Pseudomonas CF L6 Flashcards
What is the physical characteristic of Pseudomonas Aeruginosa?
Gram -
Highly motile
Rod Shaped Bacteria
What does Pseudomonas Aeruginosa use for respiration and oxidative metabolism?
Oxygen
What are some characteristic of Pseudomonas Aeruginosa?
- Binds tightly to lung epithelium
- Can grow anaerobically by fermentation
- Produces extracellular polysaccharide (mucoidy)
- PRIMARY CAUSE OF DEATH FOR CF PATIENTS
Define characteristics of Gram +
- Thick PG layer
- No Outer Membrane
- No lipopolypeptide
Define charateristics of Gram -
- Thin PG layer
- Outer membrane
- Lipopolypeptide
What consists of the inner leaflet of the outer membrane and what is its function?
Phospholipids
-Barrier to hydrophilic compounds
What consists of the outer leaflet of the outer membrane and what is its function?
Lipopolysaccharide
- Negatively charged
- Resistant to detergents and other hydrophobic molecules
What is on the outer membrane that allows entry of small molecules?
Pores
-let in small hydrophilic molecules
What is LPS?
- AKA: endotoxin
- Potent antigen
What does LPS cause? (2)
- Strong adaptive immune response
2. Strong innate immune response
With LPS, what is an example of a strong adaptive immune response?
Stereotyping strains like E. coli O157:H7
With LPS, what is an example of a strong innate immune response?
- Cytokine production
- Septic shock
What is flagellum?
Most common agent of motility
What is motility?
Allows bacteria to penetrate mucous layer
What is chemotaxis?
-movement towards food or away
from poisons.
-Specific receptors on
bacterial cell surface direct motility.
How does a bacterium know when and where it should swim?
Bacterial chemotaxis and motility are controlled by a 2-component regulatory system
What consists of the two component regulatory system?
- Sensor histadine kinase (SHK)
2. Resonse regulator
What are adhesins?
Bind to sugars and proteins on the host cell surface
Where are adhesins found?
Microbial cell surface
T/F Adhesins can be specific
True
Name some potential adhesive structures for bacteria
- Pili
- Flagella
- Capsules
What are capsules?
- Loose network of polymers surrounding cells
- Polysaccharide or protein or both
What is the role of the capsule?
- Adherence
- Protection against phagocytosis
- Protection against some environmental stresses
Name the important encapsulated pathogens (4)
- Streptococcus Pneumonia
- Haemophilus influenza
- Neisseria meningitidis
- Pseudomonas aeruginosa
What is alginate?
- It produces the mucoidy that CF patients have
- A protective capsule
What does the production of alginate depend on?
AlgU, a sigma factor
State process of AlgU
- AlgU normally held in an inactive state by interaction with MucA
- When cell senses cell wall stress, MucA is degraded by proteases –> activated AlgU
- AlgU directs transcription of the Alginate gene
What do CF patients have a lot of alginate?
INACTIVE MUCA
What are the signaling compouns?
- Acylated homoserine lactones (Gram - )
2. Peptides (Gram +)
