Pseudomonas Aeruginosa Flashcards
Are they motile? Spore forming?
They are non-motile and nonspore forming
Why they do not belong to the Enterobacteriaceae?
They are oxidase positive and they do not ferment glucose
How are they transmitted?
- In the hospital, nosocomial infections
- From the environment in soil and water like in swimming pool
Which individuals this pathogen affects?
Since it is an opportunistic pathogen, it affects mostly cancer patients, those who have undergone an immunosuppressive therapy either from endogenous source or from the hospital
What are their structural components considered as virulence factors?
Capsule
Pili
LPS
Pyocyanin
From what is composed of the capsule? What is its function?
It is composed of a mucoid exopolysaccharide
It’s inhibits antibiotic killing come on suppressors neutrophil and lymphocyte activity
What’s the function of the pili?
For adhesion
What does the pyocyanin?
It impairs ciliary function, stimulates inflammatory response, mediate tissue damage through production of toxic oxygen radicals i.e. hydrogen peroxide, superoxide, hydroxyl radicals
Which toxins and enzymes are produced by this bacteria?
Exotoxin A Exotoxin S Cytotoxin Elastase Alkaline protease Phospholipase C Rhamnolipid Antibiotic resistance
What is the role of the exotoxin A and S?
The exotoxin A inhibits protein synthesis, produces tissue damage like in skin and cornea, is immunosuppressive
The exotoxin S inhibits protein synthesis and is immunosuppressive
What does the cytotoxin?
It is cytotoxic for eukaryotic membranes e.g. disrupts leukocytes function, produces pulmonary microvascular injury
What does the elastase?
It destroys elastin-containing tissues (e.g. blood vessels, lung tissue, skin), collagen, immunoglobulins and complement factors
What does the alkaline protease?
It destroys tissues, and inactivates interferons and tumor necrosis factor alpha
What is the phospholipase C? What is its function?
It is a heat labile hemolysin
It mediates tissue damage and stimulates inflammatory response
What is the rhamnolipid? What is its function?
It is a heat stable hemolysin
It disrupts lecithin-containing tissue and inhibits pulmonary ciliary activity
Why they are considered as highly invasive?
Because of the important activity of the LPS leading to septic shock and the production of several types of toxins
In which patient the capsule has an important effect?
In patients with cystic fibrosis because they have excess mucus production
Which pigments do they produce?
What is the color of each one?
pyoverdine: green
pyocyanin: blue green
pyorubin: red
pyomelanin: black
To which toxin the exotoxin A is similar?
It is similar to the diphtheria toxin
Where do they cause disease?
Do you what are related the disease manifestations?
They can cause disease in whatever organ they are introduced
Where and how bacteria are introduced
Which organs are affected when bacteria is inserted through a catheter? Respirator? Lumbar puncture? Contact lenses or eye surgery? If it is a burned patient? From swimming pool?
Urinary tract, heart
Lungs leading to pneumonia
Meningitis
Manifestations vary from scarification of the cornea to complete blindness
There is a systemic spread that leads to septic shock that causes death
Otitis externa and can progress in the case of background diseases to a malignant otitis externa
What is the typical skin manifestation that appears during septicemia caused by Pseudomonas only?
Ecthyma gangrenosum
It’s a necrotic skin lesion with erythematous border, nearly black colored without abscess
What are the specimen is they can always from the blood?
Which specimen is taken in the case of pneumonia?
Since after the local infection there is invasiveness and spread
Sputum
Are they gram negative or positive?
Gram negative coccobacilli
