Bacteriology wk 1

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  3. Hemolytic patterns
    • alpha: partial hemolysis, "greening" due to biliverdin
    • beta: complete hemolysis, clearing
    • gamma: non-hemolytic
  4. types of serological typing
    • Lipopolysaccharide side chain ("O" antigen)
    • Capsular antigen ("K" antigen) 
    • flagellar antigen ("H" antigen)
    • other cell surface proteins (like M protein of streptococci)
  5. gram staining
    all cells stain purple, decolorizer (alcohol or acetone) removes LPS but not peptidoglycan, so safranin colors gram-, but gram+ remains crystal violet
  6. acid fast stain
    decolorizer (acid alcohol) takes away non-acid fast so acid-fast are red/carbolfuchsin, non are methylene blue
  7. peptidoglycan
    thick cell wall of gram + bacteria that traps pigment (gram - has thin layer).  Sugar backbone with interlocking peptides.  Lysozymes break sugar backbone to make wall fall apart
  8. gram negative cell wall
    • thin layer of peptidoglycan in periplasmic space, outer membrane is phospholipids paired with lipopolysaccharides.  
    • lysozymes can't cross this lipid bilayer while it's intact
  9. acid fast cell envelope
    • mycobacterium (gram+)
    • lipids on outside, mycotic acid, peptidoglycan on the bottom.  Waxy cell wall, heat drives stain in.
  10. mollicutes and anaplasmataceae
    bacteria with no cell wall.  Take cholesterol from host to use.  No peptidoglycan so stain gram-, but don't have LPS wall either.
  11. flagella
    • Flagellin protein, used for motility (chemotaxis).  
    • "H" antigen (antigenic)
    • surface arrangement can vary (0, 1, 2, to all over surface)
  12. pili (fibriae)
    • promote adherence
    • bacteria to bacteria or bacteria to host cell
    • "F" antigen
  13. capsule
    • polysaccharide or protein
    • antigenic -- "K" antigen
    • slime layer = loosely adherent capsule
    • often antiphagocytic
    • barrier to toxic hydrophobic (detergents)
    • synthesis is very energy expensive, only make when necessary
  14. spores/endospores
    • develop inside mother cell under nutrient-limited conditions.  Dormant, no metabolic activity, highly resistant to environment.  
    • Germinate once reach appropriate environment.  Dense core with LOTS of layers.
  15. Fastidious bacteria
    • require organic molecules, not just simple building blocks for synthesis of major cellular constituents.  
    • Can use to diagnose (plates without basic requirements, transmission through environment possible or just host-host)
  16. microaerophile
    • prefer low oxygen levels, can grow without O2
    • campylobacter fetus
  17. indifferent/aerotolerant anaerobe
    • ferments in the presence of O2
    • strep equii
  18. facultative anaerobe
    • respires with O2, ferments without
    • E. coli, staph aureus
  19. anaerobe (strict)
    • killed by O2, ferments without it.  
    • Clostridium tetani, fusobacterium necrophorum
  20. aerobe (strict)
    • requires O2, can't ferment
    • mycobacterium bovis, bacillus anthracis
  21. campylobacter temperature
    likes 45C -- likes it hot!
  22. listeria temperature
    likes 4C, likes it cold (refrigerator okay)
  23. Plasmid
    • autonomously replicating extrachromosomal molecules
    • not required for viability
    • often encode virulence (TNFalpha inhibition, phagocytosis inhibition) or abx resistence
    • insert via transposition (sometimes)
  24. bacteriophage conversion
    • lytic: lyse cell
    • lysogeny: integration, cell replication making a "prophage".  Integrase integrates into chromosomes, stay forever in generations.  Could turn lytic.  (botulism)
  25. pathogenicity islands
    • carry many virulence genes
    • present in pathogenic strains, messed up or absent in others.
    • HUGE, different C+G than host
    • associate with tRNA genes or insertion sequences
    • often have cryptic mobility genes
Card Set
Bacteriology wk 1
IV wk1