Bacterial pathogenesis of infeciotn Flashcards
What proportion of people carry NEISSERIA MENINGITIDIS?
1/5
Gram type of neisseria meningitidis?
-ve
Respiration of neisseria meningitidis?
Aerobic–> CO2 enhances growth
Does neisseria meningitidis grow extracellularly or intracellularly?
Extracellular
neisseria meningitidis features?
Diplococci, “coffee/kidney bean” appearance
Diplococci meaning?
Always two of the bacteria connected to each other
How does neisseria meningitidis attach to a mucosal layer?
Via pili
Are neisseria meningitidis motile?
No–> no flagellum
Capsule of neisseria meningitidis?
Made out of polysaccharides–> sugar coated
Role of polysaccharide layer in neisseria meningitidis?
Protection from the immune system
What endotoxin do neisseria meningitidis make?
Lipooligosaccharide (LOS)
Where on neisseria meningitidis is LOS produced?
Outer membrane, and is shed
What causes sepsis/septic shock?
Shedding excessive amounts of LOS toxin
What does shedding of LOS stimulate?
Cytokine release–> TNFalpha, IL1
What can TNF alpha and IL6 release lead to?
Hypotension and septic shock
Why do some bacteria stimulate the immune system?
Uses up the immune system–> exhausts it
What can neisseria meningitidis cause in certain conditions?
Meningitis
Why is meningitis called meningitis?
When the bacteria enters the brain it causes shrinkage of the meninges
Mortality rate of meningitis?
Quite high if not treated
Symptoms of meningitis?
Septicemia w/ multiple organ involved including CNS
What causes damage in meningitis?
Intravascular coagulation, shock, fever
What builds up in blood and tissues as part of meningitis?
Endotoxin
What is septicemia?
Bacteria entering the blood stream and trigger sepsis
What is sepsis?
Inflammatory response as a result of septicemia causes organ damage
