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pseudomonias
| Term | Definition |
|---|---|
| Pseudomonas infects | immunocompromised patients with cancer, burn patients, and cystic fibrosis patients |
| lipopolysaccharide (LPS) of P. aeruginosa is | less toxic than other GNRs causing less inflammation and allowing chronic infections |
| P. aeruginosa is | a Gram-negative, rod-shaped, asporogenous, and monoflagellated bacterium with pearlescent appearance and grape-like or tortilla-like odour |
| P. aeruginosa is oxidase | Ox positive |
| P. aeruginosa is citrate | Cit positive |
| P. aeruginosa is L arginine dehydrplase | arg positive |
| Nitrate Reduction | Nit. positive |
| Gas | Gas positive |
| Urease | Ur positive |
| Sulfur | S negative |
| P. aeruginosa grows at what temperature | 42C |
| Most strains of P. aeruginosa produce one or more pigments on Nutrient augar | Pyocyanin (blue-green), Pyoverdine (yellow-green and fluorescent), Pyorubin (red-brown) |
| P. aeruginosa on Blood agar | Colonies are β-hemolytic |
| on Cetrimide agar | Greeninsh yellow colonies develop |
| on McConkey agar | Colourless colonies develop as other non-lactose fermenters |
| P. aeruginosa strains produce TWO distinct types of O antigen (O-Ag): | A band and B band |
| A-band- a common polysaccharide antigen composed | of a homopolymer of d-rhamnose |
| B-band- an O-specific antigen composed | of a heteropolymer of three to five distinct sugars in its repeat units |
| All pathogens | Adhesins ,Flagelum, Pili, Lipopolysaccharide toxins, Alginate capsule (protection from phagocytosis and antibiotics), biofilm formation |
| delivery system used by Pseudomonas is | type III secretion system, which injects toxins into host cell. |
| ExoA,ETA is | “AB exotoxin” that blocks peptide elongation, like diphtheria toxin, and contributes to the dermato-necrosis that occurs in burn wounds, corneal damage in ocular infections, tissue damage in chronic pulmonary infections, (necrotizing bronchopneumonia) |
| Two elastases are | LasA (serine protease) and LasB (zinc metalloprotease) causing lung parenchymal damage and hemorrhagic lesions (ecthyma gangrenosum), also degrade complement components inhibit neutrophil chemotaxis, |
| Chronic Pseudomonas infections are characterized by the formation of | antibodies to LasA and LasB |
| Phospholipase C is | Hemolysin that breaks down phospholipids. Facilitate tissue destruction. You may also see the term, “lecithinase” |
| Pseudomonias is capable of Quorum sensing meaning its | able to turn on genes for biofilm |
| Pseudomonas infection clinical condition | Wounds: GREEN pus or discharge that may have a fruity smell |
| Causes Otitis | externa aka Swimmer's ear primarily in persons with diabetes and elderly patients Also causes chronic otitis media |
| Infections of the eye occur after | initial trauma of the cornea (contact lens abrasion; scratch on eye surface) & exposure to P. aeruginosa in contaminated water corneal ulcers |
| lung infections have | Greenish sputum, Asymptomatic colonization, and infections in CF patients. Tracheobronchitis, to severe necrotizing bronchopneumonia with high mortality rate |
| Ecthyma gangrenosum is a well-recognized but uncommon cutaneous infection classically associated with | P. aeruginosa skin infections where lesions manifest as erythematous vesicles that become hemorrhagic, necrotic, and ulcerated |
| produce biofilms, gel like structures comprised of | rhamnolipids (rhamnose + long lipid chains) and the antioxidant and antibacterial proteins pyocyanin and pyoverdin |
| P. aeruginosa is inherently resistant to many antibiotics, The mutation of porin proteins constitutes the major mechanism of resistance and produces | a number of different β-lactamases, Multi-Drug Efflux Pump shuttles antibiotics out |