Pseudomonad

• Morphology and staining

  • Gram-negative rods (1-3 × 0.5) µm, individual or short chain
  • Non-spore forming, non-capsulated
  • Motile except Burkholderia mallei

  
• Cultural characteristics

  • Obligate aerobic
  • Grow at 37 °C and in range of ( 3-43 ) °C
  • Growth on non-enriched media
  • Diffusible pigments are produced, like pyocyanine and fluorescein
  • Grow on MacConkey agar, dark or colourless colonies, non lactose fermented
  • Blood haemolysis
  • Colonies odour, grape like or musty

  
• Selective media

  • Cetrimide Agar is used as a selective medium for the isolation of Pseudomonas aeruginosa from pus, sputum and drains etc. Also used for determining the ability of an organism to produce fluorescein and pyocyanin
  • Pseudomonas agar

  
• Pyocyanin in nutrient broth
• Biochemical tests


  • Biochemical for differential between B. pseudomallei and B. mallei

  
• Diseases


  • Mastitis, Metritis (Cattle - P. aeruginosa)
  • Mastitis, Pneumonia (Sheep and Cattle)
  • Metritis, ulcerative keratitis (Horse)
  • Otitis externa, Cystitis, Pneumonia (Dogs & Cats)
  • Otitis media, urinary tract infection, wounds infection (Human)
• Diseases


  • Glanders (Horses - B. mallei)
  • Septicaemia (Other animal, Human)
  • Melioidosis acute form or chronic form (Horses, cattle, sheep, goats, dogs - B. pseudomallei)
• Diagnosis

  • History and clinical signs
  • Isolation of bacteria, pigmentation
  • β-haemolysis on blood agar
  • Growth on MacConkey agar