Please enable JavaScript.

Coggle requires JavaScript to display documents.

Campylobacter jejuni, Learning objectives - Coggle Diagram

- - - - Epithelial cells (TLR4 & 5)
      - Neutrophils
      - Macrophages
    - - Detect LOS & Flagellin
      - IL-8, TNF-α recruitment of neutrophils
      - Phagocytosis
        
        Reactive oxygen species, No killing
    - - Bacterial control
      - Inflammation
      - Diarrhoea
  - - - CD4+ Th1/Th17 T cells
    - - IFN-γ & IL-17 activate macrophage
      - Supports epithelial barrier repair
    - - Clearance of intracellular bacteria
  - - - B cells
      - IgA, IgG, IgM
    - - IgA blocks epithelial adhesion
      - IgG / IgM opsonisation
    - - Neutralisation
      - Systemic clearance
  - - - Commensal gut microbes
    - - Competitive exclusion
      - Restores homeostasis
    - - Prevents recolonisation
  - - - Regenerating epithelium
      - Regulatory T cells
    - - Inflammation subsides
      - Restored barrier
    - - Resolved systems
      - Eliminated bacteria
      - Short-lived immune memory
        
        Common reinfection
  - - - Starts in the legs then spreads quickly through the upper body
      - Loss of reflexes, senses, and possible respiratory failure
    - - Unique lipo-structures on the cell surface
        
        Lipid oligosaccharide
      - Mimics host gangliosides in human nerves
      - Infection
        
        Development of anti-LOS antibodies cross-react
- - - - Cross contamination
      - Direct animal contact
      - Uncooked meat
    - - Switches from viable to non-culturable (VBNC) state
        
        Cannot be cultured
      - Reduced metabolism
      - Conformational change into coccoid form
        
        Stress resistant
        
        Survival
    - - C. jejuni "resuscitates" once conditions improve (i.e. the gut)
  - - - Not part of the microbiome, so no mucosal tolerance
      - Not optimal conditions (37*C)
    - - Increased virulence factors
      - Adheres tightly to the intestinal epithelium using adhesins
        
        CadF
        
        Campylobacter adhesion to fibronectin
        
        Binds fibronectin in ECM
        
        Roles
        
        Triggers host signalling for infection
        
        Anchors bacteria
        
        JlpA
        
        Jejuni lipoprotein A
        
        Interacts with Hsp90
        
        Heat shock protein
        
        Role: Immune activation
        
        PEB proteins
        
        Periplasmic binding proteins
        
        Roles
        
        Nutrient uptake
        
        Surface binding
        
        Prevents washing away by intestinal peristalsis
  - - - Actively searches for a suitable spot
      - Bipolar flagella
        
        Acts as secretion systems for virulence proteins
      - Corkscrew motion
        
        Helps penetrate viscous mucus in intestinal tract
    - - Chemoreceptors
        
        Detects gradients of
        
        Amino acids
        
        Sugars
        
        Mucin components
        
        Active movement towards nutrient-rich mucus and find ideal colonisation niches near epithelial cells
      - Chemotaxis
        
        Increased virulence
  - - - Deliver proteins
      - Triggers actin cytoskeleton rearrangements
        
        Bacterial internalisation
        
        Hide from the immune system
      - Disrupts tight junctions
        
        Weakens epithelial barrier
    - - Causes DNA double-strand breaks
        
        Cell cycle arrest
      - Symptoms
        
        Apoptosis
        
        Barrier dysfunction
        
        Inflammation
        
        Epithelial damage
- - - - Natural host
      - Asymptomatic colonisation
        
        In the cecum
      - Mild immune response / no disease
    - - Found in faeces
      - Problem in younger animals
      - Asymptomatic / subclinical
  - - - Undercooked poultry