Changes

*Causes opportunistic infections requiring predisposing factors

*Pathogenesis:

 

**Grows on few nutrients and can survive certain disinfectants

**Toxins and enzymes such as exotoxin A, phospholipase C and proteases allow tissue invasion and damage

''Pseudomonas aeruginosa'' is a species of the ''[[Pseudomonas species - Overview|pseudomonas]]'' genus. It causes opportunistic infections requiring predisposing factors.

**Elastase damages elastin in lung parenchyma and blood vessel walls

 

**Attachment to host cells via fimbrae

==Pathogenesis==

**Resists phagocytosis and complement via its LPS

''P.aeruginosa'' grows on few nutrients and can survive certain disinfectants. The bacteria has toxins and enzymes such as exotoxin A, phospholipase C and proteases that allow tissue invasion and damage. Elastase damages elastin in lung parenchyma and blood vessel walls. ''P.aeruginosa'' attaches to host cells via fimbrae and resists phagocytosis and complement via its LPS. It obtains iron from tissues.

**Obtains iron from tissues

''P.aeruginosa'' causes haemorrhagic pneumonia and septicaemia in mink with 50% mortality via a [[Haemostasis - Pathology#Secondary Thrombocytopenic Disease|secondary thrombocytopenic disease]].

**Haemorrhagic pneumonia and septicaemia in mink with 50% mortality via a [[Haemostasis - Pathology#Secondary Thrombocytopenic Disease|secondary thrombocytopenic disease]]

**Bovine mastitis associated with contaminated water used for washing udders; also metritis, pneumonia, dermatitis and enteritis in cattle

''P.aeruginosa'' causes[[Mastitis|Bovine mastitis]] associated with contaminated water used for washing udders; also [[Metritis]], pneumonia, dermatitis and [[:Category:Intestine - Inflammatory Pathology|enteritis]] in cattle.

**[[Bacterial skin infections - Pathology#Ovine fleece rot|Ovine fleece rot]] - suppurative dermatitis after penetration of water into fleece; wool discoloured by pyocyanin pigment; also mastitis, pneumonia, otitis media

**Necrotic stomatitis in captive reptiles

''P.aeruginosa'' causes [[Bacterial skin infections - Pathology#Ovine fleece rot|Ovine fleece rot]], also mastitis, pneumonia and otitis media.

**Respiratory infections and otitis in pigs

**Genital tract infections, pneumonia, ulcerative keratitis in horses

''P.aeruginosa'' causes necrotic stomatitis in captive reptiles.

**Otitis externa, cystitis, pneumonia, ulcerative keratitis in dogs and cats

**Causes [[Bacterial skin infections - Pathology#Deep pyoderma|deep pyoderma]]

''P.aeruginosa'' causes [[Diseases of the conducting airways|respiratory infections]] and otitis in pigs.

*Diagnosis:  

''P.aeruginosa'' causes genital tract infections, pneumonia and ulcerative keratitis in horses.

''P.aeruginosa'' causes [[Otitis Externa - Small Animal|otitis externa]], [[Cystitis|cystitis]], pneumonia and ulcerative keratitis in dogs and cats.

It can also cause [[Bacterial skin infections - Pathology#Deep pyoderma|deep pyoderma]] in all species.

 

Diagnosis:  

**Specimens should include pus, respiratory aspirates, mid-stream urine and ear swabs

**Specimens should include pus, respiratory aspirates, mid-stream urine and ear swabs

**Identify colonies on blood and MacConkey agar

**Identify colonies on blood and MacConkey agar