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katherine-medina

Plants | Free Full-Text | Expression of a Stilbene Synthase Gene from the Vitis labrusc... - 0 views

  • Stilbenes are found in plants of different families, but the best studied stilbene is resveratrol (3,5,4′-trihydroxystilbene) isolated from grape plants.
  • Resveratrol synthesis in transgenic plants did not always render them fully resistant to one or another pathogen.
  • The aim of our investigation was to isolate a VlvSTS stilbene synthase gene from the hybrid grape V. labrusca x V. vinifera L. and obtain transgenic tobacco plants overexpressing the gene to study their resistance to a number of bacterial and fungal pathogens, among them bacteria as E. carotovora and fungi as B. cinerea, F. oxysporum, F. sporotrichioides, F. culmorum.
  • ...16 more annotations...
  • by PCR. F
    • katherine-medina
       
      PCR is a method with which scientists are able to amplify a gene
  • Based on the results of the VlvSTS gene transcription analysis, seven transgenic tobacco lines were selected for further experiments.
  • Expression of the VlvSTS gene in tobacco plants led to a significant increase in the pollen grain size, but with a tendency to a decrease in the total number of pollen grains per anther
    • katherine-medina
       
      Too much of that gene leads to a decrease of fertility.
  • In all tests with E. carotovora bacteria, transgenic plants expressing the VlvSTS gene demonstrated a significantly higher resistance versus control plants
    • katherine-medina
       
      interesting
  • The leaf involvement was significantly smaller in transgenic plants expressing the VlvSTS gene.
  • Overexpression of the VlvSTS gene reduced the corolla pigmentation in transgenic plants.
    • katherine-medina
       
      Why did the overexpression of that gene reduce the corolla pgmentation.
  • binary vector
    • katherine-medina
       
      like a DNA transfer
  • showed a significant fertility reduction,
  • For the first time it was shown that plants expressing the VlvSTS gene had enhanced resistance to the bacterial pathogen E. carotovora subsp. carotovora B15.
    • katherine-medina
       
      Interesting that it took this long for it to be shown that this specific stilbene can fight against certain pathogens.
  • Interestingly, resistance correlated with the expression level of the stilbene synthase gene. In plants with a higher gene expression (L10 and L23), the area of Erwinia-caused leaf damage was in a range from 0 to 40% respect to the control, while the leaves of line L24 were affected up to 60–100%.
  • hile in transgenic lines, the lysis areas were significantly smaller, probably due to the synthesis of the phytoalexin resveratrol.
  • Some studies showed that Arabidopsis plants transformed with wild grape stilbene synthase genes responded to a pathogen attack by activating genes responsible for the synthesis of signaling molecules such as salicylic and jasmonic acids (SA and JA, respectively) [
  • Our data show a decrease in the total flavonoid content in the flower petals but not in the leaves of plants upon expression of the VlvSTS gene.
    • katherine-medina
       
      That seems rather odd.
  • We were the first to show that transgenic tobacco plants carrying the VlvSTS gene had a significantly larger pollen grain size and a smaller number of pollen grains per anther. At the same time, the number of fertile pollen grains decreased, especially in the plant line with the highest expression of the VlvSTS gene.
  • For example, in apple plants with the grape stilbene synthase gene Vst1 under its own promoter, the expression of the gene had no effect on pollen development
  • The study showed that the expression of a VlvSTS stilbene syntase gene in tobacco transgenic plants increases their resistance to bacterial pathogen E. carotovora. There was a significant reduction of disease symptoms after infection of leaves by grey mould fungus B. cinerea, but not to Fusarium fungi. We were the first to show that transgenic tobacco plants carrying the VlvSTS gene had a significantly larger pollen grain size and a smaller number of pollen grains per anther. The number of fertile pollen grains decreased, especially in the plant line with the highest expression of the VlvSTS gene. These changes resulted in a decreased weight of seed bolls in the transgenic tobacco lines.
    • katherine-medina
       
      Overall, this article is one that I may come back to depending on what path I go down when searching to develop a research topic further.
katherine-medina

Restoring the activity of the antibiotic aztreonam using the polyphenol epigallocatechi... - 0 views

  • epigallocatechin gallate (EGCG) against multidrug-resistant clinical isolates of Pseudomonas aeruginosa
    • katherine-medina
       
      Epigallocatechin (EGCG) is a type of catechin or a natural phenol antioxidant. It is commonly found in tea leaves, plums, apple skin, and onions. Sidenote this bacteria is found in green tea
  • However, with resistance increasing against many classes of antibiotic, clinicians often use multiple combinations to treat critically ill patients
  • relatively low toxicity of EGCG to human keratinocytes and G. mellonella larvae.
  • ...12 more annotations...
  • . EGCG was able to restore the activity of aztreonam against MDR P. aeruginosa . The data presented support further evaluation of the aztreonam–EGCG combination and highlight its potential for use in clinical medici
  • Polyphenols
    • katherine-medina
       
      These are bioactive compounds that are found in fruits and leaves of plants. The main focus of this paper is a type of polyphenol.
  • with EGCG in checkerboard assays, susceptibility increased in P. aeruginosa (n=16, 100%), with the combination proving synergistic in all strains tested
    • katherine-medina
       
      Wow. for how much it increased the susceptibility.
  • Another option to restore the activity of aztreonam against bacterial strains with multiple resistance mechanisms would be to use polyphenols
  • he results demonstrate that synergy between aztreonam and EGCG exists [fractional inhibitory concentration indices (FICIs) 0.02-0.5], with the combination affording significantly (P=<0.05) enhanced bacterial killing, with a >3 log10 reduction in colony-forming units ml−1 at 24 h
  • To access synergy between aztreonam and EGCG, checkerboard assays were performed
  • Chemicals, media, bacterial isolates and animals
    • katherine-medina
       
      Really important to look back at these methods because even though it may not be feasible for me to do an experiment like this one, it still has valuable information for me to look at.
  • Synergy was also found between EGCG and the third-generation cephalosporin, cefotaxime
  • with scores of 64 and 56 out of a maximum of 64 for strains PA2 and PA6, respectively.
  • the increased activity may also be due to the inhibition of the non-mevalonate pathway, resulting in increased susceptibility to aztreonam.
  • Overall, the G. mellonella assays demonstrated that the aztreonam–EGCG combination was superior to monotherapy with either agent against every isolate tested, with significantly lower larval mortality rates
  • In conclusion, the results from this study demonstrate that synergy exists between aztreonam and EGCG against MDR clinical strains of P. aeruginosa in vitro and in vivo. EGCG is also able to restore the antibacterial activity of aztreonam to concentrations below the EUCAST susceptibility breakpoint for P. aeruginosa , potentially expanding and extending its useful therapeutic lifespan. Further work should be undertaken to determine if this combination has the potential to treat clinical infections caused by MDR P. aeruginosa .
    • katherine-medina
       
      My final thought for this article is as follows: 1. This brings up a very interesting topic for me to dig into (polyphenols & antibiotics)
  •  
    A gateway article for me to further my search into the scientific realm involving polyphenols that aid antibiotics.
Hannah Herrera

Space travel alters gene expression in white blood cells, weakening our immune system -... - 1 views

  • Space travel alters gene expression in white blood cells, weakening our immune system
    • Hannah Herrera
       
      very interesting article, there is a conclusion with insights to this underlining issue in the "read original paper" link in red. I overall think its a ear pricking issue that has yet to be solve or given the clear conclusion as to why it happens in the first place.
  • pre-flight strength: the length of this period is likely to depend on age, sex, genetic differences, and childhood exposure to pathogens.
  • These observations suggest that our immune system might be weakened by space travel.
    • Hannah Herrera
       
      could it have a possible connection with the strong gravitational pull while actually going up to space? (like the continuing feeling of a steep rollercoaster drop).
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  • change in gene expression of leukocytes under microgravity is triggered by ‘fluid shift’, where blood plasma is redistributed from the lower to the upper part of the body, including the lymphatic system. This causes a reduction in plasma volume by between 10% and 15% within the first few days in space. Fluid shift is known to be accompanied by large-scale physiological adaptations, apparently including altered gene expression.
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