Pseudomonas aeruginosa

Question 1

Habitat (2)

Answer 1

COMMON HUMAN pathogen

MAJOR cause of NOSOCOMIAL infections

Question 2

General characteristics (8)

Answer 2

Gram-negative rods
MOTILE
CAPSULE 
OXIDASE POSITIVE 
OXIDIZES CARBS
DOES NOT FERMENT SUGARS
Grows readily on MACKONKEY AGAR 
Grows in distilled water, lab hot water baths, hot tubs, wet IV tubing, and other water-containing vessels

Question 3

Pathogenesis (3)

Answer 3

1- PILI —> Adherence
2- EXTRACELLULAR PROTEASE, CYTOTOXIN, HEMOLYSINS, PYOCYANINS —> Tissue damage, local invasion, dissemination
3- CAPSULE, ENDOTOXINS, EXOTOXINS (A and S) —> Systemic infection

Question 4

Localized Infections (7)

Answer 4

Eye —> Keratitis, Endopthalmitis
Ear —> External otitis (swimmer’s ear)
Skin —> Wound sepsis, Purulent rashes associated with contaminated whirlpools, swimming pools
UTI —> Catheterization, Instrumentation, Surgery, Renal transplant
Respiratory —> Pneumonia (Bilateral, middle-lobe consolidation)
GI —> Diarrhea, Necrotizing entercolitis
CNS —> Meningitis, Brain abscess

Question 5

Systemic Infections (6)

Answer 5

Bacteremia
Secondary pneumonia
Bone and Joint infections (IV drug users)
Endocarditis (IV drug users, Prosthetic heart valves)
CNS
Skin and Soft Tissue infection (Ecthyema gangrenosum, Abscesses, Cellulitis, Bullae, Necrotizing fasciitis)

Question 6

Resistance

Answer 6

RAPIDLY develops resistance and requires AGGRESSIVE antibiotic therapy

Question 7

Treatment (5)

Answer 7

Ceftazidime
Aminoglycosides
Quinolones e.g. Ciprofloxacin
Piperacillin-tazobactam
Carbapenems- meropenem, imipenem