head picture
pseudomonas aeruginosa pigment

Pseudomonas aeruginosa

Pseudomonas aeruginosa on tryptic soy agar. Cultivation 24 hours at 37°C + 24 h. at room temperature.

  • Basic shape of colonies: circular
  • Elevation (cross sectional shape of the colony): raised
  • Margin: undulate
  • Pigmet production: pyocyanin (blue-green)
Compare P.aeruginosa with S.aureus (yellow colony in detail)
  • Basic shape of colony: circular
  • Elevation: convex
  • Margin: entire
  • Pigmet production: staphyloxanthin(yellow)

Pseudomonas aeruginosa is often preliminarily identified by its typical odor in vitro. It resembles (in some strains) blooming Philadelphus coronarius (Sweet Mock-orange, English Dogwood), a species of deciduous shrubs in the genus Philadelphus, native to Southern Europe.
Pseudomonas aeruginosa is the most common cause of infections of burn injuries and of the outer ear (otitis externa), and is the most frequent colonizer of medical devices (e.g., catheters). Pseudomonas can, in rare circumstances, cause community-acquired pneumonias, as well as ventilator-associated pneumonias, being one of the most common agents isolated in several studies.

P. aeruginosa is naturally resistant to a large range of antibiotics and may demonstrate additional resistance after unsuccessful treatment, in particular, through modification of a porin. It should usually be possible to guide treatment according to laboratory sensitivities, rather than choosing an antibiotic empirically.