Pseudomonas

Question 1

Pseudomonas characteristic

Answer 1

● Gram -ve long bacilli

● Oxidase +ve

● Strict Aerobe

● Motile

● Cannot ferment glucose

● 2nd most common cause of nosocomial infections (after Staph.

Aureus)

Question 2

➢Virulence Factors Pseudomonas

Answer 2

1. Slime layer (glycocalyx) )mcqs ل( overproduction of alginate
2. Toxins:

● Endotoxin: Causes septic shock

● Exotoxin:
A&raquo_space;ADP Ribosylation of eF-II inhibiting protein synthesis,
S&laquo_space;damage Cytoskeleton
U» Cell Membrane

3. Enzymes
4. Type III secretion system (molecular syringe):
5. Pigments:

a. Pyoverdine (fluorescein): a yellow-green pigment

b. Pyocyanin: color blue

Question 3

➢Clinical Manifestations of pseudomonas

Answer 3

1. Pneumonia with Cystic Fibrosis
2. Otitis externa

Presentation of the case:

● Inflammation of external ear

● Discharge with green or blue color

● Types: Mild -> Swimmers.. Malignant -> Diabetes

3.Osteochondritis (pain and swelling)#

4.Endophthalmitis (contact lens users)#

5.Ecthyma Gangrenosum.*

6.Wound infections (specially burns)

7.Cellulitis

8.UTI Either:

● Cystitis ● Pyelonephritis

9.Meningitis

Question 4

➢ Transmission pseudomonas

Answer 4

1. In hospitals
2. By ventilators
3. By tap water

Question 5

➢ Diagnosis pseudomonas

Answer 5

1. Specimen collection Pneumonia - Sputum Wound Infection - Wound Swap Otitis externa - Ear discharge
2. Microscopy Gram (-ve) bacilli with flagella
3. Culture

a. Nutrient agar (Only for Pseudomonas)

● Blue to green color

● Grape-like smell (fruity smell) due to presence of (2-amino acetophenone)

b. MacConkey agar Pale(colorless)

4. Biochemical tests pSeudoMOnas - S,M,O

● Sugar fermentation test (-ve)

● Motility test (+ve)

● Oxidase (+ve)

Question 6

➢Treatment of pseudomonas

Answer 6

cell wall inhibitors
1. Penicillin family:

● Carboxy-penicillin (Tecracillin)

● Uredo-penicillin (Pepracillin)

2. Cephalosporins family:

● 3rd generation (Cephtazdime + Cephoprazone)

● 4th generation (Cefepime)

3. Carbapenem family: Meropenem or Imipenem
4. Monobactam: Azteronam

Protein synthesis inhibitors:
5. Aminoglycosides: Gentamicin or Topramycin

DNA synthesis inhibitors:
6. Fluoroquinolones: Ciprofloxacin

Cell membrane inhibitors:
7. Polymyxins: Polymyxin B or E

بصورة عامة

Tobramycin + Polymyxin