Lecture 16

Question 1

What are the sources, characteristics

Answer 1

Sources: Pseudomonas aeruginosa is commonly found in soil, water, sinks, drain. It thrives in warm, damp environments with small amounts of organic matter. It can also grow in pharmaceuticals due to its resistance to preservatives.
Characteristics: Gram-negative, Thin rods, Strict aerobe, Mesophilic, Oxidase-positive, Catalase-positive

Question 2

What is the pathogenesis of Pseudomonas aeruginosa?

Answer 2

Pseudomonas aeruginosa is an opportunistic pathogen, typically not harmful to healthy individuals but causing infections in those with weakened immune systems (e.g., cystic fibrosis, AIDS, cancer).

Question 3

What are the stages of infection

Answer 3

Stages of Infection:
Bacterial attachment and colonization: Mediated by pili and mucoid adhesions that bind to human epithelial cells.
Local tissue invasion: Facilitated by the production of various toxins.
Disseminated systemic disease: The infection spreads via the bloodstream.

Question 4

What are the virulence factors of Pseudomonas aeruginosa?

Answer 4

Extracellular proteolytic enzymes: Aid in tissue damage and bacterial spread.
Haemolysins: Lyse red blood cells and contribute to tissue damage.
Endotoxins (LPS): Trigger inflammatory responses leading to sepsis.
Immune evasion: Capsules, slime layers, and protease enzymes help avoid immune system detection.

Question 5

What types of infections are caused by Pseudomonas aeruginosa?

Answer 5

Ear infections
Eye infections
Bone infections
Urinary tract infections
Skin infections