28 Matching Annotations
  1. Aug 2020
    1. Qu, J., Cai, Z., Liu, Y., Duan, X., Han, S., Zhu, Y., Jiang, Z., Zhang, Y., Zhuo, C., Liu, Y., Liu, Y., Liu, L., & Yang, L. (2020). Persistent bacterial coinfection of a COVID-19 patient caused by a genetically adapted Pseudomonas aeruginosa chronic colonizer. BioRxiv, 2020.08.05.238998. https://doi.org/10.1101/2020.08.05.238998

  2. Apr 2020
    1. An effective therapy to combat biofilm should include effective removal of the biofilm, antimicrobial eradication of bacteria/organisms, and prevention of biofilm recurrence, and these treatment options may need to be repeated multiple times to achieve effective therapy.
    2. A few products have been suggested to control and remove biofilms, such as surfactant and some wound cleansing formulas. In addition, topical broad-spectrum antimicrobials such as silver, iodine, honey, and others have been suggested to aid in the treatment of biofilms.
    3. The best method of treating wounds with biofilms is not well defined. It is believed that frequent debridement to mechanically remove the biofilm remains to be the best method of treatment. The frequency of debridement is not well defined, although a weekly debridement has been suggested to improve healing. More than one method of debridement might be needed in wounds resistant to healing.
    4. The presence of biofilms leads to delayed wound healing by stimulating chronic inflammation in the wound.
    5. Furthermore, it rapidly recovers form mechanical disruption, such as debridement, within 24 hours
    6. Bacterial species develops the extracellular polymeric substances (EPS) and resistance to disinfectants, antiseptics, and antibiotics in 6 to 12 hours. The biofilm then develops into mature colonies in 2 to 4 days
    7. In some cases, the biofilm allows bacteria to become quiescent and thus become less sensitive to antimicrobials that typically affect dividing bacterial cells.
    8. Bacteria will then begin to exhibit phenotypic and genotypic plurality: the former allows bacteria to adapt to different growth conditions such as nutrient availability, pH, and oxidizing potential within the biofilm, while the latter allows for virulence and bacterial resistance to drugs.
    9. The presence of biofilms protects bacteria from the host defenses.
    10. Once a biofilm colony forms, it will continuously shed bacteria to uncolonized areas, causing more biofilm colonies to form.
    11. Lastly, in the third stage, organisms secrete a surrounding protective matrix called the extracellular polymeric substance (EPS).
    12. This stage depends on a microbial-to-microbial cell communication system, called quorum sensing, in which small signaling molecules are released and gradually increase in concentration. The signaling molecules regulate gene expression and help form the biofilm.
    13. This stage depends on a microbial-to-microbial cell communication system, called quorum sensing, in which small signaling molecules are released and gradually increase in concentration.
    14. The second stage is the permanent adhesion or maturation stage in which the organisms permanently attach, proliferate, and maturate in the wound surface.
    15. Biofilms are formed in three stages. The first stage—the reversible bacterial adhesion stage—is formed by adhesion of bacteria to the surface of the wound
    16. Biofilm is the term used for the bacterial growth on a chronic wound that is encapsulated by a protective layer made up of the host and bacterial proteins. Bjarnsholt et al have suggested a simplified definition of the biofilm as “an aggregate of bacteria tolerant to treatment and the host defense.”
    17. Biofilms lead to a chronic inflammatory process that will interfere with healing
  3. Oct 2019
    1. observations are consistent with a previous report showing that AHLs preferentially partition to the biofilm, reaching concentrations 600-fold in excess of the signal concentration in the surrounding bulk liquid medium
    1. with pegs of polystyrene microtiter lid (catalog no. 445497; Nunc TSP system) immersed for bacterial biofilm formation
    1. Planktonic stationary-phase cells were used in dose-response killing experiments, for a better comparison to biofilms
    1. it may be possible to tag specific organisms and use these as monitor systems to estimate local chemical composition directly in the biofilms
  4. Sep 2019
  5. Jul 2019
    1. Surprisingly, quorum sensing promotes V. cholerae virulence factor expression and biofilm formation at low cell density and represses these traits at high cell density

      Vibrio cholerae QS (high density) inhibits biofilm and virulence

    2. Quorum sensing is essential for chronic P. aeruginosa respiratory infection because it controls adhesion, biofilm formation, and virulence factor expression

      Psuedomonas aeruginosa QS induces biofilm formation

  6. Jun 2019
    1. response to antimicrobial agents can greatly vary, depending on the location of a particular cell within a biofilm community
  7. Apr 2019
    1. exopolysaccharide > flagella >N-acyl-homoserine lactones (AHLs) signaling molecules > extracellular protein > swarming motility