â– LECTURE OVERVIEW: Pseudomonas aeruginosa is a versatile, opportunistic Gram-negative pathogen notorious for causing severe healthcare-associated infections.
â– IDENTIFYING PROPERTIES:
1. Gram Stain & Shape: Gram-negative, thin, aerobiotic rod.
2. Enzyme Profile: Oxidase-positive and catalase-positive.
3. Sugar Fermentation: Non-lactose fermenting on MacConkey agar (forming clear colonies), and is highly motile via its polar flagellum.
4. Pigment Synthesis: Produces Pyocyanin (a blue-green pigment generating reactive oxygen species) and Pyoverdine (a yellow-green fluorescent siderophore).
5. Sweet Aroma: Synthesizes aminoacetophenone, yielding a characteristic sweet, grape-like and fruity odor in culture and infected wounds.
â– SURGICAL LANDMARKS & ANATOMICAL BOUNDARIES:
Intraoperative access requires meticulous dissection along defined tissue planes. Avoid excessive traction near neurovascular bundles and look for key bony landmarks or fascial reflections to secure margins.
â– HISTOCHEMICAL & SPECIAL STAIN ANALYSIS:
Tissue examination is enhanced by specialized dyes and immunophenotypic markers that target cellular structure with remarkable specificity.
[HY-BOARD-1333]
🌟 Dynamic Clinical Key:
A major source of hospital-acquired infections, particularly ventilator-associated pneumonia in ICU patients, ecthyma gangrenosum in neutropenic patients, malignant otitis externa in diabetics, hot tub folliculitis, and chronic pulmonary infections in cystic fibrosis patients. Never divide or ligate any vessel before clearly isolating and confirming its origin and termination. Always cross-reference histochemical stains with structural boundaries on the biopsy.