Pseudomonas aeruginosa

Morphology &Special FeaturesCultural characteristics & Culture mediaVirulent factorsClinical infectionsComplicationsLab DiagnosisTreatment

Slender, Gram negative, actively motile, bacilli. Often piliated Non capsulated, many strains produce mucoid slime layer. Alginate polymers: produced in patients with Cystic fibrosis. Loose capsules are formed /glycocalyx: bacilli protected from host defences. Pigments: Pyocyanin-bluish green phenazine, water soluble, diffusible. Pyorubin: red color Obligate aerobe. Opt: temp: 37c On ordinary media: large, opaque, irregular colonies. Odor: earthy/ mawkish. On Mac conkey agar: Non lactose fermenting colonies On Blood agar : hemolytic /hemodigestion Oxidative only Catalase&oxidase: Positive. String test : negative Reagent in string test: 0.5% sodium deoxycholate.1. Exotoxin-A 2. Proteases3. Elastases 4. Enterotoxin 5. Hemolysins 6. Slime layer acts as capsule in enhancing virulence. 7. Pili- adhesion 8. Lipopolysaccharides9. Ability to form bio film.

Wound infections Infections in patients with burns Surgical site infections/post operative wound infections. Respiratory infections: a.Pneumonia(VAP)b.COPD UTI : Iatrogenic meningitis EndocarditisSepticaemia. Otitis media Diabetic ulcers Pulmonary complications following Tracheostomy. Infections in patients with bed sores/ pressure sores. Conjunctivitis Severe complicated pneumonia in cystic fibrosis patients. Specimen: Pus wound infections. Sputum resp:inf Urine UTIET tubes, secretionsCSF : meningitis Blood : sepsisUtilises sugars only oxidatively, but not fermentative. Citrate : positive TSI K/K (Alkaline slant/alkaline butt)Selective medium : Cetrimide agar for fecal specimens Reduces Nitrates to nitrites and then to gaseous nitrogen. Ceftazidime Cefipime Colistin Polymyxin-B (Specific for pseudomonas infections ) Amikacin