unknown but important enzymes and secondary metabolites including paraquat-inducible proteins, drug and heavy-metal-resistance proteins, multiple chitinases, and proteins for the detoxification of xenobiotics that may have biotechnological applications

    Evidence for the endophytic colonization of Phaseolus vulgaris(common bean) roots by the diazotroph Herbaspirillum seropedicae

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    Herbaspirillum seropedicae is an endophytic diazotrophic bacterium, which associates with important agricultural plants. In the present study, we have investigated the attachment to and internal colonization of Phaseolus vulgaris roots by the H. seropedicae wild-type strain SMR1 and by a strain of H. seropedicae expressing a red fluorescent protein (DsRed) to track the bacterium in the plant tissues. Two-day-old P. vulgaris roots were incubated at 30°C for 15 min with 6 x 10(8) CFU/mL H. seropedicae SMR1 or RAM4. Three days after inoculation, 4 x 10(4) cells of endophytic H. seropedicae SMR1 were recovered per gram of fresh root, and 9 days after inoculation the number of endophytes increased to 4 x 10(6) CFU/g. The identity of the recovered bacteria was confirmed by amplification and sequencing of the 16SrRNA gene. Furthermore, confocal microscopy of P. vulgaris roots inoculated with H. seropedicae RAM4 showed that the bacterial cells were attached to the root surface 15 min after inoculation; fluorescent bacteria were visible in the internal tissues after 24 h and were found in the central cylinder after 72 h, showing that H. seropedicae RAM4 is capable of colonizing the roots of the dicotyledon P. vulgaris. Determination of dry weight of common bean inoculated with H. seropedicae SMR1 suggested that this bacterium has a negative effect on the growth of P. vulgaris

    Naringenin Regulates Expression of Genes Involved in Cell Wall Synthesis in Herbaspirillum seropedicae▿

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    Five thousand mutants of Herbaspirillum seropedicae SmR1 carrying random insertions of transposon pTnMod-OGmKmlacZ were screened for differential expression of LacZ in the presence of naringenin. Among the 16 mutants whose expression was regulated by naringenin were genes predicted to be involved in the synthesis of exopolysaccharides, lipopolysaccharides, and auxin. These loci are probably involved in establishing interactions with host plants

    The fibromyalgia bladder index

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    AB The aim of this study was to determine whether an existing outcome measure, the Interstitial Cystitis Symptom and Problem Index (ICSI/ICPI), is a valid, reliable, and clinically relevant instrument to assess the sensory urinary symptoms in women with fibromyalgia syndrome (FM). Ninety women with American College of Rheumatology 90 FM and who had at least two sensory bladder symptoms participated in the study. All underwent urological screening to exclude lower urinary tract pathology. All participants completed the following: ICSI/ICPI, Fibromyalgia Impact Questionnaire (FIQ), Medical Outcome Study Short Form 36, King's Health Questionnaire (KHQ), and Vulval Symptom Assessment Scale. Assessment was made for internal consistency reliability, test-retest reliability, and concurrent validity. Factor analysis was used to assess the internal structure of the scale. Factor analysis displayed two separate components of symptom and problem combinations as distinct from the original ICSI/ICPI developed for the interstitial cystitis population. The eight items of the index configured differently and formed two subscales of a newly developed Fibromyalgia Bladder Index. The two subscales of this index include the Bladder Urgency and Pain Subscale and the Bladder Frequency and Nocturia Subscale. This index has high internal consistency reliability (Cronbach's alpha coefficient of 0.81), test-retest reliability showing intraclass correlation of 0.85, and high concurrent validity through correlations between the Fibromyalgia Bladder Index and the KHQ (0.735, p = 0.000) and the FIQ (0.433, p = 0.000). This more specific configuration of the ICSI/ICPI better reflects FM bladder symptomatology. The Fibromyalgia Bladder Index is a validated FM-specific instrument that captures information about the sensory bladder symptoms and their impact in this fibromyalgia population. This instrument should allow for better understanding and management of this important fibromyalgia-associated problem
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