Why does Neisseria meningitidis cause petechiae?
The bacteria may seed local sites such as the meninges, joints or the pericardium or multiply in the bloodstream, causing meningococcemia with petechiae. Upto one third of patients present with meningitis without signs of sepsis.
What is the pathophysiology of bacterial meningitis?
Bacterial meningitis is characterized by the entry of bacteria into the cerebrospinal fluid (CSF) and bacterial growth in this compartment leading to inflammation within the CSF and the adjacent brain tissue.
How does Neisseria meningitidis cause disease?
The Neisseria meningitidis bacteria are spread through close contact with infected people. Droplets in the air from a sneeze or close conversation can be inhaled and may cause infection. In rare cases, the bacteria grow rapidly causing serious illness in both children and adults.
What is the pathogenesis of meningococcal meningitis?
Tissue damage in meningococcal disease is often caused by host immune mechanisms activated by endotoxin. Endotoxin binds to plasma endotoxin binding protein and to the cellular receptor, CD14 and other cellular receptors triggering an intense inflammatory response.
What characteristics of Neisseria meningitidis cause a rash?
The rash, a distinguishing feature, may initially appear as small lesions that may appear urticarial, macular, or papular. The rash can develop into petechiae, purpura, or ecchymosis later on. These may be early signs of thrombocytopenia, purpura fulminans, and DIC.
What is the pathophysiological mechanism behind the development of cerebral edema in infectious meningitis?
Three pathophysiologic mechanisms contribute to the development of cerebral oedema (the major cause of raised ICP) – vasogenic, cytotoxic and interstitial.
How does Neisseria meningitidis enter the blood?
meningitidis induces at the site of bacterial cell interaction the formation of a specific membrane domain enriched in structural proteins and membrane receptors designated the “cortical plaque.”83 This structure dramatically modifies the molecular equilibrium of the host cell, and leads to the opening of the blood- …
How does Neisseria meningitidis enter the meninges?
Meningeal invasion is a consequence of a tight interaction of meningococci with brain endothelial cells. This interaction, mediated by the type IV pili, is responsible for the formation of microcolonies on the apical surface of the cells.
Does Neisseria meningitidis cause bacteremia?
meningitidis is the pathogen that once in the bloodstream, is able to invade the meninges the most effectively. It has been estimated that 63% of the cases of bacteremia owing to N. meningitidis are associated with meningitis (InVS 2009).
Where is Neisseria meningitidis?
N. meningitidis bacteria are found in the nose and throat without causing disease.
How does neissera meningitidis affect the immune system?
It is now clear that Neissera meningitidis has evolved a number of surface structures to mediate interaction with host cells and a number of mechanisms to subvert the immune system and escape complement-mediated killing.
What kind of bacteria is the cause of meningococcal disease?
Bacteria called Neisseria meningitidis cause meningococcal disease. About 1 in 10 people have these bacteria in the back of their nose and throat without being ill. This is called being ‘a carrier’.
How does n.meningitidis colonize the body?
N. meningitidis colonizes mucosal surfaces using a multifactorial process involving pili, twitching motility, LOS, opacity associated, and other surface proteins. Certain clonal groups have an increased capacity to gain access to the blood, evade innate immune responses, multiply, and cause systemic disease.
Where are the highest rates of meningitis found?
Although meningococcal disease is found worldwide, the “meningitis belt” of sub-Saharan Africa has the highest rates in the world. Rates of meningococcal disease are several times higher in the meningitis belt than in the United States.