Which species of pseudomonas is the most important?
P. aeruginosa
Where is pseudomonas found?
- Ubiquitous. Not part of the normal flora.
Describe the structure of pseudomonas. Gram stain. Oxidase?
- Motile, straight or slightly curved, G (-). Arranged in pairs or single, obligate anaerobes unless nitrate or arginine present. Yes
What is the colonial morphology of P. aeruginosa? Something characteristic of it?
- Arranged in pairs or single, have green pigmentation and have the characteristic of grapelike odor.
What does pseudomonas has that is useful to differentiate from enterobacteriacea?
- The presence of cytocrome oxidase.
Which strain of Pseudomonas is the most medically relevant species?
P. aeruginosa
What type of delivery system does P. aeruginosa has?
- Type III secretion system
What are the 4 structural components of P. aeruginosa that facilitate adherence, which is critical for establishing infection?
- Flagella, pili, lipopolysaccharide (LPS) and alginate.
What is the most important virulence factor for P. aeruginosa and what does it do?
- Exotoxin A = disrupts protein synthesis. Much like diphtheria toxin but less potent.
What are the two color pigments that P. aeruginosa and combined what characteristic color does it give?
- Blue and yellow-green that gives it a bright light green color.
What does the pyocyanin produced by P. aeruginosa do and what color is it?
- Its an enzyme that catalyses the production of superoxide and hydrogen peroxide, stimulates IL-8 release that attract neutrophils. It is blue.
What does the pyoverdin produced by P. aeruginosa do and what color is it?
.
- It’s a siderophore that binds iron for use in metabolism and regulates the secretion of virulence factors such as exotoxin A. It is yellow-green.
What are the two enzymes that act together to degrade elastin, resulting in damage to elastin-containing tissues and producing the lung parenchymal damage and hemorrhagic lesions (ecthyma gangrenosum) associated w/ disseminated P. aeruginosa infections?
- LasA (serine protease) and LasB (zinc metalloprotease)
What is the reason for the inherit resistant against many antibiotics that P. aeruginosa has?
- It has a mutation of porin proteins.
What are the organs that P. aeruginosa can affect?
- Pulmonary, eye, ear, bacteremia and endocarditis, skin and soft-tissue, UTI, and localized gastrointestinal tract, Nervous, and musculoskeletal system.
What are the clinical manifestations of P. aeruginosa infection in the lungs?
- From asymptomatic colonization to tracheobronchitis to severe necrotizing bronchopneumonia.
What predisposes patients for P. aeruginosa colonization in the lungs?
- History of broadspectrum antibiotics, use of mechanical ventilation equipment. Cystic fibrosis, other chronic lung diseases, or neutropenia.
What is the most recognized skin infection of P. aeruginosa?
- Infections of burn wounds, folliculits (from hot tubs, swimming pools).
What is the most common way of causing UTI by P. aeruginosa?
- Indwelling urinary catheters.
What is the most recognized ear infection of P. aeruginosa?
- External otitis from swimming (Swimmer’s ear)
What is the treatment for P. aeruginosa infection?
- A combination of active antibiotics.
What is the most important pathogen of Moraxella?
- M. catarrhalis.
Describe the structural morphology of M. catarrhalis.
- Strictly aerobic, oxidase-positve, G(-) diplocco.
What do infections of M. catarrhalis cause?
- Common cause of bronchitis and bronchopneumonia (in elderly patients), sinusitis, and otitis (previously healthy people)
-
30 Eneterobacteriaceae61
-
31 VIBRIO AND AEROMONAS30
-
32 CAMPYLOBACTER AND HELICOBACTER20
-
33 Pseudomonas and Moraxella25
-
34 Haemophilus13
-
35 Bordetella12
-
36 Francisella and Brucella16
-
37 Legionella8
-
38 Bartonella7
-
39 Clostridium18
-
40 Actinomyces, Mobiluncusm, Lactobacillus and Propionibacterium.15
-
41 Bacteroides.4
-
42 Treponema, Borrelia, and Leptospira0
