Pseudomonas morphology :

• Pseudomonas is slender gram negative
• Motile
• Non capsulated
• Non sporting
• Obligated aerobes
• 1.5-3 micrometre X 0.5 micrometres

[adinserter name=”Block 4″]

[adinserter name=”AMP”

Cultural characteristics :

1. Ordinary media :
   1. Grows well
   2. Large,irregular colony
   3. With distinctive, musty, earthy smell
2. Nutrient media :
   1. Indecent patches with metallic sheen with crystal beneath patch
3. Mckonkey agar :
   1. Non lactose fermenting pale colony
4. Blood agar :
   1. Beta hemolysis
5. nutrient broth
   1. Dense turbidity
   2. With surface pellicles

[adinserter name=”Block 4″]

Pigment production :

1. Pyocyanin :
   1. Bluish green pigment soluble in water chloroform
2. Pyoverdin :
   1. Greenish yellow pigment soluble in water but not in chloroform

Epidemiology :

1. Community acquired :
   1. Suppurative otis res. Tract infection in cystic fibrosis
2. Healthcare acquired :
   1. Infection of wound, bed sores, eye and UT infection

Pathogenicity :

Toxic extracellular products :

• Exotoxin A
• Protease
• Elastase
• Hemolysin
• enterotoxin

Slime layer as capsule, ability to form “Biofilms” promote infection

Biochemical Reaction :

1. Catalase positive
2. Oxidase negative
3. Sugar fermentative
   1. Glucose
   2. No gas only acid
4. Nitrates to nitrites
5. Arginine hydrolase positive

Laboratory Diagnosis :

• Grows readily on oridarinary media
• Easy identification of pigmented strain of bacilli from clinical specimen
• Prompt oxidase reaction and arginine hydrolysis – identification
• Cetrimide agar – selective media – for isolate from faeces and other samples
• Repeated isolation + clinical correction = confirm diagnosis