Pseudomonas

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.

15. Pseudomonas aeruginosa fluorescence under UV illumination

16. Oxidase test Oxidase positive Catalase test Catalase positive

17. API20E test