MICROBIOLOGY OF THE GUT Flashcards
outline the cycle of malnutrition and GI infections?
GI infections exacerbate malnutrition and malnutrition lowers resistance to GI infection
what is gastroenteritis?
infectious diarrhoea and vomiting due to inflammation of the GI tract, particularly the stomach and small intestine.
what are symptoms of gastroenteritis?
diarrhoea, vomiting and abdominal pain. Fever, lack of energy and dehydration can also occur.
how long do gastroenteritis symptoms typically last?
<2 weeks
what are some examples of causative organisms of gastroenteritis?
rotavirus, norovirus, adenovirus, E.coli, campylobacter jejune, salmonella, shigella, entamoeba histolytica
outline the pathophysiology of gastroenteritis?
Pathogen invades the epithelium in the gastrointestinal wall and causes these cells to die. Now the epithelial cells cant digest and absorb food and water and so it cant enter your system = vomiiting, diarrhoea and dehydration.
why can you not cohort patients with gastroenteritis?
as you dont know the causative organism so patients might get other patient’s infections
what should you ask a patient to try to find the cause of gastroeneteritis?
travel history contact history social events food pets
what type of diet can help reduce symptoms of gastroenteritis?
low dairy, low fat and high fibre diet
what diagnostic tests can be done for gastroeneteritis?
stool sample and blood tests
whats the treatment for gastroeneteritis?
oral rehydration therapy
antibiotics sometimes
how can you avoid gastroeneteritis?
good hygiene
cook food really well
drink clean water
why are antibiotics not always given in gastroenteritis?
the illness is usually self limiting, can damage the flora of GI tract and can make E.coli 0157 worse
what are some host defences against GI infection?
behavioural e.g. put off by sewage smells
gastric ph low
bile acids and salts can emulsify cell membranes of bacteria
peristalsis
mucus - physical and lysozymes
immunity - secretory IgA
regional flora of GI tract
outline the pattern of regional GI flora?
small nubers at the stomach and small intestine with nubers increasing as you head towards the colon
anaerobes also increase as you move towards the colon
whats the function of the appendix?
a MALT and stores normal flora from the bowel so can replenish it