Meningitis

Question 1

Characteristics - Meningitis

Answer 1

Gram negative cocci, called Neisseria Meningitis. 13 groups based on immunological reactivity of capsular polysaccharides

Question 2

Adhesive virulence factors - Meningitis

Answer 2

Type IV pilli is major adhesin, mediates interaction with epithelial and endothelial cells as well as genetic transmormation and twitching motility. Opa promotes adherene to host cells and leukocytes and binds to CD66. Opc promotes adherence to host cells by binding to HSPG which is present on eukaryotic cells

Question 3

Invasion/Replication virulence factors - Meningitis

Answer 3

Opc and Opa stimulate engulfment of bacteria into phagocytic vacuoles. PorA and PorB creates pores in host cell membranes and cause skeleton rearrangement which allows for engulfment of bacteria.

Question 4

Evasion virulence factors - Meningitis

Answer 4

PorA down regulates FcY receptor and impedes ingestion by neutrophils. Polysaccharide capsule has anti-phagocytic and anti-bacteriocidal properties through steric hindrance, anti-adhesive and non immunogenic means allowing for survival in blood stream. Polysaccharide capsule serotypes with sialic acid derivates bind to complement factor H which discourages C3b to bacterial surfaces leading to inhibition of complement activation. IgA protease breaks IgA in hinge region and cleaves hLAMP1 to increase intracellular survival. LOS has similar role to LPS and contributes to serum resistance.

Question 5

Toxins - Meningitis

Answer 5

LOS can create a huge amount of inflammation leading to activation of clotting factor XII which results in tissue necrosis and bleeding

Question 6

Pathogenesis of Meningitis

Answer 6

Attachment, endocytosis, transport, release into sub-epithelial space

Question 7

How is Meningitis detected?

Answer 7

Spinal tap

Question 8

How is Meningitis treated?

Answer 8

Antibiotics