Extracellular immunity 1 Flashcards
Name some prokaryotic extracellular pathogens and the disease that they cause
e.coli- diahreea
steptoccosus pyogenes - rheumatic fever , scarlet fever
clostidum tetani - tetanus
staphylococcus aureus -mrsa
helicobacter pylori - gastric ulcers
Examples of parasitic infections caused by extracellular pathogens
Protozoa -sleeping sickness
parasitic worms - schistomiasis
example of a fungal extracellular pathogen and a disease it causes
candida albicans - thrush
What are the consequences of host microbe interactions
Secondary infections due to toxins
cell and tissue destruction
morbidity ,disability and mortality
measured using qalys and dalys
How can the host respond to extracellular pathogens
Achieve eqm with microbiome
eliminate the pathogen
WHat are the host defences agianst extracellular pathogens
Antibiotics and immune responses in ICU patients
soluble mediators
complement system
Phagocytosis
What are the roles of th2 and th17 responses in immunity to extracellular pathogens
Th2 responses - lead to class switiching to iga ,igg and ige
Th17-response - crucial for antifungal and antibacterial immunity
what are the functions of antibodies in extracellular immunity ?
Neutralisation of bacterial toxins
Ige activates basophils and mast cells
Eosinophils activation
How does group a steptococcus pyogenes evade the immune system
capsule prevents phagocytosis
m protein inactivates c3b
exotoxins cause tissue destruction
What diseases are caused by steptococcus pyogenes
Rheumatic fever
Glomerulonephritis
Toxic shock syndrome
What are the characterisitics of e coli strains
Produce shiga like toxins
uropathogenic strains
lps - can cause endotoxin shock
how does h pylori survive in the stomach
produces catalyse ,urease and superoxide dismutase
cagPAI
CagA protein
What type of immunity is essential against fungal infections?
Th17 mediated immunity and neutrophil response
How are fungal pathogens recognised by the immune system
Lectins - recognise fungal cell wall components
dectin-1 major prr that directs immune response towards th17
What immune defects increase suscepitbilty to fungal infections
CGD patients
Neutropenic patients
Aids patients
What are the main immune mechanism against extracellular pathogen?
soluble mediators,antibodies,cellular responses
