Pseudomonas aeruginosa: Disease

Pseudomonas aeruginosa disease 

• Presentation
  • 4 main groups of people affected
    • Exposure to contaminated water of hot tubs/pools
      • Malignant otitis externa (MOE)
        • Severe infection of outer ear tissue exposed to water
        • Presents with severe pain and drainage
        • Untreated conditions can progress to osteomyelitis of skull
      • Rash (“hot tub folliculitis”)
        • infection of hair follicles exposed to contaminated water
        • Itchy, papulopustular rash over trunk and extremities
    • Cystic Fibrosis
      • Pneumonia 
        • Increased viscosity of airway in CF mucus impairs mucociliary escalator to clear bacteria
        • Recurrent respiratory infections with P. aeruginosa, diarrhea/steatorrhea, and failure to thrive are classic
    • Immunocompromised patients
      • Ecthyma gangrenosum
        • Rapidly progressive necrotic lesion that is manifestation of Pseudomonas bacteremia
        • Exotoxins and invasion of bacteria destroy blood vessels and surrounding tissue, causing necrosis
      • Often seen in patients with low absolute neutrophil count (e.g. cancer post-chemo, bone marrow transplant)
    • Indwelling (Foley) urinary catheter
      • UTIs (urinary tract infection)
  • Osteomyelitis may be seen in IV drug users/diabetic patients
  • Corneal ulcers/keratitis may be seen in contact lens wearers
  • Wound infection may be seen in burn victims
• Treatment 
  • Piperacillin, ticarcillin
    • Only some extended spectrum penicillins are effective
  • Ceftazidime, cefepime
    • Note: ceftriaxone is NOT effective
  • Fluoroquinolones (e.g. ciprofloxacin, levofloxacin)
  • Carbapenems (e.g. meropenem, imipenem)
  • Aminoglycosides
  • Monobactams
  • Polymyxins (e.g. polymyxin B, colistin)