Micro Test 3: Pseudomonas

  1. Genghis Khan of the Microbial World


    Burned patients, cancer patients, children with cystic fibrosis (it is an opportunistic infection)
  2. Does Pseudomonas have flagella?  Os it motile?
    One flagella, motile
  3. Pseudomonas:
    1)  Gram-P or Gram-N?
    2)  Shape?
    3)  Oxidase-P or Oxidase-N?
    4)  Fermenter?
    5)  Aerobic/Anaerobic
    • 1)  Gram-N
    • 2)  Bacillus
    • 3)  Oxidase-P
    • 4) Non-fermenter
    • 5)  Facultative Anaerobe:  Can aspire anaerobically using nitrates
  4. Which bacteria produces a thick slim layer?
  5. What temperatures does Pseudomonas grow at?
    37 and 42 C, but not 4C
  6. What bacteria is resistant to certain disinfectants?  What disinfectants should you use?
    • Pseudomonas
    • Use phenols or gluteraldehydes
  7. Which bacteria grows anaerobically, but must have nitrates?  (So it won't grow anaerobically in a glucose only tube.)  Is this organism Oxidase-P or Oxidase-N?
    • Pseudomonas
    • Oxidase-P
  8. TSI:  Pseudomonas
    Red butt (no nitrates), apple red slant; pseudomonas is NOT a fermenter
  9. Which bacteria has a fruit odor?
  10. Name 3 pigments Pseudomonas produces and what they do.
    • 1.  Fluorescein (chelates iron)- green/yellow pigment
    • 2.  Pyocyanin (converts O2 to O2-)- blue
    • 3. Red and black pigments also possible
  11. What type of pili do Pseudomonas have?
    Type IV Pili
  12. Which of these bacteria have a Type III SS?
  13. How does the LPS from Pseudomonas compare with other LPS?  What can it bind to?
    • A little weaker, but can still cause detrimental effects.
    • Binds to lectin on some mammalian cells.
  14. They Type IV Pili of Pseudomonas has __________ (like GC and Vibrio); the pili and flagella bind to _____ and trigger _____ production.
    • N-methyl-phenylalanine
    • asialo-GM1
    • IL-8
  15. Pseudomonas contains Neuraminidase.  What does this enzyme do?
    GM1 --> asialo-GM1 for binding sites
  16. 1)  What exotoxin does Pseudomonas produce?
    2)  What activates this cell?
    3)  Ribosylates _____ , halting _____ and causing ____
    4)  Does high iron or low iron favor toxin production?
    • 1)  Exotoxin A
    • 2)  Activated by furin (tissue protease) on entry into host cell- activated by cleavage
    • 3)  Ribosylates EF2, halting protein synthesis and causing cell death
    • 4)  Low iron favors toxin production
  17. Name the two types of Exotoxin A produced by Pseudomonas.
    • Exo S
    • Exo U
  18. Mechanism of Action:
    Exo S + Exo T + Exo Y
    • Intracellular growth then apoptosis
    • (Invasive)
  19. Mechanism of Action:
    Exo U + Exo T
    • Cell Lysis
    • (Cytotoxic
  20. Which type of Pseudomonas exotoxin A is cytotoxic?
    Exo U
  21. Which type of Pseudomonas exotoxin A is invasive?
    Exo S
  22. Type III Secretion Systems of P. aeruginosa
    Causes cytoskeletal disruptions and ribosylates many proteins causing less DNA replication and apoptosis.
    Exo S
  23. Type III Secretion Systems of P. aeruginosa:
    Causes cytoskeletal disruptions and ribosylates multiple proteins causing less cell adhesion (blocks macrophage phagocytosis)
    Exo T
  24. Type 3 SS of P. aeruginosa:
    Which two are GTPases?
    Exo S and Exo T
  25. Type 3 SS of P. aeruginosa:
    Phospholipase that quickly kills cells when injected into the cell, strain is virulent.
    Exo U
  26. Type 3 SS of P. aeruginosa:
    An adenyl cyclase activity that disrupts actin and limits phagocytosis; favors toxin production.
    Exo Y
  27. Which two strains of P. aeruginosa are uncommon among cystic fibrosis patients?
    Cytotoxic strains: Exo U and Exo T

    Good Slide w/ flow chart #25
  28. 2 Important Pseudomonas Proteases.
    • PASP:  collagenase
    • LEP:  induces inflamation
  29. Pseudomonas protease that is capable of destroying host defense molecules and elastin of blood vessels (ecthyma gangrenosum)
    Elastase B
  30. Pseudomonase protease that is present in almost all strains.  It is able to destroy host defenses; may correlate with virulence.
    Protease IV
  31. Pseudomonas Proteases:
    1)  Destroy host defense molecules
    2) Destroy ___ (aids bacterial spreading)
    3)  Activate latent host ________ whose activities contribute to tissue damage
    4)  Cleave and activate receptors on cells that lead to _________
    • 3)  MMP (matrix metalloproteinases)
    • 4)  Pro-inflammatory cytokines (inflmmation)
  32. Body fluids contain _____ molecules with lectin-like properties that bind to LPS.  These molecules clump and opsonize bacteria.
  33. Pseudomonas aergunosa's Regulation of Virulence
    Exo Y -> cAMP -> vfr gene -> lasR gene -> Las R protein -> las I gene -> Las I protein -> Homoserine lactone -> goes back to las R gene (autostimulation)

    Homoserine lactone is involved in expression of many proteins involved in virulence
  34. Regulation of Toxic Exoproteins:
    Staph aureus:  _____
    P. aeruginosa:---
    When do they bind/poison?
    • SA= octopeptide buildup
    • Pa= homoserine lactone build-up

    Bind early, poison late (bind -> replicate -> poison -> spread)
  35. Once Pseudomonas is in the bloodstream, it activates?
  36. Once Pseudomonas builds-up, what host defenses do the proteases destroy?
    • Complement, Ab = opsonization
    • Cytokines = phagocytic killing
  37. Most promising protein for a Pseudomonas vaccine?
    This protein induces ___ response which results in a strong chemotactic event that attracts PMN to kill the bacteria.
    • PopB protein
    • IL17
  38. Which protein binds to host cells Type II SS and prevents bacteria's protein transport; thereby, stopping infections?  Also a good vaccine candidate.
    PerV protein
  39. Which protein helps form por for protein entry into mammalian cells?  It may be good to use in conjucntion with PerV for P. aeruginosa vaccine.
  40. Multiple infections of Pseudomonas in hospital unit can indicate need for strain _____________.  The best method for this is a new tool, ______, that sequencse the entire genome of the bacterial isolate.
    • source identification
    • rapid sequencing systems
  41. Pseudomonas is difficult to treat because it has intrinsic or extrinsic resistance systems.
  42. Pseudomonas has intrinsic resistance (via B-lactamases) to?
    Penicillin G/V, ampicillin, amoxicillin, first generation sephalosproin, sulfa-trimethoprim, furantoin. 
  43. Pseudomonas does not have intrinsic antibiotic resistance to?
    Carbenapems, Gentamycin
  44. In what direction do genes flow between Pseudomonas and Enterobacteriaceae?
    They can flow in either direction.
  45. Pseudomonas treatment
    • 1)  Beta-Lactam + Aminoglycoside
    •     Tircarcillin + tobramycin
    •      Timentin + tobramycin
    •      Piperacillin + tobramycin
    •      Ceftazidime + tobramycin
    •      Cefepime + amikacin
    • 2) Fluoroquinolone (can be oral)
    •        Ciprofloxacin
    •        Levofloxacin
    •        Moxifloxacin or Gatifloxacin
  46. Pseudomonas aeruginosa causes what 3 outpatient infections?
    • Corneal Infections (keratitis)- usually contact lens associated
    • Otitis Externa- Swimmer's Ear
    • Folliculitis- Hot tub related infection
  47. What are the two leading causes of Pseudomonas aeruginosa infection?
    Burns, pneumonia
  48. What percentage of hospital patients are colonized with P. aeruginosa?  What percentage of all nosocomial infections is this?
    • 50%
    • 15%
  49. Major pseudomonas infections that does not lead to bacteremia (all others lead to bacteremia)
    CF lung (chronic infection)
  50. Chronic pseudomonas in the CF lung is in what form?
  51. Pseudomonas aeruginosa:  Cystic fibrosis
    What 4 virulence factors aid in survival of trachea/lung?
    • Lipase
    • Pyocyanin
    • Proteases
    • Hemolysin
  52. Pseudomonas aeruginosa:  Cystic fibrosis
    What 3 components of the organism bind to the epithelium?
    LPS, pili, flagella
  53. Pseudomonas aeruginosa:  Cystic fibrosis
    Mutant bacterium starts alginate production in high/low salt environment?
    high (only CF patients have high salt concentration)
  54. Name 3 other species of Pseudomonas that cause infections.
    • P. fluorescens
    • P. stutzeri
    • P. putida

    Treat with same antibiotics as for P. aeruginosa
  55. Where is Burkholderia pseudomallei found? 
    How is it transmitted?
    What does it cause?
    • Found in dry areas of SE Asia & Australia.
    • Transmitted by dust (inhalation or wound infection)
    • Causes multiple skin/soft tissue abscesses
  56. Burkholderia pseudomallei:
    Do bacteria remain viable in PMN and macropahges?
    Relapses after dormancy are common.
    How do you treat it?
    • Yes
    • Treat w/ anti-pseudomonas antibiotics
  57. Burkholderia cepacia complex (Bcc):
    1)  Consists of ___ members, which are all _____ organisms
    10, environmental
  58. Most important component of BCC
    B. cenocepacia
  59. One of the scariest things about BCC is that it can ______
    spread among CF patients, more lethal than P. aergunosa in CF patients
  60. Burkholderia can produce very large pili called_____.  These pili bind to _____ and ____
    • cable pili
    • Bind to respiratory cells and protease
  61. Agent of antibiotic-resistant pneumonia in CA or nosocomial infections, can colonize catheters.
    Stenotrophomonas maltophilia
  62. How do you treat Stenotrophomonas maltophilia?
    Timentin or sulfa-trimethoprim
Card Set
Micro Test 3: Pseudomonas
Pseudomonas, Burkholderia, Stenotrophomonas