lab diagnosis of Pseudomonas sp.

1. Pseudomonas
Lab 8
Prepared by
Samira Fattah
Assis. Lec.
College of health sciences-HMU

2. • Medically important Pseudomonas:
P. aeruginosa.
• present in small numbers in the normal intestine
flora and on the skin.
• Commonly present in moist environments in
hospitals.
• It is primarily a nosocomial pathogen.

3. General character
• Gram-negative rods.
• Motile by polar flagella.
• aerobics.
• Grow well at 42⁰C.
• Non-lactose fermenting

4. Pigment production
• can produce pigments, such as:
• Pyocyanine (blue-green)
• Pyoverdin (fluorescent yellow- greenish pigment)
• Pyorubrin (red)
• Pyomelanin (brown)

5. Laboratory diagnosis
Specimen:
• Wound discharge
• sputum
• Blood
• Urine
• CSF

6. Microscopy
-Gram stain
Gram negative rod
undistinguished from
enerobacteriaceae.

7. On Culture media

8. Culture character
• Form smooth and round colonies.
• Fluorescent greenish colour.
• production of fruity odor (grape-like) .
• Inability to ferment lactose.

9. On nutrient agar
• Colonies are smooth, large, translucent
• Greenish blue diffusible pigment

10. On blood agar
• Grayish colonies
• Many are haemolytic
(beta hemolysis).
This picture shows Pseudomonas aeruginosa
(on the right) and Shigella dysenteriae (on the
left) in blood agar.

11. On MacConkey agar
• Non-lactose fermenting (colourless colonies)

12. On EMB
• Non lactose fermenting

13. Pigment production on Cetrimide agar
• is a type of agar used for the selective isolation of
the gram-negative bacterium, Pseudomonas aeruginosa.
• As the name suggests, it contains cetrimide, which is the
selective agent against alternate microbial flora.

14. • Cetrimide also enhances the production
of Pseudomonas pigments such as pyocyanin and fluorescein,
which show a characteristic blue-green and yellow-green
colour, respectively.

16. Pseudomonas aeruginosa fluorescence under UV illumination

18. Oxidase test
• Oxidase positive
Catalase test
• Catalase positive

19. API20E test