This document discusses the bacterium Pseudomonas aeruginosa. It is a gram-negative rod that is commonly found in hospitals and moist environments. It can produce pigments like pyocyanin and pyoverdin. Laboratory diagnosis of P. aeruginosa involves examining samples from wounds, sputum, blood, urine or CSF under microscopy and culturing on different media like blood agar, MacConkey agar, and Cetrimide agar. P. aeruginosa is oxidase and catalase positive and shows characteristic fluorescence under UV light.

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