SK320, Unit 5, Bacteria

  1. A-B Model
    Model of exotoxin structure where A and B represent the different subunits. A causes the toxic effect, B binds to allow for entry.
  2. Acid-fast
    A functional category of bacteria defined by cell wall composition and hence reaction to staining techniques. Mycobacteria and acid-fast.
  3. Adhensins
    Protein or polysaccharide molecules on viruses and bacteria that bind to specific receptor molecules on host cells.
  4. Antitoxins
    Antibodies that bind to toxins and are able to neutralise them.
  5. Axial fibrils
    Flagella of some spirochaetes, anchored to the bacterium at either end; they move the bacterium with a characteristic corkscrew motion
  6. Bactericidal
    The action of chemicals that kill potentially harmful bacteria in the environment or on the body surface.
  7. Bacteriostatic
    The action of chemicals that prevent bacteria from replicating in the environment of on the body surface.
  8. Biofilm
    A colony of bacteria growing as a continuous adherent sheet on the surface of a substrate, typically glass. Found within hospital equipment (HAIs) and the body (the colon).
  9. Biotechnology
    The use of organisms, their parts of processes for the manufacture or production of useful or commercial substances.
  10. Commensal
    The partner in a symbiotic relationship that benefits from food and possibly shelter, whilst the host remains unaffected. Gut biota
  11. Endospores
    Structures formed by Bacilus and Chlostridium that enable them to withstand adverse conditions.
  12. Endotoxins
    A class of bacterial toxins, consisting of components of the Gram-negative bacterial surface.
  13. Exfoliative
    Description of a toxin that causes lysis of the epithelium, and sloughing of skin.
  14. Exotoxins
    Toxins secreted by bacteria, Exotoxins often conform to the A-B model structure.
  15. Fimbriae
    • Fine hair like structures, found mostly on Gram-negative bacteria, involved in adhesion.
    • AKA pili.
  16. Flagella
    Whip-like organelles that protrude from the cell surface, used for movement or feeding.
  17. Glycocalyx
    The fibrous, outermost layer of the surface of some bacteria that can be involved in mediating attachment to the host.
  18. Gram-negative bacteria
    Bacteria that do not retain crystal violet dye in the Gram-staining test.
  19. Gram-positive bacteria
    • Bacteria that stain blue-purple.
    • A thick peptidoglycan layer in the cell wall.
  20. Haemagglutinins
    Surface glycoproteins found on some bacteria/viruses, with the ability to bind to the membranes of red blood cells and cause clumping.
  21. Lipo-arabinomannan
    Glycolipid consisting of a polymer of lipid and the sugars arabinose and mannose, found in the cell walls of Mycobacterium spp.
  22. Lysogeny
    The integration of the phage genome into that of its bacterial host.
  23. Minimum inhibitory concentration (MIC)
    The lowest concentration of an antimicrobial agent that will inhibit the visible growth of a microorganism after an overnight incubation.
  24. Mycolic acid
    The complex branched lipids on the surface of Mycobacterium spp.
  25. Outer membrane
    Found on the exterior of Gram-negative bacteria.
  26. Pathogenicity Islands
    Particular regions in bacterial genomes that encode virulence factors. Found in pathogenic bacteria but not in non-pathogenic strains of the same or related species.
  27. Penicillin
    Group of B(beta)-lactam antibiotics derived from Panicillium fungi.
  28. Peptidoglycan
    Major component of bacterial cell walls. A polymer of high molecular mass.
  29. Periplasmic place
    Space between the outer membrane and the inner (plasma) membrane, either side of the bacterial cell wall.
  30. Pili
    Thin extensions of the bacterial cell wall, with a role in adhesion.
  31. Plasmids
    Small autonomously replicating circles of DNA found in many bacteria; some encode functions that enable their own transfer.
  32. Porins
    A transmembrane complex of lipids and proteins that allows passage of various solutes across the bacterial outer membrane.
  33. Prokaryotes
    Cells lacking a nucleus, mitochondria and other membrane-bound organelles.
  34. Quorum sensing
    Bacterial cell-cell communication, correlated to their population density. Many use this to co-ordinate behaviour.
  35. Selective toxicity
    The targeting of drugs to only affect a particular type of pathogenic organism, to minimise the damage to host cells and commensal organisms.
  36. Serovars
    Group of closely related microorganisms distinguished by a characteristic set of antigens. AKA serotypes.
  37. Sheath
    Outer membrane of spirochaetes, lipid-rich.
  38. Strains
    Types of bacteria or virus within a species that are distinguishable by genotype or phenotype.
  39. Transposons
    Segments of DN that are capable of independently replicating themselves and inserting the copy into a new position within the same or another chromosome/plasmid.
  40. Virulence factors
    Properties of a microbe that determine its virulence, e.g adhesins and exotoxins.
Card Set
SK320, Unit 5, Bacteria
Unit 5, Bacteria