Anaerobic Bacteria I

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Anaerobic Bacteria I
2013-02-12 11:02:47
micro exam

from ppt
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  1. obligate aerobes
    —Absolute requirement for O2 to grow
  2. Obligate anaerobes
    • —Grow only under conditions of high reducing intensity (anaerobic system w/ 0% O2)
    • —O2  is toxic
  3. ¢Facultative anaerobes
    —Grow under aerobic or anaerobic conditions
  4. Microaerophiles
    • —Grow best under lower O2 intensity (anaerobic system w/ 0% O2 or in 10% CO2, 85% N2, 5% O2
    • —Higher O2 tensions may be inhibitory (no growth in CO2 incubator with 5% CO2, 15% O2 or in ambient air with about 21% O2
  5. ¢Aerotolerant anaerobes
    • —Anaerobes that are not killed by exposure to O2
    • Best growth in anaerobic system w/ 0% O2
    • Moderate growth in 10% CO2, 85% N2, 5% o2
    • Less growth in CO2 incubator, 5% CO2, 15% O2
    • Less growth in ambient air about 21% O2
  6. Name a species that is anaerobic, Gram pos, bacilli, and a spore former.  Name 6 organisms in this group.
    • ¢Clostridium spp
    • 1.C. perfringens
    • 2.C. difficile
    • 3. C. botulinum
    • 4.C. histolyticum
    • 5.C. septicum
    • 6.C. tetani
  7. List 6 species that are anaerobic, Gram pos, bacilli, and non-spore formers.
    • 1.Actinomyces spp
    • 2.Bifidobacterium spp
    • 3.Eubacterium spp
    • 4.Lactobacillus spp
    • 5.Mobiluncus spp
    • 6.Propionibacterium spp
  8. Name a species the is anaerobic, gram pos cocci, and a non-spore former. Name 2 organisms in this species.
    • ¢Peptostreptococcus spp
    • 1.P. anaerobius
    • 2.P. asaccharolyticus
  9. Name 1 organism and 1 species that are anaerobic and gram pos cocci.
    • —Staphylococcus saccharolyticus
    • —Streptococcus spp
  10. Name 6 species that are anaerobic Gram neg bacilli.
    • —1.Bacteroides
    • —2.Bilophila
    • —3.Campylobacter
    • —4.Fusobacterium
    • 5.Porphyromonas
    • 6.Prevotella
  11. Name 3 anaerobic Fusobacterium species.
    • ¢F. mortiferum
    • ¢F. necrophorum
    • ¢F. nucleatum
  12. Name an important anaerobic Porphyromonas organism.
    ¢P. asaccharolytica
  13. Name 2 important anaerobic Prevotella organisms.
    • ¢P. intermedia
    • ¢P. melaninogenica
  14. Name 2 species of anaerobic gram neg cocci.
    • —Veillonella 
    • —Megasphaera spp.
  15. Strict anaerobes die within _____ minutes of _______ exposure.
    • 10
    • O2
  16. Name 3 enzymes that moderate anaerobes can use to protect themselves from the toxic effects of O2 production.  Can anaerobes that do not produce these enzymes still have a high level of virulence?
    • catalase
    • superoxide dismutase
    • peroxidase
    • yes
  17. What do catalase and peroxidase break down?
    ¢H2O2 to H2O and molecular O2
  18. Catalase is found in what type of bacteria?
    Peroxidase is found in several ________ anaerobes.
    • aerobic or facultative bacteria
    • —Peroxidase found in several aerotolerant anaerobes
  19. What enzyme converts superoxide radicals to H2O2 and molecular O2?
    Superoxide dismutase
  20. Describe Phase 1 of the sensitivity of anaerobes to O2.
    • —When anaerobes are placed into an O2-containing atmosphere, electrons normally available for cellular metabolic processes are diverted to the reduction of molecular O2.
    • —Metabolic processes stop which leads to a complete cessation of growth.—
    • This is a bacteriostatic effect, which is reversible up until the time of Phase 2.