MMI133 Lecture Notes - Lecture 3: Meningococcal Disease, Petechia, Purpura
19 Jun 2018
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Department
Course
Professor
Neisseria meningitidis (Nickname Meningococcus/Meningococci)
●One cause
of meningitis and other meningococcal disease (sepsis)
● Will show as Gram Negative diplococcus
● Over 12 serotypes based on cell capsule polysaccharides, carbohydrates
● Only four sub serotypes
are responsible for epidemic [A (common in Africa),B (common in the
Americas),C W-135]
●Only affects humans
(does not affect animals)
● Spread through droplet transmission
(1 metre away from host body)
Meningitis
● Inflammation of the meninges (dura -> arachnoid -> pia layer)
● Meninges is what protects the brain and spinal cord, along with fluid
● Caused by microbes infecting the cerebrospinal fluid
Virulence and Pathogenicity
● Invades the mucosal membranes (nose/mouth etc)
, followed by the bloodstream
, and then into
the cerebrospinal fluid
● Contains an endotoxin
within the cell wall (lipo-oligo polysaccharide/LOS) which contains lipid A,
causing inflammation
● Endotoxin causes blood clotting
, which leads to hemorrhaging (petechiae, purpura), disseminated
intravascular coagulation/DIC (formation of blood clots in small blood vessels), and shock
Document Summary
Are responsible for epidemic [a (common in africa),b (common in the. Neisseria meningitidis (nickname meningococcus/meningococci) of meningitis and other meningococcal disease (sepsis) Over 12 serotypes based on cell capsule polysaccharides, carbohydrates. Spread through droplet transmission (1 metre away from host body) (does not affect animals) Inflammation of the meninges (dura -> arachnoid -> pia layer) Meninges is what protects the brain and spinal cord, along with fluid. Caused by microbes infecting the cerebrospinal fluid. Invades the mucosal membranes (nose/mouth etc) the cerebrospinal fluid. , and then into within the cell wall (lipo-oligo polysaccharide/los) which contains lipid a, intravascular coagulation/dic (formation of blood clots in small blood vessels), and shock. , which leads to hemorrhaging (petechiae, purpura), disseminated. Is not consumed by white blood cells. The capsule is the most important virulence factor wall (phagocytosis) due to the polysaccharide coating on cell. Increase the amount of white blood cells in spinal fluid. Headaches, stiffness nausea, soreness, coma, petechiae, photosensitivity.
