MICRO: Neisseria Meningitidis/Borrelia Flashcards
Pathogenic Neisseria
N. meningitidis
N. gonorrhea
Meningococcus Microbiology
Gram negative diplococcus
Aerobic
Oxidase positive
Meningococcus Identification
Virulence Factors of Meningococcus?
- Polysaccharide capsule: protects against host-mediated, complement-dependent bacteriolysis and phagocytosis
- Pili: promote adherence to epithelial and endothelial cells
- IgA1 protease: promote survival in epithelial cells
- Outer membrane proteins (Opa, Opc) – promotes adherence to host cells
- Lipooligosaccharide (LOS) – stimulate cytokine production and alternative complement pathway => intense inflammatory response
- Well developed iron acquisition system
Habitat of Meningococcus?
Pathogenesis of Meningococcus?
Spread by respiratory droplets or secretions
- enters nasopharynx and attaches to non ciliated epithelial cells by its pili
- attached organisms are engulfed by cells, enter phagocytic vacuoles and then pass through cells (passage through mucosa) - IgA1 protease promote survival in epithelial cells
- Enters bloodstream - intravascular survival promoted by capsule and iron acquisition
- In bloodstream, release blebs that contain LOS, OMP, and capsular polysaccharides=> stimulate cytokine production and alternative complement pathway
- Crosses BBB endothelium.
- Enters subarachnoid space.
Epidemiology of Meningococcus?
Most common infectious cause of death in children and young people up < 20 years old in Ireland?
Strains that most commonly impact different age groups?
Meningococcal Infection
In Ireland: Serogroup B accounts for 51.7% and serogroup C accounts for 22.5%.
Progression of Meningococcal Infection
Fulminant disease caused by meningococcal infection, characterized by multisystem involvement/failure, acute adrenal hemorrhage and high mortality
Waterhouse Friderichsen Syndrome
Outcome of Meningococcal Infection?
Borrelia Microbiology/Identification
__________________causes Lyme disease.
Borrelia burgdorferi causes Lyme disease. (Carried by Ixodes ticks)
________________ causes louse-borne relapsing fever (LBRF).
Borrelia recurrentis causes louse-borne relapsing fever (LBRF).
Lyme disease transmission
- Nymph primarily responsible for transmission.
- Humans are incidental host.
- During a blood meal, spirochaete transferred
to host from Ixodes tick’s saliva.
Characteristics of Stage 1 of Lyme Disease
Characteristics of Stage 2 of Lyme Disease
Characteristics of Stage 3 of Lyme Disease
Stage 3 (late disseminated disease)- Months to years post-infection.
Manifestations Include:
i. Musculoskeletal: arthralgia, intermittent arthritis, chronic arthritis
ii. Neurological: encephalopathy, peripheral neuropathy
iii. Skin: Acrodermatitis chronica atrophicans
Diagnosis of Lyme Disease
Treatment of Lyme Diseas
