GI infections Flashcards
Main bacterial pathogens that cause gastroenteritis
Salmonella Campylobacter C. perfringens V. Cholerae E. coli Shigella
Main viral pathogens that cause gastroenteritis
Rotavirus
Norovirus
Adenovirus
Main parasitic pathogens that cause gastroenteritis
Giardia
Entamoeba
Cryptosporidium
Host defences against pathogens
Secreted IgA
Peyer’s patches
Strategies for lab testing find a pathogen
- Attempt to grow the bacteria
- Look for specific toxins
- Look for parasites with a microscope
- Attempt to detect specific antigens
When are antigen/toxin tests done
For detecting a specific target and used routinely in the lab to test for viruses
When is microscopy done
to check for parasites
sample is concentrated first to improve sensitivity
How is viral gastroenteritis spread
Faeco-oral spred
symptoms of viral gastroenteritis
Explosive diarrhoea
How is viral gastroenteritis detected
Antigen testing or PCR
How to manage viral gastroenteritis
Supportive management e.g. rehydration
What does alcohol gel not kill
Clostridium difficile spores
What kind of spores do clostridium difficile form
Anaerobic spore former
How do antibiotics affect clostridium difficile
They kill other resident bacteria and let the C.diff multiply to high numbers
How can you diagnose. c.difficile
- sample sent from hospital patients with diarrhoea
- can check if colonised with c.diff by PCR
- ELISA used to see if producing toxins
