Pseudomonas

Pseudomonas

Pseudomonas is a genus of gammaproteobacteria, belonging to the family pseudomonadaceae containing 191 validly species.

Characteristics of Pseudomonas:

ð  Gram –negative

ð  Rod shaped .

ð  One or more polar flagella, providing motility.

ð  Aerobic.

ð  Non –spore forming .

ð  Don not ferment glucose.

ð  Oxides positive.

ð  Catalase positive.

ð  Produce pigments (pyocyanin.pyvirdin)

ð  Non –invasive.

ð  Opportunistic pathogens.

ð  Fruity odor in culture.

Pathogen city of Pseudomonas:

Pseudomonas species cause infection in hospitalized patients such as-

1. Urinary tract infections, after catheterization.
2. Respiratory tract infection –pneumonia.
3. Wound infection (specially burns)
4. Sepsis.
5. Necrotic skin lesions.
6. Infection of ear –Otitis externa.
7. Corneal infection in contact lens users.

Steps:

1. Specimen collection :

-  Wound swab.

-  Urine

-  Pus.

2. Microscopic examination:

Gram staining: Gram –negative rod shaped bacilli.

3.Isolation & Culture:

- Inoculate the specimen on a plate of blood agar media or Mac Conkey’s agar media.

- Incubate at 37°C  for over night.

- Characteristics colonies are forming like.

=> Bluish colonies for pyoverdin pigment.

=> Greenish colonies for pyoverdin pigment.

=> Dark red colonies for pyorubin pigment.

=> Black colonies for pyomelanin pigment.

4. Biochemical tests:

=> Catalase—Positive

=> Oxidase- positive.

=> H₂S –Negative.

=> Gas-Negative.