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, 19:41, 14 May 2010
*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
**Elastase damages elastin in lung parenchyma and blood vessel walls
**Attachment to host cells via fimbrae
**Resists phagocytosis and complement via its LPS
**Obtains iron from tissues
*Clinical infections:
**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
**[[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
**Respiratory infections and otitis in pigs
**Genital tract infections, pneumonia, ulcerative keratitis in horses
**Otitis externa, cystitis, pneumonia, ulcerative keratitis in dogs and cats
**Causes [[Bacterial skin infections - Pathology#Deep pyoderma|deep pyoderma]]
*Diagnosis:
**Specimens should include pus, respiratory aspirates, mid-stream urine and ear swabs
**Identify colonies on blood and MacConkey agar
**Oxidative not fermentative
**Only grow in aerobic conditions
**Produces diffusable pigments including pyocyanin, a green pigment, and fluorescine
**Grow on MacConkey agar; colonies have a fruity odour; lactose negative, pale colonies on MacConkey
*Treatment:
**Multiple antibiotic resistance mediated by large plasmids carrying resistance genes and also chromosomal genes and mutations
**Gentamicin or tobramycin with carbenicillin or ticarcillin, as well as polymyxin B are effective
[[Category:Pseudomonas_and_Burkholderia_species]]